WorldWideScience

Sample records for extracting light filth

  1. Extraction of light filth from barley, oatmeal, and mixed dry infant cereals: collaborative study.

    Science.gov (United States)

    Dent, R G

    1980-03-01

    A new method has been developed for the extraction of light filth from oatmeal, barley, and mixed dry infant cereals which involves HCl digestion followed by wet sieving. The residue is defatted in a paper cup, using isopropanol, and transferred to a 2 L Wildman trap flask with 40% isopropanol. Filth elements are extracted with light mineral oil. Interlaboratory studies resulted in 92 and 86% average recoveries of rodent hairs and insect fragments, respectively. The proposed method has been adopted as official first action.

  2. Foreign matter contaminating ethanolic extract of propolis: a filth-test survey comparing products from small beekeeping farms and industrial producers.

    Science.gov (United States)

    Canale, Angelo; Cosci, Francesca; Canovai, Roberto; Giannotti, Paolo; Benelli, Giovanni

    2014-01-01

    Propolis is a resinous material collected by honeybees from the exudates and buds of plants. It has been widely used as a remedy by humans since ancient times, as well as for dietary supplements and cosmetics. European legislation recently focused on the quality and hygiene standards of foods, including beehive products, and extensive efforts have been made to avoid the presence of chemical contaminants, whilst in contrast few studies have investigated the magnitude of contamination by physical ones. We conducted a filth-test survey to evaluate the contamination of ethanolic extract of propolis by foreign materials. We also compared the abundance of contaminants in propolis extracts currently marketed by small beekeepers and industrial producers. We found different foreign materials in the ethanol extract of propolis. Contaminants differed in abundance, with a higher number of carbon particles (small beekeepers: 2.70 ± 0.63; industrial producers: 1.25 ± 0.49; mean (n/30 ml) ± SE) and other inorganic fragments (small beekeepers: 3.50 ± 0.31; industrial producers: 3.88 ± 1.11) than arthropod fragments (small beekeepers: 0.30 ± 0.21; industrial producers: 0.38 ± 0.26) and mammal hairs (small beekeepers: 0.10 ± 0.10; industrial producers: 0.38 ± 0.26). No differences in the abundance of foreign matter between propolis from small beekeepers and industrial producers were found, allowing us to point out an increased awareness by small producers of issues inherent in hygiene management. Contamination of propolis extracts by animal body parts, such as insect fragments, mites and rodent hairs, indicates poor management of hygiene in the production process and low effectiveness of the filtration phase. Animal-borne contaminants can act as pathogen vectors as well as introducing dangerous allergens when ingested or applied to human skin. The filth-test applied to ethanolic propolis extract quality control can be considered a promising tool, also for small beekeeper

  3. Assessment of hygienic conditions of ground pepper (Piper nigrum L.) on the market in Sao Paulo City, by means of two methodologies for detecting the light filth

    Science.gov (United States)

    Pepper should to be collected, processed, and packed under optimum conditions to avoid the presence of foreign matter. The hygienic conditions of ground pepper marketted in São Paulo city were assessed in determining the presence of foreign matter by means of two extraction methodologies. This study...

  4. Organic light emitting diode with light extracting electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Abhinav; Buhay, Harry

    2017-04-18

    An organic light emitting diode (10) includes a substrate (20), a first electrode (12), an emissive active stack (14), and a second electrode (18). At least one of the first and second electrodes (12, 18) is a light extracting electrode (26) having a metallic layer (28). The metallic layer (28) includes light scattering features (29) on and/or in the metallic layer (28). The light extracting features (29) increase light extraction from the organic light emitting diode (10).

  5. Organic light emitting diode with light extracting layer

    Science.gov (United States)

    Lu, Songwei

    2016-06-14

    A light extraction substrate includes a glass substrate having a first surface and a second surface. A light extraction layer is formed on at least one of the surfaces. The light extraction layer is a coating, such as a silicon-containing coating, incorporating nanoparticles.

  6. Light extraction block with curved surface

    Science.gov (United States)

    Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

    2016-03-22

    Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

  7. Organic electroluminescent devices having improved light extraction

    Science.gov (United States)

    Shiang, Joseph John

    2007-07-17

    Organic electroluminescent devices having improved light extraction include a light-scattering medium disposed adjacent thereto. The light-scattering medium has a light scattering anisotropy parameter g in the range from greater than zero to about 0.99, and a scatterance parameter S less than about 0.22 or greater than about 3.

  8. Survey of Italian honeys for the presence of foreign matter using the filth test.

    Science.gov (United States)

    Canale, Angelo; Canovai, Roberto; Cosci, Francesca; Giannotti, Paolo; Benelli, Giovanni

    2014-01-01

    Honey is an ancient food that has always been considered a natural and healthy product, free of contaminants. However, it can contain toxic substances, such as antibiotics, pesticides and heavy metals, as well as foreign matter (e.g. arthropod body parts and microbial contaminants), working as allergens and vectors of human pathogens. In this study we used the filth test to evaluate the abundance of foreign matter in 70 Italian honeys, including Castanea sativa, Robinia pseudoacacia and multi-floral honeys, the latter both from small beekeeping farms and industrial producers. The abundance of different foreign matter varied in honeys, with a higher number of carbon particles and other inorganic fragments, followed by fragments of animal origin. This latter included insects (Diptera Brachycera larvae and Strepsiptera), their cuticular fragments (mainly Coleoptera, Hymenoptera and Lepidoptera), mites (mainly Glycyphagidae, Acaridae and Tarsonemidae) and mammal hairs. No differences were recorded in the abundance of foreign matter among different kinds of honey, as well as between honeys from small and large-sized producers. Foreign matter found in honey provided functional information to evaluate honey quality standards in apiary, honey extraction and packaging phases. Overall, the filth test method applied to honey quality control can be considered an excellent tool, also for small beekeeping farms, since it allows rapid and frequent quality checking of the production process. This method is cheap, requires minimal instrumental equipment and results can be interpreted quickly.

  9. The Mechanical Analysis and Experimental Study of Shock Wave Effect of Electrical Discharge under Water In Filth Cleaning

    Institute of Scientific and Technical Information of China (English)

    Deng Qilin; Zhang Lei; Zhou Jinjin

    2004-01-01

    Filth adhering to metal pipes can be cleaned by shock wave generated by electrical discharge under water. The mechanism of shock wave effect of electrical discharge under water on filth cleaning is analyzed by building a mechanical model. A metal pipe coated with cement to simulate real filth is cleaned by using electrical discharge under water. The experimental results confirm the mechanical analysis and also show the technology of electrical discharge under water is an very effective method for filth cleaning.

  10. Batch Extractive Distillation with Light Entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol/water (minimum boiling azeotrope) with methanol, water/ethylene diamine (maximum boiling azeotro...

  11. Batch extractive distillation with light entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Lelkes, Zoltan; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol / water (minimum boiling azeotrope) with methanol, water / ethylene diamine (maximum boiling azeotrope...

  12. Oviposition deterrence and immature survival if filth flies (Diptera: Muscidae) when exposed to commercial fungal products

    Science.gov (United States)

    Filth flies are pests of livestock, and can transmit pathogens that cause disease to animals and their caretakers. Studies have shown successful infection of adult filth flies following exposure to different strains and formulations of entomopathogenic fungi. This study aimed to examine the subletha...

  13. Device structure for OLED light device having multi element light extraction and luminescence conversion layer

    Science.gov (United States)

    Antoniadis; Homer , Krummacher; Benjamin Claus

    2008-01-22

    An apparatus such as a light source has a multi-element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

  14. OLED lighting devices having multi element light extraction and luminescence conversion layer

    Science.gov (United States)

    Krummacher, Benjamin Claus; Antoniadis, Homer

    2010-11-16

    An apparatus such as a light source has a multi element light extraction and luminescence conversion layer disposed over a transparent layer of the light source and on the exterior of said light source. The multi-element light extraction and luminescence conversion layer includes a plurality of light extraction elements and a plurality of luminescence conversion elements. The light extraction elements diffuses the light from the light source while luminescence conversion elements absorbs a first spectrum of light from said light source and emits a second spectrum of light.

  15. White Light Emission from Vegetable Extracts

    OpenAIRE

    Vikram Singh; Ashok K. Mishra

    2015-01-01

    A mixture of extracts from two common vegetables, red pomegranate and turmeric, when photoexcited at 380 nm, produced almost pure white light emission (WLE) with Commission Internationale d’Eclairage (CIE) chromaticity index (0.35, 0.33) in acidic ethanol. It was also possible to obtain WLE in polyvinyl alcohol film (0.32, 0.25), and in gelatin gel (0.26, 0.33) using the same extract mixture. The colour temperature of the WLE was conveniently tunable by simply adjusting the concentrations of ...

  16. White Light Emission from Vegetable Extracts

    Science.gov (United States)

    Singh, Vikram; Mishra, Ashok K.

    2015-06-01

    A mixture of extracts from two common vegetables, red pomegranate and turmeric, when photoexcited at 380 nm, produced almost pure white light emission (WLE) with Commission Internationale d’Eclairage (CIE) chromaticity index (0.35, 0.33) in acidic ethanol. It was also possible to obtain WLE in polyvinyl alcohol film (0.32, 0.25), and in gelatin gel (0.26, 0.33) using the same extract mixture. The colour temperature of the WLE was conveniently tunable by simply adjusting the concentrations of the component emitters. The primary emitting pigments responsible for contributing to WLE were polyphenols and anthocyanins from pomegranate, and curcumin from turmeric. It was observed that a cascade of Forster resonance energy transfer involving polyphenolics, curcumin and anthocyanins played a crucial role in obtaining a CIE index close to pure white light. The optimized methods of extraction of the two primary emitting pigments from their corresponding plant sources are simple, cheap and fairly green.

  17. 75 FR 20615 - Risk Profile: Pathogens and Filth in Spices: Request for Comments and for Scientific Data and...

    Science.gov (United States)

    2010-04-20

    ... frequency and levels of pathogen and/or filth contamination of spices throughout the food supply chain (e.g... Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061... HUMAN SERVICES Food and Drug Administration Risk Profile: Pathogens and Filth in Spices: Request...

  18. Commercial Light Water Reactor Tritium Extraction Facility

    Energy Technology Data Exchange (ETDEWEB)

    McHood, M D

    2000-10-12

    A geotechnical investigation program has been completed for the Commercial Light Water Reactor - Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site (SRS). The program consisted of reviewing previous geotechnical and geologic data and reports, performing subsurface field exploration, field and laboratory testing, and geologic and engineering analyses. The purpose of this investigation was to characterize the subsurface conditions for the CLWR-TEF in terms of subsurface stratigraphy and engineering properties for design and to perform selected engineering analyses. The objectives of the evaluation were to establish site-specific geologic conditions, obtain representative engineering properties of the subsurface and potential fill materials, evaluate the lateral and vertical extent of any soft zones encountered, and perform engineering analyses for slope stability, bearing capacity and settlement, and liquefaction potential. In addition, provide general recommendations for construction and earthwork.

  19. Light extraction from organic light-emitting diodes for lighting applications by sand-blasting substrates.

    Science.gov (United States)

    Chen, Shuming; Kwok, Hoi Sing

    2010-01-04

    Light extraction from organic light-emitting diodes (OLEDs) by scattering the light is one of the effective methods for large-area lighting applications. In this paper, we present a very simple and cost-effective method to rough the substrates and hence to scatter the light. By simply sand-blasting the edges and back-side surface of the glass substrates, a 20% improvement of forward efficiency has been demonstrated. Moreover, due to scattering effect, a constant color over all viewing angles and uniform light pattern with Lambertian distribution has been obtained. This simple and cost-effective method may be suitable for mass production of large-area OLEDs for lighting applications.

  20. Dielectric nanoparticles for the enhancement of OLED light extraction efficiency

    Science.gov (United States)

    Mann, Vidhi; Rastogi, Vipul

    2017-03-01

    This work reports the use of dielectric nanoparticles placed at glass substrate in the improvement of light extraction efficiency of organic light emitting diode (OLED). The nanoparticles will act as scattering medium for the light trapped in the waveguiding modes of the device. The scattering efficiency of dielectric nanoparticles has been calculated by Mie Theory. The finite difference time domain (FDTD) analysis and simulation estimate the effect of dielectric nanoparticles on the light extraction efficiency of OLED. The efficiency depends upon the diameter, interparticle separation and refractive index of dielectric nanoparticles. It is shown that the dielectric nanoparticles layer can enhance the light extraction efficiency by a factor of 1.7.

  1. High extraction efficiency ultraviolet light-emitting diode

    Science.gov (United States)

    Wierer, Jonathan; Montano, Ines; Allerman, Andrew A.

    2015-11-24

    Ultraviolet light-emitting diodes with tailored AlGaN quantum wells can achieve high extraction efficiency. For efficient bottom light extraction, parallel polarized light is preferred, because it propagates predominately perpendicular to the QW plane and into the typical and more efficient light escape cones. This is favored over perpendicular polarized light that propagates along the QW plane which requires multiple, lossy bounces before extraction. The thickness and carrier density of AlGaN QW layers have a strong influence on the valence subband structure, and the resulting optical polarization and light extraction of ultraviolet light-emitting diodes. At Al>0.3, thinner QW layers (efficiently inject carriers in all the QWs, are preferred.

  2. 78 FR 66010 - Draft Risk Profile on Pathogens and Filth in Spices; Availability

    Science.gov (United States)

    2013-11-04

    ... contamination of spices throughout the food supply chain (e.g., on the farm, at primary processing/manufacturing... Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061... HUMAN SERVICES Food and Drug Administration Draft Risk Profile on Pathogens and Filth in...

  3. Light Extraction Efficiency in OLED with Sub-wavelength Structures

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By simulating with finite-difference time-domain(FDTD) method, it is proved that two kinds of new photonic crystal slab(PCS) structures could enhance the light extraction efficiency of OLED. By comparing the results, the most effective PCS structure with maximum light extraction efficiency(Er=1.99) is got. The optimized geometric parameters and optimized performance parameters of the PCS structures are also obtained.

  4. Soft lithography microlens fabrication and array for enhanced light extraction from organic light emitting diodes (OLEDs)

    Science.gov (United States)

    Leung, Wai Y.; Park, Joong-Mok; Gan, Zhengqing; Constant, Kristen P.; Shinar, Joseph; Shinar, Ruth; ho, Kai-Ming

    2014-06-03

    Provided are microlens arrays for use on the substrate of OLEDs to extract more light that is trapped in waveguided modes inside the devices and methods of manufacturing same. Light extraction with microlens arrays is not limited to the light emitting area, but is also efficient in extracting light from the whole microlens patterned area where waveguiding occurs. Large microlens array, compared to the size of the light emitting area, extract more light and result in over 100% enhancement. Such a microlens array is not limited to (O)LEDs of specific emission, configuration, pixel size, or pixel shape. It is suitable for all colors, including white, for microcavity OLEDs, and OLEDs fabricated directly on the (modified) microlens array.

  5. Enhanced Light Extraction from a GaN-based Light Emitting Diode with Triangle Grating Structure

    Directory of Open Access Journals (Sweden)

    Li Cheng

    2013-05-01

    Full Text Available We propose a simple method to improve the light extraction in GaN based light emitting diode. Conventional light emitting diode has an extraction limitation due to the total internal reflection which occurs at the interface between GaN and air. By using periodic grating etched at the GaN layer, we can couple more emitting light out of the active layer. Tapering the grating structure would facilitate the impedance matching between GaN light emitting diode and air, which can enhance broadband light extraction. We use finite difference time domain method to numerically find the best tapering grating structure. The numerical experiment demonstrate an enhance factor 4 of our proposed structure compared with the conventional one over broad band specctrum.

  6. High light extraction efficiency in bulk-GaN based volumetric violet light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    David, Aurelien, E-mail: adavid@soraa.com; Hurni, Christophe A.; Aldaz, Rafael I.; Cich, Michael J.; Ellis, Bryan; Huang, Kevin; Steranka, Frank M.; Krames, Michael R. [Soraa Inc., 6500 Kaiser Dr., Fremont, California 94555 (United States)

    2014-12-08

    We report on the light extraction efficiency of III-Nitride violet light-emitting diodes with a volumetric flip-chip architecture. We introduce an accurate optical model to account for light extraction. We fabricate a series of devices with varying optical configurations and fit their measured performance with our model. We show the importance of second-order optical effects like photon recycling and residual surface roughness to account for data. We conclude that our devices reach an extraction efficiency of 89%.

  7. Oviposition Deterrence and Immature Survival of Filth Flies (Diptera: Muscidae) When Exposed to Commercial Fungal Products

    Science.gov (United States)

    Machtinger, E.T.; Weeks, E.N.I.; Geden, C. J.

    2016-01-01

    Filth flies are pests of livestock, and can transmit pathogens that cause disease to animals and their caretakers. Studies have shown successful infection of adult filth flies following exposure to different strains and formulations of entomopathogenic fungi. This study aimed to examine the effects of commercial formulations of Beauveria bassiana (Balsamo) (Moniliales: Moniliaceae) (i.e., BotaniGard ES, Mycotrol O, balEnce), and Metarhizium brunneum (Metsch.) (Ascomycota: Hypocreales) (i.e., Met52 EC), on filth fly oviposition and immature fly survival after exposure. House flies, Musca domestica L., laid significantly fewer eggs on Met52 EC-treated surfaces than on surfaces treated with all other products and the control. Similar numbers of eggs were laid on surfaces treated with all B. bassiana products, but egg production was half of the control. Stable flies, Stomoxys calcitrans (L.), laid the fewest eggs on Met52 EC- and Mycotrol O-treated surfaces. This species did not distinguish between the remaining products and the control. In a second experiment, house fly eggs were placed on treated cloths so that hatched larvae contacted the treatment prior to development. Met52 EC had the greatest effect on immature survival with a significant reduction in recovered pupae at the medium and high doses of fungi. Overall, Met52 EC, containing M. brunneum, had the greatest effect on house fly and stable fly oviposition deterrence and immature development of house flies. Management implications are discussed. PMID:27302955

  8. High Extraction Phosphors for Solid State Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Summers, Chris [Phosphortech Corporation, Kennesaw, GA (United States); Menkara, Hisham [Phosphortech Corporation, Kennesaw, GA (United States); Wagner, Brent [Phosphortech Corporation, Kennesaw, GA (United States)

    2011-09-01

    We have developed high-index, high efficiency bulk luminescent materials and novel nano-sized phosphors for improved solid-state white LED lamps. These advances can potentially contribute to reducing the loss in luminous efficiencies due to scattering, re-absorption, and thermal quenching. The bulk and nanostructured luminescent materials investigated are index matched to GaN and have broad and size-tunable absorption bands, size and impurity tuned emission bands, size-driven elimination of scattering effects, and a separation between absorption and emission bands. These innovations were accomplished through the use of novel synthesis techniques suitable for high volume production for LED lamp applications. The program produced a full-color set of high quantum yield phosphors with high chemical stability. In the bulk phosphor study, the ZnSeS:Cu,Ag phosphor was optimized to achieve >91% efficiency using erbium (Er) and other activators as sensitizers. Detailed analysis of temperature quenching effects on a large number of ZnSeS:Cu,Ag,X and strontium- and calcium-thiogallate phosphors lead to a breakthrough in the understanding of the anti-quenching behavior and a physical bandgap model was developed of this phenomena. In a follow up to this study, optimized phosphor blends for high efficiency and color performance were developed and demonstrated a 2-component phosphor system with good white chromaticity, color temperature, and high color rendering. By extending the protocols of quantum dot synthesis, large nanocrystals, greater than 20 nm in diameter were synthesized and exhibited bulk-like behavior and blue light absorption. The optimization of ZnSe:Mn nanophosphors achieved ~85% QE The limitations of core-shell nanocrystal systems were addressed by investigating alternative deltadoped structures. To address the manufacturability of these systems, a one-pot manufacturing protocol was developed for ZnSe:Mn nanophosphors. To enhance the stability of these material

  9. Phase extraction from fringe pattern via light propagation.

    Science.gov (United States)

    Zhu, Wenhua; Chen, Lei; Zheng, Donghui; Zhang, Rui; Han, Zhigang

    2017-01-10

    A phase demodulation method via light propagation is proposed, where one or two fringe patterns are viewed as the superposition of complex amplitudes, and then the phase is reconstructed by separating the light field via light propagation. Simulation and experimental results indicated that the proposed method can extract the phase from a single shot effectively, thereby realizing dynamic phase retrieval. In addition, the accuracy of phase reconstruction can be improved by adding another fringe pattern with an unknown phase shift. The carrier requirement is relatively low, and, thus, the proposed method can be applied to the measurements with an environment disturbance, an inaccurate phase shift, and the requirement of a high speed capture.

  10. Light extraction enhancement from organic light-emitting diodes with randomly scattered surface fixture

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Dong-Ying; Shi, Xiao-Bo; Gao, Chun-Hong; Cai, Shi-Duan; Jin, Yue; Liao, Liang-Sheng, E-mail: lsliao@suda.edu.cn

    2014-09-30

    Graphical abstract: - Highlights: • A combination of scattering layer and roughened substrate is used for light extraction from OLEDs. • The scattering layer is readily achieved by spin-coating the TiO{sub 2} sol. • The enhancement relying scattering depends on the size of TiO{sub 2} nano particles. • With the light extraction techniques the uniform emission is achieved. - Abstract: A combination of a scattering medium layer and a roughened substrate was proposed to enhance the light extraction efficiency of organic light-emitting diodes (OLEDs). Comparing with a reference OLED without any scattering layer, 65% improvement in the forward emission has been achieved with a scattering layer formed on an intentionally roughened external substrate surface of the OLED by spin-coating a sol–gel fabricated matrix containing well dispersed titania (TiO{sub 2}) particles. Such a combination method not only demonstrated efficient extraction of the light trapped in the glass substrate but also achieved homogenous emission from the OLED panel. The proposed technique, convenient and inexpensive, is believed to be suitable for the large area OLED production in lighting applications.

  11. Light extraction efficiency enhancement for fluorescent SiC based white light-emitting diodes

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

    fluorescent Boron-Nitrogen co-doped 6H SiC is optimized in terms of source material, growth condition, dopant concentration, and carrier lifetime by using photoluminescence, pump-probe spectroscopy etc. The internal quantum efficiency is measured and the methods to increase the efficiency have been explored......Fluorescent SiC based white light-emitting diodes(LEDs) light source, as an innovative energy-efficient light source, would even have longer lifetime, better light quality and eliminated blue-tone effect, compared to the current phosphor based white LED light source. In this paper, the yellow....... At a device level, the focus is on improving the light extraction efficiency due to the rather high refractive index of SiC by nanostructuring the surface of SiC. Both periodic nanostructures made by e-beam lithography and nanosphere lithography and random nanostructures made by self-assembled Au nanosphere...

  12. Light extraction enhancement of organic light-emitting diodes using aluminum zinc oxide embedded anodes.

    Science.gov (United States)

    Hsu, Ching-Ming; Lin, Bo-Ting; Zeng, Yin-Xing; Lin, Wei-Ming; Wu, Wen-Tuan

    2014-12-15

    Aluminum zinc oxide (AZO) has been embedded onto indium tin oxide (ITO) anode to enhance the light extraction from an organic light-emitting diode (OLED). The embedded AZO provides deflection and scattering interfaces on the newly generated AZO/organics and AZO/ITO interfaces rather than the conventional ITO/organic interface. The current efficiency of AZO embedded OLEDs was enhanced by up to 64%, attributed to the improved light extraction by additionally created reflection and scattering of emitted light on the AZO/ITO interfaces which was roughed in AZO embedding process. The current efficiency was found to increase with the increasing AZO embedded area ratio, but limited by the accompanying increases in haze and electrical resistance of the AZO embedded ITO film.

  13. A Light Scattering Layer for Internal Light Extraction of Organic Light-Emitting Diodes Based on Silver Nanowires.

    Science.gov (United States)

    Lee, Keunsoo; Shin, Jin-Wook; Park, Jun-Hwan; Lee, Jonghee; Joo, Chul Woong; Lee, Jeong-Ik; Cho, Doo-Hee; Lim, Jong Tae; Oh, Min-Cheol; Ju, Byeong-Kwon; Moon, Jaehyun

    2016-07-13

    We propose and fabricate a random light scattering layer for light extraction in organic light-emitting diodes (OLEDs) with silver nanodots, which were obtained by melting silver nanowires. The OLED with the light scattering layer as an internal light extraction structure was enhanced by 49.1% for the integrated external quantum efficiency (EQE). When a wrinkle structure is simultaneously used for an external light extraction structure, the total enhancement of the integrated EQE was 65.3%. The EQE is maximized to 65.3% at a current level of 2.0 mA/cm(2). By applying an internal light scattering layer and wrinkle structure to an OLED, the variance in the emission spectra was negligible over a broad viewing angle. Power mode analyses with finite difference time domain (FDTD) simulations revealed that the use of a scattering layer effectively reduced the waveguiding mode while introducing non-negligible absorption. Our method offers an effective yet simple approach to achieve both efficiency enhancement and spectral stability for a wide range of OLED applications.

  14. Surface Patterning of Ceramic Phosphor Plate for Light Extraction

    Science.gov (United States)

    Mao, An

    Light-Emitting Diodes (LEDs) are expected to replace traditional lighting sources in the near future due to their energy-efficiency, optical design flexibility and good reliability over traditional lighting sources. III-V nitride blue LEDs with powdered phosphors have been used commercially to get white emission. However, due to scattering losses, thermal issues as well as the surface reactivity with common encapsulants, LEDs fabricated with powdered phosphors have limitations in achieving high luminous efficacy, high chromatic stability and good color-rendering properties. Solid, non-scattering phosphors could avoid many of these limitations, but issues of light extraction and coupling of excitation radiation to the phosphor require development to insure efficient operation. Photonic crystal structures fabricated into or on non-scattering phosphors can be used to address these challenges. In this thesis, a lift-off process with bilayer resist system is developed to create nanopatterns. A photonic crystal structure is fabricated by low cost molecular transfer lithography (MxL) with bi-layer resist system on non-scattering phosphor plate used for white emission to increase the extraction efficiency. In Chapter 1, some basic background concepts which appear frequently in this thesis are introduced. These concepts include the Stokes shift and backscattering phenomenon for powder phosphors as well as non-scattering phosphors. In Chapter 2, a non-scattering single crystal phosphor with a patterned surface is proposed to replace the powdered phosphors used for color converted LEDs. A non-scattering phosphor YAG:Ce ceramic phosphor plate (CPP) patterned with TiO2 photonic crystal structure is selected for convenience to demonstrate the concept. The physical origin of light extraction of the proposed structure is discussed. The simulation principles and results are discussed in this chapter to find the optimized photonic crystal structure for light extraction. In Chapter 3

  15. Filth fly transmission of Escherichia coli O157:H7 and Salmonella enterica to lettuce, Lactuca sativa

    Science.gov (United States)

    Filth flies have been implicated in the dispersal of human disease pathogens; however, fly transmission parameters of human pathogens to plants are largely undescribed. The capacity of the black blow fly, Phormia regina, to acquire and subsequently release bacteria onto baby lettuce leaves was comp...

  16. Evaluation of imidacloprid-treated traps as an attract and kill system for filth flies during contingency operations.

    Science.gov (United States)

    Field trials were conducted to evaluate if filth fly trap efficacy was increased by application of an insecticide to a trap’s exterior. Four Fly Terminator® Pro traps baited with Fly Terminator® attractant were suspended on PVC pipe framing at a Florida waste transfer site. Exterior surfaces of tw...

  17. 78 FR 76628 - Draft Risk Profile on Pathogens and Filth in Spices: Availability; Extension of Comment Period

    Science.gov (United States)

    2013-12-18

    ... appeared in the Federal Register of November 4, 2013 (78 FR 66010). In the notice, FDA requested comments...-2927. SUPPLEMENTARY INFORMATION: I. Background In the Federal Register of November 4, 2013 (78 FR 66010... HUMAN SERVICES Food and Drug Administration Draft Risk Profile on Pathogens and Filth in...

  18. Mosquito and filth fly control in desert and temperate environments with a synergized pesticide mister and barrier treatment

    Science.gov (United States)

    U.S. military operations face significant negative impacts on mission readiness from disease-vector and nuisance filth flies, mosquitoes, and sand flies. Through the Deployed War Fighter Protection Program (DWFP) we previously developed small scale 9 ft by 3 ft pesticide-treated perimeters enhanced ...

  19. Efficient Light Extraction from Organic Light-Emitting Diodes Using Plasmonic Scattering Layers

    Energy Technology Data Exchange (ETDEWEB)

    Rothberg, Lewis

    2012-11-30

    Our project addressed the DOE MYPP 2020 goal to improve light extraction from organic light-emitting diodes (OLEDs) to 75% (Core task 6.3). As noted in the 2010 MYPP, “the greatest opportunity for improvement is in the extraction of light from [OLED] panels”. There are many approaches to avoiding waveguiding limitations intrinsic to the planar OLED structure including use of textured substrates, microcavity designs and incorporating scattering layers into the device structure. We have chosen to pursue scattering layers since it addresses the largest source of loss which is waveguiding in the OLED itself. Scattering layers also have the potential to be relatively robust to color, polarization and angular distributions. We note that this can be combined with textured or microlens decorated substrates to achieve additional enhancement.

  20. Using nanoimprint lithography to improve the light extraction efficiency and color rendering of dichromatic white light-emitting diodes

    Science.gov (United States)

    Lee, Yang-Chun; Chen, Hsuen-Li; Lu, Chih-Yu; Wu, Hung-Sen; Chou, Yung-Fang; Chen, Szu-Huang

    2015-10-01

    Despite the efficiency of gallium nitride (GaN)-based blue light-emitting diodes (LEDs), the light extraction arising from the packaging of the phosphor remains an important issue when enhancing the performance of dichromatic white LEDs. In this study, we employed a simple, inexpensive nanoimprinting process to increase both the light extraction efficiency and color rendering of dichromatic white LEDs. We employed the rigorous coupled wave approach (RCWA) to optimize the light extraction efficiency of yellow and blue light. We found that the presence of the light extracting structures could also improve the color rendering of the dichromatic white LEDs, due to the different light extraction efficiencies of the textured structures at different wavelengths. After fabricating inverted pyramid structures on the surface of the encapsulation layer, the intensity of the blue light at 455 nm increased by 20%. When we further considered the color rendering and correlated color temperature (CCT), the enhancement of blue light was 15% and that of yellow light was 4%. Meanwhile, the light extraction of the intensity dip near 490 nm was enhanced significantly (by 25%), resulting in an increased dip-intensity of light at 490 nm relative to the intensities of the blue and yellow light. Accordingly, the color rendering index (CRI) of this dichromatic white LED increased from 69 to 73. Because it improved both the light extraction efficiency and color rendering of dichromatic white LEDs, this simple method should be very helpful for enhancing their applications in solid state illumination.Despite the efficiency of gallium nitride (GaN)-based blue light-emitting diodes (LEDs), the light extraction arising from the packaging of the phosphor remains an important issue when enhancing the performance of dichromatic white LEDs. In this study, we employed a simple, inexpensive nanoimprinting process to increase both the light extraction efficiency and color rendering of dichromatic white

  1. Effects of the microstructure slab with pillars on light extraction of GaN light-emitting diode

    Institute of Scientific and Technical Information of China (English)

    Li Yan; Zheng Rui-Sheng; Feng Yu-Chun; Liu Song-Hao; Niu Han-Ben

    2006-01-01

    The Dositive z direction relative light-extraction efficiency of GaN light-emitting diodes with microstructure slab is calculated by three-dimensional finite-difference time-domain method,where the microstructure slab consists of a graphite lattice of pillars.The results show that the two-dimensional graphite-arranged pillars suppress light extraction.When there is a thick pillar in the middle of the pillars,the structure can enhance light extraction of the light-emitting diodes.The tower-like pillars,which are thin on the top of the pillars and thick on the bottom of the pillars,benefit the light extraction when the angle of the tower-like pillars is proper.

  2. Commercial Light Water Reactor Tritium Extraction Facility Geotechnical Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, M R

    2000-01-11

    A geotechnical investigation program has been completed for the Circulating Light Water Reactor - Tritium Extraction Facility (CLWR-TEF) at the Savannah River Site (SRS). The program consisted of reviewing previous geotechnical and geologic data and reports, performing subsurface field exploration, field and laboratory testing and geologic and engineering analyses. The purpose of this investigation was to characterize the subsurface conditions for the CLWR-TEF in terms of subsurface stratigraphy and engineering properties for design and to perform selected engineering analyses. The objectives of the evaluation were to establish site-specific geologic conditions, obtain representative engineering properties of the subsurface and potential fill materials, evaluate the lateral and vertical extent of any soft zones encountered, and perform engineering analyses for slope stability, bearing capacity and settlement, and liquefaction potential. In addition, provide general recommendations for construction and earthwork.

  3. Spectral-distortion-free light extraction from organic light-emitting diodes using nanoscale photonic crystal

    Science.gov (United States)

    Shim, Yong Sub; Nyun Kim, Kyu; Hwang, Ju Hyun; Hwee Park, Cheol; Jung, Sun-Gyu; Park, Young Wook; Ju, Byeong-Kwon

    2017-01-01

    Despite their generally good performance, photonic crystal (PC)-based organic light-emitting diodes (OLEDs) encounter a serious spectral distortion problem. In this study, we obtained spectral-distortion-free PC-based OLEDs by lowering the pitch (period of the PC) to less than a half the emission wavelength, using a simple and scalable nanoscale process of laser interference lithography. The demonstrated OLEDs with 200 nm pitch-size nanoscale periodic hole arrays exhibited negligible changes in the Internal Commission on Illumination 1931 color coordinate of Δ (0.0104, 0.0078) and a peak wavelength of Δ0 nm (relative to the reference), while maintaining the function of the internal light extraction layer, manifested as a 23% enhancement of the external quantum efficiency (EQE). The enhancement of the EQE reached 85% after incorporating a micro-lens array. The improved light extraction, spectral-distortion-free characteristic, and excellent color stability over a broad range of viewing angles were successfully derived by performing finite difference time domain simulations.

  4. Combining surface plasmonic and light extraction enhancement on InGaN quantum-well light-emitters

    DEFF Research Database (Denmark)

    Fadil, Ahmed; Ou, Yiyu; Iida, Daisuke

    2016-01-01

    Surface plasmon coupling with light-emitters and surface nano-patterning have widely been used separately to improve low efficiency InGaN light-emitting diodes. We demonstrate a method where dielectric nano-patterning and Ag nanoparticles (NPs) are combined to provide both light extraction...... and internal quantum efficiency enhancement for InGaN/GaN quantum-well light-emitters. By fabricating dielectric nano-rod pattern on the GaN surface, an optical coating that improves the light extraction is obtained, and furthermore has a low refractive index which blue-shifts the plasmonic resonance of Ag NPs...

  5. Enhancing the light extraction efficiency of AlGaN deep ultraviolet light emitting diodes by using nanowire structures

    Energy Technology Data Exchange (ETDEWEB)

    Djavid, Mehrdad; Mi, Zetian, E-mail: zetian.mi@mcgill.ca [Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, QC H3A 0E9 (Canada)

    2016-02-01

    The performance of conventional AlGaN deep ultraviolet light emitting diodes has been limited by the extremely low light extraction efficiency (<10%), due to the unique transverse magnetic (TM) polarized light emission. Here, we show that, by exploiting the lateral side emission, the extraction efficiency of TM polarized light can be significantly enhanced in AlGaN nanowire structures. Using the three-dimensional finite-difference time domain simulation, we demonstrate that the nanowire structures can be designed to inhibit the emission of guided modes and redirect trapped light into radiated modes. A light extraction efficiency of more than 70% can, in principle, be achieved by carefully optimizing the nanowire size, nanowire spacing, and p-GaN thickness.

  6. Photonic crystals to enhance light extraction from 2D materials

    CERN Document Server

    Noori, Yasir J; Roberts, Jonathan; Woodhead, Christopher; Bernardo-Gavito, Ramon; Tovee, Peter; Young, Robert J

    2016-01-01

    We propose a scheme for coupling 2D materials to an engineered cavity based on a defective rod type photonic crystal lattice. We show results from numerical modelling of the suggested cavity design, and propose using the height profile of a 2D material transferred on top of the cavity to maximise coupling between exciton recombination and the cavity mode. The photonic structure plays a key role in enhancing the launch efficiency, by improving the directionality of the emitted light to better couple it into an external optical system. When using the photonic structure, we measured an increase in the extraction ratio by a factor of 3.4. We investigated the variations in the flux spectrum when the radius of the rods is modified, and when the 2D material droops to a range of different heights within the cavity. We found an optimum enhancement when the rods have a radius equal to 0.165 times the lattice constant, this enhancement reduces when the radius is reduced or increased. Finally, we discuss the possible use...

  7. Light extraction efficiency enhancement in light-emitting diodes with indium tin oxide nano-craters

    Institute of Scientific and Technical Information of China (English)

    Zheng Huaiwen; Zhang Yiyun; Yang Hua; Xue Bin; Wu Kui; Li Jing; Wang Guohong

    2012-01-01

    A simple and low cost method is described which improves extraction efficiency.The indium tin oxide (ITO) textured film was fabricated by using the self-assembly method and dry-etching.The surface morphologies and surface roughness were observed by using an atomic force microscope.The Ⅰ-Ⅴ characteristics,output power and polar radiation pattern of the LEDs with and without textured ITO were measured for comparison.Cylinders and craters were formed on the ITO surface after the etching,the height of which increased with etching time.The output power of the devices is proportional to the etching time.Total internal reflection of light on the ITO-GaN interface is reduced due to the appearance of cylinders and craters,and their increasing height.Thus,the output power is improved.

  8. Light Extraction Enhancement of GaN LED with a Two-Dimensional Photonic Crystal Slab

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-Wei; KAN Qiang; WANG Chun-Xia; HU Hai-Yang; XU Xing-Sheng; CHEN Hong-Da

    2011-01-01

    Light extraction effects of a photonic crystal slab with a micrometer scale lattice constant are studied. A GaN light emitting diode (LED) with a photonic crystal slab is fabricated. The light extraction effects and the enhancement mechanism are investigated. From theoretical analysis, it is found that the characteristics of LED light emission are modulated by the photonic crystal slab. Experimental results show that the LED light emission intensity is enhanced by 38% due to guide mode extracting by the photonic crystal.%@@ Light extraction effects ora photonic crystal slab with a micrometer scale lattice constant are studied.A GaN light emitting diode(LED) with a photonic crystal slab is fabricated.The light extraction effects and the enhancement mechanism are investigated.From theoretical analysis,it is found that the characteristics of LED light emission are modulated by the photonic crystal slab.Experimental results show that the LED light emission intensity is enhanced by 38% due to guide mode extracting by the photonic crystal.

  9. Competition between the filth fly parasitoids Muscidifurax raptor and M. raptorellus (Hymenoptera: Pteromalidae).

    Science.gov (United States)

    Geden, C J; Johnson, D M; Kaufman, P E; Boohene, C K

    2014-12-01

    Competition bioassays were conducted with the filth fly pupal parasitoids Muscidurax raptor (Girault & Sanders) and M. raptorellus (Kogan & Legner) (Hymenoptera: Pteromalidae) using house fly Musca domestica L. (Diptera: Muscidae) hosts at different host densities. Muscidifurax raptor had a significant impact on M. raptorellus when hosts were limiting in sequential parasitism tests. Fewer than six M. raptorellus adult progeny emerged from groups of 50 fly pupae that were parasitized by M. raptor at the same time or when M. raptor parasitism preceded M. raptorellus by 48 h, respectively, compared with 42-55 M. raptorellus progeny produced when this species was tested alone. Production of M. raptor was significantly lower when parasitism by this species was preceded by M. raptorellus (25) than when M. raptor was tested alone (43). When the two species parasitized hosts at the same time in different proportions at low host:parasitoid densities (5:1), M. raptorellus produced 13 progeny per parent female when it was the sole species present and fewer than two when M. raptor was present. No negative impact of M. raptorellus on M. raptor was observed. Neither species had a substantial effect on the success of the other at higher host:parasitoid densities.

  10. High light-extraction-efficiency OLED based on photonic crystal slab structures with taper unit cells

    Institute of Scientific and Technical Information of China (English)

    YAN Rong-jin; WANG Qing-kang

    2006-01-01

    To improve the light-extraction-efficiency of OLED,we introduced PCS (Photonic Crystal Slab) structures into the interface of ITO layer and glass substrate.PCS structures with Taper unit cells are proved to be effective in reducing the energy of guided wave trapped in high refractive index material,and an increase of light-extraction-efficiency to 95.26% is gained.This enhancement is much greater than the traditional PCS with cylinder unit cells (60%-70%).Physical mechanisms of light-extraction-efficiency enhancement in these structures are further discussed.

  11. Angular distribution of polarized light and its effect on light extraction efficiency in AlGaN deep-ultraviolet light-emitting diodes.

    Science.gov (United States)

    Chen, Xinjuan; Ji, Cheng; Xiang, Yong; Kang, Xiangning; Shen, Bo; Yu, Tongjun

    2016-05-16

    Angular distribution of polarized light and its effect on light extraction efficiency (LEE) in AlGaN deep-ultraviolet (DUV) light-emitting diodes (LEDs) are investigated in this paper. A united picture is presented to describe polarized light's emission and propagation processes. It is found that the electron-hole recombinations in AlGaN multiple quantum wells produce three kinds of angularly distributed polarized emissions and propagation process can change their intensity distributions. By investigation the change of angular distributions in 277nm and 215nm LEDs, this work reveals that LEE can be significantly enhanced by modulating the angular distributions of polarized light of DUV LEDs.

  12. Efficient light extraction from GaN LEDs using gold-coated ZnO nanoparticles

    KAUST Repository

    Alhadidi, A.

    2015-11-01

    We experimentally demonstrate the effect of depositing gold-coated ZnO nanoparticles on the surface of GaN multi-quantum well LED structures. We show that this method can significantly increase the amount of extracted light.

  13. Enhancement of light extraction efficiency in OLED with two-dimensional photonic crystal slabs

    Institute of Scientific and Technical Information of China (English)

    Rongjin Yan; Qingkang Wang

    2006-01-01

    Light extraction efficiency of organic light emitting diode (OLED) based on various photonic crystal slab (PCS) structures was studied. By using the finite-difference time-domain (FDTD) method, we investigated the effect of several parameters, including filling factor and lattice constant, on the enhancement of light extraction efficiency of three basic PCSs, and got the most effective one. Two novel designs of "interlaced"and "double-interlaced" PCS structures based on the most effective basic PCS structure were introduced,and the "interlaced" one was proved to be even more efficient than its prototype. Large enhancement of light extraction efficiency resulted from the coupling to leaky modes in the expended light cone of a band structure, the diffraction in the space between columns, as well as the strong scattering at indium-tinoxide/glass interfaces.

  14. Double-Grating Displacement Structure for Improving the Light Extraction Efficiency of LEDs

    Directory of Open Access Journals (Sweden)

    Zhibin Wang

    2012-01-01

    Full Text Available To improve the light extraction efficiency of light-emitting diodes (LEDs, grating patterns were etched on GaN and silver film surfaces. The grating-patterned surface etching enabled the establishment of an LED model with a double-grating displacement structure that is based on the surface plasmon resonance principle. A numerical simulation was conducted using the finite difference time domain method. The influence of different grating periods for GaN surface and silver film thickness on light extraction efficiency was analyzed. The light extraction efficiency of LEDs was highest when the grating period satisfied grating coupling conditions. The wavelength of the highest value was also close to the light wavelength of the medium. The plasmon resonance frequencies on both sides of the silver film were affected by silver film thickness. With increasing film thickness, plasmon resonance frequency tended toward the same value and light extraction efficiency reached its maximum. When the grating period for the GaN surface was 365 nm and the silver film thickness was 390 nm, light extraction efficiency reached a maximum of 55%.

  15. Photon extraction from nitride ultraviolet light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Schowalter, Leo J; Chen, Jianfeng; Grandusky, James R

    2015-02-24

    In various embodiments, a rigid lens is attached to a light-emitting semiconductor die via a layer of encapsulant having a thickness insufficient to prevent propagation of thermal expansion mismatch-induced strain between the rigid lens and the semiconductor die.

  16. Search for an optimal light-extracting surface derived from the morphology of a firefly lantern

    Science.gov (United States)

    Bay, Annick; Sarrazin, Michaël; Vigneron, Jean Pol

    2013-02-01

    Fireflies light up our warm summer evenings. There is more physics behind these little animals than any one of us could imagine. We analyze from a physical point of view one structure found on the firefly lantern, the one which best improves light extraction. Moreover, simulations will be done to show why this specific structure may be more effective than one designed by humans.

  17. Enhanced light extraction efficiency of micro-ring array AlGaN deep ultraviolet light-emitting diodes

    Science.gov (United States)

    Bekele Fayisa, Gabisa; Lee, Jong Won; Kim, Jungsub; Kim, Yong-Il; Park, Youngsoo; Kim, Jong Kyu

    2017-09-01

    An effective approach to overcome inherently poor light extraction efficiency of AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) is presented. We demonstrated the 5 × 5 array micro-ring DUV LED having an inclined sidewall at the outer perimeter and a p-GaN-removed inner circle of the micro-ring, together with MgF2/Al omnidirectional reflectors. The micro-ring array DUV LED shows remarkably higher light output power by 70% than the reference, consistent with the calculated result, as well as comparable turn-on and operational voltages, which are attributed to the effective extraction of strong transverse-magnetic polarized anisotropic emission and the reduction of the absorption loss by the p-GaN contact layer, simultaneously.

  18. Enhanced light extraction efficiency of GaN-based light-emittng diodes by nitrogen implanted current blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Deok; Oh, Seung Kyu; Park, Min Joo; Kwak, Joon Seop, E-mail: jskwak@sunchon.ac.kr

    2016-10-15

    Highlights: • A nitrogen implanted current-blocking layer was successfully demonstrated. • Light-extraction efficiency and radiant intensity was increased by more than 20%. • Ion implantation was successfully implemented in GaN based light-emitting diodes. - Abstract: GaN-based light emitting diodes (LEDs) with a nitrogen implanted current-blocking layer (CBL) were successfully demonstrated for improving the light extraction efficiency (LEE) and radiant intensity. The LEE and radiant intensity of the LEDs with a shallow implanted CBL with nitrogen was greatly increased by more than 20% compared to that of a conventional LED without the CBL due to an increase in the effective current path, which reduces light absorption at the thick p-pad electrode. Meanwhile, deep implanted CBL with a nitrogen resulted in deterioration of the LEE and radiant intensity because of formation of crystal damage, followed by absorption of the light generated at the multi-quantum well(MQW). These results clearly suggest that ion implantation method, which is widely applied in the fabrication of Si based devices, can be successfully implemented in the fabrication of GaN based LEDs by optimization of implanted depth.

  19. Numerical analysis of nanostructures for enhanced light extraction from OLEDs

    CERN Document Server

    Zschiedrich, L; Burger, S; Schmidt, F; 10.1117/12.2001132

    2013-01-01

    Nanostructures, like periodic arrays of scatters or low-index gratings, are used to improve the light outcoupling from organic light-emitting diodes (OLED). In order to optimize geometrical and material properties of such structures, simulations of the outcoupling process are very helpful. The finite element method is best suited for an accurate discretization of the geometry and the singular-like field profile within the structured layer and the emitting layer. However, a finite element simulation of the overall OLED stack is often beyond available computer resources. The main focus of this paper is the simulation of a single dipole source embedded into a twofold infinitely periodic OLED structure. To overcome the numerical burden we apply the Floquet transform, so that the computational domain reduces to the unit cell. The relevant outcoupling data are then gained by inverse Flouqet transforming. This step requires a careful numerical treatment as reported in this paper.

  20. [Cataract extraction and blue light--impact on the retina].

    Science.gov (United States)

    Engelmann, K; Funk, R H

    2009-10-01

    This review focuses on the scientific background for the use of "yellow artificial lenses". We will address the fact that numerous basic scientific publications point to a rationale for this practice although it is often difficult to derive clear-cut evidence from clinical epidemiological studies for the preventive use of yellow artificial lenses. In the first part we refer to studies showing that especially the shortwave part of the visible spectrum of light can be harmful for the retina and optic nerve. For this, we have screened the literature for the major sources of radical production and for the targets of oxidative stress after impingement of "blue light" on the retina. Furthermore, we can show that many studies in cell and molecular biology, animal experiments and first clinical trials point to a preferential use of yellow-tinted lenses especially in the elderly and AMD patients.

  1. Optimization of the light extraction from heavy inorganic scintillators

    CERN Document Server

    Kronberger, Matthias; Lecoq, P

    2008-01-01

    Inorganic scintillators are widely used in modern medical imaging modalities as converter for the X- and gamma-radiation that is used to obtain information about the interior of the body. Likewise, they are applied in high-energy physics to measure the energy of particles that are produced in particle physics experiments. Their use is motivated by the very good detection efficiency of these materials for hard radiation which allows the construction of relatively compact and finely pixelised systems with a high spatial resolution. One key problem in the development of the next generation of particle detectors and medical imaging systems is the optimisation of the energy resolution of the detectors. This parameter is influenced by the statistical fluctuations of the light output of the scintillators, i.e. by the number of photons that are detected when a particle deposits its energy in the scintillator. The light output of the scintillator depends not only on the absolute number of generated photons but also on...

  2. SIMPLIFIED BUILDING MODELS EXTRACTION FROM ULTRA-LIGHT UAV IMAGERY

    Directory of Open Access Journals (Sweden)

    O. Küng

    2012-09-01

    Full Text Available Generating detailed simplified building models such as the ones present on Google Earth is often a difficult and lengthy manual task, requiring advanced CAD software and a combination of ground imagery, LIDAR data and blueprints. Nowadays, UAVs such as the AscTec Falcon 8 have reached the maturity to offer an affordable, fast and easy way to capture large amounts of oblique images covering all parts of a building. In this paper we present a state-of-the-art photogrammetry and visual reconstruction pipeline provided by Pix4D applied to medium resolution imagery acquired by such UAVs. The key element of simplified building models extraction is the seamless integration of the outputs of such a pipeline for a final manual refinement step in order to minimize the amount of manual work.

  3. Nanostructured graded-index antireflection layer formation on GaN for enhancing light extraction from light-emitting diodes

    Science.gov (United States)

    Dylewicz, R.; Khokhar, A. Z.; Wasielewski, R.; Mazur, P.; Rahman, F.

    2012-05-01

    We describe the fabrication and characterization of a randomly etched gallium nitride (GaN) surface for enhancing light extraction from light-emitting diodes. Our technique uses silica spheres as nano-targets in a sputter-etch process and produces a fine-grained surface with features around 35 nm. The textured surface layer acts as a graded refractive index layer with antireflection properties. Measurements show that photoluminescence intensity from such treated surfaces on a GaN LED wafer increases 2.2 times over that from pristine surfaces. These findings are also supported by computer modelling studies described here.

  4. Optimal overlayer inspired by Photuris firefly improves light-extraction efficiency of existing light-emitting diodes.

    Science.gov (United States)

    Bay, Annick; André, Nicolas; Sarrazin, Michaël; Belarouci, Ali; Aimez, Vincent; Francis, Laurent A; Vigneron, Jean Pol

    2013-01-14

    In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is described. The purpose of this overlayer is to improve light extraction into air from the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp. The actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. This two-dimensional pattern contrasts other designs by its unusual profile, its larger dimensions and the fact that it can be tailored to an existing diode design rather than requiring a complete redesign of the diode geometry. The gain of light extraction reaches values up to 55% with respect to the reference unprocessed LED.

  5. Light extraction enhancement of AlGaN-based ultraviolet light-emitting diodes by substrate sidewall roughening

    Science.gov (United States)

    Guo, Yanan; Zhang, Yun; Yan, Jianchang; Xie, Haizhong; Liu, Lei; Chen, Xiang; Hou, Mengjun; Qin, Zhixin; Wang, Junxi; Li, Jinmin

    2017-07-01

    The effect of sapphire substrate's sidewall roughening on light extraction of AlGaN-based ultraviolet light-emitting diodes (UV LEDs) is investigated. Finite-difference time-domain simulation reveals that a roughening region for effective light extraction enhancement exists on the substrate's sidewall. Roughening outside the effective roughening region will result in undesirable inward photon scattering and absorption. For TM-polarization-dominated deep-UV LEDs, the effective roughening region is from the substrate's backside to the position about L/2 × tan(θc) away from the substrate's front side, where L is the side length of the LED device and θc is the critical angle of total reflection. In the LED device fabrication, picosecond laser dicing is employed to realize roughening layers on the sapphire substrate's sidewalls. The UV LEDs with three roughening layers have 13.2% higher average light output power (LOP) at 20 mA than those with two roughening layers, thanks to the larger roughening area in the effective roughening region. When additional roughening layers beyond the effective roughening region are applied, the LOP decreases as the simulation predicts. Furthermore, the values of leakage current and forward voltage of these LEDs are consistently below 0.2 μA at -10 V and 5.8-6.0 V at 20 mA, respectively, showing no thermal damage to intrinsic diode performance by the laser processing.

  6. Polystyrene-catalytic indium-tin-oxide nanorods grown on green light-emitting diodes for enhancing light extraction

    Science.gov (United States)

    Gong, Zhina; Li, Qiang; Li, Yufeng; Xiong, Han; Liu, Hao; Wang, Shuai; Zhang, Ye; Guo, Maofeng; Yun, Feng

    2016-08-01

    A novel technique for fabricating indium-tin-oxide (ITO) nanorods (NRs) on hexagonal-pyramid-surface green vertical light-emitting diodes (VLEDs) is demonstrated using electron-beam deposition with polystyrene spheres catalysis. The ITO NRs have high optical transmittance (>90%) in green wavelength and good crystal quality with a cubic structure. The VLED with ITO NRs has a 31% enhancement of light output power at 200 mA, compared with those without ITO NRs. Finite-difference time-domain simulations suggest that the power enhancement is attributed to the gradient refractive indices of the ITO NRs, and that the light extraction enhancement is caused by changes in ITO NR heights.

  7. Spontaneous Emission and Light Extraction Enhancement of Light Emitting Diode Using Partially-Reflecting Metasurface Cavity (PRMC)

    CERN Document Server

    Chen, Luzhou; Kallos, Themos; Caloz, Christophe

    2016-01-01

    The enhancement of the power conversion efficiency (PCE), and subsequent reduction of cost, of light emitting diodes (LEDs) is of crucial importance in the current lightening market. For this reason, we propose here a PCE-enhanced LED architecture, based on a partially-reflecting metasurface cavity (PRMC) structure. This structure simultaneously enhances the light extraction efficiency (LEE) and the spontaneous emission rate (SER) of the LED by enforcing the emitted light to radiate perpendicularly to the device, so as to suppress wave trapping and enhance lateral field confinement, while ensuring cavity resonance matching and maximal constructive field interference. The PRMC structure is designed using a recent surface susceptibility metasurface synthesis technique. A PRMC blue LED design is presented and demonstrated by full-wave simulation to provide LEE and SER enhancements by factors 4.0 and 1.9, respectively, corresponding to a PCE enhancement factor of 7.6, suggesting that the PRMC concept has a promis...

  8. Enhancement of light extraction efficiency of vertical LED with patterned graphene as current spreading layer

    Science.gov (United States)

    Singh, Sumitra; Sai Nandini, Annam Deepthi; Pal, Suchandan; Dhanavantri, Chenna

    2016-01-01

    In this paper we report an optimised pattern of surface textured graphene current spreading layer (CSL) for the enhancement of light extraction efficiency (LEE) in InGaN/GaN vertical light emitting diodes (V-LEDs). It is found that by texturing graphene surface LEE improves drastically. This improvement is attributed to better current spreading of graphene and increased random and multiple scattering of light through textured surfaces. Simulation results illustrate that V-LEDs with surface textured (hexagonal pattern) ITO as CSL shows threefold improvement in light extraction efficiency compared to V-LEDs with no surface texturing on ITO CSL. Further, LEE of V-LEDs having patterned graphene CSL is compared with that for indium tin oxide (ITO) CSL. V-LEDs with optimised hexagonal patterning on graphene CSL shows 13.42% enhancement of LEE compared to that of LED with hexagonal patterning on ITO surface.

  9. Optical anisotropy and light extraction efficiency of MBE grown GaN nanowires epilayers.

    Science.gov (United States)

    Henneghien, Anne-Line; Tourbot, Gabriel; Daudin, Bruno; Lartigue, Olivier; Désières, Yohan; Gérard, Jean-Michel

    2011-01-17

    The use of nanowires as active medium seems very promising for the development of high brightness LEDs. With a lower effective refractive index than bulk, semiconductor nanowire layers may lead to a high light extraction efficiency. We hereafter discuss the anisotropic properties of dense arrays of molecular beam epitaxy (MBE) grown gallium nitride (GaN) nanowires and the consequences on the optical design of nanowire based LEDs. In particular we show numerically that light extraction efficiency as high as 72% can be expected for GaN nanowires layer grown on a low cost Si substrate.

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

    Science.gov (United States)

    Li, Ting

    2013-08-13

    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.

  11. Polarized backlight with constrained angular divergence for enhancement of light extraction efficiency from wire grid polarizer.

    Science.gov (United States)

    Yao, Po-Hung; Chung, Chi-Jui; Wu, Chien-Li; Chen, Cheng-Huan

    2012-02-27

    Efficiency of liquid crystal displays highly depends on the amount of polarized light emerging from the backlight module. In this paper, a backlight architecture using a nanoimprint wire grid polarizer for polarization recycling is proposed and studied, in which the extraction efficiency of polarized light is the major concern. The backlight module is composed of the stack of a wire grid polarizer, a lenticular array and a light guide plate. The light guide plate features interleaving v-groove and trapezoidal ridge coated with aluminum on the top surface, and scattering dot array on the bottom. The angular divergence of emerging light from the light guide plate can be well constrained so as to exploit the angular range with the best transmission of polarized light for the wire grid polarizer. The prototype of a 2.5-inch module has demonstrated an angular divergence of 48°. The overall extraction efficiency of polarized light enhanced by 21% and uniformity of 76% have been achieved.

  12. Anti-inflammatory effects of green soybean extract irradiated with visible light.

    Science.gov (United States)

    Tanaka, Keiko; Ohgo, Yasushi; Katayanagi, Yuki; Yasui, Kensuke; Hiramoto, Shigeru; Ikemoto, Hiroyuki; Nakata, Yumi; Miyoshi, Noriyuki; Isemura, Mamoru; Ohashi, Norio; Imai, Shinjiro

    2014-04-22

    We conducted a preliminary investigation of the effects of visible light irradiation on plant extracts, and we observed a strong suppressive effect on interleukin (IL) 2 expression with the inhibition of c-Jun amino-terminal kinase (JNK) phosphorylation in Jurkat cells by visible light irradiation to ethanol extract from green soybeans (LIEGS). This effect was produced only by extracts from green soybeans (Glycine max) and not other-color soybeans. LIEGS suppressed the lipopolysaccharide-induced IL-6, IL-12 and TNF-α expression levels in human monocyte THP-1 cells in a concentration-dependent manner. LIEGS was applied for 8 weeks to NC/Nga mice. LIEGS suppressed the development of atopic dermatitis (AD)-like skin lesions and reduced the dermatitis scores of the mice. The light irradiation changed the various types of small-molecule compounds in extracts. Visible light irradiation to daidzein with chlorophyll b induced a novel oxidative product of daidzein. This product suppressed IL-2 expression in Jurkat cells.

  13. Effects of pulsed UV-light on peanut allergens in extracts and liquid peanut butter.

    Science.gov (United States)

    Chung, S-Y; Yang, W; Krishnamurthy, K

    2008-06-01

    Pulsed ultraviolet (PUV) light, a nonthermal technology, was used to treat both the peanut extracts and liquid peanut butter. The objective was to determine if such treatment would lead to a reduction in the allergenic properties of the peanut extract and butter. Peanut samples were PUV treated using a Xenon RS-3000C under the following conditions: 3 pulses/s, 14.6 cm from the central axis of the lamp, 4 min (extract) or 3 min (liquid peanut butter). After the treatment, the peanut samples were centrifuged and the supernatants analyzed by SDS-PAGE and competitive inhibition enzyme-linked immunosorbent assay (ciELISA). For comparison, boiling treatments were also performed. SDS-PAGE showed that while boiling treatment had little effect on the peanut allergens, PUV-light-treated samples displayed a reduced solubility or level of peanut allergens (63 kDa). Solubility of another allergen (18 to 20 kDa) was unaffected. Insoluble aggregates formed were responsible for the reduced level of allergens in PUV-light-treated samples. ciELISA showed that untreated samples exhibited an IgE binding 7-fold higher than the PUV-treated samples. It was concluded that PUV light was effective in reducing IgE binding of peanut extracts and liquid peanut butter. The current study provides an approach to the development of a possibly less allergenic peanut product. However, the reduction in actual allergenicity needs to be confirmed by clinical studies.

  14. Visible light absorption and photo-sensitizing properties of spinach leaves and beetroot extracted natural dyes.

    Science.gov (United States)

    Sengupta, D; Mondal, B; Mukherjee, K

    2015-09-05

    Herein, chlorophyll and betalain dyes are extracted from fresh spinach leaves and beetroots. Fourier transform infrared spectra are used to identify the characteristic peaks of the extracted dyes. UV-vis light absorption characteristics of the dyes and their mixed counterpart are investigated by varying their pH and temperature. These dyes are used as photo sensitizer for fabrication of zinc oxide photo-anode based dye sensitized solar cells (DSSCs). The photo-voltaic characteristics of the developed DSSCs are measured under simulated solar light (power of incident light 100 mW cm(-2) from Air Mass 1.5G). The solar to electric conversion efficiencies for the chlorophyll, betalain and mixed dye based solar cells are estimated as 0.148%, 0.197% and 0.294% respectively. The highest conversion efficiency for mixed dye based solar cell is attributed due to the absorption of wider range of solar spectrum.

  15. An improved extraction for the multicusp-type light ion-ion source apparatus

    Science.gov (United States)

    Reijonen, J.; Heikkinen, P.; Liukkonen, E.; ńrje, J.

    1998-02-01

    A new ion extraction system has been developed for use with the light ion source apparatus (LIISA) of the Accelerator Laboratory. The aim of the new extraction system is to have a more intense and better quality beam. For simulation of the beam behavior at the extraction region a computer code IGUNe has been used. The simulation shows that a simple triode extraction would be efficient enough to extract total beam intensities of around 5 mA at an extraction voltage of 10-15 kV. At the same time, with the carefully designed plasma electrode, the emittance could be decreased significantly from the original design. The new extraction was installed in May 1997 and the results have been encouraging. The transport efficiency of the extracted beam to the first Faraday cup (at a distance of 1.2 m) was 100% and the maximum proton current obtained was 2.0 mA. The maximum proton current in the cyclotron inflector is 1.0 mA, which is eight times larger than the previous record.

  16. Light extraction of GaN LEDs with 2-D photonic crystal structure

    Institute of Scientific and Technical Information of China (English)

    Hongwei Liu; Qiang Kan; Chunxia Wang; Feng Yu; Xingsheng Xu; Hongda Chen

    2009-01-01

    Ultraviolet photo-lithography is employed to introduce two-dimensional (2D) photonic crystal (PC) structure on the top surface of GaN-based light emitting diode (LED).PC patterns are transferred to 460-nmthick transparent indium tin oxide (ITO) electrode by inductively coupled plasma (ICP) etching.Light intensity of PC-LED can be enhanced by 38% comparing with the one without PC structure.Rigorous coupled wave analysis method is performed to calculate the light transmission spectrum of PC slab.Simulation results indicate that total internal reflect angle which modulated by PC structure has been increased by 7°,which means that the light extraction efficiency is enhanced outstandingly.

  17. Improvement of extraction efficiency for GaN-based light emitting diodes

    Institute of Scientific and Technical Information of China (English)

    SU; YanKuin; CHEN; JianJhong; KAO; ChienChih; TSAI; ChunFu

    2010-01-01

    A simple, low cost method for mass production to enhance the light extraction efficiency of GaN-related LEDs was proposed. With appropriate process parameters, the nature lithography of nanosphere can be used to fabricate two-dimensional nanostructures, including the nanomesh ZnO layer, photonic crystal (PhC) patterned p-GaN, and patterned sapphire substrates. Based on preliminary results, the extraction efficiencies of LEDs with these nanostructures can thus be improved and the nature lithography is demonstrated to be a promising method to be widely exploited in the manufacture of all kinds of LED devices.

  18. Prevention of retinal light damage by zinc oxide combined with rosemary extract

    OpenAIRE

    Organisciak, Daniel T.; Darrow, R. M.; Rapp, C. M.; Smuts, J. P.; Armstrong, D.W.; Lang, J. C.

    2013-01-01

    Purpose Zinc oxide effectively reduces visual cell loss in rats exposed to intense visible light and is known to slow the rate of disease progression in advanced stages of age-related macular degeneration. Our goal was to determine the efficacy of zinc oxide in combination with novel and well-established antioxidants in an animal model of light-induced oxidative retinal damage. Methods One group of male Sprague-Dawley rats was pretreated with zinc oxide with or without a detergent extract of ...

  19. Light-emitting diode assessment of dentinal defects: the role of presumed extraction forces.

    Science.gov (United States)

    Coelho, Marcelo Santos; Card, Steven J; Tawil, Peter Z

    2017-08-01

    The evaluation of iatrogenic dentinal defects in extracted teeth may be influenced by extraction forces and prolonged dry times. The purpose of this study was to compare the presence of dentinal defects in freshly extracted, periodontally compromised teeth with those in a group of teeth with uncontrolled extraction forces and storage time. The experimental group consisted of eighteen roots obtained from teeth extracted due to periodontal reasons with class II or III mobility. They were kept in saline and sectioned within 1 hour following extraction. The control group consisted of matched root types obtained from an anonymous tooth collection, consistent with previous dentinal defect studies. The slices were obtained at 3, 6, and 9 mm from the apex. The imaging process exposed all specimens to no more than 60 seconds of dry time. The × 12.8 magnification was used for the 9 mm slices and × 19.2 magnification for the 3 mm and 6 mm slices under light-emitting diode (LED) transillumination. The root canal spaces and periodontal tissues were masked to minimize extraneous factors that might influence the evaluators. Chi-square test was used for statistical analysis. Dentinal defects were detected in 17% of the experimental group teeth, compared to 61% of control teeth (p = 0.015). LED transillumination assessment of freshly extracted roots with class II or III mobility showed smaller number of dentinal defects than roots with uncontrolled storage time and extraction forces. The use of freshly extracted roots with mobility should be considered for future dental defect assessment studies.

  20. Light-emitting diode assessment of dentinal defects: the role of presumed extraction forces

    Directory of Open Access Journals (Sweden)

    Marcelo Santos Coelho

    2017-07-01

    Full Text Available Objectives The evaluation of iatrogenic dentinal defects in extracted teeth may be influenced by extraction forces and prolonged dry times. The purpose of this study was to compare the presence of dentinal defects in freshly extracted, periodontally compromised teeth with those in a group of teeth with uncontrolled extraction forces and storage time. Materials and Methods The experimental group consisted of eighteen roots obtained from teeth extracted due to periodontal reasons with class II or III mobility. They were kept in saline and sectioned within 1 hour following extraction. The control group consisted of matched root types obtained from an anonymous tooth collection, consistent with previous dentinal defect studies. The slices were obtained at 3, 6, and 9 mm from the apex. The imaging process exposed all specimens to no more than 60 seconds of dry time. The × 12.8 magnification was used for the 9 mm slices and × 19.2 magnification for the 3 mm and 6 mm slices under light-emitting diode (LED transillumination. The root canal spaces and periodontal tissues were masked to minimize extraneous factors that might influence the evaluators. Chi-square test was used for statistical analysis. Results Dentinal defects were detected in 17% of the experimental group teeth, compared to 61% of control teeth (p = 0.015. Conclusions LED transillumination assessment of freshly extracted roots with class II or III mobility showed smaller number of dentinal defects than roots with uncontrolled storage time and extraction forces. The use of freshly extracted roots with mobility should be considered for future dental defect assessment studies.

  1. Search for an optimal light-extracting surface derived from the morphology of a firefly lantern

    CERN Document Server

    Bay, Annick; Vigneron, Jean Pol

    2012-01-01

    Fireflies lighten up our warm summer evenings. There is more physic behind these little animals than anyone of us could imagine. In this paper we analyze from a physical point of view one structure found on the firefly lantern, the one which best improves light extraction. Moreover, simulations will be done to show why this specific structure may be more effective than a "human-thought" one.

  2. Pulsed Ultraviolet Light Reduces Immunoglobulin E Binding to Atlantic White Shrimp (Litopenaeus setiferus Extract

    Directory of Open Access Journals (Sweden)

    Si-Yin Chung

    2011-06-01

    Full Text Available Pulsed ultraviolet light (PUV, a novel food processing and preservation technology, has been shown to reduce allergen levels in peanut and soybean samples. In this study, the efficacy of using PUV to reduce the reactivity of the major shrimp allergen, tropomyosin (36-kDa, and to attenuate immunoglobulin E (IgE binding to shrimp extract was examined. Atlantic white shrimp (Litopenaeus setiferus extract was treated with PUV (3 pulses/s, 10 cm from light source for 4 min. Tropomyosin was compared in the untreated, boiled, PUV-treated and [boiled+PUV]-treated samples, and changes in the tropomyosin levels were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. IgE binding of the treated extract was analyzed via immunoblot and enzyme-linked immunosorbent assay (ELISA using pooled human plasma containing IgE antibodies against shrimp allergens. Results showed that levels of tropomyosin and IgE binding were reduced following PUV treatment. However, boiling increased IgE binding, while PUV treatment could offset the increased allergen reactivity caused by boiling. In conclusion, PUV treatment reduced the reactivity of the major shrimp allergen, tropomyosin, and decreased the IgE binding capacity of the shrimp extract.

  3. Pulsed ultraviolet light reduces immunoglobulin E binding to Atlantic white shrimp (Litopenaeus setiferus) extract.

    Science.gov (United States)

    Shriver, Sandra; Yang, Wade; Chung, Si-Yin; Percival, Susan

    2011-07-01

    Pulsed ultraviolet light (PUV), a novel food processing and preservation technology, has been shown to reduce allergen levels in peanut and soybean samples. In this study, the efficacy of using PUV to reduce the reactivity of the major shrimp allergen, tropomyosin (36-kDa), and to attenuate immunoglobulin E (IgE) binding to shrimp extract was examined. Atlantic white shrimp (Litopenaeus setiferus) extract was treated with PUV (3 pulses/s, 10 cm from light source) for 4 min. Tropomyosin was compared in the untreated, boiled, PUV-treated and [boiled+PUV]-treated samples, and changes in the tropomyosin levels were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). IgE binding of the treated extract was analyzed via immunoblot and enzyme-linked immunosorbent assay (ELISA) using pooled human plasma containing IgE antibodies against shrimp allergens. Results showed that levels of tropomyosin and IgE binding were reduced following PUV treatment. However, boiling increased IgE binding, while PUV treatment could offset the increased allergen reactivity caused by boiling. In conclusion, PUV treatment reduced the reactivity of the major shrimp allergen, tropomyosin, and decreased the IgE binding capacity of the shrimp extract.

  4. Effects of Curcuma extract and visible light on adults with plaque psoriasis.

    Science.gov (United States)

    Carrion-Gutierrez, Miguel; Ramirez-Bosca, Ana; Navarro-Lopez, Vicente; Martinez-Andres, Asunción; Asín-Llorca, Manuel; Bernd, August; Horga de la Parte, José Francisco

    2015-01-01

    We conducted a phase IV randomized, double-blind, placebo-controlled, pilot clinical trial to investigate the safety and efficacy of oral curcumin together with local phototherapy in patients with plaque psoriasis. Patients with moderate to severe psoriasis received Curcuma extract orally with real visible light phototherapy (VLRT) or simulated visible light phototherapy (VLST) in the experimental area, while the rest of the body surface was treated with ultraviolet A (UVA) radiation. The endpoints were the number of responders and the temporal course of the response. The secondary outcomes were related to safety and adverse events. Twenty-one patients were included in the study. In the intention-to-treat analysis, no patients included in the VLRT group showed "moderate" or "severe" plaques after the treatment, in contrast to the patients included in the VSLT group (pCurcuma if activated with visible light phototherapy, a new therapeutic method that would be safer for patients than existing treatments.

  5. Evaluation of the pH and thermal stabilities of rosella anthocyanin extracts under solar light

    Directory of Open Access Journals (Sweden)

    Kahtan A. Askar

    2015-09-01

    Full Text Available Anthocyanin is considered as an unstable pigment, undergoes gradual degradation processes throughout the storage or use. The degradation of Rosella anthocyanin extract (RAE in different pH solutions was studied under solar light and compared with solutions kept in the dark. It appears that RAE solutions under solar light were suffering rapid degradation than those kept in the dark. Moreover, RAE samples at higher pH values showed faster rates of degradation than those with lower pH values. A mechanism for degradation was suggested through the formation of hydroxyl radical which is responsible for demineralization process. It is also appears that as the initial concentration of the dye increases, the requirement needed for degradation increased as well. The thermal degradation behavior of RAE at temperature range 25–60 °C under solar light showed first order kinetics with low activation energies.

  6. Extraction of optical properties and prediction of light distribution in rat brain tissue

    Science.gov (United States)

    Azimipour, Mehdi; Baumgartner, Ryan; Liu, Yuming; Jacques, Steven L.; Eliceiri, Kevin; Pashaie, Ramin

    2014-07-01

    Predicting the distribution of light inside any turbid media, such as biological tissue, requires detailed information about the optical properties of the medium, including the absorption and scattering coefficients and the anisotropy factor. Particularly, in biophotonic applications where photons directly interact with the tissue, this information translates to system design optimization, precision in light delivery, and minimization of unintended consequences, such as phototoxicity or photobleaching. In recent years, optogenetics has opened up a new area in deep brain stimulation with light and the method is widely adapted by researchers for the study of the brain circuitries and the dynamics of neurological disorders. A key factor for a successful optogenetic stimulation is delivering an adequate amount of light to the targeted brain objects. The adequate amount of light needed to stimulate each brain object is identified by the tissue optical properties as well as the type of opsin expressed in the tissue, wavelength of the light, and the physical dimensions of the targeted area. Therefore, to implement a precise light delivery system for optogenetics, detailed information about the optical properties of the brain tissue and a mathematical model that incorporates all determining factors is needed to find a good estimation of light distribution in the brain. In general, three measurements are required to obtain the optical properties of any tissue, namely diffuse transmitted light, diffuse reflected light, and transmitted ballistic beam. In this report, these parameters were measured in vitro using intact rat brain slices of 500 μm thickness via a two-integrating spheres optical setup. Then, an inverse adding doubling method was used to extract the optical properties of the tissue from the collected data. These experiments were repeated to cover the whole brain tissue with high spatial resolution for the three different cuts (transverse, sagittal, and coronal

  7. Forming the graded-refractive-index antireflection layers on light-emitting diodes to enhance the light extraction.

    Science.gov (United States)

    Cho, Joong-Yeon; Byeon, Kyeong-Jae; Lee, Heon

    2011-08-15

    Distributed antireflection (AR) layers with different composition ratios of ITO and SiO(2) formed on an ITO electrode of GaN-based LEDs provide substantial enhancement in light-extraction efficiency. By using the coradio frequency magnetron sputtering deposition, four 50 nm thick AR layers with graduated refractive indices were fabricated. The effect of the AR layers on enhancing the efficiency of the LED device was analyzed by electroluminescence (EL) and I-V measurements. As a result, the EL intensity of the LED device grown on the patterned sapphire substrate with AR layers was increased by up to 13% compared to the conventional patterned sapphire substrate-applied LED device without AR layers at a drive current of 20 mA. The AR layers on top of the LED device gradually changed the refractive indices between ITO (n=2.1) and air (n=1.0), which minimized the total internal reflection of generated light. And no degradation in the electrical characteristic of the LEDs was observed according to the I-V measurements.

  8. EXTRACTING PERIODIC TRANSIT SIGNALS FROM NOISY LIGHT CURVES USING FOURIER SERIES

    Energy Technology Data Exchange (ETDEWEB)

    Samsing, Johan [Department of Astrophysical Sciences, Princeton University, Peyton Hall, 4 Ivy Lane, Princeton, NJ 08544 (United States)

    2015-07-01

    We present a simple and powerful method for extracting transit signals associated with a known transiting planet from noisy light curves. Assuming the orbital period of the planet is known and the signal is periodic, we illustrate that systematic noise can be removed in Fourier space at all frequencies by only using data within a fixed time frame with a width equal to an integer number of orbital periods. This results in a reconstruction of the full transit signal, which on average is unbiased despite no prior knowledge of either the noise or the transit signal itself being used in the analysis. The method therefore has clear advantages over standard phase folding, which normally requires external input such as nearby stars or noise models for removing systematic components. In addition, we can extract the full orbital transit signal (360°) simultaneously, and Kepler-like data can be analyzed in just a few seconds. We illustrate the performance of our method by applying it to a dataset composed of light curves from Kepler with a fake injected signal emulating a planet with rings. For extracting periodic transit signals, our presented method is in general the optimal and least biased estimator and could therefore lead the way toward the first detections of, e.g., planet rings and exo-trojan asteroids.

  9. Commercial Light Water Reactor -Tritium Extraction Facility Process Waste Assessment (Project S-6091)

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, R.H.; Delley, A.O.; Alexander, G.J.; Clark, E.A.; Holder, J.S.; Lutz, R.N.; Malstrom, R.A.; Nobles, B.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Carson, S.D. [Sandia National Laboratories, New Mexico, NM (United States); Peterson, P.K. [Sandia National Laboratories, New Mexico, NM (United States)

    1997-11-30

    The Savannah River Site (SRS) has been tasked by the Department of Energy (DOE) to design and construct a Tritium Extraction Facility (TEF) to process irradiated tritium producing burnable absorber rods (TPBARs) from a Commercial Light Water Reactor (CLWR). The plan is for the CLWR-TEF to provide tritium to the SRS Replacement Tritium Facility (RTF) in Building 233-H in support of DOE requirements. The CLWR-TEF is being designed to provide 3 kg of new tritium per year, from TPBARS and other sources of tritium (Ref. 1-4).The CLWR TPBAR concept is being developed by Pacific Northwest National Laboratory (PNNL). The TPBAR assemblies will be irradiated in a Commercial Utility light water nuclear reactor and transported to the SRS for tritium extraction and processing at the CLWR-TEF. A Conceptual Design Report for the CLWR-TEF Project was issued in July 1997 (Ref. 4).The scope of this Process Waste Assessment (PWA) will be limited to CLWR-TEF processing of CLWR irradiated TPBARs. Although the CLWR- TEF will also be designed to extract APT tritium-containing materials, they will be excluded at this time to facilitate timely development of this PWA. As with any process, CLWR-TEF waste stream characteristics will depend on process feedstock and contaminant sources. If irradiated APT tritium-containing materials are to be processed in the CLWR-TEF, this PWA should be revised to reflect the introduction of this contaminant source term.

  10. submitter Light Extraction From Scintillating Crystals Enhanced by Photonic Crystal Structures Patterned by Focused Ion Beam

    CERN Document Server

    Modrzynski, Pawel; Knapitsch, Arno; Kunicki, Piotr; Lecoq, Paul; Moczala, Magdalena; Papakonstantinou, Ioannis; Auffray, Etiennette

    2016-01-01

    “Photonic Crystals (PhC)” have been used in a variety of fields as a structure for improving the light extraction efficiency from materials with high index of refraction. In previous work we already showed the light extraction improvement of several PhC covered LYSO crystals in computer simulations and practical measurements. In this work, new samples are made using different materials and techniques which allows further efficiency improvements. For rapid prototyping of PhC patterns on scintillators we tested a new method using “Focused Ion Beam (FIB)” patterning. The FIB machine is a device similar to a “Scanning Electron Microscope (SEM)”, but it uses ions (mainly gallium) instead of electrons for the imaging of the samples' surface. The additional feature of FIB devices is the option of surface patterning in nano-scale which was exploited for our samples. Three samples using FIB patterning have been produced. One of them is a direct patterning of the extraction face of a 0.8×0.8×10 $mm^3$ LYS...

  11. Enhancement of near-UV GaN LED light extraction efficiency by GaN/sapphire template patterning

    Science.gov (United States)

    Ali, M.; Svensk, O.; Riuttanen, L.; Kruse, M.; Suihkonen, S.; Romanov, A. E.; Törmä, P. T.; Sopanen, M.; Lipsanen, H.; Odnoblyudov, M. A.; Bougrov, V. E.

    2012-08-01

    We present near-UV GaN light-emitting diodes (LEDs) grown on patterned GaN/sapphire templates with improved material quality and light extraction efficiency. Enhancement of light extraction efficiency is attributed to voids generated at the GaN/sapphire interface. The sidewall inclination angle of the voids can be controlled from nearly vertical (˜ 85°) to fully inclined (˜ 60°) by changing the initial patterning dimensions. Light extraction efficiency and material quality improve with a decreasing void sidewall angle. A 20% increase in the light output is observed at 20 mA of input current for LED structures with ˜60° inclined sidewall voids.

  12. Improved light extraction in the bioluminescent lantern of a Photuris firefly (Lampyridae)

    CERN Document Server

    Bay, Annick; Suhonen, Heikki; Vigneron, Jean Pol

    2012-01-01

    A common problem of light sources emitting from an homogeneous high-refractive index medium into air is the loss of photons by total internal reflection. Bioluminescent organisms, as well as artificial devices, have to face this problem. It is expected that life, with its mechanisms for evolution, would have selected appropriate optical structures to get around this problem, at least partially. The morphology of the lantern of a specific firefly in the genus Photuris has been examined. The optical properties of the different parts of this lantern have been modelled, in order to determine their positive or adverse effect with regard to the global light extraction. We conclude that the most efficient pieces of the lantern structure are the misfit of the external scales (which produce abrupt roughness in air) and the lowering of the refractive index at the level of the cluster of photocytes, where the bioluminescent production takes place.

  13. Improved light extraction in the bioluminescent lantern of a Photuris firefly (Lampyridae)

    Science.gov (United States)

    Bay, Annick; Cloetens, Peter; Suhonen, Heikki; Vigneron, Jean Pol

    2013-01-01

    A common problem of light sources emitting from an homogeneous high-refractive index medium into air is the loss of photons by total internal reflection. Bioluminescent organisms, as well as artificial devices, have to face this problem. It is expected that life, with its mechanisms for evolution, would have selected appropriate optical structures to get around this problem, at least partially. The morphology of the lantern of a specific firefly in the genus Photuris has been examined. The optical properties of the different parts of this lantern have been modeled, in order to determine their positive or adverse effect with regard to the global light extraction. We conclude that the most efficient pieces of the lantern structure are the misfit of the external scales (which produce abrupt roughness in air) and the lowering of the refractive index at the level of the cluster of photocytes, where the bioluminescent production takes place.

  14. Light extraction enhancement of SOI-based erbium/oxygen Co-implanted photonic crystal microcavities

    Institute of Scientific and Technical Information of China (English)

    Zhang Jiashun; Wang Yue; Wu Yuanda; Zhang Xiaoguang; Jiang Ting; An Junming; Li Jianguang; Wang Hongjie; Hu Xiongwei

    2011-01-01

    H5 photonic crystal (PC) microcavities co-implanted with erbium (Er) and oxygen (O) ions were fabricated on silicon-on-insulator (SOI) wafers.Photoluminescence (PL) measurements were taken at room temperature and a light extraction enhancement of up to 12 was obtained at 1.54μm,as compared to an identically implanted unpatterned SOI wafer.In addition,we also explored the adjustment of cavity modes by changing the structural parameters of the PC,and the measured results showed that the cavity-resonant peaks shifted towards shorter wavelengths as the radius of the air holes increased,which is consistent with the theoretical simulation.

  15. Enhancement of light extraction based on nanowire hyperbolic metamaterials in a grating structure

    Science.gov (United States)

    Kao, Tzu-Hung; Hung, Yu-Chueh

    2016-04-01

    Hyperbolic metamaterial (HMM) has attracted considerable attention owing to several exotic optical properties, including negative refraction, enhanced spontaneous emission, and subwavelength imaging. The hyperbolic dispersion of HMMs increases photonic density of states in a broad bandwidth, leading to enhancement of spontaneous emission. However, the out-coupling of light from HMMs is difficult due to the evanescent character of the high-k modes at the surface. In this study, we implement the full-field numerical calculations based on finite-difference time-domain (FDTD) method to characterize the optical properties of nanowire HMMs embedded in a grating structure. We first examined the power spectrum of the nanowire HMMs. The Purcell factor and the light enhancement are also analyzed. Furthermore, to examine the out-coupling of light by virtue of the periodic structure, the Purcell factor and enhancement of light extraction efficiency of the hybrid structure will be examined and discussed. The analysis result is important toward engineering highly-efficient photonic devices based on HMMs.

  16. Device reflectivity as a simple rule for predicting the suitability of scattering foils for improved OLED light extraction

    NARCIS (Netherlands)

    Levell, J.W.; Harkema, S.; Pendyala, R.K.; Rensing, P.A.; Senes, A.; Bollen, D.; MacKerron, D.; Wilson, J.S.

    2013-01-01

    A general challenge in Organic Light Emitting Diodes (OLEDs) is to extract the light efficiently from waveguided modes within the device structure. This can be accomplished by applying an additional scattering layer to the substrate which results in outcoupling increases between 0% to <100% in exter

  17. Lethal effects of the insect growth regulator cyromazine against three species of filth flies, Musca domestica L., Stomoxys calcitrans (L.), and Fannia canicularis (L.) (Diptera: Muscidae) in cattle, swine, and chicken manure

    Science.gov (United States)

    Various species of so-called filth flies are a widespread problem where livestock, including poultry, is maintained and where manure accumulates. The house fly, Musca domestica L.; the stable fly, Stomoxys calcitrans (L.); and the little house fly, Fannia canicularis (L.) (each Diptera: Muscidae), t...

  18. Improving Light Extraction of Organic Light-Emitting Devices by Attaching Nanostructures with Self-Assembled Photonic Crystal Patterns

    Directory of Open Access Journals (Sweden)

    Kai-Yu Peng

    2014-01-01

    Full Text Available A single-monolayered hexagonal self-assembled photonic crystal (PC pattern fabricated onto polyethylene terephthalate (PET films by using simple nanosphere lithography (NSL method has been demonstrated in this research work. The patterned nanostructures acted as a scattering medium to extract the trapped photons from substrate mode of optical-electronic device for improving the overall external quantum efficiency of the organic light-emitting diodes (OLEDs. With an optimum latex concentration, the distribution of self-assembled polystyrene (PS nanosphere patterns on PET films can be easily controlled by adjusting the rotation speed of spin-coater. After attaching the PS nanosphere array brightness enhancement film (BEF sheet as a photonic crystal pattern onto the device, the luminous intensity of OLEDs in the normal viewing direction is 161% higher than the one without any BEF attachment. The electroluminescent (EL spectrum of OLEDs with PS patterned BEF attachment also showed minor color offset and superior color stabilization characteristics, and thus it possessed the potential applications in all kinds of display technology and solid-state optical-electronic devices.

  19. Selected phytotoxins and organic extracts from endophytic fungus Edenia gomezpompae as light reaction of photosynthesis inhibitors.

    Science.gov (United States)

    Macías-Rubalcava, Martha Lydia; Ruiz-Velasco Sobrino, María Emma; Meléndez-González, Claudio; King-Díaz, Beatriz; Lotina-Hennsen, Blas

    2014-09-05

    In a search for natural herbicides, we investigated the action mechanism of the naphthoquinone spiroketals, isolated from the endophytic fungus Edenia gomezpompae: preussomerins EG1 (1) and EG4 (2), and palmarumycins CP17 (3), and CP2 (4) on the photosynthesis light reactions. The naphthoquinone spiroketals 1-4 inhibited the ATP synthesis in freshly lysed spinach thylakoids from water to MV, and they also inhibited the non-cyclic electron transport in the basal, phosphorylating and uncoupled conditions from water to MV. Therefore, they act as Hill reaction inhibitors. The results suggested that naphthoquinone spiroketals 1-4 have two interactions and inhibition site on the PSII electron transport chain. The first one involves the water splitting enzyme inhibition; and, the second on the acceptor site of PSII in a similar way that herbicide Diuron, studied by polaroghaphy and corroborated by fluorescence of the chlorophyll a of PSII. The culture medium and mycelium organic extracts from four morphological variants of E. gomezpompae were phytotoxic, and the culture medium extracts were more potent than mycelium extracts. They also act as Hill reaction inhibitors. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Improved light extraction of LYSO scintillator by the photonic structure from a layer of anodized aluminum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zhichao [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Liu, Bo, E-mail: lbo@tongji.edu.cn [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Cheng, Chuanwei; Zhang, Haifeng; Wu, Shuang; Gu, Mu; Chen, Hong [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Chen, Liang; Liu, Jinliang; Ouyang, Xiaoping [Northwest Institute of Nuclear Technology, Xi’an 710024 (China)

    2015-06-21

    As a promising scintillator in the field of medical imaging systems, LYSO with its high refractive index suffers from a low light extraction efficiency due to the total internal reflection. Here, we demonstrate that a photonic structure formed by an anodized aluminum oxide layer can enhance the light extraction efficiency by the outcoupling the light trapped in the crystal. An enhancement of light output by 25% can be achieved by an AAO layer covered on the surface of LYSO. The imperfect periodicity of AAO can lead to a consistent enhancement for the entire range of emission wavelength and directionality. Such enhanced light output is practical and attractive for use in the scintillation detection systems. It is important to note that the fabrication method of AAO is simple and low-cost for the large area applications, which is obviously advantageous over the expensive traditional methods such as electron beam lithography.

  1. Improvement of Light Extraction Efficiency in Flip-Chip Light Emitting Diodes on SiC Substrate via Transparent Haze Films with Morphology-Controlled Collapsed Alumina Nanorods.

    Science.gov (United States)

    Baek, Seunghwa; Kang, Gumin; Shin, Dongheok; Bae, Kyuyoung; Kim, Yong Hyun; Kim, Kyoungsik

    2016-01-13

    We demonstrate GaN-based flip-chip light emitting diodes (FC-LEDs) on SiC substrate achieving high extraction efficiency by simply attaching the optically transparent haze films consisting of collapsed alumina nanorods. Through controlled etching time of alumina nanorods, we obtain four types of films that have different morphologies with different optical transmittance and haze properties. We show that the light output power of the FC-LEDs with film, which has 95.6% transmittance and 62.7% haze, increases by 20.4% in comparison to the bare LEDs. The angular radiation pattern of the LEDs also follows the Lambertian emission pattern without deteriorating the electrical properties of the device. The improvement of light extraction is mainly attributed to the reduced total internal reflection (TIR) via efficient out-coupling of guided light from SiC substrate to air by collapsed alumina nanorod structures in the film. The high transparency of film and reduced Fresnel reflection via graded refractive index transition between the film and SiC substrate also contribute to the extraction enhancement of the device. We systematically investigate the influence of haze film's geometrical or optical properties on the extraction efficiency of FC-LEDs, and this study will provide a novel approach to enhance the performance of various optoelectronic devices.

  2. Extracting α{sub s} from scaling violations in light-hadron fragmentation functions

    Energy Technology Data Exchange (ETDEWEB)

    Kniehl, Bernd A. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

    2015-11-15

    We review the status of extracting the strong-coupling constant α{sub s} from the scaling violations in fragmentation functions by fitting the latter to experimental data of the inclusive production of single light hadrons in e{sup +}e{sup -} annihilation. We also discuss the analogous analysis based on the average hadron multiplicities in gluon and quark jets, which correspond to the first Mellin moments of the respective FFs. We then assess the prospects of such α{sub s} determinations at future high-luminosity e{sup +}e{sup -} colliders such as the CERN Future Circular Collider operated in the e{sup +}e{sup -} annihilation mode (FCC-ee).

  3. Electromagnetic Coupling Between High Intensity LHC Beams and the Synchrotron Radiation Monitor Light Extraction System

    CERN Document Server

    Andreazza, W; Bravin, E; Caspers, F; Garlasch`e, M; Gras, J; Goldblatt, A; Lefevre, T; Jones, R; Metral, E; Nosych, A; Roncarolo_, F; Salvant, B; Trad, G; Veness, R; Vollinger, C; Wendt, M

    2013-01-01

    The CERN LHC is equipped with two Synchrotron Radiation Monitor (BSRT) systems used to characterise transverse and longitudinal beam distributions. Since the end of the 2011 LHC run the light extraction system, based on a retractable mirror, has suffered deformation and mechanical failure that is correlated to the increase in beam intensity. Temperature probes have associated these observations to a strong heating of the mirror support with a dependence on the longitudinal bunch length and shape, indicating the origin as electromagnetic coupling between the beam and the structure. This paper combines all this information with the aim of characterising and improving the system in view of its upgrade during the current LHC shutdown. Beam-based observations are presented along with electromagnetic and thermomechanical simulations and complemented by laboratory measurements, including the study of the RF properties of different mirror bulk and coating materials.

  4. Automated bare earth extraction technique for complex topography in light detection and ranging surveys

    Science.gov (United States)

    Stevenson, Terry H.; Magruder, Lori A.; Neuenschwander, Amy L.; Bradford, Brian

    2013-01-01

    Bare earth extraction is an important component to light detection and ranging (LiDAR) data analysis in terms of terrain classification. The challenge in providing accurate digital surface models is augmented when there is diverse topography within the data set or complex combinations of vegetation and built structures. Few existing algorithms can handle substantial terrain diversity without significant editing or user interaction. This effort presents a newly developed methodology that provides a flexible, adaptable tool capable of integrating multiple LiDAR data attributes for an accurate terrain assessment. The terrain extraction and segmentation (TEXAS) approach uses a third-order spatial derivative for each point in the digital surface model to determine the curvature of the terrain rather than rely solely on the slope. The utilization of the curvature has shown to successfully preserve ground points in areas of steep terrain as they typically exhibit low curvature. Within the framework of TEXAS, the contiguous sets of points with low curvatures are grouped into regions using an edge-based segmentation method. The process does not require any user inputs and is completely data driven. This technique was tested on a variety of existing LiDAR surveys, each with varying levels of topographic complexity.

  5. Increasing the extraction efficiency of blue light emitting diodes via laser patterned Ga-polar p-GaN surface

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Zhiyuan; Liu, Duo; Zhang, Baitao; He, Jingliang; Liu, Hong; Xu, Xiangang [State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100 (China)

    2011-09-15

    We report here the laser patterned Ga-polar p-GaN surface to improve the light extraction efficiency of GaN based blue light emitting diodes (LEDs) by using a pulsed UV laser in combination with a mirror scanner. The patterns created on p-GaN are confirmed to be suitable for light extraction and a 34.9% enhancement of the electroluminescent (EL) emission intensity has been obtained. Detailed discussions on the effects of laser on LEDs and the angular dependence of the emission profile are also provided. This method could be extended to other III-V LEDs and LEDs on SiC for fabricating highly efficient LEDs. The schematic of laser fabrication equipment, SEM image of patterned p-GaN surface and guided-modes extraction photograph of patterned GaN epilayer. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Influence of the microstructure geometry of patterned sapphire substrates on the light extraction efficiency of GaN LEDs.

    Science.gov (United States)

    Kuo, Chien-Ting; Hsu, Lung-Hsing; Huang, Bo-Hsin; Kuo, Hao-Chung; Lin, Chien-Chung; Cheng, Yuh-Jen

    2016-09-10

    The influence of the microstructure geometry of patterned sapphire substrates (PSS) on the light extraction efficiency (LEE) of GaN light-emitting diodes (LEDs) is numerically analyzed. Cone structures of various dimensions are studied, along with dome and mixed microstructures. LEE is found to mainly depend on the microstructure surface slope. LEE rises quickly with slope and flattens out when the slope exceeds 0.6. Scaling down the microstructure has little effect on LEE. Light rays are found to travel longer distances in PSS LEDs, as compared with LEDs grown on a flat substrate. Keeping GaN absorption loss low is important for LEE optimization.

  7. Lighting

    Data.gov (United States)

    Federal Laboratory Consortium — Lighting Systems Test Facilities aid research that improves the energy efficiency of lighting systems. • Gonio-Photometer: Measures illuminance from each portion of...

  8. Antioxidant properties of green tea extract protect reduced fat soft cheese against oxidation induced by light exposure

    DEFF Research Database (Denmark)

    Huvaere, Kevin; Nielsen, Jacob Holm; Bakman, Mette

    2011-01-01

    The effect of two different antioxidants, EDTA and green tea extract (GTE), used individually or in combination, on the light-induced oxidation of reduced fat soft cheeses (0.2 and 6% fat) was investigated. In samples with 0.2% fat, lipid hydroperoxides as primary lipid oxidation products were...

  9. Enhanced light extraction efficiency of plastic scintillator by photonic crystal prepared with a self-assembly method

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jinliang [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi’an, 710024 (China); Zhu, Zhichao [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Chen, Liang; Ouyang, Xiaoping [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi’an, 710024 (China); Liu, Bo, E-mail: lbo@tongji.edu.cn [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Cheng, Chuanwei [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Hu, Jing; He, Shiyi [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi’an, 710024 (China); Wang, Zewei [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Radiation Detection Research Center, Northwest Institute of Nuclear Technology, Xi’an, 710024 (China); College of Materials Science and Engineering, Xiangtan University, Xiangtan 411105 (China); Gu, Mu; Chen, Hong [Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China)

    2015-09-21

    Plastic scintillators are extensively used in various radiation measurement systems. However the total internal reflection decreases the scintillation light output, leading to a low detection efficiency especially in these weak signal detection situations. In the present investigation, we have designed a light extraction scheme based on the photonic crystal formed with a monolayer periodic array of polystyrene nanospheres by a self-assembly method. The photonic crystal coated on the surface of plastic scintillator can significantly enhance the light extraction by 120% compared with the plain reference sample under X-ray excitation, which is achieved by the principle of the coupling of evanescent field near the scintillator-air interface with the photonic crystal.

  10. Two-color light-emitting diodes with polarization-sensitive high extraction efficiency based on graphene

    Science.gov (United States)

    H, Sattarian; S, Shojaei; E, Darabi

    2016-05-01

    In the present study, graphene photonic crystals are employed to enhance the light extraction efficiency (LEE) of two-color, red and blue, light-emitting diode (LED). The transmission characteristics of one-dimensional (1D) Fibonacci graphene photonic crystal LED (FGPC-LED) are investigated by using the transfer matrix method and the scaling study is presented. We analyzed the influence of period, thickness, and permittivity in the structure to enhance the LEE. The transmission spectrum of 1D FGPC has been optimized in detail. In addition, the effects of the angle of incidence and the state of polarization are investigated. As the main result, we found the optimum values of relevant parameters to enhance the extraction of red and blue light from an LED as well as provide perfect omnidirectional and high peak transmission filters for the TE and TM modes.

  11. Light extraction enhancement with radiation pattern shaping of LEDs by waveguiding nanorods with impedance-matching tips.

    Science.gov (United States)

    Hsiao, Yu-Hsuan; Chen, Cheng-Ying; Huang, Li-Chuan; Lin, Guan-Jhong; Lien, Der-Hsien; Huang, Jian-Jang; He, Jr-Hau

    2014-03-07

    Syringe-like ZnO nanorods (NRs) were fabricated on InGaN/GaN light emitting diodes (LEDs) by a hydrothermal method. Without sacrificing the electrical performances of LEDs, syringe-like NRs can enhance light extraction capability by 10.5% at 20 mA and shape the radiation profile with a view angle collimated from 136° to 121°. By performing optical experiments and simulation, it is found that the superior light extraction efficiency with a more collimated radiation pattern is attributed to the waveguiding effect of NRs and the mitigation of abrupt index change by the tapered ends of syringe-like ZnO NRs. This work demonstrates the importance of the nanostructure morphology in LED performances and provides the architecture design guidelines of nanostructures to a variety of optical devices.

  12. Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclay.

    Science.gov (United States)

    Delferrière, O; Gobin, R; Harrault, F; Nyckees, S; Sauce, Y; Tuske, O

    2012-02-01

    One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

  13. Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclaya)

    Science.gov (United States)

    Delferrière, O.; Gobin, R.; Harrault, F.; Nyckees, S.; Sauce, Y.; Tuske, O.

    2012-02-01

    One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT.

  14. Light

    DEFF Research Database (Denmark)

    Prescott, N.B.; Kristensen, Helle Halkjær; Wathes, C.M.

    2004-01-01

    This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality......This chapter presents the effect of artificial light environments (light levels, colour, photoperiod and flicker) on the welfare of broilers in terms of vision, behaviour, lameness and mortality...

  15. Nanostructural Effect of ZnO on Light Extraction Efficiency of Near-Ultraviolet Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Young Jae Park

    2016-01-01

    Full Text Available The effect of ZnO nanostructures on the light output power of 375 nm near-ultraviolet light-emitting diodes (NUV-LEDs was investigated by comparing one-dimensional (1D nanorods (NR-ZnO with two-dimensional (2D nanosheets (NS-ZnO. ZnO nanostructures were grown on a planar indium tin oxide (ITO by solution based method at low temperature of 90°C without degradation of the forward voltage. At an injection current of 100 mA, the light output efficiency of NUV-LED with NR-ZnO was enhanced by around 30% compared to the conventional NUV-LEDs without ZnO nanostructures. This improvement is due to the formation of a surface texturing, resulting in a larger escape cone and a multiple scattering for the photons in the NUV-LED, whereas the light output efficiency of NUV-LED with NS-ZnO was lower than that of the conventional NUV-LEDs due to the internal reflection and light absorption in the defective sites of NS-ZnO.

  16. Protective effects of bilberry and lingonberry extracts against blue light-emitting diode light-induced retinal photoreceptor cell damage in vitro.

    Science.gov (United States)

    Ogawa, Kenjirou; Kuse, Yoshiki; Tsuruma, Kazuhiro; Kobayashi, Saori; Shimazawa, Masamitsu; Hara, Hideaki

    2014-04-02

    Blue light is a high-energy or short-wavelength visible light, which induces retinal diseases such as age-related macular degeneration and retinitis pigmentosa. Bilberry (Vaccinium myrtillus L.) and lingonberry (Vaccinium vitis-idaea) contain high amounts of polyphenols (anthocyanins, resveratrol, and proanthocyanidins) and thus confer health benefits. This study aimed to determine the protective effects and mechanism of action of bilberry extract (B-ext) and lingonberry extract (L-ext) and their active components against blue light-emitting diode (LED) light-induced retinal photoreceptor cell damage. Cultured murine photoreceptor (661 W) cells were exposed to blue LED light following treatment with B-ext, L-ext, or their constituents (cyanidin, delphinidin, malvidin, trans-resveratrol, and procyanidin B2). 661 W cell viability was assessed using a tetrazolium salt (WST-8) assay and Hoechst 33342 nuclear staining, and intracellular reactive oxygen species (ROS) production was determined using CM-H2DCFDA after blue LED light exposure. Activation of p38 mitogen-activated protein kinase (p38 MAPK), nuclear factor-kappa B (NF-κB), and LC3, an ubiquitin-like protein that is necessary for the formation of autophagosomes, were analyzed using Western blotting. Caspase-3/7 activation caused by blue LED light exposure in 661 W cells was determined using a caspase-3/7 assay kit. B-ext, L-ext, NAC, and their active components improved the viability of 661 W cells and inhibited the generation of intracellular ROS induced by blue LED light irradiation. Furthermore, B-ext and L-ext inhibited the activation of p38 MAPK and NF-κB induced by blue LED light exposure. Finally, B-ext, L-ext, and NAC inhibited caspase-3/7 activation and autophagy. These findings suggest that B-ext and L-ext containing high amounts of polyphenols exert protective effects against blue LED light-induced retinal photoreceptor cell damage mainly through inhibition of ROS production and activation of

  17. Light extraction improvement of InGaN light-emitting diodes with large-area highly ordered ITO nanobowls photonic crystal via self-assembled nanosphere lithography

    Directory of Open Access Journals (Sweden)

    Kui Wu

    2013-09-01

    Full Text Available The InGaN multiple quantum well light-emitting diodes (LEDs with different sizes of indium-tin-oxide (ITO nanobowl photonic crystal (PhC structure has been fabricated using self-assembled monolayer nanosphere lithography. The light output power (LOP of PhC LEDs (at 350 mA has been enhanced by 63.5% and the emission divergence exhibits a 28.8° reduction compared to conventional LEDs without PhC structure. Current-Voltage curves have shown that these PhC structures on ITO layer will not degrade the LED electrical properties. The finite-difference time-domain simulation (FDTD has also been performed for light extraction and emission characteristics, which is consistent with the experimental results.

  18. Influence of Size of ZnO Nanorods on Light Extraction Enhancement of GaN-Based Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    DAI Ke-Hui; WANG Lian-Shan; HUANG De-Xiu; SOH Chew-Beng; CHUA Soo-Jin

    2011-01-01

    We investigate the influence of size of ZnO nanorods on the light extraction efficiency (LEE) enhancement of GaN-based light-emitting diodes (GaN-LEDs). ZnO nanorods with different sizes are hydrothermally grown on patterned indium-doped tin oxide (ITO) electrodes of the GaN-LEDs in zinc acetate aqueous solutions of different concentrations. Measurements are conducted for the LEE enhancement of the LEDs with ZnO nanorods, compared to these without ZnO nanorods. The results suggest that the LEE of the LEDs with ZnO nanorods increases with the increasing size of ZnO nanorods. However, a saturation trend for the LEE improvement is also observed, which is attributed to the maximum limitation of light coupled into ZnO nanorods from GaN-based LEDs, and the reflection is increased by the increasing top surface of the ZnO nanorods.%@@ We investigate the influence of size of ZnO nanorods on the light extraction efficiency(LEE)enhancement of GaN-based light-emitting diodes(GaN-LEDs).ZnO nanorods with different sizes are hydrothermally grown on patterned indium-doped tin oxide(ITO)electrodes of the GaN-LEDs in zinc acetate aqueous solutions of different concentrations.Measurements are conducted for the LEE enhancement of the LEDs with ZnO nanorods,compared to these without ZnO nanorods.The results suggest that the LEE of the LEDs with ZnO nanorods increases with the increasing size of ZnO nanorods.However,a saturation trend for the LEE improvement is also observed,which is attributed to the maximum limitation of light coupled into ZnO nanorods from GaN-based LEDs,and the reflection is increased by the increasing top surface of the ZnO nanorods.

  19. Enhancing the Light-Extraction Efficiency of AlGaN Nanowires Ultraviolet Light-Emitting Diode by using Nitride/Air Distributed Bragg Reflector Nanogratings

    KAUST Repository

    Alias, Mohd Sharizal

    2017-09-11

    The performance and efficiency of AlGaN ultraviolet light-emitting diodes have been limited by the extremely low light-extraction efficiency (LEE) due to the intrinsic material properties of AlGaN. Here, to enhance the LEE of the device, we demonstrate an AlGaN nanowires light-emitting diode (NWs-LED) integrated with nitride/air Distributed Bragg Reflector (DBR) nanogratings. Compared to a control device (only mesa), the AlGaN NWs-LED with the nitride/air DBR nanogratings exhibit enhancement in the light output power and external quantum efficiency (EQE) by a factor of ∼1.67. The higher light output power and EQE are attributed mainly to the multiple reflectances laterally for the transverse magnetic (TM)-polarized light and scattering introduced by the nanogratings. To further understand the LEE enhancement, the electrical field distribution, extraction ratio and polar pattern of the AlGaN NWs-LED with and without the nitride/air DBR nanogratings were analyzed using the finite-difference-time-domain method. It was observed that the TM-field emission was confined and scattered upward whereas the polar pattern was intensified for the AlGaN NWs-LED with the nanogratings. Our approach to enhance the LEE via the nitride/air DBR nanogratings can provide a promising route for increasing the efficiency of AlGaN-based LEDs, also, to functioning as facet mirror for AlGaN-based laser diodes.

  20. Light-Emitting Diodes with Hierarchical and Multifunctional Surface Structures for High Light Extraction and an Antifouling Effect.

    Science.gov (United States)

    Leem, Young-Chul; Park, Jung Su; Kim, Joon Heon; Myoung, NoSoung; Yim, Sang-Youp; Jeong, Sehee; Lim, Wantae; Kim, Sung-Tae; Park, Seong-Ju

    2016-01-13

    Bioinspired hierarchical structures on the surface of vertical light-emitting diodes (VLEDs) are demonstrated by combining a self-assembled dip-coating process and nanopatterning transfer method using thermal release tape. This versatile surface structure can efficiently reduce the total internal reflection and add functions, such as superhydrophobicity and high oleophobicity, to achieve an antifouling effect for VLEDs.

  1. Enhanced Extraction of Silicon-Vacancy Centers Light Emission Using Bottom-Up Engineered Polycrystalline Diamond Photonic Crystal Slabs.

    Science.gov (United States)

    Ondič, Lukáš; Varga, Marian; Hruška, Karel; Fait, Jan; Kapusta, Peter

    2017-03-28

    Silicon vacancy (SiV) centers are optically active defects in diamond. The SiV centers, in contrast to nitrogen vacancy (NV) centers, possess narrow and efficient luminescence spectrum (centered at ≈738 nm) even at room temperature, which can be utilized for quantum photonics and sensing applications. However, most of light generated in diamond is trapped in the material due to the phenomenon of total internal reflection. In order to overcome this issue, we have prepared two-dimensional photonic crystal slabs from polycrystalline diamond thin layers with high density of SiV centers employing bottom-up growth on quartz templates. We have shown that the spectral overlap between the narrow light emission of the SiV centers and the leaky modes extracting the emission into almost vertical direction (where it can be easily detected) can be obtained by controlling the deposition time. More than 14-fold extraction enhancement of the SiV centers photoluminescence was achieved compared to an uncorrugated sample. Computer simulation confirmed that the extraction enhancement originates from the efficient light-matter interaction between light emitted from the SiV centers and the photonic crystal slab.

  2. Fabrication of Light Extraction Efficiency of Organic Light-Emitting Diodes with 3D Aspherical Microlens by Using Dry Etching Process

    Directory of Open Access Journals (Sweden)

    Y. C. Chen

    2013-01-01

    Full Text Available organic light-emitting diode (OLED can enable a greater artificial contrast ratio and viewing angle compared to liquid crystal display (LCD because OLED pixels directly emit light. There is a shortcoming that the internal quantum efficiency can reach values close to 100%, but about 80% light disperses because of the difference among the refractive indices of the substrate, anode, indium tin oxide (ITO film, and air. In this paper, three dimensions aspherical microlens arrays (3D A-MLAs with substrate modifications are developed to simulate the optical luminous field by using FRED software. This study modified parameters of 3D A-MLAs such as the diameter, fill-factor, aspect ratio, dry etching parameters, and electroforming rates of microlens to improve the extraction efficiency of the OLED. In dry etching, not only the aspect ratio with better extraction rate can be obtained by reactive ion etching (RIE dry etching, but also an undercutting phenomenon can be avoided. The dimensions of 3D A-MLAs can be accurately controlled in the electroforming process used to make a nickel-cobalt (Ni-Co metal mold to achieve the designed dimensions. According to the measured results, the average luminance efficacy of the OLEDs with 3D A-MLAs can be enhanced.

  3. 150 mW deep-ultraviolet light-emitting diodes with large-area AlN nanophotonic light-extraction structure emitting at 265 nm

    Science.gov (United States)

    Inoue, Shin-ichiro; Tamari, Naoki; Taniguchi, Manabu

    2017-04-01

    High-power 265 nm deep-ultraviolet (DUV) AlGaN-based light-emitting diodes (LEDs) with large-area AlN nanophotonic light-extraction structures that were fabricated by a nanoimprint lithography process are presented. Each DUV-LED has a large active area (mesa size of ˜0.35 mm2) and a uniform current spreading design that allows high injection current operation. We have shown that these DUV-LEDs with their large-area nanoimprinted AlN nanophotonic structures exhibit wider near-field emitting areas, stronger far-field extracted light intensities, and an approximately 20-fold increase in output power when compared with a conventional flat-surface DUV-LED. A large-area nanoimprinted single-chip DUV-LED operating in the UV-C wavelength regime has demonstrated a record continuous-wave output power in excess of 150 mW for an injection current of 850 mA at a peak emission wavelength of 265 nm.

  4. Kepler Eclipsing Binary Stars. VIII. Identification of False Positive Eclipsing Binaries and Re-extraction of New Light Curves

    CERN Document Server

    Abdul-Masih, Michael; Conroy, Kyle; Bloemen, Steven; Boyajian, Tabetha; Doyle, Laurance R; Johnston, Cole; Kostov, Veselin; Latham, David W; Matijevic, Gal; Shporer, Avi; Southworth, John

    2016-01-01

    The Kepler Mission has provided unprecedented, nearly continuous photometric data of $\\sim$200,000 objects in the $\\sim$105 deg$^{2}$ field of view from the beginning of science operations in May of 2009 until the loss of the second reaction wheel in May of 2013. The Kepler Eclipsing Binary Catalog contains information including but not limited to ephemerides, stellar parameters and analytical approximation fits for every known eclipsing binary system in the Kepler Field of View. Using Target Pixel level data collected from Kepler in conjunction with the Kepler Eclipsing Binary Catalog, we identify false positives among eclipsing binaries, i.e. targets that are not eclipsing binaries themselves, but are instead contaminated by eclipsing binary sources nearby on the sky and show eclipsing binary signatures in their light curves. We present methods for identifying these false positives and for extracting new light curves for the true source of the observed binary signal. For each source, we extract three separa...

  5. Enhanced light extraction efficiency of chip-on board light-emitting diodes through micro-lens array fabricated by ion wind

    Science.gov (United States)

    Chu, Jingcao; Lei, Xiang; Wu, Jiading; Peng, Yang; Liu, Sheng; Yang, Qian; Zheng, Huai

    2017-03-01

    Low light extraction efficiency (LEE) is a key challenge of chip-on board (COB) packaging light-emitting diodes (LEDs). In this paper, a facile preparation of micro-lens array was proposed based on the ion wind patterning. The geometries and sizes of the micro-lens arrays were controlled through adjusting the voltage parameter of the ion wind generation. Consequently, the micro-lens array with the diameter of 180 μm and the gap distance of 15 μm has been fabricated. Benefitting from this micro-lens array, the LEE of COB packaging LEDs was enhanced by 9%. This facile fabrication of micro-lens array would be a promising method to improve the LEE of COB packaging LEDs.

  6. Evaluation of light extraction efficiency for the light-emitting diodes based on the transfer matrix formalism and ray-tracing method

    Science.gov (United States)

    Pingbo, An; Li, Wang; Hongxi, Lu; Zhiguo, Yu; Lei, Liu; Xin, Xi; Lixia, Zhao; Junxi, Wang; Jinmin, Li

    2016-06-01

    The internal quantum efficiency (IQE) of the light-emitting diodes can be calculated by the ratio of the external quantum efficiency (EQE) and the light extraction efficiency (LEE). The EQE can be measured experimentally, but the LEE is difficult to calculate due to the complicated LED structures. In this work, a model was established to calculate the LEE by combining the transfer matrix formalism and an in-plane ray tracing method. With the calculated LEE, the IQE was determined and made a good agreement with that obtained by the ABC model and temperature-dependent photoluminescence method. The proposed method makes the determination of the IQE more practical and conventional. Project supported by the National Natural Science Foundation of China (Nos.11574306, 61334009), the China International Science and Technology Cooperation Program (No. 2014DFG62280), and the National High Technology Program of China (No. 2015AA03A101).

  7. Metal-assisted electroless fabrication of nanoporous p-GaN for increasing the light extraction efficiency of light emitting diodes

    Directory of Open Access Journals (Sweden)

    Ruijun Wang

    2012-03-01

    Full Text Available We report metal-assisted electroless fabrication of nanoporous p-GaN to improve the light extraction efficiency of GaN-based light emitting diodes (LEDs. Although it has long been believed that p-GaN cannot be etched at room temperature, in this study we find that Ag nanocrystals (NCs on the p-GaN surface enable effective etching of p-GaN in a mixture of HF and K2S2O8 under ultraviolet (UV irradiation. It is further shown that the roughened GaN/air interface enables strong scattering of photons emitted from the multiple quantum wells (MQWs. The light output power measurements indicate that the nanoporous LEDs obtained after 10 min etching show a 32.7% enhancement in light-output relative to the conventional LEDs at an injection current of 20 mA without significant increase of the operating voltage. In contrast, the samples etched for 20 min show performance degradation when compared with those etched for 10 min, this is attributed to the current crowding effect and increased surface recombination rate.

  8. A Facile and Low-Cost Method to Enhance the Internal Quantum Yield and External Light-Extraction Efficiency for Flexible Light-Emitting Carbon-Dot Films

    Science.gov (United States)

    Jiang, Z. C.; Lin, T. N.; Lin, H. T.; Talite, M. J.; Tzeng, T. T.; Hsu, C. L.; Chiu, K. P.; Lin, C. A. J.; Shen, J. L.; Yuan, C. T.

    2016-01-01

    Solution-processed, non-toxic carbon dots (CDs) have attracted much attention due to their unique photoluminescence (PL) properties. They are promising emissive layers for flexible light-emitting devices. To this end, the CDs in pristine aqueous solutions need to be transferred to form solid-state thin films without sacrificing their original PL characteristics. Unfortunately, solid-state PL quenching induced by extra non-radiative (NR) energy transfer among CDs would significantly hinder their practical applications in optoelectronics. Here, a facile, low-cost and effective method has been utilized to fabricate high-performance CD/polymer light-emitting flexible films with submicron-structured patterns. The patterned polymers can serve as a solid matrix to disperse and passivate CDs, thus achieving high internal quantum yields of 61%. In addition, they can act as an out-coupler to mitigate the waveguide-mode losses, approximately doubling the external light-extraction efficiency. Such CD/polymer composites also exhibit good photo-stability, and thus can be used as eco-friendly, low-cost phosphors for solid-state lighting.

  9. Nanostructure surface patterning of GaN thin films and application to AlGaN/AlN multiple quantum wells: A way towards light extraction efficiency enhancement of III-nitride based light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wei, E-mail: wguo2@ncsu.edu; Kirste, Ronny; Bryan, Zachary; Bryan, Isaac; Collazo, Ramón; Sitar, Zlatko [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States); Gerhold, Michael [Engineering Science Directorate, Army Research Office, Research Triangle Park, North Carolina 27703 (United States)

    2015-03-21

    Enhanced light extraction efficiency was demonstrated on nanostructure patterned GaN and AlGaN/AlN Multiple-Quantum-Well (MQW) structures using mass production techniques including natural lithography and interference lithography with feature size as small as 100 nm. Periodic nanostructures showed higher light extraction efficiency and modified emission profile compared to non-periodic structures based on integral reflection and angular-resolved transmission measurement. Light extraction mechanism of macroscopic and microscopic nanopatterning is discussed, and the advantage of using periodic nanostructure patterning is provided. An enhanced photoluminescence emission intensity was observed on nanostructure patterned AlGaN/AlN MQW compared to as-grown structure, demonstrating a large-scale and mass-producible pathway to higher light extraction efficiency in deep-ultra-violet light-emitting diodes.

  10. Nanostructure surface patterning of GaN thin films and application to AlGaN/AlN multiple quantum wells: A way towards light extraction efficiency enhancement of III-nitride based light emitting diodes

    Science.gov (United States)

    Guo, Wei; Kirste, Ronny; Bryan, Zachary; Bryan, Isaac; Gerhold, Michael; Collazo, Ramón; Sitar, Zlatko

    2015-03-01

    Enhanced light extraction efficiency was demonstrated on nanostructure patterned GaN and AlGaN/AlN Multiple-Quantum-Well (MQW) structures using mass production techniques including natural lithography and interference lithography with feature size as small as 100 nm. Periodic nanostructures showed higher light extraction efficiency and modified emission profile compared to non-periodic structures based on integral reflection and angular-resolved transmission measurement. Light extraction mechanism of macroscopic and microscopic nanopatterning is discussed, and the advantage of using periodic nanostructure patterning is provided. An enhanced photoluminescence emission intensity was observed on nanostructure patterned AlGaN/AlN MQW compared to as-grown structure, demonstrating a large-scale and mass-producible pathway to higher light extraction efficiency in deep-ultra-violet light-emitting diodes.

  11. Fluorescent light mediated a green synthesis of silver nanoparticles using the protein extract of weaver ant larvae.

    Science.gov (United States)

    Khamhaengpol, Arunrat; Siri, Sineenat

    2016-10-01

    Alternative to crude plant extracts, a crude protein extract derived from animal cells is one of the potential sources of biomolecules for mediating a reduction of silver ions and a formation of silver nanoparticles (AgNPs) under a mild condition, which very few works have been reported. This work demonstrated a use of the protein extract of weaver ant larvae as a bio-facilitator for a simple, green synthesis of AgNPs under fluorescent light at room temperature. The protein extract of weaver ant larvae exhibited the reducing and antioxidant activities, which assisted a formation of AgNPs in the reaction containing only silver nitrate under light exposure. Transmission electron microscopy images revealed the dispersed, spherical AgNPs with an average size of 7.87±2.54nm. The maximum surface plasmon resonance (SPR) band of the synthesized AgNPs was at 435nm. The energy-dispersive X-ray analysis revealed that silver was a major element of the particles. The identity of AgNPs was confirmed by X-ray diffraction pattern, selected area electron diffraction and high resolution transmission electron microscopy analyses, which demonstrated the planes of face centered cubic silver. The synthesized AgNPs showed antibacterial activity against both Escherichia coli and Staphylococcus aureus with the minimum bactericidal concentration (MBC) values equally at 250μg/ml, suggesting their potential application as an effective antibacterial agent. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Photophysical processes and light extraction in organic light emitting devices; Photophysikalische Prozesse und Lichtextraktion in organischen Leuchtdioden

    Energy Technology Data Exchange (ETDEWEB)

    Reinke, Nils Andre

    2008-11-10

    Alq{sub 3} is the most commonly used material for electron transport and as an emission layer in organic LEDs. However many of its photophysical properties are still unknown. The phosphorescence - known as a low temperature effect - was measured at room temperature for the first time. A new experimental method is presented to identify and characterize a new molecular conversion process into an unknown dark state. This conversion process represents an additional fundamental energy loss channel which is especially important for the development of organic lasers. A physically intuitive model was developed, which allows the calculation of light emission from OLEDs. In addition, a new method for the quantification of optical losses in OLEDs based on an dipole approach has been implemented and verified experimentally. The use of OLEDs was demonstrated for the first time in a chemical sensor, which is based on the detection of the surface plasmon resonance. (orig.)

  13. Embeded photonic crystal at the interface of p-GaN and Ag reflector to improve light extraction of GaN-based flip-chip light-emitting diode

    Energy Technology Data Exchange (ETDEWEB)

    Zhen, Aigong; Ma, Ping, E-mail: maping@semi.ac.cn; Zhang, Yonghui; Guo, Enqing; Tian, Yingdong; Liu, Boting; Guo, Shikuan; Shan, Liang; Wang, Junxi; Li, Jinmin [Semiconductor Lighting R and D Center, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China)

    2014-12-22

    In this experiment, a flip-chip light-emitting diode with photonic crystal was fabricated at the interface of p-GaN and Ag reflector via nanospheres lithography technique. In this structure, photonic crystal could couple with the guide-light efficiently by reason of the little distance between photonic crystal and active region. The light output power of light emitting diode with embedded photonic crystal was 1.42 times larger than that of planar flip-chip light-emitting diode. Moreover, the embedded photonic crystal structure makes the far-field divergence angle decreased by 18° without spectra shift. The three-dimensional finite difference time domain simulation results show that photonic crystal could improve the light extraction, and enhance the light absorption caused by Ag reflector simultaneously, because of the roughed surface. The depth of photonic crystal is the key parameter affecting the light extraction and absorption. Light extraction efficiency increases with the depth photonic crystal structure rapidly, and reaches the maximum at the depth 80 nm, beyond which light extraction decrease drastically.

  14. Light

    CERN Document Server

    Robertson, William C

    2003-01-01

    Why is left right and right left in the mirror? Baffled by the basics of reflection and refraction? Wondering just how the eye works? If you have trouble teaching concepts about light that you don t fully grasp yourself, get help from a book that s both scientifically accurate and entertaining with Light. By combining clear explanations, clever drawings, and activities that use easy-to-find materials, this book covers what science teachers and parents need to know to teach about light with confidence. It uses ray, wave, and particle models of light to explain the basics of reflection and refraction, optical instruments, polarization of light, and interference and diffraction. There s also an entire chapter on how the eye works. Each chapter ends with a Summary and Applications section that reinforces concepts with everyday examples. Whether you need a deeper understanding of how light bends or a good explanation of why the sky is blue, you ll find Light more illuminating and accessible than a college textbook...

  15. Design of an LED chip structure with an integrated two-dimensional photonic crystal to enhance the light-extraction efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Won-Sik; Park, Si-Hyun [Yeungnam University, Gyeongsan (Korea, Republic of)

    2014-05-15

    We numerically simulated the light-extraction efficiency of light-emitting diodes (LEDs) with an integrated two-dimensional photonic crystal (PC) structure on the top surface in order to enhance light extraction. We considered InGaN-based LED chips with a typical emission wavelength of λ{sub o} = 460 nm and an emission wavelength inside the LED chip of λ = λ{sub 0}/n{sub GaN} , where n{sub GaN} is the refractive index of GaN. We used positive (relief) and negative (intaglio) patterns for the PC structures with square arrangements. The pattern period (Λ), width (d), and height (h) of the PC structure were varied systematically in the PC-LEDs; then the light-extraction efficiency of each PC-LED was simulated numerically using a three-dimensional finite-difference time-domain method to optimize the PC structure in terms of light extraction. The PC LED with a square pillar pattern with Λ ∼ 1.4λ, d ∼ 0.75Λ, and h ∼ 0.75Λ had the maximum light-extraction efficiency for positive patterns while the cylindrical hole pattern with Λ ∼ 1.2λ, d ∼ 0.5Λ, and h ∼ 0.5Λ had the maximum light-extraction efficiency for negative patterns.

  16. EXTRACT

    DEFF Research Database (Denmark)

    Pafilis, Evangelos; Buttigieg, Pier Luigi; Ferrell, Barbra

    2016-01-01

    The microbial and molecular ecology research communities have made substantial progress on developing standards for annotating samples with environment metadata. However, sample manual annotation is a highly labor intensive process and requires familiarity with the terminologies used. We have the...... and text-mining-assisted curation revealed that EXTRACT speeds up annotation by 15-25% and helps curators to detect terms that would otherwise have been missed.Database URL: https://extract.hcmr.gr/....

  17. The Effect of Citrullus colocynthis Pulp Extract on the Liver of Diabetic Rats a Light and Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    Mohammad Khalil

    2010-01-01

    Full Text Available Problem statement: The goal of the current investigation was to clarify the effects of Citrullus colocynthis pulp extract on the structure of the liver of diabetic rats at both light and scanning electron microscopic levels. Approach: Forty-eight adult male albino rats were equally allocated into four groups: Group1: control, Group 2: Citrullus colocynthis-treated, Group 3: diabetic rats and Group4: diabetic rats treated with Citrullus colocynthis. All treatments were administered via an intragastric tube. Diabetes was induced in the rats of groups 3 and 4 by an intraperitoneal injection with alloxan. Results: The liver of Citrullus colocynthis-treated rats revealed minor histological changes versus the control animals. In group 3 animals, diabetes caused degenerative alterations in the form of disorganization of the hepatic cords, cytoplasmic vacuolization and pyknosis of the nuclei of hepatocytes and inflammatory cell infiltration. Scanning electron microscope examination of these livers revealed numerous lipid droplets within hepatocytes, damaged blood sinusoids and hemorrhage of erythrocytes between hepatocytes and inside Disse’s spaces. On the other hand, the normal histological and scanning ultrastructural features were nearly resumed in the liver of diabetic rats treated with Citrullus colocynthis pulp extract. Conclusion: The present study proved a lessening effect of Citrullus colocynthis pulp extract on the liver of diabetic rats. In light of these advantageous influences, it is advisable to widen the scale of its use in a trial to alleviate the diabetic hepatic adverse effects.

  18. Kepler Eclipsing Binary Stars. VIII. Identification of False Positive Eclipsing Binaries and Re-extraction of New Light Curves

    Science.gov (United States)

    Abdul-Masih, Michael; Prša, Andrej; Conroy, Kyle; Bloemen, Steven; Boyajian, Tabetha; Doyle, Laurance R.; Johnston, Cole; Kostov, Veselin; Latham, David W.; Matijevič, Gal; Shporer, Avi; Southworth, John

    2016-04-01

    The Kepler mission has provided unprecedented, nearly continuous photometric data of ∼200,000 objects in the ∼105 deg2 field of view (FOV) from the beginning of science operations in May of 2009 until the loss of the second reaction wheel in May of 2013. The Kepler Eclipsing Binary Catalog contains information including but not limited to ephemerides, stellar parameters, and analytical approximation fits for every known eclipsing binary system in the Kepler FOV. Using target pixel level data collected from Kepler in conjunction with the Kepler Eclipsing Binary Catalog, we identify false positives among eclipsing binaries, i.e., targets that are not eclipsing binaries themselves, but are instead contaminated by eclipsing binary sources nearby on the sky and show eclipsing binary signatures in their light curves. We present methods for identifying these false positives and for extracting new light curves for the true source of the observed binary signal. For each source, we extract three separate light curves for each quarter of available data by optimizing the signal-to-noise ratio, the relative percent eclipse depth, and the flux eclipse depth. We present 289 new eclipsing binaries in the Kepler FOV that were not targets for observation, and these have been added to the catalog. An online version of this catalog with downloadable content and visualization tools is maintained at http://keplerEBs.villanova.edu.

  19. Investigation of high extraction efficiency flip-chip GaN-based light-emitting diodes

    Institute of Scientific and Technical Information of China (English)

    DA XiaoLi; SHEN GuangDi; XU Chen; ZOU DeShu; ZHU YanXu; ZHANG JianMing

    2009-01-01

    In order to obtain higher light output power, the flip-chip structure Is used. We studied the ratio of the light of GaN sides before and after fabricating metal reflector on p-GaN. The SiO2/SiNx dielectric film reflectors were deposited through plasma enhance chemical vapor deposition following the fabrication of metal reflector, and then the dielectric film reflectors on the electrodes were etched in order to expose the electrodes to the air. It is found that comparing with the flip-chip GaN-LED without dielectric film reflectors, light output power can be increased by as high as 10.2% after the deposition of 2 pairs of SiO2/SiNx dielectric film reflectors on GaN-LEDs, which cover the sidewalls and the areas without the metal reflector. This result indicates that the high reflector formed by multi-layer dielectric films is useful to enhance the light output power of GaN-based LED, which reflects light from step sidewalls and p-GaN without metal reflector to internal, and then light emits from the surface.

  20. Studies on pigments of the myxomycete Physarum nudum. I. Absorption spectra of the crude extracts of pigments from plasmodia cultured in continuous light and in darkness

    Directory of Open Access Journals (Sweden)

    L. Rakoczy

    2015-01-01

    Full Text Available 1. Method for extraction and crude separation of the plasmodial pigments of the myxomycete Physarum nudum cultured in light and in darkness were elaborated. 2.\tBy the use of various solvents in the procedure of extraction three pigment fractions were obtained from plasmodia cultured in the dark and four fractions from those grown under continuous light. 3. The absorption spectra of the particular fractions within the UV and visible range were determined.

  1. Fabrication of dodecagonal pyramid on nitrogen face GaN and its effect on the light extraction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Wet etching has been widely used in defect evaluation for Ga-face GaN and surface roughness for N-face GaN dodecagonal pyramids has been fabricated on laser-lift-off N-face GaN by hot phosphor acid etching.The dodecagonal pyramid shows twelve facets including six{20-2-3}and six{22-4-5}planes.From cross-sectional TEM image,it is shown that the pyramid corresponds to the top of the edge dislocation.Compared with hexagonal pyramid-surface light emitting diodes(LEDs)etched by commonly used photoelectrochemical(PEC)process in KOH aqueous,the dodecagonal pyramid-surface LEDs show improved light extraction efficiency because of more facets,which effectively reduces the total internal reflection.

  2. Light extraction efficiency of GaN-based LED with pyramid texture by using ray path analysis.

    Science.gov (United States)

    Pan, Jui-Wen; Wang, Chia-Shen

    2012-09-10

    We study three different gallium-nitride (GaN) based light emitting diode (LED) cases based on the different locations of the pyramid textures. In case 1, the pyramid texture is located on the sapphire top surface, in case 2, the pyramid texture is locate on the P-GaN top surface, while in case 3, the pyramid texture is located on both the sapphire and P-GaN top surfaces. We study the relationship between the light extraction efficiency (LEE) and angle of slant of the pyramid texture. The optimization of total LEE was highest for case 3 among the three cases. Moreover, the seven escape paths along which most of the escaped photon flux propagated were selected in a simulation of the LEDs. The seven escape paths were used to estimate the slant angle for the optimization of LEE and to precisely analyze the photon escape path.

  3. Magnetosomes extracted from Magnetospirillum magneticum strain AMB-1 showed enhanced peroxidase-like activity under visible-light irradiation.

    Science.gov (United States)

    Li, Kefeng; Chen, Chuanfang; Chen, Changyou; Wang, Yuzhan; Wei, Zhao; Pan, Weidong; Song, Tao

    2015-05-01

    Magnetosomes are intracellular structures produced by magnetotactic bacteria and are magnetic nanoparticles surrounded by a lipid bilayer membrane. Magnetosomes reportedly possess intrinsic enzyme mimetic activity similar to that found in horseradish peroxidase (HRP) and can scavenge reactive oxygen species depending on peroxidase activity. Our previous study has demonstrated the phototaxis characteristics of Magnetospirillum magneticum strain AMB-1 cells, but the mechanism is not well understood. Therefore, we studied the relationship between visible-light irradiation and peroxidase-like activity of magnetosomes extracted from M. magneticum strain AMB-1. We then compared this characteristic with that of HRP, iron ions, and naked magnetosomes using 3,3',5,5'-tetramethylbenzidine as a peroxidase substrate in the presence of H2O2. Results showed that HRP and iron ions had different activities from those of magnetosomes and naked magnetosomes when exposed to visible-light irradiation. Magnetosomes and naked magnetosomes had enhanced peroxidase-like activities under visible-light irradiation, but magnetosomes showed less affinity toward substrates than naked magnetosomes under visible-light irradiation. These results suggested that the peroxidase-like activity of magnetosomes may follow an ordered ternary mechanism rather than a ping-pong mechanism. This finding may provide new insight into the function of magnetosomes in the phototaxis in magnetotactic bacteria.

  4. Light extraction from 2D materials using liquid formed micro-lenses

    CERN Document Server

    Woodhead, Christopher S; Noori, Yasir J; Cao, Yameng; Bernardo-Gavito, Ramón; Tovee, Peter; Kozikov, Aleksey; Novoselov, Konstantin; Young, Robert J

    2016-01-01

    The recent discovery of semiconducting two-dimensional materials has led to the prediction of a revolution in the field of optoelectronics, driven by the introduction of a series of new components that are just a few atoms thick. Key remaining challenges for producing practical devices from these materials lie in improving the coupling of light into and out of single atomic layers, and in making these layers robust to the influence of their surrounding environment. We present a solution to tackle both of these problems simultaneously, by deterministically placing a micro-lens directly onto the surface of these materials. These lenses are dynamically tuned to increase the coupling of light, whilst controlling chromatic aberration, before being set in place with UV light. We show that this approach enhances photoluminescence of tungsten diselenide (WSe2) monolayers by up to 300%, and nearly doubles the imaging resolution of the system. Furthermore, this solution fully encapsulates the monolayer, preventing it f...

  5. AstroImageJ: Image Processing and Photometric Extraction for Ultra-Precise Astronomical Light Curves

    CERN Document Server

    Collins, Karen A; Stassun, Keivan G

    2016-01-01

    ImageJ is a graphical user interface (GUI) driven, public domain, Java-based, software package for general image processing traditionally used mainly in life sciences fields. The image processing capabilities of ImageJ are useful and extendable to other scientific fields. Here we present AstroImageJ (AIJ), which provides an astronomy specific image display environment and tools for astronomy specific image calibration and data reduction. Although AIJ maintains the general purpose image processing capabilities of ImageJ, AIJ is streamlined for time-series differential photometry, light curve detrending and fitting, and light curve plotting, especially for applications requiring ultra-precise light curves (e.g., exoplanet transits). AIJ reads and writes standard FITS files, as well as other common image formats, provides FITS header viewing and editing, and is World Coordinate System (WCS) aware, including an automated interface to the astrometry.net web portal for plate solving images. Although AIJ provides re...

  6. Light

    CERN Document Server

    Ditchburn, R W

    2011-01-01

    This classic study, available for the first time in paperback, clearly demonstrates how quantum theory is a natural development of wave theory, and how these two theories, once thought to be irreconcilable, together comprise a single valid theory of light. Aimed at students with an intermediate-level knowledge of physics, the book first offers a historical introduction to the subject, then covers topics such as wave theory, interference, diffraction, Huygens' Principle, Fermat's Principle, and the accuracy of optical measurements. Additional topics include the velocity of light, relativistic o

  7. In vitro gastric and intestinal digestions of pulsed light-treated shrimp extracts

    Science.gov (United States)

    Pulsed ultraviolet light (PUV), a novel technology most commonly used for microbial inactivation, has recently been employed to effectively mitigate food allergens in peanuts, soybean, shrimp, and almond. Putative mechanisms for the efficacy of PUV in reducing allergen reactivity, include photother...

  8. Efficient optimization method for the light extraction from periodically modulated LEDs using reciprocity

    NARCIS (Netherlands)

    Janssen, O.T.A.; Wachters, A.J.H.; Urbach, H.P.

    2010-01-01

    The incoherent emission of periodically structured Light Emitting Diodes (LEDs) can be computed at relatively low computational cost by applying the reciprocity method. We show that by another application of the reciprocity principle, the structure of the LED can be optimized to obtain a high emissi

  9. An optimal light-extracting overlayer, inspired by the lantern of a Photuris firefly, to improve the external efficiency of existing light-emitting diodes

    CERN Document Server

    Bay, Annick; Sarrazin, Michael; Belarouci, Ali; Aimez, Vincent; Francis, Laurent A; Vigneron, Jean Pol

    2012-01-01

    Actual light emission diodes (LED) have most often good internal efficiencies but poor external efficiencies due to total internal reflection at the air interface. In this paper the design, fabrication and characterization of a bioinspired overlayer deposited on a GaN LED is investigated. The purpose of this overlayer is to improve light extraction into air, after the photons have been generated in the diode's high refractive-index active material. The layer design is inspired by the microstructure found in the firefly Photuris sp., described by Bay et al. : a surface with an asymmetrical triangular profile (a "factory-roof" shape), developed on the scale of a few micrometers, thus somewhat larger than usually suggested in the related literature. The profile of the overlayer corrugated surface of the coating film was copied from the natural model. Yet, the actual dimensions and material composition have been optimized to take into account the high refractive index of the GaN diode stack. The optimization proc...

  10. Analysis of the light-extraction efficiency of SiC substrate-based flip-chip vertical light-emitting diodes with embedded photonic crystals

    Science.gov (United States)

    Liu, Meng; Li, Kang; Kong, Fan-min; Zhao, Jia; Zhao, Shu-long; Meng, Hao-tian

    2016-11-01

    To improve the light-extraction efficiency (LEE) of flip-chip vertical light-emitting diodes (LEDs) grown on silicon carbide (SiC) substrate, embedded photonic crystals (PhCs) were alternatively introduced into the n-GaN layer of LEDs, since etching of the SiC substrate was very difficult. The finite-difference time-domain (FDTD) method was employed to investigate the combination effects of the micro-cavity and the embedded PhCs. The influences of the PhCs configurations on the LEE of LEDs were also examined to get an optimal structure. With the optimized parameters, about 20% enhancement of LEE was achieved comparing to planar SiC substrate-based flip-chip vertical LEDs. The LEE of conventional surface PhCs LEDs and double layer PhCs LEDs were also investigated for comparison. The results indicated that LEDs with carefully designed embedded PhCs could provide more LEE than surface PhCs LEDs. The structures proposed here offered scopes for the design of high-efficiency, high-power LEDs.

  11. Light extraction enhancement of 265 nm deep-ultraviolet light-emitting diodes with over 90 mW output power via an AlN hybrid nanostructure

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Shin-ichiro, E-mail: s-inoue@nict.go.jp [Advanced ICT Research Institute, National Institute of Information and Communications Technology (NICT), Kobe, Hyogo 651-2492 (Japan); Naoki, Tamari [Advanced ICT Research Institute, National Institute of Information and Communications Technology (NICT), Kobe, Hyogo 651-2492 (Japan); Tsukuba Research Laboratories, Tokuyama Corporation, Tsukuba, Ibaraki 300-4247 (Japan); Kinoshita, Toru; Obata, Toshiyuki; Yanagi, Hiroyuki [Tsukuba Research Laboratories, Tokuyama Corporation, Tsukuba, Ibaraki 300-4247 (Japan)

    2015-03-30

    Deep-ultraviolet (DUV) aluminum gallium nitride-based light-emitting diodes (LEDs) on transparent aluminum nitride (AlN) substrates with high light extraction efficiency and high power are proposed and demonstrated. The AlN bottom side surface configuration, which is composed of a hybrid structure of photonic crystals and subwavelength nanostructures, has been designed using finite-difference time-domain calculations to enhance light extraction. We have experimentally demonstrated an output power improvement of up to 196% as a result of the use of the embedded high-light-extraction hybrid nanophotonic structure. The DUV-LEDs produced have demonstrated output power as high as 90 mW in DC operation at a peak emission wavelength of 265 nm.

  12. Surface Light Extraction Mapping from Two-Dimensional Array of 12-Fold Photonic Quasicrystal on Current Injected GaN-Based LEDs

    Institute of Scientific and Technical Information of China (English)

    DAI Tao; ZHU Xing; ZHANG Bei; ZHANG Zhen-Sheng; LIU Dan; WANG Xiao; BAO Kui; KANG Xiang-Ning; XU Jun; Yu Da-Peng

    2007-01-01

    A two-dimensional array of dodecagonal photonic quasicrystal(12PQC)is fabricated on the surface of current injected GaN-based LEDs to out-couple guided modes.The spatially-resolved surface light extraction mapping of 12PQC is observed and compared with that of triangular lattice photonic crystal (3PC)by microscopic electrical luminescence and scanning near-field microscopy.The higher enhancement factor of 12PQC is obtained to be larger than that of 3PC.It is shown that 12PQC is more favourable and efficient for light extraction of guided lights.

  13. Increasing the light extraction and longevity of TMDC monolayers using liquid formed micro-lenses

    Science.gov (United States)

    Woodhead, C. S.; Roberts, J.; Noori, Y. J.; Cao, Y.; Bernardo-Gavito, R.; Tovee, P.; Kozikov, A.; Novoselov, K.; Young, R. J.

    2017-03-01

    The recent discovery of semiconducting two-dimensional materials is predicted to lead to the introduction of a series of revolutionary optoelectronic components that are just a few atoms thick. Key remaining challenges for producing practical devices from these materials lie in improving the coupling of light into and out of single atomic layers, and in making these layers robust to the influence of their surrounding environment. We present a solution to tackle both of these problems simultaneously, by deterministically placing an epoxy based micro-lens directly onto the materials’ surface. We show that this approach enhances the photoluminescence of tungsten diselenide (WSe2) monolayers by up to 300%, and nearly doubles the imaging resolution of the system. Furthermore, this solution fully encapsulates the monolayer, preventing it from physical damage and degradation in air. The optical solution we have developed could become a key enabling technology for the mass production of ultra-thin optical devices, such as quantum light emitting diodes.

  14. HEIDI: An Automated Process for the Identification and Extraction of Photometric Light Curves from Astronomical Images

    CERN Document Server

    Todd, M; Tanga, P; Coward, D M; Zadnik, M G

    2014-01-01

    The production of photometric light curves from astronomical images is a very time-consuming task. Larger data sets improve the resolution of the light curve, however, the time requirement scales with data volume. The data analysis is often made more difficult by factors such as a lack of suitable calibration sources and the need to correct for variations in observing conditions from one image to another. Often these variations are unpredictable and corrections are based on experience and intuition. The High Efficiency Image Detection & Identification (HEIDI) pipeline software rapidly processes sets of astronomical images. HEIDI automatically selects multiple sources for calibrating the images using an algorithm that provides a reliable means of correcting for variations between images in a time series. The algorithm takes into account that some sources may intrinsically vary on short time scales and excludes these from being used as calibration sources. HEIDI processes a set of images from an entire nigh...

  15. AstroImageJ: Image Processing and Photometric Extraction for Ultra-precise Astronomical Light Curves

    Science.gov (United States)

    Collins, Karen A.; Kielkopf, John F.; Stassun, Keivan G.; Hessman, Frederic V.

    2017-02-01

    ImageJ is a graphical user interface (GUI) driven, public domain, Java-based, software package for general image processing traditionally used mainly in life sciences fields. The image processing capabilities of ImageJ are useful and extendable to other scientific fields. Here we present AstroImageJ (AIJ), which provides an astronomy specific image display environment and tools for astronomy specific image calibration and data reduction. Although AIJ maintains the general purpose image processing capabilities of ImageJ, AIJ is streamlined for time-series differential photometry, light curve detrending and fitting, and light curve plotting, especially for applications requiring ultra-precise light curves (e.g., exoplanet transits). AIJ reads and writes standard Flexible Image Transport System (FITS) files, as well as other common image formats, provides FITS header viewing and editing, and is World Coordinate System aware, including an automated interface to the astrometry.net web portal for plate solving images. AIJ provides research grade image calibration and analysis tools with a GUI driven approach, and easily installed cross-platform compatibility. It enables new users, even at the level of undergraduate student, high school student, or amateur astronomer, to quickly start processing, modeling, and plotting astronomical image data with one tightly integrated software package.

  16. MQWs InGaN/GaN LED with embedded micro-mirror array in the epitaxial-lateral-overgrowth gallium nitride for light extraction enhancement.

    Science.gov (United States)

    Huang, Chen-Yang; Ku, Hao-Min; Liao, Chen-Zi; Chao, Shiuh

    2010-05-10

    Multi-quantum wells (MQWs) InGaN/GaN LEDs, 300 microm x 300 microm chip size, were fabricated with Ta(2)O(5) / SiO(2) dielectric multi-layer micro-mirror array (MMA) embedded in the epitaxiallateral- overgrowth (ELOG) gallium nitride (GaN) on the c-plane sapphire substrate. MQWs InGaN/GaN LEDs with ELOG embedded patterned SiO(2) array (P-SiO(2)) of the same dimension as the MMA were also fabricated for comparison. Dislocation density was reduced for the ELOG samples. 75.2% light extraction enhancement for P-SiO(2)-LED and 102.6% light extraction enhancement for MMA-LED were obtained over the standard LED. We showed that multiple-diffraction with high intensity from the MMA redirected the trap lights to escape from the LED causing the light extraction enhancement.

  17. SILAR-Based Application of Various Nanopillars on GaN-Based LED to Enhance Light-Extraction Efficiency

    Directory of Open Access Journals (Sweden)

    S. C. Shei

    2013-01-01

    Full Text Available We reported the various nanopillars on GaN-based LED to enhance light-extraction efficiency prepared by successive ionic layer adsorption and reaction method (SILAR. Indium tin oxide (ITO with thickness of 1 μm as transparent contact layer was grown to improve the electrical characteristics of the LEDs, including series resistance and operating voltage. SILAR-deposition ZnO nanoparticles on SiO2 were used as etching nanomasks. Multiple nanopillars were simultaneously formed on overall surfaces of ITO p- and n-GaN by ICP etching. The proposed GaN-based LEDs with nanopillars increase light output power by 7%–20.3% (at 20 mA over that of regular GaN-based LEDs. The difference in light output power can be attributed to differences in materials and shapes of nanopillars, resulting in a reduction in Fresnel reflection by the roughened surface of GaN-based LEDs.

  18. Enhanced light extraction in ITO-free OLEDs using double-sided printed electrodes

    Science.gov (United States)

    Reboud, Vincent; Khokhar, Ali Z.; Sepúlveda, Borja; Dudek, Damian; Kehoe, Tim; Cuffe, John; Kehagias, Nikolaos; Lira-Cantu, Mónica; Gadegaard, Nikolaj; Grasso, Valentina; Lambertini, Vito; Sotomayor Torres, Clivia M.

    2012-05-01

    We show how nanoimprint lithographic techniques are particularly suited for the realization of OLED device structures. We tested them to realize nanopatterned metallic electrodes containing photonic crystals to couple the light out and plasmonic crystals showing extraordinary transmission. At similar current densities, a two-fold electroluminescence is achieved with devices having double-sided structured metallic electrodes as compared to a control OLED with an ITO anode. The use of combined nanoimprint lithography processes has the potential to expand the performance range of various organic optoelectronic devices.

  19. Herbal tea extract combined with light-induced significant in vitro cytotoxicity of human bladder cancer cells

    Science.gov (United States)

    Nseyo, Unyime; Kim, Albert; Stavropoulos, Nicholas E.; Skalkos, Dimitris; Nseyo, U. U.; Chung, Theodore D.

    2005-04-01

    The anti-inflammatory, anti-microbial, antiviral, and antidepressant activities of the Greek herb, Hypericum Perforatum L, HP L, have been attributed to the total extract or single constituents. We investigated the use of the extract,specifically of the polar methanolic fraction (PMF) of Epirus"HPL in photodynamic therapy (PDT) alone and in combination with recombinant Interferon-a2b (IFN) and gemcitabine (GCB) in the treatment of human bladder cancer cells. The PMF was extracted from the dry herb with methanol, followed by liquid-liquid extraction with petroleum ether. T-24 bladder cancer cells were plated (105 cells/well) and placed in the incubator (370 C, 5%CO) for 24 hours prior to addition of drugs. PMF 60ug/ml was added and incubation continued. After 24 hours, the cells were subjected to laser light (630nm) treatment with 0, 1, 4 and 8 Joules. After reincubation for 24 hours, IFN, (50,000 IU) or GCB, (2ug/ml) was added to the PDT-treated cells. After this incubation cell survival was assessed by the MTT assay. PMF-PDT alone-induced percent cell kill of 0%, 8%, 44% and 80% versus 31%, 64 and 86 % for PMF-PDT and IFN, versus 63%, 80% and 88% for MPF-PDT plus GCB at 1, 2, 4 and 8 Joules respectively. IFN and GCB induced 20% and 53% cell kill respectively. Our data suggest that MPF may be an effective agent for in vitro photodynamic therapy. PMF-PDT combined with Intron A, or gemcitabine achieved improved kill of cultured bladder cancer cells. Confirmation of these results in preclinical studies may lead to clinical trials.

  20. Stability of individual carotenoids, retinol and tocopherols in human plasma during exposure to light and after extraction.

    Science.gov (United States)

    Su, Q; Rowley, K G; O'Dea, K

    1999-06-11

    We have modified gradient HPLC procedures for simultaneous quantification of retinol, gamma-tocopherol, alpha-tocopherol, lutein/zeaxanthin, beta-cryptoxanthin, trans-lycopene, cis-lycopene, alpha-carotene and beta-carotene in 200-microl aliquots of human plasma. The photosensitivity of these analytes in plasma exposed to fluorescent lighting for up to 72 h was investigated and most were stable under these conditions. The stability of these analytes held in darkness at -20 degrees C, 4 degrees C or room temperature for up to 48 h after extraction from plasma was also investigated. Variability in measurement of most analytes was greater at room temperature than at 4 degrees C or -20 degrees C. There were statistically significant variations in the measured concentrations of some analytes in samples kept cold. However, the magnitude of these variations was small and of little biological significance, particularly over the first 24 h.

  1. Enhanced light extraction of GaN-based light-emitting diodes with periodic textured SiO2 on Al-doped ZnO transparent conductive layer

    Science.gov (United States)

    Yu, Zhao; Bingfeng, Fan; Yiting, Chen; Yi, Zhuo; Zhoujun, Pang; Zhen, Liu; Gang, Wang

    2016-07-01

    We report an effective enhancement in light extraction of GaN-based light-emitting diodes (LEDs) with an Al-doped ZnO (AZO) transparent conductive layer by incorporating a top regular textured SiO2 layer. The 2 inch transparent through-pore anodic aluminum oxide (AAO) membrane was fabricated and used as the etching mask. The periodic pore with a pitch of about 410 nm was successfully transferred to the surface of the SiO2 layer without any etching damages to the AZO layer and the electrodes. The light output power was enhanced by 19% at 20 mA and 56% at 100 mA compared to that of the planar LEDs without a patterned surface. This approach offers a technique to fabricate a low-cost and large-area regular pattern on the LED chip for achieving enhanced light extraction without an obvious increase of the forward voltage. ).

  2. Exploring light extraction efficiency of InGaN LED by creating structured voids in substrate with a femtosecond laser

    Science.gov (United States)

    Wu, Shih-jeh; Tseng, Chun-Lung; Lu, Tsung-Sheng; Chen, Ying-Chieh; Tseng, Pei-Hsiang

    2017-02-01

    The applications of laser in processing of light-emitting diodes (LEDs) have become popular and inevitable. In this paper, we reported a complete fabrication process of InGaN LED involving a small modification of substrate by ultrafast laser. We created structured voids within the pattern sapphire substrate (PSS) with distributed Bragg reflector (DBR) on the backside by a tightly focused femtosecond laser. One or two passes of voids were aligned in rectangular grid shape and a study of different grid spacing was conducted. The wafers were stealth-diced by the same laser and mechanically cleaved after the on-wafer light output powers (LOP) are measured at 120 mA nominal current. The splitted chips are then undergone complete packaging process and LOP is measured again along with the electrical and irradiation properties. A raise of 1.35% of average on-wafer LOP is achieved at the optimal condition: 0.2 W total laser power for two passes of voids (grid spacing 40 μm) at focal depths set at 32 μm and 64 μm respectively from the backside. Also, the illumination efficiency is further improved by 4.59% after epoxy molding compound (EMC) packaging. The voids serve successfully as scattering or diffractive sources to reverse the stray photons in useful directions. Apart from the enhancement from both PSS and DBR there is still room for light extraction efficiency (LEE) improvement. The L-I-V relationship and diffusion angle are also presented.

  3. IMAGING SPECTROSCOPY AND LIGHT DETECTION AND RANGING DATA FUSION FOR URBAN FEATURES EXTRACTION

    Directory of Open Access Journals (Sweden)

    Mohammed Idrees

    2013-01-01

    Full Text Available This study presents our findings on the fusion of Imaging Spectroscopy (IS and LiDAR data for urban feature extraction. We carried out necessary preprocessing of the hyperspectral image. Minimum Noise Fraction (MNF transforms was used for ordering hyperspectral bands according to their noise. Thereafter, we employed Optimum Index Factor (OIF to statistically select the three most appropriate bands combination from MNF result. The composite image was classified using unsupervised classification (k-mean algorithm and the accuracy of the classification assessed. Digital Surface Model (DSM and LiDAR intensity were generated from the LiDAR point cloud. The LiDAR intensity was filtered to remove the noise. Hue Saturation Intensity (HSI fusion algorithm was used to fuse the imaging spectroscopy and DSM as well as imaging spectroscopy and filtered intensity. The fusion of imaging spectroscopy and DSM was found to be better than that of imaging spectroscopy and LiDAR intensity quantitatively. The three datasets (imaging spectrocopy, DSM and Lidar intensity fused data were classified into four classes: building, pavement, trees and grass using unsupervised classification and the accuracy of the classification assessed. The result of the study shows that fusion of imaging spectroscopy and LiDAR data improved the visual identification of surface features. Also, the classification accuracy improved from an overall accuracy of 84.6% for the imaging spectroscopy data to 90.2% for the DSM fused data. Similarly, the Kappa Coefficient increased from 0.71 to 0.82. on the other hand, classification of the fused LiDAR intensity and imaging spectroscopy data perform poorly quantitatively with overall accuracy of 27.8% and kappa coefficient of 0.0988.

  4. The relationship between visible light emission and species fraction of the hydrogen ion beams extracted from 2.45 GHz microwave discharge

    CERN Document Server

    Cortázar, O D; Tarvainen, O; Kalvas, T; Koivisto, H

    2015-01-01

    The relationship between Balmer-α and Fulcher-band emissions with extracted H +, H+2 , and H+3 ions is demonstrated for a 2.45 GHz microwave discharge. Ion mass spectra and optical measurements of Balmer-α and Fulcher-band emissions have been obtained with a Wien Filter having an optical view-port on the plasma chamber axis. The beam of approximately 1 mA is analyzed for different plasma conditions simultaneously with the measurement of light emissions both with temporal resolution. The use of visible light emissions as a valuable diagnostic tool for monitoring the species fraction of the extracted beams is proposed.

  5. Antireflective sub-wavelength structures for improvement of the extraction efficiency and color rendering index of monolithic white light-emitting diode

    DEFF Research Database (Denmark)

    Ou, Yiyu; Corell, Dennis Dan; Dam-Hansen, Carsten

    2011-01-01

    simulation results show that a moth-eye structure enhances the light extraction efficiency over the entire visible light range with an extraction efficiency enhancement of up to 26 %. Also for the first time to our best knowledge, the influence of sub-wavelength structures on both the color rendering index......We have theoretically investigated the influence of antireflective sub-wavelength structures on a monolithic white light-emitting diode (LED). The simulation is based on the rigorous coupled wave analysis (RCWA) algorithm, and both cylinder and moth-eye structures have been studied in the work. Our...... (CRI) and the correlated color temperature (CCT) of the monolithic white LED have been demonstrated. The CRI of the monolithic white LED could be improved from 92.68 to around 94 by applying a cylinder structure, and the CCT could be modified in a very large range with appropriate design...

  6. Size-resolved measurements of brown carbon in water and methanol extracts and estimates of their contribution to ambient fine-particle light absorption

    Science.gov (United States)

    Liu, J.; Bergin, M.; Guo, H.; King, L.; Kotra, N.; Edgerton, E.; Weber, R. J.

    2013-12-01

    Light absorbing organic carbon, often called brown carbon, has the potential to significantly contribute to the visible light-absorption budget, particularly at shorter wavelengths. Currently, the relative contributions of particulate brown carbon to light absorption, as well as the sources of brown carbon, are poorly understood. With this in mind size-resolved direct measurements of brown carbon were made at both urban (Atlanta), and rural (Yorkville) sites in Georgia. Measurements in Atlanta were made at both a representative urban site and a road-side site adjacent to a main highway. Fine particle absorption was measured with a multi-angle absorption photometer (MAAP) and seven-wavelength Aethalometer, and brown carbon absorption was estimated based on Mie calculations using direct size-resolved measurements of chromophores in solvents. Size-resolved samples were collected using a cascade impactor and analyzed for water-soluble organic carbon (WSOC), organic and elemental carbon (OC and EC), and solution light-absorption spectra of water and methanol extracts. Methanol extracts were more light-absorbing than water extracts for all size ranges and wavelengths. Absorption refractive indices of the organic extracts were calculated from solution measurements for a range of wavelengths and used with Mie theory to predict the light absorption by fine particles comprised of these components, under the assumption that brown carbon and other aerosol components were externally mixed. For all three sites, chromophores were predominately in the accumulation mode with an aerodynamic mean diameter of 0.5 μm, an optically effective size range resulting in predicted particle light absorption being a factor of 2 higher than bulk solution absorption. Mie-predicted brown carbon absorption at 350 nm contributed a significant fraction (20 to 40%) relative to total light absorption, with the highest contributions at the rural site where organic to elemental carbon ratios were

  7. Size-resolved measurements of brown carbon and estimates of their contribution to ambient fine particle light absorption based on water and methanol extracts

    Science.gov (United States)

    Liu, J.; Bergin, M.; Guo, H.; King, L.; Kotra, N.; Edgerton, E.; Weber, R. J.

    2013-07-01

    Light absorbing organic carbon, often termed brown carbon, has the potential to significantly contribute to the visible light absorption budget, particularly at shorter wavelengths. Currently, the relative contributions of particulate brown carbon to light absorption, as well as the sources of brown carbon are poorly understood. With this in mind field measurements were made at both urban (Atlanta), and rural (Yorkville) sites in Georgia. Measurements in Atlanta were made at both a central site and a road side site adjacent to a main highway near the city center. Fine particle brown carbon optical absorption is estimated based on Mie calculations using direct size resolved measurements of chromophores in filter extracts. Size-resolved atmospheric aerosol samples were collected using a cascade impactor and analyzed for water-soluble organic carbon (WSOC), organic and elemental carbon (OC and EC), and solution light absorption spectra of water and methanol extracts. Methanol extracts were more light-absorbing than water extracts for all size ranges and wavelengths. Absorption refractive indices of the organic extracts were calculated from solution measurements for a range of wavelengths and used with Mie theory to predict the light absorption by fine particles comprised of these components, under the assumption that brown carbon and other aerosol components were externally mixed. For all three sites, chromophores were predominately in the accumulation mode with an aerodynamic mean diameter of 0.5 μm, an optically effective size range resulting in predicted particle light absorption being a factor of 2 higher than bulk solution absorption. Fine particle absorption was also measured with a Multi-Angle Absorption Photometer (MAAP) and seven-wavelength Aethalometer. Scattering-corrected aethalometer and MAAP absorption were in good agreement at 670 nm and Mie-estimated absorption based on size-resolved EC data were within 30% of these optical instruments. When applied

  8. Size-resolved measurements of brown carbon and estimates of their contribution to ambient fine particle light absorption based on water and methanol extracts

    Directory of Open Access Journals (Sweden)

    J. Liu

    2013-07-01

    Full Text Available Light absorbing organic carbon, often termed brown carbon, has the potential to significantly contribute to the visible light absorption budget, particularly at shorter wavelengths. Currently, the relative contributions of particulate brown carbon to light absorption, as well as the sources of brown carbon are poorly understood. With this in mind field measurements were made at both urban (Atlanta, and rural (Yorkville sites in Georgia. Measurements in Atlanta were made at both a central site and a road side site adjacent to a main highway near the city center. Fine particle brown carbon optical absorption is estimated based on Mie calculations using direct size resolved measurements of chromophores in filter extracts. Size-resolved atmospheric aerosol samples were collected using a cascade impactor and analyzed for water-soluble organic carbon (WSOC, organic and elemental carbon (OC and EC, and solution light absorption spectra of water and methanol extracts. Methanol extracts were more light-absorbing than water extracts for all size ranges and wavelengths. Absorption refractive indices of the organic extracts were calculated from solution measurements for a range of wavelengths and used with Mie theory to predict the light absorption by fine particles comprised of these components, under the assumption that brown carbon and other aerosol components were externally mixed. For all three sites, chromophores were predominately in the accumulation mode with an aerodynamic mean diameter of 0.5 μm, an optically effective size range resulting in predicted particle light absorption being a factor of 2 higher than bulk solution absorption. Fine particle absorption was also measured with a Multi-Angle Absorption Photometer (MAAP and seven-wavelength Aethalometer. Scattering-corrected aethalometer and MAAP absorption were in good agreement at 670 nm and Mie-estimated absorption based on size-resolved EC data were within 30% of these optical instruments

  9. Gender Recognition from Human-Body Images Using Visible-Light and Thermal Camera Videos Based on a Convolutional Neural Network for Image Feature Extraction.

    Science.gov (United States)

    Nguyen, Dat Tien; Kim, Ki Wan; Hong, Hyung Gil; Koo, Ja Hyung; Kim, Min Cheol; Park, Kang Ryoung

    2017-03-20

    Extracting powerful image features plays an important role in computer vision systems. Many methods have previously been proposed to extract image features for various computer vision applications, such as the scale-invariant feature transform (SIFT), speed-up robust feature (SURF), local binary patterns (LBP), histogram of oriented gradients (HOG), and weighted HOG. Recently, the convolutional neural network (CNN) method for image feature extraction and classification in computer vision has been used in various applications. In this research, we propose a new gender recognition method for recognizing males and females in observation scenes of surveillance systems based on feature extraction from visible-light and thermal camera videos through CNN. Experimental results confirm the superiority of our proposed method over state-of-the-art recognition methods for the gender recognition problem using human body images.

  10. Gender Recognition from Human-Body Images Using Visible-Light and Thermal Camera Videos Based on a Convolutional Neural Network for Image Feature Extraction

    Science.gov (United States)

    Nguyen, Dat Tien; Kim, Ki Wan; Hong, Hyung Gil; Koo, Ja Hyung; Kim, Min Cheol; Park, Kang Ryoung

    2017-01-01

    Extracting powerful image features plays an important role in computer vision systems. Many methods have previously been proposed to extract image features for various computer vision applications, such as the scale-invariant feature transform (SIFT), speed-up robust feature (SURF), local binary patterns (LBP), histogram of oriented gradients (HOG), and weighted HOG. Recently, the convolutional neural network (CNN) method for image feature extraction and classification in computer vision has been used in various applications. In this research, we propose a new gender recognition method for recognizing males and females in observation scenes of surveillance systems based on feature extraction from visible-light and thermal camera videos through CNN. Experimental results confirm the superiority of our proposed method over state-of-the-art recognition methods for the gender recognition problem using human body images. PMID:28335510

  11. Heat shock, visible light or high calcium augment the cytotoxic effects of Ailanthus altissima (Swingle) leaf extracts against Saccharomyces cerevisiae cells.

    Science.gov (United States)

    Popa, Claudia Valentina; Lungu, Liliana; Cristache, Ligia Florentina; Ciuculescu, Crinu; Danet, Andrei Florin; Farcasanu, Ileana Cornelia

    2015-01-01

    To gain new insight into the antimicrobial potential of Ailanthus altissima Swingle, ethanol leaf extracts were evaluated for the antifungal effects against the model yeast Saccharomyces cerevisae. The extracts inhibited the yeast growth in a dose-dependent manner, and this effect could be augmented by heat shock, exposure to visible light or exposure to high concentrations of Ca(2+). Using transgenic yeast cells expressing the Ca(2+)-dependent photoprotein, aequorin, it was found that the leaf extracts induced cytosolic Ca(2+) elevation. Experiments on yeast mutants with defects in Ca(2+) transport demonstrated that the cytotoxicity of the A. altissima leaf extracts (AaLEs) was mediated by transient pulses of Ca(2+) ions which were released into the cytosol predominantly from the vacuole. The investigation of the antifungal synergies involving AaLEs may contribute to the development of optimal and safe combination therapies for the treatment of drug-resistant fungal infections.

  12. Investigation of the light-extraction efficiency in 280 nm AlGaN-based light-emitting diodes having a highly transparent p-AlGaN layer

    Science.gov (United States)

    Yun, Joosun; Hirayama, Hideki

    2017-01-01

    The light-extraction efficiency (LEE) of 280 nm AlGaN-based ultraviolet light-emitting diodes (UV-LEDs) with a highly transparent p-AlGaN layer was investigated using a three-dimensional (3D) finite-difference time-domain method. This investigation clearly demonstrated that two major problems need to be solved to obtain an LED structure that guarantees the high LEE for both TE and TM polarized light emissions. The first problem was shown to be light confined in quantum wells (QW) and the n-AlGaN layer. By analyzing a conventional LED structure with a highly transparent p-AlGaN layer and an AlN/sapphire template, the major cause of the light confinement was confirmed as the total internal reflection (TIR) at the interfaces between the EBL, QW, n-AlGaN, and AlN layers. Especially, light confined in the QWs is severe due to TIR at the interfaces adjacent to them. This light diminishes with time due to absorption. By removing the AlN/sapphire layer beneath the n-AlGaN layer, adopting an Al electrode, introducing cone-shaped pillars on the n-AlGaN layer and having cylindrical holes through the Al electrode, LEEs of 54.3% and 49.3% were attained for the TE and TM polarized emissions, respectively. This result demonstrates that just by offering proper light escape angles directly to the light confining layers, attainment of LEEs of more than 50% is possible. The second problem is severe light absorption by the metal electrode. LEE vs. the reflectivity of the metal electrode was analyzed for several LED structures. In the extracted results, an exponential increase in LEE as the metal reflectivity increases was shown, which means reflection at the interface between the p-AlGaN layer and the metal electrode is repeated several times until the light escapes from the LED. Also, it was shown that once the reflectivity of the metal electrode is more than 90%, any additional small increase in reflectivity increases LEE significantly. These results emphasize that without high

  13. Fabrication of a nano-cone array on a p-GaN surface for enhanced light extraction efficiency from GaN-based tunable wavelength LEDs.

    Science.gov (United States)

    Soh, C B; Wang, B; Chua, S J; Lin, Vivian K X; Tan, Rayson J N; Tripathy, S

    2008-10-08

    We report on the fabrication of a nano-cone structured p-GaN surface for enhanced light extraction from tunable wavelength light emitting diodes (LEDs). Prior to p-contact metallization, self-assembled colloidal particles are deposited and used as a mask for plasma etching to create nano-cone structures on the p-GaN layer of LEDs. A well-defined periodic nano-cone array, with an average cone diameter of 300 nm and height of 150 nm, is generated on the p-GaN surface. The photoluminescence emission intensity recorded from the regions with the nano-cone array is increased by two times as compared to LEDs without surface patterning. The light output power from the LEDs with surface nano-cones shows significantly higher electroluminescence intensity at an injection current of 70 mA. This is due to the internal multiple scattering of light from the nano-cone sidewalls. Furthermore, we have shown that with an incorporation of InGaN nanostructures in the quantum well, the wavelength of these surface-patterned LEDs can be tuned from 517 to 488 nm with an increase in the injection current. This methodology may serve as a practical approach to increase the light extraction efficiency from wavelength tunable LEDs.

  14. ZnO nanorods/graphene/Ni/Au hybrid structures as transparent conductive layer in GaN LED for low work voltage and high light extraction

    Science.gov (United States)

    Xu, Kun; Xie, Yiyang; Ma, Huali; Du, Yinxiao; Zeng, Fanguang; Ding, Pei; Gao, Zhiyuan; Xu, Chen; Sun, Jie

    2016-12-01

    In this paper, by virtue of one-dimensional ZnO nanorods and two-dimensional graphene film hybrid structures, both the enhanced current spreading and enhanced light extraction were realized at the same time. A 1 nm/1 nm Ni/Au layer was used as an interlayer between graphene and pGaN to form ohmic contact, which makes the device have a good forward conduction properties. Through the comparison of the two groups of making ZnO nanorods or not, it was found that the 30% light extraction efficiency of the device was improved by using the ZnO nanorods. By analysis key parameters of two groups such as the turn-on voltage, work voltage and reverse leakage current, it was proved that the method for preparing surface nano structure by hydrothermal method self-organization growth ZnO nanorods applied in GaN LEDs has no influence to device's electrical properties. The hybrid structure application in GaN LED, make an achievement of a good ohmic contact, no use of ITO and enhancement of light extraction at the same time, meanwhile it does not change the device structure, introduce additional process, worsen the electrical properties.

  15. Influence of pH, concentration and light on stability of allicin in garlic (Allium sativum L.) aqueous extract as measured by UPLC.

    Science.gov (United States)

    Wang, Haiping; Li, Xixiang; Liu, Xinyan; Shen, Di; Qiu, Yang; Zhang, Xiaohui; Song, Jiangping

    2015-07-01

    Garlic is one of the most important bulb vegetables and is mainly used as a spice or flavoring agent for foods. It is also cultivated for its medicinal properties, attributable to sulfur compounds, of which allicin is the most important. However, the stability of allicin in garlic extract is not well understood. In this study, using UPLC, the stability of allicin extracted in water from garlic was evaluated in phosphate buffer at different temperatures under light and dark conditions. At room temperature, allicin in aqueous extract was most stable at pH 5-6 but degraded quickly at lower or higher pH. It began to degrade within 0.5 h and was not detectable after 2 h when the pH was higher than 11 or lower than 1.5. It degraded quickly when the temperature was higher than 40 °C and especially higher than 70 °C. At room temperature, allicin in water could be stored for 5 days without obvious degradation. Higher concentrations of allicin in solution were somewhat more stable than low concentrations. Allicin extract was sensitive to pH and temperature of storage but not to light. Higher-concentration allicin solution was more stable. © 2014 Society of Chemical Industry.

  16. Improved light extraction of InGaN/GaN blue LEDs by GaOOH NRAs using a thin ATO seed layer.

    Science.gov (United States)

    Lee, Hee Kwan; Joo, Dong Hyuk; Kim, Myung Sub; Yu, Jae Su

    2012-08-16

    We investigated the effect of gallium oxide hydroxide (GaOOH) nanorod arrays (NRAs) on the light extraction of InGaN/GaN multiple quantum well blue light-emitting diodes (LEDs). GaOOH NRAs were prepared on an indium tin oxide electrode (ITO) layer of LEDs by electrochemical deposition method. The GaOOH NRAs with preferred orientations were grown on the ITO surface by sputtering a thin antimony-doped tin oxide seed layer, which enhances heterogeneous reactions. Surface density and coverage were also efficiently controlled by the different growth voltages. For LEDs with GaOOH NRAs grown at -2 V, the light output power was increased by 22% without suffering from any serious electrical degradation and wavelength shift as compared with conventional LEDs.

  17. Evaluation of the temperature-dependent internal quantum efficiency and the light-extraction efficiency in a GaN-based blue light-emitting diode by using a rate equation model

    Science.gov (United States)

    Choi, Young-Hwan; Ryu, Guen-Hwan; Ryu, Han-Youl

    2016-10-01

    The internal quantum efficiency (IQE) and the light extraction efficiency (LEE) of a GaN-based blue light-emitting diode (LED) are evaluated separately in the temperature range between 20 to 80 °C. The theoretical IQE model based on the carrier rate equation of semiconductors is applied to determine the IQE and the LEE separately from a measured external quantum efficiency (EQE) versus current relation for the LED sample. While the peak EQE of the measured sample decreases by 3.2 % as the temperature increases from 20 to 80 °C, it is found that the peak IQE decreases by 4.5 % and the LEE increases by 1.5 %.

  18. Great enhancement in the excitonic recombination and light extraction of highly ordered InGaN/GaN elliptic nanorod arrays on a wafer scale.

    Science.gov (United States)

    Zhuang, Zhe; Guo, Xu; Liu, Bin; Hu, Fengrui; Dai, Jiangping; Zhang, Yun; Li, Yi; Tao, Tao; Zhi, Ting; Xie, Zili; Ge, Haixiong; Wang, Xiaoyong; Xiao, Min; Wang, Tao; Shi, Yi; Zheng, Youdou; Zhang, Rong

    2016-01-01

    A series of highly ordered c-plane InGaN/GaN elliptic nanorod (NR) arrays were fabricated by our developed soft UV-curing nanoimprint lithography on a wafer. The photoluminescence (PL) integral intensities of NR samples show a remarkable enhancement by a factor of up to two orders of magnitude compared with their corresponding as-grown samples at room temperature. The radiative recombination in NR samples is found to be greatly enhanced due to not only the suppressed non-radiative recombination but also the strain relaxation and optical waveguide effects. It is demonstrated that elliptic NR arrays improve the light extraction greatly and have polarized emission, both of which possibly result from the broken structure symmetry. Green NR light-emitting diodes have been finally realized, with good current-voltage performance and uniform luminescence.

  19. Extraction of Parameters of Random Self-Affine Fractal Surfaces from Light Scattered Intensity by Levenberg-Marquardt Algorithm

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ning-Yu; TENG Shu-Yun; SONG Hong-Sheng; LIU Gui-Yuan; CHENG Chuan-Fu

    2009-01-01

    A method for simultaneously extracting the parameters of self-affine fractal surfaces from a single experimental profile of scattered intensity data is proposed. The Levenberg-Marquardt algorithm is introduced to fit the theoretical equation for the scattering intensity profile to the experimental data.A precision system is designed for acquisition of scattering intensity data using the Boxcar integration technique. The surface parameters extracted (root-mean-square roughness w,lateral correlation length ξ,and roughness exponent a) are compared to those obtained using atomic force microscopy.

  20. Far-infrared-light shadowgraphy for high extraction efficiency of extreme ultraviolet light from a CO2-laser-generated tin plasma

    Science.gov (United States)

    Matsukuma, Hiraku; Hosoda, Tatsuya; Suzuki, Yosuke; Yogo, Akifumi; Yanagida, Tatsuya; Kodama, Takeshi; Nishimura, Hiroaki

    2016-08-01

    The two-color, double-pulse method is an efficient scheme to generate extreme ultraviolet light for fabricating the next generation semiconductor microchips. In this method, a Nd:YAG laser pulse is used to expand a several-tens-of-micrometers-scale tin droplet, and a CO2 laser pulse is subsequently directed at the expanded tin vapor after an appropriate delay time. We propose the use of shadowgraphy with a CO2 laser probe-pulse scheme to optimize the CO2 main-drive laser. The distribution of absorption coefficients is derived from the experiment, and the results are converted to a practical absorption rate for the CO2 main-drive laser.

  1. Light extraction efficiency enhancement of GaN-based blue LEDs based on ITO/ InxO ohmic contacts with microstructure formed by annealing in oxygen.

    Science.gov (United States)

    Luo, Yi; Bai, Yiming; Han, Yanjun; Li, Hongtao; Wang, Lai; Wang, Jian; Sun, Changzheng; Hao, Zhibiao; Xiong, Bing

    2016-05-16

    Indium tin oxide (ITO)/ indium oxide (InxO) double layer structure was adopted as the transparent conduction and light scattering function layer to improve the light extraction efficiency of the GaN-based blue LEDs. The double layer structure was first deposited in one run by electron beam evaporation using ITO and Indium as the source respectively, and then annealed in an oxygen environment. This method can fabricate transparent electrode with microstructure and low specific contact resistivity one time free from lithography and etching, which makes the fabrication process simple and at a ower cost. For the 220 nm ITO/ 170 nm InxO double layer sample annealed at 600°C for 15 min in oxygen, measurement results show that its root mean square of roughness of the surface microstructure can be as high as 85.2 nm which introduces the strongest light scattering. Its light transmittance at 450 nm can maintain 92.4%. At the same time, it can realize lower specific contact resistivity with p-InGaN. Compared with the GaN-based blue LEDs with only 220 nm ITO electrode, the light output power of the LEDs with 220 nm ITO/ 170 nm InxO double layer structure can be increased about 58.8%, and working voltage at 20 mA injection current is decreased about 0.23 V due to the enhanced current spreading capability. The light output power improvement is also theoretically convinced by finite difference time domain simulations.

  2. Successful Capture, Extraction and Identification of Hypervelocity CM2 Meteorite Fragments Shot by Light-Gas Gun

    Science.gov (United States)

    Snead, C.; Westphal, A. J.; Dominguez, G.; Zolensky, M. E.

    2003-01-01

    Here we report the successful capture, extraction and identification of two fragments of a CM2 meteorite (ALH83100) into lowdensity aerogel. The shot was carried out at the AVGR at NASAARC. A mixture of powdered ALH83100 and borosilicate glass microspheres was shot at 4.55.0 km/sec into 50 mg cm silicate aerogel.

  3. Femtosecond pump probe spectroscopy for the study of energy transfer of light-harvesting complexes from extractions of spinach leaves

    Directory of Open Access Journals (Sweden)

    L. van Rensburg

    2010-01-01

    Full Text Available Measurements of ultrafast transient processes, of temporal durations in the picosecond and femtosecond regime, are made possible by femtosecond pump probe transient absorption spectroscopy. Such an ultrafast pump probe transient absorption setup has been implemented at the CSIR National Laser Centre and has been applied to investigate energy transfer processes in different parts of photosynthetic systems. In this paper we report on our first results obtained with Malachite green as a benchmark. Malachite green was chosen because the lifetime of its excited state is well known. We also present experimental results of the ultrafast energy transfer of light-harvesting complexes in samples prepared from spinach leaves. Various pump wavelengths in the range 600–680 nm were used; the probe was a white light continuum spanning 420–700 nm. The experimental setup is described in detail in this paper. Results obtained with these samples are consistent with those expected and achieved by other researchers in this field.

  4. Extraction of Surface Roughness from the Central δ-peak of Light Scattering Using a Multi-wavelength Ar+ Laser

    Institute of Scientific and Technical Information of China (English)

    LIU Deli; QI Dongping; CHENG Chuanfu

    2000-01-01

    In this paper, a new light scattering method for measuring the roughness of random surfaces is proposed. The method is based on the relation between the specularly reflected intensity Is, i.e., the central δ-peak intensity and wave vector component kz. The linear fit of the logarithm graph of the normalized central δ-peak intensity Isr versus k2z, whose variation is induced by changing illuminating wavelength, gives the square of the surface roughness w. The roughnesses of 6 silicon backside samples were measured.

  5. Fernblock (Polypodium leucotomos Extract: Molecular Mechanisms and Pleiotropic Effects in Light-Related Skin Conditions, Photoaging and Skin Cancers, a Review

    Directory of Open Access Journals (Sweden)

    Concepcion Parrado

    2016-06-01

    Full Text Available Healthier life styles include increased outdoors time practicing sports and walking. This means increased exposure to the sun, leading to higher risk of sunburn, photoaging and skin cancer. In addition to topical barrier products, oral supplementations of various botanicals endowed with antioxidant activity are emerging as novel method of photoprotection. Polypodium leucotomos extract (PL, commercial name Fernblock®, IFC Group, Spain is a powerful antioxidant due to its high content of phenolic compounds. PL is administered orally, with proven safety, and it can also be used topically. Its mechanisms include inhibition of the generation and release of reactive oxygen species (ROS by ultraviolet (UV light. It also prevents UV- and ROS-induced DNA damage with inhibition of AP1 and NF-κB and protection of natural antioxidant enzyme systems. At the cellular level, PL decreases cellular apoptosis and necrosis mediated UV and inhibits abnormal extracellular matrix remodeling. PL reduces inflammation, prevents immunosuppression, activates tumor suppressor p53 and inhibits UV-induced cyclooxygenase-2 (COX-2 enzyme expression. In agreement with increased p53 activity, PL decreased UV radiation-induced cell proliferation. PL also prevents common deletions mitochondrial DNA damage induced by UVA, and MMP-1 expression induced Visible Light and Infrared Radiation. These cellular and molecular effects are reflected in inhibitions of carcinogenesis and photoaging.

  6. [Effect of stress actions on some hematologic and biochemical parameters of rat blood and on energetic intermolecular interactions in lipid extract under effect of light radiation].

    Science.gov (United States)

    Zabelinskiĭ, S A; Chebotareva, M A; Tavrovskaia, T V; Skverchinskaia, E A; Shukoliukova, E P; Maslov, M N; Krivchenko, A I

    2012-01-01

    Comparative study has been carried of effect of the three-day long starvation, running, and their combination on morphological parameters of rat blood, lipid metabolism, and activity of blood Na,K-ATPase. Different effect has been shown of these stress factors on the blood erythrocyte composition. Starvation is accompanied by the most pronounced release of stored erythrocyte into blood, which results in a significant decrease both of the total amount of reticulocytes and the complete absence of reticulocytes of the I stage of maturity (the youngest). The running on treadmill led to a significant increase of the total amount of blood reticulocytes and to multiple increase of immature reticulocytes (RC-I and RC-II), which can indicate some stress of the bone marrow erythroid stem line. The curve of acid resistance of blood reticulocytes has shown the animal to experience the greatest stress at a combination of starvation and running. Starvation and running produced different effects on blood lipid characteristics. The content of triacylglycerides (TAG) in blood rose by 40% at starvation and decreased by 30% at running, a similar tendency being found for index of atherogeneity. The fatty acid composition of blood phospholipids at running and its combination with starvation practically did not differ from control. A change of Na,K-ATPase, which is so characteristic of reaction to various kinds of stress, sharply fell at starvation (by 22%), but increased at running (by 13%) and decreased markedly at combination of these actions. Absorption spectra of lipid extracts of the whole blood of the rats submitted to various stress actions showed that extracted from blood (at different amount depending on the kind of action) is an organic substance with coupled bonds, which absorbs light in the diapason of 360-620 nm. The absorption of light in the diapason of 400-410 nm has been found to belong to the Soret band of ferroheme and ferriheme. The shift of the Soret band indicates

  7. Kinetic freeze-out temperature and flow velocity extracted from transverse momentum spectra of final-state light flavor particles produced in collisions at RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Hua-Rong; Liu, Fu-Hu [Shanxi University, Institute of Theoretical Physics, Shanxi (China); Lacey, Roy A. [Stony Brook University, Departments of Chemistry and Physics, Stony Brook, NY (United States)

    2016-04-15

    The transverse momentum spectra of final-state light flavor particles produced in proton-proton (p-p), copper-copper (Cu-Cu), gold-gold (Au-Au), lead-lead (Pb-Pb), and proton-lead (p -Pb) collisions for different centralities at relativistic heavy ion collider (RHIC) and large hadron collider (LHC) energies are studied in the framework of a multisource thermal model. The experimental data measured by the STAR, CMS, and ALICE Collaborations are consistent with the results calculated by the multi-component Erlang distribution and Tsallis Statistics. The effective temperature and real temperature (kinetic freeze-out temperature) of the interacting system at the stage of kinetic freeze-out, the mean transverse flow velocity and mean flow velocity of particles, and the relationships between them are extracted. The dependences of effective temperature and mean (transverse) momentum on rest mass, moving mass, centrality, and center-of-mass energy, and the dependences of kinetic freeze-out temperature and mean (transverse) flow velocity on centrality, center-of-mass energy, and system size are obtained. (orig.)

  8. Anti-apoptotic effects of Curcuma longa L. extract and its curcuminoids against blue light-induced cytotoxicity in A2E-laden human retinal pigment epithelial cells.

    Science.gov (United States)

    Park, Sang-Il; Lee, Eun Hye; Kim, So Ra; Jang, Young Pyo

    2017-03-01

    The purpose of the study was to investigate the protective effect of the Curcuma longa L. extract (CLE) and its curcuminoids against blue light-induced cytotoxicity in human retinal pigment epithelial (RPE) cells laded with A2E. A2E has been concerned in age-related macular degeneration (AMD). To perform this study, A2E-accumulated ARPE-19 cells were exposed to blue light to induce cytotoxicity. The cytotoxicity and apoptotic gene expression levels were evaluated using a lactate dehydrogenase (LDH) assay and real-time PCR analysis, respectively. Curcuma longa L. extract was found to exert a protective effect in a dose-dependent manner. At a concentration of 15 μm, curcumin, demethoxycurcumin and bisdemethoxycurcumin exerted significant protective effects against blue light-induced cytotoxicity. Treatment with CLE and curcuminoids meaningfully reduced the mRNA levels of c-Abl and p53, which was known to be augmented in apoptotic RPE cells. Demethoxycurcumin and bisdemethoxycurcumin were found to inhibit p38 expression, which is increased in blue light-irradiated A2E-accumulated RPE cells. Curcuma longa L. extract and its curcuminoids provided significant protection against photooxidative damage and apoptosis in the RPE cells. Our results suggest that curcuminoids may show potential in the treatment of AMD. © 2017 Royal Pharmaceutical Society.

  9. 微波光波组合辐射辅助提取赤小豆黄酮的机制分析%Study on extraction mechanism of total flavone from red phaseolus bean by microwave and light wave radiation

    Institute of Scientific and Technical Information of China (English)

    彭游; 李同建

    2011-01-01

    考察赤小豆总黄酮的微波光波组合辐射提取法,并对提取机理进行分析。发现微波光波提取法以功率800W(微波55%与光波45%)加热6min后,70%乙醇萃取得总黄酮,总黄酮的提取率为1.24%,与相应的常规加热回流提取法接近,该法有操作简单快速、成本低等优点。利用荧光显微镜FM、IR对微波提取机理进行初步研究表明.微波光波可能是从对植物组织细胞结构的影响上来改善次生代谢产物的提取效率。%The extraction method and mechanism of total flavonoids from red phaseolus bean had been studied using microwave and light wave radiation. The total flavonoids were extracted with ethyl alcohol after heating the sample for 6min with power 800W (microwave 55% and light wave 45%). The extraction rate of total flavonoids was 1.24%,which closes with the conventional extraction process. This method has many merits,such as simple, rapid,low cost,and so on. Extraction mechanism was investigated preliminarily with high magnification fluorescence microscope FM,IR. It indicated that the improvement of extraction efficiency of secondary metabolite maybe due to the plant tissue cell structure that were broken by microwave and light wave.

  10. 利用单层密排的纳米球提高发光二极管的出光效率∗%Light-extraction enhancement of GaN-based LEDs by closely-packed nanospheres monolayer

    Institute of Scientific and Technical Information of China (English)

    陈湛旭; 万巍; 何影记; 陈耿炎; 陈泳竹

    2015-01-01

    GaN based light-emitting diodes (LEDs) have been attracting a great deal of interest due to their capability in emitting a spectrum from ultraviolet to green and their applications in traffic signals, displays and solid-state lighting. However, the high efficiency of LED is still obstructed by light-extraction efficiency. In this work, we propose that light-extraction efficiency of GaN-based blue LED should be improved by a self-assembled monolayer of polystyrene spheres. The GaN-based LED grown on sapphire substrate emits the light mainly from the indium tin oxide (ITO) transparent electrode. And the hexagonal closely-packed polystyrene sphere monolayer is formed onto the ITO layer. In order to study the light-extraction efficiency affected by the size of nanosphere, nanosphere monolayers of different sizes are prepared onto the ITO layer, and the diameters of the polystyrene spheres are 250, 300, 450, 600 and 950 nm, respectively. The electroluminescence results show that using polystyrene sphere monolayer can improve the light-extraction efficiency compared with using the conventional LEDs, and the light-extraction efficiency reaches a maximum when the average size of spheres (450 nm) approximates to the wavelength (465 nm) of that light. The light output power of the LED with polystyrene sphere of the optimum size is experimentally enhanced by 1.34 and 1.25 times under the injection currents of 20 and 150 mA, respectively. In order to explain the physical mechanism of the light-extraction enhancement, we carried out the three-dimensional finite difference time-domain simulation thereby calculate the transmission spectrum of the structure. The results of simulation show that the incident light beyond the critical angle can be partly extracted when the surface of LED has a polystyrene sphere monolayer, leading to an enhanced light-extraction efficiency. So the nanosphere monolayer acts as a two-dimensional diffraction lattice which behaves as a light scattering

  11. Different chemical composition of free light, occluded light and extractable SOM fractions in soils of Cerrado and tilled and untilled fielfds, Minas Gerais, Brazil: a pyrolysis-GC/MS study

    NARCIS (Netherlands)

    Buurman, P.; Roscob, R.

    2011-01-01

    To investigate both the effect of land-use systems on SOM characteristics and the effect of occlusion in aggregates on chemical composition of the occluded fraction, SOM fractions of soils under Cerrado, no-tillage and conventional tillage, were investigated. Free light, occluded light and extractab

  12. The Filth and the Fury 101

    Science.gov (United States)

    Moyer, Matthew

    2007-01-01

    Many a bar fight has broken out over punk rock's birth. Fans tend to split into two camps: those who credit the Ramones' first appearance at CBGB in New York City circa 1974 and those who point to the early galvanizing Sex Pistols shows in London around 1975-76. It is probably more accurate to say the New York and London scenes are two sides of…

  13. Solid-phase extraction approach for phospholipids profiling by titania-coated silica microspheres prior to reversed-phase liquid chromatography-evaporative light scattering detection and tandem mass spectrometry analysis.

    Science.gov (United States)

    Bian, Juan; Xue, Yun; Yao, Kai; Gu, Xue; Yan, Chao; Wang, Yan

    2014-06-01

    A novel strategy for selectively adsorbing phospholipids (PLs) on titania-coated silica core-shell microspheres (TiO2/SiO2) was developed. The TiO2/SiO2 microspheres were prepared through water-vapor-induced internal hydrolysis and then characterized by SEM, UV-vis spectroscopy, X-ray diffraction, and measurements of Brunauer-Emmett-Teller surface area. Analyses showed that the titania layer was uniformly distributed onto the surface of silica particles. The TiO2/SiO2 microspheres were employed as sorbent in solid-phase extraction (SPE), and their absorptive ability was investigated by reversed-phase liquid chromatography-evaporative light scattering detection (RPLC-ELSD). Important factors that affect the extraction, such as loading buffer, eluting buffer, and elution volume, were investigated in detail and optimized by using standard samples. Results reveal that the developed SPE approach had higher recoveries for PLs than that based on pure TiO2 particles. The proposed SPE method was used for extraction of PLs from serum and showed great potential for identifying more kinds of endogenous PL metabolites by ultra performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF MS). The proposed SPE method with the composite sorbent was used to screen PLs from a biological matrix with high selectivity and efficiency. This approach is a promising method for selective extraction of PLs in lipidomics or phospholipidomics.

  14. Effect of Nd:YAG laser light on post-extractive socket healing in rats treated with zoledronic acid and dexamethasone

    Science.gov (United States)

    Mergoni, Giovanni; Merigo, Elisabetta; Passerini, Pietro; Corradi, Domenico; Maestri, Roberta; Bussolati, Ovidio; Bianchi, Massimiliano; Sala, Roberto; Govoni, Paolo; Namour, Samir; Vescovi, Paolo

    2016-03-01

    Introduction The effect of low level laser therapy (LLLT) on the healing process could be useful for the prevention of post-extractive Bisphosphonate-related Osteonecrosis of the Jaws (BRONJ). The aim of the study was to investigate the effect of LLLT on the post-extractive socket healing in rats treated with zoledronic acid and dexamethasone. Material and Methods Thirty male Sprague-Dawley rats were divided in 4 groups: control group (C, n = 5), laser group (L, n = 5), treatment group (T, n = 10) and treatment plus laser group (T+L, n = 10). Rats of group T and T+L received zoledronate 0,1 mg/Kg and dexamethasone 1 mg/Kg every 2 days for 10 weeks. Rats of group C and L were infused with vehicle. After 9 weeks the first maxillary molars were extracted in all rats. Rats of groups L and T+L received laser therapy (Nd:YAG, 1064 nm, 1.25W, 15Hz, 5 min, 14.37 J/cm2) in the socket area at days 0, 2, 4 and 6 after surgery. At 8 days from extraction, the sockets were clinically assessed with a grading score and the wound area was measured with a dedicate software. Histomorphometric evaluation and western blot analysis of osteopontin and osteocalcin expression were performed. Results Group T+L showed a trend toward a better clinical grading score compared to group T (grade I 22% Vs 28 % - grade II 56% Vs 28% - grade III 22% Vs 44%, respectively). The average wound area was similar among the groups. Inhibition of osteoclastic alveolar bone resorption was found in groups T and T+L (Plaser irradiation. Conclusion Our findings suggest that laser irradiation after tooth extraction can promote osteoblast differentiation, as demonstrated by the higher expression of osteocalcin. Thus, laser irradiation could be considered a way to improve socket healing in conditions at risk for MRONJ development.

  15. Extraction of Y2 O3 :Cr(3+) nanophosphor by eco-friendly approach and its suitability for white light-emitting diode applications.

    Science.gov (United States)

    Prasanna Kumar, J B; Ramgopal, G; Sunitha, D V; Prasad, B Daruka; Nagabhushana, H; Vidya, Y S; Anantharaju, K S; Prashantha, S C; Sharma, S C; Prabhakara, K R

    2017-05-01

    Cr(3)(+) -doped Y2 O3 (0.5-9 mol%) was synthesized by a simple solution combustion method using Aloe vera gel as a fuel/surfactant. The final obtained product was calcined at 750°C for 3 h, which is the lowest temperature reported so far for the synthesis of this compound. The calcined product was confirmed for its crystallinity and purity by powder X-ray diffraction (PXRD) studies which showed a single-phase nano cubic phosphor. The particles size estimated by Scherrer formula was in the range of 6-19 nm. The UV-vis spectra showed absorption bands at 198, 272 and 372 nm having band gap energy in the range 4.00-4.26 eV. In order to investigate the possibility of its use in white light emitting display applications, the photoluminescence properties of Cr(3)(+) -doped Y2 O3 nanophosphors were studied at an excitation wavelength in the near ultraviolet (UV) light region (361 nm). The emission spectra consisted of emission peaks in the blue ((4) F9/2  → (6) H15/2 ), orange ((4) F9/2  → (6) H13/2 ) and red ((4) F9/2  → (6) H11/2 ) regions. The CIE coordinates (0.33, 0.33) lie in the white light region. Hence Y2 O3 :Cr(3)(+) can be used for white light-emitting diode (LED) applications. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Lighting: Green Light.

    Science.gov (United States)

    Maniccia, Dorine

    2003-01-01

    Explains that by using sustainable (green) building practices, schools and universities can make their lighting systems more efficient, noting that embracing green design principles can help schools attract students. Discusses lighting-control technologies (occupancy sensing technology, daylighting technology, and scheduling based technologies),…

  17. Efficient "light-soaking"-free inverted organic solar cells with aqueous solution processed low-temperature ZnO electron extraction layers.

    Science.gov (United States)

    Wei, Wei; Zhang, Chunfu; Chen, Dazheng; Wang, Zhizhe; Zhu, Chunxiang; Zhang, Jincheng; Lu, Xiaoli; Hao, Yue

    2013-12-26

    Low-temperature processes are unremittingly pursued in the fabrication of organic solar cells. The paper reports that the highly efficient and "light-soaking"-free inverted organic solar cell can be achieved by using ZnO thin films processed from the aqueous solution method at a low temperature. The inverted organic solar with an aqueous-processed ZnO thin film annealed at 150 °C shows an efficiency of 3.79%. Even when annealed at a temperature as low as 80 °C, the device still shows an efficiency of 3.71%. With the proper annealing temperature of 80 °C, the flexible device, which shows an efficiency of 3.56%, is fabricated on PET. This flexible device still keeps the efficiency above 3.40% after bent for 1000 times with a curvature radius of 50 mm. In contrast, a low annealing temperature leads to an inferior device performance when the ZnO thin film is processed from the widely used sol-gel method. The device with sol-gel processed ZnO annealed at 150 °C only shows a PCE of 1.3%. Furthermore, the device shows a strong "light-soaking" effect, which is not observed in the device containing an aqueous-processed ZnO thin film. Our results suggest that the adopted aqueous solution method is a more efficient low temperature technique, compared with the sol-gel method.

  18. Preparation of low nucleic acid yeast extract by a mesotherm/light-salt method%中温淡盐法制备低核酸酵母抽提物的工艺研究

    Institute of Scientific and Technical Information of China (English)

    王斌; 黄丽娜; 邱丽娟

    2014-01-01

    Using a novel mesotherm/light-salt method for the removal of nucleic acid , the high quality , low nucleic acid yeast extract was successfully prepared .This technique was simple and short in processing time under 70℃.By using low amount of sodium chlo-ride, desalting is not required.Moreover, content of nucleic acid was reduced by over 70%.Further more, the yeast product had a light color with a tasty meat flavor , suitable for food processing .In addition , this technique produced a high-yield high-purity nucleic acid byproduct .Mesotherm/light-salt technique broadened the application field of yeast extract products , provided a solution for obtai-ning safe and nutritious yeast products to individuals with uric acid in the high side or gout .%通过建立一种新的酵母核酸中温淡盐去除法,成功研制出品质优良的低核酸酵母抽提物。工艺简单,处理时间短,温度不超过70℃,可避免高温对酵母营养物质的破坏;该法氯化钠用量少,无需脱盐处理,易产业化及应用推广;研究制备的酵母抽提物,核酸去除量达70%以上,色浅、肉香味鲜,适合食品加工。同时,附加得到高提取率、高纯度的核酸。中温淡盐法去除酵母核酸的技术,扩展了酵母制品的应用领域,更为尿酸偏高及痛风人群食用安全营养的酵母食品提供了解决方案。

  19. LIGHT-PENCIL COORDINATE POSITIONER,

    Science.gov (United States)

    information sources such as radar and IFF PPI repeaters and computer displays. A light pencil which detects and controls a positionand intensity...position the video gate which extracts desired signals from the radar/IFF returns without requiring the operator to hold the pencil in position. The light ...to-one light pencil motion to marker motion. Except for the light detection photomultipler, the entire design is solid state. (Author)

  20. Responsive City Lighting

    DEFF Research Database (Denmark)

    Poulsen, Esben Skouboe; Andersen, Hans Jørgen; Jensen, Ole B.

    This paper presents and discusses perspectives extracted from two interviews conducted during the experiments Urban Responsive Lighting. The two experts embody two different fields related to city lighting: architecture & public lighting industry. The representatives were invited to the test......-site, where 15 LED RGB Park lamps, controlled driven by a wind sensor, mobile phone applications or by thermal camera tracking. According to the specialists are the social and aesthetical dimensions more interesting than the energy use cases and efficiency. This motivates an interdisciplinary discussion...

  1. Public lighting.

    NARCIS (Netherlands)

    Schreuder, D.A.

    1986-01-01

    The function of public lighting and the relationship between public lighting and accidents are considered briefly as aspects of effective countermeasures. Research needs and recent developments in installation and operational described. Public lighting is an efficient accident countermeasure, but

  2. Detection of related substances in polyene phosphatidyl choline extracted from soybean and in its commercial capsule by comprehensive supercritical fluid chromatography with mass spectrometry compared with HPLC with evaporative light scattering detection.

    Science.gov (United States)

    Jiang, Qikun; Liu, Wanjun; Li, Xiaoting; Zhang, Tianhong; Wang, Yongjun; Liu, Xiaohong

    2016-01-01

    Supercritical fluid chromatography with tandem mass spectrometry was used to comprehensively profile polyene phosphatidyl choline (PPC) extracted from soybean. We achieved an efficient chromatographic analysis using a BEH-2EP column (3 × 100 mm(2) , 1.7 μm) with a mobile phase consisting of CO2 and a cosolvent in gradient combination at a flow rate of 1.0 mL/min. The cosolvent consisted of methanol, acetonitrile, and water (containing 10 mM ammonium acetate and 0.2% formic acid). The total single-run time was 7 min. We used this method to accurately detect ten different phospholipids (PLs) during extraction. The limits of quantification for phosphatidyl choline, lyso-phosphatidylcholine (LPC), phosphatidic acid (PA), sphingomyelin, phosphatidyl glycerol, phosphatidyl inositol (PI), cholesterol, cardiolipin, phosphatidyl serine, and phosphatidyl ethanolamine (PE) were 20.6, 19.52, 1.21, 2.38, 0.50, 2.28, 54.3, 0.60, 0.65, and 4.85 ng/mL, respectively. However, adopting the high-performance liquid chromatography with evaporative light scattering detection method issued by the China Food and Drug Administration, only PA, LPC, PE, PI, and PPC could be analyzed accurately, and the limits of quantification were 33.89, 60.5, 30.3, 10.9, and 61.79 μg/mL, respectively. The total single-run time was at the least 20 min. Consequently, the supercritical fluid chromatography with tandem mass spectrometry method was more suitable for the analysis of related PLs.

  3. WOW: light print, light propel, light point

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Bañas, Andrew Rafael; Aabo, Thomas

    2012-01-01

    anywhere in a sample at any orientation using real-time 3D optical micromanipulation with six degrees of freedom. One of the key aspects of our demonstrated WOWs is the change in direction of in-coupled light and the marked increase in numerical aperture of the out-coupled light. Hence, each light...... propelled WOW can tap from a relatively broad incident beam and generate a much more tightly confined light at its tip. The presentation contains both numerical simulations related to the propagation of light through a WOW and preliminary experimental demonstrations on our BioPhotonics Workstation...

  4. 基于结构光扫描的轴类锻件轴线快速提取%An axis extraction method based on structured light measurement in shaft free-forging

    Institute of Scientific and Technical Information of China (English)

    朱志鹏; 杨延竹; 洪运

    2016-01-01

    在基于结构光的在线测量系统中,采集到的点云数据反映了工件关键参数信息。结合轴类零件的特征,重点介绍了一种通过椭圆最小二乘拟合来提取轴线的方法,这也是后续三维重构与参数计算的基础。%In the online measurement system based on line structured light,the key parameters of work-piece are contained in point clouds collected from measuring system. According to the process characteristics of shaft free-forging,a method of extracting axis by ellipse fitting is introduced. The precision of axis is important for three-di-mensional reconstruction and key parameters calculation. The feasibility and validity is tested by experiments as well in this study.

  5. Quantitative analysis of acankoreoside A and acankoreagenin in the leaves of Schefflera octophylla and Schefflera actinophylla using pressurized liquid extraction and high-performance liquid chromatography coupled with evaporative light scattering detection.

    Science.gov (United States)

    Cao, Kai-Yue; Qiao, Chun-Feng; Zhao, Jing; Xie, Jing; Li, Shao-Ping

    2015-07-01

    A rapid method based on pressurized liquid extraction followed by high-performance liquid chromatography coupled with evaporative light scattering detection was firstly developed for the quantitative analysis of two bioactive triterpenoids (acankoreoside A and acankoreagenin) in the leaves of Schefflera octophylla and Schefflera actinophylla. The analysis was performed on an Agilent Zorbax SB-Aq column (4.6 × 50 mm, 3.5 μm) with gradient elution of 0.1% formic acid and acetonitrile. Calibration curves of two analytes showed good linearity (R(2) > 0.9990) within the tested ranges. This novel method is simple, rapid and accurate, and the results of quantification showed that contents of each investigated compound is significant high in natural S. octophylla (6.36-14.83%), which indicated that natural S. octophylla as potential medicinal resource. Furthermore, hierarchical clustering analysis based on the typical peaks of acankoreoside A and acankoreagenin from the 17 tested samples showed that natural and cultured Schefflera species were in different clusters, which could provide a means of discriminating between Schefflera species from different origins. Thus, acankoreoside A and acankoreagnin could be selected markers for quality control of S. octophylla and S. actinophylla.

  6. Wide reflected angle DBR red light LED

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The coupled DBR LED with one DBR for reflecting normal incidence light and the other for reflecting inclined incidence light has been grown by MOCVD. For improving the conventional DBR which was used to increase light extraction efficiency in A1GaInP red light LED is analyzed. At 20 mA Dc injection current, the LED peak wave length is 630 nm, and the light intensity of on axis is 137 mcd. The output light power is 2.32 mW. The light intensity and output light power have been improved compared with the conventional LEDs.

  7. "Tangible Lights"

    DEFF Research Database (Denmark)

    Sørensen, Tor; Merritt, Timothy; Andersen, Oskar

    2015-01-01

    While there has been much focus on tangible lighting interfaces embedded in physical objects and smartphones as remote control, there has not been sufficient attention on how the expressivity of bodily movement can be used when designing interactions with light. Therefore, we investigate interact...... knowledge from the tangible world. Tangible Lights has been subject to initial evaluations.......While there has been much focus on tangible lighting interfaces embedded in physical objects and smartphones as remote control, there has not been sufficient attention on how the expressivity of bodily movement can be used when designing interactions with light. Therefore, we investigate...... interaction with lighting technology beyond the smartphone and physical controllers. We examine the usefulness of the in-air gestural interaction style for lighting control. We bring forward "Tangible Lights", which serves as a novel interface for in-air interaction with lighting, drawing on existing...

  8. From light to knowledge

    CERN Multimedia

    Globe Info

    2011-01-01

    An evening in two parts with Fabio Barblan. 1/ Light in daily life and what light means for an astronomer (exhibition). 2/ Light in all its states or how to extract information from the heavenly bodies: exploration using telescopes, space probes, spectrometry and imagery. Measuring and modelling using light (physical parameters, distances, etc.) Fabio Barblan is "an external scientific collaborator" and member of the photometry, stellar variability and GAIA group at the Observatoire de Genève. Observatoire de Genève Friday 14 October from 8:30 p.m. to 10:00 p.m. » Suitable for all – Admission free - Lecture in French For further information: +33 (0)4 50 41 96 80

  9. Tooth extraction

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007630.htm Tooth extraction To use the sharing features on this page, please enable JavaScript. A tooth extraction is a procedure to remove a tooth from ...

  10. Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    Light Robotics - Structure-Mediated Nanobiophotonics covers the latest means of sculpting of both light and matter for achieving bioprobing and manipulation at the smallest scales. The synergy between photonics, nanotechnology and biotechnology spans the rapidly growing field of nanobiophotonics...

  11. Twisted light

    CSIR Research Space (South Africa)

    Forbes, A

    2010-12-01

    Full Text Available Research at the Mathematical Optics Group uses "twisted" light to study new quatum-based information security systems. In order to understand the structure of "twisted" light, it is useful to start with an ordinary light beam with zero twist, namely...

  12. Public lighting.

    NARCIS (Netherlands)

    2011-01-01

    Visual perception is very important for road users and in the dark it can be facilitated by public lighting. Public lighting has a mostly positive road safety effect. Installing public lighting on roads that were previously unlit generally results in fewer and less serious crashes. This effect seems

  13. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    to be static, and no longer acts as a kind of spatial constancy maintaining stability and order? Moreover, what new potentials open in lighting design? This book is one of four books that is published in connection with the research project entitled LED Lighting; Interdisciplinary LED Lighting Research...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... the investigations of lighting scenarios carried out in two test installations: White Cube and White Box. The test installations are discussed as large-scale experiential instruments. In these test installations we examine what could potentially occur when light using LED technology is integrated and distributed...

  14. Adaptive Lighting

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin; Kongshaug, Jesper

    2015-01-01

    Adaptive Lighting Adaptive lighting is based on a partial automation of the possibilities to adjust the colour tone and brightness levels of light in order to adapt to people’s needs and desires. IT support is key to the technical developments that afford adaptive control systems. The possibilities...... offered by adaptive lighting control are created by the ways that the system components, the network and data flow can be coordinated through software so that the dynamic variations are controlled in ways that meaningfully adapt according to people’s situations and design intentions. This book discusses...... differently into an architectural body. We also examine what might occur when light is dynamic and able to change colour, intensity and direction, and when it is adaptive and can be brought into interaction with its surroundings. In short, what happens to an architectural space when artificial lighting ceases...

  15. Let there be no light: the effect of bedside light on sleep quality and background electroencephalographic rhythms

    OpenAIRE

    Cho, Jounhong Ryan; Joo, Eun Yeon; Koo, Dae Lim; Hong, Seung Bong

    2013-01-01

    Objectives: Artificial lighting has been beneficial to society, but unnecessary light exposure at night may cause various health problems. We aimed to investigate how whole-night bedside light can affect sleep quality and brain activity. Patients and methods: Ten healthy sleepers underwent two polysomnography (PSG) sessions, one with the lights off and one with the lights on. PSG variables related to sleep quality were extracted and compared between lights-off and lights-on sleep. Sp...

  16. Electromembrane extraction

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Chen, Zhiliang; Gjelstad, Astrid

    2017-01-01

    Electromembrane extraction (EME) was inspired by solid-phase microextraction and developed from hollow fiber liquid-phase microextraction in 2006 by applying an electric field over the supported liquid membrane (SLM). EME provides rapid extraction, efficient sample clean-up and selectivity based...

  17. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

    2012-01-01

    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...... extraction in a prospective observational study. Setting. Rigshospitalet, University Hospital of Copenhagen. Population. For development an obstetric expert from each labor ward in Denmark (28 departments) were invited to participate. For validation nine first-year residents and ten chief physicians...... with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...

  18. Vacuum extraction

    DEFF Research Database (Denmark)

    Maagaard, Mathilde; Oestergaard, Jeanett; Johansen, Marianne

    2012-01-01

    Objectives. To develop and validate an Objective Structured Assessment of Technical Skills (OSATS) scale for vacuum extraction. Design. Two part study design: Primarily, development of a procedure-specific checklist for vacuum extraction. Hereafter, validationof the developed OSATS scale for vacuum...... extraction in a prospective observational study. Setting. Rigshospitalet, University Hospital of Copenhagen. Population. For development an obstetric expert from each labor ward in Denmark (28 departments) were invited to participate. For validation nine first-year residents and ten chief physicians...... with daily work in the obstetric field were tested. Methods. The Delphi method was used for development of the scale. In a simulated vacuum extraction scenario first-year residents and obstetric chief physicians were rated using the developed OSATS scale for vacuum extraction to test construct validity...

  19. Baking Light

    DEFF Research Database (Denmark)

    Tamke, Martin

    2005-01-01

    decisions. Display quality, comfortable navigation and realistic illumination are crucial ingredients here. Light is one of the principal elements in architectural design, so design reviews must enable the architect to judge the quality of his design in this respect. Realistic light simulations, e.g. via...... radiosity algorithms, are no longer the domain of high-end graphic workstations. Today’s off-the-shelf hardware and 3D-software provide the architect with high-quality tools to simulate physically correct light distributions. But the quality and impression of light is hard to judge by looking at still...... practical experiences with global-light-simulations. We share results which we think are helpful to others, and we highlight areas where further research is necessary....

  20. Lightness functions

    DEFF Research Database (Denmark)

    Campi, Stefano; Gardner, Richard; Gronchi, Paolo;

    2012-01-01

    Variants of the brightness function of a convex body K in n-dimensional Euclidean are investigated. The Lambertian lightness function L(K; v , w ) gives the total reflected light resulting from illumination by a light source at infinity in the direction w that is visible when looking...... in the direction v . The partial brightness function R( K ; v , w ) gives the area of the projection orthogonal to v of the portion of the surface of K that is both illuminated by a light source from the direction w and visible when looking in the direction v . A class of functions called lightness functions...... is introduced that includes L(K;.) and R(K;.) as special cases. Much of the theory of the brightness function like uniqueness, stability, and the existence and properties of convex bodies of maximal and minimal volume with finitely many function values equal to those of a given convex body, is extended...

  1. Baking Light

    DEFF Research Database (Denmark)

    Tamke, Martin

    2005-01-01

    decisions. Display quality, comfortable navigation and realistic illumination are crucial ingredients here. Light is one of the principal elements in architectural design, so design reviews must enable the architect to judge the quality of his design in this respect. Realistic light simulations, e.g. via...... radiosity algorithms, are no longer the domain of high-end graphic workstations. Today’s off-the-shelf hardware and 3D-software provide the architect with high-quality tools to simulate physically correct light distributions. But the quality and impression of light is hard to judge by looking at still...... practical experiences with global-light-simulations. We share results which we think are helpful to others, and we highlight areas where further research is necessary....

  2. Light Conduction Capability of Different Light-Transmitting FRC Posts

    Directory of Open Access Journals (Sweden)

    Saied Mostafa Moazzami

    2013-01-01

    Full Text Available Introduction: Application of light transmitting posts to restore greatly damaged endodontically treated teeth has been increased. It is suspected that light intensity decreases as it passes throughout different materials. This can reduce the degree of conversion required for adequate bond strength throughout the length of these posts. The objective of this study was to evaluate the amount of light intensity reduction after passing through different depths of FRC posts. Methods: Four groups of five extracted human central incisors were prepared to cement four types of FRC posts with Panavia F 2 resin cement. The apical end of the posts were exposed by sectioning with a diamond disk and then polished. The light intensity measurement was performed using a micro-voltmeter in 8 points or depths with 2mm intervals beginning from the apical depth of 16mm up to a coronal depth of 6mm. Two different output light intensities [HIP (High Intensity Program and LOP (Low Intensity Program] were evaluated. Results: Statistical analysis showed significant differences in light intensity at various depths between 6 and 16mm in all groups. These reductions were linear in all specimens; however, the rate of reduction was dissimilar among different FRC posts. HIP and LOP light exposure modes had not the same rate of light reduction. Conclusion: Light intensity decreased dramatically after passing through different depths of FRC posts. None of the posts had sufficient enough light transmission for satisfactory polymerization at the apical and middle levels.

  3. Light Conduction Capability of Different Light-Transmitting

    Directory of Open Access Journals (Sweden)

    Saied Mostafa Moazzami

    2012-09-01

    Full Text Available Introduction: Application of light transmitting posts to restore greatly damaged endodontically treated teeth has been increased. It is suspected that light intensity decreases as it passes throughout different materials. This can reduce the degree of conversion required for adequate bond strength throughout the length of these posts. The objective of this study was to evaluate the amount of light intensity reduction after passing through different depths of FRC posts. Methods: Four groups of five extracted human central incisors were prepared to cement four types of FRC posts with Panavia F 2 resin cement. The apical end of the posts were exposed by sectioning with a diamond disk and then polished. The light intensity measurement was performed using a micro-voltmeter in 8 points or depths with 2mm intervals beginning from the apical depth of 16mm up to a coronal depth of 6mm. Two different output light intensities [HIP (High Intensity Program and LOP (Low Intensity Program] were evaluated. Results: Statistical analysis showed significant differences in light intensity at various depths between 6 and 16mm in all groups. These reductions were linear in all specimens; however, the rate of reduction was dissimilar among different FRC posts. HIP and LOP light exposure modes had not the same rate of light reduction. Conclusion: Light intensity decreased dramatically after passing through different depths of FRC posts. None of the posts had sufficient enough light transmission for satisfactory polymerization at the apical and middle levels.

  4. Shaping light

    CSIR Research Space (South Africa)

    Forbes, A

    2010-01-01

    Full Text Available mirrors, a gain medium, and a means to excite the gain medium. Quest 6(3) 2010 11 The excited gain medium has what is called a population inversion (it contains more atoms in an excited state than at a lower energy state). Laser light... of what is known as coherence, a measure of how ?in-step? the emitted photons of light are. Coherent light can be made to interfere with itself, in a way that is similar to the way in which ripples on a pond interact. As a result, it is possible...

  5. SCHOOL LIGHTING APPLICATION DATA. EXCERPTS FROM THE IES LIGHTING HANDBOOK, 3RD EDITION.

    Science.gov (United States)

    Illuminating Engineering Society, New York, NY.

    THIS PUBLICATION REGARDING SCHOOL LIGHTING WAS PREPARED AS A USEFUL ADDITION TO THE AMERICAN STANDARD GUIDE FOR SCHOOL LIGHTING. THE MATERIAL HAS BEEN EXTRACTED FROM THE IES LIGHTING HANDBOOK TO INCLUDE A MORE DETAILED TREATMENT OF SUBJECTS TO WHICH THE DESIGNER MUST GIVE IMPORTANT CONSIDERATION. THERE IS A MORE EXTENSIVE TREATMENT OF REFLECTED…

  6. Protein Extractability

    African Journals Online (AJOL)

    human nutrition, particularly in developing ... studied the effect of NaCl on the extractability of ... significant influence on the functional properties ..... Malaka, S. L. O. and Amund, O. O. Studies on the Life Cycle and Morphometrics of Honeybees,.

  7. Bevalac extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kalnins, J.G.; Krebs, G.; Tekawa, M.; Cowles, D.; Byrne, T.

    1992-02-01

    This report will describe some of the general features of the Bevatron extraction system, primarily the dependence of the beam parameters and extraction magnet currents on the Bevalac field. The extraction magnets considered are: PFW, XPl, XP2, XS1, XS2, XM1, XM2, XM3, XQ3A and X03B. This study is based on 84 past tunes (from 1987 to the present) of various ions (p,He,O,Ne,Si,S,Ar,Ca,Ti,Fe,Nb,La,Au and U), for Bevalac fields from 1.749 to 12.575 kG, where all tunes included a complete set of beam line wire chamber pictures. The circulating beam intensity inside the Bevalac is measured with Beam Induction Electrodes (BIE) in the South Tangent Tank. The extracted beam intensity is usually measured with the Secondary Emission Monitor (SEM) in the F1-Box. For most of the tunes the extraction efficiency, as given by the SEM/BIE ratio, was not recorded in the MCR Log Book, but plotting the available Log Book data as a function of the Bevalac field, see Fig.9, we find that the extraction efficiency is typically between 30->60% with feedback spill.

  8. Combination Light

    Science.gov (United States)

    1990-01-01

    The Rayovac TANDEM is an advanced technology combination work light and general purpose flashlight that incorporates several NASA technologies. The TANDEM functions as two lights in one. It features a long range spotlight and wide angle floodlight; simple one-hand electrical switching changes the beam from spot to flood. TANDEM developers made particular use of NASA's extensive research in ergonomics in the TANDEM's angled handle, convenient shape and different orientations. The shatterproof, water resistant plastic casing also draws on NASA technology, as does the shape and beam distance of the square diffused flood. TANDEM's heavy duty magnet that permits the light to be affixed to any metal object borrows from NASA research on rare earth magnets that combine strong magnetic capability with low cost. Developers used a NASA-developed ultrasonic welding technique in the light's interior.

  9. Black ginseng extract ameliorates hypercholesterolemia in rats

    Directory of Open Access Journals (Sweden)

    Evelyn Saba

    2016-04-01

    Conclusion: Administration of BG extracts to Sprague Dawley rats fed with high-cholesterol diet ameliorated hypercholesterolemia, which was mediated via modulation of cholesterol-metabolizing marker genes. This data throw a light on BG's cardioprotective effects.

  10. Intermediate-energy light sources

    CERN Document Server

    Corbett, W

    2003-01-01

    Increasingly, atomic scale information underlies scientific and technological progress in disciplines ranging from pharmaceutical development to materials synthesis to environmental remediation. While a variety of research tools are used to provide atomic scale information, synchrotron radiation has proved invaluable in this quest. The rapid growth of soft- and hard X-ray synchrotron light sources stands as stark testimony to the importance and utility of synchrotron radiation. Starting from just a handful of synchrotron light sources in the early 1970s, this burgeoning field now includes over 70 proposed, in-construction, or operating facilities in 23 countries on five continents. Along the way, synchrotron light facilities have evolved from small laboratories extracting light parasitically from storage rings designed for high-energy physics research to large, dedicated sources using the latest technology to produce extraordinarily bright photon beams. The basic layout of a multi-GeV storage ring light sourc...

  11. Lighting Computer Programs in Lighting Technology

    OpenAIRE

    Ekren, Nazmi; Dursun, Bahtiyar; Ercan AYKUT

    2008-01-01

    It is well known that the computer in lighting technology is a vital component for lighting designers. Lighting computer programs are preferred in preparing architectural projects in lighting techniques, especially in lighting calculations. Lighting computer programs, which arise with the aim of helping lighting designers, gain more interest day by day. The most important property of lighting computer programs is the ability to enable the simulation of lighting projects without requiring any ...

  12. Detection of foodborne bacterial pathogens from individual filth flies.

    Science.gov (United States)

    Pava-Ripoll, Monica; Pearson, Rachel E G; Miller, Amy K; Ziobro, George C

    2015-02-13

    There is unanimous consensus that insects are important vectors of foodborne pathogens. However, linking insects as vectors of the pathogen causing a particular foodborne illness outbreak has been challenging. This is because insects are not being aseptically collected as part of an environmental sampling program during foodborne outbreak investigations and because there is not a standardized method to detect foodborne bacteria from individual insects. To take a step towards solving this problem, we adapted a protocol from a commercially available PCR-based system that detects foodborne pathogens from food and environmental samples, to detect foodborne pathogens from individual flies.Using this standardized protocol, we surveyed 100 wild-caught flies for the presence of Cronobacter spp., Salmonella enterica, and Listeria monocytogenes and demonstrated that it was possible to detect and further isolate these pathogens from the body surface and the alimentary canal of a single fly. Twenty-two percent of the alimentary canals and 8% of the body surfaces from collected wild flies were positive for at least one of the three foodborne pathogens. The prevalence of Cronobacter spp. on either body part of the flies was statistically higher (19%) than the prevalence of S. enterica (7%) and L.monocytogenes (4%). No false positives were observed when detecting S. enterica and L. monocytogenes using this PCR-based system because pure bacterial cultures were obtained from all PCR-positive results. However, pure Cronobacter colonies were not obtained from about 50% of PCR-positive samples, suggesting that the PCR-based detection system for this pathogen cross-reacts with other Enterobacteriaceae present among the highly complex microbiota carried by wild flies. The standardized protocol presented here will allow laboratories to detect bacterial foodborne pathogens from aseptically collected insects, thereby giving public health officials another line of evidence to find out how the food was contaminated when performing foodborne outbreak investigations.

  13. Lighting and public health.

    NARCIS (Netherlands)

    Ierland, J. van & Schreuder, D.A.

    1969-01-01

    The following topics; are discussed with respect to public health: - the effect of visible and ultraviolet radiation upon man. - vision with respect to lighting. interior lighting. - artificial lighting of work environments. - day light and windows. - recommendations for lighting. public lighting. -

  14. Lighting Design

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Mullins, Michael

    2014-01-01

    Light as a multi-dimensional design element has fundamental importance for a sustainable environment. The paper discusses the need for an integration of scientific, technical and creative approaches to light and presents theory, methods and applications toward fulfilling this need. A theory...... of design developed from three experiments show how distinct qualitative and quantitative criteria in different disciplinary traditions can be integrated successfully, despite disparate technical/scientific, social scientific and art/humanities backgrounds. The model is applied to a pedagogical curriculum...

  15. Lighting Design

    DEFF Research Database (Denmark)

    Hansen, Ellen Kathrine; Mullins, Michael

    2014-01-01

    of design developed from three experiments show how distinct qualitative and quantitative criteria in different disciplinary traditions can be integrated successfully, despite disparate technical/scientific, social scientific and art/humanities backgrounds. The model is applied to a pedagogical curriculum......Light as a multi-dimensional design element has fundamental importance for a sustainable environment. The paper discusses the need for an integration of scientific, technical and creative approaches to light and presents theory, methods and applications toward fulfilling this need. A theory...

  16. Calculus light

    CERN Document Server

    Friedman, Menahem

    2011-01-01

    Another Calculus book? As long as students find calculus scary, the failure rate in mathematics is higher than in all other subjects, and as long as most people mistakenly believe that only geniuses can learn and understand mathematics, there will always be room for a new book of Calculus. We call it Calculus Light. This book is designed for a one semester course in ""light"" calculus -- mostly single variable, meant to be used by undergraduate students without a wide mathematical background and who do not major in mathematics but study subjects such as engineering, biology or management infor

  17. Information extraction

    NARCIS (Netherlands)

    Zhang, Lei; Hoede, C.

    2002-01-01

    In this paper we present a new approach to extract relevant information by knowledge graphs from natural language text. We give a multiple level model based on knowledge graphs for describing template information, and investigate the concept of partial structural parsing. Moreover, we point out that

  18. EXPANDING EXTRACTIONS

    NARCIS (Netherlands)

    Dietzenbacher, Erik; Lahr, Michael L.

    2013-01-01

    In this paper, we generalize hypothetical extraction techniques. We suggest that the effect of certain economic phenomena can be measured by removing them from an input-output (I-O) table and by rebalancing the set of I-O accounts. The difference between the two sets of accounts yields the phenomeno

  19. Green lights

    DEFF Research Database (Denmark)

    Fisker, Peter Kielberg

    This study investigates the effect of drought on economic activity globally using remote sensing data. In particular, predicted variation in greenness is correlated with changes in the density of artificial light observed at night on a grid of 0.25 degree latitude-longitude pixels. I define drought...

  20. Light-by-light scattering sum rules in light of new data

    CERN Document Server

    Danilkin, Igor

    2016-01-01

    We evaluate the light-quark meson contributions to three exact light-by-light scattering sum rules in light of new data by the Belle Collaboration, which recently has extracted the transition form factors of the tensor meson $f_2(1270)$ as well as of the scalar meson $f_0(980)$. We confirm a previous finding that the $\\eta, \\eta^\\prime$ and helicity-2 $f_2(1270)$ contributions saturate one of these sum rules up to photon virtualities up to around 1 GeV$^2$. At larger virtualities, our sum rule analysis shows an important contribution of the $f_2(1565)$ meson and provides a first empirical extraction of its helicity-2 transition form factor. Two further sum rules allow us to predict the helicity-0 and helicity-1 transition form factors of the $f_2(1270)$ meson. Furthermore, our analysis also provides an update for the scalar and tensor meson hadronic light-by-light contributions to the muon's anomalous magnetic moment.

  1. Light Sources and Lighting Circuits

    Science.gov (United States)

    Honda, Hisashi; Suwa, Takumi; Yasuda, Takeo; Ohtani, Yoshihiko; Maehara, Akiyoshi; Okada, Atsunori; Komatsu, Naoki; Mannami, Tomoaki

    According to the Machinery Statistics of the Ministry of Economy, Trade and Industry, the production of incandescent lamps in Japan in 2007 was 990 million units (90.0% of the previous year's total), in which the production of incandescent lamps for general lighting was 110 million units (90.0% of the previous year's total) and of tungsten-halogen lamps was 44 million units (96.6% of the previous year's total). The production of fluorescent lamps was 927 million units (93.9% of the previous year's total), in which general fluorescent lamps, excluding those for LCD back lighting, was 320 million units (87.2% of the previous year's total). Also, the production of HID lamps was 10 million units (101.5% of the previous year's total). On the other hand, when the numbers of sales are compared with the sales of the previous year, incandescent lamps for general use was 99.8%, tungsten-halogen lamps was 96.9%, fluorescent lamps was 95.9%, and HID lamps was 98.9%. Self-ballasted fluorescent lamps alone showed an increase in sales as strong as 29 million units, or 121.7% of the previous year's sales. It is considered that the switchover of incandescent lamps to HID lamps was promoted for energy conservation and carbon dioxide reduction with the problem of global warming in the background. In regard to exhibitions, Lighting Fair 2007 was held in Tokyo in March, and LIGHTFAIR INTERNATIONAL 2007 was held in New York in May. Regarding academic conferences, LS:11 (the 11th International Symposium on the Science & Technology of Light Sources) was held in Shanghai in May, and the First International Conference on White LEDs and Solid State Lighting was held in Tokyo in November. Both conferences suggested that there are strong needs and concerns now about energy conservation, saving natural resources, and restrictions of hazardous materials. In regard to incandescent lamps, the development of products aiming at higher efficacy, electric power savings, and longer life was advanced by

  2. EDITORIAL: Controlling light with light

    Science.gov (United States)

    Hesselink, Lambertus; Feinberg, Jack; Roosen, Gerald

    2008-11-01

    The field of photorefractive physics and optics is mature and, although there is no significant commercial activity using photorefractive media, researchers in the field have had an extraordinary impact on many related areas of research and development. For example, in the late 1990s many of the telecom innovations and products were based on the interaction between light and matter. Examples include optical switches, filters, gratings, routers and light sources. The theory of multiple interacting beams of light inside a photosensitive medium, many of which were developed or further explored in photorefractive media, has found application in medicine, engineering, communication systems, displays and other photonics devices. On the occasions of the 30th anniversary of the theory of coupled wave analysis and the 10th anniversary of the meetings on Photorefractive Effects and Devices, it seemed appropriate to the meeting organizers of PR'07 to broaden the scope to include other related fields. The name of the meeting was changed to Controlling Light with Light: Photorefractive Effects, Photosensitivity, Fiber Gratings, Photonic Materials and More to attract a larger audience than traditionally would attend the more narrowly focused photorefractive meeting. To further disseminate the results of the 2007 meeting, Gerald Roosen proposed a special publication of original full research articles arising from key presentations at the meeting. The selection of papers in this Cluster Issue of Journal of Physics D: Applied Physics is the result of that initiative. We would like to thank all the authors for their contributions, the committee members for their valuable insight and efforts in helping to organize the meeting, and the Optical Society of America for their professional assistance throughout the preparation period of the meeting as well as during the three beautiful days in Lake Tahoe, CA.

  3. Binding of antibodies to the extractable nuclear antigens SS-A/Ro and SS-B/La is induced on the surface of human keratinocytes by ultraviolet light (UVL): Implications for the pathogenesis of photosensitive cutaneous lupus

    Energy Technology Data Exchange (ETDEWEB)

    Furukawa, F.; Kashihara-Sawami, M.; Lyons, M.B.; Norris, D.A. (Univ. of Colorado School of Medicine, Denver (USA))

    1990-01-01

    Autoantibodies to the non-histone nucleoprotein antigens SS-A/Ro, SS-B/La, and RNP are highly associated with photosensitive cutaneous lupus erythematosus (LE). In order to better understand the potential mechanisms of ultraviolet (UV) light on photosensitivity in patients with cutaneous LE, we designed immunopathologic in vitro and in vivo experiments to evaluate the effects of UV on the binding of such autoantibodies to the surface of human keratinocytes, one major target of immunologic damage in photosensitive LE. Short-term 2% paraformaldehyde fixation of suspensions of cultured human keratinocytes previously incubated with monospecific antiserum probes enabled the detection of ENA expression on the cell surface by flow-cytometry analysis. UVB light (280-320 nm) induced the binding of monospecific antibody probes for SS-A/Ro and SS-B/La on keratinocytes in a dose-dependent pattern with maximal induction observed at the dose of 200 mJ/cm2 UVB. Binding of SS-A/Ro, SS-B/La, and RNP antibody was augmented strongly, but binding of anti-Sm was very weak. In contrast, UVA (320-400 nm) light had no effect on the induction of binding of these antibody probes. Identical results were seen by standard immunofluorescence techniques. Hydroxyurea-treated keratinocytes showed similar induction of those antigens by UVB irradiation, which suggested that ENA expression on cultured keratinocytes by UVB were cell-cycle independent. Tunicamycin, an inhibitor of glycosylation of proteins, reduced UVB light effect on the SS-A/Ro and SS-B/La antigen's expression. These in vitro FACS analyses revealed that ENA augmentation on the keratinocyte cell surface was dose dependent, UVB dependent, glycosylation dependent, and cell-cycle independent. In vivo ENA augmentation on the keratinocyte surface was examined in suction blister epidermal roofs.

  4. Handbook of industrial lighting

    CERN Document Server

    Lyons, Stanley L

    2013-01-01

    Handbook of Industrial Lighting is a practical guide on the specification, design, installation, operation, and maintenance of lighting in industrial premises. Coverage of the book includes the importance of good localized lighting; the different lighting schemes; lighting for difficult visual tasks; lighting in consideration to safety; and emergency lighting. The book also includes the practical, thermal, ventilation, and energy considerations; lighting in different environments; maintenance of lighting installations; and the cost benefits of efficient lighting. Appendices include useful info

  5. Light fantastic

    Science.gov (United States)

    2010-05-01

    The laser has become so ubiquitous that it would be impossible to acknowledge everyone who has played a role in its success. As Roy Glauber said at the 2005 Nobel-prize banquet, when it comes to lasers, "many hands make light work". And he should know: the prize Glauber shared with fellow optics pioneers John Hall and Theodore Hänsch is one of more than 10 Nobels awarded (so far!) for laser-related research. This timeline marking 50 years of the laser contains Physics World's pick of events from laser history, including prizes (gold text), applications (green) and "firsts" (blue).

  6. Green lights

    DEFF Research Database (Denmark)

    Fisker, Peter Kielberg

    as greenness estimated by lagged variation in monthly rainfall and temperature. This definition of drought performs well in identifying self-reported drought events since 2000 compared with measures of drought that do not take greenness into account, and the subsequent analysis indicates that predicted...... variation in greenness is positively associated with year-on-year changes in luminosity: If a unit of observation experiences a predicted variation in greenness that lies 1 standard deviation below the global mean, on average 1.5 - 2.5 light pixels out of 900 are extinguished that year. Finally, an attempt...... is made to estimate the global cost of drought....

  7. Preliminary studies of inhibitions in Aspergillus flavus with extracts of ...

    African Journals Online (AJOL)

    Administrator

    of lichens on the growth of lower Phycomycetes and. Neurospora ... have indicated the possible use of plant as well as lichen extracts in the control of plant diseases. The extraction, ... under light microscope (*400 objective) for the emergence of germ tube. .... artificial fungicide develop, this study has shown that extracts of ...

  8. Light-induced pH change and its application to solid phase extraction of trace heavy metals by high-magnetization Fe3O4@SiO2@TiO2 nanoparticles followed by inductively coupled plasma mass spectrometry detection.

    Science.gov (United States)

    Zhang, Nan; Peng, Hanyong; Hu, Bin

    2012-05-30

    We report here the preparation of high-magnetization Fe(3)O(4)@SiO(2)@TiO(2) nanoparticles for solid phase extraction of trace amounts of Cd(II), Cr(III), Mn(II) and Cu(II) from environmental waters. The prepared nanoparticles were characterized by scanning electron micrograph (SEM) and transmission electron microscopy (TEM). The high-magnetization nanoparticles carrying the target metals could be easily and fast separated from the aqueous solution simply by applying an external magnetic field while no filtration or centrifugation was necessary. A light-induced hydroxide ion emitter, molecular malachite green carbinol base (MGCB) was applied to adjust pH value of solution for quantitative adsorption instead of the conventional used buffer. In the presence of UV light, MGCB gives out OH(-) ions, and this leads to an increase in the pH value without the aid of buffer solution. Using high-magnetization Fe(3)O(4)@SiO(2)@TiO(2) nanoparticles as the extraction material and the light-induced MGCB for pH adjustment, we developed an efficient and convenient two-step method for separation/preconcentration trace amounts of Cd(II), Cr(III), Mn(II) and Cu(II) in environmental water samples followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. The parameters affecting the extraction such as MGCB concentration, exposal time, sample volume, eluent condition, and interfering ions have been investigated in detail. Under the optimized conditions, the limits of detection for Cd(II), Cr(III), Mn(II) and Cu(II) were 4.0, 2.6, 1.6 and 2.3 ng L(-1), respectively, and the relative standard deviations (RSDs, c=1 μg L(-1), n=7) were 3.6%, 4.5%, 4.0 and 4.1%, respectively. The proposed method has been validated using certified reference materials, and it has been successfully applied in the determination of trace Cd(II), Cr(III), Mn(II) and Cu(II) in environmental water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. How to distinguish elastically scattered light from Stokes shifted light for solid-state lighting?

    CERN Document Server

    Meretska, M; Thyrrestrup, H; Mosk, A P; IJzerman, W L; Vos, W L

    2015-01-01

    We have studied the transport of light through phosphor diffuser plates that are used in commercial solid-state lighting modules (Fortimo). These polymer plates contain $\\mathrm{YAG:Ce}^{+3}$ phosphor particles that elastically scatter light and Stokes shifts it in the visible wavelength range (400-700 nm). We excite the phosphor with a narrowband light source, and measure spectra of the outgoing light. The Stokes shifted light is separated from the elastically scattered light in the measured spectra and using this technique we isolate the elastic transmission of the plates. This result allows us to extract the transport mean free path $l_{\\mathrm{tr}}$ over the full wavelength range by employing diffusion theory. Simultaneously, we determine the absorption mean free path $l_{\\mathrm{abs}}$ in the wavelength range 400 to 530 nm where $\\mathrm{YAG:Ce}^{+3}$ absorbs. The diffuse absorption $\\mu_{\\mathrm{a}} =\\frac{1}{l_{\\mathrm{abs}}}$ spectrum is qualitative similar to the absorption coefficient of $\\mathrm{YA...

  10. Interactive directional subsurface scattering and transport of emergent light

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Frisvad, Jeppe Revall; Mosegaard, Jesper;

    2016-01-01

    -based analytical models for subsurface scattering but also directional models. In addition, our method enables easy extraction of virtual point lights for transporting emergent light to the rest of the scene. Our method requires neither preprocessing nor texture parameterization of the translucent objects...... is the first to include interactive transport of emergent light from deformable translucent objects....

  11. Calibration for 3D Structured Light Measurement

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A calibration procedure was developed for three-dimensional(3D) binocular structured light measurement systems. In virtue of a specially designed pattern, matching points in stereo images are extracted. And then sufficient 3D space points are obtained through pairs of images with the intrinsic and extrinsic parameters of each camera estimated prior and consequently some lights are calibrated by means of multi point fitting. Finally, a mathematical model is applied to interpolate and approximate all dynamic scanning lights based on geometry. The process of calibration method is successfully used in the binocular 3D measurement system based on structured lights and the 3D reconstruction results are satisfying.

  12. Light Meson Distribution Amplitudes

    CERN Document Server

    Arthur, R.; Brommel, D.; Donnellan, M.A.; Flynn, J.M.; Juttner, A.; de Lima, H.Pedroso; Rae, T.D.; Sachrajda, C.T.; Samways, B.

    2010-01-01

    We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.

  13. Light-light and heavy-light mesons in the model of QCD string with quarks at the ends

    CERN Document Server

    Nefediev, A V

    2002-01-01

    The variational einbein field method is applied to the model of the QCD string with quarks at the ends for the case of light-light and heavy-light mesons. Special attention is payed to the proper string dynamics. The correct string slope of the Regge trajectories is reproduced for light-light states which comes out from the picture of rotating string. Masses of several low-lying orbitally and radially excited states in the D, D_s, B, and B_s meson spectra are calculated and a good agreement with the experimental data as well as with recent lattice calculations is found. The role of the string correction to the interquark interaction is discussed at the example of the identification of D*'(2637) state recently claimed by DELPHI Collaboration. For the heavy-light mesons the standard constants used in Heavy Quark Effective Theory are extracted and compared to the results of other approaches.

  14. EDITORIAL: LED light sources (light for the future) LED light sources (light for the future)

    Science.gov (United States)

    Grandjean, N.

    2010-09-01

    comprehensive review of the different localization mechanisms and their implication for internal quantum efficiency (IQE) is proposed by Oliver and co-workers from Cambridge University. When discussing IQE in InGaN-based LEDs, the efficiency droop at high-current injection always emerges, which is a major concern for the future of SSL technology. Here, a collaborative work between Samsung and the Gwangju Institute of Science and Technology (Korea) proves that a specific design of the active region can limit this detrimental effect. Once the issue of the IQE is solved, one still has to let the photons out of the chip. Matioli and Weisbuch from the University of California at Santa Barbara introduce the use of photonic crystals (PhCs) to improve light extraction efficiency. They describe different approaches to overcoming the main limitation of LEDs when implementing surface PhCs. The technology of SSL, and in particular of colour rendering, is tackled by Zukauskas et al who studied in detail different white light sources. They show that extreme colour-fidelity indices need to cover the entire spectrum, with a broad-band at 530-610 nm and a component beyond 610 nm. Then, the reliability of GaN-based LEDs is discussed in the paper of Meneghesso and co-workers. The authors consider the most important physical mechanisms that are (i) the degradation of the active layer of LEDs, (ii) the degradation of the package/phosphor system, (iii) the failure of GaN-based LEDs against electrostatic discharge. Finally, GaN LEDs on silicon developed in the group of Egawa at the Nagoya Institute of Technology are presented. This technology could allow a significant decrease in the fabrication cost of white LEDs.

  15. Separation of digoxin by luiquid-luiquid extraction from extracts of foxglove secondary glycosides

    Directory of Open Access Journals (Sweden)

    Novković Vesna V.

    2014-01-01

    Full Text Available The present study deals with the extraction of digoxin (Dgx from chloroform and trichloroethylene extracts of the secondary glycosides of fermented foxglove (Digitalis lanata Ehrh. foliage by liquid-liquid extraction. The extraction degree (ED of Dgx achieved by maceration and percolation using 10% vol. aqueous ethanol solutions were higher than 95%. Using trichlorethylene and chloroform, the ED of Dgx of about 100% and 96%, respectively from the liquid ethanolic extracts (macerate or percolate were achieved by the four-cycle extraction. Fifteen separating funnels were employed for the liquid-liquid extraction. Three different four-component two-phase systems (ethanol:water - chloroform:ethyl acetate, ethanol:water - chloroform:trichloroethylene and ethanol:water - trichloroethylene:ethyl acetate were tested as an extracting solvent to get the final product having more than 98% of Dgx. The initial amount of the chloroform or trichloroethylene extract in the light phase was varied between 5 and 25 g/L, while the volume ratio of light and heavy phases was in the range of 1:1 to 1:2. The best Dgx yield of 98% was achieved with the system ethanol:water - chloroform:trichloroethylene 35:15:20:30 at the volume ratio of the phases of 1:1.1 and at the initial amount of the extract of 15 g/L. Purity of the separated digoxin was 99.8 %. [Projekat Ministarstva nauke Republike Srbije, br. TR-34012

  16. Apparatus for hydrocarbon extraction

    Science.gov (United States)

    Bohnert, George W.; Verhulst, Galen G.

    2013-03-19

    Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

  17. Light addressable gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Waqas

    2011-07-01

    The main objective carried out in this dissertation was to fabricate Light Amplified Potentiometric sensors (LAPS) based upon the semiconductor nanoparticles (quantum dots) instead of its bulk form. Quantum dots (QDs) were opted for this device fabrication because of their superior fluorescent, electric and catalytic properties. Also in comparison to their bulk counterparts they will make device small, light weighted and power consumption is much lower. QDs were immobilized on a Au substrate via 1,4 benzene dithiol (BDT) molecule. Initially a self-assembled monolayer (SAM) of BDT was established on Au substrate. Because of SAM, the conductivity of Au substrate decreased dramatically. Furthermore QDs were anchored with the help of BDT molecule on Au substrate. When QDs immobilized on Au substrate (QD/Au) via BDT molecule were irradiated with UV-visible light, electron-hole pairs were generated in QDs. The surface defect states in QDs trapped the excited electrons and long lived electron-hole pairs were formed. By the application of an appropriate bias potential on Au substrate the electrons could be supplied or extracted from the QDs via tunneling through BDT. Thus a cathodic or anodic current could be observed depending upon bias potential under illumination. However without light illumination the QD/Au electrode remained an insulator. To improve the device different modifications were made, including different substrates (Au evaporated on glass, Au evaporated on mica sheets and Au sputtered on SiO{sub 2}/Si) and different dithiol molecules (capped and uncapped biphenyl 4,4' dithiol and capped and uncapped 4,4' dimercaptostilbenes) were tried. Also different QD immobilization techniques (normal incubation, spin coating, layer by layer assembly (LbL) of polyelectrolytes and heat immobilization) were employed. This device was able to detect electrochemically different analytes depending upon the QDs incorporated. For example CdS QDs were able to detect 4

  18. Residential lighting design

    CERN Document Server

    Steffen, Marcus

    2014-01-01

    Good lighting is essential to a building. An effective design is not just about introducing light into a space, but rather an appreciation of how the space will be used. A good lighting design is so intertwined with the building that it is only noticed in its absence. This book introduces the tools of the lighting designer and explains how to produce a lighting design for a home. Looking at the nature of light and introducing different lamps and light fittings available, it explains the basics of lighting design and how to provide atmosphere through the play of light and shadow. It gives room-

  19. Method for analyzing solvent extracted sponge core

    Energy Technology Data Exchange (ETDEWEB)

    Ellington, W.E.; Calkin, C.L.

    1988-11-22

    For use in solvent extracted sponge core measurements of the oil saturation of earth formations, a method is described for quantifying the volume of oil in the fluids resulting from such extraction. The method consists of: (a) separating the solvent/oil mixture from the water in the extracted fluids, (b) distilling at least a portion of the solvent from the solvent/oil mixture substantially without co-distillation or loss of the light hydrocarbons in the mixture, (c) determining the volume contribution of the solvent remaining in the mixture, and (d) determining the volume of oil removed from the sponge by substracting the determined remaining solvent volume.

  20. Light up My Life

    Science.gov (United States)

    Kellett, Sarah

    2015-01-01

    Simply stated, light is nature's way of transferring energy through space. Discussions of light usually refer to visible light, which is perceived by the human eye and is responsible for the sense of sight. We see however, only a small part of the light spectrum. Light connects us as we sit and tell yarns around camp fires. Yet, one in every four…

  1. Mobile lighting apparatus

    Science.gov (United States)

    Roe, George Michael; Klebanoff, Leonard Elliott; Rea, Gerald W; Drake, Robert A; Johnson, Terry A; Wingert, Steven John; Damberger, Thomas A; Skradski, Thomas J; Radley, Christopher James; Oros, James M; Schuttinger, Paul G; Grupp, David J; Prey, Stephen Carl

    2013-05-14

    A mobile lighting apparatus includes a portable frame such as a moveable trailer or skid having a light tower thereon. The light tower is moveable from a stowed position to a deployed position. A hydrogen-powered fuel cell is located on the portable frame to provide electrical power to an array of the energy efficient lights located on the light tower.

  2. Next Generation Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    potential of this new ‘drone-like’ light-printed, light-driven, light-actuated micro- and nano-robotics in challenging geometries requires a versatile and real-time reconfigurable light addressing that can dynamically track a plurality of tiny tools in 3D to ensure real-time continuous light...

  3. Light up My Life

    Science.gov (United States)

    Kellett, Sarah

    2015-01-01

    Simply stated, light is nature's way of transferring energy through space. Discussions of light usually refer to visible light, which is perceived by the human eye and is responsible for the sense of sight. We see however, only a small part of the light spectrum. Light connects us as we sit and tell yarns around camp fires. Yet, one in every four…

  4. Energy Efficient Task Light

    DEFF Research Database (Denmark)

    Logadottir, Asta; Ardkapan, Siamak Rahimi; Johnsen, Kjeld

    2014-01-01

    The objectives of this work is to develop a task light for office lighting that fulfils the minimum requirements of the European standard EN12464 - 1 : Light and lightingLighting of work places, Part 1: Indoor workplaces and the Danish standard DS 700 : Lys og belysning I arbejdsrum , or more...... specifically the requirements that apply to the work area and the immediate surrounding area. By providing a task light that fulfils the requirements for task lighting and the immediate surrounding area, the general lighting only needs to provide the illuminance levels required for background lighting...... and thereby a reduction in installed power for general lighting of about 40 % compared to the way illuminance levels are designed in an office environment in Denmark today. This lighting strategy is useful when the placement of the task area is not defined in the space before the lighting is design ed...

  5. Decolourization of remazol brilliant blue R by enzymatic extract and ...

    African Journals Online (AJOL)

    Ezedom Theresa

    2013-09-25

    Sep 25, 2013 ... ... bodies, which in turn decreases both photosynthetic activity and dissolved ... stable to light, temperature, and microbial attack, making them recalcitrant .... The reaction mixture contained 100 μL enzyme extract and 900 μL ...

  6. Fabrication of InGaN/GaN nanopillar light-emitting diode arrays

    DEFF Research Database (Denmark)

    Ou, Yiyu; Fadil, Ahmed; Ou, Haiyan

    Nanopillar InGaN/GaN green light-emitting diode arrays were fabricated by using self-assembled nanopatterning and dry etching process. Both internal and external quantum efficiency were increased due to strain relaxation and enhanced light extraction.......Nanopillar InGaN/GaN green light-emitting diode arrays were fabricated by using self-assembled nanopatterning and dry etching process. Both internal and external quantum efficiency were increased due to strain relaxation and enhanced light extraction....

  7. White LED with High Package Extraction Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Yi Zheng; Matthew Stough

    2008-09-30

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

  8. Luminescence enhancement of near ultraviolet light-emitting diodes

    DEFF Research Database (Denmark)

    Lin, Li; Jensen, Flemming; Herstrøm, Berit

    2016-01-01

    Nanopillars were applied on the p-GaN layer of the InGaN-based near ultraviolet epiwafer to improve the light extraction efficiency. A photoluminescence enhancement of 74 % is reported with a nanopillar height of around 105 nm.......Nanopillars were applied on the p-GaN layer of the InGaN-based near ultraviolet epiwafer to improve the light extraction efficiency. A photoluminescence enhancement of 74 % is reported with a nanopillar height of around 105 nm....

  9. OLED with improved light outcoupling

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Stephen; Sun, Yiru

    2016-11-29

    An OLED may include regions of a material having a refractive index less than that of the substrate, or of the organic region, allowing for emitted light in a waveguide mode to be extracted into air. These regions can be placed adjacent to the emissive regions of an OLED in a direction parallel to the electrodes. The substrate may also be given a nonstandard shape to further improve the conversion of waveguide mode and/or glass mode light to air mode. The outcoupling efficiency of such a device may be up to two to three times the efficiency of a standard OLED. Methods for fabricating such a transparent or top-emitting OLED is also provided.

  10. The extractive metallurgy of gold

    Science.gov (United States)

    Kongolo, K.; Mwema, M. D.

    1998-12-01

    Mössbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Mössbauer spectroscopy could be applied.

  11. Hot Carrier extraction with plasmonic broadband absorbers

    CERN Document Server

    Ng, Charlene; Dligatch, Svetlana; Roberts, Ann; Davis, Timothy J; Mulvaney, Paul; Gomez, Daniel E

    2016-01-01

    Hot charge carrier extraction from metallic nanostructures is a very promising approach for applications in photo-catalysis, photovoltaics and photodetection. One limitation is that many metallic nanostructures support a single plasmon resonance thus restricting the light-to-charge-carrier activity to a spectral band. Here we demonstrate that a monolayer of plasmonic nanoparticles can be assembled on a multi-stack layered configuration to achieve broad-band, near-unit light absorption, which is spatially localised on the nanoparticle layer. We show that this enhanced light absorbance leads to $\\sim$ 40-fold increases in the photon-to-electron conversion efficiency by the plasmonic nanostructures. We developed a model that successfully captures the essential physics of the plasmonic hot-electron charge generation and separation in these structures. This model also allowed us to establish that efficient hot carrier extraction is limited to spectral regions where the photons possessing energies higher than the S...

  12. Light Trapping: Light Manipulation in Organic Photovoltaics (Adv. Sci. 7/2016)

    OpenAIRE

    Ou, Qing‐Dong; Li, Yan‐Qing; Tang, Jian‐Xin

    2016-01-01

    Light manipulation is becoming a general strategy for further enhancing the performance of organic photovoltaic cells. In article 1600123, various light trapping schemes are reviewed from the viewpoint of plasmonic and photonic resonances, addressing the external antireflection coatings, substrate geometry‐induced trapping, the role of electrode design in optical enhancement, as well as optically modifying charge extraction and photoactive layers by Jian‐Xin Tang and co‐workers.

  13. Light as experiential material

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Søndergaard, Karin

    2013-01-01

    'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which the experience and design of architectural lighting can be approached in research and education......'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which the experience and design of architectural lighting can be approached in research and education...

  14. Light as experiential material

    DEFF Research Database (Denmark)

    Søndergaard, Karin; Petersen, Kjell Yngve

    2013-01-01

    'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education.......'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education....

  15. Light as experiential material

    DEFF Research Database (Denmark)

    Søndergaard, Karin; Petersen, Kjell Yngve

    2013-01-01

    'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education.......'Light as experiential material' is concerned with the development of a psychophysical method of investigation, by which we can approach the experience and design of architectural lighting in research and education....

  16. Pedestrian Friendly Outdoor Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koltai, R. N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGowan, T. K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    The GATEWAY program followed two pedestrian-scale lighting projects that required multiple mockups – one at Stanford University in California and the other at Chautauqua Institution in upstate New York. The report provides insight into pedestrian lighting criteria, how they differ from street and area lighting criteria, and how solid-state lighting can be better applied in pedestrian applications.

  17. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  18. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  19. Outdoor lighting guide

    CERN Document Server

    2013-01-01

    As concern grows over environmental issues and light pollution, this book satisfies a need for a straightforward and accessible guide to the use, design and installation of outdoor lighting.This all-inclusive guide to exterior lighting from the Institution of Lighting Engineers, recognized as the pre-eminent professional source in the UK for authoritative guidance on exterior lighting, provides a comprehensive source of information and advice on all forms of exterior lighting, from floodlighting, buildings and road lighting to elaborate Christmas decorations. Useful to practitioners

  20. All-digital wavefront sensing for structured light beams

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2014-01-01

    Full Text Available We present a new all-digital technique to extract the wavefront of a structured light beam. Our method employs non-homogeneous polarization optics together with dynamic, digital holograms written to a spatial light modulator to measure the phase...

  1. Light and colours

    DEFF Research Database (Denmark)

    Volf, Carlo

    2011-01-01

    Often a dichotomy between daylight and artificial light is observed, often artificial lighting replaces daylight. In Denmark daylight is characterized partly by being "borrowed" half of the year, partly by having long transitions periods between the light and the dark (nautical and civil twilight......). For these reasons artificial lighting does not complement daylight but provides, coupled with the daylight, the total lighting in the indoor environment. Electric lighting is therefore ‐ in a complex interaction with the daylight ‐ of great importance for both our lighting and our wellbeing. Studying artificial...... lighting without studying daylight seem to be a common procedure of the practice of today in Denmark and other parts of the industrialized world. As a consequence of this artificial lighting suffers from a quantifying tyranny, a tyranny where the quality of light is measured in quantities. This procedure...

  2. Light and colours

    DEFF Research Database (Denmark)

    Volf, Carlo

    2011-01-01

    Often a dichotomy between daylight and artificial light is observed, often artificial lighting replaces daylight. In Denmark daylight is characterized partly by being "borrowed" half of the year, partly by having long transitions periods between the light and the dark (nautical and civil twilight......). For these reasons artificial lighting does not complement daylight but provides, coupled with the daylight, the total lighting in the indoor environment. Electric lighting is therefore ‐ in a complex interaction with the daylight ‐ of great importance for both our lighting and our wellbeing. Studying artificial...... lighting without studying daylight seem to be a common procedure of the practice of today in Denmark and other parts of the industrialized world. As a consequence of this artificial lighting suffers from a quantifying tyranny, a tyranny where the quality of light is measured in quantities. This procedure...

  3. Heavy-heavy-light-light correlators in Liouville theory

    Science.gov (United States)

    Balasubramanian, V.; Bernamonti, A.; Craps, B.; De Jonckheere, T.; Galli, F.

    2017-08-01

    We compute four-point functions of two heavy and two "perturbatively heavy" operators in the semiclassical limit of Liouville theory on the sphere. We obtain these "Heavy-Heavy-Light-Light" (HHLL) correlators to leading order in the conformal weights of the light insertions in two ways: (a) via a path integral approach, combining different methods to evaluate correlation functions from complex solutions for the Liouville field, and (b) via the conformal block expansion. This latter approach identifies an integral over the continuum of normalizable states and a sum over an infinite tower of lighter discrete states, whose contribution we extract by analytically continuing standard results to our HHLL setting. The sum over this tower reproduces the sum over those complex saddlepoints of the path integral that contribute to the correlator. Our path integral computations reveal that when the two light operators are inserted at equal time in radial quantization, the leading-order HHLL correlator is independent of their separation, and more generally that at this order there is no short-distance singularity as the two light operators approach each other. The conformal block expansion likewise shows that in the discrete sum short-distance singularities are indeed absent for all intermediate states that contribute. In particular, the Virasoro vacuum block, which would have been singular at short distances, is not exchanged. The separation-independence of equal-time correlators is due to cancelations between the discrete contributions. These features lead to a Lorentzian singularity that, in conformal theories with anti-de Sitter (AdS) duals, would be associated to locality below the AdS scale.

  4. Occlusion, transparency, and lightness

    OpenAIRE

    2007-01-01

    The lightness of a visual surface is its perceived achromatic reflectance [Adelson, E. H., (2000). Lightness perception and lightness illusions. In M. Gazzaniga (Ed.), The new cognitive neuroscience (2nd ed.) (pp. 339-351) Berlin: Springer; Gilchrist, A. (1999). Lightness perception. In R. W. F. Keil (Ed.), MIT encyclopedia of cognitive science (pp. 471-472). Cambridge: MIT press]. Lightness ranges from black, through various shades of grey, up to white. Anderson and Winawer [Anderson, B., Wi...

  5. Extraction parameters for metabolomics from cell extracts

    Science.gov (United States)

    Ser, Zheng; Liu, Xiaojing; Tang, Ngoc Nu; Locasale, Jason W

    2015-01-01

    The successful extraction of metabolites is a critical step in metabolite profiling. By optimizing metabolite extraction, the range and quantitative capacity of metabolomics studies can be improved. We considered eight separate extraction protocols for the preparation of a metabolite extract from cultured mammalian cells. Parameters considered included temperature, pH, and cell washing before extraction. The effects on metabolite recovery were studied using a high resolution liquid chromatography mass spectrometry (LC-HRMS) platform that measures metabolites of diverse chemical classes including among others amino acids, lipids, and sugar derivatives. The temperature considered during the extraction or the presence of formic acid, a commonly used additive, was shown to have minimal effects on the measured ion intensities of metabolites. However, washing of samples before metabolite extraction whether with water or PBS (both commonly considered practices) exhibited dramatic effects on measured intensities of both intra- and extra-cellular metabolites. Together these findings present a systematic assessment of extraction conditions for metabolite profiling. PMID:25613493

  6. The Properties of Light

    Science.gov (United States)

    Haglund, Richard F.

    The mystery of light has formed the core of creation stories in every culture, and attracted the earnest attentions of philosophers since at least the fifth century BCE. Their questions have ranged from how and what we see, to the interaction of light with material bodies, and finally to the nature of light itself. This chapter begins with a brief intellectual history of light from ancient Greece to the end of the 19th century. After introducing the physical parameterization of light in terms of standard units, three concepts of light are introduced: light as a wave, light as a quantum particle, and light as a quantum field. After highlighting the distinctive characteristics of light beams from various sources - thermal radiation, luminescence from atoms and molecules, and synchrotron light sources - the distinctive physical characteristics of light beams are examined in some detail. The chapter concludes with a survey of the statistical and quantum-mechanical properties of light beams. In the appropriate limits, this treatment not only recovers the classical description of light waves and the semiclassical view of light as a stream of quanta, but also forms a consistent description of quantum phenomena - such as interference phenomena generated by single photons - that have no classical analogs.

  7. Extraction Behaviors of Heavy Rare Earths with Organophosphoric Extractants: The Contribution of Extractant Dimer Dissociation, Acid Ionization, and Complexation. A Quantum Chemistry Study.

    Science.gov (United States)

    Jing, Yu; Chen, Ji; Chen, Li; Su, Wenrou; Liu, Yu; Li, Deqian

    2017-03-30

    Heavy rare earths (HREs), namely Ho(3+), Er(3+), Tm(3+), Yb(3+) and Lu(3+), are rarer and more exceptional than light rare earths, due to the stronger extraction capacity for 100 000 extractions. Therefore, their incomplete stripping and high acidity of stripping become problems for HRE separation by organophosphoric extractants. However, the theories of extractant structure-performance relationship and molecular design method of novel HRE extractants are still not perfect. Beyond the coordination chemistry of the HRE-extracted complex, the extractant dimer dissociation, acid ionization, and complexation behaviors can be crucial to HRE extraction and reactivity of ionic species for understanding and further improving the extraction performance. To address the above issues, three primary fundamental processes, including extractant dimer dissociation, acid ionization, and HRE complexation, were identified and investigated systematically. The intrinsic extraction performances of HRE cations with four acidic organophosphoric extractants (P507, P204, P227 and Cyanex 272) were studied by using relativistic energy-consistent 4f core pseudopotentials, combined with density functional theory and a solvation model. Four acidic organophosphoric extractants have been qualified quantitatively from microscopic structures to chemical properties. It has been found that the Gibbs free energy changes of the overall extraction process (sequence: P204 > P227 > P507 > Cyanex 272) and their differences as a function of HREs (sequence: Ho/Er > Er/Tm > Tm/Yb > Yb/Lu) are in good agreement with the experimental maximum extraction capacities and separation factors. These results could provide an important approach to evaluate HRE extractants by the comprehensive consideration of dimer dissociation, acid ionization, and complexation processes. This paper also demonstrates the importance of the P-O bond, the P-C bond, isomer substituent, and solvation effects on the structure

  8. All-digital wavefront sensing for structured light beams.

    Science.gov (United States)

    Dudley, Angela; Milione, Giovanni; Alfano, Robert R; Forbes, Andrew

    2014-06-02

    We present a new all-digital technique to extract the wavefront of a structured light beam. Our method employs non-homogeneous polarization optics together with dynamic, digital holograms written to a spatial light modulator to measure the phase relationship between orthogonal polarization states in real-time, thereby accessing the wavefront information. Importantly, we show how this can be applied to measuring the wavefront of propagating light fields, over extended distances, without any moving components. We illustrate the versatility of the tool by measuring propagating optical vortices, Bessel, Airy and speckle fields. The comparison of the extracted and programmed wavefronts yields excellent agreement.

  9. Electroluminescent device having improved light output

    Energy Technology Data Exchange (ETDEWEB)

    Tyan; Yuan-Sheng (Webster, NY); Preuss, Donald R. (Rochester, NY); Farruggia, Giuseppe (Webster, NY); Kesel, Raymond A. (Avon, NY); Cushman, Thomas R. (Rochester, NY)

    2011-03-22

    An OLED device including a transparent substrate having a first surface and a second surface, a transparent electrode layer disposed over the first surface of the substrate, a short reduction layer disposed over the transparent electrode layer, an organic light-emitting element disposed over the short reduction layer and including at least one light-emitting layer and a charge injection layer disposed over the light emitting layer, a reflective electrode layer disposed over the charge injection layer and a light extraction enhancement structure disposed over the first or second surface of the substrate; wherein the short reduction layer is a transparent film having a through-thickness resistivity of 10.sup.-9 to 10.sup.2 ohm-cm.sup.2; wherein the reflective electrode layer includes Ag or Ag alloy containing more than 80% of Ag; and the total device size is larger than 10 times the substrate thickness.

  10. Light-emitting nanolattices with enhanced brightness

    Science.gov (United States)

    Ng, Ryan C.; Mandal, Rajib; Anthony, Rebecca J.; Greer, Julia R.

    2017-02-01

    Three-dimensional (3D) photonic crystals have potential in solid state lighting applications due to their advantages over conventional planar thin film devices. Periodicity in a photonic crystal structure enables engineering of the density of states to improve spontaneous light emission according to Fermi's golden rule. Unlike planar thin films, which suffer significantly from total internal reflection, a 3D architectured structure is distributed in space with many non-flat interfaces, which facilitates a substantial enhancement in light extraction. We demonstrate the fabrication of 3D nano-architectures with octahedron geometry that utilize luminescing silicon nanocrystals as active media with an aluminum cathode and indium tin oxide anode towards the realization of a 3D light emitting device. The developed fabrication procedure allows charge to pass through the nanolattice between two contacts for electroluminescence. These initial fabrication efforts suggest that 3D nano-architected devices are realizable and can reach greater efficiencies than planar devices.

  11. Grape Seed Extract

    Science.gov (United States)

    ... to reduce inflammation. Grape seed extract contains the antioxidant compound oligomeric proanthocyanidin (OPC), which has been studied for a variety of health conditions. OPCs are found in extracts of grape skin and seeds, which are by-products of the ...

  12. Lamps and lighting

    CERN Document Server

    Cayless, MA; Marsden, A M

    2012-01-01

    This book is a comprehensive guide to the theory and practice of lighting. Covering the physics of light production, light sources, circuits and a wide variety of lighting applications, it is both suitable as a detailed textbook and as thoroughly practical guide for practising lighting engineers. This fourth edition of Lamps and Lighting has been completely updated with new chapters on the latest lamp technology and applications. The editors ahve called upon a wide range of expertise and as a result many sections have been broadened to include both European and US practice.The book begins with

  13. The design of lighting

    CERN Document Server

    Tregenza, Peter

    2013-01-01

    This fully updated edition of the successful book The Design of Lighting, provides the lighting knowledge needed by the architect in practice, the interior designer and students of both disciplines. The new edition offers a clear structure, carefully selected material and linking of lighting with other subjects, in order to provide the reader with a comprehensive and specifically architectural approach to lighting. Features of this new edition include:technical knowledge of lighting in the context of architectural design;an emphasis on imagination in architectural light and presentation of the

  14. Method of infusion extraction

    Science.gov (United States)

    Chang-Diaz, Franklin R. (Inventor)

    1989-01-01

    Apparatus and method of removing desirable constituents from an infusible material by infusion extraction, where a piston operating in a first chamber draws a solvent into the first chamber where it may be heated, and then moves the heated solvent into a second chamber containing the infusible material, and where infusion extraction takes place. The piston then moves the solvent containing the extract through a filter into the first chamber, leaving the extraction residue in the second chamber.

  15. Asymmetric extractions in orthodontics

    OpenAIRE

    Camilo Aquino Melgaço; Mônica Tirre de Souza Araújo

    2012-01-01

    INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portugue...

  16. Information extraction system

    Science.gov (United States)

    Lemmond, Tracy D; Hanley, William G; Guensche, Joseph Wendell; Perry, Nathan C; Nitao, John J; Kidwell, Paul Brandon; Boakye, Kofi Agyeman; Glaser, Ron E; Prenger, Ryan James

    2014-05-13

    An information extraction system and methods of operating the system are provided. In particular, an information extraction system for performing meta-extraction of named entities of people, organizations, and locations as well as relationships and events from text documents are described herein.

  17. Frequency of orthodontic extraction

    Directory of Open Access Journals (Sweden)

    Camila de S. Dardengo

    2016-02-01

    Full Text Available Introduction: The option of dental extraction for orthodontic purposes has been debated for more than 100 years, including periods when it was widely used in treatment, including the present, during which other methods are used to avoid dental extractions. The objective was to analyze the frequency of tooth extraction treatment performed between 1980 and 2011 at the Orthodontic Clinic of Universidade Estadual do Rio de Janeiro (UERJ. Material and Methods: The clinical records of 1484 patients undergoing orthodontic treatment were evaluated. The frequency of extractions was evaluated with regard to sex, Angle's classification, the different combinations of extractions and the period when orthodontic treatment began. Chi-square test was used to determine correlations between variables, while the chi-square test for trends was used to assess the frequency of extractions over the years. Results: There was a reduction of approximately 20% in the frequency of cases treated with tooth extraction over the last 32 years. The most frequently extracted teeth were first premolars. Patients with Class I malocclusion showed fewer extractions, while Class II patients underwent a higher number of extraction treatment. There were no statistically significant differences with regard to sex. Conclusion: New features introduced into the orthodontic clinic and new esthetic concepts contributed to reducing the number of cases treated with dental extractions. However, dental extractions for orthodontic purposes are still well indicated in certain cases.

  18. Determination of the platycodin D in platycodon Grandiflorum extracts using reversed phase-high performance Liquid Chromatography-Evaporative Light-scattering Detector%RP-HPLC-ELSD法测定贝杏止咳膏中桔梗皂苷D的含量

    Institute of Scientific and Technical Information of China (English)

    龙芳

    2011-01-01

    Objective A method for the determination of the platycodin D in Platycodon Grandiflorum extracts was developed using reversed phase-high performance Liquid Chromatography- Evaporative Light-scattering Detector(RP-HPLC-ELSD). Methods The RP-HPLC-ELSD separation was carried out on a C18 (4.6 mm×250 mm,5 μm) with Acetonitrile-water(25:75,v/v) as mobile phase at a flow rate of 0.5 mL/min in 30 ℃, and detected at 210 nm. Results The mean recoveries of RP-HPLCELSD were 97.62%, and the relative standard deviations(RSD)were 0.84%(n=6). Conclusions The method of RP-HPLC-ELSD is convenient ,accurate and trustworthy. And could be used for Quality control of the platycodon Grandiflorum%目的:建立反相高效液相色谱-蒸发光散射检测法(RP-HPLC-ELSD)测定贝杏止咳膏中桔梗皂苷D含量的方法.方法:以甲醇溶液沉淀贝杏止咳膏中的蛋白,同时提取桔梗皂苷D,采用十八烷基硅烷键合硅胶色谱柱;流动相为乙腈-水(25∶75);流速为0.5 mL/min;蒸发光散射检测器检测,波长为210 nm;柱温为30 ℃.结果:RP-HPLC-ELSD的平均加样回收率为97.62%,RSD%为0.84%(n=6).结论:该方法简便易行,准确可靠,可用于贝杏止咳膏的质量控制.

  19. GPC Light Shaper

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Raaby, Peter; Glückstad, Jesper

    Generalized Phase Contrast is a disruptive light sculpting technology for studying brain functionalities via light-activated neuron control. GPC dynamically reshapes conventional or multiwavelength lasers for precise and efficient neuron targeting. GPC also makes existing laser systems much more...

  20. Spectrally tunable lighting facility

    Data.gov (United States)

    Federal Laboratory Consortium — Solid-state lighting (SSL) is increasingly being introduced into the market and it is expected that many of the light sources currently used for general illumination...

  1. Light Imaging Section

    Data.gov (United States)

    Federal Laboratory Consortium — The mission of the Light Imaging Section is to give NIAMS scientists access to state-of-the-art light imaging equipment and to offer training and assistance at all...

  2. Interference and Polarized Light.

    Science.gov (United States)

    Charas, Seymour

    1988-01-01

    Discusses a demonstration of interference phenomena using three sheets of polaroid material, a light source, and a light meter. Describes instructional procedures with mathematical expressions and a diagram. (YP)

  3. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  4. Lighting detectives forum

    DEFF Research Database (Denmark)

    Bülow, Katja; Skindbjerg Kristensen, Lisbeth

    2003-01-01

    Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003.......Belysning for boligområder var emnet for lighting detectives forum, der blev afholdt i Stockholm i august 2003....

  5. Simultaneous determination of five synthetic sweeteners in food by solid phase extraction-high performance liquid chromatography-evaporative light scattering detection%固相萃取-高效液相色谱-蒸发光散射检测法同时检测食品中5种人工合成甜味剂

    Institute of Scientific and Technical Information of China (English)

    刘芳; 王彦; 王玉红; 周君裔; 阎超

    2012-01-01

    A high performance liquid chromatographic method with evaporative light scattering detection (HPLC-ELSD) was developed for the simultaneous determination of five synthetic sweeteners (acesulfame-K, saccharin sodium, sodium cyclamate, sucralose and aspartame) in food. The sweeteners were extracted by 0. 1% (v/v) formic acid buffer solution. The extract of sample was cleaned up and concentrated with solid phase extraction (SPE) cartridge. Then the sweeteners were separated on a C18 column (3μm) using 0. 1% (v/v) formic acid buffer (adjusted to pH =3.5 with aqueous ammonia solution)-methanol (61: 39, v/v) as mobile phase, and finally detected by ELSD. The results showed that the reasonable linearity was achieved for all the analytes over the range of 30 - 1 000 mg/L with the correlation coefficients (r) greater than 0. 997. The recoveries for the five sweeteners ranged from 85. 6% to 109. 0% at three spiked concentrations with the relative standard deviations ( RSDs) lower than 4. 0%. The limits of detection (LODs, S/N = 3) were 2. 5 mg/L for both acesulfame-K and sucralose, 3 mg/L for saccharin sodium, 10 mg/L for sodium cyclamate, and 5 mg/L for aspartame. The method is simple,sensitive and low cost,and has been successfully applied to the simultaneous determination of the five synthetic sweeteners in food.%建立了高效液相色谱-蒸发光散射检测仪( HPLC-ELSD)同时检测食品中安赛蜜、糖精钠、甜蜜素、三氯蔗糖和阿斯巴甜5种甜味剂的方法.甜味剂经0.1% (v/v)甲酸缓冲液提取后,利用C18固相萃取小柱净化浓缩,以3μmC18柱为分离柱,0.1% (v/v)甲酸(氨水调节pH =3.5)-甲醇(61∶39,v/v)为流动相,经高效液相色谱法分离,蒸发光散射检测器进行检测.结果表明,5种甜味剂在30~1 000 mg/L的范围内,具有良好的线性关系(相关系数大于0.997);在3个添加水平下,样品的平均回收率为85.6% ~ 109.0%,相对标准偏差小于4.0%;方

  6. The landscape lighting book

    CERN Document Server

    Moyer, Janet Lennox

    2013-01-01

    This richly illustrated, up-to-date guide offers practical coverage of all aspects of lighting design. Written by an award-winning, internationally known lighting designer, it covers lighting practices, materials, and their design applications and offers guidelines for preparing lighting drawings, control and transfer charts, symbol lists, and other technical specifications. This edition provides a new focus on the use of LEDs, as well as new and expanded coverage of renderings, Mesopic Vision, and the latest controls approaches and systems.

  7. OLED displays and lighting

    CERN Document Server

    Koden, Mitsuhiro

    2017-01-01

    Organic light-emitting diodes (OLEDs) have emerged as the leading technology for the new display and lighting market. OLEDs are solid-state devices composed of thin films of organic molecules that create light with the application of electricity. OLEDs can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today. This book covers both the fundamentals and practical applications of flat and flexible OLEDs.

  8. Geolocation by light

    DEFF Research Database (Denmark)

    Lisovski, Simeon; Hewson, Chris M.; Klaassen, Raymond H. G.

    2012-01-01

    1. Geolocation by light allows for tracking animal movements, based on measurements of light intensity over time by a data-logging device (‘geolocator’). Recent developments of ultra-light devices (<2 g) broadened the range of target species and boosted the number of studies using geolocators. Ho...

  9. LEDs for greenhouse lighting

    NARCIS (Netherlands)

    Nederhoff, E.M.

    2010-01-01

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

  10. Simulating Supernova Light Curves

    Energy Technology Data Exchange (ETDEWEB)

    Even, Wesley Paul [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dolence, Joshua C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    This report discusses supernova light simulations. A brief review of supernovae, basics of supernova light curves, simulation tools used at LANL, and supernova results are included. Further, it happens that many of the same methods used to generate simulated supernova light curves can also be used to model the emission from fireballs generated by explosions in the earth’s atmosphere.

  11. Light in man's environment.

    Science.gov (United States)

    Marshall, J

    2016-02-01

    Light in the form of solar radiation influenced early civilisations and resulted in the independent development of a number of sun-worshipping dieties. These were of particular importance as hunter gatherers transformed into settled agricultural societies. All artificial light sources were synonymous with fire, and early civilisations began to expand their visual day by burning brands, oil, and candles. Fire-based light sources extended for thousands of years and were still present in the era of gas lighting. Light meant fire risk. The advent of incandescent bulbs and the era of electric lighting really only expanded in the early part of the twentieth century. Fluorescent lighting became available in the 1940s, and today the drive for low energy has resulted in a plethora of novel light sources-in particular, light-emitting diodes (LEDs). Evolution governed the development of the eye in relation to roughly 12 h of light gradually changing to 12 h of darkness. Today almost daylight levels can be achieved abruptly at the flick of a switch. Many studies have demonstrated the spectral dependence of eye health, with the retinal hazard zone associated with wavelengths in the blue, peaking at 441 nm- many of today's low-energy sources peak in this region. Given the increased longevity and artificial light sources emitting at biologically unfriendly wavelengths, attention has to be directed towards light in man's environment as a risk factor in age-related ocular diseases.

  12. Plants under continuous light

    NARCIS (Netherlands)

    Velez Ramirez, A.I.; Ieperen, van W.; Vreugdenhill, D.; Millenaar, F.F.

    2011-01-01

    Continuous light is an essential tool for understanding the plant circadian clock. Additionally, continuous light might increase greenhouse food production. However, using continuous light in research and practice has its challenges. For instance, most of the circadian clock-oriented experiments wer

  13. Seeing the Light

    Science.gov (United States)

    Sportel, Samuel; Bruxvoort, Crystal; Jadrich, James

    2009-01-01

    Conceptually, students are typically introduced to light as a type of wave. However, children struggle to understand this model because it is highly abstract. Light can be represented more concretely using the photon model. According to this scientific model, light emanates from sources as tiny "packets" of energy (called "photons") that move in…

  14. Seeing the Light

    Science.gov (United States)

    Sportel, Samuel; Bruxvoort, Crystal; Jadrich, James

    2009-01-01

    Conceptually, students are typically introduced to light as a type of wave. However, children struggle to understand this model because it is highly abstract. Light can be represented more concretely using the photon model. According to this scientific model, light emanates from sources as tiny "packets" of energy (called "photons") that move in…

  15. Light On the Behavior of Light Bulbs.

    Science.gov (United States)

    Armstrong, H. L.

    1985-01-01

    Discusses a problem (on page 523 of "College Physics," by Sears, Zemansky, and Young, published by Addison-Wesley, 1980) concerning light bulbs and resistance. Shows why the assumption of constant resistance is unrealistic and provides guidelines for revision. (DH)

  16. Light On the Behavior of Light Bulbs.

    Science.gov (United States)

    Armstrong, H. L.

    1985-01-01

    Discusses a problem (on page 523 of "College Physics," by Sears, Zemansky, and Young, published by Addison-Wesley, 1980) concerning light bulbs and resistance. Shows why the assumption of constant resistance is unrealistic and provides guidelines for revision. (DH)

  17. Regulation of Ribulose Bisphosphate Carboxylase Activity in Intact Wheat Leaves by Light, CO2, and Temperature

    OpenAIRE

    MÄCHLER, F.; NÖSBERGER, J.

    2017-01-01

    The activity of the enzyme ribulose bisphosphate carboxylase (RuBPCase) was estimated after rapidly extracting it from intact wheat leaves pretreated under different light and CO2 levels. No HCO3− was added to the extraction buffer since it is shown to inhibit RuBPCase. The activity increased as light intensity or CO2 concentration during pretreatment was increased. Enzyme activity increased as temperature during pretreatment was decreased. Light activation did not affect the affinity of RuBP...

  18. Extraction of uranium (VI) from nitric acidwith N-decanoylpyrrolidine (DPOD) in toluene

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The extraction behaviors of uranium (VI) from nitric acid by N-decanoylpyrrolidine (DPOD) in toluene has been studied at varying concentrations of nitric acid, extractant, salting-out agent LiNO3 and at different temperatures.The mechanism of extraction is discussedin the light of the results obtained.

  19. Roadmap on structured light

    Science.gov (United States)

    Rubinsztein-Dunlop, Halina; Forbes, Andrew; Berry, M. V.; Dennis, M. R.; Andrews, David L.; Mansuripur, Masud; Denz, Cornelia; Alpmann, Christina; Banzer, Peter; Bauer, Thomas; Karimi, Ebrahim; Marrucci, Lorenzo; Padgett, Miles; Ritsch-Marte, Monika; Litchinitser, Natalia M.; Bigelow, Nicholas P.; Rosales-Guzmán, C.; Belmonte, A.; Torres, J. P.; Neely, Tyler W.; Baker, Mark; Gordon, Reuven; Stilgoe, Alexander B.; Romero, Jacquiline; White, Andrew G.; Fickler, Robert; Willner, Alan E.; Xie, Guodong; McMorran, Benjamin; Weiner, Andrew M.

    2017-01-01

    Structured light refers to the generation and application of custom light fields. As the tools and technology to create and detect structured light have evolved, steadily the applications have begun to emerge. This roadmap touches on the key fields within structured light from the perspective of experts in those areas, providing insight into the current state and the challenges their respective fields face. Collectively the roadmap outlines the venerable nature of structured light research and the exciting prospects for the future that are yet to be realized.

  20. Resonant-cavity based monolithic white light-emitting diode

    Science.gov (United States)

    Huang, Lirong; Huang, Dexiu; Wen, Feng

    2007-11-01

    We propose a new scheme of resonant-cavity (RC) based monolithic white LED, it relaxes the hard requirement of high internal quantum efficiency of yellow multi-quantum (MQW) and offers an easy way to obtain high luminous efficacy white light emission. In the proposed white LED, the blue MQW and yellow MQW active layer are embedded in a resonant-cavity defined by the bottom distributed Bragg reflector(DBR) and top DBR. For a optimal design of RC-based white LED, the extraction efficiency for yellow light is enhanced, while that for blue light is suppressed, thus intensity ratio of yellow light in the emitting light is increased, which not only helps to obtain white emission in spite of the low internal quantum efficiency of yellow light, but also doubles luminous efficacy. The color coordinates and luminous flux of the emitting light from RC-based white LED are calculated and the performance dependence on directionality is investigated.

  1. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black......This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  2. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    2007-01-01

    2006, and supervisory authorities in many other European countries have implemented similar regulation. Traffic light options are therefore likely to attract the attention of a wider audience of pension fund managers in the future. Focusing on the valuation of the traffic light option we set up a Black......This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  3. Engineering photonic and plasmonic light emission enhancement

    Science.gov (United States)

    Lawrence, Nathaniel

    Semiconductor photonic devices are a rapidly maturing technology which currently occupy multi-billion dollar markets in the areas of LED lighting and optical data communication. LEDs currently demonstrate the highest luminous efficiency of any light source for general lighting. Long-haul optical data communication currently forms the backbone of the global communication network. Proper design of light management is required for photonic devices, which can increase the overall efficiency or add new device functionality. In this thesis, novel methods for the control of light propagation and confinement are developed for the use in integrated photonic devices. The first part of this work focuses on the engineering of field confinement within deep subwavelength plasmonic resonators for the enhancement of light-matter interaction. In this section, plasmonic ring nanocavities are shown to form gap plasmon modes confined to the dielectric region between two metal layers. The scattering properties, near-field enhancement and photonic density of states of nanocavity devices are studied using analytic theory and 3D finite difference time domain simulations. Plasmonic ring nanocavities are fabricated and characterized using photoluminescence intensity and decay rate measurements. A 25 times increase in the radiative decay rate of Er:Si02 is demonstrated in nanocavities where light is confined to volumes as small as 0.01( ln )3. The potential to achieve lasing, due to the enhancement of stimulated emission rate in ring nanocavities, is studied as a route to Si-compatible plasmon-enhanced nanolasers. The second part of this work focuses on the manipulation of light generated in planar semiconductor devices using arrays of dielectric nanopillars. In particular, aperiodic arrays of nanopillars are engineered for omnidirectional light extraction enhancement. Arrays of Er:SiNx, nanopillars are fabricated and a ten times increase in light extraction is experimentally demonstrated

  4. Cooperatively enhanced light transmission in cold atomic matter

    CERN Document Server

    Kemp, Kasie; Havey, M D; Sokolov, I M; Kupriyanov, D V

    2014-01-01

    We report enhanced transmission in measurements of the spectral dependence of forward light scattering by a high-density and cold ensemble of 87Rb atoms. This phenomenon, which is a result of dipole-dipole interaction induced cooperative light scattering in the atomic sample, implies a significant departure from the traditional density dependence of the transmitted light as embodied in the Beer-Lambert Law. Absolute values of the density-dependent forward light scattering cross-section are extracted from the measurements.

  5. Visible light metasurfaces based on gallium nitride high contrast gratings

    Science.gov (United States)

    Wang, Zhenhai; He, Shumin; Liu, Qifa; Wang, Wei

    2016-05-01

    We propose visible-light metasurfaces (VLMs) capable of serving as lens and beam deflecting element based on gallium nitride (GaN) high contrast gratings (HCGs). By precisely manipulating the wavefront of the transmitted light, we theoretically demonstrate an HCG focusing lens with transmissivity of 86.3%, and a VLM with beam deflection angle of 6.09° and transmissivity as high as 91.4%. The proposed all-dielectric metasurfaces are promising for GaN-based visible light-emitting diodes (LEDs), which would be robust and versatile for controlling the output light propagation and polarization, as well as enhancing the extraction efficiency of the LEDs.

  6. Organization of extracting molecules of the diamide type: link with the extracting properties?; Organisation des molecules extractantes de type diamide: lien avec les proprietes extractantes?

    Energy Technology Data Exchange (ETDEWEB)

    Meridiano, Y.

    2009-02-15

    The aim of these studies is to establish a link between the different organizations of diamide extractants (used in the DIAMEX process) and their extracting properties. The effects of the key parameters leading the liquid-liquid extraction (concentration of extractant, nature of solute, activity of the aqueous phase, nature of the diluent and temperature) are studied: 1) at the supramolecular scale, with the characterization of the extractant organizations by vapor-pressure osmometry (VPO) and small angle neutron and X-ray scattering (SANS/SAXS) experiments; 2) at the molecular scale, with the quantification of the extracted solutes (water, nitric acid, metal nitrate) and the determination of extracted complexes stoichiometries by electro-spray mass spectrometry (ESI-MS) experiments. The DMDOHEMA molecule acts as a classical surfactant and forms aggregates of the reverse micelle type. Taking into account the established supramolecular diagrams, a quantitative link between the extractants structures and their extracting properties has been brought to light. To model the europium nitrate extraction, two approaches have been developed: - an approach based on mass action laws. Extractions equilibria have been proposed taking into account the supramolecular speciation; - an innovative approach considering the extracted ions as adsorbed on a specific surface of the extractant molecule which depends on the extractant organization state. The ion extraction can be considered as a sum of isotherms corresponding to the different states of organization. This approach allows to compare the extraction efficiency of an extracting molecule as a function of its organization state. (author)

  7. Light nuclei production in heavy ion collisions

    CERN Document Server

    Khan, K H; Wazir, Z; Khan, E U; Haseeb, Mahnaz Q; Ajaz, M

    2009-01-01

    Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

  8. Lanthanide extraction with 2,5-dimethyl-2-hydroxyhexanoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J. H.

    1977-12-01

    This research is concerned with the solvent extraction into chloroform of the lanthanides, using 2,5-dimethyl-2-hydroxyhexanoic acid (DMHHA). This acid is the first ..cap alpha..-hydroxy aliphatic acid to be studied as an extracting agent for the lanthanides. The chloroform-water DMHHA partition constant was determined to be 1.0 (at 0.1 M ionic strength and 25/sup 0/C). The acid dimerizes in chloroform with a constant of 56. The light lanthanides can be extracted into chloroform by forming complexes with the DMHHA anions. The extracted metal species is highly aggregated. This extraction has a solubility limit which increases with the addition of unionized acid. The resultant extract is also highly aggregated. At unionized acid-to-metal ratios greater than one, extractions first occur followed by the slow precipitation of the lanthanide. At the tracer level, neodymium is extracted primarily as NdA/sub 3/(HA)/sub 5/ and (NdA/sub 3/)/sub 2/(HA)/sub q/. Very small amounts of (NdA/sub 3/)/sub 2/ and other metal aggregates are also present. The heavy lanthanides do not extract from solutions of DMHHA and its potassium salt, but form aqueous emulsions and precipitates. In the presence of the organic soluble tetrabutylammonium ion the heavy lanthanides can be extracted, presumably as ion pairs. The stability constants of the light lanthanides and DMHHA were determined. The separation factors obtained from DMHHA extractions of the light lanthanides were also investigated and found to be comparable to those obtained employing normal aliphatic carboxylic acid.

  9. Light Emitting Diodes (LEDs)

    Science.gov (United States)

    1997-01-01

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

  10. Fingerprint Feature Extraction Algorithm

    Directory of Open Access Journals (Sweden)

    Mehala. G

    2014-03-01

    Full Text Available The goal of this paper is to design an efficient Fingerprint Feature Extraction (FFE algorithm to extract the fingerprint features for Automatic Fingerprint Identification Systems (AFIS. FFE algorithm, consists of two major subdivisions, Fingerprint image preprocessing, Fingerprint image postprocessing. A few of the challenges presented in an earlier are, consequently addressed, in this paper. The proposed algorithm is able to enhance the fingerprint image and also extracting true minutiae.

  11. Supercritical solvent coal extraction

    Science.gov (United States)

    Compton, L. E. (Inventor)

    1984-01-01

    Yields of soluble organic extract are increased up to about 50% by the supercritical extraction of particulate coal at a temperature below the polymerization temperature for coal extract fragments (450 C.) and a pressure from 500 psig to 5,000 psig by the conjoint use of a solvent mixture containing a low volatility, high critical temperature coal dissolution catalyst such as phenanthrene and a high volatility, low critical temperature solvent such as toluene.

  12. Extractant Design by Covalency

    Energy Technology Data Exchange (ETDEWEB)

    Gaunt, Andrew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olson, Angela Christine [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kozimor, Stosh Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cross, Justin Neil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Batista, Enrique Ricardo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Macor, Joe [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Illinois, Urbana-Champaign, IL (United States); Peterman, Dean R. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Grimes, Travis [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-01-21

    This project aims to provide an electronic structure-to-function understanding of extractants for actinide selective separation processes. The research entails a multi-disciplinary approach that integrates chemical syntheses, structural determination, K-edge X-ray Absorption Spectroscopy (XAS), and Density Functional Theory (DFT) calculations. In FY15, the project reached the final stage of testing the extraction performance of a new ligand design and preparing an americium-extractant complex for analysis.

  13. Enhancing radiative energy transfer through thermal extraction

    Directory of Open Access Journals (Sweden)

    Tan Yixuan

    2016-06-01

    Full Text Available Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a. In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics.

  14. Parallel Feature Extraction System

    Institute of Scientific and Technical Information of China (English)

    MAHuimin; WANGYan

    2003-01-01

    Very high speed image processing is needed in some application specially for weapon. In this paper, a high speed image feature extraction system with parallel structure was implemented by Complex programmable logic device (CPLD), and it can realize image feature extraction in several microseconds almost with no delay. This system design is presented by an application instance of flying plane, whose infrared image includes two kinds of feature: geometric shape feature in the binary image and temperature-feature in the gray image. Accordingly the feature extraction is taken on the two kind features. Edge and area are two most important features of the image. Angle often exists in the connection of the different parts of the target's image, which indicates that one area ends and the other area begins. The three key features can form the whole presentation of an image. So this parallel feature extraction system includes three processing modules: edge extraction, angle extraction and area extraction. The parallel structure is realized by a group of processors, every detector is followed by one route of processor, every route has the same circuit form, and works together at the same time controlled by a set of clock to realize feature extraction. The extraction system has simple structure, small volume, high speed, and better stability against noise. It can be used in the war field recognition system.

  15. Extraction of polyphenols

    Directory of Open Access Journals (Sweden)

    Loucif Seiad L.

    2013-07-01

    Full Text Available The aim of the study is to investigate the influence of certain parameters on efficiency of the extraction of polyphenols from an Algerian tree (Pinus Halepensis Mill. Extraction was conducted in a stirred closed extractor. Our study was conducted to optimize the extraction conditions for total phenolic contents (TPC using Folin Ciocalteu method. A response surface methodology (RSM was launched to investigate the influence of process variables on extraction followed by a composite design (CD approach. The statistical analysis revealed that the optimized conditions were for a temperature of 45°C and for the smallest particles.

  16. Optical bistability controlling light with light

    CERN Document Server

    Gibbs, Hyatt

    1985-01-01

    Optical Bistability: Controlling Light with Light focuses on optical bistability in nonlinear optical systems. Emphasis is on passive (non-laser) systems that exhibit reversible bistability with input intensity as the hysteresis variable, along with the physics and the potential applications of such systems for nonlinear optical signal processing. This book consists of seven chapters and begins with a historical overview of optical bistability in lasers and passive systems. The next chapter describes steady-state theories of optical bistability, including the Bonifacio-Lugiato model, as we

  17. Traffic Light Options

    DEFF Research Database (Denmark)

    Jørgensen, Peter Løchte

    This paper introduces, prices, and analyzes traffic light options. The traffic light option is an innovative structured OTC derivative developed independently by several London-based investment banks to suit the needs of Danish life and pension (L&P) companies, which must comply with the traffic...... light solvency stress test system introduced by the Danish Financial Supervisory Authority (DFSA) in June 2001. This monitoring system requires L&P companies to submit regular reports documenting the sensitivity of the companies' base capital to certain pre-defined market shocks - the red and yellow...... light scenarios. These stress scenarios entail drops in interest rates as well as in stock prices, and traffic light options are thus designed to pay off and preserve sufficient capital when interest rates and stock prices fall simultaneously. Sweden's FSA implemented a traffic light system in January...

  18. Framing Light Rail Projects

    DEFF Research Database (Denmark)

    Olesen, Mette

    2014-01-01

    In Europe, there has been a strong political will to implement light rail. This article contributes to the knowledge concerning policies around light rail by analysing how local actors frame light rail projects and which rationalities and arguments are present in this decision-making process....... The article draws on the socio-technical approach to mobilities studies in order to reassemble the decision-making process in three European cases: Bergen, Angers, and Bern. This article provides insights into the political, discursive and material production of light rail mobilities in a European context....... It identifies the planning rationales behind the systems and the policies that have been supportive of this light rail vision. Finally, the article identifies the practical challenges and potentials that have been connected to the different local frames of light rail mobility which can be used in future...

  19. Light metal production

    Science.gov (United States)

    Fan, Qinbai

    2016-04-19

    An electrochemical process for the production of light metals, particularly aluminum. Such a process involves contacting a light metal source material with an inorganic acid to form a solution containing the light metal ions in high concentration. The solution is fed to an electrochemical reactor assembly having an anode side containing an anode and a cathode side containing a cathode, with anode side and the cathode side separated by a bipolar membrane, with the solution being fed to the anode side. Light metal ions are electrochemically transferred through the bipolar membrane to the cathode side. The process further involves reducing the light metal ions to light metal powder. An associated processing system is also provided.

  20. 3D light robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin; Villangca, Mark Jayson

    2016-01-01

    As celebrated by the Nobel Prize 2014 in Chemistry light-based technologies can now overcome the diffraction barrier for imaging with nanoscopic resolution by so-called super-resolution microscopy1. However, interactive investigations coupled with advanced imaging modalities at these small scale...... research discipline that could potentially be able to offer the full packet needed for true "active nanoscopy" by use of so-called light-driven micro-robotics or Light Robotics in short....

  1. 3D light robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin; Villangca, Mark Jayson;

    2016-01-01

    As celebrated by the Nobel Prize 2014 in Chemistry light-based technologies can now overcome the diffraction barrier for imaging with nanoscopic resolution by so-called super-resolution microscopy1. However, interactive investigations coupled with advanced imaging modalities at these small scale...... research discipline that could potentially be able to offer the full packet needed for true "active nanoscopy" by use of so-called light-driven micro-robotics or Light Robotics in short....

  2. High efficiency incandescent lighting

    Science.gov (United States)

    Bermel, Peter; Ilic, Ognjen; Chan, Walker R.; Musabeyoglu, Ahmet; Cukierman, Aviv Ruben; Harradon, Michael Robert; Celanovic, Ivan; Soljacic, Marin

    2014-09-02

    Incandescent lighting structure. The structure includes a thermal emitter that can, but does not have to, include a first photonic crystal on its surface to tailor thermal emission coupled to, in a high-view-factor geometry, a second photonic filter selected to reflect infrared radiation back to the emitter while passing visible light. This structure is highly efficient as compared to standard incandescent light bulbs.

  3. Berkeley Lighting Cone

    Energy Technology Data Exchange (ETDEWEB)

    Lask, Kathleen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gadgil, Ashok [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-24

    A lighting cone is a simple metal cone placed on the fuel bed of a stove during ignition to act as a chimney, increasing the draft through the fuel bed. Many stoves tend to be difficult to light due to poor draft through the fuel bed, so lighting cones are used in various parts of the world as an inexpensive accessory to help with ignition.

  4. Status and Future of High-Power Light-Emitting Diodes for Solid-State Lighting

    Science.gov (United States)

    Krames, Michael R.; Shchekin, Oleg B.; Mueller-Mach, Regina; Mueller, Gerd O.; Zhou, Ling; Harbers, Gerard; Craford, M. George

    2007-06-01

    Status and future outlook of III-V compound semiconductor visible-spectrum light-emitting diodes (LEDs) are presented. Light extraction techniques are reviewed and extraction efficiencies are quantified in the 60%+ (AlGaInP) and ~80% (InGaN) regimes for state-of-the-art devices. The phosphor-based white LED concept is reviewed and recent performance discussed, showing that high-power white LEDs now approach the 100-lm/W regime. Devices employing multiple phosphors for “warm” white color temperatures (~3000 4000 K) and high color rendering (CRI > 80), which provide properties critical for many illumination applications, are discussed. Recent developments in chip design, packaging, and high current performance lead to very high luminance devices (~50 Mcd/m2 white at 1 A forward current in 1 x 1 mm2 chip) that are suitable for application to automotive forward lighting. A prognosis for future LED performance levels is considered given further improvements in internal quantum efficiency, which to date lag achievements in light extraction efficiency for InGaN LEDs.

  5. Nanoengineering for solid-state lighting.

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, E. Fred (Rensselaer Polytechnic Institute,Troy, NY); Koleske, Daniel David; Wetzel, Christian (Rensselaer Polytechnic Institute,Troy, NY); Lee, Stephen Roger; Missert, Nancy A.; Lin, Shawn-Yu (Rensselaer Polytechnic Institute,Troy, NY); Crawford, Mary Hagerott; Fischer, Arthur Joseph

    2009-09-01

    This report summarizes results from a 3-year Laboratory Directed Research and Development project performed in collaboration with researchers at Rensselaer Polytechnic Institute. Our collaborative effort was supported by Sandia's National Institute for Nanoengineering and focused on the study and application of nanoscience and nanoengineering concepts to improve the efficiency of semiconductor light-emitting diodes for solid-state lighting applications. The project explored LED efficiency advances with two primary thrusts: (1) the study of nanoscale InGaN materials properties, particularly nanoscale crystalline defects, and their impact on internal quantum efficiency, and (2) nanoscale engineering of dielectric and metal materials and integration with LED heterostructures for enhanced light extraction efficiency.

  6. Exhaustive extraction of peptides by electromembrane extraction

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2015-01-01

    device. Mass transfer of peptides across the SLM was enhanced by complex formation with the negatively charged DEHP. The composition of the SLM and the extraction voltage were important factors influencing recoveries and current with the EME system. 1-nonanol diluted with 2-decanone (1:1 v/v) containing...

  7. Red light walking, transportation time and attitudes in crossing with intelligent green light for pedestrians

    DEFF Research Database (Denmark)

    Tønning, Charlotte; Agerholm, Niels; Andersen, Camilla Sloth

    Due to increased traffic, traffic management has to work more efficient than required earlier. One of the tools is Intelligent management of green light for pedestrians. It means that green light for pedestrians is dynamically suited to the actual flow and that pedestrian signal shifts to red prior...... registration, 72+53 interviewed persons, and what will be extracted from the literature review. Based on the collected data, it will be studied, if the share of red light walking will be reduced. Also, the transportation time including any waiting time will be calculated for the two periods. Furthermore......, the attitude and experiences with this traffic signals will be measured. It is the hypotheses that red light walking will be reduced and that the overall transportation time for pedestrians will be reduced due to a more applicable and dynamic traffic signal system. Likewise, it is expected that the pedestrian...

  8. Dissecting a Light Echo

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Click on image for audio animation This animation illustrates how a light echo works, and how an optical illusion of material moving outward is created. A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The animation starts by showing the explosion of a star, which results in a flash of light that moves outward in all directions. The direction of our line of sight from Earth is indicated by the blue arrow. When the light flash reaches surrounding dust, shown here as three dark clouds, the dust is heated up, creating infrared light that begins to travel toward Earth (indicated by the red arrows). Dust closest to the explosion lights up first, while the explosion's shock wave takes longer to reach more distant material. This results in light from different parts of the cloud reaching Earth at different times, creating the illusion of motion over time. As the animation shows, the inclination of the cloud toward our line of sight can result in the material seeming to move both away from and toward the central star.

  9. Light and Sound

    CERN Document Server

    Karam, P Andrew

    2010-01-01

    Our world is largely defined by what we see and hear-but our uses for light and sound go far beyond simply seeing a photo or hearing a song. A concentrated beam of light, lasers are powerful tools used in industry, research, and medicine, as well as in everyday electronics like DVD and CD players. Ultrasound, sound emitted at a high frequency, helps create images of a developing baby, cleans teeth, and much more. Light and Sound teaches how light and sound work, how they are used in our day-to-day lives, and how they can be used to learn about the universe at large.

  10. Occlusion, transparency, and lightness.

    Science.gov (United States)

    Albert, Marc K

    2007-11-01

    The lightness of a visual surface is its perceived achromatic reflectance [Adelson, E. H., (2000). Lightness perception and lightness illusions. In M. Gazzaniga (Ed.), The new cognitive neuroscience (2nd ed.) (pp. 339-351) Berlin: Springer; Gilchrist, A. (1999). Lightness perception. In R. W. F. Keil (Ed.), MIT encyclopedia of cognitive science (pp. 471-472). Cambridge: MIT press]. Lightness ranges from black, through various shades of grey, up to white. Anderson and Winawer [Anderson, B., Winawer, J. (2005). Image segmentation and lightness perception. Nature, 434, 79-83] suggested that perceptual decomposition of image luminance into multiple sources in different layers (e.g., perceptual transparency) is critical to the their lightness illusions. However, I show that simple perceptual occlusion evoked by T-junctions will work as well, suggesting that perceptual scission of luminance into multiple layers is unnecessary for such effects. I argue that the lightness illusions presented by Anderson and Winawer involve fundamentally different mechanisms than previously studied lightness illusions, including those involving perceptual transparency.

  11. Theodolite Ring Lights

    Science.gov (United States)

    Clark, David

    2006-01-01

    Theodolite ring lights have been invented to ease a difficulty encountered in the well-established optical-metrology practice of using highly reflective spherical tooling balls as position references. A theodolite ring light produces a more easily visible reflection and eliminates the need for an autocollimating device. A theodolite ring light is a very bright light source that is well centered on the optical axis of the instrument. It can be fabricated, easily and inexpensively, for use on a theodolite or telescope of any diameter.

  12. Quantum states of light

    CERN Document Server

    Furusawa, Akira

    2015-01-01

    This book explains what quantum states of light look like. Of special interest, a single photon state is explained by using a wave picture, showing that it corresponds to the complementarity of a quantum. Also explained is how light waves are created by photons, again corresponding to the complementarity of a quantum. The author shows how an optical wave is created by superposition of a "vacuum" and a single photon as a typical example. Moreover, squeezed states of light are explained as "longitudinal" waves of light and Schrödinger's cat states as macroscopic superposition states.

  13. Frustrated total internal reflection in organic light-emitting diodes employing sphere cavity embedded in polystyrene

    Science.gov (United States)

    Zhu, Peifen

    2016-02-01

    The light extraction efficiency of top-emitting organic light-emitting diodes (OLEDs) is numerically investigated employing the finite-difference time-domain method. The periodic nanostructures formed by embedding the sphere arrays in polystyrene (PS) are placed on top of OLED to frustrate the total internal reflection at the interface between OLED and free space. These nanostructures serve as an intermediate medium to extract the light out of OLED devices. Efficiently coupling both evanescent waves and propagation waves into spheres and subsequently extracting these light waves out of the sphere is key to achieving high extraction efficiency. By tuning the thickness of PS layer, both of the in-coupling efficiency and out-coupling efficiency are optimized for achieving high light extraction efficiency. Thicker PS layer results in higher in-coupling efficiency in sphere while the thinner PS layer leads to higher out-coupling efficiency. Thus the maximum light extraction is a trade-off between the in-coupling efficiency and out-coupling efficiency. The study shows that light extraction efficiency of 89% can be achieved by embedding 0.90 μm TiO2 sphere in 0.30 μm PS layer with optimized in-coupling efficiency, out-coupling efficiency and cavity effect.

  14. INTERMEDIATE-ENERGY LIGHT SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Corbett, William

    2002-11-25

    Increasingly, atomic scale information underlies scientific and technological progress in disciplines ranging from pharmaceutical development to materials synthesis to environmental remediation. While a variety of research tools are used to provide atomic scale information, synchrotron radiation has proved invaluable in this quest. The rapid growth of soft- and hard X-ray synchrotron light sources stands as stark testimony to the importance and utility of synchrotron radiation. Starting from just a handful of synchrotron light sources in the early 1970s, this burgeoning field now includes over 70 proposed, in-construction, or operating facilities in 23 countries on five continents. Along the way, synchrotron light facilities have evolved from small laboratories extracting light parasitically from storage rings designed for high-energy physics research to large, dedicated sources using the latest technology to produce extraordinarily bright photon beams. The basic layout of a multi-GeV storage ring light source employs periodic bending magnets to guide a charged particle beam around the storage ring. As the charged beam is accelerated in an arc, it produces a sweeping fan of synchrotron radiation that extends from the infrared part of the electromagnetic spectrum (<1 eV) to hard X rays (>20 keV). Quadrupole magnets keep the electrons tightly focused, and a radio-frequency acceleration system replenishes beam energy lost to radiation emission. To optimize the output radiation, a premium is placed on high current electron beams with small cross section and extreme position stability. Magnetic insertion devices are used to further enhance radiation output by a factor of 10 or more over bend magnet sources. The storage ring vacuum chamber includes exit ports to allow portions of the radiation fan to propagate down photon beam transport lines to optical systems and experimental stations. A typical storage ring features 10 or more such radiation ports. The photon beam

  15. Light source modeling for automotive lighting devices

    Science.gov (United States)

    Zerhau-Dreihoefer, Harald; Haack, Uwe; Weber, Thomas; Wendt, Dierk

    2002-08-01

    Automotive lighting devices generally have to meet high standards. For example to avoid discomfort glare for the oncoming traffic, luminous intensities of a low beam headlight must decrease by more than one order of magnitude within a fraction of a degree along the horizontal cutoff-line. At the same time, a comfortable homogeneous illumination of the road requires slowly varying luminous intensities below the cutoff line. All this has to be realized taking into account both, the legal requirements and the customer's stylistic specifications. In order to be able to simulate and optimize devices with a good optical performance different light source models are required. In the early stage of e.g. reflector development simple unstructured models allow a very fast development of the reflectors shape. On the other hand the final simulation of a complex headlamp or signal light requires a sophisticated model of the spectral luminance. In addition to theoretical models based on the light source's geometry, measured luminance data can also be used in the simulation and optimization process.

  16. Light + Light = Darkness : searching for exoplanets

    NARCIS (Netherlands)

    Hartmann, L.

    2002-01-01

    Arjan Mieremet, a doctorate student in the Optics section at Applied Physics, wants to extinguish stellar light in order to see the planets around it. The idea originated over twenty years ago, but so far nobody has managed to construct the necessary optical equipment. Mieremet tried, and soon ran i

  17. Light + Light = Darkness : searching for exoplanets

    NARCIS (Netherlands)

    Hartmann, L.

    2002-01-01

    Arjan Mieremet, a doctorate student in the Optics section at Applied Physics, wants to extinguish stellar light in order to see the planets around it. The idea originated over twenty years ago, but so far nobody has managed to construct the necessary optical equipment. Mieremet tried, and soon ran

  18. Natural light illumination system.

    Science.gov (United States)

    Whang, Allen Jong-Woei; Chen, Yi-Yung; Yang, Shu-Hua; Pan, Po-Hsuan; Chou, Kao-Hsu; Lee, Yu-Chi; Lee, Zong-Yi; Chen, Chi-An; Chen, Cheng-Nan

    2010-12-10

    In recent years, green energy has undergone a lot of development and has been the subject of many applications. Many research studies have focused on illumination with sunlight as a means of saving energy and creating healthy lighting. Natural light illumination systems have collecting, transmitting, and lighting elements. Today, most daylight collectors use dynamic concentrators; these include Sun tracking systems. However, this design is too expensive to be cost effective. To create a low-cost collector that can be easily installed on a large building, we have designed a static concentrator, which is prismatic and cascadable, to collect sunlight for indoor illumination. The transmission component uses a large number of optical fibers. Because optical fibers are expensive, this means that most of the cost for the system will be related to transmission. In this paper, we also use a prismatic structure to design an optical coupler for coupling n to 1. With the n-to-1 coupler, the number of optical fibers necessary can be greatly reduced. Although this new natural light illumination system can effectively guide collected sunlight and send it to the basement or to other indoor places for healthy lighting, previously there has been no way to manage the collected sunlight when lighting was not desired. To solve this problem, we have designed an optical switch and a beam splitter to control and separate the transmitted light. When replacing traditional sources, the lighting should have similar characteristics, such as intensity distribution and geometric parameters, to those of traditional artificial sources. We have designed, simulated, and optimized an illumination lightpipe with a dot pattern to redistribute the collected sunlight from the natural light illumination system such that it equals the qualities of a traditional lighting system. We also provide an active lighting module that provides lighting from the natural light illumination system or LED auxiliary

  19. Nano-electromembrane extraction

    DEFF Research Database (Denmark)

    Payán, María D Ramos; Li, Bin; Petersen, Nickolaj J.

    2013-01-01

    The present work has for the first time described nano-electromembrane extraction (nano-EME). In nano-EME, five basic drugs substances were extracted as model analytes from 200 μL acidified sample solution, through a supported liquid membrane (SLM) of 2-nitrophenyl octyl ether (NPOE......), and into approximately 8 nL phosphate buffer (pH 2.7) as acceptor phase. The driving force for the extraction was an electrical potential sustained over the SLM. The acceptor phase was located inside a fused silica capillary, and this capillary was also used for the final analysis of the acceptor phase by capillary...... as extraction selectivity. Compared with conventional EME, the acceptor phase volume in nano-EME was down-scaled by a factor of more than 1000. This resulted in a very high enrichment capacity. With loperamide as an example, an enrichment factor exceeding 500 was obtained in only 5 min of extraction...

  20. Light enhances learned fear.

    Science.gov (United States)

    Warthen, Daniel M; Wiltgen, Brian J; Provencio, Ignacio

    2011-08-16

    The ability to learn, remember, and respond to emotional events is a powerful survival strategy. However, dysregulated behavioral and physiological responses to these memories are maladaptive. To fully understand learned fear and the pathologies that arise during response malfunction we must reveal the environmental variables that influence learned fear responses. Light, a ubiquitous environmental feature, modulates cognition and anxiety. We hypothesized that light modulates responses to learned fear. Using tone-cued fear conditioning, we found that light enhances behavioral responses to learned fear in C57BL/6J mice. Mice in light freeze more in response to a conditioned cue than mice in darkness. The absence of significant freezing during a 2-wk habituation period and during intertrial intervals indicated that light specifically modulates freezing to the learned acoustic cue rather than the context of the experimental chamber. Repeating our assay in two photoreceptor mutant models, Pde6b(rd1/rd1) and Opn4(-/-) mice, revealed that light-dependent enhancement of conditioned fear is driven primarily by the rods and/or cones. By repeating our protocol with an altered lighting regimen, we found that lighting conditions acutely modulate responses when altered between conditioning and testing. This is manifested either as an enhancement of freezing when light is added during testing or as a depression of freezing when light is removed during testing. Acute enhancement, but not depression, requires both rod/cone- and melanopsin-dependent photoreception. Our results demonstrate a modulation by light of behavioral responses to learned fear.

  1. Measurement of Dynamic Light Scattering Intensity in Gels

    CERN Document Server

    Rochas, Cyrille

    2015-01-01

    In the scientific literature little attention has been given to the use of dynamic light scattering (DLS) as a tool for extracting the thermodynamic information contained in the absolute intensity of light scattered by gels. In this article we show that DLS yields reliable measurements of the intensity of light scattered by the thermodynamic fluctuations, not only in aqueous polymer solutions, but also in hydrogels. In hydrogels, light scattered by osmotic fluctuations is heterodyned by that from static or slowly varying inhomogeneities. The two components are separable owing to their different time scales, giving good experimental agreement with macroscopic measurements of the osmotic pressure. DLS measurements in gels are, however, tributary to depolarised light scattering from the network as well as to multiple light scattering. The paper examines these effects, as well as the instrumental corrections required to determine the osmotic modulus. For guest polymers trapped in a hydrogel the measured intensity...

  2. Multi-Projector Color Structured-Light Vision

    CERN Document Server

    Je, Changsoo; Lee, Sang Wook

    2015-01-01

    Research interest in rapid structured-light imaging has grown increasingly for the modeling of moving objects, and a number of methods have been suggested for the range capture in a single video frame. The imaging area of a 3D object using a single projector is restricted since the structured light is projected only onto a limited area of the object surface. Employing additional projectors to broaden the imaging area is a challenging problem since simultaneous projection of multiple patterns results in their superposition in the light-intersected areas and the recognition of original patterns is by no means trivial. This paper presents a novel method of multi-projector color structured-light vision based on projector-camera triangulation. By analyzing the behavior of superposed-light colors in a chromaticity domain, we show that the original light colors cannot be properly extracted by the conventional direct estimation. We disambiguate multiple projectors by multiplexing the orientations of projector pattern...

  3. Application of Surface Plasmonics for Semiconductor Light-Emitting Diodes

    DEFF Research Database (Denmark)

    Fadil, Ahmed

    This thesis addresses the lack of an efficient semiconductor light source at green emission colours. Considering InGaN based quantum-well (QW) light-emitters and light-emitting diodes (LEDs), various ways of applying surface plasmonics and nano-patterning to improve the efficiency, are investigated....... By placing metallic thin films or nanoparticles (NPs) in the near-field of QW light-emitters, it is possible to improve their internal quantum efficiency (IQE) through the Purcell enhancement effect. It has been a general understanding that in order to achieve surface plasmon (SP) coupling with QWs...... is presented to obtain light extraction efficiency (LEE) improvement through nano-patterning, and IQE improvement through SP-QW coupling. Considering the fabrication process aspect, dry-etching damage on the semiconductor light-emitters from the nano-patterning is also addressed. Different ion-damage treatment...

  4. Architectural Creation of Light

    DEFF Research Database (Denmark)

    Bülow, Katja

    2015-01-01

    Bidraget "Architectural Creation of Light" indgår sammen med 108 andre bidrag i bogen "You Say Light, I Think Shadow". Bogens indhold undersøger: "Hvad er lys". I dette bidrag besvares spørgsmålet gennem iagttagelser af arkitektstuderendes undersøgelser af lyset i deres arbejdsmodeller i...

  5. The visual light field

    NARCIS (Netherlands)

    Koenderink, J.J.; Pont, S.C.; Doorn, A.J. van; Kappers, A.M.L.; Todd, J.T.

    2007-01-01

    Human observers are sensitive to the ‘(physical) light field' in the sense that they have expectations of how a given object would appear if it were introduced in the scene in front of them at some arbitrary location. Thus the ‘visual light field' is defined even in the ‘empty space' between

  6. Light-emitting Diodes

    Science.gov (United States)

    Opel, Daniel R.; Hagstrom, Erika; Pace, Aaron K.; Sisto, Krisanne; Hirano-Ali, Stefanie A.; Desai, Shraddha

    2015-01-01

    Background: In the early 1990s, the biological significance of light-emitting diodes was realized. Since this discovery, various light sources have been investigated for their cutaneous effects. Study design: A Medline search was performed on light-emitting diode lights and their therapeutic effects between 1996 and 2010. Additionally, an open-label, investigator-blinded study was performed using a yellow light-emitting diode device to treat acne, rosacea, photoaging, alopecia areata, and androgenetic alopecia. Results: The authors identified several case-based reports, small case series, and a few randomized controlled trials evaluating the use of four different wavelengths of light-emitting diodes. These devices were classified as red, blue, yellow, or infrared, and covered a wide range of clinical applications. The 21 patients the authors treated had mixed results regarding patient satisfaction and pre- and post-treatment evaluation of improvement in clinical appearance. Conclusion: Review of the literature revealed that differing wavelengths of light-emitting diode devices have many beneficial effects, including wound healing, acne treatment, sunburn prevention, phototherapy for facial rhytides, and skin rejuvenation. The authors’ clinical experience with a specific yellow light-emitting diode device was mixed, depending on the condition being treated, and was likely influenced by the device parameters. PMID:26155326

  7. Enriching lighting design.

    Science.gov (United States)

    Brawley, Elizabeth C

    2009-01-01

    Good lighting is perhaps the most important and least understood element in designing healthcare environments. Both physically and mentally challenged individuals become more vulnerable and dependent on their environment to compensate for sensory impairments, including dimming eyesight, which interferes to some degree with daily activities as well as social and leisure activities - the things that provide emotional and social well-being. Too few building designs today result in lighting that meets the needs of these individuals, regardless of age. Typical lighting in most care environments is inadequate to meet lighting needs affecting both vision and the photobiological (non-visual) needs of synchronization of circadian rhythm, which impacts sleep and depression. Well-designed lighting is one of the most important design elements that will support an individual's ability to perform normal daily activities and decrease the level of disability associated with these impairments. Daylight contains the spectrum to which the circadian clock is most sensitive and provides higher light levels during the day. Easily accessible outdoor gardens encourage individuals outside, providing the necessary regular exposure to direct bright light that sunlight provides. The combination good interior lighting and regular daylight exposure contributes to regaining and maintaining an active and fulfilling lifestyle - greatly improving quality of life.

  8. The Traffic Light Challenge

    Science.gov (United States)

    Roman, Harry T.

    2014-01-01

    Traffic lights are an important part of the transportation infrastructure, regulating traffic flow and maintaining safety when crossing busy streets. When they go awry or become nonfunctional, a great deal of havoc and danger can be present. During power outages, the street lights go out all over the affected area. It would be good to be able to…

  9. Road lighting for safety.

    NARCIS (Netherlands)

    Schreuder, D.A.

    2000-01-01

    This book is aimed at broad readership, not especially at lighting experts. Lighting is presented as a system, as part of the public highway. Much attention is paid to subjects not greatly covered in the specialist literature, such as environmental aspects, traffic safety, crime prevention, and the

  10. 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.

  11. Lighting at computer workstations.

    Science.gov (United States)

    Osterhaus, Werner; Hemphälä, Hillevi; Nylén, Per

    2015-01-01

    The visual conditions for computer work are complex and include several factors that need to be well controlled. These factors include the lighting system, the design of the computer and screen itself, the screens position and orientation within the room, the surface reflectances and colours of the room, and the visualability of the worker. The objective was to review the literature (including standards) on lighting for computer work in an accessible summary. This contribution focuses on lighting for computer work, but the reader is reminded of the fact that lighting continuously interacts with the other factors mentioned above. The combined visual conditions shall enable the worker to see and perform the work task without causing unnecessary strain for the eyes or the other parts of the body. The main lighting-related factors in the visual environment to evaluate are: illuminance, luminance, direction of light, glare, correlated colour temperature of the light source (CCT), colour rendering of the light source, and the non-visual effects (such as non-visual flicker). A visual ergonomics checklist is presented as a guide to analyse the visual environment.

  12. Road lighting for safety.

    NARCIS (Netherlands)

    Schreuder, D.A.

    2000-01-01

    This book is aimed at broad readership, not especially at lighting experts. Lighting is presented as a system, as part of the public highway. Much attention is paid to subjects not greatly covered in the specialist literature, such as environmental aspects, traffic safety, crime prevention, and the

  13. Dynamic public lighting (DYNO)

    NARCIS (Netherlands)

    Kaptein, N.A.; Hogema, J.H.; Folles, E.

    1997-01-01

    In The Netherlands the concept of Dynamic Public Lighting (DYNO) has been introduced, which implies that road lighting is continuously adapted to the prevailing conditions, finding a balance between traffic safety and environment. For instance, in case of favourable weather conditions and low

  14. Traffic Light Detection

    DEFF Research Database (Denmark)

    Philipsen, Mark Philip; Jensen, Morten Bornø; Møgelmose, Andreas

    2015-01-01

    database is collected based on footage from US roads. The database consists of both test and training data, totaling 46,418 frames and 112,971 annotated traffic lights, captured in continuous sequences under a varying light and weather conditions. The learning based detector achieves an AUC of 0.4 and 0...

  15. Dynamic lighting design

    DEFF Research Database (Denmark)

    Linnebjerg, Sofie

    and under various weather conditions, creating a multitude of light settings. Humans live in interaction with this dynamic light and consider it as a natural part of our world [Mathiasen, 2015]. Furthermore, it has by the recent discovery of intrinsically photosensitive retinal ganglion cells in 2002...

  16. Light in complex dielectrics

    NARCIS (Netherlands)

    Schuurmans, F.J.P.

    1999-01-01

    In this thesis the properties of light in complex dielectrics are described, with the two general topics of "modification of spontaneous emission" and "Anderson localization of light". The first part focuses on the spontaneous emission rate of an excited atom in a dielectric host with variable refra

  17. Serum Free Light Chains

    Science.gov (United States)

    ... or of one of its component parts – a kappa or lambda light chain, or rarely, a heavy chain. Traditionally, plasma cell ... protein (M-protein) production and to calculate a kappa/lambda free light chain ratio. If the protein electrophoresis test is abnormal, ...

  18. 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.

  19. Architectural Creation of Light

    DEFF Research Database (Denmark)

    Bülow, Katja

    2015-01-01

    Bidraget "Architectural Creation of Light" indgår sammen med 108 andre bidrag i bogen "You Say Light, I Think Shadow". Bogens indhold undersøger: "Hvad er lys". I dette bidrag besvares spørgsmålet gennem iagttagelser af arkitektstuderendes undersøgelser af lyset i deres arbejdsmodeller i...

  20. Autonomous photovoltaic lighting system

    OpenAIRE

    Ahmed A. A. Hafez; Montesinos Miracle, Daniel; Sudrià Andreu, Antoni

    2012-01-01

    This paper introduces a comparison between the conventional and Photovoltaic (PV) lighting systems. A simple sizing procedure for a PV stand-alone system was advised. The paper also proposes a novel PV lighting system. The proposed system is simple, compact and reliable. The system operation was investigated by thoroughly mathematical and simulation work.

  1. Dynamic public lighting (DYNO)

    NARCIS (Netherlands)

    Kaptein, N.A.; Hogema, J.H.; Folles, E.

    1997-01-01

    In The Netherlands the concept of Dynamic Public Lighting (DYNO) has been introduced, which implies that road lighting is continuously adapted to the prevailing conditions, finding a balance between traffic safety and environment. For instance, in case of favourable weather conditions and low traffi

  2. Light and sound

    Institute of Scientific and Technical Information of China (English)

    王佩夫

    2002-01-01

    Light travels at a speed which is about a million times faster than the speed of sound.In one second,light travels about 300,000 km,but sound travels only 314m,you can get some idea of this difference(区别) by watching the start of a race.

  3. Dynamic public lighting (DYNO)

    NARCIS (Netherlands)

    Kaptein, N.A.; Hogema, J.H.; Folles, E.

    1997-01-01

    In The Netherlands the concept of Dynamic Public Lighting (DYNO) has been introduced, which implies that road lighting is continuously adapted to the prevailing conditions, finding a balance between traffic safety and environment. For instance, in case of favourable weather conditions and low traffi

  4. Flip-chip light emitting diode with resonant optical microcavity

    Science.gov (United States)

    Gee, James M.; Bogart, Katherine H.A.; Fischer, Arthur J.

    2005-11-29

    A flip-chip light emitting diode with enhanced efficiency. The device structure employs a microcavity structure in a flip-chip configuration. The microcavity enhances the light emission in vertical modes, which are readily extracted from the device. Most of the rest of the light is emitted into waveguided lateral modes. Flip-chip configuration is advantageous for light emitting diodes (LEDs) grown on dielectric substrates (e.g., gallium nitride LEDs grown on sapphire substrates) in general due to better thermal dissipation and lower series resistance. Flip-chip configuration is advantageous for microcavity LEDs in particular because (a) one of the reflectors is a high-reflectivity metal ohmic contact that is already part of the flip-chip configuration, and (b) current conduction is only required through a single distributed Bragg reflector. Some of the waveguided lateral modes can also be extracted with angled sidewalls used for the interdigitated contacts in the flip-chip configuration.

  5. Light Beam Generation

    DEFF Research Database (Denmark)

    2007-01-01

    The invention relates to a method and a system for synthesizing a set of controllable light beams by provision of a system for synthesizing a set of light beams, comprising a spatially modulated light source for generation of electromagnetic radiation with a set of replicas of a predetermined......(x-xs, y-ys), a Fourier transforming lens for Fourier transforming the electromagnetic radiation, a first spatial light modulator for phase shifting the Fourier transformed electromagnetic radiation with the phase -F(u, v) of S*, S* is the complex conjugate of the Fourier transformed symbol s, a Fourier...... transforming lens for Inverse Fourier transforming the spatially modulated radiation, whereby a set of light beams are formed propagating through the inverse Fourier plane (x', y') at desired positions (x's, y's), and a controller for controlling the position of a replica of the symbol, s, for movement...

  6. Light dispersion in space

    Science.gov (United States)

    Barbosa, L. C.

    2015-09-01

    Considering an idea of F. Arago in 1853 regarding light dispersion through the light ether in the interstellar space, this paper presents a new idea on an alternative interpretation of the cosmological red shift of the galaxies in the universe. The model is based on an analogy with the temporal material dispersion that occurs with light in the optical fiber core. Since intergalactic space is transparent, according to the model, this phenomenon is related to the gravitational potential existing in the whole space. Thus, it is possible to find a new interpretation to Hubble's constant. In space, light undergoes a dispersion process in its path, which is interpreted by a red shift equation of the type Δz = HL, since H = (d2n/dλ2 Δv Δλ), where H means the Hubble constant, n is the refractive index of the intergalactic space, Δλ is the spectral width of the extragalactic source, and Δv is the variation of the speed of light caused by the gravitational potential. We observe that this "constant" is governed by three new parameters. Light traveling the intergalactic space undergoes red shift due to this mechanism, while light amplitude decreases with time, and the wavelength always increases, thus producing the same type of behavior given by Hubble's Law. It can be demonstrated that the dark matter phenomenon is produced by the apparent speed of light of the stars on the periphery of the galaxies, without the existence of dark energy. Based on this new idea, the model of the universe is static, lacking expansion. Other phenomena may be interpreted based on this new model of the universe. We have what we call temporal gravitational dispersion of light in space produced by the variations of the speed of light, due to the presence of the gravitational potential in the whole space.

  7. Light environment and pigment composition of Megaceros pellucidus

    Directory of Open Access Journals (Sweden)

    Roger L. S. Watkins

    2011-06-01

    Full Text Available The hornwort Megaceros pellucidus occupies wet, heavily shaded sites. In four sites in thecentral North Island of New Zealand the maximum photon flux density (PFD was always less than 10μmol m-2 s-1. The PFD varied weakly during the day depending exponentially on the PFD of full sunlight.Light reflected from surface water late in the day transiently doubled the mid-day maximum PFD.Sunflecks had little impact on the site PFD consistent with the exponential relationship between the PFDsmeasured at the site and canopy. Plants from low light conditions (0.2 μmol m-2 s-1 had the samecarotenoid content as plants from higher light conditions (6.9 μmol m-2 s-1, but the chlorophyll contentof high light plants was approximately twice that of low light plants. The chlorophyll a/b ratio was thesame for plants from low and high light conditions. Spectra of acetone-extracts of M. pellucidus thallusfrom low light grown plants showed an absorbance band at about 340 nm that was not apparent inspectra of extracts from plants grown in high light conditions.

  8. Pulsed-Light Inactivation of Food-Related Microorganisms

    OpenAIRE

    N.J. Rowan; MacGregor, S. J.; Anderson, J. G.; Fouracre, R. A.; McIlvaney, L.; Farish, O.

    1999-01-01

    The effects of high-intensity pulsed-light emissions of high or low UV content on the survival of predetermined populations of Listeria monocytogenes, Escherichia coli, Salmonella enteritidis, Pseudomonas aeruginosa, Bacillus cereus, and Staphylococcus aureus were investigated. Bacterial cultures were seeded separately on the surface of tryptone soya-yeast extract agar and were reduced by up to 2 or 6 log10 orders with 200 light pulses (pulse duration, ∼100 ns) of low or high UV content, resp...

  9. Extracting the chiral anomaly from gamma pi --> pi pi

    CERN Document Server

    Hoferichter, Martin; Sakkas, Dimitrios

    2012-01-01

    We derive dispersive representations for the anomalous process gamma pi --> pi pi with the pi pi P-wave phase shift as input. We investigate how in this framework the chiral anomaly can be extracted from a cross-section measurement using all data up to 1 GeV, and discuss the importance of a precise representation of the gamma pi --> pi pi amplitude for the hadronic light-by-light contribution to the anomalous magnetic moment of the muon.

  10. Multimedia Information Extraction

    CERN Document Server

    Maybury, Mark T

    2012-01-01

    The advent of increasingly large consumer collections of audio (e.g., iTunes), imagery (e.g., Flickr), and video (e.g., YouTube) is driving a need not only for multimedia retrieval but also information extraction from and across media. Furthermore, industrial and government collections fuel requirements for stock media access, media preservation, broadcast news retrieval, identity management, and video surveillance.  While significant advances have been made in language processing for information extraction from unstructured multilingual text and extraction of objects from imagery and vid

  11. Face recognition at mesopic light levels and various light spectra

    NARCIS (Netherlands)

    Alferdinck, J.W.A.M.; Hogervorst, M.A.

    2013-01-01

    Light sources that are optimized for mesopic vision contain a relatively high amount of bluish light (high S/P-ratio) and are therefore effective for peripheral visual tasks at mesopic light levels. Since the spectra of these light sources differ strongly from the common public lighting there were d

  12. Light water reactor safety

    CERN Document Server

    Pershagen, B

    2013-01-01

    This book describes the principles and practices of reactor safety as applied to the design, regulation and operation of light water reactors, combining a historical approach with an up-to-date account of the safety, technology and operating experience of both pressurized water reactors and boiling water reactors. The introductory chapters set out the basic facts upon which the safety of light water reactors depend. The central section is devoted to the methods and results of safety analysis. The accidents at Three Mile Island and Chernobyl are reviewed and their implications for light wate

  13. Green Light Pulse Oximeter

    Energy Technology Data Exchange (ETDEWEB)

    Scharf, John Edward (Oldsmar, FL)

    1998-11-03

    A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

  14. CARICA PAPAYA EXTRACTS

    African Journals Online (AJOL)

    DR. AMINU

    Powdered leaves of Carica papaya (L.) were extracted with ethanol and partitioned in chloroform and distilled .... employed in this research is important in determining whether the ... Screening of higher plants reputed as pesticides using brine ...

  15. Silicon nanocrystal-based photonic crystal slabs with broadband and efficient directional light emission.

    Science.gov (United States)

    Ondič, L; Varga, M; Pelant, I; Valenta, J; Kromka, A; Elliman, R G

    2017-07-18

    Light extraction from a thin planar layer can be increased by introducing a two-dimensional periodic pattern on its surface. This structure, the so-called photonic crystal (PhC) slab, then not only enhances the extraction efficiency of light but can direct the extracted emission into desired angles. Careful design of the structures is important in order to have a spectral overlap of the emission with extraction (leaky) modes. We show that by fabricating PhC slabs with optimized dimensions from silicon nanocrystals (SiNCs) active layers, the extraction efficiency of vertical light emission from SiNCs at a particular wavelength can be enhanced ∼ 11 times compared to that of uncorrugated SiNCs-rich layer. More importantly, increased light emission can be obtained in a broad spectral range and, simultaneously, the extracted light can stay confined within relatively narrow angle around the normal to the sample plane. We demonstrate experimentally and theoretically that the physical origin of the enhancement is such that light originating from SiNCs first couples to leaky modes of the PhCs and is then efficiently extracted into the surrounding.

  16. Fingerprint Feature Extraction Algorithm

    OpenAIRE

    Mehala. G

    2014-01-01

    The goal of this paper is to design an efficient Fingerprint Feature Extraction (FFE) algorithm to extract the fingerprint features for Automatic Fingerprint Identification Systems (AFIS). FFE algorithm, consists of two major subdivisions, Fingerprint image preprocessing, Fingerprint image postprocessing. A few of the challenges presented in an earlier are, consequently addressed, in this paper. The proposed algorithm is able to enhance the fingerprint image and also extractin...

  17. Painful Bile Extraction Methods

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    It was only in the past 20 years that countries in Asia began to search for an alternative to protect moon bears from being killed for their bile and other body parts. In the early 1980s, a new method of extracting bile from living bears was developed in North Korea. In 1983, Chinese scientists imported this technique from North Korea. According to the Animals Asia Foundation, the most original method of bile extraction is to embed a latex catheter, a narrow rubber

  18. Asymmetric extractions in orthodontics

    Directory of Open Access Journals (Sweden)

    Camilo Aquino Melgaço

    2012-04-01

    Full Text Available INTRODUCTION: Extraction decisions are extremely important in during treatment planning. In addition to the extraction decision orthodontists have to choose what tooth should be extracted for the best solution of the problem and the esthetic/functional benefit of the patient. OBJECTIVE: This article aims at reviewing the literature relating the advantages, disadvantages and clinical implications of asymmetric extractions to orthodontics. METHODS: Keywords were selected in English and Portuguese and the EndNote 9 program was used for data base search in PubMed, Web of Science (WSc and LILACS. The selected articles were case reports, original articles and prospective or retrospective case-control studies concerning asymmetrical extractions of permanent teeth for the treatment of malocclusions. CONCLUSION: According to the literature reviewed asymmetric extractions can make some specific treatment mechanics easier. Cases finished with first permanent molars in Class II or III relationship in one or both sides seem not to cause esthetic or functional problems. However, diagnosis knowledge and mechanics control are essential for treatment success.

  19. Driver’s Fatigue Detection Based on Yawning Extraction

    Directory of Open Access Journals (Sweden)

    Nawal Alioua

    2014-01-01

    a real danger on road since it reduces driver capacity to react and analyze information. In this paper we propose an efficient and nonintrusive system for monitoring driver fatigue using yawning extraction. The proposed scheme uses face extraction based support vector machine (SVM and a new approach for mouth detection, based on circular Hough transform (CHT, applied on mouth extracted regions. Our system does not require any training data at any step or special cameras. Some experimental results showing system performance are reported. These experiments are applied over real video sequences acquired by low cost web camera and recorded in various lighting conditions.

  20. Liquid crystal light valves for slow light and applications

    Energy Technology Data Exchange (ETDEWEB)

    Residori, S; Bortolozzo, U [INLN, CNRS, University de Nice Sophia-Antipolis, 1361 route des Lucioles, 06560 Valbonne (France); Huignard, J P, E-mail: jean-pierre.huignard@thalesgroup.co [Thales Research and Technology, RD 128 91767, Palaiseau Cedex (France)

    2010-02-01

    The large dispersive properties of wave mixing in liquid crystal light-valves allow obtaining fast and slow light with tunable group velocities. A slow light interferometer is shown by using this interaction.

  1. Light on curved backgrounds

    Science.gov (United States)

    Batic, D.; Nelson, S.; Nowakowski, M.

    2015-05-01

    We consider the motion of light on different spacetime manifolds by calculating the deflection angle, lensing properties and by probing into the possibility of bound states. The metrics in which we examine the light motion include, among other items, a general relativistic dark matter metric, a dirty black hole, and a worm hole metric, the last two inspired by noncommutative geometry. The lensing in a holographic screen metric is discussed in detail. We study also the bending of light around naked singularities like, e.g., the Janis-Newman-Winicour metric and include other cases. A generic property of light behavior in these exotic metrics is pointed out. For the standard metric like the Schwarzschild and Schwarzschild-de Sitter cases, we improve the accuracy of the lensing results for the weak and strong regimes.

  2. Light on curved backgrounds

    CERN Document Server

    Batic, D; Nowakowski, M

    2014-01-01

    We consider the motion of light on different spacetime manifolds by calculating the deflection angle, lensing properties and by probing into the possibility of bound states. The metrics in which we examine the light motion include, among other, a general relativistic Dark Matter metric, a dirty Black Hole and a Worm Hole metric, the last two inspired by non-commutative geometry. The lensing in a Holographic Screen metric is discussed in detail. We study also the bending of light around naked singularities like, e.g., the Janis-Newman-Winicour metric and include other cases. A generic property of light behaviour in these exotic metrics is pointed out. For the standard metric like the Schwarzschild and Schwarzschild-de Sitter cases we improve the accuracy of the lensing results for the weak and strong regime.

  3. Thermoelectricity Light Sources

    Institute of Scientific and Technical Information of China (English)

    SHIYongji

    1997-01-01

    A thermoelectricity light source in a gaseous plasma discharge between two electrodes is described,one of which emits electrons thermoionically.The analytical model describing basic physical phenomena is developed.The results are excellent agreement with simulated test.

  4. Sustainable indoor lighting

    CERN Document Server

    Mercatelli, Luca; Farini, Alessandro

    2015-01-01

    Encompassing a thorough survey of the lighting techniques applied to internal illumination characterized by high efficiency, optimized color and architectural integration, a consolidated summary of the latest scientific, technical and architectural research is presented in order to give the reader an overview of the different themes with their interactions and mutual effects.   This book describes light principles, methodologies and realisations for indoor illumination at low consumption. Power efficiency, color characteristics and architectural aspects are analyzed in terms of their  practical application, with the interactions between scientific, technological and architectural features considered in order to supply a complete overview, which can be read both at technical level and at user level. Introducing photometric and radiometric quantities and laws, the book first discusses tests and measurements assessing lighting and color characteristics before examining in detail artificial light sources with p...

  5. Light shielding apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Richard Dean; Thom, Robert Anthony

    2017-10-10

    A light shielding apparatus for blocking light from reaching an electronic device, the light shielding apparatus including left and right support assemblies, a cross member, and an opaque shroud. The support assemblies each include primary support structure, a mounting element for removably connecting the apparatus to the electronic device, and a support member depending from the primary support structure for retaining the apparatus in an upright orientation. The cross member couples the left and right support assemblies together and spaces them apart according to the size and shape of the electronic device. The shroud may be removably and adjustably connectable to the left and right support assemblies and configured to take a cylindrical dome shape so as to form a central space covered from above. The opaque shroud prevents light from entering the central space and contacting sensitive elements of the electronic device.

  6. Light composite vector bosons

    CERN Document Server

    Kosower, David A.

    1993-01-01

    In gauge theories with slowly-running coupling constants, it may be possible for four-fermion operators to be nearly marginal. Such operators can possess asymptotically weak couplings, and can plausibly give rise to light composite vector mesons.

  7. Light, Matter, and Geometry

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall

    Interaction of light and matter produces the appearance of materials. To deal with the immense complexity of nature, light and matter is modelled at a macroscopic level in computer graphics. This work is the first to provide the link between the microscopic physical theories of light and matter...... of a material and determine the contents of the material. The book is in four parts. Part I provides the link between microscopic and macroscopic theories of light. Part II describes how to use the properties of microscopic particles to compute the macroscopic properties of materials. Part III illustrates...... that we can use geometrical models to handle the large number of variables which appear when we construct appearance models from microscopic theories. Finally, Part IV provides detailed appearance models for natural water, ice, and milk to demonstrate how the theory is applied....

  8. Modeling LED street lighting.

    Science.gov (United States)

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

    2014-07-10

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

  9. Polarized Light Corridor Demonstrations.

    Science.gov (United States)

    Davies, G. R.

    1990-01-01

    Eleven demonstrations of light polarization are presented. Each includes a brief description of the apparatus and the effect demonstrated. Illustrated are strain patterns, reflection, scattering, the Faraday Effect, interference, double refraction, the polarizing microscope, and optical activity. (CW)

  10. POLARIZED LIGHT IN PHYSIOTHERAPY

    National Research Council Canada - National Science Library

    L. D. Tondiy; O. L. Tondiy; I. V. Kas; O. V. Zemlyana; O. L. Zakrevska; V. O. Zhuravliev

    2015-01-01

    The data on polarized light (PS) - a new promising treatment, rehabilitation and prevention, which took its deserved place among the known therapeutic physical factors and may even compete with laser radiation of low and LED therapy...

  11. Light Detection And Ranging

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — LiDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  12. The wonders of light

    CERN Document Server

    García-Matos, Marta

    2015-01-01

    Discover the spectacular power of light with this visually stunning celebration of the multitude of ways in which light-based technology has shaped our society. Be inspired by state-of-the-art science: sixteen beautiful, straightforward chapters demonstrate the science behind the fascinating and surprising ways in which light can be harnessed and used, from displays, solar cells and the Internet to advanced quantum technologies. Be dazzled by brilliant color: dramatic design and radiant color illustrations bring cutting-edge science and groundbreaking innovations to life, clearly explaining the fundamental principles behind them. Be part of something bigger: published in association with the Institute of Photonic Sciences (ICFO) to celebrate the 2015 UNESCO International Year of Light, it is perfect for anyone interested in the frontiers of science, engineering or medicine, and in the phenomenal technological advances that have been made possible by human innovation.

  13. Cosmic Light EDU kit

    Science.gov (United States)

    Doran, Rosa

    2015-08-01

    In 2015 we celebrate the International Year of Light, a great opportunity to promote awareness about the importance of light coming from the Cosmos and what messages it is bringing to mankind. In parallel a unique moment to attract the attention of stakeholders on the dangers of light pollution and its impact in our lives and our pursuit of more knowledge. In this presentation I want to present one of the conrnerstones of IYL2015, a partnership between the Galileo Teacher Training Program, Universe Awareness and Globe at Night, the Cosmic Light EDU kit. The aim of this project is to assemble a core set of tools and resources representing our basic knowledge pilars about the Universe and simple means to preserve our night sky.

  14. Casimir light: a glimpse.

    OpenAIRE

    1993-01-01

    Light emission produced by the reversible collapse of a cavity in a dielectric medium is given an initial, simplified treatment. The agreement between planar and spherical shapes indicates the volume nature of the effect.

  15. Occupant Controlled Lighting

    DEFF Research Database (Denmark)

    Logadóttir, Ásta

    2011-01-01

    of adjustment. Firstly, there was preliminary laboratory study exploring the influence of daylight on occupant controlled dynamic lighting in a laboratory office environment. Secondly, there was non-daylit laboratory study on occupant preferences for illuminance, and thirdly a scale model study on occupant......The studies presented in this thesis explore opportunities and limitations of using the method of adjustment for occupant controlled lighting. The method of adjustment is studied with respect to occupant preferences and energy efficiency. The work presents three types of studies using the method...... preferences for correlated colour temperature (CCT). The results suggest that the method of adjustment, previously used in the lighting literature, is not adequate to generalize about occupant preferences for illuminance or CCT. Factors that influence occupants’ lighting preference when applying the method...

  16. Light Detection And Ranging

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — LiDAR (Light Detection and Ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  17. Enhancing radiative energy transfer through thermal extraction

    Science.gov (United States)

    Tan, Yixuan; Liu, Baoan; Shen, Sheng; Yu, Zongfu

    2016-06-01

    Thermal radiation plays an increasingly important role in many emerging energy technologies, such as thermophotovoltaics, passive radiative cooling and wearable cooling clothes [1]. One of the fundamental constraints in thermal radiation is the Stefan-Boltzmann law, which limits the maximum power of far-field radiation to P0 = σT4S, where σ is the Boltzmann constant, S and T are the area and the temperature of the emitter, respectively (Fig. 1a). In order to overcome this limit, it has been shown that near-field radiations could have an energy density that is orders of magnitude greater than the Stefan-Boltzmann law [2-7]. Unfortunately, such near-field radiation transfer is spatially confined and cannot carry radiative heat to the far field. Recently, a new concept of thermal extraction was proposed [8] to enhance far-field thermal emission, which, conceptually, operates on a principle similar to oil immersion lenses and light extraction in light-emitting diodes using solid immersion lens to increase light output [62].Thermal extraction allows a blackbody to radiate more energy to the far field than the apparent limit of the Stefan-Boltzmann law without breaking the second law of thermodynamics. Thermal extraction works by using a specially designed thermal extractor to convert and guide the near-field energy to the far field, as shown in Fig. 1b. The same blackbody as shown in Fig. 1a is placed closely below the thermal extractor with a spacing smaller than the thermal wavelength. The near-field coupling transfers radiative energy with a density greater than σT4. The thermal extractor, made from transparent and high-index or structured materials, does not emit or absorb any radiation. It transforms the near-field energy and sends it toward the far field. As a result, the total amount of far-field radiative heat dissipated by the same blackbody is greatly enhanced above SσT4, where S is the area of the emitter. This paper will review the progress in thermal

  18. Neutral Complex Extraction and Synergistic Extraction of Macrolide Antibiotics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the theory of reactive extraction, new solvent systems were developed to replace butylacetate for extraction of macrolide antibiotics (erythromycin, kitasamycin, spiramycin meleumycin etc.). A new neutral complex solvent extraction system, fatty alcohol-kerosene (marked by E1), was used for extraction of erythromycin, one of the macrolide antibiotics. The extraction equilibrium equation is obtained, and the extraction distribution is as follows The effects of several parameters on extraction equilibrium were investigated. Furthermore, a new synergistic extraction system (marked by E2) was developed, in which another solvent was used as synergistic agent to replace the diluent kerosene in the neutral complex extraction system. Based on these new extraction systems, an improved process for extraction of erythromycin was developed, showing remarkable advantages in technology and economics owing to its low solvent consumption of 3kg per billion unit compared with 9-10 for butylacetate. The recovery process of solvent from raffinate may be eliminated.

  19. Indoor Lighting Facilities

    Science.gov (United States)

    Matsushima, Koji; Saito, Yoshinori; Ichikawa, Shigenori; Kawauchi, Takao; Tanaka, Tsuneo; Hirano, Rika; Tazuke, Fuyuki

    According to the statistics by the Ministry of Land, Infrastructure and Transport, the total floor space of all building construction started was 188.87 million m2 (1.5% increase y/y), marking the fourth straight year of increase. Many large-scale buildings under construction in central Tokyo become fully occupied by tenants before completion. As for office buildings, it is required to develop comfortable and functional office spaces as working styles are becoming more and more diversified, and lighting is also an element of such functionalities. The total floor space of construction started for exhibition pavilions, multipurpose halls, conference halls and religious architectures decreased 11.1% against the previous year. This marked a decline for 10 consecutive years and the downward trend continues. In exhibition pavilions, the light radiation is measured and adjusted throughout the year so as not to damage the artworks by lighting. Hospitals, while providing higher quality medical services and enhancing the dwelling environment of patients, are expected to meet various restrictions and requirements, including the respect for privacy. Meanwhile, lighting designs for school classrooms tend to be homogeneous, yet new ideas are being promoted to strike a balance between the economical and functional aspects. The severe economic environment continues to be hampering the growth of theaters and halls in both the private and public sectors. Contrary to the downsizing trend of such facilities, additional installations of lighting equipment were conspicuous, and the adoption of high efficacy lighting appliances and intelligent function control circuits are becoming popular. In the category of stores/commercial facilities, the construction of complex facilities is a continuing trend. Indirect lighting, high luminance discharge lamps with excellent color rendition and LEDs are being effectively used in these facilities, together with the introduction of lighting designs

  20. Cauldron of Light

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] Click on image to view the animation In this animation, a seething cauldron of light appears to bubble and ooze around the remains of a giant star that astronomers have been watching tear itself apart for the last 300 years. This movie flips quickly between different observations taken over three years by NASA's Spitzer Space Telescope. Beginning in the center, the well-studied Cassiopeia A supernova remnant is shown. Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion. It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died. Panning outward, 'light echoes' create the illusion of motion in the clouds, as different areas of the material are lit up in succession by the light flash of the supernova. A light echo occurs when a star explodes, acting like a cosmic flashbulb. The light from this explosion zips through nearby dust clumps, illuminating and heating them up slightly. This brief period of warming causes them to glow in infrared, like a chain of Christmas bulbs lighting up one by one. The result is an optical illusion, in which the dust appears to be flying outward at the speed of light. In reality, the clouds are stationary, at least in the brief time over which these observations were taken. The inclination of the clouds cause some light echoes to appear to expand away from the supernova remnant, while others move towards it or boil in many directions with seeming turbulence.

  1. Painting with light

    DEFF Research Database (Denmark)

    Jensen, Niels Henrik

    The paper describes a method, where Photoshop are used for balancing the different light sources of a rendered CAD-model. The method shortens the work process considerably, and makes it easier to obtain a result of a high quality.......The paper describes a method, where Photoshop are used for balancing the different light sources of a rendered CAD-model. The method shortens the work process considerably, and makes it easier to obtain a result of a high quality....

  2. Light enhances learned fear

    OpenAIRE

    Warthen, Daniel M.; Wiltgen, Brian J.; Provencio, Ignacio

    2011-01-01

    The ability to learn, remember, and respond to emotional events is a powerful survival strategy. However, dysregulated behavioral and physiological responses to these memories are maladaptive. To fully understand learned fear and the pathologies that arise during response malfunction we must reveal the environmental variables that influence learned fear responses. Light, a ubiquitous environmental feature, modulates cognition and anxiety. We hypothesized that light modulates responses to lear...

  3. Light chain nephropathy

    Directory of Open Access Journals (Sweden)

    Sihem Darouich

    2015-01-01

    Full Text Available Light chain deposition disease (LCDD is characterized by the tissue deposition of monotypic immunoglobulin light chains of either kappa or lambda isotype. It is the archetypal systemic disease that is most frequently diagnosed on a kidney biopsy, although the deposits may involve several other organs. This brief review focuses on the clinicopathological features of LCDD-associated nephropathy with an emphasis on the diagnostic and therapeutic difficulties related to this elusive condition.

  4. Microfluidic evaporative light scattering detector coupled with capillary liquid chromatography and its application to Ginkgo biloba extract analysis%微流蒸发光散射检测器与毛细管液相色谱的联用及其在银杏叶提取物分析中的应用

    Institute of Scientific and Technical Information of China (English)

    赵卉; 王玉红; 刘芳; 王彦; 谷雪; 阎超

    2013-01-01

    将微流蒸发光散射检测器(μELSD)与毛细管液相色谱(cLC)联用,应用于中药银杏叶提取物及其分散片制剂的分离检测领域.首先对μELSD仪器参数进行优化.通过调节漂移管温度与载气流量,提高了分析物的响应,并减小了噪声.然后,搭建了cLC-μELSD分离检测平台,其相对常规LC可大大减小实验试剂消耗.流动相A为0.05%(体积分数,下同)三氟乙酸(TFA)水溶液,流动相B为含0.05% TFA的甲醇溶液.最优的洗脱梯度条件为:0 ~ 10 min,5%B ~ 25% B; 10~25 min,25%B ~38% B;25 ~35 min,38%B;35 ~ 40 min,38%B~42% B;40~55min,42%B ~50%B.银杏叶提取物和复杂中药制剂银杏叶提取物分散片都得到了较好的分离,并在其中鉴定到紫外波段几乎无吸收的重要内酯类活性成分白果内酯以及银杏内酯A、B和C.测定了不同厂家银杏叶提取物中萜类内酯洗脱时间的相对标准偏差,结果均不大于2.42%,表明该体系在目标物的分析上具有良好的重现性.实验证明所建立的cLC-ELSD体系在复杂中药体系的分离检测中有良好的应用性.%A novel separation system of microfluidic evaporative light scattering detector (μELSD) coupled with capillary liquid chromatography (cLC) was built and applied to the separation and detection of herbal medicine Ginkgo biloba extract and its disperse tablet formulation.Compared with the traditional HPLC,this μELSD-cLC system consumed much less sample and solvent.Some key parameters were optimized.It was found that the higher the evaporization temperature of the drift tube,the higher S/N could be achieved.The mobile phase A was 0.05% (v/v) trifiuoroacetic acid (TFA),and the mobile phase B was methanol containing 0.05% (v/v) TFA.The optimized gradient conditions were as follows:0-10 min,5% B-25% B; 10-25 min,25% B-38% B; 25-35 min,38% B; 35-40 min,38% B-42% B; 40-55min,42% B-50% B.The complex herbal medicine

  5. Opportunities and problems in determining proton and light nuclear radii

    Indian Academy of Sciences (India)

    N G Kelkar; M Nowakowski; D Bedoya Fierro

    2014-11-01

    We briefly review the so-called `proton puzzle’, i.e., the disagreement of the newly extracted value of the proton charge radius $r_p$ from muonic hydrogen spectroscopy with other extractions, its possible significance and related problems. After describing the conventional theory to extract the proton radius from atomic spectroscopy we focus on a novel consistent approach based on the Breit equation. With this new tool, we confirm that the radius has indeed become smaller compared to the value extracted from scattering experiments, but the existence of different theoretical approaches casts some doubt on the accuracy of the new value. Precision measurements in atomic physics do provide the opportunity to extract light nuclear radii but the accuracy is limited by the methods of incorporating the nuclear structure effects.

  6. Phase extraction based on sinusoidal extreme strip phase shifting method

    Science.gov (United States)

    Hui, Mei; Liu, Ming; Dong, Liquan; Liu, Xiaohua; Zhao, Yuejin

    2015-08-01

    Multiple synthetic aperture imaging can enlarge pupil diameter of optical systems, and increase system resolution. Multiple synthetic aperture imaging is a cutting-edge topic and research focus in recent years, which is prospectively widely applied in fields like astronomical observations and aerospace remote sensing. In order to achieve good imaging quality, synthetic aperture imaging system requires phase extraction of each sub-aperture and co-phasing of whole aperture. In the project, an in-depth study about basic principles and methods of segments phase extraction was done. The study includes: application of sinusoidal extreme strip light irradiation phase shift method to extract the central dividing line to get segment phase extraction information, and the use of interference measurement to get the aperture phase extraction calibration coefficients of spherical surface. Study about influence of sinusoidal extreme strip phase shift on phase extraction, and based on sinusoidal stripe phase shift from multiple linear light sources of the illumination reflected image, to carry out the phase shift error for inhibiting the effect in the phase extracted frame.

  7. Lighting Retrofitting: improving energy efficiency and lighting quality

    OpenAIRE

    2015-01-01

    In order to minimize energy consumption for lighting and increasing lighting quality in existing offices old lighting systems can be retrofitted with more efficient luminaires. Additional savings can be achieved by installing a lighting control system. Installation time and costs can be reduced by installing LED luminaires equipped with inbuilt lighting controls. In the case study six rooms were analysed: in two rooms the old lighting system has been retrofitted with LED luminaires with inbui...

  8. Extraction of bioactive compounds and free radical scavenging activity of purple basil (Ocimum basilicum L.) leaf extracts as affected by temperature and time

    OpenAIRE

    PEDRO,ALESSANDRA C.; FERNANDA MOREIRA; DANIEL GRANATO; ROSSO,NEIVA D.

    2016-01-01

    In the current study, response surface methodology (RSM) was used to assess the effects of extraction time and temperature on the content of bioactive compounds and antioxidant activity of purple basil leaf (Ocimum basilicum L.) extracts. The stability of anthocyanins in relation to temperature, light and copigmentation was also studied. The highest anthocyanin content was 67.40 mg/100 g extracted at 30 °C and 60 min. The degradation of anthocyanins with varying temperatures and in the presen...

  9. [Bright light therapy].

    Science.gov (United States)

    Poirrier, R; Cambron, L

    2007-01-01

    Bright light therapy is a treatment that emerged in the eighties of the last century. It can be used in different pathologies such as seasonal affective disorders, major depressions, and many disorders of the wake-sleep rhythm, whether they are of primary or secondary origin. Important progress made at the basic neuroscience levels, allows today a sound understanding of the bright light mode of action. Moreover, the main indications are now the subject of consensus reports and meta-analyses which show good levels of evidence-based medicine. Bright light therapy constitutes a first choice indication in seasonal affective disorder. It is also perfectly possible to prescribe bright light therapy in the major depression disorders. It has been demonstrated that the effect size is the same as with antidepressants of reference. It is admitted nowadays that bright light therapy may be at least, an adjunct to pharmacotherapy, in order to accelerate the antidepressant effect onset, or to prolong this effect after withdrawal of the drug. Bright light therapy can also be viewed as an alternative to the pharmacological approach especially when this one is impossible, not tolerated or not accepted by the patient. The contraindications are rare.

  10. Fifth generation light sources

    Science.gov (United States)

    Romaniuk, Ryszard S.

    2016-12-01

    Coherent light sources are one of the most fundamental research tools in biology, technology and in other areas. Synchrotron light source consists of a few basic parts: energy source - which is an electron beam accelerator, energy converter between electron and photon beams - which is an undulator, and photon user experimental lines. Each of these parts is separately a complex system, which is currently a subject to fast technological development. Future light sources of the fifth generation are based on completely new solutions of these fundamental parts, in comparison with the sources of the previous generations. Energy source is a new generation laser - plasma accelerator with electrical field in the area of multiple GV/m. A miniature undulator is tested in the MEMS technology from new materials. Classical light beam lines, vacuum, and difficult for management and beam distribution, change their meaning in the case of availability of miniature undulators positioned immediately at or even inside the experimental stations. After an introduction concerning the light sources of the previous generations, the article shows current research efforts on the mentioned key components of the fifth generation light sources. In some cases this is a continuation and modernization of the previous technologies, in the majority it is a brave endeavour to apply completely new technologies, like laser - plasma acceleration.

  11. Lightness and perceptual transparency.

    Science.gov (United States)

    Albert, Marc K

    2006-01-01

    To estimate intrinsic descriptors of objects in the environment, effective biological vision systems must 'discount' extrinsic image properties that arise from changes in viewing conditions. In particular, to estimate the reflectance of surfaces, human vision must discount, or 'take account of', likely differences in the illumination of surfaces between one image region and another. If human vision possesses any significant degree of lightness constancy, then we would expect a target perceived to be in low illumination to appear lighter than an identical target perceived to be in higher illumination. In this paper, I present lightness illusions that run directly counter to this expectation. I suggest that mid-level and higher-level factors such as image junction structure and perceived illumination and transparency, are ineffective for generating strong lightness illusions on their own, and that these factors are not 'stronger' than luminance contrast in determining lightness. I discuss the implications of these results for current models of lightness perception. I also suggest a statistical justification for the highest-luminance anchoring rule for lightness.

  12. Compressive light field sensing.

    Science.gov (United States)

    Babacan, S Derin; Ansorge, Reto; Luessi, Martin; Matarán, Pablo Ruiz; Molina, Rafael; Katsaggelos, Aggelos K

    2012-12-01

    We propose a novel design for light field image acquisition based on compressive sensing principles. By placing a randomly coded mask at the aperture of a camera, incoherent measurements of the light passing through different parts of the lens are encoded in the captured images. Each captured image is a random linear combination of different angular views of a scene. The encoded images are then used to recover the original light field image via a novel Bayesian reconstruction algorithm. Using the principles of compressive sensing, we show that light field images with a large number of angular views can be recovered from only a few acquisitions. Moreover, the proposed acquisition and recovery method provides light field images with high spatial resolution and signal-to-noise-ratio, and therefore is not affected by limitations common to existing light field camera designs. We present a prototype camera design based on the proposed framework by modifying a regular digital camera. Finally, we demonstrate the effectiveness of the proposed system using experimental results with both synthetic and real images.

  13. Enhanced light output from a nitride-based power chip of green light-emitting diodes with nano-rough surface using nanoimprint lithography.

    Science.gov (United States)

    Huang, H W; Lin, C H; Yu, C C; Lee, B D; Chiu, C H; Lai, C F; Kuo, H C; Leung, K M; Lu, T C; Wang, S C

    2008-05-07

    Enhanced light extraction from a GaN-based power chip (PC) of green light-emitting diodes (LEDs) with a rough p-GaN surface using nanoimprint lithography is presented. At a driving current of 350 mA and with a chip size of 1 mm × 1 mm packaged on transistor outline (TO)-cans, the light output power of the green PC LEDs with nano-rough p-GaN surface is enhanced by 48% when compared with the same device without a rough p-GaN surface. In addition, by examining the radiation patterns, the green PC LED with nano-rough p-GaN surface shows stronger light extraction with a wider view angle. These results offer promising potential to enhance the light output powers of commercial light-emitting devices by using the technique of nanoimprint lithography under suitable nanopattern design.

  14. Light Pollution and Wildlife

    Science.gov (United States)

    Duffek, J.

    2008-12-01

    for Educational Program IYA Dark Skies Education Session Fall American Geophysical Union San Francisco, December 15-19, 2008 Light Pollution and Wildlife This is a very exciting time to be a part of the mission to keep the nighttime skies natural. The International Year of Astronomy (IYA) 2009 is developing programs for all areas of Dark Skies Awareness. For many years the issue of light pollution focused on the impact to the astronomy industry. While this is an important area, research has shown that light pollution negatively impacts wildlife, their habitat, human health, and is a significant waste of energy. Since the message and impact of the effects of light pollution are much broader now, the message conveyed to the public must also be broader. Education programs directed at youth are a new frontier to reach out to a new audience about the adverse effects of too much artificial light at night. The International Dark-Sky Association (IDA) has developed educational presentations using the National Science Teachers Association Education Standards. These programs focus on youth between the ages of 5 to 17exploring new territory in the education of light pollution. The IDA education programs are broken down into three age groups; ages 5-9, 8-13, 12 and older. The presentations come complete with PowerPoint slides, discussion notes for each slide, and workbooks including age appropriate games to keep young audiences involved. A new presentation reflects the growing area of interest regarding the effects of too much artificial light at night on wildlife. This presentation outlines the known problems for ecosystems caused by artificial light at night. Insects are attracted to artificial lights and may stay near that light all night. This attraction interferes with their ability to migrate, mate, and look for food. Such behavior leads to smaller insect populations. Fewer insects in turn affect birds and bats, because they rely on insects as a food source. The IDA

  15. Patternless light outcoupling enhancement method for top-emission organic light-emitting diodes

    Science.gov (United States)

    Kim, Doo-Hoon; Lee, Ho-Nyeon

    2016-11-01

    An increase of 65% in the luminous flux of a top-emission organic light-emitting diode (TE-OLED) was obtained by fabricating a stacked N,N‧-bis(naphthalen-1-yl)-N,N‧-bis(phenyl)benzidine (NPB) (0.2 µm)/CaF2 (2.5 µm) light outcoupling layer on the TE-OLED. The high-refractive-index NPB layer extracted the trapped light energy in the TE-OLED for input into the light outcoupling layer and protected the top cathode of the TE-OLED from damage due to the CaF2 layer. The surface morphology of the CaF2 layer had an irregular shape consisting of randomly dispersed pyramids; the irregular structure scattered the waveguide mode energy into air. By combining the effects of the NPB and CaF2 layers, the external quantum efficiency of the TE-OLED was increased significantly. The light outcoupling layer can be fabricated using a thermal evaporation process without patterning and, hence, provides a practical solution for the enhancement of TE-OLED light outcoupling using a patternless fabrication process.

  16. ANALGESIC AND ANTIINFLAMMATORY EFFECTS OF TOTAL EXTRACT, FLAVONOID FRACTION AND VOLATILE OIL OF SALVIA HYDRANGEA

    National Research Council Canada - National Science Library

    V.A HAJ HASHEMI; A GHANADI; D MOSAVI

    2000-01-01

    .... At first, total extract, flavonoid fraction and volatile oil was prepared. Analgesic effect was assessed using light tail flick and acetic acid writhing test. Male wistar rats (180-220g) and mice (25±2g...

  17. Light Management in Optoelectronic Devices with Disordered and Chaotic Structures

    KAUST Repository

    Khan, Yasser

    2012-07-01

    With experimental realization, energy harvesting capabilities of chaotic microstructures were explored. Incident photons falling into chaotic trajectories resulted in energy buildup for certain frequencies. As a consequence, many fold enhancement in light trapping was observed. These ellipsoid like chaotic microstructures demonstrated 25% enhancement in light trapping at 450nm excitation and 15% enhancement at 550nm excitation. Optimization of these structures can drive novel chaos-assisted energy harvesting systems. In subsequent sections of the thesis, prospect of broadband light extraction from white light emitting diodes were investigated, which is an unchallenged but quintessential problem in solid-state lighting. Size dependent scattering allows microstructures to interact strongly with narrow-band light. If disorder is introduced in spread and sizes of microstructures, broadband light extraction is possible. A novel scheme with Voronoi tessellation to quantify disorder in physical systems was also introduced, and a link between voronoi disorder and state disorder of statistical mechanics was established. Overall, in this thesis some nascent concepts regarding disorder and chaos were investigated to efficiently manage electromagnetic waves in optoelectronic devices.

  18. Recent advances in light outcoupling from white organic light-emitting diodes

    Science.gov (United States)

    Gather, Malte C.; Reineke, Sebastian

    2015-01-01

    Organic light-emitting diodes (OLEDs) have been successfully introduced to the smartphone display market and have geared up to become contenders for applications in general illumination where they promise to combine efficient generation of white light with excellent color quality, glare-free illumination, and highly attractive designs. Device efficiency is the key requirement for such white OLEDs, not only from a sustainability perspective, but also because at the high brightness required for general illumination, losses lead to heating and may, thus, cause rapid device degradation. The efficiency of white OLEDs increased tremendously over the past two decades, and internal charge-to-photon conversion can now be achieved at ˜100% yield. However, the extraction of photons remains rather inefficient (typically <30%). Here, we provide an introduction to the underlying physics of outcoupling in white OLEDs and review recent progress toward making light extraction more efficient. We describe how structures that scatter, refract, or diffract light can be attached to the outside of white OLEDs (external outcoupling) or can be integrated close to the active layers of the device (internal outcoupling). Moreover, the prospects of using top-emitting metal-metal microcavity designs for white OLEDs and of tuning the average orientation of the emissive molecules within the OLED are discussed.

  19. Isoflavones hydrolisis and extraction

    Directory of Open Access Journals (Sweden)

    Jozilene Fernandes Farias dos Santos

    2012-12-01

    Full Text Available Isoflavones are found in leguminous species and are used as phytoestrogens widely used by industry for its beneficial effects as estrogens mimicked, antioxidant action and anti-cancer activity. The identification and quantification of isoflavones in plants is a need due to the high demand of industry. Several methods are used for its extraction, using organic solvents (methanol, ethanol and acetonitrile. Samples from five legumes species from Instituto de Zootecnia (IZ, Forage Gene Bank were tested. All seeds received a hydrothermic treatment immersed in pure water at 50°C for 12 hours. Seeds were then oven-dryed. In this work we tested the extraction using only the hydrothermic treatment and hyfrothermic treatment allied to methanol extaction protocol. Seeds were grinded and half of the samples were ressuspended in PBS (phosphate Buffer and the other half were submited to 4 mL of methanol and 1% of acetic acid, soaked for 5 hours, shaked every 15 minutes, at room temperature. The five legume species that we quantify isoflavones by enzyme immunoassay (EIA were: Calopogonium mucunoides, Bauhinia sp., Cajanus cajan, Galactia martii, Leucaena leucocephala. The extraction procedure is a recomendation of AOAC (Association of Official Analytical Chemists for isoflavone quantification. Ours results show an increase of extraction using methanol 80% plus acetic acid 1% and was obtained using solvent extraction in comparison to hydrothermic procedure alone (figure 1.

  20. Tevatron extraction microcomputer

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.

    1985-06-01

    Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper summarizes performance.

  1. Covariance of light-front models: pair current

    NARCIS (Netherlands)

    Melo, J.P.B.C. de; Frederico, T.; Naus, H.W.L.; Sauer, P.U.

    1999-01-01

    We compute the + component, i.e., j+ = j0 + j3, of the electromagnetic current of a composite spin-one two-fermion system for vanishing momentum transfer component q+ = q0 + q3. In particular, we extract the nonvanishing pair production amplitude on the light-front. It is a consequence of the longit

  2. Identification of Light-independent Inhibition of Human Immunodeficiency Virus-1 Infection through Bioguided Fractionation of Hypericum perforatum

    Science.gov (United States)

    Light-dependent activities against enveloped viruses in St. John's Wort (Hypericum perforatum) extracts have been extensively studied. In contrast, light-independent antiviral activity from this species has not. Here, we identify the light-independent inhibition of human immunodeficiency virus-1 (...

  3. Light Vector Mesons in the Nuclear Medium

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis; Djalali, Chaden; Tur, Clarisse; Mosel, Ulrich; Muehlich, Pascal; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, James; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gordon, Christopher; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Stepan; Stepanyan, Samuel; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Williams, Michael; Wolin, Elliott; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Bin; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen

    2008-07-01

    The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body eff

  4. Aircraft Lighting and Transparency Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Lighting and Transparencies with Night Combat Lab performs radiometric and photometric measurements of cockpit lighting and displays. Evaluates the day,...

  5. Biomaterials in light amplification

    Science.gov (United States)

    Mysliwiec, Jaroslaw; Cyprych, Konrad; Sznitko, Lech; Miniewicz, Andrzej

    2017-03-01

    Biologically produced or inspired materials can serve as optical gain media, i.e. they can exhibit the phenomenon of light amplification. Some of these materials, under suitable dye-doping and optical pumping conditions, show lasing phenomena. The emerging branch of research focused on obtaining lasing action in highly disordered and highly light scattering materials, i.e. research on random lasing, is perfectly suited for biological materials. The use of biomaterials in light amplification has been extensively reported in the literature. In this review we attempt to report on progress in the development of biologically derived systems able to show the phenomena of light amplification and random lasing together with the contribution of our group to this field. The rich world of biopolymers modified with molecular aggregates and nanocrystals, and self-organized at the nanoscale, offers a multitude of possibilities for tailoring luminescent and light scattering properties that are not easily replicated in conventional organic or inorganic materials. Of particular importance and interest are light amplification and lasing, or random lasing studies in biological cells and tissues. In this review we will describe nucleic acids and their complexes employed as gain media due to their favorable optical properties and ease of manipulation. We will report on research conducted on various biomaterials showing structural analogy to nucleic acids such as fluorescent proteins, gelatins in which the first distributed feedback laser was realized, and also amyloids or silks, which, due to their dye-doped fiber-like structure, allow for light amplification. Other materials that were investigated in that respect include polysaccharides, like starch exhibiting favorable photostability in comparison to other biomaterials, and chitosan, which forms photonic crystals or cellulose. Light amplification and random lasing was not only observed in processed biomaterials but also in living

  6. Indoor Lighting Facilities

    Science.gov (United States)

    Matsushima, Koji; Saito, Yoshinori; Ichikawa, Shigenori; Kawauchi, Takao; Tanaka, Tsuneo; Hirano, Rika; Tazuke, Fuyuki

    According to the statistics on building construction floor area from the Ministry of Land, Infrastructure, Transport and Tourism, the total floor area of building construction started in Japan in 2007 was 160,991 thousand square meters, or 14.8% less than the area of the previous year, and the reduction was the first reduction in the past five years. The office markets in Tokyo and Nagoya were active, as represented by the supplies of skyscrapers, and energy saving measures, such as the adoption of high efficiency lighting equipment, the control for initial stage illuminance, daylight harvesting, and the use of occupancy sensors, were well established. In the field of public construction, including museums, multi-purpose halls, and religious buildings, the total area of the new construction was 10.8% less than the total for the previous year, and this reduction was a continuation of an eleven-year trend. In spaces with high ceiling, the innovation for easy replacement of light sources used with reflection mirror systems and optical fibers was noted. Hospitals adapted to the expectation for improved services in their selection of lighting facilities to improve the residential environment for patients while taking into consideration the needs of the aging population, by their use of devices in corridors to help maintain a continuity of light. In libraries, a pendant system was developed to illuminate both ceilings and book shelves. In the field of theaters and halls, the time limit for repairing existing systems had come for the large facilities that were opened during the theater and hall construction boom of the 1960s through 1980s, and around 26 renovations were done. Almost all the renovations were conversions to intelligent dimming systems and lighting control desks. In the field of stores and commercial facilities, the atmosphere and glitter of the selling floor was produced by new light sources, such as ceramic metal halide lamps and LEDs, which have high

  7. Extracting oil from coffee

    Directory of Open Access Journals (Sweden)

    Elkin Mauricio López Fontal

    2010-04-01

    Full Text Available The present work describes oil being extracted from toasted coffee by the extrusion method; two products are obtained from this process: coffee oil and pulp. Toasted coffee was used which has a high amount of sensorial compounds. It should be noted that a significant criterion in evaluating the quality of coffee lies in its aroma. When extracting oil from coffee, a significant part of toasted coffee’s aromatic content leaves with it, varying according to the extraction method. A fixed oil having a high volatile load is thus obtained, presenting favourable sensory characteristics. The pulp was physically and chemically analysed to show its benefit and particular properties and, according to the results so obtained, it is a product having potential usefulness.

  8. A light knowledge model for linguistic applications.

    Science.gov (United States)

    Baud, R H; Lovis, C; Ruch, P; Rassinoux, A M

    2001-01-01

    Content extraction from medical texts is achievable today by linguistic applications, in so far as sufficient domain knowledge is available. Such knowledge represents a model of the domain and is hard to collect with sufficient depth and good coverage, despite numerous attempts. To leverage this task is a priority in order to benefit from the awaited linguistic tools. The light model is designed with this goal in mind. Syntactic and lexical information are generally available with large lexicons. A domain model should add the necessary semantic information. The authors have designed a light knowledge model for the collection of semantic information on the basis of the recognized syntactical and lexical attributes. It has been tailored for the acquisition of enough semantic information in order to retrieve terms of a controlled vocabulary from free texts, as for example, to retrieve Mesh terms from patient records.

  9. Discrete Line Congruences for Shading and Lighting

    KAUST Repository

    Wang, Jun

    2013-07-01

    Two-parameter families of straight lines (line congruences) are implicitly present in graphics and geometry processing in several important ways including lighting and shape analysis. In this paper we make them accessible to optimization and geometric computing, by introducing a general discrete version of congruences based on piecewise-linear correspondences between triangle meshes. Our applications of congruences are based on the extraction of a so-called torsion-free support structure, which is a procedure analogous to remeshing a surface along its principal curvature lines. A particular application of such structures are freeform shading and lighting systems for architecture. We combine interactive design of such systems with global optimization in order to satisfy geometric constraints. In this way we explore a new area where architecture can greatly benefit from graphics.

  10. Extraction Methods, Variability Encountered in

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition

  11. Extraction Methods, Variability Encountered in

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Bias in DNA extractions methods; Variation in DNA extraction methods Definition The variability in extraction methods is defined as differences in quality and quantity of DNA observed using various extraction protocols, leading to differences in outcome of microbial community composition as

  12. High-Efficiency Nitride-Base Photonic Crystal Light Sources

    Energy Technology Data Exchange (ETDEWEB)

    James Speck; Evelyn Hu; Claude Weisbuch; Yong-Seok Choi; Kelly McGroddy; Gregor Koblmuller; Elison Matioli; Elizabeth Rangel; Fabian Rol; Dobri Simeonov

    2010-01-31

    The research activities performed in the framework of this project represent a major breakthrough in the demonstration of Photonic Crystals (PhC) as a competitive technology for LEDs with high light extraction efficiency. The goals of the project were to explore the viable approaches to manufacturability of PhC LEDS through proven standard industrial processes, establish the limits of light extraction by various concepts of PhC LEDs, and determine the possible advantages of PhC LEDs over current and forthcoming LED extraction concepts. We have developed three very different geometries for PhC light extraction in LEDs. In addition, we have demonstrated reliable methods for their in-depth analysis allowing the extraction of important parameters such as light extraction efficiency, modal extraction length, directionality, internal and external quantum efficiency. The information gained allows better understanding of the physical processes and the effect of the design parameters on the light directionality and extraction efficiency. As a result, we produced LEDs with controllable emission directionality and a state of the art extraction efficiency that goes up to 94%. Those devices are based on embedded air-gap PhC - a novel technology concept developed in the framework of this project. They rely on a simple and planar fabrication process that is very interesting for industrial implementation due to its robustness and scalability. In fact, besides the additional patterning and regrowth steps, the process is identical as that for standard industrially used p-side-up LEDs. The final devices exhibit the same good electrical characteristics and high process yield as a series of test standard LEDs obtained in comparable conditions. Finally, the technology of embedded air-gap patterns (PhC) has significant potential in other related fields such as: increasing the optical mode interaction with the active region in semiconductor lasers; increasing the coupling of the incident

  13. Supercritical fluid extraction

    Science.gov (United States)

    Wai, Chien M.; Laintz, Kenneth

    1994-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  14. Genotoxicity of plant extracts

    Directory of Open Access Journals (Sweden)

    Vera M. F. Vargas

    1991-01-01

    Full Text Available Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome. Positive results were obtained for A. satureoides, B anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990 the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest.

  15. Lighting system with illuminance control

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an illumination control system comprising a plurality of outdoor luminaries and a motorized service vehicle. Each luminaire comprises a controllable light source producing a light illuminance. The motorized service vehicle comprises a light sensor configured...... to detect the light illuminance generated by the controllable light source at the motorized service vehicle. The motorized service vehicle computes light illuminance data based on the detected light illuminance and transmits these to the outdoor luminaire through a wireless communication link or stores...... the light illuminance data on a data recording device of the motorized service vehicle. The outdoor luminaire receives may use the light illuminance data to set or adjust a light illuminance of the controllable light source....

  16. Handbook of advanced lighting technology

    CERN Document Server

    Sun, Ching-Cherng; Zissis, Georges; Ma, Ruiqing

    2017-01-01

    The Handbook of Advanced Lighting Technology is a major reference work on the subject of light source science and technology, with particular focus on solid-state light sources – LEDs and OLEDs – and the development of 'smart' or 'intelligent' lighting systems; and the integration of advanced light sources, sensors, and adaptive control architectures to provide tailored illumination which is 'fit to purpose.' The concept of smart lighting goes hand-in-hand with the development of solid-state light sources, which offer levels of control not previously available with conventional lighting systems. This has impact not only at the scale of the individual user, but also at an environmental and wider economic level. These advances have enabled and motivated significant research activity on the human factors of lighting, particularly related to the impact of lighting on healthcare and education, and the Handbook provides detailed reviews of work in these areas. The potential applications for smart lighting span ...

  17. Enhancing the light-matter interaction using slow light: towards the concept of dense light

    OpenAIRE

    Thévenaz, Luc; Dicaire, Isabelle; Chin, Sang Hoon

    2012-01-01

    A couple of experiments are here presented to clarify the impact of slow light on light-matter interaction. The experiments are designed, so that the process generating slow light and the probed light-matter interaction only present a marginal cross-effect. The impact of slow light on simple molecular absorption could be separately evaluated under either material or structural slow light propagation in the same medium and led to an entirely different response.

  18. Sneaky light stop

    Directory of Open Access Journals (Sweden)

    Till Eifert

    2015-04-01

    Full Text Available A light supersymmetric top quark partner (stop with a mass nearly degenerate with that of the standard model (SM top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been suggested to give a handle for this ‘stealth stop’ scenario. We present an estimate of the potential impact a light stop may have on top quark mass measurements. The results indicate that certain light stop models may induce a bias of up to a few GeV, and that this effect can hide the shift in, and hence sensitivity from, cross-section measurements. Due to the different initial states, the size of the bias is slightly different between the LHC and the Tevatron. The studies make some simplifying assumptions for the top quark measurement technique, and are based on truth-level samples.

  19. Slow light beam splitter.

    Science.gov (United States)

    Xiao, Yanhong; Klein, Mason; Hohensee, Michael; Jiang, Liang; Phillips, David F; Lukin, Mikhail D; Walsworth, Ronald L

    2008-07-25

    We demonstrate a slow light beam splitter using rapid coherence transport in a wall-coated atomic vapor cell. We show that particles undergoing random and undirected classical motion can mediate coherent interactions between two or more optical modes. Coherence, written into atoms via electromagnetically induced transparency using an input optical signal at one transverse position, spreads out via ballistic atomic motion, is preserved by an antirelaxation wall coating, and is then retrieved in outgoing slow light signals in both the input channel and a spatially-separated second channel. The splitting ratio between the two output channels can be tuned by adjusting the laser power. The slow light beam splitter may improve quantum repeater performance and be useful as an all-optical dynamically reconfigurable router.

  20. Structured light scatteroscopy.

    Science.gov (United States)

    Krishnaswamy, Venkataramanan; Elliott, Jonathan T; McClatchy, David M; Barth, Richard J; Wells, Wendy A; Pogue, Brian W; Paulsen, Keith D

    2014-01-01

    A new imaging approach, structured light scatteroscopy (SLS), is demonstrated, which offers rapid wide-field imaging of microscopic morphological variations in bulk tissue surfaces. Elastic scattering of light offers exquisite sensitivity to ultrastructural changes at multiple size scales ranging from nanometers to millimeters, but in bulk tissues the confounding effects of molecular absorption and strong multiple scattering of light often lead to a dramatic reduction in scatter contrast and specificity. It is demonstrated that the SLS using structured high spatial frequency illumination and detection to probe the tissue achieves direct, absorption-independent, high-resolution maps of the scattering response. The scattering response is observed to be dependent on both the wavelength and spatial frequency of choice, indicating a potential for multiscale probing of ultrastructural changes in superficial tissue layers. This methodology can be easily applied in most wide-field imaging systems.

  1. Pupillary efficient lighting system

    Science.gov (United States)

    Berman, Samuel M.; Jewett, Don L.

    1991-01-01

    A lighting system having at least two independent lighting subsystems each with a different ratio of scotopic illumination to photopic illumination. The radiant energy in the visible region of the spectrum of the lighting subsystems can be adjusted relative to each other so that the total scotopic illumination of the combined system and the total photopic illumination of the combined system can be varied independently. The dilation or contraction of the pupil of an eye is controlled by the level of scotopic illumination and because the scotopic and photopic illumination can be separately controlled, the system allows the pupil size to be varied independently of the level of photopic illumination. Hence, the vision process can be improved for a given level of photopic illumination.

  2. Light sterile neutrinos

    Science.gov (United States)

    Gariazzo, S.; Giunti, C.; Laveder, M.; Li, Y. F.; Zavanin, E. M.

    2016-03-01

    The theory and phenomenology of light sterile neutrinos at the eV mass scale is reviewed. The reactor, gallium and Liquid Scintillator Neutrino Detector anomalies are briefly described and interpreted as indications of the existence of short-baseline oscillations which require the existence of light sterile neutrinos. The global fits of short-baseline oscillation data in 3 + 1 and 3 + 2 schemes are discussed, together with the implications for β-decay and neutrinoless double-β decay. The cosmological effects of light sterile neutrinos are briefly reviewed and the implications of existing cosmological data are discussed. The review concludes with a summary of future perspectives. This review is dedicated to the memory of Hai-Wei Long, our dear friend and collaborator, who passed away on 29 May 2015. He was an exceptionally kind person and an enthusiastic physicist. We deeply miss him.

  3. Advances in the extractive metallurgy of selected rare and precious metals

    Science.gov (United States)

    Hoffmann, James E.

    1991-04-01

    The broad field of extractive metallurgy, often perceived as an unimportant point of light in the universe of technology, has undergone significant, fundamental changes in the past 30 years. Improved extraction technologies now permit greater metal recovery, reduce the time that metal values are chemically locked up and diminish the economic impact of environmental regulations. Much of this accomplishment is due to the application of solvent extraction. As evidenced by improvements in the extraction of rare and precious metals, research in extractive metallurgy technology not only exists, but has achieved palpable results.

  4. Radioluminescent lighting technology

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The glow-in-the-dark stereotype that characterizes the popular image of nuclear materials is not accidental. When the French scientist, Henri Becquerel, first discovered radioactivity in 1896, he was interested in luminescence. Radioluminescence, the production of light from a mixture of energetic and passive materials, is probably the oldest practical application of the unstable nucleus. Tritium-based radioluminescent lighting, in spite of the biologically favorable character of the gaseous tritium isotope, was included in the general tightening of environmental and safety regulations. Tritium light manufacturers would have to meet two fundamental conditions: (1) The benefit clearly outweighed the risk, to the extent that even the perceived risk of a skeptical public would be overcome. (2) The need was significant enough that the customer/user would be willing and able to afford the cost of regulation that was imposed both in the manufacture, use and eventual disposal of nuclear materials. In 1981, researchers at Oak Ridge National Laboratory were investigating larger radioluminescent applications using byproduct nuclear material such as krypton-85, as well as tritium. By 1982, it appeared that large source, (100 Curies or more) tritium gas tube, lights might be useful for marking runways and drop zones for military operations and perhaps even special civilian aviation applications. The successful development of this idea depended on making the light bright enough and demonstrating that large gas tube sources could be used and maintained safely in the environment. This successful DOE program is now in the process of being completed and closed-out. Working closely with the tritium light industry, State governments and other Federal agencies, the basic program goals have been achieved. This is a detailed report of what they have learned, proven, and discovered. 91 refs., 29 figs., 5 tabs. (JF)

  5. [Light and Medicine].

    Science.gov (United States)

    Lemmer, Björn

    2016-12-01

    There would be no life without light. The rotation of the earth around its axis has introduced the development of biological clocks in all living subjects regulating all functions of the body. The rhythms best described are the 24-hour/circadian and the seasonal rhythms. The rhythmic composition around the body clock has great impact on health and disease, both in diagnostics and treatment. Nowadays, bright light, e.g. in seasonal affective disorder, can be regarded as a drug, being even more effective than selective serotonin reuptake inhibitors.

  6. Light is Heavy

    OpenAIRE

    Mark, M.B. van der; Hooft, G. W. 't

    2015-01-01

    Einstein's relativity theory appears to be very accurate, but at times equally puzzling. On the one hand, electromagnetic radiation must have zero rest mass in order to propagate at the speed of light, but on the other hand, since it definitely carries momentum and energy, it has non-zero inertial mass. Hence, by the principle of equivalence, it must have non-zero gravitational mass, and so, light must be heavy. In this paper, no new results will be derived, but a possibly surprising perspect...

  7. Optics, light and lasers

    CERN Document Server

    Meschede, Dieter

    2008-01-01

    Starting from the concepts of classical optics, Optics, Light and Lasers introduces in detail the phenomena of linear and nonlinear light matter interaction, the properties of modern laser sources, and the concepts of quantum optics. Several examples taken from the scope of modern research are provided to emphasize the relevance of optics in current developments within science and technology. The text has been written for newcomers to the topic and benefits from the author's ability to explain difficult sequences and effects in a straightforward and easily comprehensible way. To this second, c

  8. Ions and light

    CERN Document Server

    Bowers, Michael T

    2013-01-01

    Gas Phase Ion Chemistry, Volume 3: Ions and Light discusses how ions are formed by electron impact, ion-molecule reactions, or electrical discharge. This book discusses the use of light emitted by excited molecules to characterize either the chemistry that formed the excited ion, the structure of the excited ion, or both.Organized into 10 chapters, this volume begins with an overview of the extension of the classical flowing afterglow technique to include infrared and chemiluminescence and laser-induced fluorescence detection. This text then examines the experiments involving molecules that ar

  9. Kinematics grounded on light

    CERN Document Server

    Neda, Zoltan

    2015-01-01

    The space-time of modern physics is tailored on light. We rigorously construct the basic entities needed by kinematics: geometry of the physical space and time, using as tool electromagnetic waves, and particularly light-rays. After such a mathematically orthodox construction, the special theory of relativity will result naturally. One will clearly understand and easily accept all those puzzling consequences that makes presently the special theory of relativity hard to digest. Such an approach is extremely rewarding in teaching the main ideas of Einstein's relativity theory for high-school and/or university students. Interesting speculations regarding the fundaments and future of physics are made.

  10. Light is Heavy

    CERN Document Server

    van der Mark, M B

    2015-01-01

    Einstein's relativity theory appears to be very accurate, but at times equally puzzling. On the one hand, electromagnetic radiation must have zero rest mass in order to propagate at the speed of light, but on the other hand, since it definitely carries momentum and energy, it has non-zero inertial mass. Hence, by the principle of equivalence, it must have non-zero gravitational mass, and so, light must be heavy. In this paper, no new results will be derived, but a possibly surprising perspective on the above paradox is given.

  11. Light scattering reviews 8 radiative transfer and light scattering

    CERN Document Server

    Kokhanovsky, Alexander A

    2013-01-01

    Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.

  12. Second premolar serial extraction.

    Science.gov (United States)

    Joondeph, D R; Riedel, R A

    1976-02-01

    Serial extraction of mandibular second premolars should be considered if they are impacted or in cases with moderate arch length deficiency combined with an absence of dentofacial protrusion. The favorable dental changes associated with this approach greatly minimize future orthodontic treatment complexity and time.

  13. [Amebicidal plants extracts].

    Science.gov (United States)

    Derda, Monika; Hadaś, Edward; Thiem, Barbara; Sułek, Anna

    2004-01-01

    The free-living amoebae from genus Acanthamoeba are the causative agents of granulomatous amebic encephalitis (GAE), a chronic progressive disease of the central nervous system; amebic keratitis (AK), a chronic eye infection; amebic pneumitis (AP), a chronic lung infection, and skin infection. Chemotherapy of Acanthamoeba infection is problematic. The majority of infections have been fatal. Only a few cases are reported to have been treated successfully with very highly toxic drugs. The therapy might be succeed, if the diagnosis and therapy is made at very early stage of infection. In our experiments we used the following plant extracts: Solidago virgaurea, Solidago graminifolia, Rubus chamaemorus, Pueraria lobata, and natural plants products as ellagic acid and puerarin. Those therapeutic agents and plants extracts have been tested in vitro for amebicidal or amebostatic activity against pathogenic Acanthamoeba spp. Our results showed that methanol extracts obtained from plants are active against axenic pathogenic Acanthamoeba sp. trophozoites in vitro at concentration below 0.1 mg/ml. Further studies are needed to investigate whether these extracts are also effective in vivo in animal model of infection with Acanthamoeba sp.

  14. SPS extraction systems

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    One of the 3-m long electrostatics septa. The septum itself consists of 0.15 mm thick molybdenum wires with a 1.5 mm pitch. Each of the two SPS extraction systems will contain four of these electrostatic septa.

  15. Pneumomediastinum after Tooth Extraction

    OpenAIRE

    Ilhan Ocakcioglu; Serhat Koyuncu; Mustafa Kupeli; Oguzhan Bol

    2016-01-01

    Pneumomediastinum is defined as the presence of air in mediastinum. Pneumomediastinum can sometimes occur after surgery. Pneumomediastinum seen after dental procedures is rare. We presented the case of subcutaneous emphysema developed in the neck and upper chest after tooth extraction and discussed the possible mechanisms of pneumomediastinum.

  16. Endophthalmitis following cataract extraction.

    Science.gov (United States)

    McClellan, K; Coster, D J; Badenoch, P R; Sanders, R; Chandraratnam, E; Kupa, A

    1987-02-01

    We describe a case of bacterial endophthalmitis complicating routine cataract extraction and intraocular lens implantation in a 91-year-old woman. The ocular and systemic factors that may have predisposed to intraocular infection in this case, and the possibility of predicting these pre-operatively, are discussed.

  17. LEAR: antiproton extraction lines

    CERN Multimedia

    Photographic Service

    1992-01-01

    Antiprotons, decelerated in LEAR to a momentum of 100 MeV/c (kinetic energy of 5.3 MeV), were delivered to the experiments in an "Ultra-Slow Extraction", dispensing some 1E9 antiprotons over times counted in hours. Beam-splitters and a multitude of beam-lines allowed several users to be supplied simultaneously.

  18. Synthesis and antimicrobial activity of palladium nanoparticles from Prunus × yedoensis leaf extract

    Science.gov (United States)

    The eco-friendly production of palladium nanoparticles (PdNPs) by Prunus × yedoensis tree leaf extract was studied for the first time. Initial confirmation of PdNP production was confirmed by a color change from light yellow to dark brown. The optimization parameters show that pH 7, 8% leaf extract,...

  19. Light therapies for acne.

    Science.gov (United States)

    Barbaric, Jelena; Abbott, Rachel; Posadzki, Pawel; Car, Mate; Gunn, Laura H; Layton, Alison M; Majeed, Azeem; Car, Josip

    2016-09-27

    Acne vulgaris is a very common skin problem that presents with blackheads, whiteheads, and inflamed spots. It frequently results in physical scarring and may cause psychological distress. The use of oral and topical treatments can be limited in some people due to ineffectiveness, inconvenience, poor tolerability or side-effects. Some studies have suggested promising results for light therapies. To explore the effects of light treatment of different wavelengths for acne. We searched the following databases up to September 2015: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, Embase and LILACS. We searched ISI Web of Science and Dissertation Abstracts International (from inception). We also searched five trials registers, and grey literature sources. We checked the reference lists of studies and reviews and consulted study authors and other experts in the field to identify further references to relevant randomised controlled trials (RCTs). We updated these searches in July 2016 but these results have not yet been incorporated into the review. We included RCTs of light for treatment of acne vulgaris, regardless of language or publication status. We used standard methodological procedures expected by Cochrane. We included 71 studies, randomising a total of 4211 participants.Most studies were small (median 31 participants) and included participants with mild to moderate acne of both sexes and with a mean age of 20 to 30 years. Light interventions differed greatly in wavelength, dose, active substances used in photodynamic therapy (PDT), and comparator interventions (most commonly no treatment, placebo, another light intervention, or various topical treatments). Numbers of light sessions varied from one to 112 (most commonly two to four). Frequency of application varied from twice daily to once monthly.Selection and performance bias were unclear in the majority of studies. Detection bias was unclear for participant-assessed outcomes and low for investigator

  20. Light, colour and the eye

    CERN Document Server

    Sylvester, Doug

    1995-01-01

    These illuminating topics include ""Light and Color"", where students are introduced to luminous and illuminated objects, transparent, translucent and opaque objects, and investigate light's property of travelling in straight lines. Refraction, bending light and the use of prisms to ""break"" white light into the colors of the rainbow are also explored.

  1. Coupling light to periodic nanostructures

    NARCIS (Netherlands)

    Driessen, Eduard Frans Clemens

    2009-01-01

    This thesis describes coupling of light to periodic structures. A material is patterned with a regular pattern on a length scale comparable to the wavelength of light. With these structures, light can be manipulated very precisely. The structures find applications in semiconductor lasers, light emit

  2. Freeform reflectors for architectural lighting.

    Science.gov (United States)

    Zhu, Ruidong; Hong, Qi; Zhang, Hongxia; Wu, Shin-Tson

    2015-12-14

    We propose an improved method to design freeform reflectors for architectural lighting: one for accent lighting and another for large area wall washing. The designed freeform reflectors effectively distribute light fluxes over the target surfaces, and generate appropriate illumination patterns for comfortable visual environments, which provides greater flexibility for lighting designs, allows many challenging designs, and improves energy-efficiency simultaneously.

  3. Green light to slaughter

    NARCIS (Netherlands)

    Reinhart, T.

    2000-01-01

    In the Sharm-al-Sheikh summit last week, Barak got from the US his green light to slaughter. To judge by the Israeli media, what we have seen so far is just the prelude. "The most important time will come in the middle of next week, when...Israel will have to consider taking the initiative, rather t

  4. Conceptualization of Light Refraction

    Science.gov (United States)

    Sokolowski, Andrzej

    2013-01-01

    There have been a number of papers dealing quantitatively with light refraction. Yet the conceptualization of the phenomenon that sets the foundation for a more rigorous math analysis is minimized. The purpose of this paper is to fill that gap. (Contains 3 figures.)

  5. Lights and Larvae

    Science.gov (United States)

    TItlow, Josh; Anderson, Heidi; Cooper, Robin

    2014-01-01

    Switching genes between organisms and controlling an animal's brain using lasers may seem like science fiction, but with advancements in a technique called optogenetics, such experiments are now common in neuroscience research. Optogenetics combines recombinant DNA technology with a controlled light source to help researchers address…

  6. Space Made Light

    DEFF Research Database (Denmark)

    Gigone, Fabio

    2009-01-01

    These drawings, published in their first book "Space Made Light", reveal concepts and layouts, physical qualities and technological details, research procedures and origin of the materials, logistics and timetables of planning and realization. The diagrams have been conceived also for several...

  7. Plasmonics light modulators

    DEFF Research Database (Denmark)

    Babicheva, Viktoriia; Malureanu, Radu; Lavrinenko, Andrei

    Surface plasmon polaritons (SPPs) are waves propagating at the interface between a metal and a dielectric and, due to their tight confinement, may be used for nanoscale control of the light propagation. Thus, photonic integrated circuits can benefit from devices using SPPs because of their highly...

  8. Burnout and Light Treatment

    NARCIS (Netherlands)

    Meesters, Y.; Waslander, M.

    The core symptom of the burnout syndrome is emotional exhaustion, which leads to impaired functioning on the job. Studies of sufferers of seasonal affective disorders and of healthy people show that energy levels can be improved by exposing them to bright light. It is hypothesized that energy levels

  9. Faster Than Light Communication

    CERN Document Server

    Michalski, M

    1999-01-01

    If it is possible to measure any photon at arbitrary polarization state with the probability arbitrary close to 1, we can force photon from entangled photon pair to be measured in desired state and project the second photon to the parallel state. Measurement performed on the second photon (which is arbitrary far away from the first) makes possible faster than light communication.

  10. Light element ceramics

    OpenAIRE

    Rao, KJ; Varma, KBR; Raju, AR

    1988-01-01

    An overview of a few structually important light element ceramics is presented. Included in the overview are silicon nitide, sialon, aluminium nitride, boron carbide and silicon carbide. Methods of preparation, characterization and industrial applications of these ceramics are summarized. Mechanical properties, industrial production techniques and principal uses of these ceramics are emphasized.

  11. Light activated bionanodevices

    CSIR Research Space (South Africa)

    Sparrow, RW

    2006-02-27

    Full Text Available The aim of this research is to develop a device that will move a rod in 8 nm controllable steps. The researchers are utilising the biological principles and materials of photosynthetic light (energy) harvesting and transfer, ATPsynthase, ATP...

  12. Burnout and Light Treatment

    NARCIS (Netherlands)

    Meesters, Y.; Waslander, M.

    2010-01-01

    The core symptom of the burnout syndrome is emotional exhaustion, which leads to impaired functioning on the job. Studies of sufferers of seasonal affective disorders and of healthy people show that energy levels can be improved by exposing them to bright light. It is hypothesized that energy levels

  13. Light-Front QCD

    CERN Document Server

    Brodsky, S J

    2004-01-01

    In these lectures, I survey a number of applications of light-front methods to hadron and nuclear physics phenomenology and dynamics, Light-front Fock-state wavefunctions provide a frame-independent representation of hadrons in terms of their fundamental quark and gluon degrees of freedom. Nonperturbative methods for computing LFWFs in QCD are discussed, including string/gauge duality which predicts the power-law fall-off at high momentum transfer of light-front Fock-state hadronic wavefunctions with an arbitrary number of constituents and orbital angular momentum. The AdS/CFT correspondence has important implications for hadron phenomenology in the conformal limit, including an all-orders derivation of counting rules for exclusive processes. One can also compute the hadronic spectrum of near-conformal QCD assuming a truncated AdS/CFT space. The quantum fluctuations represented by the light-front Fock expansion leads to novel QCD phenomena such as color transparency, intrinsic heavy quark distributions, diffr...

  14. Radioluminescent polymer lights

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, G.A.; Nelson, D.A.; Molton, P.M.

    1990-09-01

    The preparation of radioluminescent light sources where the tritium is located on the aryl-ring in a polymer has been demonstrated with deuterium/tritium substitution. This report discusses tests, results, and future applications of radioluminescent polymers. 10 refs. (FI)

  15. Light water reactor program

    Energy Technology Data Exchange (ETDEWEB)

    Franks, S.M.

    1994-12-31

    The US Department of Energy`s Light Water Reactor Program is outlined. The scope of the program consists of: design certification of evolutionary plants; design, development, and design certification of simplified passive plants; first-of-a-kind engineering to achieve commercial standardization; plant lifetime improvement; and advanced reactor severe accident program. These program activities of the Office of Nuclear Energy are discussed.

  16. Polarized Light: Three Demonstrations.

    Science.gov (United States)

    Goehmann, Ruth; Welty, Scott

    1984-01-01

    Describes three demonstrations used in the Chicago Museum of Science and Industry polarized light show. The procedures employed are suitable for the classroom by using smaller polarizers and an overhead projector. Topic areas include properties of cellophane tape, nondisappearing arrows, and rope through a picket fence. (JN)

  17. Green light to slaughter

    NARCIS (Netherlands)

    Reinhart, T.

    2006-01-01

    In the Sharm-al-Sheikh summit last week, Barak got from the US his green light to slaughter. To judge by the Israeli media, what we have seen so far is just the prelude. "The most important time will come in the middle of next week, when...Israel will have to consider taking the initiative, rather t

  18. Photoacoustics with coherent light

    Directory of Open Access Journals (Sweden)

    Emmanuel Bossy

    2016-03-01

    Full Text Available Since its introduction in the mid-nineties, photoacoustic imaging of biological tissue has been one of the fastest growing biomedical imaging modality, and its basic principles are now considered as well established. In particular, light propagation in photoacoustic imaging is generally considered from the perspective of transport theory. However, recent breakthroughs in optics have shown that coherent light propagating through optically scattering medium could be manipulated towards novel imaging approaches. In this article, we first provide an introduction to the relevant concepts in the field, and then review the recent works showing that it is possible to exploit the coherence of light in conjunction with photoacoustics. We illustrate how the photoacoustic effect can be used as a powerful feedback mechanism for optical wavefront shaping in complex media, and conversely show how the coherence of light can be exploited to enhance photoacoustic imaging, for instance in terms of spatial resolution or for designing minimally invasive endoscopic devices. Finally, we discuss the current challenges and perspectives down the road towards practical applications in the field of photoacoustic imaging.

  19. Light in the temples.

    Science.gov (United States)

    Krupp, E. C.

    Contents: 1. The dawn of archaeoastronomy. 2. Stalking Lockyer. 3. Solar connotations at Karnak. 4. Solar sanctuaries at Abu Simbel. 5. Another look at the Sun. 6. The great temple of Amun-Re at Karnak. 7. The solar sanctuary of Hatshepsut's mortuary temple at Deir el-Bahri. 8. The Sun temple of Neuserre' at Abu Ghurab. 9. Shedding light on the temples.

  20. The yellow Light Offensive

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Arevised traffic regulation, seen as the harshest ever by many, took effect on January 1. Accordingly, drivers who run yellow lights will have six points deducted from the 12 allocated on their licenses. Those who have any part of their vehicles crossing the line at the time of change will not be punished.