bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental investigation into the effects of endplate designs for a Savonius turbine
Authors: Wong K H , Foo J S Y , Chong W T , Mat S , Ng J H 
Published: July 2024

Abstract
Wind energy is experiencing a trend of exponential growth in both literature and industrial employment, emphasizing its current pivotal role in achieving carbon neutrality by replacing fossil fuels. Vertical axis wind turbines (VAWTs) particularly Savonius rotors operate at a lower tip-speed-ratio (TSR) range compared to horizontal axis wind turbines (HAWTs). The Savonius rotor has good starting characteristics, making it suitable to be placed in urban areas with lower wind speeds. Due to its low efficiency, studies on augmentation and optimization have been conducted to improve its blade and deflector designs. Extensive research has established a common consensus that the use of endplates significantly improves the aerodynamic performance of the Savonius rotor. However, limited research has been undertaken to explore the endplate design further. In this study, wind tunnel tests were conducted on different endplate ratios, to investigate the effects of endplate design on the aerodynamic performance of a conventional Savonius turbine. Three different Savonius rotor with no endplate, semi-circular endplate and circular endplate were designed and manufactured. Experiments were conducted in an open-type suction wind tunnel at a constant measured wind velocity of 5.89 m/s. The turbine’s performance for different endplate ratios was evaluated across a TSR range of 0.2 to 1.0. The performance was assessed based on the maximum power generated and its self-starting ability. From the experimental results, the circular endplate ratio of 1.1 shows a significantly high coefficient of power compared to both semi-circular and without endplates. This is due to reduced spanwise spillage and enhanced airflow capture by the rotor. The endplates direct incoming air to the advancing blade and overlap region, resulting in the increased pressure difference between the concave and convex sides of both the advancing and returning blade, thereby improving the power efficiency of the turbine with 1.1D diameter endplate and semi-circular endplate by 296.6% and 6.9% compared to no endplates case.
Simulation on solidification process of molten salt-based phase change material as thermal energy storage medium for application in Stirling engine
Authors: Putra G J P , Putra N 
Published: July 2024

Abstract
Thermal energy storage technologies have been widely used to mitigate intermittency from renewable energy such as solar energy. Phase change material (PCM) is a certain material that can be used as a heat storage medium and is available in a wide range of operating temperatures. Molten salt is one of the PCMs that has the advantage of a very high operating temperature. The PCM solidification simulation based on HitecXL molten salt using COMSOL Multiphysics software will be carried out with variations in heat absorption of 1 - 5 kW/m2, assuming constant heat absorption. The results show that the PCM solidification process starts from the surface of the Stirling engine heat exchanger pipe. The part of the PCM that has been solidified will fall following the direction of gravity and cause a phenomenon such as a droplet. The flow that occurs is a natural flow caused by the buoyancy force due to changes in density due to temperature gradients in the solidification process. The time required for the PCM to completely solidify is closely related to the amount of heat absorption. The greater the heat absorption from the pipe, the faster the PCM to fully solidified.
Startup characteristics of a water loop heat pipe with dual heat sources for battery thermal management system in electric vehicle
Authors: Fathoni A M , Hendrayanto P A , Aliefiansyah M S , Putra N 
Published: July 2024

Abstract
The usage of electric vehicles has significantly reduced emissions of greenhouse gases and other pollutants. However, the high heat release generated by the electric vehicle batteries poses a challenge. To solve this problem, scientists have created a passive cooling thermal management system specifically for electric vehicle based on heat pipes, particularly loop heat pipes. A battery pack often consists of several battery modules, which results in multiple heat sources being dispersed according to their power capacity. Startup behavior of loop heat pipe has been investigated extensively in the literature. However, most of the studies use only one heat source. This paper aims to fill the research gap, particularly when the system is implemented in dual heat sources managed by only one evaporator. To achieve the research objectives, a custom loop heat pipe was constructed. This cooling system’s design is briefly described. The evaporator is made of copper, deionized water was selected as the working fluid because of its high merit number, which indicates strong performance as a heat pipe working fluid and the stainless-steel wire mesh serves as the porous wick. Battery simulator was built using aluminum material and a cartridge heater to mimic the heat produced by the battery. Two case studies were done. First, only one battery simulator was used. Second, two battery simulators were placed on both sides of the evaporator. A type-K thermocouple attached to the NI DAQ 9214 module was used to measure the temperature while the electric heat load varied between 10 W and 50 W. The study investigated the interaction between the heat load distribution and the startup behavior of the loop heat pipe. Startup behavior is crucial for the performance of the loop heat pipe. Based on the experimental results, the loop heat pipe demonstrates outstanding startup performance. It can effectively initiate operation even at a minimal heat load as low as 30 W for the first and second case study. The findings of the study indicate that the dual heat source arrangement effectively mitigates overshoot temperatures and enhances heat transfer performance by increasing the contact area.
Effect of alkali metal cations in alkaline iron battery electrodes
Authors: Loresca D E D , Paraggua J A D R 
Published: July 2024

Abstract
Rechargeable alkaline iron batteries (e.g. Ni-Fe and Fe-air) have been extensively studied recently as viable energy storage systems for renewable energy sources. However, inherent issues such as passivation of the iron and parasitic hydrogen evolution reaction (HER) on the electrode surface limit their full capability. Multiple approaches to improving iron electrode performance have been conducted, few of which focused on electrolyte composition. While alkali metal (AM) cations on the electrolyte do not directly participate in the electrochemical reactions, their intrinsic characteristics can dictate the performance of the electrode. Investigating the interface interactions and electrical double layer (EDL) structure can provide a deeper insight into the operation of iron electrodes in an alkaline solution. In this work, we investigated the effect of alkali metal cations (Li+, Na+, K+, Cs+) in the electrolyte solution in inhibiting passivation and HER on electrodeposited iron on carbon paper (Fe/CP) electrodes. The electrochemical measurements show that the iron redox and HER activities of the electrode increased with increasing cation size in the electrolyte. The non-covalent interactions between hydrated alkali metal cations and adsorbed OH species resulted to the formation of quasi-adsorbed clusters which can block active sites on the electrode surface. Furthermore, the concentration of these clusters decreases with increasing cation size which resulted to higher EDL capacitance and ECSA values of the electrode. The results of this work provide a better understanding of the surface reactions on iron electrodes and can help in developing novel techniques for suppressing passivation and parasitic HER on rechargeable alkaline iron batteries.
Energy stacking efficiency of a novel low-frequency spring-like piezoelectric energy harvester
Authors: Wong G S , Lee K Q , Eileen Lee M S , Kang H S , Wong K Y 
Published: July 2024

Abstract
This study introduces a novel approach to energy harvesting through a spring-like piezoelectric harvester, termed SPEH, specifically designed for extremely low-frequency excitations. Through the integration of PVDF films and incorporating multiple thin plastic layers, the experimental setup underwent testing across various impact amplitudes and loads. Notably, the results revealed that the height of the impact significantly influenced peak voltage generation, with a remarkable 74% surge observed between a 3-inch and a 1-inch impact under a 90g load. Conversely, the impact load exhibited a comparatively lesser influence on peak voltage. The analysis of generated RMS voltage demonstrated a consistent trend, where higher impact height and load weight correlated with increased RMS voltage, emphasizing the significance of system mass. This innovative approach seeks to harness ambient vibration energy for sustainable power generation, marking a stride in advancing low-frequency piezoelectric energy harvesting systems.
Designing an absorber for solar photovoltaic thermal systems: a heat pipe approach and comparative evaluation
Authors: Kamble A D , Das D , Kalita P 
Published: July 2024

Abstract
Renewable energy power generation is extensively promoting for the global objective of mitigating greenhouse gas emissions. Solar energy leads all renewables due to its ubiquitous nature which can be harvested by solar thermal and solar photovoltaic devices. Solar PV is used widely because of its flexibility in working with both direct and diffuse radiation. However, PV systems experience efficiency loss for every degree rise of solar cell temperature above room temperature. Solar photovoltaic-thermal (PVT) collectors are proposed for co-generation of electrical and thermal energy by utilizing excess heat generated in the PV layer. The low heat transfer rate, energy-intensive nature, and freezing of working fluid in colder regions are some problems that persist in water- and air-based PV/Ts, leading us to consider alternatives. Thus, the present study addresses the current opportunities by utilizing heat pipes as PV/T absorbers. Heat pipe PVT is a passive system which operates in phase transition facilitating a tremendous amount of heat transfer enhancement. To enhance the efficiency of PV/T systems, the integration of advanced technologies, like heat pipe thermal absorbers, becomes imperative. Incorporating cutting-edge solutions, such as heat pipe thermal absorbers, is essential to optimize the performance of PV/T systems. Hence, the current study provides insight into heat pipe design through a case study on the application of heat pipes as thermal absorbers for photovoltaic systems. The existing absorbers with fluid flow configurations like Raster, Spiral or Rectangular spiral, etc. used in PV/T are considered as reference. Copper as tube material and water as working fluid are found to be compatible with each other for the proposed heat pipe. The maximum heat input of 0.55kW is computed by the inadequacy of the mentioned existing PVTs to extract the maximum available heat from the PV surface. Additionally, an analytical approach used to define the optimum size of the system and calculation of minimum requirement of tubes. The optimized design of copper heat pipes was found to be ½ inch in diameter and at least ten heat pipes were required to transfer a computed heat flux of 466kW/m
2 per pipe to outperform the existing PV/Ts.
Solar-assisted biogas system with air-source heat pump for the energy-saving of indoor heating in north China
Authors: Sun T M , Khairuddin A S M , Soon T K , Pang L L , Wang X R , Wu J S , Zheng Z J , Novikovs A 
Published: July 2024

Abstract
To address the challenges associated with winter heating in high-latitude regions of China, solar-assisted biogas heating systems have emerged as the predominant focus of research due to their cost-effectiveness, accessibility, and environmentally friendly attributes. However, traditional solar-assisted biogas heating systems encounter issues of low efficiency and limited practicality resulting from unstable solar radiation and extreme ambient temperatures during the heating season. To improve the economy and stability of the system, this study proposed a novel operational control method for a small-scale energy station system in rural regions of North China, named Solar-Biomass-Air Source Heat Pump Hybrid Heating System (SBHP-HHS). The integration of solar energy, biogas energy, and air-source heat pump (ASHP) systems in this proposed work has shown to create effective complementarity and enhances the production efficiency of the existing system. Test and simulation studies have been carried out for this system. The layout of buildings and equipment within a university campus in Beijing is reconfigured and redesigned, incorporating an ASHP into the existing heat source configuration. To begin with, a mathematical model is established for the complementary heating system that incorporates solar energy, a biogas digester, and an ASHP. Subsequently, a dynamic simulation model is developed using the TRNSYS platform, and a corresponding operational control strategy for the multi-energy complementary heating system is proposed. Dynamic simulation and analysis of the newly implemented system are performed using the TRNSYS platform, focusing on energy flow and thermodynamic performance. Throughout the heating season, the solar-biogas integrated system achieves a remarkable assurance rate of up to 79%. Additionally, ASHP maintains a relatively high heating efficiency, coefficient of performance (COP) reaches 3.02. Finally, an economic evaluation of the multi-energy complementary system was conducted based on the annual cost method. This was compared with the clean approach of using only an ASHP unit. The results indicate that the SBHP-HHS is more economical when the anticipated useful life is 6 years or longer. The results indicate that the proposed can achieve significant energy-saving and carbon-reduction benefits in rural areas, catering to their heating needs.
A comprehensive review of hybrid wind-solar energy systems
Authors: Nair Kartik Anil , Garlapati Nagababu 
Published: July 2024

Abstract
In the face of escalating global energy demands and growing environmental concerns associated with conventional energy sources, integrating renewable energy systems has become imperative. Solar and wind have become key contributors to a cleaner and more sustainable energy future among these renewable energy sources. However, their intermittent nature, unpredictability, and infrastructural demands present significant challenges. Hybrid renewable energy systems (HRES) have emerged as a transformative solution to address these challenges. This paper conducts a comprehensive review of HRES, explicitly focusing on integrating wind and solar energy sources to address the limitations of individual systems. The review encompasses a systematic analysis, commencing with identifying optimal deployment areas for hybrid systems, considering geographic and climatic factors that maximize energy yield. Also, reviewed the in-depth exploration of the pivotal components. Additionally, the paper critically examines the crucial aspect of sizing HRES systems, shedding light on recent methodologies applied to HRES. Furthermore, the paper investigates modern advanced technologies used in HRES, particularly the latest analytical software, its methodologies, and the incorporation of effective designs for hybrid wind and solar systems. In addition to evaluating the current state of HRES technology, this article also discusses the scope of future research prospects and emerging trends in the field. It also contemplates integrating other renewable energy sources, such as biomass, with wind and solar energy according to the availability and advantages of these sources and other associated aspects. This paper will help understand the current developments in the field of HRES.
Performance research on multi-energy complementary heating systems in rural areas of China: A mini review
Authors: Pang L L , Wang C Q , Wang X R , Sun T M , Wu J S , Novikovs A 
Published: July 2024

Abstract
Winter heating in rural areas has always been an issue of great concern to the State. In China, traditional heating methods mainly use coal-fired boilers or heating stoves, however, coal burning has caused serious environmental pollution and air quality problems. In order to improve heating conditions and reduce environmental pollution, some rural areas have begun to try multi-energy complementary heating (MECH) system, which improves heating efficiency by comprehensively utilizing solar energy, biomass energy, ground source heat pump, air source heat pump (ASHP). However, due to poor economic conditions, the actual operation faces various factors and challenges. In order to solve these problems, this paper provides a systematic review of the research on MECH systems in rural areas in China in recent years. First, it summarizes the existing MECH systems, including various technologies such as solar-ASHP heating, solar-biogas heating, and ground source heat pump-solar heating, and lists their advantages and disadvantages in detail. Secondly, the effects of MECH systems in practical applications are discussed through case studies. Finally, recommendations for promoting MECH technologies are presented to facilitate the development of MECH systems in rural areas. The study contributes to the development of MECH system, which helps to improve rural heating conditions and reduce environmental pollution.
Evaluation of pyrolysis characteristics and kinetic parameters from several prospected biomass residues by thermogravimetric analysis
Authors: Pambudi S , Jongyingcharoen J S , Saechua W 
Published: July 2024

Abstract
With fossil fuel supplies dwindling and persistent environmental concerns surrounding their consumption, biomass has emerged as a highly promising renewable energy source. Understanding the characteristics of biomass pyrolysis is crucial as it provides valuable insights and guidance for designing and optimizing the pyrolysis process. In this regard, a thermogravimetric assessment was conducted to evaluate the pyrolysis characteristics and kinetic parameters of four prospective biomass sources: Yang Na wood (Dipterocarpus alatus), palmyra palm shell, cotton stalk, and spent coffee grounds with a condition temperature range of 33 °C to 700 °C and a heating rate of 10 °C·min-1 in a nitrogen atmosphere. The kinetic parameters were evaluated using the Coats and Redfern methods, employing various reaction order models. The activation energy and pre-exponential factor were determined for the active pyrolysis stage. The results revealed that the high heating values for all samples ranged from 18.20 to 23.00 MJ·kg-1. Additionally, the onset temperature fell within the range of 243 to 254 °C, while the offset temperature ranged from 365 to 452 °C for all samples. The conversion rate at the offset temperature was 0.67 for Yang Na wood, 0.62 for palmyra palm shell, 0.65 for cotton stalk, and 0.74 for spent coffee grounds. Moreover, the activation energies were measured as 46.47 kJ·mol-1 for Yang Na wood, 52.46 kJ·mol-1 for palmyra palm shell, 64.20 kJ·mol-1 for cotton stalk, and 69.01 kJ·mol-1 for spent coffee grounds. The higher activation energy corresponded to a higher pre-exponential factor. In conclusion, the pyrolysis characteristics and kinetic parameters of the four types of biomasses have been found to be favourable, indicating their potential for promotion and application as a raw material for the pyrolysis process.
Assessing the Effect of Aluminium Oxide Nanoparticle Additives on Biodiesel Combustion in Marine Diesel Engines
Authors: Mohd Noor Che Wan , Ismail Amir Azfar , Fhatihah Amirah Nur , Ahmad Mohammad Fadhli , Khasbi Jarkoni Mohammad Nor , Briggs Horizon Gitano 
Published: July 2024

Abstract
The increases in annual ship exhaust emissions have prompted the shift towards adopting alternative energy sources. Biodiesel is a suitable substitute fuel for marine engines that does not necessitate engine alterations. Biodiesel is renewable, environmentally friendly, and plant-based with biodegradable properties. The fuel is also non-toxic and oxygenated and shares similar characteristics with diesel fuel. Nonetheless, biodiesel fuel exhibits slightly reduced performance compared to diesel primarily due to its lower energy content. This study aims to evaluate the combustion attributes of a marine diesel engine employing palm biodiesel fuel incorporated with aluminium oxide (Al2O3) nanoparticle additives. A B20 biodiesel fuel was blended with 50, 100, and 150 ppm Al2O3 nano additives. The engine combustion parameters, in-cylinder pressure, heat release rate (HRR), mass fraction burned, and ignition delay were analysed and compared to the B20 fuel without additives. Adding Al2O3 nano additives to the B20 biodiesel blend improved the engine combustion characteristics. The optimal performance was recorded by the blend incorporating 150 ppm nanoparticles. The in-cylinder pressure and HRR peaks also improved by 5.41 to 15.1% and 4.69 to 16.9%, respectively, compared to the other B20 fuel blends. Furthermore, the B20 mixed with Al2O3 documented a more rapid mass fraction burned rate, resulting in a shorter ignition delay of approximately 5 CA°. In addition, the amount of oxygen in biodiesel blended with Al2O3 nano additives has improved engine combustion compared to B20 fuel. The present study demonstrated that adding Al2O3 nano additives to palm biodiesel fuel significantly enhanced engine combustion attributes, thus highlighting its potential to reduce reliance on petroleum-based fuels and provide sustainable fuel alternatives for marine diesel engines.
Trihalomethane formation potentials from the effluent of different wastewater treatment sources
Authors: Phlaengsattra K , Kanokkantapong V , Sangsanont J 
Published: July 2024

Abstract
Reused wastewater is commonly treated with disinfection to remove pathogenic microorganisms; however, this process generates disinfection byproducts (DBPs), such as trihalomethanes (THMs). This study aimed to investigate the levels of THMs and THM formation potential (THMFP) in treated wastewater originating from different sources i.e., domestic, food-processing industry and hospital. The samples from each source were collected three times between June and August 2023. Dissolved organic carbon (DOC) was evaluated from the samples prior to and after disinfection with chlorine over a period of 7 days. The results found that the concentration of DOC was highest in hospital effluent, with an average value of 5.60±0.16 mg/L followed by effluent from the food-processing industry and domestic, which had average DOC concentrations of 4.60±1.39 mg/L and 4.46±0.37 mg/L, respectively. The concentration of THMs in hospital effluent was found the highest at 6.91±0.88 µg/L followed by effluent from the domestic and food-processing industries, which exhibited amounts of 6.74±0.77 µg/L and 5.25±0.77 µg/L, respectively. In contrast, the food-processing factory had the highest concentration of THMFP at 299.39±26.54 µg/L, while the domestic and hospital effluent displayed a lower concentration of 133.64±36.86 µg/L and 51.48±9.01 µg/L, respectively.