Judul: Morfologi dan kinerja membran selulosa asetat dengan tambahan cetil trimetil amonium bromida untuk pervaporasi metanol
Abstrak: Pembuatan membran untuk aplikasi pervaporasi telah berhasil dilakukan berdasarkan hasil uji karakterisasi morfologi dan kinerja membran selulosa asetat (CA) dengan porogen cetil trimetil amonium bromida (CTAB) yang dilapisi dengan polivinilpirolidon (PVP). Membran CA dibuat dengan metode pembalikan fase. Pembuatan membran diawali dengan pembuatan larutan campuran polimer CA (17% (b/v)) dan CTAB 0.5% (b/v), 1.0% (b/v), 1.5% (b/v), dan 2.0% (b/v) di dalam aseton. Larutan tersebut kemudian disonikasi selama 10 dan 20 jam. Berdasarkan hasil analisis dengan spektrofotometer inframerah fourier tertransformasi menunjukkan adanya serapan dari gugus-gugus fungsi yang berasal dari CA dan tidak terdapat gugus fungsi yang berasal dari CTAB. Pencirian membran dengan pengukuran laju alir menunjukkan bahwa nilai rerata fluks air membran dengan sonikasi 20 jam (16.2583-167.67 L/m²jam) memiliki nilai fluks yang lebih besar dibandingkan dengan membran yang dibuat dengan sonikasi 10 jam (14.9458-66.3958 L/m².jam). Berdasarkan hasil analisis metanol dengan kromatografi gas, diperoleh konsentrasi metanol sesudah pervaporasi mengalami kenaikan konsentrasi sebesar 24.12%. Hal ini membuktikan bahwa membran CA-CTAB-PVP dapat digunakan untuk aplikasi pervaporasi metanol.
Keyword: Pervaporasi, Fouling, Bogor Agricultural Universit

Judul: Pervaporasi Metanol Menggunakan Membran Selulosa Asetat/Polivinil Pirolidon dan Natrium Dosesil Sulfat
Abstrak: Pervaporation membrane is one of alternative methods to purify methanol. Performance of the pervaporation is affected by its characteristics. Phase inversion technique was used for preparing the membrane. The membrane was prepared by mixing polymeric solution of cellulose acetate (CA) and sodium dodecyl sulfate (SDS) as template in acetone solution. Composition of CA was 17% w/v and composition of SDS were varied 0; 0.5; 1; 1.5; dan 2% w/v. The solution was stirred by ultrasonic for 10 and 20 hours and it was casted on the glass plate surface and then submerged it into water of 60 oC. The membrane was coated by polyvinyl pyrrolidon. The performance of pervaporation was evaluated through permeation flux and separation factor and then was calculated for its pervaporation separation index (PSI) value. In this research, permeation flux and separation factor were contradicted results, but PSI was proportional to the separation factor. High permeation flux and separation factor are desired in the performance of pervaporation. The results showed that methanol concentration from pervaporation product by CA membrane with SDS 2% b/v in 20 hours stirring by ultrasonic was 79% from feed solution of 60%. Therefore, this membrane is applicable for methanol pervaporation, but it still needs some improvements.
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Judul: Distribution and Diversity of Ectoparasite Mites on Geckos in Indonesia
Abstrak: Data on the diversity and dispersal of parasitic mites on house geckos in Indonesia are very scarce. In this work, the distribution and diversity of mites living on three species of house geckos, namely Cosymbotus platyurus, Hemidactylus frenatus, and H. garnotii collected throughout Indonesia, has been elaborated. Geckos and mites were captured and immediately preserved in 70% ethanol. Whole mount of the mites was prepared by clearing in lactophenol followed by mounting on polyvinyl lactophenol solutions. The SEM preparation was conducted to examine the detail morphological characters of the mites. The results showed that among 448 individuals of geckos, 221 geckos were infected by Geckobia mites. Prevalences of C. platyurus, H. frenatus, and H. garnotii infested by mites were 14.8%, 50.69%, and 79.6%, respectively. Three different spesies of Geckobia (G1, G2, and G3) could be differentiated; and based on similarities of their morphological characters to ones described in published literatures, Geckobia G2 is Geckobia glebosum and Geckobia G3 is Geckobia bataviensis while G1 could not be identified to the species level. The highest mean intensity of Geckobia G1 infestation was found on H. garnotii (I=7.0), G. glebosum infestation on H. frenatus (I=3.5), and G. bataviensis infestation on H. garnotii (I=11.8). In general, C. platyurus was infested by the least number of mites. Geckobia G1 were found living on the skin folds on the claws, G. glebosum were found mainly on the body and thigh, and G. bataviensis were found on almost all parts of the host’s body. Geckobia mites are distributed randomly throughout Indonesian Archipelago, following the pattern of distribution of their hosts. So it is concluded that Geckobia G1, G. glebosum, and G. bataviensis are sympatric.
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