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QBlade-based aerodynamic investigation of NREL S823 and S815 airfoils under different Reynolds regimes
No full textThe efficiency of lift-based wind turbines mainly depends on the selection of airfoils and its performance under various operating flow conditions. So, it is very important to study the airfoil performance, nothing but aerodynamic behaviour, under different flow conditions. Such kind of study is attempted in this work. For that, two airfoils viz., NREL S823 and NREL S815 were selected and analysed using the open source QBlade software, which built on XFOIL. The simulation is carried out under various Reynolds numbers (Re) fluctuating between 0.13×105 to 0.26×105. From the results, the various aerodynamic characteristics such as lift coefficient (CL), Sliding ratio also called as Lift to Drag ratio (CL/CD), along with Coefficient of Pressure (Cp) were analysed over a range of AoA (angle of attack) i.e., - 5° to 20°. The simulation results revealed that, the NREL S823 airfoil demonstrates greater CL value at lower Re numbers, making it appropriate choice for small-scale wind turbines, while S815 displays smoother stall characteristics and higher CL/CD values at higher Re, which is more required for medium scale wind turbines. Moreover, distribution in CP is a significant factor in deciding which airfoil to apply to the wind turbine designs, whether the design focus is upon the greatest possible operating stability or the ratio of lift to drag performance at variable aerodynamic load. The presented QBlade-based study helps to identify the impact of the Reynolds number on aerodynamic behaviour and offers comparative information on the suitability of the airfoils S823 and S815 in various applications in wind turbines
Synergistic Optimization of Water Resources Allocation Based on Energy Transition
No full textAgainst the backdrop of global climate governance and the low-carbon energy transition, the cumulative impacts of traditional energy development on regional water resource systems are becoming increasingly prominent. Water resources have emerged as a critical boundary condition constraining energy development. This study reveals significant pressures on both the supply and demand sides of water resources during the energy transition. On the supply side, the development of traditional energy sources has been subject to three rigid constraints: the disruption of surface water network connectivity, the reduction policies for over-exploitation of groundwater, and the efficient utilization of unconventional water sources. On the demand side, the energy transition drives structural changes, where industrial restructuring enhances water use efficiency, while emerging energy industries introduce differentiated, high-quality water demands. These factors collectively steer water resources allocation towards structural optimization and precise adaptation. In response, this research constructs a synergistic optimization function targeting “maximized economic benefits, optimized water efficiency, and enhanced system equilibrium.” It proposes a synergistic pathway encompassing model quantification, comprehensive evaluation, and policy generation. Case study results demonstrate that this optimization pathway can improve regional energy system's water use efficiency by approximately 15%-20%, while enhancing the spatial equilibrium of water resources allocation by over 10%, providing a quantitative tool for aligning energy transition with water resource availability. Furthermore, a water resources collaborative governance mechanism is proposed, involving cross-departmental coordinated decision-making, market-based regulation, and monitoring and evaluation. This study offers theoretical support and decision-making references for advancing the energy system towards a greener, safer, and more sustainable future
Empirical Study on BIM-Driven Full-Lifecycle Low-Carbon Management in Landscape Architecture Projects
No full textTo clarify the application value and implementation path of BIM (Building Information Modeling) in landscape architecture, this study takes a university campus square as the case, combining questionnaire surveys (101 valid samples), case participation analysis, and comparative research to explore BIM’s full- lifecycle application effects and compare it with traditional 2D CAD technology. Results show that landscape professionals have high recognition of BIM (mean 3.73) but low application level (mean 2.92). Leveraging core features of visualization and coordination, BIM optimizes site ecological analysis in planning, reduces resource waste caused by design conflicts, enhances multi-stakeholder collaboration in low-carbon design, and achieves precise control of carbon emissions and cost-schedule during construction. This study confirms that BIM is an inevitable choice for the green transformation of the landscape architecture industry under the “dual carbon” goals, providing scientific support for full-lifecycle low- carbon project management. Compared with 2D CAD, BIM outperforms in intuitiveness, structural integrity, information comprehensiveness, query efficiency, and engineering quantity calculation. This study confirms that BIM is an inevitable choice for the transformation and upgrading of the landscape architecture industry, providing scientific support for full-lifecycle project management.
The role of ultraviolet light in air cleaning: A mini review on microbial and pollution control
No full textSince the onset of the COVID-19 pandemic, the importance of indoor air quality (IAQ) has gained significant attention, as SARS-CoV-2 and other infectious agents can spread through inhalable aerosols. Air-cleaning devices that combine filtration with pollutant-targeted treatments offer a promising approach to improving IAQ. Yet, relatively few filtration systems incorporating UV (Ultraviolet) technology have undergone rigorous performance testing, and publicly available data on their effectiveness, including comparable UV doses, remain limited. In this study, we enhanced an existing particulate matter (PM) filtration prototype by integrating germicidal UV-C light to expand its disinfection capability. This mini review explores the application of ultraviolet (UV) light as amethod to improve indoor air quality by reducing airborne bacteria, viruses, and pollutants. UV disinfection is shown to be effective in inactivating microorganisms while also contributing to the reduction of particulate pollution, thereby supporting healthier indoor environments. Importantly, the study emphasizes that UV technologies achieve the greatest impact when integrated with other engineering controls, such as filtration and ventilation, offering a comprehensive strategy for protecting human health
Value engineering research on construction materials cost efficiency for electronic storage warehouse project
No full textBudget management becomes especially difficult for electronic warehouses' materials because of the overspending that occurs from the use of substandard structural materials. Reinforced concrete and Wide Flange (WF) steel sections are the two materials that most people consider for the construction of warehouses. A case study focusing on an electronic warehouse model in Depok. The modelling used Building Information Modelling tools, and only focused on beams and columns which are crucial structural components. This study utilizes a systematic Value Engineering (VE) approach, focusing on integrating functionality and costs to preserve construction integrity while optimizing project value in these two aspects. The study concludes reinforced concrete for the main columns and beams not only supports construction with 25% less material than steel WF options, but also provided the project a cost saving of 21,106,579.93 IDR. This is vital for large projects where budget restrictions are very strict. Furthermore, the use of reinforced concrete is economical and, with lower weight, mobile cranes and other heavy construction machines become unnecessary. This not only reduces the cost of the project, but also simplifies construction and accelerates the saving of money
Investigating the hidden curriculum’s influence on pro-environmental behavior in primary schools in Jakarta, Indonesia
No full textSchools play an essential role in developing students' environmental responsibility through both formal instruction and informal learning embedded in everyday practices. Recent discussions highlight the significance of the hidden curriculum, which includes the school's social environment, values, and interactions, in shaping pro-environmental behavior (PEB). This study investigates the association hidden curriculum components on students' PEB and examines whether gender and school type relate to variations in student behavior. A quantitative design was used, involving 217 students and 44 teachers from four elementary schools in Jakarta. The results indicate that the hidden curriculum significantly predicts PEB (R2 = .331, p < .001). Students in public schools scored higher in PEB than those in private schools, and female students showed stronger pro-environmental behavior than male students. These findings align with previous studies on gendered behavior and school culture. Although none of the three hidden curriculum components emerged as individually significant, social interaction showed the strongest coefficient among the predictors. This research supports the role of value-based education in promoting both SDG 4 (Quality Education) and SDG 13 (Climate Action), emphasizing the need to strengthen everyday environmental practices in primary schools
Assessing tracker availability in 2 GW solar power plants
No full textSingle-axis trackers are key components to optimize utility-scale solar energy generation. As the overall electricity production share of PV is globally increasing at a significant pace, profitability margins narrowed and the industry is becoming more competitive. Ensuring high availability of all devices in a photovoltaic (PV) power plant is crucial for healthy asset life. Historically, specific key performance indicators (KPI) for single-axis trackers have been overlooked by both research and industry. This work proposes a KPI for trackers, with two alternative methods. Over 2GWp of PV power plants have been analyzed, mostly located in temperate climate zones. The median of results range from 66% to 88% availability, depending on data filtering considerations. These results are substantial, and alarming. Industry claims sometimes even as high as 99% availability, while the assessment of more than 2 GWp PV power plants tells us a different story. In addition, this work highlights and discusses multiple issues regarding tracker data quality, especially related to angle datasets, and identifies missing data as one of the main systematic issues when dealing with single-axis tracker data
Impinging jet duct diffuser ventilation effectiveness benchmarking with mixing ventilation in a mock-up classroom
No full textThe benefits of effective classroom ventilation for health and learning outcomes are well known. However, studies continue to report inadequate air quality, insufficient air change rates, and too high air velocities. This study investigated classroom air distribution solutions in the ventilation air distribution laboratory at Tallinn University of Technology. Nozzle diffusers and duct diffusers mounted in the ceiling were compared with two impinging duct diffuser configurations installed on the shorter sides or the single longer wall of the mock-up classroom. Draught risk was assessed using air velocity probes in a mock-up classroom setup with a dedicated room-based air handling unit and thermal dummies simulating student heat loads. Contaminant removal effectiveness was evaluated using the continuous tracer gas injection method with multiple point source locations. Results showed that close to fully mixed ventilation effectiveness was achieved both with ceiling and perimeter impinging ventilation. Measured contaminant removal effectiveness varied across 0.85 to 1.16. The 10° nozzle duct diffuser configuration demonstrated the best performance of impinging ventilation in terms of ventilation effectiveness and draught control. When positioned to the longer side of the room with the extract close to the opposite wall, this configuration further improved overall performance, though it resulted in elevated air velocities at floor level. To avoid draught, the airflow rate needed to be reduced with these perimeter nozzle duct diffusers to 3.3 L/s m2 while the ceiling nozzle and ceiling duct diffusers were capable of 4.5 L/s m2 without draught. The results demonstrate the potential and also a challenge of floor level air velocity of perimeter impinging jet ventilation worth to be further studied for practical applications
Hierarchical graph-based method for static daylight prediction of 3D irregular office buildings
No full textEfficient daylight prediction in geometrically complex office buildings remains challenging due to computational constraints and oversimplified representations in existing methods. While data-driven approaches accelerate simulations tenfold, they often neglect architectural form sensitivity and window placement effects. This study overcomes these limitations through a novel graph-based framework integrating physical daylight principles with machine learning. We develop a hierarchical semantic grammar for building topology representation and introduce dihedral angle-based encoding to capture critical glazing-to-space geometric relationships as graph edge features. An adaptive graph convolutional network subsequently aggregates multi-scale neighbor information for light transport modeling. Validated against Radiance benchmarks, the framework demonstrates an 80% accuracy improvement in daylight factor prediction while achieving 30% greater computational efficiency than comparable CNN methods. This approach effectively resolves the persistent accuracy-speed trade-off in performance simulation, enabling robust daylight optimization for sustainable design