Search

Because humans spend about one-third of their time asleep in their bedrooms and are themselves emission sources of volatile organic compounds (VOCs), it is important to specifically characterize the composition of the bedroom air that they experience during sleep. This work uses real-time indoor and outdoor measurements of volatile organic compounds (VOCs) to examine concentration enhancements in bedroom air during sleep and to calculate VOC emission rates associated with sleeping occupants. Gaseous VOCs were measured with proton-transfer reaction time-of-flight mass spectrometry during a multiweek residential monitoring campaign under normal occupancy conditions. Results indicate high emissions of nearly 100 VOCs and other species in the bedroom during sleeping periods as compared to the levels in other rooms of the same residence. Air change rates for the bedroom and, correspondingly, emission rates of sleeping-associated VOCs were determined for two bounding conditions: (1) air exchange between the bedroom and outdoors only and (2) air exchange between the bedroom and other indoor spaces only (as represented by measurements in the kitchen). VOCs from skin oil oxidation and personal care products were present, revealing that many emission pathways can be important occupant-associated emission factors affecting bedroom air composition in addition to direct emissions from building materials and furnishings.

Primary (non-motile) cilia represent structurally and functionally diverse organelles whose roles as specialized cellular antenna are central to animal cell signaling pathways, sensory physiology and development. An ever-growing number of ciliary proteins, including those found in vertebrate photoreceptors, have been uncovered and linked to human disorders termed ciliopathies. Here, we demonstrate that an evolutionarily-conserved PPEF-family serine-threonine phosphatase, not functionally linked to cilia in any organism but associated with rhabdomeric (non-ciliary) photoreceptor degeneration in the Drosophila rdgC (retinal degeneration C) mutant, is a bona fide ciliary protein in C. elegans. The nematode protein, PEF-1, depends on transition zone proteins, which make up a 'ciliary gate' in the proximal-most region of the cilium, for its compartmentalization within cilia. Animals lacking PEF-1 protein function display structural defects to several types of cilia, including potential degeneration of microtubules. They also exhibit anomalies to cilium-dependent behaviors, including impaired responses to chemical, temperature, light, and noxious CO2 stimuli. Lastly, we demonstrate that PEF-1 function depends on conserved myristoylation and palmitoylation signals. Collectively, our findings broaden the role of PPEF proteins to include cilia, and suggest that the poorly-characterized mammalian PPEF1 and PPEF2 orthologs may also have ciliary functions and thus represent ciliopathy candidates. [ABSTRACT FROM AUTHOR]

Empirical rovibrational energy levels are presented for the third most abundant, asymmetric carbon dioxide isotopologue, 16O12C18O, based on a compiled dataset of experimental rovibrational transitions collected from the literature. The 52 literature sources utilized provide 19,438 measured lines with unique assignments in the wavenumber range of 2–12,676 cm−1. The MARVEL (Measured Active Rotational‐Vibrational Energy Levels) protocol, which is built upon the theory of spectroscopic networks, validates the great majority of these transitions and outputs 8786 empirical rovibrational energy levels with an uncertainty estimation based on the experimental uncertainties of the transitions. Issues found in the literature data, such as misassignment of quantum numbers, typographical errors, and misidentifications, are fixed before including them in the final MARVEL dataset and analysis. Comparison of the empirical energy‐level data of this study with those in the line lists CDSD‐2019 and Ames‐2021 shows good overall agreement, significantly better for CDSD‐2019; some issues raised by these comparisons are discussed. [ABSTRACT FROM AUTHOR]

To reveal the catalytic function of Brønsted acid sites (BAS) and different Zn Lewis acid sites (LAS) over SSZ‐39 and Zn modified SSZ‐39 in the direct dehydrogenation of propane (DHP) and CO2‐mediated oxidative dehydrogenation (CO2‐ODHP) to propylene, a series of Zn‐modified H(Na)SSZ‐39 catalysts with various Zn loadings was prepared and conducted comparative studies between DHP and CO2‐ODHP. Detailed characterization results reveal the Zn‐loading‐dependent formation of Zn sites, primarily including Zn2+ and [Zn−O−Zn]2+, as well as their contributions in generating Lewis acid sites while neutralizing Brønsted acid sites of HSSZ‐39, namely bridged Si(OH)Al groups. In DHP, in comparison to bare HSSZ‐39, Zn/HSSZ‐39 catalysts exhibited a significantly enhanced C3H8 conversion. The presence of CO2 even further promoted C3H8 conversion in comparison to DHP. Given the above observations, we prepared Zn/NaSSZ‐39, in which the incorporation of Na further enriches the Lewis acid sites while neutralizing Brønsted acid sites of zeolite. Zn/NaSSZ‐39 even outperforms Zn/HSSZ‐39 catalysts with almost doubled C3H6 yield for CO2‐ODHP. The BAS has a poor CO2‐ODHP performance but can enhance the CO2 conversion towards CO significantly, while the Zn LAS is favorable for the CO2‐ODHP reaction, and plausible reaction paths of CO2‐ODHP on active sites are proposed. [ABSTRACT FROM AUTHOR]

A heterogeneous zirconium catalyst was grafted on a ceria‐coated silica support, denoted as Zr(OEt)x/CeO2/SiO2. It exhibited higher catalytic activity compared to its homogeneous counterpart, Zr(OEt)4, in the conversion of carbon dioxide to diethyl carbonate using tetraethyl orthosilicate as a regenerable agent in the absence of any dehydrating agents under non‐protic conditions. We found that the ceria‐coated silica (CeO2/SiO2) support not only improved the catalytic activity of Zr(OEt)4 but also inhibited catalyst deactivation during catalyst recycling tests. Furthermore, we analyzed the surface of the Zr(OEt)x/CeO2/SiO2 catalysts by FE‐SEM and EDX. [ABSTRACT FROM AUTHOR]

We propose a new reaction device for the microdiffusion analysis of CO2 in fluid samples from volcanic areas to improve the conventional analysis procedure, which requires a fixative and good handling skills. To accomplish this, a small resin reaction cell for the sample solution and acid (initiator for CO2 liberation) was devised and placed in a commercially available air-tight glass container with a Petri dish to form a microdiffusion analysis unit. The analysis was based on the principles of the conventional manual titration method that uses Ba(OH)2 as the CO2 absorbent. Using the new device, 99.5% recovery, with a relative standard deviation of 4.5% (n = 8), was achieved in a test analysis for 0.03 mmol of CO2 liberated from a Na2CO3 solution as a simulated sample. The analytical performance of the new device was almost comparable to that of conventional units under the experimental conditions of this study. Applying this new device for analyzing fluid samples from volcanic areas will contribute to enhancing the performance by reducing the possibility of CO2 contamination and by simplifying the process by eliminating the need for preparatory cleaning for fixative application. [ABSTRACT FROM AUTHOR]

Biogas is one of the renewable energy sources that may be used as an alternative. It can reduce negative environmental effects by producing electricity from agricultural waste and industrial effluents. This study intends to construct a lab-scale version of the VMMI instrument, which monitors the methane quality inside and outside the laboratory. In addition, this study aims to investigate the biogas upgradation by CO2 capture at atmospheric conditions utilizing three different alkaline absorbents (NaOH, Na2CO3, KOH) in the volumetric meter. To assess the efficiency of these alkaline solutions, an artificial biogas composition with a varied ratio of CO2 from 1 to 95% was prepared using natural gas as a methane source and CO2-filled cylinder. The biogas composition was analyzed on a gas chromatograph before and after CO2 absorption in an alkaline solution. In this study, potassium hydroxide had the maximum CO2 removal, 98%, compared to NaOH and Na2CO3. To further assess the effect of an acidic solvent, 1 M HCl acid was used, but it had a very low CO2 absorbing efficiency of 1.8%. Hence, major findings can help better understand proper alkaline solvent selection that contributes to high CO2 capture efficiency, easy use, and low cost. [ABSTRACT FROM AUTHOR]

Our industry today is predominantly based on linear value chains. Raw materials are extracted from primary sources, processed into products, used, and disposed of at the end of their life cycle. This linear economy causes a wide range of negative environmental impacts owing to the resulting greenhouse gas emissions and pollution of marine and terrestrial ecosystems. Closed carbon cycles and climate-neutral energy production are essential for the production not only of fuels but also of all chemicals, including plastics and fertilizers, to counteract climate change and further damage to the environment. In this regard, this article discusses the importance of heterogeneous catalysts for selected technologies associated with this transformation of the resource base and energy supply. It discusses the technological framework conditions of a net CO2-neutral industry, with a focus on electrocatalytic water-splitting for hydrogen production, as well as the catalytic challenges of production of chemicals for the whole value chain using biomass, CO2 and plastic waste as raw materials. This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'. [ABSTRACT FROM AUTHOR]

The current research investigates the impact of financial development, digitalization, green trade, manufacturing, and national income on carbon dioxide (CO2) emissions of six Mediterranean countries (MEDIT-6). The study uses a nonlinear panel quantile regression model with panel data of MEDIT-6 countries from 1994 to 2022. The study asserts that higher financial development will reduce CO2 emissions for MEDIT-6 countries, as it provides more financing options to invest in green energy and potentially curb excessive energy consumption which in turn reduces CO2 emissions. The study also provides evidence that digitalization in MEDIT-6 countries has led to dematerialization, thereby reducing CO2 emissions. Digitalization makes trade and commerce platforms more efficient by facilitating the smooth flow of information and enhancing the efficiency of production processes. The positive relationship between manufacturing and national income and CO2 emissions exhibits a U-shaped pattern, which supports the existence of Environmental Kuznets Curve (EKC) hypothesis. The study shows how the MEDIT-6 countries have been successful in promoting financial development and digitalization, which helps reduce their CO2 emissions. However, it also raises concerns for policymakers as promoting developmental activities such as manufacturing is inevitable, but it comes with environmental challenges such as higher CO2 emissions. The current study contributes to the reservoir of existing literature by providing fresh evidence from the Mediterranean region on the impact of financial development and digitalization on CO2 emissions. Highlights: • Policymakers have difficulties since encouraging developmental activities is unavoidable, but it leads to increased CO2 emissions. • Study examines the asymmetric impact of digitization and financial development on CO2 emissions of MEDIT-6 countries. • The MEDIT-6 countries have been effective in advancing digitization and financial development, which lowers their carbon footprints. [ABSTRACT FROM AUTHOR]

Injecting carbon dioxide (CO2) into subsea water zones where the in situ temperatures are below the hydrate‐forming temperature of CO2 has been recently proposed to lock CO2 inside the water zones in solid hydrate form. It is a common concern that CO2 may form hydrates during the injection period that will reduce well injectivity. CO2 injection into sandstone cores under simulated subsea temperatures of 2°C and 3°C was investigated in this study. Experimental result shows that, at 2°C temperature, flowing CO2 at Darcy velocity 0.033 cm/s begins to form hydrate in the sandstone core at about 3.06 MPa (450 psi), which is much higher than the minimum required pressure of 1.5 MPa (220 psi) for CO2 to form hydrate in static condition. The pressure ratio is 450/220 = 2.05. At 3°C temperature, flowing CO2 at Darcy velocity 0.045 cm/s begins to form hydrate in sandstone core at about 3.67 MPa (540 psi), which is much higher than the minimum required pressure of 1.87 MPa (275 psi) for CO2 to form hydrate in static conditions. The pressure ratio is 540/275 = 1.96. The reason why the required minimum pressure for CO2 to form hydrates in dynamic conditions is about double the required hydrate‐forming pressure in static conditions is not fully understood. It is speculated that the shear rate effect of flowing fluids should slow down the growth of hydrate crystals or break down hydrate films, resulting in delayed formation of bulk CO2 hydrates. More investigations in this area are needed in the future. [ABSTRACT FROM AUTHOR]

ZnO nanoparticles functionalized with APTES were obtained to evaluate their CH4 and CO2 adsorption at 298 K in a range between 0 and 10 bar. First, ZnO nanoparticles were obtained by a precipitation method and subsequently coated with (3-aminopropyl)triethoxysilane (APTES). As a preliminary study, the results were compared with previously reported naked nanoparticles in order to evaluate the influence of APTES coating on CO2 selectivity. UV-Vis, FT-IR spectroscopy, TGA, XRD, TEM/EDX, XPS and N2 adsorption at 77 K were used to characterize the evaluated material. It was observed that the amount of gas adsorbed on the surface of the nanostructure was very small in comparison with other materials traditionally used for this purpose but slightly higher than those obtained in naked nanoparticles evaluated in previous studies. The affinity of CO2 for the amines groups of the APTES ligand was also discussed. [ABSTRACT FROM AUTHOR]

The Raman spectrum of CO2 from room temperature to 1800 K has been measured in a series of experiments. The differential Raman scattering cross-sections for the fundamental bands at 1285.41 cm−1 and 1388.18 cm−1 have been obtained from reference bands of H2 and N2 as intensity standards. The Raman cross-sections of CO2 hot bands, involving vibrational energy levels up to 5000 cm−1, were derived from those of the fundamental bands. The Raman cross-sections obtained this way were reduced to transition moments of the mean molecular polarizability, which make it possible to simulate the Raman spectrum of CO2 up to 2000 K. This paves the way for local or remote diagnostics of CO2 in hot environments using Raman based techniques. [ABSTRACT FROM AUTHOR]

Headwater wetlands are important sites for carbon storage and emissions. While local- and landscape-scale factors are known to influence wetland carbon biogeochemistry, the spatial and temporal heterogeneity of these factors limits our predictive understanding of wetland carbon dynamics. To address this issue, we examined relationships between carbon dioxide (CO2) and methane (CH4) concentrations with wetland hydrogeomorphology, water level, and biogeochemical conditions. We sampled water chemistry and dissolved gases (CO2 and CH4) and monitored continuous water level at 20 wetlands and co-located upland wells in the Delmarva Peninsula, Maryland, every 1–3 months for 2 years. We also obtained wetland hydrogeomorphologic metrics at maximum inundation (area, perimeter, and volume). Wetlands in our study were supersaturated with CO2 (mean = 315 μM) and CH4 (mean = 15 μM), highlighting their potential role as carbon sources to the atmosphere. Spatial and temporal variability in CO2 and CH4 concentrations was high, particularly for CH4, and both gases were more spatially variable than temporally. We found that groundwater is a potential source of CO2 in wetlands and CO2 decreases with increased water level. In contrast, CH4 concentrations appear to be related to substrate and nutrient availability and to drying patterns over a longer temporal scale. At the landscape scale, wetlands with higher perimeter:area ratios and wetlands with higher height above the nearest drainage had higher CO2 and CH4 concentrations. Understanding the variability of CO2 and CH4 in wetlands, and how these might change with changing environmental conditions and across different wetland types, is critical to understanding the current and future role of wetlands in the global carbon cycle. [ABSTRACT FROM AUTHOR]

This study evaluates the factors contributing to carbon emissions in China between 2002 and 2021, considering the impact of GDP growth, shocks in oil prices, trade liberalization and energy use. Using the dynamic simulated ARDL (SARDL) model, we indicate a long‐term link between trade liberalization, oil prices (WTI) shocks, GDP growth, energy use and CO2. The novel SARDL revealed a direct relationship between trade liberalization and CO2 in China in the long term. However, the results show a negative impact of WTI shocks on CO2 emissions. The study suggests that renewable energy (RE) significantly and negatively affects China's CO2 emissions. In addition, the findings conclude that, in the case of China, GDP has an insignificant long‐run relationship with CO2 emissions. The outcomes provide valuable insights for policymakers, researchers and industry stakeholders to enhance RE and promote sustainable energy practices. [ABSTRACT FROM AUTHOR]

• Energy, exergy, environment analyses and multi-objective optimization are performed for vortex tube coupled with transcritical refrigeration cycle (TVTC). • The parametric investigation is done to assess the thermodynamic performance of TVTC. • The cooling capacity of TVTC is found to be 10.1 % to 21.1 % higher than that of TVCR. • The maximum COP and exergetic efficiency of TVTC are higher than those of TVCR. • The evaporator temperature is the most influential input parameter in multi-objective optimization. The present study deals with the thermodynamic investigation of vortex tube coupled with trans-critical vapour compression refrigeration cycle (TVTC), followed by environmental analysis and multi-objective optimization. In this research, effect of various operating and design parameters is studied on the performance of TVTC. Furthermore, a comparison is made between the outcomes of TVTC and simple trans-critical vapour compression refrigeration cycle (TVCR). Results show that the optimum gascooler pressure for TVTC is observed to be lower than that of TVCR. Also, the cooling capacity and COP of TVTC are observed to be 10.1 % to 21.1 % and 2.3 % to 11.3 %, respectively, greater than those of TVCR. Moreover, the exergetic efficiency of TVTC is 2.3 % to 11.3 % higher than that of TVCR for the investigated range of evaporator and gascooler exit temperatures. The environmental penalty cost (per unit cooling capacity) of TVTC is 3.5 % to 12.2 % lower than that of TVCR. Furthermore, the coefficient of structural bond is calculated in order to choose the most sensitive parameters for system's performance. Additionally, genetic algorithm-based multi-objective optimization has been performed, with the evaporator temperature serving as the primary determining factor in establishing the optimal solution. This finding can guide the development of TVTC-based systems for a wide range of applications. [ABSTRACT FROM AUTHOR]

Copyright of Anaesthesiologie & Intensivmedizin is the property of DGAI e.V. - Deutsche Gesellschaft fur Anasthesiologie und Intensivmedizin e.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Anaesthesiologie & Intensivmedizin is the property of DGAI e.V. - Deutsche Gesellschaft fur Anasthesiologie und Intensivmedizin e.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The photocatalytic activity of catalysts depends on the energy-harvesting ability and the separation or transport of photogenerated carriers. The light absorption capacity of graphitic carbon nitride (g-C3N4)-based composites can be enhanced by adjusting the surface plasmon resonance (SPR) of noble metal nanoparticles (e.g., Cu, Au, and Pd) in the entire visible region. Adjustments can be carried out by varying the nanocomponents of the materials. The SPR of noble metals can enhance the local electromagnetic field and improve interband transition, and resonant energy transfer occurs from plasmonic dipoles to electron–hole pairs via near-field electromagnetic interactions. Thus, noble metals have emerged as relevant nanocomponents for g-C3N4 used in CO2 photoreduction and water splitting. Herein, recent key advances in noble metals (either in single atom, cluster, or nanoparticle forms) and composite photocatalysts based on inorganic or organic nanocomponent-incorporated g-C3N4 nanosheets are systematically discussed, including the applications of these photocatalysts, which exhibit improved photoinduced charge mobility in CO2 photoconversion and H2 production. Issues related to the different types of multi-nanocomponent heterostructures (involving Schottky junctions, Z-/S-scheme heterostructures, noble metals, and additional semiconductor nanocomponents) and the adjustment of dimensionality of heterostructures (by incorporating noble metal nanoplates on g-C3N4 forming 2D/2D heterostructures) are explored. The current prospects and possible challenges of g-C3N4 composite photocatalysts incorporated with noble metals (e.g., Au, Pt, Pd, and Cu), particularly in water splitting, CO2 reduction, pollution degradation, and chemical conversion applications, are summarized. [ABSTRACT FROM AUTHOR]

Today, passenger vehicle emissions alone represent 15% of global greenhouse gas emissions (GHG). The automobile industry is aware of this and has taken steps towards decarbonization over the past decade. Emissions related to the six phases of the life cycle were determined from the LCA database compiled on the basis of data collected on emissions during the life cycle of different types of vehicles, units, sizes and geographical areas. Typically, Internal Combustion Engine Vehicles (ICE) constantly emit CO2 while driving, whereas Battery Electric Vehicles (BEV) and Fuel Cell Electric Vehicles (FCEV) do not. The transition to an electric vehicle is only as clean as the energy source used to charge the vehicle. Each BEV car represents approximately 2.2 MWh/year of load on the country's electric power system, while due to the way energy is converted, the ICE car represents approximately 11.9 MWh/year of fuel-equivalent load. [ABSTRACT FROM AUTHOR]

Porous polymer show great potential for CO2 capture owing to its high specific surface area, adjustable porous structure and chemical structure. Herein, a novel CO2 adsorption materials ALP−M (M: Cu2+, Mg2+, Ni2+) were prepared through coordination between azo‐linked porous polymer (ALP) synthesized by oxidative coupling polymerization of tris(4‐aminophenyl)amine and metal ions. The structures and morphology of as‐prepared materials were demonstrated by FT‐IR, XRD, XPS, BET and SEM, the CO2 capture performance and mechanism of ALP−M were also investigated through static adsorption and column adsorption experments, the results show that metal ions can enhance the CO2 adsorption and desorption performance of ALPs by coordination adsorption. ALP−M showed a highest static CO2 adsorption capacity of 2.67 mmol g−1 at 273 K (1 bar), which is 35.5 % higher than that of ALP. The metal ions served as Lewis acid sites can enhance the affinity of adsorbent for CO2. In column adsorption experiments, the ALP−M showed a higher saturated adsorption capacity 4.99 mmol g−1 at 273 K (1 bar) than that of static adsorption, and excellent cycling stability after 500 adsorption and desorption cycles, the adsorption capacity retention rate of ALP−M for CO2 can reach 98 %. [ABSTRACT FROM AUTHOR]

Catalytic conversion of CO2 to valuable products is a promising way to reduce anthropogenic CO2 emission. Herein, a strategy for coupling conversion of CO2 and high‐carbon alkane to CO and gasoline is developed, which is a feasible choice for the combination of CO2 recycling and petroleum refining. The CO2 conversion reaches 2.6% under mild condition (270 °C), and the selectivity of gasoline in the cracking products exceeds 70 wt%. Additionally, the introduction of CO2 improves the selectivity of aromatic hydrocarbons and increases the octane number of gasoline. Mechanism studies indicate that synergistic effect between Brønsted acid centers and Ni sites on the Beta zeolite supported Ni (20 wt%) catalyst (20Ni/β) plays the key role in alkane cracking and CO2 reduction. Notably, 13CO2 isotopic experiments show that the hydrogen produced during the aromatization can be captured by CO2, inhibiting undesired hydrogen transfer pathways and enhanced the yield of aromatics, while CO2 is converted into valuable CO. [ABSTRACT FROM AUTHOR]

The intricate relationship between economic growth, environmental quality, and energy consumption has been extensively debated and studied on a global scale. The impacts of ecological quality on economic growth have been observed to be both positive and negative, particularly about human health as a result of pollutant emissions. It is essential to examine the compatibility between economic growth and environmental improvement, particularly through the reduction of emissions. This study aimed to investigate the connection between economic growth in forested areas and the corresponding impact on carbon dioxide (CO2) emissions in Nepal (Rose and Fisher, 1970). The analysis utilized time series data from 1990 to 2020, employing the dynamic ordinary least squares (DOLS) method. The DOLS results demonstrated a positive and statistically significant relationship between economic growth and CO2 emissions (Shafik and Bandyopadhyay, 1992). Specifically, an increase of Rs. 10 million in gross domestic product (GDP) corresponded to a 0.6112 kiloton increase in CO2 emissions. In contrast, the long‐term coefficient for forested areas exhibited a substantial association, indicating that a reduction of one square kilometer of forested area (deforestation) resulted in an increase of 68.37 kilotons in CO2 emissions in Nepal. These findings accentuate the divergent effects of economic progress and deforestation on carbon emissions in Nepal, with GDP growth contributing to a greater increase in emissions. Therefore, the implementation of effective strategies and economic measures, such as afforestation and reforestation, forest protection, sustainable forest management, and mechanisms like REDD+ (reducing emissions from deforestation and forest degradation plus), can play a vital role in mitigating carbon emissions while simultaneously addressing deforestation and ensuring long‐term economic progress in Nepal. [ABSTRACT FROM AUTHOR]

This research focuses on modeling CO2 absorption into alkanolamine solvents using multilayer perceptron (MLP), radial basis function network (RBF), Support Vector Machine (SVM), networks, and response surface methodology (RSM). The parameters, including solvent density, mass fraction, temperature, liquid phase equilibrium constant, CO2 loading, and partial pressure of CO2, were used as input factors in the models. In addition, the value of CO2 mass flux was considered as output in the models. Trainlm, trainbr, and trainscg algorithms trained the networks. The results showed that the best number of neurons for MLP with one layer is 16; with two layers, 5 neurons in the first layer and 12 neurons in the second layer; and with three layers, 9 neurons in the first layer, 5 neurons in the second layer, and 1 neuron in the third layer. The best spread in RBF was found to be 2.202 for optimal network performance. Furthermore, statistical data analysis revealed that the trainlm function performs best. The coefficients of determination for RSM, MLP, RBF, and SVM for optimized structures are obtained at 0.9802, 0.9996, 0.9940, and 0.8946, respectively. The results demonstrate that MLP and RBF networks can model CO2 absorption using the trainlm, trainbr, and trainscg algorithms. [ABSTRACT FROM AUTHOR]

The urgent need to mitigate climate change has spurred research into innovative carbon dioxide (CO2) capture materials. In this study, the design and synthesis of CO2‐responsive diblock copolymers, poly (N‐[3‐(dimethylamino)propyl]‐acrylamide)‐b‐poly(methyl methacrylate) (PDMAPAm‐b‐PMMA) are focused on via a two‐step reversible addition−fragmentation chain‐transfer (RAFT) polymerization as well as the application of the synthesized diblock copolymer as a membrane for CO2 capture. The resulting diblock copolymer possesses distinct blocks with varying properties. The poly (N‐[3‐(dimethylamino)propyl]‐acrylamide) (PDMAPAm) block provides CO2‐responsive behavior, while the poly(methyl methacrylate) (PMMA) block contributes to mechanical stability. The gas transport properties of the fabricated thin‐film composite membrane made of PDMAPAm‐b‐PMMA are measured. It is determined that the copolymer exhibits dual responsiveness towards CO2 and can be tailored for use in fabrication of membranes for direct air capture (DAC). [ABSTRACT FROM AUTHOR]

Inland waters are important sources of the greenhouse gases carbon dioxide (CO2) and methane (CH4). Ponds have amongst the highest CO2 and CH4 fluxes of all aquatic ecosystems, yet seasonal variation in fluxes remain poorly characterized, creating challenges for accurately estimating annual emissions. Further, ponds can exhibit a range of mixing regimes, yet the impact of mixing regimes on gas emissions remains unclear. Here, we assessed annual dynamics of CO2 and CH4 in four temperate ponds (Minnesota, USA) that varied in mixing regimes. The ponds ranged from annual sinks to sources of CO2 (−1 to 15 mol m−2 yr−1) and were all significant sources of CH4 (4.3–8.2 mol m−2 yr−1), with annual fluxes in CO2 equivalents of 1.8–4.1 kg CO2-eq. m−2 yr−1. Mixing regimes impacted CO2 and CH4 dynamics, as stratified periods were associated with more anoxia, greater accumulation of gases in the bottom waters, higher emissions of CH4, and lower fluxes of CO2. Ponds with stronger summer stratification also had increased CO2 and CH4 fluxes associated with fall turnover. Overall, the two ponds with the strongest stratification had higher annual fluxes (2.6, 4.1 kg CO2-eq. m−2 yr−1) compared to the two ponds that more frequently mixed (1.8, 2.2 kg CO2-eq. m−2 yr−1). [ABSTRACT FROM AUTHOR]

Pd–induced electron–migration of Co promotes C–C bond cleavage of glucose for selective production of active intermediate and hydrogen transfer, achieving CO 2 reduction efficiency 12.6–fold of the catalyst–free case. [Display omitted] Combining terrestrial biomass as the reductant with submarine-type hydrothermal environments for CO 2 reduction represents a possible approach for novel energy production systems that sustainably circulate carbon. However, increasing the reductive power of biomass is the main limitation of this potential method. Herein, we demonstrate that Co-doped with small amounts of Pd enhances the reduction of CO 2 by selectively producing an active intermediate from carbohydrates. This catalytic reaction utilized glucose as a reductant to achieve high formate production efficiency (458.6 g kg−1) with nearly 100% selectivity with 7.5 wt% Pd 1 Co 20 / γ –Al 2 O 3 at a moderate temperature of 225 °C. The regulation of the electronic structure of the catalytic Co surface by the dopant Pd plays a key role in promoting the C–C bond cleavage of glucose and hydrogen transfer for CO 2 reduction. The findings presented here indicate that biomass can serve as the hydrogen source for CO 2 reduction and provide insight into the potential utilization of CO 2 in sustainable industrial applications. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2) is a crucial greenhouse gas, and its concentration and spatiotemporal characteristics are among the principal sources of uncertainty in global warming assessments. Satellite remote sensing is a widely adopted, high-accuracy approach for monitoring atmospheric CO 2. However, limited swath width and cloud cover significantly reduce satellite observation coverage. This study addresses the temporal changes in CO 2 concentration and utilizes a machine learning-based fusion of multiple data sources to generate daily, full-coverage, 0.05° spatial resolution column-averaged CO 2 concentration data for China from 2015 to 2020. Ten-fold cross-validation yielded a determination coefficient R2 of 0.97, root mean square error of 0.92 ppm, and mean absolute error of 0.59 ppm. Compared to other datasets, this study's dataset exhibits superior accuracy and spatiotemporal detail. Using the produced CO 2 concentration data in this study, we conducted a spatiotemporal analysis of CO 2 concentrations in China. The results indicate that, in general, the Western region exhibits a higher growth rate in CO 2 concentration than the Eastern and Central regions, with areas of lower CO 2 concentration experiencing higher growth rates while regions with higher CO 2 concentration have lower growth rates. Moreover, the highest increase in CO 2 concentration occurred in 2016, with a substantial decrease in CO 2 concentration growth observed in 2018. Notably, the reduction in CO 2 concentration in the Qinghai-Tibet Plateau region during the summer is considerably smaller than in other regions, possibly due to atmospheric transport from the Indian Peninsula. [ABSTRACT FROM AUTHOR]

Understanding the density of CO2 + n-decane is crucial for designing and operating CO2 capture, transport, and storage. The safety and effectiveness of CO2 burial is directly affected by the density of CO2 + n-decane mixtures. The liquid densities of CO2(1) + n-decane(2) mixtures with mole fractions of CO2 x1 = 0, 0.2032, 0.4434, 0.7589, and 0.8947 were measured using a vibrating tube densimeter. The combined expanded uncertainties of density with a level of confidence of 0.95 are estimated to be 0.6 kg·m−3. A total of 221 compressed liquid densities of CO2(1) + n-decane(2) mixtures along the five isotherms between T = (283 and 363) K with pressures up to 100 MPa were presented. The densities of mixtures were correlated by the modified Tait equation, resulting in absolute average deviations between the experimental and calculated values of 0.028%, 0.013%, 0.017%, 0.044%, and 0.042%. In addition, the isothermal compressibility, isobaric thermal expansivity, and excess molar volume were derived from the modified Tait equation. [ABSTRACT FROM AUTHOR]

The significance of the transportation sector, notably in terms of the carbon emission factor, is an undeniable fact. Along with this fact, individuals' transportation preferences depend on their income levels. In this context, when the issue is considered, the income level in the USA pushes people toward cheap air travel. The main reason for this is that it is cheap, accessible, and transports one to their destinations quickly. Thus, from the perspective of road transportation, bus transportation is popular among the public. The reason why both air and road transportation modes are empirically evaluated together through income distribution is due to the preference of the US people. In this context, the effectiveness of active transportation on both air and highways in the USA from 1975 to 2023 is investigated by taking into consideration the income distribution. Empirical findings obtained through the FMOLS, DOLS, CCR, and NARDL models demonstrate that all independent variables, including GDP, energy use, air transportation, and the Gini coefficient, affect carbon dioxide emissions. In addition, wavelet analysis is performed to comprehend the form of and fluctuations in the series, which are vital to monitoring the periodical changes. [ABSTRACT FROM AUTHOR]

Real‐time monitoring of carbon dioxide (CO2) is imperative for medical diagnosis and effective environmental preservation. Despite the formidable challenge posed by the inherent chemical inertness of CO₂ molecules, a pioneering CO2 sensor based on MOF‐804 cofunctionalized with ionic liquid (IL) and m‐cresol purple (mCP) is successfully developed. By ingeniously integrating hydrogen bonding, electrostatic interactions, and hydrophobic properties within the sensitive layer, the sensor achieves a state‐of‐the‐art sensitivity (Δf = 384 Hz), an exceptionally vast detection range spanning 400–80 000 ppm, and remarkable stability with minimal sensitivity drift even at relative humidity (RH) levels exceeding 80%. Furthermore, the inherent gasochromic property, stemming from the zwitterionic mechanism, paves the way for innovative self‐sustaining CO2 test strips and groundbreaking applications, including CO2 tracking and CO2‐encrypted security labeling technology. Collectively, the realization of this ultra‐sensitive and robust CO2 monitoring approach, coupled with its CO2‐triggered visual and multifunctional capabilities, opens up novel avenues for dynamic CO2 detection, advanced military encryption strategies, and enhanced health management systems. [ABSTRACT FROM AUTHOR]

The contemporary focus on global concerns such as carbon dioxide (CO2) emissions impacting the environment and contributing to the energy crisis has prompted exploration into alternatives, with photocatalysis emerging as a potential solution. This research involved the development of a PT (TiO2) photocatalyst, synthesized through the hydrothermal method and enhanced with double co‐catalysts of copper and nickel via the wet impregnation technique. The characteristics of the resulting photocatalysts were comprehensively examined using various techniques, including XRD, Raman, UV‐Vis DRS, surface area and pore analysis, SEM‐EDX, HRTEM, XPS, PL, and EPR. The characterization outcomes revealed that the PT phase comprised anatase, brookite, and rutile. The incorporation of double co‐catalysts was evident through the emergence of new peaks in the XRD diffraction pattern, corroborated by SEM, HRTEM, and XPS analysis. In the activity test, CNT‐4 (Cu−Ni/TiO2‐400) exhibited the highest methanol yield at 772.41 μmole g−1 h−1, followed by CONTT‐4 (CuO−NiTiO3/TiO2‐400) with 750.38 μmole g−1 h−1 after three hours of irradiation using a 300 W xenon lamp, while methanol in PT formed only after three hours of irradiation. The presence of co‐catalysts significantly influenced methanol yield, attributed to the increased active sites for the reaction and the reduced band gap, impacting light absorption optimization and suppressing electron‐hole recombination. In CNT‐4, the formation of Ti3+ associated with oxygen vacancies facilitated the generation of more products. [ABSTRACT FROM AUTHOR]

[Objective] In order to accurately estimate net primary productivity (NPP) of vegetation under the context of rising atmospheric C*O_{2} concentrations. Methods] A C*O_{2} concentration factor was introduced into he Carnegie-Ames-Stanford Approach (CASA) model to simulate the maximum light use efficiency of different vegetation types. Based on this, the potential of the improved model for NPP estimation was explored. [Results] From 2000 to 2020, the annual average atmospheric C*O_{2} concentration in China's errestrial areas showed a significant increasing trend, with an average increase of approximately 2.14mu*mol / mona). After incorporating the C*O_{2} stress factor, the vegetation types were ranked by maximum light use efficiency in the following order cropland evergreen broadleaf forest mixed forest needleleaf forest> shrub wetland grassland (1.85, 1.69, 1.30, 0.87, 0.52, 0.40, 0.40 g/MJ). The estimation accuracy of NPP by the C*O_{2} model was improved compared to the original CASA model. The R 2 between the simulated and measured NPP values at the vegetation level and the comprehensive level increased by -0.1% to 3.7% and 0.5%, respectively, and RMSE decreased by 0.3% to 9.2% and 0.7%, respectively. The RMSE of annual NPP estimation results decreased by 1.9%. The C*O_{2} model improved the underestimation of overall NPP by the CASA model. reducing it from 10.62% to 9.81%. The C*O_{2} model underestimated the overall NPP for spring, autumn and winter by 11% 72 * 0/0 and 51 * 0/0, respectively, while overestimating it for summer by 0.53% [Conclusion] Considering the impact of C*O_{2} concentration changes on vegetation in the model can improve the accuracy of NPP estimation. [ABSTRACT FROM AUTHOR]

Carbonatites are rare igneous rocks that host the largest resources of REE and Nb, yet, their genesis and evolution are far from clear. The leading models of carbonatite formation are the direct melting of carbonate-bearing peridotites, silicate-carbonatite liquid immiscibility, and fractionation of carbonated silicate melts. The validity of these models has never been robustly addressed through combining the available experimental results with the natural rock record. We thus re-evaluate the presently 633 alleged carbonatite occurrences including carbonatite type, bulk composition, mineralogy, and field exposure, followed by a review of experimental data pertinent to carbonatite genesis and evolution. Based on the available data, 454 carbonatite occurrences are magmatic, of which 87 without and 338 with spatially associated alkaline magma, 9 with kimberlites, and 20 with ultramafic cumulates only. Eighty-four percent of the magmatic occurrences contain calcite carbonatite (of which 1/3 also contain dolomite carbonatite), only 9% have dolomite but not calcite carbonatite, the incidence of dolomite carbonatite being similar for occurrences with or without associated silicate magmas. Available experimental data show that crystallization of calcite, dolomite, ankerite, and siderite at crustal conditions requires moderately alkaline and/or hydrous carbonate melts with ≥20 to 25 wt % (Na,K)2CO3 + H2O. It follows that carbonatite rocks, poor in these elements, are at best magmatic cumulates (if not carbo- or hydrothermal) that lost these ephemeral components. Carbonatitic melts could form in the lithospheric mantle, but these are always dolomitic and cannot deviate from close-to-minimum compositions when rising, their strong adiabatic cooling keeping them on the solidus until they decompose to olivine, clinopyroxene (cpx), and CO2 when reaching <2.1 GPa, i.e. the carbonated peridotite solidus ledge, which renders their extraction from the mantle highly unlikely. Furthermore, dolomitic carbonate melts crystallize periclase + calcite at crustal conditions. Only when containing ≥15 wt % (Na,K)2O + H2O they may crystallize dolomite and form dolomitic carbonatites. This value is far above the 2 to 5 wt % (Na,K)2O of mantle-derived carbonatitic melts. Liquid immiscibility from CO2-bearing close-to-natural melilititic, nephelinitic, and phonolitic melts requires 10 to 15 wt % Na2O + K2O in the silicate melt, increasing with SiO2. Extensive differentiation of primitive alkaline melilititic or basanitic parents is hence required to achieve immiscibility. The experimental data show that evolved nephelinites and phonolites unmix calcic carbonatitic melts, while melilitites and undifferentiated nephelinites with >4 wt % MgO may also unmix dolomitic carbonatitic melts. The latter may hence arise from liquid immiscibility or develop through fractionation from calcic carbonatitic melts. Finally, carbonatites may also derive through fractionation of CO2-rich ultramafic melts, but a continuous increase in dissolved CO2 from a carbonated silicate melt to a carbonatitic melt requires ≥3 GPa. We conclude that the combination of the natural rock record with melting and crystallization phase relations excludes a direct mantle origin for almost all carbonatites found in the crust. Instead, their vast majority forms through immiscibility from an alkali-rich differentiated silicate melt that stems from a mantle-derived alkaline parent, consistent with the common spatial association with alkaline complexes and similar isotopic compositions of carbonatite and alkaline silicate rocks. Direct fractionation from silicate melts may occur for kimberlitic or ultramafic lamprophyric melts, but only at ≥3 GPa, i.e. within the lithospheric mantle. To make progress in this field, we suggest a more rigorous distinction of magmatic and carbo- or hydrothermal carbonatite rocks in each occurrence, and to focus on mineral compositions in the carbonatite and associated silicate magmas, as bulk rocks are at best cumulative in nature. Additional experimental work to understand the role of alkalis and H2O in the formation and evolution of carbonatites, in particular crystallization and fluid saturation at crustal conditions, will be essential to provide a more complete understanding of carbonatite petrogenesis. [ABSTRACT FROM AUTHOR]

Leaf respiratory carbon loss decreases independent of temperature as the night progresses. Detailed nighttime measurements needed to quantify cumulative respiratory carbon loss at night are challenging under both lab and field conditions. We provide a simple yet accurate approach to represent variation in nighttime temperature‐independent leaf respiratory CO2 efflux in environments with both stable and fluctuating temperatures, which requires no detailed measurements throughout the night. We demonstrate that the inter‐ and intraspecific variation in the cumulative leaf respiratory CO2 efflux at constant temperature, at any length of night, scales linearly with the inter‐ and intraspecific variation in initial measurement of leaf respiratory CO2 efflux at the same temperature at the beginning of the night. This approach informs large‐scale predictions of cumulative leaf respiratory CO2 efflux, which is needed to understand plant carbon economy in global change studies as well as in global modeling and eddy covariance monitoring of the land–atmosphere exchange of CO2. [ABSTRACT FROM AUTHOR]

Spontaneous coal combustion adversely affects coal mine safety and restricts safe, efficient, and green coal mining. Inert gas fire prevention and extinguishing technology is a widely used fire prevention and extinguishing method in coal mines. CO2 is often used as the primary raw material for inert gas fire prevention and extinguishing, owing to its good inerting and cooling characteristics. However, the lack of data on the physical and chemical properties and fire extinguishing mechanism of CO2 by field personnel has limited the efficient application of CO2 in coal mine fire prevention and extinguishing. To explore the practical application effects of CO2 fire prevention and extinguishing technology on coal mine sites, this paper summarised and analysed the research and development status of CO2 fire prevention and extinguishing technology and expounded the physical and chemical properties, phase characteristics, and fire prevention and extinguishing mechanisms of CO2. The CO2 pipeline, CO2 pipeline intelligent monitoring and control system, CO2 inerting mechanism, and comprehensive gas fire prevention and extinguishing technology are summarised and discussed. This study provides a systematic theoretical basis for the field application of CO2 fire prevention and extinguishing technology. [ABSTRACT FROM AUTHOR]

We used stable and nontoxic [(dimethylamino)methyl]ferrocene (Fc‐N), (hydroxymethyl)ferrocene (Fc‐O), 1,2‐bis[(dimethylamino)methyl]ferrocene (Fc‐N2), and 1‐[(dimethylamino)methyl]‐2‐(hydroxymethyl)ferrocene (Fc‐NO) as halide‐free, neutral, and bifunctional one‐component catalysts for the synthesis of cyclic carbonates. They do not need halide‐based additives or tethered salts attached to ligands when used for this coupling reaction. Among them, Fc‐N2 exhibited the best catalytic activity under the same reaction conditions. Catalytic activity decreased rapidly in the order Fc‐N2 > Fc‐NO > Fc‐N > Fc‐O, and interestingly, the more amino groups introduced into the Cp groups, the higher the activity. Various terminal and internal epoxides were easily converted into the corresponding cyclic carbonates. Calculations based on the density functional theory were also carried out to elucidate the mechanism of the coupling reaction. [ABSTRACT FROM AUTHOR]

Sequential (S) and equal-time (ET) methods were applied to assess the temperature sensitivity of respiration of peat soils in different terrestrial ecosystems: southern tundra, northern taiga, and mixed coniferous–broadleaved forests. The Q10 values varied widely (1.3–4.8) and in case of the ET method decreased from northern to temperate latitudes. In the cold range (5–15°С), Q10 increased from the southern tundra (3.5) to the northern taiga (4.8) and then sharply decreased in the zone of mixed forests (2.5). Meanwhile, warm range (15–25°С) showed a clear decline of Q10 from northern to temperate latitudes: southern tundra (2.6) > northern taiga (1.6) > coniferous–broadleaved forests (1.3). Application of the S method resulted in low variability of Q10 values. Our results demonstrate a higher temperature sensitivity of the respiration of peat soils in northern latitudes as compared to that in the temperate zone. The Q10 values obtained in this study can be useful for calibration of regional carbon cycle datasets that consider the contribution of peat soils. [ABSTRACT FROM AUTHOR]

The results of high-precision direct determination of CO2 in the surface waters of the Black Sea are presented. These measurements made possible to obtain high precision characteristics of the content and intra-annual variations in pCO2 for the first time. The average annual value of pCO2 is 436 µatm, which is higher than the average annual value in the near-sea surface layer of the atmosphere (420 µatm). The seasonal variability has revealed decrease of pCO2 in seawater from late spring to fall. The minimum values of pCO2 are detected in January–February; the maximum ones, in July. The seasonal variations in the CO2 content in the near-sea atmosphere reveal an inverse relationship, with maximum values in February and minimum values in July. This indicates different mechanisms of the evolution of CO2 in the air and seawater. The content of CO2 in the atmosphere is determined by external sources and depends on the burning intensity of organic carbon. Variations in pCO2 in water is significantly affected by abiotic factors, such as the influence of temperature change on CO2 solubility and the state of the carbon system. In the summer–fall season, pCO2 is determined by a combination of abiotic and biotic factors, including variations in temperature and intensity of biological processes of organic matter transformation. Both the intensity and effect of these factors vary throughout the year, but the abiotic factor remains primay during the entire year. [ABSTRACT FROM AUTHOR]

This study examines the impact of CO2 concentration on the stability and plugging performance of polymer-enhanced foam (PEF) under high-temperature and high-pressure conditions representative of the steam front in heavy oil reservoirs. Bulk foam experiments were conducted to analyze the foam performance, interfacial properties, and rheological behavior of CHSB surfactant and Z364 polymer in different CO2 and N2 gas environments. Additionally, core flooding experiments were performed to investigate the plugging performance of PEF in porous media and the factors influencing it. The results indicate that a reduction in CO2 concentration in the foam, due to the lower solubility of N2 in water and the reduced permeability of the liquid film, enhances foam stability and flow resistance in porous media. The addition of polymers was found to significantly improve the stability of the liquid film and the flow viscosity of the foam, particularly under high-temperature conditions, effectively mitigating the foam strength degradation caused by CO2 dissolution. However, at 200 °C, a notable decrease in foam stability and a sharp reduction in the resistance factor were observed. Overall, the study elucidates the effects of gas type, temperature, and polymer concentration on the flow and plugging performance of PEF in porous media, providing reference for fluid mobility control at the steam front in heavy oil recovery. [ABSTRACT FROM AUTHOR]

Some of the issues concerning energy security and climate change can be addressed by employing nuclear power (NP) to supply the energy required for the conversion of carbon dioxide (CO2) into chemicals, products, and materials. Nuclear energy represents a neutral carbon source that can be generated sustainably, reliably, and consistently. Nuclear power plants (NPPs) could supply energy in the form of heat, electricity, and ionizing radiation to drive CO2 chemical reactions underpinning NP-to-X type of pathways. CO2 conversion processes are either commercially available or emerging technologies at different developmental maturity stages. This work reviews the published literature (articles and patents) that reports R&D results and the understanding and development of chemical reactions and processes, as well as the efforts in integrating NPPs and chemical processes (CPs). As will be made evident, a new industrial era for the manufacturing of decarbonized chemicals, products, and materials will be possible by developing and implementing new (more energy- and carbon-efficient) processes responding to the NP-to-X pathways. This new decarbonizing platform not only contributes to achieving net zero goals but also broadens the NPP product beyond electricity. [ABSTRACT FROM AUTHOR]

The internalization of the social cost of carbon (SCC) is the most efficient alternative to reduce the emissions that cause global warming. However, the carbon pricing initiatives implemented in many countries differ significantly from the empirical estimates of the SCC. Therefore, this study simulates the economic and environmental effects of internalizing the SCC in all the world’s nations through the environmental extension of a multi-regional input–output (MRIO) price model. The results show that the most affected countries economically are characterized by having an energy matrix with high participation of fossil fuels. In addition, there are relevant increases in the prices of energy and food, which are likely to raise poverty rates in low- and middle-income countries. It is concluded that the global emission reduction can vary between 5.1% and 50.3% depending on the SCC used, and only ten countries explain 77% of this reduction. In addition, global emissions reduction falls if data from a more recent base year is used, demonstrating that the structural transformations of the economy also strongly affect the impacts of carbon pricing. Finally, it is recommended that energy efficiency measures be incentivized to address partially this cost shock. [ABSTRACT FROM AUTHOR]

In general, mantle-derived volatiles are mainly released into the atmosphere through volcanoes in mid-ocean ridges and subduction zones. However, relatively little attention has been paid to the emission of volatiles from continents on the Earth's surface. It has recently been shown that significant amounts of gases such as carbon dioxide of mantle origin are emitted from continental rifts. Continental degassing has been reported in various ways around the world, however compared to mid-ocean ridges where the depleted upper mantle contributes significantly or arc volcanoes affected by subduction slabs, geochemical generalization is still in progress. In particular, in continental environments, other volatile sources may be added due to the distribution of the subcontinental lithospheric mantle. In the previously reported mantle xenolith samples, components such as noble gases are distinct from the mid-ocean ridge gases, and volcano/fault-related gases on some continents also showed different characteristics. Here, this work proposes representative values of volatiles of the lithosphere by synthesizing the geochemical data of gases emitted from the continent that have been reported until recently. In addition, this study provides a new perspective by considering the recently reported gas results from South Korea. [ABSTRACT FROM AUTHOR]

Mg-based nanofluid fuel is a promising fuel for propulsion system in Mars exploration. In this study, Mg-based nanofluid fuel were prepared by one-step method, and the effect of Mg(magnesium) content, Mg size(68 μm,110 μm,175 μm), and oleic acid (OA) on droplet ignition and combustion under the atmosphere of 90 % CO 2 and 10 % O 2 were investigated. According to the TG-DSC results, 68 m Mg particles under CO 2 had the highest exothermic efficiency of 4472 J/g. The combustion of Mg/OA/kerosene droplets consists of five stages: ignition, d2-law combustion, micro-explosion, vapor flame extinguishment, and agglomerate explosion. The ignition delay time of Mg (68 μm, 5 %)/kerosene is 0.045s, which is half that of kerosene (0.0890s). The agglomerates explode violently and emit a brilliant white light at the end of the Mg-based nanofluid fuel combustion. The explosive effect of Mg agglomerates diminishes as the Mg content increases. The rate of combustion decreases with increasing particle size. In the sample with added oleic acid, Mg (68 μm, 5 %)/OA/kerosene shows the best combustion rate of 0.6320 mm2/s. Finally, a numerical model for the combustion of Mg-based nanofluid fuel droplets is proposed. The predictions are within 2 % of the experimental results. The findings are expected to explore future in-situ utilization of CO 2 on the Mars surface. • Combustion characteristics of a novel Mg-based nanofluid fuel for Mars are studied. • Effects of Mg particle size and content on the combustion properties are analyzed. • The optimal Mg-based nanofluid fuel formulation is Mg (5 wt%, 68um)/OA/kerosene. • A numerical model for the combustion of Mg-based nanofluid fuel droplet is proposed. [ABSTRACT FROM AUTHOR]

Copyright of African Journal of Reproductive Health is the property of Women's Health & Action Research Centre and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)