EPI International Journal of Engineering

A Field study on oscillating pontoon wave energy converter (WEC) performance in nearby Muarabaru, North Jakarta.

abdul - hamid — 2026-05-31

Abstract

Two-thirds of Indonesia's territory is sea waters with different wave heights according to local geographical conditions. And only with the mastery of technology, wave energy can be converted into electrical energy which is priceless. This paper aims to determine the performance of a wave energy converter (WEC) device based on a damped forced vibration system. The WEC set consists of a marine structure measuring 3.00 meters high, 2.00 meters wide, and 2.00 meters long; a two-dimensional heaving-pitching gearbox as a power take-off (PTO) and a pontoon type “H” beam measuring 2.96 meters long, 0.92 meters wide. The research was conducted by field testing on a 50-meter coastline measured from the low tide shoreline of nearby Muarabaru, North Jakarta, for 24 hours from high tide to the next which is done every 6 hours. The research results show that:

The output power generated by the heaving motion is = 36.25 Watts,
The efficiency value due to heaving = 25.87%
The output power generated by the pitching motion is = 37.9 Watt,
The efficiency value due to pitching = 27.30%

Keywords: damped forced vibration system; performance of WEC; pontoon type "H" beam; power take-off (PTO); two-dimensional heaving-pitching gearbox

SMART SENSING FLUID FLOW DEVICE FOR MID STREAM PROCESS IN OIL AND GAS INDUSTRY

Khushal Khan Kakar — 2026-05-31

In petroleum industries the storage tanks have a real problem of handling and management of fuel quantity. Various devices are used to
monitor fuel quantity in storage tanks or boozers, such as flow sensors, level sensors, float switches, analog meters, most commonly probes
and manuals. In this regard, we propose digital system to find out the amount of fuel in liters or milliliters in the storage tank.
Main objective of this project is to develop a digital display which portrays the precise quantity of fuel being poured into a storage tank or
fuel container. This display will help to verify the amount of fuel filled at petrol stations. Currently, the manual process of recording fuel
readings is time-consuming and tedious. By implementing this proposed system, customers will save time by receiving an exact reading
without the need for double-checking the tank or container.
Lately, there have been frequent reports of fuel station fraud, where stations have pumps that display an inflated amount of fuel filled, while
the actual quantity poured into the customer's vehicle is much less. In Pakistan, most cars are equipped with analog fuel meters, which do
not provide an accurate measure of the fuel level or allow customers to verify the amount of fuel filled at a station.

Determination of Sustainable Supply Chain Strategy in Natural Gas Transition as a Substitute for Subsidized Household LPG Using FAHP and TOPSIS Method

Avriska Padmasari — 2026-06-04

The high dependency on subsidized LPG imports and the increasing demand for cleaner energy encourage the utilization of natural gas as an alternative household energy source in Indonesia. This study aims to determine the most appropriate sustainable supply chain strategy in supporting the transition of natural gas as a substitute for subsidized household LPG at Company XYZ. The research applies a Multi-Criteria Decision Making approach using Fuzzy Analytical Hierarchy Process (FAHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). FAHP is used to determine the weight of criteria based on economic, environmental, and social aspects, while TOPSIS is applied to rank the alternative strategies. The results indicate that the strategy of infrastructure integration and gas distribution efficiency achieved the highest preference value of 0.9712, making it the most recommended strategy. The selected strategy is considered capable of improving distribution efficiency, expanding household gas network utilization, and reducing dependency on subsidized LPG. Therefore, the implementation of sustainable supply chain management in the gas sector can support energy transition and improve the effectiveness of household gas distribution systems.

Performance of Porous Asphalt Mixtures Using De-oiled Bleaching Earth (DBE) Filler With University Of New Hampshire Stormwater Center (UNHSC) Gradation

Yafi Argyan Setiyanda Farrel — 2026-06-04

Porous asphalt is an asphalt mixture designed with open-graded composite material and serves to drain water on the road surface into the pore of the mixture. The coarse aggregate composition that dominates the porous asphalt mixture makes it have low stability, in this research, DBE was used as a filler replacement to improve the performance of the mixture. This study aims to determine the performance of porous asphalt mixture using DBE filler with UNHSC gradation. Variations of DBE filler content used were 0%, 25%, 50%, 75%, and 100% by weight of filler. Test specimens with DBE filler were made using optimum asphalt content (KAO), with tests including Marshall test, binder drain down, permeability, and cantabro loss. The results showed that the performance of porous asphalt mixtures with DBE fillers obtained stability and VIM values decreased and flow values increased. In the permeability test, the highest value was 0.214 cm/s at 0% DBE, the highest cantabro loss value was 28.07% at 100% DBE, and the highest binder drain-down value was 0.24% at 0% DBE. The results of the research can conclude that the use of DBE as a filler can reduce the performance of porous asphalt mixtures.

Analysis and Optimization of Warehouse Sustainability Using the Sustainable Value Stream Mapping (SUS-VSM) Method at PT XYZ

Friska Aryanti — 2026-06-05

Warehouse operations are a critical component of the supply chain system as they manage material flow before entering the production process. The Central Warehouse handles high-volume material operations, requiring an efficient and sustainable warehousing system to support Environmental, Social, and Governance (ESG) targets and the Net Zero Emission 2060 initiative. This study aims to analyze and optimize sustainable warehouse processes using the Sustainable Value Stream Mapping (SUS-VSM) method integrated with RFID technology. The research methodology includes mapping the current state of SUS-VSM, classifying activities into value-added (VA), necessary non-value-added (NNVA), and non-value-added (NVA), waste analysis, root cause identification using the Five-Whys method, and designing the future state of SUS-VSM. The results indicate that the total lead time of the warehouse process is 4,516.31 minutes, with a value-added time of 36.59 minutes and a Process Cycle Efficiency (PCE) of 0.81%. The dominant wastes identified include waiting, transportation, motion, inventory, and overprocessing, which are caused by the lack of system integration, reliance on physical documents, and manual verification processes. Proposed improvements such as the implementation of RFID, a Warehouse Management System (WMS), document digitalization, and material flow optimization reduce lead time to 4,395.19 minutes and increase PCE to 0.83%, while also improving sustainability indicators including waste efficiency, energy process, safety, and time efficiency. The findings demonstrate that the implementation of RFID-based SUS-VSM enhances warehouse operational efficiency while supporting sustainable warehousing systems