Forum Teknik

Optimasi Perancangan Rangka Airboat menggunakan metode Quality Function Deployment dan Full Factorial Design

2025-01-21T13:26:28+07:00

An airboat is a versatile vehicle designed for operation on both land and shallow waters, powered by an air propeller. These vessels are commonly utilized for recreational purposes, search and rescue operations, military applications, and transportation in remote areas. As development in these regions progresses, the demand for airboats has grown. However, challenges such as limited carrying capacity and inadequate damping call for innovations in frame design. This study aims to develop a new frame design that is both more robust and reliable, employing the Quality Function Deployment (QFD) method in conjunction with Full Factorial Design. The factors considered include passenger capacity, design model, and material. The findings indicate that the optimal design is achieved with a combination of carbon steel material, a rectangular ISO 10799 design model, and a capacity to accommodate three passengers with luggage. This configuration yields a von Mises stress of 29.927 MPa and a safety factor of 11.6952.

Identifikasi Erupsi Vulkanik menggunakan Vulkanostratigrafi pada Formasi Semilir Studi Kasus Desa Srimulyo, Kecamatan Piyungan, Kabupaten Bantul, Provinsi Daerah Istimewa Yogyakarta

2025-01-21T13:19:45+07:00

In Java, volcaniclastic rocks and thick volcaniclastic sequences were produced by volcanic activity that has occurred since the Eocene. The study conducted at the Srimulyo volcaniclastic rock outcrop, Piyungan, Bantul, Yogyakarta, enabled the identification of geometric and architectural elements of the rock structure, depositional system, and environment. This study quantifies the distribution and variation of lithofacies, sedimentation dynamics, rock properties, and rock origin using stratigraphic measurements and petrographic analysis. The study area consists of 6 facies of volcaniclastic rocks that have stratigraphic relationships with siliciclastic and mixed siliciclastic rocks. In addition, the results show that the study area experienced two periods of explosive eruptions of the Plinian eruption type, which produced primary and secondary pyroclastic flows.

Faktor Pembentukan dan Karakteristik Kekar Tiang di Desa Sembowo, Kecamatan Klepu, Kabupaten Pacitan, Jawa Timur, Indonesia

2025-01-21T13:24:47+07:00

The columnar joints structure in Sembowo Village, Pacitan District, East Java is composed of andesite lithology with a mineralogical composition dominated by pyroxene and plagioclase phenocrysts with a cryptocrystalline and glass matrix, but olivine is not found. On the other hand, there are altered minerals in the form of chlorite in lithological samples which show alterations in the lithology. The presence of a very fine matrix (<1mm) indicates the rapid freezing of magma. The percentage of phenocryst presence in the lithology sample is about <40% and the pilotaxitic texture also indicates that the columnar joint is composed of extrusive lava flows. In terms of outcrops, the columnar joints in this research area have characteristics such as a relatively small diameter of about 10-25 cm, dominantly having an irregular fracture shape, and the height of columnar joints reaches ±45 meters. The thickness of the lava, which is quite thick and consists of only one unit of colonnade, is classified as having a lava flow of the single unit flow (SUF) type. Therefore, the formation of columnar joints at the research site is caused by two main factors: the geometry of the magma body in the form of a lava flow and the chemical composition of the constituent lithology, which is intermediate magma.

Analisis Perbandingan Hasil Simulasi Genangan Rob Berdasarkan DEM Foto Udara dan Dem Lidar

2025-01-21T13:28:41+07:00

Tidal flooding occurs due to fluctuations in sea level influenced by the gravitational forces of celestial bodies, particularly the moon and the sun. In Central Java, Indonesia, the Tambak Lorok area in Semarang frequently faces tidal floods, leading to considerable economic and social losses if not properly managed. To mitigate these risks, it is essential to simulate tidal runoff areas (inundation zones) using the latest Digital Elevation Model (DEM) data. High-resolution DEMs can be produced effectively through photogrammetry and LiDAR UAV techniques, but differences in accuracy and ground penetration between these methods can impact inundation simulations. The complex land cover in Tambak Lorok additionally affects height extraction and tidal flow distribution. This study compares tidal inundation simulations using DEM data from aerial photography and LiDAR. Employing neighborhood operations and iterative methods for simulation, seven sea-level rise scenarios were analyzed: 0.5 m, 0.75 m, 1 m, 1.25 m, 1.5 m, 1.75 m, and 2 m. The inundation areas were calculated, and a concordance ratio (CR) was established to assess the similarity of the results. The average CR across the scenarios was 92.31%, indicating consistency between the two data sources, although the 0.5 m scenario showed an underestimate from the aerial photo DEM compared to LiDAR. This variation was attributed to differing penetration levels, especially along the eastern riverbank of the study area.

Alternatif Metode Penentuan Karakteristik Litofasies Berdasarkan Gabungan Data Wireline Log Pada Reservoir LRLC Formasi Upper Sihapas, Lapangan ARS, Cekungan Sumatra Tengah

2025-01-21T13:25:47+07:00

Lithofacies analysis is one of the initial studies in oil and gas exploration to determine the type and quality of a reservoir. Various lithofacies analysis methods have been developed to increase confidence in the analysis results. One method that can be developed is cluster analysis based on multiple wireline log data. This cluster analysis has the advantage of knowing the type of lithofacies in intervals that do not have core rock data. The results of the lithofacies analysis of the core rocks show the presence of four lithofacies, namely shale inserted with clayey sandstone (A), clayey sandstone inserted with shale (B), clayey sandstone and shale (C), and shale (D). This study uses gamma ray log, density log, and neutron log data in cluster analysis to show the physical characteristics of a rock. The three log data cluster analysis produced a lithofacies log curve consisting of four data groups. The lithofacies log curves resulting from the cluster analysis show agreement with the three core rock lithofacies: A, B, and C. The difference in lithofacies D between the cluster analysis and the core rock is due to geometry and the level of detail of the number of data groups in the cluster analysis.