Judul: Karakteristik biofilm dari bahan dasar polivinil alkohol (PVOH) dan kitosan
Abstrak: Plastik sintesis dikenal sebagai bahan yang tidak ramah lingkungan karena bakteri tidak dapat menguraikannya sehingga akan menjadi masalah lingkungan. Seiring dengan meningkatnya kesadaran untuk pelestarian lingkungan, saat ini telah dikembangkan biofilm, artinya plastik ini dapat diuraikan kembali oleh mikroorganisme secara alami menjadi senyawa yang ramah lingkungan. Pengembangan kitosan sebagai campuran bahan kemasan plastik diharapkan dapat mengurangi ketergantugan manusia terhadap plastik sintesis sebagai bahan pengemas.
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Judul: Pencirian Film Bioplastik dari Tepung Tapioka Terplastisasi Gliserol dengan Penambahan Kitosan
Abstrak: Non-biodegradable synthetic plastic is widely used as packaging. However, the plastic waste can pollute the environment so that bioplastics are developed, which are easily degraded. In this research, packaging films have been made from glycerol and tapioca starch blends with composition ratio of 8:2 and 7:3 as well as various concentrations of chitosan 1, 2, and 3%. The plastics produced were analyzed for the mechanical properties by using tensile strength test, density, functional groups based on Fourier transform infrared spectrophotometer, surface morfology with scanning electron microscope, and thermal properties from differential scanning calorimeter. Addition of plasticizer was found to lower the density. Plastic with 8:2 ratio and addition of 2% chitosan yielded tensile strength 304 MPa and elongation 37%. Functional groups analysis showed that the film was a result of physical mixing. The plastic’s surface was quite homogenous and the melting point was increased with addition of chitosan. Addition of chitosan could increase the mechanical properties and was expected to be easily degradated in the environment.
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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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