Palaquium gutta (Gutta Percha Tree) : 無料・フリー素材/写真
Palaquium gutta (Gutta Percha Tree) / wallygrom
| ライセンス | クリエイティブ・コモンズ 表示-継承 2.1 |
|---|---|
| 説明 | Peradeniya Botanical Gardens near Kandy, Sri Lanka.Palaquium is a genus of about 120 species of trees in the family Sapotaceae. Their range is from India across Southeast Asia, Malesia, Papuasia and Australasia, to the western Pacific Islands.The leaves are typically spirally arranged and often clustered near twig ends. Flowers are mostly bisexual, though some unisexual instances are known. Fruits are one or two-seeded with rare instances of several seeds. Palaquium habitats are coastal, lowland mixed dipterocarp, swamp and montane forests.Some species, for example Palaquium gutta, are well known for producing gutta-percha latex.Chemically, gutta-percha is a polyterpene, a polymer of isoprene, or polyisoprene, specifically (trans-1,4-polyisoprene). The cis structure of polyisoprene is the common latex elastomer. While latex rubbers are amorphous in molecular structure, gutta-percha (the trans structure) crystallizes, leading to a more rigid material.During the second half of the 19th century, gutta-percha was used for many domestic and industrial purposes, and it became a household word. In particular, it was needed as insulation for underwater telegraph cables, which, according to author John Tully, led to unsustainable harvesting and collapse of supply.Gutta-percha remained an industrial staple well into the 20th century, when it was gradually replaced with superior synthetic materials such as Bakelite.The same bioinertness that made it suitable for marine cables also means it does not readily react within the human body. It is used in a variety of surgical devices and during root canal therapy. |
| 撮影日 | 2017-01-15 13:55:20 |
| 撮影者 | wallygrom |
| タグ | |
| 撮影地 | |
| カメラ | Canon PowerShot SX410 IS , Canon |
| 露出 | 0.004 sec (1/250) |
| 開放F値 | f/5.0 |
| 焦点距離 | 21201.64615 dpi |