Judul: Optimalisasi pemurnian silikon berbahan dasar arang sekam padi menggunakan reaktor tertutup
Abstrak: High silica (SiO2) concentration in charcoal rice husk could be used as silicon with 40-60% level of purity. Low purity is caused by the effect of oxygen involved in the reduction process. The aim of this research was to optimize reduction process of silica from charcoal rice husk to obtain silicon with high purity level. The optimization process of silica reduction was conducted in closed reactor using alumina and stainless steel tube with magnesium as reducing agent in mass ratio of SiO2 and Mg 1:1 and 1:2. The reduction products were leached by HCl 10% at the first step, and a mixture of 2M HCl and CH3COOH 25% at the second step. Silicon products were characterized by X-ray diffraction (XRD) and MATCH 2 program. In mass ratio of SiO2 and Mg 1:1, quantitative value of XRD (QXRD) silicon in alumina tube reactor (22%) was higher than that in the stainless steel tube reactor (16%). In alumina tube reactor, QXRD silicon in mass ratio of SiO2 and Mg 1:1 that value was lower than that of 1:2 (50%). The acid leaching process removed major impurities, such as MgO, Mg2SiO4, and SiO2. The highest purity of silicon was produced from alumina tube reactor with mass ratio of SiO2 and Mg 1:2.
Keyword: Bogor Agricultural University, silicon, silica, closed reactor, charcoal rice husk

Judul: Optimization of Excess Magnesium Addition and Heating Rate on Silicon Dioxide and Silicon Extraction Based Rice Husk
Abstrak: Indonesia is an agricultural country that produces rice sufficiently large. According to Central Agency on Statistics (BPS 2013) data, in 2012 rice production in Indonesia amounted to 69.05 million tonnes of milled rice, an increase of 3.29 million tonnes (5.00%) compared to 2011. Each tonne of rice containing 72% rice, 5% -8% bran and 20% - 22% husk (Muthadhi 2007). Seeing these data would appear a lot of agricultural waste,one of them is rice husk waste . Waste destruction process naturally progresses slowly (Nugraha and Setiawati 2006). Rice husk generated from most of the countries that produce rice just burned and disposed of as waste (Azadi et al. 2010). Rice husk, a waste product of the rice industry is rich in silica. (Kalapathy et al. 2000). Utilization of rice husk stove developed by IPB from 2007, produces another form of waste (Irzaman et al 2007). Rice husk charcoal from rice husk stove IPB, can be used to produce silica. The Silica resulting from the incineration process can be used as a source of silicon (Rohaeti et al.2010). This research is aimed to optimize of the speed of temperature increase (0.5 0C/menit and 1.5 0C/menit) to obtain high-purity silicon dioxide and optimization of addition of excess magnesium by chemical reduction method by comparing the amount of magnesium and silica (49: 60) to obtain high-purity silicon . Silicon dioxide and silicon obtained will be analyzed using Energy Dispersive X-ray (EDX) and FTIR Spectroscopy. Preparation of silicon through three (3) phases, husk charcoal, silica / silicon dioxide and silicon. Making husk charcoal through several stages. At first the rice husk is dried with the aid of sunlight with the aim of accelerating the combustion process. Then the rice husks were weighed at 4000 grams, entered into a husk stove and continued with the combustion process (Ahmad 2012), rice husk and then weighed. In this process produced husk charcoal at 1370 grams (34.25%). Rice husk charcoal as much as 60 grams put in of porcelain bowls and burned in a furnace at a temperature of 400 °C initially for 2 hours, subsequent heating to a temperature of 950 °C for 1 hour with a temperature increase rate setting of 0.5 ° C / min and 1.5 °C / min. After the ash obtained by burning weighed, then washed rice husk ash by using hydrochloric acid (HCl) 3% technical (12 mL 3% HCl technical for 1 gram of rice husk ash), and then heated over a hotplate with a temperature setting of 200 °C and stirred with a magnetic stirrer at a speed of 240 rpm for 2 hours. Subsequently washed with hot distilled water (temperature around 100 °C) repeatedly until the free acid (tested with litmus paper), and then filtered through ash-free paper. Screening results (residues separated from the filter paper) included in the of porcelain bowls and then heated in a furnace at temperatures of 1000 °C for 1 hour with the temperature rise and 5 oC/menit 1 oC/menit remaining until the white silica. The samples were cooled in the furnace and weighed, then the
Keyword: rice husk, silica/silicon dioxide, silicon,, FTIR.

Judul: Babesiosis pada kuda
Abstrak: Babesiosis pada kuda adalah penyakit menular yang di- sebabkan oleh Babesia caballi dan Babesia equi, yaitu pa- rasit protozoa perusak sel darah yang termasuk dalam genus Babesia. B. equi diduga oleh beberapa ahli termasuk dalam genus Theileria. Karena itu klasifikasi genus Babesia di- bicarakan dan siklus hidup B. caballi dan B. equi diulas. Kuda pada semua umur dapat terserang oleh dua parasite tersebut di atas. Tetapi kuda-kuda yang sudah dewasa (tua) lebih rentan jika dibandingkan dengan kuda-kuda yang masih muda. Kasus-kasus yang paling sering dijumpai adalah kasus-kasus yang bersifat akut walaupun kasus-kasus yang bersifat perakut, subakut dan kronik kadang-kadang terlihat. Serangan oleh parasit Babesia biasanya menyebabkan kerusаkan sel darah merah yang hebat sehingga kuda-kuda yang terserang menderita anemia hebat yang dapat menyebabkan kematian bila tidak segera diobati. Untuk mengatasi hal tersebut perlu dilakukan diagnosis yang tepat dan sedini mungkin. Diagnosis dapat dilakukan dengan cara memeriksa gejala-gejala klinik, preparat ulas darah, inokulasi hewan lain dan dengan mengadakan pemeriksaan secara serologik. Gejala-gejala klinik babesiosis pada kuda yang bersifat akut yang paling sering terlihat, ialah : nafsu makan menurun/hilang, lesu, bulu suram dan tidak mau bergerak. Kuda yang dilepaskan di padang rumput akan mengasingkan diri dan jalan sempoyongan. Faeces yang keluar berwarna cok- lat gelap, diselaputi lendir yang berwarna kekuningan dan urimenya berwarna merah tua. Temperatur tubuh meningkat menjadi 39.5 - 41°C dan pulsus meningkat. Terlihat dispnoe, perdarahan petechi pada mukosa membrana nictitans dan conjunctiva yang lebih pucat dari normal dan juga icteris. Kasus-kasus yang bersifat subakut gejala-gejalanya lebih ringan, tetapi bila tidak segera diobati maka gejala- gejala tersebut secara cepat menjadi hebat. Persendian lutut dan persendian gelang puyuh membengkak dan padanya ter- lihat oedema. Pada abdomen, dada dan kepala juga dapat di- temukan oedema. Gejala-gejala klinik yang terlihat pada kasus kronik adalah penurunan kondisi tubuh kuda secara progresif walaupun diberi makan yang banyak. Perubahan temperatur tidak jelas, nafsu makan berubah-ubah, icterus tidak jelas dan anemia mungkin hanya dapat dideteksi dengan menghitung sel darah merah dan kadar hematocrit…dst
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