Solar kiln drying of tropical hardwoods using a system with a slagbed acting as roughened absorber and heating storage medium

2012 ◽  
pp. 1779-1783 ◽  
Author(s):  
R. Clarke ◽  
R. Saunders
Author(s):  
Khamtan PHONETIP ◽  
Latsamy BOUPHA ◽  
Bounyu PHANOUVONG ◽  
Oudone SICHALUENE ◽  
Khanxay KHAMMANIVONG ◽  
...  

Understanding the rate of drying of standing trees dried by using a solar kiln drying method could help in predicting the change of moisture content in the tree over a period of drying time. The purpose of this study was to observe the change of moisture content profile in a standing tree during drying. A standing Tectona grandis tree was selected for the experiment with a diameter at breast height of 29 cm in a mixed-species plantation. The tree was girdled with 20 cm width at 20cm above ground. For the experiment, the tree was wrapped in a transparent plastic sheet and a black plastic sheet was installed at the bottom with an angle of 39 °C facing Southwest to maximize solar radiation, with the method being modified from the solar kiln method, which is known as a greenhouse type, with 2 layers of plastic cover. The black and white sheets were placed on the inner side for insulation and for collecting heat from the sun’s radiation, while the outer layer was transparent, which allowed radiation to propagate unhindered in the black sheet. In this study, a sensor for temperature and relative humidity (DHT22) was attached inside the wrapped plastic and the data recorded every 6 min. The results showed that drying a standing teak tree from an initial average moisture content of 105 % to a constant point of 60 % took 80 days under the maximum of the collected temperature of 46 °C inside the wrapped plastic; this finding confirmed that the predicted model of recharge and discharge curve was likely accurate.


2018 ◽  
Vol 49 (6) ◽  
pp. 509-528 ◽  
Author(s):  
Orawan Aumporn ◽  
Belkacem Zeghmati ◽  
Xavier Chesneau ◽  
Serm Janjai

2010 ◽  
Vol 33 (10) ◽  
pp. 1873-1880 ◽  
Author(s):  
Chun-Cong XU ◽  
Xiao-Meng HUANG ◽  
Nuo WU ◽  
Ning-Wei SUN ◽  
Guang-Wen YANG

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098533
Author(s):  
Jing-Yuan Peng ◽  
Michael George Botelho ◽  
Jukka Pekka Matinlinna ◽  
Hao-Bo Pan ◽  
Edwin Kukk ◽  
...  

Objective The effects of saliva on demineralized dentin and silver diamine fluoride (SDF) were investigated in vitro. Methods Dentin samples stored in deionized water (DIW), buffer solution (BS), basal medium mucin (BMM), and unstimulated whole saliva (UWS) were demineralized for 3 days and immersed in the same storage media. SDF as a 38 mass% solution was applied to the dentin samples for 3 minutes after they had been replaced in their respective medium. Surfaces were analyzed by scanning electron microscopy, energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Results Scanning electron microscopy showed various surface deposits and coatings, including occlusion of dentinal tubules. DIW resulted in the thinnest coating, whereas BMM resulted in the thickest. EDX and XPS showed the formation of metallic silver and silver compounds in all four media, with the greatest formation in BS. XRD indicated that the main product was silver chloride except in DIW. Sulphur was found in BMM and UWS. EDX and XPS detected fluoride and XRD detected calcium fluoride and fluorohydroxyapatite in BS, BMM, and UWS. Conclusion The interaction between SDF and demineralized dentin was dependent upon the storage medium. BMM provided an outcome most similar to human saliva.


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