Judul: Studi Pemanfaatan Tanin dari Gambir (Uncaria gambir Roxb) sebagai Produk Peluruh dan Pencegah Karat pada Logam
Abstrak: Gambier (Uncaria gambier (Hunt.) Roxb) is a genus of flowering plant species in Rubiaceae family. Part of the gambier utilized is the sap which is extracted and then to be dried. Indonesia is the world largest exporter of gambier in the form of raw material. Gambier has major components namely catechin and tannin. Tanin can be used as rust deactivator. High tannin content in gambier may be used as anti-corrosion material thought corrosion is a problem in the industry. The aims of this study were to add value of raw gambier and to obtain the best product formulas that can remove the rust and protect metal from rust (antirust). Preliminary study was conducted by tannin extraction from raw gambier of Lima Puluh Kota regency, measuring the purity level of tannin which was extracted and proxymat analysis of raw gambier and tannin powder. The main study conducted by creating rust remover and anti-rust solution using two-factors completely randomized design consisting of composition factor of tannins and phosphoric acid. Tannin level used in the solution were 2,5%, 3,33% and 4,17%, while level of phosphoric acid were 2,9%, 5,8% and 8,7%. After obtaining the best composition of phosphoric acid and tannin, then the study continued by making ethanol concentration as variable which were 10%, 13% and 16%. Analysis test of solution effectiveness were rust lost of weight analysis and metal appearance analysis, while for anti-corrosion solution, the analysis of metal appearance analysis and Fourier Transform Infrared (FTIR) were done. The tannin level obtained from the material used was 66,76%. Rusty iron soaked with rust converter formula successfully lost its rust content after six hours soaked. From lost weight analysis, it was known that the addition of tannin or phosphoric acid has a significant effect (α = 5 %) to decrease the weight of rust, but the interaction between tannin and phosphoric acid showed no significant results. The best concentration of tannin, phosphoric acid, and ethanol in the formula were 3,33%, 5,8% and 16% respectively. On the test with anti-rust effectiveness yielded that the metal plate was immersed in 3% NaCl for one day, had experienced corrosion while the previous metal plate coated with anti-rust solution had no corrosion on the surface. After one week, the metal plate was given a protective layer had corrosion in certain points, whereas the metal plate that was not given protective layer had corrosion on all over the surface. Results of Fourier Transform Infrared (FTIR) analysis on a rusty metal plate coated with anti-rust solution for one week showed the presence of tannin shown by several functional groups namely OH, CO, C = C aromatic, and C = O and the reaction between tannin and metals at a wavelength of 1625 cm-1. The present of tanin indicated that gambier tannin could react well with metal so it can be used as anti corrosive product
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Judul: Studi pemanfaatan gambir (Uncaria gambir Roxb) dalam proses pewarnaan kain mori
Abstrak: Gambier is an extract of leaves and branches of gambier plant (Uncaria gambier Roxb). Gambier is one of Indonesia export commodities mostly produced in Sumatera island. Indonesia plays role as the world’s largest gambier exporter. In Indonesia, gambier utilized traditionally as leather tanning material, ingredient of traditional medicine, rust omission, etc. Chemical components of gambier mostly utilized are catechin and tannin. Technology of gambier processing that existed in Indonesia is still low in capacity, so the processing of gambier is mostly done traditionally. This kind of processing resulted on low quality and lack of economical value products of gambier. Therefore, development of processing method and wide utilization of Gambier in industry are needed to increase gambier added value. Tannin and catechin on gambier also can be utilized as colouring agent in textile industry to gain reddish brown colour on batik clothes that will be endure on intense sunlight exposure. Textile industries in Indonesia, especially batik industries, are now developing rapidly where the trend of batik clothes on every occasion is becoming common interest. On technological side, in general the batik industrialists have not done any development on their production sytem and method, so they could be more productive and produce uniformity of product quality. Utilization of natural colouring agent is also not becoming a consideration of most batik industrialists in the environmental issue that is now being widely concerned.
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Judul: Karakteristik Anatomi Skelet Kepala Buaya senyulong (Tomistoma schlegelii).
Abstrak: Buaya sepit atau senyulong (Tomistoma schlegelii) merupakan jenis buaya asli Indonesia yang berhabitat di sungai-sungai Sumatera, Kalimantan, dan juga pedalaman Sulawesi. Salah satu ciri khas buaya senyulong adalah bentuk moncong yang runcing dan sempit, namun hingga saat ini informasi mengenai struktur skelet kepala buaya senyulong sangat terbatas. Penelitian ini bertujuan untuk mempelajari karakteristik anatomi skelet kepala buaya senyulong yang dikatikan dengan fungsi dan perilakunya. Penelitian dilakukan secara eksploratif dengan melakukan pengamatan, pencatatan, dan pengambilan gambar dari skelet kepala buaya senyulong. Skelet kepala berukuran panjang 70 cm, lebar 29 cm, dan tingggi 17 cm dengan permukaan kasar pada os nasale, os frontale, os maxilla, os mandibula, os lacrimale, os jugale. Jumlah gigi pada buaya ini sebanyak 78 buah, terdiri dari 4 buah gigi premaxila, 16 buah gigi maxila, dan 19 buah gigi mandibula. Pada regio orbitalis ditemukan dua pasang fenestrae temporales yang berkembang baik. Fenestra supratemporale merupakan lubang oval yang membentang di sepanjang os parietale. Fenestra infratemporale berbentuk segitiga dan dibatasi oleh os squamosum, os postorbitale, os jugulare, dan os quadratum. Os mandibula hewan ini mempunyai symphysis mandibularis yang panjang yaitu garis yang melintang di corpus mandibulae. Secara fungsional ukuran symphysis mandibularis berkaitan dengan adaptasi hewan terhadap diet makan.
Keyword: kepala, moncong, Tomistoma schlegelii