Judul: Uji Struktur dan Sifat Listrik Silikon Dioksida dan Silikon dari Sekam Padi
Abstrak: Rice husk charcoal is known to contain 93.67% of silicon dioxide and has the potential to produce silicon. This study produced silicon dioxide and silicon, that had been tested for the electrical and structural properties. Incineration process of rice husk charcoal was performed in a furnace at a temperature of 400 oC for 2 hours and 1000 oC for 1 hour, with the increase rate of 5 oC/minute. The incineration yield then washed with HCl 3% (12 ml HCl 3% for 1 grams of rice husk ash), and heated using hotplate and magnetic stirrer, with a speed of 240 rpm for 2 hours at 200 oC. Furthermore sample washed repeatedly using hot distilled water until free of acid, then reheated in a furnace to produce silicon dioxide. Silicon dioxide produced approximately 5.6 to 6.8 grams of 10 grams of rice husk charcoal. The silicon dioxide then mixed with reductor (magnesium powder), using comparisons based on stoikhiometri, afterwards heated in a furnace for 1 hour with a temperature of 650 oC. Based on the results of XRD analysis, the crystallinity of silicon dioxide reaches 75.85 to 83.28% and silicon with value of 53.34%. XRD analysis showed that the silicon dioxide structure is tetragonal with lattice constants a = 12.45 Å and c = 111.77 Å, while the silicon has cube structural with lattice constants a = 5.27 Å. SEM results showed that the silicon dioxide has the smoother surface and the silicon had formed a crystal structure. EDX results for silicon dioxide of about 77.88 to 81.64% and silicon 42.29%. Analysis of electrical properties was performed using the LCR meter and I-V meter, and was known that the silicon dioxide and silicon have the characteristic of semiconductor, where the electrical conductivity of silicon has a value higher than silicon dioxide. The I-V curves showed that silicon dioxide is a diode, while the diode is a resistor.
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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: Infection Of Babesia Bigemina In Cattle And Methods Of Control
Abstrak: Babesia bigemina is the species which occurs mostly through out the tropics and subtropical areas. It gains access to the susceptible cattle through the bite of an· ig fected tick and penetrates an erythrocyte. The pathogenesis of B. bigemina is considered to be as highly pathogenic and may cause heavy mortality in susceptible stock. Infecied cattle rapidly become dull and listless and lose their appetite, the erythrocytes are destroyed resulting anaemia, icterus, emaciation, weakness, and a drop in milk production. Death and loss of productivity due to B. bigemina account for the economic loss.
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