Judul: Kebiasaan Makan Ikan Tuna (Thunnus sp.) Terkait dengan Proses Penangkapan pada Rawai Tuna di Samudera Hindia
Abstrak: Information about fish behavior can be used to improve the effectiveness and efficiency of tuna fishing. One of fish behaviors that can be learned is feeding habits. The objective of this study is to examine feeding time and organism that commonly eaten by tuna in the Indian Ocean at position between 120 - 140 S and 1150 - 1200 E. The analysis was performed by observing stomach content of tuna. There were 19 bigeye tuna (Thunnus obesus), 6 yellowfin tuna (Thunnus albacares), and 6 southern bluefin tuna (Thunnus maccoyii) samples to be analyzed. The calculation of stomach fullness index and index of preponderance showed that the optimum feeding time of three tuna species range from 01.00 pm to 08.00 pm of local time. The prey of tuna was snake mackerel (Gempylus serpens), squid (Loligo sp.) and pomfret (Taractichtys sp). Snake mackerel, pomfret and squid have a bright color therefore it might be tuna use the sense of sight to find their food.
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Judul: Kedalaman Lapisan Renang Tuna (Thunnus sp.) yang Tertangkap oleh Rawai Tuna di Samudera Hindia
Abstrak: The research about swimming layer of tuna conducted in February until April on Indian Ocean. The objective of research was to obtain information about processed of tuna longline operation, analyzed the composition of catches, determined the swimming layer of tuna in Indian Ocean. This research was a case study of the activities of catching tuna on KM. Bina Sejati and KM. Bintang Utara. The total catches were 998 fish from 52 setting during experiment. The member of catches consisted of target catcth were 83 (8,23%), 161 (16,13%) bycatches, and 754 (75,55%) discarded catch. The target catches consisted of bigeyes (Thunnus obesus) which was 44 (53,01%), albacores (Thunnus alalunga) 21 (25,30%), yellowfins (Thunnus albacores) 11 (13,25%), and southern bluefins (Thunnus maccoyii) 7 (8,43%). The majority of bycathes were bullet pomfret which was (Taractichthys sp.) 19,25%, black pomfret (Taractes rubescens) 17,39%, and oil fish (Lepidocybium sp.) 17,39%. The swimming layers of tuna were : albacore (Thunnus alalunga) which was at 64-232 m, bigeye (Thunnus obesus) at 64-250 m, yellowfin (Thunnus albacares) at 64-205 m, and southern bluefin (Thunnus maccoyii) at 110-205 m
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Judul: Katalis Eterifikasi Gliserol Berbasis Poli–(asam stirena sulfonat) dari Limbah Styrofoam.
Abstrak: Styrofoam waste can be converted to poly–(sulfonate styrene acid) (PSSA) that can be used as catalyst. The objective of this research is to get PSSA that can catalyze the etherification of glycerol and benzyl alcohol. The styrofoam waste was converted to PSSA by reacting with H2SO4 98% (as sulfonation agent) and P2O5 (as sulfonation catalyst) at 40 °C for 6 hours. Characterizations of PSSA included functional groups, sulfonation levels, water swelling, and thermal stability. The yield of PSSA was 40-55%. The success of sulfonated polystyrene was shown by –SO3H group absorption at 1157.29 cm-1. Etherification of glycerol and benzyl alcohol using PSSA catalyst was conducted at 110 °C for 12 hours. The conversion in producing mono–benzyl ether glycerol was 8.10%, 1,3–dibenzyletherglycerol 2.60%, and dibenzyl ether 9.80%. Therefore, the PSSA can be used as etherification catalyst.
Keyword: benzyl alcohol, etherification, glycerol, polystyrene, PSSA