Judul: Modifikasi Proses Penyulingan dengan Variasi Tekanan Uap untuk Memperbaiki Karakteristik Aroma Minyak Pala
Abstrak: Indonesia is one of the world’s biggest nutmeg oil producer which contributes to 72.2% of world production. This major market share must be maintained by continous improvement of nutmeg oil quality. One of the important factors determine the nutmeg oil quality is the composition of aroma compound. Thus, the research on studying the aroma component of nutmeg oil during distillation process was conducted. Inthis research, distillation process operation was modified by using direct steam method by gradually change the pressure. The experiments were divided into two stages.
Keyword: 

Judul: Peningkatan Kinerja Proses Penyulingan Minyak Pala Dengan Metode Uap Langsung
Abstrak: Nutmeg oil is one of Indonesian important export commodity. For the last six years (1996-2001), it's price in the word market has showed an inclined increasing. In 1999, the nutmeg oil price reached the average price of 26.18 US dollar/kg. In the beginning of 2000, the average price of Indonesian nutmeg oil in the world market returned to increase and achieved the average price of33.38 US dollar/kg. The market opportunity which is still prospective as well as the raw material availability become the fundamental aspect of the developing the nutmeg oil industry in Indonesia. For the time being, essential oil production existing in Indonesia is small scale industry. The common problem which found, was the long distillation duration which takes 48-52 hours for nutmeg kernel distillation and 72 hours for mace distillation. It caused the high consumption of energy/fuel. The condition was very contradictive to the energy prices which is always increase. In the other side, a sceintific point of view considering the optimum material size as well as the uniform vessel pressure distillation in each small sclae distillation factory is not yet being under attention. The objective of this work is to improve the performance of nutmeg oil distillation process by reducing the duration of distillation process. The specific objective is to find out the effect of material size and vessel pressure to the yield and quality of resulted nutmeg oil from the young nutmeg kernel and mace using direct steam distillation method. The size of nutmeg kernel observed in the experiment was categoried in fine, which was the output of 0.3 cm strainer hole diameter mill; semi rough, which was the output of 0.5 cm strainer hole diameter mill; and rough, which was the output of 1.0 cm strainer hole diameter mill. The distillation conducted of a vessel pressure of 0 atm gauge, with a duration of 12 hours. All experiment run was conducted twice. In second experiment stage, the vessel pressure was levelled to 0.5 and 1.0 atm gauge in order to provide a better process condition. This stage was conducted based on the nutmeg kernel size which given the highest yield as the consideration to determine the best atmospheric pressure in the vessel in perspective of resulting the highest nutmeg oil yield and meet the quality standard. All experiment run was conducted twice and with duration 12 hours The average water content of raw material used was 16.84 % (% v/w), while the average oil content of the raw material used was 17.58 % (%v/w, wet basis). The kernel size of 0.5 cm resulted the highest yield of oil compared to the two other kernel size, it has 12.98 % (% v/w, wet basis) or 11.65 % (% w/w, wet basis). As well as distillation rate in a period of two hours. At the end distillation process, the kernel size of 0.5 cm has succeeded to distill the nutmeg oil from the material in amount of 73.83 %. Thus, the kernel size of 0.5 cm was the best yielded material size compared to the two other material size
Keyword: 

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular