High Levels Of Carbon Dioxide Research Articles

Quantitative reconstruction of Early Cretaceous dune morphology in the Ordos paleo-desert and its paleoclimatic implications

Deserts are among the most important terrestrial sedimentary environments and have existed in all periods throughout Earth’s history. In contrast to modern deserts, the ability to quantitatively evaluate the area and desertification degrees of ancient deserts is limited due to the lack of unambiguous proxies. Dune morphology and their spatial arrangements directly reflect the degree of desertification of deserts. Recently, a methodology for obtaining the morphological parameters of dunes was established, although it has not been applied to ancient dunes and deserts in deep time. In the Ordos Basin, both the Early Cretaceous desert and modern deserts (Hobq Desert and Mu Us Desert) were well developed and exposed, which makes the Ordos Basin an ideal place to quantitatively evaluate the paleo-desert based on the proposed methodology. In this study, a total of 698 and 1,490 morphological parameters reflecting the Early Cretaceous desert and modern deserts in the Ordos Basin were obtained, respectively. For the Ordos paleo-desert, our results show that its area was larger and its degree of desertification was more severe than those of modern mid-latitude deserts, including the modern desert in the Ordos Basin, but were similar to those of the modern low-latitude deserts. Our results, therefore, suggest that the Ordos paleo-desert was a non-negligible and large desert during an interval of Earth’s history. Since the other controlling factors, such as regional geography and sources of both the ancient and modern deserts in the Ordos Basin, have remained nearly unchanged, we speculate that it may have been the relatively high temperature, high levels of atmospheric carbon dioxide and relatively low precipitation during the greenhouse period (i.e., Early Cretaceous) that led to the large area and severe degree of desertification of the Ordos paleo-desert.

High Carbonate Alkalinity Lakes on Mars and their Potential Role in an Origin of Life Beyond Earth

The exploration of Mars has revealed that its ancient surface hosted lakes with a dazzling array of chemical and physical conditions and processes. The potential habitability of surface waters has driven studies aimed at understanding whether or not Mars once hosted life. High levels of atmospheric carbon dioxide are probable on early Mars, which means that lakes derived from weathering fluids could have contained substantial carbonate alkalinity. Recent studies show that lakes with high carbonate alkalinity are able to concentrate the phosphate and cyanide that are critical for molecular synthesis in the origin of life. While evidence for carbonate-rich Martian lakes remains limited, NASA’s Perseverance rover may reveal clues about the past existence of such waters in Jezero Crater.

The impact of non-renewable energy production and energy usage on carbon emissions: Evidence from China

A high level of carbon dioxide (CO2) emission has become a global issue due to extensive production and energy usage that needs regulators’ attention and researchers’ emphasis. Hence, the study aims to explore the effectiveness of energy production and usage on carbon dioxide emission in China. The current study has taken the electricity production from oil, coal and nuclear as the measurement of energy production, while fossil fuel energy consumption and energy use have been taken as the measurement of energy usage, and energy import has been taken as the control variable. The secondary data has been gathered using a secondary source like World Bank from 1991 to 2020. The Quantile Autoregressive Distributed Lag (QARDL) was employed by the study to examine the linkage among variables, while the Augmented Dickey–Fuller (ADF) test was adopted to check the stationarity. The results revealed that electricity production from oil, coal and nuclear has a positive connection with CO2 emission. The findings also exposed that the FFEC, energy import, and energy use also have a positive linkage with CO2 emission. This study monitors the policymakers while establishing regulations to control CO2 emissions by limiting the country's energy production and usage.

Kindergarten physical setting guidelines: A review from indoor air quality perspectives

The kindergarten’s indoor air contained a number of pollutants, including total volatile organic compounds, particulate matter, carbon monoxide and insufficient ventilation with high carbon dioxide levels, which exceeded the indoor air quality (IAQ) guideline. The presence of these pollutants is caused by various factors including inappropriate physical setting. Indisputably, authorities throughout the countries provide guidelines for designing kindergartens' spaces, however it is limited to general explanations and only guided by early education compliance. It is vital to determine which kindergarten regulations may contribute to poor IAQ. This paper explores national kindergarten physical setting guidelines and how it affects IAQ. A document analysis method was used to determine the characteristics and differences between kindergarten guidelines. Firstly, the composition of each kindergarten guideline was itemised. Then, the study was conducted by making comparisons of the identified items. All the criteria were further reviewed from IAQ perspectives. This study was conducted on guidelines in Australia, Canada, the United States, Singapore and Malaysia. There are five physical setting requirements that influence IAQ : minimum indoor space required per child, sleep area, kitchen and food preparation area, ventilation requirements and furniture and finishes. All activities happen in this microenvironment contribute to IAQ, which is also affected by the ventilation system, furniture and finishes selection. It can be concluded that there is still room for improvement in existing guidelines by taking into account the indoor air perspective. Aside from the main function of kindergarten to provide education, the physical setting of kindergarten also plays a significant role in the growth and health of chidren.

Prediction of Carbon Dioxide Level Using Statistical Learning and Its Potential Correlation With Global Warming

The Industrial Revolution caused a huge change in the climate of our planet. Since the 19th century, a high level of atmospheric carbon dioxide has contributed to global warming and other environmental problems. We first acknowledge the substantial correlations between the CO2 levels or temperatures and the years before creating our models. In this situation, we propose that the ARIMA model, which combines the auto-regression and moving average models, is essential for issue analysis. In order to estimate CO2 concentrations and land-ocean temperatures, we create polynomial models as well as an ARIMA model with seasonality. Following these hypotheses, we discover that the CO2 concentrations and temperatures have a significant direct link. In order to forecast the future relationships between CO2 concentrations and temperatures, we also attempt to employ polynomial function. We constantly reflect on and reexamine the issues as we construct these models in order to have a greater grasp of the circumstances. Each of our models is also evaluated, and the most precise one is used to make forecasts. Based on Matlab, we can quickly calculate the data, utilize iterations to determine the ideal model parameters, and then display our findings in diagrams.

Investigation of duplex stainless steel flow line failure

In the current study, a 2205 duplex stainless-steel gas flowline with a diameter of 6-inch experienced a leak at two different joints after two years of service. The retrieved failed joints showed severe corrosion damage in the weld and heat-affected zones. This investigation revealed that the damage occurred in the flow line at the 4 to 8 o'clock position (i.e., angle positions of 120° to 240°) in contact with the high salinity water, and negligibly occurred in the top part of the pipe exposed to the dry gasses only. The high salinity broke down the passive layer of the steel. Furthermore, the high carbon dioxide level accelerated the corrosion rate at the de-passivated locations. The selective dissolution of the ferrite was partially accelerated due to the enriched-Ni filler metal. Moreover, the excessive heat input resulted in a coarse-grained heat-affected zone. The low nitrogen levels in the pipes and the flanges impaired the pitting and crevice corrosion resistance of the joints. The relatively high temperature also played a role in accelerating the selective dissolution of metal at the damaged locations.

Utilization of Green Material for Concrete in Construction

In this modern technological era today, green materials are highly regarded as one of the most important elements when designing and conducting an environmentally sustainable construction project. The cement that is utilized in conventional concrete today is one of the culprits for the high levels of carbon dioxide generated, which is damaging to the environment. Many researchers have shown and suggested that cement substitution is a favorite technique for minimizing the generation of greenhouse gas (GHG) emissions as well as substituting unused raw materials with concrete. The concept of green concrete promotes sustainable development as it utilizes the least natural resources during production and mainly depends on recyclable waste materials as its main raw material. This paper displays the various designs of green concrete in developed countries by partially replacing cement with recyclable materials such as fly ash, demolished waste from construction sites, electronic waste, carpet fiber waste, palm oil fuel ash, and others. Green concrete endorses the innovative and sustainable use of waste aggregate and unconventional alternative materials to substitute cement within concrete. It is crucial to adopt the use of green concrete, especially in developed countries, as they have the capacity and financial strength to ensure adequate training, public awareness, further research and demonstration projects, as well as suitable standards to be applied to endorse the global application of green concrete in infrastructure projects.

Science, Medicine, and the Anesthesiologist

Science, Medicine, and the Anesthesiologist

Carbon Dioxide Adsorption by a Zinc-Doped Nanocage: DFT-Based Computational Assessment of Gas Pollution Detection and Removal

The high level of carbon dioxide (CO2) greenhouse gas exhaustion to nature could make it a serious pollutant with negative impacts on human and environmental health safety. In this regard, the current work was performed to run computational assessments on employing zinc (Zn)-doped nanocage (C19Zn) for adsorbing the CO2 gaseous substance to approach the detection and removal goals. Accordingly, geometries of the model systems were optimized using density functional theory (DFT) calculations to obtain the minimized energy structures besides evaluating their energy features. The obtained features approved the formation of interacting bimolecular CO2@C19Zn complex of quantum theory of atoms in molecules (QTAIM) analysis, and the evaluated strength indicated the existence of a physical O…Zn interaction for the formation of such a complex system. Moreover, the evaluated electronic molecular orbital features indicated the possibility of detection function for the investigated system. The obtained results of this work revealed that the formation of the CO2@C19Zn complex model could be supposed to conduct two functions of detection and removal of CO2 by the investigated C19Zn nanocage for approaching the issues of dealing with greenhouse pollutants.

City-wide greenhouse gas emissions of communities nearby the world heritage site of Ayutthaya, Thailand

Climate change has emerged one of the greatest threats to sustainable development. Cities are a major contributor to high carbon dioxide levels. This research aimed to quantify city-wide GHG emissions and investigate the potential for climate change mitigation in communities near the World Heritage Site (WHS) of Ayutthaya, Thailand via the multi-criteria analytical hierarchy process (AHP). The total city-wide GHG emission of Ayutthaya Municipality in 2018 was 99,137.04 tCO2eq (1.93 tCO2eq per capita). Energy and waste sectors were the two largest emitters. Pratuchai, the most populated subdistrict and the WHS location, was the largest source of GHGs. However, the cultural heritage site emitted only 0.2% of total GHGs. Based on the IPCC2013 LCA method, residential sector accounted for the largest share (74%), while the WHS contributed only < 1% of total energy-related CO2 emissions. If all the Thailand’s Nationally Determined Contribution (NDC) Roadmap are fully implemented in the residential sector, total GHGs would be reduced by 9735.47% tCO2eq and 6846.86 tCO2eq in 2030. Based on expert interviews, AHP pairwise comparison showed that energy-saving strategies were more preferable than renewable energy technologies. For climate policy initiative, ‘feasibility of implementation’ had the highest AHP weight (0.45) followed by ‘policy feasibility’ (0.39), and ‘environmental performance’ (0.16).

Positioning for acute respiratory distress in hospitalised infants and children.

Positioning for acute respiratory distress in hospitalised infants and children.

Effect of High Carbon Dioxide Level on Psychological Performance and Arousal Level

本研究は高濃度の二酸化炭素が心理・生理機能へ与える影響について調べた．本研究の被験者は11名の健常な21才から23才の成人女性であった．被験者は実験室にて異なる二酸化炭素濃度条件（大気濃度，2000 ppm，4000 ppm）に45分間曝露された．各心理・生理指標は二酸化炭素曝露の前後にて記録された．計算課題の正解数は二酸化炭素濃度2000 ppmと4000 ppm条件において曝露後で有意に減少した．事象関連電位P300の潜時も2000 ppmと4000 ppm条件曝露後に有意に遅延した．眠気感も高濃度の二酸化炭素曝露後に有意に低下した．以上の結果から，室内における2000 ppm以上の高濃度の二酸化炭素は覚醒と精神作業能を低下させることが示唆された．

Malignant Hyperthermia: A Killer If Ignored

Malignant hypothermia (MH) is a potentially fatal hypermetabolic reaction of skeletal muscle. It is an autosomal dominant disorder that generally occurs in people with RYR1, CACNA1S, or STAC3 mutations. And these genetic abnormalities often cause the imperfection of calcium release channels of skeletal muscle. The incidence of MH among different racial groups across the world ranges from approximately 1:5,000-1:250,000, but there is no national statistic MH incidence in China. It is not clear whether there are racial or regional differences in the incidence, but patients under 18 years old may be more affected. MH can be triggered by anesthetics, or other stimuli, such as strenuous exercise, heat-stroke, and emotional stress. While viral infection, statins, hyperglycemia, and muscle metabolic dysfunctions might accelerate the onset of MH. The onset of MH is insidious and rapid, with the preclinical stage characterized by rigidity of the masseter muscle, a high level of end-tidal carbon dioxide, and a sharp and persistent increase in body temperature. Medical history, family history, clinical presentation, in vitro caffeine-halothane contracture testing (IVCT/CHCT) and genetic testing are commonly diagnostic methods of MH. As soon as the onset of MH is suspected, immediate cessation of exposure to stimuli, call for professional support, and access to dantrolene are the highest priorities. For symptomatic treatment, “5C principles” were summarized as an algorithm to guide clinicians.

Polymeric Composite Reinforced with PET Fiber Waste for Application in Civil Construction as a Cladding Element.

The construction industry contributes enormously to the high levels of carbon dioxide on the planet. For this reason, the sector has been investing in the development of new products that reduce the environmental impact. This study developed a fibrous polymeric composite using industrial residues of polyethylene terephthalate (PET) fibers for application in civil construction as a cladding element. The thermal and morphological characterization of the fiber was performed using Thermogravimetry (TG) and Scanning Electron Microscopy (SEM). Composites with 1, 3, and 5% PET fibers were obtained. Mechanical, morphological properties, chemical resistance, the effect of ultraviolet radiation and water absorption of the composites were evaluated. The results were compared to parameters established by the Brazilian standard NBR 15.575-3. Fibers had a smooth surface but with small surface defects, diameter between 20 and 30 µm and thermal stability up to 325.44 °C. The addition of 5% PET fibers resulted in an increase of more than 300% in the impact resistance of the composites, but with a reduction in the flexural strength. The mechanical and chemical resistance results met the parameters established by the standard used in the study. The degradation chamber test indicated that PET fibers suffered more from exposure to ultraviolet radiation than the polymeric matrix.

Mathematical modeling of oxygen levels in a controlled atmosphere store for preservation of apple fruits

Apple fruit preservation for long periods (up to eight months) needs low temperature, high humidity, low oxygen and high carbon di-oxide levels around the fruits. Controlled Atmosphere (CA) storage chambers can extend the shelf life of fruits by controlling the respiration rates of fruits. To achieve low respiration, low oxygen levels need to be created in the sealed chambers. A pressure swing adsorption nitrogen generator is used to generate 99% pure nitrogen, which is pumped into the sealed fruit chambers after achieving required temperature. Oxygen level of 20.8% is slowly lowered to 1 to 2% level. Storage chamber of 720 m3 is selected to conduct the kinetic study of lowering the oxygen level. Quantity of apples stores per batch is 150 metric tons. Time taken to lower the oxygen to required levels is 24 h. Rate of oxygen reduction is modeled mathematically and fitted to three mathematical equations, viz. exponential, second order polynomial and third order polynomial. Exponential model could explain the behavior with R2 value of 0.966. R2 value of 0.978 found for second order polynomial model. Best fit of predicted and experimental values found with polynomial model of third order with R2 value of 0.998. The modeled data will be useful for prediction of oxygen levels for both controlled atmosphere and modified atmosphere requirements for different fruits.

Reduction of Post-Harvest Injuries Caused by Drosophila suzukii in Some Cultivars of Sweet Cherries Using a High Carbon Dioxide Level and Cold Storage.

Simple SummaryThe spotted-wing Drosophila suzukii is an invasive fruit fly that causes high levels of damage to cherry fruits, which are, economically, a very important crop in the Puglia region. This pest infests mature fruits which are close to harvest, and when additional treatments are not allowed due to residue problems. The effect of infestation is a prolonged post-harvest time and up to 100% crop loss according to our field monitoring. The objective of our study was to find an effective post-harvest management of such infestations. We determined the growth rate of larval D. suzukii in infested fruits which were stored at low temperatures or treated with CO2 at low or room temperature; such post-harvest treatments were also tested in terms of the fruit quality at the end of the storage time, with respect to untreated infested fruits. When fruits were stored at low temperature in the presence of CO2 a consistent inhibition of larval growth was observed, with no apparent decrease of fruit quality parameters. After one month of storage, the quality parameters of treated, infested fruits were similar to the quality parameters of newly harvested fruits and non-infested fruits.Efficient strategies are required in sweet cherry fruits to control the spotted wing drosophila (SWD), Drosophila suzukii, due to its adverse economic effect on farmers. Cold storage (CS) and storage with elevated carbon dioxide (CO2) are environmentally safe approaches for the pest control of stored fresh fruit. These strategies are effective in controlling a wide variety of insect species, without allowing toxic compounds to accumulate. The purpose of this study was to assess the effectiveness of a post-harvest application of CO2 treatment at 50%, cold treatment at 4 °C (CT), and a combination of both (CO2-CT) in controlling the early stages of SWD within four cultivars of freshly harvested cherry fruit, namely “Burlat-Bigarreau”, “Giorgia”, “Ferrovia”, and “Lapins”. In addition, an evaluation of the quality attributes of the cherries (skin firmness, berry firmness, strong soluble material, and titratable acidity) was carried out at harvest and after 10 and 20 days of storage. All treatments significantly reduced the rate of emergence of SWD when compared to the control (untreated cherry at 24 °C), and 100% SWD mortality was obtained in Burlat-Bigarreau (CO2-CT). In addition, over the entire storage time, the quality parameters were preserved in the samples stored at 4 °C and in the samples with combined treatments in comparison with the control.

Reverse weathering may amplify post-Snowball atmospheric carbon dioxide levels

Snowball Earth glaciations are the most extreme climate perturbations recorded in Earth’s history. It has been argued that the termination of these events was characterized by a single rapid transition from near-global ice coverage to an ice-free greenhouse climate state. Notably, this deviates with more extended transition periods of ice sheet waxing and waning typical of Phanerozoic glaciations. Using a coupled mineralogical and Mg and Li isotopic approach, we explore the role that authigenic clay formation within the seafloor may have played on Earth’s climate during deglaciation of the Marinoan Snowball Earth event. Marine authigenic clay formation—a process referred to as reverse weathering—recycles carbon within the ocean–atmosphere system and acts to elevate atmospheric CO2 levels. The results indicate a shift towards more extensive reverse weathering within the uppermost portion of the glaciogenic Nantuo Formation in South China. Carbon cycle modeling indicates that widespread reverse weathering could have driven a protracted (millions of years) carbon dioxide drawdown following high carbon dioxide levels expected during deglaciation.

Prediction of hydrogen-heavy fuel combustion process with water addition in an adapted low speed two stroke diesel engine: Performance improvement

Despite their high thermal efficiency (>50%), large two-stroke (2 T) diesel engines burning very cheap heavy fuel oil (HFO) produce a high level of carbon dioxide (CO2). To achieve the low emission levels of greenhouse gases (GHG) that will be imposed by future legislation, the use of hydrogen (H2) as fuel in 2 T diesel engines is a viable option for reducing or almost eliminate CO2 emissions. In this work, from experimental data and system modelling, an analysis of dual combustion is carried out considering different strategies to supply H2 to the engine and for different H2 fractions in energy basis. Previously, a complete thermodynamic model of a 2 T diesel engine with an innovative scavenging model is developed and validated. The most important drawbacks of this type of engines are controlled in this work using dual combustion and water injection, reducing nitrogen oxides emissions (NOx), self-ignition and combustion knocking. The results show that the developed model matches engine performance data in diesel mode, achieving a higher efficiency and mean effective pressure (MEP) in hydrogen mode of 53% and 14.62 bar respectively.

Towards Healthy Levels of Carbon Dioxide in Schools of the National Oil Company of Abu Dhabi

In their annual indoor air quality assessment for ADNOC Schools, the Abu Dhabi Education Council has reported hazardous levels (∼3000 ppm) of carbon dioxide in fifteen classrooms. Exposure of 5,090 students attending the school for ∼eight hours (typical school day) to such high levels of carbon dioxide would induce adverse health conditions like headaches, drowsiness, and lack of concentration on the short term and serious diseases like asthma and sick building syndrome on the long term. The Health, Safety, and Environment committee of the school has identified clogged air intake vents and dirty AC filters as the main cause of the high carbon dioxide concentrations reported. The outdoor (ambient) carbon dioxide level is measured and has an eight-hour average value of 419 ppm. After cleaning thoroughly, the indoor levels of carbon dioxide, temperature, and relative humidity were monitored simultaneously in each classroom and have average values of ∼1117 ppm, ∼24°C, and ∼37%, respectively. In addition, the average indoor-to-outdoor ratio of carbon dioxide has been improved from 3000 / 419 ≈ 7.2 before cleaning the AC filters to an average ratio of ( 1,117 / 419 ≈ 2.7 ) after cleaning. Thus, ventilation rates in the classrooms monitored in this project are adequate and the corrective actions taken were effective.

High flow nasal oxygen for acute type two respiratory failure: a systematic review

Background: Acute type two respiratory failure (AT2RF) is characterized by high carbon dioxide levels (PaCO 2 >6kPa). Non-invasive ventilation (NIV), the current standard of care, has a high failure rate. High flow nasal therapy (HFNT) has potential additional benefits such as CO 2 clearance, the ability to communicate and comfort. The primary aim of this systematic review is to determine whether HFNT in AT2RF improves 1) PaCO 2, 2) clinical and patient-centred outcomes and 3) to assess potential harms. Methods: We searched EMBASE, MEDLINE and CENTRAL (January 1999-January 2021). Randomised controlled trials (RCTs) and cohort studies comparing HFNT with low flow nasal oxygen (LFO) or NIV were included. Two authors independently assessed studies for eligibility, data extraction and risk of bias. We used Cochrane risk of bias tool for RCTs and Ottawa-Newcastle scale for cohort studies. Results: From 727 publications reviewed, four RCTs and one cohort study (n=425) were included. In three trials of HFNT vs NIV, comparing PaCO 2 (kPa) at last follow-up time point, there was a significant reduction at four hours(1 RCT; HFNT median 6.7, IQR 5.6 - 7.7 vs NIV median 7.6, IQR 6.3 - 9.3) and no significant difference at 24-hours or five days. Comparing HFNT with LFO, there was no significant difference at 30-minutes. There was no difference in intubation or mortality. Conclusions: This review identified a small number of studies with low to very low certainty of evidence. A reduction of PaCO 2 at an early time point of four hours post-intervention was demonstrated in one small RCT. Significant limitations of the included studies were lack of adequately powered outcomes and clinically relevant time-points and small sample size. Accordingly, systematic review cannot recommend the use of HFNT as the initial management strategy for AT2RF and trials adequately powered to detect clinical and patient-relevant outcomes are urgently warranted.