Judul: Peningkatan mutu membran komposit nanopori selulosa asetat-polistirena menggunakan natrium lauril sulfat sebagai porogen
Abstrak: Penelitian ini difokuskan pada modifikasi membran selulosa asetat dengan polistirena dan natrium laud suifat sebagai porogen. Penelitian ini diawali dengan pembuatan membran dari selulosa asetat (CA), polistirena (PS), dan natrium lauril sdfat (SLS) dengan enam ragam komposisi CA:PS:SLS, yaitu 9:1:0,9:1:1,9:1:2, 9: 1 :3, 9: 1:4, dan 9:1:5. Kemudian nilai fluks air setiap membran ditentukan pada tiga tekanan berbeda. Larutan Cr 1000 ppm dilewatkan terhadap membran lallt nilai indeks rejeksi membran dapat ditentukan. Selanjutnya membran dianalisis dengan scanning electron microscpe (SEM).
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Judul: Pencirian membran selulosa asetat dari kulit nanas dengan penambahan poli (Etilena glikol) sebagai porogen
Abstrak: Membran sebagai salah satu alat dalam teknik pemisahan saat ini terus-menerus dikembangkan. Kendala yang terjadi adalah masih tingginya harga bahan baku pembuat membran. Oleh sebab itu, perlu dicari bahan baku lain yang lebih murah seperti kulit nanas untuk pembuatan membran. Pembuatan membran selulosa asetat (CA) dari kulit nanas dengan penambahan poli(etilena glikol) (PEG) sebagai porogen dilakukan dalam penelitian ini. Selulosa bakteri (BC) dari kulit nanas yang dibentuk oleh Acetobacter xylinum dimerserisasi dalam NaOH 1%(b/v). Bubuk BC kering diasetilasi dengan anhidrida asam asetat (selulosa:anhidrida 1:5) selama 2 jam. Membran CA berporogen dibuat dengan cara melarutkan serbuk CA 14%(b/v) dan PEG 10%(b/v) ke dalam diklorometana. Membran dibentuk dengan cara mencetak campuran polimer CA dan PEG dalam pelarut diklorometana menjadi film tipis. Membran CA berporogen dicirikan menggunakan seperangkat alat saring cross-flow. Alat saring cross-flow digunakan untuk pengukuran fluks air dan penyaringan bovine serum albumin (BSA). Penelitian ini menghasilkan membran CA berporogen dengan fluks air yang optimal pada tekanan 0.3470 bar dan nilai rerata fluks sebesar 1680.65 L/m2.jam. Membran CA berporogen memiliki nilai fluks BSA sebesar 1631.44 L/m2.jam dan rerata rejeksi sebesar 3.70%. Oleh karena itu, membran ini memiliki fungsi mikrofiltrasi.
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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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