Judul: Sifat Fisis Kayu Maesopsis eminii Engl. Termodifikasi Asam Borat, Minyak Nabati, dan Pemanasan
Abstrak: Kayu manii (Maesopsis eminii Engl.) merupakan jenis cepat tumbuh dengan kelas awet rendah (IV) sehingga memerlukan pengawetan. Pengawet asam borat bersifat ramah lingkungan namun mudah mengalami ketercucian. Penambahan minyak nabati dan pemanasan diharapkan dapat memperbaiki sifat ketercucian pada asam borat. Penelitian ini bertujuan untuk mengevaluasi pengaruh perlakuan impregnasi asam borat, minyak nabati (mimba, nyamplung, kemiri), dan pemanasan terhadap sifat fisis kayu manii. Kayu manii diimpregnasi bertingkat dengan asam borat dan minyak nabati pada tekanan 7 kg cm-2 selama 4 jam, dilanjutkan dengan pemanasan suhu 70 ℃ dan 140 ℃ selama 4 jam. Pengujian mencakup kerapatan, berat jenis, ketercucian, daya serap air, stabilitas dimensi, dan perubahan warna. Hasil penelitian menunjukan perlakuan asam borat dan minyak nabati mempengaruhi nilai kerapatan, berat jenis, ketercucian, daya serap air, stabilitas dimensi, dan perubahan warna. Pemanasan suhu 140 ℃ menghasilkan peningkatan sifat fisis kayu lebih baik dari suhu 70 ℃. Penambahan minyak kemiri setelah perlakuan asam borat dengan suhu 140 ℃ menghasilkan peningkatan sifat fisis kayu manii yang paling baik seperti menaikan nilai kerapatan dan berat jenis, meningkatkan stabilitas dimensi, menahan ketercucian asam borat dengan perubahan warna kayu yang lebih merata dan menarik., Manii wood is a fast growing wood with a low durability class (IV) so it requires preservation. Boric acid preservative is environmentally friendly but easily being leached. The addition of vegetable oil and heat treatment were expected to restrain the leaching of boric acid. This study aimed to evaluate the effect of impregnation treatment of boric acid, vegetable oils (neem, tamanu, hazelnut), and heat treatment on the physical properties of manii wood. Manii woods were double impregnated with boric acid and vegetable oils at a pressure of 7 kg cm-2 for 4 hours and heat treated at 70 ℃ and 140 ℃ for 4 hours. The physical properties tests of wood samples included density, specific gravity, leaching, water absorption, dimensional stability, and color changes. The results showed that the treatment of boric acid and vegetable oils affected the density, specific gravity, leaching, water absorption, dimensional stability, and color changes of manii wood. Heat treatment at 140 ℃ resulted in better physical properties of manii wood than 70 ℃ heating. The hazelnut oil treatment after boric acid preservation resulted in the best physical properties improvement of manii wood, such as increasing the density and specific gravity, improving dimensional stability, reducing preservative leaching and changing the color to be more even and attractive.
Keyword: boric acid, heat treatment, impregnation, physical properties, vegetable oil

Judul: The Physical and Mechanical Properties of Modified Manii Wood (Maesopsis eminii Engl.) with Boric Acid, Sodium Silicate and Heat Treatment
Abstrak: Kayu manii (Maesopsis eminii Engl.) merupakan kayu cepat tumbuh, tetapi keawetannya rendah (III – IV), maka diperlukan pengawetan. Pengawet asam borat bersifat insektisida maupun fungisida, namun mudah tercuci air. Natrium silikat dan pemanasan diharapkan dapat mengurangi ketercucian. Penelitian ini bertujuan untuk mengevaluasi sifat fisis dan mekanis kayu manii termodifikasi asam borat, natrium silikat dan pemanasan. Kayu manii diimpregnasi dengan asam borat dan natrium silikat dengan tekanan 7 kgf cm-2 selama 4 jam dan pemanasan dengan suhu 70 °C, 140 °C selama 4 jam serta steam 120 °C selama 1,5 jam. Pengujian mencakup kerapatan, berat jenis, daya serap air, ketercucian, anti-swelling efficiency, penyusutan, MOE, MOR dan kekerasan. Perlakuan pasca pengawetan asam borat dengan natrium silikat dan pemanasan 140 °C tidak dapat memperbaiki ketercucian, daya serap air, stabilitas dimensi, MOE dan MOR kayu manii, namun meningkatkan kerapatan, berat jenis dan kekerasannya., Manii wood (Maesopsis eminii Engl.) is fast growing species, but has low durability (III – IV) and requires preservation. Boric acid has insecticidal and fungicidal properties, but is easily washed off by water. Sodium silicate and heating are expected to reduce leaching. This study aims to evaluate the physical and mechanical properties of manii wood modified boric acid, sodium silicate and heating. Manii wood was impregnated with boric acid and sodium silicate at a pressure of 7 kgf cm-2 for 4 hours and heating process with a temperature of 70 °C, 140 °C for 4 hours and steam 120 °C for 1,5 hours. The tests included density, specific gravity, water absorption, leaching, anti-swelling efficiency, shrinkage, MOE, MOR and hardness. Post-treatment following boric acid preservation with sodium silicate and heating at 140 °C did not improve the leaching, water absorption, dimensional stability, MOE and MOR of manii wood, but increased its density, specific gravity and hardness.
Keyword: boric acid, heating, physical-mechanical properties, sodium silicate

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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