Judul: Destruksi Hasil Samping Penambangan Timah Belitung Menggunakan Microwave untuk Ekstraksi Unsur Tanah Jarang
Abstrak: Rare earth elements (REE) in pure state are widely used for high-tech electronic equipment. Rare earth elements are contained in by-product of tin mining process. This study attempted to use microwave to destruct sample from by-product of tin mining in Belitung as an effort to obtain pure REE. Parameter of destruction is the ratio sample with NaOH, time, and energy. Preliminary test using X-ray fluorescence shows that the sample contains 377 ppm of lantanum (La) and 125 ppm of yttrium (Y). The best destruction condition occured in ratio sample:NaOH, 35:65 with percentage of destruction 19.96% and 4.48% for La and Y; the best destruction time is 30 minutes by the acquirement of 27.95% La and 4.61% Y; best energy at 450 watt by the acquirement of 38.52% La and 13.86% Y. To get La, destruction uses microwave better than oven, but contrary with Y.
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Judul: Pengayaan Unsur Tanah Jarang Secara Destruksi dan Pengendapan dari Pasir Monasit Bangka
Abstrak: Rare earth elements (REEs) are lanthanide elements widely used in high-tech electronic equipment. In this study, REEs from earth minerals were enriched through several stages, namely destruction, extraction by microwave oven, and precipitation. The dry and wet destruction phases by using NaOH produced a total of 25.56% and 44.30% REEs, respectively. At the extraction by microwaves stage with HCl 37% as solvent, REEs were successfully dissolved in 30 minutes at high energy. Total amount of REEs which contained in the liquid phase from wet and dry destruction were 35.72% and 29.97%, respectively. Precipitation of REEs started when the pH value was higher than 7, reached by using NH4OH 2 N. Total precipitated REEs in wet and dry feed destruction at pH 10 was 2.76% and 1.18%, respectively. Precipitation at pH 10 gave the highest total REEs. Dry feed destruction produced precipitate that effectively enrich REEs by decreasing impurity elements, such as Si and P, and there was no Th element found. It is also contained low U element which was only 12 ppm. This is consistent with the value of percent recovery and the non-radioactive REEs which was smaller than the wet feed destruction, but contains elements of U in the amount of not less than 0.00006 g and without Th element.
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Judul: Ekspresi Gen Imun dan Titer Antibodi Ikan Koi (Cyprinus carpio) Pascavaksinasi dengan Vaksin DNA Anti-KHV yang Berbeda.
Abstrak: Koi herpes virus (KHV) merupakan kelompok virus DNA utas ganda dari family Herpesviridae yang menginfeksi ikan mas dan koi dan menyebabkan penyakit koi herpes virus disease (KHVD). Vaksinasi merupakan langkah efisien dalam pencegahan penyakit KHV dan penelitian ini dilakukan untuk mengevaluasi kinerja vaksin DNA anti-KHV pada ikan koi. Ikan uji yang digunakan adalah ikan koi dengan bobot rata-rata 28,55 ± 0,98 g yang diperoleh dari Balai Besar Perikanan Budidaya Air Tawar Sukabumi, Jawa Barat. Perlakuan pemberian vaksin DNA serta dosis yang digunakan adalah vaksin GP-11 7,5 μg/100 gr ikan (A), GP-11 12,5 μg/100 gr ikan (B), GP-25 12,5 μg/100 gr ikan (C). Perlakuan kontrol yang digunakan adalah injeksi PBS 0,1 mL. Parameter uji meliputi jumlah sel darah putih, ekspresi gen, serta titer antibodi. Jumlah sel darah putih pada perlakuan vaksinasi memiliki jumlah yang lebih tinggi bila dibandingkan dengan kontrol. Ekspresi gen IFNγ, TNFα, dan IgM mengalami fluktuasi selama pemeliharaan pascavaksinasi. Titik puncak dari tiap gen berbeda-beda dipengaruhi oleh jenis vaksin, dosis, dan fungsi dari protein tersebut. Titer antibodi pascavaksinasi mengalami kenaikan hingga akhir pemeliharaan. Titer antibodi ketiga perlakuan terus meningkat hingga mencapai titik puncak pada hari ke-28 pascavaksinasi. Ketiga perlakuan yang terdiri dari dua jenis vaksin dengan dosis yang berbeda mampu meningkatkan sistem imun spesifik ikan koi.
Keyword: Ekspresi gen, ikan koi, koi herpes virus, titer antibodi, vaksin DNA