Pub Date : 2019-07-26DOI: 10.12962/j20882033.v30i2.5000
Mochamad Puji Widodo, Yohannes Marudut Tua Silaen, Muhammad Faiq Ridho Ahada Kuswara, T. N. Rohmannudin
Organic inhibitors have been widely studying to be an alternative corrosion prevention because of its abundance and non-hazardous effect to the environment. One of organic inhibitors which is obtained from plant extract is banana (Musa Paradisica) peel, because it has gallocatechin which is a strong antioxidant. Otherwise, inhibition effectiveness from organic compound decreases during increasing of temperature. However, the addition of other substance like halide ion has provided multiple effect of corrosion inhibitor effectiveness. The addition of the halide ions can enhanced the inhibition efficiency of the organic inhibitors. This research highlights the effect of additional halide concentration to the inhibition effectiveness of Musa Paradisica (banana) peel on API 5 L steel in 3,5% NaCl at temperature 60C. This inhibition performance is investigated using weight loss measurement and electrochemical measurement. Result shows that the maximum inhibition efficiency was observed with the mixture of 500 ppm banana peel waaste extract and 100 ppm potassium iodide at 60C. Also, The blends behaved as mixed type inhibitor. The effectiveness was found to be in order of KI > KBr due to the larger ionic radius in iodide ion. Keywords Banana Peel Waste, Halide Concentration, Organic Inhibitor, Temperature 60C.
{"title":"Effect of Halide Concentration on the Effectiveness of Banana Peel Waste Inhibitor at 60C","authors":"Mochamad Puji Widodo, Yohannes Marudut Tua Silaen, Muhammad Faiq Ridho Ahada Kuswara, T. N. Rohmannudin","doi":"10.12962/j20882033.v30i2.5000","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.5000","url":null,"abstract":"Organic inhibitors have been widely studying to be an alternative corrosion prevention because of its abundance and non-hazardous effect to the environment. One of organic inhibitors which is obtained from plant extract is banana (Musa Paradisica) peel, because it has gallocatechin which is a strong antioxidant. Otherwise, inhibition effectiveness from organic compound decreases during increasing of temperature. However, the addition of other substance like halide ion has provided multiple effect of corrosion inhibitor effectiveness. The addition of the halide ions can enhanced the inhibition efficiency of the organic inhibitors. This research highlights the effect of additional halide concentration to the inhibition effectiveness of Musa Paradisica (banana) peel on API 5 L steel in 3,5% NaCl at temperature 60C. This inhibition performance is investigated using weight loss measurement and electrochemical measurement. Result shows that the maximum inhibition efficiency was observed with the mixture of 500 ppm banana peel waaste extract and 100 ppm potassium iodide at 60C. Also, The blends behaved as mixed type inhibitor. The effectiveness was found to be in order of KI > KBr due to the larger ionic radius in iodide ion. Keywords Banana Peel Waste, Halide Concentration, Organic Inhibitor, Temperature 60C.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"117 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79387243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-26DOI: 10.12962/j20882033.v30i2.5008
Akhmad Bakhrul Ilmi, D. Purwitasari, C. Fatichah
Scientific articles cited by other researchers have an impact on increasing author credibility. However, the citation process may be misused to unnaturally raise a bibliometric indicator value such as researcher’s h-index. Researchers may overly cites their own works, referred as self-citation, even though the topic of the references are not related to the current article. Further misconduct is excessive citations on the works of peoples related to the researcher which can be coercive or not, referred as conflict of interest (CoI). The proposed method uses a deep learning approach, Siamese Long ShortTerm Memory (LSTM), to recognize subject similarities between a scientific article and its references. Standard text similarity fails to do so because contextual relatedness of sentences in the articles need some learning process. Siamese-LSTM learns contextual relatedness of sentences in the article using two identical LSTM. Steps of the proposed method are (i) wordembedding to get weight values of terms but still considers their semantic relations, (ii) k-means clustering to generate training data for reducing time complexity in Siamese-LSTM learning of scientific articles, (iii) learns Siamese-LSTM weight from training data to identify contextual relatedness of sentences, (iv) calculate similarity of a scientific article with its references based on Siamese-LSTM. The empirical experiments are used to analyze similarity values and the possibility for conflict of interest in an article. KeywordsCitation, Conflict of Interest, Scientific Text, Deep Learning, Similarity, Text Processing.
{"title":"Siamese Long Short-Term Memory for Detecting Conflict of Interest on Scientific Papers","authors":"Akhmad Bakhrul Ilmi, D. Purwitasari, C. Fatichah","doi":"10.12962/j20882033.v30i2.5008","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.5008","url":null,"abstract":"Scientific articles cited by other researchers have an impact on increasing author credibility. However, the citation process may be misused to unnaturally raise a bibliometric indicator value such as researcher’s h-index. Researchers may overly cites their own works, referred as self-citation, even though the topic of the references are not related to the current article. Further misconduct is excessive citations on the works of peoples related to the researcher which can be coercive or not, referred as conflict of interest (CoI). The proposed method uses a deep learning approach, Siamese Long ShortTerm Memory (LSTM), to recognize subject similarities between a scientific article and its references. Standard text similarity fails to do so because contextual relatedness of sentences in the articles need some learning process. Siamese-LSTM learns contextual relatedness of sentences in the article using two identical LSTM. Steps of the proposed method are (i) wordembedding to get weight values of terms but still considers their semantic relations, (ii) k-means clustering to generate training data for reducing time complexity in Siamese-LSTM learning of scientific articles, (iii) learns Siamese-LSTM weight from training data to identify contextual relatedness of sentences, (iv) calculate similarity of a scientific article with its references based on Siamese-LSTM. The empirical experiments are used to analyze similarity values and the possibility for conflict of interest in an article. KeywordsCitation, Conflict of Interest, Scientific Text, Deep Learning, Similarity, Text Processing.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76958153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-26DOI: 10.12962/j20882033.v30i2.5006
Fathony Akbar Pratikno, Gazali Rachman, B. J. Santosa
Main earthquake with magnitude Mw 6.3, has been occurred in the West of Halmahera Island, Northern Molucca on June 7th, 2016. The activity of the Pacific plate, Eurasia plate and Indo-Australia plates trigger some earthquake around Halmahera. The purpose of the current study was to determine the Coulomb stress change of the main earthquake and predict the aftershocks’ location around it. For understanding an interaction of the faults, this study used Coulomb stress change model. Three component seismic waveform data recorded by TNTI station within 132 km, SANI station within 381.2 km, LUWI station within 478.3 km, and TOLI2 station within 617.6 km of the epicenter. This study used software ISOLA-GUI to obtain the parameters of the earthquake source. The parameters of the earthquake source were then used to determine fracture orientation, length, width and slip displacement. It was also used to calculate the Coulomb stress changes around the main shock, using software Coulomb 33. The result shows that the orientation of the earthquake fault has a dip angle of 48° to the horizontal plane and has a strike of 210° against the North. The fault length is 19.49 km, the fault width is 11.59 km and slip displacement is 49.43 cm. Based on plotting result, the main earthquake in Northern Molucca on June 7th, 2016 has positive Coulomb stress change that spread across the Northeast to the Southwest. This change is likely triggered three aftershocks with a range of Mw 4.7 to 6.2.
{"title":"Coulomb Stress Analysis of Halmahera Earthquake on June 7th 2016, Mw=6.3 and Its Correlation with Aftershocks","authors":"Fathony Akbar Pratikno, Gazali Rachman, B. J. Santosa","doi":"10.12962/j20882033.v30i2.5006","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.5006","url":null,"abstract":"Main earthquake with magnitude Mw 6.3, has been occurred in the West of Halmahera Island, Northern Molucca on June 7th, 2016. The activity of the Pacific plate, Eurasia plate and Indo-Australia plates trigger some earthquake around Halmahera. The purpose of the current study was to determine the Coulomb stress change of the main earthquake and predict the aftershocks’ location around it. For understanding an interaction of the faults, this study used Coulomb stress change model. Three component seismic waveform data recorded by TNTI station within 132 km, SANI station within 381.2 km, LUWI station within 478.3 km, and TOLI2 station within 617.6 km of the epicenter. This study used software ISOLA-GUI to obtain the parameters of the earthquake source. The parameters of the earthquake source were then used to determine fracture orientation, length, width and slip displacement. It was also used to calculate the Coulomb stress changes around the main shock, using software Coulomb 33. The result shows that the orientation of the earthquake fault has a dip angle of 48° to the horizontal plane and has a strike of 210° against the North. The fault length is 19.49 km, the fault width is 11.59 km and slip displacement is 49.43 cm. Based on plotting result, the main earthquake in Northern Molucca on June 7th, 2016 has positive Coulomb stress change that spread across the Northeast to the Southwest. This change is likely triggered three aftershocks with a range of Mw 4.7 to 6.2.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"229 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76299288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-26DOI: 10.12962/j20882033.v30i2.5010
Budi Siswanto, A. Sudiarno, P. Karningsih, H. Pariaman
Outsourcing has become the alternative scheme to gain improvement in several fields within a short time to many enterprises. One power generation in North Java implemented PM as planned maintenance strategy to maintain equipment by conducting insourcing and outsourcing scheme as PM execution. Both conditions must follow the same business process flow in PM execution process and there will occur some obstacles that interrupted PM process. The existing problem will be analyzed with House of Risk (HOR) method approach, supported by Integrated Manufacturing Open Systems Architecture (CIMOSA) process-based function modeling for identification method and Supply Chain Risk Identification System (SCRIS) risk structure identification used for mapping problem, root cause, and its relation. Analysis with HOR results in root causes that occurred within PM implementation process for both of them commonly has the same problem that is process business acknowledgment, but in outsourcing scheme not exist root cause on culture compliance and work task requirement, because they have a descriptive target to obtain service level agreement fulfillment. On both scheme still need an improving method to monitor and evaluate the PM work for better performance.
{"title":"Improvement of Preventive Maintenance Process Effectiveness in Insourcing and Outsourcing Scheme with House of Risk (HOR) Method Approach (A Case Study)","authors":"Budi Siswanto, A. Sudiarno, P. Karningsih, H. Pariaman","doi":"10.12962/j20882033.v30i2.5010","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.5010","url":null,"abstract":"Outsourcing has become the alternative scheme to gain improvement in several fields within a short time to many enterprises. One power generation in North Java implemented PM as planned maintenance strategy to maintain equipment by conducting insourcing and outsourcing scheme as PM execution. Both conditions must follow the same business process flow in PM execution process and there will occur some obstacles that interrupted PM process. The existing problem will be analyzed with House of Risk (HOR) method approach, supported by Integrated Manufacturing Open Systems Architecture (CIMOSA) process-based function modeling for identification method and Supply Chain Risk Identification System (SCRIS) risk structure identification used for mapping problem, root cause, and its relation. Analysis with HOR results in root causes that occurred within PM implementation process for both of them commonly has the same problem that is process business acknowledgment, but in outsourcing scheme not exist root cause on culture compliance and work task requirement, because they have a descriptive target to obtain service level agreement fulfillment. On both scheme still need an improving method to monitor and evaluate the PM work for better performance.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87129147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-26DOI: 10.12962/j20882033.v30i2.4994
Nastopo Darmawan, T. Yuwono
Muara Tawar Power Plant is located on the coast of Bekasi, West Java, Indonesia. Along with the economic development, there are plans to do reclamation the sea around Muara Tawar Power Plant and build around it as a port and industrial estate. This could potentially lead to an increase in sea water temperatures. This paper aims to determine the effect of increasing sea water temperature on the performance of steam turbine 1.4 in Muara Tawar Power Plant, which uses sea water as a condenser cooling medium. The intended performance is the output power of the steam turbine, the condenser pressure and the system efficiency. Steam turbine 1.4 has 225 MW installed output power, supplied from 3 HRSG (Heat Recovery Steam Generator).Analysis of the effect of sea water temperature rise on steam turbine performance is carried out by using the cycle-tempo software. The main equipment of steam turbine is modeled in cycle-tempo, then model is validated by comparing with design data. Varies sea water temperature then is inputted on model in order to obtain the output power of steam turbine, condenser pressure and system efficiency. The results show that for every 1˚C increase in condenser cooling water temperature extracted from seawater near the plant, the output power of the plant decreased by about 0.171%, the condenser pressure increased by about 5.146%, and the system efficiency decreased by about 0.168%.
Muara Tawar发电厂位于印度尼西亚西爪哇勿加西海岸。随着经济的发展，有计划在Muara Tawar发电厂周围进行填海，并在其周围建造港口和工业区。这可能会导致海水温度升高。本文旨在确定提高海水温度对Muara Tawar电厂以海水作为冷凝器冷却介质的1.4汽轮机性能的影响。预期的性能是汽轮机的输出功率、冷凝器压力和系统效率。汽轮机1.4具有225兆瓦的安装输出功率，由3个HRSG(热回收蒸汽发生器)提供。利用循环速度软件分析了海水温度升高对汽轮机性能的影响。对汽轮机主要设备进行了循环速度建模，并与设计数据进行了对比验证。然后在模型中输入变化的海水温度，得到汽轮机的输出功率、冷凝器压力和系统效率。结果表明，从电厂附近海水中提取的冷凝器冷却水温度每升高1℃，电厂输出功率降低约0.171%，冷凝器压力升高约5.146%，系统效率降低约0.168%。
{"title":"Effect of Increasing Sea Water Temperature on Performance of Steam Turbine of Muara Tawar Power Plant","authors":"Nastopo Darmawan, T. Yuwono","doi":"10.12962/j20882033.v30i2.4994","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.4994","url":null,"abstract":"Muara Tawar Power Plant is located on the coast of Bekasi, West Java, Indonesia. Along with the economic development, there are plans to do reclamation the sea around Muara Tawar Power Plant and build around it as a port and industrial estate. This could potentially lead to an increase in sea water temperatures. This paper aims to determine the effect of increasing sea water temperature on the performance of steam turbine 1.4 in Muara Tawar Power Plant, which uses sea water as a condenser cooling medium. The intended performance is the output power of the steam turbine, the condenser pressure and the system efficiency. Steam turbine 1.4 has 225 MW installed output power, supplied from 3 HRSG (Heat Recovery Steam Generator).Analysis of the effect of sea water temperature rise on steam turbine performance is carried out by using the cycle-tempo software. The main equipment of steam turbine is modeled in cycle-tempo, then model is validated by comparing with design data. Varies sea water temperature then is inputted on model in order to obtain the output power of steam turbine, condenser pressure and system efficiency. The results show that for every 1˚C increase in condenser cooling water temperature extracted from seawater near the plant, the output power of the plant decreased by about 0.171%, the condenser pressure increased by about 5.146%, and the system efficiency decreased by about 0.168%.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82847466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-05-03DOI: 10.12962/J20882033.V29I3.3690
Akhmad Taufik Aditama, J. J. Ekaputri, E. Ahyudanari
The previous study showed that asphalt concrete using filler geopolymer generate a higher value of stability. On the other hand, the value of flow and the porosity of the asphalt concrete were out of the specification range. This study examines the aggregate gradation analysis to improve the characteristics of mixed asphalt concrete geopolymer. The gradation of aggregate is variated into three following the available specification. The range of specification is then separated into three, those are aggregate gradation upper specifications, middle specification, and lower specification. Filler comes from geopolymer paste, composed of fly ash which is mixed with an activator. Activator is an 8 molar concentration of NaOH solution and Na₂SiO₃. The weight ratio of Na₂SiO₃ over the weight of NaOH solution was 1.5. Geopolymer paste waited until reached the age of 28 days, then pounded up to meet the requirement size of the sieve No. 200. The test of mixture characteristics was conducted to see the comparison of performance from different gradations. The test results showed that middle gradation generating characteristics of the mixture which is higher than upper gradation and lower gradation.
{"title":"Analysis of Aggregate Gradation to Improve The Characteristics of Geopolymer Based Asphalt Concrete","authors":"Akhmad Taufik Aditama, J. J. Ekaputri, E. Ahyudanari","doi":"10.12962/J20882033.V29I3.3690","DOIUrl":"https://doi.org/10.12962/J20882033.V29I3.3690","url":null,"abstract":"The previous study showed that asphalt concrete using filler geopolymer generate a higher value of stability. On the other hand, the value of flow and the porosity of the asphalt concrete were out of the specification range. This study examines the aggregate gradation analysis to improve the characteristics of mixed asphalt concrete geopolymer. The gradation of aggregate is variated into three following the available specification. The range of specification is then separated into three, those are aggregate gradation upper specifications, middle specification, and lower specification. Filler comes from geopolymer paste, composed of fly ash which is mixed with an activator. Activator is an 8 molar concentration of NaOH solution and Na₂SiO₃. The weight ratio of Na₂SiO₃ over the weight of NaOH solution was 1.5. Geopolymer paste waited until reached the age of 28 days, then pounded up to meet the requirement size of the sieve No. 200. The test of mixture characteristics was conducted to see the comparison of performance from different gradations. The test results showed that middle gradation generating characteristics of the mixture which is higher than upper gradation and lower gradation.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90914021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-08DOI: 10.12962/J20882033.V30I1.4993
E. Ariyanto, W. A. Widodo
This study deals with flow and heat transfer characteristic in a Heat Exchanger if its tube modules completely or partially dismantled. The heat exchanger is a Steam Coil Air Heater (SCAH) Installed in Gresik unit 1 Steam Turbine Power Plant. Nowadays the power plant operate mostly utilized natural gas as a fuel. When it utilized natural gas SCAH are not give benefit and only give flow resistance for combustion air flow. This study use numerical simulation model with commercial Computational Fluid Dynamic (CFD) software. The simulation on 3D model with steady state flow condition. The model use energy model, Heat Exchanger Model, realizable k-Epsilon for turbulence viscous model and SCAH model as Porous Medium (PM). Modelling SCAH as a PM will avoid time consuming mesh generation and simulations with high CPU usage. Fives scenarios of tube module dismantling simulated in 100% load. This study result both quantitative and qualitative data coresspond with flow and heat transfer characteristic. The model with original scenarios give good result in terms of pressure and outlet temperature with commisioning data. The contour data results show there are several secondary flow due to enlargement of flow area. Numerical results of variation S1,S2,S3,S4 are indicated decreasing total pressure drop about 32.27%, 51.29%, 47.04%, 65.25% respectively. And temperature rise for each schenario will decrease to 29.29% (S1), 46.51% (S2) , 47.92% (S3), 68.28% (S4) respectively,except for S5 have no pressure drop and temperature rise since all module are dismantled.
{"title":"Steam Coil Air Heater (SCAH) Modelling as Porous Medium to Analyze Flow Characteristic and Reduce Self Energy Usage in Gresik Unit 1 Steam Power Plant","authors":"E. Ariyanto, W. A. Widodo","doi":"10.12962/J20882033.V30I1.4993","DOIUrl":"https://doi.org/10.12962/J20882033.V30I1.4993","url":null,"abstract":"This study deals with flow and heat transfer characteristic in a Heat Exchanger if its tube modules completely or partially dismantled. The heat exchanger is a Steam Coil Air Heater (SCAH) Installed in Gresik unit 1 Steam Turbine Power Plant. Nowadays the power plant operate mostly utilized natural gas as a fuel. When it utilized natural gas SCAH are not give benefit and only give flow resistance for combustion air flow. This study use numerical simulation model with commercial Computational Fluid Dynamic (CFD) software. The simulation on 3D model with steady state flow condition. The model use energy model, Heat Exchanger Model, realizable k-Epsilon for turbulence viscous model and SCAH model as Porous Medium (PM). Modelling SCAH as a PM will avoid time consuming mesh generation and simulations with high CPU usage. Fives scenarios of tube module dismantling simulated in 100% load. This study result both quantitative and qualitative data coresspond with flow and heat transfer characteristic. The model with original scenarios give good result in terms of pressure and outlet temperature with commisioning data. The contour data results show there are several secondary flow due to enlargement of flow area. Numerical results of variation S1,S2,S3,S4 are indicated decreasing total pressure drop about 32.27%, 51.29%, 47.04%, 65.25% respectively. And temperature rise for each schenario will decrease to 29.29% (S1), 46.51% (S2) , 47.92% (S3), 68.28% (S4) respectively,except for S5 have no pressure drop and temperature rise since all module are dismantled.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80373569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-08DOI: 10.12962/J20882033.V30I1.5009
Norman Mahdar Sabana, E. Djatmiko, R. Prastianto
This paper studies fatigue life of mooring lines applied on turret-moored Floating LNG (Liquefied Natural Gas). Several case studies were designed to investigate the influence of mooring pretension and water depth on the fatigue life of mooring lines. Floating LNG with permanent external turret mooring system consists of 12 catenary lines arranged in 3 groups with four lines each. Time domain simulation applied to calculated coupled dynamic response and mooring tension. Fatigue life is assessed using the rain-flow counting method, T-N curves, and Palmgren-Miner rule. Analysis results for mooring pretension case show that case study 2 with the lowest pretension (14%MBL) yields shortest mooring fatigue life of 1814.20 years compared to case study 1 (18%MBL) and 3 (22%MBL) with 2034.61 years and 2983.33 years respectively. Despite having the lowest dynamic line tension, case study 2 has a larger tension range that results in the increased of fatigue damage. The increase in water depth will increase the mooring line length and its weight, so it results in an increase in fatigue damage. It is reflected in case study 5 (903m water depth), which has shortest mooring fatigue life of 1842.65 years compare to case study 1 (602m water depth) and 4 (301m water depth) with 2983.33 years and 3363.62 years
{"title":"Fatigue Life of Mooring Lines on External Turret Floating LNG for Different Pretension and Water Depth","authors":"Norman Mahdar Sabana, E. Djatmiko, R. Prastianto","doi":"10.12962/J20882033.V30I1.5009","DOIUrl":"https://doi.org/10.12962/J20882033.V30I1.5009","url":null,"abstract":" This paper studies fatigue life of mooring lines applied on turret-moored Floating LNG (Liquefied Natural Gas). Several case studies were designed to investigate the influence of mooring pretension and water depth on the fatigue life of mooring lines. Floating LNG with permanent external turret mooring system consists of 12 catenary lines arranged in 3 groups with four lines each. Time domain simulation applied to calculated coupled dynamic response and mooring tension. Fatigue life is assessed using the rain-flow counting method, T-N curves, and Palmgren-Miner rule. Analysis results for mooring pretension case show that case study 2 with the lowest pretension (14%MBL) yields shortest mooring fatigue life of 1814.20 years compared to case study 1 (18%MBL) and 3 (22%MBL) with 2034.61 years and 2983.33 years respectively. Despite having the lowest dynamic line tension, case study 2 has a larger tension range that results in the increased of fatigue damage. The increase in water depth will increase the mooring line length and its weight, so it results in an increase in fatigue damage. It is reflected in case study 5 (903m water depth), which has shortest mooring fatigue life of 1842.65 years compare to case study 1 (602m water depth) and 4 (301m water depth) with 2983.33 years and 3363.62 years","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78248882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-08DOI: 10.12962/j20882033.v30i2.4999
A. Wirahadi, H. Mirmanto
Circulating Fluidized Bed (CFB) Boiler has advantages when uses low rank coal compared to Pulverized Boiler. It will be less operational cost but it has greater risk in degradation because of sands material inside the process. Air combustion between primary air and secondary air is one importance parameter that influence fluidization of CFB. Numerical simulation of commercial CFD was used with Eulerian multiphase model implemented to analyzed sand volume of fraction, air and sand velocity including distribution of pressure around furnace. It was used 55%-45% air combustion ratio of primary and secondary air as reference when boiler operated at 63% and 100% based on operation performance of CFB and then it was simulated with additional variation of air combustion ratio with 50%-50%. Simulation of 110% load was added using all of variation of air combustion. The simulation showed that fluidization with air combustion ratio 50%-50% and 55%-45% executed well when operated at 63%. Meanwhile, fluidization 100% and 110% with all those air combustion ratios would cause a great number of sands entered inlet cyclone and higher sands and air velocities.
{"title":"3-D Numerical Study of CFB 110 MW: Fluidization in Furnace and Cyclone with Loads And Air Combustion Variation","authors":"A. Wirahadi, H. Mirmanto","doi":"10.12962/j20882033.v30i2.4999","DOIUrl":"https://doi.org/10.12962/j20882033.v30i2.4999","url":null,"abstract":"Circulating Fluidized Bed (CFB) Boiler has advantages when uses low rank coal compared to Pulverized Boiler. It will be less operational cost but it has greater risk in degradation because of sands material inside the process. Air combustion between primary air and secondary air is one importance parameter that influence fluidization of CFB. Numerical simulation of commercial CFD was used with Eulerian multiphase model implemented to analyzed sand volume of fraction, air and sand velocity including distribution of pressure around furnace. It was used 55%-45% air combustion ratio of primary and secondary air as reference when boiler operated at 63% and 100% based on operation performance of CFB and then it was simulated with additional variation of air combustion ratio with 50%-50%. Simulation of 110% load was added using all of variation of air combustion. The simulation showed that fluidization with air combustion ratio 50%-50% and 55%-45% executed well when operated at 63%. Meanwhile, fluidization 100% and 110% with all those air combustion ratios would cause a great number of sands entered inlet cyclone and higher sands and air velocities.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"61 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87736039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-08DOI: 10.12962/J20882033.V30I1.4998
L. Thenu, N. Karnaningroem
AbstractRemu River has been a water resource for residents in Sorong City. Development in this city leads to water quality degradation of Remu River. Existing (2016) and prediction condition of Remu River in the next two years were defined by the behavior of BOD, COD, Fe, and DO that proceed using a dynamic program, STELLA 9.1.3. Study area involved six sampling points. Simulation results showed that BOD, COD, and Fe concentrations tend to increase in the next two years, even BOD and COD concentrations at several sampling points were higher than water quality standard, according to Government Regulation No. 82/2001. Meanwhile, DO concentration was below the limit in 4 to 6 sampling points. The pollution control strategy was conducted by setting up three scenarios: (1) procurement of Waste Water Treatment Plant (WWTP), (2) river sediment dredging, and (3) combination of both scenario. Combination of sediment dredging and procurement of WWTP scenario estimated to reduce BOD concentration to 89.82%, COD concentration to 87.02%, and increase DO concentration to 19.07%. So, the 3 scenario was determined as the best strategy to improve Remu River water quality, although Fe concentration cannot be controlled as it comes from nature.
{"title":"Study of Remu River Water Quality Using Dynamic Program","authors":"L. Thenu, N. Karnaningroem","doi":"10.12962/J20882033.V30I1.4998","DOIUrl":"https://doi.org/10.12962/J20882033.V30I1.4998","url":null,"abstract":"AbstractRemu River has been a water resource for residents in Sorong City. Development in this city leads to water quality degradation of Remu River. Existing (2016) and prediction condition of Remu River in the next two years were defined by the behavior of BOD, COD, Fe, and DO that proceed using a dynamic program, STELLA 9.1.3. Study area involved six sampling points. Simulation results showed that BOD, COD, and Fe concentrations tend to increase in the next two years, even BOD and COD concentrations at several sampling points were higher than water quality standard, according to Government Regulation No. 82/2001. Meanwhile, DO concentration was below the limit in 4 to 6 sampling points. The pollution control strategy was conducted by setting up three scenarios: (1) procurement of Waste Water Treatment Plant (WWTP), (2) river sediment dredging, and (3) combination of both scenario. Combination of sediment dredging and procurement of WWTP scenario estimated to reduce BOD concentration to 89.82%, COD concentration to 87.02%, and increase DO concentration to 19.07%. So, the 3 scenario was determined as the best strategy to improve Remu River water quality, although Fe concentration cannot be controlled as it comes from nature.","PeriodicalId":14549,"journal":{"name":"IPTEK: The Journal for Technology and Science","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82817516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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