Judul: Sifat Korosif Surfaktan MES (Metil Ester Sulfonat) terhadap Aplikasi EOR (Enhanced Oil Recovery)
Abstrak: Application of MES (methyl esther sulfonate)-based surfactant for EOR (enhanced oil recovery) process in Indonesia has very good prospect. Corrosion rate testing is needed in EOR to prevent oil production failure due to corrosion of metallic materials. The aim of this research was to determine the corrosion rate of various metallic materials (201 stainless steel, 304 stainless steel, 316 stainless steel and metal galvanist) due to contact with MES-based surfactant solutions; and to select the most economical metal material to be applicated on surface facility of MES-based surfactant injection. The corrosion rate of various types of metal in solution formulations MES is measured with weight loss method. The results show that the rate of corrosion on the dilution process is high. While in the other hand, corrosion rate in gradual mixing without dilution method is smaller than in dilution method. The corrosion rate on all tested metals were still below 0,127 mm/year or lesser than allowed standard rate of corrosion for equipment and machinery used in oil and gas drilling.
Keyword: Enhanced Oil Recovery, Surfactant of Methyl Ester Sulfonate, Corrosion Rate

Judul: Studi Kelayakan Pendirian Industri Surfaktan Metil Ester Sulfonat Berbasis Minyak Kelapa Sawit (Studi Kasus : Untuk Aplikasi Enhanced Oil Recovery)
Abstrak: One of the solutions to increase the crude oil production is to implement the technology of Enhanced Oil Recovery (EOR) by using Methyl Ester Sulfonate (MES) surfactant. The purpose of this research is to study the feasibility for establishing a palm oil MES surfactant industry. The market share for the MES surfactant produced is an oil field that needs 18 tons surfactant/day. The capacity of the MES surfactant industry understudy is 20 tons MES/day locating at PT. Mahkota Indonesia, Jakarta. The investment required is about 29 billions rupiah that consist of fixed capital investment of 18 billions rupiah and working capital of 11 billions rupiah. The result of feasibility indicates that this MES surfactant industry is feasible to be built if there is establishment a chemichal flooding formulation company. The investment criteria show that Net Present Value is Rp. Rp 19.420.228.000, Internal Rate Return is 22%, Benefit/Cost Ratio is 1,53, and Pay back period is 5 years over 4 months. The sensitivity analysis shows that Industry feasible to build if the maximum increase of transaction value of dollar to rupiah is equal 7,7%, the maximum of decrease of selling price MES is equal 4,5%, and the maximum of decrease of production capacity is equal 70 %. The break even point analysis shows that at the first year must be produced at least 2.118 ton. The exchange rate risk shows that The appreciation of rupiah increase profit and asset eventhought the depereciation of rupiah decrease profit and asset.
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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