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: Pengaruh Cara dan Lama Pengeringan Terna Nilam Terhadap Rendemen dan Mutu Minyak Nilam
Abstrak: One of problems of patchouli oil industry in Indonesia were the yield and the quality of patchouli oil that were still low. One of factors that affect the yield and the quality of patchouli oil is drying of patchouli herb before distillation. The research aim are to determine the effect of drying method and drying time on the yield and the quality of patchouli oil. The experimental design used in this study was factorial completely randomized design of (3 x 4) factosr with two replication. Factors used were the method of drying (dried patchouli without sunlight for 9 days, patchouli were dried in the sun for 2 hours and then aerated for 8 days, patchouli were dried in the sun for 4 hours then aerated for 5 days, patchouli were dried in the sun for 6 hours and then aerated for 4 days) and placement during drying (floor, shelf and hanging). Method of drying and drying time significantly affected moisture content of patchouli herb, refractive index, specific gravity, acid number, ester number and solubility in alcohol of patchouli oil, but its did not give significant effect on the yield, color, and optical rotation of patchouli oil. The longer of drying time tends to cause bulk density, optical rotation, and acid number of patchouli oil are increase, but the water content, solubility in alcohol, and ester number of patchouli oil are decreases. The best treatment in this research was drying of patchouli herb on the shelf and dried in the sun for 4 hours then aerated for 5 days, with the yield of 2.99%, water content of 15.12%, oil color is yellow, bulk density of 0.9676, refractive index of 1.5090, optical rotation of (-) 57.78, soluble in alcohol 90% with a ratio of 1:4, acid number of 2.239, ester number of 13.141, and patchouli alcohol content of 39.54%.
Keyword: 

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.
Keyword: