Judul: Distribusi Ikan pada Dua Musim di Perairan Pulau Gebe, Halmahera Tengah dengan Metode Akustik.
Abstrak: Hydroacoustic technology was applied to detect fish distribution in Gebe Island, Central Halmahera thus providing the information about the optimal time of fishing. This study aimed to measure Sv value in detecting the location fish and to measure environmental factors related to Sv distribution in Gebe Island, Central Halmahera. Split Beam Hydroacoustic method was applied in this study using Biosonic DTX 1000 equipment. Acoustic data processing was run in Echoview 4.8, Ms-Excel 2007, ODV (Ocean Data View) 4.1, and 10.0 Surfer. The use of software also helps to interpret results that were conducted in two seasons. Data interpretation showed vertical and horizontal Sv distribution and temperature distribution in Gebe Island, Central Halmahera. This research revealed that large quantities of fish were found at 25-50 meters depth in February, while in October the most quantity of fish is found at 5-25 meters.
Keyword: two seasons, ., depth, distribution, acoustic, fish

Judul: Fenomena Pendugaan Densitas Ikan di Pinggiran Paparan  Selat Makassar Dengan Metode Akustik Bim Ganda.
Abstrak: Survei hidro akustik, saat ini merupakan metode tercanggih untuk eksplorasi sumber daya hayati laut dibanding metode Iainnya. Saal ini ketelitian pengukuran dengan alat akustik semakin baik dengan adanya prosesing data birn ganda (dual beam processing) yang dikombinasikan dengan echo integration. Echo integration memperoleh densitas relatif dari seluruh lintasan kolom air yang dideteksi. In situ target tren,:th di proses oleh birn ganda untuk memperoleh ukuran ikan yang Iebih akurat. Sehingga dengan kombinasi ini sebaran densitas dalam bentuk populasi dengan satuan ekorlm3 dan biomassa dengan satuan kglm3 yang tersebar dalam kolom air dapat dideteksi. Penelitian ini dilakukan pada tanggal 8 s/d 11 Pebruari 199S. Data dari echo integrator yang berasal dari peralatan akustik birn ganda dikumpulkan secara kontinu, selama siang dan malam hari dengan kapal Bawa! Putih I. Data target strength diperoleh menurut periode waktu tertentu yang dianggap mewakili, sedangkan data basil tangkapan dan salinitas serta suhu diperoleh dari beberapa stasion peng;unatan. Penelitian ini melintasi slope paparan Selat Makassar, dan berbentuk diagonal yang tidak beraturan yang berjumlah 8 ( delapan) lintasan ( diagonal). Strata kolom perairan dibagi per IO meter, dimulai pada kedalaman 2 meter sesuai letak transducer. dst ...
Keyword: Dual beam processing

Judul: Prenilasi Senyawa β-Diketon sebagai Prekursor 3-Prenilflavon
Abstrak: One group of flavonoids that has not been commonly synthesized is 3- prenylflavone. The main objective of this experiment was to synthesize precursor of 3-prenylflavone. Firstly, β-diketone was synthesized via 4 steps from phenol as starting compound with total yield of 24%. Prenylation of β-diketone with prenyl bromide and K2CO3 base produced 4 fractions which were separated by using preparative thin layer chromatography (PTLC) with n-hexane:EtOAc (8:2) as the eluent. Fraction with Rf = 0.80 was further separated by using preparative PTLC with n-hexane:EtOAc (99:1) as the eluent. Two fractions were obtained with Rf = 0.38 and 0.42. The first fraction has been characterized as diprenylated β-diketone with 49% yield. Application of protecting group on the phenolic OH group in β- diketone are needed to obtain monoprenylated β-diketone which can be further cyclized into 3-prenylflavone
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