WorldWideScience

Sample records for technology evolution led

  1. LEDs: revolution or evolution? Part One

    Energy Technology Data Exchange (ETDEWEB)

    Roush, M.

    2000-11-01

    The historical evolution, the current state of light emitting diodes (LEDs), future implications and the promise of this technology for the lighting industry are explored. Some of the misconceptions relative to that promise are dispelled and some of the less obvious benefits that this technology could deliver in the future are discussed. As far as misconceptions are concerned, it is not true that LEDs will deliver light forever at a fraction of the energy of conventional light sources, or that they come in an infinite variety of colours and cost just pennies. Although LEDs per se may last a long time, the fact is that their true life expectancy is only as long as the wiring and the connection within the system, and they are certainly limited. Energy efficiency is another misconception. The truth is that white LEDs (the best for illumination purposes) are limited to less than 10 lumen per Watt, which is hardly a revolutionary improvement over incandescent light sources. Equally disappointing is the misconception concerning price. In actual fact, LEDs in lighting applications are very new and it would require mass production in the millions before LED lighting packages could become inexpensive. At the same time, LEDs have many advantages that are not commonly known. Compactness, very high level of light utilization, high life expectancy and nearly flat mortality curve are some of these. Operating on direct current lends LED installations to battery and solar applications (as for example solar LED road studs to aid in night driving). The absence of ultraviolet emissions in LEDs is another lesser known, but important feature, especially in applications where material degradation is a major concern (as in stores and museums). In general, all indicators point to a bright future for LEDs as their application progresses from decoration to illumination. This topic will be further explored in Part Two of this article. 4 figs.

  2. Next generation DNA led technologies

    CERN Document Server

    Jyothsna, G; Kashyap, Amita

    2016-01-01

    This brief highlights advances in DNA technologies and their wider applications. DNA is the source of life and has been studied since a generation, but very little is known as yet. Several sophisticated technologies of the current era have laid their foundations on the principle of DNA based mechanisms. DNA based technologies are bringing a new revolution of Advanced Science and Technology. Forensic Investigation, Medical Diagnosis, Paternity Disputes, Individual Identity, Health insurance, Motor Insurance have incorporated the DNA testing and profiling technologies for settling the issues.

  3. Computer technology and evolution

    OpenAIRE

    Mainzer, Klaus

    1998-01-01

    Computer technology and evolution : from artificial intelligence to artificial life. - In: Advances in the philosophy of technology / ed. by Evandro Agazzi ... - Newark, Del. : Soc. for Philosophy and Technology, 1999. - S. 105-119

  4. Sustainable LED Fluorescent Light Replacement Technology

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2011-09-30

    Ilumisys and the National Center for Manufacturing Sciences (NCMS) partnered on a three-year project awarded by the United States (U.S.) Department of Energy (DOE), to quantify the impacts of LED lamps, incandescent lamps and fluorescent benchmark lamps over a product lifecycle – i.e. to develop a sustainable design and manufacturing strategy that addresses product manufacturing, use, recycling and disposal scenarios for LED-based lighting. Based on the knowledge gained from extensive product tear-down studies of fluorescent and screw-in lighting products, lifecycle assessment tools, and accelerated lifecycle testing protocols, an interactive Sustainable LED Design Guide has been developed to aid architectural and lighting designers and engineers in making design decisions that consider three important environmental impacts (greenhouse gas emissions, energy use and mercury emission) across all phases of the life of an LED lighting product. Critical information developed for the lifecycle analysis and product feature comparisons is the useful life of the lighting product as well as its performance. The Design Guide is available at www.ncms.org, and was developed based on operational and durability testing of a variety of lighting products including power consumption, light output, and useful life of a lamp in order to allow a more realistic comparison of lamp designs. This report describes the main project tasks, results and innovative features of the lifecycle assessment (LCA)-based design tools, and the key considerations driving the sustainable design of LED lighting systems. The Design Guide incorporates the following three novel features for efficiently evaluating LED lighting features in value-chains: Bill-of-Materials (BOM) Builder – Designers may import process data for each component and supply functional data for the product, including power, consumption, lumen output and expected useful life: Environmental Impact Review – Designs are comparable

  5. Interior LED Lighting Technology. Navy Energy Technology Validation (Techval) Program

    Science.gov (United States)

    2015-09-01

    evaluated using the Illumination Engineering Societies’ (IES) TM-21 manual. The TM- 21 manual provides a standardized method for evaluating when an LED...the equipment. The Cree luminaires installed in this study are rated for 75,000 hours of service, based on calculation methods that extrapolated...should be replaced with LED lamps. • Replace MR-16 lamps with LED lamps since this type of fixture is used to provide accent lighting and is

  6. High power LEDs - technology status and market applications

    International Nuclear Information System (INIS)

    Steranka, F.M.; Bhat, J.; Collins, D.; Cook, L.; Craford, M.G.; Fletcher, R.; Gardner, N.; Grillot, P.; Goetz, W.; Keuper, M.; Khare, R.; Kim, A.; Krames, M.; Harbers, G.; Ludowise, M.; Martin, P.S.; Misra, M.; Mueller, G.; Mueller-Mach, R.; Rudaz, S.; Shen, Y.C.; Steigerwald, D.; Subramanya, S.; Trottier, T.; Wierer, J.J.

    2002-01-01

    High power light emitting diodes (LEDs) continue to increase in output flux with the best III-nitride based devices today emitting over 150 lm of white, cyan, or green light. The key design features of such products will be covered with special emphasis on power packaging, flip-chip device design, and phosphor coating technology. The high-flux performance of these devices is enabling many new applications for LEDs. Two of the most interesting of these applications are LCD display backlighting and vehicle forward lighting. The advantages of LEDs over competing lighting technologies will be covered in detail. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  7. Reliable LED Lighting Technologies: Key Factors and Procurement Guidance

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Lynn; Arquit Niederberger, Anne

    2015-10-08

    Abstract— Lighting systems have the ability to transform the economic and educational infrastructure of disadvantaged communities, and eradicating “light poverty” has become one of the primary goals of the International Year of Light 2015. Solid-state lighting (SSL) technology, based on light-emitting diode (LED) light sources, has emerged as the next generation of lighting technology, with a current global market penetration of roughly 5%. This paper will report on recent research on understanding SSL lighting system reliability (failure modes, environmental stressors, electrical power quality); discuss the implications of SSL technology reliability for providing lighting services; and suggest practical approaches to ensure SSL reliability to benefit humanity. Among the key findings from this work is that LED sources can be extremely reliable, withstanding a broad range of environmental stresses without failure. Nonetheless, SSL lighting systems can have a negative impact on electrical power reliability, as well as on the affordability of lighting services, without attention to the quality of the accompanying power infrastructure. It is therefore critical to ensure that the performance of the power supply electronics used in lighting systems is matched to the quality of the power source, when evaluating energy efficient lighting choices.

  8. Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

    OpenAIRE

    Stojanovic, Radovan; Karadaglic, Dejan

    2013-01-01

    A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (SpO2). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2). N-LEDs...

  9. Technology Revolution = Education Evolution.

    Science.gov (United States)

    McLafferty, Charles L., Jr.

    2000-01-01

    Outlines one attempt to infuse technology into an educational psychology course, discussing commonly available tools and techniques (e.g., online syllabus, e-mail, World Wide Web, presentation packages, and use of learning teams and electronic discussion groups). The paper examines obstacles, student responses, application in the K-12 classroom,…

  10. Design of an oximeter based on LED-LED configuration and FPGA technology.

    Science.gov (United States)

    Stojanovic, Radovan; Karadaglic, Dejan

    2013-01-04

    A fully digital photoplethysmographic (PPG) sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED) for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA) is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (S(p)O(2)). The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (S(p)O(2)). N-LEDs configuration is proposed for multichannel S(p)O(2) measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

  11. Design of an Oximeter Based on LED-LED Configuration and FPGA Technology

    Directory of Open Access Journals (Sweden)

    Radovan Stojanovic

    2013-01-01

    Full Text Available A fully digital photoplethysmographic (PPG sensor and actuator has been developed. The sensing circuit uses one Light Emitting Diode (LED for emitting light into human tissue and one LED for detecting the reflectance light from human tissue. A Field Programmable Gate Array (FPGA is used to control the LEDs and determine the PPG and Blood Oxygen Saturation (SpO2. The configurations with two LEDs and four LEDs are developed for measuring PPG signal and Blood Oxygen Saturation (SpO2. N-LEDs configuration is proposed for multichannel SpO2 measurements. The approach resulted in better spectral sensitivity, increased and adjustable resolution, reduced noise, small size, low cost and low power consumption.

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

    NARCIS (Netherlands)

    Thomas, W.

    2014-01-01

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

  13. Technology Analysis of Global Smart Light Emitting Diode (LED Development Using Patent Data

    Directory of Open Access Journals (Sweden)

    Sangsung Park

    2017-08-01

    Full Text Available Technological developments related to smart light emitting diode (LED systems have progressed rapidly in recent years. In this paper, patent documents related to smart LED technology are collected and analyzed to understand the technology development of smart LED systems. Most previous studies of the technology were dependent on the knowledge and experience of domain experts, using techniques such as Delphi surveys or technology road-mapping. These approaches may be subjective and lack robustness, because the results can vary according to the selected expert groups. We therefore propose a new technology analysis methodology based on statistical modeling to obtain objective and relatively stable results. The proposed method consists of visualization based on Bayesian networks and a linear count model to analyze patent documents related to smart LED technology. Combining these results, a global hierarchical technology structure is created that can enhance the sustainability in smart LED system technology. In order to show how this methodology could be applied to real-world problems, we carry out a case study on the technology analysis of smart LED systems.

  14. Evolution of Biologics Screening Technologies

    OpenAIRE

    Matthew J. Gardener; Peter Cariuk; Tristan J. Vaughan

    2013-01-01

    Screening for biologics, in particular antibody drugs, has evolved significantly over the last 20 years. Initially, the screening processes and technologies from many years experience with small molecules were adopted and modified to suit the needs of biologics discovery. Since then, antibody drug discovery has matured significantly and is today investing earlier in new technologies that commercial suppliers are now developing specifically to meet the growing needs of large molecule screening...

  15. [Evolution of assisted reproductive technologies].

    Science.gov (United States)

    Jouannet, Pierre

    2009-03-01

    When natural conception is impossible and the underlying problem cannot be treated, medical intervention can reproduce the steps necessary for fertilization and early embryo development. The first known medical action in the field of human reproduction took place at the end of the 18th century, in the form of artificial insemination with the husband's semen, thus dissociating sexual intercourse from procreation. A further upheaval occurred at the end of the 19th century, with the use of donor sperm, separating the notions of genetic descent and parenthood. In the second half of the 20th century, medically assisted procreation saw two major technological advances, namely gamete freezing and in vitro fertilization (IVF). The first child conceived with frozen-thawed sperm was born in 1953, and the first IVF baby in 1978. Fertilization by intracytoplasmic sperm injection (ICSI), first developed in 1992, can overcome many causes of male infertility. The convergence of reproductive biology and genetics has now opened up the possibility of screening for chromosome and gene defects in the embryo, prior to implantation. Thus, assisted reproductive technologies (ART) not only serve as a substitute for natural conception but can also avoid the birth of a disabled child While new technologies continue to extend the available options for infertile couples, they also have the potential to help single women and homosexual couples to have children. These practices are currently only accepted in certain countries. Overall, these new medical technologies have contributed to changing our conception of human reproduction, opening up new paradigms of parenthood and raising new challenges for society.

  16. Evolution of LTCC technology for industrial applications

    OpenAIRE

    Massiot, Michel

    2002-01-01

    The LTCC (Low Temperature Cofired Ceramic) technology has been used for years in various applications like automotive (under the hood), data-processing, telecoms, datacoms, military and space, industrial, packaging. The evolution of the materials, processes and approach have reinforced its cost and performance attractivity. This is particularly true in the case of high frequency / optoelectronic products. This paper gives an overview of the enabling features of the LTCC technology for these a...

  17. "Physics Stories": How the Early Technologies of High Voltage and High Vacuum Led to "Modern Physics"

    Science.gov (United States)

    Greenslade, Thomas B.

    2018-05-01

    Some of you may remember the 1979 television series "Connections" that was written and narrated by James Burke, a British science writer. Burke's technique was to choose a number of seemingly unrelated ideas and show how they led to developments in science and technology. This is an enjoyable business, even if some of the connections seem to be stretched at times, and led to a book by Burke. In a number of talks that I have given over the years, I have made somewhat less fanciful connections that suggest how the technologies of high vacuum and high voltage led to what used to be called "modern physics." Today we might limit the "modern" era to the years from 1890 to 1920 that gave the first workable theories of small-scale physics.

  18. Low power wide spectrum optical transmitter using avalanche mode LEDs in SOI CMOS technology

    NARCIS (Netherlands)

    Agarwal, Vishal Vishal; Dutta, Satadal; Annema, Anne J.; Hueting, Raymond Josephus Engelbart; Steeneken, P.G.; Nauta, Bram

    2017-01-01

    This paper presents a low power monolithically integrated optical transmitter with avalanche mode light emitting diodes in a 140 nm silicon-on-insulator CMOS technology. Avalanche mode LEDs in silicon exhibit wide-spectrum electroluminescence (400 nm < λ < 850 nm), which has a significant overlap

  19. Low power wide spectrum optical transmitter using avalanche mode LEDs in SOI CMOS technology

    NARCIS (Netherlands)

    Agarwal, V.; Dutta, S; Annema, AJ; Hueting, RJE; Steeneken, P.G.; Nauta, B

    2017-01-01

    This paper presents a low power monolithically integrated optical transmitter with avalanche mode light emitting diodes in a 140 nm silicon-on-insulator CMOS technology. Avalanche mode LEDs in silicon exhibit wide-spectrum electroluminescence (400 nm < λ < 850 nm), which has a significant

  20. Evolution of Indoor Positioning Technologies: A Survey

    Directory of Open Access Journals (Sweden)

    Ramon F. Brena

    2017-01-01

    Full Text Available Indoor positioning systems (IPS use sensors and communication technologies to locate objects in indoor environments. IPS are attracting scientific and enterprise interest because there is a big market opportunity for applying these technologies. There are many previous surveys on indoor positioning systems; however, most of them lack a solid classification scheme that would structurally map a wide field such as IPS, or omit several key technologies or have a limited perspective; finally, surveys rapidly become obsolete in an area as dynamic as IPS. The goal of this paper is to provide a technological perspective of indoor positioning systems, comprising a wide range of technologies and approaches. Further, we classify the existing approaches in a structure in order to guide the review and discussion of the different approaches. Finally, we present a comparison of indoor positioning approaches and present the evolution and trends that we foresee.

  1. Digestive peptidase evolution in holometabolous insects led to a divergent group of enzymes in Lepidoptera.

    Science.gov (United States)

    Dias, Renata O; Via, Allegra; Brandão, Marcelo M; Tramontano, Anna; Silva-Filho, Marcio C

    2015-03-01

    Trypsins and chymotrypsins are well-studied serine peptidases that cleave peptide bonds at the carboxyl side of basic and hydrophobic L-amino acids, respectively. These enzymes are largely responsible for the digestion of proteins. Three primary processes regulate the activity of these peptidases: secretion, precursor (zymogen) activation and substrate-binding site recognition. Here, we present a detailed phylogenetic analysis of trypsins and chymotrypsins in three orders of holometabolous insects and reveal divergent characteristics of Lepidoptera enzymes in comparison with those of Coleoptera and Diptera. In particular, trypsin subsite S1 was more hydrophilic in Lepidoptera than in Coleoptera and Diptera, whereas subsites S2-S4 were more hydrophobic, suggesting different substrate preferences. Furthermore, Lepidoptera displayed a lineage-specific trypsin group belonging only to the Noctuidae family. Evidence for facilitated trypsin auto-activation events were also observed in all the insect orders studied, with the characteristic zymogen activation motif complementary to the trypsin active site. In contrast, insect chymotrypsins did not seem to have a peculiar evolutionary history with respect to their mammal counterparts. Overall, our findings suggest that the need for fast digestion allowed holometabolous insects to evolve divergent groups of peptidases with high auto-activation rates, and highlight that the evolution of trypsins led to a most diverse group of enzymes in Lepidoptera. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Digestive peptidase evolution in holometabolous insects led to a divergent group of enzymes in Lepidoptera

    KAUST Repository

    Dias, Renata O.

    2015-03-01

    © 2015 Elsevier Ltd. Trypsins and chymotrypsins are well-studied serine peptidases that cleave peptide bonds at the carboxyl side of basic and hydrophobic l-amino acids, respectively. These enzymes are largely responsible for the digestion of proteins. Three primary processes regulate the activity of these peptidases: secretion, precursor (zymogen) activation and substrate-binding site recognition. Here, we present a detailed phylogenetic analysis of trypsins and chymotrypsins in three orders of holometabolous insects and reveal divergent characteristics of Lepidoptera enzymes in comparison with those of Coleoptera and Diptera. In particular, trypsin subsite S1 was more hydrophilic in Lepidoptera than in Coleoptera and Diptera, whereas subsites S2-S4 were more hydrophobic, suggesting different substrate preferences. Furthermore, Lepidoptera displayed a lineage-specific trypsin group belonging only to the Noctuidae family. Evidence for facilitated trypsin auto-activation events were also observed in all the insect orders studied, with the characteristic zymogen activation motif complementary to the trypsin active site. In contrast, insect chymotrypsins did not seem to have a peculiar evolutionary history with respect to their mammal counterparts. Overall, our findings suggest that the need for fast digestion allowed holometabolous insects to evolve divergent groups of peptidases with high auto-activation rates, and highlight that the evolution of trypsins led to a most diverse group of enzymes in Lepidoptera.

  3. Characterization of a nanoparticle-filled resin for application in scan-LED-technology.

    Science.gov (United States)

    Kolb, Eva; Kummerlöwe, Claudia; Klare, Martin

    2011-10-01

    Scan-LED-technology is a new rapid prototyping technique with increasing applications in the production of custom-made medical products. The present work is dealing with the examination of a silica/urethandimethacrylate (UDMA) nanocomposite for application in scan-LED-technology. The use of specific LED in a photo-DSC unit enables the simulation of crucial parameters of nanoparticle-filled resins for their application in scan-LED-technology. The conversion of double bonds during the curing reaction and the rate of conversion were studied as a function of radiation intensity, silica nanoparticle content, and silanization of the nanoparticles with 3-methacryloyloxypropyl-trimethoxysilane (MPTMS). The conversion of double bonds is increasing with increasing radiation intensity. The increasing conversion of the nanoparticle-filled resins is discussed as a combined effect of increasing nanoparticle content, alternated initiator/double bond ratio and increasing radiation intensity. A significant dependence of the reaction rate on nanoparticle content could not be found. Only for the unfilled resin, the rate was increasing at higher radiation intensities. The influence of residual solvent on conversion and rate of reaction was also analyzed. TGA measurements combined with FTIR were used to study the silanization of the nanoparticles. The silane layer thickness on the surface of the silica nanoparticles was determined.

  4. Assessment of LED Technology in Ornamental Post-Top Luminaires (Host Site: Sacramento, CA)

    Energy Technology Data Exchange (ETDEWEB)

    Tuenge, Jason R.

    2011-12-01

    The DOE Municipal Solid-State Street Lighting Consortium has evaluated four different LED replacements for existing ornamental post-top street lights in Sacramento, California. The project team was composed of the City and its consultant, PNNL (representing the Consortium), and the Sacramento Municipal Utility District. Product selection was finalized in March 2011, yielding one complete luminaire replacement and three lamp-ballast retrofit kits. Computer simulations, field measurements, and laboratory testing were performed to compare the performance and cost-effectiveness of the LED products relative to the existing luminaire with 100 W high-pressure sodium lamp. After it was confirmed the LED products were not equivalent to HPS in terms of initial photopic illumination, the following parameters were scaled proportionally to enable equitable (albeit hypothetical) comparisons: light output, input wattage, and pricing. Four replacement scenarios were considered for each LED product, incorporating new IES guidance for mesopic multipliers and lumen maintenance extrapolation, but life cycle analysis indicated cost effectiveness was also unacceptable. Although LED efficacy and pricing continue to improve, this project serves as a timely and objective notice that LED technology may not be quite ready yet for such applications.

  5. Polymer dispensing and embossing technology for the lens type LED packaging

    Science.gov (United States)

    Chien, Chien-Lin Chang; Huang, Yu-Che; Hu, Syue-Fong; Chang, Chung-Min; Yip, Ming-Chuen; Fang, Weileun

    2013-06-01

    This study presents a ring-type micro-structure design on the substrate and its corresponding micro fabrication processes for a lens-type light-emitting diode (LED) package. The dome-type or crater-type silicone lenses are achieved by a dispensing and embossing process rather than a molding process. Silicone with a high viscosity and thixotropy index is used as the encapsulant material. The ring-type micro structure is adopted to confine the dispensed silicone encapsulant so as to form the packaged lens. With the architecture and process described, this LED package technology herein has three merits: (1) the flexibility of lens-type LED package designs is enhanced; (2) a dome-type package design is used to enhance the intensity; (3) a crater-type package design is used to enhance the view angle. Measurement results show the ratio between the lens height and lens radius can vary from 0.4 to 1 by changing the volume of dispensed silicone. The view angles of dome-type and crater-type packages can reach 155° ± 5° and 175° ± 5°, respectively. As compared with the commercial plastic leaded chip carrier-type package, the luminous flux of a monochromatic blue light LED is improved by 15% by the dome-type package (improved by 7% by the crater-type package) and the luminous flux of a white light LED is improved by 25% by the dome-type package (improved by 13% by the crater-type package). The luminous flux of monochromatic blue light LED and white light LED are respectively improved by 8% and 12% by the dome-type package as compare with the crater-type package.

  6. Analysis of the Science and Technology Preservice Teachers' Opinions on Teaching Evolution and Theory of Evolution

    Science.gov (United States)

    Töman, Ufuk; Karatas, Faik Özgür; Çimer, Sabiha Odabasi

    2014-01-01

    In this study, we investigate of science and technology teachers' opinions about the theory of evolution and the evolution teaching. The aim of this study, we investigate of science and technology teachers' opinions about the theory of evolution and the evolution teaching. This study is a descriptive study. Open-ended questions were used to…

  7. A study on Aerosol jet printing technology in LED module manufacturing

    Science.gov (United States)

    Rudorfer, Andreas; Tscherner, Martin; Palfinger, Christian; Reil, Frank; Hartmann, Paul; Seferis, Ioannis E.; Zych, Eugeniusz; Wenzl, Franz P.

    2016-09-01

    State of the art fabrication of LED modules based on chip-on-board (COB) technology comprises some shortcomings both with respect to the manufacturing process itself but also with regard to potential sources of failures and manufacturing impreciseness. One promising alternative is additive manufacturing, a technology which has gained a lot of attention during the last years due to its materials and cost saving capabilities. Especially direct-write technologies like Aerosol jet printing have demonstrated advantages compared to other technological approaches when printing high precision layers or high precision electronic circuits on substrates which, as an additional advantage, also can be flexible and 3D shaped. Based on test samples and test structures manufactured by Aerosol jet printing technology, in this context we discuss the potentials of additive manufacturing in various aspects of LED module fabrication, ranging from the deposition of the die-attach material, wire bond replacement by printed electrical connects as well as aspects of high-precision phosphor layer deposition for color conversion and white light generation.

  8. User-led innovations and participation processes: lessons from sustainable energy technologies

    International Nuclear Information System (INIS)

    Ornetzeder, Michael; Rohracher, Harald

    2006-01-01

    In this paper we will pose the question whether a higher level of user participation could be used as a strategy to improve the development and dissemination of sustainable energy technologies. We will especially focus on user-led innovation processes with a high involvement of individual end-users. In our argument we will draw on several case studies in the field of renewable energy technologies-in particular solar collectors and biomass heating systems-and sustainable building technologies. Users in these case studies were involved in the design or planning processes, sometimes in a very selective way and with limited influence, sometimes very active and for quite a long period of time. Especially in the case of renewable energy technologies self-building groups were highly successful and resulted in improved and widely disseminated technologies. Based on the empirical results of our case studies we will critically discuss the potential of user involvement (especially in self-building groups) for the development and promotion of sustainable energy technologies and outline technological and social pre-conditions for the success of such approaches

  9. The Co-evolution of Internationalization and Technological Knowledge

    DEFF Research Database (Denmark)

    Geisler Asmussen, Christian; Hashai, Niron; Delios, Andrew

    2011-01-01

    but diminishing effect of technological knowledge on internationalization and vice versa. This relationship leads to equilibrium in the technological knowledge-internationalization space that dictates the patterns of technological and international evolution of MNEs. The model offers an integrative approach...

  10. Leaf hydraulic evolution led a surge in leaf photosynthetic capacity during early angiosperm diversification.

    Science.gov (United States)

    Brodribb, Tim J; Feild, Taylor S

    2010-02-01

    Angiosperm evolution transformed global ecology, and much of this impact derives from the unrivalled vegetative productivity of dominant angiosperm clades. However, the origins of high photosynthetic capacity in angiosperms remain unknown. In this study, we describe the steep trajectory of leaf vein density (D(v)) evolution in angiosperms, and predict that this leaf plumbing innovation enabled a major shift in the capacity of leaves to assimilate CO(2). Reconstructing leaf vein evolution from an examination of 504 angiosperm species we found a rapid three- to fourfold increase in D(v) occurred during the early evolution of angiosperms. We demonstrate how this major shift in leaf vein architecture potentially allowed the maximum photosynthetic capacity in angiosperms to rise above competing groups 140-100 Ma. Our data suggest that early terrestrial angiosperms produced leaves with low photosynthetic rates, but that subsequent angiosperm success is linked to a surge in photosynthetic capacity during their early diversification.

  11. Luminescence and the light emitting diode the basics and technology of leds and the luminescence properties of the materials

    CERN Document Server

    Williams, E W; Pamplin, BR

    2013-01-01

    Luminescence and the Light Emitting Diode: The Basics and Technology of LEDS and the Luminescence Properties of the Materials focuses on the basic physics and technology of light emitting diodes (LEDS) and pn junction lasers as well as their luminescence properties. Optical processes in semiconductors and the useful devices which can be made are discussed. Comprised of 10 chapters, this book begins with an introduction to the crystal structure and growth, as well as the optical and electrical properties of LED materials. The detailed fabrication of the LED is then considered, along with the lu

  12. Technological Evolution on Computed Tomography and Radioprotection

    International Nuclear Information System (INIS)

    Leite, Bruno Barros; Ribeiro, Nuno Carrilho

    2006-01-01

    Computed Tomography (CT) has been available since the 70s and has experienced a dramatic technical evolution. Multi-detector technology is our current standard, offering capabilities unthinkable only a decade ago. Yet, we must nor forget the ionizing nature of CT's scanning energy (X-rays). It represents the most important cause of medical-associated radiation exposure to the general public, with a trend to increase. It is compulsory to intervene with the objective of dose reduction, following ALARA policies. Currently there are some technical advances that allow dose reduction, without sacrificing diagnostic image capabilities. However, human intervention is also essential. We must keep investment on education so that CT exams are don when they are really useful in clinical decision. Alternative techniques should also be considered. Image quality must not be searched disregarding the biological effects of radiation. Generally, it is possible to obtain clinically acceptable images with lower dose protocols. (author)

  13. The evolution of silicon wafer cleaning technology

    International Nuclear Information System (INIS)

    Kern, W.

    1990-01-01

    The purity of wafer surfaces is an essential requisite for the successful fabrication of VLSI and ULSI silicon circuits. Wafer cleaning chemistry has remained essentially unchanged in the past 25 years and is based on hot alkaline and acidic hydrogen peroxide solutions, a process known as RCA Standard Clean. This is still the primary method used in the industry. What has changed is its implementation with optimized equipment:from simple immersion to centrifugal spraying, megasonic techniques, and enclosed system processing that allow simultaneous removal of both contaminant films and particles. Improvements in wafer drying by use of isopropanol vapor or by slow-pull out of hot deionized water are being investigated. Several alternative cleaning methods are also being tested, including choline solutions, chemical vapor etching, and UV/ozone treatments. The evolution of silicon wafer cleaning processes and technology is traced and reviewed

  14. A Technology Investigation Supporting Software Architecture and Analysis for Evolution

    National Research Council Canada - National Science Library

    Garlan, David

    2001-01-01

    In this report we summarize the approaches and result of the project "A Technology Investigation Supporting Software Architecture and Analysis for Evolution," carried out at Carnegie Mellon University...

  15. An Easy to Deploy Street Light Control System Based on Wireless Communication and LED Technology

    Directory of Open Access Journals (Sweden)

    Jesús Villadangos

    2013-05-01

    Full Text Available This paper presents an intelligent streetlight management system based on LED lamps, designed to facilitate its deployment in existing facilities. The proposed approach, which is based on wireless communication technologies, will minimize the cost of investment of traditional wired systems, which always need civil engineering for burying of cable underground and consequently are more expensive than if the connection of the different nodes is made over the air. The deployed solution will be aware of their surrounding’s environmental conditions, a fact that will be approached for the system intelligence in order to learn, and later, apply dynamic rules. The knowledge of real time illumination needs, in terms of instant use of the street in which it is installed, will also feed our system, with the objective of providing tangible solutions to reduce energy consumption according to the contextual needs, an exact calculation of energy consumption and reliable mechanisms for preventive maintenance of facilities.

  16. WiMAX technology and network evolution

    CERN Document Server

    Etemad, Kamran

    2010-01-01

    WiMAX, the Worldwide Interoperability for Microwave Access, represents a paradigm shift in telecommunications technology. It offers the promise of cheaper, smaller, and simpler technology compared to existing broadband options such as DSL, cable, fiber, and 3G wireless.

  17. Exploring the evolution of investment pattern on advanced manufacturing technology

    DEFF Research Database (Denmark)

    Yang, Cheng; Matthiesen, Rikke Vestergaard; Johansen, John

    2014-01-01

    This paper explores the evolution of investment pattern on advanced manufacturing technology in a manner that builds on a longitudinal perspective. Based on the data of investments in AMTs from 567 manufacturing companies this paper develops a longitudinal taxonomy defined by the evolution...... of technology management, which is comprised primarily of cross-sectional studies that do not address the dynamic nature of investments in AMTs....

  18. MANUS: the evolution of an assistive technology

    NARCIS (Netherlands)

    Verburg, G.; Kwee, H.H.; Wisaksana, A.; Cheetham, A.; Woerden, J.A. van

    1996-01-01

    Manus is a wheelchair mounted robotic arm that was designed for people who have significant impairment in function of all limbs. The process of development, user testing, and product modifications is described, with special emphasis on evaluations by consumers. After an evolution of 20 years, Manus

  19. Empathy and Dignity through Technology: Using Lifeworld-Led Multimedia to Enhance Learning about the Head, Heart and Hand

    Science.gov (United States)

    Pulman, Andy; Galvin, Kathleen; Hutchings, Maggie; Todres, Les; Quinney, Anne; Ellis-Hill, Caroline; Atkins, Peter

    2012-01-01

    A person's sense of dignity is a complex phenomenon and is intertwined with their sense of feeling human and being respected as a human being. In 2010, the School of Health and Social Care developed a collaborative lifeworld led transprofessional curriculum for health and social work disciplines harnessing technology to connect learners to a wider…

  20. [Technological evolution in the manufacting industry].

    Science.gov (United States)

    Settineri, Luca

    2011-01-01

    In this paper the 5 contemporary paradigms of the production technologies are summarised and the potential developments are examined. Further, the most advanced machining technologies are illustrated and the developments in the machine tools and in the tools that are deeply transforming the production environment, with particular reference to machining.

  1. TECHNOLOGY TRANSFER: Several Factors Have Led to a Decline in Partnerships at DOE's Laboratories

    National Research Council Canada - National Science Library

    2002-01-01

    Since 1980, the Congress has enacted several laws designed to make federally funded technology available to the public by facilitating the transfer of technology from federal laboratories to U.S. businesses...

  2. Evolution of Database Replication Technologies for WLCG

    OpenAIRE

    Baranowski, Zbigniew; Pardavila, Lorena Lobato; Blaszczyk, Marcin; Dimitrov, Gancho; Canali, Luca

    2015-01-01

    In this article we summarize several years of experience on database replication technologies used at WLCG and we provide a short review of the available Oracle technologies and their key characteristics. One of the notable changes and improvement in this area in recent past has been the introduction of Oracle GoldenGate as a replacement of Oracle Streams. We report in this article on the preparation and later upgrades for remote replication done in collaboration with ATLAS and Tier 1 databas...

  3. How to treat Alzheimer’s with new LED light technology

    DEFF Research Database (Denmark)

    Nguyen, Ngoc Mai; Petersen, Paul Michael; Broeng, Jes

    We have developed a new therapeutic LED lamp that modulates with 40 Hz the neuron responses in different parts of the brain without affecting the human vision. The lamp may in the future be used to treat patients with Alzheimer’s disease.......We have developed a new therapeutic LED lamp that modulates with 40 Hz the neuron responses in different parts of the brain without affecting the human vision. The lamp may in the future be used to treat patients with Alzheimer’s disease....

  4. Technology enabled evolutions in liquids marketing

    International Nuclear Information System (INIS)

    Manning, S.

    1998-01-01

    Deregulation, mergers, changing economic conditions, and downsizing have captured the headlines in the energy industry in recent times. To say that companies have struggled to react to these changes would be an understatement. Huge trading organizations have grown from nothing in a few years, while entire industry segments have been forced to restructure themselves. Information technology has enabled much of this change. By bringing information management out of the back office and onto the trading floors, companies have radically redesigned their work processes. The future promises even faster change, with business focus turning to innovative packaging of services with products, expanding asset bases, and reducing costs. Information technology will fuel this transformation by providing enterprise-wide trading solutions and, ultimately, linking the entire industry into a virtual supply chain. To remain competitive, companies need a strategy to manage information technology as a core asset

  5. Evolution of Database Replication Technologies for WLCG

    CERN Document Server

    Baranowski, Zbigniew; Blaszczyk, Marcin; Dimitrov, Gancho; Canali, Luca

    2015-01-01

    In this article we summarize several years of experience on database replication technologies used at WLCG and we provide a short review of the available Oracle technologies and their key characteristics. One of the notable changes and improvement in this area in recent past has been the introduction of Oracle GoldenGate as a replacement of Oracle Streams. We report in this article on the preparation and later upgrades for remote replication done in collaboration with ATLAS and Tier 1 database administrators, including the experience from running Oracle GoldenGate in production. Moreover, we report on another key technology in this area: Oracle Active Data Guard which has been adopted in several of the mission critical use cases for database replication between online and offline databases for the LHC experiments.

  6. Development of Key Technologies for White Lighting Based on Light-Emitting Diodes (LEDs)

    Energy Technology Data Exchange (ETDEWEB)

    Werner Goetz; Bill Imler; James Kim; Junko Kobayashi; Andrew Kim; Mike Krames; Rick Mann; Gerd Mueller-Mach; Anneli Munkholm; Jonathan Wierer

    2004-03-31

    This program was organized to focus on materials development issues critical to the acceleration of solid-state lighting, and was split into three major thrust areas: (1) study of dislocation density reduction for GaN grown on sapphire using 'cantilever epitaxy', and the impact of dislocation density on the performance of state-of-the-art high-power LEDs; (2) the evaluation of in situ techniques for monitoring gas phase chemistry and the properties of GaN-based layers during metal-organic vapor phase epitaxy (MOCVD), and (3) feasibility for using semiconductor nanoparticles ('quantum dots') for the down-conversion of blue or ultraviolet light to generate white light. The program included a partnership between Lumileds Lighting (epitaxy and device fabrication for high power LEDs) and Sandia National Laboratories (cantilever epitaxy, gas phase chemistry, and quantum dot synthesis). Key findings included: (1) cantilever epitaxy can provide dislocation density reduction comparable to that of more complicated approaches, but all in one epitaxial growth step; however, further improvements are required to realize significant gains in LED performance at high drive currents, (2) in situ tools can provide detailed knowledge about gas phase chemistry, and can be used to monitor and control epitaxial layer composition and temperature to provide improved yields (e.g., a fivefold increase in color targeting is demonstrated for 540nm LEDs), and (3) quantum efficiency for quantum dots is improved and maintained up to 70% in epoxy thin films, but further work is necessary to increase densification (absorption) and robustness before practical application to LEDs.

  7. Evolution of silicon sensor technology in particle physics

    CERN Document Server

    Hartmann, Frank

    2017-01-01

    This informative monograph describes the technological evolution of silicon detectors and their impact on high energy particle physics. The author here marshals his own first-hand experience in the development and also the realization of the DELPHI, CDF II and the CMS tracking detector. The basic principles of small strip- and pixel-detectors are presented and also the final large-scale applications. The Evolution of Silicon Detector Technology acquaints readers with the manifold challenges involving the design of sensors and pushing this technology to the limits. The expert will find critical information that is so far only available in various slide presentation scattered over the world wide web. This practical introduction of silicon sensor technology and its day to day life in the lab also offers many examples to illustrate problems and their solutions over several detector generations. The new edition gives a detailed overview of the silicon sensor technology used at the LHC, from basic principles to act...

  8. Social organization and the evolution of cumulative technology in apes and hominins.

    Science.gov (United States)

    Pradhan, Gauri R; Tennie, Claudio; van Schaik, Carel P

    2012-07-01

    Culturally supported accumulation (or ratcheting) of technological complexity is widely seen as characterizing hominin technology relative to that of the extant great apes, and thus as representing a threshold in cultural evolution. To explain this divide, we modeled the process of cultural accumulation of technology, which we defined as adding new actions to existing ones to create new functional combinations, based on a model for great ape tool use. The model shows that intraspecific and interspecific variation in the presence of simple and cumulative technology among extant orangutans and chimpanzees is largely due to variation in sociability, and hence opportunities for social learning. The model also suggests that the adoption of extensive allomaternal care (cooperative breeding) in early Pleistocene Homo, which led to an increase in sociability and to teaching, and hence increased efficiency of social learning, was enough to facilitate technological ratcheting. Hence, socioecological changes, rather than advances in cognitive abilities, can account for the cumulative cultural changes seen until the origin of the Acheulean. The consequent increase in the reliance on technology could have served as the pacemaker for increased cognitive abilities. Our results also suggest that a more important watershed in cultural evolution was the rise of donated culture (technology or concepts), in which technology or concepts was transferred to naïve individuals, allowing them to skip many learning steps, and specialization arose, which allowed individuals to learn only a subset of the population's skills. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-01

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

  10. Avalanche-mode silicon LEDs for monolithic optical coupling in CMOS technology

    NARCIS (Netherlands)

    Dutta, Satadal

    2017-01-01

    Complementary Metal-Oxide-Semiconductor (CMOS) integrated circuit (IC) technology is the most commercially successful platform in modern electronic and control systems. So called "smart power" technologies such as Bipolar CMOS DMOS (BCD), combine the computational power of CMOS with high voltage

  11. [Study of the effect of fluoride removal agent and microabrasion technology in LED teeth whitening of dental fluorosis].

    Science.gov (United States)

    Jia, Yan; Zhang, Rong; Luo, Hong-Xia; Li, Ping; Zhang, Chun-Lei

    2016-10-01

    To evaluate the effect of fluoride removal agent and microabrasion technology in LED teeth whitening of dental fluorosis. One hundred and twelve patients with moderate dental fluorosis treated from August 2012 to July 2015 were divided into experimental group and control group according to random number table, with 61 cases in each group. In addition to pretreatment for all patients, patients in the control group were given combined treatment of Beyond LED whitening and fluoride removal agent; while patients in the experimental group were given microabrasion before LED whitening, with the same subsequent treatment process as that in the control group. The whitening effect and tooth sensitivity during whitening were compared between the two groups at the completion of treatment, 1 month and 6 months after treatment. SPSS 19.0 software package was employed for statistical analysis. There were no ineffective or lost patients in 2 groups. The effective rate of whitening for patients in the experimental group at completion of treatment, 1 month and 6 months after treatment was significantly higher than that in the control group (P0.05). Combined treatment with fluoride removal agent and microabrasion technology in LED teeth whitening for dental fluorosis can significantly improve the whitening effect and will not interfered by significantly increased tooth sensitivity.

  12. Hunting shot – evolution of manufacturing technology

    Directory of Open Access Journals (Sweden)

    Piotr Bochyński

    2016-09-01

    Full Text Available Hunting shot are 1.2–10 mm diameter balls, usually made of lead alloys, forming a cluster projectile used in smoothbore hunting shotguns. Shot may also be used in pistol and revolver ammunition, in which it can constitute structural element of the projectile. Shot pellets may also be made of other materials and have other shapes. The aim of this paper is to aggregate information on the topic available from a number of different sources. It is hoped that such information will be useful for forensic ballistics experts. Historical development of pellets and their manufacturing technology from the 15th century is presented.

  13. Evaluation of LED Sign Technology at a Passive Highway-Rail Grade Crossing

    Science.gov (United States)

    2016-02-01

    The U.S. Department of Transportations (DOT) John A. Volpe National Transportation Systems Center (Volpe Center), under the direction of DOTs Federal Railroad Administration (FRA) Office of Research, Development, and Technology (ORD), conducted...

  14. Evolution of silicon sensor technology in particle physics

    CERN Document Server

    AUTHOR|(CDS)2069083

    2009-01-01

    This informative monograph describes the technological evolution of silicon detectors and their impact on high- energy particle physics. The author here marshals his own first-hand experience in the development and also the realization of the DELPHI, CDF II and the CMS tracking detector. The basic principles of small strip- and pixel-detectors are presented and also the final large-scale applications. The Evolution of Silicon Detector Technology acquaints readers with the manifold challenges involving the design of sensors and pushing this technology to the limits. The expert will find critical information that is so far only available in various slide presentation scattered over the world wide web. This practical introduction of silicon sensor technology and its day to day life in the lab also offers many examples to illustrate problems and their solutions over several detector generations.

  15. Portable plant chlorophyll fluorimeter based on blue LED rapid induced technology

    Science.gov (United States)

    Zheng, Yibo; Mi, Ting; Zhang, Lei; Zhao, Jun

    2018-01-01

    Fluorimeter is an effective device for detecting chlorophyll a content in plants. In order to realize real-time nondestructive detection of plant blades, a camera based fluorescence instrument based on two color mirrors has been developed. The blue light LED is used as the excitation light source, and the lens is used for shaping and focusing the excitation light to ensure the excitation intensity and uniform illumination of the light source. The device uses a 45 degree two color mirror to separate the chlorophyll a excited light path and the fluorescence receiving light path. Finally, the fluorescent signal is collected by the silicon photocell, and the signal is processed by the circuit to transmit the digital information to the display. Through the analysis of the experimental data, the device has the advantages of small size, easy to carry, fast induction, etc., and can be widely applied in outdoor teaching and field investigation.

  16. Deviation Among Technology Reviews: An Informative Enrichment of Technology Evolution Theory for Marketing

    NARCIS (Netherlands)

    A. Sood (Ashish); S. Stremersch (Stefan)

    2010-01-01

    textabstractUnderstanding technological change is of critical importance to marketers, as it bears new markets, new brands, new customers, and new market leaders. This paper examines the deviation among reviews of a technology’s performance and its consequences for inferences on technology evolution

  17. The evolution of a company based on technological innovation. Gamesa

    International Nuclear Information System (INIS)

    Lopez Mielgo, N.

    2007-01-01

    This paper reviews the evolution of a company that has based its competitive strategy on technological innovation. Gamesa was established in 1976 and it has been continuously transforming its portfolio of businesses until it has become one of the main global operators in the field of wind turbine manufacturing. The firm was able to apply its technological capital in the emerging phase of the domestic wind energy industry. Once leadership in Spain was consolidated, Gamesa has developed an ambitious programme of sales and operational internationalisation, which has converted it in the number two producer of wind turbines worldwide. (Author)

  18. Evolution of Water Supply, Sanitation, Wastewater, and Stormwater Technologies Globally

    Directory of Open Access Journals (Sweden)

    Andreas N. Angelakis

    2015-02-01

    Full Text Available This paper provides an outline of history of hydro-technologies in the west and the east. It is an overview of the special issue on “the evolution of hydro-technologies globally”, in which the key topics regarding the history of water and sanitation worldwide, and its importance to future cities are presented and discussed. It covers a wide range of relevant historical issues, and is presented in three categories: productivity assessment, institutional framework and mechanisms, and governance aspects. This paper concludes by discussing the challenges on future research in this field of study.

  19. From Darwinian to technological evolution: forgetting the human lottery.

    Science.gov (United States)

    Tintino, Giorgio

    2014-01-01

    The GRIN technologies (-geno, -robo, -info, -nano) promise to change the inner constitution of human body and its own existence. This transformation involves the structure of our lives and represent a brave new world that we have to explore and to manage. In this sense, the traditional tools of humanism seems very inadequate to think the biotech century and there is a strong demand of a new thought for the evolution and the concrete history of life. The posthuman philosophy tries to take this new path of human existence in all of its novelty since GRIN technologies seem to promise new and unexpected paths of evolution to living beings and, above all, man. For this, the post-human thought, as we see, is a new anthropological overview on the concrete evolution of human being, an overview that involves an epistemological revolution of the categories that humanism uses to conceptualize the journey that divides the Homo sapiens from the man. But, is this right?

  20. Sustainable Data Evolution Technology for Power Grid Optimization

    Energy Technology Data Exchange (ETDEWEB)

    2017-10-09

    The SDET Tool is used to create open-access power grid data sets and facilitate updates of these data sets by the community. Pacific Northwest National Laboratory (PNNL) and its power industry and software vendor partners are developing an innovative sustainable data evolution technology (SDET) to create open-access power grid datasets and facilitate updates to these datasets by the power grid community. The objective is to make this a sustained effort within and beyond the ARPA-E GRID DATA program so that the datasets can evolve over time and meet the current and future needs for power grid optimization and potentially other applications in power grid operation and planning.

  1. The evolution of telemedicine and nano-technology

    Science.gov (United States)

    Park, Dong Kyun; Young Jung, Eun; Chan Moon, Byung

    2012-10-01

    This paper will cover definition and history of telemedicine, changes in medical paradigm and roll of telemedicine and roll of nano-technology for evolution of telemedicine. Hypothetically, telemedicine is distance communication for medical purpose and modern definition explains telemedicine as `a system of health care delivery in which physicians examine distant patients through the use of telecommunications technology. Medical service will change to personalized medicine based on gene information to prevent and manage diseases due to decrease of acute diseases, population aging and increase of prevalence in chronic diseases, which means current medical services based on manualized treatment for diseases will change to personalized medicine based on individual gene information. Also, international healthcare will be activated to provide high quality medical services with low cost using developed transportation. Moreover, hospital centered medical services will change to patients centered medical service due to increase of patient's rights. Development in sensor technology is required for telemedicine to be applied as basic infrastructure for medical services. Various researches in nano-biosensor field are conducted due to introduction of new technologies. However, most researches are in fundamental levels that requires more researches for stability and clinical usefulness. Nano technology is expected to achieve innovative development and define new criteria for disease prevention and management.

  2. An Overview on Wireless Sensor Networks Technology and Evolution

    Directory of Open Access Journals (Sweden)

    Chiara Buratti

    2009-08-01

    Full Text Available Wireless sensor networks (WSNs enable new applications and require non-conventional paradigms for protocol design due to several constraints. Owing to the requirement for low device complexity together with low energy consumption (i.e., long network lifetime, a proper balance between communication and signal/data processing capabilities must be found. This motivates a huge effort in research activities, standardization process, and industrial investments on this field since the last decade. This survey paper aims at reporting an overview of WSNs technologies, main applications and standards, features in WSNs design, and evolutions. In particular, some peculiar applications, such as those based on environmental monitoring, are discussed and design strategies highlighted; a case study based on a real implementation is also reported. Trends and possible evolutions are traced. Emphasis is given to the IEEE 802.15.4 technology, which enables many applications of WSNs. Some example of performance characteristics of 802.15.4-based networks are shown and discussed as a function of the size of the WSN and the data type to be exchanged among nodes.

  3. The evolution of wireless video transmission technology for surveillance missions

    Science.gov (United States)

    Durso, Christopher M.; McCulley, Eric

    2012-06-01

    Covert and overt video collection systems as well as tactical unmanned aerial vehicles (UAV's) and unmanned ground vehicles (UGV's) can deliver real-time video intelligence direct from sensor systems to command staff providing unprecedented situational awareness and tactical advantage. Today's tactical video communications system must be secure, compact, lightweight, and fieldable in quick reaction scenarios. Four main technology implementations can be identified with the evolutionary development of wireless video transmission systems. Analog FM led to single carrier digital modulation, which gave way to multi-carrier orthogonal modulation. Each of these systems is currently in use today. Depending on the operating environment and size, weight, and power limitations, a system designer may choose one over another to support tactical video collection missions.

  4. Diversification of a Transcription Factor Family Led to the Evolution of Antagonistically Acting Genetic Regulators of Root Hair Growth.

    Science.gov (United States)

    Breuninger, Holger; Thamm, Anna; Streubel, Susanna; Sakayama, Hidetoshi; Nishiyama, Tomoaki; Dolan, Liam

    2016-06-20

    Streptophytes colonized the land some time before 470 million years ago [1-3]. The colonization coincided with an increase in morphological and cellular diversity [4-7]. This increase in diversity is correlated with a proliferation in transcription factors encoded in genomes [8-10]. This suggests that gene duplication and subsequent diversification of function was instrumental in the generation of land plant diversity. Here, we investigate the diversification of the streptophyte-specific Lotus japonicus ROOTHAIRLESS LIKE (LRL) transcription factor (TF) [11, 12] subfamily of basic loop helix (bHLH) proteins by comparing gene function in early divergent and derived land plant species. We report that the single Marchantia polymorpha LRL gene acts as a general growth regulator required for rhizoid development, a function that has been partially conserved throughout multicellular streptophytes. In contrast, the five relatively derived Arabidopsis thaliana LRL genes comprise two antagonistically acting groups of differentially expressed genes. The diversification of LRL genes accompanied the evolution of an antagonistic regulatory element controlling root hair development. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. The cost of radiotherapy in a decade of technology evolution

    International Nuclear Information System (INIS)

    Van de Werf, Evelyn; Verstraete, Jan; Lievens, Yolande

    2012-01-01

    Purpose: To quantify changes in radiotherapy costs occurring in a decade of medical–technological evolution. Materials and methods: The activity-based costing (ABC) model of University Hospitals Leuven (UHL) radiotherapy (RT) department was adapted to current RT standards. It allocated actual resource costs to the treatments based on the departmental work-flow and patient mix in 2009. A benchmark with the former model analyzed the cost increases related to changes in RT infrastructure and practice over 10 years. Results: A considerable increase in total RT costs was observed, resulting from higher capital investments (96%) and personnel cost (103%), the latter dominating the total picture. Treatment delivery remains the most costly activity, boosted by the cost of improved quality assurance (QA), 23% of total product costs, coming along with more advanced RT techniques. Hence, cost increases at the product level are most obvious for complex treatments, such as intensity-modulated radiotherapy (IMRT), representing cost increases ranging between 38% and 88% compared to conformal approaches. Conclusions: The ABC model provides insight into the financial consequences of evolving technology and practice. Such data are a mandatory first step in our strive to prove RT cost-effectiveness and thus support optimal reimbursement and provision of radiotherapy departments.

  6. Technology for Space Station Evolution. Volume 3: EVA/Manned Systems/Fluid Management System

    Science.gov (United States)

    1990-01-01

    NASA's Office of Aeronautics and Space Technology (OAST) conducted a workshop on technology for space station evolution 16-19 Jan. 1990 in Dallas, Texas. The purpose of this workshop was to collect and clarify Space Station Freedom technology requirements for evolution and to describe technologies that can potentially fill those requirements. These proceedings are organized into an Executive Summary and Overview and five volumes containing the Technology Discipline Presentations. Volume 3 consists of the technology discipline sections for Extravehicular Activity/Manned Systems and the Fluid Management System. For each technology discipline, there is a Level 3 subsystem description, along with the papers.

  7. LED roadway luminaires evaluation.

    Science.gov (United States)

    2012-02-01

    This research explores whether LED roadway luminaire technologies are a viable future solution to providing roadway lighting. Roadway lighting : enhances highway safety and traffic flow during limited lighting conditions. The purpose of this evaluati...

  8. Patterns of technological innovation and evolution in the energy sector: A patent-based approach

    International Nuclear Information System (INIS)

    Lee, Kyungpyo; Lee, Sungjoo

    2013-01-01

    Given the ever-increasing pace and complexity of technological innovation in the energy sector, monitoring technological changes has become of strategic importance. One of the most common techniques for technology monitoring is patent analysis, which enables the identification of technological trends over time. However, few previous studies have carried out patent analysis in the energy sector. This study aims to explore patterns of innovation and of evolution in energy technologies, particularly focusing on similarities and differences across technologies. For this purpose, we first defined the relevant energy technologies and extracted the associated patent data from the United States Patents and Trademark Office (USPTO) and then adopted six patent indices and developed six patent maps to analyze their innovation characteristics. We then clustered energy technologies with similar characteristics, so defining innovation categories, and analyzed the changes in these characteristics over time to define their evolution categories. As one of the few attempts to investigate the overall trends in the energy sector's innovation and evolution, this study is expected to help develop an in-depth understanding of the energy industry, which will be useful in establishing technology strategies and policy in this rapidly changing sector. - Highlights: • We examined the patterns of innovation and evolution of energy technologies. • Six types of innovation patterns such as “competitive” or “mature” were identified. • Six types of evolution patterns such as “towards closed innovation” were identified. • The patterns of evolution were related to the patterns of innovation

  9. LED lamp

    Science.gov (United States)

    Galvez, Miguel; Grossman, Kenneth; Betts, David

    2013-11-12

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

  10. Large area LED package

    Science.gov (United States)

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

    2015-03-01

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

  11. The evolution of the laser: A systems perspective on science, technology and society

    Science.gov (United States)

    Deruiter, Willem

    The evolution of laser technology is addressed, and an attempt is made to correlate this evolution to the macrosociological theory of Juergen Habermas. The economic and social consequences of innovations are evaluated. Different laser applications are described. The evolution of the semiconductor laser is discussed. The evolution of optical telecommunication systems is outlined. The Habermas theory of communicative action, focussing on the theoretical distinction between 'system' and 'lifeworld,' is treated. The modified theory of Habermas is applied to the evolution of the laser. The embedding of a number of laser applications in the social context is discussed: laser isotope separation, compact disc players, and the Strategic Defense Initiative.

  12. Inventive processes in nature: from information origin in chemical evolution to technological exhaustion

    Directory of Open Access Journals (Sweden)

    Aleš Kralj

    2017-08-01

    Full Text Available Abstract It has been ten years since the 2006 work of Abel and Trevors wherein the cybernetic path of life’s origin was proposed as an alternative to the widely held views of such origin being self-ordering and self-organisation. Cybernetic adaptation is now recognised as a cornerstone of biological and technological evolution and as well as of artificial intelligence (AI and cognition. It is expected that chemical evolution, preceding biological evolution, will have a cybernetic explanation as well. Among all evolutions, only AI evolutionary computation and cognition are accessible via the scientific method. For biological and technological evolutions, we only have the example of one, while for chemical evolution we have no template at all. The aim of this essay is to look for commonalities in all evolutions and attempt to fill in the missing pieces of the chemical and technological evolutions with knowledge that can be obtained by observing evolutions with a complete record. Types of information – quantum, chemical and functional – are defined, and their roles explained. It is proposed that the temporal survivability of information should be considered as a factor of general evolutionary fitness for all evolutionary adaptations. This study further suggests that because all experimentation spaces are finite they may become exhausted due to convergence towards optimal configurations. Such exhaustion of important experimental areas might reflect the observed decay of technological innovation and economic growth.

  13. Self-reported Impacts of LED Lighting Technology Compared to Fuel-based Lighting on Night Market Business Prosperity in Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, Peter; Jacobson, Arne; Mills, Evan; Mumbi, Maina

    2009-02-11

    The notion of"productive use" is often invoked in discussions about whether new technologies improve productivity or otherwise enhance commerce in developing-country contexts. It an elusive concept,especially when quantitative measures are sought. Improved and more energy efficient illumination systems for off-gridapplication--the focus of the Lumina Project--provide a case in which a significant productivity benefit can be imagined, given the importance of light to the successful performance of many tasks, and the very low quality of baseline illumination provided by flame-based source. This Research Note summarizes self-reported quantitative and qualitative impacts of switching to LED lighting technology on the prosperity of night-market business owners and operators. The information was gathered in the context of our 2008 market testing field work in Kenya?s Rift Valley Province, which was performed in the towns of Maai Mahiu and Karagita by Arne Jacobson, Kristen Radecsky, Peter Johnstone, Maina Mumbi, and others. Maai Mahiu is a crossroads town; provision of services to travelers and freight carriers is a primary income source for the residents. In contrast, the primary income for Karagita's residents is from work in the large, factory style flower farms on the eastern shores of Lake Naivasha that specialize in producing cut flowers for export to the European market. According to residents, both towns had populations of 6,000 to 8,000 people in June 2008. We focused on quantifying the economics of fuel-based and LED lighting technology in the context of business use by night market vendors and shop keepers. Our research activities with the business owners and operators included baseline measurement of their fuel-based lighting use, an initial survey, offering for sale data logger equipped rechargeable LED lamps, monitoring the adoption of the LED lamps, and a follow-up survey.

  14. New Model of Evolution of Technologies and Prospects of Research With Using Big Data

    Directory of Open Access Journals (Sweden)

    Sergey Krichevsky

    2016-10-01

    Full Text Available In order to create the adequate technical picture of the world we need the new comprehension, the new models of evolution of technology and technosphere, and the new tools of perception, fixation and interpretation of the artefacts of the technical reality. A new interpretation of the notion «technological mode», which is the key in this article is suggested. Technological mode is the order of the existence and the activity of the society with the application of a number of mutually connected technologies, in the format of socio-techno-natural system, in the interaction with the environment, with the coverage of socio-eco-economic aspects. A new model of the evolution of technologies in the global paradigm of the global future and «green» development has been developed. The model shows: 1 the accelerated growth and the estimation of the total number of technologies; 2 1st - 7th technological modes (including the promising «green» as the rising levels of the integral technological way, inscribed in the Snooks-Panov’s hyperbolic curve, which reflects the process of evolution on the Earth with a singularity ~ in 2045 (forecast; 3 before-singular as well as post-singular migration options and global future; 4 a hypothetical post-singular 8th technological mode. As a new tool, it is proposed to use Big Data for the research of the nonlinear global process of evolution of technologies, technological modes, and the technosphere for the purpose of the analysis, forecast and management. The idea and the foundations of the concept of a new international mega-project «Big data for research of the evolution of technologies» are also stated.

  15. Where Creativity Meets Technology: A Library-Led, Multi-Disciplinary Online Showcase for Artworks, Creative Writings, and Movies Displayed with 3D and HTML5 Technology

    Science.gov (United States)

    Wong, Shun Han Rebekah

    2015-01-01

    This article introduces the Hong Kong Baptist University's Heritage project (http://heritage.lib.hkbu.edu.hk/), a multi-disciplinary online showcase for curriculum-related creative outputs that were produced by faculty and students of the university. Initiated and led by the University Library, this project was a collaborative effort with six…

  16. The technological evolution of psychological operations throughout history

    CSIR Research Space (South Africa)

    Mouton, Francois

    2016-07-01

    Full Text Available Psychological operations or PsyOps is a multi-disciplinary capability that requires technology in the social sciences, as well as in areas of design, Information and Communication Technology (ICT), electronics, broadcasting and printing. It has been...

  17. The Evolution of Technology: Landmarking Australian Secondary School Music

    Science.gov (United States)

    Crawford, Renée

    2014-01-01

    This paper will provide an overview of the history of the inclusion of technology in Australian education with a focus on music education. There will be a discussion of some of the arguments for its inclusion and how these may have changed over time. Technology has always been actively present in music and its practice. However, it was through…

  18. Mapping the (R-)Evolution of Technological Fields

    DEFF Research Database (Denmark)

    Jurowetzki, Roman; Hain, Daniel S.

    2014-01-01

    use the broad area of Technological Singularity, an umbrella term for different technologies ranging from neuroscience to machine learning and bioengineering, which are seen as main contributors to the development of artificial intelligence and human enhancement technologies. Using a socially enhanced......The aim of this paper was to provide a framework and novel methodology geared towards mapping technological change in complex interdependent systems by using large amounts of unstructured data from various recent on- and offline sources. Combining techniques from the fields of natural language...... processing and network analysis, we are able to identify technological fields as overlapping communities of knowledge fragments. Over time persistence of these fragments allows to observe how these fields evolve into trajectories, which may change, split, merge and finally disappear. As empirical example we...

  19. Light Emitting Diodes (LEDs)

    Science.gov (United States)

    1997-01-01

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

  20. Advanced technologies for plant cell wall evolution and diversity

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik

    Plant cell walls consist of polysaccharides, glycoproteins and phenolic polymers interlinked together in a highly complex network. The detailed analysis of cell walls is challenging because of their inherent complexity and heterogeneity. Also, complex carbohydrates, unlike proteins and nucleotide...... angiosperms. This analysis has enabled cell wall diversity to be placed in a phylogenetic context, and, when integrated with transcriptomic and genomic analysis has contributed to our understanding of important aspects of plant evolution....... produced has provided new insight into cell wall evolution and biosynthesis and has contributed to the commercial development of cell wall materials. A major focus of the work has been the wide scale sampling of cell wall diversity across the plant kingdom, from unicellular algae to highly evolved...

  1. Evolution of scientific and technological documentation services at ENEA

    International Nuclear Information System (INIS)

    Sano, A.; Li Puma, G.

    1990-05-01

    The expected evolution of documentation and information Centers in research Organizations is presented, on the base of experience matured at ENEA (Italy) in this field. The growth of the available information, consequent to the integration of different information systems, to the realization of library network, to the increase of on-line data bases, the evolution of interfaces between information and users, and the growth of the capacity of Centers to understand in depth the information they manage (capability to analyse, validate and elaborate the data), represents the main aspects of the evolution of this sector. The role of Centers is then changing shifting gradually from the management of documentation to the management of information. New professional skills are therefore necessary in the Centers. Competences in computer science and in other areas of major interest to the Organization are requested. In this way the Centers tend to become an active information point reference in the life of the Organization and have a specific role of notable interest and responsibility. (author). 3 figs

  2. The Spiritual Meaning of Technological Evolution to Life

    Directory of Open Access Journals (Sweden)

    Joseph Morrill Kirby

    2013-07-01

    Full Text Available There are two senses by which technology can be seen as a new layer of living complexity: first, while biological systems can only appropriate 24 of the 91 natural elements into their metabolic processes, technological systems can imbue complex form into all 91 elements; second, this added capacity gives life the potential to expand across its current limit – the atmosphere of the Earth – in the same way as it expanded from the oceans to the land some five hundred million years ago. This essay explores what such an understanding of life and technology might mean to us, humanity, in the context of our current ecological and social catastrophe.

  3. Energy perspectives of France by 2020-2050. Technological evolutions

    International Nuclear Information System (INIS)

    2007-09-01

    The different technologies in phase of research and development and concerning the energy production or storage, are examined and presented in function of their probability of emergence at the industrial level: the projects which are going to appear in planed time on the market, the projects based on known technologies which should appear but at non predicted date and the possible projects but based on a new technology. The different type of energy, from the fossil fuels to the renewable energies are concerned. (A.L.B.)

  4. Dental technology over 150 years: evolution and revolution.

    Science.gov (United States)

    Feuerstein, Paul

    2014-01-01

    A patient entering a dental office is often greeted and then checked in through the practice management system's digital appointment book. The provider is notified by an electronic signal that is visual, audible, or both. The patient is led to the treatment area and sits in a dental chair which is adjusted to the individual's size and position for the treatment, and the light is positioned. Sometimes a radiograph is taken, local anesthetic is delivered, and a handpiece--air turbine or electric--is used for the procedure. How different is this process today from a dentist treating a patient in 1864?

  5. Light Emitting Diode (LED)

    Science.gov (United States)

    1997-01-01

    A special lighting technology was developed for space-based commercial plant growth research on NASA's Space Shuttle. Surgeons have used this technology to treat brain cancer on Earth, in two successful operations. The treatment technique called photodynamic therapy, requires the surgeon to use tiny pinhead-size Light Emitting Diodes (LEDs) (a source releasing long wavelengths of light) to activate light-sensitive, tumor-treating drugs. Laser light has been used for this type of surgery in the past, but the LED light illuminates through all nearby tissues, reaching parts of a tumor that shorter wavelengths of laser light carnot. The new probe is safer because the longer wavelengths of light are cooler than the shorter wavelengths of laser light, making the LED less likely to injure normal brain tissue near the tumor. It can also be used for hours at a time while still remaining cool to the touch. The LED probe consists of 144 tiny pinhead-size diodes, is 9-inches long, and about one-half-inch in diameter. The small balloon aids in even distribution of the light source. The LED light source is compact, about the size of a briefcase, and can be purchased for a fraction of the cost of a laser. The probe was developed for photodynamic cancer therapy by the Marshall Space Flight Center under a NASA Small Business Innovative Research program grant.

  6. International trade, technological change and evolution of work market

    International Nuclear Information System (INIS)

    Cacciotti, M.

    1999-01-01

    The report estimates the historic series of wages and employment depending on the average unit value of importation prices in the most important european countries, Italy, France and Germany for the years 1988-1996. Results shows that in the traditional sectors, with unskilled employment are negative influenced by international trade, otherwise, in the technological advanced sectors, influenced are to be considered positive [it

  7. Information Technology and the Evolution of the Library

    Science.gov (United States)

    2009-03-01

    access through LDAP authentication, CAC login, and other single-sign-on technologies (The Defense Technical Information Center, 2008). In providing its...Consumers: All Mgmt: WSU manages content, OhioLINK the system Moderated through staff, eventually LDAP for submission and lib staff review

  8. School Librarians as Technology Leaders: An Evolution in Practice

    Science.gov (United States)

    Wine, Lois D.

    2016-01-01

    The role of school librarians has a history of radical change. School librarians adapted to take on responsibility for technology and audio-visual materials that were introduced in schools in earlier eras. With the advent of the Information Age in the middle of the 20th century and the subsequent development of personal computers and the Internet,…

  9. Football on television: technological evolution and entertainment language

    Directory of Open Access Journals (Sweden)

    Igor José Siquieri Savenhago

    2011-04-01

    Full Text Available The first broadcast of a World Cup footballon television, to Brazil was in 1970, via Embratel. Before that, the people followed the games of the Brazilian team on the radio. Gradually, the owners of television networks realized that football could generate good financial results, with the exposing of advertisements during the broadcasts, similar to what was already done on the radio. Thus, the television, focused on the growth of audience and number of advertisers, covered football with a language of entertainment. The narration of the matches, in which the figure of the narrator is more like that of an entertainer, and improvement of the transmission technologies that improve the image quality every day, take away from football the characteristic of being just a sport to occupy the place of an entertainment. In this context, the sport becomes an article of purchase and sale. The purpose of this study is to demonstrate how this entertainment language was made up on Brazilian television, based on the broadcast sports, especially football, and like the television, which represented a technological leapin the country over the radio, assumed of the sport, country’s most popular as a commodity, interfering with the dynamics of Brazilian society. Finally, an attempt to understand how the researches that allow a technological development change behaviors and vice versa, that is, how the demands of society lead to a race to develop new technologies.

  10. Maintaining a system subject to uncertain technological evolution

    International Nuclear Information System (INIS)

    Nguyen, T.P.K.; Castanier, Bruno; Yeung, Thomas G.

    2014-01-01

    Maintenance decisions can be directly affected by the introduction of a new asset on the market, especially when the new asset technology could increase the expected profit. However new technology has a high degree of uncertainty that must be considered such as, e.g., its appearance time on the market, the expected revenue and the purchase cost. In this way, maintenance optimization can be seen as an investment problem where the repair decision is an option for postponing a replacement decision in order to wait for a potential new asset. Technology investment decisions are usually based primarily on strategic parameters such as current probability and expected future benefits while maintenance decisions are based on “functional” parameters such as deterioration levels of the current system and associated maintenance costs. In this paper, we formulate a new combined mathematical optimization framework for taking into account both maintenance and replacement decisions when the new asset is subject to technological improvement. The decision problem is modelled as a non-stationary Markov decision process. Structural properties of the optimal policy and forecast horizon length are then derived in order to guarantee decision optimality and robustness over the infinite horizon. Finally, the performance of our model is highlighted through numerical examples

  11. Stage Evolution of Office Automation Technological Change and Organizational Learning.

    Science.gov (United States)

    Sumner, Mary

    1985-01-01

    A study was conducted to identify stage characteristics in terms of technology, applications, the role and responsibilities of the office automation organization, and planning and control strategies; and to describe the respective roles of data processing professionals, office automation analysts, and users in office automation systems development…

  12. Evolution of health technology assessment: best practices of the pan-Canadian Oncology Drug Review

    Directory of Open Access Journals (Sweden)

    Rocchi A

    2015-06-01

    Full Text Available Angela Rocchi,1 Isabelle Chabot,2 Judith Glennie3 1Athena Research Inc., Burlington, ON, 2EvAccess Inc., Vaudreuil-Dorion, QC, 3JL Glennie Consulting Inc., Aurora, ON, Canada Background: In 2007, Canada chose to develop a separate and distinct path for oncology drug health technology assessment (HTA. In 2013, the decision was made to transfer the pan-Canadian Oncology Drug Review (pCODR to the Canadian Agency for Drugs and Technologies in Health (CADTH, to align the pCODR and CADTH Common Drug Review processes while building on the best practices of both. The objective of this research was to conduct an examination of the best practices established by the pCODR. Methods: A qualitative research approach was taken to assess the policies, processes, and practices of the pCODR, based on internationally accepted best practice “principles” in HTA, with a particular focus on stakeholder engagement. Publicly available information regarding the approach of the pCODR was used to gauge the agency's performance against these principles. In addition, stakeholder observations and real-world experiences were gathered through key informant interviews to be inclusive of perspectives from patient advocacy groups, provincial and/or cancer agency decision-makers, community and academic oncologists, industry, expert committee members, and health economists. Results: This analysis indicated that, through the pCODR, oncology stakeholders have had a voice in and have come to trust the quality and relevance of oncology HTA as a vital tool to ensure the best decisions for Canadians with cancer and their health care system. It could be expected that adoption of the principles and processes of the pCODR would bring a similar level of engagement and trust to other HTA organizations in Canada and elsewhere. Conclusion: The results of this research led to recommendations for improvement and potential extrapolation of these best practices to other HTA organizations

  13. The evolution of waste management processes and technologies in BNFL

    International Nuclear Information System (INIS)

    Asquith, R.W.; Fairhall, G.A.

    1997-01-01

    The treatment of wastes arising from BNFL''s nuclear fuel cycle operations can be traced through a number of phases. The first was the development of vitrification and cementation for fresh arisings. Plants utilising these technologies are now in operation. To handle the mixed, heterogeneous intermediate level wastes, retrieval, segregation and robust treatment processes are at an advanced stage of development, with all plants to be operational from 2002. BNFL is focusing attention on reducing waste management lifetime costs including reducing waste volumes of source. Technologies aimed at significant reductions are now being developed. The final phase, now in progress, recognizes the need for an integrated approach to advanced fuel cycle processes which incorporates BNFL''s holistic concept. (author)

  14. Adder : A new model for simulating the evolution of technology, with observations on why perfectly knowledgeable agents cannot launch technological revolutions

    NARCIS (Netherlands)

    Korhonen, J.M.; Kasmire, J.

    2012-01-01

    Computer simulations are increasingly used to study the development, adoption, and evolution of technologies. However, existing models suffer from various drawbacks that may not be easily corrected, among them lack of internal structure in technologies, static environments and practical difficulties

  15. 28 June 2012 - Members of the European Brain Council led by President Mary Baker visiting the LHC tunnel at Point 5 with Technology Department Group Leader L. Bottura and CMS experimental area with Run Coordinator M. Chamizo-Llatas.

    CERN Multimedia

    Jean-Claude Gadmer

    2012-01-01

    28 June 2012 - Members of the European Brain Council led by President Mary Baker visiting the LHC tunnel at Point 5 with Technology Department Group Leader L. Bottura and CMS experimental area with Run Coordinator M. Chamizo-Llatas.

  16. Evolution of health technology assessment: best practices of the pan-Canadian Oncology Drug Review.

    Science.gov (United States)

    Rocchi, Angela; Chabot, Isabelle; Glennie, Judith

    2015-01-01

    In 2007, Canada chose to develop a separate and distinct path for oncology drug health technology assessment (HTA). In 2013, the decision was made to transfer the pan-Canadian Oncology Drug Review (pCODR) to the Canadian Agency for Drugs and Technologies in Health (CADTH), to align the pCODR and CADTH Common Drug Review processes while building on the best practices of both. The objective of this research was to conduct an examination of the best practices established by the pCODR. A qualitative research approach was taken to assess the policies, processes, and practices of the pCODR, based on internationally accepted best practice "principles" in HTA, with a particular focus on stakeholder engagement. Publicly available information regarding the approach of the pCODR was used to gauge the agency's performance against these principles. In addition, stakeholder observations and real-world experiences were gathered through key informant interviews to be inclusive of perspectives from patient advocacy groups, provincial and/or cancer agency decision-makers, community and academic oncologists, industry, expert committee members, and health economists. This analysis indicated that, through the pCODR, oncology stakeholders have had a voice in and have come to trust the quality and relevance of oncology HTA as a vital tool to ensure the best decisions for Canadians with cancer and their health care system. It could be expected that adoption of the principles and processes of the pCODR would bring a similar level of engagement and trust to other HTA organizations in Canada and elsewhere. The results of this research led to recommendations for improvement and potential extrapolation of these best practices to other HTA organizations worldwide, along with suggestions for continued evolution of the pCODR in conjunction with its integration into the CADTH. It is clear that the transition of the pCODR to CADTH provides an opportunity for practices initiated by the pCODR to

  17. The evolution of waste management processes and technologies in BNFL

    International Nuclear Information System (INIS)

    Asquith, R. W.; Fairhall, G. A.

    1997-01-01

    The treatment of wastes arising from BNFL's nuclear fuel cycle operations can be traced through a number of phases. The first was the development of vitrification and cementation for fresh arising and plants are now in operation. To handle the mixed, heterogeneous intermediate level wastes, retrieval, segregation and robust treatment processes are at an advanced stage of development, with all plants to be operational from 2002. BNFL is focusing attention on reducing waste management lifetime costs including reducing waste volumes of source. Technologies aimed at significant reductions are now being developed. The final phase, now in progress, recognizes the need for an integrated approach to advanced fuel cycle processes which incorporates BNFL holistic concept. (author) 6 refs., 1 fig

  18. Programmed Instruction to Computer-Based Instruction: The Evolution of an Instructional Technology.

    Science.gov (United States)

    Lamos, Joseph P.

    This review of the evolution of programmed instruction from Pressey and Skinner to the present suggests that current computer technology will be able to free the learner from the limitations of time and place as Pressey originally proposed. It is noted that Skinner provided the necessary foundation for treating the learning process on an…

  19. Radio frequency for particle accelerators: evolution and anatomy of a technology

    CERN Document Server

    Vretenar, M

    2011-01-01

    This introductory lecture outlines the impressive progress of radio frequency technology, from the first table-top equipment to the present gigantic installations. The outcome of 83 years of evolution is subsequently submitted to an anatomical analysis, which allows identifying the main components of a modern RF system and their interrelations.

  20. The evolution of scientific and technological research and law

    International Nuclear Information System (INIS)

    Frowein, J.A.

    1979-01-01

    The author considers how research findings have been included in established law. In parts law refers to the state of art or to the state of science and technology (Federal Act for Protection Against Nuisances, Atomic Energy Law). The problem is how to determine this 'state'. Furthermore, problems are discussed which result from setting limits to research work, primarily from limits set by fundamental rights (genetic engineering, experiments with human subjects). Finally, the author examines to what extent research contributes to the further development of the legal system. Apart from the creation of new legal fields (laws relating to outer space, laws relating to the protection of data), there is the issue of fundamental changes occurring in the legal system, to be seen in the introduction of the liability for dangers and the producer liability. The legal system has the task to re-define the principle of human dignity again and again, and to protect it against a variety of dangers. (orig./HSCH) [de

  1. The Co-evolution of Technologies and Markets - On Market Transparency in Nanotech Evolution

    DEFF Research Database (Denmark)

    Andersen, Maj Munch

    is an emerging technology at an infant stage of commercial development expectations to its economic and societal impacts are huge. However, despite ongoing large investments globally, the rate of commercial development is slower than expected. The reasons seem to be rising concerns about risks to health...... and the environment associated with nanotechnology. There are some early indications that firms are developing new nano strategies where nano activities increasingly are treated discretely. The paper investigates these trends using the flat glass industry as case based on bibliometric studies and other company...

  2. Flaked stones and old bones: biological and cultural evolution at the dawn of technology.

    Science.gov (United States)

    Plummer, Thomas

    2004-01-01

    The appearance of Oldowan sites ca. 2.6 million years ago (Ma) may reflect one of the most important adaptive shifts in human evolution. Stone artifact manufacture, large mammal butchery, and novel transport and discard behaviors led to the accumulation of the first recognized archaeological debris. The appearance of the Oldowan sites coincides with generally cooler, drier, and more variable climatic conditions across Africa, probably resulting in a net decrease in woodland foods and an increase in large mammal biomass compared to the early and middle Pliocene. Shifts in plant food resource availability may have provided the stimulus for incorporating new foods into the diet, including meat from scavenged carcasses butchered with stone tools. Oldowan artifact form varies with clast size, shape, raw material physical properties, and flaking intensity. Oldowan hominins preferred hard raw materials with good fracture characteristics. Habitual stone transport is evident from technological analysis, and raw material sourcing to date suggests that stone was rarely moved more than 2-3 km from source. Oldowan debris accumulation was spatially redundant, reflecting recurrent visitation of attractive points on the landscape. Thin archaeological horizons from Bed I Olduvai Gorge, Tanzania, were probably formed and buried in less than 10 years and document hominin processing of multiple carcasses per year. Transport beyond simple refuging behavior is suggested by faunal density at some site levels. By 2.0 Ma, hominin rank within the predatory guild may have been moderately high, as they probably accessed meaty carcasses through hunting and confrontational scavenging, and hominin-carnivore competition appears minimal at some sites. It is likely that both Homo habilis sensu stricto and early African H. erectus made Oldowan tools. H. habilis sensu stricto was more encephalized than Australopithecus and may foreshadow H. erectus in lower limb elongation and some thermoregulatory

  3. A paleo-aerodynamic exploration of the evolution of nature's flyers, man's aircraft, and the needs and options for future technology innovations

    Science.gov (United States)

    Kulfan, Brenda M.

    2009-03-01

    Insights and observations of fascinating aspects of birds, bugs and flying seeds, of inspired aerodynamic concepts, and visions of past, present and future aircraft developments are presented. The evolution of nature's flyers, will be compared with the corresponding evolution of commercial aircraft. We will explore similarities between nature's creations and man's inventions. Many critical areas requiring future significant technology based solutions remain. With the advent of UAVs and MAVs, the gap between "possible" and "actual" is again very large. Allometric scaling procedures will be used to explore size implications on limitations and performance capabilities of nature's creations. Biologically related technology development concepts including: bionics, biomimicry, neo-bionic, pseudo-mimicry, cybernetic and non-bionic approaches will be discussed and illustrated with numerous examples. Technology development strategies will be discussed along with the pros and cons for each. Future technology developments should include a synergistic coupling of "discovery driven", "product led" and "technology acceleration" strategies. The objective of this presentation is to inspire the creative nature existing within all of us. This is a summary all text version of the complete report with the same title that report includes approximately 80 figures, photos and charts and much more information.

  4. Introducing time delay in the evolution of new technology: the case study of nanotechnology

    Science.gov (United States)

    Georgalis, Evangelos E.; Aifantis, Elias C.

    2013-12-01

    Starting with Feynman's "There's Plenty of Room at the Bottom" prophetic lecture at Caltech in the 1960s, the term "nanotechnology" was first coined in the scientific literature in the 1980s. This was followed by the unprecedented growth in the corresponding scientific field in 2000 due to the financial incentive provided by President Clinton in the US, followed up by similar efforts in Europe, Japan, China and Russia. Today, nanotechnology has become a driving force for economic development, with applications in all fields of engineering, information technology, transport and energy, as well as biology and medicine. Thus, it is important to forecast its future growth and evolution on the basis of two different criteria: (1) the government and private capital invested in related activities, and (2) the number of scientific publications and popular articles dedicated to this field. This article aims to extract forecasts on the evolution of nanotechnology, using the standard logistic equation that result in familiar sigmoid curves, as well as to explore the effect of time delay on its evolution. Time delay is commonly known from previous biological and ecological models, in which time lag is either already known or can be experimentally measured. In contrast, in the case of a new technology, we must first define the method for determining time delay and then interpret its existence and role. Then we describe the implications that time delay may have on the stability of the sigmoidal behavior of nanotechnology evolution and on the related oscillations that may appear.

  5. Surf and turf: predation by egg-eating snakes has led to the evolution of parental care in a terrestrial lizard.

    Science.gov (United States)

    Pike, David A; Clark, Rulon W; Manica, Andrea; Tseng, Hui-Yun; Hsu, Jung-Ya; Huang, Wen-San

    2016-02-26

    Animals display a great diversity of parental care tactics that ultimately enhance offspring survival, but how such behaviors evolve remains unknown for most systems. Here, we studied the evolution of maternal care, in the form of nest guarding, in a single population of long-tailed sun skink (Eutropis longicaudata) living on Orchid Island (Taiwan). This species typically does not provide protection to its offspring. Using a common garden experiment, we show that maternal care is genetically determined in this population. Through field manipulations, we demonstrate that care provides a significant increase in egg survival on Orchid Island by reducing predation from egg-eating snakes (Oligodon formosanus); this predator is not abundant in other populations of the lizard, which do not display parental care. Finally, using extensive field surveys, we show that the seasonal availability of green sea turtle (Chelonia mydas) nests is the cause for the high abundance of snake predators on Orchid Island, with the snakes consuming lizard eggs when green turtle eggs are not available. Together, these lines of evidence provide the first full demonstration of how predation can trigger the evolution of parental care in a species derived from a non-caring ancestor.

  6. Proceedings of the electricity distribution information systems and technology conference : smart technology : evolution or revolution

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This conference provided a forum for electric utility operators, electrical engineers, and IT professionals to discuss smart technology applications for managing electrical supply and distribution. Recent advances in 3-D visualization and smart grid technologies were discussed as well as issues related to ethernet networks and grid intelligence technologies. Developments in virtualization and their potential applications in the electric power industry were evaluated. Distribution automation innovations were reviewed. Technical challenges related to the recent growth in distributed generation connections were also discussed, as well as electronic records management and cyber security strategies. Smart meters and home energy network innovations were presented. Other topics included meter data management techniques, design considerations for control centres, and the development of data stores for smart meters. The conference featured 23 presentations, of which 4 have been catalogued separately for inclusion in this database. tabs., figs.

  7. Dynamical assessment for evolutions of Atomic-Multinology (AM) in technology innovation using social network theory

    International Nuclear Information System (INIS)

    Woo, Taeho

    2012-01-01

    Highlights: ► The popularity of AM is analyzed by the social network theory. ► The graphical and colorful configurations are used for the meaning of the incident. ► The new industrial field is quantified by dynamical investigations. ► AM can be successfully used in nuclear industry for technology innovation. ► The method could be used for other industries. - Abstract: The technology evolution is investigated. The proposed Atomic Multinology (AM) is quantified by the dynamical method incorporated with Monte-Carlo method. There are three kinds of the technologies as the info-technology (IT), nano-technology (NT), and bio-technology (BT), which are applied to the nuclear technology. AM is initiated and modeled for the dynamic quantifications. The social network algorithm is used in the dynamical simulation for the management of the projects. The result shows that the successfulness of the AM increases, where the 60 years are the investigated period. The values of the dynamical simulation increase in later stage, which means that the technology is matured as time goes on.

  8. Two-wheeled motor vehicle technology in India: Evolution, prospects and issues

    International Nuclear Information System (INIS)

    Iyer, Narayan V.; Badami, Madhav G.

    2007-01-01

    By providing affordable mobility to millions of people, two-wheeled motor (M2W) vehicles play a vital role in urban transport in India and other low-income Asian countries. At the same time, these vehicles contribute significantly to urban transport impacts and energy consumption, and are characterized by high emissions and traffic mortalities per passenger-kilometre. Given the importance of technology in the popularity of these vehicles and their transport impacts, this paper discusses the evolution of M2W vehicle technology in India, and contributory factors including market forces, environmental regulation, and industry R and D efforts. It then discusses technologies that we expect to be implemented for M2W vehicles in India over the next two or three decades, the likely implications of these technologies in terms of vehicle price, emissions, fuel economy and service life, and issues related to vehicle technology development and implementation. The paper shows that while the Indian M2W vehicle industry has achieved a transformation in innovation, product development and quality in response to market demands and environmental concerns, various technological and institutional challenges need to be addressed by this and the oil and vehicle servicing industries, and government agencies at all levels, to successfully deploy advanced vehicle technologies

  9. Nobel Prize for blue LEDs

    International Nuclear Information System (INIS)

    Kraftmakher, Yaakov

    2015-01-01

    A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent light bulbs caused by the Planck distribution and properties of the human eye are illustrated. The efficiency and luminous efficacy of thermal radiation are calculated for various temperatures; the results clearly show the limitations for thermal radiators. The only way to overcome these limitations is using non-thermal radiators, such as fluorescent lamps and light-emitting diodes (LEDs). Unique advantages of LEDs undoubtedly made a revolution in this field. A crucial element of this progress is the blue LEDs (Nobel Prize 2014). Some experiments with a blue and a green LED are described: (i) the luminescence triggered in a green-yellow phosphor inside a white LED by the blue LED; (ii) radiant spectra and ‘efficiency droop’ in the LEDs; (iii) modulation of the blue LED up to 4 MHz; and (iv) the h/e ratio from the turn-on voltage of the green LED. The experiments are suitable for undergraduate laboratories and usable as classroom demonstrations. (paper)

  10. Nobel Prize for blue LEDs

    Science.gov (United States)

    Kraftmakher, Yaakov

    2015-05-01

    A brief review of lighting technologies is presented. Unavoidable restrictions for incandescent light bulbs caused by the Planck distribution and properties of the human eye are illustrated. The efficiency and luminous efficacy of thermal radiation are calculated for various temperatures; the results clearly show the limitations for thermal radiators. The only way to overcome these limitations is using non-thermal radiators, such as fluorescent lamps and light-emitting diodes (LEDs). Unique advantages of LEDs undoubtedly made a revolution in this field. A crucial element of this progress is the blue LEDs (Nobel Prize 2014). Some experiments with a blue and a green LED are described: (i) the luminescence triggered in a green-yellow phosphor inside a white LED by the blue LED; (ii) radiant spectra and ‘efficiency droop’ in the LEDs; (iii) modulation of the blue LED up to 4 MHz; and (iv) the h/e ratio from the turn-on voltage of the green LED. The experiments are suitable for undergraduate laboratories and usable as classroom demonstrations.

  11. The Evolution of Technology in the Deep Space Network: A History of the Advanced Systems Program

    Science.gov (United States)

    Layland, J. W.; Rauch, L. L.

    1994-01-01

    The Deep Space Network (DSN) of 1995 might be described as the evolutionary result of 45 years of deep space communication and navigation, together with the synergistic activities of radio science and radar and radio astronomy. But the evolution of the DSN did not just happen - it was carefully planned and created. The evolution of the DSN has been an ongoing engineering activity, and engineering is a process of problem solving under constraints, one of which is technology. In turn, technology is the knowledge base providing the capability and experience for practical application of various areas of science, when needed. The best engineering solutions result from optimization under the fewest constraints, and if technology needs are well anticipated (ready when needed), then the most effective engineering solution is possible. Throughout the history of the DSN it has been the goal and function of DSN advanced technology development (designated the DSN Advanced Systems Program from 1963 through 1994) to supply the technology needs of the DSN when needed, and thus to minimize this constraint on DSN engineering. Technology often takes considerable time to develop, and when that happens, it is important to have anticipated engineering needs; at times, this anticipation has been by as much as 15 years. Also, on a number of occasions, mission malfunctions or emergencies have resulted in unplanned needs for technology that has, in fact, been available from the reservoir of advanced technology provided by the DSN Advanced Systems Program. Sometimes, even DSN engineering personnel fail to realize that the organization of JPL permits an overlap of DSN advanced technology activities with subsequent engineering activities. This can result in the flow of advanced technology into DSN engineering in a natural and sometimes almost unnoticed way. In the following pages, we will explore some of the many contributions of the DSN Advanced Systems Program that were provided to DSN

  12. Knowledge Evolution in Distributed Geoscience Datasets and the Role of Semantic Technologies

    Science.gov (United States)

    Ma, X.

    2014-12-01

    Knowledge evolves in geoscience, and the evolution is reflected in datasets. In a context with distributed data sources, the evolution of knowledge may cause considerable challenges to data management and re-use. For example, a short news published in 2009 (Mascarelli, 2009) revealed the geoscience community's concern that the International Commission on Stratigraphy's change to the definition of Quaternary may bring heavy reworking of geologic maps. Now we are in the era of the World Wide Web, and geoscience knowledge is increasingly modeled and encoded in the form of ontologies and vocabularies by using semantic technologies. Accordingly, knowledge evolution leads to a consequence called ontology dynamics. Flouris et al. (2008) summarized 10 topics of general ontology changes/dynamics such as: ontology mapping, morphism, evolution, debugging and versioning, etc. Ontology dynamics makes impacts at several stages of a data life cycle and causes challenges, such as: the request for reworking of the extant data in a data center, semantic mismatch among data sources, differentiated understanding of a same piece of dataset between data providers and data users, as well as error propagation in cross-discipline data discovery and re-use (Ma et al., 2014). This presentation will analyze the best practices in the geoscience community so far and summarize a few recommendations to reduce the negative impacts of ontology dynamics in a data life cycle, including: communities of practice and collaboration on ontology and vocabulary building, link data records to standardized terms, and methods for (semi-)automatic reworking of datasets using semantic technologies. References: Flouris, G., Manakanatas, D., Kondylakis, H., Plexousakis, D., Antoniou, G., 2008. Ontology change: classification and survey. The Knowledge Engineering Review 23 (2), 117-152. Ma, X., Fox, P., Rozell, E., West, P., Zednik, S., 2014. Ontology dynamics in a data life cycle: Challenges and recommendations

  13. Genetic Epidemiology and Public Health: The Evolution From Theory to Technology.

    Science.gov (United States)

    Fallin, M Daniele; Duggal, Priya; Beaty, Terri H

    2016-03-01

    Genetic epidemiology represents a hybrid of epidemiologic designs and statistical models that explicitly consider both genetic and environmental risk factors for disease. It is a relatively new field in public health; the term was first coined only 35 years ago. In this short time, the field has been through a major evolution, changing from a field driven by theory, without the technology for genetic measurement or computational capacity to apply much of the designs and methods developed, to a field driven by rapidly expanding technology in genomic measurement and computational analyses while epidemiologic theory struggles to keep up. In this commentary, we describe 4 different eras of genetic epidemiology, spanning this evolution from theory to technology, what we have learned, what we have added to the broader field of public health, and what remains to be done. © The Author 2016. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. The evolution of Interior Intrusion Detection Technology at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Graham, R.H.; Workhoven, R.M.

    1987-07-01

    Interior Intrusion Detection Technology began at Sandia National Laboratories (SNL) in 1975 as part of the Fixed Facilities Physical Protection Research and Development program sponsored by the US Department of Energy in connection with their nuclear safeguards effort. This paper describes the evolution of Interior Intrusion Detection Technology at Sandia National Laboratories from the beginning of the Interior Sensor Laboratory to the present. This Laboratory was established in 1976 to evaluate commercial interior intrusion sensors and to assist in site-specific intrusion detection system designs. Examples of special test techniques and new test equipment that were developed at the Lab are presented, including the Sandia Intruder Motion Simulator (SIMS), the Sensor and Environment Monitor (SEM), and the Sandia Interior Robot (SIR). We also discuss new sensors and unique sensor combinations developed when commercial sensors were unavailable and the future application of expert systems

  15. The evolution of interior intrusion detection technology at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Graham, R.H.; Workhoven, R.M.

    1987-07-01

    Interior Intrusion Detection Technology began at Sandia National Laboratories (SNL) in 1975 as part of the Fixed Facilities Physical Protection Research and Development program sponsored by the US Department of Energy in connection with their nuclear safeguards effort. This paper describes the evolution of Interior Intrusion Detection Technology at Sandia National Laboratories from the beginning of the Interior Sensor Laboratory to the present. This Laboratory was established in 1976 to evaluate commercial interior intrusion sensors and to assist in site-specific intrusion detection system designs. Examples of special test techniques and new test equipment that were developed at the Lab are presented, including the Sandia Intruder Motion Simulator (SIMS), the Sensor and Environment Monitor (SEM), and the Sandia Interior Robot (SIR). We also discuss new sensors and unique sensor combination developed when commercial sensors were unavailable and the future application of expert systems. 5 refs

  16. The evolution of interior intrusion detection technology at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Graham, R.H.; Workhoven, R.M.

    1987-01-01

    Interior Intrusion Detection Technology began at Sandia National Laboratories (SNL) in 1975 as part of the Fixed Facilities Physical Protection Research and Development program sponsored by the U.S. Department of Energy in connection with their nuclear safeguards effort. This paper describes the evolution of Interior Intrusion Detection Technology at Sandia National Laboratories from the beginning of the Interior Sensor Laboratory to the present. This Laboratory was established in 1976 to evaluate commercial interior intrusion sensors and to assist in site-specific intrusion detection system designs. Examples of special test techniques and new test equipment that were developed at the Lab are presented, including the Sandia Intruder Motion Simulator (SIMS), the Sensor and Environment Monitor (SEM), and the Sandia Interior Robot (SIR). The authors also discuss new sensors and unique sensor combinations developed when commercial sensors were unavailable and the future application of expert systems

  17. Cows Desiring to Be Milked? Milking Robots and the Co-Evolution of Ethics and Technology on Dutch Dairy Farms

    NARCIS (Netherlands)

    Driessen, C.P.G.; Heutinck, L.F.M.

    2015-01-01

    Ethical concerns regarding agricultural practices can be found to co-evolve with technological developments. This paper aims to create an understanding of ethics that is helpful in debating technological innovation by studying such a co-evolution process in detail: the development and adoption of

  18. The Evolution of U.S. e-Learning Policy: A Content Analysis of the National Education Technology Plans

    Science.gov (United States)

    Roumell, Elizabeth Anne; Salajan, Florin Daniel

    2016-01-01

    The purpose of this study was threefold: to expand on existing reviews of 20 years of educational technology policy in the United States, to perform an empirical content analysis of the four National Education Technology Plan (NETP) documents issued by the Department of Education since 1996, and to provide a dialectic analysis of the evolution of…

  19. Implementation of a Low-Cost Automated LED Photometer for Enzymatic Reaction Detection to Teach Basic Bioelectronics Technologies in Vocational High Schools

    Science.gov (United States)

    Chen, Huai-Yi; Nieh, Hwa-Ming; Yang, Ming-Feng; Chou, Yu-Kung; Chung, Jui-Hsu; Liou, Je-Wen

    2016-01-01

    This study proposes a home-assembled, low-cost blue light-emitting diode (LED) photometer that uses simple and low-cost hardware and software, costing about US $150. This 425-nm wavelength photometer is controlled by an 89C51 microcontroller chip. Glucose concentration detection experiments involving enzyme coupling reactions were carried out to…

  20. LED-roulette : LED's vervangen balletje

    NARCIS (Netherlands)

    Goossens, P.

    2007-01-01

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

  1. Semiconductor lasers and herterojunction leds

    CERN Document Server

    Kressel, Henry

    2012-01-01

    Semiconductor Lasers and Heterojunction LEDs presents an introduction to the subject of semiconductor lasers and heterojunction LEDs. The book reviews relevant basic solid-state and electromagnetic principles; the relevant concepts in solid state physics; and the p-n junctions and heterojunctions. The text also describes stimulated emission and gain; the relevant concepts in electromagnetic field theory; and the modes in laser structures. The relation between electrical and optical properties of laser diodes; epitaxial technology; binary III-V compounds; and diode fabrication are also consider

  2. Evolution of technology in teaching: Blackboard and beyond in Medical Education.

    Science.gov (United States)

    Muttappallymyalil, Jayakumary; Mendis, Susirith; John, Lisha Jenny; Shanthakumari, Nisha; Sreedharan, Jayadevan; Shaikh, Rizwana B

    2016-10-01

    the passing of knowledge from one generation to another - has been in existence from the earliest times of human civilization. It began in 1801, with a large piece of slate hung on the wall in a school in Scotland to provide information to a large audience at one time. In the US by mid-19th century, every class room had a blackboard to teach students. The modern version of the blackboard is either green or brown board. This was introduced in late 1960s. The whiteboards came into use during the late 1980s. Projected aids have been used since 1420. The various devices used are the epidiascope, slide projector, overhead projector for transparencies and the micro projector. An instrument to project images from a horizontal surface onto a vertical screen was invented in the 1870s. By the 1960s, transparencies were in use in classrooms. The 'Hyalotype', a transparent image of a photograph using actual black and white photographs on a glass slide that could be projected was invented in 1851. By 1916, the German company Agfa started producing colored lantern slides. The first version of PowerPoint was released by Microsoft in the year 1990. Cell phones, palmtops, and handheld computers; tablets, laptops, and media players are included under mobile learning devices. With the evolution of technology, students achieved competence and interested in interactive learning. The education industry has moved from distance learning to e-learning and finally to m-learning as knowledge expanded exponentially and the demand escalated. While using teaching aids with advanced technology, we must not forget the lessons from the past, striking a balance between embracing new methods of teaching and learning while upholding the timeless principles of education. The newer educational technology can be part of a comprehensive system for lifelong education. Use of technology in education has come a long way since the earliest times of human civilization. While embarking on aids with advanced

  3. Gas Permeability Evolution Mechanism and Comprehensive Gas Drainage Technology for Thin Coal Seam Mining

    Directory of Open Access Journals (Sweden)

    Fangtian Wang

    2017-09-01

    Full Text Available A thin coal seam mined as a protective coal seam above a gas outburst coal seam plays a central role in decreasing the degree of stress placed on a protected seam, thus increasing gas permeability levels and desorption capacities to dramatically eliminate gas outburst risk for the protected seam. However, when multiple layers of coal seams are present, stress-relieved gas from adjacent coal seams can cause a gas explosion. Thus, the post-drainage of gas from fractured and de-stressed strata should be applied. Comprehensive studies of gas permeability evolution mechanisms and gas seepage rules of protected seams close to protective seams that occur during protective seam mining must be carried out. Based on the case of the LongWall (LW 23209 working face in the Hancheng coal mine, Shaanxi Province, this paper presents a seepage model developed through the FLAC3D software program (version 5.0, Itasca Consulting Group, Inc., Minneapolis, MI, USA from which gas flow characteristics can be reflected by changes in rock mass permeability. A method involving theoretical analysis and numerical simulation was used to analyze stress relief and gas permeability evolution mechanisms present during broken rock mass compaction in a goaf. This process occurs over a reasonable amount of extraction time and in appropriate locations for comprehensive gas extraction technologies. In using this comprehensive gas drainage technological tool, the safe and efficient co-extraction of thin coal seams and gas resources can be realized, thus creating a favorable environment for the safe mining of coal and gas outburst seams.

  4. Evolution of Technology for Continuous Renal Replacement Therapy: Forty Years of Improvement.

    Science.gov (United States)

    Ronco, Claudio

    2018-01-01

    Continuous arteriovenous hemofiltration (CAVH) was proposed in 1977 as an alternative treatment for acute renal failure in patients in whom peritoneal dialysis or hemodialysis was clinically or technically precluded. In the mid-1980s, this technique was extended to infants and children. CAVH presented important advantages in the areas of hemodynamic stability, control of circulating volume, and nutritional support. However, there were serious shortcomings such as the need for arterial cannulation and limited solute clearance. These problems were solved by the introduction of continuous arteriovenous hemodiafiltration and continuous arteriovenous hemodialysis, where uremic control could be achieved by increasing countercurrent dialysate flow rates to 1.5 or 2 L/h as necessary, or by venovenous techniques utilizing a double-lumen central venous catheter for vascular access. Thus, continuous venovenous hemofiltration replaced CAVH because of its improved performance and safety. From the initial adoptive technology, specific machines have been designed to permit safe and reliable performance of the therapy. These new machines have progressively undergone a series of technological steps that have resulted in the evolution of highly sophisticated equipment utilized today. A significant number of advances have taken place since the time continuous renal replacement therapy was initiated. In particular, there have been successful experiments with high-volume hemofiltration and high-permeability hemofiltration. The additional and combined use of sorbent has also been tested successfully. Progress has been made in the technology as well as the understanding of the pathophysiology of acute kidney injury. Today, new biomaterials and new devices are available and new frontiers are on the horizon. Although improvements have been made, a lot remains to be done. Critical care nephrology is expected to further evolve in the near future, especially in the area of information and

  5. Evolutions of Advanced Stamping CAE — Technology Adventures and Business Impact on Automotive Dies and Stamping

    Science.gov (United States)

    Wang, Chuantao (C. T.)

    2005-08-01

    In the past decade, sheet metal forming and die development has been transformed to a science-based and technology-driven engineering and manufacturing enterprise from a tryout-based craft. Stamping CAE, especially the sheet metal forming simulation, as one of the core components in digital die making and digital stamping, has played a key role in this historical transition. The stamping simulation technology and its industrial applications have greatly impacted automotive sheet metal product design, die developments, die construction and tryout, and production stamping. The stamping CAE community has successfully resolved the traditional formability problems such as splits and wrinkles. The evolution of the stamping CAE technology and business demands opens even greater opportunities and challenges to stamping CAE community in the areas of (1) continuously improving simulation accuracy, drastically reducing simulation time-in-system, and improving operationalability (friendliness), (2) resolving those historically difficult-to-resolve problems such as dimensional quality problems (springback and twist) and surface quality problems (distortion and skid/impact lines), (3) resolving total manufacturability problems in line die operations including blanking, draw/redraw, trim/piercing, and flanging, and (4) overcoming new problems in forming new sheet materials with new forming techniques. In this article, the author first provides an overview of the stamping CAE technology adventures and achievements, and industrial applications in the past decade. Then the author presents a summary of increasing manufacturability needs from the formability to total quality and total manufacturability of sheet metal stampings. Finally, the paper outlines the new needs and trends for continuous improvements and innovations to meet increasing challenges in line die formability and quality requirements in automotive stamping.

  6. Evolutions of Advanced Stamping CAE -- Technology Adventures and Business Impact on Automotive Dies and Stamping

    International Nuclear Information System (INIS)

    Wang Chuantao

    2005-01-01

    In the past decade, sheet metal forming and die development has been transformed to a science-based and technology-driven engineering and manufacturing enterprise from a tryout-based craft. Stamping CAE, especially the sheet metal forming simulation, as one of the core components in digital die making and digital stamping, has played a key role in this historical transition. The stamping simulation technology and its industrial applications have greatly impacted automotive sheet metal product design, die developments, die construction and tryout, and production stamping. The stamping CAE community has successfully resolved the traditional formability problems such as splits and wrinkles. The evolution of the stamping CAE technology and business demands opens even greater opportunities and challenges to stamping CAE community in the areas of (1) continuously improving simulation accuracy, drastically reducing simulation time-in-system, and improving operationalability (friendliness) (2) resolving those historically difficult-to-resolve problems such as dimensional quality problems (springback and twist) and surface quality problems (distortion and skid/impact lines) (3) resolving total manufacturability problems in line die operations including blanking, draw/redraw, trim/piercing, and flanging, and (4) overcoming new problems in forming new sheet materials with new forming techniques. In this article, the author first provides an overview of the stamping CAE technology adventures and achievements, and industrial applications in the past decade. Then the author presents a summary of increasing manufacturability needs from the formability to total quality and total manufacturability of sheet metal stampings. Finally, the paper outlines the new needs and trends for continuous improvements and innovations to meet increasing challenges in line die formability and quality requirements in automotive stamping

  7. 3 February 2011 - British Members of the Science and Technology Committee (Commons)led by A. Miller MP signing the guest book with CERN Director for Accelerators and Technology S. Myers; in the ATLAS experimental cavern at LHC Point 1 with Spokesperson F. Gianotti and Deputy D. Charlton.

    CERN Multimedia

    Maximilien Brice

    2011-01-01

    3 February 2011 - British Members of the Science and Technology Committee (Commons)led by A. Miller MP signing the guest book with CERN Director for Accelerators and Technology S. Myers; in the ATLAS experimental cavern at LHC Point 1 with Spokesperson F. Gianotti and Deputy D. Charlton.

  8. Genome-environment interactions and prospective technology assessment: evolution from pharmacogenomics to nutrigenomics and ecogenomics.

    Science.gov (United States)

    Ozdemir, Vural; Motulsky, Arno G; Kolker, Eugene; Godard, Béatrice

    2009-02-01

    The relationships between food, nutrition science, and health outcomes have been mapped over the past century. Genomic variation among individuals and populations is a new factor that enriches and challenges our understanding of these complex relationships. Hence, the confluence of nutritional science and genomics-nutrigenomics--was the focus of the OMICS: A Journal of Integrative Biology in December 2008 (Part 1). The 2009 Special Issue (Part 2) concludes the analysis of nutrigenomics research and innovations. Together, these two issues expand the scope and depth of critical scholarship in nutrigenomics, in keeping with an integrated multidisciplinary analysis across the bioscience, omics technology, social, ethical, intellectual property and policy dimensions. Historically, the field of pharmacogenetics provided the first examples of specifically identifiable gene variants predisposing to unexpected responses to drugs since the 1950s. Brewer coined the term ecogenetics in 1971 to broaden the concept of gene-environment interactions from drugs and nutrition to include environmental agents in general. In the mid-1990s, introduction of high-throughput technologies led to the terms pharmacogenomics, nutrigenomics and ecogenomics to describe, respectively, the contribution of genomic variability to differential responses to drugs, food, and environment defined in the broadest sense. The distinctions, if any, between these newer fields (e.g., nutrigenomics) and their predecessors (e.g., nutrigenetics) remain to be delineated. For nutrigenomics, its reliance on genome-wide analyses may lead to detection of new biological mechanisms governing host response to food. Recognizing "genome-environment interactions" as the conceptual thread that connects and runs through pharmacogenomics, nutrigenomics, and ecogenomics may contribute toward anticipatory governance and prospective real-time analysis of these omics fields. Such real-time analysis of omics technologies and

  9. LED Shipboard Lighting: A Comparative Analysis

    Science.gov (United States)

    2009-12-01

    viability of retrofitting the Navy fleet with newer lighting technology . C. RESEARCH QUESTION The research project provided to NPS by Dr. Larry Schuette...LED is a key component in today’s lighting technology . Modern households use LEDs in such components as digital video disc, (DVD) readers...manufactures that the Navy is serious in implementing lighting technology with a multi- year demonstration seeing the benefits provided by the manufactures

  10. Broadband Radiometric LED Measurements.

    Science.gov (United States)

    Eppeldauer, G P; Cooksey, C C; Yoon, H W; Hanssen, L M; Podobedov, V B; Vest, R E; Arp, U; Miller, C C

    2016-01-01

    At present, broadband radiometric measurements of LEDs with uniform and low-uncertainty results are not available. Currently, either complicated and expensive spectral radiometric measurements or broadband photometric LED measurements are used. The broadband photometric measurements are based on the CIE standardized V(λ) function, which cannot be used in the UV range and leads to large errors when blue or red LEDs are measured in its wings, where the realization is always poor. Reference irradiance meters with spectrally constant response and high-intensity LED irradiance sources were developed here to implement the previously suggested broadband radiometric LED measurement procedure [1, 2]. Using a detector with spectrally constant response, the broadband radiometric quantities of any LEDs or LED groups can be simply measured with low uncertainty without using any source standard. The spectral flatness of filtered-Si detectors and low-noise pyroelectric radiometers are compared. Examples are given for integrated irradiance measurement of UV and blue LED sources using the here introduced reference (standard) pyroelectric irradiance meters. For validation, the broadband measured integrated irradiance of several LED-365 sources were compared with the spectrally determined integrated irradiance derived from an FEL spectral irradiance lamp-standard. Integrated responsivity transfer from the reference irradiance meter to transfer standard and field UV irradiance meters is discussed.

  11. Implementation and Test of a LED-Based Lamp for a Lighthouse

    Directory of Open Access Journals (Sweden)

    Luca Mercatelli

    2014-01-01

    Full Text Available A novel sustainable source was developed for an existing Italian lighthouse, exploiting the light emitting diode (LED technology and the norms evolution. The research work started with the optical design of the device, while this work concerns the realization, installation, and test of the new LED lamp. The lamp recombines multiple separated LEDs, realizing a quasipunctual localized source. After installation in the lighthouse, specific photometric tests verified that the proposed power-saving source satisfied the illumination requirements of the marine signaling norms. The advantages of the LED-based lamp are reduced energy consumption, enhanced efficiency, longer life, decreased faults, slower aging, and lower maintenance costs. The obtained LED signalling device is more durable and reliable. In the future the application of these power-saving long-life sources could be extended to other maritime signaling devices or to other traffic signs.

  12. Dansk LED - Museumsbelysning

    DEFF Research Database (Denmark)

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

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

  13. Plant growth with Led lighting systems

    International Nuclear Information System (INIS)

    Campiotti, C.A.; Bernardini, A.; Di Carlo, F.; Scoccianti, M.; Alonzo, G.; Carlino, M.; Dondi, F.; Bibbiani, C.

    2009-01-01

    Leds lighting is highly relevant for the horticultural industry. Compared to other light sources used for plant production, leds have several properties which are potentially useful in relation to horticulture. However, although LEDs technology has raised strong interest in research for extraterrestrial agriculture, current LEDs panel costs are still too high for commercial adoption in greenhouse sector, and their electrical efficacies do not compete with those of high-pressure sodium lamps, but several manufactures are working to address these issues. When LEDs become practical, their ability to based light sources specifically suitable for photosynthesis and other horticulturally relevant plant properties (i.e. low radiated heat; lighting from within the canopy) will render the narrow band spectrum of LEDs of particular interest for providing light to greenhouse horticulture. A general description of LEDs application and their technical characteristics is briefly reported. [it

  14. Surface plasmon enhanced LED

    OpenAIRE

    Vučković, Jelena; Lončar, Marko; Painter, Oskar; Scherer, Axel

    2000-01-01

    Summary form only given. We designed and fabricated an LED based on a thin semiconductor membrane (λ/2) with silver mirrors. A large spontaneous emission enhancement and a high modulation speed are obtainable due to the strong localization of the electromagnetic field in the microcavity. The coupling to surface plasmon modes which are subsequently scattered out by means of a grating is used to improve the extraction efficiency of the LED. The bottom mirror is thick and unpatterned. The top mi...

  15. Evolution of gettering technologies for vacuum tubes to getters for MEMS

    Science.gov (United States)

    Amiotti, M.

    2008-05-01

    Getter materials are technically proven and industrially accepted practical ways to maintain vacuum inside hermetically sealed tubes or devices to assure high reliability and long lifetime of the operating devices. The most industrially proven vacuum tube is the cathode rays tubes (CRTs), where large surfaces are available for the deposition of an evaporated barium film by a radio frequency inductive heating of a stainless steel container filled with a BaAl4 powder mixed to Ni powder. The evolution of the CRTs manufacturing technologies required also new types of barium getters able to withstand some thermal process in air without any deterioration of the evaporation characteristics. In other vacuum tubes such as traveling waves tubes, the space available for the evaporation of a barium film and the sorption capacity required to assure the vacuum for the lifetime of the devices did not allow the use of the barium film, prompting the development of sintered non evaporable getter pills that can be activated during the manufacturing process or by flowing current through an embedded resistance. The same sintered non evaporable getter pills could find usage also in evacuated parts to thermally isolate the infrared sensors for different final applications. In high energy physics particle accelerators, the getter technology moved from localized vacuum getter pumps or getter strips to a getter coating over the surface of vacuum chambers in order to guarantee a more uniform pumping speed. With the advent of solid state electronics, new challenges faced the getter technology to assure long life to vacuum or inert gas filled hermetical packages containing microelectronic devices, especially in the telecommunication and military applications. A well known problem of GaAs devices with Pd or Pt metalization is the H2 poisoning of the metal gate: to prevent this degradation a two layer getter film has been develop to absorb a large quantity of H2 per unit of getter surface. The

  16. Evolution of gettering technologies for vacuum tubes to getters for MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Amiotti, M [SAES Getters S.p.A., Viale Italia 77, 20020 Lainate, Milano (Italy)], E-mail: Marco_Amiotti@saes-group.com

    2008-05-01

    Getter materials are technically proven and industrially accepted practical ways to maintain vacuum inside hermetically sealed tubes or devices to assure high reliability and long lifetime of the operating devices. The most industrially proven vacuum tube is the cathode rays tubes (CRTs), where large surfaces are available for the deposition of an evaporated barium film by a radio frequency inductive heating of a stainless steel container filled with a BaAl{sub 4} powder mixed to Ni powder. The evolution of the CRTs manufacturing technologies required also new types of barium getters able to withstand some thermal process in air without any deterioration of the evaporation characteristics. In other vacuum tubes such as traveling waves tubes, the space available for the evaporation of a barium film and the sorption capacity required to assure the vacuum for the lifetime of the devices did not allow the use of the barium film, prompting the development of sintered non evaporable getter pills that can be activated during the manufacturing process or by flowing current through an embedded resistance. The same sintered non evaporable getter pills could find usage also in evacuated parts to thermally isolate the infrared sensors for different final applications. In high energy physics particle accelerators, the getter technology moved from localized vacuum getter pumps or getter strips to a getter coating over the surface of vacuum chambers in order to guarantee a more uniform pumping speed. With the advent of solid state electronics, new challenges faced the getter technology to assure long life to vacuum or inert gas filled hermetical packages containing microelectronic devices, especially in the telecommunication and military applications. A well known problem of GaAs devices with Pd or Pt metalization is the H{sub 2} poisoning of the metal gate: to prevent this degradation a two layer getter film has been develop to absorb a large quantity of H{sub 2} per unit of

  17. LED Virtual Simulation based on Web3D

    OpenAIRE

    Lilan Liu; Liu Han; Zhiqi Lin; Manping Li; Tao Yu

    2014-01-01

    Regarding to the high price and low market popularity of current LED indoor lighting products, a LED indoor lighting platform is proposed based on Web3D technology. The internet virtual reality technology is integrated and applied into the LED collaborative e-commerce website with Virtools. According to the characteristics of the LED indoor lighting products, this paper introduced the method to build encapsulated model and three characteristics of LED lighting: geometrical, optical and behavi...

  18. [Evolution of technology and occupational exposures in petrochemical industry and in petroleum refining].

    Science.gov (United States)

    Cottica, Danilo; Grignani, Elena

    2013-01-01

    The industry of oil refining and petrochemical play an important role in terms of number of employees in the Italian production. Often the terms "petroleum refining" and "petrochemical" are used interchangeably to define processes that occur in complex plants, which grow outdoors on large surfaces and a visual impact is not irrelevant. In reality, the two areas involve potential exposure to different chemical agents, related to raw materials processed and the specific products. The petrochemical uses as raw materials, the oil fractions, obtained by distillation in the refinery, or natural gas; petrochemical products are, usually, single compounds with a specific degree of purity, used as basic raw materials for the entire industry of organic chemistry, from the production of plastics to pharmaceuticals. The oil refining, that is the topic of this paper, processes mainly oil to obtain mixtures of hydrocarbon compounds, the products of which are specified on the basis of aptitude for use. For example gasolines, are obtained by mixing of fractions of the first distillation, reforming products, antiknock. The paper illustrates, necessarily broadly due to the complexity of the productive sectors, the technological and organizational changes that have led to a significant reduction of occupational exposure to chemical agents, the results of environmental monitoring carried out in some refineries both during routine conditions that during scheduled maintenance activities with plant shutdown and a store of petroleum products. The chemical agents measured are typical for presence, physico-chemical properties and toxicological characteristics of the manufacturing processes of petroleum products like benzene, toluene, xylenes, ethyl benzene, n-hexane, Volatile Hydrocarbons belonging to gasoline, kerosene, diesel fuel. Data related to both personal sampling and fixed positions.

  19. Led-sukellusvalaisin

    OpenAIRE

    Saarelainen, Mikko

    2012-01-01

    Opinnäytetyön aiheena on LED ja sen käyttö sukellusvalaisimissa. Työn tarkoitus oli tutkia miten LED toimii ja miten se soveltuu käytettäväksi sukellusvalaisimessa, sekä syventää omaa tietoutta valosta, mitä se on ja miten sitä mitataan. Työssä käydään läpi LEDin ominaisuuksia ja miten se eroaa muista sukellusvalaisimissa käytetyistä lampuista. Työ on toteutettu tutustumalla LEDiin ja valoon käyttämällä erilaisia lähteitä ja päivittämällä nykyinen sukellusvalaisimeni LED-sukellusvalaisime...

  20. [LED lights in dermatology].

    Science.gov (United States)

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

    2017-04-01

    The use in dermatology of light-emitting diodes (LEDs) continues to be surrounded by controversy. This is due mainly to poor knowledge of the physicochemical phases of a wide range of devices that are difficult to compare to one another, and also to divergences between irrefutable published evidence either at the level of in vitro studies or at the cellular level, and discordant clinical results in a variety of different indications: rejuvenation, acne, wound healing, leg ulcers, and cutaneous inflammatory or autoimmune processes. Therapeutic LEDs can emit wavelengths ranging from the ultraviolet, through visible light, to the near infrared (247-1300 nm), but only certain bands have so far demonstrated any real value. We feel certain that if this article remains factual, then readers will have a different, or at least more nuanced, opinion concerning the use of such LED devices in dermatology. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. The evolution of atmospheric science goals and enhanced technology needed to satisfy remote sensing requirements

    Science.gov (United States)

    Russell, J. M., III

    2017-12-01

    The era of satellite observations of Earth's atmosphere has undergone a remarkable and dramatic evolution since temperature measurements were first made from the Nimbus 3 satellite launched in April 1969. Since those early days of discovery, amazing progress has occurred in scientific understanding of the atmosphere. The launch of Nimbus 7 in October 1978 provided an explosion of information on the composition of the stratosphere revealing for the first time the global distributions of stratospheric O3, H2O, CH4, CO, NO, NO2, HNO3 and aerosols. The SAGE series of satellites begun in 1979 and the Upper Atmosphere Research Satellite deployed from the Space Shuttle in October 1991 added new and more tenuous stratospheric gases especially in the odd chlorine family. Measurements of stratospheric ozone destroying chlorine and bromine compounds have continued with the EOS suite of satellites. Measurements from the TIMED satellite have provided a 15-year data set for study of the energetics, chemistry and dynamics of the mesosphere and lower thermosphere and vertical coupling between atmospheric regions. The AIM satellite has provided a 10-year data base of the tenuous layer of mesopause level noctilucent clouds and horizontal coupling between hemispheres. This progression of knowledge and measurement capability has evolved together as the needs developed to observe and characterize less abundant but more important atmospheric constituents and processes. This talk summarizes some of the key science results, the technology challenges that had to be overcome to enable the measurements and a view toward the future to meet new science requirements.

  2. The evolution of a company based on technological innovation. Gamesa; La internacionalizacion basada en la innovacion. El caso Gamesa

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Mielgo, N.

    2007-07-01

    This paper reviews the evolution of a company that has based its competitive strategy on technological innovation. Gamesa was established in 1976 and it has been continuously transforming its portfolio of businesses until it has become one of the main global operators in the field of wind turbine manufacturing. The firm was able to apply its technological capital in the emerging phase of the domestic wind energy industry. Once leadership in Spain was consolidated, Gamesa has developed an ambitious programme of sales and operational internationalisation, which has converted it in the number two producer of wind turbines worldwide. (Author)

  3. Design methodologies for reliability of SSL LED boards

    NARCIS (Netherlands)

    Jakovenko, J.; Formánek, J.; Perpiñà, X.; Jorda, X.; Vellvehi, M.; Werkhoven, R.J.; Husák, M.; Kunen, J.M.G.; Bancken, P.; Bolt, P.J.; Gasse, A.

    2013-01-01

    This work presents a comparison of various LED board technologies from thermal, mechanical and reliability point of view provided by an accurate 3-D modelling. LED boards are proposed as a possible technology replacement of FR4 LED boards used in 400 lumen retrofit SSL lamps. Presented design

  4. Evolution of Emergent Technologies for Producing Nonwoven Fabrics for Air Filtration

    Science.gov (United States)

    Ou, Yingjie

    2016-01-01

    Nonwovens is a fast growing industry driven by technological research and development (R&D), and one of the major application areas for nonwovens is air filtration. Research on nonwovens technologies has mainly focused on the science and technology areas, but there is very little published research on technology management issues within the…

  5. High Power UV LED Industrial Curing Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-14

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

  6. Thermal management for LED applications

    CERN Document Server

    Poppe, András

    2014-01-01

    Thermal Management for LED Applications provides state-of-the-art information on recent developments in thermal management as it relates to LEDs and LED-based systems and their applications. Coverage begins with an overview of the basics of thermal management including thermal design for LEDs, thermal characterization and testing of LEDs, and issues related to failure mechanisms and reliability and performance in harsh environments. Advances and recent developments in thermal management round out the book with discussions on advances in TIMs (thermal interface materials) for LED applications, advances in forced convection cooling of LEDs, and advances in heat sinks for LED assemblies. This book also: Presents a comprehensive overview of the basics of thermal management as it relates to LEDs and LED-based systems Discusses both design and thermal management considerations when manufacturing LEDs and LED-based systems Covers reliability and performance of LEDs in harsh environments Has a hands-on applications a...

  7. Deslumbramiento en dispositivos led

    OpenAIRE

    Ixtaina, Rubén Pablo; Presso, Matías; Ferreyra, Joaquín

    2012-01-01

    En el presente trabajo se presenta un estudio realizado en el LAL a dispositivos para señalización (semáforos, balizas, barrales lumínicos) con tecnología led. Las mediciones tradicionales de intensidad luminosa se complementaron con el análisis de la luminancia de los dispositivos, evaluada para diversas aperturas angula-res. Los resultados obtenidos marcan un notorio incre-mento en las luminancias puntuales, para valores de emisión globales comparables a los obtenidos en dispo-sitivos conve...

  8. THE EVOLUTION OF MANAGERIAL ACCOUNTING

    OpenAIRE

    Delia MANEA

    2012-01-01

    The technological and organizational changes that have occurred in recent years, led to the apparition and then to continuous changes in managerial accounting, requiring the reconsideration of the existing informational system, so that it will contain all the information that managers need in order to make economic decisions. This paper aims to present the most important events that have marked the evolution of managerial accounting from its occurrence until today, and some courses of action ...

  9. Technological integration in Brazilian public basic education: an analysis of the temporal evolution and the interdisciplinarity of the theme

    Directory of Open Access Journals (Sweden)

    Priscila Cadorin Nicolete

    2016-12-01

    Full Text Available The complexity inherent to technological integration in the context of basic education in the current reality of the students and the digital culture that permeates society today features a transformation in the dynamics of knowledge construction. It is difficult to connect students, fully involving them in this process when using traditional teaching and learning methods. This new context requires interdisciplinary research for better understanding, involving experts in the field of sciences and more technical areas such as engineering and computer science. To answer the question of how to handle the evolution of interdisciplinary theoretical and empirical studies related to the subject, it was developed a survey in order to understand the evolution, interdisciplinarity and the theoretical and empirical variables related to the integration of technologies in the Brazilian basic education. This article presents the results of the exploratory survey of systematic review procedures of literature in electronic databases, then bibliometric and descriptive analyzes. Among the obtained results, were identified as strategies for the integration of technologies in Brazilian public basic education: Remote Experimentation for Physics, Mobile Learning and Software teaching for practices in Mathematics classes. The studies are divided into six large areas of knowledge: Social Sciences, Decision Science, Computer Science, Engineering, Business and Mathematics, demonstrating the interdisciplinarity of the theme.

  10. Bringing Evolution to a Technological Generation: A Case Study with the Video Game SPORE

    Science.gov (United States)

    Poli, DorothyBelle; Berenotto, Christopher; Blankenship, Sara; Piatkowski, Bryan; Bader, Geoffrey A.; Poore, Mark

    2012-01-01

    The video game SPORE was found to hold characteristics that stimulate higher-order thinking even though it rated poorly for accurate science. Interested in evaluating whether a scientifically inaccurate video game could be used effectively, we exposed students to SPORE during an evolution course. Students that played the game reported that they…

  11. User Acceptance of Long-Term Evolution (LTE) Services: An Application of Extended Technology Acceptance Model

    Science.gov (United States)

    Park, Eunil; Kim, Ki Joon

    2013-01-01

    Purpose: The aim of this paper is to propose an integrated path model in order to explore user acceptance of long-term evolution (LTE) services by examining potential causal relationships between key psychological factors and user intention to use the services. Design/methodology/approach: Online survey data collected from 1,344 users are analysed…

  12. Advances in LEDs for automotive applications

    Science.gov (United States)

    Bhardwaj, Jy; Peddada, Rao; Spinger, Benno

    2016-03-01

    High power LEDs were introduced in automotive headlights in 2006-2007, for example as full LED headlights in the Audi R8 or low beam in Lexus. Since then, LED headlighting has become established in premium and volume automotive segments and beginning to enable new compact form factors such as distributed low beam and new functions such as adaptive driving beam. New generations of highly versatile high power LEDs are emerging to meet these application needs. In this paper, we will detail ongoing advances in LED technology that enable revolutionary styling, performance and adaptive control in automotive headlights. As the standards which govern the necessary lumens on the road are well established, increasing luminance enables not only more design freedom but also headlight cost reduction with space and weight saving through more compact optics. Adaptive headlighting is based on LED pixelation and requires high contrast, high luminance, smaller LEDs with high-packing density for pixelated Matrix Lighting sources. Matrix applications require an extremely tight tolerance on not only the X, Y placement accuracy, but also on the Z height of the LEDs given the precision optics used to image the LEDs onto the road. A new generation of chip scale packaged (CSP) LEDs based on Wafer Level Packaging (WLP) have been developed to meet these needs, offering a form factor less than 20% increase over the LED emitter surface footprint. These miniature LEDs are surface mount devices compatible with automated tools for L2 board direct attach (without the need for an interposer or L1 substrate), meeting the high position accuracy as well as the optical and thermal performance. To illustrate the versatility of the CSP LEDs, we will show the results of, firstly, a reflector-based distributed low beam using multiple individual cavities each with only 20mm height and secondly 3x4 to 3x28 Matrix arrays for adaptive full beam. Also a few key trends in rear lighting and impact on LED light

  13. Keeping up with Our Students: The Evolution of Technology and Standards in Art Education

    Science.gov (United States)

    Patton, Ryan M.; Buffington, Melanie L.

    2016-01-01

    This article addresses the standards of technology in the visual arts, arguing the standards function as de facto policy, the guidelines that shape what teachers teach. In this study, we investigate how art education standards approach technology as a teaching tool and artmaking medium, analyzing the current National Visual Arts Standards, the…

  14. Business Models for Sustainable Technologies: Exploring Business Model Evolution in the Case of Electric Vehicles

    NARCIS (Netherlands)

    Bohnsack, R.; Pinkse, J.; Kolk, A.

    2014-01-01

    Sustainable technologies challenge prevailing business practices, especially in industries that depend heavily on the use of fossil fuels. Firms are therefore in need of business models that transform the specific characteristics of sustainable technologies into new ways to create economic value and

  15. Evolution of Biotechnology and Information Technology and Its Impact on Human Security

    Directory of Open Access Journals (Sweden)

    Elena S. Zinovieva

    2015-01-01

    Full Text Available Abstract: The development of post-industrial society initiates profound economic, technological and cultural change in the way of life of all mankind. The revolutionary breakthroughs in the field of new technologies such as biotechnology and information technology are reflected in all spheres of human activity, directly affecting the human security. The article analyzes the consequences of widespread usage biotechnology and information technology in the foreign policy practice on the basis of the human security theory. The detailed description of the main directions of the use of biometric technology in the foreign policy and consular practices is provided, the challenges and threats to information security associated with biometrics are analyzed, arising from widespread biotechnology are the main challenges and threats to as well as human security threats arising at the present stage of development and application of these technologies. Human security threats associated with the use of biotechnology are placed in the broader context of global trends in scientific and technological development. The recommendations are formulated in the field of foreign policy and international cooperation, which would neutralize new threats to international and personal safety arising at the present stage of development of biotechnology. The authors conclude that in order to ensure ethical regulation of new technologies that address issues of human security, it is necessary to organize multi-stakeholder partnerships at national and international level with the participation of states, representatives of civil society, business and the research community.

  16. Rapid sequencing of the bamboo mitochondrial genome using Illumina technology and parallel episodic evolution of organelle genomes in grasses.

    Directory of Open Access Journals (Sweden)

    Peng-Fei Ma

    Full Text Available BACKGROUND: Compared to their counterparts in animals, the mitochondrial (mt genomes of angiosperms exhibit a number of unique features. However, unravelling their evolution is hindered by the few completed genomes, of which are essentially Sanger sequenced. While next-generation sequencing technologies have revolutionized chloroplast genome sequencing, they are just beginning to be applied to angiosperm mt genomes. Chloroplast genomes of grasses (Poaceae have undergone episodic evolution and the evolutionary rate was suggested to be correlated between chloroplast and mt genomes in Poaceae. It is interesting to investigate whether correlated rate change also occurred in grass mt genomes as expected under lineage effects. A time-calibrated phylogenetic tree is needed to examine rate change. METHODOLOGY/PRINCIPAL FINDINGS: We determined a largely completed mt genome from a bamboo, Ferrocalamus rimosivaginus (Poaceae, through Illumina sequencing of total DNA. With combination of de novo and reference-guided assembly, 39.5-fold coverage Illumina reads were finally assembled into scaffolds totalling 432,839 bp. The assembled genome contains nearly the same genes as the completed mt genomes in Poaceae. For examining evolutionary rate in grass mt genomes, we reconstructed a phylogenetic tree including 22 taxa based on 31 mt genes. The topology of the well-resolved tree was almost identical to that inferred from chloroplast genome with only minor difference. The inconsistency possibly derived from long branch attraction in mtDNA tree. By calculating absolute substitution rates, we found significant rate change (∼4-fold in mt genome before and after the diversification of Poaceae both in synonymous and nonsynonymous terms. Furthermore, the rate change was correlated with that of chloroplast genomes in grasses. CONCLUSIONS/SIGNIFICANCE: Our result demonstrates that it is a rapid and efficient approach to obtain angiosperm mt genome sequences using

  17. Evolution of Monolithic Technology for Wireless Communications: GaN MMIC Power Amplifiers For Microwave Radios

    Directory of Open Access Journals (Sweden)

    Vittorio Camarchia

    2014-09-01

    Full Text Available This paper presents the progress of monolithic technology for microwaveapplication, focusing on gallium nitride technology advances in the realization of integratedpower amplifiers. Three design examples, developed for microwave backhaul radios, areshown. The first design is a 7 GHz Doherty developed with a research foundry, while thesecond and the third are a 7 GHz Doherty and a 7–15 GHz dual-band combined poweramplifiers, both based on a commercial foundry process. The employed architectures, themain design steps and the pros and cons of using gallium nitride technology are highlighted.The measured performance demonstrates the potentialities of the employed technology, andthe progress in the accuracy, reliability and performance of the process.

  18. Genre, technology and embodied interaction: The evolution of digital game genres and motion gaming

    Directory of Open Access Journals (Sweden)

    Andreas Gregersen

    2011-11-01

    Full Text Available Technology has been given relatively little attention in genre theory, but this article argues that material technologies can be important components in genre development. The argument is based on a historically informed analysis of digital games, with special attention paid to home console video games and recent genre developments within this domain commonly referred to as motion gaming. The main point is that digital game genres imply structured embodied activity. A constitutive element of digital game mediation is a control interface geared to player embodiment, and I propose the concept of ‘interaction modes’ to describe the coupling of technology and player embodiment and show how this can be integrated with genre theory. The resulting framework allows for increased attention to continuity and change in game and communication genres, material and digital technologies, and the related interaction modes.

  19. Mobile Technology in the Perioperative Arena: Rapid Evolution and Future Disruption.

    Science.gov (United States)

    Rothman, Brian S; Gupta, Rajnish K; McEvoy, Matthew D

    2017-03-01

    Throughout the history of medicine, physicians have relied upon disruptive innovations and technologies to improve the quality of care delivered, patient outcomes, and patient satisfaction. The implementation of mobile technology in health care is quickly becoming the next disruptive technology. We first review the history of mobile technology over the past 3 decades, discuss the impact of hardware and software, explore the rapid expansion of applications (apps), and evaluate the adoption of mobile technology in health care. Next, we discuss how technology serves as the vehicle that can transform traditional didactic learning into one that adapts to the learning behavior of the student by using concepts such as the flipped classroom, just-in-time learning, social media, and Web 2.0/3.0. The focus in this modern education paradigm is shifting from teacher-centric to learner-centric, including providers and patients, and is being delivered as context-sensitive, or semantic, learning. Finally, we present the methods by which connected health systems via mobile devices increase information collection and analysis from patients in both clinical care and research environments. This enhanced patient and provider connection has demonstrated benefits including reducing unnecessary hospital readmissions, improved perioperative health maintenance coordination, and improved care in remote and underserved areas. A significant portion of the future of health care, and specifically perioperative medicine, revolves around mobile technology, nimble learners, patient-specific information and decision-making, and continuous connectivity between patients and health care systems. As such, an understanding of developing or evaluating mobile technology likely will be important for anesthesiologists, particularly with an ever-expanding scope of practice in perioperative medicine.

  20. CALiPER Snapshot Report: Indoor LED Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    None

    2014-04-01

    Snapshot reports use data from DOE's LED Lighting Facts product list to compare the LED performance to standard technologies, and are designed to help lighting retailers, distributors, designers, utilities, energy efficiency program sponsors, and other stakeholders understand the current state of the LED market and its trajectory.

  1. Significant growth in. LED use predicted.

    Science.gov (United States)

    Simpson, Mike

    2012-03-01

    Although LED lighting has its critics, a number of whom (see article 'LED--panacea or marketing hype', HEJ--February 2012) are concerned about what they claim are some manufacturers' 'exaggerated claims' about lighting efficiency and lamp lifetime, Philips Lighting believes that, such are the advances being made in this innovative lighting technology, that LED's overall share of the European lighting market will have risen from around 7% in 2008 to 25% by 2020 and that, a decade later, it will account for a remarkable 75% of lighting sales. In the UK, Philips' technical and design director for Lighting, Mike Simpson, told HEJ editor, Jonathan Baillie, healthcare estates and facilities managers are increasingly recognising the potential to save energy, reduce carbon emissions, and cut maintenance costs, using LED.

  2. Evolution of MHC-based technologies used for detection of antigen-responsive T cells

    DEFF Research Database (Denmark)

    Bentzen, Amalie Kai; Hadrup, Sine Reker

    2017-01-01

    detection of 1-2 different T cell specificities per cell sample, to include more than 1000 evaluable pMHC molecules using novel technologies. Here, we provide an overview of MHC multimer-based detection technologies developed over two decades, focusing primarily on MHC class I interactions.......T cell-mediated recognition of peptide-major histocompatibility complex (pMHC) class I and II molecules is crucial for the control of intracellular pathogens and cancer, as well as for stimulation and maintenance of efficient cytotoxic responses. Such interactions may also play a role...... class I molecules provided sufficient stability to T cell receptor (TCR)-pMHC interactions, allowing detection of MHC multimer-binding T cells using flow cytometry. Since this breakthrough the scientific community has aimed for expanding the capacity of MHC multimer-based detection technologies...

  3. Percussive technology in human evolution: an introduction to a comparative approach in fossil and living primates.

    Science.gov (United States)

    de la Torre, Ignacio; Hirata, Satoshi

    2015-11-19

    Percussive technology is part of the behavioural suite of several fossil and living primates. Stone Age ancestors used lithic artefacts in pounding activities, which could have been most important in the earliest stages of stone working. This has relevant evolutionary implications, as other primates such as chimpanzees and some monkeys use stone hammer-and-anvil combinations to crack hard-shelled foodstuffs. Parallels between primate percussive technologies and early archaeological sites need to be further explored in order to assess the emergence of technological behaviour in our evolutionary line, and firmly establish bridges between Primatology and Archaeology. What are the anatomical, cognitive and ecological constraints of percussive technology? How common are percussive activities in the Stone Age and among living primates? What is their functional significance? How similar are archaeological percussive tools and those made by non-human primates? This issue of Phil. Trans. addresses some of these questions by presenting case studies with a wide chronological, geographical and disciplinary coverage. The studies presented here cover studies of Brazilian capuchins, captive chimpanzees and chimpanzees in the wild, research on the use of percussive technology among modern humans and recent hunter-gatherers in Australia, the Near East and Europe, and archaeological examples of this behaviour from a million years ago to the Holocene. In summary, the breadth and depth of research compiled here should make this issue of Philosophical Transactions of the Royal Society B, a landmark step forward towards a better understanding of percussive technology, a unique behaviour shared by some modern and fossil primates. © 2015 The Author(s).

  4. White LED with High Package Extraction Efficiency

    International Nuclear Information System (INIS)

    Yi Zheng; Stough, Matthew

    2008-01-01

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

  5. Development of thermal LED Model | Kapitonov | Journal of ...

    African Journals Online (AJOL)

    One of the main tasks of modern lighting technology is to increase the reliability of LED technology. In order to solve this problem, it is necessary to ensure an effective cooling of LEDs, since the values of their parameters depend substantially on the temperature of a crystal. This dependence makes a significant effect on the ...

  6. Thermo-mechanical model optimization of HB-LED packaging

    NARCIS (Netherlands)

    Yuan, C.A.; Erinc, M.; Gielen, A.W.J.; Waal, A. van der; Driel, W. van; Zhang, K.

    2011-01-01

    Lighting is an advancing phenomenon both on the technology and on the market level due to the rapid development of the solid state lighting technology. The efforts in improving the efficacy of high brightness LED's (HB-LED) have concentrated on the packaging architecture. Packaging plays a

  7. Somatic Embryogenesis in Coffee: The Evolution of Biotechnology and the Integration of Omics Technologies Offer Great Opportunities.

    Science.gov (United States)

    Campos, Nádia A; Panis, Bart; Carpentier, Sebastien C

    2017-01-01

    One of the most important crops cultivated around the world is coffee. There are two main cultivated species, Coffea arabica and C. canephora. Both species are difficult to improve through conventional breeding, taking at least 20 years to produce a new cultivar. Biotechnological tools such as genetic transformation, micropropagation and somatic embryogenesis (SE) have been extensively studied in order to provide practical results for coffee improvement. While genetic transformation got many attention in the past and is booming with the CRISPR technology, micropropagation and SE are still the major bottle neck and urgently need more attention. The methodologies to induce SE and the further development of the embryos are genotype-dependent, what leads to an almost empirical development of specific protocols for each cultivar or clone. This is a serious limitation and excludes a general comprehensive understanding of the process as a whole. The aim of this review is to provide an overview of which achievements and molecular insights have been gained in (coffee) somatic embryogenesis and encourage researchers to invest further in the in vitro technology and combine it with the latest omics techniques (genomics, transcriptomics, proteomics, metabolomics, and phenomics). We conclude that the evolution of biotechnology and the integration of omics technologies offer great opportunities to (i) optimize the production process of SE and the subsequent conversion into rooted plantlets and (ii) to screen for possible somaclonal variation. However, currently the usage of the latest biotechnology did not pass the stage beyond proof of potential and needs to further improve.

  8. Evolution of Technology Laser Scanner. Implications for use in Nuclear Power and Radioactive Facilities

    International Nuclear Information System (INIS)

    Sarti Fernandez, F.; Bonet, J.

    2012-01-01

    The main technical factors affecting these teams their actual implementation in nuclear power plants will be analyzed: data acquisition speed, sensitivity, laser power, autonomy, contamination of equipment, radiation effect, etc. In conclusion, the real difference is displayed in the data collection in function of various technologies, embodied in field time, and costs.

  9. The Evolution of Teachers' Instructional Beliefs and Practices in High-Access-to-Technology Classrooms.

    Science.gov (United States)

    Dwyer, David C.; And Others

    Beginning in 1985, Apple Computer, Inc., and several school districts began a collaboration to examine the impact of computer saturation on instruction and learning in K-12 classrooms. The initial guiding question was simply put: What happens when teachers and students have constant access to technology? To provide "constant access,"…

  10. The Moral Logic of Perpetual Evolution: A Schoolteacher Looks at Technology in Education.

    Science.gov (United States)

    Gatto, John Taylor

    1998-01-01

    Examines technology in education as social engineering that discourages intellectual development and accustoms children to accepting without question a hidden stranger's mind-altering drills. Relates this perspective to Greek philosophers Thales and Heraclitus' differing thoughts on the purpose of education: solving the universal human dilemma of…

  11. Evolution of human factors research and studies of health information technologies: the role of patient safety

    NARCIS (Netherlands)

    Beuscart-Zéphir, M. C.; Borycki, E.; Carayon, P.; Jaspers, M. W. M.; Pelayo, S.

    2013-01-01

    The objective of this survey paper is to present and explain the impact of recent regulations and patient safety initiatives (EU, US and Canada) on Human Factors (HF)/Usability studies and research focusing on Health Information Technology (HIT). The authors have selected the most prominent of these

  12. Cyber-anthropology: a new study on human and technological co-evolution.

    Science.gov (United States)

    Libin, Alexander; Libin, Elena

    2005-01-01

    For the first time cyber-anthropology is defined as a concept and a new field of study aimed at the analysis of person's reciprocal relations with the computer-generated (CG) world evolved as a result of technological progress. In the cyber-era, simulated reality has come to the point of becoming a force that has the potential to transform the human race. Digital beings such as virtual and embodied agents, although not a part of the natural human habitat, have become necessary elements of people's surroundings and life conditions. As a theoretical construct, Cyber-anthropology is concerned with the merger of natural and artificial worlds mediated by the human imagination, as well as compatibility between people and digital life they have created. As an empirical study, Cyber-anthropology deals with the psychophysiology and psychophysics, semantic and semiotics of human engagement with computer-generated reality that is viewed as a Complex Interactive System. Personal competence as a crucial element of any cyber-system underlines the importance of psychological culture in artificial world exploration. A newly developed concept of Psychological Culture is viewed as an essential part of Cyber-anthropology while concentrating on the following core issues: (1) ethical questions, such as whether or not technological tools can be employed to solve human problems; (2) moral consequences of bringing cutting edge technology into our every day life; (3) studies of individual differences regarding psychological competence of technology users through effective vs. ineffective, independent vs. addictive, and active vs. passive dichotomies. Psychological Culture is defined as the study of a person's competence associated with the use of modern technology and individual acceptability of technological innovations. Several crucial dilemmas arise when a human being is engaged in a simulated environment, and artificial agents inhabit a human world. The ultimate goal of Psychological

  13. Design in nature how the constructal law governs evolution in biology, physics, technology, and social organization

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    In this groundbreaking book, Adrian Bejan takes the recurring patterns in nature—trees, tributaries, air passages, neural networks, and lightning bolts—and reveals how a single principle of physics, the constructal law, accounts for the evolution of these and many other designs in our world. Everything—from biological life to inanimate systems—generates shape and structure and evolves in a sequence of ever-improving designs in order to facilitate flow. River basins, cardiovascular systems, and bolts of lightning are very efficient flow systems to move a current—of water, blood, or electricity. Likewise, the more complex architecture of animals evolve to cover greater distance per unit of useful energy, or increase their flow across the land. Such designs also appear in human organizations, like the hierarchical “flowcharts” or reporting structures in corporations and political bodies. All are governed by the same principle, known as the constructal law, and configure and reconfigure themselves...

  14. Complex tasks force hand laterality and technological behaviour in naturalistically housed chimpanzees: inferences in hominin evolution.

    Science.gov (United States)

    Mosquera, M; Geribàs, N; Bargalló, A; Llorente, M; Riba, D

    2012-01-01

    Clear hand laterality patterns in humans are widely accepted. However, humans only elicit a significant hand laterality pattern when performing complementary role differentiation (CRD) tasks. Meanwhile, hand laterality in chimpanzees is weaker and controversial. Here we have reevaluated our results on hand laterality in chimpanzees housed in naturalistic environments at Fundació Mona (Spain) and Chimfunshi Wild Orphanage (Zambia). Our results show that the difference between hand laterality in humans and chimpanzees is not as great as once thought. Furthermore, we found a link between hand laterality and task complexity and also an even more interesting connection: CRD tasks elicited not only the hand laterality but also the use of tools. This paper aims to turn attention to the importance of this threefold connection in human evolution: the link between CRD tasks, hand laterality, and tool use, which has important evolutionary implications that may explain the development of complex behaviour in early hominins.

  15. Affordable underwater wireless optical communication using LEDs

    Science.gov (United States)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  16. Evolution of ESR Technology and Equipment for Long Hollow Ingots Manufacture

    Science.gov (United States)

    Medovar, Lev; Stovpchenko, Ganna; Dudka, Grigory; Kozminskiy, Alexander; Fedorovskii, Borys; Lebid, Vitalii; Gusiev, Iaroslav

    In this paper development of both ESR technology and equipment for hollow ingot manufacture review and analysis are presented. The real complications of hollow ingot manufacture and some tendentious issues which restrict process dissemination are discussed. An actual data of modern manufacture of as-cast pipes for heat and power engineering by traditional ESR with consumable electrode are given. Results of microstructure and nonmetal inclusion investigations have shown the high quality of as-cast ESR pipes. On the basis of these results the possibility to produce huge ESR hollows (up 5000 mm in dia) with final goal drastically to reduce setting ratio on forged shells and rings or even replace it by ESR hollows as-cast is grounded. Two new ESR technologies — consumable electrodes change and liquid metal usage — have passed pilot tests for heavy hollow production and shown very prospective results to be presented.

  17. Ensuring Energy Efficient 5G User Equipment by Technology Evolution and Reuse

    DEFF Research Database (Denmark)

    Lauridsen, Mads; Berardinelli, Gilberto; Sørensen, Troels Bundgaard

    2014-01-01

    the features’ pros and cons in achieving high performance in terms of data rate and/or latency while limiting their effect on the UE power consumption. Based on the discussion we give general recommendations for an energy efficient 5G design in the context of a previously proposed RAT concept.......Research on fifth generation (5G) radio access technology (RAT) is ramping up, with the goal of significantly improving user data rates and latency compared to previous radio generations. While energy efficiency (EE) of the user equipment (UE) was not a key optimization parameter for the current...... standards, it is anticipated to become a distinguishing factor for 5G. In this paper, we analyze established and emerging technological solutions for features such as waveform, frame structure, duplexing and multiple antenna transmission from an EE perspective. Our contribution is to identify and discuss...

  18. Technological, political and economic changes and their implications for the evolution of broadcasting services

    DEFF Research Database (Denmark)

    Tadayoni, Reza

    2000-01-01

    The subject of this Ph.D. thesis is changes in the market for broadcasting services as a result of technological, political, and economic drivers. Broadcasting services can be categorised as a part of the ICT-based information and knowledge intensive services that have gone through radical changes...... in the last couple of decades. Broadcasting services can be categorised as a part of the information and knowledge intensive services that has gone through radical changes in the last couple of decades. There are, however, specific characteristics like deployment of advanced technologies at both supply...... and demand sites, scarcity of transmission resources, and the historical aspects that make the development of the broadcasting service market different from other information and knowledge intensive services....

  19. Lifetime prediction of LED lighting systems considering thermal coupling between LED sources and drivers

    DEFF Research Database (Denmark)

    Alfarog, Azzarn Orner; Qu, Xiaohui; Wang, Huai

    2017-01-01

    The lifetime prediction of LED lighting system is important to guide the designers to fulfill the design specifications and to benchmark the cost-competitiveness of different lighting technologies. Currently, the lifetime of LED system is usually predicted from the source part and the driver part...... separately, and then the thermal design is also optimized independently. In practice, the LED source and driver are usually compacted in a single fixture. The heat dissipated from LED source and driver will be coupled together and affect the heat transfer performance, which may degrade the whole system...... and accelerate the failure. In this paper, a new thermal model concerning the thermal coupling is proposed with Finite Element Method (FEM) simulation for parameter acquirement. The proposed model has a better estimation of the thermal stresses of key components in the LED lamps and therefore an improved...

  20. Evolution of MHC-based technologies used for detection of antigen-responsive T cells.

    Science.gov (United States)

    Bentzen, Amalie Kai; Hadrup, Sine Reker

    2017-05-01

    T cell-mediated recognition of peptide-major histocompatibility complex (pMHC) class I and II molecules is crucial for the control of intracellular pathogens and cancer, as well as for stimulation and maintenance of efficient cytotoxic responses. Such interactions may also play a role in the development of autoimmune diseases. Novel insights into this mechanism are crucial to understanding disease development and establishing new treatment strategies. MHC multimers have been used for detection of antigen-responsive T cells since the first report by Altman et al. showed that tetramerization of pMHC class I molecules provided sufficient stability to T cell receptor (TCR)-pMHC interactions, allowing detection of MHC multimer-binding T cells using flow cytometry. Since this breakthrough the scientific community has aimed for expanding the capacity of MHC multimer-based detection technologies to facilitate large-scale epitope discovery and immune monitoring in limited biological material. Screening of T cell specificity using large libraries of pMHC molecules is suitable for analyses of T cell recognition potentially at genome-wide levels rather than analyses restricted to a selection of model antigens. Such strategies provide novel insights into the immune specificities involved in disease development and response to immunotherapy, and extend fundamental knowledge related to T cell recognition patterns and cross-recognition by TCRs. MHC multimer-based technologies have now evolved from detection of 1-2 different T cell specificities per cell sample, to include more than 1000 evaluable pMHC molecules using novel technologies. Here, we provide an overview of MHC multimer-based detection technologies developed over two decades, focusing primarily on MHC class I interactions.

  1. Social learning and technological evolution during the Clovis colonization of the New World.

    Science.gov (United States)

    Eren, Metin I; Buchanan, Briggs; O'Brien, Michael J

    2015-03-01

    A long-standing debate in Pleistocene archaeology concerns the sources of variation in the technology of colonizing hunter-gatherers. One prominent example of this debate is Clovis technology (13,350-12,500 calendar years before present), which represents the earliest widespread and currently recognizable remains of hunter-gatherers in North America. Clovis projectile points appear to have been made the same way regardless of region, but several studies have documented differences in shape that appear to be regional. Two processes have been proposed for shape variation: (1) stochastic mechanisms such as copy error (drift) and (2) Clovis groups adapting their hunting equipment to the characteristics of prey and local habitat. We used statistical analysis of Clovis-point flake-scar pattern and geometric morphometrics to examine whether drift alone could cause significant differences in the technology of Stone Age colonizing hunter-gatherers. Importantly, our analysis was intraregional to rule out a priori environmental adaptation. Our analysis confirmed that the production technique was the same across the sample, but we found significant shape differences in Clovis point populations made from distinct stone outcrops. Given that current archaeological evidence suggests stone outcrops were "hubs" of regional Clovis activity, our dichotomous, intraregional results quantitatively confirm that Clovis foragers engaged in two tiers of social learning. The lower, ancestral tier relates to point production and can be tied to conformist transmission of tool-making processes across the Clovis population. The upper, derived tier relates to point shape, which can be tied to drift that resulted from increased forager interaction at different stone-outcrop hubs and decreased forager interaction among groups using different outcrops. Given that Clovis artifacts represent the earliest widespread and currently recognizable remains of hunter-gatherers in North America, our results

  2. RadWorks Project. ISS REM - to - BIRD - to - HERA: The Evolution of a Technology

    Science.gov (United States)

    McLeod, Catherine D.

    2015-01-01

    The advancement of particle detectors based on technologies developed for use in high-energy physics applications has enabled the development of a completely new generation of compact low-power active dosimeters and area monitors for use in space radiation environments. One such device, the TimePix, is being developed at CERN, and is providing the technology basis for the most recent line of radiation detection devices being developed by the NASA AES RadWorks project. The most fundamental of these devices, an ISS-Radiation Environment Monitor (REM), is installed as a USB device on ISS where it is monitoring the radiation environment on a perpetual basis. The second generation of this TimePix technology, the BIRD (Battery-operated Independent Radiation Detector), was flown on the NASA EFT-1 flight in December 2014. Data collected by BIRD was the first data made available from the Trapped Belt region of the Earth's atmosphere in over 40 years. The 3rdgeneration of this technology, the HERA (Hybrid Electronic Radiation Assessor), is planned to be integrated into the Orion EM-1, and EM-2 vehicles where it will monitor the radiation environment. For the EM-2 flight, HERA will provide Caution and Warning notification for SPEs as well as real time dose measurements for crew members. The development of this line of radiation detectors provide much greater information and characterization of charged particles in the space radiation environment than has been collected in the past, and in the process provide greater information to inform crew members of radiation related risks, while being very power and mass efficient.

  3. The evolution of systematic shelving method of the Central Technological Library (1993-2003

    Directory of Open Access Journals (Sweden)

    Mira Lebez

    2004-01-01

    Full Text Available To accomodate the stock in open public access, after the transfer of the Central Technological Library (CTK to the new location in the TR3 building in 1994, a new systematic shelving method was developed. The development of the UDC based code and the modifications of the basic scheme for arranging monographic publications shelving and e-serials classification on the CTK homepage are described. Compared to other shelving methods, the selected one is very user frendly in flexible.

  4. Software-Defined Networks as a Stage of the Network Technology Evolution

    Directory of Open Access Journals (Sweden)

    A. A. Krasotin

    2013-01-01

    Full Text Available The authors of the article focus on the concept of a software defined network. In the beginning, the brief historical account is given concerning software defined networks as a scientific concept, its formation and technological and scientific meaning. The software defined network concept is treated in the article not as the final state-of-the-art in networking, but rather as a possible step and direction in the development of a networking paradigm. The article touches on pros and cons as well of the software defined networking and gives an account of possible stages of development of this technology in the context of other technologies, considering its hybrid with MPLS, as an example. OpenFlow protocol constitutes the main part of the article. The authors further discuss various kinds of existing libraries realizing programmable management routines for a software defined network using OpenFlow. All of these libraries provide API for building modular applications for software defined network management. Touching on practical side of implementation the results of comparative tests of throughput and latency, achieved with these libraries are shown.

  5. Evolution and acceptability of medical applications of RFID implants among early users of technology.

    Science.gov (United States)

    Smith, Alan D

    2007-01-01

    RFID as a wireless identification technology that may be combined with microchip implants have tremendous potential in today's market. Although these implants have their advantages and disadvantages, recent improvements how allowed for implants designed for humans. Focus was given to the use of RFID tags and its effects on technology and CRM through a case study on VeriChip, the only corporation to hold the rights and the patent to the implantable chip for humans, and an empirically based study on working professionals to measure perceptions by early adopters of such technology. Through hypotheses-testing procedures, it was found that although some resistance to accept microchip implants was found in several applications, especially among gender, it was totally expected that healthcare and medical record keeping activities would be universally treated in a positive light and the use of authorities (namely governmental agencies) would be equally treated in a negative light by both sexes. Future trends and recommendations are presented along with statistical results collected through personal interviews.

  6. NASA Ames UV-LED Poster Overview

    Science.gov (United States)

    Jaroux, Belgacem Amar

    2015-01-01

    UV-LED is a small satellite technology demonstration payload being flown on the Saudisat-4 spacecraft that is demonstrating non-contacting charge control of an isolated or floating mass using new solid-state ultra-violet light emitting diodes (UV-LEDs). Integrated to the rest of the spacecraft and launched on a Dnepr in June 19, 2014, the project is a collaboration between the NASA Ames Research Center (ARC), Stanford University, and King Abdulaziz City for Science and Technology (KACST). Beginning with its commissioning in December, 2015, the data collected by UV-LED have validated a novel method of charge control that will improve the performance of drag-free spacecraft allowing for concurrent science collection during charge management operations as well as reduce the mass, power and volume required while increasing lifetime and reliability of a charge management subsystem. UV-LED continues to operate, exploring new concepts in non-contacting charge control and collecting data crucial to understanding the lifetime of ultra-violet light emitting diodes in space. These improvements are crucial to the success of ground breaking missions such as LISA and BBO, and demonstrates the ability of low cost small satellite missions to provide technological advances that far exceed mission costs.

  7. Improvement of isopropanol tolerance of Escherichia coli using adaptive laboratory evolution and omics technologies.

    Science.gov (United States)

    Horinouchi, Takaaki; Sakai, Aki; Kotani, Hazuki; Tanabe, Kumi; Furusawa, Chikara

    2017-08-10

    Isopropanol (IPA) is the secondary alcohol that can be dehydrated to yield propylene. To produce IPA using microorganisms, a significant issue is that the toxicity of IPA causes retardation or inhibition of cell growth, decreasing the yield. One possible strategy to overcome this problem is to improve IPA tolerance of production organisms. For the understanding of tolerance to IPA, we performed parallel adaptive laboratory evolution (ALE) of Escherichia coli under IPA stress. To identify the genotypic change during ALE, we performed genome re-sequencing analyses of obtained tolerant strains. To verify which mutations were contributed to IPA tolerance, we constructed the mutant strains and quantify the IPA tolerance of the constructed mutants. From these analyses, we found that five mutations (relA, marC, proQ, yfgO, and rraA) provided the increase of IPA tolerance. To understand the phenotypic change during ALE, we performed transcriptome analysis of tolerant strains. From transcriptome analysis, we found that expression levels of genes related to biosynthetic pathways of amino acids, iron ion homeostasis, and energy metabolisms were changed in the tolerant strains. Results from these experiments provide fundamental bases for designing IPA tolerant strains for industrial purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Hawai'i's EVolution: Hawai'i Powered. Technology Driven. (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-05-01

    This Hawaii Clean Energy Initiative (HCEI) brochure outlines Hawaii's energy and transportation goals and the implementation of electric vehicles (EV) and electric vehicle infrastructure since HCEI began in 2008. It includes information about Hawaii's role in leading the nation in available EV charging infrastructure per capita; challenges for continuing to implement EV technology; features on various successful EV users, including the Hawaiian Electric Company, Enterprise Rent-A-Car, and Senator Mike Gabbard; how EVs can integrate into and help propel Hawaii's evolving smart grid; and much more.

  9. Evolution of membrane oxygenator technology for utilization during pediatric cardiopulmonary bypass

    Directory of Open Access Journals (Sweden)

    Melchior RW

    2016-06-01

    Full Text Available Richard W Melchior,1 Steven W Sutton,2 William Harris,3 Heidi J Dalton4,5 1Department of Perfusion Services, The Children's Hospital of Philadelphia, Philadelphia, PA, 2Cardiovascular Support Services, Inc., Dallas, TX, 3Department of Perfusion Services, Ochsner Clinic Foundation, New Orleans, LA, 4Alaskan Native Tribal Health Consortium, Anchorage, AK, 5Department of Child Health, University of Arizona-College of Medicine, Phoenix, AZ, USAAbstract: The development of the membrane oxygenator for pediatric cardiopulmonary bypass has been an incorporation of ideology and technological advancements with contributions by many investigators throughout the past two centuries. With the pursuit of this technological achievement, the ability to care for mankind in the areas of cardiac surgery has been made possible. Heart disease can affect anyone within the general population, but one such segment that it can affect from inception includes children. Currently, congenital heart defects are the most common birth defects nationally and worldwide. A large meta-analysis study from 1930 to 2010 was conducted in review of published medical literature totaling 114 papers with a study population of 24,091,867 live births, and divulged a staggering incidence of congenital heart disease involving 164,396 subjects with diverse cardiac illnesses. The prevalence of these diseases increased from 0.6 per 1,000 live births from 1930–1934 to 9.1 per 1,000 live births after 1995. These data reveal an emphasis on a growing public health issue regarding congenital heart disease. This discovery displays a need for heightened awareness in the scientific and medical industrial community to accelerate investigative research on emerging cardiovascular devices in an effort to confront congenital anomalies. One such device that has evolved over the past several decades is the pediatric membrane oxygenator. The pediatric membrane oxygenator, in conjunction with the heart lung

  10. Technology, the evolution of the transnational corporation, and the nation-state: A speculative essay

    Science.gov (United States)

    Miller, A. S.

    1972-01-01

    This study deals with two exceedingly complex matters; first, the causal connection between technology and the rise of giant transnational or multinational corporations, and second, the impact that development is having on the political order called the nation-state. It is concluded that the multinational enterprise and the nation-state are the major participants in the planetary order; that the enterprise has a political role and the state has an economic role; and that they are conjoined ever increasingly into a system of global corporativism.

  11. Artificial intelligence and exponential technologies business models evolution and new investment opportunities

    CERN Document Server

    Corea, Francesco

    2017-01-01

    Artificial Intelligence is a huge breakthrough technology that is changing our world. It requires some degrees of technical skills to be developed and understood, so in this book we are going to first of all define AI and categorize it with a non-technical language. We will explain how we reached this phase and what historically happened to artificial intelligence in the last century. Recent advancements in machine learning, neuroscience, and artificial intelligence technology will be addressed, and new business models introduced for and by artificial intelligence research will be analyzed. Finally, we will describe the investment landscape, through the quite comprehensive study of almost 14,000 AI companies and we will discuss important features and characteristics of both AI investors as well as investments. This is the “Internet of Thinks” era. AI is revolutionizing the world we live in. It is augmenting the human experiences, and it targets to amplify human intelligence in a future not so distant from...

  12. The modern trends of the evolution laser information technology in oncology

    Science.gov (United States)

    Mikov, A. A.; Svirin, V. N.

    2008-04-01

    Laser-optical information technologies and devices develop since the 70- years at the end of 20 century and are broadly used for diagnostics and treatment of oncological diseases to date. Although such methods as photodynamic therapy (PDT), laser-induce thermotherapy (LITT), fluorescent diagnostics and spectrophotometry already more than 30 years are used for treatment and diagnostics of oncological diseases, nevertheless, they are enough new methods and, as a rule, are used in large scientific centers and medical institutions. This is bound, first of all, with lack of information on modern method of cancer treatment, the absence of widely available laser procedures and corresponding devices in the polyclinics and even in district hospitals, as well as insufficient understanding of application areas, where laser methods has an advantage by comparison, for instance, with beam or chemotherapy. At present day laser methods are fast upcoming direction of the treatment oncological diseases. This is explained by progress in development essentially laser, particularly diode, improvement electronic and computing components and broad introduction software-algorithmic methods of control the undertaking therapeutic and diagnostic procedures. In article are considered new laser methods of the undertaking diagnostic and therapeutic procedures and is shown that introduction multiwave laser radiation for probe and influences on tissue, the different methods of the determination of the functional state of tissues, realization of the on-line diagnostics when carrying out the therapeutic procedures, automatic control systems of the power laser radiation, which depends on state patient tissue, as well as software-algorithmic methods of management session therapeutic and diagnostic procedures greatly raises efficiency of the treatment oncological diseases. On an example of the multipurpose laser therapeutic devices("MLTA") developed and introduced in clinical practice and multipurpose

  13. Evolution of National University Students' Optical-Science-Technology competition in China

    Science.gov (United States)

    Liu, Xu; Liu, XiangDong; Wang, XiaoPing; Zheng, XiaoDong; Lin, YuanFang; Wang, Kaiwei

    2017-08-01

    The goal of National University Students' Optical-Science-Technology Competition (NUSOSTC) is to provide a nation-wide platform for students from the colleges and universities, which have majors in the field of optics and photonics, to communicate and learning each other. Meanwhile, it works on pushing forward the popularity of optoelectronic knowledge, cultivating the students' teamwork and innovation ability, promoting higher education personnel training mode and practice teaching reform, and then improving the quality of talent training. The founding, organizational structure development and overall organizational arrangements of NUSOSTC were introduced in this paper. Besides, the competition logo, theme, title, final date, numbers of participating universities, undertaking universities and cities of the five NUSOSTCs held during 2008 to 2016 and the progress had been made were given in detail.

  14. From the water wheel to turbines and hydroelectricity. Technological evolution and revolutions

    Science.gov (United States)

    Viollet, Pierre-Louis

    2017-08-01

    Since its appearance in the first century BC, the water wheel has developed with increasing pre-industrial activities, and has been at the origin of the industrial revolution for metallurgy, textile mills, and paper mills. Since the nineteenth century, the water wheel has become highly efficient. The reaction turbine appeared by 1825, and continued to undergo technological development. The impulsion turbine appeared for high chutes, by 1880. Other turbines for low-head chutes were further designed. Turbine development was associated, after 1890, with the use of hydropower to generate electricity, both for industrial activities, and for the benefits of cities. A model ;one city + one plant; was followed in the twentieth century by more complex and efficient schemes when electrical interconnection developed, together with pumped plants for energy storage.

  15. LED driver for stroboscopic interferometry

    Science.gov (United States)

    Paulin, T.; Heikkinen, V.; Kassamakov, I.; Hæggström, E.

    2012-04-01

    Three different types of white light emitting diodes (LEDs) and three types of single color LEDs were tested as light sources for stroboscopic scanning white light interferometry (SSWLI) for dynamic (MEMS) characterization. Short, intense, light pulses and low duty cycle (DC-10 MHz), and can drive single LEDs at 5A peak current (0.7% duty cycle at 1 MHz). The shortest measured electrical pulses were 6.2 +/- 0.1 ns FDHM. The minimum measured Full Duration at Half Maximum (FDHM) of the optical pulse was 8.4 +/- 0.1 ns using nonphosphor white LED and 32.1 +/- 0.1 ns using white phosphor-converted LED (0.7 % duty cycle at 1 MHz in both cases). The minimum optical pulse FDHM for a single color blue/green LED was 6.4 +/- 0.1 ns. The maximum intensity of these pulses was 630 +/- 40 μW and 540 +/- 30 μW, respectively. All types of white LEDs could be used for stroboscopic SWLI measurements at frequencies up to 2 MHz. For higher frequencies, non-phosphor white LEDs must be used together with a cyan LED to avoid ringing in the SWLI interferogram.

  16. Technological evolution of main critical processes used in COMPERJ; Evolucao tecnologica dos principais processos criticos utilizados no COMPERJ

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Roberta A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Construtora Norberto Odebrecht, Rio de Janeiro, RJ (Brazil); Seidl, Peter; Guimaraes, Maria Jose O.C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2008-07-01

    Considered key to the country, the Petrochemical Complex in Rio de Janeiro (COMPERJ) will provide significant benefits to the Brazilian industry, such as production, a large-scale petrochemical raw materials, due to bigger and better processing of heavy oil national, especially the field of Marlim. The deployment of this complex aggregate value to the national economy, due to replace the export of heavy oil, lower market value, the export of products of higher added value to be produced in the complex. The integration refining-petrochemistry that occur in COMPERJ facilitate critical processes, such as atmospheric distillation, vacuum distillation, Petrochemical FCC and polymerization processes. This venture will take in the same plant, a Basic Petrochemical Unit (UPB) and a number of Petrochemical Associates units (UPA's), where in the first generation, the UPB will produce ethylene and propylene and in the second generation, the UPA's will convert the basic petrochemical in resins such as polypropylene, polyethylene, styrene, among others. The technology of PETROBRAS in relation to processes cited previously, has made many progress in recent years and the result of this development can be seen by increasing of patent number in the technical area. The analysis of technological evolution of these processes is of extreme importance for the identification of innovation trends of Brazil in relation to other countries to confirm the great potential of the Research Center of PETROBRAS with regard to these processes. Thus, this work aims to make an analysis of the technological developments of the main critical processes that will occur in COMPERJ and their integration refining-petrochemistry, identifying the various innovations regarding these processes. (author)

  17. 5th October 2011 - Vienna Science and Technology Fund Board of Directors ((WWTF) led by Its President, Lord Mayor and Governor of Vienna M. Häupl, signing the guest book with Head of International relations F. Pauss and Director for Administration and General Infrastructure S. Lettow.

    CERN Multimedia

    2011-01-01

    5th October 2011 - Vienna Science and Technology Fund Board of Directors ((WWTF) led by Its President, Lord Mayor and Governor of Vienna M. Häupl, signing the guest book with Head of International relations F. Pauss and Director for Administration and General Infrastructure S. Lettow.

  18. Advances in NSAID development: evolution of diclofenac products using pharmaceutical technology.

    Science.gov (United States)

    Altman, Roy; Bosch, Bill; Brune, Kay; Patrignani, Paola; Young, Clarence

    2015-05-01

    Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class with anti-inflammatory, analgesic, and antipyretic properties. Contrary to the action of many traditional NSAIDs, diclofenac inhibits cyclooxygenase (COX)-2 enzyme with greater potency than it does COX-1. Similar to other NSAIDs, diclofenac is associated with serious dose-dependent gastrointestinal, cardiovascular, and renal adverse effects. Since its introduction in 1973, a number of different diclofenac-containing drug products have been developed with the goal of improving efficacy, tolerability, and patient convenience. Delayed- and extended-release forms of diclofenac sodium were initially developed with the goal of improving the safety profile of diclofenac and providing convenient, once-daily dosing for the treatment of patients with chronic pain. New drug products consisting of diclofenac potassium salt were associated with faster absorption and rapid onset of pain relief. These include diclofenac potassium immediate-release tablets, diclofenac potassium liquid-filled soft gel capsules, and diclofenac potassium powder for oral solution. The advent of topical formulations of diclofenac enabled local treatment of pain and inflammation while minimizing systemic absorption of diclofenac. SoluMatrix diclofenac, consisting of submicron particles of diclofenac free acid and a proprietary combination of excipients, was developed to provide analgesic efficacy at reduced doses associated with lower systemic absorption. This review illustrates how pharmaceutical technology has been used to modify the pharmacokinetic properties of diclofenac, leading to the creation of novel drug products with improved clinical utility.

  19. The Evolution of External Beam Radiation Therapy (EBRT) from a Technological Perspective.

    Science.gov (United States)

    Detorie, Nicholas

    2008-03-01

    Since the discovery of x-rays by Roentgen in 1895 ionizing radiations have been used as a treatment for cancer. Such treatments have been based on either implantation of radioactive materials at the site of disease or by aiming external radiation beams at the diseased site. This later method is referred to as teletherapy because the beams originate from a location outside of the body distant from the disease site itself. A brief review of the basic radiation biology will be given to illustrate the rationale for therapeutic use of ionizing radiations and the effects of beam energy and beam type- particulate or photon. The remainder of the presentation will focus on the technological teletherapy developments supported by the required physical properties of the beams and their associated characteristics that make them suitable for patient treatments. Chronological highlights will include the following sources or devices: superficial x-rays, orthovaltage x-rays, megavoltage x-rays and Cobalt 60 photons, electron beams, neutron beams, negative pi mesons, protons, and heavy ions. The presentation will illustrate how the physical beam properties have been incorporated into modern radiation treatment devices, many of which are equipped with radiation imaging capability. Such devices include: linacs equipped with multileaf collimators for beam shaping and intensity modulation, the Gamma Knife for precise and accurate irradiation of brain tumors or arterial-venous malformations (AVM), the robotic arm based Cyber Knife, and the Helical Tomotherapy unit.

  20. Old scissors to industrial automation: the impact of technologic evolution on worker's health.

    Science.gov (United States)

    Teodoroski, Rita de Cassia Clark; Koppe, Vanessa Mazzocchi; Merino, Eugênio Andrés Díaz

    2012-01-01

    To cut a fabric, the professional performs different jobs and among them stands out the cut. The scissors has been the instrument most used for this activity. Over the years, technology has been conquering its space in the textile industry. However, despite the industrial automation able to offer subsidies to answer employment market demands, without appropriate orientation, the worker is exposed to the risks inherent at the job. Ergonomics is a science that search to promote the comfort and well being in consonance with efficacy. Its goals are properly well defined and clearly guide the actions aimed at transforming the working conditions. This study aimed to analyze the activity of cut tissues with a machine by a seamstress and the implications on their body posture. The methodology used was the observation technique and application of the Protocol RULA, where the result obtained was the level 3 and score 5, confirming that "investigations and changes are required soon". Conclude that using the machine to tissue cut should be encouraged, but in conjunction with orientations for improving posture while handling it. It seeks to prevent dysfunction of the musculoskeletal system that prevents employees from performing their work tasks efficiently and productively.

  1. Confronting prospective teachers' ideas of evolution and scientific inquiry using technology and inquiry-based tasks

    Science.gov (United States)

    Crawford, Barbara A.; Zembal-Saul, Carla; Munford, Danusa; Friedrichsen, Patricia

    2005-08-01

    This study addresses the need for research in three areas: (1) teachers' understandings of scientific inquiry; (2) conceptual understandings of evolutionary processes; and (3) technology-enhanced instruction using an inquiry approach. The purpose of this study was to determine in what ways The Galapagos Finches software-based materials created a context for learning and teaching about the nature of scientific knowledge and evolutionary concepts. The research used a design experiment in which researchers significantly modified a secondary science methods course. The multiple data sources included: audiotaped conversations of two focus pairs of participants as they interacted with the software; written pre- and posttests on concepts of natural selection of the 21 prospective teachers; written pre- and posttests on views of the nature of science; three e-mail journal questions; and videotaped class discussions. Findings indicate that prospective teachers initially demonstrated alternative understandings of evolutionary concepts; there were uninformed understandings of the nature of scientific inquiry; there was little correlation between understandings and disciplines; and even the prospective teachers with research experience failed to understand the diverse methods used by scientists. Following the module there was evidence of enhanced understandings through metacognition, and the potential for interactive software to provide promising context for enhancing content understandings.

  2. New dental applications with LEDs

    DEFF Research Database (Denmark)

    Argyraki, A.; Ou, Yiyu; Petersen, Paul Michael

    Visible and ultraviolet LEDs will in the future give rise to new dental applications. Fluorescence imaging, photodynamic therapy and photoactivated disinfection are important future candidates for diagnostics and treatment in dentistry.......Visible and ultraviolet LEDs will in the future give rise to new dental applications. Fluorescence imaging, photodynamic therapy and photoactivated disinfection are important future candidates for diagnostics and treatment in dentistry....

  3. Silicone materials for LED packaging

    Science.gov (United States)

    Bahadur, Maneesh; Norris, Ann W.; Zarisfi, Afrooz; Alger, James S.; Windiate, Christopher C.

    2006-08-01

    Silicone based materials have attracted considerable attention from light emitting diode (LED) manufacturers for use as encapsulants and lenses for many high brightness LED (HB LED) devices. Currently silicones function in two key roles in HB LED devices, (1) as protective lenses and (2) stress relieving encapsulants for wire bond protection. The key attributes of silicones that make them attractive as light path materials for high brightness HB LEDs include their high transparency in the UV-visible region, controlled refractive index (RI), stable thermo-mechanical properties, and tuneable modulus from soft gels to hard resins. This paper will describe recent developments in moldable silicone hard resin materials. Progress on cavity moldable and liquid injection moldable (LIM) silicone compositions for discreet components is described. Also, an example of liquid injection overmolding is presented.

  4. The evolution and cultural transmission of percussive technology: integrating evidence from palaeoanthropology and primatology.

    Science.gov (United States)

    Whiten, Andrew; Schick, Kathy; Toth, Nicholas

    2009-10-01

    We bring together the quite different kinds of evidence available from palaeoanthropology and primatology to better understand the origins of Plio-Pleistocene percussive technology. Accumulated palaeoanthropological discoveries now document the Oldowan Complex as the dominant stone tool making culture between 2.6-1.4 Ma, the earlier part of this contemporaneous with pre-Homo hominins. The principal types of artefacts and other remains from 20 Early Stone Age (Oldowan and earliest Acheulean) localities in Africa and elsewhere are reviewed and described. To better understand the ancestral behavioural foundations of this early lithic culture, we examine a range of recent findings from primatology. In particular, we attempt to identify key shared characteristics of Homo and Pan that support inferences about the preparedness of our common ancestor for the innovation of stone tool culture. Findings of particular relevance include: (i) the discovery of an expanding repertoire of percussive and other tool use based on directed use of force among wild chimpanzees, implicating capacities that include significant innovatory potential and appreciation of relevant causal factors; (ii) evidence of material cultural diversity among wild chimpanzees, indicating a readiness to acquire and transmit tool use innovations; and (iii) experimental studies of social learning in chimpanzees and bonobos that now encompass the acquisition of nut cracking through observation of skilled use of hammers and anvils by conspecifics, the diffusion within and between groups of alternative styles of tool use, and the adoption of free-hand stone-to-stone percussion to create useful flakes for cutting to gain access to food resources. We use the distributions of the inferred cultural traits in the wild to assess how diffusion relates to geographic distances, and find that shared traits drop by 50% from the approximately eight characteristic of close neighbours over a distance of approximately 700 km

  5. Experiencing LED: Lighting: New Form and Experiential Qualities Emerging in Lighting Systems using LED

    DEFF Research Database (Denmark)

    Petersen, Kjell Yngve; Kristensen, Ole; Søndergaard, Karin

    2012-01-01

    The project investigates what new forms and qualities of light emerge from technologies such as LED, with a particular focus on basic form qualities and parameters. Existing linear functional understandings of the relation between light source, light flow, reflection and visibility is challenged ...... by relational understandings, where the materiality and visibility of the light emerge through mutual influences between several adaptive and transformative elements....

  6. LED street lighting evaluation -- phase II : LED specification and life-cycle cost analysis.

    Science.gov (United States)

    2015-01-01

    Phase II of this study focused on developing a draft specification for LED luminaires to be used by IDOT : and a life-cycle cost analysis (LCCA) tool for solid state lighting technologies. The team also researched the : latest developments related to...

  7. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    OpenAIRE

    Francisco Alcántara Muñoz; Rafael Moreno-Rojas; Alicia Moreno Ortega; José Emilio Muñoz Cañete; Rafael Gómez Díaz

    2016-01-01

    This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific...

  8. Light pipes for LED measurements

    Science.gov (United States)

    Floyd, S. R.; Thomas, E. F., Jr.

    1976-01-01

    Light pipe directly couples LED optical output to single detector. Small area detector measures total optical output of diode. Technique eliminates thermal measurement problems and channels optical output to remote detector.

  9. Practical lighting design with LEDs

    CERN Document Server

    Lenk, Ron

    2016-01-01

    The second edition of Practical Lighting Design with LEDs has been revised and updated to provide the most current information for developing light-emitting diodes products. The authors, noted authorities in the field, offer a review of the most relevant topics including optical performance, materials, thermal design, and modeling and measurement. Comprehensive in scope, the text covers all the information needed to design LEDs into end products.

  10. Transport of Light Through White-LED Phosphor Plates

    NARCIS (Netherlands)

    Meretska, Maryna; Thyrrestrup Nielsen, Henri; Lagendijk, Aart; Tukker, Teus; Mosk, Allard; IJzerman, Wilbert; Vos, Willem L.; Di Bartolo, Baldassare; Collins, John; Silvestri, Luciano

    2017-01-01

    Energy efficient generation of white light has become an important societal issue in recent years. The technology of white-light emitting diodes (LEDs) is one of the main directions (Akasaki I, Amano H, Nakamura S, Blue LEDs – filling the world with new light, http://www.nobelprize.org/, 2014;

  11. Transport of light through white-LED phosphor plates

    NARCIS (Netherlands)

    Meretska, Maryna; Thyrrestrup, H.; Lagendijk, Ad; Tukker, T. W.; Mosk, A. P.; IJzerman, W. L.; Vos, Willem L.

    2017-01-01

    Energy efficient generation of white light has become an important societal issue in recent years. The technology of white-light emitting diodes (LEDs) is one of the main directions (Akasaki I, Amano H, Nakamura S, Blue LEDs – filling the world with new light, http://www.nobelprize.org/, 2014;

  12. LED roadway lighting, volume 2 : field evaluations and software comparisons.

    Science.gov (United States)

    2012-10-01

    The use of light-emitting diodes (LEDs) for roadway lighting can potentially save energy costs and reduce the frequency of maintenance. The objective of this study is to explore the current state of the art in LED roadway lighting technology. Three s...

  13. Low-Cost Illumination-Grade LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Epler, John [Philips Lumileds Lighting Company LLC, San Jose, CA (United States)

    2013-08-31

    Solid State Lighting is a cost-effective, energy-conserving technology serving a rapidly expand- ing multi-billion dollar market. This program was designed to accelerate this lighting revolution by reducing the manufacturing cost of Illumination-Grade LEDs. The technical strategy was to investigate growth substrate alternatives to standard planar sapphire, select the most effective and compatible option, and demonstrate a significant increase in Lumen/$ with a marketable LED. The most obvious alternate substrate, silicon, was extensively studied in the first two years of the program. The superior thermal and mechanical properties of Si were expected to improve wavelength uniformity and hence color yield in the manufacture of high-power illumination- grade LEDs. However, improvements in efficiency and epitaxy uniformity on standard c-plane sapphire diminished the advantages of switching to Si. Furthermore, the cost of sapphire decreased significantly and the cost of processing Si devices using our thin film process was higher than expected. We concluded that GaN on Si was a viable technology but not a practical option for Philips Lumileds. Therefore in 2012 and 2013, we sought and received amendments which broadened the scope to include other substrates and extended the time of execution. Proprietary engineered substrates, off-axis (non-c-plane) sapphire, and c-plane patterned sapphire substrates (PSS) were all investigated in the final 18 months of this program. Excellent epitaxy quality was achieved on all three candidates; however we eliminated engineered substrates and non-c-plane sapphire because of their higher combined cost of substrate, device fabrication and packaging. Ultimately, by fabricating a flip-chip (FC) LED based upon c-plane PSS we attained a 42% reduction in LED manufacturing cost relative to our LUXEON Rebel product (Q1-2012). Combined with a flux gain from 85 to 102 Lm, the LUXEON Q delivered a 210% increase in Lm/$ over this time period. The

  14. LED light engine concept with ultra-high scalable luminance

    Science.gov (United States)

    Hoelen, Christoph; de Boer, Dick; Bruls, Dominique; van der Eyden, Joost; Koole, Rolf; Li, Yun; Mirsadeghi, Mo; Vanbroekhoven, Vincent; Van den Bergh, John-John; Van de Voorde, Patrick

    2016-03-01

    Although LEDs have been introduced successfully in many general lighting applications during the past decade, high brightness light source applications are still suffering from the limited luminance of LEDs. High power LEDs are generally limited in luminance to ca 100 Mnit (108 lm/m2sr) or less, while dedicated devices for projection may achieve luminance values up to ca 300 Mnit with phosphor converted green. In particular for high luminous flux applications with limited étendue, like in front projection systems, only very modest luminous flux values in the beam can be achieved with LEDs compared to systems based on discharge lamps. In this paper we introduce a light engine concept based on a light converter rod pumped with blue LEDs that breaks through the étendue and brightness limits of LEDs, enabling LED light source luminance values that are more than 4 times higher than what can be achieved with LEDs so far. In LED front projection systems, green LEDs are the main limiting factor. With our green light emitting modules, peak luminance values well above 1.2 Gnit have been achieved, enabling doubling of the screen brightness of LED based DLP projection systems, and even more when this technology is applied to other colors as well. This light source concept, introduced as the ColorSpark High Lumen Density (HLD) LED technology, enables a breakthrough in the performance of LED-based light engines not only for projection, where >2700 ANSI lm was demonstrated, but for a wide variety of high brightness applications.

  15. Energy perspectives of France by 2020-2050. Technological evolutions; Perspectives energetiques de la France a l'horizon 2020-2050. Evolutions technologiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-09-15

    The different technologies in phase of research and development and concerning the energy production or storage, are examined and presented in function of their probability of emergence at the industrial level: the projects which are going to appear in planed time on the market, the projects based on known technologies which should appear but at non predicted date and the possible projects but based on a new technology. The different type of energy, from the fossil fuels to the renewable energies are concerned. (A.L.B.)

  16. Extracting light out of LEDs

    Science.gov (United States)

    Muschaweck, Julius; Wiesmann, Christopher

    2013-08-01

    `External quantum efficiency', that is, the number of photons generated per electron passing through the p-n junction of an LED is probably the most important number to quantify the performance of an LED chip. Although advances in epitaxy have increased the fraction of radiative recombination to extremely high values, the extraction of the precious photons that are trapped in a high refractive index crystal is still tricky. In this brief tutorial, we look at the physics of light extraction both from a geometrical optics/thermodynamic and a wave optics point of view, discussing both random and deterministic surface structures.

  17. Wheat Under LED's (Light Emitting Diodes)

    Science.gov (United States)

    2004-01-01

    Astroculture is a suite of technologies used to produce and maintain a closed controlled environment for plant growth. The two most recent missions supported growth of potato, dwarf wheat, and mustard plants, and provided scientists with the first opportunity to conduct true plant research in space. Light emitting diodes have particular usefulness for plant growth lighting because they emit a much smaller amount of radiant heat than do conventional lighting sources and because they have potential of directing a higher percentage of the emitted light onto plants surfaces. Furthermore, the high output LED's have emissions in the 600-700 nm waveband, which is of highest efficiency for photosynthesis by plants.

  18. White LED motorcycle headlamp design

    Science.gov (United States)

    Sun, Wen-Shing

    2015-09-01

    The motorcycle headlamp is composed of a white LED module, an elliptical reflector, a parabolic reflector and a toric lens. We use non-sequential ray to improve the optical efficiency of the compound reflectors. Using the toric lens can meet ECE_113 regulation and obtain a good uniformity.

  19. UV-LED photopolymerised monoliths

    Czech Academy of Sciences Publication Activity Database

    Abele, S.; Nie, F.; Foret, František; Paull, B.; Macka, M.

    2008-01-01

    Roč. 133, č. 7 (2008), s. 864-866 ISSN 0003-2654 R&D Projects: GA AV ČR KAN400310651 Institutional research plan: CEZ:AV0Z40310501 Keywords : photopolymerisation * UV-LED * polymethacrylate monolith Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.761, year: 2008

  20. Architecture-Led Safety Process

    Science.gov (United States)

    2016-12-01

    Contents Acknowledgments iv Abstract v 1 Introduction 1 2 Architecture -Led Processes and ALSA 2 3 ALSA Practices 5 3.1 Example System 8 4 Identify... Architecture Models 13 5 Identify Operational Hazards and Hazard Contributors 15 5.1 System Partitioning 15 5.2 Operational Context as a Control

  1. LED lamp power management system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A. M.

    2013-03-19

    An LED lamp power management system and method including an LED lamp having an LED controller 58; a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 reduces power loss in one of the channel switch 62 and the shunt switch 68 when LED lamp electronics power loss (P.sub.loss) exceeds an LED lamp electronics power loss limit (P.sub.lim); and each of the channel switches 62 receives a channel switch control signal 63 from the LED controller 58 and each of the shunt switches 68 receives a shunt switch control signal 69 from the LED controller 58.

  2. LED lamp color control system and method

    Science.gov (United States)

    Gaines, James; Clauberg, Bernd; Van Erp, Josephus A.M.

    2013-02-05

    An LED lamp color control system and method including an LED lamp having an LED controller 58; and a plurality of LED channels 60 operably connected to the LED controller 58, each of the plurality of LED channels 60 having a channel switch 62 in series with at least one shunted LED circuit 83, the shunted LED circuit 83 having a shunt switch 68 in parallel with an LED source 80. The LED controller 58 determines whether the LED source 80 is in a feedback controllable range, stores measured optical flux for the LED source 80 when the LED source 80 is in the feedback controllable range, and bypasses storing the measured optical flux when the LED source 80 is not in the feedback controllable range.

  3. Celebrity-led development organisations

    DEFF Research Database (Denmark)

    Budabin, Alexandra Cosima; Rasmussen, Louise Mubanda; Richey, Lisa Ann

    2017-01-01

    The past decade has seen a frontier open up in international development engagement with the entrance of new actors such as celebrity-led organisations. We explore how such organisations earn legitimacy with a focus on Madonna’s Raising Malawi and Ben Affleck’s Eastern Congo Initiative. The study...... draws from organisational materials, interviews, mainstream news coverage, and the texts of the celebrities themselves to investigate the construction of authenticity, credibility, and accountability. We find these organisations earn legitimacy and flourish rapidly amid supportive elite networks...... for funding, endorsements, and expertise. We argue that the ways in which celebrity-led organisations establish themselves as legitimate development actors illustrate broader dynamics of the machinery of development....

  4. Luminescent ceramics for LED conversion

    Science.gov (United States)

    Raukas, M.; Wei, G.; Bergenek, K.; Kelso, J.; Zink, N.; Zheng, Y.; Hannah, M.; Stough, M.; Wirth, R.; Linkov, A.; Jermann, F.; Eisert, D.

    2011-03-01

    Many LED-based applications would benefit from more efficient and/or high lumen output devices that enable usage in both white and single color illumination schemes. In the present article we briefly review the materials research history leading to optical ceramic converters and discuss their typical characteristics. Recently demonstrated high performance values in terms of efficacy and external quantum efficiency in orange (amber) spectral region are described.

  5. Automotive LED lamp lighted appearance

    Science.gov (United States)

    Conn, Lawrence G.; Bennett, Larry R.

    2001-05-01

    The automotive optical engineer has an entirely new set of rules to follow for a 'smooth lighted appearance' with the introduction of LEDs into the automotive signal lighting market. To move away from the 'polka-dot' appearance long associated with the usage of LEDs as the light source for automotive lighting, and give the consumer a smooth lighted appearance to his lamp, there are several optical parameters that must be observed. The number and type of LEDs used, the size of the optical elements used, the spacing of the optical elements, plus many other factors all play a critical role and must be considered in the solution to the 'smooth lighted appearance' in an automotive signal lamp. The 'smooth lighted appearance' in an automotive signal lamp has long been a difficult problem to which there is more than one solution. The most visually pleasing and effective solution is not always the most easily obtainable solution since photometry requirements and smooth lighted appearance can be diametric goals. Subsequently the most cost effective and the easily 'doable' solution may not give the ultimate in aesthetically pleasing results for the consumer. Therefore, it is the purpose and intent of this paper to outline the parameters that need to be considered to obtain a 'smooth lighted appearance' for an automotive signal lamp, and to clarify the methods and 'tools' that are required to meet this goal.

  6. The Victoria West: earliest prepared core technology in the Acheulean at Canteen Kopje and implications for the cognitive evolution of early hominids.

    Science.gov (United States)

    Li, Hao; Kuman, Kathleen; Lotter, Matt G; Leader, George M; Gibbon, Ryan J

    2017-06-01

    Prepared core technology illustrates in-depth planning and the presence of a mental template during the core reduction process. This technology is, therefore, a significant indicator in studying the evolution of abstract thought and the cognitive abilities of hominids. Here, we report on Victoria West cores excavated from the Canteen Kopje site in central South Africa, with a preliminary age estimate of approximately 1 Ma (million years ago) for these cores. Technological analysis shows that the Victoria West cores bear similarities to the 'Volumetric Concept' as defined for the Levallois, a popular and widely distributed prepared core technology from at least 200 ka (thousand years ago). Although these similarities are present, several notable differences also occur that make the Victoria West a unique and distinctive prepared core technology; these are: elongated and convergent core shapes, consistent blow directions for flake removal, a predominance of large side-struck flakes, and the use of these flakes to make Acheulean large cutting tools. This innovative core reduction strategy at Canteen Kopje extends the roots of prepared core technology to the latter part of the Early Acheulean and clearly demonstrates an increase in the cognitive abilities and complexities of hominids in this time period.

  7. LED Street Lights in Alaska

    Science.gov (United States)

    2010-09-01

    During winter nights in Alaska, streetlights often remain lit more than half the day, using energy all the while. Around the nation, communities are exploring the use of : light-emitting diode technology for lighting streets and reducing energy use. ...

  8. Evolution of technology convergence networks in Korea: Characteristics of temporal changes in R&D according to institution type.

    Science.gov (United States)

    Choi, Jae Young; Jeong, Seongkyoon; Jung, Jung-Kyu

    2018-01-01

    This study investigates the temporal changes in development of technology convergence networks by institution type, i.e., public research institute (PRI), university and industry. Using the co-classification of technological domains of patents, we identified technology convergence of Korean patents, which were filed at Korea Intellectual Properties Office (KIPO) from 1997 to 2011. We conducted a network analysis at the technology level to search for the key technology fields and frequent instances of technology convergence. The results show that technology convergence networks have grown significantly in the recent period regardless of the institution type. While industries started to conspicuously engage in technology convergence in the late 1990s, universities or PRIs did not do so until the mid-2000s. This discrepancy in the phase of technology convergence is attributed to the temporal difference in R&D stage (e.g., basic research and commercial product development). Our findings imply that corporal and governmental R&D management decision on promising technology fields will be more effective if the decision makers carefully consider the type of R&D entity in analyzing technological landscapes.

  9. Evolution of technology convergence networks in Korea: Characteristics of temporal changes in R&D according to institution type

    Science.gov (United States)

    Choi, Jae Young; Jeong, Seongkyoon

    2018-01-01

    This study investigates the temporal changes in development of technology convergence networks by institution type, i.e., public research institute (PRI), university and industry. Using the co-classification of technological domains of patents, we identified technology convergence of Korean patents, which were filed at Korea Intellectual Properties Office (KIPO) from 1997 to 2011. We conducted a network analysis at the technology level to search for the key technology fields and frequent instances of technology convergence. The results show that technology convergence networks have grown significantly in the recent period regardless of the institution type. While industries started to conspicuously engage in technology convergence in the late 1990s, universities or PRIs did not do so until the mid-2000s. This discrepancy in the phase of technology convergence is attributed to the temporal difference in R&D stage (e.g., basic research and commercial product development). Our findings imply that corporal and governmental R&D management decision on promising technology fields will be more effective if the decision makers carefully consider the type of R&D entity in analyzing technological landscapes. PMID:29420574

  10. LED Systems Target Plant Growth

    Science.gov (United States)

    2010-01-01

    To help develop technologies for growing edible biomass (food crops) in space, Kennedy Space Center partnered with Orbital Technologies Corporation (ORBITEC), of Madison, Wisconsin, through the Small Business Innovation Research (SBIR) program. One result of this research was the High Efficiency Lighting with Integrated Adaptive Control (HELIAC) system, components of which have been incorporated into a variety of agricultural greenhouse and consumer aquarium lighting features. The new lighting systems can be adapted to a specific plant species during a specific growth stage, allowing maximum efficiency in light absorption by all available photosynthetic tissues.

  11. Practical lighting design with LEDs

    CERN Document Server

    Lenk, Ron

    2011-01-01

    "This book covers all of the information needed to design LEDs into end-products. It is a practical guide, primarily explaning how things are done by practicing engineers. Equations are used only for practical calculations, and are kept to the level of high-school algebra. There are numerous drawings and schematics showing how things such as measurements are actually made, and showing curcuits that actually work. There are practical notes and examples embedded in the text that give pointers and how-to guides on many of the book's topics. After reading each chapter of the book, readers will have the knowledge to implement practical designs. This book will be kept as a reference tool for years to come"--

  12. An investigation on LED customer’ behavior

    Directory of Open Access Journals (Sweden)

    Samaneh Sadat Khoramgah

    2013-03-01

    Full Text Available The recent advances in technology have created a challenge for customer on purchasing electronic devises since the cycle of media production such as TV, Mobile devices, etc. are getting short and people need to replace them by new products. The recent emerge of Light Emitting Diode (LED television has attracted many people and there is a concern to study the impact of important factors on customer behavior in this business. This paper presents an empirical study to study the effects of six variables including customer perception, motivation, cognitive learning, attitude, information and price on customer behavior for LED televisions produced by an Iranian firm in Tehran, Iran. The study designs a questionnaire consists of 27 questions and distributes it among some people who are potential customers of this product. We use multiple regression analysis to study the behavior of different factors on customer behavior. The results of our survey indicate that cognitive learning had the most influencing impact (0.22 on customer behavior followed by price (0.219, motivation (0.203, attitude (0.193, information (0.183 and perception (0.145.

  13. LED--panacea or marketing hype?

    Science.gov (United States)

    Baillie, Jonathan

    2012-02-01

    With energy efficiency and carbon reduction, and the importance of a relaxing, therapeutic patient environment, ever more in the spotlight, LED lighting's proponents claim the technology offers healthcare estates personnel many of the answers on both fronts. However some observers believe its benefits are being over-sold, often to the detriment of other high-performing types of more 'conventional lighting', and to a sometimes uninitiated audience too easily swayed by slick sales patter. HEJ editor Jonathan Baillie spoke to one highly experienced lighting professional, Nicholas Bukorović, a former employee of Thorn, Cooper, and Thorlux Lighting, and the principal author of the last CIBSE/Society of Light and Lighting (SLL) Guide LG2 on healthcare lighting, to seek some expert illumination.

  14. LED lighting for greenhouses. Final report; LED belysning til vaeksthuse. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    OEstergaard, J.E. (Syddansk Univ. (SDU). Erhvervsinnovation og Teknologi, Odense (Denmark))

    2011-01-15

    The project had 3 main objectives: 1) To develop a prototype of a LED-based luminaire that can replace the existing glasshouse horticultural lighting. The project have developed a working prototype and experimentally replaced the traditional HPS luminaires in a controlled growing area. The project succeeded in producing plants of comparable quality. However, the project shows that the prototype can be improved by: x) being further integrated into the existing horticultural production technology (eg climate computers and purchase of electricity) x) adapting configuration of luminaires specifically to each plant variety x) adapting different cooling technologies to match specific customer needs x) In some cases being combined with heat input to optimize the overall economy. 2) To achieve an effective electricity savings of 50-80% - equivalent to a value of approx. DKK 5 million for a medium sized nursery. The verified electricity savings was 40%. In test setups and in well defined and controllable production areas the prototypes achieved electricity savings of > 50%. It is expected that a new generation of LEDs (Q3 2010) will allow for greater power savings. 3) To continue prototype development and initiate commercialization of the project through the company Fionia Lighting A/S. The shareholders of the company have allocated capital to the company to allow us to address the main challenges in commercializing the technology. It is expected that the company will enter a strategic alliance with a major industrial player in the beginning of 2011. (Author)

  15. Technology.

    Science.gov (United States)

    Online-Offline, 1998

    1998-01-01

    Focuses on technology, on advances in such areas as aeronautics, electronics, physics, the space sciences, as well as computers and the attendant progress in medicine, robotics, and artificial intelligence. Describes educational resources for elementary and middle school students, including Web sites, CD-ROMs and software, videotapes, books,…

  16. A New Way to Introduce Microarray Technology in a Lecture/Laboratory Setting by Studying the Evolution of This Modern Technology

    Science.gov (United States)

    Rowland-Goldsmith, Melissa

    2009-01-01

    DNA microarray is an ordered grid containing known sequences of DNA, which represent many of the genes in a particular organism. Each DNA sequence is unique to a specific gene. This technology enables the researcher to screen many genes from cells or tissue grown in different conditions. We developed an undergraduate lecture and laboratory…

  17. Evolution and convergence in telecommunications

    International Nuclear Information System (INIS)

    Radicella, S.; Grilli, D.

    2002-01-01

    These lectures throw a spotlight on different aspects of the evolution of telecommunications networks, namely on the various facets of service and network convergence. The last years progress in data and telecommunications technologies, such as P-based networks, and the enormous potential of mobile communication systems and users' demands for comprehensive and network-independent have led to a convergence of data and telecommunications infrastructures in many aspects. In order to help the reader to an easier understanding of the phenomenon convergence, in the first two parts of this volume the evolution of the basic technologies is described one by one. This is done briefly and is focused on the principle topics, just to build a basis for the third part devoted to problems of convergence in telecommunications. These notes are addressed to those readers, who in a quick overview want to be informed on the future service and network landscape. The notes are equally suited for professionals with the desire to extend their horizon as well as for students looking for an introduction into telecommunications under more general aspects. The authors clearly understand the difficulties in writing a book devoted to the evolution in telecommunications. Today, telecom landscape varies at very high speed. Every few months new network technologies, new products and new services are developed. Attempts to present them in time can be accessible only for magazine publications or contributions to conferences. Therefore, in a number of areas, such as Voice over IP and new switching technologies not much more than the starting point of new paradigms is described. However, the content is up-to-date to a degree, that the phenomenon convergence can be fully understood. Partially, these notes are based on a number of lecture courses that were delivered during recent ICTP winter schools devoted to multimedia and digital communications

  18. LEDs light up the world

    Energy Technology Data Exchange (ETDEWEB)

    Mather, N.

    2004-06-30

    A lighting system using light-emitting diodes, and privately financed by a Canadian engineering professor at the University of Calgary, has been set up in a village in Nepal in 2000. Since then, through the efforts of the 'Light Up The World' Foundation, established by Dr. Irvine-Halliday, projects have lit up thousands of homes in the Philippines, India, Afghanistan, the Galapagos Islands, Mexico, Sri Lanka, and Angola. Although the goal of the project is primarily to provide lighting for reading and writing for school-children, the project has been the source of many other advantages; creation of enterprise, increased employment, enhanced income, gender equality, and improvements in health and safety among them. Since LED lamps in most cases replace kerosene lamps, the system also has significant environmental benefits. The system as originally envisioned creates electricity by pedal-powered generator, or by solar panels connected to a battery, depending on what is available at each home. Each home is connected to the power supply and supplied with low-energy diode lamps. The lights are extremely efficient and many homes can be equipped with them using less energy than it takes to power a single 100-watt light bulb. 5 photos.

  19. Conduction-driven cooling of LED-based automotive LED lighting systems for abating local hot spots

    Science.gov (United States)

    Saati, Ferina; Arik, Mehmet

    2018-02-01

    Light-emitting diode (LED)-based automotive lighting systems pose unique challenges, such as dual-side packaging (front side for LEDs and back side for driver electronics circuit), size, harsh ambient, and cooling. Packaging for automotive lighting applications combining the advanced printed circuit board (PCB) technology with a multifunctional LED-based board is investigated with a focus on the effect of thermal conduction-based cooling for hot spot abatement. A baseline study with a flame retardant 4 technology, commonly known as FR4 PCB, is first compared with a metal-core PCB technology, both experimentally and computationally. The double-sided advanced PCB that houses both electronics and LEDs is then investigated computationally and experimentally compared with the baseline FR4 PCB. Computational models are first developed with a commercial computational fluid dynamics software and are followed by an advanced PCB technology based on embedded heat pipes, which is computationally and experimentally studied. Then, attention is turned to studying different heat pipe orientations and heat pipe placements on the board. Results show that conventional FR4-based light engines experience local hot spots (ΔT>50°C) while advanced PCB technology based on heat pipes and thermal spreaders eliminates these local hot spots (ΔT<10°C), leading to a higher lumen extraction with improved reliability. Finally, possible design options are presented with embedded heat pipe structures that further improve the PCB performance.

  20. Progress in extremely high brightness LED-based light sources

    Science.gov (United States)

    Hoelen, Christoph; Antonis, Piet; de Boer, Dick; Koole, Rolf; Kadijk, Simon; Li, Yun; Vanbroekhoven, Vincent; Van De Voorde, Patrick

    2017-09-01

    Although the maximum brightness of LEDs has been increasing continuously during the past decade, their luminance is still far from what is required for multiple applications that still rely on the high brightness of discharge lamps. In particular for high brightness applications with limited étendue, e.g. front projection, only very modest luminance values in the beam can be achieved with LEDs compared to systems based on discharge lamps or lasers. With dedicated architectures, phosphor-converted green LEDs for projection may achieve luminance values up to 200-300 Mnit. In this paper we report on the progress made in the development of light engines based on an elongated luminescent concentrator pumped by blue LEDs. This concept has recently been introduced to the market as ColorSpark High Lumen Density LED technology. These sources outperform the maximum brightness of LEDs by multiple factors. In LED front projection, green LEDs are the main limiting factor. With our green modules, we now have achieved peak luminance values of 2 Gnit, enabling LED-based projection systems with over 4000 ANSI lm. Extension of this concept to yellow and red light sources is presented. The light source efficiency has been increased considerably, reaching 45-60 lm/W for green under practical application conditions. The module architecture, beam shaping, and performance characteristics are reviewed, as well as system aspects. The performance increase, spectral range extensions, beam-shaping flexibility, and cost reductions realized with the new module architecture enable a breakthrough in LED-based projection systems and in a wide variety of other high brightness applications.

  1. Designing low cost LED display for the billboard

    Science.gov (United States)

    Hong, Yi-Jian; Uang, Chii-Maw; Wang, Ping-Chieh; Ho, Zu-Sheng

    2011-10-01

    With quickly advance of the computer, microelectronics and photonics technologies, LED display panel becomes a new electronic advertising media. It can be used to show any information whatever characters or graphics. Most LED display panels are built of many Light-Emitting Diodes arranged in a matrix form. The display has many advantages such as low power, low cost, long life and high definition. Because the display panel is asked to show rich color, the LED display panel's driving system becomes very complex. The design methodology of LED display panel's driver becomes more and more important to meet the market requirements. Cost is always the most important issue in public market domain. In this paper, we report a design methodology of LED display panel's driver based on the microprocessor control unit (MCU) system and LED display controller IC, HT1632C, to control three colors, RGB, color LED display panel and the modular panel size is 24*16 in matrix form. The HT1632C is a memory mapping LED display controller, it can be used on many applications, such as digital clock, thermometer, counter, voltmeter or other instrumentation readouts. Three pieces of HT1632C are used to drive a 24*16 RGB LED display panel, in our design case. Each HT163C chip is used to control one of the R, G and B color. As the drive mode is driven in DC mode, the RGB display panel can create and totally of seven colors under the control of MCU. The MCU generates the control signal to drive HT1632C. In this study, the software design methodology is adopted with dynamic display principle. When the scan frequency is 60Hz, LED display panel will get the clear picture and be able to display seven colors.

  2. Thermo-mechanical evaluation and life time simulation of high power LED lamp boards

    NARCIS (Netherlands)

    Jakovenko, J.; Formánek, J.; Pardo, B.; Perpiñà, X.; Werkhoven, R.J.; Kunen, J.M.G.; Bancken, P.; Bolt, P.J.

    2012-01-01

    This work deals with a precise 3-D modelling of several LED board technologies mainly focused on thermal, thermo-mechanical evaluation and life time prediction to compare their performances. Main role of each LED board is to transport heat from LED die to heat sink and keep the thermal stresses in

  3. GATEWAY Demonstrations: Philadelphia International Airport Apron Lighting: LED System Performance in a Trial Installation

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-30

    This report documents a trial installation of LED apron lighting that replaced the existing high-pressure sodium luminaires at Philadelphia International Airport. Such high-mast applications remain challenging for LED technology, and the lessons learned from this project may help facility managers and LED product manufacturers better meet those challenges.

  4. Photometric characterization of LED's for optimal design of interior lamps

    International Nuclear Information System (INIS)

    Hernandez, O.; Guerra, H.; Leon, V.; Torres, A. W.; Castannon, H.; Camas, J.

    2012-01-01

    The Tuxtla Gutierrez Technology Institute, and the Innovaluz of Mexico S A of C V company have joined forces to develop LED lighting technology in Chiapas, Mexico. We performed a comprehensive study of power savings for a household using this luminary. The main results of the Lighting are presented exclusively for the ILIGPL153BF24W model, as well as the design features of a functional lamp. (Author)

  5. Dome diagnostics system of optical parameters and characteristics of LEDs

    Science.gov (United States)

    Peretyagin, Vladimir S.; Pavlenko, Nikita A.

    2017-09-01

    Scientific and technological progress of recent years in the production of the light emitting diodes (LEDs) has led to the expansion of areas of their application from the simplest systems to high precision lighting devices used in various fields of human activity. However, development and production (especially mass production) of LED lighting devices are impossible without a thorough analysis of its parameters and characteristics. There are many ways and devices for analysis the spatial, energy and colorimetric parameters of LEDs. The most methods are intended for definition only one parameter (for example, luminous flux) or one characteristic (for example, the angular distribution of energy or the spectral characteristics). Besides, devices used these methods are intended for measuring parameters in only one point or plane. This problem can be solved by using a dome diagnostics system of optical parameters and characteristics of LEDs, developed by specialists of the department OEDS chair of ITMO University in Russia. The paper presents the theoretical aspects of the analysis of LED's spatial (angular), energy and color parameters by using mentioned of diagnostics system. The article also presents the results of spatial), energy and color parameters measurements of some LEDs brands.

  6. Energy savings by implementation of light quality LED lighting. Final report; Implementering af energibesparelser ved benyttelse af hoejkvalitets LED belysning. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Hansen, C.; Thorseth, A.; Poulsen, Peter

    2010-03-15

    The project developed two new LED light sources and systems, emphasising the potential of LED technology for energy savings and lighting quality. A LED light source for display case lighting, replacing incandescent lamps, was successfully installed in the Treasury at Rosenborg Castle in Copenhagen, Denmark, and it was decided to extend the solution in 2010. Electricity savings of 74% were achieved. LED light sources replacing halogen bulbs in cooker hoods reduce electricity consumption by 69% and ensure even lighting of the entire working surface with about 500 lux at all cooking areas. Furthermore, a new LED optics system was patented. (ln)

  7. The Influence of New Technologies on the Evolution of Learning and Attitudes towards Mathematics in Secondary Students

    Science.gov (United States)

    Garcia, Maria del Mar; Romero, Isabel Maria

    2009-01-01

    The present article is part of a study carried out with Secondary School students in Mathematics class. Our research interest lies in exploring the influence of using ICT (Information and Communication Technology) on students' attitudes and on how they learn mathematics, as observed when they are solving contextualized problems. This is a…

  8. Technology

    Directory of Open Access Journals (Sweden)

    Xu Jing

    2016-01-01

    Full Text Available The traditional answer card reading method using OMR (Optical Mark Reader, most commonly, OMR special card special use, less versatile, high cost, aiming at the existing problems proposed a method based on pattern recognition of the answer card identification method. Using the method based on Line Segment Detector to detect the tilt of the image, the existence of tilt image rotation correction, and eventually achieve positioning and detection of answers to the answer sheet .Pattern recognition technology for automatic reading, high accuracy, detect faster

  9. Fokusgruppeinterview som led i en evalueringsproces

    DEFF Research Database (Denmark)

    Andersen-Mølgaard, Hanna; Harrit, Ole

    2006-01-01

    Teoretiske begrundelser og perspektiver, responsiv-konstruktivistisk evaluering, fokusgruppeinterview som led i BIKVAmodellen, eksempler, vurdering og perspektivering......Teoretiske begrundelser og perspektiver, responsiv-konstruktivistisk evaluering, fokusgruppeinterview som led i BIKVAmodellen, eksempler, vurdering og perspektivering...

  10. Evaluation of LED vehicular and pedestrian modules.

    Science.gov (United States)

    2009-04-01

    This study was conducted to verify the compliance of vehicular and pedestrian LED traffic signal modules with the Institute : of Transportation Engineers specifications; and to assess drivers preferences of the LED modules. Four vehicular modules ...

  11. Goniometric characterization of LED based greenhouse lighting

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  12. LOW-COST LED LUMINAIRE FOR GENERAL ILLUMINATION

    Energy Technology Data Exchange (ETDEWEB)

    Lowes, Ted

    2014-07-31

    During this two-year Solid-State Lighting (SSL) Manufacturing R&D project Cree developed novel light emitting diode (LED) technologies contributing to a cost-optimized, efficient LED troffer luminaire platform emitting at ~3500K correlated color temperature (CCT) at a color rendering index (CRI) of >90. To successfully achieve program goals, Cree used a comprehensive approach to address cost reduction of the various optical, thermal and electrical subsystems in the luminaire without impacting performance. These developments built on Cree’s high- brightness, low-cost LED platforms to design a novel LED component architecture that will enable low-cost troffer luminaire designs with high total system efficacy. The project scope included cost reductions to nearly all major troffer subsystems as well as assembly costs. For example, no thermal management components were included in the troffer, owing to the optimized distribution of compact low- to mid-power LEDs. It is estimated that a significant manufacturing cost savings will result relative to Cree’s conventional troffers at the start of the project. A chief project accomplishment was the successful development of a new compact, high-efficacy LED component geometry with a broad far-field intensity distribution and even color point vs. emission angle. After further optimization and testing for production, the Cree XQ series of LEDs resulted. XQ LEDs are currently utilized in Cree’s AR series troffers, and they are being considered for use in other platforms. The XQ lens geometry influenced the independent development of Cree’s XB-E and XB-G high-voltage LEDs, which also have a broad intensity distribution at high efficacy, and are finding wide implementation in Cree’s omnidirectional A-lamps.

  13. Goniometric characterization of LED based greenhouse lighting

    DEFF Research Database (Denmark)

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

    2015-01-01

    This paper describes a demonstration of goniospectroradiometry for characterizations of new light emitting diode (LED) based luminaries for enhanced photosynthesis in greenhouses. It highlights the differences between measurement of the traditional high pressure sodium (HPS) luminaries and the LED...... based luminaries. The LED based luminaries are compared to traditional HPS luminaries; in terms of energy efficiency with regard to the photosynthetic photon flux, and the LED luminaries were found to be more effective than the HPS luminaries...

  14. Development of LED light sources and lamps. Final report; Slutrapport for PSO 337-068. Udvikling af LED lyskilder og lamper

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Hansen, C.; Petersen, Paul Michael; Thestrup, B.; Scharling Holm, J.; Munkgaard Andersen, J.; Falleboe, H.; Olsen, Jesper; Flindt, C.

    2007-04-15

    This report is the final and concluding report on the research and development project 'Development of LED light sources and lamps' PSO no. 337-068 supported by Dansk Energi - Net. The project was a collaboration between Risoe National laboratory, Louis Poulsen Lighting, Dong Energy, Laboratoriet Lys & Syn and RGB Lamps. The objective of this project was to pave the way for replacement of incandescent- and halogen lighting by LED lightning through development of prototypes for new types of LED products: light sources and lamps. The report summarizes and describes the main results of the project, which are: 1) a new LED light source with an efficacy of 51 lm/W and a CRI index of 92 that can replace an incandescent bulb. 2) two LED pendants/lamps, a LED table lamp and a chair with LED lighting developed by designers and researchers. 3) LED seminar and two exhibitions of the newly developed LED products and user test by questionnaires. 4) A new startup company 'Morfoso'. 5) Developed course on light and LED technology for designers. 6) A new LED light laboratory for test and characterization of LED components and LED light sources and lamps. (au)

  15. LED belichting tijdens het voortrekken van lelie

    NARCIS (Netherlands)

    Kok, B.J.; Wildschut, J.

    2010-01-01

    De laatste jaren staat het gebruik van LED-lampen in de tuinbouw in de belangstelling. Uit vele onderzoeken is al gebleken dat LED-lampen op dit moment nog geen alternatief zijn voor de SON-T lampen. Het grote voordeel van LED-lampen is dat ze monochromatisch licht van alle mogelijke golflengtes

  16. ‘No Blue’ White LED

    DEFF Research Database (Denmark)

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

    2010-01-01

    This paper explored the feasibility of making a white LED light source by color mixing method without using the blue color. This ‘no blue’ white LED has potential applications in photolithography room illumination, medical treatment and biophotonics research. A no-blue LED was designed, and the p...

  17. PENGEMBANGAN LAMPU LED DENGAN TEKNOLOGI PHOTOVOLTAIC (LED-PV SEBAGAI ALAT BANTU PENGUMPUL IKAN PADA PERIKANAN BAGAN

    Directory of Open Access Journals (Sweden)

    Mochamad Arief Sofijanto

    2015-03-01

    mengetahui perbedaan jumlah hasil tangkapan pada bagan tancap akibat perlakuan warna lampu LED yang berbeda. Metode penelitian yang digunakan adalah deskriptif dan experimental fishing dimana rancangan penelitiannya adalah Rancangan Acak Lengkap (RAL dengan perlakuan warna lampu LED sebanyak 5 jenis warna yaitu merah (A, kuning (B, hijau (C, biru (D, dan putih (E dengan 6 kali ulangan. Secara deskriptif hasil penelitian menunjukkan lampu LED dapat digunakan untuk menggantikan lampu petromaks dan lampu LHE. Diperoleh 17 jenis ikan laut yang tertarik pada cahaya lampu LED yang digunakan. Hasil analisis statistik menunjukkan terdapat perbedaan nyata terhadap hasil tangkapan bagan dengan perlakuan warna lampu LED. Berdasarkan Uji Nyata Terkecil dinyatakan bahwa bagan yang menggunakan warna lampu LED biru mendapatkan hasil tangkapan tertinggi kemudian diikuti oleh warna kuning, hijau, putih dan merah.  The set ‘bagan’ (liftnet fishing gear is a kind of fishing gears which using atificial light as fishes gathering. This fishing gear uses an electric generator to turn on the energy saving lamp which hang on under the set ‘bagan’. The price of gasoline more expensive due to the Indonesia government’s fuel subsidy reduced and this make fishing operation costs more expensive for fishermen. This research using the LED lamps that do not use gasoline as fuel because the LED lamps can use the photovoltaic technology (solar cell system. The purposes of this study were: 1 to find out whether the LED lamps can replace the kerosene lamps and saving energy lamps, 2 to know the different in cath using different colours of LED lamps. The reserach methods are descriptive and experimental fishing which used Completely Randomized Design with LED lamps colour treatments i.e: red (A, yellow (B, green (C, blue (D, and white (E, the number of replications are 6 times. LED lamps can be used to replace the kerosene and saving energy lamps. There were 17 species of

  18. LED Street Lighting Solutions: Flagstaff, Arizona as a Case Study

    Science.gov (United States)

    Hall, Jeffrey C.

    2018-01-01

    Dark-sky protection in Flagstaff, Arizona extends back to 1958, with the first ordinance in the City banning advertising floodlights. The current ordinance, adopted in 1989, is comprehensive and has played a critical role in maintaining the quality of the night sky for astronomy, tourism, public enjoyment, and other purposes. Flagstaff, like many communities around the world, is now working on a transition from legacy bulb-based technology to LED for its outdoor lighting. The City, Lowell Observatory, the U. S. Naval Observatory, and the Flagstaff Dark Skies Coalition have been working intensively for two years to identify an LED-based street lighting solution that will preserve the City's dark skies while meeting municipal needs. We will soon be installing test fixtures for an innovative solution incorporating narrow-band amber LED and modest amounts of low-CCT white LED. In this talk, I will review the types of LEDs available for outdoor lighting and discuss the plans for Flagstaff's street lighting in the LED era, which we hope will be a model for communities worldwide.

  19. Generation of solar spectrum by using LEDs

    Science.gov (United States)

    Lu, Pengzhi; Yang, Hua; Pei, Yanrong; Li, Jing; Xue, Bin; Wang, Junxi; Li, Jinmin

    2016-09-01

    Light emitting diode (LED) has been recognized as an applicable light source for indoor and outdoor lighting, city beautifying, landscape facilities, and municipal engineering etc. Conventional LED has superior characteristics such as long life time, low power consumption, high contrast, and wide viewing angle. Recently, LED with high color-rendering index and special spectral characteristics has received more and more attention. This paper is intended to report a solar spectrum simulated by multichip LED light source. The typical solar spectrum of 5500k released by CIE was simulated as a reference. Four types of LEDs with different spectral power distributions would be used in the LED light source, which included a 430nm LED, a 480nm LED, a 500nm LED and a white LED. In order to obtain better simulation results, the white LED was achieved by a 450nm LED chip with the mixture of phosphor. The phosphor combination was prepared by mixing green phosphor, yellow phosphor and red phosphor in a certain proportion. The multichip LED light source could provide a high fidelity spectral match with the typical solar spectrum of 5500k by adjusting injection current to each device. The luminous flux, CIE chromaticity coordinate x, y, CCT, and Ra were 104.7 lm, 0.3337, 0.3681, 5460K, and 88.6, respectively. Because of high color-rendering index and highly match to the solar spectrum, the multichip LED light source is a competitive candidate for applications where special spectral is required, such as colorimetric measurements, visual inspection, gemstone identification and agriculture.

  20. Peer-Led Team Learning Helps Minority Students Succeed.

    Science.gov (United States)

    Snyder, Julia J; Sloane, Jeremy D; Dunk, Ryan D P; Wiles, Jason R

    2016-03-01

    Active learning methods have been shown to be superior to traditional lecture in terms of student achievement, and our findings on the use of Peer-Led Team Learning (PLTL) concur. Students in our introductory biology course performed significantly better if they engaged in PLTL. There was also a drastic reduction in the failure rate for underrepresented minority (URM) students with PLTL, which further resulted in closing the achievement gap between URM and non-URM students. With such compelling findings, we strongly encourage the adoption of Peer-Led Team Learning in undergraduate Science, Technology, Engineering, and Mathematics (STEM) courses.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

  2. The human genome and the human control of natural evolution.

    Science.gov (United States)

    Sakamoto, H

    2001-10-01

    Recent advances in research on the Human Genome are provoking many critical problems in the global policy regarding the future status of human beings as well as in that of the whole life system on the earth, and consequently, these advances provoke the serious bioethical and philosophical questions. Firstly, how can we comprehend that we are going to have the complete technology to manipulate the system of the human genome and other non-human genomes? Though no science and technology can be complete, we will, I believe, take possession of an almost complete gene technology in the early stage of the next Century. Gene technology will soon fall into the hands of human beings instead of rendering in the province of God. Secondly, which gene technologies will we actually realize and utilize in the early stages of the 21st Century? Most probably, we will adopt these technologies to health care to treat some apparent bodily diseases, for instance, cancer, hemophilia, ADA deficiency, and so forth, and sooner or later we will adopt gene therapy to germ lines, which, in the long run, suggests the possibility of a future "artificial evolution" instead of the "natural evolution" of the past. Thirdly, how is the new concept of "artificial evolution" justified ethically? I believe this kind of manmade evolution is the only way for human beings to survive into the future global environment. There cannot be any serious ethical objection against the idea of artificial evolution. Fourthly, what is the background philosophy for the concept of "artificial evolution"? I will discuss the nature of modern European humanism with individual dignity and fundamental human rights which has led the philosophy of modern culture and modern society, and I will conclude by suggesting that we should abolish an essential part of modern humanism and newly devise some alternative philosophy to fit the new Millennium.

  3. Multi-sensor Evolution Analysis system: how WCS/WCPS technology supports real time exploitation of geospatial data

    Science.gov (United States)

    Natali, Stefano; Mantovani, Simone; Folegani, Marco; Barboni, Damiano

    2014-05-01

    EarthServer is a European Framework Program project that aims at developing and demonstrating the usability of open standards (OGC and W3C) in the management of multi-source, any-size, multi-dimensional spatio-temporal data - in short: "Big Earth Data Analytics". In the third and last year of EarthServer project, the Climate Data Service lighthouse application has been released in its full / consolidated mode. The Multi-sensor Evolution Analysis (MEA) system, the geospatial data analysis tool empowered with OGC standard, has been adopted to handle data manipulation and visualization; Web Coverage Service (WCS) and Web Coverage Processing Service (WCPS) are used to access and process ESA, NASA and third party products. Tenth of Terabytes of full-mission, multi-sensor, multi-resolution, multi-projection and cross-domain coverages are already available to user interest groups belonging Land, Ocean and Atmosphere products. The MEA system is available at https://mea.eo.esa.int. During the live demo, typical test cases implemented by User interest Groups within EarthServer and ESA Image Information Mining projects will be showed with special emphasis on the comparison of MACC Reanalysis and ESA CCI products.

  4. Testing Finance-Led, Export-Led and Import-Led Growth Hypotheses on Four Sub-Saharan African Economies

    OpenAIRE

    Evans, Olaniyi

    2013-01-01

    This study carries out an empirical examination of the finance-led, export-led and import-led growth hypothesis for four of the largest Sub-Saharan African economies namely South Africa, Nigeria, Ghana and Kenya. Within a multivariate Vector-Auto Regressive (VAR) framework, the concept of Granger causality is employed to determine the direction of causation between exports and output, duly taking into account the stationarity properties of the time series data. With further substantiation fro...

  5. An Integrated Solid-State LED Luminaire for General Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Dowling; Fritz Morgan Ihor Lys; Mike Datta; Bernd Keller; Thomas Yuan

    2009-03-31

    A strong systems approach to designing and building practical LED-based replacement lamps is lacking. The general method of taking high-performance LEDs and marrying them to standard printed circuit boards, drivers and a heat sink has fallen short of the promise of LED lighting. In this program, a top-down assessment of requirements and a bottom-up reinvention of LED sources, electronics, optics and mechanics have resulted in the highest performance lamp possible. The team, comprised of Color Kinetics, the leaders in LED lighting and Cree, the leaders in LED devices took an approach to reinvent the package, the driver and the overall form and aesthetic of a replacement source. The challenge was to create a new benchmark in LED lighting - the resultant lamp, a PAR38 equivalent, met the light output, color, color quality and efficacy marks set out in the program as well as being dimmable, which is important for market acceptance. The approach combined the use of multiple source die, a chip-on-board approach, a very efficient driver topology, the use of both direct emission and phosphor conversion, and a unique faceted optic to avoid the losses, artifacts and hotspots of lensed approaches. The integral heat sink provided a mechanical base and airflow using a chimney-effect for use in a wide variety of locations and orientations. These research results led to a much better understanding of the system effects of component level technologies. It was clear that best-of-breed sub-system results do not necessarily result in the best end result for the complete system. In doing this work, we did not neglect the practical aspects of these systems. These were not rarified results and commercially impractical but lent themselves to eventual commercial products in the marketplace. The end result - a high performance replacement lamp - will save significant energy while providing a high-quality light source.

  6. Has Human Evolution Stopped?

    Directory of Open Access Journals (Sweden)

    Alan R. Templeton

    2010-07-01

    Full Text Available It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.

  7. International trade, technological change and evolution of work market; Commercio internazionale, cambiamento tecnologico e mercato del lavoro

    Energy Technology Data Exchange (ETDEWEB)

    Cacciotti, M.

    1999-07-01

    The report estimates the historic series of wages and employment depending on the average unit value of importation prices in the most important european countries, Italy, France and Germany for the years 1988-1996. Results shows that in the traditional sectors, with unskilled employment are negative influenced by international trade, otherwise, in the technological advanced sectors, influenced are to be considered positive. [Italian] Lo studio sottopone a stima le serie storiche dei salari e dell'occupazione in funzione del valore medio unitario dei prezzi alle importazioni per i piu' importanti paesi europei, Italia, Francia, Germania, durante il periodo 1988-1996. I risultati mostrano che per i settori tradizionali, che impiegano manodopera meno qualificata, il commercio internazionel tende ad influenzare negativamente i livelli salariali ed occupazionali, mentre per i settorui tecnologicamente piu' avanzati determina variazioni positive dei salari e dell'occupazioni.

  8. The evolution of China's National Energy RD and D Programs: The role of scientists in science and technology decision making

    International Nuclear Information System (INIS)

    Zhi, Qiang; Su, Jun; Ru, Peng; Anadon, Laura Diaz

    2013-01-01

    Since 1978, when China launched its “opening up” reform, a range of large-scale national science and technology programs have been implemented to spur economic development. Energy has received significant attention and has become a growing priority in the past years. In this paper we have analyzed the goals, management, and impact over time of China's three largest national programs: Gong Guan, 863, and 973 Programs. Using quantitative metrics to describe the input and output, by conducting semi-structured interviews with officials, scientists, and other decision makers, and by reviewing available documents as well as a case study on the coal sector we examined the changes in the decision making process, particularly in regard to the role of scientists. We found that the changes in strategic priorities set by China's high level political leaders were implemented and then transformed into outputs by using scientists as inputs or policy tools. The decreased role of scientists has been driven by two forces: (1) periodic changes in national strategy emphasizing technology commercialization; and (2) changes in the management structure involving low tolerance of risk. We suggest four ways that the government's efforts to turn China into an innovation oriented country. - Highlights: • New data was provided for the energy sector of China's three largest RD and D programs. • Transitions of goals, priorities, management, and impact over time of the programs were reviewed. • We found the role of scientists has been reduced in the decision making process. • Two forces are identified as the shaping factors

  9. Values-led Participatory Design - Mediating the Emergence of Values

    DEFF Research Database (Denmark)

    Iversen, Ole Sejer; Leong, Tuck Wah

    2012-01-01

    There is a growing interest in values-led inquiries within participatory design. One approach argues that working with values is a recursive 3-phase process that supports the emergence, development and grounding of values. In this paper we focus solely upon the emergence phase, proposing...... an approach that can support the emergence of values during the initial phase of a values-led inquiry. To illustrate this approach and to ground our discussion, we draw from a recent participatory design case where we were engaged in the design of digital technology to support the experiences of young adults...... with severe intellectual disabilities, in an art museum. By describing how we establish, negotiate and the debrief values during this initial phase of a values-led inquiry. By foregrounding both explicit and implicit mediation in the PD process we show how a theoretical understanding of mediation can...

  10. Self-aligning LED-based optical link

    Science.gov (United States)

    Shen, Thomas C.; Drost, Robert J.; Rzasa, John R.; Sadler, Brian M.; Davis, Christopher C.

    2016-09-01

    The steady advances in light-emitting diode (LED) technology have motivated the use of LEDs in optical wireless communication (OWC) applications such as indoor local area networks (LANs) and communication between mobile platforms (e.g., robots, vehicles). In contrast to traditional radio frequency (RF) wireless communication, OWC utilizes electromagnetic spectrum that is largely unregulated and unrestricted. OWC communication may be especially useful in RF-denied environments, in which RF communication may be prohibited or undesirable. However, OWC does present some challenges, including the need to maintain alignment between potentially moving nodes. We describe a novel system for link alignment that is composed of a hyperboloidal mirror, camera, and gimbal. The experimental system is able to use the mirror and camera to detect an LED beacon of a neighboring node and estimate its bearing (azimuth and elevation), point the gimbal towards the beacon, and establish an optical link.

  11. LEDs for general and horticultural lighting

    OpenAIRE

    Girón González, Emilio

    2012-01-01

    The work begins with an introductory part about Light Emitting Diode (or LEDs) and how these devices work. This report also shows an overview of different artificial light sources such as incandescent lamps, fluorescents tube and high-intensity discharge (HID) lamps. The LED lighting is more energy-efficient than other artificial lighting, since they require less energy to operate. The following part of the work reports LEDs for General Lighting that describes some basic concepts such as spec...

  12. System Reliability for LED-Based Products

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J Lynn; Mills, Karmann; Lamvik, Michael; Yaga, Robert; Shepherd, Sarah D; Bittle, James; Baldasaro, Nick; Solano, Eric; Bobashev, Georgiy; Johnson, Cortina; Evans, Amy

    2014-04-07

    Results from accelerated life tests (ALT) on mass-produced commercially available 6” downlights are reported along with results from commercial LEDs. The luminaires capture many of the design features found in modern luminaires. In general, a systems perspective is required to understand the reliability of these devices since LED failure is rare. In contrast, components such as drivers, lenses, and reflector are more likely to impact luminaire reliability than LEDs.

  13. High-Voltage LED Light Engine with Integrated Driver

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-29

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

  14. Solid State Lighting LED Manufacturing Roundtable Summary

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2010-03-31

    Summary of a meeting of LED experts to develop proposed priority tasks for the Manufacturing R&D initiative, including task descriptions, discussion points, recommendations, and presentation highlights.

  15. Significance, evolution and recent advances in adsorption technology, materials and processes for desalination, water softening and salt removal.

    Science.gov (United States)

    Alaei Shahmirzadi, Mohammad Amin; Hosseini, Seyed Saeid; Luo, Jianquan; Ortiz, Inmaculada

    2018-06-01

    Desalination and softening of sea, brackish, and ground water are becoming increasingly important solutions to overcome water shortage challenges. Various technologies have been developed for salt removal from water resources including multi-stage flash, multi-effect distillation, ion exchange, reverse osmosis, nanofiltration, electrodialysis, as well as adsorption. Recently, removal of solutes by adsorption onto selective adsorbents has shown promising perspectives. Different types of adsorbents such as zeolites, carbon nanotubes (CNTs), activated carbons, graphenes, magnetic adsorbents, and low-cost adsorbents (natural materials, industrial by-products and wastes, bio-sorbents, and biopolymer) have been synthesized and examined for salt removal from aqueous solutions. It is obvious from literature that the existing adsorbents have good potentials for desalination and water softening. Besides, nano-adsorbents have desirable surface area and adsorption capacity, though are not found at economically viable prices and still have challenges in recovery and reuse. On the other hand, natural and modified adsorbents seem to be efficient alternatives for this application compared to other types of adsorbents due to their availability and low cost. Some novel adsorbents are also emerging. Generally, there are a few issues such as low selectivity and adsorption capacity, process efficiency, complexity in preparation or synthesis, and problems associated to recovery and reuse that require considerable improvements in research and process development. Moreover, large-scale applications of sorbents and their practical utility need to be evaluated for possible commercialization and scale up. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Efficient and versatile light. LEDs save energy and open up manifold possibilities of design; Effizientes und vielseitiges Licht. LEDs sparen Energie und eroeffnen zahlreiche Designmoeglichkeiten

    Energy Technology Data Exchange (ETDEWEB)

    Fiebig, Michael [OSRAM Opto Semicondutors GmbH, Muenchen (Germany). Bereich Marketing und Business Development

    2010-07-01

    Light bulbs leave the European market step by step. These conventional light sources are too inefficient in the private and conventional sector. There are a lot of alternatives to light bulbs. But no technology will be able to save as much energy as light emitting diodes (LED) in the future. Today, these LEDs meet us in most different applications. Continuously new areas of application are opened up in order to reduce the power requirement clearly for the production of artificial light. Apart from energy conservation diodes also enable untold possibilities. In the future, light can be still more flexibly used owing to LED. LEDs are ideal light sources for planners and designers.

  17. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, Part 3: LED Environmental Testing

    Energy Technology Data Exchange (ETDEWEB)

    Tuenge, Jason R.; Hollomon, Brad; Dillon, Heather E.; Snowden-Swan, Lesley J.

    2013-03-01

    This report covers the third part of a larger U.S. Department of Energy (DOE) project to assess the life-cycle environmental and resource impacts in the manufacturing, transport, use, and disposal of light-emitting diode (LED) lighting products in relation to incumbent lighting technologies. All three reports are available on the DOE website (www.ssl.energy.gov/tech_reports.html). • Part 1: Review of the Life-Cycle Energy Consumption of Incandescent, Compact Fluorescent and LED Lamps; • Part 2: LED Manufacturing and Performance; • Part 3: LED Environmental Testing. Parts 1 and 2 were published in February and June 2012, respectively. The Part 1 report included a summary of the life-cycle assessment (LCA) process and methodology, provided a literature review of more than 25 existing LCA studies of various lamp types, and performed a meta-analysis comparing LED lamps with incandescent and compact fluorescent lamps (CFLs). Drawing from the Part 1 findings, Part 2 performed a more detailed assessment of the LED manufacturing process and used these findings to provide a comparative LCA taking into consideration a wider range of environmental impacts. Both reports concluded that the life-cycle environmental impact of a given lamp is dominated by the energy used during lamp operation—the upstream generation of electricity drives the total environmental footprint of the product. However, a more detailed understanding of end-of-life disposal considerations for LED products has become increasingly important as their installation base has grown. The Part 3 study (reported herein) was undertaken to augment the LCA findings with chemical analysis of a variety of LED, CFL, and incandescent lamps using standard testing procedures. A total of 22 samples, representing 11 different models, were tested to determine whether any of 17 elements were present at levels exceeding California or Federal regulatory thresholds for hazardous waste. Key findings include: • The selected

  18. The evolution of human sleep: Technological and cultural innovation associated with sleep-wake regulation among Hadza hunter-gatherers.

    Science.gov (United States)

    Samson, David R; Crittenden, Alyssa N; Mabulla, Ibrahim A; Mabulla, Audax Z P

    2017-12-01

    Sleep is necessary for the survival of all mammalian life. In humans, recent investigations have generated critical data on the relationship between sleep and ecology in small-scale societies. Here, we report the technological and social strategies used to alter sleep environments and influence sleep duration and quality among a population of hunter-gatherers, the Hadza of Tanzania. Specifically, we investigated the effects that grass huts, sound levels, and fire had on sleep. We quantitatively compared thermal stress in outdoor environments to that found inside grass hut domiciles to test whether the huts function as thermoregulated microhabitats during the rainy season. Using physiological equivalent temperature (PET), we found that the grass huts provide sleep sites with less overall variation in thermal stress relative to outside baseline environments. We also investigated ambient acoustic measures of nighttime environments and found that sound significantly covaried with sleep-wake activity, with greater sound levels associating with less sleep. Finally, after controlling for ecological variables previously shown to influence sleep in this population, fire was shown to neither facilitate nor discourage sleep expression. Insofar as data among contemporary sub-tropical foragers can inform our understanding of past lifeways, we interpret our findings as suggesting that after the transition to full time terrestriality, it is likely that early Homo would have had novel opportunities to manipulate its environments in ways that could have significantly improved sleep quality. We further conclude that control over sleep environment would have been essential for migration to higher latitudes away from equatorial Africa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. On the switching speed of SOI LEDs

    NARCIS (Netherlands)

    Schmitz, Jurriaan; de Vries, R.; Salm, Cora; Hoang, T.; Hueting, Raymond Josephus Engelbart; Holleman, J.

    2008-01-01

    Recently, we presented a novel design for a silicon LED in SmartCUT™ SOI wafers. It exhibits a record quantum efficiency for SOI-based silicon LEDs and opens the way to the integration of light emitters in a VLSI process on SOI. In this paper, we present first experimental and modeling results

  20. Led-licht biedt mogelijkheden in broeierij

    NARCIS (Netherlands)

    Neefjes, H.; PPO Bomen-bollen,

    2010-01-01

    Onderzoekers van PPO Lisse hebben de mogelijkheden van led-licht verkend bij met name lelie en tulp. Bij lelie bieden leds perspectief in de voortrek. Tulp kan er bijna de hele broeifase van profiteren. Veel licht is niet nodig, maar meerlagenteelt is een voorwaarde.

  1. Reduced Component Count RGB LED Driver

    NARCIS (Netherlands)

    De Pedro, I.; Ackermann, B.

    2008-01-01

    The goal of this master thesis is to develop new drive and contrololutions, for creating white light from mixing the light of different-color LEDs, aiming at a reduced component count resulting in less space required by the electronics and lower cost. It evaluates the LED driver concept proposed in

  2. Led Zeppelin reklaamib Narvat / Anti Ronk

    Index Scriptorium Estoniae

    Ronk, Anti

    2007-01-01

    Ilmus Narva-teemaline kahest CD-st koosnev album, kus ühel plaadil on 60 minutit videot linna vaatamisväärsuste ja informatsiooniga, teisel - briti rockansambli Led Zeppelini teosed Narva sümfooniaorkestri ja rockansambli Led R esituses

  3. High Performance Green LEDs by Homoepitaxial

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian; Schubert, E Fred

    2009-11-22

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

  4. White LEDs with limit luminous efficacy

    Science.gov (United States)

    Lisitsyn, V. M.; Lukash, V. S.; Stepanov, S. A.; Yangyang, Ju

    2016-01-01

    In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated.

  5. White LEDs with limit luminous efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Lisitsyn, V. M.; Stepanov, S. A., E-mail: stepanovsa@tpu.ru; Yangyang, Ju [National Research Tomsk Polytechnic University, 30 Lenin Av., Tomsk, 634050 (Russian Federation); Lukash, V. S. [JSC Research Institute of Semiconductor Devices, 99a Krasnoarmeyskaja St., Tomsk, 634050 (Russian Federation)

    2016-01-15

    In most promising widespread gallium nitride based LEDs emission is generated in the blue spectral region with a maximum at about 450 nm which is converted to visible light with the desired spectrum by means of phosphor. The thermal energy in the conversion is determined by the difference in the energies of excitation and emission quanta and the phosphor quantum yield. Heat losses manifest themselves as decrease in the luminous efficacy. LED heating significantly reduces its efficiency and life. In addition, while heating, the emission generation output and the efficiency of the emission conversion decrease. Therefore, the reduction of the energy losses caused by heating is crucial for LED development. In this paper, heat losses in phosphor-converted LEDs (hereinafter chips) during spectrum conversion are estimated. The limit values of the luminous efficacy for white LEDs are evaluated.

  6. Harmonics Monitoring Survey on LED Lamps

    Directory of Open Access Journals (Sweden)

    Abdelrahman Ahmed Akila

    2017-03-01

    Full Text Available Light Emitting Diode (LED lamps are being increasingly used in many applications. These LED lamps operate using a driver, which is a switching device. Hence, LED lamps will be a source of harmonics in the power system. These harmonics if not well treated, may cause severe performance and operational problems. In this paper, harmonics (amplitude and phase angles generated by both LED lamps and conventional fluorescent lamps will be studied practically. Then they will be analyzed and evaluated. Compared to each other harmonics generated by both LED and conventional florescent lamps, self mitigation may occur based on the phase angle of these harmonics. All data will be measured using power analyzer and will be done on a sample of actual lamps.

  7. Spatial layout optimization design of multi-type LEDs lighting source based on photoelectrothermal coupling theory

    Science.gov (United States)

    Xue, Lingyun; Li, Guang; Chen, Qingguang; Rao, Huanle; Xu, Ping

    2018-03-01

    Multiple LED-based spectral synthesis technology has been widely used in the fields of solar simulator, color mixing, and artificial lighting of plant factory and so on. Generally, amounts of LEDs are spatially arranged with compact layout to obtain the high power density output. Mutual thermal spreading among LEDs will produce the coupled thermal effect which will additionally increase the junction temperature of LED. Affected by the Photoelectric thermal coupling effect of LED, the spectrum of LED will shift and luminous efficiency will decrease. Correspondingly, the spectral synthesis result will mismatch. Therefore, thermal management of LED spatial layout plays an important role for multi-LEDs light source system. In the paper, the thermal dissipation network topology model considering the mutual thermal spreading effect among the LEDs is proposed for multi-LEDs system with various types of power. The junction temperature increment cased by the thermal coupling has the great relation with the spatial arrangement. To minimize the thermal coupling effect, an optimized method of LED spatial layout for the specific light source structure is presented and analyzed. The results showed that layout of LED with high-power are arranged in the corner and low-power in the center. Finally, according to this method, it is convenient to determine the spatial layout of LEDs in a system having any kind of light source structure, and has the advantages of being universally applicable to facilitate adjustment.

  8. LEDs in automotive lighting and signaling: a customer point of view

    Science.gov (United States)

    Berlitz, Stephan; Heider, Christian

    2007-09-01

    The development of brand specific front and tail lights in cooperation with the stylists is the assignment of automobile lighting. Highest car safety, attractive styling, differentiation in the traffic situation and environment friendliness are the project limits. LED technology has the potential to extend these limits. The LED technology will have to improve, but it is also enhanced by new sensor technologies that introduce new functionalities. The implementation of a possible roadmap depends on right technologies at the right time. For new styling ideas and functional innovations further steps in lighting technology are necessary. The document will show a car makers view on possible innovation ideas.

  9. LED tests TTO 2010-2011. Focus on energy. Final report; LED Proeven TTO 2010-2011. Focus op energie. Eindverslag

    Energy Technology Data Exchange (ETDEWEB)

    Peekstok, T.; Duyvesteijn, R.; Persoon, S.; Sanders, J.; De Jong, A. [Tuinbouw Techniek Ontwikkeling TTO, Honselersdijk (Netherlands)

    2011-07-15

    An overview is given of research results of the application of LED in the horticulture, focusing on high-growing vegetable crops. In this report LED illuminance research for tomatoes is outlined. The project has been carried out from October 2010 to May 2011 in the demonstration nursery Westland. Also, briefly attention is paid to LED lighting tests, performed by TTO (Horticulture Technology Development) in 2008 and 2009 [Dutch] Een overzicht wordt gegeven van de onderzoeksresultaten in de toepassing van LED belichting in de glastuinbouw, met nadruk op hoogopgaande groentegewassen. In dit verslag wordt het onderzoek met LED belichting in tomaat van telersvereniging 'Tuinbouw Techniek Ontwikkeling' (TTO) uiteengezet. Dit project heeft plaatsgevonden vanaf oktober 2010 tot mei 2011 in de Demokwekerij Westland. Hiernaast worden de proeven met LED belichting, welke uitgevoerd zijn door TTO in 2008 en 2009, kort samengevat.

  10. The mineral phase evolution behaviour in the production of glass-ceramics from municipal solid waste incineration fly ash by melting technology.

    Science.gov (United States)

    Luan, Jingde; Chai, Meiyun; Li, Rundong; Yao, Pengfei; Khan, Agha Saood

    2016-01-01

    High energy consumption was the major obstacle to the widespread application of melting technology in the treatment of municipal solid waste incineration fly ash. Aiming to lower the ash-melting temperature (AMT) for energy-saving, differential scanning calorimetry, X-ray diffraction and the scanning electron microscope were used to investigate the relations between AMT and the mineral evolution. The results indicated that the change of AMT was determined by the types and the contents of mineral crystals. The transition from refractory minerals to fluxing minerals was the key. The transition of the main crystalline phase from pseudowollastonite (Ca3(Si3O9)) to wollastonite (CaSiO3) played a significant role in AMT reduction. A quantum chemistry calculation was carried out to investigate the effect of crystal reaction activity on AMT. In the chemical reaction, the highest occupied molecular orbital and the lowest unoccupied molecular orbital played a more important role than any other orbits. Cations (Ca(2+), Mg(2+), Na(+), K(+)) were apt to enter into the crystal lattice of wollastonite and gehlenite mainly through Si (3), O (1), Si (6), O (10) and Al (2), O (10), and broke the covalent bonds of Si (3)-O (7), Al (1)-O (9) and Al (1)-O (15), respectively. This deconstruction behaviour provided convenient conditions for restructuring and promoted the formation of fluxing minerals. In melts, the excess SiO2 monomers which existed in the form of cristobalite and quartz caused AMT increase.

  11. FREQUENCY CHARACTERISTICS OF MODERN LED PHOSPHOR MATERIALS

    Directory of Open Access Journals (Sweden)

    Maxim S. Fudin

    2014-11-01

    Full Text Available Frequency characteristics of modern LED phosphor materials have been considered for the purpose of assessing the prospects of phosphor-based LEDs in wireless communication data systems which use optical wavelengths. The measurements have been carried out on the dependence of the emission intensity of single LEDs and LED chip-on-board modules with phosphors based on yttrium-aluminum and lutetium-aluminum garnets (with or without addition of nitridebased phosphors as well as silicate-based phosphors, on the frequency of electric pulses exciting the emission. It was shown that from the point of view of data transmission rate, garnet-based phosphors (including systems with added nitride phosphors are more promising than silicate–based ones. Garnet-based materials can be used in optical communication data systems with bandwidth (without extra modulation applied up to 3 MHz with single–chip LEDs and up to 4.5 MHz with 9- chip LED chip-on-board modules. The results of the work indicate that a significant part of white LEDs used in general lighting systems can be even now used for data transfer, for example, in systems assisting positioning in closed spaces to facilitate people searching necessary rooms or objects

  12. Non-Destructive Inspection Methods for LEDs Using Real-Time Displaying Optical Coherence Tomography

    OpenAIRE

    Suhwan Kim; Jeehyun Kim; Unsang Jung; Nam Hyun Cho

    2012-01-01

    In this study, we report the applicability of two different Optical Coherence Tomography (OCT) technologies for inspecting Light Emitting Diode (LED) structures. Sectional images of a LED were captured using a Spectral Domain OCT (SD-OCT) system and a Swept Source OCT (SS-OCT) system. Their center wavelengths are 850 and 1,310 nm, respectively. We acquired cross-sectional two dimensional (2D) images of a normal LED and extracted sectional profiles to inspect possible wire disconnection that m...

  13. Kansas highway LED illumination manual : a guide for the use of LED lighting systems.

    Science.gov (United States)

    2015-12-01

    The research project was aimed to assist the Kansas Department of Transportation (KDOT) in the development of a Highway LED Illumination Manual for guiding the upcoming implementation of successful LED roadway lighting systems in Kansas to replace th...

  14. Kansas highway LED illumination manual : a guide for the use of LED lighting systems : [technical summary].

    Science.gov (United States)

    2015-12-01

    The research project was aimed to assist the Kansas Department of Transportation (KDOT) in the development of a Highway LED Illumination Manual for guiding the upcoming implementation of successful LED roadway lighting systems in Kansas to replace th...

  15. LED traffic signal management system : final report.

    Science.gov (United States)

    2016-06-01

    This research originated from the opportunity to develop a methodology to assess when LED (Light Emitting Diode) traffic signal modules begin to fail to meet the Institute of Transportation Engineers (ITE) performance specification for luminous inten...

  16. LED til væksthuse

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten; Thorseth, Anders; Rosenqvist, Eva

    2012-01-01

    Den teknologiske udvikling indenfor Lys Emitterende Dioder (LED) går imod stadig større lysmængder og stadig større effektivitet. Kombineret med fordele som lang levetid, dæmpbarhed og ingen varmestråling gør det, at LED baserede lyskilder/lamper i stigende grad benyttes til belysningsformål og kan...

  17. Cost and energy-efficient (LED, induction and plasma) roadway lighting.

    Science.gov (United States)

    2013-11-01

    There is an increasing interest in using new lighting technologies such as light emitting diode (LED), Induction, and Plasma light sources : in roadway lighting. The most commonly claimed benefits of the new lighting systems include increased reliabi...

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

    Science.gov (United States)

    2004-01-01

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

  19. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  20. Experiment of solidifying photo sensitive polymer by using UV LED

    Science.gov (United States)

    Kang, Byoung Hun; Shin, Sung Yeol

    2008-11-01

    The development of Nano/Micro manufacturing technologies is growing rapidly and in the same manner, the investments in these areas are increasing. The applications of Nano/Micro technologies are spreading out to semiconductor production technology, biotechnology, environmental engineering, chemical engineering and aerospace. Especially, SLA is one of the most popular applications which is to manufacture 3D shaped microstructure by using UV laser and photo sensitive polymer. To make a high accuracy and precision shape of microstructures that are required from the diverse industrial fields, the information of interaction relationship between the photo resin and the light source is necessary for further research. Experiment of solidifying photo sensitive polymer by using UV LED is the topic of this paper and the purpose of this study is to find out what relationships do the reaction of the resin have in various wavelength, power of the light and time.

  1. LEDS GP Success Story: Fostering Coordinated LEDS Support in Kenya (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-03-01

    The LEDS Global Partnership (LEDS GP) strives to advance climate-resilient, low-emission development through catalyzing collaboration, information exchange, and action on the ground. The Government of Kenya is a key LEDS GP member and offers an inspiring example of how LEDS GP is having an impact globally. The 2012 LEDS Collaboration in Action workshop in London provided an interactive space for members to share experiences on cross-ministerial LEDS leadership and to learn about concrete development impacts of LEDS around the world. Inspired by these stories, the Kenya's Ministry of State for Planning, National Development and Vision 2030 (MPND) began to collaborate closely with the Ministry of Environment and Mineral Resources to create strong links between climate change action and development in the country, culminating in the integration of Kenya's National Climate Change Action Plan and the country's Medium Term Development Plan.

  2. Fundamentals of solid-state lighting LEDs, OLEDs, and their applications in illumination and displays

    CERN Document Server

    Khanna, Vinod Kumar

    2014-01-01

    History and Basics of LightingChronological History of LightingLearning Objectives How Early Man Looked at the ""Sun"" The Need for Artificial Light Sources First Steps in the Evolution of Artificial Lighting The First Solid-State Lighting Device The First Practical Electrical Lighting Device The Incandescent Filament Lamp Mercury and Sodium Vapor Lamps The Fluorescent Lamp The Compact Fluorescent Lamp Revolution in the World of Lighting: Advent of Light-Emitting Diodes Birth of the First LED and the Initial Stages of LED Development The Father of the LED: Holonyak Jr. The Post-1962 Developmen

  3. Proposed evolution technologies for Bluetooth

    OpenAIRE

    Arumugam, AK; Armour, SMD; Tariq, MF; Nix, AR

    2001-01-01

    This paper begins by highlighting key features of the Bluetooth baseband standard. Software simulated results for the transmission of symmetric asynchronous data link (ACL)packets are used to discuss bit rate capabilities of various timebounded and non-time bounded Bluetooth enabled consumer electronic devices. The investigation considers Bluetooth data medium (DM) and data high (DH) packet types. To meet the bit rate needs of future consumer electronic devices, BPSK, QPSK and 16-QAM are prop...

  4. High-power UV-B LEDs with long lifetime

    Science.gov (United States)

    Rass, Jens; Kolbe, Tim; Lobo-Ploch, Neysha; Wernicke, Tim; Mehnke, Frank; Kuhn, Christian; Enslin, Johannes; Guttmann, Martin; Reich, Christoph; Mogilatenko, Anna; Glaab, Johannes; Stoelmacker, Christoph; Lapeyrade, Mickael; Einfeldt, Sven; Weyers, Markus; Kneissl, Michael

    2015-03-01

    UV light emitters in the UV-B spectral range between 280 nm and 320 nm are of great interest for applications such as phototherapy, gas sensing, plant growth lighting, and UV curing. In this paper we present high power UV-B LEDs grown by MOVPE on sapphire substrates. By optimizing the heterostructure design, growth parameters and processing technologies, significant progress was achieved with respect to internal efficiency, injection efficiency and light extraction. LED chips emitting at 310 nm with maximum output powers of up to 18 mW have been realized. Lifetime measurements show approximately 20% decrease in emission power after 1,000 operating hours at 100 mA and 5 mW output power and less than 30% after 3,500 hours of operation, thus indicating an L50 lifetime beyond 10,000 hours.

  5. The origins of the Acheulean: past and present perspectives on a major transition in human evolution.

    Science.gov (United States)

    de la Torre, Ignacio

    2016-07-05

    The emergence of the Acheulean from the earlier Oldowan constitutes a major transition in human evolution, the theme of this special issue. This paper discusses the evidence for the origins of the Acheulean, a cornerstone in the history of human technology, from two perspectives; firstly, a review of the history of investigations on Acheulean research is presented. This approach introduces the evolution of theories throughout the development of the discipline, and reviews the way in which cumulative knowledge led to the prevalent explanatory framework for the emergence of the Acheulean. The second part presents the current state of the art in Acheulean origins research, and reviews the hard evidence for the appearance of this technology in Africa around 1.7 Ma, and its significance for the evolutionary history of Homo erectusThis article is part of the themed issue 'Major transitions in human evolution'. © 2016 The Author(s).

  6. Application of ultraviolet light-emitting diodes (UV-LEDs) for water disinfection: A review.

    Science.gov (United States)

    Song, Kai; Mohseni, Madjid; Taghipour, Fariborz

    2016-05-01

    Ultraviolet (UV) disinfection is an effective technology for the inactivation of pathogens in water and is of growing interest for industrial application. A new UV source - ultraviolet light-emitting diode (UV-LED) - has emerged in the past decade with a number of advantages compared to traditional UV mercury lamps. This promising alternative raises great interest in the research on application of UV-LEDs for water treatment. Studies on UV-LED water disinfection have increased during the past few years. This article presents a comprehensive review of recent studies on UV-LEDs with various wavelengths for the inactivation of different microorganisms. Many inconsistent and incomparable data were found from published studies, which underscores the importance of establishing a standard protocol for studying UV-LED inactivation of microorganisms. Different UV sensitivities to UV-LEDs and traditional UV lamps were observed in the literature for some microorganisms, which requires further investigation for a better understanding of microorganism response to UV-LEDs. The unique aspects of UV-LEDs improve inactivation effectiveness by applying LED special features, such as multiple wavelengths and pulsed illumination; however, more studies are needed to investigate the influencing factors and mechanisms. The special features of UV-LEDs offer the flexibility of novel reactor designs for a broad application of UV-LED reactors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Zernike polynomials for photometric characterization of LEDs

    International Nuclear Information System (INIS)

    Velázquez, J L; Ferrero, A; Pons, A; Campos, J; Hernanz, M L

    2016-01-01

    We propose a method based on Zernike polynomials to characterize photometric quantities and descriptors of light emitting diodes (LEDs) from measurements of the angular distribution of the luminous intensity, such as total luminous flux, BA, inhomogeneity, anisotropy, direction of the optical axis and Lambertianity of the source. The performance of this method was experimentally tested for 18 high-power LEDs from different manufacturers and with different photometric characteristics. A small set of Zernike coefficients can be used to calculate all the mentioned photometric quantities and descriptors. For applications not requiring a great accuracy such as those of lighting design, the angular distribution of the luminous intensity of most of the studied LEDs can be interpolated with only two Zernike polynomials. (paper)

  8. White LED phosphors: the next step

    Science.gov (United States)

    Yamamoto, Hajime

    2010-02-01

    Application of white LEDs is extended toward high-output light sources, e.g. for automotive headlights, and better spectral matching with optical filters for LCD backlighting. To meet such new demands, phosphor materials have been investigated with focus on their luminescence spectra, temperature characteristics and reliability. The conventional yellow phosphor based on Y3Al5O12:Ce3+ has excellent performance as a single phosphor combined with a blue LED. More recently developed nitrido- or oxonitrido-silicates activated with Eu2+ are also promising materials showing green to red luminescence depending on a composition and high thermal and chemical stability. And yet, demands for specific application have been made clear and strong. This paper reviews the present status and challenging goals of phosphors in the next stage further to make progress in white LEDs.

  9. Evolution of Seigniorage in a Period of Profound Economic Transformations

    Directory of Open Access Journals (Sweden)

    Manuel Bernal Garzón

    2015-01-01

    Full Text Available This paper presents an analysis of seigniorage in Colombia in the period 1984-2013, which is characterized by profound technological advances and a number of political, social and cultural events worldwide affecting both global and national economies. These changes, together with modifications in the principles of economic thinking in policy managers, under the pressure of multilateral lending agencies and due to new realities, have led to a series of structural reforms that generated institutional changes both in exchange rate and financial regimes affecting monetary policy, and, therefore, the behavior of primary and secondary seigniorage. Finally, the relationship between these changes and the evolution of seigniorage is addressed.

  10. LED module with high index lens

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-09-05

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

  11. Intelligent styring af dynamisk LED belysning

    DEFF Research Database (Denmark)

    Thorseth, Anders; Corell, Dennis Dan; Hansen, Søren Stentoft

    Denne slutrapport giver en kort beskrivelse af arbejdet, der er udført af DTU Fotonik i projektet ”Intelligent styring af dynamisk LED belysning” støttet af EUDP. Arbejdet er udført i perioden 2011‐2012 i samarbejde med Lighten.......Denne slutrapport giver en kort beskrivelse af arbejdet, der er udført af DTU Fotonik i projektet ”Intelligent styring af dynamisk LED belysning” støttet af EUDP. Arbejdet er udført i perioden 2011‐2012 i samarbejde med Lighten....

  12. Final report LED solutions for public lighting; Eindrapportage LED oplossingen voor openbare verlichting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-04-15

    This report examines if and how LED can be used for public lighting on a large scale. Pilot projects in 29 municipalities were assessed to test the usefulness of LED lighting. This final report provides answers to the questions that relate to the feasibility of the deployment of LED in public lighting and provides some practical pointers. [Dutch] Er is onderzocht of, en zo ja op welke wijze, LED grootschalig toegepast kan worden in de openbare verlichting (OVL). In 29 gemeenten in Nederland zijn proefprojecten geevalueerd om LED verlichting te toetsen op bruikbaarheid. Deze eindrapportage geeft antwoord op vragen die betrekking hebben op de haalbaarheid van de toepassing van LED binnen de OVL en geeft wat praktische aandachtspunten.

  13. Design of the control system for full-color LED display based on MSP430 MCU

    Science.gov (United States)

    Li, Xue; Xu, Hui-juan; Qin, Ling-ling; Zheng, Long-jiang

    2013-08-01

    The LED display incorporate the micro electronic technique, computer technology and information processing as a whole, it becomes the most preponderant of a new generation of display media with the advantages of bright in color, high dynamic range, high brightness and long operating life, etc. The LED display has been widely used in the bank, securities trading, highway signs, airport and advertising, etc. According to the display color, the LED display screen is divided into monochrome screen, double color display and full color display. With the diversification of the LED display's color and the ceaseless rise of the display demands, the LED display's drive circuit and control technology also get the corresponding progress and development. The earliest monochrome screen just displaying Chinese characters, simple character or digital, so the requirements of the controller are relatively low. With the widely used of the double color LED display, the performance of its controller will also increase. In recent years, the full color LED display with three primary colors of red, green, blue and grayscale display effect has been highly attention with its rich and colorful display effect. Every true color pixel includes three son pixels of red, green, blue, using the space colour mixture to realize the multicolor. The dynamic scanning control system of LED full-color display is designed based on MSP430 microcontroller technology of the low power consumption. The gray control technology of this system used the new method of pulse width modulation (PWM) and 19 games show principle are combining. This method in meet 256 level grayscale display conditions, improves the efficiency of the LED light device, and enhances the administrative levels feels of the image. Drive circuit used 1/8 scanning constant current drive mode, and make full use of the single chip microcomputer I/O mouth resources to complete the control. The system supports text, pictures display of 256 grayscale

  14. Exploring Service-led Growth Trajectories for Analytical Equipment Providers

    DEFF Research Database (Denmark)

    Raja, Jawwad; Frandsen, Thomas; Mouritsen, Jan

    2016-01-01

    This paper examines the dilemmas encountered by advanced analytical equipment providers in developing service-led growth strategies to expand their business in pursuit of more attractive revenue models. It does so by adopting a case based research approach. The findings detail the capabilities...... required to provide advanced services within customers’ R&D functions, while simultaneously attempting to scale these for a production context. The emergent complexities of operating in multiple arenas in order to explore and exploit technologies-along the three trajectories of serviceability, scalability...

  15. A lifetime prediction method for LEDs considering mission profiles

    DEFF Research Database (Denmark)

    Qu, Xiaohui; Wang, Huai; Zhan, Xiaoqing

    2016-01-01

    and to benchmark the cost-competitiveness of different lighting technologies. The existing lifetime data released by LED manufacturers or standard organizations are usually applicable only for specific temperature and current levels. Significant lifetime discrepancies may be observed in field operations due...... to the varying operational and environmental conditions during the entire service time (i.e., mission profiles). To overcome the challenge, this paper proposes an advanced lifetime prediction method, which takes into account the field operation mission profiles and the statistical properties of the life data...

  16. A Lifetime Prediction Method for LEDs Considering Real Mission Profiles

    DEFF Research Database (Denmark)

    Qu, Xiaohui; Wang, Huai; Zhan, Xiaoqing

    2017-01-01

    and to benchmark the cost-competitiveness of different lighting technologies. However, the existing lifetime data released by LED manufacturers or standard organizations are usually applicable only for some specific temperature and current levels. Significant lifetime discrepancies may be seen in the field...... operations due to the varying operational and environmental conditions during the entire service time (i.e., mission profiles). To overcome the challenge, this paper proposes an advanced lifetime prediction method, which takes into account the field operation mission profiles and also the statistical...

  17. Nitride micro-LEDs and beyond--a decade progress review.

    Science.gov (United States)

    Jiang, H X; Lin, J Y

    2013-05-06

    Since their inception, micro-size light emitting diode (µLED) arrays based on III-nitride semiconductors have emerged as a promising technology for a range of applications. This paper provides an overview on a decade progresses on realizing III-nitride µLED based high voltage single-chip AC/DC-LEDs without power converters to address the key compatibility issue between LEDs and AC power grid infrastructure; and high-resolution solid-state self-emissive microdisplays operating in an active driving scheme to address the need of high brightness, efficiency and robustness of microdisplays. These devices utilize the photonic integration approach by integrating µLED arrays on-chip. Other applications of nitride µLED arrays are also discussed.

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

    KAUST Repository

    Huang, B. J.

    2010-06-01

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

  19. LED structure with enhanced mirror reflectivity

    Science.gov (United States)

    Bergmann, Michael; Donofrio, Matthew; Heikman, Sten; Schneider, Kevin S; Haberern, Kevin W; Edmond, John A

    2014-04-01

    Embodiments of the present invention are generally related to LED chips having improved overall emission by reducing the light-absorbing effects of barrier layers adjacent mirror contacts. In one embodiment, a LED chip comprises one or more LEDs, with each LED having an active region, a first contact under the active region having a highly reflective mirror, and a barrier layer adjacent the mirror. The barrier layer is smaller than the mirror such that it does not extend beyond the periphery of the mirror. In another possible embodiment, an insulator is further provided, with the insulator adjacent the barrier layer and adjacent portions of the mirror not contacted by the active region or by the barrier layer. In yet another embodiment, a second contact is provided on the active region. In a further embodiment, the barrier layer is smaller than the mirror such that the periphery of the mirror is at least 40% free of the barrier layer, and the second contact is below the first contact and accessible from the bottom of the chip.

  20. LED Lighting in a Performing Arts Building

    Energy Technology Data Exchange (ETDEWEB)

    Miller, N. J.; Kaye, S. M. [Univ. of Florida, Gainesville, FL (United States); Coleman, P. M. [Univ. of Florida, Gainesville, FL (United States); Wilkerson, A. M.; Perrin, T. E.; Sullivan, G. P. [Efficiency Solutions, Inc., Richland, WA (United States)

    2014-07-31

    At the University of Florida in Gainesville, the DOE Solid-State Lighting GATEWAY program evaluated LED architectural and theatrical lighting in four academic/performance-related spaces within the Nadine McGuire Theatre + Dance Pavilion. Due to a wise choice of products and luminaire light distributions, the change brought significant quality improvements including improved controllability and color.

  1. Preliminary investigations of piezoelectric based LED luminary

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Andersen, Michael A. E.; Meyer, Kaspar Sinding

    2011-01-01

    This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS’s (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits...

  2. Photobiocatalytic alcohol oxidation using LED light sources

    NARCIS (Netherlands)

    Rauch, M.C.R.; Schmidt, S.; Arends, I.W.C.E.; oppelt, K.; Kara, S; Hollmann, F.

    2016-01-01

    The photocatalytic oxidation of NADH using a flavin photocatalyst and a simple blue LED light source is reported. This in situ NAD+ regeneration system can be used to promote biocatalytic, enantioselective oxidation reactions. Compared to the traditional use of white light bulbs this method enables

  3. Child-Led Enquiry in Primary Science

    Science.gov (United States)

    Dunlop, Lynda; Compton, Kirsty; Clarke, Linda; McKelvey-Martin, Valerie

    2015-01-01

    This research describes and evaluates the application of a child-led approach to scientific enquiry (the Community of Scientific Enquiry, CoSE) to children aged 8-11 (Key Stage 2) in Northern Ireland. Primary teachers were introduced to CoSE at a workshop and asked to evaluate its implementation with their class. Results from children (n = 364)…

  4. LED light recycling using double prisms

    Science.gov (United States)

    Ouyang, George; Li, Kenneth

    2013-09-01

    A novel LED recycling scheme using double prisms is presented. Two identical triangular prisms with square bases, one cross-stacked on top of the other, are tight-fit into a mirrored light tunnel. The whole prism/light tunnel assembly is then mounted on top of a square LED source, whose emitting area is the same as that of the base plane of the said prism/light tunnel assembly. Each prism acts as a tapered-down light guide in one dimension, which selectively retro-reflects high angle light along that direction. The outer light tunnel serves as a mirrored wall that folds back any light that escapes outside the two prisms. For a given collection cone angle, the height of the two prisms is optimized using ASAP, a commercial ray-tracing software. Simulation and experimental results show promise in significantly increasing the brightness of the LED sources within the collection cone. Specifically for a 4x recycling ratio a 70% recycling gain in center illuminance has been achieved (i.e., illuminance measured in the forward direction). This scheme has advantages over previous recycling configurations due to its compactness and ease of mounting. For example, compared to Wavien's spherical reflector approach that has been previously published, the current recycling configuration is much smaller in size because instead of fitting a much larger mirrored reflector on top of the LED source, this time we're using a structure that has the same lateral dimensions as those of the LED source itself. Further improvement is also possible if optimization of various system parameters is carried out.

  5. Evolution of Ore Deposits and Technology Transfer Project: Isotope and Chemical Methods in Support of the U.S. Geological Survey Science Strategy, 2003-2008

    Science.gov (United States)

    Rye, Robert O.; Johnson, Craig A.; Landis, Gary P.; Hofstra, Albert H.; Emsbo, Poul; Stricker, Craig A.; Hunt, Andrew G.; Rusk, Brian G.

    2010-01-01

    Principal functions of the U.S. Geological Survey (USGS) Mineral Resources Program are providing assessments of the location, quantity, and quality of undiscovered mineral deposits, and predicting the environmental impacts of exploration and mine development. The mineral and environmental assessments of domestic deposits are used by planners and decisionmakers to improve the stewardship of public lands and public resources. Assessments of undiscovered mineral deposits on a global scale reveal the potential availability of minerals to the United States and other countries that manufacture goods imported to the United States. These resources are of fundamental relevance to national and international economic and security policy in our globalized world economy. Performing mineral and environmental assessments requires that predictions be made of the likelihood of undiscovered deposits. The predictions are based on geologic and geoenvironmental models that are constructed for the diverse types of mineral deposits from detailed descriptions of actual deposits and detailed understanding of the processes that formed them. Over the past three decades the understanding of ore-forming processes has benefited greatly from the integration of laboratory-based geochemical tools with field observations and other data sources. Under the aegis of the Evolution of Ore Deposits and Technology Transfer Project (referred to hereinafter as the Project), a 5-year effort that terminated in 2008, the Mineral Resources Program provided state-of-the-art analytical capabilities to support applications of several related geochemical tools to ore-deposit-related studies. The analytical capabilities and scientific approaches developed within the Project have wide applicability within Earth-system science. For this reason the Project Laboratories represent a valuable catalyst for interdisciplinary collaborations of the type that should be formed in the coming years for the United States to meet

  6. CooLED - efficient LED bulbs with custrom optics - final report

    DEFF Research Database (Denmark)

    Wolff, Jesper; Corell, Dennis Dan; Dam-Hansen, Carsten

    Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet EUDP 64012-0226, CooLED – en ny generation LED Lyskilde for det tidsløse high-end marked....

  7. USE OF DNA TECHNOLOGY IN FORENSIC DENTISTRY

    Science.gov (United States)

    da Silva, Ricardo Henrique Alves; Sales-Peres, Arsenio; de Oliveira, Rogério Nogueira; de Oliveira, Fernando Toledo; Sales-Peres, Sílvia Helena de Carvalho

    2007-01-01

    The established importance of Forensic Dentistry for human identification, mainly when there is little remaining material to perform such identification (e.g., in fires, explosions, decomposing bodies or skeletonized bodies), has led dentists working with forensic investigation to become more familiar with the new molecular biology techniques. The currently available DNA tests have high reliability and are accepted as legal proofs in courts. This article presents a literature review referring to the main studies on Forensic Dentistry that involve the use of DNA for human identification, and makes an overview of the evolution of this technology in the last years, highlighting the importance of molecular biology in forensic sciences. PMID:19089123

  8. EDITORIAL: Micro-pixellated LEDs for science and instrumentation

    Science.gov (United States)

    Dawson, Martin D.; Neil, Mark A. A.

    2008-05-01

    This Cluster Issue of Journal of Physics D: Applied Physics highlights micro-pixellated gallium nitride light-emitting diodes or `micro-LEDs', an emerging technology offering considerable attractions for a broad range of scientific and instrumentation applications. It showcases the results of a Research Councils UK (RCUK) Basic Technology Research programme (http://bt-onethousand.photonics.ac.uk), running from 2004-2008, which has drawn together a multi-disciplinary and multi-institutional research partnership to develop these devices and explore their potential. Images of LEDs Examples of GaN micro-pixel LEDs in operation. Images supplied courtesy of the Guest Editors. The partnership, of physicists, engineers and chemists drawn from the University of Strathclyde, Heriot-Watt University, the University of Sheffield and Imperial College London, has sought to move beyond the established mass-market uses of gallium nitride LEDs in illumination and lighting. Instead, it focuses on specialised solid-state micro-projection devices the size of a match-head, containing up to several thousand individually-addressable micro-pixel elements emitting light in the ultraviolet or visible regions of the spectrum. Such sources are pattern-programmable under computer control and can project into materials fixed or high-frame rate optical images or spatially-controllable patterns of nanosecond excitation pulses. These materials can be as diverse as biological cells and tissues, biopolymers, photoresists and organic semiconductors, leading to new developments in optical microscopy, bio-sensing and chemical sensing, mask-free lithography and direct writing, and organic electronics. Particular areas of interest are multi-modal microscopy, integrated forms of organic semiconductor lasers, lab-on-a-chip, GaN/Si optoelectronics and hybrid inorganic/organic semiconductor structures. This Cluster Issue contains four invited papers and ten contributed papers. The invited papers serve to set

  9. LED i Københavns Kommunes gadebelysning

    DEFF Research Database (Denmark)

    Bülow, Katja

    2016-01-01

    Artiklen i denne udgivelse formidler resultatet af en undersøgelse, hvor de visuelle forhold i Københavns Kommunes gader undersøges som resultat af gadens belysning. Der lægges vægt på metoden bag undersøgelsen og på hvordan indførelsen af LED forandrer belysningen i gaderne.......Artiklen i denne udgivelse formidler resultatet af en undersøgelse, hvor de visuelle forhold i Københavns Kommunes gader undersøges som resultat af gadens belysning. Der lægges vægt på metoden bag undersøgelsen og på hvordan indførelsen af LED forandrer belysningen i gaderne....

  10. EVALUATING THE CULTURE-LED REGENERATION

    Directory of Open Access Journals (Sweden)

    D'Angelo Francesca

    2010-12-01

    Full Text Available The aim of the paper is to propose a new approach to urban planning, evaluating the culture-led regeneration processes. In the last few years, the cultural turn in urban planning played a central role in the urban studies. In this way we try to elaborate a more robust perspective interpreting the complex phenomenology emerging from the culture-led regeneration processes. Within the concept of complexity we discuss about the metabolic process that are the processes necessary to transform energy, material and information in goods and service functional to the complex urban system life. The approach that will be employed is the MuSIASEM that is based on several novel concept and an innovative methods never applied in this research field.

  11. 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.

  12. Notes on LED Installations in Street Illumination

    Directory of Open Access Journals (Sweden)

    Elisabeta Spunei

    2014-09-01

    Full Text Available The paper presents a study made on choosing LED street lighting installations, such that the quality requirements for exterior artificial lighting are fulfilled. We analyze two types of LED street lighting installations from a technical point of view, together with lighting level and brightness values obtained during the measurements. Following on the field measurements, the lighting quality parameters are calculated, and, for the lighting installation with the best performance, optimal mounting suggestions are made. The optimal quality parameters are calculated by simulations using the Dialux software. The same software and the same light sources we also compute an optimal street lighting by determining the size of the installation that provides the best lighting parameter values.

  13. Optical design of a LED searchlight system

    Science.gov (United States)

    Gong, Chen; Xu, Haiping; Liang, Jinhua; Liu, Yunfei; Yuan, Zengquan

    2018-01-01

    A 1200m visible searchlight system is designed based on photometry and application of geometric optics. To generate intensity distribution of this relatively powerful light beam we propose to use a high power LED and several refractive optical elements, which are composed of two plane-convex lenses and a conventional Fresnel lens. Two plane-convex lenses enable refraction of the side rays from the LED to the front direction which incident on the Fresnel lens. Fresnel lens, in its turn, concentrate the light flux and provide a nearly collimated beam to meet the requirement of forming a well-illuminated area across the road in the far field. Simulation data shows that this searchlight allow generating an appropriate illumination distribution for the long range requirements. A proof-of-concept prototype producing acceptable illuminance is developed.

  14. Distributed dimming control for LED lighting.

    Science.gov (United States)

    Lee, Sang Hyun; Kwon, Jae Kyun

    2013-11-04

    This paper presents a distributed energy-saving lighting strategy for the arrangements of a lighting network consisting of a group of light-emitting diode (LED) lamps and users. LED lamps have a dimming support feature to meet the illuminance requirements imposed by individual users. Both groups interact with each other via visible light communication (VLC) or other wireless communication features. This work aims to identify a configuration of lamps leading to the maximal energy saving in adaptive and distributed ways. To this end, a distributed assignment strategy is developed based on a message-passing framework where only local interactions among lamps and users are allowed for calculations and exchanges of the information on their status. The simulation results show that the proposed algorithm outperforms other distributed algorithms in a range of indoor lighting configurations.

  15. Lampu Pintar Berbasis LED Dengan Multi Sensor

    OpenAIRE

    Ramdan, Ade; Prajitno, Dicky Rianto; Herlan, Herlan; Gojali, Elli Ahmad

    2013-01-01

    In this paper, we propose a LED-based smart lamp prototype that integrated with sensor. The smart lamp use information of people and lighting confirmation, to turn on or turn off the lamp automatically. In addition, the sensor calculates and balances flash and ambient light exposure to decrease the light, so that can make energy efficiently in use. PIR (Passive Infrared Receiver) and Ultrasonic sensor is preferred to detect people condition in one place and LDR (Light Dependent Resistant) is ...

  16. Preliminary investigations of piezoelectric based LED luminary

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Andersen, Michael A. E.; Meyer, Kaspar Sinding

    2011-01-01

    This paper presents a preliminary study of PT (Piezoelectric Transformer) based SMPS’s (Switch Mode Power Supplies) for LED luminary. The unique properties of PTs (efficiency, power density and EMI) make them highly suitable for this application. Power stage topologies, rectifiers circuits, modul....... The prototype constitutes a light source equivalent to the 40 W incandescent bulb. Experimental results shows, that the prototype are capable of ZVS and dimming (the later trough use of burst mode control)....

  17. The evolving price of household LED lamps: Recent trends and historical comparisons for the US market

    Energy Technology Data Exchange (ETDEWEB)

    Gerke, Brian F.; Ngo, Allison T.; Alstone, Andrea L.; Fisseha, Kibret S.

    2014-10-14

    In recent years, household LED light bulbs (LED A lamps) have undergone a dramatic price decline. Since late 2011, we have been collecting data, on a weekly basis, for retail offerings of LED A lamps on the Internet. The resulting data set allows us to track the recent price decline in detail. LED A lamp prices declined roughly exponentially with time in 2011-2014, with decline rates of 28percent to 44percent per year depending on lumen output, and with higher-lumen lamps exhibiting more rapid price declines. By combining the Internet price data with publicly available lamp shipments indices for the US market, it is also possible to correlate LED A lamp prices against cumulative production, yielding an experience curve for LED A lamps. In 2012-2013, LED A lamp prices declined by 20-25percent for each doubling in cumulative shipments. Similar analysis of historical data for other lighting technologies reveals that LED prices have fallen significantly more rapidly with cumulative production than did their technological predecessors, which exhibited a historical decline of 14-15percent per doubling of production.

  18. UV LED lighting for automated crystal centring

    International Nuclear Information System (INIS)

    Chavas, Leonard M. G.; Yamada, Yusuke; Hiraki, Masahiko; Igarashi, Noriyuki; Matsugaki, Naohiro; Wakatsuki, Soichi

    2011-01-01

    A low-cost light-emitting diode (LED) UV source has been developed for facilitating macromolecular sample centring in the X-ray beam. A direct outcome of the exponential growth of macromolecular crystallography is the continuously increasing demand for synchrotron beam time, both from academic and industrial users. As more and more projects entail screening a profusion of sample crystals, fully automated procedures at every level of the experiments are being implemented at all synchrotron facilities. One of the major obstacles to achieving such automation lies in the sample recognition and centring in the X-ray beam. The capacity of UV light to specifically react with aromatic residues present in proteins or with DNA base pairs is at the basis of UV-assisted crystal centring. Although very efficient, a well known side effect of illuminating biological samples with strong UV sources is the damage induced on the irradiated samples. In the present study the effectiveness of a softer UV light for crystal centring by taking advantage of low-power light-emitting diode (LED) sources has been investigated. The use of UV LEDs represents a low-cost solution for crystal centring with high specificity

  19. Export-led Growth Hypothesis: Turkey Application

    Directory of Open Access Journals (Sweden)

    İsmail KÜÇÜKAKSOY

    2015-12-01

    Full Text Available This paper aims to investigate validity of “Export-led Growth Hypothesis” for Turkey using quarterly data in period from 2003:Q1 to 2015:Q1. Hypothesis argues that there is causality relationship from real export to real Gross Domestic Product (GDP. Johansen cointegration test, Gregory-Hansen cointegration test, Toda-Yamamoto causality test, Fully Modified Ordinary Least Squares (FMOLS, Canonical cointegrating regression (CCR and Dynamic ordinary least squares (DOLS methods were used in this study. Findings can be summarized as follows: a According to Johansen cointegration test there is no relationship among variables in the long-run whereas Gregory-Hansen cointegration test has determined relationship in the long-run; b According to Toda-Yamamoto causality test there is bidirectional causality between real export and real GDP. This finding proves the validity of “Export-led Growth Hypothesis” for Turkey; c According to FMOLS, CCR, DOLS methods a 1% increase in the real export increases the real GDP by 1.5195%, 1.5552%, 1.3171% respectively in the long-run. These methods prove the validity of “Export-led Growth Hypothesis” for Turkey.

  20. Development of a method for the characterization and operation of UV-LED for water treatment.

    Science.gov (United States)

    Kheyrandish, Ataollah; Mohseni, Madjid; Taghipour, Fariborz

    2017-10-01

    Tremendous improvements in semiconductor technology have made ultraviolet light-emitting diodes (UV-LEDs) a viable alternative to conventional UV sources for water treatment. A robust and validated experimental protocol for studying the kinetics of microorganism inactivation is key to the further development of UV-LEDs for water treatment. This study proposes a protocol to operate UV-LEDs and control their output as a polychromatic radiation source. In order to systematically develop this protocol, the results of spectral power distribution, radiation profile, and radiant power measurements of a variety of UV-LEDs are presented. A wide range of UV-LEDs was selected for this study, covering various UVA, UVB, and UVC wavelengths, viewing angles from 3.5° to 135°, and a variety of output powers. The effects of operational conditions and measurement techniques were investigated on these UV-LEDs using a specially designed and fabricated setup. Operating conditions, such as the UV-LED electrical current and solder temperature, were found to significantly affect the power and peak wavelength output. The measurement techniques and equipment, including the detector size, detector distance from the UV-LED, and potential reflection from the environment, were shown to influence the results for many of the UV-LEDs. The results obtained from these studies were analyzed and applied to the development of a protocol for UV-LED characterization. This protocol is presented as a guideline that allows the operation and control of UV-LEDs in any structure, as well as accurately measuring the UV-LED output. Such information is essential for performing a reliable UV-LED assessment for the inactivation of microorganisms and for obtaining precise kinetic data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Light out-coupling from LEDs by means of metal nanoparticles; Lichtauskopplung aus LEDs mittels Metallnanoteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Goehler, Tino

    2010-12-17

    The external quantum efficiency of light-emitting diodes (LEDs) based on Al- GaAs/InGaAlP is limited by total internal reflection because of the high refractive index (typically between 3 and 4) of the semiconductor. Metal nanoparticles (MNP) deposited on the surface of the LED can be used as dipole scatterers in order to enhance the emission of the LED. In this thesis, first, single gold nanoparticles of various sizes deposited on such an LED were investigated. A clear enhancement is detected as long as the dipole plasmon resonance of the particle is at a shorter wavelength than the LED emission. If the plasmon resonance coincides with the LED emission or is at a larger wavelength, the enhancement turns into suppression. Numerical simulations indicate that this latter effect is mainly caused by the particle quadrupole resonance producing extra absorption. Arrays of MNPs can be produced by a special mask technique called ''Fischer pattern nanolithography'' and manipulated in shape and size by additional steps. Originally, the MNPs produced by this technique are triangular in shape and turn out to suppress the LED emission. After transformation of the particles to spheres, a clear enhancement was detected. Light that would otherwise remain trapped inside the substrate is coupled out by resonant plasmonic scattering. Investigations on analogous structures on a transparent high-index material (GaP) indicate a stronger coupling between the particles than expected on the basis of literature data. (orig.)

  2. How Molecular Evolution Technologies can Provide Bespoke Industrial Enzymes: Application to Biofuels Comment les technologies d’évolution moléculaire peuvent fournir des enzymes industrielles sur mesure : application aux biocarburants

    Directory of Open Access Journals (Sweden)

    Fourage L.

    2013-08-01

    Full Text Available Enzymatic hydrolysis of lignocellulose is one of the major bottlenecks in the development of biological conversion of lignocellulosic biomass to biofuels. One of the most efficient organisms for the production of cellulolytic enzymes is the fungus Trichoderma reesei, mainly thanks to its high secretion capacity. The conversion of cellulose to glucose involves three types of cellulases working in synergy: endoglucanases (EC 3.2.1.4 randomly cleave 13-1,4 glycosidic linkages of cellulose, cellobiohydrolases (EC 3.2.1.91 attack cellulose chain ends to produce cellobiose dimers which are converted into glucose by the 13-glucosidases (EC 3.2.1 21. Unexpectedly, the amount of l3-glucosidase (BGLI from T. reesei hyperproducing strains represents a very low percentage of the total secreted proteins. A suboptimal content of this enzyme limits the performance of commercial cellulase preparations as cellobiose represents the main inhibitor of the cellulolysis reaction by cellobiohydrolases. This bottleneck can be alleviated either by overexpressing the f3-glucosidase in T. reesei or optimized its specific activity. After giving a brief overview of the main available technologies, this example will be used to illustrate the potential of directed evolution technologies to devolop enzymes tailored to fit industrial needs. We describe the L-ShuffiingTM strategy implemented with three parental genes originating from microbial biodiversity leading to identification of an efficient 13-glucosidase showing a 242 fold increase in specific activity for the pNPGIc substrate compared to WT (Wild Type Cel3a beta-glucosidase of T. reesei. After expression of the best improved 13-glucosidase in T. reesei and secretion of a new enzymatic cocktail, improvement of the glucosidase activity allows a 4-fold decrease of cellulase loading for the saccharification of an industrial pretreated biomass compared to the parental cocktail. L’hydrolyse enzymatique de la lignocellulose

  3. Buurtzorg: nurse-led community care.

    Science.gov (United States)

    Monsen, Karen A; de Blok, Jos

    2013-01-01

    Buurtzorg is a nurse-led, nurse-run organization of self-managed teams that provide home care to patients in their neighborhoods. Championing humanity over bureaucracy, autonomous teams work with primary care providers, community supports, and family resources to bring patients to optimal functioning as quickly as possible. The award-winning organization grew out of a common sense approach based on principles of trust, autonomy, creativity, simplicity, and collaboration. These organizational principles translate into highly effective and efficient care, satisfied patients, and enthusiastic nurses. The model is being replicated worldwide, with teams starting in Minnesota, Sweden, Japan, and other countries.

  4. Someone Has Led This Child To Believe

    OpenAIRE

    Louise, Regina

    2015-01-01

    ABSTRACTSOMEONE HAS LED THIS CHILD TO BELIEVE is a true story and continuation of the best-selling memoir Somebody’s Someone. After 12 year-old Regina Louise, tired of being beaten, battles and escapes an illegal guardian; she jumps from a two-story window and runs to a local police station where she is taken into custody, locked in a holding cell, and delivered to the Edgar Children’s Shelter, in Martinez California. Regina is closed off about her parents, her past…until she meets Jeanne Ke...

  5. Moral Issues in Intelligence-led Policing

    DEFF Research Database (Denmark)

    The core baseline of Intelligence-led Policing is the aim of increasing efficiency and quality of police work, with a focus on crime analysis and intelligence methods as tools for informed and objective decisions both when conducting targeted, specialized operations and when setting strategic...... priorities. This book critically addresses the proliferation of intelligence logics within policing from a wide array of scholarly perspectives. It considers questions such as: •How are precautionary logics becoming increasingly central in the dominant policing strategies? •What kind of challenges...... and the blurred and confrontational lines that can be observed between prevention, intelligence and investigation in police work....

  6. Fabrication of LED full-color display matrix with small pixel

    Science.gov (United States)

    Li, Jing; Xue, Bin; Yang, Hua; Liu, Lili; Xie, Haizhong; Pei, Yanrong; Lu, Pengzhi; Wang, Guohong; Wang, Junxi; Li, Jinmin

    2015-09-01

    With the development in material growth, device fabrication and packaging of LEDs, emission spectral of LED is able to cover the visible spectrum. In addition to the well-known lighting applications of LED, display is also one of the important applications of LED. In contrast with LCD, LEDs display has better contrast ratio, higher response rate, etc., which makes LEDs along with other self-illumination technologies an ideal candidate in making display panel. With the popularization of HD and Ultra HD standard, display panel with better image quality is needed. The number of pixels of the panel needs to be increased and the size of each pixel needs to be minimized. In this paper, we prepared a LED full-color display panel based on a 32×32 LED matrix with typical pixel size of 0.5mm. LED full-color display array with small pixel was obtained by mounting red LEDs, green LEDs and blue LEDs directly onto an isolating substrate such as sapphire . In addition, the substrate has metalized pads and connection before the matrix was connected to control unit. The control line and the column data line are prepared on the substrate, and there is an effective electrical insulation layers between them. The isolation layers consists of a SiO2 layer of 1000nm and polyimide layer of 3000nm. Polyimide as an important electrical insulating layer, we study some properties of it, such as :PI amination rate as a function of the curing temperature, PI resistivity as a function of the curing temperature and the punction electric field intensity of PI as a function of the film thickness of PI.

  7. Evolution of Business Models

    DEFF Research Database (Denmark)

    Antero, Michelle C.; Hedman, Jonas; Henningsson, Stefan

    2013-01-01

    The ERP industry has undergone dramatic changes over the past decades due to changing market demands, thereby creating new challenges and opportunities, which have to be managed by ERP vendors. This paper inquires into the necessary evolution of business models in a technology-intensive industry (e...

  8. Software Architecture Evolution

    Science.gov (United States)

    Barnes, Jeffrey M.

    2013-01-01

    Many software systems eventually undergo changes to their basic architectural structure. Such changes may be prompted by new feature requests, new quality attribute requirements, changing technology, or other reasons. Whatever the causes, architecture evolution is commonplace in real-world software projects. Today's software architects, however,…

  9. Cultural Evolution and SETI

    Science.gov (United States)

    Dick, S. J.

    2009-12-01

    The Drake Equation for the number of radio communicative technological civilizations in the Galaxy encompasses three components of cosmic evolution: astronomical, biological and cultural. Of these three, cultural evolution totally dominates in terms of the rapidity of its effects. Yet, SETI scientists do not take cultural evolution into account, perhaps for understandable reasons, since cultural evolution is not well-understood even on Earth and is unpredictable in its outcome. But the one certainty for technical civilizations billions, millions, or even thousands of years older than ours is that they will have undergone cultural evolution. Cultural evolution potentially takes place in many directions, but this paper argues that its central driving force is the maintenance, improvement and perpetuation of knowledge and intelligence, and that to the extent intelligence can be improved, it will be improved. Applying this principle to life in the universe, extraterrestrials will have sought the best way to improve their intelligence. One possibility is that they may have long ago advanced beyond flesh-and-blood to artificial intelligence, constituting a postbiological universe. Although this subject has been broached, it has not been given the attention it is due from its foundation in cultural evolution. Nor has the idea of a postbiological universe been carried to its logical conclusion, including a careful analysis of the implications for SETI. SETI scientists, social scientists, and experts in AI should consider the strengths and weaknesses of this new paradigm.

  10. UV LED lighting for automated crystal centring.

    Science.gov (United States)

    Chavas, Leonard M G; Yamada, Yusuke; Hiraki, Masahiko; Igarashi, Noriyuki; Matsugaki, Naohiro; Wakatsuki, Soichi

    2011-01-01

    A direct outcome of the exponential growth of macromolecular crystallography is the continuously increasing demand for synchrotron beam time, both from academic and industrial users. As more and more projects entail screening a profusion of sample crystals, fully automated procedures at every level of the experiments are being implemented at all synchrotron facilities. One of the major obstacles to achieving such automation lies in the sample recognition and centring in the X-ray beam. The capacity of UV light to specifically react with aromatic residues present in proteins or with DNA base pairs is at the basis of UV-assisted crystal centring. Although very efficient, a well known side effect of illuminating biological samples with strong UV sources is the damage induced on the irradiated samples. In the present study the effectiveness of a softer UV light for crystal centring by taking advantage of low-power light-emitting diode (LED) sources has been investigated. The use of UV LEDs represents a low-cost solution for crystal centring with high specificity.

  11. Studying Light Color using White LED Lighting

    Science.gov (United States)

    Yamagishi, Misako; Yamaba, Kazuo; Nagata, Manori; Kubo, Chiho; Nokura, Kunihiro

    Recently, white Light Emitting Diodes (LEDs) are receiving attention worldwide as new lighting devices. This study examined effects of a lighting application on performance using white LEDs. The light color—the correlated color temperature (CCT) —was assessed. It affected to psychological states and physiological conditions. Three CCT conditions were respectively set for the experiment: 2500 K, 5000 K, and 8200 K. In all, 20 younger subjects (20-30 years old), 15 middle-aged to elderly subjects (45-60 years old) and 12 elderly subjects (over 65 years-old) participated. They were presented a Numerical Verification (NV) task for performance measurement. The psychological states on performance were evaluated using the lighting assessment questionnaire. The physiological conditions were recorded using an electrocardiograph. Results show that the effects of CCT differ among age groups. Especially, the performance of younger subjects might differ from CCT conditions; elderly subjects are affected by CCT condition because of their visual acuity or response to contrast of objects.

  12. LED lighting increases the ecological impact of light pollution irrespective of color temperature.

    Science.gov (United States)

    Pawson, S M; Bader, M K-F

    Recognition of the extent and magnitude of night-time light pollution impacts on natural ecosystems is increasing, with pervasive effects observed in both nocturnal and diurnal species. Municipal and industrial lighting is on the cusp of a step change where energy-efficient lighting technology is driving a shift from “yellow” high-pressure sodium vapor lamps (HPS) to new “white” light-emitting diodes (LEDs). We hypothesized that white LEDs would be more attractive and thus have greater ecological impacts than HPS due to the peak UV-green-blue visual sensitivity of nocturnal invertebrates. Our results support this hypothesis; on average LED light traps captured 48% more insects than were captured with light traps fitted with HPS lamps, and this effect was dependent on air temperature (significant light × air temperature interaction). We found no evidence that manipulating the color temperature of white LEDs would minimize the ecological impacts of the adoption of white LED lights. As such, large-scale adoption of energy-efficient white LED lighting for municipal and industrial use may exacerbate ecological impacts and potentially amplify phytosanitary pest infestations. Our findings highlight the urgent need for collaborative research between ecologists and electrical engineers to ensure that future developments in LED technology minimize their potential ecological effects.

  13. Evolution in time-dependent fitness landscapes

    OpenAIRE

    Wilke, Claus O.

    1998-01-01

    Evolution in changing environments is an important, but little studied aspect of the theory of evolution. The idea of adaptive walks in fitness landscapes has triggered a vast amount of research and has led to many important insights about the progress of evolution. Nevertheless, the small step to time-dependent fitness landscapes has most of the time not been taken. In this work, some elements of a theory of adaptive walks on changing fitness landscapes are proposed, and are subsequently app...

  14. CHANGES OF SUPPLY CHAIN MANAGEMENT IN THE INFORMATION TECHNOLOGY INDUSTRY AS FUNCTION OF SUSTAINABLE DEVELOPMENT

    OpenAIRE

    Slobodan Acimovic; Dijana Krsic

    2014-01-01

    One of the world’s strongest industries – information technology (IT) industry, is constantly facing ever increasing need for change. A short life cycle of IT products and continuous investment in innovation (production, distribution, recycling) led to a significant evolution of supply chain management, where environmental issues are top priority.Through a completely new approach – high cooperation, partnerships, presence of many companies, more and more complex data and improved response tim...

  15. Are nurse-led chemotherapy clinics really nurse-led? An ethnographic study.

    Science.gov (United States)

    Farrell, Carole; Walshe, Catherine; Molassiotis, Alex

    2017-04-01

    The number of patients requiring ambulatory chemotherapy is increasing year on year, creating problems with capacity in outpatient clinics and chemotherapy units. Although nurse-led chemotherapy clinics have been set up to address this, there is a lack of evaluation of their effectiveness. Despite a rapid expansion in the development of nursing roles and responsibilities in oncology, there is little understanding of the operational aspects of nurses' roles in nurse-led clinics. To explore nurses' roles within nurse-led chemotherapy clinics. A focused ethnographic study of nurses' roles in nurse-led chemotherapy clinics, including semi-structured interviews with nurses. Four chemotherapy units/cancer centres in the UK PARTICIPANTS: Purposive sampling was used to select four cancer centres/units in different geographical areas within the UK operating nurse-led chemotherapy clinics. Participants were 13 nurses working within nurse-led chemotherapy clinics at the chosen locations. Non-participant observation of nurse-led chemotherapy clinics, semi-structured interviews with nurse participants, review of clinic protocols and associated documentation. 61 nurse-patient consultations were observed with 13 nurses; of these 13, interviews were conducted with 11 nurses. Despite similarities in clinical skills training and prescribing, there were great disparities between clinics run by chemotherapy nurses and those run by advanced nurse practitioners. This included the number of patients seen within each clinic, operational aspects, nurses' autonomy, scope of practice and clinical decision-making abilities. The differences highlighted four different levels of nurse-led chemotherapy clinics, based on nurses' autonomy and scope of clinical practice. However, this was heavily influenced by medical consultants. Several nurses perceived they were undertaking holistic assessments, however they were using medical models/consultation styles, indicating medicalization of nurses' roles

  16. Switched-capacitor isolated LED driver

    Science.gov (United States)

    Sanders, Seth R.; Kline, Mitchell

    2016-03-22

    A switched-capacitor voltage converter which is particularly well-suited for receiving a line voltage from which to drive current through a series of light emitting diodes (LEDs). Input voltage is rectified in a multi-level rectifier network having switched capacitors in an ascending-bank configuration for passing voltages in uniform steps between zero volts up to full received voltage V.sub.DC. A regulator section, operating on V.sub.DC, comprises switched-capacitor stages of H-bridge switching and flying capacitors. A current controlled oscillator drives the states of the switched-capacitor stages and changes its frequency to maintain a constant current to the load. Embodiments are described for isolating the load from the mains, utilizing an LC tank circuit or a multi-primary-winding transformer.

  17. Resident-Led Palliative Care Education Project.

    Science.gov (United States)

    Karlen, Naomi; Cruz, Brian; Leigh, A E

    2016-04-01

    Despite the growth of palliative medicine, 39% of hospitals do not have palliative care teams for consultation or to provide resident education. We examined the impact of resident-led education in palliative care principles on attitudes toward and comfort with palliative medicine and end-of-life care among internal medicine residents. An educational module designed by the authors was presented to other internal medicine residents in the program. Pre- and post-intervention survey data measuring residents' agreement with various statements regarding palliative medicine and end-of-life care were analyzed. Residents' agreement with various statements regarding palliative medicine and end-of-life care on a 5-point Likert scale was analyzed. Following the intervention, participants reported improved comfort with general knowledge of palliative medicine (p palliative care and end-of-life care (p curriculum in palliative medicine can improve resident comfort within this still-under-represented area of medicine.

  18. Directed self-assembly of mesoscopic components for led applications

    Science.gov (United States)

    Tkachenko, Anton

    Light-emitting diodes (LEDs) constitute a rapidly evolving and fast growing technology that promises to replace incandescent bulbs and compact fluorescent lights in many illumination applications. Large-area LED luminaires have a capability to transform lighting by providing a venue for development of smart lighting systems with additional benefits, such as visible light communications, sensing, health and productivity improvement through color temperature control, capability of creating "virtual sky" ceiling, and many others. The objective of this work is to explore directed self-assembly (DSA) approaches suitable for cost-effective assembly of large amount of LEDs and other mesoscopic (i.e. millimeter and sub-millimeter) electronic components and thus to enable manufacturing of smart lighting luminaires. Existing alternative approaches for assembly of semiconductor dies are examined including transfer printing, laser-assisted die transfer, and various directed self-assembly approaches using shape-recognition, magnetic and capillary forces, etc. After comparing their advantages and limitations, we developed two approaches to magnetic force-assisted DSA of LEDs on a large-area substrate in liquid and air medium. The first approach involves pick-up of buoyant and magnetic dies from the liquid surface onto the flexible substrate in a roll-to-roll process. The possibility of high-speed assembly of LED dies is demonstrated, but with a low yield due to the influence of the capillary force of the carrier liquid and the difficulty in ensuring reliable supply of dies to the assembly interface. To overcome the aforementioned challenges this process was modified to assemble the dies by sinking them onto the receiving substrate with a stencil mask on top, demonstrating LED assembly with a very low error rate but at a lower speed. A solder-assisted self-alignment is used to further improve placement precision and to ensure the proper orientation of the dies. The second

  19. Newly patented process enables low-cost solution for increasing white light spectrum of LEDs

    Science.gov (United States)

    Spanard, Jan-Marie

    2017-10-01

    A newly patented process for completing the spectral light array emitted by LED bulbs provides a low-cost method for producing better human centered lighting (HCL). This process uses non-luminescent colorant filters, filling out the jagged LED spectral emission into a full, white light array. While LED bulbs have the distinct economic advantages of using less energy, producing less heat and lasting years longer than traditional incandescent bulbs, the persistent metameric failure of LED bulbs has resulted in slower, and sometimes reluctant, adoption of LED lighting by the residential, retail and architectural markets. Adding missing wavelengths to LED generated bulbs via colorant filters increases the aesthetic appeal of the light by decreasing current levels of metameric failure, reducing the `flatness', `harshness', and `dullness' of LED generated light reported by consumers. LED phosphor-converted light can be successfully tuned to "whiter" white light with selective color filtering using permanent, durable transparent pigments. These transparent pigments are selectively applied in combination with existing manufacturing technologies and utilized as a final color-tuning step in bulb design. The quantity of emitted light chosen for color filtering can be adjusted from 1% to 100% of emitted light, creating a custom balance of light quantity with light quality. This invention recognizes that "better light" is frequently chosen over "more light" in the consumer marketplace.

  20. An Overview of LEDs' Effects on the Production of Bioactive Compounds and Crop Quality.

    Science.gov (United States)

    Hasan, Md Mohidul; Bashir, Tufail; Ghosh, Ritesh; Lee, Sun Keun; Bae, Hanhong

    2017-08-27

    Light-emitting diodes (LEDs) are characterized by their narrow-spectrum, non-thermal photon emission, greater longevity, and energy-saving characteristics, which are better than traditional light sources. LEDs thus hold the potential to revolutionize horticulture lighting technology for crop production, protection, and preservation. Exposure to different LED wavelengths can induce the synthesis of bioactive compounds and antioxidants, which in turn can improve the nutritional quality of horticultural crops. Similarly, LEDs increase the nutrient contents, reduce microbial contamination, and alter the ripening of postharvest fruits and vegetables. LED-treated agronomic products can be beneficial for human health due to their good nutrient value and high antioxidant properties. Besides that, the non-thermal properties of LEDs make them easy to use in closed-canopy or within-canopy lighting systems. Such configurations minimize electricity consumption by maintaining optimal incident photon fluxes. Interestingly, red, blue, and green LEDs can induce systemic acquired resistance in various plant species against fungal pathogens. Hence, when seasonal clouds restrict sunlight, LEDs can provide a controllable, alternative source of selected single or mixed wavelength photon source in greenhouse conditions.

  1. Construction of an array of LEDs coupled to a concentrator for phototherapy

    Science.gov (United States)

    Almeida, Joana; Liang, Dawei

    2011-07-01

    The use of LED devices for phototherapy has been expanding in the last decade. This technology provides a safer emission spectrum in large target tissue areas when compared to laser emissions. For enhancing the phototherapeutic effects of red light emitted by LEDs, a simple optical concentrator capable of efficient light concentration and homogenization was developed. The LEDs wavelength of 660 nm is coincident with an absorption peak of the mitochondrial photoreceptor molecule cytochrome c oxidase. The prototype was optimized by non-sequential ray-tracing software ZEMAX, attaining both excellent light uniformity and 50mW/cm2 irradiance at the concentrator output end. Heat emanated from the LEDs source is effectively dissipated by the side walls of the concentrator, ensuring a nearly constant temperature environment for tissue treatment. The prototype was tested on cutaneous hyperpigmented marks caused by cupping in two healthy volunteers. Marks were irradiated by LEDs radiations with or without the use of concentrator respectively. Equal exposure durations and light fluences were tested. The use of the concentrator-coupled LEDs source revealed an activation of blood movement immediately after LEDs exposure, an effect not attainable by the LEDs source without the concentrator even at extended exposure time. Promising futures for the treatment of inflammation, tissue repair and skin rejuvenation could be expected by adopting this simple technique.

  2. Assessment of lumen degradation and remaining useful life of LEDs using particle filter

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep [Auburn Univ., AL (United States); Zhang, Hao [Auburn Univ., AL (United States); Davis, Lynn [Auburn Univ., AL (United States)

    2013-07-16

    With the development of light-emitting diode (LED) technology, light emitting diodes system is becoming a popular light source in daily life and industry area. It has shown that Led from same factory and work under same working condition, may have significantly different behavior. Therefore, it is very important to learn the fail mechanisms, especially in the case of safety critical and harsh environment application. This paper focus on a prognostic health management (PHM) method based on the measurement of forward voltage and forward current of bare LED under harsh environment. In this paper, experiment has been done with ten samples. Ten pristine bare LEDs have been tested at 85°C while simultaneously being subjected to 85% humid environment. Pulse width modulation (PWM) control method has been employed to drive the bare LED in order to reduce the heat effect caused by forward current and high frequency (300HZ) data acquisition has been used to measure the peak forward voltage and forward current. Test to failure (lumen drops to 70 percent) data has been measured to study the effects of high temperature and humid environment loadings on the bare LED. Also, solid state cooling method with peltier cooler has been used to control the temperature of LED in the integrating sphere when take the measurement of lumen flux. The shift of forward voltage forward current curve and lumen degradation has been recorded to help build the fail model and predicted the remaining useful life. In this method, particle filter has been employed to predict the remaining useful life (RUL) of the bare LED and give us a whole picture how Led system fails. Result shows that predication of remaining useful life of Led, made by the particle filter model works under reasonable limit, and hence this method can be employed to predict the failure of Led caused by thermal and humid stress under harsh environment.

  3. Using UAVs to Conduct Student-led Research Projects

    Science.gov (United States)

    Olds, S. E.; Lewis, P. M., Jr.

    2016-12-01

    Recreational drones can inspire students to initiate research projects. These "toys" have a low cost (design skills such as designing a camera mount to obtain nadir or oblique imagery. Learners can also move to more sophisticated research using photogrammetric skills such as taking overlapping photographs to create 3D structure from motion (SfM) models. To encourage the use of onboard sensors, the team worked with an engineer to build a 33-gram prototype environmental logger called SABEL (Shelley [Olds] and Bob [Ellis]'s Environmental Logger). Assembled on an Arduino board, SABEL collects temperature, humidity, and GPS position. This presentation will provide examples of student-led investigations, instructions for building the SABEL sensor package, and the status of the new e-book compilation of student-focused activities using recreational drones to pursue science, math, engineering, and technology research investigations.

  4. A customer-insight led approach to building operational resilience.

    Science.gov (United States)

    Passey, Fi

    2018-01-01

    High-profile failures over the past few years have led to the disruption of banking services in the UK, with some banks' customers left unable to make or receive payments, check balances or access cash for days or weeks. Technological advances and a push towards remote channels have increased customer expectations of 'always on' - any time, any place, anywhere - and with disruptions lasting anything from a few minutes to nearly a month, the regulator is also taking an interest. Nationwide Building Society has responded positively to this challenge by defining its operational resilience strategy, a long-term plan aimed at minimising the likelihood and impact of future disruptions. Customer research was used in order to understand customer expectations, as well as define and prioritise its end-to-end customer journeys, known as business service lines. A comprehensive mapping exercise facilitated the development of strategies and investment projects to address identified vulnerabilities and increase resilience.

  5. LED Lightbulbs as a Source of Electricity Saving in Buildings

    Directory of Open Access Journals (Sweden)

    Zeb Akhtar

    2016-01-01

    Full Text Available Today a number of renewable energy technologies are available for power generation, but fossil fuels are still providing a dominant share nevertheless. In order to decrease the electric bill and save our environment, energy conservation is always crucial. In this paper a very interesting idea is presented which is economically viable to reduce electricity usage in our buildings. An effort has been made to estimate the amount of energy that could be saved in the dormitory section of the IMOP building in Russia. Although there are many ways to reduce the consumption of electricity in this building but here the emphasis is on changing light bulbs inside the rooms, kitchen, toilet and bathroom of each apartment. The scope of the study is to figure out monthly electricity saving by replacing traditional light bulbs by LED light bulbs in the building under consideration. The total investment required and the payback period is also presented.

  6. 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.

  7. 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

  8. 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.

  9. Arresting Evolution.

    Science.gov (United States)

    Bull, James J; Barrick, Jeffrey E

    2017-12-01

    Evolution in the form of selective breeding has long been harnessed as a useful tool by humans. However, rapid evolution can also be a danger to our health and a stumbling block for biotechnology. Unwanted evolution can underlie the emergence of drug and pesticide resistance, cancer, and weeds. It makes live vaccines and engineered cells inherently unreliable and unpredictable, and therefore potentially unsafe. Yet, there are strategies that have been and can possibly be used to stop or slow many types of evolution. We review and classify existing population genetics-inspired methods for arresting evolution. Then, we discuss how genome editing techniques enable a radically new set of approaches to limit evolution. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. INTERACTIVE 3D SYSTEMS OF VIRTUAL REALITY AS ONE OF THE DIRECTIONS FOR EVOLUTION OF DISTANCE LEARNING TECHNOLOGIES IN HIGHER SCOOL

    Directory of Open Access Journals (Sweden)

    Д В Сенашенко

    2016-12-01

    Full Text Available The article describes history of 3D virtual interactive technology developing and gives story of it’s using for different business companies and universities. Statistical analysis of target audience is provided. Features of such systems are described. Particularly author mentions functionality and advantages of 3D-systmes as one of long-term distant learning technology during educational program realization and formulates arguments for introduction of this technology to distant education systems of Russian Higher school. Discusses usability of it for distance learning in high school.

  11. GATEWAY Demonstrations: LED System Performance in a Trial Installation--Two Years Later, Yuma Border Patrol, Yuma, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Andrea M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sullivan, Gregory P. [Efficiency Solutions, Inc., Richland, WA (United States); Davis, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-04-01

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial demonstration in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations at the Yuma Sector Border Patrol Area in Yuma, Arizona. The retrofit was documented to better understand LED technology performance in high-temperature environments. This report follows the GATEWAY Yuma Phase 1.1 Report and reflects LED system results documented two years after the demonstration began.

  12. GATEWAY Demonstrations: LED System Performance in a Trial Installation--One Year Later, Yuma Border Patrol, Yuma, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, A. M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Davis, R. G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-01

    Along the Yuma Sector Border Patrol Area in Yuma, Arizona, the GATEWAY program conducted a trial demonstration in which the incumbent quartz metal halide area lighting was replaced with LED at three pole locations at the Yuma Sector Border Patrol Area in Yuma, Arizona. The retrofit was documented to better understand LED technology performance in high-temperature environments. This report follows the GATEWAY Yuma Phase 1.0 Report and reflects LED system results documented one year after the demonstration began.

  13. Public outreach: (R)evolution by the lakeside

    CERN Multimedia

    2006-01-01

    Why do the planets revolve around the Sun? Has genetic science shaken Darwin's theories to their foundations? Are viruses the champions of evolution? Is progress a form of tradition? On 8 and 9 July, Geneva's Science History Museum is inviting you to a Science Night on the theme of 'Evolution, revolution'. The Sixth Science Night will host some 60 stands and offer workshops for children, guided tours, exhibitions and shows. Anticipating the (r)evolutions from the LHC, CERN will also be taking part in the event. The future accelerator promises to deliver scientific advances and may even turn our understanding of the infinitesimally small on its head. However, the LHC has already led to technological breakthroughs. The Laboratory's stand will put a special emphasis on the part played by CERN in the computing revolution, from the Web to the Computing Grid. Computer animations will be used to explain these technologies which have spin-offs well beyond the field of particle physics that are of benefit to the whol...

  14. United States Air Force Computer-Aided Acquisition and Logistics Support (CALS) Evolution of Computer Integrated Manufacturing (CIM) Technologies. Version 2.0 Draft

    Science.gov (United States)

    1988-11-01

    During the past decade a great deal of effort has been focused on the advantages computerization can bring to engineering design and production activities. This is seen in such developments as Group Technology (GT), Manufacturing Resource Planning (M...

  15. The Making of the Indian National Innovation Systems: Lessons on the specific characteristics of the domestic and the external co-evolutions of technologies, institutions and incentives

    DEFF Research Database (Denmark)

    Muchie, Mammo; Baskaran, Angathevar

    is growing at a nearly 8 % of GDP and is seen as an emerging economy on a par with China. The policy makers in India have asked: can India become a developed country by 2020? (see Kalam, 1998).  India has tried to apply science and technology to industrialise agriculture and build a modern economy...... system of innovation has borne always a dualistic and lopsided feature in terms of priorities for science and technology selection and foresight, policies for supporting science, technology and innovation, creating institutions and their linkages, knowledge and learning, capability and training......, diffusion and incentives. Despite its significant achievements in areas such as building strong industrial and R & D base, establishing a large number of science and technology institutions, and creating large pool of scientists and engineers, the Indian national innovation system has been criticised...

  16. Green technology in Taiwan

    International Nuclear Information System (INIS)

    Runderkamp, D.

    2010-01-01

    Taiwan is striving for leadership in the field of green Technologies. Solar cells and Light Emitting Diodes (LED) are the best examples of successful Taiwanese green technologies. Electronic vehicles and smart grids are giving new impetus to the Taiwanese export of high-quality technology. [nl

  17. Key issues review: evolution on rugged adaptive landscapes

    Science.gov (United States)

    Obolski, Uri; Ram, Yoav; Hadany, Lilach

    2018-01-01

    Adaptive landscapes represent a mapping between genotype and fitness. Rugged adaptive landscapes contain two or more adaptive peaks: allele combinations with higher fitness than any of their neighbors in the genetic space. How do populations evolve on such rugged landscapes? Evolutionary biologists have struggled with this question since it was first introduced in the 1930s by Sewall Wright. Discoveries in the fields of genetics and biochemistry inspired various mathematical models of adaptive landscapes. The development of landscape models led to numerous theoretical studies analyzing evolution on rugged landscapes under different biological conditions. The large body of theoretical work suggests that adaptive landscapes are major determinants of the progress and outcome of evolutionary processes. Recent technological advances in molecular biology and microbiology allow experimenters to measure adaptive values of large sets of allele combinations and construct empirical adaptive landscapes for the first time. Such empirical landscapes have already been generated in bacteria, yeast, viruses, and fungi, and are contributing to new insights about evolution on adaptive landscapes. In this Key Issues Review we will: (i) introduce the concept of adaptive landscapes; (ii) review the major theoretical studies of evolution on rugged landscapes; (iii) review some of the recently obtained empirical adaptive landscapes; (iv) discuss recent mathematical and statistical analyses motivated by empirical adaptive landscapes, as well as provide the reader with instructions and source code to implement simulations of evolution on adaptive landscapes; and (v) discuss possible future directions for this exciting field.

  18. The Quest for the FFA and Where It Led.

    Science.gov (United States)

    Kanwisher, Nancy

    2017-02-01

    This article tells the story behind our first paper on the fusiform face area (FFA): how we chose the question, developed the methods, and followed the data to find the FFA and subsequently many other functionally specialized cortical regions. The paper's impact had less to do with the particular findings in the paper itself and more to do with the method that it promoted and the picture of the human mind and brain that it led to. The use of a functional localizer to define a candidate region in each subject individually enabled us not just to make pictures of brain activation, but also to ask principled, hypothesis-driven questions about a thing in nature. This method enabled stronger and more extensive tests of the function of each cortical region than had been possible before in humans and, as a result, has produced a large body of evidence that the human cortex contains numerous regions that are specifically engaged in particular mental processes. The growing inventory of cortical regions with distinctive and often very specific functions can be seen as an initial sketch of the basic components of the human mind. This sketch also serves as a roadmap into the vast and exciting new landscape of questions about the computations, structural connections, time course, development, plasticity, and evolution of each of these regions, as well as the hardest question of all: how do these regions work together to produce human intelligence? Copyright © 2017 the authors 0270-6474/17/371056-06$15.00/0.

  19. Baby-led Weaning: A Preliminary Investigation.

    Science.gov (United States)

    D'Andrea, Elisa; Jenkins, Kielyn; Mathews, Maria; Roebothan, Barbara

    2016-06-01

    To date, baby-led weaning (BLW) has not been examined in a Canadian population. This research investigated common BLW practices and compared associated knowledge and perceptions of practicing mothers and health care professionals (HCPs). Sixty-five mothers practicing BLW and 33 HCPs were surveyed using 2 online questionnaires. Mothers were recruited through the Newfoundland and Labrador BLW Facebook page and HCPs via email at 2 regional health authorities. Mothers described BLW in terms of food shape and consistency (whole, solid); however, in practice, some mothers offered puréed foods such as infant cereals. More HCPs than mothers indicated choking, inadequate energy, and iron intake as concerns. Mothers relied on the Facebook page over HCPs for BLW information and support. Although all practicing mothers would recommend BLW to others, less than half (48.5%) of HCPs would support it in their practice. Mothers following BLW vary greatly in their experiences and adherence to BLW. They view the practice and its disadvantages very differently than HCPs. Although most HCPs were aware of BLW, few were familiar with specific practices. HCPs may benefit from a greater understanding of BLW to provide guidance to the growing number of mothers following this practice.

  20. Led Astray by Hemoglobin A1c

    Directory of Open Access Journals (Sweden)

    Jean Chen MD

    2016-01-01

    Full Text Available Hemoglobin A1c (A1c is used frequently to diagnose and treat diabetes mellitus. Therefore, it is important be aware of factors that may interfere with the accuracy of A1c measurements. This is a case of a rare hemoglobin variant that falsely elevated a nondiabetic patient’s A1c level and led to a misdiagnosis of diabetes. A 67-year-old male presented to endocrine clinic for further management after he was diagnosed with diabetes based on an elevated A1c of 10.7%, which is approximately equivalent to an average blood glucose of 260 mg/dL. Multiple repeat A1c levels remained >10%, but his home fasting and random glucose monitoring ranged from 92 to 130 mg/dL. Hemoglobin electrophoresis and subsequent genetic analysis diagnosed the patient with hemoglobin Wayne, a rare hemoglobin variant. This variant falsely elevates A1c levels when A1c is measured using cation-exchange high-performance liquid chromatography. When the boronate affinity method was applied instead, the patient’s A1c level was actually 4.7%. Though hemoglobin Wayne is clinically silent, this patient was erroneously diagnosed with diabetes and started on an antiglycemic medication. Due to this misdiagnosis, the patient was at risk of escalation in his “diabetes management” and hypoglycemia. Therefore, it is important that providers are aware of factors that may result in hemoglobin A1c inaccuracy including hemoglobin variants.

  1. Assessing the colour quality of LED sources

    DEFF Research Database (Denmark)

    Jost-Boissard, S.; Avouac, P.; Fontoynont, Marc

    2015-01-01

    The CIE General Colour Rendering Index is currently the criterion used to describe and measure the colour-rendering properties of light sources. But over the past years, there has been increasing evidence of its limitations particularly its ability to predict the perceived colour quality of light...... but also with a preference index or a memory index calculated without blue and purple hues. A very low correlation was found between appreciation and naturalness indicating that colour quality needs more than one metric to describe subjective aspects.......The CIE General Colour Rendering Index is currently the criterion used to describe and measure the colour-rendering properties of light sources. But over the past years, there has been increasing evidence of its limitations particularly its ability to predict the perceived colour quality of light...... sources and especially some LEDs. In this paper, several aspects of perceived colour quality are investigated using a side-by-side paired comparison method, and the following criteria: naturalness of fruits and vegetables, colourfulness of the Macbeth Color Checker chart, visual appreciation...

  2. Blue LED irradiation to hydration of skin

    Science.gov (United States)

    Menezes, Priscila F. C.; Requena, Michelle B.; Lizarelli, Rosane F., Z.; Bagnato, Vanderlei S.

    2015-06-01

    Blue LED system irradiation shows many important properties on skin as: bacterial decontamination, degradation of endogenous skin chromophores and biostimulation. In this clinical study we prove that the blue light improves the skin hydration. In the literature none authors reports this biological property on skin. Then this study aims to discuss the role of blue light in the skin hydration. Twenty patients were selected to this study with age between 25-35 years old and phototype I, II and III. A defined area from forearm was pre determined (A = 4.0 cm2). The study was randomized in two treatment groups using one blue light device (power of 5.3mW and irradiance of 10.8mW/cm2). The first treatment group was irradiated with 3J/cm2 (277seconds) and the second with 6J/cm2 (555 seconds). The skin hydration evaluations were done using a corneometer. The measurements were collected in 7, 14, 21 and 30 days, during the treatment. Statistical test of ANOVA, Tukey and T-Student were applied considering 5% of significance. In conclusion, both doses were able to improve the skin hydration; however, 6J/cm2 has kept this hydration for 30 days.

  3. Teaching Evolution

    Science.gov (United States)

    Bryner, Jeanna

    2005-01-01

    Eighty years after the famous 1925 Scopes "monkey trial," which tested a teacher's right to discuss the theory of evolution in the classroom, evolution--and its most recent counterview, called "intelligent design"--are in the headlines again, and just about everyone seems to have an opinion. This past July, President Bush weighed in, telling…

  4. A large-area, LED-based spectral response measurement system for solar PV device characterization

    Science.gov (United States)

    Hamadani, Behrang; Roller, John; Yoon, Howard; Dougherty, Brian

    2012-02-01

    Accurate and reliable measurement of the spectral responsivity (SR) of a solar cell is an important step in evaluating the electrical performance of competing photovoltaic (PV) technologies. We have investigated ways to measure the spectral responsivity, and hence the external quantum efficiency, of solar cells using measurement techniques that employ light emitting diodes (LEDs). Our setup includes one or more plates of compactly-installed, high-powered LEDs each containing up to 32 different LEDs that span the wavelength range of 375 nm to 1200 nm. Each LED plate is placed at the entrance of a tapered, highly reflective light guide for light mixing and large-area projection. Two unique measurement techniques have been investigated at NIST. The first technique consists of an LED sweep algorithm where a pulsed signal is applied to a given LED and the photogenerated current from the device under test is recorded using a lock-in technique. In the second SR technique, 32 variable-frequency, pulsed signals are applied to all LEDs at the same time, while recording the photogenerated current by a spectrum analyzer in the frequency domain. We will describe the uniqueness and advantages offered by each technique in detail and compare the accuracy of the two methods. A scheme for providing light bias and its impact on the SR measurements will be reported.

  5. Ethics, evolution and culture.

    Science.gov (United States)

    Mesoudi, Alex; Danielson, Peter

    2008-08-01

    Recent work in the fields of evolutionary ethics and moral psychology appears to be converging on a single empirically- and evolutionary-based science of morality or ethics. To date, however, these fields have failed to provide an adequate conceptualisation of how culture affects the content and distribution of moral norms. This is particularly important for a large class of moral norms relating to rapidly changing technological or social environments, such as norms regarding the acceptability of genetically modified organisms. Here we suggest that a science of morality/ethics can benefit from adopting a cultural evolution or gene-culture coevolution approach, which treats culture as a second, separate evolutionary system that acts in parallel to biological/genetic evolution. This cultural evolution approach brings with it a set of established theoretical concepts (e.g. different cultural transmission mechanisms) and empirical methods (e.g. evolutionary game theory) that can significantly improve our understanding of human morality.

  6. Student-Led Engagement of Journal Article Authors in the Classroom Using Web-Based Videoconferencing

    Science.gov (United States)

    Stockman, Brian J.

    2015-01-01

    The learning environment described here uses Web-based videoconferencing technology to merge the traditional classroom journal article discussion with student-led interviews of journal article authors. Papers that describe recent applications of a given technique are selected, with the author engagement occurring at the end of a three or four week…

  7. Connections beyond the margins of the power grid Information technology and the evolution of off-grid solar electricity in the developing world

    Science.gov (United States)

    Alstone, Peter Michael

    This work explores the intersections of information technology and off-grid electricity deployment in the developing world with focus on a key instance: the emergence of pay-as-you-go (PAYG) solar household-scale energy systems. It is grounded in detailed field study by my research team in Kenya between 2013-2014 that included primary data collection across the solar supply chain from global businesses through national and local distribution and to the end-users. We supplement the information with business process and national survey data to develop a detailed view of the markets, technology systems, and individuals who interact within those frameworks. The findings are presented in this dissertation as a series of four chapters with introductory, bridging, and synthesis material between them. The first chapter, Decentralized Energy Systems for Clean Electricity Access, presents a global view of the emerging off-grid power sector. Long-run trends in technology create "a unique moment in history" for closing the gap between global population and access to electricity, which has stubbornly held at 1-2 billion people without power since the initiation of the electric utility business model in the late 1800's. We show the potential for widespread near-term adoption of off-grid solar, which could lead to ten times less inequality in access and also ten times lower household-level climate impacts. Decentralized power systems that replace fuel-based incumbent lighting can advance the causes of climate stabilization, economic and social freedom and human health. Chapters two and three are focused on market and institutional dynamics present circa 2014 in for off-grid solar with a focus on the Kenya market. Chapter 2, "Off-grid Power and Connectivity", presents our findings related to the widespread influence of information technology across the supply chain for solar and in PAYG approaches. Using digital financing and embedded payment verification technology, PAYG

  8. Peer-led prenatal breast-feeding education: a viable alternative to nurse-led education.

    Science.gov (United States)

    Rempel, Lynn A; Moore, Katrina C J

    2012-02-01

    To evaluate a prenatal breast-feeding class developed and facilitated by peer Breast-feeding Buddies. Non-equivalent control group quasi-experimental study comparing participants of the peer-led class (PLC) to those attending an established hospital-based breast-feeding nurse-led class (NLC). A brief questionnaire was completed immediately prior to the class, and telephone interviews were conducted approximately one week following the class, and one and six months post partum. 54 expectant mothers who registered for the community PLC and 55 expectant mothers who registered for the NLC. Breast-feeding intentions were measured at all time-points. Class evaluations, breast-feeding experiences, and breast-feeding support were measured at all post-class interviews. Both classes were considered worthwhile, but the PLC class was rated as more helpful and participants appreciated learning from the peers' personal experiences. Mothers taught by peers were more likely to access peer breast-feeding support. PLC participants initially decreased their prenatal breast-feeding duration intentions but had significantly stronger intentions to continue breast feeding at six months than did NLC mothers. A peer-led prenatal breast-feeding class is as effective as a traditional model of breast-feeding education and is a valuable tool to promote and support successful breast feeding. RECOMMENDATIONS FOR PRACTICE: Peer-led breast-feeding classes should be provided to enhance the accessibility of breast-feeding education and support for expectant mothers. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Is Nigerian Growth Trade-Led?

    Directory of Open Access Journals (Sweden)

    Ismail Adigun Olayemi

    2017-09-01

    Full Text Available Purpose: Nigeria is currently in recession, a situation described as induced by decreases in oil output and export, caused by the bombings of oil pipelines in its Niger Delta region, and the unanticipated decline in its value of exports and currency, resulting from the decline in oil prices. With the export value decline, somersaulting to growth, could it then be that Nigerian economic growth is trade constrained? How important is export to growth?. This study investigates these, its invention balances in its methodology. Design/methodology/approach: To achieve the above, this paper employs the Autoregressive Distributed Lag Model (ARDL and the Thirlwall's Law of balance of payment led growth, using a combination of annual (1981–2016 and quarterly (2000Q1–2016Q4 data to ensure robustness. This combination not only allows for comparison but also ensures the reflection of the current government's trade decisions and trade activities; these are missing in other studies. Findings: Using the Wald F-Statistic, Economic growth is found to be equal to export growth rate divided by income elasticity of import, the estimated income elasticity of import which is greater than 100% or elastic reflects over dependence on import both in the short and long run, implying that Nigeria imports more than it earns. Exchange rate and terms of trade are insignificant especially in the long run. The study calls for monitoring of import contents; the government needs to enforce its recent directives to stop importation of some products that are already being produced within with higher quality and adequate export promotion strategies should be formulated and enforced. Research limitations/implications: The data span is restricted by data availability, the study could as well confirm its results with monthly data for robustness and better confidence, but most of the variables are reported annually and quarterly only. Originality/value: Many studies have confirmed the

  10. Stellar evolution

    CERN Document Server

    Meadows, A J

    2013-01-01

    Stellar Evolution, Second Edition covers the significant advances in the understanding of birth, life, and death of stars.This book is divided into nine chapters and begins with a description of the characteristics of stars according to their brightness, distance, size, mass, age, and chemical composition. The next chapters deal with the families, structure, and birth of stars. These topics are followed by discussions of the chemical composition and the evolution of main-sequence stars. A chapter focuses on the unique features of the sun as a star, including its evolution, magnetic fields, act

  11. Evolution of clustered storage

    CERN Multimedia

    CERN. Geneva; Van de Vyvre, Pierre

    2007-01-01

    The session actually featured two presentations: * Evolution of clustered storage by Lance Hukill, Quantum Corporation * ALICE DAQ - Usage of a Cluster-File System: Quantum StorNext by Pierre Vande Vyvre, CERN-PH the second one prepared at short notice by Pierre (thanks!) to present how the Quantum technologies are being used in the ALICE experiment. The abstract to Mr Hukill's follows. Clustered Storage is a technology that is driven by business and mission applications. The evolution of Clustered Storage solutions starts first at the alignment between End-users needs and Industry trends: * Push-and-Pull between managing for today versus planning for tomorrow * Breaking down the real business problems to the core applications * Commoditization of clients, servers, and target devices * Interchangeability, Interoperability, Remote Access, Centralized control * Oh, and yes, there is a budget and the "real world" to deal with This presentation will talk through these needs and trends, and then ask the question, ...

  12. Painting Education & Artistic Evolution

    OpenAIRE

    Tandirli, Emre

    2012-01-01

    Art is the most effective way of expressing human emotions. It should also be an excellent application of traditional or technological tools. In our presentation-research we will be focusing on painting, painting education and advanced artistic evolution process in terms of traditional application domains. An immortal painting-masterpiece should be the competent example of an excellent composition and also a perfect example of application. Preparation of painting tubes, choice of pertinent an...

  13. [Analysis of color gamut of LCD system based on LED backlight with area-controlling technique].

    Science.gov (United States)

    Li, Fu-Wen; Jin, Wei-Qi; Shao, Xi-Bin; Zhang, Li-Lei; Wan, Li-Fang

    2010-05-01

    Color gamut as a significant performance index for display system describes the color reproduction ability IN real scenes. Liquid crystal display (LCD) is the most popular technology in flat panel display. However, conventional cold cathode fluorescent lamp (CCFL) backlight of LCD can not behave high color gamut compared with cathode ray tube (CRT). The common used method of color gamut measuring for LCD system is introduced at the beginning. According to the inner structure and display principle of LCD system, there are three major factors deciding LCD's color gamut: spectral properties of backlight, transmittance properties of color filters and performance of liquid crystal panel. Instead of conventional backlight CCFL, RGB-LED backlight is used for improving color reproduction of LCD display system. Due to the imperfect match between RGB-LED' s spectra and color filter's transmittance, the color filter would reduce the color gamut of LCD system more or less. Therefore, LCD system based on LED backlight with area-control technique is introduced which modifies backlight control signal according to the input signal After analyzing and calculating the spectra of LED backlight which passes through the color filters using method of colorimetry, the area sizes of color gamut triangles of RGB-LED backlight with area-control and RGB-LED backlight without area-control LCD systems are compared and the relationship between color gamut and varying contrast of liquid crystal panel is analyzed. It is indicated that LED backlight with area-control technique can avoid color saturation dropping and have little effects on the contrast variation of liquid crystal panel. In other words, LED backlight with area-control technique relaxes the requirements of both color filter performance and liquid crystal panel. Thus, it is of importance to improve the color gamut of the current LCD system with area-control LED backlight.

  14. Transcranial LED therapy for cognitive dysfunction in chronic, mild traumatic brain injury: two case reports

    Science.gov (United States)

    Naeser, Margaret A.; Saltmarche, Anita; Krengel, Maxine H.; Hamblin, Michael R.; Knight, Jeffrey A.

    2010-02-01

    Two chronic, traumatic brain injury (TBI) cases are presented, where cognitive function improved following treatment with transcranial light emitting diodes (LEDs). At age 59, P1 had closed-head injury from a motor vehicle accident (MVA) without loss of consciousness and normal MRI, but unable to return to work as development specialist in internet marketing, due to cognitive dysfunction. At 7 years post-MVA, she began transcranial LED treatments with cluster heads (2.1" diameter with 61 diodes each - 9x633nm, 52x870nm; 12-15mW per diode; total power, 500mW; 22.2 mW/cm2) on bilateral frontal, temporal, parietal, occipital and midline sagittal areas (13.3 J/cm2 at scalp, estimated 0.4 J/cm2 to brain cortex per area). Prior to transcranial LED, focused time on computer was 20 minutes. After 2 months of weekly, transcranial LED treatments, increased to 3 hours on computer. Performs nightly home treatments (now, 5 years, age 72); if stops treating >2 weeks, regresses. P2 (age 52F) had history of closed-head injuries related to sports/military training and recent fall. MRI shows fronto-parietal cortical atrophy. Pre-LED, was not able to work for 6 months and scored below average on attention, memory and executive function. Performed nightly transcranial LED treatments at home (9 months) with similar LED device, on frontal and parietal areas. After 4 months of LED treatments, returned to work as executive consultant, international technology consulting firm. Neuropsychological testing (post- 9 months of transcranial LED) showed significant improvement in memory and executive functioning (range, +1 to +2 SD improvement). Case 2 reported reduction in PTSD symptoms.

  15. Schumpeter's Evolution

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    This draft of a book on Schumpeter is distributed for commenting. It is a stylised intellectual biography that focus on the emergence and extension of the Schumpeterian vision and analysis of economic and social evolution. The draft provides novel interpretations of Schumpeter's six major books. He...... originally developed his evolutionary research programme in Wesen from 1908 by studying the inherent limitations of Neoclassical Economics. He presented core results on economic evolution and sketched an extension evolutionary analysis to all social sciences in Entwicklung from 1912. He made a partial...... reworking of his basic theory of economic evolution in Development from 1934, and this reworking was continued in Cycles from 1939. Here Schumpeter also tried to handle the statistical and historical evidence on the waveform evolution of the capitalist economy. Capitalism from 1942 modified the model...

  16. The personalisation of a learning environment: student-led connections online and offline

    OpenAIRE

    Davis, Hugh; White, Su

    2011-01-01

    Rapidly evolving technological change is necessarily accompanied by matched evolution of individual practice amongst users. In a connected world, the users are universal, and students entering universities may arrive with a mix of sophisticated and naïve approaches to using technology to support their learning. The University of Southampton has designed and is implementing a holistic learning environment radically different from the VLEs which have gained widespread usage since the late 1990s...

  17. Modelling intelligence-led policing to identify its potential

    NARCIS (Netherlands)

    Hengst-Bruggeling, M. den; Graaf, H.A.L.M. de; Scheepstal, P.G.M. van

    2014-01-01

    lntelligence-led policing is a concept of policing that has been applied throughout the world. Despite some encouraging reports, the effect of intelligence-led policing is largely unknown. This paper presents a method with which it is possible to identify intelligence-led policing's potential to

  18. Luminaries-level structure improvement of LEDs for heat dissipation ...

    Indian Academy of Sciences (India)

    Heat dissipation enhancement of LED luminaries is of great significance to the large-scale application of LED. Luminaries-level structure improvement by the method of boring through-hole is adopted to intensify heat dissipation. Furthermore, the natural convection heat transfer process of LED luminaries is simulated by ...

  19. EC-LEDS Supports the Low-Carbon Transition

    Energy Technology Data Exchange (ETDEWEB)

    2016-09-01

    EC-LEDS is a flagship U.S. government-led effort that assists countries to create and implement low emission development strategies, or LEDS -- development frameworks that promote sustainable social and economic development while reducing greenhouse gas emissions over the medium to long term.

  20. Thermal design for the high-power LED lamp

    International Nuclear Information System (INIS)

    Tian Xiaogai; Chen Wei; Zhang Jiyong

    2011-01-01

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

  1. Mapping Student-Led Peer Learning in the UK

    Science.gov (United States)

    Keenan, Chris

    2014-01-01

    Peer-led academic learning has increased in importance, but there is little sense of how many institutions support it, how they understand its purposes or what peer-led learning best practice is. This report examines the provision of peer-led learning in the UK. It identifies challenges and opportunities, including international perspectives and…

  2. '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,...

  3. [Clinical research evolution. In parallel with the current changes in welfare expectations and information technology incorporation, study designs and data collection and analysis are quickly changing as well].

    Science.gov (United States)

    Tavazzi, Luigi

    2015-10-01

    The development of both technology, biological, and clinical knowledge leads to remarkable changes of scientific research methodology, including the clinical research. Major changes deal with the pragmatic approach of trial designs, an explosive diffusion of observational research which is becoming a usual component of clinical practice, and an active modelling of new research design. Moreover, a new healthcare landscape could be generated from the information technology routinely used to collect clinical data in huge databases, the management and the analytic methodology of big data, and the development of biological sensors compatible with the daily life delivering signals remotely forwardable to central databases. Precision medicine and individualized medicine seem to be the big novelties of the coming years, guiding to a shared pattern of patient/physician relationship. In healthcare, a huge business related mainly, but not exclusively, to the implementation of information technology is growing. This development will favor radical changes in the health systems, also reshaping the clinical activity. A new governance of the research strategies is needed and the application of the results should be based on shared ethical foundations. This new evolving profile of medical research and practice is discussed in this paper.

  4. Web evolution and Web Science

    OpenAIRE

    Hall, Wendy; Tiropanis, Thanassis

    2012-01-01

    This paper examines the evolution of the World Wide Web as a network of networks and discusses the emergence of Web Science as an interdisciplinary area that can provide us with insights on how the Web developed, and how it has affected and is affected by society. Through its different stages of evolution, the Web has gradually changed from a technological network of documents to a network where documents, data, people and organisations are interlinked in various and often unexpected ways. It...

  5. The mystery of language evolution

    OpenAIRE

    Hauser, Marc D.; Yang, Charles; Berwick, Robert C.; Tattersall, Ian; Ryan, Michael J.; Watumull, Jeffrey; Chomsky, Noam; Lewontin, Richard C.

    2014-01-01

    Understanding the evolution of language requires evidence regarding origins and processes that led to change. In the last 40 years, there has been an explosion of research on this problem as well as a sense that considerable progress has been made. We argue instead that the richness of ideas is accompanied by a poverty of evidence, with essentially no explanation of how and why our linguistic computations and representations evolved. We show that, to date, (1) studies of nonhuman animals prov...

  6. Functional mastery of percussive technology in nut-cracking and stone-flaking actions: experimental comparison and implications for the evolution of the human brain

    Science.gov (United States)

    Bril, Blandine; Smaers, Jeroen; Steele, James; Rein, Robert; Nonaka, Tetsushi; Dietrich, Gilles; Biryukova, Elena; Hirata, Satoshi; Roux, Valentine

    2012-01-01

    Various authors have suggested behavioural similarities between tool use in early hominins and chimpanzee nut cracking, where nut cracking might be interpreted as a precursor of more complex stone flaking. In this paper, we bring together and review two separate strands of research on chimpanzee and human tool use and cognitive abilities. Firstly, and in the greatest detail, we review our recent experimental work on behavioural organization and skill acquisition in nut-cracking and stone-knapping tasks, highlighting similarities and differences between the two tasks that may be informative for the interpretation of stone tools in the early archaeological record. Secondly, and more briefly, we outline a model of the comparative neuropsychology of primate tool use and discuss recent descriptive anatomical and statistical analyses of anthropoid primate brain evolution, focusing on cortico-cerebellar systems. By juxtaposing these two strands of research, we are able to identify unsolved problems that can usefully be addressed by future research in each of these two research areas. PMID:22106427

  7. Information Technology for Healthcare

    OpenAIRE

    Abbas Yazdanpanah

    2016-01-01

    The article produced below hopes to focus on the use of information technology solutions for improving healthcare delivery systems. It explains evolution of IT-Enhanced healthcare from Telemedicine to e-health, including definition and requirements of telemedical systems. It also traces the evolution of contemporary telemedical systems and the challenges faced by future technologies including legal and formal aspects of telemedicine as well as its acceptance among users. It overvi...

  8. Comparative performance analysis of shunt and series passive filter for LED lamp

    Science.gov (United States)

    Sarwono, Edi; Facta, Mochammad; Handoko, Susatyo

    2018-03-01

    Light Emitting Diode lamp or LED lamp nowadays is widely used by consumers as a new innovation in the lighting technologies due to its energy saving for low power consumption lamps for brighter light intensity. How ever, the LED lamp produce an electric pollutant known as harmonics. The harmonics is generated by rectifier as part of LED lamp circuit. The present of harmonics in current or voltage has made the source waveform from the grid is distorted. This distortion may cause inacurrate measurement, mall function, and excessive heating for any element at the grid. This paper present an analysis work of shunt and series filters to suppress the harmonics generated by the LED lamp circuit. The work was initiated by conducting several tests to investigate the harmonic content of voltage and currents. The measurements in this work were carried out by using HIOKI Power Quality Analyzer 3197. The measurement results showed that the harmonics current of tested LED lamps were above the limit of IEEE standard 519-2014. Based on the measurement results shunt and series filters were constructed as low pass filters. The bode analysis were appled during construction and prediction of the filters performance. Based on experimental results, the application of shunt filter at input side of LED lamp has reduced THD current up to 88%. On the other hand, the series filter has significantly reduced THD current up to 92%.

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

    Science.gov (United States)

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

    2017-01-01

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

  10. A Novel Heat Sink Design and Prototyping for LED Desk Lamps

    Directory of Open Access Journals (Sweden)

    Li-Ming Chu

    2015-01-01

    Full Text Available Light-emitting diode (LED is a modern lighting device. If the heat dissipating mechanism of LED desk lamp is not well designed, the induced high temperature will cause the reduction of illumination and life time of lamp. Therefore, the heat sink design becomes a key technology for LED lighting device. This study developed a methodology to design and analyze a heat sink for LED cooling. Four different types of heat sinks with fins in longitudinal or transverse directions and with or without vents on the base plate were compared. By using the CFD software FLUENT, heat flux and temperature around the heat sink were analyzed, and the surface temperature distribution was also investigated. The simulation outcomes were compared with experiments results to verify analysis accuracy. The comparisons show only slight differences, and the deviations were less than 4.0%. For cooling LED desk lamp, the design of using 12 vents on both sides of heat sink through natural convection to create the chimney effect was adopted; consequently, the temperature dropped 5°C in average. This design can also reduce the material of heat sink, LED lamp weight, and production cost.

  11. Novel Carbazole Skeleton-Based Photoinitiators for LED Polymerization and LED Projector 3D Printing

    Directory of Open Access Journals (Sweden)

    Assi Al Mousawi

    2017-12-01

    Full Text Available Radical chemistry is a very convenient way to produce polymer materials. Here, an application of a particular photoinduced radical chemistry is illustrated. Seven new carbazole derivatives Cd1–Cd7 are incorporated and proposed as high performance near-UV photoinitiators for both the free radical polymerization (FRP of (methacrylates and the cationic polymerization (CP of epoxides utilizing Light Emitting Diodes LEDs @405 nm. Excellent polymerization-initiating abilities are found and high final reactive function conversions are obtained. Interestingly, these new derivatives display much better near-UV polymerization-initiating abilities compared to a reference UV absorbing carbazole (CARET 9H-carbazole-9-ethanol demonstrating that the new substituents have good ability to red shift the absorption of the proposed photoinitiators. All the more strikingly, in combination with iodonium salt, Cd1–Cd7 are likewise preferred as cationic photoinitiators over the notable photoinitiator bis(2,4,6-trimethylbenzoylphenylphosphine oxide (BAPO for mild irradiation conditions featuring their remarkable reactivity. In particular their utilization in the preparation of new cationic resins for LED projector 3D printing is envisioned. A full picture of the included photochemical mechanisms is given.

  12. Sensing Light with LEDs: Performance Evaluation for IoT Applications

    Directory of Open Access Journals (Sweden)

    Lorenzo Incipini

    2017-11-01

    Full Text Available The Internet of Things includes all the technologies allowing the connection of everyday objects to the Internet, in order to gather measurements of physical quantities and interact with the surrounding environments through telecommunication devices with embedded sensing and actuating units. The measurements carried out with different LEDs demonstrate the possibility of using these devices both as transmitters and as optical sensors, in addition to their ability to discriminate incident wavelengths, thus making them bi-directional transceivers for Internet of Things (IoT applications, particularly suitable in the context of Visible Light Communication (VLC. In particular, a methodological tool is provided for selecting the LED sensor for VLC applications.

  13. Carrier Lifetimes in Fluorescent 6H-SiC for LEDs Application

    DEFF Research Database (Denmark)

    Grivickas, Vytautas; Gulbinas, Karolis; Jokubavičius, Valdas

    to acceptor pair recombination [1,2]. This combination can achieve higher electric-light conversion efficiency and high color rendering in comparison with today’s used blue GaN LED based and phosphors. The devices are promising candidates for general lightning applications and may obtain stability......Recently it was shown a new approach based on all-semiconductor material technology which is composed with a near ultra-violet GaN LED excitation source and fluorescent silicon carbide (f-6H-SiC) substrate which generates a visible broad spectral light by N and B dopants and an efficient donor...

  14. Energy-Saving Automation and LED Lighting Systems in Industry, Transport, Building and Municipal Sector

    Directory of Open Access Journals (Sweden)

    V.P. Klimenko

    2013-09-01

    Full Text Available Protocol of diverse technological data unification providing the ability to scale with a minimal increase in auxiliary information volume that allows its usage, ranging from the simplest microcontrollers to integration of automation equipment in global systems was designed for industrial automation systems. Basic technical solutions implemented in development of LED lighting systems of salon subway cars, including a schematic diagram of the lamp, the main technical characteristics of the lamp power supply, the peculiarities of developed design of LED modules are described.

  15. Optimum LED wavelength for underwater optical wireless communication at turbid water

    Science.gov (United States)

    Rosenkrantz, Etai; Arnon, Shlomi

    2014-10-01

    Underwater optical wireless communication is an emerging technology, which can provide high data rate. High data rate communication is required for applications such as underwater imaging, networks of sensors and swarms of underwater vehicles. These applications pursue an affordable light source, which can be obtained by light emitting diodes (LED). LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness based on off-the-shelf components such as blue and green light emitting diodes. In this paper we present our recent theoretical and experimental results in this field.

  16. Intra-Site Variability in the Still Bay Fauna at Blombos Cave: Implications for Explanatory Models of the Middle Stone Age Cultural and Technological Evolution.

    Directory of Open Access Journals (Sweden)

    Emmanuel Discamps

    Full Text Available To explain cultural and technological innovations in the Middle Stone Age (MSA of southern Africa, scholars invoke several factors. A major question in this research theme is whether MSA technocomplexes are adapted to a particular set of environmental conditions and subsistence strategies or, on the contrary, to a wide range of different foraging behaviours. While faunal studies provide key information for addressing these factors, most analyses do not assess intra-technocomplex variability of faunal exploitation (i.e. variability within MSA phases. In this study, we assess the spatial variability of the Still Bay fauna in one phase (M1 of the Blombos Cave sequence. Analyses of taxonomic composition, taphonomic alterations and combustion patterns reveal important faunal variability both across space (lateral variation in the post-depositional history of the deposits, spatial organisation of combustion features and over time (fine-scale diachronic changes throughout a single phase. Our results show how grouping material prior to zooarchaeological interpretations (e.g. by layer or phase can induce a loss of information. Finally, we discuss how multiple independent subdivisions of archaeological sequences can improve our understanding of both the timing of different changes (for example in technology, culture, subsistence, environment and how they may be inter-related.

  17. Microbial community evolution of black and stinking rivers during in situ remediation through micro-nano bubble and submerged resin floating bed technology.

    Science.gov (United States)

    Sun, Yanmei; Wang, Shiwei; Niu, Junfeng

    2018-06-01

    Microbes play important roles during river remediation and the interaction mechanism illustration between microorganisms and sewage is of great significance to improve restoration technology. In this study, micro-nano bubble and submerged resin floating bed composite technology (MBSR) was firstly used to restore two black and stinking urban rivers. After restoration, the water pollution indices such as dissolved oxygen (DO), ammonia nitrogen (NH 4 + -N), total phosphorous (TP), chemical oxygen demand (COD Cr ), water clarity, and the number of facial coliform were significantly improved. Microbial community composition and relative abundance both varied and more aerobic microbes emerged after remediation. The microbial changes showed correlation with DO, NH 4 + -N, TP and COD Cr of the rivers. In summary, the MBSR treatment improved the physiochemical properties of the two black and stinking urban rivers probably through oxygen enrichment of micro-nano bubble and adsorption of submerged resin floating bed, which thereby stimulated functional microbes to degrade pollutants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. The evolution of gasification processes and reactors and the utilization of the coal gas. A proposition for the implementation of the gasification technology

    International Nuclear Information System (INIS)

    Pasculete, E.; Iorgulescu, S.

    1996-01-01

    Thermochemical treatment of coal by gasification, considered as a non-polluting technology to turn the coal highly-profitably is one of the alternative ways to produce gas with a high effective caloric capacity. Due to its advantages, the gasification has made through the last few decades significant advances from the point of view of the process efficiency (chemical, thermal), of motor outputs (in m 3 producer gas / m 2 reactor cross section x hour), of the solutions of supplying energy to support the endothermic reactions implied by the process, and especially of the reactors. Reactors have been developed from gas generators. Starting from gas generators various advanced reactors (of 1 st to 3 rd generation) have been developed to produce air gas, water gas or mixed gas. Applications of the producer gas were developed using it either as fuel or as synthesis gas in chemical industry or else as a substitute to the natural gas in combined cycle gas turbines where the gasification plant was integrated. In Romania there are projects in the field of coal gasification, namely at ICPET-RESEARCH, that can offer advanced technologies. One of these projects deals with the construction of the first demonstrative gasification plant based on a highly efficient process and equipped with a 10 G cal/h reactor. (author). 1 tab., 12 refs

  19. The importance of the stimulation vessels in the Brazilian offshore basins: a history of technological evolution; A importancia dos barcos de estimulacao em bacias offshore brasileiras: uma historia de evolucao tecnologica

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Ricardo S.; Prata, Fernando Gaspar M.; Dean, Gregory D. [BJ Services do Brasil Ltda., RJ (Brazil)

    2004-07-01

    The Campos Basin is known as one of the most challenging deep water basins in the world. Currently there are thirty-seven platforms, more than a thousand oil wells, and about 4200 kilometers of submarine pipelines, having produced more than 1,2 billion barrels of oil per year and 15,7 million cubic meters of gas per day. The Campos Basin is responsible for more than 80% of Brazil's national production. Brazil intends to produce 2,2 million barrels of oil per day by 2007, when it will reach self-sufficiency. Therefore, the continued development of the offshore basins, such as Campos, Santos and Espirito Santo will be critical to meet this goal. In this context, the technological evolution of the vessels that render stimulation services is of fundamental importance to improve job quality, reduce time, protect with the environment, enable efficient communication, and ensure operational viability of new techniques. This paper reports on the history of this vessels, describing and illustrating new and state-of-the-art technology, historical cases of pioneering operations, data transmission in real time and the benefits for offshore operators with a global vision. (author)

  20. A UV LED-based Charge Management System for LISA

    Science.gov (United States)

    Conklin, John W.; Chilton, Andrew; Olatunde, Taiwo Janet; Apple, Stephen; Parry, Samantha; Ciani, Giacomo; Wass, Peter; Mueller, Guido

    2018-01-01

    The Laser Interferometer Space Antenna (LISA) will be the first space instrument to observe gravitational waves in the millihertz frequency band. LISA consists of three Sun-orbiting spacecraft that form an equilateral triangle, with each side measuring 2.5 million kilometers in length. Each spacecraft houses two free-floating test masses, which are protected from all disturbing forces so that they follow pure geodesics in spacetime. A drag-free control system commands micronewton thrusters to force the spacecraft to fly in formation with the test masses and laser interferometers measure the minute variations in the distance, or light travel time, between these free-falling test masses caused by gravitational waves. The LISA observatory, with a planned launch in the early 2030s, is led by the European Space Agency with significant contributions from NASA. Recently, NASA has initiated strategic investments in key LISA technologies that will likely become U.S. flight hardware contributions to this ground-breaking mission. One of these payload elements is the Charge Management System (CMS), which controls the electric potential of the test masses relative to their housings to reduce spurious force noise acting on the test masses to below the required level. This talk, presented by University of Florida team that leads the CMS development, will describe this vital U.S. contribution to the LISA mission in the context of the envisioned LISA payload architecture and its in-flight sensitivity to gravitational waves.

  1. Technical Feasibility Assessment of LED Roadway Lighting on the Golden Gate Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Tuenge, Jason R.

    2012-09-01

    Subsequent to preliminary investigations by the Golden Gate Bridge Highway & Transportation District (GGB), in coordination with Pacific Gas & Electric (PG&E), the GATEWAY Demonstration program was asked to evaluate the technical feasibility of replacing existing roadway lighting on the bridge with products utilizing LED technology. GGB and PG&E also indicated interest in induction (i.e., electrodeless fluorescent) technology, since both light source types feature rated lifetimes significantly exceeding those of the existing high-pressure sodium (HPS) and low-pressure sodium (LPS) products. The goal of the study was to identify any solutions which would reduce energy use and maintenance without compromising the quantity or quality of existing illumination. Products used for roadway lighting on the historic bridge must be installed within the existing amber-lensed shoebox-style luminaire housings. It was determined that induction technology does not appear to represent a viable alternative for the roadway luminaires in this application; any energy savings would be attributable to a reduction in light levels. Although no suitable LED retrofit kits were identified for installation within existing luminaire housings, several complete LED luminaires were found to offer energy savings of 6-18%, suggesting custom LED retrofit kits could be developed to match or exceed the performance of the existing shoeboxes. Luminaires utilizing ceramic metal halide (CMH) were also evaluated, and some were found to offer 28% energy savings, but these products might actually increase maintenance due to the shorter rated lamp life. Plasma technology was evaluated, as well, but no suitable products were identified. Analysis provided in this report was completed in May 2012. Although LED technologies are expected to become increasingly viable over time, and product mock-ups may reveal near-term solutions, some options not currently considered by GGB may ultimately merit evaluation. For

  2. Comparison between peer-led and teacher-led education in tuberculosis prevention in rural middle schools in Chongqing, China.

    Science.gov (United States)

    Liu, Qin; Liu, Liping; Vu, Huyen; Liu, Xiaoxue; Tang, Shenglan; Wang, Hong

    2015-03-01

    The aim of this study was to investigate the efficacy of tuberculosis (TB) education through a comparison of peer-led and teacher-led methods of education about TB prevention among middle school students in rural Chongqing, China. A preintervention and postintervention questionnaire survey was conducted in 2 different middle school student groups to measure changes in knowledge, attitude, and practice (KAP) status of those students before and after each TB education program. Of 1265 students participating in the preintervention survey, 1176 completed the postintervention survey. KAP scores of both peer-led and teacher-led groups after intervention improved by as much as 2 times compared with before the intervention and those of the control group (P led education group (P led group had a larger improvement than the peer-led group in practice scores (P < .01) in immediate effect evaluation. © 2013 APJPH.

  3. Development of high-performance solar LED lighting system

    KAUST Repository

    Huang, B.J.

    2010-08-01

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

  4. Animal evolution

    DEFF Research Database (Denmark)

    Nielsen, Claus

    This book provides a comprehensive analysis of evolution in the animal kingdom. It reviews the classical, morphological information from structure and embryology, as well as the new data gained from studies using immune stainings of nerves and muscles and blastomere markings, which makes it possi......This book provides a comprehensive analysis of evolution in the animal kingdom. It reviews the classical, morphological information from structure and embryology, as well as the new data gained from studies using immune stainings of nerves and muscles and blastomere markings, which makes...

  5. Intelligent control of dynamic LED lighting; Intelligent styring af dynamisk LED belysning. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, A.; Corell, D.; Hansen, Soeren S.; Dam-Hansen, C.; Petersen, Paul Michael

    2013-01-15

    The project has resulted in a prototype of a new intelligent lighting control system. The control system enables the end user to control his or her own local lighting environment (lighting zone) according to individual preferences and needs. The report provides a description of how the developed intelligent lighting system is composed and functions. The system is designed as a work lamp that enables dynamic change of the light color scheme according to a number of light control algorithms. It is specifically designed in relation to user tests of the intelligent lighting system, which is carried out in the final part of the project. An intelligent and advanced control of LED lighting was developed, which enables optimization of the user's light conditions in a given situation. Based on a number of known parameters, the system can control lighting so that at any time optimal light conditions are created, using a minimum of electric power. (LN)

  6. Characteristics of white LED transmission through a smoke screen

    Science.gov (United States)

    Zheng, Yunfei; Yang, Aiying; Feng, Lihui; Guo, Peng

    2018-01-01

    The characteristics of white LED transmission through a smoke screen is critical for visible light communication through a smoke screen. Based on the Mie scattering theory, the Monte Carlo transmission model is established. Based on the probability density function, the white LED sampling model is established according to the measured spectrum of a white LED and the distribution angle of the lambert model. The sampling model of smoke screen particle diameter is also established according to its distribution. We simulate numerically the influence the smoke thickness, the smoke concentration and the angle of irradiance of white LED on transmittance of the white LED. We construct a white LED smoke transmission experiment system. The measured result on the light transmittance and the smoke concentration agreed with the simulated result, and demonstrated the validity of simulation model for visible light transmission channel through a smoke screen.

  7. Competing in the Global LED Industry: The Case of Taiwan

    Directory of Open Access Journals (Sweden)

    Yu-Shan Su

    2014-01-01

    Full Text Available Light-emitting diode (LED is a very essential application for energy-savings nowadays. The revenue of the Taiwan LED components industry is ranked top one in the world, followed by that of Japan and South Korea. Based on the advantage of their electronics industry, Taiwanese LED companies create a unique model to compete with the international firms. Large international LED companies achieve economies of scale by vertically integrating their operations. Taiwanese LED companies specialize and achieve an optimal efficiency by vertically disintegrating across the upstream, midstream, and downstream sectors in the value chains. Taiwanese LED companies create economies of scale and economies of scope through a complete industrial value chain.

  8. Evolution of Cognitive Rehabilitation After Stroke From Traditional Techniques to Smart and Personalized Home-Based Information and Communication Technology Systems: Literature Review.

    Science.gov (United States)

    Cogollor, José M; Rojo-Lacal, Javier; Hermsdörfer, Joachim; Ferre, Manuel; Arredondo Waldmeyer, Maria Teresa; Giachritsis, Christos; Armstrong, Alan; Breñosa Martinez, Jose Manuel; Bautista Loza, Doris Anabelle; Sebastián, José María

    2018-03-26

    Neurological patients after stroke usually present cognitive deficits that cause dependencies in their daily living. These deficits mainly affect the performance of some of their daily activities. For that reason, stroke patients need long-term processes for their cognitive rehabilitation. Considering that classical techniques are focused on acting as guides and are dependent on help from therapists, significant efforts are being made to improve current methodologies and to use eHealth and Web-based architectures to implement information and communication technology (ICT) systems that achieve reliable, personalized, and home-based platforms to increase efficiency and level of attractiveness for patients and carers. The goal of this work was to provide an overview of the practices implemented for the assessment of stroke patients and cognitive rehabilitation. This study puts together traditional methods and the most recent personalized platforms based on ICT technologies and Internet of Things. A literature review has been distributed to a multidisciplinary team of researchers from engineering, psychology, and sport science fields. The systematic review has been focused on published scientific research, other European projects, and the most current innovative large-scale initiatives in the area. A total of 3469 results were retrieved from Web of Science, 284 studies from Journal of Medical Internet Research, and 15 European research projects from Community Research and Development Information Service from the last 15 years were reviewed for classification and selection regarding their relevance. A total of 7 relevant studies on the screening of stroke patients have been presented with 6 additional methods for the analysis of kinematics and 9 studies on the execution of goal-oriented activities. Meanwhile, the classical methods to provide cognitive rehabilitation have been classified in the 5 main techniques implemented. Finally, the review has been finalized with

  9. Evolution of MMI for 500 MWe PHWR plant

    International Nuclear Information System (INIS)

    Surendar, Ch.; Sharma, M.P.; Jayanthi, S.

    1994-01-01

    The Indian nuclear power programme for building Pressurized Heavy Water Reactors began with the construction of two units at Kota, Rajasthan. Although the concept of a centralized control room has been used since the beginning, the man-machine interface design has evolved with technological developments. The man-machine interaction in the earliest plants imposed a considerable burden on the operators and led to a need for more sophisticated instrumentation. Several microprocessor and computer based systems were identified and developed and many were retrofitted into existing plants providing immediate advantages. This paper traces the evolution of many of these systems and also describes the basis and the architecture for the man-machine interaction scheme in the 500 MWe nuclear power plants currently being designed. (author). 7 refs., 2 figs., 1 tab

  10. Dilemmas in the Analysis of Technological Change. A Cognitive Approach to Understand Innovation and Change in the Water Sector

    Directory of Open Access Journals (Sweden)

    Dino Borri

    2014-05-01

    Full Text Available In this paper we argue for the need to apply a cognitive approach to understand deep dynamics and determinants of technological evolutions. After examining main contributions from innovation studies to the conceptualization of innovation and change in complex socio-technical environments, we highlight the contribution coming from the application of the cognitive approach to evolutionary studies on technologies and we introduce the concept of technological memory as an interpretative tool to understand those changes. We discuss our hypothesis with reference to several observations carried out in different local contexts – Mexico, India and Italy – in relation to technological change in the water sector. In those cases deliberate attempts to substitute traditional technologies with modern ones led to interesting trajectories of change ranging from the collapse of old technologies to the development of multifaceted hybridization patterns.

  11. Kombineret dagslys og intelligent LED belysning - få dagslys ind i bygningerne

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten; Corell, Dennis Dan; Thorseth, Anders

    This report contains a description of the work carried out and the results of the research and development project ”Combined daylight and Intelligent LED lighting ‐ getting the daylight into the buildings” and form the final report for this project. The project is carried out in cooperation between...... the following partners: DTU Fotonik, Statens Byggeforsknings‐institut, Rambøll Danmark, Energirådgiveren and Philips Lighting Denmark. The project has been led by DTU Fotonik, Senior scientist, Ph.d. Carsten Dam‐Hansen The project was financed by the Danish Energy Association through Elforsk’s PSO program...... of the project, the work and results together with future perspectives of the results of the project. The report contains an overview of dynamic lighting systems and a description of the development of a new intelligent dynamic lighting system based on color mixing LED technology. The system, which has been...

  12. Epitaxial Growth of GaN-based LEDs on Simple Sacrificial Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Ian Ferguson; Chris Summers

    2009-12-31

    The objective of this project is to produce alternative substrate technologies for GaN-based LEDs by developing an ALD interlayer of Al{sub 2}O{sub 3} on sacrificial substrates such as ZnO and Si. A sacrificial substrate is used for device growth that can easily be removed using a wet chemical etchant leaving only the thin GaN epi-layer. After substrate removal, the GaN LED chip can then be mounted in several different ways to a metal heat sink/reflector and light extraction techniques can then be applied to the chip and compared for performance. Success in this work will lead to high efficiency LED devices with a simple low cost fabrication method and high product yield as stated by DOE goals for its solid state lighting portfolio.

  13. Leds used as spectral selective light detectors in remote sensing techniques

    International Nuclear Information System (INIS)

    Weber, C; Tocho, J O; Rodriguez, E J; Acciaresi, H A

    2011-01-01

    Remote sensing has been commonly considered as an effective technique in developing precision agriculture tools. Ground based and satellite spectral sensors have wide uses to retrieve remotely quantitative biophysical and biochemical characteristics of vegetation canopies as well as vegetation ground cover. Usually in-field remote sensing technologies use either a combination of interferential filters and photodiodes or different compact spectrometers to separate the spectral regions of interest. In this paper we present a new development of a sensor with LEDs used as spectrally selective photodetectors. Its performance was compared with a photodiode-filter sensor used in agronomic applications. Subsequent measurements of weed cover degree were performed and compared with other methodologies. Results show that the new LEDs based sensor has similar features that conventional ones to determining the weed soil cover degree; while LEDs based sensor has comparative advantages related its very low manufacturing cost and its robustness compatible with agricultural field applications.

  14. A novel amblyopia treatment system based on LED light source

    Science.gov (United States)

    Zhang, Xiaoqing; Chen, Qingshan; Wang, Xiaoling

    2011-05-01

    A novel LED (light emitting diode) light source of five different colors (white, red, green, blue and yellow) is adopted instead of conventional incandescent lamps for an amblyopia treatment system and seven training methods for rectifying amblyopia are incorporated so as for achieving an integrated therapy. The LED light source is designed to provide uniform illumination, adjustable light intensity and alterable colors. Experimental tests indicate that the LED light source operates steadily and fulfills the technical demand of amblyopia treatment.

  15. Development of Wireless Dimming Control System for LED Stage Light

    OpenAIRE

    Wang Hui Qin; Bai Shi Lei

    2016-01-01

    Compared with the existing wire dimming system of LED stage light which uses the heavy light operating console to adjust the brightness of stage light, a portable wireless dimming control system for LED stage lighting is proposed, fabricated and tested in this paper. The scheme with the core of ATmega16L microcontroller is composed of wireless transmission and reception units, constant current driving circuit of LED, and the control circuit between this two modules. Through the system present...

  16. Venom Evolution

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 18; Issue 3. Venom Evolution - Genetic and External Factors. Ema Fatima. Research News Volume 18 Issue 3 March 2013 pp 287-288. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/018/03/0287-0288 ...

  17. Representing Evolution

    DEFF Research Database (Denmark)

    Hedin, Gry

    2012-01-01

    . This article discusses Willumsen's etching in the context of evolutionary theory, arguing that Willumsen is a rare example of an artist who not only let the theory of evolution fuel his artistic imagination, but also concerned himself with a core issue of the theory, namely to what extent it could be applied...

  18. Art & Evolution

    Science.gov (United States)

    Terry, Mark

    2005-01-01

    In this article, the author presents a two-week evolution unit for his biology class. He uses Maria Sybilla Merian (1647-1717) as an example of an Enlightenment mind at work--in this case a woman recognized as one of the great artists and natural scientists of her time. Her representations of butterflies, caterpillars and their pupae, and the…

  19. Venom Evolution

    Indian Academy of Sciences (India)

    IAS Admin

    Venom Evolution. Genetic and External Factors. Ema Fatima. The term venom is used for a variety of toxins that are injected by certain animals into a victim through a specialized ... known to be an important evolutionary force. Gene duplication is the ... On the other hand, in species such as cone snails and snakes, where ...

  20. Demonstration Assessment of Light-Emitting Diode (LED) Parking Lot Lighting in Leavenworth, KS

    Energy Technology Data Exchange (ETDEWEB)

    Myer, Michael; Kinzey, Bruce R.; Curry, Ku' uipo

    2011-05-06

    This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a commercial parking lot lighting application, under the U.S. Department of Energy (DOE) Solid-State Lighting Technology GATEWAY Demonstration Program. The parking lot is for customers and employees of a Walmart Supercenter in Leavenworth, Kansas and this installation represents the first use of the LED Parking Lot Performance Specification developed by the DOE’s Commercial Building Energy Alliance. The application is a parking lot covering more than a half million square feet, lighted primarily by light-emitting diodes (LEDs). Metal halide wall packs were installed along the building facade. This site is new construction, so the installed baseline(s) were hypothetical designs. It was acknowledged early on that deviating from Walmart’s typical design would reduce the illuminance on the site. Walmart primarily uses 1000W pulse-start metal halide (PMH) lamps. In order to provide a comparison between both typical design and a design using conventional luminaires providing a lower illuminance, a 400W PMH design was also considered. As mentioned already, the illuminance would be reduced by shifting from the PMH system to the LED system. The Illuminating Engineering Society of North America (IES) provides recommended minimum illuminance values for parking lots. All designs exceeded the recommended illuminance values in IES RP-20, some by a wider margin than others. Energy savings from installing the LED system compared to the different PMH systems varied. Compared to the 1000W PMH system, the LED system would save 63 percent of the energy. However, this corresponds to a 68 percent reduction in illuminance as well. In comparison to the 400W PMH system, the LED system would save 44 percent of the energy and provide similar minimum illuminance values at the time of relamping. The LED system cost more than either of the PMH systems when comparing initial costs

  1. Warm white LEDs lighting over Ra=95 and its applications

    Science.gov (United States)

    Kobashi, Katsuya; Taguchi, Tsunemasa

    2007-02-01

    We have for the first time developed warm white LEDs lighting using a combination of near ultraviolet LED and three-band (red, green and blue) white phosphors. This LED has the average color-rendering index Ra=96. Moreover, special color-rendering index R9 (red) and R15 (face color of Japanese) are estimated to be 95 and 97, respectively. We will describe the results of evaluation on the medical lighting applications such as operation, treatment and endoscope experiments, application to the LED fashions and application to the Japanese antique art (ink painting) lighting.

  2. A synthetic method of solar spectrum based on LED

    Science.gov (United States)

    Wang, Ji-qiang; Su, Shi; Zhang, Guo-yu; Zhang, Jian

    2017-10-01

    A synthetic method of solar spectrum which based on the spectral characteristics of the solar spectrum and LED, and the principle of arbitrary spectral synthesis was studied by using 14 kinds of LED with different central wavelengths.The LED and solar spectrum data were selected by Origin Software firstly, then calculated the total number of LED for each center band by the transformation relation between brightness and illumination and Least Squares Curve Fit in Matlab.Finally, the spectrum curve of AM1.5 standard solar spectrum was obtained. The results met the technical indexes of the solar spectrum matching with ±20% and the solar constant with >0.5.

  3. Excellent color rendering indexes of multi-package white LEDs.

    Science.gov (United States)

    Oh, Ji Hye; Yang, Su Ji; Sung, Yeon-Goog; Do, Y R

    2012-08-27

    This study introduces multi-package white light-emitting diodes (LEDs) system with the ability to realize high luminous efficacy and an excellent color rendering index (CRI, R a) using the R B,M A B,M G B,M C B (R B,M A B,M G B,M denoted as a long-pass dichroic filter (LPDF)-capped, monochromatic red, amber and green phosphor converted-LED (pc-LED) pumped by a blue LED chip, and C B denoted as a cyan and blue mixed pc-LED pumped by a blue LED) system. The luminous efficacy and color rendering index (CRI) of multi-package white LED systems are compared while changing the concentration of the cyan phosphor used in the paste of a cyan-blue LED package and the driving current of individual LEDs in multi-package white LEDs at correlated color temperatures (CCTs) ranging from 6,500 K (cold white) to 2,700 K (warm white) using a set of eight CCTs as specified by the American National Standards Institute (ANSI) standard number C78.377-2008. A R B,M A B,M G B,M C B white LED system provides high luminous efficacy (≥ 96 lm/W) and a color rendering index (≥ 91) encompassing the complete CCT range. We also compare the optical properties of the R B,M A B,M G B,M C B system with those of the R B,M A B,M G B,M B and RAGB (red, amber, green, and blue semiconductor-type narrow-spectrum-band LEDs) systems. It can be expected that the cyan color added to a blue LED in multi-package white LEDs based on LPDF-capped, phosphor-converted monochromatic LEDs will meet the needs of the high-quality, highly efficient, full-color white LED lighting market in the near future.

  4. UV-LED Curing Efficiency of Wood Coatings

    OpenAIRE

    Landry, Véronic; Blanchet, Pierre; Boivin, Gabrielle; Bouffard, Jean-François; Vlad, Mirela

    2015-01-01

    Ultraviolet light emitting diodes (UV-LEDs) have attracted great interest in recent years. They can be used to polymerize coatings, such as those used for prefinished wood flooring. In this project, two lamps were compared for their suitability to be used on a wood flooring finishing line: a UV-microwave and a UV-LED lamp. Low heat emission was found for the UV-LED lamp compared to the UV-microwave one. This study also reveals that the 4 W/cm2 UV-LED lamp used is not powerful enough to cure ...

  5. High-Modulation-Speed LEDs Based on III-Nitride

    Science.gov (United States)

    Chen, Hong

    III-nitride InGaN light-emitting diodes (LEDs) enable wide range of applications in solid-state lighting, full-color displays, and high-speed visible-light communication. Conventional InGaN quantum well LEDs grown on polar c-plane substrate suffer from quantum confined Stark effect due to the large internal polarization-related fields, leading to a reduced radiative recombination rate and device efficiency, which limits the performance of InGaN LEDs in high-speed communication applications. To circumvent these negative effects, non-trivial-cavity designs such as flip-chip LEDs, metallic grating coated LEDs are proposed. This oral defense will show the works on the high-modulation-speed LEDs from basic ideas to applications. Fundamental principles such as rate equations for LEDs/laser diodes (LDs), plasmonic effects, Purcell effects will be briefly introduced. For applications, the modal properties of flip-chip LEDs are solved by implementing finite difference method in order to study the modulation response. The emission properties of highly polarized InGaN LEDs coated by metallic gratings are also investigated by finite difference time domain method.

  6. Evolution of Mobile Applications

    Directory of Open Access Journals (Sweden)

    Phongtraychack Anachack

    2018-01-01

    Full Text Available Currently, we can see the rapid evolution of mobile technology, which involves mobile communication, mobile hardware, and mobile software. Features of mobile phones largely depend on software. In contemporary information and communication age [1–4], mobile application is one of the most concerned and rapidly developing areas. At the same time, the development of mobile application undergoes great changes with the introduction of new software, service platforms and software development kits (SDK. These changes lead to appearance of many new service platforms such as Google with Android and Apple with iOS. This article presents the information about the evolution of mobile application, gives some statistical data on the past and present situation, demonstrates how individual users of mobile devices can benefit, and shows how mobile applications affect society from the ethical perspective.

  7. ISDN technology

    CERN Document Server

    Brewster, R L

    1993-01-01

    The Integrated Services Digital Network (ISDN) represents the current position in about a hundred years of evolutionary growth of the worldwide telecommunications infrastructure. This evolution is by no means complete and the next few years will see the emergence of a "Broad-band" ISDN as the next stage of evolutionary development. It is important to appreciate the evolutionary nature of the telecommunications infrastructure if one is to properly understand much of the thinking that lies behind the current ISDN proposals. This book therefore begins with a number of chapters devoted to a study of the various developments which have eventually led to the concept of an integrated digital network. These include the development of digital transmission of speech using PCM and the development of digital switching techniques based on stored program control. The book then turns to a consideration of those features of the existing telecommunications network which need to be modified in order to make ISDN a realizable p...

  8. Evolution of dwarf binaries

    International Nuclear Information System (INIS)

    Tutukov, A.V.; Fedorova, A.V.; Yungel'son, L.R.

    1982-01-01

    The conditions of mass exchange in close binary systems with masses of components less or equal to one solar mass have been analysed for the case, when the system radiates gravitational waves. It has been shown that the mass exchange rate depends in a certain way on the mass ratio of components and on the mass of component that fills its inner critical lobe. The comparison of observed periods, masses of contact components, and mass exchange rates of observed cataclysmic binaries have led to the conclusion that the evolution of close binaries WZ Sge, OY Car, Z Cha, TT Ari, 2A 0311-227, and G 61-29 may be driven by the emission of gravitational waves [ru

  9. Fabrication of nano-patterned sapphire substrates and their application to the improvement of the performance of GaN-based LEDs

    International Nuclear Information System (INIS)

    Gao Haiyong; Yan Fawang; Zhang Yang; Li Jinmin; Zeng Yiping; Wang Guohong

    2008-01-01

    Nano-patterned sapphire substrates (NPSSs) were fabricated by a chemical wet etching technology using nano-sized SiO 2 as masks. The NPSS was applied to improve the performance of GaN-based light emitting diodes (LEDs). GaN-based LEDs on NPSSs were grown by metal organic chemical vapour deposition. The characteristics of LEDs grown on NPSSs and conventional planar sapphire substrates were studied. The light output powers of the LEDs fabricated on NPSSs were considerably enhanced compared with that of the conventional LEDs grown on planar sapphire substrates

  10. Comparison of UV-LED and low pressure UV for water disinfection: Photoreactivation and dark repair of Escherichia coli.

    Science.gov (United States)

    Li, Guo-Qiang; Wang, Wen-Long; Huo, Zheng-Yang; Lu, Yun; Hu, Hong-Ying

    2017-12-01

    Studies on ultraviolet light-emitting diode (UV-LED) water disinfection have shown advantages, such as safety, flexible design, and lower starting voltages. However, information about reactivation after UV-LED disinfection is limited, which is an important issue of UV light-based technology. In this study, the photoreactivation and dark repair of Escherichia coli after UV-LEDs and low pressure (LP) UV disinfection were compared. Four UV-LED units, 265 nm, 280 nm, the combination of 265 + 280 (50%), and 265 + 280 (75%) were tested. 265 nm LEDs was more effective than 280 nm LEDs and LP UV lamps for E. coli inactivation. No synergic effect for disinfection was observed from the combination of 265 and 280 nm LEDs. 265 nm LEDs had no different reactivation performances with that of LP UV, while 280 nm LEDs could significantly repress photoreactivation and dark repair at a low irradiation intensity of 6.9 mJ/cm 2 . Furthermore, the UV-induced damage of 280 nm LEDs was less repaired which was determined by endonuclease sensitive site (ESS) assay. The impaired protein activities by 280 nm LEDs might be one of the reasons that inhibited reactivation. A new reactivation rate constant, K max , was introduced into the logistic model to simulate the reactivation data, which showed positive relationship with the maximum survival ratio and was more reasonable to interpret the results of photoreactivation and dark repair. This study revealed the distinct roles of different UV lights in disinfection and reactivation, which is helpful for the future design of UV-LED equipment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Demonstration of LED Retrofit Lamps at the Smithsonian American Art Museum, Washington, DC

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Naomi J.; Rosenfeld, Scott M.

    2012-06-22

    This report documents observations and results obtained from a lighting demonstration project conducted under the U.S. Department of Energy GATEWAY Solid-State Lighting (SSL) Technology Demonstration Program at the Smithsonain American Art Museum in Washington, DC. LED Lamp samples were tested in the museum workshop, temporarily installed in a gallery for feedback, and ultimately replaced all traditional incandescent lamps in one gallery of modernist art at the American Art Museum and partially replacing lamps in two galleries at the Musesum's Renwick Gallery. This report describes the selection and testing process, technology challenges, perceptions, economics, energy use, and mixed results of usign LED replacement lamps in art galleries housing national treasures.

  12. A comparison of midwife-led care versus obstetrician-led care for low-risk women in Japan.

    Science.gov (United States)

    Iida, Mariko; Horiuchi, Shigeko; Nagamori, Kumiko

    2014-09-01

    Continuity of midwife-led care is recommended in maternity care because of its various positive outcomes. In Japan, midwife-led care is receiving broad attention as well. In order to popularise midwifery care within the entire system of perinatal care in Japan, there is a need to show evidence that continuity of midwife care for women will bring about positive outcomes. The objectives of this study were to compare the health outcomes of women and infants who received midwife-led care with obstetrician-led care in Japan. This was an observational study using non-random purposive sampling with a survey questionnaire. Settings where midwife-led care and obstetrician-led care were chosen by purposive samples. Participants were low-risk women who received antenatal care and delivered a term-singleton-infant at the participating settings during the research period. Measurements were: Women-centred care pregnancy questionnaire, Stein's maternity blues questionnaire, and Edinburgh Postnatal Depression Scale. Midwife-led care was perceived by women to be beneficial and had no adverse outcomes compared to obstetrician-led care. Main findings are: (1) Perception of Women-centred care was higher; (2) Less premature rupture of membranes, and the Apgar scores of the infants were similar; (3) Exclusively breast-feeding during hospitalisation and at one-month postpartum; (4) Stein's maternity blues scale scores was lower in women who received midwife-led care than those who received obstetrician-led care. Continuity of midwife-led care was perceived by women to be beneficial and had no adverse outcomes. Therefore, midwife-led care in low-risk pregnancy could be applicable and recommended. Copyright © 2014 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Hopmann, Christian; Röbig, Malte

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-09

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

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

    Science.gov (United States)

    West, Robert S.

    2002-11-01

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

  16. Application of light-emitting diodes (LEDs) in cultivation of phototrophic microalgae: current state and perspectives.

    Science.gov (United States)

    Glemser, M; Heining, M; Schmidt, J; Becker, A; Garbe, D; Buchholz, R; Brück, T

    2016-02-01

    The quality and regulation of the incident light is crucial in microalgae cultivation processes. Depending on wavelength, spectrum, and intensity, growth characteristics and biochemical composition of these organisms vary. With mainly fluorescent lamps (FL) used previously for illumination, such variabilities could not be studied adequately due to their broad emission spectrum. In contrast, light-emitting diodes (LEDs) emit a very narrow wavelength band and enable flexible photobioreactor designs due to their small size. This review provides a condensed overview on the application of LEDs in microalgal cultivation processes. It summarizes the current availability and applicability of LED technologies as an illumination source for research-focused photobioreactor systems. A particular focus is the use of narrow-wavelength LEDs to address fundamental as well as applied aspects of light color on algae biomass and value-added compound formation. In this respect, the application of internal and external illumination systems is reviewed together with trends in the industrial use of LED systems to intensify algae process efficiency.

  17. Non-destructive inspection methods for LEDs using real-time displaying Optical Coherence Tomography.

    Science.gov (United States)

    Cho, Nam Hyun; Jung, Unsang; Kim, Suhwan; Kim, Jeehyun

    2012-01-01

    In this study, we report the applicability of two different Optical Coherence Tomography (OCT) technologies for inspecting Light Emitting Diode (LED) structures. Sectional images of a LED were captured using a Spectral Domain OCT (SD-OCT) system and a Swept Source OCT (SS-OCT) system. Their center wavelengths are 850 and 1,310 nm, respectively. We acquired cross-sectional two dimensional (2D) images of a normal LED and extracted sectional profiles to inspect possible wire disconnection that may be present in the LED manufacturing process. The SD-OCT and SS-OCT images were compared with each other in the same sample to study their advantages. The distribution of fluorescence material was observed more clearly with the SD-OCT of 850 nm wavelength, whereas the status of wire connection was clearer in the SS-OCT images with 1,310 nm wavelength. In addition, the volume of the fluorophore space was calculated from the OCT images. This is the first report that a nondestructive optical imaging modality such as OCT can be applied to finding screen defects in LED. We expect this method can improve the inspection efficacy over traditional inspection methods such as Charged Coupled Device (CCD) camera or X-ray instruments.

  18. Non-Destructive Inspection Methods for LEDs Using Real-Time Displaying Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Suhwan Kim

    2012-07-01

    Full Text Available In this study, we report the applicability of two different Optical Coherence Tomography (OCT technologies for inspecting Light Emitting Diode (LED structures. Sectional images of a LED were captured using a Spectral Domain OCT (SD-OCT system and a Swept Source OCT (SS-OCT system. Their center wavelengths are 850 and 1,310 nm, respectively. We acquired cross-sectional two dimensional (2D images of a normal LED and extracted sectional profiles to inspect possible wire disconnection that may be present in the LED manufacturing process. The SD-OCT and SS-OCT images were compared with each other in the same sample to study their advantages. The distribution of fluorescence material was observed more clearly with the SD-OCT of 850 nm wavelength, whereas the status of wire connection was clearer in the SS-OCT images with 1,310 nm wavelength. In addition, the volume of the fluorophore space was calculated from the OCT images. This is the first report that a nondestructive optical imaging modality such as OCT can be applied to finding screen defects in LED. We expect this method can improve the inspection efficacy over traditional inspection methods such as Charged Coupled Device (CCD camera or X-ray instruments.

  19. Study and Implementation of White Power-LED Based Indoor Lighting Application for the Healthcare Sector

    Science.gov (United States)

    Chakraborty, A.; Ganguly, R.

    With the current technological growth in the field of device fabrication, white power-LED's are available for solid state lighting applications. This is a paradigm shift from electrical lighting to electronic lighting. The implemented systems are showing some promise by saving a considerable amount of energy as well as providing a good and acceptable illumination level. However, the `useful life' of such devices is an important parameter. If the proper device is not chosen, the desired reliability and performance will not be obtained. In the present work, different parameters associated with reliability of such LED's are studied. Four different varieties of LED's are put to test the `useful life' as per IESNA LM 79 standard. From the results obtained, the proper LED is chosen for further application. Subsequently, lighting design is done for a hospital waiting room (indoor application) with 24 × 7 lighting requirements for replacement of existing CFLs there. The calculations show that although the initial cost is higher for LED based lighting, yet the savings on energy and replacement of the lamp results in a payback time of less than a year.

  20. Air Base Wing and Air Mobility Wing Consolidating on AMC-LED Joint Bases: A Delphi Study

    Science.gov (United States)

    2014-06-13

    AIR BASE WING AND AIR MOBILITY WING CONSOLIDATION ON AMC-LED JOINT BASES: A DELPHI STUDY GRADUATE RESEARCH PAPER Mason E. MacGarvey... DELPHI STUDY GRADUATE RESEARCH PAPER Presented to the Faculty Graduate School of Engineering Management Air Force Institute of Technology...iv AIR BASE WING AND AIR MOBILITY WING CONSOLIDATION ON AMC-LED JOINT BASES: A DELPHI STUDY Mason E. MacGarvey, BS, MBA

  1. Time effectiveness of Ultraviolet C light (UVC) emitted by Light Emitting Diodes (LEDs) in reducing stethoscope contamination

    OpenAIRE

    Messina, Gabriele; Fattorini, Mattia; Nante, Nicola; Rosadini, Daniele; Serafini, Andrea; Tani, Marco; Cevenini, Gabriele

    2016-01-01

    Today it is well demonstrated that stethoscopes can be as contaminated as hands, which are a recognized source of Health-Care Associated Infections (HCAIs). Ultraviolet C (UVC) light has proven disinfection capacity and the innovative UVC technology of Light Emitting Diode (LED) shows several potential benefits. To verify whether the use of UVC LEDs is effective and reliable in stethoscope membrane disinfection after prolonged use, a pre-post intervention study was conducted. A total of 1668 ...

  2. The resolved history of galaxy evolution.

    Science.gov (United States)

    Brinchmann, Jarle

    2002-12-15

    We briefly review the study of the evolution of galaxies from an observational point of view, with particular emphasis on the role of the Hubble Space Telescope in probing the evolution of the different morphological types of galaxy. We show how using the stellar mass of galaxies as a tracer of evolution can improve our understanding of the physical process taking place before turning our eyes towards the future and giving an overview of what we can expect from future advances in technology.

  3. Student-Led Objective Tutorial (SLOT) in Medical Education.

    Science.gov (United States)

    Sivagnanam, Gurusamy; Saraswathi, Simansalam; Rajasekaran, Aiyalu

    2006-12-01

    Purpose - To assess an innovative tutoring program named 'Student-Led Objective Tutorial' (SLOT) among undergraduate medical students. Method - The program was conceptualized by the Pharmacology Unit of Faculty of Medicine and Health Sciences, Asian Institute of Medicine Science & Technology (AIMST), Malaysia and implemented in the middle of 2005. A cohort of 246 medical undergraduate students (spread across 5 consecutive batches) participated. Following a brief explanation on the purpose and nature of SLOT, each batch was divided into small groups and was given a reading assignment on 4 previously delivered lecture topics. Each group was asked to prepare 3-5 multiple choice questions (MCQs) of their own in PowerPoint format to be presented, in turns, to the whole class on the day of SLOT. The proceedings were facilitated by 2 lecturers. Student feedback on the efficacy and benefits were assessed through an anonymous self administered questionnaire. Results - About 76% (188) of the students favored SLOT. The acceptance rate of SLOT was higher among males. There was no significant difference between batches in their opinions on whether to pursue SLOT in future. The most prevalent positive comment was that SLOT enhanced learning skills, and the negative comment being, it consumed more time. Conclusions - SLOT is a novel tutorial method which can offset faculty shortage with advantages like enhanced interest among teachers and learners, uniform reach of content, opportunities for group learning, and involvement of visual aids as teaching-learning (T-L) method. SLOT unraveled the students' potential of peer tutoring both inside as well as outside the classroom. Consumer tutors (students) can be tapped as a resource for SLOT for all subjects and courses in healthcare teaching.

  4. Monte carlo analysis of multicolour LED light engine

    DEFF Research Database (Denmark)

    Chakrabarti, Maumita; Thorseth, Anders; Jepsen, Jørgen

    2015-01-01

    A new Monte Carlo simulation as a tool for analysing colour feedback systems is presented here to analyse the colour uncertainties and achievable stability in a multicolour dynamic LED system. The Monte Carlo analysis presented here is based on an experimental investigation of a multicolour LED...

  5. Tuning the color point of a white LED

    NARCIS (Netherlands)

    Adhikary, Manashee; Meretska, Maryna; Ladovrechis, K.; Fokkema, Wouter K.; Vissenberg, Gilles; Lagendijk, Ad; Ijzerman, W.L.; Vos, Willem L.

    2018-01-01

    White light is conveniently characterized by a color point that is represented on the color space. Color point of white LED is fixed by the design parameters (e.g. Phosphor type and concentration). When the design parameters are chosen, the color point of the white LED cannot be changed. Here, we

  6. The Lifetime Prediction of LED Drivers and Lamps

    NARCIS (Netherlands)

    Sun, B.

    2017-01-01

    Light-Emitting Diodes (LEDs) have become a very promising alternative lighting source with the main advantages of a longer lifetime and a higher efficiency than traditional ones. However, the LED lamp’s lifetime is compromised by its driver’s reliability. Although extensive studies have been made on

  7. Development of an intelligent integrated LED system-in-package

    NARCIS (Netherlands)

    Gielen, A.W.J.; Hesen, P.; Swartjes, F.H.M.; Zeijl, H. van; Boschman, F.; Bullema, J.-E.; Werkhoven, R.J.; Koh, S.

    2011-01-01

    Intelligent LED lighting systems can save up to 80% of energy compared to traditional lighting systems. In order to provide these intelligent lighting products at reaseonable costs, integration and miniaturisation are important steps. To this end we have designed a LED system-in-package that

  8. Assessment of community led total sanitation uptake in rural Kenya ...

    African Journals Online (AJOL)

    Background: Community Led Total Sanitation (CLTS) is an innovative community led drive to set up pit latrines in rural Kenya with an aim of promoting sustainable sanitation through behaviour change. It's a behaviour change approach based on social capital that triggers households to build pit latrines without subsidy.

  9. Led enhancement in mitochondrial oxidative phosphorylation for hepatectomized rats

    Directory of Open Access Journals (Sweden)

    Orlando de Castro-e-Silva Jr

    2002-01-01

    Full Text Available Recently, the LED (light emitting diode developed by the Optics Group of IFSC-USP has been used instead of laser for the treatment of skin tumors by the PDT (Photodinamic Therapy because of its low operational cost compared to the use of a laser. In this paper we investigate the effect of LED light on oxidative phosphorylation during liver regeneration after partial hepatectomy. Twenty-four male Wistar rats (250 g were kept in identical housing units on a 12-hour light/12 hour dark cycle. The LED 10 group was exposed to LED at 638 nm (10 J/cm² for 3 minutes. Seventy percent partial hepatectomy was performed in the LED 10 and HPC (Partial Hepatectomy-Control. A sham-operated group (C was used for control. Twenty four hours after the procedure, LED 10, HPC and control animals were sacrificed. Samples of liver tissue were used for the mitochondrial respiration assay. Statistical comparisons of the groups were performed by analysis of variance (ANOVA, followed by the Bonferroni post-test. Probability values less than 0.05 were considered to be statistically significant. the phosphorylation index (FI for the LED 10 group was higher than that for the HPC group and for the sham group (p 0.05. In the present study we noted an effective interaction between LED light and hepatic mitochondria, with an increased phosphorylation rate for the latter.

  10. The WIMSE-E module W-LED

    International Nuclear Information System (INIS)

    Roth, M.J.

    1992-06-01

    This report describes the WIMS-E edit module W-LED. W-LED sets up a library of cross section and other nuclear data for a set of materials for subsequent use in a whole reactor program such as PANTHER. (author)

  11. Thermal analysis of LED lamps for optimal driver integration

    NARCIS (Netherlands)

    Perpiñà, X.; Werkhoven, R.J.; Vellvehi, M.; Jakovenko, J.; Jordà, X.; Kunen, J.M.G.; Bancken, P.; Bolt, P.J.

    2015-01-01

    This paper studies the thermal influence of a light-emitting diode (LED) driver on a retrofit LED lamp, also reporting on a procedure for its thermal characterization and multiscale modeling. In this analysis, temperature is measured by infrared thermography and monitoring specific locations with

  12. Student-Led Parent Conferences: A Model for Teaching Responsibility.

    Science.gov (United States)

    Guyton, Jane M.; Fielstein, Lynda L.

    1989-01-01

    Describes program in which elementary school students lead parent-teacher conferences, shares authors' experiences with the student-led conferences, and discusses how the process has fostered student responsibility. Describes results of informal study that support the student-led conference. (NB)

  13. Low Cost Lithography Tool for High Brightness LED Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Hawryluk; Emily True

    2012-06-30

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

  14. Shortest exposure time possible with LED curing lights

    NARCIS (Netherlands)

    Busemann, I.; Lipke, C.; Schattenberg, A.V.M.B.; Willershausen, B.; Ernst, C.P.

    2011-01-01

    PURPOSE: To investigate the shortest exposure time of different light emitting diode (LED)-curing devices for different resin composites in a clinically relevant laboratory model. METHODS: Nine LED curing devices (Bluephase, Bluephase 16i, Bluephase G2, Bluephase 20i/Ivoclar Vivadent, DEMI/sds Kerr,

  15. The effect of LED illumination on endodontic biofilms

    DEFF Research Database (Denmark)

    Markvart, Merete

    nm) and UVC (266nm) region. The PDT was applied using the commercial product Fotosan®. The UV LEDs were able to eliminate the E. faecalis biofilm while the PDT was only able to make a reduction in the total number of viable cells. UV LEDs may improve disinfection procedures during root canal...

  16. Luminous flux and colour maintenance investigation of integrated LED lamps

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Thorseth, Anders; Dam-Hansen, Carsten

    2014-01-01

    This article will present an investigation of the luminous flux and colour maintenance of white LED based retrofit lamps. The study includes 23 different types of integrated LED lamps, covering 18 directional and 5 non-directional. Luminous flux and colour data for operation up to 20000 h has been...

  17. Design of LED lamps | Ashryatov | Journal of Fundamental and ...

    African Journals Online (AJOL)

    The variant of the lighting system energy efficiency increase with luminaires and linear fluorescent lamps is considered. In the proposed variant, the fluorescent lamps and start regulating devices are replaced with linear LED modules. In order to reduce the glossiness of a luminaire, the LED modules must be covered with ...

  18. Improved power quality based high brightness LED lamp driver ...

    African Journals Online (AJOL)

    This paper deals with a power factor corrected (PFC) improved power quality based LED lamp driver. The proposed driver consists of a PFC Cuk DC-DC converter which operates in continuous conduction mode (CCM) to improve the power quality at input AC mains. The design, modeling and simulation of an 18W LED (six ...

  19. Indoor visual positioning system using LED and mobile phone

    Science.gov (United States)

    Gong, Yingkui; Shi, Zhengfa; Wang, Yuqi

    2016-01-01

    An indoor visual positioning system is proposed, which using four or more LED ceiling lamps and a mobile phone. A 4*4 photodiode array is attached to the mobile phone to receive the three-dimensional coordinates of the LED lamps via visible light communication, and the front camera of the mobile phone is used to receive the high resolution image of the LED lamps. The mobile phone's three-dimensional coordinates can be determined by matching the spot information and three-dimensional coordinates of the LED lamps with the image information provided by the mobile phone. An improved collinear equation model is proposed to build the mapping relationship between the three-dimensional coordinates of the LED lamps and the image information acquired by the front camera. A semi-physical simulation has been conducted and analyzed. The positioning scheme is proved to be valid and the positioning accuracy is up to decimeter level.

  20. Investigation of irradiance efficiency for LED phototherapy with different arrays

    Science.gov (United States)

    Chen, Hsi-Chao; Wu, Guo-Yang

    2010-12-01

    Red and yellow light emitting diodes (LEDs) are currently utilized as lighting sources during LED phototherapy. These LEDs were arranged on a disk with an external diameter of 70 mm with different arrays — radial, rhombus, square radial, and square rhombus arrays. The radial and square radial arrays had better irradiance efficiency than rhombus and square rhombus arrays by optical simulation. Additionally, the radial array had 76 sets of LEDs, but the square radial array had 100 sets. Thus, a mockup sample of radial array phototherapy was constructed for performance tests. The mixture efficiency of the radial array was observed at distances of 1-100 mm and lighting was well mixed when distance exceeded 50 mm by optical simulation. Irradiance variation with angle was approximated by experiment and theory at a treatment distance of 50 mm and 100 mm using the phototherapy mockup. The radial array was one good choice for LED phototherapy.

  1. The LED monitoring system of the PHOENICS experiment

    International Nuclear Information System (INIS)

    Urban, D.

    1991-07-01

    The PHOENICS experiment at ELSA uses a LED monitoring system to control pulse height and time measurement with scintillation counters. A green LED is mounted at the light guide of each of the 304 involved photomultiplier tubes. The LEDs are driven by fast voltage pulses of 5 ns FWHM width and about 20 V amplitude. Simulation of single events is possible by computer controlled switching of individual LEDs. In order to correct for the temperature dependence of the LED intensity an automatic temperature recording system was coupled to the computer. This monitor system allows to control the pulse height and time measurement with an accuracy of about 2% and 100 ps respectively. (orig.) [de

  2. Uric acid and evolution.

    Science.gov (United States)

    Álvarez-Lario, Bonifacio; Macarrón-Vicente, Jesús

    2010-11-01

    Uric acid (UA) is the end product of purine metabolism in humans due to the loss of uricase activity by various mutations of its gene during the Miocene epoch, which led to humans having higher UA levels than other mammals. Furthermore, 90% of UA filtered by the kidneys is reabsorbed, instead of being excreted. These facts suggest that evolution and physiology have not treated UA as a harmful waste product, but as something beneficial that has to be kept. This has led various researchers to think about the possible evolutionary advantages of the loss of uricase and the subsequent increase in UA levels. It has been argued that due to the powerful antioxidant activity of UA, the evolutionary benefit could be the increased life expectancy of hominids. For other authors, the loss of uricase and the increase in UA could be a mechanism to maintain blood pressure in times of very low salt ingestion. The oldest hypothesis associates the increase in UA with higher intelligence in humans. Finally, UA has protective effects against several neurodegenerative diseases, suggesting it could have interesting actions on neuronal development and function. These hypotheses are discussed from an evolutionary perspective and their clinical significance. UA has some obvious harmful effects, and some, not so well-known, beneficial effects as an antioxidant and neuroprotector.

  3. Computed Tomography. Evolution, technical principles and applications

    International Nuclear Information System (INIS)

    Calzado, A.; Geleijns, J.

    2010-01-01

    Computed tomography has become one of the most commonly used diagnostic techniques. Since its clinical introduction in 1971, subsequent developments have led to the emergence of new indications in different medical specialties. This paper reviews the evolution of art; essential characteristics of CT scanners are described and different application modalities in diagnosis are reviewed as well. (Author).

  4. Evolution to 3G Mobile Communication

    Indian Academy of Sciences (India)

    The evolution to higher data rates and more advanced services ... applications. The limiting factor to providing these new services is the transmission data rate. It has taken a decade to bring reasonable speeds to the desktop using Integrated Services Data .... especially in big cities, on the other hand, led to the develop-.

  5. Research on thermal characteristics of heat pipes for led lightning devices

    Directory of Open Access Journals (Sweden)

    Lozovoi M. A.

    2014-12-01

    Full Text Available New energy-saving technologies for lighting is a promising trend in lighting technology. To this end, during the recent decade, have been actively developed and implemented lighting units based on LED modules. Reliability of such devices is largely dependent on the ensuring of cooling of the LEDs. Heat pipes are being used with ever increasing frequency for increasing an efficiency of cooling of powerful LEDs within a lightening device. Results of experimental modeling of thermal characteristics of two aluminum heat pipes with grooved capillary structure and ammonia used as a heat transfer agent, designed for application as a heat transfer elements in designs of powerful LED lightening device with forced air cooling are presented in this paper. It is shown that for the heat flux range of 50 to 100 W and for incident flow speed in the range of 0.8 to 2.1 m/s the temperature in the heating zone of the heat pipe falls into the range of 31.0 to 52.5 °C. In this case the temperature difference along the heat pipe is between 0.9…1.7 °C, when a minimal value of the fed heat flux is 50 W, and 1.7…3.1°C, when a maximum value of the heat flux is 100 W. The value of heat transfer resistance of the heat pipes was in the range of 0.012 to 0.044 °C/W. The key factors influencing the thermal characteristics of the heat pipes are: the value of the fed heat flux, the speed of cooling air flux, heat pipe inclination angle with respect to the horizon. By using five such heat pipes within the powerful LED lightning device it is possible to achieve an elimination of the total heat flux from LED modules up to 500 W. At an efficiency factor of LEDs of about 75% this is equivalent to intake power 665 W. Taking into account that luminous efficiency of modern LEDs is about 10 times as high as those of incandescent lamps, proposed lightning device will produce a luminous flux which is equivalent to the luminous flux of a lightening device with incandescent lamps

  6. Supporting Product Line Evolution with Framed Aspects

    DEFF Research Database (Denmark)

    Loughran, Neil; Rashid, Awais; Zhang, Weishan

    2004-01-01

    This paper discusses how evolution in software product lines can be supported using framed aspects: a combination of aspect-oriented programming and frame technology. Product line architectures and assets are subject to maintenance and evolution throughout their lifetime due to the emergence of new...... of both technologies in combination. The amalgamation of framing and aspect-oriented techniques can help in the integration of new features and thus reduce the risk of architectural erosion....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-19

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

  8. Peer-led and professional-led group interventions for people with co-occurring disorders: a qualitative study.

    Science.gov (United States)

    Pallaveshi, Luljeta; Balachandra, Krishna; Subramanian, Priya; Rudnick, Abraham

    2014-05-01

    This pilot study evaluated the experience of people with co-occurring disorders (mental illness and addiction) in relation to peer-led and professional-led group interventions. The study used a qualitative (phenomenological) approach to evaluate the experience of a convenience sample of 6 individuals with co-occurring disorders who participated in up to 8 sessions each of both peer-led and professional-led group interventions (with a similar rate of attendance in both groups). The semi-structured interview data were coded and thematically analyzed. We found 5 themes within and across the 2 interventions. In both groups, participants experienced a positive environment and personal growth, and learned, albeit different things. They were more comfortable in the peer-led group and acquired more knowledge and skills in the professional-led group. Offering both peer-led and professional-led group interventions to people with co-occurring disorders may be better than offering either alone.

  9. Evolution of civil aeromedical helicopter aviation.

    Science.gov (United States)

    Meier, D R; Samper, E R

    1989-07-01

    The rapid increase in the use of helicopters for hospital transport during the 1980s is the culmination of several hundred years of military medical innovation. Mass battefield casualties spurred both technologic and medical changes necessary for today's sophisticated helicopter systems in use worldwide, particularly in the United States. The Napoleonic Era and the American Civil War provided the framework for the evolution of today's state-of-the-art emergency medical techniques. The use of airplanes to evacuate the wounded eventually led to using helicopters for rescue missions in World War II. The combat experiences of the United States in Korea, the British in Malaya, and the French in Indochina proved that rotary-wing aircraft were invaluable in reducing battlefield death rates. Any skepticism about the efficacy of helicopter medical evacuation was erased during the Vietnam conflict. As an integral part of the modern battlefield, these specialized aircraft became a necessity. The observations and experience of American servicemen and medical personnel in Vietnam established the foundation for the acceptance of helicopter transport in modern hospital systems.

  10. Xenia: A Probe of Cosmic Chemical Evolution

    Science.gov (United States)

    Kouveliotou, Chryssa; Piro, L.; Xenia Collaboration

    2008-03-01

    Xenia is a concept study for a medium-size astrophysical cosmology mission addressing the Cosmic Origins key objective of NASA's Science Plan. The fundamental goal of this objective is to understand the formation and evolution of structures on various scales from the early Universe to the present time (stars, galaxies and the cosmic web). Xenia will use X-and γ-ray monitoring and wide field X-ray imaging and high-resolution spectroscopy to collect essential information from three major tracers of these cosmic structures: the Warm Hot Intergalactic Medium (WHIM), Galaxy Clusters and Gamma Ray Bursts (GRBs). Our goal is to trace the chemo-dynamical history of the ubiquitous warm hot diffuse baryon component in the Universe residing in cosmic filaments and clusters of galaxies up to its formation epoch (at z =0-2) and to map star formation and galaxy metal enrichment into the re-ionization era beyond z 6. The concept of Xenia (Greek for "hospitality") evolved in parallel with the Explorer of Diffuse Emission and GRB Explosions (EDGE), a mission proposed by a multinational collaboration to the ESA Cosmic Vision 2015. Xenia incorporates the European and Japanese collaborators into a U.S. led mission that builds on the scientific objectives and technological readiness of EDGE.

  11. Xenia: A Probe of Cosmic Chemical Evolution

    Science.gov (United States)

    Kouveliotou, Chryssa; Piro, L.

    2008-01-01

    Xenia is a concept study for a medium-size astrophysical cosmology mission addressing the Cosmic Origins key objective of NASA's Science Plan. The fundamental goal of this objective is to understand the formation and evolution of structures on various scales from the early Universe to the present time (stars, galaxies and the cosmic web). Xenia will use X-and y-ray monitoring and wide field X-ray imaging and high-resolution spectroscopy to collect essential information from three major tracers of these cosmic structures: the Warm Hot Intergalactic Medium (WHIM), Galaxy Clusters and Gamma Ray Bursts (GRBs). Our goal is to trace the chemo-dynamical history of the ubiquitous warm hot diffuse baryon component in the Universe residing in cosmic filaments and clusters of galaxies up to its formation epoch (at z =0-2) and to map star formation and galaxy metal enrichment into the re-ionization era beyond z 6. The concept of Xenia (Greek for "hospitality") evolved in parallel with the Explorer of Diffuse Emission and GRB Explosions (EDGE), a mission proposed by a multinational collaboration to the ESA Cosmic Vision 2015. Xenia incorporates the European and Japanese collaborators into a U.S. led mission that builds on the scientific objectives and technological readiness of EDGE.

  12. Experiences and practices of evolution instructors at Christian universities that can inform culturally competent evolution education

    Science.gov (United States)

    Barnes, M. Elizabeth

    2017-01-01

    Abstract Students’ religious beliefs and religious cultures have been shown to be the main factors predicting whether they will accept evolution, yet college biology instructors teaching evolution at public institutions often have religious beliefs and cultures that are different from their religious students. This difference in religious beliefs and cultures may be a barrier to effective evolution education. To explore when evolution instructors have similar religious cultures and beliefs as their students, we interviewed 32 evolution instructors at Christian universities nationwide about their practices and experiences teaching evolution. Christian university instructors emphasized teaching for acceptance of evolution while holding an inclusive teaching philosophy that they perceived led to a safe environment for students. Additionally, almost all instructors reported using practices that have been shown to increase student acceptance of evolution and reduce student conflict between evolution and religion. Further, we found that these instructors perceived that their own religious backgrounds have guided their decisions to teach evolution to their students in a culturally competent way. We discuss how these data, combined with past research literature on public college instructors, indicate that cultural competence could be a useful new framework for promoting effective evolution education in higher education institutions. PMID:29398727

  13. Novel thin-GaN LED structure adopted micro abraded surface to compare with conventional vertical LEDs in ultraviolet light

    Science.gov (United States)

    Chiang, Yen Chih; Lin, Chien Chung; Kuo, Hao Chung

    2015-04-01

    In this study, novel thin-GaN-based ultraviolet light-emitting diodes (NTG-LEDs) were fabricated using wafer bonding, laser lift-off, dry etching, textured surface, and interconnection techniques. Placing PN electrodes on the same side minimized the absorption caused by electrodes in conventional vertical injection light-emitting diodes (V-LEDs) and the current spreading was improved. The light output power (700 mA) of the NTG-LEDs was enhanced by 18.3% compared with that of the V-LEDs, and the external quantum efficiency (EQE) of the NTG-LEDs was also relatively enhanced by 20.0% compared with that of a reference device. When the current operations were 1,500 mA, the enhancements of the light output power and EQE were 27.4% and 27.2%, respectively. Additionally, the efficiency droop was improved by more than 15% at the same current level.

  14. Effect of electrophotographic processes on print quality in LED printers

    Science.gov (United States)

    Wyhof, John R.

    1990-08-01

    The advantage of LED electrophotographic page printers is closely linked to the the process parameters of the printer. The electrical and mechanical processes and material properties were analyzed with respect to the affect on the print quality. Most critical to the print quality for the LED array printer is the constancy of the light intensity since the elements in the array are each independent light sources. It was found that the spot size can change significantly if the light intensity varies. Halftone printing uses the spot size to space size ratio to create the grayscale. The light intensity variation between elements can be 20 in non-compensated LED head arrays. If the need for light intensity compensation can be eliminated then a significant cost reduction in the LED head can be achieved. However the parameters of the basic electrophotographic processes must be carefully selected to assure a constant spot size and optimum print quality. The development method toner properties and the portion of the photoreceptor discharge curve used have the strongest influence on the spot size and halftone print quality. Transfer fusing and mechanical parameters have minimal effect. 1. LED PRINTING PROCESS The advantages of the LED printing process for high speed electrophotographic printers are well known. 1 Recently several printer manufacturers have introduced electrophotographic LED printers in the lower speed range. When compared to the scanning laser beam or liquid crystal

  15. Reliability test and failure analysis of high power LED packages

    Science.gov (United States)

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

    2011-01-01

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

  16. Spectral design flexibility of LED brings better life

    Science.gov (United States)

    Ou, Haiyan; Corell, Dennis; Ou, Yiyu; Poulsen, Peter B.; Dam-Hansen, Carsten; Petersen, Paul-Michael

    2012-03-01

    Light-emitting diodes (LEDs) are penetrating into the huge market of general lighting because they are energy saving and environmentally friendly. The big advantage of LED light sources, compared to traditional incandescent lamps and fluorescent light tubes, is the flexible spectral design to make white light using different color mixing schemes. The spectral design flexibility of white LED light sources will promote them for novel applications to improve the life quality of human beings. As an initial exploration to make use of the spectral design flexibility, we present an example: 'no blue' white LED light source for sufferers of disease Porphyria. An LED light source prototype, made of high brightness commercial LEDs applying an optical filter, was tested by a patient suffering from Porphyria. Preliminary results have shown that the sufferer could withstand the light source for much longer time than the standard light source. At last future perspectives on spectral design flexibility of LED light sources improving human being's life will be discussed, with focus on the light and health. The good health is ensured by the spectrum optimized so that vital hormones (melatonin and serotonin) are produced during times when they support human daily rhythm.

  17. [Study on the safety of blue light leak of LED].

    Science.gov (United States)

    Shen, Chong-Yu; Xu, Zheng; Zhao, Su-Ling; Huang, Qing-Yu

    2014-02-01

    In this paper, the blue light properties of LED illumination devices have been investigated. Against the status quo of China's LED lighting, we measured the spectrum component of LED lamps and analyzed the photobiological safety under the current domestic and international standards GB/T 20145-2006/CIE S009/E: 2002 and IEC62471: 2006 standards as well as CTL-0744_2009-laser resolution, which provides the reference to the manufacture of LED lighting lamps as well as related safety standards and laws. If the radiance intensity of blue light in LED is lower than 100 W x m(-2) x Sr(-1), there is no harm to human eyes. LEDs will not cause harm to human eyes under normal use, but we should pay attention to the protection of special populations (children), and make sure that they avoid looking at a light source for a long time. The research has found that the blue-rich lamps can affect the human rule of work and rest, and therefore, the LED lamps with color temperature below 4 000 K and color rendering index of 80 are suitable for indoor use. At the same time, the lamps with different parameters should be selected according to the different distances.

  18. Visual color matching system based on RGB LED light source

    Science.gov (United States)

    Sun, Lei; Huang, Qingmei; Feng, Chen; Li, Wei; Wang, Chaofeng

    2018-01-01

    In order to study the property and performance of LED as RGB primary color light sources on color mixture in visual psychophysical experiments, and to find out the difference between LED light source and traditional light source, a visual color matching experiment system based on LED light sources as RGB primary colors has been built. By simulating traditional experiment of metameric color matching in CIE 1931 RGB color system, it can be used for visual color matching experiments to obtain a set of the spectral tristimulus values which we often call color-matching functions (CMFs). This system consists of three parts: a monochromatic light part using blazed grating, a light mixing part where the summation of 3 LED illuminations are to be visually matched with a monochromatic illumination, and a visual observation part. The three narrow band LEDs used have dominant wavelengths of 640 nm (red), 522 nm (green) and 458 nm (blue) respectively and their intensities can be controlled independently. After the calibration of wavelength and luminance of LED sources with a spectrophotometer, a series of visual color matching experiments have been carried out by 5 observers. The results are compared with those from CIE 1931 RGB color system, and have been used to compute an average locus for the spectral colors in the color triangle, with white at the center. It has been shown that the use of LED is feasible and has the advantages of easy control, good stability and low cost.

  19. Vision communications based on LED array and imaging sensor

    Science.gov (United States)

    Yoo, Jong-Ho; Jung, Sung-Yoon

    2012-11-01

    In this paper, we propose a brand new communication concept, called as "vision communication" based on LED array and image sensor. This system consists of LED array as a transmitter and digital device which include image sensor such as CCD and CMOS as receiver. In order to transmit data, the proposed communication scheme simultaneously uses the digital image processing and optical wireless communication scheme. Therefore, the cognitive communication scheme is possible with the help of recognition techniques used in vision system. By increasing data rate, our scheme can use LED array consisting of several multi-spectral LEDs. Because arranged each LED can emit multi-spectral optical signal such as visible, infrared and ultraviolet light, the increase of data rate is possible similar to WDM and MIMO skills used in traditional optical and wireless communications. In addition, this multi-spectral capability also makes it possible to avoid the optical noises in communication environment. In our vision communication scheme, the data packet is composed of Sync. data and information data. Sync. data is used to detect the transmitter area and calibrate the distorted image snapshots obtained by image sensor. By making the optical rate of LED array be same with the frame rate (frames per second) of image sensor, we can decode the information data included in each image snapshot based on image processing and optical wireless communication techniques. Through experiment based on practical test bed system, we confirm the feasibility of the proposed vision communications based on LED array and image sensor.

  20. LED lamps in shipboard lighting systems: Aspects of electromagnetic compatibility

    Directory of Open Access Journals (Sweden)

    Beley V. F.

    2016-12-01

    Full Text Available Trends in the development of different types of light sources and their energy characteristics have been described in the paper. Analysis of regulatory documents has been given. The results of experimental studies of a number of modern LED lamps have been described. Investigation has been made for a number of LED lamps produced by Philips, Xavax and Melitec. The experimental data have been obtained with the complex of devices: the dual-channel oscilloscope (GDS-71042, the power quality analyzer (Fluke-434 and the multi-function device EcoLight-01 (light-, pulse- and luminance meter. It has been shown that operation of LED lamps is characterized by emission of higher current harmonics and reactive power consumption, which depends on the type and design of the lamp driver. It has been found that the value of luminance created by LED lamps in case of acceptable (for ships prolonged deviation of voltage (–10 % is reduced by 3 %; in case of permissible short-term voltage deviation (–20 % luminance is reduced by 7 %. For incandescent lamps this indicator is characterized by a decrease in luminance by 40 % and 60 %, respectively. Despite the low sensitivity to voltage changes (in comparison with other types of lamps, the operation of LED lamps is also associated with the appearance of flicker. Absence of limitations for fluctuations of the light flux in shipboard lighting systems and imperfection of methods for determining the flicker make it difficult to ensure electromagnetic compatibility of LED lamps. Therefore due to reliability, environmental friendliness, energy efficiency and lumen maintenance LED lamps have prospects for introduction into shipboard lighting systems. However, to ensure electromagnetic compatibility of LED lighting systems it is necessary to conduct a detailed study of energy characteristics of LED lamps and to develop appropriate regulatory requirements and technical solutions.