Tree is an important part of urban ecology. However, the condition of trees from time to time should be routinely observed in order to avoid the case of falling trees that often take casualties. There are several types of tree defects that can trigger the fall of a tree, such as decay, cancer, crack, etc. So far, there have been several methods to detect such defects as an early indicator of tree condition, for example by acoustic tomography, intrusive indentation, etc. In this study, a detection method is proposed by using natural frequency analysis (modal analysis) of a tree. The selected tree is palm tree. As an initial step, an analysis is required to determine the changes occurring in the natural frequency of palm trees that are affected by, 1) geometric aspects, such as diameter and tree height, 2) morphological aspects, such as the presence or absence of decay and its position on the tree. Natural frequency analysis is done with the help of FEM software. The result shows that the change in natural frequency is not very significant, in the range of 10% to 11%. Therefore, to be able to identify the condition of a tree, further research is needed.
Department of Mechanical Engineering, Universitas Riau, Indonesia
Riau Province is one of the largest palm oil producers in Indonesia. Pome of biogas is one form of renewable energy that can be utilized through biogas power plants. One of the biogas power plant in Riau is a Rama-Rama biogas power plant in Kampar. As a first step to improving power plant efficiency, this plant has been identified as the location of the largest loss in power plant by energy analysis. Energy analysis were performed for a gas engine with multiple cylinder on biogas power plant 835 kW otto cycle. The data from the plant’s record books using for this analysis. The result, each gas engine cylinder has different efficiency values. The highest and lowest energy efficiency of gas engine found in cylinder 11 and cylinder 7, respectively 56,12% and 56,02%. That different efficiency value occurred due to the fact that there are large temperature differences between the combustion process every cylinder and the working fluid.
Department of Mechanical Engineering, Universitas Riau, Indonesia
Ocean Thermal Energy Conversion (OTEC) is a clean marine renewable energy and alternative energy technology by utilizing temperature differences between warmer surface water and cold deep sea water to drive generators. Designing an OTEC system is challenging and the process requires detailed analysis and assessment. As Malaysia is an equatorial country located at a latitude of less than 20 degrees covered by the ocean with many islands with many topographic differences, OTEC is very compatible in Malaysia. In this paper, a feasibility study on the Sea Heat Energy Conversion in Layang-Layang Island and Kuala Baram, Malaysia has been discussed. The study found that Layang-Layang and Kuala Baram islands have great potential for the implementation of OTEC. Using field measurement data, 4 MW of electricity generated by OTEC is simulated as a case study. In addition, the OTEC system will produce fresh water through a distillation process. A numerical calculation and simulation analysis are presented in this study for both potential OTEC locations.
Naval Architecture and Offshore Engineering, School of Mechanical Engineering, Universiti Teknologi Malaysia, Malaysia
Ocean and Aerospace Engineering Research Institute, Indonesia
