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Sample records for alternative ambient illumination

  1. Light emitting diodes as an alternative ambient illumination source in photolithography environment

    DEFF Research Database (Denmark)

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

    2009-01-01

    We explored an alternative light emitting diode (LED) - based solution to replace the existing yellow fluorescent light tubes (YFT) used in photolithography rooms. A no-blue LED lamp was designed and a prototype was fabricated. For both solutions, the spectral power distribution (SPD) was measured......, the colorimetric values were calculated, and a visual comparison using Gretagmacbeth colorcharts was performed. The visual comparison showed that the LED bulb was better to render colors despite a low color rendering index (CRI). Furthermore, the LED bulb was tested in a photolithography room...... and there was no exposure to the photoresist even after 168 hours illumination....

  2. Adaptive Ambient Illumination Based on Color Harmony Model

    Science.gov (United States)

    Kikuchi, Ayano; Hirai, Keita; Nakaguchi, Toshiya; Tsumura, Norimichi; Miyake, Yoichi

    We investigated the relationship between ambient illumination and psychological effect by applying a modified color harmony model. We verified the proposed model by analyzing correlation between psychological value and modified color harmony score. Experimental results showed the possibility to obtain the best color for illumination using this model.

  3. Alternative Packaging for Back-Illuminated Imagers

    Science.gov (United States)

    Pain, Bedabrata

    2009-01-01

    An alternative scheme has been conceived for packaging of silicon-based back-illuminated, back-side-thinned complementary metal oxide/semiconductor (CMOS) and charge-coupled-device image-detector integrated circuits, including an associated fabrication process. This scheme and process are complementary to those described in "Making a Back-Illuminated Imager With Back-Side Connections" (NPO-42839), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 38. To avoid misunderstanding, it should be noted that in the terminology of imaging integrated circuits, "front side" or "back side" does not necessarily refer to the side that, during operation, faces toward or away from a source of light or other object to be imaged. Instead, "front side" signifies that side of a semiconductor substrate upon which the pixel pattern and the associated semiconductor devices and metal conductor lines are initially formed during fabrication, and "back side" signifies the opposite side. If the imager is of the type called "back-illuminated," then the back side is the one that faces an object to be imaged. Initially, a back-illuminated, back-side-thinned image-detector is fabricated with its back side bonded to a silicon handle wafer. At a subsequent stage of fabrication, the front side is bonded to a glass wafer (for mechanical support) and the silicon handle wafer is etched away to expose the back side. The frontside integrated circuitry includes metal input/output contact pads, which are rendered inaccessible by the bonding of the front side to the glass wafer. Hence, one of the main problems is to make the input/output contact pads accessible from the back side, which is ultimately to be the side accessible to the external world. The present combination of an alternative packaging scheme and associated fabrication process constitute a solution of the problem.

  4. Ambient light-based optical biosensing platform with smartphone-embedded illumination sensor.

    Science.gov (United States)

    Park, Yoo Min; Han, Yong Duk; Chun, Hyeong Jin; Yoon, Hyun C

    2017-07-15

    We present a hand-held optical biosensing system utilizing a smartphone-embedded illumination sensor that is integrated with immunoblotting assay method. The smartphone-embedded illumination sensor is regarded as an alternative optical receiver that can replaces the conventional optical analysis apparatus because the illumination sensor can respond to the ambient light in a wide range of wavelengths, including visible and infrared. To demonstrate the biosensing applicability of our system employing the enzyme-mediated immunoblotting and accompanying light interference, various types of ambient light conditions including outdoor sunlight and indoor fluorescent were tested. For the immunoblotting assay, the biosensing channel generating insoluble precipitates as an end product of the enzymatic reaction is fabricated and mounted on the illumination sensor of the smartphone. The intensity of penetrating light arrives on the illumination sensor is inversely proportional to the amount of precipitates produced in the channel, and these changes are immediately analyzed and quantified via smartphone software. In this study, urinary C-terminal telopeptide fragment of type II collagen (uCTX-II), a biomarker of osteoarthritis diagnosis, was tested as a model analyte. The developed smartphone-based sensing system efficiently measured uCTX-II in the 0-5ng/mL concentration range with a high sensitivity and accuracy under various light conditions. These assay results show that the illumination sensor-based optical biosensor is suitable for point-of-care testing (POCT). Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Retrieval of reflections from ambient noise using illumination diagnosis

    Science.gov (United States)

    Vidal, C. Almagro; Draganov, D.; van der Neut, J.; Drijkoningen, G.; Wapenaar, K.

    2014-09-01

    Seismic interferometry (SI) enables the retrieval of virtual sources at the location of receivers. In the case of passive SI, no active sources are used for the retrieval of the reflection response of the subsurface, but ambient-noise recordings only. The resulting retrieved response is determined by the illumination characteristics of the recorded ambient noise. Characteristics like geometrical distribution and signature of the noise sources, together with the complexity of the medium and the length of the noise records, determine the quality of the retrieved virtual-shot events. To retrieve body wave reflections, one needs to correlate body-wave noise. A source of such noise might be regional seismicity. In regions with notable human presence, the dominant noise sources are generally located at or close to the surface. In the latter case, the noise will be dominated by surface waves and consequently also the retrieved virtual common-source panels will contain dominant retrieved surface waves, drowning out possible retrieved reflections. In order to retrieve reflection events, suppression of the surface waves becomes the most important pre-processing goal. Because of the reasons mentioned above, we propose a fast method to evaluate the illumination characteristics of ambient noise using the correlation results from ambient-noise records. The method is based on the analysis of the so-called source function of the retrieved virtual-shot panel, and evaluates the apparent slowness of arrivals in the correlation results that pass through the position of the virtual source and at zero time. The results of the diagnosis are used to suppress the retrieval of surface waves and therefore to improve the quality of the retrieved reflection response. We explain the approach using modelled data from transient and continuous noise sources and an example from a passive field data set recorded at Annerveen, Northern Netherlands.

  6. Reducing flicker due to ambient illumination in camera captured images

    Science.gov (United States)

    Kim, Minwoong; Bengtson, Kurt; Li, Lisa; Allebach, Jan P.

    2013-02-01

    The flicker artifact dealt with in this paper is the scanning distortion arising when an image is captured by a digital camera using a CMOS imaging sensor with an electronic rolling shutter under strong ambient light sources powered by AC. This type of camera scans a target line-by-line in a frame. Therefore, time differences exist between the lines. This mechanism causes a captured image to be corrupted by the change of illumination. This phenomenon is called the flicker artifact. The non-content area of the captured image is used to estimate a flicker signal that is a key to being able to compensate the flicker artifact. The average signal of the non-content area taken along the scan direction has local extrema where the peaks of flicker exist. The locations of the extrema are very useful information to estimate the desired distribution of pixel intensities assuming that the flicker artifact does not exist. The flicker-reduced images compensated by our approach clearly demonstrate the reduced flicker artifact, based on visual observation.

  7. Ten Minutes of α-tACS and Ambient Illumination Independently Modulate EEG α-Power

    Directory of Open Access Journals (Sweden)

    Heiko I. Stecher

    2017-05-01

    Full Text Available Transcranial alternating current stimulation (tACS sees increased use in neurosciences as a tool for the exploration of brain oscillations. It has been shown that tACS stimulation in specific frequency bands can result in aftereffects of modulated oscillatory brain activity that persist after the stimulation has ended. The general relationship between persistency of the effect and duration of stimulation is sparsely investigated but previous research has shown that the occurrence of tACS aftereffects depends on the brain state before and during stimulation. Early alpha neurofeedback research suggests that particularly in the alpha band the responsiveness to a manipulation depends on the ambient illumination during measurement. Therefore, in the present study we assessed the brain’s susceptibility to tACS at the individual alpha frequency during darkness compared to ambient illumination. We measured alpha power after 10 min of stimulation in 30 participants while they continuously performed a visual vigilance task. Our results show that immediately after stimulation, the alpha power in the illumination condition for both the stimulated and sham group has increased by only about 7%, compared to about 20% in both groups in the ‘dark’ condition. For the group that did not receive stimulation, the power in darkness remained stable after stimulation, whereas the power in light increased by an additional 10% during the next 30 min. For the group that did receive stimulation, alpha power during these 30 min increased by another 11% in light and 22% in darkness. Since alpha power already increased by about 10% without stimulation, the effect of illumination does not seem to have interacted with the effect of stimulation. Instead, both effects seem to have added up linearly. Although our findings do not show that illumination-induced differences in oscillatory activity influence the susceptibility toward tACS, they stress the importance of

  8. The relationship between ambient illumination and psychological factors in viewing of display Images

    Science.gov (United States)

    Iwanami, Takuya; Kikuchi, Ayano; Kaneko, Takashi; Hirai, Keita; Yano, Natsumi; Nakaguchi, Toshiya; Tsumura, Norimichi; Yoshida, Yasuhiro; Miyake, Yoichi

    2009-01-01

    In this paper, we have clarified the relationship between ambient illumination and psychological factors in viewing of display images. Psychological factors were obtained by the factor analysis with the results of the semantic differential (SD) method. In the psychological experiments, subjects evaluated the impressions of displayed images with changing ambient illuminating conditions. The illumination conditions were controlled by a fluorescent ceiling light and a color LED illumination which was located behind the display. We experimented under two kinds of conditions. One was the experiment with changing brightness of the ambient illumination. The other was the experiment with changing the colors of the background illumination. In the results of the experiment, two factors "realistic sensation, dynamism" and "comfortable," were extracted under different brightness of the ambient illumination of the display surroundings. It was shown that the "comfortable" was improved by the brightness of display surroundings. On the other hand, when the illumination color of surroundings was changed, three factors "comfortable," "realistic sensation, dynamism" and "activity" were extracted. It was also shown that the value of "comfortable" and "realistic sensation, dynamism" increased when the display surroundings were illuminated by the average color of the image contents.

  9. Ambient illumination revisited: A new adaptation-based approach for optimizing medical imaging reading environments

    International Nuclear Information System (INIS)

    Chawla, Amarpreet S.; Samei, Ehsan

    2007-01-01

    Ambient lighting in soft-copy reading rooms is currently kept at low values to preserve contrast rendition in the dark regions of a medical image. Low illuminance levels, however, create inadequate viewing conditions and may also cause eye strain. This eye strain may be potentially attributed to notable variations in the luminance adaptation state of the reader's eyes when moving the gaze intermittently between the brighter display and darker surrounding surfaces. This paper presents a methodology to minimize this variation and optimize the lighting conditions of reading rooms by exploiting the properties of liquid crystal displays (LCDs) with low diffuse reflection coefficients and high luminance ratio. First, a computational model was developed to determine a global luminance adaptation value, L adp , when viewing a medical image on display. The model is based on the diameter of the pupil size, which depends on the luminance of the observed object. Second, this value was compared with the luminance reflected off surrounding surfaces, L s , under various conditions of room illuminance, E, different values of diffuse reflection coefficients of surrounding surfaces, R s , and calibration settings of a typical LCD. The results suggest that for typical luminance settings of current LCDs, it is possible to raise ambient illumination to minimize differences in eye adaptation, potentially reducing visual fatigue while also complying with the TG18 specifications for controlled contrast rendition. Specifically, room illumination in the 75-150 lux range and surface diffuse reflection coefficients in the practical range of 0.13-0.22 sr -1 provide an ideal setup for typical LCDs. Future LCDs with lower diffuse reflectivity and with higher inherent luminance ratios can provide further improvement of ergonomic viewing conditions in reading rooms

  10. Investigating the Use of an Adjustment Task to Set Preferred Colour of Ambient Illumination

    DEFF Research Database (Denmark)

    Logadóttir, Ásta; Fotios, Steve A.; Christoffersen, Jens

    2013-01-01

    An experiment was carried out to examine the method of adjustment when determining user preferences for the colour appearance of ambient lighting. A booth was lit using luminaires containing an array of white and coloured light emitting diodes (LEDs), allowing continuous variation of correlated...... different CCT stimulus ranges within the available range. All three ranges led to significantly different results for preferred CCT: 3288, 3490 and 3671 K. The experimental results confirmed that stimulus range, anchor and adaptation time have significant effect on the preferred CCT determined using...

  11. Etanercept (Enbrel® alternative storage at ambient temperature

    Directory of Open Access Journals (Sweden)

    Shannon E

    2017-07-01

    Full Text Available Edel Shannon,1 Joanne Daffy,2 Heather Jones,3 Andrea Paulson,4 Steven M Vicik5 1Global Chemistry, Manufacturing, and Controls Regulatory, 2Contract Operations Quality Assurance, Pfizer Ireland Pharmaceuticals, Clondalkin, Dublin, Ireland; 3Medical Affairs, Pfizer, Collegeville, PA, USA; 4Pharmaceutical Research and Development, 5Global Supply Product Portfolio Management, Pfizer Biotech, Andover, MA, USA Background: Biologic disease-modifying antirheumatic drugs, including tumor necrosis factor inhibitors such as etanercept (Enbrel®, have improved outcomes for patients with rheumatic and other inflammatory diseases, with sustained remission being the optimal goal for patients with rheumatoid arthritis. Flexible and convenient treatment options, compatible with modern lifestyle, are important in helping patients maintain treatment and manage their disease. Etanercept drug product (DP is available in lyophilized powder (Lyo for solution injection, prefilled syringe, and prefilled pen presentations and is typically stored under refrigerated conditions. We aimed to generate a comprehensive analytical data package from stability testing of key quality attributes, consistent with regulatory requirements, to determine whether the product profile of etanercept is maintained at ambient temperature. Methods: Test methods assessing key attributes of purity, quality, potency, and safety were performed over time, following storage of etanercept DP presentations under a range of conditions. Results: Results and statistical analysis from stability testing (based on size exclusion high-performance liquid chromatography, hydrophobic interaction chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis Coomassie across all etanercept presentations (10 and 25 mg/vial Lyo DP; 25 and 50 mg prefilled syringe DP; 50 mg prefilled pen DP showed key stability-indicating parameters were within acceptable limits through the alternative storage

  12. Solid-state semiconductors are better alternatives to arc-lamps for efficient and uniform illumination in minimal access surgery.

    Science.gov (United States)

    Lee, Alex C H; Elson, Daniel S; Neil, Mark A; Kumar, Sunil; Ling, Bingo W; Bello, Fernando; Hanna, George B

    2009-03-01

    Current arc-lamp illumination systems have a number of technical and ergonomic limitations. White light-emitting diodes (LEDs) are energy-efficient solid-state lighting devices which are small, durable and inexpensive. Their use as an alternative to arc-lamp light sources in minimal access surgery has not been explored. This study aims to develop an LED-based endo-illuminator and to determine its lighting characteristics for use in minimal access surgery. We developed an LED endo-illuminator using a white LED mounted at the tip of a steel rod. Offline image analysis was carried out to compare the illuminated field using the LED endo-illuminator or an arc-lamp based endoscope in terms of uniformity, shadow sharpness and overall image intensity. Direct radiometric power measurements in light intensity and stability were obtained. Visual perception of fine details at the peripheral endoscopic field was assessed by 13 subjects using the different illumination systems. Illumination from the LED endo-illuminator was more uniform compared to illumination from an arc-lamp source, especially at the closer distance of 4 cm (0.0006 versus 0.0028 arbitrary units--lower value indicates more uniform illumination). The shadows were also sharper (edge widths of 16 versus 44 pixels for the first edge and 15 versus 61 pixels for the second edge). The overall mean image intensity was higher (127 versus 100 arbitrary units) when using the autoshutter mode despite the lower direct radiometric power, about one tenth of the arc-lamp endoscopic system. The illumination was also more stable with less flickering (0.02% versus 5% of total power in non-DC components). Higher median scores on visual perception was also obtained (237 versus 157, p arc-lamp-based system currently used.

  13. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Rooftop Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Bargach, Youssef [Navigant Consulting Inc., Burlington, MA (United States)

    2016-09-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-Global Warming Potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants relative to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in packaged or Rooftop Unit (RTU) air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerants selection process, the test procedures, and the final results.

  14. Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy—Use of Greenhouses and Artificial Light Sources

    DEFF Research Database (Denmark)

    Lerche, Catharina; Heerfordt, Ida M; Heydenreich, Jakob

    2016-01-01

    to photobleach protoporphyrin IX (PpIX). Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector), white light...... was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation...

  15. Alternatives to Outdoor Daylight Illumination for Photodynamic Therapy—Use of Greenhouses and Artificial Light Sources

    Directory of Open Access Journals (Sweden)

    Catharina M. Lerche

    2016-02-01

    Full Text Available Daylight-mediated photodynamic therapy (daylight PDT is a simple and pain free treatment of actinic keratoses. Weather conditions may not always allow daylight PDT outdoors. We compared the spectrum of five different lamp candidates for indoor “daylight PDT” and investigated their ability to photobleach protoporphyrin IX (PpIX. Furthermore, we measured the amount of PpIX activating daylight available in a glass greenhouse, which can be an alternative when it is uncomfortable for patients to be outdoors. The lamps investigated were: halogen lamps (overhead and slide projector, white light-emitting diode (LED lamp, red LED panel and lamps used for conventional PDT. Four of the five light sources were able to photobleach PpIX completely. For halogen light and the red LED lamp, 5000 lux could photobleach PpIX whereas 12,000 lux were needed for the white LED lamp. Furthermore, the greenhouse was suitable for daylight PDT since the effect of solar light is lowered only by 25%. In conclusion, we found four of the five light sources and the greenhouse usable for indoor daylight PDT. The greenhouse is beneficial when the weather outside is rainy or windy. Only insignificant ultraviolet B radiation (UVB radiation passes through the greenhouse glass, so sun protection is not needed.

  16. Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Munk, Jeffrey D [ORNL; Shrestha, Som S [ORNL; Linkous, Randall Lee [ORNL; Goetzler, William [Navigant Consulting Inc.; Guernsey, Matt [Navigant Consulting Inc.; Kassuga, Theo [Navigant Consulting Inc.

    2015-08-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

  17. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Kassuga, Theo [Navigant Consulting Inc., Burlington, MA (United States)

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  18. Effect of ultraviolet illumination and ambient gases on the photoluminescence and electrical properties of nanoporous silicon layer for organic vapor sensor.

    Science.gov (United States)

    Atiwongsangthong, Narin

    2012-08-01

    The purpose of this research, the nanoporous silicon layer were fabricated and investigated the physical properties such as photoluminescence and the electrical properties in order to develop organic vapor sensor by using nanoporous silicon. The Changes in the photoluminescence intensity of nanoporous silicon samples are studied during ultraviolet illumination in various ambient gases such as nitrogen, oxigen and vacuum. In this paper, the nanoporous silicon layer was used as organic vapor adsorption and sensing element. The advantage of this device are simple process compatible in silicon technology and usable in room temperature. The structure of this device consists of nanoporous silicon layer which is formed by anodization of silicon wafer in hydrofluoric acid solution and aluminum electrode which deposited on the top of nanoporous silicon layer by evaporator. The nanoporous silicon sensors were placed in a gas chamber with various organic vapor such as ethanol, methanol and isopropyl alcohol. From studying on electrical characteristics of this device, it is found that the nanoporous silicon layer can detect the different organic vapor. Therefore, the nanoporous silicon is important material for organic vapor sensor and it can develop to other applications about gas sensors in the future.

  19. Evaluation of Alternative Methods for Testing the Bioefficacy of Household Ambient Insecticide Products Against Aedes albopictus.

    Science.gov (United States)

    Cassini, Rudi; Scremin, Mara; Contiero, Barbara; Drago, Andrea; Vettorato, Christian; Marcer, Federica; di Regalbono, Antonio Frangipane

    2016-06-01

    Ambient insecticides are receiving increasing attention in many developed countries because of their value in reducing mosquito nuisance. As required by the European Union Biocidal Products Regulation 528/2012, these devices require appropriate testing of their efficacy, which is based on estimating the knockdown and mortality rates of free-flying (free) mosquitoes in a test room. However, evaluations using free mosquitoes present many complexities. The performances of 6 alternative methods with mosquitoes held in 2 different cage designs (steel wire and gauze/plastic) with and without an operating fan for air circulation were monitored in a test room through a closed-circuit television system and were compared with the currently recommended method using free mosquitoes. Results for caged mosquitoes without a fan showed a clearly delayed knockdown effect, whereas outcomes for caged mosquitoes with a fan recorded higher mortality at 24 h, compared to free mosquitoes. Among the 6 methods, cages made of gauze and plastic operating with fan wind speed at 2.5-2.8 m/sec was the only method without a significant difference in results for free mosquitoes, and therefore appears as the best alternative to assess knockdown by ambient insecticides accurately.

  20. Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

    International Nuclear Information System (INIS)

    Joudi, Khalid A.; Al-Amir, Qusay R.

    2014-01-01

    Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

  1. Illuminance: Computerized simulation

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, A

    1991-03-01

    One of the main objectives of a graphics work-station is to create images that are as realistic as possible. This paper reviews and assesses the state-of-the-art in the field of illuminance simulation. The techniques examined are: ray tracing, in which illuminance in a given ambient is calculated in an approximate way by tracing individual rays of light; the 'radiosity' (a term combining surface radiancy and reflectivity) method, based on the calculation of the ambient's thermodynamics and which considers the effects of different surface colours; progressive improvement, in which 'radiosity' is calculated step by step with increasing levels of detail. The Gouraud and Phong methods of representing the effects of shade are also compared.

  2. Analysis of different technologies of artificial illumination for production of chrysanthemum in protecting environment; Analise de diferentes tecnologias de iluminacao artificial para producao de crisantemos em ambiente protegido

    Energy Technology Data Exchange (ETDEWEB)

    David, Eduardo; Rossi, Luiz Antonio [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola. Dept. de Engenharia Agricola], Emails: eduardo.david@gr.unicamp.br, rossi@agr.unicamp.br

    2006-07-01

    In protecting environment chrysanthemum's production, the artificial illumination type used to induce the photo period, affects the growing and development of plants, as well the electric power consumed in this process of production. The most useful illumination type is by filament. Today, new artificial illumination technologies have been studied to reduce the electric power consumption. This work has been development in a commercial greenhouse with four varieties. The preliminary results have showed that the utilization of discharge lamps does not affect significantly the flower's development considering the weight and presence of flower bud. In the analyzed period, the reduction on power electricity consumption was 60,13% on the sodium-vapor lamp, 41,66% on the mercury-vapor lamp, 60,52% on the fluorescent tube lamp and 50,32% on the compact fluorescent-integrated lamp in comparison with the incandescent lamp that nowadays it is used. It shows the high intensity discharge technology (HID technology) has saved more electricity than the incandescent lamp. (author)

  3. American Illuminations

    DEFF Research Database (Denmark)

    Nye, David

    Illuminated fêtes and civic celebrations began in Renaissance Italy and spread through the courts of Europe. Their fireworks, torches, lamps, and special effects glorified the monarch, marked the birth of a prince, or celebrated military victory. Nineteenth-century Americans rejected such monarch...

  4. Hotsphere illumination

    Science.gov (United States)

    Razavi, Bahar S.; Hoang, Duyen; Liu, Shibin; Kuzyakov, Yakov

    2017-04-01

    Soils are the most heterogeneous parts of the biosphere, with an extremely high differentiation of properties and processes at all spatial and temporal scales. Importance of hotspheres- environment with abundant high microbial activity- i.e.: rhizosphere, detritusphere, biopores, spermosphere and hyphasphere calls for spatially explicit methods to illuminate distribution of microbial activities (Kuzyakov and Blagodatskaya, 2015). Zymography technique has previously been adapted to visualize the spatial dynamics of enzyme activities in rhizosphere. Here, we further developed soil zymography to obtain a higher resolution of enzyme activities by enabling direct contact of substrate-saturated membranes with soil. For the first time, we aimed at quantitative imaging of enzyme activities in various hotspheres. We calculated and compared percentage of enzymatic hotspots of four hotspheres: Spermosphere, rhizosphere, detritusphere and biopores. Spatial distribution of activities of two enzymes: β-glucosidase and phosphatase were analyzed in the spermosphere and rhizosphere of maize and lentil. Zymography has been done 3 days (spermosphere), 14 days (rhizosphere) after sowing. Further, manure was placed on surface of rhizoboxes to visualize spatio-temporal distribution of the enzyme activities in detritusphere after 25 days. Biopores were produced by earthworms (Lumbricus terrestris L.) in transparent boxes for 2 weeks and enzyme distribution were measured by zymography thereafter. The developed in situ direct soil zymography visualized the heterogeneity of enzyme activities along and across the roots. Spatial patterns of enzyme activities as a function of distance along the root demonstrated plant specific patterns of enzyme distribution: it was uniform and homogenous along the lentil roots, whereas the enzyme activities in maize rhizosphere were higher at the apical or proximal root parts. For the first time were applied "spatial point pattern analysis" to determine

  5. Diffraction analysis of customized illumination technique

    Science.gov (United States)

    Lim, Chang-Moon; Kim, Seo-Min; Eom, Tae-Seung; Moon, Seung Chan; Shin, Ki S.

    2004-05-01

    Various enhancement techniques such as alternating PSM, chrome-less phase lithography, double exposure, etc. have been considered as driving forces to lead the production k1 factor towards below 0.35. Among them, a layer specific optimization of illumination mode, so-called customized illumination technique receives deep attentions from lithographers recently. A new approach for illumination customization based on diffraction spectrum analysis is suggested in this paper. Illumination pupil is divided into various diffraction domains by comparing the similarity of the confined diffraction spectrum. Singular imaging property of individual diffraction domain makes it easier to build and understand the customized illumination shape. By comparing the goodness of image in each domain, it was possible to achieve the customized shape of illumination. With the help from this technique, it was found that the layout change would not gives the change in the shape of customized illumination mode.

  6. Fibre illumination system

    DEFF Research Database (Denmark)

    2012-01-01

    Source: EP2426402A The invention relates to a fibre illumination module and system for the collection and delivery of daylight for illumination purposes. The fibre illumination module comprises a plurality of collector elements, each collector element comprising an input fibre having a first end......-directional arrangement. The fibre illumination system comprises a fibre illumination module of the above-mentioned type. By the invention, daylight may be exploited for the illumination of remote interior spaces of buildings in order to save energy, and improve the well-being of users in both housing and working...

  7. Ambient particulate matter induces IL-8 expression through an alternative NF-kB mechanism in human airway epithelial cells

    Science.gov (United States)

    BACKGROUND: Exposure to ambient air particulate matter (PM) has been shown to increase rates of cardio-pulmonary morbidity and mortality, but the underlying mechanisms are still not well understood. OBJECTIVE: To examine signaling events involved in the expression of the inflamma...

  8. Ambient Pressure Test Rig Developed for Testing Oil-Free Bearings in Alternate Gases and Variable Pressures

    Science.gov (United States)

    Bauman, Steven W.

    1990-01-01

    The Oil-Free Turbomachinery research team at the NASA Glenn Research Center is conducting research to develop turbomachinery systems that utilize high-speed, high temperature foil (air) bearings that do not require an oil lubrication system. Such systems combine the most advanced foil bearings from industry with NASA-developed hightemperature solid-lubricant technology. New applications are being pursued, such as Oil- Free turbochargers, auxiliary power units, and turbine propulsion systems for aircraft. An Oil-Free business jet engine, for example, would be simpler, lighter, more reliable, and less costly to purchase and maintain than current engines. Another application is NASA's Prometheus mission, where gas bearings will be required for the closed-cycle turbine based power-conversion system of a nuclear power generator for deep space. To support these applications, Glenn's Oil-Free Turbomachinery research team developed the Ambient Pressure Test Rig. Using this facility, researchers can load and heat a bearing and evaluate its performance with reduced air pressure to simulate high altitude conditions. For the nuclear application, the test chamber can be purged with gases such as helium to study foil gas bearing operation in working fluids other than air.

  9. Wood's lamp illumination (image)

    Science.gov (United States)

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  10. ALTERNATIVE

    Directory of Open Access Journals (Sweden)

    HUMBERTO ESCALANTE H.

    2014-01-01

    Full Text Available En Colombia, el procesamiento agroindustrial de fique genera aproximadamente 20 800 kg de residuos/ha sembrada que corresponden a. jugo y bagazo. Estos residuos son descartados al ambiente generando problemas de contaminación. El bagazo de fique tiene un valor calorífico de 3 297.91 kcal/kg, altas concentraciones de celulosa, hemicelulosa y una relación C/N favorable para tratar este residuo mediante conversión anaerobia. Sin embargo, la presencia de lignina en el bagazo hace que se requiera un consorcio microbiano específico para llevar a cabo la degradación. En este trabajo se estudio la producción de biogás a partir del bagazo de fique, empleando como inóculo una mezcla de líquido ruminal y lodo estiércol de cerdo. Se alcanzó una producción de metano de 0.35 m3CH4/kg Sólidos Volátiles (SV adicionados durante quince días de digestión, equivalente a 1.38 kWh/kg SV adicionado, indicando que el bagazo de fique es un residuo atractivo para ser usado como fuente de energía renovable.

  11. 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

  12. Nonimaging optical illumination system

    Energy Technology Data Exchange (ETDEWEB)

    Winston, R.; Ries, H.

    2000-02-01

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source, a light reflecting surface, and a family of light edge rays defined along a reference line with the reflecting surface defined in terms of the reference line 104 as a parametric function R(t) where t is a scalar parameter position and R(t) = k(t) + Du(t) where k(t) is a parameterization of the reference line 104, and D is a distance from a point on the reference line 104 to the reflection surface 108 along the desired edge ray through the point.

  13. Tailored reflectors for illumination.

    Science.gov (United States)

    Jenkins, D; Winston, R

    1996-04-01

    We report on tailored reflector design methods that allow the placement of general illumination patterns onto a target plane. The use of a new integral design method based on the edge-ray principle of nonimaging optics gives much more compact reflector shapes by eliminating the need for a gap between the source and the reflector profile. In addition, the reflectivity of the reflector is incorporated as a design parameter. We show the performance of design for constant irradiance on a distant plane, and we show how a leading-edge-ray method may be used to achieve general illumination patterns on nearby targets.

  14. Predicting Ground Illuminance

    Science.gov (United States)

    Lesniak, Michael V.; Tregoning, Brett D.; Hitchens, Alexandra E.

    2015-01-01

    Our Sun outputs 3.85 x 1026 W of radiation, of which roughly 37% is in the visible band. It is directly responsible for nearly all natural illuminance experienced on Earth's surface, either in the form of direct/refracted sunlight or in reflected light bouncing off the surfaces and/or atmospheres of our Moon and the visible planets. Ground illuminance, defined as the amount of visible light intercepting a unit area of surface (from all incident angles), varies over 7 orders of magnitude from day to night. It is highly dependent on well-modeled factors such as the relative positions of the Sun, Earth, and Moon. It is also dependent on less predictable factors such as local atmospheric conditions and weather.Several models have been proposed to predict ground illuminance, including Brown (1952) and Shapiro (1982, 1987). The Brown model is a set of empirical data collected from observation points around the world that has been reduced to a smooth fit of illuminance against a single variable, solar altitude. It provides limited applicability to the Moon and for cloudy conditions via multiplicative reduction factors. The Shapiro model is a theoretical model that treats the atmosphere as a three layer system of light reflectance and transmittance. It has different sets of reflectance and transmittance coefficients for various cloud types.In this paper we compare the models' predictions to ground illuminance data from an observing run at the White Sands missile range (data was obtained from the United Kingdom's Meteorology Office). Continuous illuminance readings were recorded under various cloud conditions, during both daytime and nighttime hours. We find that under clear skies, the Shapiro model tends to better fit the observations during daytime hours with typical discrepancies under 10%. Under cloudy skies, both models tend to poorly predict ground illuminance. However, the Shapiro model, with typical average daytime discrepancies of 25% or less in many cases

  15. Nonimaging optical illumination system

    Science.gov (United States)

    Winston, Roland; Ries, Harald

    1996-01-01

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source 102, a light reflecting surface 108, and a family of light edge rays defined along a reference line 104 with the reflecting surface 108 defined in terms of the reference line 104 as a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line 104, and D is a distance from a point on the reference line 104 to the reflection surface 108 along the desired edge ray through the point.

  16. Multiple Illuminant Colour Estimation via Statistical Inference on Factor Graphs.

    Science.gov (United States)

    Mutimbu, Lawrence; Robles-Kelly, Antonio

    2016-08-31

    This paper presents a method to recover a spatially varying illuminant colour estimate from scenes lit by multiple light sources. Starting with the image formation process, we formulate the illuminant recovery problem in a statistically datadriven setting. To do this, we use a factor graph defined across the scale space of the input image. In the graph, we utilise a set of illuminant prototypes computed using a data driven approach. As a result, our method delivers a pixelwise illuminant colour estimate being devoid of libraries or user input. The use of a factor graph also allows for the illuminant estimates to be recovered making use of a maximum a posteriori (MAP) inference process. Moreover, we compute the probability marginals by performing a Delaunay triangulation on our factor graph. We illustrate the utility of our method for pixelwise illuminant colour recovery on widely available datasets and compare against a number of alternatives. We also show sample colour correction results on real-world images.

  17. 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....

  18. Illumination and radiative cooling

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Shanhui; Raman, Aaswath Pattabhi; Zhu, Linxiao; Rephaeli, Eden

    2018-03-20

    Aspects of the present disclosure are directed to providing and/or controlling electromagnetic radiation. As may be implemented in accordance with one or more embodiments, an apparatus includes a first structure that contains an object, and a second structure that is transparent at solar wavelengths and emissive in the atmospheric electromagnetic radiation transparency window. The second structure operates with the first structure to pass light into the first structure for illuminating the object, and to radiatively cool the object while preserving the object's color.

  19. Parallel hierarchical global illumination

    Energy Technology Data Exchange (ETDEWEB)

    Snell, Quinn O. [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    Solving the global illumination problem is equivalent to determining the intensity of every wavelength of light in all directions at every point in a given scene. The complexity of the problem has led researchers to use approximation methods for solving the problem on serial computers. Rather than using an approximation method, such as backward ray tracing or radiosity, the authors have chosen to solve the Rendering Equation by direct simulation of light transport from the light sources. This paper presents an algorithm that solves the Rendering Equation to any desired accuracy, and can be run in parallel on distributed memory or shared memory computer systems with excellent scaling properties. It appears superior in both speed and physical correctness to recent published methods involving bidirectional ray tracing or hybrid treatments of diffuse and specular surfaces. Like progressive radiosity methods, it dynamically refines the geometry decomposition where required, but does so without the excessive storage requirements for ray histories. The algorithm, called Photon, produces a scene which converges to the global illumination solution. This amounts to a huge task for a 1997-vintage serial computer, but using the power of a parallel supercomputer significantly reduces the time required to generate a solution. Currently, Photon can be run on most parallel environments from a shared memory multiprocessor to a parallel supercomputer, as well as on clusters of heterogeneous workstations.

  20. Ambient Space and Ambient Sensation

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central...... aspect of the aesthetization of modern culture in general, from architecture, transport and urbanized lifeforms to film, sound art, installation art and digital environments. This presentation will discuss the key aspects of ambient aesthetization, including issues such as objectlessness...

  1. Split-illumination electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Tanigaki, Toshiaki; Aizawa, Shinji; Suzuki, Takahiro; Park, Hyun Soon [Advanced Science Institute, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Inada, Yoshikatsu [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Matsuda, Tsuyoshi [Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Taniyama, Akira [Corporate Research and Development Laboratories, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891 (Japan); Shindo, Daisuke [Advanced Science Institute, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Tonomura, Akira [Advanced Science Institute, RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Okinawa Institute of Science and Technology, Graduate University, Onna-son, Okinawa 904-0495 (Japan); Central Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395 (Japan)

    2012-07-23

    We developed a split-illumination electron holography that uses an electron biprism in the illuminating system and two biprisms (applicable to one biprism) in the imaging system, enabling holographic interference micrographs of regions far from the sample edge to be obtained. Using a condenser biprism, we split an electron wave into two coherent electron waves: one wave is to illuminate an observation area far from the sample edge in the sample plane and the other wave to pass through a vacuum space outside the sample. The split-illumination holography has the potential to greatly expand the breadth of applications of electron holography.

  2. Split-illumination electron holography

    International Nuclear Information System (INIS)

    Tanigaki, Toshiaki; Aizawa, Shinji; Suzuki, Takahiro; Park, Hyun Soon; Inada, Yoshikatsu; Matsuda, Tsuyoshi; Taniyama, Akira; Shindo, Daisuke; Tonomura, Akira

    2012-01-01

    We developed a split-illumination electron holography that uses an electron biprism in the illuminating system and two biprisms (applicable to one biprism) in the imaging system, enabling holographic interference micrographs of regions far from the sample edge to be obtained. Using a condenser biprism, we split an electron wave into two coherent electron waves: one wave is to illuminate an observation area far from the sample edge in the sample plane and the other wave to pass through a vacuum space outside the sample. The split-illumination holography has the potential to greatly expand the breadth of applications of electron holography.

  3. Det ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Om begrebet "det ambiente", der beskriver, hvad der sker, når vi fornemmer baggrundsmusikkens diskrete beats, betragter udsigten gennem panoramavinduet eller tager 3D-brillerne på og læner os tilbage i biografsædet. Bogen analyserer, hvorfan ambiente oplevelser skabes, og hvilke konsekvenser det...

  4. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under

  5. Predicting daylight illuminance on inclined surfaces using sky luminance data

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.H.W.; Lau, C.C.S.; Lam, J.C. [City University of Hong Kong, Kowloon (China). Dept. of Building and Construction

    2005-07-01

    Daylight illuminance, particularly on vertical surfaces, plays a major role in determining and evaluating the daylighting performance of a building. In many parts of the world, however, the basic daylight illuminance data for various vertical planes are not always readily available. The usual method to obtain diffuse illuminance on tilted planes would be based on inclined surface models using data from the horizontal measurements. Alternatively, the diffuse illuminance on a sloping plane can be computed by integrating the luminance distribution of the sky 'seen' by the plane. This paper presents an approach to estimate the vertical outdoor illuminance from sky luminance data and solar geometry. Sky luminance data recorded from January 1999 to December 2001 in Hong Kong and generated by two well-known sky luminance models (Kittler and Perez) were used to compute the outdoor illuminance for the four principal vertical planes (N, E, S and W). The performance of this approach was evaluated against data measured in the same period. Statistical analysis indicated that using sky luminance distributions to predict outdoor illuminance can give reasonably good agreement with measured data for all vertical surfaces. The findings provide an accurate alternative to determine the amount of daylight on vertical as well as other inclined surfaces when sky luminance data are available. (author)

  6. Det Ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Det ambiente er iscenesættelsen af en karakteristisk sanseoplevelse, der er kendetegnet ved fornemmelsen af at være omgivet. I dag bliver begrebet om det ambiente mest anvendt i forbindelse med musikgenren ’ambient musik’. Det ambiente er dog ikke essentielt knyttet til det musikalske, men må...... forstås som et betydeligt bredere fænomen i den moderne æstetiske kultur, der spiller en væsentlig rolle i oplevelsen af moderne transportformer, arkitektur, film, lydkunst, installationskunst og digitale multimedieiscenesættelser. En forståelse af det ambiente er derfor centralt for forståelsen af en...... moderne æstetiseret oplevelseskultur i almindelighed. Da det ambiente ikke hidtil har været gjort til genstand for en mere indgående teoretisk behandling, er der dog stor usikkerhed omkring, hvad fænomenet overhovedet indebærer. Hovedformålet med Det ambiente – Sansning, medialisering, omgivelse er derfor...

  7. Biological Effects Of Artificial Illumination

    Science.gov (United States)

    Corth, Richard

    1980-10-01

    We are increasingly being warned of the possible effects of so called "polluted" light, that is light that differs in spectral content from that of sunlight. We should be concerned, we are told, because all animals and plants have evolved under this natural daylight and therefore any difference between that illuminant and the artificial illuminants that are on the market today, is suspect. The usual presentation of the differences between the sunlight and the artificial illuminants are as shown in Figure 1. Here we are shown the spectral power distribution of sunlight and Cool White fluorescent light. The spectral power distributions of each have been normalized to some convenient wavelength so that each can be seen and easily compared on the same figure. But this presentation is misleading for one does not experience artificial illuminants at the same intensity as one experiences sunlight. Sunlight intensities are ordinarily found to be in the 8000 to 10,000 footcandle range whereas artificial illuminants are rarely experienced at intensity levels greater than 100 footcandles. Therefore a representative difference between the two types of illumination conditions is more accurately represented as in Figure 2. Thus if evolutionary adaptations require that humans and other animals be exposed to sunlight to ensure wellbeing, it is clear that one must be exposed to sunlight intensities. It is not feasible to expect that artificially illuminated environments will be lit to the same intensity as sunlight

  8. Laser sources for object illumination

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, G.F. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    The considerations which formulate the specifications for a laser illuminator are explained, using the example of an underwater object. Depending on the parameters which define the scenario, widely varying laser requirements result.

  9. Periodismo ambiental

    Directory of Open Access Journals (Sweden)

    Lucía Lemos

    2015-01-01

    Full Text Available Los periodistas toman el tema del medio ambiente cada vez más en serio. El uso de temas relacionados con el medio ambiente, debe estar ligado al análisis socio-económico y a las posibilidades de comunicación y educación de diferentes regiones del mundo. A continuación se presenta un resumen de la situación ambiental, las acciones de prensa y comunicación que se llevan a cabo en América Central (Panamá, El Salvador, Costa Rica y en Sudamérica Brasil,Colombia, Chile, México, y Perú. Se concluye en la necesidad de formar hábitos ecológicos. Los comunicadores deben presentar soluciones a los problemas, fomentar campañas comunes, compartir información y velar por el ambiente ambiente para que las generaciones futuras no tengan que perecer.

  10. Strawberry farming with lichens: an alternative to the environment | Cultivo de morangos com líquens: uma alternativa para o ambiente

    Directory of Open Access Journals (Sweden)

    José Machado

    2016-05-01

    Full Text Available The strawberry culture demand for labor, it requires special care to prevent pest problems. Its cultivation is characterized by indiscriminate use of pesticides, which leads researchers to seek more natural alternatives for improving soil conditions, and decreased use of chemicals. In this context, lichens can be a viable alternative, since its properties in modifying the chemical composition of the soil, addition of antimicrobial action and their insecticidal substances. The aim of work is to inform about the strawberry cultivation your climate conditions and possible use of lichens in your cultivation.

  11. Ambient Utopia

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; Bosse, Tibor

    2012-01-01

    his chapter presents an analysis of the ambitions that lie behind the concept of Ambient Intelligence as it is presented by the advocates and researchers working in the field. In particular it looks at the ideas regarding the forms of natural and intuitive forms of interaction that are envisaged –

  12. The influence of ambient light on the driver

    Science.gov (United States)

    Klinger, Karsten D.; Lemmer, Uli

    2008-04-01

    Increasingly, cars are fitted with interior ambient lighting which is switched on while driving. This special kind of interior light emphasizes the interior design of the car, it makes a car look special and gives the buyers a new option to personalize their automobiles. But how does ambient interior light influence the driver? We conducted a series of over 50 tests to study the influence of interior ambient light on contrast perception under different illumination levels, colors and positions of the illuminated areas. Our tests show that in many cases the ambient lighting can improve the visual contrast for seeing objects in the headlamp beam. But the test persons mentioned that the tested brightness looked too bright and that they felt glared. The measured values instead proved that no disability glare exists. Therefore, provided that the drivers can adjust the intensity of the ambient light to avoid glare, the ambient light has no negative effect on the drivers' contrast perception.

  13. Photo-illuminated diamond as a solid-state source of solvated electrons in water for nitrogen reduction.

    Science.gov (United States)

    Zhu, Di; Zhang, Linghong; Ruther, Rose E; Hamers, Robert J

    2013-09-01

    The photocatalytic reduction of N₂ to NH₃ is typically hampered by poor binding of N₂ to catalytic materials and by the very high energy of the intermediates involved in this reaction. Solvated electrons directly introduced into the reactant solution can provide an alternative pathway to overcome such limitations. Here we demonstrate that illuminated hydrogen-terminated diamond yields facile electron emission into water, thus inducing reduction of N₂ to NH₃ at ambient temperature and pressure. Transient absorption measurements at 632 nm reveal the presence of solvated electrons adjacent to the diamond after photoexcitation. Experiments using inexpensive synthetic diamond samples and diamond powder show that photocatalytic activity is strongly dependent on the surface termination and correlates with the production of solvated electrons. The use of diamond to eject electrons into a reactant liquid represents a new paradigm for photocatalytic reduction, bringing electrons directly to reactants without requiring molecular adsorption to the surface.

  14. Dynamic thermal model of photovoltaic cell illuminated by laser beam

    Science.gov (United States)

    Liu, Xiaoguang; Hua, Wenshen; Guo, Tong

    2015-07-01

    Photovoltaic cell is one of the most important components of laser powered unmanned aerial vehicle. Illuminated by high power laser beam, photovoltaic cell temperature increases significantly, which leads to efficiency drop, or even physical damage. To avoid such situation, the temperature of photovoltaic cell must be predicted precisely. A dynamic thermal model of photovoltaic cell is established in this paper, and the relationships between photovoltaic cell temperature and laser power, wind speed, ambient temperature are also analyzed. Simulation result indicates that illuminated by a laser beam, the temperature of photovoltaic cell rises gradually and reach to a constant maximum value. There is an approximately linear rise in photovoltaic cell temperature as the laser flux gets higher. The higher wind speed is, the stronger forced convection is, and then the lower photovoltaic cell temperature is. But the relationship between photovoltaic cell temperature and wind speed is not linear. Photovoltaic cell temperature is proportional to the ambient temperature. For each increase of 1 degree of ambient temperature, there is approximate 1 degree increase in photovoltaic cell temperature. The result will provide fundamentals to take reasonable measures to control photovoltaic cell temperature.

  15. Ambient diagnostics

    CERN Document Server

    Cai, Yang

    2014-01-01

    Part I. FundamentalsIntroductionWhat is Ambient Diagnostics?Diagnostic ModelsMultimedia IntelligenceCrowd SourcingSoft SensorsScience of SimplicityPersonal DiagnosesBasic AlgorithmsBasic ToolsSummaryProblemsTransformationEarly Discoveries of Heartbeat PatternsTransforms, Features, and AttributesSequential FeaturesSpatiotemporal FeaturesShape FeaturesImagery FeaturesFrequency Domain FeaturesMulti-Resolution FeaturesSummaryProblemsPattern RecognitionSimilarities and DistancesClustering MethodsClassification MethodsClassifier Accuracy MeasuresSummaryProblemsPart II. Multimedia IntelligenceSound RecognitionMicrophone AppsModern Acoustic Transducers (Microphones)Frequency Response CharacteristicsDigital Audio File FormatsHeart Sound SensingLung Sound SensingSnore MeterSpectrogram (STFT)Ambient Sound AnalysisSound RecognitionRecognizing Asthma SoundPeak ShiftFeature CompressionRegroupingNoise IssuesFuture ApplicationsSummaryProblemsColor SensorsColor SensingHuman Color VisionColor SensorsColor Matching ExperimentsC...

  16. Achieving uniform efficient illumination with multiple asymmetric compound parabolic luminaires

    Science.gov (United States)

    Gordon, Jeffrey M.; Kashin, Peter

    1994-01-01

    Luminaire designs based on multiple asymmetric nonimaging compound parabolic reflectors are proposed for 2-D illumination applications that require highly uniform far-field illuminance, while ensuring maximal lighting efficiency and sharp angular cutoffs. The new designs derive from recent advances in nonimaging secondary concentrators for line-focus solar collectors. The light source is not treated as a single entity, but rather is divided into two or more separate adjoining sources. An asymmetric compound parabolic luminaire is then designed around each half-source. Attaining sharp cutoffs requires relatively large reflectors. However, severe truncation of the reflectors renders these devices as compact as many conventional luminaires, at the penalty of a small fraction of the radiation being emitted outside the nominal cutoff. The configurations that maximize the uniformity of far-field illuminance offer significant improvements in flux homogeneity relative to alternative designs to date.

  17. Laser illuminated flat panel display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T.

    1995-12-31

    A 10 inch laser illuminated flat panel Planar Optic Display (POD) screen has been constructed and tested. This POD screen technology is an entirely new concept in display technology. Although the initial display is flat and made of glass, this technology lends itself to applications where a plastic display might be wrapped around the viewer. The display screen is comprised of hundreds of planar optical waveguides where each glass waveguide represents a vertical line of resolution. A black cladding layer, having a lower index of refraction, is placed between each waveguide layer. Since the cladding makes the screen surface black, the contrast is high. The prototype display is 9 inches wide by 5 inches high and approximately I inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  18. A new radiometric unit of measure to characterize SWIR illumination

    Science.gov (United States)

    Richards, A.; Hübner, M.

    2017-05-01

    We propose a new radiometric unit of measure we call the `swux' to unambiguously characterize scene illumination in the SWIR spectral band between 0.8μm-1.8μm, where most of the ever-increasing numbers of deployed SWIR cameras (based on standard InGaAs focal plane arrays) are sensitive. Both military and surveillance applications in the SWIR currently suffer from a lack of a standardized SWIR radiometric unit of measure that can be used to definitively compare or predict SWIR camera performance with respect to SNR and range metrics. We propose a unit comparable to the photometric illuminance lux unit; see Ref. [1]. The lack of a SWIR radiometric unit becomes even more critical if one uses lux levels to describe SWIR sensor performance at twilight or even low light condition, since in clear, no-moon conditions in rural areas, the naturally-occurring SWIR radiation from nightglow produces a much higher irradiance than visible starlight. Thus, even well-intentioned efforts to characterize a test site's ambient illumination levels in the SWIR band may fail based on photometric instruments that only measure visible light. A study of this by one of the authors in Ref. [2] showed that the correspondence between lux values and total SWIR irradiance in typical illumination conditions can vary by more than two orders of magnitude, depending on the spectrum of the ambient background. In analogy to the photometric lux definition, we propose the SWIR irradiance equivalent `swux' level, derived by integration over the scene SWIR spectral irradiance weighted by a spectral sensitivity function S(λ), a SWIR analog of the V(λ) photopic response function.

  19. Tolerancing a lens for LED uniform illumination

    Science.gov (United States)

    Ryu, Jieun; Sasian, Jose

    2017-08-01

    A method to evaluate tolerance sensitivities for lenses used to produce uniform illumination is presented. Closed form surfaces are used to define optical surfaces and relative illumination is calculated from light etendue considerations.

  20. Illumination influences working memory: an EEG study.

    Science.gov (United States)

    Park, Jin Young; Min, Byoung-Kyong; Jung, Young-Chul; Pak, Hyensou; Jeong, Yeon-Hong; Kim, Eosu

    2013-09-05

    Illumination conditions appear to influence working efficacy in everyday life. In the present study, we obtained electroencephalogram (EEG) correlates of working-memory load, and investigated how these waveforms are modulated by illumination conditions. We hypothesized that illumination conditions may affect cognitive performance. We designed an EEG study to monitor and record participants' EEG during the Sternberg working memory task under four different illumination conditions. Illumination conditions were generated with a factorial design of two color-temperatures (3000 and 7100 K) by two illuminance levels (150 and 700 lx). During a working memory task, we observed that high illuminance led to significantly lower frontal EEG theta activity than did low illuminance. These differences persisted despite no significant difference in task performance between illumination conditions. We found that the latency of an early event-related potential component, such as N1, was significantly modulated by the illumination condition. The fact that the illumination condition affects brain activity but not behavioral performance suggests that the lighting conditions used in the present study did not influence the performance stage of behavioral processing. Nevertheless, our findings provide objective evidence that illumination conditions modulate brain activity. Further studies are necessary to refine the optimal lighting parameters for facilitating working memory. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Quantum Illumination with Noiseless Linear Amplifier

    International Nuclear Information System (INIS)

    Zhang Sheng-Li; Wang -Kun; Guo Jian-Sheng; Shi Jian-Hong

    2015-01-01

    Quantum illumination, that is, quantum target detection, is to detect the potential target with two-mode quantum entangled state. For a given transmitted energy, the quantum illumination can achieve a target-detection probability of error much lower than the illumination scheme without entanglement. We investigate the usefulness of noiseless linear amplification (NLA) for quantum illumination. Our result shows that NLA can help to substantially reduce the number of quantum entangled states collected for joint measurement of multi-copy quantum state. Our analysis on the NLA-assisted scheme could help to develop more efficient schemes for quantum illumination. (paper)

  2. The draft genome of a termite illuminates alternative social organization

    Science.gov (United States)

    Termites have substantial economic and ecological impact worldwide. They are also the oldest organisms living in complex societies, having evolved a caste system independent of that of eusocial Hymenoptera (ants, bees and wasps). Here we provide the first genome sequence for a termite, Zootermopsis ...

  3. The importance of illumination in nest site choice and nest characteristics of cavity nesting birds.

    Science.gov (United States)

    Podkowa, Paweł; Surmacki, Adrian

    2017-05-02

    Light has a significant impact on many aspects of avian biology, physiology and behaviour. An increasing number of studies show that illumination may positively influences birds' offspring fitness by e.g. acceleration of embryo development, stimulation of skeleton growth or regulation of circadian rhythm. Because nest cavities have especially low illumination, suitable light levels may be especially important for species which nest there. We may therefore expect that birds breeding in relatively dim conditions should prefer brighter nest sites and/or evolve behavioral mechanisms to secure sufficient light levels in the nest. Using nest boxes with modified internal illumination, we experimentally tested whether light regime is a cue for nest site selection of secondary cavity-nesting species. Additionally, we investigated whether nest building strategies are tuned to internal illumination. Our results demonstrate that, nest boxes with elevated illumination were chosen twice as often as dark nest boxes. Moreover, birds built higher nests in dark nest boxes than birds in boxes with elevated illumination, which suggests a mechanism of compensating for low light conditions. Our results provide the first experimental support for the idea that nest site choice and nest building behaviour in cavity-nesting birds are influenced by ambient illumination.

  4. Real time global illumination using the GPU

    OpenAIRE

    Bengtsson, Morgan

    2010-01-01

    Global illumination is an important factor when striving for photo realism in computergraphics. This thesis describes why this is the case, and why global illumination is considered acomplex problem to solve. The problem becomes even more demanding when considering realtime purposes. Resent research has proven it possible to produce global illumination in realtime. Therefore the subject of this thesis is to compare and evaluate a number of those methods. An implementation is presented based o...

  5. Solar Illumination Control of the Polar Wind

    Science.gov (United States)

    Maes, L.; Maggiolo, R.; De Keyser, J.; André, M.; Eriksson, A. I.; Haaland, S.; Li, K.; Poedts, S.

    2017-11-01

    Polar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 RE. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density.

  6. Tomographic Particle Image Velocimetry using Pulsed, High Power LED Volume Illumination

    OpenAIRE

    Buchmann, N. A.; Willert, C.; Soria, J.

    2011-01-01

    This paper investigates the use of high-power light emitting diode (LED) illumination in Particle Image Velocimetry (PIV) as an alternative to traditional laser-based illumination. The solid-state LED devices can provide averaged radiant power in excess of 10W and by operating the LEDs with short current pulses, considerably higher than in continuous operation, light pulses of sufficient energy suitable for imaging micron-sized particles can be generated. The feasibility of this LED-based ill...

  7. Illumination correction in psoriasis lesions images

    DEFF Research Database (Denmark)

    Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær

    2003-01-01

    An approach to automatically correct illumination problems in dermatological images is presented. The illumination function is estimated after combining the thematic map indicating skin-produced by an automated classification scheme- with the dermatological image data. The user is only required t...

  8. Weld pool visual sensing without external illumination

    DEFF Research Database (Denmark)

    Liu, Jinchao; Fan, Zhun; Olsen, Soren Ingvor

    2011-01-01

    Visual sensing in arc welding has become more and more important, but still remains challenging because of the harsh environment with extremely strong illumination from the arc. This paper presents a low-cost camera-based sensor system, without using external Illumination, but nevertheless able...

  9. Anisotropic Density Estimation in Global Illumination

    DEFF Research Database (Denmark)

    Schjøth, Lars

    2009-01-01

    Density estimation employed in multi-pass global illumination algorithms gives cause to a trade-off problem between bias and noise. The problem is seen most evident as blurring of strong illumination features. This thesis addresses the problem, presenting four methods that reduce both noise...

  10. Illuminant-adaptive color reproduction for mobile display

    Science.gov (United States)

    Kim, Jong-Man; Park, Kee-Hyon; Kwon, Oh-Seol; Cho, Yang-Ho; Ha, Yeong-Ho

    2006-01-01

    This paper proposes an illuminant-adaptive reproduction method using light adaptation and flare conditions for a mobile display. Mobile displays, such as PDAs and cellular phones, are viewed under various lighting conditions. In particular, images displayed in daylight are perceived as quite dark due to the light adaptation of the human visual system, as the luminance of a mobile display is considerably lower than that of an outdoor environment. In addition, flare phenomena decrease the color gamut of a mobile display by increasing the luminance of dark areas and de-saturating the chroma. Therefore, this paper presents an enhancement method composed of lightness enhancement and chroma compensation. First, the ambient light intensity is measured using a lux-sensor, then the flare is calculated based on the reflection ratio of the display device and the ambient light intensity. The relative cone response is nonlinear to the input luminance. This is also changed by the ambient light intensity. Thus, to improve the perceived image, the displayed luminance is enhanced by lightness linearization. In this paper, the image's luminance is transformed by linearization of the response to the input luminance according to the ambient light intensity. Next, the displayed image is compensated according to the physically reduced chroma, resulting from flare phenomena. The reduced chroma value is calculated according to the flare for each intensity. The chroma compensation method to maintain the original image's chroma is applied differently for each hue plane, as the flare affects each hue plane differently. At this time, the enhanced chroma also considers the gamut boundary. Based on experimental observations, the outer luminance-intensity generally ranges from 1,000 lux to 30,000 lux. Thus, in the case of an outdoor environment, i.e. greater than 1,000 lux, this study presents a color reproduction method based on an inverse cone response curve and flare condition. Consequently

  11. Chromatic illumination discrimination ability reveals that human colour constancy is optimised for blue daylight illuminations.

    Directory of Open Access Journals (Sweden)

    Bradley Pearce

    Full Text Available The phenomenon of colour constancy in human visual perception keeps surface colours constant, despite changes in their reflected light due to changing illumination. Although colour constancy has evolved under a constrained subset of illuminations, it is unknown whether its underlying mechanisms, thought to involve multiple components from retina to cortex, are optimised for particular environmental variations. Here we demonstrate a new method for investigating colour constancy using illumination matching in real scenes which, unlike previous methods using surface matching and simulated scenes, allows testing of multiple, real illuminations. We use real scenes consisting of solid familiar or unfamiliar objects against uniform or variegated backgrounds and compare discrimination performance for typical illuminations from the daylight chromaticity locus (approximately blue-yellow and atypical spectra from an orthogonal locus (approximately red-green, at correlated colour temperature 6700 K, all produced in real time by a 10-channel LED illuminator. We find that discrimination of illumination changes is poorer along the daylight locus than the atypical locus, and is poorest particularly for bluer illumination changes, demonstrating conversely that surface colour constancy is best for blue daylight illuminations. Illumination discrimination is also enhanced, and therefore colour constancy diminished, for uniform backgrounds, irrespective of the object type. These results are not explained by statistical properties of the scene signal changes at the retinal level. We conclude that high-level mechanisms of colour constancy are biased for the blue daylight illuminations and variegated backgrounds to which the human visual system has typically been exposed.

  12. The Aesthetics of the Ambient Video Experience

    Directory of Open Access Journals (Sweden)

    Jim Bizzocchi

    2008-01-01

    Full Text Available Ambient Video is an emergent cultural phenomenon, with roots that go deeply into the history of experimental film and video art. Ambient Video, like Brian Eno's ambient music, is video that "must be as easy to ignore as notice" [9]. This minimalist description conceals the formidable aesthetic challenge that faces this new form. Ambient video art works will hang on the walls of our living rooms, corporate offices, and public spaces. They will play in the background of our lives, living video paintings framed by the new generation of elegant, high-resolution flat-panel display units. However, they cannot command attention like a film or television show. They will patiently play in the background of our lives, yet they must always be ready to justify our attention in any given moment. In this capacity, ambient video works need to be equally proficient at rewarding a fleeting glance, a more direct look, or a longer contemplative gaze. This paper connects a series of threads that collectively illuminate the aesthetics of this emergent form: its history as a popular culture phenomenon, its more substantive artistic roots in avant-garde cinema and video art, its relationship to new technologies, the analysis of the viewer's conditions of reception, and the work of current artists who practice within this form.

  13. Plane parallel radiance transport for global illumination in vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Max, N.; Mobley, C.; Keating, B.; Wu, E.H.

    1997-01-05

    This paper applies plane parallel radiance transport techniques to scattering from vegetation. The leaves, stems, and branches are represented as a volume density of scattering surfaces, depending only on height and the vertical component of the surface normal. Ordinary differential equations are written for the multiply scattered radiance as a function of the height above the ground, with the sky radiance and ground reflectance as boundary conditions. They are solved using a two-pass integration scheme to unify the two-point boundary conditions, and Fourier series for the dependence on the azimuthal angle. The resulting radiance distribution is used to precompute diffuse and specular `ambient` shading tables, as a function of height and surface normal, to be used in rendering, together with a z-buffer shadow algorithm for direct solar illumination.

  14. An Asynchronous Cellular Automata-Based Adaptive Illumination Facility

    Science.gov (United States)

    Bandini, Stefania; Bonomi, Andrea; Vizzari, Giuseppe; Acconci, Vito

    The term Ambient Intelligence refers to electronic environments that are sensitive and responsive to the presence of people; in the described scenario the environment itself is endowed with a set of sensors (to perceive humans or other physical entities such as dogs, bicycles, etc.), interacting with a set of actuators (lights) that choose their actions (i.e. state of illumination) in an attempt improve the overall experience of these users. The model for the interaction and action of sensors and actuators is an asynchronous Cellular Automata (CA) with memory, supporting a self-organization of the system as a response to the presence and movements of people inside it. The paper will introduce the model, as well as an ad hoc user interface for the specification of the relevant parameters of the CA transition rule that determines the overall system behaviour.

  15. Optical design applications for enhanced illumination performance

    Science.gov (United States)

    Gilray, Carl; Lewin, Ian

    1995-08-01

    Nonimaging optical design techniques have been applied in the illumination industry for many years. Recently however, powerful software has been developed which allows accurate simulation and optimization of illumination devices. Wide experience has been obtained in using such design techniques for practical situations. These include automotive lighting where safety is of greatest importance, commercial lighting systems designed for energy efficiency, and numerous specialized applications. This presentation will discuss the performance requirements of a variety of illumination devices. It will further cover design methodology and present a variety of examples of practical applications for enhanced system performance.

  16. Near spherical illumination of ion-beam and laser targets

    International Nuclear Information System (INIS)

    Mark, J.W.K.

    1985-01-01

    A procedure is developed for reducing energy-deposition asymmetry in spherical targets driven directly by ion or laser beams. This work is part of a strategy for achieving illumination symmetry in such targets, which is proposed as an alternative to those in the literature. This strategy allows an axially symmetric placement of beamlets, which would be convenient for some driven or reactor scenarios. It also allows the use of beam currents or energy fluxes and beam transverse profiles to help reduce deposition asymmetry with fewer beamlets. In the ideal limit of thin deposition layers and controlled beam profiles, at most six beamlets are needed for target symmetry

  17. Color constancy by characterization of illumination chromaticity

    Science.gov (United States)

    Nikkanen, Jarno T.

    2011-05-01

    Computational color constancy algorithms play a key role in achieving desired color reproduction in digital cameras. Failure to estimate illumination chromaticity correctly will result in invalid overall colour cast in the image that will be easily detected by human observers. A new algorithm is presented for computational color constancy. Low computational complexity and low memory requirement make the algorithm suitable for resource-limited camera devices, such as consumer digital cameras and camera phones. Operation of the algorithm relies on characterization of the range of possible illumination chromaticities in terms of camera sensor response. The fact that only illumination chromaticity is characterized instead of the full color gamut, for example, increases robustness against variations in sensor characteristics and against failure of diagonal model of illumination change. Multiple databases are used in order to demonstrate the good performance of the algorithm in comparison to the state-of-the-art color constancy algorithms.

  18. Iterative Adaptive Sampling For Accurate Direct Illumination

    National Research Council Canada - National Science Library

    Donikian, Michael

    2004-01-01

    This thesis introduces a new multipass algorithm, Iterative Adaptive Sampling, for efficiently computing the direct illumination in scenes with many lights, including area lights that cause realistic soft shadows...

  19. Catalyzed reactions at illuminated semiconductor interfaces

    International Nuclear Information System (INIS)

    Wrighton, M.S.

    1984-01-01

    Many desirable minority carrier chemical redox processes are too slow to compete with e - -h + recombination at illuminated semiconductor/liquid electrolyte junction interfaces. Reductions of H 2 O to H 2 or CO 2 to compounds having C--H bonds are too slow to compete with e - -h + recombination at illuminated p-type semiconductors, for example. Approaches to improve the rate of the desired processes involving surface modification techniques are described. Photoanodes are plagued by the additional problem of oxidative decomposition under illumination with > or =E/sub g/ illumination. The photo-oxidation of Cl - , Br - , and H 2 O is considered to illustrate the concepts involved. Proof of concept experiments establish that catalysis can be effective in dramatically improving direct solar fuel production; efficiencies of >10% have been demonstrated

  20. Atmosphere and Ambient Space

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Atmosphere and Ambient Space This paper explores the relation between atmosphere and ambient space. Atmosphere and ambient space share many salient properties. They are both ontologically indeterminate, constantly varying and formally diffuse and they are both experienced as a subtle, non......-signifying property of a given space. But from a certain point of view, the two concepts also designate quite dissimilar experiences of space. To be ’ambient’ means to surround. Accordingly, ambient space is that space, which surrounds something or somebody. (Gibson 1987: 65) Since space is essentially...... of a surrounding character, all space can thus be described as having a fundamentally ambient character. So what precisely is an ambient space, then? As I will argue in my presentation, ambient space is a sensory effect of spatiality when a space is experienced as being particularly surrounding: a ‘space effect...

  1. Light-Emitting Diode-Based Illumination System for In Vitro Photodynamic Therapy

    Directory of Open Access Journals (Sweden)

    Defu Chen

    2012-01-01

    Full Text Available The aim of this study is to develop a light-emitting diode- (LED- based illumination system that can be used as an alternative light source for in vitro photodynamic therapy (PDT. This illumination system includes a red LED array composed of 70 LEDs centered at 643 nm, an air-cooling unit, and a specific-designed case. The irradiance as a function of the irradiation distance between the LED array and the sample, the homogeneity and stability of irradiation, and the effect of long-time irradiation on culture medium temperature were characterized. Furthermore, the survival rate of the CNE1 cells that sensitized with 5-aminolevulinic acid after PDT treatment was evaluated to demonstrate the efficiency of the new LED-based illumination system. The obtained results show that the LED-based illumination system is a promising light source for in vitro PDT that performed in standard multiwell plate.

  2. Spiritual Art: A Study of Illuminated Drawings

    Directory of Open Access Journals (Sweden)

    Fatemeh Kateb

    2017-12-01

    Full Text Available Illumination can be seen as a collection of exquisite and novel designs that painters and illumination-workers use to make religious, scientific, cultural, historical, and other collections of work beautiful. The professionals of illumination use these techniques in books to beautifully virtualize the golden pages of the eternal literature and the religious texts of their homeland. In this way, the sides and margins of the pages are decorated with designs of Islimi (arabesque branches, stems, flowers, and Cathay (Khataei leaves. Illuminations like paintings have various schools and periods, such as the Seljuk, Bukhara, Timurid, Safavid, Qajar schools, with further branches within each school. The illuminations of different periods represent the states and spirits of those eras. However, the illustrated paintings have been performed in the primary state in each school and era with some minor differences in colors and designs, and it can be said that the basis of the illustrated designs are three geometric shapes of the square, circle and triangle, and the combination of these three shapes. In this article, we try to study illumination drawings in terms of the spiritual dimension and its effect on the soul and psych. Furthermore; we will study the spiritual nature of the motifs in order to achieve a deeper understanding of the spirit of Islamic art.

  3. AN ILLUMINATION INVARIANT TEXTURE BASED FACE RECOGNITION

    Directory of Open Access Journals (Sweden)

    K. Meena

    2013-11-01

    Full Text Available Automatic face recognition remains an interesting but challenging computer vision open problem. Poor illumination is considered as one of the major issue, since illumination changes cause large variation in the facial features. To resolve this, illumination normalization preprocessing techniques are employed in this paper to enhance the face recognition rate. The methods such as Histogram Equalization (HE, Gamma Intensity Correction (GIC, Normalization chain and Modified Homomorphic Filtering (MHF are used for preprocessing. Owing to great success, the texture features are commonly used for face recognition. But these features are severely affected by lighting changes. Hence texture based models Local Binary Pattern (LBP, Local Derivative Pattern (LDP, Local Texture Pattern (LTP and Local Tetra Patterns (LTrPs are experimented under different lighting conditions. In this paper, illumination invariant face recognition technique is developed based on the fusion of illumination preprocessing with local texture descriptors. The performance has been evaluated using YALE B and CMU-PIE databases containing more than 1500 images. The results demonstrate that MHF based normalization gives significant improvement in recognition rate for the face images with large illumination conditions.

  4. La evaluación alternativa y autentica en los ambientes de aprendizaje híbridos y a distancia / The alternative and authentique evaluation in the hybrid and distance learning environments

    Directory of Open Access Journals (Sweden)

    Alejandra Fernández

    2017-12-01

    Full Text Available La evaluación del rendimiento es uno de los procesos críticos en la educación, que amerita profundizar la investigación y práctica, para hacer su aplicación más pedagógica y menos hacia el uso de tareas irrelevantes y a la medición, cuya aplicación al rendimiento de los alumnos persiste tanto en la educación presencial, como en los ambientes educativos híbridos y a distancia. Varios factores inciden en esta problemática como son: el aprecio institucional por la evaluación tradicional, la dificultad de evaluar en situaciones de aprendizaje con narrativas hibridas, el énfasis en la aplicación de pruebas finales y el uso de herramientas tecnológicas para evaluar. En este artículo se aborda el análisis didáctico, desde el diagnostico, de las aplicaciones tecnológicas de uso en la evaluación de la educación hibrida y a distancia , así como los aspectos críticos de la evaluación tradicional, con su énfasis objetivista, el uso de pruebas, la valoración de productos finales y la evaluación supeditada al control administrativo. Del diagnóstico y análisis didáctico, se genera una propuesta de cambios a partir de los supuestos de la evaluación alternativa y autentica, de ejecución y por competencias. Estas metodologías son claves para los cambios en la evaluación del rendimiento, al tomar en cuenta el real desempeño del estudiante para que responda a la realidad de su contexto, de manera relevante, más allá de la evaluación puramente académica. The evaluation of performance is one of the critical processes in education, which merits deepening research and practice, to make its application more pedagogical and less to the use of irrelevant tasks and measurement, whose application to student performance persists both in face-to-face education, as in hybrid and distance learning environments. Several factors affect this problem, such as: institutional appreciation for traditional assessment, difficulty in evaluating

  5. Surface color perception under two illuminants: the second illuminant reduces color constancy

    Science.gov (United States)

    Yang, Joong Nam; Shevell, Steven K.

    2003-01-01

    This study investigates color perception in a scene with two different illuminants. The two illuminants, in opposite corners, simultaneously shine on a (simulated) scene with an opaque dividing wall, which controls how much of the scene is illuminated by each source. In the first experiment, the height of the dividing wall was varied. This changed the amount of each illuminant reaching objects on the opposite side of the wall. Results showed that the degree of color constancy decreased when a region on one side of the wall had cues to both illuminants, suggesting that cues from the second illuminant are detrimental to color constancy. In a later experiment, color constancy was found to improve when the specular highlight cues from the second illuminant were altered to be consistent with the first illuminant. This corroborates the influence of specular highlights in surface color perception, and suggests that the reduced color constancy in the first experiment is due to the inconsistent, though physically correct, cues from the two illuminants.

  6. Color and illuminance level of lighting can modulate willingness to eat bell peppers.

    Science.gov (United States)

    Hasenbeck, Aimee; Cho, Sungeun; Meullenet, Jean-François; Tokar, Tonya; Yang, Famous; Huddleston, Elizabeth A; Seo, Han-Seok

    2014-08-01

    Food products are often encountered under colored lighting, particularly in restaurants and retail stores. However, relatively little attention has been paid to whether the color of ambient lighting can affect consumers' motivation for consumption. This study aimed to determine whether color (Experiment 1) and illuminance level (Experiment 2) of lighting can influence consumers' liking of appearance and their willingness to eat bell peppers. For red, green, and yellow bell peppers, yellow and blue lighting conditions consistently increased participants' liking of appearance the most and the least, respectively. Participants' willingness to consume bell peppers increased the most under yellow lighting and the least under blue lighting. In addition, a dark condition (i.e. low level of lighting illuminance) decreased liking of appearance and willingness to eat the bell peppers compared to a bright condition (i.e. high level of lighting illuminance). Our findings demonstrate that lighting color and illuminance level can influence consumers' hedonic impression and likelihood to consume bell peppers. Furthermore, the influences of color and illuminance level of lighting appear to be dependent on the surface color of bell peppers. © 2013 Society of Chemical Industry.

  7. Illumination compensation in ground based hyperspectral imaging

    Science.gov (United States)

    Wendel, Alexander; Underwood, James

    2017-07-01

    Hyperspectral imaging has emerged as an important tool for analysing vegetation data in agricultural applications. Recently, low altitude and ground based hyperspectral imaging solutions have come to the fore, providing very high resolution data for mapping and studying large areas of crops in detail. However, these platforms introduce a unique set of challenges that need to be overcome to ensure consistent, accurate and timely acquisition of data. One particular problem is dealing with changes in environmental illumination while operating with natural light under cloud cover, which can have considerable effects on spectral shape. In the past this has been commonly achieved by imaging known reference targets at the time of data acquisition, direct measurement of irradiance, or atmospheric modelling. While capturing a reference panel continuously or very frequently allows accurate compensation for illumination changes, this is often not practical with ground based platforms, and impossible in aerial applications. This paper examines the use of an autonomous unmanned ground vehicle (UGV) to gather high resolution hyperspectral imaging data of crops under natural illumination. A process of illumination compensation is performed to extract the inherent reflectance properties of the crops, despite variable illumination. This work adapts a previously developed subspace model approach to reflectance and illumination recovery. Though tested on a ground vehicle in this paper, it is applicable to low altitude unmanned aerial hyperspectral imagery also. The method uses occasional observations of reference panel training data from within the same or other datasets, which enables a practical field protocol that minimises in-field manual labour. This paper tests the new approach, comparing it against traditional methods. Several illumination compensation protocols for high volume ground based data collection are presented based on the results. The findings in this paper are

  8. Studies of the interaction of CS@ZnS:Mn with bovine serum albumin under illumination

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li, E-mail: 2476625723@qq.com [Institute of Agricultural Quality Standards and Testing Technology Research, Hubei Academy of Agricultural Science, Wuhan 430064 (China); Xiao, Ling [School of Resource and Environmental Science, Hubei Biomass-Resource Chemistry and Environmental Biotechnology Key Laboratory, Wuhan University, Wuhan 430072 (China)

    2015-09-15

    Highlights: • The interaction and illumination damages of CS@ZnS:Mn D-dots to BSA were studied. • The quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. • The hydrophobic interaction plays a major role; the binding processes are spontaneous. • The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was observed. • The probable mechanism is mainly a photo-induced free radical procedure. - Abstract: In this study, chitosan coated Mn-doped ZnS quantum dots (CS@ZnS:Mn D-dots) were obtained in aqueous media under ambient pressure. The interaction and illumination damages of CS@ZnS:Mn D-dots with bovine serum albumin (BSA) were studied by means of ultraviolet–visible (UV–vis) and fluorescence (FL) spectra. It was found that the FL of BSA was quenched by CS@ZnS:Mn D-dots. The dominating quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. Hydrophobic interaction plays a major role in the CS@ZnS:Mn–BSA interaction; binding processes are spontaneous. Influencing factors such as illumination time and CS@ZnS:Mn D-dots concentrations were considered. The FL quenching effect of BSA by CS@ZnS:Mn D-dots is enhanced with the increase of illumination time and CS@ZnS:Mn D-dots concentration. The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was also observed. It was proved that, the interaction of CS@ZnS:Mn D-dots with BSA under UV illumination is mainly a result of a photo-induced free radical procedure. CS@ZnS:Mn D-dots may be used as photosensitizers in photodynamic therapy.

  9. Studies of the interaction of CS@ZnS:Mn with bovine serum albumin under illumination

    International Nuclear Information System (INIS)

    Liu, Li; Xiao, Ling

    2015-01-01

    Highlights: • The interaction and illumination damages of CS@ZnS:Mn D-dots to BSA were studied. • The quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. • The hydrophobic interaction plays a major role; the binding processes are spontaneous. • The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was observed. • The probable mechanism is mainly a photo-induced free radical procedure. - Abstract: In this study, chitosan coated Mn-doped ZnS quantum dots (CS@ZnS:Mn D-dots) were obtained in aqueous media under ambient pressure. The interaction and illumination damages of CS@ZnS:Mn D-dots with bovine serum albumin (BSA) were studied by means of ultraviolet–visible (UV–vis) and fluorescence (FL) spectra. It was found that the FL of BSA was quenched by CS@ZnS:Mn D-dots. The dominating quenching mechanism of CS@ZnS:Mn D-dots with BSA belongs to dynamic quenching. Hydrophobic interaction plays a major role in the CS@ZnS:Mn–BSA interaction; binding processes are spontaneous. Influencing factors such as illumination time and CS@ZnS:Mn D-dots concentrations were considered. The FL quenching effect of BSA by CS@ZnS:Mn D-dots is enhanced with the increase of illumination time and CS@ZnS:Mn D-dots concentration. The FL enhancement of CS@ZnS:Mn D-dots by BSA under UV illumination was also observed. It was proved that, the interaction of CS@ZnS:Mn D-dots with BSA under UV illumination is mainly a result of a photo-induced free radical procedure. CS@ZnS:Mn D-dots may be used as photosensitizers in photodynamic therapy

  10. The future is 'ambient'

    Science.gov (United States)

    Lugmayr, Artur

    2006-02-01

    The research field of ambient media starts to spread rapidly and first applications for consumer homes are on the way. Ambient media is the logical continuation of research around media. Media has been evolving from old media (e.g. print media), to integrated presentation in one form (multimedia - or new media), to generating a synthetic world (virtual reality), to the natural environment is the user-interface (ambient media), and will be evolving towards real/synthetic undistinguishable media (bio-media or bio-multimedia). After the IT bubble was bursting, multimedia was lacking a vision of potential future scenarios and applications. Within this research paper the potentials, applications, and market available solutions of mobile ambient multimedia are studied. The different features of ambient mobile multimedia are manifold and include wearable computers, adaptive software, context awareness, ubiquitous computers, middleware, and wireless networks. The paper especially focuses on algorithms and methods that can be utilized to realize modern mobile ambient systems.

  11. Volumetric ambient occlusion for real-time rendering and games.

    Science.gov (United States)

    Szirmay-Kalos, L; Umenhoffer, T; Toth, B; Szecsi, L; Sbert, M

    2010-01-01

    This new algorithm, based on GPUs, can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The first step in deriving this algorithm is to examine how ambient occlusion relates to the physically founded rendering equation. The correspondence stems from a fuzzy membership function that defines what constitutes nearby occlusions. The next step is to develop a method to calculate ambient occlusion in real time without precomputation. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere. The new formula's integrand has low variation and thus can be estimated accurately with a few samples.

  12. Realtime global illumination using compressed pre-computed indirect illumination textures

    DEFF Research Database (Denmark)

    Bahnsen, Chris; Martin dit Neuville, Antoine; Pedersen, Casper

    2012-01-01

    and added to the direct illumination to produce the total illumination. Depending on the type of image produced, the algorithm allows a camera to move, and even objects to be added or modified at runtime to some extent. Finally, we will see that the amount of data to store and process can also be reduced...

  13. Content adaptive illumination for Fourier ptychography.

    Science.gov (United States)

    Bian, Liheng; Suo, Jinli; Situ, Guohai; Zheng, Guoan; Chen, Feng; Dai, Qionghai

    2014-12-01

    Fourier ptychography (FP) is a recently reported technique, for large field-of-view and high-resolution imaging. Specifically, FP captures a set of low-resolution images, under angularly varying illuminations, and stitches them together in the Fourier domain. One of FP's main disadvantages is its long capturing process, due to the requisite large number of incident illumination angles. In this Letter, utilizing the sparsity of natural images in the Fourier domain, we propose a highly efficient method, termed adaptive Fourier ptychography (AFP), which applies content adaptive illumination for FP, to capture the most informative parts of the scene's spatial spectrum. We validate the effectiveness and efficiency of the reported framework, with both simulated and real experiments. Results show that the proposed AFP could shorten the acquisition time of conventional FP, by around 30%-60%.

  14. Dynamic Control Based Photovoltaic Illuminating System

    Directory of Open Access Journals (Sweden)

    Zhang Chengkai

    2016-01-01

    Full Text Available Smart LED illumination system can use the power from whether the photovoltaic cell or the power grid automatically based on the SOC (State Of Charge of the photovoltaic cell. This paper proposes a feedback control of the photovoltaic cells and a dynamic control strategy for the Energy system. The dynamic control strategy is used to determine the switching state of the photovoltaic cell based on the illumination load in the past one hour and the battery capacity. These controls are manifested by experimental prototype that the control scheme is correct and effective.

  15. Illumination engineering design with nonimaging optics

    CERN Document Server

    Koshel, R John

    2012-01-01

    This book brings together experts in the field who present material on a number of important and growing topics including lighting, displays, solar concentrators. The first chapter provides an overview of the field of nonimagin and illumination optics. Included in this chapter are terminology, units, definitions, and descriptions of the optical components used in illumination systems. The next two chapters provide material within the theoretical domain, including etendue, etendue squeezing, and the skew invariant. The remaining chapters focus on growing applications. This entire field of

  16. Illumination Tolerance for Visual Navigation with the Holistic Min-Warping Method

    Directory of Open Access Journals (Sweden)

    Ralf Möller

    2014-02-01

    Full Text Available Holistic visual navigation methods are an emerging alternative to the ubiquitous feature-based methods. Holistic methods match entire images pixel-wise instead of extracting and comparing local feature descriptors. In this paper we investigate which pixel-wise distance measures are most suitable for the holistic min-warping method with respect to illumination invariance. Two novel approaches are presented: tunable distance measures—weighted combinations of illumination-invariant and illumination-sensitive terms—and two novel forms of “sequential” correlation which are only invariant against intensity shifts but not against multiplicative changes. Navigation experiments on indoor image databases collected at the same locations but under different conditions of illumination demonstrate that tunable distance measures perform optimally by mixing their two portions instead of using the illumination-invariant term alone. Sequential correlation performs best among all tested methods, and as well but much faster in an approximated form. Mixing with an additional illumination-sensitive term is not necessary for sequential correlation. We show that min-warping with approximated sequential correlation can successfully be applied to visual navigation of cleaning robots.

  17. Licenciamento ambiental e sustentabilidade

    Directory of Open Access Journals (Sweden)

    Marcelo Macedo Valinhas

    2011-12-01

    Full Text Available A sustentabilidade está apoiada principalmente nas dimensões econômica, ambiental e social. No entanto, sem a dimensão política ela não se constrói. Um dos principais instrumentos de comando e controle da política nacional de meio ambiente, o licenciamento ambiental é um processo contínuo de gestão ambiental pública e privada. Analisou-se o processo de licenciamento ambiental como acoplamento estrutural entre os sistemas social, econômico e ambiental. Apesar da constatação de críticas aos mecanismos de comando e controle dos últimos anos, foi verificado que o Estado do Rio de Janeiro tem buscado integrar a política ambiental do Estado à gestão ambiental privada e que esta integração busca atender às demandas dos sistemas sociais e econômicos para as questões ambientais. Em linhas gerais, este caminho segue as estratégias e ações propostas na Agenda 21 brasileira.

  18. Algorithms in ambient intelligence

    NARCIS (Netherlands)

    Aarts, E.H.L.; Korst, J.H.M.; Verhaegh, W.F.J.; Weber, W.; Rabaey, J.M.; Aarts, E.

    2005-01-01

    We briefly review the concept of ambient intelligence and discuss its relation with the domain of intelligent algorithms. By means of four examples of ambient intelligent systems, we argue that new computing methods and quantification measures are needed to bridge the gap between the class of

  19. Persuasion in Ambient Intelligence

    NARCIS (Netherlands)

    Kaptein, M.C.; Markopoulos, P.; Ruyter, de B.E.R.; Aarts, E.H.L.

    2010-01-01

    Although the field of persuasive technologies has lately attracted a lot of attention, only recently the notion of ambient persuasive technologies was introduced. Ambient persuasive technologies can be integrated into every aspect of life, and as such have greater persuasive power than the

  20. Gestión ambiental como alternativa para la participación comunitaria en el Consejo Popular Altamira Environmental management as an alternative for the community participation in Altamira People's Council

    Directory of Open Access Journals (Sweden)

    Maria Caridad Menéndez Pérez

    2012-07-01

    Full Text Available Se realizó un estudio observacional y descriptivo, basado en 113 habitantes y 44 trabajadores de las empresas más contaminantes del Consejo Popular Altamira de Santiago de Cuba, durante el 2008, para caracterizar los riesgos ambientales más importantes en el área desde los puntos de vista industrial y comunitario e identificar su nivel de conocimientos sobre la percepción al respecto. Se evidenció que estos habitantes desconocían sobre salud ambiental, así como tenían baja percepción de riesgo e insatisfacciones por servicios relacionados con la seguridad ambiental; asimismo, se confirmó que el bajo nivel de conocimientos que poseían los trabajadores de las empresas sobre el daño ambiental provocado, los factores de riesgo a que se exponían y la baja cobertura de medios protectores, las convertían en ambientes inseguros. El desconocimiento de la población, los trabajadores, directivos y cuadros de las empresas sobre el tema obligó a diseñar estrategias de capacitación e intervención comunitaria en función del mejoramiento del medio y la calidad de vida de los pobladores.A descriptive, observational study was carried out, based on 113 people and 44 workers from the most polluting enterprises in Altamira People's Council of Santiago de Cuba during 2008, to characterize the major environmental risks in this area from the industrial and community points of view and to identify their knowledge of the perception in this respect. It was evidenced that these people were unaware of environmental health and had low risk perception and dissatisfactions with services related to environmental security. It was also confirmed that the low level of knowledge of environmental damage held by the workers, exposure to risk factors and inadequate protection means converted these enterprises into unsafe environments. Ignorance of population, enterprise workers, managers and cadres on the subject forced to devise strategies of community

  1. Illumination modelling of a mobile device environment for effective use in driving mobile apps

    Science.gov (United States)

    Marhoubi, Asmaa H.; Saravi, Sara; Edirisinghe, Eran A.; Bez, Helmut E.

    2015-05-01

    The present generation of Ambient Light Sensors (ALS) of a mobile handheld device suffer from two practical shortcomings. The ALSs are narrow angle, i.e. they respond effectively only within a narrow angle of operation and there is a latency of operation. As a result mobile applications that operate based on the ALS readings could perform sub-optimally especially when operated in environments with non-uniform illumination. The applications will either adopt with unacceptable levels of latency or/and may demonstrate a discrete nature of operation. In this paper we propose a framework to predict the ambient illumination of an environment in which a mobile device is present. The predictions are based on an illumination model that is developed based on a small number of readings taken during an application calibration stage. We use a machine learning based approach in developing the models. Five different regression models were developed, implemented and compared based on Polynomial, Gaussian, Sum of Sine, Fourier and Smoothing Spline functions. Approaches to remove noisy data, missing values and outliers were used prior to the modelling stage to remove their negative effects on modelling. The prediction accuracy for all models were found to be above 0.99 when measured using R-Squared test with the best performance being from Smoothing Spline. In this paper we will discuss mathematical complexity of each model and investigate how to make compromises in finding the best model.

  2. Public illumination manual; Manual de iluminacao publica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    This work aims to guide in the correct choice and usage of the adequate public illumination equipment. It also aims to help the public authorities in terms of the best economical and technical choice, as well as the adequate maintenance of the equipment in order to obtain the most efficiency and safety with minimum costs 22 figs., 11 tabs.

  3. Measurement of illumination exposure in postpartum women

    Directory of Open Access Journals (Sweden)

    Stein Martin T

    2003-05-01

    Full Text Available Abstract Background Low levels of light exposure at critical times are thought to cause seasonal affective disorder. Investigators, in studies demonstrating the usefulness of bright light therapy, also have implicated light's role in non-seasonal depression. The precise cause of postpartum depression has not been delineated, but it seemed possible that new mothers would spend reduced time in daylight. The goal of this study was to examine the levels of illumination experienced by postpartum mothers and to discover any relationship between light exposure and mood levels experienced during the postpartum period. Methods Fifteen postpartum women, who did not have any baseline indication of depression, wore a wrist device (Actillume for 72 hours to measure their exposure to light. At the end of the recording period, they completed a self-reported measure of mood. The mean light exposure of these postpartum women (expressed as the 24-hour average logarithm of illumination in lux was compared with that of a representative sample of women of comparable age, residence, and seasonal months of recording. Mood levels were then rank-ordered and tested for correlation with light exposure levels. Results There was no significant difference between the amount of light [log10lux] experienced by postpartum (1.01 SD 0.236 and control women (1.06 SD 0.285. Mood was not correlated with illumination in the postpartum sample. Conclusions Postpartum women in San Diego did not receive reduced light, nor was low mood related to low illumination.

  4. Lighting design for globally illuminated volume rendering.

    Science.gov (United States)

    Zhang, Yubo; Ma, Kwan-Liu

    2013-12-01

    With the evolution of graphics hardware, high quality global illumination becomes available for real-time volume rendering. Compared to local illumination, global illumination can produce realistic shading effects which are closer to real world scenes, and has proven useful for enhancing volume data visualization to enable better depth and shape perception. However, setting up optimal lighting could be a nontrivial task for average users. There were lighting design works for volume visualization but they did not consider global light transportation. In this paper, we present a lighting design method for volume visualization employing global illumination. The resulting system takes into account view and transfer-function dependent content of the volume data to automatically generate an optimized three-point lighting environment. Our method fully exploits the back light which is not used by previous volume visualization systems. By also including global shadow and multiple scattering, our lighting system can effectively enhance the depth and shape perception of volumetric features of interest. In addition, we propose an automatic tone mapping operator which recovers visual details from overexposed areas while maintaining sufficient contrast in the dark areas. We show that our method is effective for visualizing volume datasets with complex structures. The structural information is more clearly and correctly presented under the automatically generated light sources.

  5. Diffuse-Illumination Systems for Growing Plants

    Science.gov (United States)

    May, George; Ryan, Robert

    2010-01-01

    Agriculture in both terrestrial and space-controlled environments relies heavily on artificial illumination for efficient photosynthesis. Plant-growth illumination systems require high photon flux in the spectral range corresponding with plant photosynthetic active radiation (PAR) (400 700 nm), high spatial uniformity to promote uniform growth, and high energy efficiency to minimize electricity usage. The proposed plant-growth system takes advantage of the highly diffuse reflective surfaces on the interior of a sphere, hemisphere, or other nearly enclosed structure that is coated with highly reflective materials. This type of surface and structure uniformly mixes discrete light sources to produce highly uniform illumination. Multiple reflections from within the domelike structures are exploited to obtain diffuse illumination, which promotes the efficient reuse of photons that have not yet been absorbed by plants. The highly reflective surfaces encourage only the plant tissue (placed inside the sphere or enclosure) to absorb the light. Discrete light sources, such as light emitting diodes (LEDs), are typically used because of their high efficiency, wavelength selection, and electronically dimmable properties. The light sources are arranged to minimize shadowing and to improve uniformity. Different wavelengths of LEDs (typically blue, green, and red) are used for photosynthesis. Wavelengths outside the PAR range can be added for plant diagnostics or for growth regulation

  6. Illuminating Everyday Performances of Privilege and Oppression

    Science.gov (United States)

    Heuman, Amy N.

    2018-01-01

    Courses: Intercultural Communication, Interracial Communication, Gender and Communication, Introduction to Communication Course (within a unit on culture), and any courses encouraging critical analyses of power. Objectives: This activity will: illuminate the ways in which everyday performances of privilege and resulting oppressions connect with…

  7. An illumination system for endoscopic applications

    DEFF Research Database (Denmark)

    2013-01-01

    The present disclosure relates to an illumination system for endoscopic applications comprising at least one substantially monochromatic light source having a predefined central wavelength between 400 and 500 nm or between 500 and 550 nm, an optical transmission path adapted to guide light emanat...... for photodynamic diagnosis and/or therapy of bladder cancer is further disclosed herein....

  8. Public illumination manual; Manual de iluminacao publica

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    This work aims to guide in the correct choice and usage of the adequate public illumination equipment. It also aims to help the public authorities in terms of the best economical and technical choice, as well as the adequate maintenance of the equipment in order to obtain the most efficiency and safety with minimum costs 22 figs., 11 tabs.

  9. Interactive indirect illumination using adaptive multiresolution splatting.

    Science.gov (United States)

    Nichols, Greg; Wyman, Chris

    2010-01-01

    Global illumination provides a visual richness not achievable with the direct illumination models used by most interactive applications. To generate global effects, numerous approximations attempt to reduce global illumination costs to levels feasible in interactive contexts. One such approximation, reflective shadow maps, samples a shadow map to identify secondary light sources whose contributions are splatted into eye space. This splatting introduces significant overdraw that is usually reduced by artificially shrinking each splat's radius of influence. This paper introduces a new multiresolution approach for interactively splatting indirect illumination. Instead of reducing GPU fill rate by reducing splat size, we reduce fill rate by rendering splats into a multiresolution buffer. This takes advantage of the low-frequency nature of diffuse and glossy indirect lighting, allowing rendering of indirect contributions at low resolution where lighting changes slowly and at high-resolution near discontinuities. Because this multiresolution rendering occurs on a per-splat basis, we can significantly reduce fill rate without arbitrarily clipping splat contributions below a given threshold-those regions simply are rendered at a coarse resolution.

  10. Scene independent real-time indirect illumination

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall; Christensen, Niels Jørgen; Falster, Peter

    2005-01-01

    A novel method for real-time simulation of indirect illumination is presented in this paper. The method, which we call Direct Radiance Mapping (DRM), is based on basal radiance calculations and does not impose any restrictions on scene geometry or dynamics. This makes the method tractable for rea...

  11. Daylight illumination-color-contrast tables for full-form objects naturally illuminated objects

    CERN Document Server

    Nagel, M

    1978-01-01

    Daylight Illumination-Color-Contrast Tables for Full-form Objects is the result of a major computational project concerning the illumination, color, and contrast conditions in naturally illuminated objects. The project from which this two-chapter book is derived is originally conceived in support of the various remote sensing and image processing activities of the Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt, Oberpfaffenhofen, West Germany DFVLR, in particular, those depending on the quantitative photometric and colorimetric evaluation of photographs and other environmental

  12. Reflectance, illumination, and appearance in color constancy.

    Science.gov (United States)

    McCann, John J; Parraman, Carinna; Rizzi, Alessandro

    2014-01-01

    We studied color constancy using a pair of identical 3-D Color Mondrian displays. We viewed one 3-D Mondrian in nearly uniform illumination, and the other in directional, nonuniform illumination. We used the three dimensional structures to modulate the light falling on the painted surfaces. The 3-D structures in the displays were a matching set of wooden blocks. Across Mondrian displays, each corresponding facet had the same paint on its surface. We used only 6 chromatic, and 5 achromatic paints applied to 104 block facets. The 3-D blocks add shadows and multiple reflections not found in flat Mondrians. Both 3-D Mondrians were viewed simultaneously, side-by-side. We used two techniques to measure correlation of appearance with surface reflectance. First, observers made magnitude estimates of changes in the appearances of identical reflectances. Second, an author painted a watercolor of the 3-D Mondrians. The watercolor's reflectances quantified the changes in appearances. While constancy generalizations about illumination and reflectance hold for flat Mondrians, they do not for 3-D Mondrians. A constant paint does not exhibit perfect color constancy, but rather shows significant shifts in lightness, hue and chroma in response to the structure in the nonuniform illumination. Color appearance depends on the spatial information in both the illumination and the reflectances of objects. The spatial information of the quanta catch from the array of retinal receptors generates sensations that have variable correlation with surface reflectance. Models of appearance in humans need to calculate the departures from perfect constancy measured here. This article provides a dataset of measurements of color appearances for computational models of sensation.

  13. Reflectance, illumination, and appearance in color constancy

    Directory of Open Access Journals (Sweden)

    John J. McCann

    2014-01-01

    Full Text Available We studied color constancy using a pair of identical 3-D Color Mondrian displays. We viewed one 3-D Mondrian in nearly uniform illumination, and the other in directional, nonuniform illumination. We used the three dimensional structures to modulate the light falling on the painted surfaces. The 3-D structures in the displays were a matching set of wooden blocks. Across Mondrian displays, each corresponding facet had the same paint on its surface. We used only 6 chromatic, and 5 achromatic paints applied to 104 block facets. The 3-D blocks add shadows and multiple reflections not found in flat Mondrians. Both 3-D Mondrians were viewed simultaneously, side-by-side. We used two techniques to measure correlation of appearance with surface reflectance. First, observers made magnitude estimates of changes in the appearances of identical reflectances. Second, an author painted a watercolor of the 3-D Mondrians. The watercolor’s reflectances quantified the changes in appearances. While constancy generalizations about illumination and reflectance hold for flat Mondrians, they do not for 3-D Mondrians. A constant paint does not exhibit perfect color constancy, but rather shows significant shifts in lightness, hue and chroma in response to the structure in the nonuniform illumination. Color appearance depends on the spatial information in both the illumination and the reflectances of objects. The spatial information of the quanta catch from the array of retinal receptors generates sensations that have variable correlation with surface reflectance. Models of appearance in humans need to calculate the departures from perfect constancy measured here. This article provides a dataset of measurements of color appearances for computational models of sensation.

  14. Light-Emitting Diode-Based Illumination System for In Vitro Photodynamic Therapy

    OpenAIRE

    Defu Chen; Huifen Zheng; Zhiyong Huang; Huiyun Lin; Zhidong Ke; Shusen Xie; Buhong Li

    2012-01-01

    The aim of this study is to develop a light-emitting diode- (LED-) based illumination system that can be used as an alternative light source for in vitro photodynamic therapy (PDT). This illumination system includes a red LED array composed of 70 LEDs centered at 643 nm, an air-cooling unit, and a specific-designed case. The irradiance as a function of the irradiation distance between the LED array and the sample, the homogeneity and stability of irradiation, and the effect of long-time irrad...

  15. Ambient pressure photoemission spectroscopy of metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Baikie, Iain D., E-mail: iain@kptechnology.ltd.uk; Grain, Angela C.; Sutherland, James; Law, Jamie

    2014-12-30

    Highlights: • Ambient pressure photoemission spectroscopy of metals. • Rastered photon energy scan overcomes inelastic scattering. • Relationship between photoemission threshold and contact potential difference. - Abstract: We describe a novel photoemission technique utilizing a traditional Kelvin probe as a detector of electrons/atmospheric ions ejected from metallic surfaces (Au, Ag, Cu, Fe, Ni, Ti, Zn, Al) illuminated by a deep ultra-violet (DUV) source under ambient pressure. To surmount the limitation of electron scattering in air the incident photon energy is rastered rather than applying a variable retarding electric field as is used with UPS. This arrangement can be applied in several operational modes: using the DUV source to determine the photoemission threshold (Φ) with 30–50 meV resolution and also the Kelvin probe, under dark conditions, to measure contact potential difference (CPD) between the Kelvin probe tip and the metallic sample with an accuracy of 1–3 meV. We have studied the relationship between the photoelectric threshold and CPD of metal surfaces cleaned in ambient conditions. Inclusion of a second spectroscopic visible source was used to confirm a semiconducting oxide, possibly Cu{sub 2}O, via surface photovoltage measurements with the KP. This dual detection system can be easily extended to controlled gas conditions, relative humidity control and sample heating/cooling.

  16. Comparison of two structured illumination techniques based on different 3D illumination patterns

    Science.gov (United States)

    Shabani, H.; Patwary, N.; Doblas, A.; Saavedra, G.; Preza, C.

    2017-02-01

    Manipulating the excitation pattern in optical microscopy has led to several super-resolution techniques. Among different patterns, the lateral sinusoidal excitation was used for the first demonstration of structured illumination microscopy (SIM), which provides the fastest SIM acquisition system (based on the number of raw images required) compared to the multi-spot illumination approach. Moreover, 3D patterns that include lateral and axial variations in the illumination have attracted more attention recently as they address resolution enhancement in three dimensions. A threewave (3W) interference technique based on coherent illumination has already been shown to provide super-resolution and optical sectioning in 3D-SIM. In this paper, we investigate a novel tunable technique that creates a 3D pattern from a set of multiple incoherently illuminated parallel slits that act as light sources for a Fresnel biprism. This setup is able to modulate the illumination pattern in the object space both axially and laterally with adjustable modulation frequencies. The 3D forward model for the new system is developed here to consider the effect of the axial modulation due to the 3D patterned illumination. The performance of 3D-SIM based on 3W interference and the tunable system are investigated in simulation and compared based on two different criteria. First, restored images obtained for both 3D-SIM systems using a generalized Wiener filter are compared to determine the effect of the illumination pattern on the reconstruction. Second, the effective frequency response of both systems is studied to determine the axial and lateral resolution enhancement that is obtained in each case.

  17. Acoustic ambient noise recorder

    Digital Repository Service at National Institute of Oceanography (India)

    Saran, A.K.; Navelkar, G.S.; Almeida, A.M.; More, S.R.; Chodankar, P.V.; Murty, C.S.

    with a robust outfit that can withstand high pressures and chemically corrosion resistant materials. Keeping these considerations in view, a CMOS micro-controller-based marine acoustic ambient noise recorder has been developed with a real time clock...

  18. Algorithms in ambient intelligence

    NARCIS (Netherlands)

    Aarts, E.H.L.; Korst, J.H.M.; Verhaegh, W.F.J.; Verhaegh, W.F.J.; Aarts, E.H.L.; Korst, J.H.M.

    2004-01-01

    In this chapter, we discuss the new paradigm for user-centered computing known as ambient intelligence and its relation with methods and techniques from the field of computational intelligence, including problem solving, machine learning, and expert systems.

  19. Illumination normalization of face image based on illuminant direction estimation and improved Retinex.

    Science.gov (United States)

    Yi, Jizheng; Mao, Xia; Chen, Lijiang; Xue, Yuli; Rovetta, Alberto; Caleanu, Catalin-Daniel

    2015-01-01

    Illumination normalization of face image for face recognition and facial expression recognition is one of the most frequent and difficult problems in image processing. In order to obtain a face image with normal illumination, our method firstly divides the input face image into sixteen local regions and calculates the edge level percentage in each of them. Secondly, three local regions, which meet the requirements of lower complexity and larger average gray value, are selected to calculate the final illuminant direction according to the error function between the measured intensity and the calculated intensity, and the constraint function for an infinite light source model. After knowing the final illuminant direction of the input face image, the Retinex algorithm is improved from two aspects: (1) we optimize the surround function; (2) we intercept the values in both ends of histogram of face image, determine the range of gray levels, and stretch the range of gray levels into the dynamic range of display device. Finally, we achieve illumination normalization and get the final face image. Unlike previous illumination normalization approaches, the method proposed in this paper does not require any training step or any knowledge of 3D face and reflective surface model. The experimental results using extended Yale face database B and CMU-PIE show that our method achieves better normalization effect comparing with the existing techniques.

  20. Illumination normalization of face image based on illuminant direction estimation and improved Retinex.

    Directory of Open Access Journals (Sweden)

    Jizheng Yi

    Full Text Available Illumination normalization of face image for face recognition and facial expression recognition is one of the most frequent and difficult problems in image processing. In order to obtain a face image with normal illumination, our method firstly divides the input face image into sixteen local regions and calculates the edge level percentage in each of them. Secondly, three local regions, which meet the requirements of lower complexity and larger average gray value, are selected to calculate the final illuminant direction according to the error function between the measured intensity and the calculated intensity, and the constraint function for an infinite light source model. After knowing the final illuminant direction of the input face image, the Retinex algorithm is improved from two aspects: (1 we optimize the surround function; (2 we intercept the values in both ends of histogram of face image, determine the range of gray levels, and stretch the range of gray levels into the dynamic range of display device. Finally, we achieve illumination normalization and get the final face image. Unlike previous illumination normalization approaches, the method proposed in this paper does not require any training step or any knowledge of 3D face and reflective surface model. The experimental results using extended Yale face database B and CMU-PIE show that our method achieves better normalization effect comparing with the existing techniques.

  1. Widefield and total internal reflection fluorescent structured illumination microscopy with scanning galvo mirrors

    Science.gov (United States)

    Chen, Youhua; Cao, Ruizhi; Liu, Wenjie; Zhu, Dazhao; Zhang, Zhiming; Kuang, Cuifang; Liu, Xu

    2018-04-01

    We present an alternative approach to realize structured illumination microscopy (SIM), which is capable for live cell imaging. The prototype utilizes two sets of scanning galvo mirrors, a polarization converter and a piezo-platform to generate a fast shifted, s-polarization interfered and periodic variable illumination patterns. By changing the angle of the scanning galvanometer, we can change the position of the spots at the pupil plane of the objective lens arbitrarily, making it easy to switch between widefield and total internal reflection fluorescent-SIM mode and adapting the penetration depth in the sample. Also, a twofold resolution improvement is achieved in our experiments. The prototype offers more flexibility of pattern period and illumination orientation changing than previous systems.

  2. Structured illumination microscopy and its new developments

    Directory of Open Access Journals (Sweden)

    Jianling Chen

    2016-05-01

    Full Text Available Optical microscopy allows us to observe the biological structures and processes within living cells. However, the spatial resolution of the optical microscopy is limited to about half of the wavelength by the light diffraction. Structured illumination microscopy (SIM, a type of new emerging super-resolution microscopy, doubles the spatial resolution by illuminating the specimen with a patterned light, and the sample and light source requirements of SIM are not as strict as the other super-resolution microscopy. In addition, SIM is easier to combine with the other imaging techniques to improve their imaging resolution, leading to the developments of diverse types of SIM. SIM has great potential to meet the various requirements of living cells imaging. Here, we review the recent developments of SIM and its combination with other imaging techniques.

  3. Fast linear method of illumination classification

    Science.gov (United States)

    Cooper, Ted J.; Baqai, Farhan A.

    2003-01-01

    We present a simple method for estimating the scene illuminant for images obtained by a Digital Still Camera (DSC). The proposed method utilizes basis vectors obtained from known memory color reflectance to identify the memory color objects in the image. Once the memory color pixels are identified, we use the ratios of the red/green and blue/green to determine the most likely illuminant in the image. The critical part of the method is to estimate the smallest set of basis vectors that closely represent the memory color reflectances. Basis vectors obtained from both Principal Component Analysis (PCA) and Independent Component Analysis (ICA) are used. We will show that only two ICA basis vectors are needed to get an acceptable estimate.

  4. Pulsed laser illumination of photovoltaic cells

    Science.gov (United States)

    Yater, Jane A.; Lowe, Roland A.; Jenkins, Phillip P.; Landis, Geoffrey A.

    1995-01-01

    In future space missions, free electron lasers (FEL) may be used to illuminate photovoltaic receivers to provide remote power. Both the radio-frequency (RF) and induction FEL produce pulsed rather than continuous output. In this work we investigate cell response to pulsed laser light which simulates the RF FEL format. The results indicate that if the pulse repetition is high, cell efficiencies are only slightly reduced compared to constant illumination at the same wavelength. The frequency response of the cells is weak, with both voltage and current outputs essentially dc in nature. Comparison with previous experiments indicates that the RF FEL pulse format yields more efficient photovoltaic conversion than does an induction FEL format.

  5. Direct illumination LED calibration for telescope photometry

    International Nuclear Information System (INIS)

    Barrelet, E.; Juramy, C.

    2008-01-01

    A calibration method for telescope photometry, based on the direct illumination of a telescope with a calibrated light source regrouping multiple LEDs, is proposed. Its purpose is to calibrate the instrument response. The main emphasis of the proposed method is the traceability of the calibration process and a continuous monitoring of the instrument in order to maintain a 0.2% accuracy over a period of years. Its specificity is to map finely the response of the telescope and its camera as a function of all light ray parameters. This feature is essential to implement a computer model of the instrument representing the variation of the overall light collection efficiency of each pixel for various filter configurations. We report on hardware developments done for SNDICE, the first application of this direct illumination calibration system which will be installed in Canada France Hawaii telescope (CFHT) for its leading supernova experiment (SNLS)

  6. Identifying fecal matter contamination in produce fields using multispectral reflectance imaging under ambient solar illumination

    Science.gov (United States)

    Everard, Colm D.; Kim, Moon S.; Lee, Hoonsoo; O'Donnell, Colm P.

    2016-05-01

    An imaging device to detect fecal contamination in fresh produce fields could allow the producer avoid harvesting fecal contaminated produce. E.coli O157:H7 outbreaks have been associated with fecal contaminated leafy greens. In this study, in-field spectral profiles of bovine fecal matter, soil, and spinach leaves are compared. A common aperture imager designed with two identical monochromatic cameras, a beam splitter, and optical filters was used to simultaneously capture two-spectral images of leaves contaminated with both fecal matter and soil. The optical filters where 10 nm full width half maximum bandpass filters, one at 690 nm and the second at 710 nm. These were mounted in front of the object lenses. New images were created using the ratio of these two spectral images on a pixel by pixel basis. Image analysis results showed that the fecal matter contamination could be distinguished from soil and leaf on the ratio images. The use of this technology has potential to allow detection of fecal contamination in produce fields which can be a source of foodbourne illnesses. It has the added benefit of mitigating cross-contamination during harvesting and processing.

  7. Identifying fecal matter contamination in produce fields using multispectral reflectance imaging under ambient solar illumination

    Science.gov (United States)

    An imaging device to detect fecal contamination in fresh produce fields could allow the producer to avoid harvesting fecal-contaminated produce. E.coli O157:H7 outbreaks have been associated with fecal-contaminated leafy greens. In this study, in-field spectral profiles of bovine fecal matter, soil,...

  8. Downhole interferometric illumination diagnosis and balancing

    OpenAIRE

    Van der Neut, J.

    2012-01-01

    With seismic interferometry or the virtual source method, controlled sources can be redatumed from the Earth’s surface to generate so-called virtual sources at downhole receiver locations. Generally this is done by crosscorrelation of the recorded down-hole data and stacking over source locations. By studying the retrieved data at zero time lag, downhole illumination conditions that determine the virtual source radi- ation pattern can be analyzed without a velocity model. This can be benefici...

  9. Broadband spectrally dynamic solid state illumination source

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, David B; Asghar, Ali; Gupta, Shalini; Kang, Hun; Pan, Ming [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Strassburg, Martin [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Georgia State University, Department of Physics and Astronomy, Atlanta, GA 30302-4106 (United States); Summers, Chris; Ferguson, Ian T [Georgia Institute of Technology, School of Materials Science and Engineering, Atlanta, GA 30332 (United States)

    2006-06-15

    Solid state lighting has done well recently in niche markets such as signage and displays, however, no available SSL technologies incorporate all the necessary attributes for general illumination. Development of a novel solid state general illumination source is discussed here. Two LEDs emitting at two distinct wavelengths can be monolithically grown and used to excite two or more phosphors with varied excitation spectra. The combined phosphorescence spectrum can then be controlled by adjusting the relative intensities of the two LED emissions. Preliminary phosphor analysis shows such a scheme to be viable for use in a spectrally dynamic broadband general illumination source. A tunnel junction is envisioned as a means of current spreading in a buried layer for three terminal operation. However, tunnel junction properties in GaN based materials are not well understood, and require further optimization to be practical devices. Preliminary results on GaN tunnel junctions are presented here as well. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Bessel light sheet structured illumination microscopy

    Science.gov (United States)

    Noshirvani Allahabadi, Golchehr

    Biomedical study researchers using animals to model disease and treatment need fast, deep, noninvasive, and inexpensive multi-channel imaging methods. Traditional fluorescence microscopy meets those criteria to an extent. Specifically, two-photon and confocal microscopy, the two most commonly used methods, are limited in penetration depth, cost, resolution, and field of view. In addition, two-photon microscopy has limited ability in multi-channel imaging. Light sheet microscopy, a fast developing 3D fluorescence imaging method, offers attractive advantages over traditional two-photon and confocal microscopy. Light sheet microscopy is much more applicable for in vivo 3D time-lapsed imaging, owing to its selective illumination of tissue layer, superior speed, low light exposure, high penetration depth, and low levels of photobleaching. However, standard light sheet microscopy using Gaussian beam excitation has two main disadvantages: 1) the field of view (FOV) of light sheet microscopy is limited by the depth of focus of the Gaussian beam. 2) Light-sheet images can be degraded by scattering, which limits the penetration of the excitation beam and blurs emission images in deep tissue layers. While two-sided sheet illumination, which doubles the field of view by illuminating the sample from opposite sides, offers a potential solution, the technique adds complexity and cost to the imaging system. We investigate a new technique to address these limitations: Bessel light sheet microscopy in combination with incoherent nonlinear Structured Illumination Microscopy (SIM). Results demonstrate that, at visible wavelengths, Bessel excitation penetrates up to 250 microns deep in the scattering media with single-side illumination. Bessel light sheet microscope achieves confocal level resolution at a lateral resolution of 0.3 micron and an axial resolution of 1 micron. Incoherent nonlinear SIM further reduces the diffused background in Bessel light sheet images, resulting in

  11. Alternative to chrome in the aluminium surface finishing industry. Low environmental impact surface treatments; Alternativas al cromo en la industria del acabado superficial del aluminio. Tratamientos superficiales de bajo impacto ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Aballe Villero, A.; Bethencourt Nunez, M.; Botana Pedemonte, F. J.; Marco Barcena, M.; Sanchez-Amaya, J. M.

    2001-07-01

    Chromates are one of the most commonly used compounds in anti corrosive protection systems because of its excellent rate efficiency/cost. In the case of aluminium alloys, these compounds are employed as inhibitors as well as in the anticorrosive pretreatments to develop protective films. However, chromates are highly toxic and its use involves a high risk for health and environment. Consequently, in the last years intensive efforts have been achieved in the surface treatment industry to find ecological alternatives to this kind of compounds. In this work, the main alternatives proposed in literature to substitute chromates in the surface treatments of aluminium alloys are reviewed. To begin with, the role of chromates in these systems and their environmental consequences has been briefly reviewed. (Author) 16 refs.

  12. Ambient Dried Aerogels

    Science.gov (United States)

    Jones, Steven M.; Paik, Jong-Ah

    2013-01-01

    A method has been developed for creating aerogel using normal pressure and ambient temperatures. All spacecraft, satellites, and landers require the use of thermal insulation due to the extreme environments encountered in space and on extraterrestrial bodies. Ambient dried aerogels introduce the possibility of using aerogel as thermal insulation in a wide variety of instances where supercritically dried aerogels cannot be used. More specifically, thermoelectric devices can use ambient dried aerogel, where the advantages are in situ production using the cast-in ability of an aerogel. Previously, aerogels required supercritical conditions (high temperature and high pressure) to be dried. Ambient dried aerogels can be dried at room temperature and pressure. This allows many materials, such as plastics and certain metal alloys that cannot survive supercritical conditions, to be directly immersed in liquid aerogel precursor and then encapsulated in the final, dried aerogel. Additionally, the metalized Mylar films that could not survive the previous methods of making aerogels can survive the ambient drying technique, thus making multilayer insulation (MLI) materials possible. This results in lighter insulation material as well. Because this innovation does not require high-temperature or high-pressure drying, ambient dried aerogels are much less expensive to produce. The equipment needed to conduct supercritical drying costs many tens of thousands of dollars, and has associated running expenses for power, pressurized gasses, and maintenance. The ambient drying process also expands the size of the pieces of aerogel that can be made because a high-temperature, high-pressure system typically has internal dimensions of up to 30 cm in diameter and 60 cm in height. In the case of this innovation, the only limitation on the size of the aerogels produced would be in the ability of the solvent in the wet gel to escape from the gel network.

  13. Data based ambient lighting control

    NARCIS (Netherlands)

    2012-01-01

    In controlling an ambient lighting element, a category of data being rendered by a host is identified, ambient lighting data associated with the identified category is retrieved, and the retrieved ambient lighting data is rendered in correspondence with the rendered data. The retrieved ambient

  14. Optimal LED-based illumination control via distributed convex optimization

    NARCIS (Netherlands)

    Aslam, Muhammad; Hermans, R.M.; Pandharipande, A.; Lazar, M.; Boje, Edward; Xia, Xiaohua

    2014-01-01

    Achieving illumination and energy consumption targets is essential in indoor lighting design. The provision of localized illumination to occupants, and the utilization of natural light and energy-efficient light-emitting diode (LED) luminaires can help meet both objectives. Localized illumination

  15. Ambient oxygen promotes tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Ho Joong Sung

    2011-05-01

    Full Text Available Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53-/- mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53-/- mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo.

  16. Adsorbate induced surface alloy formation investigated by near ambient pressure X-ray photoelectron spectroscopy

    DEFF Research Database (Denmark)

    Nierhoff, Anders Ulrik Fregerslev; Conradsen, Christian Nagstrup; McCarthy, David Norman

    2014-01-01

    for engineering of more active or selective catalyst materials. Dynamical surface changes on alloy surfaces due to the adsorption of reactants in high gas pressures are challenging to investigate using standard characterization tools. Here we apply synchrotron illuminated near ambient pressure X-ray photoelectron...

  17. Open LED Illuminator: A Simple and Inexpensive LED Illuminator for Fast Multicolor Particle Tracking in Neurons

    Science.gov (United States)

    Bosse, Jens B.; Tanneti, Nikhila S.; Hogue, Ian B.; Enquist, Lynn W.

    2015-01-01

    Dual-color live cell fluorescence microscopy of fast intracellular trafficking processes, such as axonal transport, requires rapid switching of illumination channels. Typical broad-spectrum sources necessitate the use of mechanical filter switching, which introduces delays between acquisition of different fluorescence channels, impeding the interpretation and quantification of highly dynamic processes. Light Emitting Diodes (LEDs), however, allow modulation of excitation light in microseconds. Here we provide a step-by-step protocol to enable any scientist to build a research-grade LED illuminator for live cell microscopy, even without prior experience with electronics or optics. We quantify and compare components, discuss our design considerations, and demonstrate the performance of our LED illuminator by imaging axonal transport of herpes virus particles with high temporal resolution. PMID:26600461

  18. Open LED Illuminator: A Simple and Inexpensive LED Illuminator for Fast Multicolor Particle Tracking in Neurons.

    Directory of Open Access Journals (Sweden)

    Jens B Bosse

    Full Text Available Dual-color live cell fluorescence microscopy of fast intracellular trafficking processes, such as axonal transport, requires rapid switching of illumination channels. Typical broad-spectrum sources necessitate the use of mechanical filter switching, which introduces delays between acquisition of different fluorescence channels, impeding the interpretation and quantification of highly dynamic processes. Light Emitting Diodes (LEDs, however, allow modulation of excitation light in microseconds. Here we provide a step-by-step protocol to enable any scientist to build a research-grade LED illuminator for live cell microscopy, even without prior experience with electronics or optics. We quantify and compare components, discuss our design considerations, and demonstrate the performance of our LED illuminator by imaging axonal transport of herpes virus particles with high temporal resolution.

  19. Electric Power From Ambient Energy Sources

    Energy Technology Data Exchange (ETDEWEB)

    DeSteese, John G.; Hammerstrom, Donald J.; Schienbein, Lawrence A.

    2000-10-03

    This report summarizes research on opportunities to produce electric power from ambient sources as an alternative to using portable battery packs or hydrocarbon-fueled systems in remote areas. The work was an activity in the Advanced Concepts Project conducted by Pacific Northwest National Laboratory (PNNL) for the Office of Research and Development in the U.S. Department of Energy Office of Nonproliferation and National Security.

  20. Ultra Deep Wave Equation Imaging and Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Alexander M. Popovici; Sergey Fomel; Paul Sava; Sean Crawley; Yining Li; Cristian Lupascu

    2006-09-30

    In this project we developed and tested a novel technology, designed to enhance seismic resolution and imaging of ultra-deep complex geologic structures by using state-of-the-art wave-equation depth migration and wave-equation velocity model building technology for deeper data penetration and recovery, steeper dip and ultra-deep structure imaging, accurate velocity estimation for imaging and pore pressure prediction and accurate illumination and amplitude processing for extending the AVO prediction window. Ultra-deep wave-equation imaging provides greater resolution and accuracy under complex geologic structures where energy multipathing occurs, than what can be accomplished today with standard imaging technology. The objective of the research effort was to examine the feasibility of imaging ultra-deep structures onshore and offshore, by using (1) wave-equation migration, (2) angle-gathers velocity model building, and (3) wave-equation illumination and amplitude compensation. The effort consisted of answering critical technical questions that determine the feasibility of the proposed methodology, testing the theory on synthetic data, and finally applying the technology for imaging ultra-deep real data. Some of the questions answered by this research addressed: (1) the handling of true amplitudes in the downward continuation and imaging algorithm and the preservation of the amplitude with offset or amplitude with angle information required for AVO studies, (2) the effect of several imaging conditions on amplitudes, (3) non-elastic attenuation and approaches for recovering the amplitude and frequency, (4) the effect of aperture and illumination on imaging steep dips and on discriminating the velocities in the ultra-deep structures. All these effects were incorporated in the final imaging step of a real data set acquired specifically to address ultra-deep imaging issues, with large offsets (12,500 m) and long recording time (20 s).

  1. Ambient ionization mass spectrometry

    International Nuclear Information System (INIS)

    Lebedev, A T

    2015-01-01

    Ambient ionization mass spectrometry emerged as a new scientific discipline only about ten years ago. A considerable body of information has been reported since that time. Keeping the sensitivity, performance and informativity of classical mass spectrometry methods, the new approach made it possible to eliminate laborious sample preparation procedures and triggered the development of miniaturized instruments to work directly in the field. The review concerns the theoretical foundations and design of ambient ionization methods. Their advantages and drawbacks, as well as prospects for application in chemistry, biology, medicine, environmetal analysis, etc., are discussed. The bibliography includes 194 references

  2. Hybrid illumination systems for a brigth future

    DEFF Research Database (Denmark)

    Bjarklev, Araceli

    Problem to be adressed: Even with the implementation of the Eco-design directive (2005/32/EC) it is projected that the 20% energy reduction goal will not be reached in 2020. as a matter of fact, the electricity consumption in the illumination sector will not be changed from the levels of cosnsump...... of an interdisciplinary group, we aim to make a prototype of a test system. for this we will merge Solid State and Fiber optic technologies. The overall project will be assessed under  the viewpoints of environmental, socio-economic and esthetical parameters...

  3. Light engine for an illumination device

    DEFF Research Database (Denmark)

    2015-01-01

    Disclosed herein are embodiments of a light engine for an illumination device, the light engine defining an output gate and being configured to output light from said output gate; wherein the light engine comprises: one or more light sources defining a light-emitting area; a concave reflector con...... configured to receive light from the light-emitting area and to direct light from respective portions of the light-emitting area to form a converging beam that converges towards a beam spot at the output gate....

  4. Nonimaging reflectors for efficient uniform illumination.

    Science.gov (United States)

    Gordon, J M; Kashin, P; Rabl, A

    1992-10-01

    Nonimaging reflectors that are an extension of the design principle that was developed for compound parabolic concentrator type devices are proposed for illumination applications. The optical designs presented offer maximal lighting efficiency while they retain sharp angular control of the radiation and highly uniform flux densities on distant target planes. Our results are presented for symmetrical configurations in two dimensions (troughlike reflectors) for flat and for tubular sources. For fields of view of practical interest (half-angle in the 30-60 degrees range), these devices can achieve minimum-tomaximum intensity ratios of 0.7, while they remain compact and incur low reflective losses.

  5. How to make illuminating type poster

    International Nuclear Information System (INIS)

    Kim, Yong Sun; Kang, Duk Sik

    1986-01-01

    Illuminating type poster looks very impressive and one may feel as if it were on the view box in his reading room. Some difficulties and nuisances really exist in making them and a few of demerits can also be encountered that of contrast enhancement and of rough graininess. Contact print renders the best quality, though, Kodak Technical-Pan film with HC-100 (Dil. F) developer, llford XP 1-400 with Kodak C-41 color developer and Kodak Plus-X with Microdiol-X developer combinations also work in minimizing the deterioration of resolution and grains which can almost always occur in enlargement prints.

  6. Freeform lens design for LED collimating illumination.

    Science.gov (United States)

    Chen, Jin-Jia; Wang, Te-Yuan; Huang, Kuang-Lung; Liu, Te-Shu; Tsai, Ming-Da; Lin, Chin-Tang

    2012-05-07

    We present a simple freeform lens design method for an application to LED collimating illumination. The method is derived from a basic geometric-optics analysis and construction approach. By using this method, a highly collimating lens with LED chip size of 1.0 mm × 1.0 mm and optical simulation efficiency of 86.5% under a view angle of ± 5 deg is constructed. To verify the practical performance of the lens, a prototype of the collimator lens is also made, and an optical efficiency of 90.3% with a beam angle of 4.75 deg is measured.

  7. Perceived color shift of ceramics according to the change of illuminating light with spectroradiometer

    Science.gov (United States)

    Cha, Hyun-Suk; Yu, Bin

    2013-01-01

    PURPOSE Perceived color of ceramics changes by the spectral power distribution of ambient light. This study aimed to quantify the amount of shifts in color and color coordinates of clinically simulated seven all-ceramics due to the switch of three ambient light sources using a human vision simulating spectroradiometer. MATERIALS AND METHODS CIE color coordinates, such as L*, a* and b*,of ceramic specimens were measured under three light sources, which simulate the CIE standard illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp). Shifts in color and color coordinate by the switch of lights were determined. Influence of the switched light (D65 to A, or D65 to F9), shade of veneer ceramics (A2 or A3), and brand of ceramics on the shifts was analyzed by a three-way ANOVA. RESULTS Shifts in color and color coordinates were influenced by three factors (P 5.5). When switched to A, CIE a* increased (Δa*: 5.6 to 7.6), however, CIE b* increased (Δb*: 4.9 to 7.8) when switched to F9. CONCLUSION Clinically simulated ceramics demonstrated clinically unacceptable color shifts according to the switches in ambient lights based on spectroradiometric readings. Therefore, shade matching and compatibility evaluation should be performed considering ambient lighting conditions and should be done under most relevant lighting condition. PMID:24049567

  8. Development of flying spot illumination system for stage lighting

    Science.gov (United States)

    Asakawa, Hisashi; Ishii, Katsunori; Koshiro, Hikari; Baba, Junko; Wakaki, Moriaki

    2014-02-01

    The system to control the area of illumination is important for the luminaires used for stages and TV studios. Presently the methods to change the distance between a lamp and lenses, or to use a zooming projection of the aperture illuminated by the lamp are used to control the area. However, these methods require many optical components or mechanical components. Moreover, the energy of the light source is partially consumed by the absorption of the shutter on adjusting the illumination area. On the other hand, the control of the illuminance over the illuminated area is not possible by the methods. In this study, we developed the lighting system which enables to control both the illuminated area and the illuminance distribution within the area by scanning the beam from a LED array light source. The area of illumination was expanded along one dimension by scanning the LED beam using a rotating polygon mirror. The selection of the illuminated width and the control of the illuminance distribution were achieved by synchronizing the pulse width modulation (PWM) control of the LED with the rotation of the mirror using a time sharing control. As a result, various illuminance distributions can be realized at real time by using software control for the luminaire. The developed system has the merits of compact and high efficiency.

  9. Illumination estimation via thin-plate spline interpolation.

    Science.gov (United States)

    Shi, Lilong; Xiong, Weihua; Funt, Brian

    2011-05-01

    Thin-plate spline interpolation is used to interpolate the chromaticity of the color of the incident scene illumination across a training set of images. Given the image of a scene under unknown illumination, the chromaticity of the scene illumination can be found from the interpolated function. The resulting illumination-estimation method can be used to provide color constancy under changing illumination conditions and automatic white balancing for digital cameras. A thin-plate spline interpolates over a nonuniformly sampled input space, which in this case is a training set of image thumbnails and associated illumination chromaticities. To reduce the size of the training set, incremental k medians are applied. Tests on real images demonstrate that the thin-plate spline method can estimate the color of the incident illumination quite accurately, and the proposed training set pruning significantly decreases the computation.

  10. Active illumination and appearance model for face alignment

    DEFF Research Database (Denmark)

    Kahraman, Fatih; Gokmen, M.; Darkner, Sune

    2010-01-01

    Illumination conditions have an explicit effect on the performance of face recognition systems. In particular, varying the illumination upon the face imposes such, complex effects that the identification often fails to provide a stable performance level. In this paper, we propose an approach......, integrating face identity and illumination models in order to reach acceptable and stable face recognition rates. For this purpose, Active Appearance Model (A AM) and illumination model of faces are combined in order to obtain an illumination invariant face localization. The proposed method is an integrated......, is sufficient. There is no need to build complex models for illumination. As a result, this paper has presented a simple and efficient method for face modeling and face alignment in order to increase the performance of face localization by means of the proposed illumination invariant AIA method for face...

  11. Effects of illuminants and illumination time on lettuce growth, yield and nutritional quality in a controlled environment

    Science.gov (United States)

    Shen, Y. Z.; Guo, S. S.; Ai, W. D.; Tang, Y. K.

    2014-07-01

    Effects of illuminants and illumination time on the growth of lettuce were researched. Red-blue light-emitting diodes (LEDs, 90% red light +10% blue light) and white light fluorescent (WF) lamps were compared as the illuminants for plant cultivation. Under each type of illuminant, lettuce was grown at 4 illumination times: 12 h, 16 h, 20 h and 24 h, with the same light intensity of 600 μmolm-2s-1. The leaf net photosynthetic rate (Pn) under the two illuminants was comparable but the shape of lettuce was obviously affected by the illuminant. The WF lamps produced more compact plant, while red-blue LED resulted in less but longer leaves. However, the total leaf area was not significantly affected by the illuminant. The red-blue LED produced nearly same aboveground biomass with far less energy consumption relative to WF lamps. The underground biomass was lowered under red-blue LED in comparison with WF lamps. Red-blue LED could improve the nutritional quality of lettuce by increasing the concentration of soluble sugar and vitamin C (VC) and reducing the concentration of nitrate. Under each type of illuminant, longer illumination time resulted in higher Pn, more leaves and larger leaf area. The total chlorophyll concentration increased while the concentration ratio of chlorophyll a/b decreased with the extension of illumination time. Illumination time had highly significant positive correlation with biomass. Moreover, when total daily light input was kept the same, longer illumination time increased the biomass significantly as well. In addition, longer illumination time increased the concentration of crude fiber, soluble sugar and VC and reduced the concentration of nitrate. In summary, red-blue LEDs and 24 h illumination time were demonstrated to be more suitable for lettuce cultivation in the controlled environment.

  12. Gaussian Hypothesis Testing and Quantum Illumination.

    Science.gov (United States)

    Wilde, Mark M; Tomamichel, Marco; Lloyd, Seth; Berta, Mario

    2017-09-22

    Quantum hypothesis testing is one of the most basic tasks in quantum information theory and has fundamental links with quantum communication and estimation theory. In this paper, we establish a formula that characterizes the decay rate of the minimal type-II error probability in a quantum hypothesis test of two Gaussian states given a fixed constraint on the type-I error probability. This formula is a direct function of the mean vectors and covariance matrices of the quantum Gaussian states in question. We give an application to quantum illumination, which is the task of determining whether there is a low-reflectivity object embedded in a target region with a bright thermal-noise bath. For the asymmetric-error setting, we find that a quantum illumination transmitter can achieve an error probability exponent stronger than a coherent-state transmitter of the same mean photon number, and furthermore, that it requires far fewer trials to do so. This occurs when the background thermal noise is either low or bright, which means that a quantum advantage is even easier to witness than in the symmetric-error setting because it occurs for a larger range of parameters. Going forward from here, we expect our formula to have applications in settings well beyond those considered in this paper, especially to quantum communication tasks involving quantum Gaussian channels.

  13. Multiscale Pigment Analysis of Medieval Illuminated Manuscripts

    Science.gov (United States)

    Sestak, Erica; Manukyan, Khachatur; Wiescher, Michael; Gura, David

    2017-09-01

    Three medieval illuminated manuscripts (codd. Lat. b. 1; Lat. b. 2; Lat. e. 4), housed at the University of Notre Dame's Hesburgh Library, vary in style, pigments, scribes, and regions, despite all three being Psalters used in the Late Middle Ages. XRF and Raman spectroscopy, which provided the elemental and molecular composition of the pigments, respectively, were used to analyze the pigments' compositions in an attempt to narrow further the manuscripts' possible origins. This experimental investigation emphasizes the importance of understanding the history of the manuscript through their pigments. Codd. Lat. b. 1 and Lat. b. 2 are Latinate German Psalters from the fifteenth century likely used in Katharinenkloster in Nuremberg. While there are visible differences in style within each Psalter, the variations in some of the pigment compositions, such as the inconstant presence of zinc, suggest different admixtures. Cod. Lat. e. 4 is a Latinate English Psalter from the fourteenth century, and it was written by two scribes and illuminated by two distinct painters. It is currently being tested to determine whether there are any correlations between the scribes and painters. These physical analyses will clarify the origins and provenances of the manuscripts.

  14. Illuminating Chaucer through Poetry, Manuscript Illuminations, and a Critical Rap Album

    Science.gov (United States)

    Lynch, Tom Liam

    2007-01-01

    Drawing connections between Chaucer, Eminem, and social issues, New York City high school teacher Tom Liam Lynch helped students become familiar with "The Canterbury Tales." Students wrote poems of rhymed couplets about today's social and political issues, created illuminated manuscripts, and recorded a rap CD. A book and album were…

  15. Mono- and dichromatic LED illumination leads to enhanced growth and energy conversion for high-efficiency cultivation of microalgae for application in space.

    Science.gov (United States)

    Wagner, Ines; Steinweg, Christian; Posten, Clemens

    2016-08-01

    Illumination with red and blue photons is known to be efficient for cultivation of higher plants. For microalgae cultivation, illumination with specific wavelengths rather than full spectrum illumination can be an alternative where there is a lack of knowledge about achievable biomass yields. This study deals with the usage of color LED illumination to cultivate microalgae integrated into closed life support systems for outer space. The goal is to quantify biomass yields using color illumination (red, blue, green and mixtures) compared to white light. Chlamydomonas reinhardtii was cultivated in plate reactors with color compared to white illumination regarding PCE, specific pigment concentration and cell size. Highest PCE values were achieved under low PFDs with a red/blue illumination (680 nm/447 nm) at a 90 to 10% molar ratio. At higher PFDs saturation effects can be observed resulting from light absorption characteristics and the linear part of PI curve. Cell size and aggregation are also influenced by the applied light color. Red/blue color illumination is a promising option applicable for microalgae-based modules of life support systems under low to saturating light intensities and double-sided illumination. Results of higher PCE with addition of blue photons to red light indicate an influence of sensory pigments. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Measurement of Ambient Air Motion of D. I. Gasoline Spray by LIF-PIV

    Science.gov (United States)

    Yamakawa, Masahisa; Isshiki, Seiji; Yoshizaki, Takuo; Nishida, Keiya

    Ambient air velocity distributions in and around a D. I. gasoline spray were measured using a combination of LIF and PIV techniques. A rhodamine and water solution was injected into ambient air to disperse the fine fluorescent liquid particles used as tracers. A fuel spray was injected into the fluorescent tracer cloud and was illuminated by an Nd: YAG laser light sheet (532nm). The scattered light from the spray droplets and tracers was cut off by a high-pass filter (>560nm). As the fluorescence (>600nm) was transmitted through the high-pass filter, the tracer images were captured using a CCD camera and the ambient air velocity distribution could be obtained by PIV based on the images. This technique was applied to a D. I. gasoline spray. The ambient air flowed up around the spray and entered into the tail of the spray. Furthermore, the relative velocity between the spray and ambient air was investigated.

  17. Alternative security

    International Nuclear Information System (INIS)

    Weston, B.H.

    1990-01-01

    This book contains the following chapters: The Military and Alternative Security: New Missions for Stable Conventional Security; Technology and Alternative Security: A Cherished Myth Expires; Law and Alternative Security: Toward a Just World Peace; Politics and Alternative Security: Toward a More Democratic, Therefore More Peaceful, World; Economics and Alternative Security: Toward a Peacekeeping International Economy; Psychology and Alternative Security: Needs, Perceptions, and Misperceptions; Religion and Alternative Security: A Prophetic Vision; and Toward Post-Nuclear Global Security: An Overview

  18. Indicadores de salud ambiental

    Directory of Open Access Journals (Sweden)

    Manuel Posada de la Paz

    2004-12-01

    Full Text Available Esta ponencia presenta una visión general del proyecto de Indicadores de Salud Ambiental, coordinado por la OMS a nivel internacional y liderado por el Centro de Investigación sobre el Síndrome del Aceite Tóxico y Enfermedades Raras (CISATER en España. En ella se describen los objetivos del proyecto, las gestiones realizadas y los resultados obtenidos durante la fase de viabilidad de este proyecto. El proyecto consiste en el establecimiento de un sistema de información sobre salud ambiental que permita desarrollar una vigilancia de los factores ambientales determinantes de los estados de salud, realizar comparaciones internacionales, elaborar políticas de acción, así como facilitar la comunicación con la ciudadanía. La OMS desarrolló una metodología para el desarrollo de estos indicadores dentro del marco conceptual de información ambiental DPSEEA (Fuerzas impulsoras, Presión, Estado, Exposición, Efecto, Acción y seleccionó un total de 55 indicadores (que incluyen 168 variables sobre 10 áreas de la salud ambiental. Durante la fase de viabilidad se predijo que podrían obtenerse el 89% de los indicadores. Sin embargo la recolección de los datos supuso muchas dificultades debido a la incompatibilidad de algunas variables en los sistemas de información españoles con las variables definidas por la OMS. A nivel de gestión del proyecto, la mayor dificultad radica en la disparidad de responsabilidades en materia de medio ambiente y salud entre las instituciones españolas. Además de la aportación técnica a la salud ambiental en España, un valor añadido de este proyecto ha sido el establecimiento de líneas de colaboración estrechas con los responsables de los diferentes Ministerios implicados.

  19. Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Office of Air and Radiation's (OAR) Ambient Air Quality Data (Current) contains ambient air pollution data collected by EPA, other federal agencies, as well as...

  20. Carrier illumination measurement of dopant lateral diffusion

    International Nuclear Information System (INIS)

    Budiarto, E.; Segovia, M.; Borden, P.; Felch, S.

    2005-01-01

    This paper describes the application of the carrier illumination technique to non-destructively measure the lateral diffusion of implanted dopants after annealing. Experiments to validate the feasibility of this method employed test structures with a constant line width of 300 nm and varying undoped spaces of 100-5000 nm. The test patterns were implanted with a p-type dopant and annealed in a 3 x 3 matrix. For each implant condition, the measured lateral diffusion was found to increase with annealing temperature, as expected. More interestingly, the lateral diffusion was not observed to relate to the vertical diffusion by a fixed proportionality factor, as is usually assumed. The ratio of lateral to vertical diffusion varies with annealing temperature, with a trend that depends on the implant condition

  1. Uniform LED illuminator for miniature displays

    Science.gov (United States)

    Medvedev, Vladimir; Pelka, David G.; Parkyn, William A.

    1998-10-01

    The Total Internally Reflecting (TIR) lens is a faceted structure composed of prismatic elements that collect a source's light over a much larger angular range than a conventional Fresnel lens. It has been successfully applied to the efficient collimation of light from incandescent and fluorescent lamps, and from light-emitting diodes (LEDs). A novel LED-powered collimating backlight is presented here, for uniformly illuminating 0.25'-diagonal miniature liquid- crystal displays, which are a burgeoning market for pagers, cellular phones, digital cameras, camcorders, and virtual- reality displays. The backlight lens consists of a central dual-asphere refracting section and an outer TIR section, properly curved with a curved exit face.

  2. Illuminating magma shearing processes via synchrotron imaging

    Science.gov (United States)

    Lavallée, Yan; Cai, Biao; Coats, Rebecca; Kendrick, Jackie E.; von Aulock, Felix W.; Wallace, Paul A.; Le Gall, Nolwenn; Godinho, Jose; Dobson, Katherine; Atwood, Robert; Holness, Marian; Lee, Peter D.

    2017-04-01

    Our understanding of geomaterial behaviour and processes has long fallen short due to inaccessibility into material as "something" happens. In volcanology, research strategies have increasingly sought to illuminate the subsurface of materials at all scales, from the use of muon tomography to image the inside of volcanoes to the use of seismic tomography to image magmatic bodies in the crust, and most recently, we have added synchrotron-based x-ray tomography to image the inside of material as we test it under controlled conditions. Here, we will explore some of the novel findings made on the evolution of magma during shearing. These will include observations and discussions of magma flow and failure as well as petrological reaction kinetics.

  3. Optimization of laboratory illumination in optical dating

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew; Lindvold, Lars René

    2017-01-01

    As part of the development of new laboratory lighting, we present a methodological approach applicable to the characterization of any light source intended for illumination in optical dating laboratories. We derive optical absorption cross-sections for quartz and feldspar from published data......-emitting diodes (LEDs); this comparison demonstrates the significant advantage of the LED sources over the filtered light sources, because essentially all of the reduction of both OSL and IRSL signals by the LEDs occurs at wavelengths to which the human eye is most sensitive. We conclude that exposure of quartz...... and feldspar extracts from various samples to the light from an LED with emission peak at 594 nm results in a 1% OSL or IRSL signal loss for a 48-h exposure at a power density of ~0.2 mW.cm-2....

  4. Consumo de água pela cultura do lírio, cultivado em substratos alternativos em condições de ambiente protegido Water consumption by the lily culture grown on alternative substrates in protected conditions

    Directory of Open Access Journals (Sweden)

    Fátima Cibele Soares

    2012-06-01

    Full Text Available O presente trabalho teve como objetivo avaliar o consumo de água em oito substratos (casca de arroz carbonizada - CAC, cinza da casca de arroz queimada - CZ, fibra de coco - FC, terra do paraíso - TP, TP+CAC, TP+CZ, FC+CAC e FC+CZ e definir qual desses substratos é melhor para produção comercial de lírio asiático "Orange Pixie��", cultivado em vaso e condições de ambiente protegido. O experimento foi conduzido em casa de vegetação, no Departamento de Fitotecnia da UFSM, Santa Maria, RS. O delineamento experimental foi inteiramente casualizado, utilizando-se 12 repetições e três plantas por vaso para determinar a freqüência de irrigação e o consumo de água. Para as avaliações dos parâmetros, estipularam-se limites de no mínimo 60% e no máximo de 80% da capacidade de recipiente, verificado diariamente em balança digital. As determinações realizadas nos substratos foram: densidade do substrato, porosidade total, espaço de aeração e água disponível. Na planta foram determinados os seguintes parâmetros: altura da planta e da inserção da primeira flor, número de folhas e flores, distância entrenó, comprimento médio das folhas e pétalas, largura média das folhas e pétalas, consumo total de água e freqüência de irrigação. Os resultados evidenciaram que o lírio asiático "Orange Pixie®" em vaso se adapta para cultivo em substrato de terra do paraíso e na mistura fibra de coco mais cinza de casca de arroz. Estes substratos apresentaram um consumo médio de água de 121,65 e 106,78mL e freqüência de irrigação de 22 e 21 dias, respectivamente. A melhor combinação não foi a que mais consumiu água, mas a que exigiu maior freqüência de irrigações.This study aimed to evaluate the consumption of water in eight substrates (rice hulls - CAC, rice husk ash burned - CZ, coconut fiber - CF, land of paradise - TP, TP+CAC, TP+CZ , FC+CAC and FC+CZ and define which of these substrates are the best for

  5. Medio ambiente urbano

    OpenAIRE

    Rodríguez-Chaves Mimbrero, Blanca

    2007-01-01

    El estudio  y análisis  de las interacciones  entre  ambiente  y desarrollo y  su inserción  en los procesos  de  planificación del crecimiento  social y económico  de  los  países  de América Latina, reviste especial interés para proponer alternativas de acción que  conduzcan  al  logro  de  una mejor  calidad de  vida.  El impacto  que las conferencias sobre  el  Medio Ambiente Humano Estocolmo (1972),  Cocoyoc  (1974) o de documentos como "Nuestro Futuro Común" o "Nuestra Propia Agenda" ha...

  6. NIF Ambient Vibration Measurements

    International Nuclear Information System (INIS)

    Noble, C.R.; Hoehler, M.S.; S.C. Sommer

    1999-01-01

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B

  7. MEIO AMBIENTE E DESENVOLVIMENTO

    Directory of Open Access Journals (Sweden)

    Suely Salgueiro Chacon

    2009-12-01

    Full Text Available O objetivo deste artigo é resgatar elementos para subsidiar uma reflexão crítica sobre o modelo de desenvolvimento econômico prevalente na sociedade e as relações com o meio ambiente, sob a ameaça que ronda o destino da espécie humana, conforme afirmação de Lovelock (2006, p. 20 sobre o conceito de desenvolvimento sustentável: “uma ideia adorável se a tivéssemos aplicado 200 anos atrás, quando havia um bilhão de pessoas no mundo. Agora é tarde demais. Não há mais espaço para nenhum tipo de desenvolvimento. A humanidade tem que regredir”. Este artigo apresenta a evolução do conceito de desenvolvimento econômico sob a ótica da sustentabilidade, e interliga temas como: o ambientalismo, aglutinador de distintos pensamentos sobre as relações entre a sociedade e a natureza; o movimento ambiental, a fundamentar a disseminação do conceito de desenvolvimento sustentável, e a gestão ambiental, abordada como prática orientada pelo conceito de desenvolvimento sustentável.

  8. Energy efficient LED layout optimization for near-uniform illumination

    Science.gov (United States)

    Ali, Ramy E.; Elgala, Hany

    2016-09-01

    In this paper, we consider the problem of designing energy efficient light emitting diodes (LEDs) layout while satisfying the illumination constraints. Towards this objective, we present a simple approach to the illumination design problem based on the concept of the virtual LED. We formulate a constrained optimization problem for minimizing the power consumption while maintaining a near-uniform illumination throughout the room. By solving the resulting constrained linear program, we obtain the number of required LEDs and the optimal output luminous intensities that achieve the desired illumination constraints.

  9. An Active Illumination and Appearance (AIA) Model for Face Alignment

    DEFF Research Database (Denmark)

    Kahraman, Fatih; Gokmen, Muhittin; Darkner, Sune

    2007-01-01

    Face recognition systems are typically required to work under highly varying illumination conditions. This leads to complex effects imposed on the acquired face image that pertains little to the actual identity. Consequently, illumination normalization is required to reach acceptable recognition...... rates in face recognition systems. In this paper, we propose an approach that integrates the face identity and illumination models under the widely used Active Appearance Model framework as an extension to the texture model in order to obtain illumination-invariant face localization...

  10. Determination of illuminants representing typical white light emitting diodes sources

    DEFF Research Database (Denmark)

    Jost, S.; Ngo, M.; Ferrero, A.

    2017-01-01

    is to develop LED-based illuminants that describe typical white LED products based on their Spectral Power Distributions (SPDs). Some of these new illuminants will be recommended in the update of the CIE publication 15 on colorimetry with the other typical illuminants, and among them, some could be used......Solid-state lighting (SSL) products are already in use by consumers and are rapidly gaining the lighting market. Especially, white Light Emitting Diode (LED) sources are replacing banned incandescent lamps and other lighting technologies in most general lighting applications. The aim of this work...... to complement the CIE standard illuminant A for calibration use in photometry....

  11. High Efficiency, Illumination Quality OLEDs for Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Shiang; James Cella; Kelly Chichak; Anil Duggal; Kevin Janora; Chris Heller; Gautam Parthasarathy; Jeffery Youmans; Joseph Shiang

    2008-03-31

    The goal of the program was to demonstrate a 45 lumen per watt white light device based upon the use of multiple emission colors through the use of solution processing. This performance level is a dramatic extension of the team's previous 15 LPW large area illumination device. The fundamental material system was based upon commercial polymer materials. The team was largely able to achieve these goals, and was able to deliver to DOE a 90 lumen illumination source that had an average performance of 34 LPW a 1000 cd/m{sup 2} with peak performances near 40LPW. The average color temperature is 3200K and the calculated CRI 85. The device operated at a brightness of approximately 1000cd/m{sup 2}. The use of multiple emission colors particularly red and blue, provided additional degrees of design flexibility in achieving white light, but also required the use of a multilayered structure to separate the different recombination zones and prevent interconversion of blue emission to red emission. The use of commercial materials had the advantage that improvements by the chemical manufacturers in charge transport efficiency, operating life and material purity could be rapidly incorporated without the expenditure of additional effort. The program was designed to take maximum advantage of the known characteristics of these material and proceeded in seven steps. (1) Identify the most promising materials, (2) assemble them into multi-layer structures to control excitation and transport within the OLED, (3) identify materials development needs that would optimize performance within multilayer structures, (4) build a prototype that demonstrates the potential entitlement of the novel multilayer OLED architecture (5) integrate all of the developments to find the single best materials set to implement the novel multilayer architecture, (6) further optimize the best materials set, (7) make a large area high illumination quality white OLED. A photo of the final deliverable is shown

  12. Alternative additives; Alternative additiver

    Energy Technology Data Exchange (ETDEWEB)

    2007-08-15

    In this project a number of industrial and agricultural waste products have been characterised and evaluated in terms of alkali-getter performance. The intended use is for biomass-fired power stations aiming at reducing corrosion or slagging related problems. The following products have been obtained, characterised and evaluated: 1) Brewery draff 2) Danish de-gassed manure 3) Paper sludge 4) Moulding sand 5) Spent bleaching earth 6) Anorthosite 7) Sand 8) Clay-sludge. Most of the above alternative additive candidates are deemed unsuitable due to insufficient chemical effect and/or expensive requirements for pre-treatment (such as drying and transportation). 3 products were selected for full-scale testing: de-gassed manure, spent bleaching earth and clay slugde. The full scale tests were undertaken at the biomass-fired power stations in Koege, Slagelse and Ensted. Spent bleaching earth (SBE) and clay sludge were the only tested additive candidates that had a proven ability to react with KCl, to thereby reduce Cl-concentrations in deposits, and reduce the deposit flux to superheater tubes. Their performance was shown to nearly as good as commercial additives. De-gassed manure, however, did not evaluate positively due to inhibiting effects of Ca in the manure. Furthermore, de-gassed manure has a high concentration of heavy metals, which imposes a financial burden with regard to proper disposal of the ash by-products. Clay-sludge is a wet clay slurring, and drying and transportation of this product entails substantial costs. Spent bleaching does not require much pre-treatment and is therefore the most promising alternative additive. On the other hand, bleaching earth contains residual plant oil which means that a range of legislation relating to waste combustion comes into play. Not least a waste combustion fee of 330 DKK/tonne. For all alternative (and commercial) additives disposal costs of the increase ash by-products represents a significant cost. This is

  13. "Enlivening and - Dividing": An Aporia of Illumination

    Directory of Open Access Journals (Sweden)

    Hans Christian Hönes

    2015-08-01

    Full Text Available Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Verdana;} In 1798, Karl August Böttiger paid a nocturnal visit to the Gallery of Antiques in Dresden, illuminating the statues with a torch. At first glance, this seems to be yet another example of a popular practice for visiting galleries c.1800. Illuminating the sculptures by torchlight was a popular means of enlivening the objects, set in motion by the light flickering on their surfaces. The collections were thus meant to become a place where cold, white stone comes to life, and where the beholder becomes part of a revived antiquity.This was precisely what Böttiger intended, too. But to him, the effect of the torchlight appeared to be, as he wrote, “enlivening and – dividing!” The torchlight highlighted not only the beauty of the sculptures but also their modern restorations. Böttiger apparently failed to experience the living presence of the antique celebrated by many of his contemporaries (e.g. Goethe, Moritz.This essay focuses on the consequence of such a perception of sculptures as historically multi-layered objects. Böttiger’s experience resulted in a problematic situation. In trying to view the sculptures as contemporaries, he hoped to become ancient himself. But this operation failed in the moment when the sculptures themselves appeared to be anachronistic, impure palimpsests. In consequence, galleries may not only be the place were art history as chronological Stilgeschichte was born. They may also be the site where this perception changed into the experience of a more chaotic shape of time.

  14. Structured illumination to spatially map chromatin motions.

    Science.gov (United States)

    Bonin, Keith; Smelser, Amanda; Moreno, Naike Salvador; Holzwarth, George; Wang, Kevin; Levy, Preston; Vidi, Pierre-Alexandre

    2018-05-01

    We describe a simple optical method that creates structured illumination of a photoactivatable probe and apply this method to characterize chromatin motions in nuclei of live cells. A laser beam coupled to a diffractive optical element at the back focal plane of an excitation objective generates an array of near diffraction-limited beamlets with FWHM of 340  ±  30  nm, which simultaneously photoactivate a 7  ×  7 matrix pattern of GFP-labeled histones, with spots 1.70  μm apart. From the movements of the photoactivated spots, we map chromatin diffusion coefficients at multiple microdomains of the cell nucleus. The results show correlated motions of nearest chromatin microdomain neighbors, whereas chromatin movements are uncorrelated at the global scale of the nucleus. The method also reveals a DNA damage-dependent decrease in chromatin diffusion. The diffractive optical element instrumentation can be easily and cheaply implemented on commercial inverted fluorescence microscopes to analyze adherent cell culture models. A protocol to measure chromatin motions in nonadherent human hematopoietic stem and progenitor cells is also described. We anticipate that the method will contribute to the identification of the mechanisms regulating chromatin mobility, which influences most genomic processes and may underlie the biogenesis of genomic translocations associated with hematologic malignancies. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  15. Junction depth measurement using carrier illumination

    International Nuclear Information System (INIS)

    Borden, Peter

    2001-01-01

    Carrier Illumination [trade mark] (CI) is a new method recently developed to meet the need for a non-destructive, high throughput junction depth measurement on patterned wafers. A laser beam creates a quasi-static excess carrier profile in the semiconductor underlying the activated junction. The excess carrier profile is fairly constant below the junction, and drops rapidly in the junction, creating a steep index of refraction gradient at the junction edge. Interference with light reflected from this index gradient provides a signal that is analyzed to determine the junction depth. The paper summarizes evaluation of performance in full NMOS and PMOS process flows, on both bare and patterned wafers. The aims have been to validate (1) performance in the presence of underlying layers typically found at the source/drain (S/D) process steps and (2) measurement on patterned wafers. Correlation of CI measurements to SIMS and transistor drive current are shown. The data were obtained from NMOS structures using As S/D and LDD implants. Correlations to SRP, SIMS and sheet resistance are shown for PMOS structures using B 11 LDD implants. Gage capability measurements are also presented

  16. Tachistoscopic illumination and masking of real scenes.

    Science.gov (United States)

    Chichka, David; Philbeck, John W; Gajewski, Daniel A

    2015-03-01

    Tachistoscopic presentation of scenes has been valuable for studying the emerging properties of visual scene representations. The spatial aspects of this work have generally been focused on the conceptual locations (e.g., next to the refrigerator) and directional locations of objects in 2-D arrays and/or images. Less is known about how the perceived egocentric distance of objects develops. Here we describe a novel system for presenting brief glimpses of a real-world environment, followed by a mask. The system includes projectors with mechanical shutters for projecting the fixation and masking images, a set of LED floodlights for illuminating the environment, and computer-controlled electronics to set the timing and initiate the process. Because a real environment is used, most visual distance and depth cues can be manipulated using traditional methods. The system is inexpensive, robust, and its components are readily available in the marketplace. This article describes the system and the timing characteristics of each component. We verified the system's ability to control exposure to time scales as low as a few milliseconds.

  17. Illuminating the chirality of Weyl fermions

    Science.gov (United States)

    Ma, Qiong; Xu, Su-Yang; Chan, Ching-Kit; Zhang, Cheng-Long; Chang, Guoqing; Lin, Hsin; Jia, Shuang; Lee, Patrick; Gedik, Nuh; Jarillo-Herrero, Pablo

    In particle physics, Weyl fermions (WF) are elementary particles that travel at the speed of light and have a definite chirality. In condensed matter, it has been recently realized that WFs can arise as magnetic monopoles in the momentum space of a novel topological metal, the Weyl semimetal (WSM). Their chirality, given by the sign of the monopole charge, is the defining property of a WSM, since it directly serves as the topological number and gives rise to exotic properties such as Fermi arcs and the chiral anomaly. Moreover, the two chiralities, analogous to the two valleys in 2D materials, lead to a new degree of freedom in a 3D crystal, suggesting novel pathways to store and carry information. By shining circularly polarized light on the WSM TaAs, we illuminate the chirality of the WFs and achieve an electrical current that is highly controllable based on the WFs' chirality. Our results open up a wide range of new possibilities for experimentally studying and controlling the WFs and their associated quantum anomalies by optical and electrical means, which suggest the exciting prospect of ``Weyltronics''.

  18. Combining Illumination Normalization Methods for Better Face Recognition

    NARCIS (Netherlands)

    Boom, B.J.; Tao, Q.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.

    2009-01-01

    Face Recognition under uncontrolled illumination conditions is partly an unsolved problem. There are two categories of illumination normalization methods. The first category performs a local preprocessing, where they correct a pixel value based on a local neighborhood in the images. The second

  19. Transfer between Pose and Illumination Training in Face Recognition

    Science.gov (United States)

    Liu, Chang Hong; Bhuiyan, Md. Al-Amin; Ward, James; Sui, Jie

    2009-01-01

    The relationship between pose and illumination learning in face recognition was examined in a yes-no recognition paradigm. The authors assessed whether pose training can transfer to a new illumination or vice versa. Results show that an extensive level of pose training through a face-name association task was able to generalize to a new…

  20. Infrared Illuminated CdZnTe detectors with improved performance

    International Nuclear Information System (INIS)

    Ivanov, V.; Loutchanski, A.; Dorogov, P.; Khinoverov, S.

    2013-06-01

    It was found that IR illumination of a properly chosen wavelength and intensity can significantly improve spectrometric characteristics of CdZnTe quasi-hemispherical detectors [1]. Improving of the spectrometric characteristics is due to improvement of uniformity of charge collection by the detector volume. For operation at room temperature the optimal wavelength of IR illumination is about 940 nm, but for operation at lower temperature of -20 deg. C the optimal wavelengths of IR illumination is about 1050 nm. Infrared illumination can be performed using conventional low-power IR LEDs. Application of SMD LEDs allows produce miniature detection probes with IR illuminated CdZnTe detectors. We have fabricated and tested a variety of detection probes with CdZnTe quasi-hemispherical detectors from the smallest with volumes of 1-5 mm 3 to larger with volumes of 1.5 cm 3 and 4.0 cm 3 . The use of IR illumination significantly improves spectrometric characteristics of the probes operating at room temperature, especially probes with detectors of large volumes. The probe with the detector of 4 cm 3 without IR illumination had energy resolution of 24.2 keV at 662 keV and of 12.5 keV with IR illumination. (authors)

  1. Dioxinas y medio ambiente

    Directory of Open Access Journals (Sweden)

    María Teresa Frejo Moya

    2011-12-01

    Full Text Available Con el término genérico dioxinas se designa al grupo de las dibenzo-p-dioxinas policloradas (PCDD y de los dibenzofuranos policlorados (PCDF, representantes típicos de los compuestos orgánicos persistentes (COPs. Se obtienen como productos secundarios no deseados de diversos procesos industriales en los que se emplea cloro en alguna de sus etapas. Las dioxinas han centrado en la última década una parte importante de la investigación médica en salud ambiental debido a su notable toxicidad, ya que son las sustancias químicas peligrosas más potentes creadas por el hombre, afectando al sistema nervioso e inmunitario, estando implicadas en la aparición de distintos tipos de cáncer y provocando la aparición de alteraciones hormonales, clasificándose actualmente como disruptores endocrinos. Por otra parte, su persistencia en el medio ambiente, resistencia a la degradación, bioacumulación y capacidad de transporte atmosférico entre las diversas fases medioambientales hace que sean considerados actualmente como compuestos peligrosos para el ser humano.

  2. Analysis of image plane's Illumination in Image-forming System

    International Nuclear Information System (INIS)

    Duan Lihua; Zeng Yan'an; Zhang Nanyangsheng; Wang Zhiguo; Yin Shiliang

    2011-01-01

    In the detection of optical radiation, the detecting accuracy is affected by optic power distribution of the detector's surface to a large extent. In addition, in the image-forming system, the quality of the image is greatly determined by the uniformity of the image's illumination distribution. However, in the practical optical system, affected by the factors such as field of view, false light and off axis and so on, the distribution of the image's illumination tends to be non uniform, so it is necessary to discuss the image plane's illumination in image-forming systems. In order to analyze the characteristics of the image-forming system at a full range, on the basis of photometry, the formulas to calculate the illumination of the imaging plane have been summarized by the numbers. Moreover, the relationship between the horizontal offset of the light source and the illumination of the image has been discussed in detail. After that, the influence of some key factors such as aperture angle, off-axis distance and horizontal offset on illumination of the image has been brought forward. Through numerical simulation, various theoretical curves of those key factors have been given. The results of the numerical simulation show that it is recommended to aggrandize the diameter of the exit pupil to increase the illumination of the image. The angle of view plays a negative role in the illumination distribution of the image, that is, the uniformity of the illumination distribution can be enhanced by compressing the angle of view. Lastly, it is proved that telecentric optical design is an effective way to advance the uniformity of the illumination distribution.

  3. Types for BioAmbients

    Directory of Open Access Journals (Sweden)

    Sara Capecchi

    2010-02-01

    Full Text Available The BioAmbients calculus is a process algebra suitable for representing compartmentalization, molecular localization and movements between compartments. In this paper we enrich this calculus with a static type system classifying each ambient with group types specifying the kind of compartments in which the ambient can stay. The type system ensures that, in a well-typed process, ambients cannot be nested in a way that violates the type hierarchy. Exploiting the information given by the group types, we also extend the operational semantics of BioAmbients with rules signalling errors that may derive from undesired ambients' moves (i.e. merging incompatible tissues. Thus, the signal of errors can help the modeller to detect and locate unwanted situations that may arise in a biological system, and give practical hints on how to avoid the undesired behaviour.

  4. Illuminate Knowledge Elements in Geoscience Literature

    Science.gov (United States)

    Ma, X.; Zheng, J. G.; Wang, H.; Fox, P. A.

    2015-12-01

    There are numerous dark data hidden in geoscience literature. Efficient retrieval and reuse of those data will greatly benefit geoscience researches of nowadays. Among the works of data rescue, a topic of interest is illuminating the knowledge framework, i.e. entities and relationships, embedded in documents. Entity recognition and linking have received extensive attention in news and social media analysis, as well as in bioinformatics. In the domain of geoscience, however, such works are limited. We will present our work on how to use knowledge bases on the Web, such as ontologies and vocabularies, to facilitate entity recognition and linking in geoscience literature. The work deploys an un-supervised collective inference approach [1] to link entity mentions in unstructured texts to a knowledge base, which leverages the meaningful information and structures in ontologies and vocabularies for similarity computation and entity ranking. Our work is still in the initial stage towards the detection of knowledge frameworks in literature, and we have been collecting geoscience ontologies and vocabularies in order to build a comprehensive geoscience knowledge base [2]. We hope the work will initiate new ideas and collaborations on dark data rescue, as well as on the synthesis of data and knowledge from geoscience literature. References: 1. Zheng, J., Howsmon, D., Zhang, B., Hahn, J., McGuinness, D.L., Hendler, J., and Ji, H. 2014. Entity linking for biomedical literature. In Proceedings of ACM 8th International Workshop on Data and Text Mining in Bioinformatics, Shanghai, China. 2. Ma, X. Zheng, J., 2015. Linking geoscience entity mentions to the Web of Data. ESIP 2015 Summer Meeting, Pacific Grove, CA.

  5. Image illumination enhancement with an objective no-reference measure of illumination assessment based on Gaussian distribution mapping

    Directory of Open Access Journals (Sweden)

    Gholamreza Anbarjafari

    2015-12-01

    Full Text Available Illumination problems have been an important concern in many image processing applications. The pattern of the histogram on an image introduces meaningful features; hence within the process of illumination enhancement, it is important not to destroy such information. In this paper we propose a method to enhance image illumination using Gaussian distribution mapping which also keeps the information laid on the pattern of the histogram on the original image. First a Gaussian distribution based on the mean and standard deviation of the input image will be calculated. Simultaneously a Gaussian distribution with the desired mean and standard deviation will be calculated. Then a cumulative distribution function of each of the Gaussian distributions will be calculated and used in order to map the old pixel value onto the new pixel value. Another important issue in the field of illumination enhancement is absence of a quantitative measure for the assessment of the illumination of an image. In this research work, a quantitative measure indicating the illumination state, i.e. contrast level and brightness of an image, is also proposed. The measure utilizes the estimated Gaussian distribution of the input image and the Kullback-Leibler Divergence (KLD between the estimated Gaussian and the desired Gaussian distributions to calculate the quantitative measure. The experimental results show the effectiveness and the reliability of the proposed illumination enhancement technique, as well as the proposed illumination assessment measure over conventional and state-of-the-art techniques.

  6. Reforma constitucional y ambiente

    Directory of Open Access Journals (Sweden)

    Teodoro Bustamante

    2013-09-01

    Full Text Available América Latina está atravesada por una ola de reformas constitucionales. Sus causas, las expectativas que ellas despiertan, los riesgos que se han asociado al proceso de lucha política en su entorno, son temas de un análisis fundamentalmente político; pero hay algunos aspectos en los cuales ese debate tiene una directa repercusión sobre el tema ambiental. En el caso del Ecuador, esto se refleja en el hecho de que una de las innovaciones que se proponen, se refieren a una nueva forma de abordar los temas ambientales, básicamente se establecen Derechos de la Naturaleza.

  7. Improved illumination system of laparoscopes using an aspherical lens array.

    Science.gov (United States)

    Wu, Rengmao; Qin, Yi; Hua, Hong

    2016-06-01

    The current fiber-based illumination systems of laparoscopes are unable to uniformly illuminate a large enough area in abdomen due to the limited numerical aperture (NA) of the fiber bundle. Most energy is concentrated in a small region at the center of the illumination area. This limitation becomes problematic in laparoscopes which require capturing a wide field of view. In this paper, we propose an aspherical lens array which is used to direct the outgoing rays from the fiber bundle of laparoscope to produce a more uniformly illuminated, substantially larger field coverage than standalone fiber source. An intensity feedback method is developed to design the aspherical lens unit for extended non-Lambertian sources, which is the key to the design of this lens array. By this method, the lens unit is obtained after only one iteration, and the lens array is constructed by Boolean operation. Then, the ray-tracing technique is used to verify the design. Further, the lens array is fabricated and experimental tests are performed. The results clearly show that the well-illuminated area is increased to about 0.107m(2) from 0.02m(2) (about 5x larger than a standard fiber illumination source). More details of the internal organs can be clearly observed under this improved illumination condition, which also reflects the significant improvement in the optical performance of the laparoscope.

  8. Design and simulation of double annular illumination mode for microlithography

    Science.gov (United States)

    Song, Qiang; Zhu, Jing; Yang, Baoxi; Liu, Lei; Wang, Jun; Huang, Huijie

    2013-08-01

    Methods of generating various illumination patterns remain as an attractive and important micro-optics research area for the development of resolution enhancement in advanced lithography system. In the current illumination system of lithography machine, off-axis illumination is widely used as an effective approach to enhance the resolution and increase the depth of focus (DOF). This paper proposes a novel illumination mode generation unit, which transform conventional mode to double annular shaped radial polarized (DARP) mode for improving the resolution of micro-lithography. Through LightToolsTM software simulation, double annular shaped mode is obtained from the proposed generation unit. The mathematical expressions of the radius variation of inner and outer rings are deduced. The impacts of conventional and dual concentric annular illumination pattern on critical dimension uniformity were simulated on an isolated line, square hole and corner. Lithography performance was compared between DARP illumination mode and corresponding single annular modes under critical dimension of 45nm. As a result, DARP illumination mode can improve the uniformity of aerial image at 45nm node through pitch varied in 300-500 nm to a certain extent.

  9. Real-time global illumination on mobile device

    Science.gov (United States)

    Ahn, Minsu; Ha, Inwoo; Lee, Hyong-Euk; Kim, James D. K.

    2014-02-01

    We propose a novel method for real-time global illumination on mobile devices. Our approach is based on instant radiosity, which uses a sequence of virtual point lights in order to represent the e ect of indirect illumination. Our rendering process consists of three stages. With the primary light, the rst stage generates a local illumination with the shadow map on GPU The second stage of the global illumination uses the re ective shadow map on GPU and generates the sequence of virtual point lights on CPU. Finally, we use the splatting method of Dachsbacher et al 1 and add the indirect illumination to the local illumination on GPU. With the limited computing resources in mobile devices, a small number of virtual point lights are allowed for real-time rendering. Our approach uses the multi-resolution sampling method with 3D geometry and attributes simultaneously and reduce the total number of virtual point lights. We also use the hybrid strategy, which collaboratively combines the CPUs and GPUs available in a mobile SoC due to the limited computing resources in mobile devices. Experimental results demonstrate the global illumination performance of the proposed method.

  10. Nonuniformity mitigation of beam illumination in heavy ion inertial fusion

    International Nuclear Information System (INIS)

    Kawata, S; Noguchi, K; Suzuki, T; Kurosaki, T; Barada, D; Ogoyski, A I; Zhang, W; Xie, J; Zhang, H; Dai, D

    2014-01-01

    In inertial fusion, a target DT fuel should be compressed to typically 1000 times the solid density. The target implosion nonuniformity is introduced by a driver beam’s illumination nonuniformity, for example. The target implosion should be robust against the implosion nonuniformities. In this paper, the requirement for implosion uniformity is first discussed. The implosion non-uniformity should be less than a few percent. The implosion dynamics is also briefly reviewed in heavy ion inertial fusion (HIF). Heavy ions deposit their energy inside the target energy absorber, and the energy deposition layer is rather thick, depending on the ion particle energy. Then nonuniformity mitigation mechanisms of the heavy ion beam (HIB) illumination in HIF are discussed. A density valley appears in the energy absorber, and the large-scale density valley also works as a radiation energy confinement layer, which contributes to a radiation energy smoothing. In HIF, wobbling heavy ion beam illumination was also introduced to realize a uniform implosion. The wobbling HIB axis oscillation is precisely controlled. In the wobbling HIBs’ illumination, the illumination nonuniformity oscillates in time and space on an HIF target. The oscillating-HIB energy deposition may contribute to the reduction of the HIBs’ illumination nonuniformity by its smoothing effect on the HIB illumination nonuniformity and also by a growth mitigation effect on the Rayleigh–Taylor instability. (invited comment)

  11. Alternative Remedies

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Alternative Remedies Font ... medical treatment prescribed by their healthcare provider. Using this type of alternative therapy along with traditional treatments is ...

  12. Alternative Fuels

    Science.gov (United States)

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  13. Alternating Hemiplegia

    Science.gov (United States)

    ... to the symptoms of the disorder. View Full Definition Treatment Drug therapy including verapamil may help to reduce the ... the more serious form of alternating hemiplegia × ... Definition Alternating hemiplegia is a rare neurological disorder that ...

  14. Effects of chromatic image statistics on illumination induced color differences.

    Science.gov (United States)

    Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

    2013-09-01

    We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

  15. Producción de agroenergía a partir de biomasa en sistemas agroforestales integrados: una alternativa para lograr la seguridad alimentaria y la protección ambiental Agroenergy production from biomass in integrated agroforestry systems: an alternative to achieve food security and environmental protection

    Directory of Open Access Journals (Sweden)

    J Suárez

    2010-09-01

    Full Text Available El objetivo del presente artículo es ofrecer consideraciones acerca de la producción de agroenergía a partir de la biomasa en sistemas agroforestales integrados. En la actualidad a nivel global, marcado por un conjunto de peligros que amenazan la existencia de la especie humana, existe un reto principalmente en el contexto rural: ¿cómo hacer coexistir la agroenergía, la seguridad alimentaria y la protección del medio ambiente?, en presencia de cambios climáticos, degradación ambiental, crisis alimentarias y la creciente contradicción biocombustibles vs alimentos, generada por una insensata política para obtener agrocombustibles de primera generación a partir de grandes extensiones de monocultivos alimentarios, lo que es moralmente rechazable. También los biocombustibles son considerados como una alternativa ecológica a los combustibles fósiles, por su capacidad de reducción en la emisión de gases de efecto invernadero y por promover el desarrollo de comunidades rurales en los países del Sur; ello se potencia en los sistemas agroforestales integrados, en los que se pueden producir biocombustibles, tanto de primera como de segunda generación, sobre todo con la aplicación del concepto de biorrefinería que posibilita convertir la biomasa en múltiples productos, cuyo valor agregado total puede ser mayor que el generado por los combustibles fósiles. A este propósito contribuyen los proyectos internacionales, que promueven la producción integrada y sostenible de alimentos y energía en el contexto de sistemas agroforestales integrados, a escala local. Los autores consideran que la ejecución de proyectos y experiencias sobre agroenergía tiene el propósito principal de lograr la sostenibilidad energética y la seguridad alimentaria a escala local, en el medio rural, teniendo en cuenta la protección del ambiente.The objective of this paper is to offer considerations about agroenergy production from biomass in integrated

  16. IODC 2014 Illumination design problem: the Cinderella Lamp

    Science.gov (United States)

    Cassarly, William J.

    2014-12-01

    For the 3rd time, the International Optical Design Conference (IODC) included an Illumination Design contest. This year, the contest involved designing the illuminator to project the 1950 Walt Disney "Cinderella" movie using a box of optical knick-knacks. The goal of the problem was to provide the highest screen lumens with greater than 30% uniformity. There were 12 entries from 3 different countries. Three different commercial optical/illumination design packages were used. The winning solution, provided by Alois Herkommer, provided 371 screen lumens.

  17. Effect of ultraviolet illumination on metal oxide resistive memory

    KAUST Repository

    Duran Retamal, Jose Ramon

    2014-12-22

    We investigate the photoelectrical and resistive switching properties of Pt/ZnO/Pt capacitor operated in unipolar mode under ultraviolet (UV) illumination. The oxygen photodesorption under UV illumination explains the photoconduction observed in initial and high resistance states. Meanwhile, oxygen readsorption at surface-related defects justifies the different photoresponses dynamics in both states. Finally, UV illumination significantly reduces the variations of resistance in high resistance state, set voltage and reset voltage by 58%, 33%, and 25%, respectively, stabilizing Pt/ZnO/Pt capacitor. Our findings in improved switching uniformity via UV light give physical insight into designing resistive memory devices.

  18. Interactive Dynamic Volume Illumination with Refraction and Caustics.

    Science.gov (United States)

    Magnus, Jens G; Bruckner, Stefan

    2018-01-01

    In recent years, significant progress has been made in developing high-quality interactive methods for realistic volume illumination. However, refraction - despite being an important aspect of light propagation in participating media - has so far only received little attention. In this paper, we present a novel approach for refractive volume illumination including caustics capable of interactive frame rates. By interleaving light and viewing ray propagation, our technique avoids memory-intensive storage of illumination information and does not require any precomputation. It is fully dynamic and all parameters such as light position and transfer function can be modified interactively without a performance penalty.

  19. Effect of ultraviolet illumination on metal oxide resistive memory

    KAUST Repository

    Duran Retamal, Jose Ramon; Kang, Chen-Fang; Ho, Chih-Hsiang; Ke, Jr-Jian; Chang, Wen-Yuan; He, Jr-Hau

    2014-01-01

    We investigate the photoelectrical and resistive switching properties of Pt/ZnO/Pt capacitor operated in unipolar mode under ultraviolet (UV) illumination. The oxygen photodesorption under UV illumination explains the photoconduction observed in initial and high resistance states. Meanwhile, oxygen readsorption at surface-related defects justifies the different photoresponses dynamics in both states. Finally, UV illumination significantly reduces the variations of resistance in high resistance state, set voltage and reset voltage by 58%, 33%, and 25%, respectively, stabilizing Pt/ZnO/Pt capacitor. Our findings in improved switching uniformity via UV light give physical insight into designing resistive memory devices.

  20. High-efficiency VCSEL arrays for illumination and sensing in consumer applications

    Science.gov (United States)

    Seurin, Jean-Francois; Zhou, Delai; Xu, Guoyang; Miglo, Alexander; Li, Daizong; Chen, Tong; Guo, Baiming; Ghosh, Chuni

    2016-03-01

    There has been increased interest in vertical-cavity surface-emitting lasers (VCSELs) for illumination and sensing in the consumer market, especially for 3D sensing ("gesture recognition") and 3D image capture. For these applications, the typical wavelength range of interest is 830~950nm and power levels vary from a few milli-Watts to several Watts. The devices are operated in short pulse mode (a few nano-seconds) with fast rise and fall times for time-of-flight applications (ToF), or in CW/quasi-CW for structured light applications. In VCSELs, the narrow spectrum and its low temperature dependence allows the use of narrower filters and therefore better signal-to-noise performance, especially for outdoor applications. In portable devices (mobile devices, wearable devices, laptops etc.) the size of the illumination module (VCSEL and optics) is a primary consideration. VCSELs offer a unique benefit compared to other laser sources in that they are "surface-mountable" and can be easily integrated along with other electronics components on a printed circuit board (PCB). A critical concern is the power-conversion efficiency (PCE) of the illumination source operating at high temperatures (>50 deg C). We report on various VCSEL based devices and diffuser-integrated modules with high efficiency at high temperatures. Over 40% PCE was achieved in broad temperature range of 0-70 °C for either low power single devices or high power VCSEL arrays, with sub- nano-second rise and fall time. These high power VCSEL arrays show excellent reliability, with extracted mean-time-to-failure (MTTF) of over 500 years at 60 °C ambient temperature and 8W peak output.

  1. Illuminating the Potential of Thin-Film Photovoltaics

    Science.gov (United States)

    Katahara, John K.

    Widespread adoption of photovoltaics (PV) as an alternative electricity source will be predicated upon improvements in price performance compared to traditional power sources. Solution processing of thin-film PV is one promising way to reduce the capital expenditure (CAPEX) of manufacturing solar cells. However, it is imperative that a shift to solution processing does not come at the expense of device performance. One particularly problematic parameter for thin-film PV has historically been the open-circuit voltage (VOC ). As such, there is a pressing need for characterization tools that allow us to quickly and accurately evaluate the potential performance of solution-processed PV absorber layers. This work describes recent progress in developing photoluminescence (PL) techniques for probing optoelectronic quality in semiconductors. We present a generalized model of absorption that encompasses ideal direct-gap semiconductor absorption and various band tail models. This powerful absorption model is used to fit absolute intensity PL data and extract quasi-Fermi level splitting (maximum attainable VOC) for a variety of PV absorber technologies. This technique obviates the need for full device fabrication to get feedback on optoelectronic quality of PV absorber layers and has expedited materials exploration. We then use this absorption model to evaluate the thermodynamic losses due to different band tail cases and estimate tail losses in Cu 2ZnSn(S,Se)4 (CZTSSe). The effect of sub-bandgap absorption on PL quantum yield (PLQY) and voltage is elucidated, and new analysis techniques for extracting VOC from PLQY are validated that reduce computation time and provide us even faster feedback on material quality. We then use PL imaging to develop a mechanism describing the degradation of solution-processed CH3NH3PbI3 films under applied bias and illumination.

  2. Illuminating light-dependent color shifts in core and veneer layers of dental all-ceramics

    Science.gov (United States)

    Lee, Yong-Keun; Cha, Hyun-Suk; Yu, Bin

    2014-09-01

    The color of an object is perceived differently depending on the ambient light conditions. Since dental all-ceramic restorations are fabricated by building up several layers to reproduce the tooth shade, the optical properties of each layer should be optimized for successful shade reproduction. This study aimed to determine the separate contributions of the color shifts in each of the core and veneer layers of all-ceramics by switching the illuminating lights on the color shifts of layered ceramics. Specimens of seven kinds of core ceramics and the corresponding veneer ceramics for each core were fabricated with a layered thickness of 1.5 mm. A sintering ceramic was used as a reference core material. The Commission Internationale de l'Eclairage (CIE) color coordinates of core, veneer, and layered specimens were measured with a spectroradiometer under the CIE illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp) simulating lights. Color shifts of the layered specimens were primarily determined by the CIE a* shifts (D65 to A switch) or by the CIE b* shifts (D65 to F9 switch) of the veneer layer. The color coordinates shifts in the constituent layers differentially influenced those of the layered specimens by the kind of switched lights. Therefore, the optical properties of the constituent layers of all-ceramics should be controlled to reflect these findings.

  3. Validating Firewalls in Mobile Ambients

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Hansen, René Rydhof

    1999-01-01

    The ambient calculus is a calculus of computation that allows active processes (mobile ambients) to move between sites. A firewall is said to be protective whenever it denies entry to attackers not possessing the required passwords. We devise a polynomial time algorithm for rejecting proposed...

  4. Reduced-illuminance autofluorescence imaging in ABCA4-associated retinal degenerations

    Science.gov (United States)

    Cideciyan, Artur V.; Swider, Malgorzata; Aleman, Tomas S.; Roman, Marisa I.; Sumaroka, Alexander; Schwartz, Sharon B.; Stone, Edwin M.; Jacobson, Samuel G.

    2007-05-01

    The health of the retinal pigment epithelium (RPE) can be estimated with autofluorescence (AF) imaging of lipofuscin, which accumulates as a byproduct of retinal exposure to light. Lipofuscin may be toxic to the RPE, and its toxicity may be enhanced by short-wavelength (SW) illumination. The high-intensity and SW excitation light used in conventional AF imaging could, at least in principle, increase the rate of lipofuscin accumulation and/or increase its toxicity. We considered two reduced-illuminance AF imaging (RAFI) methods as alternatives to conventional AF imaging. RAFI methods use either near-infrared (NIR) light or reduced-radiance SW illumination for excitation of fluorophores. We quantified the distribution of RAFI signals in relation to retinal structure and function in patients with the prototypical lipofuscin accumulation disease caused by mutations in ABCA4. There was evidence for two subclinical stages of macular ABCA4 disease involving hyperautofluorescence of both SW- and NIR-RAFI with and without associated loss of visual function. Use of RAFI methods and microperimetry in future clinical trials involving lipofuscinopathies should allow quantification of subclinical disease expression and progression without subjecting the diseased retina/RPE to undue light exposure.

  5. Local Relation Map: A Novel Illumination Invariant Face Recognition Approach

    Directory of Open Access Journals (Sweden)

    Lian Zhichao

    2012-10-01

    Full Text Available In this paper, a novel illumination invariant face recognition approach is proposed. Different from most existing methods, an additive term as noise is considered in the face model under varying illuminations in addition to a multiplicative illumination term. High frequency coefficients of Discrete Cosine Transform (DCT are discarded to eliminate the effect caused by noise. Based on the local characteristics of the human face, a simple but effective illumination invariant feature local relation map is proposed. Experimental results on the Yale B, Extended Yale B and CMU PIE demonstrate the outperformance and lower computational burden of the proposed method compared to other existing methods. The results also demonstrate the validity of the proposed face model and the assumption on noise.

  6. Improving Shadow Suppression for Illumination Robust Face Recognition

    KAUST Repository

    Zhang, Wuming; Zhao, Xi; Morvan, Jean-Marie; Chen, Liming

    2017-01-01

    surface, lighting source and camera sensor, and elaborates the formation of face color appearance. Specifically, the proposed illumination processing pipeline enables the generation of Chromaticity Intrinsic Image (CII) in a log chromaticity space which

  7. Optics, illumination, and image sensing for machine vision II

    International Nuclear Information System (INIS)

    Svetkoff, D.J.

    1987-01-01

    These proceedings collect papers on the general subject of machine vision. Topics include illumination and viewing systems, x-ray imaging, automatic SMT inspection with x-ray vision, and 3-D sensing for machine vision

  8. Circular, explosion-proof lamp provides uniform illumination

    Science.gov (United States)

    1966-01-01

    Circular explosion-proof fluorescent lamp is fitted around a TV camera lens to provide shadowless illumination with a low radiant heat flux. The lamp is mounted in a transparent acrylic housing sealed with clear silicone rubber.

  9. Advanced split-illumination electron holography without Fresnel fringes

    Energy Technology Data Exchange (ETDEWEB)

    Tanigaki, Toshiaki, E-mail: tanigaki-toshiaki@riken.jp [Center for Emergent Matter Science (CEMS), RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Aizawa, Shinji; Park, Hyun Soon [Center for Emergent Matter Science (CEMS), RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Matsuda, Tsuyoshi [Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Harada, Ken [Central Research Laboratory, Hitachi, Ltd., Hatoyama, Saitama 350-0395 (Japan); Shindo, Daisuke [Center for Emergent Matter Science (CEMS), RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan)

    2014-02-01

    Advanced split-illumination electron holography was developed by employing two biprisms in the illuminating system to split an electron wave into two coherent waves and two biprisms in the imaging system to overlap them. A focused image of an upper condenser-biprism filament was formed on the sample plane, and all other filaments were placed in its shadow. This developed system makes it possible to obtain precise reconstructed object waves without modulations due to Fresnel fringes, in addition to holograms of distant objects from reference waves. - Highlights: • Advanced split-illumination electron holography without Fresnel fringes is developed. • Two biprisms are installed in illuminating system of microscope. • High-precision holographic observations of an area locating far from the sample edge become possible.

  10. Advanced split-illumination electron holography without Fresnel fringes

    International Nuclear Information System (INIS)

    Tanigaki, Toshiaki; Aizawa, Shinji; Park, Hyun Soon; Matsuda, Tsuyoshi; Harada, Ken; Shindo, Daisuke

    2014-01-01

    Advanced split-illumination electron holography was developed by employing two biprisms in the illuminating system to split an electron wave into two coherent waves and two biprisms in the imaging system to overlap them. A focused image of an upper condenser-biprism filament was formed on the sample plane, and all other filaments were placed in its shadow. This developed system makes it possible to obtain precise reconstructed object waves without modulations due to Fresnel fringes, in addition to holograms of distant objects from reference waves. - Highlights: • Advanced split-illumination electron holography without Fresnel fringes is developed. • Two biprisms are installed in illuminating system of microscope. • High-precision holographic observations of an area locating far from the sample edge become possible

  11. Effect of different illumination sources on reading and visual performance

    Directory of Open Access Journals (Sweden)

    Male Shiva Ram

    2018-01-01

    Conclusion: This study demonstrates the influence of illumination on reading rate; there were no significant differences between males and females under different illuminations, however, males preferred CFL and females preferred FLUO for faster reading and visual comfort. Interestingly, neither preferred LED or TUNG. Although energy-efficient, visual performance under LED is poor; it is uncomfortable for prolonged reading and causes early symptoms of fatigue.

  12. Geometry of illumination, luminance contrast, and gloss perception

    OpenAIRE

    Leloup, Frédéric; Pointer, Michael R.; Dutré, Philip; Hanselaer, Peter

    2010-01-01

    The influence of both the geometry of illumination and luminance contrast on gloss perception has been examined using the method of paired comparison. Six achromatic glass samples having different lightness were illuminated by two light sources. Only one of these light sources was visible in reflection by the observer. By separate adjustment of the intensity of both light sources, the luminance of both the reflected image and the adjacent off-specular surroundings could be individually varied...

  13. Illumination normalization based on simplified local binary patterns for a face verification system

    NARCIS (Netherlands)

    Tao, Q.; Veldhuis, Raymond N.J.

    2007-01-01

    Illumination normalization is a very important step in face recognition. In this paper we propose a simple implementation of Local Binary Patterns, which effectively reduces the variability caused by illumination changes. In combination with a likelihood ratio classifier, this illumination

  14. Spiral wobbling beam illumination uniformity in HIF fuel target implosion

    Directory of Open Access Journals (Sweden)

    Kawata S.

    2013-11-01

    Full Text Available A few % wobbling-beam illumination nonuniformity is realized in heavy ion inertial confinement fusion (HIF throughout the heavy ion beam (HIB driver pulse by a newly introduced spiraling beam axis motion in the first two rotations. The wobbling HIB illumination was proposed to realize a uniform implosion in HIF. However, the initial imprint of the wobbling HIBs was a serious problem and introduces a large unacceptable energy deposition nonuniformity. In the wobbling HIBs illumination, the illumination nonuniformity oscillates in time and space. The oscillating-HIB energy deposition may produce a time-dependent implosion acceleration, which reduces the Rayleigh-Taylor (R-T growth [Laser Part. Beams 11, 757 (1993, Nuclear Inst. Methods in Phys. Res. A 606, 152 (2009, Phys. Plasmas 19, 024503 (2012] and the implosion nonuniformity. The wobbling HIBs can be generated in HIB accelerators and the oscillating frequency may be several 100 MHz ∼ 1 GHz [Phys. Rev. Lett. 104, 254801 (2010]. Three-dimensional HIBs illumination computations present that the few % wobbling HIBs illumination nonuniformity oscillates with the same wobbling HIBs frequency.

  15. Real-time Global Illumination by Simulating Photon Mapping

    DEFF Research Database (Denmark)

    Larsen, Bent Dalgaard

    2004-01-01

    This thesis introduces a new method for simulating photon mapping in realtime. The method uses a variety of both CPU and GPU based algorithms for speeding up the different elements in global illumination. The idea behind the method is to calculate each illumination element individually in a progr......This thesis introduces a new method for simulating photon mapping in realtime. The method uses a variety of both CPU and GPU based algorithms for speeding up the different elements in global illumination. The idea behind the method is to calculate each illumination element individually...... in a progressive and efficient manner. This has been done by analyzing the photon mapping method and by selecting efficient methods, either CPU based or GPU based, which replaces the original photon mapping algorithms. We have chosen to focus on the indirect illumination and the caustics. In our method we first...... divide the photon map into several photon maps in order to make local updates possible. Then indirect illumination is added using light maps that are selectively updated by using selective photon tracing on the CPU. The final gathering step is calculated by using fragment programs and GPU based...

  16. Advanced illumination control algorithm for medical endoscopy applications

    Science.gov (United States)

    Sousa, Ricardo M.; Wäny, Martin; Santos, Pedro; Morgado-Dias, F.

    2015-05-01

    CMOS image sensor manufacturer, AWAIBA, is providing the world's smallest digital camera modules to the world market for minimally invasive surgery and one time use endoscopic equipment. Based on the world's smallest digital camera head and the evaluation board provided to it, the aim of this paper is to demonstrate an advanced fast response dynamic control algorithm of the illumination LED source coupled to the camera head, over the LED drivers embedded on the evaluation board. Cost efficient and small size endoscopic camera modules nowadays embed minimal size image sensors capable of not only adjusting gain and exposure time but also LED illumination with adjustable illumination power. The LED illumination power has to be dynamically adjusted while navigating the endoscope over changing illumination conditions of several orders of magnitude within fractions of the second to guarantee a smooth viewing experience. The algorithm is centered on the pixel analysis of selected ROIs enabling it to dynamically adjust the illumination intensity based on the measured pixel saturation level. The control core was developed in VHDL and tested in a laboratory environment over changing light conditions. The obtained results show that it is capable of achieving correction speeds under 1 s while maintaining a static error below 3% relative to the total number of pixels on the image. The result of this work will allow the integration of millimeter sized high brightness LED sources on minimal form factor cameras enabling its use in endoscopic surgical robotic or micro invasive surgery.

  17. Lunar South Pole Illumination: Review, Reassessment, and Power System Implications

    Science.gov (United States)

    Fincannon, James

    2007-01-01

    This paper reviews past analyses and research related to lunar south pole illumination and presents results of independent illumination analyses using an analytical tool and a radar digital elevation model. The analysis tool enables assessment at most locations near the lunar poles for any time and any year. Average illumination fraction, energy storage duration, solar/horizon terrain elevation profiles and illumination fraction profiles are presented for various highly illuminated sites which have been identified for manned or unmanned operations. The format of the data can be used by power system designers to develop mass optimized solar and energy storage systems. Data are presented for the worse case lunar day (a critical power planning bottleneck) as well as three lunar days during lunar south pole winter. The main site under consideration by present lunar mission planners (on the Crater Shackleton rim) is shown to have, for the worse case lunar day, a 0.71 average illumination fraction and 73 to 117 hours required for energy storage (depending on power system type). Linking other sites and including towers at either site are shown to not completely eliminate the need for energy storage.

  18. Salud ambiental: conceptos y actividades

    Directory of Open Access Journals (Sweden)

    Gonzalo A. Ordóñez

    2000-03-01

    Full Text Available La finalidad del trabajo es aportar información y propuestas conceptuales que faciliten la tarea de quienes tienen a su cargo la sistematización institucional de la salud ambiental. Se hace un análisis de la noción de "ambiente" para la cual se sugiere una definición, y se examina el lugar de la salud ambiental en el contexto de los problemas ambientales y sus vertientes "verde" y "azul". Se examinan denominaciones equivalentes de salud ambiental y se introducen los servicios de salud ambiental. Se proporcionan varias definiciones y se da la oficial de salud ambiental adoptada por la OMS en Sofía, Bulgaria (1993. A continuación se transcriben las áreas básicas que a la salud ambiental le han asignado diversas organizaciones o reuniones, como la OPS, la OMS, el Programa 21 y otros. A partir de aquí se construye un repertorio bastante completo de áreas y subáreas y se encuentra que todos los listados son, en realidad, una reunión asistemática de tres tipos de constituyentes: determinantes (factores o hechos de la realidad física, procesos (conjuntos de intervenciones y funciones (conjuntos de acciones de gestión, los cuales pueden enfocarse matricialmente y llevan a individualizar actividades de los servicios de salud ambiental. Se proponen unas reglas de operación que permiten, en una especie de álgebra, construir expresiones para especificar con precisión las actividades y sus agregados. De este modo se logra disponer de un lenguaje simbólico común que puede ayudar a la intercomunicación, enseñanza e investigación en el ámbito de la salud ambiental.

  19. Illumination Conditions of the Lunar Polar Regions Using LOLA Topography

    Science.gov (United States)

    Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.; Torrence, M. H.

    2011-01-01

    We use high-resolution altimetry data obtained by the Lunar Orbiter Laser Altimeter instrument onboard the Lunar Reconnaissance Orbiter to characterize present illumination conditions in the polar regions of the Moon. Compared to previous studies, both the spatial and temporal extent of the simulations are increased significantly, as well as the coverage (fill ratio) of the topographic maps used, thanks to the 28 Hz firing rate of the five-beam instrument. We determine the horizon elevation in a number of directions based on 240 m-resolution polar digital elevation models reaching down to 75 latitude. The illumination of both polar regions extending to 80 can be calculated for any geometry from those horizon longitudinal profiles. We validated our modeling with recent Lunar Reconnaissance Orbiter Wide-Angle Camera images. We assessed the extent of permanently shadowed regions (PSRs, defined as areas that never receive direct solar illumination), and obtained total areas generally larger than previous studies (12,866 and 16,055 km2, in the north and south respectively). We extended our direct illumination model to account for singly-scattered light, and found that every PSR does receive some amount of scattered light during the year. We conducted simulations over long periods (several 18.6-years lunar precession cycles) with a high temporal resolution (6 h), and identified the most illuminated locations in the vicinity of both poles. Because of the importance of those sites for exploration and engineering considerations, we characterized their illumination more precisely over the near future. Every year, a location near the Shackleton crater rim in the south polar region is sunlit continuously for 240 days, and its longest continuous period in total darkness is about 1.5 days. For some locations small height gains ( 10 m) can dramatically improve their average illumination and reduce the night duration, rendering some of those particularly attractive energy-wise as

  20. Alternative wastewatersystems

    DEFF Research Database (Denmark)

    Dyck-Madsen, Søren; Hoffmann, Birgitte; Gabriel, Søren

    1999-01-01

    The report:-  Communicates experiences from Swedish buildings from the establishment and running of alternative wastewater systems. Communicates pictures of alternative buildings and wastewater systems in Sweden. Gives a short evaluation of the performance and the sustainability of the systems....

  1. Wide-area SWIR arrays and active illuminators

    Science.gov (United States)

    MacDougal, Michael; Hood, Andrew; Geske, Jon; Wang, Chad; Renner, Daniel; Follman, David; Heu, Paula

    2012-01-01

    We describe the factors that go into the component choices for a short wavelength (SWIR) imager, which include the SWIR sensor, the lens, and the illuminator. We have shown the factors for reducing dark current, and shown that we can achieve well below 1.5 nA/cm2 for 15 μm devices at 7°C. We have mated our InGaAs detector arrays to 640x512 readout integrated integrated circuits (ROICs) to make focal plane arrays (FPAs). In addition, we have fabricated high definition 1920x1080 FPAs for wide field of view imaging. The resulting FPAs are capable of imaging photon fluxes with wavelengths between 1 and 1.6 microns at low light levels. The dark current associated with these FPAs is extremely low, exhibiting a mean dark current density of 0.26 nA/cm2 at 0°C. FLIR has also developed a high definition, 1920x1080, 15 um pitch SWIR sensor. In addition, FLIR has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide low-speckle illumination, provide artifact-free imagery versus conventional laser illuminators.

  2. Accommodating multiple illumination sources in an imaging colorimetry environment

    Science.gov (United States)

    Tobin, Kenneth W., Jr.; Goddard, James S., Jr.; Hunt, Martin A.; Hylton, Kathy W.; Karnowski, Thomas P.; Simpson, Marc L.; Richards, Roger K.; Treece, Dale A.

    2000-03-01

    Researchers at the Oak Ridge National Laboratory have been developing a method for measuring color quality in textile products using a tri-stimulus color camera system. Initial results of the Imaging Tristimulus Colorimeter (ITC) were reported during 1999. These results showed that the projection onto convex sets (POCS) approach to color estimation could be applied to complex printed patterns on textile products with high accuracy and repeatability. Image-based color sensors used for on-line measurement are not colorimetric by nature and require a non-linear transformation of the component colors based on the spectral properties of the incident illumination, imaging sensor, and the actual textile color. Our earlier work reports these results for a broad-band, smoothly varying D65 standard illuminant. To move the measurement to the on-line environment with continuously manufactured textile webs, the illumination source becomes problematic. The spectral content of these light sources varies substantially from the D65 standard illuminant and can greatly impact the measurement performance of the POCS system. Although absolute color measurements are difficult to make under different illumination, referential measurements to monitor color drift provide a useful indication of product quality. Modifications to the ITC system have been implemented to enable the study of different light sources. These results and the subsequent analysis of relative color measurements will be reported for textile products.

  3. Automatic residue removal for high-NA extreme illumination

    Science.gov (United States)

    Moon, James; Nam, Byong-Sub; Jeong, Joo-Hong; Kong, Dong-Ho; Nam, Byung-Ho; Yim, Dong Gyu

    2007-10-01

    An epidemic for smaller node has been that, as the device architecture shrinks, lithography process requires high Numerical Aperture (NA), and extreme illumination system. This, in turn, creates many lithography problems such as low lithography process margin (Depth of Focus, Exposure Latitude), unstable Critical Dimension (CD) uniformity and restricted guideline for device design rule and so on. Especially for high NA, extreme illumination such as immersion illumination systems, above all the related problems, restricted design rule due to forbidden pitch is critical and crucial issue. This forbidden pitch is composed of numerous optical effects but majority of these forbidden pitch compose of photo resist residue and these residue must be removed to relieve some room for already tight design rule. In this study, we propose automated algorithm to remove photo resist residue due to high NA and extreme illumination condition. This algorithm automatically self assembles assist patterns based on the original design layout, therefore insuring the safety and simplicity of the generated assist pattern to the original design and removes any resist residue created by extreme illumination condition. Also we tested our automated algorithm on full chip FLASH memory device and showed the residue removal effect by using commercial verification tools as well as on actual test wafer.

  4. Spectrally optimal illuminations for diabetic retinopathy detection in retinal imaging

    Science.gov (United States)

    Bartczak, Piotr; Fält, Pauli; Penttinen, Niko; Ylitepsa, Pasi; Laaksonen, Lauri; Lensu, Lasse; Hauta-Kasari, Markku; Uusitalo, Hannu

    2017-04-01

    Retinal photography is a standard method for recording retinal diseases for subsequent analysis and diagnosis. However, the currently used white light or red-free retinal imaging does not necessarily provide the best possible visibility of different types of retinal lesions, important when developing diagnostic tools for handheld devices, such as smartphones. Using specifically designed illumination, the visibility and contrast of retinal lesions could be improved. In this study, spectrally optimal illuminations for diabetic retinopathy lesion visualization are implemented using a spectrally tunable light source based on digital micromirror device. The applicability of this method was tested in vivo by taking retinal monochrome images from the eyes of five diabetic volunteers and two non-diabetic control subjects. For comparison to existing methods, we evaluated the contrast of retinal images taken with our method and red-free illumination. The preliminary results show that the use of optimal illuminations improved the contrast of diabetic lesions in retinal images by 30-70%, compared to the traditional red-free illumination imaging.

  5. Comparative analysis of face recognition techniques with illumination variation

    International Nuclear Information System (INIS)

    Jondhale, K C; Waghmare, L M

    2010-01-01

    Illumination variation is one of the major challenges in the face recognition. To deal with this problem, this paper presents comparative analysis of three different techniques. First, the DCT is employed to compensate for illumination variations in the logarithm domain. Since illumination variation lies mainly in the low frequency band, an appropriate number of DCT coefficients are truncated to reduce the variations under different lighting conditions. The nearest neighbor classifier based on Euclidean distance is employed for classification. Second, the performance of PCA is checked on normalized image. PCA is a technique used to reduce multidimensional data sets to a lower dimension for analysis. Third, LDA based methods gives a satisfactory result under controlled lighting condition. But its performance under large illumination variation is not satisfactory. So, the performance of LDA is checked on normalized image. Experimental results on the Yale B and ORL database show that the proposed approach of application of PCA and LDA on normalized dataset improves the performance significantly for the face images with large illumination variations.

  6. Effects of illumination on image reconstruction via Fourier ptychography

    Science.gov (United States)

    Cao, Xinrui; Sinzinger, Stefan

    2017-12-01

    The Fourier ptychographic microscopy (FPM) technique provides high-resolution images by combining a traditional imaging system, e.g. a microscope or a 4f-imaging system, with a multiplexing illumination system, e.g. an LED array and numerical image processing for enhanced image reconstruction. In order to numerically combine images that are captured under varying illumination angles, an iterative phase-retrieval algorithm is often applied. However, in practice, the performance of the FPM algorithm degrades due to the imperfections of the optical system, the image noise caused by the camera, etc. To eliminate the influence of the aberrations of the imaging system, an embedded pupil function recovery (EPRY)-FPM algorithm has been proposed [Opt. Express 22, 4960-4972 (2014)]. In this paper, we study how the performance of FPM and EPRY-FPM algorithms are affected by imperfections of the illumination system using both numerical simulations and experiments. The investigated imperfections include varying and non-uniform intensities, and wavefront aberrations. Our study shows that the aberrations of the illumination system significantly affect the performance of both FPM and EPRY-FPM algorithms. Hence, in practice, aberrations in the illumination system gain significant influence on the resulting image quality.

  7. How alternative are alternative fuels?

    OpenAIRE

    Soffritti, Tiziana; Danielis, Romeo

    1998-01-01

    Could alternative fuel vehicles contribute to a substantial reduction of air pollution? Is there a market for alternative fuel vehicles? Could a market be created via a pollution tax? The article answers these questions on the basis of the available estimates.

  8. Alternative detox.

    Science.gov (United States)

    Ernst, E

    2012-01-01

    The concept that alternative therapies can eliminate toxins and toxicants from the body, i.e. 'alternative detox' (AD) is popular. Selected textbooks and articles on the subject of AD. The principles of AD make no sense from a scientific perspective and there is no clinical evidence to support them. The promotion of AD treatments provides income for some entrepreneurs but has the potential to cause harm to patients and consumers. In alternative medicine, simplistic but incorrect concepts such as AD abound. AREAS TIMELY FOR RESEARCH: All therapeutic claims should be scientifically tested before being advertised-and AD cannot be an exception.

  9. Anti-glare LED lamps with adjustable illumination light field.

    Science.gov (United States)

    Chen, Yung-Sheng; Lin, Chung-Yi; Yeh, Chun-Ming; Kuo, Chie-Tong; Hsu, Chih-Wei; Wang, Hsiang-Chen

    2014-03-10

    We introduce a type of LED light-gauge steel frame lamp with an adjustable illumination light field that does not require a diffusion plate. Base on the Monte Carlo ray tracing method, this lamp has a good glare rating (GR) of 17.5 at 3050 lm. Compared with the traditional LED light-gauge steel frame lamp (without diffusion plate), the new type has low GR. The adjustability of the illumination light field could improve the zebra effect caused by the inadequate illumination light field of the lamp. Meanwhile, we adopt the retinal image analysis to discuss the influence of GR on vision. High GR could reflect stray light on the retinal image, which will reduce vision clarity and hasten the feeling of eye fatigue.

  10. Video repairing under variable illumination using cyclic motions.

    Science.gov (United States)

    Jia, Jiaya; Tai, Yu-Wing; Wu, Tai-Pang; Tang, Chi-Keung

    2006-05-01

    This paper presents a complete system capable of synthesizing a large number of pixels that are missing due to occlusion or damage in an uncalibrated input video. These missing pixels may correspond to the static background or cyclic motions of the captured scene. Our system employs user-assisted video layer segmentation, while the main processing in video repair is fully automatic. The input video is first decomposed into the color and illumination videos. The necessary temporal consistency is maintained by tensor voting in the spatio-temporal domain. Missing colors and illumination of the background are synthesized by applying image repairing. Finally, the occluded motions are inferred by spatio-temporal alignment of collected samples at multiple scales. We experimented on our system with some difficult examples with variable illumination, where the capturing camera can be stationary or in motion.

  11. Separate effects of background and illumination on lightness

    Directory of Open Access Journals (Sweden)

    Zdravković Sunčica

    2007-01-01

    Full Text Available Four experiments attempted to establish an effect of context on lightness. Lightness is one of the dimensions of color and it varies from black to white. Most of our stimuli were inspired by simultaneous lightness contrast illusion. First two experiments contrast the size of an effect produced by the change of background color vs. the change in illumination. The third experiment deals with different type of illusions, where the effect is obtained through the appearance of multiple illumination levels. The last experiment takes into account the ratio of the target and the background. The results reveal the size of effects produced separately by the background color and illumination level and suggest the prime importance of background. Also there are other factors such as reflectance range in the scene, incremental and decremental targets, and 2D vs. 3D representation.

  12. A back-illuminated megapixel CMOS image sensor

    Science.gov (United States)

    Pain, Bedabrata; Cunningham, Thomas; Nikzad, Shouleh; Hoenk, Michael; Jones, Todd; Wrigley, Chris; Hancock, Bruce

    2005-01-01

    In this paper, we present the test and characterization results for a back-illuminated megapixel CMOS imager. The imager pixel consists of a standard junction photodiode coupled to a three transistor-per-pixel switched source-follower readout [1]. The imager also consists of integrated timing and control and bias generation circuits, and provides analog output. The analog column-scan circuits were implemented in such a way that the imager could be configured to run in off-chip correlated double-sampling (CDS) mode. The imager was originally designed for normal front-illuminated operation, and was fabricated in a commercially available 0.5 pn triple-metal CMOS-imager compatible process. For backside illumination, the imager was thinned by etching away the substrate was etched away in a post-fabrication processing step.

  13. Numerical analysis of lateral illumination lightpipes using elliptical grooves

    Science.gov (United States)

    Sánchez-Guerrero, Guillermo E.; Viera-González, Perla M.; Martínez-Guerra, Edgar; Ceballos-Herrera, Daniel E.

    2017-09-01

    Lightpipes are used for illumination in applications such as back-lighting or solar cell concentrators due to the high irradiance uniformity, but its optimal design requires several parameters. This work presents a procedure to design a square lightpipe to control the light-extraction on its lateral face using commercial LEDs placed symmetrically in the lightpipe frontal face. We propose the use of grooves using total internal reflection placed successively in the same face of extraction to control the area of emission. The LED area of emission is small compared with the illuminated area, and, as expected, the lateral face total power is attenuated. These grooves reduce the optical elements in the system and can control areas of illumination. A mathematical and numerical analysis are presented to determine the dependencies on the light-extraction.

  14. Local and Global Illumination in the Volume Rendering Integral

    Energy Technology Data Exchange (ETDEWEB)

    Max, N; Chen, M

    2005-10-21

    This article is intended as an update of the major survey by Max [1] on optical models for direct volume rendering. It provides a brief overview of the subject scope covered by [1], and brings recent developments, such as new shadow algorithms and refraction rendering, into the perspective. In particular, we examine three fundamentals aspects of direct volume rendering, namely the volume rendering integral, local illumination models and global illumination models, in a wavelength-independent manner. We review the developments on spectral volume rendering, in which visible light are considered as a form of electromagnetic radiation, optical models are implemented in conjunction with representations of spectral power distribution. This survey can provide a basis for, and encourage, new efforts for developing and using complex illumination models to achieve better realism and perception through optical correctness.

  15. Geometry of illumination, luminance contrast, and gloss perception.

    Science.gov (United States)

    Leloup, Frédéric B; Pointer, Michael R; Dutré, Philip; Hanselaer, Peter

    2010-09-01

    The influence of both the geometry of illumination and luminance contrast on gloss perception has been examined using the method of paired comparison. Six achromatic glass samples having different lightness were illuminated by two light sources. Only one of these light sources was visible in reflection by the observer. By separate adjustment of the intensity of both light sources, the luminance of both the reflected image and the adjacent off-specular surroundings could be individually varied. It was found that visual gloss appraisal did not correlate with instrumentally measured specular gloss; however, psychometric contrast seemed to be a much better correlate. It has become clear that not only the sample surface characteristics determine gloss perception: the illumination geometry could be an even more important factor.

  16. Alternatives to Pyrotechnic Distress Signals; Laboratory and Field Studies

    Science.gov (United States)

    2015-03-01

    distance for positive identity and location. The spectral characteristics (“color”) of the light are important, as daytime and nighttime vision are most...ambient illumination. Figure 10. Laboratory setup. 5.2.1 Projector Specifications The scene projector was a Panasonic PT-AE80000U home cinema ...three were identical to lab signals: 4Hz group/interrupt in white, red, and cyan. For the field testing, experimenters mounted the signal generator

  17. Difference in opalescence of restorative materials by the illuminant.

    Science.gov (United States)

    Yu, Bin; Lee, Yong-Keun

    2009-08-01

    To determine the differences in the opalescence parameter (OP) of indirect and direct resin composites, veneer ceramics and bovine enamel relative to the CIE standard illuminants D65, A and F2. BelleGlass NG (indirect resin; 10 shades) and Estelite Sigma (direct resin; 12 shades), and 4 shades of veneer ceramics were investigated. Bovine enamel was used as a reference. Reflected and transmitted colors of specimens were measured relative to the illuminants D65, A and F2 with a reflection spectrophotometer. OP values relative to the three illuminants [OP(D65), OP(A) and OP(F2)], difference in OP (DeltaOP) and OP difference ratio relative to OP(D65) [DeltaOP/OP(D65)] by the change of illuminants were calculated. Within each restorative material, DeltaOP and DeltaOP/OP(D65) values were analyzed with two-way analysis of variance (ANOVA), with the fixed factors of the shade designation and the combination of illuminants (alpha=0.05). DeltaOP and DeltaOP/OP(D65) values were influenced by the two factors within each restorative material based on two-way ANOVA. High opalescent materials showed higher DeltaOP values. OP(D65) was lower than OP(F2) and OP(A) values. Restorative materials showed lower DeltaOP/OP(D65) values than bovine enamel. Correlation coefficients between OP values relative to different illuminants were higher than 0.961 (Popalescence properties as compared with natural tooth enamel.

  18. Three-dimensional illumination procedure for photodynamic therapy of dermatology

    Science.gov (United States)

    Hu, Xiao-ming; Zhang, Feng-juan; Dong, Fei; Zhou, Ya

    2014-09-01

    Light dosimetry is an important parameter that affects the efficacy of photodynamic therapy (PDT). However, the irregular morphologies of lesions complicate lesion segmentation and light irradiance adjustment. Therefore, this study developed an illumination demo system comprising a camera, a digital projector, and a computing unit to solve these problems. A three-dimensional model of a lesion was reconstructed using the developed system. Hierarchical segmentation was achieved with the superpixel algorithm. The expected light dosimetry on the targeted lesion was achieved with the proposed illumination procedure. Accurate control and optimization of light delivery can improve the efficacy of PDT.

  19. 3D Imaging with Structured Illumination for Advanced Security Applications

    Energy Technology Data Exchange (ETDEWEB)

    Birch, Gabriel Carisle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dagel, Amber Lynn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kast, Brian A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Collin S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Three-dimensional (3D) information in a physical security system is a highly useful dis- criminator. The two-dimensional data from an imaging systems fails to provide target dis- tance and three-dimensional motion vector, which can be used to reduce nuisance alarm rates and increase system effectiveness. However, 3D imaging devices designed primarily for use in physical security systems are uncommon. This report discusses an architecture favorable to physical security systems; an inexpensive snapshot 3D imaging system utilizing a simple illumination system. The method of acquiring 3D data, tests to understand illumination de- sign, and software modifications possible to maximize information gathering capability are discussed.

  20. Estimating Outdoor Illumination Conditions Based on Detection of Dynamic Shadows

    DEFF Research Database (Denmark)

    Madsen, Claus B.; Lal, Brajesh Behari

    2013-01-01

    into the image stream to achieve realistic Augmented Reality where the shading and the shadowing of virtual objects is consistent with the real scene. Other techniques require the presence of a known object, a light probe, in the scene for estimating illumination. The technique proposed here works in general......The paper proposes a technique for estimation outdoor illumination conditions in terms of sun and sky radiances directly from pixel values of dynamic shadows detected in video sequences produved by a commercial stereo camera. The technique is applied to the rendering of virtual object...

  1. Nonthermal Effects of Photon Illumination on Surface Diffusion

    International Nuclear Information System (INIS)

    Ditchfield, R.; Llera-Rodriguez, D.; Seebauer, E.G.

    1998-01-01

    Nonthermal influences of photon illumination on surface diffusion at high temperatures have been measured experimentally for the first time. Activation energies and preexponential factors for diffusion of germanium and indium on silicon change substantially in response to illumination by photons having energies greater than the substrate band gap. Results depend on doping type. Ionization of surface vacancies by photogenerated charge carriers seems to play a key role. The results have significant implications for aspects of microelectronics fabrication governed by surface mobility. copyright 1998 The American Physical Society

  2. Coating strategy for enhancing illumination uniformity in a lithographic condenser

    International Nuclear Information System (INIS)

    Gaines, D.P.; Vernon, S.P.; Sommargren, G.E.; Kania, D.R.

    1995-01-01

    A three-element Koehler condenser system has been fabricated, characterized, and integrated into an EUV lithographic system. The multilayer coatings deposited on the optics were designed to provide optimal radiation transport efficiency and illumination uniformity. Extensive EUV characterization measurements performed on the individual optics and follow-on system measurements indicated that the condenser was operating close to design goals. Multilayer d-spacings were within 0.05 nm of specifications, and reflectances were approximately 60%. Illumination uniformity was better than ±10%. The broadband transport efficiency was 11%

  3. Multiple projection optical diffusion tomography with plane wave illumination

    International Nuclear Information System (INIS)

    Markel, Vadim A; Schotland, John C

    2005-01-01

    We describe a new data collection scheme for optical diffusion tomography in which plane wave illumination is combined with multiple projections in the slab imaging geometry. Multiple projection measurements are performed by rotating the slab around the sample. The advantage of the proposed method is that the measured data are more compatible with the dynamic range of most commonly used detectors. At the same time, multiple projections improve image quality by mutually interchanging the depth and transverse directions, and the scanned (detection) and integrated (illumination) surfaces. Inversion methods are derived for image reconstructions with extremely large data sets. Numerical simulations are performed for fixed and rotated slabs

  4. Illuminance Level in the Urban Fabric and in the Room

    DEFF Research Database (Denmark)

    Iversen, Anne; Nielsen, Toke Rammer; Svendsen, Svend

    2011-01-01

    The decisions made on the urban planning level could influence the building design at later stages. Many studies have shown that the utilisation of daylight in buildings would result in significant savings in electricity consumption for lighting, while creating a higher quality indoor environment...... of the exterior illuminance levels on fac¸ades with the interior illuminance levels on the working plane. The paper also explains an easy to use tool (EvUrbanplan) developed by the authors, which was applied to their findings in the early stages of urban planning to ensure daylight optimisation in the buildings....

  5. The possible ocular hazards of LED dental illumination applications.

    Science.gov (United States)

    Stamatacos, Catherine; Harrison, Janet L

    2013-01-01

    The use of high-intensity illumination via Light-Emitting Diode (LED) headlamps is gaining in popularity with dentists and student dentists. Practitioners are using LED headlamps together with magnifying loupes, overhead LED illumination and fiber-optic dental handpieces for long periods of time. Although most manufacturers of these LED illuminators advertise that their devices emit "white" light, these still consist of two spectral bands--the blue spectral band, with its peak at 445 nm, and the green with its peak at 555 nm. While manufacturers suggest that their devices emit "white" light, spectral components of LED lights from different companies are significantly different. Dental headlamp manufacturers strive to create a white LED, and they advertise that this type of light emitted from their product offers bright white-light illumination. However, the manufacturing of a white LED light is done through selection of a white LED-type based on the peak blue strength in combination with the green peak strength and thus creating a beam-forming optic, which determines the beam quality. Some LED illuminators have a strong blue-light component versus the green-light component. Blue-light is highly energized and is close in the color spectrum to ultraviolet-light. The hazards of retinal damage with the use of high-intensity blue-lights has been well-documented. There is limited research regarding the possible ocular hazards of usage of high-intensity illuminating LED devices. Furthermore, the authors have found little research, standards, or guidelines examining the possible safety issues regarding the unique dental practice setting consisting of the combined use of LED illumination systems. Another unexamined component is the effect of high-intensity light reflective glare and magnification back to the practitioner's eyes due to the use of water during dental procedures. Based on the result of Dr. Janet Harrison's observations of beginning dental students in a

  6. Conhecimento, interdisciplinaridade e Psicologia Ambiental

    Directory of Open Access Journals (Sweden)

    Ombretta Romice

    2005-01-01

    Full Text Available Responde às questões - como os métodos da Psicologia Ambiental devem ser discutidos em um enquadramento interdisciplinar; a Psicologia Ambiental pede alguma abordagem metodológica especial; como a intervenção ambiental é determinada pela interdisciplinaridade; quais são estas disciplinas e como elas se relacionam entre si - baseando-se em experiências profissionais como orientador em um projeto com comunidade, com habitação popular e exclusão social em vários países da Europa, e como consultora. Conclui que as abordagens usadas pelas diferentes profissões são muito separadas, e que apenas metas comuns não são suficientes, sendo também necessários um treino conjunto e identidade de valores.

  7. Simulation and comparison of the illuminance, uniformity, and efficiency of different forms of lighting used in basketball court illumination.

    Science.gov (United States)

    Sun, Wen-Shing; Tien, Chuen-Lin; Tsuei, Chih-Hsuan; Pan, Jui-Wen

    2014-10-10

    We simulate and compare the illuminance, uniformity, and efficiency of metal-halide lamps, white LED light sources, and hybrid light box designs combining sunlight and white LED lighting used for indoor basketball court illumination. According to the optical simulation results and our examination of real situations, we find that hybrid light box designs combining sunlight and white LEDs do perform better than either metal-halide lamps or white LED lights. An evaluation of the sunlight concentrator system used in our inverted solar cell shows that the energy consumption of stadium lighting can be reduced significantly.

  8. Color fidelity of chromatic distributions by triad illuminant comparison

    NARCIS (Netherlands)

    Lucassen, M.P.; Gevers, T.; Gijsenij, A.

    2011-01-01

    Performance measures for quantifying human color constancy and computational color constancy are very different. The former relate to measurements on individual object colors whereas the latter relate to the accuracy of the estimated illuminant. To bridge this gap, we propose a psychophysical method

  9. Review of the illumination problems pertaining to South African collieries.

    CSIR Research Space (South Africa)

    Pardoe, DR

    1994-01-01

    Full Text Available In 1992, a proposal was submitted to SIMRAC for a two year programme of work with the overall objective of conducting a general review of problems and techniques related to underground colliery illumination, particular emphasis on identifying means...

  10. Noise tolerant illumination optimization applied to display devices

    Science.gov (United States)

    Cassarly, William J.; Irving, Bruce

    2005-02-01

    Display devices have historically been designed through an iterative process using numerous hardware prototypes. This process is effective but the number of iterations is limited by the time and cost to make the prototypes. In recent years, virtual prototyping using illumination software modeling tools has replaced many of the hardware prototypes. Typically, the designer specifies the design parameters, builds the software model, predicts the performance using a Monte Carlo simulation, and uses the performance results to repeat this process until an acceptable design is obtained. What is highly desired, and now possible, is to use illumination optimization to automate the design process. Illumination optimization provides the ability to explore a wider range of design options while also providing improved performance. Since Monte Carlo simulations are often used to calculate the system performance but those predictions have statistical uncertainty, the use of noise tolerant optimization algorithms is important. The use of noise tolerant illumination optimization is demonstrated by considering display device designs that extract light using 2D paint patterns as well as 3D textured surfaces. A hybrid optimization approach that combines a mesh feedback optimization with a classical optimizer is demonstrated. Displays with LED sources and cold cathode fluorescent lamps are considered.

  11. Stroboscopic effect : Contrast threshold function and dependence on illumination level

    NARCIS (Netherlands)

    Perz, M.; Sekulovski, D.; Vogels, I.; Heynderickx, I.

    2018-01-01

    The stroboscopic visibility measure (SVM) is a method used to quantify the stroboscopic effect visibility in general illumination application. SVM has been defined previously based on a limited number of frequencies and participants. To validate and extend SVM, five perception experiments are

  12. Illumination Profile & Dispersion Variation Effects on Radial Velocity Measurements

    Science.gov (United States)

    Grieves, Nolan; Ge, Jian; Thomas, Neil B.; Ma, Bo; Li, Rui; SDSS-III

    2015-01-01

    The Multi-object APO Radial-Velocity Exoplanet Large-Area Survey (MARVELS) measures radial velocities using a fiber-fed dispersed fixed-delay interferometer (DFDI) with a moderate dispersion spectrograph. This setup allows a unique insight into the 2D illumination profile from the fiber on to the dispersion grating. Illumination profile investigations show large changes in the profile over time and fiber location. These profile changes are correlated with dispersion changes and long-term radial velocity offsets, a major problem within the MARVELS radial velocity data. Characterizing illumination profiles creates a method to both detect and correct radial velocity offsets, allowing for better planet detection. Here we report our early results from this study including improvement of radial velocity data points from detected giant planet candidates. We also report an illumination profile experiment conducted at the Kitt Peak National Observatory using the EXPERT instrument, which has a DFDI mode similar to MARVELS. Using profile controlling octagonal-shaped fibers, long term offsets over a 3 month time period were reduced from ~50 m/s to within the photon limit of ~4 m/s.

  13. Husserl's Illumination of the Breakthrough of Logical Investigations

    African Journals Online (AJOL)

    denise

    the example Husserl offers of the room where the lights go off in order to illuminate the breakthrough for ... correspondence theory of truth, and his main concern seems to be to ..... The advantage of Husserl's example is that it tries to situate the ...

  14. On the illumination of neutron star accretion discs

    Science.gov (United States)

    Wilkins, D. R.

    2018-03-01

    The illumination of the accretion disc in a neutron star X-ray binary by X-rays emitted from (or close to) the neutron star surface is explored through general relativistic ray tracing simulations. The applicability of the canonical suite of relativistically broadened emission line models (developed for black holes) to discs around neutron stars is evaluated. These models were found to describe well emission lines from neutron star accretion discs unless the neutron star radius is larger than the innermost stable orbit of the accretion disc at 6 rg or the disc is viewed at high inclination, above 60° where shadowing of the back side of the disc becomes important. Theoretical emissivity profiles were computed for accretion discs illuminated by hotspots on the neutron star surfaces, bands of emission and emission by the entirety of the hot, spherical star surface and in all cases, the emissivity profile of the accretion disc was found to be well represented by a single power law falling off slightly steeper than r-3. Steepening of the emissivity index was found where the emission is close to the disc plane and the disc can appear truncated when illuminated by a hotspot at high latitude. The emissivity profile of the accretion disc in Serpens X-1 was measured and found to be consistent with a single unbroken power law with index q=3.5_{-0.4}^{+0.3}, suggestive of illumination by the boundary layer between the disc and neutron star surface.

  15. Electrical Power and Illumination Systems. Energy Technology Series.

    Science.gov (United States)

    Center for Occupational Research and Development, Inc., Waco, TX.

    This course in electrical power and illumination systems is one of 16 courses in the Energy Technology Series developed for an Energy Conservation-and-Use Technology curriculum. Intended for use in two-year postsecondary technical institutions to prepare technicians for employment, the courses are also useful in industry for updating employees in…

  16. Improving Shadow Suppression for Illumination Robust Face Recognition

    KAUST Repository

    Zhang, Wuming

    2017-10-13

    2D face analysis techniques, such as face landmarking, face recognition and face verification, are reasonably dependent on illumination conditions which are usually uncontrolled and unpredictable in the real world. An illumination robust preprocessing method thus remains a significant challenge in reliable face analysis. In this paper we propose a novel approach for improving lighting normalization through building the underlying reflectance model which characterizes interactions between skin surface, lighting source and camera sensor, and elaborates the formation of face color appearance. Specifically, the proposed illumination processing pipeline enables the generation of Chromaticity Intrinsic Image (CII) in a log chromaticity space which is robust to illumination variations. Moreover, as an advantage over most prevailing methods, a photo-realistic color face image is subsequently reconstructed which eliminates a wide variety of shadows whilst retaining the color information and identity details. Experimental results under different scenarios and using various face databases show the effectiveness of the proposed approach to deal with lighting variations, including both soft and hard shadows, in face recognition.

  17. Quantum Illumination-Based Target Detection and Discrimination

    Science.gov (United States)

    2014-06-30

    photodiode with an estimated quantum efficiency of 85% and an ultralow-noise transimpedance amplifier . Compared with to our initial QI measurements...demonstrated high signal-to-noise ratio (SNR) quantum-illumination target detection in a lossy, noisy environment using an optical parametric amplifier ...Research Triangle Park, NC 27709-2211 quantum communication, target detection, entanglement, parametric downconversion, optical parametric amplifiers

  18. Novel technique for solar power illumination using plastic optical fibres

    Science.gov (United States)

    Munisami, J.; Kalymnios, D.

    2008-09-01

    Plastic Optical Fibres (POF) were developed almost 3 decades ago. They are mainly used for short haul data communications (up to 1 km with data rates up to 1 Gbps). Over the years, POF has found applications in many other areas including solar energy transport for illumination. In such an application, light is collected from the sun and is directed into a space which needs to be illuminated. The use of fibres and more specifically POF, in daylighting systems, started only a few years ago. Several approaches have been investigated and we have seen the development of a few commercial products. The market however, has not really taken off for these technologies simply because of their enormous price tags. It is important to note that the use of POF in these designs has been limited to the function of POF as the transmission medium only. We propose a novel solar illumination technique using POF as both the light collecting/concentrating mechanism and the transmission medium. By modifying the structure of the fibre, solar light can be directed into the fibre by using an analogous process to fibre side emission but, in the reverse. We shall report on the solar light capturing efficiency of POF as modified by several types of external imperfections introduced onto the fibre. One major advantage of our proposed approach lies in the fact that we aim to eliminate at least one of the two axes of sun tracking that is currently used in existing solar illumination systems.

  19. Super-resolution thermographic imaging using blind structured illumination

    Science.gov (United States)

    Burgholzer, Peter; Berer, Thomas; Gruber, Jürgen; Mayr, Günther

    2017-07-01

    Using an infrared camera for thermographic imaging allows the contactless temperature measurement of many surface pixels simultaneously. From the measured surface data, the structure below the surface, embedded inside a sample or tissue, can be reconstructed and imaged, if heated by an excitation light pulse. The main drawback in active thermographic imaging is the degradation of the spatial resolution with the imaging depth, which results in blurred images for deeper lying structures. We circumvent this degradation by using blind structured illumination combined with a non-linear joint sparsity reconstruction algorithm. We demonstrate imaging of a line pattern and a star-shaped structure through a 3 mm thick steel sheet with a resolution four times better than the width of the thermal point-spread-function. The structured illumination is realized by parallel slits cut in an aluminum foil, where the excitation coming from a flashlight can penetrate. This realization of super-resolution thermographic imaging demonstrates that blind structured illumination allows thermographic imaging without high degradation of the spatial resolution for deeper lying structures. The groundbreaking concept of super-resolution can be transferred from optics to diffusive imaging by defining a thermal point-spread-function, which gives the principle resolution limit for a certain signal-to-noise ratio, similar to the Abbe limit for a certain optical wavelength. In future work, the unknown illumination pattern could be the speckle pattern generated by a short laser pulse inside a light scattering sample or tissue.

  20. System for illuminating a region for isotopically selective photoexcitation

    International Nuclear Information System (INIS)

    Debaryshe, P.G.; Janes, G.S.; Levy, R.H.; Lindenmeier, C.W.

    1979-01-01

    A method is described to improve laser beam utilization in isotope separation techniques (using laser induced isotopically selective photoexcitation) by increasing the probability of photon absorption without extreme beam propagation lengths. For this purpose an optical reflection system has been designed for illuminating substantially all of three-dimensional space of a transversely flowing vapor with multiple traversals of a beam of radiation. (UK)

  1. All-solution processed organic solar cells with top illumination

    NARCIS (Netherlands)

    Patil, B.R.; Shanmugam, S.; Teunissen, J.P.; Galagan, Y.

    2015-01-01

    All-solution processed organic solar cells with inverted device architecture were demonstrated. Devices contain opaque bottom electrodes and semitransparent top electrodes, resulting in top illuminated devices. Nanoparticles-based Ag ink was used for inkjet printing both top and bottom electrodes.

  2. Occupancy-based illumination control of LED lighting systems

    NARCIS (Netherlands)

    Caicedo Fernandez, D.R.; Pandharipande, A.; Leus, G.

    2011-01-01

    Light emitting diode (LED)-based systems are considered to be the future of lighting. We consider the problem of energy-efficient illumination control of such systems. Energy-efficient system design is based on two aspects: localised information on occupancy and optimisation of dimming levels of the

  3. Two-way visible light communication and illumination with LEDs

    NARCIS (Netherlands)

    Li, S.; Pandharipande, A.; Willems, F.M.J.

    2017-01-01

    Visible light communications (VLC) with light-emitting diodes (LEDs) has attracted applications, such as data communications, lighting control, and light interaction. In this paper, we propose a system by which two LED devices are used for two-way VLC while also providing illumination. We consider

  4. LED power consumption in joint illumination and communication system

    NARCIS (Netherlands)

    Deng, X.; Wu, Y.; Khalid, A.M.; Long, X.; Linnartz, J.-P.M.G.

    This paper addresses the power penalty in an illumination LED caused by visible light communication (VLC). This study models the extra power consumption of the LED by taking into account the convex relation between the dissipated electrical power versus the LED current on one hand and the concave

  5. Multiple speckle illumination for optical-resolution photoacoustic imaging

    Science.gov (United States)

    Poisson, Florian; Stasio, Nicolino; Moser, Christophe; Psaltis, Demetri; Bossy, Emmanuel

    2017-03-01

    Optical-resolution photoacoustic microscopy offers exquisite and specific contrast to optical absorption. Conventional approaches generally involves raster scanning a focused spot over the sample. Here, we demonstrate that a full-field illumination approach with multiple speckle illumination can also provide diffraction-limited optical-resolution photoacoustic images. Two different proof-of-concepts are demonstrated with micro-structured test samples. The first approach follows the principle of correlation/ghost imaging,1, 2 and is based on cross-correlating photoacoustic signals under multiple speckle illumination with known speckle patterns measured during a calibration step. The second approach is a speckle scanning microscopy technique, which adapts the technique proposed in fluorescence microscopy by Bertolotti and al.:3 in our work, spatially unresolved photoacoustic measurements are performed for various translations of unknown speckle patterns. A phase-retrieval algorithm is used to reconstruct the object from the knowledge of the modulus of its Fourier Transform yielded by the measurements. Because speckle patterns naturally appear in many various situations, including propagation through biological tissue or multi-mode fibers (for which focusing light is either very demanding if not impossible), speckle-illumination-based photoacoustic microscopy provides a powerful framework for the development of novel reconstruction approaches, well-suited to compressed sensing approaches.2

  6. Ambient cosmology and spacetime singularities

    International Nuclear Information System (INIS)

    Antoniadis, Ignatios; Cotsakis, Spiros

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary. (orig.)

  7. Ambient cosmology and spacetime singularities

    CERN Document Server

    Antoniadis, Ignatios

    2015-01-01

    We present a new approach to the issues of spacetime singularities and cosmic censorship in general relativity. This is based on the idea that standard 4-dimensional spacetime is the conformal infinity of an ambient metric for the 5-dimensional Einstein equations with fluid sources. We then find that the existence of spacetime singularities in four dimensions is constrained by asymptotic properties of the ambient 5-metric, while the non-degeneracy of the latter crucially depends on cosmic censorship holding on the boundary.

  8. Cosmic alternatives?

    Science.gov (United States)

    Gregory, Ruth

    2009-04-01

    "Cosmologists are often in error but never in doubt." This pithy characterization by the Soviet physicist Lev Landau sums up the raison d'être of Facts and Speculations in Cosmology. Authors Jayant Narlikar and Geoffrey Burbidge are proponents of a "steady state" theory of cosmology, and they argue that the cosmological community has become fixated on a "Big Bang" dogma, suppressing alternative viewpoints. This book very much does what it says on the tin: it sets out what is known in cosmology, and puts forward the authors' point of view on an alternative to the Big Bang.

  9. Effect of illumination on photoluminescence properties of porous silicon

    International Nuclear Information System (INIS)

    Naddaf, M.; Hamadeh, H.

    2008-11-01

    Porous silicon (PS) layers were formed by photo-electrochemical etching of both p-type and n-type single crystal wafers in HF based solution. During the etching process, the silicon wafer was illuminated by a halogen lamp light guided by an optical fiber through a monochromator or diode lasers at different power density and wavelengths (480,533,580 and 635 nm). The optical and structural properties of the prepared PS samples have been investigated by using temperature dependent photoluminescence (PL) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, contact angle (CA) measurements, optical microscope and atomic force microscope (AFM). Beside the strong red-yellow PL band, a blue PL band has been observed only in the PS samples formed under the illumination with low power and short wavelengths (480-580 nm) light. In the near infrared (IR) spectral range, a new PL band at 850 nm was observed in p-type PS samples, which prepared under darkness or illumination with 635 nm of low power light. Temperature dependent PL measurements showed that, in contrast to the main IR PL band at around 1100 nm, the intensity of this new band increases on increasing the temperature. These changes in the PL properties was correlated with the illumination induced-structural and morphological modifications in the PS skeleton. In particular, the FTIR analysis showed that the chemical groups and bonds constituting the PS skeleton, such as, SiH, SiO bonds and silanol SiOH group play key role in deciding the PL emission intensity and blue shift. The study proved that the illumination parameters during the photo-electrochemical etching process can be utilized for tailoring a porous layer with novel optical and structural properties. (Authors)

  10. Effect of illumination on photoluminescence properties of porous silicon

    International Nuclear Information System (INIS)

    Naddaf, M.; Hamadeh, H.

    2009-01-01

    Porous silicon (PS) layers were formed by photo-electrochemical etching of both p-type and n-type single crystal wafers in HF based solution. During the etching process, the silicon wafer was illuminated by a halogen lamp light guided by an optical fiber through a monochromator or diode lasers at different power density and wavelengths (480,533,580 and 635 nm). The optical and structural properties of the prepared PS samples have been investigated by using temperature dependent photoluminescence (PL) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, contact angle (CA) measurements, optical microscope and atomic force microscope (AFM). Beside the strong red-yellow PL band, a blue PL band has been observed only in the PS samples formed under the illumination with low power and short wavelengths (480-580 nm) light. In the near infrared (IR) spectral range, a new PL band at 850 nm was observed in p-type PS samples, which prepared under darkness or illumination with 635 nm of low power light. Temperature dependent PL measurements showed that, in contrast to the main IR PL band at around 1100 nm, the intensity of this new band increases on increasing the temperature. These changes in the PL properties was correlated with the illumination induced-structural and morphological modifications in the PS skeleton. In particular, the FTIR analysis showed that the chemical groups and bonds constituting the PS skeleton, such as, SiH, SiO bonds and silanol SiOH group play key role in deciding the PL emission intensity and blue shift. The study proved that the illumination parameters during the photo-electrochemical etching process can be utilized for tailoring a porous layer with novel optical and structural properties. (Authors)

  11. Light illumination intensity dependence of photovoltaic parameter in polymer solar cells with ammonium heptamolybdate as hole extraction layer.

    Science.gov (United States)

    Liu, Zhiyong; Niu, Shengli; Wang, Ning

    2018-01-01

    A low-temperature, solution-processed molybdenum oxide (MoO X ) layer and a facile method for polymer solar cells (PSCs) is developed. The PSCs based on a MoO X layer as the hole extraction layer (HEL) is a significant advance for achieving higher photovoltaic performance, especially under weaker light illumination intensity. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements show that the (NH 4 ) 6 Mo 7 O 24 molecule decomposes and forms the molybdenum oxide (MoO X ) molecule when undergoing thermal annealing treatment. In this study, PSCs with the MoO X layer as the HEL exhibited better photovoltaic performance, especially under weak light illumination intensity (from 100 to 10mWcm -2 ) compared to poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-based PSCs. Analysis of the current density-voltage (J-V) characteristics at various light intensities provides information on the different recombination mechanisms in the PSCs with a MoO X and PEDOT:PSS layer as the HEL. That the slopes of the open-circuit voltage (V OC ) versus light illumination intensity plots are close to 1 unity (kT/q) reveals that bimolecular recombination is the dominant and weaker monomolecular recombination mechanism in open-circuit conditions. That the slopes of the short-circuit current density (J SC ) versus light illumination intensity plots are close to 1 reveals that the effective charge carrier transport and collection mechanism of the MoO X /indium tin oxide (ITO) anode is the weaker bimolecular recombination in short-circuit conditions. Our results indicate that MoO X is an alternative candidate for high-performance PSCs, especially under weak light illumination intensity. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Growing Alternatives

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin

    2014-01-01

    From 2014, Anhui Province will pilot a reform of the residential land market in China, thus integrating rural Anhui in the national housing market. In contrast, artist and activist Ou Ning has proposed the Bishan time money currency, intending to establish an alternative economic circuit in Bishan...

  13. Alternative Veier

    DEFF Research Database (Denmark)

    Kruse, Tove Elisabeth; Salamonsen, Anita

    reflektioner omkring patienters brug af og erfaringer med alternativ behandling. Patientorganisationer, organisatoner for alternative behandlere og organisationer for læger og medicinstuderende har læst bogens patienthistorier og deres perspektiver lægges frem. Til slut i bogen diskuteres betydningen af de...

  14. 76 FR 22665 - Release of Final Document Related to the Review of the National Ambient Air Quality Standards for...

    Science.gov (United States)

    2011-04-22

    ... criteria. The revised air quality criteria reflect advances in scientific knowledge on the effects of the... National Ambient Air Quality Standards, contains staff analyses of the scientific bases for alternative... Document Related to the Review of the National Ambient Air Quality Standards for Particulate Matter AGENCY...

  15. Large-solid-angle illuminators for extreme ultraviolet lithography with laser plasmas

    International Nuclear Information System (INIS)

    Kubiak, G.D.; Tichenor, D.A.; Sweatt, W.C.; Chow, W.W.

    1995-06-01

    Laser Plasma Sources (LPSS) of extreme ultraviolet radiation are an attractive alternative to synchrotron radiation sources for extreme ultraviolet lithography (EUVL) due to their modularity, brightness, and modest size and cost. To fully exploit the extreme ultraviolet power emitted by such sources, it is necessary to capture the largest possible fraction of the source emission half-sphere while simultaneously optimizing the illumination stationarity and uniformity on the object mask. In this LDRD project, laser plasma source illumination systems for EUVL have been designed and then theoretically and experimentally characterized. Ellipsoidal condensers have been found to be simple yet extremely efficient condensers for small-field EUVL imaging systems. The effects of aberrations in such condensers on extreme ultraviolet (EUV) imaging have been studied with physical optics modeling. Lastly, the design of an efficient large-solid-angle condenser has been completed. It collects 50% of the available laser plasma source power at 14 nm and delivers it properly to the object mask in a wide-arc-field camera

  16. TERCEIRO SETOR E MEIO AMBIENTE

    OpenAIRE

    MELO, MARINA FÉLIX DE

    2012-01-01

    Objetivamos discutir, brevemente, como têm se dado as discussões sobre o Terceiro Setor brasileiro e, particularmente, sobre as ONGs que atuam em defesa do meio ambiente, levantando questionamentos acerca das limitações enfrentadas pelo Terceiro Setor neste contexto

  17. La crisis del medio ambiente

    Directory of Open Access Journals (Sweden)

    Juan Carlos Quintero Vélez

    2013-07-01

    Full Text Available Este artículo, introducción al tema del medio ambiente, pretende proporcionar conceptos básicos para analizar y dimensionar el impacto que genera el hombre sobre los sistemas que soportan la vida. Para entender estos problemas, es indispensable partir de un análisis básico de la relación entre el hombre actual, su medio ambiente, sus necesidades y sus actividades. El autor revisa los antecedentes, las causas y las consecuencias de la crisis ambiental internacional, e intenta dar explicación a la problemática nacionalen este campo, y establecer los puntos más críticos en Colombia. Finalmente, con base en los parámetros establecidos por el gobierno, se presenta el concepto de“desarrollo sostenible" como modelo que interrelaciona los procesos económicos, sociales y tecnológicos con el medio ambiente.

  18. The persuasiveness of ambient intelligence

    NARCIS (Netherlands)

    Aarts, E.H.L.; Markopoulos, P.; Ruyter, de B.E.R.; Petkovic, M.; Jonker, W.

    2007-01-01

    Ambient intelligence (AmI) is a novel concept for embedded computing that builds on the large-scale integration of electronic devices into peoples’ surroundings and the ubiquitous availability of digital information to the users of such environments. The concept however is not only concerned with

  19. Ambient intelligence : visualising the future

    NARCIS (Netherlands)

    Aarts, E.H.L.

    2005-01-01

    Ambient Intelligence systems are aimed at making user-system interaction and content consumption a truly positive experience. The endless search for nifty information visualisation mechanism to squeeze yet one more piece of information onto a visual display is surpassed by the challenge to embed

  20. Manufactured Porous Ambient Surface Simulants

    Science.gov (United States)

    Carey, Elizabeth M.; Peters, Gregory H.; Chu, Lauren; Zhou, Yu Meng; Cohen, Brooklin; Panossian, Lara; Green, Jacklyn R.; Moreland, Scott; Backes, Paul

    2016-01-01

    The planetary science decadal survey for 2013-2022 (Vision and Voyages, NRC 2011) has promoted mission concepts for sample acquisition from small solar system bodies. Numerous comet-sampling tools are in development to meet this standard. Manufactured Porous Ambient Surface Simulants (MPASS) materials provide an opportunity to simulate variable features at ambient temperatures and pressures to appropriately test potential sample acquisition systems for comets, asteroids, and planetary surfaces. The original "flavor" of MPASS materials is known as Manufactured Porous Ambient Comet Simulants (MPACS), which was developed in parallel with the development of the Biblade Comet Sampling System (Backes et al., in review). The current suite of MPACS materials was developed through research of the physical and mechanical properties of comets from past comet missions results and modeling efforts, coordination with the science community at the Jet Propulsion Laboratory and testing of a wide range of materials and formulations. These simulants were required to represent the physical and mechanical properties of cometary nuclei, based on the current understanding of the science community. Working with cryogenic simulants can be tedious and costly; thus MPACS is a suite of ambient simulants that yields a brittle failure mode similar to that of cryogenic icy materials. Here we describe our suite of comet simulants known as MPACS that will be used to test and validate the Biblade Comet Sampling System (Backes et al., in review).

  1. Nanomaterials vs Ambient Ultrafine Particles

    DEFF Research Database (Denmark)

    Stone, Vicki; Miller, Mark R.; Clift, Martin J. D.

    2017-01-01

    BACKGROUND: A rich body of literature exists that has demonstrated adverse human health effects following exposure to ambient air particulate matter (PM), and there is strong support for an important role of ultrafine (nanosized) particles. At present, relatively few human health or epidemiology ...

  2. Abstract Interpretation of Mobile Ambients

    DEFF Research Database (Denmark)

    Hansen, René Rydhof; Jensen, J. G.; Nielson, Flemming

    1999-01-01

    We demonstrate that abstract interpretation is useful for analysing calculi of computation such as the ambient calculus (which is based on the p-calculus); more importantly, we show that the entire development can be expressed in a constraint-based formalism that is becoming exceedingly popular...

  3. Shape analysis for Mobile Ambients

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming

    2000-01-01

    The ambient calculus is a calculus of computation that allows active processes to move between sites. We present an analysis inspired by state-of-the-art pointer analyses that safety and accurately predicts which processes may turn up at what sites during the execution of a composite system. The ...... are flexible and scale up to general tree structures admitting powerful restructuring operations....

  4. Ambient intelligence, ethics and privacy

    NARCIS (Netherlands)

    Hoof, van J.; Kort, H.S.M.; Markopoulos, P.; Soede, M.

    2007-01-01

    Networked and ubiquitous information and communication technologies (ICTs) and ambient intelligence are increasingly used in the home environment to facilitate independent living for older adults. These systems collect and disperse a high volume of personal data, which is used for assistance and

  5. Construindo cidadania ambiental na escola

    Directory of Open Access Journals (Sweden)

    Cibele Schwanke

    2014-03-01

    Full Text Available http://dx.doi.org/10.5007/1807-0221.2013v10n16p14 O forte componente transversal da Educação Ambiental possibilita sua inserção em vários espaços e níveis de escolaridade. No ensino fundamental, constitui-se em uma importante ferramenta para criar espaços que permitam a abordagem de temáticas socioambientais atuais, de forma crítica e participativa. O presente trabalho tem como objetivo apresentar o Projeto Construindo Cidadania Ambiental, executado por bolsistas do Grupo PET - Conexões Gestão Ambiental em unidades escolares, explicitando sua filosofia de implantação e resultados obtidos até o momento. Verifica-se que sua natureza interdisciplinar e integrada permite uma efetiva interação com o corpo docente e discente da escola, bem como permite a prática de uma educação ambiental crítica e transformadora.

  6. Co-disposição de lodo centrifugado de Estação de Tratamento de Água (ETA em matriz de concreto: método alternativo de preservação ambiental Disposal of centrifuged sludge from Water Treatment Plant (WTP in concrete matrix: an alternative method for environmental protection

    Directory of Open Access Journals (Sweden)

    C. Hoppen

    2005-06-01

    Full Text Available O crescimento da demanda por água potável tem implicado em um aumento da quantidade de resíduos nas estações de tratamento de água (ETA. Apesar destes terem sido gerados por processo erosivo do solo nos mananciais que antecedem as ETAs, o tratamento químico requerido para a sua remoção obriga a uma disposição correta para não impactar, negativamente, o meio ambiente. Até agora, o destino mais comum para o lodo de ETA são os cursos d'água, mesmo ele sendo considerado um resíduo sólido. Neste trabalho, é proposta alternativa de co-disposição deste resíduo, ainda úmido, em matrizes de concreto, substituindo-se parcialmente seus insumos: os agregados miúdos e o cimento, cuja extração e emprego também causam impacto ambiental. Inicialmente, caracterizaram-se os insumos do concreto (cimento Portland CPII-F 32, areia e brita, além do lodo extraído da ETA Passaúna, localizada na região metropolitana de Curitiba. Para os estudos de dosagem, utilizou-se um concreto-referência (sem adição de lodo e traços de concreto com teores de 3, 5, 7 e 10% de lodo em relação ao peso de areia e em substituição à mesma. Nos concretos resultantes foram avaliadas propriedades tanto no estado fresco quanto no endurecido. O lodo é constituído, praticamente, de compostos de Si, Al e Fe, e do argilomineral do grupo caulinita, tendo teor de umidade em torno de 87%. Nos ensaios de resistência à compressão, as dosagens até 5% apresentaram um f c28 maior que 25 MPa. Para as dosagens com teores de lodo superiores a 5%, o f c28 foi menor, principalmente, para a dosagem de 10%. A análise dos dados permite concluir que os traços com até 5% de lodo podem ser aplicados em situações que vão desde a fabricação de artefatos e blocos até a construção de pavimentos em concreto de cimento Portland. Em relação às misturas com teores acima de 5%, a sua utilização é restrita a aplicações em que a trabalhabilidade não é um par

  7. Efficient illumination of spatial light modulators for optical trapping and manipulation

    DEFF Research Database (Denmark)

    Bañas, Andrew Rafael; Kopylov, Oleksii; Raaby, Peter

    Energy efficiency is always desirable. This is particularly true with lasers that find many applications in research and industry. Combined with spatial light modulators (SLMs) lasers are used for optical trapping and manipulation, sorting, microscopy or biological stimulation1. Besides efficiency....... We have also shown dynamic SLM-generated patterns for materials processing and biological research. To efficiently illuminate an SLM, we used a compact pen-sized GPC-LS in place of an iris. For the same input power, hologram reconstructions are ~3x brighter or alternatively ~3x more focal spots can...... be addressed. This allows better response or increased parallel addressing for e.g. optical manipulation and sorting. Simple yet effective, a GPC-LS could save substantial power in applications that truncate lasers to a specific shape....

  8. A spectral image processing algorithm for evaluating the influence of the illuminants on the reconstructed reflectance

    Science.gov (United States)

    Toadere, Florin

    2017-12-01

    A spectral image processing algorithm that allows the illumination of the scene with different illuminants together with the reconstruction of the scene's reflectance is presented. Color checker spectral image and CIE A (warm light 2700 K), D65 (cold light 6500 K) and Cree TW Series LED T8 (4000 K) are employed for scene illumination. Illuminants used in the simulations have different spectra and, as a result of their illumination, the colors of the scene change. The influence of the illuminants on the reconstruction of the scene's reflectance is estimated. Demonstrative images and reflectance showing the operation of the algorithm are illustrated.

  9. Energy alternatives

    International Nuclear Information System (INIS)

    Sweet, C.

    1987-01-01

    The designated successor to fossil fuels is nuclear fission/fusion and that turns out to be problematic. Alternative Energy Systems have great potential but political forces seem to be hampering their development and introduction. The technologies are flexible in their use and scale of operation. The learning curve will not be short but neither will it be as long and as costly as nuclear power. It is time that this is recognised and some serious rethinking takes place in what presently passes for energy policies both in the industrialised countries and in the Third World. Alternative energy systems are defined and some of them which are relevant to the United Kingdom are discussed. (author)

  10. An overview of LED applications for general illumination

    Science.gov (United States)

    Pelka, David G.; Patel, Kavita

    2003-11-01

    This paper begins by reviewing the current state of development of LEDs, their existing markets as well as their potential for energy conservation and their potential for gaining market share in the general illumination market. It discusses LED metrics such as chip size, lumens per watt, thermal resistance, and the recommended maximum current rating. The paper then goes on to consider the importance of non-imaging optics for both optically efficient and extremely compact LED lighting systems. Finally, microstructures useful for controlling the fields-of-view of LED lighting systems are considered and described in some detail. An extremely efficient and cost effective microstructure, called kinoform diffusers, is shown to have very unique properties that make this technology almost ideal for shaping the output beams of LED lighting systems. It concludes by illustrating some general illumination LED lighting systems

  11. The Direct Lighting Computation in Global Illumination Methods

    Science.gov (United States)

    Wang, Changyaw Allen

    1994-01-01

    Creating realistic images is a computationally expensive process, but it is very important for applications such as interior design, product design, education, virtual reality, and movie special effects. To generate realistic images, state-of-art rendering techniques are employed to simulate global illumination, which accounts for the interreflection of light among objects. In this document, we formalize the global illumination problem into a eight -dimensional integral and discuss various methods that can accelerate the process of approximating this integral. We focus on the direct lighting computation, which accounts for the light reaching the viewer from the emitting sources after exactly one reflection, Monte Carlo sampling methods, and light source simplification. Results include a new sample generation method, a framework for the prediction of the total number of samples used in a solution, and a generalized Monte Carlo approach for computing the direct lighting from an environment which for the first time makes ray tracing feasible for highly complex environments.

  12. Illuminating the Effects of Dynamic Lighting on Student Learning

    Directory of Open Access Journals (Sweden)

    Michael S. Mott

    2012-05-01

    Full Text Available Light is universally understood as essential to the human condition. Yet light quality varies substantially in nature and in controlled environments leading to questions of which artificial light characteristics facilitate maximum learning. Recent research has examined lighting variables of color temperature, and illumination for affecting sleep, mood, focus, motivation, concentration, and work and school performance. This has resulted in artificial light systems intended to support human beings in their actualization through dynamic lighting technology allowing for different lighting conditions per task. A total of 84 third graders were exposed to either focus (6000K-100fc average maintained or normal lighting. Focus lighting led to a higher percentage increase in oral reading fluency performance (36% than did control lighting (17%. No lighting effects were found for motivation or concentration, possibly attributable to the younger age level of respondents as compared with European studies. These findings illuminate the need for further research on artificial light and learning.

  13. Simplied formula for the illuminance in an optical system

    International Nuclear Information System (INIS)

    Burkhard, D.G.; Shealy, D.L.

    1981-01-01

    A formula is derived for the illuminance at any surface in an optical system. By tracing a single ray one can compute the flux density at the image plane or any other position along the ray. The formula involves the ratio of the products of the principal curvatures of the wave front as it approaches each surface to products of the same qualitities after the wave front is refracted at each surface. A procedure is presented for determining the required principal curvatures by generalizing the Coddinton equations to multiple surfaces for both meridional and skew rays. Results are applicable to both sphreical and aspherical surfaces. Since principal radii of curvature specify points on the caustic surfaces, the formula and computation procedure automatically yields the equations for caustic surfaces as a by-product. To illustrate the computation procedure the illuminance and caustic surfaces are derived for an aspherical singlet

  14. Semiconductor surface diffusion: Nonthermal effects of photon illumination

    International Nuclear Information System (INIS)

    Ditchfield, R.; Llera-Rodriguez, D.; Seebauer, E. G.

    2000-01-01

    Nonthermal influences of photon illumination on surface diffusion at high temperatures have been measured experimentally. Activation energies and pre-exponential factors for diffusion of germanium, indium, and antimony on silicon change by up to 0.3 eV and two orders of magnitude, respectively, in response to illumination by photons having energies greater than the substrate band gap. The parameters decrease for n-type material and increase for p-type material. Aided by results from photoreflectance spectroscopy, we suggest that motion of the surface quasi-Fermi-level for minority carriers accounts for much of the effect by changing the charge states of surface vacancies. An additional adatom-vacancy complexation mechanism appears to operate on p-type substrates. The results have significant implications for aspects of microelectronics fabrication by rapid thermal processing that are governed by surface mobility. (c) 2000 The American Physical Society

  15. Topology optimization for optical microlithography with partially coherent illumination

    DEFF Research Database (Denmark)

    Zhou, Mingdong; Lazarov, Boyan Stefanov; Sigmund, Ole

    2017-01-01

    in microlithography/nanolithography. The key steps include (i) modeling the physical inputs of the fabrication process, including the ultraviolet light illumination source and the mask, as the design variables in optimization and (ii) applying physical filtering and heaviside projection for topology optimization......This article revisits a topology optimization design approach for micro-manufacturing and extends it to optical microlithography with partially coherent illumination. The solution is based on a combination of two technologies, the topology optimization and the proximity error correction....... Meanwhile, the performance of the device is optimized and robust with respect to process variations, such as dose/photo-resist variations and lens defocus. A compliant micro-gripper design example is considered to demonstrate the applicability of this approach....

  16. Virtual fringe projection system with nonparallel illumination based on iteration

    International Nuclear Information System (INIS)

    Zhou, Duo; Wang, Zhangying; Gao, Nan; Zhang, Zonghua; Jiang, Xiangqian

    2017-01-01

    Fringe projection profilometry has been widely applied in many fields. To set up an ideal measuring system, a virtual fringe projection technique has been studied to assist in the design of hardware configurations. However, existing virtual fringe projection systems use parallel illumination and have a fixed optical framework. This paper presents a virtual fringe projection system with nonparallel illumination. Using an iterative method to calculate intersection points between rays and reference planes or object surfaces, the proposed system can simulate projected fringe patterns and captured images. A new explicit calibration method has been presented to validate the precision of the system. Simulated results indicate that the proposed iterative method outperforms previous systems. Our virtual system can be applied to error analysis, algorithm optimization, and help operators to find ideal system parameter settings for actual measurements. (paper)

  17. 'No blue' LED solution for photolithography room illumination

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper explored the feasibility of using a LED-based bulb as the illumination light source for photolithography room. A no-blue LED was designed, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that...... color rendering ability than the YFT. Furthermore, LED solution has design flexibility to improve it further. The prototype has been tested with photoresist SU8-2005. Even after 15 days of illumination, no effect was observed. So this LED-based solution was demonstrated to be a very promising light......, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation. Gretagmacbeth color charts were used as a more visional way to compare the two light sources, which shows that our no-blue LED bulb has much better...

  18. Microfluidic mixing triggered by an external LED illumination.

    Science.gov (United States)

    Venancio-Marques, Anna; Barbaud, Fanny; Baigl, Damien

    2013-02-27

    The mixing of confined liquids is a central yet challenging operation in miniaturized devices. Microfluidic mixing is usually achieved with passive mixers that are robust but poorly flexible, or active mixers that offer dynamic control but mainly rely on electrical or mechanical transducers, which increase the fragility, cost, and complexity of the device. Here, we describe the first remote and reversible control of microfluidic mixing triggered by a light illumination simply provided by an external LED illumination device. The approach is based on the light-induced generation of water microdroplets acting as reversible stirrers of two continuous oil phase flows containing samples to be mixed. We demonstrate many cycles of reversible photoinduced transitions between a nonmixing behavior and full homogenization of the two oil phases. The method is cheap, portable, and adaptable to many device configurations, thus constituting an essential brick for the generation of future all-optofluidic chip.

  19. IC design challenges for ambient intelligence

    NARCIS (Netherlands)

    Aarts, E.H.L.; Roovers, R.L.J.

    2003-01-01

    The vision of ambient intelligence opens a world of unprecedented experiences: the interaction of people with electronic devices is changed as contextual awareness, natural interfaces and ubiquitous availability of information are realized. We analyze the consequences of the ambient intelligence

  20. Historical Ambient Air Quality Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Historical Ambient Air Quality Data Inventory contains measured and estimated data on ambient air pollution for use in assessing air quality, assisting in...

  1. Enhanced dielectric properties of ZrO2 thin films prepared in nitrogen ambient by pulsed laser deposition

    International Nuclear Information System (INIS)

    Zhu, J; Li, T L; Pan, B; Zhou, L; Liu, Z G

    2003-01-01

    ZrO 2 thin films were fabricated in O 2 ambient and in N 2 ambient by pulsed laser deposition (PLD), respectively. X-ray diffraction revealed that films prepared at 400 deg. C remained amorphous. The dielectric properties of amorphous ZrO 2 films were investigated by measuring the capacitance-frequency characteristics of Pt/ZrO 2 /Pt capacitor structures. The dielectric constant of the films deposited in N 2 ambient was larger than that of the films deposited in O 2 ambient. The dielectric loss was lower for films prepared in N 2 ambient. Atom force microscopy investigation indicated that films deposited in N 2 ambient had smoother surface than films deposited in O 2 ambient. Capacitance-voltage and current-voltage characteristics were studied. The equivalent oxide thickness (EOT) of films with 6.6 nm physical thickness deposited in N 2 ambient is lower than that of films deposited in O 2 ambient. An EOT of 1.38 nm for the film deposited in N 2 ambient was obtained, while the leakage current density was 94.6 mA cm -2 . Therefore, ZrO 2 thins deposited in N 2 ambient have enhanced dielectric properties due to the incorporation of nitrogen which leads to the formation of Zr-doped nitride interfacial layer, and is suggested to be a potential material for alternative high-k (high dielectric constant) gate dielectric applications

  2. Fully depleted back-illuminated p-channel CCD development

    Energy Technology Data Exchange (ETDEWEB)

    Bebek, Chris J.; Bercovitz, John H.; Groom, Donald E.; Holland, Stephen E.; Kadel, Richard W.; Karcher, Armin; Kolbe, William F.; Oluseyi, Hakeem M.; Palaio, Nicholas P.; Prasad, Val; Turko, Bojan T.; Wang, Guobin

    2003-07-08

    An overview of CCD development efforts at Lawrence Berkeley National Laboratory is presented. Operation of fully-depleted, back-illuminated CCD's fabricated on high resistivity silicon is described, along with results on the use of such CCD's at ground-based observatories. Radiation damage and point-spread function measurements are described, as well as discussion of CCD fabrication technologies.

  3. Illumination adaptation with rapid-response color sensors

    Science.gov (United States)

    Zhang, Xinchi; Wang, Quan; Boyer, Kim L.

    2014-09-01

    Smart lighting solutions based on imaging sensors such as webcams or time-of-flight sensors suffer from rising privacy concerns. In this work, we use low-cost non-imaging color sensors to measure local luminous flux of different colors in an indoor space. These sensors have much higher data acquisition rate and are much cheaper than many o_-the-shelf commercial products. We have developed several applications with these sensors, including illumination feedback control and occupancy-driven lighting.

  4. Talbot self-imaging phenomenon under Bessel beam illumination

    Science.gov (United States)

    Chakraborty, Rijuparna; Chowdhury, Subhajit Dutta; Chakraborty, Ajoy Kumar

    2018-06-01

    In this paper, we report the results of our theoretical studies on the phenomenon of self-imaging of periodic object under the illumination of zero-order Bessel beam. Our theoretical analysis indicates that the self-images are visible only after the walk-off distance of the Bessel beam used. It is also observed that the self-images bend around the optical axis of the setup. Besides, the present study justifies the importance of the conditions stipulated by Montgomery.

  5. Illuminating a dialectical transformative activist stance in education

    Science.gov (United States)

    Ritchie, Stephen M.

    2008-07-01

    In this essay I comment on Stetsenko's (2008) essay that draws together the work of Vygotsky, Piaget and Dewey, as she attempts to counter the `new' reductionist synthesis in public educational policy. While this theoretical work is helpful, it could be enhanced further by illuminating everyday practices of learners. I pose some questions that might provoke ongoing discussions by researchers as they transform collaboratively cultural-historical activity theory.

  6. Design of High Efficiency Illumination for LED Lighting

    OpenAIRE

    Chang, Yong-Nong; Cheng, Hung-Liang; Kuo, Chih-Ming

    2013-01-01

    A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against de...

  7. Random laser illumination: an ideal source for biomedical polarization imaging?

    Science.gov (United States)

    Carvalho, Mariana T.; Lotay, Amrit S.; Kenny, Fiona M.; Girkin, John M.; Gomes, Anderson S. L.

    2016-03-01

    Imaging applications increasingly require light sources with high spectral density (power over spectral bandwidth. This has led in many cases to the replacement of conventional thermal light sources with bright light-emitting diodes (LEDs), lasers and superluminescent diodes. Although lasers and superluminescent diodes appear to be ideal light sources due to their narrow bandwidth and power, however, in the case of full-field imaging, their spatial coherence leads to coherent artefacts, such as speckle, that corrupt the image. LEDs, in contrast, have lower spatial coherence and thus seem the natural choice, but they have low spectral density. Random Lasers are an unconventional type of laser that can be engineered to provide low spatial coherence with high spectral density. These characteristics makes them potential sources for biological imaging applications where specific absorption and reflection are the characteristics required for state of the art imaging. In this work, a Random Laser (RL) is used to demonstrate speckle-free full-field imaging for polarization-dependent imaging in an epi-illumination configuration. We compare LED and RL illumination analysing the resulting images demonstrating that the RL illumination produces an imaging system with higher performance (image quality and spectral density) than that provided by LEDs.

  8. Skin image illumination modeling and chromophore identification for melanoma diagnosis

    Science.gov (United States)

    Liu, Zhao; Zerubia, Josiane

    2015-05-01

    The presence of illumination variation in dermatological images has a negative impact on the automatic detection and analysis of cutaneous lesions. This paper proposes a new illumination modeling and chromophore identification method to correct lighting variation in skin lesion images, as well as to extract melanin and hemoglobin concentrations of human skin, based on an adaptive bilateral decomposition and a weighted polynomial curve fitting, with the knowledge of a multi-layered skin model. Different from state-of-the-art approaches based on the Lambert law, the proposed method, considering both specular reflection and diffuse reflection of the skin, enables us to address highlight and strong shading effects usually existing in skin color images captured in an uncontrolled environment. The derived melanin and hemoglobin indices, directly relating to the pathological tissue conditions, tend to be less influenced by external imaging factors and are more efficient in describing pigmentation distributions. Experiments show that the proposed method gave better visual results and superior lesion segmentation, when compared to two other illumination correction algorithms, both designed specifically for dermatological images. For computer-aided diagnosis of melanoma, sensitivity achieves 85.52% when using our chromophore descriptors, which is 8~20% higher than those derived from other color descriptors. This demonstrates the benefit of the proposed method for automatic skin disease analysis.

  9. Robust Crop and Weed Segmentation under Uncontrolled Outdoor Illumination

    Directory of Open Access Journals (Sweden)

    Hong Y. Jeon

    2011-06-01

    Full Text Available An image processing algorithm for detecting individual weeds was developed and evaluated. Weed detection processes included were normalized excessive green conversion, statistical threshold value estimation, adaptive image segmentation, median filter, morphological feature calculation and Artificial Neural Network (ANN. The developed algorithm was validated for its ability to identify and detect weeds and crop plants under uncontrolled outdoor illuminations. A machine vision implementing field robot captured field images under outdoor illuminations and the image processing algorithm automatically processed them without manual adjustment. The errors of the algorithm, when processing 666 field images, ranged from 2.1 to 2.9%. The ANN correctly detected 72.6% of crop plants from the identified plants, and considered the rest as weeds. However, the ANN identification rates for crop plants were improved up to 95.1% by addressing the error sources in the algorithm. The developed weed detection and image processing algorithm provides a novel method to identify plants against soil background under the uncontrolled outdoor illuminations, and to differentiate weeds from crop plants. Thus, the proposed new machine vision and processing algorithm may be useful for outdoor applications including plant specific direct applications (PSDA.

  10. Standards for illumination of digital prints and photographs

    International Nuclear Information System (INIS)

    Green, Phil

    2010-01-01

    Standards for illuminating digital prints and photographs have a number of quite different applications. In the graphic arts industry, the main applications are defined as appraisal and critical comparison, for which 500lux and 2000lux are specified in ISO 3664. In the museum world much lower levels of illumination are imposed when artefacts are considered to be prone to damage from such exposure. For display and storage of photographic prints, BS 5454:2000 is applicable and specifies maximum levels of 50 lux and 200 lux respectively. While these standards provide recommendations for exposure to radiant energy with the goal of limiting damage to materials and maximising visual discrimination, there is a need for more data on the radiative damage spectrum for the materials used in digital prints and photographs and other artefacts, and on the viewing conditions which can maximise visual performance for specific tasks. It is recommended that radiative exposure is measured in watts per square metre instead of lux to give a better indication of the propensity for radiative damage of a given illumination source.

  11. Illumination Invariant Change Detection (iicd): from Earth to Mars

    Science.gov (United States)

    Wan, X.; Liu, J.; Qin, M.; Li, S. Y.

    2018-04-01

    Multi-temporal Earth Observation and Mars orbital imagery data with frequent repeat coverage provide great capability for planetary surface change detection. When comparing two images taken at different times of day or in different seasons for change detection, the variation of topographic shades and shadows caused by the change of sunlight angle can be so significant that it overwhelms the real object and environmental changes, making automatic detection unreliable. An effective change detection algorithm therefore has to be robust to the illumination variation. This paper presents our research on developing and testing an Illumination Invariant Change Detection (IICD) method based on the robustness of phase correlation (PC) to the variation of solar illumination for image matching. The IICD is based on two key functions: i) initial change detection based on a saliency map derived from pixel-wise dense PC matching and ii) change quantization which combines change type identification, motion estimation and precise appearance change identification. Experiment using multi-temporal Landsat 7 ETM+ satellite images, Rapid eye satellite images and Mars HiRiSE images demonstrate that our frequency based image matching method can reach sub-pixel accuracy and thus the proposed IICD method can effectively detect and precisely segment large scale change such as landslide as well as small object change such as Mars rover, under daily and seasonal sunlight changes.

  12. Light pollution: the possible consequences of excessive illumination on retina.

    Science.gov (United States)

    Contín, M A; Benedetto, M M; Quinteros-Quintana, M L; Guido, M E

    2016-02-01

    Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution.

  13. Screen Space Ambient Occlusion Based Multiple Importance Sampling for Real-Time Rendering

    Science.gov (United States)

    Zerari, Abd El Mouméne; Babahenini, Mohamed Chaouki

    2018-03-01

    We propose a new approximation technique for accelerating the Global Illumination algorithm for real-time rendering. The proposed approach is based on the Screen-Space Ambient Occlusion (SSAO) method, which approximates the global illumination for large, fully dynamic scenes at interactive frame rates. Current algorithms that are based on the SSAO method suffer from difficulties due to the large number of samples that are required. In this paper, we propose an improvement to the SSAO technique by integrating it with a Multiple Importance Sampling technique that combines a stratified sampling method with an importance sampling method, with the objective of reducing the number of samples. Experimental evaluation demonstrates that our technique can produce high-quality images in real time and is significantly faster than traditional techniques.

  14. Alternative method for determining the constant offset in lidar signal

    Science.gov (United States)

    Vladimir A. Kovalev; Cyle Wold; Alexander Petkov; Wei Min Hao

    2009-01-01

    We present an alternative method for determining the total offset in lidar signal created by a daytime background-illumination component and electrical or digital offset. Unlike existing techniques, here the signal square-range-correction procedure is initially performed using the total signal recorded by lidar, without subtraction of the offset component. While...

  15. Tipologia para a contabilidade ambiental

    Directory of Open Access Journals (Sweden)

    Nazlhe Faride Chein Schekaiban

    2007-06-01

    Full Text Available Este artigo revê a visão, as propostas e o desenvolvimento da contabilidade ambiental, refletindo sobre suas implicações, com a finalidade de descobrir e encontrar sua importância e situação. Para se chegar a esse resultado foi preciso realizar uma revisão epistemológica moldada e processo reflexivo de sustentabilidade e da aproximação ao usuário, da percepção da realidade contábil no México e da gerência interna das organizações. As conclusões mostram a contabilidade ambiental no México fora da re-alidade operativa do modelo contábil regional, aumentando a importância de se criar uma cultura capaz de examinar o controle da missão deste tipo de contabilidade.

  16. Responsabilidades municipales en materia ambiental

    Directory of Open Access Journals (Sweden)

    Ignacio Pichardo Pagaza

    2009-01-01

    Este trabajo reflexiona en torno a las responsabilidades que la Constitución política impone de manera exclusiva a los municipios y que por su naturaleza tienen efectos directos en el medio ambiente. Se alude aquí a los servicios de agua po ta ble, drenaje, saneamiento, tratamiento de aguas residuales, disposición de residuos sólidos, rastros, panteones y mercados. Ahora son los desafíos ambientales de la autoridad municipal, por lo que deben ser también sus prioridades. Si esos servicios no se atienden oportuna y técnicamente la población sufrirá, se deteriorará gravemente el medio ambiente y disminuirá la calidad de la vida de la comunidad.

  17. The Potential for Ambient Plasma Wave Propulsion

    Science.gov (United States)

    Gilland, James H.; Williams, George J.

    2016-01-01

    A truly robust space exploration program will need to make use of in-situ resources as much as possible to make the endeavor affordable. Most space propulsion concepts are saddled with one fundamental burden; the propellant needed to produce momentum. The most advanced propulsion systems currently in use utilize electric and/or magnetic fields to accelerate ionized propellant. However, significant planetary exploration missions in the coming decades, such as the now canceled Jupiter Icy Moons Orbiter, are restricted by propellant mass and propulsion system lifetimes, using even the most optimistic projections of performance. These electric propulsion vehicles are inherently limited in flexibility at their final destination, due to propulsion system wear, propellant requirements, and the relatively low acceleration of the vehicle. A few concepts are able to utilize the environment around them to produce thrust: Solar or magnetic sails and, with certain restrictions, electrodynamic tethers. These concepts focus primarily on using the solar wind or ambient magnetic fields to generate thrust. Technically immature, quasi-propellantless alternatives lack either the sensitivity or the power to provide significant maneuvering. An additional resource to be considered is the ambient plasma and magnetic fields in solar and planetary magnetospheres. These environments, such as those around the Sun or Jupiter, have been shown to host a variety of plasma waves. Plasma wave propulsion takes advantage of an observed astrophysical and terrestrial phenomenon: Alfven waves. These are waves that propagate in the plasma and magnetic fields around and between planets and stars. The generation of Alfven waves in ambient magnetic and plasma fields to generate thrust is proposed as a truly propellantless propulsion system which may enable an entirely new matrix of exploration missions. Alfven waves are well known, transverse electromagnetic waves that propagate in magnetized plasmas at

  18. Ambiente psicologico en las organizaciones

    Directory of Open Access Journals (Sweden)

    Damarcy Cortés Baracaldo

    2002-01-01

    Full Text Available El talento humano en las organizaciones se ha convertido en las ultimas decadas en un recurso que se administra de acuerdo al estilo de liderazgo del jefe, lo que implica una marcada relación hacia la tarea, hacia las relaciones con el personal o una combinación de estas dos, que desencadenan en un ambiente psicológico exclusive en cada organización.

  19. Ambient Volatility of Triethyl Phosphate

    Science.gov (United States)

    2017-08-01

    of materials is predictable using Raoult’s law. This report details the measurement of the effect of water vapor partial pressure on the volatility...empirical correlation taking into account nonideal behavior was developed to enable estimation of TEPO volatility at any combination of ambient...of the second component is expected to be one-half as much as in the absence of water vapor. Similarly, the measured volatility of the second

  20. Haciendas Locales y Medio Ambiente

    OpenAIRE

    Rozas Valdés, José Andrés

    1997-01-01

    Junto a los medios puramente administrativos orientados a la protección del medio ambiente, cada día adquieren mayor protagonismo los que pueden adoptarse desde el ámbito del derecho financiero, del ingreso y gasto públicos. El trabajo se ha estructurado en cuatro apartados: aguas, residuos sólidos, polución atmosférica y contaminación acústica.

  1. Alternative detente

    International Nuclear Information System (INIS)

    Soper, K.; Ryle, M.

    1988-01-01

    The influence of the Chernobyl accident on the disarmament and anti-nuclear movements is discussed. The accident directed attention towards the areas in common rather than the areas of disagreement. It also demonstrated the environmental impact of radioactivity, strengthening the ecological case of the anti-nuclear movement. The issues are discussed for the Western and Eastern bloc countries and the relationship between the two. Sections focus on the Eco-protest, Green politics and economics and on the politics of minority protest and the Green alternative. (U.K.)

  2. Spectral-Efficiency - Illumination Pareto Front for Energy Harvesting Enabled VLC System

    KAUST Repository

    Abdelhady, Amr Mohamed Abdelaziz; Amin, Osama; Chaaban, Anas; Alouini, Mohamed-Slim

    2017-01-01

    . The adopted optical system provides users with illumination and data communication services. The outdoor optical design objective is to maximize the illumination, while the communication design objective is to maximize the spectral efficiency (SE). The design

  3. Influence of illumination on the output characteristics in pentacene thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yow-Jon, E-mail: rzr2390@yahoo.com.tw; Huang, Bo-Chieh

    2013-10-01

    The influence of illumination on the output characteristics of pentacene-based organic thin film transistors (OTFTs) was researched in this study. It is shown that light illumination may lead to an increase in the drain current, shifting the threshold voltage towards positive gate–source voltages. This is because of the light-induced acceptor activation, which is a new concept for illumination-dependent output characteristics of OTFTs. However, the field-effect mobility is insensitive to light illumination. It is found that electron trapping is responsible for the experimentally observed illumination-dependent output behavior of charge transport in OTFTs. - Highlights: • Light illumination may lead to an increase in the drain current. • This is because of the light-induced acceptor activation. • The field-effect mobility is insensitive to light illumination. • Electron trapping is responsible for the illumination-dependent output behavior.

  4. Investigating the performance of reconstruction methods used in structured illumination microscopy as a function of the illumination pattern's modulation frequency

    Science.gov (United States)

    Shabani, H.; Sánchez-Ortiga, E.; Preza, C.

    2016-03-01

    Surpassing the resolution of optical microscopy defined by the Abbe diffraction limit, while simultaneously achieving optical sectioning, is a challenging problem particularly for live cell imaging of thick samples. Among a few developing techniques, structured illumination microscopy (SIM) addresses this challenge by imposing higher frequency information into the observable frequency band confined by the optical transfer function (OTF) of a conventional microscope either doubling the spatial resolution or filling the missing cone based on the spatial frequency of the pattern when the patterned illumination is two-dimensional. Standard reconstruction methods for SIM decompose the low and high frequency components from the recorded low-resolution images and then combine them to reach a high-resolution image. In contrast, model-based approaches rely on iterative optimization approaches to minimize the error between estimated and forward images. In this paper, we study the performance of both groups of methods by simulating fluorescence microscopy images from different type of objects (ranging from simulated two-point sources to extended objects). These simulations are used to investigate the methods' effectiveness on restoring objects with various types of power spectrum when modulation frequency of the patterned illumination is changing from zero to the incoherent cut-off frequency of the imaging system. Our results show that increasing the amount of imposed information by using a higher modulation frequency of the illumination pattern does not always yield a better restoration performance, which was found to be depended on the underlying object. Results from model-based restoration show performance improvement, quantified by an up to 62% drop in the mean square error compared to standard reconstruction, with increasing modulation frequency. However, we found cases for which results obtained with standard reconstruction methods do not always follow the same trend.

  5. Alternative crops

    International Nuclear Information System (INIS)

    Andreasen, L.M.; Boon, A.D.

    1992-01-01

    Surplus cereal production in the EEC and decreasing product prices, mainly for cereals, has prompted considerable interest for new earnings in arable farming. The objective was to examine whether suggested new crops (fibre, oil, medicinal and alternative grains crops) could be considered as real alternatives. Whether a specific crop can compete economically with cereals and whether there is a market demand for the crop is analyzed. The described possibilities will result in ca. 50,000 hectares of new crops. It is expected that they would not immediately provide increased earnings, but in the long run expected price developments are more positive than for cereals. The area for new crops will not solve the current surplus cereal problem as the area used for new crops is only 3% of that used for cereals. Preconditions for many new crops is further research activities and development work as well as the establishment of processing units and organizational initiatives. Presumably, it is stated, there will then be a basis for a profitable production of new crops for some farmers. (AB) (47 refs.)

  6. Dim nighttime illumination interacts with parametric effects of bright light to increase the stability of circadian rhythm bifurcation in hamsters.

    Science.gov (United States)

    Evans, Jennifer A; Elliott, Jeffrey A; Gorman, Michael R

    2011-07-01

    The endogenous circadian pacemaker of mammals is synchronized to the environmental day by the ambient cycle of relative light and dark. The present studies assessed the actions of light in a novel circadian entrainment paradigm where activity rhythms are bifurcated following exposure to a 24-h light:dark:light:dark (LDLD) cycle. Bifurcated entrainment under LDLD reflects the temporal dissociation of component oscillators that comprise the circadian system and is facilitated when daily scotophases are dimly lit rather than completely dark. Although bifurcation can be stably maintained in LDLD, it is quickly reversed under constant conditions. Here the authors examine whether dim scotophase illumination acts to maintain bifurcated entrainment under LDLD through potential interactions with the parametric actions of bright light during the two daily photophases. In three experiments, wheel-running rhythms of Syrian hamsters were bifurcated under LDLD with dimly lit scotophases, and after several weeks, dim scotophase illumination was either retained or extinguished. Additionally, "full" and "skeleton" photophases were employed under LDLD cycles with dimly lit or completely dark scotophases to distinguish parametric from nonparametric effects of bright light. Rhythm bifurcation was more stable in full versus skeleton LDLD cycles. Dim light facilitated the maintenance of bifurcated entrainment under full LDLD cycles but did not prevent the loss of rhythm bifurcation in skeleton LDLD cycles. These studies indicate that parametric actions of bright light maintain the bifurcated entrainment state; that dim scotophase illumination increases the stability of the bifurcated state; and that dim light interacts with the parametric effects of bright light to increase the stability of rhythm bifurcation under full LDLD cycles. A further understanding of the novel actions of dim light may lead to new strategies for understanding, preventing, and treating chronobiological

  7. Illumination non-uniformity of spirally wobbling beam in heavy ion fusion

    International Nuclear Information System (INIS)

    Suzuki, T.; Noguchi, K.; Kurosaki, T.; Barada, D.; Kawata, S.; Ma, Y. Y.; Ogoyski, A.I.

    2016-01-01

    In inertial confinement fusion, the driver beam illumination non-uniformity leads a degradation of fusion energy output. The illumination non-uniformity allowed is less than a few percent in inertial fusion target implosion. Heavy ion beam (HIB) accelerator provides a capability to oscillate a beam axis with a high frequency. The wobbling beams may provide a new method to reduce or smooth the beam illumination non-uniformity. In this paper the HIBs wobbling illumination scheme was optimized. (paper)

  8. A Curious Problem with Using the Colour Checker Dataset for Illuminant Estimation

    OpenAIRE

    Finlayson, Graham; Hemrit, Ghalia; Gijsenij, Arjan; Gehler, Peter

    2017-01-01

    In illuminant estimation, we attempt to estimate the RGB of the light. We then use this estimate on an image to correct for the light's colour bias. Illuminant estimation is an essential component of all camera reproduction pipelines. How well an illuminant estimation algorithm works is determined by how well it predicts the ground truth illuminant colour. Typically, the ground truth is the RGB of a white surface placed in a scene. Over a large set of images an estimation error is calculated ...

  9. Model-Based Illumination Correction for Face Images in Uncontrolled Scenarios

    NARCIS (Netherlands)

    Boom, B.J.; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.

    2009-01-01

    Face Recognition under uncontrolled illumination conditions is partly an unsolved problem. Several illumination correction methods have been proposed, but these are usually tested on illumination conditions created in a laboratory. Our focus is more on uncontrolled conditions. We use the Phong model

  10. Macular photostress and visual experience between microscope and intracameral illumination during cataract surgery.

    Science.gov (United States)

    Seo, Hyejin; Nam, Dong Heun; Lee, Jong Yeon; Park, Su Jin; Kim, Yu Jeong; Kim, Seong-Woo; Chung, Tae-Young; Inoue, Makoto; Kim, Terry

    2018-02-01

    To evaluate macular photostress and visual experience between coaxial microscope illumination versus oblique intracameral illumination during cataract surgery. Gachon University Gil Hospital, Incheon, South Korea. Prospective case series. Consecutive patients who had cataract surgery using microscope illumination and intracameral illumination were included. The patients were asked to complete a questionnaire (seeing strong lights, feeling photophobia, feeling startled (fright) when seeing lights, seeing any colors, seeing any instruments or surgical procedures, and estimating intraoperative visual function) designed to describe their cataract surgery experience. The images projected on the retina of the model eye (rear view) with artificial opaque fragments in the anterior chamber during simulating cataract surgery were compared between the 2 illumination types. Sixty patients completed the questionnaire. Scores for strong lights, photophobia, fright, and color perception were significantly higher with microscope illumination than with intracameral illumination (all P microscope illumination (13 [21.7%]). In the rear-view images created in a model eye, only the bright microscope light in the center was seen without any lens image in the microscope illumination. However, in the intracameral illumination, the less bright light from the light pipe in the periphery and the lens fragments were seen more clearly. In a view of the patients' visual experience, oblique intracameral illumination caused less subjective photostress and was preferred over coaxial microscope illumination. Objective findings from the model-eye experiment correlated to the result of visual experience. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. Comparative phototoxicity of nanoparticulate and bulk ZnO to a free-living nematode Caenorhabditis elegans: The importance of illumination mode and primary particle size

    International Nuclear Information System (INIS)

    Ma, H.; Kabengi, N.J.; Bertsch, P.M.; Unrine, J.M.; Glenn, T.C.; Williams, P.L.

    2011-01-01

    The present study evaluated phototoxicity of nanoparticulate ZnO and bulk-ZnO under natural sunlight (NSL) versus ambient artificial laboratory light (AALL) illumination to a free-living nematode Caenorhabditis elegans. Phototoxicity of nano-ZnO and bulk-ZnO was largely dependent on illumination method as 2-h exposure under NSL caused significantly greater mortality in C. elegans than under AALL. This phototoxicity was closely related to photocatalytic reactive oxygen species (ROS) generation by the ZnO particles as indicated by concomitant methylene blue photodegradation. Both materials caused mortality in C. elegans under AALL during 24-h exposure although neither degraded methylene blue, suggesting mechanisms of toxicity other than photocatalytic ROS generation were involved. Particle dissolution of ZnO did not appear to play an important role in the toxicity observed in this study. Nano-ZnO showed greater phototoxicity than bulk-ZnO despite their similar size of aggregates, suggesting primary particle size is more important than aggregate size in determining phototoxicity. - Highlights: → Phototoxicity of nano- or bulk-ZnO was enhanced by natural sunlight illumination. → This phototoxicity was well-correlated to photocatalytic ROS generation. → Toxicity of ZnO particles not related to photocatalytic ROS generation was also observed. → Nano-ZnO showed greater phototoxicity than bulk-ZnO due to its greater total surface area per unit mass. → Primary particle size appeared to be more important than aggregate size in determining phototoxicity. - Phototoxicity of nanoparticulate and bulk ZnO was greatly enhanced by natural sunlight illumination compared to artificial laboratory light illumination.

  12. Comparative phototoxicity of nanoparticulate and bulk ZnO to a free-living nematode Caenorhabditis elegans: The importance of illumination mode and primary particle size

    Energy Technology Data Exchange (ETDEWEB)

    Ma, H., E-mail: mah77@uga.edu [Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602 (United States); Kabengi, N.J.; Bertsch, P.M.; Unrine, J.M. [Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546 (United States); Glenn, T.C.; Williams, P.L. [Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA 30602 (United States)

    2011-06-15

    The present study evaluated phototoxicity of nanoparticulate ZnO and bulk-ZnO under natural sunlight (NSL) versus ambient artificial laboratory light (AALL) illumination to a free-living nematode Caenorhabditis elegans. Phototoxicity of nano-ZnO and bulk-ZnO was largely dependent on illumination method as 2-h exposure under NSL caused significantly greater mortality in C. elegans than under AALL. This phototoxicity was closely related to photocatalytic reactive oxygen species (ROS) generation by the ZnO particles as indicated by concomitant methylene blue photodegradation. Both materials caused mortality in C. elegans under AALL during 24-h exposure although neither degraded methylene blue, suggesting mechanisms of toxicity other than photocatalytic ROS generation were involved. Particle dissolution of ZnO did not appear to play an important role in the toxicity observed in this study. Nano-ZnO showed greater phototoxicity than bulk-ZnO despite their similar size of aggregates, suggesting primary particle size is more important than aggregate size in determining phototoxicity. - Highlights: > Phototoxicity of nano- or bulk-ZnO was enhanced by natural sunlight illumination. > This phototoxicity was well-correlated to photocatalytic ROS generation. > Toxicity of ZnO particles not related to photocatalytic ROS generation was also observed. > Nano-ZnO showed greater phototoxicity than bulk-ZnO due to its greater total surface area per unit mass. > Primary particle size appeared to be more important than aggregate size in determining phototoxicity. - Phototoxicity of nanoparticulate and bulk ZnO was greatly enhanced by natural sunlight illumination compared to artificial laboratory light illumination.

  13. Energy alternatives

    International Nuclear Information System (INIS)

    1981-01-01

    English. A special committe of the Canadian House of Commons was established on 23 May 1980 to investigate the use of alternative energy sources such as 'gasohol', liquified coal, solar energy, methanol, wind and tidal power, biomass, and propane. In its final report, the committee envisions an energy system for Canada based on hydrogen and electricity, using solar and geothermal energy for low-grade heat. The committe was not able to say which method of generating electricty would dominate in the next century, although it recommends that fossil fuels should not be used. The fission process is not specifically discussed, but the outlook for fusion was investigated, and continued governmental support of fusion research is recommended. The report proposes some improvements in governmental energy organizations and programs

  14. Effect of NICU Illumination upon Behaviors in Preterm Infants

    OpenAIRE

    白岩, 義夫; 河合, 優年; 犬飼, 和久; 鬼頭, 秀行; 小川, 次郎

    1993-01-01

    The purpose of this study was to determine the effect of illumination in a Neonatal Intensive Care Unit (NICU) on behaviors and behavioral states in preterm infants. The Ss were individually observed twice in a day for a period of one hour by a video recording system. The results showed that rates of awakening and eye-opening during the awake state were higher, and their eyes were opened more widely under the dark condition than the bright. The bright condition increased the rate of Behavior ...

  15. Light induced modulation instability of surfaces under intense illumination

    KAUST Repository

    Burlakov, V. M.

    2013-12-17

    We show that a flat surface of a polymer in rubber state illuminated with intense electromagnetic radiation is unstable with respect to periodic modulation. Initial periodic perturbation is amplified due to periodic thermal expansion of the material heated by radiation. Periodic heating is due to focusing-defocusing effects caused by the initial surface modulation. The surface modulation has a period longer than the excitation wavelength and does not require coherent light source. Therefore, it is not related to the well-known laser induced periodic structures on polymer surfaces but may contribute to their formation and to other phenomena of light-matter interaction.

  16. Restoration of uneven illumination in light sheet microscopy images.

    Science.gov (United States)

    Uddin, Mohammad Shorif; Lee, Hwee Kuan; Preibisch, Stephan; Tomancak, Pavel

    2011-08-01

    Light microscopy images suffer from poor contrast due to light absorption and scattering by the media. The resulting decay in contrast varies exponentially across the image along the incident light path. Classical space invariant deconvolution approaches, while very effective in deblurring, are not designed for the restoration of uneven illumination in microscopy images. In this article, we present a modified radiative transfer theory approach to solve the contrast degradation problem of light sheet microscopy (LSM) images. We confirmed the effectiveness of our approach through simulation as well as real LSM images.

  17. Redundant information from thermal illumination: quantum Darwinism in scattered photons

    Energy Technology Data Exchange (ETDEWEB)

    Jess Riedel, C; Zurek, Wojciech H, E-mail: criedel@physics.ucsb.edu [Theory Division, LANL, Los Alamos, NM 87545 (United States)

    2011-07-15

    We study quantum Darwinism, the redundant recording of information about the preferred states of a decohering system by its environment, for an object illuminated by a blackbody. We calculate the quantum mutual information between the object and its photon environment for blackbodies that cover an arbitrary section of the sky. In particular, we demonstrate that more extended sources have a reduced ability to create redundant information about the system, in agreement with previous evidence that initial mixedness of an environment slows-but does not stop-the production of records. We also show that the qualitative results are robust for more general initial states of the system.

  18. Redundant information from thermal illumination: quantum Darwinism in scattered photons

    Science.gov (United States)

    Jess Riedel, C.; Zurek, Wojciech H.

    2011-07-01

    We study quantum Darwinism, the redundant recording of information about the preferred states of a decohering system by its environment, for an object illuminated by a blackbody. We calculate the quantum mutual information between the object and its photon environment for blackbodies that cover an arbitrary section of the sky. In particular, we demonstrate that more extended sources have a reduced ability to create redundant information about the system, in agreement with previous evidence that initial mixedness of an environment slows—but does not stop—the production of records. We also show that the qualitative results are robust for more general initial states of the system.

  19. GPU-Based Techniques for Global Illumination Effects

    CERN Document Server

    Szirmay-Kalos, László; Sbert, Mateu

    2008-01-01

    This book presents techniques to render photo-realistic images by programming the Graphics Processing Unit (GPU). We discuss effects such as mirror reflections, refractions, caustics, diffuse or glossy indirect illumination, radiosity, single or multiple scattering in participating media, tone reproduction, glow, and depth of field. This book targets game developers, graphics programmers, and also students with some basic understanding of computer graphics algorithms, rendering APIs like Direct3D or OpenGL, and shader programming. In order to make this book self-contained, the most important c

  20. BCB Bonding Technology of Back-Side Illuminated COMS Device

    Science.gov (United States)

    Wu, Y.; Jiang, G. Q.; Jia, S. X.; Shi, Y. M.

    2018-03-01

    Back-side illuminated CMOS(BSI) sensor is a key device in spaceborne hyperspectral imaging technology. Compared with traditional devices, the path of incident light is simplified and the spectral response is planarized by BSI sensors, which meets the requirements of quantitative hyperspectral imaging applications. Wafer bonding is the basic technology and key process of the fabrication of BSI sensors. 6 inch bonding of CMOS wafer and glass wafer was fabricated based on the low bonding temperature and high stability of BCB. The influence of different thickness of BCB on bonding strength was studied. Wafer bonding with high strength, high stability and no bubbles was fabricated by changing bonding conditions.

  1. Cartesian oval representation of freeform optics in illumination systems.

    Science.gov (United States)

    Michaelis, D; Schreiber, P; Bräuer, A

    2011-03-15

    The geometrical method for constructing optical surfaces for illumination purpose developed by Oliker and co-workers [Trends in Nonlinear Analysis (Springer, 2003)] is generalized in order to obtain freeform designs in arbitrary optical systems. The freeform is created by a set of primitive surface elements, which are generalized Cartesian ovals adapted to the given optical system. Those primitives are determined by Hamiltonian theory of ray optics. The potential of this approach is demonstrated by some examples, e.g., freeform lenses with collimating front elements.

  2. Design of High Efficiency Illumination for LED Lighting

    Directory of Open Access Journals (Sweden)

    Yong-Nong Chang

    2013-01-01

    Full Text Available A high efficiency illumination for LED street lighting is proposed. For energy saving, this paper uses Class-E resonant inverter as main electric circuit to improve efficiency. In addition, single dimming control has the best efficiency, simplest control scheme and lowest circuit cost among other types of dimming techniques. Multiple serial-connected transformers used to drive the LED strings as they can provide galvanic isolation and have the advantage of good current distribution against device difference. Finally, a prototype circuit for driving 112 W LEDs in total was built and tested to verify the theoretical analysis.

  3. Maquinas virtuais em ambientes seguros

    OpenAIRE

    Arthur Bispo de Castro

    2006-01-01

    Resumo: Desde o início da computação a idéia de máquinas virtuais vem sendo aplicada para estender o multiprocessamento, multi-programação e multi-acesso, tornando os sistemas multi-ambiente. O contínuo aumento no poder de processamento dos computadores fez com que máquinas muito rápidas estivessem ao alcance de qualquer usuário, surgindo PCs com processamento, espaço em disco e memória suficiente para comportar mais de um sistema compartilhando o mesmo hardware. Basicamente, o objetivo das m...

  4. educación ambiental

    Directory of Open Access Journals (Sweden)

    Fernando Ojeda Barceló

    2008-01-01

    Full Text Available Las Tecnologías de la Información y Comunicación (TICs pueden constituir una herramienta de primer orden para la Educación Ambiental para la Sostenibilidad (EApS, pero todavía existe cierta reticencia por parte de educadores ambientales a hacer un uso de ellas de forma habitual. El objetivo fundamental de este trabajo es ofrecer una revisión del estado de la cuestión tanto a nivel nacional como internacional e intentar hacer una propuesta didáctica de trabajo colaborativo a través de Internet para estudiantes de secundaria.

  5. Pediatria ambiental: um tema emergente

    Directory of Open Access Journals (Sweden)

    Patricia M. Valenzuela

    2011-04-01

    Full Text Available OBJETIVO: Revisar os artigos mais relevantes sobre a pediatria ambiental, seus efeitos potenciais para a saúde e, especialmente, seus avanços na prevenção. FONTES DOS DADOS: Foi realizada uma pesquisa utilizando as bases de dados MEDLINE/PubMed e SciELO. Foram revisados artigos de 1990 a 2010, além de capítulos de livros relacionados à pediatria ambiental. SÍNTESE DOS DADOS: Há uma variedade significativa de fatores que tornam as crianças altamente vulneráveis à exposição a riscos ambientais, associados principalmente ao consumo comparativamente maior de água, comida e ar por parte da criança, em relação ao seu peso corporal. De acordo com a Organização Mundial de Saúde, mais de 3 milhões de crianças menores de 5 anos morrem devido a doenças relacionadas ao meio ambiente. Aproximadamente 30-40% das doenças pediátricas estão relacionadas a fatores ambientais. As crianças estão constantemente expostas a vários riscos ambientais para a saúde, dentre os quais se destacam: água contaminada, falta de condições adequadas de saneamento, poluição do ar, vetores de doenças, perigos químicos, injúrias e acidentes. CONCLUSÕES: Atualmente, os pediatras são desafiados a tratar das necessidades de saúde ligadas à pediatria ambiental. A história pediátrica deve ser mais abrangente, acrescentando-se questões pontuais que ajudem a identificar potenciais riscos ambientais. A conscientização e o entendimento sobre os efeitos nocivos das várias condições ambientais e o conhecimento sobre as medidas de prevenção relacionadas resultarão em intervenções oportunas e adequadas que melhorarão a saúde e o desenvolvimento das nossas crianças.

  6. Performance of Series Connected GaAs Photovoltaic Converters under Multimode Optical Fiber Illumination

    Directory of Open Access Journals (Sweden)

    Tiqiang Shan

    2014-01-01

    Full Text Available In many military and industrial applications, GaAs photovoltaic (PV converters are connected in series in order to generate the required voltage compatible with most common electronics. Multimode optical fibers are usually used to carry high-intensity laser and illuminate the series connected GaAs PV converters in real time. However, multimode optical fiber illumination has a speckled intensity pattern. The series connected PV array is extremely sensitive to nonuniform illumination; its performance is limited severely by the converter that is illuminated the least. This paper quantifies the effects of multimode optical fiber illumination on the performance of series connected GaAs PV converters, analyzes the loss mechanisms due to speckles, and discusses the maximum illumination efficiency. In order to describe the illumination dependent behavior detailedly, modeling of the series connected PV array is accomplished based on the equivalent circuit for PV cells. Finally, a series of experiments are carried out to demonstrate the theory analysis.

  7. Exomoon habitability constrained by illumination and tidal heating.

    Science.gov (United States)

    Heller, René; Barnes, Rory

    2013-01-01

    The detection of moons orbiting extrasolar planets ("exomoons") has now become feasible. Once they are discovered in the circumstellar habitable zone, questions about their habitability will emerge. Exomoons are likely to be tidally locked to their planet and hence experience days much shorter than their orbital period around the star and have seasons, all of which works in favor of habitability. These satellites can receive more illumination per area than their host planets, as the planet reflects stellar light and emits thermal photons. On the contrary, eclipses can significantly alter local climates on exomoons by reducing stellar illumination. In addition to radiative heating, tidal heating can be very large on exomoons, possibly even large enough for sterilization. We identify combinations of physical and orbital parameters for which radiative and tidal heating are strong enough to trigger a runaway greenhouse. By analogy with the circumstellar habitable zone, these constraints define a circumplanetary "habitable edge." We apply our model to hypothetical moons around the recently discovered exoplanet Kepler-22b and the giant planet candidate KOI211.01 and describe, for the first time, the orbits of habitable exomoons. If either planet hosted a satellite at a distance greater than 10 planetary radii, then this could indicate the presence of a habitable moon.

  8. Bifurcations in two-image photometric stereo for orthogonal illuminations

    Science.gov (United States)

    Kozera, R.; Prokopenya, A.; Noakes, L.; Śluzek, A.

    2017-07-01

    This paper discusses the ambiguous shape recovery in two-image photometric stereo for a Lambertian surface. The current uniqueness analysis refers to linearly independent light-source directions p = (0, 0, -1) and q arbitrary. For this case necessary and sufficient condition determining ambiguous reconstruction is governed by a second-order linear partial differential equation with constant coefficients. In contrast, a general position of both non-colinear illumination directions p and q leads to a highly non-linear PDE which raises a number of technical difficulties. As recently shown, the latter can also be handled for another family of orthogonal illuminations parallel to the OXZ-plane. For the special case of p = (0, 0, -1) a potential ambiguity stems also from the possible bifurcations of sub-local solutions glued together along a curve defined by an algebraic equation in terms of the data. This paper discusses the occurrence of similar bifurcations for such configurations of orthogonal light-source directions. The discussion to follow is supplemented with examples based on continuous reflectance map model and generated synthetic images.

  9. Microplasma light tiles: thin sheet lamps for general illumination

    Energy Technology Data Exchange (ETDEWEB)

    Eden, J G; Park, S-J [Laboratory for Optical Physics and Engineering, Department of Electrical and Computer Engineering, University of Illinois, Urbana, IL 61801 (United States); Herring, C M; Bulson, J M [Eden Park Illumination, 903 North Country Fair Drive, Champaign, IL 61821 (United States)

    2011-06-08

    Flat, thin and lightweight lamps providing spatially uniform and dimmable illumination from active areas as large as 400 cm{sup 2} are being developed for general illumination and specialty applications. Comprising an array of low-temperature, nonequilibrium microplasmas driven by a dielectric barrier structure and operating at pressures of typically 400-700 Torr, these lamps have a packaged thickness <4 mm and yet produce luminance values beyond 26 000 cd m{sup -2} with a luminous efficacy approaching 30 lm W{sup -1}. Third generation lamps, presently in limited production, offer a correlated colour temperature in the 3000-4100 K interval and a colour rendering index of 80. Current lamps employ Xe{sub 2} ({lambda} {approx} 172 nm) as the primary emitter photoexciting a mixture of phosphors, and the pressure dependence of the wavelength-integrated fluorescence from the electronically excited dimer has been investigated with a vacuum ultraviolet spectrometer. In contrast to other promising lighting technologies, the decline in luminous efficacy of microplasma lamps with increasing power delivered to the lamp is small. For a 6 x 6 inch{sup 2} ({approx}225 cm{sup 2}) lamp, efficacy falls <16% when the radiant output (luminance) is raised from 2000 cd m{sup -2} to > 10 000 cd m{sup -2}.

  10. Holographically generated structured illumination for cell stimulation in optogenetics

    Science.gov (United States)

    Schmieder, Felix; Büttner, Lars; Czarske, Jürgen; Torres, Maria Leilani; Heisterkamp, Alexander; Klapper, Simon; Busskamp, Volker

    2017-06-01

    In Optogenetics, cells, e.g. neurons or cardiac cells, are genetically altered to produce for example the lightsensitive protein Channelrhodopsin-2. Illuminating these cells induces action potentials or contractions and therefore allows to control electrical activity. Thus, light-induced cell stimulation can be used to gain insight to various biological processes. Many optogenetics studies, however, use only full field illumination and thus gain no local information about their specimen. But using modern spatial light modulators (SLM) in conjunction with computer-generated holograms (CGH), cells may be stimulated locally, thus enabling the research of the foundations of cell networks and cell communications. In our contribution, we present a digital holographic system for the patterned, spatially resolved stimulation of cell networks. We employ a fast ferroelectric liquid crystal on silicon SLM to display CGH at up to 1.7 kHz. With an effective working distance of 33 mm, we achieve a focus of 10 μm at a positioning accuracy of the individual foci of about 8 μm. We utilized our setup for the optogenetic stimulation of clusters of cardiac cells derived from induced pluripotent stem cells and were able to observe contractions correlated to both temporal frequency and spatial power distribution of the light incident on the cell clusters.

  11. Modeling illumination performance of plastic optical fiber passive daylighting system

    Energy Technology Data Exchange (ETDEWEB)

    Sulaiman, F; Ahmad, A [Universiti Teknologi MARA, Shah Alam (Malaysia). Faculty of Electrical Engineering; Ahmed, A Z [Universiti Teknologi MARA, Shah Alam (Malaysia). Bureau of Reseaarch and Consultancy

    2006-12-15

    of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings.

  12. Modeling illumination performance of plastic optical fiber passive daylighting system

    International Nuclear Information System (INIS)

    Sulaiman, F.; Ahmad, A.; Ahmed, A.Z.

    2006-01-01

    One of the most direct methods of utilizing solar energy for energy conservation is to bring natural light indoors to light up an area. This paper reports on the investigation of the feasibility to utilize large core optical fibers to convey and distribute solar light passively throughout residential or commercial structures. The focus of this study is on the mathematical modeling of the illumination performance and the light transmission efficiency of solid core end light fiber for optical day lighting systems. The Meatball simulations features the optical fiber transmittance for glass and plastic fibers, illumination performance over lengths of plastic end-lit fiber, spectral transmission, light intensity loss through the large diameter solid core optical fibers as well as the transmission efficiency of the optical fiber itself. It was found that plastic optical fiber has less transmission loss over the distance of the fiber run which clearly shows that the Plastic Optical Fiber should be optimized for emitting visible light. The findings from the analysis on the performance of large diameter optical fibers for day lighting systems seems feasible for energy efficient lighting system in commercial or residential buildings

  13. Sirius-T, a symmetrically illuminated ICF tritium production facility

    International Nuclear Information System (INIS)

    Sviatoslavsky, I.N.; Sawan, M.E.; Moses, G.A.; Kulcinski, G.L.; Engelstad, R.L.; Larsen, E.; Lovell, E.; MacFarlane, J.; Peterson, R.R.; Wittenberg, L.J.

    1989-01-01

    A scoping study of a symmetrically illuminated ICF tritium production facility utilizing a KrF laser is presented. A single shell ICF target is illuminated by 92 beams symmetrically distributed around a spherical cavity filled with xenon gas at 1.0 torr. The driver energy and target gain are taken to be 2 MJ and 50 for the optimistic case and 1 MJ and 100 for the conservative case. Based on a graphite dry wall evaporation rate of 0.1 cm/y for a 100 MJ yield, the authors estimate a cavity radius of 3.5 m for a rep-rate of 10 Hz and 3.0 m for 5 Hz. A spherical structural frame has been scoped out capable of supporting 92 blanket modules, each with a beam port in the center. They have selected liquid lithium in vanadium structure as the primary breeding concept utilizing beryllium as a neutron multiplier. A tritium breeding ratio of 1.83 can be achieved in the 3 m radius cavity which at 10 Hz and an availability of 75% provides an annual tritium surplus of 32.6 kg. Assuming 100% debt financing over a 30 year reactor lifetime, the production cost of T 2 for the 2 MJ driver case is $7,325/g for a 5% interest rate and $12,370/g for a 10% interest rate. 8 refs., 3 figs., 4 tabs

  14. Assessing resolution in live cell structured illumination microscopy

    Science.gov (United States)

    Pospíšil, Jakub; Fliegel, Karel; Klíma, Miloš

    2017-12-01

    Structured Illumination Microscopy (SIM) is a powerful super-resolution technique, which is able to enhance the resolution of optical microscope beyond the Abbe diffraction limit. In the last decade, numerous SIM methods that achieve the resolution of 100 nm in the lateral dimension have been developed. The SIM setups with new high-speed cameras and illumination pattern generators allow rapid acquisition of the live specimen. Therefore, SIM is widely used for investigation of the live structures in molecular and live cell biology. Quantitative evaluation of resolution enhancement in a real sample is essential to describe the efficiency of super-resolution microscopy technique. However, measuring the resolution of a live cell sample is a challenging task. Based on our experimental findings, the widely used Fourier ring correlation (FRC) method does not seem to be well suited for measuring the resolution of SIM live cell video sequences. Therefore, the resolution assessing methods based on Fourier spectrum analysis are often used. We introduce a measure based on circular average power spectral density (PSDca) estimated from a single SIM image (one video frame). PSDca describes the distribution of the power of a signal with respect to its spatial frequency. Spatial resolution corresponds to the cut-off frequency in Fourier space. In order to estimate the cut-off frequency from a noisy signal, we use a spectral subtraction method for noise suppression. In the future, this resolution assessment approach might prove useful also for single-molecule localization microscopy (SMLM) live cell imaging.

  15. A review of daylight illuminance determinations and energy implications

    Energy Technology Data Exchange (ETDEWEB)

    Li, Danny H.W. [Building Energy Research Group, Department of Building and Construction, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR (China)

    2010-07-15

    Daylighting is recognized as an important element in architecture and a useful strategy in energy-efficient building designs. Daylight gives a sense of cheeriness and brightness that can have a significant positive impact on the people. There is a scope for integrating daylight with electric light to reduce building energy use. The amount of daylight entering a building is mainly through window openings, which create in the indoor environment a more attractive and pleasing atmosphere, in addition to maximise visual access to the pleasant views of the outside world. Determinations of the exterior and interior daylight and lighting energy savings are key issues to demonstrate the benefits based on daylighting designs. This paper provides a review of daylight illuminance determinations and the lighting energy reductions due to daylighting schemes. The study includes daylight measurements, prediction of daylight illuminance under various sky conditions and potential electric lighting energy savings from daylight-linked lighting controls. The article aims at providing building professionals, practitioners and researchers more information and a better understanding of daylight for promoting effective daylighting designs and evaluations. (author)

  16. Exomoon Habitability Constrained by Illumination and Tidal Heating

    Science.gov (United States)

    2013-01-01

    Abstract The detection of moons orbiting extrasolar planets (“exomoons”) has now become feasible. Once they are discovered in the circumstellar habitable zone, questions about their habitability will emerge. Exomoons are likely to be tidally locked to their planet and hence experience days much shorter than their orbital period around the star and have seasons, all of which works in favor of habitability. These satellites can receive more illumination per area than their host planets, as the planet reflects stellar light and emits thermal photons. On the contrary, eclipses can significantly alter local climates on exomoons by reducing stellar illumination. In addition to radiative heating, tidal heating can be very large on exomoons, possibly even large enough for sterilization. We identify combinations of physical and orbital parameters for which radiative and tidal heating are strong enough to trigger a runaway greenhouse. By analogy with the circumstellar habitable zone, these constraints define a circumplanetary “habitable edge.” We apply our model to hypothetical moons around the recently discovered exoplanet Kepler-22b and the giant planet candidate KOI211.01 and describe, for the first time, the orbits of habitable exomoons. If either planet hosted a satellite at a distance greater than 10 planetary radii, then this could indicate the presence of a habitable moon. Key Words: Astrobiology—Extrasolar planets—Habitability—Habitable zone—Tides. Astrobiology 13, 18–46. PMID:23305357

  17. Optical image encryption based on interference under convergent random illumination

    International Nuclear Information System (INIS)

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2010-01-01

    In an optical image encryption system based on the interference principle, two pure phase masks are designed analytically to hide an image. These two masks are illuminated with a plane wavefront to retrieve the original image in the form of an interference pattern at the decryption plane. Replacement of the plane wavefront with convergent random illumination in the proposed scheme leads to an improvement in the security of interference based encryption. The proposed encryption scheme retains the simplicity of an interference based method, as the two pure masks are generated with an analytical method without any iterative algorithm. In addition to the free-space propagation distance and the two pure phase masks, the convergence distance and the randomized lens phase function are two new encryption parameters to enhance the system security. The robustness of this scheme against occlusion of the random phase mask of the randomized lens phase function is investigated. The feasibility of the proposed scheme is demonstrated with numerical simulation results

  18. QR code optical encryption using spatially incoherent illumination

    Science.gov (United States)

    Cheremkhin, P. A.; Krasnov, V. V.; Rodin, V. G.; Starikov, R. S.

    2017-02-01

    Optical encryption is an actively developing field of science. The majority of encryption techniques use coherent illumination and suffer from speckle noise, which severely limits their applicability. The spatially incoherent encryption technique does not have this drawback, but its effectiveness is dependent on the Fourier spectrum properties of the image to be encrypted. The application of a quick response (QR) code in the capacity of a data container solves this problem, and the embedded error correction code also enables errorless decryption. The optical encryption of digital information in the form of QR codes using spatially incoherent illumination was implemented experimentally. The encryption is based on the optical convolution of the image to be encrypted with the kinoform point spread function, which serves as an encryption key. Two liquid crystal spatial light modulators were used in the experimental setup for the QR code and the kinoform imaging, respectively. The quality of the encryption and decryption was analyzed in relation to the QR code size. Decryption was conducted digitally. The successful decryption of encrypted QR codes of up to 129  ×  129 pixels was demonstrated. A comparison with the coherent QR code encryption technique showed that the proposed technique has a signal-to-noise ratio that is at least two times higher.

  19. Turbine airfoil with ambient cooling system

    Science.gov (United States)

    Campbell, Jr, Christian X.; Marra, John J.; Marsh, Jan H.

    2016-06-07

    A turbine airfoil usable in a turbine engine and having at least one ambient air cooling system is disclosed. At least a portion of the cooling system may include one or more cooling channels configured to receive ambient air at about atmospheric pressure. The ambient air cooling system may have a tip static pressure to ambient pressure ratio of at least 0.5, and in at least one embodiment, may include a tip static pressure to ambient pressure ratio of between about 0.5 and about 3.0. The cooling system may also be configured such that an under root slot chamber in the root is large to minimize supply air velocity. One or more cooling channels of the ambient air cooling system may terminate at an outlet at the tip such that the outlet is aligned with inner surfaces forming the at least one cooling channel in the airfoil to facilitate high mass flow.

  20. Below-Ambient and Cryogenic Thermal Testing

    Science.gov (United States)

    Fesmire, James E.

    2016-01-01

    Thermal insulation systems operating in below-ambient temperature conditions are inherently susceptible to moisture intrusion and vapor drive toward the cold side. The subsequent effects may include condensation, icing, cracking, corrosion, and other problems. Methods and apparatus for real-world thermal performance testing of below-ambient systems have been developed based on cryogenic boiloff calorimetry. New ASTM International standards on cryogenic testing and their extension to future standards for below-ambient testing of pipe insulation are reviewed.

  1. Det ambientes fænomenologi

    DEFF Research Database (Denmark)

    Walther-Hansen, Mads

    2014-01-01

    Det ambiente: sansning, medialisering, omgivelse er et aktuelt og ambitiøst værk. Bogen skildrer hvordan ambiente fænomener har fået en stigende betydning i den moderne verden, og redegør for måden hvorpå det ambiente virker ind på hele vores oplevelseskultur. Det er en levende, uprætentiøs og frem...

  2. Ambient temperature signalling in plants.

    Science.gov (United States)

    Wigge, Philip A

    2013-10-01

    Plants are exposed to daily and seasonal fluctuations in temperature. Within the 'ambient' temperature range (about 12-27°C for Arabidopsis) temperature differences have large effects on plant growth and development, disease resistance pathways and the circadian clock without activating temperature stress pathways. It is this developmental sensing and response to non-stressful temperatures that will be covered in this review. Recent advances have revealed key players in mediating temperature signals. The bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) has been shown to be a hub for multiple responses to warmer temperature in Arabidopsis, including flowering and hypocotyl elongation. Changes in chromatin state are involved in transmitting temperature signals to the transcriptome. Determining the precise mechanisms of temperature perception represents an exciting goal for the field. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Hacking commercial quantum cryptography systems by tailored bright illumination

    Science.gov (United States)

    Lydersen, Lars; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Makarov, Vadim

    2010-10-01

    The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built from off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.

  4. Edge detection based on computational ghost imaging with structured illuminations

    Science.gov (United States)

    Yuan, Sheng; Xiang, Dong; Liu, Xuemei; Zhou, Xin; Bing, Pibin

    2018-03-01

    Edge detection is one of the most important tools to recognize the features of an object. In this paper, we propose an optical edge detection method based on computational ghost imaging (CGI) with structured illuminations which are generated by an interference system. The structured intensity patterns are designed to make the edge of an object be directly imaged from detected data in CGI. This edge detection method can extract the boundaries for both binary and grayscale objects in any direction at one time. We also numerically test the influence of distance deviations in the interference system on edge extraction, i.e., the tolerance of the optical edge detection system to distance deviation. Hopefully, it may provide a guideline for scholars to build an experimental system.

  5. Illuminating the Decision Path: The Yucca Mountain Site Recommendation

    Energy Technology Data Exchange (ETDEWEB)

    Knox, E.; Slothouber, L.

    2003-02-25

    On February 14, 2002, U.S. Secretary of Energy Spencer Abraham provided to the President the ''Recommendation by the Secretary of Energy Regarding the Suitability of the Yucca Mountain Site for a Repository Under the Nuclear Waste Policy Act of 1982.'' This Recommendation, along with supporting materials, complied with statutory requirements for communicating a site recommendation to the President, and it did more: in 49 pages, the Recommendation also spoke directly to the Nation, illuminating the methodology and considerations that led toward the decision to recommend the site. Addressing technical suitability, national interests, and public concerns, the Recommendation helped the public understand the potential risks and benefits of repository development and placed those risks and benefits in a meaningful national context.

  6. Reconstruction of Sky Illumination Domes from Ground-Based Panoramas

    Science.gov (United States)

    Coubard, F.; Lelégard, L.; Brédif, M.; Paparoditis, N.; Briottet, X.

    2012-07-01

    The knowledge of the sky illumination is important for radiometric corrections and for computer graphics applications such as relighting or augmented reality. We propose an approach to compute environment maps, representing the sky radiance, from a set of ground-based images acquired by a panoramic acquisition system, for instance a mobile-mapping system. These images can be affected by important radiometric artifacts, such as bloom or overexposure. A Perez radiance model is estimated with the blue sky pixels of the images, and used to compute additive corrections in order to reduce these radiometric artifacts. The sky pixels are then aggregated in an environment map, which still suffers from discontinuities on stitching edges. The influence of the quality of estimated sky radiance on the simulated light signal is measured quantitatively on a simple synthetic urban scene; in our case, the maximal error for the total sensor radiance is about 10%.

  7. Stereoscopic augmented reality with pseudo-realistic global illumination effects

    Science.gov (United States)

    de Sorbier, Francois; Saito, Hideo

    2014-03-01

    Recently, augmented reality has become very popular and has appeared in our daily life with gaming, guiding systems or mobile phone applications. However, inserting object in such a way their appearance seems natural is still an issue, especially in an unknown environment. This paper presents a framework that demonstrates the capabilities of Kinect for convincing augmented reality in an unknown environment. Rather than pre-computing a reconstruction of the scene like proposed by most of the previous method, we propose a dynamic capture of the scene that allows adapting to live changes of the environment. Our approach, based on the update of an environment map, can also detect the position of the light sources. Combining information from the environment map, the light sources and the camera tracking, we can display virtual objects using stereoscopic devices with global illumination effects such as diffuse and mirror reflections, refractions and shadows in real time.

  8. Plasmonic leak-free focusing lens under radially polarized illumination

    International Nuclear Information System (INIS)

    Li, Xiaowei; Tan, Qiaofeng; Bai, Benfeng; Jin, Guofan

    2010-01-01

    A plasmonic leak-free focusing lens with two asymmetric concentric ring slits under radially polarized illumination is proposed. Each ring slit in the plasmonic lens is designed to generate surface plasmon polaritons (SPPs) with a relative initial phase controlled by the ring slit parameters. Through mutual interference of the SPPs with different phases excited by the two concentric ring slits at the output metal–dielectric interface, the field intensity towards the center of the focusing lens can be enhanced while that leaking to the counter-focus direction is effectively suppressed. The optimal parameters of the plasmonic leak-free lens are theoretically obtained by satisfying the above condition and its focusing performance is demonstrated by numerical simulation. Furthermore, a plasmonic leak-free lens with multiple double-slit groups is proposed and discussed, which exhibits a higher energy density at the focusing spot of the output interface

  9. Cities of light two centuries of urban illumination

    CERN Document Server

    Isenstadt, Sandy; Neumann, Dietrich

    2014-01-01

    Cities of Light is the first global overview of modern urban illumination, a development that allows human wakefulness to colonize the night, doubling the hours available for purposeful and industrious activities.  Urban lighting is undergoing a revolution due to recent developments in lighting technology, and increased focus on sustainability and human-scaled environments. Cities of Light is expansive in coverage, spanning two centuries and touching on developments on six continents, without diluting its central focus on architectural and urban lighting.  Covering history, geography, theory, and speculation in urban lighting, readers will have numerous points of entry into the book, finding it easy to navigate for a quick reference and or a coherent narrative if read straight through. With chapters written by respected scholars and highly-regarded contemporary practitioners, this book will delight students and practitioners of architectural and urban history, area and cultural studies, and lighting desig...

  10. Illuminating the Decision Path: The Yucca Mountain Site Recommendation

    International Nuclear Information System (INIS)

    Knox, E.; Slothouber, L.

    2003-01-01

    On February 14, 2002, U.S. Secretary of Energy Spencer Abraham provided to the President the ''Recommendation by the Secretary of Energy Regarding the Suitability of the Yucca Mountain Site for a Repository Under the Nuclear Waste Policy Act of 1982.'' This Recommendation, along with supporting materials, complied with statutory requirements for communicating a site recommendation to the President, and it did more: in 49 pages, the Recommendation also spoke directly to the Nation, illuminating the methodology and considerations that led toward the decision to recommend the site. Addressing technical suitability, national interests, and public concerns, the Recommendation helped the public understand the potential risks and benefits of repository development and placed those risks and benefits in a meaningful national context

  11. X-ray total reflection mirrors for coherent illumination

    CERN Document Server

    Ishikawa, T; Yabashi, M; Souvorov, A; Yamauchi, K; Yamamura, K; Mimura, H; Saito, A; Mori, Y

    2002-01-01

    X-ray mirrors for coherent illumination demand much higher surface quality than is achievable with the conventional polishing techniques. Plasma chemical vaporization machining (CVM) and elastic emission machining (EEM) have been applied for x-ray mirror manufacturing. Figure error of a flat silicon single crystal mirrors made with CVM+EEM process was reduced to 2.0 nm peak-to-valley and 0.2 nm RMS. The machining process was also applied to make elliptical mirrors. One-dimensional focusing with a single elliptical mirror showed diffraction-limited properties with the focal width of 200 nm. Two-dimensional focusing with Kirkpatric-Baez configuration gave a focal spot size of 200 nm x 200 nm. (author)

  12. RECONSTRUCTION OF SKY ILLUMINATION DOMES FROM GROUND-BASED PANORAMAS

    Directory of Open Access Journals (Sweden)

    F. Coubard

    2012-07-01

    Full Text Available The knowledge of the sky illumination is important for radiometric corrections and for computer graphics applications such as relighting or augmented reality. We propose an approach to compute environment maps, representing the sky radiance, from a set of ground-based images acquired by a panoramic acquisition system, for instance a mobile-mapping system. These images can be affected by important radiometric artifacts, such as bloom or overexposure. A Perez radiance model is estimated with the blue sky pixels of the images, and used to compute additive corrections in order to reduce these radiometric artifacts. The sky pixels are then aggregated in an environment map, which still suffers from discontinuities on stitching edges. The influence of the quality of estimated sky radiance on the simulated light signal is measured quantitatively on a simple synthetic urban scene; in our case, the maximal error for the total sensor radiance is about 10%.

  13. Imaging of Phase Objects using Partially Coherent Illumination

    Energy Technology Data Exchange (ETDEWEB)

    Ravizza, F. L. [Univ. of Arizona, Tucson, AZ (United States)

    2013-01-01

    Screening high-power laser optics for light intensifying phase objects that cause laserinduced damage on downstream optics is critical to sustaining laser operation. Identifying such flaws on large-apertures is quite challenging since they are relatively small and invisible to conventional inspection methods. A Linescan Phase Differential Imaging (LPDI) system was developed to rapidly identify these flaws on large-aperture optics within a single full-aperture dark-field image. We describe a two-step production phase object screening process consisting of LPDI mapping and image analysis, followed by high-resolution interferometry and propagation based evaluation of the downstream damage potential of identified flaws. An image simulation code capable of modeling the LPDI partially coherent illumination was used to optimize its phase object sensitivity.

  14. Novel cylindrical illuminator tip for ultraviolet light delivery

    Science.gov (United States)

    Shangguan, HanQun; Haw, Thomas E.; Gregory, Kenton W.; Casperson, Lee W.

    1993-06-01

    The design, processing, and sequential testing of a novel cylindrical diffusing optical fiber tip for ultraviolet light delivery is described. This device has been shown to uniformly (+/- 15%) illuminate angioplasty balloons, 20 mm in length, that are used in an experimental photochemotherapeutic treatment of swine intimal hyperplasia. Our experiments show that uniform diffusing tips of epoxy mixed with Al2O3 powder. To improve the uniformity and ease of fabrication, we have evaluated a new device configuration where the tip is etched into a modified conical shape, and the distal end face is polished and then coated with an optically opaque epoxy. This is shown to uniformly scatter approximately 70% of the light launched into the fiber without forward transmission.

  15. Re-designing illumination level in printing working area

    Science.gov (United States)

    Wahyuni, D.; Tambunan, M.; Panjaitan, N.; Budiman, I.

    2018-02-01

    This research was conducted in four printing business in Medan city. The illumination level on the research object is very low around 30 Lux far below the required value of government regulation at 200 Lux. Poor lighting has an impact on the number of defective products that pass the inspection, so we need to improve the workspace lighting to improve the quality of work. The method of determining the measuring point follows SNI 16-7062-2004, and the measuring instrument used is 4 in 1 Environment Meter. The results show that almost all workspaces under study require improved lighting, because the light bulbs used are not able to meet the lighting needs. This research recommends improving the workspace lighting using LED (Light Emitting Diode) lights because it has high energy efficiency and relatively more lifetime compared to the existing lamp.

  16. Magneto-controlled illumination with opto-fluidics

    International Nuclear Information System (INIS)

    Malynych, Serhiy Z.; Tokarev, Alexander; Hudson, Stephen; Chumanov, George; Ballato, John; Kornev, Konstantin G.

    2010-01-01

    Imaging of micro- and nanofluidics is a challenge since the size of the channels is so small that the installment of additional optical and mechanical switches is very difficult. The size of the device and associated increase in viscous dissipation constitute another constraint. In response to these limitations, this work proposes and demonstrates the manipulation of light by adding a functional lens to control the light on demand. In the present work, this lens is realized by filling a hollow fiber with a colloid of superparamagnetic Fe 3 O 4 nanoparticles. When the propagation of light is perpendicular to the magnetic field, this lens stretches the circular beam into a ribbon yielding a larger visible area. Potentially, one can apply a rotating magnetic field thus illuminating a larger spot size or creating other beam geometries. Such composite fibers might also be of value for Faraday isolation and other magneto-optic effects in optical fibers.

  17. Mirror Illumination and Spillover Measurements of the Atacama Cosmology Telescope

    Science.gov (United States)

    Gallardo, Patricio; Dunner, Rolando; Wollack, Ed; Jerez-Hanckes, Carlos

    2012-01-01

    The Atacama Cosmology Telescope (ACT) is a 6 m telescope designed to map the Cosmic Microwave Background (CMB) simultaneously at 145 GHz, 220GHz and 280GHz, The receiver in ACT, the Millimeter Bolometer Array Camera, features 1000 TES bolometers in each band, The detector performance depends critically on the total optical loading, requiring the spmover contributions from the optics to be minimal. This inspired the use of a cold Lyot stop to limit the illumination of the primary and the use of guard rings surrounding the primary and secondary reflectors. Here, we present a direct measurement of the illumination aperture for both reflectors and of the attenuation level outside the main optical path. We used a 145 GHz, 1 m W source and a chopper wheel to produce a time-varying signal with a broad heam proflle, We sampled the response of the camera for different locations of the source, placed in front and beside the primary and secondary mirrors. The aperture of the primary was measured to be 5,72 plus or minus 0,17m in diameter (95 plus or minus 3% of its geometrical size), while the aperture of the secondary yielded 2 plus or minus 0.12m in diameter. Both apertures are consistent with the optical design. Comparing to previous measurements of the beam solid angle from planet observations, we estimate an optical efficiency of 72.3 plus or minus 4,8%. We found that the attenuation outside the primary aperture was -16 plus or minus 2dB, which is below the theoretical expectations, and -22 plus or minus 1 dB outside the secondary aperture, which is consistent with simulations. These results motivated the extension of the baffles surrounding the secondary mirror, with the following reduction in detector optical loading from 2,24 pW to 188pW.

  18. Color of illumination during growth affects LHCII chiral macroaggregates in pea plant leaves.

    Science.gov (United States)

    Gussakovsky, Eugene E; Shahak, Yosepha; Schroeder, Dana F

    2007-02-01

    To determine whether the color of illumination under which plants are grown, affects the structure of photosynthetic antennae, pea plants were grown under either blue-enriched, red-enriched, or white light. Carotenoid content of isolated chloroplasts was found to be insensitive to the color of illumination during growth, while chlorophyll a/b ratio in chloroplasts isolated from young illuminated leaves showed susceptibility to color. Color of illumination affects the LHCII chiral macroaggregates in intact leaves and isolated chloroplasts, providing light-induced alteration of the handedness of the LHCII chiral macroaggregate, as measured with circular dichroism and circularly polarized luminescence. The susceptibility of handedness to current illumination (red light excitation of chlorophyll fluorescence) is dependent on the color under which the plants were grown, and was maximal for the red-enriched illumination. We propose the existence of a long-term (growth period) color memory, which influences the susceptibility of the handedness of LHCII chiral macroaggregates to current light.

  19. Establishment Of Illumination System For Investigation Of Monochromatic Lights Combination Effects On In Vitro Plant Growth

    International Nuclear Information System (INIS)

    Le Tien Thanh; Le Ngoc Trieu; Nguyen Tuong Mien; Huynh Thi Trung; Phan Quoc Minh

    2014-01-01

    Super blue and red light LEDs and other electric, electronic components are used to design and establish 11 independent illumination systems, each system can arbitrarily control to operate at 55 molarities of illumination which are different from together in monochromatic lights combination and total illumination intensity based on the microcontrollers. Programs for loading to microcontrollers were created to base on theoretical calculation and experimental correction. The illumination cycles can be controlled by setting the timer. These 11 systems and another fluorescent light illumination were used to execute the experiment for investigation the effects of monochromatic lights combination on in vitro shoot proliferation stage in Chrysanthemum and Phalaenopsis orchid. Results from this experiment showed that illumination intensity of 400 lux is suitable for chrysanthemum, 750 lux is suitable for Phalaenopsis orchid and rate of 70% red light-30% blue light are suitable for both kinds of these plants. (author)

  20. Laser fusion target illumination optimization with consideration of the beam divergence

    International Nuclear Information System (INIS)

    Grzanna, J.; Schoennagel, H.

    1982-09-01

    Using a focusing system with a great focal length it is demonstrated that the radiation divergence considerably influences the illumination optimization. If the channel beam is composed of several single beams, there are two optimum illumination variants: the channel beam tangent and the single beam tangent illumination. Further, it is shown that the illumination channel distribution function can vary in the central region without any effect on the illumination uniformity. The deviation at the periphery is more critical. The most homogeneous illumination and favourable energy transfer would be obtained by low radiation divergence and optimum lateral and axial defocusing of the single beam imaging a suitable near-field intensity pattern on the target surface. It is emphasized that the estimation was made without considering the plasma parameters and the dynamic variation in time. (author)

  1. Evaluating Ambient Displays in the Wild

    DEFF Research Database (Denmark)

    Messeter, Jörn; Molenaar, Daryn

    A prominent issue for evaluating ambient displays has been the conflict between the relative intrusiveness of evaluation methods and the intention to keep the display at the periphery of the user’s attention. There is a general lack of research discussing the difficulties of evaluating ambient di...

  2. Hybrid Logical Analyses of the Ambient Calculus

    DEFF Research Database (Denmark)

    Bolander, Thomas; Hansen, Rene Rydhof

    2010-01-01

    In this paper, hybrid logic is used to formulate three control flow analyses for Mobile Ambients, a process calculus designed for modelling mobility. We show that hybrid logic is very well-suited to express the semantic structure of the ambient calculus and how features of hybrid logic can...

  3. Ambient air contamination: Characterization and detection techniques

    Science.gov (United States)

    Nulton, C. P.; Silvus, H. S.

    1985-01-01

    Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

  4. Embedded systems design issues in ambient intelligence

    NARCIS (Netherlands)

    Aarts, E.H.L.; Roovers, R.L.J.; Basten, A.A.; Geilen, M.C.W.; Groot, de H.W.H.

    2003-01-01

    The vision of ambient intelligence opens a world of unprecedented ex.periences: the interaction of people with electronic devices is changed as context awareness, natural interfaces and ubiquitous availability of information are realized. We analyze the consequences of the ambient intelligence

  5. Freedom and privacy in ambient intelligence

    NARCIS (Netherlands)

    Brey, Philip A.E.

    2006-01-01

    This paper analyzes ethical aspects of the new paradigm of Ambient Intelligence, which is a combination of Ubiquitous Computing and Intelligent User Interfaces (IUI’s). After an introduction to the approach, two key ethical dimensions will be analyzed: freedom and privacy. It is argued that Ambient

  6. Control Flow Analysis for BioAmbients

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Priami, C.

    2007-01-01

    This paper presents a static analysis for investigating properties of biological systems specified in BioAmbients. We exploit the control flow analysis to decode the bindings of variables induced by communications and to build a relation of the ambients that can interact with each other. We...

  7. Spatial Analysis of BioAmbients

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming; Pilegaard, Henrik

    2004-01-01

    Programming language technology can contribute to the development and understanding of Systems Biology by providing formal calculi for specifying and analysing the dynamic behaviour of biological systems. Our focus is on BioAmbients, a variation of the ambient calculi developed for modelling...

  8. Contabilidade ambiental o passaporte para a competitividade

    Directory of Open Access Journals (Sweden)

    Maria Elisabeth Pereira Kraemer

    2002-03-01

    Full Text Available Como todos os problemas ambientais provocaram grandes danos irreversíveis, que incidiram e incidem agora em todos os países subdesenvolvidos e desenvolvidos, nasce, então, como necessidade imperiosa, introduzir nos nossos sistemas econômicos a Contabilidade Ambiental, pois as organizações, até alguns anos atrás, preocupavam-se apenas com a eficiência dos sistemas produtivos. Chegamos a "era da revolução ambiental", e o ambiente não somente aparece como um conjunto de problemas relativos ao controle da contaminação, mas representa um custo no crescimento econômico. Neste sentido, o contador precisa de uma formação que se estenda além dos limites das técnicas e dos procedimentos. É necessário acrescentar o registro contábil do meio ambiente, dada a velocidade de sua afetação e a influência do mundo atual na utilização e disposição dos recursos naturais. Deve ser considerado como um dos princípios contábeis, onde é um desafio para a contabilidade. Precisa ser considerada como uma ciência contábil integrada, pois com a ciência ecológica e outras ciências são responsáveis pela natureza onde devem ser aplicados critérios de proteção ambiental, demonstrando que os recursos naturais constituem nosso principal capital. Partindo dessa premissa é que este trabalho está enfocando os seguintes tópicos: Responsabilidade Social da Empresa; A Empresa e o Meio Ambiente; Gestão Ambiental; Sistema de Gestão Ambiental; Ações para Preservar o Meio Ambiente - O Protocolo Verde, A Contabilidade, Custos Ambientais, Ativo Ambiental, Passivo Ambiental, Patrimônio Ambiental, Contabilidade Ambiental e Contabilidade Ambiental - o Passaporte para a Competitividade.

  9. A fundamental study on the influence of the illuminant conditions for the visibility

    International Nuclear Information System (INIS)

    Fukui, Hirokazu; Ohuchi, Hiroko; Akagi, Sigefumi; Natori, Kazuyuki

    2002-01-01

    This research was done to explain the way of color combinations for the signs that are excellent in the visibility. The research was composed by three experiments, color naming experiment and the visibility experiment 1 and 2. In the color naming experiment, what kind of color combinations investigated whether a target color could be judged precisely under the various lighting illuminant. The visibility experiment 1 examined the various color combinations that became effective for the visibility under the illuminant. And, the visibility experiment 2 examined the color combinations that were effective for the visibility from the lighting illuminant and the illuminance. Yellow in white background, white in yellow background, purple in red background, purple in green background, as for these 4 color combinations, it became clear that it is the color combination which needed attention under all the lighting illuminants from the color naming experiment and the visibility experiment 1. In the visibility experiment 2, relative visual acuity became more than 0.7 in all the lighting illuminants if there was a ΔL * from the background and the target beyond 30 in the case of the illuminance of 5001x. And, when illuminance was 501x, it became clear that it become less than 0.7 by all the color schemes as for the relative visual acuity in all the lighting illuminants. (author)

  10. Effect of Illumination on Ocular Status Modifications Induced by Short-Term 3D TV Viewing

    Directory of Open Access Journals (Sweden)

    Yuanyuan Chen

    2017-01-01

    Full Text Available Objectives. This study aimed to compare changes in ocular status after 3D TV viewing under three modes of illumination and thereby identify optimal illumination for 3D TV viewing. Methods. The following measures of ocular status were assessed: the accommodative response, accommodative microfluctuation, accommodative facility, relative accommodation, gradient accommodative convergence/accommodation (AC/A ratio, phoria, and fusional vergence. The observers watched 3D television for 90 minutes through 3D shutter glasses under three illumination modes: A, complete darkness; B, back illumination (50 lx; and C, front illumination (130 lx. The ocular status of the observers was assessed both before and after the viewing. Results. After 3D TV viewing, the accommodative response and accommodative microfluctuation were significantly changed under illumination Modes A and B. The near positive fusional vergence decreased significantly after the 90-minute 3D viewing session under each illumination mode, and this effect was not significantly different among the three modes. Conclusions. Short-term 3D viewing modified the ocular status of adults. The least amount of such change occurred with front illumination, suggesting that this type of illumination is an appropriate mode for 3D shutter TV viewing.

  11. A fundamental study on the influence of the illuminant conditions for the visibility

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Hirokazu [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan); Ohuchi, Hiroko; Akagi, Sigefumi; Natori, Kazuyuki [Japan Color Research Institute, Tokyo (Japan)

    2002-09-01

    This research was done to explain the way of color combinations for the signs that are excellent in the visibility. The research was composed by three experiments, color naming experiment and the visibility experiment 1 and 2. In the color naming experiment, what kind of color combinations investigated whether a target color could be judged precisely under the various lighting illuminant. The visibility experiment 1 examined the various color combinations that became effective for the visibility under the illuminant. And, the visibility experiment 2 examined the color combinations that were effective for the visibility from the lighting illuminant and the illuminance. Yellow in white background, white in yellow background, purple in red background, purple in green background, as for these 4 color combinations, it became clear that it is the color combination which needed attention under all the lighting illuminants from the color naming experiment and the visibility experiment 1. In the visibility experiment 2, relative visual acuity became more than 0.7 in all the lighting illuminants if there was a {delta}L{sup *} from the background and the target beyond 30 in the case of the illuminance of 5001x. And, when illuminance was 501x, it became clear that it become less than 0.7 by all the color schemes as for the relative visual acuity in all the lighting illuminants. (author)

  12. Uniform illumination rendering using an array of LEDs: a signal processing perspective

    OpenAIRE

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.; Linnartz, J.P.M.G.; Rietman, R.

    2009-01-01

    An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic illumination pattern, i.e., the light pattern of a single LED, and the setting of LED illumination levels, respectively. Thereafter, we propose to use the relative mean squared error as the cost function ...

  13. Disparity Map Generation from Illumination Variant Stereo Images Using Efficient Hierarchical Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Viral H. Borisagar

    2014-01-01

    Full Text Available A novel hierarchical stereo matching algorithm is presented which gives disparity map as output from illumination variant stereo pair. Illumination difference between two stereo images can lead to undesirable output. Stereo image pair often experience illumination variations due to many factors like real and practical situation, spatially and temporally separated camera positions, environmental illumination fluctuation, and the change in the strength or position of the light sources. Window matching and dynamic programming techniques are employed for disparity map estimation. Good quality disparity map is obtained with the optimized path. Homomorphic filtering is used as a preprocessing step to lessen illumination variation between the stereo images. Anisotropic diffusion is used to refine disparity map to give high quality disparity map as a final output. The robust performance of the proposed approach is suitable for real life circumstances where there will be always illumination variation between the images. The matching is carried out in a sequence of images representing the same scene, however in different resolutions. The hierarchical approach adopted decreases the computation time of the stereo matching problem. This algorithm can be helpful in applications like robot navigation, extraction of information from aerial surveys, 3D scene reconstruction, and military and security applications. Similarity measure SAD is often sensitive to illumination variation. It produces unacceptable disparity map results for illumination variant left and right images. Experimental results show that our proposed algorithm produces quality disparity maps for both wide range of illumination variant and invariant stereo image pair.

  14. Effect of display type and room illuminance in chest radiographs

    International Nuclear Information System (INIS)

    Liukkonen, Esa; Jartti, Airi; Haapea, Marianne; Oikarinen, Heljae; Ahvenjaervi, Lauri; Mattila, Seija; Nevala, Terhi; Palosaari, Kari; Perhomaa, Marja; Nieminen, Miika T.

    2016-01-01

    To compare diagnostic accuracy in the detection of subtle chest lesions on digital chest radiographs using medical-grade displays, consumer-grade displays, and tablet devices under bright and dim ambient light. Five experienced radiologists independently assessed 50 chest radiographs (32 with subtle pulmonary findings and 18 without apparent findings) under bright (510 lx) and dim (16 lx) ambient lighting. Computed tomography was used as the reference standard for interstitial and nodular lesions and follow-up chest radiograph for pneumothorax. Diagnostic accuracy and sensitivity were calculated for assessments carried out in all displays and compared using the McNemar test. The level of significance was set to p < 0.05. Significant differences in sensitivity between the assessments under bright and dim lighting were found among consumer-grade displays in interstitial opacities with, and in pneumothorax without, Digital Imaging and Communication in Medicine-Grayscale Standard Display Function (DICOM-GSDF) calibration. Compared to 6 megapixel (MP) display under bright lighting, sensitivity in pneumothorax was lower in the tablet device and the consumer-grade display. Sensitivity in interstitial opacities was lower in the DICOM-GSDF calibrated consumer-grade display. A consumer-grade display with or without DICOM-GSDF calibration or a tablet device is not suitable for reading digital chest radiographs in bright lighting. No significant differences were observed between five displays in dim light. (orig.)

  15. CONFLITOS INTERPESSOAIS NO AMBIENTE ORGANIZACIONAL

    Directory of Open Access Journals (Sweden)

    Gabriela Paganini de Souza

    2014-07-01

    Full Text Available O presente artigo analisa e confirma a existência de impactos ocasionados pelos conflitos em um ambiente organizacional, através de pesquisa de campo realizada a partir de um estudo de caso e a comparação com a literatura adotada. A empresa escolhida foi abordada a partir de questionários, que foram respondidos pelos colaboradores e também pelo gestor. Percebeu-se que esses impactos são complexos de mensurar, principalmente os financeiros, que normalmente ficam ocultos por muito tempo. Entretanto, não se pode negar sua existência, pois estes tendem à piorar quando não são considerados.  Foi observado com a pesquisa que a conduta adotada para intermediar os conflitos está diretamente ligada ao sucesso de impedir impactos negativos aos indivíduos e à organização como um todo. Essas condutas, quando bem aplicadas podem contribuir reverter o impacto de um conflito, fazendo com que ele seja um fator motivador de mudanças e um estímulo para que os indivíduos demonstrem seus potenciais.

  16. GENES, POBLACIONES, AMBIENTES Y NACIONES

    Directory of Open Access Journals (Sweden)

    Noem\\u00ED Acreche

    2010-01-01

    Full Text Available Se estudió la estructura genética de 32 poblaciones de Argentina, Bolivia y Paraguay en función de las frecuencias génicas de ocho sistemas de grupos eritocitarios. Los sistemas incluidos son: ABO, MN, Ss, DI, P, Cc, Dd y Ee. En el caso de Bolivia, Paraguay y el Chaco Argentino, los datos fueron obtenidos de la bibliografía. La relación entre las poblaciones y diferentes criterios de agrupación (Ambiente, País, Grupo Lingüístico y Altitud fueron evaluadas por medio de Análisis Discriminante. Se consideró el porcentaje de casos correctamente clasificados como medida de la relación entre el conjunto de variables analizadas y el criterio de agrupación. Se encontró que tanto las categorías geoestructurales como lingüísticas establecidas tienen mayor relación con la estructura genética de las poblaciones incluidas en el análisis que las fronteras nacionales, por lo que se concluye que el aislamiento reproductivo entre poblaciones, necesario para la diferenciación, se produce por diferencias culturales o del territorio de ocupación antes que por las fronteras políticas establecidas.

  17. Alternative Fuel Guidelines for Alternative Transportation Systems.

    Science.gov (United States)

    2011-01-31

    The Volpe Center documented the increased use of alternative fuels on vehicles owned and operated by federal land management agencies. For each alternative fuel type, the Volpe Center documented the availability of vehicles, fueling mechanisms and pr...

  18. Structural Pathways of Cytokines May Illuminate Their Roles in Regulation of Cancer Development and Immunotherapy

    International Nuclear Information System (INIS)

    Guven-Maiorov, Emine; Acuner-Ozbabacan, Saliha Ece; Keskin, Ozlem; Gursoy, Attila; Nussinov, Ruth

    2014-01-01

    Cytokines are messengers between tissues and the immune system. They play essential roles in cancer initiation, promotion, metastasis, and immunotherapy. Structural pathways of cytokine signaling which contain their interactions can help understand their action in the tumor microenvironment. Here, our aim is to provide an overview of the role of cytokines in tumor development from a structural perspective. Atomic details of protein-protein interactions can help in understanding how an upstream signal is transduced; how higher-order oligomerization modes of proteins can influence their function; how mutations, inhibitors or antagonists can change cellular consequences; why the same protein can lead to distinct outcomes, and which alternative parallel pathways can take over. They also help to design drugs/inhibitors against proteins de novo or by mimicking natural antagonists as in the case of interferon-γ. Since the structural database (PDB) is limited, structural pathways are largely built from a series of predicted binary protein-protein interactions. Below, to illustrate how protein-protein interactions can help illuminate roles played by cytokines, we model some cytokine interaction complexes exploiting a powerful algorithm (PRotein Interactions by Structural Matching—PRISM)

  19. Structural Pathways of Cytokines May Illuminate Their Roles in Regulation of Cancer Development and Immunotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Guven-Maiorov, Emine; Acuner-Ozbabacan, Saliha Ece; Keskin, Ozlem; Gursoy, Attila [Center for Computational Biology and Bioinformatics and College of Engineering, Koc University, Rumelifeneri Yolu, 34450 Sariyer Istanbul (Turkey); Nussinov, Ruth, E-mail: nussinor@helix.nih.gov [Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702 (United States); Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel)

    2014-03-25

    Cytokines are messengers between tissues and the immune system. They play essential roles in cancer initiation, promotion, metastasis, and immunotherapy. Structural pathways of cytokine signaling which contain their interactions can help understand their action in the tumor microenvironment. Here, our aim is to provide an overview of the role of cytokines in tumor development from a structural perspective. Atomic details of protein-protein interactions can help in understanding how an upstream signal is transduced; how higher-order oligomerization modes of proteins can influence their function; how mutations, inhibitors or antagonists can change cellular consequences; why the same protein can lead to distinct outcomes, and which alternative parallel pathways can take over. They also help to design drugs/inhibitors against proteins de novo or by mimicking natural antagonists as in the case of interferon-γ. Since the structural database (PDB) is limited, structural pathways are largely built from a series of predicted binary protein-protein interactions. Below, to illustrate how protein-protein interactions can help illuminate roles played by cytokines, we model some cytokine interaction complexes exploiting a powerful algorithm (PRotein Interactions by Structural Matching—PRISM)

  20. Structural Pathways of Cytokines May Illuminate Their Roles in Regulation of Cancer Development and Immunotherapy

    Directory of Open Access Journals (Sweden)

    Emine Guven-Maiorov

    2014-03-01

    Full Text Available Cytokines are messengers between tissues and the immune system. They play essential roles in cancer initiation, promotion, metastasis, and immunotherapy. Structural pathways of cytokine signaling which contain their interactions can help understand their action in the tumor microenvironment. Here, our aim is to provide an overview of the role of cytokines in tumor development from a structural perspective. Atomic details of protein-protein interactions can help in understanding how an upstream signal is transduced; how higher-order oligomerization modes of proteins can influence their function; how mutations, inhibitors or antagonists can change cellular consequences; why the same protein can lead to distinct outcomes, and which alternative parallel pathways can take over. They also help to design drugs/inhibitors against proteins de novo or by mimicking natural antagonists as in the case of interferon-γ. Since the structural database (PDB is limited, structural pathways are largely built from a series of predicted binary protein-protein interactions. Below, to illustrate how protein-protein interactions can help illuminate roles played by cytokines, we model some cytokine interaction complexes exploiting a powerful algorithm (PRotein Interactions by Structural Matching—PRISM.

  1. Dense and refined microstructure 3D measurement method based on an optical microscope and varying illuminations

    International Nuclear Information System (INIS)

    Li, Zhongwei; Li, Y F

    2011-01-01

    We propose a novel microscopic photometric stereo (MPS) method based on a conventional optical microscope and varying illuminations for dense and refined microstructure 3D measurement. To guarantee the flexibility of the MPS, an uncalibrated photometric stereo (UPS) method, which does not require a priori knowledge of the light-source direction or the light-source intensity, is employed to recover surface normals and albedos from the captured multiple micro-images. Although the UPS has been studied before, there are some particular issues to be addressed to make it suitable for microscopic cases. For resolving the inherent generalized bas-relief (GBR) ambiguity of the UPS, we present a GBR disambiguation method based on a framework of entropy minimization, and extend it using a graph-cut energy minimization to decrease the influence of noise and further refine the recovered surface normal. The proposed MPS method has been tested on synthetic as well as real images and very encouraging results have been obtained. The experimental results show that this novel method can reconstruct dense and refined 3D points for the microstructure. It is an easy-to-implement yet effective alternative method for microstructure 3D measurement and can be applied to many potential fields

  2. Digital image color analysis compared to direct dental CIE colorimeter assessment under different ambient conditions.

    Science.gov (United States)

    Knösel, Michael; Attin, Rengin; Jung, Klaus; Brunner, Edgar; Kubein-Meesenburg, Dietmar; Attin, Thomas

    2009-04-01

    To evaluate the concordance and repeatability of two in vivo methods for dental color assessment and to clarify the influence of different ambient light conditions and subject's head position on the assessed color variables. Color assessments were performed by two examiners on 16 arbitrarily selected subjects under two different, standardized conditions of illumination and at two different standardized head angulations. CIE (L*a*b*) data for upper and lower central incisors were recorded in two different ways: (1) by an intra-oral contact dental colorimeter and (2) by processing digital images for performing color calculation using Adobe Photoshop software. The influence of the different ambient conditions on both methods, as well as the concordance of measurements was analyzed statistically using several mixed linear models. Ambient light as a single factor had no significant influence on maxillary L*, a* and b* values, but it did have an effect on mandible assessments. Head angulation variation resulted in significant L* value differences using the photo method. The operator had a significant influence on values a* and b* for the photo method and on a* values for the colorimeter method. In fully lit ambient condition, the operator had a significant influence on the segregated L*, a*, and b* values. With dimmed lights, head angulation became significant, but not the operator. Evaluation of segregated L* values was error prone in both methods. Comparing both methods, deltaE values did not exceed 2.85 units, indicating that color differences between methods and recorded under varying ambient conditions were well below the sensitivity of the naked eye.

  3. Low light illumination study on commercially available homojunction photovoltaic cells

    International Nuclear Information System (INIS)

    Russo, Johnny; Ray, William; Litz, Marc S.

    2017-01-01

    Highlights: • COTS PV cells are tested under indoor and narrow light spectra. • InGaP is the most efficient under low light conditions (0.5–100 μW_o_p_t/cm"2). • InGaP is selected for isotope battery. • Optimal incident wavelength (614 nm) for InGaP is identified in model. - Abstract: Low illumination (10"−"4 suns) and indoor light energy harvesting is needed to meet the demands of zero net energy (ZNE) building, Internet of Things (IoT), and beta-photovoltaic energy harvesting systems to power remote sensors. Photovoltaic (PV) solar cells under low intensity and narrow (±40 nm) light spectrum conditions are not well characterized nor developed, especially for commercially available devices and scalable systems. PV operating characteristics under 1 sun illumination decrease at lower light intensity and narrow spectrum conditions (efficiency drops from ∼25% at 100 mW_o_p_t/cm"2 to 2% at 1 μW_o_p_t/cm"2). By choosing a PV with a bandgap that matches the light source operating wavelength, the total system efficiency can be improved. By quantifying losses on homojunction photovoltaics (thermalization and leakage current), we have determined the theoretical optimized efficiency for a set of PV material and a selected set of light sources. We measure single-junction solar cells’ parameters under three different light sources (indoor light and narrow spectrum LED sources) with light intensities ranging from 0.5 to 100 μW_o_p_t/cm"2. Measurements show that indium gallium phosphide (InGaP) PV has the highest surface power density and conversion efficiency (29% under ≈1 μW_o_p_t/cm"2 from a 523 nm central peak LED). A beta-photovoltaic experimental study identifies InGaP to be optimized for use with the ZnS:Cu, Al and tritium at STP. The results have guided the selection of PV material for scalable isotope batteries and other low-light energy harvesting systems.

  4. Automated Field-of-View, Illumination, and Recognition Algorithm Design of a Vision System for Pick-and-Place Considering Colour Information in Illumination and Images.

    Science.gov (United States)

    Chen, Yibing; Ogata, Taiki; Ueyama, Tsuyoshi; Takada, Toshiyuki; Ota, Jun

    2018-05-22

    Machine vision is playing an increasingly important role in industrial applications, and the automated design of image recognition systems has been a subject of intense research. This study has proposed a system for automatically designing the field-of-view (FOV) of a camera, the illumination strength and the parameters in a recognition algorithm. We formulated the design problem as an optimisation problem and used an experiment based on a hierarchical algorithm to solve it. The evaluation experiments using translucent plastics objects showed that the use of the proposed system resulted in an effective solution with a wide FOV, recognition of all objects and 0.32 mm and 0.4° maximal positional and angular errors when all the RGB (red, green and blue) for illumination and R channel image for recognition were used. Though all the RGB illumination and grey scale images also provided recognition of all the objects, only a narrow FOV was selected. Moreover, full recognition was not achieved by using only G illumination and a grey-scale image. The results showed that the proposed method can automatically design the FOV, illumination and parameters in the recognition algorithm and that tuning all the RGB illumination is desirable even when single-channel or grey-scale images are used for recognition.

  5. Calidad ambiental interior: bienestar, confort y salud

    Directory of Open Access Journals (Sweden)

    Francisco Vargas Marcos

    2005-01-01

    Full Text Available Distintas formas de interpretar las condiciones ambientales han llevado al desarrollo de conceptos tales como edificio enfermo, calidad del aire o calidad ambiental interior, todos ellos encaminados a entender la complejidad de los contaminantes en los ambientes cerrados y las implicaciones sobre la salud de la población. La propuesta de "Calidad ambiental interior" es un avance conceptual y operativo que supera ampliamente a los anteriores, puesto que orienta las acciones hacia ambientes saludables sin limitar al aire la idea de contaminación. El objetivo del trabajo es identificar las competencias y el marco legislativo que permiten actuar en la prevención de riesgos asociados a la exposición de contaminantes en ambientes interiores. Óptimas condiciones en los ambientes interiores deben redundar en salud, bienestar y confort, tanto en lo que respecta a la vida laboral como a los ámbitos donde se desarrollan las actividades cotidianas extralaborales, escolares, de descanso y de ocio. La sociedad actual exige lugares seguros, limpios y bien climatizados, para lo que es necesario integrar percepciones y exigencias de los habitantes y alcanzar un óptimo equilibrio entre estándares sociales, uso de la energía y desarrollo sostenible, buscando confort sin contaminar y sin aumentar el consumo de fuentes energéticas que degraden el medio ambiente. El desarrollo legislativo se orienta a la seguridad y la salud en los lugares de trabajo y la regulación de las sustancias químicas. La Sanidad Ambiental lleva a cabo tareas de prevención y control, participa en la ejecución de convenios internacionales de reducción de contaminantes y desechos y promueve acciones para el desarrollo de la Estrategia Europea de Salud y Medio Ambiente.

  6. Context Dependent Analysis of BioAmbients

    DEFF Research Database (Denmark)

    Pilegaard, Henrik; Nielson, Flemming; Nielson, Hanne Riis

    2006-01-01

    BioAmbients is a derivative of mobile ambients that has shown promise of describing interesting features of the behaviour of biological systems. The technical contribution of this paper is to extend the Flow Logic approach to static analysis with a couple of new techniques in order to give precise...... information about the behaviour of systems written in BioAmbients. Applying the development to a simple model of a cell releasing nutrients from food compunds we illustrate how the proposed analysis does indeed improve on previous efforts....

  7. Status of ambient air quality at Barauni

    International Nuclear Information System (INIS)

    Kannan, G.K.

    1993-01-01

    Due to industrialization, Barauni has become a well developed industrial estate to be considered as industrial hub of Bihar. Contemporary to the industrial growth, the environmental quality also gradually deteriorated. Hence a need was felt to know the status of ambient air quality for proper planning of the future growth of industries. The ambient air quality was monitored at 16 stations in and around Barauni industrial estate during 3 major seasons for the period of one year. The results are discussed as to the status of the ambient air quality and suggestion have also been made for improvement. (author). 5 refs., 2 figs., 7 tabs

  8. El dispositivo Problemática ambiental

    OpenAIRE

    Federico Di Pasquo; Tomas Busan; Gabriela Klier

    2018-01-01

    Se presenta y problematiza un dispositivo dirigido al tema de la problemática ambiental, del cual destaca su alcance global, su carácter de urgente y su capacidad para afectar a la viabilidad de la especie humana. A la vez, indicamos que esta caracterización de la crisis ambiental se encuentra asociada a una red institucional de corte internacional dirigida a la gestión de este tema. También, se señalan algunos intentos por utilizar a la problemática ambiental como coartada para el establecim...

  9. Diffusive-light invisibility cloak for transient illumination

    Science.gov (United States)

    Orazbayev, B.; Beruete, M.; Martínez, A.; García-Meca, C.

    2016-12-01

    Invisibility in a diffusive-light-scattering medium has been recently demonstrated by employing a scattering-cancellation core-shell cloak. Unlike nondiffusive cloaks, such a device can be simultaneously macroscopic, broadband, passive, polarization independent, and omnidirectional. Unfortunately, it has been verified that this cloak, as well as more sophisticated ones based on transformation optics, fail under pulsed illumination, invalidating their use for a variety of applications. Here, we introduce a different approach based on unimodular transformations that enables the construction of unidirectional diffusive-light cloaks exhibiting a perfect invisibility effect, even under transient conditions. Moreover, we demonstrate that a polygonal cloak can extend this functionality to multiple directions with a nearly ideal behavior, while preserving all other features. We propose and numerically verify a simple cloak realization based on a layered stack of two isotropic materials. The studied devices have several applications not addressable by any of the other cloaks proposed to date, including shielding from pulse-based detection techniques, cloaking undesired scattering elements in time-of-flight imaging or high-speed communication systems for diffusive environments, and building extreme optical security features. The discussed cloaking strategy could also be applied to simplify the implementation of thermal cloaks.

  10. Tip-enhanced Raman mapping with top-illumination AFM.

    Science.gov (United States)

    Chan, K L Andrew; Kazarian, Sergei G

    2011-04-29

    Tip-enhanced Raman mapping is a powerful, emerging technique that offers rich chemical information and high spatial resolution. Currently, most of the successes in tip-enhanced Raman scattering (TERS) measurements are based on the inverted configuration where tips and laser are approaching the sample from opposite sides. This results in the limitation of measurement for transparent samples only. Several approaches have been developed to obtain tip-enhanced Raman mapping in reflection mode, many of which involve certain customisations of the system. We have demonstrated in this work that it is also possible to obtain TERS nano-images using an upright microscope (top-illumination) with a gold-coated Si atomic force microscope (AFM) cantilever without significant modification to the existing integrated AFM/Raman system. A TERS image of a single-walled carbon nanotube has been achieved with a spatial resolution of ∼ 20-50 nm, demonstrating the potential of this technique for studying non-transparent nanoscale materials.

  11. Tip-enhanced Raman mapping with top-illumination AFM

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K L Andrew; Kazarian, Sergei G, E-mail: s.kazarian@imperial.ac.uk [Department of Chemical Engineering, Imperial College London, SW7 2AZ (United Kingdom)

    2011-04-29

    Tip-enhanced Raman mapping is a powerful, emerging technique that offers rich chemical information and high spatial resolution. Currently, most of the successes in tip-enhanced Raman scattering (TERS) measurements are based on the inverted configuration where tips and laser are approaching the sample from opposite sides. This results in the limitation of measurement for transparent samples only. Several approaches have been developed to obtain tip-enhanced Raman mapping in reflection mode, many of which involve certain customisations of the system. We have demonstrated in this work that it is also possible to obtain TERS nano-images using an upright microscope (top-illumination) with a gold-coated Si atomic force microscope (AFM) cantilever without significant modification to the existing integrated AFM/Raman system. A TERS image of a single-walled carbon nanotube has been achieved with a spatial resolution of {approx} 20-50 nm, demonstrating the potential of this technique for studying non-transparent nanoscale materials.

  12. Tip-enhanced Raman mapping with top-illumination AFM

    International Nuclear Information System (INIS)

    Chan, K L Andrew; Kazarian, Sergei G

    2011-01-01

    Tip-enhanced Raman mapping is a powerful, emerging technique that offers rich chemical information and high spatial resolution. Currently, most of the successes in tip-enhanced Raman scattering (TERS) measurements are based on the inverted configuration where tips and laser are approaching the sample from opposite sides. This results in the limitation of measurement for transparent samples only. Several approaches have been developed to obtain tip-enhanced Raman mapping in reflection mode, many of which involve certain customisations of the system. We have demonstrated in this work that it is also possible to obtain TERS nano-images using an upright microscope (top-illumination) with a gold-coated Si atomic force microscope (AFM) cantilever without significant modification to the existing integrated AFM/Raman system. A TERS image of a single-walled carbon nanotube has been achieved with a spatial resolution of ∼ 20-50 nm, demonstrating the potential of this technique for studying non-transparent nanoscale materials.

  13. Illuminating structural proteins in viral "dark matter" with metaproteomics.

    Science.gov (United States)

    Brum, Jennifer R; Ignacio-Espinoza, J Cesar; Kim, Eun-Hae; Trubl, Gareth; Jones, Robert M; Roux, Simon; VerBerkmoes, Nathan C; Rich, Virginia I; Sullivan, Matthew B

    2016-03-01

    Viruses are ecologically important, yet environmental virology is limited by dominance of unannotated genomic sequences representing taxonomic and functional "viral dark matter." Although recent analytical advances are rapidly improving taxonomic annotations, identifying functional dark matter remains problematic. Here, we apply paired metaproteomics and dsDNA-targeted metagenomics to identify 1,875 virion-associated proteins from the ocean. Over one-half of these proteins were newly functionally annotated and represent abundant and widespread viral metagenome-derived protein clusters (PCs). One primarily unannotated PC dominated the dataset, but structural modeling and genomic context identified this PC as a previously unidentified capsid protein from multiple uncultivated tailed virus families. Furthermore, four of the five most abundant PCs in the metaproteome represent capsid proteins containing the HK97-like protein fold previously found in many viruses that infect all three domains of life. The dominance of these proteins within our dataset, as well as their global distribution throughout the world's oceans and seas, supports prior hypotheses that this HK97-like protein fold is the most abundant biological structure on Earth. Together, these culture-independent analyses improve virion-associated protein annotations, facilitate the investigation of proteins within natural viral communities, and offer a high-throughput means of illuminating functional viral dark matter.

  14. Structural and mechanistic studies of measles virus illuminate paramyxovirus entry.

    Directory of Open Access Journals (Sweden)

    Richard K Plemper

    2011-06-01

    Full Text Available Measles virus (MeV, a member of the paramyxovirus family of enveloped RNA viruses and one of the most infectious viral pathogens identified, accounts for major pediatric morbidity and mortality worldwide although coordinated efforts to achieve global measles control are in place. Target cell entry is mediated by two viral envelope glycoproteins, the attachment (H and fusion (F proteins, which form a complex that achieves merger of the envelope with target cell membranes. Despite continually expanding knowledge of the entry strategies employed by enveloped viruses, our molecular insight into the organization of functional paramyxovirus fusion complexes and the mechanisms by which the receptor binding by the attachment protein triggers the required conformational rearrangements of the fusion protein remain incomplete. Recently reported crystal structures of the MeV attachment protein in complex with its cellular receptors CD46 or SLAM and newly developed functional assays have now illuminated some of the fundamental principles that govern cell entry by this archetype member of the paramyxovirus family. Here, we review these advances in our molecular understanding of MeV entry in the context of diverse entry strategies employed by other members of the paramyxovirus family.

  15. Broadband illumination of superconducting pair breaking photon detectors

    International Nuclear Information System (INIS)

    Guruswamy, T; Goldie, D J; Withington, S

    2016-01-01

    Understanding the detailed behaviour of superconducting pair breaking photon detectors such as Kinetic Inductance Detectors (KIDs) requires knowledge of the nonequilibrium quasiparticle energy distributions. We have previously calculated the steady state distributions resulting from uniform absorption of monochromatic sub gap and above gap frequency radiation by thin films. In this work, we use the same methods to calculate the effect of illumination by broadband sources, such as thermal radiation from astrophysical phenomena or from the readout system. Absorption of photons at multiple above gap frequencies is shown to leave unchanged the structure of the quasiparticle energy distribution close to the superconducting gap. Hence for typical absorbed powers, we find the effects of absorption of broadband pair breaking radiation can simply be considered as the sum of the effects of absorption of many monochromatic sources. Distribution averaged quantities, like quasiparticle generation efficiency η, match exactly a weighted average over the bandwidth of the source of calculations assuming a monochromatic source. For sub gap frequencies, however, distributing the absorbed power across multiple frequencies does change the low energy quasiparticle distribution. For moderate and high absorbed powers, this results in a significantly larger η–a higher number of excess quasiparticles for a broadband source compared to a monochromatic source of equal total absorbed power. Typically in KIDs the microwave power absorbed has a very narrow bandwidth, but in devices with broad resonance characteristics (low quality factors), this increase in η may be measurable. (paper)

  16. Detection of Fish Bones in Cod Fillets by UV Illumination.

    Science.gov (United States)

    Wang, Sheng; Nian, Rui; Cao, Limin; Sui, Jianxin; Lin, Hong

    2015-07-01

    The presence of fish bones is now regarded as an important hazard in fishery products, and there is increasing demand for new analytical techniques to control it more effectively. Here, the fluorescent properties of cod bones under UV illumination were investigated, and the maximal wavelengths for excitation and emission were determined to be 320 nm and 515 nm, respectively, demonstrating significantly different fluorescence characteristics and much higher fluorescence intensity compared to those of fillet muscles. Based on the results, UV fluorescence-assisted candling for the detection of bones in fishery products was developed for the first time. Using cod fillets as samples, the detection ratio of this technique was calculated as 90.86%, significantly higher than that of traditional candling under daylight (76.78%). Moreover, the working efficiency of the new technique was about 26% higher than that of the traditional method. A UV fluorescence imaging framework was also developed, and a method for automatic identification of the fish bones in the cod fillets based on the linear discriminant analysis proposed by Fisher was preliminarily realized, but the detection ratio was demonstrated to be relatively poor compared to those of candling techniques. These results allow us to suggest UV-based methods as new and promising approaches for routine monitoring of bones in fishery products.

  17. Sub-nanometer glass surface dynamics induced by illumination

    International Nuclear Information System (INIS)

    Nguyen, Duc; Nienhaus, Lea; Haasch, Richard T.; Lyding, Joseph; Gruebele, Martin

    2015-01-01

    Illumination is known to induce stress and morphology changes in opaque glasses. Amorphous silicon carbide (a-SiC) has a smaller bandgap than the crystal. Thus, we were able to excite with 532 nm light a 1 μm amorphous surface layer on a SiC crystal while recording time-lapse movies of glass surface dynamics by scanning tunneling microscopy (STM). Photoexcitation of the a-SiC surface layer through the transparent crystal avoids heating the STM tip. Up to 6 × 10 4 s, long movies of surface dynamics with 40 s time resolution and sub-nanometer spatial resolution were obtained. Clusters of ca. 3-5 glass forming units diameter are seen to cooperatively hop between two states at the surface. Photoexcitation with green laser light recruits immobile clusters to hop, rather than increasing the rate at which already mobile clusters hop. No significant laser heating was observed. Thus, we favor an athermal mechanism whereby electronic excitation of a-SiC directly controls glassy surface dynamics. This mechanism is supported by an exciton migration-relaxation-thermal diffusion model. Individual clusters take ∼1 h to populate states differently after the light intensity has changed. We believe the surrounding matrix rearranges slowly when it is stressed by a change in laser intensity, and clusters serve as a diagnostic. Such cluster hopping and matrix rearrangement could underlie the microscopic mechanism of photoinduced aging of opaque glasses

  18. On the identification of folium and orchil on illuminated manuscripts.

    Science.gov (United States)

    Aceto, Maurizio; Calà, Elisa; Agostino, Angelo; Fenoglio, Gaia; Idone, Ambra; Porter, Cheryl; Gulmini, Monica

    2017-01-15

    The identification of the two purple dyes folium and orchil has rarely been reported in the analysis of painted artworks, especially when analysing illuminated manuscripts. This is not consistent with the fact that ancient literary sources suggested their use as substitutes for the more expensive Tyrian purple dye. By employing non-invasive spectroscopic techniques, the present work demonstrates that these dyes were actually widely used in the production of ancient manuscripts. By employing UV-visible diffuse reflectance spectrophotometry with optic fibres (FORS) and spectrofluorimetry, the abundant identification of both dyes on medieval manuscripts was performed by comparing the spectra recorded on ancient codices with those obtained on accurate replicas of dyed or painted parchment. Moreover, examples are also reported whereby the considered purple dyes were used in mixtures with other colourants. The overall information obtained here allowed us to define new boundaries for the time range in which orchil and folium dyes were used which is wider than previously thought, and to focus on their particular uses in the decoration of books. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Efficient visibility encoding for dynamic illumination in direct volume rendering.

    Science.gov (United States)

    Kronander, Joel; Jönsson, Daniel; Löw, Joakim; Ljung, Patric; Ynnerman, Anders; Unger, Jonas

    2012-03-01

    We present an algorithm that enables real-time dynamic shading in direct volume rendering using general lighting, including directional lights, point lights, and environment maps. Real-time performance is achieved by encoding local and global volumetric visibility using spherical harmonic (SH) basis functions stored in an efficient multiresolution grid over the extent of the volume. Our method enables high-frequency shadows in the spatial domain, but is limited to a low-frequency approximation of visibility and illumination in the angular domain. In a first pass, level of detail (LOD) selection in the grid is based on the current transfer function setting. This enables rapid online computation and SH projection of the local spherical distribution of visibility information. Using a piecewise integration of the SH coefficients over the local regions, the global visibility within the volume is then computed. By representing the light sources using their SH projections, the integral over lighting, visibility, and isotropic phase functions can be efficiently computed during rendering. The utility of our method is demonstrated in several examples showing the generality and interactive performance of the approach.

  20. Fast Fourier single-pixel imaging via binary illumination.

    Science.gov (United States)

    Zhang, Zibang; Wang, Xueying; Zheng, Guoan; Zhong, Jingang

    2017-09-20

    Fourier single-pixel imaging (FSI) employs Fourier basis patterns for encoding spatial information and is capable of reconstructing high-quality two-dimensional and three-dimensional images. Fourier-domain sparsity in natural scenes allows FSI to recover sharp images from undersampled data. The original FSI demonstration, however, requires grayscale Fourier basis patterns for illumination. This requirement imposes a limitation on the imaging speed as digital micro-mirror devices (DMDs) generate grayscale patterns at a low refreshing rate. In this paper, we report a new strategy to increase the speed of FSI by two orders of magnitude. In this strategy, we binarize the Fourier basis patterns based on upsampling and error diffusion dithering. We demonstrate a 20,000 Hz projection rate using a DMD and capture 256-by-256-pixel dynamic scenes at a speed of 10 frames per second. The reported technique substantially accelerates image acquisition speed of FSI. It may find broad imaging applications at wavebands that are not accessible using conventional two-dimensional image sensors.

  1. Multiobjective generalized extremal optimization algorithm for simulation of daylight illuminants

    Science.gov (United States)

    Kumar, Srividya Ravindra; Kurian, Ciji Pearl; Gomes-Borges, Marcos Eduardo

    2017-10-01

    Daylight illuminants are widely used as references for color quality testing and optical vision testing applications. Presently used daylight simulators make use of fluorescent bulbs that are not tunable and occupy more space inside the quality testing chambers. By designing a spectrally tunable LED light source with an optimal number of LEDs, cost, space, and energy can be saved. This paper describes an application of the generalized extremal optimization (GEO) algorithm for selection of the appropriate quantity and quality of LEDs that compose the light source. The multiobjective approach of this algorithm tries to get the best spectral simulation with minimum fitness error toward the target spectrum, correlated color temperature (CCT) the same as the target spectrum, high color rendering index (CRI), and luminous flux as required for testing applications. GEO is a global search algorithm based on phenomena of natural evolution and is especially designed to be used in complex optimization problems. Several simulations have been conducted to validate the performance of the algorithm. The methodology applied to model the LEDs, together with the theoretical basis for CCT and CRI calculation, is presented in this paper. A comparative result analysis of M-GEO evolutionary algorithm with the Levenberg-Marquardt conventional deterministic algorithm is also presented.

  2. Ambient air pollution and thrombosis.

    Science.gov (United States)

    Robertson, Sarah; Miller, Mark R

    2018-01-03

    Air pollution is a growing public health concern of global significance. Acute and chronic exposure is known to impair cardiovascular function, exacerbate disease and increase cardiovascular mortality. Several plausible biological mechanisms have been proposed for these associations, however, at present, the pathways are incomplete. A seminal review by the American Heart Association (2010) concluded that the thrombotic effects of particulate air pollution likely contributed to their effects on cardiovascular mortality and morbidity. The aim of the current review is to appraise the newly accumulated scientific evidence (2009-2016) on contribution of haemostasis and thrombosis towards cardiovascular disease induced by exposure to both particulate and gaseous pollutants.Seventy four publications were reviewed in-depth. The weight of evidence suggests that acute exposure to fine particulate matter (PM 2.5 ) induces a shift in the haemostatic balance towards a pro-thrombotic/pro-coagulative state. Insufficient data was available to ascertain if a similar relationship exists for gaseous pollutants, and very few studies have addressed long-term exposure to ambient air pollution. Platelet activation, oxidative stress, interplay between interleukin-6 and tissue factor, all appear to be potentially important mechanisms in pollution-mediated thrombosis, together with an emerging role for circulating microvesicles and epigenetic changes.Overall, the recent literature supports, and arguably strengthens, the contention that air pollution contributes to cardiovascular morbidity by promoting haemostasis. The volume and diversity of the evidence highlights the complexity of the pathophysiologic mechanisms by which air pollution promotes thrombosis; multiple pathways are plausible and it is most likely they act in concert. Future research should address the role gaseous pollutants play in the cardiovascular effects of air pollution mixture and direct comparison of potentially

  3. The Utility of the Extended Images in Ambient Seismic Wavefield Migration

    Science.gov (United States)

    Girard, A. J.; Shragge, J. C.

    2015-12-01

    Active-source 3D seismic migration and migration velocity analysis (MVA) are robust and highly used methods for imaging Earth structure. One class of migration methods uses extended images constructed by incorporating spatial and/or temporal wavefield correlation lags to the imaging conditions. These extended images allow users to directly assess whether images focus better with different parameters, which leads to MVA techniques that are based on the tenets of adjoint-state theory. Under certain conditions (e.g., geographical, cultural or financial), however, active-source methods can prove impractical. Utilizing ambient seismic energy that naturally propagates through the Earth is an alternate method currently used in the scientific community. Thus, an open question is whether extended images are similarly useful for ambient seismic migration processing and verifying subsurface velocity models, and whether one can similarly apply adjoint-state methods to perform ambient migration velocity analysis (AMVA). Herein, we conduct a number of numerical experiments that construct extended images from ambient seismic recordings. We demonstrate that, similar to active-source methods, there is a sensitivity to velocity in ambient seismic recordings in the migrated extended image domain. In synthetic ambient imaging tests with varying degrees of error introduced to the velocity model, the extended images are sensitive to velocity model errors. To determine the extent of this sensitivity, we utilize acoustic wave-equation propagation and cross-correlation-based migration methods to image weak body-wave signals present in the recordings. Importantly, we have also observed scenarios where non-zero correlation lags show signal while zero-lags show none. This may be a valuable missing piece for ambient migration techniques that have yielded largely inconclusive results, and might be an important piece of information for performing AMVA from ambient seismic recordings.

  4. Investigating the use of an adjustment task to set preferred illuminances in a workplace environment

    DEFF Research Database (Denmark)

    Logadóttir, Ásta; Christoffersen, Jens; Fotios, Steve

    2011-01-01

    An experiment was carried out to examine user preferences for light level using the method of adjustment. The study sought preferred illuminances under lighting from fluorescent lamps of different correlated colour temperature. It was hypothesised that the preferred illuminance would be influenced...

  5. Joint illumination and visible-light communication systems : data rates and extra power consumption

    NARCIS (Netherlands)

    Tsiatmas, Anagnostis; Willems, Frans; Linnartz, Jean-Paul; Baggen, C.P.M.J.; Bergmans, Jan

    2015-01-01

    Visible Light Communications (VLC) have been promoted as an energy-efficient Gb/s-technology for indoor settings, since VLC can be merged with the illumination functionality. As a result, Joint Illumination and visible-light Communication (JIC) systems are perceived as a green technology and the

  6. Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates.

    Science.gov (United States)

    Acker, Leah C; Pino, Erica N; Boyden, Edward S; Desimone, Robert

    2017-10-03

    This protocol describes a large-volume illuminator, which was developed for optogenetic manipulations in the non-human primate brain. The illuminator is a modified plastic optical fiber with etched tip, such that the light emitting surface area is > 100x that of a conventional fiber. In addition to describing the construction of the large-volume illuminator, this protocol details the quality-control calibration used to ensure even light distribution. Further, this protocol describes techniques for inserting and removing the large volume illuminator. Both superficial and deep structures may be illuminated. This large volume illuminator does not need to be physically coupled to an electrode, and because the illuminator is made of plastic, not glass, it will simply bend in circumstances when traditional optical fibers would shatter. Because this illuminator delivers light over behaviorally-relevant tissue volumes (≈ 10 mm 3 ) with no greater penetration damage than a conventional optical fiber, it facilitates behavioral studies using optogenetics in non-human primates.

  7. [An assembly line lighting survey analysis and its optimal illumination range research].

    Science.gov (United States)

    Yang, Xin-ning; Xu, Yan; DU, Wei-wei; Cao, Lei; Wang, Sheng; Dong, Xue-mei; Lu, Hou-han; Chen, Song-gen; Cao, Xiao-ou; Zhang, Long-lian; He, Li-hua

    2011-06-18

    To investigate and analyze present conditions of the assembling line illumination in our country, and to set the recommended values of illuminance standard. Questionnaires and field surveys were used in this investigation. A total of 752 workers from seven factories in textile, shoes and electronics industries were selected for the questionnaire survey and site measurement, and corresponding analyses made with SPSS 13.0 statistic software. Uniformity of illumination, definition in working face, general satisfactory degrees, asthenopia were significantly correlated with each other. Assembly line illuminances for five different visual characteristics were recommended in this paper. The illuminances were 500-1 000-1 500 lx, 300-500-1 000 lx, 200-300-750 lx, 100-300-500 lx, 50-100-200 lx, respectively. Present conditions of the assembling line illumination are less than satisfactory, uniformity of illumination is on the low side, and there is no assembling line illuminance standard for general satisfactory degrees and asthenopia of workers. The related work should be further improved.

  8. An internally illuminated monolith reactor: Pros and cons relative to a slurry reactor

    NARCIS (Netherlands)

    Carneiro, Joana T.; Carneiro, J.T.; Berger, Rob; Moulijn, Jacob A.; Mul, Guido

    2009-01-01

    In the present study, kinetic models for the photo-oxidation of cyclohexane in two different photoreactor systems are discussed: a top illumination reactor (TIR) representative of a slurry reactor, and the so-called internally illuminated monolith reactor (IIMR) representing a reactor containing

  9. Uniform illumination rendering using an array of LEDs: a signal processing perspective

    NARCIS (Netherlands)

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.; Linnartz, J.P.M.G.; Rietman, R.

    2009-01-01

    An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic

  10. Illumination sensing in LED lighting systems based on frequency-division multiplexing

    NARCIS (Netherlands)

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.

    2009-01-01

    Recently, light emitting diode (LED) based illumination systems have attracted considerable research interest. Such systems normally consist of a large number of LEDs. In order to facilitate the control of such high-complexity system, a novel signal processing application, namely illumination

  11. The Illumination Model of the Valley Based on the Diffuse Reflect of Forest

    Directory of Open Access Journals (Sweden)

    He Guoliang

    2016-01-01

    Full Text Available In this paper, models are build to evaluate the impact of the forest on the valley’s illumination. Based on the assumes that all the light reach the ground comes from the diffuse reflection which comes from the sun directly and from the diffuse reflection of other points, One model is build to consider the impact of time and latitude on the direction of the sunlight. So we can get the direction of the sunlight at different time and latitude through the model. Besides, this paper develops a illumination model to evaluate the intensity of illumination of the ground. Combining the models above, this paper get a complete model which can not only evaluate the overall light intensity of the valley but also convert the light intensity to the intensity of illumination. Simulation of the intensity illumination of some basic terrains and finally gives a comprehensive results which is practical and close to the common sense.

  12. Measuring object shape by using in-plane electronic speckle pattern interferometry with divergent illumination

    International Nuclear Information System (INIS)

    Parra-Michel, Jorge; Martínez, Amalia; Rayas, J A; Anguiano-Morales, Marcelino

    2010-01-01

    Electronic speckle pattern interferometry is a useful technique for displacement, deformation and contouring measurements. Traditionally, for contouring measurements, collimated illumination with a constant sensitivity vector is used, and the surface area analysis is limited to the illuminated area. In some industrial applications, large surfaces require to be analyzed in restricted space conditions. Considering this situation, an optical system with divergent illumination for whole-field measurements can be used. It is known that displacement fields and the optical phase are related by the sensitivity vector. Therefore, to compute the sensitivity vector, illumination position and superficial shape need to be considered, a condition that becomes an impediment for surface contouring if the superficial shape is unknown. In this work, a simple iterative algorithm based on the Gauss–Seidel technique is presented to compute contouring measurements. Contouring measurements from both ESPI and a coordinate-measuring machine (CMM) are compared. In addition, a measurement comparison considering supposed collimated and divergent illumination is presented

  13. Feasibility Study on Passive-radar Detection of Space Targets Using Spaceborne Illuminators of Opportunity

    Directory of Open Access Journals (Sweden)

    Jiang Tie-zhen

    2015-01-01

    Full Text Available Space target surveillance generally uses active radars. To take full advantage of passive radars, the idea of using spaceborne illuminators of opportunity for space target detection is presented in this paper. Analysis of the detectable time and direct wave suppression shows that passive radar using spaceborne illuminators of opportunity can effectively detect a Low-Earth-Orbit (LEO target. Meanwhile, Ku and L band bi-static radar cross section of passive radars that use spaceborne illuminators of opportunity are presented by simulation, providing the basis of choosing space target forward scatter. Finally the key parameters, mainly system gain, accumulation time and radiation source selection are studied. Results show that system size using satellite TV signals as illuminators of opportunity is relatively small. These encouraging results should stimulate the development of passive radar detection of space targets using spaceborne illuminators of opportunity.

  14. Estimation of luminous efficacy of daylight and illuminance for composite climate

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Jamil M.; Tiwari, G.N. [Center for Energy Studies, Indian Institute of Technology, Hauz Khas, New Delhi-16 (India)

    2010-07-01

    This Daylighting is one of the basic components of passive solar building design and its estimation is essential. In India there are a few available data of measured illuminance as in many regions of the world. The Indian climate is generally clear with overcast conditions prevailing through the months of July to September, which provides good potential to daylighting in buildings. Therefore, an analytical model that would encompass the weather conditions of New Delhi was selected. Hourly exterior horizontal and slope daylight availability has been estimated for New Delhi using daylight modeling techniques based on solar radiation data. A model to estimate interior illuminance was investigated and validated using experimental hourly inside illuminance data of an existing skylight integrated vault roof mud house in composite climate of New Delhi. The interior illuminance model was found in good agreement with experimental value of interior illuminance.

  15. Verification of simple illuminance based measures for indication of discomfort glare from windows

    DEFF Research Database (Denmark)

    Karlsen, Line Røseth; Heiselberg, Per Kvols; Bryn, Ida

    2015-01-01

    predictions of discomfort glare from windows already in the early design stage when decisions regarding the façade are taken. This study focus on verifying if simple illuminance based measures like vertical illuminance at eye level or horizontal illuminance at the desk are correlated with the perceived glare...... reported by 44 test subjects in a repeated measure design occupant survey and if the reported glare corresponds with the predictions from the simple Daylight Glare Probability (DGPs) model. Large individual variations were seen in the occupants’ assessment of glare in the present study. Yet, the results...... confirm that there is a statistically significant correlation between both vertical eye illuminance and horizontal illuminance at the desk and the occupants’ perception of glare in a perimeter zone office environment, which is promising evidence towards utilizing such simple measures for indication...

  16. Hybrid daylight/light-emitting diode illumination system for indoor lighting.

    Science.gov (United States)

    Ge, Aiming; Qiu, Peng; Cai, Jinlin; Wang, Wei; Wang, Junwei

    2014-03-20

    A hybrid illumination method using both daylight and light-emitting diodes (LEDs) for indoor lighting is presented in this study. The daylight can be introduced into the indoor space by a panel-integration system. The daylight part and LEDs are combined within a specific luminaire that can provide uniform illumination. The LEDs can be turned on and dimmed through closed-loop control when the daylight illuminance is inadequate. We simulated the illumination and calculated the indoor lighting efficiency of our hybrid daylight and LED lighting system, and compared this with that of LED and fluorescent lighting systems. Simulation results show that the efficiency of the hybrid daylight/LED illumination method is better than that of LED and traditional lighting systems, under the same lighting conditions and lighting time; the method has hybrid lighting average energy savings of T5 66.28%, and that of the LEDs is 41.62%.

  17. Economía y medio ambiente

    Directory of Open Access Journals (Sweden)

    Ciro Alfonso Serna Mendoza

    2010-12-01

    Full Text Available En ciertos escenarios académicos, políticos, sociales y ambientales se declara que el modelo económico dominante o los conceptos que lo integran son responsables de que el bienestar económico implique malestar ecológico.Al partir de este supuesto, una forma de comprender las causas y de contribuir a la solución de la problemática ambiental es develar en qué consisten, en qué términos plantean la relación ombre-medio ambiente, las propuestas que incluyen la dimensión ambiental en el campo de la economía. Y si, al igual que las teorías ambientales, acuden a la ética como factor adecuado para disminuir las externalidades negativas generadas en el ambiente por la actividad económica.

  18. Games and Entertainment in Ambient Intelligence Environments

    NARCIS (Netherlands)

    Nijholt, Antinus; Reidsma, Dennis; Poppe, Ronald Walter; Aghajan, H.; López-Cózar Delgado, R.; Augusto, J.C.

    2009-01-01

    In future ambient intelligence (AmI) environments we assume intelligence embedded in the environment and its objects (floors, furniture, mobile robots). These environments support their human inhabitants in their activities and interactions by perceiving them through sensors (proximity sensors,

  19. 2011 NATA - Risks and Annual Ambient Concentrations

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset includes the modeled annual ambient concentrations and risks at the census tract level for the 2011 National Air Toxics Assessment. All concentrations...

  20. Disinfection Alternatives for Small Communities in Puerto Rico

    Science.gov (United States)

    Disinfection Alternatives for Small Communities in Puerto Rico Craig Patterson1, Graciela Ramirez Toro2, Harvey Minnigh2, Cristina Maldonado3, and Rajib Sinha4 1U.S. EPA Office of Research and Development, 2Centro de Educación, Conservación e Interpretación Ambiental (CECIA),...

  1. Patterning 45nm flash/DRAM contact hole mask with hyper-NA immersion lithography and optimized illumination

    Science.gov (United States)

    Chen, Ting; Van Den Broeke, Doug; Hsu, Stephen; Park, Sangbong; Berger, Gabriel; Coskun, Tamer; de Vocht, Joep; Corcoran, Noel; Chen, Fung; van der Heijden, Eddy; Finders, Jo; Engelen, Andre; Socha, Robert

    2006-03-01

    Patterning contact-hole mask for Flash/DRAM is probably one of the most challenging tasks for design rule below 50nm due to the extreme low-k I printing conditions common in the memory designs. When combined with optical proximity corrections (OPC) to the mask, using optimized illumination has become a viable part of the production lithography process for 65nm node. At k Ipitch design rules. Here we use 6% attPSM mask for simulation and actual exposure in ASML XT 1400i (NA=0.93) and 1700i (NA=1.2) respectively. We begin with the illumination source optimization using full vector high-NA calculation (VHNA) with production resist stack and all manufacturability requirements for the source shaping diffractive optical element (DOE) are accounted for during the source optimization. Using the optimized source, IML TM technology based scattering bars (SB) placement together with model based OPC (MOPC) are applied to the original contact-hole design. In-focus printing and process latitude simulations are used to gauge the performance and manufacturability of the final optimized process, which includes the optimized mask, optimized source and required imaging settings. Our results show that for the 130nm pitch Flash contact-hole patterns, on ASML XT 1400i at NA=0.93, both optimized illumination source and immersion lithography are necessary in order to achieve manufacturability. The worst-case depth of focus (DOF) before SB and MOPC is 100-130nm at 6% EL, without common process window (PW) and with MOPC, the worst-case DOF is >200nm at 6% EL. The latter is in excellent agreement with the wafer results from ASML XT 1400i, and the predicated CDs match well with the measured at isolated, medium and dense pitch contact-holes to within 5nm. For the 120nm pitch Flash contact patterns, ASML XT 1700i at NA=1.2 must be used, together with optimized illumination source, to achieve the same or better process latitude (worst-case DOF at 6% EL), and for the Flash pattern used, further

  2. A Smart Kitchen for Ambient Assisted Living

    OpenAIRE

    Blasco, Rubén; Marco, Álvaro; Casas, Roberto; Cirujano, Diego; Picking, Richard

    2014-01-01

    The kitchen environment is one of the scenarios in the home where users can benefit from Ambient Assisted Living (AAL) applications. Moreover, it is the place where old people suffer from most domestic injuries. This paper presents a novel design, implementation and assessment of a Smart Kitchen which provides Ambient Assisted Living services; a smart environment that increases elderly and disabled people’s autonomy in their kitchen-related activities through context and user awareness, appr...

  3. Unidades de Pediatría Ambiental

    OpenAIRE

    PARÍS M, ENRIQUE; MOLINA M, HELIA; RÍOS B, JUAN CARLOS

    2007-01-01

    Se considera que una Unidad de Pediatría Ambiental es una estructura con roles claramente definidos, situada preferentemente en un centro de salud, especializada en afecciones pediátricas, relacionadas al ambiente. Estos centros pueden proporcionar asesoramiento, información y tratamiento, promover la investigación, entrenar a profesionales, educar al público e informar a las autoridades responsables. Su personal, especialmente entrenado en problemas ambientales, incluye: pediatras, toxicólog...

  4. Automatic illumination compensation device based on a photoelectrochemical biofuel cell driven by visible light

    Science.gov (United States)

    Yu, You; Han, Yanchao; Xu, Miao; Zhang, Lingling; Dong, Shaojun

    2016-04-01

    Inverted illumination compensation is important in energy-saving projects, artificial photosynthesis and some forms of agriculture, such as hydroponics. However, only a few illumination adjustments based on self-powered biodetectors that quantitatively detect the intensity of visible light have been reported. We constructed an automatic illumination compensation device based on a photoelectrochemical biofuel cell (PBFC) driven by visible light. The PBFC consisted of a glucose dehydrogenase modified bioanode and a p-type semiconductor cuprous oxide photocathode. The PBFC had a high power output of 161.4 μW cm-2 and an open circuit potential that responded rapidly to visible light. It adjusted the amount of illumination inversely irrespective of how the external illumination was changed. This rational design of utilizing PBFCs provides new insights into automatic light adjustable devices and may be of benefit to intelligent applications.Inverted illumination compensation is important in energy-saving projects, artificial photosynthesis and some forms of agriculture, such as hydroponics. However, only a few illumination adjustments based on self-powered biodetectors that quantitatively detect the intensity of visible light have been reported. We constructed an automatic illumination compensation device based on a photoelectrochemical biofuel cell (PBFC) driven by visible light. The PBFC consisted of a glucose dehydrogenase modified bioanode and a p-type semiconductor cuprous oxide photocathode. The PBFC had a high power output of 161.4 μW cm-2 and an open circuit potential that responded rapidly to visible light. It adjusted the amount of illumination inversely irrespective of how the external illumination was changed. This rational design of utilizing PBFCs provides new insights into automatic light adjustable devices and may be of benefit to intelligent applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00759g

  5. The use of holographic and diffractive optics for optimized machine vision illumination for critical dimension inspection

    Science.gov (United States)

    Lizotte, Todd E.; Ohar, Orest

    2004-02-01

    Illuminators used in machine vision applications typically produce non-uniform illumination onto the targeted surface being observed, causing a variety of problems with machine vision alignment or measurement. In most circumstances the light source is broad spectrum, leading to further problems with image quality when viewed through a CCD camera. Configured with a simple light bulb and a mirrored reflector and/or frosted glass plates, these general illuminators are appropriate for only macro applications. Over the last 5 years newer illuminators have hit the market including circular or rectangular arrays of high intensity light emitting diodes. These diode arrays are used to create monochromatic flood illumination of a surface that is to be inspected. The problem with these illumination techniques is that most of the light does not illuminate the desired areas, but broadly spreads across the surface, or when integrated with diffuser elements, tend to create similar shadowing effects to the broad spectrum light sources. In many cases a user will try to increase the performance of these illuminators by adding several of these assemblies together, increasing the intensity or by moving the illumination source closer or farther from the surface being inspected. In this case these non-uniform techniques can lead to machine vision errors, where the computer machine vision may read false information, such as interpreting non-uniform lighting or shadowing effects as defects. This paper will cover a technique involving the use of holographic / diffractive hybrid optical elements that are integrated into standard and customized light sources used in the machine vision industry. The bulk of the paper will describe the function and fabrication of the holographic/diffractive optics and how they can be tailored to improve illuminator design. Further information will be provided a specific design and examples of it in operation will be disclosed.

  6. Ambient ionization mass spectrometry: A tutorial

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Shiea, Jentaie, E-mail: jetea@fac.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan (China); Cancer Center, Kaohsiung Medical University, Kaohsiung, Taiwan (China)

    2011-09-19

    Highlights: {yields} Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. {yields} We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. {yields} The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.

  7. Ambient ionization mass spectrometry: A tutorial

    International Nuclear Information System (INIS)

    Huang, Min-Zong; Cheng, Sy-Chi; Cho, Yi-Tzu; Shiea, Jentaie

    2011-01-01

    Highlights: → Ambient ionization technique allows the direct analysis of sample surfaces with little or no sample pretreatment. → We sort ambient ionization techniques into three main analytical strategies, direct ionization, direct desorption/ionization, and two-step ionization. → The underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques are described and compared. - Abstract: Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food safety screening; detection of pharmaceuticals and drug abuse; monitoring of environmental pollutants; detection of explosives for antiterrorism and forensics; characterization of biological compounds for proteomics and metabolomics; molecular imaging analysis; and monitoring chemical and biochemical reactions). Electrospray ionization and atmospheric pressure chemical ionization are the two main ionization principles most commonly used in ambient ionization mass spectrometry. This tutorial paper provides a review of the publications related to ambient ionization techniques. We describe and compare the underlying principles of operation, ionization processes, detecting mass ranges, sensitivity, and representative applications of these techniques.

  8. Biotecnologia Ambiental. Aplicacions biotecnològiques a la millora del medi ambient

    OpenAIRE

    Blanch i Gisbert, Anicet

    2010-01-01

    La biotecnología ambiental comprende el conjunto de actividades tecnológicas que facilitan la comprensión y la gestión de los sistemas biológicos en el medio ambiente, con el fin de proveer productos y servicios. Actualmente, la gestión del medio ambiente y de sus recursos naturales no se comprende si no se realiza de manera sostenible. Los avances científicos y tecnológicos le están permitiendo a la biotecnología ambiental, el desarrollo de nuevas herramientas y aplicaciones con los que resp...

  9. Towards New Ambient Light Systems: a Close Look at Existing Encodings of Ambient Light Systems

    Directory of Open Access Journals (Sweden)

    Andrii Matviienko

    2015-10-01

    Full Text Available Ambient systems provide information in the periphery of a user’s attention. Their aim is to present information as unobtrusively as possible to avoid interrupting primary tasks (e.g. writing or reading. In recent years, light has been used to create ambient systems to display information. Examples of ambient light systems range from simple notification systems such as displaying messages or calendar event reminders, to more complex systems such as focusing on conveying information regarding health activity tracking. However, for ambient light systems, there is a broad design space that lacks guidelines on when to make use of light displays and how to design them. In this paper we provide a systematic overview of existing ambient light systems over four identified information classes derived from 72 existing ambient light systems. The most prominent encoding parameters among the surveyed ambient light systems are color, brightness, and their combination. By analyzing existing ambient light systems, we provide a first step towards developing guidelines for designing future ambient light systems.

  10. LEDs Illuminate Bulbs for Better Sleep, Wake Cycles

    Science.gov (United States)

    2015-01-01

    Life on the International Space Station (ISS) wreaks havoc on an astronaut’s biological rhythms, and one way NASA mitigates the problem is through the use of LED lighting to alternately stimulate energy and focus and induce relaxation. Satellite Beach, Florida-based Lighting Science partnered with Kennedy Space Center to commercialize an LED system designed for the ISS, resulting in its DefinityDigital product line of light bulbs now used in numerous homes, hotel chains, and resorts.

  11. The Whiteboard Revolution: Illuminating Science Communication in the Digital Age.

    Science.gov (United States)

    Mar, Florie Anne; Ordovas-Montanes, Jose; Oksenberg, Nir; Olson, Alexander M

    2016-04-01

    Journal-based science communication is not accessible or comprehensible to a general public curious about science and eager for the next wave of scientific innovation. We propose an alternative medium for scientists to communicate their work to the general public in an engaging and digestible way through the use of whiteboard videos. We describe the process of producing science whiteboard videos and the benefits and challenges therein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Ambient vibrations of unstable rock slopes - insights from numerical modeling

    Science.gov (United States)

    Burjanek, Jan; Kleinbrod, Ulrike; Fäh, Donat

    2017-04-01

    The recent events in Nepal (2015 M7.8 Gorkha) and New Zealand (2016 M7.8 Kaikoura) highlighted the importance of earthquake-induced landslides, which caused significant damages. Moreover, landslide created dams present a potential developing hazard. In order to reduce the costly consequences of such events it is important to detect and characterize earthquake susceptible rock slope instabilities before an event, and to take mitigation measures. For the characterisation of instable slopes, acquisition of ambient vibrations might be a new alternative to the already existing methods. We present both observations and 3D numerical simulations of the ambient vibrations of unstable slopes. In particular, models of representative real sites have been developed based on detailed terrain mapping and used for the comparison between synthetics and observations. A finite-difference code has been adopted for the seismic wave propagation in a 3D inhomogeneous visco-elastic media with irregular free surface. It utilizes a curvilinear grid for a precise modeling of curved topography and local mesh refinement to make computational mesh finer near the free surface. Topographic site effects, controlled merely by the shape of the topography, do not explain the observed seismic response. In contrast, steeply-dipping compliant fractures have been found to play a key role in fitting observations. Notably, the synthetized response is controlled by inertial mass of the unstable rock, and by stiffness, depth and network density of the fractures. The developed models fit observed extreme amplification levels (factors of 70!) and show directionality as well. This represents a possibility to characterize slope structure and infer depth or volume of the slope instability from the ambient noise recordings in the future.

  13. Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems.

    Science.gov (United States)

    Cionni, Robert J; Pei, Ron; Dimalanta, Ramon; Lubeck, David

    2015-08-01

    To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery.

  14. Quantitative analysis of negative bias illumination stress-induced instability mechanisms in amorphous InGaZnO thin-film transistors

    International Nuclear Information System (INIS)

    Kim, Yong Sik; Bae, Min Kyung; Kong, Dong Sik; Jung, Hyun Kwang; Kim, Jae Hyeong; Kim, Woo Joon; Hur, In Seok; Kim, Dong Myong; Kim, Dae Hwan

    2011-01-01

    The physical origins of the negative bias illumination stress (NBIS)-induced threshold voltage shift (ΔV T ) in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) under ambient light from a backlight unit are quantitatively and systematically investigated. Furthermore, a methodology for extracting the instability parameters is proposed and demonstrated. For the quantitative analysis, the subgap density-of-states (DOS)-based DC I-V model is intensively used. The NBIS time-evolution of the measured I DS -V GS characteristics is reproduced very well via the proposed methodology and instability parameters. Consequently, photo-excited electron detrapping, followed by ionization of oxygen vacancies (V O +2 ) and field-enhanced V O +2 diffusion, followed by hole trapping into the gate insulator, are found to be the dominant mechanisms in NBIS-induced instability of a-IGZO TFTs.

  15. Agroenergy production from biomass in integrated agroforestry systems: an alternative to achieve food security and environmental protection; Producción de agroenergía a partir de biomasa en sistemas agroforestales integrados: una alternativa para lograr la seguridad alimentaria y la protección ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Suárez, J.; Martín, G. J., E-mail: jesus.suarez@indio.atenas.inf.cu [Estación Experimental de Pastos y Forrajes «Indio Hatuey» Central España Republicana, CP 44280, Matanzas (Cuba)

    2010-07-01

    The objective of this paper is to offer considerations about agroenergy production from biomass in integrated agroforestry systems. At present, worldwide, marked by a group of hazards that threaten human existence, there is a challenge mainly in the rural context: how can the coexistence of agroenergy, food security and environmental protection be achieved?, in the presence of climate changes, environmental degradation, food crises and the growing biofuels vs food contradiction, generated by a senseless policy for obtaining first-generation agrofuels from large extensions of food monocrops, which is morally rejectable. Biofuels are also considered an ecological alternative to fossil fuels, because of their reduction capacity in the emission of greenhouse gasses and because they promote the development of rural communities in southern countries; this is enhanced in integrated agroforestry systems, in which biofuels, of first as well as second generation, can be produced, especially with the application of the concept of biorefinery which allows converting biomass into many products, which total added value can be higher than the one generated by fossil fuels. International projects, which promote integrated and sustainable food and energy production in the context of agroforestry integrated systems, at local scale, contribute to this purpose. The authors consider that the execution of projects and experiences about agroenergy has the main objective of achieving energetic sustainability and food security at local scale, in rural areas, taking into account environmental protection. (author)

  16. Alternate superior Julia sets

    International Nuclear Information System (INIS)

    Yadav, Anju; Rani, Mamta

    2015-01-01

    Alternate Julia sets have been studied in Picard iterative procedures. The purpose of this paper is to study the quadratic and cubic maps using superior iterates to obtain Julia sets with different alternate structures. Analytically, graphically and computationally it has been shown that alternate superior Julia sets can be connected, disconnected and totally disconnected, and also fattier than the corresponding alternate Julia sets. A few examples have been studied by applying different type of alternate structures

  17. A novel approach to painting powered by Ambient Intelligence

    Directory of Open Access Journals (Sweden)

    N. Partarakis

    2016-04-01

    Full Text Available Today, many forms of art are influenced by the emergence of interactive technologies, including the mixing of physical media with digital technology for forming new hybrid works of art and the usage of mobile phones to create art projected on public spaces. Many artists and painters use digital technology to augment their work creatively and technically. Many believe that the time of transition from traditional analogue art to postmodern digital art that is, to an art grounded in codes rather than images has arrived*. The research work described in this paper contributes towards supporting, through the use of Ambient Intelligence technologies, traditional painters’ creativity, as well as methods and techniques of art masters. The paper presents the design, implementation and evaluation of an intelligent environment and its software infrastructure, to form a digitally augmented Art Workshop. Its practical deployment was conducted in an Ambient Intelligence (AmI simulation space and four feasibility studies were conducted. In each of these studies an oil painting was created following an alternative, yet accredited by artists, approach. The workshop was also evaluated with the involvement of real users and artists in the context of a user based usability study.

  18. La protección internacional del medio ambiente

    OpenAIRE

    Bou Franch, Valentín

    2017-01-01

    PowerPoint del Tema 14 de la asignatura "Derecho Internacional Público". Curso 2017-18. Tema 14. La protección internacional del medio ambiente: 1.- El Derecho Internacional del Medio Ambiente: caracteres específicos. 2.- Principios fundamentales del Derecho Internacional del Medio Ambiente. 3.- Medio ambiente y Desarrollo: el Desarrollo Sostenible.

  19. Padua and the Stars: Medieval Painting and Illuminated Manuscripts

    Science.gov (United States)

    Canova, G. M.

    2011-06-01

    In the Middle Ages, the University of Padua was one of the most prominent centre for astrological studies in Europe. The Paduan doctor and philosopher, Pietro d'Abano, who lived in the first decades of the 14th century, was the main figure in this field. At the end of the 13th century, during a long stay in Paris, he got in contact with the new astrological doctrines flourished after the translation into Latin of Ptolemy's and Arab's works in Spain. Thus, when he went back to Padua, he published several studies on the influence of celestial bodies on human life and human physical characteristics and psychology. These ideas deeply affected the Paduan society of the 14th century and, consequently, the most important painters chose or were asked to evoke the images of stars, planets, and their properties. This adventure began with Giotto who shows a surprising interest in celestial bodies in the Scrovegni Chapel where he represented a comet, and soon after he produced a cycle of astrological paintings on the vault of the Palazzo della Ragione in the Public Palace of Padua. Unfortunately, in 1420, these paintings were destroyed in a fire, but the magnificent cycle of astrological frescoes realized soon after on the walls of the same room gives us some clues on Giotto's work and shows us the complexity of the Medieval astrological science. Other astrological paintings, still preserved, were realized by the painters of the Carrarese Court such as Guariento, who painted the planets and their influences on human ages in the church of the Eremitani, and Giusto dei Menabuoi who represented a superb zodiac around a realistic map of Earth in the Cathedral Baptistery. So Padua really became the capital of astrological painting in Europe. Other evidence of the astrological image in the Veneto Region, between the 14th and 15th centuries, can be found in the manuscripts illuminated in the milieu of the University of Padua and in the first books printed in Venice.

  20. Measurement of lateral charge diffusion in thick, fully depleted, back-illuminated CCDs

    Energy Technology Data Exchange (ETDEWEB)

    Karcher, Armin; Bebek, Christopher J.; Kolbe, William F.; Maurath, Dominic; Prasad, Valmiki; Uslenghi, Michela; Wagner, Martin

    2004-06-30

    Lateral charge diffusion in back-illuminated CCDs directly affects the point spread function (PSF) and spatial resolution of an imaging device. This can be of particular concern in thick, back-illuminated CCDs. We describe a technique of measuring this diffusion and present PSF measurements for an 800 x 1100, 15 mu m pixel, 280 mu m thick, back-illuminated, p-channel CCD that can be over-depleted. The PSF is measured over a wavelength range of 450 nm to 650 nm and at substrate bias voltages between 6 V and 80 V.

  1. The model of illumination-transillumination for image enhancement of X-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Kwang Yeul [Shingu College, Sungnam (Korea, Republic of); Rhee, Sang Min [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2001-06-01

    In digital image processing, the homomorphic filtering approach is derived from an illumination - reflectance model of the image. It can also be used with an illumination-transillumination model X-ray film. Several X-ray images were applied to enhancement with histogram equalization and homomorphic filter based on an illumination-transillumination model. The homomorphic filter has proven theoretical claim of image density range compression and balanced contrast enhancement, and also was found a valuable tool to process analog X-ray images to digital images.

  2. In vivo deep brain imaging of rats using oral-cavity illuminated photoacoustic computed tomography

    Science.gov (United States)

    Lin, Li; Xia, Jun; Wong, Terence T. W.; Zhang, Ruiying; Wang, Lihong V.

    2015-03-01

    We demonstrate, by means of internal light delivery, photoacoustic imaging of the deep brain of rats in vivo. With fiber illumination via the oral cavity, we delivered light directly into the bottom of the brain, much more than can be delivered by external illumination. The study was performed using a photoacoustic computed tomography (PACT) system equipped with a 512-element full-ring transducer array, providing a full two-dimensional view aperture. Using internal illumination, the PACT system provided clear cross sectional photoacoustic images from the palate to the middle brain of live rats, revealing deep brain structures such as the hypothalamus, brain stem, and cerebral medulla.

  3. Diffractive axicons in oblique illumination: analysis and experiments and comparison with elliptical axicons.

    Science.gov (United States)

    Thaning, Anna; Jaroszewicz, Zbigniew; Friberg, Ari T

    2003-01-01

    Axicons in oblique illumination produce broadened focal lines, a problem, e.g., in scanning applications. A compact mathematical description of the focal segment is presented, for the first time, to our knowledge, and the results are compared with elliptical axicons in normal illumination. In both cases, analytical expressions in the form of asteroid curves are obtained from asymptotic wave theory and caustic surfaces. The results are confirmed by direct diffraction simulations and by experiments. In addition we show that at a fixed angle an elliptical axicon can be used to compensate for the adverse effects of oblique illumination.

  4. Illumination technique for the relative calibration of the ASTRI SST-2M camera

    International Nuclear Information System (INIS)

    Rodeghiero, Gabriele; Catalano, Osvaldo; Segreto, Alberto; De Caprio, Vincenzo; Giro, Enrico; Lessio, Luigi; Conconi, Paolo; Canestrari, Rodolfo

    2014-01-01

    We present a new illumination technique for the camera relative gain calibration of the ASTRI SST-2M Cherenkov telescope. The camera illumination is achieved by means of an optical fiber that diffuses the light inside a protective PMMA window above the focal plane. We report the encouraging results of the development tests carried out on two PMMA window prototypes illuminated by a standard optical fiber. We checked also the reliability of the method by a series of ray tracing simulations for different scattering models and PMMA window shapes finding good agreement with experimental results

  5. Illumination technique for the relative calibration of the ASTRI SST-2M camera

    Energy Technology Data Exchange (ETDEWEB)

    Rodeghiero, Gabriele, E-mail: gabriele.rodeghiero@studenti.unipd.it [Department of Physics and Astronomy, University of Padova, Vicolo dell' Osservatorio 5, 35100 PD (Italy); Catalano, Osvaldo; Segreto, Alberto [INAF IASF Palermo, Via Ugo La Malfa 153, 90146 PA (Italy); De Caprio, Vincenzo [INAF OACN, Salita Moiariello, 16, 80131 Napoli, NA (Italy); Giro, Enrico; Lessio, Luigi [INAF OAPD, Vicolo dell' Osservatorio 5, 35100 PD (Italy); Conconi, Paolo; Canestrari, Rodolfo [INAF OAB, Via E. Bianchi 46, 23807 Merate, LC (Italy)

    2014-11-11

    We present a new illumination technique for the camera relative gain calibration of the ASTRI SST-2M Cherenkov telescope. The camera illumination is achieved by means of an optical fiber that diffuses the light inside a protective PMMA window above the focal plane. We report the encouraging results of the development tests carried out on two PMMA window prototypes illuminated by a standard optical fiber. We checked also the reliability of the method by a series of ray tracing simulations for different scattering models and PMMA window shapes finding good agreement with experimental results.

  6. [Effects of illumination and seed-soaking reagent on seed germination of Solanum nigrum].

    Science.gov (United States)

    Yang, Chuan-Jie; Wei, Shu-He; Zhou, Qi-Xing; Hu, Ya-Hu; Niu, Rong-Cheng

    2009-05-01

    To explore a rapid seed germination method for hyperaccumulator Solanum nigrum, a germination experiment with different illumination and seed-soaking treatments was conducted in constant temperature box and greenhouse, with filter as burgeon base. Under illumination, the germination rate was about 5 times high of that without illumination (P seed germination of S. nigrum. All test seed-soaking reagents could significantly improve the germination rate of S. nigrum (P seeds treated with H2O2 had the shortest germination time. The germination rate of seeds soaked but without cleaning was 2-3 times as high as that of seeds soaked and cleaned with water.

  7. Relaxometry imaging of superparamagnetic magnetite nanoparticles at ambient conditions

    Science.gov (United States)

    Finkler, Amit; Schmid-Lorch, Dominik; Häberle, Thomas; Reinhard, Friedemann; Zappe, Andrea; Slota, Michael; Bogani, Lapo; Wrachtrup, Jörg

    We present a novel technique to image superparamagnetic iron oxide nanoparticles via their fluctuating magnetic fields. The detection is based on the nitrogen-vacancy (NV) color center in diamond, which allows optically detected magnetic resonance (ODMR) measurements on its electron spin structure. In combination with an atomic-force-microscope, this atomic-sized color center maps ambient magnetic fields in a wide frequency range from DC up to several GHz, while retaining a high spatial resolution in the sub-nanometer range. We demonstrate imaging of single 10 nm sized magnetite nanoparticles using this spin noise detection technique. By fitting simulations (Ornstein-Uhlenbeck process) to the data, we are able to infer additional information on such a particle and its dynamics, like the attempt frequency and the anisotropy constant. This is of high interest to the proposed application of magnetite nanoparticles as an alternative MRI contrast agent or to the field of particle-aided tumor hyperthermia.

  8. Harvesting Ambient Environmental Energy for Wireless Sensor Networks: A Survey

    Directory of Open Access Journals (Sweden)

    Gongbo Zhou

    2014-01-01

    Full Text Available In recent years, wireless sensor networks (WSNs have grown dramatically and made a great progress in many applications. But having limited life, batteries, as the power sources of wireless sensor nodes, have restricted the development and application of WSNs which often requires a very long lifespan for better performance. In order to make the WSNs prevalent in our lives, an alternative energy source is required. Environmental energy is an attractive power source, and it provides an approach to make the sensor nodes self-powered with the possibility of an almost infinite lifetime. The goal of this survey is to present a comprehensive review of the recent literature on the various possible energy harvesting technologies from ambient environment for WSNs.

  9. Development of alternative sulfur dioxide control strategies for a metropolitan area and its environs, utilizing a modified climatological dispersion model

    Science.gov (United States)

    K. J. Skipka; D. B. Smith

    1977-01-01

    Alternative control strategies were developed for achieving compliance with ambient air quality standards in Portland, Maine, and its environs, using a modified climatological dispersion model (CDM) and manipulating the sulfur content of the fuel oil consumed in four concentric zones. Strategies were evaluated for their impact on ambient air quality, economics, and...

  10. Study in static mode of a photovoltaic cell bi facial to crystalline silicon under electric polarization and constant multispectral illumination

    International Nuclear Information System (INIS)

    ZOUNGRANA Martial

    2000-01-01

    The theoretical study in static mode of a photovoltaic cell bi facial to silicon under electric polarization and multispectral illumination is presented. Through this study, various expressions of the parameters of recombination have been established as well for an illumination by the face before an illumination by the back face. Curves of variation of the densities of carriers, densities of photocurrent, speeds of recombinations and photo tensions have been traced for the two modes of illumination [fr

  11. What Videogame Making Can Teach Us about Literacy and Learning: Alternative Pathways into Participatory Culture

    Science.gov (United States)

    Peppler, Kylie A.; Kafai, Yasmin B.

    2007-01-01

    In this paper we articulate an alternative approach to look at video games and learning to become a creator and contributor in the digital culture. Previous discussions have focused mostly on playing games and learning. Here, we discuss game making approaches and their benefits for illuminating game preferences and learning both software design…

  12. Prototype of a flat-panel photoreactor using TiO2 nanoparticles coated on transparent granules for the degradation of Methylene Blue under solar illumination

    Directory of Open Access Journals (Sweden)

    Sutisna

    2017-07-01

    Full Text Available The purpose of this work is to design a prototype of a flat-panel (FP photoreactor for wastewater treatment via solar illumination using TiO2 nano-photocatalysts. The TiO2 nanoparticles are initially coated on transparent plastic granules to avoid the difficulties associated with the recovery of nanoparticles after completing the treatment process. The coated granules were distributed in the space inside the reactor panel. The upper cover of the reactor is a transparent material that allows light penetration to activate the catalyst. Wastewater is circulated into the spaces between the coated granules. When exposed to solar illumination, photocatalytic reactions occur on nearly the entire surface of the coated granules. To test the reactor viability, we used technical grade TiO2 (for affordability and a solution of Methylene Blue (MB as a sample of wastewater. The photoreactor was tested for treating 30 L of MB solution with an initial concentration of 25 mg L−1. We observed that the reactor was able to degrade more than 98% of the MB in the solution after 48 h of solar illumination. The performance of the FP photoreactor was also improved by arranging several reactor panels in series. Using four panels, we observed that the complete decomposition of the same MB solution can be achieved within 10 h. The proposed FP photoreactor is a very promising alternative for use in decomposing recalcitrant organic pollutants in wastewater.

  13. Measurement of ambient aerosol hydration state at Great Smoky Mountains National Park in the southeastern United States

    Directory of Open Access Journals (Sweden)

    N. F. Taylor

    2011-12-01

    Full Text Available We present results from two field deployments of a unique tandem differential mobility analyzer (TDMA configuration with two primary capabilities: identifying alternative stable or meta-stable ambient aerosol hydration states associated with hysteresis in aerosol hydration behavior and determining the actual Ambient hydration State (AS-TDMA. This data set is the first to fully classify the ambient hydration state of aerosols despite recognition that hydration state significantly impacts the roles of aerosols in climate, visibility and heterogeneous chemistry. The AS-TDMA was installed at a site in eastern Tennessee on the border of Great Smoky Mountains National Park for projects during the summer of 2006 and winter of 2007–2008. During the summer, 12% of the aerosols sampled in continuous AS-TDMA measurements were found to posses two possible hydration states under ambient conditions. In every case, the more hydrated of the possible states was occupied. The remaining 88% did not posses multiple possible states. In continuous measurements during the winter, 49% of the aerosols sampled possessed two possible ambient hydration states; the remainder possessed only one. Of those aerosols with multiple possible ambient hydration states, 65% occupied the more hydrated state; 35% occupied the less hydrated state. This seasonal contrast is supported by differences in the fine particulate (PM2.5 composition and ambient RH as measured during the two study periods. In addition to seasonal summaries, this work includes case studies depicting the variation of hydration state with changing atmospheric conditions.

  14. Evaluación ambiental del PRMC

    Directory of Open Access Journals (Sweden)

    Waldo López Moya

    2001-12-01

    Full Text Available El presente artículo es una revisión constructiva de las actuales disposiciones sobre la evaluación ambiental de los planes reguladores, intentada con el propósito de contribuir a mejorar los procedimientos en práctica. En este sentido, aboga porque al plan regulador no se le exijan contribuciones ambientales que excedan a sus verdaderas competencias, para lo cual introduce el concepto de "efectos territoriales"; justifica que su evaluación ambiental deba ser realizda mediante una "declaración", y ahonda en la forma de elaborar y presentar esta declaración, acogiendo lo que a este respecto estipula el Art. 15° del Reglamento de la ley sobre Bases Generales del Medio Ambiente.

  15. Ambient Field Analysis at Groningen Gas Field

    Science.gov (United States)

    Spica, Z.; Nakata, N.; Beroza, G. C.

    2016-12-01

    We analyze continuous ambient-field data at Groningen gas field (Netherlands) through cross-correlation processing. The Groningen array is composed of 75 shallow boreholes with 6 km spacing, which contain a 3C surface accelerometer and four 5-Hz 3C borehole geophones spaced at 50 m depth intervals. We successfully retrieve coherent waves from ambient seismic field on the 9 components between stations. Results show high SNR signal in the frequency range of 0.125-1 Hz, and the ZZ, ZR, RZ, RR and TT components show much stronger wave energy than other components as expected. This poster discuss the different type of waves retrieved, the utility of the combination of borehole and surface observations, future development as well as the importance to compute the 9 components of the Green's tensor to better understand the wave field propriety with ambient noise.

  16. Ocean Ambient Noise Measurement and Theory

    CERN Document Server

    Carey, William M

    2011-01-01

    This book develops the theory of ocean ambient noise mechanisms and measurements, and also describes general noise characteristics and computational methods.  It concisely summarizes the vast ambient noise literature using theory combined with key representative results.  The air-sea boundary interaction zone is described in terms of non-dimensional variables requisite for future experiments.  Noise field coherency, rare directional measurements, and unique basin scale computations and methods are presented.  The use of satellite measurements in these basin scale models is demonstrated.  Finally, this book provides a series of appendices giving in-depth mathematical treatments.  With its complete and careful discussions of both theory and experimental results, this book will be of the greatest interest to graduate students and active researchers working in fields related to ambient noise in the ocean.

  17. Ambient air pollution and low birth weight

    DEFF Research Database (Denmark)

    Westergaard, Nadja; Gehring, Ulrike; Slama, Rémy

    2017-01-01

    (TLBW, restriction (IUGR), and suggest that some subgroups of pregnant women who are smoking, of low or high body-mass index (BMI), low socioeconomic status (SES) or asthma are more vulnerable towards...... on the association between ambient air pollution and TLBW. The adjusted odds ratio (OR) for TLBW associated with exposure to ambient air pollution were in one study higher among women who smoked during pregnancy, as compared to the OR of non-smoking women, while in the other study the association was in the opposite...... direction. The association of ambient air pollution and TLBW were higher among women characterized by extreme BMI (two studies) and low SES compared to non-obese women or women of higher SES (four studies), respectively. Only one study reported the estimated effects among asthmatic and non-asthmatic women...

  18. Ambient Air Pollution and Morbidity in Chinese.

    Science.gov (United States)

    Hu, Li-Wen; Lawrence, Wayne R; Liu, Yimin; Yang, Bo-Yi; Zeng, Xiao-Wen; Chen, Wen; Dong, Guang-Hui

    2017-01-01

    The rapid economic growth in China is coupled with a severe ambient air pollution, which poses a huge threat to human health and the sustainable development of social economy. The rapid urbanization and industrialization over the last three decades have placed China as one of countries with the greatest disease burden in world. Notably, the prevalence rate of chronic noncommunicable diseases (CND), including respiratory diseases, CVD, and stroke, in 2010 reaches 16.9%. The continuous growth of the incidence of CND urgent needs for effective regulatory action for health protection. This study aims to evaluate the impact of rapid urbanization on status of ambient air pollution and associated adverse health effects on the incidence and the burden of CND and risk assessment. Our findings would be greatly significant in the prediction of the risk of ambient air pollution on CND and for evidence-based policy making and risk management in China.

  19. Low-Light-Level InGaAs focal plane arrays with and without illumination

    Science.gov (United States)

    Macdougal, Michael; Geske, Jon; Wang, Chad; Follman, David

    2010-04-01

    Short wavelength IR imaging using InGaAs-based FPAs is shown. Aerius demonstrates low dark current in InGaAs detector arrays with 15 μm pixel pitch. The same material is mated with a 640x 512 CTIA-based readout integrated circuit. The resulting FPA is capable of imaging photon fluxes with wavelengths between 1 and 1.6 microns at low light levels. The mean dark current density on the FPAs is extremely low at 0.64 nA/cm2 at 10°C. Noise due to the readout can be reduced from 95 to 57 electrons by using off-chip correlated double sampling (CDS). In addition, Aerius has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide speckle-free illumination, provide artifact-free imagery versus conventional laser illuminators.

  20. Readability of self-illuminated signs in a smoke-obscured environment.

    Science.gov (United States)

    1979-11-01

    This study investigates the ability of people with normal distant visual acuity to identify self-illuminated emergency signs in a smoke-obscured environment. The results indicate that signs whose background luminance meets or exceeds the requirements...

  1. Curcumin uptake enhancement using low dose light illumination during incubation in Candida albicans

    Science.gov (United States)

    Romano, Renan A.; Pratavieira, Sebastião.; da Silva, Ana P.; Kurachi, Cristina; Bagnato, Vanderlei S.; Guimarães, Francisco E. G.

    2017-07-01

    A new PDI protocol is presented in this study. C. albicans cells pre-illuminated with a low dose light demonstrated an increase of curcumin uptake when compared to dark incubation, leading to a higher PDI efficacy.

  2. Probabilistic BPRRC: Robust Change Detection against Illumination Changes and Background Movements

    Science.gov (United States)

    Yokoi, Kentaro

    This paper presents Probabilistic Bi-polar Radial Reach Correlation (PrBPRRC), a change detection method that is robust against illumination changes and background movements. Most of the traditional change detection methods are robust against either illumination changes or background movements; BPRRC is one of the illumination-robust change detection methods. We introduce a probabilistic background texture model into BPRRC and add the robustness against background movements including foreground invasions such as moving cars, walking people, swaying trees, and falling snow. We show the superiority of PrBPRRC in the environment with illumination changes and background movements by using three public datasets and one private dataset: ATON Highway data, Karlsruhe traffic sequence data, PETS 2007 data, and Walking-in-a-room data.

  3. Rolled-Up Nanotech: Illumination-Controlled Hydrofluoric Acid Etching of AlAs Sacrificial Layers

    Directory of Open Access Journals (Sweden)

    Costescu Ruxandra

    2009-01-01

    Full Text Available Abstract The effect of illumination on the hydrofluoric acid etching of AlAs sacrificial layers with systematically varied thicknesses in order to release and roll up InGaAs/GaAs bilayers was studied. For thicknesses of AlAs below 10 nm, there were two etching regimes for the area under illumination: one at low illumination intensities, in which the etching and releasing proceeds as expected and one at higher intensities in which the etching and any releasing are completely suppressed. The “etch suppression” area is well defined by the illumination spot, a feature that can be used to create heterogeneously etched regions with a high degree of control, shown here on patterned samples. Together with the studied self-limitation effect, the technique offers a way to determine the position of rolled-up micro- and nanotubes independently from the predefined lithographic pattern.

  4. Light illumination effects in ambipolar FETs based on poly(3-hexylthiophene) and fullerene derivative composite films

    International Nuclear Information System (INIS)

    Shibao, Miho; Morita, Takeomi; Takashima, Wataru; Kaneto, Keiichi

    2008-01-01

    The effects of light illumination on field effect transistors based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C 61 -butyric methyl ester (PCBM) composite films have been studied. It is found that the light illumination on pure P3HT and PCBM generally resulted in decrease of the threshold voltages and increase of the mobilities by a little. In the composite film at the PCBM contents of x = [P3HT] / ([P3HT] + [PCBM]) = 0.67 ∼ 0.9, an ambipolar field transport appeared. The light illumination effect was observed remarkably in the shift of threshold voltage for the hole generation at x = 0.75. Variations of Hole and electron mobilities and threshold voltage of electron generation upon light illumination were basically similar to those of the pure materials. The results were discussed in terms of the light assisted carrier generation in field effects

  5. IR Image upconversion using band-limited ASE illumination fiber sources.

    Science.gov (United States)

    Maestre, H; Torregrosa, A J; Capmany, J

    2016-04-18

    We study the field-of-view (FOV) of an upconversion imaging system that employs an Amplified Spontaneous Emission (ASE) fiber source to illuminate a transmission target. As an intermediate case between narrowband laser and thermal illumination, an ASE fiber source allows for higher spectral intensity than thermal illumination and still keeps a broad wavelength spectrum to take advantage of an increased non-collinear phase-matching angle acceptance that enlarges the FOV of the upconversion system when compared to using narrowband laser illumination. A model is presented to predict the angular acceptance of the upconverter in terms of focusing and ASE spectral width and allocation. The model is experimentally checked in case of 1550-630 nm upconversion.

  6. Integrated LED/Imaging Illumination Panels Demonstrated within a Small Plant Growth Chamber Project

    Data.gov (United States)

    National Aeronautics and Space Administration — LED light sources are ideal for plant growth systems. However, commercially available multi-color LED illumination panels are designed and manufactured to produce a...

  7. Effects of illumination and packaging on non-heme iron and color attributes of sliced ham.

    Science.gov (United States)

    Li, H; Li, C B; Xu, X L; Zhou, G H

    2012-08-01

    This study was designed to investigate effects of illumination and packaging on color of cooked cured sliced ham during refrigeration, and the possibility of decomposition of nitrosylheme under light and oxygen exposure. Three illumination levels and three packaging films with different oxygen transmission rates (OTRs) were used in two separate experiments during 35 days storage, and pH value, a* value, nitrosylheme, residual nitrite and non-heme iron were evaluated. Packaging OTRs had significant effects (P0.05) nitrosylheme concentration during storage. For both groups, storage time had a significant effect (P<0.01) on a* value and nitrosylheme. Negative relationships between nitrosylheme and nitrite in the illumination group, and between nitrosylheme and non-heme iron in the packaging group were observed. Therefore, illumination level and packaging OTR had limited effects on overall pigment stability, but more discoloration and loss of redness occurred on the surface of products. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Rectangular illumination using a secondary optics with cylindrical lens for LED street light.

    Science.gov (United States)

    Chen, Hsi-Chao; Lin, Jun-Yu; Chiu, Hsuan-Yi

    2013-02-11

    The illumination pattern of an LED street light is required to have a rectangular distribution at a divergence-angle ratio of 7:3 for economical illumination. Hence, research supplying a secondary optics with two cylindrical lenses was different from free-form curvature for rectangular illumination. The analytical solution for curvatures with different ratio rectangles solved this detail by light tracing and boundary conditions. Similarities between the experiments and the simulation for a single LED and a 9-LED module were analyzed by Normalized Cross Correlation (NCC), and the error rate was studied by the Root Mean Square (RMS). The tolerance of position must be kept under ± 0.2 mm in the x, y and z directions to ensure that the relative illumination is over 99%.

  9. Improvement of illumination uniformity for LED flat panel light by using micro-secondary lens array.

    Science.gov (United States)

    Lee, Hsiao-Wen; Lin, Bor-Shyh

    2012-11-05

    LED flat panel light is an innovative lighting product in recent years. However, current flat panel light products still contain some drawbacks, such as narrow lighting areas and hot spots. In this study, a micro-secondary lens array technique was proposed and applied for the design of the light guide surface to improve the illumination uniformity. By using the micro-secondary lens array, the candela distribution of the LED flat panel light can be adjusted to similar to batwing distribution to improve the illumination uniformity. The experimental results show that the enhancement of the floor illumination uniformity is about 61%, and that of the wall illumination uniformity is about 20.5%.

  10. Applications of 'edge-on' illuminated porous plate detectors for diagnostic X-ray imaging

    CERN Document Server

    Shikhaliev, P M

    2002-01-01

    Scanning X-ray imaging systems for non-invasive diagnostics have several advantages over conventional imaging systems using area detectors. They significantly reduce the detected scatter radiation, cover large areas and potentially provide high spatial resolution. Applications of one-dimensional gaseous detectors and 'edge-on' illuminated silicon strip detectors for scanning imaging systems are currently under intensive investigation. The purpose of this work is to investigate 'edge-on' illuminated Porous Plate (PP) detectors for applications in diagnostic X-ray imaging. MicroChannel Plate (MCP), which is a common type of PP, has previously been investigated as a detector in surface-on illumination mode for medical X-ray imaging. However, its detection efficiency was too low for medical imaging applications. In the present study, the PP are used in the 'edge-on' illumination mode. Furthermore, the structural parameters of different PP types are optimized to improve the detection efficiency in the diagnostic X...

  11. Hybrid Logical Analyses of the Ambient Calculus

    DEFF Research Database (Denmark)

    Bolander, Thomas; Hansen, René Rydhof

    2007-01-01

    In this paper, hybrid logic is used to formulate a rational reconstruction of a previously published control flow analysis for the mobile ambients calculus and we further show how a more precise flow-sensitive analysis, that takes the ordering of action sequences into account, can be formulated...... in a natural way. We show that hybrid logic is very well suited to express the semantic structure of the ambient calculus and how features of hybrid logic can be exploited to reduce the "administrative overhead" of the analysis specification and thus simplify it. Finally, we use HyLoTab, a fully automated...

  12. Comercio Internacional y Medio Ambiente en Colombia

    OpenAIRE

    Pérez Rincón, Mario Alejandro

    2006-01-01

    Consultable des del TDX A portada: Programa de Doctorado en Ciencias Ambientales, Opción Economía Ecológica y Gestión Ambiental A portada: Institut de Ciència i Tecnologia Ambientals (ICTA) Títol obtingut de la portada digitalitzada Desde la perspectiva de la Economía Ecológica, el Comercio Internacional no es un juego de suma positiva donde todos los participantes resultan ganadores por el intercambio comercial, sino que es un juego de suma cero, donde hay beneficiados y perjudic...

  13. Territorios vulnerables e injusticia ambiental en Argentina

    OpenAIRE

    Miguel Lacabana; Clara Bressano

    2016-01-01

    Justicia ambiental es un concepto fructífero en tanto modificó la perspectiva clásica de análisis sobre el problema de la degradación ambiental al establecer como principal interrogante no tanto las "causas" que producen tal degradación sino que interroga el proceso político, económico y social que consolida la desigual distribución social de las cargas nocivas de la contaminación. El conurbano sur de Buenos Aires y dentro de este el Municipio de Quilmes condensan distintas situaciones se vul...

  14. Human-Centric Interfaces for Ambient Intelligence

    CERN Document Server

    Aghajan, Hamid; Delgado, Ramon Lopez-Cozar

    2009-01-01

    To create truly effective human-centric ambient intelligence systems both engineering and computing methods are needed. This is the first book to bridge data processing and intelligent reasoning methods for the creation of human-centered ambient intelligence systems. Interdisciplinary in nature, the book covers topics such as multi-modal interfaces, human-computer interaction, smart environments and pervasive computing, addressing principles, paradigms, methods and applications. This book will be an ideal reference for university researchers, R&D engineers, computer engineers, and graduate s

  15. No queremos medio ambiente, lo queremos completo

    OpenAIRE

    Hederich G., Federico

    2018-01-01

    Sí bien es evidente la relación Hombre Medio Ambiente, no todos tenemos clara la manera como interactuamos interrumpiendo el desarrollo armónico de esta relación.El primer punto que vamos a tratar pretende esclarecer el significado de dos palabras básicas cuando se trata el tema del medio ambiente, en primera instancia, el término «basura» que se define como inmundicia, estiércol, y luego analizaremos «desperdicio» que significa derroche, residuo.Sí analizamos profundamente estas dos palabras...

  16. A RESPONSABILIDADE CIVIL E O MEIO AMBIENTE

    Directory of Open Access Journals (Sweden)

    DELCYLENE VILLALBA SOARES

    2012-06-01

    Full Text Available RESUMOEste artigo tem por finalidade realizar uma análise sobre a evolução da responsabilidade civil e suas teorias, subjetiva e objetiva aplicadas ao meio ambiente. Dentro desta área, deve-se ressaltar que a responsabilidade civil ao meio ambiente, é um assunto de importante relevância para o efetivo controle da depredação ambiental, permitindo que sejam alcançadas as metas propostas como condição de sobrevivência da espécie humana, ou seja, a conservação do meio ambiente e o desenvolvimento econômico social, visando desta maneira, permitir a qualidade e a continuação da vida. Existe o entendimento, que somente com educação ambiental e normas reguladoras fortes, como a penalidade de ter que indenizar quando praticar algum dano ao meio ambiente conseguirá atingir o objetivo maior de preservação. Necessitam-se além de uma mudança na legislação que responsabilize poluidores do meio ambiente, atribuindo-lhes sanções que inibam a prática de tal conduta ilícita e realizando assim, a aplicabilidade da justiça.Palavras-chave:Responsabilidade Civil; Responsabilidade; Meio Ambiente ABSTRACTThis article have objective to realize a analysis about civil responsibility evolution and your theories, subjective and objective apply environment. Inside this area have to stand out that civil responsibility environment, it is a theme very important relevance for environment depredation control effective, permitting have been obtain proposals target like been human survival condition, therefore, environment conservation and social economic development objective permit quality and continuation of life. There is understanding, that only with environment education and strong regulation principle, like penalty has to indemnify when practice some injury of environment, will obtain more preservation. Demand a change on legislation that responsible environment polluter attribute him inhibit sanctions for practice this illicit conduct and

  17. 130 LPW 1000 Lm Warm White LED for Illumination

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-21

    An illumination-grade warm-white LED, having correlated color temperature (CCT) between 2700 and 3500 K and capable of producing 1000 lm output at over 130 lm/W at room temperature, has been developed in this program. The high-power warm-white LED is an ideal source for use in indoor and outdoor lighting applications. Over the two year period, we have made the following accomplishments: • Developed a low-cost high-power white LED package and commercialized a series of products with CCT ranging from 2700 to 5700 K under the product name LUXEON M; • Demonstrated a record efficacy of 124.8 lm/W at a flux of 1023 lm, CCT of 3435 K and color rendering index (CRI) over 80 at room temperature in the productized package; • Demonstrated a record efficacy of 133.1 lm/W at a flux of 1015 lm, CCT of 3475 K and CRI over 80 at room temperature in an R&D package. The new high-power LED package is a die-on-ceramic surface mountable LED package. It has four 2 mm2 InGaN pump dice, flip-chip attached to a ceramic submount in a 2x2 array configuration. The submount design utilizes a design approach that combines a high-thermal- conductivity ceramic core for die attach and a low-cost and low-thermal-conductivity ceramic frame for mechanical support and as optical lens carrier. The LED package has a thermal resistance of less than 1.25 K/W. The white LED fabrication also adopts a new batch level (instead of die-by-die) phosphor deposition process with precision layer thickness and composition control, which provides not only tight color control, but also low cost. The efficacy performance goal was achieved through the progress in following key areas: (1) high-efficiency royal blue pump LED development through active region design and epitaxial growth quality improvement (funded by internal programs); (2) improvement in extraction efficiency from the LED package through improvement of InGaN-die-level and package-level optical extraction efficiency; and (3) improvement in phosphor

  18. Optimal sun-shading design for enhanced daylight illumination of subtropical classrooms

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Ming-Chin [Architecture and Building Research Institute, MOI (China); Chiang, Che-Ming [Department of Architecture, National Cheng-Kung University, Tainan 701 (China); Chou, Po-Cheng [Department of Interior Design, Shu-Te University, No. 59 Hun-Shan Road, Yenchau 82445, Kaohsiung County (China); Chang, Kuei-Feng [Department of Real Estate Management, National Pingtung Institute of Commerce (China); Lee, Chia-Yen [Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua 515 (China)

    2008-07-01

    This study investigates the feasibility of fitting windows with sun-shadings in order to minimize the lighting power costs in daylight-illuminated classrooms lit from a single side in subtropical regions. An IES-CPC model is created of a representative classroom in Taiwan, and a series of simulations is performed to determine the average illuminance value and the uniformity of the illuminance distribution in the classroom under various lighting conditions with no sun-shadings fitted to the window. The numerical results are found to be in good agreement with the experimental measurements obtained using an array of nine-channel photometers. Having confirmed the validity of the simulation scheme, the illumination properties of four different sun-shading designs are considered. The results show that a double-layered sun-shading represents the optimal sun-shading design in terms of achieving a uniform illumination distribution within the classroom. Given appropriate physical dimensions, this daylight access device achieves the minimum illuminance requirement of 500 lx and improves the lighting uniformity ratio from 0.25-0.35 to 0.40-0.42. Furthermore, using this sun-shading device, the required illuminance ratio of 0.5 can be obtained simply by switching on one of the three rows of lights in the classroom. Accordingly, the daylight access device not only improves the illuminance conditions within the classroom, but also reduces the lighting power cost by 71.5% compared to the case where all of the lights are turned on. (author)

  19. Illuminance-based slat angle selection model for automated control of split blinds

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jia; Olbina, Svetlana [Rinker School of Building Construction, University of Florida, Gainesville, FL 32611-5703 (United States)

    2011-03-15

    Venetian blinds play an important role in controlling daylight in buildings. Automated blinds overcome some limitations of manual blinds; however, the existing automated systems mainly control the direct solar radiation and glare and cannot be used for controlling innovative blind systems such as split blinds. This research developed an Illuminance-based Slat Angle Selection (ISAS) model that predicts the optimum slat angles of split blinds to achieve the designed indoor illuminance. The model was constructed based on a series of multi-layer feed-forward artificial neural networks (ANNs). The illuminance values at the sensor points used to develop the ANNs were obtained by the software EnergyPlus trademark. The weather determinants (such as horizontal illuminance and sun angles) were used as the input variables for the ANNs. The illuminance level at a sensor point was the output variable for the ANNs. The ISAS model was validated by evaluating the errors in the calculation of the: 1) illuminance and 2) optimum slat angles. The validation results showed that the power of the ISAS model to predict illuminance was 94.7% while its power to calculate the optimum slat angles was 98.5%. For about 90% of time in the year, the illuminance percentage errors were less than 10%, and the percentage errors in calculating the optimum slat angles were less than 5%. This research offers a new approach for the automated control of split blinds and a guide for future research to utilize the adaptive nature of ANNs to develop a more practical and applicable blind control system. (author)

  20. The effect of background and illumination on color identification of real, 3D objects

    OpenAIRE

    Allred, Sarah R.; Olkkonen, Maria

    2013-01-01

    For the surface reflectance of an object to be a useful cue to object identity, judgments of its color should remain stable across changes in the object's environment. In 2D scenes, there is general consensus that color judgments are much more stable across illumination changes than background changes. Here we investigate whether these findings generalize to real 3D objects. Observers made color matches to cubes as we independently varied both the illumination impinging on the cube and th...