We update the capabilities of the open-knowledge software instrument Modules for Experiments in Stellar Astrophysics (MESA). RSP is a new functionality in MESAstar that models the nonlinear radial stellar pulsations that characterize RR Lyrae, Cepheids, and other classes of variable stars. We significantly enhance numerical energy conservation capabilities, including during mass changes. For example, this enables calculations through the He flash that conserve energy to better than 0.001%. To improve the modeling of rotating stars in MESA, we introduce a new approach to modifying the pressure and temperature equations of stellar structure, as well as a formulation of the projection effects of gravity darkening. A new scheme for tracking convective boundaries yields reliable values of the convective core mass and allows the natural emergence of adiabatic semiconvection regions during both core hydrogen- and helium-burning phases. We quantify the parallel performance of MESA on current-generation multicore architectures and demonstrate improvements in the computational efficiency of radiative levitation. We report updates to the equation of state and nuclear reaction physics modules. We briefly discuss the current treatment of fallback in core-collapse supernova models and the thermodynamic evolution of supernova explosions. We close by discussing the new MESA Testhub software infrastructure to enhance source code development.
Energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating suitable phase change materials (PCMs) within these surfaces to capture solar energy directly and increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer to the desired temperature for a longer period of time. This paper summarizes the investigation and analysis of thermal energy storage systems incorporating PCMs for use in building applications. Researches on thermal storage in which the PCM is encapsulated in concrete, gypsum wallboard, ceiling and floor have been ongoing for some time and are discussed. The problems associated with the application of PCMs with regard to the selection of materials and the methods used to contain them are also discussed.
This paper evaluates a series of programs run by a company called OPOWER to send Home Energy Report letters to residential utility customers comparing their electricity use to that of their neighbors. Using data from randomized natural field experiments at 600,000 treatment and control households across the United States, I estimate that the average program reduces energy consumption by 2.0%. The program provides additional evidence that non-price interventions can substantially and cost effectively change consumer behavior: the effect is equivalent to that of a short-run electricity price increase of 11 to 20%, and the cost effectiveness compares favorably to that of traditional energy conservation programs. Perhaps because the treatment included descriptive social norms, effects are heterogeneous: households in the highest decile of pre-treatment consumption decrease usage by 6.3%, while consumption by the lowest decile decreases by only 0.3%. A regression discontinuity design shows that different categories of “injunctive norms” played an insignificant role in encouraging relatively low users not to increase usage.
Abstract Whether the emission trading scheme (ETS) can achieve energy conservation and emission reduction in developing countries is crucial for these countries to achieve sustainable economic and environmental development. This study investigates the energy conservation and emission reduction effects of China's carbon dioxide (CO2) ETS pilot policy implemented in 2011. Based on panel data of the two-digit industry at province level from 2005 to 2015, we adopt the difference-in-differences (DID) model to examine the effects of the CO2 ETS on energy conservation and emission reduction. The results show that the CO2 ETS decreases the energy consumption of the regulated industries in pilot areas by 22.8% and the CO2 emissions by 15.5% compared to those in nonpilot areas. Further analysis indicates that the policy effects are mainly driven by improving technical efficiency and adjusting industrial structure. In addition, we find that the CO2 ETS performs better in areas with high levels of environmental enforcement and marketization. Overall, our findings suggest that the CO2 ETS has achieved energy conservation and emission reduction effects in developing countries.
Abstract In recent years, smart cities have emerged with energy conservation systems for managing energy in cities as well as buildings. Although many studies on energy conservation systems of smart homes have already been conducted, energy management at the city level is still a challenge due to the various building types and complex infrastructure. Therefore, this paper investigated the research themes on smart homes and cities through a quantitative review and identified barriers to the progression of smart homes to sustainable smart cities through a qualitative review. Based on the results of the holistic framework of each domain (smart home and city) and the techno-functional barriers, this study suggests that the following innovative solutions be suitably applied to advanced energy conservation systems in sustainable smart cities: (i) construction of infrastructure for advanced energy conservation systems, and (ii) adoption of a new strategy for energy trading in distributed energy systems. Especially, to reflect consumer behavior and energy in sustainable smart cities, the following responses to future research challenges according to the “bottom-up approach (smart home level to smart city level)” are proposed: (i) development of real-time energy monitoring, diagnostics and controlling technologies; (ii) application of intelligent energy management technologies; and (iii) implementation of integrated energy network technologies at the city level. This paper is expected to play a leading role as a knowledge-based systematic guide for future research on the implementation of energy conservation systems in sustainable smart cities.
Abstract With the implementation of a series of policies related to the energy conservation and environmental protection (ECEP) industry, green finance has become a crucial approach to provide credits for the ECEP industry. Using data on Chinese-listed ECEP firms from 2010 to 2019, this work quantitatively identifies the financing efficiency of these firms and its determinants. The main results show that banks are still dominant in the Chinese financial market for providing credits, and firms listed on the second board show higher financing efficiency. The financing efficiency of firms located in the central and western regions improves significantly, especially after 2016, reflecting the interaction effect of green finance policies and economic policies supporting underdeveloped regions. Both country-level factors (e.g., formal institutions and financial supervision) and firm-level factors (e.g., firm size and debt ratio) have an impact on financing efficiency. These findings have important implications for policymakers who are carefully contemplating green finance policies to support ECEP firms through an effective financial market mechanism, which eventually helps to realize the transition of the energy sector.
Abstract Implementing thermal insulation on the building has been acknowledged as a highly effective way to achieve cost-effective energy conservation. For implementing thermal insulation, a key problem is the proper selection of wall insulation in terms of material types and optimum thicknesses because it is challenged to balance energy-saving effects and economic benefits. To address this problem, we investigated the new aerogel super-insulation material for building-energy-conservation application in this paper. Specifically, we took a typical office building of humid subtropical climate as a model, established a whole-life-cycle-assessment model to exploit the optimum economic thickness, and further evaluated the energy-saving rate, economic benefits, the greenhouse-gas emissions, etc. Besides, we compared the super-insulated aerogel with four commonly-used insulation materials, i.e., expanded polystyrene, extruded polystyrene, foamed polyurethane, and glass fibers. Experimental results showed that aerogel had the minimum optimum thickness of 3.7 mm. When aerogel was implemented with the optimum thickness, the annual cooling and the heating load for the hollow shale brick building were reduced by 7.5% and 18.2%, respectively. Additionally, compared with the other materials, aerogel achieved a faster reduction for greenhouse-gas emissions as the thickness increased. The aerogel insulation could lead to lower carbon emissions, e.g., CO2 (8.169 kg/(m2yr)) emissions with LPG fuel, and thus would be more preferable for environmental protection. The building energy simulations employed can be further strengthened in the future by considering the effect of urban microclimates and actual internal heat gains in offices.
Improving the thermal efficiency of internal combustion engines plays a crucial role in reducing fuel consumption and engine emissions. Studies have shown that the friction loss caused by the piston ring–cylinder liner pair accounts for approximately 30–40% of the engine’s total mechanical friction. The key to improving mechanical and thermal efficiency lies in reducing frictional losses through advanced solutions. However, as engine intensification increases, the growing thermal and mechanical loads lead to out-of-round deformation of the cylinder liner. This deformation reduces the sealing conformity of the piston rings, leading to increased blow-by and elevated particulate matter (PM) emissions. To address this, a dynamic–static deformation testing system for cylinder liners, combined with a multi-physics simulation for data validation, has been developed to achieve energy conservation and emission reduction in engines. Based on established strain gauge and eddy current displacement sensors, this study developed a dynamic deformation testing system, modified for a specific type of diesel engine, and analyzed the cylinder liner deformation under fired conditions. Test results show that under engine speeds ranging from 700 rpm to 1100 rpm, the overall radial out-of-roundness of the cylinder liner increased, with a maximum deformation of 49.2 μm. The second-order component of out-of-roundness also increases with speed, showing a maximum rise of 28.9 μm, while the third-order and fourth-order components exhibit relatively minor changes. These findings suggest that the overall radial deformation under fired conditions is mainly dominated by second-order out-of-roundness, with third-order and fourth-order components contributing marginally.
Cassandra Upton, Gerhard Prinsloo, Paul Anton Steenkamp
et al.
IntroductionSea cucumbers are ecologically and economically significant marine invertebrates, yet the metabolic diversity and bioactive potential of noncommercialized, endemic species remains poorly understood.MethodsThis study presents the first intra-species metabolomic analysis of Pseudocnella sykion, a species endemic to the Eastern coast of Southern Africa, using untargeted 1HNMR metabolomics and full-scan UPLC-QTOF-HR-MS.ResultsThe analysis revealed a diverse array of metabolites associated with protein synthesis, tissue growth, osmoregulation, and energy utilization, with distinct tissue-specific patterns across the body wall, gonad, and gut/mesentery. The gut/mesentery tissue showed higher levels of amino acids and energy-related compounds. UPLCQTOF-HR-MS tentatively identified several metabolites, including triterpene glycosides and rosmarinic acid, a phenolic compound typically associated with plants. Online resources, including the Dictionary of Marine Natural Products, contained no previously recorded compounds for P. sykion.DiscussionThese findings underscore the untapped potential of P. sykion as a source of novel metabolites and demonstrate the utility of untargeted metabolomics in generating baseline profiles for underexplored marine species. The results offer a foundation for future research into bioactivity, environmental monitoring, and cultivation strategies. While this study provides critical baseline data, challenges in metabolite identification and extraction underscore the need for further targeted analyses. Overall, this research enhances our understanding of the metabolic dynamics of sea cucumbers and advocates for continued exploration of lesser-known species to support conservation, bioprospecting, and sustainable aquaculture. It represents a pioneering effort in metabolomic profiling of Southern African sea cucumber species and lays the groundwork for future investigations into their metabolic pathways and potential bioactivities.
Science, General. Including nature conservation, geographical distribution
seyed mohammad Mousavi, Mohammad Gheibi, Stanisław Wacławek
et al.
The rise in greenhouse gas emissions in cities and the excessive consumption of fossil energy resources has made the development of green spaces, such as green roofs, an increasingly important focus in urban areas. This study proposes a novel smart energy-comfort system for green roofs in housing estates that utilises integrated machine learning (ML), DesignBuilder (DB) software and Taguchi design computations for optimising green roof design and operation in buildings. The optimisation process maximises energy conservation and thermal comfort of the green roof buildings for effective parameters of green roofs including Leaf Area Index (P1), leaf reflectivity (P2), leaf emissivity (P3), and stomatal resistance (P4). The optimal solutions can result in a 12.8% increase in comfort hours and a 14% reduction in energy consumption compared to the base case. The ML analysis revealed that the adaptive network-based fuzzy inference system is the most appropriate method for predicting Energy-Comfort functions based on effective parameters, with a correlation coefficient greater than 97%. This novel smart framework for the optimal design of green roofs in buildings offers an innovative approach to achieving energy conservation and thermal comfort in urban areas.
Abstract Individuals usually present highly stable differences in household energy conservation intentions. Personality traits are a possible explanation for such differences. However, the mechanism through which personality traits affect household energy conservation intentions is still unclear. This research aims to explore the roles of personality traits in household energy conservation intentions by connecting the Big Five personality traits with household energy conservation intention through the Theory of Planned Behavior (TPB). The study employs data from a survey in Xi'an, China, with a valid sample size of 279 households. The analysis results indicate that, except for Extraversion, the other four personality traits affect household energy conservation intentions through different mechanisms. Agreeableness and Openness show positive correlations with all three TPB predictors. Conscientiousness also presents a positive correlation with perceived behavioral control, while Neuroticism only presents a negative relationship with attitude. This study combines personality traits with TPB to investigate household energy conservation intentions. The results provide a shred of empirical evidence on the relationships between personality traits and pro-environmental behaviors in northwest China. The findings of this study would contribute to eco-friendly policy-making for sustainable community development.
La crisis ambiental por el cambio climático ha obligado a muchos Estados a dirigir esfuerzos hacia la transición medioambiental para reducir la probabilidad de ocurrencia de una situación con un impacto negativo sobre su población o medioambiente. El Perú no es la excepción. En tal sentido, surge la necesidad de identificar y categorizar sus distritos según un determinado riesgo socioambiental. Ante tal reto, se construyó e implementó una metodología cuantitativa multietápica, la cual hizo uso tanto del aprendizaje automatizado (supervisado y no supervisado) como de la econometría espacial. Los resultados de la metodología, visualizados a través de índices de riesgo emergentes, evidenciaron la existencia de 165 distritos considerados zonas con riesgo socioambiental (ZRS), ubicados en su mayoría en la franja costera. Finalmente, se concluye que el patrón y replicabilidad del modelo de desarrollo urbanístico en el Perú actualmente no es coherente con los esfuerzos de conservación y preservación del medioambiente.
Ting-Ting Duan, Sahanaa Büriechin, Hai-Ling Lao
et al.
In this minireview article, we examine the inconsistent results of thermal parameters derived from various models in high-energy collisions. Through a comprehensive literature review and based on the average transverse momentum or the root-mean-square transverse momentum, we propose model-independent parameters to address these inconsistencies. The relevant parameters include: the initial temperature, the effective temperature, the kinetic freeze-out temperature, and the average transverse velocity. Our findings indicate that these four parameters are larger in central collisions, within central rapidity regions, at higher energies, and in larger collision systems. As collision energy increases, excitation functions for all four parameters rise rapidly (slowly) within ranges below (above) approximately 7.7 GeV. At higher energies (>39) GeV, fluctuations occur in trends for these excitation functions, with only slight changes observed in their growth rates. Additionally, this work reveals a mass-dependent multi-temperature scenario pertaining to both initial states and kinetic freeze-out processes.
After reviewing the sound speeds in various forms and conditions of matter, we investigate the sound speed of hadronic matter that has decoupled from the hot and dense system formed during high-energy collisions. We comprehensively consider factors such as energy loss of the incident beam, rapidity shift of leading nucleons, and the Landau hydrodynamic model for hadron production. The sound speed is related to the width or standard deviation of the Gaussian rapidity distribution of hadrons. The extracted square speed of sound lies within a range from 0 to 1/3 in most cases. For scenarios exceeding this limit, we also provide an explanation.
Abstract People spend about 90% of their time indoors. Fresh air supply in buildings can improve indoor air qualities and become a concern due to sick building syndrome (SBS) and the outbreak of the SARS. The most common method of cooling or heating fresh air is to use air handling units. However, there is often a large enthalpy difference between outdoor fresh air and indoor air, which leads to a large amount of energy consumption by fresh air systems. In order to achieve the goal of zero energy building, passive waste heat recovery equipment, active waste heat recovery systems and earth-air heat exchangers have been developed to handle fresh air. This paper presents a comprehensive review on energy conservation technologies for fresh air supply, including theoretical, experimental and simulation works. The advantages and disadvantages, economy and climate adaptability of different energy conservation technologies for fresh air supply in buildings are analyzed and discussed. And then challenges and future research directions of fresh air supply technologies are discussed. This paper aims to pave a way for future research and development in fresh air supply technologies for Zero energy buildings.
Anaerobic bacteria ferment carbohydrates and amino acids to obtain energy for growth. Due to the absence of oxygen and other inorganic electron acceptors, the substrate of a fermentation has to serve as electron donor as well as acceptor, which results in low free energies as compared to that of aerobic oxidations. Until about 10 years ago, anaerobes were thought to exclusively use substrate level phosphorylation (SLP), by which only part of the available energy could be conserved. Therefore, anaerobes were regarded as unproductive and inefficient energy conservers. The discovery of electrochemical Na+ gradients generated by biotin-dependent decarboxylations or by reduction of NAD+ with ferredoxin changed this view. Reduced ferredoxin is provided by oxidative decarboxylation of 2-oxoacids and the recently discovered flavin based electron bifurcation (FBEB). In this review, the two different fermentation pathways of glutamate to ammonia, CO2, acetate, butyrate and H2 via 3-methylaspartate or via 2-hydroxyglutarate by members of the Firmicutes are discussed as prototypical examples in which all processes characteristic for fermentations occur. Though the fermentations proceed on two entirely different pathways, the maximum theoretical amount of ATP is conserved in each pathway. The occurrence of the 3-methylaspartate pathway in clostridia from soil and the 2-hydroxyglutarate pathway in the human microbiome of the large intestine is traced back to the oxygen-sensitivity of the radical enzymes. The coenzyme B12-dependent glutamate mutase in the 3-methylaspartate pathway tolerates oxygen, whereas 2-hydroxyglutaryl-CoA dehydratase is extremely oxygen-sensitive and can only survive in the gut, where the combustion of butyrate produced by the microbiome consumes the oxygen and provides a strict anaerobic environment. Examples of coenzyme B12-dependent eliminases are given, which in the gut are replaced by simpler extremely oxygen sensitive glycyl radical enzymes.