Judul: Keragaman Kadar Lignin pada Kayu Reaksi Apiapi dan Kelarutannya dalam Delignifikasi Alkali.
Abstrak: Reaction wood is a wood xylem formed as a respons of tree to external forces. Reaction wood has different chemical characteristics compared with normal wood. This research aimed to examine the variation of lignin contents at different positions in the reaction wood of Api-api (Avicennia sp.), and lignin solubility in alkali cooking. Klason lignin and acid-soluble lignin contents were determined using Klason method and UV-spectrophometry. Cooking experiment was carried out in 20% alkali solution at 150 C for 45 min. Klason lignin content varied between samples position was 15.03-20.8%, and acid-soluble lignin content was 3.06-4.29%. Wood samples derived from severest reaction wood part tend to have lowest Klason lignin content and highest acid-soluble lignin content. The lignin solubility of Api-api wood in the alkaline cooking at 150 C for 45 min was 46.13-54.47%. Although the statistical test was not significant, however, the lignin Avicennia sp. wood was relatively easy to be delignified in alkali cooking.
Keyword: Avicennia sp., reaction wood, klason lignin, acid-soluble lignin

Judul: Kadar Lignin dan Delignifikasi Empat Jenis Kayu Eukaliptus.
Abstrak: Lignin content and its reactivity are known as an important characteristics of wood in relation to the pulping process, because it will affect the process easiness and pulp quality. The aim of the research was to measure lignin content and delignification of four Eucalyptus woods, which is widely used as raw material in pulp industry. Lignin content was determined as Klason lignin, acid soluble lignin, and total lignin, whereas delignification was expressed as solubility lignin in alkaline cooking. The result show that Klason lignin of four Eucalyptus woods were 25.14-36.65% and acid soluble lignin were 2.07-2.44%. Alkaline cooking at 150 °C for 90 min obtained solubility of lignin 18.54-31.60%. The variety of acid soluble lignin of four Eucalyptus woods was not big different, therefore delignification was influenced by Klason lignin.
Keyword: acid soluble lignin, delignification, Eucalyptus, lignin solubility, Klason lignin

Judul: Proyeksi Penduduk Indonesia Menggunakan Model Deterministik dan Model Stokastik Kelahiran dan Kematian
Abstrak: Proyeksi penduduk adalah perhitungan jumlah orang yang diharapkan untuk hidup di masa mendatang dengan melihat jumlah penduduk saat ini. Proyeksi penduduk dibuat sebagai dasar untuk mengantisipasi hal-hal yang dapat mengubah proses dan kecenderungan penduduk saat ini. Di samping itu, proyeksi penduduk juga dapat digunakan untuk mengantisipasi kemungkinan perubahan tren yang diakibatkan oleh perubahan secara tiba-tiba dari faktor-faktor yang berkaitan erat dengan variasi demografi. Karya ilmiah ini menyajikan proyeksi penduduk Indonesia melalui dua pendekatan. Pendekatan pertama adalah dengan model deterministik, yaitu model pertumbuhan linear, geometrik, eksponensial, hiperbolik, dan logistik. Pendekatan kedua adalah dengan model stokastik kelahiran dan kematian, yaitu model kelahiran murni, model kelahiran dan kematian, tanpa dan dengan migrasi. Berdasarkan data sensus penduduk Indonesia tahun 2010 dibuat proyeksi penduduk Indonesia tahun 2015-2035. Dibandingkan dengan data proyeksi yang dilakukan oleh Badan Pusat Statistik, proyeksi dengan model stokastik kelahiran dan kematian dengan migrasi mampu memberikan hasil yang lebih baik daripada model yang lain.
Keyword: deterministic models, population projection, stochastic models of birth and death