Judul: Nanomagnetit sebagai peningkat sensitivitas elektrode pasta karbon untuk analisis iodida secara voltammetri siklik
Abstrak: Salah satu cara untuk meningkatkan sensitivitas dalam teknik voltammetri siklik adalah dengan menambahkan suatu katalis. Katalis yang digunakan dalam penelitian ini adalah nanomagnetit (Fe3O4). Nanomagnetit disintesis secara hidrotermal dari FeCl3 sebagai sumber besi, natrium sitrat sebagai reduktor, dan urea sebagai sumber basa. Pencirian dengan difraktometer sinar-X dan mikroskop elektron payaran-spektroskopi dispersif energi menunjukkan magnetit merupakan hasil utama sintesis dengan ukuran partikel rata-rata 68 nm. Nanomagnetit tersebut digunakan sebagai pemodifikasi elektrode pasta karbon (EPK). Analisis voltammetri terhadap iodida 1 mM pada selang potensial 0–1.2 V dalam elektrolit KCl menghasilkan dua pasang puncak reduksi-oksidasi (redoks). Hubungan yang linear antara komposisi magnetit, kecepatan payaran, dan konsentrasi iodida terhadap intensitas arus puncak yang dihasilkan menunjukkan nanomagnetit dapat berperan sebagai katalis reaksi redoks iodida. Nanomagnetit berhasil meningkatkan sensitivitas EPK dalam pengukuran iodida, 10 kali lipat pada reaksi oksidasi, dan 7 kali lipat pada reduksi.
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Judul: Kinerja Elektrode Pasta Karbon Termodifikasi Nanomagnetit pada Teknik Voltametri Siklik
Abstrak: The performance of nanomagnetite-modified carbon paste electrodes (CPE) are influenced by the characteristics of nanomagnetite. This study determined the performance of a CPE modified with nanomagnetite synthesized by hydrothermal technique from FeCl3, urea, and sodium citrate at 200 °C for 3 hours. The electrode performance was determined by cyclic voltammetry technique by using iodide as analyte in KCl as supporting electrolyte at potential range of 0.0 to 1.2 V. Voltammetric analysis provided two pairs of oxidation and reduction peaks, both of them quasireversible. Nanomagnetite improved the response of iodide oxidation peak current 1.4 fold compared with the unmodified CPE. The electrode sensitivity was 16.04 mA/mM, the detection limit was 0.0462 mM, and the quantitation limit was 0.154 mM. The electrode selectivity was still good until 10- times addition of interference ion. The linearity of correlation of iodide concentration with oxidation peak current was good as well. However the electrode current response decreased after being stored for a month. Overall, the electrode performances were not as good as CPE modified with nanomagnetite synthesized for 12 hours previously reported
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Judul: Pengelolaan Lanskap Perumahan Danau Bogor Raya Lingkup PT Bogor Raya Development, Kota Bogor, Jawa Barat
Abstrak: Bogor Lakeside management under a large developer, namely ASIA PACIFIC (ASPAC) group which have renamed to PT Bogor Raya development was trusted to develop this area since 1989. Settlement provides many facilities to support of occupants. Management in this residence is the planning and design undertaken by division proyek and design. In creating the characters of the space, Bogor Lkeside residence comprises reception space, residential, and commercial space. In keeping with the landscape that has been awakened, maintenance of the landscape environment Bogor Lakeside managed and supervised by Estate Manager. Maintenace process at Bogor Lakeside executed by the contractors and in house (developer). Estate Manager gain financial revenue from the environment maintenance fee. Environmental maintenance fee fund covers the cost of security, cleanliness, and landscaping, and lightning environments. The most important thing in landscape management is maintenance. Landscape maintenance is devided into two which is maintenance of ideal and physical maintenance. Overall landscape management in Bogor Lakeside has gone well enough but still needed some other maintenance alternatives to create sustainability.
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