Judul: Rekayasa Proses Pembuatan Pewarna Bubuk Alami dari Biji Pinang (Areca catechu L.) dan Aplikasinya untuk Industri
Abstrak: Natural dyes have become alternative of non toxic, environtmentally friendly colorants, usually agro-renewable source and exhibit better biodegradability. Instant natural dyes, e.g. powder extracts, are still limited. Areca catechu L. is one of dye plant that has been traditionally used on batik and craft dyeing. The phenolic substances, as coloring matter, from areca seeds are varying in degree of maturation. For these reasons, design process of natural dye powder production from areca seeds by spray drying and its application in textile dyeing and transparent soap coloring was studied. The objective of this study was to determine the effect of maturation degree of areca seeds (unripe, ripe) and binder treatment (without a binder, arabic gum 2% w/v) to the characteristics of areca seeds powder extracts, and determine the effect of areca seeds dye powder and fixative agents (without a fixative agent, alum, calcium oxide and ferrosulfate) to the colour of two types of fabric (cotton, silk) and the color changes to washing and sun drying. The objective of study about application of areca seeds powder extracts in transparent soap was to determine the effect of areca seeds extracted powders and the type of vegetable oil to the characteristics of transparent soap. Areca seeds powder extracts being used in this study were areca seed powder extracts without a binder and areca seed extracted powder with a binder (arabic gum 2% w/w). Two types of vegetable oil for making transparent soap were used in this study namely coconut oil and mixed of coconut oil and palm oil (15:5 w/w). As a control, there were transparent soaps made without addition of areca seeds powders. The results of this study exhibited unripe areca seeds produced powder extracts with higher in yield, moisture content and total phenolic content but had no significant effect on pH and lower in bulk density and solubility than ripe areca seeds. Arabic gum treatment produced powder extracts with higher in yield, and solubility, but had no significant effect on moisture content and lower in bulk density, pH and total phenolic content than the treatment without binder. The areca seeds powder extracts had the yield ranges between 5,59-13,90%, moisture content ranges between 5,19% - 7,41%, bulk density ranges between 0,3720 – 0,5586 g/ml, solubility (on water) ranges between 94,10% – 99,25%, pH ranges between 4,98 – 5,31, total phenolic content ranges between 30,50 – 67,07% and oHue ranges between 39,67 – 62,06 (red and yellow red). FTIR spectrum showed presence of functional group of OH, CH, CO and aromatic structure in areca seeds dye powder. The areca seed powder extracts exhibited cytotoxic activity against brine shrimp larvae with LC50 values ranging from 279,53-1093,25 ppm. The fixative agents had significant effects on colour of cotton and silk fabric. Alum caused the depth of fabric colour as same as or lower than colored fabric without a fixative agent (color ranges in red and yellow red). The highest viii depth of fabric colour is given by ferrosulfate was followed by calcium oxide. Calcium oxide give the little color changes on both cotton and silk fabric in washing
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Judul: Ethnobotanical Study of Natural Food and Clothing Dyes in Belitung Regency
Abstrak: Perkembangan zaman serta kemajuan teknologi membuat pengetahuan akan pewarna alami pangan maupun sandang semakin berkurang dan banyak yang beralih menggunakan pewarna sintetis. Penelitian ini bertujuan untuk mengidentifikasi karakteristik responden, pemanfaatan dan status tumbuhan pewarna alami pangan maupun sandang. Metode penelitian ini menggunakan teknik snowball sampling dan purposive sampling. Hasil penelitian menunjukan bahwa responden pewarna alami pangan maupun sandang didominasi oleh perempuan dengan usia produktif. Tingkat pendidikan mayoritas lulusan SMA/SMK dan sumber pengetahuan diperoleh di tempat kerja dan secara otodidak. Terdapat 15 spesies pewarna alami pangan dan 19 spesies pewarna alami sandang yang dimanfaatkan serta sebagian besar diperoleh dengan cara membeli. Bagian dan warna yang dihasilkan pada pangan dan sandang didominasi bagian daun dan warna kuning. Tumbuhan pewarna yang termasuk langka teridentifikasi 12 spesies, yaitu 2 spesies Appendix II CITES, 6 spesies Least Concern IUCN, 1 spesies Near Threatened IUCN, dan 3 spesies Data Deficient IUCN, The development of the times and technological advances have made knowledge of natural food and clothing dyes decrease and many have switched to using synthetic dyes. This research aims to identify the characteristics of respondents, utilization and status of natural coloring plants for food and clothing. This research method uses snowball sampling and purposive sampling techniques. The results showed that respondents of natural food and clothing dyes were dominated by women of productive age. The education level of the majority of SMA/SMK graduates and the source of knowledge obtained at work and self-taught. There are 15 species of food natural dyes and 19 species of clothing natural dyes that are utilized and most of them are obtained by purchasing. The parts and colors produced in food and clothing are dominated by the leaves and yellow color. There are 12 rare coloring plants identified, namely 2 CITES Appendix II species, 6 IUCN Least Concern species, 1 IUCN Near Threatened species, and 3 IUCN Data Deficient species.
Keyword: Batik, ecoprint, natural dyes, plants

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik