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
Keyword: 

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.
Keyword: 

Judul: Pengaruh Infeksi Haemoproteus columbae (Kruse, 1890) Pada Burung Merpati Dan Cara Penanggulangannya
Abstrak: Haemoproteus columbae merupakan paras it yang menyerang sel-sel darah merah burung rnerpati. Siklus hidupnya kompleks dan dapat dibagi menjadi dua yaitu siklus hidup asexual terjadi delam tubuh burung merpati dan siklus hidup sexual terjadi dalam tubuh lalat dari famili Hippoboscidae sebagai vektor. Stadium yang nampak dalam peredaran darah perifer hanyalah garoetosit yang dapat dibedakan menjadi dua yaitu gametosit jantan (mikrogametosit) dan gametosit betina (makrogametosit).
Keyword: