Garbage Trucks Routing in Surabaya

Garbage is produced daily in Surabaya. This work aims to find the effective garbage-collecting route in order to free Surabaya from garbage pile. Several factors needed to be examined are existing garbage colleting system and transportation time by traffic condition. Using this information, a model of Vehicle Routing Problem is developed. The model is called Time-dependent Vehicle Routing Problem with Multiple Trips and Intermediate Facility (TDVRPMTIF).Routes are applied to 70 trucks for 97 Temporary Dumping Site (TPS) in Surabaya, which consists of 19 locations in Central Surabaya, 15 locations in West Surabaya, 15 locations in North Surabaya, 36 locations in East Surabaya, and 12 locations in South Surabaya. The completion of garbage collection route TDVRPMTIF is using sequential insertion algorithm in 3 variants working time, 8-hours, 9-hours and 10-hours. These 3 variants working time do not produce less total routes assigned to the truck. This indicates Surabaya’s garbage collection have insufficient quantity of trucks to complete the problem.Several alternatives are proposed to solve the problem. First alternative is maintaining 8-hours working time and adding 11 trucks to complete the task. Second choice is adjusting the working time to 9 hours with the addition of 7 trucks. The third one is optimizing the existing 70 trucks with 10-hours working time

Choosing Bio Ethanol Fermentation Process Combination with Two Levels Full Factorial Design Method

The reduction of oil energy reserve makes fuel increased in price. Therefore, alternative energy as a substitute to save fuel is needed. One of the alternative energy is bio fuel, and one of the bio fuel types is bio ethanol. The purpose of this research is to determine the best factors and level combination on bio ethanol fermentation process, in order to made bio ethanol with higher content. Cassava is used as the raw material of bio ethanol making process. This research was conducted using Two Levels Full Factorial Design method. Factors which are studied are the amount of urea fertilizer NPK (fertilizer) type, the amount of NPK, the amount of yeast, the amount of alpha amylase enzyme, and the amount of glucoamylase enzyme. Data was analyzed using ANOVA test, main effect plot, and interaction effect plot. As a result, type of NPK, amount of NPK, amount of alpha amylase enzyme, and amount of glucoamylase enzyme are factors that have a significant effect on the bio ethanol fermentation process. The best combination for this experiment is the amount of urea: 4.88 grams, type of NPK: 20/9/15, the amount of NPK: 1.4 gram, the amount of yeast 10 grams, the amount of alpha-amylase enzyme: 1.5 milliliter, and the amount of glucoamylase enzyme: 1.35 milliliter

Pembuatan Biogas dari Kotoran Sapi dengan Metode Taguchi

The cow manure can be used for making fertilizer or biogas. The objective of this research is to find the best combination of factors and levels, for improving the quality of biogas, which can be used in the pasteurization process of milk production. A study case is done at a milk industry in the Middle Java province. Design of experiment with Taguchi method was used to find the best combination, for producing biogas with high methane percentage. The conclusion is made based on the analysis of mean and variance (signal to noise ratio) of the experiment’s response. As a result, the best combinations are the ratio of grass and maize plant is 1 : 0, without cutting process and they are given twice in a day1) the composition of biogas’s making is 1 liter of water for 3 kilograms cow manure2) the amount of bio starter is 6 milliliters for every 30 kilograms biogas dough3) and the food composition for a cow is 0,04 kilograms mineral, 0,03 kilograms sugar palm, 12 kilograms bran, and 18 kilograms tofu dregs4)