WorldWideScience

Sample records for led traditional storybook

  1. 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…

  2. 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…

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

    Science.gov (United States)

    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. 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

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

    NARCIS (Netherlands)

    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

  6. 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+ =…

  7. Storybook app creation demystified a cast study

    CERN Document Server

    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.

  8. 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.

  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. Think Scientifically: Science Hidden in a Storybook

    Science.gov (United States)

    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.; ;

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  13. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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.

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

    Science.gov (United States)

    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)…

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

    Science.gov (United States)

    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.…

  18. Interactive electronic storybooks for kindergartners to promote vocabulary growth

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

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

    NARCIS (Netherlands)

    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

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

    Science.gov (United States)

    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…

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

    OpenAIRE

    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...

  3. 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.

  4. 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....

  5. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  16. 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…

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

    Science.gov (United States)

    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…

  18. 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…

  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.

    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. 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…

  2. 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

  3. 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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  9. 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…

  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. "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.…

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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....

  7. 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…

  8. [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.

  9. 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

  10. 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

  11. 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...

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. 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....

  19. 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

  20. 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...

  1. 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

  2. Deep UV LEDs

    Science.gov (United States)

    Han, Jung; Amano, Hiroshi; Schowalter, Leo

    2014-06-01

    Deep ultraviolet (DUV) photons interact strongly with a broad range of chemical and biological molecules; compact DUV light sources could enable a wide range of applications in chemi/bio-sensing, sterilization, agriculture, and industrial curing. The much shorter wavelength also results in useful characteristics related to optical diffraction (for lithography) and scattering (non-line-of-sight communication). The family of III-N (AlGaInN) compound semiconductors offers a tunable energy gap from infrared to DUV. While InGaN-based blue light emitters have been the primary focus for the obvious application of solid state lighting, there is a growing interest in the development of efficient UV and DUV light-emitting devices. In the past few years we have witnessed an increasing investment from both government and industry sectors to further the state of DUV light-emitting devices. The contributions in Semiconductor Science and Technology 's special issue on DUV devices provide an up-to-date snapshot covering many relevant topics in this field. Given the expected importance of bulk AlN substrate in DUV technology, we are pleased to include a review article by Hartmann et al on the growth of AlN bulk crystal by physical vapour transport. The issue of polarization field within the deep ultraviolet LEDs is examined in the article by Braut et al. Several commercial companies provide useful updates in their development of DUV emitters, including Nichia (Fujioka et al ), Nitride Semiconductors (Muramoto et al ) and Sensor Electronic Technology (Shatalov et al ). We believe these articles will provide an excellent overview of the state of technology. The growth of AlGaN heterostructures by molecular beam epitaxy, in contrast to the common organo-metallic vapour phase epitaxy, is discussed by Ivanov et al. Since hexagonal boron nitride (BN) has received much attention as both a UV and a two-dimensional electronic material, we believe it serves readers well to include the

  3. 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.

  4. 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...

  5. Keeping Tradition

    NARCIS (Netherlands)

    Zenhong, C.; Buwalda, P.L.

    2011-01-01

    Chinese dumplings such as Jiao Zi and Bao Zi are two of the popular traditional foods in Asia. They are usually made from wheat flour dough (rice flour or starch is sometimes used) that contains fillings. They can be steamed, boiled and fried and are consumed either as a main meal or dessert. As

  6. 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....

  7. [Traditional nostrum].

    Science.gov (United States)

    Sugiyama, Shigeru

    2006-01-01

    The commercialization of drugs started toward the end of Heian period (794-1192) when not only aristocrats and monks who were traditional patrons to drug makers, but also local clans and landlords who became powerful as a result of the disbanding of aristocratic manors accumulated enough wealth to spend money on medicine. Although traveling around the country was still a dangerous endeavor, merchants assembled groups to bring lucrative foreign drugs (mainly Chinese) to remote areas. The spread of commercial drugs to common people, however, did not happen until the early Edo period (1603-1867), when the so-called barrier system was installed nationwide to make domestic travel safe. Commercialization started in large cities and gradually spread to other areas. Many nostrums popular until recently appeared in the Genroku period (1688-1703) or later. Many such nostrums were all-cures, often consisting of such active ingredients as Saussureae radix, Agalloch, or Gambir. Even in the Edo period, many people living in agricultural or fishing villages, as well as those in the lower tier, were still poor. Much of the medication available to those people was therefore made of various plant or animal-derived substances that were traditionally used as folk medicines.

  8. 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.

  9. 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...

  10. 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...

  11. 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

  12. 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.

  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. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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 ...

  19. 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.

  20. 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.

  1. 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.…

  2. 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…

  3. 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

  4. 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

  5. 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...

  6. 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.

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. LEDs light up the world

    Energy Technology Data Exchange (ETDEWEB)

    Mather, N.

    2004-06-30

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

  16. 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.

  17. 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.

  18. 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)

  19. 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...

  20. 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

  1. 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…

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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

  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. 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...

  9. 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

  10. 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

  11. 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.

  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. 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).

  14. 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.

  15. 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.

  16. 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.

  17. 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 ...

  18. 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.

  19. 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.

  20. 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

  1. 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

  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. 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.

  4. ‘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...

  5. 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...

  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. 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.

  8. 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...

  9. 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.

  10. 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

  11. 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

  12. 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...

  13. 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.

  14. 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.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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...

  2. [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.

  3. 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.

  4. 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....

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Portrait of a Teacher-Led School

    Science.gov (United States)

    Nazareno, Lori

    2013-01-01

    Imagine a school with no principal and with a leadership structure that holds teachers accountable for the learning of all students. About 50 such teacher-led schools currently operate across the United States, and this article tells the story of one of them. The Mathematics and Science Leadership Academy (MSLA) in Denver, Colorado, serves about…

  11. A community led tobacco free city

    Directory of Open Access Journals (Sweden)

    Najith Duminda Galmangoda Guruge

    2018-03-01

    Community led initiatives based on Health Promotion approach are effective in establishing 'Tobacco-free' cities. The community empowerment processes linked with such approaches can reduce the exposure to passive smoking, generating “smoke free cities” as well. Continuous vigilance at ground level and supportive actions from the national level are needed to sustain the results and enhance long term outcomes.

  12. Student-Led Conferences: Students Taking Responsibility

    Science.gov (United States)

    Nauss, Sherri A.

    2010-01-01

    One of the many challenges that face middle grade students, parents, and teachers is the student's lack of ownership of their academic achievements. Student-led conferences are a unique way to engage the student and the parent in the academic progress. Parents and teachers discuss the student's attitude toward the work, the student's work ethic in…

  13. LED Lighting in a Performing Arts Building

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-31

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

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Healthier Traditional Food

    OpenAIRE

    Edward F. Millen

    2017-01-01

    The study of traditional food and healthy eating habits has been one of the fast growing areas. All humans, both men and women, require food for their survival. However, both men and women indulge in food as if it were their sole purpose of existence. Hence, eating disorders are common among men and women. Then media has played an effective role not only in establishing faulty standards for traditional healthy food but also it has highlighted the importance of healthy eating. It has brought t...

  1. 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.

  2. 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....

  3. 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

  4. 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...

  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. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. Noodles, traditionally and today

    Directory of Open Access Journals (Sweden)

    Na Zhang

    2016-09-01

    Full Text Available Chinese noodles originated in the Han dynasty, which has more than 4,000 years of history. There are many stories about the origin of noodles. To a certain extent, noodles also reflect the cultural traditions and customs of China, which essentially means “human nature” and “worldly common sense”. There are thousands of varieties of noodles in China, according to the classification of the shape of noodles, seasoning gravy, cooking craft, and so on. Many noodles have local characteristics. Noodles are accepted by people from all over the world. The industrial revolution and the development of the food industry realized the transition from a traditional handicraft industry to mass production using machinery. In addition, the invention of instant noodles and their mass production also greatly changed the noodle industry. In essence, noodles are a kind of cereal food, which is the main body of the traditional Chinese diet. It is the main source of energy for Chinese people and the most economical energy food. Adhering to the principle of “making cereal food the main food”, is to maintain our Chinese good diet tradition, which can avoid the disadvantages of a high energy, high fat, and low carbohydrate diet, and promote health. The importance of the status of noodles in the dietary structure of residents in our country and the health impact should not be ignored.

  12. Traditional Cherokee Food.

    Science.gov (United States)

    Hendrix, Janey B.

    A collection for children and teachers of traditional Cherokee recipes emphasizes the art, rather than the science, of cooking. The hand-printed, illustrated format is designed to communicate the feeling of Cherokee history and culture and to encourage readers to collect and add family recipes. The cookbook could be used as a starting point for…

  13. Modern vs. Traditional.

    Science.gov (United States)

    Zhenhui, Rao

    1999-01-01

    This article discusses traditional methods, such as the grammar-translation, and modern methods, the communicative approach, for teaching English-as-a-foreign-language in China. The relationship between linguistic accuracy and communicative competence, student-centered orientation, and the role of the teacher are highlighted. (Author/VWL)

  14. Non-Traditional Wraps

    Science.gov (United States)

    Owens, Buffy

    2009-01-01

    This article presents a recipe for non-traditional wraps. In this article, the author describes how adults and children can help with the recipe and the skills involved with this recipe. The bigger role that children can play in the making of the item the more they are apt to try new things and appreciate the texture and taste.

  15. Making Tradition Healthy

    Centers for Disease Control (CDC) Podcasts

    2007-11-01

    In this podcast, a Latina nutrition educator shows how a community worked with local farmers to grow produce traditionally enjoyed by Hispanic/Latinos.  Created: 11/1/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health.   Date Released: 11/10/2007.

  16. 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.

  17. 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.

  18. Challenging tradition in Nigeria.

    Science.gov (United States)

    Supriya, K E

    1991-01-01

    In Nigeria since 1987, the National Association of Nigeria Nurses and Midwives (NSNNM) has used traditional medial and traditional health care workers to curtail the practice of female circumcision. Other harmful traditions are being changed also, such as early marriage, taboos of pregnancy and childbirth, and scarification. 30,000 member of NANNM are involved in this effort to halt the harmful practices themselves and to change community opinion. The program involved national and state level workshops on harmful health consequences of traditional practices and instruction on how to conduct focus group discussions to assess women's beliefs and practices. The focus groups were found to be a particularly successful method of opening up discussion of taboo topics and expressing deep emotions. The response to the knowledge that circumcision was not necessary was rage and anger, which was channeled into advocacy roles or change in the practice. The result was the channeled into advocacy roles for change in the practice. The result was the development of books, leaflets and videos. One community group designed a dress with a decorative motif of tatoos and bodily cuts to symbolize circumcision and scarring. Plays and songs were written and performed. Artists provided models of female genitalia both before and after circumcision. The campaign has been successful in bringing this issue to the public attention in prominent ways, such a national television, health talk shows, and women;s magazines. One of the most important results of the effort has been the demonstration that culture and tradition can be changed from within, rather than from outside imposition of values and beliefs.

  19. 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.)

  20. 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.

  1. 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.

  2. 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...

  3. 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.

  4. Sadum: Traditional and Contemporary

    Directory of Open Access Journals (Sweden)

    Ratna Panggabean

    2009-07-01

    Full Text Available Sadum is one of the traditional cloths of the Batak people in North Sumatra. It is woven on a back strap loom with supplementary weft technique. Sadum is a warp faced weaving made of cotton and beads woven into the cloth. Ritually it is used as a shoulder cloth, gifts exchanges, and in dances. It also bears the symbol of good tidings and blessings for the receiver. The cloth has change during times in technique, color, patterns, as well as in functions. But the use as a ritual cloth stays the same. The basic weaving techniques and equipments used to create it hasn’t change, but its material and added techniques has made this cloth become more rich in color, pattern, and texture. Most changes began when the Europeans came to Indonesia and introduced new material such as synthetic fibers and colors. In the 70s traditional cloth of Indonesia got its boost when the government declared batik as Indonesian national attire. This encourages other traditional weavings to develop into contemporary clothing. Later, new techniques and material were introduced to the Sadum weavings including embroidery, silk and golden threads which were never used before.

  5. 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...

  6. Moral Issues in Intelligence-led Policing

    DEFF Research Database (Denmark)

    The core baseline of Intelligence-led Policing is the aim of increasing efficiency and quality of police work, with a focus on crime analysis and intelligence methods as tools for informed and objective decisions both when conducting targeted, specialized operations and when setting strategic...... technological measures, increased private partnerships and international cooperation challenging the core nature of police services as the main providers of public safety and security? This book offers new insights by exploring dilemmas, legal issues and questions raised by the use of new policing methods...

  7. LED-technologies for bright light therapy

    Science.gov (United States)

    Kukhta, M. S.; Sidorenko, E. V.; Simutkin, G. G.; Khomushku, O. M.; Glushkov, G. S.

    2018-05-01

    The significance of the LED-based medical equipment design is caused by the need to make up for the sunshine shortfall in many areas of Russia (Siberia, the Far East, the Extreme North) that will allow reducing dramatically the risk of seasonal affective disorders. The sunshine is the essential synchronizer of the human biological rhythms, the abnormality of which plays an important role in the seasonal affective disorder nature. The study allows proving the object database development able to meet the human demand for a comfortable and high-quality placemaking as well as the health potential recoverability.

  8. Someone Has Led This Child To Believe

    OpenAIRE

    Louise, Regina

    2015-01-01

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

  9. 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

  10. 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

  11. Studying Light Color using White LED Lighting

    Science.gov (United States)

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

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

  12. LED Context Lighting System in Residential Areas

    Directory of Open Access Journals (Sweden)

    Sook-Youn Kwon

    2014-01-01

    Full Text Available As issues of environment and energy draw keen interest around the globe due to such problems as global warming and the energy crisis, LED with high optical efficiency is brought to the fore as the next generation lighting. In addition, as the national income level gets higher and life expectancy is extended, interest in the enhancement of life quality is increasing. Accordingly, the trend of lightings is changing from mere adjustment of light intensity to system lighting in order to enhance the quality of one’s life as well as reduce energy consumption. Thus, this study aims to design LED context lighting system that automatically recognizes the location and acts of a user in residential areas and creates an appropriate lighting environment. The proposed system designed in this study includes three types of processing: first, the creation of a lighting environment index suitable for the user’s surroundings and lighting control scenarios and second, it measures and analyzes the optical characteristics that change depending on the dimming control of lighting and applies them to the index. Lastly, it adopts PIR, piezoelectric, and power sensor to grasp the location and acts of the user and create a lighting environment suitable for the current context.

  13. 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.

  14. 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.

  15. 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.

  16. Traditional sorghum beer "ikigage"

    OpenAIRE

    Lyumugabe Loshima, François

    2010-01-01

    Samples of traditional sorghum beer Ikigage was collected in the southern province of Rwanda and analyzed for microbiological and physico-chemical contents. Ikigage contained total aerobic mesophilic bacteria (33.55 x 106 cfu/ml), yeast (10.15 x 106 cfu/ml), lactic acid bacteria (35.35 x 104 cfu/ml), moulds (4.12 x 104 cfu/ml), E. coli (21.90 x 103 cfu/ml), fecal streptococci (22.50 x 103 cfu/ml), Staphylococcus aureus (16.02 x 103 cfu/ml), total coliform (32.30 x 103 cfu/ml), eth...

  17. In the Dirac tradition

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1988-04-15

    It was Paul Dirac who cast quantum mechanics into the form we now use, and many generations of theoreticians openly acknowledge his influence on their thinking. When Dirac died in 1984, St. John's College, Cambridge, his base for most of his lifetime, instituted an annual lecture in his memory at Cambridge. The first lecture, in 1986, attracted two heavyweights - Richard Feynman and Steven Weinberg. Far from using the lectures as a platform for their own work, in the Dirac tradition they presented stimulating material on deep underlying questions.

  18. In the Dirac tradition

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    It was Paul Dirac who cast quantum mechanics into the form we now use, and many generations of theoreticians openly acknowledge his influence on their thinking. When Dirac died in 1984, St. John's College, Cambridge, his base for most of his lifetime, instituted an annual lecture in his memory at Cambridge. The first lecture, in 1986, attracted two heavyweights - Richard Feynman and Steven Weinberg. Far from using the lectures as a platform for their own work, in the Dirac tradition they presented stimulating material on deep underlying questions

  19. 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

  20. 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

  1. Assessing the colour quality of LED sources

    DEFF Research Database (Denmark)

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

    2015-01-01

    The CIE General Colour Rendering Index is currently the criterion used to describe and measure the colour-rendering properties of light sources. But over the past years, there has been increasing evidence of its limitations particularly its ability to predict the perceived colour quality of light...... sources and especially some LEDs. In this paper, several aspects of perceived colour quality are investigated using a side-by-side paired comparison method, and the following criteria: naturalness of fruits and vegetables, colourfulness of the Macbeth Color Checker chart, visual appreciation...... (attractiveness/ preference) and colour difference estimations for both visual scenes. Forty-five observers with normal colour vision evaluated nine light sources at 3000 K, and 36 observers evaluated eight light sources at 4000 K. Our results indicate that perceived colour differences are better dealt...

  2. LED--panacea or marketing hype?

    Science.gov (United States)

    Baillie, Jonathan

    2012-02-01

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

  3. Switched-capacitor isolated LED driver

    Science.gov (United States)

    Sanders, Seth R.; Kline, Mitchell

    2016-03-22

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

  4. Direct illumination LED calibration for telescope photometry

    International Nuclear Information System (INIS)

    Barrelet, E.; Juramy, C.

    2008-01-01

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

  5. Measurement of g Using a Flashing LED

    Science.gov (United States)

    Terzella, T.; Sundermier, J.; Sinacore, J.; Owen, C.; Takai, H.

    2008-10-01

    In one of the classic free-fall experiments, a small mass is attached to a strip of paper tape and both are allowed to fall through a spark timer, where sparks are generated at regular time intervals. Students analyze marks (dots) left on the tape by the timer, thereby generating distance-versus-time data, which they analyze to extract the acceleration due to gravity g with good results. The apparatus, however, is cumbersome and often frustrating for students. High-tech versions of this experiment are done with an object dropped and followed by a motion sensor connected to a computer. The sensor relies on ultrasonic ranging to record distance and time data, which may then be displayed graphically. Students inspect the graphs to determine the value of g. Although the results are excellent, the emphasis on the computer's ability to collect and analyze data leaves little analysis for the students to perform.2 Furthermore, neither technique gives an intuitive display of what is happening. The motivation for our work was to overcome these issues by developing an innovative method for measuring g. In our version of the experiment, students drop a flashing LED at a known frequency and record its trajectory using long exposure photography with a digital camera. Proper choice of flashing LED timing parameters produces an image that allows for an accurate measurement of g and at the same time helps to explain what happens during free fall. The experiment remains high-tech in the sense that students learn to use updated equipment to record data and to carry out the analysis.

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

    Science.gov (United States)

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

    2015-01-01

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

  7. 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.

  8. 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.

  9. 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 ...

  10. POWERED LED LIGHTING SUPPLIED FROM PV CELLS

    Directory of Open Access Journals (Sweden)

    Tirshu M.

    2011-12-01

    Full Text Available The paper deals with practical realization of efficient lighting system based on LED’s of 80W total power mounted on corridor ceiling total length of which is 120m and substitutes existing traditional lighting system consisting of 29 lighting blocks with 4 fluorescent lamps each of them and summary power 2088W. Realized lighting system is supplied from two photovoltaic panels of power 170W. Generated energy by PV cells is accumulated in two accumulators of 75Ah capacity and from battery by means of specialized convertor is applied to lighting system. Additionally, paper present data measured by digital weather station (solar radiation and UV index, which is mounted near of PV cells and comparative analyze of solar energy with real energy generated by PV cells is done. Measured parameters by digital weather station are stored by computer in on-line mode.

  11. Non-traditional inheritance

    International Nuclear Information System (INIS)

    Hall, J.G.

    1992-01-01

    In the last few years, several non-traditional forms of inheritance have been recognized. These include mosaicism, cytoplasmic inheritance, uniparental disomy, imprinting, amplification/anticipation, and somatic recombination. Genomic imprinting (GI) is the dependence of the phenotype on the sex of the transmitting parent. GI in humans seems to involve growth, behaviour, and survival in utero. The detailed mechanism of genomic imprinting is not known, but it seems that some process is involved in turning a gene off; this probably involves two genes, one of which produces a product that turns a gene off, and the gene that is itself turned off. The process of imprinting (turning off) may be associated with methylation. Erasure of imprinting can occur, and seems to be associated with meiosis. 10 refs

  12. 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...

  13. Led Astray by Hemoglobin A1c

    Directory of Open Access Journals (Sweden)

    Jean Chen MD

    2016-01-01

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

  14. Blue LED irradiation to hydration of skin

    Science.gov (United States)

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

    2015-06-01

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

  15. 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. 

  16. 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%.

  17. 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.

  18. 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.

  19. Validating Community-Led Forest Biomass Assessments.

    Science.gov (United States)

    Venter, Michelle; Venter, Oscar; Edwards, Will; Bird, Michael I

    2015-01-01

    The lack of capacity to monitor forest carbon stocks in developing countries is undermining global efforts to reduce carbon emissions. Involving local people in monitoring forest carbon stocks could potentially address this capacity gap. This study conducts a complete expert remeasurement of community-led biomass inventories in remote tropical forests of Papua New Guinea. By fully remeasuring and isolating the effects of 4,481 field measurements, we demonstrate that programmes employing local people (non-experts) can produce forest monitoring data as reliable as those produced by scientists (experts). Overall, non-experts reported lower biomass estimates by an average of 9.1%, equivalent to 55.2 fewer tonnes of biomass ha(-1), which could have important financial implications for communities. However, there were no significant differences between forest biomass estimates of expert and non-expert, nor were there significant differences in some of the components used to calculate these estimates, such as tree diameter at breast height (DBH), tree counts and plot surface area, but were significant differences between tree heights. At the landscape level, the greatest biomass discrepancies resulted from height measurements (41%) and, unexpectedly, a few large missing trees contributing to a third of the overall discrepancies. We show that 85% of the biomass discrepancies at the tree level were caused by measurement taken on large trees (DBH ≥50 cm), even though they consisted of only 14% of the stems. We demonstrate that programmes that engage local people can provide high-quality forest carbon data that could help overcome barriers to reducing forest carbon emissions in developing countries. Nonetheless, community-based monitoring programmes should prioritise reducing errors in the field that lead to the most important discrepancies, notably; overcoming challenges to accurately measure large trees.

  20. 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.

  1. 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.)

  2. 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.

  3. 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.

  4. 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

  5. Can the computer replace the adult for storybook reading? A meta-analysis on the effects of multimedia stories as compared to sharing print stories with an adult.

    Science.gov (United States)

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

    2014-01-01

    The present meta-analysis challenges the notion that young children necessarily need adult scaffolding in order to understand a narrative story and learn words as long as they encounter optimally designed multimedia stories. Including 29 studies and 1272 children, multimedia stories were found more beneficial than encounters with traditional story materials that did not include the help of an adult for story comprehension (g+ = 0.40, k = 18) as well as vocabulary (g+ = 0.30, k = 11). However, no significant differences were found between the learning outcomes of multimedia stories and sharing traditional print-like stories with an adult. It is concluded that multimedia features like animated illustrations, background music and sound effects provide similar scaffolding of story comprehension and word learning as an adult.

  6. Can the computer replace the adult for storybook reading? A meta-analysis on the effects of multimedia stories as compared to sharing print stories with an adult.

    Directory of Open Access Journals (Sweden)

    Zsofia Katalin Takacs

    2014-12-01

    Full Text Available The present meta-analysis challenges the notion that young children necessarily need adult scaffolding in order to understand a narrative story and learn words as long as they encounter optimally designed multimedia stories. Including 29 studies and 1272 children, multimedia stories were found more beneficial than encounters with traditional story materials that did not include the help of an adult for story comprehension (g+ = 0.40, k = 18 as well as vocabulary (g+ = 0.30, k = 11. However, no significant differences were found between the learning outcomes of multimedia stories and sharing traditional print-like stories with an adult. It is concluded that multimedia features like animated illustrations, background music and sound effects provide similar scaffolding of story comprehension and word learning as an adult.

  7. 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.

  8. 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)

  9. Is Nigerian Growth Trade-Led?

    Directory of Open Access Journals (Sweden)

    Ismail Adigun Olayemi

    2017-09-01

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

  10. 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, ...

  11. 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

  12. The Hausa Lexicographic Tradition

    Directory of Open Access Journals (Sweden)

    Roxana Ma Newman

    2011-10-01

    Full Text Available

    Abstract: Hausa, a major language of West Africa, is one of the most widely studied languagesof Sub-Saharan Africa. It has a rich lexicographic tradition dating back some two centuries. Sincethe first major vocabulary published in 1843 up to the present time, almost 60 lexicographic works— dictionaries, vocabularies, glossaries — have been published, in a range of metalanguages, fromEnglish to Hausa itself. This article traces the historical development of the major studies accordingto their type and function as general reference works, specialized works, pedagogical works, andterminological works. For each work, there is a general discussion of its size, accuracy of the phonological,lexical, and grammatical information, and the adequacy of its definitions and illustrativematerial. A complete list of the lexicographic works is included.

    Keywords: ARABIC, BILINGUAL LEXICOGRAPHY, DIALECTAL VARIANTS, DICTIONARIES,ENGLISH, ETYMOLOGIES, FRENCH, GERMAN, GLOSSARIES, GRAMMATICALCATEGORIES, HAUSA, LANGUAGE LEARNING, LOANWORDS, NEOLOGISMS, NIGER,NIGERIA, ORTHOGRAPHY, PHONETIC TRANSCRIPTION, PHONOLOGY, RUSSIAN, STANDARDDIALECT, STANDARDIZATION, TERMINOLOGY, VOCABULARIES, WEST AFRICA.

    Opsomming: Die leksikografiese tradisie in Hausa. Hausa, 'n belangrike taal vanWes-Afrika, is een van die tale van Afrika suid van die Sahara wat die wydste bestudeer word. Dithet 'n ryk leksikografiese tradisie wat ongeveer twee eeue oud is. Van die eerste groot woordeboekwat in 1843 gepubliseer is tot die hede is ongeveer 60 leksikografiese werke — woordeboeke,naamlyste, woordelyste — gepubliseer in 'n reeks metatale van Engels tot Hausa self. Hierdie artikelgaan die historiese ontwikkeling van die groter studies aan die hand van hulle tipe en funksieas algemene naslaanwerke, gespesialiseerde werke, opvoedkundige werke, en terminologiesewerke na. Vir elke werk is daar 'n algemene bespreking oor sy grootte, akkuraatheid van die fonologiese,leksikale en

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Attitudes of radiographers to radiographer-led discharge: A survey

    International Nuclear Information System (INIS)

    Lumsden, Laura; Cosson, Philip

    2015-01-01

    Background: The traditional role of the Diagnostic Radiographer in image acquisition has gradually been extended through skill-mix, particularly to include abnormality detection. Aims: This research focused on the attitudes of Radiographers to Radiographer-led Discharge (RLD), where Radiographers discharge patients with minor injuries and perform tasks previously undertaken by Accident and Emergency staff. The effects of job role, hospital type, experience and whether RLD was used in the participant's trust were examined. Method: A multiple-indicator online questionnaire assessed attitudes to RLD. Snowball sampling was used with advertisement via emails, posters and cards, containing Quick Response (QR) codes. Statement responses were coded, with reverse coding for negative statements and total scores were calculated. A higher score represented a more positive attitude. Results: 101 questionnaires were completed (an estimated 30% response rate) and the mean total score was 84/115. 95% of participants supported radiographer involvement in abnormality detection, with 46.5% selecting RLD as the preferred system for minor injuries patients vs 48.5% preferring commenting alone. Discussion: Participants were positive about extending their role through RLD and felt confident in their image interpretation abilities, though expressed concern for the legal consequences of the role and adequate pay. Generalization of the results is limited due to the possible low response rate. Conclusion: Overall, participants demonstrated positive attitudes towards RLD but they also indicate the need for appropriate payment for any additional responsibility. These findings are promising for successful implementation of RLD, though larger-scale research including radiologists, business managers, A and E staff and patients would be beneficial. - Highlights: • 101 questionnaires were completed (an estimated 30% response rate). • 95% of participants supported radiographer involvement

  5. 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.

  6. 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.

  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. An mHealth monitoring system for traditional birth attendant-led antenatal risk assessment in rural Guatemala.

    Science.gov (United States)

    Stroux, Lisa; Martinez, Boris; Coyote Ixen, Enma; King, Nora; Hall-Clifford, Rachel; Rohloff, Peter; Clifford, Gari D

    Limited funding for medical technology, low levels of education and poor infrastructure for delivering and maintaining technology severely limit medical decision support in low- and middle-income countries. Perinatal and maternal mortality is of particular concern with millions dying every year from potentially treatable conditions. Guatemala has one of the worst maternal mortality ratios, the highest incidence of intra-uterine growth restriction (IUGR), and one of the lowest gross national incomes per capita within Latin America. To address the lack of decision support in rural Guatemala, a smartphone-based system is proposed including peripheral sensors, such as a handheld Doppler for the identification of foetal compromise. Designed for use by illiterate birth attendants, the system uses pictograms, audio guidance, local and cloud processing, SMS alerts and voice calling. The initial prototype was evaluated on 22 women in highland Guatemala. Results were fed back into the refinement of the system, currently undergoing RCT evaluation.

  9. Repurposing traditional instructor-led lectures for continuing education: rewarding instructors as authors and maximizing return on investment.

    Science.gov (United States)

    Rushinek, Avi; Rushinek, Sara; Lippincott, Christine; Ambrosia, Todd

    2014-04-01

    The aim of this article is to describe the repurposing of classroom video surveillance and on-screen archives (RCVSOSA) model, which is an innovative, technology-enabled approach to continuing education in nursing. The RCVSOSA model leverages network Internet-protocol, high-definition surveillance cameras to record videos of classroom lectures that can be automatically uploaded to the Internet or converted to DVD, either in their entirety or as content-specific modules, with the production work embedded in the technology. The proposed model supports health care continuing education through the use of online assessments for focused education modules, access to archived online recordings and DVD training courses, voice-to-text transcripts, and possibly continuing education modules that may be translated into multiple languages. Potential benefits of this model include increased access to educational modules for students, instant authorship, and financial compensation for instructors and their respective organizations.

  10. How 'Digital' is Traditional Crime?

    NARCIS (Netherlands)

    Montoya, L.; Junger, Marianne; Hartel, Pieter H.

    Measuring how much cybercrime exists is typically done by first defining cybercrime and then quantifying how many cases fit that definition. The drawback is that definitions vary across countries and many cybercrimes are recorded as traditional crimes. An alternative is to keep traditional

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Intelligent control of dynamic LED lighting; Intelligent styring af dynamisk LED belysning. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, A.; Corell, D.; Hansen, Soeren S.; Dam-Hansen, C.; Petersen, Paul Michael

    2013-01-15

    The project has resulted in a prototype of a new intelligent lighting control system. The control system enables the end user to control his or her own local lighting environment (lighting zone) according to individual preferences and needs. The report provides a description of how the developed intelligent lighting system is composed and functions. The system is designed as a work lamp that enables dynamic change of the light color scheme according to a number of light control algorithms. It is specifically designed in relation to user tests of the intelligent lighting system, which is carried out in the final part of the project. An intelligent and advanced control of LED lighting was developed, which enables optimization of the user's light conditions in a given situation. Based on a number of known parameters, the system can control lighting so that at any time optimal light conditions are created, using a minimum of electric power. (LN)

  17. 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.

  18. 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

  19. 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.

  20. '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...

  1. 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

  2. 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.

  3. 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...

  4. 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.

  5. 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.

  6. 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

  7. Aurorae in Australian Aboriginal Traditions

    Science.gov (United States)

    Hamacher, Duane W.

    2013-07-01

    Transient celestial phenomena feature prominently in the astronomical knowledge and traditions of Aboriginal Australians. In this paper, I collect accounts of the Aurora Australis from the literature regarding Aboriginal culture. Using previous studies of meteors, eclipses, and comets in Aboriginal traditions, I anticipate that the physical properties of aurora, such as their generally red colour as seen from southern Australia, will be associated with fire, death, blood, and evil spirits. The survey reveals this to be the case and also explores historical auroral events in Aboriginal cultures, aurorae in rock art, and briefly compares Aboriginal auroral traditions with other global indigenous groups, including the Maori of New Zealand.

  8. 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…

  9. Traditional birth attendants in Malawi

    Directory of Open Access Journals (Sweden)

    J. J. M. Smit

    1994-03-01

    Full Text Available Traditional Birth Attendants (TBAs and traditional healers form an important link in the chain of health personnel providing primary health care in Malawi. In spite of the establishment of hospitals and health centres, it is to these traditional healers and TBAs that the majority of people turn in times of sickness and child-birth. Approximately 60 percent of all deliveries in Malawi occur in the villages. It is therefore important that due regard be paid to the activities of these traditional practitioners in order to ensure the achievement of the goal - "Health for all by the year 2000". The training of TBAs is seen as part of the Maternal and Child Health Services in the country.

  10. Traditional birth attendants in Malawi

    Directory of Open Access Journals (Sweden)

    J. J. M. Smit

    1994-05-01

    Full Text Available Traditional Birth Attendants (TBAs and traditional healers form an important link in the chain of health personnel providing primary health care in Malawi. In spite of the establishment of hospitals and health centres, it is to these traditional healers and TBAs that the majority of people turn in times of sickness and child-birth. Approximately 60 percent of all deliveries in Malawi occur in the villages. It is therefore important that due regard be paid to the activities of these traditional practitioners in order to ensure the achievement of the goal - "Health for all by the year 2000". The training of TBAs is seen as part of the Maternal and Child Health Services in the country.

  11. [Common household traditional Chinese medicines].

    Science.gov (United States)

    Zhang, Shu-Yuan; Li, Mei; Fu, Dan; Liu, Yang; Wang, Hui; Tan, Wei

    2016-02-01

    With the enhancement in the awareness of self-diagnosis among residents, it's very common for each family to prepare common medicines for unexpected needs. Meanwhile, with the popularization of the traditional Chinese medicine knowledge, the proportion of common traditional Chinese medicines prepared at residents' families is increasingly higher than western medicines year by year. To make it clear, both pre-research and closed questionnaire research were adopted for residents in Chaoyang District, Beijing, excluding residents with a medical background. Based on the results of data, a analysis was made to define the role and influence on the quality of life of residents and give suggestions for relevant departments to improve the traditional Chinese medicine popularization and promote the traditional Chinese medicine market. Copyright© by the Chinese Pharmaceutical Association.

  12. Traditional Chinese Medicine: An Introduction

    Science.gov (United States)

    ... Resources CME/CEU and Online Lectures Online Continuing Education Series Distinguished Lecture Series Integrated Medicine Research Lecture ... TCM, it is important to separate questions about traditional theories and ... of modern science-based medicine and health promotion practices. The ...

  13. The Zulu traditional birth attendant

    African Journals Online (AJOL)

    Some of the important practices of Zulu traditional birth attendants ... the people as regards pregnancy and labour. This article docu- .... into account previous perinatal deaths. ... They were either widows or married to husbands unable to work.

  14. 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)

  15. 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.

  16. Little Eyolf and dramatic tradition

    Directory of Open Access Journals (Sweden)

    Roland Lysell

    2015-02-01

    Full Text Available The article criticises an Ibsen tradition who has seen the last scene of Little Eyolf as a reconciliation. Instead, the article discusses the improbability of a happy marriage characterised by social engagement. The play is open but it is hardly probable that Rita, with her erotic desire, and Allmers, whose desire has turned into metaphysics, can be happy together. The arguments refer to inner criteria and the constantly present dramatic tradition.

  17. TRADITIONAL PHYSICAL CULTURE OF BELARUSIANS

    OpenAIRE

    Shamak, Ales

    2017-01-01

    Relevance. The study of the history of physical culture makes it possible to reveal the laws of its development, the relationship with socio-political and economic factors. The aim of the research is to substantiate the essence, types and structure of the traditional physical culture of Belarusians. Results of the Research. Traditional physical culture has been the main type of physical culture of the Belarusian people for about a thousand years. It is regarded as the activity of the society ...

  18. Was the Monetarist Tradition Invented?

    OpenAIRE

    George S. Tavlas

    1998-01-01

    In 1969, Harry Johnson charged that Milton Friedman 'invented' a Chicago oral quantity theory tradition, the idea being that in order to launch a monetarist counter-revolution, Friedman needed to establish a linkage with pre-Keynesian orthodoxy. This paper shows that there was a distinct pre-Keynesian Chicago quantity-theory tradition that advocated increased government expenditure during the Great Depression in order to put money directly into circulation. This policy stance distinguished th...

  19. Electronic commerce versus traditional commerce

    OpenAIRE

    Dorin Vicentiu Popescu; Manoela Popescu

    2007-01-01

    The internet represents new opportunities for the traditional companies, including the diversification of the given services and also the promotion of the new ones, which are personalized and attractive and they are possible thanks to the information and communication technologies. According to this, the Internet impact, which has allowed the development of a new form of commerce- the commerce via Internet (which is a component of the electronic commerce), against the traditional global comme...

  20. Chapter 1. Traditional marketing revisited

    OpenAIRE

    Lambin, Jean-Jacques

    2013-01-01

    The objective of this chapter is to review the traditional marketing concept and to analyse its main ambiguities as presented in popular textbooks. The traditional marketing management model placing heavy emphasis of the marketing mix is in fact a supply-driven approach of the market, using the understanding of consumers’ needs to mould demand to the requirements of supply, instead of adapting supply to the expectations of demand. To clarify the true role of marketing, a distinction is made b...

  1. The Living Indian Critical Tradition

    Directory of Open Access Journals (Sweden)

    Vivek Kumar Dwivedi

    2010-11-01

    Full Text Available This paper attempts to establish the identity of something that is often considered to be missing – a living Indian critical tradition. I refer to the tradition that arises out of the work of those Indians who write in English. The chief architects of this tradition are Sri Aurobindo, C.D. Narasimhaiah, Gayatri Chakravorty Spivak and Homi K. Bhabha. It is possible to believe that Indian literary theories derive almost solely from ancient Sanskrit poetics. Or, alternatively, one can be concerned about the sad state of affairs regarding Indian literary theories or criticism in English. There have been scholars who have raised the question of the pathetic state of Indian scholarship in English and have even come up with some positive suggestions. But these scholars are those who are ignorant about the living Indian critical tradition. The significance of the Indian critical tradition lies in the fact that it provides the real focus to the Indian critical scene. Without an awareness of this tradition Indian literary scholarship (which is quite a different thing from Indian literary criticism and theory as it does not have the same impact as the latter two do can easily fail to see who the real Indian literary critics and theorists are.

  2. 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.

  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. 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

  5. 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...

  6. 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

  7. 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)

  8. 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.

  9. 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

  10. 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

  11. 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.

    2014-01-01

    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

  12. 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 ...

  13. 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...

  14. 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.

  15. 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.

  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. 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...

  18. 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

  19. 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.

  20. 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.

  1. The LED monitoring system of the PHOENICS experiment

    International Nuclear Information System (INIS)

    Urban, D.

    1991-07-01

    The PHOENICS experiment at ELSA uses a LED monitoring system to control pulse height and time measurement with scintillation counters. A green LED is mounted at the light guide of each of the 304 involved photomultiplier tubes. The LEDs are driven by fast voltage pulses of 5 ns FWHM width and about 20 V amplitude. Simulation of single events is possible by computer controlled switching of individual LEDs. In order to correct for the temperature dependence of the LED intensity an automatic temperature recording system was coupled to the computer. This monitor system allows to control the pulse height and time measurement with an accuracy of about 2% and 100 ps respectively. (orig.) [de

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. Traditional botanical medicine: an introduction.

    Science.gov (United States)

    Rosenbloom, Richard A; Chaudhary, Jayesh; Castro-Eschenbach, Diane

    2011-01-01

    The role of traditional medicine in the well-being of mankind has certainly journeyed a long way. From an ancient era, in which knowledge was limited to a few traditional healers and dominated by the use of whole plants or crude drugs, the science has gradually evolved into a complete healthcare system with global recognition. Technologic advancements have facilitated traditional science to deliver numerous breakthrough botanicals with potency equivalent to those of conventional drugs. The renewed interest in traditional medicine is mainly attributed to its ability to prevent disease, promote health, and improve quality of life. Despite the support received from public bodies and research organizations, development of botanical medicines continues to be a challenging process. The present article gives a summarized description of the various difficulties encountered in the development and evaluation of botanical drugs, including isolation of active compounds and standardization of plant ingredients. It indicates a future direction of traditional medicine toward evidence-based evaluation of health claims through well-controlled safety and efficacy studies.

  7. 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)

  8. 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.

  9. [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.

  10. 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.

  11. 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

  12. TERMITES ENDANGERED TRADITIONAL MEDICAL PLANTS

    Directory of Open Access Journals (Sweden)

    Syaukani Syaukani

    2014-04-01

    Full Text Available Surveys on traditional medical plants affected by termites have been conducted since June to August 2010 at Ketambe, northern Aceh. Traditional medical plants and their natural habitats were obtained through interviewing local people. Termites were collected by adopted a Standardized Sampling Protocol and final. taxonomic confirmation was done with the help of Termite Research Group (the Natural History Museum, London. About 20 species of medical plants were attacked by termites with various levels. Nine genera and 20 species were collected from various habitats throughout Ketambe, Simpur as well as Gunung Setan villages. Coffe (Coffea arabica, hazelnut (Aleurites moluccana , and areca (Area catechu were among the worse of traditional medical  plant that had been attached by the termites.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Analysis of Traditional Historical Clothing

    DEFF Research Database (Denmark)

    Jensen, Karsten; Schmidt, A. L.; Petersen, A. H.

    2013-01-01

    for establishing a three-dimensional model and the corresponding two-dimensional pattern for items of skin clothing that are not flat. The new method is non-destructive, and also accurate and fast. Furthermore, this paper presents an overview of the more traditional methods of pattern documentation and measurement......A recurrent problem for scholars who investigate traditional and historical clothing is the measuring of items of clothing and subsequent pattern construction. The challenge is to produce exact data without damaging the item. The main focus of this paper is to present a new procedure...

  18. 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

  19. Microbial raw data for UV-C LED disinfection study

    Data.gov (United States)

    U.S. Environmental Protection Agency — 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...

  20. 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.

  1. Light Emitting Diode (LED) circular traffic signal lifetime management system.

    Science.gov (United States)

    2011-02-01

    The objective of this research is to build lifetime curves for red, yellow, and green LED circular traffic signals through 20,000-hr. accelerated stress testing of samples operating under Louisianas environmental conditions.

  2. Laboratory Evaluation of LED T8 Replacement Lamp Products

    Energy Technology Data Exchange (ETDEWEB)

    Richman, Eric E.; Kinzey, Bruce R.; Miller, Naomi J.

    2011-05-23

    A report on a lab setting analysis involving LED lamps intended to directly replace T8 fluorescent lamps (4') showing light output, power, and economic comparisons with other fluorescent options.

  3. 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.

  4. LED Retrofit Kits, TLEDs, and Lighting Controls: An Application Guide

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-03-01

    This document provides guidance for retrofitting existing fluorescent troffers including the LED and associated control options available, the pro/cons and costs/benefits of each option, and agency specific requirements (where applicable).

  5. Assessment of community led total sanitation uptake in rural Kenya

    African Journals Online (AJOL)

    K. N. Ogendo, Bsc, MPH, Living goods Nairobi, Kenya,Ministry of Health, Environmental Health ... led drive to set up pit latrines in rural kenya with an aim of promoting sustainable ... Development and Sustainable Development goals lay.

  6. 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.

  7. Biological Research in Canisters (BRIC) - Light Emitting Diode (LED)

    Science.gov (United States)

    Levine, Howard G.; Caron, Allison

    2016-01-01

    The Biological Research in Canisters - LED (BRIC-LED) is a biological research system that is being designed to complement the capabilities of the existing BRIC-Petri Dish Fixation Unit (PDFU) for the Space Life and Physical Sciences (SLPS) Program. A diverse range of organisms can be supported, including plant seedlings, callus cultures, Caenorhabditis elegans, microbes, and others. In the event of a launch scrub, the entire assembly can be replaced with an identical back-up unit containing freshly loaded specimens.

  8. 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.

  9. 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.

  10. 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.

  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. Appraisal of traditional technologies i

    African Journals Online (AJOL)

    Jobo

    A survey on the production practices and mode of utilization of mumu – a traditional, ready-to-eat Nigerian cereal-based food product - was conducted to be able to provide information that would be used to improve on the processing, nutritional quality and acceptability of the product. 83 % of respondents indicated the use ...

  14. Active Learning versus Traditional Teaching

    Directory of Open Access Journals (Sweden)

    L.A. Azzalis

    2009-05-01

    Full Text Available In traditional teaching most of the class time is spent with the professor lecturing and the students watching and listening. The students work individually, and cooperation is discouraged. On the other hand,  active learning  changes the focus of activity from the teacher to the learners, in which students solve problems, answer questions, formulate questions of their own, discuss, explain, debate during class;  moreover, students work in teams on problems and projects under conditions that assure positive interdependence and individual accountability. Although student-centered methods have repeatedly been shown to be superior to the traditional teacher-centered approach to instruction, the literature regarding the efficacy of various teaching methods is inconclusive. The purpose of this study was to compare the student perceptions of course and instructor effectiveness, course difficulty, and amount learned between the active learning and lecture sections  in Health Sciences´ courses by statistical data from Anhembi Morumbi University. Results indicated significant  difference between active  learning and traditional  teaching. Our conclusions were that strategies promoting  active  learning to  traditional lectures could increase knowledge and understanding.

  15. Individualizing in Traditional Classroom Settings.

    Science.gov (United States)

    Thornell, John G.

    1980-01-01

    Effective individualized instruction depends primarily on the teacher possessing the skills to implement it. Individualization is therefore quite compatible with the traditional self-contained elementary classroom model, but not with its alternative, departmentalization, which allows teachers neither the time flexibility nor the familiarity with…

  16. Waldorf Education: An Innovative Tradition.

    Science.gov (United States)

    Harrington, Sheila

    1993-01-01

    Waldorf Schools represent the largest nonsectarian school movement in the world, shunning fads and technology and relying on the creative gifts of teachers and students. Studies include eurythmy, woodworking, weaving, and traditional academic subjects, and no commercial textbooks are used. Despite teacher/funding shortages, the system continues to…

  17. Traditional Knowledge and Patent Protection

    African Journals Online (AJOL)

    Adam

    intellectual property rights laws. 5 into traditional knowledge areas, in turn, has ... range of innovations in industrial, agricultural, environment and health ... Ministry for the Environment, Nature Conservation and Nuclear Safety 2008 ..... Ghosh 2003 Colum J Asian L 106. 80 ..... Management'" 1998 Mich Law Rev 462-556.

  18. Does Scottish Education Need Traditions?

    Science.gov (United States)

    Paterson, Lindsay

    2009-01-01

    Scottish education was, until quite recently, the conscious product of liberal tradition, of the belief by influential elites that the nation's educational history was strong, coherent, and progressive, a source of economic flexibility, of modernising ideas, and of liberal opportunity. In recent decades, however, it has become fashionable to decry…

  19. Japan between tradition and renewal

    DEFF Research Database (Denmark)

    Greve, Anni

    what is still visible in the cityscapes. Furthermore, according to Greve’s publication “Learning from Tokyo urbanism: The urban sanctuaries”, they will figure out how traditions frame interactions between strangers. Thereby, the tea ceremony serves as an example for spaces in-between public and private...

  20. Traditional Chinese Masks Reveal Customs

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    CHINESE masks are undoubtedly an important component in the worldwide mask culture. Minority nationality masks are a major component of China’s mask culture. Traditional Chinese masks, or nuo, represent a cultural component which originated from religious rites in prehistoric times. Various types of nuo are highly valuable for studies of Chinese customs.

  1. Traditional Literacy and Critical Thinking

    Science.gov (United States)

    Dando, Priscille

    2016-01-01

    How school librarians focus on activating critical thinking through traditional literacy development can proactively set the stage for the deep thinking that occurs in all literacy development. The critical-thinking skills students build while becoming accomplished readers and writers provide the foundation for learning in a variety of…

  2. Goddess Traditions in Tantric Hinduism

    DEFF Research Database (Denmark)

    Hinduism cannot be understood without the Great Goddess and the goddess-orientated Śākta traditions. The Goddess pervades Hinduism at all levels, from aniconic village deities to high-caste pan-Hindu goddesses to esoteric, tantric goddesses. Nevertheless, the highly influential tantric forms...

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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...

  8. 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.

  9. 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

  10. Blending traditional and digital marketing

    Directory of Open Access Journals (Sweden)

    Raluca Dania TODOR

    2016-07-01

    Full Text Available It is a matter of fact that we are in the digital era and internet marketing and social media have a significant impact on the way consumers behave, companies do business and it is a must for companies to adapt to the new reality. Due to the fast evolution of the technology, the continuous increase in demand and supply, the supply chain elongation and the big amount of date, the only solution to face the major changes is the automation of all the processes. But even though the new era of communication is here, specialist suggest that companies should not ignore traditional methods, and to try to blend digital marketing with traditional campaigns in order to achieve their goals.

  11. Trust and Traditions in Transitions

    DEFF Research Database (Denmark)

    McQuaid, Sara Dybris

    On New Year’s Eve 2013, months of talks on ‘Dealing with the past’, ‘Flags’ and ‘Parades’ ended without agreement on how to move towards a reconciliation of positions in Northern Ireland. The failure of the talks illustrates the importance of culture and (mis)trust in divided societies, where...... politics often pivot around whose culture shall be official and whose subordinated, whose history shall be remembered and whose forgotten (Jordan and Weedon 1995). These struggles are particularly intense in times of transition where traditions, power relations and frames of relevant remembrance...... are reconfigured. Historically, parading traditions have been important cultural carriers of identity in Northern Ireland. (Jarman 1997). Correspondingly, the marching season has been an arena for politico-cultural struggles and resistance, indexing relations of trust between communities, between society...

  12. [Hygiene between tradition and implementation].

    Science.gov (United States)

    Hansis, M L

    2004-04-01

    The basis of evidence for hygiene rules implemented in hospitals is traditionally small. This is not only because there is little theoretical knowledge on the reciprocal influence between a single hygienic mistake/a single microbial input and the manifestation of a nosocomial infection. There are also not enough clinical studies, especially on complex hygiene questions, to determine whether special measures (e.g., septic rooms)can compensate for deficits in hygiene practice. Furthermore, it would be necessary to designate security buffers distinctly. In-house traditions are able to stabilize hygienic behavior in an excellent manner. They should be fostered and not disparaged as myths. Discussions of experts should not be conducted in public; that is disastrous for the everyday work of physicians in hospitals.

  13. Insomnia in Iranian Traditional Medicine

    OpenAIRE

    Feyzabadi, Zohre; Jafari, Farhad; Feizabadi, Parvin Sadat; Ashayeri, Hassan; Esfahani, Mohammad Mahdi; Badiee Aval, Shapour

    2014-01-01

    Context: Insomnia is one of the most prevalent sleep disorders characterized by sleep difficulty that impairs daily functioning and reduces quality of life. The burden of medical, psychiatric, interpersonal, and societal consequences of insomnia expresses the importance of diagnosing and treatment of insomnia. The aim of study was to investigate causes of insomnia from the viewpoint of Iranian traditional medicine. Evidence Acquisition: In this review study, we searched insomnia in a few of t...

  14. Mangghuer Embroidery: A Vanishing Tradition

    OpenAIRE

    Aila Pullinen

    2015-01-01

    Aila Pullinen. 2015. Mangghuer Embroidery: A Vanishing Tradition IN Gerald Roche and CK Stuart (eds) Asian Highlands Perspectives 36: Mapping the Monguor, 178-188, 301-332. Visits were undertaken in the years 2001 and 2002 to Minhe Hui and Mangghuer (Tu) Autonomous County, Haidong Municipality, Qinghai Province, China to research and document Mangghuer embroidery. This research is summarized in terms of the history of Mangghuer embroidery, tools and materials, embroidery techniques, embr...

  15. 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.

  16. 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.)

  17. 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.)

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Insomnia in Iranian Traditional Medicine

    Science.gov (United States)

    Feyzabadi, Zohre; Jafari, Farhad; Feizabadi, Parvin Sadat; Ashayeri, Hassan; Esfahani, Mohammad Mahdi; Badiee Aval, Shapour

    2014-01-01

    Context: Insomnia is one of the most prevalent sleep disorders characterized by sleep difficulty that impairs daily functioning and reduces quality of life. The burden of medical, psychiatric, interpersonal, and societal consequences of insomnia expresses the importance of diagnosing and treatment of insomnia. The aim of study was to investigate causes of insomnia from the viewpoint of Iranian traditional medicine. Evidence Acquisition: In this review study, we searched insomnia in a few of the most famous ancient textbooks of Iranian traditional medicine from different centuries. This books includeThe Canon of Medicine by Avicenna (the first version of Beirut), Zakhire Kharazmshahi by Jurjani (the scanned version of Bonyade Farhang-e Iran), Malfaregh by Razes (the first version of Iran University of Medical Sciences), and Aqili’s cure by Aqili (the first version of Iran University of Medical Sciences). Results: This study found that in Iranian traditional medicine manuscripts, insomnia was called sahar and even though many factors induce insomnia, most of them act through causing brain dystemperament. Conclusions: The brain dystemperament is considered one of the main causes of insomnia and insomnia can be well managed with an organized line of treatment, by correcting the brain dystemperament through elimination of causes. This study helps to find new solutions to treat insomnia. PMID:24829786

  6. Health traditions of Sikkim Himalaya

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Panda

    2010-01-01

    Full Text Available Ancient medical systems are still prevalent in Sikkim, popularly nurtured by Buddhist groups using the traditional Tibetan pharmacopoeia overlapping with Ayurvedic medicine. Traditional medical practices and their associated cultural values are based round Sikkim′s three major communities, Lepcha, Bhutia and Nepalis. In this study, a semi-structured questionnaire was prepared for folk healers covering age and sex, educational qualification, source of knowledge, types of practices, experience and generation of practice, and transformation of knowledge. These were administered to forty-eight folk healers identified in different parts of Sikkim. 490 medicinal plants find their habitats in Sikkim because of its large variations in altitude and climate. For 31 commonly used by these folk healers, we present botanical name, family, local name, distribution, and parts used, together with their therapeutic uses, mostly Rheumatoid arthritis, Gout, Gonorrhea, Fever, Viral flu, asthma, Cough and Cold, indigestion, Jaundice etc. A case treated by a folk healer is also recounted. This study indicates that, in the studied area, Sikkim′s health traditions and folk practices are declining due to shifts in socio-economic patterns, and unwillingness of the younger generation to adopt folk healing as a profession.

  7. 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.

  8. 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.

  9. 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

  10. Evaluation of OLED and edge-lit LED lighting panels

    Science.gov (United States)

    Mou, Xi; Narendran, Nadarajah; Zhu, Yiting; Freyssinier, Jean Paul

    2016-09-01

    Solid-state lighting (SSL) offers a new technology platform for lighting designers and end-users to illuminate spaces with low energy demand. Two types of SSL sources include organic light-emitting diodes (OLEDs) and light-emitting diodes (LEDs). OLED is an area light source, and its primary competing technology is the edge-lit LED panel. Generally, both of these technologies are considered similar in shape and appearance, but there is little understanding of how people perceive discomfort glare from large area light sources. The objective of this study was to evaluate discomfort glare for the two lighting technologies under similar operating conditions by gathering observers' reactions. The human factors study results showed no statistically significant difference in human response to discomfort glare between OLED and edge-lit LED panels when the two light sources produced the same lighting stimulus. This means both technologies appeared equally glary beyond a certain luminance.

  11. 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.

  12. LED radiation: possible photobiological risks and safety regulations. Pt. 2

    International Nuclear Information System (INIS)

    Horak, W.

    2008-01-01

    With all due euphoria regarding the new illumination possibilities, one can quite often observe a certain degree of uncertainty concerning eye hazard issues in conjunction with intense LED radiation. Moreover, the related general requirements for product- as well as for workplace-safety are rather new. Thus, the possible hazards by the optical radiation of LEDs will be analyzed in this two-port contribution. Part 1 aims to provide a review of these hazards as well as of the bases for their evaluation. The impact of these requirements on state-of-the-art LEDs will be examined in part 2. Compared with conventional light sources, it turns out that there are hardly any differences in this respect. (orig.)

  13. Spot fat reduction by red and near infrared LED phototherapy

    Science.gov (United States)

    Lim, Sungkyoo; Park, Eal-Whan

    2018-02-01

    Low level light therapy (LLLT) using light from red and near infrared LEDs or Lasers have been reported effective as noninvasive methods for reducing spot fat. A total of 55 subjects were randomly divided into test groups and control groups for abdominal fat reduction clinical trial using red and near infrared LED phototherapy devices. Red and near infrared light with irradiance of 10 mW/cm2 were irradiated over the abdominal area to the test group for 30 minutes followed by 30 minutes of aerobic exercise, 3 times a week for 4 weeks. Control group used sham devices for 30 minutes and followed by 30 minutes of aerobic exercise. It is expected that red and near infrared LED phototherapy combined with aerobic exercise would be effective and safe for abdominal fat reduction without any side effects.

  14. A thermosyphon heat pipe cooler for high power LEDs cooling

    Science.gov (United States)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

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

    DEFF Research Database (Denmark)

    Iversen, Ole Sejer; Leong, Tuck Wah

    2012-01-01

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

  16. 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...

  17. 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.

  18. 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.

  19. 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...

  20. LED and Semiconductor Photo-effects on Living Things

    Science.gov (United States)

    Fujiyasu, Hiroshi; Ishigaki, Takemitsu; Fujiyasu, Kentarou; Ujihara, Shirou; Watanabe, Naoharu; Sunayama, Shunji; Ikoma, Shuuji

    We have studied LED irradiation effects on plants and animals in the visible to UV region of light from GaN LEDs. The results are as follows. Blue light considers to be effective for pearl cultivation or for attraction of small fishes living in near the surface of sea such as Pompano or Sardine, white light radiation is effective for cultivation of botanical plankton for shells. Other experiments of UV light irradiation attracting effect on baby sea turtle and the germination UV effect of mushroom, green light weight enhance effect on baby pigs, light vernalization effect of vegitable and Ge far infrared therapic effect on human body are also given.

  1. Determination of organic compounds in water using ultraviolet LED

    Science.gov (United States)

    Kim, Chihoon; Ji, Taeksoo; Eom, Joo Beom

    2018-04-01

    This paper describes a method of detecting organic compounds in water using an ultraviolet LED (280 nm) spectroscopy system and a photodetector. The LED spectroscopy system showed a high correlation between the concentration of the prepared potassium hydrogen phthalate and that calculated by multiple linear regression, indicating an adjusted coefficient of determination ranging from 0.953-0.993. In addition, a comparison between the performance of the spectroscopy system and the total organic carbon analyzer indicated that the difference in concentration was small. Based on the close correlation between the spectroscopy and photodetector absorbance values, organic measurement with a photodetector could be configured for monitoring.

  2. 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.

  3. 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...

  4. 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

  5. Problematic fine bore nasogastric intubation: A radiographer led service development

    International Nuclear Information System (INIS)

    Law, Robert

    2008-01-01

    Developing from the intubation and performing of small bowel enteroclysis a consultant radiographer led service expanded to include problematic gastric, enteric and colonic intubations for diagnostic, therapeutic and interventional purposes. The radiographer led service has also extended to include 'hot reporting' chest images taken to check siting of ward placed nasogastric tubes as well as resiting those tubes that were misplaced. The service has demonstrated itself to be safe and efficient. It has also proven to be both cost and clinically effective. The protracted discomfort and distress to the patient are reduced by minimizing the delay in correctly relocating misplaced tubes

  6. Pharmacist-led medication review in an acute admissions unit

    DEFF Research Database (Denmark)

    Hansen, Trine Graabæk; Bonnerup, Dorthe Krogsgaard; Kjeldsen, Lene Juel

    2015-01-01

    of principles and methodologies, and the practical procedure is seldom described in detail, which makes reproducing study findings difficult. The objective of this paper is to provide a detailed description of a procedure developed and used for pharmacist-led medication review in acute admissions units......) collection of information about the patient's medical treatment, (3) patient interview, (4) critical examination of the patient's medications and (5) recommendations for the hospital physician.Conclusions We have provided a detailed description of a procedure for pharmacist-led medication review. We do so...

  7. Novel Coatings for Enhancement of Light-Emitting Diodes (LEDs)

    Science.gov (United States)

    2006-10-28

    quantum efficiency of LEDs. SAIC’s strength is this area is a proprietary nonimaging optics code. In consultation with Lumileds, SAIC developed designs for...five different optical ele- ments that collect and project light from a LED. The simulations showed that the designs achieve a significant improvement... optical microscope at 100x power the coating is not visible. Fire sample 6DecO4P1 in tube furnace As a first test, sample 6Dec04P1 was progressively

  8. Two phase interleaved buck converter for driving high power LEDs

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2011-01-01

    The goal of this paper is to evaluate an interleaved buck topology for driving high current light-emitting diodes. Low output capacitor value allows the use of non-electrolytic capacitors extending the lifetime of the converter. Converter is operated as a constant, regulated current source which...... increases luminous efficacy of LED compared to PWM dimmed system. Because of the low dynamic resistance of LEDs the duty cycle of the converter does not change greatly with controlled current. By setting the input voltage of the buck converter to around twice the voltage of diode strings, converter can...

  9. 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

  10. Modernism and tradition and the traditions of modernism

    Directory of Open Access Journals (Sweden)

    Kros Džonatan

    2006-01-01

    Full Text Available Conventionally, the story of musical modernism has been told in terms of a catastrophic break with the (tonal past and the search for entirely new techniques and modes of expression suitable to a new age. The resulting notion of a single, linear, modernist mainstream (predicated on the basis of a Schoenbergian model of musical progress has served to conceal a more subtle relationship between past and present. Increasingly, it is being recognized that there exist many modernisms and their various identities are forged from a continual renegotiation between past and present, between tradition(s and the avant-garde. This is especially relevant when attempting to discuss the reception of modernism outside central Europe, where the adoption of (Germanic avant-garde attitudes was often interpreted as being "unpatriotic". The case of Great Britain is examined in detail: Harrison Birtwistle’s opera The Mask of Orpheus (1973–83 forms the focus for a wider discussion of modernism within the context of late/post-modern thought.

  11. 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.

  12. Analysis of traditional Tibetan pills

    Science.gov (United States)

    Cesnek, Martin; Štefánik, Milan; Miglierini, Marcel; Kmječ, Tomáš; Sklenka, L'ubomír

    2017-11-01

    Traditional Tibetan medicine starts to be a very popular complementary medicine in USA and Europe. These pills contain many elements essential for the human body. However, they might also contain heavy metals such as mercury, iron, arsenic, etc. This paper focuses on elemental composition of two Tibetan pills and investigation of forms of iron in them. X-ray fluorescence spectroscopy and neutron activation analysis identified the presence of several heavy metals such as mercury, iron and copper. Mőssbauer spectroscopy revealed the possible presence of α - F e 2 O 3(hematite) and α - F e O O H(goethite) in both of the investigated samples.

  13. Adapting agriculture with traditional knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Swiderska, Krystyna; Reid, Hannah [IIED, London (United Kingdom); Song, Yiching; Li, Jingsong [Centre for Chinese Agriculutral Policy (China); Mutta, Doris [Kenya Forestry Research Institute (Kenya)

    2011-10-15

    Over the coming decades, climate change is likely to pose a major challenge to agriculture; temperatures are rising, rainfall is becoming more variable and extreme weather is becoming a more common event. Researchers and policymakers agree that adapting agriculture to these impacts is a priority for ensuring future food security. Strategies to achieve that in practice tend to focus on modern science. But evidence, both old and new, suggests that the traditional knowledge and crop varieties of indigenous peoples and local communities could prove even more important in adapting agriculture to climate change.

  14. Tree Ordination as Invented Tradition

    Directory of Open Access Journals (Sweden)

    Avery Morrow

    2012-01-01

    Full Text Available The symbolic ordination of trees as monks in Thailand is widely perceived in Western scholarship to be proof of the power of Buddhism to spur ecological thought. However, a closer analysis of tree ordination demonstrates that it is not primarily about Buddhist teaching, but rather is an invented tradition based on the sanctity of Thai Buddhist symbols as well as those of spirit worship and the monarchy. Tree ordinations performed by non-Buddhist minorities in Thailand do not demonstrate a religious commitment but rather a political one.

  15. 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 ...

  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. Performance of LED fluorescence microscopy for the detection of ...

    African Journals Online (AJOL)

    Introduction: Ziehl-Neelsen (ZN) bright-field microscopy is time-consuming, with poor sensitivity, even under optimal conditions. Introduction of Primo Star iLED fluorescent microscopy (FM) may improve TB case finding at referral hospitals in Rwanda. The study aimed to determine the acceptability and effectiveness of iLED ...

  18. Patient safety in midwifery-led care in the Netherlands

    NARCIS (Netherlands)

    Martijn, L.L.M.; Jacobs, A.J.E.; Maassen, I.I.M.; Buitendijk, S.S.E.; Wensing, M.M.

    2013-01-01

    Objective: to describe the incidence and characteristics of patient safety incidents in midwifery-led care for low-risk pregnant women. Design: multi-method study. Setting: 20 midwifery practices in the Netherlands; 1,000 patient records. Population: low-risk pregnant women. Methods: prospective

  19. Effectiveness of a Volunteer-Led Crafts Group Intervention amongst ...

    African Journals Online (AJOL)

    The purpose of this study was to determine the effectiveness of a volunteer led crafts group intervention (VLCG) as an adjunct to antidepressant medication on mild to moderately depressed women. A quasi-experimental, non-equivalent, control group study was conducted in an urban, psychiatric clinic. Depression was ...

  20. Effect of Laser and LED on Enzymatic Production of Ceramide

    DEFF Research Database (Denmark)

    Hongyu, Zhang; Zhang, Long; Tidemand-Lichtenberg, Peter

    2011-01-01

    using HPTLC (high performance thin-layer chromatography) at 0.5, 1, 2, 3, 4, 6, 17, 24 h after irradiation. The duration of effect was evaluated from the experimental data. The results show that enzyme activity can be increased by using both laser and LED sources whose wavelength is located within...

  1. Bright infrared LEDs based on colloidal quantum-dots

    KAUST Repository

    Sun, Liangfeng; Choi, Joshua J.; Stachnik, David; Bartnik, Adam C.; Hyun, Byung-Ryool; Malliaras, George G.; Hanrath, Tobias; Wise, Frank W.

    2013-01-01

    Record-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm. © 2013 Materials Research Society.

  2. Teacher-Led Design of an Adaptive Learning Environment

    Science.gov (United States)

    Mavroudi, Anna; Hadzilacos, Thanasis; Kalles, Dimitris; Gregoriades, Andreas

    2016-01-01

    This paper discusses a requirements engineering process that exemplifies teacher-led design in the case of an envisioned system for adaptive learning. Such a design poses various challenges and still remains an open research issue in the field of adaptive learning. Starting from a scenario-based elicitation method, the whole process was highly…

  3. New insights into consumer-led food product development

    NARCIS (Netherlands)

    Costa, A.I.A.; Jongen, W.M.F.

    2006-01-01

    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

  4. Kattuvad hääled / Reet Varblane

    Index Scriptorium Estoniae

    Varblane, Reet, 1952-

    2008-01-01

    Iisraeli ja palestiina kunstnike näitus "Kattuvad hääled/Overlapping Voices" Essli muuseumis Klosterneuburgis Austrias 16. V-25. X. Kuraatorid: Tal Adler (Iisrael, juut), Amal Murkus (Iisrael, palestiinlane), Karin Schneider ja Friedemann Derschmidt (Austria). Karlheinz ja Agnes Esslile kuuluvast eramuuseumist (1991, arhitekt Heinz Tesar)

  5. 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.

  6. Stuurlicht bij anjer - Consultancy: Vergelijking van LED lampen en gloeilampen

    NARCIS (Netherlands)

    Helm, van der F.P.M.

    2013-01-01

    Als gevolg van nieuwe wetgeving zullen gloeilampen vervangen moeten worden. De kwekers moeten nu kiezen tussen de alternatieven; LED lampen of spaarlampen. In een onderzoek in de praktijk in 2012 zijn op twee bedrijven proeven aangelegd. Op 1 bedrijf bij 2 rassen en op een ander bedrijf met 2

  7. InGaN/GaN Nanowire LEDs and Lasers

    KAUST Repository

    Zhao, Chao; Ng, Tien Khee; Jahangir, Shafat; Frost, Thomas; Bhattacharya, Pallab; Ooi, Boon S.

    2016-01-01

    -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

  8. Refugee-led humanitarianism in Lebanon’s Shatila camp

    Directory of Open Access Journals (Sweden)

    Hind Sharif

    2018-02-01

    Full Text Available Refugee-led humanitarian initiatives by ‘established’ Palestinian refugees in response to the arrival of ‘new’ displaced Syrians to Shatila camp raise key questions about the limitations of the humanitarian system and representations of refugees as passive victims.

  9. The effect of LED illumination on endodontic biofilms

    DEFF Research Database (Denmark)

    Markvart, Merete

    Within endodontics photodynamic therapy (PDT) has been suggested as a disinfectant procedure during root canal treatment. A photoactive dye (photosensitizer), methylene blue or toluidine blue, are activated by a light source, usually lasers or light emitting diodes (LEDs), thereby forming free...

  10. 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.

  11. Nurse-led rehabilitation after gynaecological cancer surgery

    DEFF Research Database (Denmark)

    Seibæk, Lene

    2009-01-01

      Abstract This article presents the preliminary results and experiences from an ongoing study aiming to: Develop and test a nurse-led multidisciplinary rehabilitation programme for women who undergo surgery for localised gynaecological cancers.Evaluate the effect of the programme prospectively o...

  12. LED Light to improve Strawberry Flavour, Quality and Production

    NARCIS (Netherlands)

    Hanenberg, M.A.A.; Janse, J.; Verkerke, W.

    2016-01-01

    A current demonstration in the greenhouses of Wageningen UR in Bleiswijk (the Netherlands) shows positive results of LED light on the quality and production of strawberries (Fragaria x ananassa). In this demonstration two strawberry cultivars, Elsanta and Sonata, are exposed to three different light

  13. Students' Perception and Practice of Writing through Peer-led ...

    African Journals Online (AJOL)

    Students' Perception and Practice of Writing through Peer-led Learning (PLL) at Bahir Dar University. ... Science, Technology and Arts Research Journal ... parties to get the maximum benefit from PLTL; that is, the 'one-to-five' group discussion ...

  14. 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.

  15. EC-LEDS Mexico: Advancing Clean Energy Goals

    Energy Technology Data Exchange (ETDEWEB)

    2016-07-01

    EC-LEDS works with the government of Mexico to help meet its goals of reducing greenhouse gas emissions from the energy sector. The program targets specific, highly technical areas where Mexico has indicated the program can add value and make an impact.

  16. High efficiency nitride based phosphores for white LEDs

    NARCIS (Netherlands)

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

    2008-01-01

    In this overview paper, novel rare-earth doped silicon nitride based phosphors for white LEDs applications have been demonstrated. The luminescence properties of orange-red-emitting phosphors (M2Si5N8:Eu2+) and green-to-yellow emitting phosphors (MSi2N2O2:Eu2+, M = Ca, Sr, Ba) are discussed in

  17. 76 FR 14904 - Executive-Led Trade Mission to Afghanistan

    Science.gov (United States)

    2011-03-18

    ... would enhance development of Afghanistan's industrial sector and lead to increased productivity and... business development trade mission to Kabul, Afghanistan in September 2011. This mission will be led by a.... companies explore long-term business opportunities in Afghanistan and enhance U.S.-Afghan commercial...

  18. Geriatric and Student Perceptions following Student-led Educational Sessions

    Directory of Open Access Journals (Sweden)

    Kristin Janzen

    2018-01-01

    Full Text Available Objective: The objective of this study was to measure the effect of student-led educational events on geriatric patient and student participant perceptions in a community setting. Methods: Students led three events at a senior community center, focusing on learning and memory, sleep hygiene, and arthritis pain. The participants were geriatric patients who themselves were providers of support to homebound peers (“clients” through an independently organized program. Geriatric participants completed pre- and post-event surveys to measure changes in familiarity with the topics. Student participants also completed pre- and post-event surveys that tracked changes in their comfort in working with the geriatric population. Results: Each event demonstrated at least one positive finding for geriatric patients and/or their clients. Students reported increased comfort in working with and teaching the geriatric population following the first and third events, but not the second. Conclusion: Student-led educational sessions can improve perceived health-related knowledge of geriatric participants while simultaneously exposing students to the geriatric patient population. Overall, both students and geriatric participants benefited from these events. Practice Implications: Incorporation of single, student-led educational events could be mutually beneficial to students and the elderly population in the community and easily incorporated into any healthcare curriculum. Funding:This work was supported by a Butler University Innovation Fund Grant. Treatment of Human Subjects: IRB review/approval required and obtained   Type: Original Research

  19. Multiple Primary LED Lamp Colour Controller with Inherent Brightness Limitation

    NARCIS (Netherlands)

    Barcena, R.; Ackermann, B.

    2007-01-01

    There is a strong interest in using LEDs for general illumination due to the potential they offer for energy saving, environmental friendliness, new opportunities in lighting design, and control of the intensity, colour, and spatial distribution of light. General illumination requires primarily

  20. High power deep UV-LEDs for analytical optical instrumentation

    Czech Academy of Sciences Publication Activity Database

    Li, Y.; Dvořák, Miloš; Nesterenko, P. N.; Nuchtavorn, N.; Macka, M.

    2018-01-01

    Roč. 255, č. 2 (2018), s. 1238-1243 ISSN 0925-4005 Institutional support: RVO:68081715 Keywords : deep UV Light emitting diodes (LEDs) * optical detection * portable analytical instrumentation Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 5.401, year: 2016

  1. Fluorescent silicon carbide materials for white LEDs and photovoltaics

    DEFF Research Database (Denmark)

    Syväjärvi, Mikael; Ou, Haiyan; Wellmann, Peter

    the luminescence appears in the infrared region in a broad range from 700 to 1100 nm. This potentially can be used to develop an infrared LED for de-icing in wind power and airplanes, or medical applications. Further on, a very efficient solar cell material can be investigated by studying the impurity effect...

  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. Accelerated optical polymer aging studies for LED luminaire applications

    Science.gov (United States)

    Estupiñán, Edgar; Wendling, Peter; Kostrun, Marijan; Garner, Richard

    2013-09-01

    There is a need in the lighting industry to design and implement accelerated aging methods that accurately simulate the aging process of LED luminaire components. In response to this need, we have built a flexible and reliable system to study the aging characteristics of optical polymer materials, and we have employed it to study a commercially available LED luminaire diffuser made of PMMA. The experimental system consists of a "Blue LED Emitter" and a working surface. Both the temperatures of the samples and the optical powers of the LEDs are appropriately characterized in the system. Several accelerated aging experiments are carried out at different temperatures and optical powers over a 90 hour period and the measured transmission values are used as inputs to a degradation model derived using plausibility arguments. This model seems capable of predicting the behavior of the material as a function of time, temperature and optical power. The model satisfactorily predicts the measured transmission values of diffusers aged in luminaires at two different times and thus can be used to make application recommendations for this material. Specifically, at 35000 hours (the manufacturer's stated life of the luminaire) and at the typical operational temperature of the diffuser, the model predicts a transmission loss of only a few percent over the original transmission of the material at 450 nm, which renders this material suitable for this application.

  4. Harmonics Study of Common Low Wattage LED Lamps

    Directory of Open Access Journals (Sweden)

    Ioan Dragoş Deaconu

    2017-11-01

    Full Text Available This article presents experimental data on Light Emitting Diode (LED lamps of low wattage that are commonly found both in commercial and residential applications. A comparison with the existing regulations is performed. The measurements are performed using power and energy quality analyzer intended also for avionic and military systems.

  5. Occupancy-based illumination control of LED lighting systems

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  7. LED's in Physics Demos: A Handful of Examples.

    Science.gov (United States)

    Lottis, Dan; Jaeger, Herbert

    1996-01-01

    Describes the use of light-emitting diodes (LED) instead of incandescent bulbs in experiments that generally use battery and bulbs to enable students to explore and understand fundamental electrical phenomena. Presents the following examples: Faraday's Law demonstration, conductors and insulators, and rectifying action of a diode. (JRH)

  8. Current-voltage model of LED light sources

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Munk-Nielsen, Stig

    2012-01-01

    Amplitude modulation is rarely used for dimming light-emitting diodes in polychromatic luminaires due to big color shifts caused by varying magnitude of LED driving current and nonlinear relationship between intensity of a diode and driving current. Current-voltage empirical model of light...

  9. Optical and thermal simulation chain for LED package

    NARCIS (Netherlands)

    Tapaninen, O.; Myohanen, P.; Majanen, M.; Sitomaniemi, A.; Olkkonen, J.; Hildenbrand, V.; Gielen, A.W.J.; Mackenzie, F.V.; Barink, M.; Smilauer, V.; Patzak, B.

    2016-01-01

    This paper presents a test case for coupling two physical aspects of an LED, optical and thermal, using specific simulation models coupled through an open source platform for distributed multi-physics modelling. The glue code for coupling is written with Python programming language including

  10. 76 FR 66692 - Executive-Led Trade Mission to Afghanistan

    Science.gov (United States)

    2011-10-27

    ... business development trade mission to Kabul, Afghanistan in February 2012. This mission will be led by a..., architecture, transportation and logistics, and infrastructure); mining (including equipment, technology, and.... companies explore long-term business opportunities in Afghanistan and enhance U.S.--Afghan commercial...

  11. Thermal simulation and validation of 8W LED lamp

    NARCIS (Netherlands)

    Jakovenko, J.; Werkhoven, R.J.; Formánek, J.; Kunen, J.M.G.; Bolt, P.J.; Kulha, P.

    2011-01-01

    This work deals with thermal simulation and characterization of solid state lightening (SSL) LED Lamp in order to get precise 3D thermal models for further lamp thermal optimization. Simulations are performed with ANSYS-CFX and CoventorWare software tools. The simulated thermal distribution has been

  12. 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

  13. 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.

  14. Health risks occurring when color is percepted under led lighting

    Directory of Open Access Journals (Sweden)

    V.A. Kaptsov

    2017-06-01

    Full Text Available The article deals with problems of color perception under LED lighting. We revealed that inadequate perception of a signal color by a driver led to greater risks of transport accidents. We reviewed both Jung-Helmholtz three-color hypothesis and a modern one based on fiber-optical approach to functioning of "Mueller cells and cones" system. We made an attempt to explain a number of effects related to visibility curves and time delays when defining color of light signals. Our research on assessing influence exerted by LED lighting on functional state and working capacity of railway workers during which we applied occupational selection techniques revealed negative changes. We proved there was a decrease in functional resistance to color sense between red and green signals as well as longer response time for complicated sight-motor reaction and significant decrease in readiness to emergency actions (resistance to monotony in examined individuals. The article also contains data on time peculiarities which are characteristic for defining signals color in relation to red signal (650 nm. We showed that when red color LEDs with wave length much shorter than 650 nm were used in signaling devices it caused risks of inadequate color detection, longer reaction to inhibiting signals, and greater possibility of transport accidents and negative events in everyday life. These peculiarities should be taken into account when designing traffic lights and other signaling devices which provide transport safety. We also proved that signaling traffic lights for transport systems should be designed allowing for physiology of color perception by a human visual analyzer; application of LEDs with wave length shorter than 650 nm should be absolutely excluded

  15. Radiopasteurization of traditional herbal medicine

    Energy Technology Data Exchange (ETDEWEB)

    Hilmy, N; Suryasaputra, C [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1981-04-01

    Investigation on the effects of irradiation using pasteurization dose of 500 krad (5kGy) on microbes contaminating traditional herbal medicine, produced by 3 large manufacturers in Indonesia, was carried out. Storage effects on microbial count moisture content of traditional herbal medicine packed in microbe tight packages, were also observed. The results showed that initial bacterial counts varied between 10/sup 4/ and 10/sup 8/ per gram, and mould and yeast counts varied between 0 and 10/sup 5/ per gram. These numbers decreased as much as 2 to 5 log cycles after irradiation with 500 krad. After 6 month storage, bacterial counts of irradiated samples decreased as much as 0 to 10/sup 3/ per gram. Initial moisture content varied from 5 to 12% and after 6 month storage the moisture content of most samples increased as much as 0 to 5%. Irradiated samples were found to be mould free, and most of the surviving microbes consisted of spore forming aerobic bacteria and yeast.

  16. Radiopasteurization of traditional herbal medicine

    International Nuclear Information System (INIS)

    Hilmy, Nazly; Suryasaputra, C.

    1981-01-01

    Investigation on the effects of irradiation using pasteurization dose of 500 krad (5kGy) on microbes contaminating traditional herbal medicine, produced by 3 large manufacturers in Indonesia, was carried out. Storage effects on microbial count moisture content of traditional herbal medicine packed in microbe tight packages, were also observed. The results showed that initial bacterial counts varied between 10 4 and 10 8 per gram, and mould and yeast counts varied between 0 and 10 5 per gram. These numbers decreased as much as 2 to 5 log cycles after irradiation with 500 krad. After 6 month storage, bacterial counts of irradiated samples decreased as much as 0 to 10 3 per gram. Initial moisture content varied from 5 to 12% and after 6 month storage the moisture content of most samples increased as much as 0 to 5%. Irradiated samples were found to be mould free, and most of the surviving microbes consisted of spore forming aerobic bacteria and yeast. (author)

  17. Digesters in traditional Persian medicine

    Science.gov (United States)

    Mahmoudpour, Zeinab; Shirafkan, Hoda; Mojahedi, Morteza; Gorji, Narjes; Mozaffarpur, Seyyed Ali

    2018-01-01

    Background: Functional gastrointestinal diseases are common in general populations and comprise more than 40% visits to gastroenterologists. Treatment options of gastrointestinal diseases have been limited. There are a few medications for functional gastrointestinal diseases and some of medications are not available in the market or in the place where the patient lives. Traditional Persian medicine (TPM) is a branch of alternative and traditional medicine based on individual viewpoint and humoral theory, focuses on lifestyle modification and uses natural products to manage the patients. Methods: In this study, a set of compound drugs known as digesters (jawarishes) and other applications are described based on main TPM text books. Results: Jawarishes have different formulations containing various medicinal herbs used for better food digestion and improved gastric functions and also used for other disorders including reinforcing the brain, heart, liver and some therapeutic approaches. Conclusions: By reviewing medieval Persian pharmaceutical manuscripts, we can conclude that many herbs are effective in different systems of the body and improve gastric functions. Zingiber officinalis and Piper nigrum are mixed together to get various formulations. The variety of jawarishes formulations and their different clinical applications can indicate continuity of their use. PMID:29387312

  18. TRADITIONAL FERMENTED FOODS OF LESOTHO

    Directory of Open Access Journals (Sweden)

    Tendekayi H. Gadaga

    2013-06-01

    Full Text Available This paper describes the traditional methods of preparing fermented foods and beverages of Lesotho. Information on the preparation methods was obtained through a combination of literature review and face to face interviews with respondents from Roma in Lesotho. An unstructured questionnaire was used to capture information on the processes, raw materials and utensils used. Four products; motoho (a fermented porridge, Sesotho (a sorghum based alcoholic beverage, hopose (sorghum fermented beer with added hops and mafi (spontaneously fermented milk, were found to be the main fermented foods prepared and consumed at household level in Lesotho. Motoho is a thin gruel, popular as refreshing beverage as well as a weaning food. Sesotho is sorghum based alcoholic beverage prepared for household consumption as well as for sale. It is consumed in the actively fermenting state. Mafi is the name given to spontaneously fermented milk with a thick consistency. Little research has been done on the technological aspects, including the microbiological and biochemical characteristics of fermented foods in Lesotho. Some of the traditional aspects of the preparation methods, such as use of earthenware pots, are being replaced, and modern equipment including plastic utensils are being used. There is need for further systematic studies on the microbiological and biochemical characteristics of these these products.

  19. 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.

  20. 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.

  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. 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.

  3. 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.

  4. 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.

  5. 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

  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. 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…

  8. 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.

  9. Traditional Procurement is too Slow

    Directory of Open Access Journals (Sweden)

    Ann Kong

    2012-11-01

    Full Text Available This paper reports on an exploratory interview survey of construction project participants aimed at identifying the reasons for the decrease in use of the traditional, lump-sum, procurement system in Malaysia. The results show that most people believe it is too slow. This appears to be in part due to the contiguous nature of the various phase and stages of the process and especially the separation of the design and construction phases. The delays caused by disputes between the various parties are also seen as a contributory factor - the most prominent cause being the frequency of variations, with design and scope changes being a particular source of discontent. It is concluded that an up scaling of the whole of the time related reward/penalty system may be the most appropriate measure for the practice in future.

  10. Neymar, defender of brazilian tradition

    Directory of Open Access Journals (Sweden)

    Francisca Islandia Cardoso da Silva

    2016-09-01

    Full Text Available The purpose of this article is to analyze how university students of Teresina-PI appropriate of the message of a report of the television show Esporte Espetacular. There was use of the technique of focus groups and analytical-descriptive method for collecting and analyzing data. The sample consisted of 24 university students, aged between 18 and 24 years. The report features Neymar as responsible to follow the "tradition" of Brazilians and to be crowned as the best player in the world. The subjects of research said that the speech conveyed by the report can reproduce and create a reality sometimes dreamlike, because objective to confer to Neymar great importance with regard to national identity.

  11. 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

  12. 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.

  13. Future Solid State Lighting using LEDs and Diode Lasers

    DEFF Research Database (Denmark)

    Petersen, Paul Michael

    2014-01-01

    applications. Within the coming years, it is expected that the efficiency of blue laser diodes will approach the efficiency of infrared diode lasers. This will enable high efficiency white light generation with very high lumen per watt values. SSL today is mainly based on phosphor converted blue light emitting......Lighting accounts for 20% of all electrical energy usage. Household lighting and commercial lighting such as public and street lighting are responsible for significant greenhouse gas emissions. Therefore, currently many research initiatives focus on the development of new light sources which shows...... significant savings. Solid state lighting (SSL) based on LEDs is today the most efficient light source for generation of high quality white light. Diode lasers, however, have the potential of being more efficient than LEDs for the generation of white light. A major advantage using diode lasers for solid state...

  14. The cinema LED lighting system design based on SCM

    Science.gov (United States)

    En, De; Wang, Xiaobin

    2010-11-01

    A LED lighting system in the modern theater and the corresponding control program is introduced. Studies show that moderate and mutative brightness in the space would attract audiences' attention on the screen easily. SCM controls LED dynamically by outputting PWM pulse in different duty cycle. That cinema dome lights' intensity can vary with the plot changed, make people get a better view of experience. This article expounds the architecture of hardware system in the schedule and the control flow of the host of the solution. Besides, it introduces the design of software as well. At last, the system which is proved energy-saving, reliable, good visual effect and having using value by means of producing a small-scale model, which reproduce the whole system and achieves the desired result.

  15. Measurements of UGR of LED light by a DSLR colorimeter

    Science.gov (United States)

    Hsu, Shau-Wei; Chen, Cheng-Hsien; Jiaan, Yuh-Der

    2012-10-01

    We have developed an image-based measurement method on UGR (unified glare rating) of interior lighting environment. A calibrated DSLR (digital single-lens reflex camera) with an ultra wide-angle lens was used to measure the luminance distribution, by which the corresponding parameters can be automatically calculated. A LED lighting was placed in a room and measured at various positions and directions to study the properties of UGR. The testing results are fitted with visual experiences and UGR principles. To further examine the results, a spectroradiometer and an illuminance meter were respectively used to measure the luminance and illuminance at the same position and orientation of the DSLR. The calculation of UGR by this image-based method may solve the problem of non-uniform luminance-distribution of LED lighting, and was studied on segmentation of the luminance graph for the calculations.

  16. Reported challenges in nurse-led randomised controlled trials

    DEFF Research Database (Denmark)

    Wang Vedelø, Tina; Lomborg, Kirsten

    2011-01-01

    Aims: The purpose of this integrative literature review was to explore and discuss the methodological challenges nurse researchers report after conducting nurse-led randomised controlled trials in clinical hospital settings. Our research questions were (i) what are the most commonly experienced...... and the clinical nursing staff. Two lessons learned from this integrative review can be highlighted. First, we recommend researchers openly to share their experiences of barriers and challenges. They should describe factors that may have inhibited the desired outcome. Second, efforts to improve the collaboration...... between nurse researchers and clinicians, including education, training and support may increase the success rate and quality of nurse-led studies using the randomised controlled trial....

  17. Universal fixture design for body mounted LED lights

    Science.gov (United States)

    Hajra, Debdyut

    2017-09-01

    Today LED headlamps, armbands and ankle-bands, shoe-lights etc. have become very popular. These find extensive use in search and rescue operations, mining, carving, etc. and are also used by individuals during hiking, trekking, running, etc. during dark hours. They serve two main purposes: they provide sufficient illumination in low light conditions and they are used to indicate the presence of a person after dark. These have the same basic requirements. They must produce sufficient light, have high durability, long battery life, must be light weight and energy efficient. This paper discusses possibilities of designing a universal LED fixture can be designed so that it meets the respective needs of everyone irrespective of their background and industry. It discusses the materials to be used for its different body parts, innovative clip design for attachment with support structures like head and armbands, helmets, shoes, etc.

  18. Creativity and Impact of Advertising Electronic Led Billboards in Jakarta

    Directory of Open Access Journals (Sweden)

    Suprayitno Suprayitno

    2016-04-01

    Full Text Available The creativity and the impact of advertising electronic LED billboards in Jakarta was an approach to see, to know and to understand in a deeper way. Creativity decisions affect all advertising, art, and knowledge combined with the phrase creative strategy. Creative advertising ideas must be original, unique, different, new, unexpected and right on target. The approach used was qualitative research methods, including data collection in the form of literature review, interviews with the actors and the surrounding communities, as well as documenting the billboard directly outside the media was located. The results of this research are the analysis report the creativity and impact of LED electronic billboard advertising effectiveness, is expected to produce a more detailed picture. So that students and practitioners can use the visual communication design, process, and maximize the advertising rules in designing a design to reach the stage of design creativity and better application. 

  19. Replacing Lecture with Peer-led Workshops Improves Student Learning

    OpenAIRE

    Preszler, Ralph W.

    2009-01-01

    Peer-facilitated workshops enhanced interactivity in our introductory biology course, which led to increased student engagement and learning. A majority of students preferred attending two lectures and a workshop each week over attending three weekly lectures. In the workshops, students worked in small cooperative groups as they solved challenging problems, evaluated case studies, and participated in activities designed to improve their general learning skills. Students in the workshop versio...

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  1. Using UAVs to Conduct Student-led Research Projects

    Science.gov (United States)

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

    2016-12-01

    Recreational drones can inspire students to initiate research projects. These "toys" have a low cost (Arduino board, SABEL collects temperature, humidity, and GPS position. This presentation will provide examples of student-led investigations, instructions for building the SABEL sensor package, and the status of the new e-book compilation of student-focused activities using recreational drones to pursue science, math, engineering, and technology research investigations.

  2. Measuring progress towards a primary care-led NHS.

    Science.gov (United States)

    Miller, P; Craig, N; Scott, A; Walker, A; Hanlon, P

    1999-07-01

    The push towards a 'primary care-led' National Health Service (NHS) has far-reaching implications for the future structure of the NHS. The policy involves both a growing emphasis on the role of primary care practitioners in the commissioning of health services, and a change from hospital to primary and community settings for a range of services and procedures. Although the terminology has changed, this emphasis remains in the recent Scottish Health Service White Paper and its English counterpart. To consider three questions in relation to this policy goal. First, does the evidence base support the changes? Secondly, what is the scale of the changes that have occurred? Thirdly, what are the barriers to the development of a primary care-led NHS? Programme budgets were compiled to assess changes over time in the balance of NHS resource allocation with respect to primary and secondary care. Total NHS revenue expenditure for the 15 Scottish health boards was grouped into four blocks or 'programmes': primary care, secondary care, community services, and a residual. The study period was 1991/2 to 1995/6. Expenditure data were supplied by the Scottish Office. Ambiguity of definitions and the absence of good data cause methodological difficulties in evaluating the scale and the appropriateness of the shift. The data that are available suggest that, at the aggregate level, there have been changes over time in the balance of resource allocation between care settings: relative investment into primary care has increased. It would appear that this investment is relatively small and from growth money rather than a 'shift' from secondary care. In addition, the impact of GP-led commissioning is variable but limited. General practitioners' (GPs') attitudes to the policy suggest that progress towards a primary care-led NHS will continue to be patchy. The limited shift to date, alongside evidence of ambivalent attitudes to the shift on the part of GPs, suggest that this is a policy

  3. Demonstration Assessment of LED Roadway Lighting: Philadelphia, PA

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P.; Tuenge, Jason R.; Poplawski, Michael E.

    2012-09-01

    For this demonstration assessment, 10 different groups of LED luminaires were installed at three sites in Philadelphia, PA. Each of the three sites represented a different set of conditions, most importantly with regard to the incumbent HPS luminaires, which were nominally 100 W, 150 W, and 250 W. The performance of each product was evaluated based on manufacturer data, illuminance calculations, field measurements of illuminance, and the subjective impressions of both regular and expert observers.

  4. Garden's lighting by led-luminaries supplied by photovoltaic

    International Nuclear Information System (INIS)

    Vasilev, H.; Angelov, A.; Ganchev, G.

    2006-01-01

    The implementation of the project by investment entirely of Denima 2001 Ltd. for garden illumination of the part of the public garden 'Studentski' is consider. The illumination installation is implemented by PV batteries and by luminaries made up by fluorescent laps and LED. The goals of this pilot project are to make a comparative analyses and observation for the operation of the light system for future development

  5. Export-led growth hypothesis : new evidence from Thirlwall's idea

    OpenAIRE

    Chee-Keong Choong; Zulkornain Yusop; Siong-Hook Law

    2007-01-01

    This study reexamines the relationship between exports and economic growth in ten East Asian and Pacific economies by building upon Verdoorn's [1941] idea. The cointegration tests indicate the existence of long-run and stable relationships between economic growth, exports, imports, capital, and labor in each economy. Granger-causality tests indicate short-run in causality (either export-led growth or growth-driven exports) in most economies. Besides, among the long-run estimated coefficients ...

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Traditional perception of Greeks in Serbian oral tradition

    Directory of Open Access Journals (Sweden)

    Konjik Ivana

    2006-01-01

    Full Text Available Based on material on Greeks from Vuk’s corpus of epic poems, we discuss the construction of ethnic stereotype of Greeks in Serbian language. However, the limitation of the paper’s possible conclusion lies in the nature of the corpus: Vuk had deliberately chosen one material over another, therefore, the corpus relating to Greeks cannot be considered as representative of the whole Serbian folk poems. Therefore, the discussion is limited to certain elements of the stereotype. Nevertheless, these Serbian epic folk poems contain many layers: historical, geographical, sociological, mythological and so on, with a strong foundation in traditional culture; thus, they provide an insight into geo-political situation of the time period, viewpoints, perspectives and experiences of other ethnic groups that Serbs have been into contact with. In particular, the relationship toward Greeks was marked with pronounced patriarchal attitude concerning others: we-others, ours-foreign, good-bad. In this sense, Greeks are portrayed as foreign, and as such, as a potential source of danger. On the other hand, Greeks are Christian Orthodox, which associates them with the category ours. In socio-economic sense, they were traders and wealthy, respected gentlemen. In epical-heroic profile, they were not considered as great heroes, but as "lousy army", and frequently, as unfaithful.

  11. High Efficacy Green LEDs by Polarization Controlled MOVPE

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Christian [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2013-03-31

    Amazing performance in GaInN/GaN based LEDs has become possible by advanced epitaxial growth on a wide variety of substrates over the last decade. An immediate push towards product development and worldwide competition for market share have effectively reduced production cost and generated substantial primary energy savings on a worldwide scale. At all times of the development, this economic pressure forced very fundamental decisions that would shape huge industrial investment. One of those major aspects is the choice of epitaxial growth substrate. The natural questions are to what extend a decision for a certain substrate will limit the ultimate performance and to what extent, the choice of a currently more expensive substrate such as native GaN could overcome any of the remaining performance limitations. Therefore, this project has set out to explore what performance characteristic could be achieved under the utilization of bulk GaN substrate. Our work was guided by the hypotheses that line defects such as threading dislocations in the active region should be avoided and the huge piezoelectric polarization needs to be attenuated – if not turned off – for higher performing LEDs, particularly in the longer wavelength green and deep green portions of the visible spectrum. At their relatively lower performance level, deep green LEDs are a stronger indicator of relative performance improvements and seem particular sensitive to the challenges at hand.

  12. UV-LED-based charge control for LISA

    Science.gov (United States)

    Olatunde, Taiwo; Shelley, Ryan; Chilton, Andrew; Ciani, Giacomo; Mueller, Guido; Conklin, John

    2014-03-01

    The test masses inside the LISA gravitational reference sensors (GRS) must maintain almost pure geodesic motion for gravitational waves to be successfully detected. The residual accelerations have to stay below 3fm/s2/rtHz at all frequencies between 0.1 and 3 mHz. One of the well known noise sources is associated with the charges on the test masses which couple to stray electrical potentials and external electro-magnetic fields. The LISA pathfinder (LPF) will use Hg-discharge lamps emitting mostly around 253 nm to discharge the test masses via photoemission in its 2015/16 flight. A future LISA mission launched around 2030 will likely replace the lamps with newer UV-LEDs. UV-LEDs have a lower mass, a better power efficiency, and are smaller than their Hg counterparts. Furthermore, the latest generation produces light at 240 nm, with energy well above the work function of pure gold. I will describe a preliminary design for effective charge control through photoelectric effect by using these LEDs. The effectiveness of this method is verified by taking Quantum Efficiency (QE) measurements which relate the number of electrons emitted to the number of photons incident on the Au test mass surface. This presentation addresses our initial results and future plans which includes implementation and testing in the UF torsion pendulum and space-qualification in a small satellite mission which will launch in the summer of 2014, through a collaboration with Stanford, KACST, and NASA Ames Research Center.

  13. 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.

  14. Monolayer graphene dispersion and radiative cooling for high power LED

    Science.gov (United States)

    Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

    2013-10-01

    Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1 ° C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation.

  15. Monolayer graphene dispersion and radiative cooling for high power LED

    International Nuclear Information System (INIS)

    Hsiao, Tun-Jen; Eyassu, Tsehaye; Henderson, Kimberly; Kim, Taesam; Lin, Chhiu-Tsu

    2013-01-01

    Molecular fan, a radiative cooling by thin film, has been developed and its application for compact electronic devices has been evaluated. The enhanced surface emissivity and heat dissipation efficiency of the molecular fan coating are shown to correlate with the quantization of lattice modes in active nanomaterials. The highly quantized G and 2D bands in graphene are achieved by our dispersion technique, and then incorporated in an organic-inorganic acrylate emulsion to form a coating assembly on heat sinks (for LED and CPU). This water-based dielectric layer coating has been formulated and applied on metal core printed circuit boards. The heat dissipation efficiency and breakdown voltage are evaluated by a temperature-monitoring system and a high-voltage breakdown tester. The molecular fan coating on heat dissipation units is able to decrease the equilibrium junction temperature by 29.1 ° C, while functioning as a dielectric layer with a high breakdown voltage (>5 kV). The heat dissipation performance of the molecular fan coating applied on LED devices shows that the coated 50 W LED gives an enhanced cooling of 20% at constant light brightness. The schematics of monolayer graphene dispersion, undispersed graphene platelet, and continuous graphene sheet are illustrated and discussed to explain the mechanisms of radiative cooling, radiative/non-radiative, and non-radiative heat re-accumulation. (paper)

  16. The impact of peer-led simulations on student nurses.

    Science.gov (United States)

    Valler-Jones, Tracey

    Simulation within nurse education has been widely accepted as an educational approach. However, this is mainly led by the facilitator with the student maintaining a passive role in the learning. This paper describes a study that was undertaken to analyse the effectiveness of peer-led simulations in the undergraduate nursing programme. A mixed-method approach was used for this study design. This study took place in a simulation suite within a university in the Midlands. Twenty four second-year child branch students were purposively selected to take part. Students designed and facilitated a simulation based on the care of a critically ill child. Formal assessment of the learning was collected via the use of a structured clinical examination. Students completed an evaluation of their perceived confidence and competence levels. There was 100% pass rate in the assessment of students' clinical competence following the simulation. Thematic analysis of the evaluation highlighted the learning achieved by the students, not only of their clinical skills but also their personal development. The use of peer-led simulation promotes new learning and is a valuable educational approach.

  17. 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

  18. Fuselage mounted anti-collision lights utilizing high power LEDs

    Science.gov (United States)

    Lundberg, John; Machi, Nicolo; Mangum, Scott; Singer, Jeffrey

    2005-09-01

    As LEDs continue to improve in efficacy and total light output, they are increasingly finding their way in to new applications in the aviation industry as well as adjacent markets. One function that is particularly challenging and may reap substantial benefits from this new technology is the fuselage mounted anti-collision light. Anti-collision lights provide conspicuity for the aircraft by periodically emitting bright flashes of light. The color, light distribution and intensity levels for these lights are all closely regulated through Federal Aviation Regulation (FAR) documents. These lighting requirements, along with thermal, environmental and aerodynamic requirements, drive the overall design. In this paper, we will discuss the existing technologies used in anti-collision lights and the advantages and challenges associated with an LED solution. Particular attention will be given to the optical, thermal, electrical and aerodynamic aspects associated with an LED approach. A specific case study will be presented along with some of the challenges that have arisen during the design process. These challenges include the addition of an integrated covert anti-collision lighting.

  19. Application of high-brightness LEDs in aircraft position lights

    Science.gov (United States)

    Machi, Nicolo; Mangum, Scott; Singer, Jeffrey M.

    2004-10-01

    Solid state lighting devices have made their way into a number of niche markets and continue to make inroads into other markets as their price / performance ratios improve. One of these markets is aviation lighting. Although this paper will focus on the use of LEDs for aircraft position lights, much of the discussion is applicable to other installations on the interior and exterior of the aircraft. The color, light distribution and intensity levels for a position light are all closely regulated through Code of Federal Regulation (CFR; formerly Federal Aviation Regulation (FAR)) documents. These lighting requirements, along with harsh thermal and environmental requirements, drive the design. In this paper, we will look at these requirements and discuss what is required in order to use LEDs for this type of application. We will explore the optical, thermal and electrical issues associated with the use of LEDs for position lights and examine the specific case study of the Astreon forward position lights. Finally, we will discuss some of the challenges that we see with solid state lighting in current and future aircraft applications.

  20. ORAL TRADITION AND HISTORICAL RECONSTRUCTION IN IGBO ...

    African Journals Online (AJOL)

    FBL

    control, which exists in all societies that make for near accurate preservation of traditions ... historical sources from written sources and from material objects. ..... traditions were detached very early from the rural to the urban areas, where urban.