Judul: Kinerja Antikorosi Zink Diarilditiofosfat dengan Teknik Polarisasi Potensiodinamika
Abstrak: Zinc diaryldithiophosphate (ZDTP) is a lubricant additive that functions as antiwear, anticorrosion, antioxidant, and antifriction. The ZDTP function has been studied in this experiment by measuring its function as anticorrosion using potentiodynamic polarization technique. The highest ZDTP yield was 70%. The measurement shows that ZDTP has high corrosion inhibiton effectivity as proved by the optimum value of %IE in the concentration 1% of inhibitor solution of 84.45% with surface coverage of 0.84. Thermodynamic parameter shows corrosion spontaneity decreased due to the present of inhibitor. The value of activation energy in Cu metal corrosion process with the present of inhibitor was 52.32 kJ mol-1, the value is higher than the blank activation energy, i.e 31.47 kJ mol-1. This fact shows a decreasing corrosion rate with increasing minimum energy of reaction.
Keyword: Bogor Agricultural University (IPB), zinc diaryldithiophosphate, thermodynamics, inhibition effectiveness, activation energy

Judul: Kinerja Antikorosi Zink Dialkilditiofosfat Berdasarkan Studi Termodinamika dan Kinetika dengan Teknik Polarisasi Potensiodinamik
Abstrak: Zinc Dialkyldithiophosphates (ZDTP) is lubricant additives and has function as anti-friction, anti-wear, antioxidant, and anti-corrosion. ZDTP Performances as anti-corrosion is measured by potentiodynamic polarization technique. Three types of ZDTP were prepared, based on the alkyl chain length. The Measurement shows that ZDTP 8 has the highest corrosion inhibition affectivity as compared to ZDTP 4 and ZDTP 16. The inhibition affectivity of ZDTP 8 to metal Cu reaching 80% in the concentration 2% of inhibitor solution. This research result also explains the influence of alkyl chain length on the performance of ZDTP as anti-corrosion. Thermodynamic parameter verification shows corrosion spontaneity decrease by the present of inhibitor. Corrosion activation energy with present ZDTP 8 is 38.60 kJ mol-1, the value is bigger than blank activation energy namely 31.14 kJ mol-1. This phenomena shows that decreasing corrosion rate relate with increasing minimum energy of reaction.
Keyword: inhibition affectivity, kinetic, polarization, thermodynamic, ZDTP

Judul: Karakteristik Anatomi Skelet Kepala Buaya senyulong (Tomistoma schlegelii).
Abstrak: Buaya sepit atau senyulong (Tomistoma schlegelii) merupakan jenis buaya asli Indonesia yang berhabitat di sungai-sungai Sumatera, Kalimantan, dan juga pedalaman Sulawesi. Salah satu ciri khas buaya senyulong adalah bentuk moncong yang runcing dan sempit, namun hingga saat ini informasi mengenai struktur skelet kepala buaya senyulong sangat terbatas. Penelitian ini bertujuan untuk mempelajari karakteristik anatomi skelet kepala buaya senyulong yang dikatikan dengan fungsi dan perilakunya. Penelitian dilakukan secara eksploratif dengan melakukan pengamatan, pencatatan, dan pengambilan gambar dari skelet kepala buaya senyulong. Skelet kepala berukuran panjang 70 cm, lebar 29 cm, dan tingggi 17 cm dengan permukaan kasar pada os nasale, os frontale, os maxilla, os mandibula, os lacrimale, os jugale. Jumlah gigi pada buaya ini sebanyak 78 buah, terdiri dari 4 buah gigi premaxila, 16 buah gigi maxila, dan 19 buah gigi mandibula. Pada regio orbitalis ditemukan dua pasang fenestrae temporales yang berkembang baik. Fenestra supratemporale merupakan lubang oval yang membentang di sepanjang os parietale. Fenestra infratemporale berbentuk segitiga dan dibatasi oleh os squamosum, os postorbitale, os jugulare, dan os quadratum. Os mandibula hewan ini mempunyai symphysis mandibularis yang panjang yaitu garis yang melintang di corpus mandibulae. Secara fungsional ukuran symphysis mandibularis berkaitan dengan adaptasi hewan terhadap diet makan.
Keyword: kepala, moncong, Tomistoma schlegelii