Using renewable energy sources, such as palm oil-based biodiesel, in diesel engines has demonstrated considerable potential. However, assessing their effectiveness requires comprehensive performance tests to facilitate economic evaluations, particularly in measuring fuel consumption. This study focuses on the gravimetric method for quantifying fuel consumption using a 40 kg scale. This research aims to develop a cost-effective and user-friendly method of the field and laboratory measurement technique. A load cell was integrated with an HX711 signal amplifier and a data processor to achieve this objective, complemented by an Arduino Uno data acquisition program. The study collected data during idle operating conditions at 700 rpm and New European Driving Cycle (NEDC) simulations in passenger cars fueled by biodiesel blend fuel with a volume ratio of 30% (B30). The recorded data was meticulously analyzed and presented using spreadsheet software. The results of the scale compared to the flow meter revealed fuel consumption rates in idle tests of 3.475 and 3.464 g/s, respectively. The result demonstrated a mere 0.32% difference between this developed method and conventional approaches in the idle test and a 5.8% difference in the NEDC cycle test. These findings reveal the viability and accuracy of the gravimetric technique, offering a cost-effective solution of real-world fuel consumption measurement in the pursuit of sustainable energy solutions.

An experimental investigation was performed to find out the viscosity of additive and biodiesel fuel mixture in the temperature range from 283 K to 318 K. Solutions to reduce the viscosity of biodiesel is to add the biodiesel with some additive. The viscosity was measured using a Brookfield Rheometer DV-II. The additives were the generic additive (Diethyl Ether/DDE) and the commercial additive Viscoplex 10-330 CFI. Each biodiesel blends had a concentration of the mixture: 0.0; 0.25; 0.5; 0.75; 1.0; and 1.25% vol. Temperature of biodiesel was controlled from 40°C to 0°C. The viscosity of biodiesel and additive mixture at a constant temperature can be approximated by a polynomial equation and at a constant concentration by exponential equation. The optimum mixture is at 0.75% for diethyl ether and 0.5% for viscoplex.

This study assesses Sick Building Syndrome (SBS) symptoms and Indoor Air Quality (IAQ) parameters among hospital ward staff. Utilizing a thorough methodology, a questionnaire survey and IAQ monitoring were conducted, aligning with Department of Occupational Safety and Health (DOSH) guidelines. IAQ parameters are generally within limits, except for relative humidity which recorded values of 73.09-75.23% for Ward 16 and 62.33-71.13% for Ward 18. Respondents expressed concerns about room conditions, including temperature variations, unpleasant odours, and noise. Fatigue, difficulties concentrating, and various respiratory symptoms were prevalent, suggesting potential health issues linked to indoor pollutants. The findings underscore the urgency of addressing IAQ concerns to improve the well-being of patients and healthcare workers.

This study investigates the relationship between Indoor Air Quality (IAQ) and air duct cleanliness, addressing the rising concern for human well-being. Airborne contaminants like dust, mold, and bacteria are identified as significant threats to IAQ, with potential health consequences. The study will also explore the several established safety and health guidelines and duct characteristics that influenced IAQ. Consequently, the primary research goal is to examine the relationship between duct cleanliness and airborne contaminants in the building environment and determine whether air duct cleaning effectively reduces these contaminants. By thoroughly reviewing studies and established standards, we examine IAQ contaminants and explore the effects of duct cleaning, along with its potential health advantages. Findings emphasize duct cleaning's potential to enhance IAQ, reduce exposure to pollutants, and its importance for building owners, facility managers, and stakeholders in safeguarding occupants' health and comfort.

Energy demand in Indonesia continues to increase, in line with the government's efforts to balance economic and population growth. In this context, the government-designed electricity supply policy prioritizes the use of coal as the main source of energy until 2050. Power plants face challenges in asset management, particularly in the replacement and maintenance of equipment such as condensers. This study aims to determine the economic life of condensers in Steam Power Plants (PLTU) with a capacity of 300 MW, as well as analyze the life cycle costs using the Simple Life Cycle Cost Management (LCCM) method. This method considers direct and indirect costs in decision-making related to equipment maintenance and replacement. The study also identified factors that affect the operational efficiency of the condenser, including backpressure and operational conditions. The results of the analysis show that careful monitoring and evaluation of the economic life of the condenser can optimize operating costs and improve the energy efficiency of the generation system. This study provides strategic recommendations for asset management in power generation, prioritizing a holistic approach in decision-making related to equipment maintenance and replacement. Thus, this research is expected to contribute to the development of more efficient energy policies in Indonesia.

Kajian ini bertujuan untuk mengetahui tingkat kecepatan pemisahan (creaming velocity) antara dua fluida yang berfasa sama namun memiliki perbedaan densitas. Kajian ini dilakukan secara eksperimental dengan mengamati dan mengukur waktu pisah (settling time) pada tabung kaca dengan variasi diameter.Pengukuran waktu pisah dilakukan lima kali untuk setiap diameter tabung. Waktu pisah yang di peroleh digunakan sebagai dasar untuk menghitung diameter tetesan/droplet, konsentrasi tetesan, kecepatan pemisahan/creaming velocity dan Vstokes. Hasil perhitungan yang di peroleh diploting untuk membandingkan nilai konsentrasi tetesan (droplet consentration/Φ) terhadap kecepatan pemisahan (creaming velocity) pada campuran biodiesel/gliserin dan untuk mencari nilai Φc (fraksi volume fase biodiesel yang terdispersi rapat dalam gliserin/konsentrasi tetesan) dan k (konstanta pemisahan). Dari penelitian ini dapat disimpulkan bahwa semakin tinggi nilai konsentrasi tetesan (Φ) maka kecepatan pemisahannya (V cream) akan semakin berkurang dan dari persamaan Hunter bahwa V = Vstokes(1- )k.Φc , maka didapatkan nilai k dan Φc masing – masing adalah (5,1 ; 0,6 ; 1,2) dan (0,461 ; 0,9 ; 0,69) pada percobaan I, II, III dengan diameter tabung (1,3 ; 2,8 ; 3,9) cm.