Judul: Effect of Pyrolysis Temperature and Time on the Characteristics of Liquified Betung Bamboo as a Source of Aromatic Compounds
Abstrak: Pemanfaatan seluruh bagian biomassa sebagai bahan baku berbagai produk merupakan upaya meningkatkan efisiensi sumber daya alam. Bambu betung terliquifikasi (bio-oil) hasil pirolisis memiliki kandungan senyawa aromatik, sehingga berpotensi untuk menjadi sumber bahan kimia alami terbarukan. Tujuan penelitian ini adalah untuk menganalisispengaruh suhu dan waktu pirolisis terhadap karakteristik bambu betung terliquifikasi, dan potensi pemanfaatannya sebagai sumber senyawa aromatik. Pirolisis serbuk bambu betung dilakukan pada suhu 400 dan 500 °C selama 30 dan 60 menit pada masing-masing variasi suhu. Karakterisasi bambu betung terliquifikasi meliputi pengujian gugus fungsi, stabilitas termal, komposisi kimia, nilai pH, dan densitas. Hasil penelitian menunjukkan bahwa bio-oil hasil pirolisis dengan suhu 400 °C selama 60 menit menghasilkan kandungan senyawa toluena tertinggi (2,71%). Produk bio-oil ini memiliki sifat asam (pH 2,21) dan densitas tertinggi (1,338 g/mL). Kandungan senyawa aromatik toluena pada bio-oil berpotensi sebagai bahan baku untuk memproduksi pelarut, bahan bakar, dan bahan kimia alami., The utilization of all parts of biomass as raw material for various products is an effort to increase natural resource efficiency. Liquified betung bamboo (biooil) resulting from pyrolysis contains aromatic compounds, so it has the potential to be a source of renewable bio-chemicals. This study aims to analyze the effect of temperature and pyrolysis time on the characteristics of liquefied betung bamboo and its potential use as a source of aromatic compounds. Pyrolysis of betung bamboo powder was conducted at 400 and 500 °C for 30 and 60 minutes at each temperature variation. The characterization of liquefied betung bamboo included functional group, thermal stability, chemical composition, pH value, and density. The results showed that bio-oil from pyrolysis at 400 °C for 60 minutes produced the highest toluene content (2.71%). The bio-oil product was acidic (pH 2.21) with the highest density (1.338 g/mL). The toluene compound in bio-oil has the potential as a raw material for producing solvents, bio-fuels and bio-chemicals.
Keyword: aromatic compound, betung bamboo, bio-oil, pyrolysis, senyawa aromatik, bio-chemical

Judul: Pirolisis limbah kayu dan bambu yang ramah lingkungan untuk menghasilkan asam asetat
Abstrak: The research goal is to produce liquid smoke through pyrolysis process and to get fractions of potential chemical components from woods and bamboo wastes. These raw materials contain adequate hemicellulose, cellulose and lignin. These studies revealed relationship between type of raw materials and compound composition of liquid smoke products. Results of this research are expected to give benefits as follows: (1) Liquid smoke produced from wood and bamboo wastes through pyrolysis process is able to diversify preservative products, aplication of liquid smoke was done at tuna fish and tofu, (2) Model of pyrolysis kinetics was established from Arrhenius and Tsamba equations to observe influence of pyrolisis time and resident time. From calculation of kinetics constant, it can be calculated activation energy (Ea), pre exponential factor (A), half-life time (t½), while, pyrolysis thermodynamics was obtained from entropy, enthalpy and Gibbs free energy changes. From the three liquid smoke produced from pyrolisis of these raw materials, liquid smoke of bamboo gave the highest liquid smoke residue as much as 61.34%, followed by liquid smoke pine tree by 49.60 % and liquid smoke of teak tree produced 43.78%. This indicated that liquid smoke residue produced during pyrolisis process was dependend on the types of raw materials used. Identification of GC-MS of teak, pine and bamboo dust could provide compounds that mostly derived from acid is group of dominant volatile compounds. Identification of compound group of phenol, acid, ester, ketone, alcohol, furan and so on, then followed by separation process to determine acetic acid compound that potential to be used as natural preservative. Its difference is Arrhenius model focused discussion on the impact of temperature to the kinetics constant in form of particle size without heating rate. Tsamba model focused discussion to the impact of pyrolisis temperature to the yield, pre exponential factor and reverse to the heating rate.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf