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The present study investigates the structural integrity of a wind turbine tower structure under axial compression, described as a tapered tubular structure. Initially, the NREL model of the 5 MW-net wind turbine model was adapted and then scaled down to simplify the numerical analysis and for the convenience of future experimental study. The analysis was conducted using the Finite Element Modelling software Abaqus. To ensure the validity of the FEM modelling, the benchmarking study is conducted by referring to previously published work. The case configuration was developed by varying the material properties of the tower (high, medium, and low carbon steels) and the material properties of the tower due to the effect of the site temperature. The results obtained show that high carbon steel has the best properties for use in wind turbine structures. At -80 °C, this is the temperature condition where AH32 material has the best properties.

PT. Indonesia Hijau carries out innovation in the form of a processing business made from fermented cocoa beans. Processing cocoa beans into several types of chocolate products creates added value and also sells buy order chocolate products. This research aims to analyze production performance and marketing mapping of processed chocolate products. The method used in this research is quantitative descriptive analysis. The results of the production performance of PT. Green Indonesia from the productivity aspect is categorized as good (>21,55 kg/HOK) and the capacity aspect is also categorized as good (>0.7). From the aspect of raw material and product quality, PT Indonesia Hijau has SNI, P-IRT, Halal and BPOM status. Apart from that, the flexibility aspect is considered to be good because it meets 3 dimensional measurements and also has a relatively good process speed aspect. However, this research suggests that the use of e-commerce in marketing can be optimized. Apart from that, you need to think about product delivery, which currently still takes a long time (because you have to transit first) in several cities, before arriving at the final destination city by means of the local government making a port of delivery of goods.

Acid mine drainage (AMD) is one of the common environmental problems in the coal mining industry that was formed by the oxidation of sulfide minerals in the overburden or waste rock. The prediction of acid generation through AMD is important to do in overburden management and planning the post-mining land use. One of the methods used to predict AMD is a lab-scale kinetic test to determine the rate of acid formation over time using representative samples in the field. However, this test requires a long-time procedure and large amount of chemical reagents lead to inefficient cost. On the other hand, there is potential for machine learning to learn the pattern behind the lab-scale kinetic test data. This study describes an approach to use artificial neural network (ANN) modeling to predict the result from lab-scale kinetic tests. Various ANN model is used based on 83 weeks experiments of lab-scale kinetic tests with 100% potential acid-forming rock. The model approaches the monitoring of pH, ORP, conductivity, TDS, sulfate, and heavy metals (Fe and Mn). The overall Nash-Sutcliffe Efficiency (NSE) obtained in this study was 0.99 on training and validation data, indicating a strong correlation and accurate prediction compared to the actual lab-scale kinetic tests data. This show the ANN ability to learn patterns, trends, and seasonality from past data for accurate forecasting, thereby highlighting its significant contribution to solving AMD problems. This research is also expected to establish the foundation for a new approach to predict AMD, with time efficient, accurate, and cost-effectiveness in future applications.

Reduced forest or deforestation is widespread in East Aceh Regency for plantation, agriculture and settlement purposes. Forests in Sumatra, including in East Aceh Regency are Sumatran Elephant habitat (Elephas maximus sumatranus). However, encroachment resulted in this fauna threatened sustainability, whereas Sumatran elephants are endangered species protected by law both since Dutch colonialism, post-independence, and international regulations, and Sumatran elephants have an vital ecosystem role but are seen as a nuisance to the local economy in East Aceh Regency, so it is not electrocuted, killed and abused. This paper reviews the deforestation of the Sumatran Elephant in East Aceh Regency. The results of the study show that elephant roaming areas intersect with deforestation that occurred in East Aceh Regency. As an alternative local economy, there is still the potential of ecotourism with the mascot of the Sumatran elephant. Thus the Sumatran elephant is still able to be sustainable, and the forest as habitat is maintained.