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Motivated by the multiferroic effects and quantum magnetization plateaus in the skew chain antiferromagnets T 2 V 2 O 7 (T = Ni, Co), we have conducted a detailed density function theoretical study on Co 2 V 2 O 7. The results show that the nearest-neighbor interchain interaction (J 3 / k B = − 35.57 K) is not much greater than the intrachain interactions (J 1 / k B = − 19.54 K and J 2 / k B = 27.55 K), showing the absence of interchain dimerization of the Co ions. This indicates that the "dimer+monomer" model used for Ni 2 V 2 O 7 [Cao et al., Phys. Rev. B 106, 184409 (2022)] is no longer applicable to Co 2 V 2 O 7. Finally, the exact diagonalization of spin Hamiltonian, including anisotropic exchanges, produces the experimentally observed 1/2 and 3/4 magnetization plateaus. [ABSTRACT FROM AUTHOR]

Motivated by the multiferroic effects and quantum magnetization plateaus in the skew chain antiferromagnets T 2 V 2 O 7 (T = Ni, Co), we have conducted a detailed density function theoretical study on Co 2 V 2 O 7. The results show that the nearest-neighbor interchain interaction (J 3 / k B = − 35.57 K) is not much greater than the intrachain interactions (J 1 / k B = − 19.54 K and J 2 / k B = 27.55 K), showing the absence of interchain dimerization of the Co ions. This indicates that the "dimer+monomer" model used for Ni 2 V 2 O 7 [Cao et al., Phys. Rev. B 106, 184409 (2022)] is no longer applicable to Co 2 V 2 O 7. Finally, the exact diagonalization of spin Hamiltonian, including anisotropic exchanges, produces the experimentally observed 1/2 and 3/4 magnetization plateaus. [ABSTRACT FROM AUTHOR]

Purpose: To measure the surface temperature distribution after using a CO2 laser to heat titanium dental implants via different power settings, application intervals, and irradiation times. Materials and Methods: A total of 10 tissue-level titanium implants (Screw-Line Promote Plus, Camlog; 4.3 × 11 mm) were placed (EpoFix, Struers) and irradiated with a CO2 laser (Denta 2, Lutronic) with a wavelength of 10.6 µm at power levels of 4 watts (Group 1), 6 watts (Group 2), 8 watts (Group 3), and 10 watts (Group 4). A continuous beam mode (setting I) and noncontinuous beam modes with 5-second (setting II) and 10-second (setting III) pause intervals were used. For each setting, a total irradiation time of 50 seconds was used and repeated 10 times. The temperature was measured using external thermocouple (Testo) in contact with the implant surface at the implant shoulder, middle, and apex. A linear regression model was used to analyze the data (P = .05). Results: Setting I demonstrated the most rapid increase in implant surface temperature in all three test sites as well as the greatest total temperature at 50 seconds of irradiation time. The greater the pause interval (settings II and III) during the 50 seconds of irradiation, the lower the rate of temperature increase as well as the total temperature in all three test sites and with all power levels. The average temperature difference between the apex and shoulder site was significant for setting III for all groups, but not for any groups in settings I and II. Conclusions: Heating the internal aspect of an implant with a CO2 laser produces different temperature distribution profiles depending on the laser power level and the application interval. Laser-beam irradiation leads to a temperature gradient, which is greatest at the implant apex and smallest at the implant shoulder. [ABSTRACT FROM AUTHOR]

Localization procedures are an important tool for analysis of complex systems in quantum chemistry, since canonical molecular orbitals are delocalized and can, therefore, be difficult to align with chemical intuition and obscure information at the local level of the system. This especially applies to calculations obeying periodic boundary conditions. The most commonly used approach to localization is Foster–Boys Wannier functions, which use a unitary transformation to jointly minimize the second moment of the orbitals. This procedure has proven to be robust and fast but has a side effect of often mixing σ - and π -type orbitals. σ / π -separation is achieved by the Pipek–Mezey Wannier function (PMWF) approach [Lehtola and Jónsson, J. Chem. Theory Comput. 10, 642 (2014) and Jónsson et al., J. Chem. Theory Comput. 13, 460 (2017)], which defines the spread functional in terms of partial charges instead. We have implemented a PMWF algorithm in the CP2K software package using the Cardoso–Souloumiac algorithm to enable their application to real-time time-dependent density functional theory. The method is demonstrated on stacked CO 2 molecules, linear acetylenic carbon, boron and nitrogen co-doped graphene, and nitrogen-vacancy doped diamond. Finally, we discuss its computational scaling and recent efforts to improve it with fragment approaches. [ABSTRACT FROM AUTHOR]

Purpose: To assess (1) whether and how a higher maximal lactate steady state (MLSS) at higher cycling cadence (RPM) comes along with higher absolute and/or fractional carbohydrate combustion (CHOMLSS), respectively, and (2) whether there is an interrelation between potential RPM-dependent MLSS effects and the maximally achievable RPM (RPMMAX). Methods: Twelve healthy males performed incremental load tests to determine peak power, peak oxygen uptake, and 30-minute MLSS tests at 50 and 100 per minute, respectively, to assess RPM-dependent MLSS, corresponding power output, CHOMLSS responses, and 6-second sprints to measure RPMMAX. Results: Peak power, peak carbon dioxide production, and power output at MLSS were lower (P =.000, ω2 = 0.922; P =.044, ω2 > 0.275; and P =.016, ω2 = 0.373) at 100 per minute than at 50 per minute. With 6.0 (1.5) versus 3.8 (1.2) mmol·L−1, MLSS was higher (P =.000, ω2 = 0.771) at 100 per minute than at 50 per minute. No corresponding RPM-dependent differences were found in oxygen uptake at MLSS, carbon dioxide production at MLSS, respiratory exchange ratio at MLSS, CHOMLSS, or fraction of oxygen uptake used for CHO at MLSS, respectively. There was no correlation between the RPM-dependent difference in MLSS and RPMMAX. Conclusions: The present study extends the previous finding of a consistently higher MLSS at higher RPM by indicating (1) that at fully established MLSS conditions, respiration and CHOMLSS management do not differ significantly between 100 per minute and 50 per minute, and (2) that linear correlation models did not identify linear interdependencies between RPM-dependent MLSS conditions and RPMMAX. [ABSTRACT FROM AUTHOR]

In this work, the effect of the range of dispersive interactions in determining the three-phase coexistence line of the CO2 and CH4 hydrates has been studied. In particular, the temperature (T3) at which solid hydrate, water, and liquid CO2/gas CH4 coexist has been determined through molecular dynamics simulations using different cutoff values (from 0.9 to 1.6 nm) for dispersive interactions. The T3 of both hydrates has been determined using the direct coexistence simulation technique. Following this method, the three phases in equilibrium are put together in the same simulation box, the pressure is fixed, and simulations are performed at different temperatures T. If the hydrate melts, then T > T3. Conversely, if the hydrate grows, then T < T3. The effect of the cutoff distance on the dissociation temperature has been analyzed at three different pressures for CO2 hydrate: 100, 400, and 1000 bar. Then, we have changed the guest and studied the effect of the cutoff distance on the dissociation temperature of the CH4 hydrate at 400 bar. Moreover, the effect of long-range corrections for dispersive interactions has been analyzed by running simulations with homo- and inhomogeneous corrections and a cutoff value of 0.9 nm. The results obtained in this work highlight that the cutoff distance for the dispersive interactions affects the stability conditions of these hydrates. This effect is enhanced when the pressure is decreased, displacing the T3 about 2–4 K depending on the system and the pressure. [ABSTRACT FROM AUTHOR]

In this work, the effects of finite size on the determination of the three-phase coexistence temperature (T3) of the carbon dioxide (CO2) hydrate have been studied by molecular dynamic simulations and using the direct coexistence technique. According to this technique, the three phases involved (hydrate–aqueous solution–liquid CO2) are placed together in the same simulation box. By varying the number of molecules of each phase, it is possible to analyze the effect of simulation size and stoichiometry on the T3 determination. In this work, we have determined the T3 value at 8 different pressures (from 100 to 6000 bar) and using 6 different simulation boxes with different numbers of molecules and sizes. In two of these configurations, the ratio of the number of water and CO2 molecules in the aqueous solution and the liquid CO2 phase is the same as in the hydrate (stoichiometric configuration). In both stoichiometric configurations, the formation of a liquid drop of CO2 in the aqueous phase is observed. This drop, which has a cylindrical geometry, increases the amount of CO2 available in the aqueous solution and can in some cases lead to the crystallization of the hydrate at temperatures above T3, overestimating the T3 value obtained from direct coexistence simulations. The simulation results obtained for the CO2 hydrate confirm the sensitivity of T3 depending on the size and composition of the system, explaining the discrepancies observed in the original work by Míguez et al. [J. Chem Phys. 142, 124505 (2015)]. Non-stoichiometric configurations with larger unit cells show a convergence of T3 values, suggesting that finite-size effects for these system sizes, regardless of drop formation, can be safely neglected. The results obtained in this work highlight that the choice of a correct initial configuration is essential to accurately estimate the three-phase coexistence temperature of hydrates by direct coexistence simulations. [ABSTRACT FROM AUTHOR]

Climate changes significantly impact greenhouse gas emissions from wetland soil. Specifically, wetland soil may be exposed to oxygen (O2) during droughts, or to sulfate (SO42-) as a result of sea level rise. How these stressors - separately and together - impact microbial food webs driving carbon cycling in the wetlands is still not understood. To investigate this, we integrated geochemical analysis, proteogenomics, and stoichiometric modeling to characterize the impact of elevated SO42- and O2 levels on microbial methane (CH4) and carbon dioxide (CO2) emissions. The results uncovered the adaptive responses of this community to changes in SO42- and O2 availability and identified altered microbial guilds and metabolic processes driving CH4 and CO2 emissions. Elevated SO42- reduced CH4 emissions, with hydrogenotrophic methanogenesis more suppressed than acetoclastic. Elevated O2 shifted the greenhouse gas emissions from CH4 to CO2. The metabolic effects of combined SO42- and O2 exposures on CH4 and CO2 emissions were similar to those of O2 exposure alone. The reduction in CH4 emission by increased SO42- and O2 was much greater than the concomitant increase in CO2 emission. Thus, greater SO42- and O2 exposure in wetlands is expected to reduce the aggregate warming effect of CH4 and CO2. Metaproteomics and stoichiometric modeling revealed a unique subnetwork involving carbon metabolism that converts lactate and SO42- to produce acetate, H2S, and CO2 when SO42- is elevated under oxic conditions. This study provides greater quantitative resolution of key metabolic processes necessary for the prediction of CH4 and CO2 emissions from wetlands under future climate scenarios.

Cities represent a significant and growing portion of global carbon dioxide (CO2) emissions. Quantifying urban emissions and trends over time is needed to evaluate the efficacy of policy targeting emission reductions as well as to understand more fundamental questions about the urban biosphere. A number of approaches have been proposed to measure, report, and verify (MRV) changes in urban CO2 emissions. Here we show that a modest capital cost, spatially dense network of sensors, the Berkeley Environmental Air Quality and CO2 Network (BEACO2N), in combination with Bayesian inversions, result in a synthesis of measured CO2 concentrations and meteorology to yield an improved estimate of CO2 emissions and provide a cost-effective and accurate assessment of CO2 emissions trends over time. We describe nearly 5 years of continuous CO2 observations (2018-2022) in a midsized urban region (the San Francisco Bay Area). These observed concentrations constrain a Bayesian inversion that indicates the interannual trend in urban CO2 emissions in the region has been a modest decrease at a rate of 1.8 ± 0.3%/year. We interpret this decrease as primarily due to passenger vehicle electrification, reducing on-road emissions at a rate of 2.6 ± 0.7%/year.

The rare earth alloy Y 2 Co 17 − x Ni x was prepared by a low-cost co-precipitation reduction-diffusion process, and its crystal structure, static magnetic properties, and microscopic morphology were systematically characterized. The effects of Ni doping with different contents on the electromagnetic parameters and wave absorption properties of Y 2 Co 17 − x Ni x /polyurethane(PU) compounds were researched in the frequency range of 0.1–18 GHz. The results show that the static magnetic properties and wave absorption properties change significantly with Ni doping, and the maximum reflection loss of Y 2 Co 14 Ni 3 /PU reaches − 89.7 dB at 2.9 mm thickness, and the maximum reflection loss peaks of Y 2 Co 17 /PU and Y 2 Co 16 Ni 1 /PU are at 1.316 and 1.515 GHz, which is at the center frequency of the L-band. With Ni doping, the effective absorption bandwidth of the compounds at a frequency above 3 GHz is greatly increased. The physical factor in the bandwidth calculation was modified, and the effective absorption bandwidth of the material was calculated theoretically, and the error was less than 5 % compared with the experimental value. [ABSTRACT FROM AUTHOR]

BackgroundInfants with hypoxic-ischemic encephalopathy are often treated with therapeutic hypothermia and high-frequency ventilation. Fluctuations in PaCO2 during therapeutic hypothermia are associated with poor neurodevelopmental outcomes. Transcutaneous CO2 monitors offer a noninvasive estimate of PaCO2 represented by transcutaneously measured partial pressure of carbon dioxide (PtcCO2 ). We aimed to assess the precision between PtcCO2 and PaCO2 values in neonates undergoing therapeutic hypothermia.MethodsThis was a retrospective chart review of 10 neonates who underwent therapeutic hypothermia requiring respiratory support over 2 y. A range of 2-27 simultaneous PtcCO2 and PaCO2 pairs of measurements per neonate were analyzed via linear mixed models and a Bland-Altman plot for multiple observations per neonate.ResultsA linear mixed-effect model demonstrated that PtcCO2 and PaCO2 (controlling for sex) were similar. The 95% CI of the mean difference ranged from -2.3 to 5.7 mm Hg (P = .41). However, precision was poor as the PtcCO2 ranged from > 18 mm Hg to < 13 mm Hg than PaCO2 values for 95% of observations.ConclusionsThe neonates' PtcCO2 was as much as 18 mm Hg higher to 13 mm Hg lower than the PaCO2 95% of the time. Transcutaneous CO2 monitoring may not be a good trending tool, nor is it appropriate for estimating PaCO2 in patients undergoing therapeutic hypothermia.

Heat stress results in significant economic losses to the poultry industry. Genetics plays an important role in chickens adapting to the warm environment. Physiological parameters such as hematochemical parameters change in response to heat stress in chickens. To explore the genetics of heat stress resilience in chickens, a genome-wide association study (GWAS) was conducted using Hy-Line Brown layer chicks subjected to either high ambient temperature or combined high temperature and Newcastle disease virus infection. Hematochemical parameters were measured during three treatment phases: acute heat stress, chronic heat stress, and chronic heat stress combined with NDV infection. Significant changes in blood parameters were recorded for 11 parameters (sodium (Na+, potassium (K+), ionized calcium (iCa2+), glucose (Glu), pH, carbon dioxide partial pressure (PCO2), oxygen partial pressure (PO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), and oxygen saturation (sO2)) across the three treatments. The GWAS revealed 39 significant SNPs (p < 0.05) for seven parameters, located on Gallus gallus chromosomes (GGA) 1, 3, 4, 6, 11, and 12. The significant genomic regions were further investigated to examine if the genes within the regions were associated with the corresponding traits under heat stress. A candidate gene list including genes in the identified genomic regions that were also differentially expressed in chicken tissues under heat stress was generated. Understanding the correlation between genetic variants and resilience to heat stress is an important step towards improving heat tolerance in poultry.

An animals preference for many chemosensory cues remains constant despite dramatic changes in the animals internal state. The mechanisms that maintain chemosensory preference across different physiological contexts remain poorly understood. We previously showed that distinct patterns of neural activity and motor output are evoked by carbon dioxide (CO2) in starved adults vs dauers of Caenorhabditis elegans, despite the two life stages displaying the same preference (attraction) for CO2. However, how the distinct CO2-evoked neural dynamics and motor patterns contribute to CO2 attraction at the two life stages remained unclear. Here, using a CO2 chemotaxis assay, we show that different interneurons are employed to drive CO2 attraction at the two life stages. We also investigate the molecular mechanisms that mediate CO2 attraction in dauers vs adults. We show that insulin signaling promotes CO2 attraction in dauers but not starved adults and that different combinations of neurotransmitters and neuropeptides are used for CO2 attraction at the two life stages. Our findings provide new insight into the distinct molecular and cellular mechanisms used by C. elegans at two different life stages to generate attractive behavioral responses to CO2.

Plants with the C4 photosynthesis pathway typically respond to climate change differently from more common C3-type plants, due to their distinct anatomical and biochemical characteristics. These different responses are expected to drive changes in global C4 and C3 vegetation distributions. However, current C4 vegetation distribution models may not predict this response as they do not capture multiple interacting factors and often lack observational constraints. Here, we used global observations of plant photosynthetic pathways, satellite remote sensing, and photosynthetic optimality theory to produce an observation-constrained global map of C4 vegetation. We find that global C4 vegetation coverage decreased from 17.7% to 17.1% of the land surface during 2001 to 2019. This was the net result of a reduction in C4 natural grass cover due to elevated CO2 favoring C3-type photosynthesis, and an increase in C4 crop cover, mainly from corn (maize) expansion. Using an emergent constraint approach, we estimated that C4 vegetation contributed 19.5% of global photosynthetic carbon assimilation, a value within the range of previous estimates (18-23%) but higher than the ensemble mean of dynamic global vegetation models (14 ± 13%; mean ± one standard deviation). Our study sheds insight on the critical and underappreciated role of C4 plants in the contemporary global carbon cycle.

The resident human skin microbiome is responsible for the production of most of the human scents that are attractive to mosquitoes. Hence, engineering the human skin microbiome to synthesize less of mosquito attractants or produce repellents could potentially reduce bites and prevent the transmission of deadly mosquito-borne pathogens. In order to further characterize the human skin volatilome, we quantified the major volatiles of 39 strains of skin commensals (Staphylococci and Corynebacterium). Importantly, to validate the behavioral activity of these volatiles, we first assessed landing behavior triggered by human skin volatiles. We demonstrated that landing behavior is gated by the presence of carbon dioxide and L-(+)-lactic acid. This is similar to the combinatorial coding triggering mosquito short range attraction. Repellency behavior to selected skin volatiles and terpenes was tested in the presence of carbon dioxide and L-(+)-lactic acid. In a 2-choice landing behavior context, the skin volatiles 2- and 3-methyl butyric acids reduced mosquito landing by 62.0-81.6% and 87.1-99.6%, respectively. Similarly, the terpene geraniol was capable of reducing mosquito landing behavior by 74.9%. We also tested the potential repellency effects of terpenes in mosquitoes at short-range using a 4-port olfactometer. In these assays, geraniol reduced mosquito attraction (69-78%) to a mixture of key human kairomones carbon dioxide, L-(+)-lactic acid, and ammonia. These findings demonstrate that carbon dioxide and L-(+)-lactic acid change the valence of other skin volatiles towards mosquito landing behavior. Moreover, this study offers candidate odorants to be targeted in a novel strategy to reduce attractants or produce repellents by the human skin microbiota that may curtail mosquito bites, and subsequent mosquito-borne disease.

Microbial electrosynthesis (MES) constitutes a bioelectrochemical process where bacteria uptake electrons extracellularly from a polarized electrode to incorporate them into their anabolic metabolism. However, the efficiency of current MES reactor designs can be lower than expected due to limitations regarding electron transfer and mass transport. One of the most promising bioreactor configurations to overcome these bottlenecks is the Microbial Electrochemical Fluidized Bed Reactor (ME-FBR). In this study, microbial CO2 fixation is investigated for the first time in a ME-FBR operated as a 3-phase reactor (solid-liquid-gas). An electroconductive carbon bed, acting as a working electrode, was fluidized with gas and polarized at different potentials (-0.6, -0.8 and -1 V vs. Ag/AgCl) so it could act as an electron donor (biocathode). Under these potentials, CO2 fixation and electron transfer were evaluated. Autotrophic electroactive microorganisms from anaerobic wastewater were enriched in a ME-FBR in the presence of 2-bromoethanosulfonic acid (BES) to inhibit the growth of methanogens. Cyclic voltammetry analysis revealed interaction between the microorganisms and the cathode. Furthermore, volatile fatty acids like propionate, formate and acetate were detected in the culture supernatant. Acetate production had a maximum rate of ca. 1 g L-1  day-1 . Planktonic cell biomass was produced under continuous culture at values as high as ca. 0.7 g L-1 dry weight. Overall, this study demonstrates the feasibility of employing a fluidized electrode with gaseous substrates and electricity as the energy source for generating biomass and carboxylic acids.

A biomimetic nanoreactor that can mimick the chloroplasts in green plants is constructed through the self-assembly of cetyltrimethylammonium bromide (CTAB) bilayer on the surface of a gold nanorod (GNR) electrocatalyst. The CTAB bilayer of the nanoreactor imitates the chloroplast membrane to allow the selective transport of CO 2 and protons to the GNR core and the GNR core functions like Rubisco enzymes in chloroplast to catalyze CO 2 reduction reaction. Consequently, selective and efficient electrochemical reduction of CO 2 to CO is achieved on the chloroplast-like nanoreactor. Schematic structures of chloroplast and our chloroplast-mimicking nanoreactor for CO 2 reduction reaction (CO 2 RR). (a) The ingenious structure of chloroplast allows the selective transport of different species through phospholipid bilayer (chloroplast membrane) and subsequent photosynthetic CO 2 fixation via Rubisco enzyme catalysis occurring in chloroplast stroma. (b) Illustrations of our biomimetic design that employ cetyltrimethylammonium bromide (CTAB) bilayer-modified gold nanorod catalysts for CO 2 RR in aqueous solution. [Display omitted] [ABSTRACT FROM AUTHOR]

Two-step redox thermochemical cycles, capable of directly converting CO 2 and H 2 O respectively into CO and H 2 , offer a promising synthesis route towards green carbon-neutral fuels. The performance of such two-step cycles depends highly on the thermodynamic properties of splitting materials, particularly the solid-state enthalpy ( Δ h solid) and entropy (Δ s solid) changes during the reduction process. Here, we report an investigation into the roles of the Δ h solid and Δ s solid. We shall show that a high Δ s solid relaxes both reduction temperature and oxygen pressure, but increases oxidant consumption. Conversely, an increase in Δ h solid enhances reduction resistance while promotes oxidation reactions. There are therefore no perfect materials, and a trade-off is needed for an optimal solution. We also defined a thermodynamic region based on Δ h solid and Δ s solid and typical operating conditions, and showed that higher values of both Δ h solid and Δ s solid provided a larger reaction space. While lower Δ h solid and negative Δ s solid may be more suitable for isothermal cycles. Our analyses also suggest future efforts in searching for splitting materials with a high Δ s solid within an appropriate range of Δ h solid (280–460 kJ/mol). [Display omitted] • Trade-off caused by solid state enthalpy and entropy is a key issue. • High solid-state enthalpy and entropy are more suitable for temperature-swing cycle. • A thermodynamic region under typical operating conditions is defined. • Solid-state entropy of different candidate materials is discussed. [ABSTRACT FROM AUTHOR]

Methane pyrolysis is emerging as an attractive clean hydrogen production method. As its commercialization proceeds, the pyrolysis of natural gas (NG) becomes pertinent. In this work, the decomposition of pure methane and a realistic NG mixture are compared experimentally and numerically. Methane and NG pyrolysis are performed between 600 and 1200 °C over a fluidized bed of carbon particles heated by microwaves. Experimentally, no conclusive difference is observed in methane conversion between methane and NG pyrolysis. Numerically, the methane conversion rate is 8.5% higher for NG at 950 °C. The difference diminishes past 950 °C, becoming 0 past 1050 °C. The simulations showed that the enhanced methane decomposition in NG pyrolysis is due to an attack on methane by radicals generated during ethane and propane decomposition. The CO 2 in our NG mixture decomposes into CO. This work validates the longstanding use of methane pyrolysis as a surrogate for NG pyrolysis. • Experimentally, no conclusive difference between NG and pure CH 4 pyrolysis. • Numerically, NG pyrolysis had at most 8.5% higher methane conversion. • Radicals from ethane decomposition attacked methane and increased methane conversion. • Inlet C 2 H 6 > 10 vol% increased the outlet CH 4 rather than aiding its decomposition. • CO 2 in the NG mixture decomposed into CO, implying non-zero GHG emissions. [ABSTRACT FROM AUTHOR]

AlH 3 is a high-capacity hydrogen storage material but is prone to explosion. Thermodynamic and structural properties of AlH 3 -nanoparticles at different CO 2 inerting systems from ignition to combustion are studied using ReaxFF-MD method. The influence of CO 2 on AlH 3 -nanoparticles ignition and combustion is investigated by comparing the changes of surface O adsorption rates, particle charge, temperature rise rates and so on. Results indicate that an increase in CO 2 is crucial for suppressing AlH 3 -nanoparticles ignition and combustion by impeding the formation of an Al-rich environment. In contrast to three stages of AlH 3 -nanoparticles combustion in pure O 2 system: surface combustion, slow temperature rise, and self-sustaining combustion, the process of CO 2 inerting system is different, with third stage is slow temperature rise at a constant rate. When CO 2 concentration reaches to 90%, the dehydrogenation rate reduces by 70.0%, the temperature rise rate decreases by 78.6%, and the ignition delay time reaches 45 ps. [Display omitted] • The mechanism of CO 2 inhibition on ignition and combustion of AHNP is clarified. • The influence of CO 2 on AHNP dehydrogenation is also elucidated. • Revealing mechanisms at the atomic scale. [ABSTRACT FROM AUTHOR]

Given that SOF materials have both inorganic and organic properties and are easy to prepare and structurally designable, this paper carries out the microbehavioral analysis and membrane design of SOF-8, SOF-9, and SOF-10 membranes for the hydrogen purification process of RMFCs. Since three materials have complementary performance characteristics for hydrogen purification, this paper focuses on the gas separation behavior of these three composite membranes using molecular dynamics simulations. Results showed that the SOF-9a+10a composite membranes could 100% block CO 2 and CO, and displayed an excellent H 2 permeability of 6.118 × 105 GPU during H 2 /CO 2 separation, which exceeded the industry standard by nearly 105 times. Additionally, the SOF-9a+8 and SOF-10a+8 composite membranes improved gas selectivity and maintained high H 2 permeability. Moreover, microdiffusion analyses revealed that the small pore sizes and irregular-shaped pore channels effectively hindered CO 2 and CO transport. Microscopic analysis shows the potential of SOF composite membranes for gas separation. [Display omitted] • SOF composite membranes can effectively improve gas selectivity. • Small pore sizes and irregular pore channels can effectively block CO 2 transport. • SOF-9a+10 can 100% intercept CO 2 and CO. • The interaction between gas and membrane affects the gas separation performance. [ABSTRACT FROM AUTHOR]

The research has examined the effects of CO 2 dilution on ignition characteristics in H 2 /air mixtures. An ignition kernel was initiated by a laser-induced plasma in H 2 /air/CO 2 mixtures with a bulk velocity of 6.5 m/s. An infrared camera was used to measure radiation intensity emitted from H 2 O and ignition probabilities. A high-speed schlieren image system was utilized to measure ignition kernel areas and ignition time. High-speed chemiluminescence was performed to examine OH* intensities. Numerical simulations were conducted using GRI 3.0 mechanisms to calculate reaction rates and laminar flame speeds. The ignition probability is highest for the undiluted mixtures and decreases with increasing the CO 2 dilution fraction at constant adiabatic temperatures. A prolonged ignition time is observed at elevated CO 2 dilution concentrations. Increasing the CO 2 mole fraction decreases the ignition kernel growth, the integrated OH* intensity, and the integrated radiation intensity for each adiabatic temperature. CO 2 reacts with H radicals and decreases the production of OH*, OH, and H 2 O. The CO 2 dilution in the H 2 /air flames significantly contributes to the reduced reaction rate and flame speed, resulting in the low ignition probability. The high ignition probability is found at the large integrated OH* intensity in all cases. The ignition probability is high at the large integrated radiation intensity under the constant adiabatic flame temperatures. The OH* intensity is a critical parameter to estimate the ignition probability in the diluted lean hydrogen flames. • The effects of CO 2 dilution on the ignition process have been studied in lean premixed H 2 /Air flames. • The ignition probability decreases with increasing the CO 2 dilution fraction. • An increase in the CO 2 dilution fraction in the mixtures reduces OH* intensity and radiation intensity emitted from H 2 O. • The presence of CO 2 in the mixtures decreases reaction rates and flame speed. [ABSTRACT FROM AUTHOR]

An N-heterocyclic stannylene :Sn(NONAd) (NONAd = [O(SiMe2NAd)2]2−, Ad = 1-adamantyl), reacts rapidly with 2,4,6-tricyclohexylphenyl azide (TCHP)N3, affording a stannaimine, (NONAd)Sn＝N(TCHP). Solutions of (NONAd)Sn＝N(TCHP) react immediately with carbon dioxide (CO2) to give a [2+2]-cycloaddition product, which, upon heating, subsequently engages in a metathesis process to give [Sn(NONAd)(μ-O)]2 and the bulky isocyanate, (TCHP)NCO. [ABSTRACT FROM AUTHOR]

The primary greenhouse gas is carbon dioxide (CO2), which also serves as an excellent C1 building block for the synthesis of heterocyclic compounds. The preparation and transformation of these structures have long been a focus in organic chemistry, making the utilization of CO2 highly advantageous. This paper reviews progress in the photochemical/electrochemical construction of heterocyclic compounds using CO2, differentiating between various reaction types and elucidating their underlying mechanisms as well as potential applications. [ABSTRACT FROM AUTHOR]

This study examines the causality of Per Capita Gross Domestic Production (PGDP), Renewable Energy Consumption (REC), and Non-Renewable Energy Consumption (NREC) on Carbon dioxide (CO2) emissions at the global level utilising data gathered from 1995 to 2020 across various countries categorised based on income levels as High, Low, Upper Middle and Lower Middle and analysed through wavelet coherence. The findings reveal both bidirectional and unidirectional causality between the variables which have evolved. Globally, a bi-directional relationship is observed with a positive correlation between PGDP and NREC and in contrast, a negative correlation with REC. Furthermore, the analysis highlights varying causalities between CO2 emissions and PGDP, except for high-income and lower-middle-income country categories, all other shows one-way causality in different periods in the short term. Moreover, CO2 and REC, show unidirectional causality throughout the short-term, exceptionally medium & long term have both unidirectional and bidirectional causalities across all country categories with a positive correlation. In contrast, CO2 and NREC depict similar causalities to REC, however, with a negative correlation. A cross-country analysis was performed between CO2 and PGDP, CO2 and REC, and CO2 and NREC using Granger causality which shows mixed relationships. The findings hold significant implications for policymakers, providing valuable insights into the trade-offs between economic growth, energy consumption, and carbon emissions. [ABSTRACT FROM AUTHOR]

ABSTRACT This study highlights the synergistic interplay between a Lewis acidic copper ion and a dissociated ligand from Cu(triNHC) complexes in the synthesis of cyclic carbonates from CO2 and epoxy compounds. The reactions were found to proceed efficiently under Cu(triNHC)‐catalyzed conditions, yielding significant quantities of cyclic carbonates across various epoxy substrates encompassing amine, sulfide, and ether functionalities. Stereochemical analyses underscore a pronounced propensity for retaining the stereochemistry of epoxy compounds in the resultant carbonates. This suggests a mechanism involving double inversion of stereochemistry during the reaction, which comprises catalyst‐mediated epoxide ring opening, subsequent CO2 addition, and carbonate ring closing. These findings align with established mechanisms for CO2 fixation reactions, shedding light on the intricate pathways underlying this catalytic process. [ABSTRACT FROM AUTHOR]

For underground hydrogen storage (UHS), hydrogen (H 2) injection and withdrawal will create a temperature difference between the wellbore and the reservoir. The thermal diffusion driven by the temperature gradient (Soret effect) may enhance the mixing between H 2 and cushion gas and affects the purity of the produced H 2. In this work, the thermal diffusion process of H 2 and CO 2 under reservoir conditions is quantitatively observed for the first time. Results show that the Soret effect drives H 2 accumulation in the high-temperature region, and is influenced by temperature, pressure, and concentration. There is significant concentration difference between the high- and low-temperature sections when minor quantities of gas are injected. From experimental observations, we obtain the Soret coefficients across different physical conditions and propose a correlation for their prediction. Additionally, while thermal diffusion slows down in porous reservoirs, the concentration difference established along the temperature gradient remains unchanged at steady state. • The thermal diffusion process (Soret effect) between H 2 and CO 2 is measured. • The Soret effect drives H 2 accumulated in the high-temperature region. • The Soret effect depends on temperature, pressure and concentration. • With the increase of H 2 injection, the Soret effect is gradually weakened. • In porous reservoirs, the Soret effect is applicable but will slow down. [ABSTRACT FROM AUTHOR]

Using Ambient Pressure X-ray Photoelectron Spectroscopy (APXPS), this study investigates the reduction behavior of iron oxides in direct reduction (DRI) and blast furnace (BF) pellets. H 2 , CO, and a H 2 –CO mixture are used as reducing agents at 650 °C. The investigation aimed to elucidate variations in the rate of reduction over time and under different conditions. Additionally, contour plots are generated to visualize the X-ray photoelectron peak intensity variations as a function of time. Furthermore, phase stability diagrams based on Fe– O –C and Fe– O –H systems are employed to enhance the understanding of reduction behavior. Results revealed that an increased gas flow rate significantly accelerated the reduction rate due to enhanced gas diffusion, while elevated pressure facilitated the reduction of wüstite to metallic iron. Notably, the DRI pellet achieves around 90% metallization degree reduction with hydrogen, but the introduction of carbon monoxide into the reducing gas prevented the reduction of the DRI pellet. In the case of BF pellet reduction, approximately 20% metallization degree is observed using H 2 –CO (50:50), yet subsequent reoxidation of the reduced iron to wüstite and magnetite occurred. Further investigation identified a significant increase in the partial pressure of H 2 O and CO 2 , particularly within the surface porosities, as the underlying cause of this reoxidation phenomenon. • APXPS used to study iron oxide surface reduction in DRI and BF pellets. • Increased gas flow rate and pressure accelerated reduction rate. • DRI pellet achieved ∼90% metallization with H 2 , however, the value was ∼9% for BF. • BF pellet attained ∼20% metallization with H 2 –CO, while DRI showed no reduction. • Using CO–H 2 , reoxidation observed in BF due to a rise in H 2 O–CO 2 partial pressure. [ABSTRACT FROM AUTHOR]

A hierarchical structure alumina with high surface area was synthesized using a sol-gel method assisted by propylene oxide (PO), which was subsequently converted into alumina exhibiting different transitional phases (γ, δ, θ) through varying calcination temperatures. These aluminas were employed as substrates for the active copper phase in the RWGS catalyst, facilitating a systematic exploration of how the alumina phase influences catalyst performance. The characterized catalysts underwent assessments using techniques such as N 2 adsorption-desorption, XRD, H 2 -TPR, CO 2 -TPD, FESEM, and HRTEM. An examination of the impact of copper loading (ranging from 5.0 to 20.0 wt%) in the Cu/γ-Al 2 O 3 catalyst on RWGS performance revealed that the catalyst containing 15.0 wt% Cu exhibited the highest CO 2 conversion rate, achieving 8% at 300 °C under a 1CO 2 :1H 2 ratio at atmospheric pressure. This specific catalyst demonstrated 100% selectivity for CO. Evaluating the extended stability of Cu catalysts supported by γ-, δ-, and θ-Al 2 O 3 phases, all loaded with the same amount of Cu (15.0 wt%), was carried out at 450 °C. The δ- and θ-Al 2 O 3 -supported catalysts were able to maintain approximately 100% of their initial catalytic activities after 72 h, whereas the activity of the catalyst supported by γ-Al 2 O 3 decreased. The examination of the crystalline phases of the catalyst support and stability testing demonstrated the significant impact of porosity on mass transfer and the diffusion processes of reactants and production on the structure of the catalyst. This study revealed how adjusting the macropore size and porosity within various crystalline phases can optimize the filling degree and achieve an ideal balance between reaction and mass transfer rates. [Display omitted] • Catalyst support with the highest surface area was prepared via a sol-gel method. • Effect of hierarchical alumina as catalyst support was investigated in RWGS reaction. • 15 wt% Cu/γ-Al 2 O 3 catalyst exhibited the highest CO 2 conversion of 8% at 300 °C. • CO selectivity was 100% over 15 wt% Cu/γ-, δ-, and θ-Al 2 O 3 catalysts. [ABSTRACT FROM AUTHOR]

Chemical looping reforming of CH 4 coupled with CO 2 reduction stands out as a promising method for the syngas production. In this process, it is significant to design the oxygen carrier with high reactivity and stability. In this work, a highly efficient oxygen carrier is obtained by physically mixing Metal-modified ZSM-5 with LaFe 0.85 Ni 0.15 O 3 (LFN). The physical and chemical properties of the oxygen carriers are characterized by XRD, Raman, XPS, BET, TEM, NH 3 -TPD, CO 2 -TPD and CH 4 -TPD techniques. It is noted that mesoporous structures are formed over the Ni modified ZSM-5, due to that part of Ni elements replace Al in the silicaluminate framework. The structure change of the ZSM-5 promotes the gas adsorption capacity. CH 4 and CO 2 cannot be adsorbed on the surface of ZSM-5, while Ni-modified ZSM-5 enhances the adsorption capacity for CO 2 to a large degree. Moreover, Ni species are acted as active sites to facilitate the activation of CH 4 and CO 2 during the redox process. The aggregation-redispersion of Ni particles during the reduction-oxidation process inhibits the deactivation of Ni particles, which improves the stability of the oxygen carrier. Among all the obtained samples, LFN/10 wt% Ni-ZSM-5 exhibits the highest yields of syngas (8.38 mmol g−1) and CO (2.42 mmol g−1). [Display omitted] • Modifying ZSM-5 with Ni changed the pore structures and acid sites. • Ni-modified ZSM-5 promoted the adsorption capacity towards CO 2. • The activation of CH 4 and CO 2 could be improved over Ni-modified ZSM-5. • Ni particles maintained active by aggregation-redispersion under redox atmospheres. • LFN/10 wt% Ni-ZSM-5 exhibited high stability either in the activity or structure. [ABSTRACT FROM AUTHOR]

Defect engineering has been widely applied in the field of photocatalysis, and defects can be used to modify the surface structure and photoelectric properties of catalysts so as to achieve the purpose of regulating the activity and stability of catalysts. However, design of a highly efficient photocatalyst with abundant defects remains a challenging task in current research. Therefore, in this study, graphitic carbon nitride (g-C 3 N 4) with abundant three-coordinated nitrogen (N 3C) vacancies and pore structures was obtained using a facile hydrothermal method with the assistance of glycerol. Under visible light (λ > 420 nm) irradiation, the 50CN (volume ratio of glycerol/water is 50/10) catalyst exhibits a superior CO release rate (4.18 μmol g−1 h−1), which is 12.06 times higher than the reference GCN (0.32 μmol g−1 h−1), and the corresponding apparent quantum yields (AQY) of 50CN is 0.24 %, which is significantly higher than that of GCN (0.045 %). Successful introduction of N 3C vacancies is conducive to broaden light response range of the catalyst, enhancing the separation and migration efficiency of photogenerated charges, and providing more adsorption active sites to promote the adsorption and activation of CO 2 molecules, thus effectively boosting photocatalytic CO 2 reduction activity. In addition, the N 3C vacancies can effectively lower the CO 2 activation energy barrier and reduce the energy consumption required for the reaction. This work offers valuable new insights into defect engineering in g-C 3 N 4 for the development of high-performance photocatalysts for CO 2 reduction. [ABSTRACT FROM AUTHOR]

Noble gas xenon (Xe) is an excellent anesthetic gas, but its rarity, high cost and constrained production prohibits wide use in medicine. Here, we have developed a closed‐circuit anesthetic Xe recovery and reusage process with highly effective CO2‐specific adsorbent CUPMOF‐5 that is promising to solve the anesthetic Xe supply problem. CUPMOF‐5 possesses spacious cage cavities interconnected in four directions by confinement throat apertures of ~3.4 Å, which makes it an ideal molecular sieving of CO2 from Xe, O2, N2 with the benchmark selectivity and high uptake capacity of CO2. In situ single‐crystal X‐ray diffraction (SCXRD) and computational simulation solidly revealed the vital sieving role of the confined throat and the sorbent‐sorbate induced‐fit strengthening binding interaction to CO2. CUPMOF‐5 can remove 5 % CO2 even from actual moist exhaled anesthetic gases, and achieves the highest Xe recovery rate (99.8 %) so far, as verified by breakthrough experiments. This endows CUPMOF‐5 great potential for the on‐line CO2 removal and Xe recovery from anesthetic closed‐circuits. [ABSTRACT FROM AUTHOR]

The purpose of the analysis was to evaluate if 10 mg naloxone, administered intramuscularly, could reverse or prevent opioid‐induced respiratory depression (OIRD), including OIRD associated with the administration of lethal doses of high‐potency opioids. A naloxone population pharmacokinetic (PK) model was generated using data from two naloxone auto‐injector (NAI) clinical PK studies. Mechanistic OIRD PK‐pharmacodynamic (PD) models were constructed using published data for buprenorphine, morphine, and fentanyl. Due to the lack of published carfentanil data in humans, interspecies allometric scaling methods were used to predict carfentanil PK parameters in humans. A PD model of a combined effect‐compartment and receptor kinetics model with a linear relationship between ventilation and carbon dioxide was used to predict the respiratory depression induced by carfentanil. Model‐based simulations were performed using the naloxone population PK model and the constructed mechanistic OIRD PK–PD models. Changes in ventilation were assessed after opioid exposure and treatment with 2 mg naloxone or one or two doses of 10 mg naloxone. A higher percentage of subjects recovered back to the rescue ventilation thresholds and/or had a faster recovery to 40% or 70% of baseline ventilation with 10 mg compared with 2 mg naloxone. A second dose of 10 mg naloxone, administered 60 min post‐opioid exposure, expedited recovery to 85% of baseline ventilation and delayed time to renarcotization compared with a single dose. In addition, when 10 mg naloxone was administered at 5, 15, 30, or 60 min before fentanyl or carfentanil exposure, rapid and profound OIRD was prevented. [ABSTRACT FROM AUTHOR]

The sulfur over calcium ratio (S/Ca) in foraminiferal shells was recently proposed as a new and independent proxy for reconstructing marine inorganic carbon chemistry. This new approach assumes that sulfur is incorporated into CaCO 3 predominantly in the form of sulfate (SO 4 2−) through lattice substitution for carbonate ions (CO 3 2–), and that S/Ca thus reflects seawater [CO 3 2–]. Although foraminiferal growth experiments validated this approach, field studies showed controversial results suggesting that the potential impact of [CO 3 2–] may be overwritten by one or more parameters. Hence, to better understand the inorganic processes involved, we here investigate S/Ca values in inorganically precipitated CaCO 3 (S/Ca (cc)) grown in solutions of CaCl 2 − Na 2 CO 3 − Na 2 SO 4 − B(OH) 3 − MgCl 2. Experimental results indicate the dependence of sulfate partitioning in CaCO 3 on the carbon chemistry via changing pH and suggest that faster precipitation rates increase the partition coefficient for sulfur. The S/Ca ratios of our inorganic calcite samples show positive correlation with modelled [CaSO 4 0] (aq) , but not with the concentration of free SO 4 2− ions. This challenges the traditional model for sulfate incorporation in calcite and implies that the uptake of sulfate potentially occurs via ion-ion pairs rather than being incorporated as single anions. Based on the [Ca2+] dependence via speciation, we here suggest a critical evaluation of this potential proxy. As sulfate complexation seems to control sulfate uptake in inorganic calcite, application as a proxy using foraminiferal calcite may be limited to periods for which seawater chemistry is well-constrained. As foraminiferal calcite growth is modulated by inward Ca2+ flow to the site of calcification coupled to outward H+ pumping, sulfate incorporation as CaSO 4 0 ion-pair in the foraminifer's shell also provides a mechanistic link for the observed relationship between S/Ca (cc) and [CO 3 2–]. [ABSTRACT FROM AUTHOR]

Abiotic synthesis of CH 4 in seafloor hydrothermal fluids is generally assumed to occur via heterogeneous reactions on mineral surfaces. Stepwise homogeneous reduction of CO 2 has, however, been suggested as an alternative (but sluggish) abiotic pathway to CH 4 , potentially via metastable species of intermediate oxidation states. In this study, we examine the effect of two temperature-dependent methylated species − methanol (CH 3 OH) and methanethiol (CH 3 SH), on homogeneous CH 4 formation rates under long-term simulated hydrothermal conditions. Aqueous solutions containing formic acid (H13COOH, generating 13CO 2 and H 2) were heated with and without H 2 S at 300–325 °C (35 MPa) in a flexible Au reaction cell over several years without added minerals. Substantial 13C-labeled CH 4 and CH 3 OH production from 13CO 2 was observed over 4.3 yr, with aqueous CH 4 formation varying with CH 3 OH abundance – a strong function of dissolved H 2 abundance and, inversely, temperature. CH 4 production was slower at 325 °C with lower CH 3 OH concentrations (in equilibrium with CO 2 and H 2), and faster at 300 °C, accompanying an equilibrium-controlled increase in CH 3 OH. Fastest CH 4 production occurred at 300 °C following injection of H 2 S and H13COOH, which led to rapid formation (<4 days) of 13C-labeled CH 3 SH that subsequently decomposed over a further 0.8 yr, partly to 13CH 4. Heating aqueous 13CH 4 to 345–387 °C (33–35 MPa) in the presence of an oxidizing hematite-magnetite-pyrite assemblage, however, yielded no detectable CH 3 SH after 112 days indicating the reverse reaction is inhibited under favorable thermodynamics. Neither direct reduction of CO 2 to CH 3 SH nor CO 2 -CH 3 SH equilibrium were evident at 300 °C, implying CH 3 SH and CH 3 OH play disparate roles in homogeneous carbon reduction to CH 4. Longer chain hydrocarbons (C 2+ alkanes) remained low throughout the experiments. CH 3 SH abundances previously reported in vent fluids at the Von Damm hydrothermal field correlate strongly with demonstrably abiotic HCOOH there, suggesting the reduction of HCOOH to CH 3 SH observed in this study may also occur in vent fluids. A comparison of mineral-free 13CH 4 production rates reported here with 13CO 2 reduction experiments involving minerals indicates that homogeneous reduction proceeds at similar rates to purported transition metal-catalyzed 13CH 4 production, and is generally faster than experiments with either added olivine or ultramafic rock. Previous claims of substantial mineral-catalyzed abiogenic CH 4 production are therefore not supported by our study. Homogeneous CO 2 reduction may be a significant source of methylated compounds and CH 4 in hydrothermal fluids characterized by decadal (or longer) residence times, such as those found in mineral-hosted inclusions or occluded fractures in igneous basement, requiring only moderate temperatures and abundant H 2 to proceed. [ABSTRACT FROM AUTHOR]

We integrated a pair of donor–acceptor photothermal units, a Lewis acidic site, and a nucleophilic catalytic site into a multi-component metal–organic framework, resulting in an efficient photothermal catalytic system for the conversion of CO2 to cyclic carbonates. [ABSTRACT FROM AUTHOR]

• CaCl 2 is an additive suitable for pyrometallurgical recovery of spent LIBs. • CaCl 2 has good chlorination ability and slag optimization ability. • SiO 2 and CO 2 in the system contribute to the increase in HCl yield. The difficulty of separating Li during pyrometallurgical smelting of spent lithium-ion batteries (LIBs) has limited the development of pyrometallurgical processes. Chlorination enables the conversion of Li from spent LIBs to the gas phase during the smelting process. In this paper, the effects of four solid chlorinating agents (KCl, NaCl, CaCl 2 and MgCl 2) on Li volatilization and metal (Co, Cu, Ni and Fe) recovery were investigated. The four solid chlorinating agents were systematically compared in terms of the direct chlorination capacities, indirect chlorination capacities, alloy physical losses and chemical losses in the slag. CaCl 2 was better suited for use as a solid chlorinating agent to promote Li volatilization due to its excellent results in these indexes. The temperature required for the release of HCl from MgCl 2 , facilitated by CO 2 and SiO 2 , was lower than 500 °C. The prematurely released HCl failed to participate in the chlorination reaction. This resulted in approximately 12 % less Li volatilization when MgCl 2 was used as a chlorinating agent compared to when CaCl 2 was used. In addition, the use of KCl as a chlorinating agent decreased the chemical dissolution loss of alloys in the slag. The performance of NaCl was mediocre. Finally, based on evaluations of the four indexes, recommendations for the selection and optimization of solid chlorinating agents were provided. [ABSTRACT FROM AUTHOR]

[Display omitted] The Sudokwon landfill (SL) in the Seoul metropolitan area, South Korea, is among the world's largest landfills, striving to curtail landfill gas (LFG) emissions and achieve carbon neutrality by 2050. Since 2005, the SL Management Corporation (SLC) has measured LFG emissions (i.e., methane (CH 4) and carbon dioxide (CO 2)) using a dynamic flux chamber proposed by the US EPA. However, uncertainty prevails in validating the reduction of LFG emissions due to the limited spatiotemporal data coverage. In 2020, an eddy covariance (EC) system was installed to enhance measurements, revealing highly fluctuating LFG emissions driven by waste layer LFG production, LFG collection, and atmospheric pressure changes. During the study period, the annual CH 4 emission increased slightly from 465.0 ± 4.2 to 485.5 ± 6.4 g C m−2, while that of CO 2 decreased by 2/3 (from 408.7 ± 16.5 to 270.6 ± 18.8 g C m−2), primarily due to the doubled CO 2 uptake by the vegetated topsoil. Our first long-term (March 2020 to February 2022) quasi-continuous monitoring using EC (with a gap-filling and partitioning technique based on Random Forest) emphasizes the difficulty of temporal upscaling of discontinuously observed surface emissions to quantify the LFG inventory and the need for continuous observations or suitable proxies (e.g., atmospheric CH 4 concentration). [ABSTRACT FROM AUTHOR]

By embedding Na ions into graphitic carbon nitride, the directional migration of photo-generated electrons towards Na sites is achieved, thereby creating additional reaction sites. Moreover, the electron-rich Na sites enhance the adsorption and activation of CO 2. Consequently, the photocatalytic performance is improved to some extent. [Display omitted] The depressed directional separation of photogenerated carriers and weak CO 2 adsorption/activation activity are the main factors hampering the development of artificial photosynthesis. Herein, Na ions are embedded in graphitic carbon nitride (g-C 3 N 4) to achieve directional migration of the photogenerated electrons to Na sites, while the electron-rich Na sites enhance CO 2 adsorption and activation. Na/g-C 3 N 4 (NaCN) shows improved photocatalytic reduction activity of CO 2 to CO and CH 4 , and under simulated sunlight irradiation, the CO yield of NaCN synthesized by embedding Na at 550°C (NaCN-550) is 371.2 μmol g−1 h−1, which is 58.9 times more than that of the monomer g-C 3 N 4. By means of theoretical calculations and experiments including in situ fourier transform infrared spectroscopy, the mechanism is investigated. This strategy which improves carrier separation and reduces the energy barrier at the same time is important to the development of artificial photosynthesis. [ABSTRACT FROM AUTHOR]

The production of multi‐carbon compounds through CO2 photoreduction (CO2PR) holds great promise but faces challenges due to high kinetic barriers and the sluggish process of C‐C coupling. Overcoming these obstacles requires fine engineering of active sites. In this study, Ni active sites are engineered through the synergistic effect of metal‐oxo cluster (Mo7O246−) and hydroxyl vacancy (VOH). In contrast to the Ni sites unmodified with Mo7O246− and VOH, which are unable to produce multi‐carbon products, the constructed electron‐enriched Ni active sites exhibit an impressive selectivity of up to 43.02% and a high yield rate of 246.70 µmol g−1 h−1 for C2H6, which represent one of the best results for CO2PR to C2H6. Through a comprehensive investigation involving operando experiments and theoretical simulations, hydroxyl vacancy and the formed Mo─O─Ni bonds is demonstrated due to the filling of hydroxyl vacancies with oxygen atoms from Mo7O246− synergistically constructed electron‐rich Ni sites. Such Ni sites efficiently catalyze CO2 conversion to C2H6 by enhancing the adsorption of *CO, promoting subsequent hydrogenation, and enabling low energy barriers for CO2 hydrogenation to *OCOH and the coupling of *CH3 intermediates. This study provides deeper insights into the photocatalytic process, highlighting the significance of tailored active sites for efficient CO2 conversion. [ABSTRACT FROM AUTHOR]

Summary This study examined the impact of CO2 on the quality of onions stored at 23 °C for 6 weeks, focussing on bioactive compounds, antioxidant capacity, individual anthocyanins, flavonoids and anthocyanin biosynthesis during the storage period. The findings revealed that a 20% CO2 treatment was markedly more effective than the control in maintaining higher levels of phenolics, flavonoids, flavanols and anthocyanins. Moreover, the 20% CO2 treatment preserved significantly higher quantities of individual anthocyanins and flavonoids compared to the control. Throughout storage, the 20% CO2 treatment significantly boosted the activity of enzymes related to anthocyanin biosynthesis and sucrose metabolism relative to the control groups. In summary, the innovation of this study lies in the use of CO2 to maximise anthocyanin and flavonoid content in stored onions, which are usually diminished by extended storage at room temperature. This method could help extend the shelf life of onions while preserving their quality attributes. [ABSTRACT FROM AUTHOR]

Two new neodymium-based metal–organic frameworks, JMS-10 and JMS-11, were synthesised using a 2,2′-bipypridine-5,5′-dicarboxylic acid (bpdc) linker. Both MOFs were solvothermally synthesised in DMF under different conditions. JMS-10 was synthesised at 120 °C while JMS-11 was synthesised at 100 °C in the presence of a modulator. Both the MOFs possessed very similar crystallographic parameters but were found to be structurally diverse. Their structures were built by secondary building units (SBUs) made up of carboxylates binding in sets of four and two to the straight rod, thus forming two types of alternating nodes that are 6- and 4-connected. Both JMS-10 and JMS-11 were functionalized using the ruthenium p-cymene complex. The functionalized MOFs were applied in the photocatalytic reduction of carbon dioxide to syngas where they produced both hydrogen and carbon monoxide (CO : H2) in the ratio of 1 : 2. The amount of CO to H2 produced varied depending on the additives used in the reaction medium, highlighting the importance of water, triethanolamine and acetonitrile in tuning the syngas ratio for different industrial applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Sulfur dioxide is serious ultimatum to human health as well as environment, while carbon dioxide is viewed as one of the primary drivers of the worldwide temperature alteration. Therefore, capturing of these gases is a dynamic research subject attracting much consideration from scientists. Herein, we report synthesis of a series of Co‐ZIF and bimetallic M‐Co‐ZIF adsorbents and application for room temperature adsorption of SO2 and CO2. In this work, the breakthrough curves for the adsorption of sulfur dioxide and carbon dioxide on Co‐ZIF and M‐Co‐ZIF were obtained experimentally and theoretically using a laboratory‐scale fixed bed column at room temperature. In this work, the adsorption capacities and breakthrough points for modified bimetallic M‐Co‐ZIF were found to be relatively higher than parent Co‐ZIF. Notably, a high SO2 uptake capacity of 7.1 mmol/g for Zr‐Co‐ZIF and high CO2 uptake capacity of 69.9 mmol/g for Ni‐Co‐ZIF were achieved. The parent cobalt and bimetallic ZIF materials were characterized by XRD, FTIR, SEM, and nitrogen physisorption. The XRD results confirm the formation of pure phase highly crystalline ZIF materials while BET analysis suggests high surface area of prepared adsorbents. Finally, the results of dynamic adsorption combined with characterization show great potential for preparation of bimetallic ZIF adsorbents for effective SO2 and CO2 adsorption. [ABSTRACT FROM AUTHOR]