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| Control of Air Exchange and Particle Deposition within the Buddhist Cave Temples at Yungang, China | ||
| 作者 | Christoforou, Christos S. |
|---|---|
| 出版日期 | 1995 |
| 頁次 | 153 |
| 出版者 | California Institute of Technology |
| 出版者網址 | http://www.caltech.edu |
| 出版地 | Pasadena, CA, US [帕薩迪納, 加利福尼亞州, 美國] |
| 資料類型 | 博碩士論文=Thesis and Dissertation |
| 使用語言 | 英文=English |
| 學位類別 | 博士 |
| 校院名稱 | California Institute of Technology |
| 系所名稱 | Mechanical Engineering |
| 指導教授 | Cass, Glen Rowan |
| 畢業年度 | 1995 |
| 關鍵詞 | 石窟=cave; 佛教人物=Buddhist; 緣起=paticca-samuppada=pratitya-samutpada=conditions; 緣起=pratitya-samutpada=conditions=paticca-samuppada; 雕塑=雕刻=Sculpture; 禪定=Concentration=Dhyana |
| 摘要 | The Yungang Grottoes are a collection of man-made Buddhist Cave Temples in China that were carved into the face of a cliff in the 5th century AD. The caves contain more than 50,000 Buddhist sculptures, some of which retain their historical coloring. These sculptures are soiled at a rapid rate by the deposition of airborne particles, generated in part by activities in one of China's largest coal mining regions. During the month of April, 1991, and for a year thereafter, an extensive environmental monitoring experiment was conducted there. The overall purpose of that work was to characterize the exposure of the grottoes to air pollutants in a manner that will establish a basis for the future protection of the grottoes from air pollution damage. Average airborne particle mass deposition rates to horizontal surfaces inside Caves 6 and 9 were measured. These rates are comparable to the rates inferred by examination of historically accumulated deposits within those caves. A theoretical model based on natural convection heat transfer processes at the cave wall surfaces has been developed that predicts the air exchange between outdoors and the interior of the caves. Computer-based models also have been constructed that simulate the particle deposition processes within the caves. Predicted aerosol size distributions and particle deposition fluxes within Caves 6 and 9 at Yungang are compared to experimental observations made during the period April 15-16, 1991. It is found that horizontal surfaces within Caves 6 and 9 at Yungang would become completely covered by a full monolayer of deposited particles in only 0.3-0.5 years under the April 15-16 conditions studied here, and will be soiled even more rapidly under annual average conditions. Finally, alternative approaches to the control of the particle deposition problem within the Yungang Grottoes are examined. Two general approaches are possible: (1) control of particle concentrations in the outdoor air through reduction of particle generation at local sources, and (2) removal of particles from the air entering the caves by filtration or similar technical means. Both mechanical filtration and passive filtration systems are examined. |
| 點閱次數 | 510 |
| 建檔日期 | 2008.04.23 |
| 更新日期 | 2016.03.22 |
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