Judul: Membran komposit polisulfon tersulfonasi–kitosan untuk aplikasi direct methanol fuel cell
Abstrak: Krisis energi memicu suatu inovasi baru dalam upaya pemenuhan energi. Sel bahan bakar metanol merupakan salah satu energi alternatif yang sedang dikembangkan. Penelitian ini menyintesis dan mencirikan membran komposit polisulfon tersulfonasi-kitosan (spsf-kitosan) serta mempelajari pengaruh penambahan kitosan pada kinerja membran. Polisulfon disintesis dengan oleum sebagai agen sulfonasi pada suhu 40 °c selama 60 menit. Membran komposit dihasilkan dengan menambahkan polisulfon tersulfonasi dan kitosan dengan konsentrasi 4% dan 5%. Keberhasilan proses sulfonasi ditunjukkan oleh nilai derajat sulfonasi, yaitu 45%. Selain itu pada pencirian membran menggunakan spektrofotometer inframerah transformasi fourier terdapat puncak yang tertrisubstitusi 1,2,4- pada 1724 cm-1. Uji sem menunjukkan bahwa terlihat interaksi fisik pada membran komposit. Membran komposit spsf–kitosan 5% memiliki konduktivitas proton dan beda potensial tertinggi sebesar 1.74 х 10-3 s/cm dan 427 mv dengan elektrode logam. Berdasarkan hasil, membran komposit spsf-kitosan dapat diaplikasikan dalam sistem direct methanol fuel cell
Keyword: kitosan, membran komposit, polisulfon tersulfonasi, sel bahan bakar

Judul: Composite of sulfonated polysulfone–titanium dioxide membrane for application on direct methanol fuel cell
Abstrak: Penelitian ini menyintesis dan mencirikan membran polisulfon tersulfonasititanium dioksida (sPSf-TiO2). Sulfonasi dilakukan pada suhu 40 °C selama 60 menit menggunakan oleum sebagai agen sulfonasi dan TiO2 ditambahkan untuk meningkatkan kinerja membran. Derajat sulfonasi sebesar 47.5% dan morfologi membran menunjukkan bahwa tambahan TiO2 membuat membran lebih rapat dibandingkan tanpa tambahan TiO2. Membran yang dicirikan dengan spektrofotometer inframerah transformasi fourier menunjukkan puncak gugus sulfonat tertrisubtitusi 1,2,4- pada 1724 cm-1. Membran komposit diperoleh dengan menambahkan polisulfon tersulfonasi dengan TiO2 dengan ragam konsentrasi 3% dan 5%. Nilai konduktivitas dan beda potensial tertinggi dihasilkan pada membran sPSf-TiO2 5% dengan nilai berturut turut 1.07 × 10-3 S/cm dan 422 mV. Berdasarkan ciri tersebut, membran komposit sPSf-TiO2 dapat diaplikasikan untuk direct methanol fuel cell., This experiment is to synthesize and to characterize sulfonated polysulfonetitanium dioxide composite membranes (sPSf-TiO2). The sulfonation was done in 40 °C for 60 minutes using oleum as the sulfonation agent and TiO2 was added to improve membrane performances. The degree of sulfonation through sulfonation process was 47.5% and the morphology of the membrane showed that the addition of TiO2 made the membrane denser than that without TiO2. The infared spectra showed there was 1,2,4- trisubstituted sulfonate group at 1724 cm-1. The composite membrane was produced by adding sulfonated polysulfone and TiO2 with concentration of 3% and 5%. The composite membrane sPSf-TiO2 5% gave the highest proton conductivity and voltage as of 1.07 × 10-3 S/cm and 422 mV, respectively. Based on the result, the composite membrane sPSf-TiO2 can be applied for direct methanol fuel cell system.
Keyword: membran komposit, polisulfon tersulfonasi, sel bahan bakar, titanium dioksida

Judul: Estimation of Additive and Non-Additive Genetic Variances of Body Weight, Egg Weight and Egg Production for Quails (Coturnix coturnix japonica) with an Animal Model Analysis
Abstrak: This study estimates the additive and non-additive variances for egg production and body weight traits of two lines of quails from a long-term selection with the help of the REML method. For the body weight of 42-day-old females (BW42f) and males (BW42m), a total of 7,934 records for line 1 and 7,214 records for line 2 from 21 generations were used in our analyses. Additionally, 1,717 records of females from line 1 and 1,671 records of females from line 2 contained information on their egg production at an age of 42 to 200 days (EN200), on the average egg weight for the first 11 weeks of their laying season (EW1), on the average egg weight from weeks 12 to 23 (EW2), and on their body weight at an age of 200 days (BW200f). A multivariate additive animal model and one-trait dominance models, which include the inbreeding coefficients as covariates, were fitted to the data. The estimates of the heritability gained from our dominance models were smaller than those from the additive model. For line 1, the heritability values decreased for EN200 from 0.35 to 0.32, for EW1 from 0.66 to 0.56, for BW200f from 0.42 to 0.38, and for BW200m from 0.51 to 0.49, respectively. For the first line, the respective ratio (d2) of the dominance variance to the phenotypic variance for EN200, EW1, BW200f and BW200m was 0.08, 0.22, 0.09 and 0.21, and the values for the second line were 0.12, 0.06, 0.001 and 0.23.
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