Judul: The design process of cellulose acetate ultrafiltration membrane production by phase inversion method of cellulose pulp from wood of sengon (Paraserianthes falcataria.)
Abstrak: Cellulose acetate ultrafiltration membrane has been utilized in a variety of separation and purification processes, including in agro-industry sector. In general, cellulose acetate is obtained from acetylation of cotton cellulose and wood pulp (abaca, straw, sawdust). In this study, cellulose from wood pulp of Sengon (Paraserianthes falcataria) was used. This plant is fast growing species and has potential as a raw material from its high cellulose content. The purpose of this study was to find a cellulose acetate manufacturing process conditions, to characterize cellulose diacetate and its performance on ultrafiltration process. There are three steps of cellulose diacetate manufacturing process. They are: (1) activation of cellulose using acetic acid, (2) acetylation, cellulose in acetic acid solvent is reacted with acetic anhydride reactant using sulfuric acid as catalyst, (3) hydrolysis to obtain cellulose diacetate. At each operating processes acetyl content was observed at temperature 50oC. In addition, effect of variation of anhydride acetate reactant and cellulose ratio, namely (3.35:1), (4:1) (5:1), and (6:1) were also investigated. Asymmetric cellulose diacetate membrane preparation by phase inversion method was carried out by the addition of cellulose diacetate (SDA) as a polymer, N, N-Dimethil formaida (DMF) as solvent, water as a non-solvent, and polyethylene glycol (PEG) as additive. At this stage, effect of PEG / SDA ratio (10%, 20%, 30%), PEG molecular weight variation (1450, 4000, and 6000 Da), and coagulation temperature (15oC, room temperature, and 50oC) were also investigated. Membrane pore size was determined by by measuring Molecular Weight Cut Off ( MWCO) using a standard solution of dextran (12 kDa) and Bovin Serum Albumin (67 kDa). Membrane morphology was observed by Scanning Electron Microscope (SEM). Cellulose acetate of acetyl content of 39.66% and number average molecular weight 130,221 Da was obtained at the activation time 30 minutes; one hour acetylation process for acetic anhydride to cellulose ratio 3.35:1; and 15 hours hydrolysis process. The addition of PEG produced a thicker layer and greater tensile strength membranes and suppress the formation of macrovoid. SEM analysis shows a denser structure of membrane morphology with better regularity of pore shape, so has a better pore density (porosity) distribution of large and visible pores. The addition of PEG with higher molecular weight produces a denser morphological structure with larger pore size, but smaller porosity with large pore distribution. The addition of PEG with the increasing of PEG / SDA ratio resulted in a denser pore structure and greater number of pores with a greater porosity and large pore distribution. Coagulation at higher temperatures produced a thinner layer and low tensile strength membrane. The structure of membrane morphology is more tenuous with a bigger pore size and greater number of pores so large porosity and pore distribution. Flux (water, dextran, and BSA) and rejection (dextran and BSA) are determined by the porosity and pore distribution of the membrane. High flux and rejection generated by large porosity and small pore distribution membrane. Membrane having small porosity and pore distribution produces low flux but high rejection. Conversely, high flux with low rejection obtained from the membrane with greater porosity and pore distribution.
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Judul: Synthesis and Characterization of Cellulose  Acetate Membrane from Cigarette Filters with The Addition of Polyethylene  Glycol (PEG)
Abstrak: Membran adalah lembaran tipis yang selektif dan semipermeabel berbahan organik maupun anorganik yang biasa digunakan dalam proses pemisahan zat. Membran selulosa asetat merupakan membran anorganik yang termasuk ke dalam membran ultrafiltrasi dan biasa digunakan dalam filtrasi air skala besar maupun kecil karena teknologinya yang sederhana. Dalam skala kecil selulosa asetat komersial dapat digantikan dengan filter rokok yang ada di sekitar dan mudah didapatkan. Polietilen glikol diperlukan sebagai zat aditif yang berperan dalam peningkatan kualitas membran. PEG ditambahkan pada larutan membran dengan konsentrasi 10, 20, 30, 40, dan 50%. Membran dikarakterisasi dengan permeabilitas, kekuatan mekanik, porositas, analisis gugus fungsi, dan morfologi permukaan membran. Karakterisasi permeabilitas membran dilakukan dengan pengujian fluks air sistem dead-end. Membran tanpa penambahan PEG mulai mengalami fouling setelah waktu filtrasi mencapai 2 jam. Kekuatan mekaniknya dianalisis dengan elastisitas dimana membran dengan penambahan PEG 40% memiliki modulus Young paling rendah yang berarti elastisitasnya paling tinggi. Kualitas membran paling baik adalah membran dengan ketahanan terhadap bakteri, fluks air tanpa fouling, elastisitas paling tinggi, serta porositas efektif yang besar. Dengan penambahan konsentrasi PEG sebesar 40%, kualitas membran selulosa asetat mampu ditingkatkan sebagai filtrasi air., Membranes are selectively thin, semi-permeable sheets. Neither organic nor inorganic are commonly used in the process of separating substances. Acetate cellulose membrane is an inorganic membrane that is included in ultrafiltration membranes are commonly used in large-scale water filtration. It's small because of its simple technology. In small scale cellulose acetate commercial can be replaced by cigarette filters that are around and easy got it. Polyethylene glycol is needed as an additive that plays a role in improved membrane quality. PEG is added to the membrane solution with concentrations of 10, 20, 30, 40, and 50%. Membranes are characterized by permeability, mechanical strength, porosity, function cluster analysis, and morphology membrane surface. Membrane permeability characterization is done with dead-end system water flow testing. Membrane without adding PEG starts fouling after the filtering time reaches 2 hours. analyzed with elasticity where the membrane with the addition of 40% PEG has the lowest Young’s modulus which means the highest elasticity. The best membrane quality is a membrane with resistance to bacteria, water flow without fouling, highest elasticity, as well as effective porosity With a 40% increase in PEG concentration, the quality of the membrane cellulose acetate can be enhanced as water filtration.
Keyword: cellulose acetate, cigarette filters, filtration, membrane, PEG

Judul: Penyebaran Sarang Komodo di Pulau Longos dan Perilaku Bersarang Komodo di Pulau Rinca, Nusa Tenggara Timur.
Abstrak: Komodo tersebar di dalam kawasan Taman Nasional Komodo (TNK) dan di pulau-pulau kecil di luar TNK. Penelitian ini bertujuan untuk memetakan sebaran sarang komodo di Pulau Longos dan mendeskprisikan perilaku bersarang komodo di Pulau Rinca. Survei menggunakan peta grid 300x300 m dilakukan untuk mencari sarang komodo di Pulau Longos. Pengamatan perilaku bersarang komodo di Pulau Rinca dilakukan terhadap empat individu komodo dengan metode focal animal sampling. Ditemukan 86 sarang yang menyebar secara berkelompok di Pulau Longos. Di sebagian besar dari sarang yang ditemukan terdapat jerat untuk menangkap burung gosong, yang bisa menjadi ancaman bagi populasi komodo. Teridentifikasi lima kategori perilaku bersarang betina komodo di Pulau Rinca, yakni berjalan, pemeliharaan diri, menjaga, menggali, dan kawin. Perilaku pemeliharaan diri merupakan perilaku yang paling sering dilakukan (41,67%) dan perilaku menjaga merupakan satu-satunya perilaku penjagaan anak oleh komodo.
Keyword: komodo, Longos, perilaku, Rinca, sarang