Judul: Pendugaan Umur Simpan Keripik Salak
Abstrak: Salak (Salacca Edulis Reinw) is one of the horticultural commodities that still have big potential to be explored and developed in Indonesia. Indonesia as a tropical country provides a good condition of land and weather to grow salak. This condition makes salak grow easily in Indonesia. In the oher hand, this mass production of salak become a new problem itself. The mass production of salak make an excess amount of salak distributed in the market although the market itself can’t afford this huge amount of salak. Therefore, salak become wasted and become priceless. Agroindustry as a concept of adding a value to agricultural commodities trough technology become te best solution when facing this salak problem. To prevent the decreasing value of salak, salak can be proceed to fruit chips known as salak chips. Salak chips is categorized as dry food that have a small amount of water humidity. So even in shelf, salak chips have a longer shelf life than salak fruit. The purpose of this research is estimating the shelf life of salak’s derivative product which is salak chips. The process of making salak chips start from the frying stage. In order to pretend the composition and the taste of salak chips, vacuum frying is used in this process. After fried, salak must be packaged with the suitable packaging to provide a longer self life of salak chips. In this research, the estimating of salak chips shelf life will be divided in three threatment of packaging which are PP (polyprophylene), almunium foil, and laminated Plastic. Besides the threatment in different packaging, this research also estimating the shelf life of each packaging in three different temperature wich are 30°C, 35°C, and 40°C. In estimating the shelf life of this salak cips, there are several parameters used wich are water humidity, hardness, crisp, organoleptic test, and FFA. The result of this experiment shows that alumunium foil is the best packaging for salak chips because alumunium foil has the lowest transmission rate of water and oxygen.
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Judul: Proses Pengolahan Asinan Salak Pondoh (Salacca edulis Reinw.)
Abstrak: Sallacca edulis Reinw. (pondoh snakefruit) is one of Indonesia’s tropical fruits commodities. It have character easily damage and short shelf life. However, the level of production snakefruits keeps increasing from year to year. Pickle as an alternative process for extend added value of salak. Water activity is important factor that influence shelf life of salak. The stage is determination the concentration of salt and pickle solution (sugar and vinegar). The results of chemical and physical analysis from the research showed the best concentration of salt and pickle solution is salt 12%, sugar 17%, and vinegar 3.5% with parameter the hardness is 18.25 mm/g.sec, vitamin C 0.0023 (mg/100 g), content of acid 0.015 (ml NaOH 0.1 N/100 g), value sensory of taste 4.026, dan water activity is 0.935. The value of water activity showed the formula not effective to prevent growth destroyed bacteri, yeast, and mold at salak pickle.
Keyword: shelf life, pickle, water activity

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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