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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

SOCIO-ECONOMIC STUDY OF COMMUNITY FORESTS IN MID HILLS REGION OF NEPAL

K.C., Birendra 01 January 2012 (has links)
This research looks at some issues confronting community forestry in Nepal. Analytic Hierarchy Process (AHP) was used to analyze the issues confronting community forestry in mid hills region of Nepal. Results indicate that experts as well as local community users think positive aspects of community forestry to be more important than its negative aspects. In addition, through the comparison of three forest types, Alnus nepalensis found to be the most important forest type for conservation and Schima-Castanopsis to be the most important forest type for local benefits. Similarly, results also indicate that increase in carbon prices lengthen an optimal rotation age. Also, Land Expectation Value (LEV) increases substantially with the increase in carbon prices.
2

Extraction of New Vegetable Tanning Agent from Coriaria nepalensis Bark and Its Application in Tanning

Guo, Linxin, Qiang, Taotao, Ma, Yangmin, Wang, Xuechuan 26 June 2019 (has links)
Content: Traditional chromium tanning agents cannot conform to the requirement of sustainable and cleaner development under current leather producing. Compared with chromium tanning agents, vegetable tanning agents have been widely used in tanning process by the virtue of its non-toxicity, low pollution, biodegradability and regenerability. In this study, a novel vegetable tanning agent was extracted from the Coriaria nepalensis bark (CNB) by alkali solution. In order to optimize extraction conditions, the response surface Box-Behnken design was used in this experiment. The key factors including alkali concentration, extraction time, extraction temperature, liquid to solid ratio and extraction times. The experimental results showed that under the conditions of 0.22% sodium hydroxide concentration, 63 min extraction time, 83℃ extraction temperature and 24 liquid to solid ratio, the yield of tannins in CNB is 15%, tannins in extractives up to 50%. Afterwards, the composition and molecular mass were evaluated, we discovered that the extractives belong to hydrolyzable tannins and its molecular mass ranged from 599 to 1457 Da. Furthermore, the extractives were used in sheep garment tanning process. The results showed that the shrinking temperature of tanned leather can reach to 75 ℃. Applying the extractives to the retanning process, the shrinking temperature of retanned leather can reach to 130 ℃. Surprisingly, the color of tanned or retanned leather coincide with the requirement of light leather. Take-Away: 1 New vegetable tanning agent from Coriaria nepalensis bark. 2 The vegetable tanning agent belongs to hydrolyzable tannins and its molecular mass ranged from 599 to 1457 Da. 3 The shrinking temperature of tanned leather and retanned leather can reach to 75 ℃ and 130 ℃ respectively.

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