Judul: Optimization of Kraft Pulping Process of Rice Straw (Oryza sativa) as a Biomaterial for Biomedical Pulp Products
Abstrak: Jerami padi umumnya hanya dimanfaatkan sebagai pakan ternak, dibiarkan membusuk, dan dibakar cenderung memiliki dampak negatif terhadap lingkungan. Pemanfaatan jerami padi dapat menjadi alternatif sebagai bahan baku pulping karena mengandung selulosa cukup tinggi. Penelitian ini mengkaji potensi jerami padi sebagai bahan baku pulp untuk produk pulp biomedis menggunakan proses pulping kraft. Response surface methodology dengan model central composite design digunakan untuk mengoptimalkan kondisi pulping kraft jerami padi dengan kadar alkali aktif, sulfiditas dan waktu pemasakan sebagai variabel bebas. Pembuatan pulp dilakukan pada suhu 170 °C dengan nisbah L/W pemasakan 20:1 dan sampel 500 berat kering oven. Rendemen tersaring dan selektivitas delignifikasi digunakan sebagai parameter respon untuk menentukan kondisi pulping kraft yang optimum. Hasil penelitian menunjukkan bahwa kondisi pulping kraft optimum terdapat pada konsentrasi kadar alkali aktif 17%, sulfiditas 21,15%, dan waktu pemasakan 120 menit. Hal ini dapat ditunjukkan dengan rendemen pulp dan selektivitas delignifikasi yang tinggi. Pada kondisi optimum ini, pulp dapat digunakan sebagai bahan pembuatan pulp biomedis., Rice straw is generally only used as animal feed, left to rot, and burned tends to have a negative impact on the environment. The utilization of rice straw can be an alternative as raw material for pulping because it contains high enough cellulose. This study examined the potential of rice straw as a pulp raw material for biodegradable biomedical pulp products using the kraft pulping process. The response surface methodology with central composite design model was used for optimizing the kraft pulping condition of rice straw with active alkaline content, sulfidity and pulping time as independent variables. The pulping was conducted at a temperature of 170 °C with an L/W ratio of 20:1 and a sample of 500 ovens dry weight. Screen pulp yield and delignification selectivity were used as response parameters to determine the optimum pulping kraft condition. The result shows that the optimum pulping kraft conditions were found at a concentration of active alkaline content of 7%, sulfidity of 21,15%, and pulping time of 120 minutes. It can be indicated by high screen pulp yield and delignification of selectivity. In this condition, the optimum pulp can be used as a material for biomedical pulp.
Keyword: delignification of selectivity, pulp kraft, response surface methodology, screen yield

Judul: Manufacture and Characterization of Nonwood Paper from Dry Sugarcane Leaves and Rice Straw Waste as Paper Bags
Abstrak: Bahan nonkayu menjadi alternatif untuk mengatasi kebergantungan akan kayu dalam industri kertas. Daun kering tebu dan jerami padi merupakan dua contoh limbah pertanian pascapanen yang belum banyak dimanfaatkan. Penelitian ini bertujuan membuat kertas yang dapat digunakan sebagai kantong kertas dengan memanfaatkan limbah daun kering tebu dan jerami padi. Daun kering tebu dan jerami padi dicampurkan dalam tiga perlakuan (%b/b), T1 (50:50), T2 (75:25), dan T3 (25:75). Pulp dibuat secara kimiawi menggunakan NaOH 10% pada suhu ±100 °C selama 120 menit. Pulp lalu dicampurkan dengan perekat PVAc 5% sebelum dicetak menjadi lembaran berukuran A4. Hasil uji ANOVA menunjukkan pengaruh yang nyata (P<0,05) antara perbedaan nisbah bahan baku dengan nilai gramatur, ketahanan tarik, dan ketahanan sobek kertas. Perlakuan T3 menghasilkan kertas terbaik, memenuhi standar mutu kertas, dan dapat digunakan sebagai kantong kertas., Nonwood materials are an alternative to overcome dependence on wood in the paper industry. Dried leaves of sugarcane and rice straw are two examples of postharvest agricultural waste that has not been widely utilized. This research aims to prepare a paper that can be used as paper bags by utilizing dry leaf waste of sugarcane and rice straw. Dried leaves of sugarcane and rice straw were mixed in three treatments (%w/w), T1 (50:50), T2 (75:25), and T3 (25:75). The pulp was chemically prepared using 10% NaOH at ±100°C for 120 min. The pulp was mixed with 5% PVAc adhesive before molding into A4-sized sheets. The ANOVA test results showed a significant effect (P<0.05) between the various ratios of raw materials to grammage, tensile strength, and tear resistance of the paper. T3 treatment produced the best paper, complies with paper quality standards, and can be used as paper bags.
Keyword: agricultural waste, dry sugarcane leaves, paper, paper bags, rice straw

Judul: Distribution and Diversity of Ectoparasite Mites on Geckos in Indonesia
Abstrak: Data on the diversity and dispersal of parasitic mites on house geckos in Indonesia are very scarce. In this work, the distribution and diversity of mites living on three species of house geckos, namely Cosymbotus platyurus, Hemidactylus frenatus, and H. garnotii collected throughout Indonesia, has been elaborated. Geckos and mites were captured and immediately preserved in 70% ethanol. Whole mount of the mites was prepared by clearing in lactophenol followed by mounting on polyvinyl lactophenol solutions. The SEM preparation was conducted to examine the detail morphological characters of the mites. The results showed that among 448 individuals of geckos, 221 geckos were infected by Geckobia mites. Prevalences of C. platyurus, H. frenatus, and H. garnotii infested by mites were 14.8%, 50.69%, and 79.6%, respectively. Three different spesies of Geckobia (G1, G2, and G3) could be differentiated; and based on similarities of their morphological characters to ones described in published literatures, Geckobia G2 is Geckobia glebosum and Geckobia G3 is Geckobia bataviensis while G1 could not be identified to the species level. The highest mean intensity of Geckobia G1 infestation was found on H. garnotii (I=7.0), G. glebosum infestation on H. frenatus (I=3.5), and G. bataviensis infestation on H. garnotii (I=11.8). In general, C. platyurus was infested by the least number of mites. Geckobia G1 were found living on the skin folds on the claws, G. glebosum were found mainly on the body and thigh, and G. bataviensis were found on almost all parts of the host’s body. Geckobia mites are distributed randomly throughout Indonesian Archipelago, following the pattern of distribution of their hosts. So it is concluded that Geckobia G1, G. glebosum, and G. bataviensis are sympatric.
Keyword: