Judul: Properties of Particle Board from Elephant Dung Modified with Alkaline Treatment
Abstrak: Kerusakan hutan Indonesia yang meningkat berdampak pada penurunan produksi kayu. Biomassa alternatif dari limbah diperlukan berupa kotoran gajah. Kotoran gajah tersedia berlimpah di alam dan kandungan seratnya tinggi. Biomassa ini potensial dijadikan papan partikel, tetapi keawetannya rendah. Oleh karena itu, penelitian ini bertujuan untuk menganalisis pengaruh perlakuan alkali terhadap kualitas papan partikel kotoran gajah. Metode yang digunakan berupa perlakuan lama perendaman alkali pada kotoran gajah dan pembuatan papan partikel berperekat asam sitrat molase. Hasil pengujian menunjukkan kerapatan yang dihasilkan dengan rata-rata sebesar 0,63 g/cm3 dan kadar air rata-rata sebesar 7,49% telah memenuhi JIS A 5908-2003. Nilai daya serap air, pengembangan tebal, keteguhan lentur, keteguhan patah, keteguhan rekat, dan kuat pegang sekrup belum memenuhi JIS A 5908-2003. Analisis FTIR menunjukkan tidak ada ikatan ester antara perekat dan serat kotoran gajah dengan perlakuan alkali, XRD menunjukkan puncak selulosa pada 15,97° dan 35,04°, serta analisis TGA dan DSC dengan suhu kempa optimal pada 200 °C.
Keyword: kotoran gajah

Judul: Karakteristik Papan Partikel Kotoran Gajah Termodifikasi Perlakuan Perendaman Air Panas
Abstrak: Penggunaan bahan baku alternatif berupa limbah ampas dari kotoran gajah memiliki banyak manfaat. Kandungan selulosa yang tinggi membuat kotoran gajah dapat dimanfaatkan sebagai papan partikel. Penelitian ini bertujuan untuk mengetahui pengaruh dari waktu perendaman air panas (0 menit, 30 menit, 60 menit, 90 menit, 120 menit) terhadap papan partikel kotoran gajah. Papan partikel direkatkan menggunakan perekat asam sitrat-molase rasio 50/50 dengan target kerapatan 0,6 g/ cm3 dan ukuran 25 cm x 25 cm x 0,9 cm. Papan partikel menggunakan kempa panas suhu 200oC dalam waktu 10 menit. Standar yang digunakan untuk pengujian fisis dan mekanis yaitu JIS A 5908:2003 tipe 8. Papan partikel kotoran gajah dengan perlakuan perendaman air panas dalam pengujian fisis telah memenuhi standar JIS 5908:2003 kecuali pengembangan tebal. Sedangkan pengujian mekanis telah memenuhi standar JIS 5908:2003 kecuali keteguhan lentur dan keteguhan rekat belum memenuhi standar. Hasil analisis FTIR menunjukkan adanya ikatan ester pada perekat asam sitrat-molase dan papan partikel kotoran gajah., The use of alternative raw materials in the form of waste pulp from elephant dung has many benefits. The high cellulose content makes elephant dung can be utilized as particleboard. This study aims to determine the effect of hot water soaking time (0 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes) on elephant dung particleboard. The particleboard was glued using a 50/50 ratio citric acid-molasses adhesive with a target density of 0.6 g/cm3 and a size of 25 cm x 25 cm x 0.9 cm. The particleboard was hot-felted at 200°C for 10 minutes. The standard used for physical and mechanical testing is JIS A 5908:2003 type 8. Elephant dung particleboard with hot water immersion treatment in physical testing has met the JIS 5908:2003 standard except thickness development. While mechanical testing has met the standards of JIS 5908:2003 except flexural firmness and adhesive firmness have not met the standards. FTIR analysis showed the presence of ester bonds in citric acid-molasses adhesive and elephant dung particleboard.
Keyword: kotoran gajah, sifat fisis, sifat mekanis, physical properties, mechanical properties, perlakuan perendaman air panas, elephant dung, hot water immersion treatment

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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