Judul: Karakterisasi Sistem Multifase yang Terdiri atas Minyak Sawit Merah dan Air dengan dengan Partikel Nano Seng Oksida sebagai Penstabil
Abstrak: This study investigated the stability and rheological properties of multiphase systems comprising red palm oil and water, with zinc oxide nanoparticles (ZnO NPs) as stabilizers. Multiphase systems with 60% and 70% oil contents exhibited excellent physical stability. To achieve a stable multiphase system, a 60% v/v oil content required 1.50% w/t ZnO NPs. However, when the oil content was increased to 70% v/v, only 0.75% w/t ZnO NPs were required. Increasing ZnO NPs concentration enhanced system stability, as demonstrated by minimal changes in the total carotenoid content and reduced lipid oxidative product formation. Based on rheological characterization, these multiphase systems exhibited shear-thinning flow behavior and viscoelastic properties. The multiphase system consisting of 70% v/v RPO stabilized by 1.50% w/t ZnO NPs was identified as the best multiphase formulation. Conclusively, the findings in this study are valuable insights for formulating stable multiphase systems, composed of red palm oil and water.
Keyword: multiphase system, red palm oil, ZnO nanoparticles, physicochemical stability

Judul: Pengaruh Jenis dan Konsentrasi Emulsifier terhadap Kestabilan dan Sifat Reologi Emulsi Oil in Water Minyak Sawit Merah
Abstrak: Oil in water (o/w) emulsion are a system where an oil is dispersed in an aqueous phase. Preliminary study was fractionation of red palm oil. This process was hold at 60°C for 10 minutes to obtain olein which used as raw material of oil in water emulsion. Futhermore, an optimal oil in water emulsion formulation was selected from the best water and oil ratio that was blended with several concentration of emulsifier. The ratio of water and oil were 6:4, 7:3, 7,5:2,5 and 8:2. This study used Carboxymethylcellulose (CMC), Arabic gum and Tween 80 as emulsifier in various concentrates. The result showed that Carboxymethylcellulose (CMC) at 0,55%, 0,60%, 0,65% and 0,70% (w/v) of concentration combined with 6:4 water and oil ratio was optimal o/w emulsions formulation. The optimal formulation were evaluated for emulsion stability (colour, carotene content and droplet size distribution) and rheology properties. The result of emulsion stability indicated that 0,65% and 0,70% (w/v) of CMC concentrations were stabilized. The rheology properties showed that all of optimal o/w emulsions formulation behaved as pseudoplastic (non-newtonian). This study indicated that viscosity of o/w emulsion was significantly affected by heat. However, the stirring on viscosity of o/w emulsions effect could be ignored. Based on stability and rheology evaluation, 0,65% (w/v) of CMC concentration was the best formulation for oil in water red palm oil emulsion.
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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