Highly efficient silicon light emitting diode

NARCIS (Netherlands)

Le Minh, P.; Holleman, J.; Wallinga, Hans

2002-01-01

In this paper, we describe the fabrication, using standard silicon processing techniques, of silicon light-emitting diodes (LED) that efficiently emit photons with energy around the silicon bandgap. The improved efficiency had been explained by the spatial confinement of charge carriers due to a

Simple single-emitting layer hybrid white organic light emitting with high color stability

Science.gov (United States)

Nguyen, C.; Lu, Z. H.

2017-10-01

Simultaneously achieving a high efficiency and color quality at luminance levels required for solid-state lighting has been difficult for white organic light emitting diodes (OLEDs). Single-emitting layer (SEL) white OLEDs, in particular, exhibit a significant tradeoff between efficiency and color stability. Furthermore, despite the simplicity of SEL white OLEDs being its main advantage, the reported device structures are often complicated by the use of multiple blocking layers. In this paper, we report a highly simplified three-layered white OLED that achieves a low turn-on voltage of 2.7 V, an external quantum efficiency of 18.9% and power efficiency of 30 lm/W at 1000 cd/cm2. This simple white OLED also shows good color quality with a color rendering index of 75, CIE coordinates (0.42, 0.46), and little color shifting at high luminance. The device consists of a SEL sandwiched between a hole transport layer and an electron transport layer. The SEL comprises a thermally activated delayer fluorescent molecule having dual functions as a blue emitter and as a host for other lower energy emitters. The improved color stability and efficiency in such a simple device structure is explained as due to the elimination of significant energy barriers at various organic-organic interfaces in the traditional devices having multiple blocking layers.

Characterization of metal and trace element contents of particulate matter (PM10) emitted by vehicles running on Brazilian fuels-hydrated ethanol and gasoline with 22% of anhydrous ethanol.

Science.gov (United States)

Ferreira da Silva, Moacir; Vicente de Assunção, João; de Fátima Andrade, Maria; Pesquero, Célia R

2010-01-01

Emission of fine particles by mobile sources has been a matter of great concern due to its potential risk both to human health and the environment. Although there is no evidence that one sole component may be responsible for the adverse health outcomes, it is postulated that the metal particle content is one of the most important factors, mainly in relation to oxidative stress. Data concerning the amount and type of metal particles emitted by automotive vehicles using Brazilian fuels are limited. The aim of this study was to identify inhalable particles (PM(10)) and their trace metal content in two light-duty vehicles where one was fueled with ethanol while the other was fueled with gasoline mixed with 22% of anhydrous ethanol (gasohol); these engines were tested on a chassis dynamometer. The elementary composition of the samples was evaluated by the particle-induced x-ray emission technique. The experiment showed that total emission factors ranged from 2.5 to 11.8 mg/km in the gasohol vehicle, and from 1.2 to 3 mg/km in the ethanol vehicle. The majority of particles emitted were in the fine fraction (PM(2.5)), in which Al, Si, Ca, and Fe corresponded to 80% of the total weight. PM(10) emissions from the ethanol vehicle were about threefold lower than those of gasohol. The elevated amount of fine particulate matter is an aggravating factor, considering that these particles, and consequently associated metals, readily penetrate deeply into the respiratory tract, producing damage to lungs and other tissues.

Remote sensing of on-road vehicle emissions: Mechanism, applications and a case study from Hong Kong

Science.gov (United States)

Huang, Yuhan; Organ, Bruce; Zhou, John L.; Surawski, Nic C.; Hong, Guang; Chan, Edward F. C.; Yam, Yat Shing

2018-06-01

Vehicle emissions are a major contributor to air pollution in cities and have serious health impacts to their inhabitants. On-road remote sensing is an effective and economic tool to monitor and control vehicle emissions. In this review, the mechanism, accuracy, advantages and limitations of remote sensing were introduced. Then the applications and major findings of remote sensing were critically reviewed. It was revealed that the emission distribution of on-road vehicles was highly skewed so that the dirtiest 10% vehicles accounted for over half of the total fleet emissions. Such findings highlighted the importance and effectiveness of using remote sensing for in situ identification of high-emitting vehicles for further inspection and maintenance programs. However, the accuracy and number of vehicles affected by screening programs were greatly dependent on the screening criteria. Remote sensing studies showed that the emissions of gasoline and diesel vehicles were significantly reduced in recent years, with the exception of NOx emissions of diesel vehicles in spite of greatly tightened automotive emission regulations. Thirdly, the experience and issues of using remote sensing for identifying high-emitting vehicles in Hong Kong (where remote sensing is a legislative instrument for enforcement purposes) were reported. That was followed by the first time ever identification and discussion of the issue of frequent false detection of diesel high-emitters using remote sensing. Finally, the challenges and future research directions of on-road remote sensing were elaborated.

Auger Emitting Radiopharmaceuticals for Cancer Therapy

Science.gov (United States)

Falzone, Nadia; Cornelissen, Bart; Vallis, Katherine A.

Radionuclides that emit Auger electrons have been of particular interest as therapeutic agents. This is primarily due to the short range in tissue, controlled linear paths and high linear energy transfer of these particles. Taking into consideration that ionizations are clustered within several cubic nanometers around the point of decay the possibility of incorporating an Auger emitter in close proximity to the cancer cell DNA has immense therapeutic potential thus making nuclear targeted Auger-electron emitters ideal for precise targeting of cancer cells. Furthermore, many Auger-electron emitters also emit γ-radiation, this property makes Auger emitting radionuclides a very attractive option as therapeutic and diagnostic agents in the molecular imaging and management of tumors. The first requirement for the delivery of Auger emitting nuclides is the definition of suitable tumor-selective delivery vehicles to avoid normal tissue toxicity. One of the main challenges of targeted radionuclide therapy remains in matching the physical and chemical characteristics of the radionuclide and targeting moiety with the clinical character of the tumor. Molecules and molecular targets that have been used in the past can be classified according to the carrier molecule used to deliver the Auger-electron-emitting radionuclide. These include (1) antibodies, (2) peptides, (3) small molecules, (4) oligonucleotides and peptide nucleic acids (PNAs), (5) proteins, and (6) nanoparticles. The efficacy of targeted radionuclide therapy depends greatly on the ability to increase intranuclear incorporation of the radiopharmaceutical without compromising toxicity. Several strategies to achieve this goal have been proposed in literature. The possibility of transferring tumor therapy based on the emission of Auger electrons from experimental models to patients has vast therapeutic potential, and remains a field of intense research.

High Intensity Organic Light-emitting Diodes

Science.gov (United States)

Qi, Xiangfei

This thesis is dedicated to the fabrication, modeling, and characterization to achieve high efficiency organic light-emitting diodes (OLEDs) for illumination applications. Compared to conventional lighting sources, OLEDs enabled the direct conversion of electrical energy into light emission and have intrigued the world's lighting designers with the long-lasting, highly efficient illumination. We begin with a brief overview of organic technology, from basic organic semiconductor physics, to its application in optoelectronics, i.e. light-emitting diodes, photovoltaics, photodetectors and thin-film transistors. Due to the importance of phosphorescent materials, we will focus on the photophysics of metal complexes that is central to high efficiency OLED technology, followed by a transient study to examine the radiative decay dynamics in a series of phosphorescent platinum binuclear complexes. The major theme of this thesis is the design and optimization of a novel architecture where individual red, green and blue phosphorescent OLEDs are vertically stacked and electrically interconnected by the compound charge generation layers. We modeled carrier generation from the metal-oxide/doped organic interface based on a thermally assisted tunneling mechanism. The model provides insights to the optimization of a stacked OLED from both electrical and optical point of view. To realize the high intensity white lighting source, the efficient removal of heat is of a particular concern, especially in large-area devices. A fundamental transfer matrix analysis is introduced to predict the thermal properties in the devices. The analysis employs Laplace transforms to determine the response of the system to the combined effects of conduction, convection, and radiation. This perspective of constructing transmission matrices greatly facilitates the calculation of transient coupled heat transfer in a general multi-layer composite. It converts differential equations to algebraic forms, and

Highly efficient greenish-blue platinum-based phosphorescent organic light-emitting diodes on a high triplet energy platform

Energy Technology Data Exchange (ETDEWEB)

Chang, Y. L., E-mail: yilu.chang@mail.utoronto.ca; Gong, S., E-mail: sgong@chem.utoronto.ca; White, R.; Lu, Z. H., E-mail: zhenghong.lu@utoronto.ca [Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, Ontario M5S 3E4 (Canada); Wang, X.; Wang, S., E-mail: wangs@chem.queensu.ca [Department of Chemistry, Queen' s University, 90 Bader Lane, Kingston, Ontario K7L 3N6 (Canada); Yang, C. [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

2014-04-28

We have demonstrated high-efficiency greenish-blue phosphorescent organic light-emitting diodes (PHOLEDs) based on a dimesitylboryl-functionalized C^N chelate Pt(II) phosphor, Pt(m-Bptrz)(t-Bu-pytrz-Me). Using a high triplet energy platform and optimized double emissive zone device architecture results in greenish-blue PHOLEDs that exhibit an external quantum efficiency of 24.0% and a power efficiency of 55.8 lm/W. This record high performance is comparable with that of the state-of-the-art Ir-based sky-blue organic light-emitting diodes.

On-board emission measurement of high-loaded light-duty vehicles in Algeria.

Science.gov (United States)

Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

2008-01-01

A sample of eight private gasoline and diesel conventional light-duty vehicles (LDVs) in use with various ages, carrying a load of 460 kg, were tested on a representative trip in the traffic flow of the city of Blida to obtain emission factors representing the actual use conditions of Algerian LDVs. The gas sampling system (mini-constant volume sampling) as well as the analyzers are carried on-board the vehicle. Around 55 tests were conducted during 3 months covering more than 480 km under various real driving conditions. The mean speed downtown is about 16.1 km/hr with a rather low acceleration, an average of 0.60 m/sec2. For each test, kinematics are recorded as well as the analysis of the four emitted pollutants carbon dioxide, carbon monoxide, oxides of nitrogen, and total hydrocarbons. Emission factors were evaluated according to speed for each category of gasoline and diesel engines. The influence of some parameters such as cold/hot start, age of vehicle and its state of maintenance are discussed. Results are compared with the European database ARTEMIS for comparable vehicles. These measurements contribute to the development of unit emission of the vehicles used in Algeria, which are necessary for the calculation of emission inventory of pollutants and greenhouse gases from the road transportation sector. The unit emissions constitute a tool of decisionmaking aid regarding the conception of new regulations of vehicle control and inspection in Algeria and even in similar developing countries.

Echolocating bats emit a highly directional sonar sound beam in the field

DEFF Research Database (Denmark)

Surlykke, Annemarie; Boel Pedersen, Simon; Jakobsen, Lasse

2009-01-01

Bats use echolocation or biosonar to navigate and find prey at night. They emit short ultrasonic calls and listen for reflected echoes. The beam width of the calls is central to the function of the sonar, but directionality of echolocation calls has never been measured from bats flying in the wild....... We used a microphone array to record sounds and determine horizontal directionality for echolocation calls of the trawling Daubenton's bat, Myotis daubentonii, flying over a pond in its natural habitat. Myotis daubentonii emitted highly directional calls in the field. Directionality increased...... and directionality can be explained by the simple piston model. The model also suggests that the increase in the emitted intensity in the field is caused by the increased directionality, focusing sound energy in the forward direction. The bat may increase directionality by opening the mouth wider to emit a louder...

Advanced Range Safety System for High Energy Vehicles

Science.gov (United States)

Claxton, Jeffrey S.; Linton, Donald F.

2002-01-01

The advanced range safety system project is a collaboration between the National Aeronautics and Space Administration and the United States Air Force to develop systems that would reduce costs and schedule for safety approval for new classes of unmanned high-energy vehicles. The mission-planning feature for this system would yield flight profiles that satisfy the mission requirements for the user while providing an increased quality of risk assessment, enhancing public safety. By improving the speed and accuracy of predicting risks to the public, mission planners would be able to expand flight envelopes significantly. Once in place, this system is expected to offer the flexibility of handling real-time risk management for the high-energy capabilities of hypersonic vehicles including autonomous return-from-orbit vehicles and extended flight profiles over land. Users of this system would include mission planners of Space Launch Initiative vehicles, space planes, and other high-energy vehicles. The real-time features of the system could make extended flight of a malfunctioning vehicle possible, in lieu of an immediate terminate decision. With this improved capability, the user would have more time for anomaly resolution and potential recovery of a malfunctioning vehicle.

Variations in speciated emissions from spark-ignition and compression-ignition motor vehicles in California's south coast air basin.

Science.gov (United States)

Fujita, Eric M; Zielinska, Barbara; Campbell, David E; Arnott, W Patrick; Sagebiel, John C; Mazzoleni, Lynn; Chow, Judith C; Gabele, Peter A; Crews, William; Snow, Richard; Clark, Nigel N; Wayne, W Scott; Lawson, Douglas R

2007-06-01

The U.S. Department of Energy Gasoline/Diesel PM Split Study examined the sources of uncertainties in using an organic compound-based chemical mass balance receptor model to quantify the contributions of spark-ignition (SI) and compression-ignition (CI) engine exhaust to ambient fine particulate matter (PM2.5). This paper presents the chemical composition profiles of SI and CI engine exhaust from the vehicle-testing portion of the study. Chemical analysis of source samples consisted of gravimetric mass, elements, ions, organic carbon (OC), and elemental carbon (EC) by the Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciation Trends Network (STN) thermal/optical methods, polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, alkanes, and polar organic compounds. More than half of the mass of carbonaceous particles emitted by heavy-duty diesel trucks was EC (IMPROVE) and emissions from SI vehicles contained predominantly OC. Although total carbon (TC) by the IMPROVE and STN protocols agreed well for all of the samples, the STN/IMPROVE ratios for EC from SI exhaust decreased with decreasing sample loading. SI vehicles, whether low or high emitters, emitted greater amounts of high-molecular-weight particulate PAHs (benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and coronene) than did CI vehicles. Diesel emissions contained higher abundances of two- to four-ring semivolatile PAHs. Diacids were emitted by CI vehicles but are also prevalent in secondary organic aerosols, so they cannot be considered unique tracers. Hopanes and steranes were present in lubricating oil with similar composition for both gasoline and diesel vehicles and were negligible in gasoline or diesel fuels. CI vehicles emitted greater total amounts of hopanes and steranes on a mass per mile basis, but abundances were comparable to SI exhaust normalized to TC emissions within measurement uncertainty. The combustion-produced high-molecular-weight PAHs were found in used

Tactical Decision Aids High Bandwidth Links Using Autonomous Vehicles

Science.gov (United States)

2004-01-01

1 Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) A. J. Healey, D. P. Horner, Center for Autonomous Underwater Vehicle...SUBTITLE Tactical Decision Aids (High Bandwidth Links Using Autonomous Vehicles ) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

Demand for alternative-fuel vehicles when registration taxes are high

DEFF Research Database (Denmark)

Mabit, Stefan Lindhard; Fosgerau, Mogens

2011-01-01

This paper investigates the potential futures for alternative-fuel vehicles in Denmark, where the vehicle registration tax is very high and large tax rebates can be given. A large stated choice dataset has been collected concerning vehicle choice among conventional, hydrogen, hybrid, bio......-diesel, and electric vehicles. We estimate a mixed logit model that improves on previous contributions by controlling for reference dependence and allowing for correlation of random effects. Both improvements are found to be important. An application of the model shows that alternative-fuel vehicles with present...... technology could obtain fairly high market shares given tax regulations possible in the present high-tax vehicle market....

Extraction of surface plasmons in organic light-emitting diodes via high-index coupling.

Science.gov (United States)

Scholz, Bert J; Frischeisen, Jörg; Jaeger, Arndt; Setz, Daniel S; Reusch, Thilo C G; Brütting, Wolfgang

2012-03-12

The efficiency of organic light-emitting diodes (OLEDs) is still limited by poor light outcoupling. In particular, the excitation of surface plasmon polaritons (SPPs) at metal-organic interfaces represents a major loss channel. By combining optical simulations and experiments on simplified luminescent thin-film structures we elaborate the conditions for the extraction of SPPs via coupling to high-index media. As a proof-of-concept, we demonstrate the possibility to extract light from wave-guided modes and surface plasmons in a top-emitting white OLED by a high-index prism.

Batteries for electric road vehicles.

Science.gov (United States)

Goodenough, John B; Braga, M Helena

2018-01-15

The dependence of modern society on the energy stored in a fossil fuel is not sustainable. An immediate challenge is to eliminate the polluting gases emitted from the roads of the world by replacing road vehicles powered by the internal combustion engine with those powered by rechargeable batteries. These batteries must be safe and competitive in cost, performance, driving range between charges, and convenience. The competitive performance of an electric car has been demonstrated, but the cost of fabrication, management to ensure safety, and a short cycle life have prevented large-scale penetration of the all-electric road vehicle into the market. Low-cost, safe all-solid-state cells from which dendrite-free alkali-metal anodes can be plated are now available; they have an operating temperature range from -20 °C to 80 °C and they permit the design of novel high-capacity, high-voltage cathodes providing fast charge/discharge rates. Scale-up to large multicell batteries is feasible.

High-efficiency orange and tandem white organic light-emitting diodes using phosphorescent dyes with horizontally oriented emitting dipoles.

Science.gov (United States)

Lee, Sunghun; Shin, Hyun; Kim, Jang-Joo

2014-09-03

Tandem white organic light-emitting diodes (WOLEDs) using horizontally oriented phosphorescent dyes in an exciplex-forming co-host are presented, along with an orange OLED. A high external quantum efficiency of 32% is achieved for the orange OLED at 1000 cd m(-2) and the tandem WOLEDs exhibit a high maximum EQE of 54.3% (PE of 63 lm W(-1)). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Submonolayer Quantum Dots for High Speed Surface Emitting Lasers

Directory of Open Access Journals (Sweden)

Zakharov ND

2007-01-01

Full Text Available AbstractWe report on progress in growth and applications of submonolayer (SML quantum dots (QDs in high-speed vertical-cavity surface-emitting lasers (VCSELs. SML deposition enables controlled formation of high density QD arrays with good size and shape uniformity. Further increase in excitonic absorption and gain is possible with vertical stacking of SML QDs using ultrathin spacer layers. Vertically correlated, tilted or anticorrelated arrangements of the SML islands are realized and allow QD strain and wavefunction engineering. Respectively, both TE and TM polarizations of the luminescence can be achieved in the edge-emission using the same constituting materials. SML QDs provide ultrahigh modal gain, reduced temperature depletion and gain saturation effects when used in active media in laser diodes. Temperature robustness up to 100 °C for 0.98 μm range vertical-cavity surface-emitting lasers (VCSELs is realized in the continuous wave regime. An open eye 20 Gb/s operation with bit error rates better than 10−12has been achieved in a temperature range 25–85 °Cwithout current adjustment. Relaxation oscillations up to ∼30 GHz have been realized indicating feasibility of 40 Gb/s signal transmission.

Highly efficient single-layer dendrimer light-emitting diodes with balanced charge transport

Science.gov (United States)

Anthopoulos, Thomas D.; Markham, Jonathan P. J.; Namdas, Ebinazar B.; Samuel, Ifor D. W.; Lo, Shih-Chun; Burn, Paul L.

2003-06-01

High-efficiency single-layer-solution-processed green light-emitting diodes based on a phosphorescent dendrimer are demonstrated. A peak external quantum efficiency of 10.4% (35 cd/A) was measured for a first generation fac-tris(2-phenylpyridine) iridium cored dendrimer when blended with 4,4'-bis(N-carbazolyl)biphenyl and electron transporting 1,3,5-tris(2-N-phenylbenzimidazolyl)benzene at 8.1 V. A maximum power efficiency of 12.8 lm/W was measured also at 8.1 V and 550 cd/m2. These results indicate that, by simple blending of bipolar and electron-transporting molecules, highly efficient light-emitting diodes can be made employing a very simple device structure.

Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

Directory of Open Access Journals (Sweden)

Hsu Chih-Neng

2013-01-01

Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

A high capability teleoperated vehicle for hazardous applications

International Nuclear Information System (INIS)

Dudar, A.M.; Witherspoon, R.L.

1995-01-01

The Robotics Development Group at the Savannah River Site is developing a high performance teleoperated vehicle for use in radioactive and hazardous environments. The three-wheeled vehicle incorporates a highly dexterous 6 degree-of-freedom (DOF), hydraulically-powered manipulator made by Schilling Development, Inc. The teleoperator is called Little MoRT (MObile Radio-controlled Teleoperator) and is a modified version of a commercially available, battery-powered, warehouse vehicle. Little MoRT is controlled remotely by a universal robot controller either through a radio frequency link or a tethered cable. Six video cameras and a microphone provide the operator with audio-visual feedback of the vehicle and its surrounding environment. The vehicle also incorporates a hydraulic power unit consisting of a propane-driven engine for powering the Schilling manipulator. Little MoRT is capable of operating in outdoor as well as indoor environments and is well suited for decontamination and decommissioning activities such as dismantling, sorting, and surveying of radioactive waste

Benefits of high aerodynamic efficiency to orbital transfer vehicles

Science.gov (United States)

Andrews, D. G.; Norris, R. B.; Paris, S. W.

1984-01-01

The benefits and costs of high aerodynamic efficiency on aeroassisted orbital transfer vehicles (AOTV) are analyzed. Results show that a high lift to drag (L/D) AOTV can achieve significant velocity savings relative to low L/D aerobraked OTV's when traveling round trip between low Earth orbits (LEO) and alternate orbits as high as geosynchronous Earth orbit (GEO). Trajectory analysis is used to show the impact of thermal protection system technology and the importance of lift loading coefficient on vehicle performance. The possible improvements in AOTV subsystem technologies are assessed and their impact on vehicle inert weight and performance noted. Finally, the performance of high L/D AOTV concepts is compared with the performances of low L/D aeroassisted and all propulsive OTV concepts to assess the benefits of aerodynamic efficiency on this class of vehicle.

Highly efficient exciplex organic light-emitting diodes incorporating a heptazine derivative as an electron acceptor.

Science.gov (United States)

Li, Jie; Nomura, Hiroko; Miyazaki, Hiroshi; Adachi, Chihaya

2014-06-11

Highly efficient exciplex systems incorporating a heptazine derivative () as an electron acceptor and 1,3-di(9H-carbazol-9-yl)benzene () as an electron donor are developed. An organic light-emitting diode containing 8 wt% : as an emitting layer exhibits a maximum external quantum efficiency of 11.3%.

High temperature superconducting Maglev equipment on vehicle

Science.gov (United States)

Wang, S. Y.; Wang, J. S.; Ren, Z. Y.; Zhu, M.; Jiang, H.; Wang, X. R.; Shen, X. M.; Song, H. H.

2003-04-01

Onboard high temperature superconducting (HTS) Maglev equipment is a heart part of a HTS Maglev vehicle, which is composed of YBaCuO bulks and rectangle-shape liquid nitrogen vessel and used successfully in the first manned HTS Maglev test vehicle. Arrangement of YBaCuO bulks in liquid nitrogen vessel, structure of the vessel, levitation forces of a single vessel and two vessels, and total levitation force are reported. The first manned HTS Maglev test vehicle in the world has operated well more than one year after it was born on Dec. 31, 2000, and more than 23,000 passengers have taken the vehicle till now. Well operation of more than one year proves the reliability of the onboard HTS Maglev equipment.

Manufacturing polymer light emitting diode with high luminance efficiency by solution process

Science.gov (United States)

Kim, Miyoung; Jo, SongJin; Yang, Ho Chang; Yoon, Dang Mo; Kwon, Jae-Taek; Lee, Seung-Hyun; Choi, Ju Hwan; Lee, Bum-Joo; Shin, Jin-Koog

2012-06-01

While investigating polymer light emitting diodes (polymer-LEDs) fabricated by solution process, surface roughness influences electro-optical (E-O) characteristics. We expect that E-O characteristics such as luminance and power efficiency related to surface roughness and layer thickness of emitting layer with poly-9-Vinylcarbazole. In this study, we fabricated polymer organic light emitting diodes by solution process which guarantees easy, eco-friendly and low cost manufacturing for flexible display applications. In order to obtain high luminescence efficiency, E-O characteristics of these devices by varying parameters for printing process have been investigated. Therefore, we optimized process condition for polymer-LEDs by adjusting annealing temperatures of emission, thickness of emission layer showing efficiency (10.8 cd/A) at 10 mA/cm2. We also checked wavelength dependent electroluminescence spectrum in order to find the correlation between the variation of efficiency and the thickness of the layer.

Highly Efficient Spectrally Stable Red Perovskite Light-Emitting Diodes.

Science.gov (United States)

Tian, Yu; Zhou, Chenkun; Worku, Michael; Wang, Xi; Ling, Yichuan; Gao, Hanwei; Zhou, Yan; Miao, Yu; Guan, Jingjiao; Ma, Biwu

2018-05-01

Perovskite light-emitting diodes (LEDs) have recently attracted great research interest for their narrow emissions and solution processability. Remarkable progress has been achieved in green perovskite LEDs in recent years, but not blue or red ones. Here, highly efficient and spectrally stable red perovskite LEDs with quasi-2D perovskite/poly(ethylene oxide) (PEO) composite thin films as the light-emitting layer are reported. By controlling the molar ratios of organic salt (benzylammonium iodide) to inorganic salts (cesium iodide and lead iodide), luminescent quasi-2D perovskite thin films are obtained with tunable emission colors from red to deep red. The perovskite/polymer composite approach enables quasi-2D perovskite/PEO composite thin films to possess much higher photoluminescence quantum efficiencies and smoothness than their neat quasi-2D perovskite counterparts. Electrically driven LEDs with emissions peaked at 638, 664, 680, and 690 nm have been fabricated to exhibit high brightness and external quantum efficiencies (EQEs). For instance, the perovskite LED with an emission peaked at 680 nm exhibits a brightness of 1392 cd m -2 and an EQE of 6.23%. Moreover, exceptional electroluminescence spectral stability under continuous device operation has been achieved for these red perovskite LEDs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Color-tunable and high-efficiency organic light-emitting diode by adjusting exciton bilateral migration zone

Science.gov (United States)

Liu, Shengqiang; Wu, Ruofan; Huang, Jiang; Yu, Junsheng

2013-09-01

A voltage-controlled color-tunable and high-efficiency organic light-emitting diode (OLED) by inserting 16-nm N,N'-dicarbazolyl-3,5-benzene (mCP) interlayer between two complementary emitting layers (EMLs) was fabricated. The OLED emitted multicolor ranging from blue (77.4 cd/A @ 6 V), white (70.4 cd/A @ 7 V), to yellow (33.7 cd/A @ 9 V) with voltage variation. An equivalent model was proposed to reveal the color-tunable and high-efficiency emission of OLEDs, resulting from the swing of exciton bilateral migration zone near mCP/blue-EML interface. Also, the model was verified with a theoretical arithmetic using single-EML OLEDs to disclose the crucial role of mCP exciton adjusting layer.

Top emitting white OLEDs

Energy Technology Data Exchange (ETDEWEB)

Freitag, Patricia; Luessem, Bjoern; Leo, Karl [Technische Universitaet Dresden, Institut fuer Angewandte Photophysik, George-Baehr-Strasse 1, 01069 Dresden (Germany)

2009-07-01

Top emitting organic light emitting diodes (TOLEDs) provide a number of interesting opportunities for new applications, such as the opportunity to fabricate ITO-free devices by using opaque substrates. This makes it possible to manufacture low cost OLEDs for signage and lighting applications. A general top emitting device consists of highly reflecting metal contacts as anode and semitransparent cathode, the latter one for better outcouling reasons. In between several organic materials are deposited as charge transporting, blocking, and emission layers. Here, we show a top emitting white organic light emitting diode with silver electrodes arranged in a p-i-n structure with p- and n-doped charge transport layers. The centrical emission layer consists of two phosphorescent (red and green) and one fluorescent (blue) emitter systems separated by an ambipolar interlayer to avoid mutual exciton quenching. By adding an additional dielectric capping layer on top of the device stack, we achieve a reduction of the strong microcavity effects which appear due to the high reflection of both metal electrodes. Therefore, the outcoupled light shows broad and nearly angle-independent emission spectra, which is essential for white light emitting diodes.

Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung-Bum; Lee, Jeong-Hwan; Moon, Chang-Ki; Kim, Jang-Joo, E-mail: jjkim@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

2014-02-17

We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000 cd/m{sup 2} corresponding to a current efficiency of 110 cd/A, low efficiency roll-off with 21% at 10 000 cd/m{sup 2} and low turn on voltage of 2.4 V. Especially, the device showed very small color change with the variation of Δx = 0.02, Δy = 0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.

High mobility solution-processed hybrid light emitting transistors

International Nuclear Information System (INIS)

Walker, Bright; Kim, Jin Young; Ullah, Mujeeb; Burn, Paul L.; Namdas, Ebinazar B.; Chae, Gil Jo; Cho, Shinuk; Seo, Jung Hwa

2014-01-01

We report the design, fabrication, and characterization of high-performance, solution-processed hybrid (inorganic-organic) light emitting transistors (HLETs). The devices employ a high-mobility, solution-processed cadmium sulfide layer as the switching and transport layer, with a conjugated polymer Super Yellow as an emissive material in non-planar source/drain transistor geometry. We demonstrate HLETs with electron mobilities of up to 19.5 cm 2 /V s, current on/off ratios of >10 7 , and external quantum efficiency of 10 −2 % at 2100 cd/m 2 . These combined optical and electrical performance exceed those reported to date for HLETs. Furthermore, we provide full analysis of charge injection, charge transport, and recombination mechanism of the HLETs. The high brightness coupled with a high on/off ratio and low-cost solution processing makes this type of hybrid device attractive from a manufacturing perspective

Top-emitting organic light-emitting diodes.

Science.gov (United States)

Hofmann, Simone; Thomschke, Michael; Lüssem, Björn; Leo, Karl

2011-11-07

We review top-emitting organic light-emitting diodes (OLEDs), which are beneficial for lighting and display applications, where non-transparent substrates are used. The optical effects of the microcavity structure as well as the loss mechanisms are discussed. Outcoupling techniques and the work on white top-emitting OLEDs are summarized. We discuss the power dissipation spectra for a monochrome and a white top-emitting OLED and give quantitative reports on the loss channels. Furthermore, the development of inverted top-emitting OLEDs is described.

A PEMS study of the emissions of gaseous pollutants and ultrafine particles from gasoline- and diesel-fueled vehicles

Science.gov (United States)

Huang, Cheng; Lou, Diming; Hu, Zhiyuan; Feng, Qian; Chen, Yiran; Chen, Changhong; Tan, Piqiang; Yao, Di

2013-10-01

On-road emission measurements of gasoline- and diesel-fueled vehicles were conducted by a portable emission measurement system (PEMS) in Shanghai, China. Horiba OBS 2200 and TSI EEPS 3090 were employed to detect gaseous and ultrafine particle emissions during the tests. The driving-based emission factors of gaseous pollutants and particle mass and number were obtained on various road types. The average NOx emission factors of the diesel bus, diesel car, and gasoline car were 8.86, 0.68, and 0.17 g km-1, all of which were in excess of their emission limits. The particle number emission factors were 7.06 × 1014, 6.08 × 1014, and 1.57 × 1014 km-1, generally higher than the results for similar vehicle types reported in the previous studies. The size distributions of the particles emitted from the diesel vehicles were mainly concentrated in the accumulation mode, while those emitted from the gasoline car were mainly distributed in the nucleation mode. Both gaseous and particle emission rates exhibit significant correlations with the change in vehicle speed and power demand. The lowest emission rates for each vehicle type were produced during idling. The highest emission rates for each vehicle type were generally found in high-VSP bins. The particle number emission rates of the gasoline car show the strongest growth trend with increasing VSP and speed. The particle number emission for the gasoline car increased by 3 orders of magnitude from idling to the highest VSP and driving speed conditions. High engine power caused by aggressive driving or heavy loads is the main contributor to high emissions for these vehicles in real-world situations.

Effects of High Octane Ethanol Blends on Four Legacy Flex-Fuel Vehicles, and a Turbocharged GDI Vehicle

Energy Technology Data Exchange (ETDEWEB)

Thomas, John F [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Brian H [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huff, Shean P [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-03-01

The U.S. Department of Energy (DOE) is supporting engine and vehicle research to investigate the potential of high-octane fuels to improve fuel economy. Ethanol has very high research octane number (RON) and heat of vaporization (HoV), properties that make it an excellent spark ignition engine fuel. The prospects of increasing both the ethanol content and the octane number of the gasoline pool has the potential to enable improved fuel economy in future vehicles with downsized, downsped engines. This report describes a small study to explore the potential performance benefits of high octane ethanol blends in the legacy fleet. There are over 17 million flex-fuel vehicles (FFVs) on the road today in the United States, vehicles capable of using any fuel from E0 to E85. If a future high-octane blend for dedicated vehicles is on the horizon, the nation is faced with the classic chicken-and-egg dilemma. If today’s FFVs can see a performance advantage with a high octane ethanol blend such as E25 or E30, then perhaps consumer demand for this fuel can serve as a bridge to future dedicated vehicles. Experiments were performed with four FFVs using a 10% ethanol fuel (E10) with 88 pump octane, and a market gasoline blended with ethanol to make a 30% by volume ethanol fuel (E30) with 94 pump octane. The research octane numbers were 92.4 for the E10 fuel and 100.7 for the E30 fuel. Two vehicles had gasoline direct injected (GDI) engines, and two featured port fuel injection (PFI). Significant wide open throttle (WOT) performance improvements were measured for three of the four FFVs, with one vehicle showing no change. Additionally, a conventional (non-FFV) vehicle with a small turbocharged direct-injected engine was tested with a regular grade of gasoline with no ethanol (E0) and a splash blend of this same fuel with 15% ethanol by volume (E15). RON was increased from 90.7 for the E0 to 97.8 for the E15 blend. Significant wide open throttle and thermal efficiency performance

Highly stable cesium lead iodide perovskite quantum dot light-emitting diodes

Science.gov (United States)

Zou, Chen; Huang, Chun-Ying; Sanehira, Erin M.; Luther, Joseph M.; Lin, Lih Y.

2017-11-01

Recently, all-inorganic perovskites such as CsPbBr3 and CsPbI3, have emerged as promising materials for light-emitting applications. While encouraging performance has been demonstrated, the stability issue of the red-emitting CsPbI3 is still a major concern due to its small tolerance factor. Here we report a highly stable CsPbI3 quantum dot (QD) light-emitting diode (LED) with red emission fabricated using an improved purification approach. The device achieved decent external quantum efficiency (EQE) of 0.21% at a bias of 6 V and outstanding operational stability, with a L 70 lifetime (EL intensity decreases to 70% of starting value) of 16 h and 1.5 h under a constant driving voltage of 5 V and 6 V (maximum EQE operation) respectively. Furthermore, the device can work under a higher voltage of 7 V (maximum luminance operation) and retain 50% of its initial EL intensity after 500 s. These findings demonstrate the promise of CsPbI3 QDs for stable red LEDs, and suggest the feasibility for electrically pumped perovskite lasers with further device optimizations.

Highly strained InGaAs oxide confined VCSELs emitting in 1.25 μm

International Nuclear Information System (INIS)

Chang, S.J.; Yu, H.C.; Su, Y.K.; Chen, I.L.; Lee, T.D.; Lu, C.M.; Chiou, C.H.; Lee, Z.H.; Yang, H.P.; Sung, C.P.

2005-01-01

Highly strained GaAs-based all-epitaxial oxide confined vertical cavity surface emitting lasers (VCSELs) emitting in 1.25 μm were fabricated. Compared with the designed cavity resonance, it was found that lasing wavelength blue shifted by 29 nm when the driving current was small. The observation of such oxide mode is attributed to the effective optical thickness shrinkage of the oxide layer, and large detuning between the gain peak and cavity resonance

Nitrous Oxide (N2O) Emissions from Vehicles

International Nuclear Information System (INIS)

Becker, K.H.; Kurtenbach, R.; Lorzer, J.C.; Wiesen, P.; Jensen, T.; Wallington, T.J.

2000-01-01

N2O is an important greenhouse gas and accurate emission data are required to assess its impact on global climate. It is well established that automobiles, particularly those equipped with 3-way catalysts, emit N2O. However, the vehicle contribution to the global N2O budget is uncertain. We report results of N2O emission measurements performed in a road tunnel in Germany and using a chassis dynamometer system in the USA. We estimate that the global vehicle fleet emits (0.12±0.06) Tg yr-1 of N2O. From the emission factor (g N2O/g CO2) determined an annual N2O emission of (0.12±0.06) Tg yr-1 of N2O (0.08±0.04 Tg N yr-1) for the global vehicle fleet has been estimated which represents 1-4% of the atmospheric growth rate of this species. 9 refs

Determining optimum flash patterns for emergency service vehicles: an experimental investigation using high definition film.

Science.gov (United States)

Turner, Sally; Wylde, Julie; Langham, Martin; Morrow, Andrew

2014-09-01

An investigation of how emergency vehicle lighting (EVL) can be improved is reported with reference to an analysis of police vehicle road traffic accidents (Study 1). In Study 2, 37 regular drivers were shown film clips of a marked police vehicle, in which flash rate (1 Hz, 4 Hz) and pattern (single, triple pulse) were varied on the blue Light Emitting Diode (LED) roofbar. Results indicate a 4 Hz flash rate conveys greater urgency than a 1 Hz rate, while a 1 Hz, single flash combination was ranked the least urgent of all combinations. Participants claimed they would leave significantly more space before pulling out in front of an approaching police car (gap acceptance) in the 4 Hz single pulse condition in comparison to other EVL combinations. The preliminary implications for which flash characteristics could prove most optimal for emergency service use are discussed with regard to effects on driver perception and expected driving behaviour. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Highly efficient white organic light-emitting devices consisting of undoped ultrathin yellow phosphorescent layer

Energy Technology Data Exchange (ETDEWEB)

Liu, Shengqiang [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Ma, Zhu; Zhao, Juan [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

2013-02-15

High-efficiency white organic light-emitting devices (WOLEDs) based on an undoped ultrathin yellow light-emitting layer and a doped blue light-emitting layer were demonstrated. While the thickness of blue light-emitting layer, formed by doping a charge-trapping phosphor, iridium(III) bis(4 Prime ,6 Prime -difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate (FIr6) in a wide bandgap host, was kept constant, the thickness of neat yellow emissive layer of novel phosphorescent material, bis[2-(4-tertbutylphenyl)benzothiazolato-N,C{sup 2 Prime }]iridium (acetylacetonate) [(t-bt){sub 2}Ir(acac)] was varied to optimize the device performance. The optimized device exhibited maximum luminance, current efficiency and power efficiency of 24,000 cd/m{sup 2} (at 15.2 V), 79.0 cd/A (at 1550 cd/m{sup 2}) and 40.5 lm/W (at 1000 cd/m{sup 2}), respectively. Besides, the white-light emission covered a wide range of visible spectrum, and the Commission Internationale de l'Eclairage coordinates were (0.32, 0.38) with a color temperature of 5800 K at 8 V. Moreover, high external quantum efficiency was also obtained in the high-efficiency WOLEDs. The performance enhancement was attributed to the proper thickness of (t-bt){sub 2}Ir(acac) layer that enabled adequate current density and enough phosphorescent dye to trap electrons. - Highlights: Black-Right-Pointing-Pointer Highly efficient WOLEDs based on two complementary layers were fabricated. Black-Right-Pointing-Pointer The yellow emissive layer was formed by utilizing undoping system. Black-Right-Pointing-Pointer The blue emissive layer was made by host-guest doping system. Black-Right-Pointing-Pointer The thickness of the yellow emissive layer was varied to make device optimization. Black-Right-Pointing-Pointer The optimized device achieved high power efficiency of 40.5 lm/W.

Minautor: the 100% electric mining vehicle; Developpement d'un vehicule minier 100% electrique le Minautor

Energy Technology Data Exchange (ETDEWEB)

Adam, Francois

2011-04-15

PEDNO, in collaboration with Quebec's advanced transport institute (ITAQ) has developed a 4x4 fully electric vehicle suitable for use in mines. PEDNO undertook this project to replace diesel-powered vehicles which emit high levels of pollutants and push up ventilation costs. This vehicle, named Minautor, has certain features designed to meet the conditions of a subterranean environment: the body is made of aluminum to reduce weight and therefore the energy needed for mobility while Li-ion batteries, which are lighter and safer, have also been incorporated. After the vehicle was successfully tested, ITAQ transferred the technology to PEDNO so that they would be in a position to develop the next generation of the Minautor themselves.

High performance flexible top-emitting warm-white organic light-emitting devices and chromaticity shift mechanism

Energy Technology Data Exchange (ETDEWEB)

Shi, Hongying; Deng, Lingling; Chen, Shufen, E-mail: iamsfchen@njupt.edu.cn, E-mail: wei-huang@njupt.edu.cn; Xu, Ying; Zhao, Xiaofei; Cheng, Fan [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China); Huang, Wei, E-mail: iamsfchen@njupt.edu.cn, E-mail: wei-huang@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays (KLOEID) and Institute of Advanced Materials (IAM), Nanjing University of Posts and Telecommunications, 210023 Nanjing (China); Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Technology, Nanjing 211816 (China)

2014-04-15

Flexible warm-white top-emitting organic light-emitting devices (TEOLEDs) are fabricated onto PET substrates with a simple semi-transparent cathode Sm/Ag and two-color phosphors respectively doped into a single host material TCTA. By adjusting the relative position of the orange-red EML sandwiched between the blue emitting layers, the optimized device exhibits the highest power/current efficiency of 8.07 lm/W and near 13 cd/A, with a correlated color temperature (CCT) of 4105 K and a color rendering index (CRI) of 70. In addition, a moderate chromaticity variation of (-0.025, +0.008) around warm white illumination coordinates (0.45, 0.44) is obtained over a large luminance range of 1000 to 10000 cd/m{sup 2}. The emission mechanism is discussed via delta-doping method and single-carrier device, which is summarized that the carrier trapping, the exciton quenching, the mobility change and the recombination zone alteration are negative to color stability while the energy transfer process and the blue/red/blue sandwiched structure are contributed to the color stability in our flexible white TEOLEDs.

Acoustic Data for Hybrid and Electric Heavy-Duty Vehicles and Electric Motorcycles

Science.gov (United States)

2015-12-01

The Pedestrian Safety Enhancement Act (PSEA) of 2010 requires NHTSA to conduct a rulemaking to establish a Federal Motor Vehicle Safety Standard requiring an alert sound for pedestrians to be emitted by all types of motor vehicles that are electric o...

World-wide developments in motor vehicle inspection/maintenance (I/M) programs

Energy Technology Data Exchange (ETDEWEB)

Klausmeier, R. [Consulting Inc., Austin, TX (United States); Kishan, S. [Radian Corporation, Austin, TX (United States)

1995-12-31

Motor vehicles contribute much to urban air pollution. As a result, most governments have enacted emission standards that significantly lower pollutant emission levels from new motor vehicles. For example, vehicles built in the United States emit 95 % fewer pollutants than uncontrolled vehicles when they are new. However, studies indicate that proper maintenance is needed to obtain the full benefit of vehicle emission controls. Furthermore, there is evidence that a significant percentage of the vehicle fleet is not properly maintained. This has led to the creation of motor vehicle Inspection/Maintenance (I/M) Programs. I/M programs inspect vehicles for indications that they are emitting excessive quantities of pollutants. Vehicles that fail the inspection must be repaired in order to comply with program requirements. The first I/M programs were implemented in the United States in the early 1970s. With substantial urging from the federal government, most of the U.S. states with severe air pollution problems have implemented I/M programs. Recently, with the passage of the U.S. Clean Air Act Amendments of 1990, many states have been required to significantly upgrade the performance and coverage of their I/M programs. I/M programs also have been implemented in Europe and recently in Asia. This presentation reviews developments in I/M programs for light-duty gasoline powered vehicles. Developments in I/M programs for diesel powered vehicles are briefly described. (author)

World-wide developments in motor vehicle inspection/maintenance (I/M) programs

Energy Technology Data Exchange (ETDEWEB)

Klausmeier, R [Consulting Inc., Austin, TX (United States); Kishan, S [Radian Corporation, Austin, TX (United States)

1996-12-31

Motor vehicles contribute much to urban air pollution. As a result, most governments have enacted emission standards that significantly lower pollutant emission levels from new motor vehicles. For example, vehicles built in the United States emit 95 % fewer pollutants than uncontrolled vehicles when they are new. However, studies indicate that proper maintenance is needed to obtain the full benefit of vehicle emission controls. Furthermore, there is evidence that a significant percentage of the vehicle fleet is not properly maintained. This has led to the creation of motor vehicle Inspection/Maintenance (I/M) Programs. I/M programs inspect vehicles for indications that they are emitting excessive quantities of pollutants. Vehicles that fail the inspection must be repaired in order to comply with program requirements. The first I/M programs were implemented in the United States in the early 1970s. With substantial urging from the federal government, most of the U.S. states with severe air pollution problems have implemented I/M programs. Recently, with the passage of the U.S. Clean Air Act Amendments of 1990, many states have been required to significantly upgrade the performance and coverage of their I/M programs. I/M programs also have been implemented in Europe and recently in Asia. This presentation reviews developments in I/M programs for light-duty gasoline powered vehicles. Developments in I/M programs for diesel powered vehicles are briefly described. (author)

High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

International Nuclear Information System (INIS)

Miao Yan-Qin; Zhang Ai-Qin; Li Yuan-Hao; Wang Hua; Jia Hu-Sheng; Liu Xu-Guang; Gao Zhi-Xiang; Tsuboi Taijuf

2015-01-01

Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7, 7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. (paper)

High Time Resolution Measurements of VOCs from Vehicle Cold Starts: The Air Toxic Cold Start Pulse

Science.gov (United States)

Jobson, B. T.; Huangfu, Y.; Vanderschelden, G. S.

2017-12-01

Pollutants emitted during motor vehicle cold starts, especially in winter in some climates, is a significant source of winter time air pollution. While data exist for CO, NO, and total hydrocarbon emissions from federal testing procedures for vehicle emission certification, little is known about the emission rates of individual volatile organic compounds, in particular the air toxics benzene, formaldehyde, and acetaldehyde. Little is known about the VOC speciation and temperature dependence for cold starts. The US EPA vehicle emission model MOVES assumes that cold start emissions have the same speciation profile as running emissions. We examined this assumption by measuring cold start exhaust composition for 4 vehicles fueled with E10 gasoline over a temperature range of -4°C to 10°C in winter of 2015. The extra cold start emissions were determined by comparison with emissions during engine idling. In addition to CO and NOx measurements a proton transfer reaction mass spectrometer was used to measure formaldehyde, acetaldehyde, benzene, toluene, and C2-alkylbenzenes at high time resolution to compare with the cold start emission speciation profiles used in the EPA MOVES2014 model. The results show that after the vehicle was started, CO mixing ratios can reach a few percent of the exhaust and then drop to several ppmv within 2 minutes of idling, while NOx showed different temporal behaviors among the four vehicles. VOCs displayed elevated levels during cold start and the peak mixing ratios can be two orders higher than idling phase levels. Molar emission ratios relative to toluene were used to compare with the emission ratio used in MOVES2014 and we found the formaldehyde-to-toluene emission ratio was about 0.19, which is 5 times higher than the emission ratio used in MOVES2014 and the acetaldehyde-to-toluene emission ratios were 0.86-0.89, which is 8 times higher than the ones in MOVES2014. The C2-alkylbenzene-to-toluene ratio agreed well with moves. Our results

White organic light-emitting devices with high color purity and stability

Science.gov (United States)

Bai, Yajie; Liu, Su; Li, Hairong; Liu, Chunjuan; Wang, Jinshun; Chang, Jinxian

2014-04-01

A white organic light-emitting device (WOLED) with dual-emitting layers was presented, in which the blue fluorescent dye 2,5,8,11-terta-tertbutylperylene (TBPe) was doped in 2-methyl-9, 10-di(2-naphthyl)-anthracene (MADN) as a blue-emitting layer, while 5,6,11,12-tetraphenylnaphthacene (rubrene, Rb) was doped in the above-mentioned materials as a yellow-emitting layer. The fabricated monochromatic devices using the blue- and yellow-emitting layer have demonstrated that the direct charge trapping mechanism is the dominant emission mechanism in the yellow OLED. Studies on the WOLEDs with dual-emitting layers have shown that the performances of these devices are strongly susceptible to the thickness of the emitting layer and the stack order of two emitting layers. Structure of ITO(160 nm)/NPB(30 nm)/MADN: 5 wt%TBPe: 3 wt%Rb(10 nm)/MADN: 5 wt%TBPe(20 nm)/BCP (10 nm)/Alq3(20 nm)/Al(100 nm) was determined to be the most favorable WOLED. The maximum luminance of 16 000 cd cm-2 at the applied voltage of 13.4 V and Commission International de 1‧Eclairage (CIE) coordinates of (0.3263, 0.3437) which is closer to the standard white light (CIE (0.33, 0.33)) than the most recent reported WOLEDs were obtained. Moreover, there is just slight variation of CIE coordinates (ΔCIEx, y = 0.0171, 0.0167; corresponding Δu‧v‧ = 0.0119) when the current density increases from 10 to 100 mA cm-2. It reveals that the emissive dopant Rb acts as charge traps to improve electron-hole balance, provides sites for electron-hole recombination and thus makes carriers distribute more evenly in the dual-emitting layers which broaden the recombination zone and improve the stability of the CIE coordinates.

Economical and environmental assessments of compressed natural gas for diesel vehicle in Thailand

Directory of Open Access Journals (Sweden)

Prateep Chouykerd

2008-08-01

Full Text Available The economic assessments for the use of compressed natural gas as fuel for several types of diesel vehicles, rarely pick up, non-fixed route truck and private truck, were studied. It is noted that two main technologies of diesel natural gas vehicle (NGV, i.e. dedicated retrofit and diesel dual fuel (DDF, were considered in this work. It was found that the dedicated retrofit needs higher investment costs than dual fuel, but can achieve higher diesel saving than dual fuel. In detail, the payback period of dual fuel non-fixed route truck was found to be identical to dual fuel private truck both in the cases of6 wheel and 10 wheel, while dedicated retrofit non-fixed route truck and private truck are also identical and have longerpay back period than dual fuel due to its higher conversion costs.This work also presents the emissions released from all types of engines especially green house gas CO2. It was found that, in the case of light duty diesel i.e. pickup truck, dedicated retrofit emitted high level of CO2 than both dual fuel and conventional diesel engines. For heavy duty i.e. non-fixed route truck and private truck vehicles, dedicated retrofit emitted a lower level of CO2 than normal diesel engine. Other pollutants from engine emission, i.e. hydrocarbon (HC,nitric oxide (NOx, carbon monoxide (CO and particulate matter, (PM were also observed. The results indicated that, inthe case of light duty diesel, dedicated retrofit engine emits higher levels of HC and CO than diesel engine; in contrast, it emits lower level of NOx and PM than diesel and dual fuel. Dual fuel emits HC and CO higher than diesel and dedicated retrofit but emits lower level of NOx and PM than diesel. Lastly, for heavy duty diesel, it was demonstrated that non-fixed route truck and private truck heavy duty dedicated retrofit have potential to reduce emissions of HC, NOx, CO and PM when compared to normal heavy duty diesel. Engine efficiencies under dual fuel and dedicated

Advances in fuel cell vehicle design

Science.gov (United States)

Bauman, Jennifer

Factors such as global warming, dwindling fossil fuel reserves, and energy security concerns combine to indicate that a replacement for the internal combustion engine (ICE) vehicle is needed. Fuel cell vehicles have the potential to address the problems surrounding the ICE vehicle without imposing any significant restrictions on vehicle performance, driving range, or refuelling time. Though there are currently some obstacles to overcome before attaining the widespread commercialization of fuel cell vehicles, such as improvements in fuel cell and battery durability, development of a hydrogen infrastructure, and reduction of high costs, the fundamental concept of the fuel cell vehicle is strong: it is efficient, emits zero harmful emissions, and the hydrogen fuel can be produced from various renewable sources. Therefore, research on fuel cell vehicle design is imperative in order to improve vehicle performance and durability, increase efficiency, and reduce costs. This thesis makes a number of key contributions to the advancement of fuel cell vehicle design within two main research areas: powertrain design and DC/DC converters. With regards to powertrain design, this research first analyzes various powertrain topologies and energy storage system types. Then, a novel fuel cell-battery-ultracapacitor topology is presented which shows reduced mass and cost, and increased efficiency, over other promising topologies found in the literature. A detailed vehicle simulator is created in MATLAB/Simulink in order to simulate and compare the novel topology with other fuel cell vehicle powertrain options. A parametric study is performed to optimize each powertrain and general conclusions for optimal topologies, as well as component types and sizes, for fuel cell vehicles are presented. Next, an analytical method to optimize the novel battery-ultracapacitor energy storage system based on maximizing efficiency, and minimizing cost and mass, is developed. This method can be applied

Light emitting diode with high aspect ratio submicron roughness for light extraction and methods of forming

Science.gov (United States)

Li, Ting [Ventura, CA

2011-04-26

The surface morphology of an LED light emitting surface is changed by applying a reactive ion etch (RIE) process to the light emitting surface. High aspect ratio, submicron roughness is formed on the light emitting surface by transferring a thin film metal hard-mask having submicron patterns to the surface prior to applying a reactive ion etch process. The submicron patterns in the metal hard-mask can be formed using a low cost, commercially available nano-patterned template which is transferred to the surface with the mask. After subsequently binding the mask to the surface, the template is removed and the RIE process is applied for time duration sufficient to change the morphology of the surface. The modified surface contains non-symmetric, submicron structures having high aspect ratio which increase the efficiency of the device.

Highly efficient and simplified phosphorescence white organic light-emitting diodes based on synthesized deep-blue host and orange emitter

Energy Technology Data Exchange (ETDEWEB)

Koo, Ja Ryong; Lee, Seok Jae; Hyung, Gun Woo; Kim, Bo Young; Lee, Dong Hyung [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Woo Young [Department of Green Energy and Semiconductor Engineering, Hoseo University, Asan 336-795 (Korea, Republic of); Lee, Kum Hee [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of)

2013-10-01

The authors have demonstrated a highly efficient and stable phosphorescent white organic light-emitting diode (WOLED), which has been achieved by doping only one orange phosphorescent emitter, Bis(5-benzoyl-2-(4-fluorophenyl)pyridinato-C,N)iridium(III) acetylacetonate into an appropriate deep blue phosphorescent host, 4,4'-bis(4-(triphenylsilyl)phenyl)-1,1'-binaphthyl as an emitting layer (EML). The WOLED has been achieved by effective confinement of triplet excitons to emit a warm white color. The optimized WOLED, with a simple structure as a hole transporting layer-EML-electron transporting layer, showed a maximum luminous efficiency of 22.38 cd/A, a maximum power efficiency of 12.01 lm/W, a maximum external quantum efficiency of 7.32%, and CIEx,y coordinates of (0.38,0.42) at 500 cd/m{sup 2}, respectively. - Highlights: • Highly efficient phosphorescent white organic light-emitting diode (WOLED) • Single emitting layer consists of synthesized deep blue host and orange emitter • The WOLED with high EL efficiencies due to efficient triplet exciton confinement.

The impact of electric vehicles on CO2 emissions

International Nuclear Information System (INIS)

Bentley, J.M.; Teagan, P.; Walls, D.; Balles, E.; Parish, T.

1992-05-01

A number of recent studies have examined the greenhouse gas emissions of various light duty vehicle alternatives in some detail. These studies have highlighted the extreme range of predicted net greenhouse gas emissions depending on scenarios for fuel types, vehicle and power generation efficiencies, the relative greenhouse contributions of emitted gases and a number of uncertainties in fuel chain efficiencies. Despite the potential range of results, most studies have confirmed that electric vehicles generally have significant potential for reducing greenhouse gas emissions relative to gasoline and most alternative fuels under consideration. This report summarizes the results of a study which builds on previous efforts with a particular emphasis on: (1) A detailed analysis of ICEV, FCV, and EV vehicle technology and electric power generation technology. Most previous transportation greenhouse studies have focused on characterization of fuel chains that have relatively high efficiency (65--85%) when compared with power generation (30--40%) and vehicle driveline (13--16%) efficiencies. (2) A direct comparison of EVs, FCVs with gasoline and dedicated alternative fuel, ICEVs using equivalent vehicle technology assumptions with careful attention to likely technology improvements in both types of vehicles. (3) Consideration of fuel cell vehicles and associated hydrogen infrastructure. (4) Extension of analyses for several decades to assess the prospects for EVs with a longer term prospective

Highly efficient phosphorescent blue and white organic light-emitting devices with simplified architectures

Energy Technology Data Exchange (ETDEWEB)

Chang, Chih-Hao, E-mail: chc@saturn.yzu.edu.tw [Department of Photonics Engineering, Yuan Ze University, Chung-Li, Taiwan 32003 (China); Ding, Yong-Shung; Hsieh, Po-Wei; Chang, Chien-Ping; Lin, Wei-Chieh [Department of Photonics Engineering, Yuan Ze University, Chung-Li, Taiwan 32003 (China); Chang, Hsin-Hua, E-mail: hhua3@mail.vnu.edu.tw [Department of Electro-Optical Engineering, Vanung University, Chung-Li, Taiwan 32061 (China)

2011-09-01

Blue phosphorescent organic light-emitting devices (PhOLEDs) with quantum efficiency close to the theoretical maximum were achieved by utilizing a double-layer architecture. Two wide-triplet-gap materials, 1,3-bis(9-carbazolyl)benzene and 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, were employed in the emitting and electron-transport layers respectively. The opposite carrier-transport characteristics of these two materials were leveraged to define the exciton formation zone and thus increase the probability of recombination. The efficiency at practical luminance (100 cd/m{sup 2}) was as high as 20.8%, 47.7 cd/A and 31.2 lm/W, respectively. Furthermore, based on the design concept of this simplified architecture, efficient warmish-white PhOLEDs were developed. Such two-component white organic light-emitting devices exhibited rather stable colors over a wide brightness range and yielded electroluminescence efficiencies of 15.3%, 33.3 cd/A, and 22.7 lm/W in the forward directions.

Highly efficient phosphorescent blue and white organic light-emitting devices with simplified architectures

International Nuclear Information System (INIS)

Chang, Chih-Hao; Ding, Yong-Shung; Hsieh, Po-Wei; Chang, Chien-Ping; Lin, Wei-Chieh; Chang, Hsin-Hua

2011-01-01

Blue phosphorescent organic light-emitting devices (PhOLEDs) with quantum efficiency close to the theoretical maximum were achieved by utilizing a double-layer architecture. Two wide-triplet-gap materials, 1,3-bis(9-carbazolyl)benzene and 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, were employed in the emitting and electron-transport layers respectively. The opposite carrier-transport characteristics of these two materials were leveraged to define the exciton formation zone and thus increase the probability of recombination. The efficiency at practical luminance (100 cd/m 2 ) was as high as 20.8%, 47.7 cd/A and 31.2 lm/W, respectively. Furthermore, based on the design concept of this simplified architecture, efficient warmish-white PhOLEDs were developed. Such two-component white organic light-emitting devices exhibited rather stable colors over a wide brightness range and yielded electroluminescence efficiencies of 15.3%, 33.3 cd/A, and 22.7 lm/W in the forward directions.

White organic light-emitting devices with high color purity and stability

International Nuclear Information System (INIS)

Bai, Yajie; Liu, Su; Li, Hairong; Liu, Chunjuan; Wang, Jinshun; Chang, Jinxian

2014-01-01

A white organic light-emitting device (WOLED) with dual-emitting layers was presented, in which the blue fluorescent dye 2,5,8,11-terta-tertbutylperylene (TBPe) was doped in 2-methyl-9, 10-di(2-naphthyl)-anthracene (MADN) as a blue-emitting layer, while 5,6,11,12-tetraphenylnaphthacene (rubrene, Rb) was doped in the above-mentioned materials as a yellow-emitting layer. The fabricated monochromatic devices using the blue- and yellow-emitting layer have demonstrated that the direct charge trapping mechanism is the dominant emission mechanism in the yellow OLED. Studies on the WOLEDs with dual-emitting layers have shown that the performances of these devices are strongly susceptible to the thickness of the emitting layer and the stack order of two emitting layers. Structure of ITO(160 nm)/NPB(30 nm)/MADN: 5 wt%TBPe: 3 wt%Rb(10 nm)/MADN: 5 wt%TBPe(20 nm)/BCP (10 nm)/Alq 3 (20 nm)/Al(100 nm) was determined to be the most favorable WOLED. The maximum luminance of 16 000 cd cm −2  at the applied voltage of 13.4 V and Commission International de 1′Eclairage (CIE) coordinates of (0.3263, 0.3437) which is closer to the standard white light (CIE (0.33, 0.33)) than the most recent reported WOLEDs were obtained. Moreover, there is just slight variation of CIE coordinates (ΔCIE x, y = 0.0171, 0.0167; corresponding Δu′v′ = 0.0119) when the current density increases from 10 to 100 mA cm −2 . It reveals that the emissive dopant Rb acts as charge traps to improve electron–hole balance, provides sites for electron–hole recombination and thus makes carriers distribute more evenly in the dual-emitting layers which broaden the recombination zone and improve the stability of the CIE coordinates. (paper)

Highly Efficient Perovskite-Quantum-Dot Light-Emitting Diodes by Surface Engineering

KAUST Repository

Pan, Jun; Quan, Li Na; Zhao, Yongbiao; Peng, Wei; Banavoth, Murali; Sarmah, Smritakshi P.; Yuan, Mingjian; Sinatra, Lutfan; AlYami, Noktan; Liu, Jiakai; Yassitepe, Emre; Yang, Zhenyu; Voznyy, Oleksandr; Comin, Riccardo; Hedhili, Mohamed N.; Mohammed, Omar F.; Lu, Zheng Hong; Kim, Dong Ha; Sargent, Edward H.; Bakr, Osman

2016-01-01

A two-step ligand-exchange strategy is developed, in which the long-carbon-chain ligands on all-inorganic perovskite (CsPbX3, X = Br, Cl) quantum dots (QDs) are replaced with halide-ion-pair ligands. Green and blue light-emitting diodes made from the halide-ion-paircapped quantum dots exhibit high external quantum efficiencies compared with the untreated QDs.

Highly Efficient Perovskite-Quantum-Dot Light-Emitting Diodes by Surface Engineering

KAUST Repository

Pan, Jun

2016-08-16

A two-step ligand-exchange strategy is developed, in which the long-carbon-chain ligands on all-inorganic perovskite (CsPbX3, X = Br, Cl) quantum dots (QDs) are replaced with halide-ion-pair ligands. Green and blue light-emitting diodes made from the halide-ion-paircapped quantum dots exhibit high external quantum efficiencies compared with the untreated QDs.

Best practices : bus signage for persons with visual impairments : light-emitting diode (LED) signs

Science.gov (United States)

2004-01-01

This best-practices report provides key information regarding the use of Light-Emitting Diode (LED) sign technologies to present destination and route information on transit vehicles. It will assist managers and engineers in the acquisition and use o...

High-efficiency white organic light-emitting diodes using thermally activated delayed fluorescence

International Nuclear Information System (INIS)

Nishide, Jun-ichi; Hiraga, Yasuhide; Nakanotani, Hajime; Adachi, Chihaya

2014-01-01

White organic light-emitting diodes (WOLEDs) have attracted much attention recently, aimed for next-generation lighting sources because of their high potential to realize high electroluminescence efficiency, flexibility, and low-cost manufacture. Here, we demonstrate high-efficiency WOLED using red, green, and blue thermally activated delayed fluorescence materials as emissive dopants to generate white electroluminescence. The WOLED has a maximum external quantum efficiency of over 17% with Commission Internationale de l'Eclairage coordinates of (0.30, 0.38).

Stability control for high speed tracked unmanned vehicles

Science.gov (United States)

Pape, Olivier; Morillon, Joel G.; Houbloup, Philippe; Leveque, Stephane; Fialaire, Cecile; Gauthier, Thierry; Ropars, Patrice

2005-05-01

The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales as the prime contractor, focuses on about 15 robotic themes which can provide an immediate "operational add-on value". The paper details the "automatic speed adjustment" behavior (named SYR4), developed by Giat Industries Company, which main goal is to secure the teleoperated mobility of high speed tracked vehicles on rough grounds; more precisely, the validated low level behavior continuously adjusts the vehicle speed taking into account the teleperator wish AND the maximum speed that the vehicle can manage safely according to the commanded radius of curvature. The algorithm is based on a realistic physical model of the ground-tracks relation, taking into account many vehicle and ground parameters (such as ground adherence and dynamic specificities of tracked vehicles). It also deals with the teleoperator-machine interface, providing a balanced strategy between both extreme behaviors: a) maximum speed reduction before initiating the commanded curve; b) executing the minimum possible radius without decreasing the commanded speed. The paper presents the results got from the military acceptance tests performed on tracked SYRANO vehicle (French Operational Demonstrator).

Highly Efficient White Organic Light-Emitting Diodes with Ultrathin Emissive Layers and a Spacer-Free Structure

Science.gov (United States)

Wu, Shengfan; Li, Sihua; Sun, Qi; Huang, Chenchao; Fung, Man-Keung

2016-05-01

Ultrathin emissive layers (UEMLs) of phosphorescent materials with a layer thickness of less than 0.3 nm were introduced for high-efficiency organic light-emitting diodes (OLEDs). All the UEMLs for white OLEDs can be prepared without the use of interlayers or spacers. Compared with devices fabricated with interlayers inserted in-between the UEMLs, our spacer-free structure not only significantly improves device efficiency, but also simplifies the fabrication process, thus it has a great potential in lowering the cost of OLED panels. In addition, its spacer-free structure decreases the number of interfaces which often introduce unnecessary energy barriers in these devices. In the present work, UEMLs of red, green and blue-emitting phosphorescent materials and yellow and blue phosphorescent emitters are utilized for the demonstration of spacer-free white OLEDs. Upon optimization of the device structure, we demonstrated spacer-free and simple-structured white-emitting OLEDs with a good device performance. The current and power efficiencies of our white-emitting devices are as high as 56.0 cd/A and 55.5 lm/W, respectively. These efficiencies are the highest ever reported for OLEDs fabricated with the UEML approach.

On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles

Science.gov (United States)

2006-02-17

On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles Report Title ABSTRACT In this work we proposed two semi-analytic...298-102 Enclosure 1 On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles by...Specifically, the following problems will be addressed during this project: 2.1 Challenges The problem of trajectory planning for high-speed autonomous vehicles is

Characterization of particulate matter emissions from on-road gasoline and diesel vehicles using a soot particle aerosol mass spectrometer

OpenAIRE

Dallmann, T. R.; Onasch, T. B.; Kirchstetter, T. W.; Worton, D. R.; Fortner, E. C.; Herndon, S. C.; Wood, E. C.; Franklin, J. P.; Worsnop, D. R.; Goldstein, A. H.; Harley, R. A.

2014-01-01

Particulate matter (PM) emissions were measured in July 2010 from on-road motor vehicles driving through a highway tunnel in the San Francisco Bay area. A soot particle aerosol mass spectrometer (SP-AMS) was used to measure the chemical composition of PM emitted by gasoline and diesel vehicles at high time resolution. Organic aerosol (OA) and black carbon (BC) concentrations were measured during various time periods that had different levels of diesel influence, as well as d...

A telescopic cinema sound camera for observing high altitude aerospace vehicles

Science.gov (United States)

Slater, Dan

2014-09-01

Rockets and other high altitude aerospace vehicles produce interesting visual and aural phenomena that can be remotely observed from long distances. This paper describes a compact, passive and covert remote sensing system that can produce high resolution sound movies at >100 km viewing distances. The telescopic high resolution camera is capable of resolving and quantifying space launch vehicle dynamics including plume formation, staging events and payload fairing jettison. Flight vehicles produce sounds and vibrations that modulate the local electromagnetic environment. These audio frequency modulations can be remotely sensed by passive optical and radio wave detectors. Acousto-optic sensing methods were primarily used but an experimental radioacoustic sensor using passive micro-Doppler radar techniques was also tested. The synchronized combination of high resolution flight vehicle imagery with the associated vehicle sounds produces a cinema like experience that that is useful in both an aerospace engineering and a Hollywood film production context. Examples of visual, aural and radar observations of the first SpaceX Falcon 9 v1.1 rocket launch are shown and discussed.

High-efficient and brightness white organic light-emitting diodes operated at low bias voltage

Science.gov (United States)

Zhang, Lei; Yu, Junsheng; Yuan, Kai; Jian, Yadong

2010-10-01

White organic light-emitting diodes (OLEDs) used for display application and lighting need to possess high efficiency, high brightness, and low driving voltage. In this work, white OLEDs consisted of ambipolar 9,10-bis 2-naphthyl anthracene (ADN) as a host of blue light-emitting layer (EML) doped with tetrabutyleperlene (TBPe) and a thin codoped layer consisted of N, N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (NPB) as a host of yellow light-emitting layer doped with 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) were investigated. With appropriate tuning in the film thickness, position, and dopant concentration of the co-doped layer, a white OLED with a luminance yield of 10.02 cd/A with the CIE coordinates of (0.29, 0.33) has been achieved at a bias voltage of 9 V and a luminance level of over 10,000 cd/m2. By introducing the PIN structure with both HIL and bis(10- hydroxybenzo-quinolinato)-beryllium (BeBq2) ETL, the power efficiency of white OLED was improved.

Quantifying the contribution of individual vehicles to NO2 pollution in an urban area

Science.gov (United States)

Pöhler, Denis; Kanatschnig, Florian; Horbanski, Martin; Friedrich, Axel; Lampel, Johannes; Platt, Ulrich

2015-04-01

Nitrogen Dioxide (NOx) emissions by road vehicles are the mayor contributor for poor air quality in urban areas. High NOx concentrations, and especially NO2, are typically the most problematic pollutant in mega and other cities. However emissions vary significantly depending on the type of vehicle and its engine, the age and condition of the vehicle, driving properties and many more. Even if data of the manufacturer exists how much NOx different vehicle types emit, reliable data under real driving conditions are rare and often missing. Especially data showing the degree to which different cars contribute to observed NOx levels are missing. Significant reduction of NOx concentrations can be achieved by identifying the strong emitting vehicles and excluding / replacing these. As this is only a small amount of vehicles (typically less than 10% of the vehicles make 90% of the emissions), such a small investment can significantly improve air quality. In order to perform measurements of NOx we applied a high speed NO2 CE-DOAS (Cavity-Enhanced DOAS) instrument in a car which was modified for this application. It measured directly the NO2 concentration behind followed vehicles while driving, with a time resolution of 2 s and an accuracy of ~1ppb. Even if such observations depend on many parameters like mixing-in of ambient air, distance, solar radiation, ozone concentration, background concentration etc., it delivers valuable data under real driving conditions. The instrument was applied in the city of Mainz, Germany to investigate within 7 days (March / April 2014) the NOx emission of 728 vehicles and to quantify the main emitters. Therefore the measured NO2 concentration in comparison to the background concentrations was quantified. Observed vehicles were separated in 4 categories: cars, busses, trucks, and motorcycles. We observed NO2 levels from a few ppb (within the background variation) up to 7000ppb NO2 above the background level. Strong variations within the same

Canadian high speed magnetically levitated vehicle system

Energy Technology Data Exchange (ETDEWEB)

Atherton, D L [Queen' s Univ., Kingston, Ont.; Belanger, P R; Burke, P E; Dawson, G E; Eastham, A R; Hayes, W F; Ooi, B T; Silvester, P; Slemon, G R

1978-04-01

A technically feasible high speed (400 to 480 km/h) guided ground transportation system, based on the use of the vehicle-borne superconducting magnets for electrodynamic suspension and guidance and for linear synchronous motor propulsion was defined as a future modal option for Canadian application. Analysis and design proposals were validated by large-scale tests on a rotating wheel facility and by modelling system components and their interactions. Thirty ton vehicles carrying 100 passengers operate over a flat-topped elevated guideway, which minimizes system down-time due to ice and snow accumulation and facilitates the design of turn-outs. A clearance of up to 15 cm is produced by the electrodynamic interaction between the vehicle-borne superconducting magnets and aluminum guideway strips. Propulsion and automatic system control is provided by the superconducting linear synchronous motor which operates at good efficiency (0.74) and high power factor (0.95). The vehicle is guided primarily by the interaction between the LSM field magnet array and flat null-flux loops overlying the stator windings in the guideway. The linear synchronous motor, electrodynamic suspension as well as levitation strip joints, parasitic LSM winding losses and limitations to the use of ferromagnetic guideway reinforcement were investigated experimentally on the test wheel facility. The use of a secondary suspension assures adequate dynamic stability, and good ride quality is achieved by optimized passive components with respect to lateral modes and by an actively controlled secondary suspension with respect to vertical motion.

Modeling Single Occupant Vehicle Behavior in High-Occupancy Toll (HOT) Facilities

Science.gov (United States)

2009-12-14

High-occupancy toll (HOT) lanes are in operation, under construction, and planned for in several major metropolitan areas. The premise behind HOT lanes is to allow single occupant vehicles (SOVs) to access high occupancy vehicle (HOV) lanes (and theo...

Hidden benefits of electric vehicles for addressing climate change.

Science.gov (United States)

Li, Canbing; Cao, Yijia; Zhang, Mi; Wang, Jianhui; Liu, Jianguo; Shi, Haiqing; Geng, Yinghui

2015-03-19

There is an increasingly hot debate on whether the replacement of conventional vehicles (CVs) by electric vehicles (EVs) should be delayed or accelerated since EVs require higher cost and cause more pollution than CVs in the manufacturing process. Here we reveal two hidden benefits of EVs for addressing climate change to support the imperative acceleration of replacing CVs with EVs. As EVs emit much less heat than CVs within the same mileage, the replacement can mitigate urban heat island effect (UHIE) to reduce the energy consumption of air conditioners, benefitting local and global climates. To demonstrate these effects brought by the replacement of CVs by EVs, we take Beijing, China, as an example. EVs emit only 19.8% of the total heat emitted by CVs per mile. The replacement of CVs by EVs in 2012 could have mitigated the summer heat island intensity (HII) by about 0.94°C, reduced the amount of electricity consumed daily by air conditioners in buildings by 14.44 million kilowatt-hours (kWh), and reduced daily CO2 emissions by 10,686 tonnes.

Ammonia, nitrous oxide and hydrogen cyanide emissions from five passenger vehicles

International Nuclear Information System (INIS)

Karlsson, Hua Lu

2004-01-01

In this paper, three unregulated components, ammonia, nitrous oxide and hydrogen cyanide, emitted from five passenger vehicles are investigated. With focus upon emission factors from existing production technology, vehicles produced between 1989 and 1998 with considerable mileage (7000 to 280,000) are chosen. Among the five vehicles, four were sold in the European market, whereas one was sold in the US market. The vehicles are tested on a chassis dynamometer. An EU2000 Driving Cycle (NEDC) and a US Urban Driving Cycle (UDC) of the Federal Test Procedure 75 (FTP-75) are used in the study. The regulated emissions are measured using a Horiba Mexa series. Unregulated emissions, ammonia (NH 3 ), nitrous oxide (N 2 O) and hydrogen cyanide (HCN) are analysed by mass spectrometer, gas chromatography and CNT-NA, TIM315-74W method, respectively. Both the unregulated emissions and the regulated emissions show driving cycle dependency; and they are also improved with newer vehicle and emission control technology. However, a gasoline direct injection vehicle (relatively new technology in this study) has rather high regulated emissions, whereas the NH 3 , N 2 O and HCN emissions are low

Ammonia, nitrous oxide and hydrogen cyanide emissions from five passenger vehicles.

Science.gov (United States)

Karlsson, Hua Lu

2004-12-01

In this paper, three unregulated components, ammonia, nitrous oxide and hydrogen cyanide, emitted from five passenger vehicles are investigated. With focus upon emission factors from existing production technology, vehicles produced between 1989 and 1998 with considerable mileage (7000 to 280,000) are chosen. Among the five vehicles, four were sold in the European market, whereas one was sold in the US market. The vehicles are tested on a chassis dynamometer. An EU2000 Driving Cycle (NEDC) and a US Urban Driving Cycle (UDC) of the Federal Test Procedure 75 (FTP-75) are used in the study. The regulated emissions are measured using a Horiba Mexa series. Unregulated emissions, ammonia (NH(3)), nitrous oxide (N(2)O) and hydrogen cyanide (HCN) are analysed by mass spectrometer, gas chromatography and CNT-NA, TIM315-74W method, respectively. Both the unregulated emissions and the regulated emissions show driving cycle dependency; and they are also improved with newer vehicle and emission control technology. However, a gasoline direct injection vehicle (relatively new technology in this study) has rather high regulated emissions, whereas the NH(3), N(2)O and HCN emissions are low.

Highly efficient exciplex organic light-emitting diodes using thermally activated delayed fluorescent emitters as donor and acceptor materials

Science.gov (United States)

Jeon, Sang Kyu; Yook, Kyoung Soo; Lee, Jun Yeob

2016-06-01

Highly efficient exciplex type organic light-emitting diodes were developed using thermally activated delayed fluorescent emitters as donors and acceptors of an exciplex. Blue emitting bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (DMAC-DPS) was a donor and 9,9‧-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)-1,3-phenylene)bis(9H-carbazole) (DDCzTrz) and 9,9‧,9″-(5-(4,6-diphenyl-1,3,5-triazin-2-yl)benzene-1,2,3-triyl)tris(9H-carbazole) (TCzTrz) were acceptor materials. The exciplexes of DMAC-DPS:TCzTrz and DMAC-DPS:DDCzTrz resulted in high photoluminescence quantum yield and high quantum efficiency in the green exciplex organic light-emitting diodes. High quantum efficiencies of 13.4% and 15.3% were obtained in the DMAC-DPS:DDCzTrz and DMAC-DPS:TCzTrz exciplex devices.

2 W high efficiency PbS mid-infrared surface emitting laser

Science.gov (United States)

Ishida, A.; Sugiyama, Y.; Isaji, Y.; Kodama, K.; Takano, Y.; Sakata, H.; Rahim, M.; Khiar, A.; Fill, M.; Felder, F.; Zogg, H.

2011-09-01

High efficiency laser operation with output power exceeding 2 W was obtained for vertical external-cavity PbS based IV-VI compound surface emitting quantum-well structures. The laser showed external quantum efficiency as high as 16%. Generally, mid-infrared III-V or II-VI semiconductor laser operation utilizing interband electron transitions are restricted by Auger recombination and free carrier absorption. Auger recombination is much lower in the IV-VI semiconductors, and the free-carrier absorption is significantly reduced by an optically pumped laser structure including multi-step optical excitation layers.

High tunability and superluminescence in InAs mid-infrared light emitting diodes

International Nuclear Information System (INIS)

Sherstnev, V.V.; Krier, A.; Hill, G.

2002-01-01

We report on the observation of super luminescence and high spectral current tunability (181 nm) of InAs light emitting diodes operating at 3.0 μm. The source is based on an optical whispering gallery mode which is generated near the edges of the mesa and which is responsible for the superluminescence. (author)

Prediction and design of efficient exciplex emitters for high-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes.

Science.gov (United States)

Liu, Xiao-Ke; Chen, Zhan; Zheng, Cai-Jun; Liu, Chuan-Lin; Lee, Chun-Sing; Li, Fan; Ou, Xue-Mei; Zhang, Xiao-Hong

2015-04-08

High-efficiency, thermally activated delayed-fluorescence organic light-emitting diodes based on exciplex emitters are demonstrated. The best device, based on a TAPC:DPTPCz emitter, shows a high external quantum efficiency of 15.4%. Strategies for predicting and designing efficient exciplex emitters are also provided. This approach allow prediction and design of efficient exciplex emitters for achieving high-efficiency organic light-emitting diodes, for future use in displays and lighting applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concerning the debate on electric-powered-vehicle emissions

International Nuclear Information System (INIS)

Sporckmann, B.

1994-01-01

The fact that electric-powered vehicles do not emit pollutants locally is obvious and must be considered as the main motive for their use. The global air pollution situation can only be of secondary importance because within the foreseeable future emissions linked to the use of electric-powered vehicles will remain within the variation width of power generation emissions that is not to be influenced. All the same, it is indispensable to consider the global situation. The author compares electric-powered vehicles with conventional ones by referring to the power generation of all federal German states. (orig.) [de

Passive Shielding Effect on Space Profile of Magnetic Field Emissions for Wireless Power Transfer to Vehicles

DEFF Research Database (Denmark)

Batra, Tushar; Schaltz, Erik

2015-01-01

Magnetic fields emitted by wireless power transfer systems are of high importance with respect to human safety and health. Aluminum and ferrite are used in the system to reduce the fields and are termed as passive shielding. In this paper, the influence of these materials on the space profile has...... fields for wireless power transfer for vehicle applications....

Aero particles characterization emitted by mobile sources

International Nuclear Information System (INIS)

Rojas V, A.; Romero G, E. T.; Lopez G, H.

2009-01-01

In our country, the mobile sources that conform most of the emissions at the atmosphere, are concentrated on the urban areas. For the present work, samples coming from the escapes of terrestrial transport were obtained, such as: passenger buses, load transport and particular vehicles of the Metropolitan area of the Toluca valley. The material was analyzed by means of scanning electron microscopy of low vacuum and X-ray diffraction. The objective was to characterize the emitted particles by mobile sources, morphological and chemically to know the structure, size and elements that compose them. (Author)

Angular distributions of nucleons emitted in high energy hadron-nucleus collisions

International Nuclear Information System (INIS)

Strugalski, Z.

1983-01-01

Angular distributions of ''fast'' protons, of kinetic energy from about 20 to about 400 MeV, emitted in pion-xenon nucleus collisions at 3.5 GeV/c momentum were studied in two groups of events - when particles are produced and when particle production does not occur. The distributions are practically the same in both the groups of events and in subgroups of events with various multiplicities of emitted protons. Comparison of angular distributions of protons emitted in pion-xenon nucleus collisions at 3.5 GeV/c momentum with corresponding angular distributions of protons emitted in proton-emulsion collisions at 300-400 GeV/c momentum is performed. Results obtained allow to conclude that average value of the nucleon emission angle and the nucleon angular distributions do not depend practically on the nuclear matter layer thickness the incident hadron collided with. Fast nucleons emitted from the target nucleus seem did not interact inside the parent nucleus. Fast nucleon angular distributions do not depend on the energy of incident hadron, they are the same for pion-nucleus and for proton-nucleus collisions as well

Recent developments in white light emitting diodes

Science.gov (United States)

Lohe, P. P.; Nandanwar, D. V.; Belsare, P. D.; Moharil, S. V.

2018-05-01

In the recent years solid state lighting based on LEDs has revolutionized lighting technology. LEDs have many advantages over the conventional lighting based on fluorescent and incandescent lamps such as mercury free, high conversion efficiency of electrical energy into light, long lifetime reliability and ability to use with many types of devices. LEDs have emerged as a new potentially revolutionary technology that could save up to half of energy used for lighting applications. White LEDs would be the most important light source in the future, so much so that this aspect had been highlighted by the Nobel committee during the award of 2014 Nobel Prize for Physics. Recent advancement in the fabrication of GaN chip capable of emitting in blue and near UV region paved way for fabrication of white LED lamps. Mainly there are two approaches used for preparing white emitting solid state lamp. In the first approach blue light (λ=450 nm) emitted from the InGaN LED chip is partially absorbed by the YAG:Ce3+ phosphor coated on it and re-emitted as yellow fluorescence. A white light can be generated by the combination of blue + yellow emission bands. These lamps are already available. But they are suffering from major drawback that their Colour Rendering Index (CRI) is low. In the second approach, white LEDs are made by coating near ultraviolet emitting (360 to 410nm) LED with a mixture of high efficiency red, green and blue emitting phosphors, analogous to the fluorescent lamp. This method yields lamps with better color rendition. Addition of a yellow emitting phosphor improves CRI further. However conversion efficiency is compromised to some extent. Further the cost of near UV emitting chip is very high compared to blue emitting chips. Thus cost and light output wise, near UV chips are much inferior to blue chips. Recently some rare earth activated oxynitrides, silicates, fluorides have emerged as an important family of luminescent materials for white LED application

High efficiency electrophosphorescence from bilayer organic light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Li Minghang; Lin, Ming-Te; Shepherd, Nigel D [Department of Material Science and Engineering, University of North Texas, Denton, TX (United States); Chen, Wei-Hsuan; Oswald, Iain; Omary, Mohammad [Department of Chemeistry, University of North Texas, Denton, TX (United States)

2011-09-14

An electron mobility of 2.7 x 10{sup -5} cm{sup 2} V{sup -1} s{sup -1} was measured for the phosphorescent emitter bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II)(Pt(ptp)2), which prompted its evaluation as both the emissive layer and electron transport layer in organic light emitting diodes with a simple bilayer structure. Power and external quantum efficiencies of 54.0 {+-} 0.2 lm W{sup -1} and 15.9% were obtained, which as far as we could ascertain are amongst the highest reported values for bilayer devices. We ascribe the high device efficiency to the combination of the high electron mobility, short excited-state lifetime (117 ns) and high luminescence quantum yield (60%) of the bis[3,5-bis(2-pyridyl)-1,2,4-triazolato]platinum(II). The colour temperature of the devices was 2855 K at 5 V, which places the emission in the 'warm' light spectral region.

One-Step Preparation of Blue-Emitting (La,Ca)Si3(O,N)5:Ce3+ Phosphors for High-Color Rendering White Light-Emitting Diodes

Science.gov (United States)

Yaguchi, Atsuro; Suehiro, Takayuki; Sato, Tsugio; Hirosaki, Naoto

2011-02-01

Highly phase-pure (La,Ca)Si3(O,N)5:Ce3+ blue-emitting phosphors were successfully synthesized via the one-step solid-state reaction from the system La2O3-CaO-CeO2-Si3N4. The synthesized (La,Ca)Si3(O,N)5:Ce3+ exhibits tunable blue broadband emission with the dominant wavelength of 466-479 nm and the external quantum efficiency up to ˜45% under 380 nm near-UV (NUV) excitation. Spectral simulations of the trichromatic white light-emitting diodes (LEDs) using (La,Ca)Si3(O,N)5:Ce3+ demonstrated markedly higher color rendering index Ra values of 93-95, compared to 76-90 attained by the systems using a conventional BAM:Eu2+ phosphor or InGaN blue LED. The present achievement indicates the promising applicability of (La,Ca)Si3(O,N)5:Ce3+ as a blue luminescent source for NUV-converting high-color rendering white LEDs.

High performance inkjet printed phosphorescent organic light emitting diodes based on small molecules commonly used in vacuum processes

Energy Technology Data Exchange (ETDEWEB)

Jung, Sung-Hoon [Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742 (Korea, Republic of); Kim, Jang-Joo, E-mail: jjkim@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, Seoul, 151-742 (Korea, Republic of); Kim, Hyong-Jun, E-mail: hkim@kongju.ac.kr [Department of Chemical Engineering, Kongju National University, Cheonan, 330-717 (Korea, Republic of)

2012-09-30

High efficiency phosphorescent organic light emitting diodes (OLEDs) are realized by inkjet printing based on small molecules commonly used in vacuum processes in spite of the limitation of the limited solubility. The OLEDs used the inkjet printed 5 wt.% tris(2-phenylpyridine)iridium(III) (Ir(ppy){sub 3}) doped in 4,4 Prime -Bis(carbazol-9-yl)biphenyl (CBP) as the light emitting layer on various small molecule based hole transporting layers, which are widely used in the fabrication of OLEDs by vacuum processes. The OLEDs resulted in the high power and the external quantum efficiencies of 29.9 lm/W and 11.7%, respectively, by inkjet printing the CBP:Ir(ppy){sub 3} on a 40 nm thick 4,4 Prime ,4 Double-Prime -tris(carbazol-9-yl)triphenylamine layer. The performance was very close to a vacuum deposited device with a similar structure. - Highlights: Black-Right-Pointing-Pointer Effective inkjet printed organic light emitting diode (OLED) technique is explored. Black-Right-Pointing-Pointer Solution process on commonly used hole transporting material (HTM) is demonstrated. Black-Right-Pointing-Pointer Triplet energy overlap of HTM and emitting material is the key to the performance. Black-Right-Pointing-Pointer Simple inkjet printed OLED provides the high current efficiency of 40 cd/A.

A neutron portal monitor for vehicles

International Nuclear Information System (INIS)

Coop, K.L.; Fehlau, P.E.; Atwater, H.F.

1987-01-01

We have designed and built a portal vehicle monitoring systems for detecting neutron-emitting special nuclear material (SNM) such as plutonium. Monte Carlo calculations were used to optimize the design of the 15-cm-deep x 122-cm-high x 244-cm-long detector chambers, which utilize 3 He proportional counters inside a hollow polyethylene box. Results for a variety of parametric studies, including polyethylene thickness and detector number, are described. Our experimental measurements are in good agreement with the computer calculations. The monitor's decision logic uses the Sequential Probability Ratio Test (SPRT) on Poisson distributed counting data, which is superior to other statistical tests in many applications. We performed computer simulations of the SPRT logic to determine expected false-positive decision rates. A controller unit of our design that uses this SPRT was built commercially. The cost of the complete monitoring system is similar to that of vehicle portal monitors that detect gamma rays. This new neutron monitor can serve as an addition to standard gamma-ray vehicle portals or as a stand-alone portal monitor in particular safeguards monitoring situations. The monitor is being tested at Los Alamos and is scheduled for in-plant evaluation of another DOE facility in 1987. 7 refs

High-efficiency white organic light-emitting devices with a non-doped yellow phosphorescent emissive layer

Energy Technology Data Exchange (ETDEWEB)

Zhao Juan; Yu Junsheng, E-mail: jsyu@uestc.edu.cn; Hu Xiao; Hou Menghan; Jiang Yadong

2012-03-30

Highly efficient phosphorescent white organic light-emitting devices (PHWOLEDs) with a simple structure of ITO/TAPC (40 nm)/mCP:FIrpic (20 nm, x wt.%)/bis[2-(4-tertbutylphenyl)benzothiazolato-N,C{sup 2} Prime ] iridium (acetylacetonate) (tbt){sub 2}Ir(acac) (y nm)/Bphen (30 nm)/Mg:Ag (200 nm) have been developed, by inserting a thin layer of non-doped yellow phosphorescent (tbt){sub 2}Ir(acac) between doped blue emitting layer (EML) and electron transporting layer. By changing the doping concentration of the blue EML and the thickness of the non-doped yellow EML, a PHWOLED comprised of higher blue doping concentration and thinner yellow EML achieves a high current efficiency of 31.7 cd/A and Commission Internationale de l'Eclairage coordinates of (0.33, 0.41) at a luminance of 3000 cd/m{sup 2} could be observed. - Highlights: Black-Right-Pointing-Pointer We introduce a simplified architecture for phosphorescent white organic light-emitting device. Black-Right-Pointing-Pointer The key concept of device fabrication is combination of doped blue emissive layer (EML) with non-doped ultra-thin yellow EML. Black-Right-Pointing-Pointer Doping concentration of the blue EML and thickness of the yellow EML are sequentially adjusted. Black-Right-Pointing-Pointer High device performance is achieved due to improved charge carrier balance as well as two parallel emission mechanisms in the EMLs.

High-resolution mapping of motor vehicle carbon dioxide emissions

Science.gov (United States)

McDonald, Brian C.; McBride, Zoe C.; Martin, Elliot W.; Harley, Robert A.

2014-05-01

A fuel-based inventory for vehicle emissions is presented for carbon dioxide (CO2) and mapped at various spatial resolutions (10 km, 4 km, 1 km, and 500 m) using fuel sales and traffic count data. The mapping is done separately for gasoline-powered vehicles and heavy-duty diesel trucks. Emission estimates from this study are compared with the Emissions Database for Global Atmospheric Research (EDGAR) and VULCAN. All three inventories agree at the national level within 5%. EDGAR uses road density as a surrogate to apportion vehicle emissions, which leads to 20-80% overestimates of on-road CO2 emissions in the largest U.S. cities. High-resolution emission maps are presented for Los Angeles, New York City, San Francisco-San Jose, Houston, and Dallas-Fort Worth. Sharp emission gradients that exist near major highways are not apparent when emissions are mapped at 10 km resolution. High CO2 emission fluxes over highways become apparent at grid resolutions of 1 km and finer. Temporal variations in vehicle emissions are characterized using extensive day- and time-specific traffic count data and are described over diurnal, day of week, and seasonal time scales. Clear differences are observed when comparing light- and heavy-duty vehicle traffic patterns and comparing urban and rural areas. Decadal emission trends were analyzed from 2000 to 2007 when traffic volumes were increasing and a more recent period (2007-2010) when traffic volumes declined due to recession. We found large nonuniform changes in on-road CO2 emissions over a period of 5 years, highlighting the importance of timely updates to motor vehicle emission inventories.

High color rendering index white organic light-emitting diode using levofloxacin as blue emitter

Science.gov (United States)

Miao, Yan-Qin; Gao, Zhi-Xiang; Zhang, Ai-Qin; Li, Yuan-Hao; Wang, Hua; Jia, Hu-Sheng; Liu, Xu-Guang; Tsuboi, Taijuf

2015-05-01

Levofloxacin (LOFX), which is well-known as an antibiotic medicament, was shown to be useful as a 452-nm blue emitter for white organic light-emitting diodes (OLEDs). In this paper, the fabricated white OLED contains a 452-nm blue emitting layer (thickness of 30 nm) with 1 wt% LOFX doped in CBP (4,4’-bis(carbazol-9-yl)biphenyl) host and a 584-nm orange emitting layer (thickness of 10 nm) with 0.8 wt% DCJTB (4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran) doped in CBP, which are separated by a 20-nm-thick buffer layer of TPBi (2,2’,2”-(benzene-1,3,5-triyl)-tri(1-phenyl-1H-benzimidazole). A high color rendering index (CRI) of 84.5 and CIE chromaticity coordinates of (0.33, 0.32), which is close to ideal white emission CIE (0.333, 0.333), are obtained at a bias voltage of 14 V. Taking into account that LOFX is less expensive and the synthesis and purification technologies of LOFX are mature, these results indicate that blue fluorescence emitting LOFX is useful for applications to white OLEDs although the maximum current efficiency and luminance are not high. The present paper is expected to become a milestone to using medical drug materials for OLEDs. Project supported by the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No. NCET-13-0927), the International Science & Technology Cooperation Program of China (Grant No. 2012DFR50460), the National Natural Science Foundation of China (Grant Nos. 21101111 and 61274056), and the Shanxi Provincial Key Innovative Research Team in Science and Technology, China (Grant No. 2012041011).

High-energy terahertz wave parametric oscillator with a surface-emitted ring-cavity configuration.

Science.gov (United States)

Yang, Zhen; Wang, Yuye; Xu, Degang; Xu, Wentao; Duan, Pan; Yan, Chao; Tang, Longhuang; Yao, Jianquan

2016-05-15

A surface-emitted ring-cavity terahertz (THz) wave parametric oscillator has been demonstrated for high-energy THz output and fast frequency tuning in a wide frequency range. Through the special optical design with a galvano-optical scanner and four-mirror ring-cavity structure, the maximum THz wave output energy of 12.9 μJ/pulse is achieved at 1.359 THz under the pump energy of 172.8 mJ. The fast THz frequency tuning in the range of 0.7-2.8 THz can be accessed with the step response of 600 μs. Moreover, the maximum THz wave output energy from this configuration is 3.29 times as large as that obtained from the conventional surface-emitted THz wave parametric oscillator with the same experimental conditions.

U.S. regional greenhouse gas emissions analysis comparing highly resolved vehicle miles traveled and CO2 emissions: mitigation implications and their effect on atmospheric measurements

Science.gov (United States)

Mendoza, D. L.; Gurney, K. R.

2010-12-01

Carbon dioxide (CO2) is the most abundant anthropogenic greenhouse gas and projections of fossil fuel energy demand show CO2 concentrations increasing indefinitely into the future. After electricity production, the transportation sector is the second largest CO2 emitting economic sector in the United States, accounting for 32.3% of the total U.S. emissions in 2002. Over 80% of the transport sector is composed of onroad emissions, with the remainder shared by the nonroad, aircraft, railroad, and commercial marine vessel transportation. In order to construct effective mitigation policy for the onroad transportation sector and more accurately predict CO2 emissions for use in transport models and atmospheric measurements, analysis must incorporate the three components that determine the CO2 onroad transport emissions: vehicle fleet composition, average speed of travel, and emissions regulation strategies. Studies to date, however, have either focused on one of these three components, have been only completed at the national scale, or have not explicitly represented CO2 emissions instead relying on the use of vehicle miles traveled (VMT) as an emissions proxy. National-level projections of VMT growth is not sufficient to highlight regional differences in CO2 emissions growth due to the heterogeneity of vehicle fleet and each state’s road network which determines the speed of travel of vehicles. We examine how an analysis based on direct CO2 emissions and an analysis based on VMT differ in terms of their emissions and mitigation implications highlighting potential biases introduced by the VMT-based approach. This analysis is performed at the US state level and results are disaggregated by road and vehicle classification. We utilize the results of the Vulcan fossil fuel CO2 emissions inventory which quantified emissions for the year 2002 across all economic sectors in the US at high resolution. We perform this comparison by fuel type,12 road types, and 12 vehicle types

Radiation emitting devices regulations

International Nuclear Information System (INIS)

1970-01-01

The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

Stereo-vision-based cooperative-vehicle positioning using OCC and neural networks

Science.gov (United States)

Ifthekhar, Md. Shareef; Saha, Nirzhar; Jang, Yeong Min

2015-10-01

Vehicle positioning has been subjected to extensive research regarding driving safety measures and assistance as well as autonomous navigation. The most common positioning technique used in automotive positioning is the global positioning system (GPS). However, GPS is not reliably accurate because of signal blockage caused by high-rise buildings. In addition, GPS is error prone when a vehicle is inside a tunnel. Moreover, GPS and other radio-frequency-based approaches cannot provide orientation information or the position of neighboring vehicles. In this study, we propose a cooperative-vehicle positioning (CVP) technique by using the newly developed optical camera communications (OCC). The OCC technique utilizes image sensors and cameras to receive and decode light-modulated information from light-emitting diodes (LEDs). A vehicle equipped with an OCC transceiver can receive positioning and other information such as speed, lane change, driver's condition, etc., through optical wireless links of neighboring vehicles. Thus, the target vehicle position that is too far away to establish an OCC link can be determined by a computer-vision-based technique combined with the cooperation of neighboring vehicles. In addition, we have devised a back-propagation (BP) neural-network learning method for positioning and range estimation for CVP. The proposed neural-network-based technique can estimate target vehicle position from only two image points of target vehicles using stereo vision. For this, we use rear LEDs on target vehicles as image points. We show from simulation results that our neural-network-based method achieves better accuracy than that of the computer-vision method.

EXPERIENCES WITH ACQUIRING HIGHLY REDUNDANT SPATIAL DATA TO SUPPORT DRIVERLESS VEHICLE TECHNOLOGIES

Directory of Open Access Journals (Sweden)

Z. Koppanyi

2018-05-01

Full Text Available As vehicle technology is moving towards higher autonomy, the demand for highly accurate geospatial data is rapidly increasing, as accurate maps have a huge potential of increasing safety. In particular, high definition 3D maps, including road topography and infrastructure, as well as city models along the transportation corridors represent the necessary support for driverless vehicles. In this effort, a vehicle equipped with high-, medium- and low-resolution active and passive cameras acquired data in a typical traffic environment, represented here by the OSU campus, where GPS/GNSS data are available along with other navigation sensor data streams. The data streams can be used for two purposes. First, high-definition 3D maps can be created by integrating all the sensory data, and Data Analytics/Big Data methods can be tested for automatic object space reconstruction. Second, the data streams can support algorithmic research for driverless vehicle technologies, including object avoidance, navigation/positioning, detecting pedestrians and bicyclists, etc. Crucial cross-performance analyses on map database resolution and accuracy with respect to sensor performance metrics to achieve economic solution for accurate driverless vehicle positioning can be derived. These, in turn, could provide essential information on optimizing the choice of geospatial map databases and sensors’ quality to support driverless vehicle technologies. The paper reviews the data acquisition and primary data processing challenges and performance results.

Experiences with Acquiring Highly Redundant Spatial Data to Support Driverless Vehicle Technologies

Science.gov (United States)

Koppanyi, Z.; Toth, C. K.

2018-05-01

As vehicle technology is moving towards higher autonomy, the demand for highly accurate geospatial data is rapidly increasing, as accurate maps have a huge potential of increasing safety. In particular, high definition 3D maps, including road topography and infrastructure, as well as city models along the transportation corridors represent the necessary support for driverless vehicles. In this effort, a vehicle equipped with high-, medium- and low-resolution active and passive cameras acquired data in a typical traffic environment, represented here by the OSU campus, where GPS/GNSS data are available along with other navigation sensor data streams. The data streams can be used for two purposes. First, high-definition 3D maps can be created by integrating all the sensory data, and Data Analytics/Big Data methods can be tested for automatic object space reconstruction. Second, the data streams can support algorithmic research for driverless vehicle technologies, including object avoidance, navigation/positioning, detecting pedestrians and bicyclists, etc. Crucial cross-performance analyses on map database resolution and accuracy with respect to sensor performance metrics to achieve economic solution for accurate driverless vehicle positioning can be derived. These, in turn, could provide essential information on optimizing the choice of geospatial map databases and sensors' quality to support driverless vehicle technologies. The paper reviews the data acquisition and primary data processing challenges and performance results.

Highly Efficient White Organic Light Emitting Diodes Using New Blue Fluorescence Emitter.

Science.gov (United States)

Kim, Seungho; Kim, Beomjin; Lee, Jaehyun; Yu, Young-Jun; Park, Jongwook

2015-07-01

Two different emitting compounds, 1-[1,1';3',1"]Terphenyl-5'-yl-6-(10-[1,1';3',1"]terpheny-5'-yl- anthracen-9-yl)-pyrene (TP-AP-TP) and Poly-phenylene vinylene derivative (PDY 132) were used to white OLED device. By incorporating adjacent blue and yellow emitting layers in a multi-layered structure, highly efficient white emission has been attained. The device was fabricated with a hybrid configuration structure: ITO/PEDOT (40 nm)/PDY-132 (8-50 nm)/ NPB (10 nm)/TP-AP-TP (30 nm)/Alq3 (20 nm)/LiF (1 nm)/Al (200 nm). After fixing TP-AP-TP thickness of 30 nm by evaporation, PDY-132 thickness varied with 8, 15, 35, and 50 nm by spin coating in device. The luminance efficiency of the white devices at 10 mA/cm2 were 2.93 cd/A-6.55 cd/A. One of white devices showed 6.55 cd/A and white color of (0.290, 0.331).

A method for measuring particle number emissions from vehicles driving on the road.

Science.gov (United States)

Shi, J P; Harrison, R M; Evans, D E; Alam, A; Barnes, C; Carter, G

2002-01-01

Earlier research has demonstrated that the conditions of dilution of engine exhaust gases profoundly influence the size distribution and total number of particles emitted. Since real world dilution conditions are variable and therefore difficult to simulate, this research has sought to develop and validate a method for measuring particle number emissions from vehicles driving past on a road. This has been achieved successfully using carbon dioxide as a tracer of exhaust gas dilution. By subsequent adjustment of data to a constant dilution factor, it is possible to compare emissions from different vehicles using different technologies and fuels based upon real world emission data. Whilst further optimisation of the technique, especially in terms of matching the instrument response times is desirable, the measurements offer useful insights into emissions from gasoline and diesel vehicles, and the substantial proportion of particles emitted in the 3-7 nanometre size range.

Highly Skilled Autonomous Vehicles

OpenAIRE

Manuel Acosta Reche; Stratis Kanarachos; Mike V Blundell

2017-01-01

Recent research suggests that collision mitigation on low grip surfaces might require autonomous vehicles to execute maneuvers such as drift, trail braking or Scandinavian flick. In order to achieve this it is necessary to perceive the vehicle states and their interaction with the environment, and use this information to determine the chassis limits. A first look at the virtual automotive sensing problem is provided, followed by a description of Rally driving modeling approaches. Finally, a c...

ORNL shielded facilities capable of remote handling of highly radioactive beta--gamma emitting materials

International Nuclear Information System (INIS)

Whitson, W.R.

1977-09-01

A survey of ORNL facilities having adequate shielding and containment for the remote handling of experimental quantities of highly radioactive beta-gamma emitting materials is summarized. Portions of the detailed descriptions of these facilities previously published in ORNL/TM-1268 are still valid and are repeated

Magnetic suspension and guidance of high speed vehicles. Final report

Energy Technology Data Exchange (ETDEWEB)

Alston, I A; Clark, J M; Hayden, J T

1972-12-01

Technical and economical assessments of magnetic suspensions for high speed vehicles and transport systems are reported. In these suspensions the suspending magnet takes the form of a powerful superconducting electromagnet that induces currents while it moves over conducting sheets or loops. A number of vehicle track designs are evaluated for operating cost effectiveness. It is shown that propulsion systems using power collected from the track are more expensive than those using power generated onboard the vehicle, and that the conducting sheet suspension is slightly more expensive than the null flux suspension.

78 FR 16051 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

Science.gov (United States)

2013-03-13

..., without the need for obtaining a waiver. In order to take advantage of high cant deficiency operations and... attention. In addition, to improve the process for analyzing data while vehicles are negotiating spiral... the last few decades, computer models of rail vehicles interacting with track have become practical...

High-Fidelity Computational Aerodynamics of Multi-Rotor Unmanned Aerial Vehicles

Science.gov (United States)

Ventura Diaz, Patricia; Yoon, Seokkwan

2018-01-01

High-fidelity Computational Fluid Dynamics (CFD) simulations have been carried out for several multi-rotor Unmanned Aerial Vehicles (UAVs). Three vehicles have been studied: the classic quadcopter DJI Phantom 3, an unconventional quadcopter specialized for forward flight, the SUI Endurance, and an innovative concept for Urban Air Mobility (UAM), the Elytron 4S UAV. The three-dimensional unsteady Navier-Stokes equations are solved on overset grids using high-order accurate schemes, dual-time stepping, and a hybrid turbulence model. The DJI Phantom 3 is simulated with different rotors and with both a simplified airframe and the real airframe including landing gear and a camera. The effects of weather are studied for the DJI Phantom 3 quadcopter in hover. The SUI En- durance original design is compared in forward flight to a new configuration conceived by the authors, the hybrid configuration, which gives a large improvement in forward thrust. The Elytron 4S UAV is simulated in helicopter mode and in airplane mode. Understanding the complex flows in multi-rotor vehicles will help design quieter, safer, and more efficient future drones and UAM vehicles.

Astigmatism-free high-brightness 1060 nm edge-emitting lasers with narrow circular beam profile.

Science.gov (United States)

Miah, Md Jarez; Kalosha, Vladimir P; Bimberg, Dieter; Pohl, Johannes; Weyers, Markus

2016-12-26

1060 nm high-brightness vertical broad-area edge-emitting lasers providing anastigmatic high optical power into a narrow circular beam profile are demonstrated. Ridge-waveguide (RW) lasers yield record 2.2 W single-transverse mode power in the 1060-nm wavelength range under continuous-wave (cw) operation at room temperature with excellent beam quality factor M2 ≤ 2. Independent of operating current the astigmatism is only 2.5 µm. 3 mm long broad-area (BA) lasers produce a θvert as narrow as 9° full width at half maximum, which agrees well with our simulation results, being insensitive to drive current. 5 mm long BA lasers deliver highest ever reported cw 12 W multimode output power among lasers showing θvert <10° in the 1060-nm wavelength range. The emitted laser beams from both RW and BA lasers show a perfect circular shape with ≤10° divergence angle at record 2.1 W and 4.2 W cw-mode output power, respectively.

Open tube guideway for high speed air cushioned vehicles

Science.gov (United States)

Goering, R. S. (Inventor)

1974-01-01

This invention is a tubular shaped guideway for high-speed air-cushioned supported vehicles. The tubular guideway is split and separated such that the sides of the guideway are open. The upper portion of the tubular guideway is supported above the lower portion by truss-like structural members. The lower portion of the tubular guideway may be supported by the terrain over which the vehicle travels, on pedestals or some similar structure.

High-power light-emitting diode based facility for plant cultivation

Energy Technology Data Exchange (ETDEWEB)

Tamulaitis, G [Institute of Materials Science and Applied Research, Vilnius University, Sauletekio al. 9-III, LT-10222 Vilnius (Lithuania); Duchovskis, P [Lithuanian Institute of Horticulture, Babtai, LT-54333 Kaunas District (Lithuania); Bliznikas, Z [Institute of Materials Science and Applied Research, Vilnius University, Sauletekio al. 9-III, LT-10222 Vilnius (Lithuania); Breive, K [Institute of Materials Science and Applied Research, Vilnius University, Sauletekio al. 9-III, LT-10222 Vilnius (Lithuania); Ulinskaite, R [Lithuanian Institute of Horticulture, Babtai, LT-54333 Kaunas District (Lithuania); Brazaityte, A [Lithuanian Institute of Horticulture, Babtai, LT-54333 Kaunas District (Lithuania); Novickovas, A [Institute of Materials Science and Applied Research, Vilnius University, Sauletekio al. 9-III, LT-10222 Vilnius (Lithuania); Zukauskas, A [Institute of Materials Science and Applied Research, Vilnius University, Sauletekio al. 9-III, LT-10222 Vilnius (Lithuania)

2005-09-07

Based on perspectives of the development of semiconductor materials systems for high-power light-emitting diodes (LEDs), an illumination facility for greenhouse plant cultivation was designed with the dominating 640 nm photosynthetically active component delivered by AlGaInP LEDs and supplementary components from AlGaN (photothropic action, 455 nm) and AlGaAs (photosynthetic 660 nm and photomorphogenetic 735 nm) LEDs. Photosynthesis intensity, photosynthetic productivity and growth morphology as well as chlorophyll and phytohormone concentrations were investigated in radish and lettuce grown in phytotron chambers under the LED-based illuminators and under high-pressure sodium (HPS) lamps with an equivalent photon flux density. Advantages of the high-power LED-based illuminators over conventional HPS lamps, applicability of AlGaInP LEDs for photosynthesis and control of plant growth by circadian manipulation of a relatively weak far-red component were demonstrated.

High-power light-emitting diode based facility for plant cultivation

International Nuclear Information System (INIS)

Tamulaitis, G; Duchovskis, P; Bliznikas, Z; Breive, K; Ulinskaite, R; Brazaityte, A; Novickovas, A; Zukauskas, A

2005-01-01

Based on perspectives of the development of semiconductor materials systems for high-power light-emitting diodes (LEDs), an illumination facility for greenhouse plant cultivation was designed with the dominating 640 nm photosynthetically active component delivered by AlGaInP LEDs and supplementary components from AlGaN (photothropic action, 455 nm) and AlGaAs (photosynthetic 660 nm and photomorphogenetic 735 nm) LEDs. Photosynthesis intensity, photosynthetic productivity and growth morphology as well as chlorophyll and phytohormone concentrations were investigated in radish and lettuce grown in phytotron chambers under the LED-based illuminators and under high-pressure sodium (HPS) lamps with an equivalent photon flux density. Advantages of the high-power LED-based illuminators over conventional HPS lamps, applicability of AlGaInP LEDs for photosynthesis and control of plant growth by circadian manipulation of a relatively weak far-red component were demonstrated

GASOLINE VEHICLE EXHAUST PARTICLE SAMPLING STUDY

Energy Technology Data Exchange (ETDEWEB)

Kittelson, D; Watts, W; Johnson, J; Zarling, D Schauer,J Kasper, K; Baltensperger, U; Burtscher, H

2003-08-24

The University of Minnesota collaborated with the Paul Scherrer Institute, the University of Wisconsin (UWI) and Ricardo, Inc to physically and chemically characterize the exhaust plume from recruited gasoline spark ignition (SI) vehicles. The project objectives were: (1) Measure representative particle size distributions from a set of on-road SI vehicles and compare these data to similar data collected on a small subset of light-duty gasoline vehicles tested on a chassis dynamometer with a dilution tunnel using the Unified Drive Cycle, at both room temperature (cold start) and 0 C (cold-cold start). (2) Compare data collected from SI vehicles to similar data collected from Diesel engines during the Coordinating Research Council E-43 project. (3) Characterize on-road aerosol during mixed midweek traffic and Sunday midday periods and determine fleet-specific emission rates. (4) Characterize bulk- and size-segregated chemical composition of the particulate matter (PM) emitted in the exhaust from the gasoline vehicles. Particle number concentrations and size distributions are strongly influenced by dilution and sampling conditions. Laboratory methods were evaluated to dilute SI exhaust in a way that would produce size distributions that were similar to those measured during laboratory experiments. Size fractionated samples were collected for chemical analysis using a nano-microorifice uniform deposit impactor (nano-MOUDI). In addition, bulk samples were collected and analyzed. A mixture of low, mid and high mileage vehicles were recruited for testing during the study. Under steady highway cruise conditions a significant particle signature above background was not measured, but during hard accelerations number size distributions for the test fleet were similar to modern heavy-duty Diesel vehicles. Number emissions were much higher at high speed and during cold-cold starts. Fuel specific number emissions range from 1012 to 3 x 1016 particles/kg fuel. A simple

In silico evaluation of highly efficient organic light-emitting materials

Science.gov (United States)

Kwak, H. Shaun; Giesen, David J.; Hughes, Thomas F.; Goldberg, Alexander; Cao, Yixiang; Gavartin, Jacob; Dixon, Steve; Halls, Mathew D.

2016-09-01

Design and development of highly efficient organic and organometallic dopants is one of the central challenges in the organic light-emitting diodes (OLEDs) technology. Recent advances in the computational materials science have made it possible to apply computer-aided evaluation and screening framework directly to the design space of organic lightemitting diodes (OLEDs). In this work, we will showcase two major components of the latest in silico framework for development of organometallic phosphorescent dopants - (1) rapid screening of dopants by machine-learned quantum mechanical models and (2) phosphorescence lifetime predictions with spin-orbit coupled calculations (SOC-TDDFT). The combined work of virtual screening and evaluation would significantly widen the design space for highly efficient phosphorescent dopants with unbiased measures to evaluate performance of the materials from first principles.

Technology Improvement for the High Reliability LM-2F Launch Vehicle

Institute of Scientific and Technical Information of China (English)

QIN Tong; RONG Yi; ZHENG Liwei; ZHANG Zhi

2017-01-01

The Long March 2F (LM-2F) launch vehicle,the only launch vehicle designed for manned space flight in China,successfully launched the Tiangong 2 space laboratory and the Shenzhou ll manned spaceship into orbits in 2016 respectively.In this study,it introduces the technological improvements for enhancing the reliability of the LM-2F launch vehicle in the aspects of general technology,control system,manufacture and ground support system.The LM2F launch vehicle will continue to provide more contributions to the Chinese Space Station Project with its high reliability and 100％ success rate.

The present status of the high temperature superconducting Maglev vehicle in China

International Nuclear Information System (INIS)

Wang, J S; Wang, S Y; Zeng, Y W; Deng, C Y; Ren, Z Y; Wang, X R; Song, H H; Wang, X Z; Zheng, J; Zhao, Y

2005-01-01

Since the first successful running of the people-carrying high temperature superconducting (HTS) Maglev test vehicle on 31 December 2000, about 27,000 people have taken it, and the accumulated running distance is about 400 km. The levitation force of the onboard HTS equipment is measured periodically, and new experimental results measured on 5 March 2003 show that the performance of the onboard HTS Maglev equipment is almost the same as that of two years ago. Experimental results indicate that the long-term stability of the HTS Maglev vehicle is good. This further proves the feasibility of the HTS Maglev vehicle for practical transportation. It is worth mentioning that all the results are measured at a low speed; however, investigations of the dynamic performance of the HTS Maglev vehicle at high speed are necessary for practical application. Research on the dynamic performance of the HTS Maglev vehicle is ongoing

The present status of the high temperature superconducting Maglev vehicle in China

Energy Technology Data Exchange (ETDEWEB)

Wang, J S; Wang, S Y; Zeng, Y W; Deng, C Y; Ren, Z Y; Wang, X R; Song, H H; Wang, X Z; Zheng, J; Zhao, Y [Superconductivity R and D Center, Mail Stop: 152, Southwest Jiaotong University, Chengdu 610031, Sichuan (China)

2005-02-01

Since the first successful running of the people-carrying high temperature superconducting (HTS) Maglev test vehicle on 31 December 2000, about 27,000 people have taken it, and the accumulated running distance is about 400 km. The levitation force of the onboard HTS equipment is measured periodically, and new experimental results measured on 5 March 2003 show that the performance of the onboard HTS Maglev equipment is almost the same as that of two years ago. Experimental results indicate that the long-term stability of the HTS Maglev vehicle is good. This further proves the feasibility of the HTS Maglev vehicle for practical transportation. It is worth mentioning that all the results are measured at a low speed; however, investigations of the dynamic performance of the HTS Maglev vehicle at high speed are necessary for practical application. Research on the dynamic performance of the HTS Maglev vehicle is ongoing.

Characterization of primary organic aerosol emissions from meat cooking, trash burning, and motor vehicles with high-resolution aerosol mass spectrometry and comparison with ambient and chamber observations.

Science.gov (United States)

Mohr, Claudia; Huffman, Alex; Cubison, Michael J; Aiken, Allison C; Docherty, Kenneth S; Kimmel, Joel R; Ulbrich, Ingrid M; Hannigan, Michael; Jimenez, Jose L

2009-04-01

Organic aerosol (OA) emissions from motor vehicles, meat-cooking and trash burning are analyzed here using a high-resolution aerosol mass spectrometer (AMS). High resolution data show that aerosols emitted by combustion engines and plastic burning are dominated by hydrocarbon-like organic compounds. Meat cooking and especially paper burning emissions contain significant fractions of oxygenated organic compounds; however, their unit-resolution mass spectral signatures are very similar to those from ambient hydrocarbon-like OA, and very different from the mass spectra of ambient secondary or oxygenated OA (OOA). Thus, primary OA from these sources is unlikelyto be a significant direct source of ambient OOA. There are significant differences in high-resolution tracer m/zs that may be useful for differentiating some of these sources. Unlike in most ambient spectra, all of these sources have low total m/z 44 and this signal is not dominated by the CO2+ ion. All sources have high m/z 57, which is low during high OOA ambient periods. Spectra from paper burning are similar to some types of biomass burning OA, with elevated m/z 60. Meat cooking aerosols also have slightly elevated m/z 60, whereas motor vehicle emissions have very low signal at this m/z.

Mars Ascent Vehicle Needs Technology Development with a Focus on High Propellant Fractions

Science.gov (United States)

Whitehead, J. C.

2018-04-01

Launching from Mars to orbit requires a miniature launch vehicle, beyond any known spacecraft propulsion. The Mars Ascent Vehicle (MAV) needs an unusually high propellant mass fraction. MAV mass has high leverage for the cost of Mars Sample Return.

Unmanned Aerial Vehicles: Progress Toward Meeting High Altitude Endurance Aircraft Price Goals

National Research Council Canada - National Science Library

1998-01-01

...) High Altitude Endurance (HAE) Unmanned Aerial Vehicle (UAV) program to determine whether the average flyaway cost for the Global Hawk and DarkStar HAE alr vehicles will be within DOD's cost goal...

Recycled Thermal Energy from High Power Light Emitting Diode Light Source.

Science.gov (United States)

Ji, Jae-Hoon; Jo, GaeHun; Ha, Jae-Geun; Koo, Sang-Mo; Kamiko, Masao; Hong, JunHee; Koh, Jung-Hyuk

2018-09-01

In this research, the recycled electrical energy from wasted thermal energy in high power Light Emitting Diode (LED) system will be investigated. The luminous efficiency of lights has been improved in recent years by employing the high power LED system, therefore energy efficiency was improved compared with that of typical lighting sources. To increase energy efficiency of high power LED system further, wasted thermal energy should be re-considered. Therefore, wasted thermal energy was collected and re-used them as electrical energy. The increased electrical efficiency of high power LED devices was accomplished by considering the recycled heat energy, which is wasted thermal energy from the LED. In this work, increased electrical efficiency will be considered and investigated by employing the high power LED system, which has high thermal loss during the operating time. For this research, well designed thermoelement with heat radiation system was employed to enhance the collecting thermal energy from the LED system, and then convert it as recycled electrical energy.

Extracting Lane Geometry and Topology Information from Vehicle Fleet Trajectories in Complex Urban Scenarios Using a Reversible Jump Mcmc Method

Science.gov (United States)

Roeth, O.; Zaum, D.; Brenner, C.

2017-05-01

Highly automated driving (HAD) requires maps not only of high spatial precision but also of yet unprecedented actuality. Traditionally small highly specialized fleets of measurement vehicles are used to generate such maps. Nevertheless, for achieving city-wide or even nation-wide coverage, automated map update mechanisms based on very large vehicle fleet data gain importance since highly frequent measurements are only to be obtained using such an approach. Furthermore, the processing of imprecise mass data in contrast to few dedicated highly accurate measurements calls for a high degree of automation. We present a method for the generation of lane-accurate road network maps from vehicle trajectory data (GPS or better). Our approach therefore allows for exploiting today's connected vehicle fleets for the generation of HAD maps. The presented algorithm is based on elementary building blocks which guarantees useful lane models and uses a Reversible Jump Markov chain Monte Carlo method to explore the models parameters in order to reconstruct the one most likely emitting the input data. The approach is applied to a challenging urban real-world scenario of different trajectory accuracy levels and is evaluated against a LIDAR-based ground truth map.

Emissions of hydrogen cyanide from on-road gasoline and diesel vehicles

Science.gov (United States)

Moussa, Samar G.; Leithead, Amy; Li, Shao-Meng; Chan, Tak W.; Wentzell, Jeremy J. B.; Stroud, Craig; Zhang, Junhua; Lee, Patrick; Lu, Gang; Brook, Jeffery R.; Hayden, Katherine; Narayan, Julie; Liggio, John

2016-04-01

Hydrogen cyanide (HCN) is considered a marker for biomass burning emissions and is a component of vehicle exhaust. Despite its potential health impacts, vehicular HCN emissions estimates and their contribution to regional budgets are highly uncertain. In the current study, Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) was used to measure HCN emission factors from the exhaust of individual diesel, biodiesel and gasoline vehicles. Laboratory emissions data as a function of fuel type and driving mode were combined with ambient measurement data and model predictions. The results indicate that gasoline vehicles have the highest emissions of HCN (relative to diesel fuel) and that biodiesel fuel has the potential to significantly reduce HCN emissions even at realistic 5% blend levels. The data further demonstrate that gasoline direct injection (GDI) engines emit more HCN than their port fuel injection (PFI) counterparts, suggesting that the expected full transition of vehicle fleets to GDI will increase HCN emissions. Ambient measurements of HCN in a traffic dominated area of Toronto, Canada were strongly correlated to vehicle emission markers and consistent with regional air quality model predictions of ambient air HCN, indicating that vehicle emissions of HCN are the dominant source of exposure in urban areas. The results further indicate that additional work is required to quantify HCN emissions from the modern vehicle fleet, particularly in light of continuously changing engine, fuel and after-treatment technologies.

Highly stable CsPbBr3 quantum dots coated with alkyl phosphate for white light-emitting diodes.

Science.gov (United States)

Xuan, Tongtong; Yang, Xianfeng; Lou, Sunqi; Huang, Junjian; Liu, Yong; Yu, Jinbo; Li, Huili; Wong, Ka-Leung; Wang, Chengxin; Wang, Jing

2017-10-19

Inorganic halide perovskite quantum dots (QDs) suffer from problems related to poor water stability and poor thermal stability. Here we developed a simple strategy to synthesize alkyl phosphate (TDPA) coated CsPbBr 3 QDs by using 1-tetradecylphosphonic acid both as the ligand for the CsPbBr 3 QDs and as the precursor for the formation of alkyl phosphate. These QDs not only retain a high photoluminescence quantum yield (PLQY, 68%) and narrow band emission (FHWM ∼ 22 nm) but also exhibit high stability against water and heat. The relative PL intensity of the QDs was maintained at 75% or 59% after being dispersed in water for 5 h or heated to 375 K (100 °C), respectively. Finally, white light-emitting diodes (WLEDs) with a high luminous efficiency of 63 lm W -1 and a wide color gamut (122% of NTSC) were fabricated by using green-emitting CsPbBr 3 /TDPA QDs and red-emitting K 2 SiF 6 :Mn 4+ phosphors as color converters. The luminous efficiency of the WLEDs remained at 90% after working under a relative humidity (RH) of 60% for 15 h, thereby showing promise for use as backlight devices in LCDs.

Light-Emitting Pickles

Science.gov (United States)

Vollmer, M.; Mollmann, K-P.

2015-01-01

We present experiments giving new insights into the classical light-emitting pickle experiment. In particular, measurements of the spectra and temperatures, as well as high-speed recordings, reveal that light emission is connected to the polarity of the electrodes and the presence of hydrogen.

Quantifying displaced carbon dioxide emissions from electric vehicles in Ireland

OpenAIRE

Foley, Aoife M.; Leahy, Paul G.; McKeogh, Eamon J.; Ó Gallachóir, Brian P.

2010-01-01

Under EU Directive 2009/28/EC on Renewable Energy each Member State is mandated to ensure that 10% of transport energy (excluding aviation and marine transport) comes from renewable sources by 2020. The Irish Government intends to achieve this target with a number of policies including an increase in the use of biofuels in transport by 3% by 2010 and ensuring that 10% of all vehicles in the transport fleet are powered by electricity by 2020. Electric vehicles (EVs) do not emit exh...

The importance of high vehicle power for passenger car emissions

Science.gov (United States)

Carslaw, David C.; Williams, Martin L.; Tate, James E.; Beevers, Sean D.

2013-04-01

In this paper we use a quantile regression technique to explore the emissions characteristics of petrol and diesel passenger cars to reveal the importance of high vehicle power on exhaust emissions. A large database of ≈67,000 passenger cars from vehicle emission remote sensing data was used from surveys from several campaigns around the UK. Most previous remote sensing studies have focused on presenting mean emission estimates by vehicle type over time. However, as shown in the current work, considerably more insight can be gained into vehicle emission characteristics if techniques are used that can describe and model the full distribution of vehicle emissions as a function of important explanatory variables. For post-2000 model year (Euro 3-5) diesel cars it is shown that there is a strong dependence of vehicle specific power for emissions of NOx that was absent in earlier models and is absent for other pollutants such as CO, hydrocarbons and 'smoke'. Furthermore, we also find a stronger dependence on vehicle specific power for older catalyst-equipped petrol vehicles (Euro 1/2) on emissions of NOx that is less important for other emissions such as CO and hydrocarbons. Moreover, it is shown that while the rated maximum power output of petrol cars has remained almost constant over the past 15-20 years, the power output from diesel cars has increased markedly by about 50%. These results suggest that changes to vehicle technology, driving conditions and driver behaviour have become more important determinants of passenger car NOx emissions in recent years and may help explain why urban ambient concentrations of NOx have not decreased as much as anticipated.

A Lane-Level LBS System for Vehicle Network with High-Precision BDS/GPS Positioning

Science.gov (United States)

Guo, Chi; Guo, Wenfei; Cao, Guangyi; Dong, Hongbo

2015-01-01

In recent years, research on vehicle network location service has begun to focus on its intelligence and precision. The accuracy of space-time information has become a core factor for vehicle network systems in a mobile environment. However, difficulties persist in vehicle satellite positioning since deficiencies in the provision of high-quality space-time references greatly limit the development and application of vehicle networks. In this paper, we propose a high-precision-based vehicle network location service to solve this problem. The major components of this study include the following: (1) application of wide-area precise positioning technology to the vehicle network system. An adaptive correction message broadcast protocol is designed to satisfy the requirements for large-scale target precise positioning in the mobile Internet environment; (2) development of a concurrence service system with a flexible virtual expansion architecture to guarantee reliable data interaction between vehicles and the background; (3) verification of the positioning precision and service quality in the urban environment. Based on this high-precision positioning service platform, a lane-level location service is designed to solve a typical traffic safety problem. PMID:25755665

Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

International Nuclear Information System (INIS)

Ganter, R.; Bakker, R.J.; Gough, C.; Paraliev, M.; Pedrozzi, M.; Le Pimpec, F.; Rivkin, L.; Wrulich, A.

2006-01-01

In order to find electron sources with low thermal emittance, cathodes based on single tip field emitter are investigated. Maximum peak current, measured from single tip in ZrC with a typical apex radius around 1 μm, are presented. Voltage pulses of 2 ns duration and up to 50 kV amplitude lead to field emission current up to 470 mA from one ZrC tip. Combination of high applied electric field with laser illumination gives the possibility to modulate the emission with laser pulses. Nanoseconds current pulses have been emitted with laser pulses at 1064 nm illuminating a ZrC tip under high-DC electric field. The dependence of photo-field emitted current with the applied voltage can be explained by the Schottky effect

Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

Energy Technology Data Exchange (ETDEWEB)

Ganter, R. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland)]. E-mail: romain.ganter@psi.ch; Bakker, R.J. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Gough, C. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Paraliev, M. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Pedrozzi, M. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Le Pimpec, F. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Rivkin, L. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland); Wrulich, A. [Paul Scherrer Institut, Villigen, CH 5232 (Switzerland)

2006-09-15

In order to find electron sources with low thermal emittance, cathodes based on single tip field emitter are investigated. Maximum peak current, measured from single tip in ZrC with a typical apex radius around 1 {mu}m, are presented. Voltage pulses of 2 ns duration and up to 50 kV amplitude lead to field emission current up to 470 mA from one ZrC tip. Combination of high applied electric field with laser illumination gives the possibility to modulate the emission with laser pulses. Nanoseconds current pulses have been emitted with laser pulses at 1064 nm illuminating a ZrC tip under high-DC electric field. The dependence of photo-field emitted current with the applied voltage can be explained by the Schottky effect.

Controlled light emission from white organic light-emitting devices with a single blue-emitting host and multiple fluorescent dopants

International Nuclear Information System (INIS)

Chin, Byung Doo; Kim, Jai Kyeong; Park, O Ok

2007-01-01

In this work, we fabricated white organic light-emitting devices (WOLEDs) containing a layered light-emitting region composed of a single blue-emitting host and different fluorescent dopant materials. The effects of varying the dye-doping ratio and emitting layer thickness on the efficiency, lifetime, spectral voltage-dependence and white balance were investigated for devices with a blue/orange stacked layer structure. Addition of a blue host layer doped with a green-emitting dopant, to give a blue/green/orange emitter, resulted in a broadband white spectrum without the need for a charge-blocking interlayer. The composition of blue, green and orange dopants in the host and the thickness of each emitting layer were optimized, resulting in a device efficiency of 9-11 cd A -1 even at a high brightness of 10 000 cd m -2 (achieved at a bias voltage of less than 9 V) with an emission spectrum suitable for lighting applications

Simulation based design strategy for EMC compliance of components in hybrid vehicles

Energy Technology Data Exchange (ETDEWEB)

Maass, Uwe; Ndip, Ivan; Hoene, Eckard; Guttowski, Stephan [Fraunhofer-Institut fuer Zuverlaessigkeit und Mikrointegration (IZM), Berlin (Germany); Tschoban, Christian; Lang, Klaus-Dieter [Technische Univ. Berlin (Germany)

2012-11-01

The design of components for the power train of hybrid vehicles needs to take into account EMC compliance standards related to hazardous electromagnetic fields. Using a simulation based design strategy allows for virtual EMC tests in parallel to the mechanical / electrical power design and thus reduces (re-)design time and costs. Taking as an example a high-voltage battery for a hybrid vehicle the emitted magnetic fields outside the battery are examined. The simulation stategy is based on 3D EM simulations using a full-wave and an eddy current solver. The simulation models are based on the actual CAD data from the mechanical construction resulting in and a high geometrical aspect ratio. The impact of simulation specific aspects such as boundary conditions and excitation is given. It was found that using field simulations it is possible to identify noise sources and coupling paths as well as aid the construction of the battery. (orig.)

On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment.

Science.gov (United States)

Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

2017-01-17

Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems.

Exchange program. Alternative options for purchase of environmentally friendly vehicles in Stockholm

Energy Technology Data Exchange (ETDEWEB)

Rader Olsson, Amy [Inregia AB, Stockholm (Sweden); Elam, N. [Atrax Energi AB, Goeteborg (Sweden)

1999-11-01

The city of Stockholm has decided to exchange 300 of its gasoline-driven vehicles for vehicles which emit fewer hazardous pollutants. A vehicle exchange program is being developed based on analyses which describe the driving patterns of Stockholm's vehicles, alternative fuel technology status, and financing alternatives. This report comprises the first two analyses, that of Stockholm's fleet driving patterns and alternative fuel technology options. The report has four major sections: * a technical analysis of the status of certain fuels and vehicles, including prognoses of availability in Sweden and the future development potential of each. (electric, biogas, ethanol, RME), * a driving study, which identifies those vehicles currently in Stockholm's fleet which could be exchanged for alternatively-fueled vehicles, * an analysis of five purchase package alternatives, and * a location analysis, which describes the accessibility of vehicles in each alternative to alternative fuel refueling facilities in Stockholm. Given current prices and availability of the alternative fuels and vehicles studied, we recommend a high share of electric and biogas vehicles for purchases during 1997. The cost-effectiveness of different vehicle types in their reduction of various hazardous pollutants, may however change dramatically as prices and availability of vehicles changes and the market for alternative fuels develops. Accessibility to alternative fuel refueling facilities is adequate in Stockholm, though not always ideal. To improve the accessibility of biogas vehicles further, we suggest a third biogas refueling facility in the city's northeastern area (Ropsten, Vaertahamnen). If MFO chooses to purchase a significant number of diesel passenger vehicles to be driven on RME; we propose that a facility in the northeastern area would improve accessibility more than another facility in southern Stockholm.

Formulating CdSe quantum dots for white light-emitting diodes with high color rendering index

International Nuclear Information System (INIS)

Li, Fei; Li, Wan-Nan; Fu, Shao-Yun; Xiao, Hong-Mei

2015-01-01

Generation of white light using CdSe quantum dots (QDs) alone presents exciting possibilities for solid state lighting technology. In this work, Cd(Ac) 2 ·2H 2 O and Na 2 SeSO 3 are used as precursors to synthesize CdSe-QDs with an average diameter ranging from 2.77 to 4.65 nm at the low temperature from 60 to 180 °C. Smaller CdSe-QDs with an average diameter of 2.29 nm are got by an oxidation etching process using H 2 O 2 as oxidant. The structural and optical properties of these QDs are investigated and proper formulation of CdSe QDs with various sizes is carefully designed to achieve white light with a high color rendering index (CRI). It is observed for the first time that the as-prepared white light-emitting diodes from single CdSe-QDs show the Commission Inernationale del’Eclairage coordinate (CIE) of (0.30,0.34) very close to that (0.33,0.33) of pure white light and a high CRI of 84. Owing to these advantages, the as-prepared white light-emitting diodes from a single compound are promising for lighting applications. - Highlights: • CdSe-quantum dots (QDs) with a continuously changing size from 2.31 to 4.74 nm are prepared. • The obtained CdSe-QDs emit lights with tunable colors in the whole visible range. • The obtained mixture sample generates white light with a high color rendering index of 84. • The sample yields white light with the CIE coordinate (0.30, 0.34) very close to that of pure white light

METEV: Measurement Technologies for Emissions from Ethanol Fuelled Vehicles

Energy Technology Data Exchange (ETDEWEB)

Sandtroem-Dahl, Charlotte

2009-11-15

The interest of using alcohols, and especially ethanol, as vehicle fuel is high in Sweden. The advantages are many, such as; being renewable, the ethanol can be produced locally and it is easily mixed with gasoline. Alcohol fuels are considered to be a substantial part of the alternative fuel market, especially in Brazil, USA and Sweden. With this growing interest it is of most importance to investigate the emission performance of vehicles fuelled with alcohols. The focus in this study is on measurement and calculation of hydrocarbon emissions. The emission regulations in different countries have different ways to treat alcohol fuelled vehicles. When alcohols are used as blending components in gasoline, uncombusted alcohols from the fuel are emitted in the exhaust in various amounts. If a Flame Ionization Detector (FID) is used to measure hydrocarbons, the uncombusted alcohol will be included in the measurement. The alcohol is, per definition, however not a hydrocarbon (hydrocarbons contains only hydrogen and carbon). In the US regulations, the alcohol content is measured separately, and the FID measurement is adjusted for the alcohol part. This is not performed in the European regulations. The aim of this project is to highlight the need for a discussion regarding the methodology for measuring hydrocarbon and alcohol emissions from flexible fuelled vehicles operating on alcohol fuel blends.

Transverse-mode-selectable microlens vertical-cavity surface-emitting laser

DEFF Research Database (Denmark)

Chung, Il-Sug; Debernardi, Pierluigi; Lee, Yong Tak

2010-01-01

A new vertical-cavity surface-emitting laser structure employing a thin microlens is suggested and numerically investigated. The laser can be made to emit in either a high-power Gaussian-shaped single-fundamental mode or a high-power doughnut-shaped higher-order mode. The physical origin...

Carbonaceous Aerosols Emitted from Light-Duty Vehicles Operating on Ethanol Fuel Blends

Science.gov (United States)

Air pollution is among the many environmental and public health concerns associated with increased ethanol use in vehicles. Jacobson [2007] showed for the U.S. market that full conversion to e85 ([85% ethanol, 15% gasoline]—the maximum standard blend used in modern dual fuel veh...

AN ASSESSMENT OF FLYWHEEL HIGH POWER ENERGY STORAGE TECHNOLOGY FOR HYBRID VEHICLES

Energy Technology Data Exchange (ETDEWEB)

Hansen, James Gerald [ORNL

2012-02-01

An assessment has been conducted for the DOE Vehicle Technologies Program to determine the state of the art of advanced flywheel high power energy storage systems to meet hybrid vehicle needs for high power energy storage and energy/power management. Flywheel systems can be implemented with either an electrical or a mechanical powertrain. The assessment elaborates upon flywheel rotor design issues of stress, materials and aspect ratio. Twelve organizations that produce flywheel systems submitted specifications for flywheel energy storage systems to meet minimum energy and power requirements for both light-duty and heavy-duty hybrid applications of interest to DOE. The most extensive experience operating flywheel high power energy storage systems in heavy-duty and light-duty hybrid vehicles is in Europe. Recent advances in Europe in a number of vehicle racing venues and also in road car advanced evaluations are discussed. As a frame of reference, nominal weight and specific power for non-energy storage components of Toyota hybrid electric vehicles are summarized. The most effective utilization of flywheels is in providing high power while providing just enough energy storage to accomplish the power assist mission effectively. Flywheels are shown to meet or exceed the USABC power related goals (discharge power, regenerative power, specific power, power density, weight and volume) for HEV and EV batteries and ultracapacitors. The greatest technical challenge facing the developer of vehicular flywheel systems remains the issue of safety and containment. Flywheel safety issues must be addressed during the design and testing phases to ensure that production flywheel systems can be operated with adequately low risk.

High-energy coherent terahertz radiation emitted by wide-angle electron beams from a laser-wakefield accelerator

Science.gov (United States)

Yang, Xue; Brunetti, Enrico; Jaroszynski, Dino A.

2018-04-01

High-charge electron beams produced by laser-wakefield accelerators are potentially novel, scalable sources of high-power terahertz radiation suitable for applications requiring high-intensity fields. When an intense laser pulse propagates in underdense plasma, it can generate femtosecond duration, self-injected picocoulomb electron bunches that accelerate on-axis to energies from 10s of MeV to several GeV, depending on laser intensity and plasma density. The process leading to the formation of the accelerating structure also generates non-injected, sub-picosecond duration, 1–2 MeV nanocoulomb electron beams emitted obliquely into a hollow cone around the laser propagation axis. These wide-angle beams are stable and depend weakly on laser and plasma parameters. Here we perform simulations to characterise the coherent transition radiation emitted by these beams if passed through a thin metal foil, or directly at the plasma–vacuum interface, showing that coherent terahertz radiation with 10s μJ to mJ-level energy can be produced with an optical to terahertz conversion efficiency up to 10‑4–10‑3.

Analysis of the Emitted Wavelet of High-Resolution Bowtie GPR Antennas

Directory of Open Access Journals (Sweden)

Manuel Pereira

2009-06-01

Full Text Available Most Ground Penetrating Radars (GPR cover a wide frequency range by emitting very short time wavelets. In this work, we study in detail the wavelet emitted by two bowtie GPR antennas with nominal frequencies of 800 MHz and 1 GHz. Knowledge of this emitted wavelet allows us to extract as much information as possible from recorded signals, using advanced processing techniques and computer simulations. Following previously published methodology used by Rial et al. [1], which ensures system stability and reliability in data acquisition, a thorough analysis of the wavelet in both time and frequency domain is performed. Most of tests were carried out with air as propagation medium, allowing a proper analysis of the geometrical attenuation factor. Furthermore, we attempt to determine, for each antenna, a time zero in the records to allow us to correctly assign a position to the reflectors detected by the radar. Obtained results indicate that the time zero is not a constant value for the evaluated antennas, but instead depends on the characteristics of the material in contact with the antenna.

The thermal management of high power light emitting diodes

Science.gov (United States)

Hsu, Ming-Seng; Huang, Jen-Wei; Shyu, Feng-Lin

2012-10-01

Thermal management had an important influence not only in the life time but also in the efficiency of high power light emitting diodes (HPLEDs). 30 watts in a single package have become standard to the industrial fabricating of HPLEDs. In this study, we fabricated both of the AlN porous films, by vacuum sputtering, soldered onto the HPLEDs lamp to enhance both of the heat transfer and heat dissipation. In our model, the ceramic enables transfer the heat from electric device to the aluminum plate quickly and the porous increase the quality of the thermal dissipation between the PCB and aluminum plate, as compared to the industrial processing. The ceramic films were characterized by several subsequent analyses, especially the measurement of real work temperature. The X-Ray diffraction (XRD) diagram analysis reveals those ceramic phases were successfully grown onto the individual substrates. The morphology of ceramic films was investigated by the atomic force microscopy (AFM). The results show those porous films have high thermal conduction to the purpose. At the same time, they had transferred heat and limited work temperature, about 70°, of HPLEDs successfully.

Influences of wide-angle and multi-beam interference on the chromaticity and efficiency of top-emitting white organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Deng, Lingling; Zhou, Hongwei; Chen, Shufen, E-mail: iamsfchen@njupt.edu.cn; Liu, Bin; Wang, Lianhui [Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Shi, Hongying [Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China); Huang, Wei, E-mail: iamdirector@njupt.edu.cn [Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Jiangsu-Singapore Joint Research Center for Organic/Bio- Electronics and Information Displays and Institute of Advanced Materials, Nanjing Tech University, Nanjing 211816 (China)

2015-02-28

Wide-angle interference (WI) and multi-beam interference (MI) in microcavity are analyzed separately to improve chromaticity and efficiency of the top-emitting white organic light-emitting diodes (TWOLEDs). A classic electromagnetic theory is used to calculate the resonance intensities of WI and MI in top-emitting organic light-emitting diodes (TOLEDs) with influence factors (e.g., electrodes and exciton locations) being considered. The role of WI on the performances of TOLEDs is revealed through using δ-doping technology and comparing blue and red EML positions in top-emitting and bottom-emitting devices. The blue light intensity significantly increases and the chromaticity of TWOLEDs is further improved with the use of enhanced WI (the blue emitting layer moving towards the reflective electrode) in the case of a weak MI. In addition, the effect of the thicknesses of light output layer and carrier transport layers on WI and MI are also investigated. Apart from the microcavity effect, other factors, e.g., carrier balance and carrier recombination regions are considered to obtain TWOLEDs with high efficiency and improved chromaticity near white light equal-energy point.

Spurious RF signals emitted by mini-UAVs

Science.gov (United States)

Schleijpen, Ric (H. M. A.); Voogt, Vincent; Zwamborn, Peter; van den Oever, Jaap

2016-10-01

This paper presents experimental work on the detection of spurious RF emissions of mini Unmanned Aerial Vehicles (mini-UAV). Many recent events have shown that mini-UAVs can be considered as a potential threat for civil security. For this reason the detection of mini-UAVs has become of interest to the sensor community. The detection, classification and identification chain can take advantage of different sensor technologies. Apart from the signatures used by radar and electro-optical sensor systems, the UAV also emits RF signals. These RF signatures can be split in intentional signals for communication with the operator and un-intentional RF signals emitted by the UAV. These unintentional or spurious RF emissions are very weak but could be used to discriminate potential UAV detections from false alarms. The goal of this research was to assess the potential of exploiting spurious emissions in the classification and identification chain of mini-UAVs. It was already known that spurious signals are very weak, but the focus was on the question whether the emission pattern could be correlated to the behaviour of the UAV. In this paper experimental examples of spurious RF emission for different types of mini-UAVs and their correlation with the electronic circuits in the UAVs will be shown

Highly Efficient Light-Emitting Diodes of Colloidal Metal-Halide Perovskite Nanocrystals beyond Quantum Size.

Science.gov (United States)

Kim, Young-Hoon; Wolf, Christoph; Kim, Young-Tae; Cho, Himchan; Kwon, Woosung; Do, Sungan; Sadhanala, Aditya; Park, Chan Gyung; Rhee, Shi-Woo; Im, Sang Hyuk; Friend, Richard H; Lee, Tae-Woo

2017-07-25

Colloidal metal-halide perovskite quantum dots (QDs) with a dimension less than the exciton Bohr diameter D B (quantum size regime) emerged as promising light emitters due to their spectrally narrow light, facile color tuning, and high photoluminescence quantum efficiency (PLQE). However, their size-sensitive emission wavelength and color purity and low electroluminescence efficiency are still challenging aspects. Here, we demonstrate highly efficient light-emitting diodes (LEDs) based on the colloidal perovskite nanocrystals (NCs) in a dimension > D B (regime beyond quantum size) by using a multifunctional buffer hole injection layer (Buf-HIL). The perovskite NCs with a dimension greater than D B show a size-irrespective high color purity and PLQE by managing the recombination of excitons occurring at surface traps and inside the NCs. The Buf-HIL composed of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) and perfluorinated ionomer induces uniform perovskite particle films with complete film coverage and prevents exciton quenching at the PEDOT:PSS/perovskite particle film interface. With these strategies, we achieved a very high PLQE (∼60.5%) in compact perovskite particle films without any complex post-treatments and multilayers and a high current efficiency of 15.5 cd/A in the LEDs of colloidal perovskite NCs, even in a simplified structure, which is the highest efficiency to date in green LEDs that use colloidal organic-inorganic metal-halide perovskite nanoparticles including perovskite QDs and NCs. These results can help to guide development of various light-emitting optoelectronic applications based on perovskite NCs.

High-Speed Semiconductor Vertical-Cavity Surface-Emitting Lasers for Optical Data-Transmission Systems (Review)

Science.gov (United States)

Blokhin, S. A.; Maleev, N. A.; Bobrov, M. A.; Kuzmenkov, A. G.; Sakharov, A. V.; Ustinov, V. M.

2018-01-01

The main problems of providing a high-speed operation semiconductor lasers with a vertical microcavity (so-called "vertical-cavity surface-emitting lasers") under amplitude modulation and ways to solve them have been considered. The influence of the internal properties of the radiating active region and the electrical parasitic elements of the equivalent circuit of lasers are discussed. An overview of approaches that lead to an increase of the cutoff parasitic frequency, an increase of the differential gain of the active region, the possibility of the management of mode emission composition and the lifetime of photons in the optical microcavities, and reduction of the influence of thermal effects have been presented. The achieved level of modulation bandwidth of ˜30 GHz is close to the maximum achievable for the classical scheme of the direct-current modulation, which makes it necessary to use a multilevel modulation format to further increase the information capacity of optical channels constructed on the basis of vertical-cavity surface-emitting lasers.

High-quality vertical light emitting diodes fabrication by mechanical lift-off technique

Science.gov (United States)

Tu, Po-Min; Hsu, Shih-Chieh; Chang, Chun-Yen

2011-10-01

We report the fabrication of mechanical lift-off high quality thin GaN with Hexagonal Inversed Pyramid (HIP) structures for vertical light emitting diodes (V-LEDs). The HIP structures were formed at the GaN/sapphire substrate interface under high temperature during KOH wet etching process. The average threading dislocation density (TDD) was estimated by transmission electron microscopy (TEM) and found the reduction from 2×109 to 1×108 cm-2. Raman spectroscopy analysis revealed that the compressive stress of GaN epilayer was effectively relieved in the thin-GaN LED with HIP structures. Finally, the mechanical lift-off process is claimed to be successful by using the HIP structures as a sacrificial layer during wafer bonding process.

A High-Power Wireless Charging System Development and Integration for a Toyota RAV4 Electric Vehicle

Energy Technology Data Exchange (ETDEWEB)

Onar, Omer C [ORNL; Seiber, Larry Eugene [ORNL; White, Cliff P [ORNL; Chinthavali, Madhu Sudhan [ORNL; Campbell, Steven L [ORNL

2016-01-01

Several wireless charging methods are underdevelopment or available as an aftermarket option in the light-duty automotive market. However, there are not many studies detailing the vehicle integrations, particularly a complete vehicle integration with higher power levels. This paper presents the development, implementation, and vehicle integration of a high-power (>10 kW) wireless power transfer (WPT)-based electric vehicle (EV) charging system for a Toyota RAV4 vehicle. The power stages of the system are introduced with the design specifications and control systems including the active front-end rectifier with power factor correction (PFC), high frequency power inverter, high frequency isolation transformer, coupling coils, vehicle side full-bridge rectifier and filter, and the vehicle battery. The operating principles of the control, communications, and protection systems are also presented in addition to the alignment and the driver interface system. The physical limitations of the system are also defined that would prevent the system operating at higher levels. The experiments are carried out using the integrated vehicle and the results obtained to demonstrate the system performance including the stage-by-stage efficiencies with matched and interoperable primary and secondary coils.

Effective public communication and marketing of high-occupancy-vehicle lanes : an agency perspective

Science.gov (United States)

1997-01-01

The Massachusetts Highway Department (MassHighway) opened the Southeast Expressway high-occupancy-vehicle (HOV) lane on November 15, 1995. The 6-mi (9.6-km) contraflow lane, open to vehicles with at least three occupants, was MassHighways third at...

The effects of CO2-differentiated vehicle tax systems on car choice, CO2 emissions and tax revenues

NARCIS (Netherlands)

Kok, R.

2011-01-01

This paper assesses the impacts of a CO2-differentiated tax policy designed to influence car purchasing trends towards lower CO2 emitting vehicles in the Netherlands. Since 2009, gasoline and diesel cars up to 110 and 95 gram CO2 per km are exempted from the vehicle registration tax (VRT). In

Top-Emitting White Organic Light-Emitting Diodes Based on Cu as Both Anode and Cathode

International Nuclear Information System (INIS)

Mu Ye; Zhang Zhen-Song; Wang Hong-Bo; Qu Da-Long; Wu Yu-Kun; Yan Ping-Rui; Li Chuan-Nan; Zhao Yi

2015-01-01

It is still challenging to obtain broadband emission covering visible light spectrum as much as possible with negligible angular dependence. In this work, we demonstrate a low driving voltage top-emitting white organic light-emitting diode (TEWOLED) based on complementary blue and yellow phosphor emitters with negligible angular dependence. The bottom copper anode with medium reflectance, which is compatible with the standard complementary metal oxide semiconductor (CMOS) technology below 0.13 μm, and the semitransparent multilayer Cs2CO3/Al/Cu cathode as a top electrode, are introduced to realize high-performance TEWOLED. Our TEWOLED achieves high efficiencies of 15.4 cd/A and 12.1 lm/W at a practical brightness of 1000 cd/m 2 at low voltage of 4 V. (paper)

PM₂.₅ emissions from light-duty gasoline vehicles in Beijing, China.

Science.gov (United States)

Shen, Xianbao; Yao, Zhiliang; Huo, Hong; He, Kebin; Zhang, Yingzhi; Liu, Huan; Ye, Yu

2014-07-15

As stricter standards for diesel vehicles are implemented in China, and the use of diesel trucks is forbidden in urban areas, determining the contribution of light-duty gasoline vehicles (LDGVs) to on-road PM2.5 emissions in cities is important. Additionally, in terms of particle number and size, particulates emitted from LDGVs have a greater health impact than particulates emitted from diesel vehicles. In this work, we measured PM2.5 emissions from 20 LDGVs in Beijing, using an improved combined on-board emission measurement system. We compared these measurements with those reported in previous studies, and estimated the contribution of LDGVs to on-road PM2.5 emissions in Beijing. The results show that the PM2.5 emission factors for LDGVs, complying with European Emission Standards Euro-0 through Euro-4 were: 117.4 ± 142, 24.1 ± 20.4, 4.85 ± 7.86, 0.99 ± 1.32, 0.17 ± 0.15 mg/km, respectively. Our results show a significant decline in emissions with improving vehicle technology. However, this trend is not reflected in recent emission inventory studies. The daytime contributions of LDGVs to PM2.5 emissions on highways, arterials, residential roads, and within urban areas of Beijing were 44%, 62%, 57%, and 57%, respectively. The contribution of LDGVs to PM2.5 emissions varied both for different road types and for different times. Copyright © 2014 Elsevier B.V. All rights reserved.

Using rare earth doped thiosilicate phosphors in white light emitting LEDs: Towards low colour temperature and high colour rendering

International Nuclear Information System (INIS)

Smet, P.F.; Korthout, K.; Haecke, J.E. van; Poelman, D.

2008-01-01

Rare earth doped thiosilicates are promising materials for use in phosphor converted light emitting diodes (pcLEDs). These phosphors (including the hosts Ca 2 SiS 4 , BaSi 2 S 5 and Ba 2 SiS 4 in combination with Ce 3+ and/or Eu 2+ doping) cover the entire visible part of the spectrum, as the emission colour can be changed from deep blue to red. The photoluminescence emission spectrum and the overlap of the excitation spectrum with the emission of pumping LEDs is evaluated. The trade-off between high colour rendering and high electrical-to-optical power efficiency is discussed by simulation with both blue and UV emitting LEDs. Finally, a phosphor combination with low colour temperature (3000 K) and high colour rendering (CRI = 93) is proposed

A Strategy for Architecture Design of Crystalline Perovskite Light-Emitting Diodes with High Performance.

Science.gov (United States)

Shi, Yifei; Wu, Wen; Dong, Hua; Li, Guangru; Xi, Kai; Divitini, Giorgio; Ran, Chenxin; Yuan, Fang; Zhang, Min; Jiao, Bo; Hou, Xun; Wu, Zhaoxin

2018-06-01

All present designs of perovskite light-emitting diodes (PeLEDs) stem from polymer light-emitting diodes (PLEDs) or perovskite solar cells. The optimal structure of PeLEDs can be predicted to differ from PLEDs due to the different fluorescence dynamics and crystallization between perovskite and polymer. Herein, a new design strategy and conception is introduced, "insulator-perovskite-insulator" (IPI) architecture tailored to PeLEDs. As examples of FAPbBr 3 and MAPbBr 3 , it is experimentally shown that the IPI structure effectively induces charge carriers into perovskite crystals, blocks leakage currents via pinholes in the perovskite film, and avoids exciton quenching simultaneously. Consequently, as for FAPbBr 3 , a 30-fold enhancement in the current efficiency of IPI-structured PeLEDs compared to a control device with poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) as hole-injection layer is achieved-from 0.64 to 20.3 cd A -1 -while the external quantum efficiency is increased from 0.174% to 5.53%. As the example of CsPbBr 3 , compared with the control device, both current efficiency and lifetime of IPI-structured PeLEDs are improved from 1.42 and 4 h to 9.86 cd A -1 and 96 h. This IPI architecture represents a novel strategy for the design of light-emitting didoes based on various perovskites with high efficiencies and stabilities. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detailed modeling of electron emission for transpiration cooling of hypersonic vehicles

Science.gov (United States)

Hanquist, Kyle M.; Hara, Kentaro; Boyd, Iain D.

2017-02-01

Electron transpiration cooling (ETC) is a recently proposed approach to manage the high heating loads experienced at the sharp leading edges of hypersonic vehicles. Computational fluid dynamics (CFD) can be used to investigate the feasibility of ETC in a hypersonic environment. A modeling approach is presented for ETC, which includes developing the boundary conditions for electron emission from the surface, accounting for the space-charge limit effects of the near-wall plasma sheath. The space-charge limit models are assessed using 1D direct-kinetic plasma sheath simulations, taking into account the thermionically emitted electrons from the surface. The simulations agree well with the space-charge limit theory proposed by Takamura et al. for emitted electrons with a finite temperature, especially at low values of wall bias, which validates the use of the theoretical model for the hypersonic CFD code. The CFD code with the analytical sheath models is then used for a test case typical of a leading edge radius in a hypersonic flight environment. The CFD results show that ETC can lower the surface temperature of sharp leading edges of hypersonic vehicles, especially at higher velocities, due to the increase in ionized species enabling higher electron heat extraction from the surface. The CFD results also show that space-charge limit effects can limit the ETC reduction of surface temperatures, in comparison to thermionic emission assuming no effects of the electric field within the sheath.

Analysis of acoustic data for hybrid and electric vehicles measured on hemi-anechoic chambers

Science.gov (United States)

2015-04-01

The Pedestrian Safety Enhancement Act of 2010 requires the National Highway Traffic Safety : Administration to conduct a rulemaking to establish a Federal Motor Vehicle Safety Standard requiring an alert sound for pedestrians to be emitted by electri...

Broadband mid-infrared superlattice light-emitting diodes

Science.gov (United States)

Ricker, R. J.; Provence, S. R.; Norton, D. T.; Boggess, T. F.; Prineas, J. P.

2017-05-01

InAs/GaSb type-II superlattice light-emitting diodes were fabricated to form a device that provides emission over the entire 3-5 μm mid-infrared transmission window. Variable bandgap emission regions were coupled together using tunnel junctions to emit at peak wavelengths of 3.3 μm, 3.5 μm, 3.7 μm, 3.9 μm, 4.1 μm, 4.4 μm, 4.7 μm, and 5.0 μm. Cascading the structure recycles the electrons in each emission region to emit several wavelengths simultaneously. At high current densities, the light-emitting diode spectra broadened into a continuous, broadband spectrum that covered the entire mid-infrared band. When cooled to 77 K, radiances of over 1 W/cm2 sr were achieved, demonstrating apparent temperatures above 1000 K over the 3-5 μm band. InAs/GaSb type-II superlattices are capable of emitting from 3 μm to 30 μm, and the device design can be expanded to include longer emission wavelengths.

Mass size distribution of particles emitted by diesel engines and determination of the contribution of diesel particles to the atmospheric aerosol in Vienna by using a tracer suitable for activation analysis

International Nuclear Information System (INIS)

Norek, C.

1985-01-01

In Vienna a large fraction of light absorbing aerosols has been found. The traffic could be a source for the high absorption coefficients, since the time dependent absorption coefficients varise similar to the traffic densities. Diesel vehicles have high soot emissions, so they may contribute considerably to light absorption during the summer. The emission factors of the vehicles were estimated by measurements at different motor and driving conditions by the Constant-Volume-Sampling-Method. To determine the size distributions a 10-stage-low pressure impactor with a lower cut size of 0.015 μm aerodynamic particle diameter was used. In order to estimate the contribution of diesel vehicles to the total mass concentrations all diesel fuel sold in Vienna and its vincinity was marked with an organic Dysprosium compound. This rare earth tracer was emitted by vehicles together with the soot particles and collected at eleven stations in Vienna. The filter samples were extracted with diluted HNO 3 and the extraction was analysed for Dy by neutron activation analysis. The mass size distributions of the particles and the soot emitted from diesel engines are only slightly influenced by motor and driving parameters. The total mass emissions showed considerable variations, but the mean emission factor obtained from the tests was 2.43 g per litre fuel; knowing also the concentration of the tracer in the fuel, the contribution of diesel particles to the mass of the suspended particulates could be estimated. During the measuring period the contribution was c. 25% to the total mass and c. 40% to the absorbing matter in the atmosphere. (Author)

AlGaN-based deep-ultraviolet light-emitting diodes grown on high-quality AlN template using MOVPE

KAUST Repository

Yan, Jianchang; Wang, Junxi; Zhang, Yun; Cong, Peipei; Sun, Lili; Tian, Yingdong; Zhao, Chao; Li, Jinmin

2015-01-01

In this article, we report the growth of high-quality AlN film using metal-organic vapor phase epitaxy. Three layers of middle-temperature (MT) AlN were introduced during the high-temperature (HT) AlN growth. During the MT-AlN layer growth, aluminum and nitrogen sources were closed for 6 seconds after every 5-nm MT-AlN, while H2 carrier gas was always on. The threading dislocation density in an AlN epi-layer on a sapphire substrate was reduced by almost half. AlGaN-based deep-ultraviolet light-emitting diodes were further fabricated based on the AlN/sapphire template. At 20 mA driving current, the emitted peak wavelength is 284.5 nm and the light output power exceeds 3 mW.

AlGaN-based deep-ultraviolet light-emitting diodes grown on high-quality AlN template using MOVPE

KAUST Repository

Yan, Jianchang

2015-03-01

In this article, we report the growth of high-quality AlN film using metal-organic vapor phase epitaxy. Three layers of middle-temperature (MT) AlN were introduced during the high-temperature (HT) AlN growth. During the MT-AlN layer growth, aluminum and nitrogen sources were closed for 6 seconds after every 5-nm MT-AlN, while H2 carrier gas was always on. The threading dislocation density in an AlN epi-layer on a sapphire substrate was reduced by almost half. AlGaN-based deep-ultraviolet light-emitting diodes were further fabricated based on the AlN/sapphire template. At 20 mA driving current, the emitted peak wavelength is 284.5 nm and the light output power exceeds 3 mW.

Studies on the levitation height decay of the high temperature superconducting Maglev vehicle

International Nuclear Information System (INIS)

Deng, Z.G.; Zheng, J.; Zhang, J.; Wang, J.S.; Wang, S.Y.; Zhang, Y.; Liu, L.

2007-01-01

The levitation height decay was found in the high temperature superconducting (HTS) Maglev test vehicle system during man-loading running. Experimental results show that the no-load levitating system would drift to a new equilibrium position by the external loaded history, but the new equilibrium position will almost not drift by the second-round same loaded history. A new method is proposed to improve the stability of the HTS Maglev vehicle, that is, a pre-load was applied to the HTS Maglev vehicle before running. The impulse responses are performed on the HTS Maglev vehicle before the pre-load and after the pre-load. The results show that the pre-load method is considerably effective to improve the stiffness and damping coefficient of the HTS Maglev vehicle. Moreover, it helps to suppress the levitation height decay and enhance the stability of the HTS Maglev vehicle in practical operation

Highly efficient and heavily-doped organic light-emitting devices based on an orange phosphorescent iridium complex

International Nuclear Information System (INIS)

Zhou, Shunliang; Wang, Qi; Li, Ming; Lu, Zhiyun; Yu, Junsheng

2014-01-01

Heavily doped and highly efficient phosphorescent organic light-emitting devices (PhOLEDs) had been fabricated by utilizing an orange iridium complex, bis[2-(3′,5′-di-tert-butylbiphenyl-4-yl)benzothiazolato-N,C 2' ]iridium(III) (acetylacetonate) [(tbpbt) 2 Ir(acac)], as a phosphor. When the doping concentration of [(tbpbt) 2 Ir(acac)] reached as high as 15 wt%, the PhOLEDs exhibited a power efficiency, current efficiency, and external quantum efficiency of 24.5 lm/W, 32.1 cd/A, 15.7%, respectively, implying a promising quenching-resistant characteristics of this novel phosphor. Furthermore, the efficient white PhOLEDs had been obtained by employing (tbpbt) 2 Ir(acac) as a self-host orange emitter, indicating that (tbpbt) 2 Ir(acac) could serve as a promising phosphor to fabricate white organic light-emitting devices with simplified manufacturing process. - Highlights: • Efficient phosphorescent devices were fabricated. • Optimized phosphor doping ratio reached as high as 15 wt%. • The results proved a promising quench-resistant property of the phosphor. • Efficient white devices based on this phosphor as self-host layer had been realized

Highly efficient and heavily-doped organic light-emitting devices based on an orange phosphorescent iridium complex

Energy Technology Data Exchange (ETDEWEB)

Zhou, Shunliang; Wang, Qi [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Li, Ming [College of Chemistry, Sichuan University, Chengdu, 610064 (China); Lu, Zhiyun, E-mail: luzhiyun@scu.edu.cn [College of Chemistry, Sichuan University, Chengdu, 610064 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

2014-10-15

Heavily doped and highly efficient phosphorescent organic light-emitting devices (PhOLEDs) had been fabricated by utilizing an orange iridium complex, bis[2-(3′,5′-di-tert-butylbiphenyl-4-yl)benzothiazolato-N,C{sup 2'}]iridium(III) (acetylacetonate) [(tbpbt){sub 2}Ir(acac)], as a phosphor. When the doping concentration of [(tbpbt){sub 2}Ir(acac)] reached as high as 15 wt%, the PhOLEDs exhibited a power efficiency, current efficiency, and external quantum efficiency of 24.5 lm/W, 32.1 cd/A, 15.7%, respectively, implying a promising quenching-resistant characteristics of this novel phosphor. Furthermore, the efficient white PhOLEDs had been obtained by employing (tbpbt){sub 2}Ir(acac) as a self-host orange emitter, indicating that (tbpbt){sub 2}Ir(acac) could serve as a promising phosphor to fabricate white organic light-emitting devices with simplified manufacturing process. - Highlights: • Efficient phosphorescent devices were fabricated. • Optimized phosphor doping ratio reached as high as 15 wt%. • The results proved a promising quench-resistant property of the phosphor. • Efficient white devices based on this phosphor as self-host layer had been realized.

Towards cooperative guidance and control of highly automated vehicles: H-Mode and Conduct-by-Wire.

Science.gov (United States)

Flemisch, Frank Ole; Bengler, Klaus; Bubb, Heiner; Winner, Hermann; Bruder, Ralph

2014-01-01

This article provides a general ergonomic framework of cooperative guidance and control for vehicles with an emphasis on the cooperation between a human and a highly automated vehicle. In the twenty-first century, mobility and automation technologies are increasingly fused. In the sky, highly automated aircraft are flying with a high safety record. On the ground, a variety of driver assistance systems are being developed, and highly automated vehicles with increasingly autonomous capabilities are becoming possible. Human-centred automation has paved the way for a better cooperation between automation and humans. How can these highly automated systems be structured so that they can be easily understood, how will they cooperate with the human? The presented research was conducted using the methods of iterative build-up and refinement of framework by triangulation, i.e. by instantiating and testing the framework with at least two derived concepts and prototypes. This article sketches a general, conceptual ergonomic framework of cooperative guidance and control of highly automated vehicles, two concepts derived from the framework, prototypes and pilot data. Cooperation is exemplified in a list of aspects and related to levels of the driving task. With the concept 'Conduct-by-Wire', cooperation happens mainly on the guidance level, where the driver can delegate manoeuvres to the automation with a specialised manoeuvre interface. With H-Mode, a haptic-multimodal interaction with highly automated vehicles based on the H(orse)-Metaphor, cooperation is mainly done on guidance and control with a haptically active interface. Cooperativeness should be a key aspect for future human-automation systems. Especially for highly automated vehicles, cooperative guidance and control is a research direction with already promising concepts and prototypes that should be further explored. The application of the presented approach is every human-machine system that moves and includes high

Influence of Camera Setting on Vehicle-to-Vehicle VLC Employing Undersampled Phase Shift On-Off Keying

Directory of Open Access Journals (Sweden)

S. Vitek

2017-12-01

Full Text Available This paper focuses on the performance analysis of a camera based vehicle-to-vehicle visible light communication system employing undersampled phase shift on-off keying modulation under interference scenario. Two Nissan Qashqai front lights with daylight running light emitting diodes based lamps are used for communications. The bit error rate (BER performance of the proposed system is experimentally measured for a transmission span up to 24m focusing mostly on the side interference due to reflections. Based on experimental data we demonstrate reduction of the system performance due to the side reflection and illumination of the detector by other light sources which has to taken into account during further data processing. We provide with further statistics for particular shuter speed and transmitter power setting and discus BER improvement especially to meet FEC via the method of adaptive region of interest.

Optimized optical wireless channel for indoor and intra-vehicle communications: power distribution and SNR analysis

Science.gov (United States)

Shaaban, Rana; Faruque, Saleh

2018-01-01

Light emitting diodes - LEDs are modernizing the indoor illumination and replacing current incandescent and fluorescent lamps rapidly. LEDs have multiple advantages such as extremely high energy efficient, longer lifespan, and lower heat generation. Due to the ability to switch to different light intensity at a very fast rate, LED has given rise to a unique communication technology (visible light communication - VLC) used for high speed data transmission. By studying various kinds of commonly used VLC channel analysis: diffuse and line of sight channels, we presented a simply improved indoor and intra-vehicle visible light communication transmission model. Employing optical wireless communications within the vehicle, not only enhance user mobility, but also alleviate radio frequency interference, and increase efficiency by lowering the complexity of copper cabling. Moreover, a solution to eliminate ambient noise caused by environmental conditions is examined by using optical differential receiver. The simulation results show the improved received power distribution and signal to noise ratio - SNR.

Investigation of new vehicle detectors for high-speed signalized intersections.

Science.gov (United States)

2015-09-01

Early indications from the use of the newest vehicle detectors for high-speed signalized intersections : suggested that they perform well as replacements for the Texas Department of Transportations : (TxDOTs) legacy systems, but this early conc...

Highly efficient tandem organic light-emitting devices employing an easily fabricated charge generation unit

Science.gov (United States)

Yang, Huishan; Yu, Yaoyao; Wu, Lishuang; Qu, Biao; Lin, Wenyan; Yu, Ye; Wu, Zhijun; Xie, Wenfa

2018-02-01

We have realized highly efficient tandem organic light-emitting devices (OLEDs) employing an easily fabricated charge generation unit (CGU) combining 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile with ultrathin bilayers of CsN3 and Al. The charge generation and separation processes of the CGU have been demonstrated by studying the differences in the current density-voltage characteristics of external-carrier-excluding devices. At high luminances of 1000 and 10000 cd/m2, the current efficiencies of the phosphorescent tandem device are about 2.2- and 2.3-fold those of the corresponding single-unit device, respectively. Simultaneously, an efficient tandem white OLED exhibiting high color stability and warm white emission has also been fabricated.

High-Glass-Transition-Temperature Polyimides Developed for Reusable Launch Vehicle Applications

Science.gov (United States)

Chuang, Kathy; Ardent, Cory P.

2002-01-01

Polyimide composites have been traditionally used for high-temperature applications in aircraft engines at temperatures up to 550 F (288 C) for thousands of hours. However, as NASA shifts its focus toward the development of advanced reusable launch vehicles, there is an urgent need for lightweight polymer composites that can sustain 600 to 800 F (315 to 427 C) for short excursions (hundreds of hours). To meet critical vehicle weight targets, it is essential that one use lightweight, high-temperature polymer matrix composites in propulsion components such as turbopump housings, ducts, engine supports, and struts. Composite materials in reusable launch vehicle components will heat quickly during launch and reentry. Conventional composites, consisting of layers of fabric or fiber-reinforced lamina, would either blister or encounter catastrophic delamination under high heating rates above 300 C. This blistering and delamination are the result of a sudden volume expansion within the composite due to the release of absorbed moisture and gases generated by the degradation of the polymer matrix. Researchers at the NASA Glenn Research Center and the Boeing Company (Long Beach, CA) recently demonstrated a successful approach for preventing this delamination--the use of three-dimensional stitched composites fabricated by resin infusion.

Quantum-cascade laser photoacoustic detection of methane emitted from natural gas powered engines

Science.gov (United States)

Rocha, M. V.; Sthel, M. S.; Silva, M. G.; Paiva, L. B.; Pinheiro, F. W.; Miklòs, A.; Vargas, H.

2012-03-01

In this work we present a laser photoacoustic arrangement for the detection of the important greenhouse gas methane. A quantum-cascade laser and a differential photoacoustic cell were employed. A detection limit of 45 ppbv in nitrogen was achieved as well as a great selectivity. The same methodology was also tested in the detection of methane issued from natural gas powered vehicles (VNG) in Brazil, which demonstrates the excellent potential of this arrangement for greenhouse gas detection emitted from real sources.

High Performance Hybrid Upper Stage for NanoLaunch Vehicles, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Parabilis Space Technologies, Inc. (Parabilis), in collaboration with Utah State University (USU), proposes a low cost, high performance launch vehicle upper stage...

Scaling model for a speed-dependent vehicle noise spectrum

Directory of Open Access Journals (Sweden)

Giovanni Zambon

2017-06-01

Full Text Available Considering the well-known features of the noise emitted by moving sources, a number of vehicle characteristics such as speed, unladen mass, engine size, year of registration, power and fuel were recorded in a dedicated monitoring campaign performed in three different places, each characterized by different number of lanes and the presence of nearby reflective surfaces. A full database of 144 vehicles (cars was used to identify statistically relevant features. In order to compare the vehicle transit noise in different environmental condition, all 1/3-octave band spectra were normalized and analysed. Unsupervised clustering algorithms were employed to group together spectrum levels with similar profiles. Our results corroborate the well-known fact that speed is the most relevant characteristic to discriminate between different vehicle noise spectrum. In keeping with this fact, we present a new approach to predict analytically noise spectra for a given vehicle speed. A set of speed-dependent analytical functions are suggested in order to fit the normalized average spectrum profile at different speeds. This approach can be useful for predicting vehicle speed based purely on its noise spectrum pattern. The present work is complementary to the accurate analysis of noise sources based on the beamforming technique.

High-efficiency green phosphorescent organic light-emitting diodes with double-emission layer and thick N-doped electron transport layer

Energy Technology Data Exchange (ETDEWEB)

Nobuki, Shunichiro, E-mail: shunichiro.nobuki.nb@hitachi.com [Hitachi Research Laboratory, Hitachi Ltd., 7-1-1 Omika-cho, Hitachi-city, Ibaraki 319-1292 (Japan); Wakana, Hironori; Ishihara, Shingo [Hitachi Research Laboratory, Hitachi Ltd., 7-1-1 Omika-cho, Hitachi-city, Ibaraki 319-1292 (Japan); Mikami, Akiyoshi [Dept. of Electrical Engineering, Kanazawa Institute of Technology, 7-1 Ohgigaoka, Nonoichimachi, Ishikawa 921-8501 (Japan)

2014-03-03

We have developed green phosphorescent organic light-emitting diodes (OLEDs) with high external quantum efficiency of 59.7% and power efficiency of 243 lm/W at 2.73 V at 0.053 mA/cm{sup 2}. A double emission layer and a thick n-doped electron transport layer were adopted to improve the exciton recombination factor. A high refractive index hemispherical lens was attached to a high refractive index substrate for extracting light trapped inside the substrate and the multiple-layers of OLEDs to air. Additionally, we analyzed an energy loss mechanism to clarify room for the improvement of our OLEDs including the charge balance factor. - Highlights: • We developed high efficiency green phosphorescent organic light-emitting diode (OLED). • Our OLED had external quantum efficiency of 59.7% and power efficiency of 243 lm/W. • A double emission layer and thick n-doped electron transport layer were adopted. • High refractive index media (hemispherical lens and substrate) were also used. • We analyzed an energy loss mechanism to clarify the charge balance factor of our OLED.

Selective detection and characterization of nanoparticles from motor vehicles.

Science.gov (United States)

Johnston, Murray V; Klems, Joseph P; Zordan, Christopher A; Pennington, M Ross; Smith, James N

2013-02-01

distribution of emissions from individual vehicles, we correlated camera images with the spike contribution to particle number concentration at each time point. A small percentage of motor vehicles were found to emit a disproportionally large concentration of nanoparticles, and these high emitters included both spark-ignition (SI) and heavy-duty diesel (HDD) vehicles. In addition to characterizing the contribution of the spikes (local sources) to the ambient number concentration, we developed a method to determine the net contribution of motor vehicles (all sources) to the total mass concentration of ambient nanoparticles. To do this, we correlated the concentration of spikes with measurements of fast changes in the chemical composition of nanoparticles measured with the nano aerosol mass spectrometer (NAMS; built by the Johnston group). The NAMS irradiates individual, size-selected nanoparticles with a high-energy laser pulse to generate a mass spectrum consisting of multiply charged atomic ions. The elemental composition of each particle was determined from the ion signal intensities of each element. However, overlapping mass-to-charge ratios (m/z) at 4 m/z (O(+4) and C(+3)) and at 8 m/z (O(+2) and S(+4)) needed to be separated into their component ions to obtain a representative composition. To do this, we developed a method to deconvolute these ion signals using sucrose and ammonium sulfate [(NH4)2SO4] as calibration standards. With this approach, the differences between the expected and measured elemental mole fractions of carbon (C), oxygen (O), nitrogen (N), and sulfur (S) for a variety of test particles were generally much less than 10%. Ambient nanoparticles were found to consist mostly of C, O, N, and S. Many particles also contained silicon (Si). The elemental compositions were apportioned into molecular species that are commonly found in ambient aerosol: sulfate (SO4(2-)), nitrate (NO3-), ammonium (NH4+), carbonaceous matter, and when present, silicon dioxide (SiO2

Vehicle detection from very-high-resolution (VHR) aerial imagery using attribute belief propagation (ABP)

Science.gov (United States)

Wang, Yanli; Li, Ying; Zhang, Li; Huang, Yuchun

2016-10-01

With the popularity of very-high-resolution (VHR) aerial imagery, the shape, color, and context attribute of vehicles are better characterized. Due to the various road surroundings and imaging conditions, vehicle attributes could be adversely affected so that vehicle is mistakenly detected or missed. This paper is motivated to robustly extract the rich attribute feature for detecting the vehicles of VHR imagery under different scenarios. Based on the hierarchical component tree of vehicle context, attribute belief propagation (ABP) is proposed to detect salient vehicles from the statistical perspective. With the Max-tree data structure, the multi-level component tree around the road network is efficiently created. The spatial relationship between vehicle and its belonging context is established with the belief definition of vehicle attribute. To effectively correct single-level belief error, the inter-level belief linkages enforce consistency of belief assignment between corresponding components at different levels. ABP starts from an initial set of vehicle belief calculated by vehicle attribute, and then iterates through each component by applying inter-level belief passing until convergence. The optimal value of vehicle belief of each component is obtained via minimizing its belief function iteratively. The proposed algorithm is tested on a diverse set of VHR imagery acquired in the city and inter-city areas of the West and South China. Experimental results show that the proposed algorithm can detect vehicle efficiently and suppress the erroneous effectively. The proposed ABP framework is promising to robustly classify the vehicles from VHR Aerial imagery.

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.

Hybrid Light-Emitting Diode Enhanced With Emissive Nanocrystals

DEFF Research Database (Denmark)

Kopylov, Oleksii

This thesis investigates a new type of white light emitting hybrid diode, composed of a light emitting GaN/InGaN LED and a layer of semiconductor nanocrystals for color conversion. Unlike standard white LEDs, the device is configured to achieve high color conversion efficiency via non-radiative e......This thesis investigates a new type of white light emitting hybrid diode, composed of a light emitting GaN/InGaN LED and a layer of semiconductor nanocrystals for color conversion. Unlike standard white LEDs, the device is configured to achieve high color conversion efficiency via non...... of the hybrid diode fabrication including process techniques for GaN LED and incorporation of the nanocrystals are presented with the emphasis on the differences with standard LED processing. Results and analysis of optical and electrical characterization including photoluminescence (PL), micro-PL, time......-resolved PL and electroluminescence (EL) together with current-voltage characteristics are presented to evaluate the device performance. A clear evidence of non-radiative energy transfer was seen in the carrier dynamics of both the LED and the nanocrystals when the quantum well – nanocrystals separation...

High efficient white organic light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Seidel, Stefan; Krause, Ralf [Department of Materials Science VI, University of Erlangen-Nuremberg (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Kozlowski, Fryderyk; Schmid, Guenter; Hunze, Arvid [Siemens AG, CT MM 1, Erlangen (Germany); Winnacker, Albrecht [Department of Materials Science VI, University of Erlangen-Nuremberg (Germany)

2007-07-01

Due to the rapid progress in the last years the performance of organic light emitting diodes (OLEDs) has reached a level where general lighting presents a most interesting application target. We demonstrate, how the color coordinates of the emission spectrum can be adjusted using a combinatorial evaporation tool to lie on the desired black body curve representing cold and warm white, respectively. The evaluation includes phosphorescent and fluorescent dye approaches to optimize lifetime and efficiency, simultaneously. Detailed results are presented with respect to variation of layer thicknesses and dopant concentrations of each layer within the OLED stack. The most promising approach contains phosphorescent red and green dyes combined with a fluorescent blue one as blue phosphorescent dopants are not yet stable enough to achieve long lifetimes.

Model and algorithm for bi-fuel vehicle routing problem to reduce GHG emissions.

Science.gov (United States)

Abdoli, Behroz; MirHassani, Seyed Ali; Hooshmand, Farnaz

2017-09-01

Because of the harmful effects of greenhouse gas (GHG) emitted by petroleum-based fuels, the adoption of alternative green fuels such as biodiesel and compressed natural gas (CNG) is an inevitable trend in the transportation sector. However, the transition to alternative fuel vehicle (AFV) fleets is not easy and, particularly at the beginning of the transition period, drivers may be forced to travel long distances to reach alternative fueling stations (AFSs). In this paper, the utilization of bi-fuel vehicles is proposed as an operational approach. We present a mathematical model to address vehicle routing problem (VRP) with bi-fuel vehicles and show that the utilization of bi-fuel vehicles can lead to a significant reduction in GHG emissions. Moreover, a simulated annealing algorithm is adopted to solve large instances of this problem. The performance of the proposed algorithm is evaluated on some random instances.

Degradation of light emitting diodes: a proposed methodology

International Nuclear Information System (INIS)

Koh, Sau; Vam Driel, Willem; Zhang, G.Q.

2011-01-01

Due to their long lifetime and high efficacy, light emitting diodes have the potential to revolutionize the illumination industry. However, self heat and high environmental temperature which will lead to increased junction temperature and degradation due to electrical overstress can shorten the life of the light emitting diode. In this research, a methodology to investigate the degradation of the LED emitter has been proposed. The epoxy lens of the emitter can be modelled using simplified Eyring methods whereas an equation has been proposed for describing the degradation of the LED emitters. (semiconductor devices)

Low driving voltage blue, green, yellow, red and white organic light-emitting diodes with a simply double light-emitting structure.

Science.gov (United States)

Zhang, Zhensong; Yue, Shouzhen; Wu, Yukun; Yan, Pingrui; Wu, Qingyang; Qu, Dalong; Liu, Shiyong; Zhao, Yi

2014-01-27

Low driving voltage blue, green, yellow, red and white phosphorescent organic light-emitting diodes (OLEDs) with a common simply double emitting layer (D-EML) structure are investigated. Our OLEDs without any out-coupling schemes as well as n-doping strategies show low driving voltage, e.g. white OLED, respectively. This work demonstrates that the low driving voltages and high efficiencies can be simultaneously realized with a common simply D-EML structure.

How to emit a high-power electron beam from a magnetospheric spacecraft?

Science.gov (United States)

Delzanno, G. L.; Lucco Castello, F.; Borovsky, J.; Miars, G.; Leon, O.; Gilchrist, B. E.

2017-12-01

The idea of using a high-power electron beam to actively probe magnetic-field-line connectivity in space has been discussed since the 1970's. It could solve longstanding questions in magnetospheric/ionospheric physics by establishing causality between phenomena occurring in the magnetosphere and their image in the ionosphere. However, this idea has never been realized onboard a magnetospheric spacecraft because the tenuous magnetospheric plasma cannot provide the return current necessary to keep the charging of the spacecraft under control. Recently, Delzanno et al. [1] have proposed a spacecraft-charging mitigation scheme to enable the emission of a high-power electron beam from a magnetospheric spacecraft. It is based on the plasma contactor, i.e. a high-density neutral plasma emitted prior to and with the electron beam. The contactor acts as an ion emitter (not as an electron collector, as previously thought): a high ion current can be emitted off the quasi-spherical contactor surface, without the strong space-charge limitations typical of planar ion beams, and the electron-beam current can be successfully compensated. In this work, we will discuss our theoretical/simulation effort to improve the understanding of contactor-based ion emission. First, we will present a simple mathematical model useful for the interpretation of the results of [1]. The model is in spherical geometry and the contactor dynamics is described by only two surfaces (its quasi-neutral surface and the front of the outermost ions). It captures the results of self-consistent Particle-In-Cell (PIC) simulations with good accuracy and highlights the physics behind the charge-mitigation scheme clearly. PIC simulations connecting the 1D model to the actual geometry of the problem will be presented to obtain the scaling of the spacecraft potential varying contactor emission area. Finally, results for conditions relevant to an actual mission will also be discussed. [1] G. L. Delzanno, J. E. Borovsky

Future Vehicle Technologies : high performance transportation innovations

Energy Technology Data Exchange (ETDEWEB)

Pratt, T. [Future Vehicle Technologies Inc., Maple Ridge, BC (Canada)

2010-07-01

Battery management systems (BMS) were discussed in this presentation, with particular reference to the basic BMS design considerations; safety; undisclosed information about BMS; the essence of BMS; and Future Vehicle Technologies' BMS solution. Basic BMS design considerations that were presented included the balancing methodology; prismatic/cylindrical cells; cell protection; accuracy; PCB design, size and components; communications protocol; cost of manufacture; and expandability. In terms of safety, the presentation addressed lithium fires; high voltage; high voltage ground detection; crash/rollover shutdown; complete pack shutdown capability; and heat shields, casings, and impact protection. BMS bus bar engineering considerations were discussed along with good chip design. It was concluded that FVTs advantage is a unique skillset in automotive technology and the development of speed and cost effectiveness. tabs., figs.

High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

Science.gov (United States)

Murty, Balarama Vempaty

2000-01-01

A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

Impact of reformulated fuels on motor vehicle emissions

Science.gov (United States)

Kirchstetter, Thomas

Motor vehicles continue to be an important source of air pollution. Increased vehicle travel and degradation of emission control systems have offset some of the effects of increasingly stringent emission standards and use of control technologies. A relatively new air pollution control strategy is the reformulation of motor vehicle fuels, both gasoline and diesel, to make them cleaner- burning. Field experiments in a heavily traveled northern California roadway tunnel revealed that use of oxygenated gasoline reduced on-road emissions of carbon monoxide (CO) and volatile organic compounds (VOC) by 23 +/- 6% and 19 +/- 8%, respectively, while oxides of nitrogen (NOx) emissions were not significantly affected. The introduction of reformulated gasoline (RFG) in California led to large changes in gasoline composition including decreases in alkene, aromatic, benzene, and sulfur contents, and an increase in oxygen content. The combined effects of RFG and fleet turnover between summers 1994 and 1997 were decreases in on-road vehicle exhaust emissions of CO, non-methane VOC, and NOx by 31 +/- 5, 43 +/- 8, and 18 +/- 4%, respectively. Although it was difficult to separate the fleet turnover and RFG contributions to these changes, it was clear that the effect of RFG was greater for VOC than for NOx. The RFG effect on exhaust emissions of benzene was a 30-40% reduction. Use of RFG reduced the reactivity of liquid gasoline and gasoline headspace vapors by 23 and 19%, respectively. Increased use of methyl tert-butyl ether in gasoline led to increased concentrations of highly reactive formaldehyde and isobutene in vehicle exhaust. As a result, RFG reduced the reactivity of exhaust emissions by only about 5%. Per unit mass of fuel burned, heavy-duty diesel trucks emit about 25 times more fine particle mass and 15-20 times the number of fine particles compared to light-duty vehicles. Exhaust fine particle emissions from heavy-duty diesels contain more black carbon than particulate

Scanning of vehicles for nuclear materials

International Nuclear Information System (INIS)

Katz, J. I.

2014-01-01

Might a nuclear-armed terrorist group or state use ordinary commerce to deliver a nuclear weapon by smuggling it in a cargo container or vehicle? This delivery method would be the only one available to a sub-state actor, and it might enable a state to make an unattributed attack. Detection of a weapon or fissile material smuggled in this manner is difficult because of the large volume and mass available for shielding. Here I review methods for screening cargo containers to detect the possible presence of nuclear threats. Because of the large volume of innocent international commerce, and the cost and disruption of secondary screening by opening and inspection, it is essential that the method be rapid and have a low false-positive rate. Shielding can prevent the detection of neutrons emitted spontaneously or by induced fission. The two promising methods are muon tomography and high energy X-radiography. If they do not detect a shielded threat object they can detect the shield itself

Scanning of vehicles for nuclear materials

Energy Technology Data Exchange (ETDEWEB)

Katz, J. I. [Dept. Physics and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130 (United States)

2014-05-09

Might a nuclear-armed terrorist group or state use ordinary commerce to deliver a nuclear weapon by smuggling it in a cargo container or vehicle? This delivery method would be the only one available to a sub-state actor, and it might enable a state to make an unattributed attack. Detection of a weapon or fissile material smuggled in this manner is difficult because of the large volume and mass available for shielding. Here I review methods for screening cargo containers to detect the possible presence of nuclear threats. Because of the large volume of innocent international commerce, and the cost and disruption of secondary screening by opening and inspection, it is essential that the method be rapid and have a low false-positive rate. Shielding can prevent the detection of neutrons emitted spontaneously or by induced fission. The two promising methods are muon tomography and high energy X-radiography. If they do not detect a shielded threat object they can detect the shield itself.

Edge-enriched, porous carbon-based, high energy density supercapacitors for hybrid electric vehicles.

Science.gov (United States)

Kim, Yong Jung; Yang, Cheol-Min; Park, Ki Chul; Kaneko, Katsumi; Kim, Yoong Ahm; Noguchi, Minoru; Fujino, Takeshi; Oyama, Shigeki; Endo, Morinobu

2012-03-12

Supercapacitors can store and deliver energy by a simple charge separation, and thus they could be an attractive option to meet transient high energy density in operating fuel cells and in electric and hybrid electric vehicles. To achieve such requirements, intensive studies have been carried out to improve the volumetric capacitance in supercapacitors using various types and forms of carbons including carbon nanotubes and graphenes. However, conventional porous carbons are not suitable for use as electrode material in supercapacitors for such high energy density applications. Here, we show that edge-enriched porous carbons are the best electrode material for high energy density supercapacitors to be used in vehicles as an auxiliary powertrain. Molten potassium hydroxide penetrates well-aligned graphene layers vertically and consequently generates both suitable pores that are easily accessible to the electrolyte and a large fraction of electrochemically active edge sites. We expect that our findings will motivate further research related to energy storage devices and also environmentally friendly electric vehicles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon Dioxide Emissions as an Indicator of Reduction of Negative Externalities Related to Road Motor Vehicle Operation

Directory of Open Access Journals (Sweden)

Břetislav Andrlík

2014-01-01

Full Text Available This contribution deals with issues of carbon dioxide emissions generated by road motor vehicles in the Czech Republic and the European Union. We discuss the current need for the introduction of environmental features to the system of taxation of motor vehicles, aiming at the mitigation of harmful substances emitted into the atmosphere. The most harmful substance produced during the combustion of hydrocarbon fuels by motor vehicles is CO2, whose emissions are subsequently used as an instrument for green tax reforms in the European Union member states. In this article we define the main EU legal standards regulating harmful substances emitted into the atmosphere as a result of road motor transport. We may cite for instance the Regulation (EC No. 443/2009 setting CO2 emission performance standards for new passenger cars. The aim of the European Union is to reduce average emission values of new passenger cars sold in the EU to 130 g CO2/km by 2015 and to 95 g CO2/km by 2020. Assessment of tax on motor vehicles according to CO2 emissions shall help fulfil commitments from the Kyoto Protocol, aiming at the reduction of greenhouse gas emissions.

Network Provisioning for High Speed Vehicles Moving along Predictable Routes - Part 1: Spiderman Handover

OpenAIRE

Maureira , Juan-Carlos; Dujovne , Diego; Dalle , Olivier

2009-01-01

This report presents our on-going work on a new system designed to provide a continuous network connectivity to communicating devices located on-board a vehicle moving at ”high speed” with a predictable trajectory such as trains, subways or buses. The devices on-board the vehicle form a sub-network called the ”in-motion network”. This system we propose is composed of two parts. The mobile part, called Spiderman Device (SD), installed on the roof of the vehicle, and the fixed part is composed ...

Highly strained InGaAs/GaAs quantum wells emitting beyond 1.2 {mu}m

Energy Technology Data Exchange (ETDEWEB)

Sharma, T.K.; Zorn, M.; Zeimer, U.; Kissel, H.; Bugge, F.; Weyers, M. [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany)

2005-09-01

Highly strained In{sub x}Ga{sub 1-x}As quantum wells (QWs) with GaAs barriers emitting around 1.2 {mu}m are grown on GaAs substrates by metal organic vapour phase epitaxy (MOVPE) at low growth temperatures using conventional precursors. The effects of growth temperature, V/III ratio and growth rate on QW composition and luminescence properties are studied. The variation of indium incorporation with V/III ratio at a growth temperature of 510 C is found to be opposite to the results reported for 700 C. By an appropriate choice of the growth parameters, we could extend the room temperature photoluminescence (PL) wavelength of InGaAs/GaAs QWs up to about 1.24 {mu}m which corresponds to an average indium content of 41% in the QW. The results of the growth study were applied to broad area laser diodes emitting at 1193 nm with low threshold current densities. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Bi-layer non-doped small-molecular white organic light-emitting diodes with high colour stability

International Nuclear Information System (INIS)

Chen Shuming; Kwok, Hoi-Sing; Zhao Zujin; Tang Benzhong; Wang Zhiming; Lu Ping; Gao Zhao; Ma Yuguang

2011-01-01

Bi-layer non-doped white organic light-emitting diodes (WOLEDs) with hole-transporting layer 4-(4-(1,2,2-triphenylvinyl)phenyl)-7-(5-(4-(1,2,2-triphenylvinyl)phenyl) thiophen-2yl)benzo[c][1,2,5]thiadiazole (BTPETTD) as a red emitter and electron-transporting layer 4,4'-bis(1-phenyl-1H-phenanthro[9,10-d]imidazol-2-yl)biphenyl (DDPi) as a blue emitter are demonstrated. The blue emission is due to direct recombination of excitons in DPPi, while the red emission originates not only from the direct recombination of excitons in BTPETTD but also from a colour down-conversion process by absorbing blue emission and re-emitting red photons. The combination of blue emission and red emission yields an efficient and extremely stable white colour, regardless of driving voltages. In our demonstration, a bi-layer WOLED with an efficiency of 4.2 cd A -1 at 1000 cd m -2 , 1931 Commision International de L'Eclairage coordinates of (0.31, 0.31) and a high colour rendering index of 92 over a wide range of driving voltages is obtained.

Carbody elastic vibrations of high-speed vehicles caused by bogie hunting instability

Science.gov (United States)

Wei, Lai; Zeng, Jing; Chi, Maoru; Wang, Jianbin

2017-09-01

In particular locations of the high-speed track, the worn wheel profile matched up with the worn rail profile will lead to an extremely high-conicity wheel-rail contact. Consequently, the bogie hunting instability arises, which further results in the so-called carbody shaking phenomenon. In this paper, the carbody elastic vibrations of a high-speed vehicle in service are firstly introduced. Modal tests are conducted to identity the elastic modes of the carbody. The ride comfort and running safety indices for the tested vehicle are evaluated. The rigid-flexible coupling dynamic model for the high-speed passenger car is then developed by using the FE and MBS coupling approach. The rail profiles in those particular locations are measured and further integrated into the simulation model to reproduce the bogie hunting and carbody elastic vibrations. The effects of wheel and rail wear on the vehicle system response, e.g. wheelset bifurcation graph and carbody vibrations, are studied. Two improvement measures, including the wheel profile modification and rail grinding, are proposed to provide possible solutions. It is found that the wheel-rail contact conicity can be lowered by decreasing wheel flange thickness or grinding rail corner, which is expected to improve the bogie hunting stability under worn rail and worn wheel conditions. The carbody elastic vibrations caused by bogie hunting instability can be further restrained.

Modeling speed and width parameters of vehicle tires for prediction of the reduction in vehicle noise pollution

Directory of Open Access Journals (Sweden)

Amir Esmael Forouhid

2016-06-01

Full Text Available Introduction: Safe driving requires the ability of the driver to receive the messages and complying with them. The most significant consequences of noise pollution are on the human auditory system. Disorders in the auditory system can have harmful side effects for human health. By reducing this kind of pollution in large cities, the quality of life, which is one of the biggest goals of the governments, can be considerably increased. Hence, in the present research, some parameters of vehicle tires were examined as a source of noise pollution, and the results can be taken into consideration in noise pollution reduction. Material and Method: Several vehicles with different tire width were selected for measuring sound level. The sound levels were measured for moving vehicles with the use of the Statistical Pass By Method (SPB, ISO 11819-1. Following sound level measurements for moving vehicles and by considering tire width, mathematical model of noise level was predicted on the basis of the obtained information and by usage of SPSS program and considering vehicle tire parameters. Result: The result of this study showed that the vehicle speed and tire width can affect different sound levels emitted by moving tire on road surface. The average speed of vehicles can play an important role in the noise pollution. By increasing speed, rotation of the the tires on the asphalt is increased, as it is a known factors for noise pollution. Moreover, changing the speed of vehicles is accompanied with abnormal sounds of vehicle engine. According to regression model analysis, the obtained value of R2 for the model is 0.8367 which represents the coefficient of determination. Conclusion: The results suggest the main role of the vehicle speed and tire width in increasing the noise reaches to the drivers and consequent noise pollution, which demonstrates the necessity for noise control measures. According to the obtained model, it is understood that changes in noise

Carbonaceous species emitted from handheld two-stroke engines

Science.gov (United States)

Volckens, John; Olson, David A.; Hays, Michael D.

Small, handheld two-stroke engines used for lawn and garden work (e.g., string trimmers, leaf blowers, etc.) can emit a variety of potentially toxic carbonaceous air pollutants. Yet, the emissions effluents from these machines go largely uncharacterized, constraining the proper development of human exposure estimates, emissions inventories, and climate and air quality models. This study samples and evaluates chemical pollutant emissions from the dynamometer testing of six small, handheld spark-ignition engines—model years 1998-2002. Four oil-gas blends were tested in each engine in duplicate. Emissions of carbon dioxide, carbon monoxide, and gas-phase hydrocarbons were predominant, and the PM emitted was organic matter primarily. An ANOVA model determined that engine type and control tier contributed significantly to emissions variations across all identified compound classes; whereas fuel blend was an insignificant variable accounting for engines were generally intermediate in magnitude compared with other gasoline-powered engines, numerous compounds traditionally viewed as motor vehicle markers are also present in small engine emissions in similar relative proportions. Given that small, handheld two-stroke engines used for lawn and garden work account for 5-10% of total US emissions of CO, CO 2, NO x, HC, and PM 2.5, source apportionment models and human exposure studies need to consider the effect of these small engines on ambient concentrations in air polluted environments.

Pulsed operation of high-power light emitting diodes for imaging flow velocimetry

International Nuclear Information System (INIS)

Willert, C; Klinner, J; Moessner, S; Stasicki, B

2010-01-01

High-powered light emitting diodes (LED) are investigated for possible uses as light sources in flow diagnostics, in particular, as an alternative to laser-based illumination in particle imaging flow velocimetry in side-scatter imaging arrangements. Recent developments in solid state illumination resulted in mass-produced LEDs that provide average radiant power in excess of 10 W. By operating these LEDs with short duration, pulsed currents that are considerably beyond their continuous current damage threshold, light pulses can be generated that are sufficient to illuminate and image micron-sized particles in flow velocimetry. Time-resolved PIV measurements in water at a framing rate of 2kHz are presented. The feasibility of LED-based PIV measurements in air is also demonstrated

Exciplex-Forming Co-Host-Based Red Phosphorescent Organic Light-Emitting Diodes with Long Operational Stability and High Efficiency.

Science.gov (United States)

Lee, Jeong-Hwan; Shin, Hyun; Kim, Jae-Min; Kim, Kwon-Hyeon; Kim, Jang-Joo

2017-02-01

The use of exciplex forming cohosts and phosphors incredibly boosts the efficiency of organic light-emitting diodes (OLEDs) by providing a barrier-free charge injection into an emitting layer and a broad recombination zone. However, most of the efficient OLEDs based on the exciplex forming cohosts has suffered from the short operational lifetime. Here, we demonstrated phosphorescent OLEDs (PhOLEDs) having both high efficiency and long lifetime by using a new exciplex forming cohost composed of N,N'-diphenyl-N,N'-bis(1,1'-biphenyl)-4,4'-diamine (NPB) and (1,3,5-triazine-2,4,6-triyl)tris(benzene-3,1-diyl))tris(diphenylphosphine oxide) (PO-T2T). The red-emitting PhOLEDs using the exciplex forming cohost achieved a maximum external quantum efficiency (EQE) of 34.1% and power efficiency of 62.2 lm W 1- with low operating voltages and low efficiency roll-offs. More importantly, the device demonstrated a long lifetime around 2249 h from 1000 cd m -2 to 900 cd m -2 (LT 90 ) under a continuous flow of constant current. The efficiencies of the devices are the highest for red OLEDs with an LT 90 > 1000 h.

Assessment of capacity support and scattering in experimental high speed vehicle to vehicle MIMO links

DEFF Research Database (Denmark)

Eggers, Patrick Claus F.; Brown, Tim; Olesen, Kim

2007-01-01

Preliminary results on the use of the vehicle to vehicle MIMO channel in a rural highway environment are presented. This is looked at both in terms of the available spatial multiplexing through singular value decomposition and also angular distribution within the channel. Results indicate a strong...... predominant line of sight link in general while instances of scattering from other vehicles will cause changes in the Doppler spectrum as well as beamforming jitter....

3.4-Inch Quarter High Definition Flexible Active Matrix Organic Light Emitting Display with Oxide Thin Film Transistor

Science.gov (United States)

Hatano, Kaoru; Chida, Akihiro; Okano, Tatsuya; Sugisawa, Nozomu; Inoue, Tatsunori; Seo, Satoshi; Suzuki, Kunihiko; Oikawa, Yoshiaki; Miyake, Hiroyuki; Koyama, Jun; Yamazaki, Shunpei; Eguchi, Shingo; Katayama, Masahiro; Sakakura, Masayuki

2011-03-01

In this paper, we report a 3.4-in. flexible active matrix organic light emitting display (AMOLED) display with remarkably high definition (quarter high definition: QHD) in which oxide thin film transistors (TFTs) are used. We have developed a transfer technology in which a TFT array formed on a glass substrate is separated from the substrate by physical force and then attached to a flexible plastic substrate. Unlike a normal process in which a TFT array is directly fabricated on a thin plastic substrate, our transfer technology permits a high integration of high performance TFTs, such as low-temperature polycrystalline silicon TFTs (LTPS TFTs) and oxide TFTs, on a plastic substrate, because a flat, rigid, and thermally-stable glass substrate can be used in the TFT fabrication process in our transfer technology. As a result, this technology realized an oxide TFT array for an AMOLED on a plastic substrate. Furthermore, in order to achieve a high-definition AMOLED, color filters were incorporated in the TFT array and a white organic light-emitting diode (OLED) was combined. One of the features of this device is that the whole body of the device can be bent freely because a source driver and a gate driver can be integrated on the substrate due to the high mobility of an oxide TFT. This feature means “true” flexibility.

White organic light-emitting diodes with 9, 10-bis (2-naphthyl) anthracene

International Nuclear Information System (INIS)

Guan Yunxia; Niu Lianbin

2009-01-01

White organic light-emitting diodes were fabricated by 9, 10-bis (2-naphthyl) anthracene (ADN) doped with Rubrene with a structure of ITO/copper phthalocyanine (CuPc) / NPB /ADN: Rubrene /Alq 3 /CsF/Mg:Ag/Ag. Multilayer organic devices using AND and Rubrene as an emitting layer produced white emissions with good chromaticity and luminous efficiency as high as 5.93 cd/A. This performance can be explained by Foerster energy transfer from the blue-emitting host to the orange-emitting dopant.

Low-voltage and high-efficiency white organic light emitting devices with carrier balance

International Nuclear Information System (INIS)

Wei Fuxiang; Huang, Y.; Fang, L.

2010-01-01

White organic light emitting devices with the structure of ITO/m-MTDATA:x%4F-TCNQ/NPB/TBADN:EBDP:DCJTB/Bphen:Liq/LiF/Al have been demonstrated in this paper. High-mobility m-MTDATA:4F-TCNQ is added into the region between ITO and NBP to increase hole injection and transport. The high-mobility Bphen:Liq layer is added into the region between cathode and emission layers to lower cathode barrier and facilitate carrier injection. In the meanwhile, an effective carrier balance (number of holes is equal to number of electrons) between holes and electrons is considered to be one of the most important factors for improving OLEDs. During the experiment, by modulating the doping concentration of 4F-TCNQ, we can control hole injection and transport to make the carriers reach a high-level balance. The maximum current efficiency and power efficiency of devices were 9.3 cd/A and 4.6 lm/A, respectively.

Hybrid vehicle control

Science.gov (United States)

Shallvari, Iva; Velnati, Sashidhar; DeGroot, Kenneth P.

2015-07-28

A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

Highly Efficient Visible Colloidal Lead-Halide Perovskite Nanocrystal Light-Emitting Diodes

Science.gov (United States)

Yan, Fei; Xing, Jun; Xing, Guichuan; Quan, Lina; Tan, Swee Tiam; Zhao, Jiaxin; Su, Rui; Zhang, Lulu; Chen, Shi; Zhao, Yawen; Huan, Alfred; Sargent, Edward H.; Xiong, Qihua; Demir, Hilmi Volkan

2018-05-01

Lead-halide perovskites have been attracting attention for potential use in solid-state lighting. Following the footsteps of solar cells, the field of perovskite light-emitting diodes (PeLEDs) has been growing rapidly. Their application prospects in lighting, however, remain still uncertain due to a variety of shortcomings in device performance including their limited levels of luminous efficiency achievable thus far. Here we show high-efficiency PeLEDs based on colloidal perovskite nanocrystals (PeNCs) synthesized at room temperature possessing dominant first-order excitonic radiation (enabling a photoluminescence quantum yield of 71% in solid film), unlike in the case of bulk perovskites with slow electron-hole bimolecular radiative recombination (a second-order process). In these PeLEDs, by reaching charge balance in the recombination zone, we find that the Auger nonradiative recombination, with its significant role in emission quenching, is effectively suppressed in low driving current density range. In consequence, these devices reach a record high maximum external quantum efficiency of 12.9% reported to date and an unprecedentedly high power efficiency of 30.3 lm W-1 at luminance levels above 1000 cd m-2 as required for various applications. These findings suggest that, with feasible levels of device performance, the PeNCs hold great promise for their use in LED lighting and displays.

Highly efficient blue organic light emitting device using indium-free transparent anode Ga:ZnO with scalability for large area coating

International Nuclear Information System (INIS)

Wang Liang; Matson, Dean W.; Polikarpov, Evgueni; Swensen, James S.; Bonham, Charles C.; Cosimbescu, Lelia; Gaspar, Daniel J.; Padmaperuma, Asanga B.; Berry, Joseph J.; Ginley, David S.

2010-01-01

Organic light emitting devices have been achieved with an indium-free transparent anode, Ga doped ZnO (GZO). A large area coating technique was used (RF magnetron sputtering) to deposit the GZO films onto glass. The respective organic light emitting devices exhibited an operational voltage of 3.7 V, an external quantum efficiency of 17%, and a power efficiency of 39 lm/W at a current density of 1 mA/cm 2 . These parameters are well within acceptable standards for blue OLEDs to generate a white light with high enough brightness for general lighting applications. It is expected that high-efficiency, long-lifetime, large area, and cost-effective white OLEDs can be made with these indium-free anode materials.

Very high efficiency phosphorescent organic light-emitting devices by using rough indium tin oxide

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yingjie; Aziz, Hany, E-mail: h2aziz@uwaterloo.ca [Department of Electrical and Computer Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1 (Canada)

2014-07-07

The efficiency of organic light-emitting devices (OLEDs) is shown to significantly depend on the roughness of the indium tin oxide (ITO) anode. By using rougher ITO, light trapped in the ITO/organic wave-guided mode can be efficiently extracted, and a light outcoupling enhancement as high as 40% is achieved. Moreover, contrary to expectations, the lifetime of OLEDs is not affected by ITO roughness. Finally, an OLED employing rough ITO anode that exhibits a current efficiency of 56 cd/A at the remarkably high brightness of 10{sup 5} cd/m{sup 2} is obtained. This represents the highest current efficiency at such high brightness to date for an OLED utilizing an ITO anode, without any external light outcoupling techniques. The results demonstrate the significant efficiency benefits of using ITO with higher roughness in OLEDs.

Very high efficiency phosphorescent organic light-emitting devices by using rough indium tin oxide

International Nuclear Information System (INIS)

Zhang, Yingjie; Aziz, Hany

2014-01-01

The efficiency of organic light-emitting devices (OLEDs) is shown to significantly depend on the roughness of the indium tin oxide (ITO) anode. By using rougher ITO, light trapped in the ITO/organic wave-guided mode can be efficiently extracted, and a light outcoupling enhancement as high as 40% is achieved. Moreover, contrary to expectations, the lifetime of OLEDs is not affected by ITO roughness. Finally, an OLED employing rough ITO anode that exhibits a current efficiency of 56 cd/A at the remarkably high brightness of 10 5  cd/m 2 is obtained. This represents the highest current efficiency at such high brightness to date for an OLED utilizing an ITO anode, without any external light outcoupling techniques. The results demonstrate the significant efficiency benefits of using ITO with higher roughness in OLEDs.

Highly efficient deep-blue organic light emitting diode with a carbazole based fluorescent emitter

Science.gov (United States)

Sahoo, Snehasis; Dubey, Deepak Kumar; Singh, Meenu; Joseph, Vellaichamy; Thomas, K. R. Justin; Jou, Jwo-Huei

2018-04-01

High efficiency deep-blue emission is essential to realize energy-saving, high-quality display and lighting applications. We demonstrate here a deep-blue organic light emitting diode using a novel carbazole based fluorescent emitter 7-[4-(diphenylamino)phenyl]-9-(2-ethylhexyl)-9H-carbazole-2-carbonitrile (JV234). The solution processed resultant device shows a maximum luminance above 1,750 cd m-2 and CIE coordinates (0.15,0.06) with a 1.3 lm W-1 power efficiency, 2.0 cd A-1 current efficiency, and 4.1% external quantum efficiency at 100 cd m-2. The resulting deep-blue emission enables a greater than 100% color saturation. The high efficiency may be attributed to the effective host-to-guest energy transfer, suitable device architecture facilitating balanced carrier injection and low doping concentration preventing efficiency roll-off caused by concentration quenching.

Taking Over Control From Highly Automated Vehicles in Complex Traffic Situations: The Role of Traffic Density.

Science.gov (United States)

Gold, Christian; Körber, Moritz; Lechner, David; Bengler, Klaus

2016-06-01

The aim of this study was to quantify the impact of traffic density and verbal tasks on takeover performance in highly automated driving. In highly automated vehicles, the driver has to occasionally take over vehicle control when approaching system limits. To ensure safety, the ability of the driver to regain control of the driving task under various driving situations and different driver states needs to be quantified. Seventy-two participants experienced takeover situations requiring an evasive maneuver on a three-lane highway with varying traffic density (zero, 10, and 20 vehicles per kilometer). In a between-subjects design, half of the participants were engaged in a verbal 20-Questions Task, representing speaking on the phone while driving in a highly automated vehicle. The presence of traffic in takeover situations led to longer takeover times and worse takeover quality in the form of shorter time to collision and more collisions. The 20-Questions Task did not influence takeover time but seemed to have minor effects on the takeover quality. For the design and evaluation of human-machine interaction in takeover situations of highly automated vehicles, the traffic state seems to play a major role, compared to the driver state, manipulated by the 20-Questions Task. The present results can be used by developers of highly automated systems to appropriately design human-machine interfaces and to assess the driver's time budget for regaining control. © 2016, Human Factors and Ergonomics Society.

Flight simulation program for high altitude long endurance unmanned vehicle; Kokodo mujinki no hiko simulation program

Energy Technology Data Exchange (ETDEWEB)

Suzuki, H.; Hashidate, M. [National Aerospace Laboratory, Tokyo (Japan)

1995-11-01

An altitude of about 20 km has the atmospheric density too dilute for common aircraft, and the air resistance too great for satellites. Attention has been drawn in recent years on a high-altitude long-endurance unmanned vehicle that flies at this altitude for a long period of time to serve as a wave relaying base and perform traffic control. Therefore, a development was made on a flight simulation program to evaluate and discuss the guidance and control laws for the high-altitude unmanned vehicle. Equations of motion were derived for three-dimensional six freedom and three-dimensional three freedom. Aerodynamic characteristics of an unmanned vehicle having a Rectenna wing were estimated, and formulation was made according to the past research results on data of winds that the unmanned vehicle is anticipated to encounter at an altitude of 20 km. Noticing the inside of a horizontal plane, a proposal was given on a guidance law that follows a given path. A flight simulation was carried out to have attained a prospect that the unmanned vehicle may be enclosed in a limited space even if the vehicle is encountered with a relatively strong wind. 18 refs., 20 figs., 1 tab.

White organic light-emitting diodes with 9, 10-bis (2-naphthyl) anthracene

Energy Technology Data Exchange (ETDEWEB)

Guan Yunxia; Niu Lianbin [Key Laboratory of Optical Engineering, College of Physics and Information Technology, Chongqing Normal University, Chongqing 400047 (China)], E-mail: gyxybsy@126.com, E-mail: niulb03@126.com

2009-03-01

White organic light-emitting diodes were fabricated by 9, 10-bis (2-naphthyl) anthracene (ADN) doped with Rubrene with a structure of ITO/copper phthalocyanine (CuPc) / NPB /ADN: Rubrene /Alq{sub 3} /CsF/Mg:Ag/Ag. Multilayer organic devices using AND and Rubrene as an emitting layer produced white emissions with good chromaticity and luminous efficiency as high as 5.93 cd/A. This performance can be explained by Foerster energy transfer from the blue-emitting host to the orange-emitting dopant.

High power cascade diode lasers emitting near 2 μm

Energy Technology Data Exchange (ETDEWEB)

Hosoda, Takashi; Feng, Tao; Shterengas, Leon, E-mail: leon.shterengas@stonybrook.edu; Kipshidze, Gela; Belenky, Gregory [State University of New York at Stony Brook, Stony Brook, New York 11794 (United States)

2016-03-28

High-power two-stage cascade GaSb-based type-I quantum well diode lasers emitting near 2 μm were designed and fabricated. Coated devices with cavity length of 3 mm generated about 2 W of continuous wave power from 100-μm-wide aperture at the current of 6 A. The power conversion efficiency peaked at 20%. Carrier recycling between quantum well gain stages was realized using band-to-band tunneling in GaSb/AlSb/InAs heterostructure complemented with optimized electron and hole injector regions. Design optimization eliminated parasitic optical absorption and thermionic emission, and included modification of the InAs quantum wells of electron and composition and doping profile of hole injectors. Utilization of the cascade pumping scheme yielded 2 μm lasers with improved output power and efficiency compared to existing state-of-the-art diodes.

Vertical Vibration Characteristics of a High-Temperature Superconducting Maglev Vehicle System

Science.gov (United States)

Jiang, Jing; Li, Ke Cai; Zhao, Li Feng; Ma, Jia Qing; Zhang, Yong; Zhao, Yong

2013-06-01

The vertical vibration characteristics of a high-temperature superconducting maglev vehicle system are investigated experimentally. The displacement variations of the maglev vehicle system are measured with different external excitation frequency, in the case of a certain levitation gap. When the external vibration frequency is low, the amplitude variations of the response curve are small. With the increase of the vibration frequency, chaos status can be found. The resonance frequencies with difference levitation gap are also investigated, while the external excitation frequency range is 0-100 Hz. Along with the different levitation gap, resonance frequency is also different. There almost is a linear relationship between the levitation gap and the resonance frequency.

An assessment of the real-world driving gaseous emissions from a Euro 6 light-duty diesel vehicle using a portable emissions measurement system (PEMS)

Science.gov (United States)

Luján, José M.; Bermúdez, Vicente; Dolz, Vicente; Monsalve-Serrano, Javier

2018-02-01

Recent investigations demonstrated that real-world emissions usually exceed the levels achieved in the laboratory based type approval processes. By means of on-board emissions measurements, it has been shown that nitrogen oxides emitted by diesel engines substantially exceed the limit imposed by the Euro 6 regulation. Thus, with the aim of complementing the worldwide harmonized light vehicles test cycle, the real driving emissions cycle will be introduced after 1 September 2017 to regulate the vehicle emissions in real-world driving situations. This paper presents on-board gaseous emissions measurements from a Euro 6 light-duty diesel vehicle in a real-world driving route using a portable emissions measurement system. The test route characteristics follow the requirements imposed by the RDE regulation. The analysis of the raw emissions results suggests that the greatest amount of nitrogen oxides and nitrogen dioxide are emitted during the urban section of the test route, confirming that lower speeds with more accelerations and decelerations lead to higher nitrogen oxides emissions levels than constant high speeds. Moreover, the comparison of the two calculation methods proposed by the real driving emissions regulation has revealed emissions rates differences ranging from 10% to 45% depending on the pollutant emission and the trip section considered (urban or total). Thus, the nitrogen oxides emissions conformity factor slightly varies from one method to the other.

Smart Sensor Based Obstacle Detection for High-Speed Unmanned Surface Vehicle

DEFF Research Database (Denmark)

Hermann, Dan; Galeazzi, Roberto; Andersen, Jens Christian

2015-01-01

This paper describes an obstacle detection system for a high-speed and agile unmanned surface vehicle (USV), running at speeds up to 30 m/s. The aim is a real-time and high performance obstacle detection system using both radar and vision technologies to detect obstacles within a range of 175 m. ...... performance using sensor fusion of radar and computer vision....

A robust yellow-emitting metallophosphor with electron-injection/-transporting traits for highly efficient white organic light-emitting diodes.

Science.gov (United States)

Zhou, Guijiang; Yang, Xiaolong; Wong, Wai-Yeung; Wang, Qi; Suo, Si; Ma, Dongge; Feng, Jikang; Wang, Lixiang

2011-10-24

With the aim of endowing triplet emitters in the development of organic light-emitting devices (OLEDs) with electron-injection/-transporting (EI/ET) features, the phenylsulfonyl moiety was introduced into the phenyl ring of a 2-phenylpyridine (Hppy) ligand and the yellow phosphorescent heteroleptic iridium(III) complex 1 was developed. It was shown that the SO(2)Ph unit could provide EI/ET character to 1, as indicated from both electrochemical and computational data. Complex 1 is a promising yellow-emitting material for both monochromatic OLEDs and white OLEDs (WOLEDs). The outstanding electronic traits associated with 1, coupled with careful device design, afforded very attractive electroluminescent performances for two-element WOLEDs, including a low turn-on voltage of less than 3.7 V, a maximum brightness of 48,000 cd m(-2), an external quantum efficiency of 13.0%, a luminance efficiency of 34.7 cd A(-1), and a power efficiency of 24.3 Lm W(-1). In addition, a good color rendering index (CRI) of about 74, a stable white color with a Commission Internationale de L'Eclairage (CIE(x,y)) variation of Δ(x, y) OLED research. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Backward emitted high-energy neutrons in hard reactions of p and π+ on carbon

Science.gov (United States)

Malki, A.; Alster, J.; Asryan, G.; Averichev, Y.; Barton, D.; Baturin, V.; Bukhtoyarova, N.; Carroll, A.; Heppelmann, S.; Kawabata, T.; Leksanov, A.; Makdisi, Y.; Minina, E.; Navon, I.; Nicholson, H.; Ogawa, A.; Panebratsev, Yu.; Piasetzky, E.; Schetkovsky, A.; Shimanskiy, S.; Tang, A.; Watson, J. W.; Yoshida, H.; Zhalov, D.

2002-01-01

Beams of protons and pions of 5.9 GeV/c were incident on a C target. Neutrons emitted into the backward hemisphere, in the laboratory system, were detected in (triple) coincidence with two emerging particles of tranverse momenta pt>0.6 GeV/c. We determined that for (46.5+/-3.7)% of the proton-induced events and for (40.8+/-4.5)% of the pion-induced events with the two high-pt particles, there is also at least one backward emitted neutron with momentum greater than 0.32 GeV/c. This observation is in sharp contrast to a well- established universal pattern from a large variety of earlier inclusive measurements with hadrons, electrons, photons, neutrinos, and antineutrinos where the probability for backward nucleon emission was in the 5 to 10 % range. We present also a measurement of the momentum spectra for the backward going neutrons. The spectra have the same universal shape observed in the inclusive reactions. We speculate that the enhanced backward neutron emission in this semi-inclusive region could be an indication for a strong dependence of the cross section on the squared total center-of-mass energy (s) and for the importance of short-range nucleon-nucleon correlations.

Side-emitting high-power LEDs and their application in illumination

Science.gov (United States)

West, Robert S.

2002-11-01

Due to the rapid increase in flux performance from High Power LED's, illumination is an exciting growth market for solid state lighting. Today a white LED is 100+ Lm per device. This is approximately an order of magnitude below the kLm metric used for illumination applications. The radiation pattern from the LED is key in increasing the usable flux resulting in improved systems optical performance. This advancement in radiation pattern will allow new market opportunities, which were not yet feasible. In the future this effect of usable lumens will become more important as the flux per package increases. The radiation pattern of the LEDs can be controlled to optimize performance, appearance, and shape of the secondary optics. This advantage is unique to LEDs and can greatly improve system performance, control, and cosmetic appeal for the application. This paper will review the side emitting lens design, the integrated performance of this technology to secondary optics and how the Luxeon side emitter enables improved performance by creating more useable lumens.

Solution-Processed Phosphorescent Organic Light-Emitting Diodes with Ultralow Driving Voltage and Very High Power Efficiency

OpenAIRE

Wang, Shumeng; Wang, Xingdong; Yao, Bing; Zhang, Baohua; Ding, Junqiao; Xie, Zhiyuan; Wang, Lixiang

2015-01-01

To realize power efficient solution-processed phosphorescent organic light-emitting diodes (s-PhOLEDs), the corresponding high driving voltage issue should be well solved. To solve it, efforts have been devoted to the exploitation of novel host or interfacial materials. However, the issues of charge trapping of phosphor and/or charge injection barrier are still serious, largely restraining the power efficiency (PE) levels. Herein, with the utilization of an exciplex-forming couple 4, 4?, 4? -...

High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

Directory of Open Access Journals (Sweden)

S. Zhang

2016-08-01

Full Text Available Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet – Macau, EMBEV–Macau, this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other

Effect of regional grid mix, driving patterns and climate on the comparative carbon footprint of gasoline and plug-in electric vehicles in the United States

Science.gov (United States)

Yuksel, Tugce; Tamayao, Mili-Ann M.; Hendrickson, Chris; Azevedo, Inês M. L.; Michalek, Jeremy J.

2016-04-01

We compare life cycle greenhouse gas (GHG) emissions from several light-duty passenger gasoline and plug-in electric vehicles (PEVs) across US counties by accounting for regional differences due to marginal grid mix, ambient temperature, patterns of vehicle miles traveled (VMT), and driving conditions (city versus highway). We find that PEVs can have larger or smaller carbon footprints than gasoline vehicles, depending on these regional factors and the specific vehicle models being compared. The Nissan Leaf battery electric vehicle has a smaller carbon footprint than the most efficient gasoline vehicle (the Toyota Prius) in the urban counties of California, Texas and Florida, whereas the Prius has a smaller carbon footprint in the Midwest and the South. The Leaf is lower emitting than the Mazda 3 conventional gasoline vehicle in most urban counties, but the Mazda 3 is lower emitting in rural Midwest counties. The Chevrolet Volt plug-in hybrid electric vehicle has a larger carbon footprint than the Prius throughout the continental US, though the Volt has a smaller carbon footprint than the Mazda 3 in many urban counties. Regional grid mix, temperature, driving conditions, and vehicle model all have substantial implications for identifying which technology has the lowest carbon footprint, whereas regional patterns of VMT have a much smaller effect. Given the variation in relative GHG implications, it is unlikely that blunt policy instruments that favor specific technology categories can ensure emission reductions universally.

Effect of regional grid mix, driving patterns and climate on the comparative carbon footprint of gasoline and plug-in electric vehicles in the United States

International Nuclear Information System (INIS)

Yuksel, Tugce; Michalek, Jeremy J; Tamayao, Mili-Ann M; Hendrickson, Chris; Azevedo, Inês M L

2016-01-01

We compare life cycle greenhouse gas (GHG) emissions from several light-duty passenger gasoline and plug-in electric vehicles (PEVs) across US counties by accounting for regional differences due to marginal grid mix, ambient temperature, patterns of vehicle miles traveled (VMT), and driving conditions (city versus highway). We find that PEVs can have larger or smaller carbon footprints than gasoline vehicles, depending on these regional factors and the specific vehicle models being compared. The Nissan Leaf battery electric vehicle has a smaller carbon footprint than the most efficient gasoline vehicle (the Toyota Prius) in the urban counties of California, Texas and Florida, whereas the Prius has a smaller carbon footprint in the Midwest and the South. The Leaf is lower emitting than the Mazda 3 conventional gasoline vehicle in most urban counties, but the Mazda 3 is lower emitting in rural Midwest counties. The Chevrolet Volt plug-in hybrid electric vehicle has a larger carbon footprint than the Prius throughout the continental US, though the Volt has a smaller carbon footprint than the Mazda 3 in many urban counties. Regional grid mix, temperature, driving conditions, and vehicle model all have substantial implications for identifying which technology has the lowest carbon footprint, whereas regional patterns of VMT have a much smaller effect. Given the variation in relative GHG implications, it is unlikely that blunt policy instruments that favor specific technology categories can ensure emission reductions universally. (letter)

The effects of high frequency current ripple on electric vehicle battery performance

International Nuclear Information System (INIS)

Uddin, Kotub; Moore, Andrew D.; Barai, Anup; Marco, James

2016-01-01

Highlights: • Experimental study into the impact of current ripple on li-ion battery degradation. • 15 cells exercised with 1200 cycles coupled AC–DC signals, at 5 frequencies. • Results highlight a greater spread of degradation for cells exposed to AC excitation. • Implications for BMS control, thermal management and system integration. - Abstract: The power electronic subsystems within electric vehicle (EV) powertrains are required to manage both the energy flows within the vehicle and the delivery of torque by the electrical machine. Such systems are known to generate undesired electrical noise on the high voltage bus. High frequency current oscillations, or ripple, if unhindered will enter the vehicle’s battery system. Real-world measurements of the current on the high voltage bus of a series hybrid electric vehicle (HEV) show that significant current perturbations ranging from 10 Hz to in excess of 10 kHz are present. Little is reported within the academic literature about the potential impact on battery system performance and the rate of degradation associated with exposing the battery to coupled direct current (DC) and alternating currents (AC). This paper documents an experimental investigation that studies the long-term impact of current ripple on battery performance degradation. Initial results highlight that both capacity fade and impedance rise progressively increase as the frequency of the superimposed AC current increases. A further conclusion is that the spread of degradation for cells cycled with a coupled AC–DC signal is considerably more than for cells exercised with a traditional DC waveform. The underlying causality for this degradation is not yet understood. However, this has important implications for the battery management system (BMS). Increased variations in cell capacity and impedance will cause differential current flows and heat generation within the battery pack that if not properly managed will further reduce battery life

CO2 laser photoacoustic detection of ammonia emitted by ceramic industries.

Science.gov (United States)

Sthel, M S; Schramm, D U; Lima, G R; Carneiro, L; Faria, R T; Castro, M P P; Alexandre, J; Toledo, R; Silva, M G; Vargas, H

2011-01-01

A homemade photoacoustic spectrometer has been constructed for monitoring gas emission from several sources. Numerous air pollutant gases are emitted exhaust of industries, vehicles and power plants. The photoacoustic technique is extremely sensitive and selective in detecting various gases. This work focuses on the gas emitted by the ceramic industry in northern Rio de Janeiro State in Brazil, the ceramic industry plays a remarkable role in the economy activity of this region, in recent years, this region developed into a significant red ceramic complex. The potential impact on the atmospheric environment of the region due to gaseous pollutant emissions from these anthropogenic sources needs to be evaluated. In this work we identified NH3 present in the samples collected in the kiln of a ceramic plant, in the concentration range of 33-52 ppmV. The ammonia gas present in our collected samples might come from the excess nitrogen in the manure soil from where the ceramic material was extracted. This soil was used for the sugarcane culture which is another important economic activity of this region. Copyright © 2010 Elsevier B.V. All rights reserved.

White emission from nano-structured top-emitting organic light-emitting diodes based on a blue emitting layer

International Nuclear Information System (INIS)

Hyun, Woo Jin; Park, Jung Jin; Park, O Ok; Im, Sang Hyuk; Chin, Byung Doo

2013-01-01

We demonstrated that white emission can be obtained from nano-structured top-emitting organic light-emitting diodes (TEOLEDs) based on a blue emitting layer (EML). The nano-structured TEOLEDs were fabricated on nano-patterned substrates, in which both optical micro-cavity and scattering effects occur simultaneously. Due to the combination of these two effects, the electroluminescence spectra of the nano-structured device with a blue EML exhibited not only blue but also yellow colours, which corresponded to the intrinsic emission of the EML and the resonant emission of the micro-cavity effect. Consequently, it was possible to produce white emission from nano-structured TEOLEDs without employing a multimode micro-cavity. The intrinsic emission wavelength can be varied by altering the dopant used for the EML. Furthermore, the emissive characteristics turned out to be strongly dependent on the nano-pattern sizes of the nano-structured devices. (paper)

Focus group testing for the vehicle scrappage program : final report

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-03-15

Canada's national vehicle scrappage program was designed to reduce greenhouse gas (GHG) and smog-forming emissions by removing personal vehicles with model years of 1995 and older from Canadian road systems. The program will also promote sustainable transportation alternatives and recycling programs to prevent the release of other toxic substances into the environment. Incentives designed to encourage Canadians to scrap older vehicles may include cash incentives and rebates towards the purchase of a new vehicle, free transit passes, and other options designed to support sustainable transportation. This paper discussed a research program conducted to assess target audience responses to the programs and its proposed incentives. The survey was conducted with a series of 20 focus groups located in major cities across Canada. Sessions were comprised of between 6 to 10 participants from lower-income and higher-income households. All groups responded negatively to both the overall policy as well as to specific program elements. The study showed that most participants were not aware that older vehicles emit significantly higher levels of harmful emissions. The research audience did not understand distinctions between smog-producing emissions and GHG emissions. Participants also believed that personal vehicles had a minor negative impact on the environment compared to trucks, industry, and vehicle fleets. Participants felt a sense of pride in the ways in which they had maintained their older vehicles, and also perceived them as safer than newer vehicles. It was concluded that many participants were resistant to facts presented to them about older vehicles, and felt that the incentives were insufficient to trigger action. The effectiveness of advertising materials designed to promote the program was also assessed. 3 tabs., 9 figs.

Gas-phase polynuclear aromatic hydrocarbons (PAH) in vehicle exhaust: A method for collection and analysis

International Nuclear Information System (INIS)

Seigl, W.O.; Chladek, E.

1990-01-01

Gas-phase polynuclear aromatic hydrocarbons (PAH) are emitted at low levels in vehicle exhaust compared to other hydrocarbon emissions. A method has been developed involving the trapping of gas phase emissions on Tenax, a macrorecticular porous polymer, followed by thermal desorption onto a capillary gas chromatography column. Gas chromatography/mass spectrometry (GC/MS) was used for the chemical analysis. A detection limit of 0.05 ng was achieved for several gas-phase PAH. This high sensitivity enables the speciation and quantitation of gas-phase PAH collected from a dilution tube during standard driving (test) cycles. The method was demonstrated for the analysis of 9 PAH in the exhaust from a 1987 vehicle (with and without catalyst) during the hot start transient phase of the EPA urban dynamometer driving schedule. The PAH measured include naphthalene, 2-methyl- and 1-methylnaphthalene, biphenyl, fluorene, phenanthrene, anthracene, fluoranthene and pyrene. The four most abundant PAH observed are naphthalene, 2-methyl and 1-methylnaphthalene, and biphenyl, in that order

High Bandwidth Communications Links Between Heterogeneous Autonomous Vehicles Using Sensor Network Modeling and Extremum Control Approaches

Science.gov (United States)

2008-12-01

In future network-centric warfare environments, teams of autonomous vehicles will be deployed in a coorperative manner to conduct wide-area...of data back to the command station, autonomous vehicles configured with high bandwidth communication system are positioned between the command

Recombination zone in white organic light emitting diodes with blue and orange emitting layers

Science.gov (United States)

Tsuboi, Taiju; Kishimoto, Tadashi; Wako, Kazuhiro; Matsuda, Kuniharu; Iguchi, Hirofumi

2012-10-01

White fluorescent OLED devices with a 10 nm thick blue-emitting layer and a 31 nm thick orange-emitting layer have been fabricated, where the blue-emitting layer is stacked on a hole transport layer. An interlayer was inserted between the two emitting layers. The thickness of the interlayer was changed among 0.3, 0.4, and 1.0 nm. White emission with CIE coordinates close to (0.33, 0.33) was observed from all the OLEDs. OLED with 0.3 nm thick interlayer gives the highest maximum luminous efficiency (11 cd/A), power efficiency (9 lm/W), and external quantum efficiency (5.02%). The external quantum efficiency becomes low with increasing the interlayer thickness from 0 nm to 1.0 nm. When the location of the blue- and orange-emitting layers is reversed, white emission was not obtained because of too weak blue emission. It is suggested that the electron-hole recombination zone decreases nearly exponentially with a distance from the hole transport layer.

Pentobarbital quantitation using EMIT serum barbiturate assay reagents: application to monitoring of high-dose pentobarbital therapy.

Science.gov (United States)

Pape, B E; Cary, P L; Clay, L C; Godolphin, W

1983-01-01

Pentobarbital serum concentrations associated with a high-dose therapeutic regimen were determined using EMIT immunoassay reagents. Replicate analyses of serum controls resulted in a within-assay coefficient of variation of 5.0% and a between-assay coefficient of variation of 10%. Regression analysis of 44 serum samples analyzed by this technique (y) and a reference procedure (x) were y = 0.98x + 3.6 (r = 0.98; x = ultraviolet spectroscopy) and y = 1.04x + 2.4 (r = 0.96; x = high-performance liquid chromatography). Clinical evaluation of the results indicates the immunoassay is sufficiently sensitive and selective for pentobarbital to allow accurate quantitation within the therapeutic range associated with high-dose therapy.

The wheel-rail contact friction influence on high speed vehicle model stability

Directory of Open Access Journals (Sweden)

Mirosław DUSZA

2015-09-01

Full Text Available Right estimating of the coefficient of friction between the wheel and rail is essential in modelling rail vehicle dynamics. Constant value of coefficient of friction is the typical assumption in theoretical studies. But it is obvious that in real circumstances a few factors may have significant influence on the rails surface condition and this way on the coefficient of friction value. For example the weather condition, the railway location etc. Influence of the coefficient of friction changes on high speed rail vehicle model dynamics is presented in this paper. Four axle rail vehicle model were built. The FASTSIM code is employed for calculation of the tangential contact forces between wheel and rail. One coefficient of friction value is adopted in the particular simulation process. To check the vehicle model properties under the influence of wheel-rail coefficient of friction changes, twenty four series of simulations were performed. For three curved tracks of radii R = 3000m, 6000m and  (straight track, the coefficient of friction was changed from 0.1 to 0.8. The results are presented in form of bifurcation diagrams.

The vertical-cavity surface-emitting laser incorporating a high contrast grating mirror as a sensing device

Science.gov (United States)

Marciniak, Magdalena; Gebski, Marcin; Piskorski, Łukasz; Dems, Maciej; Wasiak, M.; Panajotov, Krassimir; Lott, James A.; Czyszanowski, Tomasz

2018-02-01

We propose a novel optical sensing system based on one device that both emits and detects light consisting of a verticalcavity surface-emitting laser (VCSEL) incorporating an high contrast grating (HCG) as a top mirror. Since HCGs can be very sensitive to the optical properties of surrounding media, they can be used to detect gases and liquid. The presence of a gas or a liquid around an HCG mirror causes changes of the power reflectance of the mirror, which corresponds to changes of the VCSEL's cavity quality factor and current-voltage characteristic. By observation of the current-voltage characteristic we can collect information about the medium around the HCG. In this paper we investigate how the properties of the HCG mirror depend on the refractive index of the HCG surroundings. We present results of a computer simulation performed with a three-dimensional fully vectorial model. We consider silicon HCGs on silica and designed for a 1300 nm VCSEL emission wavelength. We demonstrate that our approach can be applied to other wavelengths and material systems.

A high-energy, low-threshold tunable intracavity terahertz-wave parametric oscillator with surface-emitted configuration

International Nuclear Information System (INIS)

Wang, Y Y; Xu, D G; Jiang, H; Zhong, K; Yao, J Q

2013-01-01

A high-energy, low-threshold THz-wave output has been experimentally demonstrated with an intracavity terahertz-wave parametric oscillator based on a surface-emitted configuration, which was pumped by a diode-side-pumped Q-switched Nd:YAG laser. Different beam sizes and repetition rates of the pump light have been investigated for high-energy and high-efficiency THz-wave generation. The maximum THz-wave output energy of 283 nJ/pulse was obtained at 1.54 THz under an intracavity 1064 nm pump energy of 59 mJ. The conversion efficiency was 4.8 × 10 −6 , corresponding to a photon conversion efficiency of 0.088%. The pump threshold was 12.9 mJ/pulse. A continuously tunable range from 0.75 to 2.75 THz was realized. (paper)

Fuel Options for Vehicles in Korea and Role of Nuclear Energy

International Nuclear Information System (INIS)

Jeong, Yong Hoon; Chang, Soon Heung

2005-01-01

Nowadays, almost all vehicles in Korea are powered by gasoline or diesel and they are emitting about 25% of nationwide total carbon dioxide emission. With jetting up price of oil and concerns about global warming by use of fossil fuel, transition to the hydrogen economy gains more and more interest. As alternatives to the current fossil powered vehicles, hybrid, hydrogen, electricity powered vehicles are considered. In short term we will reduce dependence upon fossil fuel by using hybrid cars. However, in the long term, we have to escape from the dependence on fossil fuel. In this context, nuclear-driven hydrogen or electricity powered cars are the alternatives. In this study, we estimated the operation cost of cars powered by hydrogen and electricity from nuclear power and studied about the major blocks on the way to independence from fossil fuels. In the analysis, we put the capital cost of car aside

Effects of vehicle power on passenger vehicle speeds.

Science.gov (United States)

McCartt, Anne T; Hu, Wen

2017-07-04

During the past 2 decades, there have been large increases in mean horsepower and the mean horsepower-to-vehicle weight ratio for all types of new passenger vehicles in the United States. This study examined the relationship between travel speeds and vehicle power, defined as horsepower per 100 pounds of vehicle weight. Speed cameras measured travel speeds and photographed license plates and drivers of passenger vehicles traveling on roadways in Northern Virginia during daytime off-peak hours in spring 2013. The driver licensing agencies in the District of Columbia, Maryland, and Virginia provided vehicle information numbers (VINs) by matching license plate numbers with vehicle registration records and provided the age, gender, and ZIP code of the registered owner(s). VINs were decoded to obtain the curb weight and horsepower of vehicles. The study focused on 26,659 observed vehicles for which information on horsepower was available and the observed age and gender of drivers matched vehicle registration records. Log-linear regression estimated the effects of vehicle power on mean travel speeds, and logistic regression estimated the effects of vehicle power on the likelihood of a vehicle traveling over the speed limit and more than 10 mph over the limit. After controlling for driver characteristics, speed limit, vehicle type, and traffic volume, a 1-unit increase in vehicle power was associated with a 0.7% increase in mean speed, a 2.7% increase in the likelihood of a vehicle exceeding the speed limit by any amount, and an 11.6% increase in the likelihood of a vehicle exceeding the limit by 10 mph. All of these increases were highly significant. Speeding persists as a major factor in crashes in the United States. There are indications that travel speeds have increased in recent years. The current findings suggest the trend toward substantially more powerful vehicles may be contributing to higher speeds. Given the strong association between travel speed and crash

Li4SrCa(SiO4)2:Ce3+, a highly efficient near-UV and blue emitting orthosilicate phosphor

International Nuclear Information System (INIS)

Zhang, Jilin; Zhang, Weilu; Qiu, Zhongxian; Zhou, Wenli; Yu, Liping; Li, Zhiqiang; Lian, Shixun

2015-01-01

High quantum efficiency is a vital parameter of phosphors for practical application. An efficient near-UV and blue emitting phosphor Li 4 SrCa(SiO 4 ) 2 :Ce 3+ was synthesized by a traditional solid-state reaction, and luminescent properties were studied in detail. The Ce 3+ -activated phosphor can emit both a near-UV light centred at 345 nm and a blue light peaking at 420 nm when Ce 3+ occupies the Sr and Ca site, respectively. The internal quantum efficiency (IQE) of Li 4 SrCa(SiO 4 ) 2 :0.03Ce 3+ is as high as 97% under the excitation at 288 nm, while the external quantum efficiency (EQE) is 66%. The IQE and EQE values of Li 4 SrCa(SiO 4 ) 2 :0.03Ce 3+ under the excitation at 360 nm are 82% and 31%, respectively. - Highlights: • Phosphor Li 4 SrCa(SiO 4 ) 2 :Ce 3+ emits a near-UV (345 nm) and a blue light (420 nm). • Emission band at 345 nm originates from Ce 3+ on Sr site. • Emission band at 420 nm belongs to Ce 3+ on Ca site. • Internal quantum efficiency is 97% for Li 4 SrCa(SiO 4 ) 2 :0.03Ce 3+ excited at 288 nm

Oxycarbonitride phosphors and light emitting devices using the same

Science.gov (United States)

Li, Yuanqiang; Romanelli, Michael Dennis; Tian, Yongchi

2013-10-08

Disclosed herein is a novel family of oxycarbidonitride phosphor compositions and light emitting devices incorporating the same. Within the sextant system of M--Al--Si--O--N--C--Ln and quintuplet system of M--Si--O--N--C--Ln (M=alkaline earth element, Ln=rare earth element), the phosphors are composed of either one single crystalline phase or two crystalline phases with high chemical and thermal stability. In certain embodiments, the disclosed phosphor of silicon oxycarbidonitrides emits green light at wavelength between 530-550 nm. In further embodiments, the disclosed phosphor compositions emit blue-green to yellow light in a wavelength range of 450-650 nm under near-UV and blue light excitation.

Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

OpenAIRE

Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

2008-01-01

In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible e...

High performance tunnel injection InGaN/GaN quantum Dot light emitting diodes emitting in the green (λ=495nm)

KAUST Repository

Zhang, Meng; Banerjee, Animesh; Bhattacharya, Pallab

2011-01-01

peak at 495 nm at 300 K. The characteristics of tunnel injection InGaN/GaN quantum dot light emitting diodes are presented. The current density at maximum efficiency is 90.2 A/cm 2, which is superior to equivalent multiquantum well devices. © 2010

Light Converting Inorganic Phosphors for White Light-Emitting Diodes

Directory of Open Access Journals (Sweden)

Chiao-Wen Yeh

2010-03-01

Full Text Available 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 near-ultraviolet (nUV LEDs and photoluminescence phosphors. These solid-state LED lamps, rather than organic light emitting diode (OLED or polymer light-emitting diode (PLED, 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. To meet with the further requirement of high color rendering index, warm light with low color temperature, high thermal stability and higher energy efficiency for WLEDs, new phosphors that can absorb excitation energy from blue or nUV LEDs and generate visible emissions efficiently are desired. The criteria of choosing the best phosphors, for blue (450-480 nm and nUV (380-400 nm LEDs, strongly depends on the absorption and emission of the phosphors. Moreover, the balance of light between the emission from blue-nUV LEDs and the emissions from phosphors (such as yellow from Y3Al5O12:Ce3+ is important to obtain white light with proper color rendering index and color temperature. Here, we will review the status of phosphors for LEDs and prospect the future development.

Light Converting Inorganic Phosphors for White Light-Emitting Diodes

Science.gov (United States)

Chen, Lei; Lin, Chun-Che; Yeh, Chiao-Wen; Liu, Ru-Shi

2010-01-01

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 near-ultraviolet (nUV) LEDs) and photoluminescence phosphors. These solid-state LED lamps, rather than organic light emitting diode (OLED) or polymer light-emitting diode (PLED), 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. To meet with the further requirement of high color rendering index, warm light with low color temperature, high thermal stability and higher energy efficiency for WLEDs, new phosphors that can absorb excitation energy from blue or nUV LEDs and generate visible emissions efficiently are desired. The criteria of choosing the best phosphors, for blue (450−480 nm) and nUV (380−400 nm) LEDs, strongly depends on the absorption and emission of the phosphors. Moreover, the balance of light between the emission from blue-nUV LEDs and the emissions from phosphors (such as yellow from Y3Al5O12:Ce3+) is important to obtain white light with proper color rendering index and color temperature. Here, we will review the status of phosphors for LEDs and prospect the future development.

Optical modelling of photoluminescence emitted by thin doped films

International Nuclear Information System (INIS)

Pigeat, P.; Easwarakhanthan, T.; Briancon, J.L.; Rinnert, H.

2011-01-01

Photoluminescence (PL) spectra emitted by doped films are deformed owing to film thickness-dependent wave interference. This hampers knowing well their PL generating mechanisms as well as designing photonic devices with suitable geometries that improve their PL efficiency. We develop in this paper an energy model for PL emitted by doped films considering the interaction between the wavelength-differing incident standing and emitted waves, their energy transfer in-between, and the interferences undergone by both. The film optical constants are estimated fitting the model to the measured PL. This simple model has thus allowed us to interpret the evolution of PL emitted by Er-doped AlN films prepared on Si substrates by reactive magnetron sputtering. The shapes, the amplitudes, and the illusive sub-spectral features of the PL spectra depend essentially on the film thickness. The model further predicts high sensitivity for PL emitted by non-homogenously doped stacked-films to incident light wavelengths and film-thickness variations. This property has potential applications in tracking wavelength variations and in measuring physical quantities producing thickness variations. This model may be used to optimise PL efficiency of photonic devices through different film geometries and optical properties.

Blue and white phosphorescent organic light emitting diode performance improvement by confining electrons and holes inside double emitting layers

Energy Technology Data Exchange (ETDEWEB)

Tsai, Yu-Sheng; Hong, Lin-Ann; Juang, Fuh-Shyang; Chen, Cheng-Yin

2014-09-15

In this research, complex emitting layers (EML) were fabricated using TCTA doping hole-transport material in the front half of a bipolar 26DCzPPy as well as PPT doping electron-transport material in the back half of 26DCzPPy. Blue dopant FIrpic was also mixed inside the complex emitting layer to produce a highly efficient blue phosphorescent organic light emitting diode (OLED). The hole and electron injection and carrier recombination rate were effectively increased. The fabricated complex emitting layers exhibited current efficiency of 42 cd/A and power efficiency of 30 lm/W when the luminance was 1000 cd/m{sup 2}, driving voltage was 4.4 V, and current density was 2.4 mA/cm{sup 2}. A white OLED component was then manufactured by doping red dopant [Os(bpftz){sub 2}(PPh{sub 2}Me){sub 2}] (Os) in proper locations. When the Os dopant was doped in between the complex emitting layers, excitons were effectively confined within, increasing the recombination rate and therefore reducing the color shift. The resulting Commission Internationale de L’Eclairage (CIE) coordinates shifted from 4 to 10 V is (Δx=−0.04, Δy=+0.01). The component had a current efficiency of 35.7 cd/A, a power efficiency of 24 lm/W, driving voltage of 4.6 V and a CIE{sub x,y} of (0.31,0.35) at a luminance of 1000 cd/m{sup 2}, with a maximum luminance of 15,600 cd/m{sup 2} at 10 V. Attaching an outcoupling enhancement film was applied to increase the luminance efficiency to 30 lm/W. - Highlights: • Used the complex double emitting layers. • Respectively doped hole and electron transport material in the bipolar host. • Electrons and holes are effectively confined within EMLs to produce excitons.

Blue and white phosphorescent organic light emitting diode performance improvement by confining electrons and holes inside double emitting layers

International Nuclear Information System (INIS)

Tsai, Yu-Sheng; Hong, Lin-Ann; Juang, Fuh-Shyang; Chen, Cheng-Yin

2014-01-01

In this research, complex emitting layers (EML) were fabricated using TCTA doping hole-transport material in the front half of a bipolar 26DCzPPy as well as PPT doping electron-transport material in the back half of 26DCzPPy. Blue dopant FIrpic was also mixed inside the complex emitting layer to produce a highly efficient blue phosphorescent organic light emitting diode (OLED). The hole and electron injection and carrier recombination rate were effectively increased. The fabricated complex emitting layers exhibited current efficiency of 42 cd/A and power efficiency of 30 lm/W when the luminance was 1000 cd/m 2 , driving voltage was 4.4 V, and current density was 2.4 mA/cm 2 . A white OLED component was then manufactured by doping red dopant [Os(bpftz) 2 (PPh 2 Me) 2 ] (Os) in proper locations. When the Os dopant was doped in between the complex emitting layers, excitons were effectively confined within, increasing the recombination rate and therefore reducing the color shift. The resulting Commission Internationale de L’Eclairage (CIE) coordinates shifted from 4 to 10 V is (Δx=−0.04, Δy=+0.01). The component had a current efficiency of 35.7 cd/A, a power efficiency of 24 lm/W, driving voltage of 4.6 V and a CIE x,y of (0.31,0.35) at a luminance of 1000 cd/m 2 , with a maximum luminance of 15,600 cd/m 2 at 10 V. Attaching an outcoupling enhancement film was applied to increase the luminance efficiency to 30 lm/W. - Highlights: • Used the complex double emitting layers. • Respectively doped hole and electron transport material in the bipolar host. • Electrons and holes are effectively confined within EMLs to produce excitons

"Can Vehicle-to-Grid Revenue Help Electric Vehicles on the Market?"

OpenAIRE

George R. Parsons; Michael K. Hidrue; Willett Kempton; Meryl P. Gardner

2011-01-01

Vehicle-to-grid (V2G) electric vehicles can return power stored in their batteries back to the power grid and be programmed to do so at times when power prices are high. Since providing this service can lead to payments to owners of vehicles, it effectively reduces the cost of electric vehicles. Using data from a national stated preference survey (n = 3029), this paper presents the first study of the potential consumer demand for V2G electric vehicles. In our choice experiment, 3029 responden...

The design and implementation of vehicle scrapping programs

International Nuclear Information System (INIS)

Sahu, R.; Baxter, R.A.

1993-01-01

A number of metropolitan air basins in the US are currently faced with increased difficulty in attaining national and regional clean air standards. Significant controls on stationary sources over the years have allowed mobile sources to become the primary source of air emission in many areas. Programs allowing the use of mobile source offsets for stationary source emission by removal of older, higher emitting vehicles through scrappage programs are, therefore, conceptually attractive and are starting to be implemented. However, achieving success in such scrappage programs is a challenge given the associated technical, economic and social issues. This paper presents a discussion of the important issues that must be considered if vehicle scrappage programs are to be successful, including recent guidance and views of the EPA and state governments on the credits associated with the programs. Although the main focus of such programs is the reduction of criteria pollutants (CO, ROG, NO x , and PM 10 ), the impact on air toxics also has to be considered. The paper will then focus on the technical design of vehicle scrappage programs such that the resulting credits are real, verifiable, enforceable, and cost-effective. Information available under existing vehicle I/M programs along with economic, vehicle maintenance, and geographic data will be used with statistical techniques in order to meet predetermined program goals regarding emissions reduction and cost-effectiveness. A later case-study paper will discuss the actual implementation of such as program in an ozone non-attainment area

Removal of main exhaust gases of vehicles by a double dielectric barrier discharge

International Nuclear Information System (INIS)

Pacheco, M; Valdivia, R; Pacheco, J; Rivera, C; Alva, E; Santana, A; Huertas, J; Lefort, B; Estrada, N

2012-01-01

Because the health effects and their contribution to climate change, the emissions of toxic gases are becoming more controlled. In order to improve the diminution of toxic gases to the atmosphere, several techniques have been developed; here it will be focus only to automotive emissions. This work deals about the treatment of toxic gases emitted from vehicles by a non-thermal plasma. Several tests were done in a 4-cylinder 2002/Z16SE motor to characterize the vehicle emissions. With these results gas mixture simulating the exhaust gases vehicles, was used in experiments at different conditions employing a double dielectric barrier reactor for their treatment. The removal efficiencies superior to 90% show the competence of the non-thermal plasma reactor to treat these gases. Experimental results are explained with the aid of a simple chemical model that suggests a possible mechanism of degradation of toxic gases. The plasma reactor employed could works at 12V supplied without difficulty by a vehicle battery.

Electrically heated catalysts for cold-start emission control on gasoline- and methanol-fueled vehicles

International Nuclear Information System (INIS)

Heimrich, M.J.; Albu, S.; Ahuja, M.

1992-01-01

Cold-start emissions from current technology vehicles equipped with catalytic converters can account for over 80 percent of the emissions produced during the Federal Test Procedure (FTP). Excessive pollutants can be emitted for a period of one to two minutes following cold engine starting, partially because the catalyst has not reached an efficient operating temperature. Electrically heated catalysts, which are heated prior to engine starting, have been identified as a potential strategy for controlling cold-start emissions. This paper summarizes the emission results of three gasoline-fueled and three methanol-fueled vehicles equipped with electrically heated catalyst systems. Results from these vehicles demonstrate that heated catalyst technology can provide FTP emission levels of nonmethane organic gases (NMOG), carbon monoxide (CO), and oxides of nitrogen (NO x ) that show promise of meeting the Ultra-Low Emission Vehicle (ULEV) standards established by the California Air Resources Board

A numerical investigation on the efficiency of range extending systems using Advanced Vehicle Simulator

Science.gov (United States)

Varnhagen, Scott; Same, Adam; Remillard, Jesse; Park, Jae Wan

2011-03-01

Series plug-in hybrid electric vehicles of varying engine configuration and battery capacity are modeled using Advanced Vehicle Simulator (ADVISOR). The performance of these vehicles is analyzed on the bases of energy consumption and greenhouse gas emissions on the tank-to-wheel and well-to-wheel paths. Both city and highway driving conditions are considered during the simulation. When simulated on the well-to-wheel path, it is shown that the range extender with a Wankel rotary engine consumes less energy and emits fewer greenhouse gases compared to the other systems with reciprocating engines during many driving cycles. The rotary engine has a higher power-to-weight ratio and lower noise, vibration and harshness compared to conventional reciprocating engines, although performs less efficiently. The benefits of a Wankel engine make it an attractive option for use as a range extender in a plug-in hybrid electric vehicle.

White top emitting OLED with angle independent emission characteristic

Energy Technology Data Exchange (ETDEWEB)

Thomschke, Michael; Freitag, Patricia; Schwartz, Gregor; Nitsche, Robert; Walzer, Karsten; Leo, Karl [Technische Universitaet Dresden, Institut fuer Angewandte Photophysik, Georg-Baehr-Strasse 1, 01062 Dresden (Germany)

2008-07-01

The general device structure of a top emitting organic light emitting diode (OLED) consists of several organic layers sandwiched in between two metal contacts, with the top one being semitransparent for light outcoupling reasons. Due to the high reflectivity of the electrodes, strong microcavity effects occur which lead to a preferred emission of light of a certain wavelength with main outcoupling in forward direction. This creates rather narrow emission bands, accompanied by strong spectral shifts upon viewing angle variation. By using an organic capping layer on top of the semitransparent metal contact, this unwanted effect can be reduced. This is important especially for white light emission for the use of OLEDs in future lighting applications. Our optical simulations show that the strong angular dependence of the emission color almost vanishes. To verify the simulations we study white top emitting OLEDs based on an approach which are adapted to the top emitting case.

Blue-light emitting triazolopyridinium and triazoloquinolinium salts

KAUST Repository

Carboni, Valentina; Su, Xin; Qian, Hai; Aprahamian, Ivan; Credi, Alberto

2017-01-01

Compounds that emit blue light are of interest for applications that include optoelectronic devices and chemo/biosensing and imaging. The design and synthesis of small organic molecules that can act as high-efficiency deep-blue-light emitters

The dynamic behaviour of rail vehicles operating at high speeds for manriding in British coal mines

Energy Technology Data Exchange (ETDEWEB)

Manen, P. van

1984-01-01

The behaviour of trains used at high speeds for transporting men along mine railways is examined using a number of mathematical models. These models predict the responses of different rail vehicles to typical irregularities in the track, and are used to examine the guidance, the ride, and the likelihood of derailment of the main classes of manriding trains used in British coal mines. The outcome of the modelling compares favourably with the results of tests carried out on actual vehicles. The investigation has shown that the safe speed at which trains may operate is ultimately restricted by the condition of the track, but changes in the design of the vehicles can lead to an improved performance. The use of conventional wheelsets, for example, can reduce flange wear significantly and so allow higher speeds to be reached. Guidelines for the design of vehicles intended for high speed use are included in this thesis. (36 refs.)

Efficient and bright organic light-emitting diodes on single-layer graphene electrodes

Science.gov (United States)

Li, Ning; Oida, Satoshi; Tulevski, George S.; Han, Shu-Jen; Hannon, James B.; Sadana, Devendra K.; Chen, Tze-Chiang

2013-08-01

Organic light-emitting diodes are emerging as leading technologies for both high quality display and lighting. However, the transparent conductive electrode used in the current organic light-emitting diode technologies increases the overall cost and has limited bendability for future flexible applications. Here we use single-layer graphene as an alternative flexible transparent conductor, yielding white organic light-emitting diodes with brightness and efficiency sufficient for general lighting. The performance improvement is attributed to the device structure, which allows direct hole injection from the single-layer graphene anode into the light-emitting layers, reducing carrier trapping induced efficiency roll-off. By employing a light out-coupling structure, phosphorescent green organic light-emitting diodes exhibit external quantum efficiency >60%, while phosphorescent white organic light-emitting diodes exhibit external quantum efficiency >45% at 10,000 cd m-2 with colour rendering index of 85. The power efficiency of white organic light-emitting diodes reaches 80 lm W-1 at 3,000 cd m-2, comparable to the most efficient lighting technologies.

High power ultraviolet light emitting diodes based on GaN/AlGaN quantum wells produced by molecular beam epitaxy

International Nuclear Information System (INIS)

Cabalu, J. S.; Bhattacharyya, A.; Thomidis, C.; Friel, I.; Moustakas, T. D.; Collins, C. J.; Komninou, Ph.

2006-01-01

In this paper, we report on the growth by molecular beam epitaxy and fabrication of high power nitride-based ultraviolet light emitting diodes emitting in the spectral range between 340 and 350 nm. The devices were grown on (0001) sapphire substrates via plasma-assisted molecular beam epitaxy. The growth of the light emitting diode (LED) structures was preceded by detailed materials studies of the bottom n-AlGaN contact layer, as well as the GaN/AlGaN multiple quantum well (MQW) active region. Specifically, kinetic conditions were identified for the growth of the thick n-AlGaN films to be both smooth and to have fewer defects at the surface. Transmission-electron microscopy studies on identical GaN/AlGaN MQWs showed good quality and well-defined interfaces between wells and barriers. Large area mesa devices (800x800 μm 2 ) were fabricated and were designed for backside light extraction. The LEDs were flip-chip bonded onto a Si submount for better heat sinking. For devices emitting at 340 nm, the measured differential on-series resistance is 3 Ω with electroluminescence spectrum full width at half maximum of 18 nm. The output power under dc bias saturates at 0.5 mW, while under pulsed operation it saturates at approximately 700 mA to a value of 3 mW, suggesting that thermal heating limits the efficiency of these devices. The output power of the investigated devices was found to be equivalent with those produced by the metal-organic chemical vapor deposition and hydride vapor-phase epitaxy methods. The devices emitting at 350 nm were investigated under dc operation and the output power saturates at 4.5 mW under 200 mA drive current

Development of a Highly Efficient Hybrid White Organic-Light-Emitting Diode with a Single Emission Layer by Solution Processing.

Science.gov (United States)

Wu, Jun-Yi; Chen, Show-An

2018-02-07

We use a mixed host, 2,6-bis[3-(carbazol-9-yl)phenyl]pyridine blended with 20 wt % tris(4-carbazoyl-9-ylphenyl)amine, to lower the hole-injection barrier, along with the bipolar and high-photoluminescence-quantum-yield (Φ p = 84%), blue thermally activated delay fluorescence (TADF) material of 9,9-dimethyl-9,10-dihydroacridine-2,4,6-triphenyl-1,3,5-triazine (DMAC-TRZ) as a blue dopant to compose the emission layer for the fabrication of a TADF blue organic-light-emitting diode (BOLED). The device is highly efficient with the following performance parameters: maximum brightness (B max ) = 57586 cd/m 2 , maximum current efficiency (CE max ) = 35.3 cd/A, maximum power efficiency (PE max ) = 21.4 lm/W, maximum external quantum efficiency (EQE max ) = 14.1%, and CIE coordinates (0.18, 0.42). This device has the best performance recorded among the reported solution-processed TADF BOLEDs and has a low efficiency roll-off: at brightness values of 1000 and 5000 cd/m 2 , its CEs are close, being 35.1 and 30.1 cd/A, respectively. Upon further doping of the red phosphor Ir(dpm)PQ 2 (emission peak λ max = 595 nm) into the blue emission layer, we obtained a TADF-phosphor hybrid white organic-light-emitting diode (T-P hybrid WOLED) with high performance: B max = 43594 cd/m 2 , CE max = 28.8 cd/A, PE max = 18.1 lm/W, and CIE coordinates (0.38, 0.44). This B max = 43594 cd/m 2 is better than that of the vacuum-deposited WOLED with a blue TADF emitter, 10000 cd/m 2 . This is also the first report on a T-P hybrid WOLED with a solution-processed emitting layer.

Comprehensive analysis of the carbon impacts of vehicle intelligent speed control

Science.gov (United States)

Carslaw, David C.; Goodman, Paul S.; Lai, Frank C. H.; Carsten, Oliver M. J.

2010-07-01

In recent years sophisticated technologies have been developed to control vehicle speed based on the type of road the vehicle is driven on using Global Positioning Systems and in-car technology that can alter the speed of the vehicle. While reducing the speed of road vehicles is primarily of interest from a safety perspective, vehicle speed is also an important determinant of vehicle emissions and thus these technologies can be expected to have impacts on a range of exhaust emissions. This work analyses the results from a very large, comprehensive field trial that used 20 instrumented vehicles with and without speed control driven almost 500,000 km measuring vehicle speed at 10 Hz. We develop individual vehicle modal emissions models for CO 2 for 30 Euro III and Euro IV cars at a 1-Hz time resolution. Generalized Additive Models were used to describe how emissions from individual vehicles vary depending on their driving conditions, taking account of variable interactions and time-lag effects. We quantify the impact that vehicle speed control has on-vehicle emissions of CO 2 by road type, fuel type and driver behaviour. Savings in CO 2 of ≈6% were found on average for motorway-type roads when mandatory speed control was used compared with base case conditions. For most other types of road, speed control has very little effect on emissions of CO 2 and in some cases can result in increased emissions for low-speed limit urban roads. We also find that there is on average a 20% difference in CO 2 emission between the lowest and highest emitting driver, which highlights the importance of driver behaviour in general as a means of reducing emissions of CO 2.

Battery sizing for serial plug-in hybrid electric vehicles: A model-based economic analysis for Germany

International Nuclear Information System (INIS)

Ernst, Christian-Simon; Hackbarth, Andre; Madlener, Reinhard; Lunz, Benedikt; Uwe Sauer, Dirk; Eckstein, Lutz

2011-01-01

The battery size of a Plug-in Hybrid Electric Vehicle (PHEV) is decisive for the electrical range of the vehicle and crucial for the cost-effectiveness of this particular vehicle concept. Based on the energy consumption of a conventional reference car and a PHEV, we introduce a comprehensive total cost of ownership model for the average car user in Germany for both vehicle types. The model takes into account the purchase price, fixed annual costs and variable operating costs. The amortization time of a PHEV also depends on the recharging strategy (once a day, once a night, after each trip), the battery size, and the battery costs. We find that PHEVs with a 4 kWh battery and at current lithium-ion battery prices reach the break-even point after about 6 years (5 years when using the lower night-time electricity tariffs). With higher battery capacities the amortization time becomes significantly longer. Even for the small battery size and assuming the EU-15 electricity mix, a PHEV is found to emit only around 60% of the CO 2 emissions of a comparable conventional car. Thus, with the PHEV concept a cost-effective introduction of electric mobility and reduction of greenhouse gas emissions per vehicle can be reached. - Highlights: → Total cost of ownership of a PHEV and a conventional car are compared for the average German car user.→ PHEVs with a 4 kWh battery reach the break-even after 5-6 years at current Li-Ion battery prices.→ Even with a small battery, PHEVs emit about 40% less CO 2 emissions than the average conventional car.

A Soft-Switching Inverter for High-Temperature Advanced Hybrid Electric Vehicle Traction Motor Drives

Energy Technology Data Exchange (ETDEWEB)

Lai, Jason [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yu, Wensong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Sun, Pengwei [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Leslie, Scott [Powerex, Inc., Harrison, OH (United States); Prusia, Duane [Powerex, Inc., Harrison, OH (United States); Arnet, Beat [Azure Dynamics, Oak Park, MI (United States); Smith, Chris [Azure Dynamics, Oak Park, MI (United States); Cogan, Art [Azure Dynamics, Oak Park, MI (United States)

2012-03-31

The state-of-the-art hybrid electric vehicles (HEVs) require the inverter cooling system to have a separate loop to avoid power semiconductor junction over temperatures because the engine coolant temperature of 105°C does not allow for much temperature rise in silicon devices. The proposed work is to develop an advanced soft-switching inverter that will eliminate the device switching loss and cut down the power loss so that the inverter can operate at high-temperature conditions while operating at high switching frequencies with small current ripple in low inductance based permanent magnet motors. The proposed tasks also include high-temperature packaging and thermal modeling and simulation to ensure the packaged module can operate at the desired temperature. The developed module will be integrated with the motor and vehicle controller for dynamometer and in-vehicle testing to prove its superiority. This report will describe the detailed technical design of the soft-switching inverters and their test results. The experiments were conducted both in module level for the module conduction and switching characteristics and in inverter level for its efficiency under inductive and dynamometer load conditions. The performance will be compared with the DOE original specification.

Space vehicle chassis

Science.gov (United States)

Judd, Stephen; Dallmann, Nicholas; Seitz, Daniel; Martinez, John; Storms, Steven; Kestell, Gayle

2017-07-18

A modular space vehicle chassis may facilitate convenient access to internal components of the space vehicle. Each module may be removable from the others such that each module may be worked on individually. Multiple panels of at least one of the modules may swing open or otherwise be removable, exposing large portions of the internal components of the space vehicle. Such chassis architectures may reduce the time required for and difficulty of performing maintenance or modifications, may allow multiple space vehicles to take advantage of a common chassis design, and may further allow for highly customizable space vehicles.

Organic bistable light-emitting devices

Science.gov (United States)

Ma, Liping; Liu, Jie; Pyo, Seungmoon; Yang, Yang

2002-01-01

An organic bistable device, with a unique trilayer structure consisting of organic/metal/organic sandwiched between two outmost metal electrodes, has been invented. [Y. Yang, L. P. Ma, and J. Liu, U.S. Patent Pending, U.S. 01/17206 (2001)]. When the device is biased with voltages beyond a critical value (for example 3 V), the device suddenly switches from a high-impedance state to a low-impedance state, with a difference in injection current of more than 6 orders of magnitude. When the device is switched to the low-impedance state, it remains in that state even when the power is off. (This is called "nonvolatile" phenomenon in memory devices.) The high-impedance state can be recovered by applying a reverse bias; therefore, this bistable device is ideal for memory applications. In order to increase the data read-out rate of this type of memory device, a regular polymer light-emitting diode has been integrated with the organic bistable device, such that it can be read out optically. These features make the organic bistable light-emitting device a promising candidate for several applications, such as digital memories, opto-electronic books, and recordable papers.

A two-pole Halbach permanent magnet guideway for high temperature superconducting Maglev vehicle

International Nuclear Information System (INIS)

Jing, H.; Wang, J.; Wang, S.; Wang, L.; Liu, L.; Zheng, J.; Deng, Z.; Ma, G.; Zhang, Y.; Li, J.

2007-01-01

In order to improve the levitation performance of the high temperature superconducting (HTS) magnetic levitation (Maglev) vehicle, a two-pole Halbach array's permanent magnet guideway (PMG) is proposed, which is called as Halbach PMG. The finite element method (FEM) calculations indicate that Halbach PMG has a wider high-field region than the present PMG of equal PM's transverse section. The levitation force of bulk HTSCs with the present PMG and Halbach PMG are measured. The results show that at different levitation gaps, the force ratios based on the Halbach PMG are about 2.3 times larger than that on the present PMG, which greatly increases the load capability of the system. Therefore, both the numerical analysis and experimental results have confirmed that the Halbach PMG will further enhance the performance of the vehicle and it is possible to decrease the total numbers of onboard HTSCs, reducing overall costs. So based on the Halbach PMG, we further study the width ratios between HTSCs and PMG for making the better use of the onboard HTSCs. Some preliminary results are given. These results are important for further HTS Maglev vehicle system designs using Halbach PMG

Radiation emitting devices act

International Nuclear Information System (INIS)

1970-01-01

This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

Technology Roadmaps - Electric and plug-in hybrid electric vehicles (EV/PHEV)

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-06-15

The mass deployment of electric and plug-in hybrid electric vehicles (EVs and PHEVs) that rely on low greenhouse gas (GHG) emission electricity generation has great potential to significantly reduce the consumption of petroleum and other high CO2-emitting transportation fuels. The vision of the Electric and Plug-in Hybrid (EV/PHEV) Vehicles Roadmap is to achieve by 2050 the widespread adoption and use of EVs and PHEVs, which together represent more than 50% of annual LDV (light duty vehicle) sales worldwide. In addition to establishing a vision, this roadmap sets strategic goals to achieve it, and identifies the steps that need to be taken to accomplish these goals. This roadmap also outlines the roles and collaboration opportunities for different stakeholders and shows how government policy can support the overall achievement of the vision. The strategic goals for attaining the widespread adoption and use of EVs and PHEVs worldwide by 2050 cover the development of the EV/PHEV market worldwide through 2030 and involve targets that align with global targets to stabilise GHG concentrations. These technology-specific goals include the following: Set targets for electric-drive vehicle sales; Develop coordinated strategies to support the market introduction of electric-drive vehicles; Improve industry understanding of consumer needs and behaviours; Develop performance metrics for characterising vehicles; Foster energy storage RD and D initiatives to reduce costs and address resource-related issues; and, Develop and implement recharging infrastructure. The roadmap outlines additional recommendations that must be considered in order to successfully meet the technology milestones and strategic goals. These recommendations include the following: Use a comprehensive mix of policies that provide a clear framework and balance stakeholder interests; Engage in international collaboration efforts; and, Address policy and industry needs at a national level. The IEA will work in an

Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

DEFF Research Database (Denmark)

Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

2008-01-01

In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive...... vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible economical incentives for the vehicle owners will be shown. By control of EDV charging through a price...... signal from the day ahead market the economical incentives for an EDV-owner will be small. If the EDV's can participate in the regulation of the grid through ancillary services the incentives will be increased to an attractive level....

An overview of experimental results and dispersion modelling of nanoparticles in the wake of moving vehicles.

Science.gov (United States)

Carpentieri, Matteo; Kumar, Prashant; Robins, Alan

2011-03-01

Understanding the transformation of nanoparticles emitted from vehicles is essential for developing appropriate methods for treating fine scale particle dynamics in dispersion models. This article provides an overview of significant research work relevant to modelling the dispersion of pollutants, especially nanoparticles, in the wake of vehicles. Literature on vehicle wakes and nanoparticle dispersion is reviewed, taking into account field measurements, wind tunnel experiments and mathematical approaches. Field measurements and modelling studies highlighted the very short time scales associated with nanoparticle transformations in the first stages after the emission. These transformations strongly interact with the flow and turbulence fields immediately behind the vehicle, hence the need of characterising in detail the mixing processes in the vehicle wake. Very few studies have analysed this interaction and more research is needed to build a basis for model development. A possible approach is proposed and areas of further investigation identified. Copyright © 2010 Elsevier Ltd. All rights reserved.

Lead-free/rare earth-free Green-light-emitting crystal based on organic-inorganic hybrid [(C10H16N)2][MnBr4] with high emissive quantum yields and large crystal size

Science.gov (United States)

Cai, Xing-Wei; Zhao, Yu-Yuan; Li, Hong; Huang, Cui-Ping; Zhou, Zhen

2018-06-01

With the flourishing development of emitting materials, tremendous technological progress has been accomplished. However, they still face great challenges in convenient economical environmental-friendly large-scale commercial production. Herein we designed this organic-inorganic hybrid lead-free compound, an emerging class of high-efficiency emitting materials, [(C10H16N)2][MnBr4] (1), which emits intense greenish photoluminescence with a high emissive quantum yields of 72.26%, was prepared through the convenient economical solution method. What's more, compared with rare earth fluorescent materials (especially green-emitting Tb), Mn material is rich in natural resources and low commercial cost, which would possess an increasingly predominant advantage in the preparation of luminescent materials. Additionally, the exceptional thermal stability as well as the low-cost/convenient preparation process makes crystal 1 with the large size of more than 1 cm to be an ideal technologically important green-emitting material and it would open up a new route towards the commercialization process of lead-free/rare earth-free hybrid emitting materials in display and sensing.

Trajectory Optimization and Conceptual Study of Small Test Vehicles for Hypersonic Engine Using High-Altitude Balloon

Science.gov (United States)

Tsuchiya, Takeshi; Takenaka, Youichi; Taguchi, Hideyuki; Sawai, Shujiro

Japan Aerospace Exploration Agency, JAXA announced a long-term vision recently. In the vision, JAXA aims to develop hypersonic aircrafts. A pre-cooled turbojet engine has great potential as one of newly developed hypersonic air-breathing engines. We also expect the engine to be installed in space transportation vehicles in future. For combustion test in real flight condition of the engines, JAXA has an experimental plan with a small test vehicle falling from a high-altitude balloon. This paper applies numerical analysis and optimization techniques to conceptual designs of the test vehicle in order to obtain the best configuration and trajectory that can achieve the flight test. The results show helpful knowledge when we design prototype vehicles.

Topical methyl-aminolevulinate photodynamic therapy using red light-emitting diode light for treatment of multiple actinic keratoses: A randomized, double-blind, placebo-controlled study.

Science.gov (United States)

Pariser, David; Loss, Robert; Jarratt, Michael; Abramovits, William; Spencer, James; Geronemus, Roy; Bailin, Philip; Bruce, Suzanne

2008-10-01

The use of light-emitting diode light offers practical advantages in photodynamic therapy (PDT) with topical methyl-aminolevulinate (MAL) for management of actinic keratoses (AK). We sought to evaluate the efficacy of MAL PDT using red light-emitting diode light. We conducted a multicenter, double-blind, randomized study. A total of 49 patients with 363 AK lesions had 16.8% MAL cream applied under occlusion for 3 hours, and 47 patients with 360 AK lesions had vehicle cream similarly applied. The lesions were then illuminated (630 nm, light dose 37 J/cm2) with repeated treatment 1 week later. Complete lesion and patient (all lesions showing complete response) response rates were evaluated 3 months after last treatment. MAL PDT was superior (PAK. MAL PDT using red light-emitting diode light is an appropriate treatment alternative for multiple AK lesions.

Diesel vehicles and sustainable mobility in the U.S

International Nuclear Information System (INIS)

Wallington, T.J.; Lambert, C.K.; Ruona, W.C.

2013-01-01

Concerns regarding global warming and energy security have increased the importance of decreasing emissions of CO 2 from vehicles. Diesel vehicles have higher fuel economy and lower CO 2 emissions than their gasoline counterparts. On a well-to-wheels per vehicle per km basis it has been estimated that diesel light-duty vehicles in 2015 will emit 14–27% less CO 2 than their gasoline counterparts. We estimate here that on a gCO 2 /kWh at peak torque, diesel medium-duty vehicles currently have an approximately 10% CO 2 advantage over their gasoline counterparts. At light and moderate loads the CO 2 advantage for medium-duty diesels with SCR after-treatment will be greater than 10% (reflecting pumping losses when gasoline engines are operated at low and moderate loads). Emission of NO x , HCs, and PM from diesel (and gasoline) vehicles has decreased substantially over the past decade and further reductions are anticipated in the future. In addition to the heavy-duty segment, which diesels currently dominate, modern diesel engines are likely to continue to play an important role in the medium-duty segment, and perhaps also in the light-duty segment in a transition to more sustainable mobility. - Highlights: ► This paper is part of a special issue on diesels organized by Lee Schipper. ► The paper provides an overview of advanced diesel technology from a U.S. perspective. ► Modern diesel engines are likely to contribute to a transition to more sustainable mobility

Normative legal regulating of vehicles with a high degree of automation of control: strategy and tactics for implementation in Russia

Science.gov (United States)

Kisulenko, B. V.; Bocharov, A. V.; Pugachev, V. V.

2018-02-01

The article discusses the risks specific to vehicles with a high level of automation of control, and conditions the limits on the operating conditions of such vehicles. The article determines existing legal barriers to the implementation of autonomous vehicles. The article contains an analysis of foreign practice of regulating in the European Union, Japan and the United States and information about the UNECE activities aimed at enabling operation of vehicles with a high degree of automation control. Basing on the results of the analysis, the authors made proposals for removal of legal barriers. The article also contains proposals for the development of specific requirements for autonomous vehicles associated with their specific features of design.

Supercavitating Vehicle Control

Science.gov (United States)

2008-10-10

401) 832-1511. DISTRIBUTION STATEMENT Approved for Public Release Distribution is unlimited 20081027289 Attorney Docket No. 96674 SUPERCAVITATING ...methods and more specifically to systems and methods for controlling a trajectory of a supercavitating vehicle. (2) Description of the Prior Art [0004...1 [0005) Some investigations into reducing the drag of high-speed, underwater vehicles have focused attention on supercavitating underwater vehicles

Research on Correlation between Vehicle Cycle and Engine Cycle in Heavy-duty commercial vehicle

Science.gov (United States)

lin, Chen; Zhong, Wang; Shuai, Liu

2017-12-01

In order to study the correlation between vehicle cycle and engine cycle in heavy commercial vehicles, the conversion model of vehicle cycle to engine cycle is constructed based on the vehicle power system theory and shift strategy, which considers the verification on diesel truck. The results show that the model has high rationality and reliability in engine operation. In the acceleration process of high speed, the difference of model gear selection leads to the actual deviation. Compared with the drum test, the engine speed distribution obtained by the model deviates to right, which fits to the lower grade. The grade selection has high influence on the model.

Pyridine substituted spirofluorene derivative as an electron transport material for high efficiency in blue organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Jeon, Soon Ok; Yook, Kyoung Soo; Lee, Jun Yeob, E-mail: leej17@dankook.ac.k

2010-11-01

The quantum efficiency of blue fluorescent organic light-emitting diodes was enhanced by 20% using a pyridine substituted spirofluorene-benzofluorene derivative as an electron transport material. 2',7'-Di(pyridin-3-yl)spiro[benzofluorene-7,9'-fluorene] (SPBP) was synthesized and it was used as the electron transport material to block the hole leakage from the emitting layer. The improvement of the quantum efficiency and power efficiency of the blue fluorescent organic light-emitting diodes using the SPBP was investigated.

Impacts of fleet types and charging modes for electric vehicles on emissions under different penetrations of wind power

Science.gov (United States)

Chen, Xinyu; Zhang, Hongcai; Xu, Zhiwei; Nielsen, Chris P.; McElroy, Michael B.; Lv, Jiajun

2018-05-01

Current Chinese policy promotes the development of both electricity-propelled vehicles and carbon-free sources of power. Concern has been expressed that electric vehicles on average may emit more CO2 and conventional pollutants in China. Here, we explore the environmental implications of investments in different types of electric vehicle (public buses, taxis and private light-duty vehicles) and different modes (fast or slow) for charging under a range of different wind penetration levels. To do this, we take Beijing in 2020 as a case study and employ hourly simulation of vehicle charging behaviour and power system operation. Assuming the slow-charging option, we find that investments in electric private light-duty vehicles can result in an effective reduction in the emission of CO2 at several levels of wind penetration. The fast-charging option, however, is counter-productive. Electrifying buses and taxis offers the most effective option to reduce emissions of NOx, a major precursor for air pollution.

A Closed-Loop Smart Control System Driving RGB Light Emitting Diodes

KAUST Repository

Al-Saggaf, Abeer

2015-05-01

The demand for control systems that are highly capable of driving solid-state optoelectronic devices has significantly increased with the advancement of their efficiency and elevation of their current consumption. This work presents a closed-loop control system that is based on a microcontroller embedded system capable of driving high power optoelectronic devices. In this version of the system, the device in the center of control is a high-power red, green, and blue light emitting diode package. The system features a graphical user interface, namely an Android mobile phone application, in which the user can easily use to vary the light color and intensity of the light-emitting device wirelessly via Bluetooth. Included in the system is a feedback mechanism constituted by a red, green, and blue color sensor through which the user can use to observe feedback color information about the emitted light. The system has many commercial application including in-door lighting and research application including plant agriculture research fields.

A Closed-Loop Smart Control System Driving RGB Light Emitting Diodes

KAUST Repository

Al-Saggaf, Abeer

2015-01-01

The demand for control systems that are highly capable of driving solid-state optoelectronic devices has significantly increased with the advancement of their efficiency and elevation of their current consumption. This work presents a closed-loop control system that is based on a microcontroller embedded system capable of driving high power optoelectronic devices. In this version of the system, the device in the center of control is a high-power red, green, and blue light emitting diode package. The system features a graphical user interface, namely an Android mobile phone application, in which the user can easily use to vary the light color and intensity of the light-emitting device wirelessly via Bluetooth. Included in the system is a feedback mechanism constituted by a red, green, and blue color sensor through which the user can use to observe feedback color information about the emitted light. The system has many commercial application including in-door lighting and research application including plant agriculture research fields.

Production of poinsettia (Euphorbia Pulcherrima) with light emitting diodes compared with the traditional high pressure sodium lamp

OpenAIRE

Thapa, Sabir

2017-01-01

Use of chemical are commonly used as tools for the commercial pot plant producers to grow strong, dwarfed, and compact plants. Although, these growth regulators have adverse effects on human health and the environment. So, this issue has motivated researchers to search for alternative methods for growth regulation. The aim of this study was to test light emitting diodes (LEDs) with different light qualities alone or in combination with high pressure sodium lamps (HPSs), to investigate their e...

Sliding Mode Pulsed Averaging IC Drivers for High Brightness Light Emitting Diodes

Energy Technology Data Exchange (ETDEWEB)

Dr. Anatoly Shteynberg, PhD

2006-08-17

This project developed new Light Emitting Diode (LED) driver ICs associated with specific (uniquely operated) switching power supplies that optimize performance for High Brightness LEDs (HB-LEDs). The drivers utilize a digital control core with a newly developed nonlinear, hysteretic/sliding mode controller with mixed-signal processing. The drivers are flexible enough to allow both traditional microprocessor interface as well as other options such as “on the fly” adjustment of color and brightness. Some other unique features of the newly developed drivers include • AC Power Factor Correction; • High power efficiency; • Substantially fewer external components should be required, leading to substantial reduction of Bill of Materials (BOM). Thus, the LED drivers developed in this research : optimize LED performance by increasing power efficiency and power factor. Perhaps more remarkably, the LED drivers provide this improved performance at substantially reduced costs compared to the present LED power electronic driver circuits. Since one of the barriers to market penetration for HB-LEDs (in particular “white” light LEDs) is cost/lumen, this research makes important contributions in helping the advancement of SSL consumer acceptance and usage.

Structural and fractal properties of particles emitted from spark ignition engines.

Science.gov (United States)

Chakrabarty, Rajan K; Moosmüller, Hans; Arnott, W Patrick; Garro, Mark A; Walker, John

2006-11-01

Size, morphology, and microstructure of particles emitted from one light-duty passenger vehicle (Buick Century; model year 1990; PM (particulate matter) mass emission rate 3.1 mg/km) and two light-duty trucks (Chevrolet C2; model year 1973; PM mass emission rate 282 mg/km, and Chevrolet El Camino; model year 1976; PM mass emission rate 31 mg/km), running California's unified driving cycles (UDC) on a chassis dynamometer, were studied using scanning electron microscopy (SEM). SEM images yielded particle properties including three-dimensional density fractal dimensions, monomer and agglomerate number size distributions, and three different shape descriptors, namely aspect ratio, root form factor, and roundness. The density fractal dimension of the particles was between 1.7 and 1.78, while the number size distribution of the particles placed the majority of the particles in the accumulation mode (0.1-0.3 microm). The shape descriptors were found to decrease with increasing particle size. Partial melting of particles, a rare and previously unreported phenomenon, was observed upon exposure of particles emitted during phase 2 of the UDC to the low accelerating voltage electron beam of the SEM. The rate of melting was quantified for individual particles, establishing a near linear relationship between the melting rate and the organic carbon 1 to elemental carbon ratio.

Secondary organic aerosol formation from road vehicle emissions

Science.gov (United States)

Pieber, Simone M.; Platt, Stephen M.; El Haddad, Imad; Zardini, Alessandro A.; Suarez-Bertoa, Ricardo; Slowik, Jay G.; Huang, Ru-Jin; Hellebust, Stig; Temime-Roussel, Brice; Marchand, Nicolas; Drinovec, Luca; Mocnik, Grisa; Baltensperger, Urs; Astorga, Covadogna; Prévôt, André S. H.

2014-05-01

Organic aerosol particles (OA) are a major fraction of the submicron particulate matter. OA consists of directly emitted primary (POA) and secondary OA (SOA). SOA is formed in-situ in the atmosphere via the reaction of volatile organic precursors. The partitioning of SOA species depends not only on the exposure to oxidants, but for instance also on temperature, relative humidity (RH), and the absorptive mass chemical composition (presence of inorganics) and concentration. Vehicle exhaust is a known source of POA and likely contributes to SOA formation in urban areas [1;2]. This has recently been estimated by (i) analyzing ambient data from urban areas combined with fuel consumption data [3], (ii) by examining the chemical composition of raw fuels [4], or (iii) smog chamber studies [5, 6]. Contradictory and thus somewhat controversial results in the relative quantity of SOA from diesel vs. gasoline vehicle exhaust were observed. In order to elucidate the impact of variable ambient conditions on the potential SOA formation of vehicle exhaust, and its relation to the emitted gas phase species, we studied SOA formed from the exhaust of passenger cars and trucks as a function of fuel and engine type (gasoline, diesel) at different temperatures (T 22 vs. -7oC) and RH (40 vs. 90%), as well as with different levels of inorganic salt concentrations. The exhaust was sampled at the tailpipe during regulatory driving cycles on chassis dynamometers, diluted (200 - 400x) and introduced into the PSI mobile smog chamber [6], where the emissions were subjected to simulated atmospheric ageing. Particle phase instruments (HR-ToF-AMS, aethalometers, CPC, SMPS) and gas phase instruments (PTR-TOF-MS, CO, CO2, CH4, THC, NH3 and other gases) were used online during the experiments. We found that gasoline emissions, because of cold starts, were generally larger than diesel, especially during cold temperatures driving cycles. Gasoline vehicles also showed the highest SOA formation

Joint measurements of black carbon and particle mass for heavy-duty diesel vehicles using a portable emission measurement system

Science.gov (United States)

The black carbon (BC) emitted from heavy-duty diesel vehicles(HDDVs) is an important source of urban atmospheric pollution and createsstrong climate-forcing impacts. The emission ratio of BC to totalparticle mass (PM) (i.e., BC/PM ratio) is an essential variable used toestimate t...

Exhaust particles of modern gasoline vehicles: A laboratory and an on-road study

Science.gov (United States)

Karjalainen, Panu; Pirjola, Liisa; Heikkilä, Juha; Lähde, Tero; Tzamkiozis, Theodoros; Ntziachristos, Leonidas; Keskinen, Jorma; Rönkkö, Topi

2014-11-01

Vehicle technology development and upcoming particle emission limits have increased the need for detailed analyses of particle emissions of vehicles using gasoline direct injection (GDI) techniques. In this paper the particle emission characteristics of modern GDI passenger cars were studied in a laboratory and on the road, with the focus on exhaust particle number emissions, size distributions, volatility and morphology. Both during acceleration and steady conditions the number size distribution of nonvolatile exhaust particles consisted of two modes, one with mean particle size below 30 nm and the other with mean particle size approximately 70 nm. Results indicate that both of these particles modes consisted of soot but with different morphologies. Both in laboratory and on the road, significant emissions of exhaust particles were observed also during decelerations conducted by engine braking. These particles are most likely originating from lubricant oil ash components. The semivolatile nucleation particles were observed in the laboratory experiments at high engine load conditions. Thus, in general, the study indicates that a modern gasoline vehicle can emit four distinctive types of exhaust particles. The differences in particle characteristics and formation should be taken into account in the development of emission control strategies and technologies and, on the other hand, in the assessment of the impact of particle emissions on environment and human health.

Blue-emitting LaSi3N5:Ce3+ fine powder phosphor for UV-converting white light-emitting diodes

Science.gov (United States)

Suehiro, Takayuki; Hirosaki, Naoto; Xie, Rong-Jun; Sato, Tsugio

2009-08-01

We have synthesized the pure ternary nitride phosphor, LaSi3N5:Ce3+ from the multicomponent oxide system La2O3-CeO2-SiO2, by using the gas-reduction-nitridation method. Highly pure, single-phase LaSi3N5:Ce3+ powders possessing particle sizes of ˜0.4-0.6 μm were obtained with the processing temperature ≤1500 °C. The synthesized LaSi3N5:Ce3+ exhibits tunable blue broadband emission with the dominant wavelength of 464-475 nm and the external quantum efficiency of ˜34%-67% under excitation of 355-380 nm. A high thermal stability of LaSi3N5:Ce3+ compared to the existing La-Si-O-N hosts was demonstrated, indicating the promising applicability as a blue-emitting phosphor for UV-converting white light-emitting diodes.

Detection of greenhouse gas precursors from ethanol powered vehicles in Brazil

International Nuclear Information System (INIS)

Tavares, Juliana R.; Sthel, Marcelo S.; Rocha, Mila V. da; Lima, Guilherme R.; Silva, Marcelo G. da; Vargas, Helion

2014-01-01

The use of fossil fuels on the transport sector has caused the emission of various air pollutants, which can cause numerous damages to the atmosphere and to human health. In order to minimize pollutant emission, Brazilian government has encouraged the use of alternatives fuels, such as ethanol. Ethanol can be a great ally in global warming mitigation due to its potential to reduce carbon dioxide emissions in its renewable cycle. Otherwise, other pollutant gases emitted during ethanol combustion can contribute directly or indirectly to intensify global warming. In this study, Photoacoustic and Electrochemical sensors were used to detect greenhouse precursor gases, such as carbon monoxide, nitrogen oxides and especially ethylene, a primary pollutant in the generation of tropospheric ozone, in the exhaust of ethanol powered vehicles, in the range of ppmv. - Highlights: • Using CO 2 and Quantum Cascade Laser Photoacoustic Spectrometer, we could prove the presence of ethylene in the exhaust of ethanol vehicles for the first time. • Photoacoustic technique has proven excellent requirements, such as selectivity, sensitivity, and portability for ethylene detection in the vehicles exhaust. • Using electrochemical sensors, we could detect CO and NO x in ethanol powered vehicles in ppmV range

Vehicle Detection with Occlusion Handling, Tracking, and OC-SVM Classification: A High Performance Vision-Based System

Science.gov (United States)

Velazquez-Pupo, Roxana; Sierra-Romero, Alberto; Torres-Roman, Deni; Shkvarko, Yuriy V.; Romero-Delgado, Misael

2018-01-01

This paper presents a high performance vision-based system with a single static camera for traffic surveillance, for moving vehicle detection with occlusion handling, tracking, counting, and One Class Support Vector Machine (OC-SVM) classification. In this approach, moving objects are first segmented from the background using the adaptive Gaussian Mixture Model (GMM). After that, several geometric features are extracted, such as vehicle area, height, width, centroid, and bounding box. As occlusion is present, an algorithm was implemented to reduce it. The tracking is performed with adaptive Kalman filter. Finally, the selected geometric features: estimated area, height, and width are used by different classifiers in order to sort vehicles into three classes: small, midsize, and large. Extensive experimental results in eight real traffic videos with more than 4000 ground truth vehicles have shown that the improved system can run in real time under an occlusion index of 0.312 and classify vehicles with a global detection rate or recall, precision, and F-measure of up to 98.190%, and an F-measure of up to 99.051% for midsize vehicles. PMID:29382078

Concept Design of High Power Solar Electric Propulsion Vehicles for Human Exploration

Science.gov (United States)

Hoffman, David J.; Kerslake, Thomas W.; Hojnicki, Jeffrey S.; Manzella, David H.; Falck, Robert D.; Cikanek, Harry A., III; Klem, Mark D.; Free, James M.

2011-01-01

Human exploration beyond low Earth orbit will require enabling capabilities that are efficient, affordable and reliable. Solar electric propulsion (SEP) has been proposed by NASA s Human Exploration Framework Team as one option to achieve human exploration missions beyond Earth orbit because of its favorable mass efficiency compared to traditional chemical propulsion systems. This paper describes the unique challenges associated with developing a large-scale high-power (300-kWe class) SEP vehicle and design concepts that have potential to meet those challenges. An assessment of factors at the subsystem level that must be considered in developing an SEP vehicle for future exploration missions is presented. Overall concepts, design tradeoffs and pathways to achieve development readiness are discussed.

Development of a Real-Time Smoke Belching Monitoring System for Public Utility Vehicles (PUV via GSM

Directory of Open Access Journals (Sweden)

Nelson C. Rodelas

2016-05-01

Full Text Available The Development of a Real-Time-Based Smoke Belching Monitoring System for Public Utility Vehicle is designed in order to monitor smoke belchers or violators among public utility vehicles (PUV that uses diesel such as jeepneys or buses. The concept of the project is to measure the opacity of the smoke being emitted by the PUV with the use of a predesigned sensor unit incorporated by Light Dependent Resistor Sensor and Light Source facing each other, 4 inches apart. By allowing the smoke to pass through the LDR and Light Source, the desired resistance is acquired and processed by the microcontroller to obtain the Light Absorption Coefficient. This value is the basis for being a smoke belcher (If it exceeds 2.5 k. The system then sends the data (Plate Number and K -value for every one (1 hour to the Database System and to the operator with the aid of GSM Microcontroller that leads to a real time monitoring. The system is possible to implement and has a potential to be used for emission testing centers since it has the features of the commercial opacity meter which is common in emission centers to measure the smoke emitted by the diesel-fueled vehicles. This project serves as an innovation in emission testing because it monitors the smoke belchers in real-time and operators or owners of the vehicle are not required anymore to go to the emission testing center every year to renew their car registration.

Chemical composition of gas-phase organic carbon emissions from motor vehicles and implications for ozone production.

Science.gov (United States)

Gentner, Drew R; Worton, David R; Isaacman, Gabriel; Davis, Laura C; Dallmann, Timothy R; Wood, Ezra C; Herndon, Scott C; Goldstein, Allen H; Harley, Robert A

2013-10-15

Motor vehicles are major sources of gas-phase organic carbon, which includes volatile organic compounds (VOCs) and other compounds with lower vapor pressures. These emissions react in the atmosphere, leading to the formation of ozone and secondary organic aerosol (SOA). With more chemical detail than previous studies, we report emission factors for over 230 compounds from gasoline and diesel vehicles via two methods. First we use speciated measurements of exhaust emissions from on-road vehicles in summer 2010. Second, we use a fuel composition-based approach to quantify uncombusted fuel components in exhaust using the emission factor for total uncombusted fuel in exhaust together with detailed chemical characterization of liquid fuel samples. There is good agreement between the two methods except for products of incomplete combustion, which are not present in uncombusted fuels and comprise 32 ± 2% of gasoline exhaust and 26 ± 1% of diesel exhaust by mass. We calculate and compare ozone production potentials of diesel exhaust, gasoline exhaust, and nontailpipe gasoline emissions. Per mass emitted, the gas-phase organic compounds in gasoline exhaust have the largest potential impact on ozone production with over half of the ozone formation due to products of incomplete combustion (e.g., alkenes and oxygenated VOCs). When combined with data on gasoline and diesel fuel sales in the U.S., these results indicate that gasoline sources are responsible for 69-96% of emissions and 79-97% of the ozone formation potential from gas-phase organic carbon emitted by motor vehicles.

A Witricity-Based High-Power Device for Wireless Charging of Electric Vehicles

Directory of Open Access Journals (Sweden)

Zhongyu Dai

2017-03-01

Full Text Available In this paper, a Witricity-based high-power device is proposed for wireless charging of electric vehicles. According to the specific requirements of three-stage charging for electric vehicles, four compensation modes of the Witricity system are analyzed by the Loosely Coupled Theory among transformer coils and the Substitution Theorem in circuit theory. In addition, when combining voltage withstand levels, the current withstand capability, the switching frequency of electronic switching tubes, and the features of the resonant circuit, the series-parallel (SP compensation mode is selected as the best compensation mode for matching the capacitor of the system. The performances of coils with different ferrite core arrangements are compared by simulations and models. The feasibility of the system is verified theoretically and the system functions are evaluated by the joint simulation of Simplorer and Maxwell. Finally, a Witricity-based high-power device is proposed as designed, and the correctness of theoretical analyses and simulation results are verified.

Radioluminescence of red-emitting Eu-doped phosphors for fiberoptic dosimetry

Energy Technology Data Exchange (ETDEWEB)

Molina, P.; Santiago, M.; Marcazzo, J.; Caselli, E. [Universidad Nacional del Centro de la Provincia de Buenos Aires, Instituto de Fisica Arroyo Seco, Pinto 399, 7000 Tandil (Argentina); Spano, F. [Autoridad Regulatoria Nuclear, Av. del Libertador 8250, 1429 Buenos Aires (Argentina); Henniger, J. [Institut fur Kern-und Teilchenphysik, Zellescher Weg 19, 01069 Dresden (Germany); Cravero, W., E-mail: pmolina@exa.unicen.edu.ar [Universidad Nacional del Sur, Departamento de Fisica, Av. Colon 80, 8000FTN Bahia Blanca, Buenos Aires (Argentina)

2011-10-15

The fiberoptic dosimetry technique (FOD) has become an attractive method for in-vivo real-time dosimetry in radiotherapy. It is based on the use of a tiny piece of scintillator coupled to the end of an optical fiber, which collects the light emitted by the scintillator during irradiation (radioluminescence). Carbon-doped aluminum oxide (Al{sub 2}O{sub 3}:C) is one of the most radioluminescence materials for FOD due to its high efficiency but it presents the drawback of emitting in the spectral region, where spurious luminescence is also important. Spurious luminescence from optical fiber, termed stem effect, is the main problem afflicting FOD. Several techniques have been applied to remove the stem effect. Optical filtering, which consists in using long-pass filters, is the simplest one. This technique is useful when red-emitting scintillators are employed. In this work, the feasibility of using red-emitting Eu-doped phosphors as FOD scintillators has been investigated. (Author)

Fiscal 1998 achievement report. Research and development of advanced clean energy vehicles; 1998 nendo kokoritsu clean energy jidosha no kenkyu kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The efforts aim to develop advanced clean energy vehicles (ACEVs) which drive on substitutes of oil low in pollution, consuming 1/2 or less energy and emitting 1/2 or less CO2 than the existing vehicles. Studies conducted in fiscal 1998 covered high-efficiency hybrid power systems and ACEVs. Efforts to develop ACEVs involved a reformed methanol fuel cell hybrid passenger car of Nissan Motor Co., Ltd. (improvement on element technologies, study of methanol concentration); CNG (compressed natural gas) engine hybrid passenger car of Honda Research and Development Co., Ltd. (improvement on flywheels, studies of ANG (adsorbent natural gas) adsorbent and ANG tank); CNG ceramics engine hybrid cargo truck of Isuzu Ceramics Research Institute Co., Ltd. (fabrication of ceramics single-cylinder engine, design and fabrication of vehicle control system, fabrication of prototype); CNG lean burn engine hybrid cargo truck of Mitsubishi Motors Co., Ltd. (studies, designing, and fabrication of engine element parts); LNG engine hybrid bus of Nissan Diesel Motor Co., Ltd. (development of engine and power storage); and DME (dimethylether) engine hybrid bus of Hino Motors, Ltd. (development of DME fuel injection system and high-efficiency power storage). (NEDO)

Aero-thermo-dynamic analysis of the Spaceliner-7.1 vehicle in high altitude flight

Science.gov (United States)

Zuppardi, Gennaro; Morsa, Luigi; Sippel, Martin; Schwanekamp, Tobias

2014-12-01

SpaceLiner, designed by DLR, is a visionary, extremely fast passenger transportation concept. It consists of two stages: a winged booster, a vehicle. After separation of the two stages, the booster makes a controlled re-entry and returns to the launch site. According to the current project, version 7-1 of SpaceLiner (SpaceLiner-7.1), the vehicle should be brought at an altitude of 75 km and then released, undertaking the descent path. In the perspective that the vehicle of SpaceLiner-7.1 could be brought to altitudes higher than 75 km, e.g. 100 km or above and also for a speculative purpose, in this paper the aerodynamic parameters of the SpaceLiner-7.1 vehicle are calculated in the whole transition regime, from continuum low density to free molecular flows. Computer simulations have been carried out by three codes: two DSMC codes, DS3V in the altitude interval 100-250 km for the evaluation of the global aerodynamic coefficients and DS2V at the altitude of 60 km for the evaluation of the heat flux and pressure distributions along the vehicle nose, and the DLR HOTSOSE code for the evaluation of the global aerodynamic coefficients in continuum, hypersonic flow at the altitude of 44.6 km. The effectiveness of the flaps with deflection angle of -35 deg. was evaluated in the above mentioned altitude interval. The vehicle showed longitudinal stability in the whole altitude interval even with no flap. The global bridging formulae verified to be proper for the evaluation of the aerodynamic coefficients in the altitude interval 80-100 km where the computations cannot be fulfilled either by CFD, because of the failure of the classical equations computing the transport coefficients, or by DSMC because of the requirement of very high computer resources both in terms of the core storage (a high number of simulated molecules is needed) and to the very long processing time.

Cuprous halides semiconductors as a new means for highly efficient light-emitting diodes

Science.gov (United States)

Ahn, Doyeol; Park, Seoung-Hwan

2016-01-01

In group-III nitrides in use for white light-emitting diodes (LEDs), optical gain, measure of luminous efficiency, is very low owing to the built-in electrostatic fields, low exciton binding energy, and high-density misfit dislocations due to lattice-mismatched substrates. Cuprous halides I-VII semiconductors, on the other hand, have negligible built-in field, large exciton binding energies and close lattice matched to silicon substrates. Recent experimental studies have shown that the luminescence of I-VII CuCl grown on Si is three orders larger than that of GaN at room temperature. Here we report yet unexplored potential of cuprous halides systems by investigating the optical gain of CuCl/CuI quantum wells. It is found that the optical gain and the luminescence are much larger than that of group III-nitrides due to large exciton binding energy and vanishing electrostatic fields. We expect that these findings will open up the way toward highly efficient cuprous halides based LEDs compatible to Si technology. PMID:26880097

A novel double perovskite tellurate Eu3+-doped Sr2MgTeO6 red-emitting phosphor with high thermal stability

Science.gov (United States)

Liang, Jingyun; Zhao, Shancang; Yuan, Xuexia; Li, Zengmei

2018-05-01

A series of novel double perovskite tellurate red-emitting phosphors Sr2MgTeO6:xEu3+ (x = 0.05-0.40) were successfully synthesized by a high-temperature solid-state reaction method. The phase structure, photoluminescence properties and thermal stability of the phosphor were investigated in detail. The phosphor shows dominant emission peak at 614 nm belonging to the 5D0 → 7F2 electric dipole transition under 465 nm excitation. The luminescence intensity keeps increasing with increasing the content of Eu3+ to 25 mol%, and the critical transfer distance of Eu3+ was calculated to be 12 Å. The quenching temperature for Sr2MgTeO6:0.25Eu3+ was estimated to be above 500 K. This spectral feature reveals high color purity and excellent chromaticity coordinate characteristics. Therefore, Eu3+-doped Sr2MgTeO6 phosphors are potential red phosphors for blue chip-based white light-emitting diode and display devices.

High performance modeling of atmospheric re-entry vehicles

International Nuclear Information System (INIS)

Martin, Alexandre; Scalabrin, Leonardo C; Boyd, Iain D

2012-01-01

Re-entry vehicles designed for space exploration are usually equipped with thermal protection systems made of ablative material. In order to properly model and predict the aerothermal environment of the vehicle, it is imperative to account for the gases produced by ablation processes. In the case of charring ablators, where an inner resin is pyrolyzed at a relatively low temperature, the composition of the gas expelled into the boundary layer is complex and may lead to thermal chemical reactions that cannot be captured with simple flow chemistry models. In order to obtain better predictions, an appropriate gas flow chemistry model needs to be included in the CFD calculations. Using a recently developed chemistry model for ablating carbon-phenolic-in-air species, a CFD calculation of the Stardust re-entry at 71 km is presented. The code used for that purpose has been designed to take advantage of the nature of the problem and therefore remains very efficient when a high number of chemical species are involved. The CFD result demonstrates the need for such chemistry model when modeling the flow field around an ablative material. Modeling of the nonequilibrium radiation spectra is also presented, and compared to the experimental data obtained during Stardust re-entry by the Echelle instrument. The predicted emission from the CN lines compares quite well with the experimental results, demonstrating the validity of the current approach.

Modeling of in-vehicle magnetic refrigeration

DEFF Research Database (Denmark)

Olsen, Ulrik Lund; Bahl, Christian R.H.; Engelbrecht, Kurt

2014-01-01

A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose...

Modeling of In-vehicle Magnetic refrigeration

DEFF Research Database (Denmark)

Olsen, Ulrik Lund; Bahl, Christian; Engelbrecht, Kurt

2012-01-01

A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose...

A highly luminescent dinuclear Eu(III) complex based on 4,4'-bis (4'',4'',4''-trifluoro-1'',3''-dioxobutyl)-o-terphenyl for light-emitting diodes

International Nuclear Information System (INIS)

Liu Shenggui; He Pei; Wang Huihui; Shi Jianxin; Gong Menglian

2009-01-01

A dinuclear Eu(III) complex Eu 2 (btbt) 3 .4H 2 O.CH 3 CH 2 OH.N(CH 2 CH 3 ) 3 was synthesized, where H 2 (btbt) was 4,4'-bis (4'',4'',4'',-trifluoro-1'',3''-dioxobutyl)-o-terphenyl. The composition and structure of the complex were characterized by elemental analysis, IR, UV-vis and FAB-MS spectroscopy. The complex emits the characteristic red luminescence of Eu 3+ ion due to the 5 D 0 → 7 F J (J = 0-4) transitions under ∼395 nm-light excitation with good luminescent quantum efficiency (32%) and exhibits high thermal stability (337 deg. C). Bright red light-emitting diodes (LEDs) were fabricated by coating the complex onto a ∼395 nm-emitting InGaN chip. When the mass ratio of the red phosphor to the silicone is 1:30, the efficiency of the fabricated LEDs with the europium complex is 0.98 lm w -1 . The CIE chromaticity coordinates of the LEDs are x = 0.6057 and y = 0.3137, which are close to the National Television Standard Committee (NTSC) standard values for red color. The results indicate that the complex may act as a red component in the fabrication of near UV InGaN-based white light-emitting diodes with high color-rendering index.

Investigating the Mobility of Light Autonomous Tracked Vehicles using a High Performance Computing Simulation Capability

Science.gov (United States)

Negrut, Dan; Mazhar, Hammad; Melanz, Daniel; Lamb, David; Jayakumar, Paramsothy; Letherwood, Michael; Jain, Abhinandan; Quadrelli, Marco

2012-01-01

This paper is concerned with the physics-based simulation of light tracked vehicles operating on rough deformable terrain. The focus is on small autonomous vehicles, which weigh less than 100 lb and move on deformable and rough terrain that is feature rich and no longer representable using a continuum approach. A scenario of interest is, for instance, the simulation of a reconnaissance mission for a high mobility lightweight robot where objects such as a boulder or a ditch that could otherwise be considered small for a truck or tank, become major obstacles that can impede the mobility of the light autonomous vehicle and negatively impact the success of its mission. Analyzing and gauging the mobility and performance of these light vehicles is accomplished through a modeling and simulation capability called Chrono::Engine. Chrono::Engine relies on parallel execution on Graphics Processing Unit (GPU) cards.

Tyre influences on untripped vehicle rollover

NARCIS (Netherlands)

Jansen, S.T.H.; Lupker, H.A.; Koppenaal, C.J.P.

2002-01-01

Vehicle rollover can be initiated by steering actions that occur at vehicle evasive manoeuvres or high speed cornering of commercial vehicles. This untripped vehicle rollover is more difficult to reproduce for passenger cars then for commercial vehicles. For passenger cars it occurs closer to the

Versatile Tri(pyrazolyl)phosphanes as Phosphorus Precursors for the Synthesis of Highly Emitting InP/ZnS Quantum Dots.

Science.gov (United States)

Panzer, René; Guhrenz, Chris; Haubold, Danny; Hübner, René; Gaponik, Nikolai; Eychmüller, Alexander; Weigand, Jan J

2017-11-13

Tri(pyrazolyl)phosphanes (5 R1,R2 ) are utilized as an alternative, cheap and low-toxic phosphorus source for the convenient synthesis of InP/ZnS quantum dots (QDs). From these precursors, remarkably long-term stable stock solutions (>6 months) of P(OLA) 3 (OLAH=oleylamine) are generated from which the respective pyrazoles are conveniently recovered. P(OLA) 3 acts simultaneously as phosphorus source and reducing agent in the synthesis of highly emitting InP/ZnS core/shell QDs. These QDs are characterized by a spectral range between 530-620 nm and photoluminescence quantum yields (PL QYs) between 51-62 %. A proof-of-concept white light-emitting diode (LED) applying the InP/ZnS QDs as a color-conversion layer was built to demonstrate their applicability and processibility. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-efficiency tris(8-hydroxyquinoline)aluminum (Alq3) complexes for organic white-light-emitting diodes and solid-state lighting.

Science.gov (United States)

Pérez-Bolívar, César; Takizawa, Shin-ya; Nishimura, Go; Montes, Victor A; Anzenbacher, Pavel

2011-08-08

Combinations of electron-withdrawing and -donating substituents on the 8-hydroxyquinoline ligand of the tris(8-hydroxyquinoline)aluminum (Alq(3)) complexes allow for control of the HOMO and LUMO energies and the HOMO-LUMO gap responsible for emission from the complexes. Here, we present a systematic study on tuning the emission and electroluminescence (EL) from Alq(3) complexes from the green to blue region. In this study, we explored the combination of electron-donating substituents on C4 and C6. Compounds 1-6 displayed the emission tuning between 478 and 526 nm, and fluorescence quantum yield between 0.15 and 0.57. The compounds 2-6 were used as emitters and hosts in organic light-emitting diodes (OLEDs). The highest OLED external quantum efficiency (EQE) observed was 4.6%, which is among the highest observed for Alq(3) complexes. Also, the compounds 3-5 were used as hosts for red phosphorescent dopants to obtain white light-emitting diodes (WOLED). The WOLEDs displayed high efficiency (EQE up to 19%) and high white color purity (color rendering index (CRI≈85). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluating the accuracy of vehicle tracking data obtained from Unmanned Aerial Vehicles

Directory of Open Access Journals (Sweden)

Giuseppe Guido

2016-10-01

Full Text Available This paper presents a methodology for tracking moving vehicles that integrates Unmanned Aerial Vehicles with video processing techniques. The authors investigated the usefulness of Unmanned Aerial Vehicles to capture reliable individual vehicle data by using GPS technology as a benchmark. A video processing algorithm for vehicles trajectory acquisition is introduced. The algorithm is based on OpenCV libraries. In order to assess the accuracy of the proposed video processing algorithm an instrumented vehicle was equipped with a high precision GPS. The video capture experiments were performed in two case studies. From the field, about 24,000 positioning data were acquired for the analysis. The results of these experiments highlight the versatility of the Unmanned Aerial Vehicles technology combined with video processing technique in monitoring real traffic data.

Vehicle charging and return current measurements during electron-beam emission experiments from the Shuttle Orbiter

International Nuclear Information System (INIS)

Hawkins, J.G.

1988-01-01

The prime objective of this research was to investigate the electro-dynamic response of the Shuttle Orbiter during electron beam emission from the payload bay. This investigation has been conducted by examining data collected by the Vehicle Charging And Potential (VCAP) Experiment. The VCAP experiment has flown on two Shuttle missions with a Fast Pulse Electron Generator (FPEG) capable of emitting a 100 mA beam of 1 keV electrons. Diagnostics of the charging and return current during beam emission were provided by a combined Charge and Current Probe (CCP) located in the payload bay of the Orbiter. The CCP measurements were used to conduct a parametric study of the vehicle charging and return current as a function of vehicle attitude, ambient plasma parameters, and emitted beam current. In particular, the CCP measurements were found to depend strongly on the ambient plasma density. The vehicle charging during a 100 mA beam emission was small when the predicted ambient plasma density was greater than 3 x 10 5 cm -3 , but appreciable charging occurred when the density was less than this value. These observations indicated that the effective current-collecting area of the Orbiter is approximately 42 m 2 , consistent with estimates for the effective area of the Orbiter's engine nozzles. The operation of the Orbiter's Reaction Control System thrusters can create perturbations in the Orbiter's neutral and plasma environment that affect the CCP measurements. The CCP signatures of thruster firings are quite complex, but in general they are consistent with the depletion of plasma density in the ram direction and the enhancement of plasma density in the Orbiter's wake

Exciplex-Forming Cohost for High Efficiency and High Stability Phosphorescent Organic Light-Emitting Diodes.

Science.gov (United States)

Shih, Chun-Jen; Lee, Chih-Chien; Chen, Ying-Hao; Biring, Sajal; Kumar, Gautham; Yeh, Tzu-Hung; Sen, Somaditya; Liu, Shun-Wei; Wong, Ken-Tsung

2018-01-17

An exciplex forming cohost system is employed to achieve a highly efficient organic light-emitting diode (OLED) with good electroluminescent lifetime. The exciplex is formed at the interfacial contact of a conventional star-shaped carbazole hole-transporting material, 4,4',4″-tris(N-carbazolyl)-triphenylamine (TCTA), and a triazine electron-transporting material, 2,4,6-tris[3-(1H-pyrazol-1-yl)phenyl]-1,3,5-triazine (3P-T2T). The excellent combination of TCTA and 3P-T2T is applied as the cohost of a common green phosphorescent emitter with almost zero energy loss. When Ir(ppy) 2 (acac) is dispersed in such exciplex cohost system, OLED device with maximum external quantum efficiency of 29.6%, the ultrahigh power efficiency of 147.3 lm/W, and current efficiency of 107 cd/A were successfully achieved. More importantly, the OLED device showed a low-efficiency roll-off and an operational lifetime (τ 80 ) of ∼1020 min with the initial brightness of 2000 cd/m 2 , which is 56 times longer than the reference device. The significant difference of device stability was attributed to the degradation of exciplex system for energy transfer process, which was investigated by the photoluminescence aging measurement at room temperature and 100 K, respectively.

Levitation characteristics of a high-temperature superconducting Maglev system for launching space vehicles

International Nuclear Information System (INIS)

Yang Wenjiang; Liu Yu; Chen Xiaodong; Wen Zheng; Duan Yi; Qiu Ming

2007-01-01

Maglev launch assist is viewed as an effective method to reduce the cost of space launch. The primary aerodynamic characteristics of the Maglev launch vehicle and the space vehicle are discussed by analyzing their aerodynamic shapes and testing a scale mode in a standard wind tunnel. After analyzing several popular Maglev systems, we present a no-controlling Maglev system with bulk YBaCuO high-temperature superconductors (HTSs). We tested a HTS Maglev system unit, and obtained the levitation force density of 3.3 N/cm 2 and the lateral force density of 2.0 N/cm 2 . We also fabricated a freely levitated test platform to investigate the levitation characteristics of the HTS Maglev system in load changing processes. We found that the HTS system could provide the strong self-stable levitation performance due to the magnetic flux trapped in superconductors. The HTS Maglev system provided feasibility for application in the launch vehicle

Emerging applications for vertical cavity surface emitting lasers

International Nuclear Information System (INIS)

Harris, J S; O'sullivan, T; Sarmiento, T; Lee, M M; Vo, S

2011-01-01

Vertical cavity surface emitting lasers (VCSELs) emitting at 850 nm have experienced explosive growth in the past decade because of their many attractive optical features and incredibly low-cost manufacturability. This review reviews the foundations for GaAs-based VCSEL technology as well as the materials and device challenges to extend the operating wavelength to both shorter and longer wavelengths. We discuss some of the applications that are enabled by the integration of VCSELs with both active and passive semiconductor elements for telecommunications, both in vivo and in vitro biosensing, high-density optical storage and imaging at wavelengths much less than the diffraction limit of light

Ring cavity surface emitting semiconductor lasers

International Nuclear Information System (INIS)

Mujagic, E.

2010-01-01

Quantum cascade lasers (QCLs) are electrically driven semiconductor lasers, which have undergone a steady improvement since the first demonstration in 1994. These are now well established as reliable sources of coherent light in the mid-infrared (MIR) and terahertz (THz)range of the electromagnetic spectrum (3-300 μm). The rapid progress of this type of lasers is based on a high degree of freedom in tailoring the emission wavelength within a large variety of semiconductor heterostructure designs and materials. These properties have attracted the attention of various applications such as gas analysis, chemical sensing, spectral imaging and free-space telecommunication. In order to improve the selectivity, sensitivity and efficiency of today's sensor systems, high optical power, continuous wave and room temperature performance, single-mode operation and low divergence optical beams, are highly desirable qualities of a compact laser source in this field of research. Since all of these features cannot be provided by a conventional edge-emitting device at the same time, research has put focus on the development of surface emitting devices. Nowadays, the vertical cavity surface emitting lasers (VCSELs) are the most prominent representative for this type of light emitters. With its capability of producing narrow circular beams, the feasibility of two-dimensional arrays and on-wafer testing, such a coherent light source results in a reduction of the fabrication effort and production costs. Since the radiation in QCLs is strictly polarized normal to the epitaxial layer plane, fabrication of VCSELs based on QC structures is not viable. The subject of this work is the design and realization of 'ring cavity surface emitting lasers' (ring-CSELs). This type of lasers employs a circular ring cavity and a resonant distributed feedback (DFB) surface grating. Ring-CSELs were fabricated on the basis of MIR and THz QC structures, which cover a wavelength range from 4 μm to 93 �

A High Power Density Integrated Charger for Electric Vehicles with Active Ripple Compensation

OpenAIRE

Pan, Liwen; Zhang, Chengning

2015-01-01

This paper suggests a high power density on-board integrated charger with active ripple compensation circuit for electric vehicles. To obtain a high power density and high efficiency, silicon carbide devices are reported to meet the requirement of high-switching-frequency operation. An integrated bidirectional converter is proposed to function as AC/DC battery charger and to transfer energy between battery pack and motor drive of the traction system. In addition, the conventional H-bridge cir...

Plug-in Hybrid Electric Vehicle Value Proposition Study - Final Report

Energy Technology Data Exchange (ETDEWEB)

Sikes, Karen [Sentech, Inc.; Hadley, Stanton W [ORNL; McGill, Ralph N [ORNL; Cleary, Timothy [Sentech, Inc.

2010-07-01

PHEVs have been the subject of growing interest in recent years because of their potential for reduced operating costs, oil displacement, national security, and environmental benefits. Despite the potential long-term savings to consumers and value to stakeholders, the initial cost of PHEVs presents a major market barrier to their widespread commercialization. The study Objectives are: (1) To identify and evaluate value-added propositions for PHEVs that will help overcome the initial price premium relative to comparable ICEs and HEVs and (2) to assess other non-monetary benefits and barriers associated with an emerging PHEV fleet, including environmental, societal, and grid impacts. Study results indicate that a single PHEV-30 on the road in 2030 will: (1) Consume 65% and 75% less gasoline than a comparable HEV and ICE, respectively; (2) Displace 7.25 and 4.25 barrels of imported oil each year if substituted for equivalent ICEs and HEVs, respectively, assuming 60% of the nation's oil consumed is imported; (3) Reduce net ownership cost over 10 years by 8-10% relative to a comparable ICE and be highly cost competitive with a comparable HEV; (4) Use 18-22% less total W2W energy than a comparable ICE, but 8-13% more than a comparable HEV (assuming a 70/30 split of E10 and E85 use in 2030); and (5) Emit 10% less W2W CO{sub 2} than equivalent ICEs in southern California and emits 13% more W2W CO{sub 2} than equivalent ICEs in the ECAR region. This also assumes a 70/30 split of E10 and E85 use in 2030. PHEVs and other plug-in vehicles on the road in 2030 may offer many valuable benefits to utilities, business owners, individual consumers, and society as a whole by: (1) Promoting national energy security by displacing large volumes of imported oil; (2) Supporting a secure economy through the expansion of domestic vehicle and component manufacturing; (3) Offsetting the vehicle's initial price premium with lifetime operating cost savings (e.g., lower fuel and

Aspect-dependent radiated noise analysis of an underway autonomous underwater vehicle.

Science.gov (United States)

Gebbie, John; Siderius, Martin; Allen, John S

2012-11-01

This paper presents an analysis of the acoustic emissions emitted by an underway REMUS-100 autonomous underwater vehicle (AUV) that were obtained near Honolulu Harbor, HI using a fixed, bottom-mounted horizontal line array (HLA). Spectral analysis, beamforming, and cross-correlation facilitate identification of independent sources of noise originating from the AUV. Fusion of navigational records from the AUV with acoustic data from the HLA allows for an aspect-dependent presentation of calculated source levels of the strongest propulsion tone.

High modulation bandwidth of a light-emitting diode with surface plasmon coupling (Conference Presentation)

Science.gov (United States)

Lin, Chun-Han; Tu, Charng-Gan; Yao, Yu-Feng; Chen, Sheng-Hung; Su, Chia-Ying; Chen, Hao-Tsung; Kiang, Yean-Woei; Yang, Chih-Chung

2017-02-01

Besides lighting, LEDs can be used for indoor data transmission. Therefore, a large modulation bandwidth becomes an important target in the development of visible LED. In this regard, enhancing the radiative recombination rate of carriers in the quantum wells of an LED is a useful method since the modulation bandwidth of an LED is related to the carrier decay rate besides the device RC time constant To increase the carrier decay rate in an LED without sacrificing its output power, the technique of surface plasmon (SP) coupling in an LED is useful. In this paper, the increases of modulation bandwidth by reducing mesa size, decreasing active layer thickness, and inducing SP coupling in blue- and green-emitting LEDs are illustrated. The results are demonstrated by comparing three different LED surface structures, including bare p-type surface, GaZnO current spreading layer, and Ag nanoparticles (NPs) for inducing SP coupling. In a single-quantum-well, blue-emitting LED with a circular mesa of 10 microns in radius, SP coupling results in a modulation bandwidth of 528.8 MHz, which is believed to be the record-high level. A smaller RC time constant can lead to a higher modulation bandwidth. However, when the RC time constant is smaller than 0.2 ns, its effect on modulation bandwidth saturates. The dependencies of modulation bandwidth on injected current density and carrier decay time confirm that the modulation bandwidth is essentially inversely proportional to a time constant, which is inversely proportional to the square-root of carrier decay rate and injected current density.

White emitting CdS quantum dot nanoluminophores hybridized on near-ultraviolet LEDs for high-quality white light generation and tuning

International Nuclear Information System (INIS)

Nizamoglu, Sedat; Mutlugun, Evren; Akyuz, Ozgun; Perkgoz, Nihan Kosku; Demir, Hilmi Volkan; Liebscher, Lydia; Sapra, Sameer; Gaponik, Nikolai; Eychmueller, Alexander

2008-01-01

To generate white light using semiconductor nanocrystal (NC) quantum dots integrated on light emitting diodes (LEDs), multiple hybrid device parameters (emission wavelengths of the NCs and the excitation platform, order of the NCs with different sizes, amount of the different types of NCs, etc) need to be carefully designed and properly implemented. In this study, we introduce and demonstrate white LEDs based on simple device hybridization using only a single type of white emitting CdS quantum dot nanoluminophores on near-ultraviolet LEDs. Here we present their design, synthesis-growth, fabrication and characterization. With these hybrid devices, we achieve high color rendering index (>70), despite using only a single NC type. Furthermore, we conveniently tune their photometric properties including the chromaticity coordinates, correlated color temperature, and color rendering index with the number of hybridized nanoluminophores in a controlled manner

Development of a highly maneuverable unmanned underwater vehicle on the basis of quad-copter dynamics

Science.gov (United States)

Amin, Osman Md; Karim, Md. Arshadul; Saad, Abdullah His

2017-12-01

At present, research on unmanned underwater vehicle (UUV) has become a significant & familiar topic for researchers from various engineering fields. UUV is of mainly two types - AUV (Autonomous Underwater vehicle) & ROV (Remotely Operated Vehicle). There exist a significant number of published research papers on UUV, where very few researchers emphasize on the ease of maneuvering and control of UUV. Maneuvering is important for underwater vehicle in avoiding obstacles, installing underwater piping system, searching undersea resources, underwater mine disposal operations, oceanographic surveys etc. A team from Dept. of Naval Architecture & Marine Engineering of MIST has taken a project to design a highly maneuverable unmanned underwater vehicle on the basis of quad-copter dynamics. The main objective of the research is to develop a control system for UUV which would be able to maneuver the vehicle in six DOF (Degrees of Freedom) with great ease. For this purpose we are not only focusing on controllability but also designing an efficient hull with minimal drag force & optimized propeller using CFD technique. Motors were selected on the basis of the simulated thrust generated by propellers in ANSYS Fluent software module. Settings for control parameters to carry out different types of maneuvering such as hovering, spiral, one point rotation about its centroid, gliding, rolling, drifting and zigzag motions were explained in short at the end.

Cooperative control of UAVs for localization of intermittently emitting mobile targets.

Science.gov (United States)

Pack, Daniel J; Delima, Pedro; Toussaint, Gregory J; York, George

2009-08-01

Compared with a single platform, cooperative autonomous unmanned aerial vehicles (UAVs) offer efficiency and robustness in performing complex tasks. Focusing on ground mobile targets that intermittently emit radio frequency signals, this paper presents a decentralized control architecture for multiple UAVs, equipped only with rudimentary sensors, to search, detect, and locate targets over large areas. The proposed architecture has in its core a decision logic which governs the state of operation for each UAV based on sensor readings and communicated data. To support the findings, extensive simulation results are presented, focusing primarily on two success measures that the UAVs seek to minimize: overall time to search for a group of targets and the final target localization error achieved. The results of the simulations have provided support for hardware flight tests.

Evaluation of high-energy brachytherapy source electronic disequilibrium and dose from emitted electrons.

Science.gov (United States)

Ballester, Facundo; Granero, Domingo; Pérez-Calatayud, José; Melhus, Christopher S; Rivard, Mark J

2009-09-01

The region of electronic disequilibrium near photon-emitting brachytherapy sources of high-energy radionuclides (60Co, 137CS, 192Ir, and 169Yb) and contributions to total dose from emitted electrons were studied using the GEANT4 and PENELOPE Monte Carlo codes. Hypothetical sources with active and capsule materials mimicking those of actual sources but with spherical shape were examined. Dose contributions due to source photons, x rays, and bremsstrahlung; source beta-, Auger electrons, and internal conversion electrons; and water collisional kerma were scored. To determine if conclusions obtained for electronic equilibrium conditions and electron dose contribution to total dose for the representative spherical sources could be applied to actual sources, the 192Ir mHDR-v2 source model (Nucletron B.V., Veenendaal, The Netherlands) was simulated for comparison to spherical source results and to published data. Electronic equilibrium within 1% is reached for 60Co, 137CS, 192Ir, and 169Yb at distances greater than 7, 3.5, 2, and 1 mm from the source center, respectively, in agreement with other published studies. At 1 mm from the source center, the electron contributions to total dose are 1.9% and 9.4% for 60Co and 192Ir, respectively. Electron emissions become important (i.e., > 0.5%) within 3.3 mm of 60Co and 1.7 mm of 192Ir sources, yet are negligible over all distances for 137Cs and 169Yb. Electronic equilibrium conditions along the transversal source axis for the mHDR-v2 source are comparable to those of the spherical sources while electron dose to total dose contribution are quite different. Electronic equilibrium conditions obtained for spherical sources could be generalized to actual sources while electron contribution to total dose depends strongly on source dimensions, material composition, and electron spectra.

Irradiation Pattern Analysis for Designing Light Sources-Based on Light Emitting Diodes

International Nuclear Information System (INIS)

Rojas, E.; Stolik, S.; La Rosa, J. de; Valor, A.

2016-01-01

Nowadays it is possible to design light sources with a specific irradiation pattern for many applications. Light Emitting Diodes present features like high luminous efficiency, durability, reliability, flexibility, among others as the result of its rapid development. In this paper the analysis of the irradiation pattern of the light emitting diodes is presented. The approximation of these irradiation patterns to both, a Lambertian, as well as a Gaussian functions for the design of light sources is proposed. Finally, the obtained results and the functionality of bringing the irradiation pattern of the light emitting diodes to these functions are discussed. (Author)

Manipulating Ion Migration for Highly Stable Light-Emitting Diodes with Single-Crystalline Organometal Halide Perovskite Microplatelets.

Science.gov (United States)

Chen, Mingming; Shan, Xin; Geske, Thomas; Li, Junqiang; Yu, Zhibin

2017-06-27

Ion migration has been commonly observed as a detrimental phenomenon in organometal halide perovskite semiconductors, causing the measurement hysteresis in solar cells and ultrashort operation lifetimes in light-emitting diodes. In this work, ion migration is utilized for the formation of a p-i-n junction at ambient temperature in single-crystalline organometal halide perovskites. The junction is subsequently stabilized by quenching the ionic movement at a low temperature. Such a strategy of manipulating the ion migration has led to efficient single-crystalline light-emitting diodes that emit 2.3 eV photons starting at 1.8 V and sustain a continuous operation for 54 h at ∼5000 cd m -2 without degradation of brightness. In addition, a whispering-gallery-mode cavity and exciton-exciton interaction in the perovskite microplatelets have both been observed that can be potentially useful for achieving electrically driven laser diodes based on single-crystalline organometal halide perovskite semiconductors.

A quasi-vehicle/bridge interaction model for high speed railways

Czech Academy of Sciences Publication Activity Database

Yau, J. D.; Frýba, Ladislav

2015-01-01

Roč. 31, č. 2 (2015), s. 217-225 ISSN 1727-7191 R&D Projects: GA ČR(CZ) GA103/08/1340 Grant - others:National Science Council in Taiwan(TW) NSC 102-2923-E-032-002-MY3 Institutional support: RVO:68378297 Keywords : high speed train * quasi-VBI model * resonance * vehicle-bridge interaction Subject RIV: JM - Building Engineering Impact factor: 0.828, year: 2015 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9645645&fileId=S1727719114000896

Vehicle to grid: electric vehicles as an energy storage solution

Science.gov (United States)

McGee, Rodney; Waite, Nicholas; Wells, Nicole; Kiamilev, Fouad E.; Kempton, Willett M.

2013-05-01

With increased focus on intermittent renewable energy sources such as wind turbines and photovoltaics, there comes a rising need for large-scale energy storage. The vehicle to grid (V2G) project seeks to meet this need using electric vehicles, whose high power capacity and existing power electronics make them a promising energy storage solution. This paper will describe a charging system designed by the V2G team that facilitates selective charging and backfeeding by electric vehicles. The system consists of a custom circuit board attached to an embedded linux computer that is installed both in the EVSE (electric vehicle supply equipment) and in the power electronics unit of the vehicle. The boards establish an in-band communication link between the EVSE and the vehicle, giving the vehicle internet connectivity and the ability to make intelligent decisions about when to charge and discharge. This is done while maintaining compliance with existing charging protocols (SAEJ1772, IEC62196) and compatibility with standard "nonintelligent" cars and chargers. Through this system, the vehicles in a test fleet have been able to successfully serve as portable temporary grid storage, which has implications for regulating the electrical grid, providing emergency power, or supplying power to forward military bases.

Novel green-emitting Na2CaPO4F:Eu2+ phosphors for near-ultraviolet white light-emitting diodes

International Nuclear Information System (INIS)

Huang, Chien-Hao; Chen, Yen-Chi; Kuo, Te-Wen; Chen, Teng-Ming

2011-01-01

In this study, green-emitting Na 2 CaPO 4 F:Eu 2+ phosphors were synthesized by solid-state reactions. The excitation spectra of the phosphors showed a broad hump between 250 and 450 nm; the spectra match well with the near-ultraviolet (NUV) emission spectra of light-emitting diodes (LEDs). The emission spectrum showed an intense broad emission band centered at 506 nm. White LEDs were fabricated by integrating a 390 nm NUV chip comprising blue-emitting BaMgAl 10 O 17 :Eu 2+ , green-emitting Na 2 CaPO 4 F:0.02 Eu 2+ , and red-emitting CaAlSiN 3 :Eu 2+ phosphors into a single package; the white LEDs exhibited white light with a correlated color temperature of 5540 K, a color-rendering index of 90.75, and color coordinates (0.332, 0.365) close to those of ideal white light. - Highlights: → Novel green-emitting Na 2 CaPO 4 F:Eu 2+ phosphors were synthesized by solid-state reactions in this research. → White LEDs were fabricated by integrating a 390 nm NUV chip comprising blue-emitting BaMgAl 10 O 17 :Eu 2+ , green-emitting Na 2 CaPO 4 F:0.02Eu 2+ , and red-emitting CaAlSiN 3 :Eu 2+ phosphors into a single package. → The white LEDs exhibited white light with a correlated color temperature of 5540 K, a color-rendering index of 90.75, and color coordinates (0.332, 0.365) close to those of ideal white light.

Response of conifer species from three latitudinal populations to light spectra generated by light-emitting diodes and high-pressure sodium lamps

Science.gov (United States)

Kent G. Apostol; Kas Dumroese; Jeremy Pinto; Anthony S. Davis

2015-01-01

Light-emitting diode (LED) technology shows promise for supplementing photosynthetically active radiation (PAR) in forest nurseries because of the potential reduction in energy consumption and an ability to supply discrete wavelengths to optimize seedling growth. Our objective was to examine the effects of light spectra supplied by LED and traditional high-pressure...

Scalable Light Module for Low-Cost, High-Efficiency Light- Emitting Diode Luminaires

Energy Technology Data Exchange (ETDEWEB)

Tarsa, Eric [Cree, Inc., Goleta, CA (United States)

2015-08-31

During this two-year program Cree developed a scalable, modular optical architecture for low-cost, high-efficacy light emitting diode (LED) luminaires. Stated simply, the goal of this architecture was to efficiently and cost-effectively convey light from LEDs (point sources) to broad luminaire surfaces (area sources). By simultaneously developing warm-white LED components and low-cost, scalable optical elements, a high system optical efficiency resulted. To meet program goals, Cree evaluated novel approaches to improve LED component efficacy at high color quality while not sacrificing LED optical efficiency relative to conventional packages. Meanwhile, efficiently coupling light from LEDs into modular optical elements, followed by optimally distributing and extracting this light, were challenges that were addressed via novel optical design coupled with frequent experimental evaluations. Minimizing luminaire bill of materials and assembly costs were two guiding principles for all design work, in the effort to achieve luminaires with significantly lower normalized cost ($/klm) than existing LED fixtures. Chief project accomplishments included the achievement of >150 lm/W warm-white LEDs having primary optics compatible with low-cost modular optical elements. In addition, a prototype Light Module optical efficiency of over 90% was measured, demonstrating the potential of this scalable architecture for ultra-high-efficacy LED luminaires. Since the project ended, Cree has continued to evaluate optical element fabrication and assembly methods in an effort to rapidly transfer this scalable, cost-effective technology to Cree production development groups. The Light Module concept is likely to make a strong contribution to the development of new cost-effective, high-efficacy luminaries, thereby accelerating widespread adoption of energy-saving SSL in the U.S.

Multiple Attribute Decision Making Based Relay Vehicle Selection for Electric Vehicle Communication

Directory of Open Access Journals (Sweden)

Zhao Qiang

2015-01-01

Full Text Available Large-scale electric vehicle integration into power grid and charging randomly will cause serious impacts on the normal operation of power grid. Therefore, it is necessary to control the charging behavior of electric vehicle, while information transmission for electric vehicle is significant. Due to the highly mobile characteristics of vehicle, transferring information to power grid directly might be inaccessible. Relay vehicle (RV can be used for supporting multi-hop connection between SV and power grid. This paper proposes a multiple attribute decision making (MADM-based RV selection algorithm, which considers multiple attribute, including data transfer rate, delay, route duration. It takes the characteristics of electric vehicle communication into account, which can provide protection for the communication services of electric vehicle charging and discharging. Numerical results demonstrate that compared to previous algorithm, the proposed algorithm offer better performance in terms of throughput, transmission delay.

Highly Flexible and Efficient Fabric-Based Organic Light-Emitting Devices for Clothing-Shaped Wearable Displays.

Science.gov (United States)

Choi, Seungyeop; Kwon, Seonil; Kim, Hyuncheol; Kim, Woohyun; Kwon, Jung Hyun; Lim, Myung Sub; Lee, Ho Seung; Choi, Kyung Cheol

2017-07-25

Recently, the role of clothing has evolved from merely body protection, maintaining the body temperature, and fashion, to advanced functions such as various types of information delivery, communication, and even augmented reality. With a wireless internet connection, the integration of circuits and sensors, and a portable power supply, clothes become a novel electronic device. Currently, the information display is the most intuitive interface using visualized communication methods and the simultaneous concurrent processing of inputs and outputs between a wearer and functional clothes. The important aspect in this case is to maintain the characteristic softness of the fabrics even when electronic devices are added to the flexible clothes. Silicone-based light-emitting diode (LED) jackets, shirts, and stage costumes have started to appear, but the intrinsic stiffness of inorganic semiconductors causes wearers to feel discomfort; thus, it is difficult to use such devices for everyday purposes. To address this problem, a method of fabricating a thin and flexible emitting fabric utilizing organic light-emitting diodes (OLEDs) was developed in this work. Its flexibility was evaluated, and an analysis of its mechanical bending characteristics and tests of its long-term reliability were carried out.

Organic light-emitting diodes based on 9-(2-naphthyl)anthracene derivatives with a triphenylsilane unit as the deep-blue emitting layer

Energy Technology Data Exchange (ETDEWEB)

Song, Ji Young; Lee, Seul Bee [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, Seok Jae [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Kim, Young Kwan, E-mail: kimyk@wow.hongik.ac.kr [Department of Information Display, Hongik University, Seoul 121-791 (Korea, Republic of); Yoon, Seung Soo, E-mail: ssyoon@skku.edu [Department of Chemistry, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2015-02-27

A series of 9-(2-naphthyl)anthracene derivatives with a triphenylsilane unit, which prevented molecular aggregation and self-quenching effect, was designed and synthesized. By using various bridges between the 9-(2-naphthyl)anthracene group and the triphenylsilane unit, five deep-blue emitters were obtained and applied as non-doped emitting materials in organic light-emitting diodes (OLEDs) with a device structure of indium–tin-oxide (ITO) (180 nm)/4,4-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (NPB) (50 nm)/emitting materials (30 nm)/4,7-diphenyl-1,10-phenanthroline (Bphen) (30 nm)/lithium quinolate (Liq) (2 nm)/Aluminium (100 nm). All devices showed blue emissions and their electroluminescence efficiencies are sensitive to the structural changes of the emitting materials. In particular, a device using 9-(2-naphthalenyl)-10-[6-(triphenylsilyl)-2-naphthalenyl]-anthracene (4) exhibited high luminous, power and quantum efficiencies of 2.28 cd/A, 1.42 lm/W and 2.40% at 20 mA/cm{sup 2}, respectively, and this device showed the deep blue emission with the CIE coordinates of (0.16, 0.10) at 6.0 V. - Highlights: • We synthesized 9-(2-naphthyl)anthracene derivatives with a triphenylsilane unit. • We study the conjugation-length effect on the electroluminescence properties. • The bulky triphenylsilane-anthracene derivatives show resistance to self-aggregation.

Optimal Operation of Plug-In Electric Vehicles in Power Systems with High Wind Power Penetrations

DEFF Research Database (Denmark)

Hu, Weihao; Su, Chi; Chen, Zhe

2013-01-01

in the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost for PEV......The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations...... owners. Furthermore, the application of battery storage based aggregated PEV is analyzed as a regulation services provider in the power system with high wind power penetrations. The western Danish power system where the total share of annual wind power production is more than 27% of the electrical energy...

Metasurface integrated high energy efficient and high linearly polarized InGaN/GaN light emitting diode.

Science.gov (United States)

Wang, Miao; Xu, Fuyang; Lin, Yu; Cao, Bing; Chen, Linghua; Wang, Chinhua; Wang, Jianfeng; Xu, Ke

2017-07-06

We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface. This significantly enhances the polarized light emission efficiency. Experimental results show that extraction efficiency of the polarized emission can be increased by 40% on average in a wide angle of ±60° compared to that with the naked bottom of sapphire substrate, or 20% compared to reflecting Al film on the bottom of a sapphire substrate. An extinction ratio (ER) of average value 20 dB within an angle of ±60° can be simultaneously obtained directly from an InGaN/GaN LED. Our results show the possibility of simultaneously achieving a high degree of polarization and high polarization extraction efficiency at the integrated device level. This advances the field of GaN LED toward energy efficiency, multi-functional applications in illumination, display, medicine, and light manipulation.

PLUG-IN HYBRID ELECTRIC VEHICLE AND HYBRID ELECTRIC VEHICLE EMISSIONS UNDER FTP AND US06 CYCLES AT HIGH, AMBIENT, AND LOW TEMPERATURES

Energy Technology Data Exchange (ETDEWEB)

Seidman, M.R.; Markel, T.

2008-01-01

The concept of a Plug-in Hybrid Electric Vehicle (PHEV) is to displace consumption of gasoline by using electricity from the vehicle’s large battery pack to power the vehicle as much as possible with minimal engine operation. This paper assesses the PHEV emissions and operation. Currently, testing of vehicle emissions is done using the federal standard FTP4 cycle on a dynamometer at ambient (75°F) temperatures. Research was also completed using the US06 cycle. Furthermore, research was completed at high (95°F) and low (20°F) temperatures. Initial dynamometer testing was performed on a stock Toyota Prius under the standard FTP4 cycle, and the more demanding US06 cycle. Each cycle was run at 95°F, 75°F, and 20°F. The testing was repeated with the same Prius retrofi tted with an EnergyCS Plug-in Hybrid Electric system. The results of the testing confi rm that the stock Prius meets Super-Ultra Low Emission Vehicle requirements under current testing procedures, while the PHEV Prius under current testing procedures were greater than Super-Ultra Low Emission Vehicle requirements, but still met Ultra Low Emission Vehicle requirements. Research points to the catalyst temperature being a critical factor in meeting emission requirements. Initial engine emissions pass through with minimal conversion until the catalyst is heated to typical operating temperatures of 300–400°C. PHEVs also have trouble maintaining the minimum catalyst temperature throughout the entire test because the engine is turned off when the battery can support the load. It has been observed in both HEVs and PHEVs that the catalyst is intermittently unable to reduce nitrogen oxide emissions, which causes further emission releases. Research needs to be done to combat the initial emission spikes caused by a cold catalyst. Research also needs to be done to improve the reduction of nitrogen oxides by the catalyst system.

Imaging instrument for positron emitting heavy ion beam injection

International Nuclear Information System (INIS)

Llacer, J.; Chatterjee, A.; Jackson, H.C.; Lin, J.C.; Zunzunegui, M.V.

1978-10-01

The design and performance of an instrument for the imaging of coincidence annihilation gamma rays emitted from the end point of the trajectories of radioactive high-energy heavy ions is described. The positron-emitting heavy ions are the result of nuclear fragmentation of accelerated heavy ions used in cancer therapy or diagnostic medicine. The instrument constructed is capable of locating the ion beam trajectory end point within 1 mm for an injected activity of 200 nanoCi in a measurement time of 1 sec in some favorable conditions. Limited imaging in three dimensions is also demonstrated

High performance multilayered nano-crystalline silicon/silicon-oxide light-emitting diodes on glass substrates

Energy Technology Data Exchange (ETDEWEB)

Darbari, S; Shahmohammadi, M; Mortazavi, M; Mohajerzadeh, S [Thin Film and Nano-Electronic Laboratory, School of ECE, University of Tehran, Tehran (Iran, Islamic Republic of); Abdi, Y [Nano-Physics Research Laboratory, Department of Physics, University of Tehran, Tehran (Iran, Islamic Republic of); Robertson, M; Morrison, T, E-mail: mohajer@ut.ac.ir [Department of Physics, Acadia University, Wolfville, NS (Canada)

2011-09-16

A low-temperature hydrogenation-assisted sequential deposition and crystallization technique is reported for the preparation of nano-scale silicon quantum dots suitable for light-emitting applications. Radio-frequency plasma-enhanced deposition was used to realize multiple layers of nano-crystalline silicon while reactive ion etching was employed to create nano-scale features. The physical characteristics of the films prepared using different plasma conditions were investigated using scanning electron microscopy, transmission electron microscopy, room temperature photoluminescence and infrared spectroscopy. The formation of multilayered structures improved the photon-emission properties as observed by photoluminescence and a thin layer of silicon oxy-nitride was then used for electrical isolation between adjacent silicon layers. The preparation of light-emitting diodes directly on glass substrates has been demonstrated and the electroluminescence spectrum has been measured.

A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2018-06-01

This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

Understanding the emission impacts of high-occupancy vehicle (HOV) to high-occupancy toll (HOT) lane conversions: Experience from Atlanta, Georgia.

Science.gov (United States)

Xu, Yanzhi Ann; Liu, Haobing; Rodgers, Michael O; Guin, Angshuman; Hunter, Michael; Sheikh, Adnan; Guensler, Randall

2017-08-01

Converting a congested high-occupancy vehicle (HOV) lane into a high-occupancy toll (HOT) lane is a viable option for improving travel time reliability for carpools and buses that use the managed lane. However, the emission impacts of HOV-to-HOT conversions are not well understood. The lack of emission impact quantification for HOT conversions creates a policy challenge for agencies making transportation funding choices. The goal of this paper is to evaluate the case study of before-and-after changes in vehicle emissions for the Atlanta, Georgia, I-85 HOV/HOT lane conversion project, implemented in October 2011. The analyses employed the Motor Vehicle Emission Simulator (MOVES) for project-level analysis with monitored changes in vehicle activity data collected by Georgia Tech researchers for the Georgia Department of Transportation (GDOT). During the quarterly field data collection from 2010 to 2012, more than 1.5 million license plates were observed and matched to vehicle class and age information using the vehicle registration database. The study also utilized the 20-sec, lane-specific traffic operations data from the Georgia NaviGAtor intelligent transportation system, as well as a direct feed of HOT lane usage data from the State Road and Tollway Authority (SRTA) managed lane system. As such, the analyses in this paper simultaneously assessed the impacts associated with changes in traffic volumes, on-road operating conditions, and fleet composition before and after the conversion. Both greenhouse gases and criteria pollutants were examined. A straight before-after analysis showed about 5% decrease in air pollutants and carbon dioxide (CO 2 ). However, when the before-after calendar year of analysis was held constant (to account for the effect of 1 yr of fleet turnover), mass emissions at the analysis site during peak hours increased by as much as 17%, with little change in CO 2 . Further investigation revealed that a large percentage decrease in criteria

Hydraulic Hybrid Fleet Vehicle Testing | Transportation Research | NREL

Science.gov (United States)

Hydraulic Hybrid Fleet Vehicle Evaluations Hydraulic Hybrid Fleet Vehicle Evaluations How Hydraulic Hybrid Vehicles Work Hydraulic hybrid systems can capture up to 70% of the kinetic energy that would -pressure reservoir to a high-pressure accumulator. When the vehicle accelerates, fluid in the high-pressure

Fluorescence lifetime imaging using light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Kennedy, Gordon T; Munro, Ian; Poher, Vincent; French, Paul M W; Neil, Mark A A [Blackett Laboratory, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Elson, Daniel S [Institute of Biomedical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Hares, Jonathan D [Kentech Instruments Ltd, Unit 9, Hall Farm Workshops, South Moreton, Didcot, Oxfordshire, OX11 9AG (United Kingdom)], E-mail: gordon.kennedy@imperial.ac.uk

2008-05-07

We demonstrate flexible use of low cost, high-power light emitting diodes as illumination sources for fluorescence lifetime imaging (FLIM). Both time-domain and frequency-domain techniques have been implemented at wavelengths spanning the range 450-640 nm. Additionally, we demonstrate optically sectioned fluorescence lifetime imaging by combining structured illumination with frequency-domain FLIM.

Preface to the special section on human factors and automation in vehicles: designing highly automated vehicles with the driver in mind.

Science.gov (United States)

Merat, Natasha; Lee, John D

2012-10-01

This special section brings together diverse research regarding driver interaction with advanced automotive technology to guide design of increasingly automated vehicles. Rapidly evolving vehicle automation will likely change cars and trucks more in the next 5 years than the preceding 50, radically redefining what it means to drive. This special section includes 10 articles from European and North American researchers reporting simulator and naturalistic driving studies. Little research has considered the consequences of fully automated driving, with most focusing on lane-keeping and speed control systems individually. The studies reveal two underlying design philosophies: automate driving versus support driving. Results of several studies, consistent with previous research in other domains, suggest that the automate philosophy can delay driver responses to incidents in which the driver has to intervene and take control from the automation. Understanding how to orchestrate the transfer or sharing of control between the system and the driver, particularly in critical incidents, emerges as a central challenge. Designers should not assume that automation can substitute seamlessly for a human driver, nor can they assume that the driver can safely accommodate the limitations of automation. Designers, policy makers, and researchers must give careful consideration to what role the person should have in highly automated vehicles and how to support the driver if the driver is to be responsible for vehicle control. As in other domains, driving safety increasingly depends on the combined performance of the human and automation, and successful designs will depend on recognizing and supporting the new roles of the driver.

Implementation elements for conversion of general-purpose freeway lane into high-occupancy-vehicle lane

Science.gov (United States)

1997-01-01

Conversion of a general-purpose freeway into a high-occupancy-vehicle (HOV) lane is an alternative to infrastructure addition for HOV system implementation. Research indicates that lane conversion is feasible technically if sufficient HOV usage and m...

Sensing and control for autonomous vehicles applications to land, water and air vehicles

CERN Document Server

Pettersen, Kristin; Nijmeijer, Henk

2017-01-01

This edited volume includes thoroughly collected on sensing and control for autonomous vehicles. Guidance, navigation and motion control systems for autonomous vehicles are increasingly important in land-based, marine and aerial operations. Autonomous underwater vehicles may be used for pipeline inspection, light intervention work, underwater survey and collection of oceanographic/biological data. Autonomous unmanned aerial systems can be used in a large number of applications such as inspection, monitoring, data collection, surveillance, etc. At present, vehicles operate with limited autonomy and a minimum of intelligence. There is a growing interest for cooperative and coordinated multi-vehicle systems, real-time re-planning, robust autonomous navigation systems and robust autonomous control of vehicles. Unmanned vehicles with high levels of autonomy may be used for safe and efficient collection of environmental data, for assimilation of climate and environmental models and to complement global satellite sy...

Emissions of CO2, CO, NOx, HC, PM, HFC-134a, N2O and CH4 from the global light duty vehicle fleet

Directory of Open Access Journals (Sweden)

Timothy J. Wallington

2008-04-01

Full Text Available Vehicles emit carbon dioxide (CO2, carbon monoxide (CO, nitrogen oxides (NOx, hydrocarbons (HC, particulate matter (PM, hydrofluorocarbon 134a (HFC-134a, methane (CH4, and nitrous oxide (N2O. An understanding of these emissions is needed in discussions of climate change and local air pollution issues. To facilitate such discussions an overview of past, present, and likely future emissions from light duty vehicles is presented. Emission control technologies have reduced the emissions of CO, VOCs, PM, HFC-134a, CH4, and N2O from modern vehicles to very low levels.

Si light-emitting device in integrated photonic CMOS ICs

Science.gov (United States)

Xu, Kaikai; Snyman, Lukas W.; Aharoni, Herzl

2017-07-01

The motivation for integrated Si optoelectronics is the creation of low-cost photonics for mass-market applications. Especially, the growing demand for sensitive biochemical sensors in the environmental control or medicine leads to the development of integrated high resolution sensors. Here CMOS-compatible Si light-emitting device structures are presented for investigating the effect of various depletion layer profiles and defect engineering on the photonic transition in the 1.4-2.8 eV. A novel Si device is proposed to realize both a two-terminal Si-diode light-emitting device and a three-terminal Si gate-controlled diode light-emitting device in the same device structure. In addition to the spectral analysis, differences between two-terminal and three-terminal devices are discussed, showing the light emission efficiency change. The proposed Si optical source may find potential applications in micro-photonic systems and micro-optoelectro-mechanical systems (MOEMS) in CMOS integrated circuitry.

Droop-Free, Reliable, and High-Power InGaN/GaN Nanowire Light-Emitting Diodes for Monolithic Metal-Optoelectronics

KAUST Repository

Zhao, Chao

2016-07-28

A droop-free nitride light-emitting diode (LED) with the capacity to operate beyond the “green gap” has been a subject of intense scientific and engineering interest. While several properties of nanowires on silicon make them promising for use in LED development, the high aspect ratio of individual nanowires and their laterally discontinuous features limit phonon transport and device performance. Here, we report on the monolithic integration of metal heat-sink and droop-free InGaN/GaN quantum-disks-in-nanowire LEDs emitting at ∼710 nm. The reliable operation of our uncooled nanowire-LEDs (NW-LEDs) epitaxially grown on molybdenum was evident in the constant-current soft burn-in performed on a 380 μm × 380 μm LED. The square LED sustained 600 mA electrical stress over an 8 h period, providing stable light output at maturity without catastrophic failure. The absence of carrier and phonon transport barriers in NW-LEDs was further inferred from current-dependent Raman measurements (up to 700 mA), which revealed the low self-heating. The radiative recombination rates of NW-LEDs between room temperature and 40 °C was not limited by Shockley–Read–Hall recombination, Auger recombination, or carrier leakage mechanisms, thus realizing droop-free operation. The discovery of reliable, droop-free devices constitutes significant progress toward the development of nanowires for practical applications. Our monolithic approach realized a high-performance device that will revolutionize the way high power, low-junction-temperature LED lamps are manufactured for solid-state lighting and for applications in high-temperature harsh environment.

Enhanced quantum efficiency in blue-emitting polymer/dielectric nanolayer nanocomposite light-emitting devices

International Nuclear Information System (INIS)

Park, Jong Hyeok; Lim, Yong Taik; Park, O Ok; Yu, Jae-Woong; Kim, Jai Kyeong; Kim, Young Chul

2004-01-01

Light-emitting devices based on environmentally stable, blue-emitting polymer/dielectric nanolayer nanocomposites were fabricated by blending poly(di-octylfluorene) (PDOF) with organo-clay. By reducing the excimer formation that leads to long wavelength tails, the photoluminescence (PL) and electroluminescence (EL) color purity of the device was enhanced. When a conjugated polymer/dielectric nanolayer nanocomposite is applied to an EL device, we expect an electronic structure similar to the well-known quantum well in small nanodomains. The ratio of PDOF/organo-clay was regulated from 2:1 to 0.5:1 (w/w). The light-emitting device of 0.5:1 (w/w) blend demonstrated the highest quantum efficiency (QE), 0.72% (ph/el), which is ∼500 times higher value compared with that of the pure PDOF layer device. However, the driving voltage of the nanocomposite devices tended to increase with increasing organo-clay content

Analysis of x-ray spectra emitted from highly ionized atoms in the vacuum spark and laser-produced high power plasma sources

International Nuclear Information System (INIS)

Mandelbaum, P.

1987-05-01

The interest in atomic spectroscopy has greatly been reinforced in the last ten years. This gain of interest is directly related to the developments in different fields of research where hot plasmas are created. These fields include in particular controlled thermonuclear fusion research by means of inertial or magnetic confinement approaches and also the most recent efforts to achieve lasers in the XUV region. The present work is based on the specific contribution of the atomic spectroscopy group at the Hebrew University. The recent development of both theoretical and experimental tools allowed us to progress in the understanding of the highly ionized states of heavy elements. In this work the low-inductance vacuum-spark developed at the Hebrew University was used as the hot plasma source. The spectra were recorded in the 7-300 A range by means of a high-resolution extreme-grazing-incidence spectrometer developed at the Racah Institute by Profs. J.L. Schwob and B.S. Fraenkel. To the extend the spectroscopic studies to higher-Z atoms, the laser-produced plasma facility at Soreq Nuclear Center was used. In this work the spectra of the sixth row elements were recorded in the x-rays by means of a crystal spectrometer. All these experimental systems are briefly described in chapter one. Chapter two deals with the theoretical methods used in the present work for the atomic calculations. Chapter three deals with the spectra of elements of the fifth row emitted from the vacuum-spark in the 30-150 A range. These spectra as experimental data were used in order to test ab-initio computations along the NiI sequence 3d-nl transitions. The results of this work are presented in chapter four. Chapter five is devoted to the measurement and analysis of spectra emitted from the vacuum-spark by rare-earth elements. (author)

Hybrid Power Management-Based Vehicle Architecture

Science.gov (United States)

Eichenberg, Dennis J.

2011-01-01

Hybrid Power Management (HPM) is the integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications (s ee figure). The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The basic vehicle architecture consists of a primary power source, and possibly other power sources, that provides all power to a common energy storage system that is used to power the drive motors and vehicle accessory systems. This architecture also provides power as an emergency power system. Each component is independent, permitting it to be optimized for its intended purpose. The key element of HPM is the energy storage system. All generated power is sent to the energy storage system, and all loads derive their power from that system. This can significantly reduce the power requirement of the primary power source, while increasing the vehicle reliability. Ultracapacitors are ideal for an HPM-based energy storage system due to their exceptionally long cycle life, high reliability, high efficiency, high power density, and excellent low-temperature performance. Multiple power sources and multiple loads are easily incorporated into an HPM-based vehicle. A gas turbine is a good primary power source because of its high efficiency, high power density, long life, high reliability, and ability to operate on a wide range of fuels. An HPM controller maintains optimal control over each vehicle component. This flexible operating system can be applied to all vehicles to considerably improve vehicle efficiency, reliability, safety, security, and performance. The HPM-based vehicle architecture has many advantages over conventional vehicle architectures. Ultracapacitors have a much longer cycle life than batteries, which greatly improves system reliability, reduces life-of-system costs, and reduces environmental impact as ultracapacitors will probably never need to be

Trajectory Optimization and Conceptual Study of Small Test Vehicles for a Hypersonic Engine Using a High-Altitude Balloon

Science.gov (United States)

Tsuchiya, Takeshi; Takenaka, Youichi; Taguchi, Hideyuki; Sawai, Shujiro

The Japan Aerospace Exploration Agency, JAXA, announced a long-term vision recently. In the vision, JAXA aims to develop hypersonic aircrafts. A pre-cooled turbojet engine has great potential as one of newly developed hypersonic airbreathing engines. We also expect the engine to be installed in space transportation vehicles in the future. For combustion test in the real flight conditions of the engines, JAXA has an experimental plan where a small test vehicle is released from a high-altitude balloon. This paper applies numerical analysis and optimization techniques to conceptual designs of the test vehicle in order to obtain the best configuration and trajectory for the flight test. The results show helpful knowledge for designing prototype vehicles.

On-board measurements of gaseous pollutant emission characteristics under real driving conditions from light-duty diesel vehicles in Chinese cities.

Science.gov (United States)

Wang, Gang; Cheng, Shuiyuan; Lang, Jianlei; Li, Song; Tian, Liang

2016-08-01

A total of 15 light-duty diesel vehicles (LDDVs) were tested with the goal of understanding the emission factors of real-world vehicles by conducting on-board emission measurements. The emission characteristics of hydrocarbons (HC) and nitrogen oxides (NOx) at different speeds, chemical species profiles and ozone formation potential (OFP) of volatile organic compounds (VOCs) emitted from diesel vehicles with different emission standards were analyzed. The results demonstrated that emission reductions of HC and NOx had been achieved as the control technology became more rigorous from Stage I to Stage IV. It was also found that the HC and NOx emissions and percentage of O2 dropped with the increase of speed, while the percentage of CO2 increased. The abundance of alkanes was significantly higher in diesel vehicle emissions, approximately accounting for 41.1%-45.2%, followed by aromatics and alkenes. The most abundant species were propene, ethane, n-decane, n-undecane, and n-dodecane. The maximum incremental reactivity (MIR) method was adopted to evaluate the contributions of individual VOCs to OFP. The results indicated that the largest contributors to O3 production were alkenes and aromatics, which accounted for 87.7%-91.5%. Propene, ethene, 1,2,4-trimethylbenzene, 1-butene, and 1,2,3-trimethylbenzene were the top five VOC species based on their OFP, and accounted for 54.0%-64.8% of the total OFP. The threshold dilution factor was applied to analyze the possibility of VOC stench pollution. The majority of stench components emitted from vehicle exhaust were aromatics, especially p-diethylbenzene, propylbenzene, m-ethyltoluene, and p-ethyltoluene. Copyright © 2016. Published by Elsevier B.V.

Vertical-cavity surface-emitting lasers for medical diagnosis

DEFF Research Database (Denmark)

Ansbæk, Thor

This thesis deals with the design and fabrication of tunable Vertical-Cavity Surface-Emitting Lasers (VCSELs). The focus has been the application of tunable VCSELs in medical diagnostics, specifically OCT. VCSELs are candidates as light sources for swept-source OCT where their high sweep rate, wide...

Followup Audit: DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle

Science.gov (United States)

2016-04-29

Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled Vehicle A P R I L...Results in Brief Followup Audit : DLA Officials Took Appropriate Actions to Address Concerns With Repair Parts for the High Mobility Multipurpose Wheeled...and Maritime Paid Too Much for High Mobility Multipurpose Wheeled Vehicle Repair Parts,” (HMMWV) was issued on April 4, 2014. The audit

The use of ionic salt dyes as amorphous, thermally stable emitting layers in organic light-emitting diodes

Science.gov (United States)

Chondroudis, Konstantinos; Mitzi, David B.

2000-01-01

The conversion of two neutral dye molecules (D) to ionic salts (H2N-D-NH2ṡ2HX) and their utilization as emitting layers in organic light-emitting diodes (OLEDs) is described. The dye salts, AEQTṡ2HCl and APTṡ2HCl, can be deposited as amorphous films using conventional evaporation techniques. X-ray diffraction and scanning electron microscopy analysis, coupled with thermal annealing studies, demonstrate the resistance of the films to crystallization. This stability is attributed to strong ionic forces between the relatively rigid molecules. OLEDs incorporating such salts for emitting layers exhibit better thermal stability compared with devices made from the corresponding neutral dyes (H2N-D-NH2). These results suggest that ionic salts may more generally enable the formation of thermally stable, amorphous emitting, and charge transporting layers.

FY 1999 report on the investigational study of the actual state of the utilization of clean energy vehicles for the transport business use; 1999 nendo chosa hokokusho. Unso jigyo yo clean energy jidosha no shiyo jittai ni kakawaru chosa kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of promoting the utilization of clean energy vehicles (CEV), survey was made on the assessment of the pollution by the CEVs introduced by now, subjects on the utilization, etc. As to the transport business use CEV running in the market, CNG vehicle is mostly used, and therefore, the gas emitted from them was tested. As a result, it was found out that CNG vehicle emits fewer NOx, PM and soot/smoke than diesel cars and contributes to improving the air pollution in large cities. However, it emits more CO2 than diesel car, and accordingly, it is necessary to reduce the fuel consumption. The practicality in the limited running distance is almost the same as that of diesel car, but it is desirable to improve startability, acceleration and gradability. Further, the occurrence of any troubles was pointed out in a third of the total numbers of CEV vehicle. Improvement in reliability is a must. CEV is higher in car cost than diesel car, and for the spread/promotion, it is necessary to prepare for assistance such as subsidy. Moreover, there are many requests for improvement in number, business hours, supply capacity, etc. of fuel supply station. (NEDO)

VCSELs Fundamentals, Technology and Applications of Vertical-Cavity Surface-Emitting Lasers

CERN Document Server

2013-01-01

The huge progress which has been achieved in the field is covered here, in the first comprehensive monograph on vertical-cavity surface-emitting lasers (VCSELs) since eight years. Apart from chapters reviewing the research field and the laser fundamentals, there are comprehensive updates on red and blue emitting VCSELs, telecommunication VCSELs, optical transceivers, and parallel-optical links for computer interconnects. Entirely new contributions are made to the fields of vectorial three-dimensional optical modeling, single-mode VCSELs, polarization control, polarization dynamics, very-high-speed design, high-power emission, use of high-contrast gratings, GaInNAsSb long-wavelength VCSELs, optical video links, VCSELs for optical mice and sensing, as well as VCSEL-based laser printing. The book appeals to researchers, optical engineers and graduate students.

High-power, format-flexible, 885-nm vertical-cavity surface-emitting laser arrays

Science.gov (United States)

Wang, Chad; Talantov, Fedor; Garrett, Henry; Berdin, Glen; Cardellino, Terri; Millenheft, David; Geske, Jonathan

2013-03-01

High-power, format flexible, 885 nm vertical-cavity surface-emitting laser (VCSEL) arrays have been developed for solid-state pumping and illumination applications. In this approach, a common VCSEL size format was designed to enable tiling into flexible formats and operating configurations. The fabrication of a common chip size on ceramic submount enables low-cost volume manufacturing of high-power VCSEL arrays. This base VCSEL chip was designed to be 5x3.33 mm2, and produced up to 50 Watts of peak continuous wave (CW) power. To scale to higher powers, multiple chips can be tiled into a combination of series or parallel configurations tailored to the application driver conditions. In actively cooled CW operation, the VCSEL array chips were packaged onto a single water channel cooler, and we have demonstrated 0.5x1, 1x1, and 1x3 cm2 formats, producing 150, 250, and 500 Watts of peak power, respectively, in under 130 A operating current. In QCW operation, the 1x3 cm2 VCSEL module, which contains 18 VCSEL array chips packaged on a single water cooler, produced over 1.3 kW of peak power. In passively cooled packages, multiple chip configurations have been developed for illumination applications, producing over 300 Watts of peak power in QCW operating conditions. These VCSEL chips use a substrate-removed structure to allow for efficient thermal heatsinking to enable high-power operation. This scalable, format flexible VCSEL architecture can be applied to wavelengths ranging from 800 to 1100 nm, and can be used to tailor emission spectral widths and build high-power hyperspectral sources.

Intelligent behaviors through vehicle-to-vehicle and vehicle-to-infrastructure communication

Science.gov (United States)

Garcia, Richard D.; Sturgeon, Purser; Brown, Mike

2012-06-01

The last decade has seen a significant increase in intelligent safety devices on private automobiles. These devices have both increased and augmented the situational awareness of the driver and in some cases provided automated vehicle responses. To date almost all intelligent safety devices have relied on data directly perceived by the vehicle. This constraint has a direct impact on the types of solutions available to the vehicle. In an effort to improve the safety options available to a vehicle, numerous research laboratories and government agencies are investing time and resources into connecting vehicles to each other and to infrastructure-based devices. This work details several efforts in both the commercial vehicle and the private auto industries to increase vehicle safety and driver situational awareness through vehicle-to-vehicle and vehicle-to-infrastructure communication. It will specifically discuss intelligent behaviors being designed to automatically disable non-compliant vehicles, warn tractor trailer vehicles of unsafe lane maneuvers such as lane changes, passing, and merging, and alert drivers to non-line-of-sight emergencies.

Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

Science.gov (United States)

Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

2005-06-01

For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

Study on high reliability safety valve for railway vehicle

Science.gov (United States)

Zhang, Xuan; Chen, Ruikun; Zhang, Shixi; Xu, BuDu

2017-09-01

Now, the realization of most of the functions of the railway vehicles rely on compressed air, so the demand for compressed air is growing higher and higher. This safety valve is a protection device for pressure limitation and pressure relief in an air supply system of railway vehicles. I am going to introduce the structure, operating principle, research and development process of the safety valve designed by our company in this document.

Tandem white organic light-emitting diodes adopting a C60:rubrene charge generation layer

International Nuclear Information System (INIS)

Bi Wen-Tao; Wu Xiao-Ming; Hua Yu-Lin; Sun Jin-E; Xiao Zhi-Hui; Wang Li; Yin Shou-Gen

2014-01-01

Organic bulk heterojunction fullerence (C 60 ) doped 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) as the high quality charge generation layer (CGL) with high transparency and superior charge generating capability for tandem organic light emitting diodes (OLEDs) is developed. This CGL shows excellent optical transparency about 90%, which can reduce the optical interference effect formed in tandem OLEDs. There is a stable white light emission including 468 nm and 500 nm peaks from the blue emitting layer and 620 nm peak from the red emitting layer in tandem white OLEDs. A high efficiency of about 17.4 cd/A and CIE coordinates of (0.40, 0.35) at 100 cd/m 2 and (0.36, 0.34) at 1000 cd/m 2 have been demonstrated by employing the developed CGL, respectively. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Harvesting Triplet Excitons with Exciplex Thermally Activated Delayed Fluorescence Emitters toward High Performance Heterostructured Organic Light-Emitting Field Effect Transistors.

Science.gov (United States)

Song, Li; Hu, Yongsheng; Liu, Zheqin; Lv, Ying; Guo, Xiaoyang; Liu, Xingyuan

2017-01-25

The utilization of triplet excitons plays a key role in obtaining high emission efficiency for organic electroluminescent devices. However, to date, only phosphorescent materials have been implemented to harvest the triplet excitons in the organic light-emitting field effect transistors (OLEFETs). In this work, we report the first incorporation of exciplex thermally activated delayed fluorescence (TADF) emitters in heterostructured OLEFETs to harvest the triplet excitons. By developing a new kind of exciplex TADF emitter constituted by m-MTDATA (4,4',4″-tris(N-3-methylphenyl-N-phenylamino)triphenylamine) as the donor and OXD-7 (1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene) as the acceptor, an exciton utilization efficiency of 74.3% for the devices was achieved. It is found that the injection barrier between hole transport layer and emission layer as well as the ratio between donor and acceptor would influence the external quantum efficiency (EQE) significantly. Devices with a maximum EQE of 3.76% which is far exceeding the reported results for devices with conventional fluorescent emitters were successfully demonstrated. Moreover, the EQE at high brightness even outperformed the result for organic light-emitting diode based on the same emitter. Our results demonstrate that the exciplex TADF emitters can be promising candidates to develop OLEFETs with high performance.

High-power AlGaN-based near-ultraviolet light-emitting diodes grown on Si(111)

Science.gov (United States)

Li, Zengcheng; Liu, Legong; Huang, Yingnan; Sun, Qian; Feng, Meixin; Zhou, Yu; Zhao, Hanmin; Yang, Hui

2017-07-01

High-power AlGaN-based 385 nm near-ultraviolet light-emitting diodes (UVA-LEDs) grown on Si(111) substrates are reported. The threading dislocation (TD) density of AlGaN was reduced by employing an Al-composition step-graded AlN/AlGaN multilayer buffer. V-shaped pits were intentionally incorporated into the active region to screen the carriers from the nonradiative recombination centers (NRCs) around the TDs and to facilitate hole injection. The light extraction efficiency was enhanced by the surface roughening of a thin-film (TF) vertical chip structure. The as-fabricated TF-UVA-LED exhibited a light output power of 960 mW at 500 mA, corresponding to an external quantum efficiency of 59.7%.

Real-Time Vehicle Speed Estimation Based on License Plate Tracking in Monocular Video Sequences

Directory of Open Access Journals (Sweden)

Aleksej MAKAROV

2016-02-01

Full Text Available A method of estimating the vehicle speed from images obtained by a fixed over-the-road monocular camera is presented. The method is based on detecting and tracking vehicle license plates. The contrast between the license plate and its surroundings is enhanced using infrared light emitting diodes and infrared camera filters. A range of the license plate height values is assumed a priori. The camera vertical angle of view is measured prior to installation. The camera tilt is continuously measured by a micro-electromechanical sensor. The distance of the license plate from the camera is theoretically derived in terms of its pixel coordinates. Inaccuracies due to the frame rate drift, to the tilt and the angle of view measurement errors, to edge pixel detection and to a coarse assumption of the vehicle license plate height are analyzed and theoretically formulated. The resulting system is computationally efficient, inexpensive and easy to install and maintain along with the existing ALPR cameras.

Takeover Time in Highly Automated Vehicles: Noncritical Transitions to and From Manual Control.

Science.gov (United States)

Eriksson, Alexander; Stanton, Neville A

2017-06-01

The aim of this study was to review existing research into driver control transitions and to determine the time it takes drivers to resume control from a highly automated vehicle in noncritical scenarios. Contemporary research has moved from an inclusive design approach to adhering only to mean/median values when designing control transitions in automated driving. Research into control transitions in highly automated driving has focused on urgent scenarios where drivers are given a relatively short time span to respond to a request to resume manual control. We found a paucity in research into more frequent scenarios for control transitions, such as planned exits from highway systems. Twenty-six drivers drove two scenarios with an automated driving feature activated. Drivers were asked to read a newspaper, or to monitor the system, and to relinquish, or resume, control from the automation when prompted by vehicle systems. Significantly longer control transition times were found between driving with and without secondary tasks. Control transition times were substantially longer than those reported in the peer-reviewed literature. We found that drivers take longer to resume control when under no time pressure compared with that reported in the literature. Moreover, we found that drivers occupied by a secondary task exhibit larger variance and slower responses to requests to resume control. Workload scores implied optimal workload. Intra- and interindividual differences need to be accommodated by vehicle manufacturers and policy makers alike to ensure inclusive design of contemporary systems and safety during control transitions.

Determination of detailed regulations concerning transportation of radioactive materials by vehicles

International Nuclear Information System (INIS)

1978-01-01

These provisions are established on the basis of the ''Regulations concerning transportation of radioactive materials by vehicles''. The terms used hereinafter are according to those used in the Regulations. Radioactive materials include uranium 233, uranium 235, plutonium 238, plutonium 239, plutonium 241, the compounds of such materials and the substances containing one or two and more of such materials, excluding the radioactive materials with not more than 15 grams of such uranium and plutonium. The permissible surface density is 1/100,000 microcurie per cm 2 for radioactive materials emitting alpha-ray and 1/10,000 microcurie per cm 2 for such materials which does not emit alpha-ray. For the radioactive materials which can be transported as L type loads, their kinds and quantities are specified in the forms of solid, liquid and gas, respectively. Transporting conditions including the quantity and leakage in A, BM and BU type loads are provided for, respectively, in the lists attached and in the particular sections. (Okada, K.)

High-efficient, bicolor-emitting GdVO_4:Dy"3"+ phosphor under near ultraviolet excitation

International Nuclear Information System (INIS)

Lu, Jinjin; Zhou, Jia; Jia, Huayu; Tian, Yue

2015-01-01

Bicolor emitting GdVO_4:Dy"3"+ phosphor with short columniation-shape was prepared via a simple co-precipitation process. The optimal doping concentration for obtaining maximal luminescent intensity was confirmed to be 0.3 mol% and the electric dipole–dipole interaction is responsible for concentration quenching of Dy"3"+ emission in GdVO_4 phosphor. In order to evaluate the luminescent performance of as-prepared phosphor, the luminescent efficiency and color coordinates were studied. The results show that luminescent efficiency of this phosphor is very high under near UV excitation and twice times higher than commercial Y_2O_2S:Eu"3"+ phosphor. In addition, the color coordinates for optimal Dy"3"+ concentration are (0.339, 0.379), which are close to equal energy point. Therefore, the GdVO_4:Dy"3"+ phosphor may have potential application for solid state lighting.

Spectrum study of top-emitting organic light-emitting devices with micro-cavity structure

International Nuclear Information System (INIS)

Liu Xiang; Wei Fuxiang; Liu Hui

2009-01-01

Blue and white top-emitting organic light-emitting devices OLEDs with cavity effect have been fabricated. TBADN:3%DSAPh and Alq 3 :DCJTB/TBADN:TBPe/Alq 3 :C545 were used as emitting materials of microcavity OLEDs. On a patterned glass substrate, silver was deposited as reflective anode, and copper phthalocyanine (CuPc) layer as HIL and 4'-bis[N-(1-Naphthyl)- N-phenyl-amino]biphenyl (NPB) layer as HTL were made. Al/Ag thin films were made as semi-transparent cathode with a transmittance of about 30%. By changing the thickness of indium tin oxide ITO, deep blue with Commission Internationale de L'Eclairage chromaticity coordinates (CIEx, y) of (0.141, 0.049) was obtained on TBADN:3%DSAPh devices, and different color (red, blue and green) was obtained on Alq 3 :DCJTB/TBADN:TBPe/Alq 3 :C545 devices, full width at half maxima (FWHM) was only 17 nm. The spectral intensity and FWHM of emission in cavity devices have also been studied.

Side-suspended High- Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

International Nuclear Information System (INIS)

Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

2017-01-01

High- T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 10 3 Pa. (paper)

Side-suspended High-Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

Science.gov (United States)

Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

2017-07-01

High-T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 103 Pa.

Organic light emitting diodes with spin polarized electrodes

NARCIS (Netherlands)

Arisi, E.; Bergenti, I.; Dediu, V.; Loi, M.A.; Muccini, M.; Murgia, M.; Ruani, G.; Taliani, C.; Zamboni, R.

2003-01-01

Electrical and optical properties of Alq3 based organic light emitting diodes with normal and spin polarized electrodes are presented. Epitaxial semitransparent highly spin polarized La0.7Sr0.3MnO3 were used as hole injector, substituting the traditional indium tin oxide electrode. A comparison of

High-Brightness Blue Light-Emitting Diodes Enabled by a Directly Grown Graphene Buffer Layer.

Science.gov (United States)

Chen, Zhaolong; Zhang, Xiang; Dou, Zhipeng; Wei, Tongbo; Liu, Zhiqiang; Qi, Yue; Ci, Haina; Wang, Yunyu; Li, Yang; Chang, Hongliang; Yan, Jianchang; Yang, Shenyuan; Zhang, Yanfeng; Wang, Junxi; Gao, Peng; Li, Jinmin; Liu, Zhongfan

2018-06-08

Single-crystalline GaN-based light-emitting diodes (LEDs) with high efficiency and long lifetime are the most promising solid-state lighting source compared with conventional incandescent and fluorescent lamps. However, the lattice and thermal mismatch between GaN and sapphire substrate always induces high stress and high density of dislocations and thus degrades the performance of LEDs. Here, the growth of high-quality GaN with low stress and a low density of dislocations on graphene (Gr) buffered sapphire substrate is reported for high-brightness blue LEDs. Gr films are directly grown on sapphire substrate to avoid the tedious transfer process and GaN is grown by metal-organic chemical vapor deposition (MOCVD). The introduced Gr buffer layer greatly releases biaxial stress and reduces the density of dislocations in GaN film and In x Ga 1- x N/GaN multiple quantum well structures. The as-fabricated LED devices therefore deliver much higher light output power compared to that on a bare sapphire substrate, which even outperforms the mature process derived counterpart. The GaN growth on Gr buffered sapphire only requires one-step growth, which largely shortens the MOCVD growth time. This facile strategy may pave a new way for applications of Gr films and bring several disruptive technologies for epitaxial growth of GaN film and its applications in high-brightness LEDs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Light emitting device having peripheral emissive region

Science.gov (United States)

Forrest, Stephen R

2013-05-28

Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.

Integration of electric drive vehicles in the Danish electricity network with high wind power penetration

DEFF Research Database (Denmark)

Chandrashekhara, Divya K; Østergaard, Jacob; Larsen, Esben

2010-01-01

/conventional) which are likely to fuel these cars. The study was carried out considering the Danish electricity network state around 2025, when the EDV penetration levels would be significant enough to have an impact on the power system. Some of the interesting findings of this study are - EDV have the potential......This paper presents the results of a study carried out to examine the feasibility of integrating electric drive vehicles (EDV) in the Danish electricity network which is characterised by high wind power penetration. One of the main aims of this study was to examine the effect of electric drive...... vehicles on the Danish electricity network, wind power penetration and electricity market. In particular the study examined the effect of electric drive vehicles on the generation capacity constraints, load curve, cross border transmission capacity and the type of generating sources (renewable...

Basic Simulation Environment for Highly Customized Connected and Autonomous Vehicle Kinematic Scenarios.

Science.gov (United States)

Chai, Linguo; Cai, Baigen; ShangGuan, Wei; Wang, Jian; Wang, Huashen

2017-08-23

To enhance the reality of Connected and Autonomous Vehicles (CAVs) kinematic simulation scenarios and to guarantee the accuracy and reliability of the verification, a four-layer CAVs kinematic simulation framework, which is composed with road network layer, vehicle operating layer, uncertainties modelling layer and demonstrating layer, is proposed in this paper. Properties of the intersections are defined to describe the road network. A target position based vehicle position updating method is designed to simulate such vehicle behaviors as lane changing and turning. Vehicle kinematic models are implemented to maintain the status of the vehicles when they are moving towards the target position. Priorities for individual vehicle control are authorized for different layers. Operation mechanisms of CAVs uncertainties, which are defined as position error and communication delay in this paper, are implemented in the simulation to enhance the reality of the simulation. A simulation platform is developed based on the proposed methodology. A comparison of simulated and theoretical vehicle delay has been analyzed to prove the validity and the creditability of the platform. The scenario of rear-end collision avoidance is conducted to verify the uncertainties operating mechanisms, and a slot-based intersections (SIs) control strategy is realized and verified in the simulation platform to show the supports of the platform to CAVs kinematic simulation and verification.

Flexible bottom-emitting white organic light-emitting diodes with semitransparent Ni/Ag/Ni anode.

Science.gov (United States)

Koo, Ja-Ryong; Lee, Seok Jae; Lee, Ho Won; Lee, Dong Hyung; Yang, Hyung Jin; Kim, Woo Young; Kim, Young Kwan

2013-05-06

We fabricated a flexible bottom-emitting white organic light-emitting diode (BEWOLED) with a structure of PET/Ni/Ag/Ni (3/6/3 nm)/ NPB (50 nm)/mCP (10 nm)/7% FIrpic:mCP (10 nm)/3% Ir(pq)(2) acac:TPBi (5 nm)/7% FIrpic:TPBi (5 nm)/TPBi (10 nm)/Liq (2 nm)/ Al (100 nm). To improve the performance of the BEWOLED, a multilayered metal stack anode of Ni/Ag/Ni treated with oxygen plasma for 60 sec was introduced into the OLED devices. The Ni/Ag/Ni anode effectively enhanced the probability of hole-electron recombination due to an efficient hole injection into and charge balance in an emitting layer. By comparing with a reference WOLED using ITO on glass, it is verified that the flexible BEWOLED showed a similar or better electroluminescence (EL) performance.

Real-Time and High-Fidelity Simulation Environment for Autonomous Ground Vehicle Dynamics

Science.gov (United States)

Cameron, Jonathan; Myint, Steven; Kuo, Calvin; Jain, Abhi; Grip, Havard; Jayakumar, Paramsothy; Overholt, Jim

2013-01-01

This paper reports on a collaborative project between U.S. Army TARDEC and Jet Propulsion Laboratory (JPL) to develop a unmanned ground vehicle (UGV) simulation model using the ROAMS vehicle modeling framework. Besides modeling the physical suspension of the vehicle, the sensing and navigation of the HMMWV vehicle are simulated. Using models of urban and off-road environments, the HMMWV simulation was tested in several ways, including navigation in an urban environment with obstacle avoidance and the performance of a lane change maneuver.

High spatial resolution mapping of water quality and bathymetry with an autonomous underwater vehicle

Science.gov (United States)

Pampalone, Vincenzo; Milici, Barbara

2015-12-01

The drone Ecomapper AUV (Autonomous Underwater Vehicle) is a rare example of highly technological instrument in the environmental coastal monitoring field. The YSI EcoMapper is a one-man deployable, Autonomous Underwater Vehicle (AUV) designed to collect bathymetry and water quality data. The submarine-like vehicle follows a programmed course and employs sensors mounted in the nose to record pertinent information. Once the vehicle has started its mission, it operates independently of the user and utilizes GPS waypoints navigation to complete its programmed course. Throughout the course, the vehicle constantly steers toward the line drawn in the mission planning software (VectorMap), essentially following a more accurate road of coordinates instead of transversing waypoint-to-waypoint. It has been equipped with a Doppler Velocity Log (DVL) to increase its underwater navigation accuracy. Potential EcoMapper applications include baseline environmental mapping in freshwater, estuarine or near-coastal environments, bathymetric mapping, dissolved oxygen studies, event monitoring (algal blooms, storm impacts, low dissolved oxygen), non-point source studies, point-source dispersion mapping, security, search & rescue, inspection, shallow water mapping, thermal dissipation mapping of cooling outfalls, trace-dye studies. The AUV is used in the coastal area of the Augusta Bay (Italy), located in the eastern part of Sicily. Due to the heavy contamination generated by the several chemical and petrochemical industries active in the zone, the harbour was declared a Contaminated Site of National Interest. The ecomapper allows for a simultaneous data collection of water quality and bathymetric data providing a complete environmental mapping system of the Harbour.

Impacts and mitigation of excess diesel-related NOx emissions in 11 major vehicle markets

Science.gov (United States)

Anenberg, Susan C.; Miller, Joshua; Minjares, Ray; Du, Li; Henze, Daven K.; Lacey, Forrest; Malley, Christopher S.; Emberson, Lisa; Franco, Vicente; Klimont, Zbigniew; Heyes, Chris

2017-05-01

Vehicle emissions contribute to fine particulate matter (PM2.5) and tropospheric ozone air pollution, affecting human health, crop yields and climate worldwide. On-road diesel vehicles produce approximately 20 per cent of global anthropogenic emissions of nitrogen oxides (NOx), which are key PM2.5 and ozone precursors. Regulated NOx emission limits in leading markets have been progressively tightened, but current diesel vehicles emit far more NOx under real-world operating conditions than during laboratory certification testing. Here we show that across 11 markets, representing approximately 80 per cent of global diesel vehicle sales, nearly one-third of on-road heavy-duty diesel vehicle emissions and over half of on-road light-duty diesel vehicle emissions are in excess of certification limits. These excess emissions (totalling 4.6 million tons) are associated with about 38,000 PM2.5- and ozone-related premature deaths globally in 2015, including about 10 per cent of all ozone-related premature deaths in the 28 European Union member states. Heavy-duty vehicles are the dominant contributor to excess diesel NOx emissions and associated health impacts in almost all regions. Adopting and enforcing next-generation standards (more stringent than Euro 6/VI) could nearly eliminate real-world diesel-related NOx emissions in these markets, avoiding approximately 174,000 global PM2.5- and ozone-related premature deaths in 2040. Most of these benefits can be achieved by implementing Euro VI standards where they have not yet been adopted for heavy-duty vehicles.

Impacts and mitigation of excess diesel-related NOx emissions in 11 major vehicle markets.

Science.gov (United States)

Anenberg, Susan C; Miller, Joshua; Minjares, Ray; Du, Li; Henze, Daven K; Lacey, Forrest; Malley, Christopher S; Emberson, Lisa; Franco, Vicente; Klimont, Zbigniew; Heyes, Chris

2017-05-25

Vehicle emissions contribute to fine particulate matter (PM 2.5 ) and tropospheric ozone air pollution, affecting human health, crop yields and climate worldwide. On-road diesel vehicles produce approximately 20 per cent of global anthropogenic emissions of nitrogen oxides (NO x ), which are key PM 2.5 and ozone precursors. Regulated NO x emission limits in leading markets have been progressively tightened, but current diesel vehicles emit far more NO x under real-world operating conditions than during laboratory certification testing. Here we show that across 11 markets, representing approximately 80 per cent of global diesel vehicle sales, nearly one-third of on-road heavy-duty diesel vehicle emissions and over half of on-road light-duty diesel vehicle emissions are in excess of certification limits. These excess emissions (totalling 4.6 million tons) are associated with about 38,000 PM 2.5 - and ozone-related premature deaths globally in 2015, including about 10 per cent of all ozone-related premature deaths in the 28 European Union member states. Heavy-duty vehicles are the dominant contributor to excess diesel NO x emissions and associated health impacts in almost all regions. Adopting and enforcing next-generation standards (more stringent than Euro 6/VI) could nearly eliminate real-world diesel-related NO x emissions in these markets, avoiding approximately 174,000 global PM 2.5 - and ozone-related premature deaths in 2040. Most of these benefits can be achieved by implementing Euro VI standards where they have not yet been adopted for heavy-duty vehicles.

Evaluation of some emitted elements from selected small industries in Khartoum state

International Nuclear Information System (INIS)

Elboraie, Mahir Zein Elabdeen

1999-08-01

Employing x-ray fluorescence spectrometry, levels of calcium, chromium, iron, cobalt, nickel, copper, zinc and lead in the indoor aerosol environment of nile painting company, battery charging shop, Khartoum university printing press, Mirghany workshop, Burri power station and Sudanese mint company industries were measured. In the Nile painting company site, calcium, cobalt, nickel and lead exhibited high levels of concentration, whilst chromium, and copper displayed relatively high values with respect to their levels in the control site (Tutti Island). Iron exhibited a level nearly identical to that measured at the control site. No emission of zinc was monitored. In Battery Charging Shop site, Iron and lead, displayed the highest levels recorded, and calcium, chromium, copper, exhibited concentrations relatively high than the corresponding levels in the control site. Cobalt, nickel, and zinc have not been detected. The same trending was found in Khartoum University Printing Press site, with the exception that the level of iron is relatively high with respect to that of control site. In Mirghany Workshop site, calcium, iron, nickel, and zinc measured the highest values. Chromium, copper, and lead measured relatively high values with respect to their concentrations in the control site. No emission of cobalt was monitored. The average concentrations of calcium, iron, copper, and lead in Burri Power Station were nearly the same with that control site. Chromium, cobalt, nickel, and zinc, however, were not detected. In the indoor aerosol of Sudanese Mint Company site, cobalt, nickel, copper, and zinc, measured the highest values, whilst calcium, iron, chromium, and lead, displayed relatively high values with respect to their concentrations in the control site. The average concentrations of the elements under study in the indoor and outdoor aerosols of Sudanese Mint Company do not correlate to each other, but the outdoor measurements nearly resemble to those of the

Control of Electric Vehicle

OpenAIRE

Huang, Qi; Chen, Yong; Li, Jian

2010-01-01

In this chapter, the modeling of electric vehicle is discussed in detail. Then, the control of electric vehicle driven by different motors is discussed. Both brushed and brushless DC (Direct Current) motors are discussed. And for AC (Alternative Current) motors, the discussion is focused on induction motor and permanent magnet synchronous motor. The design of controllers for different motor-driven electric vehicle is discussed in-depth, and the tested high-performance control strategies for d...

Reliability analysis of high-speed tracked vehicles in the polish army

Directory of Open Access Journals (Sweden)

Kończak Jarosław

2017-06-01

Full Text Available The Polish Armed Forces use tracked vehicles that serve as a core element of the ground combat forces. These vehicles are capable of fighting in all kinds of terrain conditions, in any season of the year. Combat missions are often fought in areas where even no dirt roads are available. The present paper assesses the reliability of tracked vehicles in the context of their irregular operation, as well as service- and maintenance-related vulnerability.

Light emitting fabric technologies for photodynamic therapy.

Science.gov (United States)

Mordon, Serge; Cochrane, Cédric; Tylcz, Jean Baptiste; Betrouni, Nacim; Mortier, Laurent; Koncar, Vladan

2015-03-01

Photodynamic therapy (PDT) is considered to be a promising method for treating various types of cancer. A homogeneous and reproducible illumination during clinical PDT plays a determinant role in preventing under- or over-treatment. The development of flexible light sources would considerably improve the homogeneity of light delivery. The integration of optical fiber into flexible structures could offer an interesting alternative. This paper aims to describe different methods proposed to develop Side Emitting Optical Fibers (SEOF), and how these SEOF can be integrated in a flexible structure to improve light illumination of the skin during PDT. Four main techniques can be described: (i) light blanket integrating side-glowing optical fibers, (ii) light emitting panel composed of SEOF obtained by micro-perforations of the cladding, (iii) embroidery-based light emitting fabric, and (iv) woven-based light emitting fabric. Woven-based light emitting fabrics give the best performances: higher fluence rate, best homogeneity of light delivery, good flexibility. Copyright © 2014 Elsevier B.V. All rights reserved.

Side-emitting fiber optic position sensor

Science.gov (United States)

Weiss, Jonathan D [Albuquerque, NM

2008-02-12

A side-emitting fiber optic position sensor and method of determining an unknown position of an object by using the sensor. In one embodiment, a concentrated beam of light source illuminates the side of a side-emitting fiber optic at an unknown axial position along the fiber's length. Some of this side-illuminated light is in-scattered into the fiber and captured. As the captured light is guided down the fiber, its intensity decreases due to loss from side-emission away from the fiber and from bulk absorption within the fiber. By measuring the intensity of light emitted from one (or both) ends of the fiber with a photodetector(s), the axial position of the light source is determined by comparing the photodetector's signal to a calibrated response curve, look-up table, or by using a mathematical model. Alternatively, the side-emitting fiber is illuminated at one end, while a photodetector measures the intensity of light emitted from the side of the fiber, at an unknown position. As the photodetector moves further away from the illuminated end, the detector's signal strength decreases due to loss from side-emission and/or bulk absorption. As before, the detector's signal is correlated to a unique position along the fiber.

Perovskite Materials for Light-Emitting Diodes and Lasers.

Science.gov (United States)

Veldhuis, Sjoerd A; Boix, Pablo P; Yantara, Natalia; Li, Mingjie; Sum, Tze Chien; Mathews, Nripan; Mhaisalkar, Subodh G

2016-08-01

Organic-inorganic hybrid perovskites have cemented their position as an exceptional class of optoelectronic materials thanks to record photovoltaic efficiencies of 22.1%, as well as promising demonstrations of light-emitting diodes, lasers, and light-emitting transistors. Perovskite materials with photoluminescence quantum yields close to 100% and perovskite light-emitting diodes with external quantum efficiencies of 8% and current efficiencies of 43 cd A(-1) have been achieved. Although perovskite light-emitting devices are yet to become industrially relevant, in merely two years these devices have achieved the brightness and efficiencies that organic light-emitting diodes accomplished in two decades. Further advances will rely decisively on the multitude of compositional, structural variants that enable the formation of lower-dimensionality layered and three-dimensional perovskites, nanostructures, charge-transport materials, and device processing with architectural innovations. Here, the rapid advancements in perovskite light-emitting devices and lasers are reviewed. The key challenges in materials development, device fabrication, operational stability are addressed, and an outlook is presented that will address market viability of perovskite light-emitting devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Current Spreading Layer with High Transparency and Conductivity for near-ultraviolet light emitting diodes

DEFF Research Database (Denmark)

Lin, Li; Jensen, Flemming; Herstrøm, Berit

Transparent conductive aluminum-doped zinc oxide (AZO) layer was deposited on GaN-based near-ultraviolet (NUV) light emitting epitaxial wafers as current spreading layer by a sputtering process. Efforts were made to improve the electrical properties of AZO in order to produce ohmic contact....

Hyperspectral Image-Based Night-Time Vehicle Light Detection Using Spectral Normalization and Distance Mapper for Intelligent Headlight Control

Directory of Open Access Journals (Sweden)

Heekang Kim

2016-07-01

Full Text Available This paper proposes a vehicle light detection method using a hyperspectral camera instead of a Charge-Coupled Device (CCD or Complementary metal-Oxide-Semiconductor (CMOS camera for adaptive car headlamp control. To apply Intelligent Headlight Control (IHC, the vehicle headlights need to be detected. Headlights are comprised from a variety of lighting sources, such as Light Emitting Diodes (LEDs, High-intensity discharge (HID, and halogen lamps. In addition, rear lamps are made of LED and halogen lamp. This paper refers to the recent research in IHC. Some problems exist in the detection of headlights, such as erroneous detection of street lights or sign lights and the reflection plate of ego-car from CCD or CMOS images. To solve these problems, this study uses hyperspectral images because they have hundreds of bands and provide more information than a CCD or CMOS camera. Recent methods to detect headlights used the Spectral Angle Mapper (SAM, Spectral Correlation Mapper (SCM, and Euclidean Distance Mapper (EDM. The experimental results highlight the feasibility of the proposed method in three types of lights (LED, HID, and halogen.

Recent Advances in Conjugated Polymers for Light Emitting Devices

Science.gov (United States)

AlSalhi, Mohamad Saleh; Alam, Javed; Dass, Lawrence Arockiasamy; Raja, Mohan

2011-01-01

A recent advance in the field of light emitting polymers has been the discovery of electroluminescent conjugated polymers, that is, kind of fluorescent polymers that emit light when excited by the flow of an electric current. These new generation fluorescent materials may now challenge the domination by inorganic semiconductor materials of the commercial market in light-emitting devices such as light-emitting diodes (LED) and polymer laser devices. This review provides information on unique properties of conjugated polymers and how they have been optimized to generate these properties. The review is organized in three sections focusing on the major advances in light emitting materials, recent literature survey and understanding the desirable properties as well as modern solid state lighting and displays. Recently, developed conjugated polymers are also functioning as roll-up displays for computers and mobile phones, flexible solar panels for power portable equipment as well as organic light emitting diodes in displays, in which television screens, luminous traffic, information signs, and light-emitting wallpaper in homes are also expected to broaden the use of conjugated polymers as light emitting polymers. The purpose of this review paper is to examine conjugated polymers in light emitting diodes (LEDs) in addition to organic solid state laser. Furthermore, since conjugated polymers have been approved as light-emitting organic materials similar to inorganic semiconductors, it is clear to motivate these organic light-emitting devices (OLEDs) and organic lasers for modern lighting in terms of energy saving ability. In addition, future aspects of conjugated polymers in LEDs were also highlighted in this review. PMID:21673938

A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

International Nuclear Information System (INIS)

AntolIn, P; Goicolea, J M; Astiz, M A; Alonso, A

2010-01-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

Science.gov (United States)

Antolín, P.; Goicolea, J. M.; Astiz, M. A.; Alonso, A.

2010-06-01

Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

Color optimization of conjugated-polymer/InGaN hybrid white light emitting diodes by incomplete energy transfer

International Nuclear Information System (INIS)

Chang, Chi-Jung; Lai, Chun-Feng; Madhusudhana Reddy, P.; Chen, Yung-Lin; Chiou, Wei-Yung; Chang, Shinn-Jen

2015-01-01

By using the wavelength conversion method, white light emitting diodes (WLEDs) were produced by applying mixtures of polysiloxane and fluorescent polymers on InGaN based light emitting diodes. UV curable organic–inorganic hybrid materials with high refractive index (1.561), compromised optical, thermal and mechanical properties was used as encapsulants. Red light emitting fluorescent FABD polymer (with 9,9-dioctylfluorene (F), anthracene (A) and 2,1,3-benzothiadiazole (B), and 4,7-bis(2-thienyl)-2,1,3-benzothiadiazole (D) repeating units) and green light emitting fluorescent FAB polymer were used as wavelength converters. The encapsulant/fluorescent polymer mixture and InGaN produce the white light by incomplete energy transfer mechanism. WLEDs with high color rendering index (CRI, about 93), and tunable correlated color temperature (CCT) properties can be produced by controlling the composition and chemical structures of encapsulating polymer and fluorescent polymer in hybrid materials, offering cool-white and neutral-white LEDs. - Highlights: • Highly efficient white light-emitting diodes (WLEDs) were produced. • Conjugated-polymer/InGaN hybrid WLEDs by incomplete energy transfer mechanism. • WLEDs with high color-rendering index and tunable correlated color temperature. • Polysiloxane encapsulant with superior optical, mechanical and thermal properties

A review of fundamental drivers governing the emissions, dispersion and exposure to vehicle-emitted nanoparticles at signalised traffic intersections

Science.gov (United States)

Goel, Anju; Kumar, Prashant

2014-11-01

Signalised traffic intersections (TIs) are considered as pollution hot-spots in urban areas, but the knowledge of fundamental drivers governing emission, dispersion and exposure to vehicle-emitted nanoparticles (represented by particle number concentration, PNC) at TIs is yet to be established. A number of following key factors, which are important for developing an emission and exposure framework for nanoparticles at TIs, are critically evaluated as a part of this review article. In particular, (i) how do traffic- and wind-flow features affect emission and dispersion of nanoparticles? (ii) What levels of PNCs can be typically expected under diverse signal- and traffic-conditions? (iii) How does the traffic driving condition affect the particle number (PN) emissions and the particle number emission factors (PNEF)? (iv) What is the relative importance of particle transformation processes in affecting the PNCs? (v) What are important considerations for the dispersion modelling of nanoparticles? (vi) What is extent of exposure at TIs with respect to other locations in urban settings? (vii) What are the gaps in current knowledge on this topic where the future research should focus? We found that the accurate consideration of dynamic traffic flow features at TIs is essential for reliable estimates of PN emissions. Wind flow features at TIs are generally complex to generalise. Only a few field studies have monitored PNCs at TIs until now, reporting over an order of magnitude larger peak PNCs (0.7-5.4 × 105 cm-3) compared with average PNCs at typical roadsides (˜0.3 × 105 cm-3). The PN emission and thus the PNEFs can be up to an order of magnitude higher during acceleration compared with steady speed conditions. The time scale analysis suggests nucleation as the fastest transformation process, followed by dilution, deposition, coagulation and condensation. Consideration of appropriate flow features, PNEFs and transformation processes emerged as important parameters for

High-Color-Quality White Top-Emitting Organic Electroluminescent Devices Based on Both Exciton and Electroplex Emission

Science.gov (United States)

Zhang, Mingxiao; Chen, Zhijian; Xiao, Lixin; Qu, Bo; Gong, Qihuang

2011-08-01

A high-color-quality white top-emitting organic electroluminescent device (TOLED) with a simple structure was fabricated using both exciton and electroplex emission. White emission was achieved by combining the exciton emission of 4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi) and the broad band emission of electroplex generated between DPVBi and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP). The white emission spectra showed excellent stability at different bias voltages. By inserting a blend film of DPVBi:BCP and adjusting the ratio of DPVBi to BCP in the blend film, the CIE coordinates of the white emission can be tuned to (0.30, 0.33) and the electroluminescence efficiency can also be enhanced.

Highly efficient phosphor-converted white organic light-emitting diodes with moderate microcavity and light-recycling filters.

Science.gov (United States)

Cho, Sang-Hwan; Oh, Jeong Rok; Park, Hoo Keun; Kim, Hyoung Kun; Lee, Yong-Hee; Lee, Jae-Gab; Do, Young Rag

2010-01-18

We demonstrate the combined effects of a microcavity structure and light-recycling filters (LRFs) on the forward electrical efficiency of phosphor-converted white organic light-emitting diodes (pc-WOLEDs). The introduction of a single pair of low- and high-index layers (SiO(2)/TiO(2)) improves the blue emission from blue OLED and the insertion of blue-passing and yellow-reflecting LRFs enhances the forward yellow emission from the YAG:Ce(3+) phosphors layers. The enhancement of the luminous efficacy of the forward white emission is 1.92 times that of a conventional pc-WOLED with color coordinates of (0.34, 0.34) and a correlated color temperature of about 4800 K.

An overview of experimental results and dispersion modelling of nanoparticles in the wake of moving vehicles

International Nuclear Information System (INIS)

Carpentieri, Matteo; Kumar, Prashant; Robins, Alan

2011-01-01

Understanding the transformation of nanoparticles emitted from vehicles is essential for developing appropriate methods for treating fine scale particle dynamics in dispersion models. This article provides an overview of significant research work relevant to modelling the dispersion of pollutants, especially nanoparticles, in the wake of vehicles. Literature on vehicle wakes and nanoparticle dispersion is reviewed, taking into account field measurements, wind tunnel experiments and mathematical approaches. Field measurements and modelling studies highlighted the very short time scales associated with nanoparticle transformations in the first stages after the emission. These transformations strongly interact with the flow and turbulence fields immediately behind the vehicle, hence the need of characterising in detail the mixing processes in the vehicle wake. Very few studies have analysed this interaction and more research is needed to build a basis for model development. A possible approach is proposed and areas of further investigation identified. - Research highlights: → Nanoparticle emissions experience very short transformation time scales. → Vehicle wakes need to be characterised to analyse nanoparticle dispersion. → Fast response measurements of nanoparticle evolution in vehicle wakes are very rare. → Wind tunnel methodologies can be further improved to include nanoparticle dynamics. → A simple mathematical approach has been proposed for future development. - The transformation of nanoparticles and the flow characteristics in both the near and far wake regions must be understood in order to develop mathematical models.

Particulate matter speciation profiles for light-duty gasoline vehicles in the United States.

Science.gov (United States)

Sonntag, Darrell B; Baldauf, Richard W; Yanca, Catherine A; Fulper, Carl R

2014-05-01

Representative profiles for particulate matter particles less than or equal to 2.5 microm (PM2.5) are developed from the Kansas City Light-Duty Vehicle Emissions Study for use in the US. Environmental Protection Agency (EPA) vehicle emission model, the Motor Vehicle Emission Simulator (MOVES), and for inclusion in the EPA SPECIATE database for speciation profiles. The profiles are compatible with the inputs of current photochemical air quality models, including the Community Multiscale Air Quality Aerosol Module Version 6 (AE6). The composition of light-duty gasoline PM2.5 emissions differs significantly between cold start and hot stabilized running emissions, and between older and newer vehicles, reflecting both impacts of aging/deterioration and changes in vehicle technology. Fleet-average PM2.5 profiles are estimated for cold start and hot stabilized running emission processes. Fleet-average profiles are calculated to include emissions from deteriorated high-emitting vehicles that are expected to continue to contribute disproportionately to the fleet-wide PM2.5 emissions into the future. The profiles are calculated using a weighted average of the PM2.5 composition according to the contribution of PM2.5 emissions from each class of vehicles in the on-road gasoline fleet in the Kansas City Metropolitan Statistical Area. The paper introduces methods to exclude insignificant measurements, correct for organic carbon positive artifact, and control for contamination from the testing infrastructure in developing speciation profiles. The uncertainty of the PM2.5 species fraction in each profile is quantified using sampling survey analysis methods. The primary use of the profiles is to develop PM2.5 emissions inventories for the United States, but the profiles may also be used in source apportionment, atmospheric modeling, and exposure assessment, and as a basis for light-duty gasoline emission profiles for countries with limited data. PM2.5 speciation profiles were

Analysis of sound pressure levels emitted by children's toys.

Science.gov (United States)

Sleifer, Pricila; Gonçalves, Maiara Santos; Tomasi, Marinês; Gomes, Erissandra

2013-06-01

To verify the levels of sound pressure emitted by non-certified children's toys. Cross-sectional study of sound toys available at popular retail stores of the so-called informal sector. Electronic, mechanical, and musical toys were analyzed. The measurement of each product was carried out by an acoustic engineer in an acoustically isolated booth, by a decibel meter. To obtain the sound parameters of intensity and frequency, the toys were set to produce sounds at a distance of 10 and 50cm from the researcher's ear. The intensity of sound pressure [dB(A)] and the frequency in hertz (Hz) were measured. 48 toys were evaluated. The mean sound pressure 10cm from the ear was 102±10 dB(A), and at 50cm, 94±8 dB(A), with ptoys was above 85dB(A). The frequency ranged from 413 to 6,635Hz, with 56.3% of toys emitting frequency higher than 2,000Hz. The majority of toys assessed in this research emitted a high level of sound pressure.

Smart design to resolve spectral overlapping of phosphor-in-glass for high-powered remote-type white light-emitting devices.

Science.gov (United States)

Lee, Jin Seok; Arunkumar, P; Kim, Sunghoon; Lee, In Jae; Lee, Hyungeui; Im, Won Bin

2014-02-15

The white light-emitting diode (WLED) is a state-of-the-art solid state technology, which has replaced conventional lighting systems due to its reduced energy consumption, its reliability, and long life. However, the WLED presents acute challenges in device engineering, due to its lack of color purity, efficacy, and thermal stability of the lighting devices. The prime cause for inadequacies in color purity and luminous efficiency is the spectral overlapping of red components with yellow/green emissions when generating white light by pumping a blue InGaN chip with yellow YAG:Ce³⁺ phosphor, where red phosphor is included, to compensate for deficiencies in the red region. An innovative strategy was formulated to resolve this spectral overlapping by alternatively arranging phosphor-in-glass (PiG) through cutting and reassembling the commercial red CaAlSiN₃:Eu²⁺ and green Lu₃Al₅O₁₂:Ce³⁺ PiG. PiGs were fabricated using glass frits with a low softening temperature of 600°C, which exhibited excellent thermal stability and high transparency, improving life time even at an operating temperature of 200°C. This strategy overcomes the spectral overlapping issue more efficiently than the randomly mixed and patented stacking design of multiple phosphors for a remote-type WLED. The protocol for the current design of PiG possesses excellent thermal and chemical stability with high luminous efficiency and color purity is an attempt to make smarter solid state lighting for high-powered remote-type white light-emitting devices.

Unmanned Aerial Vehicles for High-Throughput Phenotyping and Agronomic Research.

Directory of Open Access Journals (Sweden)

Yeyin Shi

Full Text Available Advances in automation and data science have led agriculturists to seek real-time, high-quality, high-volume crop data to accelerate crop improvement through breeding and to optimize agronomic practices. Breeders have recently gained massive data-collection capability in genome sequencing of plants. Faster phenotypic trait data collection and analysis relative to genetic data leads to faster and better selections in crop improvement. Furthermore, faster and higher-resolution crop data collection leads to greater capability for scientists and growers to improve precision-agriculture practices on increasingly larger farms; e.g., site-specific application of water and nutrients. Unmanned aerial vehicles (UAVs have recently gained traction as agricultural data collection systems. Using UAVs for agricultural remote sensing is an innovative technology that differs from traditional remote sensing in more ways than strictly higher-resolution images; it provides many new and unique possibilities, as well as new and unique challenges. Herein we report on processes and lessons learned from year 1-the summer 2015 and winter 2016 growing seasons-of a large multidisciplinary project evaluating UAV images across a range of breeding and agronomic research trials on a large research farm. Included are team and project planning, UAV and sensor selection and integration, and data collection and analysis workflow. The study involved many crops and both breeding plots and agronomic fields. The project's goal was to develop methods for UAVs to collect high-quality, high-volume crop data with fast turnaround time to field scientists. The project included five teams: Administration, Flight Operations, Sensors, Data Management, and Field Research. Four case studies involving multiple crops in breeding and agronomic applications add practical descriptive detail. Lessons learned include critical information on sensors, air vehicles, and configuration parameters for both

Driving Performance After Self-Regulated Control Transitions in Highly Automated Vehicles.

Science.gov (United States)

Eriksson, Alexander; Stanton, Neville A

2017-12-01

This study aims to explore whether driver-paced, noncritical transitions of control may counteract some of the aftereffects observed in the contemporary literature, resulting in higher levels of vehicle control. Research into control transitions in highly automated driving has focused on urgent scenarios where drivers are given a relatively short time span to respond to a request to resume manual control, resulting in seemingly scrambled control when manual control is resumed. Twenty-six drivers drove two scenarios with an automated driving feature activated. Drivers were asked to read a newspaper or monitor the system and relinquish or resume control from the automation when prompted by vehicle systems. Driving performance in terms of lane positioning and steering behavior was assessed for 20 seconds post resuming control to capture the resulting level of control. It was found that lane positioning was virtually unaffected for the duration of the 20-second time span in both automated conditions compared to the manual baseline when drivers resumed manual control; however, significant increases in the standard deviation of steering input were found for both automated conditions compared to baseline. No significant differences were found between the two automated conditions. The results indicate that when drivers self-paced the transfer back to manual control they exhibit less of the detrimental effects observed in system-paced conditions. It was shown that self-paced transitions could reduce the risk of accidents near the edge of the operational design domain. Vehicle manufacturers must consider these benefits when designing contemporary systems.

Emissions and Cost Implications of Controlled Electric Vehicle Charging in the U.S. PJM Interconnection.

Science.gov (United States)

Weis, Allison; Michalek, Jeremy J; Jaramillo, Paulina; Lueken, Roger

2015-05-05

We develop a unit commitment and economic dispatch model to estimate the operation costs and the air emissions externality costs attributable to new electric vehicle electricity demand under controlled vs uncontrolled charging schemes. We focus our analysis on the PJM Interconnection and use scenarios that characterize (1) the most recent power plant fleet for which sufficient data are available, (2) a hypothetical 2018 power plant fleet that reflects upcoming plant retirements, and (3) the 2018 fleet with increased wind capacity. We find that controlled electric vehicle charging can reduce associated generation costs by 23%-34% in part by shifting loads to lower-cost, higher-emitting coal plants. This shift results in increased externality costs of health and environmental damages from increased air pollution. On balance, we find that controlled charging of electric vehicles produces negative net social benefits in the recent PJM grid but could have positive net social benefits in a future grid with sufficient coal retirements and wind penetration.

Automated Vehicles Symposium 2014

CERN Document Server

Beiker, Sven; Road Vehicle Automation 2

2015-01-01

This paper collection is the second volume of the LNMOB series on Road Vehicle Automation. The book contains a comprehensive review of current technical, socio-economic, and legal perspectives written by experts coming from public authorities, companies and universities in the U.S., Europe and Japan. It originates from the Automated Vehicle Symposium 2014, which was jointly organized by the Association for Unmanned Vehicle Systems International (AUVSI) and the Transportation Research Board (TRB) in Burlingame, CA, in July 2014. The contributions discuss the challenges arising from the integration of highly automated and self-driving vehicles into the transportation system, with a focus on human factors and different deployment scenarios. This book is an indispensable source of information for academic researchers, industrial engineers, and policy makers interested in the topic of road vehicle automation.

Nanopatterned yttrium aluminum garnet phosphor incorporated film for high-brightness GaN-based white light emitting diodes

International Nuclear Information System (INIS)

Cho, Joong-yeon; Park, Sang-Jun; Ahn, Jinho; Lee, Heon

2014-01-01

In this study, we fabricated high-brightness white light emitting diodes (LEDs) by developing a nanopatterned yttrium aluminum garnet (YAG) phosphor-incorporated film. White light can be obtained by mixing blue light from a GaN-based LED and yellow light of the YAG phosphor-incorporated film. If white light sources can be fabricated by exciting proper yellow phosphor using blue light, then these sources can be used instead of the conventional fluorescent lamps with a UV source, for backlighting of displays. In this work, a moth-eye structure was formed on the YAG phosphor-incorporated film by direct spin-on glass (SOG) printing. The moth-eye structures have been investigated to improve light transmittance in various optoelectronic devices, including photovoltaic solar cells, light emitting diodes, and displays, because of their anti-reflection property. Direct SOG printing, which is a simple, easy, and relatively inexpensive process, can be used to fabricate nanoscale structures. After direct SOG printing, the moth-eye structure with a diameter of 220 nm was formed uniformly on the YAG phosphor-incorporated film. As a result of moth-eye patterning on the YAG phosphor-incorporated film, the light output power of a white LED with a patterned YAG phosphor-incorporated film increased to up to 13% higher than that of a white LED with a non-patterned film. - Highlights: • GaN-based high-brightness white LED was prepared using patterned YAG phosphor-incorporated films. • Direct hydrogen silsesquioxane printing was used to form moth-eye patterns on the YAG films. • The electroluminescence intensity of the white LED was enhanced by up to 14.9%

Nanopatterned yttrium aluminum garnet phosphor incorporated film for high-brightness GaN-based white light emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Cho, Joong-yeon; Park, Sang-Jun [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Ahn, Jinho, E-mail: jhahn@hanyang.ac.kr [Department of Material Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Heon, E-mail: heonlee@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

2014-11-03

In this study, we fabricated high-brightness white light emitting diodes (LEDs) by developing a nanopatterned yttrium aluminum garnet (YAG) phosphor-incorporated film. White light can be obtained by mixing blue light from a GaN-based LED and yellow light of the YAG phosphor-incorporated film. If white light sources can be fabricated by exciting proper yellow phosphor using blue light, then these sources can be used instead of the conventional fluorescent lamps with a UV source, for backlighting of displays. In this work, a moth-eye structure was formed on the YAG phosphor-incorporated film by direct spin-on glass (SOG) printing. The moth-eye structures have been investigated to improve light transmittance in various optoelectronic devices, including photovoltaic solar cells, light emitting diodes, and displays, because of their anti-reflection property. Direct SOG printing, which is a simple, easy, and relatively inexpensive process, can be used to fabricate nanoscale structures. After direct SOG printing, the moth-eye structure with a diameter of 220 nm was formed uniformly on the YAG phosphor-incorporated film. As a result of moth-eye patterning on the YAG phosphor-incorporated film, the light output power of a white LED with a patterned YAG phosphor-incorporated film increased to up to 13% higher than that of a white LED with a non-patterned film. - Highlights: • GaN-based high-brightness white LED was prepared using patterned YAG phosphor-incorporated films. • Direct hydrogen silsesquioxane printing was used to form moth-eye patterns on the YAG films. • The electroluminescence intensity of the white LED was enhanced by up to 14.9%.

Comparison performance of split plug-in hybrid electric vehicle and hybrid electric vehicle using ADVISOR

Directory of Open Access Journals (Sweden)

Mohd Rashid Muhammad Ikram

2017-01-01

Full Text Available Electric vehicle suffers from relatively short range and long charging times and consequently has not become an acceptable solution to the automotive consumer. The addition of an internal combustion engine to extend the range of the electric vehicle is one method of exploiting the high efficiency and lack of emissions of the electric vehicle while retaining the range and convenient refuelling times of a conventional gasoline powered vehicle. The term that describes this type of vehicle is a hybrid electric vehicle. Many configurations of hybrid electric vehicles have been designed and implemented, namely the series, parallel and power-split configurations. This paper discusses the comparison between Split Plug-in Hybrid Electric Vehicle(SPHEV and Hybrid Electric Vehicle(HEV. Modelling methods such as physics-based Resistive Companion Form technique and Bond Graph method are presented with powertrain component and system modelling examples. The modelling and simulation capability of existing tools such as ADvanced VehIcle SimulatOR (ADVISOR is demonstrated through application examples. Since power electronics is indispensable in hybrid vehicles, the issue of numerical oscillations in dynamic simulations involving power electronics is briefly addressed.

Effects of emitted electron temperature on the plasma sheath

International Nuclear Information System (INIS)

Sheehan, J. P.; Kaganovich, I. D.; Wang, H.; Raitses, Y.; Sydorenko, D.; Hershkowitz, N.

2014-01-01

It has long been known that electron emission from a surface significantly affects the sheath surrounding that surface. Typical fluid theory of a planar sheath with emitted electrons assumes that the plasma electrons follow the Boltzmann relation and the emitted electrons are emitted with zero energy and predicts a potential drop of 1.03T e /e across the sheath in the floating condition. By considering the modified velocity distribution function caused by plasma electrons lost to the wall and the half-Maxwellian distribution of the emitted electrons, it is shown that ratio of plasma electron temperature to emitted electron temperature significantly affects the sheath potential when the plasma electron temperature is within an order of magnitude of the emitted electron temperature. When the plasma electron temperature equals the emitted electron temperature the emissive sheath potential goes to zero. One dimensional particle-in-cell simulations corroborate the predictions made by this theory. The effects of the addition of a monoenergetic electron beam to the Maxwellian plasma electrons were explored, showing that the emissive sheath potential is close to the beam energy only when the emitted electron flux is less than the beam flux

Improved Line Tracking System for Autonomous Navigation of High-Speed Vehicle

Directory of Open Access Journals (Sweden)

Yahya Zare Khafri

2012-07-01

Full Text Available Line tracking navigation is one of the most widely techniques used in the robot navigation. In this paper, a customized line tracking system is proposed for autonomous navigation of high speed vehicles. In the presented system, auxiliary information -in addition to the road path- is added to the tracking lines such as locations of turn and intersections in the real roads. Moreover, the geometric position of line sensors is re-designed enables the high rate sensing with higher reliability. Finally, a light-weight navigation algorithm is proposed allow the high-speed movement using a reasonable processing power. This system is implemented on a MIPS-based embedded processor and experimental results with this embedded system show more than 98% accuracy at 200km/h with a 1GHz processor is viable.

Visiting Vehicle Ground Trajectory Tool

Science.gov (United States)

Hamm, Dustin

2013-01-01

The International Space Station (ISS) Visiting Vehicle Group needed a targeting tool for vehicles that rendezvous with the ISS. The Visiting Vehicle Ground Trajectory targeting tool provides the ability to perform both realtime and planning operations for the Visiting Vehicle Group. This tool provides a highly reconfigurable base, which allows the Visiting Vehicle Group to perform their work. The application is composed of a telemetry processing function, a relative motion function, a targeting function, a vector view, and 2D/3D world map type graphics. The software tool provides the ability to plan a rendezvous trajectory for vehicles that visit the ISS. It models these relative trajectories using planned and realtime data from the vehicle. The tool monitors ongoing rendezvous trajectory relative motion, and ensures visiting vehicles stay within agreed corridors. The software provides the ability to update or re-plan a rendezvous to support contingency operations. Adding new parameters and incorporating them into the system was previously not available on-the-fly. If an unanticipated capability wasn't discovered until the vehicle was flying, there was no way to update things.

High-Energy Laser Weapon Integration with Ground Vehicles

National Research Council Canada - National Science Library

Hafften, Michael; Stratton, Robert

2004-01-01

.... The architecture of an electric, solid-state HEL weapon system would likely be based upon a hybrid electric vehicle that provides a common electrical power source for the propulsion and weapon subsystems...

Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

Energy Technology Data Exchange (ETDEWEB)

Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

1989-04-01

This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

Deriving fuel-based emission factor thresholds to interpret heavy-duty vehicle roadside plume measurements.

Science.gov (United States)

Quiros, David C; Smith, Jeremy D; Ham, Walter A; Robertson, William H; Huai, Tao; Ayala, Alberto; Hu, Shaohua

2018-04-13

Remote sensing devices have been used for decades to measure gaseous emissions from individual vehicles at the roadside. Systems have also been developed that entrain diluted exhaust and can also measure particulate matter (PM) emissions. In 2015, the California Air Resources Board (CARB) reported that 8% of in-field diesel particulate filters (DPF) on heavy-duty (HD) vehicles were malfunctioning and emitted about 70% of total diesel PM emissions from the DPF-equipped fleet. A new high-emitter problem in the heavy-duty vehicle fleet had emerged. Roadside exhaust plume measurements reflect a snapshot of real-world operation, typically lasting several seconds. In order to relate roadside plume measurements to laboratory emission tests, we analyzed carbon dioxide (CO 2 ), oxides of nitrogen (NO X ), and PM emissions collected from four HD vehicles during several driving cycles on a chassis dynamometer. We examined the fuel-based emission factors corresponding to possible exceedances of emission standards as a function of vehicle power. Our analysis suggests that a typical HD vehicle will exceed the model year (MY) 2010 emission standards (of 0.2 g NO X /bhp-hr and 0.01 g PM/bhp-hr) by three times when fuel-based emission factors are 9.3 g NO X /kg fuel and 0.11 g PM/kg using the roadside plume measurement approach. Reported limits correspond to 99% confidence levels, which were calculated using the detection uncertainty of emissions analyzers, accuracy of vehicle power calculations, and actual emissions variability of fixed operational parameters. The PM threshold was determined for acceleration events between 0.47 and 1.4 mph/sec only, and the NO X threshold was derived from measurements where aftertreatment temperature was above 200°C. Anticipating a growing interest in real-world driving emissions, widespread implementation of roadside exhaust plume measurements as a compliment to in-use vehicle programs may benefit from expanding this analysis to a larger

Nanostructured High Performance Ultraviolet and Blue Light Emitting Diodes for Solid State Lighting

Energy Technology Data Exchange (ETDEWEB)

Arto V. Nurmikko; Jung Han

2007-03-31

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 near ultraviolet for Solid State Lighting applications. Accomplishments in the duration of the contract period include (i) new means of synthesizing AlGaN and InN quantum dots by droplet heteroepitaxy, (ii) synthesis of AlGaInN nanowires as building blocks for GaN-based microcavity devices, (iii) progress towards direct epitaxial alignment of the dense arrays of nanowires, (iv) observation and measurements of stimulated emission in dense InGaN nanopost arrays, (v) design and fabrication of InGaN photonic crystal emitters, and (vi) observation and measurements of enhanced fluorescence from coupled quantum dot and plasmonic nanostructures. 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.

Enhanced device performances of a new inverted top-emitting OLEDs with relatively thick Ag electrode.

Science.gov (United States)

Park, So-Ra; Suh, Min Chul

2018-02-19

To improve the device performances of top-emitting organic light emitting diodes (TEOLEDs), we developed a new inverted TEOLEDs structure with silver (Ag) metal as a semi-transparent top electrode. Especially, we found that the use of relatively thick Ag electrode without using any carrier injection layer is beneficial to realize highly efficient device performances. Also, we could insert very thick overlying hole transport layer (HTL) on the emitting layer (EML) which could be very helpful to suppress the surface plasmon polariton (SPP) coupling if it is applied to the common bottom-emission OLEDs (BEOLEDs). As a result, we could realize noteworthy high current efficiency of approximately ~188.1 cd/A in our new inverted TEOLEDs with 25 nm thick Ag electrode.

Single-mode temperature and polarisation-stable high-speed 850nm vertical cavity surface emitting lasers

International Nuclear Information System (INIS)

Nazaruk, D E; Blokhin, S A; Maleev, N A; Bobrov, M A; Pavlov, M M; Kulagina, M M; Vashanova, K A; Zadiranov, Yu M; Ustinov, V M; Kuzmenkov, A G; Vasil'ev, A P; Gladyshev, A G; Blokhin, A A; Salut, 7 Larina Str, N Novgorod, 603950 (Russian Federation))" data-affiliation=" (JSV Salut, 7 Larina Str, N Novgorod, 603950 (Russian Federation))" >Fefelov, A G

2014-01-01

A new intracavity-contacted design to realize temperature and polarization-stable high-speed single-mode 850 nm vertical cavity surface emitting lasers (VCSELs) grown by molecular-beam epitaxy is proposed. Temperature dependences of static and dynamic characteristics of the 4.5 pm oxide aperture InGaAlAs VCSEL were investigated in detail. Due to optimal gain-cavity detuning and enhanced carrier localization in the active region the threshold current remains below 0.75 mA for the temperature range within 20-90°C, while the output power exceeds 1 mW up to 90°C. Single-mode operation with side-mode suppression ratio higher than 30 dB and orthogonal polarization suppression ratio more than 18 dB was obtained in the whole current and temperature operation range. Device demonstrates serial resistance less than 250 Ohm, which is rather low for any type of single-mode short- wavelength VCSELs. VCSEL demonstrates temperature robust high-speed operation with modulation bandwidth higher than 13 GHz in the entire temperature range of 20-90°C. Despite high resonance frequency the high-speed performance of developed VCSELs was limited by the cut-off frequency of the parasitic low pass filter created by device resistances and capacitances. The proposed design is promising for single-mode high-speed VCSEL applications in a wide spectral range

An Exciplex Host for Deep-Blue Phosphorescent Organic Light-Emitting Diodes.

Science.gov (United States)

Lim, Hyoungcheol; Shin, Hyun; Kim, Kwon-Hyeon; Yoo, Seung-Jun; Huh, Jin-Suk; Kim, Jang-Joo

2017-11-01

The use of exciplex hosts is attractive for high-performance phosphorescent organic light-emitting diodes (PhOLEDs) and thermally activated delayed fluorescence OLEDs, which have high external quantum efficiency, low driving voltage, and low efficiency roll-off. However, exciplex hosts for deep-blue OLEDs have not yet been reported because of the difficulties in identifying suitable molecules. Here, we report a deep-blue-emitting exciplex system with an exciplex energy of 3.0 eV. It is composed of a carbazole-based hole-transporting material (mCP) and a phosphine-oxide-based electron-transporting material (BM-A10). The blue PhOLEDs exhibited maximum external quantum efficiency of 24% with CIE coordinates of (0.15, 0.21) and longer lifetime than the single host devices.

High-efficiency and heavily doped organic light-emitting devices based on quench-resistant red iridium complex

Energy Technology Data Exchange (ETDEWEB)

Wang, Qi [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Yu, Junsheng, E-mail: jsyu@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Zhao, Juan; Wang, Jun [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu 610054 (China); Li, Ming [College of Chemistry, Sichuan University, Chengdu 610064 (China); Lu, Zhiyun, E-mail: luzhiyun@scu.edu.cn [College of Chemistry, Sichuan University, Chengdu 610064 (China)

2013-02-15

Highly efficient red phosphorescent organic light-emitting devices had been fabricated using a new iridium complex, bis[2-(9,9-dimethyl-9H-fluoren-2-yl) benzothiazolato-N,C{sup 2'}]iridium(III) (acetylacetonate) [(fbt){sub 2}Ir(acac)] as phosphor. With a high doping concentration of 15 wt%, the device exhibited a maximum luminance efficiency, power efficiency and external quantum efficiency (EQE) of 35.2 cd/A, 21.3 lm/W, 18.2%, respectively, indicating an excellent quench-resistant property of (fbt){sub 2}Ir(acac). The results are appealing towards the development of 'easy-to-make' OLEDs. It has been demonstrated that the high efficiency arises from more balanced charge carriers in the emissive layer. - Highlight: Black-Right-Pointing-Pointer We obtained efficient OLEDs based on newly synthesized quench-resistant phosphor. Black-Right-Pointing-Pointer Peak performance was obtained with 15 wt% (fbt){sub 2}Ir(acac) doped device. Black-Right-Pointing-Pointer Our devices gave one of the best performance among heavily-doped red devices. Black-Right-Pointing-Pointer Balanced carrier transport is crucial for the high performance of our devices.

Highly efficient fully flexible indium tin oxide free organic light emitting diodes fabricated directly on barrier-foil

International Nuclear Information System (INIS)

Bocksrocker, Tobias; Hülsmann, Neele; Eschenbaum, Carsten; Pargner, Andreas; Höfle, Stefan; Maier-Flaig, Florian; Lemmer, Uli

2013-01-01

We present a simple method for the fabrication of highly conductive and fully flexible metal/polymer hybrid anodes for efficient organic light emitting diodes (OLEDs). By incorporating ultra-thin metal grids into a conductive polymer, we fabricated anodes with very low sheet resistances and high transparency. After optimizing the metallic grid, OLEDs with these hybrid anodes are superior to OLEDs with standard indium tin oxide (ITO) anodes in luminous efficacy by a factor of ∼ 2. Furthermore, the sheet resistance can be reduced by up to an order of magnitude compared to ITO on polyethylene terephthalate (PET). The devices show a very low turn-on voltage and the hybrid anodes do not change the emissive spectra of the OLEDs. In addition, we fabricated the anodes directly on a barrier foil, making the double sided encapsulation of a typically used PET-substrate unnecessary

Printing method for organic light emitting device lighting

Science.gov (United States)

Ki, Hyun Chul; Kim, Seon Hoon; Kim, Doo-Gun; Kim, Tae-Un; Kim, Snag-Gi; Hong, Kyung-Jin; So, Soon-Yeol

2013-03-01

Organic Light Emitting Device (OLED) has a characteristic to change the electric energy into the light when the electric field is applied to the organic material. OLED is currently employed as a light source for the lighting tools because research has extensively progressed in the improvement of luminance, efficiency, and life time. OLED is widely used in the plate display device because of a simple manufacture process and high emitting efficiency. But most of OLED lighting projects were used the vacuum evaporator (thermal evaporator) with low molecular. Although printing method has lower efficiency and life time of OLED than vacuum evaporator method, projects of printing OLED actively are progressed because was possible to combine with flexible substrate and printing technology. Printing technology is ink-jet, screen printing and slot coating. This printing method allows for low cost and mass production techniques and large substrates. In this research, we have proposed inkjet printing for organic light-emitting devices has the dominant method of thick film deposition because of its low cost and simple processing. In this research, the fabrication of the passive matrix OLED is achieved by inkjet printing, using a polymer phosphorescent ink. We are measured optical and electrical characteristics of OLED.

ELECTROMAGNETIC BIOSPHERE POLLUTION BY MOTOR TRANSPORT (VEHICLES, ELECTRIC VEHICLES, HYBRID VEHICLES

Directory of Open Access Journals (Sweden)

S. Selivanov

2009-01-01

Full Text Available The physics of the electromagnetic field is considered. The analysis of electromagnetic radiation on the human-being, the origin of which is the vehicle the electric vehicle, the hybrid vehicle is being considered. The monitoring of electromagnetic radiation of vehicles is carried out.

Highly efficient and stable white organic light emitting diode base on double recombination zones of phosphorescent blue/orange emitters.

Science.gov (United States)

Lee, Seok Jae; Koo, Ja Ryong; Lim, Dong Hwan; Park, Hye Rim; Kim, Young Kwan; Ha, Yunkyoung

2011-08-01

We demonstrated efficient and stable white phosphorescent organic light-emitting diodes (OLEDs) with double-emitting layers (D-EMLs), which were comprised of two emissive layers with a hole transport-type host of N,N'-dicarbazolyl-3,5-benzene (mCP) and a electron transport-type host of 2,2',2"-(1,3,5-benzenetryl)tris(1-phenyl)-1H-benzimidazol (TPBi) with blue/orange emitters, respectively. We fabricated two type white devices with single emitting layer (S-EML) and D-EML of orange emitter, maintaining double recombination zone of blue emitter. In addition, the device architecture was developed to confine excitons inside the D-EMLs and to manage triplet excitons by controlling the charge injection. As a result, light-emitting performances of white OLED with D-EMLs were improved and showed the steady CIE coordinates compared to that with S-EML of orange emitter, which demonstrated the maximum luminous efficiency and external quantum efficiency were 21.38 cd/A and 11.09%. It also showed the stable white emission with CIE(x,y) coordinates from (x = 0.36, y = 0.37) at 6 V to (x = 0.33, y = 0.38) at 12 V.

Contact light-emitting diodes based on vertical ZnO nanorods

Energy Technology Data Exchange (ETDEWEB)

Panin, G. N. [Dongguk University, Seoul (Korea, Republic of); Russian Academy of Sciences, Chernogolovka, Moscow district (Russian Federation); Cho, H. D.; Lee, S. W.; Kang, T. W. [Dongguk University, Seoul (Korea, Republic of)

2014-05-15

We report vertical contact light-emitting diodes (VCLEDs), that are based on heterojunctions formed by using the point contacts of n-ZnO nanorods (NRs) to the p-type semiconductor substrate and that are fabricated using a new approach to the formation of LEDs (Appl. Phys. Lett. 98, 093110 (2011)). A p-type GaN film grown on a sapphire substrate was used to form n-ZnO NRs/pGaN VCLEDs on a large area of about 4 cm{sup 2}. The VCLEDs emitted a pure blue electroluminescence with high efficiency. Electroluminescence at 470 nm, which is visible to the naked eye, started at small current of about 50 μA and is attributed to the good optical properties of the structurally perfect heterojunctions in the point contacts. The VCLED configuration allows the creation of ZnO/p-GaN nano-LEDs of high density and high-quality with a greatly reduced concentration of nonradiative defects in the active regions. The VCLEDs showed the high brightness of light required for active matrix displays and general solid-state lighting.

A Highly Reliable and Cost-Efficient Multi-Sensor System for Land Vehicle Positioning

Directory of Open Access Journals (Sweden)

Xu Li

2016-05-01

Full Text Available In this paper, we propose a novel positioning solution for land vehicles which is highly reliable and cost-efficient. The proposed positioning system fuses information from the MEMS-based reduced inertial sensor system (RISS which consists of one vertical gyroscope and two horizontal accelerometers, low-cost GPS, and supplementary sensors and sources. First, pitch and roll angle are accurately estimated based on a vehicle kinematic model. Meanwhile, the negative effect of the uncertain nonlinear drift of MEMS inertial sensors is eliminated by an H∞ filter. Further, a distributed-dual-H∞ filtering (DDHF mechanism is adopted to address the uncertain nonlinear drift of the MEMS-RISS and make full use of the supplementary sensors and sources. The DDHF is composed of a main H∞ filter (MHF and an auxiliary H∞ filter (AHF. Finally, a generalized regression neural network (GRNN module with good approximation capability is specially designed for the MEMS-RISS. A hybrid methodology which combines the GRNN module and the AHF is utilized to compensate for RISS position errors during GPS outages. To verify the effectiveness of the proposed solution, road-test experiments with various scenarios were performed. The experimental results illustrate that the proposed system can achieve accurate and reliable positioning for land vehicles.

A 3 W High-Voltage Single-Chip Green Light-Emitting Diode with Multiple-Cells Network

Directory of Open Access Journals (Sweden)

W. Wang

2015-01-01

Full Text Available A parallel and series network structure was introduced into the design of the high-voltage single-chip (HV-SC light-emitting diode to inhibit the effect of current crowding and to improve the yield. Using such a design, a 6.6×5 mm2 large area LED chip of 24 parallel stages was demonstrated with 3 W light output power (LOP at the current of 500 mA. The forward voltage was measured to be 83 V with the same current injection, corresponding to 3.5 V for a single stage. The LED chip’s average thermal resistance was identified to be 0.28 K/W by using infrared thermography analysis.

A study on model fidelity for model predictive control-based obstacle avoidance in high-speed autonomous ground vehicles

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2016-11-01

This paper investigates the level of model fidelity needed in order for a model predictive control (MPC)-based obstacle avoidance algorithm to be able to safely and quickly avoid obstacles even when the vehicle is close to its dynamic limits. The context of this work is large autonomous ground vehicles that manoeuvre at high speed within unknown, unstructured, flat environments and have significant vehicle dynamics-related constraints. Five different representations of vehicle dynamics models are considered: four variations of the two degrees-of-freedom (DoF) representation as lower fidelity models and a fourteen DoF representation with combined-slip Magic Formula tyre model as a higher fidelity model. It is concluded that the two DoF representation that accounts for tyre nonlinearities and longitudinal load transfer is necessary for the MPC-based obstacle avoidance algorithm in order to operate the vehicle at its limits within an environment that includes large obstacles. For less challenging environments, however, the two DoF representation with linear tyre model and constant axle loads is sufficient.

Electrical Vehicles Activities Around the World

DEFF Research Database (Denmark)

Schauer, Gerd; Garcia-Valle, Rodrigo

2013-01-01

engine. In the 1990s research and demonstrations intensified and built a good basis for actual development of electrical vehicles. Discussion of the results achieved and lessons learned from millions of kilometers of road testing is worthwhile but in addition to technological developments such as light...... which have jointly changed how mobility is viewed in recent years. We describe key points concerning such field testing and the renaissance in electric vehicles that occurred around 2010. We discuss progress in lithium battery technology for high power and high energy density, improvement in integrated...... business models, and the availability of high-performance electric vehicles have become key enablers of this new technology. In this regard, it is promising that electric vehicles will soon be a part of a green transport solution (green mobility) powered by renewable energy and a new smart electricity...

Vehicle lightweighting vs. electrification: Life cycle energy and GHG emissions results for diverse powertrain vehicles

International Nuclear Information System (INIS)

Lewis, Anne Marie; Kelly, Jarod C.; Keoleian, Gregory A.

2014-01-01

Highlights: • We modeled life cycle energy and greenhouse gas (GHG) emissions from diverse powertrain vehicles. • Lightweight versions of the vehicle models were compared against baseline models. • Maximum energy and GHG emissions occur with aluminum vs. advanced high strength steel. • Design harmonization method shows 0.2–0.3 kg of support required per 1 kg powertrain mass increase. - Abstract: This work assesses the potential of electrified vehicles and mass reduction to reduce life cycle energy and greenhouse gas (GHG) emissions. Life cycle assessment (LCA) is used to account for processes upstream and downstream of the vehicle operation, thereby incorporating regional variation of energy and GHG emissions due to electricity production and distinct energy and GHG emissions due to conventional and lightweight materials. Design harmonization methods developed in previous work are applied to create baseline and lightweight vehicle models of an internal combustion vehicle (ICV), hybrid electric vehicle (HEV) and plug-in hybrid electric vehicle (PHEV). Thus, each vehicle is designed to be functionally equivalent and incorporate the structural support required for heavier powertrains. Lightweight vehicles are designed using body-in-white (BIW) mass reduction scenarios with aluminum and advanced/high strength steel (A/HSS). For the mass reduction scenarios considered in this work, results indicate that the greatest life cycle energy and GHG emissions reductions occur when steel is replaced by aluminum. However, since A/HSS requires less energy to produce as compared to aluminum, the energy and GHG reductions per unit mass removed is greatest for A/HSS. Results of the design harmonization modeling method show that 0.2–0.3 kg of structural support is required per unit increase in powertrain mass, thus extending previous methods

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

International Nuclear Information System (INIS)

Baek, H I; Lee, C H

2008-01-01

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

Exporting automatic vehicle SNM monitoring technology

International Nuclear Information System (INIS)

York, R.L.; Fehlau, P.E.; Close, D.A.

1995-01-01

Controlling the transportation of nuclear materials is still one of the most effective nuclear proliferation barriers. The recent increase of global nuclear material proliferation has expanded the application of vehicle monitor technology to prevent the diversion of special nuclear material across international borders. To satisfy this new application, a high-sensitivity vehicle monitor, which is easy to install and capable of operating in high-traffic areas, is required. A study of a new detector configuration for a drive-through vehicle monitor is discussed in this paper

Efficient and color-saturated inverted bottom-emitting organic light-emitting devices with a semi-transparent metal-assisted electron injection layer

Energy Technology Data Exchange (ETDEWEB)

Ho, Meng-Huan, E-mail: kinneas.ac94g@nctu.edu.t [Department of Applied Chemistry, National Chiao Tung University, 210 R, CPT Building, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan (China); Wu, Chang-Yen [Department of Photonics, National Chiao Tung University, Hsinchu 300, Taiwan (China); Chen, Teng-Ming [Department of Applied Chemistry, National Chiao Tung University, 210 R, CPT Building, 1001 Ta Hsueh Road, Hsinchu 300, Taiwan (China); Chen, Chin H. [Display Institute, Microelectronics and Information Systems Research Center, National Chiao Tung University, Hsinchu 300, Taiwan (China)

2011-01-15

We report the development of highly efficient and color-saturated green fluorescent 10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H, 11H-benzo[l]pyrano-[6,7,8-ij]quinolizin-11-one dye-doped inverted bottom-emitting organic light-emitting diode (IBOLED). This was enabled by the insertion of a silver (Ag) based semi-transparent metal-assisted electron injection layer between the ITO cathode and n-doped electron transporting layer. This IBOLED with ITO/Ag bilayer cathode with its synergistic microcavity effect achieved luminous efficiencies of 20.7 cd/A and 12.4 lm/W and a saturated CIE{sub x,y} of (0.22, 0.72) at 20 mA/cm{sup 2}, which are twice better than those of the conventional OLED and have over 60% improvement on IBOLED without ITO/Ag bilayer cathode.

High performance tunnel injection InGaN/GaN quantum Dot light emitting diodes emitting in the green (λ=495nm)

KAUST Repository

Zhang, Meng

2011-05-01

InGaN/GaN self-organized quantum dots with density of (2-5)×10 10 cm-2, internal quantum efficiency of 32% and a reduced recombination lifetime of 0.6 ns were grown by plasma assisted molecular beam epitaxy. The photoluminescence spectra of the dots peak at 495 nm at 300 K. The characteristics of tunnel injection InGaN/GaN quantum dot light emitting diodes are presented. The current density at maximum efficiency is 90.2 A/cm 2, which is superior to equivalent multiquantum well devices. © 2010 Elsevier B.V. All rights reserved.

Overestimation of on-road air quality surveying data measured with a mobile laboratory caused by exhaust plumes of a vehicle ahead in dense traffic areas.

Science.gov (United States)

Woo, Sang-Hee; Kwak, Kyung-Hwan; Bae, Gwi-Nam; Kim, Kyung Hwan; Kim, Chang Hyeok; Yook, Se-Jin; Jeon, Sangzin; Kwon, Sangil; Kim, Jeongsoo; Lee, Seung-Bok

2016-11-01

The unintended influence of exhaust plumes emitted from a vehicle ahead to on-road air quality surveying data measured with a mobile laboratory (ML) at 20-40 km h -1 in dense traffic areas was investigated by experiment and life-sized computational fluidic dynamics (CFD) simulation. The ML equipped with variable sampling inlets of five columns by four rows was used to measure the spatial distribution of CO 2 and NO x concentrations when following 5-20 m behind a sport utility vehicle (SUV) as an emitter vehicle equipped with a portable emission monitoring system (PEMS). The PEMS measured exhaust gases at the tailpipe for input data of the CFD simulations. After the CFD method was verified with experimental results of the SUV, dispersion of exhaust plumes emitted from a bus and a sedan was numerically analyzed. More dilution of the exhaust plume was observed at higher vehicle speeds, probably because of eddy diffusion that was proportional to turbulent kinetic energy and vehicle speed. The CO 2 and NO x concentrations behind the emitter vehicle showed less overestimation as both the distance between the two vehicles and their background concentrations increased. If the height of the ML inlet is lower than 2 m and the ML travels within 20 m behind a SUV and a sedan ahead at 20 km h -1 , the overestimation should be considered by as much as 200 ppb in NO x and 80 ppm in CO 2 . Following a bus should be avoided if possible, because effect of exhaust plumes from a bus ahead could not be negligible even when the distance between the bus and the ML with the inlet height of 2 m, was more than 40 m. Recommendations are provided to avoid the unintended influence of exhaust plumes from vehicles ahead of the ML during on-road measurement in urban dense traffic conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Control of emitted light polarization in a 1310 nm dilute nitride spin-vertical cavity surface emitting laser subject to circularly polarized optical injection

Energy Technology Data Exchange (ETDEWEB)

Alharthi, S. S., E-mail: ssmalh@essex.ac.uk; Hurtado, A.; Al Seyab, R. K.; Henning, I. D.; Adams, M. J. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Korpijarvi, V.-M.; Guina, M. [Optoelectronics Research Centre (ORC), Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland)

2014-11-03

We experimentally demonstrate the control of the light polarization emitted by a 1310 nm dilute nitride spin-Vertical Cavity Surface Emitting Laser (VCSEL) at room temperature. This is achieved by means of a combination of polarized optical pumping and polarized optical injection. Without external injection, the polarization of the optical pump controls that of the spin-VCSEL. However, the addition of the externally injected signal polarized with either left- (LCP) or right-circular polarization (RCP) is able to control the polarization of the spin-VCSEL switching it at will to left- or right-circular polarization. A numerical model has been developed showing a very high degree of agreement with the experimental findings.

Red organic light-emitting diodes based on wide band gap emitting material as the host utilizing two-step energy transfer

International Nuclear Information System (INIS)

Haq Khizarul; Shanpeng Liu; Khan, M A; Jiang, X Y; Zhang, Z L; Zhu, W Q

2008-01-01

We demonstrated efficient red organic light-emitting diodes based on a host emitting system of 9,10-di(2-naphthyl)anthracene (ADN) co-doped with 4-(dicyano-methylene)-2-t-butyle-6- (1,1,7,7-tetramethyl-julolidyl-9-enyl)-4H-pyran (DCJTB) as a red dopant and 2,3,6,7- tetrahydro-1,1,7,7-tetramethyl-1H,5H,1 1H-10(2-benzothiazolyl)-quinolizine-[9,9a,1gh] coumarin (C545T) as an assistant dopant. The typical device structure was glass substrate/ITO/4,4',4''-tris(N-3-methylphenyl-N-phenylamino) triphenylamine(m-MTDATA)/N,N'-bis-(naphthalene-1-yl)-N,N'-diphenylbenzidine (NPB)/[ADN: DCJTB: C545T/Alq 3 /LiF/Al]. It was found that C545T dopant did not emit by itself but did assist the energy transfer from the host (ADN) to the red emitting dopant. The red OLEDs realized by this approach not only enhanced the emission color, but also significantly improved the EL efficiency. The EL efficiency reached 3.5 cd A −1 at a current density of 20 mA cm −2 , which is enhanced by three times compared with devices where the emissive layer is composed of the DCJTB doped ADN. The saturated red emission was obtained with CIE coordinates (x = 0.618, y = 0.373) at 621 nm, and the device driving voltage is decreased as much as 38%. We attribute these improvements to the assistant dopant (C545T), which leads to the more efficient energy transfer from ADN to DCJTB. These results indicate that the co-doped system is a promising method for obtaining high-efficiency red OLEDs

Appending High-Resolution Elevation Data to GPS Speed Traces for Vehicle Energy Modeling and Simulation

Energy Technology Data Exchange (ETDEWEB)

Wood, E.; Burton, E.; Duran, A.; Gonder, J.