Engineering Headway Vol. 39

Abstract: The accumulation of plastic waste and rice husk waste is a serious problem for the environment, even though both types of waste have good characteristics and have the potential to be used as new materials. Thermal pretreatment with the torrefaction method is one of the options to overcome the problem of accumulation of both types of waste. The purpose of this research is to make functional materials from LDPE plastic as a matrix and rice husk waste as a filler through the torrefaction method. The rice husk was dried in an oven at 70°C for 1 hour, then blended until smooth and filtered using a mesh 60 sieve. Rice husk was mixed with LDPE plastic in the mold before the torrefaction process with variations of holding time of 30 minutes, 60 minutes, and 90 minutes. After the torrefaction process, the material that had been formed was then tested to determine its characteristics. The highest tensile strength was obtained at a holding time of 30 minutes with a tensile strength of 8.06 N/mm². The highest impact strength was obtained at a holding time of 30 minutes with an impact strength of 13.61 J/mm². The lowest water absorption was obtained at a holding time of 60 minutes with a water absorption of 1.06%. The use of plastic waste and rice husks in producing new materials shows good characteristics as functional materials, while also having the potential to reduce the accumulation of waste which is a global threat.

Abstract: One significant environmental issue is noise pollution, which can have adverse effects on human health and behavior. One potential solution is the use of sound insulation materials to reduce sound transmission. This study aims to develop sound insulation materials from agro-industrial waste, specifically bagasse, which is an abundant raw material both globally and in Indonesia. The experimental design employed a 3² full factorial design, with perforation diameter and perforation depth as factors, each at three levels (–1, 0, and +1). Sound Transmission Loss (STL) testing was conducted using a homemade apparatus developed in accordance with the ASTM E2611-09 standard. The experimental results were analyzed using a two-way ANOVA. The ANOVA results indicate that perforation diameter, perforation depth, and their interaction significantly influence STL values. Improved sound insulation performance was achieved by reducing the number of partial perforations, as confirmed through experimental verification. The optimal sample was identified as S1A, with a perforation diameter of 1 mm and a perforation depth of 25%. The results demonstrate that bagasse has strong potential as a sound insulation material, with the developed sample achieving an average sound insulation of 12 dB at mid-range frequencies.

Abstract: This study evaluates the damping capacity of mortar modified with crumb rubber aggregate under two conditions: normal and incinerated. Crumb rubber is utilized as a potential recycled material to enhance the mechanical properties of mortar, particularly in applications requiring damping capabilities. In this study, conventional mortar is mixed with crumb rubber at a specified fraction, then tested under normal conditions and after under going an incineration. The damping tests were conducted using standard vibration damping methods to assess the performance of each type of mortar. The results indicate that mortar with incinerated crumb rubber exhibits higher damping capacity compare to mortar with normal crumb rubber. Further analysis reveals that the incineration process increases the surface roughness of the crumb rubber aggregate, contributing to improved interaction between the mortar matrix and the aggregate. Additionally, the conclution of incinerated crumb rubber not only enhances damping capacity but also shows potential improving durability and resistance to dynamic loads. This research provides new insights into use of incinerated crumb rubber as an additive in mortar, offering sustainable and innovative solutions in the construction field. These findings are expected to promote the adoption of recycled materials in the construction industry, supporting greener and more efficient construction practices.

Abstract: This study investigates the structural feasibility of aluminum foam sandwich (SAF) materials for the N219 amphibious aircraft floats using finite element method (FEM) simulations. Focused on enhancing crashworthiness, the analysis evaluates energy absorption under low-speed impacts (62–76 knots) and partial vertical loads (3.7–4.8 tons), comparing AFS with varying core thicknesses (3–7 mm) against conventional Aluminium 6061-T6. Results demonstrate that the 7 mm AFS core significantly reduces von Mises stress (134.5 MPa at 4.8 tons, 62 knots) compared to Al 6061-T6 (210.7 MPa under identical conditions), while improving specific energy absorption (SEA) and crash force efficiency (CFE). Validated against experimental data with a 5.71% error margin, the simulations confirm compliance with FAA and ICAO safety standards. The study highlights AFS’s potential to enhance lightweight design without compromising structural integrity, offering a novel solution for Indonesia’s amphibious aircraft development. This innovation addresses critical challenges in buoyancy, hydrodynamic stability, and crashworthiness for archipelagic transportation.

Abstract: This study aims to evaluate the effectiveness of using Vibration Damper Foam (VDF) as a vibration damping component in electric car batteries. The need for vehicles that are lightweight but resistant to vibrations due to poor road conditions is increasingly important, given the potential damage to battery cells that can cause failures, such as explosions or fires. The relevance of this research is increasing along with the global growth of electric vehicles, including in Indonesia. The research method involves numerical simulations with variations in the thickness of the aluminum foam sandwich, namely 10 mm, 15 mm, and 20 mm. Data from the simulations were then validated through vibration tests in the laboratory to compare their agreement with experimental data. Initial simulations were performed without using aluminum foam to determine the baseline values, and then compared with simulations using foam. The results showed that without aluminum foam, the acceleration reached 8409.86 m/s², displacement 0.0122 m, and velocity 10.36 m/s. Meanwhile, with the use of 20 mm aluminum foam, the acceleration, displacement, and velocity were reduced to 1739.96 m/s², 0.0041 m, and 3.00 m/s, respectively. The conclusion of this study is that the addition of sandwich aluminum foam significantly reduces vibration in electric car batteries, thereby improving the safety and reliability of electric vehicles.

Abstract: Traditional cooking methods and rocket stoves based on natural principles release high emissions due to the inefficient combustion of solid biomass fuel. Steam injection in combustion enhances combustion efficiency and reduces pollutant emissions. This technique improves stove performance and efficiency without relying on electrical power by leveraging the heat energy from the biomass stove for steam injection. This study evaluates the performance of a biomass stove using steam injection with Casuarina equisetifolia wood as fuel. The experiment varied the volume of steam injection water: 500 ml, 800 ml, and 1,200 ml. Among these, the 500 ml injection volume achieved the fastest boiling time during the high-power phase, taking 11 minutes and 6 seconds, with a thermal power output of 5.8708 kcal/s. The highest thermal efficiency of 51% was observed with the 1,200 ml water injection, accompanied by a specific fuel consumption of 0.0008 kg/s. The best CO emission performance, at 0.77% (7.7 g/kg), was achieved with the 500 ml water injection volume. These results highlight the potential of steam-injected biomass stoves for practical cooking applications.

Abstract: The utilisation of metal coating technology, including reduced graphene oxide (rGO), has garnered significant interest due to its potential for developing high-performance materials. Our study examined three distinct techniques for depositing rGO coatings: electromagnetic wave plasma, RF sputtering, and high-temperature vacuum evaporation. We compared how well this technique works for making consistent and high-quality metal coatings with reduced graphene oxide (rGO). The electromagnetic wave plasma technique was able to produce rGO layers that were evenly thick and well spread out. This technique facilitates meticulous manipulation of process variables, enabling the fabrication of coatings with the intended microstructure. The RF sputtering approach offers benefits in producing layers that exhibit robust adhesion between reduced graphene oxide (rGO) and metal substrates, leading to compact and homogeneous structures with precise control over surface shape. High-temperature vacuum evaporators can generate fragile layers with exceptional purity, rendering them well-suited for applications requiring exact layer thickness and meticulous control over chemical composition. This study the benefits and drawbacks of each coating method using reduced graphene oxide (rGO) and its potential application in creating novel materials. By better understanding the unique features and effectiveness of each method, we can improve the design and production of metal coatings with reduced graphene oxide (rGO) for future uses, especially in generators

Abstract: Optical fiber technology has developed quite rapidly. However, one of problems on fiber optics that is losses consequence attenuation connection which caused by the core material of the optical fiber (core) is dirty and the light is bent in the wrong direction. Optical fiber splicing in this study used a Sumitomo Z1C Optical Fiber Fusion Splicer, while to measure the splicing results an Optical Time Domain Reflectometer (OTDR) was used. Yokogawa AQ1000 with single mode fiber optic type. The aim of this research is to minimize the amount of connection attenuation based on cleanliness and cutting fiber optics on moment connection. Based on testing which has been carried out, it is obtained that the difference in attenuation results is due to the attenuation value measured by the fusion splicer being mark estimation loss be measured by sensors camera namely a microscope objectives lenses whereas results the attenuation value measured by the OTDR is a real value measured using an APD (Avalanche Photodiode) sensor. For quality connection most Good obtained connection attenuation most small as big as 0.00 dB on fusion splicer And measurement OTDR of 0.103 dB with cleaning fiber optics which it has been peeled using tissue and alcohol, then immediately connected and used for cutting techniques fiber optics most good attenuation produce most small that is 0.00 dB on fusion splicer and 0.098 dB in OTDR measurements by cutting optical fiber with a fiber cleaver placed on a flat surface with a high fiber cleaver knife speed, namely within 0.16 seconds.

Abstract: This paper provides an analysis of recent advancements and potential applications of blockchain technology in microgrids. Microgrids are small-scale electrical networks that can operate autonomously or integrate with a central power grid, offering enhanced security, resilience, and efficiency in energy utilization through blockchain implementation. Blockchain's decentralization, transparency, and security capabilities present innovative solutions for optimizing microgrid operations. This study explores blockchain applications in microgrids, addressing fundamental principles, prior research, existing gaps, case studies, technical and regulatory challenges, and future optimization opportunities. The findings indicate that while blockchain adoption in microgrids is still in its early stages, it holds significant promise for transforming energy systems. With continuous technological advancements and supportive policy frameworks, blockchain can facilitate the transition towards a more sustainable and efficient energy future. Furthermore, the global proliferation of blockchain-based microgrids highlights the need for Indonesia, endowed with abundant renewable energy resources, to enact regulatory measures supporting this emerging technology