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: Pengaruh Pelarut pada Rendemen Sintesis Zink bis(dibutil ditiofosfat)
Abstrak: Lubricant additives used in Indonesia are still imported. Zink dialkyldithiophosphate (ZDTP) is a multifunctional oil additives, works as an antioxidant, antiwear, anticorrosion, and antiscuff. Synthesis of ZDTP has been widely performed and several methods have been developed. The method used in this study was relatively easy and simple, and the reagents were relatively easy to obtain. Various organic solvents were used in the synthesis, namely n-heptane, diethyl ether, and chloroform. Zink bis(dibutyl dithiophosphate) yield in all three solvents did not differ markedly, 97%, 92%, and 98%, respectively, with reaction time of 12 hours each in both steps. Functional group characterization of Zink bis(dibutyl dithiophosphate) using Fourier transform infrared spectrophotometer showed similar absorption bands for all three solvents. The high performance liquid of chromatography analysis results showed that the retention time of Zink bis(dibutyl dithiophosphate) synthesized using n-heptane, diethyl ether, and chloroform were similar to that of commercial authentic ZDTP.
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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