High Concentrations Of Carbon Dioxide Research Articles

Atmospheric carbon dioxide concentration as fuel gauge

Climate change skeptics like to point to the high atmospheric carbon dioxide concentration in paleo records as “proof” of the exaggeration of the climate change agenda. Instead of debunking these arguments, the present paper represents a thought experiment that considers the atmospheric carbon dioxide concentration in the past as a proxy for fossil fuel reserves and interprets the contemporary rise in carbon dioxide concentration as a fuel gauge to estimate the exhaustion of the remaining fossil fuel reserves under different energy consumption scenarios. The resulting conclusion is that the dangers of exhausting the remaining fossil fuel resources are likely on par with the anticipated adverse effects of climate change and should convince even climate change skeptics that the transition to non-fossil energy sources is inevitable and urgent since the remaining fossil fuel reserves will be likely exhausted in less than a century. The presented analysis goes further than the currently adopted “net-zero” ambitions. It demonstrates that there is no room for compromise and the transition has to be “true-zero” use of fossil fuels. Accounting gimmicks like carbon capture and sequestration or carbon trading are just as unsustainable as the continued reliance on fossil fuels.

PERFORMANCE EVALUATION OF A GAS ENGINE OPERATING ON HIGH-CO₂ NATURAL GAS AT LATE INJECTION TIMING

The increasing energy demand in the transportation sector and the depletion of conventional fossil fuel reserves necessitate the exploration of alternative fuel sources. Malaysia holds significant untapped natural gas reserves with high carbon dioxide (CO₂) content, which has historically been considered unsuitable for commercial use due to economic and technical challenges associated with CO₂ removal. This study investigates the feasibility of utilizing highCO₂ natural gas directly in internal combustion (IC) engines and its effects on engine performance. A single-cylinder, four-stroke, direct-injection compressed natural gas (DI-CNG) engine was used to evaluate the impact of CO₂ addition on key performance parameters, including brake torque, brake power, brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE). Experiments were conducted at a late injection timing of 120° crank angle before top dead center (BTDC) and an engine speed of 2100 rpm, with CO₂ proportions ranging from 0% to 40% by volume. The results demonstrated that moderate CO₂ additions (up to 20%) improved BTE and reduced BSFC due to enhanced combustion control and lean-burn stability. However, higher CO₂ proportions (>20%) led to significant reductions in brake torque and brake power, attributed to dilution effects and reduced calorific value. The findings suggest that controlled CO₂ inclusion in CNG can optimize combustion and emissions, offering a potential pathway for utilizing Malaysia’s undeveloped natural gas reserves.

Sulfate assimilation regulates antioxidant defense response of the cyanobacterium Synechococcus elongatus PCC 7942 to high concentrations of carbon dioxide.

The adaptive evolution of cyanobacteria over a prolonged period has allowed them to utilize carbon dioxide (CO2) at the low concentrations found in the atmosphere (0.04% CO2) for growth. However, whether the exposure of cyanobacteria to high concentrations of CO2 results in oxidative stress and the activation of antioxidant defense response remains unknown, albeit fluctuations in other culture conditions have been reported to exert these effects. The current study reveals the physiological regulation of the model cyanobacterium Synechococcus elongatus PCC 7942 upon exposure to 1% CO2 and the underlying mechanism. Exposure to 1% CO2 was demonstrated to induce oxidative stress and activate antioxidant defense responses in S. elongatus. Further analysis of variations in metabolism between S. elongatus cells grown at 0.04% CO2 and exposed to 1% CO2 revealed that sulfate assimilation was enhanced after the exposure to 1% CO2. A strain of S. elongatus lacking the gene cysR, encoding a global transcriptional regulator for genes involved in sulfate assimilation, was generated by deleting the gene from the genomic DNA. A comparative analysis of the wild-type and cysR-null strains indicated the regulation of the antioxidant response by sulfate assimilation. In addition, lines of evidence were presented that suggest a role of degradation of phycobilisome in the antioxidant response of S. elongatus under conditions of 1% CO2 and sulfate limitation. This study sheds light on the in situ effects of high CO2-induced stress on the ecophysiology of cyanobacteria upon exposure to diverse scenarios from a biotechnological and ecological perspective.IMPORTANCECyanobacteria that grow autotrophically with CO2 as the sole carbon source can be subject to high-CO2 stress in a variety of biotechnological and ecological scenarios. However, physiological regulation of cyanobacteria in response to high-CO2 stress remains elusive. Here, we employed microbial physiological, biochemical, and genetic techniques to reveal the regulatory strategies of cyanobacteria in response to high-CO2 stress. This study, albeit physiological, provides a biotechnological enterprise for manipulating cyanobacteria as the chassis for CO2 conversion and sheds light on the in situ ecological effects of high CO2 on cyanobacteria.

Optimizing biogas upgrading containing high carbon dioxide content for enhanced biomethane quality and energy efficiency using blended amine absorption

Optimizing biogas upgrading containing high carbon dioxide content for enhanced biomethane quality and energy efficiency using blended amine absorption

State Dependency of Dynamic and Thermodynamic Contributions to Effective Precipitation Changes

Abstract Reliable projections of the future hydrological cycle are needed for designing adaptation and mitigation measures under global warming. However, uncertainties in the projected sign and magnitude of effective precipitation changes (precipitation minus evaporation, P − E) remain high. Here, we examine the state dependency of circulation, temperature, and relative humidity contributions to P − E changes in simulations of the Last Glacial Maximum (LGM), mid-Holocene, and abrupt quadrupling of the atmospheric carbon dioxide concentration. To this purpose, we apply a moisture budget decomposition and a thermodynamic scaling approximation to CMIP6/PMIP4 simulations with the Earth system model MPI-ESM1.2. We find that the importance of thermodynamic and dynamic contributions to P − E changes and the patterns of dynamic contributions depend strongly on the underlying forcing. Greenhouse gas forcing leads to a stronger thermodynamic response than dynamic response. The LGM ice sheets yield a large dynamic contribution with zonally heterogeneous patterns. Orbital forcing induces a predominantly dynamic response with a hemispherically antisymmetric structure. We also identify state-invariant features: The importance of temperature and relative humidity contributions to specific humidity changes is consistent across states, and the wet-get-wetter–dry-get-drier paradigm proposed for global warming holds in almost all regions dominated by thermodynamic contributions. By definition, the P − E budget and the respective thermodynamic, dynamic, and transient eddy contributions vanish in the global mean. Moreover, we find that for increasing length scales, the spatial variability of these contributions decays with similar rates. We suggest repeating our analysis for more models and states which could help constrain hydroclimate projections. Significance Statement We aim at improving our understanding of the influence of changes in winds and water vapor on the local balance between precipitation and evaporation. To this end, we compare simulations for two past climate states with an idealized high carbon dioxide concentration scenario. We find characteristics that depend on the underlying state and characteristics that are consistent across states. Our results help to identify what we can learn from past climate states about precipitation changes under future greenhouse gas emission scenarios. So far, we only analyzed simulations from one model. Therefore, we suggest to repeat our analysis with more models and for more past climate states to confirm our results.

Review of Physical Properties of High Carbon Dioxide Content

Review of Physical Properties of High Carbon Dioxide Content

Study on Dense Phase Separation of Associated Gas with High Carbon Dioxide Content

Study on Dense Phase Separation of Associated Gas with High Carbon Dioxide Content

Effects of Climate Change and Greenhouse Gas Emission Relevance to Environmental Stress on Horticultural Crops

Global climate change significantly impacts the yield and quality of sustainable horticulture crops. Rising global temperatures have forced the agricultural community to modify planting and harvesting timetables, frequently calling for earlier crop production. Notably, several concerning elements are brought about by climate change, including greenhouse gas emissions (GHGs), higher temperatures, higher concentrations of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), ozone depletion (O3), and deforestation. All of these factors exacerbate environmental stresses on crops. Climate change is, therefore, likely to have a negative impact on livestock production and crop yields. Thus, the main goal of the review paper is to provide a thorough summary of the various aspects that affect the production of fruits, vegetables, and plantation crops in horticulture, with a focus on greenhouse gas emissions and environmental stressors like high temperatures, droughts, salinity, and CO2 emissions. This assessment will also look at how new greenhouse technologies and horticultural crop varieties can be used to lessen the adverse effects of climate change on crops.

Changes in the Basic Metabolic Rate of the Crew under conditions of Eight Months Isolation in a Hermetic Object with a Moderately Hypercapnic Artificial Gas Environment. Message 1

Within the framework of the SIRIUS international project, a study of the basic metabolism of a gender-mixed crew in a sealed object with a moderately high content of carbon dioxide in the artificial atmosphere was conducted. Using mathematical methods, we estimated the basic metabolic rate of a crew of 5 people (3 men and 2 women) at rest for 240 days of isolation when simulating a flight to the Moon in the “SIRIUS-21” experiment. The period of isolation lasted from 4.11.2021 to 3.07.2022. BMR studies were performed twice in the background (on –38–35, –6 days), 7 times during the isolation period (23–25, 50–52, 84–86, 110–112, 154–156, 181–183, 222–224 day) and twice during the aftereffect period (+1–2, +8–9 days). It was found that the basic metabolism in isolation decreased by an average of 6 kcal/kg of body weight per day compared with natural environmental conditions. The crew was isolated from the effects of seasonal lighting changes in a sealed facility, the Ground-Based Medical and Technical Facility (NEK) of the Scientific Research Center of the Russian Federation - Institute of Biomedical Problems of the Russian Academy of Sciences, which does not have portholes, and where artificial lighting was created without seasonal changes. Inside the NEK, the comfort temperature was constantly maintained at +21–23 degrees Celsius and an artificial gas environment was formed, in which the oxygen content was maintained at 21%, carbon dioxide no more than 0.35%. In conditions of isolation from the action of these geophysical environmental factors, seasonal fluctuations in basal metabolism with a wave span of an average of 4 kcal /kg of body weight per day were detected: in the spring calendar season, the level of basal metabolism increased relative to the winter season. Seasonal local maximums and minimums of the basic exchange level for 2 calendar seasons (winter 2021/2022 and in spring 2022) were determined for each of the volunteers. The results obtained in this work can be applied in the field of space physiology to clarify the calculated oxygen reserves and caloric content of the crew’s rations for a long-term space mission, as well as in the design and programming of life support systems and thermal management systems for inhabited hermetic objects.

Integrated Fertilizers for Sustainable Wheat Production to Improve Food Security—A Comprehensive Review

ABSTRACTWheat is a key cereal crop that is substantial to global food security. Fertilizers are crucial in wheat production and significantly impact the yield. This review aims to evaluate the effectiveness of inorganic, organic, and integrated fertilizers in terms of sustainable wheat production and economic and environmental benefits. For this review, we thoroughly examined 133 previous research findings. The results indicate that inorganic fertilizers play a vital role in improving wheat yield. However, continuous use of inorganic fertilizers pollutes the environment, affects beneficial microorganisms in the soil, and increases the emissions of greenhouse gases, consequently decreasing crop yield. Organic fertilizers enhance soil quality, which is critical for crop growth and development. However, a high concentration of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) are emitted from organic fertilizers, but the CO2 emission rate is less than the sequestration rate. Integrated fertilizers trade off the drawbacks of both inorganic and organic fertilizers. Integrated fertilizers decrease nitrous oxide (N2O) and ammonia (NH3) emissions and carbon loss by 11%–24%, 13%–27%, and 18%, respectively, compared to the sole use of fertilizers. From the review analysis, the highest grain yield (4855 kg ha−1) and net benefit ($2836.66) are achieved by using a combination of 75% organic and 25% inorganic fertilizers at a rate of 120 kg N ha−1. Therefore, this combination is recommended for the users. Furthermore, a site‐specific approach research is needed on integrated fertilizers that simultaneously focus on economic and environmental profits. Also, there must be a policy that supports the farmers in teaching, training, and subsidizing them to adopt integrated fertilizers for sustainable wheat production and improving food security.

Numerical Simulation of Corrosive Flow in the Production End of Carbon Capture, Utilization, and Storage-Enhanced Oil Recovery Backflow Wastewater Pipeline

In a carbon capture, utilization, and storage-enhanced oil recovery (CCUS-EOR) system process, the high carbon dioxide content and high acid value of the fluid at the extraction end are treated at the wastewater treatment station and then flow through the transfer station of the gathering system. The reinjection system’s pipelines at the transfer station are prone to corrosion and leakage risks. A steady-state nonisothermal flow and corrosion model was established to examine this corrosive phenomenon by utilizing the principles of fluid dynamics and electrochemical corrosion. The study examined how flow velocity, temperature, pressure, and pH affected the pipeline’s corrosion. Simulation results showed flow velocity increased in specific places of both straight and curved pipeline sections. The velocity near the inner wall of curved portions was higher, making them more susceptible to cavitation damage. Faster flow rates, lower pH values, higher temperatures, and smaller pipeline diameters all contributed to increased corrosion on the inner walls of wastewater pipelines. The highest simulated corrosion rate was 8.3162 mm/a corresponding to the smallest pipeline diameter (100 mm), lowest pH (4), highest temperature (60°C), and highest flow rate (36.847 m/s). When designing the CCUS-EOR system, the nonmetallic pipeline should be given priority. If carbon steel metal pipelines are utilized, it is best to use larger-diameter materials in the engineering design. Additionally, procedures such as adding corrosion inhibitors to regulate pH values and lowering the temperature of wastewater conveyance might be explored to reduce corrosion on the pipeline’s inner walls.

Tandem mass tag-based quantitative proteomics analysis of modified atmosphere packaging in large yellow croaker (Pseudosciaena crocea) fillets during refrigerated storage

Tandem mass tag-based quantitative proteomics analysis of modified atmosphere packaging in large yellow croaker (Pseudosciaena crocea) fillets during refrigerated storage

Global climate change impacts on the potential distribution of typical Trachinotus fishes and early warning assessment of invasions

Global climate change impacts on the potential distribution of typical Trachinotus fishes and early warning assessment of invasions

Effects of Carbon Dioxide and Nitrogen Oxides on Climate Change in Afghanistan

Climate change is a global threat to the environment and human health. Two of the main greenhouse gases that cause the greenhouse effect and raise global temperatures are carbon dioxide and nitrogen oxides. In this review paper, we investigated the effects of carbon dioxide and nitrogen oxides on climate change and the effects of climate change on Afghanistan. We found that high concentrations of carbon dioxide, which is now CO2 levels, have increased by 50% than before the Industrial Revolution, contributing to a rise in global temperature and precipitation. At the same time, Nitrous oxide is an important greenhouse gas, with 310-fold higher potential for global warming than CO2 and leads to the depletion of stratospheric Ozone and other Nitrogen oxides, has a significant impact on plant health, including effects on chlorophyll levels, oxidative stress, and antioxidant responses. Afghanistan’s climate change is predicted to increase the country’s prevalence of illnesses linked to dust storms and poor air quality, especially in Kabul, the nation’s capital. In addition, air pollution in Kabul is also likely to increase as a result of climate change. The alarming impacts of air pollution, with more than 3,000 deaths attributed to air pollution annually. Additionally, at least 700,000 individuals in Kabul have experienced various respiratory diseases. Due to climate change, Afghanistan’s total glacier area has shrunk by 13.8%. In 2023, Afghanistan experienced early snow melt and below-average precipitation, causing second-season and irrigated crops to have less access to water. Reducing emissions and coping with the changing climate are essential steps towards tackling the complex issues these gases present and their wider effects on the environment and human health.

Fluid Phase Equilibria Carbon Dioxide + Decane + Hexadecane Ternary System

Fluid Phase Equilibria Carbon Dioxide + Decane + Hexadecane Ternary System

Influence of carlsbad thermo-mineral water on the autonomic nervous system

The drinking cure is an essential part of Karlovy Vary spa treatment. The effect of Karlovy Vary mineral water on the autonomic nervous system has not yet been investigated. Based on case analyses, we hypothesized that the effects of the drinking cure have an effect on the functional activity of the autonomic nervous system. The prospective research study had the character of an experiment in clinical conditions. Research file: Health women n = 15, age 40-50 years. Methodology: Before and 30 min after the experimental sequence, the functional state of the autonomic nervous system was examined by the method of spectral analysis of heart rate variability in the ortho-clino-orthostatic position. The experimental sequence: rest sitting position (pre) drinking cure in a sitting position (application of 350 ml thermo-mineral water 50 °C) rest sitting position (post). The length of all monitored intervals was 300 heartbeats. Results: Pre-post status (30–50 minutes after the application of the drinking cure): an increase in the overall activity of the autonomic nervous system an increase in activity in the sympathetic and parasympathetic frequency bands reducing the heart rate blood pressure values did not change. Effects during the application of the drinking cure (comparison with a rest sitting position): a decrease in the overall activity of the autonomic nervous system an increase in sympathetic activity and decrease in parasympathetic activity an increase in heart rate an increase in systolic and diastolic blood pressure. Conclusions: A prospective research study highlighted the reflexive relationships between the digestive system and the cardiovascular system. These relationships are modulated by the autonomic nervous system. Factors that influence the effect of the drinking cure in the area of the upper part of the digestive system are: the rhythm of swallowing and the temperature of the water. Factors that influence the post-effect of the drinking cure in the area of the duodenum and jejunum they probably are: high content of free carbon dioxide and bicarbonate ions in the Carls Bad thermomineral water. These factors apparently activate the motility of the intestinal tract and have an effect on systemic changes of the functional status of the autonomic nervous system.

Effects of CO₂ on the occurrence of decompression sickness: review of the literature.

Inhalation of high concentrations of carbon dioxide (CO₂) at atmospheric pressure can be toxic with dose-dependent effects on the cardiorespiratory system or the central nervous system. Exposure to both hyperbaric and hypobaric environments can result in decompression sickness (DCS). The effects of CO₂ on DCS are not well documented with conflicting results. The objective was to review the literature to clarify the effects of CO₂ inhalation on DCS in the context of hypobaric or hyperbaric exposure. The systematic review included experimental animal and human studies in hyper- and hypobaric conditions evaluating the effects of CO₂ on bubble formation, denitrogenation or the occurrence of DCS. The search was based on MEDLINE and PubMed articles with no language or date restrictions and also included articles from the underwater and aviation medicine literature. Out of 43 articles, only 11 articles were retained and classified according to the criteria of hypo- or hyperbaric exposure, taking into account the duration of CO₂ inhalation in relation to exposure and distinguishing experimental work from studies conducted in humans. Before or during a stay in hypobaric conditions, exposure to high concentrations of CO₂ favors bubble formation and the occurrence of DCS. In hyperbaric conditions, high CO₂ concentrations increase the occurrence of DCS when exposure occurs during the bottom phase at maximum pressure, whereas beneficial effects are observed when exposure occurs during decompression. These opposite effects depending on the timing of exposure could be related to 1) the physical properties of CO₂, a highly diffusible gas that can influence bubble formation, 2) vasomotor effects (vasodilation), and 3) anti-inflammatory effects (kinase-nuclear factor and heme oxygenase-1 pathways). The use of O₂-CO₂ breathing mixtures on the surface after diving may be an avenue worth exploring to prevent DCS.

Entropy Drives Accelerated Ion Diffusion upon Carbon Dioxide Expansion of Electrolytes.

Carbon dioxide-expanded liquids, organic solvents with high concentrations of soluble carbon dioxide (CO2) at mild pressures, have gained attention as green catalytic media due to their improved properties over traditional solvents. More recently, carbon dioxide-expanded electrolytes (CXEs) have demonstrated improved reaction rates in the electrochemical reduction of CO2, by increasing the rate of delivery of CO2 to the electrode while maintaining facile charge transport. However, recent studies indicate that the limiting behavior of CXEs at higher CO2 pressures is a decline in solution conductivity due to reduced polarity, leading to poorer charge screening and greater ion pairing. In this article, we employ molecular dynamics simulations to investigate the energetic driving forces behind the diffusive properties of an acetonitrile and tetrapropylammonium hexafluorophosphate (TPrAPF6) CXE with increasing CO2 concentration. Our results indicate that entropy drives solvent and electrolyte diffusion with increasing CO2 pressure. The activation energy of ion diffusion increases with higher concentrations of CO2, indicating that increasing the temperature may improve solution conductivity in these systems. This trend in the activation energies is traced to stronger cation-anion Coulombic interactions due to weaker solvent screening at high CO2 concentrations, suggesting that the choice of ion may provide a route to diminish this effect.

Discovery of the first hydrothermal field along the 500-km-long Knipovich Ridge offshore Svalbard (the Jøtul field)

Oceanic spreading centers north of Iceland are characterized by ultraslow spreading rates, and related hydrothermal activity has been detected in the water column and at the seafloor along nearly all ridge segments. An exception is the 500-km-long Knipovich Ridge, from where, until now, no hydrothermal vents were known. Here we report the investigation of the first hydrothermal vent field of the Knipovich Ridge, which was discovered in July 2022 during expedition MSM109. The newly discovered hydrothermal field, named Jøtul hydrothermal field, is associated with the eastern bounding fault of the rift valley rather than with an axial volcanic ridge. Guided by physico-chemical anomalies in the water column, ROV investigations on the seafloor showed a wide variety of fluid escape sites, inactive and active mounds with abundant hydrothermal precipitates, and chemosynthetic organisms. Fluids with temperatures between 8 and 316 °C as well as precipitates were sampled at four vent sites. High methane, carbon dioxide, and ammonium concentrations, as well as high 87Sr/86Sr isotope ratios of the vent fluids indicate strong interaction between magma and sediments from the Svalbard continental margin. Such interactions are important for carbon mobilization at the seafloor and the carbon cycle in the ocean.

Moderate greenhouse climate and rapid carbonate formation after Marinoan snowball Earth

When the Marinoan snowball Earth deglaciated in response to high atmospheric carbon dioxide (CO2) concentrations, the planet warmed rapidly. It is commonly hypothesized that the ensuing supergreenhouse climate then declined slowly over hundreds of thousands of years through continental weathering. However, how the ocean affected atmospheric CO2 in the snowball Earth aftermath has never been quantified. Here we show that the ocean’s carbon cycle drives the supergreenhouse climate evolution via a set of different mechanisms, triggering scenarios ranging from a rapid decline to an intensification of the supergreenhouse climate. We further identify the rapid formation of carbonate sediments from pre-existing ocean alkalinity as a possible explanation for the enigmatic origin of Marinoan cap dolostones. This work demonstrates that a moderate and relatively short-lived supergreenhouse climate following the Marinoan snowball Earth is a plausible scenario that is in accordance with geological data, challenging the previous hypothesis.