Judul: Pengaruh Jenis Alkohol pada Rendemen Sintesis Zink Dialkilditiofosfat
Abstrak: Zinc dialkyldithiophosphate (ZDTP) is an organometallic compound used as an additive in lubrication system. ZDTP was composed of Zn atoms with two dialkyldithiophosphoric acid. The usefulness of ZDTP depends on alkyl content, as for antiwear, antioxidant, anticorrosive, and restrain extreme pressure. ZDTP can be synthesized through two step. Firstly, dialkyldithiophosphoric acid (ADTP) was made from diphosphorus pentasulphide (P2S5) with alcohol. Second, ADTP was reacted with zinc oxide (ZnO), producing ZDTP. The suitability of the ZDTP has been varied by using fourier transform infrared spectrophotometer (FTIR), atomic absorption spectrophotometer (AAS), and high performance liquid chromatography (HPLC). The yield of ZDTP 1-4 were 13.88%, 43.50%, 97.29%, and 77.35%, respectively. The result of FTIR characterization in ZDTP showed P-O-C group absorption at 1000􀵆980 cm-1, PS bond absorption at 650􀵆550 cm-1, and Zn-S bond absorption at 400􀵆300 cm-1 . AAS was used to determine the content of Zn in ZDTP 1-4 with the value of 16.16%, 28.82%, 11.81%, and 17.36%, respectively. Verification of compliance indicators ZDTP were measured by comparing the retention time and HPLC chromatograms. It showed that the measured ZDTP had similar retention time with and authentic commercial ZDTP on the same absorption band despite, low concentrations.
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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 Suara Song Burung Kenari (Serinus canaria) Postur Besar dan Kecil.
Abstrak: Burung kenari (Serinus canaria) memiliki nyanyian yang sangat bervariasi dengan durasi yang panjang dan merupakan tipe burung bernyanyi open learners. Penelitian ini bertujuan menganalisis karakteristik suara song burung kenari (Serinus canaria). Penelitian dilakukan pada bulan April sampai Juni 2017 di Bogor, Jawa Barat. Perekaman suara song terhadap 12 ekor burung kenari jantan dilakukan dengan menggunakan mikrofon Sennheiser ME66 dan alat perekam Sony PCM-D50. Burung kenari yang digunakan merupakan burung yang pernah mengikuti kontes burung kicau dan memiliki predikat juara kontes burung. Amplitudo, durasi suara, frekuensi, dan volume suara burung dianalisis dengan menggunakan software Raven Pro 1.4. Data tersebut selanjutnya dianalisis deskriptif. Hasil analisis suara menunjukkan bahwa burung kenari memiliki banyak syllable, suara song rapat dan tidak terputus-putus, tempo yang cepat, dan adanya pengulangan suku kata pada setiap suara song. Burung kenari postur kecil memiliki rataan durasi lebih panjang dibandingkan dengan kenari postur besar, tetapi burung kenari besar memiliki rataan max amplitudo, average power, max power, min amplitudo, peak amplitudo, dan peak frekuensi.
Keyword: karakteristik suara (song), kenari, syllable