WorldWideScience

Sample records for high arousal led

  1. Multicolor, High Efficiency, Nanotextured LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Jung Han; Arto Nurmikko

    2011-09-30

    We report on research results in this project which synergize advanced material science approaches with fundamental optical physics concepts pertaining to light-matter interaction, with the goal of solving seminal problems for the development of very high performance light emitting diodes (LEDs) in the blue and green for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) heteroepitaxy of nitrogen-polar LEDs on sapphire, (ii) heteroepitaxy of semipolar (11{bar 2}2) green LEDs on sapphire, (iii) synthesis of quantum-dot loaded nanoporous GaN that emits white light without phosphor conversion, (iv) demonstration of the highest quality semipolar (11{bar 2}2) GaN on sapphire using orientation-controlled epitaxy, (v) synthesis of nanoscale GaN and InGaN medium, and (vi) development of a novel liftoff process for manufacturing GaN thin-film vertical LEDs. The body of results is presented in this report shows how a solid foundation has been laid, with several noticeable accomplishments, for innovative research, consistent with the stated milestones.

  2. Response inhibition and immediate arousal in children with high-functioning autism

    NARCIS (Netherlands)

    Raymaekers, Ruth; van der Meere, Jaap; Roeyers, Herbert

    2006-01-01

    The current study compared high-functioning children with autism (HFA) and a peer control group on an immediate arousal task measuring response inhibition. In one condition go stimuli were presented whereas in another condition a tone preceded the go stimulus. The tone caused an immediate arousal ef

  3. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

    Karlicek, Robert, F., Jr; Sargent, Robert

    2012-05-14

    UV curing is a green technology that is largely underutilized because UV radiation sources like Hg Lamps are unreliable and difficult to use. High Power UV LEDs are now efficient enough to replace Hg Lamps, and offer significantly improved performance relative to Hg Lamps. In this study, a modular, scalable high power UV LED curing system was designed and tested, performing well in industrial coating evaluations. In order to achieve mechanical form factors similar to commercial Hg Lamp systems, a new patent pending design was employed enabling high irradiance at long working distances. While high power UV LEDs are currently only available at longer UVA wavelengths, rapid progress on UVC LEDs and the development of new formulations designed specifically for use with UV LED sources will converge to drive more rapid adoption of UV curing technology. An assessment of the environmental impact of replacing Hg Lamp systems with UV LED systems was performed. Since UV curing is used in only a small portion of the industrial printing, painting and coating markets, the ease of use of UV LED systems should increase the use of UV curing technology. Even a small penetration of the significant number of industrial applications still using oven curing and drying will lead to significant reductions in energy consumption and reductions in the emission of green house gases and solvent emissions.

  4. High-power LED package requirements

    Science.gov (United States)

    Wall, Frank; Martin, Paul S.; Harbers, Gerard

    2004-01-01

    Power LEDs have evolved from simple indicators into illumination devices. For general lighting applications, where the objective is to light up an area, white LED arrays have been utilized to serve that function. Cost constraints will soon drive the industry to provide a discrete lighting solution. Early on, that will mean increasing the power densities while quantum efficiencies are addressed. For applications such as automotive headlamps & projection, where light needs to be tightly collimated, or controlled, arrays of die or LEDs will not be able to satisfy the requirements & limitations defined by etendue. Ultimately, whether a luminaire requires a small source with high luminance, or light spread over a general area, economics will force the evolution of the illumination LED into a compact discrete high power package. How the customer interfaces with this new package should be an important element considered early on in the design cycle. If an LED footprint of adequate size is not provided, it may prove impossible for the customer, or end user, to get rid of the heat in a manner sufficient to prevent premature LED light output degradation. Therefore it is critical, for maintaining expected LED lifetime & light output, that thermal performance parameters be defined, by design, at the system level, which includes heat sinking methods & interface materials or methdology.

  5. White LED with High Package Extraction Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Yi Zheng; Matthew Stough

    2008-09-30

    The goal of this project is to develop a high efficiency phosphor converting (white) Light Emitting Diode (pcLED) 1-Watt package through an increase in package extraction efficiency. A transparent/translucent monolithic phosphor is proposed to replace the powdered phosphor to reduce the scattering caused by phosphor particles. Additionally, a multi-layer thin film selectively reflecting filter is proposed between blue LED die and phosphor layer to recover inward yellow emission. At the end of the project we expect to recycle approximately 50% of the unrecovered backward light in current package construction, and develop a pcLED device with 80 lm/W{sub e} using our technology improvements and commercially available chip/package source. The success of the project will benefit luminous efficacy of white LEDs by increasing package extraction efficiency. In most phosphor-converting white LEDs, the white color is obtained by combining a blue LED die (or chip) with a powdered phosphor layer. The phosphor partially absorbs the blue light from the LED die and converts it into a broad green-yellow emission. The mixture of the transmitted blue light and green-yellow light emerging gives white light. There are two major drawbacks for current pcLEDs in terms of package extraction efficiency. The first is light scattering caused by phosphor particles. When the blue photons from the chip strike the phosphor particles, some blue light will be scattered by phosphor particles. Converted yellow emission photons are also scattered. A portion of scattered light is in the backward direction toward the die. The amount of this backward light varies and depends in part on the particle size of phosphors. The other drawback is that yellow emission from phosphor powders is isotropic. Although some backward light can be recovered by the reflector in current LED packages, there is still a portion of backward light that will be absorbed inside the package and further converted to heat. Heat

  6. High-power LEDs for plant cultivation

    Science.gov (United States)

    Tamulaitis, Gintautas; Duchovskis, Pavelas; Bliznikas, Zenius; Breive, Kestutis; Ulinskaite, Raimonda; Brazaityte, Ausra; Novickovas, Algirdas; Zukauskas, Arturas; Shur, Michael S.

    2004-10-01

    We report on high-power solid-state lighting facility for cultivation of greenhouse vegetables and on the results of the study of control of photosynthetic activity and growth morphology of radish and lettuce imposed by variation of the spectral composition of illumination. Experimental lighting modules (useful area of 0.22 m2) were designed based on 4 types of high-power light-emitting diodes (LEDs) with emission peaked in red at the wavelengths of 660 nm and 640 nm (predominantly absorbed by chlorophyll a and b for photosynthesis, respectively), in blue at 455 nm (phototropic function), and in far-red at 735 nm (important for photomorphology). Morphological characteristics, chlorophyll and phytohormone concentrations in radish and lettuce grown in phytotron chambers under lighting with different spectral composition of the LED-based illuminator and under illumination by high pressure sodium lamps with an equivalent photosynthetic photon flux density were compared. A well-balanced solid-state lighting was found to enhance production of green mass and to ensure healthy morphogenesis of plants compared to those grown using conventional lighting. We observed that the plant morphology and concentrations of morphologically active phytohormones is strongly affected by the spectral composition of light in the red region. Commercial application of the LED-based illumination for large-scale plant cultivation is discussed. This technology is favorable from the point of view of energy consumption, controllable growth, and food safety but is hindered by high cost of the LEDs. Large scale manufacturing of high-power red AlInGaP-based LEDs emitting at 650 nm and a further decrease of the photon price for the LEDs emitting in the vicinity of the absorption peak of chlorophylls have to be achieved to promote horticulture applications.

  7. Sex Differences in Emotional Evaluation of Film Clips: Interaction with Five High Arousal Emotional Categories

    Science.gov (United States)

    Maffei, Antonio; Vencato, Valentina; Angrilli, Alessandro

    2015-01-01

    The present study aimed to investigate gender differences in the emotional evaluation of 18 film clips divided into six categories: Erotic, Scenery, Neutral, Sadness, Compassion, and Fear. 41 female and 40 male students rated all clips for valence-pleasantness, arousal, level of elicited distress, anxiety, jittery feelings, excitation, and embarrassment. Analysis of positive films revealed higher levels of arousal, pleasantness, and excitation to the Scenery clips in both genders, but lower pleasantness and greater embarrassment in women compared to men to Erotic clips. Concerning unpleasant stimuli, unlike men, women reported more unpleasantness to the Compassion, Sadness, and Fear compared to the Neutral clips and rated them also as more arousing than did men. They further differentiated the films by perceiving greater arousal to Fear than to Compassion clips. Women rated the Sadness and Fear clips with greater Distress and Jittery feelings than men did. Correlation analysis between arousal and the other emotional scales revealed that, although men looked less aroused than women to all unpleasant clips, they also showed a larger variance in their emotional responses as indicated by the high number of correlations and their relatively greater extent, an outcome pointing to a masked larger sensitivity of part of male sample to emotional clips. We propose a new perspective in which gender difference in emotional responses can be better evidenced by means of film clips selected and clustered in more homogeneous categories, controlled for arousal levels, as well as evaluated through a number of emotion focused adjectives. PMID:26717488

  8. High Performance Green LEDs by Homoepitaxial

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian; Schubert, E Fred

    2009-11-22

    This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.

  9. High Performance Green LEDs by Homoepitaxial

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian; Schubert, E Fred

    2009-11-22

    This work's objective was the development of processes to double or triple the light output power from green and deep green (525 - 555 nm) AlGaInN light emitting diode (LED) dies within 3 years in reference to the Lumileds Luxeon II. The project paid particular effort to all aspects of the internal generation efficiency of light. LEDs in this spectral region show the highest potential for significant performance boosts and enable the realization of phosphor-free white LEDs comprised by red-green-blue LED modules. Such modules will perform at and outperform the efficacy target projections for white-light LED systems in the Department of Energy's accelerated roadmap of the SSL initiative.

  10. Stress selectively and lastingly promotes learning of context-related high arousing information.

    Science.gov (United States)

    Smeets, Tom; Wolf, Oliver T; Giesbrecht, Timo; Sijstermans, Kevin; Telgen, Sebastian; Joëls, Marian

    2009-09-01

    The secretion of adrenal stress hormones in response to acute stress is known to affect learning and memory, particularly for emotionally arousing memory material. Here, we investigated whether stress-induced modulation of learning and memory performance depends on (i) the conceptual relatedness between the material to be learned/remembered and the stressor and (ii) the timing of stress exposure versus learning phase. Participants learned stressor-related and stressor-unrelated words of varying arousal 1h prior to, immediately following, or 2h after exposure to the Trier Social Stress Test (all groups n=16). Twenty-four hours later, delayed free recall was assessed. Cortisol and alpha-amylase were sampled to evaluate if concurrent stress-induced raised glucocorticoid levels and high adrenergic activity are implicated in modulating learning performance. Our results demonstrate that immediate and delayed post-stress learning selectively enhanced the learning and delayed recall of stressor-related high arousing words. This enhancing effect was strongly associated with concurrent stress-induced cortisol and sympathetic activity. Our data suggest that when to-be-learned information is conceptually related to a stressor and considered important (i.e., arousing) by the individual, learning under stressful circumstances results in improved memorability afterwards.

  11. Encoding negative events under stress: high subjective arousal is related to accurate emotional memory despite misinformation exposure.

    Science.gov (United States)

    Hoscheidt, Siobhan M; LaBar, Kevin S; Ryan, Lee; Jacobs, W Jake; Nadel, Lynn

    2014-07-01

    Stress at encoding affects memory processes, typically enhancing, or preserving, memory for emotional information. These effects have interesting implications for eyewitness accounts, which in real-world contexts typically involve encoding an aversive event under stressful conditions followed by potential exposure to misinformation. The present study investigated memory for a negative event encoded under stress and subsequent misinformation endorsement. Healthy young adults participated in a between-groups design with three experimental sessions conducted 48 h apart. Session one consisted of a psychosocial stress induction (or control task) followed by incidental encoding of a negative slideshow. During session two, participants were asked questions about the slideshow, during which a random subgroup was exposed to misinformation. Memory for the slideshow was tested during the third session. Assessment of memory accuracy across stress and no-stress groups revealed that stress induced just prior to encoding led to significantly better memory for the slideshow overall. The classic misinformation effect was also observed - participants exposed to misinformation were significantly more likely to endorse false information during memory testing. In the stress group, however, memory accuracy and misinformation effects were moderated by arousal experienced during encoding of the negative event. Misinformed-stress group participants who reported that the negative slideshow elicited high arousal during encoding were less likely to endorse misinformation for the most aversive phase of the story. Furthermore, these individuals showed better memory for components of the aversive slideshow phase that had been directly misinformed. Results from the current study provide evidence that stress and high subjective arousal elicited by a negative event act concomitantly during encoding to enhance emotional memory such that the most aversive aspects of the event are well remembered and

  12. LED module with high index lens

    Energy Technology Data Exchange (ETDEWEB)

    Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.; Sun, Decai; Wei, Yajun

    2017-09-05

    An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.

  13. LED module with high index lens

    Energy Technology Data Exchange (ETDEWEB)

    Bierhuizen, Serge J.; Wang, Nanze Patrick; Eng, Gregory W.; Sun, Decai; Wei, Yajun

    2016-07-05

    An array of housings with housing bodies and lenses is molded, or an array of housing bodies is molded and bonded with lenses to form an array of housings with housing bodies and lenses. Light-emitting diodes (LEDs) are attached to the housings in the array. An array of metal pads may be bonded to the back of the array or insert molded with the housing array to form bond pads on the back of the housings. The array is singulated to form individual LED modules.

  14. High brightness near-ultraviolet resonant LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, B.; Roycroft, B.; Maaskant, P.; Akhter, M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Zhu, D.; McAleese, C.; Kappers, M.J.; Humphreys, C.J. [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB2 3QZ (United Kingdom)

    2008-07-01

    Planar near-ultraviolet 385 nm emitting resonant LEDs containing three quantum wells have been investigated as a function of the separation between the wells and a reflective and injecting metal mirror. The output power and far-field extracted through the substrate of the LEDs depend on the precise positions of the wells with each well having a significant individual influence on these properties. A doubling of the output power is obtained when the wells are located around the antinode position of the standing wave while narrower far-fields are obtained with other placement of the wells. A power of 0.4 mW into a numerical aperture of 0.5 is obtained for a current of 30 mA into a 50 {mu}m diameter contact. Calibration of the growth rate along with accurate knowledge of the material properties of the semiconductor and metal mirrors is required for controlled and enhanced emission from planar UV LEDs. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Thermal design for the high-power LED lamp

    Energy Technology Data Exchange (ETDEWEB)

    Tian Xiaogai; Chen Wei; Zhang Jiyong, E-mail: tianxiaogai@sina.com [NVC Lighting Technology Corporation Research and Development Center (Shanghai), Shanghai 201112 (China)

    2011-01-15

    This paper summarizes different kinds of heat sinks on the market for high power LED lamps. Analysis is made on the thermal model of LED, PCB and heat sink separately with a simplified mode provided. Two examples of simulation are illustrated as a demonstration for the thermal simulation as guidance for LED lamp design. (semiconductor devices)

  16. Variability in emotional/behavioral problems in boys with oppositional defiant disorder or conduct disorder : the role of arousal

    NARCIS (Netherlands)

    Schoorl, Jantiene; Van Rijn, Sophie; De Wied, Minet; Van Goozen, Stephanie H M; Swaab, Hanna

    2016-01-01

    It is often reported that children with oppositional defiant disorder (ODD) or conduct disorder (CD) are under-aroused. However, the evidence is mixed, with some children with ODD/CD displaying high arousal. This has led to the hypothesis that different profiles of arousal dysfunction may exist

  17. High Efficiency Driving Electronics for General Illumination LED Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Anand

    2012-10-31

    New generation of standalone LED driver platforms developed, which are more efficient These LED Drivers are more efficient (≥90%), smaller in size ( 0.15 in3/watt), lower in cost ( 12 cents/watt in high volumes in millions of units). And these products are very reliable having an operating life of over 50,000 hours. This technology will enable growth of LED light sources in the use. This will also help in energy saving and reducing total life cycle cost of LED units. Two topologies selected for next generation of LED drivers: 1) Value engineered single stage Flyback topology. This is suitable for low powered LED drivers up to 50W power. 2) Two stage boost power factor correction (PFC) plus LLC half bridge platform for higher powers. This topology is suitable for 40W to 300W LED drivers. Three new product platforms were developed to cover a wide range of LED drivers: 1) 120V 40W LED driver, 2) Intellivolt 75W LED driver, & 3) Intellivolt 150W LED driver. These are standalone LED drivers for rugged outdoor lighting applications. Based on these platforms number of products are developed and successfully introduced in the market place meeting key performance, size and cost goals.

  18. High performance LED lamps for the automobile: needs and opportunities

    Science.gov (United States)

    Pohlmann, Wolfgang; Vieregge, Thomas; Rode, Martin

    2007-09-01

    Light emitting diodes have been an option in automotive lighting for more than 15 years now. The capacities and colours of LEDs available in the recent past were sufficient to realize interior lighting and rear signalling functions. In the meantime, series applications, such as position or daytime running lights, using white LEDs for signal functions in headlamps, are no longer a rarity. The next step - realizing main lighting functions for series applications - is imminent. LED will offer a multitude of styling options in rear and front lighting, as well as a light colour which differs considerably from that of the previous halogen and xenon headlamp systems. The further advantages of the LED compared with conventional light sources with regard to service life, power efficiency and package space requirements can thus only be sensibly exploited by means of suitable structural and connection techniques. Increasing complexity and installation conditions in an often rough environment are demanding challenge to realize the hardware of LED lamps. In this paper at first the requirements on LEDs and LED modules in automotive exterior lighting will be discussed. Furthermore the status of industrialization and modular concepts for signal lamps and full LED headlamps will be presented. The paper will finish with a discussion of new headlamp active lighting functions like maker light or glare free high beam, implemented in hybrid or with pure LED technology. In the subsequent headlamp integration, from about 2012, freely-addressable LED-Arrays will possibly enable these new types of lighting functions.

  19. Development of high-performance solar LED lighting system

    KAUST Repository

    Huang, B.J.

    2010-08-01

    The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

  20. Single phase forced convection cooling of high power leds

    NARCIS (Netherlands)

    Ozdemir, M.Z.; Chestakov, D.; Frijns, A.J.H.

    2011-01-01

    LEDs are strong candidates for future illumination applications dueto their much lower consumption of energy compared to conventional lighting options. One of key problems in development of LEDs is successful thermal management during illumination. Therefore, current research ongoing related to high

  1. Low Cost Lithography Tool for High Brightness LED Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Hawryluk; Emily True

    2012-06-30

    The objective of this activity was to address the need for improved manufacturing tools for LEDs. Improvements include lower cost (both capital equipment cost reductions and cost-ofownership reductions), better automation and better yields. To meet the DOE objective of $1- 2/kilolumen, it will be necessary to develop these highly automated manufacturing tools. Lithography is used extensively in the fabrication of high-brightness LEDs, but the tools used to date are not scalable to high-volume manufacturing. This activity addressed the LED lithography process. During R&D and low volume manufacturing, most LED companies use contact-printers. However, several industries have shown that these printers are incompatible with high volume manufacturing and the LED industry needs to evolve to projection steppers. The need for projection lithography tools for LED manufacturing is identified in the Solid State Lighting Manufacturing Roadmap Draft, June 2009. The Roadmap states that Projection tools are needed by 2011. This work will modify a stepper, originally designed for semiconductor manufacturing, for use in LED manufacturing. This work addresses improvements to yield, material handling, automation and throughput for LED manufacturing while reducing the capital equipment cost.

  2. High Output LED-Based Profile Lighting Fixture

    DEFF Research Database (Denmark)

    Török, Lajos; Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    Recent developments in power light emitting diode (LED) industry have made LEDs suitable for being efficiently used in high intensity lighting fixtures instead of the commonly used high intensity discharge (HID) lamps. A high output LEDbased profile-light fixture is presented in this paper....... The system consists of a power supply with power factor correction (PFC), a LED-driver and an optical system designed for an overall high efficiency. An interleaved boost converter was chosen as PFC converter. A soft switching phase-shifted full-bridge converter with current doubler provides isolation from...... the grid and delivers the required voltage to the LEDdriver which is a dual interleaved buck converter. Twelve highpower CBT-90 LEDs have been connected in a 4xRGBconfiguration to deliver high output of saturated colors without the need for subtractive color filters. More than 6000 lm of fixture light...

  3. Prognostics and Health Monitoring of High Power LED

    Directory of Open Access Journals (Sweden)

    Chris Bailey

    2012-02-01

    Full Text Available Prognostics is seen as a key component of health usage monitoring systems, where prognostics algorithms can both detect anomalies in the behavior/performance of a micro-device/system, and predict its remaining useful life when subjected to monitored operational and environmental conditions. Light Emitting Diodes (LEDs are optoelectronic micro-devices that are now replacing traditional incandescent and fluorescent lighting, as they have many advantages including higher reliability, greater energy efficiency, long life time and faster switching speed. For some LED applications there is a requirement to monitor the health of LED lighting systems and predict when failure is likely to occur. This is very important in the case of safety critical and emergency applications. This paper provides both experimental and theoretical results that demonstrate the use of prognostics and health monitoring techniques for high power LEDs subjected to harsh operating conditions.

  4. Event-rate manipulation and its effect on arousal modulation and response inhibition in adults with high functioning autism

    NARCIS (Netherlands)

    Raymaekers, R; van der Meere, J; Roeyers, H

    2004-01-01

    The aim of the current study was to evaluate arousal modulation and response inhibition in adults with high functioning autism (HFA). Using a go/no-go paradigm with varying presentation rate, it was found that performance efficiency (Mean RT, Standard Deviation of RT and Errors of Commission) in adu

  5. Current State of the Art in High Brightness LEDs

    Science.gov (United States)

    Craford, George

    2007-03-01

    LED's have been commercially available since the 1960's. For many years they were used primarily for indicator applications. The remarkable increase in materials technology and efficiency that has been achieved since the early 1990's for AlInGaP red and amber LEDs, and InGaN green and blue LEDs, has enabled the penetration of markets such as outdoor display, signaling, and automotive brake light and turn signal applications. White LEDs, which are either blue LEDs combined with a phosphor, or a combination of red, green, and blue LEDs, are being used in emerging applications such as cell phone flash, television backlights, projection, and automotive headlights. In addition, to efficiency improvements these applications have required the development of higher power packages and, in some of these applications which are etendue limited, higher luminance devices. High power devices are commercially available which are capable of 140 lumens output and have an efficacy of around 70 lm/W for white emission. New package and chip technologies have been demonstrated which have a luminance of 38 mega nits (Mcd/m^2), approximately 50% more luminance than that of an automotive headlamp halogen bulb (˜25 mega nits). The recent progress in materials technology, packaging, and chip technology makes it clear that LED's will become important for general illumination applications. The rate of LED penetration of this market will depend upon continued increases in performance and lower costs as well as better control of the white spectral emission. Efficiency, current density, and costs are closely linked because the cost in dollars/lumen is inversely proportional to how many lumens can be realized from each unit of device area for a given device type. Performance as high as 138 lm/W, and over 40% wall plug efficiency, has been reported for low power research devices and over 90 lm/W for high power research devices. It is clear that high power commercial products with performance in

  6. High Output LED-Based Profile Lighting Fixture

    DEFF Research Database (Denmark)

    Török, Lajos; Beczkowski, Szymon; Munk-Nielsen, Stig;

    2011-01-01

    . The system consists of a power supply with power factor correction (PFC), a LED-driver and an optical system designed for an overall high efficiency. An interleaved boost converter was chosen as PFC converter. A soft switching phase-shifted full-bridge converter with current doubler provides isolation from...... the grid and delivers the required voltage to the LEDdriver which is a dual interleaved buck converter. Twelve highpower CBT-90 LEDs have been connected in a 4xRGBconfiguration to deliver high output of saturated colors without the need for subtractive color filters. More than 6000 lm of fixture light...

  7. A thermosyphon heat pipe cooler for high power LEDs cooling

    Science.gov (United States)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  8. Highly Efficient Small Form Factor LED Retrofit Lamp

    Energy Technology Data Exchange (ETDEWEB)

    Steven Allen; Fred Palmer; Ming Li

    2011-09-11

    This report summarizes work to develop a high efficiency LED-based MR16 lamp downlight at OSRAM SYLVANIA under US Department of Energy contract DE-EE0000611. A new multichip LED package, electronic driver, and reflector optic were developed for these lamps. At steady-state, the lamp luminous flux was 409 lumens (lm), luminous efficacy of 87 lumens per watt (LPW), CRI (Ra) of 87, and R9 of 85 at a correlated color temperature (CCT) of 3285K. The LED alone achieved 120 lumens per watt efficacy and 600 lumen flux output at 25 C. The driver had 90% electrical conversion efficiency while maintaining excellent power quality with power factor >0.90 at a power of only 5 watts. Compared to similar existing MR16 lamps using LED sources, these lamps had much higher efficacy and color quality. The objective of this work was to demonstrate a LED-based MR16 retrofit lamp for replacement of 35W halogen MR16 lamps having (1) luminous flux of 500 lumens, (2) luminous efficacy of 100 lumens per watt, (3) beam angle less than 40{sup o} and center beam candlepower of at least 1000 candelas, and (4) excellent color quality.

  9. High-Voltage LED Light Engine with Integrated Driver

    Energy Technology Data Exchange (ETDEWEB)

    Soer, Wouter [Lumileds LLC, San Jose, CA (United States)

    2016-02-29

    LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm2), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm2 and 4 mm2) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux

  10. High-Voltage LED Light Engine with Integrated Driver

    Energy Technology Data Exchange (ETDEWEB)

    Soer, Wouter [Lumileds LLC, San Jose, CA (United States)

    2016-02-29

    LED luminaires have seen dramatic changes in cost breakdown over the past few years. The LED component cost, which until recently was the dominant portion of luminaire cost, has fallen to a level of the same order as the other luminaire components, such as the driver, housing, optics etc. With the current state of the technology, further luminaire performance improvement and cost reduction is realized most effectively by optimization of the whole system, rather than a single component. This project focuses on improving the integration between LEDs and drivers. Lumileds has developed a light engine platform based on low-cost high-power LEDs and driver topologies optimized for integration with these LEDs on a single substrate. The integration of driver and LEDs enables an estimated luminaire cost reduction of about 25% for targeted applications, mostly due to significant reductions in driver and housing cost. The high-power LEDs are based on Lumileds’ patterned sapphire substrate flip-chip (PSS-FC) technology, affording reduced die fabrication and packaging cost compared to existing technology. Two general versions of PSS-FC die were developed in order to create the desired voltage and flux increments for driver integration: (i) small single-junction die (0.5 mm2), optimal for distributed lighting applications, and (ii) larger multi-junction die (2 mm2 and 4 mm2) for high-power directional applications. Two driver topologies were developed: a tapped linear driver topology and a single-stage switch-mode topology, taking advantage of the flexible voltage configurations of the new PSS-FC die and the simplification opportunities enabled by integration of LEDs and driver on the same board. A prototype light engine was developed for an outdoor “core module” application based on the multi-junction PSS-FC die and the single-stage switch-mode driver. The light engine meets the project efficacy target of 128 lm/W at a luminous flux greater than 4100 lm, a correlated

  11. LED-Based High-Voltage Lines Warning System

    Directory of Open Access Journals (Sweden)

    Eldar MUSA

    2013-04-01

    Full Text Available LED-based system, running with the current of high-voltage lines and converting the current flowing through the line into the light by using a toroid transformer, has been developed. The transformer’s primary winding is constituted by the high voltage power line. Toroidal core consists of two equal parts and the secondary windings are evenly placed on these two parts. The system is mounted on the high-voltage lines as a clamp. The secondary winding ends are connected in series by the connector on the clamp. LEDs are supplied by the voltage at the ends of secondary. Current flowing through highvoltage transmission lines is converted to voltage by the toroidal transformer and the light emitting LEDs are supplied with this voltage. The theory of the conversion of the current flowing through the line into the light is given. The system, running with the current of the line and converting the current into the light, has been developed. System has many application areas such as warning high voltage lines (warning winches to not hinder the high-voltage lines when working under the lines, warning planes to not touch the high-voltage lines, remote measurement of high-voltage line currents, and local illumination of the line area

  12. Stress selectively and lastingly promotes learning of context-related high arousing information

    NARCIS (Netherlands)

    Smeets, T.; Wolf, O.T.; Giesbrecht, T.; Sijstermans, K.; Telgen, S.; Joëls, M.

    2009-01-01

    The secretion of adrenal stress hormones in response to acute stress is known to affect learning and memory, particularly for emotionally arousing memory material. Here, we investigated whether stress-induced modulation of learning and memory performance depends on (i) the conceptual relatedness bet

  13. Digital controlling system to the set of high power LEDs

    Science.gov (United States)

    Gilewski, Marian; Gryko, Lukasz; Zajac, Andrzej

    2013-07-01

    In the paper is described the concept and architecture of the multi-channel control system for set of high-power LEDs. The broadband source of radiation for prototype illuminator is dedicated to the investigation of Low Level Laser Therapy procedures. The general scheme of the system, detailed schemes, control algorithm and its implementation description in FPGA structure is presented. The temperature conditions and the opportunity to work with a microcomputer are characterized.

  14. Design method for automotive high-beam LED optics

    Science.gov (United States)

    Byzov, Egor V.; Moiseev, Mikhail A.; Doskolovich, Leonid L.; Kazanskiy, Nikolay L.

    2015-09-01

    New analytical method for the calculation of the LED secondary optics for automotive high-beam lamps is presented. Automotive headlamps should illuminate the road and the curb at the distance of 100-150 meters and create a bright, flat, relatively powerful light beam. To generate intensity distribution of this kind we propose to use TIR optical element (collimator working on the total internal reflection principle) with array of microlenses (optical corrector) on the upper surface. TIR part of the optical element enables reflection of the side rays to the front direction and provides a collimated beam which incidents on the microrelief. Microrelief, in its turn, dissipates the light flux in horizontal direction to meet the requirements of the Regulations 112, 113 and to provide well-illuminated area across the road in the far field. As an example, we computed and simulated the optical element with the diameter of 33 millimeters and the height of 22 millimeters. Simulation data shows that three illuminating modules including Cree XP-G2 LED and lens allow generating an appropriate intensity distribution for the class D of UNECE Regulations.

  15. Two phase interleaved buck converter for driving high power LEDs

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...

  16. Reliability test and failure analysis of high power LED packages*

    Institute of Scientific and Technical Information of China (English)

    Chen Zhaohui; Zhang Qin; Wang Kai; Luo Xiaobing; Liu Sheng

    2011-01-01

    A new type application specific light emitting diode (LED) package (ASLP) with freeform polycarbonate lens for street lighting is developed, whose manufacturing processes are compatible with a typical LED packaging process. The reliability test methods and failure criterions from different vendors are reviewed and compared. It is found that test methods and failure criterions are quite different. The rapid reliability assessment standards are urgently needed for the LED industry. 85 ℃/85 RH with 700 mA is used to test our LED modules with three other vendors for 1000 h, showing no visible degradation in optical performance for our modules, with two other vendors showing significant degradation. Some failure analysis methods such as C-SAM, Nano X-ray CT and optical microscope are used for LED packages. Some failure mechanisms such as delaminations and cracks are detected in the LED packages after the accelerated reliability testing. The finite element simulation method is helpful for the failure analysis and design of the reliability of the LED packaging. One example is used to show one currently used module in industry is vulnerable and may not easily pass the harsh thermal cycle testing.

  17. Heat Transfer Characteristics in High Power LED Packaging

    OpenAIRE

    Chi-Hung Chung; Kai-Shing Yang; Kuo-Hsiang Chien; Ming-Shan Jeng; Ming-Tsang Lee

    2014-01-01

    This study uses the T3Ster transient thermal resistance measuring device to investigate the effects to heat transfer performances from different LED crystal grains, packaging methods and heat-sink substrates through the experimental method. The experimental parameters are six different types of LED modules that are made alternatively with the crystal grain structure, the die attach method and the carrying substrate. The crystal grain structure includes the lateral type, flip chip type and ver...

  18. Interplay between affect and arousal in recognition memory.

    Science.gov (United States)

    Greene, Ciara M; Bahri, Pooja; Soto, David

    2010-07-23

    Emotional states linked to arousal and mood are known to affect the efficiency of cognitive performance. However, the extent to which memory processes may be affected by arousal, mood or their interaction is poorly understood. Following a study phase of abstract shapes, we altered the emotional state of participants by means of exposure to music that varied in both mood and arousal dimensions, leading to four different emotional states: (i) positive mood-high arousal; (ii) positive mood-low arousal; (iii) negative mood-high arousal; (iv) negative mood-low arousal. Following the emotional induction, participants performed a memory recognition test. Critically, there was an interaction between mood and arousal on recognition performance. Memory was enhanced in the positive mood-high arousal and in the negative mood-low arousal states, relative to the other emotional conditions. Neither mood nor arousal alone but their interaction appears most critical to understanding the emotional enhancement of memory.

  19. High quality Danish design with intelligent LED light. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Paul Michael; Dam-Hansen, C.; Thestrup, B.; Pedersen, Henrik (Technical Univ. of Denmark, DTU Fotonik, Roskilde (Denmark)); Olsen, Jesper (JesperOlsen ApS, Frederiksberg (Denmark)); Falleboe, H.; Andersen, Jakob (MORFOSO, Copenhagen (Denmark))

    2010-02-15

    Based on the results achieved in a previous project, which enabled a number of designers to be trained in the potential of LED lighting technology, this project developed intelligent LED fixtures for work purposes and for private homes. The two types of fixtures both meet the original project objective of good colour rendition with Ra indices above 90 and colour temperatures variable within the interval 3,300 to 4,400 K. Furthermore, with luminous efficacies of 60 lumen/W, both fixtures have energy efficiencies exceeding that of an average energy-friendly light source. (ln)

  20. Controlling excitons. Concepts for phosphorescent organic LEDs at high brightness

    Energy Technology Data Exchange (ETDEWEB)

    Reineke, Sebastian

    2009-11-15

    }(acac). Compared to Ir(ppy){sub 3}, this emitter has a much smaller ground state dipole moment, suggesting that the improved performance is a result of weaker aggregation in the mixed film. The knowledge gained in the investigation of triplet-triplet annihilation is further used to develop a novel emission layer design for white organic LEDs. It comprises three phosphorescent emitters for blue, green, and red emission embedded in a multilayer architecture. The key feature of this concept is the matrix material used for the blue emitter FIrpic: Its triplet energy is in resonance with the FIrpic excited state energy which enables low operating voltages and high power efficiencies by reducing thermal relaxation. In order to further increase the device efficiency, the OLED architecture is optically optimized using high refractive index substrates and thick electron transport layers. These devices reach efficiencies which are on par with fluorescent tubes - the current efficiency benchmark for light sources. (orig.)

  1. Nanoscale carrier injectors for high luminescence Si-based LEDs

    NARCIS (Netherlands)

    Piccolo, G.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2012-01-01

    In this paper we present the increased light emission for Sip–i–n light emitting diodes (LEDs) by geometrical scaling of the injector size for p- and n- type carriers. Simulations and electrical and optical characteristics of our realized devices support our findings. Reducing the injector size

  2. Nanoscale carrier injectors for high luminescence Si-based LEDs

    NARCIS (Netherlands)

    Piccolo, G.; Kovalgin, A.Y.; Schmitz, J.

    2012-01-01

    In this paper we present the increased light emission for Sip–i–n light emitting diodes (LEDs) by geometrical scaling of the injector size for p- and n- type carriers. Simulations and electrical and optical characteristics of our realized devices support our findings. Reducing the injector size decr

  3. High Efficacy Green LEDs by Polarization Controlled MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2013-03-31

    Amazing performance in GaInN/GaN based LEDs has become possible by advanced epitaxial growth on a wide variety of substrates over the last decade. An immediate push towards product development and worldwide competition for market share have effectively reduced production cost and generated substantial primary energy savings on a worldwide scale. At all times of the development, this economic pressure forced very fundamental decisions that would shape huge industrial investment. One of those major aspects is the choice of epitaxial growth substrate. The natural questions are to what extend a decision for a certain substrate will limit the ultimate performance and to what extent, the choice of a currently more expensive substrate such as native GaN could overcome any of the remaining performance limitations. Therefore, this project has set out to explore what performance characteristic could be achieved under the utilization of bulk GaN substrate. Our work was guided by the hypotheses that line defects such as threading dislocations in the active region should be avoided and the huge piezoelectric polarization needs to be attenuated – if not turned off – for higher performing LEDs, particularly in the longer wavelength green and deep green portions of the visible spectrum. At their relatively lower performance level, deep green LEDs are a stronger indicator of relative performance improvements and seem particular sensitive to the challenges at hand.

  4. Heat Transfer Characteristics in High Power LED Packaging

    Directory of Open Access Journals (Sweden)

    Chi-Hung Chung

    2014-03-01

    Full Text Available This study uses the T3Ster transient thermal resistance measuring device to investigate the effects to heat transfer performances from different LED crystal grains, packaging methods and heat-sink substrates through the experimental method. The experimental parameters are six different types of LED modules that are made alternatively with the crystal grain structure, the die attach method and the carrying substrate. The crystal grain structure includes the lateral type, flip chip type and vertical type. The die attach method includes silver paste and the eutectic structure. The carrying substrates are aluminum oxide (Alumina and aluminum nitride (AIN ceramic substrates and metal core PCB (MCPCB. The experimental results show that, under the conditions of the same crystal grain and die attach method, the thermal resistance values for the AIN substrate and the Alumina substrate are 2.1K/W and 5.1K/W, respectively and the total thermal resistance values are 7.3K/W and 10.8K/W. Compared to the Alumina substrate, the AIN substrate can effectively lower the total thermal resistance value by 32.4%. This is because the heat transfer coefficient of the AIN substrate is higher than that of the Alumina substrate, thus effectively increasing its thermal conductivity. In addition, under the conditions of the same crystal grain and the same substrate, the packaging methods are using silver paste and the eutectic structure for die attach. Their thermal resistance values are 5.7K/W and 2.7K/W, respectively, with a variance of 3K/W. Comparisons of the crystal grain structure show that the thermal resistance for the flip chip type is lower than that of the traditional lateral type by 0.9K/W. This is because the light emitting layer of the flip chip crystal grain is closer to the heat-sink substrate, shortening the heat dissipation route, and thus lowering the thermal resistance value. For the total thermal resistance, the crystal grain structure has a lesser

  5. Arousal Cues Arousal-Related Material in Memory: Implications for Understanding Effects of Mood on Memory.

    Science.gov (United States)

    Clark, Margaret S.; And Others

    1983-01-01

    Discusses research showing that material people learn when in a high arousal state and material they learn when in a normal arousal state is subsequently best recalled when they are in a similar arousal state. Speculates that this effect may partially underlie mood cuing, mood-related material from memory. (EKN)

  6. Characteristics of High-Efficient InGaN-Based White LED Lighting

    Science.gov (United States)

    2000-07-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO 11311 TITLE: Characteristics of High-Efficient InGaN -Based White LED ...thru ADP011332 UNCLASSIFIED Characteristics of high-efficient InGaN -based white LED lighting Yuji Uchida’, Tatsumi Setomoto’, Tsunemasa Taguchi...characteristics of an efficient white LEDs lighting source, which is composed of cannon-ball type 10 cd-class InGaN -based white LEDs , are described. It is

  7. Computer Modeling and Simulation Evaluation of High Power LED Sources for Secondary Optical Design

    Institute of Scientific and Technical Information of China (English)

    SU Hong-dong; WANG Ya-jun; DONG Ji-yang; CHEN Zhong

    2007-01-01

    Proposed and demonstrated is a novel computer modeling method for high power light emitting diodes(LEDs). It contains geometrical structure and optical property of high power LED as well as LED dies definition with its spatial and angular distribution. Merits and non-merits of traditional modeling methods when applied to high power LEDs based on secondary optical design are discussed. Two commercial high power LEDs are simulated using the proposed computer modeling method. Correlation coefficient is proposed to compare and analyze the simulation results and manufacturing specifications. The source model is precisely demonstrated by obtaining above 99% in correlation coefficient with different surface incident angle intervals.

  8. Integrated Automotive High-Power LED-Lighting Systems in 3D-MID Technology

    NARCIS (Netherlands)

    Thomas, W.

    2014-01-01

    The growing energy consumption of lighting as well as rising luminous efficacies and -fluxes of high-power Light Emitting Diodes (LEDs) have contributed to the widespread use of LEDs in modern lighting systems. One of the most prominent users of the LED-technology is automotive (exterior) lighting.

  9. Highly-efficient, tunable green, phosphor-converted LEDs using a long-pass dichroic filter and a series of orthosilicate phosphors for tri-color white LEDs.

    Science.gov (United States)

    Oh, Ji Hye; Oh, Jeong Rok; Park, Hoo Keun; Sung, Yeon-Goog; Do, Young Rag

    2012-01-02

    This study introduces a long-pass dichroic filter (LPDF) on top of a phosphor-converted LED (pc-LED) packing associated with each corresponding tunable orthosilicate ((Ba,Sr)2SiO4:Eu) phosphor in order to fabricate tunable green pc-LEDs. These LPDF-capped green pc-LEDs provide luminous efficacies between 143–173 lm/W at 60 mA in a wavelength range between 515 and 560 nm. These tunable green pc-LEDs can replace green semiconductor-type III-V LEDs, which present challenges with respect to generating high luminous efficacy. We also introduce the highly-efficient tunable green pc-LEDs into tri-color white LED systems that combine an InGaN blue LED and green/red full down-converted pc-LEDs. The effect of peak wavelength in the tunable green pc-LEDs on the optical properties of a tri-color package white LED is analyzed to determine the proper wavelength of green color for tri-color white LEDs. The tri-color white LED provides excellent luminous efficacy (81.5–109 lm/W) and a good color rendering index (64–87) at 6500 K of correlated color temperature (CCT) with the peak wavelength of green pc-LEDs. The luminous efficacy of the LPDF-capped green monochromatic pc-LED and tri-color package with tunable green pc-LEDs can be increased by improving the external quantum efficiency of blue LEDs and the conversion efficiency of green pc-LEDs.

  10. Multichip on Aluminum Metal Plate Technology for High Power LED Packaging

    Institute of Scientific and Technical Information of China (English)

    Choong-mo NAM; Mi-hee JI

    2010-01-01

    Multichip on Aluminum Metal Plate(MOAMP) technology with simple structure and low thermal resistance is developed for effective heat removal of Light Emitting Diode(LED) p-n junction and LED lighting module to have high reliability. The thermal resistance of LED modules was numerical and experimental. Thermal resistance from the junction to aluminum metal plate, considering input power of LED module using MOAMP technology, is 3.02 K/W, 3.23 K/W for the measured and calculated, respectively. We expect that the reported MOAMP technology with low thermal resistance will be a promising solution for high power LED lighting modules.

  11. High Efficiency LED Lamp for Solid-State Lighting

    Energy Technology Data Exchange (ETDEWEB)

    James Ibbetson

    2006-12-31

    This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency, solid-state lamps based on gallium nitride/silicon carbide light-emitting diodes. Novel chip designs and fabrication processes are described for a new type of nitride light-emitting diode with the potential for very high efficiency. This work resulted in the demonstration of blue light-emitting diodes in the one watt class that achieved up to 495 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 51% and 45%, respectively. When combined with a phosphor in Cree's 7090 XLamp package, these advanced blue-emitting devices resulted in white light-emitting diodes whose efficacy exceeded 85 lumens per watt. In addition, up to 1040 lumens at greater than 85 lumens per watt was achieved by combining multiple devices to make a compact white lamp module with high optical efficiency.

  12. Veterans’ Health Care: Limited Progress Made to Address Concerns That Led to High Risk Designation

    Science.gov (United States)

    2017-03-15

    VETERANS’ HEALTH CARE Limited Progress Made to Address Concerns That Led to High-Risk Designation Statement of Debra A...Progress Made to Address Concerns That Led to High-Risk Designation What GAO Found The Department of Veterans Affairs (VA) has taken action to...establishing a task force, working groups, and a governance structure for addressing the issues that led to the high-risk designation. VA provided

  13. High-power LEDs influence on germination rate of tomato seeds

    Science.gov (United States)

    Tudora, Cătălina; Ristici, M.; Ristici, Esofina

    2007-08-01

    Artificial lighting for plants cultivation is an important factor that can determine the nutritional quality of vegetables. The improvement of quality is determined by the emission spectrum of LED, suitable for vegetables. This spectrum values must be inside the solar ones. So, by using red high-power LEDs we can supplement the conventional lighting (ex. HPS) and we can enrich the red light from the emission light. We have used a special device that has 200 high-power red LEDs, having emission wavelength in 640-670 nm range, which is presented below. Using red LEDs on tomato seeds, we can observe that the germination rate significantly increased.

  14. A high-performance stand-alone solar PV power system for LED lighting

    KAUST Repository

    Huang, B. J.

    2010-06-01

    The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power- Point- Operation) design is employed in system design to eliminate MPPT. A feedback control system using pulse width modulation (PWM) technique was developed for battery charging control which can increase the charging capacity by 78%. For high-efficiency lighting, the LED is directly driven by battery using a PWM discharge control to eliminate a DC/DC converter. Two solar-powered LED lighting systems (50W and 100W LED) were built. The long-term outdoor tests have shown that the loss of load probability for full-night lighting requirement is zero for 50W LED and 3.6% for 100W LED. © 2010 IEEE.

  15. Degradation Physics of High Power LEDs in Outdoor Environment and the Role of Phosphor in the degradation process

    OpenAIRE

    Preetpal Singh; Cher Ming Tan

    2016-01-01

    A moisture- electrical ? temperature (MET) test is proposed to evaluate the outdoor reliability of high power blue LEDs, with and without phosphor, and to understand the degradation physics of LEDs under the environment of combined humidity, temperature and electrical stresses. The blue LEDs with phosphor will be the high power white LEDs. Scanning acoustic microscopy is used to examine the resulted delamination during this test for the LEDs. The degradation mechanisms of blue LEDs (LEDs with...

  16. High-power InGaN LEDs: present status and future prospects

    Science.gov (United States)

    Hahn, B.; Weimar, A.; Peter, M.; Baur, J.

    2008-02-01

    The ThinGaN ® technology of OSRAM Opto semiconductors enables high power LEDs with wall plug efficiencies of currently up to 50%, enabling efficacies of > 100lm/W for white and green LEDs. The good scalability of the technology enables devices which deliver high luminous flux. The future limitations regarding efficacy of white LED can be estimated to be 150lm/W for high color rendering. Besides efficiency long term stability and high temperature capability are requirements for market adoption

  17. High quality GaN-based LED epitaxial layers grown in a homemade MOCVD system

    Institute of Scientific and Technical Information of China (English)

    Yin Haibo; Wang Xiaoliang; Ran Junxue; Hu Guoxin; Zhang Lu; Xiao Hongling; Li Jing; Li Jinmin

    2011-01-01

    A homemade 7 × 2 inch MOCVD system is presented.With this system,high quality GaN epitaxial layers,InGaN/GaN multi-quantum wells and blue LED structural epitaxial layers have been successfully grown.The non-uniformity of undoped GaN epitaxial layers is as low as 2.86%.Using the LED structural epitaxial layers,blue LED chips with area of 350 × 350μm2 were fabricated.Under 20 mA injection current,the optical output power of the blue LED is 8.62 mW.

  18. Development of high-frame-rate LED panel and its applications for stereoscopic 3D display

    Science.gov (United States)

    Yamamoto, H.; Tsutsumi, M.; Yamamoto, R.; Kajimoto, K.; Suyama, S.

    2011-03-01

    In this paper, we report development of a high-frame-rate LED display. Full-color images are refreshed at 480 frames per second. In order to transmit such a high frame-rate signal via conventional 120-Hz DVI, we have introduced a spatiotemporal mapping of image signal. A processor of LED image signal and FPGAs in LED modules have been reprogrammed so that four adjacent pixels in the input image are converted into successive four fields. The pitch of LED panel is 20 mm. The developed 480-fps LED display is utilized for stereoscopic 3D display by use of parallax barrier. The horizontal resolution of a viewed image decreases to one-half by the parallax barrier. This degradation is critical for LED because the pitch of LED displays is as large as tens of times of other flat panel displays. We have conducted experiments to improve quality of the viewed image through the parallax barrier. The improvement is based on interpolation by afterimages. It is shown that the HFR LED provides detailed afterimages. Furthermore, the HFR LED has been utilized for unconscious imaging, which provide a sensation of discovery of conscious visual information from unconscious images.

  19. High Efficiency SEPIC Converter For High Brightness Light Emitting Diodes (LEDs) System

    OpenAIRE

    Qin, Yaxiao

    2012-01-01

    ABSTRACT This thesis presents an investigation into the characteristics of and driving methods for light emitting diode (LED) lamp system. A comprehensive overview on the lighting development is proposed. The characteristic of the light emitting diode (LED) lamp is described and the requirements of the ballast for the light emitting diode (LED) lamp are presented. Although LED lamps have longer lifetime than fluorescent lamps, the short lifetime limitation of LED driver imposed by ele...

  20. Phosphor-in-glass for high-powered remote-type white AC-LED.

    Science.gov (United States)

    Lin, Hang; Wang, Bo; Xu, Ju; Zhang, Rui; Chen, Hui; Yu, Yunlong; Wang, Yuansheng

    2014-12-10

    The high-powered alternating current (AC) light-emitting diode (LED) (AC-LED), featuring low cost, high energy utilization efficiency, and long service life, will become a new economic growth point in the field of semiconductor lighting. However, flicker of AC-LED in the AC cycles is not healthy for human eyes, and therefore need to be restrained. Herein we report an innovation of persistent "phosphor-in-glass" (PiG) for the remote-type AC-LED, whose afterglow can be efficiently activated by the blue light. It is experimentally demonstrated that the afterglow decay of PiG in the microsecond range can partly compensate the AC time gap. Moreover, the substitution of inorganic glass for organic resins or silicones as the encapsulants would bring out several technological benefits to AC-LED, such as good heat-dissipation, low glare, and excellent physical/chemical stability.

  1. Novel high refractive index, thermally conductive additives for high brightness white LEDs

    Science.gov (United States)

    Hutchison, Richard Stephen

    In prior works the inclusion of nanoparticle fillers has typically been shown to increase the thermal conductivity or refractive index of polymer nanocomposites separately. High refractive index zirconia nanoparticles have already proved their merit in increasing the optical efficiency of encapsulated light emitting diodes. However, the thermal properties of zirconia-silicone nanocomposites have yet to be investigated. While phosphor-converted light emitting diodes are at the forefront of solid-state lighting technologies for producing white light, they are plagued by efficiency losses due to excessive heating at the semiconductor die and in and around the phosphor particles, as well as photon scattering losses in the phosphor layer. It would then be of great interest if the high refractive index nanoparticles were found to both be capable of increasing the refractive index, thus reducing the optical scattering, and also the thermal conductivity, channeling more heat away from the LED die and phosphors, mitigating efficiency losses from heat. Thermal conductance measurements on unfilled and nanoparticle loaded silicone samples were conducted to quantify the effect of the zirconia nanoparticle loading on silicone nanocomposite thermal conductivity. An increase in thermal conductivity from 0.27 W/mK to 0.49 W/mK from base silicone to silicone with 33.5 wt% zirconia nanoparticles was observed. This trend closely mirrored a basic rule of mixtures prediction, implying a further enhancement in thermal conductivity could be achieved at higher nanoparticle loadings. The optical properties of transparency and light extraction efficiency of these composites were also investigated. While overall the zirconia nanocomposite showed good transparency, there was a slight decrease at the shorter wavelengths with increasing zirconia content. For longer wavelength LEDs, such as green or red, this might not matter, but phosphor-converted white LEDs use a blue LED as the photon source

  2. Monolithic blue LED series arrays for high-voltage AC operation

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping [Satellite Venture Business Laboratory, University of Tokushima, Tokushima 770-8506 (Japan); Sato, Hisao; Mizobuchi, Takashi; Morioka, Kenji; Kawano, Shunsuke; Muramoto, Yoshihiko; Sato, Daisuke; Sakai, Shiro [Nitride Semiconductor Co. Ltd., Naruto, Tokushima 771-0360 (Japan); Lee, Young-Bae; Ohno, Yasuo [Department of Electrical and Electronic Engineering, University of Tokushima, Tokushima 770-8506 (Japan)

    2002-12-16

    Design and fabrication of monolithic blue LED series arrays that can be operated under high ac voltage are described. Several LEDs, such as 3, 7, and 20, are connected in series and in parallel to meet ac operation. The chip size of a single device is 150 {mu}m x 120 {mu}m and the total size is 1.1 mm x 1 mm for a 40(20+20) LED array. Deep dry etching was performed as device isolation. Two-layer interconnection and air bridge are utilized to connect the devices in an array. The monolithic series array exhibit the expected operation function under dc and ac bias. The output power and forward voltage are almost proportional to LED numbers connected in series. On-wafer measurement shows that the output power is 40 mW for 40(20+20) LED array under ac 72 V. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  3. A high efficiency and power factor, segmented linear constant current LED driver

    Science.gov (United States)

    Yongyuan, Li; Wei, Guo; Zhangming, Zhu

    2015-04-01

    A high efficiency, high power factor, and linear constant current LED driver based on adaptive segmented linear architecture is presented. When the input voltage varied, the proposed LED driver automatically switched over LED strings according to the segmented LED voltage drop, which increased the LED lighting time. The efficiency and power factor are improved, while the system design is simplified by this control scheme. Without the usage of electrolytic capacitor and magnetic components, the proposed driver possesses advantages of smaller size, longer lifetime and lower cost over others. The proposed driver is implemented in 0.8 μm 5 V/40 V HVCMOS process, which occupies an active area of 820 × 920 μm2. The measured results show that the average value of the internal reference voltage is 500 ± 7 mV, with a standard deviation of only 4.629 mV, thus LED current can be set accurately. Under 220 V root mean square 50 Hz utility voltage and the number ratio of the three LED strings being 47 : 17 : 16, the system can realize a high power factor of 0.974 and power conversion efficiency of 93.4%. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033).

  4. Spectral and luminous efficacy change of high-power LEDs under different dimming methods

    Science.gov (United States)

    Gu, Yimin; Narendran, Nadarajah; Dong, Tianming; Wu, Huiying

    2006-08-01

    Dimming is an important and necessary feature for light sources used in general lighting applications. An experimental study was conducted to quantify the spectral and luminous efficacy change of high-power colored and pc-white LEDs under continuous current reduction (CCR) and pulse-width modulation (PWM) dimming schemes. For InGaN-based blue, green, and pc-white LEDs, the peak wavelength shifts were in opposite directions for the two dimming schemes. The peak wavelength showed a blue shift with increased current, most likely due to band filling and QCSE dominated effects. InGaN LEDs exhibited red shifts with increased duty cycle, which is dominated by junction heat. AlInGaP red LEDs show mainly thermal-induced red shift with increased current or duty cycle. In addition, the luminous efficacy was always higher for the CCR dimming scheme at dimmed levels, irrespective of the LED type. Keywords: Light-emitting diodes (LEDs), white LEDs, mixed-color white LEDs, pulse-width modulation (PWM), continuous current reduction (CCR), peak wavelength shift, luminous efficacy

  5. Measuring the temperature of high-luminous exitance surfaces with infrared thermography in LED applications

    Science.gov (United States)

    Perera, Indika U.; Narendran, Nadarajah

    2016-09-01

    Recently, light-emitting diode (LED) lighting systems have become popular due to their increased system performance. LED lighting system performance is affected by heat; therefore, it is important to know the temperature of a target surface or bulk medium in the LED system. In-situ temperature measurements of a surface or bulk medium using intrusive methods cause measurement errors. Typically, thermocouples are used in these applications to measure the temperatures of the various components in an LED system. This practice leads to significant errors, specifically when measuring surfaces with high-luminous exitance. In the experimental study presented in this paper, an infrared camera was used as an alternative to temperature probes in measuring LED surfaces with high-luminous exitance. Infrared thermography is a promising method because it does not respond to the visible radiation spectrum in the range of 0.38 to 0.78 micrometers. Usually, infrared thermography equipment is designed to operate either in the 3 to 5 micrometer or the 7 to 14 micrometer wavelength bands. To characterize the LED primary lens, the surface emissivity of the LED phosphor surface, the temperature dependence of the surface emissivity, the temperature of the target surface compared to the surrounding temperature, the field of view of the target, and the aim angle to the target surface need to be investigated, because these factors could contribute towards experimental errors. In this study, the effects of the above-stated parameters on the accuracy of the measured surface temperature were analyzed and reported.

  6. High-power UV-LED degradation: Continuous and cycled working condition influence

    Science.gov (United States)

    Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

    2015-09-01

    High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

  7. InGaN micro-LED-pillar as the building block for high brightness emitters

    KAUST Repository

    Shen, Chao

    2013-01-01

    In summary, we confirmed the improved electrical and optical characteristics, with reduced efficiency droop in InGaN μLED-pillars when these devices were scaled down in size. We demonstrated that strain relief contributed to further improvement in EQE characteristics in small InGaN μLED-pillars (D < 50 μm), apart from the current spreading effect. The μLED-pillar can be deployed as the building block for large effective-area, high brightness emitter. © 2013 IEEE.

  8. Heat dissipation performance of a high-brightness LED package assembly using high-thermal conductivity filler.

    Science.gov (United States)

    Yung, K C; Liem, H; Choy, H S

    2013-12-10

    This paper presents a thermal analysis and experimental validation of natural convective heat transfer of a high-brightness light-emitting diode (LED) package assembly. The substrate materials used in the LED package assembly were filled and doped using boron nitride (BN) filler. The thermal conductivity of the BN-filled substrate was measured. The temperature distribution and heat flow of the LED package were assessed by thermal profile measurement using an infrared (IR) camera and thermocouples. In addition, the heat transfer process of the LED package assembly in natural convection was also simulated using the computational fluid dynamics method. The optical performance of the LED package was monitored and investigated with various filler contents. The heat conduction mechanism in the substrate was analyzed. IR thermogram showed that the BN-doped substrate could effectively lower the surface temperature of the LED package by 21.5°C compared with the traditional FR4 substrate. According to the IESNA LM 80 lifetime testing method, reduction in LED temperature can prolong the LED's lifetime by 19,000 h. The optical performance of the LED package assembly was also found to be improved significantly in lighting power by 10%. As a result, the overall heat dissipation capability of the LED package to the surrounding is enhanced, which improves the LED's efficacy.

  9. Determining contrast sensitivity functions for monochromatic light emitted by high-brightness LEDs

    Science.gov (United States)

    Ramamurthy, Vasudha; Narendran, Nadarajah; Freyssinier, Jean Paul; Raghavan, Ramesh; Boyce, Peter

    2004-01-01

    Light-emitting diode (LED) technology is becoming the choice for many lighting applications that require monochromatic light. However, one potential problem with LED-based lighting systems is uneven luminance patterns. Having a uniform luminance distribution is more important in some applications. One example where LEDs are becoming a viable alternative and luminance uniformity is an important criterion is backlighted monochromatic signage. The question is how much uniformity is required for these applications. Presently, there is no accepted metric that quantifies luminance uniformity. A recent publication proposed a method based on digital image analysis to quantify beam quality of reflectorized halogen lamps. To be able to employ such a technique to analyze colored beams generated by LED systems, it is necessary to have contrast sensitivity functions (CSFs) for monochromatic light produced by LEDs. Several factors including the luminance, visual field size, and spectral power distribution of the light affect the CSFs. Although CSFs exist for a variety of light sources at visual fields ranging from 2 degrees to 20 degrees, CSFs do not exist for red, green, and blue light produced by high-brightness LEDs at 2-degree and 10-degree visual fields and at luminances typical for backlighted signage. Therefore, the goal of the study was to develop a family of CSFs for 2-degree and 10-degree visual fields illuminated by narrow-band LEDs at typical luminances seen in backlighted signs. The details of the experiment and the results are presented in this manuscript.

  10. High-Power 365 nm UV LED Mercury Arc Lamp Replacement for Photochemistry and Chemical Photolithography.

    Science.gov (United States)

    Hölz, K; Lietard, J; Somoza, M M

    2017-01-03

    Ultraviolet light emitting diodes (UV LEDs) have become widespread in chemical research as highly efficient light sources for photochemistry and photopolymerization. However, in more complex experimental setups requiring highly concentrated light and highly spatially resolved patterning of the light, high-pressure mercury arc lamps are still widely used because they emit intense UV light from a compact arc volume that can be efficiently coupled into optical systems. Advances in the deposition and p-type doping of gallium nitride have recently permitted the manufacture of UV LEDs capable of replacing mercury arc lamps also in these applications. These UV LEDs exceed the spectral radiance of mercury lamps even at the intense I-line at 365 nm. Here we present the successful exchange of a high-pressure mercury arc lamp for a new generation UV LED as a light source in photolithographic chemistry and its use in the fabrication of high-density DNA microarrays. We show that the improved light radiance and efficiency of these LEDs offer substantial practical, economic and ecological advantages, including faster synthesis, lower hardware costs, very long lifetime, an >85-fold reduction in electricity consumption and the elimination of mercury waste and contamination.

  11. Injection molding of high precision optics for LED applications made of liquid silicone rubber

    Energy Technology Data Exchange (ETDEWEB)

    Hopmann, Christian; Röbig, Malte [Institute of Plastics Processing (IKV), RWTH Aachen University, Pontstraße 49, 52062 Aachen (Germany)

    2016-03-09

    Light Emitting Diodes (LED) conquer the growing global market of lighting technologies. Due to their advantages, they are increasingly used in consumer products, in lighting applications in the home and in the mobility sector as well as in industrial applications. Particularly, with regard to the increasing use of high-power LED (HP-LED) the materials in the surrounding area of the light emitting semiconductor chip are of utmost importance. While the materials behind the semiconductor chip are optimized for maximum heat dissipation, the materials currently used for the encapsulation of the semiconductor chip (primary optics) and the secondary optics encounter their limits due to the high temperatures. In addition certain amounts of blue UV radiation degrade the currently used materials such as epoxy resins or polyurethanes for primary optics. In the context of an ongoing joint research project with various partners from the industry, an innovative manufacturing method for high precision optics for LED applications made of liquid silicone rubber (LSR) is analyzed at the Institut of Plastics Processing (IKV), Aachen. The aim of this project is to utilize the material-specific advantages of high transparent LSR, especially the excellent high temperature resistance and the great freedom in design. Therefore, a high integrated injection molding process is developed. For the production of combined LED primary and secondary optics a LED board is placed in an injection mold and overmolded with LSR. Due to the integrated process and the reduction of subcomponents like the secondary optics the economics of the production process can be improved significantly. Furthermore combined LED optics offer an improved effectiveness, because there are no losses of the light power at the transition of the primary and secondary optics.

  12. The High-efficiency LED Driver for Visible Light Communication Applications

    Science.gov (United States)

    Gong, Cihun-Siyong Alex; Lee, Yu-Chen; Lai, Jyun-Liang; Yu, Chueh-Hao; Huang, Li Ren; Yang, Chia-Yen

    2016-08-01

    This paper presents a LED driver for VLC. The main purpose is to solve the low data rate problem used to be in switching type LED driver. The GaN power device is proposed to replace the traditional silicon power device of switching LED driver for the purpose of increasing switching frequency of converter, thereby increasing the bandwidth of data transmission. To achieve high efficiency, the diode-connected GaN power transistor is utilized to replace the traditional ultrafast recovery diode used to be in switching type LED driver. This work has been experimentally evaluated on 350-mA output current. The results demonstrate that it supports the data of PWM dimming level encoded in the PPM scheme for VLC application. The experimental results also show that system’s efficiency of 80.8% can be achieved at 1-Mb/s data rate.

  13. Fabrication of High-power White LEDs and White Light Uniformity Testing

    Institute of Scientific and Technical Information of China (English)

    YU Xin-mei; RAO Hai-bo; HU Yue; LI Jun-fei; HOU Bin

    2007-01-01

    As the blue and yellow lights are complementary colors,a blue InGaN LED chip is coated by a yellow phosphor film to generate white light based on luminescence conversion mechanism.The emitted light of a blue LED is used as the primary source for exciting fluorescent material such as cerium doped yttrium aluminum garnet with the formula Y3Al5O12:Ce3+(in short:YAG:Ce3+).The matching of the spectrum of the blue LED chips and the YAG:Ce3+ yellow phosphor is studied to improve the conversion efficiency.The packaging methods and manufacturing processes for high-power single-chip-white-LEDs are introduced.The uniformity of the output white light is investigated.Based on the characteristics of the high-power white LEDs,some approaches and processes are suggested to improve the light uniformity when they are fabricated.The effectiveness of those approaches on the improvement of LEDs is discussed in detail and some interesting conclusions are also presented.

  14. Testing a high-power LED based light source for hyperspectral imaging microscopy

    Science.gov (United States)

    Klomkaew, Phiwat; Mayes, Sam A.; Rich, Thomas C.; Leavesley, Silas J.

    2017-02-01

    Our lab has worked to develop high-speed hyperspectral imaging systems that scan the fluorescence excitation spectrum for biomedical imaging applications. Hyperspectral imaging can be used in remote sensing, medical imaging, reaction analysis, and other applications. Here, we describe the development of a hyperspectral imaging system that comprised an inverted Nikon Eclipse microscope, sCMOS camera, and a custom light source that utilized a series of high-power LEDs. LED selection was performed to achieve wavelengths of 350-590 nm. To reduce scattering, LEDs with low viewing angles were selected. LEDs were surface-mount soldered and powered by an RCD. We utilized 3D printed mounting brackets to assemble all circuit components. Spectraradiometric calibration was performed using a spectrometer (QE65000, Ocean Optics) and integrating sphere (FOIS-1, Ocean Optics). Optical output and LED driving current were measured over a range of illumination intensities. A normalization algorithm was used to calibrate and optimize the intensity of the light source. The highest illumination power was at 375 nm (3300 mW/cm2), while the lowest illumination power was at 515, 525, and 590 nm (5200 mW/cm2). Comparing the intensities supplied by each LED to the intensities measured at the microscope stage, we found there was a great loss in power output. Future work will focus on using two of the same LEDs to double the power and finding more LED and/or laser diodes and chips around the range. This custom hyperspectral imaging system could be used for the detection of cancer and the identification of biomolecules.

  15. Increase of energy efficiency in horticultural tissue culture with high-power-LED lighting systems; Energieeffizienzsteigerung pflanzlicher In-vitro-Kulturverfahren mit Hochleistungs-LED-Belichtungssystemen

    Energy Technology Data Exchange (ETDEWEB)

    Bornwasser, Thorsten

    2011-07-01

    The lighting of tissue cultures is one of the main cost factors in growing rooms due to the high energy need. A lighting system with high-power light-emitting diodes (HP-LEDs) was tested as an alternative to the conventionally used fluorescent tubes. Therefore the HP-LED-types royal-blue, red, and cool white were used to create different spectral outputs. The photon flux yield, level of efficiency, and spectral shift of the single HP-LEDs were measured beforehand at different operating conditions (i.e. increasing current and junction temperature). The energy efficiency of the HP-LED lighting system was determined at 0.83 {mu}mol W{sup -1}s{sup -1} with the same shelf board distance (300 mm) and average PPFD on the exposed surface as compared to the control lighting system. The energy efficiency of the fluorescent lighting system could reach a maximum value of 0.68 {mu}mol W{sup -1}s{sup -1}. In addition to the reduced energy needs, HP-LED lighting systems reduce the need for cooling energy in culture rooms to regulate the room temperature. HP-LED lighting systems allow the reduction of the shelf board distance due to the small mass volume of LEDs and diminished radiant heat output towards the plant. The lower shelf board distance led to an additional increase of the energy efficiency up to 1.16 {mu}mol W{sup -1}s{sup -1} at a distance of 210 mm. Simultaneously the PPFD distribution was more regular than under the exposure with a fluorescent tube. Beside the increase of energy efficiency, HP-LEDs facilitate the control of the spectral composition. The spectral output can be adjusted to the plants' needs and thereby permit a more optimal production and influence the plant morphology (Nhut und Na, 2010; Morrow, 2008). Various plant tissue cultures and their response to different spectral compositions were investigated with the developed HP-LED lighting system. For none of the tested cultures could a preference for one of the spectral compositions be determined

  16. Interplay between affect and arousal in recognition memory.

    Directory of Open Access Journals (Sweden)

    Ciara M Greene

    Full Text Available BACKGROUND: Emotional states linked to arousal and mood are known to affect the efficiency of cognitive performance. However, the extent to which memory processes may be affected by arousal, mood or their interaction is poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: Following a study phase of abstract shapes, we altered the emotional state of participants by means of exposure to music that varied in both mood and arousal dimensions, leading to four different emotional states: (i positive mood-high arousal; (ii positive mood-low arousal; (iii negative mood-high arousal; (iv negative mood-low arousal. Following the emotional induction, participants performed a memory recognition test. Critically, there was an interaction between mood and arousal on recognition performance. Memory was enhanced in the positive mood-high arousal and in the negative mood-low arousal states, relative to the other emotional conditions. CONCLUSIONS/SIGNIFICANCE: Neither mood nor arousal alone but their interaction appears most critical to understanding the emotional enhancement of memory.

  17. Female Sexual Arousal Disorders

    DEFF Research Database (Denmark)

    Giraldi, Annamaria; Rellini, Alessandra H; Pfaus, James;

    2012-01-01

    in one entity. Persistent genital arousal disorder (PGAD) is a new entity which is suggested to be defined as Restless Genital Syndrome. Aims.  The aims of this brief review are to give definitions of the different types of FSAD, describe their aetiology, prevalence and comorbidity with somatic....... Results.  Female Arousal Disorders have been defined in several ways with focus on the genital or subjective response or a combination of both. The prevalence varies and increases with increasing age, especially at the time of menopause, while distress decreases with age. Arousal disorders are often...... comorbid with other sexual problems and are of biopsychosocial etiology. In the assessment, a thorough sexological history as well as medical and gynecological history and examination are recommended. Treatment should be based on of the symptoms, clinical findings and, if possibly, on underlying etiology...

  18. 大功率 LED 散热结构的优化设计%Optimization Design Based on the Heat Radiation Structure of High -power LED

    Institute of Scientific and Technical Information of China (English)

    马验宗; 张忠山; 智郁雯; 陈鹏宇; 严一民

    2015-01-01

    大功率 LED 与传统光源相比优势明显,应用前景非常广阔。但由于体积小,发热集中,LED 芯片不能承受高温等原因,散热问题成为了制约大功率 LED 发展的主要原因。该文结合三维模型设计软件 Pro /Engineer 5.0和流体传热分析软件FloEFD PRO12.1对5 W 的 LED 的散热模型进行建模和热仿真,运用控制变量的方法来探索散热器翅片厚度、曲率及微结构对散热性能的影响规律,并依据规律对散热器结构进行优化。%Compared to the traditional light source,high -power LED retains decided advantages,along with wide application pros-pects.However,heat dissipation has been the major obstacle to the further development of high power LED because of its small vol-ume,heat concentration,and bad resistance to high temperature of the LED chip.Through combining the 3D model design software Pro /Engineer 5.0 heat transfer and fluid analysis software FloEFD PRO12.1,one achieves the model and thermal simulation of 5 W LED heat cooling model.In addition,by applying the method of controlled variable,the radiator fin thickness,curvature and the effect laws of microstructure on the heat dissipation performance have further been explored,therefore enable the structure of radiator get fur-ther optimized.

  19. Experimental study on high-power LEDs integrated with micro heat pipe

    Science.gov (United States)

    LI, Cong-ming; Zhou, Chuan-peng; Luo, Yi; Hamidnia, Mohammad; Wang, Xiao-dong; You, Bo

    2016-01-01

    Micro heat pipe (MHP) is applied to implement the efficient heat transfer of light emitting diode (LED) device. The fabrication of MHP is based on micro-electro-mechanical-system (MEMS) technique, 15 micro grooves were etched on one side of silicon (Si) substrate, which was then packaged with aluminum heat sink to form an MHP. On the other side of Si substrate, three LED chips were fixed by die bonding. Then experiments were performed to study the thermal performance of this LED device. The results show that the LED device with higher filling ratio is better when the input power is 1.0 W; with the increase of input power, the optimum filling ratio changes from 30% to 48%, and the time reaching stable state is reduced; when the input power is equal to 2.5 W, only the LED device with filling ratio of 48% can work normally. So integrating MHP into high-power LED device can implement the effective control of junction temperature.

  20. Prognostics-based qualification of high-power white LEDs using Lévy process approach

    Science.gov (United States)

    Yung, Kam-Chuen; Sun, Bo; Jiang, Xiaopeng

    2017-01-01

    Due to their versatility in a variety of applications and the growing market demand, high-power white light-emitting diodes (LEDs) have attracted considerable attention. Reliability qualification testing is an essential part of the product development process to ensure the reliability of a new LED product before its release. However, the widely used IES-TM-21 method does not provide comprehensive reliability information. For more accurate and effective qualification, this paper presents a novel method based on prognostics techniques. Prognostics is an engineering technology predicting the future reliability or determining the remaining useful lifetime (RUL) of a product by assessing the extent of deviation or degradation from its expected normal operating conditions. A Lévy subordinator of a mixed Gamma and compound Poisson process is used to describe the actual degradation process of LEDs characterized by random sporadic small jumps of degradation degree, and the reliability function is derived for qualification with different distribution forms of jump sizes. The IES LM-80 test results reported by different LED vendors are used to develop and validate the qualification methodology. This study will be helpful for LED manufacturers to reduce the total test time and cost required to qualify the reliability of an LED product.

  1. Analysis of heat transfer of loop heat pipe used to cool high power LED

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A novel loop heat pipe(LHP)cooling device for high power LED is developed.The thermal capabilities, including startup performance,temperature uniformity and thermal resistance of the loop heat pipe under different heat loads and incline angles have been investigated experimentally.The obtained results indicate that the thermal resistance of the heat pipe heat sink is in the range of 0.19―3.1 K/W,the temperature uniformity in the evaporator is controlled within 1.5℃,and the junction temperature of high power LED can be controlled steadily under 100℃for a heat load of 100 W.

  2. Emotional arousal enhances word repetition priming

    OpenAIRE

    Thomas, Laura A.; LaBar, Kevin S.

    2005-01-01

    Three experiments were conducted to determine if emotional content increases repetition priming magnitude. In the study phase of Experiment 1, participants rated high-arousing negative (taboo) words and neutral words for concreteness. In the test phase, they made lexical decision judgements for the studied words intermixed with novel words (half taboo, half neutral) and pseudowords. In Experiment 2, low-arousing negative (LAN) words were substituted for the taboo words, and in Experiment 3 al...

  3. A combination of high stress-induced tense and energetic arousal compensates for impairing effects of stress on memory retrieval in men.

    Science.gov (United States)

    Boehringer, Andreas; Schwabe, Lars; Schachinger, Hartmut

    2010-09-01

    Stress can both impair and enhance memory retrieval. Glucocorticoids mediate impairing effects of stress on memory retrieval. Little is known, however, about factors that facilitate post-stress memory performance. Here, we asked whether stress-induced arousal mediates facilitative stress effects on memory retrieval. Two arousal dimensions were separated: tense arousal, which is characterized by feelings ranging from tension and anxiety to calmness and quietness, and energetic arousal, which is associated with feelings ranging from energy and vigor to states of fatigue and tiredness. Fifty-one men (mean age +/- SEM: 24.57 +/- 0.61 years) learned emotional and neutral words. Memory for these words was tested 165 min later, after participants were exposed to a psychosocial stress or a non-arousing control condition. Changes in heart rate, self-reported (energetic and tense) arousal, and saliva cortisol in response to the stress/control condition were measured. Overall, stress impaired memory retrieval. However, stressed participants with large increases in both tense and energetic arousal performed comparably to controls. Neither salivary cortisol level nor autonomic arousal predicted memory performance after controlling for changes in energetic and tense arousal. The present data indicate that stress-induced concurrent changes in tense and energetic arousal can compensate for impairing effects of stress on memory retrieval. This finding could help to explain some of the discrepancies in the literature on stress and memory.

  4. Very High Frequency Resonant DC/DC Converters for LED Lighting

    DEFF Research Database (Denmark)

    Madsen, Mickey Pierre; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    This paper presents a very high frequency DC/DC converter for LED lighting. Several resonant topologies are compared and their usability discussed. At the end the resonant SEPIC converter is chosen based on the achievable power density and total bill of material. Simulations of a 51 MHz converter...

  5. Hair cortisone level is associated with PTSD׳s dysphoric arousal symptoms in highly traumatized Chinese females.

    Science.gov (United States)

    Wang, Weiwen; Deng, Huihua; Wang, Li; Cao, Chengqi; Xu, Hang; Zhang, Jianxin

    2015-08-15

    Cortisone has been proposed as a useful additional biomarker for stress research. However, only very limited studies has investigated alterations of cortisone levels in stress-related mental disorder such as PTSD. The present study investigated the associations between PTSD symptomatology and hair cortisone levels which can reflect cumulative cortisone secretion over prolonged periods of time and is more robust to the influence of situational confounding. Participants included 201 females who experienced 2008 Wenchuan earthquake and lost their children during the disaster. PTSD symptoms were assessed with the PTSD Checklist (PCL), and depression symptoms with the Center for epidemiological studies depression scale (CES-D). Hair cortisone levels were quantified by liquid chromatography tandem mass spectrometer. The results indicated that although hair cortisone secretion could not distinguish traumatized individuals with and without PTSD, it was uniquely linked to dysphoric arousal symptoms, a key aspect of the complex PTSD phenotype A sample of females exposed to specific traumatic events was used, and PTSD was assessed using a self-reported measure. The findings provide preliminary evidence supporting the critical role of long-term cortisone changes in the development and maintenance of PTSD symptoms, and add to extant knowledge on the neuroendocrinological underpinnings of posttraumatic psychopathology. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Design and implementation of a high dimming ratio LED drive controller

    Institute of Scientific and Technical Information of China (English)

    徐孝如; 吴晓波; 赵梦恋; 严晓浪

    2009-01-01

    This paper presents a high dimming ratio light emitting diode (LED) drive controller chip with digital mode dimming (DMD). The chip is composed of a boost power converter and a dimming control block. A novel constant on time (COT) control strategy is proposed for boost converter to achieve high dimming ratio. In addition, a fast enough load transient response of the converter power stage ensures its high dimming ratio. The COT control circuit operates mainly based on two current-capacitor timers and a finite state machine (FSM). The LED drive con-troller chip is designed and fabricated in 1.5μm bipolar CMOS-DMOS (BCD) process with a die area of 1.31 × 1.43 mm2. Experimental results show that the proposed LED drive system works well. And, as expected, the minimum LED dimming on time of 1.0μs and the corresponding dimming ratio of 1000 : 1 at 1 kHz dimming frequency are successfully achieved.

  7. Thermal performance of direct illumination high-power LED backlight units with different assembling structures

    Science.gov (United States)

    Wang, Yiwei; Cen, Jiwen; Cao, Wenjiong; Jiang, Fangming

    2016-10-01

    This work presents a detailed study about the heat dissipation performance of direct illumination high-power light emitting diode (LED) backlight units with two different assembling structures, one of which is traditional and the other is new. The traditional structure, referred to by structure-1, consists of multiple LEDs being directly welded to the printed circuit board (PCB), where the PCB is used as a physical support, an electrical connector and also as a heat dissipation medium. The new structure, referred to by structure-2, places the LEDs directly on the cooling boss; in this case the PCB plays mainly the role of an electrical connector. Thermal characteristics related to the two backlight units are analyzed in terms of thermal resistance network, numerically simulated and experimentally tested. The obtained results by different methods accord with each other reasonably well and all indicate that both structures can meet the requirements of heat dissipation for backlight units at an ambient temperature of 30 °C. Among the two structures, the LED junction temperature of structure-1 backlight unit is 7-8 °C higher and the temperature distribution in the back plane of the backlight unit is also more uniform.

  8. The improvement of photocatalytic processes: Design of a photoreactor using high-power LEDs

    Directory of Open Access Journals (Sweden)

    Marzieh Khademalrasool

    2016-09-01

    Full Text Available This paper is an attempt to survey the benefits of a well-designed photoreactor containing just 6 ultraviolet (UV high power light emitting diodes (HPLEDs; the power and wavelength of each UV HPLED are 1 W and 365 nm, respectively, the latter being an efficient source for photocatalytic studies. Although the experiment with the 365-nm LEDs is reported here, other LEDs were predicted for conducting similar experiments including green photocatalytic ones. We installed diodes with respect to the luminescence intensity distribution curves (LIDCs or intensity patterns. Then, in order to compare the efficiency of the UV-HPLEDs of the HP-LED photoreactor (HPLED-PhR with that of traditional UV lamps which are extensively used in photocatalytic processes, a set of UV HPLEDs was designed and made up. Next, the performance of HPLED-PhR was compared with that of a traditional fluorescent lamp photoreactor (FL-PhR. As a typical photocatalytic experiment, Zinc Oxide (ZnO nanoparticles were synthesized via co-precipitation method and used as photocatalyst for purification of water polluted with the reactive blue dye (RB, under UV irradiation in two photoreactors. The results showed that the rate of photocatalytic reaction under the UV-LEDs was two times greater than the rate under the traditional fluorescent UV lamps, while both electrical power consumption and manufacturing cost of the HPLED-PhR were less than a quarter of them for the FL-PhR.

  9. Analysis of junction temperatures in high-power GaN-based LEDs

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We presented the analysis of the incomplete conduction in bonding medium in high power GaN-based light-emitting diode (LED) packages. A numerical study was carried out with parametric model to understand the junction temperature variation due to bonding medium defects. Transient thermal measurement was performed to evaluate LED’s junction temperature. Thermal resistance from chip to lead frame was 20 K/W in our sample LED. It was suggested that only 60% of the surface area of the bonding medium was involved in the thermal conduction. This result was also supported by the SEM image. Blocking of thermal path induced by ineffective area of the bonding medium was regarded as a factor of its thermal resistance. Thus, the effective area of the bonding medium should be included in the FEM model and considered as another important factor in high power LED’s thermal management.

  10. Reflective Optics Design for an LED High Beam Headlamp of Motorbikes

    Directory of Open Access Journals (Sweden)

    Peng Ge

    2015-01-01

    Full Text Available We propose a reflective optics design for an LED motorbike high beam lamp. We set the measuring screen as an elliptical zone and divide it into many small lattices and divide the spatial angle of the LED source into many parts and make relationships between them. According to the conservation law of energy and the Snell’s law, the reflector is generated by freeform optics design method. Then the optical system is simulated by Monte Carlo method using ASAP software. Light pattern of simulation could meet the standard. The high beam headlamp is finally fabricated and assembled into a physical object. Experiment results can fully comply with United Nations Economic Commission for Europe (ECE vehicle regulations R113 revision 2 (Class C.

  11. Highly efficient and reliable high power LEDs with patterned sapphire substrate and strip-shaped distributed current blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shengjun [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Yuan, Shu; Liu, Yingce [Quantum Wafer Inc., Foshan 528251 (China); Guo, L. Jay [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109 (United States); Liu, Sheng, E-mail: victor_liu63@126.com [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Ding, Han [State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-11-15

    Graphical abstract: - Highlights: • TEM is used to characterize threading dislocation existing in GaN epitaxial layer. • Effect of threading dislocation on optical and electrical of LEDs is discussed. • Strip-shaped SiO{sub 2} DCBL is designed to improve current spreading performance of LEDs. - Abstract: We demonstrated that the improvement in optical and electrical performance of high power LEDs was achieved using cone-shaped patterned sapphire substrate (PSS) and strip-shaped SiO{sub 2} distributed current blocking layer (DCBL). We found through transmission electron microscopy (TEM) observation that densities of both the screw dislocation and edge dislocation existing in GaN epitaxial layer grown on PSS were much less than that of GaN epitaxial layer grown on flat sapphire substrate (FSS). Compared to LED grown on FSS, LED grown on PSS showed higher sub-threshold forward-bias voltage and lower reverse leakage current, resulting in an enhancement in device reliability. We also designed a strip-shaped SiO{sub 2} DCBL beneath a strip-shaped p-electrode, which prevents the current from being concentrated on regions immediately adjacent the strip-shaped p-electrode, thereby facilitating uniform current spreading into the active region. By implementing strip-shaped SiO{sub 2} DCBL, light output power of high power PSS-LED chip could be further increased by 13%.

  12. High-Power Warm-White Hybrid LED Package for Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Soer, Wouter

    2013-09-19

    In this project, an integrated warm-white hybrid light engine was developed. The hybrid approach involves combining phosphor-converted off-white InGaN LEDs and direct-emitting red AlInGaP LEDs in a single light engine to achieve high efficacy together with high color rendering index. We developed and integrated technology improvements in InGaN and AlInGaP die technology, phosphor technology, package architecture and encapsulation, to realize a hybrid warm-white LED package with an efficacy of 140 lm/W at a correlated color temperature of 3000K and a color rendering index of 90, measured under representative operating conditions. This efficacy is 26% higher than the best warm-white LEDs of similar specification that are commercially available at the end of the project. Since the InGaN- and AlInGaP-based LEDs used in the hybrid engine show different behavior as a function of current and temperature, a control system needs to be in place to ensure a stable color point over all operating conditions. In this project, we developed an electronic control circuit that is fully integrated into the light engine in such a way that the module can simply be driven by a conventional single-channel driver. The integrated control circuit uses a switch-mode boost converter topology to control the LED drive currents based on the temperature and the input current of the light engine. A color control performance of 5 SDCM was demonstrated, and improvement to 3 SDCM is considered well within reach. The combination of high efficacy and ease of integration with existing single-channel drivers is expected to facilitate the adoption of the hybrid technology and accelerate the energy savings associated with solid-state lighting. In the product commercialization plan, downlights and indirect-lit troffers have been selected as the first target applications for this product concept. Fully functional integrated prototypes have been developed for both applications, and the business case

  13. Degradation of phosphor-in-glass encapsulants with various phosphor types for high power LEDs

    Science.gov (United States)

    Iqbal, Fauzia; Kim, Sunil; Kim, Hyungsun

    2017-10-01

    In order to replace conventional silicone-based phosphor light emitting diodes (LEDs), inorganic color converters with high thermal stabilities and transparencies, i.e., phosphors-in-glass (PiGs), have been investigated as encapsulants for high-power LEDs. In this paper, the effect of various types of phosphors, i.e., LuAG (green, Lu3Al5O12:Ce3+), silicate (yellow, Sr2SiO4:Eu2+), CASN (red, CaAlSiN3:Eu2+), and oxynitride (yellow, (Sr,Ba) Si2O2N2:Eu2+), on the reliability/degradation of the remote PiG encapsulants is explored for high power LEDs. For this purpose, a glass composition (SiO2-B2O3-ZnO-Na2O) was separately mixed with each type of phosphor and then sintered at appropriate temperatures to make the corresponding PiG. The reliabilities of the formed PiGs were evaluated by standard accelerated-aging tests (85 °C/85% RH) for 1000 h. Luminosity losses and shifts in the Commission Internationale de l'Eclairage (CIE) coordinates of the PiGs were measured before and after aging. Thermal, and moisture-induced quenching behavior was also analyzed. The surface of PiGs with different phosphors degraded differently, possibly because of structural incompatibilities between the glass matrix and phosphor type. Determining the compatibility of the glass composition with the type of phosphor used is therefore important in order to ensure the long-term stabilities of encapsulants for use in commercial LEDs.

  14. High dynamic grayscale lithography with an LED-based micro-image stepper

    Science.gov (United States)

    Eckstein, Hans-Christoph; Zeitner, Uwe D.; Leitel, Robert; Stumpf, Marko; Schleicher, Philipp; Bräuer, Andreas; Tünnermann, Andreas

    2016-03-01

    We developed a novel LED projection based direct write grayscale lithography system for the generation of optical surface profiles such as micro-lenses, diffractive elements, diffusors, and micro freeforms. The image formation is realized by a LCoS micro-display which is illuminated by a 405 nm UV High Power LED. The image on the display can be demagnified from factors 5x to 100x with an exchangeable lens. By controlling exposure time and LED power, the presented technique enables a highly dynamic dosage control for the exposure of h-line sensitive photo resist. In addition, the LCoS micro-display allows for an intensity control within the micro-image which is particularly advantageous to eliminate surface profile errors from stitching and limited homogeneity from LED illumination. Together with an accurate calibration of the resist response this leads to a superior low surface error of realized profiles below area of 500 × 500 mm2 with a positioning accuracy of 80°. Another benefit of the approach is a patterning speed up to 100 cm2/h, which allows fabricating large-scale optics and microstructures in an acceptable time. We present the setup and show examples of micro-structures to demonstrate the performance of the system, namely a refractive freeform array, where the RMS surface deviation does not exceed 0.2% of the total structure depth of 75 μm. Furthermore, we show that this exposure tool is suitable to generate diffractive optical elements as well as freeform optics and arrays with a high aspect ratio and structure depth showing a superior optical performance. Lastly we demonstrate a multi-level diffraction grating on a curved substrate.

  15. High-performance epoxy casting resins for SMD-LED packaging

    Science.gov (United States)

    Bogner, Georg; Debray, Alexandra; Hoehn, Klaus

    2000-04-01

    In order to come up with high volume SMD-LED production encompassing 1.9 billion devices for current fiscal year we did basic exploratory work to establish structure-processing- property relations for robust epoxy casting resin packages with identical ppm level of one. Bisphenol A-based epoxy casting resins (DGEBA) with acidic ester modified Hexahydrophthalic anhydride (HHPA) hardeners using strictly controlled high-grade raw materials were formulated and thermally transferred to highly transparent polyester networks. For 1 mm thick samples transparency in the 400 to 800 nm region is above 90%. Thermal aging tests for 6 weeks at 120 degrees Celsius reveal only slight discoloration with a color distance of 2. To avoid significant light losses within the LED operating life of 100,000 hrs stress on mechanically sensitive light-emitting chips was reduced by matching glass transition temperature Tg and E-modulus to 115 degrees Celsius and 2,800 MPa, respectively. Total chloride content below 1,000 ppm imply low corrosion potential. Further, resin composition, epoxy-hardener mixing ratio as well as curing profile were adapted to materialize fast curing for demand quantities while introducing effective low stress moieties in the final structure. Low internal stress, superior thermal shock and crack resistance were derived from supreme fracture toughness: KIC and GIC values were 1.350 MPam1/2 and 560 J/m2. With favorable water absorption behavior LED-packages withstand all soldering processes including TTW (through the wave) soldering. Thus, SMD-LEDs fulfill electronic industry standard JEDEC LEVEL 2.

  16. Numerical simulation and experimental research of the integrated high-power LED radiator

    Science.gov (United States)

    Xiang, J. H.; Zhang, C. L.; Gan, Z. J.; Zhou, C.; Chen, C. G.; Chen, S.

    2017-01-01

    The thermal management has become an urgent problem to be solved with the increasing power and the improving integration of the LED (light emitting diode) chip. In order to eliminate the contact resistance of the radiator, this paper presented an integrated high-power LED radiator based on phase-change heat transfer, which realized the seamless connection between the vapor chamber and the cooling fins. The radiator was optimized by combining the numerical simulation and the experimental research. The effects of the chamber diameter and the parameters of fin on the heat dissipation performance were analyzed. The numerical simulation results were compared with the measured values by experiment. The results showed that the fin thickness, the fin number, the fin height and the chamber diameter were the factors which affected the performance of radiator from primary to secondary.

  17. Financial Anxiety, Physiological Arousal, and Planning Intention

    Directory of Open Access Journals (Sweden)

    John Grable

    2014-12-01

    Full Text Available Results from this exploratory clinical study indicate that financial anxiety—holding an unhealthy attitude about one’s financial situation—and physiological arousal—the physical precursor to behavior—play important roles in shaping consumer intention to engage in future financial planning activity. Findings suggest that those who are most likely to engage the services of a financial adviser exhibit low levels of financial anxiety and moderate to high levels of physiological arousal. The least likely to seek the help of a financial adviser are those who exhibit high financial anxiety and low physiological arousal. Results support findings documented in the literature that high anxiety levels often lead to a form of self-imposed helplessness. In order to move those experiencing financial anxiety towards financial solutions, financial advisers ought to take steps to simultaneously reduce financial stressors and stimulate arousal as a way to promote behavioral change and help seeking.

  18. High-output LED-based light engine for profile lighting fixtures with high color uniformity using freeform reflectors.

    Science.gov (United States)

    Gadegaard, Jesper; Jensen, Thøger Kari; Jørgensen, Dennis Thykjær; Kristensen, Peter Kjær; Søndergaard, Thomas; Pedersen, Thomas Garm; Pedersen, Kjeld

    2016-02-20

    In the stage lighting and entertainment market, light engines (LEs) for lighting fixtures are often based on high-intensity discharge (HID) bulbs. Switching to LED-based light engines gives possibilities for fast switching, additive color mixing, a longer lifetime, and potentially, more energy-efficient systems. The lumen output of a single LED is still not sufficient to replace an HID source in high-output profile fixtures, but combining multiple LEDs can create an LE with a similar output, but with added complexity. This paper presents the results of modeling and testing such a light engine. Custom ray-tracing software was used to design a high-output red, green and blue LED-based light engine with twelve CBT-90 LEDs using a dual-reflector principle. The simulated optical system efficiency was 0.626 with a perfect (R=1) reflector coating for light delivered on a target surface through the entire optical system. A profile lighting fixture prototype was created, and provided an output of 6744 lumen and an efficiency of 0.412. The lower efficiency was mainly due to a non-optimal reflector coating, and the optimized design is expected to reach a significantly higher efficiency.

  19. Low-noise moisture meter with high-speed LED techniques

    Science.gov (United States)

    Aikio, Rami; Lindström, Hannu; Suopajärvi, Pekka; Malinen, Jouko; Mäntylä, Markku

    2010-04-01

    Near infrared (NIR) spectroscopy can provide inexpensive, rapid and contact-free chemical content measurements for on-line, hand-held and laboratory applications. Traditionally multiwavelength NIR analyzers are based on incandescent lamp light sources with rotating filter wheels, even though designs relying on lamp technology and moving parts mean larger size, require frequent maintenance and eventually limit measurement speed of the system. Today, optical power and available wavelength range of LEDs enable their use in chemical content analyzers. In this publication, a paper moisture meter with high speed LED techniques is presented. A prototype developed at VTT utilizes an extended InGaAs detector to measure diffuse reflection at four NIR wavelengths ranging from 1.2 to 2.1 μm. Source LED currents are amplitude modulated with fixed sinusoidal frequencies. Optical signals at each wavelength are demodulated from the detector signal using real-time digital lock-in detection method on an FPGA. Moisture content is calculated and displayed on the embedded platform. The design allows very high speed operation, where the result is updated every 1 ms. Performance of the prototype system was studied by measuring a set of known sealed paper samples. Paper moisture measurement accuracy was 0.14, repeatability 0.01 and 2σ noise 0.04 moisture percent. Laboratory tests showed that channel crosstalk after detection is below background noise level. The measured signal-to-noise ratios per channel were 70 - 85 dB when all LEDs were on. The overall performance equals the level of incandescent lamp based on-line moisture meters currently in use in paper mill and process automation. The developed system forms a good basis also for other content measurements.

  20. Cooling of High-Power LED Lamp Using a Commercial Paraffin Wax

    Science.gov (United States)

    Zmywaczyk, J.; Zbińkowski, P.; Smogór, H.; Olejnik, A.; Koniorczyk, P.

    2017-03-01

    Commercial paraffin wax used by Bolsius Nederland B.V. for manufacturing various kinds of candles was applied as a phase-change material (PCM) for cooling a 28 W high-power light emitting diode (LED) panel during its operation. The main problem arising during operation of an LED is thermal management. According to the manufacturer's datasheet specifications (BioSolution Ltd. www.biosolution.pl, the operating temperature range for the LED street lamp UL28W is (-30 {°}C) to (+40 {°}C). The object of the present study was an LED panel containing 28 pieces of high-power 1W LEDs connected in series (4 LEDs in each of the 7 rows) mounted on an aluminum plate of dimensions 80 mm by 135 mm. The tested aluminum plate was placed in a block made of aluminum with a hollow compartment containing Bolsius paraffin wax of density 914 kg\\cdot m^{-3} at room temperature. Temperatures were recorded using K-type thermocouples at selected locations of the tested LED panel for several values of the power supplied to it, while utilizing PCM and without it. As the manufacturer of Bolsius wax candles does not provide any data on the thermal properties of the material used, it was necessary to carry out micro-calorimetric research. Thermophysical properties of the paraffin wax such as the apparent specific heat, enthalpy of phase transition and temperature of phase change transition during heating and cooling were determined using the Netzsch DSC 214 Polyma. The Netzsch TG 209F3 Tarsus was used for TG/DTG measurements. DSC investigations revealed the following thermal transitions taking place during the first heating: solid-solid transition (onset 30.4 {°}C, peak at 40.9 {°}C), solid-liquid transition (onset 47.7 {°}C, peak at 54.9 {°}C, end at 58.3 {°}C), latent heat of energy storage 201 J\\cdot g^{-1}, apparent specific heat corresponding to peak at 41.5 {°}C (5.498 J\\cdot g^{-1}\\cdot K^{-1}). DTG investigations revealed that the decomposition of paraffin wax is a two

  1. Degradation Physics of High Power LEDs in Outdoor Environment and the Role of Phosphor in the degradation process.

    Science.gov (United States)

    Singh, Preetpal; Tan, Cher Ming

    2016-04-07

    A moisture- electrical - temperature (MET) test is proposed to evaluate the outdoor reliability of high power blue LEDs, with and without phosphor, and to understand the degradation physics of LEDs under the environment of combined humidity, temperature and electrical stresses. The blue LEDs with phosphor will be the high power white LEDs. Scanning acoustic microscopy is used to examine the resulted delamination during this test for the LEDs. The degradation mechanisms of blue LEDs (LEDs without phosphor) and white LEDs (LEDs with phosphor) are found to be different, under both the power on (i.e. with 350 mA through each LED) and power off (i.e. without current supply) conditions. Difference in the coefficient of thermal expansion between the molding part and the lens material as well as the heat generated by the phosphor layer are found to account for the major differences in the degradation mechanisms observed. The findings indicate that the proposed MET test is necessary for the LED industry in evaluating the reliability of LEDs under practical outdoor usage environment.

  2. On pleasure and thrill: the interplay between arousal and valence during visual word recognition.

    Science.gov (United States)

    Recio, Guillermo; Conrad, Markus; Hansen, Laura B; Jacobs, Arthur M

    2014-07-01

    We investigated the interplay between arousal and valence in the early processing of affective words. Event-related potentials (ERPs) were recorded while participants read words organized in an orthogonal design with the factors valence (positive, negative, neutral) and arousal (low, medium, high) in a lexical decision task. We observed faster reaction times for words of positive valence and for those of high arousal. Data from ERPs showed increased early posterior negativity (EPN) suggesting improved visual processing of these conditions. Valence effects appeared for medium and low arousal and were absent for high arousal. Arousal effects were obtained for neutral and negative words but were absent for positive words. These results suggest independent contributions of arousal and valence at early attentional stages of processing. Arousal effects preceded valence effects in the ERP data suggesting that arousal serves as an early alert system preparing a subsequent evaluation in terms of valence. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Emotion and Implicit Timing: The Arousal Effect

    Science.gov (United States)

    Droit-Volet, Sylvie; Berthon, Mickaël

    2017-01-01

    This study tested the effects of emotion on implicit time judgment. The participants did not receive any overt temporal instructions. They were simply trained to respond as quickly as possible after a response signal, which was separated from a warning signal by a reference temporal interval. In the testing phase, the inter-signal interval was shorter, equal or longer than the reference interval and was filled by emotional pictures (EP) of different arousal levels: high, moderate, and low. The results showed a U-shaped curve of reaction time plotted against the interval duration, indicating an implicit processing of time. However, this RT-curve was shifted toward the left, with a significantly lower peak time for the high-arousal than for the low-arousal EP. This emotional time distortion in an implicit timing task suggests an automatic effect of emotion on the internal clock rate. PMID:28261125

  4. Single-crystal phosphors for high-brightness white LEDs/LDs

    Science.gov (United States)

    Víllora, Encarnación G.; Arjoca, Stelian; Inomata, Daisuke; Shimamura, Kiyoshi

    2016-03-01

    White light-emitting diodes (wLEDs) are the new environmental friendly sources for general lighting purposes. For applications requiring a high-brightness, current wLEDs present overheating problems, which drastically decrease their emission efficiency, color quality and lifetime. This work gives an overview of the recent investigations on single-crystal phosphors (SCPs), which are proposed as novel alternative to conventional ceramic powder phosphors (CPPs). This totally new approach takes advantage of the superior properties of single-crystals in comparison with ceramic materials. SCPs exhibit an outstanding conversion efficiency and thermal stability up to 300°C. Furthermore, compared with encapsulated CPPs, SCPs possess a superior thermal conductivity, so that generated heat can be released efficiently. The conjunction of all these characteristics results in a low temperature rise of SCPs even under high blue irradiances, where conventional CPPs are overheated or even burned. Therefore, SCPs represent the ideal, long-demanded all-inorganic phosphors for high-brightness white light sources, especially those involving the use of high-density laser-diode beams.

  5. Growth of highly bright-white silica nanowires as diffusive reflection coating in LED lighting.

    Science.gov (United States)

    Xi, Shuang; Shi, Tielin; Zhang, Lei; Liu, Dan; Lai, Wuxing; Tang, Zirong

    2011-12-19

    Large quantities of silica nanowires were synthesized through thermal treatment of silicon wafer in the atmosphere of N(2)/H(2)(5%) under 1200 °C with Cu as catalyst. These nanowires grew to form a natural bright-white mat, which showed highly diffusive reflectivity over the UV-visible range, with more than 60% at the whole range and up to 88% at 350 nm. The utilization of silica nanowires in diffusive coating on the reflector cup of LED is demonstrated, which shows greatly improved light distribution comparing with the specular reflector cup. It is expected that these nanowires can be promising coating material for optoelectronic applications.

  6. Emergency positioning system accuracy with infrared LEDs in high-security facilities

    Science.gov (United States)

    Knoch, Sierra N.; Nelson, Charles; Walker, Owens

    2017-05-01

    Instantaneous personnel location presents a challenge in Department of Defense applications where high levels of security restrict real-time tracking of crew members. During emergency situations, command and control requires immediate accountability of all personnel. Current radio frequency (RF) based indoor positioning systems can be unsuitable due to RF leakage and electromagnetic interference with sensitively calibrated machinery on variable platforms like ships, submarines and high-security facilities. Infrared light provide a possible solution to this problem. This paper proposes and evaluates an indoor line-of-sight positioning system that is comprised of IR and high-sensitivity CMOS camera receivers. In this system the movement of the LEDs is captured by the camera, uploaded and analyzed; the highest point of power is located and plotted to create a blueprint of crewmember location. Results provided evaluate accuracy as a function of both wavelength and environmental conditions. Research will further evaluate the accuracy of the LED transmitter and CMOS camera receiver system. Transmissions in both the 780 and 850nm IR are analyzed.

  7. Improvement of electroluminescent property of blue LED coated with highly luminescent yellow-emitting phosphors

    Science.gov (United States)

    Jang, H. S.; Won, Y.-H.; Jeon, D. Y.

    2009-06-01

    White light-emitting diodes (WLEDs) were fabricated by combining InGaN-based blue light-emitting diodes (LEDs) with highly luminescent Tb3Al5O12:Ce3+ (TAG:Ce), Y3Al5O12:Ce3+ (YAG:Ce), and Sr3SiO5:Eu2+ (SS:Eu). The TAG:Ce-based WLED showed a color rendering index ( R a ) of 79 and a luminous efficiency ( η L ) of 34.1 lm/W at 20 mA. The YAG:Ce-based WLED and the SS:Eu-based WLED showed low R a values of 75 and 57 but high luminous efficiency values of 38.9 and 41.3 lm/W at 20 mA, respectively. When a mixture of YAG:Ce and SS:Eu was coated on a blue LED and the resultant WLED operated at 20 mA, the WLED showed a highly bright white light similar to daylight ( η L =40.9 lm/W, color temperature T c =5,716 K, and R a =76). Moreover, the WLED showed stable color coordinates against a considerable variation of applied current.

  8. In vivo functional connectome of human brainstem nuclei of the ascending arousal, autonomic and motor systems by high spatial resolution 7 Tesla fMRI

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Eichner, Cornelius; Polimeni, Jonathan R.; Setsompop, Kawin; Brown, Emery N.; Hamalainen, Matti S.; Rosen, Bruce R.; Wald, Lawrence L.

    2016-01-01

    Object To map the in vivo human functional connectivity of several brainstem nuclei with the rest of the brain by using seed-based correlation of ultra-high magnetic field functional magnetic resonance imaging (fMRI) data. Materials and Methods We used the recently developed template of 11 brainstem nuclei derived from multi-contrast structural MRI at 7 Tesla as seed regions to determine their connectivity to the rest of the brain. To achieve this, we utilized the increased contrast-to-noise ratio of 7 Tesla fMRI compared to 3 Tesla and the time efficient simultaneous multi-slice imaging to cover the brain with high spatial resolution (1.1 mm-isotropic nominal resolution) while maintaining a short repetition time (2.5 s). Results The delineated Pearson’s correlation-based functional connectivity diagrams (connectomes) of 11 brainstem nuclei of the ascending arousal, motor and autonomic systems from 12 controls are presented and discussed in the context of existing histology and animal work. Conclusion Considering that the investigated brainstem nuclei play a crucial role in several vital functions, the delineated preliminary connectomes might prove useful for future in vivo research and clinical studies of human brainstem function and pathology, including disorders of consciousness, sleep disorders, autonomic disorders, Parkinson’s disease and other motor disorders. PMID:27126248

  9. In vivo functional connectome of human brainstem nuclei of the ascending arousal, autonomic, and motor systems by high spatial resolution 7-Tesla fMRI.

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Eichner, Cornelius; Polimeni, Jonathan R; Setsompop, Kawin; Brown, Emery N; Hämäläinen, Matti S; Rosen, Bruce R; Wald, Lawrence L

    2016-06-01

    Our aim was to map the in vivo human functional connectivity of several brainstem nuclei with the rest of the brain by using seed-based correlation of ultra-high magnetic field functional magnetic resonance imaging (fMRI) data. We used the recently developed template of 11 brainstem nuclei derived from multi-contrast structural MRI at 7 Tesla as seed regions to determine their connectivity to the rest of the brain. To achieve this, we used the increased contrast-to-noise ratio of 7-Tesla fMRI compared with 3 Tesla and time-efficient simultaneous multi-slice imaging to cover the brain with high spatial resolution (1.1-mm isotropic nominal resolution) while maintaining a short repetition time (2.5 s). The delineated Pearson's correlation-based functional connectivity diagrams (connectomes) of 11 brainstem nuclei of the ascending arousal, motor, and autonomic systems from 12 controls are presented and discussed in the context of existing histology and animal work. Considering that the investigated brainstem nuclei play a crucial role in several vital functions, the delineated preliminary connectomes might prove useful for future in vivo research and clinical studies of human brainstem function and pathology, including disorders of consciousness, sleep disorders, autonomic disorders, Parkinson's disease, and other motor disorders.

  10. The role of insomnia, pre-sleep arousal and psychopathology symptoms in daytime impairment in adolescents with high-functioning autism spectrum disorder.

    Science.gov (United States)

    Richdale, Amanda L; Baker, Emma; Short, Michelle; Gradisar, Michael

    2014-09-01

    Sleep disturbance and psychopathology are common during adolescence and are highly prevalent in individuals diagnosed with autism spectrum disorder (ASD). The aim of this study was to investigate relationships between sleep disturbance, psychopathology symptoms, and daytime functioning in adolescents with high-functioning autism spectrum disorder (HFASD) compared to typically developing (TD) adolescents. Twenty-seven adolescents with HFASD and 27 age- and sex-matched TD adolescents completed questionnaires related to sleep, psychopathology and daytime functioning. Participants also completed a 7-day sleep/wake diary. A subsample of HFASD adolescents (55%) and all the TD adolescents wore an actigraphy monitor concurrently with the sleep diary. Adolescents with HFASD had significantly higher scores for depressed mood, anxiety and pre-sleep arousal compared with TD adolescents and poorer daytime functioning. There were more significant correlations between sleep variables and psychopathology variables, and sleep variables and daytime functioning, in the HFASD group than in the TD group. Standard regression found that sleep variables significantly accounted for 57% of the variance in daytime functioning symptoms of insufficient sleep in the HFASD group, while psychopathology variables accounted for 63% of the variance in daytime functioning. Both sleep disturbance and psychopathology are more prevalent in adolescents with HFASD and are major contributors to poor daytime functioning in these individuals. Copyright © 2014. Published by Elsevier B.V.

  11. Experimental and numerical study on a micro jet cooling solution for high power LEDs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An active cooling solution based on close-looped micro impinging jet is proposed for high power light emitting diodes (LEDs). In this system, a micro pump is utilized to enable the fluid circulation, impinging jet is used for heat exchange between LED chips and the present system. To check the feasibility of the present cooling system, the preliminary experiments are conducted without the intention of parameter opti-mization on micro jet device and other system components. The experiment results demonstrate that the present cooling system can achieve good cooling effect. For a 16.4 W input power, the surface temperature of 2 by 2 LED array is just 44.2℃ after 10 min operation, much lower than 112.2℃, which is measured without any active cool-ing techniques at the same input power. Experimental results also show that increase in the flow rate of micro pump will greatly enhance the heat transfer efficiency, how-ever, it will increase power consumption. Therefore, it should have a trade-off be-tween the flow rate and the power consumption. To find a suitable numerical model for next step parameter optimization, numerical simulation on the above experiment system is also conducted in this paper. The comparison between numerical and ex-periment results is presented. For two by two chip array, when the input power is 4 W, the surface average temperature achieved by a steady numerical simulation is 34℃, which is close to the value of 32.8℃ obtained by surface experiment test. The simu-lation results also demonstrate that the micro jet device in the present cooling sys-tem needs parameter optimization.

  12. Experimental and numerical study on a micro jet cooling solution for high power LEDs

    Institute of Scientific and Technical Information of China (English)

    LUO XiaoBing; LIU Sheng; JIANG XiaoPing; CHENG Ting

    2007-01-01

    An active cooling solution based on close-looped micro impinging jet is proposed for high power light emitting diodes (LEDs). In this system, a micro pump is utilized to enable the fluid circulation, impinging jet is used for heat exchange between LED chips and the present system. To check the feasibility of the present cooling system, the preliminary experiments are conducted without the intention of parameter optimization on micro jet device and other system components. The experiment results demonstrate that the present cooling system can achieve good cooling effect. For a 16.4 W input power, the surface temperature of 2 by 2 LED array is just 44.2℃ after 10 min operation, much lower than 112.2℃, which is measured without any active cooling techniques at the same input power. Experimental results also show that increase in the flow rate of micro pump will greatly enhance the heat transfer efficiency, however, it will increase power consumption. Therefore, it should have a trade-off between the flow rate and the power consumption. To find a suitable numerical model for next step parameter optimization, numerical simulation on the above experiment system is also conducted in this paper. The comparison between numerical and experiment results is presented. For two by two chip array, when the input power is 4 W, the surface average temperature achieved by a steady numerical simulation is 34℃, which is close to the value of 32.8℃ obtained by surface experiment test. The simulation results also demonstrate that the micro jet device in the present cooling system needs parameter optimization.

  13. Resting physiological arousal is associated with the experience of music-induced chills.

    Science.gov (United States)

    Mori, Kazuma; Iwanaga, Makoto

    2014-08-01

    In the study of emotion and autonomic nervous system functioning, resting physiological arousal is usually considered a negative characteristic. The present study examined the relationship between resting physiological arousal and positive emotional experience linked to psychophysiological arousal. We assessed resting physiological arousal using markers as high skin conductance level and low respiratory sinus arrhythmia, measured just before participants listened to their favorite music. Participants reported the sensation of chills (goose bumps, shivers) by pressing a mouse button while listening. The results indicated that individuals with resting physiological arousal frequently experience music-induced chills, which evoked unambiguous pleasurable feelings and an increase in skin conductance response. The current results, and the previously demonstrated relationship between resting physiological arousal and negative emotionality linked to psychophysiological arousal (e.g., anxiety, panic), suggest that resting physiological arousal may reflect sensitivity to psychophysiological arousal with both intense positive and negative emotions.

  14. Fabrication and property analysis of AIGalnP red light LED with high bright

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The LED with DBR and enhancing transmission film was grown by MOCVD. At 20 mA DC injection current, the LED peak wavelength was 623 nm, the light intensity was 200 mcd, and the output light power was 2.14 mW. The light intensity and output light power have been improved than traditional LED.

  15. Let's be skeptical about reconsolidation and emotional arousal in therapy.

    Science.gov (United States)

    Patihis, Lawrence

    2015-01-01

    Lane et al. imply hypotheses that are questionable: that emotional arousal is a cause of positive change and reconsolidation research can be applied to therapy to alter memory. Given the history of problematic attempts to incorporate memory distortion or high emotional arousal into therapeutic techniques, both of which heralded premature optimism and hubris, I urge open-minded skepticism.

  16. Application of Inkjet Printing in High-Density Pixelated RGB Quantum Dot-Hybrid LEDs

    KAUST Repository

    Haverinen, Hanna

    2012-05-23

    Recently, an intriguing solution to obtain better color purity has been to introduce inorganic emissive quantum dots (QDs) into an otherwise OLED structure. The emphasis of this chapter is to present a simple discussion of the first attempts to fabricate high-density, pixelated (quarter video graphics array (QVGA) format), monochromatic and RGB quantum dots light-emitting diodes (QDLEDs), where inkjet printing is used to deposit the light-emitting layer of QDs. It shows some of the factors that have to be considered in order to achieve the desired accuracy and printing quality. The successful operation of the RGB printed devices indicates the potential of the inkjet printing approach in the fabrication of full-color QDLEDs for display application. However, further optimization of print quality is still needed in order to eliminate the formation of pinholes, thus maximizing energy transfer from organic layers to the QDs and in turn increasing the performance of the devices. Controlled Vocabulary Terms: ink jet printing; LED displays; LED lamps; organic light emitting diodes; quantum dots

  17. Dicing of high-power white LEDs in heat sinks with the water jet-guided laser

    Science.gov (United States)

    Mai, Tuan Anh; Housh, Roy; Brulé, Arnaud; Richerzhagen, Bernold

    2007-02-01

    High-brightness LEDs are compound semiconductor devices and distinguish themselves from conventional LEDs by their exceptional luminosity. Today they are increasingly used as light sources, replacing conventional incandescent and fluorescent lamp technologies. HB LEDs are difficult to manufacture, as they must be grown by sophisticated epitaxial growth techniques such as MOCVD. They are packaged like power semiconductors, using surface mount technology and thermal pads. After having been successfully applied to GaN scribing for side-emitting LEDs, the Laser MicroJet (R) is used today for cutting heat sinks of HB white LEDs. Due to the high-emitted light power, the generated heat must be dissipated through a heat sink. Materials typically employed are metals with high heat conductivity, notably CuW and molybdenum. Applying the Laser MicroJet (R) the achieved cutting quality in these metals is outstanding - smooth edges, no contamination, no burrs, no heat damage, no warping - all this at high speed.

  18. Can Arousal Modulate Response Inhibition?

    Science.gov (United States)

    Weinbach, Noam; Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai

    2015-01-01

    The goal of the present study was to examine if and how arousal can modulate response inhibition. Two competing hypotheses can be drawn from previous literature. One holds that alerting cues that elevate arousal should result in an impulsive response and therefore impair response inhibition. The other suggests that alerting enhances processing of…

  19. Comparison of Bond Strength of Metal and Ceramic Brackets Bonded with Conventional and High-Power LED Light Curing Units

    Science.gov (United States)

    Chalipa, Javad; Jalali, Yasamin Farajzadeh; Gorjizadeh, Fatemeh; Baghaeian, Pedram; Hoseini, Mohammad Hashem

    2016-01-01

    Objectives: The aim of this study was to evaluate the effect of conventional and high-power light emitting diode (LED) light curing units on shear bond strength (SBS) of metal and ceramic brackets to tooth surface. Materials and Methods: Forty sound bovine maxillary central incisors were used for the study. The teeth were divided into four groups (n=10). Teeth surfaces were etched with 37% phosphoric acid for 20 seconds. After applying a uniform layer of adhesive primer on the etched enamel, composite was placed on the base of brackets. The samples were light cured according to the manufacturer’s instructions and thermocycled. The SBS was measured. The failure mode was scored using the adhesive remnant index (ARI). Results: The mean SBS of samples in groups A (high-power LED, metal bracket), B (high-power LED, ceramic bracket), C (conventional LED, metal bracket) and D (conventional LED, ceramic bracket) was 23.1±3.69, 10.7±2.06, 24.92±6.37 and 10.74±3.18MPa, respectively. The interaction effect of type of LED unit (high-power/conventional) and bracket type on SBS was not statistically significant (P=0.483). In general, type of LED unit did not affect SBS. Type of bracket significantly affected SBS (P<0.001). The ARI score was not significantly influenced by the interaction between the type of LED unit and bracket. Conclusions: The obtained SBS is the same for both bracket types by use of high-power and conventional LED light curing units. Regardless of the type of LED unit, SBS of ceramic brackets was significantly lower than that of metal brackets.

  20. Fundamental Studies and Development of III-N Visible LEDs for High-Power Solid-State Lighting Applications

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, Russell

    2012-02-29

    The goal of this program is to understand in a fundamental way the impact of strain, defects, polarization, and Stokes loss in relation to unique device structures upon the internal quantum efficiency (IQE) and efficiency droop (ED) of III-nitride (III-N) light-emitting diodes (LEDs) and to employ this understanding in the design and growth of high-efficiency LEDs capable of highly-reliable, high-current, high-power operation. This knowledge will be the basis for our advanced device epitaxial designs that lead to improved device performance. The primary approach we will employ is to exploit new scientific and engineering knowledge generated through the application of a set of unique advanced growth and characterization tools to develop new concepts in strain-, polarization-, and carrier dynamics-engineered and low-defect materials and device designs having reduced dislocations and improved carrier collection followed by efficient photon generation. We studied the effects of crystalline defect, polarizations, hole transport, electron-spillover, electron blocking layer, underlying layer below the multiplequantum- well active region, and developed high-efficiency and efficiency-droop-mitigated blue LEDs with a new LED epitaxial structures. We believe new LEDs developed in this program will make a breakthrough in the development of high-efficiency high-power visible III-N LEDs from violet to green spectral region.

  1. Commerical Transition to LEDs: A Pathway to High-Value Products

    Science.gov (United States)

    Stutte, Gary W.

    2015-01-01

    The use of light-emitting diodes (LEDs) to support plant growth is a radical departure from use of gas-discharge lamps, which were developed in mid-19th and widely adopted by the industry during the 20th century. Initial investigation by the National Aeronautics and Space Administration (NASA) in the late 1980s on the use of LEDs to grow plant in space is resulting in an industry-wide transition from gas discharge to solid-state lighting systems. This global transformation is given urgency by national policies to reduce energy consumption and being facilitated by ready access to information on LEDs. The combination of research, government policy, and information technology has resulted in an exponential increase in research into the use and application of LED technology in horticulture. Commercial horticulture has identified the opportunities provided by LEDs to optimize light spectra to promote growth, regulate morphology, increase nutrient content, and reduce operating costs. LED-light technology is enabling the development of innovative lighting systems, and is being incorporated into large-scale plant factories for the production of edible, ornamental, and medicinal plants. An overview of prevalence of readily accessible information on LEDs and implications for future adoption in horticulture is discussed.

  2. Arousal-Augmented Priming Effects: Rock Music Videos and Sex Object Schemas.

    Science.gov (United States)

    Hansen, Christine Hall; Krygowski, Walter

    1994-01-01

    Investigates effects of undergraduate students' physiological arousal induced by physical activity on schematic priming effects from music videos. Finds that in high-arousal conditions priming effects were more extreme and more closely resembled music video content than in low-arousal conditions. (SR)

  3. Copper Aluminum Nano Junction Normal Temperature Processes and Methods Applied to the LED High Heat Transfer Performance

    Directory of Open Access Journals (Sweden)

    Ming-Wen Wang

    2014-03-01

    Full Text Available High-power light-emitting diodes (LED have extremely broad applications. However, with the job requirements of high-brightness and high color temperature from light-emitting diodes, it must be followed to enlarge the operating current, thus heating up more rapidly. If its heat dissipation problem cannot be effectively solved, operation will be prone to bring about color shift, and it may even considerably shorten its life. Moreover, application value will therefore be greatly reduced. So in order to enhance the high-power LED luminous brightness and life to cope with the future development needs of high-power LED components, it is necessary to replace the use of conductive silver paste to stick thermally conductive Cu slug fixing grain and lead frame heat dissipation aluminum sheet. This is done by directly bonding thermally conductive Cu slug with pure aluminum, the formation of highly efficient direct heat conduction cooling structure. Therefore the topic points at the crux of the LED heat dissipation difficulty, puts forward of copper and aluminum bonding technology in the ordinary temperature and pressure, method to effectively improve thermal conductivity performance between LED die bond Cu slug and joining aluminum cooling module. This will ultimately make the LED's operation and applications perfect.

  4. Big Data Meets Physics Education Research: From MOOCs to University-Led High School Programs

    Science.gov (United States)

    Seaton, Daniel

    2017-01-01

    The Massive Open Online Course (MOOC) movement has catalyzed discussions of digital learning on campuses around the world and highlighted the increasingly large, complex datasets related to learning. Physics Education Research can and should play a key role in measuring outcomes of this most recent wave of digital education. In this talk, I will discuss big data and learning analytics through multiple modes of teaching and learning enabled by the open-source edX platform: open-online, flipped, and blended. Open-Online learning will be described through analysis of MOOC offerings from Harvard and MIT, where 2.5 million unique users have led to 9 million enrollments across nearly 300 courses. Flipped instruction will be discussed through an Advanced Placement program at Davidson College that empowers high school teachers to use AP aligned, MOOC content directly in their classrooms with only their students. Analysis of this program will be highlighted, including results from a pilot study showing a positive correlation between content usage and externally validated AP exam scores. Lastly, blended learning will be discussed through specific residential use cases at Davidson College and MIT, highlighting unique course models that blend open-online and residential experiences. My hope for this talk is that listeners will better understand the current wave of digital education and the opportunities it provides for data-driven teaching and learning.

  5. Arousal and exposure duration affect forward step initiation

    Directory of Open Access Journals (Sweden)

    Daniëlle eBouman

    2015-11-01

    Full Text Available Emotion influences parameters of goal-directed whole-body movements in several ways. For instance, previous research has shown that approaching (moving toward pleasant stimuli is easier compared to approaching unpleasant stimuli. However, some studies found that when emotional pictures are viewed for a longer time, approaching unpleasant stimuli may in fact be facilitated. The effect of viewing duration may modulate whole-body approach movement in previous research but this has not been investigated before. In the current study, participants initiated a step forward after viewing neutral, high-arousal pleasant and high-arousal unpleasant stimuli. The viewing duration of the stimuli was set to 7 different durations, varying from 100 to 4000ms. Valence and arousal scores were collected for all stimuli.The results indicate that both viewing duration and the arousal of the stimuli influence kinematic parameters in forward gait initiation. Specifically, longer viewing duration, compared to shorter viewing duration, (a diminished the step length and peak velocity in both neutral and emotional stimuli, (b increased reaction time in neutral stimuli and, (c decreased reaction time in pleasant and unpleasant stimuli. Strikingly, no differences were found between high-arousal pleasant and high-arousal unpleasant stimuli. In other words, the valence of the stimuli did not influence kinematic parameters of forward step initiation. In contrast, the arousal level (neutral: low; pleasant and unpleasant: high explained the variance found in the results. The kinematics of forward gait initiation seemed to be reflected in the subjective arousal scores, but not the valence scores. So it seems arousal affects forward gait initiation parameters more strongly than valence. In addition, longer viewing duration seemed to cause diminished alertness, affecting GI parameters. These results shed new light on the prevailing theoretical interpretations regarding approach

  6. The fabrication of a patterned ZnO nanorod array for high brightness LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyoungwon; Byeon, Kyeong-Jae; Yang, Ki-Yeon; Cho, Joong-Yeon; Lee, Heon, E-mail: heonlee@korea.ac.kr [Department of Materials Science and Engineering, Korea University, 5-1 Anam-Dong, Seongbuk-Ku, Seoul 136-701 (Korea, Republic of)

    2010-09-03

    In this study, a patterned ZnO nanorod array was formed on the ITO layer of GaN-based light-emitting diodes (LEDs), to increase the light extraction efficiency of the LED. The bi-layer imprinted resin pattern was used for selective growth of the ZnO nanorod array on the ITO layer. Compared to conventional LEDs grown on patterned sapphire substrate (PSS), the deposition of the blanket ZnO layer on the ITO layer increased the light extraction efficiency of the LED by about 10%. Further growth of the ZnO nanorod layer on the blanket ZnO layer increased the light extraction efficiency of the LED by about 23%. In the case that a patterned ZnO nanorod layer was formed on a blanket ZnO layer, the light extraction efficiency increased by about 34%. These enhancements of the device were caused by modulation of the refractive-index in ZnO layers and the surface roughening effects because of the unique design of the pattern, which was nanostructure-in-nanopattern, resulting in the formation of many escape cones on the LED surface.

  7. LED surgical lighting system with multiple free-form surfaces for highly sterile operating theater application.

    Science.gov (United States)

    Liu, Peng; Zhang, Yaqin; Zheng, Zhenrong; Li, Haifeng; Liu, Xu

    2014-06-01

    Although the ventilation system is widely employed in the operating theater, a strictly sterile surgical environment still cannot be ensured because of laminar disturbance, which is mainly caused by the surgical lighting system. Abandoning traditional products, we propose an LED surgical lighting system, which can alleviate the laminar disturbance and provide an appropriate lighting condition for surgery. It contains a certain amount of LED lens units, which are embedded in the ceiling and arranged around the air supply smallpox. The LED lens unit integrated with an LED light source and a free-form lens is required to produce a uniform circular illumination with a large tolerance to the change of lighting distance. To achieve such a dedicated lens, two free-form refractive surfaces, which are converted into two ordinary differential equations by the design method presented in this paper, are used to deflect the rays. The results show that the LED surgical lighting system can provide an excellent illumination environment for surgery, and, apparently, the laminar disturbance also can be relieved.

  8. Pupil-linked arousal determines variability in perceptual decision making

    National Research Council Canada - National Science Library

    Murphy, Peter R; Vandekerckhove, Joachim; Nieuwenhuis, Sander

    2014-01-01

    .... We measured pupil size, a highly sensitive index of arousal, while human subjects performed a motion-discrimination task, and decomposed task behavior into latent decision making parameters using...

  9. The influence of valence and arousal on reasoning: Affective priming in the semantic verification task

    Directory of Open Access Journals (Sweden)

    Orlić Ana

    2014-01-01

    Full Text Available The aim of the present study was to examine the effects of affective valence and arousal on the reasoning process. Reasoning was measured using a semantic verification task and the influence of valence and arousal was tracked using the affective priming paradigm. Primes were photographs varied on two dimensions - emotional valence (positive, neutral, negative and arousal (high, low. Forty-nine psychology students participated in the experiment. Results showed that reaction time needed for semantic verification was significantly faster for positive-high arousing in comparison to positive-low arousing condition and for neutral high arousing in comparison to neutral-low arousing condition, but there were no significant differences in negative low and high arousing conditions. Also, significant differences were found among all three valences in high arousing conditions and there were no such differences in low arousing conditions. These results reveal the importance of both arousal and valence in the research on the influence of emotions on the reasoning process. [Projekat Ministarstva nauke Republike Srbije, br. 179033

  10. Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles.

    Science.gov (United States)

    Cool, Simon; Pieters, Jan G; Mertens, Koen C; Mora, Sergio; Cointault, Frédéric; Dubois, Julien; van de Gucht, Tim; Vangeyte, Jürgen

    2015-11-12

    Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m² with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications.

  11. Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles

    Directory of Open Access Journals (Sweden)

    Simon Cool

    2015-11-01

    Full Text Available Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m2 with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications.

  12. Neural Representation of Subjective Sexual Arousal in Men and Women.

    Science.gov (United States)

    Parada, Mayte; Gérard, Marina; Larcher, Kevin; Dagher, Alain; Binik, Yitzchak M

    2016-10-01

    Studies investigating brain indices of sexual arousal have begun to elucidate the brain's role in processing subjective arousal; however, most research has focused on men, used discrete ratings of subjective arousal, and used stimuli too short to induce significant arousal in women. To examine brain regions modulated by changes in subjective sexual arousal (SSA) rating intensity in men and women. Two groups (20 men, 20 women) viewed movie clips (erotic or humorous) while continuously evaluating changes in their SSA using a Likert-like scale (0 = not aroused, 10 = most aroused) and answering discrete questions about liking the movies and wanting sexual stimulation. Brain activity was measured using functional magnetic resonance imaging. Blood oxygen level-dependent responses and continuous and discrete measurements of sexual arousal. Erotic movies induced significant SSA in men and women. No sex difference in mean SSA was found in response to the erotic movies on continuous or discrete measurements. Several brain regions were correlated with changes in SSA. Parametric modulation with rating intensity showed a specific group of regions within the parietal lobe that showed significant differences in activity among low, medium, and high SSA. Multiple regions were concordant with changes in SSA; however, a subset of regions in men and women was modulated by SSA intensity, a subset previously linked to attentional processes, monitoring of internal body representation, and processing of sensory information from the genitals. This study highlights that similar brain regions are activated during subjective assessment of sexual arousal in men and women. The data further highlight the fact that SSA is a complex phenomenon made up of multiple interoceptive and attentional processes. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  13. Food neophobia in humans: effects of manipulated arousal and individual differences in sensation seeking.

    Science.gov (United States)

    Pliner, P; Melo, N

    1997-02-01

    The study examined the effects of manipulated arousal and the trait of Sensation Seeking on willingness to taste novel foods (as assessed by means of a choice task). Arousal was manipulated by having subjects play an exciting, neutral, or boring video game. In line with predictions from optimal level of arousal theories, subjects chose more novel foods when manipulated arousal was low (vs. neutral) and fewer novel foods when manipulated arousal was high (vs. neutral). There was no main effect of individual differences in optimal level of arousal as assessed by the Sensation Seeking Scale; however, an interaction between the two independent variables revealed high-sensation seekers to try more novel foods than lows under conditions of low arousal.

  14. Semi-polar GaN materials technology for high IQE green LEDs.

    Energy Technology Data Exchange (ETDEWEB)

    Koleske, Daniel; Lee, Stephen Roger; Crawford, Mary H; Coltrin, Michael Elliott; Fini, Paul

    2013-06-01

    The goal of this NETL funded program was to improve the IQE in green (and longer wavelength) nitride- based LEDs structures by using semi-polar GaN planar orientations for InGaN multiple quantum well (MQW) growth. These semi-polar orientations have the advantage of significantly reducing the piezoelectric fields that distort the QW band structure and decrease electron-hole overlap. In addition, semipolar surfaces potentially provide a more open surface bonding environment for indium incorporation, thus enabling higher indium concentrations in the InGaN MQW. The goal of the proposed work was to select the optimal semi-polar orientation and explore wafer miscuts around this orientation that produced the highest quantum efficiency LEDs. At the end of this program we had hoped to have MQWs active regions at 540 nm with an IQE of 50% and an EQE of 40%, which would be approximately twice the estimated current state-of-the-art.

  15. Quality engineering tools focused on high power LED driver design using boost power stages in switch mode

    Science.gov (United States)

    Ileana, Ioan; Risteiu, Mircea; Marc, Gheorghe

    2016-12-01

    This paper is a part of our research dedicated to high power LED lamps designing. The boost-up selected technology wants to meet driver producers' tendency in the frame of efficiency and disturbances constrains. In our work we used modeling and simulation tools for implementing scenarios of the driver work when some controlling functions are executed (output voltage/ current versus input voltage and fixed switching frequency, input and output electric power transfer versus switching frequency, transient inductor voltage analysis, and transient out capacitor analysis). Some electrical and thermal stress conditions are also analyzed. Based on these aspects, a high reliable power LED driver has been designed.

  16. New treatment of cellulite with infrared-LED illumination applied during high-intensity treadmill training.

    Science.gov (United States)

    Paolillo, Fernanda Rossi; Borghi-Silva, Audrey; Parizotto, Nivaldo Antonio; Kurachi, Cristina; Bagnato, Vanderlei Salvador

    2011-08-01

    Phototherapy improves cellular activation which is an important factor for the treatment of cellulite. The objective of this research was to develop and evaluate the effects of a new (noninvasive and nonpharmacological) clinical procedure to improve body aesthetics: infrared-LED (850 nm) plus treadmill training. Twenty women (25-55 years old) participated in this study. They were separated in two groups: the control group, which carried out only the treadmill training (n = 10), and the LED group, with phototherapy during the treadmill training (n = 10). The training was performed for 45 minutes twice a week over 3 months at intensities between 85% and 90% maximal heart rate (HR(max)). The irradiation parameters were 39 mW/cm(2) and a fluence of 106 J/cm(2). The treatment was evaluated by interpreting body composition parameters, photographs and thermography. This was primarily a treatment for cellulite with a reduction of saddlebag and thigh circumference. At the same time, the treadmill training prevented an increase of body fat, as well as the loss of lean mass. Moreover, thermal images of the temperature modification of the thighs are presented. These positive effects can result in a further improvement of body aesthetics using infrared-LED together with treadmill training.

  17. The polarizing effect of arousal on negotiation.

    Science.gov (United States)

    Brown, Ashley D; Curhan, Jared R

    2013-10-01

    In this research, we examined the impact of physiological arousal on negotiation outcomes. Conventional wisdom and the prescriptive literature suggest that arousal should be minimized given its negative effect on negotiations, whereas prior research on misattribution of arousal suggests that arousal might polarize outcomes, either negatively or positively. In two experiments, we manipulated arousal and measured its effect on subjective and objective negotiation outcomes. Our results support the polarization effect. When participants had negative prior attitudes toward negotiation, arousal had a detrimental effect on outcomes, whereas when participants had positive prior attitudes toward negotiation, arousal had a beneficial effect on outcomes. These effects occurred because of the construal of arousal as negative or positive affect, respectively. Our findings have important implications not only for negotiation, but also for research on misattribution of arousal, which previously has focused on the target of evaluation, in contrast to the current research, which focused on the critical role of the perceiver.

  18. The subliminal affective priming effects of faces displaying various levels of arousal: an ERP study.

    Science.gov (United States)

    Li, Tian-Tian; Lu, Yong

    2014-11-07

    This study on the subliminal affective priming effects of faces displaying various levels of arousal employed event-related potentials (ERPs). The participants were asked to rate the arousal of ambiguous medium-arousing faces that were preceded by high- or low-arousing priming faces presented subliminally. The results revealed that the participants exhibited arousal-consistent variation in their arousal level ratings of the probe faces exclusively in the negative prime condition. Compared with high-arousing faces, the low-arousing faces tended to elicit greater late positive component (LPC, 450-660ms) and greater N400 (330-450ms) potentials. These findings support the following conclusions: (1) the effect of subliminal affective priming of faces can be detected in the affective arousal dimension; (2) valence may influence the subliminal affective priming effect of the arousal dimension of emotional stimuli; and (3) the subliminal affective priming effect of face arousal occurs when the prime stimulus affects late-stage processing of the probe.

  19. Copper Aluminum Nano Junction Normal Temperature Processes and Methods Applied to the LED High Heat Transfer Performance

    OpenAIRE

    Ming-Wen Wang; Bo-An Gao; Ding-Jun Lin; Jun-Han Chen

    2014-01-01

    High-power light-emitting diodes (LED) have extremely broad applications. However, with the job requirements of high-brightness and high color temperature from light-emitting diodes, it must be followed to enlarge the operating current, thus heating up more rapidly. If its heat dissipation problem cannot be effectively solved, operation will be prone to bring about color shift, and it may even considerably shorten its life. Moreover, application value will therefore be greatly reduced. So in ...

  20. Arousal modulates activity in the medial temporal lobe during a short-term relational memory task.

    Directory of Open Access Journals (Sweden)

    Christian eThoresen

    2012-01-01

    Full Text Available This study investigated the effect of arousal on short-term relational memory and its underlying cortical network. Seventeen healthy participants performed a picture by location, short-term relational memory task using emotional pictures. Functional Magnetic Resonance Imaging was used to measure the BOLD signal relative to task. Subjects’ own ratings of the pictures were used to obtain subjective arousal ratings. Subjective arousal was found to have a dose-dependent effect on activations in the prefrontal cortex, amygdala, hippocampus and in higher order visual areas. Serial position analyses showed that high arousal trials produced a stronger primacy and recency effect than low arousal trials. The results indicate that short-term relational memory may be facilitated by arousal and that this may be modulated by a dose-response function in arousal-driven neuronal regions.

  1. Effects of valence and arousal on written word recognition: time course and ERP correlates.

    Science.gov (United States)

    Citron, Francesca M M; Weekes, Brendan S; Ferstl, Evelyn C

    2013-01-15

    Models of affect assume a two-dimensional framework, composed of emotional valence and arousal. Although neuroimaging evidence supports a neuro-functional distinction of their effects during single word processing, electrophysiological studies have not yet compared the effects of arousal within the same category of valence (positive and negative). Here we investigate effects of arousal and valence on written lexical decision. Amplitude differences between emotion and neutral words were seen in the early posterior negativity (EPN), the late positive complex and in a sustained slow positivity. In addition, trends towards interactive effects of valence and arousal were observed in the EPN, showing larger amplitude for positive, high-arousal and negative, low-arousal words. The results provide initial evidence for interactions between arousal and valence during processing of positive words and highlight the importance of both variables in studies of emotional stimulus processing. Crown Copyright © 2012. Published by Elsevier Ireland Ltd. All rights reserved.

  2. Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

    Science.gov (United States)

    Greene, Ciara M; Flannery, Oliver; Soto, David

    2014-12-01

    The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

  3. Biaxial flexural strength of high-viscosity glass-ionomer cements heat-cured with an LED lamp during setting

    NARCIS (Netherlands)

    Molina, G. Fabian; Cabral, R.J.; Mazzola, I.; Lascano, L. Brain; Frencken, J.E.F.M.

    2013-01-01

    Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS) between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ket

  4. Dissociable effects of valence and arousal in adaptive executive control.

    Directory of Open Access Journals (Sweden)

    Christof Kuhbandner

    Full Text Available BACKGROUND: Based on introspectionist, semantic, and psychophysiological experimental frameworks, it has long been assumed that all affective states derive from two independent basic dimensions, valence and arousal. However, until now, no study has investigated whether valence and arousal are also dissociable at the level of affect-related changes in cognitive processing. METHODOLOGY/PRINCIPAL FINDINGS: We examined how changes in both valence (negative vs. positive and arousal (low vs. high influence performance in tasks requiring executive control because recent research indicates that two dissociable cognitive components are involved in the regulation of task performance: amount of current control (i.e., strength of filtering goal-irrelevant signals and control adaptation (i.e., strength of maintaining current goals over time. Using a visual pop-out distractor task, we found that control is exclusively modulated by arousal because interference by goal-irrelevant signals was largest in high arousal states, independently of valence. By contrast, control adaptation is exclusively modulated by valence because the increase in control after trials in which goal-irrelevant signals were present was largest in negative states, independent of arousal. A Monte Carlo simulation revealed that differential effects of two experimental factors on control and control adaptation can be dissociated if there is no correlation between empirical interference and conflict-driven modulation of interference, which was the case in the present data. Consequently, the observed effects of valence and arousal on adaptive executive control are indeed dissociable. CONCLUSIONS/SIGNIFICANCE: These findings indicate that affective influences on cognitive processes can be driven by independent effects of variations in valence and arousal, which may resolve several heterogeneous findings observed in previous studies on affect-cognition interactions.

  5. Valence, arousal, and task effects in emotional prosody processing

    Directory of Open Access Journals (Sweden)

    Silke ePaulmann

    2013-06-01

    Full Text Available Previous research suggests that emotional prosody processing is a highly rapid and complex process. In particular, it has been shown that different basic emotions can be differentiated in an early event-related brain potential (ERP component, the P200. Often, the P200 is followed by later long lasting ERPs such as the late positive complex (LPC. The current experiment set out to explore in how far emotionality and arousal can modulate these previously reported ERP components. In addition, we also investigated the influence of task demands (implicit vs. explicit evaluation of stimuli. Participants listened to pseudo-sentences (sentences with no lexical content spoken in six different emotions or in a neutral tone of voice while they either rated the arousal level of the speaker or their own arousal level. Results confirm that different emotional intonations can first be differentiated in the P200 component, reflecting a first emotional encoding of the stimulus possibly including a valence tagging process. A marginal significant arousal effect was also found in this time-window with high arousing stimuli eliciting a stronger P200 than low arousing stimuli. The P200 component was followed by a long lasting positive ERP between 400 and 750 ms. In this late time-window, both emotion and arousal effects were found. No effects of task were observed in either time-window. Taken together, results suggest that emotion relevant details are robustly decoded during early processing and late processing stages while arousal information is only reliably taken into consideration at a later stage of processing.

  6. Employing low-temperature barriers to achieve strain-relaxed and high-performance GaN-based LEDs.

    Science.gov (United States)

    Lin, Zhiting; Wang, Haiyan; Wang, Wenliang; Lin, Yunhao; Yang, Meijuan; Chen, Shuqi; Li, Guoqiang

    2016-05-30

    The epitaxial structure design of low-temperature barriers has been adopted to promote strain relaxation in multiple quantum well (MQWs) and achieve high-efficient GaN-based light-emitting diodes (LEDs). With these barriers, the relaxation value of wells increases from 0 to 4.59%. The strain-relaxed mechanism of low-temperature barriers is also discussed. The LED chip with the barriers grown at the TMIn flow of 75 sccm and the growth temperature of 830 °C has an optimal strain relaxation value of 1.53% in wells, and exhibits the largest light output power of 63.83 mW at the injection current of 65 mA, which is higher than that of conventional LED (51.89 mW) by 23%. In-depth studies reveal that the optimal low-temperature barriers remarkably promote the strain relaxation in wells without forming large density of crystalline defects. This achievement of high-efficiency LEDs sheds light on the future solid-state lighting applications.

  7. LED lamp

    Science.gov (United States)

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12

    There is herein described a lamp for providing white light comprising a plurality of light sources positioned on a substrate. Each of said light sources comprises a blue light emitting diode (LED) and a dome that substantially covers said LED. A first portion of said blue light from said LEDs is transmitted through said domes and a second portion of said blue light is converted into a red light by a first phosphor contained in said domes. A cover is disposed over all of said light sources that transmits at least a portion of said red and blue light emitted by said light sources. The cover contains a second phosphor that emits a yellow light in response to said blue light. The red, blue and yellow light combining to form the white light and the white light having a color rendering index (CRI) of at least about 80.

  8. Subjective Sexual Arousal to Films of Masturbation

    Science.gov (United States)

    Mosher, Donald L.; Abramson, Paul R.

    1977-01-01

    A film of a male or female masturbating was viewed by 96 males and 102 females. Males reported the highest level of sexual arousal to the female film and the lowest level of arousal to the male film. Females were sexually aroused by both films. (Author)

  9. Thermal behavior of silicon-copper micro vapor chamber for high power LEDs

    Science.gov (United States)

    Luo, Yi; Li, Zhi-xin; Zhou, Chuan-peng; Wang, Xiao-dong; You, Bo

    2016-03-01

    Micro vapor chamber (MVC) for light emitting diodes (LEDs) can be designed and fabricated to enhance the heat dissipation efficiency and improve the reliability. In this paper, we used photoresist SU-8 and electroforming copper (Cu) to fabricate three kinds of wick structures, which are star, radiation and parallel ones, and the substrate is silicon with thickness of 0.5 mm. Electroforming Cu on silicon to make micro wick structure was a critical step, the ampere-hour factor was used, and accordingly the electroforming time was predicted. The composition of electroforming solution and parameters of electroforming were optimized too. After charging and packaging, thermal behavior tests were carried out to study the heat dissipation performance of MVCs. When the input power was 8 W, the parallel wick structure reached the equivalent temperature of 69.0 °C in 226 s, while the others were higher than that. The experimental results prove that the wick structures have significant influence on the heat transfer capability of MVCs.

  10. Ultrabroad linewidth orange-emitting nanowires LED for high CRI laser-based white lighting and gigahertz communications.

    Science.gov (United States)

    Janjua, Bilal; Ng, Tien Khee; Zhao, Chao; Oubei, Hassan Makine; Shen, Chao; Prabaswara, Aditya; Alias, Mohd Sharizal; Alhamoud, Abdullah Ali; Alatawi, Abdullah Awaad; Albadri, Abdulrahman M; Alyamani, Ahmed Y; El-Desouki, Munir M; Ooi, Boon S

    2016-08-22

    Group-III-nitride laser diode (LD)-based solid-state lighting device has been demonstrated to be droop-free compared to light-emitting diodes (LEDs), and highly energy-efficient compared to that of the traditional incandescent and fluorescent white light systems. The YAG:Ce3+ phosphor used in LD-based solid-state lighting, however, is associated with rapid degradation issue. An alternate phosphor/LD architecture, which is capable of sustaining high temperature, high power density, while still intensity- and bandwidth-tunable for high color-quality remained unexplored. In this paper, we present for the first time, the proof-of-concept of the generation of high-quality white light using an InGaN-based orange nanowires (NWs) LED grown on silicon, in conjunction with a blue LD, and in place of the compound-phosphor. By changing the relative intensities of the ultrabroad linewidth orange and narrow-linewidth blue components, our LED/LD device architecture achieved correlated color temperature (CCT) ranging from 3000 K to above 6000K with color rendering index (CRI) values reaching 83.1, a value unsurpassed by the YAG-phosphor/blue-LD counterpart. The white-light wireless communications was implemented using the blue LD through on-off keying (OOK) modulation to obtain a data rate of 1.06 Gbps. We therefore achieved the best of both worlds when orange-emitting NWs LED are utilized as "active-phosphor", while blue LD is used for both color mixing and optical wireless communications.

  11. Ultrabroad linewidth orange-emitting nanowires LED for high CRI laser-based white lighting and gigahertz communications

    KAUST Repository

    Janjua, Bilal

    2016-08-10

    Group-III-nitride laser diode (LD)-based solid-state lighting device has been demonstrated to be droop-free compared to light-emitting diodes (LEDs), and highly energy-efficient compared to that of the traditional incandescent and fluorescent white light systems. The YAG:Ce3+ phosphor used in LD-based solid-state lighting, however, is associated with rapid degradation issue. An alternate phosphor/LD architecture, which is capable of sustaining high temperature, high power density, while still intensity- and bandwidth-tunable for high color-quality remained unexplored. In this paper, we present for the first time, the proof-of-concept of the generation of high-quality white light using an InGaN-based orange nanowires (NWs) LED grown on silicon, in conjunction with a blue LD, and in place of the compound-phosphor. By changing the relative intensities of the ultrabroad linewidth orange and narrow-linewidth blue components, our LED/LD device architecture achieved correlated color temperature (CCT) ranging from 3000 K to above 6000K with color rendering index (CRI) values reaching 83.1, a value unsurpassed by the YAG-phosphor/blue-LD counterpart. The white-light wireless communications was implemented using the blue LD through on-off keying (OOK) modulation to obtain a data rate of 1.06 Gbps. We therefore achieved the best of both worlds when orange-emitting NWs LED are utilized as “active-phosphor”, while blue LD is used for both color mixing and optical wireless communications.

  12. Time dependent and temperature dependent properties of the forward voltage characteristic of InGaN high power LEDs

    Directory of Open Access Journals (Sweden)

    P. L. Fulmek

    2017-03-01

    Full Text Available Estimating the junction temperature and its dynamic behavior in dependence of various operating conditions is an important issue, since these properties influence the optical characteristics as well as the aging processes of a light-emitting diode (LED. Particularly for high-power LEDs and pulsed operation, the dynamic behavior and the resulting thermal cycles are of interest. The forward voltage method relies on the existence of a time-independent unique triple of forward-voltage, forward-current, and junction temperature. These three figures should as well uniquely define the optical output power and spectrum, as well as the loss power of the LED, which is responsible for an increase of the junction temperature. From transient FEM-simulations one may expect an increase of the temperature of the active semiconductor layer of some 1/10 K within the first 10 μs. Most of the well-established techniques for junction temperature measurement via forward voltage method evaluate the measurement data several dozens of microseconds after switching on or switching off and estimate the junction temperature by extrapolation towards the time of switching. In contrast, the authors developed a measurement procedure with the focus on the first microseconds after switching. Besides a fast data acquisition system, a precise control of the switching process is required, i.e. a precisely defined current pulse amplitude with fast rise-time and negligible transient by-effects. We start with a short description of the measurement setup and the newly developed control algorithm for the generation of short current pulses. The thermal characterization of the LED chip during the measurement procedures is accomplished by an IR thermography system and transient finite element simulations. The same experimental setup is used to investigate the optical properties of the LED in an Ulbricht-sphere. Our experiments are performed on InGaN LED chips mounted on an Al based

  13. Optogenetic Investigation of Arousal Circuits.

    Science.gov (United States)

    Tyree, Susan M; de Lecea, Luis

    2017-08-15

    Modulation between sleep and wake states is controlled by a number of heterogeneous neuron populations. Due to the topological proximity and genetic co-localization of the neurons underlying sleep-wake state modulation optogenetic methods offer a significant improvement in the ability to benefit from both the precision of genetic targeting and millisecond temporal control. Beginning with an overview of the neuron populations mediating arousal, this review outlines the progress that has been made in the investigation of arousal circuits since the incorporation of optogenetic techniques and the first in vivo application of optogenetic stimulation in hypocretin neurons in the lateral hypothalamus. This overview is followed by a discussion of the future progress that can be made by incorporating more recent technological developments into the research of neural circuits.

  14. Arousing Students' Interest Through Games

    Institute of Scientific and Technical Information of China (English)

    李新清

    2013-01-01

    As is well known,interest is the best teacher and it can cause motivation. "Motivation is what moves the students from boredom to interest, It's something like engine and steering wheel of an automobile . "(Spolsky. B. 1989 ) So I decided to adopt some different kinds of games in my lessons to arouse the learners' interest and motivate them , and help them keep up their English learning.

  15. Emotional arousal predicts intertemporal choice.

    Science.gov (United States)

    Lempert, Karolina M; Johnson, Eli; Phelps, Elizabeth A

    2016-08-01

    People generally prefer immediate rewards to rewards received after a delay, often even when the delayed reward is larger. This phenomenon is known as temporal discounting. It has been suggested that preferences for immediate rewards may be due to their being more concrete than delayed rewards. This concreteness may evoke an enhanced emotional response. Indeed, manipulating the representation of a future reward to make it more concrete has been shown to heighten the reward's subjective emotional intensity, making people more likely to choose it. Here the authors use an objective measure of arousal-pupil dilation-to investigate if emotional arousal mediates the influence of delayed reward concreteness on choice. They recorded pupil dilation responses while participants made choices between immediate and delayed rewards. They manipulated concreteness through time interval framing: delayed rewards were presented either with the date on which they would be received (e.g., "$30, May 3"; DATE condition, more concrete) or in terms of delay to receipt (e.g., "$30, 7 days; DAYS condition, less concrete). Contrary to prior work, participants were not overall more patient in the DATE condition. However, there was individual variability in response to time framing, and this variability was predicted by differences in pupil dilation between conditions. Emotional arousal increased as the subjective value of delayed rewards increased, and predicted choice of the delayed reward on each trial. This study advances our understanding of the role of emotion in temporal discounting. (PsycINFO Database Record

  16. A new Cu(TiBN x ) alloy film for boosting the per-watt illuminance of high power LEDs

    Science.gov (United States)

    Lin, Chon-Hsin

    2017-01-01

    In this study, a new Cu(TiBN x ) alloy film has been explored and utilized as a flexible heat dissipation layer for the substrate of high power LEDs to boost their per-watt illuminance by reducing the thermal resistance and increasing the thermal conductivity of the substrate. The new film is a Cu-alloy seed layer fabricated by co-sputtering Cu and TiB in an N2 atmosphere on a Ta/polyimide (Ta/PI) substrate. The film was then annealed at 340 °C for 1 h without noticeable Cu oxide formation around the film-substrate interface. The new film exhibits low resistivity, high thermal conductivity and low thermal resistance, rendering a substantially higher per-watt illuminance for LEDs that utilize the film as their additional heat dissipation layer. The experimental results gained in the study appear to confirm the new Cu(TiBN x ) film as a good candidate material, at least, for boosting the per-watt illuminance of high power LEDs.

  17. Changes in blood glucose and salivary cortisol are not necessary for arousal to enhance memory in young or older adults.

    Science.gov (United States)

    Gore, Jane B; Krebs, Desiree L; Parent, Marise B

    2006-06-01

    Emotional arousal enhances memory, and this memory-enhancing effect may involve neurochemicals released by arousal, such as glucose and cortisol. Physiological consequences of arousal change with age, and these changes may contribute to age-related memory decline. The present study examined whether emotionally arousing pictures would affect glucose and cortisol levels and enhance memory in young and older adults. Blood glucose and salivary cortisol were measured once before and six times after young and old adults viewed either 60 highly arousing or 60 relatively neutral pictures. Recall for the stimuli was measured 75 min later. The results indicated that recall was impaired in older adults. Arousal as measured by self-report enhanced recall in both young and older adults. However, arousal did not affect glucose or cortisol levels in either group. These findings demonstrate that changes in blood glucose or salivary cortisol levels are not necessary for arousal to enhance memory.

  18. Schlieren study of a sonic jet injected into a supersonic cross flow using high-current pulsed LEDs

    CERN Document Server

    Giskes, Ella; Segerink, Frans B; Venner, Cornelis H

    2016-01-01

    In the research of supersonic flows, flow visualization continues to be an important tool, and even today it is difficult to create high quality images. In this study we present a low-cost and easy-to use Schlieren setup. The setup makes use of LEDs, pulsed with high currents to increase the optical output to sufficient levels, exploiting the advantages of LED light over conventional light sources. As a test-case we study the interaction of a Mach 1.7 cross flow and a transverse underexpanded jet, which is commonly studied considering the mixing and combustion in scramjet engines. Using 130 nanosecond LED light pulses, we captured the flow structures sharply and in great detail. We observed a large-gradient wave, which was seen in numerical studies but hitherto not reported in experiments. Furthermore, we demonstrate that time-correlated images can be obtained with this Schlieren setup, so that also flow unsteadiness can be studied, such as the movement of shock waves and vortices.

  19. The Effectiveness of Peer-Led FAS/FAE Prevention Presentations in Middle and High Schools

    Science.gov (United States)

    Boulter, Lyn

    2007-01-01

    Pregnant women and women who might become pregnant, including middle school- and high school-age adolescents, continue to consume alcohol, placing themselves at risk of having a child with the effects of prenatal alcohol exposure. However, most prevention programs that attempt to increase public awareness and knowledge of FAS and related disorders…

  20. The Effectiveness of Peer-Led FAS/FAE Prevention Presentations in Middle and High Schools

    Science.gov (United States)

    Boulter, Lyn

    2007-01-01

    Pregnant women and women who might become pregnant, including middle school- and high school-age adolescents, continue to consume alcohol, placing themselves at risk of having a child with the effects of prenatal alcohol exposure. However, most prevention programs that attempt to increase public awareness and knowledge of FAS and related disorders…

  1. Student-Led Project Teams: Significance of Regulation Strategies in High- and Low-Performing Teams

    Science.gov (United States)

    Ainsworth, Judith

    2016-01-01

    We studied group and individual co-regulatory and self-regulatory strategies of self-managed student project teams using data from intragroup peer evaluations and a postproject survey. We found that high team performers shared their research and knowledge with others, collaborated to advise and give constructive criticism, and demonstrated moral…

  2. Student-Led Project Teams: Significance of Regulation Strategies in High- and Low-Performing Teams

    Science.gov (United States)

    Ainsworth, Judith

    2016-01-01

    We studied group and individual co-regulatory and self-regulatory strategies of self-managed student project teams using data from intragroup peer evaluations and a postproject survey. We found that high team performers shared their research and knowledge with others, collaborated to advise and give constructive criticism, and demonstrated moral…

  3. The effect of exercise-induced arousal on chosen tempi for familiar melodies

    OpenAIRE

    Jakubowski, Kelly; Halpern, Andrea; Grierson, Mick; Stewart, Lauren

    2014-01-01

    Many previous studies have shown that arousal affects time perception, suggesting a direct influence of arousal on the speed of the pacemaker of the internal clock. However, it is unknown whether arousal influences the mental representation of tempo (speed) for highly familiar and complex stimuli, such as well-known melodies, that have long-term representations in memory. Previous research suggests that mental representations of the tempo of familiar melodies are stable over time; the aim of ...

  4. Volume structuring of high power LED encapsulates by femtosecond laser direct writing

    Energy Technology Data Exchange (ETDEWEB)

    Kuna, L.; Sommer, C.; Zinterl, E.; Krenn, J.R.; Wenzl, F.P. [Joanneum Research Forschungsges. mbH, Institute of Nanostructured Materials and Photonics, Weiz (Austria); Pachler, P.; Hartmann, P.; Tasch, S. [TridonicAtco Optoelectronics GmbH, Jennersdorf (Austria); Leising, G. [Graz University of Technology, Institute of Solid State Physics, Graz (Austria)

    2008-11-15

    We report on the micro-fabrication of diffractive optical elements (DOEs) such as 1D, 2D and concentric grating structures inside the volume of thin silicone films by femtosecond laser direct writing. In addition, we show that such structures can also be integrated into silicone films that act as encapsulation layers of high power light-emitting diodes. The latter strategy opens new possibilities to homogenize and to control the light emitted from such devices. (orig.)

  5. Strain relief InGaN/GaN MQW micro-pillars for high brightness LEDs

    KAUST Repository

    Shen, Chao

    2013-01-01

    Micro-structured group-III-nitrides are considered as promising strain relief structures for high efficiency solid state lighting. In this work, the strain field in InGaN/GaN multi-quantum wells (MQWs) micro-pillars is investigated using micro-Raman spectroscopy and the design of micro-pillars were studied experimentally. We distinguished the strained and strain-relieved signatures of the GaN layer from the E2 phonon peak split from the Raman scattering signatures at 572 cm-1 and 568 cm-1, respectively. The extent of strain relief is examined considering the height and size of micro-pillars fabricated using focused ion beam (FIB) micro-machining technique. A significant strain relief can be achieved when one micro-machined through the entire epi-layers, 3 μm in our study. The dependence of strain relief on micro-pillar diameter (D) suggested that micro-pillar with D < 3 μm showed high degree of strain relief. Our results shed new insights into designing strain-relieved InGaN/GaN microstructures for high brightness light emitting diode arrays. © 2013 IEEE.

  6. A unifying computational framework for stability and flexibility of arousal

    Directory of Open Access Journals (Sweden)

    Christin eKosse

    2014-10-01

    Full Text Available Arousal and consciousness flexibly adjust to salient cues, but remain stable despite noise and disturbance. Diverse, highly interconnected neural networks govern the underlying transitions of behavioural state; these networks are robust but very complex. Frameworks from systems engineering provide powerful tools for understanding functional logic behind component complexity. From a general systems viewpoint, a minimum of three communicating control modules may enable flexibility and stability to coexist. Comparators would subtract current arousal from desired arousal, producing an error signal. Regulators would compute control signals from this error. Generators would convert control signals into arousal, which is fed back to comparators, to make the system noise-proof through self-correction. Can specific neurons correspond to these control elements? To explore this, here we consider the brain-wide orexin/hypocretin network, which is experimentally established to be vital for flexible and stable arousal. We discuss whether orexin neurons may act as comparators, and their target neurons as regulators and generators. Experiments are proposed for testing such predictions, based on computational simulations showing that comparators, regulators, and generators have distinct temporal signatures of activity. If some regulators integrate orexin-communicated errors, robust arousal control may be achieved via integral feedback (a basic engineering strategy for tracking a set-point despite noise. An integral feedback view also suggests functional roles for specific molecular aspects, such as differing life-spans of orexin peptides. The proposed framework offers a unifying logic for molecular, cellular, and network details of arousal systems, and provides insight into behavioral state transitions, complex behaviour, and bases for disease.

  7. Influence of emotional valence and arousal on the spread of activation in memory.

    Science.gov (United States)

    Jhean-Larose, Sandra; Leveau, Nicolas; Denhière, Guy

    2014-11-01

    Controversy still persists on whether emotional valence and arousal influence cognitive activities. Our study sought to compare how these two factors foster the spread of activation within the semantic network. In a lexical decision task, prime words were varied depending on the valence (pleasant or unpleasant) or on the level of emotional arousal (high or low). Target words were carefully selected to avoid semantic priming effects, as well as to avoid arousing specific emotions (neutral). Three SOA durations (220, 420 and 720 ms) were applied across three independent groups. Results indicate that at 220 ms, the effect of arousal is significantly higher than the effect of valence in facilitating spreading activation while at 420 ms, the effect of valence is significantly higher than the effect of arousal in facilitating spreading activation. These findings suggest that affect is a sequential process involving the successive intervention of arousal and valence.

  8. High Luminescence White LEDs Prepared with 2D Island-Pattern of Quantum Dots Dispersed Photopolymer Films

    Directory of Open Access Journals (Sweden)

    Hyun-Guk Hong

    2015-01-01

    Full Text Available Since the reabsorption loss among different size quantum dots (QDs is a critical issue in the QD based white LEDs, we proposed and fabricated new film structure of 2D island-patterns consisting of separate green and red QDs dispersed photopolymer patterns in a zigzag form. A small air-gap such as 60 μm between QD islands helps to control the optical path at the interface to reduce the lateral reabsorption loss to enhance the optical efficiency of white LED. The 2D island-patterns of QD phosphor film were fabricated using a UV imprinting process and compared the optical efficiency with the other QD film structure prepared with same QD concentrations and thicknesses such as a mixed and separately layered QD structure. Experimental and simulation analysis were performed to confirm the better optical efficiency from the 2D island-patterns of QD films due to the reduced reabsorption loss. High luminescence white LED was finally realized with 2D island-patterns of QD film, resulting in a luminous efficiency of 62.2 lm/W and CRI of 83 with CCT of 4537 K at the operation current of 60 mA.

  9. Biaxial Flexural Strength of High-Viscosity Glass-Ionomer Cements Heat-Cured with an LED Lamp during Setting

    Directory of Open Access Journals (Sweden)

    Gustavo Fabián Molina

    2013-01-01

    Full Text Available Adding heat to glass ionomers during setting might improve mechanical properties. The aim was to compare the biaxial flexural strength (BFS between and within four glass ionomers, by time of exposure to a high-intensity LED light-curing unit. Materials and methods. Samples of Fuji 9 Gold Label, Ketac Molar Easymix, ChemFil Rock, and the EQUIA system were divided into three treatment groups (n=30: without heating (Group 1, heated with LED lamp of 1400 mW/cm2 for 30 s while setting (Group 2, and heated with LED lamp of 1400 mW/cm2 for 60 s while setting (Group 3. Samples were stored for 48 hours in distilled water at 37°C until tested. BFS was tested, using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed, using ANOVA test with the Bonferroni correction (α=0.05. Heating the glass-ionomer cements with an LED curing light of 1400 mW/cm2 during setting for 30 s increased the BFS value of all GICs. No statistically significant difference in mean BFS scores was found between the EQUIA system and ChemFil Rock at 30 s and 60 s. The mean BFS value was statistically significantly higher for the EQUIA system and ChemFil Rock than for Fuji 9 Gold Label and Ketac Molar Easymix at all exposure times.

  10. Highly efficient low color temperature organic LED using blend carrier modulation layer

    Science.gov (United States)

    Hsieh, Yao-Ching; Chen, Szu-Hao; Shen, Shih-Ming; Wang, Ching-Chiun; Chen, Chien-Chih; Jou, Jwo-Huei

    2012-10-01

    Color temperature (CT) of light has great effect on human physiology and psychology, and low CT light, minimizing melatonin suppression and decreasing the risk of breast, colorectal, and prostate cancer. We demonstrates the incorporation of a blend carrier modulation interlayer (CML) between emissive layers to improve the device performance of low CT organic light emitting diodes, which exhibits an external quantum efficiency of 22.7% and 36 lm W-1 (54 cd A-1) with 1880 K at 100 cd m-2, or 20.8% and 29 lm W-1 (50 cd A-1) with 1940 K at 1000 cd m-2. The result shows a CT much lower than that of incandescent bulbs, which is 2500 K with 15 lmW-1 efficiency, and even as low as that of candles, which is 2000 K with 0.1 lmW-1. The high efficiency of the proposed device may be attributed to its CML, which helps effectively distribute the entering carriers into the available recombination zones.

  11. A little adjustment of synthetic strategy led to a new highly repeated heteropolyblue: Structure, characterizations and photocatalytic properties

    Science.gov (United States)

    Chen, Wu-Hua; Zhang, Zhu-Sen; Zhao, Jin-Hua; Qiu, Ze-Hai; Yuan, Qiu-Lan; Huang, Tian-Fu; Lin, Xue-Yu; Hu, Zhi-Biao

    2017-06-01

    Hydrothermal synthesis is known as the most efficient method to prepare novel structural polyoxometalate (POM)-based materials, but controlled synthesis of a structure-directing POM is always challenging task. The experimental repeatability is usually one of the key topics. To explore a reliable hydrothermal synthesis approach for new POMs will be a meaningful work. Our previous work, which we have hydrothermally synthesized the first Cr-complexes-capped Keggin-type POM, [Hdma]3[H2phen]{[Cr(phen)]2[MoV8MoVI4O36(PO4)]}·nH2O (n ≈ 2) (Chen et al., polyhedron, 2015, 85, 117), afford us some commendable synthetic experiences, arouse us some introspections as well for its tricky preparation conditions and low experimental repeatability. Based on the aforementioned work, a new high-repetition-rate and more steady heteropolyblue, [H3O]0.5(Hdma)2.5(dma)0.25{[Cr(phen)]2[MoV6MoVI6O8(PO4)]}·2H2O (1) (dma = dimethylamine (C2H7N), phen = 1,10-phenanthroline (C12H8N2)), has been successfully obtained by virtue of reasonably adjusting synthetic strategy. The adjustment of synthetic strategy includes controlling ratio of reactants and aging time, reasonably using redoxes and stepwise self-assembly plans. Compound 1 is the second POM with Keggin-type polyanion capped by Cr-complexes. Experiments demonstrate that compound 1 has good catalytic activity in the both degradation reactions of rhodamine B (RHB) and methyl orange (MO) under ultraviolet (UV)-light and oxidant H2O2 conditions. Detailed structural characterizations include single-crystal X-ray diffraction (XRD) analyses, energy-dispersive X-ray spectrometry (EDS) analyses, elemental analyses, cerate oxidimetry, powder XRD, fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible-near-infrared (UV-Vis-NIR) solid diffuse reflection spectrum and X-ray photoelectron spectroscopy (XPS) analyses. The electrochemical property (cyclic voltammetry (CV)) of compound 1 has also been studied.

  12. Pupil-linked arousal determines variability in perceptual decision making.

    Science.gov (United States)

    Murphy, Peter R; Vandekerckhove, Joachim; Nieuwenhuis, Sander

    2014-09-01

    Decision making between several alternatives is thought to involve the gradual accumulation of evidence in favor of each available choice. This process is profoundly variable even for nominally identical stimuli, yet the neuro-cognitive substrates that determine the magnitude of this variability are poorly understood. Here, we demonstrate that arousal state is a powerful determinant of variability in perceptual decision making. We measured pupil size, a highly sensitive index of arousal, while human subjects performed a motion-discrimination task, and decomposed task behavior into latent decision making parameters using an established computational model of the decision process. In direct contrast to previous theoretical accounts specifying a role for arousal in several discrete aspects of decision making, we found that pupil diameter was uniquely related to a model parameter representing variability in the rate of decision evidence accumulation: Periods of increased pupil size, reflecting heightened arousal, were characterized by greater variability in accumulation rate. Pupil diameter also correlated trial-by-trial with specific patterns of behavior that collectively are diagnostic of changing accumulation rate variability, and explained substantial individual differences in this computational quantity. These findings provide a uniquely clear account of how arousal state impacts decision making, and may point to a relationship between pupil-linked neuromodulation and behavioral variability. They also pave the way for future studies aimed at augmenting the precision with which people make decisions.

  13. The Relationship of Stress Arousal and Stress Prone Personality Traits to Menstrual Distress.

    Science.gov (United States)

    Marini, David C.

    The various relationships of stress arousal and stress-prone personality traits to menstrual distress were investigated in order to quantify psychophysiological arousal differences between high and low menstrual distress symptom reporters and examine differences in stress-prone personality traits between high and low menstrual distress symptom…

  14. Adolescent pertussis-induced partial arousal parasomnia.

    Science.gov (United States)

    Eidlitz-Markus, Tal; Zeharia, Avraham

    2006-10-01

    The aim of the study was to assess neurologic complications of pertussis infection. A file review of all children (age 7-18 years) in our hospital with serology-positive pertussis infection admitted from 1995 to 2005 yielded six patients with neurologic symptoms in whom electroencephalographic studies were performed. Data were collected on their clinical symptoms, electroencephalographic findings, final diagnosis, and outcome. The six patients accounted for 10% of all children diagnosed with pertussis during the study period. Their ages ranged from 10 to 15.5 years. All the children were referred by their primary physician because of a suspicion of epilepsy on the basis of parental reports of inefficient attempts to breathe during sleep accompanied by high-pitched sounds and sounds of suffocation, and sleepwalking. The children were amnesic for the episodes. However, findings on electroencephalogram taken during sleep were negative in all cases. The final diagnosis was partial arousal parasomnia. The symptoms of parasomnia disappeared with resolution of the symptoms of the pertussis infection. In conclusion, partial arousal parasomnia may be induced by pertussis infection. Further studies in larger groups are required to confirm this association.

  15. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays

    Directory of Open Access Journals (Sweden)

    Jakub Pekárek

    2016-09-01

    Full Text Available This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm − 2 ·s − 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  16. Infrared LED Enhanced Spectroscopic CdZnTe Detector Working under High Fluxes of X-rays.

    Science.gov (United States)

    Pekárek, Jakub; Dědič, Václav; Franc, Jan; Belas, Eduard; Rejhon, Martin; Moravec, Pavel; Touš, Jan; Voltr, Josef

    2016-09-27

    This paper describes an application of infrared light-induced de-polarization applied on a polarized CdZnTe detector working under high radiation fluxes. We newly demonstrate the influence of a high flux of X-rays and simultaneous 1200-nm LED illumination on the spectroscopic properties of a CdZnTe detector. CdZnTe detectors operating under high radiation fluxes usually suffer from the polarization effect, which occurs due to a screening of the internal electric field by a positive space charge caused by photogenerated holes trapped at a deep level. Polarization results in the degradation of detector charge collection efficiency. We studied the spectroscopic behavior of CdZnTe under various X-ray fluxes ranging between 5 × 10 5 and 8 × 10 6 photons per mm 2 per second. It was observed that polarization occurs at an X-ray flux higher than 3 × 10 6 mm - 2 ·s - 1 . Using simultaneous illumination of the detector by a de-polarizing LED at 1200 nm, it was possible to recover X-ray spectra originally deformed by the polarization effect.

  17. High-voltage thin-film GaN LEDs fabricated on ceramic substrates: the alleviated droop effect at 670 W/cm(2).

    Science.gov (United States)

    Tsai, M L; Liao, J H; Yeh, J H; Hsu, T C; Hon, S J; Chung, T Y; Lai, K Y

    2013-11-04

    High-voltage thin-film GaN LEDs with the emission wavelength of 455 nm were fabricated on ceramic substrates (230 W/m · K). The high-voltage operation was achieved by three cascaded sub-LEDs with dielectric passivation and metal bridges conformally deposited on the side walls. Under the driving power of 670 W/cm(2), the high-voltage LEDs exhibit much alleviated efficiency droop and the operative temperature below 80 °C. The excellent performances were attributed to the improved current spreading within each sub-LED and the superior heat sinking of the ceramic substrate.

  18. Male bisexual arousal: a matter of curiosity?

    Science.gov (United States)

    Rieger, Gerulf; Rosenthal, Allen M; Cash, Brian M; Linsenmeier, Joan A W; Bailey, J Michael; Savin-Williams, Ritch C

    2013-12-01

    Conflicting evidence exists regarding whether bisexual-identified men are sexually aroused to both men and women. We hypothesized that a distinct characteristic, level of curiosity about sexually diverse acts, distinguishes bisexual-identified men with and without bisexual arousal. Study 1 assessed men's (n=277) sexual arousal via pupil dilation to male and female sexual stimuli. Bisexual men were, on average, higher in their sexual curiosity than other men. Despite this general difference, only bisexual-identified men with elevated sexual curiosity showed bisexual arousal. Those lower in curiosity had responses resembling those of homosexual men. Study 2 assessed men's (n=72) sexual arousal via genital responses and replicated findings of Study 1. Study 3 provided information on the validity on our measure of sexual curiosity by relating it to general curiosity and sexual sensation seeking (n=83). Based on their sexual arousal and personality, at least two groups of men identify as bisexual.

  19. Highly efficient narrow-band green and red phosphors enabling wider color-gamut LED backlight for more brilliant displays.

    Science.gov (United States)

    Wang, Le; Wang, Xiaojun; Kohsei, Takahashi; Yoshimura, Ken-ichi; Izumi, Makoto; Hirosaki, Naoto; Xie, Rong-Jun

    2015-11-02

    In this contribution, we propose to combine both narrow-band green (β-sialon:Eu(2+)) and red (K(2)SiF(6):Mn(4+)) phosphors with a blue InGaN chip to achieve white light-emitting diodes (wLEDs) with a large color gamut and a high efficiency for use as the liquid crystal display (LCD) backlighting. β-sialon:Eu(2+), prepared by a gas-pressure sinteing technique, has a peak emission at 535 nm, a full width at half maximum (FWHM) of 54 nm, and an external quantum efficiency of 54.0% under the 450 nm excitation. K(2)SiF(6):Mn(4+) was synthesized by a twe-step co-precipitation methods, and exhibits a sharp line emission spectrum with the most intensified peak at 631 nm, a FWHM of ~3 nm, and an external quantum efficiency of 54.5%. The prepared three-band wLEDs have a high color temperature of 11,184 - 13,769 K (i.e., 7,828 - 8,611 K for LCD displays), and a luminous efficacy of 91 - 96 lm/W, measured under an applied current of 120 mA. The color gamut defined in the CIE 1931 and CIE 1976 color spaces are 85.5 - 85.9% and 94.3 - 96.2% of the NTSC stanadard, respectively. These optical properties are better than those phosphor-cpnverted wLED backlights using wide-band green or red phosphoprs, suggesting that the two narrow-band phosphors investigated are the most suitable luminescent materials for achieving more bright and vivid displays.

  20. Hyper-arousal decreases human visual thresholds.

    Directory of Open Access Journals (Sweden)

    Adam J Woods

    Full Text Available Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0-2° C water, a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1 and contrast thresholds (Experiment 2 were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal's ability to decrease visual thresholds has important implications for survival, sports, and everyday life.

  1. Hyper-arousal decreases human visual thresholds.

    Science.gov (United States)

    Woods, Adam J; Philbeck, John W; Wirtz, Philip

    2013-01-01

    Arousal has long been known to influence behavior and serves as an underlying component of cognition and consciousness. However, the consequences of hyper-arousal for visual perception remain unclear. The present study evaluates the impact of hyper-arousal on two aspects of visual sensitivity: visual stereoacuity and contrast thresholds. Sixty-eight participants participated in two experiments. Thirty-four participants were randomly divided into two groups in each experiment: Arousal Stimulation or Sham Control. The Arousal Stimulation group underwent a 50-second cold pressor stimulation (immersing the foot in 0-2° C water), a technique known to increase arousal. In contrast, the Sham Control group immersed their foot in room temperature water. Stereoacuity thresholds (Experiment 1) and contrast thresholds (Experiment 2) were measured before and after stimulation. The Arousal Stimulation groups demonstrated significantly lower stereoacuity and contrast thresholds following cold pressor stimulation, whereas the Sham Control groups showed no difference in thresholds. These results provide the first evidence that hyper-arousal from sensory stimulation can lower visual thresholds. Hyper-arousal's ability to decrease visual thresholds has important implications for survival, sports, and everyday life.

  2. Efficient Disinfection of Tap and Surface Water with Single High Power 285 nm LED and Square Quartz Tube

    Directory of Open Access Journals (Sweden)

    Martin Hessling

    2016-01-01

    Full Text Available A small water disinfection system based on the combination of a strong single 25 mW LED with a wavelength of 285 nm and a short quartz tube with an outer rectangular cross section is presented. For the disinfection tests clear tap water and slightly turbid and yellow pond water are contaminated with high concentrations of Escherichia coli bacteria. These water samples are exposed to the germicidal 285 nm LED radiation while they flow through the quartz tube. The portion of surviving germs is determined by membrane filtration for different water qualities and flow rates. For clear tap water the bacteria concentration can be reduced by at least three orders of magnitude up to flow rates of about 20 L/h. In pond water the maximum flow rate for such a reduction is less than 3 L/h. These high disinfection capabilities and the small size of this system, allow its integration in medical systems for point of use disinfection or even its application in the Third World for decentralized water disinfection powered by small solar cells, because this disinfection capacity should be sufficient for small groups or families.

  3. Crossmodal transfer of arousal, but not pleasantness, from the musical to the visual domain.

    Science.gov (United States)

    Marin, Manuela M; Gingras, Bruno; Bhattacharya, Joydeep

    2012-06-01

    Arousal and valence (pleasantness) are considered primary dimensions of emotion. However, the degree to which these dimensions interact in emotional processing across sensory modalities is poorly understood. We addressed this issue by applying a crossmodal priming paradigm in which auditory primes (Romantic piano solo music) varying in arousal and/or pleasantness were sequentially paired with visual targets (IAPS pictures). In Experiment 1, the emotion spaces of 120 primes and 120 targets were explored separately in addition to the effects of musical training and gender. Thirty-two participants rated their felt pleasantness and arousal in response to primes and targets on equivalent rating scales as well as their familiarity with the stimuli. Musical training was associated with elevated familiarity ratings for high-arousing music and a trend for elevated arousal ratings, especially in response to unpleasant musical stimuli. Males reported higher arousal than females for pleasant visual stimuli. In Experiment 2, 40 nonmusicians rated their felt arousal and pleasantness in response to 20 visual targets after listening to 80 musical primes. Arousal associated with the musical primes modulated felt arousal in response to visual targets, yet no such transfer of pleasantness was observed between the two modalities. Experiment 3 sought to rule out the possibility of any order effect of the subjective ratings, and responses of 14 nonmusicians replicated results of Experiment 2. This study demonstrates the effectiveness of the crossmodal priming paradigm in basic research on musical emotions.

  4. Emotional arousal amplifies the effects of biased competition in the brain.

    Science.gov (United States)

    Lee, Tae-Ho; Sakaki, Michiko; Cheng, Ruth; Velasco, Ricardo; Mather, Mara

    2014-12-01

    The arousal-biased competition model predicts that arousal increases the gain on neural competition between stimuli representations. Thus, the model predicts that arousal simultaneously enhances processing of salient stimuli and impairs processing of relatively less-salient stimuli. We tested this model with a simple dot-probe task. On each trial, participants were simultaneously exposed to one face image as a salient cue stimulus and one place image as a non-salient stimulus. A border around the face cue location further increased its bottom-up saliency. Before these visual stimuli were shown, one of two tones played: one that predicted a shock (increasing arousal) or one that did not. An arousal-by-saliency interaction in category-specific brain regions (fusiform face area for salient faces and parahippocampal place area for non-salient places) indicated that brain activation associated with processing the salient stimulus was enhanced under arousal whereas activation associated with processing the non-salient stimulus was suppressed under arousal. This is the first functional magnetic resonance imaging study to demonstrate that arousal can enhance information processing for prioritized stimuli while simultaneously impairing processing of non-prioritized stimuli. Thus, it goes beyond previous research to show that arousal does not uniformly enhance perceptual processing, but instead does so selectively in ways that optimizes attention to highly salient stimuli.

  5. [Research on the Highly Stable White LED with CdSe/ZnS Quantum Dot as Light Conversion Layer].

    Science.gov (United States)

    Cao, Jin; Zhou, Jie; Xie, Jing-weil; Chen, An-ping; Zhang, Xuel; Yin, Lu-qiao; Zhang, Jian-hua

    2016-02-01

    In accordance with the one-step synthesis, in this paper, we synthesized 510, 550 and 630 nm three emission peaks CdSe/ZnS core-shell quantum dots with high stability and high quantum yield whose quantum yield were 82%, 98% and 97%. We used the quantum dot material to replace the phosphor material, and mixed QDs with the silicone uniformly, then dispersed the QDs/silicone composites onto the blue InGaN LEDs to fabricate the QDs-WLEDs. By successively adding different colors of quantum dots for the preparation of quantum dot light converting layer, We investigated that how does the ratio of the three kind of quantum dots whose peaks were 510, 550 and 630 nm effect on the properties of the white LED devices. This paper also studied the mechanism of energy conversion between different colors of quantum dots. We also utilized the mechanism that the quantum dots effect on the white spectrum and color coordinates; we got the results of the optimization of the white device and the ratio of three-color quantum dots. The results show that when the quantum dot ratio is 24:7:10, white LED devices with high stability and high efficiency can be obtained, in the current range of 20-200 mA, the range of color temperature is from 4 607 to 5 920 K, the CIE-1931 coordinates is from (0.355 1,0.348 3) to (0.323 4, 0.336 1), the color rendering index is from 77. 6 to 84. 2, and the highest power efficiency of the devices achieves to 31.69 lm · W⁻¹ @ 20 mA. In addition, in order to further investigate the reason of stable device performance, We studied the effects of time, temperature, UV treatment on the stability of CdSe/ZnS QDs/silicone light conversion material, the results show that the excellent stability of the devices attributes to the stability of the one-step synthesis of core-shell structure of the quantum dot material, the final optimized device is a low-power high-quality white light source and the device has good application prospects in the field of standard white

  6. Emotional arousal state influences the ability of amygdalar endocannabinoid signaling to modulate anxiety.

    Science.gov (United States)

    Morena, Maria; Leitl, Kira D; Vecchiarelli, Haley A; Gray, J Megan; Campolongo, Patrizia; Hill, Matthew N

    2016-12-01

    Systemic activation of cannabinoid receptors often induces biphasic effects on emotional memory and anxiety depending on the levels of emotional arousal associated to the experimental context. The basolateral nucleus of the amygdala (BLA) represents a crucial structure for the ability of endocannabinoid (eCB) signaling to modulate emotional behaviour, and receives dense projections from brainstem arousal system nuclei. We examined whether changes in emotional arousal state would influence the ability of acute eCB manipulations within the BLA to modulate anxiety. Rats were tested in an elevated plus maze (EPM) under low or high arousal conditions. The low emotional arousal group was extensively handled and habituated to the experimental room and tested under red light condition, the high emotional arousal group was not handled or habituated and tested under high light condition. We examined amygdalar eCB anandamide (AEA) and 2-arachidonoylglycerol (2-AG) levels immediately after the EPM and the effects of intra-BLA administration of the AEA hydrolysis inhibitor URB597 or the 2-AG hydrolysis inhibitor KML29 on anxiety behaviour. The modulation of anxiety-like behaviour by eCBs in the BLA was strictly dependent on the environmental-associated emotional arousal. Pharmacologically-induced elevations of AEA or 2-AG in the BLA decreased anxiety under conditions of low emotional arousal. Conversely, when the level of emotional arousal increased, local eCB manipulation was ineffective in the modulation of the emotional arousal-induced anxiety response. These findings suggest that, depending on the emotional arousal state, eCB system is differentially activated to regulate the anxiety response in the amygdala and help to understand the state-dependency of many interventions on anxiety. Copyright © 2016. Published by Elsevier Ltd.

  7. Depth-specific optogenetic control in vivo with a scalable, high-density μLED neural probe

    Science.gov (United States)

    Scharf, Robert; Tsunematsu, Tomomi; McAlinden, Niall; Dawson, Martin D.; Sakata, Shuzo; Mathieson, Keith

    2016-06-01

    Controlling neural circuits is a powerful approach to uncover a causal link between neural activity and behaviour. Optogenetics has been widely adopted by the neuroscience community as it offers cell-type-specific perturbation with millisecond precision. However, these studies require light delivery in complex patterns with cellular-scale resolution, while covering a large volume of tissue at depth in vivo. Here we describe a novel high-density silicon-based microscale light-emitting diode (μLED) array, consisting of up to ninety-six 25 μm-diameter μLEDs emitting at a wavelength of 450 nm with a peak irradiance of 400 mW/mm2. A width of 100 μm, tapering to a 1 μm point, and a 40 μm thickness help minimise tissue damage during insertion. Thermal properties permit a set of optogenetic operating regimes, with ~0.5 °C average temperature increase. We demonstrate depth-dependent activation of mouse neocortical neurons in vivo, offering an inexpensive novel tool for the precise manipulation of neural activity.

  8. Nurse led telephone assessment of expanded disability status scale assessment in MS patients at high levels of disability.

    Science.gov (United States)

    Huda, S; Cavey, A; Izat, A; Mattison, P; Boggild, M; Palace, J

    2016-03-15

    In clinical trials drop out bias reduces the validity of results. This is a particular problem in long-term multiple sclerosis (MS) studies, particularly when patients become progressively disabled and have increasing difficulty attending assessment clinics. To assess the validity of nurse led telephone assessment of Expanded Disability Status Scale (TEDSS) in MS patients with EDSS scores >6.0. We performed a multi-centre, single blind trial to assess nurse derived TEDSS against physician face-to-face EDSS scores derived from neurological examination (FEDSS) in patients with clinically definite MS and EDSS >6.0. Ninety patients (n=15 primary progressive MS, n=74 secondary progressive MS, n=1 relapsing remitting MS) had a mean baseline FEDSS of 7.5. TEDSS correlated with FEDSS (r=0.76, pEDSS points, and within 1 EDSS point were 0.25, 0.86, and 1.0 respectively. Intra-class correlation between the scoring systems was 0.88, representing a high level of agreement. Nurse-led telephone assessment of EDSS gives good agreement with physician derived face-to-face EDSS in MS patients with higher disability scores. This may be a valuable tool to improve clinical follow-up in routine clinical practice and improve patient retention in long-term outcome studies. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Effects of cyproterone acetate on sexual arousal patterns of pedophiles.

    Science.gov (United States)

    Bradford, J M; Pawlak, A

    1993-12-01

    The antiandrogen treatment of sexual offenders has been shown to reduce the recidivism rate. The mechanism of action has been assumed to be through asexualization with its secondary effects on sexual behavior. This study shows that the mechanism may be more complex and may involve a differential effect on sexual arousal patterns. Treatment responses may differ in high and low plasma testosterone groups.

  10. Low-arousal speech noise improves performance in N-back task: an ERP study.

    Directory of Open Access Journals (Sweden)

    Longzhu Han

    Full Text Available The relationship between noise and human performance is a crucial topic in ergonomic research. However, the brain dynamics of the emotional arousal effects of background noises are still unclear. The current study employed meaningless speech noises in the n-back working memory task to explore the changes of event-related potentials (ERPs elicited by the noises with low arousal level vs. high arousal level. We found that the memory performance in low arousal condition were improved compared with the silent and the high arousal conditions; participants responded more quickly and had larger P2 and P3 amplitudes in low arousal condition while the performance and ERP components showed no significant difference between high arousal and silent conditions. These findings suggested that the emotional arousal dimension of background noises had a significant influence on human working memory performance, and that this effect was independent of the acoustic characteristics of noises (e.g., intensity and the meaning of speech materials. The current findings improve our understanding of background noise effects on human performance and lay the ground for the investigation of patients with attention deficits.

  11. Economic feasibility of replacing sodium vapor and high pressure mercury vapor bulbs with LEDs for street lighting

    Directory of Open Access Journals (Sweden)

    Olusola Olorunfemi Bamisile

    2016-01-01

    Full Text Available The main aim of this article is to examine the feasibility of an energy audit program. LEDs are used to replace the sodium vapor lamps and high-pressured mercury vapor lamps that are currently used for the street lighting system in the Turkish Republic of Northern Cyprus. 44% of the fossil fuels imported into the Turkish Republic of Northern Cyprus is used for electricity generation, which makes the reduction in the consumption of electicity very important. This project will save as much as 36,880,410 kWh on site annually and 111,758,818 kWh from the source. The economic, environmental, and fossil fuels savings of this project are also evaluated.

  12. Effect of reduced exposure times on the cytotoxicity of resin luting cements cured by high-power led

    Directory of Open Access Journals (Sweden)

    Gulfem Ergun

    2011-06-01

    Full Text Available OBJECTIVE: Applications of resin luting agents and high-power light-emitting diodes (LED light-curing units (LCUs have increased considerably over the last few years. However, it is not clear whether the effect of reduced exposure time on cytotoxicity of such products have adequate biocompatibility to meet clinical success. This study aimed at assessing the effect of reduced curing time of five resin luting cements (RLCs polymerized by high-power LED curing unit on the viability of a cell of L-929 fibroblast cells. MATERIAL AND METHODS: Disc-shaped samples were prepared in polytetrafluoroethylene moulds with cylindrical cavities. The samples were irradiated from the top through the ceramic discs and acetate strips using LED LCU for 20 s (50% of the manufacturer's recommended exposure time and 40 s (100% exposure time. After curing, the samples were transferred into a culture medium for 24 h. The eluates were obtained and pipetted onto L-929 fibroblast cultures (3x10(4 per well and incubated for evaluating after 24 h. Measurements were performed by dimethylthiazol diphenyltetrazolium assay. Statistical significance was determined by two-way ANOVA and two independent samples were compared by t-test. RESULTS: Results showed that eluates of most of the materials polymerized for 20 s (except Rely X Unicem and Illusion reduced to a higher extent cell viability compared to samples of the same materials polymerized for 40 s. Illusion exhibited the least cytotoxicity for 20 s exposure time compared to the control (culture without samples followed by Rely X Unicem and Rely X ARC (90.81%, 88.90%, and 83.11%, respectively. For Rely X ARC, Duolink and Lute-It 40 s exposure time was better (t=-1.262 p=0,276; t=-9.399 p=0.001; and t=-20.418 p<0.001, respectively. CONCLUSION: The results of this study suggest that reduction of curing time significantly enhances the cytotoxicity of the studied resin cement materials, therefore compromising their clinical

  13. Upbeat and happy: arousal as an important factor in studying attention.

    Science.gov (United States)

    McConnell, Meghan M; Shore, David I

    2011-11-01

    The present study examined the effects of music-induced mood changes on different components of visual attention. Affective valence (positive vs. negative) and arousal (high vs. low) were manipulated by having participants listen to one of four versions of a Mozart Sonata that varied in mode (major or minor) and tempo (fast or slow). Attention was measured in three domains-alerting, orienting, and executive control. Affective valence and arousal had an effect on executive control, but not on alerting or orienting. Individuals who experienced positive valence had less efficient control over their responses than those who experienced negative valence, but only when arousal levels were high. Positive and negative valence did not influence executive control measures when arousal levels were low. These findings demonstrate that affective valence and arousal interact with one another to influence the processing of items in visual attention.

  14. HIGH-SPEED BICHROMATIC INSPECTION OF WHEAT KERNELS FOR MOLD AND COLOR CLASS USING HIGH-POWER PULSED LEDS

    Science.gov (United States)

    High-speed optical sorting of seeds in commercial processing is routinely practiced for removal of discolored seeds, seeds from volunteer plants, and non-seed objects. Sorters are conventionally based on monochromatic or bichromatic light from broad wavebands in the visible and near-infrared region...

  15. Memory recall in arousing situations - an emotional von Restorff effect?

    Science.gov (United States)

    Wiswede, Daniel; Rüsseler, Jascha; Hasselbach, Simone; Münte, Thomas F

    2006-07-24

    Previous research has demonstrated a relationship between memory recall and P300 amplitude in list learning tasks, but the variables mediating this P300-recall relationship are not well understood. In the present study, subjects were required to recall items from lists consisting of 12 words, which were presented in front of pictures taken from the IAPS collection. One word per list is made distinct either by font color or by a highly arousing background IAPS picture. This isolation procedure was first used by von Restorff. Brain potentials were recorded during list presentation. Recall performance was enhanced for color but not for emotional isolates. Event-related brain potentials (ERP) showed a more positive P300-component for recalled non-isolated words and color-isolated words, compared to the respective non-remembered words, but not for words isolated by arousing background. Our findings indicate that it is crucial to take emotional mediator variables into account, when using the P300 to predict later recall. Highly arousing environments might force the cognitive system to interrupt rehearsal processes in working memory, which might benefit transfer into other, more stable memory systems. The impact of attention-capturing properties of arousing background stimuli is also discussed.

  16. A computerized algorithm for arousal detection in healthy adults and patients with Parkinson disease

    DEFF Research Database (Denmark)

    Sørensen, Gertrud Laura; Jennum, Poul; Kempfner, Jacob

    2012-01-01

    Arousals occur from all sleep stages and can be identified as abrupt electroencephalogram (EEG) and electromyogram (EMG) changes. Manual scoring of arousals is time consuming with low interscore agreement. The aim of this study was to design an arousal detection algorithm capable of detecting...... arousals from non-rapid eye movement (REM) and REM sleep, independent of the subject's age and disease. The proposed algorithm uses features from EEG, EMG, and the manual sleep stage scoring as input to a feed-forward artificial neural network (ANN). The performance of the algorithm has been assessed using...... compared with those of previously presented arousal detection algorithms and especially compared with the high interscore variability of manual scorings....

  17. Roles of temperamental arousal and gender-segregated play in young children's social adjustment.

    Science.gov (United States)

    Fabes, R A; Shepard, S A; Guthrie, I K; Martin, C L

    1997-07-01

    The hypothesis that gender differences in children's adjustment is partially influenced by differences in temperament and interactions with same-sex peers was examined. Fifty-seven predominantly White, middle-class preschoolers (29 boys and 28 girls, M age = 54.5 months) participated. Measures were taken of children's arousability, problem behaviors, and tendencies to play with same-sex peers. A semester later, children's peer status was assessed. Analyses revealed that arousability and same-sex peer play interacted to predict problem behaviors. For boys high in arousability, play with same-sex peers increased problem behaviors. In contrast, arousable girls who played with other girls were relatively unlikely to show problem behaviors. Moreover, the interaction of arousability and same-sex peer play predicted boys' (but not girls') peer status, and this relation was partially mediated by problem behaviors. The role of gender-related processes is discussed.

  18. Large area LED package

    Science.gov (United States)

    Goullon, L.; Jordan, R.; Braun, T.; Bauer, J.; Becker, F.; Hutter, M.; Schneider-Ramelow, M.; Lang, K.-D.

    2015-03-01

    Solid state lighting using LED-dies is a rapidly growing market. LED-dies with the needed increasing luminous flux per chip area produce a lot of heat. Therefore an appropriate thermal management is required for general lighting with LEDdies. One way to avoid overheating and shorter lifetime is the use of many small LED-dies on a large area heat sink (down to 70 μm edge length), so that heat can spread into a large area while at the same time light also appears on a larger area. The handling with such small LED-dies is very difficult because they are too small to be picked with common equipment. Therefore a new concept called collective transfer bonding using a temporary carrier chip was developed. A further benefit of this new technology is the high precision assembly as well as the plane parallel assembly of the LED-dies which is necessary for wire bonding. It has been shown that hundred functional LED-dies were transferred and soldered at the same time. After the assembly a cost effective established PCB-technology was applied to produce a large-area light source consisting of many small LED-dies and electrically connected on a PCB-substrate. The top contacts of the LED-dies were realized by laminating an adhesive copper sheet followed by LDI structuring as known from PCB-via-technology. This assembly can be completed by adding converting and light forming optical elements. In summary two technologies based on standard SMD and PCB technology have been developed for panel level LED packaging up to 610x 457 mm2 area size.

  19. Ammonium hydroxide modulated synthesis of high-quality fluorescent carbon dots for white LEDs with excellent color rendering properties

    Science.gov (United States)

    Wang, Shengda; Zhu, Zhifeng; Chang, Yajing; Wang, Hui; Yuan, Nan; Li, Guopeng; Yu, Dabin; Jiang, Yang

    2016-07-01

    A novel type of aqueous fluorescent carbon dot (CD) was synthesized using citric acid as the only carbon source via an ammonium hydroxide modulated method, providing a blue color gamut. The amino group is considered to be the key factor in the high fluorescence of CDs and a model is established to investigate the mechanism of fluorescence. In addition, white light-emitting diodes (WLEDs) are fabricated by utilizing the prepared CDs and rare earth luminescent materials (SrSi2O2N2:Eu and Sr2Si5N8:Eu) as color conversion layers and UV-LED chips as the excitation light source. The WLEDs produce bright white light with attractive color rendering properties including a color rendering index of up to 95.1, a CIE coordinate of (0.33, 0.37), and a T c of 5447 K under a 100 mA driven current, indicating that the CDs are promising in the field of optoelectronic devices.

  20. Large-scale SiO2 photonic crystal for high efficiency GaN LEDs by nanospherical-lens lithography

    Science.gov (United States)

    Wu, Kui; Wei, Tong-Bo; Lan, Ding; Zheng, Hai-Yang; Wang, Jun-Xi; Luo, Yi; Li, Jin-Min

    2014-02-01

    Wafer-scale SiO2 photonic crystal (PhC) patterns (SiO2 air-hole PhC, SiO2-pillar PhC) on indium tin oxide (ITO) layer of GaN-based light-emitting diode (LED) are fabricated via novel nanospherical-lens lithography. Nanoscale polystyrene spheres are self-assembled into a hexagonal closed-packed monolayer array acting as convex lens for exposure using conventional lithography instrument. The light output power is enhanced by as great as 40.5% and 61% over those of as-grown LEDs, for SiO2-hole PhC and SiO2-pillar PhC LEDs, respectively. No degradation to LED electrical properties is found due to the fact that SiO2 PhC structures are fabricated on ITO current spreading electrode. For SiO2-pillar PhC LEDs, which have the largest light output power in all LEDs, no dry etching, which would introduce etching damage, was involved. Our method is demonstrated to be a simple, low cost, and high-yield technique for fabricating the PhC LEDs. Furthermore, the finite difference time domain simulation is also performed to further reveal the emission characteristics of LEDs with PhC structures.

  1. Effects of Voice on Emotional Arousal

    Directory of Open Access Journals (Sweden)

    Psyche eLoui

    2013-10-01

    Full Text Available Music is a powerful medium capable of eliciting a broad range of emotions. Although the relationship between language and music is well documented, relatively little is known about the effects of lyrics and the voice on the emotional processing of music and on listeners’ preferences. In the present study, we investigated the effects of vocals in music on participants’ perceived valence and arousal in songs. Participants (N = 50 made valence and arousal ratings for familiar songs that were presented with and without the voice. We observed robust effects of vocal content on perceived arousal. Furthermore, we found that the effect of the voice on enhancing arousal ratings is independent of familiarity of the song and differs across genders and age: females were more influenced by vocals than males; furthermore these gender effects were enhanced among older adults. Results highlight the effects of gender and aging in emotion perception and are discussed in terms of the social roles of music.

  2. Arousal, mood, and the Mozart effect.

    Science.gov (United States)

    Thompson, W F; Schellenberg, E G; Husain, G

    2001-05-01

    The "Mozart effect" refers to claims that people perform better on tests of spatial abilities after listening to music composed by Mozart. We examined whether the Mozart effect is a consequence of between-condition differences in arousal and mood. Participants completed a test of spatial abilities after listening to music or sitting in silence. The music was a Mozart sonata (a pleasant and energetic piece) for some participants and an Albinoni adagio (a slow, sad piece) for others. We also measured enjoyment, arousal, and mood. Performance on tbe spatial task was better following the music than the silence condition but only for participants who heard Mozart. The two music selections also induced differential responding on the enjoyment, arousal and mood measures. Moreover, when such differences were held constant by statistical means, the Mozart effect disappeared. These findings provide compelling evidence that the Mozart effect is an artifact of arousal and mood.

  3. Optimal spectra of the phosphor-coated white LEDs with excellent color rendering property and high luminous efficacy of radiation.

    Science.gov (United States)

    He, Guoxing; Yan, Huafeng

    2011-01-31

    A model for spectra of the phosphor-coated white LED (p-W LED) with a blue chip, a red chip, and green and yellow phosphors is presented. The optimal spectra of p-W LEDs with correlated color temperatures (CCTs) of 2700-6500 K have been obtained with a nonlinear program for maximizing luminous efficacy of radiation (LER) under conditions of both color-rendering indices (CRIs) and special CRIs of R9 strong red above 98. The simulation results show that p-W LEDs with one InGaN blue (450 nm) chip, one AlGaInP red (634 nm) chip, and green (507 nm) and yellow (580 nm) silicate phosphors can realize white lights with CRIs of about 98 and special CRIs of R9 for strong red above 98. The average of the special CRIs R9 to R12 for the four saturated colors (red, yellow, green, and blue) is above 95. R13 for the skin of women's faces at about 100, as well as LERs above 296 lm/W at CCTs of 2700-6500 K. LERs of excellent CRI p-W LEDs with one InGaN blue chip, one AlGaInP red chip, and green and yellow silicate phosphors increased by 19-49% when compared with that of excellent CRI p-W LEDs with one InGaN blue chip and green and yellow silicate phosphors, as well as red nitride phosphor.

  4. Personality modulates the effects of emotional arousal and valence on brain activation.

    Science.gov (United States)

    Kehoe, Elizabeth G; Toomey, John M; Balsters, Joshua H; Bokde, Arun L W

    2012-10-01

    The influence of personality on the neural correlates of emotional processing is still not well characterized. We investigated the relationship between extraversion and neuroticism and emotional perception using functional magnetic resonance imaging (fMRI) in a group of 23 young, healthy women. Using a parametric modulation approach, we examined how the blood oxygenation level dependent (BOLD) signal varied with the participants' ratings of arousal and valence, and whether levels of extraversion and neuroticism were related to these modulations. In particular, we wished to test Eysenck's biological theory of personality, which links high extraversion to lower levels of reticulothalamic-cortical arousal, and neuroticism to increased reactivity of the limbic system and stronger reactions to emotional arousal. Individuals high in neuroticism demonstrated reduced sustained activation in the orbitofrontal cortex (OFC) and attenuated valence processing in the right temporal lobe while viewing emotional images, but an increased BOLD response to emotional arousal in the right medial prefrontal cortex (mPFC). These results support Eysenck's theory, as well as our hypothesis that high levels of neuroticism are associated with attenuated reward processing. Extraversion was inversely related to arousal processing in the right cerebellum, but positively associated with arousal processing in the right insula, indicating that the relationship between extraversion and arousal is not as simple as that proposed by Eysenck.

  5. Mood and the DRM paradigm: An investigation of the effects of valence and arousal on false memory.

    Science.gov (United States)

    Van Damme, Ilse

    2013-06-01

    Recent studies regarding the effect of mood on the DRM (Deese-Roediger-McDermott) illusion have not been able to clearly establish yet whether valence or arousal is most critical in determining susceptibility to false memories, nor what the underlying processes are. In three experiments, both the valence and the level of arousal of participants' mood were manipulated. Six conditions were used: positive mood with high/low arousal, negative mood with high/low arousal, neutral mood, and a control condition. Memory was tested by means of immediate and delayed recognition and immediate free recall. The mood induction procedure was effective. For recognition memory, there was an effect of arousal on the endorsement of critical lures. Low-arousal moods elicited more false recognition than high-arousal moods, regardless of valence. Based on signal detection analyses, the effect was attributed to more liberal response criteria with low arousal, in combination with a tendency towards improved item-specific memory with high arousal.

  6. Driving Down HB-LED Costs. Implementation of Process Simulation Tools and Temperature Control Methods of High Yield MOCVD Growth

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, William [Veeco Process Equipment, Inc., Plainview, NY (United States)

    2012-04-30

    The overall objective of this multi-faceted program is to develop epitaxial growth systems that meet a goal of 75% (4X) cost reduction in the epitaxy phase of HB-LED manufacture. A 75% reduction in yielded epitaxy cost is necessary in order to achieve the cost goals for widespread penetration of HB-LED's into back-lighting units (BLU) for LCD panels and ultimately for solid-state lighting (SSL). To do this, the program will address significant improvements in overall equipment Cost of Ownership, or CoO. CoO is a model that includes all costs associated with the epitaxy portion of production. These aspects include cost of yield, capital cost, operational costs, and maintenance costs. We divide the program into three phases where later phases will incorporate the gains of prior phases. Phase one activities are enabling technologies. In collaboration with Sandia National Laboratories we develop a Fluent-compatible chemistry predictive model and a set of mid-infrared and near-ultraviolet pyrometer monitoring tools. Where previously the modeling of the reactor dynamics were studied within FLUENT alone, here, FLUENT and Chemkin are integrated into a comprehensive model of fluid dynamics and the most advanced transport equations developed for Chemkin. Specifically, the Chemkin model offered the key reaction terms for gas-phase nucleation, a key consideration in the optimization of the MOCVD process. This new predictive model is used to design new MOCVD reactors with optimized growth conditions and the newly developed pyrometers are used monitor and control the MOCVD process temperature to within 0.5°C run-to-run and within each wafer. This portion of the grant is in collaboration with partners at Sandia National Laboratories. Phase two activities are continuous improvement projects which extend the current reactor platform along the lines of improved operational efficiency, improved systems control for throughput, and carrier modifications for increased yield

  7. Graphene oxide modified ZnO nanorods hybrid with high reusable photocatalytic activity under UV-LED irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Kai, E-mail: daikai940@chnu.edu.cn [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China); Lu, Luhua, E-mail: lhlu@whut.edu.cn [State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Liang, Changhao; Dai, Jianming [Key Laboratory of Materials Physics and Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Zhu, Guangping; Liu, Zhongliang; Liu, Qinzhuang; Zhang, Yongxing [College of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000 (China)

    2014-02-14

    In this work, graphene oxide/zinc oxide (GO/ZnO) hybrid was prepared through a facile hydrothermal process. Transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectra and N{sub 2} adsorption and desorption isotherms were used to investigate the morphology, crystal structure, optical properties and specific surface area of GO/ZnO hybrid. It was shown that the well-dispersed ZnO nanorods were deposited on GO homogeneously. Photocatalytic properties of GO/ZnO nanorods hybrid were evaluated under 375 nm light-emitting diode light irradiation for photodegradation of methylene blue (MB). The synergic effect between GO and ZnO was found to lead to an improved photo-generated carrier separation. An optimal GO content has been determined to be 3 wt%, and corresponding the apparent pseudo-first-order rate constant k{sub app} is 0.0248 min{sup −1}, 4.3 times and 2.5 times more than that of pure ZnO nanorods and commercial P25 photocatalyst, respectively. Moreover, the cyclic photocatalytic test indicated that GO/ZnO hybrid can be reused for degradation of MB, suggesting the possible application of GO/ZnO hybrid as excellent candidate for water treatment. - Highlights: • GO/ZnO hybrid was successfully synthesized by hydrothermal process. • GO/ZnO hybrid showed high photocatalytic activity with irradiation of LED light. • Effective photo-electrons separation and fast transportation. • Excellent recycled performance was achieved by GO/ZnO hybrid.

  8. The interaction of arousal and valence in affective priming: behavioral and electrophysiological evidence.

    Science.gov (United States)

    Zhang, Qin; Kong, Lingyue; Jiang, Yang

    2012-09-20

    The affective priming paradigm has been studied extensively and applied in many fields during the past two decades. Most research thus far has focused on the valence dimension. Whether emotional arousal influences affective priming remains poorly understood. The present study demonstrates how arousal impacts evaluation of affective words using reaction time and event-related potential (ERP) measures. Eighteen younger subjects evaluated pleasantness of target words after seeing affective pictures as primes. The participants' responses were faster and/or more accurate for valence-congruent trials than for incongruent trials, particularly with high-arousal stimuli. An ERP affective priming effect (N400) also occurred mainly in high-arousing stimulus pairs. In addition, whereas valence congruency influenced both the N400 and the LPP, arousal congruency influenced only the LPP, suggesting that arousal congruency mainly modulates post-semantic processes, but valence congruency effects begin with semantic processes. Overall, our current findings indicate that the arousal level of visual images impacts both behavioral and ERP effects of affective priming.

  9. Effects of melatonin and green-wavelength LED light on the physiological stress and immunity of goldfish, Carassius auratus, exposed to high water temperature.

    Science.gov (United States)

    Jung, Seo Jin; Kim, Na Na; Choi, Young Jae; Choi, Ji Yong; Choi, Young-Ung; Heo, Youn Seong; Choi, Cheol Young

    2016-10-01

    This study investigated the effects of increasing water temperature (22-30 °C) on the physiological stress response and immunity of goldfish, Carassius auratus, and the ability of green light-emitting diode (LED) irradiation or melatonin injections to mitigate this temperature-induced stress. To evaluate the effects of either green-wavelength LED light or melatonin on stress in goldfish, we measured plasma triiodothyronine (T3), thyroxine (T4), and thyroid hormone receptor (TR) mRNA expression; plasma cortisol and glucose; and immunoglobulin M (IgM) and lysozyme mRNA expression. The thyroid hormone activities, TR mRNA expression, and plasma cortisol and glucose were higher in goldfish exposed to high-temperature water, but were lower after exposure to melatonin or green-wavelength LED light. Lysozyme mRNA expression and plasma IgM activity and protein expression were lower after exposure to high water temperatures and higher after melatonin or green-wavelength LED light treatments. Therefore, high water temperature induced stress and decreased immunity; however, green-wavelength LED light and melatonin treatments mitigated the effects of stress and enhanced immunity. The benefits of melatonin decreased with time, whereas those of green-wavelength LED treatment did not.

  10. High efficiency GaN-based LEDs using plasma selective treatment of p-GaN surface

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Bae; Naoi, Yoshiki; Sakai, Shiro [Department of Electrical and Electronic Engineering, University of Tokushima, 2-1 Minami-josanjima, Tokushima 770-8506 (Japan); Takaki, Ryohei; Sato, Hisao [Nitride Semiconductor Co., Ltd., 115-7 Itayajima, Akinokami, Seto-cho, Naruto, Tokushima 771-0360 (Japan)

    2003-11-01

    We have studied a new method of increasing the extraction efficiency of a GaN-based light-emitting diode (LED) using a plasma surface treatment. In this method, prior to the evaporation of a semitransparent p-metal, the surface of a p-GaN located beneath a p-pad is selectively exposed to a nitrogen plasma in a reactive ion etching (RIE) chamber. The electrical characteristics of the plasma treated p-GaN remarkably changes its resistivity into semi-insulator without any parasitic damage. Since the LEDs with a new method have no light absorption in a p-pad region, a higher optical power can be extracted compared to a conventional LEDs without plasma selective treatment on the p-GaN surface. (copyright 2003 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Pupil-Linked Arousal Determines Variability in Perceptual Decision Making: e1003854

    National Research Council Canada - National Science Library

    Peter R Murphy; Joachim Vandekerckhove; Sander Nieuwenhuis

    2014-01-01

    .... We measured pupil size, a highly sensitive index of arousal, while human subjects performed a motion-discrimination task, and decomposed task behavior into latent decision making parameters using...

  12. The effect of exercise-induced arousal on chosen tempi for familiar melodies

    National Research Council Canada - National Science Library

    Jakubowski, Kelly; Halpern, Andrea R; Grierson, Mick; Stewart, Lauren

    2015-01-01

    .... However, it is unknown whether arousal influences the mental representation of tempo (speed) for highly familiar and complex stimuli, such as well-known melodies, that have long-term representations in memory...

  13. Music, perceived arousal, and intensity: psychophysiological reactions to Chopin's "Tristesse".

    Science.gov (United States)

    Mikutta, Christian Alexander; Schwab, Simon; Niederhauser, Sandra; Wuermle, Othmar; Strik, Werner; Altorfer, Andreas

    2013-09-01

    The present study investigates the relation of perceived arousal (continuous self-rating), autonomic nervous system activity (heart rate, heart rate variability) and musical characteristics (sound intensity, musical rhythm) upon listening to a complex musical piece. Twenty amateur musicians listened to two performances of Chopin's "Tristesse" with different rhythmic shapes. Besides conventional statistical methods for analyzing psychophysiological reactions (heart rate, respiration rate) and musical variables, semblance analysis was used. Perceived arousal correlated strongly with sound intensity; heart rate showed only a partial response to changes in sound intensity. Larger changes in heart rate were caused by the version with more rhythmic tension. The low-/high-frequency ratio of heart rate variability increased--whereas the high frequency component decreased--during music listening. We conclude that autonomic nervous system activity can be modulated not only by sound intensity but also by the interpreter's use of rhythmic tension. Semblance analysis enables us to track the subtle correlations between musical and physiological variables.

  14. The amplitude and phase precision of 40 Hz auditory steady-state response depend on the level of arousal

    DEFF Research Database (Denmark)

    Griskova, Inga; Morup, Morten; Parnas, Josef;

    2007-01-01

    by the level of arousal, but the findings are somewhat controversial. Generally, ASSR is diminished in sleep but it may be increased in drowsiness. Besides, ASSR reduction has been observed in schizophrenia. However, schizophrenic patients are known to have a disturbance of arousal level, what makes......-negative multi-way factorization (NMWF) (Morup et al. in J Neurosci Methods 161:361-368, 2007). The estimates of these measures were subjected to statistical analysis. The amplitude and phase precision of the ASSR were significantly larger during the low arousal state compared to the high arousal condition...

  15. Beyond intensity: Spectral features effectively predict music-induced subjective arousal.

    Science.gov (United States)

    Gingras, Bruno; Marin, Manuela M; Fitch, W Tecumseh

    2014-01-01

    Emotions in music are conveyed by a variety of acoustic cues. Notably, the positive association between sound intensity and arousal has particular biological relevance. However, although amplitude normalization is a common procedure used to control for intensity in music psychology research, direct comparisons between emotional ratings of original and amplitude-normalized musical excerpts are lacking. In this study, 30 nonmusicians retrospectively rated the subjective arousal and pleasantness induced by 84 six-second classical music excerpts, and an additional 30 nonmusicians rated the same excerpts normalized for amplitude. Following the cue-redundancy and Brunswik lens models of acoustic communication, we hypothesized that arousal and pleasantness ratings would be similar for both versions of the excerpts, and that arousal could be predicted effectively by other acoustic cues besides intensity. Although the difference in mean arousal and pleasantness ratings between original and amplitude-normalized excerpts correlated significantly with the amplitude adjustment, ratings for both sets of excerpts were highly correlated and shared a similar range of values, thus validating the use of amplitude normalization in music emotion research. Two acoustic parameters, spectral flux and spectral entropy, accounted for 65% of the variance in arousal ratings for both sets, indicating that spectral features can effectively predict arousal. Additionally, we confirmed that amplitude-normalized excerpts were adequately matched for loudness. Overall, the results corroborate our hypotheses and support the cue-redundancy and Brunswik lens models.

  16. Dissociable modulation of overt visual attention in valence and arousal revealed by topology of scan path.

    Directory of Open Access Journals (Sweden)

    Jianguang Ni

    Full Text Available Emotional stimuli have evolutionary significance for the survival of organisms; therefore, they are attention-grabbing and are processed preferentially. The neural underpinnings of two principle emotional dimensions in affective space, valence (degree of pleasantness and arousal (intensity of evoked emotion, have been shown to be dissociable in the olfactory, gustatory and memory systems. However, the separable roles of valence and arousal in scene perception are poorly understood. In this study, we asked how these two emotional dimensions modulate overt visual attention. Twenty-two healthy volunteers freely viewed images from the International Affective Picture System (IAPS that were graded for affective levels of valence and arousal (high, medium, and low. Subjects' heads were immobilized and eye movements were recorded by camera to track overt shifts of visual attention. Algebraic graph-based approaches were introduced to model scan paths as weighted undirected path graphs, generating global topology metrics that characterize the algebraic connectivity of scan paths. Our data suggest that human subjects show different scanning patterns to stimuli with different affective ratings. Valence salient stimuli (with neutral arousal elicited faster and larger shifts of attention, while arousal salient stimuli (with neutral valence elicited local scanning, dense attention allocation and deep processing. Furthermore, our model revealed that the modulatory effect of valence was linearly related to the valence level, whereas the relation between the modulatory effect and the level of arousal was nonlinear. Hence, visual attention seems to be modulated by mechanisms that are separate for valence and arousal.

  17. Variability in emotional/behavioral problems in boys with oppositional defiant disorder or conduct disorder: the role of arousal.

    Science.gov (United States)

    Schoorl, Jantiene; Van Rijn, Sophie; De Wied, Minet; Van Goozen, Stephanie H M; Swaab, Hanna

    2016-08-01

    It is often reported that children with oppositional defiant disorder (ODD) or conduct disorder (CD) are under-aroused. However, the evidence is mixed, with some children with ODD/CD displaying high arousal. This has led to the hypothesis that different profiles of arousal dysfunction may exist within children with ODD/CD. This knowledge could explain variability within children with ODD/CD, both in terms of specific types of aggression as well as comorbid symptoms (e.g., other emotional/behavioral problems). We measured heart rate variability (HRV), heart rate (HR) and skin conductance level (SCL) during rest and stress, and obtained parent and teacher reports of aggression, anxiety, attention problems and autism traits in a sample of 66 ODD/CD and 36 non-clinical boys (aged 8-12 years). The ODD/CD group scored significantly higher on aggression, anxiety, attention problems and autism traits than the controls; boys with ODD/CD also had higher resting HRs than controls, but HR stress, HRV and SCL did not differ. Hierarchical regressions showed different physiological profiles in subgroups of boys with ODD/CD based on their type of aggression; a pattern of high baseline HR and SCL, but low stress HRV was related to reactive aggression, whereas the opposite physiological pattern (low HR, low stress SCL, high stress HRV) was related to proactive aggression. Furthermore, high stress SCL was related to anxiety symptoms, whereas low stress SCL was related to attention problems. These findings are important because they indicate heterogeneity within boys with ODD/CD and highlight the importance of using physiology to differentiate boys with different ODD/CD subtypes.

  18. Denali Geographic 2012 : A University led scientific field experience for High School students at the Alaska Summer Research Academy

    Science.gov (United States)

    Shipman, J. S.; Webley, P. W.; Burke, S.; Chebul, E.; Dempsey, A.; Hastings, H.; Terry, R.; Drake, J.

    2012-12-01

    The Alaska Summer Research Academy (ASRA) annually provides the opportunity for ~150 exceptional high school students to engage in scientific exploration at the university level. In July 2012, University of Alaska Fairbanks instructors led a two-week long ASRA module, called 'Denali Geographic', where eight student participants from across the USA and Canada learned how to observe changes in the natural world and design their own experiments for a field expedition to Denali National Park and Preserve, with assistance from the National Park Service. Each student designed an experiment/observational project prior to the expedition to investigate changes across the expanse of the park. Projects included wildlife documentation; scat and track observations; soil ph and moisture with elevation and vegetation changes; wildflowers species distribution; waterborne insect populations; atmospheric pressure and temperature variations; construction of sustainable buildings to minimize human impact on the park; and park geology comparisons between outcrop and distal stream deposits. The students learned how to design experiments, purchase supplies needed to conduct the work, and select good locations in which to sample in the park. Students used equipment such as GPS to mark field locations; a range finder to determine distance from wildlife; a hygrometer for temperature and pressure; nets and sorting equipments to analyze insects; and the preparation of Plaster of Paris for creating casts of animal tracks. All observations were documented in their field notebooks and blog entries made to share their experiences. Day excursions as part of the module included Poker Flats Research Range, where students learned about the use of unmanned aerial vehicles in scientific exploration; Alaska Volcano Observatory, where students learned about volcanic hazards in Alaska and the North Pacific; Chena Hot Springs and the Ice Museum, where students learned about thermal imaging using a Forward

  19. 功率型LED封装用高分子材料的研究进展%Research Progress of Polymer Materials for High-Power LED Encapsulation

    Institute of Scientific and Technical Information of China (English)

    高南; 刘伟区; 闫振龙; 孙越; 陈海生

    2012-01-01

    With the development of high-power light emitting diode (HP-LED), the packaging material of LED has become an important key technique for LED lighting in daily life. As for high-power LED, the characteristics of high refractive index, high transmittance, high thermal conductivity, excellent UV/thermal resistance, low stress and water absorption are required. At present, the polymer materials for LED packaging mainly included epoxy resins and organosilicones, and a lot of researches about modifications of them are focused on improving the refractive index, aging resistance, thermal conductivity, water absorption and mechanical property to satisfy the demands of high-power LED packaging. Among the materials, cycloaliphatic epoxy resins and nano-composite of organosilicones have wide development prospections for high-power LED encapsulations.%随着发光二极管(LED)亮度和功率的不断提高,封装材料已成为制约LED进入照明领域的关键技术之一。对于功率型LED封装材料,要求具有高折射率、高透光率、高导热率、耐紫外、耐热老化、低应力、低吸水率等性能特点。目前LED封装用两大主要高分子材料是环氧树脂和有机硅复合材料。对这两种材料的改性主要集中在折射率、耐老化性、导热性、吸水性和力学性能等方面。脂环族环氧树脂及纳米有机硅复合材料作为高功率LED封装材料具有广阔的发展前景。

  20. Comparison of LED and conventional fluorescence microscopy for detection of acid-fast bacilli in an area with high tuberculosis incidence.

    Science.gov (United States)

    Marzouk, Manel; Ferjani, Asma; Dhaou, Mohamed; Ali, Moufida Haj; Hannachi, Naila; Boukadida, Jalel

    2013-07-01

    The objective of the study is to compare the performance of conventional fluorescence microscopy (CFM) and light-emitting diode (LED) fluorescence microscopy (FM) for detection of acid-fast bacilli (AFB) in clinical samples. We included AFB smears, stained using the auramine O method and blindly examined with both CFM and LED-FM. Culture results were used as reference for evaluating the reliability of the FM. We included 180 culture positive specimens and an equal number of culture negative specimens. Sensitivities for the CFM and LED-FM were 79.4% and 82.2%, respectively. Both microscopes had a high specificity (97.2%). The negative-positive (>1 cross) inter-reader agreement of LED-FM and CFM was excellent. Therefore, detection of scanty AFB was higher with LED-FM. Both microscopes were equivalent with respect to time required to read smears. Although it was not faster than CFM, the higher detection of scanty AFB smears combined with ease of use supports the consideration of LED microscopy by all tuberculosis diagnostic laboratories, as a replacement for conventional fluorescence microscopes.

  1. Research Update: Challenges for high-efficiency hybrid lead-halide perovskite LEDs and the path towards electrically pumped lasing

    OpenAIRE

    Guangru Li; Michael Price; Felix Deschler

    2016-01-01

    Hybrid lead-halide perovskites have emerged as promising solution-processed semiconductor materials for thin-film optoelectronics. In this review, we discuss current challenges in perovskite LED performance, using thin-film and nano-crystalline perovskite as emitter layers, and look at device performance and stability. Fabrication of electrically pumped, optical-feedback devices with hybrid lead halide perovskites as gain medium is a future challenge, initiated by the demonstration of optical...

  2. Directed attention reduces processing of emotional distracters irrespective of valence and arousal level.

    Science.gov (United States)

    Wiens, Stefan; Syrjänen, Elmeri

    2013-09-01

    Emotional stimuli tend to capture attention, and this so-called motivated attention is commonly measured using the early posterior negativity (EPN) and the late positive potential (LPP). We hypothesized that voluntary, directed attention reduces motivated attention more strongly for highly than moderately arousing pleasant or unpleasant pictures. Participants were instructed to direct their attention to either a picture at fixation or the letters flanking the picture. Pictures varied substantially in arousal and valence. When the pictures were attended to, EPN and LPP increased linearly with arousal. When the letters were attended to, these linear effects decreased in the EPN for pleasant and unpleasant pictures and in the LPP for pleasant pictures. Thus, directed attention decreases processing of emotional distracters more strongly for highly than moderately arousing pleasant and unpleasant pictures. These results are consistent with the view that directed attention decreases emotion effects on sensory gain. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  3. 一种高功率因数交流 LED 驱动电路的设计%Design of AC LED Driver Circuit with High Power Factor

    Institute of Scientific and Technical Information of China (English)

    刘生建; 马桂芳; 邱晓芬

    2016-01-01

    传统的LED驱动电路由于采用AC-DC变换器,需要大的电感和电解电容,导致LED驱动电路存在体积大、成本高、寿命短等问题,提出一种新型交流电压直接驱动的LED驱动电路。该驱动电路仅需要MOSFETs和运放等有源器件,输入电流能跟随输入电压呈正弦波形变换,以获得高功率因数和低THD。仿真和实验验证该驱动电路的电气特性。%Conventional LED drivers consist of AC -DC converters which require passive components such as high value inductors and electrolytic capacitors for their operation ,the use of such components increases the size and cost of the LED system while de-creasing the overall life time , a novel driver circuit that can directly run from AC voltage is presented .The proposed driver circuit only needs active devices like MOSFETs and op -amps for power processing ,the input current is selectively controlled to follow a sinusoidal waveform to achieve low harmonic distortion and high power factor .The efficiency of the proposed system is around 80%for a 1.5W converter with 8% total harmonic distortion and 0.97 power factor,both simulation and experimental results have been presented to verify the operation of the proposed circuit .

  4. Facile Preparation and Ultrastable Performance of Single-Component White-Light-Emitting Phosphor-in-Glass used for High-Power Warm White LEDs.

    Science.gov (United States)

    Zhang, Xuejie; Yu, Jinbo; Wang, Jing; Zhu, Chenbiao; Zhang, Jinhui; Zou, Rui; Lei, Bingfu; Liu, YingLiang; Wu, Mingmei

    2015-12-30

    Long lifetime, excellent chromatic stability, and easily obtainable white light are becoming three outstanding challenges faced by the state-of-the-art high-power white LEDs. This study explored a novel single-component white-light-emitting phosphor-in-glass (PiG) for the first time. It has a quantum efficiency of 26.2% and exhibits excellent heat-resistance and good humidity-resistance characteristics which are rarely reported in traditional phosphor slurry. A proof-of-concept warm white LEDs was fabricated by combining PiG with near-ultraviolet chip-on-board (n-UV COB). This method reported in this letter will open a new and simple approach to obtain excellent performance single-component luminescent convertor for advanced high-power white LEDs.

  5. Leader Affective Displays and Attributions of Charisma: The Role of Arousal

    OpenAIRE

    Damen, Frederic; van Knippenberg, Daan; Knippenberg, Barbara

    2007-01-01

    textabstractResearch suggests that leader displays of positive affect are conducive to attributions of charisma. We qualify and extend this conclusion by arguing that this mainly holds for displays of positive affect that are associated with high levels of arousal. Results of a scenario experiment and a survey support this hypothesis, and show that besides the transfer of positive feelings per se, it is the transfer of arousal that mediates the relationship between leader affective displays a...

  6. Affective Norms for Italian Words in Older Adults: Age Differences in Ratings of Valence, Arousal and Dominance

    Science.gov (United States)

    Fairfield, Beth; Ambrosini, Ettore; Mammarella, Nicola; Montefinese, Maria

    2017-01-01

    In line with the dimensional theory of emotional space, we developed affective norms for words rated in terms of valence, arousal and dominance in a group of older adults to complete the adaptation of the Affective Norms for English Words (ANEW) for Italian and to aid research on aging. Here, as in the original Italian ANEW database, participants evaluated valence, arousal, and dominance by means of the Self-Assessment Manikin (SAM) in a paper-and-pencil procedure. We observed high split-half reliabilities within the older sample and high correlations with the affective ratings of previous research, especially for valence, suggesting that there is large agreement among older adults within and across-languages. More importantly, we found high correlations between younger and older adults, showing that our data are generalizable across different ages. However, despite this across-ages accord, we obtained age-related differences on three affective dimensions for a great number of words. In particular, older adults rated as more arousing and more unpleasant a number of words that younger adults rated as moderately unpleasant and arousing in our previous affective norms. Moreover, older participants rated negative stimuli as more arousing and positive stimuli as less arousing than younger participants, thus leading to a less-curved distribution of ratings in the valence by arousal space. We also found more extreme ratings for older adults for the relationship between dominance and arousal: older adults gave lower dominance and higher arousal ratings for words rated by younger adults with middle dominance and arousal values. Together, these results suggest that our affective norms are reliable and can be confidently used to select words matched for the affective dimensions of valence, arousal and dominance across younger and older participants for future research in aging. PMID:28046070

  7. Research Update: Challenges for high-efficiency hybrid lead-halide perovskite LEDs and the path towards electrically pumped lasing

    Science.gov (United States)

    Li, Guangru; Price, Michael; Deschler, Felix

    2016-09-01

    Hybrid lead-halide perovskites have emerged as promising solution-processed semiconductor materials for thin-film optoelectronics. In this review, we discuss current challenges in perovskite LED performance, using thin-film and nano-crystalline perovskite as emitter layers, and look at device performance and stability. Fabrication of electrically pumped, optical-feedback devices with hybrid lead halide perovskites as gain medium is a future challenge, initiated by the demonstration of optically pumped lasing structures with low gain thresholds. We explain the material parameters affecting optical gain in perovskites and discuss the challenges towards electrically pumped perovskite lasers.

  8. Research Update: Challenges for high-efficiency hybrid lead-halide perovskite LEDs and the path towards electrically pumped lasing

    Directory of Open Access Journals (Sweden)

    Guangru Li

    2016-09-01

    Full Text Available Hybrid lead-halide perovskites have emerged as promising solution-processed semiconductor materials for thin-film optoelectronics. In this review, we discuss current challenges in perovskite LED performance, using thin-film and nano-crystalline perovskite as emitter layers, and look at device performance and stability. Fabrication of electrically pumped, optical-feedback devices with hybrid lead halide perovskites as gain medium is a future challenge, initiated by the demonstration of optically pumped lasing structures with low gain thresholds. We explain the material parameters affecting optical gain in perovskites and discuss the challenges towards electrically pumped perovskite lasers.

  9. EFFECT OF HIGH INTENSITY LED LIGHT ON THE GERMINATION AND GROWTH OF BROCCOLI SEEDLINGS (BRASSICA OLERACEA L.

    Directory of Open Access Journals (Sweden)

    Guillermo Paniagua-Pardo

    2015-11-01

    Full Text Available Dado su alto valor nutricional y los beneficios a la salud por los compuestos anticancerígenos que posee, el brócoli (Brassica oleraceaL. se ha convertido en un cultivo de importancia dentro de las hortalizas, por lo que es necesario incrementar su consumo y producción por la sociedad mexicana. Esta investigación planteó como objetivo evaluar el efecto de la luz LED de alta intensidad de distinta longitud de onda (rojo, azul y verde, en germinación y crecimiento de plántulas de brócoli, evaluando las variables velocidad de germinación (VG, porcentaje de germinación (PGF, longitud media de hipocótilo (LMH, peso fresco (PF y seco (PS de las plántulas, en busca de alternativas de iluminación para la producción en ambiente controlado. Los tiempos de exposición con luz roja, azul y verde, proveniente de LEDs de alta intensidad fueron de 12, seis y tres horas, con un complemento de tiempo para los últimos dos tratamientos con luz LED blanca. Se utilizó un diseño experimental completamente al azar, con cuatro repeticiones de 30 semillas por unidad experimental. Se obtuvieron diferencias estadísticas significativas entre los tratamientos de las variables evaluadas. Los tratamientos con luz roja presentaron los mayores valores de VG, donde el rojo por 12 horas fue el mejor con incrementos del 25% contra el control. La variable LMH en el tratamiento verde por 12 horas tuvo incremento del 39% respecto al control, convirtiéndose en el mejor. Por otro lado, en la variable PF, el mayor peso se presentó en el tratamiento verde por 12 horas con un incremento contra el control del 16%. Finalmente en la variable PS, el mayor peso se presentó en el tratamiento rojo por 12 horas con un incremento contra el control del 6%. Estos resultados mostraron que las respuestas fisiológicas producidas por la exposición a distintas longitudes de onda de luz LED de alta intensidad en semilla de brócoli variaron de acuerdo con el tiempo de exposición y

  10. Development of Active Temperature Control System for High-power LED%大功率LED有源温控系统的开发

    Institute of Scientific and Technical Information of China (English)

    刘世俊; 刘超

    2011-01-01

    Most of the power energy of high-power LEDs convert into the heat energy when it is turned on. The light intensity and life time of high-power LED will be influenced seriously if the heat energy can not be diffused efficently. Considering the actual demand of the high-power LED heat dissipation) a LED active temperature control system is presented in this paper. The LED driver is used as the refrigeration driver power supply of TEC. The temperature monitoring circuit based on the semiconductor transducer is made. The closed-loop control system is formed through PI regulator. The tested data shows that the LED active temperature control system is stable and reliable.%由于大功率LED供电时其大部分能量转化为热能,如果热量不能有效散出,将严重影响其光照亮度及其使用寿命.为了大功率LED散热的实际需要,提出并实现了一种LED有源温控系统的开发,采用热电制冷效应,使用LED驱动器本身作为制冷器的驱动电源,同时建立基于半导体传感器的温控监测电路,通过内部数字PI调节器形成一个完整的闭环控制系统,最后获得LED有源温控系统的具体配置方式,并分析测试的数据结果,展示了有源温控系统的准确性和可靠性.

  11. Memory for committing a crime: effects of arousal, proximity, and gender.

    Science.gov (United States)

    Price, Heather L; Lee, Zina; Read, J Don

    2009-01-01

    Few researchers have investigated the memories of active participants in an emotionally arousing crime. The present study used a mock crime paradigm to explore participant memories for a low, moderate, or highly arousing event. Forty-seven undergraduate participants committed a "theft" of an exam from a professor's office. Two weeks after the theft, participants completed a cognitive interview, recalled objects from the professor's office, and constructed a map of the route to and from the crime room. Arousal improved reports on a map recall task but no other recall indices. Although there was a general superiority of recall of proximal over distal details, arousal only infrequently interacted with proximity. Some support was found for proximity (spatial-temporal distinction) as a useful proxy for centrality. Future work will benefit from an examination of the overlap between definitions of centrality and proximity with more traditional stimuli.

  12. An Arousal Model of Interpersonal Intimacy

    Science.gov (United States)

    Patterson, Miles L.

    1976-01-01

    A theoretical model designed to explain and predict reactive changes in the expression of interpersonal intimacy is presented. The model basically proposes that in an interaction, sufficient changes in one person's intimacy behaviors (e.g., interpersonal distance, eye contact, touch) precipitate arousal change in the other person. (Editor)

  13. Drug Induced Arousal and Fear Appeals.

    Science.gov (United States)

    Deckner, C. William; Rogers, Ronald W.

    It is hypothesized that the drug, epinephrine, used in conjunction with a fear arousing film on the consquences of smoking would be more effective than either alone in increasing fear and negative attitudes toward smoking and, resultantly, in reducing cigarette consumption. The experimenters assigned 119 subjects to the four cells of a 2x2…

  14. New Phosphors for White LEDs

    Institute of Scientific and Technical Information of China (English)

    LIU Ru-Shi

    2004-01-01

    White light-emitting diodes (WLEDs) have matched the emission efficiency of florescent lights and will rapidly spread as light source for homes and offices in the next 5 to 10 years. WLEDs provide a light element having a semiconductor light emitting layer (blue or UV LEDs) and photoluminescence phosphors. GaN-based highly efficient blue InGaN LEDs combined with phosphors can produce white light. These solid-state LED lamps have a number of advantages over conventional incandescent bulbs and halogen lamps, such as high efficiency to convert electrical energy into light, reliability, and long operating lifetime (about 100,000 hours). For the purpose of development of high energy-efficient white light sources, we need to produce highly efficient new phosphors, which can absorb excitation energy from blue or UV LEDs and generate emissions.In this paper, we investigate the development of blue or UV LEDs by the appropriate combination of new phosphors which can lead us to obtain high brightness white light. The criteria of choosing the best phosphors, for blue (380-450 nm) and UV (360-400 nm) LEDs, strongly depends on the absorption and emission of the phosphors. Moreover, the balance light between the light emission from blue LEDs and the yellow YAG:Ce,Gd phosphor is important to obtain white light with high color temperature. The phosphors with high efficiency which can be excited by UV LEDs are important to obtain the white light with high color rendering index.

  15. New approach to color calibration of high fidelity color digital camera by using unique wide gamut color generator based on LED diodes

    Science.gov (United States)

    Kretkowski, M.; Shimodaira, Y.; Jabłoński, R.

    2008-11-01

    Development of a high accuracy color reproduction system requires certain instrumentation and reference for color calibration. Our research led to development of a high fidelity color digital camera with implemented filters that realize the color matching functions. The output signal returns XYZ values which provide absolute description of color. In order to produce XYZ output a mathematical conversion must be applied to CCD output values introducing a conversion matrix. The conversion matrix coefficients are calculated by using a color reference with known XYZ values and corresponding output signals from the CCD sensor under each filter acquisition from a certain amount of color samples. The most important feature of the camera is its ability to acquire colors from the complete theoretically visible color gamut due to implemented filters. However market available color references such as various color checkers are enclosed within HDTV gamut, which is insufficient for calibration in the whole operating color range. This led to development of a unique color reference based on LED diodes called the LED Color Generator (LED CG). It is capable of displaying colors in a wide color gamut estimated by chromaticity coordinates of 12 primary colors. The total amount of colors possible to produce is 25512. The biggest advantage is a possibility of displaying colors with desired spectral distribution (with certain approximations) due to multiple primary colors it consists. The average color difference obtained for test colors was found to be ▵E~0.78 for calibration with LED CG. The result is much better and repetitive in comparison with the Macbeth ColorCheckerTM which typically gives ▵E~1.2 and in the best case ▵E~0.83 with specially developed techniques.

  16. Neural modulation of directed forgetting by valence and arousal: An event-related potential study.

    Science.gov (United States)

    Gallant, Sara N; Dyson, Benjamin J

    2016-10-01

    Intentional forgetting benefits memory by removing no longer needed information and promoting processing of more relevant materials. This study sought to understand how the behavioural and neurophysiological representation of intentional forgetting would be impacted by emotion. We took a novel approach by examining the unique contribution of both valence and arousal on emotional directed forgetting. Participants completed an item directed forgetting task for positive, negative, and neutral words at high and lower levels of arousal while brain activity was recorded using electroencephalography (EEG). Behaviourally, recognition of to-be-remembered (TBR) and to-be-forgotten (TBF) items varied as a function of valence and arousal with reduced directed forgetting for high arousing negative and neutral words. In the brain, patterns of frontal and posterior activation in response to TBF and TBR cues respectively replicated prior EEG evidence to support involvement of inhibitory and selective rehearsal mechanisms in item directed forgetting. Interestingly, emotion only impacted cue-related posterior activity, which varied depending on specific interactions between valence and arousal. Together, results suggest that the brain handles valence and arousal differently and highlights the importance of considering in a collective manner the multidimensional nature of emotion in experimentation.

  17. The effect of exercise-induced arousal on chosen tempi for familiar melodies.

    Science.gov (United States)

    Jakubowski, Kelly; Halpern, Andrea R; Grierson, Mick; Stewart, Lauren

    2015-04-01

    Many previous studies have shown that arousal affects time perception, suggesting a direct influence of arousal on the speed of the pacemaker of the internal clock. However, it is unknown whether arousal influences the mental representation of tempo (speed) for highly familiar and complex stimuli, such as well-known melodies, that have long-term representations in memory. Previous research suggests that mental representations of the tempo of familiar melodies are stable over time; the aim of the present study was to investigate whether these representations can be systematically altered via an increase in physiological arousal. Participants adjusted the tempo of 14 familiar melodies in real time until they found a tempo that matched their internal representation of the appropriate tempo for that piece. The task was carried out before and after a physiologically arousing (exercise) or nonarousing (anagrams) manipulation. Participants completed this task both while hearing the melodies aloud and while imagining them. Chosen tempi increased significantly following exercise-induced arousal, regardless of whether a melody was heard aloud or imagined. These findings suggest that a change in internal clock speed affects temporal judgments even for highly familiar and complex stimuli such as music.

  18. Highly efficient degradation of thidiazuron with Ag/AgCl- activated carbon composites under LED light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yisi [College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128 (China); Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University, Huanggang 438000 (China); College of Chemical Engineering, Huanggang Normal University, Huanggang 438000 (China); Zhang, Yan [Hubei Key Laboratory for Processing and Application of Catalytic Materials, Huanggang Normal University, Huanggang 438000 (China); College of Chemical Engineering, Huanggang Normal University, Huanggang 438000 (China); Dong, Mingguang; Yan, Ting; Zhang, Maosheng [College of Chemical Engineering, Huanggang Normal University, Huanggang 438000 (China); Zeng, Qingru, E-mail: 40083763@qq.com [College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128 (China)

    2017-08-05

    Highlights: • Photocatalytic degradation of thidiazuron was performed in a neutral water matrix. • This was carried out in the presence of Ag/AgCl-activated carbon composites and LED light. • The pH effect and the dominant active species were explored. • Degradation products and pathways in water were studied for the first time. - Abstract: Thidiazuron (TDZ; 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea) is one of the most widely used defoliant and easy to dissolve in surface water. Risk associated with the pesticide is not clearly defined, so it is important to remove/degrade TDZ with an efficient and environment friendly technology. Here, we investigated the use of Ag/AgCl-activated carbon (Ag/AgCl–AC) composites in photocatalytic degradation of TDZ under LED light. By the synergic effect of Ag/AgCl and AC, the optimum Ag/carbon weight ratio of 2:1 exhibited superior visible-light photocatalytic activity, the highest removal efficiency was close to 91% in pH 7 matrix. Different types of Ag/AgCl–AC composites were tested, all showed much faster photodegradation kinetics than bare Ag/AgCl in 210 min. The degradation products as identified by HPLC–MS revealed that the hydroxylation by hydroxyl radicals and that of oxidation by superoxide radicals as well as holes were the two main pathways for TDZ degradation. Results revealed that the adsorption concentrated TDZ molecules and the photocatalytically generated radicals rapidly degradated TDZ, the two contributions functioned together for removal of the pollutant from water.

  19. The Role of Arousal in the Spontaneous Regulation of Emotions in Healthy Aging: An fMRI Investigation

    Directory of Open Access Journals (Sweden)

    Sanda eDolcos

    2014-07-01

    Full Text Available Despite ample support for enhanced affective well-being and emotional stability in healthy aging, the role of potentially important dimensions, such as the emotional arousal, has not been systematically investigated in neuroimaging studies. In addition, the few behavioral studies that examined effects of arousal have produced inconsistent findings. The present study manipulated the arousal of pictorial stimuli to test the hypothesis that preserved emotional functioning in aging is modulated by the level of arousal, and to identify the associated neural correlates. Young and older healthy participants were presented with negative and neutral pictures, which they rated for emotional content, while fMRI data were recorded. There were three main novel findings regarding the neural mechanisms underlying the processing of negative pictures with different levels of arousal in young and older adults. First, the common engagement of the right amygdala in young and older adults was driven by high arousing negative stimuli. Second, complementing an age-related reduction in the subjective ratings for low arousing negative pictures, there were opposing patterns of activity in the rostral/ventral anterior cingulate cortex (ACC and the amygdala, which showed increased vs. decreased responses, respectively, to low arousing negative pictures. Third, increased spontaneous activity in the ventral ACC/ventromedial prefrontal cortex (vmPFC in older adults was linked to reduced ratings for low arousing negative pictures. Overall, these findings advance our understanding of the neural correlates underlying processing of negative emotions with different levels of arousal in the context of enhanced emotional functioning in healthy aging. Notably, the results support the idea that older adults have emotion regulation networks chronically activated, in the absence of explicit induction of the goal to regulate emotions, and that this effect is specific to low arousing

  20. The role of arousal in the spontaneous regulation of emotions in healthy aging: a fMRI investigation.

    Science.gov (United States)

    Dolcos, Sanda; Katsumi, Yuta; Dixon, Roger A

    2014-01-01

    Despite ample support for enhanced affective well-being and emotional stability in healthy aging, the role of potentially important dimensions, such as the emotional arousal, has not been systematically investigated in neuroimaging studies. In addition, the few behavioral studies that examined effects of arousal have produced inconsistent findings. The present study manipulated the arousal of pictorial stimuli to test the hypothesis that preserved emotional functioning in aging is modulated by the level of arousal, and to identify the associated neural correlates. Young and older healthy participants were presented with negative and neutral pictures, which they rated for emotional content, while fMRI data were recorded. There were three main novel findings regarding the neural mechanisms underlying the processing of negative pictures with different levels of arousal in young and older adults. First, the common engagement of the right amygdala in young and older adults was driven by high arousing negative stimuli. Second, complementing an age-related reduction in the subjective ratings for low arousing negative pictures, there were opposing patterns of activity in the rostral/ventral anterior cingulate cortex (ACC) and the amygdala, which showed increased vs. decreased responses, respectively, to low arousing negative pictures. Third, increased spontaneous activity in the ventral ACC/ventromedial prefrontal cortex (vmPFC) in older adults was linked to reduced ratings for low arousing negative pictures. Overall, these findings advance our understanding of the neural correlates underlying processing of negative emotions with different levels of arousal in the context of enhanced emotional functioning in healthy aging. Notably, the results support the idea that older adults have emotion regulation networks chronically activated, in the absence of explicit induction of the goal to regulate emotions, and that this effect is specific to low arousing negative emotions.

  1. Long-term stable stacked CsPbBr3 quantum dot films for highly efficient white light generation in LEDs.

    Science.gov (United States)

    Song, Young Hyun; Yoo, Jin Sun; Kang, Bong Kyun; Choi, Seung Hee; Ji, Eun Kyung; Jung, Hyun Suk; Yoon, Dae Ho

    2016-12-01

    We report highly efficient ethyl cellulose with CsPbBr3 perovskite QD films for white light generation in LED application. Ethyl cellulose with CsPbBr3 quantum dots is applied with Sr2Si5N8 : Eu(2+) red phosphor on an InGaN blue chip, achieving a highly efficient luminous efficacy of 67.93 lm W(-1) under 20 mA current.

  2. Structure and Substrate for High Power White LED Package%大功率白光LED封装结构和封装基板

    Institute of Scientific and Technical Information of China (English)

    方军; 花刚; 傅仁利; 顾席光; 赵维维; 钱凤娇; 钱斐

    2013-01-01

    随着LED在照明领域的不断发展,功率和亮度不断提高,尤其是大功率白光LED的出现,热问题成为制约LED进一步发展的关键问题.介绍了大功率白光LED引脚式封装、表面贴装式(SMT)、板上芯片直装式(COB)和系统封装式(SiP)封装结构和金属、金属基复合以及陶瓷封装材料.重点阐述了金属芯印刷电路板(MCPCB)、金属基复合材料板以及陶瓷基板(如厚膜陶瓷基板、薄膜陶瓷基板、低温共烧陶瓷基板)等应用于大功率白光LED的封装基板,对各个基板的特点和散热能力进行了分析和对比.最后对大功率白光LED封装结构和封装基板的发展趋势进行了展望.%With the development of light emitting diode ( LED) in the lighting field, especially the appearance of high power white LED whose power and brightness become more and higher, thermal problems become the key factors of LED further development. The lamp LED, surface mounted technology (SMT) , chip on board (COB) and system in package (SiP) package structure, and metal, metal matrix composites and ceramics package materials used in high power white LED are introduced. At the same time, the metal core printed circuit board (MCPCB) , metal matrix composites plate and the ceramic substrate ( such as thick film ceramic substrate, thin film ceramic substrate and low temperature co-fired ceramic substrate) used in high power white LED package substrate are reviewed. And the various characteristics and thermal conductivity of the substrate are analyzed and compared. Finally, the high power white LED package development trend of the structure and the package substrate is prospected.

  3. Psychological skills for enhancing performance: arousal regulation strategies.

    Science.gov (United States)

    Gould, D; Udry, E

    1994-04-01

    This review summarizes and integrates current empirical and theoretical research on arousal regulation strategies for enhancing athletic performance. The need to view arousal as a multifaceted construct made up of both cognitive and physiological components was emphasized, as well as the importance of understanding arousal-performance relationship theories that go beyond a simple inverted-U notion. Categories of arousal regulation strategies were discussed and included: arousal energizing techniques, biofeedback techniques, relaxation response strategies, cognitive behavioral interventions, and mental preparation routines. It was concluded that these techniques can be effective in influencing arousal and facilitating performance. However, additional research (especially evaluation research) using more rigorous methods, determining how and why interventions work, using case study methodologies, identifying personality and situational factors influencing arousal regulation effectiveness, and identifying the most effective means of teaching arousal regulation is needed.

  4. Concepts and mechanisms of generalized central nervous system arousal.

    Science.gov (United States)

    Pfaff, Donald; Ribeiro, Ana; Matthews, James; Kow, Lee-Ming

    2008-01-01

    A concept of generalized arousal of the CNS is presented and given an operational definition that leads to quantitative physical measures. Because this primitive arousal function underlies all motivated behavioral responses, cognitive functions, and emotional expression, disorders of generalized arousal can be associated with a large number of problems in medicine and public health, including vegetative states, attentional disorders, depression, occupational hazards, and problems with sleep and anesthesia. Some of its known mechanisms are briefly reviewed, at the levels of neuroanatomy, neurophysiology, and functional genomics. Generalized arousal contributes to the excitement and the activation of behaviors during specific arousal states. Data are summarized for four genomic/neurochemical systems through which changes in generalized arousal could affect sexual arousal, two of which heighten, and the other two of which reduce arousal.

  5. Disgust versus Lust: Exploring the Interactions of Disgust and Fear with Sexual Arousal in Women.

    Directory of Open Access Journals (Sweden)

    Diana S Fleischman

    Full Text Available Sexual arousal is a motivational state that moves humans toward situations that inherently pose a risk of disease transmission. Disgust is an emotion that adaptively moves humans away from such situations. Incongruent is the fact that sexual activity is elementary to human fitness yet involves strong disgust elicitors. Using an experimental paradigm, we investigated how these two states interact. Women (final N=76 were assigned to one of four conditions: rate disgust stimuli then watch a pornographic clip; watch a pornographic clip then rate disgust stimuli; rate fear stimuli then watch a pornographic clip; or watch a pornographic clip then rate fear stimuli. Women's genital sexual arousal was measured with vaginal photoplethysmography and their disgust and fear reactions were measured via self-report. We did not find that baseline disgust propensity predicted sexual arousal in women who were exposed to neutral stimuli before erotic content. In the Erotic-before-Disgust condition we did not find that sexual arousal straightforwardly predicted decreased image disgust ratings. However, we did find some evidence that sexual arousal increased self-reported disgust in women with high trait disgust and sexual arousal decreased self-reported disgust in women with low trait disgust. Women who were exposed to disgusting images before erotic content showed significantly less sexual arousal than women in the control condition or women exposed to fear-inducing images before erotic content. In the Disgust-before-Erotic condition the degree of self-reported disgust was negatively correlated with genital sexual arousal. Hence, in the conflict between the ultimate goals of reproduction and disease avoidance, cues of the presence of pathogens significantly reduce the motivation to engage in mating behaviors that, by their nature, entail a risk of pathogen transmission.

  6. Disgust versus Lust: Exploring the Interactions of Disgust and Fear with Sexual Arousal in Women

    Science.gov (United States)

    Fleischman, Diana S.; Hamilton, Lisa Dawn; Fessler, Daniel M. T.; Meston, Cindy M.

    2015-01-01

    Sexual arousal is a motivational state that moves humans toward situations that inherently pose a risk of disease transmission. Disgust is an emotion that adaptively moves humans away from such situations. Incongruent is the fact that sexual activity is elementary to human fitness yet involves strong disgust elicitors. Using an experimental paradigm, we investigated how these two states interact. Women (final N=76) were assigned to one of four conditions: rate disgust stimuli then watch a pornographic clip; watch a pornographic clip then rate disgust stimuli; rate fear stimuli then watch a pornographic clip; or watch a pornographic clip then rate fear stimuli. Women’s genital sexual arousal was measured with vaginal photoplethysmography and their disgust and fear reactions were measured via self-report. We did not find that baseline disgust propensity predicted sexual arousal in women who were exposed to neutral stimuli before erotic content. In the Erotic-before-Disgust condition we did not find that sexual arousal straightforwardly predicted decreased image disgust ratings. However, we did find some evidence that sexual arousal increased self-reported disgust in women with high trait disgust and sexual arousal decreased self-reported disgust in women with low trait disgust. Women who were exposed to disgusting images before erotic content showed significantly less sexual arousal than women in the control condition or women exposed to fear-inducing images before erotic content. In the Disgust-before-Erotic condition the degree of self-reported disgust was negatively correlated with genital sexual arousal. Hence, in the conflict between the ultimate goals of reproduction and disease avoidance, cues of the presence of pathogens significantly reduce the motivation to engage in mating behaviors that, by their nature, entail a risk of pathogen transmission. PMID:26106894

  7. Comparison of different LED Packages

    Science.gov (United States)

    Dieker, Henning; Miesner, Christian; Püttjer, Dirk; Bachl, Bernhard

    2007-09-01

    In this paper different technologies for LED packaging are compared, focusing on Chip on Board (COB) and SMD technology. The package technology which is used depends on the LED application. A critical fact in LED technology is the thermal management, especially for high brightness LED applications because the thermal management is important for reliability, lifetime and electrooptical performance of the LED module. To design certain and long life LED applications knowledge of the heat flow from LEDs to the complete application is required. High sophisticated FEM simulations are indispensable for modern development of high power LED applications. We compare simulations of various substrate materials and packaging technologies simulated using FLOTHERM software. Thereby different substrates such as standard FR4, ceramic and metal core printed circuit boards are considered. For the verification of the simulated results and the testing of manufactured modules, advanced measurement tools are required. We show different ways to experimentally characterize the thermal behavior of LED modules. The thermal path is determined by the transient thermal analysis using the MicReD T3Ster analyzer. Afterwards it will be compared to the conventional method using thermocouples. The heat distribution over the module is investigated by an IR-Camera. We demonstrate and compare simulation and measurement results of Chip-on-Board (COB) and Sub-Mounted Devices (SMD) technology. The results reveal that for different applications certain packages are ideal.

  8. Process and Outcomes From a Youth-Led Campaign to Address Healthy Eating in an Urban High School.

    Science.gov (United States)

    Frerichs, Leah; Sjolie, Sarah; Curtis, Matthew; Peterson, Melissa; Huang, Terry T-K

    2015-12-01

    This article describes a pilot youth advocacy initiative for obesity prevention informed by social cognitive theory, social network theory, and theories of community mobilization. With assistance from school and health leaders, adolescent-aged youth led a cafeteria food labeling and social marketing campaign. We implemented an anonymous survey 2 weeks prior to and again at the conclusion of the campaign, and used cafeteria records to track servings of fruits and vegetables. The campaign resulted in a significant increase in youths' confidence to identify healthy foods (OR 1.97, 95 % CI 1.01, 3.84, p = .048), and a significant increase in per person per day servings of fruits (0.02, p = .03) and vegetables (0.01, p = .02). The results of our pilot were promising, and the integration of concepts from multiple theories benefited the implementation process. Obesity prevention initiatives should include strategies that encourage youth to create health promotion community networks and lead changes to their social and physical environments.

  9. Effects of Self-Efficacy on Fear Arousal and Performance.

    Science.gov (United States)

    Suarez, Yolanda; Crowe, Michael J.

    While self-efficacy has been described as a basic mechanism underlying arousal and performance, the hypothesis that belief of higher self-efficacy should produce lower anticipatory arousal and distress has not been proven. This study assessed perceived self-efficacy, self-report measures of fear and arousal, performance across sex, and a…

  10. Functional Analysis in Long-Term Operation of High Power UV-LEDs in Continuous Fluoro-Sensing Systems for Hydrocarbon Pollution.

    Science.gov (United States)

    Arques-Orobon, Francisco Jose; Nuñez, Neftali; Vazquez, Manuel; Gonzalez-Posadas, Vicente

    2016-02-26

    This work analyzes the long-term functionality of HP (High-power) UV-LEDs (Ultraviolet Light Emitting Diodes) as the exciting light source in non-contact, continuous 24/7 real-time fluoro-sensing pollutant identification in inland water. Fluorescence is an effective alternative in the detection and identification of hydrocarbons. The HP UV-LEDs are more advantageous than classical light sources (xenon and mercury lamps) and helps in the development of a low cost, non-contact, and compact system for continuous real-time fieldwork. This work analyzes the wavelength, output optical power, and the effects of viscosity, temperature of the water pollutants, and the functional consistency for long-term HP UV-LED working operation. To accomplish the latter, an analysis of the influence of two types 365 nm HP UV-LEDs degradation under two continuous real-system working mode conditions was done, by temperature Accelerated Life Tests (ALTs). These tests estimate the mean life under continuous working conditions of 6200 h and for cycled working conditions (30 s ON & 30 s OFF) of 66,000 h, over 7 years of 24/7 operating life of hydrocarbon pollution monitoring. In addition, the durability in the face of the internal and external parameter system variations is evaluated.

  11. An approach to utilize the artificial high power LED UV-A radiation in photoreactors for the degradation of methylene blue.

    Science.gov (United States)

    Betancourt-Buitrago, L A; Vásquez, C; Veitia, L; Ossa-Echeverry, O; Rodriguez-Vallejo, J; Barraza-Burgos, J; Marriaga-Cabrales, N; Machuca-Martínez, F

    2017-01-18

    Utilization of UV LED light is trending in the development of photoreactors for pollutant treatment. In this study, two different geometries were studied in the degradation of methylenebBlue (MB) using high power UVA LED as a source of light. The dosage, initial concentration, electric power, and H2O2 addition were evaluated in the two geometries: a mini CPC (Cilindrical Parabolic Collector) and a vertical cylindrical with external irradiation both coupled with LED UVA. Best degradation was obtained for 0.3 g L(-1) TiO2, 40 min, and 15 ppm of MB of initial concentration in the standard batch reactor. It was found that the best system was a cpc geometry. Also, hydrogen peroxide was used as an electron acceptor and 97% degradation was obtained in 30 min with 10 mM H2O2 and 0.4 g TiO2/L. Power of the LEDs was also evaluated and it was found that 20 W m(-2) is the best operational condition to achieve the best MB degradation avoiding the oxidant species recombination.

  12. Power modulates over-reliance on false cardiac arousal when judging target attractiveness: the powerful are more centered on their own false arousal than the powerless.

    Science.gov (United States)

    Jouffre, Stéphane

    2015-01-01

    Individuals attempting to label their emotions look for a plausible source of their physiological arousal. Co-occurrence of plausible sources can lead to the misattribution of real (or bogus) physiological arousal, resulting in physically attractive individuals being perceived as more attractive than they actually are. In two experiments, female participants heard bogus heart rate feedback while viewing photos of attractive male models. Compared with low-power and control participants, high-power participants rated reinforced photos (increased heart rate) more attractive than non-reinforced photos (stable heart rate) to a greater extent when they heard their own bogus heart rate feedback (Experiments 1 and 2) and to a lesser extent when they heard a recording of another participant's heart rate (Experiment 2). These findings, which suggest that power increases the tendency to misattribute one's physiological arousal to physically attractive individuals, are discussed with reference to theories linking power and social perception.

  13. Vocal correlates of sender-identity and arousal in the isolation calls of domestic kitten (Felis silvestris catus

    Directory of Open Access Journals (Sweden)

    Scheumann Marina

    2012-12-01

    Full Text Available Abstract Introduction Human speech does not only communicate linguistic information but also paralinguistic features, e.g. information about the identity and the arousal state of the sender. Comparable morphological and physiological constraints on vocal production in mammals suggest the existence of commonalities encoding sender-identity and the arousal state of a sender across mammals. To explore this hypothesis and to investigate whether specific acoustic parameters encode for sender-identity while others encode for arousal, we studied infants of the domestic cat (Felis silvestris catus. Kittens are an excellent model for analysing vocal correlates of sender-identity and arousal. They strongly depend on the care of their mother. Thus, the acoustical conveyance of sender-identity and arousal may be important for their survival. Results We recorded calls of 18 kittens in an experimentally-induced separation paradigm, where kittens were spatially separated from their mother and siblings. In the Low arousal condition, infants were just separated without any manipulation. In the High arousal condition infants were handled by the experimenter. Multi-parametric sound analyses revealed that kitten isolation calls are individually distinct and differ between the Low and High arousal conditions. Our results suggested that source- and filter-related parameters are important for encoding sender-identity, whereas time-, source- and tonality-related parameters are important for encoding arousal. Conclusion Comparable findings in other mammalian lineages provide evidence for commonalities in non-verbal cues encoding sender-identity and arousal across mammals comparable to paralinguistic cues in humans. This favours the establishment of general concepts for voice recognition and emotions in humans and animals.

  14. Effects on archery performance of manipulating metamotivational state and felt arousal.

    Science.gov (United States)

    Kerr, J H; Yoshida, H; Hirata, C; Takai, K; Yamazaki, F

    1997-06-01

    This study investigated the effect of the four different combinations of metamotivational state and felt arousal level (telic-low, paratelic-low, telic-high, paratelic-high) on archery performance. Skilled, average, and novice archers (n = 28) were voluntary subjects, randomly divided into 2 groups, balanced for ability. Each group performed 2 out of the 4 experimental conditions. In this reversal theory-based field experiment, telic and paratelic metamotivational states and arousal level were manipulated prior to archery performance. The hypothesis that archery performance would be superior under telic-low arousal conditions was rejected, but evidence pointed to the possible importance of hedonic tone in performance. Post boc analysis showed differences between combined high (telic-low, paratelic-high) and combined low (telic-low, paratelic-high) hedonic-tone groups which fell short of significance. This observation is taken as justification for further exploration of the relationship between hedonic tone and sports performance.

  15. Mn(4+),Li(+) co-doped SrMgAl10O17 phosphor-in-glass: application in high-power warm w-LEDs.

    Science.gov (United States)

    Zhong, Jiasong; Xu, Wei; Chen, Qingli; Yuan, Shuo; Ji, Zhengguo; Chen, Daqin

    2017-08-14

    Currently, the shortage of red components and easy aging of organic silicone still remain challenges for high-power phosphor-converted warm white light-emitting diodes (w-LEDs). Aiming to alleviate these issues, phosphor-in-glass (PiG), fabricated by co-sintering red- and yellow-emitting phosphors and low-melting glass, has been regarded as a promising color converter for w-LEDs. In this study, a Li(+),Mn(4+) co-doped SrMgAl10O17 red phosphor was synthesized via a conventional solid-state reaction. The as-prepared phosphor exhibits a deep red emission, ascribed to Mn(4+):(2)Eg→(4)A2g spin-forbidden transition in the range of 600-700 nm with a narrow-band full width at half maximum of 55 nm, and provides an ideal broadband excitation extending from 250 to 530 nm. Impressively, the Li(+) additive used as charge compensation was beneficial to enhance the Mn(4+) luminescence by allowing more Mn(4+) to replace Al(3+). Furthermore, the developed SrMgAl10O17:Mn(4+),Li(+) red phosphor and commercial YAG:Ce(3+) yellow phosphor co-doped inorganic PiG were successfully fabricated as color converters to substitute organic silicone. The w-LED was fabricated by combining an InGaN blue LED chip with a PiG plate. Importantly, the constructed w-LEDs exhibited superior optical performance and tuned chromaticity feature with the correlated color temperature evolved from bluish cool white (6903 K) to yellowish warm white (3717 K), and the color rendering index increased from 69.4 to 85.5, meeting the requirements for indoor lighting.

  16. Novel Transparent Phosphor Conversion Matrix with High Thermal Conductivity for Next Generation Phosphor-Converted LED-based Solid State Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Bockstaller, Michael [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2017-02-06

    The low thermal conductivity of state-of-the-art polymer encapsulants (k ~ 0.15 Wm-1K-1) limits the efficiency and power density of current phosphor conversion light emitting diodes (pc-LEDs). The technical objective of this project was to demonstrate synthesis and processing schemes for the fabrication of polymer hybrid encapsulants with a thermal conductivity exceeding k = 0.4 Wm-1K-1 for LED applications. The ‘hybrid polymer’ approach encompasses the dispersion of high thermal conductivity particle fillers (zinc oxide, ZnO as well as the alpha-polymorph of alumina, Al2O3) within a polysiloxane matrix (poly(dimethylsiloxane), PDMS as well as poly(phenyl methyl siloxane), PPMS) to increase the thermal conductivity while maintaining optical transparency and photothermal stability at levels consistent with LED applications. To accomplish this goal, a novel synthesis method for the fabrication of nanosized ZnO particles was developed and a novel surface chemistry was established to modify the surface of zinc oxide particle fillers and thus to enable their dispersion in poly(dimethyl siloxane) (PDMS) matrix polymers. Molecular dynamics and Mie simulations were used to optimize ligand structure and to enable the concurrent mixing of particles in PDMS/PPMS embedding media while also minimizing the thermal boundary resistance as well as optical scattering of particle fillers. Using this approach the synthesis of PDMS/ZnO hybrid encapsulants exhibiting a thermal conductivity of 0.64 Wm-1K-1 and optical transparency > 0.7 mm-1 was demonstrated. A forming process based on micromolding was developed to demonstrate the forming of particle filled PDMS into film and lens shapes. Photothermal stability testing revealed stability of the materials for approximately 4000 min when exposed to blue light LED (450 nm, 30 W/cm2). One postgraduate and seven graduate students were supported by the project. The research performed within this project led to fifteen publications in peer

  17. Arousal and mood factors in the "Mozart effect".

    Science.gov (United States)

    Steele, K M

    2000-08-01

    Some investigators of the "Mozart effect" have not controlled for the influence of differences in arousal or mood induced by treatment conditions. Studies by Rideout and colleagues reported differences in spatial reasoning after listening to a Mozart sonata compared against a relaxation instruction tape. The conditions may have affected subjects' arousal differentially, with the sonata increasing arousal and the relaxation instructions decreasing arousal, which could have affected spatial reasoning performance. Evidence is cited in support of this suggestion and indicates the importance of analyzing the influence of arousal differences in Mozart effect research.

  18. Post-learning arousal enhances veridical memory and reduces false memory in the Deese-Roediger-McDermott paradigm.

    Science.gov (United States)

    Nielson, Kristy A; Correro, Anthony N

    2017-10-01

    The Deese-Roediger-McDermott (DRM) paradigm examines false memory by introducing words associated with a non-presented 'critical lure' as memoranda, which typically causes the lures to be remembered as frequently as studied words. Our prior work has shown enhanced veridical memory and reduced misinformation effects when arousal is induced after learning (i.e., during memory consolidation). These effects have not been examined in the DRM task, or with signal detection analysis, which can elucidate the mechanisms underlying memory alterations. Thus, 130 subjects studied and then immediately recalled six DRM lists, one after another, and then watched a 3-min arousing (n=61) or neutral (n=69) video. Recognition tested 70min later showed that arousal induced after learning led to better delayed discrimination of studied words from (a) critical lures, and (b) other non-presented 'weak associates.' Furthermore, arousal reduced liberal response bias (i.e., the tendency toward accepting dubious information) for studied words relative to all foils, including critical lures and 'weak associates.' Thus, arousal induced after learning effectively increased the distinction between signal and noise by enhancing access to verbatim information and reducing endorsement of dubious information. These findings provide important insights into the cognitive mechanisms by which arousal modulates early memory consolidation processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Research and Manufacturing of High Power Integrated LED Light Conversion Source%大功率集成LED光转换光源的研制

    Institute of Scientific and Technical Information of China (English)

    李茂龙; 隋玉龙; 吴粤宁; 戴兴建

    2012-01-01

    介绍了一种应用远程激发技术的大功率集成LED光转换光源,通过使用固晶区无绝缘层的镜面铝基板进行集成封装蓝光LED光源,即COB光源.所制蓝光光源与远程激发荧光粉模块结合制成LED光转换光源.利用镜面铝基板的高导热系数,解决多种LED封装形式下芯片点亮温度过高、光源衰减快的问题.采用LED荧光高分子模块与蓝光芯片分离结合的远程激发技术制成白光光源,解决荧光粉分布不均、热老化、色偏移问题.通过与传统粉胶封装方式制得的大功率集成LED器件比较测试,该种光源具有防眩光、光色均匀度高、长寿命、节能和环保的优点,从而具有更广泛的用途.%A high-power integrated LED light conversion light source applying remote excitation technique was introduced. The blue LED that is COB package blue LED through mirror-free aluminum plate without insulating layer in solid crystal area to develop to LED light conversion source with remote excited phosphor module. The problems of lots of package chip light temperature too high and light attenuation too fast were solved by using high thermal conductivity coefficient of mirror aluminum plate. And it is an effective solution to the issue of uneven distribution of phosphor, thermal aging of phosphor and color offset. Compared with traditional phosphor and resin glue package pattern, the high-power LED has the advantages of anti-dazzle, high light color degree of homogeneity, long life, energy saving, and environmental protection, so as to achieve more widely uses.

  20. Research on the Cooling Technology for the High-Power LED Bay Lamp%LED工矿灯散热技术研究

    Institute of Scientific and Technical Information of China (English)

    罗婉霞

    2013-01-01

    为满足LED工矿灯的散热需求,设计了一款新型烧结热管式的散热模组,对该模组进行了应用于不同环境温度条件的数值模拟研究,并与实验数据进行了比较分析。结果发现,数值模拟与实验所得结果偏差在4.01%以内。这表明,所设计散热方案能够很好地满足该种LED工矿灯在不同环境下的散热需求,该数值模拟方法能够为今后设计同类产品提供设计理论依据。%To meet the cooling requirement of the high-power LED bay lamp, a novel cooling module was designed. Furthermore, the numerical simulation research on the cooling module used for LED bay lamp was carried out,and the simulation result has been compared with the experimental data. The simulation result agrees well with the experimental data,and the relative error is within 4.01%. The result shows that the cooling solution proposed can meets the cooling requirement of the LED high bay designed on the different operating condition.

  1. High color rendering white light-emitting-diode illuminator using the red-emitting Eu(2+)-activated CaZnOS phosphors excited by blue LED.

    Science.gov (United States)

    Kuo, Te-Wen; Liu, Wei-Ren; Chen, Teng-Ming

    2010-04-12

    A red phosphor CaZnOS:Eu(2+) was synthesized by solid state reaction and has been evaluated as a candidate for white LEDs. For this material, the XRD, PL, PL excitation (PLE) and diffuse reflection spectra have also been investigated. CaZnOS:Eu(2+) reveals a broad absorption band and good color purity. By utilizing a mixture of red-emitting CaZnOS:Eu(2+), green-emitting (Ba,Sr)(2)SiO(4):Eu(2+) and yellow-emitting Y(3)Al(5)O(12):Ce(3+) as light converters, an intense white InGaN-based blue-LED (~460 nm) was fabricated to exhibit a high color-rendering index Ra of 85 at a correlated color temperature of 4870 K. Based on the results, we are currently evaluating the potential application of CaZnOS:Eu(2+) as a red-emitting blue-chip convertible phosphor.

  2. Nurse-led care interventions for high blood pressure control: Implications for non-communicable disease programs in Uganda

    Directory of Open Access Journals (Sweden)

    Godfrey Katende

    2016-01-01

    Conclusion: Nurses play a significant role in the control of high blood pressure when they employ effective evidence based strategies in identification, prevention and management of hypertension. Adapting effective evidence based strategies in identification, prevention and management of non-communicable diseases could improve patient outcomes in Uganda.

  3. Effect of a Cooling Step Treatment on a High-Voltage GaN LED During ICP Dry Etching

    Science.gov (United States)

    Lin, Yen-Sheng; Hsiao, Sheng-Yu; Tseng, Chun-Lung; Shen, Ching-Hsing; Chiang, Jung-Sheng

    2016-10-01

    In this study, a lower dislocation density for a GaN surface and a reduced current path are observed at the interface of a SiO2 isolation sidewall, using high-resolution transmission electron microscopy. This is grown using a 3-min cooling step treatment during inductivity coupled plasma dry etching. The lower forward voltage is measured, the leakage current decreases from 53nA to 32nA, and the maximum output power increases from 354.8 W to 357.2 W for an input current of 30 mA. The microstructure and the optoelectronic properties of high-voltage light-emitting-diodes is proven to be affected by the cooling step treatment, which allows enough time to release the thermal energy of the SiO2 isolation well.

  4. Effect of a Cooling Step Treatment on a High-Voltage GaN LED During ICP Dry Etching

    Science.gov (United States)

    Lin, Yen-Sheng; Hsiao, Sheng-Yu; Tseng, Chun-Lung; Shen, Ching-Hsing; Chiang, Jung-Sheng

    2017-02-01

    In this study, a lower dislocation density for a GaN surface and a reduced current path are observed at the interface of a SiO2 isolation sidewall, using high-resolution transmission electron microscopy. This is grown using a 3-min cooling step treatment during inductivity coupled plasma dry etching. The lower forward voltage is measured, the leakage current decreases from 53nA to 32nA, and the maximum output power increases from 354.8 W to 357.2 W for an input current of 30 mA. The microstructure and the optoelectronic properties of high-voltage light-emitting-diodes is proven to be affected by the cooling step treatment, which allows enough time to release the thermal energy of the SiO2 isolation well.

  5. Developing Sustainable Farmer-Led Extension Groups: Lessons from a Bangladeshi Case Study

    Science.gov (United States)

    Islam, Md. Mofakkarul; Gray, David; Reid, Janet; Kemp, Peter

    2011-01-01

    The limited effectiveness and fiscal unsustainability of professional-led public sector extension systems in developing countries have aroused considerable interest in Farmer-led Extension (FLE) approaches in the recent decades. A key challenge facing these initiatives is a lack of sustainability of the farmer groups developed through project or…

  6. Thermally Stable White Emitting Eu(3+) Complex@Nanozeolite@Luminescent Glass Composite with High CRI for Organic-Resin-Free Warm White LEDs.

    Science.gov (United States)

    Zhang, Jinhui; Gong, Shuming; Yu, Jinbo; Li, Peng; Zhang, Xuejie; He, Yuwei; Zhou, Jianbang; Shi, Rui; Li, Huanrong; Peng, Aiyun; Wang, Jing

    2017-03-01

    Nowadays, it is still a great challenge for lanthanide complexes to be applied in solid state lighting, especially for high-power LEDs because they will suffer severe thermal-induced luminescence quenching and transmittance loss when LEDs are operated at high current. In this paper, we have not only obtained high efficient and thermally chemical stable red emitting hybrid material by introducing europium complex into nanozeolite (NZ) functionalized with the imidazolium-based stopper but also abated its thermal-induced transmittance loss and luminescence quenching behavior via coating it onto a heat-resistant luminescent glass (LG) with high thermal conductivity (1.07 W/mK). The results show that the intensity at 400 K for Eu(PPO)n-C4Si@NZ@LG remains 21.48% of the initial intensity at 300 K, which is virtually 153 and 13 times the intensity of Eu(PPO)3·2H2O and Eu(PPO)n-C4Si@NZ, respectively. Moreover, an organic-resin-free warm white LEDs device with a low CCT of 3994K, a high Ra of 90.2 and R9 of 57.9 was successfully fabricated simply by combining NUV-Chip-On-Board with a warm white emitting glass-film composite (i.e., yellowish-green emitting luminescent glass coated with red emitting hybrid film). Our method and results provide a feasible and promising way for lanthanide complexes to be used for general illumination in the future.

  7. Mindfulness-Based Sex Therapy Improves Genital-Subjective Arousal Concordance in Women With Sexual Desire/Arousal Difficulties.

    Science.gov (United States)

    Brotto, Lori A; Chivers, Meredith L; Millman, Roanne D; Albert, Arianne

    2016-11-01

    There is emerging evidence for the efficacy of mindfulness-based interventions for improving women's sexual functioning. To date, this literature has been limited to self-reports of sexual response and distress. Sexual arousal concordance-the degree of agreement between self-reported sexual arousal and psychophysiological sexual response-has been of interest due to the speculation that it may be a key component to healthy sexual functioning in women. We examined the effects of mindfulness-based sex therapy on sexual arousal concordance in a sample of women with sexual desire/arousal difficulties (n = 79, M age 40.8 years) who participated in an in-laboratory assessment of sexual arousal using a vaginal photoplethysmograph before and after four sessions of group mindfulness-based sex therapy. Genital-subjective sexual arousal concordance significantly increased from pre-treatment levels, with changes in subjective sexual arousal predicting contemporaneous genital sexual arousal (but not the reverse). These findings have implications for our understanding of the mechanisms by which mindfulness-based sex therapy improves sexual functioning in women, and suggest that such treatment may lead to an integration of physical and subjective arousal processes. Moreover, our findings suggest that future research might consider the adoption of sexual arousal concordance as a relevant endpoint in treatment outcome research of women with sexual desire/arousal concerns.

  8. Feelings of disgust and disgust-induced avoidance weaken following induced sexual arousal in women.

    Directory of Open Access Journals (Sweden)

    Charmaine Borg

    Full Text Available BACKGROUND: Sex and disgust are basic, evolutionary relevant functions that are often construed as paradoxical. In general the stimuli involved in sexual encounters are, at least out of context strongly perceived to hold high disgust qualities. Saliva, sweat, semen and body odours are among the strongest disgust elicitors. This results in the intriguing question of how people succeed in having pleasurable sex at all. One possible explanation could be that sexual engagement temporarily reduces the disgust eliciting properties of particular stimuli or that sexual engagement might weaken the hesitation to actually approach these stimuli. METHODOLOGY: Participants were healthy women (n = 90 randomly allocated to one of three groups: the sexual arousal, the non-sexual positive arousal, or the neutral control group. Film clips were used to elicit the relevant mood state. Participants engaged in 16 behavioural tasks, involving sex related (e.g., lubricate the vibrator and non-sex related (e.g., take a sip of juice with a large insect in the cup stimuli, to measure the impact of sexual arousal on feelings of disgust and actual avoidance behaviour. PRINCIPAL FINDINGS: The sexual arousal group rated the sex related stimuli as less disgusting compared to the other groups. A similar tendency was evident for the non-sex disgusting stimuli. For both the sex and non-sex related behavioural tasks the sexual arousal group showed less avoidance behaviour (i.e., they conducted the highest percentage of tasks compared to the other groups. SIGNIFICANCE: This study has investigated how sexual arousal interplays with disgust and disgust eliciting properties in women, and has demonstrated that this relationship goes beyond subjective report by affecting the actual approach to disgusting stimuli. Hence, this could explain how we still manage to engage in pleasurable sexual activity. Moreover, these findings suggest that low sexual arousal might be a key feature in the

  9. Epidural electrocorticography for monitoring of arousal in locked-in state

    Directory of Open Access Journals (Sweden)

    Alireza eGharabaghi

    2014-10-01

    Full Text Available Electroencephalography often fails to assess both the level (i.e. arousal and the content (i.e. awareness of pathologically altered consciousness in patients without motor responsiveness. This might be related to a decline of awareness, to episodes of low arousal and disturbed sleep patterns, and/or to distorting and attenuating effects of the skull and intermediate tissue on the recorded brain signals. Novel approaches are required to overcome these limitations.We introduced epidural electrocorticography (ECoG for monitoring of cortical physiology in a late-stage amytrophic lateral sclerosis patient in completely locked-in state. Despite long-term application for a period of six months, no implant-related complications occurred. Recordings from the left frontal cortex were sufficient to identify three arousal states. Spectral analysis of the intrinsic oscillatory activity enabled us to extract state-dependent dominant frequencies at < 4, ~ 7 and ~ 20 Hz, representing sleep-like periods, and phases of low and elevated arousal, respectively. In the absence of other biomarkers, ECoG proved to be a reliable tool for monitoring circadian rhythmicity, i.e. avoiding interference with the patient when he was sleeping and exploiting time windows of responsiveness. Moreover, the effects of interventions addressing the patient’s arousal, e.g. amantadine medication, could be evaluated objectively on the basis of physiological markers, even in the absence of behavioral parameters.Epidural ECoG constitutes a feasible trade-off between surgical risk and quality of recorded brain signals to gain information on the patient’s present level of arousal. This approach enables us to optimize the timing of interactions and medical interventions, all of which should take place when the patient is in a phase of high arousal. Furthermore, avoiding low-responsiveness periods will facilitate measures to implement alternative communication pathways involving brain

  10. Brain processing of emotional scenes in aging: effect of arousal and affective context.

    Science.gov (United States)

    Mathieu, Nicolas Gilles; Gentaz, Edouard; Harquel, Sylvain; Vercueil, Laurent; Chauvin, Alan; Bonnet, Stéphane; Campagne, Aurélie

    2014-01-01

    Research on emotion showed an increase, with age, in prevalence of positive information relative to negative ones. This effect is called positivity effect. From the cerebral analysis of the Late Positive Potential (LPP), sensitive to attention, our study investigated to which extent the arousal level of negative scenes is differently processed between young and older adults and, to which extent the arousal level of negative scenes, depending on its value, may contextually modulate the cerebral processing of positive (and neutral) scenes and favor the observation of a positivity effect with age. With this aim, two negative scene groups characterized by two distinct arousal levels (high and low) were displayed into two separate experimental blocks in which were included positive and neutral pictures. The two blocks only differed by their negative pictures across participants, as to create two negative global contexts for the processing of the positive and neutral pictures. The results show that the relative processing of different arousal levels of negative stimuli, reflected by LPP, appears similar between the two age groups. However, a lower activity for negative stimuli is observed with the older group for both tested arousal levels. The processing of positive information seems to be preserved with age and is also not contextually impacted by negative stimuli in both younger and older adults. For neutral stimuli, a significantly reduced activity is observed for older adults in the contextual block of low-arousal negative stimuli. Globally, our study reveals that the positivity effect is mainly due to a modulation, with age, in processing of negative stimuli, regardless of their arousal level. It also suggests that processing of neutral stimuli may be modulated with age, depending on negative context in which they are presented to. These age-related effects could contribute to justify the differences in emotional preference with age.

  11. Brain processing of emotional scenes in aging: effect of arousal and affective context.

    Directory of Open Access Journals (Sweden)

    Nicolas Gilles Mathieu

    Full Text Available Research on emotion showed an increase, with age, in prevalence of positive information relative to negative ones. This effect is called positivity effect. From the cerebral analysis of the Late Positive Potential (LPP, sensitive to attention, our study investigated to which extent the arousal level of negative scenes is differently processed between young and older adults and, to which extent the arousal level of negative scenes, depending on its value, may contextually modulate the cerebral processing of positive (and neutral scenes and favor the observation of a positivity effect with age. With this aim, two negative scene groups characterized by two distinct arousal levels (high and low were displayed into two separate experimental blocks in which were included positive and neutral pictures. The two blocks only differed by their negative pictures across participants, as to create two negative global contexts for the processing of the positive and neutral pictures. The results show that the relative processing of different arousal levels of negative stimuli, reflected by LPP, appears similar between the two age groups. However, a lower activity for negative stimuli is observed with the older group for both tested arousal levels. The processing of positive information seems to be preserved with age and is also not contextually impacted by negative stimuli in both younger and older adults. For neutral stimuli, a significantly reduced activity is observed for older adults in the contextual block of low-arousal negative stimuli. Globally, our study reveals that the positivity effect is mainly due to a modulation, with age, in processing of negative stimuli, regardless of their arousal level. It also suggests that processing of neutral stimuli may be modulated with age, depending on negative context in which they are presented to. These age-related effects could contribute to justify the differences in emotional preference with age.

  12. LEDs for greenhouse lighting

    NARCIS (Netherlands)

    Nederhoff, E.M.

    2010-01-01

    Light Emitting Diodes (LED's) are a promising technology for greenhouse lighting with their efficiency to activate plant photosynthesis potentially higher in red LEDs than in HPS lamps. Due to their particular light colour, LEDs can initiate special effects in plants or steer plant processes and

  13. Emotion and decision-making under uncertainty: Physiological arousal predicts increased gambling during ambiguity but not risk.

    Science.gov (United States)

    FeldmanHall, Oriel; Glimcher, Paul; Baker, Augustus L; Phelps, Elizabeth A

    2016-10-01

    Uncertainty, which is ubiquitous in decision-making, can be fractionated into known probabilities (risk) and unknown probabilities (ambiguity). Although research has illustrated that individuals more often avoid decisions associated with ambiguity compared to risk, it remains unclear why ambiguity is perceived as more aversive. Here we examine the role of arousal in shaping the representation of value and subsequent choice under risky and ambiguous decisions. To investigate the relationship between arousal and decisions of uncertainty, we measure skin conductance response-a quantifiable measure reflecting sympathetic nervous system arousal-during choices to gamble under risk and ambiguity. To quantify the discrete influences of risk and ambiguity sensitivity and the subjective value of each option under consideration, we model fluctuating uncertainty, as well as the amount of money that can be gained by taking the gamble. Results reveal that although arousal tracks the subjective value of a lottery regardless of uncertainty type, arousal differentially contributes to the computation of value-that is, choice-depending on whether the uncertainty is risky or ambiguous: Enhanced arousal adaptively decreases risk-taking only when the lottery is highly risky but increases risk-taking when the probability of winning is ambiguous (even after controlling for subjective value). Together, this suggests that the role of arousal during decisions of uncertainty is modulatory and highly dependent on the context in which the decision is framed. (PsycINFO Database Record

  14. Affective picture processing and motivational relevance: arousal and valence effects on ERPs in an oddball task.

    Science.gov (United States)

    Briggs, Kate E; Martin, Frances H

    2009-06-01

    There are two dominant theories of affective picture processing; one that attention is more deeply engaged by motivationally relevant stimuli (i.e., stimuli that activate both the appetitive and aversive systems), and two that attention is more deeply engaged by aversive stimuli described as the negativity bias. In order to identify the theory that can best account for affective picture processing, event-related potentials (ERPs) were recorded from 34 participants during a modified oddball paradigm in which levels of stimulus valence, arousal, and motivational relevance were systematically varied. Results were partially consistent with motivated attention models of emotional perception, as P3b amplitude was enhanced in response to highly arousing and motivationally relevant sexual and unpleasant stimuli compared to respective low arousing and less motivationally relevant stimuli. However P3b amplitudes were significantly larger in response to the highly arousing sexual stimuli compared to all other affective stimuli, which is not consistent with either dominant theory. The current study therefore highlights the need for a revised model of affective picture processing and provides a platform for further research investigating the independent effects of sexual arousal on cognitive processing.

  15. Positive Affect and Cognitive Restoration: Investigating the Role of Valence and Arousal.

    Directory of Open Access Journals (Sweden)

    Logan J Nealis

    Full Text Available Positive moods are thought to restore self-control resources following depletion. However, it is not well understood whether this effect is due to affective valence (pleasantness, arousal (activation, or a combination of both. Across four studies, we set out to investigate the role of positive moods on cognitive and behavioral measures of self-regulation in an ego-depletion paradigm. In studies 1 and 2, we independently manipulated affective valence and arousal and assessed self-regulation with a Stroop task. Results did not suggest a restorative effect of either on cognitive resources. In study 3, we employed both behavioral (the 'handgrip task' and cognitive (Stroop assessments of self-regulation. Again, no significant effect of mood was observed on the Stroop task. Additionally, participants did not persist significantly longer on the handgrip task following a positive mood induction. Finally, in study 4, high vs. low states of arousal were manipulated and self-regulation was assessed via pre- and post-manipulation Stroop performance. In study 4, Stroop performance improved slightly more across time points for those in the high arousal condition than for those in the low arousal condition. Therefore, across four studies, we failed to find a consistent pattern of results suggesting that positive moods restore cognitive resources.

  16. High-efficiency blue LEDs with thin AlGaN interlayers in InGaN/GaN MQWs grown on Si (111) substrates

    Science.gov (United States)

    Kimura, Shigeya; Yoshida, Hisashi; Ito, Toshihide; Okada, Aoi; Uesugi, Kenjiro; Nunoue, Shinya

    2016-02-01

    We demonstrate high-efficiency blue light-emitting diodes (LEDs) with thin AlGaN interlayers in InGaN/GaN multiquantum wells (MQWs) grown on Si (111) substrates. The peak external quantum efficiency (EQE) ηEQE of 82% at room temperature and the hot/cold factor (HCF) of 94% have been obtained by using the functional thin AlGaN interlayers in the MQWs in addition to reducing threading dislocation densities (TDDs) in the blue LEDs. An HCF is defined as ηEQE(85°C)/ηEQE(25°C). The blue LED structures were grown by metal-organic chemical vapor deposition on Si (111) substrates. The MQWs applied as an active layer have 8- pairs of InGaN/AlyGa1-yN/GaN (0transmission electron microscopy and three-dimensional atom probe analysis that the 1 nm-thick AlyGa1-yN interlayers, whose Al content is y=0.3 or less, are continuously formed. EQE and the HCFs of the LEDs with thin Al0.15Ga0.85N interlayers are enhanced compared with those of the samples without the interlayers in the low-current-density region. We consider that the enhancement is due to both the reduction of the nonradiative recombination centers and the increase of the radiative recombination rate mediated by the strain-induced hole carriers indicated by the simulation of the energy band diagram.

  17. Red emission generation through highly efficient energy transfer from Ce(3+) to Mn(2+) in CaO for warm white LEDs.

    Science.gov (United States)

    Feng, Leyu; Hao, Zhendong; Zhang, Xia; Zhang, Liangliang; Pan, Guohui; Luo, Yongshi; Zhang, Ligong; Zhao, Haifeng; Zhang, Jiahua

    2016-01-28

    CaO:Ce(3+),Mn(2+) phosphors with various Mn(2+) concentrations were synthesized by a solid state reaction method. Efficient energy transfer from Ce(3+) to Mn(2+) was observed and it allows the emission color of CaO:Ce(3+),Mn(2+) to be continuously tuned from yellow (contributed by Ce(3+)) to red (by Mn(2+)) with an increase in Mn(2+) concentration and upon blue light excitation. The red emission becomes dominant when the Mn(2+) concentration is ≥0.014 with an energy transfer efficiency higher than 87% which can reach as high as 94% for a Mn(2+) concentration of only 0.02. A critical distance of 10.5 Å for the Ce(3+)-Mn(2+) energy transfer was determined. A faster decrease of Ce(3+) luminescence intensity in comparison with its lifetime was observed on increasing the Mn(2+) concentration. The analysis of this feature reveals that the Ce(3+) excitation energy can be completely transferred to Mn(2+) if the Ce(3+)-Mn(2+) distance is shorter than 7.6 Å. A warm white LED was fabricated through integrating an InGaN blue LED chip and a blend of two phosphors (YAG:Ce(3+) yellow phosphor and CaO:0.007Ce(3+),0.014Mn(2+) red phosphor) into a single package, which has CIE chromaticity coordinates of (x = 0.37, y = 0.35), a correlated color temperature of 3973 K and a color rendering index of 83.1. The results indicate that CaO:Ce(3+),Mn(2+) may serve as a potential red phosphor for blue LED based warm white LEDs.

  18. Package Technology of Silicon-based High-power LEDs with TSV%带有TSV的硅基大功率LED封装技术研究

    Institute of Scientific and Technical Information of China (English)

    师帅; 吕植成; 汪学方; 王飞; 袁娇娇; 方靖

    2013-01-01

    Introduced is the fabrication of silicon base with groove and TSV (through silicon via) for wafer level packaging of white LED.Based on the structure of silicon-based high-power LEDs,the heat transfer model is established and finite element software is employed to simulate and analyze the heat dissipation of this package.Simulation results show that the silicon base packaging meets the temperature requirement of LED chip p-n junction.Combined with semiconductor manufacturing process,the fabrication of the groove and TSV was carried out on the silicon substrate,realizing effective packaging of LED chips.The thermal resistance of silicon substrate measured by T3Ster is 1.068 K/W.Experimental results show that this method is effective for realizing LED chip packaging with low cost,low thermal resistance and high density.%介绍了一种带有凹槽和硅通孔(through silicon via,TSV)的硅基制备以及晶圆级白光LED的封装方法.针对硅基大功率LED的封装结构建立了热传导模型,并通过有限元软件模拟分析了这种封装形式的散热效果.模拟结果显示,硅基封装满足LED芯片p-n结的温度要求.实验结合半导体制造工艺,在硅基板上完成了凹槽和通孔的制造,实现了LED芯片的有效封装.热阻测试仪测得硅基的热阻为1.068 K/W.实验结果证明,这种方法有效实现了低热阻、低成本、高密度的LED芯片封装,是大功率LED封装发展的重要方向.

  19. LED-roulette: LED's vervangen balletje

    NARCIS (Netherlands)

    Goossens, P.

    2007-01-01

    Iedereen waagt wel eens een gokje, in een loterij of misschien ook in een casino. Wie droomt er immers niet van om op een gemakkelijke manier rijk te worden? Met de hier beschreven LED-roulette valt weliswaar weinig te winnen, maar het is wel een uitstekende manier om het roulettespel thuis te beoef

  20. LED-roulette: LED's vervangen balletje

    NARCIS (Netherlands)

    Goossens, P.

    2007-01-01

    Iedereen waagt wel eens een gokje, in een loterij of misschien ook in een casino. Wie droomt er immers niet van om op een gemakkelijke manier rijk te worden? Met de hier beschreven LED-roulette valt weliswaar weinig te winnen, maar het is wel een uitstekende manier om het roulettespel thuis te

  1. Design of a lighting system with high-power LEDs, large area electronics, and light management structure in the LUMENTILE European project

    Science.gov (United States)

    Carraro, L.; Simonetta, M.; Benetti, G.; Tramonte, A.; Capelli, G.; Benedetti, M.; Randone, E. M.; Ylisaukko-oja, A.; Keränen, K.; Facchinetti, T.; Giuliani, G.

    2017-02-01

    LUMENTILE (LUMinous ElectroNic TILE) is a project funded by the European Commission with the goal of developing a luminous tile with novel functionalities, capable of changing its color and interact with the user. Applications include interior/exterior tile for walls and floors covering, high-efficiency luminaries, and advertising under the form of giant video screens. High overall electrical efficiency of the tile is mandatory, as several millions of square meters are foreseen to be installed each year. Demand is for high uniformity of the illumination of the top tile surface, and for high optical extraction efficiency. These features are achieved by smart light management, using a new approach based on light guiding slab and spatially selective light extraction obtained using both diffusion and/or reflection from the top and bottom interfaces of the optical layer. Planar and edge configurations for the RGB LEDs are considered and compared. A square shape with side length from 20cm to 60cm is considered for the tiles. The electronic circuit layout must optimize the electrical efficiency, and be compatible with low-cost roll-to-roll production on flexible substrates. LED heat management is tackled by using dedicated solutions that allow operation in thermally harsh environment. An approach based on OLEDs has also been considered, still needing improvement on emitted power and ruggedness.

  2. Preparation and Properties of High Refractive Index LED Encapsulation Rubber with Long Life%高折射率、长寿命 LED 灌封胶的制备及性能

    Institute of Scientific and Technical Information of China (English)

    叶文波; 汤胜山

    2015-01-01

    以甲基苯基混合环体、八甲基环四硅氧烷、四甲基四乙烯基环四硅氧烷、四甲基二乙烯基二硅氧烷等为原料制得甲基苯基硅油;以苯基三氯基硅烷、二苯基二氯硅烷、二甲基二氯硅烷和二甲基乙烯基氯硅烷等为原料,制得甲基乙烯基苯基有机硅树脂;以二苯基二甲氧基硅烷、苯基三甲氧基硅烷、四甲基环四硅氧烷为原料制得苯基交联剂。按甲基乙烯基苯基硅油、甲基苯基乙烯基硅树质量比和nSi—H/nVi筛选出符合LED芯片封装基本要求的灌封胶,其折射率为1.5441,操作黏度(25℃)4000~5500 mPa・s,固化后的初始邵尔D硬度为33~37度,可见光(550 nm)透光率大于85%。耐热老化性能测试研究表明,150℃热老化1000 h后,硬度增幅为5度,无黄变现象,在550 nm的透光率大于80%。进一步的光通量测试研究表明,点灯测试1000 h后,该灌封胶的光衰<2%。表明该款灌封胶具有高折射率和较长的应用寿命。%Phenyl methyl silicone fluid was prepared with methylphenyl cyclics mixture, octamethyl cy-clotetrasiloxane, tetramethyl tetravinyl cyclotetrasiloxane, tetramethyl divinyl disiloxane.Then methyl vinyl phenyl silicone resin was prepared with phenyl trichlorosilane, diphenyl dichlorosilane, dimethyl dichloride si-lane and dimethyl vinyl chlorosilane.At last, the phenyl crosslinkers were prepared with diphenyl dimethoxy silane, phenyl trimethoxy silane, and tetramethyl cyclotetrasiloxane.By varying the mass ratios of vinyl methyl phenyl silicone oil and methyl vinyl phenyl silicone resin and Si-H/Vi molar ratio, the optimal composition meeting LED chip packaging was selected.The material has a viscosity of 4000-5500mPa・ s (25 °C) , a re-fractive index of 1.5441 , an initial degree of hardness shore D 33-37°after curing, the visible light trans-mittance (550nm) over 85%.Research of the heat aging testing shows that after thermal

  3. Emotion Induced Blindness Is More Sensitive to Changes in Arousal As Compared to Valence of the Emotional Distractor

    Directory of Open Access Journals (Sweden)

    Divita Singh

    2017-08-01

    Full Text Available Emotion Induced Blindness (EIB refers to the impairment in the identification of a neutral target image that follows a threatening or fearful distractor image. It has been suggested that valence plays a significant role in driving the perceptual impairment in EIB. Recent findings from the literature suggest that arousal has a very important role in biasing early cognitive functions. Hence, in the present study, we systematically investigate the role of valence (Experiment 1 and arousal (Experiment 2 in determining the impairment in EIB. The results suggest that when valence is controlled for, the stimuli with higher arousal level lead to greater impairment in target detection. Moreover, under high arousal condition, both positive and negative stimuli lead to significantly greater impairment in target detection. Present study suggests that impairment in EIB is sensitive to the arousal component of the emotional image as compared to valence. The arousal biased competition account that explains the effect of arousal on cognitive processing can sufficiently explains the current results.

  4. The insula modulates arousal-induced reluctance to try novel tastes through adrenergic transmission in the rat

    Science.gov (United States)

    Rojas, Sebastián; Diaz-Galarce, Raúl; Jerez-Baraona, Juan Manuel; Quintana-Donoso, Daisy; Moraga-Amaro, Rodrigo; Stehberg, Jimmy

    2015-01-01

    Reluctance to try novel tastes (neophobia) can be exacerbated in arousing situations, such as when children are under social stress or in rodents, when the new taste is presented in a high arousal context (HA) compared to a low arousal context (LA). The present study aimed at determining whether adrenergic transmission at the Insula regulates the reluctance to try novel tastes induced by arousing contexts. To this end, a combination of systemic and intra-insular manipulations of adrenergic activity was performed before the novel taste (saccharin 0.1%) was presented either in LA or HA contexts in rats. Our results show that systemic adrenergic activity modulates reluctance to try novel tastes. Moreover, intra-insular microinjections of propranolol or norepinephrine (NE) were found to modulate the effects of arousing contexts on reluctance to try novel tastes. Finally, intra-insular propranolol blocked epinephrine-induced increased reluctance, while intra-insular NE blocked oral propranolol-induced decreases in reluctance and increased the reluctance to try novel tastes presented in low arousing contexts. In conclusion, our results suggest that the insula is a critical site for regulating the effects of arousal in the reluctance to try novel tastes via the adrenergic system. PMID:26175672

  5. The Insula modulates arousal-induced reluctance to try novel tastes through adrenergic transmission in the rat

    Directory of Open Access Journals (Sweden)

    Sebastián Andrés Rojas

    2015-06-01

    Full Text Available Reluctance to try novel tastes (neophobia can be exacerbated in arousing situations, such as when children are under social stress or in rodents, when the new taste is presented in a high arousal context (HA compared to a low arousal context (LA. The present study aimed at determining whether adrenergic transmission at the Insula regulates the reluctance to try novel tastes induced by arousing contexts. To this end, a combination of systemic and intra-insular manipulations of adrenergic activity was performed before the novel taste (saccharin 0.1% was presented either in LA or HA contexts in rats. Our results show that systemic adrenergic activity modulates reluctance to try novel tastes. Moreover, intra-insular microinjections of propranolol or norepinephrine were found to modulate the effects of arousing contexts on reluctance to try novel tastes. Finally, intra-insular propranolol blocked epinephrine-induced increased reluctance, while intra-insular norepinephrine blocked oral propranolol-induced decreases in reluctance and increased the reluctance to try novel tastes presented in low arousing contexts. In conclusion, our results suggest that the insula is a critical site for regulating the effects of arousal in the reluctance to try novel tastes via the adrenergic system.

  6. The Rewarding Aspects of Music Listening Are Related to Degree of Emotional Arousal

    Science.gov (United States)

    Salimpoor, Valorie N.; Benovoy, Mitchel; Longo, Gregory; Cooperstock, Jeremy R.; Zatorre, Robert J.

    2009-01-01

    Background Listening to music is amongst the most rewarding experiences for humans. Music has no functional resemblance to other rewarding stimuli, and has no demonstrated biological value, yet individuals continue listening to music for pleasure. It has been suggested that the pleasurable aspects of music listening are related to a change in emotional arousal, although this link has not been directly investigated. In this study, using methods of high temporal sensitivity we investigated whether there is a systematic relationship between dynamic increases in pleasure states and physiological indicators of emotional arousal, including changes in heart rate, respiration, electrodermal activity, body temperature, and blood volume pulse. Methodology Twenty-six participants listened to self-selected intensely pleasurable music and “neutral” music that was individually selected for them based on low pleasure ratings they provided on other participants' music. The “chills” phenomenon was used to index intensely pleasurable responses to music. During music listening, continuous real-time recordings of subjective pleasure states and simultaneous recordings of sympathetic nervous system activity, an objective measure of emotional arousal, were obtained. Principal Findings Results revealed a strong positive correlation between ratings of pleasure and emotional arousal. Importantly, a dissociation was revealed as individuals who did not experience pleasure also showed no significant increases in emotional arousal. Conclusions/Significance These results have broader implications by demonstrating that strongly felt emotions could be rewarding in themselves in the absence of a physically tangible reward or a specific functional goal. PMID:19834599

  7. Alexithymia predicts arousal-based processing deficits and discordance between emotion response systems during emotional imagery.

    Science.gov (United States)

    Peasley-Miklus, Catherine E; Panayiotou, Georgia; Vrana, Scott R

    2016-03-01

    Alexithymia is believed to involve deficits in emotion processing and imagery ability. Previous findings suggest that it is especially related to deficits in processing the arousal dimension of emotion, and that discordance may exist between self-report and physiological responses to emotional stimuli in alexithymia. The current study used a well-established emotional imagery paradigm to examine emotion processing deficits and discordance in participants (N = 86) selected based on their extreme scores on the Toronto Alexithymia Scale-20. Physiological (skin conductance, heart rate, and corrugator and zygomaticus electromyographic responses) and self-report (valence, arousal ratings) responses were monitored during imagery of anger, fear, joy, and neutral scenes and emotionally neutral high arousal (action) scenes. Results from regression analyses indicated that alexithymia was largely unrelated to responses on valence-based measures (facial electromyography, valence ratings), but that it was related to arousal-based measures. Specifically, alexithymia was related to higher heart rate during neutral and lower heart rate during fear imagery. Alexithymia did not predict differential responses to action versus neutral imagery, suggesting specificity of deficits to emotional contexts. Evidence for discordance between physiological responses and self-report in alexithymia was obtained from within-person analyses using multilevel modeling. Results are consistent with the idea that alexithymic deficits are specific to processing emotional arousal, and suggest difficulties with parasympathetic control and emotion regulation. Alexithymia is also associated with discordance between self-reported emotional experience and physiological response to emotion, consistent with prior evidence. (c) 2016 APA, all rights reserved).

  8. New Research Frontier of High Power LED Lamp Cooling System%LED照明散热技术现状及进展

    Institute of Scientific and Technical Information of China (English)

    勾昱君; 刘中良

    2012-01-01

    对当前大功率发光二极管(LED)照明散热技术的现状进行了介绍。针对LED照明热源的特点,开发了一系列具有特殊翅片结构的热管换热器,并对不同工况下各种热管的散热能力进行了测试,测试结果表明,所研发的新型热管换热器散热能力比普通热管换热器有明显提高,结构更加紧凑,其中,外翻形翅片结构的热管换热器散热能力最好,可为LED照明散热技术的发展和研究提供参考。%Various cooling systems and methods applied to high power LED lamps are introduced.According to the characteristics of high power LED lamps,a series of heat pipes with specific fin structures are developed and tested under different conditions.Test results show that the new heat pipe heat exchangers feature higher efficiency of heat dissipation and more compact construction than the conventional heat pipe heat exchangers and that the new heat exchanger with outwards-radiate fins has the best heat dissipation performance.The research findings can provide reference for the development of LED lamp cooling technology.

  9. Can sustained arousal explain the Chronic Fatigue Syndrome?

    Directory of Open Access Journals (Sweden)

    Eriksen Hege R

    2009-02-01

    Full Text Available Abstract We present an integrative model of disease mechanisms in the Chronic Fatigue Syndrome (CFS, unifying empirical findings from different research traditions. Based upon the Cognitive activation theory of stress (CATS, we argue that new data on cardiovascular and thermoregulatory regulation indicate a state of permanent arousal responses – sustained arousal – in this condition. We suggest that sustained arousal can originate from different precipitating factors (infections, psychosocial challenges interacting with predisposing factors (genetic traits, personality and learned expectancies (classical and operant conditioning. Furthermore, sustained arousal may explain documented alterations by establishing vicious circles within immunology (Th2 (humoral vs Th1 (cellular predominance, endocrinology (attenuated HPA axis, skeletal muscle function (attenuated cortical activation, increased oxidative stress and cognition (impaired memory and information processing. Finally, we propose a causal link between sustained arousal and the experience of fatigue. The model of sustained arousal embraces all main findings concerning CFS disease mechanisms within one theoretical framework.

  10. Sensitization, subjective health complaints, and sustained arousal.

    Science.gov (United States)

    Ursin, H; Eriksen, H R

    2001-03-01

    The purpose of this presentation is to discuss the possibility that sensitization is a psychobiological mechanism underlying not only multiple chemical sensitivity (MCS), but a much more general cluster of illness, referred to as "subjective health complaints". Sustained arousal, or sustained "stress" responses, may be an important factor for the development of these conditions. Patients with subjective complaints without objective changes are sometimes referred to as having "fashionable diagnoses" or "unexplained symptoms". They may be given diagnoses like MCS, epidemic fatigue, chronic fatigue syndrome, burnout, stress, a variety of intoxications, environmental illness, radiation, multiple chemical hypersensitivity, food intolerance, functional dyspepsia, irritable bowel, myalgic encephalitis, postviral syndrome, yuppie flu, fibromyalgia, or vital exhaustion. One issue is whether this is one general condition or separate entities. Another issue is whether sensitization may be the psychobiological mechanism for most or all of these conditions. Finally, is it likely that sustained arousal may facilitate the development of sensitization in some or many neural circuits? In this review, the main emphasis will be on musculoskeletal pain. This is the most frequent and most expensive condition for sickness compensation and disability. The comorbidity of other complaints, however, will also be taken into account.

  11. Nocturnal Hypermotor Activity during Apnea-Related Arousals

    Science.gov (United States)

    Hoque, Romy; DelRosso, Lourdes M.

    2016-01-01

    We present a case of a 50-year-old patient who exhibits nocturnal hypermotor activity occurring exclusively during apnea-related arousals consisting of repetitive lower extremity hip-flapping. This movement is unusual and reflects a new form of lower extremity movement associated with apnea-related arousals. Citation: Hoque R, DelRosso LM. Nocturnal hypermotor activity during apnea-related arousals. J Clin Sleep Med 2016;12(9):1305–1307. PMID:27092691

  12. Effect of p-GaN layer grown with H2 carrier gas on wall-plug efficiency of high-power LEDs

    Science.gov (United States)

    Lu, Kuan Fu; Lin, Tien Kun; Liou, Jian Kai; Yang, Chyi Da; Lee, Chong Yi; Tsai, Jeng Da

    2017-06-01

    The effect of employing different carrier gases (H2 only and 1:1 vol% N2:H2) in the p-type GaN (p-GaN) layer on the wall-plug efficiency (WPE) of high-power light-emitting diodes (LEDs) is studied. Since GaN crystal could be a two-dimension (2-D) growth mode in H2 ambient, better quality and smoother surface of the p-GaN were obtained. The current spreading performance of the p-GaN layer using H2 alone as the carrier gas was enhanced, resulting in advanced light output power (LOP). In addition, turn-on voltage and dynamic resistance at 500 mA, which can strongly contribute to the WPE, were also reduced by 0.12 V and 0.13 Ω, respectively. The studied device with H2 as the carrier gas in the p-GaN layer (p-H2 layer) exhibits 9.5% and 12.4% improvements in LOP and WPE at 500 mA over the device (N2/H2 = 1:1), as well as significantly better electrostatic discharge robustness. Therefore, the use of a p-H2 layer can effectively improve the performance of GaN-based LEDs for high power applications.

  13. People, clothing, music, and arousal as contextual retrieval cues in verbal memory.

    Science.gov (United States)

    Standing, Lionel G; Bobbitt, Kristin E; Boisvert, Kathryn L; Dayholos, Kathy N; Gagnon, Anne M

    2008-10-01

    Four experiments (N = 164) on context-dependent memory were performed to explore the effects on verbal memory of incidental cues during the test session which replicated specific features of the learning session. These features involved (1) bystanders, (2) the clothing of the experimenter, (3) background music, and (4) the arousal level of the subject. Social contextual cues (bystanders or experimenter clothing) improved verbal recall or recognition. However, recall decreased when the contextual cue was a different stimulus taken from the same conceptual category (piano music by Chopin) that was heard during learning. Memory was unaffected by congruent internal cues, produced by the same physiological arousal level (low, moderate, or high heart rate) during the learning and test sessions. However, recall increased with the level of arousal across the three congruent conditions. The results emphasize the effectiveness as retrieval cues of stimuli which are socially salient, concrete, and external.

  14. Pedunculopontine arousal system physiology-Implications for schizophrenia.

    Science.gov (United States)

    Garcia-Rill, Edgar; D'Onofrio, Stasia; Mahaffey, Susan; Bisagno, Veronica; Urbano, Francisco J

    2015-01-01

    Schizophrenia is characterized by major sleep/wake disturbances including increased vigilance and arousal, decreased slow wave sleep, and increased REM sleep drive. Other arousal-related symptoms include sensory gating deficits as exemplified by decreased habituation of the blink reflex. There is also dysregulation of gamma band activity, suggestive of disturbances in a host of arousal-related mechanisms. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of the disease. Recent discoveries on the physiology of the pedunculopontine nucleus help explain many of these disorders of arousal in, and point to novel therapeutic avenues for, schizophrenia.

  15. Pedunculopontine arousal system physiology—Implications for schizophrenia

    Directory of Open Access Journals (Sweden)

    Edgar Garcia-Rill

    2015-04-01

    Full Text Available Schizophrenia is characterized by major sleep/wake disturbances including increased vigilance and arousal, decreased slow wave sleep, and increased REM sleep drive. Other arousal-related symptoms include sensory gating deficits as exemplified by decreased habituation of the blink reflex. There is also dysregulation of gamma band activity, suggestive of disturbances in a host of arousal-related mechanisms. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of the disease. Recent discoveries on the physiology of the pedunculopontine nucleus help explain many of these disorders of arousal in, and point to novel therapeutic avenues for, schizophrenia.

  16. Eyes wide shopped: shopping situations trigger arousal in impulsive buyers.

    Science.gov (United States)

    Serfas, Benjamin G; Büttner, Oliver B; Florack, Arnd

    2014-01-01

    The present study proposes arousal as an important mechanism driving buying impulsiveness. We examined the effect of buying impulsiveness on arousal in non-shopping and shopping contexts. In an eye-tracking experiment, we measured pupil dilation while participants viewed and rated pictures of shopping scenes and non-shopping scenes. The results demonstrated that buying impulsiveness is closely associated with arousal as response to viewing pictures of shopping scenes. This pertained for hedonic shopping situations as well as for utilitarian shopping situations. Importantly, the effect did not emerge for non-shopping scenes. Furthermore, we demonstrated that arousal of impulsive buyers is independent from cognitive evaluation of scenes in the pictures.

  17. High color rendering index of remote-type white LEDs with multi-layered quantum dot-phosphor films and short-wavelength pass dichroic filters

    Science.gov (United States)

    Yoon, Hee Chang; Oh, Ji Hye; Do, Young Rag

    2014-09-01

    This paper introduces high color rendering index (CRI) white light-emitting diodes (W-LEDs) coated with red emitting (Sr,Ca)AlSiN3:Eu phosphors and yellowish-green emitting AgIn5S8/ZnS (AIS/ZS) quantum dots (QDs) on glass or a short-wavelength pass dichroic filter (SPDF), which transmit blue wavelength regions and reflect yellow wavelength regions. The red emitting (Sr,Ca)AlSiN3:Eu phosphor film is coated on glass and a SPDF using a screen printing method, and then the yellowish-green emitting AIS/ZS QDs are coated on the red phosphor (Sr,Ca)AlSiN3:Eu film-coated glass and SPDF using the electrospray (e-spray) method.To fabricate the red phosphor film, the optimum amount of phosphor is dispersed in a silicon binder to form a red phosphor paste. The AIS/ZS QDs are mixed with dimethylformamide (DMF), toluene, and poly(methyl methacrylate) (PMMA) for the e-spray coating. The substrates are spin-coated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to fabricate a conductive surface. The CRI of the white LEDs is improved through inserting the red phosphor film between the QD layer and the glass substrate. Furthermore, the light intensities of the multi-layered phosphor films are enhanced through changing the glass substrate to the SPDF. The correlated color temperatures (CCTs) vary as a function of the phosphor concentration in the phosphor paste. The optical properties of the yellowish-green AIS/ZS QDs and red (Sr,Ca)AlSiN3:Eu phosphors are characterized using photoluminescence (PL), and the multi-layered QD-phosphor films are measured using electroluminescence (EL) with an InGaN blue LED (λmax = 450 nm) at 60 mA.

  18. The interactive effect of personality, time of day, and caffeine: a test of the arousal model.

    Science.gov (United States)

    Revelle, W; Humphreys, M S; Simon, L; Gilliland, K

    1980-03-01

    The personality dimension of introversion/extraversion is one of the few personality dimensions that can be reliably identified from study to study and investigator to investigator. The importance of this demension within personality theory is due both to the stability of the trait and the influential theory of H. J. Eysenck. The basic assumption in Eysenck's theory of introversion/extraversion is that the personality differences between introverts and extraverts reflect some basic difference in the resting level of cortical arousal or activation. Assuming that there is a curvilinear relationship (an inverted U) between levels of stress and performance leads to a test of this arousal theory. That is, moderate increases in stress should hinder the performance of introverts who are presumably already highly aroused. However, the same moderate increase in stress might help the performance of the presumably underaroused extraverts. Revelle, Amaral, and Turriff reported that the administration of moderate doses of caffeine hindered the performance of introverts and helped the performance of extraverts on a cognitive task similar to the verbal test of the Graduate Record Examination. Assuming that caffeine increases arousal, this interaction between introversion/extraversion and drug condition supports Eysenck's theory. This interaction was explored in a series of experiments designed to replicate, extend, and test the generality of the original finding. The interaction between personality and drug condition was replicated and extended to additional cognitive performance tasks. However, these interactions were affected by time of day and stage of practice, and the subscales of introversion/extraversion, impulsivity, and sociability, were differentially affected. In the morning of the first day, low impulsives were hindered and high impulsives helped by caffeine. This pattern reversed in the evening of the first day, and it reversed again in the evening of Day 2. We

  19. Fabrication of high color rendering index white LED using Cd-free wavelength tunable Zn doped CuInS2 nanocrystals.

    Science.gov (United States)

    Chung, Wonkeun; Jung, Hyunchul; Lee, Chang Hun; Kim, Sung Hyun

    2012-10-22

    Highly luminescent Cd-free Zn doped CuInS(2) nanocrystals (ZCIS NCs) were synthesized, and their properties were evaluated using X-ray diffraction, Raman, UV, and photoluminescence. The crystal structure of the ZCIS NCs was similar to the zinc blende, and the lattice constant decreased with increasing Zn concentration. By incorporation of Zn, the emission wavelength was tuned from 536 to 637 nm with concomitant enhancement of the quantum yield up to 45%. A white light emitting diodes, integrating dual ZCIS NCs (λ(em) = 567, and 617 nm) and a 460 nm InGaN LED, exhibited a high color rendering index of 84.1 with a warm color temperature of 4256.2K. The CIE-1931 chromaticity coordinates were slightly shifted from (0.3626, 0.3378) at 20 mA to (0.3480, 0.3206) at 50 mA.

  20. LED minilidar for Mars rover

    Science.gov (United States)

    Shiina, Tatsuo; Yamada, Sonoko; Senshu, Hiroki; Otobe, Naohito; Hashimoto, George; Kawabata, Yasuhiro

    2016-10-01

    A mini-lidar to observe the activity of Martian atmosphere is developed. The 10cm-cube LED mini-lidar was designed to be onboard a Mars rover. The light source of the mini-lidar is a high powered LED of 385nm. LED was adopted as light source because of its toughness against circumference change and physical shock for launch. The pulsed power and the pulse repetition frequency of LED beam were designed as 0.75W (=7.5nJ/10ns) and 500kHz, respectively. Lidar echoes were caught by the specially designed Cassegrain telescope, which has the shorter telescope tube than the usual to meet the 10cm-cube size limit. The high-speed photon counter was developed to pursue to the pulse repetition frequency of the LED light. The measurement range is no shorter than 30m depending back-ground condition. Its spatial resolution was improved as 0.15m (=1ns) by this photon counter. The demonstrative experiment was conducted at large wind tunnel facility of Japan Meteorological Agency. The measurement target was smoke of glycerin particles. The smoke was flowed in the wind tunnel with wind speed of 0 - 5m. Smoke diffusion and its propagation due to the wind flow were observed by the LED mini-lidar. This result suggests that the developed lidar can pursue the structure and the motion of dust devil of >2m.

  1. Dansk LED - Museumsbelysning

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Thorseth, Anders

    Projektet har til formål at anvende dansk forskning inden for optik og lys til at realisere innovative energieffektive LED lyssystemer til museumsbranchen.......Projektet har til formål at anvende dansk forskning inden for optik og lys til at realisere innovative energieffektive LED lyssystemer til museumsbranchen....

  2. Personality change at the intersection of autonomic arousal and stress.

    Science.gov (United States)

    Hart, Daniel; Eisenberg, Nancy; Valiente, Carlos

    2007-06-01

    We hypothesized that personality change in children can be predicted by the interaction of family risk with susceptibility to autonomic arousal and that children characterized by both high-risk families and highly reactive autonomic nervous systems tend to show maladaptive change. This hypothesis was tested in a 6-year longitudinal study in which personality-type prototypicality, problem behavior, and negative emotional intensity were measured at 2-year intervals. The results indicated that children who both had exaggerated skin conductance responses (a measure of autonomic reactivity) and were living in families with multiple risk factors were most likely to develop an undercontrolled personality type and to exhibit increases in problem behavior and negative emotional intensity. The implications of the results for understanding personality change are discussed.

  3. Goniometric characterization of LED based greenhouse lighting

    DEFF Research Database (Denmark)

    Thorseth, Anders; Lindén, Johannes; Corell, Dennis Dan

    2015-01-01

    This paper describes a demonstration of goniospectroradiometry for characterizations of new light emitting diode (LED) based luminaries for enhanced photosynthesis in greenhouses. It highlights the differences between measurement of the traditional high pressure sodium (HPS) luminaries and the LED...

  4. The distribution of InCl sub x compounds in model polymeric LEDs A combined low and high-energy ion beam analysis study

    CERN Document Server

    Reijme, M A; Simons, D P L; Schok, M; Ijzendoorn, L J V; Brongersma, H H; De Voigt, M J A

    2002-01-01

    A combination of low- and high-energy ion beam analysis techniques was used to determine the distribution of indium chloride compounds in model polymeric light-emitting diodes (p-LEDs). Parts of polymeric LEDs (polydialkoxyphenylenevinylene (OC sub 1 C sub 1 sub 0 -PPV) on indium-tin-oxide (ITO) substrates) were exposed to a HCl/Ar flow to simulate the processes occurring during conversion of precursor PPVs and acid treatment of polymers. Samples with variable exposure times as well as pristine samples were studied with Rutherford backscattering spectrometry (RBS), low energy ion scattering (LEIS), X-ray photoelectron spectroscopy (XPS) and particle induced X-ray emission (PIXE). The RBS measurements show that after HCl exposure indium is distributed throughout the OC sub 1 C sub 1 sub 0 -PPV layer. LEIS and XPS measurements indicate that the indium and chlorine are present at the outermost surface of the OC sub 1 C sub 1 sub 0 -PPV layer. PIXE measurements in combination with the RBS data demonstrate that th...

  5. Effects of high-fidelity patient simulation led clinical reasoning course: Focused on nursing core competencies, problem solving, and academic self-efficacy.

    Science.gov (United States)

    Lee, JuHee; Lee, Yoonju; Lee, Senah; Bae, Juyeon

    2016-01-01

    To examine the effects of high-fidelity patient simulation (HFPS) led clinical reasoning course among undergraduate nursing students. A quasi-experimental study of non-equivalent control group pretest-post test design was applied. A total of 49 senior nursing students participated in this study. The experimental group consisted of the students who took the "clinical reasoning" course (n = 23) while the control group consisted of students who did not (n = 26). Self-administered scales including the nursing core competencies, problem solving, academic self-efficacy, and Kolb learning style inventory were analyzed quantitatively using SPSS version 20.0. Data analysis was conducted using one-way ancova due to a significant difference in nursing core competencies between the experimental group and control group. There was a significant improvement in nursing core competencies in the experimental group (F = 7.747, P = 0.008). The scores of problem solving and academic self-efficacy were higher in the experimental group after the HFPS led clinical reasoning course without statistical difference. There is a need for the development of effective instructional methods to improve learning outcomes in nursing education. Future research is needed related to simulation education as well as management strategies so that learning outcomes can be achieved within different students' learning style. © 2015 The Authors. Japan Journal of Nursing Science © 2015 Japan Academy of Nursing Science.

  6. Cerebral activation associated with visually evoked sexual arousal in the limbic system: functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eun, Sung Jong; Kong, Gwang Woo; Kim, Hyung Joong; Seo, Jeong Jin; Kang, Heoung Keun; Cho, Ki Hyun; Yoon, Ka Hyun [School of Medicine, Chonnam National Univ., Kwangju (Korea, Republic of); Kim, Kyung Yo [Wonkwang Univ., Iksan (Korea, Republic of)

    2004-08-01

    To identify the brain centers associated with visually evoked sexual arousal in the human brain, and to investigate the neural mechanism for sexual arousal using functional MRI (fMRI). A total of 20 sexually potent volunteers consisting of 10 males (mean age: 24) and 10 females (mean age: 23) underwent fMRI on a 1.5T MR scanner (GE Signa Horizon). The fMRI data were obtained from 7 slices (10 mm slice thickness) parallel to the AC-PC (anterior commissure and posterior commissure) line, giving a total of 511 MR images. The sexual stimulation consisted of a 1-minute rest with black screen, followed by a 4-minute stimulation by an erotic video film, and concluded with a 2-minute rest. The brain activation maps and their quantification were analyzed by the statistical parametric mapping (SPM 99) program. The brain activation regions associated with visual sexual arousal in the limbic system are the posterior cingulate gyrus, parahippocampal gyrus, hypothalamus, medial cingulate gyrus, thalamus, amygdala, anterior cingulate gyrus, insula, hippocampus, caudate nucleus, globus pallidus and putamen. Especially, the parahippocampal gyrus, cingulate gyrus, thalamus and hypothalamus were highly activated in comparison with other areas. The overall activities of the limbic lobe, diencephalon, and basal ganglia were 11.8%, 10.5%, and 3.4%, respectively. In the correlation test between brain activity and sexual arousal, the hypothalamus and thalamus showed positive correlation, but the other brain areas showed no correlation. The fMRI is useful to quantitatively evaluate the cerebral activation associated with visually evoked, sexual arousal in the human brain. This result may be helpful by providing clinically valuable information on sexual disorder in humans as well as by increasing the understanding of the neuroanatomical correlates of sexual arousal.

  7. Effects of Arousal and Context on Recognition Memory for Emotional Pictures in Younger and Older Adults.

    Science.gov (United States)

    Wang, Yang; Yang, Jiongjiong

    2017-01-01

    Background/Study Context: Previous studies found that older adults tend to remember more positive than negative information (i.e., positivity bias), leading to an age-related positivity effect. However, the extent to which factors of arousal and contextual information influence the positivity bias in older adults remains to be determined. In this study, 27 Chinese younger adults (20.00 ± 1.75 years) and 33 Chinese older adults (70.76 ± 5.49) learned pictures with negative, positive, and neutral valences. Half of the pictures had a human context, and the other half did not. In addition, emotional dimensions of negative and positive pictures were divided into high-arousal and low-arousal. The experimental task was to provide old/new recognition and confidence rating judgments. Both groups of subjects showed the positivity bias for low-arousal pictures, but the positivity bias was restricted to low-arousal pictures without the human context in older adults. In addition, the positivity bias was mainly driven by the recollection process in younger adults, and it was mainly driven by both the recollection and familiarity processes in older adults. The recognition of the nonhuman positive pictures was correlated with cognitive control abilities, but the recognition of pictures with human contexts was correlated with general memory abilities in older adults. This study highlights the importance of arousal and contextual information in modulating emotional memory in younger and older adults. It suggests that there are different mechanisms for memorizing pictures with and without human contexts in older adults.

  8. The amplitude and phase precision of 40 Hz auditory steady-state response depend on the level of arousal

    DEFF Research Database (Denmark)

    Griskova, Inga; Mørup, Morten; Parnas, Josef

    2007-01-01

    The aim of this study was to investigate, in healthy subjects, the modulation of amplitude and phase precision of the auditory steady-state response (ASSR) to 40 Hz stimulation in two resting conditions varying in the level of arousal. Previously, ASSR measures have shown to be affected by the le......The aim of this study was to investigate, in healthy subjects, the modulation of amplitude and phase precision of the auditory steady-state response (ASSR) to 40 Hz stimulation in two resting conditions varying in the level of arousal. Previously, ASSR measures have shown to be affected...... it pertinent to know the effects of fluctuations in arousal on passive response to gamma-range stimulation. In nine healthy volunteers trains of 40 Hz click stimuli were applied during two conditions: in the "high arousal" condition subjects were sitting upright silently reading a book of interest; in the "low...

  9. Leader Affective Displays and Attributions of Charisma: The Role of Arousal

    NARCIS (Netherlands)

    F.J.A. Damen (Frederic); D.L. van Knippenberg (Daan); B. van Knippenberg (Barbara)

    2007-01-01

    textabstractResearch suggests that leader displays of positive affect are conducive to attributions of charisma. We qualify and extend this conclusion by arguing that this mainly holds for displays of positive affect that are associated with high levels of arousal. Results of a scenario experiment a

  10. Psychopathology and Deviant Sexual Arousal in Incarcerated Sexual Offenders.

    Science.gov (United States)

    Serin, Ralph C.; And Others

    1994-01-01

    Investigates the relationship between psychopathology and deviant sexual arousal in sexual offenders (n=65), with approximately equal numbers of rapists and child molesters. Differentiating between rapists, extrafamilial pedophiles, and incest offenders revealed that the relationship between psychopathology and arousal was most apparent for…

  11. Emotional Arousal Does Not Enhance Association-Memory

    Science.gov (United States)

    Madan, Christopher R.; Caplan, Jeremy B.; Lau, Christine S. M.; Fujiwara, Esther

    2012-01-01

    Emotionally arousing information is remembered better than neutral information. This enhancement effect has been shown for memory for items. In contrast, studies of association-memory have found both impairments and enhancements of association-memory by arousal. We aimed to resolve these conflicting results by using a cued-recall paradigm combined…

  12. Age differences in recall and liking of arousing television commercials

    NARCIS (Netherlands)

    van der Goot, M.J.; van Reijmersdal, E.A.; Kleemans, M.

    2015-01-01

    This article examines whether there are differences between older and younger adults in recall and liking of arousing television commercials. As hypothesized, the experiment demonstrated that older adults remembered brands and products in calm commercials better than in arousing commercials, and

  13. Depression, Fatigue, and Pre-Sleep Arousal: A Mediation Model

    Science.gov (United States)

    Karlson, Cynthia W.; Stevens, Natalie R.; Olson, Christy A.; Hamilton, Nancy A.

    2010-01-01

    Fatigue is a common and debilitating symptom of clinical depression; however, the causes are not well understood. The present study was designed to test the hypotheses that subjective sleep, objective sleep, and arousal in the pre-sleep state would mediate the relationship between depression status and fatigue. Sleep, pre-sleep arousal, and…

  14. The level of arousal modulates P50 peak amplitude

    DEFF Research Database (Denmark)

    Griskova-Bulanova, Inga; Paskevic, Jevgenij; Dapsys, Kastytis;

    2011-01-01

    We aimed to evaluate the effect of arousal level in healthy subjects on P50 potential, as the variation in the level of arousal may be a source of variance in the recordings as well as it may provide additional information about the pathology under study. Eleven healthy volunteers participated in...

  15. Age differences in recall and liking of arousing television commercials

    NARCIS (Netherlands)

    Goot, M.J. van der; Reijmersdal, E.A. van; Kleemans, M.

    2015-01-01

    This article examines whether there are differences between older and younger adults in recall and liking of arousing television commercials. As hypothesized, the experiment demonstrated that older adults remembered brands and products in calm commercials better than in arousing commercials, and the

  16. Menstrual cycle phase and sexual arousability in women

    NARCIS (Netherlands)

    A.K. Slob (Koos); M. Ernste (M.); J.J. Van der Werff ten Bosch (Jacob)

    1991-01-01

    markdownabstract__Abstract__ Sexual arousability of women has not been consistently found to vary significantly over phases of the menstrual cycle. We studied changes in the temperature of a labium minus and subjective sexual and genital arousal recorded on semantic scales while watching erotic

  17. Differential effects of arousal in positive and negative autobiographical memories.

    Science.gov (United States)

    Ford, Jaclyn Hennessey; Addis, Donna Rose; Giovanello, Kelly S

    2012-01-01

    Autobiographical memories are characterised by a range of emotions and emotional reactions. Recent research has demonstrated that differences in emotional valence (positive vs. negative emotion) and arousal (the degree of emotional intensity) differentially influence the retrieved memory narrative. Although the mnemonic effects of valence and arousal have both been heavily studied, it is currently unclear whether the effects of emotional arousal are equivalent for positive and negative autobiographical events. In the current study, multilevel models were used to examine differential effects of emotional valence and arousal on the richness of autobiographical memory retrieval both between and within subjects. Thirty-four young adults were asked to retrieve personal autobiographical memories associated with popular musical cues and to rate the valence, arousal and richness of these events. The multilevel analyses identified independent influences of valence and intensity upon retrieval characteristics at the within- and between-subject levels. In addition, the within-subject interactions between valence and arousal highlighted differential effects of arousal for positive and negative memories. These findings have important implications for future studies of emotion and memory, highlighting the importance of considering both valence and arousal when examining the role emotion plays in the richness of memory representation.

  18. Menstrual cycle phase and sexual arousability in women

    NARCIS (Netherlands)

    A.K. Slob (Koos); M. Ernste (M.); J.J. Van der Werff ten Bosch (Jacob)

    1991-01-01

    markdownabstract__Abstract__ Sexual arousability of women has not been consistently found to vary significantly over phases of the menstrual cycle. We studied changes in the temperature of a labium minus and subjective sexual and genital arousal recorded on semantic scales while watching erotic vid

  19. Spectroradiometry for LED characterization

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten

    Radiospectroscopy is the absolute measurement of electromagnetic radiation within a specific wavelength range. For characterization of LED components, light sources and lamps we are interested in absolute measurement of the spectral power distribution, SPD, in the visible and near infrared region....... Using integrating spheres for light collection setups for absolute total spectral flux is realized at the LED Light Lab at DTU Fotonik, Risø Campus. From these, both total radiant and luminous flux is determined and through electrical power measurement also the efficiency is determined. From the SPD...... colorimetric quantities like color coordinates, color temperature and color rendering indices are calculated. The facilities and special issues concerning LED measurements compared to traditional light sources are explained and examples from the “LED lighting quality program”, a project supported by the Danish...

  20. Modeling LED street lighting.

    Science.gov (United States)

    Moreno, Ivan; Avendaño-Alejo, Maximino; Saucedo-A, Tonatiuh; Bugarin, Alejandra

    2014-07-10

    LED luminaires may deliver precise illumination patterns to control light pollution, comfort, visibility, and light utilization efficiency. Here, we provide simple equations to determine how the light distributes in the streets. In particular, we model the illuminance spatial distribution as a function of Cartesian coordinates on a floor, road, or street. The equations show explicit dependence on the luminary position (pole height and arm length), luminary angle (fixture tilt), and the angular intensity profile (radiation pattern) of the LED luminary. To achieve this, we propose two mathematical representations to model the sophisticated intensity profiles of LED luminaries. Furthermore, we model the light utilization efficiency, illumination uniformity, and veiling luminance of glare due to one or several LED streetlamps.

  1. LEDs Are Diodes.

    Science.gov (United States)

    Lisensky, George C.; Condren, S. Michael; Widstrand, Cynthia G.; Breitzer, Jonathan; Ellis, Arthur B.

    2001-01-01

    Describes an activity comparing incandescent bulbs and LEDs powered by dc and ac voltage sources to illustrate properties of matter and the interactions of energy and matter. Includes both instructor information and student activity sheet. (Author/YDS)

  2. Strategies of arousal control: biofeedback, meditation, and motivation.

    Science.gov (United States)

    Cuthbert, B; Kristeller, J; Simons, R; Hodes, R; Lang, P J

    1981-12-01

    A series of four experiments assessed the effects of instructions to lower heart rate on heart rate change and general arousal reduction. Various conditions of biofeedback, cognitive load, incentive, knowledge of results, and the experimenter-subject relationship were tested. Experiment 1 compared physiological responses to the delivery of direct organ feedback (i.e., heart rate) with responses to electromyographic biofeedback from the frontalis muscle area and with responses to a nonfeedback tracking task. The results suggest that neither heart rate nor muscle tension feedback is an especially powerful method for achieving sustained reductions in heart rate. Furthermore, although some specificity of physiologic pattern is apparent, biofeedback is no more effective in lowering general activation level than simple instructions to relax accompanied by a general knowledge of results. The second experiment was designed to assess the role of cognitive load in arousal reduction. Heart rate biofeedback was compared with a procedure involving minimal external information processing--the secular meditation exercise of Wallace and Benson. The results indicated a clear superiority for the meditation strategy in effecting reductions in cardiac rate and lowering activation. However, in a third experiment, meditation subjects lowered heart rate much less than observed in the previous study, and this time the reduction did not exceed that achieved by feedback subjects. Subsequent analysis suggested that the quality of the subject-experimenter relationship (active-supportive vs. formal-distant) was a significant variable in accounting for outcome differences. The above hypothesis was supported by a fourth experiment. Under conditions of high subject-experimenter involvement, the superior meditation performance of Experiment 2 was reproduced; under low-involvement conditions the Experiment 3 result of no difference between training groups was obtained. The findings suggest that the

  3. RS-232 Led Board

    CERN Document Server

    Tskhvaradze, Vladimir

    2007-01-01

    This article demonstrates how to develop a Microchip PIC16F84 based device that supports RS-232 interface with PC. Circuit (LED Board) design and software development will be discussed. PicBasic Pro Compiler from microEngineering Labs, Inc. is used for PIC programming. Development of LED Board Control Console using C/C++ is also briefly discussed. The project requires basic work experience with Microchip PICs, serial communication and programming.

  4. A novel imaging system of optical detection on cancers and tissues in gastrointestinal endoscope using high-color-rendering white and color tunable LEDs

    Science.gov (United States)

    Nishikawa, Jun; Taguchi, Tsunemasa; Uchida, Yuji; Kurai, Satoshi; Yanai, Hideo; Kiyotoki, Shu; Okamoto, Takeshi; Higaki, Shingo; Sakaida, Isao

    2010-02-01

    The use of white or color tunable LEDs (light-emitting diodes), which can replace a large light source apparatus and light-guiding fiber bundle, enable the miniaturization of the whole endoscope system and remove constraints on the design of its shape. We have developed a novel white LED for a new experimental prototype LED-illuminated gastrointestinal endoscope having the color rendering in the clinically important red range at around 600 nm.­

  5. Memory recall in arousing situations – an emotional von Restorff effect?

    Directory of Open Access Journals (Sweden)

    Hasselbach Simone

    2006-07-01

    Full Text Available Abstract Background Previous research has demonstrated a relationship between memory recall and P300 amplitude in list learning tasks, but the variables mediating this P300-recall relationship are not well understood. In the present study, subjects were required to recall items from lists consisting of 12 words, which were presented in front of pictures taken from the IAPS collection. One word per list is made distinct either by font color or by a highly arousing background IAPS picture. This isolation procedure was first used by von Restorff. Brain potentials were recorded during list presentation. Results Recall performance was enhanced for color but not for emotional isolates. Event-related brain potentials (ERP showed a more positive P300-component for recalled non-isolated words and color-isolated words, compared to the respective non-remembered words, but not for words isolated by arousing background. Conclusion Our findings indicate that it is crucial to take emotional mediator variables into account, when using the P300 to predict later recall. Highly arousing environments might force the cognitive system to interrupt rehearsal processes in working memory, which might benefit transfer into other, more stable memory systems. The impact of attention-capturing properties of arousing background stimuli is also discussed.

  6. Memory recall in arousing situations – an emotional von Restorff effect?

    Science.gov (United States)

    Wiswede, Daniel; Rüsseler, Jascha; Hasselbach, Simone; Münte, Thomas F

    2006-01-01

    Background Previous research has demonstrated a relationship between memory recall and P300 amplitude in list learning tasks, but the variables mediating this P300-recall relationship are not well understood. In the present study, subjects were required to recall items from lists consisting of 12 words, which were presented in front of pictures taken from the IAPS collection. One word per list is made distinct either by font color or by a highly arousing background IAPS picture. This isolation procedure was first used by von Restorff. Brain potentials were recorded during list presentation. Results Recall performance was enhanced for color but not for emotional isolates. Event-related brain potentials (ERP) showed a more positive P300-component for recalled non-isolated words and color-isolated words, compared to the respective non-remembered words, but not for words isolated by arousing background. Conclusion Our findings indicate that it is crucial to take emotional mediator variables into account, when using the P300 to predict later recall. Highly arousing environments might force the cognitive system to interrupt rehearsal processes in working memory, which might benefit transfer into other, more stable memory systems. The impact of attention-capturing properties of arousing background stimuli is also discussed. PMID:16863589

  7. Effects of valence and arousal on emotional word processing are modulated by concreteness: Behavioral and ERP evidence from a lexical decision task.

    Science.gov (United States)

    Yao, Zhao; Yu, Deshui; Wang, Lili; Zhu, Xiangru; Guo, Jingjing; Wang, Zhenhong

    2016-12-01

    We investigated whether the effects of valence and arousal on emotional word processing are modulated by concreteness using event-related potentials (ERPs). The stimuli included concrete words (Experiment 1) and abstract words (Experiment 2) that were organized in an orthogonal design, with valence (positive and negative) and arousal (low and high) as factors in a lexical decision task. In Experiment 1, the impact of emotion on the effects of concrete words mainly resulted from the contribution of valence. Positive concrete words were processed more quickly than negative words and elicited a reduction of N400 (300-410ms) and enhancement of late positive complex (LPC; 450-750ms), whereas no differences in response times or ERPs were found between high and low levels of arousal. In Experiment 2, the interaction between valence and arousal influenced the impact of emotion on the effects of abstract words. Low-arousal positive words were associated with shorter response times and a reduction of LPC amplitudes compared with high-arousal positive words. Low-arousal negative words were processed more slowly and elicited a reduction of N170 (140-200ms) compared with high-arousal negative words. The present study indicates that word concreteness modulates the contributions of valence and arousal to the effects of emotion, and this modulation occurs during the early perceptual processing stage (N170) and late elaborate processing stage (LPC) for emotional words and at the end of all cognitive processes (i.e., reflected by response times). These findings support an embodied theory of semantic representation and help clarify prior inconsistent findings regarding the ways in which valance and arousal influence different stages of word processing, at least in a lexical decision task.

  8. Arousal and cortisol interact in modulating memory consolidation in healthy young men.

    Science.gov (United States)

    Kuhlmann, Sabrina; Wolf, Oliver T

    2006-02-01

    Animal studies indicate that adrenal glucocorticoids enhance memory consolidation while impairing memory retrieval. In humans, beneficial effects on consolidation have been observed infrequently. In the current double-blind study, subjects (N = 29) received placebo or cortisol (30 mg) 10 min before viewing emotionally arousing or neutral pictures. Cortisol treatment had no effects on immediate recall. In the 24-hr delayed recall condition, cortisol led to an enhanced emotional memory facilitation because of decreased neutral and increased emotional memory recall. No effects of cortisol treatment were observed for recognition memory or mood. Results support the notion that glucocorticoids specifically enhance the consolidation of emotional material.

  9. Light Emitting Diodes (LEDs)

    Science.gov (United States)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique, called Photodynamic Therapy, requires the surgeon to use tiny, pinhead-size Light Emitting Diodes (LEDs) (a source that releases long wavelengths of light ) to activate light-sensitive, tumor-treating drugs. 'A young woman operated on in May 1999 has fully recovered with no complications and no evidence of the tumor coming back,' said Dr. Harry Whelan, a pediatric neurologist at the Medical Hospital of Wisconsin in Milwaukee. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can be used for hours at a time while still remaining cool to the touch. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The LEDs, developed and managed by NASA's Marshall Space Flight Center, have been used on seven Space Shuttle flights inside the Microgravity Astroculture Facility. This technology has also been successfully used to further commercial research in crop growth.

  10. Side-illuminating LED luminaires with accurate projection in high uniformity and high optical utilization factor for large-area field illumination

    National Research Council Canada - National Science Library

    Lo, Yi-Chien; Cai, Jhih-You; Tasi, Ming-Shiou; Tasi, Zheng-Yu; Sun, Ching-Cherng

    2014-01-01

    A novel light luminaire is proposed and experimentally analyzed, which accurately projects light into a large rectangular area to achieve uniform illumination and a high optical utilization factor at the target...

  11. Brain arousal regulation as response predictor for antidepressant therapy in major depression

    Science.gov (United States)

    Schmidt, Frank M.; Sander, Christian; Dietz, Marie-Elisa; Nowak, Claudia; Schröder, Thomas; Mergl, Roland; Schönknecht, Peter; Himmerich, Hubertus; Hegerl, Ulrich

    2017-01-01

    A tonically high level of brain arousal and its hyperstable regulation is supposed to be a pathogenic factor in major depression. Preclinical studies indicate that most antidepressants may counteract this dysregulation. Therefore, it was hypothesized that responders to antidepressants show a) a high level of EEG-vigilance (an indicator of brain arousal) and b) a more stable EEG-vigilance regulation than non-responders. In 65 unmedicated depressed patients 15-min resting-state EEGs were recorded off medication (baseline). In 57 patients an additional EEG was recorded 14 ± 1 days following onset of antidepressant treatment (T1). Response was defined as a ≥50% HAMD-17-improvement after 28 ± 1 days of treatment (T2), resulting in 29 responders and 36 non-responders. Brain arousal was assessed using the Vigilance Algorithm Leipzig (VIGALL 2.1). At baseline responders and non-responders differed in distribution of overall EEG-vigilance stages (F2,133 = 4.780, p = 0.009), with responders showing significantly more high vigilance stage A and less low vigilance stage B. The 15-minutes Time-course of EEG-vigilance did not differ significantly between groups. Exploratory analyses revealed that responders showed a stronger decline in EEG-vigilance levels from baseline to T1 than non-responders (F2,130 = 4.978, p = 0.005). Higher brain arousal level in responders to antidepressants supports the concept that dysregulation of brain arousal is a possible predictor of treatment response in affective disorders. PMID:28345662

  12. Melatonin production accompanies arousal from daily torpor in Siberian hamsters.

    Science.gov (United States)

    Larkin, Jennie E; Yellon, Steven M; Zucker, Irving

    2003-01-01

    Arousal from deep hibernation is accompanied by a transient rise of melatonin (Mel) in circulation; there are no comparable analyses of Mel concentrations in species that undergo much shallower, shorter duration episodes of daily torpor. Serum Mel concentrations were determined during arousal from both natural daily torpor and torpor induced by 2-deoxy-D-glucose (2-DG) treatment (2,500 mg/kg, intraperitoneal [IP]); blood samples were drawn from the retro-orbital sinus of anesthetized Siberian hamsters. For animals kept in darkness during torpor, Mel concentrations were highest during early arousal when thermogenesis is maximal, and they decreased as body temperature increased during arousal and returned to baseline once euthermia was reestablished. In hamsters kept in the light during the torpor bout, Mel concentrations were elevated above basal values during arousal, but the response was significantly blunted in comparison with values recorded in darkness. Increased Mel concentrations were detected in hamsters only during arousal from torpor (either natural or 2-DG induced) and were not simply a result of the drug treatment; hamsters that remained euthermic or manifested mild hypothermia after drug treatment maintained basal Mel concentrations. We propose that increased Mel production may reflect enhanced sympathetic activation associated with intense thermogenesis during arousal from torpor rather than an adjustment of the circadian rhythm of Mel secretion.

  13. Sexual arousal and masculinity-femininity of women.

    Science.gov (United States)

    Rieger, Gerulf; Savin-Williams, Ritch C; Chivers, Meredith L; Bailey, J Michael

    2016-08-01

    Studies with volunteers in sexual arousal experiments suggest that women are, on average, physiologically sexually aroused to both male and female sexual stimuli. Lesbians are the exception because they tend to be more aroused to their preferred sex than the other sex, a pattern typically seen in men. A separate research line suggests that lesbians are, on average, more masculine than straight women in their nonsexual behaviors and characteristics. Hence, a common influence could affect the expression of male-typical sexual and nonsexual traits in some women. By integrating these research programs, we tested the hypothesis that male-typical sexual arousal of lesbians relates to their nonsexual masculinity. Moreover, the most masculine-behaving lesbians, in particular, could show the most male-typical sexual responses. Across combined data, Study 1 examined these patterns in women's genital arousal and self-reports of masculine and feminine behaviors. Study 2 examined these patterns with another measure of sexual arousal, pupil dilation to sexual stimuli, and with observer-rated masculinity-femininity in addition to self-reported masculinity-femininity. Although both studies confirmed that lesbians were more male-typical in their sexual arousal and nonsexual characteristics, on average, there were no indications that these 2 patterns were in any way connected. Thus, women's sexual responses and nonsexual traits might be masculinized by independent factors. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. Semiconducting polymer LEDs

    Directory of Open Access Journals (Sweden)

    David Braun

    2002-06-01

    The field of semiconducting polymers has its root in the 1977 discovery of the semiconducting properties of polyacetylene1. This breakthrough earned Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa the 2000 Nobel Prize in Chemistry for ‘the discovery and development of conductive polymers’2–5. Other review articles capture how more than two decades of developments in the physical and chemical understanding of these novel materials has led to new device applications as active and passive electronic and optoelectronic devices ranging from diodes and transistors to polymer LEDs, photodiodes, lasers, and solar cells6–11. Much interest in plastic devices derives from the opportunities to use clever control of polymer structure combined with relatively economical polymer synthesis and processing techniques to obtain simultaneous control over electronic, optical, chemical, and mechanical features5. This article focuses on the advances leading to polymer LEDs12–14.

  15. [LED lights in dermatology].

    Science.gov (United States)

    Noé, C; Pelletier-Aouizerate, M; Cartier, H

    2017-01-16

    The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology.

  16. High-Efficiency Robust Free-Standing Composited Phosphor Films with 2D and 3D Nanostructures for High-Power Remote White LEDs.

    Science.gov (United States)

    Lai, Chun-Feng; Li, Jia-Sian; Shen, Chung-Wen

    2017-02-08

    This study demonstrated that combined free-standing quasi-amorphous/micropattern (QA/MP) composited resin film-assisted phosphor films enhanced the mechanical robustness, luminous efficacy, color rendering index (CRI), and special R9 of high-power remote warm white light-emitting diodes (WLEDs). Introducing QA/MP nanostructures into phosphor film resulted in high efficiency of remote warm WLEDs with low phosphor thickness (approximately 25 μm) and reduced the correlated color temperature (CCT) from cold white light (approximately 5565 K) to warm white light (approximately 3178 K). The QA/MP composited phosphor films (CPFs) used for high-power remote WLEDs enhanced the CRI and special R9 and reduced the CCT. These results were attributed to that QA resin film reflected the blue light and re-emitted the added red emission. CIR (84), a natural warm white CCT (3178 K), and an acceptable luminous efficacy (102.5 lm/W) were achieved from the QA/MP CPFs of high-power remote WLEDs during operation at an input power of 10 W (current of 700 mA). The bending strength of QA/MP CPFs at approximately 112 N was significantly enhanced by 40% compared with that of flat CPFs. The QA/MP CPFs applied to high-power remote WLEDs exhibited good thermal and optical stability. QA/MP CPFs were also conducted to a reliability analysis (RA), in which temperature of 85 °C and relative humidity of 85% were applied for 3288 h. Lumen maintenance was degraded by 8% during RA test because the transmittance of trimethylolopropane ethoxylate triacrylate resins was degraded under high temperature. Overall, we implemented a reliable and inexpensive technology that can potentially reduce phosphor thickness, address the out-bin problems of defective WLEDs, and fabricate flat-panel lighting source with good lighting quality.

  17. Parents’ empathic perspective taking and altruistic behavior predicts infants’ arousal to others’ emotions

    Science.gov (United States)

    Upshaw, Michaela B.; Kaiser, Cheryl R.; Sommerville, Jessica A.

    2015-01-01

    Empathy emerges in children’s overt behavior around the middle of the second year of life. Younger infants, however, exhibit arousal in response to others’ emotional displays, which is considered to be a precursor to fully developed empathy. The goal of the present study was to investigate individual variability in infants’ arousal toward others’ emotional displays, as indexed by 12- and 15-month-old infants’ (n = 49) pupillary changes in response to another infant’s emotions, and to determine whether such variability is linked to parental empathy and prosociality, as indexed via self-report questionnaires. We found that increases in infants’ pupil dilation in response to others’ emotional displays were associated with aspects of parental empathy and prosociality. Specifically, infants who exhibited the greatest arousal in response to others’ emotions had parents who scored highly on empathic perspective taking and self-reported altruism. These relations may have been found because arousal toward others’ emotions shares certain characteristics with empathic and prosocial dispositions. Together, these results demonstrate the presence of early variability in a precursor to mature empathic responding in infancy, which is meaningfully linked to parents’ empathic dispositions and prosocial behaviors. PMID:25883577

  18. Parents' empathic perspective taking and altruistic behavior predicts infants' arousal to others' emotions.

    Science.gov (United States)

    Upshaw, Michaela B; Kaiser, Cheryl R; Sommerville, Jessica A

    2015-01-01

    Empathy emerges in children's overt behavior around the middle of the second year of life. Younger infants, however, exhibit arousal in response to others' emotional displays, which is considered to be a precursor to fully developed empathy. The goal of the present study was to investigate individual variability in infants' arousal toward others' emotional displays, as indexed by 12- and 15-month-old infants' (n = 49) pupillary changes in response to another infant's emotions, and to determine whether such variability is linked to parental empathy and prosociality, as indexed via self-report questionnaires. We found that increases in infants' pupil dilation in response to others' emotional displays were associated with aspects of parental empathy and prosociality. Specifically, infants who exhibited the greatest arousal in response to others' emotions had parents who scored highly on empathic perspective taking and self-reported altruism. These relations may have been found because arousal toward others' emotions shares certain characteristics with empathic and prosocial dispositions. Together, these results demonstrate the presence of early variability in a precursor to mature empathic responding in infancy, which is meaningfully linked to parents' empathic dispositions and prosocial behaviors.

  19. Heterogeneity in Autonomic Arousal Level in Perseverative Worry: The Role of Cognitive Control and Verbal Thought

    Science.gov (United States)

    Toh, Gim Y.; Vasey, Michael W.

    2017-01-01

    One puzzle in high worry and generalized anxiety disorder (GAD) is the heterogeneity in the level of autonomic arousal symptoms seen among affected individuals. While current models agree that worry persists, in part, because it fosters avoidance of unpleasant internal experiences, they disagree as to whether worry does so by suppressing activation of autonomic arousal or by fostering persistent autonomic hyperarousal. Our Cognitive Control Model predicts that which pattern of autonomic arousal occurs depends on whether or not a worrier has sufficient cognitive control capacity to worry primarily in a verbal versus imagery-based manner. Because this model has been supported by only one study to date, the present study sought to replicate and extend that study’s findings. Results from an online survey in an unselected sample of over 900 college students provide further support for our model’s central tenet and initial support for its prediction that higher effortful control is associated with a higher percentage of verbal thought during worry. Finally, we report tentative evidence that autonomic arousal symptoms in worry and GAD vary as a function of individual differences in cognitive control capacity because higher capacity is linked to a greater predominance of verbal thought during worry.

  20. Parents’ Empathic Perspective Taking and Altruistic Behavior predicts Infants’ Arousal to Others’ Emotions

    Directory of Open Access Journals (Sweden)

    Michaela Boone Upshaw

    2015-04-01

    Full Text Available Empathy emerges in children’s overt behavior around the middle of the second year of life. Younger infants, however, exhibit arousal in response to others’ emotional displays, which is considered to be a precursor to fully developed empathy. The goal of the present study was to investigate individual variability in infants’ arousal towards others’ emotional displays, as indexed by 12- and 15-month-old infants’ (n = 49 pupillary changes in response to another infant’s emotions, and to determine whether such variability is linked to parental empathy and prosociality, as indexed via self-report questionnaires. We found that increases in infants’ pupil dilation in response to others’ emotional displays were associated with aspects of parental empathy and prosociality. Specifically, infants who exhibited the greatest arousal in response to others’ emotions had parents who scored highly on empathic perspective taking and self-reported altruism. These relations may have been found because arousal towards others’ emotions shares certain characteristics with empathic and prosocial dispositions. Together, these results demonstrate the presence of early variability in a precursor to mature empathic responding in infancy, which is meaningfully linked to parents’ empathic dispositions and prosocial behaviors.

  1. Caffeine and theanine exert opposite effects on attention under emotional arousal.

    Science.gov (United States)

    Giles, Grace E; Mahoney, Caroline R; Brunyé, Tad T; Taylor, Holly A; Kanarek, Robin B

    2017-01-01

    Tea is perceived as more relaxing than coffee, even though both contain caffeine. L-theanine in tea may account for the difference. Consumed together, caffeine and theanine exert similar cognitive effects to that of caffeine alone, but exert opposite effects on arousal, in that caffeine accentuates and theanine mitigates physiological and felt stress responses. We evaluated whether caffeine and theanine influenced cognition under emotional arousal. Using a double-blind, repeated-measures design, 36 participants received 4 treatments (200 mg caffeine + 0 mg theanine, 0 mg caffeine + 200 mg theanine, 200 mg caffeine + 200 mg theanine, 0 mg caffeine + 0 mg theanine) on separate days. Emotional arousal was induced by highly arousing negative film clips and pictures. Mood, salivary cortisol, and visual attention were evaluated. Caffeine accentuated global processing of visual attention on the hierarchical shape task (p Caffeine reduced flanker conflict difference scores on the Attention Network Test (p caffeine and theanine exert opposite effects on certain attentional processes, but when consumed together, they counteract the effects of each other.

  2. Images From a Jointly-Arousing Collective Ritual Reveal Affective Polarization

    Directory of Open Access Journals (Sweden)

    Joseph A. Bulbulia

    2013-12-01

    Full Text Available Collective rituals are biologically ancient and culturally pervasive, yet few studies have quantified effects on participants. We assessed two plausible models from qualitative anthropology: ritual empathy predicts affective convergence among all ritual participants irrespective of ritual role; rite-of-passage predicts emotional differences, specifically that ritual initiates will express relatively negatively valence when compared with non-initiates. To evaluate model predictions, images of participants in a Spanish fire-walking ritual were extracted from video data and assessed by nine Spanish raters for arousal and valence. Consistent with rite-of-passage, we found that arousal jointly increased for all participants but that valence differed by ritual role: fire-walkers exhibited increasingly positive arousal and increasingly negative valence when compared with passengers. This result offers the first quantified evidence for rite of passage dynamics within a highly arousing collective ritual. Methodologically, we show that surprisingly simple and non-invasive data structures (rated video images may be combined with methods from evolutionary ecology (Bayesian Generalized Linear Mixed Effects models to clarify poorly understood dimensions of the human condition.

  3. Images from a jointly-arousing collective ritual reveal affective polarization.

    Science.gov (United States)

    Bulbulia, Joseph A; Xygalatas, Dimitris; Schjoedt, Uffe; Fondevila, Sabela; Sibley, Chris G; Konvalinka, Ivana

    2013-01-01

    Collective rituals are biologically ancient and culturally pervasive, yet few studies have quantified their effects on participants. We assessed two plausible models from qualitative anthropology: ritual empathy predicts affective convergence among all ritual participants irrespective of ritual role; rite-of-passage predicts emotional differences, specifically that ritual initiates will express relatively negative valence when compared with non-initiates. To evaluate model predictions, images of participants in a Spanish fire-walking ritual were extracted from video footage and assessed by nine Spanish raters for arousal and valence. Consistent with rite-of-passage predictions, we found that arousal jointly increased for all participants but that valence differed by ritual role: fire-walkers exhibited increasingly positive arousal and increasingly negative valence when compared with passengers. This result offers the first quantified evidence for rite of passage dynamics within a highly arousing collective ritual. Methodologically, we show that surprisingly simple and non-invasive data structures (rated video images) may be combined with methods from evolutionary ecology (Bayesian Generalized Linear Mixed Effects models) to clarify poorly understood dimensions of the human condition.

  4. Regulation of zebrafish sleep and arousal states: current and prospective approaches

    Directory of Open Access Journals (Sweden)

    Cindy N Chiu

    2013-04-01

    Full Text Available Every day, we shift among various states of sleep and arousal to meet the many demands of our bodies and environment. A central puzzle in neurobiology is how the brain controls these behavioral states, which are essential to an animal’s well-being and survival. Mammalian models have predominated sleep and arousal research, although in the past decade, invertebrate models have made significant contributions to our understanding of the genetic underpinnings of behavioral states. More recently, the zebrafish has emerged as a promising model system for sleep and arousal research. Here we review experimental evidence that the zebrafish, a diurnal vertebrate, exhibits fundamental behavioral and neurochemical characteristics of mammalian sleep and arousal. We also propose how specific advantages of the zebrafish can be harnessed to advance the field. These include tractable genetics to identify and manipulate molecular and cellular regulators of behavioral states, optical transparency to facilitate in vivo observation of neural structure and function, and amenability to high-throughput drug screens to discover novel therapies for neurological disorders.

  5. Effects of different light wavelengths from LEDs on oxidative stress and apoptosis in olive flounder (Paralichthys olivaceus) at high water temperatures.

    Science.gov (United States)

    Kim, Bong-Seok; Jung, Seo Jin; Choi, Young Jae; Kim, Na Na; Choi, Cheol Young; Kim, Jae-Woo

    2016-08-01

    We investigated how different light spectra affect thermal stress in olive flounder (Paralichthys olivaceus), using light emitting diodes (LEDs; blue, 450 nm; green, 530 nm; red, 630 nm) at two intensities (0.3 and 0.5 W/m(2)) at relatively high water temperatures (25 and 30 °C, compared to a control condition of 20 °C). We measured the expression and activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT), and the levels of plasma hydrogen peroxide (H2O2) and lipid peroxidation (LPO). Furthermore, the levels and mRNA expression of caspase-3 were measured, and terminal transferase dUTP nick end labeling (TUNEL) assays of liver and comet assays were performed. The expression and activity of antioxidant enzymes, as well as plasma H2O2 and LPO levels were significantly higher after exposure to high temperatures, and significantly lower after exposure to green and blue light. Caspase-3 levels and mRNA expression showed a similar pattern. The TUNEL assay showed that apoptosis markedly increased at higher water temperatures, compared with the 20 °C control. In contrast, green light irradiation decreased apoptosis rate. Furthermore, the comet assays showed that nuclear DNA damage was caused by thermal stress, and that green light irradiation played a role in partially preventing this damage. Overall, these results suggest that light with green and blue wavelengths can reduce both high temperature-induced oxidative stress and apoptosis, and that particularly green light is efficient for this. Therefore, green light can play a role in protecting in olive flounder from thermal stress damage.

  6. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific ex

  7. Spectroradiometry for LED characterization

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten

    Radiospectroscopy is the absolute measurement of electromagnetic radiation within a specific wavelength range. For characterization of LED components, light sources and lamps we are interested in absolute measurement of the spectral power distribution, SPD, in the visible and near infrared region...

  8. Generation of solar spectrum by using LEDs

    Science.gov (United States)

    Lu, Pengzhi; Yang, Hua; Pei, Yanrong; Li, Jing; Xue, Bin; Wang, Junxi; Li, Jinmin

    2016-09-01

    Light emitting diode (LED) has been recognized as an applicable light source for indoor and outdoor lighting, city beautifying, landscape facilities, and municipal engineering etc. Conventional LED has superior characteristics such as long life time, low power consumption, high contrast, and wide viewing angle. Recently, LED with high color-rendering index and special spectral characteristics has received more and more attention. This paper is intended to report a solar spectrum simulated by multichip LED light source. The typical solar spectrum of 5500k released by CIE was simulated as a reference. Four types of LEDs with different spectral power distributions would be used in the LED light source, which included a 430nm LED, a 480nm LED, a 500nm LED and a white LED. In order to obtain better simulation results, the white LED was achieved by a 450nm LED chip with the mixture of phosphor. The phosphor combination was prepared by mixing green phosphor, yellow phosphor and red phosphor in a certain proportion. The multichip LED light source could provide a high fidelity spectral match with the typical solar spectrum of 5500k by adjusting injection current to each device. The luminous flux, CIE chromaticity coordinate x, y, CCT, and Ra were 104.7 lm, 0.3337, 0.3681, 5460K, and 88.6, respectively. Because of high color-rendering index and highly match to the solar spectrum, the multichip LED light source is a competitive candidate for applications where special spectral is required, such as colorimetric measurements, visual inspection, gemstone identification and agriculture.

  9. a New Red Phosphor of the Mn Activated Non-Stoichiometric Strontium Aluminate 3SrO•5Al2O3 for High Color Rendering White Leds

    Science.gov (United States)

    Chen, Lei; Zhang, Yao; Liu, Fayong; Deng, Xiaorong; Xue, Shaochan; Luo, Anqi; Jiang, Yang; Chen, Shifu; Zhang, Wenhua

    2013-05-01

    A new red phosphor of strontium aluminate activated by Mn4+ was developed for high color rendering and warm white light-emitting diodes. The phosphor composition and conditions for synthesis were optimized through solid-state reaction. Meanwhile, the structure and morphology were investigated with XRD and SEM analysis. The results show that the 3SrO•5Al2O3 activated by 0.0005 M Mn fired at 1300°C in air ambient by adopting 2.5 wt.% AlF3 as flux exhibits most efficient luminescence. A white LED device prototype with CIE (0.3291, 0.3571), CCT 5639 K, CRI Ra 92.6, and efficacy 63 lm/W driven at 20 mA has been packaged by pre-coating the red phosphor combined with a yellow one Y3Al5O12:Ce3+ on a blue InGaN chip. The analysis of critical distance and luminescence quench reveal that the mechanism of energy transfer for luminescence is through dipole-dipole interaction.

  10. Visible light communication based on high-power white light LED%基于大功率白光LED的可见光通信

    Institute of Scientific and Technical Information of China (English)

    宋其岩; 赵阳; 刘福有; 杨婧

    2015-01-01

    The visible light communication system is based on STM32 high⁃power white light LED,whose transmission dis⁃tance from transmitting to receiving of white light can reach as far as 5 m. The system can transmit 300 Hz~8 kHz analog signal and high fidelity audio⁃frequency. Its baud rate is up to 1.6 Mb/s. The output signal has no obvious distortion on oscilloscope. Analog signal takes octuple sampling,and audio⁃frequency signal takes sextuple sampling. The signal was sampled by 12⁃bit A/D converter after pulling up and amplifying,and emitted by the principal station through white light LED after △ compression. The signal is received by the receiving station through photoelectric receiving tube,and then converted into analog signal by decoding and D/A converting. The analog signal is output to oscilloscope or audio frequency amplifier after filtering and amplifying.%该设计是基于STM32的大功率白光LED可见光通信系统,白光从发送到接收传输距离最高可达5 m。可传输频率为300 Hz~8 kHz的模拟信号及高保真音频,波特率可达1.6 Mb/s,输出信号在示波器上无明显失真。该系统具备双信道通信,两路信道同时均可传输300 Hz~8 kHz的模拟信号。由从站LCD12864液晶显示当前单信道通信或双信道通信。模拟信号经传输后在示波器上显示无明显失真。模拟信号为8倍采样,音频为6倍采样,采样信号经上拉放大后由12位A/D转换器采样,经过△压缩后由主站通过白光LED发射。接收站通过光电接收管接收信号后经解码、D/A转换,转换为模拟信号,模拟信号经滤波放大后输出至示波器或音频放大器。

  11. Effect of profile and size of isolation trench on the optical and electrical performance of GaN-based high-voltage LEDs

    Science.gov (United States)

    Zhou, Shengjun; Zheng, Chenju; Lv, Jiajiang; Liu, Yingce; Yuan, Shu; Liu, Sheng; Ding, Han

    2016-03-01

    Four types of HV-LEDs with different isolation trench width were presented. The isolation trench with an oblique angle of 45.6° was obtained using a combination of Cl2/BCl3 plasma chemistry and a thermally reflowed photoresist mask layer, enabling conformal metal lines coverage across the isolation trench. The effect of isolation trench width on the optical and electrical characteristics of HV LEDs was also investigated. A quantitative model was developed to analyze light coupling propagation phenomenon occurring within HV LEDs. The suppression of light coupling propagation among adjacent LED cells was achieved by extending isolation trench width from 3.81 μm to 12.30 μm, which improved light extraction efficiency and thus increased light output power of HV LEDs. However, the significantly increasing loss of MQW active region area, which was caused by further extending isolation trench width from 12.30 μm to 40.49 μm, decreased light output power of HV LEDs.

  12. Hybrid 2D photonic crystal-assisted Lu3Al5O12:Ce ceramic-plate phosphor and free-standing red film phosphor for white LEDs with high color-rendering index.

    Science.gov (United States)

    Park, Hoo Keun; Oh, Ji Hye; Kang, Heejoon; Zhang, Jian; Do, Young Rag

    2015-03-04

    This paper reports the combined optical effects of a two-dimensional (2D) SiNx photonic crystal layer (PCL)-assisted Lu3Al5O12:Ce (LuAG:Ce) green ceramic-plate phosphor (CPP) and a free-standing (Sr,Ca)AlSiN3:Eu red film phosphor to enhance luminous efficacy, color rendering index (CRI), and special CRI (R9) of LuAG:Ce CPP-capped white light-emitting diodes (LEDs) for high-power white LEDs at 350 mA. By introducing the 2D SiNx PCL, the luminous efficacy was improved by a factor of 1.25 and 1.15 compared to that of the conventional flat CPP-capped LED and the thickness-increased CPP-capped LED (with a thickness of 0.15 mm), respectively, while maintaining low color-rendering properties. The combining of the free-standing red film phosphor in the flat CPP-capped, the 2D PCL-assisted CPP-capped, and the thickness-increased CPP-capped LEDs led to enhancement of the CRI and the special CRI (R9); it also led to a decrease of the correlated color temperature (CCT) due to broad wavelength coverage via the addition of red emission. High CRI (94), natural white CCT (4450 K), and acceptable luminous efficacy (71.1 lm/W) were attained from the 2D PCL-assisted LuAG:Ce CPP/free-standing red film phosphor-based LED using a red phosphor concentration of 7.5 wt %. It is expected that the combination of the 2D PCL and the free-standing red film phosphor will be a good candidate for achieving a high-power white CPP-capped LED with excellent CRI.

  13. Leuprolide acetate suppresses pedophilic urges and arousability.

    Science.gov (United States)

    Schober, Justine M; Kuhn, Phyllis J; Kovacs, Paul G; Earle, James H; Byrne, Peter M; Fries, Ruth A

    2005-12-01

    Cognitive-behavioral psychotherapy was compared with cognitive-behavioral psychotherapy augmented by leuprolide acetate (LA) for suppression of pedophilic behavior. Five male pedophiles (M age, 50 years; range, 36-58) were administered LA by Depo injection for 12 months, followed by saline placebo for 12 months. Testosterone levels, sexual interest preference by visual reaction time (Abel Assessment), penile tumescence (Monarch Penile Plethysmography, PPG), as well as strong sexual urges toward children and masturbatory frequency involving thoughts of children (polygraph), were measured every 3 months. On LA, testosterone decreased to castrate levels. Penile tumescence was significantly suppressed compared with baseline, but sufficient response remained to detect pedophilic interest. Pedophilic interest was also detected by visual reaction times. When asked about having pedophilic urges and masturbating to thoughts of children, all subjects self-reported a decrease. Polygraph responses indicated subjects were not deceptive. On placebo, testosterone and physiologic arousal eventually rose to baseline. As noted by polygraph, at baseline and on placebo, subjects were deceptive regarding increased pedophilic urges and masturbatory frequency. Interest preference, as measured by Abel Assessment and Monarch PPG, was generally unchanged throughout the study. Cognitive-behavioral psychotherapy augmented with LA significantly reduced pedophilic fantasies, urges, and masturbation; however, pedophilic interest did not change during 1 year of therapy. Deceptive responses by polygraph suggested that self-report was unreliable. Follow-up utilizing objective measures is essential for monitoring efficacy of treatment in pedophilia. Our study supports the premise that suppression of pedophilic behavior is possible. LA may augment cognitive-behavioral psychotherapy and help break the sequence leading to a re-offense.

  14. Stereotype threat and arousal: effects on women's math performance.

    Science.gov (United States)

    O'Brien, Laurie T; Crandall, Christian S

    2003-06-01

    Theories of arousal suggest that arousal should decrease performance on difficult tasks and increase performance on easy tasks. An experiment tested the hypothesis that the effects of stereotype threat on performance are due to heightened arousal. The authors hypothesized that telling participants that a math test they are about to take is known to have gender differences would cause stereotype threat in women but not in men. In the experiment, each participant took two tests--a difficult math test and an easy math test. Compared to women in a "no differences" condition, women in the "gender differences" condition scored better on the easy math test and worse on the difficult math test. Men's performance was unaffected by the manipulation. These data are consistent with an arousal-based explanation of stereotype threat effects. Data were inconsistent with expectancy, evaluation apprehension, and persistence explanations of the stereotype threat phenomenon.

  15. Energetical bases of extraversion: effort, arousal, EEG, and performance.

    Science.gov (United States)

    Beauducel, André; Brocke, Burkhard; Leue, Anja

    2006-11-01

    This study investigates an extension of H.J. Eysenck's [Eysenck, H.J., 1967. The Biological Basis of Personality. Charles C. Thomas, Springfield, IL] arousal theory of extraversion, incorporating an effort system as a control system for different aspects of arousal. Extraverts were expected to have lower levels of reticocortical arousal than introverts, to invest more effort, and to have lower task performance in a monotonous vigilance task. In a 40-min vigilance task, participants had to react to the shorter of two 1 kHz tones presented binaurally at an event rate of 200 per 10 min. Spontaneous EEG, event-related potential, and performance data of 40 extremely introverted and 41 extremely extraverted students were available for statistical analysis. A tendency for lower arousal levels of extraverts (alpha 2 band), the expected higher effort investment (P300) and a lower performance (hits) of extraverts were found.

  16. Emotional valence and arousal affect reading in an interactive way: neuroimaging evidence for an approach-withdrawal framework.

    Science.gov (United States)

    Citron, Francesca M M; Gray, Marcus A; Critchley, Hugo D; Weekes, Brendan S; Ferstl, Evelyn C

    2014-04-01

    A growing body of literature shows that the emotional content of verbal material affects reading, wherein emotional words are given processing priority compared to neutral words. Human emotions can be conceptualised within a two-dimensional model comprised of emotional valence and arousal (intensity). These variables are at least in part distinct, but recent studies report interactive effects during implicit emotion processing and relate these to stimulus-evoked approach-withdrawal tendencies. The aim of the present study was to explore how valence and arousal interact at the neural level, during implicit emotion word processing. The emotional attributes of written word stimuli were orthogonally manipulated based on behavioural ratings from a corpus of emotion words. Stimuli were presented during an fMRI experiment while 16 participants performed a lexical decision task, which did not require explicit evaluation of a word's emotional content. Results showed greater neural activation within right insular cortex in response to stimuli evoking conflicting approach-withdrawal tendencies (i.e., positive high-arousal and negative low-arousal words) compared to stimuli evoking congruent approach vs. withdrawal tendencies (i.e., positive low-arousal and negative high-arousal words). Further, a significant cluster of activation in the left extra-striate cortex was found in response to emotional than neutral words, suggesting enhanced perceptual processing of emotionally salient stimuli. These findings support an interactive two-dimensional approach to the study of emotion word recognition and suggest that the integration of valence and arousal dimensions recruits a brain region associated with interoception, emotional awareness and sympathetic functions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. CooLED - efficient LED bulbs with custrom optics - final report

    DEFF Research Database (Denmark)

    Wolff, Jesper; Corell, Dennis Dan; Dam-Hansen, Carsten

    Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet EUDP 64012-0226, CooLED – en ny generation LED Lyskilde for det tidsløse high-end marked.......Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet EUDP 64012-0226, CooLED – en ny generation LED Lyskilde for det tidsløse high-end marked....

  18. Fos expression at the cerebellum following non-contact arousal and mating behavior in male rats

    Science.gov (United States)

    Manzo, Jorge; Miquel, Marta; Toledo, Rebeca; Mayor-Mar, Justo Abraham; Garcia, Luis I.; Aranda-Abreu, Gonzalo E.; Caba, Mario; Hernandez, Maria Elena

    2010-01-01

    The cerebellum is considered a center underlying fine movements, cognition, memory and sexual responses. The latter feature led us to correlate sexual arousal and copulation in male rats with neural activity at the cerebellar cortex. Two behavioral paradigms were used in this investigation: the stimulation of males by distant receptive females (non-contact sexual stimulation), and the execution of up to three consecutive ejaculations. The vermis area of the cerebellum was removed following behavioral experiments, cut into sagittal sections, and analyzed with Fos immunohistochemistry to determine neuronal activation. At the mid-vermis region (sections from the midline to 0.1 mm laterally), non-contact stimulation significantly increased the activity of granule neurons. The number of activated cells increased in every lobule, but lobules 1 and 6 to 9 showed the greatest increment. In sexual behavior tests, males reaching one ejaculation had a high number of activated neurons similar to those counted after non-contact stimulation. However, two or three consecutive ejaculations showed a smaller number of Fos-ir cells. In contrast to the mid-vermis region, sections farthest from the midline (0.1 to 0.9 mm laterally) revealed that only lobule 7 expressed activated neurons. These data suggest that a well-delineated group of granule neurons have a sexual biphasic response at the cerebellar vermis, and that Fos in them is under an active degradation mechanism. Thus, they participate as a neural substrate for male rat sexual responses with an activation-deactivation process corresponding with the sensory stimulation and motor performance occurring during copulation. PMID:17936859

  19. Thermal management for LED applications

    CERN Document Server

    Poppe, András

    2014-01-01

    Thermal Management for LED Applications provides state-of-the-art information on recent developments in thermal management as it relates to LEDs and LED-based systems and their applications. Coverage begins with an overview of the basics of thermal management including thermal design for LEDs, thermal characterization and testing of LEDs, and issues related to failure mechanisms and reliability and performance in harsh environments. Advances and recent developments in thermal management round out the book with discussions on advances in TIMs (thermal interface materials) for LED applications, advances in forced convection cooling of LEDs, and advances in heat sinks for LED assemblies. This book also: Presents a comprehensive overview of the basics of thermal management as it relates to LEDs and LED-based systems Discusses both design and thermal management considerations when manufacturing LEDs and LED-based systems Covers reliability and performance of LEDs in harsh environments Has a hands-on applications a...

  20. White LED visible light communication technology research

    Science.gov (United States)

    Yang, Chao

    2017-03-01

    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  1. Design of Knight LED system

    Science.gov (United States)

    Zheng, Wen; Lou, Yuna; Xiao, Zhihong

    2010-02-01

    This design introduces a used car on the design of LED decorative light strip. This LED named Knight LED. In This system we use ATMEGA8 as the Master MCU Chip. Through the microcontroller to implement the wireless remote control receiver and the LED lights of different modes of switching, different brightness control. Also we use ULN2803 as the LED driver.

  2. Thinking anxious, feeling anxious, or both? Cognitive bias moderates the relationship between anxiety disorder status and sympathetic arousal in youth.

    Science.gov (United States)

    Rozenman, Michelle; Vreeland, Allison; Piacentini, John

    2017-01-01

    Cognitive bias and physiological arousal are two putative markers that may underlie youth anxiety. However, data on relationships between cognitive bias and arousal are limited, and typically do not include behavioral measurement of these constructs in order to tap real-time processes. We aimed to examine the relationship between performance-based cognitive bias and sympathetic arousal during stress in clinically anxious and typically-developing youth. The sample included children and adolescents ages 9 to 17 (Mean age=13.18, SD=2.60) who either met diagnostic criteria for primary generalized anxiety, social phobia, or separation anxiety (N=24) or healthy controls who had no history of psychopathology (N=22). Youth completed performance-based measures of attention and interpretation bias. Electrodermal activity was assessed while youth participated in the Trier Social Stress Test for Children (TSST-C; Buske-Kirschbaum, Jobst, & Wustmans, 1997). A mixed models analysis indicated significant linear and non-linear changes in skin conductance, with similar slopes for both groups. Interpretation bias, but not attention bias, moderated the relationship between group status and sympathetic arousal during the TSST-C. Arousal trajectories did not differ for anxious and healthy control youth who exhibited high levels of threat interpretation bias. However, for youth who exhibited moderate and low levels of interpretation bias, the anxious group demonstrated greater arousal slopes than healthy control youth. Results provide initial evidence that the relationship between anxiety status and physiological arousal during stress may be moderated by level of interpretation bias for threat. These findings may implicate interpretation bias as a marker of sympathetic reactivity in youth. Implications for future research and limitations are discussed. Published by Elsevier Ltd.

  3. Stability of Self-Reported Arousal to Sexual Fantasies Involving Children in a Clinical Sample of Pedophiles and Hebephiles.

    Science.gov (United States)

    Grundmann, Dorit; Krupp, Jurian; Scherner, Gerold; Amelung, Till; Beier, Klaus M

    2016-07-01

    In forensic research, there is a controversial discussion concerning the changeability or stability of pedophilia. Seto (2012) conceptualized pedophilia as a sexual age orientation characterized by an early onset, correlations with sexual and romantic behavior, and stability over time. However, empirical data are sparse and are mostly based on samples of detected offenders. The present study examined self-reported arousal to sexual fantasies involving children in a clinical sample of pedo-/hebephiles. In Study 1, retrospective self-reports on the age of onset and duration of sexual interest in minors were examined. In Study 2, the stability and variability of self-reported arousal to sexual fantasies involving children were evaluated prospectively. Non-prosecuted self-identifying pedo-/hebephilic men seeking professional help were recruited within the Berlin Prevention Project Dunkelfeld. Between 2005 and 2013, 494 participants completed the intake assessment. Self-reported data were collected via questionnaire focusing on sexual arousal to fantasies during masturbation involving prepubescent and/or early pubescent minors. Subsequent assessments of sexual arousal were obtained for 121 of the participants. The average time between the first and last assessment was approximately 29 months. Spearman's correlation coefficients examined the between-group rank-order and Wilcoxon signed-rank tests examined the within-individual mean-level stability. The majority of subjects reported an early onset of their pedo-/hebephilic sexual arousal. The rank-order stability was medium to high. Over the investigated period, the majority of subjects showed no or only minimal decrease or increase of self-reported sexual arousal. These results suggested that sexual arousal to fantasies involving prepubescent and/or early pubescent children is stable. Furthermore, the results support the conceptualization of pedo-/hebephilia as a sexual age orientation in men.

  4. Enhancing emotional experiences to dance through music: the role of valence and arousal in the cross-modal bias

    Directory of Open Access Journals (Sweden)

    Julia F. Christensen

    2014-10-01

    Full Text Available It is well established that emotional responses to stimuli presented to one perceptive modality (e.g. visual are modulated by the concurrent presentation of affective information to another modality (e.g. auditory – an effect known as the cross-modal bias. However, the affective mechanisms mediating this effect are still not fully understood. It remains unclear what role different dimensions of stimulus valence and arousal play in mediating the effect, and to what extent cross-modal influences impact not only our perception and conscious affective experiences, but also our psychophysiological emotional response. We addressed these issues by measuring participants’ subjective emotion ratings and their Galvanic Skin Responses in a cross-modal affect perception paradigm employing videos of ballet dance movements and instrumental classical music as the stimuli. We chose these stimuli to explore the cross-modal bias in a context of stimuli (ballet dance movements that most participants would have relatively little prior experience with. Results showed (i that the cross-modal bias was more pronounced for sad than for happy movements, whereas it was equivalent when contrasting high vs. low arousal movements, and (ii that movement valence did not modulate participants’ GSR, while movement arousal did such that GSR was potentiated in the case of low arousal movements with sad music and when high arousal movements were paired with happy music. Results are discussed in the context of the cross-modal affect perception literature and with regards to implications for the art community.

  5. Enhancing emotional experiences to dance through music: the role of valence and arousal in the cross-modal bias.

    Science.gov (United States)

    Christensen, Julia F; Gaigg, Sebastian B; Gomila, Antoni; Oke, Peter; Calvo-Merino, Beatriz

    2014-01-01

    It is well established that emotional responses to stimuli presented to one perceptive modality (e.g., visual) are modulated by the concurrent presentation of affective information to another modality (e.g., auditory)-an effect known as the cross-modal bias. However, the affective mechanisms mediating this effect are still not fully understood. It remains unclear what role different dimensions of stimulus valence and arousal play in mediating the effect, and to what extent cross-modal influences impact not only our perception and conscious affective experiences, but also our psychophysiological emotional response. We addressed these issues by measuring participants' subjective emotion ratings and their Galvanic Skin Responses (GSR) in a cross-modal affect perception paradigm employing videos of ballet dance movements and instrumental classical music as the stimuli. We chose these stimuli to explore the cross-modal bias in a context of stimuli (ballet dance movements) that most participants would have relatively little prior experience with. Results showed (i) that the cross-modal bias was more pronounced for sad than for happy movements, whereas it was equivalent when contrasting high vs. low arousal movements; and (ii) that movement valence did not modulate participants' GSR, while movement arousal did, such that GSR was potentiated in the case of low arousal movements with sad music and when high arousal movements were paired with happy music. Results are discussed in the context of the affective dimension of neuroentrainment and with regards to implications for the art community.

  6. High-efficiency Technology of LED White Light Based on Phosphor Glass%基于荧光玻璃的高效LED白光技术

    Institute of Scientific and Technical Information of China (English)

    黄波; 童玉珍; 李成明; 胡西多; 何苗; 郑树文; 李述体

    2016-01-01

    in PG, all of which are at a high level. Under different wavelength excitation, x and y in the chromaticity coordinates present roughly same linear rate of change when the mass fraction of phosphor in PG increases from 6% to 15%. In addition, the temperature of PG rose relative slowly and dropped sharply when the PG sam-ple was excited by 450 nm laser, indicating a nice property of heat resistance. The experiment re-sults show that the superior optical properties and heat resistance can be obtained by PG packaged LED, and excellent white light output can be formed.

  7. The stressed eyewitness: The interaction of thematic arousal and post-event stress in memory for central and peripheral event information

    Directory of Open Access Journals (Sweden)

    Gerald eEchterhoff

    2012-08-01

    Full Text Available Both arousal during the encoding of stimuli and subsequent stress can affect memory, often by increasing memory for important or central information. We explored whether event-based (thematic arousal and post-event stress interact to selectively enhance eyewitnesses’ memory for the central aspects of an observed incident. Specifically, we argue that memory for stimuli should be enhanced when (a the stimuli are encoded under arousal (vs. non-arousal, and (b stress is experienced soon after the encoding episode.We designed an experiment that extended previous research by manipulating arousal without changing the stimulus material, distinguishing between central and peripheral event information, and using a dynamic, life-like event instead of static pictures. After watching a video depicting a burglary under high or low thematic arousal, psychosocial stress was induced or not induced by the Trier Social Stress Test. Salivary cortisol was measured at standard intervals. Consistent with our prediction, we found a significant thematic arousal x post-event stress x centrality interaction, indicating that the recognition advantage for central event items over peripheral event items was most pronounced under both high thematic arousal and post-event stress. Because stress was induced after encoding this interaction cannot be explained by possible differences at encoding, such as narrowed attention. The centrality effect of post-event stress under high thematic arousal was statistically mediated by the cortisol increase, which suggests a key role of the stress hormone. We discuss implications of our findings for psychological and neuroscientific theories of emotional memory formation.

  8. The stressed eyewitness: the interaction of thematic arousal and post-event stress in memory for central and peripheral event information.

    Science.gov (United States)

    Echterhoff, Gerald; Wolf, Oliver T

    2012-01-01

    Both arousal during the encoding of stimuli and subsequent stress can affect memory, often by increasing memory for important or central information. We explored whether event-based (thematic) arousal and post-event stress interact to selectively enhance eyewitnesses' memory for the central aspects of an observed incident. Specifically, we argue that memory for stimuli should be enhanced when (1) the stimuli are encoded under arousal (vs. non-arousal), and (2) stress is experienced soon after the encoding episode. We designed an experiment that extended previous research by manipulating arousal without changing the stimulus material, distinguishing between central and peripheral event information, and using a dynamic, life-like event instead of static pictures. After watching a video depicting a burglary under high or low thematic arousal, psychosocial stress was induced or not induced by the Trier Social Stress Test (TSST). Salivary cortisol was measured at standard intervals. Consistent with our prediction, we found a significant post-event stress × thematic arousal × centrality interaction, indicating that the recognition advantage for central event items over peripheral event items was most pronounced under both high thematic arousal and post-event stress. Because stress was induced after encoding this interaction cannot be explained by possible differences at encoding, such as narrowed attention. The centrality effect of post-event stress under high thematic arousal was statistically mediated by the cortisol increase, which suggests a key role of the stress hormone. We discuss implications of our findings for psychological and neuroscientific theories of emotional memory formation.

  9. The stressed eyewitness: the interaction of thematic arousal and post-event stress in memory for central and peripheral event information

    Science.gov (United States)

    Echterhoff, Gerald; Wolf, Oliver T.

    2012-01-01

    Both arousal during the encoding of stimuli and subsequent stress can affect memory, often by increasing memory for important or central information. We explored whether event-based (thematic) arousal and post-event stress interact to selectively enhance eyewitnesses' memory for the central aspects of an observed incident. Specifically, we argue that memory for stimuli should be enhanced when (1) the stimuli are encoded under arousal (vs. non-arousal), and (2) stress is experienced soon after the encoding episode. We designed an experiment that extended previous research by manipulating arousal without changing the stimulus material, distinguishing between central and peripheral event information, and using a dynamic, life-like event instead of static pictures. After watching a video depicting a burglary under high or low thematic arousal, psychosocial stress was induced or not induced by the Trier Social Stress Test (TSST). Salivary cortisol was measured at standard intervals. Consistent with our prediction, we found a significant post-event stress × thematic arousal × centrality interaction, indicating that the recognition advantage for central event items over peripheral event items was most pronounced under both high thematic arousal and post-event stress. Because stress was induced after encoding this interaction cannot be explained by possible differences at encoding, such as narrowed attention. The centrality effect of post-event stress under high thematic arousal was statistically mediated by the cortisol increase, which suggests a key role of the stress hormone. We discuss implications of our findings for psychological and neuroscientific theories of emotional memory formation. PMID:22936900

  10. Thermal Performance Analysis of LED with Multichips

    Institute of Scientific and Technical Information of China (English)

    HAN Yuanyuan; GUO Hong; ZHANG Ximin; YIN Fazhang; CHU Ke; FAN Yeming

    2011-01-01

    The package and system level temperature and thermal stress distributions of 10 W light emitting diode (LED) with 4 chips and 100 W LED with 100 chips were investigated using finite element analysis.The chips were arranged on a Si sheet which is soldered on the copper/diamond composite slug with very high conductivity.The experimental results show that the maximal temperature appears in the chips of both two high power LEDs packages.Compared with the 10 W LEDs package with 4 chips array,the heat issue caused by stacking and coupling of the heat in 100 W LEDs package with 100 chips array is more serious.The chip temperature in the center of the array is much higher,and it decreases with the distance between the chip and the center of LEDs increases.Great thermal stress lies between the chips and the solder,which will reduce the reliability of the package.

  11. Implementation of a Low-Cost Automated LED Photometer for Enzymatic Reaction Detection to Teach Basic Bioelectronics Technologies in Vocational High Schools

    Science.gov (United States)

    Chen, Huai-Yi; Nieh, Hwa-Ming; Yang, Ming-Feng; Chou, Yu-Kung; Chung, Jui-Hsu; Liou, Je-Wen

    2016-01-01

    This study proposes a home-assembled, low-cost blue light-emitting diode (LED) photometer that uses simple and low-cost hardware and software, costing about US $150. This 425-nm wavelength photometer is controlled by an 89C51 microcontroller chip. Glucose concentration detection experiments involving enzyme coupling reactions were carried out to…

  12. Infrared LED irradiation applied during high-intensity treadmill training improves maximal exercise tolerance in postmenopausal women: a 6-month longitudinal study.

    Science.gov (United States)

    Paolillo, Fernanda Rossi; Corazza, Adalberto Vieira; Borghi-Silva, Audrey; Parizotto, Nivaldo Antonio; Kurachi, Cristina; Bagnato, Vanderlei Salvador

    2013-02-01

    Reduced aerobic fitness is associated with an increased risk of cardiovascular diseases among the older population. The aim of this study was to investigate the effects of LED irradiation (850 nm) applied during treadmill training on the maximal exercise tolerance in postmenopausal women. At the beginning of the study, 45 postmenopausal women were assigned randomly to three groups, and 30 women completed the entire 6 months of the study. The groups were: (1) the LED group (treadmill training associated with phototherapy, n = 10), (2) the exercise group (treadmill training, n = 10), and (3) the sedentary group (neither physical training nor phototherapy, n = 10). The training was performed for 45 min twice a week for 6 months at intensities between 85% and 90% maximal heart rate (HRmax). The irradiation parameters were 39 mW/cm(2), 45 min and 108 J/cm(2). The cardiovascular parameters were measured at baseline and after 6 months. As expected, no significant differences were found in the sedentary group (p ≥ 0.05). The maximal time of tolerance (Tlim), metabolic equivalents (METs) and Bruce stage reached significantly higher values in the LED group and the exercise group (p training (delta values) for the Tlim, METs and HR at isotime were greater in the LED group than in the exercise group with a significant intergroup difference (p training can improve maximal performance and post-exercise recovery in postmenopausal women.

  13. Inconsistent Effect of Arousal on Early Auditory Perception.

    Science.gov (United States)

    Bolders, Anna C; Band, Guido P H; Stallen, Pieter Jan M

    2017-01-01

    Mood has been shown to influence cognitive performance. However, little is known about the influence of mood on sensory processing, specifically in the auditory domain. With the current study, we sought to investigate how auditory processing of neutral sounds is affected by the mood state of the listener. This was tested in two experiments by measuring masked-auditory detection thresholds before and after a standard mood-induction procedure. In the first experiment (N = 76), mood was induced by imagining a mood-appropriate event combined with listening to mood inducing music. In the second experiment (N = 80), imagining was combined with affective picture viewing to exclude any possibility of confounding the results by acoustic properties of the music. In both experiments, the thresholds were determined by means of an adaptive staircase tracking method in a two-interval forced-choice task. Masked detection thresholds were compared between participants in four different moods (calm, happy, sad, and anxious), which enabled differentiation of mood effects along the dimensions arousal and pleasure. Results of the two experiments were analyzed both in separate analyses and in a combined analysis. The first experiment showed that, while there was no impact of pleasure level on the masked threshold, lower arousal was associated with lower threshold (higher masked sensitivity). However, as indicated by an interaction effect between experiment and arousal, arousal did have a different effect on the threshold in Experiment 2. Experiment 2 showed a trend of arousal in opposite direction. These results show that the effect of arousal on auditory-masked sensitivity may depend on the modality of the mood-inducing stimuli. As clear conclusions regarding the genuineness of the arousal effect on the masked threshold cannot be drawn, suggestions for further research that could clarify this issue are provided.

  14. Stress specificities: differential effects of coping style, gender, and type of stressor on autonomic arousal, facial expression, and subjective feeling.

    Science.gov (United States)

    Wallbott, H G; Scherer, K R

    1991-07-01

    In this study several factors considered to be relevant in mediating stress arousal were experimentally manipulated. Ss selected for the coping styles anxiety denying, low anxiety, and high anxiety were confronted with both low- and high-arousal-inducing situations, using 2 different types of stressors (cognitive vs. emotional) in each case. Arousal reactions were measured in 3 response modalities: verbal report of subjective experience; nonverbal, nonvocal behavior; and physiological reactions. The results reveal complex interactions between type and degree of stress, coping style, and gender of Ss, confirming findings on vocal parameters of stress. These complex interactions are discussed with respect to the possibility that Ss' evaluation of situation characteristics may be influenced by coping styles and gender, resulting in differential reaction patterns.

  15. Towards a smart glove: arousal recognition based on textile Electrodermal Response.

    Science.gov (United States)

    Valenza, Gaetano; Lanata, Antonio; Scilingo, Enzo Pasquale; De Rossi, Danilo

    2010-01-01

    This paper investigates the possibility of using Electrodermal Response, acquired by a sensing fabric glove with embedded textile electrodes, as reliable means for emotion recognition. Here, all the essential steps for an automatic recognition system are described, from the recording of physiological data set to a feature-based multiclass classification. Data were collected from 35 healthy volunteers during arousal elicitation by means of International Affective Picture System (IAPS) pictures. Experimental results show high discrimination after twenty steps of cross validation.

  16. Memory recall in arousing situations – an emotional von Restorff effect?

    OpenAIRE

    Hasselbach Simone; Rüsseler Jascha; Wiswede Daniel; Münte Thomas F

    2006-01-01

    Abstract Background Previous research has demonstrated a relationship between memory recall and P300 amplitude in list learning tasks, but the variables mediating this P300-recall relationship are not well understood. In the present study, subjects were required to recall items from lists consisting of 12 words, which were presented in front of pictures taken from the IAPS collection. One word per list is made distinct either by font color or by a highly arousing background IAPS picture. This...

  17. Beyond mean values: Quantifying intraindividual variability in pre-sleep arousal and sleep in younger and older community-dwelling adults

    Directory of Open Access Journals (Sweden)

    Kristy D. Shoji

    2015-01-01

    Full Text Available Intraindividual variability is an often understudied aspect of health outcomes research that may provide additional, complementary information to average values. The current paper aims to further our understanding of intraindividual variability in health research by presenting the results of a daily diary study of sleep and pre-sleep arousal. Pre-sleep arousal is often implicated in poor sleep outcomes, although the arousal–sleep association is not uniform across age groups. The examination of intraindividual variability in different age groups may provide a more complete understanding of these constructs, which, in turn, can inform future research. The overall objectives of the current study are to quantify the amount of intraindividual variability in pre-sleep arousal and sleep and to examine age differences in this variability. A sample of older (n=50 and younger (n=50 adults recruited from North Central Florida and online completed 14-consecutive-day diaries assessing pre-sleep arousal and sleep outcomes. Significant age differences were found for sleep and pre-sleep arousal; older adults displayed poorer, more variable sleep for the majority of sleep outcomes, and higher levels of pre-sleep arousal than younger adults. The high amount of intraindividual variability has implications for the assessment of pre-sleep arousal and sleep across age groups.

  18. Female Sexual Arousal: Genital Anatomy and Orgasm in Intercourse

    Science.gov (United States)

    Wallen, Kim; Lloyd, Elisabeth A.

    2013-01-01

    In men and women sexual arousal culminates in orgasm, with female orgasm solely from sexual intercourse often regarded as a unique feature of human sexuality. However, orgasm from sexual intercourse occurs more reliably in men than in women likely reflecting the different types of physical stimulation men and women require for orgasm. In men, orgasms are under strong selective pressure as orgasms are coupled with ejaculation and thus contribute to male reproductive success. By contrast, women's orgasms in intercourse are highly variable and are under little selective pressure as they are not a reproductive necessity.. The proximal mechanisms producing variability in women's orgasms are little understood. In 1924 Marie Bonaparte proposed that a shorter distance between a woman's clitoris and her urethral meatus (CUMD) increased her likelihood of experiencing orgasm in intercourse. She based this on her published data which were never statistically analyzed. In 1940 Landis and colleagues published similar data suggesting the same relationship, but these data too were never fully analyzed. We analyzed raw data from these two studies and found that both demonstrate a strong inverse relationship between CUMD and orgasm during intercourse. Unresolved is whether this increased likelihood of orgasm with shorter CUMD reflects increased penile-clitoral contact during sexual intercourse or increased penile stimulation of internal aspects of the clitoris. CUMD likely reflects prenatal androgen exposure, with higher androgen levels producing larger distances. Thus these results suggest that women exposed to lower levels of prenatal androgens are more likely to experience orgasm during sexual intercourse. PMID:21195073

  19. Neural correlates of sexual arousal in homosexual and heterosexual men.

    Science.gov (United States)

    Safron, Adam; Barch, Bennett; Bailey, J Michael; Gitelman, Darren R; Parrish, Todd B; Reber, Paul J

    2007-04-01

    Men exhibit much higher levels of genital and subjective arousal to sexual stimuli containing their preferred sex than they do to stimuli containing only the nonpreferred sex. This study used event-related functional magnetic resonance imaging to investigate how this category-specific pattern would be reflected in the brains of homosexual (n = 11) and heterosexual (n = 11) men. Comparisons of activation to preferred sexual stimuli, nonpreferred sexual stimuli, and sports stimuli revealed large networks correlated with sexual arousal, spanning multiple cortical and subcortical areas. Both homosexual and heterosexual men exhibited category-specific arousal in brain activity. Within the amygdala, greater preference-related activity was observed in homosexual men, but it is unclear whether this is a cause or a consequence of their sexuality. In a subsequent analysis of regions hypothesized to support arousal, both participant groups demonstrated widespread increases in evoked activity for preferred stimuli. Aggregate data from these regions produced significant differences between stimulus types in 16 out of 22 participants. Significant activational differences matched reported sexual orientation in 15 of these 16 participants, representing an advance in psychophysiological measures of arousal.

  20. Arousal dynamics drive vocal production in marmoset monkeys.

    Science.gov (United States)

    Borjon, Jeremy I; Takahashi, Daniel Y; Cervantes, Diego C; Ghazanfar, Asif A

    2016-08-01

    Vocal production is the result of interacting cognitive and autonomic processes. Despite claims that changes in one interoceptive state (arousal) govern primate vocalizations, we know very little about how it influences their likelihood and timing. In this study we investigated the role of arousal during naturally occurring vocal production in marmoset monkeys. Throughout each session, naturally occurring contact calls are produced more quickly, and with greater probability, during higher levels of arousal, as measured by heart rate. On average, we observed a steady increase in heart rate 23 s before the production of a call. Following call production, there is a sharp and steep cardiac deceleration lasting ∼8 s. The dynamics of cardiac fluctuations around a vocalization cannot be completely predicted by the animal's respiration or movement. Moreover, the timing of vocal production was tightly correlated to the phase of a 0.1-Hz autonomic nervous system rhythm known as the Mayer wave. Finally, a compilation of the state space of arousal dynamics during vocalization illustrated that perturbations to the resting state space increase the likelihood of a call occurring. Together, these data suggest that arousal dynamics are critical for spontaneous primate vocal production, not only as a robust predictor of the likelihood of vocal onset but also as scaffolding on which behavior can unfold.

  1. The sound of arousal in music is context-dependent.

    Science.gov (United States)

    Blumstein, Daniel T; Bryant, Gregory A; Kaye, Peter

    2012-10-23

    Humans, and many non-human animals, produce and respond to harsh, unpredictable, nonlinear sounds when alarmed, possibly because these are produced when acoustic production systems (vocal cords and syrinxes) are overblown in stressful, dangerous situations. Humans can simulate nonlinearities in music and soundtracks through the use of technological manipulations. Recent work found that film soundtracks from different genres differentially contain such sounds. We designed two experiments to determine specifically how simulated nonlinearities in soundtracks influence perceptions of arousal and valence. Subjects were presented with emotionally neutral musical exemplars that had neither noise nor abrupt frequency transitions, or versions of these musical exemplars that had noise or abrupt frequency upshifts or downshifts experimentally added. In a second experiment, these acoustic exemplars were paired with benign videos. Judgements of both arousal and valence were altered by the addition of these simulated nonlinearities in the first, music-only, experiment. In the second, multi-modal, experiment, valence (but not arousal) decreased with the addition of noise or frequency downshifts. Thus, the presence of a video image suppressed the ability of simulated nonlinearities to modify arousal. This is the first study examining how nonlinear simulations in music affect emotional judgements. These results demonstrate that the perception of potentially fearful or arousing sounds is influenced by the perceptual context and that the addition of a visual modality can antagonistically suppress the response to an acoustic stimulus.

  2. Unexpected arousal modulates the influence of sensory noise on confidence

    Science.gov (United States)

    Allen, Micah; Frank, Darya; Schwarzkopf, D Samuel; Fardo, Francesca; Winston, Joel S; Hauser, Tobias U; Rees, Geraint

    2016-01-01

    Human perception is invariably accompanied by a graded feeling of confidence that guides metacognitive awareness and decision-making. It is often assumed that this arises solely from the feed-forward encoding of the strength or precision of sensory inputs. In contrast, interoceptive inference models suggest that confidence reflects a weighted integration of sensory precision and expectations about internal states, such as arousal. Here we test this hypothesis using a novel psychophysical paradigm, in which unseen disgust-cues induced unexpected, unconscious arousal just before participants discriminated motion signals of variable precision. Across measures of perceptual bias, uncertainty, and physiological arousal we found that arousing disgust cues modulated the encoding of sensory noise. Furthermore, the degree to which trial-by-trial pupil fluctuations encoded this nonlinear interaction correlated with trial level confidence. Our results suggest that unexpected arousal regulates perceptual precision, such that subjective confidence reflects the integration of both external sensory and internal, embodied states. DOI: http://dx.doi.org/10.7554/eLife.18103.001 PMID:27776633

  3. 100 LPW 800 Lm Warm White LED

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Decai [Philips Lumileds Lighting Company, San Jose, CA (United States)

    2010-10-31

    An illumination grade warm white (WW) LED, having correlated color temperature (CCT) between 2800 K and 3500K and capable of producing 800 lm output at 100 lm/W, has been developed in this program. The high power WW LED is an ideal source for use as replacement for incandescent, and Halogen reflector and general purpose lamps of similar lumen value. Over the two year period, we have made following accomplishments: developed a high power warm white LED product and made over 50% improvements in light output and efficacy. The new high power WW LED product is a die on ceramic surface mountable LED package. It has four 1x1 mm{sup 2} InGaN pump dice flip chip attached to a ceramic submount in 2x2 array, covered by warm white phosphor ceramic platelets called Lumiramica and an overmolded silicone lens encapsulating the LED array. The performance goal was achieved through breakthroughs in following key areas: (1) High efficiency pump LED development through pump LED active region design and epi growth quality improvement (funded by internal programs). (2) Increase in injection efficiency (IE) represented by reduction in forward voltage (V{sub f}) through the improvement of the silver-based p-contact and a reduction in spreading resistance. The injection efficiency was increased from 80% at the start of the program to 96% at the end of the program at 700 mA/mm{sup 2}. (3) Improvement in thermal design as represented by reduction in thermal resistance from junction to case, through improvement of the die to submount connection in the thin film flip chip (TFFC) LED and choosing the submount material of high thermal conductivity. A thermal resistance of 1.72 K/W was demonstrated for the high power LED package. (4) Improvement in extraction efficiency from the LED package through improvement of InGaN die level and package level optical extraction efficiency improvement. (5) Improvement in phosphor system efficiency by improving the lumen equivalent (LE) and phosphor package

  4. A brief history of LED photopolymerization.

    Science.gov (United States)

    Jandt, Klaus D; Mills, Robin W

    2013-06-01

    The majority of modern resin-based oral restorative biomaterials are cured via photopolymerization processes. A variety of light sources are available for this light curing of dental materials, such as composites or fissure sealants. Quartz-tungsten-halogen (QTH) light curing units (LCUs) have dominated light curing of dental materials for decades and are now almost entirely replaced by modern light emitting diode light curing units (LED LCUs). Exactly 50 years ago, visible LEDs were invented. Nevertheless, it was not before the 1990s that LEDs were seriously considered by scientists or manufactures of commercial LCUs as light sources to photopolymerize dental composites and other dental materials. The objective of this review paper is to give an overview of the scientific development and state-of-the-art of LED photopolymerization of oral biomaterials. The materials science of LED LCU devices and dental materials photopolymerized with LED LCU, as well as advantages and limits of LED photopolymerization of oral biomaterials, are discussed. This is mainly based on a review of the most frequently cited scientific papers in international peer reviewed journals. The developments of commercial LED LCUs as well as aspects of their clinical use are considered in this review. The development of LED LCUs has progressed in steps and was made possible by (i) the invention of visible light emitting diodes 50 years ago; (ii) the introduction of high brightness blue light emitting GaN LEDs in 1994; and (iii) the creation of the first blue LED LCUs for the photopolymerization of oral biomaterials. The proof of concept of LED LCUs had to be demonstrated by the satisfactory performance of resin based restorative dental materials photopolymerized by these devices, before LED photopolymerization was generally accepted. Hallmarks of LED LCUs include a unique light emission spectrum, high curing efficiency, long life, low energy consumption and compact device form factor. By

  5. Altered interoceptive awareness in anorexia nervosa: effects of meal anticipation, consumption and bodily arousal

    Science.gov (United States)

    Khalsa, Sahib S.; Craske, Michelle G.; Li, Wei; Vangala, Sitaram; Strober, Michael; Feusner, Jamie D.

    2016-01-01

    Objective Impaired interoceptive awareness (IA), the subjective perception of internal body sensations, has been proposed as a vulnerability or maintaining factor in anorexia nervosa (AN). We examined whether IA of heartbeat and breathing sensations was impaired in AN across a range of arousal levels, and whether it was influenced by meal anticipation and consumption. Method IA was assessed using randomized, double-blinded, bolus intravenous infusions of isoproterenol, a peripheral beta-adrenergic sympathetic agonist, and saline. Fifteen women with AN and 15 age-, and sex- matched healthy comparisons were evaluated before and after consumption of a 1000 Calorie meal. During each infusion participants rated their moment-to-moment intensity of heartbeat and breathing sensations with a dial. To measure IA we evaluated interoceptive detection thresholds, retrospective ratings of palpitation and dyspnea intensity, and interoceptive accuracy via correlations between subjective dial ratings and observed heart rate responses. Results Contrary to prediction the AN group was more likely to report detection of interoceptive sensations across all conditions, an effect driven by false discriminations at low arousal levels. Concordant with prediction, meal anticipation was associated with intensified interoceptive sensations, particularly dyspnea. There were no differences in interoceptive accuracy. Discussion This represents the first demonstration of interoceptive prediction errors in AN. Although IA is unimpaired at high arousal levels in AN, prediction signals are abnormal at low arousal levels, especially during meal anticipation. Altered interoceptive prediction signaling during meal anticipation could contribute to phenotypes of high anxiety in AN or alternatively, might be explained by enhanced meal associated anxiety. PMID:25712775

  6. Advances in LEDs for automotive applications

    Science.gov (United States)

    Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

    2016-03-01

    High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

  7. Physiological arousal and perception of bodily state during parachute jumping.

    Science.gov (United States)

    Schedlowski, M; Tewes, U

    1992-01-01

    Heart rate and respiration rate were recorded with a portable data recording system before and during a parachute jump in 36 male sport parachutists with differing degrees of experience. The recordings were analyzed at 12 psychologically relevant points in time along with the subjective ratings of physical arousal. Novice parachutists showed a higher degree of self-rated arousal during jumps. However, the two groups displayed nearly parallel curves for heart and respiration rates, differing significantly from each other only in the level of their respective heart rates. Furthermore, experienced jumpers seem to be better informed about their state of physiological arousal during the jump than are novice jumpers. These results do not confirm the proposed anxiety inhibition process, postulated by Epstein (1967).

  8. Cutting film violence: effects on perceptions, enjoyment, and arousal.

    Science.gov (United States)

    Berry, M; Gray, T; Donnerstein, E

    1999-10-01

    The authors investigated the effects of cutting specific graphic scenes of film violence on self-reports of arousal, enjoyability, and perceptions of violence among a sample of U.S. students. In 3 studies, they varied film exposure from 1 1/2 min in the 1st study to a complete motion picture (American vs. British version of same film) in the 3rd. In all 3 studies, the participants rated the cut versions as less violent than the uncut versions. The participants distinguished quite subtle differences in levels of violence, even when the cuts were minor and contextualized within an entire movie. Cutting the movie significantly increased its enjoyability for the women; for the men, there was no significant difference. Cutting violent films made no difference in arousal for the men but substantially lowered self-report levels of arousal for the women.

  9. Bi-directional associations between psychological arousal, cortisol, and sleep

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Albertsen, Karen; Persson, Roger

    2012-01-01

    The aim was to elucidate the possible bi-directional relation between daytime psychological arousal, cortisol, and self-reported sleep in a group of healthy employees in active employment. Logbook ratings of sleep (Karolinska Sleep Questionnaire), stress, and energy, as well as positive and negat......The aim was to elucidate the possible bi-directional relation between daytime psychological arousal, cortisol, and self-reported sleep in a group of healthy employees in active employment. Logbook ratings of sleep (Karolinska Sleep Questionnaire), stress, and energy, as well as positive...... and problems during the day. The results underpin the possibility that arousal and poor sleep might create a self-reinforcing vicious circle that negatively affects a person's well-being....

  10. Sexual arousal and rhythmic synchronization: A possible effect of vasopressin

    DEFF Research Database (Denmark)

    Miani, Alessandro

    2016-01-01

    Music is ubiquitous. Yet, its biological relevance is still an ongoing debate. Supporting the view that music had an ancestral role in courtship displays, a pilot study presented here provides preliminary evidence on the link between music and sexual selection. The underlying hypothesis is based...... on the fact that the sexually dimorphic neuropeptide vasopressin has its receptors in the part of the brain involved in music and dance performance (the basal ganglia), and its concentrations rise during sexual arousal in men. In addition, music, dance, and courtship phenotypes seem to be in part regulated...... by vasopressin and its genes. Hence, to test this hypothesis, a rhythmic synchronization task was employed here on one male subject during sexual arousal. Results revealed a significant effect of sexual arousal on rhythm synchronization. This is the first report that empirically supports the hypothesis...

  11. Atypical presentation of NREM arousal parasomnia with repetitive episodes.

    Science.gov (United States)

    Trajanovic, N N; Shapiro, C M; Ong, A

    2007-08-01

    The case report describes a distinct variant of non-REM (Rapid Eye Movement) arousal parasomnia, sleepwalking type, featuring repetitive abrupt arousals, mostly from slow-wave sleep, and various automatisms and semi-purposeful behaviours. The frequency of events and distribution throughout the night presented as a continuous status of parasomnia ('status parasomnicus'). The patient responded well to treatment typically administered for adult NREM parasomnias, and after careful review of the clinical presentation, objective findings and treatment outcome, sleep-related epilepsy was ruled out in favour of parasomnia.

  12. 照明用大功率LED射灯散热建模研究%Heat Dissipation Modeling Research of High Power LED Spot Lamp for Lighting

    Institute of Scientific and Technical Information of China (English)

    陈杰; 陈忠; 李小红; 沈亚锋; 熊敬康; 王阳夏

    2013-01-01

    Heat dissipation is one of the key problems need to be solved for LED lamps as a new generation of lighting light. A heat dissipation modeling method was presented for the LED lamp. The LED spot lamp was selected for dissipative research, 3D models were established by modeling softwares, then the models were transferred into finite element thermal analysis software (CFD) for simulation. Several key aspects such as thermal resistance setting, heat load calculation and boundary conditions were considered in the analysis process, and the simulation result was compared with laboratory test data. The results show that the method can be used for accurate thermal analysis simulation of indoor LED lighting, with the temperature error less than 4 ℃, and the simulation result is of a great reference value for lighting design.%散热问题是LED灯具成为新一代照明光源亟待解决的关键问题之一.提出一种LED灯具散热建模方法:选用LED射灯作为代表产品进行散热建模研究,采用三维造型软件建立LED灯具产品三维模型,然后导入有限元流体热分析软件(CFD)进行热仿真.研究散热仿真过程中的热阻设置、热量载荷计算和边界条件设定等关键问题,并求解LED射灯的工作温度分布情况;将仿真分析结果与实验室测试数据进行对比分析研究.研究结果表明,运用该方法可以对室内照明LED灯具进行较为准确的散热分析,仿真温度误差在4℃左右,仿真结果对灯具开发设计具有重要参考价值.

  13. High-performance InGaN/GaN MQW LEDs with Al-doped ZnO transparent conductive layers grown by MOCVD using H2O as an oxidizer

    Science.gov (United States)

    Lin, Jia-Yong; Pei, Yan-Li; Zhuo, Yi; Chen, Zi-Min; Hu, Rui-Qin; Cai, Guang-Shuo; Wang, Gang

    2016-11-01

    In this study, the high performance of InGaN/GaN multiple quantum well light-emitting diodes (LEDs) with Al-doped ZnO (AZO) transparent conductive layers (TCLs) has been demonstrated. The AZO-TCLs were fabricated on the n+-InGaN contact layer by metal organic chemical vapor deposition (MOCVD) using H2O as an oxidizer at temperatures as low as 400 °C without any post-deposition annealing. It shows a high transparency (98%), low resistivity (510-4 Ω·cm), and an epitaxial-like excellent interface on p-GaN with an n+-InGaN contact layer. A forward voltage of 2.82 V @ 20 mA was obtained. Most importantly, the power efficiencies can be markedly improved by 53.8%@20 mA current injection and 39.6%@350 mA current injection compared with conventional LEDs with indium tin oxide TCL (LED-III), and by 28.8%@20 mA current injection and 4.92%@350 mA current injection compared with LEDs with AZO-TCL prepared by MOCVD using O2 as an oxidizer (LED-II), respectively. The results indicate that the AZO-TCL grown by MOCVD using H2O as an oxidizer is a promising TCL for a low-cost and high-efficiency GaN-based LED application. Project supported by the National Natural Science Foundation of China (Grant Nos. 61204091, 61404177, 51402366, and U1201254) and the Science and Technology Planning Project of Guangdong Province, China (Grant No. 2015B010132006).

  14. Misattribution of musical arousal increases sexual attraction towards opposite-sex faces in females

    Science.gov (United States)

    Schober, Raphaela; Gingras, Bruno; Leder, Helmut

    2017-01-01

    Several theories about the origins of music have emphasized its biological and social functions, including in courtship. Music may act as a courtship display due to its capacity to vary in complexity and emotional content. Support for music’s reproductive function comes from the recent finding that only women in the fertile phase of the reproductive cycle prefer composers of complex melodies to composers of simple ones as short-term sexual partners, which is also in line with the ovulatory shift hypothesis. However, the precise mechanisms by which music may influence sexual attraction are unknown, specifically how music may interact with visual attractiveness cues and affect perception and behaviour in both genders. Using a crossmodal priming paradigm, we examined whether listening to music influences ratings of facial attractiveness and dating desirability of opposite-sex faces. We also tested whether misattribution of arousal or pleasantness underlies these effects, and explored whether sex differences and menstrual cycle phase may be moderators. Our sample comprised 64 women in the fertile or infertile phase (no hormonal contraception use) and 32 men, carefully matched for mood, relationship status, and musical preferences. Musical primes (25 s) varied in arousal and pleasantness, and targets were photos of faces with neutral expressions (2 s). Group-wise analyses indicated that women, but not men, gave significantly higher ratings of facial attractiveness and dating desirability after having listened to music than in the silent control condition. High-arousing, complex music yielded the largest effects, suggesting that music may affect human courtship behaviour through induced arousal, which calls for further studies on the mechanisms by which music affects sexual attraction in real-life social contexts. PMID:28892486

  15. The influence of pre-sleep cognitive arousal on sleep onset processes.

    Science.gov (United States)

    Wuyts, Johan; De Valck, Elke; Vandekerckhove, Marie; Pattyn, Nathalie; Bulckaert, Arnoud; Berckmans, Daniel; Haex, Bart; Verbraecken, Johan; Cluydts, Raymond

    2012-01-01

    Cognitive hyperarousal, resulting in enhanced cognitive activation, has been cited as an important contributor to the development and preservation of insomnia. To further understand this process, our study examined the effects of acutely-induced pre-sleep cognitive hyperarousal on sleep onset processes in healthy volunteers. Following an adaptation night, 15 subjects slept two nights in our sleep laboratory: one reference night and another one with cognitive arousal induction, in a counterbalanced order. In the cognitive arousal condition, subjects worked through half an hour of cognitive tasks without interference of an emotional component prior to retiring to bed. Objective sleep onset latency was significantly prolonged in the cognitive arousal condition compared to the reference condition. Significantly more high frequency activity was recorded during the first and second deep-sleep period. Moreover, differences in heart rate and proximal temperature during and after sleep onset were observed in the nights after the cognitive induction. Pre-sleep cognitive activation successfully induced a significant cognitive load and activation in our subjects to influence subsequent sleep (onset) processes.

  16. Accelerative and decelerative effects of hedonic valence and emotional arousal during visual scene processing.

    Science.gov (United States)

    Ihssen, Niklas; Keil, Andreas

    2013-01-01

    Perceptual processing of natural scene pictures is enhanced when the scene conveys emotional content. Such "motivated attention" to pleasant and unpleasant pictures has been shown to improve identification accuracy in non-speeded behavioural tasks. An open question is whether emotional content also modulates the speed of visual scene processing. In the present studies we show that unpleasant content reliably slowed two-choice categorization of pictures, irrespective of physical image properties, perceptual complexity, and categorization instructions. Conversely, pleasant content did not slow or even accelerated choice reactions, relative to neutral scenes. As indicated by lateralized readiness potentials, these effects occurred at cognitive processing rather than motor preparation/execution stages. Specifically, analysis of event-related potentials showed a prolongation of early scene discrimination for stimuli perceived as emotionally arousing, regardless of valence, and reflected in delayed peaks of the N1 component. In contrast, the timing of other processing steps, reflected in the P2 and late positive potential components and presumably related to post-discriminatory processes such as stimulus-response mapping, appeared to be determined by hedonic valence, with more pleasant scenes eliciting faster processing. Consistent with this model, varying arousal (low/high) within the emotional categories mediated the effects of valence on choice reaction speed. Functionally, arousal may prolong stimulus analysis in order to prevent erroneous and potentially harmful decisions. Pleasantness may act as a safety signal allowing rapid initiation of overt responses.

  17. Being watched by others eliminates the effect of emotional arousal on inhibitory control

    Directory of Open Access Journals (Sweden)

    Jiaxin eYu

    2015-01-01

    Full Text Available The psychological effect of being watched by others has been proven a powerful tool in modulating social behaviors (e.g., charitable giving and altering cognitive performance (e.g., visual search. Here we tested whether such awareness would affect one of the core elements of human cognition: emotional processing and impulse control. Using an emotion stop-signal paradigm, we found that viewing emotionally-arousing erotic images before attempting to inhibit a motor response impaired participants’ inhibition ability, but such an impairing effect was completely eliminated when participants were led to believe that their facial expressions were monitored by a webcam. Furthermore, there was no post-error slowing in any of the conditions, thus these results cannot be explained by a deliberate speed-accuracy tradeoff or other types of conscious shift in strategy. Together, these findings demonstrate that the interaction between emotional arousal and impulse control can be dependent on one’s state of self-consciousness. Furthermore, this study also highlights the effect that the mere presence of the experimenter may have on participants’ cognitive performance, even if it’s via a webcam.

  18. Frontostriatal Circuit Dynamics Correlate with Cocaine Cue-Evoked Behavioral Arousal during Early Abstinence.

    Science.gov (United States)

    Smith, Wesley C; Rosenberg, Matthew H; Claar, Leslie D; Chang, Victoria; Shah, Sagar N; Walwyn, Wendy M; Evans, Christopher J; Masmanidis, Sotiris C

    2016-01-01

    It is thought that frontostriatal circuits play an important role in mediating conditioned behavioral responses to environmental stimuli that were previously encountered during drug administration. However, the neural correlates of conditioned responses to drug-associated cues are not well understood at the level of large populations of simultaneously recorded neurons, or at the level of local field potential (LFP) synchrony in the frontostriatal network. Here we introduce a behavioral assay of conditioned arousal to cocaine cues involving pupillometry in awake head-restrained mice. After just 24 h of drug abstinence, brief exposures to olfactory stimuli previously paired with cocaine injections led to a transient dilation of the pupil, which was greater than the dilation effect to neutral cues. In contrast, there was no cue-selective change in locomotion, as measured by the rotation of a circular treadmill. The behavioral assay was combined with simultaneous recordings from dozens of electrophysiologically identified units in the medial prefrontal cortex (mPFC) and ventral striatum (VS). We found significant relationships between cocaine cue-evoked pupil dilation and the proportion of inhibited principal cells in the mPFC and VS. Additionally, LFP coherence analysis revealed a significant correlation between pupillary response and synchrony in the 25-45 Hz frequency band. Together, these results show that pupil dilation is sensitive to drug-associated cues during acute stages of abstinence, and that individual animal differences in this behavioral arousal response can be explained by two complementary measures of frontostriatal network activity.

  19. Being watched by others eliminates the effect of emotional arousal on inhibitory control

    Science.gov (United States)

    Yu, Jiaxin; Tseng, Philip; Muggleton, Neil G.; Juan, Chi-Hung

    2015-01-01

    The psychological effect of being watched by others has been proven a powerful tool in modulating social behaviors (e.g., charitable giving) and altering cognitive performance (e.g., visual search). Here we tested whether such awareness would affect one of the core elements of human cognition: emotional processing and impulse control. Using an emotion stop-signal paradigm, we found that viewing emotionally-arousing erotic images before attempting to inhibit a motor response impaired participants’ inhibition ability, but such an impairing effect was completely eliminated when participants were led to believe that their facial expressions were monitored by a webcam. Furthermore, there was no post-error slowing in any of the conditions, thus these results cannot be explained by a deliberate speed-accuracy tradeoff or other types of conscious shift in strategy. Together, these findings demonstrate that the interaction between emotional arousal and impulse control can be dependent on one’s state of self-consciousness. Furthermore, this study also highlights the effect that the mere presence of the experimenter may have on participants’ cognitive performance, even if it’s only a webcam. PMID:25653635

  20. Acoustical expression of arousal in conflict situations in tree shrews (Tupaia belangeri).

    Science.gov (United States)

    Schehka, Simone; Esser, Karl-Heinz; Zimmermann, Elke

    2007-08-01

    Empirical research on human and non-human primates suggests that communication sounds express the intensity of an emotional state of a signaller. In the present study, we have examined communication sounds during induced social interactions of a monogamous mammal, the tree shrew. To signal their unwillingness to mate, female tree shrews show defensive threat displays towards unfamiliar males paralleled by acoustically variable squeaks. We assumed that the distance between interacting partners as well as the behavior of the male towards the female indicates the intensity of perceived social threat and thereby the arousal state of a female. To explore this hypothesis we analyzed dynamic changes in communication sounds uttered during induced social interactions between a female and an unfamiliar male. Detailed videographic and sound analyzes revealed that the arousal state predicted variations in communication sound structure reliably. Both, a decrease of distance and a male approaching the female led to an increase in fundamental frequency and repetition rate of syllables. These findings support comparable results in human and non-human primates and suggest that common coding rules in communication sounds govern acoustic conflict regulation in mammals.

  1. ZnO nanorods/graphene/Ni/Au hybrid structures as transparent conductive layer in GaN LED for low work voltage and high light extraction

    Science.gov (United States)

    Xu, Kun; Xie, Yiyang; Ma, Huali; Du, Yinxiao; Zeng, Fanguang; Ding, Pei; Gao, Zhiyuan; Xu, Chen; Sun, Jie

    2016-12-01

    In this paper, by virtue of one-dimensional ZnO nanorods and two-dimensional graphene film hybrid structures, both the enhanced current spreading and enhanced light extraction were realized at the same time. A 1 nm/1 nm Ni/Au layer was used as an interlayer between graphene and pGaN to form ohmic contact, which makes the device have a good forward conduction properties. Through the comparison of the two groups of making ZnO nanorods or not, it was found that the 30% light extraction efficiency of the device was improved by using the ZnO nanorods. By analysis key parameters of two groups such as the turn-on voltage, work voltage and reverse leakage current, it was proved that the method for preparing surface nano structure by hydrothermal method self-organization growth ZnO nanorods applied in GaN LEDs has no influence to device's electrical properties. The hybrid structure application in GaN LED, make an achievement of a good ohmic contact, no use of ITO and enhancement of light extraction at the same time, meanwhile it does not change the device structure, introduce additional process, worsen the electrical properties.

  2. 低成本三基色大功率LED驱动控制方案设计%Low-cost driver design for high-power tricolor LED

    Institute of Scientific and Technical Information of China (English)

    张修红; 刘廷章; 闫斌; 金碧瑶; 周壮丽

    2015-01-01

    针对三基色LED(Light Emitting Diode)驱动成本高、电路设计复杂的问题,设计了一款用于三基色大功率LED驱动控制方案.设计并制作电路驱动LED模型装置,通过单片机产生三路PWM (Pulse Width Modulation)波来控制MOSFET,从而分别控制三路LED,这样只需要一个DC/DC (Direct Current/Direct Current)驱动器,就能实现三路LED的调节,而且通过特定算法将上位机传送的标准Yxz值(遵循标准ZLL,ZigBee Light Link协议[1])转化为RGB (Red Green Blue)值.根据实验测得,三路LED调节反应迅速,显色效果优秀.

  3. Prediction of valence and arousal from music features

    NARCIS (Netherlands)

    Den Brinker, A.C.; Van Dinther, C.H.B.A.; Skowronek, J.

    2011-01-01

    Mood is an important attribute of music and knowledge on mood can beused as a basic ingredient in music recommender and retrieval systems. Moods are assumed to be dominantly determined by two dimensions:valence and arousal. An experiment was conducted to attain data forsong-based ratings of valence

  4. Arousal Modulation in Females with Fragile X or Turner Syndrome

    Science.gov (United States)

    Roberts, Jane; Mazzocco, Michele M. M.; Murphy, Melissa M.; Hoehn-Saric, Rudolf

    2008-01-01

    The present study was carried out to examine physiological arousal modulation (heart activity and skin conductance), across baseline and cognitive tasks, in females with fragile X or Turner syndrome and a comparison group of females with neither syndrome. Relative to the comparison group, for whom a greater increase in skin conductance was…

  5. Driving with music : Effects on arousal and performance

    NARCIS (Netherlands)

    Unal, Ayca Berfu; de Waard, Dick; Epstude, Kai; Steg, Linda

    2013-01-01

    In the current study, we aimed at exploring the influence of music on driving performance, arousal and mental effort while carrying out a monotonous car-following task in a low-complexity traffic setting. Participants (N = 47) were randomly assigned to loud and moderate volume music groups, and

  6. Age differences in liking and recall of arousing television commercials

    NARCIS (Netherlands)

    M. van der Goot; E. van Reijmersdal

    2011-01-01

    This paper examines age differences in liking of arousing television commercials and recall of the advertised brands and products. Based on the activation theory of information exposure, sensation seeking theory and the limited capacity model of mediated message processing, we expect that the effect

  7. Driving with music : Effects on arousal and performance

    NARCIS (Netherlands)

    Unal, Ayca Berfu; de Waard, Dick; Epstude, Kai; Steg, Linda

    2013-01-01

    In the current study, we aimed at exploring the influence of music on driving performance, arousal and mental effort while carrying out a monotonous car-following task in a low-complexity traffic setting. Participants (N = 47) were randomly assigned to loud and moderate volume music groups, and comp

  8. Creative People Create Values: Creativity and Positive Arousal in Negotiations

    Science.gov (United States)

    Schei, Vidar

    2013-01-01

    Most negotiations are ill-structured situations, and the ability to identify novel options is likely to be crucial for success. This study, therefore, examined how creativity impacts negotiation processes and outcomes, and how this effect is moderated by positive arousal. The negotiators' creative personality and their state of positive arousal…

  9. Cognitive Factors in Sexual Arousal: The Role of Distraction

    Science.gov (United States)

    Geer, James H.; Fuhr, Robert

    1976-01-01

    Four groups of male undergraduates were instructed to perform complex cognitive operations when randomly presented single digits of a dichotic listening paradigm. An erotic tape recording was played into the nonattended ear. Sexual arousal varied directly as a function of the complexity of the distracting cognitive operations. (Author)

  10. A Model of Anxious Arousal for Public Speaking

    Science.gov (United States)

    Finn, Amber N.; Sawyer, Chris R.; Behnke, Ralph R.

    2009-01-01

    With the goal of identifying the characteristics or traits students bring to the classroom that predispose them to panic when faced with the threat of presenting in front of an audience, this study introduced a subtype of public-speaking state anxiety--anxious arousal. Specifically, this study examined the extent to which trait anxiety and…

  11. Creative People Create Values: Creativity and Positive Arousal in Negotiations

    Science.gov (United States)

    Schei, Vidar

    2013-01-01

    Most negotiations are ill-structured situations, and the ability to identify novel options is likely to be crucial for success. This study, therefore, examined how creativity impacts negotiation processes and outcomes, and how this effect is moderated by positive arousal. The negotiators' creative personality and their state of positive arousal…

  12. Accurate colorimetric feedback for RGB LED clusters

    Science.gov (United States)

    Man, Kwong; Ashdown, Ian

    2006-08-01

    We present an empirical model of LED emission spectra that is applicable to both InGaN and AlInGaP high-flux LEDs, and which accurately predicts their relative spectral power distributions over a wide range of LED junction temperatures. We further demonstrate with laboratory measurements that changes in LED spectral power distribution with temperature can be accurately predicted with first- or second-order equations. This provides the basis for a real-time colorimetric feedback system for RGB LED clusters that can maintain the chromaticity of white light at constant intensity to within +/-0.003 Δuv over a range of 45 degrees Celsius, and to within 0.01 Δuv when dimmed over an intensity range of 10:1.

  13. The Design of the Radiator for the High-power LED Lights%大功率LED灯强化冷却散热器的创新设计

    Institute of Scientific and Technical Information of China (English)

    钟玉华; 孙国辉

    2013-01-01

    As energy saving,environmental protection,long life and other characteristics,LED get much attention from all walks of life.However,when high power LED is working,not only produce light at but also generate a lot of heat,about 80% of the energy is converted into heat energy,with the improvement of leds and power integration.LED the fever heat flux increases rapidly,its process of work heat releasing increase substantially.While the LED junction temperature (the temperature of the chip) directly affect the service life of the lamp,therefore,high power LED lamp,heat dissipation problems needed to improve urgently.This designs focus on LED lamp cooling growing phenomenon,to design a natural reflux cooling system,make the most of the heat generated in work process of LED comes out through the return system.The experiment proved that the system can achieve good cooling effect.%LED灯由于节能、环保、工作寿命长等特点而倍受社会各界的关注,然而大功率LED灯在工作过程中,除发光外同时产生大量热能,约有80%的能量转化为热能.随着LED的功率以及集成度的提高,LED灯的发热热流密度迅猛增加,其工作过程中散发热量大幅提高,而LED结温(芯片温度)的高低直接影响灯的使用寿命;因此,大功率LED灯的散热问题急需改善.本设计针对LED灯散热问题日益严重的现象而提出,设计出一种自然回流散热系统,使LED灯工作过程中产生的大部分热量通过回流系统散发出去,实验证明该散热系统能取得良好的散热效果.

  14. Low Cost Heart Rate Monitor Using Led-Led Sensor

    Directory of Open Access Journals (Sweden)

    Ahmed Mahrous Ragib

    2009-01-01

    Full Text Available A high sensitivity, low power and low cost sensor has been developed for photoplethysmography (PPG measurement. The PPG principle was applied to follow the dilatation and contraction of skin blood vessels during the cardiac cycle. A standard light emitting diodes (LEDs has been used as a light emitter and detector, and in order to reduce the space, cost and power, the classical analogue-to-digital converters (ADCs replaced by the pulse-based signal conversion techniques. A general purpose microcontroller has been used for the implementation of measurement protocol. The proposed approach leads to better spectral sensitivity, increased resolution, reduction in cost, dimensions and power consumption. The basic sensing configuration presented is capable of detecting the PPG signal from a finger or toe, and it is very simple to extract the heart rate and heart rate variability from such a signal.

  15. Influence of Fluorescent Glue Packaging Technology on the Color Rendering Index of High Power LED%大功率LED荧光胶封装工艺对其显色性能的影响

    Institute of Scientific and Technical Information of China (English)

    钟传鹏

    2011-01-01

    通过大量试验,探索了荧光粉分层封装和荧光粉混合封装的不同荧光胶封装工艺对大功率白光LED显色性能的影响。通过甄选荧光粉、硅胶以及配比,制备出显色指数(CRI)为95的高亮度、低衰减的大功率白光LED。%In this artical,a large number of experiments have been done to explore the influence of different fluorescent glue packaging technology of phosphor layered packaging and phosphor mixed packaging on high-power white LED color rendering.By selecting the phosphor,silicon and mixture ratio,high-power white LED with high brightness and low attenuation is prepared,and the color rendering index(CRI) reaches 95.

  16. Mono- and dichromatic LED illumination leads to enhanced growth and energy conversion for high-efficiency cultivation of microalgae for application in space.

    Science.gov (United States)

    Wagner, Ines; Steinweg, Christian; Posten, Clemens

    2016-08-01

    Illumination with red and blue photons is known to be efficient for cultivation of higher plants. For microalgae cultivation, illumination with specific wavelengths rather than full spectrum illumination can be an alternative where there is a lack of knowledge about achievable biomass yields. This study deals with the usage of color LED illumination to cultivate microalgae integrated into closed life support systems for outer space. The goal is to quantify biomass yields using color illumination (red, blue, green and mixtures) compared to white light. Chlamydomonas reinhardtii was cultivated in plate reactors with color compared to white illumination regarding PCE, specific pigment concentration and cell size. Highest PCE values were achieved under low PFDs with a red/blue illumination (680 nm/447 nm) at a 90 to 10% molar ratio. At higher PFDs saturation effects can be observed resulting from light absorption characteristics and the linear part of PI curve. Cell size and aggregation are also influenced by the applied light color. Red/blue color illumination is a promising option applicable for microalgae-based modules of life support systems under low to saturating light intensities and double-sided illumination. Results of higher PCE with addition of blue photons to red light indicate an influence of sensory pigments. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 大功率LED照明装置微热管散热方案分析%Mirco Heat Pipe Cooling Solution for High Power LED Illuminator

    Institute of Scientific and Technical Information of China (English)

    李勇; 李鹏芳; 曾志新

    2010-01-01

    设计了一种新型的带有百叶窗的平板式大功率发光二极管((LED)照明装置.该装置采用高导热系数的铝基板作为多颗大功率LED的散热电路板,用0.4 nmm的铝片作为散热翅片,结合沟槽式微热管构成集发光与散热一体化的输入功率为21 W的照明模组,该模组可根据照明亮度要求重构成不同功率的照明装置.对功率为144 W的照明装置进行了理论分析与实验研究.根据理论计算,每个照明模组的发热量约为18 W,每个照明模组的传热量约为47W;模拟结果表明,在环境温度为30℃,自然对流换热系数为10 W/(m2·K)时,LED芯片最高结温Ta=75℃,而实验测得Ta=75.7℃.

  18. Design of A Bicycle Head Lamp Based on Highly Efficient LED%基于大功率LED的自行车前照灯的设计

    Institute of Scientific and Technical Information of China (English)

    朱雪菘; 倪凯凯; 林泽文; 刘木清

    2016-01-01

    本文以CREE高功率冷白光LED为光源, 设计了高安全性的符合德国K-mark的StVZO 22A No.23法规的自行车前照灯. 其体积微小, 具有清晰的明暗截止线和均匀的光分布, 适合自行车照明的需求, 为骑行者提供了一个安全的行车环境, 也保障了行路人和其他人的人身安全.%In this paper , we propose and demonstrate a novel design of pcW-LED-based bicycle head lamp, which meets StVZO 22A No.23 regulations of K-mark Germany.It has small size, a clear cut-off and homogenous light distribution , making it suitable for bicycle lighting and providing a safe driving environment for cyclists and pedestrians as well .

  19. Tuning carrier lifetime in InGaN/GaN LEDs via strain compensation for high-speed visible light communication

    Science.gov (United States)

    Du, Chunhua; Huang, Xin; Jiang, Chunyan; Pu, Xiong; Zhao, Zhenfu; Jing, Liang; Hu, Weiguo; Wang, Zhong Lin

    2016-11-01

    In recent years, visible light communication (VLC) technology has attracted intensive attention due to its huge potential in superior processing ability and fast data transmission. The transmission rate relies on the modulation bandwidth, which is predominantly determined by the minority-carrier lifetime in III-group nitride semiconductors. In this paper, the carrier dynamic process under a stress field was studied for the first time, and the carrier recombination lifetime was calculated within the framework of quantum perturbation theory. Owing to the intrinsic strain due to the lattice mismatch between InGaN and GaN, the wave functions for the holes and electrons are misaligned in an InGaN/GaN device. By applying an external strain that “cancels” the internal strain, the overlap between the wave functions can be maximized so that the lifetime of the carrier is greatly reduced. As a result, the maximum speed of a single chip was increased from 54 MHz up to 117 MHz in a blue LED chip under 0.14% compressive strain. Finally, a bandwidth contour plot depending on the stress and operating wavelength was calculated to guide VLC chip design and stress optimization.

  20. Preliminary investigations of piezoelectric based LED luminary

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Andersen, Michael A. E.; Meyer, Kaspar Sinding

    2011-01-01

    This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS’s (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits......, modulation schemes, LEDs and LED driving conditions are analyzed. A prototype radial mode PT optimized for ZVS (Zero Voltage Switching) is designed. FEM (Final Element Method) and measurements validates the PT design. A prototype PT based AC/DC converter operating from european mains is proposed...

  1. Study on Luminescence Performance of GaN-based μLEDs under High Injection Level%GaN基微米LED大注入条件下发光特性研究

    Institute of Scientific and Technical Information of China (English)

    王溯源; 陶岳彬; 陈志忠; 俞锋; 姜爽; 张国义

    2012-01-01

    The luminescence performance of micro-light emitting diodes(μLEDs) under high injection level was investigated by injection current dependent electroluminescence(EL) and numerical simulations.It is shown in EL measurements that the power output density of μLED(10 μm) seems not saturate under extremely high current density of 16 kA/cm2,and also there is no obvious self-heating-related wavelength redshift under high injection level.The degree of strain relaxation is estimated to be 23% for 10 μm LED based on the blueshift of EL peak under the same injection level as compared to 300 μm LED.APSYS simulations show that the current distribution and carrier concentration are much more homogeneous among the wells for μLED due to strain relaxation and uniform current spreading.These uniform distributions lead to high luminous efficiency and high current density endurance for μLED.%利用变注入强度的电致发光(EL)测试和数值模拟方法研究了微米LED大注入条件下的发光特性。EL测试结果显示,微米LED(10μm)在工作电流密度高达16kA/cm2时光功率密度输出未饱和,同时不存在明显的由于自热效应引起的发光波长红移。和300μm LED相比,相同注入水平下,10μm LED的EL峰值波长相对蓝移,表明微米LED中存在应力弛豫,10μmLED相对300μm LED应力弛豫大了约23%。APYSY模拟发现,由于应力弛豫和良好的电流扩展,微米LED中电流分布和载流子浓度更加均匀,这种均匀的分布使得微米LED具有高的发光效率,同时能够承受高的电流密度。

  2. Research of Ultra-high-power LED Light Source Based on Diamond Thermal Structure%基于金刚石散热结构的超高功率LED光源

    Institute of Scientific and Technical Information of China (English)

    陈欣; 吴懿平

    2014-01-01

    With excellent heat resistance and thermal performance, diamond is the material possessing the highest thermal conductivity in nature. The thermal structures based on diamond can greatly improve the cooling capacity of ultra-high-power LED. Summarize three kinds of diamond thermal structure used in ultra-high-power LED light source: GaN-on-diamond structure integrating light and thermal was realized by combining GaN with diamond directly; structure with diamond film as the powerful dissipation layer added in the traditional LED light source; structure with diamond composite material as LED heat sink. In theory, the heat dissipation effect of the ifrst one is the best among these three structures, whose junction temperature is 40%~45% lower than that of state-of-the-art LED with SiC as substrate.%金刚石是自然界导热率最高的材料,具备极佳的耐热和导热性能。基于金刚石导热的散热结构,大大提高了超高功率LED的散热能力。介绍了三种金刚石散热结构:氮化镓与金刚石直接结合实现GaN-on-diamond光与热集成的结构;在传统的LED光源中增加金刚石薄膜作为高导热层的散热结构;以金刚石复合材料做成的LED热沉结构。理论上,三种结构中第一种结构的散热效果最好,与目前最先进的碳化硅衬底LED相比,其结温降低了40%~45%。

  3. EEG beta power and heart rate variability describe the association between cortical and autonomic arousals across sleep.

    Science.gov (United States)

    Kuo, Terry B J; Chen, Chun-Yu; Hsu, Ya-Chuan; Yang, Cheryl C H

    2016-01-01

    Cortical and autonomic arousals have been found to be closely associated. As arousal events are not evenly dispersed across sleep, we hypothesized the relationship between high frequency electroencephalogram (EEG) power and autonomic arousal indices differ between non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. One night of polysomnographic recording was performed on a group of 18 subjects using a portable recorder. The EEG was collected from C3/Fz. Sleep stages and cortical arousals were visually scored. Cardiac autonomic modulation was assessed from heart rate variability, where the high frequency power (HF) indicates parasympathetic modulation, and the low frequency to high frequency power ratio (LF/HF) represents sympathetic modulation. During NREM sleep, EEG beta power was significantly correlated with LF/HF (r=0.40 ± 0.06), and the relationships were more positive than during REM sleep (LF/HF: r=0.20 ± 0.08; EOG power: r=-0.13 ± 0.05). The relationship of beta power with LF/HF was associated with the incidence of cortical arousal, particularly during NREM sleep. With respect to alpha power, it was only marginally related to HF or LF/HF. In addition, the coefficients of determination were lower for alpha power than for beta power in terms of the relationships to HF, LF/HF and EOG power. This study shows a higher relationship between cortical and autonomic activation during NREM sleep, and the association is better described by beta power. This finding suggests NREM sleep may be of greater therapeutic potential in view of reducing cardiovascular disease associated with sleep fragmentation, and beta power may provide a better index to evaluate the effect.

  4. Developmental Reversals in False Memory: Effects of Emotional Valence and Arousal

    Science.gov (United States)

    Brainerd, C. J.; Holliday, R. E.; Reyna, V. F.; Yang, Y.; Toglia, M. P.

    2010-01-01

    Do the emotional valence and arousal of events distort children's memories? Do valence and arousal modulate counterintuitive age increases in false memory? We investigated those questions in children, adolescents, and adults using the Cornell/Cortland Emotion Lists, a word list pool that induces false memories and in which valence and arousal can…

  5. Pedunculopontine arousal system physiology - Implications for insomnia.

    Science.gov (United States)

    Garcia-Rill, Edgar; Luster, Brennon; Mahaffey, Susan; Bisagno, Veronica; Urbano, Francisco J

    2015-01-01

    We consider insomnia a disorder of waking rather than a disorder of sleep. This review examines the role of the reticular activating system, especially the pedunculopontine nucleus, in the symptoms of insomnia, mainly representing an overactive waking drive. We determined that high frequency activity during waking and REM sleep is controlled by two different intracellular pathways and channel types in PPN cells. We found three different PPN cell types that have one or both channels and may be active during waking only, REM sleep only, or both. These discoveries point to a specific mechanism and novel therapeutic avenues for insomnia.

  6. Avaliação da eficácia clínica de uma nova modalidade de fototerapia utilizando diodos emissores de luz Efficacy of new microprocessed phototherapy system with five high intensity light emitting diodes (Super LED

    Directory of Open Access Journals (Sweden)

    Bianca M. R. Martins

    2007-06-01

    Full Text Available OBJETIVO: Avaliar a eficácia terapêutica de um sistema de fototerapia microprocessada que utiliza diodos emissores de luz (Super LED de alta intensidade no tratamento da hiperbilirrubinemia em recém-nascidos prematuros. MÉTODOS: Ensaio clínico, randomizado e controlado, utilizando a fototerapia Super LED no grupo experimental e duas fototerapias halógenas no grupo controle. A randomização foi realizada em blocos e estratificada por peso de nascimento. A duração da fototerapia e a queda nos níveis séricos de bilirrubina total nas primeiras 24 horas de tratamento foram os principais desfechos analisados. RESULTADOS: Foram estudados 88 recém-nascidos, 44 no grupo da fototerapia Super LED e 44 no grupo da fototerapia halógena. As características demográficas da população foram semelhantes nos dois grupos. O nível sérico médio inicial de bilirrubina no grupo do Super LED (10,1±2,4 mg% foi semelhante ao do grupo que recebeu fototerapia halógena (10,9±2,0 mg%. A queda percentual na concentração sérica de bilirrubina total nas primeiras 24 horas de tratamento foi significativamente maior (27,9 versus 10,7%, p OBJECTIVES: To evaluate the efficacy of a microprocessed phototherapy (PT system with five high intensity light emitting diodes (Super LED for the treatment of neonatal hyperbilirubinemia of premature infants. METHODS: Randomized clinical trial using Super LED phototherapy in the study group and twin halogen spotlight phototherapy in the control group. A stratified blocked randomization, based on birth weight, was performed. The duration of phototherapy and the rate of decrease of total serum bilirubin (TSB concentration in the first 24 hours of treatment were the main outcome measures. RESULTS: We studied 88 infants, 44 in the Super LED group and 44 in the halogen spotlight PT group. The demographic characteristics of the patients in both groups were similar. Infants in the Super LED group had a similar mean initial

  7. Distinguishing specific sexual and general emotional effects in fMRI-subcortical and cortical arousal during erotic picture viewing.

    Science.gov (United States)

    Walter, Martin; Bermpohl, Felix; Mouras, Harold; Schiltz, Kolja; Tempelmann, Claus; Rotte, Michael; Heinze, Hans Jochen; Bogerts, Bernhard; Northoff, Georg

    2008-05-01

    Sexual activity involves excitement with high arousal and pleasure as typical features of emotions. Brain activations specifically related to erotic feelings and those related to general emotional processing are therefore hard to disentangle. Using fMRI in 21 healthy subjects (11 males and 10 females), we investigated regions that show activations specifically related to the viewing of sexually intense pictures while controlling for general emotional arousal (GEA) or pleasure. Activations in the ventral striatum and hypothalamus were found to be modulated by the stimulus' specific sexual intensity (SSI) while activations in the anterior cingulate cortex were associated with an interaction between sexual intensity and emotional valence. In contrast, activation in other regions like the dorsomedial prefrontal cortex, the mediodorsal thalamus and the amygdala was associated only with a general emotional component during sexual arousal. No differences were found in these effects when comparing females and males. Our findings demonstrate for the first time neural differentiation between emotional and sexual components in the neural network underlying sexual arousal.

  8. Ce-Doped La3Si6.5Al1.5N9.5O5.5, a Rare Highly Efficient Blue-Emitting Phosphor at Short Wavelength toward High Color Rendering White LED Application.

    Science.gov (United States)

    Wang, Chun-Yun; Takeda, Takashi; Ten Kate, Otmar Melvin; Tansho, Masataka; Deguchi, Kenzo; Takahashi, Kohsei; Xie, Rong-Jun; Shimizu, Tadashi; Hirosaki, Naoto

    2017-07-12

    Phase pure nondoped and Ce doped La3Si6.5Al1.5N9.5O5.5 (Al containing La N-phase) samples have been obtained by solid-state reaction synthesis for the first time. 1% Ce-doped La3Si6.5Al1.5N9.5O5.5 phosphor displays a broad excitation band ranging from UV to 410 nm, with a maximum at 355 nm. UV light excitation results in a narrow Ce(3+) 5d-4f emission band (fwhm = 68 nm) centered at 418 nm. The emission can be tuned from 417 nm at 0.5% Ce to 450 nm at 50% Ce. A high internal quantum efficiency up to 84% is achieved for a 1% Ce doped sample, which has CIE chromaticity coordinates of x = 0.157 and y = 0.069, close to the NTSC blue standard (x = 0.155; y = 0.070). Compared to La3Si8O4N11:Ce phosphor, the quantum efficiency and thermal stability have been enhanced for La3Si6.5Al1.5N9.5O5.5:Ce phosphor without shifting the emission peak wavelength. La3Si6.5Al1.5N9.5O5.5:Ce shows less thermal quenching than La3Si8O4N11:Ce and no shift or change in the shape of emission spectra with increasing the temperature from 4 to 573 K. These results show that La3Si6.5Al1.5N9.5O5.5:Ce is more efficient than any other (oxy-)nitride phosphor with an emission in the short wavelength blue region (400-450 nm). A white LED was fabricated using the La3Si6.5Al1.5N9.5O5.5:5%Ce as a blue phosphor. The high color rendering index (Ra = 93.2, R9 = 91.4, and R12 = 89.5) obtained shows that the phosphor is a very promising conversion phosphor for white LEDs.

  9. All alone with sweaty palms--physiological arousal and ostracism.

    Science.gov (United States)

    Kelly, Michelle; McDonald, Skye; Rushby, Jacqueline

    2012-03-01

    Social exclusion, or ostracism, is universally perceived as a negative emotional experience and often leads to poor social outcomes for individuals and society. Although the experience of distress associated with being ostracized is innate, there has been very little investigation of the effects on the autonomic nervous system. This study provides objective evidence for the effects of ostracism on arousal (examined with skin conductance levels) while participants played an internet ball-tossing game (Cyberball). Forty-two healthy undergraduate students participated in both inclusion and ostracism conditions. When participants were included, there was a marked decrement in arousal over the course of the task, whereas there was no evidence of habituation when participants were ostracized. The implications of these results are discussed in terms of the potential of differential autonomic activity to predict the coping strategies that people engage in following ostracism.

  10. The DSM diagnostic criteria for female sexual arousal disorder.

    Science.gov (United States)

    Graham, Cynthia A

    2010-04-01

    This article reviews and critiques the DSM-IV-TR diagnostic criteria for Female Sexual Arousal Disorder (FSAD). An overview of how the diagnostic criteria for FSAD have evolved over previous editions of the DSM is presented and research on prevalence and etiology of FSAD is briefly reviewed. Problems with the essential feature of the DSM-IV-TR diagnosis-"an inability to attain, or to maintain...an adequate lubrication-swelling response of sexual excitement"-are identified. The significant overlap between "arousal" and "desire" disorders is highlighted. Finally, specific recommendations for revision of the criteria for DSM-V are made, including use of a polythetic approach to the diagnosis and the addition of duration and severity criteria.

  11. Performance of high power LEDs based on Ce:YAG ceramics for automotive application%基于YAG陶瓷封装的大功率车用LED的发光性能

    Institute of Scientific and Technical Information of China (English)

    张晔明; 芶立; 时佳男; 高江东

    2016-01-01

    5 W blue light LED chips based on InGaN were packaged using the Ce:YAG ceramics with different Ce doping levels. The luminescent properties of packaged LED beads were evaluated. Electroluminescence (EL) spectra of the ceramic-packaged LEDs show that Ce:YAG ceramic is a more compact and efficient fluorescent material. More activation centers of Ce3+can be contained in ceramic with a low doping concentration at a small volume. With a concentration of x=0.03 (Cex:Y3-xAl5O12) and a thickness of 0.4 mm, YAG ceramic-packaged LED shows a high luminous efficiency of 88.2 lm/W. The optical performance of this kind of LEDs based on YAG ceramic makes them promising in automotive headlamps.%不同掺杂量的Ce:YAG陶瓷与5 W蓝光芯片封装后得到发光二极管(LED)灯珠并表征了其发光性能。这种陶瓷灯珠的电致发光光谱结果表明,Ce:YAG陶瓷是一种更加紧凑高效的荧光材料,在较低的Ce3+掺杂量和较小体积下可容纳更多的激活中心。采用Ce3+掺杂量为x=0.03(Cex:Y3-xAl5O12),厚度为0.4 mm的YAG陶瓷封装的LED灯珠发光效率可以达到88.2 lm/W,此种陶瓷灯珠在LED车大灯应用领域有很大潜力。

  12. Design and realization of reflective current barrier for high-brightness LED chips%高亮度LED芯片的反射型电流阻挡层设计与实现

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    基于光学传输理论矩阵,设计制作SiO2和Ti3O5交替生长的分布式布拉格反射(DBR)结构作为LED芯片的电流阻挡层,并采用电感耦合等离子体(ICP)刻蚀技术在电流阻挡层处形成沟槽结构,以解决困扰LED器件效率提高的电流扩散及金属电极降低出光效率的问题。实验结果表明,采用这种结构的LED芯片能将亮度提高5%以上,而LED芯片的正向电压基本维持不变。这种反射型电流阻挡层结构能够很好地改善大尺寸LED芯片的电流扩散,有效地提高LED芯片的出光效率。%Based on optical transfer matrix theory,a distributed Bragg reflector(DBR) consisting of SiO2 and Ti3O5 is designed as the current barrier layer for high-brightness LED chips,and a trench structure is etched by inductively coupled plasma(ICP) technique at the current barrier.The problems that the current spreading restricts the improvement of the LED efficiency and the metal electrodes reduce light-extraction efficiency are solved by this way.The experiment results indicate that the brightness of the LED chip with this structure can be increased by 5%,while the chip voltage is essentially unchanged,which shows that the new structure can greatly ameliorate the current spreading and increase the extraction efficiency of LED chip.

  13. Cognitive-motivational determinants of fat food consumption in overweight and obese youngsters: the implicit association between fat food and arousal.

    Science.gov (United States)

    Craeynest, Mietje; Crombez, Geert; Koster, Ernst H W; Haerens, Leen; De Bourdeaudhuij, Ilse

    2008-09-01

    Cognitive-motivational accounts of fat food intake propose an association between fat food and action dispositions, which are according to the biphasic emotion theory of Lang [(1995). The emotion probe. Studies of motivation and attention. American Psychologist, 50, 372-385; Lang, P.J., Bradley, M.M., & Cuthbert, M.M. (1997). Motivated attention: Affect, activation and action. In P.J. Lang, R.F. Simons & M.T. Balaban (Eds.). Attention and orienting: Sensory and motivational processes (pp. 97-134). Hillsdale, NJ: Lawrence Erlbaum Associates, Inc.] characterized by high levels of arousal. In two experiments, this association was investigated in lean and overweight youngsters. In the first experiment, 29 overweight and 29 lean youngsters conducted two Implicit Association Tasks (IAT; Greenwald, A.G., McGhee, D.E., & Schwartz, J.L. (1998). Measuring individual differences in implicit cognition: The implicit association test. Journal of Personality and Social Psychology, 74, 1464-1480.). In a positive arousal IAT, implicit associations between fat vs. lean food, and high and low arousal words with a positive valence were assessed. In a negative arousal IAT, high and low arousal words with a negative valence were used. A second experiment was conducted to replicate Experiment 1 in 29 youngsters with severe obesity and 29 lean peers. The results revealed strong implicit associations between fat food and arousal in both the overweight and the control group. No differences were found between the groups, nor between the positive and the negative arousal task. These results are related to cognitive-motivational theories of fat food intake.

  14. Personal space invasions in the lavatory: suggestive evidence for arousal.

    Science.gov (United States)

    Middlemist, R D; Knowles, E S; Matter, C F

    1976-05-01

    The hypothesis that personal space invasions produce arousal was investigated in a field experiment. A men's lavatory provided a setting where norms for privacy were salient, where personal space invasions could occur in the case of men urinating, where the opportunity for compensatory responses to invasion were minimal, and where proximity-induced arousal could be measured. Research on micturation indicates that social stressors inhibit relaxation of the external urethral sphincter, which would delay the onset of micturation, and that they increase intravesical pressure, which would shorten the duration of micturation once begun. Sixty lavatory users were randomly assigned to one of three levels of interpersonal distance and their micturation times were recorded. In a three-urinal lavatory, a confederate stood immediately adjacent to a subject, one urinal removed, or was absent. Paralleling the results of a correlational pilot study, close interpersonal distances increased the delay of onset and decreased the persistence of micturation. These findings provide objective evidence that personal space invasions produce physiological changes associated with arousal.

  15. Early brain-body impact of emotional arousal

    Directory of Open Access Journals (Sweden)

    Fabien D'Hondt

    2010-04-01

    Full Text Available Current research in affective neuroscience suggests that the emotional content of visual stimuli activates brain–body responses that could be critical to general health and physical disease. The aim of this study was to develop an integrated neurophysiological approach linking central and peripheral markers of nervous activity during the presentation of natural scenes in order to determine the temporal stages of brain processing related to the bodily impact of emotions. More specifically, whole head magnetoencephalogram (MEG data and skin conductance response (SCR, a reliable autonomic marker of central activation, were recorded in healthy volunteers during the presentation of emotional (unpleasant and pleasant and neutral pictures selected from the International Affective Picture System (IAPS. Analyses of event-related magnetic fields (ERFs revealed greater activity at 180 ms in an occipitotemporal component for emotional pictures than for neutral counterparts. More importantly, these early effects of emotional arousal on cerebral activity were significantly correlated with later increases in SCR magnitude. For the first time, a neuromagnetic cortical component linked to a well-documented marker of bodily arousal expression of emotion, namely, the skin conductance response, was identified and located. This finding sheds light on the time course of the brain–body interaction with emotional arousal and provides new insights into the neural bases of complex and reciprocal mind–body links.

  16. A review of passive thermal management of LED module

    NARCIS (Netherlands)

    Ye, H.; Sau, K.; Zeijl, H. van; Gielen, A.W.J.; Zhang, G.

    2011-01-01

    Recently, the high-brightness LEDs have begun to be designed for illumination application. The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light outpu

  17. Tonic and phasic co-variation of peripheral arousal indices in infants

    Science.gov (United States)

    Wass, S.V.; de Barbaro, K.; Clackson, K.

    2015-01-01

    Tonic and phasic differences in peripheral autonomic nervous system (ANS) indicators strongly predict differences in attention and emotion regulation in developmental populations. However, virtually all previous research has been based on individual ANS measures, which poses a variety of conceptual and methodlogical challenges to comparing results across studies. Here we recorded heart rate, electrodermal activity (EDA), pupil size, head movement velocity and peripheral accelerometry concurrently while a cohort of 37 typical 12-month-old infants completed a mixed assessment battery lasting approximately 20 min per participant. We analysed covariation of these autonomic indices in three ways: first, tonic (baseline) arousal; second, co-variation in spontaneous (phasic) changes during testing; third, phasic co-variation relative to an external stimulus event. We found that heart rate, head velocity and peripheral accelerometry showed strong positive co-variation across all three analyses. EDA showed no co-variation in tonic activity levels but did show phasic positive co-variation with other measures, that appeared limited to sections of high but not low general arousal. Tonic pupil size showed significant positive covariation, but phasic pupil changes were inconsistent. We conclude that: (i) there is high covariation between autonomic indices in infants, but that EDA may only be sensitive at extreme arousal levels, (ii) that tonic pupil size covaries with other indices, but does not show predicted patterns of phasic change and (iii) that motor activity appears to be a good proxy measure of ANS activity. The strongest patterns of covariation were observed using epoch durations of 40 s per epoch, although significant covariation between indices was also observed using shorter epochs (1 and 5 s). PMID:26316360

  18. Anger regulation style, anger arousal and acute pain sensitivity: evidence for an endogenous opioid "triggering" model.

    Science.gov (United States)

    Burns, John W; Bruehl, Stephen; Chont, Melissa

    2014-08-01

    Findings suggest that greater tendency to express anger is associated with greater sensitivity to acute pain via endogenous opioid system dysfunction, but past studies have not addressed the role of anger arousal. We used a 2 × 2 factorial design with Drug Condition (placebo or opioid blockade with naltrexone) crossed with Task Order (anger-induction/pain-induction or pain-induction/anger-induction), and with continuous Anger-out Subscale scores. Drug × Task Order × Anger-out Subscale interactions were tested for pain intensity during a 4-min ischemic pain task performed by 146 healthy people. A significant Drug × Task Order × Anger-out Subscale interaction was dissected to reveal different patterns of pain intensity changes during the pain task for high anger-out participants who underwent pain-induction prior to anger-induction compared to those high in anger-out in the opposite order. Namely, when angered prior to pain, high anger-out participants appeared to exhibit low pain intensity under placebo that was not shown by high anger-out participants who received naltrexone. Results hint that people with a pronounced tendency to express anger may suffer from inadequate opioid function under simple pain-induction, but may experience analgesic benefit to some extent from the opioid triggering properties of strong anger arousal.

  19. Comparative analysis of high pressure sodium vapor lamps and mercury vapor lamp with the solid state (LED) in the public lighting systems; Analise comparativa das lampadas de vapor de sodio a alta pressao e de vapor de mercurio com a lampada a estado solido (LED) em sistemas de iluminacao publica

    Energy Technology Data Exchange (ETDEWEB)

    Damato, J.C.; Bueno, J.E.; Astorga, O.A.M. [Universidade Estadual Paulista (LESIP/UNESP), Guaratingueta, SP (Brazil). Lab. de Eficiencia Energetica em Sistemas de Iluminacao Publica; Ricciulli, D.L.S. [Universidade Estadual Paulista (DEE/UNESP), Guaratingueta, SP (Brazil). Dept. de Engenharia Eletrica

    2009-07-01

    The necessity of energy conservation in Brazilian electric sector, with the intention to diminish the resources of generation investments, has going to use of electric energy conservation programs, being most important PROCEL - a national program of electric conservation energy by ELETROBRAS, and inside this, a national program for public illumination and efficient traffic signaling - named 'Reluz'. This program looks for a more efficient implantation of public lighting systems, that requires the use of lamp technologies that present a greater value in a relation between lumen/watt relation and then beyond providing economy, due to low consumption of electric energy. Besides technologies that are appearing, the inclusion of LED lamps, which offers a great application potential, comes blunting as improvement alternative, being that the next public illumination parks will be able count on these lamps associates to the high-pressure sodium lamps and other types currently used. (author)

  20. Effects of music on arousal during imagery in elite shooters: A pilot study.

    Science.gov (United States)

    Kuan, Garry; Morris, Tony; Terry, Peter

    2017-01-01

    Beneficial effects of music on several performance-related aspects of sport have been reported, but the processes involved are not well understood. The purpose of the present study was to investigate effects of relaxing and arousing classical music on physiological indicators and subjective perceptions of arousal during imagery of a sport task. First, appropriate music excerpts were selected. Then, 12 skilled shooters performed shooting imagery while listening to the three preselected music excerpts in randomized order. Participants' galvanic skin response, peripheral temperature, and electromyography were monitored during music played concurrently with imagery. Subjective music ratings and physiological measures showed, as hypothesized, that unfamiliar relaxing music was the most relaxing and unfamiliar arousing music was the most arousing. Researchers should examine the impact of unfamiliar relaxing and arousing music played during imagery on subsequent performance in diverse sports. Practitioners can apply unfamiliar relaxing and arousing music with imagery to manipulate arousal level.

  1. Research on Fluid Motion and Fluid Jetting Dispensing in High Performance Manufacturing of LED%高性能LED封装点胶中流体运动与胶液喷射研究

    Institute of Scientific and Technical Information of China (English)

    彭先安; 单修洋; 沈平; 李涵雄

    2014-01-01

    LED照明具有高亮度、低能耗、体积小、环保等特点,因此被认为是未来替代传统照明方式的最佳光源。而对于高粘度、高频、微量、高一致性的LED荧光粉点胶,目前还存在无法出胶、点胶性能不稳定、胶滴一致性不好等问题。首先阐述了LED照明的应用特点以及当前照明封装产业的技术水平,随后结合将来主流的喷射式点胶技术,利用Flow-3D软件建立了LED喷射点胶过程的计算机仿真模型。随后得到了点胶过程中胶液在喷胶阀内的流动情况,在此基础上又探讨了各因素对胶液喷射的影响规律。其结果可以为后续的研究奠定基础,同时对具体的LED工业生产及封装装备制造也有一定的参考价值。%LED lighting has high brightness, low power consumption, small size, environmental protection and other features, so it is considered to be the best source of future lighting method. For high viscosity, high frequency, high consistency of the LED phosphor dispensing, there are still some problems.Such as can’t jet glue, glue performance is not stable, dots consistency is not good and so on.The paper first describes the characteristics of LED lighting and the lighting package industry technical level, and then combined with the future mainstream jet dispensing technology, establish a computer simulation model of the LED jet dispensing process by using Flow-3D software. Then obtain the flow situation of glue dispensing process in the spray valve, and on the basis of it, discuss the factors to the glue injection. The results can lay a foundation for related research, also has certain reference function to the concrete LED industrial production and packaging equipment manufacturing.

  2. Affordable underwater wireless optical communication using LEDs

    Science.gov (United States)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  3. Broadband white light emission from Ce:AlN ceramics: High thermal conductivity down-converters for LED and laser-driven solid state lighting

    Science.gov (United States)

    Wieg, A. T.; Penilla, E. H.; Hardin, C. L.; Kodera, Y.; Garay, J. E.

    2016-12-01

    We introduce high thermal conductivity aluminum nitride (AlN) as a transparent ceramic host for Ce3+, a well-known active ion dopant. We show that the Ce:AlN ceramics have overlapping photoluminescent (PL) emission peaks that cover almost the entire visible range resulting in a white appearance under 375 nm excitation without the need for color mixing. The PL is due to a combination of intrinsic AlN defect complexes and Ce3+ electronic transitions. Importantly, the peak intensities can be tuned by varying the Ce concentration and processing parameters, causing different shades of white light without the need for multiple phosphors or light sources. The Commission Internationale de l'Eclairage coordinates calculated from the measured spectra confirm white light emission. In addition, we demonstrate the viability of laser driven white light emission by coupling the Ce:AlN to a readily available frequency tripled Nd-YAG laser emitting at 355 nm. The high thermal conductivity of these ceramic down-converters holds significant promise for producing higher power white light sources than those available today.

  4. Broadband white light emission from Ce:AlN ceramics: High thermal conductivity down-converters for LED and laser-driven solid state lighting

    Directory of Open Access Journals (Sweden)

    A. T. Wieg

    2016-12-01

    Full Text Available We introduce high thermal conductivity aluminum nitride (AlN as a transparent ceramic host for Ce3+, a well-known active ion dopant. We show that the Ce:AlN ceramics have overlapping photoluminescent (PL emission peaks that cover almost the entire visible range resulting in a white appearance under 375 nm excitation without the need for color mixing. The PL is due to a combination of intrinsic AlN defect complexes and Ce3+ electronic transitions. Importantly, the peak intensities can be tuned by varying the Ce concentration and processing parameters, causing different shades of white light without the need for multiple phosphors or light sources. The Commission Internationale de l’Eclairage coordinates calculated from the measured spectra confirm white light emission. In addition, we demonstrate the viability of laser driven white light emission by coupling the Ce:AlN to a readily available frequency tripled Nd-YAG laser emitting at 355 nm. The high thermal conductivity of these ceramic down-converters holds significant promise for producing higher power white light sources than those available today.

  5. 负偏压法测试大电压LED器件热阻%Measuring thermal resistance for high voltage LED device and module by applying negative bias voltage

    Institute of Scientific and Technical Information of China (English)

    陈国龙; 雷瑞瑞; 陈焕庭; 陈莹亮; 吕毅军; 高玉琳; 朱丽虹; 陈忠

    2012-01-01

    热阻是衡量LED器件散热性能的重要热学参数.采用外接负偏压恒压源方法,分别使用T3Ster/Teraled热光参数测试仪和NC2991热阻仪对正向电压超过仪器量程的同一型号功率型LED的热阻进行测试,并对两种测试结果的误差进行比较分析讨论.该方法拓展了热阻仪测量范围,使正向电压大于5V的LED器件/模块的热阻测试成为可能.%Thermal resistance is a key parameter on rating the heat dissipating capability of LEDs, so its measurement becomes particularly essential. A thermal resistance measurement method for high voltage LED device and module is provided here, which can measure LED sample with forward voltage larger than 5V by applying negative bias voltage to the T3Ster/Teraled and the NC2991 thermal resistance testers respectively. The results are further compared and discussed and prove to effectively expand the testing range of thermal resistance tester.

  6. 外部电压源法测试大电压LED器件/模块热阻%Measuring thermal resistance for high voltage LED device and module by applying ex ternal voltage source

    Institute of Scientific and Technical Information of China (English)

    陈国龙; 朱丽虹; 郭自泉; 张纪红; 吕毅军; 高玉琳; 陈忠

    2013-01-01

    热阻是衡量LED器件/模块散热性能的重要参数。针对大电压LED器件/模块,实验采用 T3Ster/T eraled热光参数测试仪,利用外部电压源供电方法,实现了对超过仪器量程的大电压L ED器件的热阻测试。该方法拓展了热阻测试仪的常规测量范围,使正向电压大于15 V的L ED器件/模块的热阻测试成为可能。%Thermal resistance is a key parameter for evaluating thermal performance of LED device/module . Reliable measurement of thermal resistance becomes extremely important .Aiming at that the high voltage LED device/module has been applied popularly in lighting ,an improved thermal resistance measurement method for LED device/module with forward voltage larger than 15V is achieved by applying external voltage source to the T3Ster/Teraled .The result shows that the external voltage source method can effectively expand the testing range of thermal resistance tester .

  7. Phosphors and PDP, LED Technology

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Phosphors for PDP has good prospect for the largepotential of PDP industry. LED technology brings new marketto be developed. Developing phosphors for white LED withhigh efficiency and low light attenuation is an urgent work todo. Application of phosphors in color LED is in initial stage.1. Good Prospect of Phosphors for PDPColor PDP is widely used today. Three-prime-colorphosphor excited by VUV is the key material for color PDP.This makes research on three-prime-color phosphor for colorPDP important. Follow...

  8. Israeli 'cancer shift' over heart disease mortality may be led by greater risk in women with high intake of n-6 fatty acids.

    Science.gov (United States)

    Shapira, Niva

    2007-10-01

    My hypothesis is that higher female sensitivity to increased n-6 polyunsaturated fatty acids and their carcinogenic effect may contribute to the recent Israeli 'cancer shift' over heart disease mortality (23.1 vs. 22.3%, 1999). High n-6 polyunsaturated fatty acid intake was the presumed dietary risk underlying the 'Israeli paradox', the unexpected gap between 'ill' health and 'good' diet. Scientific literature and population health surveillance reports were reviewed. Cancer death rates for Israeli Arabs, who consumed a more traditional Mediterranean diet - more monounsaturated fatty acids, mostly olive oil, and less n-6 polyunsaturated fatty acids - are still 1.1-1.7 times (men-women) lower than in Israeli Jews, but are increasing faster (23.6 and 5.1% vs. 5.3 and -3.3%, 1980-2000), concurrently with dietary 'Israelization' - specifically, increased intake of n-6 polyunsaturated fatty acids. Israeli-Jewish women attained an earlier, much larger (29 vs. 7%, 1999) 'cancer : heart disease mortality shift' (ratio >1.0), ranked much worse for cancer (15th/44 European countries) than men (37th) and heart disease (38th and 34th, respectively), and had much higher cancer prevalence (1 : 3) than Israeli-Arab women (1 : 6), though dietary compositions were similar, save for higher n-6 polyunsaturated fatty acid and polyunsaturated fatty acid : monounsaturated fatty acid ratio. Population studies of Israeli Jews, Arabs, and women support the association of high n-6 polyunsaturated fatty acid intake with increased cancer risk and higher female sensitivity. Research findings suggest that gender and sex hormones may influence n-6 polyunsaturated fatty acid metabolism and carcinogenesis. This appears to be the first time gender has been proposed to modulate national cancer epidemiology, suggesting implications for differential nutritional prevention, warranting further research.

  9. Design of a High-Sensitivity LED Lamp of Sound-and-Light-Controlled Type with Micro-Power Consumption%微功耗高灵敏度声光控制型LED照明灯的设计

    Institute of Scientific and Technical Information of China (English)

    金永镐; 金杰

    2012-01-01

    利用MK6A11P的微功耗特性,设计了具有微功耗、声光控制、高灵敏度的LED照明灯。其具有〈0.1 W的待机功耗、灵敏度高,克服了现有声控灯灵敏度过低的问题。同时解决了声控灵敏度高时产生的常亮现象,可广泛应用于人群流动较为随机的公共场所,如走廊、电梯口、公共卫生间等。经实验证明,这种LED照明灯具有电路简单、工作稳定可靠、点亮时间可调等优点。%On the basis of MK6A11P's characteristic of micro-power consumption, this paper designs an LED lamp with the characteristics of micro-power consumption, sound and light control and high sensitivity. It has a standby power consumption of less than 0. 1 W and high sensitivity, thus overcoming the problem of the existing a- coustic-control lamp of low sensitivity and also dealing with the problem that the lamp is always lighting when the sen- sitivity of acoustic control is high. The LED lamp can be widely used in public areas where the flow of people chan- ges at random such as corridors, elevator entrance and public toilet. Experiments show that the LED lamp has the advantages of simple circuit structure, high operation stability and adjustable lighting time.

  10. High dynamic range measurement of spectral responsivity and linearity of a radiation thermometer using a super-continuum laser and LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y. S.; Lee, D. H.; Park, C. W.; Park, S. N. [Korea Research Institute of Standards and Science 209 Gajeong-Ro, Yuseong-Gu, Daejon 305-340 (Korea, Republic of)

    2013-09-11

    To realize the temperature scale above the freezing point of silver according to the definition of ITS-90, the dynamic range of the spectral responsivity is one of the most important factors which limit its uncertainty. When the residual spectral response at both side bands of a spectral band is not negligible, a significant uncertainty can be caused by a low dynamic range of the spectral responsivity measurement. In general, incandescent lamps are used to measure the spectral responsivity and the linearity. The dynamic range of the spectral responsivity measurement is often limited by a trade-off with the desired spectral resolution, which is less than 6 decades. Nonlinearity is another limiting fact of uncertainties of the temperature scale. Tungsten lamps have disadvantage in the nonlinearity measurements in terms of adjustability of radiance level and spectral selectivity. We report spectral responsivity measurements of which the measurable dynamic range is enhanced 50 times after replacing a QTH lamp with a super continuum laser. We also present a spectrally selected linearity measurement over a wide dynamic range using high-brightness light emitting diode arrays to observe a slight saturation of linearity.

  11. Celebrity-led Development Organisations

    DEFF Research Database (Denmark)

    Budabin, Alexandra Cosima; Rasmussen, Louise Mubanda; Richey, Lisa Ann

    2017-01-01

    The past decade has seen a frontier open up in international development engagement with the entrance of new actors such as celebrity-led organisations. We explore how such organisations earn legitimacy with a focus on Madonna’s Raising Malawi and Ben Affleck’s Eastern Congo Initiative. The study...... for funding, endorsements, and expertise. We argue that the ways in which celebrity-led organisations establish themselves as legitimate development actors illustrate broader dynamics of the machinery of development....

  12. Practical lighting design with LEDs

    CERN Document Server

    Lenk, Ron

    2016-01-01

    The second edition of Practical Lighting Design with LEDs has been revised and updated to provide the most current information for developing light-emitting diodes products. The authors, noted authorities in the field, offer a review of the most relevant topics including optical performance, materials, thermal design, and modeling and measurement. Comprehensive in scope, the text covers all the information needed to design LEDs into end products.

  13. High-quality uniaxial In(x)Ga(1-x)N/GaN multiple quantum well (MQW) nanowires (NWs) on Si(111) grown by metal-organic chemical vapor deposition (MOCVD) and light-emitting diode (LED) fabrication.

    Science.gov (United States)

    Ra, Yong-Ho; Navamathavan, R; Park, Ji-Hyeon; Lee, Cheul-Ro

    2013-03-01

    This article describes the growth and device characteristics of vertically aligned high-quality uniaxial p-GaN/InxGa1-xN/GaN multiple quantum wells (MQW)/n-GaN nanowires (NWs) on Si(111) substrates grown by metal-organic chemical vapor deposition (MOCVD) technique. The resultant nanowires (NWs), with a diameter of 200-250 nm, have an average length of 2 μm. The feasibility of growing high-quality NWs with well-controlled indium composition MQW structure is demonstrated. These resultant NWs grown on Si(111) substrates were utilized for fabricating vertical-type light-emitting diodes (LEDs). The steep and intense photoluminescence (PL) and cathodoluminescence (CL) spectra are observed, based on the strain-free NWs on Si(111) substrates. High-resolution transmission electron microscopy (HR-TEM) analysis revealed that the MQW NWs are grown along the c-plane with uniform thickness. The current-voltage (I-V) characteristics of these NWs exhibited typical p-n junction LEDs and showed a sharp onset voltage at 2.75 V in the forward bias. The output power is linearly increased with increasing current. The result indicates that the pulsed MOCVD technique is an effective method to grow uniaxial p-GaN/InxGa1-xN/GaN MQW/n-GaN NWs on Si(111), which is more advantageous than other growth techniques, such as molecular beam epitaxy. These results suggest the uniaxial NWs are promising to allow flat-band quantum structures, which can enhance the efficiency of LEDs.

  14. Low emotional arousal in depression as explained by the motivated attention approach (La baja activación emocional en la depresión explicada por el enfoque de la atención motivada

    Directory of Open Access Journals (Sweden)

    Stephan Moratti

    2012-08-01

    Full Text Available Depression has been associated with low emotional arousal. Highly arousing emotional stimuli engage the cortical circuits related to the allocation of attention towards these stimuli. Thus, it has been hypothesized that depression could be characterized by a deficit in these brain circuits. This brief review summarizes how attention and emotion are interconnected and suggests that common brain mechanisms underlie the link between emotion and attention. Finally, the results from depression research are presented that show that low emotional arousal in depression could arise from a deficit in brain circuits related to attention.

  15. GaN-Based White-Light-Emitting Diodes with Low Color Temperature and High Color Rendering Index%GaN基低色温高显色白光LED

    Institute of Scientific and Technical Information of China (English)

    王峰; 黄小辉; 王怀兵; 刘建平; 范亚明; 祝运芝; 金铮

    2011-01-01

    采用440nm短波长InGaN/GaN基蓝光LED芯片激发高效红、绿荧光粉制得高显色性白光LFD,研究了不同胶粉配比对LED发光性能的影响,结果表明,A胶、B胶、绿粉、红粉比重在0.5∶0.5∶0.2∶0.03时,在440 m蓝光激发下呈现了有两个谱带组成的发光光谱,分别是峰值为535 nm的特征光谱和643nm的特征光谱,胶粉通过均匀调配后能够有效的进行混光产生低色温白光,实验中最低色温可达3 251K,显色指数高达88.8,这比传统蓝光激发YAG荧光粉制得的白光LED色温更低,显色指数提高了26%.%The luminescence properties of high color rendering white LED depending on the proportions of mixed phosphor powders were investigated by adopting green and red phosphors stimulated by a 440 nm InGaN/GaN based blue LED. The results show that when the proportion of A/B type silica gels and green/red phosphor powders is 0.5: 0.5: 0.2: 0.03, two luminance bands are stimulated and their wavelength peaks are 535 and 643 nm, respectively. The minimum color temperature can reach 3 251 K, while the color rendering is as high as 88.8. Compared with the traditional white LED fabricated by yellow YAG-phosphors-coated high efficiency 460 nm blue LED, the color temperature is lower and the color rendering index can be increased by almost 26%.

  16. An LED Solar Simulator for Student Labs

    Science.gov (United States)

    González, Manuel I.

    2017-01-01

    Measuring voltage-current and voltage-power curves of a photovoltaic module is a nice experiment for high school and undergraduate students. In labs where real sunlight is not available this experiment requires a solar simulator. A prototype of a simulator using LED lamps has been manufactured and tested, and a comparison with classical halogen…

  17. Modeling of spectral characteristics of blue LEDs

    DEFF Research Database (Denmark)

    Thorseth, Anders

    2010-01-01

    are expected to vary with current and junction temperature. Commercial high power blue LEDs were measured with respect to spectral distribution and chromaticity and the result was compared with the model predictions. We have found that the models predict significantly different results with respect...

  18. Preliminary investigations of piezoelectric based LED luminary

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Andersen, Michael A. E.; Meyer, Kaspar Sinding

    2011-01-01

    This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS’s (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits, modul...

  19. Light out-coupling from LEDs by means of metal nanoparticles; Lichtauskopplung aus LEDs mittels Metallnanoteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Goehler, Tino

    2010-12-17

    The external quantum efficiency of light-emitting diodes (LEDs) based on Al- GaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called ''Fischer pattern nanolithography'' and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data. (orig.)

  20. An LED solar simulator for student labs

    Science.gov (United States)

    González, Manuel I.

    2017-05-01

    Measuring voltage-current and voltage-power curves of a photovoltaic module is a nice experiment for high school and undergraduate students. In labs where real sunlight is not available this experiment requires a solar simulator. A prototype of a simulator using LED lamps has been manufactured and tested, and a comparison with classical halogen simulators has been performed. It is found that LED light offers lower levels of irradiance, but much better performance in terms of module output for a given irradiance.

  1. Monolithic Integration of GaN-based LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Ao, Jin-Ping, E-mail: jpao@ee.tokushima-u.ac.jp [Institute of Technology and Science, University of Tokushima 2-1 Minami-Josanjima, Tokushima 770-8506 (Japan)

    2011-02-01

    The technology of monolithically integrated GaN-based light-emitting diodes (LEDs) is reported. First, the technology details to realize monolithic integration are described, including the circuit design for high-voltage and alternating current (AC) operation and the technologies for device isolation. The performances of the fabricated monolithic LED arrays are then demonstrated. A monolithic series array with totally 40 LEDs exhibited expected operation function under AC bias. The operation voltage of the array is 72 V when 20 LEDs were connected in series. Some modified circuit designs for high-voltage operation and other monolithic LED arrays are finally reviewed.

  2. LED packaging for lighting applications design, manufacturing, and testing

    CERN Document Server

    Liu, Sheng

    2011-01-01

    Since the first light-emitting diode (LED) was invented by Holonyak and Bevacqua in 1962, LEDs have made remarkable progress in the past few decades with the rapid development of epitaxy growth, chip design and manufacture, packaging structure, processes, and packaging materials. LEDs have superior characteristics such as high efficiency, small size, long life, low power consumption, and high reliability. The market for white LED is growing rapidly in various applications. It has been widely accepted that white LEDs will be the fourth illumination source to substitute the incandescent, fluores

  3. Extremism reduces conflict arousal and increases values affirmation in response to meaning violations.

    Science.gov (United States)

    Sleegers, Willem W A; Proulx, Travis; van Beest, Ilja

    2015-05-01

    In the social psychological threat-compensation literature, there is an apparent contradiction whereby relatively extreme beliefs both decrease markers of physiological arousal following meaning violations, and increase the values affirmation behaviors understood as a palliative responses to this arousal. We hypothesize that this is due to the differential impact of measuring extremism on behavioral inhibition and approach systems following meaning violations, whereby extremism both reduces markers of conflict arousal (BIS) and increases values affirmation (BAS) unrelated to this initial arousal. Using pupil dilation as a proxy for immediate conflict arousal, we found that the same meaning violation (anomalous playing cards) evoked greater pupil dilation, and that this pupillary reaction was diminished in participants who earlier reported extreme beliefs. We also found that reporting extreme beliefs was associated with greater affirmation of an unrelated meaning framework, where this affirmation was unrelated to physiological markers of conflict arousal. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Design of Narrow pulse and High current LED Strobe Light Based on FPGA Platform%基于FPGA平台的窄脉冲大电流LED频闪光源设计

    Institute of Scientific and Technical Information of China (English)

    王飞橙; 轩建平; 李新亮

    2014-01-01

    针对高频信号的特点,利用 FPGA,设计了一种窄脉宽、大电流的LED频闪光源。通过 FP-GA平台上的编程控制,实现了满足频闪光源控制时序要求的窄脉宽信号。最后,将窄脉宽信号进行电流放大,获得脉宽为ns级,电流最大可达30 A的LED驱动脉冲信号。%In allusion to high frequency signals, design a narrow pulse and high current LED strobe light based on FPGA platform.By program-ming of the FPGA platform,generate the narrow pulse signal that meet timing requirements of strobe light control.Finally,through the current amplification,we obtain the LED drive pulse signal which pulse width reaches ns level,and its current up to 30A.

  5. The dynamic opponent relativity model: an integration and extension of capacity theory and existing theoretical perspectives on the neuropsychology of arousal and emotion.

    Science.gov (United States)

    Comer, Clinton S; Harrison, Patti Kelly; Harrison, David W

    2015-01-01

    Arousal theory as discussed within the present paper refers to those mechanisms and neural systems involved in central nervous system activation and more specifically the systems involved in cortical activation. Historical progress in the evolution of arousal theory has led to a better understanding of the functional neural systems involved in arousal or activation processes and ultimately contributed much to our current theories of emotion. Despite evidence for the dynamic interplay between the left and right cerebral hemispheres, the concepts of cerebral balance and dynamic activation have been emphasized in the neuropsychological literature. A conceptual model is proposed herein that incorporates the unique contributions from multiple neuropsychological theories of arousal and emotion. It is argued that the cerebral hemispheres may play oppositional roles in emotion partially due to the differences in their functional specializations and in their persistence upon activation. In the presence of a threat or provocation, the right hemisphere may activate survival relevant responses partially derived from hemispheric specializations in arousal and emotional processing, including the mobilization of sympathetic drive to promote heightened blood pressure, heart rate, glucose mobilization and respiratory support necessary for the challenge. Oppositional processes and mechanisms are discussed, which may be relevant to the regulatory control over the survival response; however, the capacity of these systems is necessarily limited. A limited capacity mechanism is proposed, which is familiar within other physiological systems, including that providing for the prevention of muscular damage under exceptional demand. This capacity theory is proposed, wherein a link may be expected between exceptional stress within a neural system and damage to the neural system. These mechanisms are proposed to be relevant to emotion and emotional disorders. Discussion is provided on the

  6. Migraine, arousal and sleep deprivation: comment on: "sleep quality, arousal and pain thresholds in migraineurs: a blinded controlled polysomnographic study".

    Science.gov (United States)

    Vollono, Catello; Testani, Elisa; Losurdo, Anna; Mazza, Salvatore; Della Marca, Giacomo

    2013-06-10

    We discuss the hypothesis proposed by Engstrom and coworkers that Migraineurs have a relative sleep deprivation, which lowers the pain threshold and predispose to attacks. Previous data indicate that Migraineurs have a reduction of Cyclic Alternating Pattern (CAP), an essential mechanism of NREM sleep regulation which allows to dump the effect of incoming disruptive stimuli, and to protect sleep. The modifications of CAP observed in Migraineurs are similar to those observed in patients with impaired arousal (narcolepsy) and after sleep deprivation. The impairment of this mechanism makes Migraineurs more vulnerable to stimuli triggering attacks during sleep, and represents part of a more general vulnerability to incoming stimuli.

  7. Does the arousal system contribute to near death experience?

    Science.gov (United States)

    Nelson, Kevin R; Mattingly, Michelle; Lee, Sherman A; Schmitt, Frederick A

    2006-04-11

    The neurophysiologic basis of near death experience (NDE) is unknown. Clinical observations suggest that REM state intrusion contributes to NDE. Support for the hypothesis follows five lines of evidence: REM intrusion during wakefulness is a frequent normal occurrence, REM intrusion underlies other clinical conditions, NDE elements can be explained by REM intrusion, cardiorespiratory afferents evoke REM intrusion, and persons with an NDE may have an arousal system predisposing to REM intrusion. To investigate a predisposition to REM intrusion, the life-time prevalence of REM intrusion was studied in 55 NDE subjects and compared with that in age/gender-matched control subjects. Sleep paralysis as well as sleep-related visual and auditory hallucinations were substantially more common in subjects with an NDE. These findings anticipate that under circumstances of peril, an NDE is more likely in those with previous REM intrusion. REM intrusion could promote subjective aspects of NDE and often associated syncope. Suppression of an activated locus ceruleus could be central to an arousal system predisposed to REM intrusion and NDE.

  8. Optimization Design on Packaging Materials of High-power LED for Lighting%照明用大功率发光二极管封装材料的优化设计

    Institute of Scientific and Technical Information of China (English)

    刘一兵; 戴瑜兴; 黄志刚

    2011-01-01

    According to heat transfer theory, a finite element model of high-power light emitting diode (LED) was established. Four kinds of bonding materials(silver conductive adhesive with high thermal conductivity, nano-silver paste, power chip bonding adhesive, Sn70Pb30), and four kinds of substrate material(Al2O3, AlN, Al-SiC, copper-molybdenum alloy)were chosen. ANSYS finite element thermal analysis software was used to simulate temperature field, and the optimal choice of materials for highpower LED package was obtained. The influences of the substrate thickness, chip output power and external heat sink on the LED junction temperature were studied. The results show that the nanometer silver soldering paste-AlN has the most superior radiation effect the increase of the substrate thickness will not increase the head dissipation capability obviously; because the signal LED output power is limited, the packaging structure should be optimized and the multi-chip array needs to be used to the illumination requirement; the external aluminum heat-sinking is able to achieve the ideal heat-sinking effect.%根据传热理论,建立了大功率发光二极管的有限元模型.选择了4种键合材料(高导热导电银胶、纳米银焊膏,大功率芯片键合胶、Sn70Pb30),4种基板材料(Al2O3、AlN、Al-SiC、铜钼合金).采用ANSYS有限元热分析软件进行了温度场仿真,得到了大功率发光二极管封装材料的最优选择.研究了基板厚度、芯片输出功率及外接热沉时对发光二极管结温的影响.结果表明:纳米银焊膏-AlN组合具有最优的散热效果;增加散热基板厚度提高散热能力的作用不大;单个发光二极管输出功率有限,应优化封装结构并采用多芯片阵列来满足照明级的需要;外接铝热沉能达到理想的散热效果.

  9. Linkages between NAMA - LEDS - MRV

    DEFF Research Database (Denmark)

    Agyemang-Bonsu, William; Benioff, Ron; Cox, Sadie

    Low Emission Development Strategies (LEDS), Nationally Appropriate Mitigation Actions (NAMAs) and Monitoring, Reporting and Verification (MRV) are three of the key conceptual components emerging as part of the global architecture for a new climate agreement by 2015. The three components are devel......Low Emission Development Strategies (LEDS), Nationally Appropriate Mitigation Actions (NAMAs) and Monitoring, Reporting and Verification (MRV) are three of the key conceptual components emerging as part of the global architecture for a new climate agreement by 2015. The three components...... how the three components are conceptually interlinked. Identifying the linkages can inform the work on each component and strengthen coordination of work in the context of the three big partnerships; the International Partnership on Mitigation and MRV, the LEDS Global Partnership and the NAMA...

  10. Impurity Influence on Nitride LEDs

    Directory of Open Access Journals (Sweden)

    O.I. Rabinovich

    2014-07-01

    Full Text Available Light emitting diodes (LEDs are widely used nowadays. They are used in major parts of our life. But it is still necessary to improve their characteristics. In this paper the impurity and Indium atoms influence on the LEDs characteristics is investigated by computer simulation. Simulation was carried out in Sim Windows. The program was improved for this purpose by creating new files for AlGaInN heterostructure and devices including more than 25 basic parameters. It was found that characteristics depend on impurity and indium atoms changes a lot. The optimum impurity concentration for doping barriers between quantum wells was achieved. By varying impurity and Indium concentration the distribution in AlGaInN heterostructure LEDs characteristics could be improved.

  11. Prenatal cocaine exposure effects on arousal-modulated attention during the neonatal period.

    Science.gov (United States)

    Karmel, B Z; Gardner, J M

    1996-07-01

    The organization of arousal and attention as a function of intrauterine cocaine exposure was investigated in 180 normal nursery infants prior to hospital discharge and at 1 month of age. This was done by studying visual looking preferences when infants were in three arousal conditions: less aroused (after feeding); more aroused-endogenous (before feeding); and more aroused-exogenous (after feeding but including 8-Hz visual stimulation prior to each visual preference trial). The stimuli were light panels illuminated at three temporal frequencies between 1 and 8 Hz presented in pairs using a balanced presentation series of trials. Infants not exposed to cocaine demonstrated strong arousal-modulated attention, preferring faster frequencies when less aroused and slower frequencies when more aroused in both endogenous and exogenous conditions. In contrast, cocaine-exposed infants showed a lack of arousal-modulated attention and preferred faster frequencies of stimulation regardless of arousal condition. Similar differences in arousal-modulated attention as a function of cocaine exposure were obtained at 1 month after birth, indicating that these effects lasted longer than would be reasonable to attribute to the active presence of cocaine or its metabolites. This form of stimulus-seeking behavior was shown to be independent of confounding factors associated with prenatal cocaine exposure such as the absence of prenatal care, alcohol use, minority status, or gender, as well as mediating factors associated with growth such as birthweight. A direct and more chronic effect of intrauterine cocaine exposure on arousal-modulated attention and presumably on the developing CNS therefore was supported.

  12. Norms of valence, arousal, dominance, and age of acquisition for 4,300 Dutch words.

    Science.gov (United States)

    Moors, Agnes; De Houwer, Jan; Hermans, Dirk; Wanmaker, Sabine; van Schie, Kevin; Van Harmelen, Anne-Laura; De Schryver, Maarten; De Winne, Jeffrey; Brysbaert, Marc

    2013-03-01

    This article presents norms of valence/pleasantness, activity/arousal, power/dominance, and age of acquisition for 4,300 Dutch words, mainly nouns, adjectives, adverbs, and verbs. The norms are based on ratings with a 7-point Likert scale by independent groups of students from two Belgian (Ghent and Leuven) and two Dutch (Rotterdam and Leiden-Amsterdam) samples. For each variable, we obtained high split-half reliabilities within each sample and high correlations between samples. In addition, the valence ratings of a previous, more limited study (Hermans & De Houwer, Psychologica Belgica, 34:115-139, 1994) correlated highly with those of the present study. Therefore, the new norms are a valuable source of information for affective research in the Dutch language.

  13. Semiconductor lasers and herterojunction leds

    CERN Document Server

    Kressel, Henry

    2012-01-01

    Semiconductor Lasers and Heterojunction LEDs presents an introduction to the subject of semiconductor lasers and heterojunction LEDs. The book reviews relevant basic solid-state and electromagnetic principles; the relevant concepts in solid state physics; and the p-n junctions and heterojunctions. The text also describes stimulated emission and gain; the relevant concepts in electromagnetic field theory; and the modes in laser structures. The relation between electrical and optical properties of laser diodes; epitaxial technology; binary III-V compounds; and diode fabrication are also consider

  14. The effect of personality type and musical task on self-perceived arousal.

    Science.gov (United States)

    Lim, Hayoung A

    2008-01-01

    This study was designed to measure the level of arousal influenced by 4 different musical experiences classified by task difficulty and to examine the relationship between music-induced arousal level and personality type. Participants included 32 university students who were neither musicians nor music majors. The Eysenck Personality Questionnaire (Eysenck & Eysenck, 1975) was used to identify participants as either extravert or introvert. Participants were randomly assigned to 1 of 4 types of musical tasks: listening, singing, rhythm tapping, or keyboard playing. Arousal level was measured using the Activation-Deactivation Adjective Check List (ADACL) (Thayer, 1978) before and after the musical task. The ADACL is a self-report scale consisting of a list of 20 adjectives which describe various transitory arousal states, including energy, tiredness, tension, and calmness. Results showed no significant difference between personality types and the changes in arousal level. Result indicated a significant effect of listening on decreased tension arousal. Singing and rhythm tapping, which are regarded as having a relatively moderate task difficulty, increased energy arousal significantly and decreased tiredness arousal significantly. Participants' tiredness arousal levels also decreased significantly after keyboard playing. These findings suggest that engaging in musical experience that has a moderate level of task difficulty makes individuals more energetic and less tired.

  15. Interoceptive Awareness Moderates the Relationship Between Perceived and Physiological Genital Arousal in Women.

    Science.gov (United States)

    Handy, Ariel B; Meston, Cindy M

    2016-12-01

    In general, laboratory studies have shown low correlations between subjective (ie, self-report) and physiologic (ie, vaginal pulse amplitude) measurements of sexual arousal in women. One explanation for this presumed low concordance is that women might not be attending to their genital responses and/or might be unable to accurately perceive their genital responses. To examine the extent to which women can perceive their genital arousal sensations, the role that interoceptive awareness plays in this ability, and whether interoceptive awareness influences sexual concordance in women. Twenty-six sexually functional women viewed an erotic film while their physiologic and perceived genital sexual arousal levels were measured continuously. Self-report measurements of sexual function and bodily awareness also were administered. Physiologic sexual arousal was measured with a vaginal photoplethysmograph, and perception of genital arousal was measured with an arousometer. Degree of bodily awareness was measured with the Multidimensional Assessment of Interoceptive Awareness questionnaire. Women exhibited a significant degree of agreement between physiologic and perceived genital arousal (P awareness was found to significantly moderate this relation (P awareness facilitated greater agreement between physiologic and perceived genital arousal. Interoceptive awareness also was found to facilitate greater concordance between subjective and physiologic sexual arousal (P awareness influences this ability and the relation between subjective and physiologic sexual arousal. Increasing bodily awareness could be a plausible route for treatment development. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  16. Disorders in sexual desire and sexual arousal in women, a 2010 state of the art.

    Science.gov (United States)

    Both, Stephanie; Laan, Ellen; Schultz, Willibrord Weijmar

    2010-12-01

    In this contribution, female sexual desire and arousal disorders are viewed from the perspective of incentive motivation and information processing models of sexual response. The effects of hormones, somatic disease, and medication on sexual arousability are discussed, as well as the influence of psychological factors, such as stimulus meaning, mood and cognition, and relational context on female sexual desire and arousal. Specific topics to attend to during the anamnesis of sexual desire and arousal problems, and empirically evaluated psychological and pharmacological treatments for these problems are discussed.

  17. Elevated arousal at time of decision-making is not the arbiter of risk avoidance in chickens.

    Science.gov (United States)

    Davies, A C; Radford, A N; Pettersson, I C; Yang, F P; Nicol, C J

    2015-02-03

    The somatic marker hypothesis proposes that humans recall previously experienced physiological responses to aid decision-making under uncertainty. However, little is known about the mechanisms used by non-human animals to integrate risk perception with predicted gains and losses. We monitored the behaviour and physiology of chickens when the choice between a high-gain (large food quantity), high-risk (1 in 4 probability of receiving an air-puff) option (HGRAP) or a low-gain (small food quantity), no-risk (of an air-puff) (LGNAP) option. We assessed when arousal increased by considering different stages of the decision-making process (baseline, viewing, anticipation, reward periods) and investigated whether autonomic responses influenced choice outcome both immediately and in the subsequent trial. Chickens were faster to choose and their heart-rate significantly increased between the viewing and anticipation (post-decision, pre-outcome) periods when selecting the HGRAP option. This suggests that they responded physiologically to the impending risk. Additionally, arousal was greater following a HGRAP choice that resulted in an air-puff, but this did not deter chickens from subsequently choosing HGRAP. In contrast to human studies, we did not find evidence that somatic markers were activated during the viewing period, suggesting that arousal is not a good measure of avoidance in non-human animals.

  18. The Experimental Study of Heat Pipe Exchanger for High Power LED Cooling System%热管换热器用于LED冷却系统的实验研究

    Institute of Scientific and Technical Information of China (English)

    勾昱君; 刘中良

    2012-01-01

    研发了一系列将发光二极管(LED)散热与热管传热相结合的用于大功率LED冷却的热管散热器,并对其传热性能进行了实验研究。结果表明,该系列热管散热器具有良好的散热能力,能将节点温度控制在70℃以下,满足了大功率LED对结点温度的控制要求;实验结果还表明,翅片结构不同,换热器散热能力明显不同,所研发系列异形翅片热管换热器的散热能力明显高于目前常用的普通矩形翅片热管换热器,其中以外翻形翅片热管换热器散热能力最好;还研究了热管换热器工作倾角对其散热能力的影响,并给出了热管排布数量、翅片材质及结构对换热器散热性能、换热装置体积、成本及质量的影响。%A new cooling concept for high power LED by combining the heat release of high power LED with two-phase heat transfer heat pipes was proposed,and in this study a series of heat pipes with specific fins structure were developed.From the experimental results obtained,it is found that the new heat pipe heat exchanger is of high heat dissipation capacity and compact construction that will meet the demand of high power LED cooling.The new heat pipe heat exchangers with different fin shapes have different efficiency of heat dissipation and the new heat exchanger with outwards-radiate fins has the best heat dissipation performance.It is also shown that the heat dissipation performance of the heat pipe heat exchanger changes with the position angle.The effects of the numbers of heat pipes and the fin materials on the heat dissipation performance of the whole cooling system were also carried out.

  19. New Processing of LED Phosphors

    OpenAIRE

    Toda, Kenji

    2012-01-01

    In order to synthesize LED phosphor materials, we have applied three novel synthesis techniques, “melt synthesis”, “fluidized bed synthesis” and “vapor-solid hybrid synthesis”, in contrast with the conventional solid state reaction technique. These synthesis techniques are also a general and powerful tool for rapid screening and improvements of new phosphor materials.

  20. Lu{sub 3}(Al,Si){sub 5}(O,N){sub 12}:Ce{sup 3+} phosphors with broad emission band and high thermal stability for white LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiaqing; Wang, Xiaojun; Xuan, Tongtong; Wang, Chunbo; Li, Huili, E-mail: hlli@phy.ecnu.edu.cn; Sun, Zhuo

    2015-02-15

    A yellow-orange emitting Lu{sub 3}Al{sub 5−x}Si{sub x}O{sub 12−x}N{sub x}:Ce{sup 3+} phosphor with excellent color rendering, high luminescent efficiency and high thermal stability was reported in this paper. It was synthesized by a conventional solid-state reaction method. The effect of Si{sup 4+}–N{sup 3−} incorporation on the optical properties of Lu{sub 3}Al{sub 5}O{sub 12}:Ce{sup 3+} phosphor was investigated and compared to YAG:Ce{sup 3+} with the same compositions. Similarly, the addition of α-Si{sub 3}N{sub 4} leads to a distinct redshift and broadening of photoluminescent spectrum, which is assigned to the increased covalency and crystal field strength caused by N{sup 3−}. Nevertheless, an excellent thermal stability and a higher integrated intensity presented by α-Si{sub 3}N{sub 4}-doped LuAG:Ce{sup 3+} are distinctive. Further, the emission intensity can be greatly enhanced by adding NaF flux. Finally, the white LED flat lamp with a CRI as high as 83 and a luminous efficiency of 85 lm/W is successfully realized by using a single LuAG-based oxynitride phosphor combined with a blue LED chip, which is completely feasible for general indoor illuminations to replace the traditional fluorescent or incandescent lamps. - Highlights: • Si{sub 3}N{sub 4}-doped LuAG:Ce{sup 3+} oxynitride phosphors were synthesized by a solid-state reaction. • The effect of Si{sup 4+}–N{sup 3−} incorporation on the optical properties was investigated. • The addition of Si{sub 3}N{sub 4} leads to an obvious redshift of the emission spectra. • Lu{sub 3}Al{sub 5−x}Si{sub x}O{sub 12−x}N{sub x}:Ce{sup 3+} shows an excellent thermal stability and a higher intensity. • A warm white LED with CRI=83 is achieved by a single oxynitride phosphor.

  1. LED lamp color control system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  2. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  3. Arousal responses in babies at risk of sudden infant death syndrome at different postnatal ages.

    LENUS (Irish Health Repository)

    Dunne, K P

    1992-03-01

    Hypercarbic and hypoxic arousal responses during sleep were measured in healthy term infants, infants where a previous sibling died from sudden infant death syndrome (SIDS) and infants suffering a clearly defined apparent life threatening event (ALTE) requiring vigorous or mouth to mouth resuscitation. Groups of infants were tested at approximately one, six and 13 weeks postnatally. Arousal was defined as gross body movement with eyes opening and moving or crying. Hypercarbic arousal was by step increases in F1 Co2 until arousal occurred or until endtidal (PETCO2) reached 8.7 KpA (65 mm Hg) Hypoxic arousal was by step decreases in FIO2 until arousal occurred or until an FIO2 of 0.15 had been maintained for 20 minutes. There was no difference in hypercaribic arousal threshold with age in any group. Hypercarbic arousal threshold was significantly higher in siblings (mean 53.4, 53.6, 54.7 mmHg. [7.12, 7.14, 7.29 KPA] at 0, 6, 13 postnatal weeks) compared to controls (mean 50.9, 52.3, 53.0mm Hg. [6.78, 6.97, 7.29 KPS respectively). ALTE infants differed only at 12 weeks having a significantly lower threshold (51.0mmHg. [6.80 KPA] V 53.0mm Hg. (7.06 KPA]) compared to controls. There was no difference in hypoxic arousal response with age in any group. An arousal response to hypoxia occurred in only 22% of ALTE infants and 40% of siblings compared to 67% of normal infants. Deficient sleep arousal, especially to hypoxia, is common in infants and especially those considered at increased risk from SIDS. This deficiency is present in the first postnatal week and did not vary overy the first three months of postnatal life.

  4. Arousal vs. relaxation: a comparison of the neurophysiological and cognitive correlates of Vajrayana and Theravada meditative practices.

    Directory of Open Access Journals (Sweden)

    Ido Amihai

    Full Text Available Based on evidence of parasympathetic activation, early studies defined meditation as a relaxation response. Later research attempted to categorize meditation as either involving focused or distributed attentional systems. Neither of these hypotheses received strong empirical support, and most of the studies investigated Theravada style meditative practices. In this study, we compared neurophysiological (EEG, EKG and cognitive correlates of meditative practices that are thought to utilize either focused or distributed attention, from both Theravada and Vajrayana traditions. The results of Study 1 show that both focused (Shamatha and distributed (Vipassana attention meditations of the Theravada tradition produced enhanced parasympathetic activation indicative of a relaxation response. In contrast, both focused (Deity and distributed (Rig-pa meditations of the Vajrayana tradition produced sympathetic activation, indicative of arousal. Additionally, the results of Study 2 demonstrated an immediate dramatic increase in performance on cognitive tasks following only Vajrayana styles of meditation, indicating enhanced phasic alertness due to arousal. Furthermore, our EEG results showed qualitatively different patterns of activation between Theravada and Vajrayana meditations, albeit highly similar activity between meditations within the same tradition. In conclusion, consistent with Tibetan scriptures that described Shamatha and Vipassana techniques as those that calm and relax the mind, and Vajrayana techniques as those that require 'an awake quality' of the mind, we show that Theravada and Vajrayana meditations are based on different neurophysiological mechanisms, which give rise to either a relaxation or arousal response. Hence, it may be more appropriate to categorize meditations in terms of relaxation vs. arousal, whereas classification methods that rely on the focused vs. distributed attention dichotomy may need to be reexamined.

  5. Dynamic modulation of amygdala-hippocampal connectivity by emotional arousal.

    Science.gov (United States)

    Fastenrath, Matthias; Coynel, David; Spalek, Klara; Milnik, Annette; Gschwind, Leo; Roozendaal, Benno; Papassotiropoulos, Andreas; de Quervain, Dominique J F

    2014-10-15

    Positive and negative emotional events are better remembered than neutral events. Studies in animals suggest that this phenomenon depends on the influence of the amygdala upon the hippocampus. In humans, however, it is largely unknown how these two brain structures functionally interact and whether these interactions are similar between positive and negative information. Using dynamic causal modeling of fMRI data in 586 healthy subjects, we show that the strength of the connection from the amygdala to the hippocampus was rapidly and robustly increased during the encoding of both positive and negative pictures in relation to neutral pictures. We also observed an increase in connection strength from the hippocampus to the amygdala, albeit at a smaller scale. These findings indicate that, during encoding, emotionally arousing information leads to a robust increase in effective connectivity from the amygdala to the hippocampus, regardless of its valence.

  6. Music and Emotion: the Dispositional or Arousal theory

    Directory of Open Access Journals (Sweden)

    Alessandra Buccella

    2012-05-01

    Full Text Available One of the ways of analysing the relationship between music and emotions in through musical expressiveness.As the theory I discuss in this paper puts it, expressiveness in a particular kind of music's secondary quality or, to use the term which gives the theory its name, a disposition of music to arouse a certain emotional response in listeners.The most accurate version of the dispositional theory is provided by Derek Matravers in his book Art and Emotion and in other papers: what I will try to do, then, is to illustrate Matravers theory and claim that it is a good solution to many problems concerning music and its capacity to affect our inner states.

  7. Emotion Processing for Arousal and Neutral Content in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Corina Satler

    2009-01-01

    Full Text Available Objective. To assess the ability of Alzheimer's disease (AD patients to perceive emotional information and to assign subjective emotional rating scores to audiovisual presentations. Materials and Methods. 24 subjects (14 with AD, matched to controls for age and educational levels were studied. After neuropsychological assessment, they watched a Neutral story and then a story with Emotional content. Results. Recall scores for both stories were significantly lower in AD (Neutral and Emotional: P=.001. CG assigned different emotional scores for each version of the test, P=.001, while ratings of AD did not differ, P=.32. Linear regression analyses determined the best predictors of emotional rating and recognition memory for each group among neuropsychological tests battery. Conclusions. AD patients show changes in emotional processing on declarative memory and a preserved ability to express emotions in face of arousal content. The present findings suggest that these impairments are due to general cognitive decline.

  8. Sleep, anesthesiology, and the neurobiology of arousal state control.

    Science.gov (United States)

    Lydic, Ralph; Baghdoyan, Helen A

    2005-12-01

    Sleep, like breathing, is a biologic rhythm that is actively generated by the brain. Neuronal networks that have evolved to regulate naturally occurring sleep preferentially modulate traits that define states of sedation and anesthesia. Sleep is temporally organized into distinct stages that are characterized by a unique constellation of physiologic and behavioral traits. Sleep and anesthetic susceptibility are genetically modulated, heritable phenotypes. This review considers 40 yr of research regarding the cellular and molecular mechanisms contributing to arousal state control. Clinical and preclinical data have debunked and supplanted the primitive view that sleep need is a weakness. Sleep deprivation and restriction diminish vigilance, alter neuroendocrine control, and negatively impact immune function. There is overwhelming support for the view that decrements in vigilance can negatively impact performance. Advances in neuroscience provide a foundation for the sea change in public and legal perspectives that now regard a sleep-deprived individual as impaired.

  9. Chronic burnout, somatic arousal and elevated salivary cortisol levels.

    Science.gov (United States)

    Melamed, S; Ugarten, U; Shirom, A; Kahana, L; Lerman, Y; Froom, P

    1999-06-01

    Burnout syndrome, comprised of the symptoms of emotional exhaustion, physical fatigue, and cognitive weariness, is believed to be a result of ineffective coping with enduring stress. This study of 111 nonshift blue-collar workers free of cardiovascular disease (CVD) examined whether chronic burnout is associated with a state of somatic and physiological hyperarousal. Results showed that 37 workers exhibited symptoms of chronic burnout, with symptoms lasting at least 6 months. These workers, compared to those with no burnout symptoms (n = 52) or nonchronic burnout symptoms (n = 22), had higher levels of tension at work, postwork irritability, more sleep disturbances and complaints of waking up exhausted, and higher cortisol levels during the work day. These results suggest that chronic burnout is associated with heightened somatic arousal and elevated salivary cortisol levels. This may be part of the mechanism underlying the emerging association between burnout and risk of CVD.

  10. Extraversion, arousal, and speed of retrieval from secondary storage.

    Science.gov (United States)

    Eysenck, M W

    1975-09-01

    Fifty-two subjects were assigned to one of four groups on the basis of scores on the Extraversion scale of the Eysenck Personality Inventory and on the General Activation scale of the Activation-Deactivation Adjective Check List. The subjects learned two lists composed of categorically related groups of words, with the number of categories and the number of words per category varied. Memory was probed by simultaneously presenting the subject with a category name and an item-position cue, and recording the recall latency. The major finding was that activation and extraversion interactively determined the recall latency for both category and item recall. The results were considered in light of arousal theory.

  11. The Mozart effect: evidence for the arousal hypothesis.

    Science.gov (United States)

    Roth, Edward A; Smith, Kenneth H

    2008-10-01

    This study investigated the effect of music listening for performance on a 25-question portion of the analytical section of the Graduate Record Exam by 72 undergraduate students (M age 21.9 yr.). Five levels of an auditory condition were based on Mozart Piano Sonata No. 3 (K. 281), Movement I (Allegro); a rhythm excerpt; a melody excerpt; traffic sounds; and silence. Participants were randomly assigned to one of the stimuli. After a 5-min., 43-sec. (length of the first Allegro movement) listening period, participants answered the questions. Analysis indicated participants achieved significantly higher mean scores after all auditory conditions than those in the silent condition. No statistically significant pairwise mean difference appeared between scores for the auditory conditions. Findings were interpreted in terms of an arousal framework, suggesting the higher means in all auditory conditions may reflect immediate exposure to auditory stimuli.

  12. Flashing LEDs for Microalgal Production.

    Science.gov (United States)

    Schulze, Peter S C; Guerra, Rui; Pereira, Hugo; Schüler, Lisa M; Varela, João C S

    2017-08-30

    Flashing lights are next-generation tools to mitigate light attenuation and increase the photosynthetic efficiency of microalgal cultivation systems illuminated by light-emitting diodes (LEDs). Optimal flashing light conditions depend on the reaction kinetics and properties of the linear electron transfer chain, energy dissipation, and storage mechanisms of a phototroph. In particular, extremely short and intense light flashes potentially mitigate light attenuation in photobioreactors without impairing photosynthesis. Intelligently controlling flashing light units and selecting electronic components can maximize light emission and energy efficiency. We discuss the biological, physical, and technical properties of flashing lights for algal production. We combine recent findings about photosynthetic pathways, self-shading in photobioreactors, and developments in solid-state technology towards the biotechnological application of LEDs to microalgal production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Radiometry of flashing LED sources

    Science.gov (United States)

    Gregory, Don A.; Medley, Stephanie; Roberts, Adam

    2008-08-01

    A laboratory based technique has been devised for measuring the illumination characteristics of flashing light emitting diode (LED) sources. The difference between the photopic measurement of a continuous source and a flashing source is that some analytic method must be incorporated into the measurement to account for the response of the eye. Ohno et al have devised an analytic expression for the impulse response of the eye, which closely matches existing forms used for finding effective intensity1. These other forms are the Blondel-Rey equation, the Form Factor method, and the Allard method.4,5,6 Ohno's research suggests a modified Allard method, but offers no procedure for actually making the measurement. In this research, the modified Allard1 method approach has been updated using standard laboratory equipment such as a silicon detector in conjunction with a digital multi-meter and Labview® software to make this measurement. Labview® allows exact computation of the modified Allard method. However, an approximation scheme for the conversion from radiometric units to photopic units must be adopted. The LED spectral form is approximately a Gaussian line shape with full width at half maximum of about 15 to 30nm. The Gaussian curve makes converting from radiometric to photopic units difficult. To simplify, the technique presented here estimates the spectral form of the LEDs to be a Dirac delta function situated at the peak wavelength. This allows the conversion from watts to lumens to be a simple application of the luminous efficiency curve.2 For LEDs with a full width half maximum of 20nm, this scheme is found to be accurate to +/- 5%.

  14. Simulation of Carbon Nanotube-based Heat Dissipation of High Power LED Lamp%碳纳米管在大功率LED灯具中的散热模拟

    Institute of Scientific and Technical Information of China (English)

    黄海波; 王元樟; 李爱玉; 程再军; 刘正达

    2016-01-01

    A finite element simulation of carbon nanotubes function in high power LED thermal management was conducted using FloEFD software in order to find out how carbon nanotube functions in heat dissipation of high power electronic devices. A simplified heat conduction model of multi⁃walled carbon nanotube arrays was established, and effective thermal conductivity of the multi⁃walled carbon nanotube array calculated based on the model. The steady⁃state temperature distributions of the LED with different thermal interface materials were then compared. It is shown that carbon nanotube arrays can greatly improve the thermal management performance of lamps, and that carbon nanotube polyurethane composite coating can greatly reduce the junction temperature.%用基于有限元方法的FloEFD软件,对碳纳米管在大功率发光二极管( LED)热管理中的应用进行模拟。建立起一个多壁碳纳米管阵列热传导的简化模型,据此模型对多壁碳纳米管阵列的等效热导率进行了计算。通过对采用不同热界面材料后LED灯具的稳态温度场分布的比较,发现碳纳米管阵列能大大提高灯具的热管理性能。模拟结果显示,采用聚氨酯碳纳米管复合材料涂层能大大降低结温。

  15. The Solar Energy Road Lamp Using High Brightness LED Based on the Maximum Power Point Tracking%基于最大功率点跟踪策略的LED太阳能路灯照明系统

    Institute of Scientific and Technical Information of China (English)

    汪勇; 张金明

    2013-01-01

    On the basis of the research for the model of solar batteries'circuit, and in views of shortcomings that the diode prevents current backflow which makes the output power of the system decrease in the solar energy road lamp system , a mixed analog-digital maximum power point tracking(MPPT)strategy is proposed in this paper.And according to the requirements of such strategy and solid-state light source LED driver circuit, a high brightness LED solar street lighting system is designed .Exoperiments show that such sys-tem has a stable, reliable and excellent performance .Moreover, the utilization of solar energy is increased about 20%.The system has high practical value.%  在太阳能电池电路模型的基础上,针对传统太阳能路灯系统中防电流倒灌二极管使系统输出功率下降的问题,提出了一种数模混合型最大功率点跟踪(MPPT)策略,并根据该策略和固态光源LED驱动电路的要求,设计了一个高亮度LED太阳能路灯照明系统。实验结果表明,该系统工作稳定可靠,性能优良,可提高太阳能利用率20%左右,具有较高的实用价值。

  16. LED structure with enhanced mirror reflectivity

    Science.gov (United States)

    Bergmann, Michael; Donofrio, Matthew; Heikman, Sten; Schneider, Kevin S; Haberern, Kevin W; Edmond, John A

    2014-04-01

    Embodiments of the present invention are generally related to LED chips having improved overall emission by reducing the light-absorbing effects of barrier layers adjacent mirror contacts. In one embodiment, a LED chip comprises one or more LEDs, with each LED having an active region, a first contact under the active region having a highly reflective mirror, and a barrier layer adjacent the mirror. The barrier layer is smaller than the mirror such that it does not extend beyond the periphery of the mirror. In another possible embodiment, an insulator is further provided, with the insulator adjacent the barrier layer and adjacent portions of the mirror not contacted by the active region or by the barrier layer. In yet another embodiment, a second contact is provided on the active region. In a further embodiment, the barrier layer is smaller than the mirror such that the periphery of the mirror is at least 40% free of the barrier layer, and the second contact is below the first contact and accessible from the bottom of the chip.

  17. Warming up for sleep? - ground squirrels sleep during arousals from hibernation

    NARCIS (Netherlands)

    Daan, Serge; Barnes, Brian M.; Strijkstra, Arjen M.

    1991-01-01

    Hypothermia during mammalian hibernation is periodically interrupted by arousals to euthermy, the function of which is unknown. We report that arctic ground squirrels (Spermophilus parryii) consistently sleep during these arousals, and that their EEG shows the decrease in slow wave activity (δ power

  18. WARMING UP FOR SLEEP - GROUND-SQUIRRELS SLEEP DURING AROUSALS FROM HIBERNATION

    NARCIS (Netherlands)

    DAAN, S; BARNES, BM; STRIJKSTRA, AM

    1991-01-01

    Hypothermia during mammalian hibernation is periodically interrupted by arousals to euthermy, the function of which is unknown. We report that arctic ground squirrels (Spermophilus parryii) consistently sleep during these arousals, and that their EEG shows the decrease in slow wave activity (delta-p

  19. Sleep respiratory disturbances and arousals at moderate altitude have overlapping electroencephalogram spectral signatures.

    Science.gov (United States)

    Stadelmann, Katrin; Latshang, Tsogyal D; Tarokh, Leila; Lo Cascio, Christian M; Tesler, Noemi; Stoewhas, Anne-Christin; Kohler, Malcolm; Bloch, Konrad E; Huber, Reto; Achermann, Peter

    2014-08-01

    An ascent to altitude has been shown to result in more central apneas and a shift towards lighter sleep in healthy individuals. This study employs spectral analysis to investigate the impact of respiratory disturbances (central/obstructive apnea and hypopnea or periodic breathing) at moderate altitude on the sleep electroencephalogram (EEG) and to compare EEG changes resulting from respiratory disturbances and arousals. Data were collected from 51 healthy male subjects who spent 1 night at moderate altitude (2590 m). Power density spectra of Stage 2 sleep were calculated in a subset (20) of these participants with sufficient artefact-free data for (a) epochs with respiratory events without an accompanying arousal, (b) epochs containing an arousal and (c) epochs of undisturbed Stage 2 sleep containing neither arousal nor respiratory events. Both arousals and respiratory disturbances resulted in reduced power in the delta, theta and spindle frequency range and increased beta power compared to undisturbed sleep. The similarity of the EEG changes resulting from altitude-induced respiratory disturbances and arousals indicates that central apneas are associated with micro-arousals, not apparent by visual inspection of the EEG. Our findings may have implications for sleep in patients and mountain tourists with central apneas and suggest that respiratory disturbances not accompanied by an arousal may, none the less, impact sleep quality and impair recuperative processes associated with sleep more than previously believed.

  20. Physiological and subjective sexual arousal in self-identified asexual women.

    Science.gov (United States)

    Brotto, Lori A; Yule, Morag A

    2011-08-01

    Asexuality can be defined as a lifelong lack of sexual attraction. Empirical research on asexuality reveals significantly lower self-reported sexual desire and arousal and lower rates of sexual activity; however, the speculation that there may also be an impaired psychophysiological sexual arousal response has never been tested. The aim of this study was to compare genital (vaginal pulse amplitude; VPA) and subjective sexual arousal in asexual and non-asexual women. Thirty-eight women between the ages of 19 and 55 years (10 heterosexual, 10 bisexual, 11 homosexual, and 7 asexual) viewed neutral and erotic audiovisual stimuli while VPA and self-reported sexual arousal and affect were measured. There were no significant group differences in the increased VPA and self-reported sexual arousal response to the erotic film between the groups. Asexuals showed significantly less positive affect, sensuality-sexual attraction, and self-reported autonomic arousal to the erotic film compared to the other groups; however, there were no group differences in negative affect or anxiety. Genital-subjective sexual arousal concordance was significantly positive for the asexual women and non-significant for the other three groups, suggesting higher levels of interoceptive awareness among asexuals. Taken together, the findings suggest normal subjective and physiological sexual arousal capacity in asexual women and challenge the view that asexuality should be characterized as a sexual dysfunction.