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Carbonate minerals are globally distributed on the modern and ancient Earth and are abundant in terrestrial and marine depositional environments. Fluid inclusions hosted by calcite retain primary signatures of the source fluid geochemistry at the time of mineral formation (i.e., pCO2) and can be used to reconstruct paleoenvironments. Confocal laser Raman spectroscopy provides a quick, nondestructive approach to measuring the constituents of fluid inclusions in carbonates and is a reliable method for qualitatively determining composition in both the aqueous and gas phases. Here, we demonstrate a method for accurately quantifying bicarbonate and carbonate ion concentrations (down to 20 mM) and pH (7–11) from calcite fluid inclusions using confocal Raman spectroscopy. Instrument calibrations for carbonate (CO32–) and bicarbonate (HCO3–) concentrations and pH were performed using stock solutions. We show that the calcite host mineral does not affect the accurate quantification of carbonate solution concentrations and that these parameters can be used to estimate the pH and pCO2 of a solution entrapped within a fluid inclusion. We apply the technique to Icelandic spar calcite and find a [CO32–] = 0.11, [HCO3–] = 0.17, pH = 10.1, and CO2 parts per million = 2217. The presence of gaseous Raman bands for CO2, CH4, and H2S suggests that the mineral precipitated in a reducing environment. [ABSTRACT FROM AUTHOR]

In the next century, negative effects, such as an increase in temperature level, rise in sea level and decrease in forests and agricultural areas, are expected as a result of the harmful effects of global warming. The construction industry is among the main actors of global warming. Cement, the most used building material of the construction industry, is responsible for approximately 8% of CO2 emissions worldwide. Reducing the amount of cement production and using alternative materials and wastes can contribute to reducing CO2 emissions in the production of building materials. In this study, Alkali-Activated Mortar (AAM) mixtures which contain Ground Granulated Blast Furnace Slag (GGBFS) and Fly Ash (FA) were prepared. Recycled Asphalt Waste (RAW) is reduced to 0–4 mm size in order to use as fine aggregate in AAM mixes. Three different activation temperatures (40 °C, 80 °C and 120 °C) were applied for 18 h in order to examine the effect of activation temperature on the prepared AAM samples. After the application of activation temperature, the samples were kept in the standard curing pool for 7 and 28 days. After curing, physical and mechanical experiments were carried out on AAM samples. Water absorption and porosity, compressive strength and electrical resistivity tests were performed on the hardened samples. In addition, the acid effect on the samples was investigated comparatively with the changes in mechanical and physical properties. As a result, the study, in which high-strength mortar mixtures were obtained, shows promising results in terms of sustainable environmentalism. The compressive strength value of 45.74 MPa was found in the mortar mixtures produced using RAW. In addition, it was concluded that the optimum activation temperature is an important parameter of compressive strength and acid resistance. [ABSTRACT FROM AUTHOR]

Global climate change has already brought noticeable alterations to multiple regions of our planet, including increased CO2 concentrations and changes in temperature. Several important steps of plant growth and development, such as embryogenesis, can be affected by such environmental changes; for instance, they affect how stored nutrients are used during early stages of seed germination during the transition from heterotrophic to autotrophic metabolism—a critical period for the seedling's survival. In this article, we briefly describe relevant processes that occur during embryo maturation and account for nutrient accumulation, which are sensitive to environmental change. Most of the nutrients stored in the seed during its development—including carbohydrates, lipids, and proteins, depending on the species—accumulate during the seed maturation stage. It is also known that iron, a key micronutrient for various electron transfer processes in plant cells, accumulates during embryo maturation. The existing literature indicates that climate change can not only affect the quality of the seed, in terms of total nutritional content, but also affect seed production. We discuss the potential effects of temperature and CO2 increases from an embryo-autonomous point of view, in an attempt to separate the effects on the parent plant from those on the embryo. [ABSTRACT FROM AUTHOR]

Objective: To report a single-centre experience in the endoscopic carbon dioxide laser-assisted approach to glomus tympanicum tumours. Methods: A retrospective case review was conducted of patients diagnosed with class A1 to B1 glomus tympanicum tumours who underwent exclusive transcanal endoscopic carbon dioxide laser surgery. Results: Seven patients fulfilled the inclusion criteria. All patients (100 per cent) were women, with a mean age of 65.4 years (standard deviation, 13.6). There were five A2 tumours, one A1 tumour and one B1 tumour. One patient presented with a delayed tympanic membrane perforation needing myringoplasty on follow up. There were no substantial post-operative complications. The mean hospitalisation time was 9.5 hours (standard deviation, 9.8). The mean follow-up period was 32.7 months (standard deviation, 13.1), with all cases having resolution of pulsatile tinnitus and no tumour recurrence. Conclusion: The study provides further evidence on the safety and efficacy of endoscopic carbon dioxide laser surgery as a minimally invasive technique for treating early-stage glomus tympanicum tumours. [ABSTRACT FROM AUTHOR]

A set of empirical rovibrational energy levels, obtained through the MARVEL (measured active rotational‐vibrational energy levels) procedure, is presented for the 13C 16O 2 isotopologue of carbon dioxide. This procedure begins with the collection and analysis of experimental rovibrational transitions from the literature, allowing for a comprehensive review of the literature on the high‐resolution spectroscopy of 13C 16O 2, which is also presented. A total of 60 sources out of more than 750 checked provided 14,101 uniquely measured and assigned rovibrational transitions in the wavenumber range of 579–13,735 cm −1. This is followed by a weighted least‐squares refinement yielding the energy levels of the states involved in the measured transitions. Altogether 6318 empirical rovibrational energies have been determined for 13C 16O 2. Finally, estimates have been given for the uncertainties of the empirical energies, based on the experimental uncertainties of the transitions. The detailed analysis of the lines and the spectroscopic network built from them, as well as the uncertainty estimates, all serve to pinpoint possible errors in the experimental data, such as typos, misassignment of quantum numbers, and misidentifications. Errors found in the literature data were corrected before including them in the final MARVEL dataset and analysis. [ABSTRACT FROM AUTHOR]

This research utilizes a bootstrap rolling-window (BRW) causality test to explore the causal interrelationship between nuclear energy consumption (NUC) and carbon dioxide emissions (CO2) in 6 developed countries from 1980 to 2020. When there are structural shifts in the full-sample time series, empirical research exploring causality between two-time series generates erroneous conclusions. On the other hand, the BRW method allows researchers to find potential time-varying causality between time series using sub-sample data. The outcomes of the BRW causality test disclosed the following results: (i) a unidirectional negative causality from NUC to CO2 without feedback was found for Japan; (ii) a negative causality at sup-sample periods from NUC to CO2 surfaced at the sub-sample period while a positive causality surfaced from NUC to CO2 in sub-sample period for the United States of America (USA) and France; (iii) a negative feedback causality between NUC and CO2 was found For Canada; (iv) a positive unidirectional causality surfaced from NUC to CO2 was found for Germany, which implies that consumption of NUC worsens the environment in the sub-sampled period. The results may have policy consequences for the selected developed countries regarding NUC and CO2 nexus. [ABSTRACT FROM AUTHOR]

Background and Aims Kelp forests are increasingly considered blue carbon habitats for ocean-based biological carbon dioxide removal, but knowledge gaps remain in our understanding of their carbon cycle. Of particular interest is the remineralization of detritus, which can remain photosynthetically active. Here, we study a widespread, thermotolerant kelp (Ecklonia radiata) to explore detrital photosynthesis as a mechanism underlying temperature and light as two key drivers of remineralization. Methods We used meta-analysis to constrain the thermal optimum (T opt) of E. radiata. Temperature and light were subsequently controlled over a 119-day ex situ decomposition experiment. Flow-through experimental tanks were kept in darkness at 15 °C or under a subcompensating maximal irradiance of 8 µmol photons m−2 s−1 at 15, 20 or 25 °C. Photosynthesis of laterals (analogues to leaves) was estimated using closed-chamber oxygen evolution in darkness and under a saturating irradiance of 420 µmol photons m−2 s−1. Key Results T opt of E. radiata is 18 °C across performance variables (photosynthesis, growth, abundance, size, mass and fertility), life stages (gametophyte and sporophyte) and populations. Our models predict that a temperature of >15 °C reduces the potential for E. radiata detritus to be photosynthetically viable, hence detrital T opt ≤ 15 °C. Detritus is viable under subcompensating irradiance, where it performs better than in darkness. Comparison of net and gross photosynthesis indicates that elevated temperature primarily decreases detrital photosynthesis, whereas darkness primarily increases detrital respiration compared with optimal experimental conditions, in which detrital photosynthesis can persist for ≥119 days. Conclusions T opt of kelp detritus is ≥3 °C colder than that of the intact plant. Given that E. radiata is one of the most temperature-tolerant kelps, this suggests that photosynthesis is generally more thermosensitive in the detrital phase, which partly explains the enhancing effect of temperature on remineralization. In contrast to darkness, even subcompensating irradiance maintains detrital viability, elucidating the accelerating effect of depth and its concomitant light reduction on remineralization to some extent. Detrital photosynthesis is a meaningful mechanism underlying at least two drivers of remineralization, even below the photoenvironment inhabited by the attached alga. [ABSTRACT FROM AUTHOR]

Foams have been successfully implemented to overcome the challenges associated with gas-enhanced oil recovery (EOR) over time. Generally, the foam helps to increase the viscosity of the injected gas, which in turn improves the effectiveness of EOR. However, this technology has rarely been applied in the oilfield due to technological and economical limitations. It is widely considered that nanoparticles may be added to foam to enhance its performance in harsh reservoir conditions to overcome some of these limitations. In this study, we employed high-pressure microscopy (HPM) as an advanced technique to examine the stability of N 2 and C O 2 foams at reservoir conditions, both with and without nanoparticles. The experiments were conducted under vapour and supercritical conditions. Our results indicated that foams produced at 80% quality were more stable than foams produced at 50% quality because the bubble size was significantly smaller and the bubble count was higher. Additionally, foams under supercritical conditions (sc) exhibited greater stability than foams under vapour conditions. This is because at supercritical conditions, the high density of gases helps to strengthen the foam lamella by enhancing the intermolecular contacts between the gas and the hydrophobic part of the liquid phase. Furthermore, core flooding studies were performed to investigate their effect on oil displacement and mobility control in both real and artificial core samples. Rather than focusing on precise quantitative results, our objective was to assess the effect of foams on oil recovery qualitatively. The results indicated that foam injection could significantly increase displacement efficiency, as foam injection raised total displacement efficiency from an initial 48.9% to 89.7% in the artificial core sample. Similarly, in the real core model, C O 2 foam injection was implemented as a tertiary recovery method, and a recovery factor of 28.91% was obtained. These findings highlight the potential benefits of foams for EOR purposes and their ability to mitigate early gas breakthrough, which was observed after injecting approximately 0.14 PV during s c C O 2 injection. [ABSTRACT FROM AUTHOR]

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In order to reduce development costs and time-to market, 1D and 3D CFD tools can support engine design providing reliable estimations of the tailpipe emissions. In particular, 3D-CFD in-cylinder simulations can evaluate formation of both soot and gaseous pollutants inside the combustion chamber. The main issue in such kind of simulations is the validation against experimental findings. In fact, the complexity of the emission measurements does not allow a straightforward one-to-one comparison between numerical and experimental results. Therefore the present paper aims at providing, on the one hand, a robust numerical framework for both gaseous and solid emissions, on the other hand a dedicated post-processing for a fair comparison between simulations and experiments. From a numerical standpoint, a simplified approach is dedicated to gaseous emissions, while a more detailed one is reserved to soot modeling. The latter is based on the Sectional Method, whose reaction rates are tabulated following 0D chemical kinetic simulations of a purposely designed surrogate in a constant pressure reactor. Simulations and experiments proposed in the present analysis are referred to a high-performance turbocharged direct-injection spark-ignition engine operated at part-load and low rpms. On equal performance, revving speed and mean mixture quality, different injection timings are investigated. The developed numerical approach and post-processing ensure a good agreement between simulations and experiments. [ABSTRACT FROM AUTHOR]

In a climate change scenario and under a growing interest in Precision Agriculture, it is more and more important to map and record seasonal trends of the respiration of cropland and natural surfaces. Ground-level sensors to be placed in the field or integrated into autonomous vehicles are of growing interest. In this scope, a low-power IoT-compliant device for measurement of multiple surface C O 2 and W V concentrations have been designed and developed. The device is described and tested under controlled and field conditions, showing ready and easy access to collected values typical of a cloud-computing-based approach. The device proved to be usable in indoor and open-air environments for a long time, and the sensors were arranged in multiple configurations to evaluate simultaneous concentrations and flows, while the low-cost, low-power (LP IoT-compliant) design is achieved by a specific design of the printed circuit board and a firmware code fitting the characteristics of the controller. [ABSTRACT FROM AUTHOR]

In this work, we used three gases (CO2, N2 and normal hexane) for diffusivity measurements in Acrylonitrile butadiene styrene (ABS). We proposed a diffusion model that the diffusion coefficients of each gas in ABS could be estimated from the specific volume of ABS/gas mixture and chemical potential of gas in ABS. The solubility and diffusivity of three gases into ABS were determined by a magnetic suspension balance. The results showed that the solubility and diffusivity of three gases increased with increasing of pressure. Also it was determined that N2 has a lowest solubility and the highest diffusivity in ABS in all temperature and pressure ranges. It was shown that there was a suitable overlapping between the experimental and predicted values from the proposed model, in which the proposed model could successfully estimate the diffusion coefficient of mentioned gases in ABS in all temperature and pressure ranges. [ABSTRACT FROM AUTHOR]

Polymer foams offer high sustainable performance in terms of their lightweight potential, insulation and high specific mechanical properties. The foaming of polymers depends on the properties of gas-laden solids or liquids. For foaming in the solid state, the foaming temperature must be higher than the glass transition temperature of the saturated polymer system. Moreover, the knowledge of sorption conditions and thermal properties is crucial for foam formation. In this study, the correlation between the glass transition temperature and the sorption conditions was investigated. This comparison was made by determining the sorption behavior for different pressure levels and the corresponding glass transition temperature using a high-pressure differential scanning calorimetry. The time, pressure and CO2 content were varied. For the first time, the Chow model could be verified for PLA with a coordination number of 3. [ABSTRACT FROM AUTHOR]

Globally, peatlands have been recognized as important carbon sinks while only covering approximately 3% of the earth's land surface. Root exudates are known key drivers of C cycling in soils and rhizosphere priming effects have been studied extensively in terrestrial ecosystems. Their role for decomposition of peat still remains unclear, as little research about their fate and potential priming effects in peat exists. In this study, we aimed to evaluate pathways of root exudates and their short-term priming effects by daily determination of stable carbon isotope fluxes of C O 2 and C H 4 . As the drainage of peatlands strongly alters processes of decomposition, we included measurements after drainage as well. Results revealed the immediate respiration of root exudates in peat, mainly as C O 2 , while C H 4 release was associated with a lag time of several days. However, the largest proportion of added root exudates remained in the solid and liquid phase of peat. In conclusion, our findings suggest that no priming occurred as added substrates remained immobile in peat. [ABSTRACT FROM AUTHOR]

Non-equilibrium vibrational dissociation CO2 â†' CO + O at translationalâ€"rotational temperatures T â©˝ 1200 K is investigated with semi-empiric and computational models. The governing parameter Q / n 0 2 has been introduced, where Q is the specific volumetric power coupled into vibrational states and n 0 is the initial number density of CO2. It has been shown that the non-equilibrium vibrational process can only be triggered when Q / n 0 2 exceeds some critical value determined by the speed of vibrational relaxation. Simple semi-empiric calculations are backed by the state-to-state simulations of the CO2 vibrational kinetics in two-modes approximation performed for conditions of microwave sustained gas discharges. The vibrational kinetics model is benchmarked against the experimental vibrational relaxation times as well as the shock tube data on the rate of the process CO2 + M â†' CO + O + M for M = Ar and literature data for M = CO2. At T = 300 K the estimated Q / n 0 2 crit ≂ 6 Ă— 1 0 âˆ' 40 W m3 or Q / p 2 crit ≂ 35 W (mâˆ'3 Paâˆ'2) (p is the gas pressure). Q / p 2 crit is found to always increase with increased T. [ABSTRACT FROM AUTHOR]

The use of metal-organic frameworks (MOF) nanoparticles as nucleating agents in gas dissolution foaming processes is presented. In this work, MOF nanoparticles with three different particle sizes were synthetized and introduced in film composites based on polystyrene at 1 wt.%. The addition of nanoparticles with high affinity to CO2, which is the gas used as a physical blowing agent, can contribute to increase the nucleation efficiency in comparison with the classical heterogeneous route using non CO2-philic particles. Nanoparticles dispersion in solids and cellular structure in foams were studied as a function of the particle size and foaming parameters, studying for first time the impact of MOF nanoparticles on the nucleation by gas dissolution foaming. Nucleation efficiencies in the order of 10−2 were achieved for PS/MOF composites. In addition, the thermal stability of the cellular structure in the composites was enhanced regarding to PS matrix, preserving the cellular structure regardless the foaming temperature. Therefore, MOF nanoparticles have emerged as promising nucleating agents in foaming procedures. [ABSTRACT FROM AUTHOR]

This two-parts article introduces a novel hybrid propulsion system based on the DEA compressor. The system encompasses a Pulse Detonation TurboDEA as the master engine that supplies several full-electric ancillary thrusters called DEAThruster. The system, called the propulsion set, can be categorized as a distributed propulsion system based on the design mission and number of ancillary thrusters. Part B of this article explains the performance sizing of the propulsion set designed in part A. Evaluating the performance of the propulsion, computer programs are written for all major components of the both master engine and ancillary thruster. The intake, compressor, detonation process, diffusers, axial turbine, and exit nozzle are modeled under certain flight conditions, and their performances are revealed and analyzed. The flight conditions are considered from the static condition at the sea level up to flight Mach number 5 at an altitude of 20,000 m. The performance of the propulsion set is also compared with some aircraft propulsions modeled by similar studies in all important aspects. [ABSTRACT FROM AUTHOR]

Background. The COVID-19 pandemic leads to several debates regarding the possible risk for healthcare professionals during surgery. SAGES and EAES raised the issue of the transmission of infection through the surgical smoke during laparoscopy. They recommended the use of smoke evacuation devices (SEDs) with CO2 filtering systems. The aim of the present study is to compare the efficacy of different SEDs evaluating the CO2 environmental dispersion in the operating theater. Methods. We prospectively evaluated the data of 4 group of patients on which we used different SEDs or standard trocars: AIRSEAL system (S1 group), a homemade device (S2 group), an AIRSEAL system + homemade device (S3 group), and with standard trocars and without SED (S4 group). Quantitative analysis of CO2 environmental dispersion was carried out associated to the following data in order to evaluate the pneumoperitoneum variations: a preset insufflation pressure, real intraoperative pneumoperitoneum pressure, operative time, total volume of insufflated CO2, and flow rate index. Results. 16 patients were prospectively enrolled. The [CO2] mean value was 711 ppm, 641 ppm, 593 ppm, and 761 ppm in S1, S2, S3, and S4 groups, respectively. The comparison between data of all groups showed statistically significant differences in the measured ambient CO2 concentration. Conclusion. All tested SEDs seem to be useful to reduce the CO2 environmental dispersion respect to the use of standard trocars. The association of AIRSEAL system and a homemade device seems to be the best solution combining an adequate smoke evacuation and a stable pneumoperitoneum during laparoscopic surgery. [ABSTRACT FROM AUTHOR]

In the context of peak carbon and carbon neutrality, the utilization of CO2 has attracted attention with the aim of reducing carbon emissions by converting CO2 into high-value chemicals or energy. Methanol (MeOH), which is both a hydrogen and a carbon carrier, is considered the most promising among the CO2-conversion products. This paper focus on routes for electrochemical conversion of CO2 to MeOH using green power and green hydrogen to achieve negative CO2 emissions. Three feasible technical routes for electrochemical conversion of CO2 to MeOH are proposed in this paper: Route 1, electrolysis of water to H2 and hydrogenation of CO2 to MeOH; Route 2, electrochemical reduction of CO2 to MeOH; and Route 3, co-electrolysis of CO2–H2O to syngas and synthesis of MeOH from syngas. Techno-economic assessments of the three routes are conducted using technical maturity surveys, system simulations and cost analyses to provide reference data for route selection for CO2 conversion to MeOH in China. Compared with the other routes, Route 1 is advantageous in terms of technical maturity and commercial application prospects. Although Route 1 is presently economically unviable, it is expected to achieve profitability and commercial application in the future with decreases in the cost of renewable power and continuous development of water-electrolysis technology. [ABSTRACT FROM AUTHOR]

CO2 can be used as a soft oxidant for oxidative dehydrogenation of light alkanes (CO2-ODH), which is beneficial to realize the reuse of CO2 and meet the demand for olefins. The core of this reaction is the catalyst. Cr-based catalysts have attracted much attention for their excellent catalytic performance in CO2-ODH reactions due to their various oxidation states and local electronic structures. In this paper, the synthesis and modification methods of Cr-based catalysts for CO2-ODH are reviewed. The structure–activity relationship and reaction mechanism are also summarized. Moreover, the reasons for the deactivation of Cr-based catalysts are analysed and the main challenges faced by Cr-based catalysts in the CO2-ODH process, as well as the future development trend and prospect, are discussed. [ABSTRACT FROM AUTHOR]

The generation of carbon dioxide (CO2) from Nordic fulvic acid (FA) solution in the presence of goethite (α-FeOOH) was observed in FA–goethite interaction experiments at 25–80 ℃. CO2 generation processes observed by gas cell infrared (IR) spectroscopy indicated two steps: the zeroth order slower CO2 generation from FA solution commonly occurring in the heating experiments of the FA in the presence and absence of goethite (activation energy: 16–19 kJ mol–1), and the first order faster CO2 generation from FA solution with goethite (activation energy: 14 kJ mol–1). This CO2 generation from FA is possibly related to redox reactions between FA and goethite. In situ attenuated total reflection infrared (ATR-IR) spectroscopic measurements indicated rapid increases with time in IR bands due to COOH and COO– of FA on the goethite surface. These are considered to be due to adsorption of FA on the goethite surface possibly driven by electrostatic attraction between the positively charged goethite surface and negatively charged deprotonated carboxylates (COO–) in FA. Changes in concentration of the FA adsorbed on the goethite surface were well reproduced by the second order reaction model giving an activation energy around 13 kJ mol–1. This process was faster than the CO2 generation and was not its rate-determining step. The CO2 generation from FA solution with goethite is faster than the experimental thermal decoloration of stable structures of Nordic FA in our previous report possibly due to partial degradations of redox-sensitive labile structures in FA. Graphical Abstract [ABSTRACT FROM AUTHOR]

This opinion argues for including indigenous peoples as 'expert' consultants in India's Apex Committee for Implementation of Paris Agreement. Alongside its monitoring and reporting functions, the Apex Committee for Implementation of Paris Agreement is expected to perform substantive functions, including, developing policies and programmes to make India's domestic climate actions compliant with its international obligations under the Paris Agreement. The argument is based on the understanding that indigenous peoples possess a deeper understanding of their ecosystems and share a special relationship with it. Therefore, their knowledge is key to sustainable ecosystem management. At the same time, a co-dependent relationship with Nature makes them disproportionately vulnerable to the impacts of climate change. Unlike other vulnerable groups, the impact on indigenous peoples ripples beyond their economic survival, and threatens their collective physical and spiritual identity. Accordingly, this opinion suggests direct participation of indigenous peoples in conceptualising and implementing policies and programmes aimed at addressing climate change. To that end, it problematizes the narrow understanding of 'experts' reflected in the gazette notification establishing the Apex Committee for Implementation of Paris Agreement, and draws upon United Nations' practice(s) enabling participation of indigenous peoples as 'experts' in its specialised agencies and organs. Accordingly, the opinion also suggests a potential means to operationalize their inclusion in the Apex Committee for Implementation of Paris Agreement. [ABSTRACT FROM AUTHOR]

Indoor air quality (IAQ) is a key factor that could affect the indoor environment and people's health. In this study, we report a comprehensive study on IAQ in 30 dwellings in the temperate zone in China. Thirty naturally ventilated dwellings were selected in the urban area of Kunming, which is the largest city in temperate zone in China. In four seasons, short-term measurement of formaldehyde and benzene, toluene, xylenes-volatile organic compounds and air infiltration rate were conducted in these dwellings. A long-term 1-year monitoring of temperature, relative humidity, fine particulate matter (PM2.5), carbon dioxide (CO2), window-opening behaviour and night-time air change rate (ACR) were conducted in 13 of these dwellings by remote sensors. Short-term measurements showed the mean formaldehyde concentration in summer (100.76 μg/m3), benzene concentration in winter (8.46 µg/m3), PM2.5 concentration (80.4 µg/m3) in spring of 2017 exceeded the Chinese standard, the US Office of Environmental Health Hazard Assessment value and the World Health Organization guidelines. The night-time ACR was the highest in summer (2.1 h−1) and the lowest in winter (1.6 h−1) in bedrooms of 13 long-term monitored dwellings due to seasonal time variation in window opening in bedrooms, which was mainly driven by CO2 concentration, indoor temperature and outdoor PM10 concentration. [ABSTRACT FROM AUTHOR]

Raman spectroscopy has been used extensively to calculate CO2 fluid density in many geological environments, based on the measurement of the Fermi diad split (Δ; cm–1) in the CO2 spectrum. While recent research has allowed the calibration of several Raman CO2 densimeters, there is a limit to the interlaboratory application of published equations. These calculate two classes of density values for the same measured Δ, with a deviation of 0.09 ± 0.02 g/cm3 on average. To elucidate the influence of experimental parameters on the calibration of Raman CO2 densimeters, we propose a bottom-up approach beginning with the calibration of a new equation, to evaluate a possible instrument-dependent variability induced by experimental conditions. Then, we develop bootstrapped confidence intervals for density estimate of existing equations to move the statistical analysis from a sample-specific to a population level. We find that Raman densimeter equations calibrated based on spectra acquired with similar spectral resolution calculate CO2 density values lying within standard errors of equations and are suitable for the interlaboratory application. The statistical analysis confirms that equations calibrated at similar spectral resolution calculate CO2 densities equivalent at 95% confidence, and each Raman densimeter does have a limit of applicability, statistically defined by a minimum Δ value, below which the error in calculated CO2 densities is too high. Graphical Abstract [ABSTRACT FROM AUTHOR]

The roles of different plasma membrane aquaporins (PIPs) in leaf-level gas exchange of Arabidopsis thaliana were examined using knockout mutants. Since multiple Arabidopsis PIPs are implicated in CO2 transport across cell membranes, we focused on identifying the effects of the knockout mutations on photosynthesis, and whether they are mediated through the control of stomatal conductance of water vapour (g s), mesophyll conductance of CO2 (g m), or both. We grew Arabidopsis plants in low and high humidity environments and found that the contribution of PIPs to g s was larger under low air humidity when the evaporative demand was high, whereas any effect of a lack of PIP function was minimal under higher humidity. The pip2;4 knockout mutant had 44% higher g s than wild-type plants under low humidity, which in turn resulted in an increased net photosynthetic rate (A net). We also observed a 23% increase in whole-plant transpiration (E) for this knockout mutant. The lack of functional plasma membrane aquaporin AtPIP2;5 did not affect g s or E , but resulted in homeostasis of g m despite changes in humidity, indicating a possible role in regulating CO2 membrane permeability. CO2 transport measurements in yeast expressing At PIP2;5 confirmed that this aquaporin is indeed permeable to CO2. [ABSTRACT FROM AUTHOR]

Abstract Mankind is constantly pursuing economic growth and social development, and while these bring convenience to people, they involve large amounts of greenhouse gas emissions under the heavy use of energy, which produces quite serious air pollution, which not only affects people's health but also leads to ecological environmental damage. Nowadays, the impact of the environment and the negative impacts of the world's economies while promoting economic growth are the most important issues for economies to achieve balanced development. This study uses the dynamic slack‐based data envelopment analysis (DEA) model to assess the environmental energy efficiency of high‐income economies (including China) and explore the negative impacts on the environment, to obtain a basis for energy‐saving emission reduction methods or configurations by using 48 high‐income economies (including China) from 2010 to 2014. The interperiod (carryover) variable is gross domestic product (GDP). The empirical results show that economies with high energy efficiency have a large consumption of energy and are unable to reduce carbon dioxide emissions. We also find that there exists a difference in the results depending on whether GDP is considered as the carryover variable. European economies are more efficient in energy consumption than others, and Asian economies are the most inefficient. In order to pursue GDP growth, economies need to consider reducing their energy consumption and CO2 emissions and improve their energy usage efficiency, further implementing sustainability.

Introduction:  CO2 pneumoperitoneum can influence the biological behavior of neuroblastoma (NB). Angiogenesis and genetic features are responsible for malignant phenotype of this tumor. We examined the CO2 effects on N-Myc, vascular endothelial growth factor (VEGF), and matrix metalloproteinase-2 (MMP-2) expression as critical biomarkers of tumor invasiveness, in NB cells without N-Myc amplification.Materials and Methods:  SH-SY5Y cells were exposed to CO2 (100%) at 15 mm Hg pressure for 4 hours and then moved to normal condition for 24 hours. Control cells were incubated with 5% CO2 for the same time. In control and CO2-exposed cells, the messenger ribonucleic acid (mRNA) levels of hypoxia-inducible factor (HIF)-1α, HIF-2α, VEGF-A, and MMP-2 were quantified by real-time polymerase chain reaction. N-Myc expression was evaluated by Western blot analysis.Results:  The exposure to 15 mm Hg CO2 (100%) for 4 hours induced an increase in HIF-1α, but not in HIF-2α, mRNA levels. No differences were observed in N-Myc expression between exposed and control cells at each incubation time. Similarly, no significant differences were found for VEGF-A and MMP-2 transcript levels. In CO2 exposed cells, we observed only a slight increase in both VEGF-A and MMP-2 mRNA levels after 4 and 24 hours in comparison to controls.Conclusion:  In our study, the hypoxic environment induced by CO2 exposure does not affect the expression of critical biomarkers of NB aggressiveness, such as N-Myc, VEGF, and MMP-2, in human SH-SY5Y NB cells without N-Myc amplification. These data suggest that CO2 pneumoperitoneum might not adversely impact NB cell invasiveness; however, it is necessary to evaluate these effects in others in vitro and in vivo models. [ABSTRACT FROM AUTHOR]

Abstract Climate change‐induced warming and ocean acidification are considered two imminent threats to marine biodiversity and current ecosystem structures. Here, we have for the first time examined an animal's response to a complete life cycle of exposure to co‐occurring warming (+3°C) and ocean acidification (+1,600 μatm CO2), using the key subarctic planktonic copepod, Calanus finmarchicus, as a model species. The animals were generally negatively affected by warming, which significantly reduced the females’ energy status and reproductive parameters (respectively, 95% and 69%–87% vs. control). Unexpectedly, simultaneous acidification partially offset the negative effect of warming in an antagonistic manner, significantly improving reproductive parameters and hatching success (233%–340% improvement vs. single warming exposure). The results provide proof of concept that ocean acidification may partially offset negative effects caused by warming in some species. Possible explanations and ecological implications for the observed antagonistic effect are discussed.

The privileged salen ligands coordinated with a metal center have demonstrated their successful applications in many challenging reactions. Moreover, their relatively straightforward preparations and an ease of structural modifications are also very attractive. The CoIII–salen complex has demonstrated to be one of the most efficient catalysts for the copolymerization of CO2 with epoxides. Especially, the elaborate combination of two or more CoIII–salen units into one single molecule may enforce an intramolecular, cooperative reaction pathway, resulting in enhanced reaction rates or/and higher selectivities. Otherwise, the reactivity and/or selectivity will be reduced, or some side reactions may occur. Herein, various bimetallic CoIII complexes based on different linking groups are reported to bridge two salen planes, including flexible and rigid structures, together with their reactivities and selectivities toward copolymerization of CO2 with meso‐epoxides. The asymmetric depletion in copolymerization CO2 with cyclohexene oxide mediated by monometallic CoIII complex 2 is first observed, demonstrating the bimetallic mechanism; especially, the comparative kinetic measurements are performed as a function of reaction temperature to assess the activation barrier for production of copolymers for bi‐ and monometallic CoIII complexes. This study is expected to be instructive and meaningful to design more efficient bimetallic catalyst and to improve the copolymerization selectivity. [ABSTRACT FROM AUTHOR]

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CO2 capture, utilization and storage (CCUS) is recognized as a uniquely important option in global efforts to control anthropogenic greenhouse-gas (GHG) emissions. Despite significant progress globally in advancing the maturity of the various component technologies and their assembly into full-chain demonstrations, a gap remains on the path to widespread deployment in many countries. In this paper, we focus on the importance of business models adapted to the unique technical features and sociopolitical drivers in different regions as a necessary component of commercial scale-up and how lessons might be shared across borders. We identify three archetypes for CCUS development— resource recovery , green growth and low-carbon grids —each with different near-term issues that, if addressed, will enhance the prospect of successful commercial deployment. These archetypes provide a framing mechanism that can help to translate experience in one region or context to other locations by clarifying the most important technical issues and policy requirements. Going forward, the archetype framework also provides guidance on how different regions can converge on the most effective use of CCUS as part of global deep-decarbonization efforts over the long term. [ABSTRACT FROM AUTHOR]

The operation of heating, cooling and air-conditioning (HVAC) in buildings often adheres to fixed time schedules. However, associating HVAC schedules to the occupant's presence patterns can save a significant amount of energy, reducing operation periods to the required minimum. Therefore, automated occupancy estimation provides valuable input to efficient building control strategies. This work discusses the validation and adjustment for two carbon dioxide-based occupancy detection algorithms based on data from ten multi-person offices. Both methods are based on a carbon dioxide mass balance equation. However, they follow two different philosophies. One model is deterministic and includes a more detailed representation of the system, whereas the other model includes stochastic elements and was based on fewer assumptions. Both approaches show similar and promising results. The advantages and drawbacks of each method are reviewed. Furthermore, adjustments of the algorithms to the given conditions and possible future improvements are discussed. [ABSTRACT FROM AUTHOR]

The effects of straw alone or combined with industrial and agricultural wastes as fertilizers on greenhouse gas (GHG) emissions are still poorly known in cropland areas. Here, we studied the effects of 3.5 Mg ha−1 straw and 3.5 Mg ha−1 straw combined with 8 Mg ha−1 of diverse wastes on GHG emission in a subtropical Jasminum sambac plantation in southeastern China. There were five treatments in a completely randomized block design: control, straw only, straw + biochar, straw + steel slag, and straw + gypsum slag. Emissions of carbon dioxide were generally higher in the treatments with waste than in the control or straw-only treatments, whereas the contrary pattern was observed in CH4 and N2O emission rates. Moreover, the total global warming potentials (GWPs) were no significantly higher in most of the amended treatments as compared to the control and straw-only treatments. In relation to the treatment with only straw, GWPs were 9.4% lower when steel slag was used. This finding could be a consequence of Fe amount added by steel slag, which would limit and inhibit the emissions of GHGs and their transport from soil to atmosphere. Our results showed that the application of slags did not increase the emission of GHGs and that the combination of straw with steel slag or biochar could be more effective than straw alone for controlling GHGs emission and improve soil C and nutrient provision. [ABSTRACT FROM AUTHOR]

Most CO2 separation membranes are polymeric membranes owing to low cost and easy processability. Nevertheless, conventional polymeric membranes may suffer from a compromise between permeability and selectivity represented by the Robeson upper bound curves. Mixed‐matrix membranes (MMMs), prepared by adding nanomaterials in polymer matrices, can achieve both high gas permeability and selectivity with the potential for future applications. This review summarizes gas transport channels constructed with different dimensional nanomaterials in MMMs such as 1D, 2D, and 3D nanomaterials which have been widely researched in recent years, and discusses the effect of different gas transport channels in CO2 separation MMMs. The challenges about each kind of gas transport channels are outlined and future prospects are suggested. [ABSTRACT FROM AUTHOR]

In this study, zinc oxide nanoparticles immobilized by methylenebisacrylamide were used for anaerobic consortium application and were examined for biomass retention capacity characterized in terms of volatile solids and specific methanogenic activity. The upflow anaerobic sludge blanket reactor was operated at various hydraulic retention times and was fed with palm oil mill effluent as a carbon source. The highest methane production rate of 510 mL CH4·L−1·h−1 with a methane yield of 68.3 L CH4 g−1·CODadded was obtained at palm oil mill effluent concentration of 20 g COD·L-1 and 24 h of hydraulic retention time. The average biogas (4.5 L) showed methane content and chemical oxygen demand reduction of 84.5 and 95.7%, respectively. Rmax was 570 mL L−1·POME·h−1 at 15% of zinc oxide nanoparticles, with butyrate and acetic acid in an effluent contained when operated at a hydraulic retention time of 24 h and a palm oil mill effluent concentration of 20 g COD L−1. A CO2 reduction of 93.6% was obtained at 15% w/v loading of zinc oxide nanoparticle. Experiments demonstrated that with the granule bead size of immobilized zinc oxide nanoparticle of 3.99 mm, production of CH4 and sequester of CO2 were 650 m3·d−1 and 456 m3·d−1, respectively. At 15% zinc oxide nanoparticle, granule leakage was found to be 0.065 mg·L−1. It is significant that this is the first report on immobilized zinc oxide nanoparticle granule biomass for biogas production from wastewater. [ABSTRACT FROM AUTHOR]

The increase of fossil-fuel-derived CO2 in the atmosphere has led to the dilution of the atmospheric radiocarbon concentration, but due to the costly instrumentation, the continuous atmospheric 14C/12C data is incomplete in developing countries, such as in Indonesia. These data give useful information about the level of local and regional fossil emissions. In this study, 14C AMS measurements of local vegetation and woody plant species samples have been used to estimate the rate of fossil-fuel-derived carbon in the plants, which fix the CO2 from the atmosphere by photosynthesis. Evergreen leaf samples were collected in September 2018 on the island of Bali in different, diverse districts in local and urban areas. The samples from the densely populated areas show observable fossil fuel emissions and show that the Δ14C level is close to zero ‰, similar to the natural level. [ABSTRACT FROM AUTHOR]

We have studied the synthesis of five-membered cyclic carbonates through the cycloaddition of CO2 to epoxides by using acyclic guanidinium salts. We have found that the cycloaddition reactions proceed smoothly at ordinary temperatures and pressures and result in good yields when acyclic guanidinium iodides are employed as catalysts. Both cation moiety and anion moiety of the guanidinium salts play important roles in their catalytic activity. It is essential to have active hydrogens on the cation moiety as well as an iodide ion as the anion moiety so as to achieve good catalytic activity. Guanidinium iodides with three or more active hydrogens give cyclic carbonates in high yields in polar solvents such as 1-methylpyrrolidin-2-one, whereas the guanidinium iodides with one or two active hydrogens show good catalytic activity in less polar solvents such as 2-methyltetrahydrofuran. [ABSTRACT FROM AUTHOR]

A series of cobalt oxide (Co3O4) loaded (5–20wt%) γ-Al2O3, MgO and SiO2 supported catalysts were prepared by wetness-impregnation method and tested for oxidative dehydrogenation (ODH) of ethylbenzene (EB) in vapor phase atmospheric pressure conditions. Among Co oxide doped catalysts, Co3O4/γ-Al2O3 (CA) has afforded a superior catalytic activity in view of desirable EB conversion and styrene (ST) yields. Thus unusual catalytic properties of 15CA catalyst were supposed to be due to adequate acidic-basic nature, thermal stability and synergistic effect of Co-Al species along with uniform distribution of active Co oxide ions. Moreover, dramatic catalytic activity of Co3O4 incorporated γ-Al2O3 catalyst can be explained on the basis of beneficial CO2 conversion subsequently production of better CO yields during the online gas analysis. All calcined catalysts have been characterized by different sophisticated techniques to elucidate the surface metal composition and influence of Co3O4 oxide species on catalytic activity presentation during the oxidative dehydrogenation of EB reaction. [ABSTRACT FROM AUTHOR]

The UK government has set a new legally binding target under the Climate Change Act 2008. It now aims to cut carbon emissions to net zero by 2050. This opinion considers whether carbon emissions can really be reduced in practice at the local level in the UK, and uses Liverpool City Council as a case study example. It argues that without coordinated action by various people within the council, between its respective departments, other authorities, organisations, key stakeholders and residents the new target is very unlikely to be met. It also highlights the fact that notwithstanding this, the ice caps are actually melting even faster than even the scientists had predicted and that time is actually running out. It argues that radical action is what is needed and that it is needed now. [ABSTRACT FROM AUTHOR]

Palsa peatland soils are known as significant terrestrial storage of the Earth's soil carbon. The response of these soils to changing climate may result in a strong feedback to global carbon balance. In laboratory, we investigated the effect of rising temperatures on the upper (T1) and lower (T2) horizons of Turbic Histic Cryosols using sequential (S) and equal-time (ET) methods. The S method was applied to estimate the response of organic carbon mineralization rate (R) to sequential temperature increase from 5 to 30°C; the ET method was used to study the response of the basal (microbial) respiration rate to equal-time incubation at 5, 15, and 25°C. The Q10 coefficient was calculated. In the T1 horizon, both methods (S and ET) demonstrated a positive response of respiration to the rise in temperature. The respiration intensity increased by 91 and 84%, respectively. In the T2 horizon, it increased by 93 and 91%, respectively. However, despite the overall positive response of soil respiration to the rise in temperature, the Q10 values demonstrated differences in the temperature sensitivity of soil respiration. These values were maximal in the cold (5–15°C) range for both horizons. For most of temperature ranges, Q10 was higher for T2 than for T1. For the T1 horizon and S method, Q10 slightly varied (2.7–3.0), whereas in the case of the ET method, it decreased by 3.3 times from the cold (4.9) to the warm 15–25°C (1.5) temperature range. For the T2 horizon, the S method also did not cause significant shifts in Q10 (3.0–3.5); the ET method caused a decrease in Q10 by 1.5 times from the cold (4.3) to the warm (2.8) temperature range. To sum up, the ET method leads to a wider variation of Q10 values in comparison with the S method thus indicating its better applicability for temperature sensitivity studies with palsa peatland soils under laboratory conditions. [ABSTRACT FROM AUTHOR]

Background: Cool and dry gas insufflation during laparoscopy induces hypothermia and cytokine increase, with significant perioperative morbidity. Our aim was to assess if warmed and humidified CO2 insufflation with HumiGard™ device can achieve significant benefits over standard insufflation in terms of risk of hypothermia, cytokine response, blood gases, and intra- and postoperative parameters, in the setting of robot-assisted radical prostatectomy (RARP). Methods: This was a prospective, randomized controlled clinical trial. Sixty-four patients with prostate cancer undergoing RARP were randomized to receive warmed and humidified CO2 insufflation with HumiGard device, plus hot air warming blanket (treatment group, H + WB), or standard CO2 insufflation, plus hot air warming blanket (control group, WB). Body core temperature (BCT), plasma levels of IL-6 and TNF-α, pain scores, and intraoperative parameters were recorded. The data were analyzed according to the Bayesian paradigm. Results: Intraoperative BCT increased in both groups during surgery, with a statistically significant difference favoring group H + WB, ending at 0.2°C higher on average than group WB. No difference across groups was shown for cytokine levels. Blood gas parameters were not affected by warmed CO2 insufflation. No statistical differences were noted for pain scores and the other intra- and postoperative parameters. Conclusions: During RARP, warm and humidified CO2 insufflation with the HumiGard device was more effective than the standard CO2 insufflation in maintaining the patient's heat homeostasis, even if the difference was minimal. No imbalances were detected on blood gas analyses. No benefit could be shown in terms of cytokine levels and pain scores. [ABSTRACT FROM AUTHOR]

In the presence of PdCl2 [P(n -Bu)3 ]2 (10 mol%) and ZnEt2 , 2-furyl and 2-pyrrolylmethyl acetate were carboxylated with CO2 (1 atm), affording doubly carboxylated products in good yields. In this dearomative transformation, α,ε-dicarboxylic acids were obtained selectively, in contrast to our previous report in which α,γ-dicarboxylic acids were selectively produced from 2-indolylmethyl acetates. In contrast, 5-thiazolylmethyl acetate and naphthylmethyl acetates predominantly underwent single carboxylation. [ABSTRACT FROM AUTHOR]

In the presence of PdCl2 [P(n -Bu)3 ]2 (10 mol%) and ZnEt2 , 2-furyl and 2-pyrrolylmethyl acetate were carboxylated with CO2 (1 atm), affording doubly carboxylated products in good yields. In this dearomative transformation, α,ε-dicarboxylic acids were obtained selectively, in contrast to our previous report in which α,γ-dicarboxylic acids were selectively produced from 2-indolylmethyl acetates. In contrast, 5-thiazolylmethyl acetate and naphthylmethyl acetates predominantly underwent single carboxylation. [ABSTRACT FROM AUTHOR]

The functional food value of herbal plants is greatly related to their contents of valuable phytochemicals. Regarding its impact on primary and secondary plant metabolism, CO 2 enrichment could be a candidate strategy to modulate the levels of nutritionally and medicinally interesting phytochemicals in herbal plants. Herein, the concentrations of 81 metabolites and minerals were evaluated in shoot tissues of parsley and dill grown under two levels of CO 2 , ambient (378 ± 25 µmole CO 2 mole −1 air, aCO 2 ) and elevated (627 ± 24 µmole CO 2 mole −1 air, eCO 2 ). Regardless of the plant species, eCO 2 improved the levels of soluble sugars, starch, organic acids, some EAAs, most of USFA, total phenolics, total flavonoids and vitamins A and E. However, notable variations in the metabolites responsiveness to eCO 2 were recorded among the tested plant species. Moreover, considerable improvements in the total antioxidant capacity, antiprotozoal, antibacterial and anticancer activities were recorded for parsley and dill in response to eCO 2 . [ABSTRACT FROM AUTHOR]