Judul: Penurunan Mutu Oil Spill Dispersant Dietanolamida - Metil Ester Sulfonat Selama Penyimpanan
Abstrak: Karakteristik oil spill dispersant dapat dipengaruhi oleh jenis kemasan dan suhu penyimpanan yang dapat memicu adanya reaksi yang menyebabkan kerusakan fisik-kimia sehingga kemampuan OSD untuk mendispersikan minyak menurun. Tujuan penelitian ini adalah untuk mengetahui pengaruh jenis kemasan dan suhu penyimpanan terhadap karakteristik OSD selama penyimpanan. Penelitian dilakukan dimuali dengan pembuatan OSD, pengemasan dala botol kemasan high-density polyethylene (HDPE), botol polyethylene terephthalate (PET), dan jar terbuka sebanyak 500 mL, penyimpaman pada suhu kamar dan 40oC, selama 8 minggu. Perubahan karakteristik OSD selama penyimpanan diamati adalah viskositas, densitas, tegangan permukaan, pH, jumlah bakteri dan penampakan visual. Rancangan penelitian menggunakan rancangan acak lengkap. Hasil penelitian menunjukkan perubahan karakteristik OSD yang nyata terhadap jenis kemasan dan suhu penyimpanan. Selama penyimpanan, OSD mengalami perubahan secara fisik secara visual meliputi terbentuknya endapan, droplet yang lebih besar, atau padatan yang mengapung. Perubahan karakteristik OSD menunjukkan terjadinya peningkatan tegangan permukaan dan viskositas, penurunan pH, kontaminasi mikroba, akan tetapi densitas relative stabil. Kondisi penyimpanan terbaik diperoleh pada kemasan HDPE dan penyimpanan suhu ruang, dan setelah dihitung ternyata memiliki kemampuan daya simpan selama 92 hari.
Keyword: DEA, HDPE, MES, oil spill dispersant, pengemasan, penyimpanan, PET

Judul: Formulasi Oil Spill Dispersant (OSD) dengan Bahan Baku Surfaktan Metil Ester Sulfonat (MES) dan Dietanolamida (DEA).
Abstrak: Environmental pollution which caused by the oil spill can be dealt with the physical, chemical and biological treatments. Physically treatment was done by isolate the petroleum quickly before spread to the environment. Meanwhile, chemical treatment was relatively short to manage oil spill, but this treatment had disadvantage cause by application of chemicals which less environmental friendly. Of the chemical treatments is oil dispersion by using oil spill dispersant (OSD). OSD is a product with composition of some chemicals and surfactants that aims to disperse the waste oil to be degraded in the environment. Based on previous research, the modern OSD composition consisted of nonionic and anionic surfactants, so dietanolamide (DEA) as nonionic surfactant and methyl Ester Sulfonate (MES) as anionic surfactant were used in this research. This research aims to produce formulated surfactant as an oil spill dispersant (OSD) which consists of DEA, MES and solvent and then tested on a simulation of marine pollution. The research was divided into three steps: the first step was synthesis of MES and DEA as raw material of OSD formulation, the second step was formulation process of OSD by mixing the two raw materials at variation of concentration and volume ratio. This step aims to find the best formulated OSD. The third step was a testing the performance of the best formulated OSD by oil spill simulation. In the first step, the raw material of DEA and MES were produced at an optimum conditions of previous studies. In the second step, characterization of OSD product by analyzing of emulsion stability, density, surface tension, viscosity and pH. Some of these parameters were used to determine the best formulation of OSD. The best formulation of OSD was conducted in performance test in simulated oil spill using 10ml crude oil in 1 L sea water media and then it to be dispersion. The dispersion oil in sea water were analyzed to chemical oxygen demand (COD), biological oxygen demand (BOD), total petroleum hydrocarbons (TPH), density, and pH. The formulation of OSD was made by mixing two surfactant solutions including DEA solution with concentration of 1, 2, 3, 4, 5 % and MES solution of 1, 2, 3, 4, 5, 10, 15 %. Both of surfactant solution were mixed with volume ratio of 1: 3, 1: 1 and 3: 1 at temperature of 50C for 60 min. The result showed that the best formulated OSD was at mixing of 3% DEA and 5% MES solutions with volume ratio of 1 : 3. The OSD product showed excellent stability (> 80%) with a good properties including density of 0.90 g/cm3, the surface tension of 25.59 mN/m, pH 9.1, and a viscosity of 131 cP. The performance test of OSD carried out by simulation of oil spill in sea water with application of ratio of volume OSD to volume oil spill. Addition of OSD was expected could increase to the dispersion of oil in sea water. The performance test of OSD showed that 2 mL OSD in 10 mL simulated oil spill (ration 0.2) capable to dispersing of oil at 85.75 %,
Keyword: DEA, MES, OSD, oil spill, surfactant

Judul: Determinant and Inverse of Skew Circulant Matrix with Fibonacci Numbers Entries
Abstrak: ... Entri-entri dari matriks skew circulant dapat diisi dengan berbagai barisan bilangan, salah satunya adalah dengan barisan bilangan Fibonacci. Tujuan dari penulisan karya ilmiah ini adalah mengkaji secara teoritis pembuktian untuk menentukan determinan dan invers matriks skew circulant dengan entri barisan bilangan Fibonacci. ... dst
Keyword: determinant, Fibonacci numbers, inverse, skew circulant matrices