The objective of this study is to examine the influence of reservoir temperature and injected formation brine salinity on oil recovery enhancement in brown oil fields. The study employed core flooding experiments using actual crude oil-producing porous media represented by core plugs, with recovery efficiency used as the main evaluation parameter. Flooding tests were conducted at 65°C, 75°C, 85°C, 95°C, and 105°C, representing reservoir temperatures of selected oil wells in the Upper Assam Basin. Initial water flooding was performed using low-salinity injection water of 897 ppm, followed by subsequent flooding using higher-salinity brine of 8000 ppm under the same temperature conditions. SARA analysis was also conducted to characterize the crude oil composition in terms of saturates, aromatics, resins, and asphaltenes. The results show that low-salinity flooding at 897 ppm produced oil recovery efficiencies of 51.47%, 44.21%, 89.89%, 36.33%, and 16.22% at 65°C, 75°C, 85°C, 95°C, and 105°C, respectively. When salinity was increased to 8000 ppm, the corresponding recovery efficiencies were 22.22%, 38.73%, 59.48%, 43.33%, and 4.98%. The highest oil recovery was achieved at 85°C for both salinity levels, with 89.89% recovery at 897 ppm and 59.48% at 8000 ppm. These findings indicate that reservoir temperature strongly affects crude oil recovery, while injection brine salinity also plays an important role. The study concludes that thermal and salinity-induced wettability alteration occurs during low-salinity water flooding, contributing to improved oil recovery in brown oilfields.
This study aims to identify bioactive compounds in seablite (Suaeda maritima) and develop seablite-based fish powder seasoning and marinade as an alternative low-sodium product. The chemical composition of edible seablite extract was analyzed using gas chromatography-mass spectrometry (GC-MS). Production process: powder preparation from dried seablite leaves and dried herbal powder including 5% lemongrass, 5% galangal, 5% garlic, and 5% kaffir lime leaves. Sensory evaluation and consumer acceptance test were conducted on 30 participants. GC-MS results showed that seablite extract contains phytochemicals, with the main components including phytol (43.19%), Myo-Inositol (7.06%), 9,12,15-Octadecatrienoic acid, (Z,Z,Z)- (6.32%), 9-Octadecenamide, (Z)- (5.36%) and Palmitoleamide (5.21%). The final product contained 320.87 kcal, 8.65 g protein, 68.62 g carbohydrate, 1.31 g fat, 15.19 g ash, 6.23 g water per 100 grams, and 46,431.25 mg/kg sodium. This formulation offers a healthier alternative with reduced sodium while maintaining flavor and nutritional value. The optimal formulation for seasoning and marinating fish powder consisted of 50% dried seablite powder. Sensory evaluation scores indicated consumer preferences ranging from “somewhat liked” to “quite liked.” These findings indicate that the developed seasoning powder is a promising, tasty, and healthier alternative for low-sodium fish products, while maintaining acceptable sensory qualities.
This study aims to optimize the rotor design of gravitational vortex turbines through an integrated approach combining parametric modeling, computational fluid dynamics (CFD), and experimental validation. The rotor geometry was formulated using velocity triangle theory and refined using a CFD-based evaluation of flow behavior across multiple turbulence models. To ensure accurate comparisons, experimental tests were conducted under controlled flow conditions, and mechanical losses due to bearing friction were measured and accounted for. The simulation results demonstrated strong agreement with empirical data, validating the effectiveness of the proposed design. By enhancing energy conversion efficiency while minimizing environmental impact, this research supports the development of decentralized, renewable micro-hydropower systems. The findings contribute to the advancement of Sustainable Development Goals (SDGs).
Spent coffee grounds still contain valuable bioactive compounds that can be valorized through kombucha fermentation to develop functional beverages and support the sustainable utilization of coffee processing by-products. This study aimed to evaluate the effect of different sugar sources on the transformation of bioactive compounds and the chemical and sensory properties of coffee ground kombucha. Kombucha was prepared using spent coffee grounds as the fermentation substrate with three sugar sources (sucrose, glucose, and fructose) and fermented for 15 days at 28 °C using a standard SCOBY culture. Microbial growth, reducing sugar, total acidity, and pH were monitored, while total phenolic content, antioxidant activity, and sensory properties were analyzed. The results showed that the sugar source significantly influenced fermentation and product characteristics. Glucose promoted the most intensive fermentation, resulting in the highest acidity (13.94 g/L) and lowest pH (2.20). In contrast, fructose produced the highest total phenolic content (1341.81 µg/mL) and antioxidant activity (83.22%). Sensory evaluation indicated that fructose-based kombucha was the most preferred due to its balanced aroma, flavor, sweetness, and acidity. Overall, fructose was identified as the most suitable sugar source for producing coffee ground kombucha with enhanced bioactive and sensory qualities.
This study examines the integration of ocean literacy and digital technology in vocational tourism education in Indonesia. Using a descriptive quantitative approach, the research explored students’ familiarity with digital learning tools and their understanding of marine concepts. While many students indicated the use of mobile applications and online platforms for learning, their exposure to ocean environments was limited, particularly for those living in inland areas. This creates challenges for marine education because direct experience is often essential for building conceptual understanding. However, technology-based learning may serve as an alternative because it enables virtual exposure to coastal systems. The Technology Acceptance Model was applied to examine how students respond to educational technologies. Findings are discussed in relation to the Sustainable Development Goals, particularly in areas concerning education, environment, and tourism. Vocational tourism education is considered in this context because it connects career preparation with sustainable practices, including the need to link tourism activities with marine awareness through accessible and adaptable learning methods.
