High CO2 Levels Research Articles

Primary cordierite with > 2.5 wt% CO2 from the UHT Bakhuis Granulite Belt, Surinam: CO2 fluid phase saturation during ultrahigh-temperature metamorphism

The Paleoproterozoic Bakhuis Granulite Belt (BGB) in Surinam, South America, shows ultrahigh-temperature metamorphism (UHTM) at temperatures of around 1000 °C which, unusually, produced peak-to-near-peak cordierite with sillimanite and, in some cases, Al-rich orthopyroxene on a regional scale. Mg-rich cordierite (Mg/(Mg + Fe) = 0.88) in a sillimanite-bearing metapelitic granulite has a maximum birefringence of second-order blue (ca. 0.020) indicative of a considerable amount of CO2 (> 2 wt%) within its structural channels. SIMS microanalysis confirms the presence of 2.57 ± 0.19 wt% CO2, the highest CO2 concentration found in natural cordierite. This high CO2 content has enabled the stability of cordierite to extend into UHT conditions at high pressures and very low to negligible H2O activity. Based on a modified calibration of the H2O–CO2 incorporation model of Harley et al. (J Metamorph Geol 20:71–86, 2002), this cordierite occupies a stability field that extends from 8.8 ± 0.6 kbar at 750 °C to 11.3 ± 0.65 kbar at 1050 °C. Volatile-saturated cordierite with 2.57 wt% CO2 and negligible H2O (0.04 wt%) indicates fluid-present carbonic conditions with a CO2 activity near 1.0 at peak or near-peak pressures of 10.5–11.3 kbar under UHT temperatures of 950–1050 °C. The measured H2O content of the cordierite in the metapelite is far too low to be consistent with partial melting at 1000–1050 °C, implying either that nearly all of any H2O originally in this cordierite under UHT conditions was lost during post-peak cooling or that the cordierite was formed after migmatization. The high level of CO2 required to ensure fluid saturation of the c. 11 kbar UHT cordierite is proposed to have been derived from an external, possibly mantle, source.

Monitoring of Subsurface Emissions and the Influence of Meteorological Factors on Landfill Gas Emissions: A Case Study of a South African Landfill

The government-accredited GA 2000 landfill gas analyzer was used to monitor the landfill gas (methane (CH4) and carbon dioxide (CO2)) generated from the subsurface of a landfill. Eighteen gas sample probes were constructed and placed approximately 100 m apart on the boundaries of the landfill site. The monitoring of the gases was conducted over a period of two years, taking into consideration the different seasons of the year. Results from the study show that as the LFG migrates toward the boundaries of the landfill in the subsurface, higher CO2 levels are recorded when compared to CH4. This could be a result of the oxidation process and some other factors present in the landfill. CH4 emissions ranged from 0.54 to 2.22% v/v in 2020. For the year 2021, the CH4 concentration ranged from 0.24% v/v to 2.33% v/v. In addition, the CO2 concentration for the year 2020 ranged from 4.66 to 6.37% v/v. In the year 2021, the CO2 concentration ranged from 3.5 to 6.56% v/v. Furthermore, higher gaseous concentrations were found in the surrounding active cells, where there is currently deposition of municipal solid waste (MSW). However, the monitoring probes situated in areas far away from the landfill recorded lower gaseous levels. This study recommends that there should be continuous monitoring of the LFG emission from the Thohoyandou landfill due to the different results obtained over the temporal variation. Frequent monitoring will help prevent the potential risk of fire hazards and pollution in the future.

An intelligent indicator for warning of short‐term high CO2 damage to garlic scapes

AbstractA pH‐sensitive indicator film based on CO2 change was prepared by mixing a water‐soluble indicator (bromocresol green and chlorophenol red sodium) with a film‐forming carrier (methyl cellulose (MC), polyvinyl alcohol (PVA) and glycerin). The innovation is not only to analyse the response characteristics of the colorimetric indicator to CO2, but also to optimise the preparation parameters of the film. The response experiment showed that CO2 dissolved rapidly in water and the pH value remained unchanged after reaching equilibrium, with a one‐to‐one relationship between pH and CO2 concentration. As the CO2 concentration rose from 18% to 20%, the colour of the indicator film changed from blue–purple to yellow–green in a different colour space, allowing the change to be easily distinguished by the naked eye. The optimum parameters (13 g‧L−1 MC, 5 g‧L−1 PVA, 10 g‧L−1 glycerin, 15 ml‧L−1 indicator and a casting amount of 0.2 ml‧cm−2) for preparing the intelligent film were optimised based on puncture strength (PS), water vapour permeability (WVP), water solubility (WS), casting time (CT) and colour performance. Evaluating this application using garlic scapes stored at 15°C revealed that the total colour difference was 34.23 as the CO2 concentration increased from 18.7% to 20.4%, and the colour of the indicator film changed from blue–purple to yellow–green. Therefore, the intelligent packaging film was able to effectively provide a warning when garlic scapes were exposed to damage from a short‐term high CO2 level.

A high concentration CO2 pool over the Indo-Pacific Warm Pool

Anthropogenic emissions have produced significant amount of carbon dioxide (CO2) in the atmosphere since the beginning of the industrial revolution. High levels of atmospheric CO2 increases global temperature as CO2 absorbs outgoing longwave radiation and re-emits. Though a well-mixed greenhouse gas, CO2 concentration is not uniform in the atmosphere across different altitudes and latitudes. Here, we uncover a region of high CO2 concentration (i.e. CO2 pool) in the middle troposphere (500–300 hPa) over the Indo-Pacific Warm Pool (IPWP, 40° E–140° W, 25° S–25° N), in which the CO2 concentration is higher than that of other regions in the same latitude band (20° N–20° S), by using CO2 satellite measurements for the period 2002–2017. This CO2 pool extends from the western Pacific to the eastern Indian Ocean. Much of the CO2 pool is over the western Pacific Ocean (74.87%), and the remaining lies over the eastern Indian Ocean (25.13%). The rising branch of Walker circulation acts as a “CO2 Chimney” that constantly transports CO2 released from the natural, human-induced and ocean outgassing processes to the middle and upper troposphere. The CO2 pool evolves throughout the year with an average annual trend of about 2.17 ppm yr−1, as estimated for the period 2003–2016. Our analysis further reveals that La Niña (El Niño) events strengthen (weaken) the CO2 pool in the mid-troposphere. The radiative forcing for the CO2 pool suggests more warming in the region and is a grave concern for global warming and climate change.

Effects of Increasing Indoor Negative Air Ions on Cognitive Performance and Health of High Pure CO2 Level-Exposed College Students

Cognitive performance is essential to foster learning. High CO2 concentrations are common in classrooms and can lead to reduced cognitive performance. Negative air ions (NAIs) can improve cognitive performance. This study explored the effects of indoor NAIs on the cognitive performance and health of college students exposed to a high pure CO2 environment. Forty college students were exposed to four sets of conditions (NAIs+500 ppm CO2, 500 ppm CO2, NAIs+2500 ppm CO2, and 2500 ppm CO2). Participants’ cognitive performance, including reasoning, short-term memory, concentration, and verbal ability, was assessed under each condition using the Cambridge Brain Sciences tool. Acute health symptoms were investigated using a subjective questionnaire, and simultaneously, participants’ blood pressure, heart rate, and lung function were tested. Analysis of variance (ANOVA) in a repeated-measures design was used to analyze the effects of different conditions on cognitive performance and health symptoms. The results revealed that the different levels of CO2 and NAIs had a significant effect on cognitive performance after one hour of exposure and had no significant effect after three hours of exposure. Compared with 500 ppm CO2, 500 ppm CO2+NAIs resulted in better reasoning skills, short-term memory, and verbal skills, and 2500 ppm CO2 led to poorer reasoning skills. The addition of NAIs to 2500 ppm CO2 improved reasoning skills, short-term memory, and verbal skills. The benefits of adding NAIs to high pure CO2 condition on cognitive performance are more noticeable than those to low CO2 condition. Moreover, adding NAIs can reduce nasal irritation or dryness, skin irritation or dryness, sleepiness symptoms, and heart rate elevation caused by pure CO2. However, the benefits of NAIs on health symptoms and physiology were not observed under the 500 ppm CO2 condition. Adding NAIs to a high pure CO2 level is an effective means to improve the cognitive performance and health of college students.

Tenrecs deal with poor air quality like reptiles

Dealing with dangerously high CO2 levels is a regular part of life for burrowing creatures. ‘Most animals that are able to tolerate such environments reduce their metabolic rate to re-balance their energy demands’, says Matthew Pamenter from the University of Ottawa, Canada. So, when he heard Frank van Breukelen of the University of Nevada, USA, talk about his burrowing tenrec (Tenrec ecaudatus) colony at a conference in 2019, he realised that the animals might also experience dangerous CO2 concentrations – up to 13.5%, compared with 0.04% in the atmosphere – when hibernating with burrow-mates for 8–9 months. Yet tenrecs are not regular mammals. They can remain active even when their body temperature plummets to 12°C; so how do they cope with the toxic air in their hibernation burrows?Pamenter contacted van Breukelen to suggest a collaboration, and in March 2020, Maiah Devereaux (University of Ottawa) joined Claudia Silva Rubio and van Breukelen at the University of Nevada to find out how tenrecs deal with excessive CO2 and low O2. ‘Our tenrecs are handled very frequently and so they are very docile. To be honest, they are kind of lazy!’ chuckles van Breukelen, who recalls that the animals were content to hang out in a respirometry chamber while Devereaux and Silva Rubio measured the tenrecs’ breath rate and O2 consumption to calculate their metabolic rate. The duo then modified the air mixture the tenrecs were breathing – first reducing the O2 content from 21% to 9% and 4%, before boosting the CO2 levels from 0% to 5% and 10% – at 28°C and 16°C, to find out how the mammals responded. ‘Trying to maintain a stable [gas] flow rate required some troubleshooting’, says van Breukelen.Even when the tenrecs were breathing normal air in the cooler conditions, the active animals’ metabolisms responded unconventionally. Some barely breathed at all – only consuming 2 ml O2 min−1 kg−1 – while others inhaled a colossal amount (23 ml O2 min−1 kg−1) relative to the warmer tenrecs, which only inhaled 12 ml O2 min−1 kg−1 at the most. Raising the CO2 levels in the air didn't affect the range of the cold tenrec's metabolic rates; however, when the team reduced the animals’ O2 supply, the chilly animals no longer had the wide range of metabolic rates they had when breathing normal air.The air temperature also had a major impact on the way the tenrecs breathed when their air was contaminated with CO2. The warmer animals began hyperventilating when the CO2 levels increased, in contrast to the cooler tenrecs, which were more like other burrowing mammals and did not hyperventilate.In short, the tenrecs’ breathing and metabolism were more affected by the environmental temperature than the build-up of toxic CO2 and quantity of O2 available. In addition, the animals in the colder conditions allowed their body temperatures to drift, with some cooling to 20°C while others remained at 32°C regardless of the air quality; all of the tenrecs in 28°C air maintained a warm body temperature (∼32°C) despite the air conditions. The physiological responses of the tenrecs were more like those of cold-blooded reptiles than those of warm-blooded burrowing mammals, probably because they don't have to maintain a high body temperature to survive. van Breukelen exclaims, ‘Many of the things that tenrecs do result in me saying, “How the heck do they do this?”’, and he is excited to find out how the animals cope with poor air quality when breathing as little as once every 45 min while hibernating.

Review on CeO2-Based Photocatalysts for Photocatalytic Reduction of CO2: Progresses and Perspectives

A promising approach is to transform carbon dioxide (CO2) into renewable, high value-added products with minimal environmental impact and maximum efficiency. Many problems, including energy shortages and environmental degradation, are caused by high CO2 levels, but this can help. Photocatalytic reduction methods are a promising technology for solving these problems. Cerium dioxide (CeO2) is one of the most important rare earth oxides, and cerium dioxide-based photocatalysts have gained a lot of attention in recent years due to their distinctive features, such as their tunable electronic structures and their excellent photocatalytic performances. However, the wide energy band of cerium oxide limits its utilization of light. This review provides various strategies for the modification of cerium oxide, encompassing external atom doping, heterostructure fabrication, defect fabrication, and crystal plane modulation, to improve the catalytic performance of CeO2. The fundamentals of the conversion of CeO2-based photocatalysts into high value-added products are also summarized. Finally, the challenges and prospects of CeO2-based catalysts for photocatalytic reduction of CO2 are presented.

A direct numerical simulation analysis of localised forced ignition in turbulent slot jets of CH4/CO2 blends

The early stages of flame evolution following successful localised forced ignition of different CH[Formula: see text]/CO[Formula: see text] blends in a slot jet configuration have been analysed using three-dimensional direct numerical simulations. The simulations have been conducted for three different concentration levels of CO[Formula: see text] in the fuel blend composed of CH[Formula: see text] and CO[Formula: see text] (ranging from 0% to 20% by volume). The effects of CO[Formula: see text] concentration have been analysed based on five different energy deposition scenarios which include situations where the mean mixture composition at the ignitor varies, but not its location in space, whereas other cases represent the scenarios where the mean mixture composition within the energy deposition region remains constant, but its spatial location changes with CO[Formula: see text] concentration. The most favourable region for successful flame development following thermal runaway, from the mixture composition standpoint (i.e. the highest flammability factor), has been found to be displaced close to the nozzle with an increase in CO[Formula: see text] concentration. The flame development following thermal runaway exhibits initial growth of hot gas kernel followed by downstream advection and eventual flame propagation along with radial expansion with a possibility of flame stabilisation irrespective of the level of CO[Formula: see text] concentration. The triple flame propagation has been found to play a key role in the upstream flame propagation and eventual stabilisation. The orientation of the local flame normal plays a key role in the flame stabilisation. The lift off height has been found to increase with increasing CO[Formula: see text] concentration which also adversely affect flame stabilisation for high levels of CO[Formula: see text] concentration.

Cell Plasticity of Marine Mediterranean Diazotrophs to Climate Change Factors and Nutrient Regimes

Ocean acidification and warming are current global challenges that marine diazotrophs must cope with. Little is known about the effects of pH and temperature changes at elevated CO2 levels in combination with different nutrient regimes on N2 fixers, especially on heterotrophic bacteria. Here, we selected four culturable diazotrophs, i.e., cyanobacteria and heterotrophic bacteria, found in association with the endemic Mediterranean seagrass Posidonia oceanica. We tested different pH (from pH 4 to 8) and temperature levels (from 12 to 30 °C), under different nutrient concentrations of both phosphorus, P (0.1 µM and 1.5 mM), and iron, Fe (2 nM and 1 µM). We also tested different CO2 concentrations (410 and 1000 particles per million (ppm)) under different P/Fe and temperature values (12, 18, and 24 °C). Heterotrophic bacteria were more sensitive to changes in pH, temperature, and CO2 than the cyanobacterial species. Cyanobacteria were resistant to very low pH levels, while cold temperatures stimulated the growth in heterotrophic bacteria but only under nutrient-limited conditions. High CO2 levels (1000 ppm) reduced heterotrophic growth only when cultures were nutrient-limited, regardless of temperature. In contrast, cyanobacteria were insensitive to elevated CO2 levels, independently of the nutrient and temperature levels. Changes in N2 fixation were mainly controlled by changes in growth. In addition, we suggest that alkaline phosphatase activity (APA) and reactive oxidative species (ROS) can be used as biomarkers to assess the plasticity of these communities to climate change factors. Unlike other studies, the novelty of this work lies in the fact that we compared the responses of cyanobacteria vs. heterotrophic bacteria, studying which changes occur at the cell plasticity level. Our results suggest that the responses of diazotrophs to climate change may depend on their P and Fe status and lifestyle, i.e., cyanobacteria or heterotrophic bacteria.

Multi-temporal variability forecast of particulate organic carbon in the Indonesian seas.

The current global condition characterized by high levels of CO2 is altering the carbon cycle and elemental biogeochemistry, resulting in subsequent global warming, climate change, ocean acidification, and the indirect response of deoxygenation. The features of Indonesia's coastal ecosystems and continental shelf waters also contribute to spatio-temporal ocean carbon variability. For instance, the level of particulate organic carbon (POC) will change annually, and thus, over a decadal period, ocean dynamics may affect the temporal variability of POC. Motivated by such conditions, future forecasting is needed to envision the productivity of Indonesian seas by predicting vital parameters such as POC. This research aimed to forecast the temporal variability of POC in Indonesian waters. The Seasonal Autoregressive Integrated Moving Average (SARIMA) forecasting model was used by considering the lowest value of the Akaike information criterion (AIC) and the mean absolute percentage error/MAPE (threshold < 10%). Using the highest correlation coefficient (threshold: 0.75), we obtained the best fit for forecasting POC temporal variability. Hindcast POC data (2002-2020/2021) was used to train the forecasting model. The result shows that forecasting of POC temporal variability can be conducted up to 2030. The validity of prediction is ensured for less than 5years forward after 2020 with correlation coefficients of 0.65 and 0.83 for seasonal and monthly POC, respectively. The hindcast and forecast estimates of POC in the Indonesian seas show a decreasing trend. The present study emphasizes the different forecasting results obtained using the different approaches of annual versus inter-annual variability. A sustained research effort is still required to assess POC forecasting for its potential benefits in marine system monitoring and assessment.

The decline of plant mineral nutrition under rising CO2: physiological and molecular aspects of a bad deal.

The elevation of atmospheric CO2 concentration has a strong impact on the physiology of C3 plants, far beyond photosynthesis and C metabolism. In particular, it reduces the concentrations of most mineral nutrients in plant tissues, posing major threats on crop quality, nutrient cycles, and carbon sinks in terrestrial agro-ecosystems. The causes of the detrimental effect of high CO2 levels on plant mineral status are not understood. We provide an update on the main hypotheses and review the increasing evidence that, for nitrogen, this detrimental effect is associated with direct inhibition of key mechanisms of nitrogen uptake and assimilation. We also mention promising strategies for identifying genotypes that will maintain robust nutrient status in a future high-CO2 world.

Score-driven threshold ice-age models: Benchmark models for long-run climate forecasts

Climate variables are known to be subject to abrupt changes when some threshold levels are surpassed. We use data for the last 798,000 years on global ice volume (Ice), atmospheric carbon dioxide level (CO2), and Antarctic land surface temperature (Temp) to model and measure those long-run nonlinear climate effects. The climate variables have very long and asymmetric cycles, created by periods of upward trends, followed by periods of downward trends driven by exogenous orbital variables. The exogenous orbital variables considered by the Milankovitch cycles are eccentricity of Earth’s orbit, obliquity, and precession of the equinox. We show that our new score-driven threshold ice-age models improve the statistical inference and forecasting performance of competing ice-age models from the literature. The drawback of using our 1000-year frequency observations, is that we cannot measure the nonlinear climate effects of humanity created during the last 250 years, which are known to have generated abrupt structural changes in the Earth’s climate, due to unprecedented high levels of CO2 and Temp, and low levels of Ice volume. On the other hand, the advantage of using low-frequency data is that they allow us to obtain long-run forecasts on what would have occurred if humanity had not burned fossil fuels since the start of the Industrial Revolution. These long-run forecasts can serve as benchmarks for the long-run evaluation of the impact of humanity on climate variables. Without the impact of humanity on climate, we predict the existence of turning points in the evolution of the three climate variables for the next 5,000 years: an upward trend in global ice volume, and downward trends in atmospheric CO2 level and Antarctic land surface temperature.

CO2 bee anaesthetic can cause complications

Most people don't really pay attention to the air they breathe. However, if you go up a mountain, where the oxygen levels are lower, you'll notice as you huff and puff while taking a normal walk around town. Changes in the amounts of the different gases that make up the air we breathe can have noticeable effects in other animals as well, especially insects. ‘Low concentrations of carbon dioxide (CO2) are often used as an attractant or repellent’, says Anna Cressman of Pennsylvania State University, USA; however, high concentrations can cause behavioural and physiological changes, and can even result in unconsciousness. Frequently, researchers use 100% CO2 to anaesthetize insects (called CO2 narcosis), but the side-effects of exposure to high levels of CO2 are often not considered. Working with Etya Amsalem, also of Pennsylvania State University, Cressman asked what is causing these side-effects in bumblebees (Bombus impatiens) – the lack of oxygen, or the high level of CO2 itself.Carbon dioxide is usually found at levels of around 0.04% in normal air, so the duo pumped either 100% CO2, 50% CO2, normal air with low oxygen, or 100% nitrogen gas (which means that there is no oxygen) into a chamber containing bees for 1 min, recording how many of the bees passed out, and then filmed the insects to monitor how they behaved once they awoke, as well as checking how the different gases affected bees with different roles, queens and workers, in the colony.Sure enough, when the team compared the effects of pure CO2 and 100% nitrogen, the bees’ responses were quite different. Even though both gases knocked the bees out, after recovering from the sedation, the bees that had inhaled 100% CO2 had different side-effects from the bees anaesthetised with pure nitrogen. The CO2-anaesthetised bees pumped their abdomens more and the queens took longer to regain consciousness. In addition, when Cressman compared the effects of the different gases on worker and queen bees, the workers produced smaller eggs after several doses of 100% CO2, whereas the queens produced larger eggs after a single dose of the pure gas. Cressman also compared the impact of the two gases on the expression of six specific genes – involved in egg production and protection from low oxygen levels – and she discovered that the genes reacted differently.The responses of the queen bees and workers to pure CO2 also differed: the queens seemed to be more vulnerable to the gas than the workers, only requiring one dose, to begin showing side-effects during their recovery, in contrast to the workers, which required multiple doses of the gas before the side-effects became apparent. ‘The fact that the physiological changes are different suggests that CO2 is not simply depriving the bees of oxygen but does something else and is likely to have a more direct impact on cells’, Amsalem concludes.So, inhaling CO2 can affect bees with different roles in the colony in different ways, and researchers should be aware of the potential complications that this may cause when using the gas to anaesthetize insects in their experiments.

AIRO: Development of an Intelligent IoT-based Air Quality Monitoring Solution for Urban Areas

Air pollution is the contamination of the atmosphere by any biological, physical, or chemical means. Bengaluru, the Silicon Valley of India, has air pollution levels that exceed WHO standards. Its air has high PM10, PM2.5, SO2, NO2, and CO2 levels, exposing residents to an increased risk of respiratory diseases. AIRO, a decentralised IoT-based air quality monitoring solution, is proposed to calculate the (Air Quality Index) AQI in real-time and notify the users of dangerous AQI levels. Unlike the city's fixed air quality monitoring stations, this portable system can easily be integrated into everyday items for computing real-time air quality at any given place. The proposed solution is then validated using a physical prototype incorporated into a water bottle. Using the Intel Edison development platform, this prototype is equipped with a GPS module, Wi-Fi module, PMS5003, MQ131, MQ135, MQ136, MQ7 sensors, and an LCD Display. The prototype records the air quality indicators, calculates the AQI, and sends the data to the AWS Cloud Server. After an in-depth analysis of the cloud data, the daily and weekly AQI is predicted for multiple locations in the city. A hybrid CNN-Bi-LSTM model is proposed for predicting AQI, which needs to be evaluated at the city scale for dependable results. Finally, a smartphone app is developed using Android Studio and Python to monitor the air quality and notify the users. The users also have an option to select a location and get the real-time and predicted AQI. In the future, this hybrid deep-learning model can be extended to other cities using the transfer learning approach.

Beneficial Impact of Hypercapnic Conditions During Early Incubation on Broiler Hatchability. Embryo Mortality and Postnatal Performance

We assessed the extent to which CO2 levels altered different hatching and chick parameters. In Experiments 1 and 2, a total of 16,184 eggs from Cobb 500 breeders were incubated in single stage incubators under three different conditions: (a) standard ventilated incubator (CON, Exp.1 and 2); (b) increasing CO2 levels during the first 10 days of incubation until 0.7% (V7000, Exp. 1) and (c) until 0.8% (V8000, Exp. 2). High levels of CO2 improved hatchability, possibly due to lower embryo mortality from ED18 to ED21. Internal and external pipping in experiment V8000 started later than in CON; nevertheless, the hatch still occurred before in V8000 as a result of the shorter durations of external pipping and hatch. In Experiment 3, a total of 12,138 eggs from Cobb 500 were incubated in single stage incubators under three different conditions: (a) standard ventilated incubator (CON); (b) increasing CO2 levels until 1.0% with ventilation (V10000); and (c) increasing CO2 levels until 1.0% without ventilation (NV10000). Hypercapnic conditions led to better hatchability and lower embryo mortality from ED18 to ED21. Internal pipping started earlier in NV10000, but only V10000 differed from CON in terms of the average time for hatch. Hypercapnic groups also showed shorter durations of external pipping and hatch when compared to CON. Post-hatch analysis revealed no differences among incubation conditions in terms of body weight gain, feed conversion ratio, mortality by sudden death syndrome, and production factor. Nevertheless, V10000 showed a lower mortality by ascites and a better viability when compared to CON, while NV10000 presented a higher mortality by other causes. Altogether, our findings indicate that in addition to not being detrimental to embryo survival, high CO2 levels reduce embryonic mortality at 18-21 days of incubation and increase hatchability.

The use of the news in predicting the clinical status of copd patients presenting to the emergency department with a the complaint of dyspnea

Aim: COPD (Chronic Obstructive Pulmonary Disease) is a lung disease that causes impairment in quality of life. NEWS (National Early Warning Score) is a scoring system that evaluates patients' general condition and mortality. We examined the utility of NEWS in predicting the clinical status of COPD patients. Materials and methods: COPD patients admitted to the emergency department were included in the study. Age, gender, comorbid diseases, occupational exposure status, smoking/tobacco intake, hematological and radiological examinations, vital values, and continuous drug use status of the patients were evaluated. The GCS (Glasgow Coma Scale), CCI (Charlson Comorbidity Index), and NEWS values of the patients were calculated. Chi-square, Fisher's exact, unpaired t-test, or Mann-Whitney U tests were applied according to the normal distribution. Values of p&lt;0.05 were considered statistically significant. Results: Of the patients, 82% (n=205) were male, and 18% (n=45) were female. Of the patients, 67% had comorbid diseases. Coronary artery disease was the most common comorbid disease (n=68, 27%). Low saturation, pH, mean blood pressure, low hemoglobin, high CO2, creatinine, urea, CRP, and INR levels were associated with mortality. In non-survival patients, the GCS was low, whereas the CCI and NEWS were high. Conclusions: The NEWS value should be considered in order to determine the clinical status of patients presenting with a COPD attack, to make the decision for hospitalization, and to predict their mortality. Keywords : Emergency department,COPD exacerbation,NEWS,mortality

CO2 Levels Modulate Carbon Utilization, Energy Levels and Inositol Polyphosphate Profile in Chlorella.

Microalgae have a growing recognition of generating biomass and capturing carbon in the form of CO2. The genus Chlorella has especially attracted scientists' attention due to its versatility in algal mass cultivation systems and its potential in mitigating CO2. However, some aspects of how these green microorganisms respond to increasing concentrations of CO2 remain unclear. In this work, we analyzed Chlorella sorokiniana and Chlorella vulgaris cells under low and high CO2 levels. We monitored different processes related to carbon flux from photosynthetic capacity to carbon sinks. Our data indicate that high concentration of CO2 favors growth and photosynthetic capacity of the two Chlorella strains. Different metabolites related to the tricarboxylic acid cycle and ATP levels also increased under high CO2 concentrations in Chlorella sorokiniana, reaching up to two-fold compared to low CO2 conditions. The signaling molecules, inositol polyphosphates, that regulate photosynthetic capacity in green microalgae were also affected by the CO2 levels, showing a deep profile modification of the inositol polyphosphates that over-accumulated by up to 50% in high CO2 versus low CO2 conditions. InsP4 and InsP6 increased 3- and 0.8-fold, respectively, in Chlorella sorokiniana after being subjected to 5% CO2 condition. These data indicate that the availability of CO2 could control carbon flux from photosynthesis to carbon storage and impact cell signaling integration and energy levels in these green cells. The presented results support the importance of further investigating the connections between carbon assimilation and cell signaling by polyphosphate inositols in microalgae to optimize their biotechnological applications.

A year-round study of ambient gaseous pollutants, their atmospheric chemistry and role in secondary particle formation at an urban site in Delhi

Continuous measurement of the four atmospheric gaseous pollutants (SO2, NO2, CO and O3) were made for a period of about one year (June 2019 to April 2020) at a representative urban site in Delhi. All the four pollutants were found to be elevated during the post-monsoon season (October–December) with peak values observed in the month of November. The present study explores the trends of the atmospheric gas pollutants in a highly polluted atmosphere. In addition, we have highlighted the role of these pollutants in atmospheric chemistry including particle formation and successive growth. During two short-term study periods, a distinct particle growth was observed in the night time associated with the oxidation of SO2 into sulphate particles especially during the post-monsoon season explaining the haze events observed frequently in the city with additional influence of meteorological factors. Unusual high levels of CO observed during pre-monsoon season (March–April) are likely to be associated with the elevated levels of natural biogenic emissions. The present study is one of the best examples validating the conventional secondary chemistry of gaseous pollutants in urban atmosphere.

Carbon Dioxide Monitoring inside an Australian Brewery Using an Internet-of-Things Sensor Network

Maintaining a high standard of indoor air quality (IAQ) is vital to ensuring good human health. The concentration of CO2 in air is a good proxy for IAQ, while high levels of CO2 have been shown to cause cognitive or physiological impairment. Work environments that generate CO2 as an inherent part of their business present a unique and significant risk in terms of poor IAQ. Craft breweries generate CO2 and, unlike larger breweries, often lack the technology to capture and re-use the fermentation CO2 for beer carbonation. The purpose of this study is to demonstrate that the venting of fermentation CO2 and the unintentional venting of CO2 during the filling of CO2 storage tanks can cause the indoor CO2 levels to rise significantly. This is shown by monitoring CO2 levels inside an Australian craft brewery using a newly developed system containing three Internet of Things (IoT) sensor nodes positioned strategically in different sections of the brewery. The maximum CO2 level recorded was in excess of 18,000 ppm, with the maximum time period levels exceeding 1000 and 10,000 ppm being equivalent to 425 and 26 min, respectively. The identification of differences in measured CO2 at different times and locations throughout the brewery reveals that a single hard-wired CO2 sensor may be inadequate to support IAQ monitoring. For this purpose, a network of portable or wearable CO2 sensor nodes may be most suitable. The battery life of the sensors is a key consideration, and the current sensor battery life is too short. Low-power sensors and communication protocols are recommended for this task.

High-throughput investigation of Nb and Ta alloying effects on the microstructure and properties of a novel Ni-Co-based superalloy

Recent research has focused on the development of disk superalloys with better temperature capability and mechanical properties via a new alloying concept that uses high levels of Co and γ′ formers of Al, Ti, Ta and Nb to produce composite precipitation strengthening. In this work, alloying effects of Nb and Ta on phase stability, microstructure and property of a novel Ni-Co-based superalloy were systematically investigated using the high-throughput multi-component diffusion multiples (MCDMs) in combination with various high-throughput measurement tools. A deep learning-based image recognition method was developed to efficiently extract the γ′ morphological features, including area fraction, particle size, number density. The rapid characterizations of alloy compositions, microstructure and Vickers hardness (HV) enable us to establish the composition-dependent microstructural characteristics and mechanical property as well as their correlation with the phase stability, which can be directly applied for designing Ni-Co-based superalloys with superior microstructure stability and strength.