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This research paper was designed to use a Linear programming technique, by the data collected from Rufaidah Yoghurt Processing Company. The company produces different sizes of yogurt milk ranging from 2 liters to 330ml per day. To maximize the profit, the Mathematical Tools (Simplex and Dual Simplex methods) were employed to find the optimal solution. The result shows that, the Simplex method performed better than the Dual Simple method in terms of number of iterations with aim to maximize the profit of the company. [ABSTRACT FROM AUTHOR]

Metals are bound to a different phase in sediment and that speciation reflects their bioavailability for an organism. The speciation of Cu and Ni in sediment in Benoa Bay, Bali was not well investigated. Thus, this study was aimed to determine Cu and Ni speciation in sediment from Benoa Bay, Bali and to assess their mobility. Sediment samples were collected from 11 observation points (stations) in Benoa Bay in March 2017. Modified BCR (Community Bureau of Reference) protocol was applied to extract different Cu and Ni species in the sediment namely metal associated with carbonate fraction (F1), iron/manganese oxide (F2), organic and sulfides (F3) and mineral (F4). The result revealed that Cu was dominantly associated with mineral (>50% of Cu in F4), therefore, Cu resembled the lithogenic origin. Opposite, Ni was associated with carbonate and iron/manganese oxide almost in all observation points indicating anthropogenic origin. Risk assessment code (RAC) was computed to determine the possibility of that Cu and Ni to be released. The computation of RAC indicated Cu was at low-risk level and Ni was at a medium to high-risk level to be released. However, the total Cu and Ni were below sediment quality guideline so the level of metals was at a minimum possibility to stimulate adverse effect to an organism. The spatial distribution of Ni in the bay reflected the anthropogenic source thus the activity should be well managed to control the contamination. [ABSTRACT FROM AUTHOR]

Adequate and safe railway line infrastructures as well as facilities are required to support the rail transport system in South Sumatra. The slope stability along railway line of Lahat-Lubuk Linggau South Sumatra were studied during landslide that occurred on January 23th, 2016. The landslide occurred on the mouth of railway tunnel in Gunung Gajah Village, Lahat District that causing the railway transportation system had to be stopped for a few days. A comprehensive research was conducted to analyze the causes of the landslide and to identify other landslide risky areas along the railway line Lahat-Lubuk Linggau. The research activities included surveying, sampling, laboratory testing, investigating condition of geology, geotechnics, hydrogeology/hydrology, morphology and land use. The factors that cause landslide in the past studies were found to be morphology, structural geology, physical and mechanical characteristics, hydrogeology, hydrology, external forces (train vibration, earthquake). Results back analysis of slope stability when the landslide occurred showed that the value Safety Factor (SF) = 1, angle of friction = 0° and cohesion = 0.49 kg/cm2 (49 kPa). Based on the observation and analysis of the condition of the morphology and orientation of the structure of the rock layers, there was a location prone to landslide (labile) in the surrounding area of the landslide. Mitigations to potential landslide in adjacent area were building a retaining wall, draining channels and shortcrete at the rock wall after landslides and maintaining the land use around the slopes. [ABSTRACT FROM AUTHOR]