Muhammadiyah University of Magelang

The utilization of waste cooking oil (WCO) as a sustainable alternative fuel has gained attention due to its economic and environmental benefits. However, its high viscosity affects combustion efficiency, necessitating optimization techniques such as fuel blending and preheating. This study investigated the effect of preheating WCO-diesel blends on engine performance and fuel consumption using Response Surface Methodology (RSM). A four-stroke diesel engine was tested with different fuel mixtures (D100, B25, B50) and preheating temperatures (50 degrees C, 60 degrees C, 70 degrees C, and 80 degrees C). The results indicated that preheating improved fuel atomization and combustion efficiency, particularly for biodiesel blends. The optimal conditions, determined using RSM, were found at 2779.57 RPM and 1.07 degrees C preheating temperature with D100 fuel, yielding maximum power (4489.51 kW), torque (1612 Nm), and minimum brake-specific fuel consumption (BSFC) of 117.995 g/kWh. The experimental validation confirmed the model's accuracy, with an error margin below 2%. These findings highlight the effectiveness of preheating in enhancing engine performance and fuel efficiency, contributing to the feasibility of WCO utilization in diesel engines.

PurposeThe purpose of this paper is to critically examine the legal and human rights implications of Indonesia's Government Regulation Number 56 / 2021, which authorizes the National Collective Management Organization (LMKn) to collect and distribute copyright royalties on behalf of copyright holders. This study explores whether such regulation is compatible with the principle of copyright as a private right under national law and human rights norms.Design/methodology/approachThis research adopts a normative legal methodology, focusing on statutory analysis. This study involves doctrinal examination of Indonesian copyright law, human rights instruments and the hierarchy of legal norms, supported by relevant legal literature and jurisprudence.FindingsThis study reveals that the establishment of LMKn and its extended authority under PP Number 56 / 2021 contradicts the core tenets of Law Number 28 of 2014 on Copyright, particularly the requirement of consent for economic rights delegation. It constitutes an unconstitutional encroachment on private rights, generates legal uncertainty and presents potential for administrative abuse because of overlapping functions with existing collective management organizations (LMKs).Practical implicationsThe findings of this study highlight the need for Indonesia to harmonize its copyright regulation with constitutional safeguards and international intellectual property frameworks. This paper recommends that any limitation on private rights must be explicitly regulated by statute and include sufficient checks and balances to ensure rights protection.Originality/valueThis paper provides a rare analysis of copyright governance in Indonesia through the lens of human rights and regulatory hierarchy, offering valuable insights into the legal risks of state-mandated collective management in emerging legal systems and situating Indonesia's case within broader debates on state intervention and private rights across the Global South.

The agricultural sector in many Muslim-majority developing countries is often hindered by limited capital and technological stagnation. This study aims to examine how the integration of productive waqf (Islamic social finance) and greenhouse technology can serve as a catalyst for local economic development. Design/methodology/approach: Adopting an inductive qualitative approach, this research utilizes a case study of the Premium Melon Waqf Greenhouse Cluster in Gunung Kidul, Indonesia. Data were collected through in-depth interviews, field observations, and document analysis, and were analyzed to identify economic impacts and operational strategies. Findings: The results indicate that the synergy between cash waqf and modern greenhouse technology creates a high-impact economic ecosystem. The program successfully transformed unproductive land into a high-yield asset producing 35–40 tons of premium melons annually per hectare. Financially, the project projects a break-even point within 2.5 years with substantial returns for investors. Socially, it creates a multiplier effect by raising local wages by 142.42% compared to conventional farming and fostering skill development.

Purpose This study aimed to investigate factors associated with viral load (VL) suppression among adults on Dolutegravir (DTG) and Efavirenz EFV)-based regimens antiretroviral therapy (ART) in Papua, Indonesia. Methods A cross-sectional study was conducted in a referral hospital, Papua Province. Results A total of 300 PLWH had either EFV-based regimens (50%) or DTG-based regimens (50%) equally. The majority PLWH had unsuppressed VL (70%). The multivariate analysis among PLWH with EFV-based regimens showed that having TB (AOR = 5.74; 95% CI = 2.30-14.31) was significantly associated with unsuppressed VL. Being better quality of mental health (MCS) (AOR=0.95; 95% CI =0.92-0.99) decreased the likelihood of unsuppressed VL. Moreover, those with DTG-based regimens TB (AOR = 2.60; 95% CI = 1.06-6.37) was significantly associated with unsuppressed VL. Being better quality of MCS (AOR=0.97; 95% CI =0.94-1.00), and those with high necessity of ART (AOR = 0.83; 95% CI = 0.72-0.95) decreased likelihood of unsuppressed VL. Conclusions There is a need to raise awareness about increasing the number of PLWH with VL suppression, particularly those with DTG-based regimens. This study suggests that during the launch of new ART, healthcare providers must be educated to increase their knowledge of the new therapy.

This study aims to examine the impact of internal factors on the profitability of Islamic Commercial Banks operating in Indonesia during the 2020–2023 period. Bank profitability is measured using Return on Assets (ROA), which reflects a bank's ability to generate earnings from its total assets. The independent variables analyzed in this study include the Capital Adequacy Ratio (CAR), Financing to Deposit Ratio (FDR), Non-Performing Financing (NPF), and the Operating Expenses to Operating Income Ratio (BOPO). These variables were selected because they represent key aspects of capital adequacy, liquidity, financing quality, and operational efficiency that may influence a bank's financial performance. The population consists of all Islamic Commercial Banks registered with and supervised by the Financial Services Authority (OJK). Of the 13 banks in the population, 11 met the purposive sampling criteria and were selected as the research sample. This study utilizes secondary data obtained from annual financial reports. Multiple linear regression analysis was employed to examine the relationships between the research variables. The findings reveal that CAR and BOPO have a significant negative effect on ROA. In contrast, FDR has a significant positive effect on ROA, while NPF is not found to have a significant effect on the profitability of Islamic Commercial Banks.