Judul: Binderless particleboard made from andong bamboo and sengon wood using oxidation treatment
Abstrak: Nowadays, particleboard is manufactured using formaldehyde based adhesive as a binder. Formaldehyde emission from particleboard is a main concern in contrast to binderless particleboard (BP) which doesn’t cause such problem. The objective of this research was to find out BP production method using oxidation pretreatment. Materials used in this study were andong bamboo (Gigantochloa pseudoarundinaceae), and sengon wood (Paraserianthes falcataria) particles. The target density of BP was 0.75 g cm-3. There are five stages that have been conducted to achieve the research objective namely; determining the best pretreatment of particle, determining of optimum particle size, analyzes of oxidation time and BP characteristics correlation, determining of optimum oxidator level, and comparing BP characteristics with conventional particleboard that produced using urea formaldehyde, melamine formaldehyde, phenol formaldehyde, and isocyanate adhesives. The results indicated that BP made from particle with oxidation pretreatment performed superior characteristics compared to those of BP made from particle only with water boiling pretreatment. Oxidation pretreatment has successfully activated the chemical component of particles that indicated by changes of FTIR spectrum in wave number of 1050 cm-1 for bamboo, 1250 cm-1 and 1740 cm-1 in sengon wood, and decreasing of cellulose cristallinity in activated particles. Particle size which suitable as raw material for the manufacture of BP was particle size passes 10 mesh. Bamboo BP more sensitive on presence of fine particle compared to that of sengon BP. Oxidation pretreatment for 15 minutes was sufficient to produce BP with good physical and mechanical properties. The characteristics of the BP were similar to that of BP made of particles with a longer oxidation time in range of 15-90 minutes. Produced BP using 15%/7.5% (hydrogen peroxide/ferrous sulphate) for bamboo and 5%/5% (hydrogen peroxide/ferrous sulphate) for sengon were optimal oxidator level to produce BP and it’s have superior characteristics in term of dimensional stability and modulus of elasticity compared to those of conventional particleboard. Sengon wood more suitable as raw material for BP production compared to that of andong bamboo.
Keyword: Gigantochloa pseudoarundinaceae, Paraserianthes falcataria

Judul: Karakteristik Papan Partikel Tanpa Perekat dari Serat Sabut Kelapa dengan Perlakuan Oksidasi, Penambahan Parafin dan Waktu Kempa
Abstrak: Manufacture of binderless particleboard from coconut fiber research was done as an effort to use alternatives raw materials in timber industry which has become limited and to reduce adhesives synthetic that has pollute the environment such as urea formaldehyde (UF). Paraffin was expected to make the physical properties of particleboard better. The purpose of this research was to know the characteristics of binderless particleboard from coconut fiber based on particleboard standard JIS A 5908:2003 and determine the influence of oxidation treatment, additional paraffin and time of pressing on the characteristics of particleboard. Oxidation method was done by spraying hydrogen peroxide (15%) and ferrosulfate (7.5%), 10 minutes of pressing and 20 minutes at temperature 180 ºC with a pressure of 25 kgf/cm2. The results: density (0.44-0.56 g/cm3), moisture content (5.94-10.08%), all treatment met the standards. The results of strong hold spanner (19-80 kgf): only combination of oxidation treatment that met the standards. The result of thickness swelling: only combination of oxidation treatment, paraffin 0.5% and without paraffin with 20 minutes of pressing (8% and 12%) met the standards. In conclusion for all the treatment, the one that didn’t meet JIS standard: Internal Bond (IB), Modulus of Elasticity (MOE) and Modulus of Rupture (MOR).
Keyword: pressing time, particleboard, paraffin, oxidation, JIS A5908:2003, coconut fiber

Judul: Mathematical Analysis of a Cholera Spread Infection Model  Using Vaccination
Abstrak: Kolera merupakan penyakit diare yang disebabkan infeksi pada usus oleh bakteri Vibrio cholerae. Bakteri tersebut masuk ke dalam tubuh seseorang melalui makanan dan minuman yang telah terkontaminasi yang akan mengeluarkan enterotoksin di dalam tubuh seseorang pada bagian saluran usus, sehingga menimbulkan diare disertai muntah yang akut dan sangat hebat, dan berakibat seseorang dalam waktu hanya beberapa hari akan kehilangan banyak cairan dalam tubuhnya sehingga mengalami dehidrasi. Penelitian ini bertujuan untuk menganalisis model untuk penyebaran infeksi kolera menggunakan vaksinasi. Terdapat dua titik tetap, yaitu titik tetap bebas penyakit dan titik tetap endemik. Pada simulasi numerik jika nilai reproduksi dasar yakni ℛ0 < 1 maka jumlah individu yang terinfeksi akan berkurang sehingga penyakit hilang. dst.., Cholera is a diarrheal disease caused by infection of the intestine by the bacterium Vibrio cholerae. These bacteria enter a person's body through contaminated food and drink, which will release enterotoxins in a person's body in the intestinal tract, causing diarrhea accompanied by acute and very severe vomiting, and resulting in a person just in a few days of losing a lot of fluids in the body so it becomes dehydrated. This study aims to analyze a model for the spread of cholera infection using vaccination. dst ..
Keyword: fungsi Lyapunov, infeksi kolera, vaksinasi