Journal of Applied Science, Engineering and Technology

Comparison of Airflow Velocity Distribution at the Inlet in Single and Dual Inlet Cabinet Dryer: A CFD Study

Angga Darma Prabowo — Sat, 28 Jun 2025 00:00:00 +0000

This study explores how airflow velocity is distributed in cabinet dryers with single and dual inlet systems, using Computational Fluid Dynamics (CFD) simulations. The goal was to compare how different inlet configurations affect airflow uniformity and drying performance across various rack levels. We tested four dual inlet setups with varying mass flow ratios (50%/50%, 40%/60%, 30%/70%, and 20%/80%) and compared them to a single inlet system. The results show that the single inlet configuration creates uneven airflow, with higher velocities at the top racks and lower velocities at the bottom, leading to inconsistent drying. On the other hand, dual inlet systems provide more even airflow, with the 50%/50% configuration being the most balanced. Even the more uneven dual inlet setups (such as the 20%/80% ratio) still performed better than the single inlet in terms of airflow consistency and drying efficiency. Overall, dual inlet systems, especially those with balanced airflow, enhance drying efficiency by ensuring more uniform airflow throughout the dryer. Further research could focus on optimizing these dual inlet systems for even better performance.

Potential of Fecal Sludge Briquette as Biofuel: A Review

Siti Nurul Khotimah — Sat, 28 Jun 2025 00:00:00 +0000

Fecal sludge from fecal wastewater treatment may create problem to environment and human health as Its high production number and its hazardous content. The high volume of fecal sludge production not only reflects the scale of sanitation needs but also signifies a substantial opportunity for renewable energy generation by transforming the fecal sludge to briquettes. This article is a critical review to evaluate the potential of fecal sludge, especially about its characteristics as a raw material, the method to create the briquettes, the briquette composition and finally its performance regarding the fecal sludge composition. Interestingly, even though fecal sludge is hazardous as the high pathogen level such as bacteria, worm and its egg, they will die after drying and carbonizing process. Hence, it will be safe to utilize the fecal sludge briquettes for human need. Comparing the calorific value of fecal sludge briquettes and coal (fossil fuel which has high energy value), the fecal sludge’s energy is about 3 times lower. This mean, if it is expected to achieve the fecal sludge briquettes’ calory equivalent to the coal, the number of fecal sludge briquettes should be multiplied 3 times.

Application of Failure Mode, Effect Analysis (FMEA) and Ishikawa Diagram in Determining the Damage Aspects and Maintenance Plan of Screw Feeder of Steam Power Plant Company

Akhmad Riszal, Eko Yohanes, A Yudi Eka Risano, Fauzi Ibrahim, Rizal Adi Saputra — Sat, 28 Jun 2025 00:00:00 +0000

The screw feeder is a commonly used material transporter in various industries due to its ability to move large quantities of material and operate for extended periods. In practice, unexpected damage often occurs, requiring component replacements outside regular maintenance schedules. To improve reliability, Ishikawa diagrams are used to identify root causes of damage, while the FMEA method helps analyze failure risks and schedule preventive maintenance. This study found that the main causes of screw coal feeder damage are human error, mechanical issues, materials, and methods. Recommended actions include regular inspections for wear and proper lubrication to maintain performance. Based on reliability analysis, the screw feeder leaf has a reliability rate of 95.3% with a mean time between failure (MTBF) of 116.66 hours. The casing has a reliability rate of 94.6% and an MTBF of 142.85 hours. Implementing Ishikawa and FMEA methods at PT XYZ’s coal-fired power plant (PLTU) enables more effective and planned maintenance. This approach minimizes unexpected breakdowns, improves component reliability, and ensures smoother operations.

Magnesium and its alloys as Biomaterial for bone repair: advances, challenges and future direction in mechanical and tissue engineering research

Noor Jasmawati, Nafrizal, Zulhanif, Fauzi Ibrahim, Irza Sukmana — Sat, 28 Jun 2025 00:00:00 +0000

Interest in the application of biodegradable bone screw is driven by the increasing knowledge on biomedical materials and tissue engineering field. Currently, various polymeric- as well as metallic-based materials have been used as degradable bone screw. Biodegradable material is a desirable feature for bone screw since the goal is that it uses as a temporary structure holding a growing bone tissues until the bone fracture has sufficiently healed. Among others, magnesium and its alloys have a potential chance to serve as biodegradable bone screw applications, as it has mechanical properties similar to natural bone, lightweight, and biocompatible approved. This article aims to report current development and future potential use of magnesium-based metal for bone screw application. Techniques on manufacturing process, mechanical performance, and biocompatibility assessment of magnesium and its alloys are highlighted.

Performance Evaluation of the Drainage System at FMIPA University of Lampung under Extreme Rainfall Conditions

Sat, 28 Jun 2025 00:00:00 +0000

Urban drainage systems are facing increasing challenges due to the intensification of extreme rainfall caused by climate change and rapid urban development. This study aims to evaluate the performance of the drainage system at the Faculty of Mathematics and Natural Sciences (FMIPA), University of Lampung, in managing flood discharge during extreme rainfall events. Using 24 years of rainfall data, the design rainfall was calculated using the Gumbel distribution and converted into short-duration intensity using the Mononobe method. Peak discharge was estimated with the Rational method, and compared against the channel capacity calculated using Manning’s equation. The results showed that the designed trapezoidal drainage channel (0.4 m × 1.2 m × 0.6 m) could safely convey runoff from a 25-year return period. However, field observations revealed that the installed channel at several points, particularly DN65 (0.35 m × 0.40 m), was undersized and could not accommodate the peak flow. This discrepancy highlights the need for upgrading existing drainage infrastructure on campus.