IPTEK Journal of Proceedings Series
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Study of Treatment Process Improvement of Fecal Sludge in Surabaya City and Optimization for The Retribution Management
Get PDFIPLT Keputih is one and only fecal sludge treatment plant in Surabaya City. As mentioned on Perda No 1 Tahun 2016 Kota Surabaya, fecal sludge is one of the public services with current retribution cost of Rp. 15.000/m3. However, the retribution cost does not cover all fecal sludge treatment cost, rather merely as indicator for public participation to treat their fecal sludge. Throughout 2014-2018, the number of treated fecal sludge in IPLT Keputih is 134.537,52 m3 while the fecal sludge potential is up to 2.756.146,5 m3. In order to increase public participation, it is necessary to review value and sytem of fecal sludge treatment and adjust it with local economic condition. In addition, to support the treatment potential, IPLT Keputih also needs some optimization in the retribution management. The method used in this study is started by collecting primary and secondary data about the treatment and retribution system. Laboratory test result will be the basic of process performance. After all data are complete, there will be some analysis based on the evaluation of process and operation, improvement process and operation recommendation based on process experiment, and retribution system optimization. To optimize the value of retribution and system, the optimal value of retribution and maximum service (treatment and desludging) is Rp. 12.000/month combined with PDAM retribution. This will in return increase public participation in fecal sludge treatment
The Use of PT Petro Kimia’s by-Product Gypsum as Fill Materials
Get PDFGypsum is a by-product of the Phosphoric Acid factory PT Gresik Petrochemicals; it is produced around 1,200,000 tons/year. In order to reduce the amount, an effort needed to use gypsum as fill materials. For this purpose, the problem needs to be considered is that gypsum should not contain substances that harmful to the environment and meet the fill materials requirements. In order to answer all these questions, chemical tests were carried out to determine its heavy metal content. Gypsum plasticity and its particle size distribution were determined by conducting Atterberg limit and sieve analysis tests. Compaction test and CBR test were also carried out to determine the density and its strength. Those results were then analyzed using "The Fifteen Point Method" to obtain a relationship curve between dry density (d) and soaked-CBR. This curve was important to determine the soaked-CBR that can be achieved by gypsum materials in the field with different compaction energy 90%, 95%, and 100% of maximum compaction energy. Chemical test result shows that all heavy metals content in gypsum material are far below the regulatory limit; therefore, it is safe for the environment. Besides, Gypsum is non-plastic (NP) material and it is classified as A-4 (AASHTO) or SM (USCS); it means that Gypsum is very good for fill materials and safe to the environment. In addition, the result from the Fifteen Point Method shows that the minimum soaked CBR value is 13% achieved by using 90% of maximum compaction energy with 30-40 % of water content. It means that the gypsum material can be used as selected fill material because it fulfils its requirement where IP10%
Development of Hesitant Fuzzy-Based Project Selection Method with Consideration of Benefits, Opportunities, Costs and Risks
Get PDFPT X, a power generation company, hasn’t been able to meet their target in the business development segment over the past few years. This is due to a problem detected in their Project Portfolio Management, in which PT X’s project selection method hasn’t considered the ambiguity nature of project’s information and risks. This study is going to develop a project selection method for PT X using MCDM (multi criteria decision making) with BOCR (benefit, opportunity, cost, risk) Concept to evaluate many criteria that need to be considered by the company, especially conflicting criteria such as benefit with cost and opportunity with risk. Not only that, hesitant fuzzy will be used because project itself has many uncertain or ambiguous information, so stakeholder will face difficulties in determining the value for the evaluation. From the integration of those things in this study, it is found that for PT X, Benefit has the biggest priority, followed by Opportunity, Risk, and Cost in Project Selection for PT X. It is also found that based on additive-BOCR, Project C gives the optimal value for PT X, followed by Project B, Project A, Project D, dan Project E.
Princing on Dual Channel Supply Chain by Considering Flash Sale Program on Online Channel (Case Study: A3 Printing)
Get PDFDual channel supply chain is a combination of offline channel and online channel are running simultaneously as a new structure. Through online channels, consumers can find the best product prices. This is used by companies to implementing promotional prices to attract the attention of online consumers, one of them is by the flash sale program. Promotion aims to stimulate demand for a company’s product but along with the increase in demand is not always accompanied by an increase in profit. So it is necessary to consider the selling price of the product during the promotion and how long the promotion will be applied. This research is focused on determining the selling price of products and duration of the promotion as well as the impact using the help of Malpe software and Microsoft Excel. This study concluded that the lower price and the longer duration applied during the flash sale leads on the higher demand but will result in a decrease in profits. So that promotional strategies using the flash sale program can be applied if the company's main goal is only to increase the number of sales
Catalytic Co-Cracking of Used Cooking Oil Methyl Ester and Polystyrene Waste for Gasoline-Rich Biofuel Over Mesoporous Al-MCM-41 Catalyst
Get PDFUsed cooking oil and packaging foam are typical waste materials that are abundantly available as household and fast food restaurant waste with high energy content, thus representing potential feedstock for conversion into an alternative energy source. In this study, catalytic co-cracking was examined at 300°C in atmospheric pressure to generate fuel products with gasoline-like properties from a mixture of used cooking oil biodiesel and polystyrene pyrolysis oil. Mixture of ceramic powder and Al-MCM-41 was used as catalyst in comparison to a pristine mesoporous aluminosilicate material. The product distribution of produced biofuel wes analyzed by gas chromatography – mass spectrometry. Experimental results exhibit that catalytic co-cracking process generated up to 64,6 – 67,2% yield of liquid hydrocarbon. The product distribution and the quality of the resulting biofuel were significantly affected by Si/Al ratio of the catalyst. Pristine Al-MCM-41 with lower Si/Al ratio was more favored for the enrichment of gasoline range fraction (C7–C12) which give 88,98% yield, while Al-MCM-41/ceramic with higher Si/Al ratio only give 32,84% yield of gasoline fraction. Moreover, lower oxygenate compound with better stability of biofuel was also obtained using pristine Al-MCM-41 catalyst. The produced biofuel blend by both catalysts indicated promising physical properties including higher calorific value (53,2 and 52,4 MJ/kg) and higher-octane number (RON 99,8 and 95,5) than commercial gasoline
3 Kg LPG Business Strategy Development Using BMC and BOS
Get PDFArief LPG is a new distributor that distributes 3 kg LPG gas in the Menanggal area, Surabaya. As a new distributor Arief LPG will face existing competitors, be able compete Arief LPG must have a business model that can be used as a reference for the business being undertaken. Tools that can be used to analyze business models are using Business Model Canvas (BMC) and Blue Ocean Strategy. Using Business Model Canvas and Blue Ocean Strategy can be used to create a new business model design. This study aims to map, evaluate and improve Arief LPG's business model. The method used in this study is by interviewing Arief LPG customers. Results obtained from the Business Model Canvas are adding types of LPG that are sold LPG 12 Kg in addition promotions that can be done using online media such as creating a personal Blog or Web, and other social media. While results of the Blue Ocean Strategy factors that need be reduced accuracy of delivery, factor that needs improved is increase the amount of 3 kg LPG distribution, and create factors that have never been sold, such Bright Gas, 12 kg LPG and making a training on gas handling
Mixed Integer Linear Programming as a Method for Evaluation of Location and Number of Buffer Warehouse in PT Petrokimia Gresik Distribution System (Case Study: West Java and Central Java)
Get PDFThe new policy issued by PT Pupuk Indonesia regarding the change of the responsible party for the procurement and the distribution of subsidized NPK fertilizers affected the subsidy allocation for PT Petrokimia Gresik, as the only company to conduct the procurement and distribution of the subsidized NPK fertilizer. It is now partially charged to the other holding members such as PT Kujang Cikampek, PT Pupuk Sriwidjaja, and PT Pupuk Kaltim. Also, all members of PT Pupuk Indonesia should face the reduction of subsidy allocation from Indonesia Government. PT Petrokimia Gresik also have to deal with Phonska V project plan in order to increase capacity of NPK fertilizer. Those policies are most significantlty impactful to the decrease of subsidy allocation in West Java. Besides, Central Java, a branch area of PT Petrokimia Gresik which has the biggest number of total capacity and fixed cost, should reevaluate the number and location of the buffer warehouse. This paper is aimed to explain the methodology using Mixed integer Linear Programming (MILP) in determining the optimal number and location of buffer warehouse in West Java and Central Java in response to the policies and the project plan. Firstly, the distribution system of NPK subsidized fertilizer are described. Next, previous researches about MILP and forecasting method applied in distribution system problem is explained. After that, related data and several conditions that are applied based on actual situation are shown. It can be deducted that MILP is an optimal method for the evaluation as it fits to the characteristic and condition of distribution system in PT Petrokimia Gresik
Evaluation of Hyper-Heuristic Method Using Simple Random-Step Counting Hill Climbing in the Examination Timetabling Problem
Get PDFExam Timetabling Problem (ETP) is a problem that occurs at the university. Solution to the ETP problem involves computational search methods to get results. In the process, if done manually it will require lot of time to achieve the optimal solution. ETP is basically allocating a schedule into room at particular time. Several previous researchers developed a hyper-heuristic method to obtain solutions that are expected to provide result that are close to optimal. In this study, ITC 2007 dataset will be used to find generic solutions that are near optimal. Simple Random (SR) was chosen as strategy to choose Low Level Heuristic (LLH) and Step Counting Hill Climbing (SCHC) was chosen as move-acceptance strategy for ETP. The results obtained show that one pair of algorithms proposed in this study is better than the literature while other algorithms also provide significant results
The Effect of Financial Ratio in Financial Distress with Firm Size as Moderated Variables (Empirical Study of Manufacturing Sector Companies Listed on The Indonesia Stock Exchange for The 2014-2018 Period)
Get PDFThis study aims to obtain empirical evidence and analyze the effect of financial ratios on financial distress with firm size as a moderating variable. The financial ratios include liquidity ratios that are proxied by Current Ratio, solvency ratios proxied by Debt Asset Ratio, profitability ratios proxied by Return on Assets and Firm Size proxied by the natural logarithm of Total Sales. The population in this study were manufacturing companies listed on the Indonesia Stock Exchange in 2014 - 2018. The total sample used in this study were 85 companies based on established criteria. Data analysis was performed by binary logistic regression and Moderated Regression Analysis. The results of the analysis of this study indicate that the Current Ratio, Debt Asset Ratio and Return on Assets have a significant negative effect on financial distress. The results of the Moderated Regression Analysis reveal that firm size has a significant moderation effect on the relationship between the three independent variables and financial distress in manufacturing companies
Determination of Optimum Point of Composition of Fuel Calories in Producing electrical Energy in Coal Fired Power Plant
Get PDFCoal-fired power plant (CFPP) is a type of power plant that is widely used for 35,000 MW electricity projects in Indonesia. CFPP must adjust to its operating strategies with the availability of abundant low-rank coal, and it will affect CFPP performance. This study aims to determine the optimum heating value of fuels, the trend of net plant heat rate (NPHR), the cost of electricity production (component C), and the optimum point of the CFPP operation. The data used is from CFPP operations. First, data is analyzed by descriptive statistics and formed into a regression model. The next step is to estimate the parameters of the population data. The regression model obtained was then carried out the goodness of fit test and residual analysis. Then, the variable’s values are changed to the Z-score and plotted in the regression model. The model interpretation is carried out and conclusions can be obtained to find out the optimum point. The conclusion of this study is the optimum point of generating electricity in CFPP can be achieved by using coal calorific values of 4,450 kCal/kg, NPHR of 2,683.6 kCal/kWh, and COE (component C) of Rp 436.5/kWh when using coal at a price of 732.2/kg and Net Power of 279 MW