Judul: Use of waste aluminium industry as a raw material of polyaluminium chloride in decreasing turbidity of textile industry waste
Abstrak: Polyaluminium chloride (PAC) is a coagulant that can be synthesized from aluminium metal industrial waste by utilizing its aluminium content. In this study, PAC was successfully synthesized from such waste. Textile waste coagulation with PAC produced here were studied and compared with the coagulation with a commercial PAC. This study was initiated by AlCl3 monomer synthesis, continued with polymer formation, PAC assaye and characterization by FTIR spectrophotometer. The FTIR spectra exhibits hydroxyl, carbonyl, Al, and Cl absorption bands. The PAC was focused on its capability to decrease turbidity level. It was measured in 5 replicate with the result of 96.50% in average as compared to 97.23% for the commercial PAC. These data showed that the commercial PAC is better than PAC product in decreasing turbidity.
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Judul: Sintesis Polialuminium Klorida Berbahan Dasar Bauksit sebagai Koagulan
Abstrak: Bauxite is a metal resource with the total abundance of 3.47 billion tons in Indonesia in 2011. Bauxite has aluminium content about 45-65%, it makes bauxite has potency as the source of coagulant based on aluminium, polyaluminum chloride (PAC). The synthesis method used for producing PAC was partial hydrolysis using HCl 33% with polymerization times of 24 hours. In this research, characterization of PAC synthetic referring to SNI Quality Requirements 06-3822-1995 with observe the content of aluminium oxide levels, the content of Cl−, pH, spesific gravity, and basicity. This research also examined PAC capability to decrease turbidity in textile waste. Performance test of the coagulant on some textile industry waste water had been tested at pH 6, 7, 8, and 9. Result showed that the best PAC synthetic decreased artificial turbidity to 99.24% at pH 8 with dosage of 1 mL. The same dosage decreased the turbidity in textile waste up to 97.04%.
Keyword: bauxite, coagulant, polyaluminium chloride, textile waste.

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