Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Stockwald, K. Kaestle, H. Weiss, H. |
| Copyright Year | 2008 |
| Description | Author affiliation: OSRAM GmbH, Munich (Stockwald, K.; Kaestle, H.; Weiss, H.) |
| Abstract | Modern metal halide high intensity discharge (HID) lamps today represent the class of light sources providing white light with the highest conversion efficiency (36-40%) at a very good colour quality (CRI = 80-95) for general lighting applications. Recent progress on producing ceramic arc tubes with very small tolerances in geometric shape allow to utilize lamp vessels as acoustic resonators. Investigations on the specific acoustic lamp spectra have revealed that the use of arc tubes with enhanced aspect ratio provide a sufficient selectivity of the acoustic modes useful for arc stabilization. However, high aspect ratio arc tube metal halide lamps show the drawback of colour separation by elemental segregation effects especially in vertical burning orientation. We have investigated new schemes of acoustic excitation by applying tuning procedures on the electrical operation power spectrum for lamp operation . By this, a long term stabilized arc straightening and plasma mixing effects can be achieved simultaneously which are counteracting to elemental segregation in any burning orientation. Excitation of a set of well defined acoustic resonances in the lamp plasma leads to stable multi-cell convection structures in the arc, which showed to be beneficial for high aspect ratio HID ceramic lamps in terms of arc stability, thermal loss and luminous efficacy. With the use of metal halide plasma gas compositions based on Na and the rare earth Ce very high electrical-to-visible efficiency of up to 50% can be achieved also for low wattage metal halide systems at 90-120 W. Lamps with warm-white colour (CCT =3000-3500K) show luminous efficacy levels up to 150 $lmW^{-1}$ at a good general colour rendering index (CRI) in the range of 80-85. In combination with adequate electronic control gears based on a lean and low loss circuit topology combined with intelligent programming, new energy-saving HID systems for general lighting applications with high sustainability potential are feasible. |
| Starting Page | 1 |
| Ending Page | 1 |
| File Size | 32625 |
| Page Count | 1 |
| File Format | |
| ISBN | 9781424419296 |
| ISSN | 07309244 |
| DOI | 10.1109/PLASMA.2008.4591142 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2008-06-15 |
| Publisher Place | Germany |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | High intensity discharge lamps Acoustics Metals Plasmas Light sources Color Electron tubes |
| Content Type | Text |
| Resource Type | Article |
| Subject | Atomic and Molecular Physics, and Optics Condensed Matter Physics Electrical and Electronic Engineering |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|