Please wait, while we are loading the content...
| Content Provider | IEEE Xplore Digital Library |
|---|---|
| Author | Sun Liang Hou Hong Dong Liying Wan Fangrong |
| Copyright Year | 2009 |
| Abstract | A new approach is proposed for measuring the sound absorption coefficient of material at normal incidence, that bases on the echo-pulse method in a circular tube. Two types of acoustical material and structure were employed: foam and pipe exit. Two different waveforms called the Butterworth and the damped sine pulse are successfully generated and used as incident pulses in the experiment of sound absorption measurement in a circular pipe. The absorption coefficient of the acoustical material measured by the echo-pulse method is consistent with that of B&K 4206 impedance tube measurement. Discrepancy between them is totally less than 10% in broadband frequency range from 200 Hz to 5k Hz, mainly due to the different internal tube diameters of these two tubes and the fitting of the sample, i.e. the difference between the sample diameter and the internal tube diameter. Since the incident sound pulses are all with the features of regular waveform, short duration and broadband frequency spectrum, sound absorption measurement results conducted by the echo-pulse method are more reliable than that of B&K 4206 impedance tube method especially in low-frequency range. Further validation of this new method is also given through the absorption coefficient measurement of pipe exit. The echo-pulse method is relatively simple as only single microphone is used for measurements. It is believing that this method could also be used for in-situ measurement of sound absorption coefficient in outer space. |
| Starting Page | 281 |
| Ending Page | 285 |
| File Size | 297492 |
| Page Count | 5 |
| File Format | |
| ISBN | 9781424433346 |
| DOI | 10.1109/ICCET.2009.104 |
| Language | English |
| Publisher | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Publisher Date | 2009-01-22 |
| Publisher Place | Singapore |
| Access Restriction | Subscribed |
| Rights Holder | Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
| Subject Keyword | absorption coefficient pipe exit Pulse measurements Extraterrestrial measurements Frequency measurement Microphones Pulse generation Impedance measurement acoustic material Absorption Acoustic materials echo-pulse Acoustic measurements Acoustic pulses |
| Content Type | Text |
| Resource Type | Article |
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...
|