This study aims to determine the exhaust gas pressure and flow velocity of the conical silencer muffler compared to various types of muffler commonly used in the market. Conical silencer muffler developed to obtain high performance and low noise for internal combustion engine. Analysis of flow velocity and pressure used CFD method, the input fluid velocity parameter of 12000 mm/s with Siemens NX 10 software. Four exhaust mufflers have been designed in this study, conical silencer muffler, free flow muffler, a db killer installed in free flow muffler, and OEM muffler. The results of the analysis that have been carried out shown the conical silencer muffler has a max flow rate of 31200 mm/s with a pressure of 0.713 KPa, the OEM muffler has a flow rate of 47500 mm/s with a pressure of 4.250 KPa, the free flow muffler has a flow rate of 26500 mm/s with a pressure of 0.471 KPa, while the free flow muffler with db killer has a flow rate of 123000 mm/s with a pressure of 28.4 KPa. Based on these data, the performance of the free flow muffler was used as a benchmark for the performance of other mufflers. Conical silencer muffler has a flow difference of 4700 mm/s (18%) and a pressure difference of 0.24 KPa (51%) higher than free flow muffler, OEM muffler has a higher flow difference of 21000 mm/s (79%) and a pressure difference of 3.78 KPa (802%), free flow muffler with db killer has a higher flow difference of 96500 mm/s (364%) and a pressure difference of 27.93 KPa (5930%) compared to free flow muffler. Based on these data, it can be concluded the conical silencer muffler can generate performance near to the free flow muffler.

The community service programme in Karangharjo Village, Rembang Regency, was implemented through a pilot workshop on ship repair as an effort to improve the capacity and technical skills of coastal fishermen. The main problems faced by local fishermen were a lack of understanding of ship diesel engine maintenance, limited access to repair workshops, and the use of manual techniques that risked engine damage. This community service activity was designed with a group-based approach, local potential, and comprehensive intervention, including training in engine maintenance and repair, practical use of workshop equipment, tool management inventory, and the construction of a community-based shipyard workshop. The results of the activity showed an increase in fishermen's skills in performing routine maintenance, managing workshop equipment, and readiness to manage workshops independently. This programme supports the achievement of the Sustainable Development Goals (SDGs), particularly SDG 1 (No Poverty), SDG 8 (Decent Work and Economic Growth), SDG 9 (Industry, Innovation and Infrastructure), and SDG 14 (Life Below Water). With the establishment of synergy between universities, village governments, and fishermen's groups, this workshop initiative is expected to increase the independence, business sustainability, and economic resilience of coastal communities.

Biomass Gasification is an attractive renewable energy technology. Biomass waste, as well as a renewable energy source and also, could be used as raw material to produce syngas. Nevertheless, the biomass is containing tar. The downdraft gasifier is considered to produce less tar, however, the syngas still containing tar which makes blocking and fouling of engines. Therefore, reducing tar is needed, one of them using a wet scrubber that is technically and economically viable to obtain clean syngas. Wet scrubber using absorbent to make absorption. This paper investigated the effect of variations on the type of absorbent in the scrubber to reduce tar in syngas. The absorbent used is vegetable glycerine food grade as a solvent and coconut shell charcoal with a mesh of 10-20 as a packing material. There are two variations of absorbent. Firstly, using only vegetable glycerine food grade and the second using vegetable glycerine food grade and coconut shell charcoal. Each variation was given a vegetable glycerine food-grade discharge of 31.5 ml/s. The results showed that variations in the absorbent of vegetable glycerine food grade and coconut shell charcoal resulted in higher tar removal rates is 100% in Acids, 51.88% in Furans, 65.04% in Alcohols, 35.12% in Ketones.

Penelitian ini bertujuan untuk melakukan pengamatan pola aliran plug pada pipa horisontal dengan metode image processing dengan variasi kecepatan superfisial udara. Selain itu, untuk mengetahui pengaruh kecepatan superfisial udara terhadap karakteristik dan parameter pola aliran plug pada aliran air-udara pipa horisontal yang meliputi fraksi hampa, frekuensi plug, kecepatan plug, dan panjang kantung udara plug, panjang liquid plug. Metode yang digunakan adalah menggunakan metode image processing. Pengambilan data menggunakan high speed video camera dengan kecepatan 400 fps menggunakan pipa acrylic dengan diameter dalam 19 mm dengan pengambilan data pada kondisi aliran fully developed yaitu pada jarak 200D. Selanjutnya dianalisa dengan metode image processing dengan menggunakan software CorelDraw X7. Hasil penelitian diperoleh kecepatan superfisial minyak mentah-air yang optimal untuk mengurangi dampak aliran plug yang akan menjadi aliran slug pada pengaplikasian industri melalui perubahan karakteristik dan parameter pola aliran tersebut. Hal tersebut ditunjukkan dengan hasil pengolahan data dari perhitungan dan visualisasi image processing pada karakteristik dan parameter pola aliran

The Student Organization Capacity Building Program (PPK- ORMAWA) is a program designed to strengthen the capacity of student organizations in community service in Tambakrejo Village, Semarang City. This program aims to identify important issues that affect food security, financial literacy, waste management, and MSME empowerment, especially in Tambakrejo Village, through the application of six basic literacies. The approach used involves the stages of planning, implementation, and monitoring to solve problems in the village. The planning and preparation process is carried out in coordination with village officials, community leaders, and related partners, with a focus on solving problems through socialization regarding green mussel cultivation with a smart harvest system in Tambakrejo Village. Monitoring and evaluation are carried out after the program is implemented to collect feedback and make improvements. This monitoring and evaluation is an important part of ensuring the success and effectiveness of the program. Through this activity, the team succeeded in strengthening the capacity of the Tambakrejo Village community and providing a positive impact on literacy, the environment, and the local economy.

The strategy of design engineering is very important to produce the modernization of technology. The propeller is one of crucial part in the marine design especially for the marine transportation especially for traditional fishing vessel. In this paper, presents a study for analysis of the propeller performance by using numerical simulation in the computational fluid dynamics (CFD). Since the development of CFD simulation, still facing several problems to solve the CFD analysis. The OpenFOAM is open source CFD tool used in this study in order to investigate the propeller performances. OpenFOAM is implemented for open water performances of KCS propeller (KP505). Reynold-averaged Navier Stokes equations (RANS) was applied to estimate the turbulence of K-w SST model. Unstructured mesh in this simulation was employing a hexahedral mesh as mesh generation. The multiple rotating frame (MRF) was produced as method to analysis of propeller performances. The velocity inlet and pressure outlet were put for inflow and outflow boundaries. The wall was set to a far-field boundary. The current study compared to the experimental result for the thrust and torque coefficient to validate the propeller performances. By using MRF technique, the simulation of interaction for the propeller with a relative error less than 2%. Thus, The MRF technique can be used for the practical technique to simulate the ship propeller model especially for the moving multiple zones.