Judul: Penggunaan Kitosan dan Lilin Lebah sebagai Bahan Pelapis untuk Meningkatkan Masa Simpan dan Mempertahankan Kualitas Buah Pepaya
Abstrak: Papaya is a climacteric fruit with increased respiration rate during ripening process. Respiration rate papaya can be inhibited by providing a coating on the surface of the fruit. Coating materials that can be used include chitosan and beeswax. The purpose of this research is to study the effect of chitosan and beeswax coating on the shelf life and quality of Callina papaya fruit during storage. Experiment was carried from November 2014 until March 2015 at the Experimental Field of PKHT, Tajur and Postharvest Laboratory, Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University. The experimental design used was completely randomized design with 3 treatments and 3 replications, there are chitosan 0.75%, beeswax 6%, and the control (without coating). Data were analyzed by F test and treatments that affect were analyzed by Duncan Multiple Range Test (DMRT). Parameters measured were shelf life, the index of fruit skin color scale, respiration rate, weight loss, skin firmness, pulp firmness, total soluble solids, total titratable acids, and the content of vitamin C. Results of the experiments showed that chitosan and beeswax treatments can extend the shelf life of papaya Callina 4–5 days compared to control because it inhibits respiration rate papaya during storage. The use of chitosan and beeswax can maintain the physical and chemical quality of papaya fruit Callina.
Keyword: Callina, chemical quality, physical quality, postharvest ripening, respiration rate

Judul: Pengaruh Pelapisan Kitosan terhadap Daya Simpan dan Kualitas Buah Pepaya (Carica papaya L.).
Abstrak: Pepaya merupakan buah klimakterik dengan daya simpan yang rendah. Pemberian pelapis pada buah pepaya Callina dapat memperpanjang daya simpan dengan tetap mempertahankan kualitas buah. Tujuan penelitian ini adalah untuk menguji pengaruh penggunaan kitosan sebagai bahan pelapis alami terhadap daya simpan dan kualitas buah pepaya. Penelitian dilaksanakan bulan Desember 2016 sampai Juni 2017. Percobaan dilaksanakan di kebun Mekarsari, Kecamatan Rancabungur, Kabupaten Bogor. Pengujian pascapanen di Laboratorium Pascapanen, Departemen AGH IPB. Rancangan percobaan yang digunakan adalah Rancangan Kelompok Lengkap Teracak (RKLT) satu faktor yaitu konsentrasi kitosan dengan tiga ulangan. Parameter yang diukur adalah umur simpan, laju respirasi, susut bobot, kekerasan kulit dan daging buah, padatan terlarut total, asam tertitrasi total, dan kandungan vitamin C. Pelapisan kitosan dapat memperpanjang umur simpan pepaya Callina dengan menekan laju respirasi. Pelapisan kitosan 0,25%, 0,5%, 0,75%, dan 1% menghasilkan umur simpan hampir sama dengan umur simpan rata-rata 11 Hari Setelah Perlakuan (HSP) dan dapat memperpanjang daya simpan buah selama 3 HSP dibandingkan dengan kontrol. Pelapis kitosan dengan taraf konsentrasi yang berbeda tidak mempengaruhi mutu fisik dan kimia buah.
Keyword: kitosan, kualitas fisik, kualitas kimia, laju respirasi

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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