Judul: Pengembangan Mesin Pemanen Nilam Bertenaga Mini Tiller
Abstrak: Harvesting is the final activity of the production process in the field and the determining factor for the next process. Patchouli harvesting in Indonesia is still done manually. Manual harvesting require more labor with low working capacity. Increased work capacity and cost efficiency can be improved by integrating two activities at once, namely harvesting and chopping using an integrated machine. By integrating two tool activities into one activity, it is hoped that it will reduce work time and costs. Through this innovative way, in addition to increasing performance, it is also more efficient in the use of resources (labor and fuel), which in turn will provide much greater benefits for farmers. The general aim of this research was to produce a prototype of a patchouli harvesting machine that is combined between cutters and choppers using a mini tiller power source. The specific objectives were to obtain the optimum chopping size to produce the best patchouli oil yield and quality, to obtain the right drying type to produce the best patchouli oil yield and quality, to obtain data on the technical characteristics of the patchouli plant, to obtain performance data of the patchouli chopping machine, to obtain data on the power requirements of the harvesting machine of patchouli with power availability from the mini tiller. The scope of research activities includes activities to answer and solve problems that have been identified and formulated. There are 4 stages carried out in this research. These stages consist of: 1) characterization of the yield and quality of patchouli oil based on the size of the chop and the type of drying; 2) measurement of the technical properties of patchouli; 3) design and evaluation of the chopping unit; 4) patchouli harvesting machine design. Characterization of the yield and quality of patchouli oil was carried out by experimental methods. The results of the quality analysis are adjusted to SNI. The results obtained indicate that: First, there is an effect of the type of drying treatment and the size of the pieces on the yield of patchouli oil. The highest yield of 2.45% was obtained from the drying treatment after chopping at a size of 7 cm (R1P1). This is because the size of the material is smaller, the more cells are broken so that the wider the contact area between the material and the solvent and also with drying, the cell walls will open and the more easily penetrated by hot steam, causing more oil when distilled. Second, whether or not there is an effect of the type of drying treatment and the size of the chopping on the quality of patchouli oil produced. Parameters that have no effect are seen in color, specific gravity, solubility in alcohol, and refractive index. This is because the content of hydrocarbon compounds and oxygenated compounds is still extracted and the amount remains dominant so that the quality parameter values tend to be the same because these compounds have a great influence on the quality value. Parameters that have an effect on acid number, ester number and patchouli alcohol, especially for optical
Keyword: machine of patchouli harvester, quality of patchouli oil, chopping of   patchouli

Judul: Analisis kinerja dan efisiensi energi prototipe alat penyulingan untuk industri kecil minyak nilam
Abstrak: Patchouli oil is high value essential oil of Indonesia that is produced by the steam distillation process from patchouli plants (Pogostemon cablin benth). As an export commodity, patchouli oil is quite substantial to fulfill the world demand in perfumery, cosmetic and pharmacy industries. Patchouli oil has always been possessed an increasing world market in spite of facing hard competition and nontariff barrier in the world trade. Therefore it needs to increase continuously the productivity and efficiency of essential-oil agroindustries. Distillation process for patchouli oil in small scale in general still represent simple technology process with equipments which are made from corrosive material. The most common method of essential oil production is water and steam distillation and conducted only based on experience so that the efficiency is usually low. Therefore this research evaluate aimed to the efficiency both kohobasi system and non kohobasi system. The objective of this research were to study and examine the performance of distillation equipment, analyze energy efficiency of distillation system prototype and analyze the quality of patchouli oil. The distillation method of 37,5 kg of patchouli plants was water and steam distillation with kohobasi system and non kohobasi system for 8 hours period. The distillation equipment to produced patchouli oil were retort with furnace, condenser and separator. This research used biomass energy such as fire woods as fuel. Furnace performance analysis based on several parameters which were surface area of heat transfer, woods burning process and the usage of fuels. The wide surface of heat transfer on retort is 1,70 m2. Distillation process with kohobasi system used dry fire woods of 143,32 kg and non kohobasi system used 138,2 kg of dry firewoods. The energy from firewoods used for boiling dan vaporize water in retort. According to the result, in kohobasi system the energy is needed to boiling and vaporize the water into steam is 644,51 MJ and the energy from firewoods is 2.579,85 MJ. The retort efficiency at that condition is 25 %. In non kohobasi system the energy is needed to boiling and vaporize the water into steam is 572,24 MJ and the energy from the fuel is 2487,6 MJ. The retort efficiency at that condition is 22,99 %. Retort performance bases on several parameters like bulk density, distillation rate and steam penetration. Bulk density for kohobasi system was 0,09 kg/l and 0,096 for non kohobasi system. Distillation rate for kohobasi system was 0,74 l/hour and 0,63 for non kohobasi system. Condenser efficiency for kohobasi system is 79 % and 99,26 % for non kohobasi sytem. The difference efficiency between kohobasi sytem and non kohobasi system is influenced by cold water flows. Cold water flows continuously in non kohobasi system result in higher efficiency than in kohobasi system. Average distillate temperature for kohobasi system was 31,56 °C and 30,35 °C for non kohobasi system. The yield of patchouli oil for kohobasi system was 2,29 % (dry basis) and 2,2 % (dry basis) for non kohobai system. The quality of patchouli oil produced by kohobasi system and non kohobasi system is quite comparable, the oil has specific
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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