• Energy Research
• 13. Climate action close
• 15. Life on land close
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• University of North Sumatra close

In this work, a compression ignition (CI) engine is tested in dual-fuel mode (Diesel-Raw biogas). The objective is to examine the performance and emission characteristics of the engine when some of the diesel oil is replaced by biogas. The specifications of the CI engine are air cooled single horizontal cylinder, four strokes, and maximum output power of 4.86 kW. It is coupled with a synchronous three phase generator. The load, engine revolution, and biogas flow rate are varied from 600 W to 1500 W, 1000 rpm to 1500 rpm, 0 to 6 L/minute, respectively. The electric power, specific fuel consumption, thermal efficiency, gas emission, and diesel replacement ratio are analyzed. The results show that there is no significant difference of the power resulted by CI run on dual-fuel mode in comparison with pure diesel mode. However, the specific fuel consumption and efficiency decrease significantly as biogas flow rate increases. On the other hand, emission of the engine on dual-fuel mode is better. The main conclusion can be drawn is that CI engine without significant modification can be operated perfectly in dual-fuel mode and diesel oil consumption can be decreased up to 87.5%.

In this work, a compression ignition (CI) engine is tested in dual-fuel mode (Diesel-Raw biogas). The objective is to examine the performance and emission characteristics of the engine when some of the diesel oil is replaced by biogas. The specifications of the CI engine are air cooled single horizontal cylinder, four strokes, and maximum output power of 4.86 kW. It is coupled with a synchronous three phase generator. The load, engine revolution, and biogas flow rate are varied from 600 W to 1500 W, 1000 rpm to 1500 rpm, 0 to 6 L/minute, respectively. The electric power, specific fuel consumption, thermal efficiency, gas emission, and diesel replacement ratio are analyzed. The results show that there is no significant difference of the power resulted by CI run on dual-fuel mode in comparison with pure diesel mode. However, the specific fuel consumption and efficiency decrease significantly as biogas flow rate increases. On the other hand, emission of the engine on dual-fuel mode is better. The main conclusion can be drawn is that CI engine without significant modification can be operated perfectly in dual-fuel mode and diesel oil consumption can be decreased up to 87.5%.

Total dissolved solid prediction is an important factor which can support the early warning of water pollution, especially in the areas exposed to a mixture of pollutants. In this study, a new fuzzy-based intelligent system was developed, due to the uncertainty of the TDS time series data, by integrating optimization algorithms. Monthly-timescale water quality parameters data from nearly four decades (1974–2016), recorded over two gaging stations in coastal Iran, were used for the analysis. For model implementation, the current research aims to model the TDS parameter in a river system by using relevant biochemical parameters such as Ca, Mg, Na, and HCO3. To produce more compact networks along with the model’s generalization, a hybrid model which integrates a fuzzy-based intelligent system with the grasshopper optimization algorithm, NF-GMDH-GOA, is proposed for the prediction of the monthly TDS, and the prediction results are compared with five standalone and hybrid machine learning techniques. Results show that the proposed integrated NF-GMDH-GOA was able to provide an algorithmically informed simulation (NSE = 0.970 for Rig-Cheshmeh and NSE = 0.94 Soleyman Tangeh) of the dynamics of TDS records comparable to the artificial neural network, extreme learning machine, adaptive neuro fuzzy inference system, GMDH, and NF-GMDH-PSO models. According to the results of sensitivity analysis, Sodium in natural bodies of water with maximum value of error (RMSE = 56.4) had the highest influence on the TDS prediction for both stations, and Mg with RMSE = 43.251 stood second. The results of the Wilcoxon signed rank tests also indicated that the model’s prediction means were different, as the p value calculated for the models was less than the standard significance level (α=0.05).

Total dissolved solid prediction is an important factor which can support the early warning of water pollution, especially in the areas exposed to a mixture of pollutants. In this study, a new fuzzy-based intelligent system was developed, due to the uncertainty of the TDS time series data, by integrating optimization algorithms. Monthly-timescale water quality parameters data from nearly four decades (1974–2016), recorded over two gaging stations in coastal Iran, were used for the analysis. For model implementation, the current research aims to model the TDS parameter in a river system by using relevant biochemical parameters such as Ca, Mg, Na, and HCO3. To produce more compact networks along with the model’s generalization, a hybrid model which integrates a fuzzy-based intelligent system with the grasshopper optimization algorithm, NF-GMDH-GOA, is proposed for the prediction of the monthly TDS, and the prediction results are compared with five standalone and hybrid machine learning techniques. Results show that the proposed integrated NF-GMDH-GOA was able to provide an algorithmically informed simulation (NSE = 0.970 for Rig-Cheshmeh and NSE = 0.94 Soleyman Tangeh) of the dynamics of TDS records comparable to the artificial neural network, extreme learning machine, adaptive neuro fuzzy inference system, GMDH, and NF-GMDH-PSO models. According to the results of sensitivity analysis, Sodium in natural bodies of water with maximum value of error (RMSE = 56.4) had the highest influence on the TDS prediction for both stations, and Mg with RMSE = 43.251 stood second. The results of the Wilcoxon signed rank tests also indicated that the model’s prediction means were different, as the p value calculated for the models was less than the standard significance level (α=0.05).

Abstract This work studied experimentally the performance and exhaust gas emission of a diesel engine coupled with a catalytic converter run on dual-fuel mode using refined biogas resulted from agricultural waste. The content of methane on the biogas is 70%. The experiments were carried out at constant load 1500 kW. The engine rotation varies from 1000 rpm to 1500 rpm. The biogas flow rate varies from 0 to 6 L/min. The output power of the engine operated on dual-fuel mode is better than the engine operated with pure diesel. The brake thermal efficiency of the diesel engine with flow rate of 2 L/min and 4 L/min is better than diesel only. The specific fuel consumption of the diesel engine operated on dual-fuel mode is higher than pure diesel mode. The opacity number of the engine operated on dual-fuel mode is better than pure diesel mode. However, the CO number and HC number of the engine operated on dual-fuel mode are higher than pure diesel mode. The diesel replacement ratio is within the range 15.6% % to 74.8%. It is recommended to run the present diesel engine in dual fuel mode with biogas flow rate 2 L/min - 4 L/min.

Abstract This work studied experimentally the performance and exhaust gas emission of a diesel engine coupled with a catalytic converter run on dual-fuel mode using refined biogas resulted from agricultural waste. The content of methane on the biogas is 70%. The experiments were carried out at constant load 1500 kW. The engine rotation varies from 1000 rpm to 1500 rpm. The biogas flow rate varies from 0 to 6 L/min. The output power of the engine operated on dual-fuel mode is better than the engine operated with pure diesel. The brake thermal efficiency of the diesel engine with flow rate of 2 L/min and 4 L/min is better than diesel only. The specific fuel consumption of the diesel engine operated on dual-fuel mode is higher than pure diesel mode. The opacity number of the engine operated on dual-fuel mode is better than pure diesel mode. However, the CO number and HC number of the engine operated on dual-fuel mode are higher than pure diesel mode. The diesel replacement ratio is within the range 15.6% % to 74.8%. It is recommended to run the present diesel engine in dual fuel mode with biogas flow rate 2 L/min - 4 L/min.

 Indonesia is a maritime country that has a sea area of ​​5.8 million km², with enormous potential for marine products. The fisheries sector is one of the things that supports the third largest Indonesian economy with a GDP (Gross Domestic Product) of Rp 1.900 billion. There are many fishery ports in Indonesia commonly referred to as Fish Landing Base. In North Sumatra itself, there are 23 Fish Landing Base, and one of the areas that include it in the RTRW (Regional Spatial Plan) is Serdang Bedagai Regency, especially in Cermin Beach sub-district. However, the fact that the fisheries sector is not the main attraction of the Pantai Cermin area indicates no fishery center. This Fish Landing Base uses problem-solving to solve existing problems, starting from the formulation stage, location surveys, data collection, literature studies, and comparative studies. To respond these issues, ecological architecture becomes the answer to the problem of design conditions, such as responding according to local conditions both from society and nature. Fish Landing Base in Pantai Cermin expect to respond to users comfortably, creates interaction between users and the environment, and can also form a public space so that it can encourage economic generators based on sources of life in coastal areas, and so become one of the new tourist destinations to enjoy the marine products of Indonesia, especially in Serdang Bedagai, North Sumatera.

 Indonesia is a maritime country that has a sea area of ​​5.8 million km², with enormous potential for marine products. The fisheries sector is one of the things that supports the third largest Indonesian economy with a GDP (Gross Domestic Product) of Rp 1.900 billion. There are many fishery ports in Indonesia commonly referred to as Fish Landing Base. In North Sumatra itself, there are 23 Fish Landing Base, and one of the areas that include it in the RTRW (Regional Spatial Plan) is Serdang Bedagai Regency, especially in Cermin Beach sub-district. However, the fact that the fisheries sector is not the main attraction of the Pantai Cermin area indicates no fishery center. This Fish Landing Base uses problem-solving to solve existing problems, starting from the formulation stage, location surveys, data collection, literature studies, and comparative studies. To respond these issues, ecological architecture becomes the answer to the problem of design conditions, such as responding according to local conditions both from society and nature. Fish Landing Base in Pantai Cermin expect to respond to users comfortably, creates interaction between users and the environment, and can also form a public space so that it can encourage economic generators based on sources of life in coastal areas, and so become one of the new tourist destinations to enjoy the marine products of Indonesia, especially in Serdang Bedagai, North Sumatera.

Food Estate is a government program as a solution to meeting food demand. However, in order to meet food needs, environmental impacts must be considered. The study objective was to investigate the impacts of shallot production in Food Estate Hutajulu, Indonesia. The study was conducted with the first stage determining the functional unit, namely an area of 0.2 hectares with a gate-to-gate scope. The second is the inventory data analysis by grouping the categories of nursery, tillage, maintenance, harvesting, and transportation. The third is life cycle impact assessment (LCIA) according to the ISO 14044 standard. Every data obtained from each process was processed using the software OpenLCA 1.11.0; the following is the workflow and use of the software. Processes were made based on the five categories of data (soil processing, planting, maintenance, harvesting and transportation), which had been determined to be connected to flow. The product system was adjusted according to the data in each process and then calculated, and the results of calculation data and graph models appear from each processed data category. Fourth is the interpretation that considers the highest environmental impact, namely acidification in the transportation process of 1.8974 kg SO2 eq, global warming potential in the transportation process of 415.3188 kg CO2 eq, eutrophication in the transportation process of 0.4364 kg PO4 eq, and human toxicity in the maintenance process of 1,409.07377 kg 1,4-DB eq. To minimize the impact on subsequent production, reducing diesel fuel, chemical pesticides and chemical fertilizers are recommended.