Judul: Hidrogel Poli(Asam akrilat-ko-Akrilamida)-Kitosan Hasil Iradiasi Gamma sebagai Penjerap Ion Cu(II).
Abstrak: Kitosan merupakan senyawa turunan kitin yang dapat dimodifikasi menjadi hidrogel. Hidrogel ini dapat digunakan sebagai adsorben untuk menjerap ion Cu(II). Hidrogel poli(asam akrilat-ko-akrilamida)-kitosan dapat disintesis dari asam akrilat, akrilamida, dan kitosan menggunakan teknik iradiasi gamma. Dosis yang digunakan dalam iradiasi ini sebesar 10 kGy. Komposisi kitosan yang digunakan dalam hidrogel ini sebesar 0.25 g, 0.5 g, 1.0 g, dan 1.5 g. Hidrogel terbaik yang digunakan dalam menjerap ion Cu(II) adalah hidrogel dengan komposisi kitosan terbanyak, yaitu 1.5 g. Nilai equilibrium degree of swelling (EDS) yang diperoleh sebesar 11.33 g/g dan fraksi gel mencapai 93.18%. Nilai kapasitas adsorpsi yang diperoleh dari kitosan beads dan hidrogel relatif sama, hanya berbeda pada waktu kontaknya. Adsorpsi isotermal yang terjadi pada kedua adsorben mengikuti model isotermal Freundlich.
Keyword: adsorpsi, EDS, fraksi gel, hidrogel, kitosan

Judul: Hidrogel Berbahan Dasar Asam Akrilat dan Karagenan sebagai Penjerap Ion Cu(II).
Abstrak: Hidrogel adalah polimer hidrofilik berbentuk jaringan berikatan silang, berkemampuan swelling dalam air, serta memiliki daya difusi air yang tinggi. Karagenan dapat digunakan sebagai bahan baku dalam pembuatan hidrogel. Tujuan penelitian ini adalah melakukan karakterisasi material dan uji kinerja hidrogel poli(asam akrilat)-ko-iota karagenan dengan teknik irradiasi gamma, dan menguji kapasitas adsorpsi hidrogel terhadap ion Cu(II). Karakterisasi material hidrogel dengan scanning electron microscope (SEM), dan fourier-transform infrared spectroscopy (FTIR). Uji kinerja hidrogel dilakukan dengan equilibrium degree of swelling (EDS), fraksi gel, uji adsorpsi terhadap ion Cu(II) dan isoterm adsorpsi. Nilai fraksi gel, EDS, dan kapasitas adsorpsi terbesar yaitu berturut-turut 96.12%, 694.54 g/g, dan 541.77 mg/g pada sampel 2 g iota karagenan. Pencirian hidrogel menggunakan FTIR menunjukkan serapan gugus –OH, -OSO3-, dan –CO pada bilangan gelombang 3570.24 cm-1, 1226.73 cm-1, dan 1666.50 cm-1. Adsorpsi isoterm menunjukkan hidrogel poli(asam akrilat)-ko-iota karagenan belum mengikuti tipe model isoterm Freundlich dan Langmuir.
Keyword: hidrogel, iota karagenan, isoterm adsorpsi

Judul: Biology and ecology of the buffalo fly, haematobia exigua de meijere (diptera:muscidae)
Abstrak: The life history of the buffalo fly was observed at room temperature of 27°-29.5°C and at a relative humidity of 48-68 percent. The eggs hatched after 17-22 hours, with an average of 18 hours. First instar larvae measured 1.25 + 0.16 mm long and 0.27 + 0.037 mm wide. reach the second larval stage. It took 6-12 hours to the second instar larvae measured 2.676 +0.187 mm long and 0.353 +0.028 mm wide. The second instar took about 12-24 hours to reach the third larval stage. The third instar measured 6.833 + 0.189 mm long and 0.919 + 0.051 mm wide. It took about 2-3 days for the third instar to become pupae. Duration of the pupal stage was about 5-7 days before the adults emerged. Under laboratory condition, the buffalo fly completed its life cycle in 9.5 to 10.5 days, whereas under field condition it took 9-14 days with an average of 10.5 days. The growth ratio which was based on the measurements of the cephalo-pharyngeal skeleton of each instar was 1.797. The preoviposition period was 8-12 days and mating usually occurred on the 6th or 7th day. The longevity of the male was 29 days, whereas it was 32 days in the female. The range of egg production under laboratory condition was between 20-139 per female fly. The belly and hind legs of the carabao were the most preferred habitat either during cloudy and cool dry or shiny and warm day. When the weather was clear and the carabao was in the shade, the flies tended to be more distributed particularly on the shoulder, dewlap, back and horns. The carabaos had relatively fewer Musca sp. and Stomoxys calcitrans than cattle; never the less carabaos had a higher infestation of buffalo fly than cattle. Oviposition occured either during the day or night but the buffalo flies were more active during the night than in the day time. The effect of various lengths of exposure time of manure in relation to the oviposition was profound. observed, the maximum number of the buffalo flies was occurred when the dung was exposed for 30 minutes. With increasing time of exposure the number and variety of insects also increase. It was evident that Sepsidae and psychodidae were the most dominant insects emerging from the dung. The number of buffalo flies also increased with increasing
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