Judul: Sifat Fisis Mekanis Papan Pelupuh Orientasi Dari Bambu Ater (Gigantochloa atter Kurz.) Dengan Perlakuan Alkali
Abstrak: Papan pelupuh merupakan papan komposit yang tersusun dari lembaran berstruktur dengan memipihkan bambu. Tujuan dari penelitian ini adalah menganalisis sifat fisis dan mekanis papan orientasi pelupuh dari bambu ater (Gigantochloa atter Kurz.) dengan perlakuan alkali. Bambu ini relatif memiliki diameter kecil dan dinding yang tipis, umum digunakan sebagai bahan baku alat musik dan alat rumah tangga. Perendaman alkali dilakukan dengan tiga variasi konsentrasi yaitu 0% (kontrol), 2%, dan 5%. Papan pelupuh dibuat 3 lapis dengan kerapatan target 0,6 g/cm3 menggunakan perekat isosianat. Pengujian sifat fisis mengacu pada standar JIS A 5908:2003, sedangkan sifat mekanis mengacu pada standar ASTM D 5456-99, ASTM D 1037-99, dan EN 300:1997 yang kemudian hasilnya dibandingkan dengan standar CSA 0437.0 (Grade O-1) dan JIS A 5908. Hasil pengujian menunjukkan sifat fisis dan mekanis papan orientasi pelupuh bambu menurun dengan meningkatnya konsentrasi alkali. Secara keseluruhan, papan kontrol masih memenuhi kualitas kelas satu dari standar CSA 0437.0 – 2011 mengenai OSB dan Waferboard yang memenuhi standar., Laminated bamboo is a composite board that is arranged by oriented structure sheets composed of flattening bamboo. This study aimed to determine the physical and mechanical properties of oriented laminated board from Gigantochloa atter Kurz bamboo, which is known as ater bamboo. This bamboo has a relatively small diameter and thin walls mainly used for musical instruments and household appliances. The alkali treatments were carried out into the strip-strand raw material in the 0% (control), 2%, and 5% concentration. A three-layer flattened board with a density target of 0,6 g/cm3 with the isocyanate resin was applied in this study. Mechanical properties using the modified ASTM D 5456-99, ASTM D 1037-99, and EN 300:1997, and the result were compared to CSA 0437.0 (Grade O-1) and JIS A 5908 standard. The result showed that physical and mechanical properties of oriented flattened bamboo board decsreasing with increasing alkaline concentration. Based on research, only control boards that passed the quality of first grade of the Canadian Standard for OSB and waferboard.
Keyword: alkaline treatment, ater bamboo, isocyanate, strand, zephyr board

Judul: Physical, Mechanical, and Surface Quality of Oriented Flattened Bamboo Boards made from  Betung Bamboo (Dendrocalamus asper) with Alkali Treatment
Abstrak: Salah satu produk komposit dari bambu adalah papan pelupuh. Tujuan dari penelitian ini adalah untuk menganalisis pengaruh perlakuan alkali (NaOH konsentrasi 2% dan 5%) terhadap sifat fisis, mekanis, dan kualitas permukaan papan pelupuh orientasi dari bambu betung. Tujuan perlakuan alkali adalah untuk mengatasi komponen kimia minor yang ada pada permukaan bambu. Evaluasi karakteristik fisis dilakukan untuk kerapatan, kadar air, pengembangan tebal, daya serap air dan uji siklik. Modulus of Elasticity (MOE), Modulus of Rupture (MOR), keteguhan tekan, dan keteguhan rekat internal (IB) dievaluasi untuk sifat mekanis. Selain itu dilakukan juga pengujian kekasaran permukaan. Hasil penelitian menunjukkan bahwa nilai rata-rata kerapatan, kadar air, pengembangan tebal, dan daya serap air masing-masing berkisar 0,62 – 0,64 g cm-3; 8,94 – 13,53%; 12,21 – 17,94%; dan 71,32 – 83,04%. Nilai MOE, MOR, keteguhan tekan dan IB masing – masing papan pelupuh berkisar antara 1187,03 – 3267,70 MPa; 8,75 – 21,53 MPa; 7,11 – 15,10 MPa; dan 0,06 – 0,28 MPa. Papan dengan perlakuan NaOH memiliki karakteristik sifat fisis mekanis yang lebih rendah dibandingkan dengan papan tanpa perlakuan NaOH (kontrol). Semakin tinggi konsentrasi perlakuan NaOH, semakin rendah sifat fisis dan mekanisnya. Kualitas produk yang kurang baik diduga karena masih adanya kulit bambu pada bahan baku bambu., One of the composite products made from bamboo is the flanttened board. The objective of this research was to analyze the effect of alkali treatment (NaOH concentration 2% and 5%) on the physical, mechanical, and surface quality of the orientated flattened board of betung bamboo. The purpose of alkali treatment is to overcome the minor chemical components present on the bamboo surface. The evaluation of physical characteristics was carried out for density, moisture content, thickness swelling, water absorption and cyclic test. Modulus of Elasticity (MOE), Modulus of Rupture (MOR), compressive strength, and internal bond strength (IB) were evaluated for mechanical properties. In addition, the surface roughness test was carried out. The results showed that the average values of density, moisture content, thickness swelling, and water absorption were in the range of 0,62 – 0,64 g cm-3; 8,94 – 13,53%; 12,21 – 17,94%; 71,32 – 83,04%. Meanwhile, the MOE, MOR, compressive strength and IB ranged from 1187,03 – 3267,70 MPa; 8,75 – 21,53 MPa; 7,11 – 15,10 MPa; dan 0,06 – 0,28 MPa, respectively. The boards with NaOH treatment had lower physical and mechanical characteristics compared to the board without NaOH treatment (control). The higher the concentration of NaOH treatment, the lower the physical and mechanical properties. The poor quality product was presumably the presence of bamboo skinned in the material’s bamboo.
Keyword: alkali treatments, betung bamboo, flanttened board, isocyanate, NaOH

Judul: Pengaruh vaksinasi terhadap dinamika populasi pada model SIR (Susceptible-Infected-Recovered)
Abstrak: SIR model can be used to model the spread of diseases in a closed population based on certain assumptions. In this research, the SIR model is formulated by including the factor of vaccination. As the result, the model has been shown to have two equilibrium points, i.e. disease free and endemic equilibrium. A simulation study is carried out to illustrate the model. The results show that some equilibrium points are asymptotically stable. Moreover, a minimum level of vaccination has been defined. For the vaccination level less than the minimum level, increase in the vaccination level results in decrease of the proportion of infected individuals in the corresponding equilibrium point. On the other hand, for the vaccination level greater than the minimum level, increase in the vaccination level results in decrease the proportion of susceptible individuals in the corresponding equilibrium point. Furthermore, when vaccination level is greater than the minimum level, it is found that the time needed for the disease to extinct is shorter.
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