WorldWideScience

Sample records for led traditional storybook

  1. Children Develop Initial Orthographic Knowledge during Storybook Reading

    Science.gov (United States)

    Apel, Kenn; Brimo, Danielle; Wilson-Fowler, Elizabeth B.; Vorstius, Christian; Radach, Ralph

    2013-01-01

    We examined whether young children acquire orthographic knowledge during structured adult-led storybook reading even though minimal viewing time is devoted to print. Sixty-two kindergarten children were read 12 storybook "chapters" while their eye movements were tracked. Results indicated that the children quickly acquired initial mental…

  2. The Effect of Electronic Storybooks on Struggling Fourth-Graders' Reading Comprehension

    Science.gov (United States)

    Ertem, Ihsan Seyit

    2010-01-01

    This quantitative research examined the differences in struggling readers' comprehension of storybooks according to the medium of presentation. Each student was randomly assigned with one of three conditions: (1) computer presentation of storybooks with animation; (2) computer presentation of storybooks without animation; and (3) traditional print…

  3. Analysis of Technical Specifications of the Egyptian and French Electronic Storybooks (e-Storybook)

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    Atta, Mohammed Mahmoud; Abd El Wahab, Shaimaa Mahmoud

    2015-01-01

    This research aims at analysing technical specifications in a sample of Egyptian and French electronic storybooks (e-storybooks), to identify similarities and differences in technical specifications of children's e-storybooks and create a verified analysis list to be used for evaluation of e-storybooks. For this purpose, 32 e-storybooks in CD…

  4. Emotion displays in media: a comparison between American, Romanian, and Turkish children's storybooks.

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    Wege, Briana Vander; Sánchez González, Mayra L; Friedlmeier, Wolfgang; Mihalca, Linda M; Goodrich, Erica; Corapci, Feyza

    2014-01-01

    Children's books may provide an important resource of culturally appropriate emotions. This study investigates emotion displays in children's storybooks for preschoolers from Romania, Turkey, and the US in order to analyze cultural norms of emotions. We derived some hypotheses by referring to cross-cultural studies about emotion and emotion socialization. For such media analyses, the frequency rate of certain emotion displays can be seen as an indicator for the salience of the specific emotion. We expected that all children's storybooks would highlight dominantly positive emotions and that US children's storybooks would display negative powerful emotions (e.g., anger) more often and negative powerless emotions (e.g., sadness) less often than Turkish and Romanian storybooks. We also predicted that the positive and negative powerful emotion expressions would be more intense in the US storybooks compared to the other storybooks. Finally, we expected that social context (ingroup/outgroup) may affect the intensity emotion displays more in Turkish and Romanian storybooks compared to US storybooks. Illustrations in 30 popular children's storybooks (10 for each cultural group) were coded. Results mostly confirmed the hypotheses but also pointed to differences between Romanian and Turkish storybooks. Overall, the study supports the conclusion that culture-specific emotion norms are reflected in media to which young children are exposed.

  5. Emotion displays in media: a comparison between American, Romanian, and Turkish children's storybooks

    Science.gov (United States)

    Wege, Briana Vander; Sánchez González, Mayra L.; Friedlmeier, Wolfgang; Mihalca, Linda M.; Goodrich, Erica; Corapci, Feyza

    2014-01-01

    Children's books may provide an important resource of culturally appropriate emotions. This study investigates emotion displays in children's storybooks for preschoolers from Romania, Turkey, and the US in order to analyze cultural norms of emotions. We derived some hypotheses by referring to cross-cultural studies about emotion and emotion socialization. For such media analyses, the frequency rate of certain emotion displays can be seen as an indicator for the salience of the specific emotion. We expected that all children's storybooks would highlight dominantly positive emotions and that US children's storybooks would display negative powerful emotions (e.g., anger) more often and negative powerless emotions (e.g., sadness) less often than Turkish and Romanian storybooks. We also predicted that the positive and negative powerful emotion expressions would be more intense in the US storybooks compared to the other storybooks. Finally, we expected that social context (ingroup/outgroup) may affect the intensity emotion displays more in Turkish and Romanian storybooks compared to US storybooks. Illustrations in 30 popular children's storybooks (10 for each cultural group) were coded. Results mostly confirmed the hypotheses but also pointed to differences between Romanian and Turkish storybooks. Overall, the study supports the conclusion that culture-specific emotion norms are reflected in media to which young children are exposed. PMID:24987384

  6. Benefits and Pitfalls of Multimedia and Interactive Features in Technology-Enhanced Storybooks : A Meta-Analysis

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    Takacs, Zsofia K.; Swart, Elise K.; Bus, Adriana G

    2015-01-01

    A meta-analysis was conducted on the effects of technology-enhanced stories for young children's literacy development when compared to listening to stories in more traditional settings like storybook reading. A small but significant additional benefit of technology was found for story comprehension

  7. Emotion Displays in Media: A Comparison Between American, Romanian, and Turkish Children’s Storybooks

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    Wolfgang eFriedlmeier

    2014-06-01

    Full Text Available Children’s books may provide an important resource of culturally appropriate emotions. This study investigates emotion displays in children’s storybooks for preschoolers from Romania, Turkey, and the US in order to analyze cultural norms of emotions. We derived some hypotheses by referring to cross-cultural studies about emotion and emotion socialization. For such media analyses, the frequency rate of certain emotion displays can be seen as an indicator for the salience of the specific emotion. Therefore, we expected that all children’s storybooks would highlight dominantly positive emotions and that American children’s storybooks would display negative powerful emotions (e.g., anger more often and negative powerless emotions (e.g., sadness less often than Turkish and Romanian storybooks. We also predicted that the positive and negative powerful emotion expressions would be more intense in the American storybooks compared to the other storybooks. Finally, we expected that social context (ingroup/outgroup may affect the intensity emotion displays more in Turkish and Romanian storybooks compared to American storybooks. Illustrations in 30 popular children’s storybooks (10 for each cultural group were coded. Results mostly confirmed the hypotheses but also pointed to differences between Romanian and Turkish storybooks. Overall, the study supports the conclusion that culture-specific emotion norms are reflected in media to which young children are exposed.

  8. Benefits and Pitfalls of Multimedia and Interactive Features in Technology-Enhanced Storybooks: A Meta-Analysis

    Science.gov (United States)

    Takacs, Zsofia K.; Swart, Elise K.; Bus, Adriana G.

    2015-01-01

    A meta-analysis was conducted on the effects of technology-enhanced stories for young children's literacy development when compared to listening to stories in more traditional settings like storybook reading. A small but significant additional benefit of technology was found for story comprehension (g+ = 0.17) and expressive vocabulary (g+ =…

  9. Scaffolding or Distracting: CD-ROM Storybooks and Young Readers

    Science.gov (United States)

    Pearman, Cathy J.; Chang, Ching-Wen

    2010-01-01

    CD-ROM storybooks, often referred to as electronic texts, e-books, and interactive stories, are learning tools with supplemental features such as automatic reading of text, sound effects, word pronunciations, and graphic animations which support the development of reading skills and comprehension in beginning readers. Some CD-ROM storybooks also…

  10. Get the story straight: contextual repetition promotes word learning from storybooks

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    Jessica S Horst

    2011-02-01

    Full Text Available Although reading storybooks to preschool children is a common activity believed to improve language skills, how children learn new vocabulary from being to has been largely neglected in the shared storybook reading literature. The current study systematically explores the effects of repeatedly reading the same storybooks on both young children's fast and slow mapping ability. Specially created storybooks were read to 3-year-old children three times during the course of one week. Each of the nine storybooks contained two novel word-object pairs. At each session, children either heard three different stories with the same two novel name-object pairs or the same story three times. All children heard each novel name the same number of times. A four-alternative forced-choice task with pictures of the objects was used to test both immediate recall and retention. Children who heard the same stories repeatedly were very accurate on both the immediate recall and retention tasks. In contrast, children who heard different stories were only accurate on immediate recall during the last two sessions and failed to learn any of the new words. Overall, then, we found a dramatic increase in children’s ability to both recall and retain novel word-object associations encountered during shared storybook reading when they heard the same stories multiple times in succession. Results are discussed in terms of contextual cueing effects observed in other cognitive domains.

  11. Digital life storybooks for people with dementia living in care homes: an evaluation

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    Subramaniam P

    2016-09-01

    Full Text Available Ponnusamy Subramaniam,1 Bob Woods2 1Health Psychology Programme, University Kebangsaan Malaysia, Kuala Lumpur, Malaysia; 2Dementia Services Development Centre Wales, Bangor University, Bangor, Gwynedd, UK Background and aim: There is increasing interest in using information and communication technology to help older adults with dementia to engage in reminiscence work. Now, the feasibility of such approaches is beginning to be established. The purpose of this study was to establish an evidence-base for the acceptability and efficacy of using multimedia digital life storybooks with people with dementia in care homes, in comparison with conventional life storybooks, taking into account the perspectives of people with dementia, their relatives, and care staff.Methods: Participatory design was used to create a life story movie based on a previously completed conventional life storybook with six older adults with dementia (four females; mean age 82 years. Relatives were involved in helping the participant to provide additional information and materials for the digital life storybook. In this multiple case study design, both quantitative and qualitative approaches were used. For quantitative purposes, a set of questionnaires that had been completed three times before and after the conventional life storybook was developed were repeated 4 weeks after the life story movie was completed. Semistructured interview questions were designed to collect feedback from participants, relatives, and care staff.Results: The result indicated that five of the six participants showed additional improvement in measures of quality of life and autobiographical memory. All participants showed improvement or stability in depression scores. Thematic analysis showed that, participants, relatives, and care home staff viewed digital life storybooks as a very useful tool triggering memories and (largely positive emotions. Participants’ case vignettes were presented to

  12. Learning what feelings to desire: socialization of ideal affect through children's storybooks.

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    Tsai, Jeanne L; Louie, Jennifer Y; Chen, Eva E; Uchida, Yukiko

    2007-01-01

    Previous findings suggest that cultural factors influence ideal affect (i.e., the affective states that people ideally want to feel). Three studies tested the hypothesis that cultural differences in ideal affect emerge early in life and are acquired through exposure to storybooks. In Study 1, the authors established that consistent with previous findings, European American preschoolers preferred excited (vs. calm) states more (indexed by activity and smile preferences) and perceived excited (vs. calm) states as happier than Taiwanese Chinese preschoolers. In Study 2, it was observed that similar differences were reflected in the pictures (activities, expressions, and smiles) of best-selling storybooks in the United States and Taiwan. Study 3 found that across cultures, exposure to exciting (vs. calm) storybooks altered children's preferences for excited (vs. calm) activities and their perceptions of happiness. These findings suggest that cultural differences in ideal affect may be due partly to differential exposure to calm and exciting storybooks.

  13. Infant-Parent Attachment and Parental and Child Behavior during Parent-Toddler Storybook Interaction.

    Science.gov (United States)

    Frosch, Cynthia A.; Cox, Martha J.; Goldman, Barbara Davis

    2001-01-01

    Examined longitudinal associations between infant-parent attachment and parent/toddler behavior during storybook interaction. Found that infants with insecure-resistant attachment with mothers were less enthusiastic and focused during storybook interaction at 24 months. Mothers of insecure-resistant infants were less warm/supportive, and less…

  14. Multimedia Storybooks: Supporting Vocabulary for Students Who Are Deaf/Hard-of-Hearing

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    Donne, Vicki; Briley, Margaret L.

    2015-01-01

    A single case study examined the use of multimedia storybooks on the vocabulary acquisition of 7 preschool students who are deaf/hard of hearing in two classrooms at a school for the deaf in the U.S. Participants also included 3 speech-language pathologists. Students spent an average of 7.1 minutes daily working with the multimedia storybooks and…

  15. Design of Multimedia-based Digital Storybooks for Preschool Education

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    Didik Dwi Prasetya

    2018-02-01

    Full Text Available Storytelling is one of the suitable approaches to deliver the right information and build the character education of young children. The story content presented by utilizing multimedia elements is able to offer more attractive and increase interest for children. This paper proposes an ICT approach through multimedia-based digital storybook design with an EPUB reflowable format that can be accessed using various electronic devices, whether desktop, laptop, or mobile. The research subjects are limited to 4-5-year-old preschool children. The research reveals that children were very enthusiastic about storybooks, with or without supports from teachers

  16. Live Storybook Outcomes of Pilot Multidisciplinary Elementary Earth Science Collaborative Project

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    Soeffing, C.; Pierson, R.

    2017-12-01

    Live Storybook Outcomes of pilot multidisciplinary elementary earth science collaborative project Anchoring phenomena leading to student led investigations are key to applying the NGSS standards in the classroom. This project employs the GLOBE elementary storybook, Discoveries at Willow Creek, as an inspiration and operational framework for a collaborative pilot project engaging 4th grade students in asking questions, collecting relevant data, and using analytical tools to document and understand natural phenomena. The Institute of Global Environmental Strategies (IGES), a GLOBE Partner, the Outdoor Campus, an informal educational outdoor learning facility managed by South Dakota Game, Fish and Parks, University of Sioux Falls, and All City Elementary, Sioux Falls are collaborating partners in this project. The Discoveries at Willow Creek storyline introduces young students to the scientific process, and models how they can apply science and engineering practices (SEPs) to discover and understand the Earth system in which they live. One innovation associated with this project is the formal engagement of elementary students in a global citizen science program (for all ages), GLOBE Observer, and engaging them in data collection using GLOBE Observer's Cloud and Mosquito Habitat Mapper apps. As modeled by the fictional students from Willow Creek, the 4th grade students will identify their 3 study sites at the Outdoor Campus, keep a journal, and record observations. The students will repeat their investigations at the Outdoor Campus to document and track change over time. Students will be introduced to "big data" in a manageable way, as they see their observations populate GLOBE's map-based data visualization and . Our research design recognizes the comfort and familiarity factor of literacy activities in the elementary classroom for students and teachers alike, and postulates that connecting a science education project to an engaging storybook text will contribute to a

  17. Preschoolers Explore Interactive Storybook Apps: The Effect on Word Recognition and Story Comprehension

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    Zipke, Marcy

    2017-01-01

    Two experiments explored the effects of reading digital storybooks on tablet computers with 25 preschoolers, aged 4-5. In the first experiment, the students' word recognition scores were found to increase significantly more when students explored a digital storybook and employed the read-aloud function than when they were read to from a comparable…

  18. Reading touch screen storybooks with mothers negatively affects seven-year-old readers’ comprehension but enriches emotional engagement

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    Kirsty Mhairi Ross

    2016-11-01

    Full Text Available Touch screen storybooks turn reading into an interactive multimedia experience, with hotspot-activated animations, sound effects, and games. Positive and negative effects of reading multimedia stories have been reported, but the underlying mechanisms which explain how children’s learning is affected remain uncertain. The present study examined the effect of storybook format (touch screen and print on story comprehension, and considered how level of touch screen interactivity (high and low and shared reading behaviors (cognitive and emotional scaffolding, emotional engagement might contribute to comprehension. Seven-year-olds (n = 22 were observed reading one touch screen storybook and one print storybook with their mothers. Story comprehension was inferior for the touch screen storybooks compared to the print versions. Touch screen interactivity had no significant effect on comprehension but did affect shared reading behaviors. The mother-child dyads spent less time talking about the story in the highly interactive touch screen condition, despite longer shared reading sessions because of touch screen interactions. Positive emotional engagement was greater for children and mothers in the highly interactive touch screen condition, due to additional positive emotions expressed during touch screen interactions. Negative emotional engagement was greater for children when reading and talking about the story in the highly interactive condition, and some mothers demonstrated negative emotional engagement with the touch screen activities. The less interactive touch screen storybook had little effect on shared reading behaviors, but mothers controlling behaviors were more frequent. Storybook format had no effect on the frequency of mothers’ cognitive scaffolding behaviors (comprehension questions, word help. Relationships between comprehension and shared reading behaviors were examined for each storybook, and length of the shared reading session and

  19. Reading Touch Screen Storybooks with Mothers Negatively Affects 7-Year-Old Readers’ Comprehension but Enriches Emotional Engagement

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    Ross, Kirsty M.; Pye, Rachel E.; Randell, Jordan

    2016-01-01

    Touch screen storybooks turn reading into an interactive multimedia experience, with hotspot-activated animations, sound effects, and games. Positive and negative effects of reading multimedia stories have been reported, but the underlying mechanisms which explain how children’s learning is affected remain uncertain. The present study examined the effect of storybook format (touch screen and print) on story comprehension, and considered how level of touch screen interactivity (high and low) and shared reading behaviors (cognitive and emotional scaffolding, emotional engagement) might contribute to comprehension. Seven-year-olds (n = 22) were observed reading one touch screen storybook and one print storybook with their mothers. Story comprehension was inferior for the touch screen storybooks compared to the print formats. Touch screen interactivity level had no significant effect on comprehension but did affect shared reading behaviors. The mother–child dyads spent less time talking about the story in the highly interactive touch screen condition, despite longer shared reading sessions because of touch screen interactions. Positive emotional engagement was greater for children and mothers in the highly interactive touch screen condition, due to additional positive emotions expressed during touch screen interactions. Negative emotional engagement was greater for children when reading and talking about the story in the highly interactive condition, and some mothers demonstrated negative emotional engagement with the touch screen activities. The less interactive touch screen storybook had little effect on shared reading behaviors, but mothers controlling behaviors were more frequent. Storybook format had no effect on the frequency of mothers’ cognitive scaffolding behaviors (comprehension questions, word help). Relationships between comprehension and shared reading behaviors were examined for each storybook, and although length of the shared reading session and

  20. Measuring theory of mind in children. Psychometric properties of the ToM Storybooks.

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    Blijd-Hoogewys, E M A; van Geert, P L C; Serra, M; Minderaa, R B

    2008-11-01

    Although research on Theory-of-Mind (ToM) is often based on single task measurements, more comprehensive instruments result in a better understanding of ToM development. The ToM Storybooks is a new instrument measuring basic ToM-functioning and associated aspects. There are 34 tasks, tapping various emotions, beliefs, desires and mental-physical distinctions. Four studies on the validity and reliability of the test are presented, in typically developing children (n = 324, 3-12 years) and children with PDD-NOS (n = 30). The ToM Storybooks have good psychometric qualities. A component analysis reveals five components corresponding with the underlying theoretical constructs. The internal consistency, test-retest reliability, inter-rater reliability, construct validity and convergent validity are good. The ToM Storybooks can be used in research as well as in clinical settings.

  1. Teaching children road safety through storybooks: an approach to child health literacy in Pakistan.

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    Ahmad, Haris; Naeem, Rubaba; Feroze, Asher; Zia, Nukhba; Shakoor, Amarah; Khan, Uzma Rahim; Mian, Asad Iqbal

    2018-02-07

    Road traffic injuries (RTIs) commonly affect the younger population in low- and-middle-income countries. School children may be educated about road safety using storybooks with colorful pictures, which tends to increase the child's interest in the text. Therefore, this study assessed the use of bilingual pictorial storybooks to improve RTI prevention knowledge among school children. This pretest-posttest study was conducted in eight public and nine private schools of Karachi, Pakistan, between February to May 2015. Children in grades four and five were enrolled at baseline (n = 410). The intervention was an interactive discussion about RTI prevention using a bilingual (Urdu and English) pictorial storybook. A baseline test was conducted to assess children's pre-existing knowledge about RTI prevention followed by administration of the intervention. Two posttests were conducted: first immediately after the intervention, and second after 2 months. Test scores were analyzed using McNemar test and paired sample t-test. There were 57% girls and 55% public school students; age range 8-16 years. Compared to the overall baseline score (5.1 ± 1.4), the number of correct answers increased in both subsequent tests (5.9 ± 1.2 and 6.1 ± 1.1 respectively, p-value education sessions may be incorporated into school curricula using storybooks as teaching tools. Potential exists to create similar models for other developing countries by translating the storybooks into local languages.

  2. Think Scientifically: Science Hidden in a Storybook

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    Van Norden, W. M.

    2012-12-01

    The Solar Dynamics Observatory's Think Scientifically (TS) program links literacy and science in the elementary classroom through an engaging storybook format and hands-on, inquiry based activities. TS consists of three illustrated storybooks, each addressing a different solar science concept. Accompanying each book is a hands-on science lesson plan that emphasizes the concepts addressed in the book, as well as math, reading, and language arts activities. Written by teachers, the books are designed to be extremely user-friendly and easy to implement in classroom instruction. The objectives of the program are: (1) to increase time spent on science in elementary school classrooms, (2) to assist educators in implementing hands-on science activities that reinforce concepts from the book, (3) to increase teacher capacity and comfort in teaching solar concepts, (4) to increase student awareness and interest in solar topics, especially students in under-served and under-represented communities. Our program meets these objectives through the National Science Standards-based content delivered in each story, the activities provided in the books, and the accompanying training that teachers are offered through the program.; ;

  3. Joint storybook reading measured with children's book title checklist and the children's language development in early childhood

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    Katja Bajc

    2005-09-01

    Full Text Available In the present study we examined the relationship between parental educational level, joint storybook reading and children's language competence. Our sample included 123 5-year-old children attending one of the Slovenian preschools. Frequency of parent-child joint storybook reading was measured indirectly with the children's book title checklist, which was used in the Slovenian language environment for the first time, and which, in comparison with the parents' report about how often they read to their children, represents a more objective measure of storybook exposure. By using checklist we avoid socially desirable responses, which parents give because they think that reading is important for children's language development. We found out that parental education is positively related to the parental familiarity with the titles of books for children. Furthermore, the results show that storybook exposure is, regardless of parental educational level, a factor of home environment which makes an important contribution to the development of children's language competence.

  4. Interactive electronic storybooks for kindergartners to promote vocabulary growth

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    Smeets, Daisy J. H.; Bus, Adriana G

    2012-01-01

    The goals of this study were to examine (a) whether extratextual vocabulary instructions embedded in electronic storybooks facilitated word learning over reading alone and (b) whether instructional formats that required children to invest more effort were more effective than formats that required

  5. Storybook app creation demystified a cast study

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    Friedlander, Amy

    2013-01-01

    This case study explains how Wasabi Productions created its first app, Lazy Larry Lizard, and provides insight into the development of soon-to-be-released app, Gorilla Band. Inside, you will find notes on how storybook apps are produced from start to finish, including costs, production process, people, technology, pricing, release cycle, marketing and more. You will also find insights on technology, storyboard development and pricing.

  6. Who believes in the storybook image of the scientist?

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    Veldkamp, C.L S; Hartgerink, C.H.J.; van Assen, M.A.L.M.; Wicherts, J.M.

    2017-01-01

    Do lay people and scientists themselves recognize that scientists are human and therefore prone to human fallibilities such as error, bias, and even dishonesty? In a series of three experimental studies and one correlational study (total N = 3,278) we found that the 'storybook image of the

  7. Goodnight Book: Sleep Consolidation Improves Word Learning via Storybooks

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    Sophie E. Williams

    2014-03-01

    Full Text Available Reading the same storybooks repeatedly helps preschool children learn words. In addition, sleeping shortly after learning also facilitates memory consolidation and aids learning in older children and adults. The current study explored how sleep promotes word learning in preschool children using a shared storybook reading task. Children were either read the same story repeatedly or different stories and either napped after the stories or remained awake. Children’s word retention were tested 2.5 hours later, 24 hours later and 7 days later. Results demonstrate strong, persistent effects for both repeated readings and sleep consolidation on young children’s word learning. A key finding is that children who read different stories before napping learned words as well as children who had the advantage of hearing the same story. In contrast, children who read different stories and remained awake never caught up to their peers on later word learning tests. Implications for educational practices are discussed.

  8. Benefits and Pitfalls of Multimedia and Interactive Features in Technology-Enhanced Storybooks

    Science.gov (United States)

    Takacs, Zsofia K.; Swart, Elise K.; Bus, Adriana G.

    2015-01-01

    A meta-analysis was conducted on the effects of technology-enhanced stories for young children’s literacy development when compared to listening to stories in more traditional settings like storybook reading. A small but significant additional benefit of technology was found for story comprehension (g+ = 0.17) and expressive vocabulary (g+ = 0.20), based on data from 2,147 children in 43 studies. When investigating the different characteristics of technology-enhanced stories, multimedia features like animated pictures, music, and sound effects were found beneficial. In contrast, interactive elements like hotspots, games, and dictionaries were found to be distracting. Especially for children disadvantaged because of less stimulating family environments, multimedia features were helpful and interactive features were detrimental. Findings are discussed from the perspective of cognitive processing theories. PMID:26640299

  9. Who Believes in the Storybook Image of the Scientist?

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    Veldkamp, Coosje L S; Hartgerink, Chris H J; van Assen, Marcel A.L.M.; Wicherts, Jelte M.

    2017-01-01

    Do lay people and scientists themselves recognize that scientists are human and therefore prone to human fallibilities such as error, bias, and even dishonesty? In a series of three experimental studies and one correlational study (total N = 3,278) we found that the “storybook image of the

  10. Perfect Prophets, Helpful Hippos, and Happy Endings: Noah and Jonah in Children's Bible Storybooks in the United States

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    Dalton, Russell W.

    2007-01-01

    This article is based on a study of hundreds of children's bible storybooks available in the United States from 1850 to the present and focuses on the way the biblical stories of Noah and Jonah have been retold for children. These children's bible storybooks lend insight into the American church's changing assumptions about the purpose of the…

  11. The use of Julia Donaldson’s storybooks as an incentive to actively acquire foreign language in the 1st grade of primary school

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    Stošič, Ana

    2017-01-01

    Learning foreign languages in early childhood is very specific, therefore, teaching must take place according to certain principles. The acquisition of a foreign language should happen through games and movement activities. Moreover, the purpose of learning and teaching a foreign language in the first grade is also to encourage a positive attitude towards other languages. Storybooks are classified as basic teaching means or materials and storytelling is a traditional, tested (from folk litera...

  12. Benefits and Pitfalls of Multimedia and Interactive Features in Technology-Enhanced Storybooks: A Meta-Analysis.

    Science.gov (United States)

    Takacs, Zsofia K; Swart, Elise K; Bus, Adriana G

    2015-12-01

    A meta-analysis was conducted on the effects of technology-enhanced stories for young children's literacy development when compared to listening to stories in more traditional settings like storybook reading. A small but significant additional benefit of technology was found for story comprehension (g+ = 0.17) and expressive vocabulary (g+ = 0.20), based on data from 2,147 children in 43 studies. When investigating the different characteristics of technology-enhanced stories, multimedia features like animated pictures, music, and sound effects were found beneficial. In contrast, interactive elements like hotspots, games, and dictionaries were found to be distracting. Especially for children disadvantaged because of less stimulating family environments, multimedia features were helpful and interactive features were detrimental. Findings are discussed from the perspective of cognitive processing theories.

  13. The African Storybook and Language Teacher Identity in Digital Times

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    Stranger--Johannessen, Espen; Norton, Bonny

    2017-01-01

    The African Storybook (ASb) is a digital initiative that promotes multilingual literacy for African children by providing openly licenced children's stories in multiple African languages, as well as English, French, and Portuguese. Based on Darvin and Norton's (2015) model of identity and investment, and drawing on the Douglas Fir Group's (2016)…

  14. Improving Grade One Students' Reading Motivation with Online Electronic Storybooks

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    Ciampa, Katia

    2012-01-01

    This qualitative study stemmed from a concern of the perceived decline in students' reading motivation after the early years of schooling. The current research explored eight grade 1 students' experiences with online electronic storybooks (eBooks). Eight students were given ten 25-minute sessions with the software programs over 15 weeks.…

  15. Exploring Children's Picture Storybooks with Adult and Adolescent EFL Learners

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    Malu, Kathleen F.

    2013-01-01

    This article presents a theoretical framework to support the use of children's picture storybooks in teaching EFL to adults and adolescents. The author presents ways to use these books, addresses the twin goals of teaching mechanics and culture, and includes a list of books and a wide variety of activities that EFL teachers can use to effectively…

  16. A Joint Interactive Storybook Intervention Program for Preschool and Kindergarten Children

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    Vaknin-Nusbaum, Vered; Nevo, Einat

    2017-01-01

    The effectiveness of a joint interactive storybook reading program delivered by class teachers to develop literacy skills is examined in Hebrew-speaking preschool and kindergarten children. Post-intervention, both groups achieved significantly higher gains in language and print concept skills than age-matched comparison groups that did not have…

  17. Young children can be taught basic natural selection using a picture-storybook intervention.

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    Kelemen, Deborah; Emmons, Natalie A; Seston Schillaci, Rebecca; Ganea, Patricia A

    2014-04-01

    Adaptation by natural selection is a core mechanism of evolution. It is also one of the most widely misunderstood scientific processes. Misconceptions are rooted in cognitive biases found in preschoolers, yet concerns about complexity mean that adaptation by natural selection is generally not comprehensively taught until adolescence. This is long after untutored theoretical misunderstandings are likely to have become entrenched. In a novel approach, we explored 5- to 8-year-olds' capacities to learn a basic but theoretically coherent mechanistic explanation of adaptation through a custom storybook intervention. Experiment 1 showed that children understood the population-based logic of natural selection and also generalized it. Furthermore, learning endured 3 months later. Experiment 2 replicated these results and showed that children understood and applied an even more nuanced mechanistic causal explanation. The findings demonstrate that, contrary to conventional educational wisdom, basic natural selection is teachable in early childhood. Theory-driven interventions using picture storybooks with rich explanatory structure are beneficial.

  18. Measuring Theory of Mind in Children. Psychometric Properties of the ToM Storybooks

    NARCIS (Netherlands)

    Blijd-Hoogewys, E. M. A.; van Geert, P. L. C.; Serra, M.; Minderaa, R. B.

    Although research on Theory-of-Mind (ToM) is often based on single task measurements, more comprehensive instruments result in a better understanding of ToM development. The ToM Storybooks is a new instrument measuring basic ToM-functioning and associated aspects. There are 34 tasks, tapping various

  19. Year 5 Pupils Reading an "Interactive Storybook" on CD-ROM: Losing the Plot?

    Science.gov (United States)

    Trushell, John; Burrell, Clare; Maitland, Amanda

    2001-01-01

    This study examined whether small groups of grade 5 students in a London primary school, without teacher supervision, progressed linearly through an interactive storybook on CD-ROM, and whether such diversions as cued animations affected pupil comprehension. Results showed students' recall of the storyline was poor. (Author/LRW)

  20. Measuring Theory of Mind in Children. Psychometric Properties of the ToM Storybooks

    NARCIS (Netherlands)

    Blijd-Hoogewys, E. M. A.; van Geert, P. L. C.; Serra, M.; Minderaa, R. B.

    2008-01-01

    Although research on Theory-of-Mind (ToM) is often based on single task measurements, more comprehensive instruments result in a better understanding of ToM development. The ToM Storybooks is a new instrument measuring basic ToM-functioning and associated aspects. There are 34 tasks, tapping various

  1. Using electronic storybooks to support word learning in children with severe language impairments

    NARCIS (Netherlands)

    Smeets, Daisy J. H.; van Dijken, Marianne J.; Bus, Adriana G

    2012-01-01

    Novel word learning is reported to be problematic for children with severe language impairments (SLI). In this study, we tested electronic storybooks as a tool to support vocabulary acquisition in SLI children. In Experiment 1, 29 kindergarten SLI children heard four e-books each four times: (a) two

  2. Four Year Old Children's Acquisition of Print Knowledge during Electronic Storybook Reading

    Science.gov (United States)

    Gong, Zhiyu; Levy, Betty Ann

    2009-01-01

    The experiment reported here explored the importance of engaging 4-year-old children's interest in the print itself during storybook reading. We explored the effect of computer animation of the print in order to draw the child's attention to each word as it was read. We also investigated the influence of illustrating that not all visual displays…

  3. The impact of reading expressiveness on the listening comprehension of storybooks by prekindergarten children.

    Science.gov (United States)

    Mira, William A; Schwanenflugel, Paula J

    2013-04-01

    The purpose of this study was to determine the effect of oral reading expressiveness on the comprehension of storybooks by 4- and 5-year-old prekindergarten children. The possible impact of prosody on listening comprehension was explored. Ninety-two prekindergarten children (M age = 57.26 months, SD = 3.89 months) listened to an expressive or inexpressive recording of 1 of 2 similar stories. Story comprehension was tested using assessments of both free recall and cued recall. Children showed statistically significantly better cued recall for the expressive readings of stories compared to the inexpressive readings of stories. This effect generalized across stories and when story length was controlled across both expressive and inexpressive versions. The effect of expressiveness on children's free recall was not significant. Highly expressive readings resulted in better comprehension of storybooks by prekindergarten children. Further, because recordings were used, this effect might be attributed to the facilitation of language processing rather than to enhanced social interaction between the reader and the child.

  4. The Importance of Storybook Reading to Emergent Literacy: A Review of the Research.

    Science.gov (United States)

    McCarthy, Rae Lynn

    Educators have known for years that children who come from homes where storybooks are read have an advantage over those children who are not read to. Research has shown that shared reading, reading aloud, making a variety of print materials available, and promoting positive attitudes toward literacy have a significant impact on children's literacy…

  5. "Este Libro Es Mi Historia": Mother-Child Interactions during Storybook Reading in a Mexican-American Household.

    Science.gov (United States)

    Manyak, Patrick

    A study explored the storybook reading experiences between Ms. Garza and her children. A broad conception of the zone of proximal development, involving use, adaptation, and transformation of culturally shaped tools in the process of shared activity, provides the framework for examining this particular Mexican-American family's reading behavior.…

  6. A Read-Aloud Storybook Selection System for Prereaders at the Preschool Language Level: A Pilot Study

    Science.gov (United States)

    Schwarz, Amy Louise; van Kleeck, Anne; Beaton, Derek; Horne, Erin; MacKenzie, Heather; Abdi, Hervé

    2015-01-01

    Purpose: Many well-accepted systems for determining difficulty level exist for books children read independently, but few are available for determining the wide range of difficulty levels of storybooks read aloud to preschoolers. Also, the available tools list book characteristics only on the basis of parents' or authors' opinions. We created an…

  7. Comparison of an interactive CD-based and traditional instructor-led Basic Life Support skills training for nurses.

    Science.gov (United States)

    Mardegan, Karen J; Schofield, Margot J; Murphy, Gregory C

    2015-08-01

    Basic Life Support (BLS) is a life-saving and fundamental skill in resuscitation. However, studies have reported limitations in BLS training outcomes for both health professional and lay populations, and noted the resource and time-intensive nature of traditional training approaches. This exploratory study evaluated the effectiveness of an interactive CD-based BLS training programme that included unsupervised manikin practice compared with a traditional instructor-led BLS training programme involving demonstration and supervised practice. A quasi-experimental post-test with follow-up design was used. The sample was comprised of two cohorts: Novice second-year undergraduate Nursing students (n=187) and Practising Nurses (n=107) in their first year of hospital employment. BLS skill outcomes were assessed at one week and again at eight weeks post training. No statistically significant differences were found between the CD and traditional instructor-led BLS training methods in BLS skills of Novice and Practising Nurses at one week and eight weeks post training. However, there was a decrement in skill between one week and eight weeks post-training across both groups and an overall low level of competence. The failure to find a difference between the CD-based BLS programme with unsupervised manikin practice and a resource-intensive traditional instructor-led BLS training programme may indicate equivalence of the programmes or, even study design limitations. It is concerning that competence displayed by trainees from both groups was less than optimal and suggests the need for renewed efforts to develop and evaluate BLS training programmes which can achieve high rates of competence with acceptable skill retention over time. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  8. Factorial structure of the 'ToM Storybooks': A test evaluating multiple components of Theory of Mind.

    Science.gov (United States)

    Bulgarelli, Daniela; Testa, Silvia; Molina, Paola

    2015-06-01

    This study examined the factorial structure of the Theory of Mind (ToM) Storybooks, a comprehensive 93-item instrument tapping the five components in Wellman's model of ToM (emotion recognition, understanding of desire and beliefs, ability to distinguish between physical and mental entities, and awareness of the link between perception and knowledge). A sample of 681 three- to eight-year-old Italian children was divided into three age groups to assess whether factorial structure varied across different age ranges. Partial credit model analysis was applied to the data, leading to the empirical identification of 23 composite variables aggregating the ToM Storybooks items. Confirmatory factor analysis was then conducted on the composite variables, providing support for the theoretical model. There were partial differences in the specific composite variables making up the dimensions for each of the three age groups. A single test evaluating distinct dimensions of ToM is a valuable resource for clinical practice which may be used to define differential profiles for specific populations. © 2014 The British Psychological Society.

  9. Using electronic storybooks to support word learning in children with severe language impairments.

    Science.gov (United States)

    Smeets, Daisy J H; van Dijken, Marianne J; Bus, Adriana G

    2014-01-01

    Novel word learning is reported to be problematic for children with severe language impairments (SLI). In this study, we tested electronic storybooks as a tool to support vocabulary acquisition in SLI children. In Experiment 1, 29 kindergarten SLI children heard four e-books each four times: (a) two stories were presented as video books with motion pictures, music, and sounds, and (b) two stories included only static illustrations without music or sounds. Two other stories served as the control condition. Both static and video books were effective in increasing knowledge of unknown words, but static books were most effective. Experiment 2 was designed to examine which elements in video books interfere with word learning: video images or music or sounds. A total of 23 kindergarten SLI children heard 8 storybooks each four times: (a) two static stories without music or sounds, (b) two static stories with music or sounds, (c) two video stories without music or sounds, and (d) two video books with music or sounds. Video images and static illustrations were equally effective, but the presence of music or sounds moderated word learning. In children with severe SLI, background music interfered with learning. Problems with speech perception in noisy conditions may be an underlying factor of SLI and should be considered in selecting teaching aids and learning environments. © Hammill Institute on Disabilities 2012.

  10. Effects of a Cross-Linguistic Storybook Intervention on the Second Language Development of Two Preschool English Language Learners

    Science.gov (United States)

    Huennekens, Mary Ellen; Xu, Yaoying

    2010-01-01

    The purpose of this study was to examine the effects of a shared reading experience between parent and child in the child's home language on the emergent literacy and language acquisition in English of preschool-age English Language Learners. Parents of Spanish-speaking four-year-old Head Start students read storybooks in Spanish with their…

  11. Perceived learning effectiveness of a course Facebook page: teacher-led versus student-led approach

    Directory of Open Access Journals (Sweden)

    Tugba Orten Tugrul

    2017-01-01

    Full Text Available This research aims to compare the perceived effectiveness of teacher -led and student-led content management approaches embraced in a course Facebook page designed to enhance traditional classroom learning. Eighty-five undergraduate marketing course students voluntarily completed a questionnaire composed of two parts; a depiction of a course Facebook page where both teacher and students can share instructional contents, and questions about perceived learning effectiveness. The findings indicate that students have more favorable evaluations of a student-led approach in sharing instructional contents on a course Facebook Page than a teacher-led approach. Additionally, it is shown that instructional contents posted by both teacher and students enhance the overall learning effectiveness of a course Facebook page incorporated into a traditional classroom teaching.

  12. Rhyme and Word Placement in Storybooks Support High-Level Verb Mapping in 3- to 5-Year-Olds

    Directory of Open Access Journals (Sweden)

    Kirsten Read

    2018-06-01

    Full Text Available High-level verbs can be especially challenging for young children to initially map to meaning. This study manipulated the format of a storybook designed to support such verb learning from shared reading. We tested whether 3- to 5-year-olds (n = 38 could remember the referents of eight new verbs when presented as essential actions within a narrative story but with differences in placement. Children were randomly assigned to either a rhymed condition, in which target verbs were heard at the end of rhyming stanzas making them maximally appreciable, or a control condition, where the verbs were presented in the same story, but not in final position or within a rhymed stanza. After hearing the story, each child was given three sets of retention questions testing their identification, demonstration, and production of the target verbs. Children identified and successfully demonstrated more target verbs in the rhymed condition than the control condition, and only in the rhymed condition did children’s initial verb mappings exceed chance. No differences between conditions were found in children’s ability to produce the target verbs, in part because of how often they reverted to more generic terms to describe the actions in the story. Nonetheless, these findings support the hypothesis that giving children maximal support within a storybook reading context can facilitate an initial grasp on challenging verbs.

  13. THE EFFECTIVENESS OF USING PHONICS INSTRUCTION AND STORYBOOKS IN ENGLISH READING CLASSES TO IMPROVE STUDENT PARTICIPATION

    Directory of Open Access Journals (Sweden)

    Naning Tri Wahyuni

    2016-08-01

    Full Text Available The purpose of this study is to examine the effectiveness of instructional methods based on phonics instruction in reading classes to improve students participation therefore they can develop to their maximum potential. Using qualitative tools of observation, documentation and interview, this research was focusing the inquiry on investigating students’ reception to the phonics instruction model, observing their participation in the classroom activities, also investigating instructional methods which attract students to more actively contribute in learning activities. The finding shows that the reception of students to the model was good and they showed much eagerness in following the program. Further investigation revealed that students keen to participate more in the classroom activities especially in certain activities with the use of sound sheets, sound book, flash card sheets, word box sheets, songs, games and storybooks. However, there were two challenges identified during 16 weeks running the study; the lack of teachers’ skill in delivering this method efficiently also the limited collection of English story books in school. Hence, to improve the effectiveness of the use of phonics instruction in reading classroom, firstly, training for teachers would be needed to deliver the method effectively, secondly, considering the fact that school still have limited collection of English story books or any English books, the collaboration with government agencies or other promising bodies could be done to help in providing more collection of storybooks in school.

  14. Cathedral outreach: student-led workshops for school curriculum enhancement in non-traditional environments

    Science.gov (United States)

    Posner, Matthew T.; Jantzen, Alexander; van Putten, Lieke D.; Ravagli, Andrea; Donko, Andrei L.; Soper, Nathan; Wong, Nicholas H. L.; John, Pearl V.

    2017-08-01

    Universities in the United Kingdom have been driven to work with a larger pool of potential students than just the more traditional student (middle-class white male), in order to tackle the widely-accepted skills-shortage in the fields of science, technology, engineering and mathematics (STEM), whilst honoring their commitment to fair access to higher education. Student-led outreach programs have contributed significantly to this drive. Two such programs run by postgraduate students at the University of Southampton are the Lightwave Roadshow and Southampton Accelerate!, which focus on photonics and particle physics, respectively. The program ambassadors have developed activities to enhance areas of the national curriculum through presenting fundamental physical sciences and their applications to optics and photonics research. The activities have benefitted significantly from investment from international organizations, such as SPIE, OSA and the IEEE Photonics Society, and UK research councils, in conjunction with university recruitment and outreach strategies. New partnerships have been formed to expand outreach programs to work in non-traditional environments to challenge stereotypes of scientists. This paper presents two case studies of collaboration with education learning centers at Salisbury Cathedral and Winchester Cathedral. The paper outlines workshops and shows developed for pupils aged 6-14 years (UK key stages 2-4) on the electromagnetic spectrum, particle physics, telecommunications and the human eye using a combination of readily obtainable items, hand-built kits and elements from the EYEST Photonics Explorer kit. The activities are interactive to stimulate learning through active participation, complement the UK national curriculum and link the themes of science with the non-traditional setting of a cathedral. We present methods to evaluate the impact of the activity and tools to obtain qualitative feedback for continual program improvement. We also

  15. Perceived Learning Effectiveness of a Course Facebook Page: Teacher-Led versus Student-Led Approach

    Science.gov (United States)

    Tugrul, Tugba Orten

    2017-01-01

    This research aims to compare the perceived effectiveness of teacher-led and student-led content management approaches embraced in a course Facebook page designed to enhance traditional classroom learning. Eighty-five undergraduate marketing course students voluntarily completed a questionnaire composed of two parts; a depiction of a course…

  16. Facilitating Vocabulary Acquisition of Children With Cochlear Implants Using Electronic Storybooks.

    Science.gov (United States)

    Messier, Jane; Wood, Carla

    2015-10-01

    The present intervention study explored the word learning of 18 children with cochlear implants in response to E-book instruction. Capitalizing on the multimedia options available in electronic storybooks, the intervention incorporated videos and definitions to provide a vocabulary intervention that includes evidence-based teaching strategies. The extent of the children's word learning was assessed using three assessment tasks: receptive pointing, expressively labeling, and word defining. Children demonstrated greater immediate expressive labeling gains and definition generation gains for words taught in the treatment condition compared to those in the comparison condition. In addition, the children's performance on delayed posttest vocabulary assessments indicated better retention across the expressive vocabulary task for words taught within the treatment condition as compared to the comparison condition. Findings suggest that children with cochlear implants with functional speech perception can benefit from an oral-only multimedia-enhanced intensive vocabulary instruction. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Color adjustable LED driver design based on PWM

    Science.gov (United States)

    Du, Yiying; Yu, Caideng; Que, Longcheng; Zhou, Yun; Lv, Jian

    2012-10-01

    Light-emitting diode (LED) is a liquid cold source light source that rapidly develops in recent years. The merits of high brightness efficiency, long duration, high credibility and no pollution make it satisfy our demands for consumption and natural life, and gradually replace the traditional lamp-house-incandescent light and fluorescent light. However, because of the high cost and unstable drive circuit, the application range is restricted. To popularize the applications of the LED, we focus on improving the LED driver circuit to change this phenomenon. Basing on the traditional LED drive circuit, we adopt pre-setup constant current model and introduce pulse width modulation (PWM) control method to realize adjustable 256 level-grays display. In this paper, basing on human visual characteristics and the traditional PWM control method, we propose a new PWM control timing clock to alter the duty cycle of PWM signal to realize the simple gamma correction. Consequently, the brightness can accord with our visual characteristics.

  18. 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...

  19. Spectral Design Flexibility of LED Brings Better life

    DEFF Research Database (Denmark)

    Ou, Haiyan; Corell, Dennis Dan; Ou, Yiyu

    2012-01-01

    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...

  20. 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

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

    Science.gov (United States)

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

    2016-08-08

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

  2. LED; Zum Thema LED

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    This collection of articles on the subject of light emitting diodes (LED) provides technical information on LED technology, examines latest developments and provides examples of LED use in practice. An 'ABC' of LED technology is presented and fifteen common LED mistakes are noted. The chances and risks of LED use are discussed as is the retrofitting of lighting installations with LEDs. The use of LEDs in street lighting is examined. The journal also includes interviews with architects and a lighting designer. Practical examples of the use of LEDs include the refurbished parliamentary library in Berne, their use in the bird sanctuary headquarters in Sempach, Switzerland, as well as LED use in sales outlets. Also, the use of LED lighting in a spa gazebo in Lucerne is examined.

  3. Design of LED projector based on gradient-index lens

    Science.gov (United States)

    Qian, Liyong; Zhu, Xiangbing; Cui, Haitian; Wang, Yuanhang

    2018-01-01

    In this study, a new type of projector light path is designed to eliminate the deficits of existing projection systems, such as complex structure and low collection efficiency. Using a three-color LED array as the lighting source, by means of the special optical properties of a gradient-index lens, the complex structure of the traditional projector is simplified. Traditional components, such as the color wheel, relay lens, and mirror, become unnecessary. In this way, traditional problems, such as low utilization of light energy and loss of light energy, are solved. With the help of Zemax software, the projection lens is optimized. The optimized projection lens, LED, gradient-index lens, and digital micromirror device are imported into Tracepro. The ray tracing results show that both the utilization of light energy and the uniformity are improved significantly.

  4. University of Nevada Las Vegas LED Display Engineering

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-08-31

    The primary objective of this part of the project is to develop and implement a method that compensates for the inefficiency of the green LED. The proposed engineering solution which will be the backbone of this project will be to use RGBW combination in every pixel to save energy. Two different RGBW geometrical pixel configurations will be implemented and compared against traditional LED configurations. These configurations will be analyzed for energy efficiency while keeping the quality of the display the same. Cost of the addition of white LEDs to displays along with energy cost savings will be presented and analyzed.

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

    OpenAIRE

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

    2011-01-01

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

  6. 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

  7. Standardization of UV LED measurements

    Science.gov (United States)

    Eppeldauer, G. P.; Larason, T. C.; Yoon, H. W.

    2015-09-01

    Traditionally used source spectral-distribution or detector spectral-response based standards cannot be applied for accurate UV LED measurements. Since the CIE standardized rectangular-shape spectral response function for UV measurements cannot be realized with small spectral mismatch when using filtered detectors, the UV measurement errors can be several times ten percent or larger. The UV LEDs produce broadband radiation and both their peaks or spectral bandwidths can change significantly. The detectors used for the measurement of these LEDs also have different spectral bandwidths. In the discussed example, where LEDs with 365 nm peak are applied for fluorescent crack-recognition using liquid penetrant (non-destructive) inspection, the broadband radiometric LED (signal) measurement procedure is standardized. A UV LED irradiance-source was calibrated against an FEL lamp standard to determine its spectral irradiance. The spectral irradiance responsivity of a reference UV meter was also calibrated. The output signal of the reference UV meter was calculated from the spectral irradiance of the UV source and the spectral irradiance responsivity of the reference UV meter. From the output signal, both the integrated irradiance (in the reference plane of the reference meter) and the integrated responsivity of the reference meter were determined. Test UV meters calibrated for integrated responsivity against the reference UV meter, can be used to determine the integrated irradiance from a field UV source. The obtained 5 % (k=2) measurement uncertainty can be decreased when meters with spectral response close to a constant value are selected.

  8. 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.

  9. Communication about emotions during storybook reading: Effects of an instruction programme for children with Down syndrome.

    Science.gov (United States)

    Na, Ji Young; Wilkinson, Krista M

    2017-08-07

    Children with Down syndrome often have more restricted emotion expression and recognition skills than their peers who are developing typically, and potentially fewer opportunities to learn these skills. This study investigated the effect of the Strategies for Talking about Emotions as PartnerS (STEPS) programme on parents' provision of opportunities for emotion communication using visual communication supports. The study used a single-subject multiple-baseline across participants design with three parent-child dyads. Shared book reading was used as the context for parent instruction and data collection. Parents increased their use of the emotion communication strategies immediately following an instructional session, and continued to use them for the remaining phases of the study. In turn, the children participated more actively in the discussion by making comments about emotions when parents provided more opportunities. The STEPS instructional programme is effective for improving parents' provision of opportunities for discussing emotions during storybook reading with children who have Down syndrome. All parents indicated that they would use the strategy during future reading activities. This paper discusses the results of the study and directions for future research.

  10. EVALUATION OF ADOPTION OF LED LIGHTING TECHNOLOGY IN MALAYSIA

    OpenAIRE

    Khorasanizadeh, Hasti

    2017-01-01

    Electrical energy consumption in Malaysia is rapidly increasing with illumination being the second largest contributor to this increment. Light Emitting Diode (LED) could be a viable option to reduce the illumination based energy consumption. LEDs are energy efficient and easier to recycle compared to traditional lighting sources such as incandescent and fluorescent lamps. They also have longer life time and lower failure rate. In this thesis, the feasibility of replacing...

  11. LED-driven backlights for automotive displays

    Science.gov (United States)

    Strauch, Frank

    2007-09-01

    As a light source the LED has some advantage over the traditionally used fluorescence tube such as longer life or lower space consumption. Consequently customers are asking for the LED lighting design in their products. We introduced in a company owned backlight the white LED technology. This step opens the possibility to have access to the components in the display market. Instead of having a finalized display product which needs to be integrated in the head unit of a car we assemble the backlight, the glass, own electronics and the housing. A major advantage of this concept is the better control of the heat flow generated by the LEDs to the outer side because only a common housing is used for all the components. Also the requirement for slim products can be fulfilled. As always a new technology doesn't come with advantages only. An LED represents a point source compared to the well-known tube thus requiring a mixing zone for the multiple point sources when they enter a light guide. This zone can't be used in displays because of the lack of homogeneity. It's a design goal to minimize this zone which can be helped by the right choice of the LED in terms of slimness. A step ahead is the implementation of RGB LEDs because of their higher color rendering abilities. This allows for the control of the chromaticity point under temperature change but as a drawback needs a larger mixing zone.

  12. Traditional Medicine in Developing Countries

    DEFF Research Database (Denmark)

    Thorsen, Rikke Stamp

    or spiritual healer and self-treatment with herbal medicine or medicinal plants. Reliance on traditional medicine varies between countries and rural and urban areas, but is reported to be as high as 80% in some developing countries. Increased realization of the continued importance of traditional medicine has......People use traditional medicine to meet their health care needs in developing countries and medical pluralism persists worldwide despite increased access to allopathic medicine. Traditional medicine includes a variety of treatment opportunities, among others, consultation with a traditional healer...... led to the formulation of policies on the integration of traditional medicine into public health care. Local level integration is already taking place as people use multiple treatments when experiencing illness. Research on local level use of traditional medicine for health care, in particular the use...

  13. Interpersonal Skills Training: Online versus Instructor-Led Courses.

    Science.gov (United States)

    Gilmore, Erika R.; Fritsch, Paula J.

    2001-01-01

    Compares instructional methods used in interpersonal skills training courses delivered online to the methods used in similar courses delivered in a traditional instructor-led classroom. Discusses implications for performance improvement professionals who are responsible for selecting and designing interpersonal skills training interventions.…

  14. Designing Instructor-Led Schools with Rapid Prototyping.

    Science.gov (United States)

    Lange, Steven R.; And Others

    1996-01-01

    Rapid prototyping involves abandoning many of the linear steps of traditional prototyping; it is instead a series of design iterations representing each major stage. This article describes the development of an instructor-led course for midlevel auditors using the principles and procedures of rapid prototyping, focusing on the savings in time and…

  15. Identifying the Principles of Traditional Iranian Architecture in the Light of Vastu Shastra, the Traditional Indian Wisdom

    Directory of Open Access Journals (Sweden)

    Ali Goodarzi

    2014-06-01

    Full Text Available Traditional Iranian houses have always been recognized as examples of 'good-design' in the context of Iranian Architecture according to many scholars. It is believed that their creation has been influenced by the systems of beliefs in the traditional Iranian society; an established system closely followed in their design process which has led to their phenomenal architectural design. The traditional houses of Kashan are excellent examples of such which have often been described as the finest examples of Traditional Iranian houses. However insufficient documentation of the design process of these architectural masterpieces has led to disputes among scholars in determining the exacct architectural system, behind their creation. The effect therefore is not only the inability in creating houses with the same quality in current architectural societies of Iran, but also their decay due to lack of attention and preservation. Historical studies point towards an influence of Indian Architectural system, Vastu Shastra, on the creation of traditional Iranian houses, which appears to be the earlier practice of house design within the Indo-Aryan communities. Using Vastu Shastra as a framework, the objective is to conduct case studies on 22 traditional houses of Kashan to identify the existence of a similar well-established system in Iran based on which all the traditional houses have been designed, and further to introduce it as the traditional architectural system in Iran. In this way the principles of traditional houses of Kashan can be identified in the light of Vastu Shastra, the traditional Indian wisdom.

  16. 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.

  17. 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.

  18. How Science Really Works: The Student Experience of Research-Led Education

    Science.gov (United States)

    Smyth, Lillian; Davila, Federico; Sloan, Thomas; Rykers, Ellen; Backwell, Sam; Jones, Stephen B.

    2016-01-01

    There has been a shift in modern tertiary education theory that has moved away from a traditional, didactic model of education, towards a more student-led, constructivist approach. Nowhere is this more the case than in science and mathematical education, where the concept of research-led education is gaining more and more traction. The focus of…

  19. Novel rare-earth doped silicon-nitride based materials as promising conversion phosphors for white LEDs

    NARCIS (Netherlands)

    Li, Yuan Qiang; Hintzen, H.T.J.M.

    2006-01-01

    Lighting world will change drastically due to the replacement of the traditional TL, PL and incandescent lamps by white LEDs. Advantageous features of white LEDs are a longer lifetime, lower energy consumption and extended possibilities for integration and miniaturisation. A white LED can be

  20. Packaging technology of LEDs for LCD backlights

    International Nuclear Information System (INIS)

    Fan Manning; Liang Meng; Wang Guohong

    2009-01-01

    We design a package patterned with red and green emitting phosphors excited by a blue LED to emit tri-basic mixing color. For high backlight display quality, we compare several phosphors. According to our measurements, green phosphors 0752G, 0753G and red phosphor 0763R are preferred for producing a good backlight source. Compared to RGB-LED backlight units, this frame typically benefits the lighting uniformity, and can simplify the structures. It also provides higher color render and better CCT than the traditional package method of a yellow phosphor with a blue chip. However, its light efficiency needs to be further improved for the use of backlights for LCDs.

  1. Traditional Chinese Biotechnology

    Science.gov (United States)

    Xu, Yan; Wang, Dong; Fan, Wen Lai; Mu, Xiao Qing; Chen, Jian

    The earliest industrial biotechnology originated in ancient China and developed into a vibrant industry in traditional Chinese liquor, rice wine, soy sauce, and vinegar. It is now a significant component of the Chinese economy valued annually at about 150 billion RMB. Although the production methods had existed and remained basically unchanged for centuries, modern developments in biotechnology and related fields in the last decades have greatly impacted on these industries and led to numerous technological innovations. In this chapter, the main biochemical processes and related technological innovations in traditional Chinese biotechnology are illustrated with recent advances in functional microbiology, microbial ecology, solid-state fermentation, enzymology, chemistry of impact flavor compounds, and improvements made to relevant traditional industrial facilities. Recent biotechnological advances in making Chinese liquor, rice wine, soy sauce, and vinegar are reviewed.

  2. Teaching Vocabulary to Preschoolers with Disabilities Using Adult-Child Shared Bookreading: A Comparison of Traditional and Electronic Books

    Science.gov (United States)

    Rhodehouse, Sara Bernice

    2013-01-01

    This study sought to validate adult-child shared storybook reading as a method for teaching target vocabulary words to preschool children with disabilities. The Vocabulary Learning through Books (VLTB) instructional procedure incorporates, adult-child book reading, questioning during reading requiring the child to answer with a target word, and…

  3. African Traditional Knowledge Systems and Biodiversity Management

    African Journals Online (AJOL)

    There is a link between African Traditional Knowledge Systems and the management of Biodiversity. These have been passed over from one generation to the next through oral tradition. The lack of documentation of these systems of managing biodiversity has led to the existence of a gap between the scientifi cally based ...

  4. 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.

  5. Promoting language and social communication development in babies through an early storybook reading intervention.

    Science.gov (United States)

    Brown, Michelle I; Westerveld, Marleen F; Trembath, David; Gillon, Gail T

    2017-12-15

    This study examined the effectiveness of low- and high-intensity early storybook reading (ESR) intervention workshops delivered to parents for promoting their babies language and social communication development. These workshops educated parents on how to provide a stimulating home reading environment and engage in parent-child interactions during ESR. Parent-child dyads (n = 32); child age: 3-12 months, were assigned into two intervention conditions: low and high intensity (LI versus HI) groups. Both groups received the same ESR strategies; however, the HI group received additional intervention time, demonstrations and support. Outcome measures were assessed pre-intervention, one and three months post-intervention and when the child turned 2 years of age. A significant time-group interaction with increased performance in the HI group was observed for language scores immediately post-intervention (p = 0.007) and at 2-years-of-age (p = 0.022). Significantly higher broader social communication scores were associated with the HI group at each of the time points (p = 0.018, p = 0.001 and p = 0.021, respectively). Simple main effect revealed that both groups demonstrated a significant improvement in language, broader social communication and home reading practices scores. ESR intervention workshops may promote language and broader social communication skills. The HI ESR intervention workshop was associated with significantly higher language and broader social communication scores.

  6. Projecting LED product life based on application

    Science.gov (United States)

    Narendran, Nadarajah; Liu, Yi-wei; Mou, Xi; Thotagamuwa, Dinusha R.; Eshwarage, Oshadhi V. Madihe

    2016-09-01

    LED products have started to displace traditional light sources in many lighting applications. One of the commonly claimed benefits for LED lighting products is their long useful lifetime in applications. Today there are many replacement lamp products using LEDs in the marketplace. Typically, lifetime claims of these replacement lamps are in the 25,000-hour range. According to current industry practice, the time for the LED light output to reach the 70% value is estimated according to IESNA LM-80 and TM-21 procedures and the resulting value is reported as the whole system life. LED products generally experience different thermal environments and switching (on-off cycling) patterns when used in applications. Current industry test methods often do not produce accurate lifetime estimates for LED systems because only one component of the system, namely the LED, is tested under a continuous-on burning condition without switching on and off, and because they estimate for only one failure type, lumen depreciation. The objective of the study presented in this manuscript was to develop a test method that could help predict LED system life in any application by testing the whole LED system, including on-off power cycling with sufficient dwell time, and considering both failure types, catastrophic and parametric. The study results showed for the LED A-lamps tested in this study, both failure types, catastrophic and parametric, exist. The on-off cycling encourages catastrophic failure, and maximum operating temperature influences the lumen depreciation rate and parametric failure time. It was also clear that LED system life is negatively affected by on-off switching, contrary to commonly held belief. In addition, the study results showed that most of the LED systems failed catastrophically much ahead of the LED light output reaching the 70% value. This emphasizes the fact that life testing of LED systems must consider catastrophic failure in addition to lumen depreciation, and

  7. Control and Driving Methods for LED Based Intelligent Light Sources

    OpenAIRE

    Beczkowski, Szymon

    2012-01-01

    High power light-emitting diodes allow the creation of luminaires capable of generating saturated colour light at very high efficacies. Contrary to traditional light sources like incandescent and high-intensity discharge lamps, where colour is generated using filters, LEDs use additive light mixing, where the intensity of each primary colour diode has to be adjusted to the needed intensity to generate specified colour. The function of LED driver is to supply the diode with power needed to ach...

  8. UV-LEDs Efficiently Inactivate DNA and RNA Coliphages

    Directory of Open Access Journals (Sweden)

    Alyaa M. Zyara

    2017-01-01

    Full Text Available UV-LEDs are a new method of disinfecting drinking water. Some viruses are very resistant to UV and the efficiency of UV-LEDs to disinfect them needs to be studied. Drinking water was disinfected with UV-LEDs after spiking the water with MS2 and four UV- and/or Cl-resistant coliphages belonging to RNA or DNA coliphages isolated from municipal wastewater. UV-LEDs operating at a wavelength of 270 nm for 2 min with 120 mW of irradiation caused 0.93–2.73 Log10-reductions of coliphages tested in a reactor of a 5.2 L volume. Irradiation time of 10 min in the same system increased the Log10-reductions to 4.30–5.16. Traditional mercury UV (Hg-UV lamp at a 254 nm wavelength caused 0.67–4.08 Log10-reductions in 2 min and 4.56–7.21 Log10-reductions in 10 min in 10 mL of water. All coliphages tested except MS2 achieved 4 Log10-reductions with UV-LEDs at a dose that corresponded to 70 mWs/cm2 using Hg-UV. Thus, UV-LEDs are a promising method of disinfecting UV- and/or Cl-resistant viruses.

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

    DEFF Research Database (Denmark)

    Qu, Xiaohui; Wang, Huai; Zhan, Xiaoqing

    2017-01-01

    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......The Light-Emitting Diode (LED) has become a very promising alternative lighting source with the advantages of longer lifetime and higher efficiency than traditional ones. The lifetime prediction of LEDs is important to guide the LED system designers to fulfill the design specifications...... properties of the life data available from accelerated degradation testing. The electrical and thermal characteristics of LEDs are measured by a T3Ster system, used for the electro-thermal modeling. It also identifies key variables (e.g., heat sink parameters) that can be designed to achieve a specified...

  10. Design and Manufacture of a Novel LED Table Lamp with Flower Decoration

    OpenAIRE

    Tzer-Ming Jeng; Sheng-Chung Tzeng; Wei-Ting Hsu; Chia-Hung Chang; Yu-Xiang Huang

    2014-01-01

    This work involved the design and manufacture of a novel LED table lamp that provides for flower decoration. It is a combination of a normal LED table lamp and attachments holding flower arrangement frogs. In this application the frogs, as used for traditional flower arrangements, became heat sinks for the LED units. They are made of an aluminum alloy to give good heat transfer and dissipation. In any case since they are fixed to the unit they do not need to be very heavy. The design features...

  11. Storybook Read-Alouds to Enhance Students’ Comprehension Skills in ESL Classrooms: A Case Study

    Directory of Open Access Journals (Sweden)

    Ainon Omar

    2015-06-01

    Full Text Available The effectiveness of using storybooks during read-alouds to develop children’s comprehension skills as well as in understanding the story has been widely studied. The reading aloud strategy has also been proven through numerous researches to be the most highly recommended activity for encouraging language and literacy. The study identified the comprehension strategies used by the teachers during their read-aloud sessions, matched teachers’ current practices using the comprehension strategies to the identified practices for the approach, and obtained the teachers’ perceptions of their current practices of the comprehension strategies during reading aloud in their English language classrooms. The teachers’ comprehension strategies were matched with a research-based strategy for comprehending texts during read-alouds proposed by Whitehurst et al (1994. Three primary school English language teachers teaching in the rural schools participated in this study. Qualitative research methods were used in this study. Primary data was obtained through observations using an observation protocol; while secondary data was obtained through interviews from teachers. Findings from the study revealed that the three teachers employed a few of the comprehension strategies that were proposed by researchers in the field. The findings also indicate that the teachers utilized only the strategies that they thought were relevant to their teaching context and as such, proposed the need to provide teachers with knowledge on the best practices for conducting reading aloud to develop ESL students’ comprehension skills

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

    Directory of Open Access Journals (Sweden)

    Marzieh Khademalrasool

    2016-09-01

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

  13. Assessing the use of Low Voltage UV-light Emitting Miniature LEDs for Marine Biofouling Control

    Science.gov (United States)

    2016-07-01

    of that required to drive traditional UV mercury lamps . Secondly, given their small size and relatively low cost, UV LEDs provide ease of maintenance...UNCLASSIFIED UNCLASSIFIED Assessing the use of Low Voltage UV -light Emitting Miniature LEDs for Marine Biofouling Control Richard...settling organisms. The introduction of miniature UV light emitting diodes ( LEDs ) as a light source enables them to be embedded into thin, flexible

  14. Authenticating Children's Literature: Raising Cultural Awareness with an Inquiry-Based Project in a Teacher Education Course

    Science.gov (United States)

    Smith, Jane; Wiese, Patricia

    2006-01-01

    This article discusses the importance of authentic picture-storybook adaptations of multicultural folktales and describes an action research project through which a children's picture-book adaptation of a traditional tale can be authenticated using an inquiry-based process. In addition to modeling an actual authentication project using "The Golden…

  15. Design of Elliptic Reflective LED Surgical Shadowless Lamps Using Mathematical Optical Tracing Algorithms

    Directory of Open Access Journals (Sweden)

    Cheng-Tang Pan

    2014-01-01

    Full Text Available Traditional surgical shadowless halogen lamps are generally designed as projection type with many light bulbs, which can produce not only mercury pollution but also heat radiation that are serious problems to patient. The study utilized Runge-Kutta methods and mathematical algorithms to design and optimize the freeform lens. The LED (light-emitting diode was adopted to replace the traditional halogen lamp. A uniform lens was designed and fabricated based on the energy conservation. At first, the light field of LED is concentrated through the freeform lens to improve the optical efficiency. Second, the three-shell elliptic curves are applied to the reflective surgical shadowless lamps, where only few LED chips are needed. Light rays emitting from different directions to the target plane can achieve the goal of shadowless. In this study, the LED’s luminance flux is 1,895 lm. The shadow dilution on the target plane is 54%. Ec (central illuminance is 114,900 lux, and the d50/d10 is 57% which is higher than the regulation by 7%, whereas the power consumption is only 20 W. The energy of reflective surgical shadowless lamps can save more than 50%, compared with the traditional projective one.

  16. High-performance LED luminaire for sports hall

    Science.gov (United States)

    Lee, Xuan-Hao; Yang, Jin-Tsung; Chien, Wei-Ting; Chang, Jung-Hsuan; Lo, Yi-Chien; Lin, Che-Chu; Sun, Ching-Cherng

    2015-09-01

    In this paper, we present a luminaire design with anti-glare and energy-saving effects for sports hall. Compared with traditional lamps using in a badminton court, the average illuminance on the ground of the proposed LED luminaire is enhanced about 300%. Besides, the uniformity is obviously enhanced and improved. The switch-on speed of lighting in sports hall is greatly reduced from 5-10 minutes to 1 second. The simulation analysis and the corresponding experiment results are demonstrated.

  17. Development of a LED based standard for luminous flux

    Science.gov (United States)

    Sardinha, André; Ázara, Ivo; Torres, Miguel; Menegotto, Thiago; Grieneisen, Hans Peter; Borghi, Giovanna; Couceiro, Iakyra; Zim, Alexandre; Muller, Filipe

    2018-03-01

    Incandescent lamps, simple artifacts with radiation spectrum very similar to a black-body emitter, are traditional standards in photometry. Nowadays LEDs are broadly used in lighting, with great variety of spectra, and it is convenient to use standards for photometry with spectral distribution similar to that of the measured artifact. Research and development of such standards occur in several National Metrology Institutes. In Brazil, Inmetro is working on a practical solution for providing a LED based standard to be used for luminous flux measurements in the field of general lighting. This paper shows the measurements made for the developing of a prototype, that in sequence will be characterized in photometric quantities.

  18. New reversing freeform lens design method for LED uniform illumination with extended source and near field

    Science.gov (United States)

    Zhao, Zhili; Zhang, Honghai; Zheng, Huai; Liu, Sheng

    2018-03-01

    In light-emitting diode (LED) array illumination (e.g. LED backlighting), obtainment of high uniformity in the harsh condition of the large distance height ratio (DHR), extended source and near field is a key as well as challenging issue. In this study, we present a new reversing freeform lens design algorithm based on the illuminance distribution function (IDF) instead of the traditional light intensity distribution, which allows uniform LED illumination in the above mentioned harsh conditions. IDF of freeform lens can be obtained by the proposed mathematical method, considering the effects of large DHR, extended source and near field target at the same time. In order to prove the claims, a slim direct-lit LED backlighting with DHR equal to 4 is designed. In comparison with the traditional lenses, illuminance uniformity of LED backlighting with the new lens increases significantly from 0.45 to 0.84, and CV(RMSE) decreases dramatically from 0.24 to 0.03 in the harsh condition. Meanwhile, luminance uniformity of LED backlighting with the new lens is obtained as high as 0.92 at the condition of extended source and near field. This new method provides a practical and effective way to solve the problem of large DHR, extended source and near field for LED array illumination.

  19. A First Nations-led social innovation: a moose, a gold mining company, and a policy window

    Directory of Open Access Journals (Sweden)

    Daniel D. P. McCarthy

    2014-12-01

    combined with several other factors, including: (1 the high price of gold; (2 a mining company seeking to demonstrate corporate social responsibility to repair its international reputation with indigenous peoples by supporting an innovative, local Indigenous-led initiative; and (3 a new policy context, including Supreme Court of Canada decisions and provisions in the updated Ontario Mining Act, that require meaningful consultation with indigenous peoples has led to the emergence of a indigenous peoples-led collaborative, social innovation. This policy window allowed for the formation of an unprecedented council of indigenous knowledge holders (elders and traditional practitioners to help inform mine restoration and practice as well as to foster the resurgence of traditional language and culture in local indigenous communities. Here, we document this unprecedented social change opportunity.

  20. LED-based high-speed visible light communications

    Science.gov (United States)

    Chi, Nan; Shi, Meng; Zhao, Yiheng; Wang, Fumin; Shi, Jianyang; Zhou, Yingjun; Lu, Xingyu; Qiao, Liang

    2018-01-01

    We are seeing a growing use of light emitting diodes (LEDs) in a range of applications including lighting, TV and backlight board screen, display etc. In comparison with the traditional incandescent and fluorescent light bulbs, LEDs offer long life-space, much higher energy efficiency, high performance cost ratio and above all very fast switching capability. LED based Visible Light Communications (VLC) is an emerging field of optical communications that focuses on the part of the electromagnetic spectrum that humans can see. Depending on the transmission distance, we can divide the whole optical network into two categories, long haul and short haul. Visible light communication can be a promising candidate for short haul applications. In this paper, we outline the configuration of VLC, its unique benefits, and describe the state of the art research contributions consisting of advanced modulation formats including adaptive bit loading OFDM, carrierless amplitude and phase (CAP), pulse amplitude modulation (PAM) and single carrier Nyquist, linear equalization and nonlinear distortion mitigation based on machine learning, quasi-balanced coding and phase-shifted Manchester coding. These enabling technologies can support VLC up to 10Gb/s class free space transmission.

  1. 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)

  2. An accelerated test method of luminous flux depreciation for LED luminaires and lamps

    International Nuclear Information System (INIS)

    Qian, C.; Fan, X.J.; Fan, J.J.; Yuan, C.A.; Zhang, G.Q.

    2016-01-01

    Light Emitting Diode (LED) luminaires and lamps are energy-saving and environmental friendly alternatives to traditional lighting products. However, current luminous flux depreciation test at luminaire and lamp level requires a minimum of 6000 h testing, which is even longer than the product development cycle time. This paper develops an accelerated test method for luminous flux depreciation to reduce the test time within 2000 h at an elevated temperature. The method is based on lumen maintenance boundary curve, obtained from a collection of LED source lumen depreciation data, known as LM-80 data. The exponential decay model and Arrhenius acceleration relationship are used to determine the new threshold of lumen maintenance and acceleration factor. The proposed method has been verified by a number of simulation studies and experimental data for a wide range of LED luminaire and lamp types from both internal and external experiments. The qualification results obtained by the accelerated test method agree well with traditional 6000 h tests. - Highlights: • We develop an accelerated test method for LED luminaires and lamps. • The method is proposed based on a “Boundary Curve” concept. • The parameters of the boundary curve are extracted from LM-80 test reports. • Qualification results from the proposed method agree with ES requirements.

  3. Between tradition and renewal: Some considerations about the use of tradition in reformed theology

    Directory of Open Access Journals (Sweden)

    Willem van Vlastuin

    2013-08-01

    Full Text Available In the theology and practice of the Christian church a tension between tradition and renewal exists. This essay focuses on this tension to provide a first step of methodological reflection to deal with it. Firstly, this tension is illustrated from the reformed perspective of sola scripturathat led to criticism of the tradition on the one hand, whilst understanding the reformed movement as part of the tradition on the other hand. A danger of unqualified sola scriptura is subjectivity. Subsequently, the importance of tradition is elaborated from the perspective of the church as the body of Christ across all ages. This implies that Christians should study and love the traditional theology because of the fundamental unity of the church that transcends cultural diversity. Rejecting tradition will cut the church from its historical and spiritual roots. Thirdly, this raises the question whether the church is imprisoned by tradition, as well as the problem of the relation between tradition and renewal. In response, it is argued that the doctrine of incarnation guarantees openness to history. With the help of the philosophical and Christian view on structural contingency, the belief that tradition is principally open to renewal is defended. Some examples are given as illustrations of how classic theological concepts can be reframed in our postmodern context. The last part of this essay concludes with the insight of Cyprian that only the conveyed tradition can be renewed, implying that renewal is in essence not a new theology, but a new application of apostolic theology.

  4. TRADITIONAL REMEDIES IN CHILDREN AROUND EASTERN ...

    African Journals Online (AJOL)

    hi-tech

    2003-08-08

    Aug 8, 2003 ... remain largely unproven by the scientific method and the concern about adverse effects have led to closer scrutiny of these products (4). Whereas most traditional remedies are safe, the potential for adverse effects or intoxication exists, as does the possibility of interaction with conventional drugs (2, 5-8).

  5. 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.

  6. Methods of Conflict Resolution in African Traditional Society

    African Journals Online (AJOL)

    Toshiba

    Department of History and International Studies. Faculty of Arts, Ekiti State ... and market brawls, skirmishes and wars, public insurrections and assaults. ..... treaty making by traditional rulers and leaders of thought led by Igwe. Nzekwesi, for ...

  7. Design and Manufacture of a Novel LED Table Lamp with Flower Decoration

    Directory of Open Access Journals (Sweden)

    Tzer-Ming Jeng

    2014-08-01

    Full Text Available This work involved the design and manufacture of a novel LED table lamp that provides for flower decoration. It is a combination of a normal LED table lamp and attachments holding flower arrangement frogs. In this application the frogs, as used for traditional flower arrangements, became heat sinks for the LED units. They are made of an aluminum alloy to give good heat transfer and dissipation. In any case since they are fixed to the unit they do not need to be very heavy. The design features of this novel flower-arrangement LED table lamp are: (1 the use of a light aluminum alloy flower decoration frog as a heat sink which gives both high heat dissipation and allows decorative flower arrangement; (2 the installation of LED lamps at three points of the same plate above a cylinder covered with a glass lampshade to achieve a beautiful effect; (3 to provide three different lighting modes for reading, use as a night light and for flower decoration. This novel LED table lamp meets all the energy-saving and environmental protection requirements. It has commercial potential in the market for LED lamps.

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

    Science.gov (United States)

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

    2014-03-10

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

  9. [Hygienic aspects of the use of LED light sources for general illumination in schools].

    Science.gov (United States)

    Kuchma, V R; Sukhareva, L M; Teksheva, L M; Stepanova, M I; Sazaniuk, Z I

    2013-01-01

    For the time present becoming more common semiconductor sources of artificial lighting has become a more and more frequent practice. With the aim to study the impact of LEDs on the health of schoolchildren studies in experimental conditions (specially equipped classrooms) were performed. The comparative analysis of the state of vision, mental health and emotional state of pupils in primary, middle and high schools under fluorescent and LED lighting, meeting to the regulatory requirements, has revealed that the physiological cost of schooling in the use of LED units in classrooms is lower than in a traditional, fluorescent lighting.

  10. Hybrid sunlight/LED illumination and renewable solar energy saving concepts for indoor lighting.

    Science.gov (United States)

    Tsuei, Chih-Hsuan; Sun, Wen-Shing; Kuo, Chien-Cheng

    2010-11-08

    A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

  11. White LEDs and modules in chip-on-board technology for general lighting

    Science.gov (United States)

    Hartmann, Paul; Wenzl, Franz P.; Sommer, Christian; Pachler, Peter; Hoschopf, Hans; Schweighart, Marko; Hartmann, Martin; Kuna, Ladislav; Jakopic, Georg; Leising, Guenther; Tasch, Stefan

    2006-08-01

    At present, light-emitting diode (LED) modules in various shapes are developed and designed for the general lighting, advertisement, emergency lighting, design and architectural markets. To compete with and to surpass the performance of traditional lighting systems, enhancement of Lumen output and the white light quality as well as the thermal management and the luminary integration are key factors for success. Regarding these issues, white LEDs based on the chip-on-board (COB) technology show pronounced advantages. State-of-the-art LEDs exploiting this technology are now ready to enter the general lighting segments. We introduce and discuss the specific properties of the Tridonic COB technology dedicated for general lighting. This technology, in combination with a comprehensive set of tools to improve and to enhance the Lumen output and the white light quality, including optical simulation, is the scaffolding for the application of white LEDs in emerging areas, for which an outlook will be given.

  12. A fast template matching method for LED chip Localization

    Directory of Open Access Journals (Sweden)

    Zhong Fuqiang

    2015-01-01

    Full Text Available Efficiency determines the profits of the semiconductor producers. So the producers spare no effort to enhance the efficiency of every procedure. The purpose of the paper is to present a method to shorten the time to locate the LED chips on wafer. The method consists of 3 steps. Firstly, image segmentation and blob analyzation are used to predict the positions of potential chips. Then predict the orientations of potential chips based on their dominant orientations. Finally, according to the positions and orientations predicted above, locate the chips precisely based on gradient orientation features. Experiments show that the algorithm is faster than the traditional method we choose to locate the LED chips. Besides, even the orientations of the chips on wafer are of big deviation to the orientation of the template, the efficiency of this method won't be affected.

  13. A comparative study on effect of e-learning and instructor-led methods on nurses' documentation competency.

    Science.gov (United States)

    Abbaszadeh, Abbas; Sabeghi, Hakimeh; Borhani, Fariba; Heydari, Abbas

    2011-01-01

    Accurate recording of the nursing care indicates the care performance and its quality, so that, any failure in documentation can be a reason for inadequate patient care. Therefore, improving nurses' skills in this field using effective educational methods is of high importance. Since traditional teaching methods are not suitable for communities with rapid knowledge expansion and constant changes, e-learning methods can be a viable alternative. To show the importance of e-learning methods on nurses' care reporting skills, this study was performed to compare the e-learning methods with the traditional instructor-led methods. This was a quasi-experimental study aimed to compare the effect of two teaching methods (e-learning and lecture) on nursing documentation and examine the differences in acquiring competency on documentation between nurses who participated in the e-learning (n = 30) and nurses in a lecture group (n = 31). The results of the present study indicated that statistically there was no significant difference between the two groups. The findings also revealed that statistically there was no significant correlation between the two groups toward demographic variables. However, we believe that due to benefits of e-learning against traditional instructor-led method, and according to their equal effect on nurses' documentation competency, it can be a qualified substitute for traditional instructor-led method. E-learning as a student-centered method as well as lecture method equally promote competency of the nurses on documentation. Therefore, e-learning can be used to facilitate the implementation of nursing educational programs.

  14. Traditional Chinese and Thai medicine in a comparative perspective.

    Science.gov (United States)

    He, Ke

    2015-12-01

    The work presented in this paper compares traditional Chinese medicine and traditional Thai medicine, expounding on origins, academic thinking, theoretical system, diagnostic method and modern development. Based on a secondary analysis of available literature, the paper concentrates on two crucial historical developments: (1) the response to, and consequences of, the impact of the Western medicine; and (2) the revival of traditional medicine in these two countries and its prospects. From a comparative perspective, the analysis has led to the conclusion that the rise and fall of traditional medicine is an issue closely related with social and political issues; and the development of traditional medicines requires national policy and financial support from governments, human resource development, the improvement of service quality, and the dissemination of traditional medicine knowledge to the public. In addition, this paper also suggests deepening exchanges and cooperation between China and Thailand, strengthening cooperation between traditional medicine and medical tourism. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Permanent transparent color-warming glazes for dimmable and non-dimmable LED bulbs

    Science.gov (United States)

    Spanard, Jan-Marie A.

    2014-02-01

    Illuminant metameric failure is frequently experienced when viewing material samples under LED generated light vs. traditional incandescent light. LED light temperatures can be improved with phosphor coatings, but long-wave red light is still generally absent in LED "warm-white" light, resulting in metameric failure of orange-to-red objects. Drawing on techniques developed for the architectural restoration of stained glass, we find that transparent, heat-resistant, permanent, pigmented coatings can be applied to any glass, aluminum or plastic surface of an LED bulb, including the phosphor plate, dome or envelope, to produce warmer visible light than in current warm-light LED bulbs. These glazes can be applied in combination with existing technologies to better tune the LED emitted light or they may be used alone. These pigmented coatings include, but are not limited to, those made by suspending inorganic materials in potassium silicates or durable transparent pigmented resins. The pigmented resin glazes may be produced in either a clear gloss vehicle or an iridescent, light diffusing transparent base. Further, a graduated density of the tinted glazes on dimmable bulbs allow the light to change color as wattage is diminished. The glazes may be applied in the manufacturing of the bulb or marketed to current bulb owners as an after-market product to better tune the thousands of LED light bulbs currently in use.

  16. Evaluation of a primary prevention program for anxiety disorders using story books with children aged 9-12 years.

    Science.gov (United States)

    Bouchard, Stéphane; Gervais, Jean; Gagnier, Nadia; Loranger, Claudie

    2013-10-01

    This article reports the results of a study evaluating a book-supported primary prevention program "Dominique's Handy Tricks" for anxiety disorders in children aged 9-12 years. This cognitive-behavioural program is delivered using a combination of storybooks and workshop sessions. The originality of the program comes from the use of storybooks that were not developed specifically for anxiety management. Every session is based on a story describing characters facing common stressors and how they manage to cope with their daily problems. In our randomized control trial with 46 children, participation in the program led to a significant improvement in coping skills, perceived self-efficacy, anxiety sensitivity, as well as in symptoms of anxiety and fear. The theoretical and practical elements underlying the delivery of this primary prevention program are described. It is suggested that such an approach, without any labelling specific to anxiety disorders, can be useful in primary prevention programs.

  17. Validation of the spectral mismatch correction factor using an LED-based solar simulator

    DEFF Research Database (Denmark)

    Riedel, Nicholas; Santamaria Lancia, Adrian Alejo; Thorsteinsson, Sune

    LED-based solar simulators are gaining popularity in the PV characterization field. There are several reasons for this trend, but the primary interest is often the potential of tuning the light source spectrum to a closer match to the AM 1.5G reference spectrum than traditional Xenon or metal-hal...

  18. 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...

  19. The design of optical module of LED street lamp with non-axial symmetrical reflector

    Science.gov (United States)

    Lu, Ming-Jun; Chen, Chi-An; Chen, Yi-Yung; Whang, Allen Jong-Woei

    2010-05-01

    In recently, many research focus on the LED applications for environmental protection so a number of LED street lamps are presented. Although LED has many advantages for environmental protection, its special optical characteristics, such as intensity distribution, always limit the advantages in many applications. Therefore, we always need to do the secondary optical design for LED street lamp to replace the traditional optical designs that are designed for high-pressure sodium lamps and mercury lamps. According to the situation, we design an optical module of LED street lamp with LEDs and secondary optical design. First, the LEDs are placed on freeform reflector for the specific illuminated conditions. We design the optical module of street lamp with the two conditions that include the uniformity and the ratio of length to width in the illuminated area and without any light pollution. According to the simulation with the designed optical module, the uniformity in the illuminated area is about 0.6 that is better than the general condition, 0.3, and the ratio of length to width in the illuminated area is 3:1 in which the length is 30 meters and the width is 10 meters. Therefore, the design could let LED street lamp fits the two conditions, uniformity and ratio in the illuminated area.

  20. Correction of Severe Traditional Medication-induced Lower Lid ...

    African Journals Online (AJOL)

    Setting: The correction of the lower lid tarsal ectropion was carried out at the Rachel Eye Center in Abuja, Nigeria. Result: After conservative intervention failed, a free preauricular skin graft of the floppy ectropion, led to a stable correction. Conclusions: Harmful traditional eye medication continues to be a problem in the ...

  1. Color design model of high color rendering index white-light LED module.

    Science.gov (United States)

    Ying, Shang-Ping; Fu, Han-Kuei; Hsieh, Hsin-Hsin; Hsieh, Kun-Yang

    2017-05-10

    The traditional white-light light-emitting diode (LED) is packaged with a single chip and a single phosphor but has a poor color rendering index (CRI). The next-generation package comprises two chips and a single phosphor, has a high CRI, and retains high luminous efficacy. This study employs two chips and two phosphors to improve the diode's color tunability with various proportions of two phosphors and various densities of phosphor in the silicone used. A color design model is established for color fine-tuning of the white-light LED module. The maximum difference between the measured and color-design-model simulated CIE 1931 color coordinates is approximately 0.0063 around a correlated color temperature (CCT) of 2500 K. This study provides a rapid method to obtain the color fine-tuning of a white-light LED module with a high CRI and luminous efficacy.

  2. Improving patient access to videofluoroscopy services: Role of the practitioner-led clinic

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Roger D., E-mail: Roger.Newman@lthtr.nhs.uk [Dept. of Speech and Language Therapy, Lancashire Teaching Hospitals, Sharoe Green lane, Fulwood, Preston PR2 9HT (United Kingdom); University of Salford (United Kingdom); Nightingale, Julie [University of Salford (United Kingdom)

    2011-11-15

    Quality Issue: Although costly and time consuming, videofluoroscopic swallowing (VFS) examinations are the gold standard for imaging of oro-pharyngeal dysphagia, and demand is likely to increase with an ageing population. Traditional radiologist-led VFS services in the UK are gradually being replaced by practitioner-led clinics undertaken jointly by speech and language therapists and radiographers. This article explores the impact on patient access of a practitioner-led VFS clinic at a large teaching hospital. Initial Assessment: Specific information pertaining to VFS patient waiting times and service quality was collected for a twelve month period both pre- and post-clinic formation. Choice of Solution: Additional capacity was achieved with the introduction of the practitioner-led clinic, with overall patient access improving by 111%. Mean waiting times for in-patients reduced by 75%, many of whom had the procedure on the same day as referral, with out-patients waiting times reducing by 62.5%. Evaluation: The data demonstrates that patient access and report turnaround times are significantly improved, with no adverse effects as measured by inadequate studies, incorrect reports, complaints and documented radiation dose levels. Lessons Learnt: Practitioner-led VFS services can be recommended as a safe and efficient method of improving service provision.

  3. Improving patient access to videofluoroscopy services: Role of the practitioner-led clinic

    International Nuclear Information System (INIS)

    Newman, Roger D.; Nightingale, Julie

    2011-01-01

    Quality Issue: Although costly and time consuming, videofluoroscopic swallowing (VFS) examinations are the gold standard for imaging of oro-pharyngeal dysphagia, and demand is likely to increase with an ageing population. Traditional radiologist-led VFS services in the UK are gradually being replaced by practitioner-led clinics undertaken jointly by speech and language therapists and radiographers. This article explores the impact on patient access of a practitioner-led VFS clinic at a large teaching hospital. Initial Assessment: Specific information pertaining to VFS patient waiting times and service quality was collected for a twelve month period both pre- and post-clinic formation. Choice of Solution: Additional capacity was achieved with the introduction of the practitioner-led clinic, with overall patient access improving by 111%. Mean waiting times for in-patients reduced by 75%, many of whom had the procedure on the same day as referral, with out-patients waiting times reducing by 62.5%. Evaluation: The data demonstrates that patient access and report turnaround times are significantly improved, with no adverse effects as measured by inadequate studies, incorrect reports, complaints and documented radiation dose levels. Lessons Learnt: Practitioner-led VFS services can be recommended as a safe and efficient method of improving service provision.

  4. Mathematics, Science and the Cambridge Tradition

    OpenAIRE

    Nuno Ornelas Martins

    2012-01-01

    Copyright © 2012 World Economics Association. In this paper the use of mathematics in economics will be discussed, by comparing two approaches to mathematics, a Cartesian approach, and a Newtonian approach. I will argue that while mainstream economics is underpinned by a Cartesian approach which led to a divorce between mathematics and reality, the contributions of key authors of the Cambridge tradition, like Marshall, Keynes and Sraffa, are characterised by a Newtonian approach to mathema...

  5. 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.

  6. 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.

  7. 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.

  8. Characterising and testing deep UV LEDs for use in space applications

    International Nuclear Information System (INIS)

    Hollington, D; Baird, J T; Sumner, T J; Wass, P J

    2015-01-01

    Deep ultraviolet (DUV) light sources are used to neutralise isolated test masses in highly sensitive space-based gravitational experiments. An example is the LISA Pathfinder charge management system, which uses low-pressure mercury lamps. A future gravitational-wave observatory such as eLISA will use UV light-emitting diodes (UV LEDs), which offer numerous advantages over traditional discharge lamps. Such devices have limited space heritage but are now available from a number of commercial suppliers. Here we report on a test campaign that was carried out to quantify the general properties of three types of commercially available UV LEDs and demonstrate their suitability for use in space. Testing included general electrical and UV output power measurements, spectral stability, pulsed performance and temperature dependence, as well as thermal vacuum, radiation and vibration survivability. (paper)

  9. Characterising and testing deep UV LEDs for use in space applications

    Science.gov (United States)

    Hollington, D.; Baird, J. T.; Sumner, T. J.; Wass, P. J.

    2015-12-01

    Deep ultraviolet (DUV) light sources are used to neutralise isolated test masses in highly sensitive space-based gravitational experiments. An example is the LISA Pathfinder charge management system, which uses low-pressure mercury lamps. A future gravitational-wave observatory such as eLISA will use UV light-emitting diodes (UV LEDs), which offer numerous advantages over traditional discharge lamps. Such devices have limited space heritage but are now available from a number of commercial suppliers. Here we report on a test campaign that was carried out to quantify the general properties of three types of commercially available UV LEDs and demonstrate their suitability for use in space. Testing included general electrical and UV output power measurements, spectral stability, pulsed performance and temperature dependence, as well as thermal vacuum, radiation and vibration survivability.

  10. The commercialization of traditional medicine in modern Cambodia.

    Science.gov (United States)

    Ros, Bandeth; Lê, Gillian; McPake, Barbara; Fustukian, Suzanne

    2018-01-01

    Globally, traditional medicine has long been used to address relatively common illness, mental ill health and during childbirth and post-natal care. However, traditional medicine is primarily provided by the private sector and it is unclear how far expenditures on traditional medicine contribute to household impoverishment. A life history method was used to understand the health seeking experience of 24 households over the last 60 years in Cambodia, a country with high out-of-pocket expenditures for health. The life histories suggest that traditional medicine in Cambodia has been undergoing a process of commercialization, with significant impacts on poor households. In the earlier lives of respondents, payments for traditional medicine were reported to have been flexible, voluntary or appropriate to patients' financial means. In contrast, contemporary practitioners appear to seek immediate cash payments that have frequently led to considerable debt and asset sales by traditional medicine users. Given traditional medicine's popularity as a source of treatment in Cambodia and its potential to contribute to household impoverishment, we suggest that it needs to be included in a national conversation about achieving Universal Health Coverage in the country. © The Author 2017. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine.

  11. Effective recruitment of minority populations through community-led strategies.

    Science.gov (United States)

    Horowitz, Carol R; Brenner, Barbara L; Lachapelle, Susanne; Amara, Duna A; Arniella, Guedy

    2009-12-01

    Traditional research approaches frequently fail to yield representative numbers of people of color in research. Community-based participatory research (CBPR) may be an important strategy for partnering with and reaching populations that bear a greater burden of illness but have been historically difficult to engage. The Community Action Board, consisting of 20 East Harlem residents, leaders, and advocates, used CBPR to compare the effectiveness of various strategies in recruiting and enrolling adults with prediabetes into a peer-led, diabetes prevention intervention. The board created five recruitment strategies: recruiting through clinicians; recruiting at large public events such as farmers markets; organizing special local recruitment events; recruiting at local organizations; and recruiting through a partner-led approach, in which community partners developed and managed the recruitment efforts at their sites. In 3 months, 555 local adults were approached; 249 were appropriate candidates for further evaluation (overweight, nonpregnant, East Harlem residents without known diabetes); 179 consented and returned in a fasting state for 1/2 day of prediabetes testing; 99 had prediabetes and enrolled in a pilot randomized trial. The partner-led approach was highly successful, recruiting 68% of those enrolled. This strategy was also the most efficient; 34% of those approached through partners were ultimately enrolled, versus 0%-17% enrolled through the other four strategies. Participants were predominantly low-income, uninsured, undereducated, Spanish-speaking women. This CBPR approach highlights the value of partner-led recruitment to identify, reach out to, and motivate a vulnerable population into participation in research, using techniques that may be unfamiliar to researchers but are nevertheless rigorous and effective.

  12. 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...

  13. 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....

  14. Investigation of structure in the modular light pipe component for LED automotive lamp

    Science.gov (United States)

    Chen, Hsi-Chao; Zhou, Yang; Huang, Chien-Sheng; Jhong, Wan-Ling; Cheng, Bo-Wei; Jhang, Jhe-Ming

    2014-09-01

    Light-Emitting Diodes (LEDs) have the advantages of small length, long lifetime, fast response time (μs), low voltage, good mechanical properties and environmental protection. Furthermore, LEDs could replace the halogen lamps to avoid the mercury pollution and economize the use of energy. Therefore, the LEDs could instead of the traditional lamp in the future and became an important light source. The proposal of this study was to investigate the effects of the structure and length of the reflector component for a LED automotive lamp. The novel LED automotive lamp was assembled by several different modularization columnar. The optimized design of the different structure and the length to the reflector was simulated by software TracePro. The design result must met the vehicle regulation of United Nations Economic Commission for Europe (UNECE) such as ECE-R19 etc. The structure of the light pipe could be designed by two steps structure. Then constitute the proper structure and choose different power LED to meet the luminous intensity of the vehicle regulation. The simulation result shows the proper structure and length has the best total luminous flux and a high luminous efficiency for the system. Also, the stray light could meet the vehicle regulation of ECE R19. Finally, the experimental result of the selected structure and length of the light pipe could match the simulation result above 80%.

  15. 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.

    2016-09-01

    At present, broadband radiometric LED measurements 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.

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

    Science.gov (United States)

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

    2014-06-01

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

  17. 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

  18. 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.

  19. LED-roulette : LED's vervangen balletje

    NARCIS (Netherlands)

    Goossens, P.

    2007-01-01

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

  20. The Use of Ultra-Violet (UV) Light Emitting Diodes (LEDS) in an Advanced Oxidation Process (AOP) with Brilliant Blue FCF as an Indicator

    Science.gov (United States)

    2015-03-26

    LEDs have the potential to replace mercury lamps in many UV processes, as well as open the door to new applications of UV light based on their unique...al. 2007, Autin, Romelot, et al. 2013). UV LEDs in AOPs While most data on AOP experimentation are based on experiments that use mercury lamps ...metaldehyde in solution. Their experiments found that similar UV light exposure levels from UV LEDs and traditional mercury lamps produced similar

  1. Development of Local-Economic-Development Small and Medium Industries (Led-Sme In East Java

    Directory of Open Access Journals (Sweden)

    Rachmad Hidayat

    2013-04-01

    Full Text Available This paper presents the effects of Indonesian government’s developmental efforts of assistance and training performed  on the growth of LED-SME business units and business performance. Both parameters of the government’s assistance and training were used to analyze the impact to the  growth and performance of business unit. To achieve a comprehensive result, samples acquired in this research were about 190 entrepreneurs and managers of LED-SME from East Java. Based on the parameters above, there are five hypotheses made to prove the relationship of the assistance and training to the growth and performance of business units. The structural equation modeling (SEM was carried out to test the hypotheses. The results have shown that the government’s developmental efforts through both assistance and training for the LED-SME were capable on increasing growth and performance of business units. On the other hand, government’s developmental efforts through only trainings were incapable of directly affecting growth of LED-SME business units and performance. To improve the business unit and performance, the government needs to implement developmental principles of LED-SME with the basis of utilizing local natural resources and also the communities of LED-SME as main suppliers for their local markets. In addition, preservation and development of local cultural and traditional arts also need to be the government’s main concern. 

  2. 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....

  3. Color homogeneity in LED spotlights

    NARCIS (Netherlands)

    Prins, C.R.

    2013-01-01

    Color variation in the light output of white LEDs is a common problem in LED lighting. We aim to design LED spotlights with a uniform color output while keeping the cost of the system low and the energy efficiency high. Therefore we design a special optic to eliminate the color variation of the LED.

  4. A Psychometric Evaluation of the Danish Version of the Theory of Mind Storybook for 8-14 Year-Old Children.

    Science.gov (United States)

    Clemmensen, Lars; Bartels-Velthuis, Agna A; Jespersen, Rókur Av F; van Os, Jim; Blijd-Hoogewys, Els M A; Ankerstrøm, Lise; Væver, Mette; Daniel, Peter F; Drukker, Marjan; Jeppesen, Pia; Jepsen, Jens R M

    2016-01-01

    Theory-of-Mind (ToM) keeps on developing in late childhood and early adolescence, and the study of ToM development later in childhood had to await the development of sufficiently sensitive tests challenging more mature children. The current study aimed to investigate the psychometric properties of the Danish version of the Theory-of-Mind Storybook Frederik (ToM-Frederik). We assessed whether ToM-Frederik scores differed between a group of 41 typically developing (TD) children and a group of 33 children with High Functioning Autism Spectrum Disorder (HFASD). A lower mean ToM-Frederik score was expected in the HFASD group. To determine the convergent validity of ToM-Frederik, potential associations with Strange Stories and Animated Triangles (AT) were analyzed. Furthermore, potential associations between ToM-Frederik and the Social Responsiveness Scale (SRS) and between ToM-Frederik and the Social Emotional Evaluation (SEE) Total score were analyzed. A significantly higher ToM-Frederik score was observed in the TD group compared to the HFASD group. Furthermore, the convergent validity of ToM-Frederik as a measure of ToM was supported by significant and positive associations with the Strange Stories and the AT scores in the HFASD group, whereas ToM-Frederik was significantly correlated with Strange Stories, but not with AT in the TD group. ToM-Frederik was not significantly associated with SRS in neither the HFASD nor the TD group. The findings are supportive of ToM-Frederik as a valid indicator of deficits at the group level in children with HFASD between 7 and 14 years of age. Furthermore, the convergent validity is supported.

  5. Traditional Wooden Architecture and Landscape in Karelia. Methodological considerations for the analysis and census

    Directory of Open Access Journals (Sweden)

    Sandro Parinello

    2012-11-01

    Full Text Available The survey work on the Karelian landscape and traditional architecture, embedded within the European research project entitled "Wooden Architecture. Karelian Timber Traditional Architecture and Landscape", is intended to enable understanding of how Karelian culture and history have led, over time, unique urban landscapes. The context of transformation, in which they were involved in both the behavioral habits of local populations both traditional architectural ones, which are mixed with models and with the administrative Soviet structures, were analyzed in this scientific field in order to not compromise the conservation and enhancement of the historic, architectural and landscape of this country.

  6. LED Technology for Dental Applications

    DEFF Research Database (Denmark)

    Argyraki, Aikaterini; Ou, Yiyu; Soerensen, L. H.

    LEDs have a large potential in many dental and oral applications. Areas such as photo polymerization, fluorescence imaging, photodynamic therapy, and photoactivated disinfection are important future candidates for LED based diagnostics and treatment in dentistry.......LEDs have a large potential in many dental and oral applications. Areas such as photo polymerization, fluorescence imaging, photodynamic therapy, and photoactivated disinfection are important future candidates for LED based diagnostics and treatment in dentistry....

  7. Broadband Radiometric LED Measurements

    OpenAIRE

    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(��) 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 irr...

  8. 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.

  9. Traditionalism or Traditiona-Lieism: Authentication or Fabrication?

    Directory of Open Access Journals (Sweden)

    Abeer Hussam Eddin Al-Lahham

    2014-11-01

    Full Text Available Muslim cities with their notable architecture and morphology have always attracted scholars, architects, and planners. Regionalism, Historicism, Neo-Traditionalism, and Revivalism are but a few postmodern approaches that emerged calling for reviving the spirit of the place and searching for an identity associated with history and context. Structuralism, Semiology and Critical Studies offered significant methodologies in this respect. This research argues that traditional Islamic built environment has its own structures stemmed from Shari’a (Islamic legal system, which gave it its authenticity. Similarly, contemporary built environment has its own structures based on capitalism and its mechanisms. Those two modes (Islam and capitalism are substantially different, and hence their structures. Adopting linguistic methodologies, Revivalism of Islamic heritage, or Traditionalism, is in effect imposing solutions originated in one mode onto another. This led to internal contradictions in the structures of contemporary built environment and thus to a state of in-equilibrium that might be depicted as a crisis. Therefore, the process of “authentication” of contemporary built environment turned out to be a “fabrication” of contemporary Islamic architecture. It is thus “Traditiona-lieism.”

  10. Plant growth regulation by the light of LEDs; LED ko wo tsukatta shokubutsu saibai gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, H. [Mitsubishi Chemical Co., Tokyo (Japan). Yokohama Research Center

    1996-03-01

    Light Emitting Diode (LED) has not only an excellent display function for the luminescent device but also a superior feature without other lamps as light source for plant growth. It was National Aeronautics and Space Administration (NASA) to find out such merit for this light source for plant growth and try at first to use for plant growth at the space. They began to examine the LED application to the light source for the plant growth at the space since a stage at high cost of the LED, to develop some researches centered at cultivation of lettuce, wheat, and others. Finding out future possibility of cost-down of the LEDs on the cost/performance and large merits of the LEDs for control of the plant growth and plant physiology, authors have conducted some cultivation experiments of the plants using the LEDs for light source some years ago. In this papers, characterizations, actual possibility, and future developments of the LEDs for the light sources of the plant growth, are introduced. 5 refs., 4 figs.

  11. Visible light communication based vehicle positioning using LED street light and rolling shutter CMOS sensors

    Science.gov (United States)

    Do, Trong Hop; Yoo, Myungsik

    2018-01-01

    This paper proposes a vehicle positioning system using LED street lights and two rolling shutter CMOS sensor cameras. In this system, identification codes for the LED street lights are transmitted to camera-equipped vehicles through a visible light communication (VLC) channel. Given that the camera parameters are known, the positions of the vehicles are determined based on the geometric relationship between the coordinates of the LEDs in the images and their real world coordinates, which are obtained through the LED identification codes. The main contributions of the paper are twofold. First, the collinear arrangement of the LED street lights makes traditional camera-based positioning algorithms fail to determine the position of the vehicles. In this paper, an algorithm is proposed to fuse data received from the two cameras attached to the vehicles in order to solve the collinearity problem of the LEDs. Second, the rolling shutter mechanism of the CMOS sensors combined with the movement of the vehicles creates image artifacts that may severely degrade the positioning accuracy. This paper also proposes a method to compensate for the rolling shutter artifact, and a high positioning accuracy can be achieved even when the vehicle is moving at high speeds. The performance of the proposed positioning system corresponding to different system parameters is examined by conducting Matlab simulations. Small-scale experiments are also conducted to study the performance of the proposed algorithm in real applications.

  12. Color homogeneity in LED spotlights

    NARCIS (Netherlands)

    Prins, C.R.; Tukker, T.W.; IJzerman, W.L.; Thije Boonkkamp, ten J.H.M.

    2014-01-01

    LED is a rising technology in the field of lighting. Halogen spotlights are nowadays replaced by LED spotlights because of their energy efficiency and long lifetime. However, color variation in the light output is a common problem. Poorly designed LED spotlights tend to have yellowish or bluish

  13. 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.

  14. Are nurse-led chemotherapy clinics really nurse-led? : an ethnographic study

    OpenAIRE

    Farrell, Carole; Walshe, Catherine Elizabeth; Molassiotis, Alex

    2017-01-01

    Background: 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. Ob...

  15. Design of multisegmented freeform lens for LED fishing/working lamp with high efficiency.

    Science.gov (United States)

    Lai, Min-Feng; Anh, Nguyen Doan Quoc; Gao, Jia-Zhi; Ma, Hsin-Yi; Lee, Hsiao-Yi

    2015-10-01

    A novel LED fishing/working light is proposed to enhance the lighting efficiency of a fishing boat. The study is focused on the freeform secondary lens design so as to create a lamp that attracts fish and sheds light on the deck for the crew's work. The experimental results show that the proposed multisegmented freeform lens can deliver the proposed aim, giving 3 times as much illuminating power as the traditional high-intensity discharge fishing lamp does with the same input of electrical power.

  16. 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

  17. Educating Prisoners of Tradition: Visual Narratives of Afghan Women on Social Media

    Science.gov (United States)

    Jelodar, Esmaeil Zeiny; Hashim, Ruzy Suliza; Yusof, Noraini Md; Raihanah, M. M.; Hamdan, Shahizah Ismail; Zandi, Peivand

    2014-01-01

    More than a decade after the US-led intervention of Afghanistan, traditional and tribal customs still play a significant role in the everyday lives of people, especially women. History has proven that women have been playing a significant role in shaping the course of Afghanistan but unfortunately, they are always subjected to different degrees of…

  18. A Psychometric Evaluation of the Danish Version of the Theory of Mind Storybook for 8–14 Year-Old Children

    Science.gov (United States)

    Clemmensen, Lars; Bartels-Velthuis, Agna A.; Jespersen, Rókur av F.; van Os, Jim; Blijd-Hoogewys, Els M. A.; Ankerstrøm, Lise; Væver, Mette; Daniel, Peter F.; Drukker, Marjan; Jeppesen, Pia; Jepsen, Jens R. M.

    2016-01-01

    Background: Theory-of-Mind (ToM) keeps on developing in late childhood and early adolescence, and the study of ToM development later in childhood had to await the development of sufficiently sensitive tests challenging more mature children. The current study aimed to investigate the psychometric properties of the Danish version of the Theory-of-Mind Storybook Frederik (ToM-Frederik). Methods: We assessed whether ToM-Frederik scores differed between a group of 41 typically developing (TD) children and a group of 33 children with High Functioning Autism Spectrum Disorder (HFASD). A lower mean ToM-Frederik score was expected in the HFASD group. To determine the convergent validity of ToM-Frederik, potential associations with Strange Stories and Animated Triangles (AT) were analyzed. Furthermore, potential associations between ToM-Frederik and the Social Responsiveness Scale (SRS) and between ToM-Frederik and the Social Emotional Evaluation (SEE) Total score were analyzed. Results: A significantly higher ToM-Frederik score was observed in the TD group compared to the HFASD group. Furthermore, the convergent validity of ToM-Frederik as a measure of ToM was supported by significant and positive associations with the Strange Stories and the AT scores in the HFASD group, whereas ToM-Frederik was significantly correlated with Strange Stories, but not with AT in the TD group. ToM-Frederik was not significantly associated with SRS in neither the HFASD nor the TD group. Conclusion: The findings are supportive of ToM-Frederik as a valid indicator of deficits at the group level in children with HFASD between 7 and 14 years of age. Furthermore, the convergent validity is supported. PMID:27014139

  19. Medical Decision-Making Among Elderly People in Long Term Care.

    Science.gov (United States)

    Tymchuk, Alexander J.; And Others

    1988-01-01

    Presented informed consent information on high and low risk medical procedures to elderly persons in long term care facility in standard, simplified, or storybook format. Comprehension was significantly better for simplified and storybook formats. Ratings of decision-making ability approximated comprehension test results. Comprehension test…

  20. ‘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......-2005. Even after 15 days of illumination, no effect was observed. So this LED-based solution was demonstrated to be a very promising light source for photolithography room illumination due to its better color rendering in addition to energy efficiency, long life time and design flexibility. Additionally......, and the prototype was fabricated. The spectral power distribution of both the LED bulb and the yellow fluorescent tube was measured. Based on that, colorimetric values were calculated and compared on terms of chromatic coordinates, correlated color temperature, color rendering index, and chromatic deviation...

  1. A psychometric evaluation of the Danish version of the Theory of Mind Storybook for 8-14 year-old children.

    Directory of Open Access Journals (Sweden)

    Lars eClemmensen

    2016-03-01

    Full Text Available Abstract Background Theory-of-Mind (ToM keeps on developing in late childhood and early adolescence, and the study of ToM development later in childhood had to await the development of sufficiently sensitive tests challenging more mature children. The current study aimed to investigate the psychometric properties of the Danish version of the Theory-of-Mind Storybook Frederik (ToM-Frederik. Methods We assessed whether ToM-Frederik scores differed between a group of 41 typically developing (TD children and a group of 33 children with High functioning Autism Spectrum Disorder (HFASD. A lower mean ToM-Frederik score was expected in the HFASD group. To determine the convergent validity of ToM-Frederik, potential associations with Strange Stories and Animated Triangles (AT were analyzed. Furthermore, potential associations between ToM-Frederik and the Social Responsiveness Scale (SRS and between ToM-Frederik and the Social Emotional Evaluation (SEE Total score were analyzed. Results A significantly higher ToM-Frederik score was observed in the TD group compared to the HFASD group. Furthermore, the convergent validity of ToM-Frederik as a measure of ToM was supported by significant and positive associations with the Strange Stories and the AT scores in the HFASD group, whereas ToM-Frederik was significantly correlated with Strange Stories, but not with AT in the TD group. ToM-Frederik was not significantly associated with SRS in neither the HFASD nor the TD group.Conclusion The findings are supportive of ToM-Frederik as a valid indicator of deficits at the group level in children with HFASD between 7 and 14 years of age. Furthermore, the convergent validity is supported.

  2. 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

  3. Local Government and Traditional Authorities in Concert: Towards a More Productive Relationship

    Directory of Open Access Journals (Sweden)

    Callistus Mahama

    2009-11-01

    Full Text Available Ghana embarked on decentralisation in 1988 as a way of bringing decision making closer to the people. Since then, there have several reforms with a view to strengthening local governance. This article identifies a major challenge still facing Ghana’s decentralisation: Partnership between local government and traditional authorities. The paper discusses the fuzzy relationship between local governments and traditional authorities as a result of constitutional and legislative ambiguity on their relationship. Traditional Authorities perform important functions in the country, albeit their roles have waned since independence. Yet current legal provisions on local government have not sufficiently clarified their role in local administration. This has led to a murky and competing relationship between traditional authorities and local governments. In localities where mutual relationship exists, it is mainly as a result of the personalities involved and this has had a positive effect on the development of the area. The paper concludes by advocating for measures which among others include a re-enactment of legislation which will define the working relationship between traditional authorities and local government.

  4. Comparative analysis of profitability of honey production using traditional and box hives.

    Science.gov (United States)

    Al-Ghamdi, Ahmed A; Adgaba, Nuru; Herab, Ahmed H; Ansari, Mohammad J

    2017-07-01

    Information on the profitability and productivity of box hives is important to encourage beekeepers to adopt the technology. However, comparative analysis of profitability and productivity of box and traditional hives is not adequately available. The study was carried out on 182 beekeepers using cross sectional survey and employing a random sampling technique. The data were analyzed using descriptive statistics, analysis of variance (ANOVA), the Cobb-Douglas (CD) production function and partial budgeting. The CD production function revealed that supplementary bee feeds, labor and medication were statistically significant for both box and traditional hives. Generally, labor for bee management, supplementary feeding, and medication led to productivity differences of approximately 42.83%, 7.52%, and 5.34%, respectively, between box and traditional hives. The study indicated that productivity of box hives were 72% higher than traditional hives. The average net incomes of beekeepers using box and traditional hives were 33,699.7 SR/annum and 16,461.4 SR/annum respectively. The incremental net benefit of box hives over traditional hives was nearly double. Our study results clearly showed the importance of adoption of box hives for better productivity of the beekeeping subsector.

  5. Comparative analysis of profitability of honey production using traditional and box hives

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Ghamdi

    2017-07-01

    Full Text Available Information on the profitability and productivity of box hives is important to encourage beekeepers to adopt the technology. However, comparative analysis of profitability and productivity of box and traditional hives is not adequately available. The study was carried out on 182 beekeepers using cross sectional survey and employing a random sampling technique. The data were analyzed using descriptive statistics, analysis of variance (ANOVA, the Cobb-Douglas (CD production function and partial budgeting. The CD production function revealed that supplementary bee feeds, labor and medication were statistically significant for both box and traditional hives. Generally, labor for bee management, supplementary feeding, and medication led to productivity differences of approximately 42.83%, 7.52%, and 5.34%, respectively, between box and traditional hives. The study indicated that productivity of box hives were 72% higher than traditional hives. The average net incomes of beekeepers using box and traditional hives were 33,699.7 SR/annum and 16,461.4 SR/annum respectively. The incremental net benefit of box hives over traditional hives was nearly double. Our study results clearly showed the importance of adoption of box hives for better productivity of the beekeeping subsector.

  6. A Hybrid Integrated Laboratory and Inquiry-Based Research Experience: Replacing Traditional Laboratory Instruction with a Sustainable Student-Led Research Project

    Science.gov (United States)

    Hartings, Matthew R.; Fox, Douglas M.; Miller, Abigail E.; Muratore, Kathryn E.

    2015-01-01

    The Department of Chemistry at American University has replaced its junior- and senior-level laboratory curriculum with two, two-semester long, student-led research projects as part of the department's American Chemical Society-accredited program. In the first semester of each sequence, a faculty instructor leads the students through a set of…

  7. 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

  8. Peer-led versus teacher-led AIDS education for female high-school students in Yazd, Islamic Republic of Iran.

    Science.gov (United States)

    Baghianimoghadam, M H; Forghani, H; Zolghadr, R; Rahaei, Z; Khani, P

    2012-04-01

    Peer-led programmes on AIDS prevention have shown a good level of effectiveness when tested among high-risk populations. This study compared peer-led and teacher-led methods of education about HIV/AIDS among female high-school students in Yazd city, Islamic Republic of Iran. In 2009 students in 3 high schools were trained by their classmates (peer-led), by the research team (teacher-led) or had no education (controls); 180 students completed a specially designed questionnaire based on the health belief model, before and after the intervention. Post-intervention mean knowledge scores increased 2-fold in the peer-led group, and this was significantly higher than the increase in the teacher-led group scores (1.5-fold). Control group scores were unchanged. In the peer-led programme all of the components of the model were significantly improved whereas in the teacher-led programme, only perceived severity and perceived barriers scored significantly higher after the intervention.

  9. A new approach to preparation of standard LEDs for luminous intensity and flux measurement of LEDs

    Science.gov (United States)

    Park, Seung-Nam; Park, Seongchong; Lee, Dong-Hoon

    2006-09-01

    This work presents an alternative approach for preparing photometric standard LEDs, which is based on a novel functional seasoning method. The main idea of our seasoning method is simultaneously monitoring the light output and the junction voltage to obtain quantitative information on the temperature dependence and the aging effect of the LED emission. We suggested a general model describing the seasoning process by taking junction temperature variation and aging effect into account and implemented a fully automated seasoning facility, which is capable of seasoning 12 LEDs at the same time. By independent measurements of the temperature dependence, we confirmed the discrepancy of the theoretical model to be less than 0.5 % and evaluate the uncertainty contribution of the functional seasoning to be less than 0.5 % for all the seasoned samples. To demonstrate assigning the reference value to a standard LED, the CIE averaged LED intensity (ALI) of the seasoned LEDs was measured with a spectroradiometer-based instrument and the measurement uncertainty was analyzed. The expanded uncertainty of the standard LED prepared by the new approach amounts to be 4 % ~ 5 % (k=2) depending on color without correction of spectral stray light in the spectroradiometer.

  10. 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.)

  11. Mothering from Prison: Using Narratives in a Mother-Child Support Program

    Science.gov (United States)

    Trost, Betty Chamness

    2009-01-01

    Incarcerated and formerly incarcerated women who participated in the Storybook Project of Iowa told passionate stories of how their understanding of mothering had changed. They spoke of how the Storybook Project strengthened their mothering practices and relationships with their children and families. This study was an opportunity for reflection…

  12. 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.

  13. The health risks associated with energy efficient fluorescent, LEDs, and artificial lighting

    Science.gov (United States)

    Panahi, Allen

    2014-09-01

    With the phasing out of incandescent lamps in many countries, the introduction of new LED based light sources and luminaries sometimes raise the question of whether the spectral characteristics of the LED and other energy savings Fluorescent lights including the popular CFLs are suitable to replace the traditional incandescent lamps. These concerns are sometimes raised particularly for radiation emissions in the UV and Blue parts of the spectrum. This paper aims to address such concerns for the common `white light' sources typically used in household and other general lighting used in the work place. Recent studies have shown that women working the night shift have an increased probability of developing breast cancer. We like to report on the findings of many studies done by medical professionals, in particular the recent announcement of AMA in the US and many studies conducted in the UK, as well as the European community to increase public awareness on the long term health risks of the optical and opto-biological effects on the human health caused by artificial lighting.

  14. Verbaalne soolo Jaanus Nõgistolt : Led R-ist, Narva Linna Sümfooniaorkestrist ja Led Zeppelinist / Jaanus Nõgisto ; interv. Margo Pajuste

    Index Scriptorium Estoniae

    Nõgisto, Jaanus, 1956-

    2007-01-01

    Rockansambli Led Zeppelini muusikast, ansamblist Led R ja heliplaadist "Led the R Out" räägib kitarrist Jaanus Nõgisto. Led R ja Narva Linna Sümfooniaorkestri kontserdid: 22. juunil Pärnus ja 14. juulil Haapsalu lossihoovis, ansambli Led R kontsert koos Havana Blackiga 3. aug. Sõru sadamas Hiiumaal

  15. Heat Transfer Characteristics in High Power LED Packaging

    Directory of Open Access Journals (Sweden)

    Chi-Hung Chung

    2014-03-01

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

  16. Vocabulary Acquisition without Adult Explanations in Repeated Shared Book Reading: An Eye Movement Study

    Science.gov (United States)

    Evans, Mary Ann; Saint-Aubin, Jean

    2013-01-01

    When preschoolers listen to storybooks, are their eye movements related to their vocabulary acquisition in this context? This study addressed this question with 36 four-year-old French-speaking participants by assessing their general receptive vocabulary knowledge and knowledge of low-frequency words in 3 storybooks. These books were read verbatim…

  17. Electronic Books: Children's Reading and Comprehension

    Science.gov (United States)

    Grimshaw, Shirley; Dungworth, Naomi; McKnight, Cliff; Morris, Anne

    2007-01-01

    This study investigates the differences in children's comprehension and enjoyment of storybooks according to the medium of presentation. Two different storybooks were used and 132 children participated. Of these, 51 children read an extract from "The Magicians of Caprona," about half reading an electronic version with an online dictionary, and the…

  18. 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

    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...... 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...

  19. Literacy Development in Multicultural Settings with Digital Dual-language Books

    Directory of Open Access Journals (Sweden)

    Yıldız Turgut

    2011-10-01

    Full Text Available Problem Statement: Providing a story in two languages, digital dual-language storybooks can play an important role in supporting EFL students‟ cultural awareness, language and literacy skills. Based on constructivist theoretical framework, this study investigates the impact of digital dual-language storybooks on bilingual learners‟ vocabulary knowledge and reading comprehension skills.Methods: The participants of the study were ten seventh and eighth grade students who were bilingual in Arabic and Turkish, studying English at an elementary level as a compulsory course at a primary school in Turkey. In order to determine the impact of digital dual-language storybooks, the students read two different digital dual-language storybooks individually at different times. Through the process, think aloud procedures, observations and semi-structured interviews were conducted. Transcriptions of observations and interviews were analyzed through discourse analysis.Findings and Results: The results of the study indicated that the use of dual language books have a significant impact on learners‟ vocabulary knowledge growth. Using digital dual-language storybooks, learners can develop some strategies for learning new words, make use of images in comprehending the story and engage eagerly to the stories as they reflect and value their own culture and heritage.Conclusions and Recommendations: Awareness about new language systems, diversity and multiculturality in learners‟ immediate environment can be raised.

  20. Ethnomedicinal plants used by traditional healers in Phatthalung Province, Peninsular Thailand.

    Science.gov (United States)

    Maneenoon, Katesarin; Khuniad, Chuanchom; Teanuan, Yaowalak; Saedan, Nisachon; Prom-In, Supatra; Rukleng, Nitiphol; Kongpool, Watid; Pinsook, Phongsura; Wongwiwat, Winyu

    2015-05-30

    In rural communities of Thailand, traditional healers still play an important role in local health care systems even though modern medicine is easily accessible. Meanwhile, natural forests in Thailand which are important sources of materia medica are being greatly destroyed. This has led to an erosion of traditional Thai medicine. Furthermore, the concept of medicinal plant selection as medicine based on their tastes is still an important component of traditional Thai medicine, but no or little publications have been reported. Thus the aim of the present study is to collect ethnomedicinal data, medicinal plant tastes and relevant information from experienced traditional healers before they are lost. An ethnobotanical survey was carried out to collect information from nine experienced traditional healers on the utilization of medicinal plants in Phatthalung Province, Peninsular Thailand. Data were obtained using semi-structured interviews and participant observations. Plant specimens were also collected and identified according to the plant taxonomic method. A total of 151 medicinal plants were documented and 98 of these are reported in the study. Local names, medicinal uses, parts used, modes of preparation, and the relationship between ailments and tastes of medicinal plant species are presented. This research suggests that traditional healers are still considered important for public health among Thai communities and that many people trust the healing properties of medicinal plants. In the future, it is hoped that traditional Thai medicine will be promoted and therefore will help reduce national public health expense.

  1. Tracking the Eye Movement of Four Years Old Children Learning Chinese Words

    Science.gov (United States)

    Lin, Dan; Chen, Guangyao; Liu, Yingyi; Liu, Jiaxin; Pan, Jue; Mo, Lei

    2018-01-01

    Storybook reading is the major source of literacy exposure for beginning readers. The present study tracked 4-year-old Chinese children's eye movements while they were reading simulated storybook pages. Their eye-movement patterns were examined in relation to their word learning gains. The same reading list, consisting of 20 two-character Chinese…

  2. 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.

  3. Traditional behaviour and fidelity to caribou calving grounds by barren-ground caribou

    Directory of Open Access Journals (Sweden)

    Anne Gunn

    1986-06-01

    Full Text Available Evidence for the fidelity of female barren-ground caribou (Rangifer tarandus spp. of each herd to specific calving grounds is convincing. Involvement of learned behaviour in the annual return of those cows to the same calving grounds implies such actions are a form of «traditional» behaviour. Even wide variations in population size have not yet knowingly led to marked changes in size or location of calving grounds or prolonged abandonment of established ones. Rarely is the adoption of new calving grounds reported and emigration to another herd's calving ground or interchange between calving grounds has not yet been unequivocally documented. The calving experience of individual caribou and environmental pressures may modify the cow's use patterns of her calving grounds. The current definition of herds based on traditional calving grounds may require modification, if increasing caribou numbers result in changes in traditions. However, current data do not contradict either the fidelity to traditional calving grounds or the concept of herd identity based on that fidelity.

  4. Preschool Children's Exposure to Story Grammar Elements during Parent-Child Book Reading

    Science.gov (United States)

    Breit-Smith, Allison; van Kleeck, Anne; Prendeville, Jo-Anne; Pan, Wei

    2017-01-01

    Twenty-three preschool-age children, 3;6 (years; months) to 4;1, were videotaped separately with their mothers and fathers while each mother and father read a different unfamiliar storybook to them. The text from the unfamiliar storybooks was parsed and coded into story grammar elements and all parental extratextual utterances were transcribed and…

  5. Camels Milk: Nutrition and Health Perspectives Iranian Traditional Medicine

    Directory of Open Access Journals (Sweden)

    Seyyd Musa al-Reza Hosseini

    2015-09-01

    Full Text Available Background: Camel milk is the closest to human mother’s milk. In the references on Iranian traditional medicine, camel’s milk has been represented as the one having numerous nutritious and medical properties.Objectives: In this article, the nutritive and therapeutic effects of camel’s milk have been examined from the view point of Iranian traditional medicine.Materials and Methods: The present study is a qualitative one, which was carried out, based on certain criteria, through purposeful search of certain keywords in the written references of Iranian traditional medicine.Results: Numerous pharmacological functions and therapeutic effects of camel’s milk on patients suffering from liver, kidney, bladder, spleen, stomach and intestines, uterus, skin, lungs, and brain diseases have been mentioned. Camel’s milk seems to be an appropriate alternative/supplement to nourish infants and children.Conclusions: Animal resources, such as camel’s milk and its various products, have comprehensively been dealt with regarding their nutritive and therapeutic effects. Its compatibility with and similarity to mother’s milk have led to its application in pediatrics; thus, offering valid information to pediatricians on camel’s milk can further enhance the consumption of this natural product.

  6. Storybooks aren't just for fun: narrative and non-narrative picture books foster equal amounts of generic language during mother-toddler book sharing.

    Science.gov (United States)

    Nyhout, Angela; O'Neill, Daniela K

    2014-01-01

    Parents and children encounter a variety of animals and objects in the early picture books they share, but little is known about how the context in which these entities are presented influences talk about them. The present study investigated how the presence or absence of a visual narrative context influences mothers' tendency to refer to animals as individual characters or as members of a kind when sharing picture books with their toddlers (mean age 21.3 months). Mother-child dyads shared both a narrative and a non-narrative book, each featuring six animals and matched in terms of length and quantity of text. Mothers made more specific (individual-referring) statements about animals in the narrative books, whereas they provided more labels for animals in the non-narrative books. But, of most interest, the frequency and proportion of mothers' use of generic (kind-referring) utterances did not differ across the two different types of books. Further coding of the content of the utterances revealed that mothers provided more story-specific descriptions of states and actions of the animals when sharing narrative books and more physical descriptions of animals when sharing non-narrative books. However, the two books did not differ in terms of their elicitation of natural facts about the animals. Overall, although the two types of books encouraged different types of talk from mothers, they stimulated generic language and talk about natural facts to an equal degree. Implications for learning from picture storybooks and book genre selection in classrooms and home reading are discussed.

  7. Languaging in and about Lunyole: African Storybook materials as a catalyst for re-imagining literacy teaching and learning in two Ugandan primary schools

    Directory of Open Access Journals (Sweden)

    Juliet Tembe

    2016-07-01

    Full Text Available Throughout sub-Saharan Africa, many children are not learning to read competently in the first 3 years of primary school; thus, both ‘reading to learn’ and ‘reading for pleasure’ in these early years, and in higher grades, are constrained. Two of the many reasons for reading failure are the absence of suitable materials in languages with which learners are familiar and teachers’ limited knowledge of pedagogic practices that support reading development. In this article, we describe the African Storybook (ASb initiative as one imaginative response to the dearth of interesting and accessible stories in local languages and report findings from the first phase of a professional development project in which teacher-researchers in two Ugandan schools are using ASb materials to ‘language’ in Lunyole at the meetings of their action research group. We argue that their investment in extending their literacy in a language which they speak more fluently than they read or write, and the contestations over written forms of this language that have surfaced in some of the discussions, are likely to be productive for their professional development as teachers and for their participation in ongoing community debates about the orthography of a recently codified and standardised language. By languaging together in Lunyole, with ASb materials as the main object of their conversations and activities, the teacher-researchers have begun to develop capabilities that are likely to benefit the Lunyole/ English biliteracy of the learners whom they teach. They are imagining new possibilities for themselves and for the learners.

  8. 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.

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

    Science.gov (United States)

    Grandjean, N.

    2010-09-01

    Generating white light from electricity with maximum efficacy has been a long quest since the first incandescent lamp was invented by Edison at the end of the 19th century. Nowadays, semiconductors are making reality the holy grail of converting electrons into photons with 100% efficiency and with colours that can be mixed for white light illumination. The revolution in solid-state lighting (SSL) dates to 1994 when Nakamura reported the first high-brightness blue LED based on GaN semiconductors. Then, white light was produced by simply combining a blue dye with a yellow phosphor. After more than a decade of intensive research the performance of white LEDs is quite impressive, beating by far the luminous efficacy of compact fluorescent lamps. We are likely close to replacing our current lighting devices by SSL lamps. However, there are still technological and fabrication cost issues that could delay large market penetration of white LEDs. Interestingly, SSL may create novel ways of using light that could potentially limit electricity saving. Whatever the impact of SSL, it will be significant on our daily life. The purpose of this special cluster issue is to produce a snapshot of the current situation of SSL from different viewing angles. In an introductory paper, Tsao and co-workers from Sandia National Laboratories, present an energy-economics perspective of SSL considering societal changes and SSL technology evolution. In a second article, Narukawa et al working at Nichia Corporation—the pioneer and still the leading company in SSL—describe the state of the art of current research products. They demonstrate record performance with white LEDs exhibiting luminous efficacy of 183 lm W-1 at high-current injection. Then, a series of topical papers discuss in detail various aspects of the physics and technology of white LEDs Carrier localization in InGaN quantum wells has been considered the key to white LEDs' success despite the huge density of defects. A

  10. Combined daylight and intelligent LED lighting - getting the daylight into the buildings; Kombineret dagslys og intelligent LED belysning - fae dagslys ind i bygningerne. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Hansen, C.; Corell, D.D.; Thorseth, A.; Behrensdorff Poulsen, P. [Technical Univ. of Denmark, DTU Fotonik, DTU Risoe Campus, Roskilde (Denmark); Markvart, J.; Iversen, A.; Logadottir, A. [Aalborg Univ., Statens Byggeforskningsinstitut (SBi), Koebenhavn (Denmark)

    2013-03-15

    The main result of the project is the construction of the new intelligent and dynamic LED lighting system for demonstration and research purposes, and a number of extensive user testing is completed. The LED lighting system is a total system for office lighting with ceiling fixtures and desk lamps, which has made it possible to create a general and workplace lighting in two offices each with two work places. The system is installed in a day light laboratory for such two office spaces. All lamps can be controlled via a developed computer interface, and the desk lamps are further manually controllable by a user via two buttons for color temperature and brightness, respectively. The new intelligent and dynamic lighting system is based on color mixing LED technology and makes it possible to control the color composition, color coordinates and thus the color temperature of the light. Control-wise, the system is pre-programmed to produce white light with a correlated color temperature from 2700 K to 7000 K. The color composition is optimized from the desire for a very good color given at a general CRI value of 92-97 over the area. The system can be dimmed 20-100 %, with no significant change in the light's color properties. A mini-spectrometer is calibrated and built-in in the system and provides the current estimate of daylight brightness and color temperature through measurement of daylight color scheme in the visible range. The system uses daylight properties to control the light from the LED lighting system. The results of user tests show, that the developed possibility to automatically control of light in the office depending on the daylight color temperature is considered to be equally preferred and results in equally satisfied users as a traditional lighting system with even lighting in the room. On the other hand, user results showed that there were both energy savings and more satisfied users to be gained by providing users the opportunity to self-adjust either

  11. A design of LED adaptive dimming lighting system based on incremental PID controller

    Science.gov (United States)

    He, Xiangyan; Xiao, Zexin; He, Shaojia

    2010-11-01

    As a new generation energy-saving lighting source, LED is applied widely in various technology and industry fields. The requirement of its adaptive lighting technology is more and more rigorous, especially in the automatic on-line detecting system. In this paper, a closed loop feedback LED adaptive dimming lighting system based on incremental PID controller is designed, which consists of MEGA16 chip as a Micro-controller Unit (MCU), the ambient light sensor BH1750 chip with Inter-Integrated Circuit (I2C), and constant-current driving circuit. A given value of light intensity required for the on-line detecting environment need to be saved to the register of MCU. The optical intensity, detected by BH1750 chip in real time, is converted to digital signal by AD converter of the BH1750 chip, and then transmitted to MEGA16 chip through I2C serial bus. Since the variation law of light intensity in the on-line detecting environment is usually not easy to be established, incremental Proportional-Integral-Differential (PID) algorithm is applied in this system. Control variable obtained by the incremental PID determines duty cycle of Pulse-Width Modulation (PWM). Consequently, LED's forward current is adjusted by PWM, and the luminous intensity of the detection environment is stabilized by self-adaptation. The coefficients of incremental PID are obtained respectively after experiments. Compared with the traditional LED dimming system, it has advantages of anti-interference, simple construction, fast response, and high stability by the use of incremental PID algorithm and BH1750 chip with I2C serial bus. Therefore, it is suitable for the adaptive on-line detecting applications.

  12. Tourist orchards: an opportunity for sustainable development tourism in Romanian traditional fruit growing areas

    Directory of Open Access Journals (Sweden)

    Albu, R. G.

    2012-01-01

    Full Text Available The Romanian traditional fruit growing areas are spaces that, given the transition from a centralized economy to a market economy, have accumulated multiple dysfunctions, whose solving requires the identification of viable solutions, matching local potential and preserving traditional specificity at the same time. The article analyzes how the tourist orchard model, developed successfully in China could be implemented in Romanian traditional fruit growing areas. Also the evolution of the Chinese tourist orchard is presented, highlighting the stages of its development and paying special attention to the current stage that witnesses the solid consolidation of the extant niche of tourist orchards, as part of the Chinese tourism. This consolidation has led to several large metropolitan areas (Beijing, Shanghai, Guangzhou and Shenzhen in China standing out on the international market.

  13. Efficacy of embedded nurse-led versus conventional physician-led follow-up in rheumatoid arthritis

    DEFF Research Database (Denmark)

    de Thurah, Annette; Esbensen, Bente Appel; Roelsgaard, Ida Kristiane

    2017-01-01

    difference (SMD) -0.17 (95 % CI -1.0 to 0.67), whereas a statistical significant difference in favour of nurse-led follow-up was seen after 2 years (SMD: 0.6 (95% CI -0.00 to 1.20)). CONCLUSION: After 1 year no difference in disease activity, indicated by DAS-28, were found between embedded nurse-led follow...

  14. Consumers' acceptance of innovations in traditional cheese. A comparative study in France and Norway.

    Science.gov (United States)

    Almli, Valérie Lengard; Naes, Tormod; Enderli, Géraldine; Sulmont-Rossé, Claire; Issanchou, Sylvie; Hersleth, Margrethe

    2011-08-01

    This study explores consumers' acceptance of innovations in traditional cheese in France (n=120) and Norway (n=119). The respondents were presented with 16 photographs of a traditional cheese from their respective countries, varying according to six factors: pasteurisation, organic production, omega-3, packaging, price and appropriateness. For each of the scenarios the consumers indicated their willingness to buy the cheese on a nine-point scale. Results show that consumers' willingness to buy traditional cheese is highly driven by price, appropriateness and pasteurisation in both countries. However, on average consumers in the French sample prefer buying raw milk cheese, while consumers in the Norwegian sample prefer buying pasteurised cheese. These general trends are led by a pro-raw milk segment in France and a pro-pasteurised milk segment in Norway. Several interaction effects involving appropriateness are detected, indicating the importance of the consumption context on the acceptance of innovations in traditional cheese. On a general level, the results indicate that well-accepted innovations in traditional cheese are those that reinforce the traditional and authentic character of the product. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. [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.

  16. Celebrity-led development organisations

    DEFF Research Database (Denmark)

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

    2017-01-01

    The past decade has seen a frontier open up in international development engagement with the entrance of new actors such as celebrity-led organisations. We explore how such organisations earn legitimacy with a focus on Madonna’s Raising Malawi and Ben Affleck’s Eastern Congo Initiative. The study...... for funding, endorsements, and expertise. We argue that the ways in which celebrity-led organisations establish themselves as legitimate development actors illustrate broader dynamics of the machinery of development.......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...

  17. Cryogenic characterization of LEDs for space application

    Science.gov (United States)

    Carron, Jérôme; Philippon, Anne; How, Lip Sun; Delbergue, Audrey; Hassanzadeh, Sahar; Cillierre, David; Danto, Pascale; Boutillier, Mathieu

    2017-09-01

    In the frame of EUCLID project, the Calibration Unit of the VIS (VISible Imager) instrument must provide an accurate and well characterized light source for in-flight instrument calibration without noise when it is switched off. The Calibration Unit consists of a set of LEDs emitting at various wavelengths in the visible towards an integrating sphere. The sphere's output provides a uniform illumination over the entire focal plane. Nine references of LEDs from different manufacturers were selected, screened and qualified under cryogenic conditions. Testing this large quantity of samples led to the implementation of automated testing equipment with complete in-situ monitoring of optoelectronic parameters as well as temperature and vacuum values. All the electrical and optical parameters of the LED have been monitored and recorded at ambient and cryogenic temperatures. These results have been compiled in order to show the total deviation of the LED electrical and electro-optical properties in the whole mission and to select the best suitable LED references for the mission. This qualification has demonstrated the robustness of COTS LEDs to operate at low cryogenic temperatures and in the space environment. Then 6 wavelengths were selected and submitted to an EMC sensitivity test at room and cold temperature by counting the number of photons when LEDs drivers are OFF. Characterizations were conducted in the full frequency spectrum in order to implement solutions at system level to suppress the emission of photons when the LED drivers are OFF. LEDs impedance was also characterized at room temperature and cold temperature.

  18. Measurement of the photometric characteristics of LEDs

    International Nuclear Information System (INIS)

    Nazarenko, L.A.; Zubkov, D.P.

    2015-01-01

    Proposed and implemented a method for measuring LEDs, which is based on self-calibration of the LED goniophotometer facility by using a trap-detector. Designed and manufactured automated goniophotometer, which provides a measurement of high power LEDs at a specified junction temperature. Designed and experimentally researched the photometer with a photometric sphere based diffuser, which meets all requirements of CIE for photometric measurements of LEDs

  19. 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.

  20. 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

  1. Innovations in LED lighting for reduced-ESM crop production in space

    Science.gov (United States)

    Massa, Gioia; Mitchell, Cary; Bourget, C. Michael; Morrow, Robert

    In controlled-environment crop production such as will be practiced at the lunar outpost and Mars base, the single most energy-demanding aspect is electric lighting for plant growth, including energy costs for energizing lamps as well as for removing excess heat. For a variety of reasons, sunlight may not be a viable option as the main source of crop lighting off-Earth and traditional electric lamps for crop lighting have numerous drawbacks for use in a space environment. A collaborative research venture between the Advanced Life Support Crops Group at Purdue University and the Orbital Technologies Corporation (ORBITEC) has led to the development of efficient, reconfigurable LED lighting technologies for crop growth in an ALSS. The light sources use printed-circuit red and blue LEDs, which are individually tunable for a range of photosynthetic photon fluxes and photomorphogenic plant responses. Initial lighting arrays have LEDs that can be energized from the bottom upward when deployed in a vertical, intracanopy configuration, allowing the illumination to be tailored for stand height throughout the cropping cycle. Preliminary testing with the planophile crop cowpea (Vigna unguiculata L. Walp, breeding line IT87D-941-1), resulted in optimizing internal reflectance of growth compartments by lining walls, floor, and a movable ceiling with white Poly film, as well as by determining optimal planting density and plant positioning. Additionally, these light strips, called "lightsicles", can be configured into an overhead plane of light engines. When intracanopy and overhead-LED-lit cowpea crop production was compared, cowpea plants grown with intracanopy lighting had much greater understory leaf retention and produced more dry biomass per kilowatt-hour of lighting energy than did overhead-lit plants. The efficiency of light capture is reduced in overhead-lit scenarios due to mutual shading of lower leaves by upper leaves in closed canopies leading to premature abscission

  2. Prediction of L70 lumen maintenance and chromaticity for LEDs using extended Kalman filter models

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Wei, Junchao; Davis, Lynn

    2013-09-30

    Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. The measured state variable has been related to the underlying damage using physics-based models. Life

  3. 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...

  4. Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

    Science.gov (United States)

    Kong, H. J.; Park, J. W.; Kim, Y. M.

    2013-01-01

    We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m-2, the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system.

  5. Integration of organic LEDs with inorganic LEDs for a hybrid lighting system

    International Nuclear Information System (INIS)

    Kong, H J; Kim, Y M; Park, J W

    2013-01-01

    We demonstrate that a surface-emitting hybrid light source can be realized by a combination of organic and inorganic light-emitting devices (LEDs). To this end, a blue inorganic LED bar is deployed at one side of a transparent light guide plate (LGP), and a yellow organic LED (OLED) is in contact with the rear surface of the LGP. In such a configuration, it is found that the overall luminance is almost equivalent to the sum of the luminances measured from each light source, and the overall luminance uniformity is determined mainly by the luminance uniformity of the OLED panel at high luminances. We have achieved a white color showing the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (x = 0.34, y = 0.33), the power efficiency of 9.3 lm/W, the luminance uniformity of 63% at the luminance of 3100 cd m –2 , the color rendering index as high as 89.3, and the correlated color temperature finely tunable within the range between 3000 and 8000 K. Such a system facilitates color tuning by adjusting their luminous intensities and hence the implementation of the emotional lighting system. (paper)

  6. 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

  7. Rural Indonesia women’s traditional beliefs about antenatal care

    Directory of Open Access Journals (Sweden)

    Agus Yenita

    2012-10-01

    traditional beliefs led to a healthy pregnancy therefore, they also followed all relatives’ suggestions. Understanding the complexities of local culture is the first step to improving women’s awareness of how to preserve their pregnancy and prevent complications.

  8. Consumer-driven definition of traditional food products and innovation in traditional foods. A qualitative cross-cultural study.

    Science.gov (United States)

    Guerrero, Luis; Guàrdia, Maria Dolors; Xicola, Joan; Verbeke, Wim; Vanhonacker, Filiep; Zakowska-Biemans, Sylwia; Sajdakowska, Marta; Sulmont-Rossé, Claire; Issanchou, Sylvie; Contel, Michele; Scalvedi, M Luisa; Granli, Britt Signe; Hersleth, Margrethe

    2009-04-01

    Traditional food products (TFP) are an important part of European culture, identity, and heritage. In order to maintain and expand the market share of TFP, further improvement in safety, health, or convenience is needed by means of different innovations. The aim of this study was to obtain a consumer-driven definition for the concept of TFP and innovation and to compare these across six European countries (Belgium, France, Italy, Norway, Poland and Spain) by means of semantic and textual statistical analyses. Twelve focus groups were performed, two per country, under similar conditions. The transcriptions obtained were submitted to an ordinary semantic analysis and to a textual statistical analysis using the software ALCESTE. Four main dimensions were identified for the concept of TFP: habit-natural, origin-locality, processing-elaboration and sensory properties. Five dimensions emerged around the concept of innovation: novelty-change, variety, processing-technology, origin-ethnicity and convenience. TFP were similarly perceived in the countries analysed, while some differences were detected for the concept of innovation. Semantic and statistical analyses of the focus groups led to similar results for both concepts. In some cases and according to the consumers' point of view the application of innovations may damage the traditional character of TFP.

  9. 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.

  10. 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.

  11. An LED Approach for Measuring the Photocatalytic Breakdown of Crystal Violet Dye

    Science.gov (United States)

    Ryan, Robert E.; Underwood, Lauren W.; ONeal, Duane; Pagnutti, Mary; Davis, Bruce A.

    2009-01-01

    dye degradation on the slides over time, a temperature-stabilized white light LED was used to illuminate the opposite side of the slides. As the dye degraded, the amount of light from the white light LED transmitted through the slide was monitored with a spectrometer and subsequently analyzed to determine and compare the rate of dye degradation for photocatalytically coated versus uncoated slide surfaces. The long-term stability of the spectrometer/white light LED combination, which required only a single reference spectra to be taken for a time series sequence of several hours, enabled accurate measurements of transmitted light over time. Time series transmission curves were generated and results demonstrated that over time the transmission increased much more rapidly on the coated slides than on the control slides. This experimental configuration and methodology for photocatalytic activity measurement minimizes many external variable effects and allows low light level studies to be performed. This study also compares the advantages of this novel LED light source design to traditional mercury lamp systems and non-LED lamp approaches that have conventionally been used. The methodology and experimental design research summarized in this abstract is partly funded by the Department of Homeland Security, Science and Technology Directorate, and by the NASA Stennis Space Center Innovative Partnerships Program.

  12. Traditional justice in the reconciliation between Rwanda and Burundi

    Directory of Open Access Journals (Sweden)

    Antoni Castel

    2009-10-01

    Full Text Available This article reviews the use of traditional justice in two post-conflicts in the Great Lakes region: those of Rwanda and Burundi. In Rwanda, the government, led by the Rwanda Patriotic Front (FPR, has modernised and shaped for its own interests the gacaca, who are responsible for seeking justice for the victims of the 1994 genocide. In Burundi, the government has yet not deployed all the transitional justice mechanisms as envisaged in the Arusha agreement. The bushingantahe (the rehabilitation of whom is also envisaged in the agreement have not yet been incorporated into transitional justice.

  13. 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...

  14. Traditional oral health beliefs and practices of Bulang people in Yunnan, China.

    Science.gov (United States)

    Zhang, Shinan; Lo, Edward C M; Chu, Chun-Hung

    2018-02-01

    The aim of the present study was to explore traditional oral health beliefs among the Bulang ethnic minority group in China. Eighteen village leaders, chiefs, elders, and seniors in Yunnan, China were assigned to three focus groups for discussion of traditional oral health beliefs. The discussions were led by a facilitator. Transcripts were made, and data were extracted. The focus group discussions on traditional oral health beliefs addressed three themes: (a) the perception of oral health; (b) the impact of healthy teeth (oral health), in that healthy teeth essentially have an impact on physical health, emotions, and social status; and (c) toothache management, which was regarded as tooth decay (dental caries). Blackening teeth was a pain relief method. Blackened teeth were reported to be part of ethnic identity, and considered esthetically pleasing. It also indicated the marital status of women. Some Bulang people believed that healthy dentition has no spacing, pain, or functioning problems. Well-aligned dentition was associated with higher social status. Toothaches were considered to be caused by tooth worms. Consulting a monk was another way to manage a toothache. Tooth blackening was considered traditional, and effective for caries prevention. © 2017 John Wiley & Sons Australia, Ltd.

  15. 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....

  16. Long-lived visible luminescence of UV LEDs and impact on LED excited time-resolved fluorescence applications

    International Nuclear Information System (INIS)

    Jin, D; Connally, R; Piper, J

    2006-01-01

    We report the results of a detailed study of the spectral and temporal properties of visible emission from three different GaN-based ultraviolet (UV) light emitting diodes (UV LEDs). The primary UV emission in the 360-380 nm band decays rapidly (less than 1 μs) following switch-off; however, visible luminescence (470-750 nm) with a decay lifetime of tens of microseconds was observed at approximately 10 -4 of the UV intensity. For applications of UV LEDs in time-resolved fluorescence (TRF) employing lanthanide chelates, the visible luminescence from the LEDs competes with the target Eu 3+ or Tb 3+ fluorescence in both spectral and temporal domains. A UV band-pass filter (Schott UG11 glass) was therefore used to reduce the visible luminescence of the UV LEDs by three orders of magnitude relative to UV output to yield a practical excitation source for TRF

  17. Optical characterization of ultrabright LEDs

    International Nuclear Information System (INIS)

    Benavides, Juan Manuel; Webb, Robert H.

    2005-01-01

    Ultrabright light emitting diodes (LEDs) are a new light source for visual psychophysics and microscopy. The new LEDs are intended primarily for room and exterior illumination, and the manufacturers' specifications are adequate for that. However, we use them as light sources in situations where a more complete characterization may be useful. For one set of LEDs we have measured the radiometric intensity and its distribution in space and wavelength, and we have tested for interactions of these variables and their dependence on driver configuration. We describe techniques for making these measurements and give a link to a simple calculator for converting among radiometric and photometric measures, as well as an evaluation of the safety considerations these very bright sources demand

  18. White LED visible light communication technology research

    Science.gov (United States)

    Yang, Chao

    2017-03-01

    Visible light communication is a new type of wireless optical communication technology. White LED to the success of development, the LED lighting technology is facing a new revolution. Because the LED has high sensitivity, modulation, the advantages of good performance, large transmission power, can make it in light transmission light signal at the same time. Use white LED light-emitting characteristics, on the modulation signals to the visible light transmission, can constitute a LED visible light communication system. We built a small visible optical communication system. The system composition and structure has certain value in the field of practical application, and we also research the key technology of transmitters and receivers, the key problem has been resolved. By studying on the optical and LED the characteristics of a high speed modulation driving circuit and a high sensitive receiving circuit was designed. And information transmission through the single chip microcomputer test, a preliminary verification has realized the data transmission function.

  19. Lipid oxidative changes in traditional dry fermented sausage Petrovská klobása during storage

    Directory of Open Access Journals (Sweden)

    Šojić Branislav V.

    2014-01-01

    Full Text Available The influence of drying and ripeninig conditions (traditional and industrial in the production of dry fermented sausage Petrovská klobása, on fatty-acid composition and oxidative changes in lipids, during 7 months of storage, was investigated. During the storage period, the sum of unsaturated fatty acids and the content of free fatty acids were significantly higher (p<0.05, while the content of malondialdehyde was significantly lower in the sausage subjected to traditional conditions of drying and ripening. At the end of the storage period, contents of pentanal and hexanal in the sausage subjected to traditional conditions of drying and ripening (4.03 μg/g and 1.67 μg/g, respectively were significantly lower (p<0.05 in comparison with these contents in the sausage subjected to industrial conditions of drying and ripening. Traditional conditions of drying and ripening at lower temperatures have led to lower oxidative changes in lipids in traditional dry fermented sausage Petrovská klobása during storage period. [Projekat Ministarstva nauke Republike Srbije, br. TR31032

  20. Development of high-performance solar LED lighting system

    KAUST Repository

    Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

    2010-01-01

    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.

  1. Development of high-performance solar LED lighting system

    International Nuclear Information System (INIS)

    Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

    2010-01-01

    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.

  2. 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.

  3. Evaluating UV-C LED disinfection performance and ...

    Science.gov (United States)

    This study evaluated ultraviolet (UV) light emitting diodes (LEDs) emitting at 260 nm, 280 nm, and the combination of 260|280 nm together for their efficacy at inactivating Escherichia. coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores; research included an evaluation of genomic damage. Inactivation by the LEDs was compared with the efficacy of conventional UV sources, the low-pressure (LP) and medium-pressure (MP) mercury vapor lamps. The work also calculated the electrical energy per order of reduction of the microorganisms by the five UV sources.For E. coli, all five UV sources yielded similar inactivation rates. For MS2 coliphage, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was significantly more effective than the LP UV and UVC LED sources. When considering electrical energy per order of reduction, the LP UV lamp was the most efficient for E. coli and MS2, and the MPUV and LPUV were equally efficient for HAdV2 and B. pumilus spores. Among the UVC LEDs, the 280 nm LED unit required the least energy per log reduction of E. coli and HAdV2. The 280 nm and 260|280 nm LED units were equally efficient per log reduction of B. pumilus spores, and the 260 nm LED unit required the lowest energy per order of reduction of MS2 coliphage. The combination of the 260 nm and 280 nm UV LED wavelengths was also evaluated for potential synergistic effects. No dual-wavelength synergy was detected for inactivation of

  4. ZnO-nanorods: A possible white LED phosphor

    Science.gov (United States)

    Sarangi, Sachindra Nath; T., Arun; Ray, Dinseh K.; Sahoo, Pratap Kumar; Nozaki, Shinji; Sugiyama, Noriyuki; Uchida, Kazuo

    2017-05-01

    The white light-emitting diodes (LEDs) have drawn much attention to replace conventional lighting sources because of low energy consumption, high light efficiency and long lifetime. Although the most common approach to produce white light is to combine a blue LED chip and a yellow phosphor, such a white LED cannot be used for a general lighting application, which requires a broad luminescence spectrum in the visible wavelength range. We have successfully chemically synthesized the ZnO nanorods showing intense broad luminescence in the visible wavelength range and made a white LED using the ZnO nanorods as phosphor excited with a blue LED. Their lengths and diameters were 2 - 10 μm and 200 - 800 nm, respectively. The wurtzite structure was confirmed by the x-ray diffraction measurement. The PL spectrum obtained by exciting the ZnO nanorods with the He-Cd laser has two peaks, one associated with the near band-edge recombination and the other with recombination via defects. The peak intensity of the near band-edge luminescence at 388 nm is much weaker than that of the defect-related luminescence. The latter luminescence peak ranges from 450 to 850 nm and broad enough to be used as a phosphor for a white LED. A white LED has been fabricated using a blue LED with 450 nm emission and ZnO nanorod powders. The LED performances show a white light emission and the electroluminescence measurement shows a stiff increase in white light intensity with increasing blue LED current. The Commission International de1'Eclairage (CIE) chromaticity colour coordinates of 450 nm LED pumped white emission shows a coordinate of (0.31, 0.32) for white LED at 350 mA. These results indicate that ZnO nanorods provides an alternate and effective approach to achieve high-performance white LEDs and also other optoelectronic devices.

  5. 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...

  6. 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.

  7. The Canarian Camel: A Traditional Dromedary Population

    Directory of Open Access Journals (Sweden)

    Ursula Schulz

    2010-04-01

    Full Text Available The domestic camel (dromedary is the most important livestock species in the Canary Islands and the most important autochthonous European camel population. After six centuries of a successful adaptation process to the particular environment of the Canary Islands, the abandonment of traditional agriculture has led this population to a major bottleneck. Along with a lack of foreign genetic interchanges, this could lead the population to the brink of extinction. Genetic analysis using 13 microsatellites showed the closest genetic proximity to the North African (Tindouf, Algeria camel population and a certain degree of sub-division, with significant genetic differences among breeders. An important level of genetic differentiation among the different populations analyzed was found with a global FST value of 0.116.

  8. Comparison of INTAKE24 (an Online 24-h Dietary Recall Tool) with Interviewer-Led 24-h Recall in 11-24 Year-Old.

    Science.gov (United States)

    Bradley, Jennifer; Simpson, Emma; Poliakov, Ivan; Matthews, John N S; Olivier, Patrick; Adamson, Ashley J; Foster, Emma

    2016-06-09

    Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11-24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method) with interviewer-led multiple pass 24-h recalls (the comparison method) in 180 people aged 11-24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars) were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults.

  9. UV-LED Curing Efficiency of Wood Coatings

    OpenAIRE

    Véronic Landry; Pierre Blanchet; Gabrielle Boivin; Jean-François Bouffard; Mirela Vlad

    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 powerf...

  10. Forms of Pilgrimage at the Shrine of Khāled Nabi, Northeastern Iran

    Directory of Open Access Journals (Sweden)

    Mehdi Ebadi

    2015-07-01

    Full Text Available Pilgrimage (religious tourism is one of the fastest growing forms of tourism. Nevertheless, there is still a gap between abstract theory and empirical research about this form of tourism in the literature. This dearth of tourism studies is even more glaring in the field of Ziyārat or pilgrimage in Islam which in spite of its importance and wide extended practice have been mostly ignored in tourism and geographic literature. The present study features one such area that is (almost unknown within the community of tourism and geography researchers. In Iran, religious pilgrimage has a long tradition. Numerous sacred places with varieties of rituals and traditions, which practice among the pilgrims all around the country, indicate on its antiquity (before Islamic periods. Among the most practiced forms of religious pilgrimage are the visits to several thousands of shrines, which are known in Iran as Ziyāratgah (lit. place of visit or Imāmzādeh. One of these Ziyāratgah is the pre-Islamic shrine of Khāled Nabi (also known as Halat Nabi, which belong to a legendary Christian holy man of the 6th A.D. The shrine lies in the northeastern Iranian province of Golestan, in a region called Turkmen-Sahra. Despite its relative remote setting, every year more than 90,000 travellers do visit this shrine. This article seeks to consider varieties of pilgrimage forms at the shrine. The results of the study shows that the travelers of Khāled Nabi shrine are not homogenous and comprise of different types of visitors. In addition to secular motivations, based on the visitors’ inventives, three zones/forms of pilgrimage, namely, ‘‘religious pilgrims’’, ‘‘cultural pilgrims’’, ‘‘nostalgic pilgrims’’have been recognized.

  11. 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

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

    KAUST Repository

    Janjua, Bilal

    2016-08-10

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

  13. Using Web-Based Interactive Multimedia to Supplement Traditional Teaching Methods: A Pilot Program for Medical Training of Non-Medical Personnel

    National Research Council Canada - National Science Library

    Gellman, Gregg W

    2005-01-01

    This thesis proposes that it is possible to create an adjunct to traditional instructor-led training that will reduce training time and costs and at the same time improve performance using commercial off-the shelf (COTS) software...

  14. Advanced Cardiac Resuscitation Evaluation (ACRE: A randomised single-blind controlled trial of peer-led vs. expert-led advanced resuscitation training

    Directory of Open Access Journals (Sweden)

    Hughes Thomas C

    2010-01-01

    Full Text Available Abstract Background Advanced resuscitation skills training is an important and enjoyable part of medical training, but requires small group instruction to ensure active participation of all students. Increases in student numbers have made this increasingly difficult to achieve. Methods A single-blind randomised controlled trial of peer-led vs. expert-led resuscitation training was performed using a group of sixth-year medical students as peer instructors. The expert instructors were a senior and a middle grade doctor, and a nurse who is an Advanced Life Support (ALS Instructor. A power calculation showed that the trial would have a greater than 90% chance of rejecting the null hypothesis (that expert-led groups performed 20% better than peer-led groups if that were the true situation. Secondary outcome measures were the proportion of High Pass grades in each groups and safety incidents. The peer instructors designed and delivered their own course material. To ensure safety, the peer-led groups used modified defibrillators that could deliver only low-energy shocks. Blinded assessment was conducted using an Objective Structured Clinical Examination (OSCE. The checklist items were based on International Liaison Committee on Resuscitation (ILCOR guidelines using Ebel standard-setting methods that emphasised patient and staff safety and clinical effectiveness. The results were analysed using Exact methods, chi-squared and t-test. Results A total of 132 students were randomised: 58 into the expert-led group, 74 into the peer-led group. 57/58 (98% of students from the expert-led group achieved a Pass compared to 72/74 (97% from the peer-led group: Exact statistics confirmed that it was very unlikely (p = 0.0001 that the expert-led group was 20% better than the peer-led group. There were no safety incidents, and High Pass grades were achieved by 64 (49% of students: 33/58 (57% from the expert-led group, 31/74 (42% from the peer-led group. Exact

  15. 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)

  16. Reaching Urban Poor Hypertensive Patients: A Novel Model of Chronic Disease Care Versus a Traditional Fee-for-Service Approach.

    Science.gov (United States)

    Sanders, Jim; Guse, Clare E

    2016-08-09

    There is a significant disparity in hypertensive treatment rates between those with and without health insurance. If left untreated, hypertension leads to significant morbidity and mortality. The uninsured face numerous barriers to access chronic disease care. We developed the Community-based Chronic Disease Management (CCDM) clinics specifically for the uninsured with hypertension utilizing nurse-led teams, community-based locations, and evidence-based clinical protocols. All services, including laboratory and medications, are provided on-site and free of charge. In order to ascertain if the CCDM model of care was as effective as traditional models of care in achieving blood pressure goals, we compared CCDM clinics' hypertensive care outcomes with 2 traditional fee-for-service physician-led clinics. All the clinics are located near one another in poor urban neighborhoods of Milwaukee, Wisconsin. Patients seen at the CCDM clinics and at 1 of the 2 traditional clinics showed a statistically significant improvement in reaching blood pressure goal at 6 months (P fee-for-service clinics when compared with the CCDM clinics. The CCDM model of care is at least as effective in controlling hypertension as more traditional fee-for-service models caring for the same population. The CCDM model of care to treat hypertension may offer another approach for engaging the urban poor in chronic disease care. © The Author(s) 2016.

  17. 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.

  18. High Efficiency Driving Electronics for General Illumination LED Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    Upadhyay, Anand

    2012-10-31

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

  19. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

  20. Comparison of INTAKE24 (an Online 24-h Dietary Recall Tool with Interviewer-Led 24-h Recall in 11–24 Year-Old

    Directory of Open Access Journals (Sweden)

    Jennifer Bradley

    2016-06-01

    Full Text Available Online dietary assessment tools offer a convenient, low cost alternative to traditional dietary assessment methods such as weighed records and face-to-face interviewer-led 24-h recalls. INTAKE24 is an online multiple pass 24-h recall tool developed for use with 11–24 year-old. The aim of the study was to undertake a comparison of INTAKE24 (the test method with interviewer-led multiple pass 24-h recalls (the comparison method in 180 people aged 11–24 years. Each participant completed both an INTAKE24 24-h recall and an interviewer-led 24-h recall on the same day on four occasions over a one-month period. The daily energy and nutrient intakes reported in INTAKE24 were compared to those reported in the interviewer-led recall. Mean intakes reported using INTAKE24 were similar to the intakes reported in the interviewer-led recall for energy and macronutrients. INTAKE24 was found to underestimate energy intake by 1% on average compared to the interviewer-led recall with the limits of agreement ranging from minus 49% to plus 93%. Mean intakes of all macronutrients and micronutrients (except non-milk extrinsic sugars were within 4% of the interviewer-led recall. Dietary assessment that utilises technology may offer a viable alternative and be more engaging than paper based methods, particularly for children and young adults.

  1. Interconnectedness between shadow and traditional banking systems in Europe

    Directory of Open Access Journals (Sweden)

    Popović Svetlana

    2017-01-01

    Full Text Available The financial crisis that emerged in the US quickly spread across Europe, causing a severe banking and sovereign debt crisis. That revealed the importance of short-term financing for traditional banks, which increased their exposure to the financial conditions on the interbank market. Financial innovations, especially the securitization process led to the growing importance of different institutions within the shadow banking system - which undergo a credit, liquidity and maturity transformation, without accessing the central bank liquidity or other forms of guarantees. The European banks had an active role in the US securitization process, but also securitized the products from the European market. The authors used the available data from the ECB statistics on shadow bank entities, broadly and narrowly defined, in order to analyze the various measures of interconnectedness between the shadow and traditional banking systems. The analysis showed that non-regulated financial institutions pose severe systemic risks, not just because of their size, but also due to the strong web of interconnectedness with the regulated banking sector.

  2. Prediction of Lumen Output and Chromaticity Shift in LEDs Using Kalman Filter and Extended Kalman Filter Based Models

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Wei, Junchao; Davis, J Lynn

    2014-06-24

    Abstract— Solid-state lighting (SSL) luminaires containing light emitting diodes (LEDs) have the potential of seeing excessive temperatures when being transported across country or being stored in non-climate controlled warehouses. They are also being used in outdoor applications in desert environments that see little or no humidity but will experience extremely high temperatures during the day. This makes it important to increase our understanding of what effects high temperature exposure for a prolonged period of time will have on the usability and survivability of these devices. Traditional light sources “burn out” at end-of-life. For an incandescent bulb, the lamp life is defined by B50 life. However, the LEDs have no filament to “burn”. The LEDs continually degrade and the light output decreases eventually below useful levels causing failure. Presently, the TM-21 test standard is used to predict the L70 life of LEDs from LM-80 test data. Several failure mechanisms may be active in a LED at a single time causing lumen depreciation. The underlying TM-21 Model may not capture the failure physics in presence of multiple failure mechanisms. Correlation of lumen maintenance with underlying physics of degradation at system-level is needed. In this paper, Kalman Filter (KF) and Extended Kalman Filters (EKF) have been used to develop a 70-percent Lumen Maintenance Life Prediction Model for LEDs used in SSL luminaires. Ten-thousand hour LM-80 test data for various LEDs have been used for model development. System state at each future time has been computed based on the state space at preceding time step, system dynamics matrix, control vector, control matrix, measurement matrix, measured vector, process noise and measurement noise. The future state of the lumen depreciation has been estimated based on a second order Kalman Filter model and a Bayesian Framework. Life prediction of L70 life for the LEDs used in SSL luminaires from KF and EKF based models have

  3. Screening for Anti-lipase Properties of 37 Traditional Chinese Medicinal Herbs

    Directory of Open Access Journals (Sweden)

    Cheng-Dong Zheng

    2010-06-01

    Conclusion: The results support the view that herbs represent a rich source of anti-lipase compounds. The screening of the methanolic extracts of 37 Chinese medicinal plants in vitro led to the identification of several extracts with potential activity against PPL, in particular, P. vulgaris and R. palmatum. We also found that several monomeric chemicals in these herbs exhibited good or moderate activity against PPL. To the best of our knowledge, these traditional Chinese herbal medicines or phytochemicals have not been previously screened for their lipase inhibitory activity.

  4. Financial products as alternatives to traditional deposits

    Directory of Open Access Journals (Sweden)

    Cristina Lidia MANEA

    2016-05-01

    In this context, increasing the safety of depositors appears as an undisputed necessity, which translates to our approach in the development of a constructive type applied research that takes into account the following stages: short description of risks and uncertainties characterizing the economic environment with emphasis on the importance of the financial instruments; analysis of empirical data on deposits in lei and euro at national level, identifying possible causes which led to one preference or another and finding the causes underlying the different options manifested in the capital, as compared to other counties; identifying the products that offer a dangerous alternative to traditional deposits from the Romanian banking market and describing these products and their related risks; the proposal of a new product, demonstrating its effectiveness by testing and confirmation of two hypotheses.

  5. LED-pumped Alexandrite laser oscillator and amplifier

    Science.gov (United States)

    Pichon, Pierre; Blanchot, Jean-Philippe; Balembois, François; Druon, Frédéric; Georges, Patrick

    2018-02-01

    In this paper, we report the first LED-pumped transition-metal-doped laser oscillator and amplifier based on an alexandrite crystal (Cr3+:BeAl2O4). A Ce:YAG luminescent concentrator illuminated by blue LEDs is used to reach higher pump powers than with LEDs alone. The luminescent 200-mm-long-composit luminescent concentrator involving 2240 LEDs can delivers up to 268 mJ for a peak irradiance of 8.5 kW/cm2. In oscillator configuration, an LED-pumped alexandrite laser delivering an energy of 2.9 mJ at 748 nm in free running operation is demonstrated. In the cavity, we measured a double pass small signal gain of 1.28, in good agreement with numerical simulations. As amplifier, the system demonstrated to boost a CW Ti:sapphire laser by a factor of 4 at 750 nm in 8 passes with a large tuning range from 710 nm to 800 nm.

  6. Patient-led versus physician-led titration of insulin glargine in patients with uncontrolled type 2 diabetes: a randomized multinational ATLAS study.

    Science.gov (United States)

    Garg, Satish K; Admane, Karim; Freemantle, Nick; Odawara, Masato; Pan, Chang-Yu; Misra, Anoop; Jarek-Martynowa, Iwona R; Abbas-Raza, Syed; Mirasol, Roberto C; Perfetti, Riccardo

    2015-02-01

    Self-adjustment of insulin dose is commonly practiced in Western patients with type 2 diabetes but is usually not performed in Asian patients. This multinational, 24-week, randomized study compared patient-led with physician-led titration of once-daily insulin glargine in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering agents. Patient-led (n = 275) or physician-led (n = 277) subjects followed the same dose-titration algorithm guided by self-monitored fasting blood glucose (FBG; target, 110 mg/dL [6.1 mmol/L]). The primary endpoint was change in mean glycated hemoglobin (HbA1c) at week 24 in the patient-led versus physician-led titration groups. Patient-led titration resulted in a significantly higher drop in HbA1c value at 24 weeks when compared with physician-led titration (-1.40% vs. -1.25%; mean difference, -0.15; 95% confidence interval, -0.29 to 0.00; P = .043). Mean decrease in FBG was greatest in the patient-led group (-2.85 mmol/L vs. -2.48 mmol/L; P = .001). The improvements in HbA1c and FBG were consistent across countries, with similar improvements in treatment satisfaction in both groups. Mean daily insulin dose was higher in the patient-led group (28.9 units vs. 22.2 units; Ptitration achieved near-target blood glucose levels in Asian patients with uncontrolled type 2 diabetes who were on 2 oral glucose-lowering drugs, demonstrating that Asian patients can self-uptitrate insulin dose effectively when guided.

  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. 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.

  10. 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)

  11. An overview of LED applications for general illumination

    Science.gov (United States)

    Pelka, David G.; Patel, Kavita

    2003-11-01

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

  12. High-power LEDs for plant cultivation

    Science.gov (United States)

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

    2004-10-01

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

  13. Semiconductor lasers and herterojunction leds

    CERN Document Server

    Kressel, Henry

    2012-01-01

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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  15. 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.

  16. A method of LED free-form tilted lens rapid modeling based on scheme language

    Science.gov (United States)

    Dai, Yidan

    2017-10-01

    According to nonimaging optical principle and traditional LED free-form surface lens, a new kind of LED free-form tilted lens was designed. And a method of rapid modeling based on Scheme language was proposed. The mesh division method was applied to obtain the corresponding surface configuration according to the character of the light source and the desired energy distribution on the illumination plane. Then 3D modeling software and the Scheme language programming are used to generate lens model respectively. With the help of optical simulation software, a light source with the size of 1mm*1mm*1mm in volume is used in experiment, and the lateral migration distance of illumination area is 0.5m, in which total one million rays are computed. We could acquire the simulated results of both models. The simulated output result shows that the Scheme language can prevent the model deformation problems caused by the process of the model transfer, and the degree of illumination uniformity is reached to 82%, and the offset angle is 26°. Also, the efficiency of modeling process is greatly increased by using Scheme language.

  17. 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

  18. 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

  19. UV-LED Curing Efficiency of Wood Coatings

    Directory of Open Access Journals (Sweden)

    Véronic Landry

    2015-12-01

    Full Text Available 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 UV high solids acrylate coatings while satisfactory results can be obtained for UV water-based formulations. In fact, conversion percentages were found to be low for the high solids coatings, leaving the coatings tacky. Higher conversion percentages were obtained for the UV water-based formulations. As a result, mass loss, hardness, and scratch resistance found for the samples cured by UV-LED were closed to the ones found for the samples cured using the UV microwave lamp.

  20. 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

  1. 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.

  2. High power blue LED development using different growth modes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong S.; Florescu, Doru I.; Ramer, Jeff C.; Merai, Vinod; Parekh, Aniruddh; Begarney, Michael J.; Armour, Eric A. [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); Lu Dong [Veeco TurboDisc Operations, 394 Elizabeth Avenue, Somerset, NJ 08873 (United States); School of Engineering, Rutgers University, Piscataway, NJ 08854 (United States)

    2004-09-01

    Blue high brightness light emitting diodes (HB-LEDs) have been developed using different growth modes in the active layers. Piezoelectric field engineering improves the optical output power in multiple quantum well (MQW) LEDs by inserting an optimized transitional superlattice (TSL) before the active MQW layers. Within single quantum well (SQW) LEDs, quasi-Quantum Dot (QD) growth for Indium localization has been realized. The SQW LED output power exceeds the strain engineered MQW LEDs. The experimental data indicates that Indium localization enhances overall quantum efficiency and results in increased output power for HB-LEDs. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Comparative Study of Lettuce and Radish Grown Under Red and Blue LEDs and White Fluorescent Lamps

    Science.gov (United States)

    Mickens, Matthew A.; Massa, Gioia; Newsham, Gerard; Wheeler, Raymond; Birmele, Michele

    2016-01-01

    Growing vegetable crops in space will be an essential part of sustaining astronauts during long-range missions. To drive photosynthesis, red and blue light-emitting diodes (LEDs) have attracted attention because of their efficiency, longevity, small size, and safety. In efforts to optimize crop yield, there is also recent interest in analyzing the subtle effects of additional wavelengths on plant growth. For instance, since plants often look purplish gray under red and blue LEDs, the addition of green light allows easy recognition of disease and the assessment of plant health status. However, it is important to know if wavelengths outside the traditional red and blue wavebands have a direct effect on enhancing or hindering the mechanisms involved in plant growth. In this experiment, a comparative study was performed on two short cycle crops of red romaine lettuce (Lactuca sativa cv. "Outredgeous") and radish (Raphanus sativa cv. 'Cherry Bomb'), which were grown under two light treatments. The first treatment being red (630 nm) and blue (450 nm) LEDs alone, while the second treatment consisted of daylight tri-phosphor fluorescent lamps (CCT approximately 5000 K) at equal photosynthetic photon flux (PPF). The treatment effects were evaluated by measuring the fresh biomass produced, plant morphology and leaf dimensions, leaf chlorophyll content, and adenosine triphosphate (ATP) within plant leaf/storage root tissues.

  4. Preliminary investigations of piezoelectric based LED luminary

    DEFF Research Database (Denmark)

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

    2011-01-01

    , modulation schemes, LEDs and LED driving conditions are analyzed. A prototype radial mode PT optimized for ZVS (Zero Voltage Switching) is designed. FEM (Final Element Method) and measurements validates the PT design. A prototype PT based AC/DC converter operating from european mains is proposed......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...

  5. Analysis of Student Performance in Peer Led Undergraduate Supplements

    Science.gov (United States)

    Gardner, Linda M.

    Foundations of Chemistry courses at the University of Kansas have traditionally accommodated nearly 1,000 individual students every year with a single course in a large lecture hall. To develop a more student-centered learning atmosphere, Peer Led Undergraduate Supplements (PLUS) were introduced to assist students, starting in the spring of 2010. PLUS was derived from the more well-known Peer-Led Team Learning with modifications to meet the specific needs of the university and the students. The yearlong investigation of PLUS Chemistry began in the fall of 2012 to allow for adequate development of materials and training of peer leaders. We examined the impact of academic achievement for students who attended PLUS sessions while controlling for high school GPA, math ACT scores, credit hours earned in high school, completion of calculus, gender, and those aspiring to be pharmacists (i.e., pre-pharmacy students). In a least linear squares multiple regression, PLUS participants performed on average one percent higher on exam scores for Chemistry 184 and four tenths of a percent on Chemistry 188 for each PLUS session attended. Pre-pharmacy students moderated the effect of PLUS attendance on chemistry achievement, ultimately negating any relative gain associated by attending PLUS sessions. Evidence of gender difference was demonstrated in the Chemistry 188 model, indicating females experience a greater benefit from PLUS sessions. Additionally, an item analysis studied the relationship between PLUS material to individual items on exams. The research discovered that students who attended PLUS session, answered the items correctly 10 to 20 percent more than their comparison group for PLUS interrelated items and no difference to 10 percent for non-PLUS related items. In summary, PLUS has a positive effect on exam performance in introductory chemistry courses at the University of Kansas.

  6. Refrigerating liquid prototype for LED's thermal management

    International Nuclear Information System (INIS)

    Faranda, Roberto; Guzzetti, Stefania; Lazaroiu, George Cristian; Leva, Sonia

    2012-01-01

    The heat management is the critical factor for high performance operation of LED. A new heat management application of refrigerating liquid integrated within a fabricated prototype is proposed and investigated. A series of experiments considering different heights of liquid level were performed to evaluate the heat dissipation performance and optical characteristics of the refrigerating liquid based prototype. The results reveal that the junction temperature decreases as the level of refrigerating liquid increases. The experimental results report that the refrigerating liquid reduces the junction temperature, and can positively influence the luminous radiation performances. An optimization investigation of the proposed solution was carried out to find an optimum thermal performance. The experiments indicated that refrigerating liquid cooling is a powerful way for heat dissipation of high power LEDs, and the fabrication of prototype was feasible and useful. - Highlights: ► New heat management application of refrigerating liquid on a fabricated LED prototype. ► Thermal models setup and comparison between the classical and the new solutions. ► The impact of refrigerating liquid level on LED thermal and luminous performances. ► The relationship between different levels of liquid with LED prototype performances.

  7. 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

  8. Community-Led Assessment of Risk from Exposure to Mercury by Native Amerindian Wayana in Southeast Suriname

    International Nuclear Information System (INIS)

    Peplow, D.; Augustine, S.; Peplow, D.

    2012-01-01

    This study was a collaboration between Western public health researchers and Suriname indigenous communities. The question asked was how can Western researchers effectively engage traditional indigenous communities in Suriname, South America, in public health research. The approach used a combination of Participatory Action Research methods in which Western researchers became participating observers in an indigenous-led research initiative. The Wayana communities of Puleowime (Apetina) and Kawemhakan (Anapayke) defined a single objective: determine for themselves whether they are at risk from exposure to mercury (Hg) contamination. Community members collected hair samples for analysis. Hair samples were analyzed using a portable Hg analyzer. Individual, community and hazard quotient indices were used to quantify risk. Results showed the Wayana were at a high lifetime risk of adverse effects from exposure to Hg. This study showed that the community-led approach is an effective way Westerners can engage indigenous communities and address serious public health threats. While factors that appealed to indigenous communities were identified, obstacles inherent to Western research methodology were also encountered

  9. Testing high brightness LEDs relative to application environment

    Science.gov (United States)

    Singer, Jeffrey; Mangum, Scott; Lundberg, John

    2006-08-01

    Application of light emitting diodes is expanding as the luminous output and efficiencies of these devices improve. At the same time, the number of LED package types is increasing, making it challenging to determine the appropriate device for use in lighting product designs. A range of factors should be considered when selecting a LED for an application including color coordinates, luminous efficacy, cost, lumen maintenance, application life, packaging and manufacturability. Additional complexities can be introduced as LED packages become obsolete and replacement parts must be selected. The replacement LED characteristics must be understood and assessed against the parameters of the original device, in order to determine if the change will be relatively simple or will force other end-product changes. While some characteristics are readily measured and compared, other factors, such as lumen maintenance, are difficult to verify. This paper will discuss the characteristics of a LED that should be considered during the design process as well as methods to validate these characteristics, particularly those which are not typically on data sheets or, are critical to the design and warrant additional validation. Particular attention will be given to LED lumen maintenance. While published manufacturer data typically provides temperature versus performance curves, the data may not be useful depending upon the application's operating environment. Models must be created to estimate the LED's junction temperature and degradation curve at the applied temperature in order to develop a more precise life estimate. This paper presents one approach to a LED device life and performance study designed with application environments in mind.

  10. Skeuomorphs’: on the rhetoric of material in the Gumelniţa tradition

    Directory of Open Access Journals (Sweden)

    Dragoş Gheorghiu

    2012-12-01

    Full Text Available The social changes, which characterise the Chalcolithic in southeastern Europe, which coincide with the emergence of metals, imposed a new material and led to the emergence of skeuomorphs (i.e. copies of objects made from a material different from that of the originals. Some gold objects from the Gumelnita tradition were objects of value, such as the valves of exotic shells, which therefore become visible in the form of paraphernalia. The present paper discusses the rhetoric of material visible in the shape and proximity of originals and skeuomorphs.

  11. Reception of the Istrian musical tradition(s

    Directory of Open Access Journals (Sweden)

    Marušić Dario

    2007-01-01

    Full Text Available The successive colonization of Istria with culturally differentiated populations, and peripheral position of the peninsula regarding both the Latin and Slav worlds, has conditioned interesting phenomena which defines the traditional life of the province. On the spiritual level it is primarily reflected in two cultural dimensions: the language and traditional music.

  12. Determination of LEDs degradation with entropy generation rate

    Science.gov (United States)

    Cuadras, Angel; Yao, Jiaqiang; Quilez, Marcos

    2017-10-01

    We propose a method to assess the degradation and aging of light emitting diodes (LEDs) based on irreversible entropy generation rate. We degraded several LEDs and monitored their entropy generation rate ( S ˙ ) in accelerated tests. We compared the thermoelectrical results with the optical light emission evolution during degradation. We find a good relationship between aging and S ˙ (t), because S ˙ is both related to device parameters and optical performance. We propose a threshold of S ˙ (t) as a reliable damage indicator of LED end-of-life that can avoid the need to perform optical measurements to assess optical aging. The method lays beyond the typical statistical laws for lifetime prediction provided by manufacturers. We tested different LED colors and electrical stresses to validate the electrical LED model and we analyzed the degradation mechanisms of the devices.

  13. A comparison of pediatric basic life support self-led and instructor-led training among nurses.

    Science.gov (United States)

    Vestergaard, Lone D; Løfgren, Bo; Jessen, Casper L; Petersen, Christina B; Wolff, Anne; Nielsen, Henrik V; Krarup, Niels H V

    2017-02-01

    Pediatric cardiac arrest carries a poor prognosis. Basic life support improves survival. Studies on pediatric basic life support (PBLS) training are sparse. The aim of our study was to investigate the effect of self-training in PBLS. We conducted a prospective controlled trial enrolling nurses from pediatric and maternity wards (n=29 in each group). Self-training, including a manikin and access to a web-based video on PBLS, was compared with a 2-h instructor-led course. Two weeks after training, all participants were tested in a mock scenario of pediatric cardiac arrest. Fifteen parameters equivalent to the steps in the PBLS algorithm - for example, effective ventilations, effective chest compressions, calling for help, and correct sequence of actions, were evaluated and rated dichotomously (1=approved or 0=not approved). No difference was observed in the baseline demographics between the self-training group and the instructor-led group. The participants in the self-training group accessed the website 2±1.5 times (mean±SD) and spent 41±25 min on the site. There was no significant difference between the two groups in the overall average score (10.5 in the self-training group vs. 10.0 in the instructor-led group, P=0.51) or in any of the 15 parameters. After the study, all participants felt that they had improved their skills and felt capable of performing PBLS. Self-training is not statistically different to instructor-led training in teaching PBLS. Self-evaluated confidence improved, but showed no difference between groups. PBLS may be disseminated through self-training.

  14. Reduce conflicts in traditional merariq traditions through the long tradition of the tribal people of sasak lombok

    Science.gov (United States)

    Sarmini; Nadiroh, Ulin; Saeun Fahmi, Muhammad

    2018-01-01

    Marriage is a container for framing the inner-to-heart relationship, the bond of love and affection between a man and woman to nurture a joy of happiness. This study aims to find out how the process and stages in traditional merariq traditions in the Sasak people, conflicts arising from merariq traditions, and reduce conflict through the tradition of selabar. The method used in this research is qualitative analysis method. In the process, merariq tradition is done by kidnapping the bride without the knowledge of the parents or the family of the women. There are several stages that must be passed by the bride and groom in the tradition merariq, namely: besejati, nyelabar, bait wali, sorong serah dan nyongkolang. Conflict that often arises, for internal family, merariq often become a place of coercion against the female family. For society, merariq impact on disruption of harmony of social life. In order to reduce the conflicts done selabar tradition, the tragedy is regarded as an alternative problem solving in the form of negotiations between the bride and groom’s family and the bride-to-be relating to ajikrame and pisuke transactions.

  15. Design of a cylindrical LED substrate without radiator

    Science.gov (United States)

    Tang, Fan; Guo, Zhenning

    2017-12-01

    To reduce the weight and production costs of light-emitting diode (LED) lamps, we applied the principle of the chimney effect to design a cylindrical LED substrate without a radiator. We built a 3D model by using Solidworks software and applied the flow simulation plug-in to conduct model simulation, thereby optimizing the heat source distribution and substrate thickness. The results indicate that the design achieved optimal cooling with a substrate with an upper extension length of 35 mm, a lower extension length of 8 mm, and a thickness of 1 mm. For a substrate of those dimensions, the highest LED chip temperature was 64.78 °C, the weight of the substrate was 35.09 g, and R jb = 7.00 K/W. If the substrate is powered at 8, 10, and 12 W, its temperature meets LED safety requirements. In physical tests, the highest temperature for a physical 8 W cylindrical LED substrate was 66 °C, which differed by only 1.22 °C from the simulation results, verifying the validity of the simulation. The designed cylindrical LED substrate can be used in high-power LED lamps that do not require radiators. This design is not only excellent for heat dissipation, but also for its low weight, low cost, and simplicity of manufacture.

  16. Integrating Traditional Ecological Knowledge and Ecological Science: a Question of Scale

    Directory of Open Access Journals (Sweden)

    Catherine A. Gagnon

    2009-12-01

    Full Text Available The benefits and challenges of integrating traditional ecological knowledge and scientific knowledge have led to extensive discussions over the past decades, but much work is still needed to facilitate the articulation and co-application of these two types of knowledge. Through two case studies, we examined the integration of traditional ecological knowledge and scientific knowledge by emphasizing their complementarity across spatial and temporal scales. We expected that combining Inuit traditional ecological knowledge and scientific knowledge would expand the spatial and temporal scales of currently documented knowledge on the arctic fox (Vulpes lagopus and the greater snow goose (Chen caerulescens atlantica, two important tundra species. Using participatory approaches in Mittimatalik (also known as Pond Inlet, Nunavut, Canada, we documented traditional ecological knowledge about these species and found that, in fact, it did expand the spatial and temporal scales of current scientific knowledge for local arctic fox ecology. However, the benefits were not as apparent for snow goose ecology, probably because of the similar spatial and temporal observational scales of the two types of knowledge for this species. Comparing sources of knowledge at similar scales allowed us to gain confidence in our conclusions and to identify areas of disagreement that should be studied further. Emphasizing complementarities across scales was more powerful for generating new insights and hypotheses. We conclude that determining the scales of the observations that form the basis for traditional ecological knowledge and scientific knowledge represents a critical step when evaluating the benefits of integrating these two types of knowledge. This is also critical when examining the congruence or contrast between the two types of knowledge for a given subject.

  17. An exploration of on-line access by non-traditional students in higher education: a case study.

    Science.gov (United States)

    Dearnley, Chris; Dunn, Ginny; Watson, Sue

    2006-07-01

    The nature of Higher Education (HE) has seen many changes throughout the last decade. The agenda for widening participation in HE has led to an increase in the number of students with a broader range of educational backgrounds. At the same time there has been a surge in the development of digitalisation and the convergence of computing and telecommunications technologies available for use in education. This paper discusses the outcomes of a case study, conducted in a School of Health Studies within a northern English University, which identified the extent to which 'non-traditional' students access on-line learning facilities, such as virtual learning environments and library networks, and what factors enhanced or formed barriers to access. 'Non-traditional' students, for the purpose of this study, were defined as mature students who were returning to higher education after a considerable break. The outcomes indicated that skill deficit is a major obstacle for many 'non-traditional' students. The paper explores this issue in depth and suggests potential ways forward for the delivery of technology supported learning for 'non-traditional' students in Higher Education.

  18. White LEDs as broad spectrum light sources for spectrophotometry: demonstration in the visible spectrum range in a diode-array spectrophotometric detector.

    Science.gov (United States)

    Piasecki, Tomasz; Breadmore, Michael C; Macka, Mirek

    2010-11-01

    Although traditional lamps, such as deuterium lamps, are suitable for bench-top instrumentation, their compatibility with the requirements of modern miniaturized instrumentation is limited. This study investigates the option of utilizing solid-state light source technology, namely white LEDs, as a broad band spectrum source for spectrophotometry. Several white light LEDs of both RGB and white phosphorus have been characterized in terms of their emission spectra and energy output and a white phosphorus Luxeon LED was then chosen for demonstration as a light source for visible-spectrum spectrophotometry conducted in CE. The Luxeon LED was fixed onto the base of a dismounted deuterium (D(2) ) lamp so that the light-emitting spot was geometrically positioned exactly where the light-emitting spot of the original D(2) lamp is placed. In this manner, the detector of a commercial CE instrument equipped with a DAD was not modified in any way. As the detector hardware and electronics remained the same, the change of the deuterium lamp for the Luxeon white LED allowed a direct comparison of their performances. Several anionic dyes as model analytes with absorption maxima between 450 and 600 nm were separated by CE in an electrolyte of 0.01 mol/L sodium tetraborate. The absorbance baseline noise as the key parameter was 5 × lower for the white LED lamp, showing clearly superior performance to the deuterium lamp in the available, i.e. visible part of the spectrum. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Traditional Uses, Phytochemistry, and Pharmacology of Olea europaea (Olive)

    Science.gov (United States)

    Hashmi, Muhammad Ali; Khan, Afsar; Hanif, Muhammad; Farooq, Umar; Perveen, Shagufta

    2015-01-01

    Aim of the Review. To grasp the fragmented information available on the botany, traditional uses, phytochemistry, pharmacology, and toxicology of Olea europaea to explore its therapeutic potential and future research opportunities. Material and Methods. All the available information on O. europaea was collected via electronic search (using Pubmed, Scirus, Google Scholar, and Web of Science) and a library search. Results. Ethnomedical uses of O. europaea are recorded throughout the world where it has been used to treat various ailments. Phytochemical research had led to the isolation of flavonoids, secoiridoids, iridoids, flavanones, biophenols, triterpenes, benzoic acid derivatives, isochromans, and other classes of secondary metabolites from O. europaea. The plant materials and isolated components have shown a wide spectrum of in vitro and in vivo pharmacological activities like antidiabetic, anticonvulsant, antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antiviral, antihypertensive, anticancer, antihyperglycemic, antinociceptive, gastroprotective, and wound healing activities. Conclusions. O. europaea emerged as a good source of traditional medicine for the treatment of various ailments. The outcomes of phytochemical and pharmacological studies reported in this review will further expand its existing therapeutic potential and provide a convincing support to its future clinical use in modern medicine. PMID:25802541

  20. Traditional Uses, Phytochemistry, and Pharmacology of Olea europaea (Olive

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Hashmi

    2015-01-01

    Full Text Available Aim of the Review. To grasp the fragmented information available on the botany, traditional uses, phytochemistry, pharmacology, and toxicology of Olea europaea to explore its therapeutic potential and future research opportunities. Material and Methods. All the available information on O. europaea was collected via electronic search (using Pubmed, Scirus, Google Scholar, and Web of Science and a library search. Results. Ethnomedical uses of O. europaea are recorded throughout the world where it has been used to treat various ailments. Phytochemical research had led to the isolation of flavonoids, secoiridoids, iridoids, flavanones, biophenols, triterpenes, benzoic acid derivatives, isochromans, and other classes of secondary metabolites from O. europaea. The plant materials and isolated components have shown a wide spectrum of in vitro and in vivo pharmacological activities like antidiabetic, anticonvulsant, antioxidant, anti-inflammatory, immunomodulatory, analgesic, antimicrobial, antiviral, antihypertensive, anticancer, antihyperglycemic, antinociceptive, gastroprotective, and wound healing activities. Conclusions. O. europaea emerged as a good source of traditional medicine for the treatment of various ailments. The outcomes of phytochemical and pharmacological studies reported in this review will further expand its existing therapeutic potential and provide a convincing support to its future clinical use in modern medicine.

  1. Low Cost Lithography Tool for High Brightness LED Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Hawryluk; Emily True

    2012-06-30

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

  2. 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.

  3. High Output LED-Based Profile Lighting Fixture

    DEFF Research Database (Denmark)

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

    2011-01-01

    Recent developments in power light emitting diode (LED) industry have made LEDs suitable for being efficiently used in high intensity lighting fixtures instead of the commonly used high intensity discharge (HID) lamps. A high output LEDbased profile-light fixture is presented in this paper...

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

    Science.gov (United States)

    Stamatacos, Catherine; Harrison, Janet L

    2013-01-01

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

  5. White light-emitting diodes (LEDs) using (oxy)nitride phosphors

    International Nuclear Information System (INIS)

    Xie, R-J; Hirosaki, N; Sakuma, K; Kimura, N

    2008-01-01

    (Oxy)nitride phosphors have attracted great attention recently because they are promising luminescent materials for phosphor-converted white light-emitting diodes (LEDs). This paper reports the luminescent properties of (oxy)nitride phosphors in the system of M-Si-Al-O-N (M = Li, Ca or Sr), and optical properties of white LEDs using a GaN-based blue LED and (oxy)nitride phosphors. The phosphors show high conversion efficiency of blue light, suitable emission colours and small thermal quenching. The bichromatic white LEDs exhibit high luminous efficacy (∼55 lm W -1 ) and the multi-phosphor converted white LEDs show high colour rendering index (Ra 82-95). The results indicate that (oxy)nitride phosphors demonstrate their superior suitability to use as down-conversion luminescent materials in white LEDs

  6. Colour differences in Caucasian and Oriental women's faces illuminated by white LED sources.

    Science.gov (United States)

    Melgosa, M; Richard, N; Fernández-Maloigne, C; Xiao, K; de Clermont-Gallerande, H; Jost-Boissard, S; Okajima, K

    2018-04-10

    To provide an approach to facial contrast, analysing CIELAB colour differences (ΔE* ab,10 ) and its components in women's faces from two different ethnic groups, illuminated by modern white light-emitting diodes (LEDs) or traditional illuminants recommended by the International Commission on Illumination (CIE). We performed spectrophotometric measurements of spectral reflectance factors on forehead and cheek of 87 young healthy women (50 Caucasians and 37 Orientals), plus 5 commercial red lipsticks. We considered a set of 10 white LED illuminants, representative of technologies currently available on the market, plus 8 main illuminants currently recommended by the CIE, representative of conventional incandescent, daylight, and fluorescent light sources. Under each of these 18 illuminants we analysed the magnitude and components of ΔE* ab,10 between Caucasian and Oriental women (considering cheek and forehead), as well as for cheek-forehead and cheek-lipsticks in Caucasian and Oriental women. Colour-inconstancy indices for cheek, forehead, and lipsticks were computed, assuming D65 and A as reference illuminants. ΔE* ab,10 between forehead and cheek were quantitatively and qualitatively different in Orientals and Caucasians, but discrepancies with respect to average values for 18 illuminants were small (1.5% and 5.0% for Orientals and Caucasians, respectively). ΔE* ab,10 between Caucasians and Orientals were also quantitatively and qualitatively different both for forehead and cheek, and discrepancies with respect to average values were again small (1.0% and 3.9% for forehead and cheek, respectively). ΔE* ab,10 between lipsticks and cheek were at least 2 times higher than those between forehead and cheek. Regarding ΔE* ab,10 between lipsticks and cheeks, discrepancies with respect to average values were in the range 1.5% - 12.3%, although higher values of up to 54.2% were found for a white RGB LED. This white RGB LED provided the highest average colour

  7. Conserving Local Knowledge in Traditional Healing through Knowledge Transfer

    Directory of Open Access Journals (Sweden)

    Lah Salasiah Che

    2015-01-01

    Full Text Available Local knowledge (LK basically refers to the knowledge that people in a given community have developed over time, and continues to develop, through practices and based on experiences. Local beliefs pertaining to ilmu, a central concept in Malay culture that refers to knowledge, is essential among the traditional healers. The vast repository of knowledge and its relevance to locality and local situation makes the conservation of LK a necessity.However, due to the dominance of modern knowledge, diminished inter-generational knowledge transfer has led to LK being threatened with extinction. The fact that LK is practiced by only a few these days could be due to lack of knowledge transfer to the younger generations from the traditional healers who are knowledgeable in the communities. The common transfer mode of local knowledge, usually via words of mouth, may not be sustainable because the LK could vanish when knowledgeable elders die before it is transferred or during resettlements of individuals or communities. The need to conserve LK through knowledge transfer is also pertinent for the continued sustenance of their culture by recognizing, protecting and enforcing the rights of local communities to have continued access to biological resources as well as by protecting their LK, acquired over thousand of years of experimentation and experience, about the uses of these biological resources in traditional healing. Therefore, it is important to have a governance framework to effectively protect this LK of the local communities for the continued sustenance of their culture. This conceptual paper attempts to highlight the significance of conserving LK in traditional healing via effective knowledge transfer method, which should thereafter be translated into a working governance framework that protects the knowledge as well as the holders of such knowledge.

  8. Flat-panel video resolution LED display system

    Science.gov (United States)

    Wareberg, P. G.; Kennedy, D. I.

    The system consists of a 128 x 128 element X-Y addressable LED array fabricated from green-emitting gallium phosphide. The LED array is interfaced with a 128 x 128 matrix TV camera. Associated electronics provides for seven levels of grey scale above zero with a grey scale ratio of square root of 2. Picture elements are on 0.008 inch centers resulting in a resolution of 125 lines-per-inch and a display area of approximately 1 sq. in. The LED array concept lends itself to modular construction, permitting assembly of a flat panel screen of any desired size from 1 x 1 inch building blocks without loss of resolution. A wide range of prospective aerospace applications exist extending from helmet-mounted systems involving small dedicated arrays to multimode cockpit displays constructed as modular screens. High-resolution LED arrays are already used as CRT replacements in military film-marking reconnaissance applications.

  9. Electrical efficiency and droop in MQW LEDs

    Science.gov (United States)

    Malyutenko, V. K.

    2014-02-01

    It is believed that low power conversion efficiency in commercial MQW LEDs occurs as a result of efficiency droop, current-induced dynamic degradation of the internal quantum efficiency, injection efficiency, and extraction efficiency. Broadly speaking, all these "quenching" mechanisms could be referred to as the optical losses. The vast advances of high-power InGaN and AlGaInP MQW LEDs have been achieved by addressing these losses. In contrast to these studies, in this paper we consider an alternative approach to make high-power LEDs more efficient. We identify current-induced electrical efficiency degradation (EED) as a strong limiting factor of power conversion efficiency. We found that EED is caused by current crowding followed by an increase in current-induced series resistance of a device. By decreasing the current spreading length, EED also causes the optical efficiency to degrade and stands for an important aspect of LED performance. This paper gives scientists the opportunity to look for different attributes of EED.

  10. Bridgeless SEPIC PFC Converter for Multistring LED Driver

    Science.gov (United States)

    Jha, Aman; Singh, Bhim

    2018-05-01

    This paper deals with Power Factor Correction (PFC) in Low Voltage High Current (LVHC) multi-string light emitting diode (LED) using a bridgeless (BL) single ended primary inductance converter (SEPIC). This application is designed for large area LED lighting with illumination control. A multi-mode LED dimming technique is used for the lighting control. The BL-SEPIC PFC converter is used as a load emulator for high power factor. The regulated low voltage from flyback converter is a source power to the synchronous buck converters for multi-string LED driver and forced cooling system for LED junction. The BL-SEPIC PFC converter inductor design is based on Discontinuous Inductor Current Modes (DICM) which provides good PFC at low cost. Test results are found quite satisfactory for universal input AC (90-265 V). There is significant improvement in the power factor and input current Total Harmonic Distortion (THD) with good margin of harmonic limits for lighting IEC 61000-3-2 Class C.

  11. Supporting Online, Non-Traditional Students through the Introduction of Effective E-Learning Tools in a Pre-University Tertiary Enabling Programme

    Science.gov (United States)

    Lambrinidis, George

    2014-01-01

    The increasing number of external students enrolling at Charles Darwin University has led to the university investing in new technologies to provide better support for students studying online. Many students, however, come from non-traditional backgrounds and lack some of the skills and confidence to participate successfully in an e-learning…

  12. Integrated parabolic nanolenses on MicroLED color pixels

    Science.gov (United States)

    Demory, Brandon; Chung, Kunook; Katcher, Adam; Sui, Jingyang; Deng, Hui; Ku, Pei-Cheng

    2018-04-01

    A parabolic nanolens array coupled to the emission of a nanopillar micro-light emitting diode (LED) color pixel is shown to reduce the far field divergence. For a blue wavelength LED, the total emission is 95% collimated within a 0.5 numerical aperture zone, a 3.5x improvement over the same LED without a lens structure. This corresponds to a half-width at half-maximum (HWHM) line width reduction of 2.85 times. Using a resist reflow and etchback procedure, the nanolens array dimensions and parabolic shape are formed. Experimental measurement of the far field emission shows a HWHM linewidth reduction by a factor of 2x, reducing the divergence over the original LED.

  13. Aboriginal traditional knowledge - panel presentation

    International Nuclear Information System (INIS)

    Barnaby, J.; Duiven, M.; Garibaldi, A.; McGregor, D.; Straker, J.; Patton, P.

    2011-01-01

    Aboriginal peoples in Canada are playing a more active role in land use and resource management decisions around industrial development in their traditional territories and communities. Both indigenous and non-indigenous people are therefore increasing efforts to collaborate in decision-making and to effectively interweave Aboriginal Traditional Knowledge (ATK) and Western knowledge or science. Challenges exist, in part because non-Aboriginal people often find it difficult to define ATK and to understand the differences from Western perspectives. ATK is best defined as a holistic system that involves not only knowledge but principles of conduct and a strong relationship component. Research has focused on approaches to more easily bridge ATK and Western knowledge, through dialogue/negotiation and shared decision-making that is complementary to both. There are some examples of organizations and communities that have achieved success in this bridging of the two forms of knowledge. The Skeena Fisheries Commission (SFC) in British Columbia manages the fish resource in the Skeena Watershed and generates scientific research through links to ATK. The observations of indigenous people about apparent changes in the resource are subjected to scientific assessment, which has led to changes in how fish are caught, and in how and by whom data is collected. Traditional knowledge has also been incorporated into the reclamation of lands and species in Fort McKay, Alberta, an indigenous community whose traditional way of life has been significantly affected by development of the oil sands. New models have been developed to incorporate ATK into long-term planning for land use. This includes using ATK to develop a 50-to 60-year projection of probable future effects from development and to build strategies for achieving a 'desired future landscape.' To plan for post-mining land reclamation projects, another project makes use of cultural keystone species (CKS), through which

  14. Aboriginal traditional knowledge - panel presentation

    Energy Technology Data Exchange (ETDEWEB)

    Barnaby, J. [JB, Consultant, Paris (France); Duiven, M. [Skeena Fisheries Commission, Kispiox, BC (Canada); Garibaldi, A. [Integral Ecology Group, Ltd., Victoria, BC (Canada); McGregor, D. [Univ. of Toronto, Dept. of Geography and Aboriginal Studies, Toronto, ON (Canada); Straker, J. [Integral Ecology Group, Ltd., Victoria, BC (Canada); Patton, P. [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2011-07-01

    Aboriginal peoples in Canada are playing a more active role in land use and resource management decisions around industrial development in their traditional territories and communities. Both indigenous and non-indigenous people are therefore increasing efforts to collaborate in decision-making and to effectively interweave Aboriginal Traditional Knowledge (ATK) and Western knowledge or science. Challenges exist, in part because non-Aboriginal people often find it difficult to define ATK and to understand the differences from Western perspectives. ATK is best defined as a holistic system that involves not only knowledge but principles of conduct and a strong relationship component. Research has focused on approaches to more easily bridge ATK and Western knowledge, through dialogue/negotiation and shared decision-making that is complementary to both. There are some examples of organizations and communities that have achieved success in this bridging of the two forms of knowledge. The Skeena Fisheries Commission (SFC) in British Columbia manages the fish resource in the Skeena Watershed and generates scientific research through links to ATK. The observations of indigenous people about apparent changes in the resource are subjected to scientific assessment, which has led to changes in how fish are caught, and in how and by whom data is collected. Traditional knowledge has also been incorporated into the reclamation of lands and species in Fort McKay, Alberta, an indigenous community whose traditional way of life has been significantly affected by development of the oil sands. New models have been developed to incorporate ATK into long-term planning for land use. This includes using ATK to develop a 50-to 60-year projection of probable future effects from development and to build strategies for achieving a 'desired future landscape.' To plan for post-mining land reclamation projects, another project makes use of cultural keystone species (CKS), through which

  15. Estimated annual incomes of South African traditional healers as generated by their practices and sales of their pre-modern traditional health products for 2015/2016

    Directory of Open Access Journals (Sweden)

    Gabriel Louw

    2017-02-01

    . Some traditional medicines are available from well-established outlets like pharmacies, modern-day health-shops and allied-traditional healthcare professionals like the statutory recognised homeopaths, naturopaths, phytopaths and ethnopaths. These medicines have to adhere to a formal manufacturing and scientific foundation, while traditional healers rely on self-made, pre-modern and untested indigenous mixtures. This lack in differentiation and scientific foundation has clouded the true ownership of traditional health and medical products as viewed and understood under the definition Traditional African Medicines (TAM. This vagueness also obstructs the compilation of a profile of the incomes generated by the various role players in their practices and by manufacturing and selling of traditional medical and health products. The end result is a misrepresentation of sales statistics in South African literature on traditional healers and their self-made health products and untested mixtures. Conclusion The present-day statistics cited in literature of annual incomes of between R2 billion (R2,000 million and R3.4 billion (R3,400 million, roughly an average of R2.7 billion (R2,700 million, from the sales of traditional health products and mixtures by South African traditional healers, are false. What is more, South African literature generally reflects an erroneous classification of who the true manufacturers and sellers of traditional health and medical products are, and what “traditional medicines” really mean. This has led to an acceptance of South African traditional healers and their untested and risky health products and mixtures based on a misconception that they are the true manufacturers, sellers and owners of TAM. The most prominent role player in the manufacturing and selling of traditional medicines and the true income-generator seems to be the formal South African industry of complementary/-alternative medicines (CAM. This comprehensive, well-established and

  16. Setup of a LED light-pulser system for the OLYMPUS experiment; Aufbau eines LED-Lichtpulsersystems fuer das OLYMPUS-Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rehman, Waqaas

    2011-12-15

    The aim of this thesis consists in the construction and test of an external light-calibration system based on light-emitting diodes (LED) for the application at the symmetric Moller/Bhabha (SYMB) luminosity monitor. In chapter 2 the theoretical foundations of the OLYMPUS experiment, especially of the SYMB luminosity monitor are explained. Thereafter in chapter 3 the details of the setup of the OLYMPUS experiment and the fundamental properties of the SYMB detectors are discussed. In chapter 4 the whole concept of the LED light-pulser system is treated. In chapter 5 then test measurements with the ready LED light-pulser system are described. Thereby the light source shall be optimized in the shape that thereafter light pulses with short signal width are producable. Also different measurements for the unique characterization of the systems are performed. In chapter 6 light-intensity measurements during the operation of the LED light-pulser system are described.

  17. Growth of GaN nanostructures with polar and semipolar orientations for the fabrication of UV LEDs

    Science.gov (United States)

    Brault, Julien; Damilano, Benjamin; Courville, Aimeric; Leroux, Mathieu; Kahouli, Abdelkarim; Korytov, Maxim; Vennéguès, Philippe; Randazzo, Gaetano; Chenot, Sébastien; Vinter, Borge; De Mierry, Philippe; Massies, Jean; Rosales, Daniel; Bretagnon, Thierry; Gil, Bernard

    2014-03-01

    (Al,Ga)N light emitting diodes (LEDs), emitting over a large spectral range from 360 nm (GaN) down to 210 nm (AlN), have been successfully fabricated over the last decade. Clear advantages compared to the traditional mercury lamp technology (e.g. compactness, low-power operation, lifetime) have been demonstrated. However, LED efficiencies still need to be improved. The main problems are related to the structural quality and the p-type doping efficiency of (Al,Ga)N. Among the current approaches, GaN nanostructures, which confine carriers along both the growth direction and the growth plane, are seen as a solution for improving the radiative recombination efficiency by strongly reducing the impact of surrounding defects. Our approach, based on a 2D - 3D growth mode transition in molecular beam epitaxy, can lead to the spontaneous formation of GaN nanostructures on (Al,Ga)N over a broad range of Al compositions. Furthermore, the versatility of the process makes it possible to fabricate nanostructures on both (0001) oriented "polar" and (11 2 2) oriented "semipolar" materials. We show that the change in the crystal orientation has a strong impact on the morphological and optical properties of the nanostructures. The influence of growth conditions are also investigated by combining microscopy (SEM, TEM) and photoluminescence techniques. Finally, their potential as UV emitters will be discussed and the performances of GaN / (Al,Ga)N nanostructure-based LED demonstrators are presented.

  18. A review of passive thermal management of LED module

    NARCIS (Netherlands)

    Ye, H.; Sau, K.; Zeijl, H. van; Gielen, A.W.J.; Zhang, G.

    2011-01-01

    Recently, the high-brightness LEDs have begun to be designed for illumination application. The increased electrical currents used to drive LEDs lead to thermal issues. Thermal management for LED module is a key design parameter as high operation temperature directly affects their maximum light

  19. Kangkilo Oral Tradition: Reflection of Sufism and Political Powers in Buton Community

    Directory of Open Access Journals (Sweden)

    Hamiruddin Udu

    2017-01-01

    Full Text Available Kangkilo oral tradition is a form of holiness ritual. The values ?? can realize Islamic ritual and social pieties. However, the pursuit of technology results to facilitate the achievement of material according to human needs has made this tradition endangered. This study aimed to analyze the discourse structure, reflection of Sufism and political powers in function and meaning, and also inheritance strategies of kangkilo in Buton community. Data were collected by using an ethnographic approach and analyzed by using qualitative methods. The results showed that the discourse structure, function, and meaning of kangkilo is unique, different from other oral traditions ever observed. The values contained some Sufism understandings and political policies of powers. From the aspect of the formula, for example, although kangkilo is qualified as a form of oral tradition, but actors of kangkilo still expected to follow the text which has been taught, can not to change the text appropriate to the circumstances that exist around kangkilo actors are, as a formula in oral tradition suggested by experts such as Albert B. Lord. This is related to the presence of kangkilo as a religious ritual. Kangkilo oral tradition is a ritual holiness in Buton influenced by Sufism understanding in MartabatTujuh. By the influence of Sufism in kangkilo, have made this holiness ritual different with the other ritual of purity which is known in the Islamic world. Kangkilo is used also as a marker for people who live in Buton as Butonese. The values in kangkilo are used as values standard for social and cultural development in Buton community. From the aspect of meaning, chastity teachings both theocentric and anthropocentric in kangkilo oral tradition values led the creation of a harmonious of life, both in man's relationship with God, between one people and other people, as well as between the rulers and the people, and between people and nature universe. Given the importance

  20. Understanding traditional African healing.

    Science.gov (United States)

    Mokgobi, M G

    2014-09-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of traditional healers as well as the role of traditional healers in their communities are discussed. In conclusion, the services of traditional healers go far beyond the uses of herbs for physical illnesses. Traditional healers serve many roles which include but not limited to custodians of the traditional African religion and customs, educators about culture, counselors, social workers and psychologists.

  1. 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

  2. A Comparative Study on the Motivation and Attitudes of Language Learners of Online Distance and Traditional In-Classroom Education

    Science.gov (United States)

    Genc, Gulten; Kulusakli, Emine; Aydin, Savas

    2016-01-01

    In recent years, the increase in the use of computer and the internet has led to a change in the traditional concept of formal education today. Distance learning as a more student-centered system has been frequently used at universities. In this context, education has been applied to the individuals consisting of all age groups in accordance with…

  3. Physiotherapy-led arthroplasty review clinic: a preliminary outcomes analysis.

    Science.gov (United States)

    Large, Kate E; Page, Carolyn J; Brock, Kim; Dowsey, Michelle M; Choong, Peter F M

    2014-11-01

    With the rising demand for Orthopaedics in the healthcare sector, service delivery innovations need to be explored to accommodate the increasing workload. Senior Musculoskeletal Physiotherapists have the specialised skills in the assessment of musculoskeletal conditions to determine the impact of surgery on patient outcomes. The aim of the present study was to compare outcomes between a physiotherapy-led arthroplasty review clinic (PT clinic) and the traditional model of orthopaedic surgeon review (OS clinic) after hip and knee replacement. This study was a retrospective case-controlled audit using a comprehensive database. Twenty-four patients who had a hip arthroplasty and 52 patients who had a knee arthroplasty were reviewed solely by the PT clinic at 3, 6 and 12 months after surgical reviews. These patients were matched 1:2 against patients seen only by the OS clinic. The outcome measures included International Knee Score (IKS), Harris Hip Score (HHS) and the Short Form (SF)-12. There were no significant differences in HHS or SF-12 scores for patients after hip arthroplasty. Significant differences for knee arthroplasty were observed favouring the PT clinic; IKS, PT clinic 147.6 (37.07), OS clinic 135.4 (35.68), P≤0.01, and physical component of the SF-12, PT clinic 41.98 (10.45), OS clinic 37.20 (10.44), Pphysiotherapy-led arthroplasty review clinic appears to be a safe and effective service alternative to reviews conducted by orthopaedic surgeons. WHAT IS KNOWN ABOUT THE TOPIC?: Osteoarthritis (OA) is a leading cause of musculoskeletal pain and disability and the burden of the disease is rapidly increasing. Joint arthroplasty surgery is the mainstay of treatment for people with end-stage OA; it is a high-cost, high-volume procedure that dominates surgical wait lists around Australia. Long-term follow up is encouraged by the Arthroplasty Society of Australia and endorsed by the Australian Orthopaedics Association, but it is acknowledged that it is impossible

  4. LED power consumption in joint illumination and communication system

    NARCIS (Netherlands)

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

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

  5. Visual ergonomic evaluations on four different designs of LED traffic signs

    Science.gov (United States)

    Chen, Yi-Chun; Huang, Ting-Yuan; Lee, Tsung-Xian; Sun, Ching-Cherng

    2017-08-01

    To investigate the legibility and visual comfort of LED traffic signs, an ergonomic experiment is performed on four custom-designed LED traffic signs, including three self-luminous ones as LED lightbox, LED backlight and regional LED backlight, and one non-self-luminous sign with external LED lighting. The four signs are hanged side-by-side and evaluated by observers through questionnaires. The signage dimension is one-sixth of the real freeway traffic signs, and the observation distance is 25 m. The luminance of three self-luminous signs is 216 cd/m2. The illuminance of external LED lighting is 400 lux on the traffic sign. The ambient illuminance is 2.8 and 6.0 lux in two rounds. The results show that self-luminous traffic signs provide superior legibility, visual comfort and user preference than the non-self-luminous one. Among the three self-luminous signs, regional LED backlight is most susceptible to the ambient illumination. LED lightbox has significantly better preference score than LED backlight under darker ambient lighting. Only LED lightbox has significantly better visual comfort than external LED lighting in the brighter environment. Based on the four LED traffic signs evaluated in this study, we suggest LED lightbox as the prior choice. Further investigations on the effect of ambient illumination and other designs of self-luminous traffic signs are in progress.

  6. 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

  7. 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.

  8. A transition to white LED increases ecological impacts of nocturnal illumination on aquatic primary producers in a lowland agricultural drainage ditch.

    Science.gov (United States)

    Grubisic, Maja; van Grunsven, Roy H A; Manfrin, Alessandro; Monaghan, Michael T; Hölker, Franz

    2018-05-14

    The increasing use of artificial light at night (ALAN) has led to exposure of freshwater ecosystems to light pollution worldwide. Simultaneously, the spectral composition of nocturnal illumination is changing, following the current shift in outdoor lighting technologies from traditional light sources to light emitting diodes (LED). LEDs emit broad-spectrum white light, with a significant amount of photosynthetically active radiation, and typically a high content of blue light that regulates circadian rhythms in many organisms. While effects of the shift to LED have been investigated in nocturnal animals, its impact on primary producers is unknown. We performed three field experiments in a lowland agricultural drainage ditch to assess the impacts of a transition from high-pressure sodium (HPS) to white LED illumination (color temperature 4000 K) on primary producers in periphyton. In all experiments, we compared biomass and pigment composition of periphyton grown under a natural light regime to that of periphyton exposed to nocturnal HPS or, consecutively, LED light of intensities commonly found in urban waters (approximately 20 lux). Periphyton was collected in time series (1-13 weeks). We found no effect of HPS light on periphyton biomass; however, following a shift to LED the biomass decreased up to 62%. Neither light source had a substantial effect on pigment composition. The contrasting effects of the two light sources on biomass may be explained by differences in their spectral composition, and in particular the blue content. Our results suggest that spectral composition of the light source plays a role in determining the impacts of ALAN on periphyton and that the ongoing transition to LED may increase the ecological impacts of artificial lighting on aquatic primary producers. Reduced biomass in the base of the food web can impact ecosystem functions such as productivity and food supply for higher trophic levels in nocturnally-lit ecosystems. Copyright

  9. Tradition

    DEFF Research Database (Denmark)

    Otto, Ton

    2016-01-01

    : beliefs, practices, institutions, and also things. In this sense, the meaning of the term in social research is very close to its usage in common language and is not always theoretically well developed (see Shils, 1971: 123). But the concept of tradition has also been central to major theoretical debates...... on the nature of social change, especially in connection with the notion of modernity. Here tradition is linked to various forms of agency as a factor of both stability and intentional change....

  10. 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.

  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. Scalable, Economical Fabrication Processes for Ultra-Compact Warm-White LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Lowes, Ted [Cree, Inc., Durham, NC (United States)

    2016-01-31

    Conventional warm-white LED component fabrication consists of a large number of sequential steps which are required to incorporate electrical, mechanical, and optical functionality into the component. Each of these steps presents cost and yield challenges which multiply throughout the entire process. Although there has been significant progress in LED fabrication over the last decade, significant advances are needed to enable further reductions in cost per lumen while not sacrificing efficacy or color quality. Cree conducted a focused 18-month program to develop a new low-cost, high-efficiency light emitting diode (LED) architecture enabled by novel large-area parallel processing technologies, reduced number of fabrication steps, and minimized raw materials use. This new scheme is expected to enable ultra-compact LED components exhibiting simultaneously high efficacy and high color quality. By the end of the program, Cree fabricated warm-white LEDs with a room-temperature “instant on” efficacy of >135 lm/W at ~3500K and 90 CRI (when driven at the DOE baseline current density of 35 A/cm2). Cree modified the conventional LED fabrication process flow in a manner that is expected to translate into simultaneously high throughput and yield for ultra-compact packages. Building on its deep expertise in LED wafer fabrication, Cree developed these ultra-compact LEDs to have no compromises in color quality or efficacy compared to their conventional counterparts. Despite their very small size, the LEDs will also be robustly electrically integrated into luminaire systems with the same attach yield as conventional packages. The versatility of the prototype high-efficacy LED architecture will likely benefit solid-state lighting (SSL) luminaire platforms ranging from bulbs to troffers. We anticipate that the prototype LEDs will particularly benefit luminaires with large numbers of distributed compact packages, such as linear and area luminaires (e.g. troffers). The fraction of

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

    African Journals Online (AJOL)

    Journal of Fundamental and Applied Sciences ... operating conditions of LEDs at the design stage, taking into account a cooling system in use. ... The created models will allow to reveal unfavorable thermal operating modes for LEDs and, ...

  14. CONSUMERS’ BRAND EQUITY PERCEPTIONS OF TRADITIONAL AND NON-TRADITIONAL BRANDS

    OpenAIRE

    Catli, Ozlem; Ermec Sertoglu, Aysegul; Ors, Husniye

    2017-01-01

    Thisstudy aims to compare consumers' brand perception of traditional brands withbrand perceptions of non-traditional brands.  Consumers livingin Ankara constitute the universe of work, and data were gathered in aface-to-face interview using the survey method. the demographic characteristicsof the participants was prepared with the aim of evaluating and comparing onetraditional brand and one non traditional brand of brand equity related to thebrand equity by the participants. According to...

  15. Protection against methanol-induced retinal toxicity by LED photostimulation

    Science.gov (United States)

    Whelan, Harry T.; Wong-Riley, Margaret T. T.; Eells, Janis T.

    2002-06-01

    We have initiated experiments designed to test the hypothesis that 670-nm Light-Emitting Diode (LED) exposure will attenuate formate-induced retinal dysfunction in a rodent model of methanol toxicity. Methanol intoxication produces toxic injury to the retina. The toxic metabolite formed in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit cytochrome oxidase activity. 670-nm LED light has been hypothesized to act by stimulating cytochrome oxidase activity. To test this hypothesis, one group of animals was intoxicated with methanol, a second group was intoxicated with methanol and LED-treated and a third group was untreated. LED treatment (670 nm for 1 min 45 seconds equals 50 mW/cm2, 4 joules/cm2) was administered at 5, 25, and 50 hours after the initial dose of methanol. At 72 hours of methanol intoxication, retinal function was assessed by measurement of ERG responses and retinas were prepared for histologic analysis. ERG responses recorded in methanol-intoxicated animals revealed profound attenuation of both rod-dominated and UV-cone mediated responses. In contrast, methanol- intoxicated animals exposed to LED treatment exhibited a nearly complete recovery of rod-dominated ERG responses and a slight improvement of UV-cone mediated ERG responses. LED treatment also protected the retina against the histopathologic changes produced by formate in methanol intoxication. These data provide evidence that LED phototherapy protects the retina against the cytotoxic actions of formate and are consistent with the hypothesis that LED photostimulation improves mitochondrial respiratory chain function.

  16. Traditional heritage and trends of modernization

    Directory of Open Access Journals (Sweden)

    Milivojević Snežana M.

    2013-01-01

    Full Text Available The main thesis of contemporary sociological theory and liberal-democratic political doctrine of the 'end of history', 'open society', globalization as a world-historical process is also the thesis about finally liberated the individual and autonomous personality 'of our time'. Modernization theorists from Marx argued that economic development brings changes. Actually, economic development is connected with breakthrough from absolute norms and values towards rationality, tolerance, trust, and participation, so transition from traditionalism to modernism according to theory affects forms of value. This paper examines relationship between values and social (political, economic, cultural transformation as well as the extent to which the validity transformation threatened severe and dramatic social events during last decade. There still remains a dilemma for modern scientific and philosophic thought: is the individual truly free of the pressure of belonging to various types of group compounds like class, ethno-cultural background, family background, gender etc, or have individualization and reflexivity led to an increase in isolation, narcissism, apathy, cynicism, exclusion, marginal position in society, emphasizing materialistic goals and inability to control their own lives.

  17. Development and Performance Assessment of White LED Dimmer

    Science.gov (United States)

    Maiti, Pradip Kr.; Roy, Biswanath

    2017-10-01

    A microcontroller based electronic dimmer is developed using pulse width modulation technique. This dimmer is controllable by infra-red remote within a distance of 4 m and can be electrically connected between LED module and its driver. The performance of a developed LED dimmer is assessed on basis of variation of the photometric parameters of commercially available warm white and cool white LED luminaire used in indoor lighting applications. Four equally spaced dimming levels are considered to measure luminous efficacy, spectral power distribution, CIE 1931 chromaticity coordinates, CIE 1976 CIELUV color difference, correlated color temperature, general color rendering index and one specific color rendering index for saturated red color sample. Variations of above parameters are found out with reference to the values measured at rated voltage without the developed dimmer. Analysis of experimentally measured data shows that the developed LED dimmer is capable to vary light output of the WLED luminaire within a range of 25-100% without appreciable variation of its photometric and color parameters. The only exception is observed for the luminous efficacy parameter where it shows about 17 and 14.7% reduction for warm white and cool white LED luminaire at 25% dimming level.

  18. Unidirectional visible light communication and illumination with LEDs

    NARCIS (Netherlands)

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

    2016-01-01

    Visible light communication (VLC) with light emitting diodes (LEDs) has attracted interest for interactive and networked lighting control, and consumer infotainment applications. In this paper, we propose an LED system for jointly achieving unidirectional VLC while providing flicker-free

  19. Regression analysis for LED color detection of visual-MIMO system

    Science.gov (United States)

    Banik, Partha Pratim; Saha, Rappy; Kim, Ki-Doo

    2018-04-01

    Color detection from a light emitting diode (LED) array using a smartphone camera is very difficult in a visual multiple-input multiple-output (visual-MIMO) system. In this paper, we propose a method to determine the LED color using a smartphone camera by applying regression analysis. We employ a multivariate regression model to identify the LED color. After taking a picture of an LED array, we select the LED array region, and detect the LED using an image processing algorithm. We then apply the k-means clustering algorithm to determine the number of potential colors for feature extraction of each LED. Finally, we apply the multivariate regression model to predict the color of the transmitted LEDs. In this paper, we show our results for three types of environmental light condition: room environmental light, low environmental light (560 lux), and strong environmental light (2450 lux). We compare the results of our proposed algorithm from the analysis of training and test R-Square (%) values, percentage of closeness of transmitted and predicted colors, and we also mention about the number of distorted test data points from the analysis of distortion bar graph in CIE1931 color space.

  20. PV power system using hybrid converter for LED indictor applications

    International Nuclear Information System (INIS)

    Tseng, Sheng-Yu; Wang, Hung-Yuan; Chen, Chien-Chih

    2013-01-01

    Highlights: • This paper presents a LED indictor driving circuit with a PV arrays as its power source. • The perturb-and-observe method is adopted to extract the maximum power of PV arrays. • The proposed circuit structure has a less component counts and higher conversion efficiency. • A prototype of LED indictor driving circuit has been implemented to verify its feasibility. • The proposed hybrid converter is suitable for LED inductor applications. - Abstract: This paper presents a LED indictor driving circuit with a PV arrays as its power source. The LED indictor driving circuit includes battery charger and discharger (LED driving circuit). In this research, buck converter is used as a charger, and forward converter with active clamp circuit is adopted as a discharger to drive the LED indictor. Their circuit structures use switch integration technique to simplify them and to form the proposed hybrid converter, which has a less component counts, lighter weight, smaller size, and higher conversion efficiency. Moreover, the proposed hybrid converter uses a perturb-and-observe method to extract the maximum power from PV arrays. Finally, a prototype of an LED indictor driving circuit with output voltage of 10 V and output power of 20 W has been implemented to verify its feasibility. It is suitable for the LED inductor applications

  1. A HUMANISING ECONOMIC APPROACH ON COMPETITION POLICY OR HOW THE BEHAVIORAL ECONOMICS BLENDS WITH “TRADITIONAL ECONOMICS”

    Directory of Open Access Journals (Sweden)

    Liviana Andreea Niminet

    2015-07-01

    Full Text Available Behavioral are crucial for understanding both the consumer’s attitude and firms’ attitude as well as for understanding the market outcomes. The past ten years brought a lot of attention from researchers and policy-makers on the behavioral economics issue. Classical, traditional economic models rely on the assumptions of rationality and ordered preferences. Behavioral economics explores interactions between demand and supply including information framing, the use of heuristics in decision-making and time-inconsistent preferences. The research on behavioral economics has led to an extensive debate about the relative merits of both traditional and behavioral economics. First of all we propose to highlight the advantages and disadvantages of behavioral economics versus traditional economics on a very sensitive issue: the competition policy. Then we address market issues that can be solved by means of behavioral economics afterwards turning out attention to the remedies of behavioral economics and ,last but not least, the United Kingdom successful model on the matter of competition policy.

  2. CFD modeling of a UV-A LED baffled flat-plate photoreactor for environment applications: a mining wastewater case.

    Science.gov (United States)

    Devia-Orjuela, John Steven; Betancourt-Buitrago, Luis Andrés; Machuca-Martinez, Fiderman

    2018-06-02

    The use of ultraviolet light in photoreactors for wastewater treatment has become popular as an alternative of known chemical oxidative substances. UV LED light represents cheaper, robust, and versatile alternative to traditional UV lamps. In this study, it was designed and evaluated a photoreactor with an approach of chemical fluid dynamics (CFD) and experimental validation. The evaluation consisted of (1) CFD velocity profile analysis, (2) characterization of the average light distribution with potassium ferrioxalate actinometry, (3) degradation of a typical recalcitrant metallic cyanocomplex Fe(CN) 6 3- , and (4) scavenger effect analysis in the photodegradation using potassium persulfate. Actinometrical essay concluded that the system was able to receive 1.93 μE/s. The reactor operated under turbulent regime and best result for Fe(CN) 6 3- degradation was obtained at 4 h of operation, using 5-W UV-A LEDs, with pH ~ 7 and 10 mM de S 2 O 8 2- . Baffled photoreactor demonstrated to be useful for this type of illumination and wastewater treatment.

  3. Understanding traditional African healing

    OpenAIRE

    MOKGOBI, M.G.

    2014-01-01

    Traditional African healing has been in existence for many centuries yet many people still seem not to understand how it relates to God and religion/spirituality. Some people seem to believe that traditional healers worship the ancestors and not God. It is therefore the aim of this paper to clarify this relationship by discussing a chain of communication between the worshipers and the Almighty God. Other aspects of traditional healing namely types of traditional healers, training of tradition...

  4. The Rise of Student-to-Student Learning: Youth-led Programs Impacting Engineering Education Globally

    Directory of Open Access Journals (Sweden)

    Julian O'Shea

    2011-07-01

    Full Text Available Around the globe, students and young engineers are playing an increasing role in the coordination and delivery of engineering education programs. Many youth-led initiatives are now conducted with students involved in all aspects of their creation, organisation and delivery. This trend presents an exciting opportunity for the education of engineering students, both those involved in delivery of the courses and for participants. This paper profiles four leading youth-led engineering education programs and analyses their structure and growth in recent years. Profiled are initiatives coordinated by Engineers Without Borders – Australia (EWB-A; the Board of European Students of Technology (BEST; the Electrical Engineering Students’ European Association (EESTEC; and the Student Platform for Engineering Education Development (SPEED. Each case study includes a brief history of the organisation, program overview, growth analysis and future projections. The common features amongst these programs were analysed, as were the aspects which made them distinct from traditional university offerings. Key findings about the initiatives include: an international focus; the mixture of formal learning and social aspects; an integral role of volunteers within the organisation; the use of residential programs; and the role of internal professional development of committee members and volunteers. Additionally, this paper outlines the benefits for universities and provides a guide for how engineering faculties can support and nurture these initiatives and effectively create partnerships.

  5. DESIGNING CLIENT OF ANDROID-BASED LED INTELLIGENT LIGHTING SYSTEM AND ITS IMPLEMENTATION%基于 Android 的 LED 智能照明系统客户端的设计与实现

    Institute of Scientific and Technical Information of China (English)

    胡艳蕊; 宋开新; 秦会斌; 张明准

    2016-01-01

    To get rid of the way of controlling home lighting with traditional mechanical switches and to make full use of the advantages of smart phones and other mobile equipment resources,we proposed the Android-based LED intelligent lighting systems,and designed and developed the Android-based client of LED intelligent lighting system.We used WiFi to control home lighting equipment,it can not only control the on and off,timing,dimming and colouring of individual light and lights group,but can also select and edit different lighting effects in scene patterns according to the needs of different environments,as well as can dynamically add new lights through code scanning. Moreover,in intelligent light control module we called the China Weather Network API interface and the phone built-in light sensor to automatically control the colour and brightness of the light,the function advertising has also been added to the client.We tested the client system and the lighting module in a wireless network environment,the feasibility and practicality of the LED intelligent lighting system client has been proven.%为了摆脱用传统机械式开关控制家居照明的方式,充分利用智能手机等移动设备资源,提出基于 Android 的 LED 智能照明系统,设计开发基于 Android 的 LED 智能照明系统客户端。利用 WiFi 控制家居照明设备,不仅可以控制单个灯和各组灯的开关、定时、调光和调色,而且可以根据对不同环境的需求在情景模式中选择和编辑不同的灯光效果,还可以通过扫码动态添加新灯等。并且在智能光控模块中调用了中国天气网 API 接口和手机自带的光线传感器来自动调节灯光的颜色和亮度,该客户端还增加了广告功能。把该客户端系统和灯具模块放在无线网络环境中进行测试,验证了该 LED 智能照明系统客户端的可行性和实用性。

  6. 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.

  7. Design of High Efficiency Illumination for LED Lighting

    Directory of Open Access Journals (Sweden)

    Yong-Nong Chang

    2013-01-01

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

  8. Peer-led small groups: Are we on the right track?

    Science.gov (United States)

    Moore, Fraser

    2017-10-01

    Peer tutor-led small group sessions are a valuable learning strategy but students may lack confidence in the absence of a content expert. This study examined whether faculty reinforcement of peer tutor-led small group content was beneficial. Two peer tutor-led small group sessions were compared with one faculty-led small group session using questionnaires sent to student participants and interviews with the peer tutors. One peer tutor-led session was followed by a lecture with revision of the small group content; after the second, students submitted a group report which was corrected and returned to them with comments. Student participants and peer tutors identified increased discussion and opportunity for personal reflection as major benefits of the peer tutor-led small group sessions, but students did express uncertainty about gaps in their learning following these sessions. Both methods of subsequent faculty reinforcement were perceived as valuable by student participants and peer tutors. Knowing in advance that the group report would be corrected reduced discussion in some groups, potentially negating one of the major benefits of the peer tutor-led sessions. Faculty reinforcement of peer-tutor led small group content benefits students but close attention should be paid to the method of reinforcement.

  9. BiliLED low cost neonatal phototherapy, from prototype to industry

    Energy Technology Data Exchange (ETDEWEB)

    Geido, Daniel; Failache, Horacio [Instituto de Fisica de la Facultad de Ingenieria - Universidad de la Republica, Montevideo (Uruguay); Simini, Franco [Nucleo de Ingenieria Biomedica de las Facultades de Medicina e Ingenieria (Uruguay); Hospital de ClInicas. Av Italia S/N. Piso 15 sala 2, 11600 Montevideo (Uruguay)

    2007-11-15

    BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14x14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described.

  10. BiliLED low cost neonatal phototherapy, from prototype to industry

    Science.gov (United States)

    Geido, Daniel; Failache, Horacio; Simini, Franco

    2007-11-01

    BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14×14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described.

  11. BiliLED low cost neonatal phototherapy, from prototype to industry

    International Nuclear Information System (INIS)

    Geido, Daniel; Failache, Horacio; Simini, Franco

    2007-01-01

    BiliLED is a phototherapy instrument designed to reduce bilirrubin blood rates in new born babies with jaundice. The light source is centred at 470 nm with a bandwidth of 35 nm and includes a matrix of 196 (14x14) InGaN LEDs. The optical elements are designed to maximize the light intensity useful for treatment, with a small number of LEDs in a compact and low cost unit. The optic array is such that every LED illuminates all the treatment area, which ensures redundancy and, thus, a high reliability not to be found in single-lamp instruments. Thermal dissipation and cost of BiliLED are both an order-of-magnitude smaller than conventional therapy lamps. BiliLED adjusts coetaneous irradiation with a feedback loop to compensate the loss or aging of LEDs achieving a calibrated light source for over a decade of use. A clinical trial in 20 hyperbilirrubinaemia patients shows 16% bilirrubin degradation within 24 hours of treatment, higher than most lamp phototherapy instruments. The steps from prototype to commercial model are described

  12. Design Secondary Optical System Applied in White-LED General Illumination

    International Nuclear Information System (INIS)

    Chen Chen; Zhang Xianhui

    2011-01-01

    As a new generation of light source, LED has many advantages that other light sources do not have. However, due to the nonuniform lighting of LED, secondary LED optical system design is particularly important. Freeform surface tailoring method, an important method of lighting design, establishes a light intensity change model after smooth surface refraction (reflection) of the light and simplifies the solution process for more complex issues of solution using the free surface tailoring method. Based on this method, secondary LED optical system is designed, and the light intensity distribution is simulated after LED light passes through the secondary optical system. The results show that the method has not only simplified the calculation process of the free surface tailoring method, but also the designed LED secondary optical system has achieved the purpose of uniform lighting to a certain degree.

  13. TRANSFORMATION OF TRADITION OF BARONG NGELAWANG IN TOURISM AREA OF UBUD, GIANYAR, BALI

    Directory of Open Access Journals (Sweden)

    I Nyoman Sukerna

    2016-02-01

    Full Text Available Globalization carries new values and touches all aspects of life, one of which is  the tradition of barong ngelawang. This present study is intended to discuss the pattern of transformation, ideology and meaning of the tradition of barong ngelawang in the tourism area of Ubud, Gianyar, Bali. The study views the tradition of barong ngelawang as a text of which the context, why and how it is performed should be understood. The theory of social practice, the theory of ideology, and the theory of semiotics were used to analyze the data. The descriptive and interpretative method was employed. The result of the study shows that the tradition of barong ngelawang in Ubud was transformed from being a scared performance into a secular performance, and from a secular performance into a sacred performance. The transformation also took place in the space dimension. The ideologies which led to the activity of barong ngelawang were the religious ideology and solidarity ideology. The secular activity of barong ngelawang was dominated by the ideology of creativity and the economic ideology. From the ideological context, the meanings which could be revealed from the activity of barong ngelawang were the religious meaning and artistic meaning. From the superstructure context, the meanings that could be revealed were the social stratification meaning, the job description meaning, and the educational meaning. From the infrastructure context, the meaning which could be revealed was the economic meaning.

  14. Construction of Tungsten Halogen, Pulsed LED, and Combined Tungsten Halogen-LED Solar Simulators for Solar Cell I-V Characterization and Electrical Parameters Determination

    Directory of Open Access Journals (Sweden)

    Anon Namin

    2012-01-01

    Full Text Available I-V characterization of solar cells is generally done under natural sunlight or solar simulators operating in either a continuous mode or a pulse mode. Simulators are classified on three features of irradiance, namely, spectral match with respect to air mass 1.5, spatial uniformity, and temporal stability. Commercial solar simulators use Xenon lamps and halogen lamps, whereas LED-based solar simulators are being developed. In this work, we build and test seven simulators for solar cell characterization, namely, one tungsten halogen simulator, four monochromatic (red, green, blue, and white LED simulators, one multicolor LED simulator, and one tungsten halogen-blue LED simulator. The seven simulators provide testing at nonstandard test condition. High irradiance from simulators is obtained by employing elevated supply voltage to tungsten halogen lamps and high pulsing voltages to LEDs. This new approach leads to higher irradiance not previously obtained from tungsten halogen lamps and LEDs. From I-V curves, electrical parameters of solar cell are made and corrected based on methods recommended in the IEC 60891 Standards. Corrected values obtained from non-STC measurements are in good agreement with those obtained from Class AAA solar simulator.

  15. LED based opto-wetting platforms for micromixing

    Science.gov (United States)

    Thomas, Tony; Narayanan Unni, Harikrishnan

    2018-02-01

    The digital microfluidics utilizes the gradient in wettability for droplet transportation. This paper reports a novel technique of LED induced wetting ( Opto-wetting) where a single low power LED (Light emitting diode) emitting light of wavelength 395nm peak with luminous intensity of 300mcd (milli candela) is used to move two droplets of 20μL each on a photo responsive substrate of azobenzene (C12H10N2) coated PDMS (Poly Dimethyl Siloxane) substrate. The PDMS substrate of size 5cmx2cmx0.5cm were modified by thin film coating of Azobenzene dissolved in olive oil solution. The LED was aligned vertically on the top of the substrate. The pulsed operation of LED induces a spatial gradient of surface energy due to the reversible process of photo isomerization of Azobenzene molecules coated on the surface. The Photo-isomerization changes the conformation of the molecules thereby changing its surface energy .The change in surface energy of the substrate induces a change in contact angle of the droplet which initiates its movement. Two water droplets each of 20μL were dispensed on the substrate using micro syringe. Two droplets which were initially at a few cm distance apart were gradually moved towards the focus of light and merged together. The urine droplets (20μL) were moved and mixed with the red dye reagent (20μL) by controlling the light intensity of the LED. This concept provides a cost effective technique of droplet manipulation in the Lab on a chip domain where various multiplexed operations on proteins and DNA droplets can be done for point of care diagnostics.

  16. The improvement of GaN-based LED grown on concave nano-pattern sapphire substrate with SiO2 blocking layer

    International Nuclear Information System (INIS)

    Lin, Jyun-Hao; Huang, Shyh-Jer; Su, Yan-Kuin; Huang, Kai-Wen

    2015-01-01

    Highlights: • Concave nano-patterned sapphire substrates with SiO 2 blocking layer. • The IQE is almost two times larger than that of conventional one. • The EQE was extremely enhanced more than 100%. - Abstract: In contrast to convex nano-pattern sapphire substrates (NPSS), which are frequently used to fabricate high-quality nitride-based light-emitting diodes (LEDs), concave NPSS have been paid relatively less attention. In this study, a concave NPSS was fabricated, and its nitride epitaxial growth process was evaluated in a step by step manner. A SiO 2 layer was used to avoid nucleation over the sidewall and bottom of the nano-patterns to reduce dislocation reformation. Traditional LED structures were grown on the NPSS layer to determine its influence on device performance. X-ray diffraction, etched pit density, inverse leakage current, and internal quantum efficiency (IQE) results showed that dislocations and non-radiative recombination centers are reduced by the NPSS constructed with a SiO 2 blocking layer. An IQE twice that on a planar substrate was also achieved; such a high IQE significantly enhanced the external quantum efficiency of the resultant device. Taken together, the results demonstrate that the SiO 2 blocking layer proposed in this work can enhance the performance of LEDs.

  17. 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

  18. On-off switching patterns for smart LED lighting

    NARCIS (Netherlands)

    Linnartz, J.P.M.G.; Schenk, T.C.W.; Feri, L.; Yang, Hongming; Tjalkens, T.J.; Willems, F.M.J.

    2009-01-01

    This paper formulates a new communication problem for smart LED lighting sys tems designed for light effect control. It introduces the key requirements imposed on the design of the LED driving sequences, which include multiple access, arbi trary duty cycle and no disturbance caused on the normal

  19. Flicker Reduction in LED-LCDs with Local Backlight

    DEFF Research Database (Denmark)

    Nadernejad, Ehsan; Mantel, Claire; Burini, Nino

    2013-01-01

    Local backlight dimming of LCD with LED backlight can reduce power consumption and improve quality of displayed images and videos. However, important variations of LED over time produce a visually annoying artifact called flickering. In this work, we propose a new algorithm to reduce flickering w...

  20. Signal processing for LED lighting systems : illumination rendering and sensing

    NARCIS (Netherlands)

    Yang, H.

    2010-01-01

    Solid state lighting, employing high brightness light emitting diodes (LEDs), is becoming increasingly widely used. The advantages of LEDs include high radiative efficiency, long lifetime, limited heat generation and superior tolerance to humidity. Another important advantage of LED lighting systems

  1. Meeting the challenges of developing LED-based projection displays

    Science.gov (United States)

    Geißler, Enrico

    2006-04-01

    The main challenge in developing a LED-based projection system is to meet the brightness requirements of the market. Therefore a balanced combination of optical, electrical and thermal parameters must be reached to achieve these performance and cost targets. This paper describes the system design methodology for a digital micromirror display (DMD) based optical engine using LEDs as the light source, starting at the basic physical and geometrical parameters of the DMD and other optical elements through characterization of the LEDs to optimizing the system performance by determining optimal driving conditions. LEDs have a luminous flux density which is just at the threshold of acceptance in projection systems and thus only a fully optimized optical system with a matched set of LEDs can be used. This work resulted in two projection engines, one for a compact pocket projector and the other for a rear projection television, both of which are currently in commercialization.

  2. LED-based UV source for monitoring spectroradiometer properties

    Science.gov (United States)

    Sildoja, Meelis-Mait; Nevas, Saulius; Kouremeti, Natalia; Gröbner, Julian; Pape, Sven; Pendsa, Stefan; Sperfeld, Peter; Kemus, Fabian

    2018-06-01

    A compact and stable UV monitoring source based on state-of-the-art commercially available ultraviolet light emitting diodes (UV-LEDs) has been developed. It is designed to trace the radiometric stability—both responsivity and wavelength scale—of array spectroradiometers measuring direct solar irradiance in the wavelength range between 300 nm and 400 nm. The spectral irradiance stability of the UV-LED-based light source observed in the laboratory after seasoning (burning-in) the individual LEDs was better than 0.3% over a 12 h period of continuous operation. The integral irradiance measurements of the source over a period of several months, where the UV-LED source was not operated continuously between the measurements, showed stability within 0.3%. In-field measurements of the source with an array spectroradiometer indicated the stability of the source to be within the standard uncertainty of the spectroradiometer calibration, which was within 1% to 2%.

  3. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products Part 2: LED Manufacturing and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Scholand, Michael; Dillon, Heather E.

    2012-05-01

    Part 2 of the project (this report) uses the conclusions from Part 1 as a point of departure to focus on two objectives: producing a more detailed and conservative assessment of the manufacturing process and providing a comparative LCA with other lighting products based on the improved manufacturing analysis and taking into consideration a wider range of environmental impacts. In this study, we first analyzed the manufacturing process for a white-light LED (based on a sapphire-substrate, blue-light, gallium-nitride LED pumping a yellow phosphor), to understand the impacts of the manufacturing process. We then conducted a comparative LCA, looking at the impacts associated with the Philips Master LEDbulb and comparing those to a CFL and an incandescent lamp. The comparison took into account the Philips Master LEDbulb as it is now in 2012 and then projected forward what it might be in 2017, accounting for some of the anticipated improvements in LED manufacturing, performance and driver electronics.

  4. 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.

  5. 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....

  6. Analysis of technology and seminar on economic trends about High-intensity LED

    International Nuclear Information System (INIS)

    2003-09-01

    This is divided into two parts. Contents of this report in the first part are technical trends on high-intensity LED which reports introduction of LED as compound semiconductor, white LED? patent issues, review on technology of High-intensity LED and Reliability of High-intensity LED. The second part deals with economic tends about High-intensity LED. This seminar was held to report analysis and economical trends about High-intensity LED by Korea Industrial Education Institute in 2003.

  7. Uniformity of LED light illumination in application to direct imaging lithography

    Science.gov (United States)

    Huang, Ting-Ming; Chang, Shenq-Tsong; Tsay, Ho-Lin; Hsu, Ming-Ying; Chen, Fong-Zhi

    2016-09-01

    Direct imaging has widely applied in lithography for a long time because of its simplicity and easy-maintenance. Although this method has limitation of lithography resolution, it is still adopted in industries. Uniformity of UV irradiance for a designed area is an important requirement. While mercury lamps were used as the light source in the early stage, LEDs have drawn a lot of attention for consideration from several aspects. Although LED has better and better performance, arrays of LEDs are required to obtain desired irradiance because of limitation of brightness for a single LED. Several effects are considered that affect the uniformity of UV irradiance such as alignment of optics, temperature of each LED, performance of each LED due to production uniformity, and pointing of LED module. Effects of these factors are considered to study the uniformity of LED Light Illumination. Numerical analysis is performed by assuming a serious of control factors to have a better understanding of each factor.

  8. A Novel Methodology for Measurements of an LED's Heat Dissipation Factor

    Science.gov (United States)

    Jou, R.-Y.; Haung, J.-H.

    2015-12-01

    Heat generation is an inevitable byproduct with high-power light-emitting diode (LED) lighting. The increase in junction temperature that accompanies the heat generation sharply degrades the optical output of the LED and has a significant negative influence on the reliability and durability of the LED. For these reasons, the heat dissipation factor, Kh, is an important factor in modeling and thermal design of LED installations. In this study, a methodology is proposed and experiments are conducted to determine LED heat dissipation factors. Experiments are conducted for two different brands of LED. The average heat dissipation factor of the Edixeon LED is 0.69, and is 0.60 for the OSRAM LED. By using the developed test method and comparing the results to the calculated luminous fluxes using theoretical equations, the interdependence of optical, electrical, and thermal powers can be predicted with a reasonable accuracy. The difference between the theoretical and experimental values is less than 9 %.

  9. Traditional and non-traditional educational outcomes : Trade-off or complementarity?

    NARCIS (Netherlands)

    van der Wal, Marieke; Waslander, Sietske

    2007-01-01

    Recently, schools have increasingly been charged with enhancing non-traditional academic competencies, in addition to traditional academic competencies. This article raises the question whether schools can implement these new educational goals in their curricula and simultaneously realise the

  10. Quick detection of traditional Chinese medicine ‘Atractylodis Macrocephalae Rhizoma’ pieces by surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Huang, Hao; Shi, Hong; Feng, Shangyuan; Lin, Juqiang; Chen, Weiwei; Yu, Yun; Lin, Duo; Xu, Qian; Chen, Rong

    2013-01-01

    A surface-enhanced Raman spectroscopy (SERS) method was developed for the analysis of traditional Chinese medicine ‘Atractylodis Macrocephalae Rhizoma’ pieces (AMRP) for the first time with the aim to develop a quick method for traditional Chinese medicine detection. Both Raman spectra and SERS spectra were obtained from AMRP, and tentative assignments of the Raman bands in the measured spectra suggested that only a few weak Raman peaks could be observed in the regular Raman spectra, while primary Raman peaks at around 536, 555, 619, 648, 691, 733, 790, 958, 1004, 1031, 1112, 1244, 1324, 1395, 1469, 1574 and 1632 cm-1 could be observed in the SERS spectra, with the strongest signals at 619, 733, 958, 1324, 1395 and 1469 cm-1. This was due to a strong interaction between the silver colloids and the AMRP, which led to an extraordinary enhancement in the intensity of the Raman scattering in AMRP. This exploratory study suggests the SERS technique has great potential for providing a novel non-destructive method for effectively and accurately detecting traditional Chinese medicine without complicated separation and extraction.

  11. 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

  12. Éalonnage de sources lumineuses de type LED

    DEFF Research Database (Denmark)

    Durix, Bastien; Quéau, Yvain; Lucas, Tom

    We describe three calibration methods of a LED (light-emitting diode), in order to apply photometric stereo to a scene illuminated by LEDs. The most accurate of these methods will allow us to obtain very realistic 3D models. Nevertheless, the scene must remain still during the whole shooting sequ...

  13. 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.

  14. Reliability test and failure analysis of high power LED packages

    International Nuclear Information System (INIS)

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

    2011-01-01

    A new type application specific light emitting diode (LED) package (ASLP) with freeform polycarbonate lens for street lighting is developed, whose manufacturing processes are compatible with a typical LED packaging process. The reliability test methods and failure criterions from different vendors are reviewed and compared. It is found that test methods and failure criterions are quite different. The rapid reliability assessment standards are urgently needed for the LED industry. 85 0 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. (semiconductor devices)

  15. Energy-Saving Tunnel Illumination System Based on LED's Intelligent Control

    International Nuclear Information System (INIS)

    Guo Shanshan; Wu Lan; Gu Hanting; Jiang Shuixiu

    2011-01-01

    At present there is a lot of electric energy wastage in tunnel illumination, whose design is based on the maximum brightness outside and the maximum vehicle speed all year round. LED's energy consumption is low, and the control of its brightness is simple and effective. It can be quickly adjusted between 0-100% of its maximum brightness, and will not affect the service life. Therefore, using LED as tunnel's illumination source, we can achieve a good energy saving effect. According to real-time data acquisition of vehicle speed, traffic flow and brightness outside the tunnel, the auto real-time control of tunnel illumination can be achieved. And the system regulated the LED luminance by means of combination of LED power module and intelligent control module. The tunnel information was detected by inspection equipments, which included luminometer, vehicle detector, and received by RTU(Remote Terminal Unit), then synchronously transmitted to PC. After data processing, RTU emitted the dimming signal to the LED driver to adjust the brightness of LED. Despite the relatively high cost of high-power LED lights, the enormous energy-saving effect and the well-behaved controllability is beyond compare to other lighting devices.

  16. Effects of LED or laser phototherapy on bone defects grafted with MTA and irradiated with laser or LED light: a comparative Raman spectroscopic study

    Science.gov (United States)

    Pinheiro, Antonio L. B.; Soares, Luiz G. P.; Barbosa, Artur Felipe S.; Silveira, Landulfo, Jr.

    2012-03-01

    We studied peaks of calcium hydroxyapatite - CHA on defects grafted with MTA, treated or not with Light Emitting Diode - LED or IR Laser. 54 rats were divided in 6 groups each subdivided into 3 subgroups (15,21,30d). LED (λ850 +/- 10nm) or IR Laser (λ850 nm) was applied over (LED) or in 4 points around the defect at 48 h intervals for 15 days. Raman readings were taken at the surface of the defect. The smaller overall intensity of the peak was found in Group MTA + Laser (1510.2 +/- 274.1) and the highest on Group LED (2322 +/- 715). There were no statistically significant differences between non-irradiated subjects on regards the CHA peaks. On the other hand, there were statistically significant differences between the Group Clot and LED, Clot and Laser, and Clot and MTA + Laser (p =0.01, p = 0.02, p = 0.003). There were no significant differences between Group MTA and MTA + LED (p=0.2) but significant differences were seen between Groups MTA and MTA + Laser (p=0.01). Significant differences were also observed between Groups LED and Laser (p <0.001) and between Groups MTA + LED and MTA + Laser (p=0.009). MTA, due to its characteristics, seemed to be directly affected by the light. However, the use of either phototherapy positively affected bone healing similarly as observed on different studies using other biomaterials. The overall analysis of our results indicated that the use of either light source resulted in a better, more advanced, and of quality bone repair.

  17. Understanding Interactive CD-ROM Storybooks and Their Functions in Reading Comprehension: A Critical Review

    Science.gov (United States)

    Ertem, Ihsan Seyit

    2011-01-01

    With dramatic changes and recent advances in multimedia, digital technologies through computers propose new ways for introducing kids to the literacy. Literacy educators have stated that traditional printed books are not sufficient and electronic books have the potential to change reading skills. As a valuable tool in educational settings new and…

  18. Traditional, complementary, and alternative medicine: Focusing on research into traditional Tibetan medicine in China.

    Science.gov (United States)

    Song, Peipei; Xia, Jufeng; Rezeng, Caidan; Tong, Li; Tang, Wei

    2016-07-19

    As a form of traditional, complementary, and alternative medicine (TCAM), traditional Tibetan medicine has developed into a mainstay of medical care in Tibet and has spread from there to China and then to the rest of the world. Thus far, research on traditional Tibetan medicine has focused on the study of the plant and animal sources of traditional medicines, study of the histology of those plants and animals, chemical analysis of traditional medicines, pharmacological study of those medicines, and evaluation of the clinical efficacy of those medicines. A number of papers on traditional Tibetan medicines have been published, providing some evidence of the efficacy of traditional Tibetan medicine. However, many traditional Tibetan medicines have unknown active ingredients, hampering the establishment of drug quality standards, the development of new medicines, commercial production of medicines, and market availability of those medicines. Traditional Tibetan medicine must take several steps to modernize and spread to the rest of the world: the pharmacodynamics of traditional Tibetan medicines need to be determined, the clinical efficacy of those medicines needs to be verified, criteria to evaluate the efficacy of those medicines need to be established in order to guide their clinical use, and efficacious medicines need to be acknowledged by the pharmaceutical market. The components of traditional Tibetan medicine should be studied, traditional Tibetan medicines should be screened for their active ingredients, and techniques should be devised to prepare and manufacture those medicines.

  19. Thermal Characterization and Lifetime Prediction of LED Boards for SSL Lamp

    Directory of Open Access Journals (Sweden)

    J. Formanek

    2013-04-01

    Full Text Available This work presents a detailed 3-D thermo-mechanical modelling of two LED board technologies to compare their performance. LED board are considered to be used in high power 800 lumen retrofit SSL (Solid State Lighting lamp. Thermal, mechanical and life time properties are evaluated by numerical modelling. Experimental results measured on fabricated LED board samples are compared to calculated data. Main role of LED board in SSL lamp is to transport heat from LED die to a heat sink and keep the thermal stresses in all layers as low as possible. The work focuses on improving of new LED board thermal management. Moreover, reliability and lifetime of LED board has been inspected by numerical calculation and validated by experiment. Thermally induced stress has been studied for wide temperature range that can affect the LED boards (-40 to +125°C. Numerical modelling of thermal performance, thermal stress distribution and lifetime has been carried out with ANSYS structural analysis where temperature dependent stress-strain material properties have been taken into account. The objective of this study is to improve not only the thermal performance of new LED board, but also identification of potential problems from mechanical fatigue point of view. Accelerated lifetime testing (e.g., mechanical is carried out in order to study the failure behaviour of current and newly developed LED board.

  20. Aerial LED signage by use of crossed-mirror array

    Science.gov (United States)

    Yamamoto, Hirotsugu; Kujime, Ryousuke; Bando, Hiroki; Suyama, Shiro

    2013-03-01

    3D representation of digital signage improves its significance and rapid notification of important points. Real 3D display techniques such as volumetric 3D displays are effective for use of 3D for public signs because it provides not only binocular disparity but also motion parallax and other cues, which will give 3D impression even people with abnormal binocular vision. Our goal is to realize aerial 3D LED signs. We have specially designed and fabricated a reflective optical device to form an aerial image of LEDs with a wide field angle. The developed reflective optical device composed of crossed-mirror array (CMA). CMA contains dihedral corner reflectors at each aperture. After double reflection, light rays emitted from an LED will converge into the corresponding image point. The depth between LED lamps is represented in the same depth in the floating 3D image. Floating image of LEDs was formed in wide range of incident angle with a peak reflectance at 35 deg. The image size of focused beam (point spread function) agreed to the apparent aperture size.

  1. "Light-box" accelerated growth of poinsettias: LED-only illumination

    Science.gov (United States)

    Weerasuriya, Charitha; Detez, Stewart; Hock Ng, Soon; Hughes, Andrew; Callaway, Michael; Harrison, Iain; Katkus, Tomas; Juodkazis, Saulius

    2018-01-01

    For the current commercialized agricultural industry which requires a reduced product lead time to customer and supply all year round, an artificial light emitting diodes (LEDs)-based illumination has high potential due to high efficiency of electrical-to-light conversion. The main advantage of the deployed Red Green Blue Amber LED lighting system is colour mixing capability, which means ability to generate all the colours in the spectrum by using three or four primary colours LEDs. The accelerated plant growth was carried out in a "light-box" which was made to generate an artificial day/night cycle by moving the colour mixing ratio along the colour temperature curve of the chromaticity diagram. The control group of plants form the same initial batch was grown on the same shelf in a greenhouse at the same conditions with addition of artificial illumination by incandescent lamps for few hours. Costs and efficiency projections of LED lamps for horticultural applications is discussed together with required capital investment. The total cost of the "light-box" including LED lamps and electronics was 850 AUD.

  2. Issues and solutions: opportunities for European LED manufacturers

    Science.gov (United States)

    Pearsall, T. P.

    2007-09-01

    Marketing studies by EPIC show significant revenue opportunities by 2012 for UHB-LEDs in the automotive, LCD backlighting, and architectural lighting sectors. The goal of this workshop on manufacturing issues is to consider five key issues for UHB-LED manufacturing and to propose solutions that will pave the way to full exploitation of the opportunities.

  3. Solution of multi-element LED light sources development automation problem

    Science.gov (United States)

    Chertov, Aleksandr N.; Gorbunova, Elena V.; Korotaev, Valery V.; Peretyagin, Vladimir S.

    2014-09-01

    The intensive development of LED technologies resulted in the creation of multicomponent light sources in the form of controlled illumination devices based on usage of mentioned LED technologies. These light sources are used in different areas of production (for example, in the food industry for sorting products or in the textile industry for quality control, etc.). The use of LED lighting products in the devices used in specialized lighting, became possible due to wide range of colors of light, LED structures (which determines the direction of radiation, the spatial distribution and intensity of the radiation, electrical, heat, power and other characteristics), and of course, the possibility of obtaining any shade in a wide dynamic range of brightness values. LED-based lighting devices are notable for the diversity of parameters and characteristics, such as color radiation, location and number of emitters, etc. Although LED technologies have several advantages, however, they require more attention if you need to ensure a certain character of illumination distribution and/or distribution of the color picture at a predetermined distance (for example, at flat surface, work zone, area of analysis or observation). This paper presents software designed for the development of the multicomponent LED light sources. The possibility of obtaining the desired color and energy distribution at the zone of analysis by specifying the spatial parameters of the created multicomponent light source and using of real power, spectral and color parameters and characteristics of the LEDs is shown as well.

  4. Application of Wireless Intelligent Control System for HPS Lamps and LEDs Combined Illumination in Road Tunnel

    Science.gov (United States)

    Lai, Jinxing; Qiu, Junling; Chen, Jianxun; Wang, Yaqiong; Fan, Haobo

    2014-01-01

    Because of the particularity of the environment in the tunnel, the rational tunnel illumination system should be developed, so as to optimize the tunnel environment. Considering the high cost of traditional tunnel illumination system with high-pressure sodium (HPS) lamps as well as the effect of a single light source on tunnel entrance, the energy-saving illumination system with HPS lamps and LEDs combined illumination in road tunnel, which could make full use of these two kinds of lamps, was proposed. The wireless intelligent control system based on HPS lamps and LEDs combined illumination and microcontrol unit (MCU) Si1000 wireless communication technology was designed. And the remote monitoring, wireless communication, and PWM dimming module of this system were designed emphatically. Intensity detector and vehicle flow detector can be configured in wireless intelligent control system, which gather the information to the master control unit, and then the information is sent to the monitoring center through the Ethernet. The control strategies are got by the monitoring center according to the calculated results, and the control unit wirelessly sends parameters to lamps, which adjust the luminance of each segment of the tunnel and realize the wireless intelligent control of combined illumination in road tunnel. PMID:25587266

  5. 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.

  6. Smart LED allocation scheme for efficient multiuser visible light communication networks.

    Science.gov (United States)

    Sewaiwar, Atul; Tiwari, Samrat Vikramaditya; Chung, Yeon Ho

    2015-05-18

    In a multiuser bidirectional visible light communication (VLC), a large number of LEDs or an LED array needs to be allocated in an efficient manner to ensure sustainable data rate and link quality. Moreover, in order to support an increasing or decreasing number of users in the network, the LED allocation is required to be performed dynamically. In this paper, a novel smart LED allocation scheme for efficient multiuser VLC networks is presented. The proposed scheme allocates RGB LEDs to multiple users in a dynamic and efficient fashion, while satisfying illumination requirements in an indoor environment. The smart LED array comprised of RGB LEDs is divided into sectors according to the location of the users. The allocated sectors then provide optical power concentration toward the users for efficient and reliable data transmission. An algorithm for the dynamic allocation of the LEDs is also presented. To verify its effective resource allocation feature of the proposed scheme, simulations were performed. It is found that the proposed smart LED allocation scheme provides the effect of optical beamforming toward individual users, thereby increasing the collective power concentration of the optical signals on the desirable users and resulting in significantly increased data rate, while ensuring sufficient illumination in a multiuser VLC environment.

  7. [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.

  8. Dental Hygienist-Led Chronic Disease Management System to Control Early Childhood Caries.

    Science.gov (United States)

    Ng, Man Wai; Fida, Zameera

    2016-06-01

    Management of the complex chronic disease of early childhood caries requires a system of coordinated health care interventions which can be led by a dental hygienist and where patient self-care efforts are paramount. Even after receiving costly surgical treatment under general anesthesia in the operating room, many children develop new and recurrent caries after only 6-12 months, a sequela that can be prevented. This article describes the chronic disease management (CDM) of dental caries, a science-based approach that can prevent and control caries. In this article, we (1) introduce the concept of CDM of dental caries, (2) provide evidence that CDM improves oral health outcomes, and (3) propose a dental hygienist-led team-based oral health care approach to CDM. Although we will be describing the CDM approach for early childhood caries, CDM of caries is applicable in children, adolescents, and adults. Early childhood caries disease control requires meaningful engagement of patients and parents by the oral health care team to assist them with making behavioral changes in the unique context of their families and communities. The traditional dentist/hygienist/assistant model needs to evolve to a collaborative partnership between care providers and patients/families. This partnership will be focused on systematic risk assessment and behaviorally based management of the disease itself, with sensitivity toward the familial environment. Early pilot study results demonstrate reductions in the rates of new caries, dental pain, and referral to the operating room compared with baseline rates. Dental hygienists are the appropriate team members to lead this approach because of their expertise in behavior change and prevention. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Enhancing the Appreciation of Traditional Chinese Painting Using Interactive Technology

    Directory of Open Access Journals (Sweden)

    Shichao Zhao

    2018-04-01

    Full Text Available In this paper, we present a two-part study. The first part was a cultural appreciation study. Through this study, we explored the specific approach of cross-cultural aesthetic appreciation and mapped out the potential insights for a prototype design. In the second part, we carried out a design-led study. We designed a tablet application and conducted focus group studies to explore the interactive technology that assists in the support of cross-cultural audiences’ aesthetic appreciation and engagement of traditional Chinese painting. Based on these findings, we went on to further explore an approach of interactive engagement which is specific to supporting cross-cultural appreciation, while also reflecting upon the interactive design suggestions for the development of aesthetic appreciation to offer various transferable insights to the Human–Computer Interaction (HCI community.

  10. Understanding and controlling chromaticity shift in LED devices

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Lynn; Mills, Karmann; Lamvik, Michael; Perkins, Curtis; Bobashev, Georgiy; Young, Joseph; Yaga, Robert; Johnson, Cortina

    2017-05-30

    Chromaticity shift in light-emitting diode (LED) devices arises from multiple mechanisms, and at least five different chromaticity shift modes (CSMs) have been identified to date. This paper focuses on the impacts of irreversible phosphor degradation as a cause of chromaticity shifts in LED devices. The nitride phosphors used to produce warm white LEDs are especially vulnerable to degradation due to thermal and chemical effects such as reactions with oxygen and water. As a result, LED devices utilizing these phosphors were found to undergo either a green shift or, less commonly, a red shift depending on the phosphor mix in the LED devices. These types of chromaticity shifts are classified as CSM-2 (green shift) and CSM-5 (red shift). This paper provides an overview of the kinetic processes responsible for green and red chromaticity shifts along with examples from accelerated stress testing of 6” downlights. Both CSMs appear to proceed through analogous mechanisms that are initiated at the surface of the phosphor. A green shift is produced by the surface oxidation of the nitride phosphor that changes the emission profile to lower wavelengths. As the surface oxidation reaction proceeds, reactant limitations slow the rate and bulk oxidation processes become more prevalent. We found that a red chromaticity shift arises from quenching of the green phosphor, also possibly due to surface reactions of oxygen, which shift the emission chromaticity in the red direction. In conclusion, we discuss the implications of these findings on projecting chromaticity.

  11. LED lighting and the Next Generation of Greenhouse for Tomatoes. Proof of Principle; LED belichting en Het Nieuwe Telen bij tomaat. Proof of Principle

    Energy Technology Data Exchange (ETDEWEB)

    Dueck, T.; Janse, J.; Eveleens, B. [Wageningen UR Glastuinbouw, Wageningen (Netherlands); Nieboer, S.; Valstar, W.; Grootscholten, M. [GreenQ Improvement Centre, Bleiswijk (Netherlands)

    2012-08-15

    In this Proof of Principle project a tomato crop was grown under artificial lighting with the aim of 30% energy saving at the same level of production. Tomatoes (cultivar Komeett) were illuminated with 110 {mu}mol m{sup -2} s{sup -1} HPS (High Pressure Sodium) above the crop and 85 {mu}mol m{sup -2} s{sup -1} LED interlighting. The LEDs hung in 2 rows, approximately 40 cm above the lower leaves and the second strand at 40 or 70 cm above that. There were two types of LEDs used: production LEDs (light efficiency 1.6 {mu}mol m{sup -2} s{sup -1}, 87% red/13% blue) and inter-lighting LEDs (light efficiency 1.9 {mu}mol m{sup -2} s{sup -1}, 95% red/5% blue), with the same light intensity. At the start, the crop was given as much light as it could handle, and because the crop developed so well, the stem density was increased relatively early. This resulted in high fruit load, while insufficient light was available to compensate for the low levels of sunlight in the winter. In the 192 cm row spacing system the plants were too close to each other. Additional problems occurred with trace elements, lesser bumble bee activity, and a moist greenhouse climate which weakened the crop in the winter. Thus Botrytis occurred on the leaves and stems. The crop struggled with its recovery until early spring with more sunlight. Compared to a reference crop with 79 kg m{sup -2} tomatoes, 75 kg m{sup -2} were produced under-production LEDs, and 80 kg m{sup -2} under the interlighting LEDs, mainly because latter LEDs were used longer during the summer. 30% of the energy for dehumidification and heat energy, and 27% of the electricity was saved, relative to the reference crop. Thus it appears possible to save 30% energy with a near identical production [Dutch] In dit Proof of Principle project is een belichte tomatenteelt geteeld met als doel 30% energiebesparing bij een gelijke productie. Tomaten van het ras Komeett werden belicht met 110 {mu}mol m{sup -2} s{sup -1} SON-T belichting boven

  12. 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.

  13. Iluminación LED. Un arma de doble filo

    OpenAIRE

    Sánchez de Miguel, Alejandro

    2004-01-01

    La iluminación LED es el futuro de la iluminación. Sin embargo, como toda tecnología, puede usarse de manera correcta o incorrecta. En el caso de los LED, el abaratamiento de la producción de luz podría provocar un aumento descontrolado de la Contaminación lumínica. Por otro, el uso correcto de los LED podría ser la solución al mismo mal por su capacidad de encendido casi instantáneo.

  14. The Effects of Brain Gym® Activities and Traditional Teaching Strategies on Students' Performance in Comprehension in a 4th Grade Classroom

    Science.gov (United States)

    Kariuki, Patrick N.; Kent, Holly D.

    2014-01-01

    The purpose of this study was to examine the difference between students' scores in comprehension (English Language Arts) tests when they are led in Brain Gym® activities before class instruction and when they are taught using traditional teaching strategies. The sample for this study consisted of 11 males and 9 females. Data were collected by…

  15. Progress and prospects of GaN-based LEDs using nanostructures

    Science.gov (United States)

    Zhao, Li-Xia; Yu, Zhi-Guo; Sun, Bo; Zhu, Shi-Chao; An, Ping-Bo; Yang, Chao; Liu, Lei; Wang, Jun-Xi; Li, Jin-Min

    2015-06-01

    Progress with GaN-based light emitting diodes (LEDs) that incorporate nanostructures is reviewed, especially the recent achievements in our research group. Nano-patterned sapphire substrates have been used to grow an AlN template layer for deep-ultraviolet (DUV) LEDs. One efficient surface nano-texturing technology, hemisphere-cones-hybrid nanostructures, was employed to enhance the extraction efficiency of InGaN flip-chip LEDs. Hexagonal nanopyramid GaN-based LEDs have been fabricated and show electrically driven color modification and phosphor-free white light emission because of the linearly increased quantum well width and indium incorporation from the shell to the core. Based on the nanostructures, we have also fabricated surface plasmon-enhanced nanoporous GaN-based green LEDs using AAO membrane as a mask. Benefitting from the strong lateral SP coupling as well as good electrical protection by a passivation layer, the EL intensity of an SP-enhanced nanoporous LED was significantly enhanced by 380%. Furthermore, nanostructures have been used for the growth of GaN LEDs on amorphous substrates, the fabrication of stretchable LEDs, and for increasing the 3-dB modulation bandwidth for visible light communication. Project supported by the National Natural Science Foundation of China (Grant No. 61334009), the National High Technology Research and Development Program of China (Grant Nos. 2015AA03A101 and 2014BAK02B08), China International Science and Technology Cooperation Program (Grant No. 2014DFG62280), the “Import Outstanding Technical Talent Plan” and “Youth Innovation Promotion Association Program” of the Chinese Academy of Sciences.

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

    Science.gov (United States)

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

    2015-09-01

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

  17. Improving Low-Income Preschoolers’ Theory of Mind: A Training Study

    Science.gov (United States)

    Tompkins, Virginia

    2015-01-01

    This study examined the efficacy of training theory of mind via storybook interactions focused on characters' mental states (i.e., beliefs and emotions) in a sample of 73 low-income preschoolers, and determined if training transferred to social competence. Children in the experimental group participated in experimenter-led book interactions in which characters' false beliefs and emotions were discussed. Children in the first control group were read the same stories, but without the embedded discussions; children in the second control group were not read books. Children's false belief understanding, emotion understanding, and social competence were assessed at pretest, an immediate posttest, and a delayed posttest two months later. Children in the experimental group outperformed both controls on false belief understanding, but not emotion understanding or social competence, at both posttests. PMID:26294810

  18. Response of Eustoma Leaf Phenotype and Photosynthetic Performance to LED Light Quality

    Directory of Open Access Journals (Sweden)

    Md Zohurul Kadir Roni

    2017-10-01

    Full Text Available In a controlled environment, light from light-emitting diodes (LEDs has been associated with affecting the leaf characteristics of Eustoma. LEDs help plant growth and development, yet little is known about photosynthetic performance and related anatomical features in the early growth stage of Eustoma leaves. In this study, we examined the effects of blue (B, red (R, and white (W LEDs on the photosynthetic performance of Eustoma leaves, as well as leaf morphology and anatomy including epidermal layer thickness, palisade cells, and stomatal characteristics. Leaves grown under B LEDs were thicker and had a higher chlorophyll content than those grown under the R and W LEDs. Leaves under B LEDs had greater net photosynthetic rates (A, stomatal conductance (gs, and transpiration rates (E, especially at a higher photon flux density (PPFD, that resulted in a decrease in the intercellular CO2 concentration (Ci, than leaves under the W and R LEDs. B LEDs resulted in greater abaxial epidermal layer thickness and palisade cell length and width than the R and W LED treatments. The palisade cells also developed a more cylindrical shape in response to the B LEDs. B LED leaves also showed greater guard cell length, breadth, and area, and stomatal density, than W or R LEDs, which may contribute to increased A, gs and E at higher PPFDs.

  19. 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.

  20. Multifaceted Pharmacist-led Interventions in the Hospital Setting

    DEFF Research Database (Denmark)

    Skjøt-Arkil, Helene; Olesen, Carina Lundby; Kjeldsen, Lene Juel

    2018-01-01

    Clinical pharmacy services often comprise complex interventions. In this MiniReview, we conducted a systematic review aiming to evaluate the impact of multifaceted pharmacist-led interventions in a hospital setting. We searched MEDLINE, Embase, Cochrane Library and CINAHL for peer-reviewed articles...... published from 2006 to 1 March 2018. Controlled trials concerning hospitalized patients in any setting receiving patient-related multifaceted pharmacist-led interventions were considered. All types of outcomes were accepted. Inclusion and data extraction was performed. Study characteristics were collected......) showed no significant results. This rMiniReview indicates that multifaceted pharmacist-led interventions in a hospital setting may improve the quality of medication use, reduce hospital visits and length of stay, while no effect was seen on mortality, patient-reported outcomes and cost...

  1. Colorimetry and efficiency of white LEDs: Spectral width dependence

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Elaine; Edwards, Paul R.; Martin, Robert W. [Department of Physics, SUPA, Strathclyde University, Glasgow (United Kingdom)

    2012-03-15

    The potential colour rendering capability and efficiency of white LEDs constructed by a combination of individual red, green and blue (RGB) LEDs are analysed. The conventional measurement of colour rendering quality, the colour rendering index (CRI), is used as well as a recently proposed colour quality scale (CQS), designed to overcome some of the limitations of CRI when narrow-band emitters are being studied. The colour rendering performance is maximised by variation of the peak emission wavelength and relative intensity of the component LEDs, with the constraint that the spectral widths follow those measured in actual devices. The highest CRI achieved is 89.5, corresponding to a CQS value of 79, colour temperature of 3800 K and a luminous efficacy of radiation (LER) of 365 lm/W. By allowing the spectral width of the green LED to vary the CRI can be raised to 90.9, giving values of 82.5 and 370 lm/W for the CQS and LER, respectively. The significance of these values are discussed in terms of optimising the possible performance of RGB LEDs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Testing Algorithmic Skills in Traditional and Non-Traditional Programming Environments

    Science.gov (United States)

    Csernoch, Mária; Biró, Piroska; Máth, János; Abari, Kálmán

    2015-01-01

    The Testing Algorithmic and Application Skills (TAaAS) project was launched in the 2011/2012 academic year to test first year students of Informatics, focusing on their algorithmic skills in traditional and non-traditional programming environments, and on the transference of their knowledge of Informatics from secondary to tertiary education. The…

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

    Science.gov (United States)

    Ali, Ramy E.; Elgala, Hany

    2016-09-01

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

  4. Liquid cooling applications on automotive exterior LED lighting

    Science.gov (United States)

    Aktaş, Mehmet; Şenyüz, Tunç; Şenyıldız, Teoman; Kılıç, Muhsin

    2018-02-01

    In this study cooling of a LED unit with heatsink and liquid cooling block which is used in automotive head lamp applications has been investigated numerically and experimentally. Junction temperature of a LED which is cooled with heatsink and liquid cooling block obtained in the experiment. 23°C is used both in the simulation and the experiment phase. Liquid cooling block material is choosed aluminium (Al) and polyamide. All tests and simulation are performed with three different flow rate. Temperature distribution of the designed product is investigated by doing the numerical simulations with a commercially software. In the simulations, fluid flow is assumed to be steady, incompressible and laminar and 3 dimensional (3D) Navier-Stokes equations are used. According to the calculations it is obtained that junction temperature is higher in the heatsink design compared to block cooled one. By changing the block material, it is desired to investigate the variation on the LED junction temperature. It is found that more efficient cooling can be obtained in block cooling by using less volume and weight. With block cooling lifetime of LED can be increased and flux loss can be decreased with the result of decreased junction temperature.

  5. Improved power quality based high brightness LED lamp driver

    African Journals Online (AJOL)

    user

    consists of a PFC Cuk DC-DC converter which operates in continuous conduction mode (CCM) to improve the ... In proposed LED driver as shown in Figure 1, a Cuk buck boost AC-DC converter ... Design and Analysis of Proposed LED Driver.

  6. LED licht van de toekomst

    NARCIS (Netherlands)

    Zeiler, W.

    2009-01-01

    De gloeilamp is verleden tijd, na ongeveer 125 jaar na de ontdekking door Thomas Edison valt langzaam maar zeker binnen een decennium het doek. Australië heeft de klassieke gloeilamp al in de ban gedaan en vele landen volgen deze trend. De rol van de klassieke gloeilamp wordt overgenomen door LED.

  7. Optimal colour quality of LED clusters based on memory colours.

    Science.gov (United States)

    Smet, Kevin; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Hanselaer, Peter

    2011-03-28

    The spectral power distributions of tri- and tetrachromatic clusters of Light-Emitting-Diodes, composed of simulated and commercially available LEDs, were optimized with a genetic algorithm to maximize the luminous efficacy of radiation and the colour quality as assessed by the memory colour quality metric developed by the authors. The trade-off of the colour quality as assessed by the memory colour metric and the luminous efficacy of radiation was investigated by calculating the Pareto optimal front using the NSGA-II genetic algorithm. Optimal peak wavelengths and spectral widths of the LEDs were derived, and over half of them were found to be close to Thornton's prime colours. The Pareto optimal fronts of real LED clusters were always found to be smaller than those of the simulated clusters. The effect of binning on designing a real LED cluster was investigated and was found to be quite large. Finally, a real LED cluster of commercially available AlGaInP, InGaN and phosphor white LEDs was optimized to obtain a higher score on memory colour quality scale than its corresponding CIE reference illuminant.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-16

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

  9. Private Enterprise-Led Economic Development in Sub-Saharan Africa

    DEFF Research Database (Denmark)

    Kuada, John Ernest

    Private Enterprise-Led Development in Sub-Saharan Africa provides a novel theoretical and conceptual model to guide research into Africa's economic development. It endorses the view that private enterprise-led growth will help reduce poverty since it strengthens individuals' capacity to care...

  10. Solution processable inverted structure ZnO-organic hybrid heterojuction white LEDs

    Science.gov (United States)

    Bano, N.; Hussain, I.; Soomro, M. Y.; EL-Naggar, A. M.; Albassam, A. A.

    2018-05-01

    Improving luminance efficiency and colour purity are the most important challenges for zinc oxide (ZnO)-organic hybrid heterojunction light emitting diodes (LEDs), affecting their large area applications. If ZnO-organic hybrid heterojunction white LEDs are fabricated by a hydrothermal method, it is difficult to obtain pure and stable blue emission from PFO due to the presence of an undesirable green emission. In this paper, we present an inverted-structure ZnO-organic hybrid heterojunction LED to avoid green emission from PFO, which mainly originates during device processing. With this configuration, each ZnO nanorod (NR) forms a discrete p-n junction; therefore, large-area white LEDs can be designed without compromising the junction area. The configuration used for this novel structure is glass/ZnO NRs/PFO/PEDOT:PSS/L-ITO, which enables the development of efficient, large-area and low-cost hybrid heterojunction LEDs. Inverted-structure ZnO-organic hybrid heterojunction white LEDs offer several improvements in terms of brightness, size, colour, external quantum efficiency and a wider applicability as compared to normal architecture LEDs.

  11. Financial services employees' experience of peer-led and clinician-led critical incident stress debriefing following armed robberies.

    Science.gov (United States)

    Simms-Ellis, R; Madill, A

    2001-01-01

    This study investigates financial services employees' experience of critical incident stress debriefing (CISD) and their views about peers and clinicians as facilitators. Semi-structured interview accounts of four participants who had experienced both peer-led and clinician-led CISD were analyzed using grounded theory. A core category, ambivalence, permeated each interview and divided into two poles: pathologizing and normalizing. The most frequently occurring sub-category was a dislike of professionalism. Participants preferred the peer debriefer who was perceived to have more personal involvement and with whom they felt more empowered and understood. The findings suggest that the status of the debriefer as 'peer' or 'clinician' may be a crucial variable in the effectiveness of CISD and should be considered when reviewing the outcome literature.

  12. Traditional timber frames

    NARCIS (Netherlands)

    Jorissen, A.J.M.; Hamer, den J.; Leijten, A.J.M.; Salenikovich, A.

    2014-01-01

    Due to new possibilities traditional timber framing has become increasingly popular since the beginning of the 21e century. Although traditional timber framing has been used for centuries, the expected mechanical behaviour is not dealt with in great detail in building codes, guidelines or text

  13. Building an intelligence-led security program

    CERN Document Server

    Liska, Allan

    2014-01-01

    As recently as five years ago, securing a network meant putting in a firewall, intrusion detection system, and installing antivirus software on the desktop. Unfortunately, attackers have grown more nimble and effective, meaning that traditional security programs are no longer effective. Today's effective cyber security programs take these best practices and overlay them with intelligence. Adding cyber threat intelligence can help security teams uncover events not detected by traditional security platforms and correlate seemingly disparate events across the network. Properly-implemented inte

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

    NARCIS (Netherlands)

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

    2017-01-01

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

  15. The ethics of improving African traditional medical practice: scientific or African traditional research methods?

    Science.gov (United States)

    Nyika, Aceme

    2009-11-01

    The disease burden in Africa, which is relatively very large compared with developed countries, has been attributed to various factors that include poverty, food shortages, inadequate access to health care and unaffordability of Western medicines to the majority of African populations. Although for 'old diseases' knowledge about the right African traditional medicines to treat or cure the diseases has been passed from generation to generation, knowledge about traditional medicines to treat newly emerging diseases has to be generated in one way or another. In addition, the existing traditional medicines have to be continuously improved, which is also the case with Western scientific medicines. Whereas one school of thought supports the idea of improving medicines, be they traditional or Western, through scientific research, an opposing school of thought argues that subjecting African traditional medicines to scientific research would be tantamount to some form of colonization and imperialism. This paper argues that continuing to use African traditional medicines for old and new diseases without making concerted efforts to improve their efficacy and safety is unethical since the disease burden affecting Africa may continue to rise in spite of the availability and accessibility of the traditional medicines. Most importantly, the paper commends efforts being made in some African countries to improve African traditional medicine through a combination of different mechanisms that include the controversial approach of scientific research on traditional medicines.

  16. 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.

  17. Freeform lens design for LED collimating illumination.

    Science.gov (United States)

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

    2012-05-07

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

  18. Forward Conduction Mode Controlled Piezoelectric Transformer-Based PFC LED Drive

    DEFF Research Database (Denmark)

    Roedgaard, M. S.; Weirich, M.; Andersen, M. A. E.

    2013-01-01

    Light-emitting diode (LED) illumination is getting more and more common; as LED's performance is rising, the price is falling and is getting competitive. Some of the challenges of ac mains supplied illumination are the requirement of power factor correction (PFC) and the competitiveness of a low...... priced market. In this paper, a new forward conduction mode (FCM) control method for piezoelectric transformer (PT)-based power converters is proposed. A PT-based LED drive facilitating passive PFC is developed, utilizing and validating the FCM control method. The drive utilizes an inductorless half...... LED drive has been developed, supplied from 230-V 50-Hz ac mains, achieving a power factor of 0.96....

  19. Making Plans against All Odds : LED in Small Towns of the Free ...

    African Journals Online (AJOL)

    Since the transition to democracy, there has been an increasing emphasis on local economic development (LED) in South Africa. The LED efforts in three small municipalities of the Free State Province are examined against the international framework for. LED planning and implementation. Often, LED is limited to ...

  20. Effect of Led Lighting Colors for Laying Japanese Quails

    Directory of Open Access Journals (Sweden)

    KC Nunes

    Full Text Available ABSTRACT Time of exposure and light intensity rearing house may affect the performance and egg quality of laying quails. This research aimed at evaluating the live performance, egg quality, biometry of the reproductive system, and the gastrointestinal tract of Japanese quails (Coturnix coturnix japonica exposed to artificial light-emitting diodes (LED of different colors in comparison with fluorescent lamps. A total of 240 Japanese quails were distributed in completely randomized experimental design with four treatments (fluorescent lamp, and green, red, or blue LED lamps with six replicates of 10 birds each. Average egg weight and eggshell thickness were different (p0.05. The oviduct of 64-d-old hens exposed to green LED lighting was shorter (p<0.05 than those exposed to the fluorescent lamp. Red LED can be used to replace the fluorescent lamps, as they promote the same live performance, egg quality, and morphological development of the reproductive tract of laying Japanese quails.

  1. Quick detection of traditional Chinese medicine ‘Atractylodis Macrocephalae Rhizoma’ pieces by surface-enhanced Raman spectroscopy

    International Nuclear Information System (INIS)

    Huang, Hao; Shi, Hong; Chen, Weiwei; Yu, Yun; Lin, Duo; Xu, Qian; Feng, Shangyuan; Lin, Juqiang; Chen, Rong

    2013-01-01

    A surface-enhanced Raman spectroscopy (SERS) method was developed for the analysis of traditional Chinese medicine ‘Atractylodis Macrocephalae Rhizoma’ pieces (AMRP) for the first time with the aim to develop a quick method for traditional Chinese medicine detection. Both Raman spectra and SERS spectra were obtained from AMRP, and tentative assignments of the Raman bands in the measured spectra suggested that only a few weak Raman peaks could be observed in the regular Raman spectra, while primary Raman peaks at around 536, 555, 619, 648, 691, 733, 790, 958, 1004, 1031, 1112, 1244, 1324, 1395, 1469, 1574 and 1632 cm −1 could be observed in the SERS spectra, with the strongest signals at 619, 733, 958, 1324, 1395 and 1469 cm −1 . This was due to a strong interaction between the silver colloids and the AMRP, which led to an extraordinary enhancement in the intensity of the Raman scattering in AMRP. This exploratory study suggests the SERS technique has great potential for providing a novel non-destructive method for effectively and accurately detecting traditional Chinese medicine without complicated separation and extraction. (paper)

  2. 130 LPW 1000 Lm Warm White LED for Illumination

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-21

    An illumination-grade warm-white LED, having correlated color temperature (CCT) between 2700 and 3500 K and capable of producing 1000 lm output at over 130 lm/W at room temperature, has been developed in this program. The high-power warm-white LED is an ideal source for use in indoor and outdoor lighting applications. Over the two year period, we have made the following accomplishments: • Developed a low-cost high-power white LED package and commercialized a series of products with CCT ranging from 2700 to 5700 K under the product name LUXEON M; • Demonstrated a record efficacy of 124.8 lm/W at a flux of 1023 lm, CCT of 3435 K and color rendering index (CRI) over 80 at room temperature in the productized package; • Demonstrated a record efficacy of 133.1 lm/W at a flux of 1015 lm, CCT of 3475 K and CRI over 80 at room temperature in an R&D package. The new high-power LED package is a die-on-ceramic surface mountable LED package. It has four 2 mm2 InGaN pump dice, flip-chip attached to a ceramic submount in a 2x2 array configuration. The submount design utilizes a design approach that combines a high-thermal- conductivity ceramic core for die attach and a low-cost and low-thermal-conductivity ceramic frame for mechanical support and as optical lens carrier. The LED package has a thermal resistance of less than 1.25 K/W. The white LED fabrication also adopts a new batch level (instead of die-by-die) phosphor deposition process with precision layer thickness and composition control, which provides not only tight color control, but also low cost. The efficacy performance goal was achieved through the progress in following key areas: (1) high-efficiency royal blue pump LED development through active region design and epitaxial growth quality improvement (funded by internal programs); (2) improvement in extraction efficiency from the LED package through improvement of InGaN-die-level and package-level optical extraction efficiency; and (3) improvement in phosphor

  3. The use of light-emitting diodes (LED in commercial layer production

    Directory of Open Access Journals (Sweden)

    R Borille

    2013-06-01

    Full Text Available Artificial lighting is one of the most powerful management tools available to commercial layer producers. Artificial light allows anticipating or delaying the beginning of lay, improving egg production, and optimizing feed efficiency. This study aimed at comparing the performance of commercial layers submitted to lighting using different LED colors or conventional incandescent lamps. The study was carried out in a layer house divided in isolated environments in order to prevent any influenced from the neighboring treatments. In total, 360 Isa Brown layers, with an initial age of 56 weeks, were used. The following light sources were used: blue LED, yellow LED, green LED, red LED, white LED, and 40W incandescent light. Birds in all treatment were submitted to a 17-h continuous lighting program, and were fed a corn and soybean meal-based diet. A completely randomized experimental design with subplots was applied, with 24 treatments (six light sources and four periods of three replicates. Egg production (% was significantly different (p0.05 by light source. It was concluded that the replacement of incandescent light bulbs by white and red LEDs does not cause any negative effect on the egg production of commercial layers.

  4. Developing a nurse-led clinic using transformational leadership.

    Science.gov (United States)

    Gousy, Mamood; Green, Kim

    2015-03-25

    Nurses are at the forefront of implementing and managing change, given constantly changing healthcare services and the increase in demand for health care. Therefore, it is important to identify the best style of leadership to engage nurses in implementing service-led improvements. This article explores the effects of transformational leadership in bringing about service-led improvements in health care, using the example of setting up a nurse-led acupuncture clinic to optimise the care of patients with chronic pain. Transformational leadership was used throughout the project - from the initial local planning, training and development, through to liaising with the appropriate staff and deciding on an evaluation strategy. Transformational leadership proved to be an effective way to engage and empower nurses and other members of the chronic pain team to enable them to achieve the project aims.

  5. Infrared LED Array For Silicon Strip Detector Qualification

    CERN Document Server

    Dirkes, Guido; Hartmann, Frank; Heier, Stefan; Schwerdtfeger, Wolfgang; Waldschmitt, M; Weiler, K W; Weseler, Siegfried

    2003-01-01

    The enormous amount of silicon strip detector modules for the CMS tracker requires a test-sytem to allow qualification of each individual detector module and its front-end electronics within minutes. The objective is to test the detector with a physical signal. Signals are generated in the detector by illumination with lightpulses emitted by a LED at 950~nm and with a rise time of 10~ns. In order to avoid a detector moving, an array of 64 LEDs is used, overlaping the complete detector width. The total length of an array is 15~cm. The spot size of an individual LED is controlled by apertures to illuminate about 25 strips. Furthermore it is possible to simulate the high leakage current of irradiated sensors by constant illumination of the sensor. This provides an effective mean to identfy pinholes on a sensor.

  6. Color Degradation of Textiles with Natural Dyes and of Blue Scale Standards Exposed to White LED Lamps:Evaluation of White LED Lamps for Effectiveness as Museum Lighting

    Science.gov (United States)

    Ishii, Mie; Moriyama, Takayoshi; Toda, Masahiro; Kohmoto, Kohtaro; Saito, Masako

    White light-emitting diodes (LED) are well suited for museum lighting because they emit neither UV nor IR radiation, which damage artifacts. The color degradation of natural dyes and blue scale standards (JIS L 0841) by white LED lamps are examined, and the performance of white LED lamps for museum lighting is evaluated. Blue scale standard grades 1-6 and silk fabrics dyed with 22 types of natural dyes classified as mid to highly responsive in a CIE technical report (CIE157:2004) were exposed to five types of white LED lamps using different luminescence methods and color temperatures. Color changes were measured at each 15000 lx·hr (500 lx at fabric surface × 300 hr) interval ten times. The accumulated exposure totaled 150000 lx·hr. The data on conventional white LED lamps and previously reported white fluorescent (W) and museum fluorescent (NU) lamps was evaluated. All the white LED lamps showed lower fading rates compared with a W lamp on a blue scale grade 1. The fading rate of natural dyes in total was the same between an NU lamp (3000 K) and a white LED lamp (2869 K). However, yellow natural dyes showed higher fading rates with the white LED lamp. This tendency is due to the high power characteristic of the LED lamp around 400-500 nm, which possibly contributes to the photo-fading action on the dyes. The most faded yellow dyes were Ukon (Curcuma longa L.) and Kihada (Phellodendron amurense Rupr.), and these are frequently used in historic artifacts such as kimono, wood-block prints, and scrolls. From a conservation point of view, we need to continue research on white LED lamps for use in museum lighting.

  7. Development of constant-power driving control for light-emitting-diode (LED) luminaire

    International Nuclear Information System (INIS)

    Huang, Bin-Juine; Chen, Chun-Wei; Ong, Chin-Dian; Du, Bo-Han; Hsu, Po-Chien

    2013-01-01

    The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (−1.7%) for constant-power driving, as compared to that of constant-current driving (−12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation. - Highlights: ► A constant-power driving technique is proposed for LED luminaire. ► A linear system dynamics model of LED luminaire is used in the control system design. ► The test shows that the feedback system accurately controls the input power. ► The LED illumination varies slightly (−1.7%) for constant-power driving.

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

    Science.gov (United States)

    2015-09-01

    usually on most of the time. • Consider replacing existing CFL, high-intensity discharge (HID), or halogen lamp light fixtures/ lamps with LED fixtures... lamps . What is the Technology? An LED is a semiconductor-diode that emits light when power is applied. A driver is used, much as a ballast, to...available in integrated luminaires that can be used to replace existing luminaires. LEDs are also available as direct replacement lamps for many

  9. Efficient conceptual design for LED-based pixel light vehicle headlamps

    Science.gov (United States)

    Held, Marcel Philipp; Lachmayer, Roland

    2017-12-01

    High-resolution vehicle headlamps represent a future-oriented technology that can be used to increase traffic safety and driving comfort. As a further development to the current Matrix Beam headlamps, LED-based pixel light systems enable ideal lighting functions (e.g. projection of navigation information onto the road) to be activated in any given driving scenario. Moreover, compared to other light-modulating elements such as DMDs and LCDs, instantaneous LED on-off toggling provides a decisive advantage in efficiency. To generate highly individualized light distributions for automotive applications, a number of approaches using an LED array may be pursued. One approach is to vary the LED density in the array so as to output the desired light distribution. Another notable approach makes use of an equidistant arrangement of the individual LEDs together with distortion optics to formulate the desired light distribution. The optical system adjusts the light distribution in a manner that improves resolution and increases luminous intensity of the desired area. An efficient setup for pixel generation calls for one lens per LED. Taking into consideration the limited space requirements of the system, this implies that the luminous flux, efficiency and resolution image parameters are primarily controlled by the lens dimensions. In this paper a concept for an equidistant LED array arrangement utilizing distortion optics is presented. The paper is divided into two parts. The first part discusses the influence of lens geometry on the system efficiency whereas the second part investigates the correlation between resolution and luminous flux based on the lens dimensions.

  10. 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.

  11. Design of High Efficiency Illumination for LED Lighting

    OpenAIRE

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

    2013-01-01

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

  12. A new LED light source for display cases

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten; Petersen, Paul Michael

    Abstract: We report a new LED light source suitable for illumination of gold objects. It has a variable correlated color temperature from 2760 K to 2200 K with a high color rendering index up to 97.......Abstract: We report a new LED light source suitable for illumination of gold objects. It has a variable correlated color temperature from 2760 K to 2200 K with a high color rendering index up to 97....

  13. The Development of LED-Based Dental Light Using a Multiplanar Reflector Design

    Directory of Open Access Journals (Sweden)

    Chi-Chang Hsieh

    2014-01-01

    Full Text Available A multiplanar reflector was designed to enhance the application efficiency of light-emitting diode (LED light sources that can be employed as LED-based dental lights. This study used a high-power LED developed by Nichia, that is, a single LED capable of providing a total luminous flux of 120 lm, as the primarily light source to design and develop an LED-based dental light. This LED complies with the international standards and regulations stipulated in ISO 9680:2007. The light spots produced by the prototype were rectangular, with a length of 200 mm and a width of 100 mm. These light spots achieved maximum illumination of 12,000 lux. The use of LEDs can reduce energy consumption from 50 W to 3 W, providing an energy saving of more than 90%.

  14. InGaN/GaN Nanowire LEDs and Lasers

    KAUST Repository

    Zhao, Chao

    2016-01-01

    The large specific surface, and the associated high density of surface states was found to limit the light output power and quantum efficiency of nanowire-array devices, despite their potential for addressing the “green-gap” and efficiency-droop issues. The phonon and carrier confinement in nanowires also led to junction heating, and reduced heat dissipation. In this paper, we will present our studies on effective surface states passivation in InGaN/GaN quantum-disks (Qdisks)-in-nanowire light-emitting diodes (LEDs) and lasers grown on silicon (Si), as well as our recent work on nanowires LEDs grown on bulk-metal, a non-conventional substrate.

  15. Influence of interconnection on the long-term reliability of UV LED packages

    Science.gov (United States)

    Nieland, S.; Mitrenga, D.; Karolewski, D.; Brodersen, O.; Ortlepp, T.

    2017-02-01

    High power LEDs have conquered the mass market in recent years. Besides the main development focus to achieve higher productivity in the field of visible semiconductor LED processing, the wavelength range is further enhanced by active research and development in the direction of UVA / UVB / UVC. UVB and UVC LEDs are new and promising due to their numerous advantages. UV LEDs emit in a near range of one single emission peak with a width (FWHM) below 15 nm compared to conventional mercury discharge lamps and xenon sources, which show broad spectrums with many emission peaks over a wide range of wavelengths. Furthermore, the UV LED size is in the range of a few hundred microns and offers a high potential of significant system miniaturization. Of course, LED efficiency, lifetime and output power have to be increased [1]. Lifetime limiting issues of UVB/UVC-LED are the very high thermal stress in the chip resulting from the higher forward voltages (6-10 V @ 350 mA), the lower external quantum efficiency, below 10 % (most of the power disappears as heat), and the thermal resistance Rth of conventional LED packages being not able to dissipate these large amounts of heat for spreading. Beside the circuit boards and submounts which should have maximum thermal conductivity, the dimension of contacts as well as the interconnection of UV LED to the submount/package determinates the resolvable amount of heat [2]. In the paper different innovative interconnection techniques for UVC-LED systems will be discussed focused on the optimization of thermal conductivity in consideration of the assembly costs. Results on thermal simulation for the optimal contact dimensions and interconnections will be given. In addition, these theoretical results will be compared with results on electrical characterization as well as IR investigations on real UV LED packages in order to give recommendations for optimal UV LED assembly.

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

    Indian Academy of Sciences (India)

    the natural convection heat transfer process of LED luminaries is simulated by compu- ... Heat dissipation has become one of the key problems limiting the large ... micro channel heat radiator, are able to reject heat efficiently, they may make LED ... convection heat transfer coefficient, for example, adopting finned surface to ...

  17. Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals

    KAUST Repository

    Tsai, Yu-Lin

    2015-11-23

    Green LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is so-called “green gap”. In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boosting light extraction efficiency of LEDs with an enhancement of 78% but also collimating the view angle of LEDs from 131.5゜to 114.0゜. This could be because the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs points the way towards a promising avenue of solid-state lighting.

  18. Bridging “green gap” of LEDs: Giant light output enhancement and directional control of LEDs via embedded nano-void photonic crystals

    KAUST Repository

    Tsai, Yu-Lin; Liu, Che-Yu; Krishnan, Chirenjeevi; Lin, Da-Wei; Chu, You-Chen; Chen, Tzu-Pei; Shen, Tien-Lin; Kao, Tsung-Sheng; Charlton, Martin; Yu, Peichen; Lin, Chien-Chung; Kuo, Hao-Chung; He, Jr-Hau

    2015-01-01

    Green LEDs do not show the same level of performance as their blue and red cousins, greatly hindering the solid-state lighting development, which is so-called “green gap”. In this work, nano-void photonic crystals (NVPCs) were fabricated to embed within the GaN/InGaN green LEDs by using epitaxial lateral overgrowth (ELO) and nano-sphere lithography techniques. The NVPCs act as an efficient scattering back-reflector to outcouple the guided and downward photons, which not only boosting light extraction efficiency of LEDs with an enhancement of 78% but also collimating the view angle of LEDs from 131.5゜to 114.0゜. This could be because the highly scattering nature of NVPCs which reduce the interference giving rise to Fabry-Perot resonance. Moreover, due to the threading dislocation suppression and strain relief by the NVPCs, the internal quantum efficiency was increased by 25% and droop behavior was reduced from 37.4% to 25.9%. The enhancement of light output power can be achieved as high as 151% at a driving current of 350 mA. Giant light output enhancement and directional control via NVPCs points the way towards a promising avenue of solid-state lighting.

  19. Direct battery-driven solar LED lighting using constant-power control

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result has shown that the power of 18. W and 100. W LED luminaires can be controlled accurately with error at 2-5%. A solar LED street lighting system using constant-power and dimming control was designed and built for field test in a remote area. The long-term performance was satisfactory and no any failure since the installation. Since no high-power capacitor is used in the present constant-power control circuit, a longer lifetime is expected. © 2012 Elsevier Ltd.

  20. An analysis of application of health informatics in Traditional Medicine: A review of four Traditional Medicine Systems.

    Science.gov (United States)

    Raja Ikram, Raja Rina; Abd Ghani, Mohd Khanapi; Abdullah, Noraswaliza

    2015-11-01

    This paper shall first investigate the informatics areas and applications of the four Traditional Medicine systems - Traditional Chinese Medicine (TCM), Ayurveda, Traditional Arabic and Islamic Medicine and Traditional Malay Medicine. Then, this paper shall examine the national informatics infrastructure initiatives in the four respective countries that support the Traditional Medicine systems. Challenges of implementing informatics in Traditional Medicine Systems shall also be discussed. The literature was sourced from four databases: Ebsco Host, IEEE Explore, Proquest and Google scholar. The search term used was "Traditional Medicine", "informatics", "informatics infrastructure", "traditional Chinese medicine", "Ayurveda", "traditional Arabic and Islamic medicine", and "traditional malay medicine". A combination of the search terms above was also executed to enhance the searching process. A search was also conducted in Google to identify miscellaneous books, publications, and organization websites using the same terms. Amongst major advancements in TCM and Ayurveda are bioinformatics, development of Traditional Medicine databases for decision system support, data mining and image processing. Traditional Chinese Medicine differentiates itself from other Traditional Medicine systems with documented ISO Standards to support the standardization of TCM. Informatics applications in Traditional Arabic and Islamic Medicine are mostly ehealth applications that focus more on spiritual healing, Islamic obligations and prophetic traditions. Literature regarding development of health informatics to support Traditional Malay Medicine is still insufficient. Major informatics infrastructure that is common in China and India are automated insurance payment systems for Traditional Medicine treatment. National informatics infrastructure in Middle East and Malaysia mainly cater for modern medicine. Other infrastructure such as telemedicine and hospital information systems focus its

  1. Materials and Designs for High-Efficacy LED Light Engines

    Energy Technology Data Exchange (ETDEWEB)

    Ibbetson, James [Cree, Inc., Durham, NC (United States); Gresback, Ryan [Cree, Inc., Durham, NC (United States)

    2017-09-28

    Cree, Inc. conducted a narrow-band downconverter (NBD) materials development and implementation program which will lead to warm-white LED light engines with enhanced efficacy via improved spectral efficiency with respect to the human eye response. New red (600-630nm) NBD materials could result in as much as a 20% improvement in warm-white efficacy at high color quality relative to conventional phosphor-based light sources. Key program innovations included: high quantum yield; narrow peak width; minimized component-level losses due to “cross-talk” and light scattering among red and yellow-green downconverters; and improved reliability to reach parity with conventional phosphors. NBD-enabled downconversion efficiency gains relative to conventional phosphors yielded an end-of-project LED light engine efficacy of >160 lm/W at room temperature and 35 A/cm2, with a correlated color temperature (CCT) of ~3500K and >90 CRI (Color Rending Index). NBD-LED light engines exhibited equivalent luminous flux and color point maintenance at >1,000 hrs. of highly accelerated reliability testing as conventional phosphor LEDs. A demonstration luminaire utilizing an NBD-based LED light engine had a steady-state system efficacy of >150 lm/W at ~3500K and >90 CRI, which exceeded the 2014 DOE R&D Plan luminaire milestone for FY17 of >150 lm/W at just 80 CRI.

  2. Intrapartum and neonatal mortality in primary midwife-led and secondary obstetrician-led care in the Amsterdam region of the Netherlands: A retrospective cohort study

    NARCIS (Netherlands)

    Wiegerinck, M.M.J.; van der Goes, B.Y.; Ravelli, A.C.J.; van der Post, J.A.M.; Klinkert, J.; Brandenbarg, J.; Buist, F.C.D.; Wouters, M.G.A.J.; Tamminga, P.; de Jonge, A.; Mol, B.W.

    2015-01-01

    Objective: to compare intrapartum- and neonatal mortality and intervention rates in term women starting labour in primary midwife-led versus secondary obstetrician-led care. Design: retrospective cohort study. Setting: Amsterdam region of the Netherlands. Participants: women with singleton

  3. Investigation of UV-LED Initiated Photopolymerisation of Bio-compatible HEMA

    OpenAIRE

    McDermott, Sharon

    2008-01-01

    Ultraviolet (UV) fluorescent lamps are widely used in photopolymerisation processes. However, there a number of disadvantages to these lamps, namely, their intensity varies over time and has to be constantly monitored. This thesis is concerned with the possibility of replacing these lamps with UV Light Emitting Diodes (UV-LEDs). A number of emission characteristics of both the fluorescent lamp and the UV-LEDs were measured and compared to ensure that the optical properties of the UV-LEDs were...

  4. LED deep UV source for charge management of gravitational reference sensors

    International Nuclear Information System (INIS)

    Sun Kexun; Allard, Brett; Buchman, Saps; Williams, Scott; Byer, Robert L

    2006-01-01

    Proof mass electrical charge management is an important functionality for the ST-7-LTP technology demonstration flight and for LISA. Photoemission for charge control is accomplished by using deep ultraviolet (UV) light to excite photoelectron emission from an Au alloy. The conventional UV source is a mercury vapour lamp. We propose and demonstrate charge management using a deep UV light emitting diode (LED) source. We have acquired selected AlGaN UV LEDs, characterized their performance and successfully used them to realize charge management. The UV LEDs emit at a 257 nm central wavelength with a bandwidth of ∼12 nm. The UV power for a free-space LED is ∼120 μW, and after fibre coupling is ∼16 μW, more than sufficient for LISA applications. We have directly observed the LED UV light-induced photocurrent response from an Au photocathode and an Au-coated GRS/ST-7 proof mass. We demonstrated fast switching of UV LEDs and associated fast changes in photocurrent. This allows modulation and continuous discharge to meet stringent LISA disturbance reduction requirements. We propose and demonstrate AC charge management outside the gravitational wave signal band. Further, the megahertz bandwidth for UV LED switching allows for up to six orders of magnitude dynamic power range and a number of novel modes of operations. The UV LED based charge management system offers the advantages of small-size, lightweight, fibre-coupled operation with very low power consumption

  5. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields.

    Science.gov (United States)

    Martínez, Eliana; Rös, Matthias; Bonilla, María Argenis; Dirzo, Rodolfo

    2015-01-01

    The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity.

  6. LED-lys til ældre: Lys, trivsel og alder - Hvordan hænger det sammen?

    DEFF Research Database (Denmark)

    Sander, Birgit Agnes; Kessel, Line; Ahmad, Hajer

    at forbedre søvnkvaliteten og dermed øge trivsel og aktivitetsniveau. Samtidig har markedet fået helt nye lyskilder som LED. De giver langt flere muligheder, end vi har været vant til med gløde- og halogenpærer og sparepærer. Glostrup Hospitals Øjenafdeling, DTU Fotonik, Statens Byggeforskningsinstitut, Gate...

  7. Finding Urban Identity through Culture-led Urban Regeneration

    Directory of Open Access Journals (Sweden)

    Kyu Hong Hwang

    Full Text Available ABSTRACT: A city experiencing a cycle from growth to decline cannot maintain sustainable development without the type of urban identity that could be consolidated by culture-led urban regeneration. A plan for urban regeneration in a declining urban area should be practiced partially or on the whole according to the characteristics of the community. By transforming a low-value and deteriorated area into a highly valued district, the local community can simultaneously restore its social pride, revive the local economy, and realize an urban identity.Firstly, this paper examines urban decline in order to better understand urban regeneration and the need for multidisciplinary management, and also, by considering the necessity for and universal types of urban regeneration, investigates the characteristics of culture-led urban regeneration as a tool for realizing socio-economic revival and urban identity. In particular, this study suggests the action techniques and benchmarking points for urban regeneration by analyzing cases of culture-led urban regeneration in Korea. Three subjects were considered as case studies in this paper: 1 Hanok village in Jeonju city, which changed from a twilight zone to a tourist attraction; 2 Changdong district in Changwon city, which recovered from an area of declining and dark alleyways that had been the hub for arts and culture in the 1970s to become a new artist village; and 3 Cheongju city, which is being transformed from an idle industrial facility into a cultural space. This thesis suggests the implementation process of culture-led urban regeneration to find an urban identity through analysis of the causes of urban decline, the methods of regeneration, and the results of urban regeneration in the three aforementioned cases. In the conclusion section of this paper, the implementation process for culture-led urban regeneration is summarized as consisting of 5 phases: Phase 1, the diagnosis of decline; Phase 2

  8. 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.

  9. Design of LED lamps | Ashryatov | Journal of Fundamental and ...

    African Journals Online (AJOL)

    Design of LED lamps. ... In this paper, we study the effect of LED high brightness on the brightness of a luminaire. The nomenclature of diffusers used in the production of ... The variant of the lighting system energy efficiency increase with luminaires and linear fluorescent lamps is considered. In the proposed variant, the ...

  10. LEDs Illuminate Bulbs for Better Sleep, Wake Cycles

    Science.gov (United States)

    2015-01-01

    Life on the International Space Station (ISS) wreaks havoc on an astronaut’s biological rhythms, and one way NASA mitigates the problem is through the use of LED lighting to alternately stimulate energy and focus and induce relaxation. Satellite Beach, Florida-based Lighting Science partnered with Kennedy Space Center to commercialize an LED system designed for the ISS, resulting in its DefinityDigital product line of light bulbs now used in numerous homes, hotel chains, and resorts.

  11. Policy environments matters: Access to higher education of non-traditional students in Denmark. Paper presented at the 56th CIES conference, San Juan, Puerto Rico, 22-27 April

    DEFF Research Database (Denmark)

    Milana, Marcella

    2012-01-01

    Despite the massification of higher education that has brought about an increase in the enrollment rates of non-traditional students, and the internationalization of higher education, which has led towards cross-national homogenization when it comes to the typology of educational programs run...... by universities, access of non-traditional students is still a much debated issue. The scope of this paper is to critically examine the policy environment, and related practice, which supports (or hampers) access to higher education of non-traditional students, with a special attention to adult and mature...... from a common ideal that results from cross-national cooperation implemented through the Bologna process. The data source includes relevant scientific literature, policy documents as well as interviews with policy makers, representatives of higher education institutions and non-traditional students...

  12. Head-mounted LED for optogenetic experiments of freely-behaving animal

    Science.gov (United States)

    Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

    2016-03-01

    Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

  13. Comparison of appendicectomy outcomes: acute surgical versus traditional pathway.

    Science.gov (United States)

    Pillai, Sandhya; Hsee, Li; Pun, Andy; Mathur, Sachin; Civil, Ian

    2013-10-01

    The acute surgical unit (ASU) is an evolving novel concept introduced to address the challenge of maintaining key performance indicators (KPIs) in the face of an increasing acute workload. The aim of this retrospective study was to compare the performance of the ASU (from June 2008 to December 2010) at Auckland City Hospital with the traditional model (from January 2006 to May 2008) and benchmark the results against other similar published studies. The analysis was on the basis of KPIs for 1857 appendicectomies, which form a large volume of acute surgical presentations. Our results show significant improvement in length of stay (2.8 days, 2.6 days, P = 0.0001) and proportion of daytime operations (59.4%, 65.8%, P = 0.004), in keeping with other studies on benchmarking. The introduction of ASU has led to significant improvements in some KPIs for appendicectomy outcomes in the face of an increasing workload. © 2013 Royal Australasian College of Surgeons.

  14. LED photochemotherapy against Staphylococcus aureus: an in vitro study

    Science.gov (United States)

    de Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Pires-Santos, Gustavo M.; Sampaio, Fernando José Pires; Soares, Luiz Guilherme P.; Soares, Amanda P.; Pinheiro, Antônio L. B.

    2018-02-01

    Bacterial resistance to antibiotics is reality and need for alternative treatments is urgent. The aim of this work was to evaluate, in vitro, the effect of LED photochemotherapy on Staphylococcus aureus (ATCC 23529) using 25 μg / mL of phenothiazine compound combined with LED light (λ632 +/- 2ηm) using 12 J/cm2 energy density. The experiments were carried out in triplicate and the samples were divided into groups: Control, Irradiated (treated only with light), Photosensitizer (treated only in the presence of the dye), LED-Photochemotherapy (treatment with light associated with dye). Counts of the colony forming units and the data obtained were statistically analyzed (ANOVA, Tukey's test, p<0.05). The present study demonstrated that the efficacy of LED-Photochemotherapy as the use of 25 μg/mL x 12 J/cm2 caused 91.57 % of inhibition of bacterial growth. It is concluded that using energy density of 12 J/cm2 associated to 25 μg/mL caused high in vitro inhibition of S. aureus.

  15. 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.

  16. Heterostructures for Increased Quantum Efficiency in Nitride LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Robert F. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2010-09-30

    Task 1. Development of an advanced LED simulator useful for the design of efficient nitride-based devices. Simulator will contain graphical interface software that can be used to specify the device structure, the material parameters, the operating conditions and the desired output results. Task 2. Theoretical and experimental investigations regarding the influence on the microstructure, defect concentration, mechanical stress and strain and IQE of controlled changes in the chemistry and process route of deposition of the buffer layer underlying the active region of nitride-based blue- and greenemitting LEDs. Task 3. Theoretical and experimental investigations regarding the influence on the physical properties including polarization and IQE of controlled changes in the geometry, chemistry, defect density, and microstructure of components in the active region of nitride-based blue- and green-emitting LEDs. Task 4. Theoretical and experimental investigations regarding the influence on IQE of novel heterostructure designs to funnel carriers into the active region for enhanced recombination efficiency and elimination of diffusion beyond this region. Task 5. Theoretical and experimental investigations regarding the influence of enhanced p-type doping on the chemical, electrical, and microstructural characteristics of the acceptor-doped layers, the hole injection levels at Ohmic contacts, the specific contact resistivity and the IQE of nitride-based blue- and green-emitting LEDs. Development and optical and electrical characterization of reflective Ohmic contacts to n- and p-type GaN films.

  17. From medical tradition to traditional medicine: A Tibetan formula in the European framework.

    Science.gov (United States)

    Schwabl, Herbert; Vennos, Cécile

    2015-06-05

    The increasing prevalence of complex multi-factorial chronic diseases and multimorbidity reveals the need for an enlargement of the therapeutic options. Potent multicompound herbal formulations from traditional medicine systems such as Tibetan Medicine might meet the requirements. With its practice over the centuries Tibetan Medicine is one of the important medical heritages of the world. In the 20th century Tibetan formulas came to Switzerland, where the formula Gabur-25 was then registered as medicine in 1977 (Padma 28, Swissmedic No 35872). The new European directive 2004/24/EC opened the avenue for traditional herbal medicinal products and registrations followed in Austria (HERB-00037) and the UK (39568/0001). The aim of this review was to analyse not only the critical points and hazards but also chances that occur in the endeavour of bringing a ethnopharmacological based preparation to the market within a modern Western medical and regulatory framework and to discuss the necessary transformation steps from a traditional herbal formula towards a modern pharmaceutical product with the example of the Tibetan formula Gabur-25. The historic transformation process from the 19th to the 21st century is analysed, using the registration documents and other material from the library of Padma AG, Hinwil, Switzerland. The transformation of a traditional formula into a modern traditional herbal medicinal product according to the present EU regulations is a multi faceted process. The modern indication represents only a small part of the possible traditional indications. Quality and product labelling has to be adopted to modern standards. The formula, once registered, is a fixed combination of herbal and mineral ingredients. Contrary to this the concept of Asian medical tradition allows a certain flexibility in the composition of an herbal formula. The ingredients are constantly adapted to local conditions, availability of raw material and therapeutic situation. The example

  18. Analysis of Corporal Punishment of Children in the Family based on the Semantic Reading of Traditional Islamic Narratives including the Word “Dharb” [Hitting

    Directory of Open Access Journals (Sweden)

    حمیدرضا بصیری

    2016-06-01

    Full Text Available There are various traditional Islamic narratives in relation to treating children. The common understanding of these narratives allows for the corporal punishment of children in the family, although some narratives forbid parents from such behavior. With reference to traditional Islamic texts, the word “hitting” (Arabic: dharb is the main and most frequently used word implying the permissibility of corporal punishment. An investigation of the use of the term “dharb” (Arabic: ضرب in the Quran, traditional Islamic narratives and the Arabic language reveals different instances of a general sense of “occurence” which can denote “doing or carrying out”. On this basis, a wide range of usages for this word in absolute terms (without preposition is conceivable with the meanings of protecting, financially supporting, guiding and nurturing children. It seems that limiting the meaning of dharb to corporal punishment in all traditional Islamic narratives without considering the other meanings has led to incorrect interpretations of such narratives.

  19. Intrapartum and neonatal mortality in primary midwife-led and secondary obstetrician-led care in the Amsterdam region of the Netherlands: A retrospective cohort study

    NARCIS (Netherlands)

    Wiegerinck, M. M. J.; van der Goes, B. Y.; Ravelli, A. C. J.; van der Post, J. A. M.; Klinkert, J.; Brandenbarg, J.; Buist, F. C. D.; Wouters, M. G. A. J.; Tamminga, P.; de jonge, A.; Mol, B. W.

    2015-01-01

    To compare intrapartum- and neonatal mortality and intervention rates in term women starting labour in primary midwife-led versus secondary obstetrician-led care. Retrospective cohort study. Amsterdam region of the Netherlands. Women with singleton pregnancies who gave birth beyond 37+0 weeks

  20. The genus Psiadia: Review of traditional uses, phytochemistry and pharmacology.

    Science.gov (United States)

    Mahadeo, Keshika; Grondin, Isabelle; Kodja, Hippolyte; Soulange Govinden, Joyce; Jhaumeer Laulloo, Sabina; Frederich, Michel; Gauvin-Bialecki, Anne

    2018-01-10

    The genus Psiadia Jacq. ex. Willd. belongs to the Asteraceae family and includes more than 60 species. This genus grows in tropical and subtropical regions, being especially well represented in Madagascar and the Mascarene Islands (La Réunion, Mauritius and Rodrigues). Several Psiadia species have been used traditionally for their medicinal properties in Africa and the Mascarene Islands. Based on traditional knowledge, various phytochemical and pharmacological studies have been conducted. However there are no recent papers that provide an overview of the medicinal potential of Psiadia species. Therefore, the aim of this review is to provide a comprehensive summary of the botany, phytochemistry and pharmacology of Psiadia and to highlight the gaps in our knowledge for future research opportunities. The available information on traditional uses, phytochemistry and biological activities of the genus Psiadia was collected from scientific databases through a search using the keyword 'Psiadia' in 'Google Scholar', 'Pubmed', 'Sciencedirect', 'SpringerLink', 'Web of Science', 'Wiley' and 'Scifinder'. Additionally, published books and unpublished Ph.D. and MSc. dissertations were consulted for botanical information and chemical composition. Historically, species of the genus Psiadia have been used to treat a wide range of ailments including abdominal pains, colds, fevers, bronchitis, asthma, rheumatoid arthritis, skin infections and liver disorders among others. Phytochemical works led to the isolation of flavonoids, phenylpropanoids, coumarins and terpenoids. Furthermore, phytochemical compositions of the essential oils of some species have been evaluated. Crude extracts, essential oils and isolated molecules showed in vitro pharmacological activities, such as antimicrobial, anti-viral, anti-inflammatory, antiplasmodial and antileishmanial activities. Crude extracts of Psiadia dentata and Psiadia arguta have specifically been found to be potentially useful for inhibition

  1. Estudo morfométrico da terapia LED de baixa potência em tendinite de ratos Morphometric study of low power LED therapy tendonitis in rats

    Directory of Open Access Journals (Sweden)

    José Mário Nunes da Silva

    2011-12-01

    Full Text Available A terapia LED de baixa potência possui efeitos analgésico e antiinflamatório. O objetivo desse estudo foi analisar a ação da terapia com LED de baixa potência na reparação tendínea por meio de histologia e histomorfometria. Foram usados 25 ratos Wistar, de 220 a 250 g, divididos em três grupos experimentais avaliados no 7º e 14º dia: A, tendinite induzida sem tratamento; B, tendinite induzida tratada com LED de baixa potência, densidade de energia 4 J/cm² por 120 segundos; e C, sem indução de tendinite. A histomorfometria mostrou-se altamente significativa (p0,05. As análises histológica e histomorfométrica demonstraram qualitativo e quantitativo aumento no número de fibroblastos aos sete dias de tratamento, e das fibras colágenas, aos 14 dias, para grupo tratado com LED de baixa potência em relação ao grupo sadio (C. O mesmo não foi percebido quando relacionado ao grupo tendinite (A14.The low power LED therapy has analgesic and anti-inflammatory effects. The objective of this study was to analyze the action of therapy with low power LED on the tendon repair, using histology and histomorphometry. Were used 25 Wistar rats, with 220 to 250 g, divided into three experimental groups (7 and 14 days: A7 and A14 induced tendonitis without treatment; B7 and B14, induced tendinitis treated with LED low power density energy 4 J /cm² for 120 seconds; and C, without induction of tendinitis. Histomorphometry was highly significant (p 0.05. Histology and histomorphometry analysis demonstrated qualitative and quantitative increase in the number of fibroblasts to seven days of treatment, and collagen fibers at 14 days for the group treated with LED low power compared to the healthy group (C. But it is unclear even when related to the tendinitis group (A14.

  2. Microbial UV fluence-response assessment using a novel UV-LED collimated beam system.

    Science.gov (United States)

    Bowker, Colleen; Sain, Amanda; Shatalov, Max; Ducoste, Joel

    2011-02-01

    A research study has been performed to determine the ultraviolet (UV) fluence-response of several target non-pathogenic microorganisms to UV light emitting diodes (UV-LEDs) by performing collimated beam tests. UV-LEDs do not contain toxic mercury, offer design flexibility due to their small size, and have a longer operational life than mercury lamps. Comsol Multiphysics was utilized to create an optimal UV-LED collimated beam design based on number and spacing of UV-LEDs and distance of the sample from the light source while minimizing the overall cost. The optimized UV-LED collimated beam apparatus and a low-pressure mercury lamp collimated beam apparatus were used to determine the UV fluence-response of three surrogate microorganisms (Escherichia coli, MS-2, T7) to 255 nm UV-LEDs, 275 nm UV-LEDs, and 254 nm low-pressure mercury lamps. Irradiation by low-pressure mercury lamps produced greater E. coli and MS-2 inactivation than 255 nm and 275 nm UV-LEDs and similar T7 inactivation to irradiation by 275 nm UV-LEDs. The 275 nm UV-LEDs produced more efficient T7 and E. coli inactivation than 255 nm UV-LEDs while both 255 nm and 275 nm UV-LEDs produced comparable microbial inactivation for MS-2. Differences may have been caused by a departure from the time-dose reciprocity law due to microbial repair mechanisms. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. 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.

  4. Performance of GaN-Based LEDs with Nanopatterned Indium Tin Oxide Electrode

    Directory of Open Access Journals (Sweden)

    Zhanxu Chen

    2016-01-01

    Full Text Available The indium tin oxide (ITO has been widely applied in light emitting diodes (LEDs as the transparent current spreading layer. In this work, the performance of GaN-based blue light LEDs with nanopatterned ITO electrode is investigated. Periodic nanopillar ITO arrays are fabricated by inductive coupled plasma etching with the mask of polystyrene nanosphere. The light extraction efficiency (LEE of LEDs can be improved by nanopatterned ITO ohmic contacts. The light output intensity of the fabricated LEDs with nanopatterned ITO electrode is 17% higher than that of the conventional LEDs at an injection current of 100 mA. Three-dimensional finite difference time domain simulation matches well with the experimental result. This method may serve as a practical approach to improving the LEE of the LEDs.

  5. 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.

  6. Design of a Multi-Color Lamp Using High Brightness RGB LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Song, S.B.; Kang, S.H.; Yeo, I.S. [Chonnam National University, Kwangju (Korea)

    2003-02-01

    This paper proposes the design of a multi-color lamp using high brightness RGB LEDs for color variation. Appropriate number of RGB LEDs is so chosen according to the color mixing theory that the overall LEDs represent a color temperature of 6500K. Also, the chosen RGB LEDs are suitably arranged by using an optical design program. The lamp has an internal controller circuit, so it can be directly connected to the existing incandescent lamp socket. It's main body is comprised of two PCB layers. The upper layer contains 44 LEDs and the lower one has a simple microcontroller-based PWM control circuit. The lamp has functions of both ON/OFF control and PWM control, and enables color variation of over 100,000 colors and of more than 10 patterns. (author). 7 refs., 11 figs., 3 tabs.

  7. Evaluation of a nurse-led haemophilia counselling service.

    LENUS (Irish Health Repository)

    O'Shea, Eadaoln

    2012-01-01

    Genetic counselling and testing for females with a family history of haemophilia has long been advocated. However, there is little research in regard to clients\\' satisfaction with the existing counselling models in haemophilia, and in particular with nurse-led clinics. The purpose of this study was to evaluate whether clients were satisfied with a nurse-led carrier testing clinic and counselling service. A retrospective quantitative study of clients\\' satisfaction and perceived knowledge was undertaken using an anonymous questionnaire. A sample of 42 women who had attended the clinic in the last 12 months was identified. The response rate for the study was 71% (n = 30).Two thirds of the respondents were 35 years of age or younger, 93% had a family history of haemophilia and 56% were diagnosed as carriers. Perceived understanding and knowledge increased significantly between the first and second appointments (p < 0.001). Overall, the study identified a high level of client satisfaction with the nurse-led carrier testing clinic and counselling service.

  8. Teaching design in the first years of a traditional mechanical engineering degree: methods, issues and future perspectives

    Science.gov (United States)

    Silva, Arlindo; Fontul, Mihail; Henriques, Elsa

    2015-01-01

    Engineering design is known as an answer to an ill-defined problem. As any answer to an ill-defined problem, it can never be completely right or absolutely wrong. The methods that universities use to teach engineering design, as a consequence of this, suffer from the same fate. However, the accumulated experience with the 'chalk and talk' teaching tradition has led to a reality in which the employers of fresh graduates are not happy with the engineers they are getting. Part of their complaints are related with the inability of recently graduate engineers to work in problems where the boundaries are not well defined, are interdisciplinary, require the use of effective communication and integrate non-technical issues. These skills are mostly absent from traditional engineering curricula. This paper demonstrates the implementation of engineering design perspectives enhancing some of the aforementioned skills in a traditional mechanical engineering curriculum. It emphasises in particular a design project that is tackled in a sequence of conventional courses with a focus that depends on the course objectives and disciplinary domain. This transdisciplinary design project conveys the idea (and effectively implements it concurrently) that design is multidisciplinary.

  9. Blue laser diode (LD) and light emitting diode (LED) applications

    International Nuclear Information System (INIS)

    Bergh, Arpad A.

    2004-01-01

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Blue laser diode (LD) and light emitting diode (LED) applications

    Energy Technology Data Exchange (ETDEWEB)

    Bergh, Arpad A [Optoelectronics Industry Development Association (OIDA), 1133 Connecticut Avenue, NW, Suite 600, Washington, DC 20036-4329 (United States)

    2004-09-01

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. 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.

  12. Peripheral venous catheter insertion simulation training: A randomized controlled trial comparing performance after instructor-led teaching versus peer-assisted learning.

    Science.gov (United States)

    Pelloux, Sophie; Grégoire, Arnaud; Kirmizigul, Patrice; Maillot, Sandrine; Bui-Xuan, Bernard; Llorca, Guy; Boet, Sylvain; Lehot, Jean-Jacques; Rimmelé, Thomas

    2017-12-01

    Peripheral venous catheter insertion is a procedural skill that every medical student should master. Training is often limited to a small number of students and is poorly evaluated. The objective of this study was to evaluate the performance of peer-assisted learning in comparison to instructor-led teaching for peripheral venous catheter insertion training. Students were randomized to the control group attending a traditional instructor-led training session (slideshow and demonstration by an anesthetist instructor, followed by training on a procedural simulator) or to the test group attending a peer-assisted training session (slideshow and demonstration video-recorded by the same instructor, followed by training on a procedural simulator). The primary endpoint was the performance of peripheral venous catheter insertion, assessed on procedural simulator one week later by blinded experts using a standardized 20-item grid. Students self-evaluated their confidence levels using a numeric 10-point scale. Eighty-six students were included, 73 of whom attended the assessment session. The median performance score was 12/20 [8-15] in the instructor-led teaching group versus 13/20 [11-15] in the peer-assisted learning group (P=0.430). Confidence levels improved significantly after the assessment session and were significantly higher in the peer-assisted learning group (7.6/10 [7.0-8.0] versus 7.0/10 [5.0-8.0], P=0.026). Peer-assisted learning is effective for peripheral venous catheter insertion training and can be as effective as instructor-led teaching. Given the large number of students to train, this finding is important for optimizing the cost-effectiveness of peripheral venous catheter insertion training. Copyright © 2017 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier Masson SAS. All rights reserved.

  13. The impact of gender ideologies on men's and women's desire for a traditional or non-traditional partner

    OpenAIRE

    Thomae, M.; Houston, Diane

    2016-01-01

    Two studies examine preferences for a long-term partner who conforms to traditional or non- traditional gender\\ud roles. The studies both demonstrate a link between benevolent sexism and preference for a traditional partner.\\ud However, Study 1 also demonstrates a strong preference among women for a non-traditional partner. We measured\\ud ambivalent sexist ideologies before introducing participants to either a stereotypically traditional or stereotypically non-traditional character of the opp...

  14. LED-Based High-Voltage Lines Warning System

    Directory of Open Access Journals (Sweden)

    Eldar MUSA

    2013-04-01

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

  15. Development of constant-power driving control for light-emitting-diode (LED) luminaire

    KAUST Repository

    Huang, Bin-Juine

    2013-01-01

    The illumination of an LED may be affected by operating temperature even under constant-current condition. A constant-power driving technique is proposed in the present study for LED luminaire. A linear system dynamics model of LED luminaire is first derived and used in the design of the feedback control system. The PI controller was designed and tuned taking into account the control accuracy and robust properties with respect to plant uncertainty and variation of operating conditions. The control system was implemented on a microprocessor and used to control a 150W LED luminaire. The test result shows that the feedback system accurately controls the input power of LED luminaire to within 1.3 per cent error. As the ambient temperature changes from 0 to 40 °C, the LED illumination varies slightly (-1.7%) for constant-power driving, as compared to that of constant-current driving (-12%) and constant-voltage driving (+50%). The constant-power driving has revealed advantage in stabilizing the illumination of LED under large temperature variation. © 2012 Elsevier Ltd. All rights reserved.

  16. Direct battery-driven solar LED lighting using constant-power control

    KAUST Repository

    Huang, Bin-Juine; Chen, Chun-Wei; Hsu, Po-Chien; Tseng, Wei-Min; Wu, Min-Sheng

    2012-01-01

    A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result

  17. Photoelectrochemical liftoff of LEDs grown on freestanding c-plane GaN substrates

    KAUST Repository

    Hwang, David

    2016-09-23

    We demonstrate a thin-film flip-chip (TFFC) process for LEDs grown on freestanding c-plane GaN substrates. LEDs are transferred from a bulk GaN substrate to a sapphire submount via a photoelectrochemical (PEC) undercut etch. This PEC liftoff method allows for substrate reuse and exposes the N-face of the LEDs for additional roughening. The LEDs emitted at a wavelength of 432 nm with a turn on voltage of ~3 V. Etching the LEDs in heated KOH after transferring them to a sapphire submount increased the peak external quantum efficiency (EQE) by 42.5% from 9.9% (unintentionally roughened) to 14.1% (intentionally roughened).

  18. Demonstration of 575-Mb/s downlink and 225-Mb/s uplink bi-directional SCM-WDM visible light communication using RGB LED and phosphor-based LED.

    Science.gov (United States)

    Wang, Yuanquan; Wang, Yiguang; Chi, Nan; Yu, Jianjun; Shang, Huiliang

    2013-01-14

    We propose and experimentally demonstrate a novel full-duplex bi-directional subcarrier multiplexing (SCM)-wavelength division multiplexing (WDM) visible light communication (VLC) system based on commercially available red-green-blue (RGB) light emitting diode (LED) and phosphor-based LED (P-LED) with 575-Mb/s downstream and 225-Mb/s upstream transmission, employing various modulation orders of quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM). For the downlink, red and green colors/wavelengths are assigned to carry useful information, while blue chip is just kept lighting to maintain the white color illumination, and for the uplink, the low-cost P-LED is implemented. In this demonstration, pre-equalization and post-equalization are also adopted to compensate the severe frequency response of LEDs. Using this scheme, 4-user downlink and 1-user uplink transmission can be achieved. Furthermore, it can support more users by adjusting the bandwidth of each sub-channel. Bit error rates (BERs) of all links are below pre-forward-error-correction (pre-FEC) threshold of 3.8x 10(-3) after 66-cm free-space delivery. The results show that this scheme has great potential in the practical VLC system.

  19. Light emitting diodes (LED): applications in forest and native plant nurseries

    Science.gov (United States)

    Thomas D. Landis; Jeremiah R. Pinto; R. Kasten Dumroese

    2013-01-01

    It was quotes like this that made us want to learn more about light emitting diodes (LED). Other than knowing that LEDs were the latest innovation in artificial lighting, we knew that we had a lot to learn. So we started by reviewing some of the basics. The following review is a brief synopsis of how light affects plants and some discussion about LED lighting. If you...

  20. CMOS-compatible plenoptic detector for LED lighting applications.

    Science.gov (United States)

    Neumann, Alexander; Ghasemi, Javad; Nezhadbadeh, Shima; Nie, Xiangyu; Zarkesh-Ha, Payman; Brueck, S R J

    2015-09-07

    LED lighting systems with large color gamuts, with multiple LEDs spanning the visible spectrum, offer the potential of increased lighting efficiency, improved human health and productivity, and visible light communications addressing the explosive growth in wireless communications. The control of this "smart lighting system" requires a silicon-integrated-circuit-compatible, visible, plenoptic (angle and wavelength) detector. A detector element, based on an offset-grating-coupled dielectric waveguide structure and a silicon photodetector, is demonstrated with an angular resolution of less than 1° and a wavelength resolution of less than 5 nm.

  1. New insights into consumer-led food product development

    DEFF Research Database (Denmark)

    Costa, Ana I. A.; Jongen, W.M.F.

    2006-01-01

    industry are described. Contrary to previous optimistic views, it is put forward that without significant changes taking place in the mindset of the organizations involved in Europe's food R&D, the way forward for consumer-led innovation strategies in the agri-business sector will be long and hard.......This paper builds upon a review of relevant marketing, consumer science and innovation management literature to introduce the concept of consumer-led new product development and describe its main implementation stages. The potential shortcomings of this concept's application in European food...

  2. Enabling factors for the improvement of nitride-based LED efficiency

    International Nuclear Information System (INIS)

    Laubsch, Ansgar; Bergbauer, Werner; Sabathil, Matthias; Peter, Matthias; Meyer, Tobias; Bruederl, Georg; Linder, Norbert; Streubel, Klaus; Oberschmid, Raimund; Hahn, Berthold; Wagner, Joachim

    2008-01-01

    Recent progress in the epitaxial growth of LEDs with InGaN/GaN quantum-well heterostructures has led to a significant enhancement of output power. In this talk, we will discuss the mechanisms limiting the devices' internal efficiency and identify enabling factors for further improvements. We compare samples with different Indium content as well as different design of the active layer. Although heteroepitaxial growth of GaN on sapphire generates high defect densities, non-radiative defect-related Shockley-Read-Hall recombination does not seem to substantially limit the efficiency of standard InGaN/GaN LED structures. We rather discuss a supplemental Auger-like non-radiative path for carrier recombination that becomes dominant at quantum-well carrier densities typical for LED operation. Additionally, the piezo-field induced reduced overlap of electron and hole wavefunction in standard c-plane grown InGaN quantum wells reduces the radiative recombination rate

  3. Delphi4LED - From measurements to standardized multi-domain compact models of LED : A new European R&D project for predictive and efficient multi-domain modeling and simulation of LEDs at all integration levels along the SSL supply chain

    NARCIS (Netherlands)

    Bornoff, R.; Hildenbrand, V.; Lungten, S.; Martin, G.; Marty, C.; Poppe, A.; Rencz, M.; Schilders, W.H.A.; Yu, Joan

    2016-01-01

    There are a few bottlenecks hampering efficient design of products on different integration lepels of the ssL supply chain. one major issue is that data sheet information propided about packaged LEDs is usually insufficient and inconsistent among different LED pendors. Many data such as temperature

  4. Radiation effects in pigtailed GaAs and GaA1As LEDs

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1981-06-01

    Permanent and transient radiation effects have been studied in Plessey pigtailed, high radiance GaAs and GaAlAs LEDs using neutron, gamma ray and X-ray sources. The radiation-induced source of degradation in these devices was determined by also examining both bare, unpigtailed LEDs and separate samples of the Corning fibers used as pigtails. No transient effects were observed in the unpigtailed LEDs during either pulsed neutron or X-ray exposure. In contrast, the Corning doped silica fibers exhibited strong transient attenuation following pulsed X-ray bombardment. Permanent neutron damage in these pigtailed LEDs consisted essentially of light output degradation in the LED itself. Permanent gamma ray effects due to a Co-60 irradiation of 1 megarad were restricted to a small increase in attenuation in the fiber. The two primary radiation effects were then transient attenuation in the fiber pigtail and permanent neutron-induced degradation of the LED

  5. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields.

    Directory of Open Access Journals (Sweden)

    Eliana Martínez

    Full Text Available The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity.

  6. An easy to deploy street light control system based on wireless communication and LED technology.

    Science.gov (United States)

    Elejoste, Pilar; Angulo, Ignacio; Perallos, Asier; Chertudi, Aitor; Zuazola, Ignacio Julio García; Moreno, Asier; Azpilicueta, Leire; Astrain, José Javier; Falcone, Francisco; Villadangos, Jesús

    2013-05-16

    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.

  7. 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.

  8. Daylight integrated illumination control of LED systems based on enhanced presence sensing

    NARCIS (Netherlands)

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

    2011-01-01

    Light emitting diodes (LEDs) are considered to become the dominant source of illumination in the future, offering long life times, energy efficiency and flexible tunability. The flexibility of adapting LED parameters offers multiple degrees of freedom in designing LED based lighting systems. In this

  9. 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.

  10. Unveiling Cebuano Traditional Healing Practices

    Directory of Open Access Journals (Sweden)

    ZachiaRaiza Joy S. Berdon

    2016-02-01

    Full Text Available This study aims to identify the features of Cebuano’s traditional healing practices. Specifically, it also answers the following objectives: analyze traditional healing in Cebuano’s perspectives, explain the traditional healing process practiced in terms of the traditional healers’ belief, and extrapolate perceptions of medical practitioners toward traditional healing. This study made use of qualitative approach, among five traditional healers who performed healing for not less than ten years, in the mountain barangays of Cebu City. These healers served as the primary informants who were selected because of their popularity in healing. The use of open-ended interview in local dialect and naturalistic observation provided a free listing of their verbatim accounts were noted and as primary narratives. Participation in the study was voluntary and participants were interviewed privately after obtaining their consent. The Cebuano traditional healing practices or “panambal” comprise the use of “himolso” (pulse-checking, “palakaw” (petition, “pasubay” (determining what causes the sickness and its possible means of healing, “pangalap” (searching of medicinal plants for “palina” (fumigation, “tayhop” (gentle-blowing, “tutho” (saliva-blowing,“tuob” (boiling, “orasyon” (mystical prayers, “hilot” (massage, and “barang” (sorcery. Though traditional with medical science disapproval, it contributes to a mystical identity of Cebuano healers, as a manifestation of folk Catholicism belief, in order to do a good legacy to the community that needs help. For further study, researchers may conduct further the studies on the: curative effects of medicinal plants in Cebu, psychological effect pulsechecking healed persons by the mananambal, and unmasking the other features of traditional healing.

  11. Social Capital of Non-Traditional Students at a German University. Do Traditional and Non-Traditional Students Access Different Social Resources?

    Science.gov (United States)

    Brändle, Tobias; Häuberer, Julia

    2015-01-01

    Social capital is of particular value for the acquisition of education. Not only does it prevent scholars from dropping out but it improves the educational achievement. The paper focuses on access to social resources by traditional and non-traditional students at a German university and asks if there are group differences considering this…

  12. Analyzing Thermal Module Developments and Trends in High-Power LED

    Directory of Open Access Journals (Sweden)

    Jung-Chang Wang

    2014-01-01

    Full Text Available The solid-state light emitting diode (SSLED has been verified as consumer-electronic products and attracts attention to indoor and outdoor lighting lamp, which has a great benefit in saving energy and environmental protection. However, LED junction temperature will influence the luminous efficiency, spectral color, life cycle, and stability. This study utilizes thermal performance experiments with the illumination-analysis method and window program (vapour chamber thermal module, VCTM V1.0 to investigate and analyze the high-power LED (Hi-LED lighting thermal module, in order to achieve the best solution of the fin parameters under the natural convection. The computing core of the VCTM program employs the theoretical thermal resistance analytical approach with iterative convergence stated in this study to obtain a numerical solution. Results showed that the best geometry of thermal module is 4.4 mm fin thickness, 9.4 mm fin pitch, and 37 mm fin height with the LED junction temperature of 58.8°C. And the experimental thermal resistances are in good agreement with the theoretical thermal resistances; calculating error between measured data and simulation results is no more than ±7%. Thus, the Hi-LED illumination lamp has high life cycle and reliability.

  13. Automated system for the determination of patterns of high-intensity LEDs

    International Nuclear Information System (INIS)

    Baly, L.; Bolaño, L.; Arteche, R.; Broco, Y.; Quesada, I.; Rodríguez, E.

    2008-01-01

    Determination of high-intensity LEDs lighting patterns is an important step for the simulation and planning of arrays of these devices configurations. Currently there are systems based on CCD cameras able to efficiently solve this problem, however the high cost of these is a limiting factor for use. Another limitation of CCD cameras, is that they are designed for light levels much lower than those produced by a high-intensity LED. In this paper we present an automated system for the determination of the intensity of LEDs based on the scan point to point patterns. The results of the analysis of a type of LED based on arrays of bars with built-in optical system is presented.

  14. Feasibility of LED-Assisted CMOS Camera: Contrast Estimation for Laser Tattoo Treatment

    Directory of Open Access Journals (Sweden)

    Ngot Thi Pham

    2018-04-01

    Full Text Available Understanding the residual tattoo ink in skin after laser treatment is often critical for achieving good clinical outcomes. The current study aims to investigate the feasibility of a light-emitting diode (LED-assisted CMOS camera to estimate the relative variations in tattoo contrast after the laser treatment. Asian mice were tattooed using two color inks (black and red. The LED illumination was a separate process from the laser tattoo treatment. Images of the ink tattoos in skin were acquired under the irradiation of three different LED colors (red, green, and blue for pre- and post-treatment. The degree of contrast variation due to the treatment was calculated and compared with the residual tattoo distribution in the skin. The black tattoo demonstrated that the contrast consistently decreased after the laser treatment for all LED colors. However, the red tattoo showed that the red LED yielded an insignificant contrast whereas the green and blue LEDs induced a 30% (p < 0.001 and 26% (p < 0.01 contrast reduction between the treatment conditions, respectively. The proposed LED-assisted CMOS camera can estimate the relative variations in the image contrast before and after the laser tattoo treatment.

  15. Baby-Led Introduction to SolidS (BLISS) study: a randomised controlled trial of a baby-led approach to complementary feeding.

    Science.gov (United States)

    Daniels, Lisa; Heath, Anne-Louise M; Williams, Sheila M; Cameron, Sonya L; Fleming, Elizabeth A; Taylor, Barry J; Wheeler, Ben J; Gibson, Rosalind S; Taylor, Rachael W

    2015-11-12

    In 2002, the World Health Organization recommended that the age for starting complementary feeding should be changed from 4 to 6 months of age to 6 months. Although this change in age has generated substantial debate, surprisingly little attention has been paid to whether advice on how to introduce complementary foods should also be changed. It has been proposed that by 6 months of age most infants will have developed sufficient motor skills to be able to feed themselves rather than needing to be spoon-fed by an adult. This has the potential to predispose infants to better growth by fostering better energy self-regulation, however no randomised controlled trials have been conducted to determine the benefits and risks of such a "baby-led" approach to complementary feeding. This is of particular interest given the widespread use of "Baby-Led Weaning" by parents internationally. The Baby-Led Introduction to SolidS (BLISS) study aims to assess the efficacy and acceptability of a modified version of Baby-Led Weaning that has been altered to address potential concerns with iron status, choking and growth faltering. The BLISS study will recruit 200 families from Dunedin, New Zealand, who book into the region's only maternity hospital. Parents will be randomised into an intervention (BLISS) or control group for a 12-month intervention with further follow-up at 24 months of age. Both groups will receive the standard Well Child care provided to all parents in New Zealand. The intervention group will receive additional parent contacts (n = 8) for support and education on BLISS from before birth to 12 months of age. Outcomes of interest include body mass index at 12 months of age (primary outcome), energy self-regulation, iron and zinc intake and status, diet quality, choking, growth faltering and acceptability to parents. This study is expected to provide insight into the feasibility of a baby-led approach to complementary feeding and the extent to which this method of

  16. Traditional medicine and genomics.

    Science.gov (United States)

    Joshi, Kalpana; Ghodke, Yogita; Shintre, Pooja

    2010-01-01

    'Omics' developments in the form of genomics, proteomics and metabolomics have increased the impetus of traditional medicine research. Studies exploring the genomic, proteomic and metabolomic basis of human constitutional types based on Ayurveda and other systems of oriental medicine are becoming popular. Such studies remain important to developing better understanding of human variations and individual differences. Countries like India, Korea, China and Japan are investing in research on evidence-based traditional medicines and scientific validation of fundamental principles. This review provides an account of studies addressing relationships between traditional medicine and genomics.

  17. 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.

  18. A novel dimmable LED driver with soft-start and UVLO circuits

    International Nuclear Information System (INIS)

    Jiang Jinguang; Tan Gaojian; Zhou Xifeng; Zhang Zeyu

    2015-01-01

    A fully integrated LED driver based on a current mode PWM boost DC—DC converter with constant output current is proposed. In order to suppress the inrush of current and the overshoot voltage at the start up state, a soft-start circuit is adopted. Additionally, to adjust the LED brightness without color variation over the full dimming range and achieve high efficiency, a PWM dimming circuit is presented. Furthermore, to keep the loop stability of the LED driver, an internal slope compensation network is designed to avoid the sub-harmonic oscillation when the duty cycle exceeds 50%. Finally, a UVLO circuit is adopted to improve the reliability of the LED driver against the input voltage changing. The LED driver has been fabricated with a standard 0.5 μm CMOS process, and only occupies 1.21 × 0.76 mm 2 . Experimental results show that the brightness of the LED can be adjusted by an off-chip PWM signal with a wide adjusting range. The inductor current and output current increase smoothly over the whole load range. The chip is in the UVLO condition when the input voltage is below 2.18 V and has achieved about 137 μs typical start-up time. (semiconductor integrated circuits)

  19. Traditional games in primary school curriculum

    OpenAIRE

    Popeska, Biljana; Jovanova-Mitkovska, Snezana

    2017-01-01

    Traditional games are cultural and national heritage. They, cultural and traditional activities transmitted from one generation to another, sharing different movement and cognitive games used in order to educate, to socialize, to share the experience and to influence toward development of young generation. The people create traditional games, and they represent the habits, culture and tradition of countries, region or even a town or village. There are lot of different traditional games. They ...

  20. A Comparison of Midwife-Led and Medical-Led Models of Care and Their Relationship to Adverse Fetal and Neonatal Outcomes: A Retrospective Cohort Study in New Zealand.

    Directory of Open Access Journals (Sweden)

    Ellie Wernham

    2016-09-01

    Full Text Available Internationally, a typical model of maternity care is a medically led system with varying levels of midwifery input. New Zealand has a midwife-led model of care, and there are movements in other countries to adopt such a system. There is a paucity of systemic evaluation that formally investigates safety-related outcomes in relationship to midwife-led care within an entire maternity service. The main objective of this study was to compare major adverse perinatal outcomes between midwife-led and medical-led maternity care in New Zealand.This was a population-based retrospective cohort study. Participants were mother/baby pairs for all 244,047 singleton, term deliveries occurring between 1 January 2008 and 31 December 2012 in New Zealand in which no major fetal, neonatal, chromosomal or metabolic abnormality was identified and the mother was first registered with a midwife, obstetrician, or general practitioner as lead maternity carer. Main outcome measures were low Apgar score at five min, intrauterine hypoxia, birth-related asphyxia, neonatal encephalopathy, small for gestational age (as a negative control, and mortality outcomes (perinatal related mortality, stillbirth, and neonatal mortality. Logistic regression models were fitted, with crude and adjusted odds ratios (ORs generated for each outcome for midwife-led versus medical-led care (based on lead maternity carer at first registration with 95% confidence intervals. Fully adjusted models included age, ethnicity, deprivation, trimester of registration, parity, smoking, body mass index (BMI, and pre-existing diabetes and/or hypertension in the model. Of the 244,047 pregnancies included in the study, 223,385 (91.5% were first registered with a midwife lead maternity carer, and 20,662 (8.5% with a medical lead maternity carer. Adjusted ORs showed that medical-led births were associated with lower odds of an Apgar score of less than seven at 5 min (OR 0.52; 95% confidence interval 0

  1. Colorimetric characterization of LED luminaires

    International Nuclear Information System (INIS)

    Costa, C L M; Vieira, R R; Pereira, R C; Silva, P V M; Oliveira, I A A; Sardinha, A S; Viana, D D; Barbosa, A H; Souza, L P; Alvarenga, A D

    2015-01-01

    The Optical Metrology Division of Inmetro – National Institute of Metrology, Quality and Technology has recently started the colorimetric characterization of lamps by implementing Correlated Color Temperature (CCT) and Color Rendering Index (CRI) measurements of incandescent lamps, followed by the CFL, and LED lamps and luminaires. Here we present the results for the verification of the color characterization of samples of SSL luminaires for public as well as indoor illumination that are sold in Brazil

  2. Smart lighting using LED luminaries

    NARCIS (Netherlands)

    Bhardwaj, S.; Ozcelebi, T.; Lukkien, J.J.

    2010-01-01

    The target of a smart lighting system is to control light sources in an environment (e.g. home, office) adaptively according to user contexts and preferences. Literature work in this area focuses on traditional light sources such as incandescent and fluorescent lights, whereas this paper takes a

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

    OpenAIRE

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

    2009-01-01

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

  4. 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.

  5. 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...

  6. TRADITIONAL CHINESE HERBAL MEDICINE

    NARCIS (Netherlands)

    ZHU, YP; WOERDENBAG, HJ

    1995-01-01

    Herbal medicine, acupuncture and moxibustion, and massage and the three major constituent parts of traditional Chinese medicine. Although acupuncture is well known in many Western countries, Chinese herbal medicine, the mos important part of traditional Chinese medicine, is less well known in the

  7. An improved arterial pulsation measurement system based on optical triangulation and its application in the traditional Chinese medicine

    Science.gov (United States)

    Wu, Jih-Huah; Lee, Wen-Li; Lee, Yun-Parn; Lin, Ching-Huang; Chiou, Ji-Yi; Tai, Chuan-Fu; Jiang, Joe-Air

    2011-08-01

    An improved arterial pulsation measurement (APM) system that uses three LED light sources and a CCD image sensor to measure pulse waveforms of artery is presented. The relative variations of the pulses at three measurement points near wrist joints can be determined by the APM system simultaneously. The height of the arterial pulsations measured by the APM system achieves a resolution of better than 2 μm. These pulsations contain useful information that can be used as diagnostic references in the traditional Chinese medicine (TCM) in the future.

  8. Development of efficient, radiation-insensitive GaAs:Zn LEDs

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1977-01-01

    Although amphoterically Si doped GaAs LEDs are commercially popular because of their high light output, they are extremely sensitive to irradiation. Therefore, it would be desirable to have a viable alternative available for radiation environment applications. In this work it is shown that by increasing the hole concentration in the active region of nonamphoterically doped GaAs LEDs, one can simultaneously achieve high light output and low radiation sensitivity. Experimental results indicate that the minority carrier lifetime is smaller in more heavily doped devices so that the lifetime-damage constant, tau/sub o/K, is also smaller. Hence, the heavily doped devices should have greater radiation hardness. Neutron-induced light output degradation data as a function of hole concentration confirm this conclusion. The results also show that the pre-irradiation light output is greatest in the heavily doped LEDs. The accompanying decrease of tau/sub o/ in the heavily doped devices indicates that the total minority carrier lifetime is at least partially controlled by the radiative lifetime; a requirement for simultaneously achieving radiation hardness and high initial light output. Finally, an experimental comparison with amphoterically Si doped LEDs shows that the heavily doped devices are superior for neutron fluences greater than 2 x 10 12 n/cm 2

  9. A self-calibrating led-based solar test platform

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Sylvester-Hvid, Kristian O.; Jørgensen, Mikkel

    2011-01-01

    A compact platform for testing solar cells is presented. The light source comprises a multi-wavelength high-power LED (light emitting diode) array allowing the homogenous illumination of small laboratory solar cell devices (substrate size 50 × 25 mm) within the 390–940 nm wavelength range......, it is possible to perform all the commonly employed measurements on the solar cell at very high speed without moving the sample. In particular, the LED-based illumination system provides an alternative to light-biased incident photon-to-current efficiency measurement to be performed which we demonstrate. Both...

  10. Improved InGaN LED System Efficacy and Cost via Droop Reduction

    Energy Technology Data Exchange (ETDEWEB)

    Wildeson, Isaac [Lumileds LLC, San Jose, CA (United States)

    2017-11-29

    Efficiency droop is a non-thermal process intrinsic to indium gallium nitride light emitting diodes (LEDs) in which the external quantum efficiency (EQE) decreases with increasing drive current density. Mitigating droop would allow one to reduce the size of LEDs driven at a given current or to drive LEDs of given size at higher current while maintaining high efficiencies. In other words, droop mitigation can lead to significant gains in light output per dollar and/or light output per watt of input power. This project set an EQE improvement goal at high drive current density which was to be attained by improving the LED active region design and growth process following a droop mitigation strategy. The interactions between LED active region design parameters and efficiency droop were studied by modeling and experiments. The crystal defects that tend to form in more complex LED designs intended to mitigate droop were studied with advanced characterization methods that provided insight into the structural and electronic properties of the material. This insight was applied to improve the epitaxy process both in terms of active region design and optimization of growth parameters. The final project goals were achieved on schedule and an epitaxy process leading to LEDs with EQE exceeding the project target was demonstrated.

  11. 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.

  12. Traditional medicine and genomics

    Directory of Open Access Journals (Sweden)

    Kalpana Joshi

    2010-01-01

    Full Text Available ′Omics′ developments in the form of genomics, proteomics and metabolomics have increased the impetus of traditional medicine research. Studies exploring the genomic, proteomic and metabolomic basis of human constitutional types based on Ayurveda and other systems of oriental medicine are becoming popular. Such studies remain important to developing better understanding of human variations and individual differences. Countries like India, Korea, China and Japan are investing in research on evidence-based traditional medicines and scientific validation of fundamental principles. This review provides an account of studies addressing relationships between traditional medicine and genomics.

  13. A new lifetime estimation model for a quicker LED reliability prediction

    Science.gov (United States)

    Hamon, B. H.; Mendizabal, L.; Feuillet, G.; Gasse, A.; Bataillou, B.

    2014-09-01

    LED reliability and lifetime prediction is a key point for Solid State Lighting adoption. For this purpose, one hundred and fifty LEDs have been aged for a reliability analysis. LEDs have been grouped following nine current-temperature stress conditions. Stress driving current was fixed between 350mA and 1A and ambient temperature between 85C and 120°C. Using integrating sphere and I(V) measurements, a cross study of the evolution of electrical and optical characteristics has been done. Results show two main failure mechanisms regarding lumen maintenance. The first one is the typically observed lumen depreciation and the second one is a much more quicker depreciation related to an increase of the leakage and non radiative currents. Models of the typical lumen depreciation and leakage resistance depreciation have been made using electrical and optical measurements during the aging tests. The combination of those models allows a new method toward a quicker LED lifetime prediction. These two models have been used for lifetime predictions for LEDs.

  14. KASTAMONU TRADITIONAL WOMEN CLOTHES

    Directory of Open Access Journals (Sweden)

    E.Elhan ÖZUS

    2015-08-01

    Full Text Available Clothing is a unique dressing style of a community, a period or a profession. In clothing there is social status and difference principle rather than fashion. In this context, the society created a clothing style in line with its own customs, traditions and social structure. One of the features separating societies from each other and indicating their cultural and social classes is the clothing style. As it is known, traditional Turkish clothes reflecting the characteristics of Turkish society is our most beautiful heritage from past to present. From this heritage there are several examples of women's clothes c arried to present. When these examples are examined, it is possible to see the taste, the way of understanding art, joy and the lifestyle of the history. These garments are also the documents outlining the taste and grace of Turkish people. In the present study, traditional Kastamonu women's clothing, that has an important place in traditional cultural clothes of Anatolia, is investigated . The method of the present research is primarily defined as the examination of the written sources. The study is complet ed with the observations and examinations made in Kastamonu. According to the findings of the study, traditional Kastamonu women's clothing are examined and adapted to todays’ clothing.

  15. Local resources, foreign influences, value creation, tradition and modernity. The case of a Local Agro-food System in Jämtland, Sweden

    Directory of Open Access Journals (Sweden)

    Rytkönen, Paulina

    2016-06-01

    Full Text Available During the 1980’s collective action was initiated with the purpose of saving the remnants of traditional livestock farming in Jämtland. This led to the articulation of a local agro-food system (LAFS that managed to commercialize important elements of traditional agriculture by adding elements of modernity. Farm diversification was an important strategy that led to the forward integration of farms that includes the start of small scale farm dairies, farm cafes, direct sales, at the farm, through markets and other local channels, B&Bs and outdoor tourism operations. In the mentioned process, foreign knowledge and experience led to the opening of a new market for traditional products. This case shows that the localization and appropriation of foreign elements can be a fruitful strategy to promote territorial development in regions like Jämtland. This article highlights how a LAFS was articulated within the frame of the birth of a new industry, composed by small, semi-artisan dairy firms and which institutional side effects that this experience has led to.Durante la década de los 80, un proceso de acción colectiva se inició con el propósito de salvar los restos de la ganadería tradicional en Jämtland. Esto resultó en la creación de un sistema agroalimentario local que logró comercializar elementos importantes de la agricultura tradicional, añadiendo elementos de modernidad. La diversificación de las fincas fue la estrategia más importante, dentro de la cual se promovió la creación de un sector de pequeñas industrias lácteas en las fincas, cafés rurales y asimismo la venta directa a los consumidores en dichas fincas, en mercados y otros canales de comercialización, servicios de alojamiento y desayuno y operaciones turísticas al aire libre. En este proceso, conocimiento y experiencias extranjeras jugaron un papel clave en la apertura de un nuevo mercado para los productos lácteos tradicionales. Este caso demuestra que la

  16. Weaknesses of 'wage-led growth'

    OpenAIRE

    Skott, Peter

    2016-01-01

    The emphasis in post-Keynesian macroeconomics on wage- versus profit- led growth may not have been helpful. The profit share is not an exogenous variable, and the correlations between the pro.t share and economic growth can be positive for some exogenous shocks but negative for others. The terminology, second, suggests a unidirectional causality from distribution to aggregate demand while in fact distribution can itself be directly affected by shifts in aggregate demand. The reduced form corr...

  17. VLC-based indoor location awareness using LED light and image sensors

    Science.gov (United States)

    Lee, Seok-Ju; Yoo, Jong-Ho; Jung, Sung-Yoon

    2012-11-01

    Recently, indoor LED lighting can be considered for constructing green infra with energy saving and additionally providing LED-IT convergence services such as visible light communication (VLC) based location awareness and navigation services. For example, in case of large complex shopping mall, location awareness to navigate the destination is very important issue. However, the conventional navigation using GPS is not working indoors. Alternative location service based on WLAN has a problem that the position accuracy is low. For example, it is difficult to estimate the height exactly. If the position error of the height is greater than the height between floors, it may cause big problem. Therefore, conventional navigation is inappropriate for indoor navigation. Alternative possible solution for indoor navigation is VLC based location awareness scheme. Because indoor LED infra will be definitely equipped for providing lighting functionality, indoor LED lighting has a possibility to provide relatively high accuracy of position estimation combined with VLC technology. In this paper, we provide a new VLC based positioning system using visible LED lights and image sensors. Our system uses location of image sensor lens and location of reception plane. By using more than two image sensor, we can determine transmitter position less than 1m position error. Through simulation, we verify the validity of the proposed VLC based new positioning system using visible LED light and image sensors.

  18. Characterization, reproduction and optimization of traditional adobe bricks

    Science.gov (United States)

    Ioannou, Ioannis; Eftychiou, Marina; Costi de Castrillo, Maria; Illampas, Rogiros

    2013-04-01

    Adobe bricks were first introduced 10-12,000 years ago. Extensive use of the material throughout the centuries has led to strong local traditions of building with earth and has established adobe masonry as an important feature of the international architectural heritage. Today, despite no longer being a prevalent building material, adobes are still in use, since a number of earthen structures survive worldwide. Furthermore, the simplicity, low cost and almost negligible embodied energy associated with the production of adobes, as well as their good thermal and acoustic properties, render them an attractive option for use in contemporary sustainable construction. Therefore, several ongoing research projects internationally investigate the physicochemical and mechanical properties of traditional adobe bricks and the design/production of optimized adobes, with improved characteristics, for use in contemporary architecture. Here, we present ongoing research on adobe bricks carried out in the framework of the project E& IXEIPH EI / POION/0609/41, which is co-funded by the European Regional Development Fund and the Republic of Cyprus, through the Cyprus Research Promotion Foundation. Our work focuses on the characterization of traditional adobes, their reproduction and optimization in the laboratory to produce materials with improved physicomechanical properties. Results up-to-date show that traditional adobes are mostly composed of random quantities of silt and clay. Calcite is also predominant in relevant X-ray diffraction analyses. The average capillary water absorption coefficient (measured against a saturated sponge surface) of samples collected from market suppliers rarely exceeds 1 mm/min1 -2, while their thermal conductivity is around 0.55 W/mK. The response of traditional adobes to compression is characterized by intense deformability. The average compressive strength recorded depends on the form of test specimen (cube, cylinder, prism). Samples with aspect

  19. Traditional Leadership and Independent Bantustans of South Africa: Some Milestones of Transformative Constitutionalism beyond Apartheid

    Directory of Open Access Journals (Sweden)

    SF Khunou

    2009-12-01

    Full Text Available The institution of traditional leadership represents the early form of societal organisation. It embodies the preservation of culture, traditions, customs and values. This paper gives a brief exposition of the impact that the pre-colonial and colonial regimes had on the institution of traditional leadership. During the pre-colonial era, the institution of traditional leadership was a political and administrative centre of governance for traditional communities. The institution of traditional leadership was the form of government with the highest authority. The leadership monopoly of traditional leaders changed when the colonial authorities and rulers introduced their authority to the landscape of traditional governance.The introduction of apartheid legalised and institutionalised racial discrimination. As a result, the apartheid government created Bantustans based on the language and culture of a particular ethnic group. This paper asserts that the traditional authorities in the Bantustans of Transkei, Bophuthatswana, Venda and Ciskei seemed to be used by the apartheid regime and were no longer accountable to their communities but to the apartheid regime. The Bantustans’ governments passed various pieces of legislation to control the institution of traditional leadership, exercised control over traditional leaders and allowed them minimal independence in their traditional role. The pattern of the disintegration of traditional leadership seemed to differ in Transkei, Bophuthatswana, Venda and Ciskei. The governments of these Bantustans used different political, constitutional and legal practices and methods to achieve this disintegration. The gradual disintegration and dislocation of the institution of traditional leadership in these four Bantustans led to the loss of valuable knowledge of the essence and relevance of the institution of traditional leadership. One of the reasons for this anomaly emanated from the fact that undemocratic

  20. An inverse method for color uniformity in white LED spotlights

    NARCIS (Netherlands)

    Prins, C.R.; Thije Boonkkamp, ten J.H.M.; Tukker, T.W.; IJzerman, W.L.

    2013-01-01

    Color over Angle (CoA) variation in the light output of white phosphor-converted LEDs is a common problem in LED lighting technology. In this article we propose an inverse method to design an optical element that eliminates the color variation for a point light source. The method in this article is