Judul: Penambahan magnesium berlebih dalam menghasilkan silikon murni dari sekam padi sebagai bahan semikonduktor
Abstrak: Rice is one of the most important cultivated plants in human civilization. Rice is also one of the main carbohydrate source the majority of the population in Indonesia. Central Statistics Agency (BPS 2012), estimates that in 2012 rice production reached 68.59 million tons, up by 2.84 million tonnes (4:13%) than in 2011. Seeing this, then it will appear in the form of agricultural waste rice husk. Most of the waste generated from the processing of rice had only burned or thrown away (Azadi et al 2010). Utilization of rice husk furnace developed by IPB since 2007, generating more waste in the form of waste rice husk (Irzaman et al 2007). Rice husk charcoal is known to contain at 95.14% silicon dioxide (Supaman et al 2010) and has the potential to produce pure silicon with a rate 40.78% (Hikmawati 2010) and 42.29% (Ahmad L 2012). This study aimed to examine the characteristics of silicon powder obtained from rice husk by chemical reduction method, which reduces the silicon dioxide using magnesium (Mg) powder to vary the ratio of the amount of silicon dioxide with magnesium and washing with a solution of HCl in the purification. Silicon dioxide and silicon obtained will be analyzed using X-Ray Difraction (XRD), Scanning Electron Microscope-Energy Distersive X-Ray (SEM-EDX), LCR meter and I-V meter. Manufacture of silicon through three (3) phases, husk charcoal, silicon dioxide and silicon. Husk charcoal through several stages. At first the rice husk is dried with the aid of sunlight with the purpose of accelerating the combustion process. Then the rice husks were weighed at 5000 grams (5 kg), entered into a husk furnace and continued with the process of burning, then the rice husk charcoal weighed. In this process produced rice husk for 1440 grams (1.44 kg). Rice husk as much as 40 grams put in porcelain dish and baked in a kiln at a temperature initially 400 °C for 2 hours, subsequent heating to temperatures of 1000 °C for 1 hour with the temperature rising rate setting by 1 °C/minutes and 5 ° C/minutes. After the ash obtained by burning weighed, then washed rice husk ash using hydrochloric acid (HCl) 3% technical which 12 mL of HCl 3% for 1 gram of technical rice husk ash, then heated over a hotplate with temperature settings 200 °C and stirred with magnetic stirrer at a speed of 240 rpm for 2 hours. Subsequently washed with hot distilled water (temperature of about 90-100 °C) repeatedly until acid-free (tested with litmus paper), and then filtered through ash-free paper. Screening results (residue separated from the filter paper) is inserted in the porcelain dish is then heated in a furnace at temperatures of 1000 °C for 1 hour with a temperature rise of 1 °C/minutes and 5 °C/minutes until the silicon dioxide remaining white. The samples were cooled in the furnace and weighed, then the result is tested SEM-EDX, LCR meter and I-V meter (Ahmad L 2012). The next process is to get silicon, silicon dioxide mixed with magnesium powder with a reductant that vary the ratio ranging from ratio
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Judul: Pengembangan Ekstraksi Silikon Sekam Padi untuk Semikonduktor
Abstrak: Indonesia is a country with rich natural resources. One of the natural resources in this country is a waste rice husk. Waste rice husk contains silica which is used as raw material for producing silicon. This study aims to obtain silica for use as a producer of silicon materials. Rice husk waste contains 39.04% of silicon. Rice husk is burnt with the variation rate of temperature rise in 1, 3, 5, and 7 ° C / min. Ash content with fewer impurities found in the burning rate of rise of temperature of 1 ° C / min. The ash then washed and made the process of mixing with the variation at 300, 400, 500, and 600 rpm. Silica is processed at a speed of 600 rpm, then burned at a pace of temperature 1 ° C / min resulted in purity silica (SiO2) at 99% and 0.22% silicon has been formed. Silica which has been obtained then reducted using Magnesium (Mg) in the combustion temperature of 650 ° C. silicon obtained by EDS (energy dispersive X-ray) analysis still contained impurities Magnesium. This result is not up to the necessary levels of percentage of silicon.
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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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