Sample records for in-cabin co2 levels

  1. Photosynthesis and Plant Growth at Elevated Levels of CO_2


    Amane, Makino; Tadahiko, Mae; Department of Applied Plant Science, Graduate School of Agricultural Sciences, Tohoku University; Department of Applied Plant Science, Graduate School of Agricultural Sciences, Tohoku University


    In this review, we discuss the effects of elevated CO_2 levels on photosynthesis in relation to the whole plant growth in terrestrial higher C_3 plants. Short-term CO_2 enrichment stimulates the rate of phtosynthesis. Plant mass is also enhanced by CO_2 enrichment. However, the effects of long-term CO_2 enrichment on photosynthesis are variable. Generally, the prolonged exposure to CO_2 enrichment reduces the initial stimulation of photosynthesis in many spesies, and frequently suppresses pho...

  2. The Relationship Between CO2 Levels and CO2 Related Symptoms Reported on the ISS (United States)

    VanBaalen, M.; Law, J.; Foy, M.; Wear, M. L.; Mason, S.; Mendez, C.; Meyers, V.


    Medical Operations, Toxicology, and the Lifetime Surveillance of Astronaut Health collaborated to assess the association of CO2 levels on board the International Space Station and USOS crew reported symptoms inflight, i.e. headache and vision changes. Private Medical Conference (PMC) documents and the weekly Space Medicine Operations Team (SMOT) Notes were used to provide a robust data set of inflight medical events. All events and non-events were documented independent of CO2 levels and other potential contributors. Average (arithmetic mean) and single point maximum ppCO2 was calculated for the 24 hours and 7 days prior to the PMC or SMOT date and time provided by LSAH. Observations falling within the first 7 days of flight (147) were removed from the datasets analyzed to avoid confounding with Space Adaptation Syndrome. The final analysis was based on 1716 observations. For headache, 46 headaches were observed. CO2 level, age at launch, time inflight, and data source were all significantly associated with headache. In particular, for each 1 mmHg increase in CO2, the odds of a crewmember reporting a headache doubled. For vision changes, 29 reports of vision changes were observed. These observations were not found to be statistically associated with CO2 levels as analyzed. While the incidence of headache has was not high (3%), headaches may be an indicator of underlying increases in intracranial pressure, which may result likely from the synergy between CO2-induced cerebral vasodilatation and decreased venous drainage in microgravity. Vision changes were inconsistently reported and as a result did not align appropriately with the CO2 levels. Further analysis is needed. Our results support ongoing efforts to lower the CO2 exposure limits in spacecraft.

  3. Effective CO2 lifetime and future CO2 levels based on fit function

    Directory of Open Access Journals (Sweden)

    G. R. Sonnemann


    Full Text Available The estimated global CO2 emission rates and the measured atmospheric CO2 concentrations show that only a certain share of the emitted CO2 accumulates in the atmosphere. For given atmospheric emissions of CO2, the effective lifetime determines its accumulation in the atmosphere and, consequently, its impact on the future global warming. We found that on average the inferred effective lifetime of CO2 decreases as its atmospheric concentration increases, reducing the rate of its accumulation in the atmosphere. We derived a power function that fits the varying lifetimes. Based on this fitting function, we calculated the increase of CO2 for different scenarios of future global emission rates.

  4. System-level modeling for geological storage of CO2


    Zhang, Yingqi; Oldenburg, Curtis M.; Finsterle, Stefan; Bodvarsson, Gudmundur S.


    One way to reduce the effects of anthropogenic greenhouse gases on climate is to inject carbon dioxide (CO2) from industrial sources into deep geological formations such as brine formations or depleted oil or gas reservoirs. Research has and is being conducted to improve understanding of factors affecting particular aspects of geological CO2 storage, such as performance, capacity, and health, safety and environmental (HSE) issues, as well as to lower the cost of CO2 capture and related p...

  5. Uncovering China’s transport CO2 emission patterns at the regional level

    International Nuclear Information System (INIS)

    Guo, Bin; Geng, Yong; Franke, Bernd; Hao, Han; Liu, Yaxuan; Chiu, Anthony


    With China’s rapid economic development, its transport sector has experienced a dramatic growth, leading to a large amount of related CO 2 emission. This paper aims to uncover China’s transport CO 2 emission patterns at the regional and provincial level. We first present the CO 2 emission features from transport sector in 30 Chinese provinces, including per capita emissions, emission intensities, and historical evolution of annual CO 2 emission. We then quantify the related driving forces by adopting both period-wise and time-series LMDI analysis. Results indicate that significant regional CO 2 emission disparities exist in China’s transport sector. The eastern region had higher total CO 2 emissions and per capita CO 2 emissions, but lower CO 2 emission intensities in its transport sector. The western region had higher CO 2 emission intensities and experienced a rapid CO 2 emission increase. The CO 2 emission increments in the eastern provinces were mainly contributed by both economic activity effect and population effect, while energy intensity partially offset the emission growth and energy structure had a marginal effect. However, in the central and western provinces, both economic activity effect and energy intensity effect induced the CO 2 emission increases, while the effects from population and energy structure change were limited. - Highlights: • The CO 2 emission features from transport sector in 30 Chinese provinces were presented. • The driving forces of CO 2 emissions from transport sector were quantified. • Regional disparities on China’s transport sector CO 2 emission exist. • Region-specific mitigation policies on transport sector CO 2 emission are needed

  6. Rising CO2 Levels Will Intensify Phytoplankton Blooms in Eutrophic and Hypertrophic Lakes (United States)

    Verspagen, Jolanda M. H.; Van de Waal, Dedmer B.; Finke, Jan F.; Visser, Petra M.; Van Donk, Ellen; Huisman, Jef


    Harmful algal blooms threaten the water quality of many eutrophic and hypertrophic lakes and cause severe ecological and economic damage worldwide. Dense blooms often deplete the dissolved CO2 concentration and raise pH. Yet, quantitative prediction of the feedbacks between phytoplankton growth, CO2 drawdown and the inorganic carbon chemistry of aquatic ecosystems has received surprisingly little attention. Here, we develop a mathematical model to predict dynamic changes in dissolved inorganic carbon (DIC), pH and alkalinity during phytoplankton bloom development. We tested the model in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa at different CO2 levels. The experiments showed that dense blooms sequestered large amounts of atmospheric CO2, not only by their own biomass production but also by inducing a high pH and alkalinity that enhanced the capacity for DIC storage in the system. We used the model to explore how phytoplankton blooms of eutrophic waters will respond to rising CO2 levels. The model predicts that (1) dense phytoplankton blooms in low- and moderately alkaline waters can deplete the dissolved CO2 concentration to limiting levels and raise the pH over a relatively wide range of atmospheric CO2 conditions, (2) rising atmospheric CO2 levels will enhance phytoplankton blooms in low- and moderately alkaline waters with high nutrient loads, and (3) above some threshold, rising atmospheric CO2 will alleviate phytoplankton blooms from carbon limitation, resulting in less intense CO2 depletion and a lesser increase in pH. Sensitivity analysis indicated that the model predictions were qualitatively robust. Quantitatively, the predictions were sensitive to variation in lake depth, DIC input and CO2 gas transfer across the air-water interface, but relatively robust to variation in the carbon uptake mechanisms of phytoplankton. In total, these findings warn that rising CO2 levels may result in a marked intensification of

  7. High sensitivity to chronically elevated CO2 levels in a eurybathic marine sipunculid. (United States)

    Langenbuch, M; Pörtner, H O


    CO2 levels are expected to rise (a) in surface waters of the oceans as atmospheric accumulation continues or (b) in the deep sea, once industrial CO2 dumping is implemented. These scenarios suggest that CO2 will become a general stress factor in aquatic environments. The mechanisms of sensitivity to CO2 as well as adaptation capacity of marine animals are insufficiently understood. Here, we present data obtained in Sipunculus nudus, a sediment-dwelling marine worm that is able to undergo drastic metabolic depression to survive regular exposure to elevated CO2 levels within its natural habitat. We investigated animal survival and the proximate biochemical body composition during long-term CO2 exposure. Results indicate an unexpected and pronounced sensitivity characterized by the delayed onset of enhanced mortality at CO2 levels within the natural range of concentrations. Therefore, the present study contrasts the previously assumed high-CO2 tolerance of animals adapted to temporary hypercapnia. As a consequence, we expect future loss of species and, thereby, detrimental effects on marine benthic ecosystems with as yet poorly defined critical thresholds of long-term tolerance to CO2.

  8. From the low past to the high future: Plant growth across CO2 levels (United States)

    Temme, Andries; Cornwell, Will; Cornelissen, Hans; Aerts, Rien


    In today's atmosphere fossil fuel emissions and land use change since the industrial revolution have increased atmospheric CO2 concentration from 280 ppm to nearly 400 ppm, a value not experienced by plants for over 10 million years. In contrast, over the same period atmospheric CO2 levels have been much lower than preindustrial levels. Plants' recent evolutionary history has thus been under carbon starvation while over the next 90 years atmospheric CO2 is expected to rise to a bountiful ~800 ppm. Plants' response to this rapid increase is likely influenced by their long evolution in low CO2, but this has been hardly studied at all. Very little is known about how plant traits drove carbon cycling in the past and how these relationships may shift going from past to future CO2.In a climate chamber experiment we germinated and grew seedlings of 30 species (C3, C4, woody, herbaceous) at past low CO2 (150ppm), ambient CO2, and future high CO2(750ppm). Our aim was to understand how plant traits are affected by CO2 and if and why winners and losers in terms of growth performance shift going from past to future CO2 concentrations. Results show a great effect of low and high CO2 on specific leaf area, biomass and allocation shifts above and belowground but mixed results in patterns between species and plant types. Ongoing work focuses on leaf level chemistry and photosynthesis and the interaction between CO2 and drought stress with promising initial results.

  9. Elevated atmospheric CO2 levels affect community structure of rice root-associated bacteria

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    Kiwamu eMinamisawa


    Full Text Available A number of studies have shown that elevated atmospheric CO2 ([CO2] affects rice yields and grain quality. However, the responses of root-associated bacteria to [CO2] elevation have not been characterized in a large-scale field study. We conducted a free-air CO2 enrichment (FACE experiment (ambient + 200 μmol⋅mol−1 using three rice cultivars (Akita 63, Takanari, and Koshihikari and two experimental lines of Koshihikari (chromosome segment substitution and near-isogenic lines to determine the effects of [CO2] elevation on the community structure of rice root-associated bacteria. Microbial DNA was extracted from rice roots at the panicle formation stage and analyzed by pyrosequencing the bacterial 16S rRNA gene to characterize the members of the bacterial community. Principal coordinate analysis of a weighted UniFrac distance matrix revealed that the community structure was clearly affected by elevated [CO2]. The predominant community members at class level were Alpha-, Beta-, and Gamma-proteobacteria in the control (ambient and FACE plots. The relative abundance of Methylocystaceae, the major methane-oxidizing bacteria in rice roots, tended to decrease with increasing [CO2] levels. Quantitative PCR revealed a decreased copy number of the methane monooxygenase (pmoA gene and increased methyl coenzyme M reductase (mcrA in elevated [CO2]. These results suggest elevated [CO2] suppresses methane oxidation and promotes methanogenesis in rice roots; this process affects the carbon cycle in rice paddy fields.

  10. System-level modeling for economic evaluation of geological CO2 storage in gas reservoirs

    International Nuclear Information System (INIS)

    Zhang, Yingqi; Oldenburg, Curtis M.; Finsterle, Stefan; Bodvarsson, Gudmundur S.


    One way to reduce the effects of anthropogenic greenhouse gases on climate is to inject carbon dioxide (CO 2 ) from industrial sources into deep geological formations such as brine aquifers or depleted oil or gas reservoirs. Research is being conducted to improve understanding of factors affecting particular aspects of geological CO 2 storage (such as storage performance, storage capacity, and health, safety and environmental (HSE) issues) as well as to lower the cost of CO 2 capture and related processes. However, there has been less emphasis to date on system-level analyses of geological CO 2 storage that consider geological, economic, and environmental issues by linking detailed process models to representations of engineering components and associated economic models. The objective of this study is to develop a system-level model for geological CO 2 storage, including CO 2 capture and separation, compression, pipeline transportation to the storage site, and CO 2 injection. Within our system model we are incorporating detailed reservoir simulations of CO 2 injection into a gas reservoir and related enhanced production of methane. Potential leakage and associated environmental impacts are also considered. The platform for the system-level model is GoldSim [GoldSim User's Guide. GoldSim Technology Group; 2006,]. The application of the system model focuses on evaluating the feasibility of carbon sequestration with enhanced gas recovery (CSEGR) in the Rio Vista region of California. The reservoir simulations are performed using a special module of the TOUGH2 simulator, EOS7C, for multicomponent gas mixtures of methane and CO 2 . Using a system-level modeling approach, the economic benefits of enhanced gas recovery can be directly weighed against the costs and benefits of CO 2 injection

  11. Growth response of Spirulina platensis PCC9108 to elevated CO2 levels and flue gas

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    Seyedmahdi Hoseini


    Full Text Available Introduction: Because their ability to capture CO2, photosynthetical microorganisms have some advantages to CO2 mitigation from high CO2 streams such as flue gases and they can use CO2 as carbon source. Recently, experts have made efforts to exploit microorganisms intended for recovering CO2 from power plants. Materials and methods: To achieve this purpose, we studied the growth response of the cyanobacterium Spirulina platensis PCC9108 under different concentrations of carbon dioxide (ranging from 0.036% to 10% and flue gas in a bench-scale system. Preparation of different concentrations of CO2 and injection into Erlenmeyer flasks was performed by a system including air compressor, CO2 capsule, pressure gauge and flow meter. Results: The main goal of studying this paper is a survey of organism's potential to grow by generated CO2 from flue gas of power plant. It already had the potential and highest biomass production recorded at 8% CO2 (v/v. Also we proved that S.platensis PCC9108 can be grown under flue gas, although biomass production decreased fairly. Total lipid content of algae interestingly enhanced with elevated CO2 levels from ambient air to 4% and 6% which ranged from 14.5 to 15.8 and 16 dry weight (wt. % respectively. In contrast, total protein content illustrated no difference between all treatment and its value was about 46 wt.%. Discussion and conclusion: The results of present study suggested that understudied S.platensis PCC9108 is appropriate for mitigating CO2 because of its carbon fixation ability. Also due to its high protein content, this cyanobacterium is a good candidate to produce SCP (single cell protein.

  12. TransCom 3: Seasonal CO2 Flux Estimates from Atmospheric Inversions (Level 2) (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides model outputs and seasonal mean CO2 fluxes from the Atmospheric Carbon Cycle Inversion Intercomparison (TransCom 3), Level 2...

  13. TransCom 3: Seasonal CO2 Flux Estimates from Atmospheric Inversions (Level 2) (United States)

    National Aeronautics and Space Administration — This data set provides model outputs and seasonal mean CO2 fluxes from the Atmospheric Carbon Cycle Inversion Intercomparison (TransCom 3), Level 2 inversion...

  14. Community-level sensitivity of a calcifying ecosystem to acute in situ CO2 enrichment

    KAUST Repository

    Burdett, HL


    The rate of change in ocean carbonate chemistry is a vital determinant in the magnitude of effects observed. Benthic marine ecosystems are facing an increasing risk of acute CO2 exposure that may be natural or anthropogenically derived (e.g. engineering and industrial activities). However, our understanding of how acute CO2 events impact marine life is restricted to individual organisms, with little understanding for how this manifests at the community level. Here, we investigated in situ the effect of acute CO2 enrichment on the coralline algal ecosystem—a globally ubiquitous, ecologically and economically important habitat, but one which is likely to be sensitive to CO2 enrichment due to its highly calcified reef-like structures engineered by coralline algae. Most notably, we observed a rapid community-level shift to favour net dissolution rather than net calcification. Smaller changes from net respiration to net photosynthesis were also observed. There was no effect on the net flux of DMS/DMSP (algal secondary metabolites), nor on the nutrients nitrate and phosphate. Following return to ambient CO2 levels, only a partial recovery was seen within the monitoring timeframe. This study highlights the sensitivity of biogenic carbonate marine communities to acute CO2 enrichment and raises concerns over the capacity for the system to ‘bounce back’ if subjected to repeated acute high-CO2 events.

  15. CO2 and nutrient-driven changes across multiple levels of organization in Zostera noltii ecosystems (United States)

    Martínez-Crego, B.; Olivé, I.; Santos, R.


    Increasing evidence emphasizes that the effects of human impacts on ecosystems must be investigated using designs that incorporate the responses across levels of biological organization as well as the effects of multiple stressors. Here we implemented a mesocosm experiment to investigate how the individual and interactive effects of CO2 enrichment and eutrophication scale-up from changes in primary producers at the individual (biochemistry) or population level (production, reproduction, and/or abundance) to higher levels of community (macroalgae abundance, herbivory, and global metabolism), and ecosystem organization (detritus release and carbon sink capacity). The responses of Zostera noltii seagrass meadows growing in low- and high-nutrient field conditions were compared. In both meadows, the expected CO2 benefits on Z. noltii leaf production were suppressed by epiphyte overgrowth, with no direct CO2 effect on plant biochemistry or population-level traits. Multi-level meadow response to nutrients was faster and stronger than to CO2. Nutrient enrichment promoted the nutritional quality of Z. noltii (high N, low C : N and phenolics), the growth of epiphytic pennate diatoms and purple bacteria, and shoot mortality. In the low-nutrient meadow, individual effects of CO2 and nutrients separately resulted in reduced carbon storage in the sediment, probably due to enhanced microbial degradation of more labile organic matter. These changes, however, had no effect on herbivory or on community metabolism. Interestingly, individual effects of CO2 or nutrient addition on epiphytes, shoot mortality, and carbon storage were attenuated when nutrients and CO2 acted simultaneously. This suggests CO2-induced benefits on eutrophic meadows. In the high-nutrient meadow, a striking shoot decline caused by amphipod overgrazing masked the response to CO2 and nutrient additions. Our results reveal that under future scenarios of CO2, the responses of seagrass ecosystems will be complex and

  16. Relationship between sea level and climate forcing by CO2 on geological timescales. (United States)

    Foster, Gavin L; Rohling, Eelco J


    On 10(3)- to 10(6)-year timescales, global sea level is determined largely by the volume of ice stored on land, which in turn largely reflects the thermal state of the Earth system. Here we use observations from five well-studied time slices covering the last 40 My to identify a well-defined and clearly sigmoidal relationship between atmospheric CO(2) and sea level on geological (near-equilibrium) timescales. This strongly supports the dominant role of CO(2) in determining Earth's climate on these timescales and suggests that other variables that influence long-term global climate (e.g., topography, ocean circulation) play a secondary role. The relationship between CO(2) and sea level we describe portrays the "likely" (68% probability) long-term sea-level response after Earth system adjustment over many centuries. Because it appears largely independent of other boundary condition changes, it also may provide useful long-range predictions of future sea level. For instance, with CO(2) stabilized at 400-450 ppm (as required for the frequently quoted "acceptable warming" of 2 °C), or even at AD 2011 levels of 392 ppm, we infer a likely (68% confidence) long-term sea-level rise of more than 9 m above the present. Therefore, our results imply that to avoid significantly elevated sea level in the long term, atmospheric CO(2) should be reduced to levels similar to those of preindustrial times.

  17. Future Climate CO2 Levels Mitigate Stress Impact on Plants: Increased Defense or Decreased Challenge? (United States)

    AbdElgawad, Hamada; Zinta, Gaurav; Beemster, Gerrit T S; Janssens, Ivan A; Asard, Han


    Elevated atmospheric CO2 can stimulate plant growth by providing additional C (fertilization effect), and is observed to mitigate abiotic stress impact. Although, the mechanisms underlying the stress mitigating effect are not yet clear, increased antioxidant defenses, have been held primarily responsible (antioxidant hypothesis). A systematic literature analysis, including "all" papers [Web of Science (WoS)-cited], addressing elevated CO2 effects on abiotic stress responses and antioxidants (105 papers), confirms the frequent occurrence of the stress mitigation effect. However, it also demonstrates that, in stress conditions, elevated CO2 is reported to increase antioxidants, only in about 22% of the observations (e.g., for polyphenols, peroxidases, superoxide dismutase, monodehydroascorbate reductase). In most observations, under stress and elevated CO2 the levels of key antioxidants and antioxidant enzymes are reported to remain unchanged (50%, e.g., ascorbate peroxidase, catalase, ascorbate), or even decreased (28%, e.g., glutathione peroxidase). Moreover, increases in antioxidants are not specific for a species group, growth facility, or stress type. It seems therefore unlikely that increased antioxidant defense is the major mechanism underlying CO2-mediated stress impact mitigation. Alternative processes, probably decreasing the oxidative challenge by reducing ROS production (e.g., photorespiration), are therefore likely to play important roles in elevated CO2 (relaxation hypothesis). Such parameters are however rarely investigated in connection with abiotic stress relief. Understanding the effect of elevated CO2 on plant growth and stress responses is imperative to understand the impact of climate changes on plant productivity.

  18. Physiological responses of the calcifying rhodophyte, Corallina officinalis (L.), to future CO2 levels


    Hofmann, Laurie C.; Yildiz, Gamze; Hanelt, Dieter; Bischof, Kai


    Future atmospheric CO2 levels will most likely have complex consequences for marine organisms, particulary photosynthetic calcifying organisms. Corallina officinalis L. is an erect calcifying macroalga found in the inter- and subtidal regions of temperate rocky coastlines and provides important substrate and refugia for marine meiofauna. The main goal of the current study was to determine the physiological responses of C. officinalis to increased CO2 concentrations expected to occur within th...

  19. Gas Exchange Characteristics in Tectona grandis L. Clones under Varying Concentrations of CO2 Levels

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    S. Saravanan


    Full Text Available The Institute of Forest Genetics and Tree Breeding, Coimbatore, India functioning under the Indian Council of Forestry Research and Education, Dehara Dun, has a long term systematic tree improvement program for Tectona grandis aimed to enhancing productivity and screening of clones for site specific. In the process, twenty clones of T. grandis L. were studied for the physiological parameters and water use efficiency with reference to the elevated CO2 levels. CO2 enrichment studies in special chambers help in understanding the changes at individual level, and also at physiological, biochemical and genetic level. It also provides valuable information for establishing plantations at different geographic locations. Considerable variations were observed when the selected 20 clones of T. grandis were subjected to physiological studies under elevated CO2 conditions (600 and 900 mol mol-1. Eight clones exhibited superior growth coupled with favorable physiological characteristics including high photosynthetic rate, carboxylation and water use efficiency under elevated CO2 levels. Clones with minimal variation in physiological characteristics under elevated levels of CO2 suggest their ability to overcome physiological stresses and adapt to varying climatic conditions.

  20. An anti-herbivore defense mutualism under elevated CO2 levels

    Energy Technology Data Exchange (ETDEWEB)

    Marks, S.; Lincoln, D.E. (Winthrop Univ., Rock Hill, SC (United States))


    Previous studies have shown that insects typically consume more when fed leaf tissue grown under CO2 enrichment, but with few negative effects on growth. On the other hand, Lepidopteran larvae fed tissue infected with Balansiae fungal endophytes (which produce toxic alkaloids) typically eat less but suffer negative effects on growth and survival. This study was carried out to see how these two factors would interact to affect consumption and growth of Fall Armyworm larvae (Spodoptera frugiperda). Infected and uninfected ramets of a single genotype of tall fescue (Festuca arundinacea) were grown under CO2 concentrations of 400 and 700 ul/L. Larvae had increased relative growth in the high CO2 treatment, but decreased growth when fed infected tissue. Relative consumption of leaf tissue was greater in the high CO2 treatment, but was not effected by infection. CO2 level, infection, and their interaction all significantly reduced the efficiency of conversion of food ingested (ECI). It appears that tall fescue may not be as well defended against herbivores under CO2 enrichment, although insects may still avoid and be negatively effected by endophyte infected plants.

  1. Response of Photosynthesis and Yield of Sweetpotato and Peanut to Super-optimal CO2 levels (United States)

    Bonsi, C.; Bullard, J.; Hileman, D.; Mortley, D.; Hill, J.; Hill, W.; Morrris, C.

    The fate of persons involved in long-term space travel and habitation will depend greatly on the ability to provide food and a livable environment for them In the National Aeronautics and Space Administration NASA Advanced Life Support ALS program photosynthesis of higher plants will be utilized to provide food and oxygen while removing carbon dioxide produced by humans and other heterotrophs as well as transpiring water that can be recycled for drinking This plant-mediated process is collectively referred to as Bioregenerative Life Support Carbon dioxide concentrations on board a space shuttle cabin atmosphere range between 4000 and 6000 mu mol mol -1 CO 2 but with large crews may exceed 10 000- mu mol mol -1 CO 2 Thus it is critical to evaluate the responses of candidate crops to super optimal levels of CO 2 Soybean and potato have been exposed to CO 2 concentrations up to 5000 and 10 000- mu mol mol -1 Very little research has been published about the effects of super-optimal CO 2 levels on sweetpotato and peanut growth and physiology thus indicating a need for extensive research on these plants The aim of this study was to evaluate the effects of super-optimal CO 2 enrichment on growth of TU-82-155 sweetpotato and Georgia Red peanut in a Microporous Tube Membrane MPT using Turface Media and Nutrient Film Technique NFT nutrient delivery systems Sweetpotato Ipomoea batatas L Lam and peanut Arachis hypogaea L were exposed to three CO 2 levels of 400

  2. CO2 sequestration in two mediterranean dune areas subjected to a different level of anthropogenic disturbance (United States)

    Bonito, Andrea; Ricotta, Carlo; Iberite, Mauro; Gratani, Loretta; Varone, Laura


    Coastal sand dunes are among the most threatened habitats, especially in the Mediterranean Basin, where the high levels of human pressure impair the presence of plant species, putting at risk the maintenance of the ecosystem services, such as CO2 sequestration provided by these habitats. The aim of this study was to analyze how disturbance-induced changes in plant species abundance patterns account for variations in annual CO2 sequestration flow (CS) of Mediterranean sand dune areas. Two sites characterized by a high (site HAD) and a lower (site LAD) anthropogenic disturbance level were selected. At both sites, plant species number, cover, height and CS based on net photosynthesis measurements were sampled. At the plant species level, our results highlighted that Ammophila arenaria and Pancratium maritimum, had a key role in CS. Moreover, the results revealed a patchy species assemblage in both sites. In particular, HAD was characterized by a higher extension of the anthropogenic aphytoic zone (64% of the total transect length) than LAD. In spite of the observed differences in plant species composition, there were not significant differences between HAD and LAD in structural and functional traits, such as plant height and net photosynthesis. As a consequence, HAD and LAD had a similar CS (443 and 421 Mg CO2 ha-1 y-1, respectively). From a monetary point of view, our estimates based on the social costs of carbon revealed that the flow of sequestered CO2 valued on an average 3181 ± 114 ha-1 year-1 (mean value for the two sites). However, considering also the value of the CO2 negative flow related to loss of vegetated area, the annual net benefit arising from CO2 sequestration amounted to 1641 and 1772 for HAD and LAD, respectively. Overall, the results highlighted the importance to maximize the efforts to preserve dune habitats by applying an effective management policy, which could allow maintaining also a regulatory ecosystem service such as CO2 sequestration.

  3. Low atmospheric CO2 levels during the Permo- Carboniferous glaciation inferred from fossil lycopsids (United States)

    Beerling, D. J.


    Earth history was punctuated during the Permo-Carboniferous [300–250 million years (Myr) ago] by the longest and most severe glaciation of the entire Phanerozoic Eon. But significant uncertainty surrounds the concentration of CO2 in the atmosphere through this time interval and therefore its role in the evolution of this major prePleistocene glaciation. Here, I derive 24 Late Paleozoic CO2 estimates from the fossil cuticle record of arborsecent lycopsids of the equatorial Carboniferous and Permian swamp communities. Quantitative calibration of Late Carboniferous (330–300 Myr ago) and Permian (270–260 Myr ago) lycopsid stomatal indices yield average atmospheric CO2 concentrations of 344 ppm and 313 ppm, respectively. The reconstructions show a high degree of self-consistency and a degree of precision an order of magnitude greater than other approaches. Low CO2 levels during the Permo-Carboniferous glaciation are in agreement with glaciological evidence for the presence of continental ice and coupled models of climate and ice-sheet growth on Pangea. Moreover, the Permian data indicate atmospheric CO2 levels were low 260 Myr ago, by which time continental deglaciation was already underway. Positive biotic feedbacks on climate, and geotectonic events, therefore are implicated as mechanisms underlying deglaciation. PMID:12235372

  4. Effects of ERV Filter Degradation on Indoor CO2 Levels of a Classroom

    Directory of Open Access Journals (Sweden)

    Jae-Sol Choi


    Full Text Available Energy recovery ventilators (ERVs are widely used to reduce energy losses caused by ventilation and improve indoor air quality for recently-constructed buildings. It is important for spaces with high occupancy density and longer residence times, such as classrooms. In classrooms, the ERV size is typically estimated by the target number of students in the design phase, but the design air volume flow rates (m3/h of the ERV can decrease over time owing to filter degradation such as increased dust loading. In this study, field tests are conducted in a classroom to investigate filter degradation through a visual inspection and by measuring the air volume flow rates at the diffusers connected to the ERV. In addition, variations in carbon dioxide (CO2 concentrations are also measured to verify the effects of filter degradation on the indoor CO2 levels over the entire test period, which includes filter replacement, as well. As the tests are conducted during classes, several adjusting methodologies are proposed to match the different test conditions. The results show that the total air volume flow rate of the ERV increases after the filter replacement (546 to 766 m3/h, but it again decreases as time elapses (659 m3/h. Accordingly, the indoor CO2 concentration decreases after the filter replacement by more than 300 ppm (1404 to 1085 ppm, clearly showing the effect of filter degradation. However, this CO2 concentration remains similar for four months after the replacement, and the total air volume rate decreases again. An interpretation is made using computational fluid dynamics analysis that the measured CO2 concentrations are affected by airflow patterns. The airflow in the cooling system may dilute CO2 concentrations at the measuring location. Thus, periodic filter replacement and management are important to ensure the desired ERV air volume rates and consequently the desired indoor CO2 concentrations.

  5. Elevated CO2 stimulates marsh elevation gain, counterbalancing sea-level rise (United States)

    Langley, J.A.; McKee, K.L.; Cahoon, D.R.; Cherry, J.A.; Megonigala, J.P.


    Tidal wetlands experiencing increased rates of sea-level rise (SLR) must increase rates of soil elevation gain to avoid permanent conversion to open water. The maximal rate of SLR that these ecosystems can tolerate depends partly on mineral sediment deposition, but the accumulation of organic matter is equally important for many wetlands. Plant productivity drives organic matter dynamics and is sensitive to global change factors, such as rising atmospheric CO2 concentration. It remains unknown how global change will influence organic mechanisms that determine future tidal wetland viability. Here, we present experimental evidence that plant response to elevated atmospheric [CO2] stimulates biogenic mechanisms of elevation gain in a brackish marsh. Elevated CO2 (ambient + 340 ppm) accelerated soil elevation gain by 3.9 mm yr−1in this 2-year field study, an effect mediated by stimulation of below-ground plant productivity. Further, a companion greenhouse experiment revealed that the CO2 effect was enhanced under salinity and flooding conditions likely to accompany future SLR. Our results indicate that by stimulating biogenic contributions to marsh elevation, increases in the greenhouse gas, CO2, may paradoxically aid some coastal wetlands in counterbalancing rising seas.

  6. Assessment of CO 2 emission level in urban transport of Mekelle ...

    African Journals Online (AJOL)

    Transport plays a crucial role in accelerating development and improving quality of life by allowing ease transfer of people, goods and services. It is also one of the important preconditions for achieving developmental goals. This study therefore intends to assess the level of CO2 emissions in urban transport of Mekelle city.


    African Journals Online (AJOL)



    Nov 6, 2016 ... Abstract. Transport plays a crucial role in accelerating development and improving quality of life by allowing ease transfer of people, goods and services. It is also one of the important preconditions for achieving developmental goals. This study therefore intends to assess the level of CO2 emissions in urban ...

  8. Effect of CO_2 levels on nutrient content of lettuce and radish (United States)

    McKeehen, J. D.; Smart, D. J.; Mackowiak, C. L.; Wheeler, R. M.; Nielsen, S. S.

    Atmospheric carbon-dioxide enrichment is known to affect the yield of lettuce and radish grown in controlled environments, but little is known about CO_2 enrichment effects on the chemical composition of lettuce and radish. These crops are useful model systems for a Controlled Ecological Life-Support System (CELSS), largely because of their relatively short production cycles. Lettuce (Lactuca sativa L.) cultivar `Waldmann's Green' and radish (Raphanus sativus L.) cultivar `Giant White Globe' were grown both in the field and in controlled environments, where hydroponic nutrient solution, light, and temperature were regulated, and where CO_2 levels were controlled at 400, 1000, 5000, or 10,000 ppm. Plants were harvested at maturity, dried, and analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate N, free sugars, starch, total dietary fiber, and minerals. Total N, protein N, nonprotein N (NPN), and nitrate N generally increased for radish roots and lettuce leaves when grown under growth chamber conditions compared to field conditions. The nitrate-N level of lettuce leaves, as a percentage of total NPN, decreased with increasing levels of CO_2 enrichment. The ash content of radish roots and of radish and lettuce leaves decreased with increasing levels of CO_2 enrichment. The levels of certain minerals differed between field- and chamber-grown materials, including changes in the calcium (Ca) and phosphorus (P) contents of radish roots and lettuce leaves, resulting in reduced Ca/P ratio for chamber-grown materials. The free-sugar contents were similar between the field and chamber-grown lettuce leaves, but total dietary fiber content was much higher in the field-grown plant material. The starch content of growth-chamber lettuce increased with CO_2 level.

  9. CO2 Fluxes Monitoring at the Level of Field Agroecosystem in Moscow Region of Russia (United States)

    Meshalkina, Joulia; Mazirov, Ilya; Samardzic, Miljan; Yaroslavtsev, Alexis; Valentini, Riccardo; Vasenev, Ivan


    The Central Russia is still one of the less GHG-investigated European areas especially in case of agroecosystem-level carbon dioxide fluxes monitoring by eddy covariance method. The eddy covariance technique is a statistical method to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The major assumption of the metod is that measurements at a point can represent an entire upwind area. Eddy covariance researches, which could be considered as repeated for the same area, are very rare. The research has been carried out on the Precision Farming Experimental Field of the Russian Timiryazev State Agricultural University (Moscow, Russia) in 2013 under the support of RF Government grant No. 11.G34.31.0079. Arable derno-podzoluvisls have around 1 The results have shown high daily and seasonal dynamic of agroecosystem CO2 emission. Sowing activates soil microbiological activity and the average soil CO2 emission and adsorption are rising at the same time. CO2 streams are intensified after crop emerging from values of 3 to 7 μmol/s-m2 for emission, and from values of 5 to 20 μmol/s-m2 for adsorption. Stabilization of the flow has come at achieving plants height of 10-12 cm. The vegetation period is characterized by high average soil CO2 emission and adsorption at the same time, but the adsorption is significantly higher. The resulted CO2 absorption during the day is approximately 2-5 times higher than emissions at night. For example, in mid-June, the absorption value was about 0.45 mol/m2 during the day-time, and the emission value was about 0.1 mol/m2 at night. After harvesting CO2 emission is becoming essentially higher than adsorption. Autumn and winter data are fluctuate around zero, but for some periods a small predominance of CO2 emissions over the absorption may be observed. The daily dynamics of CO2 emissions depends on the air temperature with the correlation coefficient changes between 0.4 and 0.8. Crop stage, agrotechnological

  10. Tidal marsh plant responses to elevated CO2 , nitrogen fertilization, and sea level rise. (United States)

    Adam Langley, J; Mozdzer, Thomas J; Shepard, Katherine A; Hagerty, Shannon B; Patrick Megonigal, J


    Elevated CO2 and nitrogen (N) addition directly affect plant productivity and the mechanisms that allow tidal marshes to maintain a constant elevation relative to sea level, but it remains unknown how these global change drivers modify marsh plant response to sea level rise. Here we manipulated factorial combinations of CO2 concentration (two levels), N availability (two levels) and relative sea level (six levels) using in situ mesocosms containing a tidal marsh community composed of a sedge, Schoenoplectus americanus, and a grass, Spartina patens. Our objective is to determine, if elevated CO2 and N alter the growth and persistence of these plants in coastal ecosystems facing rising sea levels. After two growing seasons, we found that N addition enhanced plant growth particularly at sea levels where plants were most stressed by flooding (114% stimulation in the + 10 cm treatment), and N effects were generally larger in combination with elevated CO2 (288% stimulation). N fertilization shifted the optimal productivity of S. patens to a higher sea level, but did not confer S. patens an enhanced ability to tolerate sea level rise. S. americanus responded strongly to N only in the higher sea level treatments that excluded S. patens. Interestingly, addition of N, which has been suggested to accelerate marsh loss, may afford some marsh plants, such as the widespread sedge, S. americanus, the enhanced ability to tolerate inundation. However, if chronic N pollution reduces the availability of propagules of S. americanus or other flood-tolerant species on the landscape scale, this shift in species dominance could render tidal marshes more susceptible to marsh collapse. © 2013 Blackwell Publishing Ltd.

  11. Sea level fall during glaciation stabilized atmospheric CO2by enhanced volcanic degassing. (United States)

    Hasenclever, Jörg; Knorr, Gregor; Rüpke, Lars H; Köhler, Peter; Morgan, Jason; Garofalo, Kristin; Barker, Stephen; Lohmann, Gerrit; Hall, Ian R


    Paleo-climate records and geodynamic modelling indicate the existence of complex interactions between glacial sea level changes, volcanic degassing and atmospheric CO 2 , which may have modulated the climate system's descent into the last ice age. Between ∼85 and 70 kyr ago, during an interval of decreasing axial tilt, the orbital component in global temperature records gradually declined, while atmospheric CO 2 , instead of continuing its long-term correlation with Antarctic temperature, remained relatively stable. Here, based on novel global geodynamic models and the joint interpretation of paleo-proxy data as well as biogeochemical simulations, we show that a sea level fall in this interval caused enhanced pressure-release melting in the uppermost mantle, which may have induced a surge in magma and CO 2 fluxes from mid-ocean ridges and oceanic hotspot volcanoes. Our results reveal a hitherto unrecognized negative feedback between glaciation and atmospheric CO 2 predominantly controlled by marine volcanism on multi-millennial timescales of ∼5,000-15,000 years.

  12. In-Cabin Air Quality during Driving and Engine Idling in Air-Conditioned Private Vehicles in Hong Kong

    Directory of Open Access Journals (Sweden)

    Natasha Maria Barnes


    Full Text Available Many people spend lengthy periods each day in enclosed vehicles in Hong Kong. However, comparably limited data is available about in-cabin air quality in air-conditioned private vehicles, and the car usage that may affect the air quality. Fifty-one vehicles were tested for particulate matter (PM0.3 and PM2.5, total volatile organic compounds (TVOCs, carbon monoxide (CO, carbon dioxide (CO2, airborne bacteria, and fungi levels during their routine travel journey. Ten of these vehicles were further examined for PM0.3, PM2.5, TVOCs, CO, and CO2 during engine idling. In general, during driving PM2.5 levels in-cabin reduced overtime, but not PM0.3. For TVOCs, 24% vehicles exceeded the recommended Indoor Air Quality (IAQ level in offices and public places set by the Hong Kong Environmental Protection Department. The total volatile organic compounds (TVOC concentration positively correlated with the age of the vehicle. Carbon monoxide (CO levels in all of the vehicles were lower than the IAQ recommendation, while 96% vehicles exceeded the recommended CO2 level of 1000 ppmv; 16% vehicles >5000 ppmv. Microbial counts were relatively low. TVOCs levels at idle engine were higher than that during driving. Although the time we spend in vehicles is short, the potential exposure to high levels of pollutants should not be overlooked.

  13. Statistical Evaluation of the Emissions Level Of CO, CO2 and HC Generated by Passenger Cars

    Directory of Open Access Journals (Sweden)

    Claudiu Ursu


    Full Text Available This paper aims to make an evaluation of differences emission level of CO, CO2 and HC generated by passenger cars in different walking regimes and times, to identify measures of reducing pollution. Was analyzed a sample of Dacia Logan passenger cars (n = 515, made during the period 2004-2007, equipped with spark ignition engines, assigned to emission standards EURO 3 (E3 and EURO4 (E4. These cars were evaluated at periodical technical inspection (ITP by two times in the two walk regimes (slow idle and accelerated idle. Using the t test for paired samples (Paired Samples T Test, the results showed that there are significant differences between emissions levels (CO, CO2, HC generated by Dacia Logan passenger cars at both assessments, and regression analysis showed that these differences are not significantly influenced by turnover differences.

  14. Enhanced abundance of tintinnids under elevated CO2 level from coastal Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Biswas, H.; Gadi, S.D.; Venkataramana, V.; Bharathi, M.D.; Priyan, R.K.; Manjari, D.T.; DileepKumar, M.

    College of Arts, Science and Commerce for Women, Nuvem, Goa – 403 601, India 3 National Institute of Oceanography, Doan Paula, Goa 43004, India Address for correspondence: Dr. Haimanti Biswas, Regional Center, National Institute of Oceanography, 176... group. The present study was conducted to understand the responses of microzooplankton and phytoplankton community and their interactive effects under future predicted CO 2 level. Methods Between May 20 th and June 1 st 2010 surface seawater...

  15. Molecular level investigation of CH4 and CO2 adsorption in hydrated Ca-Montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mal Soon; McGrail, Bernard P.; Rousseau, Roger J.; Glezakou, Vassiliki-Alexandra


    We have studied the mechanism of intercalation and methane adsorption from a H2O/CH4/CO2 mixture on a prototypical shale component, Ca-montmorillonite. We employed ab initio molecular dynamics simulations at 323 K and 90 bar to obtain molecular level information of adsorption energetics, speciation, and structural and thermodynamic properties. Interaction of CH4 with surface Lewis acidic sites (Ca2+, surface OH) results in large induced dipoles (~1 D) that lead to relatively strong adsorption energies that level off once a full CH4 layer is formed. Intercalated CH4, also exhibits induced dipoles at low hydration levels, when the interaction with Ca2+ cations are less hindered. CO2 displaces CH4 in the coordination sphere of the cations (in the interlayer) or in the surface, thereby driving CH4 extraction. Our simulations indicate that there is a Goldilocks pressure range (~60-100 bar) where scCO2 –facilitated CH4 extraction will be maximized.

  16. CO2-level Dependent Effects of Ocean Acidification on Squid, Doryteuthis pealeii, Early Life History

    KAUST Repository

    Zakroff, Casey J.


    Ocean acidification is predicted to lead to global oceanic decreases in pH of up to 0.3 units within the next 100 years. However, those levels are already being reached currently in coastal regions due to natural CO2 variability. Squid are a vital component of the pelagic ecosystem, holding a unique niche as a highly active predatory invertebrate and major prey stock for upper trophic levels. This study examined the effects of a range of ocean acidification regimes on the early life history of a coastal squid species, the Atlantic longfin squid, Doryteuthis pealeii. Eggs were raised in a flow-through ocean acidification system at CO2 levels ranging from ambient (400ppm) to 2200ppm. Time to hatching, hatching efficiency, and hatchling mantle lengths, yolk sac sizes, and statoliths were all examined to elucidate stress effects. Delays in hatching time of at least a day were seen at exposures above 1300ppm in all trials under controlled conditions. Mantle lengths were significantly reduced at exposures above 1300 ppm. Yolk sac sizes varied between CO2 treatments, but no distinct pattern emerged. Statoliths were increasingly porous and malformed as CO2 exposures increased, and were significantly reduced in surface area at exposures above 1300ppm. Doryteuthis pealeii appears to be able to withstand acidosis stress without major effects up to 1300ppm, but is strongly impacted past that threshold. Since yolk consumption did not vary among treatments, it appears that during its early life stages, D. pealeii reallocates its available energy budget away from somatic growth and system development in order to mitigate the stress of acidosis.

  17. Quantification of fossil fuel CO2 at the building/street level for large US cities (United States)

    Gurney, K. R.; Razlivanov, I. N.; Song, Y.


    Quantification of fossil fuel CO2 emissions from the bottom-up perspective is a critical element in emerging plans on a global, integrated, carbon monitoring system (CMS). A space/time explicit emissions data product can act as both a verification and planning system. It can verify atmospheric CO2 measurements (in situ and remote) and offer detailed mitigation information to management authorities in order to optimize the mix of mitigation efforts. Here, we present the Hestia Project, an effort aimed at building a high resolution (eg. building and road link-specific, hourly) fossil fuel CO2 emissions data product for the urban domain as a pilot effort to a CMS. A complete data product has been built for the city of Indianapolis and preliminary quantification has been completed for Los Angeles and Phoenix (see figure). The effort in Indianapolis is now part of a larger effort aimed at a convergent top-down/bottom-up assessment of greenhouse gas emissions, called INFLUX. Our urban-level quantification relies on a mixture of data and modeling structures. We start with the sector-specific Vulcan Project estimate at the mix of geocoded and county-wide levels. The Hestia aim is to distribute the Vulcan result in space and time. Two components take the majority of effort: buildings and onroad emissions. In collaboration with our INFLUX colleagues, we are transporting these high resolution emissions through an atmospheric transport model for a forward comparison of the Hestia data product with atmospheric measurements, collected on aircraft and cell towers. In preparation for a formal urban-scale inversion, these forward comparisons offer insights into both improving our emissions data product and measurement strategies. A key benefit of the approach taken in this study is the tracking and archiving of fuel and process-level detail (eg. combustion process, other pollutants), allowing for a more thorough understanding and analysis of energy throughputs in the urban

  18. Carbon Balance at Landscape Level inferred fromTower CO2 Concentration Measurements (United States)

    Chen, J. M.; Chen, B.; Higuchi, K.; Chan, D.; Shashkov, A.; Lin, H.; Liu, J.


    Terrestrial carbon sinks are considerable in the global carbon budget, but the accumulation of carbon in terrestrial ecosystems is very small (~0.2% per year) relative to the total carbon stocks in forests. Currently, eddy-covariance instruments mounted on towers are the only reliable means to measure carbon balance of a land surface, albeit limited to small areas and not free of caveats. In our quest of understanding the collective performance of ecosystems under the changing climate, it is highly desirable to have the ability to acquire carbon cycle information for large areas (landscape) consisting of patches of different ecosystems. For this purpose we explored methodologies of inferring carbon cycle information from tower CO2 concentration measurements affected by large areas (100-10000 km2). An ecosystem model named Boreal Ecosystem Productivity Simulator (BEPS) is coupled with a carbon-specific Vertical Diffusion Scheme (VDS) in order to decipher temporal variations in CO2 for landscape-level photosynthesis and respiration information. The coupled BEPS-VDS is applied to a unique 9-year (1990-2000 with 1997-8 missing data) 5-minute CO2 record measured on a 40-m tower over boreal forests near Fraserdale, Ontario, Canada. Over the period, the mean diurnal amplitude of the measured CO2 at 40 m increased by 5.58 ppmv, or 28% in the growing season. The increase in nighttime ecosystem respiration, causing the increase in the daily maximum CO2 concentration, was responsible for 65% of the increase in the diurnal amplitude, i.e., 3.61 ppmv, corresponding to an increase in the mean daily air temperature by about 2.77 degC and precipitation by 5% over the same period. The rest (35%) is explained by the increase in ecosystem daytime photosynthesis, causing the decrease in the daily minimum CO2 concentration. As the nighttime stable boundary layer (SBL) (270-560 m) was much shallower than the daytime convective boundary layer (CBL) (1000-1600 m), the increase in

  19. Microzooplankton grazing and phytoplankton growth in marine mesocosms with increased CO2 levels

    Directory of Open Access Journals (Sweden)

    Y. Carotenuto


    Full Text Available Microzooplankton grazing and algae growth responses to increasing pCO2 levels (350, 700 and 1050 μatm were investigated in nitrate and phosphate fertilized mesocosms during the PeECE III experiment 2005. Grazing and growth rates were estimated by the dilution technique combined with taxon specific HPLC pigment analysis. Microzooplankton composition was determined by light microscopy. Despite a range of up to 3 times the present CO2 levels, there were no clear differences in any measured parameter between the different CO2 treatments. During days 3–9 of the experiment the algae community standing stock, measured as chlorophyll a (Chl-a, showed the highest instantaneous grow rates (k=0.37–0.99 d−1 and increased from ca. 2–3 to 6–12 μg l−1, in all mesocosms. Afterwards the phytoplankton standing stock decreased in all mesocosms until the end of the experiment. The microzooplankton standing stock, that was mainly constituted by dinoflagellates and ciliates, varied between 23 and 130 μg C l−1 (corresponding to 1.9 and 10.8 μmol C l−1, peaking on day 13–15, apparently responding to the phytoplankton development. Instantaneous Chl-a growth rates were generally higher than the grazing rates, indicating only a limited overall effect of microzooplankton grazing on the most dominant phytoplankton. Diatoms and prymnesiophytes were significantly grazed (12–43% of the standing stock d−1 only in the pre-bloom phase when they were in low numbers, and in the post-bloom phase when they were already affected by low nutrients and/or viral lysis. The cyanobacteria populations appeared more affected by microzooplankton grazing which generally removed 20–65% of the standing stock per day.

  20. Species and gamete-specific fertilization success of two sea urchins under near future levels of pCO2 (United States)

    Sung, Chan-Gyung; Kim, Tae Won; Park, Young-Gyu; Kang, Seong-Gil; Inaba, Kazuo; Shiba, Kogiku; Choi, Tae Seob; Moon, Seong-Dae; Litvin, Steve; Lee, Kyu-Tae; Lee, Jung-Suk


    Since the Industrial Revolution, rising atmospheric CO2 concentration has driven an increase in the partial pressure of CO2 in seawater (pCO2), thus lowering ocean pH. We examined the separate effects of exposure of gametes to elevated pCO2 and low pH on fertilization success of the sea urchin Strongylocentrotus nudus. Sperm and eggs were independently exposed to seawater with pCO2 levels ranging from 380 (pH 7.96-8.3) to 6000 ppmv (pH 7.15-7.20). When sperm were exposed, fertilization rate decreased drastically with increased pCO2, even at a concentration of 450 ppmv (pH range: 7.94 to 7.96). Conversely, fertilization of Hemicentrotus pulcherrimus was not significantly changed even when sperm was exposed to pCO2 concentrations as high as 750 ppmv. Exposure of S. nudus eggs to seawater with high pCO2 did not affect fertilization success, suggesting that the effect of increased pCO2 on sperm is responsible for reduced fertilization success. Surprisingly, this result was not related to sperm motility, which was insensitive to pCO2. When seawater was acidified using HCl, leaving pCO2 constant, fertilization success in S. nudus remained high (> 80%) until pH decreased to 7.3. While further studies are required to elucidate the physiological mechanism by which elevated pCO2 impairs sperm and reduces S. nudus fertilization, this study suggests that in the foreseeable future, sea urchin survival may be threatened due to lower fertilization success driven by elevated pCO2 rather than by decreased pH in seawater.

  1. Application of conifer needles in the reconstruction of Holocene CO2 levels

    NARCIS (Netherlands)

    Kouwenberg, L.L.R.


    To clarify the nature of the link between CO2 and climate on relatively short time-scales, precise, high-resolution reconstructions of the pre-industrial evolution of atmospheric CO2 are required. Adjustment of stomatal frequency to changes in atmospheric CO2 allows plants of many species to retain

  2. Pursuing air pollutant co-benefits of CO2 mitigation in China: A provincial leveled analysis

    International Nuclear Information System (INIS)

    Dong, Huijuan; Dai, Hancheng; Dong, Liang; Fujita, Tsuyoshi; Geng, Yong; Klimont, Zbigniew; Inoue, Tsuyoshi; Bunya, Shintaro; Fujii, Minoru; Masui, Toshihiko


    Highlights: • China’s future CO 2 reduction and its co-benefits on air pollutants were projected. • GAINS-China and AIM/CGE models were combined for emission and cost estimation. • High GDP regions tended to have higher emission, reduction potential and co-benefit. • Coal ratio and coal quality were also key factors to affect reduction and co-benefit. • Mitigation investment to less developed western regions was more effective. - Abstract: With fast economic development, industrialization and urbanization, China faces increasing pressures on carbon emission reduction, and especially on air pollutants (SO 2 , NOx, PM) reduction, particularly the notorious haze issue caused by air pollution in recent years. Pursuing co-benefits is an effective approach to simultaneously respond to both carbon and air pollutant problems. In this paper, the AIM/CGE (Asia–Pacific Integrated Assessment Model/Computational General Equilibrium) model and GAINS (Greenhouse Gas and Air Pollution Interactions and Synergies)-China model are combined together to project future CO 2 and air pollutants emissions in China, as well as reduction costs and co-benefit effects. Considering implementation of carbon mitigation policy and air pollutant mitigation technologies, four scenarios (S1, S2, S3 and S4) are analyzed. Results indicate that by implementing both carbon and air pollutant mitigation (S4), CO 2 emission per GDP can be reduced by 41% by 2020, compared with the 2005 level, and SO 2 , NOx and PM2.5 emissions would change by a factor 0.8, 1.26 and 1.0 of the 2005 level, respectively in 2030. The real co-benefits of emission reductions (S2 minus S4) for SO 2 , NOx and PM2.5 are 2.4 Mt, 2.1 Mt and 0.3 Mt in 2020, and the corresponding cost reduction co-benefits are 4, 0.11, and 0.8 billion €, respectively. Provincial disparity analysis reveals that regions with higher co-benefits are those with higher GDP such as Guangdong, Shandong and Jiangsu, energy production bases such as

  3. The SMAP Level 4 Carbon PRODUCT for Monitoring Terrestrial Ecosystem-Atmosphere CO2 Exchange (United States)

    Jones, L. A.; Kimball, J. S.; Madani, N.; Reichle, R. H.; Glassy, J.; Ardizzone, J/


    The NASA Soil Moisture Active Passive (SMAP) mission Level 4 Carbon (L4_C) product provides model estimates of Net Ecosystem CO2 exchange (NEE) incorporating SMAP soil moisture information as a primary driver. The L4_C product provides NEE, computed as total respiration less gross photosynthesis, at a daily time step and approximate 14-day latency posted to a 9-km global grid summarized by plant functional type. The L4_C product includes component carbon fluxes, surface soil organic carbon stocks, underlying environmental constraints, and detailed uncertainty metrics. The L4_C model is driven by the SMAP Level 4 Soil Moisture (L4_SM) data assimilation product, with additional inputs from the Goddard Earth Observing System, Version 5 (GEOS-5) weather analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. The L4_C data record extends from March 2015 to present with ongoing production. Initial comparisons against global CO2 eddy flux tower measurements, satellite Solar Induced Canopy Florescence (SIF) and other independent observation benchmarks show favorable L4_C performance and accuracy, capturing the dynamic biosphere response to recent weather anomalies and demonstrating the value of SMAP observations for monitoring of global terrestrial water and carbon cycle linkages.

  4. Expired CO2 levels indicate degree of lung aeration at birth.

    Directory of Open Access Journals (Sweden)

    Stuart B Hooper

    Full Text Available As neonatal resuscitation critically depends upon lung aeration at birth, knowledge of the progression of this process is required to guide ongoing care. We investigated whether expired CO2 (ECO2 levels indicate the degree of lung aeration immediately after birth in two animal models and in preterm infants. Lambs were delivered by caesarean section and ventilated from birth. In lambs, ECO2 levels were significantly (p10 mmHg 28 (median (21-36 seconds before the heart rate increased above 100 beats per minute. These data demonstrate that ECO2 levels can indicate the relative degree of lung aeration after birth and can be used to clinically assess ventilation in the immediate newborn period.

  5. Triple oxygen isotope evidence for elevated CO2 levels after a Neoproterozoic glaciation. (United States)

    Bao, Huiming; Lyons, J R; Zhou, Chuanming


    Understanding the composition of the atmosphere over geological time is critical to understanding the history of the Earth system, as the atmosphere is closely linked to the lithosphere, hydrosphere and biosphere. Although much of the history of the lithosphere and hydrosphere is contained in rock and mineral records, corresponding information about the atmosphere is scarce and elusive owing to the lack of direct records. Geologists have used sedimentary minerals, fossils and geochemical models to place constraints on the concentrations of carbon dioxide, oxygen or methane in the past. Here we show that the triple oxygen isotope composition of sulphate from ancient evaporites and barites shows variable negative oxygen-17 isotope anomalies over the past 750 million years. We propose that these anomalies track those of atmospheric oxygen and in turn reflect the partial pressure of carbon dioxide (P(CO2)) in the past through a photochemical reaction network linking stratospheric ozone to carbon dioxide and to oxygen. Our results suggest that P(CO2) was much higher in the early Cambrian than in younger eras, agreeing with previous modelling results. We also find that the (17)O isotope anomalies of barites from Marinoan (approximately 635 million years ago) cap carbonates display a distinct negative spike (around -0.70 per thousand), suggesting that by the time barite was precipitating in the immediate aftermath of a Neoproterozoic global glaciation, the P(CO2) was at its highest level in the past 750 million years. Our finding is consistent with the 'snowball Earth' hypothesis and/or a massive methane release after the Marinoan glaciation.

  6. Carbon isotopic evidence for the associations of decreasing atmospheric CO2 level with the Frasnian-Famennian mass extinction (United States)

    Xu, Bing; Gu, Zhaoyan; Wang, Chengyuan; Hao, Qingzhen; Han, Jingtai; Liu, Qiang; Wang, Luo; Lu, Yanwu


    A perturbation of the global carbon cycle has often been used for interpreting the Frasnian-Famennian (F-F) mass extinction. However, the changes of atmospheric CO2 level (pCO2) during this interval are much debatable. To illustrate the carbon cycle during F-F transition, paired inorganic (δ13Ccarb) and organic (δ13Corg) carbon isotope analyses were carried out on two late Devonian carbonate sequences (Dongcun and Yangdi) from south China. The larger amplitude shift of δ13Corg compared to δ13Ccarb and its resultant Δ13C (Δ13C = δ13Ccarb - δ13Corg) decrease indicate decreased atmospheric CO2level around the F-F boundary. The onset ofpCO2 level decrease predates that of marine regressions, which coincide with the beginning of conodont extinctions, suggesting that temperature decrease induced by decreased greenhouse effect of atmospheric CO2might have contributed to the F-F mass extinction.

  7. Projected near-future CO2 levels increase activity and alter defensive behaviours in the tropical squid Idiosepius pygmaeus

    Directory of Open Access Journals (Sweden)

    Blake L. Spady


    Full Text Available Carbon dioxide (CO2 levels projected to occur in the oceans by the end of this century cause a range of behavioural effects in fish, but whether other highly active marine organisms, such as cephalopods, are similarly affected is unknown. We tested the effects of projected future CO2 levels (626 and 956 µatm on the behaviour of male two-toned pygmy squid, Idiosepius pygmaeus. Exposure to elevated CO2 increased the number of active individuals by 19–25% and increased movement (number of line-crosses by nearly 3 times compared to squid at present-day CO2. Squid vigilance and defensive behaviours were also altered by elevated CO2 with >80% of individuals choosing jet escape responses over defensive arm postures in response to a visual startle stimulus, compared with 50% choosing jet escape responses at control CO2. In addition, more escape responses were chosen over threat behaviours in body pattern displays at elevated CO2 and individuals were more than twice as likely to use ink as a defence strategy at 956 µatm CO2, compared with controls. Increased activity could lead to adverse effects on energy budgets as well as increasing visibility to predators. A tendency to respond to a stimulus with escape behaviours could increase survival, but may also be energetically costly and could potentially lead to more chases by predators compared with individuals that use defensive postures. These results demonstrate that projected future ocean acidification affects the behaviours of a tropical squid species.

  8. AIRS/Aqua Level 3 Monthly CO2 in the free troposphere (AIRS-only) V005 (United States)

    National Aeronautics and Space Administration — This is the AIRS mid-tropospheric Carbon Dioxide (CO2) Level 3 Monthly Gridded Retrieval, from the AIRS instrument on board of Aqua satellite. It is a monthly...

  9. AFSC/RACE/FBEP/Hurst: Effects of elevated CO2 levels on eggs and larvae of a North Pacific flatfish (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is from a laboratory study that examined the growth responses of northern rock sole eggs and larvae across a range of CO2 levels to evaluate the...

  10. Relationship between urbanization and CO2 emissions depends on income level and policy. (United States)

    Ponce de Leon Barido, Diego; Marshall, Julian D


    We investigate empirically how national-level CO2 emissions are affected by urbanization and environmental policy. We use statistical modeling to explore panel data on annual CO2 emissions from 80 countries for the period 1983-2005. Random- and fixed-effects models indicate that, on the global average, the urbanization-emission elasticity value is 0.95 (i.e., a 1% increase in urbanization correlates with a 0.95% increase in emissions). Several regions display a statistically significant, positive elasticity for fixed- and random-effects models: lower-income Europe, India and the Sub-Continent, Latin America, and Africa. Using two proxies for environmental policy/outcomes (ratification status for the Kyoto Protocol; the Yale Environmental Performance Index), we find that in countries with stronger environmental policy/outcomes, urbanization has a more beneficial (or, a less negative) impact on emissions. Specifically, elasticity values are -1.1 (0.21) for higher-income (lower-income) countries with strong environmental policy, versus 0.65 (1.3) for higher-income (lower-income) countries with weak environmental policies. Our finding that the urbanization-emissions elasticity may depend on the strength of a country's environmental policy, not just marginal increases in income, is in contrast to the idea of universal urban scaling laws that can ignore local context. Most global population growth in the coming decades is expected to occur in urban areas of lower-income countries, which underscores the importance of these findings.

  11. Potassium starvation limits soybean growth more than the photosynthetic processes across CO2 levels (United States)

    Potassium (K) deficiency might alter plant response to rising atmospheric carbon dioxide (CO2) and influence growth, and photosynthetic processes differently. To evaluate the combined effects of K and CO2 on soybean photosynthesis, growth, biomass partitioning, and yields, plants were grown under co...

  12. Late Cretaceous climate simulations with different CO2 levels and subarctic gateway configurations: A model-data comparison (United States)

    Niezgodzki, Igor; Knorr, Gregor; Lohmann, Gerrit; Tyszka, Jarosław; Markwick, Paul J.


    We investigate the impact of different CO2 levels and different subarctic gateway configurations on the surface temperatures during the latest Cretaceous using the Earth System Model COSMOS. The simulated temperatures are compared with the surface temperature reconstructions based on a recent compilation of the latest Cretaceous proxies. In our numerical experiments, the CO2 level ranges from 1 to 6 times the preindustrial (PI) CO2 level of 280 ppm. On a global scale, the most reasonable match between modeling and proxy data is obtained for the experiments with 3 to 5 × PI CO2 concentrations. However, the simulated low- (high-) latitude temperatures are too high (low) as compared to the proxy data. The moderate CO2 levels scenarios might be more realistic, if we take into account proxy data and the dead zone effect criterion. Furthermore, we test if the model-data discrepancies can be caused by too simplistic proxy-data interpretations. This is distinctly seen at high latitudes, where most proxies are biased toward summer temperatures. Additional sensitivity experiments with different ocean gateway configurations and constant CO2 level indicate only minor surface temperatures changes (greenhouse worlds is best constrained by temperatures in the midlatitudes.

  13. Simulated response of conterminous United States ecosystems to climate change at different levels of fire suppression, CO2 emission rate, and growth response to CO2 (United States)

    James M. Lenihan; Dominique Bachelet; Ronald P. Neilson; Raymond Drapek


    A modeling experiment was designed to investigate the impact of fire management, CO2 emission rate, and the growth response to CO2 on the response of ecosystems in the conterminous United States to climate scenarios produced by three different general circulation models (GCMs) as simulated by the MCl Dynamic General...

  14. Secondary scintillation yield of xenon with sub-percent levels of CO2 additive for rare-event detection (United States)

    Henriques, C. A. O.; Freitas, E. D. C.; Azevedo, C. D. R.; González-Díaz, D.; Mano, R. D. P.; Jorge, M. R.; Fernandes, L. M. P.; Monteiro, C. M. B.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carríon, J. V.; Cebrían, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Ferrario, P.; Ferreira, A. L.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monrabal, F.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D. R.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.; NEXT Collaboration


    Xe-CO2 mixtures are important alternatives to pure xenon in Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification with applications in the important field of rare event detection such as directional dark matter, double electron capture and double beta decay detection. The addition of CO2 to pure xenon at the level of 0.05-0.1% can reduce significantly the scale of electron diffusion from 10 mm /√{m} to 2.5 mm /√{m}, with high impact on the discrimination efficiency of the events through pattern recognition of the topology of primary ionization trails. We have measured the electroluminescence (EL) yield of Xe-CO2 mixtures, with sub-percent CO2 concentrations. We demonstrate that the EL production is still high in these mixtures, 70% and 35% relative to that produced in pure xenon, for CO2 concentrations around 0.05% and 0.1%, respectively. The contribution of the statistical fluctuations in EL production to the energy resolution increases with increasing CO2 concentration, being smaller than the contribution of the Fano factor for concentrations below 0.1% CO2.

  15. Secondary scintillation yield of xenon with sub-percent levels of CO2 additive for rare-event detection

    Directory of Open Access Journals (Sweden)

    C.A.O. Henriques


    Full Text Available Xe–CO2 mixtures are important alternatives to pure xenon in Time Projection Chambers (TPC based on secondary scintillation (electroluminescence signal amplification with applications in the important field of rare event detection such as directional dark matter, double electron capture and double beta decay detection. The addition of CO2 to pure xenon at the level of 0.05–0.1% can reduce significantly the scale of electron diffusion from 10 mm/m to 2.5 mm/m, with high impact on the discrimination efficiency of the events through pattern recognition of the topology of primary ionization trails. We have measured the electroluminescence (EL yield of Xe–CO2 mixtures, with sub-percent CO2 concentrations. We demonstrate that the EL production is still high in these mixtures, 70% and 35% relative to that produced in pure xenon, for CO2 concentrations around 0.05% and 0.1%, respectively. The contribution of the statistical fluctuations in EL production to the energy resolution increases with increasing CO2 concentration, being smaller than the contribution of the Fano factor for concentrations below 0.1% CO2.

  16. Signals of ENSO related precipitation changes and atmospheric CO2 levels in Florida wetland vegetation (United States)

    Wagner, F.


    Trees are equipped with a plastic phenotype, capable of sustained adjustment of leaf stomata to changes in atmospheric [CO2] concentration. With high temporal resolution and accuracy, stomatal frequency data demonstrate that Holocene climate evolution has been influenced by century-scale [CO2] fluctuations. Apart from adapting to changes in [CO2], leaf-epidermal properties are known to be sensitive to environmental factors such as water availability. In long-lived hygrophilous plants, epidermal tissue expansion is likely to be significantly influenced by changes in water availability. Synchronous analysis of the leaf-morphology in [CO2] sensitive trees and water-stress sensitive fern species from leaf assemblages preserved in peat deposits in Florida (USA), reveals distinct temporal changes in epidermal properties over the past 100 years. Stomatal frequency changes in the deciduous trees reflects the human induced [CO2] increase. Epidermal-cell density changes in fern leaves, could well be interpreted in terms of El Niño / La Niña related precipitation trends. By quantifying the leaf morphological adaptation to known environmental conditions during historical times, a new palaeobotanical proxy for past precipitation changes is introduced. Hence, in El Niño sensitive regions, analysis of buried leaf assemblages offers the unique possibility of a direct recognition of time-equivalent leaf-based signals of palaeo-atmospheric [CO2] and El Niño variability.

  17. Impact of global warming and rising CO2 levels on coral reef fishes: what hope for the future? (United States)

    Munday, Philip L; McCormick, Mark I; Nilsson, Göran E


    Average sea-surface temperature and the amount of CO(2) dissolved in the ocean are rising as a result of increasing concentrations of atmospheric CO(2). Many coral reef fishes appear to be living close to their thermal optimum, and for some of them, even relatively moderate increases in temperature (2-4°C) lead to significant reductions in aerobic scope. Reduced aerobic capacity could affect population sustainability because less energy can be devoted to feeding and reproduction. Coral reef fishes seem to have limited capacity to acclimate to elevated temperature as adults, but recent research shows that developmental and transgenerational plasticity occur, which might enable some species to adjust to rising ocean temperatures. Predicted increases in P(CO(2)), and associated ocean acidification, can also influence the aerobic scope of coral reef fishes, although there is considerable interspecific variation, with some species exhibiting a decline and others an increase in aerobic scope at near-future CO(2) levels. As with thermal effects, there are transgenerational changes in response to elevated CO(2) that could mitigate impacts of high CO(2) on the growth and survival of reef fishes. An unexpected discovery is that elevated CO(2) has a dramatic effect on a wide range of behaviours and sensory responses of reef fishes, with consequences for the timing of settlement, habitat selection, predator avoidance and individual fitness. The underlying physiological mechanism appears to be the interference of acid-base regulatory processes with brain neurotransmitter function. Differences in the sensitivity of species and populations to global warming and rising CO(2) have been identified that will lead to changes in fish community structure as the oceans warm and becomes more acidic; however, the prospect for acclimation and adaptation of populations to these threats also needs to be considered. Ultimately, it will be the capacity for species to adjust to environmental

  18. Laser plant "Iguana" for transmyocardial revascularization based on kW-level waveguide CO2 laser (United States)

    Panchenko, Vladislav Y.; Bockeria, L. A.; Berishvili, I. I.; Vasiltsov, Victor V.; Golubev, Vladimir S.; Ul'yanov, Valery A.


    For many years the Institute on Laser and Information Technologies RAN has been developing a concept of high-power industrial CO2 lasers with diffusion cooling of the working medium. The paper gives a description of the laser medical system Iguana for transmyocardial laser revascularization (TMLR) as an example of various applications of high-power waveguide CO2 lasers. The clinical results of the TMLR method application in surgical treatment are presented. The methods of determination of the time, when the laser beam passes through the demarcation line between myocardium tissue and blood, are discussed.

  19. The importance of geomagnetic field changes versus rising CO2 levels for long-term change in the upper atmosphere

    Directory of Open Access Journals (Sweden)

    Cnossen Ingrid


    Full Text Available The Earth’s upper atmosphere has shown signs of cooling and contraction over the past decades. This is generally attributed to the increasing level of atmospheric CO2, a coolant in the upper atmosphere. However, especially the charged part of the upper atmosphere, the ionosphere, also responds to the Earth’s magnetic field, which has been weakening considerably over the past century, as well as changing in structure. The relative importance of the changing geomagnetic field compared to enhanced CO2 levels for long-term change in the upper atmosphere is still a matter of debate. Here we present a quantitative comparison of the effects of the increase in CO2 concentration and changes in the magnetic field from 1908 to 2008, based on simulations with the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM. This demonstrates that magnetic field changes contribute at least as much as the increase in CO2 concentration to changes in the height of the maximum electron density in the ionosphere, and much more to changes in the maximum electron density itself and to low-/mid-latitude ionospheric currents. Changes in the magnetic field even contribute to cooling of the thermosphere at ~300 km altitude, although the increase in CO2 concentration is still the dominant factor here. Both processes are roughly equally important for long-term changes in ion temperature.

  20. Estimation of CO2 baseline level using a statistical approach for near-road vehicle emission measurements (United States)

    Wong, Ka Chun; Ning, Zhi; Chan, Ka Lok


    Vehicle emission is widely accepted as one of the major air pollution problems in metropolitan. Many different experimental setups have been designed to measure the direct emission from vehicles in order to study their impact to local air quality. Near-road/roadside in-situ measurement is one of the most common methods for vehicle emission measurement, providing emission data of vehicle under real driving conditions. In addition, the measurement system can be fully automatized and provides a better way to collect vehicular emission data. Previous studies show that 5% of the total vehicles contribute 50% of the total vehicle emission. In this study, we use the roadside measurement data for the fuel-based emission factor calculation in order to identify heavy emitters. The emission factor calculation uses CO2 as an indicator for the fuel consumption rate. However, this measurement technique suffers from high detection limit and large uncertainty of the CO2 measurement. As a result, heavy emitters with low fuel consumption rate cannot be easily detected. A new data analysis algorithm is developed to estimate the CO2 baseline for near-road/roadside vehicle emission measurements. We investigated the error distribution of the CO2 measurement and use a statistical approach to identify the baseline levels. Our study provides an alternative solution for the CO2 concentration baseline calculation.

  1. Marine CDOM accumulation during a coastal Arctic mesocosm experiment: No response to elevated pCO2 levels

    NARCIS (Netherlands)

    Pavlov, A.K.; Silyakova, A.; Granskog, M.A.; Bellerby, R.G.J.; Engel, A.; Schulz, K.G.; Brussaard, C.P.D.


    A large-scale multidisciplinary mesocosm experiment in an Arctic fjord (Kongsfjorden, Svalbard; 78°56.2′N) was used to study Arctic marine food webs and biogeochemical elements cycling at natural and elevated future carbon dioxide (CO2) levels. At the start of the experiment, marine-derived

  2. Modeling CO2 emissions from Arctic lakes: Model development and site-level study (United States)

    Tan, Zeli; Zhuang, Qianlai; Shurpali, Narasinha J.; Marushchak, Maija E.; Biasi, Christina; Eugster, Werner; Walter Anthony, Katey


    Recent studies indicated that Arctic lakes play an important role in receiving, processing, and storing organic carbon exported from terrestrial ecosystems. To quantify the contribution of Arctic lakes to the global carbon cycle, we developed a one-dimensional process-based Arctic Lake Biogeochemistry Model (ALBM) that explicitly simulates the dynamics of organic and inorganic carbon in Arctic lakes. By realistically modeling water mixing, carbon biogeochemistry, and permafrost carbon loading, the model can reproduce the seasonal variability of CO2 fluxes from the study Arctic lakes. The simulated area-weighted CO2 fluxes from yedoma thermokarst lakes, nonyedoma thermokarst lakes, and glacial lakes are 29.5, 13.0, and 21.4 g C m-2 yr-1, respectively, close to the observed values (31.2, 17.2, and 16.5 ± 7.7 g C m-2 yr-1, respectively). The simulations show that the high CO2 fluxes from yedoma thermokarst lakes are stimulated by the biomineralization of mobilized labile organic carbon from thawing yedoma permafrost. The simulations also imply that the relative contribution of glacial lakes to the global carbon cycle could be the largest because of their much larger surface area and high biomineralization and carbon loading. According to the model, sunlight-induced organic carbon degradation is more important for shallow nonyedoma thermokarst lakes but its overall contribution to the global carbon cycle could be limited. Overall, the ALBM can simulate the whole-lake carbon balance of Arctic lakes, a difficult task for field and laboratory experiments and other biogeochemistry models.

  3. Nitrous Oxide Emissions in a Managed Grassland are Strongly Influenced by CO2 Concentrations Across a Range of Soil Moisture Levels (United States)

    Brown, Z. A.; Hovenden, M. J.; Hunt, M.


    Though the atmosphere contains less nitrous oxide (N2O, 324 ppb) than carbon dioxide (CO2, 400 ppm­), N2O has 298 times the global warming potential of CO2 on a 100-year horizon. Nitrous oxide emissions tend to be greater in moist soils because denitrification is an anaerobic process. The rising concentration of CO2 in the atmosphere reduces plant stomatal aperture, thereby slowing transpiration and water use and leading to higher soil moisture levels. Thus, the rising CO2 concentration could stimulate N2O emissions indirectly via increasing soil moisture. Further, results from field experiments in which CO2 is elevated have demonstrated nitrification is accelerated at elevated CO2 concentrations (eCO2). Hence, N2O emissions could be substantially increased by the impacts of rising CO2 concentrations on plant and ecosystem physiology. However, the scale of this impact could be influenced by the amount of water supplied through irrigation or rainfall since both nitrification and denitrification are sensitive to soil moisture. Here, we use measurements of CO2 and N2O emissions from the TasFACE2 experiment to explore the ways in which the impact of CO2 concentration on greenhouse gas emissions is influenced by water supply in a managed temperate pasture. TasFACE2 is the world's only experiment that explicitly controls soil water availability at three different CO2 concentrations. Application of chemical nitrification inhibitor severely reduces N2O flux from soils regardless of CO2 level, water treatment and time following urea application. This inhibitor reduced soil respiration in plots exposed to ambient CO2 plots but not in eCO2 plots. N2O flux is stimulated by eCO2 but not consistently among watering treatments or seasons. Soil respiration is strongly enhanced by CO2 effect regardless of watering treatment. The results demonstrate that CO2 concentration has a sustained impact on CO2 and N2O flux across a range of water availabilities in this fertilised, ryegrass

  4. Fluctuating seawater pH/pCO2regimes are more energetically expensive than static pH/pCO2levels in the musselMytilus edulis. (United States)

    Mangan, Stephanie; Urbina, Mauricio A; Findlay, Helen S; Wilson, Rod W; Lewis, Ceri


    Ocean acidification (OA) studies typically use stable open-ocean pH or CO 2 values. However, species living within dynamic coastal environments can naturally experience wide fluctuations in abiotic factors, suggesting their responses to stable pH conditions may not be reflective of either present or near-future conditions. Here we investigate the physiological responses of the mussel Mytilus edulis to variable seawater pH conditions over short- (6 h) and medium-term (2 weeks) exposures under both current and near-future OA scenarios. Mussel haemolymph pH closely mirrored that of seawater pH over short-term changes of 1 pH unit with acidosis or recovery accordingly, highlighting a limited capacity for acid-base regulation. After 2 weeks, mussels under variable pH conditions had significantly higher metabolic rates, antioxidant enzyme activities and lipid peroxidation than those exposed to static pH under both current and near-future OA scenarios. Static near-future pH conditions induced significant acid-base disturbances and lipid peroxidation compared with the static present-day conditions but did not affect the metabolic rate. These results clearly demonstrate that living in naturally variable environments is energetically more expensive than living in static seawater conditions, which has consequences for how we extrapolate future OA responses in coastal species. © 2017 The Authors.

  5. Quantification of fossil fuel CO2 at the building/street level for the LA Megacity (United States)

    Gurney, K. R.; Razlivanov, I. N.; Patarasuk, R.; Song, Y.; O'Keeffe, D.; Duren, R. M.; Eldering, A.


    Quantification of fossil fuel CO2 emissions from the bottom-up perspective is a critical element in emerging plans on a global, integrated, carbon monitoring system (CMS). A space/time explicit emissions data product can act as both verification and guidance to emissions mitigation. We have progress on applying our Hestia approach to the entire LA Basin. Here, we present these initial results focusing on a few points of progress worthy of dissemination. Geocoding of the original point sources are inaccurate, placing point sources in the wrong physical position. Sometimes these errors are many kilometers. We have corrected the majority of these point through a variety of techniques. The LAX airport and the LA Port pose large unique sources in the Basin and we have taken novel approaches to characterizing the space/time distribution of these emission sources. We have used AADT and hourly traffic data to best distribute emissions in the onroad sector. This has required both extrapolation and interpolation techniques to fully cover all road types other than local roads. Finally, we have updated the emission product to the year 2012 using a variety of scaling arguments. Work on greenhouse gas emissions has been accomplished by others, though these efforts typically go down to only the county spatial scale. However, these offer numerous opportunities to potentially calibrate or explore alternative methods and results. We will review these efforts and what benefit they are provided thus far. Finally, we will review our attempts to quantify uncertainty at the space/time scales attempted here. Uncertainty quantification remains challenging due to a variety of reasons. First, bottom-up source data is often produced by a regulatory agency, which has strict legal limits to the amount and type of information available. Even in cases where legal limitations are not at work, there is no standard for uncertainty reporting and hence, little reliable uncertainty estimation is made

  6. Greenhouse Gas (CH4, CO2 and N2O) Emission Levels by Wastewater Treatment Plant (WWTP) Ponds in Brazil (United States)

    Rossete, A. L. M.; Sundefeld Junior, G.; Aparicio, C.; Baldi, G. G.; Montes, C. R.; Piveli, R. P.; Melfi, A. J.


    This study measured greenhouse gas emissions (GHG) by Facultative Ponds on Wastewater Treatment Plants. The most studied GHGs include CO2, CH4and N2O. The level of GHG (CO2, CH4 and N2O) emissions by WWTPs in Australian-type stabilization ponds was measured in the city of Lins (22º21'S, 49º50'W), state of São Paulo (SP), Brazil. GHG collection was carried outusing a collection chamber installed at the center of the facultative pond's final third. The effluent's pH and temperature (ET) were registered by probes, and meteorological information regarding air temperature (AT) and solar radiation (SR) were obtained from INMET, Brazil. GHG collection was carried out for 72 consecutive hours in June 2014, on an hourly basis, once every 5 minutes, for the first 30 minutes, and once every 10 minutes from 30 to 50 minutesand subsequently analyzed by gas chromatograph (GC).After three days of data collection, the average AT, SR, ET and pH values were, respectively, 18oC, 2583kJm-2, 23oC and 8.2. Average values for GHG emission levels (CH4, CO2 and N2O) were 79.01; 100.65 and 0.0 mg m-2 h-1, respectively. GHG emission levels were divided into light periods (morning, afternoon and evening)in order to verify the periods with the highest GHG emissions.The highest CH4 emission levels were measured between morning and early afternoon. The maximum CO2 emissions were observed from evening to early morning. N2O emissions were constant and values were close to the ones found in the atmosphere, which shows the emission of N2O by facultative ponds does not contribute to greenhouse gases emissions.The results enabled us to characterize and quantify GHG emission levels per Facultative Pond on Wastewater Treatment Plant. Acknowledgment to FAPESP and SABESP, Brazil.

  7. Effect of Nocturnal Low-level Jet on Nighttime CO2 Concentrations and Fluxes: a Numerical Sensitive Study (United States)

    Sogachev, A.; Jørgensen, H.; Leclerc, M. Y.; Duarte, H. F.; Durden, D.; Pingintha, N.; Zhang, G.


    It has been shown recently that net ecosystem exchange is impacted by nocturnal low-level jets (LLJs). The presence of a LLJ impedes vertical gaseous dispersion and facilitates gas accumulation, often to the level of the wind maximum, which can be well below the temperature inversion level (Mathieu et al., 2005; Karipot et al., 2006; 2007; 2008; 2009). The present study uses the numerical atmospheric boundary-layer (ABL) model SCADIS described by Sogachev et al. (2002) in its one-dimensional mode to examine specific effects of the structure of nocturnal jets on nighttime CO2 concentrations and fluxes. From a variety of mechanisms suggested for formation of LLJs, such as inertial oscillations, baroclinicity over sloping terrain, and land-sea breeze effects (Stull, 1988), the one-dimensional ABL model is capable of simulating only the first one. The unique feature of the SCADIS model, based on a two-equation closure approach, is the treatment of buoyancy and plant drag effects in a way that does not require a predefined mixing length (Sogachev, 2009). Although pure inertial oscillations attributed only to the diurnal oscillation of eddy viscosity are rare and are typically intertwined with other contributing factors, they constitute an important cause of jet formation. Sensitive tests were carried out with SCADIS to examine the response of nighttime CO2 concentrations and fluxes to low-level jet structural changes caused by different forcing at the air-forest interface. Results show that the model captures the most prominent features of both the LLJ, including its vertical structure as well as its diurnal phase and amplitude, and the conceptual model for nocturnal accumulation of gases beneath a LLJ suggested by Mathieu et al. (2005). Primarily, that gas accumulation is stronger beneath LLJs that are decoupled from the surface than those that are coupled since the latter allow turbulent mixing down to the surface. Both the structure of the LLJ and CO2 concentration

  8. Effects of elevated CO2 on the photosynthesis and nitrate reductase activity of Pyropia haitanensis (Bangiales, Rhodophyta) grown at different nutrient levels (United States)

    Liu, Chunxiang; Zou, Dinghui


    Pyropia haitanensis, a commercially important species, was cultured at two CO2 concentrations (390×10-6 and 700×10-6 (parts per million)) and at low and high nutrient levels, to explore the effect of elevated CO2 on the species under nutrient enrichment. Results show that in CO2-enriched thalli, relative growth rate (RGR) was enhanced under nutrient enrichment. Elevated CO2 decreased phycobiliprotein (PB) contents, but increased the contents of soluble carbohydrates. Nutrient enrichment increased the contents of chlorophyll a (Chl a) and PB, while soluble carbohydrate content decreased. CO2 enrichment enhanced the relative maximum electronic transport rate and light saturation point. In nutrient-enriched thalli the activity of nitrate reductase (NRA) increased under elevated CO2. An instantaneous pH change in seawater (from 8.1 to 9.6) resulted in reduction of NRA, and the thalli grown under both elevated CO2 and nutrient enrichment exhibited less pronounced reduction than in algae grown at the ambient CO2. The thermal optima of NRA under elevated CO2 and/or nutrient enrichment shifted to a lower temperature (10-15°C) compared to that in ambient conditions (20°C). We propose that accelerated photosynthesis could result in growth increment. N assimilation remained high in acidified seawater and reflected increased temperature sensitivity in response to elevated CO2 and eutrophication.

  9. Marine CDOM accumulation during a coastal Arctic mesocosm experiment: No response to elevated pCO2 levels (United States)

    Pavlov, Alexey K.; Silyakova, Anna; Granskog, Mats A.; Bellerby, Richard G. J.; Engel, Anja; Schulz, Kai G.; Brussaard, Corina P. D.


    A large-scale multidisciplinary mesocosm experiment in an Arctic fjord (Kongsfjorden, Svalbard; 78°56.2'N) was used to study Arctic marine food webs and biogeochemical elements cycling at natural and elevated future carbon dioxide (CO2) levels. At the start of the experiment, marine-derived chromophoric dissolved organic matter (CDOM) dominated the CDOM pool. Thus, this experiment constituted a convenient case to study production of autochthonous CDOM, which is typically masked by high levels of CDOM of terrestrial origin in the Arctic Ocean proper. CDOM accumulated during the experiment in line with an increase in bacterial abundance; however, no response was observed to increased pCO2 levels. Changes in CDOM absorption spectral slopes indicate that bacteria were most likely responsible for the observed CDOM dynamics. Distinct absorption peaks (at 330 and 360 nm) were likely associated with mycosporine-like amino acids (MAAs). Due to the experimental setup, MAAs were produced in absence of ultraviolet exposure providing evidence for MAAs to be considered as multipurpose metabolites rather than simple photoprotective compounds. We showed that a small increase in CDOM during the experiment made it a major contributor to total absorption in a range of photosynthetically active radiation (PAR, 400-700 nm) and, therefore, is important for spectral light availability and may be important for photosynthesis and phytoplankton groups composition in a rapidly changing Arctic marine ecosystem.

  10. Coupling of heterotrophic bacteria to phytoplankton bloom development at different pCO2 levels: a mesocosm study

    Directory of Open Access Journals (Sweden)

    R. Thyrhaug


    Full Text Available The predicted rise in anthropogenic CO2 emissions will increase CO2 concentrations and decrease seawater pH in the upper ocean. Recent studies have revealed effects of pCO2 induced changes in seawater chemistry on a variety of marine life forms, in particular calcifying organisms. To test whether the predicted increase in pCO2 will directly or indirectly (via changes in phytoplankton dynamics affect abundance, activities, and community composition of heterotrophic bacteria during phytoplankton bloom development, we have aerated mesocosms with CO2 to obtain triplicates with three different partial pressures of CO2 (pCO2: 350 μatm (1×CO2, 700 μatm (2×CO2 and 1050 μatm (3×CO2. The development of a phytoplankton bloom was initiated by the addition of nitrate and phosphate. In accordance to an elevated carbon to nitrogen drawdown at increasing pCO2, bacterial production (BPP of free-living and attached bacteria as well as cell-specific BPP (csBPP of attached bacteria were related to the C:N ratio of suspended matter. These relationships significantly differed among treatments. However, bacterial abundance and activities were not statistically different among treatments. Solely community structure of free-living bacteria changed with pCO2 whereas that of attached bacteria seemed to be independent of pCO2 but tightly coupled to phytoplankton bloom development. Our findings imply that changes in pCO2, although reflected by changes in community structure of free-living bacteria, do not directly affect bacterial activity. Furthermore, bacterial activity and dynamics of heterotrophic bacteria, especially of attached bacteria, were tightly correlated to phytoplankton development and, hence, may also potentially depend on changes in pCO2.

  11. In-cabin ultrafine particle dynamics (United States)

    Xu, Bin

    To assess the total human health risks associated with human exposure to ultrafine particle (UFP), the concentrations and fates of UFPs in the in-cabin atmospheres must be understood. In order to assess human exposure more accurately and further prevent adverse health effects from UFP exposure in the in-cabins, it is essential to gain insight into UFP transport dynamics between in-cabin and outside atmospheres and the factors that are able to affect them. In this dissertation, mathematical model are developed and formulated as tools to improve the understanding of UFP dynamics in the in-cabin atmosphere. Under three different ventilation conditions, (i) Fan off-recirculation (RC) off, (ii) Fan on-RC off, and (iii) Fan on-RC on, the average modeled UFP I/O ratios were found to be 0.40, 0.25 and 0.10, respectively, and agree with the experimental data very well. Then, analysis focused on how the factors, such as ventilation settings, vehicle speed, filtration, penetration, and deposition, affect I/O ratios in broader categories of vehicle cabin microenvironments. Ventilation is the only mechanical process of exchanging air between the in-cabin and the outside. Under condition (ii), I/O ratio that varies from 0.2 to 0.7 was proportional to the airflow rate in the range of 0-360 m3/h. Under condition (iii), the modeled I/O ratio was inversely proportional to the airflow rate from mechanical ventilation within the range of 0.15-0.45 depending on the particle size. Significant variability of the penetration factor (5˜20%) was found due to the pressure difference. A coefficient "B" was successfully introduced to account for the electric charge effect on penetration factors. The effect of penetration on the I/O ratio was then evaluated by substituting penetration factor into the model. Under condition (i), the modeled I/O ratios increased linearly, up to ˜20%, within the penetration factor range. Under condition (iii), the effect of penetration factor is less but still

  12. Interactions of radionuclides and CO2 with clays: elucidating mechanisms at nano-scale level

    International Nuclear Information System (INIS)

    Yang, Wei


    In order to predict and regulate the environmental impact of human activities such as uranium mining and radioactive waste disposal, it is necessary to understand the behavior of actinides in the environment because their interaction with clay mineral is an important factor to control the migration of radionuclide in the environment. The behavior of actinides in the soil is mainly the surface adsorption interactions, which change the forms of radioactive elements and reduces the mobility of actinides in the natural systems. Therefore, it is important to search how the actinides interact with clay mineral such as the fundamental process of surface precipitation. Uranium is the predominant heavy metal content of the final waste in the nuclear fuel cycle (≥95% UO 2 ). In addition, uranium is a major contaminant in the soil, subsurface and groundwater as a result of human activity. Under standard environmental conditions, the most stable chemical form of U(VI) is the uranyl ion UO 2 2+ , which is potentially very mobile and readily complexes with organic and inorganic matter. On the other hand, carbon dioxide is an important greenhouse gas, warming the earth's surface to a higher temperature by reducing outward radiation. However, problems may occur when the atmospheric concentration of greenhouse gases increases. Amounts of carbon dioxide were produced since the industrial revolution, which is behind the significant global warming and rising sea level. Clay minerals are of great practical importance here, in storage of carbon dioxide due to its hydraulic permeability and ability to retain mobile species. We have chosen kaolinite and montmorillonite as prototypes of clay minerals of 1:1 and 2:1. Classical Monte Carlo (MC) and molecular dynamics (MD) methods have been used in this work in order to understand the adsorption behaviour of radionuclide and carbon dioxide in clays surface. In this thesis, we will investigate first the adsorption of uranyl on kaolinite

  13. Injeção de CO2 e lâminas de irrigação em tomateiro sob estufa CO2 injection and irrigation levels in greenhouse tomatoes

    Directory of Open Access Journals (Sweden)

    Denis Cesar Cararo


    -se os dados a funções quadráticas, foram de 78,82 t.ha-1 e 86,36 t.ha-1, correspondentes à aplicação de 335,2 mm e 333,6 mm de água para as estufas sem e com aplicação de CO2, respectivamente. Para uma faixa de variação do produto físico marginal de 0 a 1, as lâminas economicamente ótimas variaram de 335,2 mm a 322,4 mm em ausência de CO2 e de 333,6 mm a 323,8 mm com utilização do gás.The application of appropriate amounts of water and the usage of associated techniques improve the yield and quality of tomato fruits, assuring better profits to the farmer. We studied the effect of different water depth applications and carbon dioxide (CO2 injection in the irrigation system of a tomato crop, cv. Débora-Plus. An experiment was conducted in Piracicaba, São Paulo State (Brazil, under two greenhouses, using 40; 60; 80; 100; 120 and 140% of the water depth needed by the crop and C0 = 0 g of CO2.L-1 of water and C1 = 7.73 g.L-1 of CO2 concentrations were applied through irrigation water during 1999. The experiment was conducted in completely randomized blocks, with four replications. The CO2 treatments were applied in separate greenhouses. The irrigation was accomplished by using a drip irrigation system, based on reduced evaporimeters and tensiometers. The gas application was accomplished using a commercial cylinder and a Venturi type injector during the period necessary to reach the minimum water level. The application of CO2 through irrigation water increased the yield by 8.2%, raised the weight of small size fruits by 13% and the dry matter content of fruits by 8.5%. However, CO2 injection was ineffective in increasing the number and weight of medium sized fruits. The soil solution analysis indicated that CO2 possibly contributes to the improvement of the nutritional conditions of the tomato crop. The gas injection was economically feasible. The water depth did not have any significant effect on the yield, on total number of fruits, medium fruit weight

  14. Carbon inequality at the sub-national scale: A case study of provincial-level inequality in CO2 emissions in China 1997-2007

    International Nuclear Information System (INIS)

    Clarke-Sather, Afton; Qu Jiansheng; Wang Qin; Zeng Jingjing; Li Yan


    This study asks whether sub-national inequalities in carbon dioxide (CO 2 ) emissions mirror international patterns in carbon inequality using the case study of China. Several studies have examined global-level carbon inequality; however, such approaches have not been used on a sub-national scale. This study examines inter-provincial inequality in CO 2 emissions within China using common measures of inequality (coefficient of variation, Gini Index, Theil Index) to analyze provincial-level data derived from the IPCC reference approach for the years 1997-2007. It decomposes CO 2 emissions inequality into its inter-regional and intra-regional components. Patterns of per capita CO 2 emissions inequality in China appear superficially similar to, though slightly lower than, per capita income inequality. However, decomposing these inequalities reveals different patterns. While inter-provincial income inequality is highly regional in character, inter-provincial CO 2 emissions inequality is primarily intra-regional. While apparently similar, global patterns in CO 2 emissions are not mirrored at the sub-national scale. - Highlights: → Carbon inequality is different in character within China than at global scale. → Interprovincial CO 2 emissions inequality in China is slightly lower than income inequality. → Interprovincial GDP inequality in China is regional in character. → Interprovincial CO 2 emissions inequality in China is not regional in character.

  15. The difference of level CO2 emissions from the transportation sector between weekdays and weekend days on the City Centre of Pemalang (United States)

    Sawitri, E.; Hardiman, G.; Buchori, I.


    The high growth of human activity potentially increases the number of vehicles and the use of fossil fuels that contribute the increase of CO2 emissions in atmosphere. Controlling CO2 emission that causes greenhouse effect becomes the main agenda of Indonesian Government. The first step control CO2 emissions is by measuring the level of CO2 emissions, especially CO2 emissions from fossil fuel consumption in the transport sector. This research aims to assess the level of CO2 emissions from transportation sector on the main roads in the city centre of Pemalang both in weekdays and weekend days. The methods applied to calculate CO2 emissions using Intergovernmental Panel on Climate Change (IPCC) 2006 method. For this, a survey on the number of vehicles passing through the main roads using hand tally counter is firstly done. The results, CO2 emissions in working day, i.e. 49,006.95 tons/year compared to weekend i.e. 38,865.50 tons/year.

  16. Elevated CO2 levels affect the activity of nitrate reductase and carbonic anhydrase in the calcifying rhodophyte Corallina officinalis


    Hofmann, Laurie C.; Straub, Sandra; Bischof, Kai


    The concentration of CO2 in global surface ocean waters is increasing due to rising atmospheric CO2 emissions, resulting in lower pH and a lower saturation state of carbonate ions. Such changes in seawater chemistry are expected to impact calcification in calcifying marine organisms. However, other physiological processes related to calcification might also be affected, including enzyme activity. In a mesocosm experiment, macroalgal communities were exposed to three CO2 concentrations (380, 6...

  17. Interactive effects of elevated temperature and CO(2) levels on metabolism and oxidative stress in two common marine bivalves (Crassostrea virginica and Mercenaria mercenaria). (United States)

    Matoo, Omera B; Ivanina, Anna V; Ullstad, Claus; Beniash, Elia; Sokolova, Inna M


    Marine bivalves such as the hard shell clams Mercenaria mercenaria and eastern oysters Crassostrea virginica are affected by multiple stressors, including fluctuations in temperature and CO2 levels in estuaries, and these stresses are expected to be exacerbated by ongoing global climate change. Hypercapnia (elevated CO2 levels) and temperature stress can affect survival, growth and development of marine bivalves, but the cellular mechanisms of these effects are not yet fully understood. In this study, we investigated whether oxidative stress is implicated in cellular responses to elevated temperature and CO2 levels in marine bivalves. We measured the whole-organism standard metabolic rate (SMR), total antioxidant capacity (TAOC), and levels of oxidative stress biomarkers in the muscle tissues of clams and oysters exposed to different temperatures (22 and 27°C) and CO2 levels (the present day conditions of ~400ppm CO2 and 800ppm CO2 predicted by a consensus business-as-usual IPCC emission scenario for the year 2100). SMR was significantly higher and the antioxidant capacity was lower in oysters than in clams. Aerobic metabolism was largely temperature-independent in these two species in the studied temperature range (22-27°C). However, the combined exposure to elevated temperature and hypercapnia led to elevated SMR in clams indicating elevated costs of basal maintenance. No persistent oxidative stress signal (measured by the levels of protein carbonyls, and protein conjugates with malondialdehyde and 4-hydroxynonenal) was observed during the long-term exposure to moderate warming (+5°C) and hypercapnia (~800ppm CO2). This indicates that long-term exposure to moderately elevated CO2 and temperature minimally affects the cellular redox status in these bivalve species and that the earlier observed negative physiological effects of elevated CO2 and temperature must be explained by other cellular mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Elevated CO2 levels increase the toxicity of ZnO nanoparticles to goldfish (Carassius auratus) in a water-sediment ecosystem

    International Nuclear Information System (INIS)

    Yin, Ying; Hu, Zhengxue; Du, Wenchao; Ai, Fuxun; Ji, Rong; Gardea-Torresdey, Jorge L.; Guo, Hongyan


    Highlights: • Elevated CO 2 increased the Zn content in suspension by reducing pH value. • Elevated CO 2 led to higher Zn accumulation in fish tissues. • Elevated CO 2 also intensified the oxidative damage to fish induced by nZnO. - Abstract: Concerns about the environmental safety of metal-based nanoparticles (MNPs) in aquatic ecosystems are increasing. Simultaneously, elevated atmospheric CO 2 levels are a serious problem worldwide, making it possible for the combined exposure of MNPs and elevated CO 2 to the ecosystem. Here we studied the toxicity of nZnO to goldfish in a water-sediment ecosystem using open-top chambers flushed with ambient (400 ± 10 μL/L) or elevated (600 ± 10 μL/L) CO 2 for 30 days. We measured the content of Zn in suspension and fish, and analyzed physiological and biochemical changes in fish tissues. Results showed that elevated CO 2 increased the Zn content in suspension by reducing the pH value of water and consequently enhanced the bioavailability and toxicity of nZnO. Elevated CO 2 led to higher accumulation of Zn in fish tissues (increased by 43.3%, 86.4% and 22.5% in liver, brain and muscle, respectively) when compared to ambient. Elevated CO 2 also intensified the oxidative damage to fish induced by nZnO, resulting in higher ROS intensity, greater contents of MDA and MT and lower GSH content in liver and brain. Our results suggest that more studies in natural ecosystems are needed to better understand the fate and toxicity of nanoparticles in future CO 2 levels.

  19. Elevated CO2 levels affect the activity of nitrate reductase and carbonic anhydrase in the calcifying rhodophyte Corallina officinalis. (United States)

    Hofmann, Laurie C; Straub, Sandra; Bischof, Kai


    The concentration of CO(2) in global surface ocean waters is increasing due to rising atmospheric CO(2) emissions, resulting in lower pH and a lower saturation state of carbonate ions. Such changes in seawater chemistry are expected to impact calcification in calcifying marine organisms. However, other physiological processes related to calcification might also be affected, including enzyme activity. In a mesocosm experiment, macroalgal communities were exposed to three CO(2) concentrations (380, 665, and 1486 µatm) to determine how the activity of two enzymes related to inorganic carbon uptake and nutrient assimilation in Corallina officinalis, an abundant calcifying rhodophyte, will be affected by elevated CO(2) concentrations. The activity of external carbonic anhydrase, an important enzyme functioning in macroalgal carbon-concentrating mechanisms, was inversely related to CO(2) concentration after long-term exposure (12 weeks). Nitrate reductase, the enzyme responsible for reduction of nitrate to nitrite, was stimulated by CO(2) and was highest in algae grown at 665 µatm CO(2). Nitrate and phosphate uptake rates were inversely related to CO(2), while ammonium uptake was unaffected, and the percentage of inorganic carbon in the algal skeleton decreased with increasing CO(2). The results indicate that the processes of inorganic carbon and nutrient uptake and assimilation are affected by elevated CO(2) due to changes in enzyme activity, which change the energy balance and physiological status of C. officinalis, therefore affecting its competitive interactions with other macroalgae. The ecological implications of the physiological changes in C. officinalis in response to elevated CO(2) are discussed.

  20. Multi-Year Leaf-Level Response to Sub-Ambient and Elevated Experimental CO2 in Betula nana (United States)

    Broere, Tom; Kürschner, Wolfram M.; Donders, Timme H.; Wagner-Cremer, Friederike


    The strong link between stomatal frequency and CO2 in woody plants is key for understanding past CO2 dynamics, predicting future change, and evaluating the significant role of vegetation in the hydrological cycle. Experimental validation is required to evaluate the long-term adaptive leaf response of C3 plants to CO2 conditions; however, studies to date have only focused on short-term single-season experiments and may not capture (1) the full ontogeny of leaves to experimental CO2 exposure or (2) the true adjustment of structural stomatal properties to CO2, which we postulate is likely to occur over several growing seasons. We conducted controlled growth chamber experiments at 150 ppmv, 450 ppmv and 800 ppmv CO2 with woody C3 shrub Betula nana (dwarf birch) over two successive annual growing seasons and evaluated the structural stomatal response to atmospheric CO2 conditions. We find that while some adjustment of leaf morphological and stomatal parameters occurred in the first growing season where plants are exposed to experimental CO2 conditions, amplified adjustment of non-plastic stomatal properties such as stomatal conductance occurred in the second year of experimental CO2 exposure. We postulate that the species response limit to CO2 of B. nana may occur around 400–450 ppmv. Our findings strongly support the necessity for multi-annual experiments in C3 perennials in order to evaluate the effects of environmental conditions and provide a likely explanation of the contradictory results between historical and palaeobotanical records and experimental data. PMID:27285314

  1. Calcifying invertebrates succeed in a naturally CO2-rich coastal habitat but are threatened by high levels of future acidification

    Directory of Open Access Journals (Sweden)

    M. Wahl


    Full Text Available CO2 emissions are leading to an acidification of the oceans. Predicting marine community vulnerability towards acidification is difficult, as adaptation processes cannot be accounted for in most experimental studies. Naturally CO2 enriched sites thus can serve as valuable proxies for future changes in community structure. Here we describe a natural analogue site in the Western Baltic Sea. Seawater pCO2 in Kiel Fjord is elevated for large parts of the year due to upwelling of CO2 rich waters. Peak pCO2 values of >230 Pa (>2300 μatm and pHNBS values of pCO2 values are ~70 Pa (~700 μatm. In contrast to previously described naturally CO2 enriched sites that have suggested a progressive displacement of calcifying auto- and heterotrophic species, the macrobenthic community in Kiel Fjord is dominated by calcifying invertebrates. We show that blue mussels from Kiel Fjord can maintain control rates of somatic and shell growth at a pCO2 of 142 Pa (1400 μatm, pHNBS = 7.7. Juvenile mussel recruitment peaks during the summer months, when high water pCO2 values of ~100 Pa (~1000 μatm prevail. Our findings indicate that calcifying keystone species may be able to cope with surface ocean pHNBS values projected for the end of this century when food supply is sufficient. However, owing to non-linear synergistic effects of future acidification and upwelling of corrosive water, peak seawater pCO2 in Kiel Fjord and many other productive estuarine habitats could increase to values >400 Pa (>4000 μatm. These changes will most likely affect calcification and recruitment, and increase external shell dissolution.

  2. Effects of elevated CO2 and temperature on yield and fruit quality of strawberry (Fragaria × ananassa Duch.) at two levels of nitrogen application. (United States)

    Sun, Peng; Mantri, Nitin; Lou, Heqiang; Hu, Ya; Sun, Dan; Zhu, Yueqing; Dong, Tingting; Lu, Hongfei


    We investigated if elevated CO(2) could alleviate the negative effect of high temperature on fruit yield of strawberry (Fragaria × ananassa Duch. cv. Toyonoka) at different levels of nitrogen and also tested the combined effects of CO(2), temperature and nitrogen on fruit quality of plants cultivated in controlled growth chambers. Results show that elevated CO(2) and high temperature caused a further 12% and 35% decrease in fruit yield at low and high nitrogen, respectively. The fewer inflorescences and smaller umbel size during flower induction caused the reduction of fruit yield at elevated CO(2) and high temperature. Interestingly, nitrogen application has no beneficial effect on fruit yield, and this may be because of decreased sucrose export to the shoot apical meristem at floral transition. Moreover, elevated CO(2) increased the levels of dry matter-content, fructose, glucose, total sugar and sweetness index per dry matter, but decreased fruit nitrogen content, total antioxidant capacity and all antioxidant compounds per dry matter in strawberry fruit. The reduction of fruit nitrogen content and antioxidant activity was mainly caused by the dilution effect of accumulated non-structural carbohydrates sourced from the increased net photosynthetic rate at elevated CO(2). Thus, the quality of strawberry fruit would increase because of the increased sweetness and the similar amount of fruit nitrogen content, antioxidant activity per fresh matter at elevated CO(2). Overall, we found that elevated CO(2) improved the production of strawberry (including yield and quality) at low temperature, but decreased it at high temperature. The dramatic fluctuation in strawberry yield between low and high temperature at elevated CO(2) implies that more attention should be paid to the process of flower induction under climate change, especially in fruits that require winter chilling for reproductive growth.

  3. Complex interplay of future climate levels of CO2, ozone and temperature on susceptibility to fungal diseases in barley

    DEFF Research Database (Denmark)

    Mikkelsen, Bolette Lind; Bagger Jørgensen, Rikke; Lyngkjær, Michael Foged


    Barley (Hordeum vulgare) was grown in different climatic environments with elevated [CO2] (700 vs 385 ppm), [O3] (60/90 vs 20 ppb) and temperature (24/19 vs 19/12°C day/night) as single factors and in combinations, to evaluate the impact of these climatic factors on photosynthesis and susceptibil......Barley (Hordeum vulgare) was grown in different climatic environments with elevated [CO2] (700 vs 385 ppm), [O3] (60/90 vs 20 ppb) and temperature (24/19 vs 19/12°C day/night) as single factors and in combinations, to evaluate the impact of these climatic factors on photosynthesis...... and susceptibility to powdery mildew and spot blotch disease. No significant increase in net CO2 assimilation rate was observed in barley grown under elevated [CO2] at ambient temperature. However, this rate was positively stimulated under elevated temperature together with a slightly higher potential quantum...... efficiency of PSII, both at ambient and elevated [CO2], suggesting that photosynthesis was not limited by [CO2] at ambient temperature. When growing under elevated temperature or [O3], infection by the biotrophic powdery mildew fungus decreased, whereas disease symptoms and growth of the toxin...

  4. Determinação de traços de Co e Co2 "em linha" por cromatografia em fase gasosa Determination of Co and Co2 on line (at low ppbV levels by gas chromatography

    Directory of Open Access Journals (Sweden)

    Rosangela Novaes de Jesus


    Full Text Available The present work describes a rapid and sensitive method for the determination of carbon monoxide and carbon dioxide at low concentration levels, on line, in ethylene and hydrogen lines. These gases were separated in a column filled with Porapak Q, converted to methane and quantified by a flame ionization detector. Some modifications were made in the injection system and in the lines of the carrier gas. The detection limits of 2,6 ppbV and 4,85 ppbV for CO and CO2, respectively, were reached after modifications.

  5. Rising sea level, temperature, and precipitation impact plant and ecosystem responses to elevated CO2 on a Chesapeake Bay wetland: review of a 28-year study. (United States)

    Drake, Bert G


    An ongoing field study of the effects of elevated atmospheric CO2 on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects of elevated CO2 on an ecosystem. Since the beginning of the study, atmospheric CO2 increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO2 to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO2 stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO2 also decreased biomass of the grass, S. patens C4. The elevated CO2 treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO2 effect on net ecosystem production, which was zero in years of severe drought. The elevated CO2 stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO2 can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency. Published

  6. Effects of CO2 Concentration on Leaf Photosynthesis and Stomatal Conductance of Potatoes Grown Under Different Irradiance Levels and Photoperiods (United States)

    Wheeler, R. M.; Fitzpatrick, A. H.; Tibbitts, T. W.


    Potato (Solanum tuberosum L.) cvs. Russet Burbank, Denali, and Norland, were grown in environmental rooms controlled at approx 350 micro mol/mol (ambient during years 1987/1988) and 1000 micro mol/mol (enriched) CO2 concentrations. Plants and electric lamps were arranged to provide two irradiance zones, 400 and 800 micro mol/mol/square m/S PPF and studies were repeated using two photoperiods (12-h light / 12-h dark and continuous light). Leaf photosynthetic rates and leaf stomatal conductance were measured using fully expanded, upper canopy leaves at weekly intervals throughout growth (21 through 84 days after transplanting). Increasing the CO2 from approx 350 to 1000 micro mol/mol under the 12-h photoperiod increased leaf photosynthetic rates by 39% at 400 micro mol/mol/square m/S PPF and 27% at 800 micro mol/mol/square m/S PPF. Increasing the CO2 from approx 350 to 1000 micro mol/mol under continuous light decreased leaf photosynthetic rates by 7% at 400 micro mol/mol/square m/S PPF and 13% at 800 micro mol/mol/square m/S PPF. Increasing the CO2 from approx 350 to 1000 micro mol/mol under the 12-h photoperiod plants decreased stomatal conductance by an average of 26% at 400 micro mol/mol/square m/S PPF and 42% at 800 micro mol/mol/square m/S PPF. Under continuous light, CO2 enrichment resulted in a small increase (2%) of stomatal conductance at 400 micro mol/mol/square m/S PPF, and a small decrease (3%) at 800 micro mol/mol/square m/S PPF. Results indicate that CO2 enrichment under the 12-h photoperiod showed the expected increase in photosynthesis and decrease in stomatal conductance for a C3 species like potato, but the decreases in leaf photosynthetic rates and minimal effect on conductance from CO2 enrichment under continuous light were not expected. The plant leaves under continuous light showed more chlorosis and some rusty flecking versus plants under the 12-h photoperiod, suggesting the continuous light was more stressful on the plants. The increased

  7. Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise (United States)

    Cherry, J.A.; McKee, K.L.; Grace, J.B.


    1. Sea-level rise, one indirect consequence of increasing atmospheric CO2, poses a major challenge to long-term stability of coastal wetlands. An important question is whether direct effects of elevated CO 2 on the capacity of marsh plants to accrete organic material and to maintain surface elevations outweigh indirect negative effects of stressors associated with sea-level rise (salinity and flooding). 2. In this study, we used a mesocosm approach to examine potential direct and indirect effects of atmospheric CO2 concentration, salinity and flooding on elevation change in a brackish marsh community dominated by a C3 species, Schoenoplectus americanus, and a C4 grass, Spartina patens. This experimental design permitted identification of mechanisms and their role in controlling elevation change, and the development of models that can be tested in the field. 3. To test hypotheses related to CO2 and sea-level rise, we used conventional anova procedures in conjunction with structural equation modelling (SEM). SEM explained 78% of the variability in elevation change and showed the direct, positive effect of S. americanus production on elevation. The SEM indicated that C3 plant response was influenced by interactive effects between CO2 and salinity on plant growth, not a direct CO2 fertilization effect. Elevated CO2 ameliorated negative effects of salinity on S. americanus and enhanced biomass contribution to elevation. 4. The positive relationship between S. americanus production and elevation change can be explained by shoot-base expansion under elevated CO 2 conditions, which led to vertical soil displacement. While the response of this species may differ under other environmental conditions, shoot-base expansion and the general contribution of C3 plant production to elevation change may be an important mechanism contributing to soil expansion and elevation gain in other coastal wetlands. 5. Synthesis. Our results revealed previously unrecognized interactions and

  8. Response of Fagus sylvatica and Picea abies to the interactive effect of neighbor identity and enhanced CO2 levels

    Czech Academy of Sciences Publication Activity Database

    Rolo, V.; Andivia, E.; Pokorný, Radek


    Roč. 29, č. 5 (2015), s. 1459-1469 ISSN 0931-1890 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : mixed-forest * climate change * root morphology * growth * non-structural carbohydrates * CO2 fumigation * plant-to-plant interactions Subject RIV: EH - Ecology, Behaviour Impact factor: 1.706, year: 2015

  9. Systematic errors in global air-sea CO2 flux caused by temporal averaging of sea-level pressure

    Directory of Open Access Journals (Sweden)

    H. Kettle


    Full Text Available Long-term temporal averaging of meteorological data, such as wind speed and air pressure, can cause large errors in air-sea carbon flux estimates. Other researchers have already shown that time averaging of wind speed data creates large errors in flux due to the non-linear dependence of the gas transfer velocity on wind speed (Bates and Merlivat, 2001. However, in general, wind speed is negatively correlated with air pressure, and a given fractional change in the pressure of dry air produces an equivalent fractional change in the atmospheric partial pressure of carbon dioxide (pCO2air. Thus low pressure systems cause a drop in pCO2air, which together with the associated high winds, promotes outgassing/reduces uptake of CO2 from the ocean. Here we quantify the errors in global carbon flux estimates caused by using monthly or climatological pressure data to calculate pCO2air (and thus ignoring the covariance of wind and pressure over the period 1990-1999, using two common parameterisations for gas transfer velocity. Results show that on average, compared with estimates made using 6 hourly pressure data, the global oceanic sink is systematically overestimated by 7% (W92 and 10% (WM99 when monthly mean pressure is used, and 9% (W92 and 12% (WM99 when climatological pressure is used.

  10. Leaf CO2 assimilation and leaf dynamics in catch crops during autumn and winter at two levels of nitrogen supply.

    NARCIS (Netherlands)

    Dam, van A.M.; Lantinga, E.A.


    This study relates the leaf CO2 assimilation and leaf dynamics of nitrogen catch crops to environmental conditions. Winter rye (Secale cereale) and fodder radish (Raphanus sativus) were grown as catch crops in an outdoor pot experiment at two rates of nitrogen supply (N2 higher than N1) in


    The ability to predict the consequences of global change is predicated on our understanding of controls of energy and material flows through ecosystems. Research was conducted at the Forest Atmosphere CO2 Transfer and Storage-1 (FACTS-1) site at Duke University. This is a flagship experiment of the ...


    NARCIS (Netherlands)


    The response of Plantago major ssp. pleiosperma plants, grown on nutrient solution in a climate chamber, to a doubling of the ambient atmospheric CO2 concentration was investigated. Total dry matter production was increased by 30 % after 3 weeks of exposure, due to a transient stimulation of the

  13. The global pyrogenic carbon cycle and its impact on the level of atmospheric CO2 over past and future centuries. (United States)

    Landry, Jean-Sébastien; Matthews, H Damon


    The incomplete combustion of vegetation and dead organic matter by landscape fires creates recalcitrant pyrogenic carbon (PyC), which could be consequential for the global carbon budget if changes in fire regime, climate, and atmospheric CO 2 were to substantially affect gains and losses of PyC on land and in oceans. Here, we included global PyC cycling in a coupled climate-carbon model to assess the role of PyC in historical and future simulations, accounting for uncertainties through five sets of parameter estimates. We obtained year-2000 global stocks of (Central estimate, likely uncertainty range in parentheses) 86 (11-154), 47 (2-64), and 1129 (90-5892) Pg C for terrestrial residual PyC (RPyC), marine dissolved PyC, and marine particulate PyC, respectively. PyC cycling decreased atmospheric CO 2 only slightly between 1751 and 2000 (by 0.8 Pg C for the Central estimate) as PyC-related fluxes changed little over the period. For 2000 to 2300, we combined Representative Concentration Pathways (RCPs) 4.5 and 8.5 with stable or continuously increasing future fire frequencies. For the increasing future fire regime, the production of new RPyC generally outpaced the warming-induced accelerated loss of existing RPyC, so that PyC cycling decreased atmospheric CO 2 between 2000 and 2300 for most estimates (by 4-8 Pg C for Central). For the stable fire regime, however, PyC cycling usually increased atmospheric CO 2 (by 1-9 Pg C for Central), and only the most extreme choice of parameters maximizing PyC production and minimizing PyC decomposition led to atmospheric CO 2 decreases under RCPs 4.5 and 8.5 (by 5-8 Pg C). Our results suggest that PyC cycling will likely reduce the future increase in atmospheric CO 2 if landscape fires become much more frequent; however, in the absence of a substantial increase in fire frequency, PyC cycling might contribute to, rather than mitigate, the future increase in atmospheric CO 2 . © 2016 John Wiley & Sons Ltd.

  14. CO2-neutral fuels (United States)

    Goede, A. P. H.


    The need for storage of renewable energy (RE) generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G) scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel cycle is

  15. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.


    Full Text Available The need for storage of renewable energy (RE generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel

  16. Effects of free-air CO2 enrichment on adventitious root development of rice under low and normal soil nitrogen levels

    Directory of Open Access Journals (Sweden)

    Chengming Sun


    Full Text Available Free air CO2 enrichment (FACE and nitrogen (N have marked effects on rice root growth, and numerical simulation can explain these effects. To further define the effects of FACE on root growth of rice, an experiment was performed, using the hybrid indica cultivar Xianyou 63. The effects of increasing atmospheric CO2 concentration [CO2], 200 μmol mol− 1 higher than ambient, on the growth of rice adventitious roots were evaluated, with two levels of N: low (LN, 125 kg ha− 1 and normal (NN, 250 kg ha− 1. The results showed a significant increase in both adventitious root number (ARN and adventitious root length (ARL under FACE treatment. The application of nitrogen also increased ARN and ARL, but these increases were smaller than that under FACE treatment. On the basis of the FACE experiment, numerical models for rice adventitious root number and length were constructed with time as the driving factor. The models illustrated the dynamic development of rice adventitious root number and length after transplanting, regulated either by atmospheric [CO2] or by N application. The simulation result was supported by statistical tests comparing experimental data from different years, and the model yields realistic predictions of root growth. These results suggest that the models have strong predictive potential under conditions of atmospheric [CO2] rises in the future.

  17. Reasons for large fluctuation of radon and CO2 levels in a dead-end passage of a karst cave (Postojna Cave, Slovenia

    Directory of Open Access Journals (Sweden)

    J. Vaupotič


    Full Text Available Measurements of radon concentration were performed at three geomorphologically different locations in Postojna Cave, Slovenia. In the part of the cave open to visitors, annual average radon activity concentrations of 3255 ± 1190 Bq m−3 and 2315 ± 1019 Bq m−3 were found at the lowest point (LP and in the Lepe jame (Beautiful Caves, BC, respectively. A much higher average of 25 020 ± 12 653 Bq m−3 was characteristic of the dead-end passage Pisani rov (Gaily Coloured Corridor, GC, in which CO2 concentration also reached very high values of 4689 ± 294 ppm in summer. Seasonal variations of radon and CO2 levels in the cave are governed by convective airflow, controlled mainly by the temperature difference between the cave and the outside atmosphere. The following additional sources of radon and CO2 were considered: (i flux of geogas from the Earth's crust through fractured rocks (radon and CO2 source, (ii clay sediments inside the passage (radon source and (iii the soil layer above the cave (radon and CO2 source.

  18. Calcification in Caribbean reef-building corals at high pCO2 levels in a recirculating ocean acidification exposure system (United States)

    Projected increases in ocean pCO2 levels are anticipated to affect calcifying organisms more rapidly and to a greater extent than other marine organisms. The effects of ocean acidification (OA) have been documented in numerous species of corals in laboratory studies, largely test...

  19. Comment on "Changes in atmospheric CO2 levels recorded by the isotopic signature of n-alkanes from plants" from K.S. Machado and S. Froehner (United States)

    Köhler, Peter; Nehrbass-Ahles, Christoph; Schmitt, Jochen; Stocker, Thomas F.; Fischer, Hubertus


    The recently published invited research article by Machado and Froehner (2017) is presenting δ13C values from sedimentary organic matter (n-alkane), measured on samples collected in the Barigui watershed (Brazil) covering the last 400 years. The derived δ13C time series based on C27n-alkane, beginning approximately in the calendar year 1600 (or 1600 CE; with CE for Common Era) until recent times is subsequently - in their Fig. 3 - compared with a record, which is believed to be a representative reconstruction of atmospheric CO2 concentrations covering approximately the last 650 years (with respect to the year 2005 CE). The final conclusion of this article, as reflected in its title, is that changes in atmospheric CO2 levels are recorded in isotopic signatures on n-alkane from plants. We argue, that this conclusion can not be drawn from the study of Machado and Froehner (2017), since what is shown in their Fig. 3 is not a time series of atmospheric CO2 concentration of the last 650 years. The authors show reconstructions of atmospheric CO2 concentrations based on Antarctic ice cores over the past 650,000 years and use them for the past 650 years by ignoring the fact that the time scale in IPCC (2007), from which, according to the caption of their Fig. 3, they took this CO2 time series, is in kyr (1 kyr = 1 kilo year = 1000 years). This is wrong and any conclusion based on this comparison is incorrect. Instead they should have used for a correct CO2 time series for the comparison with their measurements.

  20. [The influence of pH and pCO2 levels of umbilical cord blood obtained perinatally on selected parameters of stem cells]. (United States)

    Stojko, Rafał; Jendyk, Cecylia; Drosdzol-Cop, Agnieszka; Sadłocha, Marcin; Nowak-Brzezińska, Agnieszka; Boruczkowski, Dariusz; Ołdak, Tomasz


    The aim of the study was to demonstrate a correlation between pH and pCO2 levels in umbilical cord blood and the quality of the harvested material. Additionally the effect of pH and pCO2 on the number of cord blood CD34+ cells and their vitality was analyzed. The study included 50 pregnant women after vaginal delivery at term or elective cesarean section. Umbilical cord blood was collected immediately after birth. The probes were analyzed at the Polish Stem Cell Bank in Warsaw. The number of CD34+ cells ranged from 0.1-0.2 in white blood cells count over 12 thousand/ml and pH of > 7.3. If pH ranged between 7.35-7.40, the number of CD34+ was 0.3-0.4. The highest number of CD34+ cells was noted for pH of 7.30-7.35 and amounted to 0.4-0.5. Analysis of stem cell vitality showed that the highest level, over 98%, was obtained when pH was or = 7.4. The study revealed the viability of stem cells to drop to 97-98% at pH level of 7.3-7.4. Low values of CD34+ (0.01-0.09) were related to pCO2 of > 40.0 mmHg. For pCO2 or = 38 mmHg, the number of CD34+ ranged between 0.1-0.2. Viability of the umbilical cord stem cells increases along with the decrease of pH and pCO2 levels. The mode of delivery does not influence the viability of the stem cells.

  1. CO2laser stapedotomy safety: influence of laser energy and time on bone-conduction hearing levels. (United States)

    Schönfeld, Uwe; Weiming, Hu; Hofmann, Veit M; Jovanovic, Sergije; Albers, Andreas E


    Total laser energy in CO 2 stapedotomy depends on the laser settings and the amount of applications. It is unclear if the amount of total laser energy affects bone-conduction hearing thresholds and if possible effects are temporary or permanent. Alterations of bone-conduction hearing thresholds after single or multiple-shot CO 2 laser stapedotomy were analyzed between 1 and 3 weeks and 1.5-6 months after primary (n = 501) or revision surgeries (n = 153) and correlated to time, laser energy, frequency, surgical technique, and pathology encountered in revision stapedotomy. In both time periods, most patients showed a lower bone-conduction threshold in the four-tone puretone average (PTA) at frequencies of 0.5, 1, 2, and 3 kHz that further improved over time. Between 1 and 3 weeks, the improvement was significant in subgroups with cumulative energies lower 1 J and successful one-shot technique or in revisions without laser application. The remaining subgroups with higher total energies showed significant improvements between 1.5 and 6 months. At 4 and 8 kHz, significant improvements were found during 1.5-6 months after primary and revision surgery independent of the used energy. Repeated CO 2 laser applications showed no impairment in bone-conduction thresholds and can thus be considered as safe. In most patients, significant, yet unexplained, improvements in bone-conduction hearing thresholds were noticed in a time- and energy-related pattern.

  2. CO2-Neutral Fuels

    NARCIS (Netherlands)

    Goede, A.; van de Sanden, M. C. M.


    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy

  3. CO2 sequestration

    International Nuclear Information System (INIS)

    Favre, E.; Jammes, L.; Guyot, F.; Prinzhofer, A.; Le Thiez, P.


    This document presents the summary of a conference-debate held at the Academie des Sciences (Paris, France) on the topic of CO 2 sequestration. Five papers are reviewed: problems and solutions for the CO 2 sequestration; observation and surveillance of reservoirs; genesis of carbonates and geological storage of CO 2 ; CO 2 sequestration in volcanic and ultra-basic rocks; CO 2 sequestration, transport and geological storage: scientific and economical perspectives

  4. Late winter under ice pelagic microbial communities in the high Arctic Ocean and the impact of short-term exposure to elevated CO2 levels. (United States)

    Monier, Adam; Findlay, Helen S; Charvet, Sophie; Lovejoy, Connie


    Polar Oceans are natural CO2 sinks because of the enhanced solubility of CO2 in cold water. The Arctic Ocean is at additional risk of accelerated ocean acidification (OA) because of freshwater inputs from sea ice and rivers, which influence the carbonate system. Winter conditions in the Arctic are of interest because of both cold temperatures and limited CO2 venting to the atmosphere when sea ice is present. Earlier OA experiments on Arctic microbial communities conducted in the absence of ice cover, hinted at shifts in taxa dominance and diversity under lowered pH. The Catlin Arctic Survey provided an opportunity to conduct in situ, under-ice, OA experiments during late Arctic winter. Seawater was collected from under the sea ice off Ellef Ringnes Island, and communities were exposed to three CO2 levels for 6 days. Phylogenetic diversity was greater in the attached fraction compared to the free-living fraction in situ, in the controls and in the treatments. The dominant taxa in all cases were Gammaproteobacteria but acidification had little effect compared to the effects of containment. Phylogenetic net relatedness indices suggested that acidification may have decreased the diversity within some bacterial orders, but overall there was no clear trend. Within the experimental communities, alkalinity best explained the variance among samples and replicates, suggesting subtle changes in the carbonate system need to be considered in such experiments. We conclude that under ice communities have the capacity to respond either by selection or phenotypic plasticity to heightened CO2 levels over the short term.

  5. Low-Computation Strategies for Extracting CO2 Emission Trends from Surface-Level Mixing Ratio Observations (United States)

    Shusterman, A.; Kim, J.; Lieschke, K.; Newman, C.; Cohen, R. C.


    Global momentum is building for drastic, regulated reductions in greenhouse gas emissions over the coming decade. With this increasing regulation comes a clear need for increasingly sophisticated monitoring, reporting, and verification (MRV) strategies capable of enforcing and optimizing emissions-related policy, particularly as it applies to urban areas. Remote sensing and/or activity-based emission inventories can offer MRV insights for entire sectors or regions, but are not yet sophisticated enough to resolve unexpected trends in specific emitters. Urban surface monitors can offer the desired proximity to individual greenhouse gas sources, but due to the densely-packed nature of typical urban landscapes, surface observations are rarely representative of a single source. Most previous efforts to decompose these complex signals into their contributing emission processes have involved inverse atmospheric modeling techniques, which are computationally intensive and believed to depend heavily on poorly understood a priori estimates of error covariance. Here we present a number of transparent, low-computation approaches for extracting source-specific emissions estimates from signals with a variety of nearfield influences. Using observations from the first several years of the BErkeley Atmospheric CO2 Observation Network (BEACO2N), we demonstrate how to exploit strategic pairings of monitoring "nodes," anomalous wind conditions, and well-understood temporal variations to hone in on specific CO2 sources of interest. When evaluated against conventional, activity-based bottom-up emission inventories, these strategies are seen to generate quantitatively rigorous emission estimates. With continued application as the BEACO2N data set grows in time and space, these approaches offer a promising avenue for optimizing greenhouse gas mitigation strategies into the future.

  6. Elevated CO2 increases Cs uptake and alters microbial communities and biomass in the rhizosphere of Phytolacca americana Linn (pokeweed) and Amaranthus cruentus L. (purple amaranth) grown on soils spiked with various levels of Cs

    International Nuclear Information System (INIS)

    Song, Ningning; Zhang, Ximei; Wang, Fangli; Zhang, Changbo; Tang, Shirong


    General concern about increasing global atmospheric CO 2 levels owing to the ongoing fossil fuel combustion and elevated levels of radionuclides in the environment, has led to growing interest in the responses of plants to interactive effects of elevated CO 2 and radionuclides in terms of phytoremediation and food safety. To assess the combined effects of elevated CO 2 and cesium contamination on plant biomass, microbial activities in the rhizosphere soil and Cs uptake, Phytolacca americana Linn (pokeweed, C3 specie) and Amaranthus cruentus L. (purple amaranth, C4 specie) were grown in pots of soils containing five levels of cesium (0, 100, 300, 500 and 1000 mg Cs kg −1 ) under two levels of CO 2 (360 and 860 μL L −1 , respectively). Shoot and root biomass of P. americana and Amaranthus crentus was generally higher under elevated CO 2 than under ambient CO 2 for all treatments. Both plant species exhibited higher Cs concentration in the shoots and roots under elevated CO 2 than ambient CO 2 . For P. americana grown at 0, 100, 300, 500 and 1000 mg Cs kg −1 , the increase magnitude of Cs concentration due to elevated CO 2 was 140, 18, 11, 34 and 15% in the shoots, and 150, 20, 14, 15 and 19% in the roots, respectively. For A. cruentus, the corresponding value was 118, 28, 21, 14 and 17% in the shoots, and 126, 6, 11, 17 and 22% in the roots, respectively. Higher bioaccumulation factors were noted for both species grown under elevated CO 2 than ambient CO 2 . The populations of bacteria, actinomycetes and fungi, and the microbial C and N in the rhizosphere soils of both species were higher at elevated CO 2 than at ambient CO 2 with the same concentration of Cs. The results suggested that elevated CO 2 significantly affected plant biomass, Cs uptake, soil C and N concentrations, and community composition of soil microbes associated with P. americana and A. cruentus roots. The knowledge gained from this investigation constitutes an important advancement in

  7. CO2 blood test (United States)

    ... page: // CO2 blood test To use the sharing features on this page, ... a substance called bicarbonate (HCO3-). Therefore, the CO2 blood test is really a measure of your blood bicarbonate ...

  8. The other GHG : steps taken to reduce CO2 emissions may contribute to increased levels of water vapour in the atmosphere

    International Nuclear Information System (INIS)

    Collison, M.


    As a result of the Intergovernmental Panel on Climate Change (IPCC), the Canadian oil and gas industry and government are now in the midst of a massive overhaul of hydrocarbon energy use and carbon dioxide (CO 2 ) management. However, human-enhanced water evaporation (HEWE) may also be a significant contributor to global climate warming. Human-caused distortions of the hydrological cycle can cause multiple localized weather disturbances. There is currently a thousand times more water vapor being emitted than CO 2 , and this is contributing to increased rainfall levels around the world. Expansion of the agriculture and growth of industry has caused significant diversions and redistributions of water. Most of the water used is evaporated in the northern hemisphere. Climate modellers are needed to analyze the impacts of human-enhanced water evaporation local climates and weather. The main sources of water emissions are government-controlled energy projects and subsidized irrigation projects. Current levels of water vapour emissions are between 10 and 100 times the value of warming per tonne as CO 2 . Details of various research projects to use salt water as a fuel for vehicles was provided, as well as methods of improving the water-gas shift reaction method of hydrogen production. 2 figs

  9. CO2 laser development

    International Nuclear Information System (INIS)



    The research and development programs on high-energy, short-pulse CO 2 lasers were begun at LASL in 1969. Three large systems are now either operating or are being installed. The Single-Beam System (SBS), a four-stage prototype, was designed in 1971 and has been in operation since 1973 with an output energy of 250 J in a 1-ns pulse with an on-target intensity of 3.5 x 10 14 W/cm 2 . The Dual-Beam System (DBS), now in the final stages of electrical and optical checkout, will provide about ten times more power for two-beam target irradiation experiments. Four such dual-beam modules are being installed in the Laser-Fusion Laboratory to provide an Eight-Beam System (EBS) scheduled for operation at the 5- to 10-TW level in 1977. A fourth system, a 100- to 200-TW CO 2 laser, is being designed for the High-Energy Gas Laser Facility (HEGLF) program

  10. Foraminiferal calcification and CO2 (United States)

    Nooijer, L. D.; Toyofuku, T.; Reichart, G. J.


    Ongoing burning of fossil fuels increases atmospheric CO2, elevates marine dissolved CO2 and decreases pH and the saturation state with respect to calcium carbonate. Intuitively this should decrease the ability of CaCO3-producing organisms to build their skeletons and shells. Whereas on geological time scales weathering and carbonate deposition removes carbon from the geo-biosphere, on time scales up to thousands of years, carbonate precipitation increases pCO2 because of the associated shift in seawater carbon speciation. Hence reduced calcification provides a potentially important negative feedback on increased pCO2 levels. Here we show that foraminifera form their calcium carbonate by active proton pumping. This elevates the internal pH and acidifies the direct foraminiferal surrounding. This also creates a strong pCO2 gradient and facilitates the uptake of DIC in the form of carbon dioxide. This finding uncouples saturation state from calcification and predicts that the added carbon due to ocean acidification will promote calcification by these organisms. This unknown effect could add substantially to atmospheric pCO2 levels, and might need to be accounted for in future mitigation strategies.

  11. Consequences of elevated temperature and pCO2 on insect folivory at the ecosystem level: perspectives from the fossil record. (United States)

    Currano, Ellen D; Laker, Rachel; Flynn, Andrew G; Fogt, Kari K; Stradtman, Hillary; Wing, Scott L


    Paleoecological studies document the net effects of atmospheric and climate change in a natural laboratory over timescales not accessible to laboratory or ecological studies. Insect feeding damage is visible on well-preserved fossil leaves, and changes in leaf damage through time can be compared to environmental changes. We measured percent leaf area damaged on four fossil leaf assemblages from the Bighorn Basin, Wyoming, that range in age from 56.1 to 52.65 million years (Ma). We also include similar published data from three US sites 49.4 to ~45 Ma in our analyses. Regional climate was subtropical or warmer throughout this period, and the second oldest assemblage (56 Ma) was deposited during the Paleocene-Eocene Thermal Maximum (PETM), a geologically abrupt global warming event caused by massive release of carbon into the atmosphere. Total and leaf-chewing damage are highest during the PETM, whether considering percent area damaged on the bulk flora, the average of individual host plants, or a single plant host that occurs at multiple sites. Another fossil assemblage in our study, the 52.65 Ma Fifteenmile Creek paleoflora, also lived during a period of globally high temperature and pCO 2, but does not have elevated herbivory. Comparison of these two sites, as well as regression analyses conducted on the entire dataset, demonstrates that, over long timescales, temperature and pCO 2 are uncorrelated with total insect consumption at the ecosystem level. Rather, the most important factor affecting herbivory is the relative abundance of plants with nitrogen-fixing symbionts. Legumes dominate the PETM site; their prevalence would have decreased nitrogen limitation across the ecosystem, buffering generalist herbivore populations against decreased leaf nutritional quality that commonly occurs at high pCO 2. We hypothesize that nitrogen concentration regulates the opposing effects of elevated temperature and CO 2 on insect abundance and thereby total insect consumption

  12. NEOTEC: Negative-CO2-Emissions Marine Energy With Direct Mitigation of Global Warming, Sea-Level Rise and Ocean Acidification (United States)

    Rau, G. H.; Baird, J.; Noland, G.


    The vertical thermal energy potential in the ocean is a massive renewable energy resource that is growing due to anthropogenic warming of the surface and near-surface ocean. The conversion of this thermal energy to useful forms via Ocean Thermal Energy Conversion (OTEC) has been demonstrated over the past century, albeit at small scales. Because OTEC removes heat from the surface ocean, this could help directly counter ongoing, deleterious ocean/atmosphere warming. The only other climate intervention that could do this is solar radiation "geoengineering". Conventional OTEC requires energy intensive, vertical movement of seawater resulting in ocean and atmospheric chemistry alteration, but this can be avoided via more energy efficient, vertical closed-cycle heating and cooling of working fluid like CO2 or NH3. An energy carrier such as H2 is required to transport energy optimally extracted far offshore, and methods of electrochemically generating H2 while also consuming CO2 and converting it to ocean alkalinity have been demonstrated. The addition of such alkalinity to the ocean would provide vast, stable, carbon storage, while also helping chemically counter the effects of ocean acidification. The process might currently be profitable given the >$100/tonne CO2 credit offered by California's Low Carbon Fuel Standard for transportation fuels like H2. Negative-Emissions OTEC, NEOTEC, thus can potentially provide constant, cost effective, high capacity, negative-emissions energy while: a) reducing surface ocean heat load, b) reducing thermal ocean expansion and sea-level rise, c) utilizing a very large, natural marine carbon storage reservoir, and d) helping mitigate ocean acidification. The technology also avoids the biophysical and land use limitations posed by negative emissions methods that rely on terrestrial biology, such as afforestation and BECCS. NEOTEC and other marine-based, renewable energy and CO2 removal approaches could therefore greatly increase the

  13. Global atmospheric change and herbivory: Effects of elevated levels of UV-B radiation, atmospheric CO2 and temperature on boreal woody plants and their herbivores

    International Nuclear Information System (INIS)

    Veteli, T.


    The aim of this study was to assess the effects of elevated ultraviolet-B radiation (UV-B, 280- 320 nm), atmospheric CO 2 , temperature and soil nitrogen level on the growth and chemical quality of boreal deciduous woody plants and on performance of the herbivorous insects feeding on them. Eggs and larvae of Operophtera brumata (L.) (Lepidoptera, Geometridae) were subjected to elevated UV-B radiation in the laboratory. Two willow species, Salix phylicifolia L. (Salicaceae) and S. myrsinifolia Salisb., were grown in an UV-B irradiation field where the responses of both plants and their herbivorous insects were monitored. S. myrsinifolia, Betula pendula Ehrh. (Betulaceae) and B. pubescens Roth. were subjected to elevated CO 2 and temperature and different fertilisation levels in closed-top climatic chambers. To assess the indirect effects of the different treatments, the leaves of experimental willows and birches were fed to larvae of Phratora vitellinae (L.) (Coleoptera, Chrysomelidae) and adults of Agellastica alni L. in the laboratory. Elevated UV-B radiation significantly decreased the survival and performance of eggs and larvae of O. brumata. It also increased concentrations of some flavonoids and phenolic acids in S. myrsinifolia and S. phylicifolia, while the low-UV-B- absorbing phenolics, e. g. condensed tannins, gallic acid derivatives and salicylates, either decreased or remained unaffected. Both the height growth and biomass of one S. phylicifolia clone was sensitive to elevated levels of UV-B radiation. Abundance of adults and larvae of a willow- feeding leaf beetle, P. vitellinae, was increased under elevated UV-B; but this did not lead to increased leaf damage on the host plants. There were no significant differences in performance of the larvae feeding on differentially treated willow leaves, but adult A. alni preferred UV-B-treated leaves to ambient control leaves. Elevated CO 2 and temperature significantly increased the height growth of S

  14. CO2low-level laser therapy has an early but not delayed pain effect during experimental tooth movement. (United States)

    Deguchi, T; Kim, D G; Kamioka, H


    To test the hypothesis that the use of low-level laser therapy (LLLT) reduces elevated pain by controlling the release of neurochemicals during orthodontic tooth movement. Department of Orthodontics and Dentofacial Orthopedics, Okayama University. Sixty-five Sprague Dawley rats were subjected to tooth movement and LLLT. Adult Sprague Dawley rats were used in this study. Groups included day 0 controls, irradiation only controls and with or without irradiation sacrificed at 1, 3, 5, 7 and 14 days after tooth movement (n=5 each, total n=65). Tooth movement was achieved by insertion of an elastic module between molar teeth. Immunohistochemistry for CD-11b, GFAP and c-fos in the brain stem was performed. Stains were quantified by constructing a three-dimensional image using IMARIS, and counted using NEURON TRACER and WinROOF software. Two-way ANOVA followed by a Tukey's post hoc test (PLow-level laser therapy may reduce early neurochemical markers but have no effect on delayed pain neurochemical markers after tooth movement. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.


    Energy Technology Data Exchange (ETDEWEB)

    A.V.G. Chizmeshya; M.J. McKelvy; J.B. Adams


    Fossil fuels, especially coal, can support the energy demands of the world for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Permanent and safe methods for CO{sub 2} capture and disposal/storage need to be developed. Mineralization of stationary-source CO{sub 2} emissions as carbonates can provide such safe capture and long-term sequestration. Mg-rich lamellar hydroxide mineral carbonation is a leading process candidate, which generates the stable naturally occurring mineral magnesite (MgCO{sub 3}) and water. Key to process cost and viability are the carbonation reaction rate and its degree of completion. This process, which involves simultaneous dehydroxylation and carbonation is very promising, but far from optimized. In order to optimize the dehydroxylation/carbonation process, an atomic-level understanding of the mechanisms involved is needed. In this investigation Mg(OH){sub 2} was selected as a model Mg-rich lamellar hydrocide carbonation feedstock material due to its chemical and structural simplicity. Since Mg(OH){sub 2} dehydroxylation is intimately associated with the carbonation process, its mechanisms are also of direct interest in understanding and optimizing the process. The aim of the current innovative concepts project is to develop a specialized advanced computational methodology to complement the ongoing experimental inquiry of the atomic level processes involved in CO{sub 2} mineral sequestration. The ultimate goal is to integrate the insights provided by detailed predictive simulations with the data obtained from optical microscopy, FESEM, ion beam analysis, SIMS, TGA, Raman, XRD, and C and H elemental analysis. The modeling studies are specifically designed to enhance the synergism with, and complement the analysis of, existing mineral-CO{sub 2} reaction process studies being carried out under DOE UCR Grant DE-FG2698-FT40112. Direct contact between the simulations and the experimental

  16. Photosynthetic induction in a C4, Flaveria trinervia. I. Initial products of 14CO2 assimilation and levels of whole leaf C4 metabolites

    International Nuclear Information System (INIS)

    Moore, B.D.; Edwards, G.E.


    Labeling patterns from 14 CO 2 pulses to leaves and whole leaf metabolite contents were examined during photosynthetic induction in Flaveria trinervia, a C 4 dicot of the NADP-malic enzyme subgroup. During the first one to two minutes of illumination, malate was the primary initial product of 14 CO 2 assimilation (about 77% of total 14 C incorporated). After about 5 minutes of illumination, the proportion of initial label to aspartate increased from 16 to 66%, and then gradually declined during the following 7 to 10 minutes of illumination. Nutrition experiments showed that the increase in 14 CO 2 partitioning to aspartate was delayed about 2.5 minutes in plants grown with limiting N, and was highly dampened in plants previously treated 10 to 12 days with ammonia as the sole N source. Measurements of C 4 leaf metabolites revealed several transients in metabolite pools during the first few minutes of illumination, and subsequently, more gradual adjustments in pool sizes. These include a large initial decrease in malate (about 1.6 micromoles per milligram chlorophyll) and a small initial decrease in pyruvate. There was a transient increase in alanine levels after 1 minute of illumination, which was followed by a gradual, prolonged decrease during the remainder of the induction period. Total leaf aspartate decreased initially, but temporarily doubled in amount between 5 and 10 minutes of illumination (after its surge as a primary product). These results are discussed in terms of a plausible sequence of metabolic events which lead to the formation of the intercellular metabolite gradients required in C 4 photosynthesis

  17. Outsourcing CO2 Emissions (United States)

    Davis, S. J.; Caldeira, K. G.


    CO2 emissions from the burning of fossil fuels are the primary cause of global warming. Much attention has been focused on the CO2 directly emitted by each country, but relatively little attention has been paid to the amount of emissions associated with consumption of goods and services in each country. This consumption-based emissions inventory differs from the production-based inventory because of imports and exports of goods and services that, either directly or indirectly, involved CO2 emissions. Using the latest available data and reasonable assumptions regarding trans-shipment of embodied carbon through third-party countries, we developed a global consumption-based CO2 emissions inventory and have calculated associated consumption-based energy and carbon intensities. We find that, in 2004, 24% of CO2 emissions are effectively outsourced to other countries, with much of the developed world outsourcing CO2 emissions to emerging markets, principally China. Some wealthy countries, including Switzerland and Sweden, outsource over half of their consumption-based emissions, with many northern Europeans outsourcing more than three tons of emissions per person per year. The United States is both a big importer and exporter of emissions embodied in trade, outsourcing >2.6 tons of CO2 per person and at the same time as >2.0 tons of CO2 per person are outsourced to the United States. These large flows indicate that CO2 emissions embodied in trade must be taken into consideration when considering responsibility for increasing atmospheric greenhouse gas concentrations.

  18. The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) Contribution to CMIP6: Investigation of Sea-Level and Ocean Climate Change in Response to CO2 Forcing (United States)

    Gregory, Jonathan M.; Bouttes, Nathaelle; Griffies, Stephen M.; Haak, Helmuth; Hurlin, William J.; Jungclaus, Johann; Kelley, Maxwell; Lee, Warren G.; Marshall, John; Romanou, Anastasia; hide


    The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP) aims to investigate the spread in simulations of sea-level and ocean climate change in response to CO2 forcing by atmosphere-ocean general circulation models (AOGCMs). It is particularly motivated by the uncertainties in projections of ocean heat uptake, global-mean sealevel rise due to thermal expansion and the geographical patterns of sea-level change due to ocean density and circulation change. FAFMIP has three tier-1 experiments, in which prescribed surface flux perturbations of momentum, heat and freshwater respectively are applied to the ocean in separate AOGCM simulations. All other conditions are as in the pre-industrial control. The prescribed fields are typical of pattern and magnitude of changes in these fluxes projected by AOGCMs for doubled CO2 concentration. Five groups have tested the experimental design with existing AOGCMs. Their results show diversity in the pattern and magnitude of changes, with some common qualitative features. Heat and water flux perturbation cause the dipole in sea-level change in the North Atlantic, while momentum and heat flux perturbation cause the gradient across the Antarctic Circumpolar Current. The Atlantic meridional overturning circulation (AMOC) declines in response to the heat flux perturbation, and there is a strong positive feedback on this effect due to the consequent cooling of sea-surface temperature in the North Atlantic, which enhances the local heat input to the ocean. The momentum and water flux perturbations do not substantially affect the AMOC. Heat is taken up largely as a passive tracer in the Southern Ocean, which is the region of greatest heat input, while the weakening of the AMOC causes redistribution of heat towards lower latitudes. Future analysis of these and other phenomena with the wider range of CMIP6 FAFMIP AOGCMs will benefit from new diagnostics of temperature and salinity tendencies, which will enable investigation of the model

  19. Reducing cement's CO2 footprint (United States)

    van Oss, Hendrik G.


    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  20. Rare-Earth Fourth-Order Multipole Moment in Cubic ErCo2 Probed by Linear Dichroism in Core-Level Photoemission (United States)

    Abozeed, Amina A.; Kadono, Toshiharu; Sekiyama, Akira; Fujiwara, Hidenori; Higashiya, Atsushi; Yamasaki, Atsushi; Kanai, Yuina; Yamagami, Kohei; Tamasaku, Kenji; Yabashi, Makina; Ishikawa, Tetsuya; Andreev, Alexander V.; Wada, Hirofumi; Imada, Shin


    We developed a method to experimentally quantify the fourth-order multipole moment of the rare-earth 4f orbital. Linear dichroism (LD) in the Er 3d5/2 core-level photoemission spectra of cubic ErCo2 was measured using bulk-sensitive hard X-ray photoemission spectroscopy. Theoretical calculation reproduced the observed LD, and the result showed that the observed result does not contradict the suggested Γ 83 ground state. Theoretical calculation further showed a linear relationship between the LD size and the size of the fourth-order multipole moment of the Er3+ ion, which is proportional to the expectation value , where Onm are the Stevens operators. These analyses indicate that the LD in 3d photoemission spectra can be used to quantify the average fourth-order multipole moment of rare-earth atoms in a cubic crystal electric field.

  1. Interactive effects of elevated temperature and CO2 levels on energy metabolism and biomineralization of marine bivalves Crassostrea virginica and Mercenaria mercenaria. (United States)

    Ivanina, Anna V; Dickinson, Gary H; Matoo, Omera B; Bagwe, Rita; Dickinson, Ashley; Beniash, Elia; Sokolova, Inna M


    The continuing increase of carbon dioxide (CO2) levels in the atmosphere leads to increases in global temperatures and partial pressure of CO2 (PCO2) in surface waters, causing ocean acidification. These changes are especially pronounced in shallow coastal and estuarine waters and are expected to significantly affect marine calcifiers including bivalves that are ecosystem engineers in estuarine and coastal communities. To elucidate potential effects of higher temperatures and PCO2 on physiology and biomineralization of marine bivalves, we exposed two bivalve species, the eastern oysters Crassostrea virginica and the hard clams Mercenaria mercenaria to different combinations of PCO2 (~400 and 800μatm) and temperatures (22 and 27°C) for 15weeks. Survival, bioenergetic traits (tissue levels of lipids, glycogen, glucose and high energy phosphates) and biomineralization parameters (mechanical properties of the shells and activity of carbonic anhydrase, CA) were determined in clams and oysters under different temperature and PCO2 regimes. Our analysis showed major inter-species differences in shell mechanical traits and bioenergetics parameters. Elevated temperature led to the depletion of tissue energy reserves indicating energy deficiency in both species and resulted in higher mortality in oysters. Interestingly, while elevated PCO2 had a small effect on the physiology and metabolism of both species, it improved survival in oysters. At the same time, a combination of high temperature and elevated PCO2 lead to a significant decrease in shell hardness in both species, suggesting major changes in their biomineralization processes. Overall, these studies show that global climate change and ocean acidification might have complex interactive effects on physiology, metabolism and biomineralization in coastal and estuarine marine bivalves. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Degradation of kresoxim-methyl in soil: impact of varying moisture, organic matter, soil sterilization, soil type, light and atmospheric CO2 level. (United States)

    Khandelwal, Ashish; Gupta, Suman; Gajbhiye, Vijay T; Varghese, Eldho


    In the present investigation, persistence of kresoxim-methyl (a broad spectrum strobilurin fungicide) was studied in two different soil types of India namely Inceptisol and Ultisol. Results revealed that kresoxim-methyl readily form acid metabolite in soil. Therefore, residues of kresoxim-methyl were quantified on the basis of parent molecule alone and sum total of kresoxim-methyl and its acid metabolite. Among the two soil types, kresoxim-methyl and total residues dissipated at a faster rate in Inceptisol (T1/2 0.9 and 33.8d) than in Ultisol (T1/2 1.5 and 43.6d). Faster dissipation of kresoxim-methyl and total residues was observed in submerged soil conditions (T1/2 0.5 and 5.2d) followed by field capacity (T1/2 0.9 and 33.8d) and air dry (T1/2 2.3 and 51.0d) conditions. Residues also dissipated faster in 5% sludge amended soil (T1/2 0.7 and 21.1d) and on Xenon-light exposure (T1/2 0.5 and 8.0d). Total residues of kresoxim-methyl dissipated at a faster rate under elevated CO2 condition (∼550μLL(-)(1)) than ambient condition (∼385μLL(-)(1)). The study suggests that kresoxim-methyl alone has low persistence in soil. Because of the slow dissipation of acid metabolite, the total residues (kresoxim-methyl+acid metabolite) persist for a longer period in soil. Statistical analysis using SAS 9.3 software and Duncan's Multiple Range Test (DMRT) revealed the significant effect of moisture regime, organic matter, microbial population, soil type, light exposure and atmospheric CO2 level on the dissipation of kresoxim-methyl from soil (at 95% confidence level p<0.0001). Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. CO2 chemical valorization

    International Nuclear Information System (INIS)

    Kerlero De Rosbo, Guillaume; Rakotojaona, Loic; Bucy, Jacques de; Clodic, Denis; Roger, Anne-Cecile; El Khamlichi, Aicha; Thybaud, Nathalie; Oeser, Christian; Forti, Laurent; Gimenez, Michel; Savary, David; Amouroux, Jacques


    Facing global warming, different technological solutions exist to tackle carbon dioxide (CO 2 ) emissions. Some inevitable short term emissions can be captured so as to avoid direct emissions into the atmosphere. This CO 2 must then be managed and geological storage seems to currently be the only way of dealing with the large volumes involved. However, this solution faces major economic profitability and societal acceptance challenges. In this context, alternative pathways consisting in using CO 2 instead of storing it do exist and are generating growing interest. This study ordered by the French Environment and Energy Management Agency (ADEME), aims at taking stock of the different technologies used for the chemical conversion of CO 2 in order to have a better understanding of their development potential by 2030, of the conditions in which they could be competitive and of the main actions to be implemented in France to foster their emergence. To do this, the study was broken down into two main areas of focus: The review and characterization of the main CO 2 chemical conversion routes for the synthesis of basic chemical products, energy products and inert materials. This review includes a presentation of the main principles underpinning the studied routes, a preliminary assessment of their performances, advantages and drawbacks, a list of the main R and D projects underway, a focus on emblematic projects as well as a brief analysis of the markets for the main products produced. Based on these elements, 3 routes were selected from among the most promising by 2030 for an in-depth modelling and assessment of their energy, environmental and economic performances. The study shows that the processes modelled do have favorable CO 2 balances (from 1 to 4 t-CO 2 /t-product) and effectively constitute solutions to reduce CO 2 emissions, despite limited volumes of CO 2 in question. Moreover, the profitability of certain solutions will remain difficult to reach, even with an

  4. Growth, reproductive phenology and yield responses of a potential biofuel plant, Jatropha curcas grown under projected 2050 levels of elevated CO2. (United States)

    Kumar, Sumit; Chaitanya, Bharatula S K; Ghatty, Sreenivas; Reddy, Attipalli R


    Jatropha (Jatropha curcas) is a non-edible oil producing plant which is being advocated as an alternative biofuel energy resource. Its ability to grow in diverse soil conditions and minimal requirements of essential agronomical inputs compared with other oilseed crops makes it viable for cost-effective advanced biofuel production. We designed a study to investigate the effects of elevated carbon dioxide concentration ([CO(2)]) (550 ppm) on the growth, reproductive development, source-sink relationships, fruit and seed yield of J. curcas. We report, for the first time that elevated CO(2) significantly influences reproductive characteristics of Jatropha and improve its fruit and seed yields. Net photosynthetic rate of Jatropha was 50% higher in plants grown in elevated CO(2) compared with field and ambient CO(2) -grown plants. The study also revealed that elevated CO(2) atmosphere significantly increased female to male flower ratio, above ground biomass and carbon sequestration potential in Jatropha (24 kg carbon per tree) after 1 year. Our data demonstrate that J. curcas was able to sustain enhanced rate of photosynthesis in elevated CO(2) conditions as it had sufficient sink strength to balance the increased biomass yields. Our study also elucidates that the economically important traits including fruit and seed yield in elevated CO(2) conditions were significantly high in J. curcas that holds great promise as a potential biofuel tree species for the future high CO(2) world. © 2014 Scandinavian Plant Physiology Society.

  5. CO2 cycle (United States)

    Titus, Timothy N.; Byrne, Shane; Colaprete, Anthony; Forget, Francois; Michaels, Timothy I.; Prettyman, Thomas H.


    This chapter discusses the use of models, observations, and laboratory experiments to understand the cycling of CO2 between the atmosphere and seasonal Martian polar caps. This cycle is primarily controlled by the polar heat budget, and thus the emphasis here is on its components, including solar and infrared radiation, the effect of clouds (water- and CO2-ice), atmospheric transport, and subsurface heat conduction. There is a discussion about cap properties including growth and regression rates, albedos and emissivities, grain sizes and dust and/or water-ice contamination, and curious features like cold gas jets and araneiform (spider-shaped) terrain. The nature of the residual south polar cap is discussed as well as its long-term stability and ability to buffer atmospheric pressures. There is also a discussion of the consequences of the CO2 cycle as revealed by the non-condensable gas enrichment observed by Odyssey and modeled by various groups.

  6. CO2NNIE

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Andersen, Ove; Lewis-Kelham, Edwin


    We propose a system for calculating the personalized annual fuel consumption and CO2 emissions from transportation. The system, named CO2NNIE, estimates the fuel consumption on the fastest route between the frequent destinations of the user. The travel time and fuel consumption estimated are based...... on 3.8 billion GPS records from 16 thousand cars and 198 million records from 218 cars annotated with fuel consumption data, respectively. The fuel consumption estimates from the system are validated using fuel-pump data. We find that estimates have good accuracy, i.e., are generally within 10......% of the actual fuel consumption (4.6% deviation on average). We conclude, that the system provides new detailed information on CO2 emissions and fuel consumption for any make and model....

  7. The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP contribution to CMIP6: investigation of sea-level and ocean climate change in response to CO2 forcing

    Directory of Open Access Journals (Sweden)

    J. M. Gregory


    Full Text Available The Flux-Anomaly-Forced Model Intercomparison Project (FAFMIP aims to investigate the spread in simulations of sea-level and ocean climate change in response to CO2 forcing by atmosphere–ocean general circulation models (AOGCMs. It is particularly motivated by the uncertainties in projections of ocean heat uptake, global-mean sea-level rise due to thermal expansion and the geographical patterns of sea-level change due to ocean density and circulation change. FAFMIP has three tier-1 experiments, in which prescribed surface flux perturbations of momentum, heat and freshwater respectively are applied to the ocean in separate AOGCM simulations. All other conditions are as in the pre-industrial control. The prescribed fields are typical of pattern and magnitude of changes in these fluxes projected by AOGCMs for doubled CO2 concentration. Five groups have tested the experimental design with existing AOGCMs. Their results show diversity in the pattern and magnitude of changes, with some common qualitative features. Heat and water flux perturbation cause the dipole in sea-level change in the North Atlantic, while momentum and heat flux perturbation cause the gradient across the Antarctic Circumpolar Current. The Atlantic meridional overturning circulation (AMOC declines in response to the heat flux perturbation, and there is a strong positive feedback on this effect due to the consequent cooling of sea-surface temperature in the North Atlantic, which enhances the local heat input to the ocean. The momentum and water flux perturbations do not substantially affect the AMOC. Heat is taken up largely as a passive tracer in the Southern Ocean, which is the region of greatest heat input, while the weakening of the AMOC causes redistribution of heat towards lower latitudes. Future analysis of these and other phenomena with the wider range of CMIP6 FAFMIP AOGCMs will benefit from new diagnostics of temperature and salinity tendencies, which will enable

  8. CO2-strategier

    DEFF Research Database (Denmark)

    Jørgensen, Michael Søgaard


    I 2007 henvendte Lyngby-Taarbæk kommunens Agenda 21 koordinator sig til Videnskabsbutikken og spurgte om der var interesse for at samarbejde om CO2-strategier. Da Videnskabsbutikken DTU er en åben dør til DTU for borgerne og deres organisationer, foreslog Videnskabsbutikken DTU at Danmarks...

  9. Explaining CO2 fluctuations observed in snowpacks (United States)

    Graham, Laura; Risk, David


    Winter soil carbon dioxide (CO2) respiration is a significant and understudied component of the global carbon (C) cycle. Winter soil CO2 fluxes can be surprisingly variable, owing to physical factors such as snowpack properties and wind. This study aimed to quantify the effects of advective transport of CO2 in soil-snow systems on the subdiurnal to diurnal (hours to days) timescale, use an enhanced diffusion model to replicate the effects of CO2 concentration depletions from persistent winds, and use a model-measure pairing to effectively explore what is happening in the field. We took continuous measurements of CO2 concentration gradients and meteorological data at a site in the Cape Breton Highlands of Nova Scotia, Canada, to determine the relationship between wind speeds and CO2 levels in snowpacks. We adapted a soil CO2 diffusion model for the soil-snow system and simulated stepwise changes in transport rate over a broad range of plausible synthetic cases. The goal was to mimic the changes we observed in CO2 snowpack concentration to help elucidate the mechanisms (diffusion, advection) responsible for observed variations. On subdiurnal to diurnal timescales with varying winds and constant snow levels, a strong negative relationship between wind speed and CO2 concentration within the snowpack was often identified. Modelling clearly demonstrated that diffusion alone was unable to replicate the high-frequency CO2 fluctuations, but simulations using above-atmospheric snowpack diffusivities (simulating advective transport within the snowpack) reproduced snow CO2 changes of the observed magnitude and speed. This confirmed that wind-induced ventilation contributed to episodic pulsed emissions from the snow surface and to suppressed snowpack concentrations. This study improves our understanding of winter CO2 dynamics to aid in continued quantification of the annual global C cycle and demonstrates a preference for continuous wintertime CO2 flux measurement systems.

  10. Explaining CO2 fluctuations observed in snowpacks

    Directory of Open Access Journals (Sweden)

    L. Graham


    Full Text Available Winter soil carbon dioxide (CO2 respiration is a significant and understudied component of the global carbon (C cycle. Winter soil CO2 fluxes can be surprisingly variable, owing to physical factors such as snowpack properties and wind. This study aimed to quantify the effects of advective transport of CO2 in soil–snow systems on the subdiurnal to diurnal (hours to days timescale, use an enhanced diffusion model to replicate the effects of CO2 concentration depletions from persistent winds, and use a model–measure pairing to effectively explore what is happening in the field. We took continuous measurements of CO2 concentration gradients and meteorological data at a site in the Cape Breton Highlands of Nova Scotia, Canada, to determine the relationship between wind speeds and CO2 levels in snowpacks. We adapted a soil CO2 diffusion model for the soil–snow system and simulated stepwise changes in transport rate over a broad range of plausible synthetic cases. The goal was to mimic the changes we observed in CO2 snowpack concentration to help elucidate the mechanisms (diffusion, advection responsible for observed variations. On subdiurnal to diurnal timescales with varying winds and constant snow levels, a strong negative relationship between wind speed and CO2 concentration within the snowpack was often identified. Modelling clearly demonstrated that diffusion alone was unable to replicate the high-frequency CO2 fluctuations, but simulations using above-atmospheric snowpack diffusivities (simulating advective transport within the snowpack reproduced snow CO2 changes of the observed magnitude and speed. This confirmed that wind-induced ventilation contributed to episodic pulsed emissions from the snow surface and to suppressed snowpack concentrations. This study improves our understanding of winter CO2 dynamics to aid in continued quantification of the annual global C cycle and demonstrates a preference for continuous wintertime CO2 flux

  11. Concentrations of selected contaminants in cabin air of airbus aircrafts. (United States)

    Dechow, M; Sohn, H; Steinhanses, J


    The concentrations of selected air quality parameters in aircraft cabins were investigated including particle numbers in cabin air compared to fresh air and recirculation air, the microbiological contamination and the concentration of volatile organic compounds (VOC). The Airbus types A310 of Swissair and A340 of Lufthansa were used for measurements. The particles were found to be mainly emitted by the passengers, especially by smokers. Depending on recirculation filter efficiency the recirculation air contained a lower or equal amount of particles compared to the fresh air, whereas the amount of bacteria exceeded reported concentrations within other indoor spaces. The detected species were mainly non-pathogenic, with droplet infection over short distances identified as the only health risk. The concentration of volatile organic compounds (VOC) were well below threshold values. Ethanol was identified as the compound with the highest amount in cabin air. Further organics were emitted by the passengers--as metabolic products or by smoking--and on ground as engine exhaust (bad airport air quality). Cleaning agents may be the source of further compounds.

  12. Management of uncertainties on parameters elicited by experts - Applications to sea-level rise and to CO2 storage operations risk assessment (United States)

    Manceau, Jean-Charles; Loschetter, Annick; Rohmer, Jérémy; Le Cozannet, Gonéri; Lary Louis, de; Guénan Thomas, Le; Ken, Hnottavange-Telleen


    In a context of high degree of uncertainty, when very few data are available, experts are commonly requested to provide their opinions on input parameters of risk assessment models. Not only might each expert express a certain degree of uncertainty on his/her own statements, but the set of information collected from the pool of experts introduces an additional level of uncertainty. It is indeed very unlikely that all experts agree on exactly the same data, especially regarding parameters needed for natural risk assessments. In some cases, their opinions may differ only slightly (e.g. the most plausible value for a parameter is similar for different experts, and they only disagree on the level of uncertainties that taint the said value) while on other cases they may express incompatible opinions for a same parameter. Dealing with these different kinds of uncertainties remains a challenge for assessing geological hazards or/and risks. Extra-probabilistic approaches (such as the Dempster-Shafer theory or the possibility theory) have shown to offer promising solutions for representing parameters on which the knowledge is limited. It is the case for instance when the available information prevents an expert from identifying a unique probability law to picture the total uncertainty. Moreover, such approaches are known to be particularly flexible when it comes to aggregating several and potentially conflicting opinions. We therefore propose to discuss the opportunity of applying these new theories for managing the uncertainties on parameters elicited by experts, by a comparison with the application of more classical probability approaches. The discussion is based on two different examples. The first example deals with the estimation of the injected CO2 plume extent in a reservoir in the context of CO2 geological storage. This estimation requires information on the effective porosity of the reservoir, which has been estimated by 14 different experts. The Dempster

  13. Effects of simultaneously elevated temperature and CO2levels on Nicotiana benthamiana and its infection by different positive-sense RNA viruses are cumulative and virus type-specific. (United States)

    Del Toro, Francisco J; Rakhshandehroo, Farshad; Larruy, Beatriz; Aguilar, Emmanuel; Tenllado, Francisco; Canto, Tomás


    We have studied how simultaneously elevated temperature and CO 2 levels [climate change-related conditions (CCC) of 30°C, 970 parts-per-million (ppm) of CO 2 vs. standard conditions (SC) of 25°C, ~ 405ppm CO 2 ] affect physiochemical properties of Nicotiana benthamiana leaves, and also its infection by several positive-sense RNA viruses. In previous works we had studied effects of elevated temperature, CO 2 levels separately. Under CCC, leaves of healthy plants almost doubled their area relative to SC but contained less protein/unit-of-area, similarly to what we had found under conditions of elevated CO 2 alone. CCC also affected the sizes/numbers of different foliar cell types differently. Under CCC, infection outcomes in titers and symptoms were virus type-specific, broadly similar to those observed under elevated temperature alone. Under either condition, infections did not significantly alter the protein content of leaf discs. Therefore, effects of elevated temperature and CO 2 combined on properties of the pathosystems studied were overall cumulative. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Soil Organic Matter Stores and Dynamics in a Chaparral Ecosystem After Eight Years of Exposure to a Gradient of Atmospheric CO2 Concentrations, From pre-Industrial Level to 750 ppm (United States)

    del Galdo, I.; Oechel, W. C.; Cotrufo, F.


    Due to the continuously increasing concentration of atmospheric CO2, it has become a priority to understand if soil organic matter (SOM) will act as a sink or a source of CO2, under future environmental change. Although many studies have addressed the question, a clear answer, in particular on the long term response, is still missing. Here we report the results of an experiment where we quantified the soil C stores and investigated the dynamics of SOM, its aggregation and pool composition, in a Californian chaparral ecosystem, exposed to a gradient of atmospheric CO2 concentrations. In the study site of Sky Oaks (Warner Springs, CA, USA), twelve closed chambers were installed in 1992, and for 8 years they were fumigated with different concentration of CO2, ranging from pre-industrial levels (250 ppm) to 750 ppm CO2, with step increments of 100 ppm. Fossil fuel-derived CO2, depleted in 13C, was used to fumigate the chambers, thus allowed to trace the C input from the vegetation to the soil at all levels of CO2 exposure. In January 2003, soil were sampled from each chamber and shipped to the SUN (Italy). Here, soil samples were separated by wet sieving into different classes of aggregates, namely, macroaggregates (>250μ m), microaggregates (53-250 μ m) and silt&clay (<53 μ m). Within macroaggregates, we isolated three different structural and functional pools: the coarse particulate organic matter (POM), the microaggregates and the occluded silt&clay. Lastly, a density floatation with Sodium Polytungstate allowed the separation of light fraction contained in the microaggregates from the intra and inter-POM. The isotope mixing-model approach was used to quantify the net C input from the vegetation to the soil along the entire gradient of atmospheric CO2 concentrations.

  15. How Accurately Do Maize Crop Models Simulate the Interactions of Atmospheric CO2 Concentration Levels With Limited Water Supply on Water Use and Yield? (United States)

    Durand, Jean-Louis; Delusca, Kenel; Boote, Ken; Lizaso, Jon; Manderscheid, Remy; Weigel, Hans Johachim; Ruane, Alexander Clark; Rosenzweig, Cynthia E.; Jones, Jim; Ahuja, Laj; hide


    This study assesses the ability of 21 crop models to capture the impact of elevated CO2 concentration [CO2] on maize yield and water use as measured in a 2-year Free Air Carbon dioxide Enrichment experiment conducted at the Thunen Institute in Braunschweig, Germany (Manderscheid et al. 2014). Data for ambient [CO2] and irrigated treatments were provided to the 21 models for calibrating plant traits, including weather, soil and management data as well as yield, grain number, above ground biomass, leaf area index, nitrogen concentration in biomass and grain, water use and soil water content. Models differed in their representation of carbon assimilation and evapotranspiration processes. The models reproduced the absence of yield response to elevated [CO2] under well-watered conditions, as well as the impact of water deficit at ambient [CO2], with 50 percent of models within a range of plus/minus 1 Mg ha(exp. -1) around the mean. The bias of the median of the 21 models was less than 1 Mg ha(exp. -1). However under water deficit in one of the two years, the models captured only 30 percent of the exceptionally high [CO2] enhancement on yield observed. Furthermore the ensemble of models was unable to simulate the very low soil water content at anthesis and the increase of soil water and grain number brought about by the elevated [CO2] under dry conditions. Overall, we found models with explicit stomatal control on transpiration tended to perform better. Our results highlight the need for model improvement with respect to simulating transpirational water use and its impact on water status during the kernel-set phase.

  16. Options for CO2 sequestration in Kuwait

    NARCIS (Netherlands)

    Neele, F.; Vandeweijer, V.; Mayyan, H.; Sharma, S.R.; Kamal, D.


    In preparation for future requirements to abate CO2 emission levels, a CO2 storage feasibility study was carried out for the country of Kuwait. At present, no definite plans exist to install capture facilities at the larger emission points in the country; the study presented is one of the first

  17. Elevated CO2 increases tree-level intrinsic water use efficiency: insights from carbon and oxygen isotope analyses in tree rings across three forest FACE sites

    Energy Technology Data Exchange (ETDEWEB)

    Battipaglia, Giovanna [Second University of Naples; Saurer, Matthias [Paul Scherrer Institut, Villigen, Switzerland; Cherubini, Paulo [WSL Swiss Federal Institute for Forest, Snow and Landscape Research; Califapietra, Carlo [University of Tuscia; McCarthy, Heather R [Duke University; Norby, Richard J [ORNL; Cotrufo, M. Francesca [Colorado State University, Fort Collins


    Elevated CO2 increases intrinsic water use efficiency (WUEi) of forests, but the magnitude of this effect and its interaction with climate is still poorly understood. We combined tree ring analysis with isotope measurements at three Free Air CO2 Enrichment (FACE, POP-EUROFACE, in Italy; Duke FACE in North Carolina and ORNL in Tennessee, USA) sites, to cover the entire life of the trees. We used 13C to assess carbon isotope discrimination ( 13C ci/ca) and changes in WUEi, while direct CO2 effects on stomatal conductance were explored using 18O as a proxy. Across all the sites, elevated CO2 increased 13C-derived WUEi on average by 73% for Liquidambar styraciflua, 77% for Pinus taeda and 75% for Populus sp., but through different ecophysiological mechanisms. Our findings provide a robust means of predicting WUEi responses from a variety of tree species exposed to variable environmental conditions over time, and species-specific relationships that can help modeling elevated CO2 and climate impacts on forest productivity, carbon and water balances.

  18. How a 10-day heatwave impacts barley grain yield when superimposed onto future levels of temperature and CO2 as single and combined factors

    DEFF Research Database (Denmark)

    Heinz Ingvordsen, Cathrine; Lyngkjær, Michael F.; Peltonen-Sainio, Pirjo


    scenarios, 22 barley accessions were cultivated with elevated temperature (+5 °C) and CO2 (700 ppm) as single factors and in combination. The control treatment mimicked ambient Scandinavian early summer conditions (19/12 °C, day/night; 400 ppm CO2). Around flowering a 10-day heatwave of 33/28 °C (day....../night) was superimposed to all treatments. The lowest average grain yield was observed when the heatwave was superimposed onto the combined elevated temperature and CO2 treatment. Here the yield decreased by 42% compared to no heatwave and 52% compared to ambient conditions. When the heatwave was superimposed onto...... ambient conditions the average grain yield decreased by 37% compared to no heatwave. There was no significant difference between the relative grain yield decrease caused by the heatwave in the ambient and future climate scenarios. In contrast, the vegetative aboveground biomass increased upon heatwave...

  19. Effect of low-level CO2 laser radiation on the inhibition of smooth-surface caries (in-vitro study) (United States)

    Boran, Thomas L.; Zakariasen, Kenneth L.


    The application of lasers in dentistry is not a new concept. Lasers have been used in various areas of dental research over the last two decades. However, recent technological development and research findings indicate that widespread clinical application of lasers will occur shortly. Many of the early studies discovered that high levels of laser radiation were detrimental to the vitality of the dental pulp. This has led researchers to investigate whether low level laser radiation would have positive effects on the various components of the dental hard tissues. This study examined the anti-carious effect of low level C02 laser radiation on smooth surface enamel. Fifty extracted third molars were selected and covered in acid resistant varnish except for two windows on the buccal surface just above the CEJ. The windows measured 1.5 x 1.5 mm with one window designated as the control and the other experimental. In each experiment the Pfizer Model 10-C laser system was used. The teeth were divided into two groups. In group I, the experimental window was lased with 1.2 watts at 0.1 seconds with a 1.5 mm focal spot. In Group II, the experimental window was lased with 2.4 watts at 0. 1 seconds with a 1.5 mm focal spot. Both groups were exposed for 12 days in a demineralizing solution (2.2 mM Ca, 2.2 mM P0 ,50 mM acetic acid, 5 ppmF-@ constant pH -4.3). The resulting lesions were sectioned to approximately 80 im thickness using a hard tissue microtome. Each section was examined by taking polarized light photomicrographs after imbibition in H20 medium. Results of the study suggested a significant reduction in the lesion size in both experiments, all exposures being within the biological safe zone of temperature elevation to the surrounding vital tissues, e.g. the dental pulp and periodontal tissue. Further research will be required to determine the level of CO2 laser radiation which will provide the maximum anti-carious effect.

  20. Peak levels of endogenous cytokinins after decapitation in leaves of leguminous plants: increase of protein and chlorophyll contents and photosynthetic 14CO2 fixation

    International Nuclear Information System (INIS)

    Pozsar, B.I.


    The side-effects of endogenous cytokinins were examined in leguminous plants (beans, alfalfa). Two weeks after decapitation the cytokinin-content of the leaves increased approx. 8-fold. Parallel to this, the total N-content increased by 30%, the protein N-content by 70%, the chlorophyll-content by 40% and the photosynthetic 14 CO 2 fixation by 100%. Thus, in addition to the mitotic activity, the protein-synthesis and photosynthetic CO 2 fixation are also enhanced by endogenous cytokinins. (L.E.)

  1. Expression profiling indicating low selenium-sensitive microRNA levels linked to cell cycle and cell stress response pathways in the CaCo-2 cell line. (United States)

    McCann, Mark J; Rotjanapun, Kunjana; Hesketh, John E; Roy, Nicole C


    Se is an essential micronutrient for human health, and fluctuations in Se levels and the potential cellular dysfunction associated with it may increase the risk for disease. Although Se has been shown to influence several biological pathways important in health, little is known about the effect of Se on the expression of microRNA (miRNA) molecules regulating these pathways. To explore the potential role of Se-sensitive miRNA in regulating pathways linked with colon cancer, we profiled the expression of 800 miRNA in the CaCo-2 human adenocarcinoma cell line in response to a low-Se (72 h at <40 nm) environment using nCounter direct quantification. These data were then examined using a range of in silico databases to identify experimentally validated miRNA-mRNA interactions and the biological pathways involved. We identified ten Se-sensitive miRNA (hsa-miR-93-5p, hsa-miR-106a-5p, hsa-miR-205-5p, hsa-miR-200c-3p, hsa-miR-99b-5p, hsa-miR-302d-3p, hsa-miR-373-3p, hsa-miR-483-3p, hsa-miR-512-5p and hsa-miR-4454), which regulate 3588 mRNA in key pathways such as the cell cycle, the cellular response to stress, and the canonical Wnt/β-catenin, p53 and ERK/MAPK signalling pathways. Our data show that the effects of low Se on biological pathways may, in part, be due to these ten Se-sensitive miRNA. Dysregulation of the cell cycle and of the stress response pathways due to low Se may influence key genes involved in carcinogenesis.

  2. Physiological, biochemical, and genome-wide transcriptional analysis reveals that elevated CO2 mitigates the impact of combined heat wave and drought stress in Arabidopsis thaliana at multiple organizational levels. (United States)

    Zinta, Gaurav; AbdElgawad, Hamada; Domagalska, Malgorzata A; Vergauwen, Lucia; Knapen, Dries; Nijs, Ivan; Janssens, Ivan A; Beemster, Gerrit T S; Asard, Han


    Climate changes increasingly threaten plant growth and productivity. Such changes are complex and involve multiple environmental factors, including rising CO2 levels and climate extreme events. As the molecular and physiological mechanisms underlying plant responses to realistic future climate extreme conditions are still poorly understood, a multiple organizational level analysis (i.e. eco-physiological, biochemical, and transcriptional) was performed, using Arabidopsis exposed to incremental heat wave and water deficit under ambient and elevated CO2 . The climate extreme resulted in biomass reduction, photosynthesis inhibition, and considerable increases in stress parameters. Photosynthesis was a major target as demonstrated at the physiological and transcriptional levels. In contrast, the climate extreme treatment induced a protective effect on oxidative membrane damage, most likely as a result of strongly increased lipophilic antioxidants and membrane-protecting enzymes. Elevated CO2 significantly mitigated the negative impact of a combined heat and drought, as apparent in biomass reduction, photosynthesis inhibition, chlorophyll fluorescence decline, H2 O2 production, and protein oxidation. Analysis of enzymatic and molecular antioxidants revealed that the stress-mitigating CO2 effect operates through up-regulation of antioxidant defense metabolism, as well as by reduced photorespiration resulting in lowered oxidative pressure. Therefore, exposure to future climate extreme episodes will negatively impact plant growth and production, but elevated CO2 is likely to mitigate this effect. © 2014 John Wiley & Sons Ltd.

  3. Combined effects of CO2 enrichment, changes in diurnal light level and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers (United States)

    Potato plants (Solanum tuberosum L. cv Kennebec) were grown in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers. Drought treatments were imposed at post-tuber initiation stage to assess water stress effects on leaf metabolites, and interactions with enriched CO2 concentrati...

  4. Intermediate-scale community-level flux of CO2 and CH4 in a Minnesota peatland: putting the SPRUCE project in a global context (United States)

    P. J. Hanson; A. L. Gill; X. Xu; J. R. Phillips; D. J. Weston; Randy Kolka; J. S. Riggs; L. A. Hook


    Peatland measurements of CO2 and CH4 flux were obtained at scales appropriate to the in situ biological community below the tree layer to demonstrate representativeness of the spruce and peatland responses under climatic and environmental change (SPRUCE) experiment. Surface flux measurements were made using dual open-path...

  5. Ikaite crystals in melting sea ice - implications for pCO(2) and pH levels in Arctic surface waters

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Glud, Ronnie N.; Lennert, Kunuk


    A major issue of Arctic marine science is to understand whether the Arctic Ocean is, or will be, a source or sink for air-sea CO2 exchange. This has been complicated by the recent discoveries of ikaite (a polymorph of CaCO3 center dot 6H(2)O) in Arctic and Antarctic sea ice, which indicate that m...

  6. Ikaite crystals in melting sea ice - implications for pCO(2) and pH levels in Arctic surface waters

    DEFF Research Database (Denmark)

    Rysgaard, Søren; Glud, Ronnie N.; Lennert, Kunuk


    A major issue of Arctic marine science is to understand whether the Arctic Ocean is, or will be, a source or sink for air-sea CO2 exchange. This has been complicated by the recent discoveries of ikaite (a polymorph of CaCO3 center dot 6H(2)O) in Arctic and Antarctic sea ice, which indicate......, melt reduced the ice floe thickness by 0.2m per week and resulted in an estimated 3.8 ppm decrease of pCO(2) in the ocean surface mixed layer. This corresponds to an air-sea CO2 uptake of 10.6 mmol m(-2) sea ice d(-1) or to 3.3 ton km(-2) ice floe week(-1). This is markedly higher than the estimated...... that multiple chemical transformations occur in sea ice with a possible effect on CO2 and pH conditions in surface waters. Here, we report on biogeochemical conditions, microscopic examinations and x-ray diffraction analysis of single crystals from a melting 1.7 km(2) (0.5-1m thick) drifting ice floe...


    Climate change(elevated atmospheric CO-2,and altered air temperatures,precipitation amounts and seasonal patterns)may affect ecosystem processes by altering carbon allocation in plants,and carbon flux from plants to soil.Mycorrhizal fungi,as carbon sinks, are among the first soil...

  8. Nepenthes pitchers are CO2-enriched cavities, emit CO2to attract preys. (United States)

    Baby, Sabulal; Johnson, Anil John; Zachariah, Elavinamannil Jacob; Hussain, Abdul Azeez


    Carnivorous plants of the genus Nepenthes supplement their nutrient deficiency by capturing arthropods or by mutualistic interactions, through their leaf-evolved biological traps (pitchers). Though there are numerous studies on these traps, mostly on their prey capture mechanisms, the gas composition inside them remains unknown. Here we show that, Nepenthes unopened pitchers are CO 2 -enriched 'cavities', when open they emit CO 2 , and the CO 2 gradient around open pitchers acts as a cue attracting preys towards them. CO 2 contents in near mature, unopened Nepenthes pitchers were in the range 2500-5000 ppm. Gas collected from inside open N. khasiana pitchers showed CO 2 at 476.75 ± 59.83 ppm. CO 2 -enriched air-streaming through N. khasiana pitchers (at 619.83 ± 4.53 ppm) attracted (captured) substantially higher number of aerial preys compared to air-streamed pitchers (CO 2 at 412.76 ± 4.51 ppm). High levels of CO 2 dissolved in acidic Nepenthes pitcher fluids were also detected. We demonstrate respiration as the source of elevated CO 2 within Nepenthes pitchers. Most unique features of Nepenthes pitchers, viz., high growth rate, enhanced carbohydrate levels, declined protein levels, low photosynthetic capacity, high respiration rate and evolved stomata, are influenced by the CO 2 -enriched environment within them.

  9. Five-years of microenvironment data along an urban-rural transect; temperature and CO2 concentrations in urban area at levels expected globally with climate change.

    Energy Technology Data Exchange (ETDEWEB)

    George, Kate; Ziska, Lewis H; Bunce, James A; Quebedeaux, Bruno


    The heat island effect and the high use of fossil fuels in large city centers is well documented, but by how much fossil fuel consumption is elevating atmospheric CO2 concentrations and whether elevations in both atmospheric CO2 and air temperature are consistent from year to year are less well known. Our aim was to record atmospheric CO2 concentrations, air temperature and other environmental variables in an urban area and compare it to suburban and rural sites to see if urban sites are experiencing climates expected globally in the future with climate change. A transect was established from Baltimore city center (Urban site), to the outer suburbs of Baltimore (suburban site) and out to an organic farm (rural site). At each site a weather station was set-up to monitor environmental variables annually for five years. Atmospheric CO2 was significantly increased on average by 66 ppm from the rural to the urban site over the five years of the study. Air temperature was significantly higher at the urban site (14.8 oC) compared to the suburban (13.6 oC) and rural (12.7 oC) sites. Relative humidity was not different between sites but vapor pressure deficit (VPD) was significantly higher at the urban site compared to the suburban and rural sites. During wet years relative humidity was significantly increased and VPD significantly reduced. Increased nitrogen deposition at the rural site (2.1 % compared to 1.8 and 1.2 % at the suburban and urban sites) was small enough not to affect soil nitrogen content. Dense urban areas with large populations and high vehicular traffic have significantly different microclimates compared to outlying suburban and rural areas. The increases in atmospheric CO2 and air temperature are similar to changes predicted in the short term with global climate change, therefore providing an environment suitable for studying future effects of climate change on terrestrial ecosystems.

  10. CO2 Absorbing Capacity of MEA

    Directory of Open Access Journals (Sweden)

    José I. Huertas


    Full Text Available We describe the use of a gas bubbler apparatus in which the gas phase is bubbled into a fixed amount of absorbent under standard conditions as a uniform procedure for determining the absorption capacity of solvents. The method was systematically applied to determine the CO2 absorbing capacity of MEA (Ac at several aqueous MEA (β and gas-phase CO2 concentrations. Ac approached the nominal CO2 absorbing capacity of MEA (720 g CO2/kg MEA at very low β levels, increasing from 447.9±18.1 to 581.3±32.3 g CO2/kg MEA as β was reduced from 30 to 2.5% (w/w. Ac did not depend on the CO2 concentration in the inlet gas stream as long as the gas stream did not include other amine sensitive components. During the bubbling tests the outlet CO2 concentration profiles exhibited a sigmoidal shape that could be described by an exponential equation characterized by an efficiency factor (a and a form factor (n. Statistical analysis based on correlation analysis indicated that in all cases the experimental data fit the equation well when a was 6.1±0.35 and n was 2.5±0.12. The results of these experiments may be used to optimize scrubber designs for CO2 sequestration from fossil fuel derived flue gases.

  11. Policy Options for Reducing CO2 Emissions

    National Research Council Canada - National Science Library

    Bogusz, Christine; Howlett, Christian


    .... Reducing that risk would require restraining the growth of CO2 emissions and ultimately limiting those emissions to a level that would stabilize atmospheric concentrations which would involve costs...

  12. Brine migration resulting from CO2 injection into saline aquifers – An approach to risk estimation including various levels of uncertainty

    DEFF Research Database (Denmark)

    Walter, Lena; Binning, Philip John; Oladyshkin, Sergey


    for large-scale 3D models including complex physics. Therefore, we apply a model reduction based on arbitrary polynomial chaos expansion combined with probabilistic collocation method. It is shown that, dependent on data availability, both types of uncertainty can be equally significant. The presented study...... provides estimates of the risk of brine discharge into freshwater aquifers due to CO2 injection into geological formations and resultant salt concentrations in the overlying drinking water aquifers....

  13. Evasion of CO2 injected into the ocean in the context of CO2 stabilization

    International Nuclear Information System (INIS)

    Kheshgi, Haroon S.


    The eventual evasion of injected CO 2 to the atmosphere is one consideration when assessing deep-sea disposal of CO 2 as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO 2 emissions, including illustrative cases leading to stabilization of CO 2 concentration at various levels. Modeled residence time for CO 2 injected into the deep ocean exceeds the 100-year time-scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO 2 concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO 2 emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO 2 concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO 2 concentration, with less effect on concentration later on in time

  14. Ecophysiology at SPRUCE: Impacts of whole ecosystem warming and elevated CO2 on leaf-level photosynthesis and respiration of two ericaceous shrubs in a boreal peatland (United States)

    Ward, E. J.; Dusenge, M. E.; Warren, J.; Murphy, B. K.; Way, D.; King, A. W.; McLennan, D.; Montgomery, R.; Stefanski, A.; Reich, P. B.; Cruz Aguilar, M.; Wullschleger, S.; Bermudez Villanueva, R.; Hanson, P. J.


    The Spruce and Peatland Responses Under Changing Environments (SPRUCE) project is a large-scale, long-term experiment investigating the effects of warming and elevated CO2 on an ombrotrophic bog in Minnesota, USA. SPRUCE uses 10 large (12.8-m diameter) enclosures to increase air and soil temperatures to a range of targets (+0 °C, +2.25 °C, +4.5 °C, +6.75 °C, +9 °C) under both ambient and elevated (+500 ppm) CO2 concentrations. Whole-ecosystem-warming treatments began in August 2015 and elevated CO2 treatments began in June 2016. This talk will address the photosynthetic and respiratory responses of vascular plants to the treatments as measured with a variety of in-situ and ex-situ measurements conducted throughout the 2016 and 2017 growing seasons. We will focus on the responses of two dominant ericaceous shrubs (Rhododendron groenlandicum and Chamaedaphne calyculata), which account for more 80% of the understory biomass of this open-canopy forest. Such physiological changes are not only leading indicators of changes in plant growth and community structure, but are crucial to understanding carbon cycling of raised bogs and representing boreal peatlands in global dynamic vegetation models. Pre-treatment data collected at this site indicate that the physiologically active season typically begins in late May and extends into the fall until freezing nighttime temperatures are consistently reached, typically in October. Post-treatment measurements made during seasonal transitions indicate a longer active physiological season in warmer treatments. Results from 2016 measurements show some degree of thermal acclimation of photosynthesis in R. groenlandicum and of respiration in both species in the early growing season, but not late season. Late season measurements show a down-regulation of photosynthesis in both shrub species grown under elevated CO2. Taken as a whole, these results indicate complex interactions between phenological changes and treatment effects on

  15. Potential and economics of CO2 sequestration

    International Nuclear Information System (INIS)

    Jean-Baptiste, Ph.; Ciais, Ph.; Orr, J.


    Increasing atmospheric level of greenhouse gases are causing global warming and putting at risk the global climate system. The main anthropogenic greenhouse gas is CO 2 . Some techniques could be used to reduced CO 2 emission and stabilize atmospheric CO 2 concentration, including i) energy savings and energy efficiency, ii) switch to lower carbon content fuels (natural gas) and use energy sources with zero CO 2 emissions such as renewable or nuclear energy, iii) capture and store CO 2 from fossil fuels combustion, and enhance the natural sinks for CO 2 (forests, soils, ocean...). The purpose of this report is to provide an overview of the technology and cost for capture and storage of CO 2 and to review the various options for CO 2 sequestration by enhancing natural carbon sinks. Some of the factors which will influence application, including environmental impact, cost and efficiency, are discussed. Capturing CO 2 and storing it in underground geological reservoirs appears as the best environmentally acceptable option. It can be done with existing technology, however, substantial R and D is needed to improve available technology and to lower the cost. Applicable to large CO 2 emitting industrial facilities such as power plants, cement factories, steel industry, etc., which amount to about 30% of the global anthropic CO 2 emission, it represents a valuable tool in the baffle against global warming. About 50% of the anthropic CO 2 is being naturally absorbed by the biosphere and the ocean. The 'natural assistance' provided by these two large carbon reservoirs to the mitigation of climate change is substantial. The existing natural sinks could be enhanced by deliberate action. Given the known and likely environmental consequences, which could be very damaging indeed, enhancing ocean sinks does not appears as a satisfactory option. In contrast, the promotion of land sinks through demonstrated carbon-storing approach to agriculture, forests and land management could

  16. Carbonation and CO2 uptake of concrete

    International Nuclear Information System (INIS)

    Yang, Keun-Hyeok; Seo, Eun-A; Tae, Sung-Ho


    This study developed a reliable procedure to assess the carbon dioxide (CO 2 ) uptake of concrete by carbonation during the service life of a structure and by the recycling of concrete after demolition. To generalize the amount of absorbable CO 2 per unit volume of concrete, the molar concentration of carbonatable constituents in hardened cement paste was simplified as a function of the unit content of cement, and the degree of hydration of the cement paste was formulated as a function of the water-to-cement ratio. The contribution of the relative humidity, type of finishing material for the concrete surface, and the substitution level of supplementary cementitious materials to the CO 2 diffusion coefficient in concrete was reflected using various correction factors. The following parameters varying with the recycling scenario were also considered: the carbonatable surface area of concrete crusher-runs and underground phenomena of the decreased CO 2 diffusion coefficient and increased CO 2 concentration. Based on the developed procedure, a case study was conducted for an apartment building with a principal wall system and an office building with a Rahmen system, with the aim of examining the CO 2 uptake of each structural element under different exposure environments during the service life and recycling of the building. As input data necessary for the case study, data collected from actual surveys conducted in 2012 in South Korea were used, which included data on the surrounding environments, lifecycle inventory database, life expectancy of structures, and recycling activity scenario. Ultimately, the CO 2 uptake of concrete during a 100-year lifecycle (life expectancy of 40 years and recycling span of 60 years) was estimated to be 15.5%–17% of the CO 2 emissions from concrete production, which roughly corresponds to 18%–21% of the CO 2 emissions from the production of ordinary Portland cement. - Highlights: • CO 2 uptake assessment approach owing to the

  17. Combined effects of CO2 enrichment, diurnal light levels and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers. (United States)

    Barnaby, Jinyoung Y; Fleisher, David; Reddy, Vangimalla; Sicher, Richard


    Experiments were conducted in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers using plants grown in pots. Drought treatments were imposed on potato plants (Solanum tuberosum cv. Kennebec) beginning 10 days after tuber initiation. A total of 23 out of 37 foliar metabolites were affected by drought when measured 11 days after initiating water stress treatments. Compounds that accumulated in response to drought were hexoses, polyols, branched chain amino acids (BCAAs) and aromatic amino acids, such as proline. Conversely, leaf starch, alanine, aspartate and several organic acids involved in respiratory metabolism decreased with drought. Depending upon harvest date, a maximum of 12 and 17 foliar metabolites also responded to either CO2 enrichment or diurnal treatments, respectively. In addition, about 20% of the measured metabolites in potato leaflets were simultaneously affected by drought, CO2 enrichment and diurnal factors combined. This group contained BCAAs, hexoses, leaf starch and malate. Polyols and proline accumulated in response to water stress but did not vary diurnally. Water stress also amplified diurnal variations of hexoses and starch in comparison to control samples. Consequently, specific drought responsive metabolites in potato leaflets were dramatically affected by daily changes of photosynthetic carbon metabolism. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  18. Impact of elevated levels of CO2 on animal mediated ecosystem function: the modification of sediment nutrient fluxes by burrowing urchins. (United States)

    Widdicombe, S; Beesley, A; Berge, J A; Dashfield, S L; McNeill, C L; Needham, H R; Øxnevad, S


    A mesocosm experiment was conducted to quantify the relationships between the presence and body size of two burrowing heart urchins (Brissopsis lyrifera and Echinocardium cordatum) and rates of sediment nutrient flux. Furthermore, the impact of seawater acidification on these relationships was determined during this 40-day exposure experiment. Using carbon dioxide (CO2) gas, seawater was acidified to pHNBS 7.6, 7.2 or 6.8. Control treatments were maintained in natural seawater (pH≈8.0). Under normocapnic conditions, burrowing urchins were seen to reduce the sediment uptake of nitrite or nitrate whilst enhancing the release of silicate and phosphate. In acidified (hypercapnic) treatments, the biological control of biogeochemical cycles by urchins was significantly affected, probably through the combined impacts of high CO2 on nitrifying bacteria, benthic algae and urchin behaviour. This study highlights the importance of considering biological interactions when predicting the consequences of seawater acidification on ecosystem function. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. CO2 Emissions from Fuel Combustion 2011: Highlights

    Energy Technology Data Exchange (ETDEWEB)



    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Durban, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: - estimates of CO2 emissions by country from 1971 to 2009; - selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; - CO2 emissions from international marine and aviation bunkers, and other relevant information. These estimates have been calculated using the IEA energy databases and the default methods and emission factors from the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories.

  20. CO(2) Inhibits Respiration in Leaves of Rumex crispus L. (United States)

    Amthor, J S; Koch, G W; Bloom, A J


    Curly dock (Rumex crispus L.) was grown from seed in a glasshouse at an ambient CO(2) partial pressure of about 35 pascals. Apparent respiration rate (CO(2) efflux in the dark) of expanded leaves was then measured at ambient CO(2) partial pressure of 5 to 95 pascals. Calculated intercellular CO(2) partial pressure was proportional to ambient CO(2) partial pressure in these short-term experiments. The CO(2) level strongly affected apparent respiration rate: a doubling of the partial pressure of CO(2) typically inhibited respiration by 25 to 30%, whereas a decrease in CO(2) elicited a corresponding increase in respiration. These responses were readily reversible. A flexible, sensitive regulatory interaction between CO(2) (a byproduct of respiration) and some component(s) of heterotrophic metabolism is indicated.

  1. CO2 Emissions from Fuel Combustion - 2012 Highlights

    Energy Technology Data Exchange (ETDEWEB)



    How much CO2 are countries emitting? Where is it coming from? In the lead-up to the UN climate negotiations in Doha, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process the IEA is making available for free download the 'Highlights' version of CO2 Emissions from Fuel Combustion. This annual publication contains: estimates of CO2 emissions by country from 1971 to 2010; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; and CO2 emissions from international marine and aviation bunkers, and other relevant information.

  2. India Co2 Emissions (United States)

    Sharan, S.; Diffenbaugh, N. S.


    created a balance in between the “developed” and developing countries. If India was producing the same amounts of emissions per capita as the it would have a total of 20 billion metric tons of CO2 emissions annually.

  3. Inter-seasonal and spatial distribution of ground-level greenhouse gases (CO2, CH4, N2O) over Nagpur in India and their management roadmap. (United States)

    Majumdar, Deepanjan; Rao, Padma; Maske, Nilam


    Ground-level concentrations of carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) were monitored over three seasons, i.e., post-monsoon (September-October), winter (January-February), and summer (May-June) for 1 year during 2013-2014 in Nagpur City in India. The selected gases had moderate to high variation both spatially (residential, commercial, traffic intersections, residential cum commercial sites) and temporally (at 7:00, 13:00, 18:00, and 23:00 hours in all three seasons). Concentrations of gases were randomly distributed diurnally over city in all seasons, and there was no specific increasing or decreasing trend with time in a day. Average CO 2 and N 2 O concentrations in winter were higher over post-monsoon and summer while CH 4 had highest average concentration in summer. Observed concentrations of CO 2 were predominantly above global average of 400 ppmv while N 2 O and CH 4 concentrations frequently dropped down below global average of 327 ppbv and 1.8 ppmv, respectively. Two-tailed Student's t test indicated that post-monsoon CO 2 concentrations were statistically different from summer but not so from winter, while difference between summer and winter concentrations was statistically significant (P gases calculated for three seasons together were higher in commercial areas. Environmental management priorities vis a vis greenhouse gas emissions in the city are also discussed.

  4. Advanced Supported Liquid Membranes for Carbon Dioxide Control in Cabin Applications (United States)

    Wickham, David T.; Gleason, Kevin J.; Engel, Jeffrey R.; Chullen, Cinda


    The development of new, robust, life support systems is critical to NASA's continued progress in space exploration. One vital function is maintaining the carbon dioxide (CO2) concentration in the cabin at levels that do not impair the health or performance of the crew. The carbon dioxide removal assembly (CDRA) is the current CO2 control technology on-board the International Space Station (ISS). Although the CDRA has met the needs of the ISS to date, the repeated cycling of the molecular sieve sorbent causes it to break down into small particles that clog filters or generate dust in the cabin. This reduces reliability and increases maintenance requirements. Another approach that has potential advantages over the current system is a membrane that separates CO2 from air. In this approach, cabin air contacts one side of the membrane while other side of the membrane is maintained at low pressure to create a driving force for CO2 transport across the membrane. In this application, the primary power requirement is for the pump that creates the low pressure and then pumps the CO2 to the oxygen recovery system. For such a membrane to be practical, it must have high CO2 permeation rate and excellent selectivity for CO2 over air. Unfortunately, conventional gas separation membranes do not have adequate CO2 permeability and selectivity to meet the needs of this application. However, the required performance could be obtained with a supported liquid membrane (SLM), which consists of a microporous material filled with a liquid that selectively reacts with CO2 over air. In a recently completed Phase II SBIR project, Reaction Systems, Inc. fabricated an SLM that is very close to meeting permeability and selectivity objectives for use in the Portable Life Support System (PLSS). This paper describes work carried out to evaluate its potential for use in the cabin.

  5. CO2 as a refrigerant

    CERN Document Server


    A first edition, the IIR guide “CO2 as a Refrigerant” highlights the application of carbon dioxide in supermarkets, industrial freezers, refrigerated transport, and cold stores as well as ice rinks, chillers, air conditioning systems, data centers and heat pumps. This guide is for design and development engineers needing instruction and inspiration as well as non-technical experts seeking background information on a specific topic. Written by Dr A.B. Pearson, a well-known expert in the field who has considerable experience in the use of CO2 as a refrigerant. Main topics: Thermophysical properties of CO2 – Exposure to CO2, safety precautions – CO2 Plant Design – CO2 applications – Future prospects – Standards and regulations – Bibliography.

  6. CO2 interaction with geomaterials.

    Energy Technology Data Exchange (ETDEWEB)

    Guthrie, George D. (U.S. Department of Energy, Pittsburgh, PA); Al-Saidi, Wissam A. (University of Pittsburgh, Pittsburgh, PA); Jordan, Kenneth D. (University of Pittsburgh, Pittsburgh, PA); Voora, Vamsee, K. (University of Pittsburgh, Pittsburgh, PA); Romanov, Vyacheslav N. (U.S. Department of Energy, Pittsburgh, PA); Lopano, Christina L (U.S. Department of Energy, Pittsburgh, PA); Myshakin, Eugene M. (URS Corporation, Pittsburgh, PA); Hur, Tae Bong (University of Pittsburgh, Pittsburgh, PA); Warzinski, Robert P. (U.S. Department of Energy, Pittsburgh, PA); Lynn, Ronald J. (URS Corporation, Pittsburgh, PA); Howard, Bret H. (U.S. Department of Energy, Pittsburgh, PA); Cygan, Randall Timothy


    This work compares the sorption and swelling processes associated with CO2-coal and CO2-clay interactions. We investigated the mechanisms of interaction related to CO2 adsortion in micropores, intercalation into sub-micropores, dissolution in solid matrix, the role of water, and the associated changes in reservoir permeability, for applications in CO2 sequestration and enhanced coal bed methane recovery. The structural changes caused by CO2 have been investigated. A high-pressure micro-dilatometer was equipped to investigate the effect of CO2 pressure on the thermoplastic properties of coal. Using an identical dilatometer, Rashid Khan (1985) performed experiments with CO2 that revealed a dramatic reduction in the softening temperature of coal when exposed to high-pressure CO2. A set of experiments was designed for -20+45-mesh samples of Argonne Premium Pocahontas No.3 coal, which is similar in proximate and ultimate analysis to the Lower Kittanning seam coal that Khan used in his experiments. No dramatic decrease in coal softening temperature has been observed in high-pressure CO2 that would corroborate the prior work of Khan. Thus, conventional polymer (or 'geopolymer') theories may not be directly applicable to CO2 interaction with coals. Clays are similar to coals in that they represent abundant geomaterials with well-developed microporous structure. We evaluated the CO2 sequestration potential of clays relative to coals and investigated the factors that affect the sorption capacity, rates, and permanence of CO2 trapping. For the geomaterials comparison studies, we used source clay samples from The Clay Minerals Society. Preliminary results showed that expandable clays have CO2 sorption capacities comparable to those of coal. We analyzed sorption isotherms, XRD, DRIFTS (infrared reflectance spectra at non-ambient conditions), and TGA-MS (thermal gravimetric analysis) data to compare the effects of various factors on CO2 trapping. In montmorillonite, CO

  7. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available BACKGROUND: CO(2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. METHODOLOGY/PRINCIPAL FINDINGS: We measured CO(2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO(2 efflux. CO(2 efflux from soils declines from time of clearing from ∼10,600 tonnes km(-2 year(-1 in the first year to 3000 tonnes km(2 year(-1 after 20 years since clearing. Disturbing peat leads to short term increases in CO(2 efflux (27 umol m(-2 s(-1, but this had returned to baseline levels within 2 days. CONCLUSIONS/SIGNIFICANCE: Deforesting mangroves that grow on peat soils results in CO(2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks.

  8. Convergent Cenozoic CO2 history (United States)

    Royer, D. L.; Beerling, D. J.


    The quality and quantity of Cenozoic CO2 records have increased significantly in the last decade. Gains in quality have come primarily from a fuller accounting of confounding factors; examples include soil respiration rates in the pedogenic carbonate method, alkalinity and seawater δ11B in the boron method, and cell size in the alkenone phytoplankton method. Previously, variability across Cenozoic CO2 estimates in a given time period sometimes exceeded an order of magnitude, but through these improvements variability has been reduced to a factor of two or less. Further improvements in the record can probably be facilitated by more robust quantification of statistical error, generation of CO2 estimates at single locations from multiple methods, and cross-calibration with Pleistocene ice-core CO2 records (Beerling & Royer, 2011, Nature Geoscience 4: 418-420). An improved Cenozoic CO2 record offers opportunities for better understanding Earth system processes. We provide one example related to climate sensitivity. We find a significant relationship between CO2 radiative forcing and global temperature during the Cenozoic, even after accounting for forcings related to solar evolution and paleogeographic changes. Although the calculations are based on simple assumptions and should be taken as provisional, the mean Cenozoic climate sensitivity (3 °C or higher per CO2 doubling) is similar to or higher than calculations for the present-day (~3 °C per CO2 doubling).

  9. 14CO2 in breath

    International Nuclear Information System (INIS)

    Rabinowitz, J.L.; Lopez-Majano, V.


    The diagnosis of metabolic disorders can be made by detecting 14 CO 2 in the breath. This is possible because 14 CO 2 can label any organic compound without any deteriorations in the nature of the compound. This type of analysis is dependable, noninvasive and simple to perform with a scintillation counter. (orig.)

  10. The sequestration of CO2

    International Nuclear Information System (INIS)

    Le Thiez, P.


    The reduction of greenhouse gas emissions, especially CO 2 , represents a major technological and societal challenge in the fight against climate change. Among the measures likely to reduce anthropic CO 2 emissions, capture and geological storage holds out promise for the future. (author)

  11. Exercise carbon dioxide (CO2) retention with inhaled CO2 and breathing resistance. (United States)

    Shykoff, Barbara E; Warkander, Dan E


    Combined effects on respiratory minute ventilation (VE)--and thus, on end-tidal carbon dioxide partial pressure (P(ET)CO2)--of breathing resistance and elevated inspired carbon dioxide (CO2) had not been determined during heavy exercise. In this Institutional Review Board-approved, dry, sea-level study, 12 subjects in each of three phases exercised to exhaustion at 85% peak oxygen uptake while V(E) and P(ET)CO2 were measured. Participants inhaled 0%, 1%, 2% or 3% CO2 in air, or 0% or 2% CO2 in oxygen, with or without breathing resistance, mimicking the U.S. Navy's MK 16 rebreather underwater breathing apparatus (UBA). Compared to air baseline (0% inspired CO2 in air without resistance): (1) Oxygen decreased baseline V(E) (p carbon dioxide partial pressure and respiratory effort. Because elevated CO2 may not increase V(E) if breathing resistance and VE are high, rebreather UBA safety requires very low inspired CO2.

  12. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  13. CO2 Sequestration short course

    Energy Technology Data Exchange (ETDEWEB)

    DePaolo, Donald J. [Lawrence Berkeley National Laboratory; Cole, David R [The Ohio State University; Navrotsky, Alexandra [University of California-Davis; Bourg, Ian C [Lawrence Berkeley National Laboratory


    Given the public’s interest and concern over the impact of atmospheric greenhouse gases (GHGs) on global warming and related climate change patterns, the course is a timely discussion of the underlying geochemical and mineralogical processes associated with gas-water-mineral-interactions encountered during geological sequestration of CO2. The geochemical and mineralogical processes encountered in the subsurface during storage of CO2 will play an important role in facilitating the isolation of anthropogenic CO2 in the subsurface for thousands of years, thus moderating rapid increases in concentrations of atmospheric CO2 and mitigating global warming. Successful implementation of a variety of geological sequestration scenarios will be dependent on our ability to accurately predict, monitor and verify the behavior of CO2 in the subsurface. The course was proposed to and accepted by the Mineralogical Society of America (MSA) and The Geochemical Society (GS).

  14. Ventilation in Sewers Quantified by Measurements of CO2

    DEFF Research Database (Denmark)

    Fuglsang, Emil Dietz; Vollertsen, Jes; Nielsen, Asbjørn Haaning


    occurring compound CO2. Most often Danish wastewater is supersaturated with CO2 and hence a potential for stripping is present. A novel model was built based on the kinetics behind the stripping process. It was applied to simulate ventilation rates from field measurements of wastewater temperature, p......H, alkalinity and sewer-air CO2 concentrations. An intercepting sewer was studied and an average sewer-air retention time of approximately 1.5-2.5 hours was found at CO2 levels around 4-6 times the natural background. Also an upstream sub-catchment was studied. In this part of the sewer system the level of CO2...

  15. CO2 pellet blasting studies

    International Nuclear Information System (INIS)

    Archibald, K.E.


    Initial tests with CO 2 pellet blasting as a decontamination technique were completed in 1993 at the Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory (INEL). During 1996, a number of additional CO 2 pellet blasting studies with Alpheus Cleaning Technologies, Oak Ridge National Laboratory, and Pennsylvania State University were conducted. After the testing with Alpheus was complete, an SDI-5 shaved CO 2 blasting unit was purchased by the ICPP to test and determine its capabilities before using in ICPP decontamination efforts. Results of the 1996 testing will be presented in this report

  16. CO2 capture-sequestration

    International Nuclear Information System (INIS)

    Huffer, Elisabeth


    CO 2 capture-sequestration could be an acceptable temporary solution for the abatement of greenhouse gas releases to the atmosphere, before the implementation of new carbon-free power generation means. This paper briefly summarizes the principles of this technology: capture (post-combustion, oxi-combustion, pre-combustion); CO 2 transport and sequestration (deep saline aquifers, injection in depleted hydrocarbon reservoirs, injection in abandoned coal seams); examples of operations in progress

  17. The idea of global CO2 trade

    International Nuclear Information System (INIS)

    Svendsen, G.T.


    The US has been criticized for wanting to earn a fortune on a global CO 2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO 2 market may provide the world with an epoch-making means of cost-effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO 2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future

  18. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard


    The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost......-effective control which can solve future global environmental problems. The economic gains from 'hot air' distributions of permits and CO2 trade make the system politically attractive to potential participants. For example, vital financial subsidies from the EU to Eastern Europe are to be expected. It will probably...... not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further profitable trade. Also, a periodical renewal of permits makes it possible to tighten target levels in the future....

  19. Assessment of CO2 free energy options

    International Nuclear Information System (INIS)

    Cavlina, N.; Raseta, D.; Matutinovic, I.


    One of the European Union climate and energy targets is to significantly reduce CO 2 emissions, at least 20% by 2020, compared to 1990. In the power industry, most popular solution is use of solar and wind power. Since their production varies significantly during the day, for the purpose of base-load production they can be paired with gas-fired power plant. Other possible CO 2 -free solution is nuclear power plant. This article compared predicted cost of energy production for newly built nuclear power plant and newly built combination of wind or solar and gas-fired power plant. Comparison was done using Levelized Unit of Energy Cost (LUEC). Calculations were performed using the Monte Carlo method. For input parameters that have biggest uncertainty (gas cost, CO 2 emission fee) those uncertainties were addressed not only through probability distribution around predicted value, but also through different scenarios. Power plants were compared based on their economic lifetime. (authors)


    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Faulkner, David; Sullivan, Douglas P.


    Are the carbon dioxide (CO2) sensors in your demand controlled ventilation systems sufficiently accurate? The data from these sensors are used to automatically modulate minimum rates of outdoor air ventilation. The goal is to keep ventilation rates at or above design requirements while adjusting the ventilation rate with changes in occupancy in order to save energy. Studies of energy savings from demand controlled ventilation and of the relationship of indoor CO2 concentrations with health and work performance provide a strong rationale for use of indoor CO2 data to control minimum ventilation rates1-7. However, this strategy will only be effective if, in practice, the CO2 sensors have a reasonable accuracy. The objective of this study was; therefore, to determine if CO2 sensor performance, in practice, is generally acceptable or problematic. This article provides a summary of study methods and findings ? additional details are available in a paper in the proceedings of the ASHRAE IAQ?2007 Conference8.

  1. Increases in CO2 from past low to future high levels result in “slower” strategies on the leaf economic spectrum

    NARCIS (Netherlands)

    Temme, Andries A.; Liu, Jin Chun; van Hal, Jurgen; Cornwell, Will K.; Cornelissen, Johannes (Hans) H.C.; Aerts, Rien


    Depending on resource availability plants exhibit a specific suite of traits. At the interspecific level these traits follow the leaf economic spectrum (LES), traits related to slow turnover when resources are poor and fast turnover when resources are plentiful. Limited data shows that within

  2. Effect of temperature and CO2-enrichment on photosynthesis and the levels of carbohydrates and isoprenoid pathway products in guayule, a latex producing shrub (United States)

    The stems and roots of the desert shrub guayule, Parthenium argentatum, contain a significant amount of latex, a potential source of natural rubber. To determine the factors regulating carbon partitioning, net photosynthesis (Pn) and the levels of carbohydrates and isoprenoid compounds were measured...

  3. Short-term CO2 exchange response to temperature, irradiance, and CO2 concentration in strawberry. (United States)

    Campbell, D E; Young, R


    Relative importance of short-term environmental interaction and preconditioning to CO2 exchange response was examined in Fragaria ananasa (strawberry, cv. Quinault). Tests included an orthogonal comparison of 15 to 60-min and 6 to 7-h exposures to different levels of temperature (16 to 32°C), photosynthetically active radiation (PAR, 200 to 800 μE m(2) s(-1)), and CO2 (300 to 600 μl/l) on successive days of study. Plants were otherwise maintained at 21°C, 300 μE m(2) s(-1) PAR and 300-360 μl/l CO2 as standard conditions. Treatment was restricted to the mean interval of 14 h daily illumination and the first 3-4 days of each test week over a 12-week cultivation period. CO2 exchange rates were followed with each step-change in environmental level including ascending/descending temperature/PAR within a test period, initial response at standard conditions on successive days of testing, and measurement at reduced O2. Response generally supported prior concepts of leaf biochemical modeling in identifying CO2 fixation as the major site of environmental influence, while overall patterns of whole plant CO2 exchange suggested additional effects for combined environmental factors and preconditioning. These included a positive interaction between temperature and CO2 concentration on photosynthesis at high irradiance and a greater contribution by 'dark' respiration at lower PAR than previously indicated. The further importance of estimating whole plant CO2 exchange from repetitive tests and measurements was evidenced by a high correlation of response to prior treatment both during the daily test period and on consecutive days of testing.

  4. Spectroscopic properties of five-coordinated Co2+ in phosphates. (United States)

    Hunault, M; Robert, J-L; Newville, M; Galoisy, L; Calas, G


    Co3(PO4)2, SrCo2(PO4)2, Co2P2O7, BaCoP2O7 and SrCoP2O7 present different geometries of five-coordinated Co(2+) (([5])Co(2+)) sites, coexisting with ([6])Co(2+) in Co3(PO4)2 and Co2P2O7, and ([4])Co(2+) in SrCo2(PO4)2. ([5])Co K-edge XANES spectra show that the intensity of the pre-edge and main-edge is intermediate between those of ([6])- and ([4])Co. Diffuse reflectance spectra show the contributions of Co(2+) in (D3h) symmetry for SrCo2(PO4)2, and (C4v) symmetry for BaCoP2O7 and SrCoP2O7. In Co3(PO4)2 and Co2P2O7 the multiple transitions observed arise from energy level splitting and may be labeled in (C2v) symmetry. Spectroscopic data confirm that (D3h) and (C4v) symmetries may be distinguished upon the intensity of the optical absorption bands and crystal field splitting values. We discuss the influence of the geometrical distortion and of the nature of the next nearest neighbors. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. 10 MW Supercritical CO2 Turbine Test

    Energy Technology Data Exchange (ETDEWEB)

    Turchi, Craig


    The Supercritical CO2 Turbine Test project was to demonstrate the inherent efficiencies of a supercritical carbon dioxide (s-CO2) power turbine and associated turbomachinery under conditions and at a scale relevant to commercial concentrating solar power (CSP) projects, thereby accelerating the commercial deployment of this new power generation technology. The project involved eight partnering organizations: NREL, Sandia National Laboratories, Echogen Power Systems, Abengoa Solar, University of Wisconsin at Madison, Electric Power Research Institute, Barber-Nichols, and the CSP Program of the U.S. Department of Energy. The multi-year project planned to design, fabricate, and validate an s-CO2 power turbine of nominally 10 MWe that is capable of operation at up to 700°C and operates in a dry-cooled test loop. The project plan consisted of three phases: (1) system design and modeling, (2) fabrication, and (3) testing. The major accomplishments of Phase 1 included: Design of a multistage, axial-flow, s-CO2 power turbine; Design modifications to an existing turbocompressor to provide s-CO2 flow for the test system; Updated equipment and installation costs for the turbomachinery and associated support infrastructure; Development of simulation tools for the test loop itself and for more efficient cycle designs that are of greater commercial interest; Simulation of s-CO2 power cycle integration into molten-nitrate-salt CSP systems indicating a cost benefit of up to 8% in levelized cost of energy; Identification of recuperator cost as a key economic parameter; Corrosion data for multiple alloys at temperatures up to 650ºC in high-pressure CO2 and recommendations for materials-of-construction; and Revised test plan and preliminary operating conditions based on the ongoing tests of related equipment. Phase 1 established that the cost of the facility needed to test the power turbine at its full power and temperature would exceed the planned funding for Phases 2 and 3. Late

  6. CO2 storage in Sweden

    International Nuclear Information System (INIS)

    Ekstroem, Clas; Andersson, Annika; Kling, Aasa; Bernstone, Christian; Carlsson, Anders; Liljemark, Stefan; Wall, Caroline; Erstedt, Thomas; Lindroth, Maria; Tengborg, Per; Edstroem, Mikael


    This study considers options, that could be feasible for Sweden, to transport and geologically store CO 2 , providing that technology for electricity production with CO 2 capture will be available in the future and also acceptable from cost- and reliability point of view. As a starting point, it is assumed that a new 600-1000 MW power plant, fired with coal or natural gas, will be constructed with CO 2 capture and localised to the Stockholm, Malmoe or Goeteborg areas. Of vital importance for storage of carbon dioxide in a reservoir is the possibility to monitor its distribution, i.e. its migration within the reservoir. It has been shown in the SACS-project that the distribution of carbon dioxide within the reservoir can be monitored successfully, mainly by seismic methods. Suitable geologic conditions and a large storage potential seems to exist mainly in South West Scania, where additional knowledge on geology/hydrogeology has been obtained since the year 2000 in connection to geothermal energy projects, and in the Eastern part of Denmark, bordering on South West Scania. Storage of carbon dioxide from the Stockholm area should not be excluded, but more studies are needed to clarify the storage options within this area. The possibilities to use CO 2 for enhanced oil recovery, EOR, in i.a. the North Sea should be investigated, in order to receive incomes from the CO 2 and shared costs for infrastructure, and by this also make the CO 2 regarded as a trading commodity, and thereby achieving a more favourable position concerning acceptance, legal issues and regulations. The dimensions of CO 2 -pipelines should be similar to those for natural natural gas, although regarding some aspects they have different design and construction prerequisites. To obtain cost efficiency, the transport distances should be kept short, and possibilities for co-ordinated networks with short distribution pipelines connected to common main pipelines, should be searched for. Also, synergies

  7. The CO2nnect activities (United States)

    Eugenia, Marcu


    Climate change is one of the biggest challenges we face today. A first step is the understanding the problem, more exactly what is the challenge and the differences people can make. Pupils need a wide competencies to meet the challenges of sustainable development - including climate change. The CO2nnect activities are designed to support learning which can provide pupils the abilities, skills, attitudes and awareness as well as knowledge and understanding of the issues. The project "Together for a clean and healthy world" is part of "The Global Educational Campaign CO2nnect- CO2 on the way to school" and it was held in our school in the period between February and October 2009. It contained a variety of curricular and extra-curricular activities, adapted to students aged from 11 to 15. These activities aimed to develop in students the necessary skills to understanding man's active role in improving the quality of the environment, putting an end to its degrading process and to reducing the effects of climate changes caused by the human intervention in nature, including transport- a source of CO2 pollution. The activity which I propose can be easily adapted to a wide range of age groups and linked to the curricula of many subjects: - Investigate CO2 emissions from travel to school -Share the findings using an international database -Compare and discuss CO2 emissions -Submit questions to a climate- and transport expert -Partner with other schools -Meet with people in your community to discuss emissions from transport Intended learning outcomes for pupils who participate in the CO2nnect campaign are: Understanding of the interconnected mobility- and climate change issue climate change, its causes and consequences greenhouse-gas emissions from transport and mobility the interlinking of social, environmental, cultural and economic aspects of the local transport system how individual choices and participation can contribute to creating a more sustainable development

  8. Elevated CO2enhances resprouting of a tropical savanna tree. (United States)

    Hoffmann, W A; Bazzaz, F A; Chatterton, N J; Harrison, P A; Jackson, R B


    The savannas (cerrado) of south-central Brazil are currently subjected to frequent anthropogenic burning, causing widespread reduction in tree density. Increasing concentrations of atmospheric CO 2 could reduce the impact of such frequent burning by increasing the availability of nonstructural carbohydrate, which is necessary for resprouting. We tested the hypotheses that elevated CO 2 stimulates resprouting and accelerates replenishment of carbohydrate reserves. Using a factorial experiment, seedlings of a common Brazilian savanna tree, Keilmeyera coriacea, were grown at 350 ppm and 700 ppm CO 2 and at two nutrient levels. To simulate burning, the plants were either clipped at 15 weeks or were left unclipped. Among unclipped plants, CO 2 and nutrients both stimulated growth, with no significant interaction between nutrient and CO 2 effects. Among clipped plants, both CO 2 and nutrients stimulated resprouting. However, there was a strong interaction between CO 2 and nutrient effects, with CO 2 having a significant effect only in the presence of high nutrient availability. Under elevated CO 2 , carbohydrate reserves remained at higher levels following clipping. Root total nonstructural carbohydrate remained above 36% in all treatments, so carbohydrate reserves did not limit regrowth. These results indicate that under elevated CO 2 this species may be better able to endure the high frequency of anthropogenic burning in the Brazilian savannas.

  9. CO2 capture by gas hydrate crystallization: Application on the CO2-N2 mixture

    International Nuclear Information System (INIS)

    Bouchemoua, A.


    CO 2 capture and sequestration represent a major industrial and scientific challenge of this century. There are different methods of CO 2 separation and capture, such as solid adsorption, amines adsorption and cryogenic fractionation. Although these processes are well developed at industrial level, they are energy intensive. Hydrate formation method is a less energy intensive and has an interesting potential to separate carbon dioxide. Gas hydrates are Document crystalline compounds that consist of hydrogen bonded network of water molecules trapping a gas molecule. Gas hydrate formation is favored by high pressure and low temperature. This study was conducted as a part of the SECOHYA ANR Project. The objective is to study the thermodynamic and kinetic conditions of the process to capture CO 2 by gas hydrate crystallization. Firstly, we developed an experimental apparatus to carry out experiments to determine the thermodynamic and kinetic formation conditions of CO 2 -N 2 gas hydrate mixture in water as liquid phase. We showed that the operative pressure may be very important and the temperature very low. For the feasibility of the project, we used TBAB (Tetrabutylammonium Bromide) as thermodynamic additive in the liquid phase. The use of TBAB may reduce considerably the operative pressure. In the second part of this study, we presented a thermodynamic model, based on the van der Waals and Platteeuw model. This model allows the estimation of thermodynamic equilibrium conditions. Experimental equilibrium data of CO 2 -CH 4 and CO 2 -N 2 mixtures are presented and compared to theoretical results. (author)

  10. CO2 emissions in the World in 2013

    International Nuclear Information System (INIS)

    Ecoiffier, Mathieu


    This publication presents and comments data of CO 2 emissions in the world and their evolution. It more particularly addresses CO 2 emissions due to energy combustion which represent more than 80 per cent of these emissions or 62 per cent of greenhouse gas emissions, and which increased in 2013 with respect to 2012 (+ 2.2 pc). The distribution of CO 2 emissions due to energy combustion in different continents and regions is indicated (levels in 1990, 2012 and 2013, evolutions). The decrease of the CO 2 emission intensity with respect to the GDP is briefly commented (evolution since 1970), as well as the level of CO 2 emissions per inhabitant in China with respect to that in the EU (evolutions since 1970). The evolution of CO 2 emissions is then analysed with respect to different determining parameters according to the Kaya equation (population, GDP, primary energy consumption and their evolution or relationship one to each other)

  11. CO2 emissions of nuclear electricity generation

    International Nuclear Information System (INIS)

    Wissel, Steffen; Mayer-Spohn, Oliver; Fahl, Ulrich; Blesl, Markus; Voss, Alfred


    A survey of LCA studies on nuclear electricity generation revealed life cycle CO 2 emissions ranging between 3 g/kWhe to 60 g/kWhe and above. Firstly, this paper points out the discrepancies in studies by estimating the CO 2 emissions of nuclear power generation. Secondly, the paper sets out to provide critical review of future developments of the fuel cycle for light water reactors and illustrates the impact of uncertainties on the specific CO 2 emissions of nuclear electricity generation. Each step in the fuel cycle will be considered and with regard to the CO 2 emissions analysed. Thereby different assumptions and uncertainty levels are determined for the nuclear fuel cycle. With the impacts of low uranium ore grades for mining and milling as well as higher burn-up rates future fuel characteristics are considered. Sensitivity analyses are performed for all fuel processing steps, for different technical specifications of light water reactors as well as for further external frame conditions. (authors)

  12. Evaluation of transcription levels of inlA, inlB, hly, bsh and prfA genes in Listeria monocytogenes strains using quantitative reverse-transcription PCR and ability of invasion into human CaCo-2 cells. (United States)

    Tamburro, Manuela; Sammarco, Michela Lucia; Ammendolia, Maria Grazia; Fanelli, Incoronata; Minelli, Fabio; Ripabelli, Giancarlo


    Listeria monocytogenes virulence depends on the activity of well-characterized virulence factors. In this study, transcription levels of inlA, inlB, hly, bsh and prfA genes in L. monocytogenes strains, and the ability of invasion into CaCo-2 cells were investigated. Serotyping, multiplex-PCR for serovar identification and restriction fragment analysis of inlA were performed. Transcription levels and invasiveness were evaluated by quantitative reverse-transcription PCR and by in vitro assays, respectively. The isolates were of serovars 1/2a, 4b, 1/2c, 1/2b and 3a. Full-length inlA profiles were found for nine of ten clinical isolates, while five of seven cultures from foods showed truncated profile. The analysis of transcription levels of virulence factors encoding genes demonstrated a substantial inter-strain heterogeneity, with clinical strains showing higher levels for almost all genes than isolates from food. A correlation between transcription levels of inlA and inlB, as well as between bsh and prfA, was observed. Significant differences between clinical strains and food isolates in the invasion of CaCo-2 cells were found. Analysis of gene transcription and invasiveness of human cells suggests different virulence phenotypes among L. monocytogenes populations, and this characterization could be a useful tool for risk assessment purposes and for the development of public health strategies. © FEMS 2015. All rights reserved. For permissions, please e-mail:

  13. Nuclear power and CO2

    International Nuclear Information System (INIS)

    Chawla, R.


    Temperatures in the atmosphere have risen by nearly one degree in the twentieth century. To contain changes in global climate and their consequences, worldwide emissions of CO 2 need to be curbed drastically in the future. Even if CO 2 emissions are not taken into account, nuclear power has no economic disadvantages compared to fossil fuels. On the basis of an amount of money per ton of carbon emitted, nuclear power is cheaper than coal and, in most cases, also than natural gas. Actually, the worldwide CO 2 problem and energy generation are part of the ongoing 'sustainability' debate. The following arguments, among others, used in the discussion show the sustainable character of nuclear power: - Comparison of the risks associated with major accidents for various sources of energy show nuclear power to be relatively free from hazard. - The introduction of fast breeders and other technical factors will make it possible to use nuclear fission as an important source of energy for many centuries. - The radiotoxicity of waste over very long periods of time can be influenced, for instance, by transmutation. The need to further develop CO 2 -free nuclear power has been recognized by many countries, among them Switzerland. The Generation IV International Forum (GIF) works towards developing a new generation of nuclear power plants by 2030. It will be the symbiosis of the new types of reactors with today's modern plants which finally will establish CO 2 -free nuclear fission as a sustainable cornerstone of energy generation worldwide. That nuclear power has this potential for further development must be acknowledged generally. (orig.)

  14. The CO2-tax and its ability to reduce CO2 emissions related to oil and gas production in Norway

    International Nuclear Information System (INIS)

    Roemo, F.; Lund, M.W.


    The primary ambition of the paper is to illustrate some relevant effects of the CO 2 -tax, and draw the line from company adaptation via national ambitions and goals to global emission consequences. The CO 2 -tax is a success for oil and gas production only to the extent that the CO 2 emission per produced unit oil/gas is reduced as a consequence of the tax. If not, the CO 2 -tax is a pure fiscal tax and has no qualitative impact on the CO 2 emissions. The reduction potential is then isolated to the fact that some marginal fields will not be developed, and the accelerated close down of fields in production. The paper indicates that a significant replacement of older gas turbines at a certain level of the CO 2 -tax could be profitable for the companies. This is dependent on change in turbine energy utilization, and the investment cost. The CO 2 -tax is a political success for the nation if it is a significant contributor to achieve national emission goals. Furthermore, is the CO 2 -tax an environmental success only to the extent it contributes to reductions in the CO 2 emissions globally. The paper indicates that there are possibilities for major suboptimal adaptations in connection with national CO 2 -taxation of the oil and gas production. 13 refs., 6 figs

  15. Fang CO2 med Aminosyrer

    DEFF Research Database (Denmark)

    Lerche, Benedicte Mai


    Med såkaldte “carbon capture-teknikker” er det muligt at rense røgen fra kulfyrede kraftværker, således at den er næsten helt fri for drivhusgassen CO2. Kunsten er at gøre processen tilstrækkeligt billig. Et lovende fangstredskab i denne proces er aminosyrer.......Med såkaldte “carbon capture-teknikker” er det muligt at rense røgen fra kulfyrede kraftværker, således at den er næsten helt fri for drivhusgassen CO2. Kunsten er at gøre processen tilstrækkeligt billig. Et lovende fangstredskab i denne proces er aminosyrer....

  16. Global energy / CO2 projections

    International Nuclear Information System (INIS)

    Sinyak, Y.


    Section headings are: (1) Social and economic problems of the 21 st century and the role of energy supply systems (2) Energy-environment interactions as a central point of energy research activities (3) New ways of technological progress and its impacts on energy demand and supply (4) Long-term global energy projections (5) Comparative analysis of global long-term energy / CO 2 studies (6) Conclusions. The author shows that, in order to alleviate the negative impacts of energy systems on the climate, it will be necessary to undertake tremendous efforts to improve the energy use efficiency, to drastically change the primary energy mix, and, at the same time, to take action to reduce greenhouse emissions from other sources and increase the CO 2 sink through enhanced reforestation. (Quittner)

  17. CO2 reduction by dematerialization

    Energy Technology Data Exchange (ETDEWEB)

    Hekkert, M.P. [Department of Innovation Studies, Copernicus Institute, Utrecht University, Utrecht (Netherlands)


    Current policy for the reduction of greenhouse gases is mainly concerned with a number of types of solutions: energy saving, shifting to the use of low-carbon fuels and the implementation of sustainable energy technologies. Recent research has shown that a strategy directed at a more efficient use of materials could make a considerable contribution to reducing CO2 emissions. Moreover, the costs to society as a whole of such a measure appear to be very low.

  18. CO2 blasting in Europe

    International Nuclear Information System (INIS)

    Vankerckhoven, Patrick


    Carbon dioxide blasting can be used during the lifetime of nuclear facilities to remove deposited contamination and reduce the dose to personnel during repair and maintenance. By contrast with conventional mechanical or chemical decontamination methods, it does not leave additional secondary wastes. During the process, liquid CO 2 is expanded and converted into dry snow which is compressed and extruded to form small dry ice pellets. These low temperature pellets are blasted at high speed in a stream of compressed air against the surface to be treated where the mechanical and thermal shock embrittles the contaminating layer and severs its bond with the surface. The dry ice sublimes into the atmosphere as CO 2 gas and the loosened contamination can be removed via a ventilation and filtration system. Some examples of the effective use of CO 2 blasting are given. They include decontamination of: a supercompactor used on radioactive waste drums; the walls and floors of a nuclear fuel fabrication plant; the vacuum vessel of the Joint European Torus, hot cells; a phosphate fertilizer plant contaminated by radium 226. (UK)

  19. Improving CO2 permeation and separation performance of CO2-philic polymer membrane by blending CO2 absorbents (United States)

    Cheng, Jun; Hu, Leiqing; Li, Yannan; Liu, Jianzhong; Zhou, Junhu; Cen, Kefa


    To research effects of CO2 absorption capacity and type of CO2 absorbent on the CO2 separation and free-volume properties of facilitated transport membranes, two types of CO2 absorbents, namely monoethanolamine (MEA) and ionic liquids (ILs:[P66614][Triz] and [P66614][2-Op]), were adopted. The CO2 absorption capacities of MEA, [P66614][Triz] and [P66614][2-Op] were about 0.561 mol CO2 per mol, 0.95 mol CO2 per mol and 1.60 mol CO2 per mol, respectively. All mean free-volume hole radiuses of membranes decreased after blending CO2 absorbents. After polymer membrane blended with two ILs, number of free-volume hole increased, resulting in modest increase of the fractional free volume. Both CO2 permeability and selectivity increased after blending MEA and ILs. The increasing range of CO2 permeability corresponded with CO2 absorption capacity of CO2 absorbents, and membrane blending with [P66614][2-Op] showed the highest CO2 permeability of 672.1 Barrers at 25 °C. Pebax/PEGDME membrane blending with MEA obtained the highest CO2/H2 and CO2/CH4 selectivity at 17.8 and 20.5, respectively.

  20. Implications of overestimated anthropogenic CO2 emissions on East Asian and global land CO2 flux inversion (United States)

    Saeki, Tazu; Patra, Prabir K.


    Measurement and modelling of regional or country-level carbon dioxide (CO2) fluxes are becoming critical for verification of the greenhouse gases emission control. One of the commonly adopted approaches is inverse modelling, where CO2 fluxes (emission: positive flux, sink: negative flux) from the terrestrial ecosystems are estimated by combining atmospheric CO2 measurements with atmospheric transport models. The inverse models assume anthropogenic emissions are known, and thus the uncertainties in the emissions introduce systematic bias in estimation of the terrestrial (residual) fluxes by inverse modelling. Here we show that the CO2 sink increase, estimated by the inverse model, over East Asia (China, Japan, Korea and Mongolia), by about 0.26 PgC year-1 (1 Pg = 1012 g) during 2001-2010, is likely to be an artifact of the anthropogenic CO2 emissions increasing too quickly in China by 1.41 PgC year-1. Independent results from methane (CH4) inversion suggested about 41% lower rate of East Asian CH4 emission increase during 2002-2012. We apply a scaling factor of 0.59, based on CH4 inversion, to the rate of anthropogenic CO2 emission increase since the anthropogenic emissions of both CO2 and CH4 increase linearly in the emission inventory. We find no systematic increase in land CO2 uptake over East Asia during 1993-2010 or 2000-2009 when scaled anthropogenic CO2 emissions are used, and that there is a need of higher emission increase rate for 2010-2012 compared to those calculated by the inventory methods. High bias in anthropogenic CO2 emissions leads to stronger land sinks in global land-ocean flux partitioning in our inverse model. The corrected anthropogenic CO2 emissions also produce measurable reductions in the rate of global land CO2 sink increase post-2002, leading to a better agreement with the terrestrial biospheric model simulations that include CO2-fertilization and climate effects.

  1. Comparison of CO2 Photoreduction Systems: A Review (United States)

    Carbon dioxide (CO2) emissions are a major contributor to the climate change equation. To alleviate concerns of global warming, strategies to mitigate increase of CO2 levels in the atmosphere have to be developed. The most desirable approach is to convert the carbon dioxide to us...

  2. Acute and Chronic Exposure to CO2 in Space Flight (United States)

    Alexander, D.; Wu, J.; Barr, Y. R.; Watkins, S. D.


    Spacecraft and space stations, similar to other habitable confined spaces such as submarines, need to provide a breathable atmosphere for their inhabitants. The inevitable production of CO2 during respiration necessitates life support systems that "scrub" the atmosphere and lower CO2 levels. Due to operational limitations associated with space flight (limited mass, volume, power, and consumables) CO2 is not scrubbed down to its terrestrial equivalent of 0.03% CO2 (ppCO2 of 0.23 mmHg), but is kept below 0.7% (ppCO2 of 5.3 mmHg), a level established in NASA s 180-day mission Spacecraft Maximum Allowable Concentration (SMAC) to be safe and unlikely to cause symptoms. Reports of space flight crewmembers becoming symptomatic with headaches, fatigue, and malaise at levels below those known to cause such symptoms terrestrially has prompted studies measuring the levels of CO2 on both the space shuttle and the space station. Data from cabin atmosphere sampling were collected on space shuttle missions STS-113, STS-122, STS-123, and International Space Station Expeditions 12-15 and 17, and the measured CO2 levels were then correlated to symptoms reported by the crew. The results indicate that a correlation exists between CO2 levels and symptomatology, however causality cannot be established at this time. While the short-term effects of elevated CO2 exposure are well known terrestrially, less is known regarding potential long-term effects of prolonged exposure to a CO2-rich environment or how the physiological changes caused by microgravity may interact with such exposures. Other challenges include limitations in the CO2 monitors used, lack of convection in the microgravity environment, and formation of localized CO2 pockets. As it is unclear if the unique environment of space increases sensitivity to CO2 or if other confounding factors are present, further research is planned to elucidate these points. At the same time, efforts are underway to update the SMAC to a lower level

  3. Possible impacts of CO2 storage on the marine environment

    International Nuclear Information System (INIS)

    Poremski, H.J.


    This study examined the potential impacts of deep-sea carbon dioxide (CO 2 ) sequestration on the marine environment. The upper layers of oceans are currently saturated with CO 2 , while deeper ocean waters remain undersaturated. Arctic and Antarctic waters have higher uptake rates of CO 2 due to their lower temperatures. CO 2 deposited in Arctic and Antarctic waters sinks to the bottom of the ocean, and is then transported to equatorial latitudes, where stored amounts of CO 2 that are not fixed by biochemical processes will be released and enter the atmosphere again after a period of approximately 1000 years. Nearly 50 per cent of CO 2 fixation occurs as a result of phytoplankton growth, which is dependent on the availability of a range of nutrients, essential trace metals, and optimal physical conditions. Fertilization-induced CO 2 fixation in the sediments of southern oceans will result in nutrient depletion of bottom layers, which will in turn result in lower primary production levels at equatorial latitudes. Current modelling approaches to CO 2 injection assume that the injected CO 2 will dissolve in a plume extending 100 m around a riser. Retention times of several hundred years are anticipated. However, further research is needed to investigate the efficacy of CO 2 deep ocean storage technologies. Increased CO 2 uptake can also increase the formation of bicarbonate (HCO 3 ) acidification, decrease pH values, and inhibit the formation of biomass in addition to impacting on the calcification of many organisms. It was concluded that ocean storage by injection or deep storage is an untenable option at present due to the fact that the effects of excessive CO 2 in marine environments are not fully understood. 22 refs., 2 tabs

  4. CO2 Emissions From Fuel Combustion. Highlights. 2013 Edition

    Energy Technology Data Exchange (ETDEWEB)



    In the lead-up to the UN climate negotiations in Warsaw, the latest information on the level and growth of CO2 emissions, their source and geographic distribution will be essential to lay the foundation for a global agreement. To provide input to and support for the UN process, the IEA is making available for free download the ''Highlights'' version of CO2 Emissions from Fuel Combustion now for sale on IEA Bookshop. This annual publication contains, for more than 140 countries and regions: estimates of CO2 emissions from 1971 to 2011; selected indicators such as CO2/GDP, CO2/capita, CO2/TPES and CO2/kWh; a decomposition of CO2 emissions into driving factors; and CO2emissions from international marine and aviation bunkers, key sources, and other relevant information. The nineteenth session of the Conference of the Parties to the Climate Change Convention (COP-19), in conjunction with the ninth meeting of the Parties to the Kyoto Protocol (CMP 9), met in Warsaw, Poland from 11 to 22 November 2013. This volume of ''Highlights'', drawn from the full-scale study, was specially designed for delegations and observers of the meeting in Warsaw.


    Directory of Open Access Journals (Sweden)

    Zofia LUBAŃSKA

    Full Text Available Z pojęciem ochrony środowiska wiąże się bardzo szeroko w ostatnim czasie omawiane zagadnienie dotyczące ograniczenia emisji CO2. Konsekwencją globalnych zmian klimatu wywołanego przez ludzi jest wzrost stężenia atmosferycznego gazów cieplarnianych, które powodują nasilający się efekt cieplarniany. Wzrasta na świecie liczba ludności, a co za tym idzie wzrasta konsumpcja na jednego mieszkańca, szczególnie w krajach szeroko rozwiniętych gospodarczo. Protokół z Kioto ściśle określa działania jakie należy podjąć w celu zmniejszenia stężenia dwutlenku węgla w atmosferze. Pomimo maksymalnej optymalizacji procesu spalania paliw kopalnianych wykorzystywanych do produkcji energii, zastosowania odnawialnych źródeł energii zmiana klimatu jest nieunikniona i konsekwentnie będzie postępować przez kolejne dekady. Prognozuje się, że duże znaczenie odegra nowoczesna technologia, która ma za zadanie wychwycenie CO2 a następnie składowanie go w odpowiednio wybranych formacjach geologicznych (CCS- Carbon Capture and Storage. Eksperci są zgodni, że ta technologia w niedalekiej przyszłości stanie się rozwiązaniem pozwalającym ograniczyć ogromną ilość emisji CO2 pochodzącą z procesów wytwarzania energii z paliw kopalnych. Z analiz Raportu IPCC wynika, iż technologia CSS może się przyczynić do ok. 20% redukcji emisji dwutlenku węgla przewidzianej do 2050 roku [3]. Zastosowanie jej napotyka na wiele barier, nie tylko technologicznych i ekonomicznych, ale także społecznych. Inną metodą dającą ujemne źródło emisji CO2 jest możliwość wykorzystania obszarów leśnych o odpowiedniej strukturze drzewostanu. Środkiem do tego celu, oprócz ograniczenia zużycia emisjogennych paliw kopalnych (przy zachowaniu zasad zrównoważonego rozwoju może być intensyfikacja zalesień. Zwiększanie lesistości i prawidłowa gospodarka leśna należy do najbardziej efektywnych sposobów kompensowania

  6. Leakage and Seepage of CO2 from Geologic Carbon Sequestration Sites: CO2 Migration into Surface Water

    International Nuclear Information System (INIS)

    Oldenburg, Curt M.; Lewicki, Jennifer L.


    Geologic carbon sequestration is the capture of anthropogenic carbon dioxide (CO 2 ) and its storage in deep geologic formations. One of the concerns of geologic carbon sequestration is that injected CO 2 may leak out of the intended storage formation, migrate to the near-surface environment, and seep out of the ground or into surface water. In this research, we investigate the process of CO 2 leakage and seepage into saturated sediments and overlying surface water bodies such as rivers, lakes, wetlands, and continental shelf marine environments. Natural CO 2 and CH 4 fluxes are well studied and provide insight into the expected transport mechanisms and fate of seepage fluxes of similar magnitude. Also, natural CO 2 and CH 4 fluxes are pervasive in surface water environments at levels that may mask low-level carbon sequestration leakage and seepage. Extreme examples are the well known volcanic lakes in Cameroon where lake water supersaturated with respect to CO 2 overturned and degassed with lethal effects. Standard bubble formation and hydrostatics are applicable to CO 2 bubbles in surface water. Bubble-rise velocity in surface water is a function of bubble size and reaches a maximum of approximately 30 cm s -1 at a bubble radius of 0.7 mm. Bubble rise in saturated porous media below surface water is affected by surface tension and buoyancy forces, along with the solid matrix pore structure. For medium and fine grain sizes, surface tension forces dominate and gas transport tends to occur as channel flow rather than bubble flow. For coarse porous media such as gravels and coarse sand, buoyancy dominates and the maximum bubble rise velocity is predicted to be approximately 18 cm s -1 . Liquid CO 2 bubbles rise slower in water than gaseous CO 2 bubbles due to the smaller density contrast. A comparison of ebullition (i.e., bubble formation) and resulting bubble flow versus dispersive gas transport for CO 2 and CH 4 at three different seepage rates reveals that

  7. Reconsideration of atmospheric CO2 lifetime: potential mechanism for explaining CO2 missing sink (United States)

    Kikuchi, R.; Gorbacheva, T.; Gerardo, R.


    Carbon cycle data (Intergovernmental Panel on Climate Change 1996) indicate that fossil fuel use accounts for emissions to the atmosphere of 5.5±0.5 GtC (Gigatons of carbon) annually. Other important processes in the global CO2 budget are tropical deforestation, estimated to generate about 1.6±1.0 GtC/yr; absorption by the oceans, removing about 2.0±0.8 GtC/yr; and regrowth of northern forests, taking up about 0.5±0.5 GtC/yr. However, accurate measurements of CO2 show that the atmosphere is accumulating only about 3.3±0.2 GtC/yr. The imbalance of about 1.3±1.5 GtC/yr, termed the "missing sink", represents the difference between the estimated sources and the estimated sinks of CO2; that is, we do not know where all of the anthropogenic CO2 is going. Several potential mechanisms have been proposed to explain this missing carbon, such as CO2 fertilization, climate change, nitrogen deposition, land use change, forest regrowth et al. Considering the complexity of ecosystem, most of ecosystem model cannot handle all the potential mechanisms to reproduce the real world. It has been believed that the dominant sink mechanism is the fertilizing effects of increased CO2 concentrations in the atmosphere and the addition to soils of fixed nitrogen from fossil-fuel burning and agricultural fertilizers. However, a recent analysis of long-term observations of the change in biomass and growth rates suggests that such fertilization effects are much too small to explain more than a small fraction of the observed sink. In addition, long-term experiments in which small forest patches and other land ecosystems have been exposed to elevated CO2 levels for extended periods show a rapid decrease of the fertilization effect after an initial enhancement. We will explore this question of the missing sink in atmospheric CO2 residence time. Radioactive and stable carbon isotopes (13-C/12-C) show the real CO2 lifetime is about 5 years; i.e. CO2 is quickly taken out of the atmospheric

  8. Chemical reactions occurring during direct solar reduction of CO2. (United States)

    Lyma, J L; Jensen, R J


    At high temperatures carbon dioxide may absorb solar radiation and react to form carbon monoxide and molecular oxygen. The CO, so produced, may be converted by well-established means to a combustible fuel, such as methanol. We intend to make a future demonstration of the solar reduction of CO2 based on these processes. This paper, however, addresses only the problem of preserving, or even enhancing, the initial photolytic CO by quenching the hot gas with colder H2O or CO2. We present model calculations with a reaction mechanism used extensively in other calculations. If a CO2 gas stream is heated and photolyzed by intense solar radiation and then allowed to cool slowly, it will react back to the initial CO2 by a series of elementary chemical reactions. The back reaction to CO2 can be terminated with the rapid addition of CO2, water, or a mixture. Calculations show that a three-fold quench with pure CO2 will stop the reactions and preserve over 90% of the initial photolytic CO. We find that water has one of two effects. It can either increase the CO level, or it can catalyze the recombination of O and CO to CO2. The gas temperature is the determining factor. If the quench gas is not sufficient to keep the temperature below approximately 1100 K, a chain-branching reaction dominates and the reaction to CO2 occurs. If the temperature stays below that level a chain terminating reaction dominates and the CO is increased. The former case occurs below approximately a fourfold quench with a water/CO2 mixture. The later case occurs when the quench is greater than fourfold. We conclude that CO2, H2O, or a mixture may quench the hot gas stream photolyzed by solar radiation and preserve the photolytic CO.

  9. Chemical reactions occurring during direct solar reduction of CO2

    International Nuclear Information System (INIS)

    Lyman, J.L.; Jensen, R.J.


    At high temperatures carbon dioxide may absorb solar radiation and react to form carbon monoxide and molecular oxygen. The CO so produced, may be converted by well-established means to a combustible fuel, such as methanol. We intend to make a future demonstration of the solar reduction of CO 2 based on these processes. This paper, however, addresses only the problem of preserving, or even enhancing, the initial photolytic CO by quenching the hot gas with colder H 2 O or CO 2 . We present model calculations with a reaction mechanism used extensively in other calculations. If a CO 2 gas stream is heated and photolyzed by intense solar radiation and then allowed to cool slowly, it will react back to the initial CO 2 by a series of elementary chemical reactions. The back reaction to CO 2 can be terminated with the rapid addition of CO 2 , water, or a mixture. Calculations show that a three-fold quench with pure CO 2 will stop the reactions and preserve over 90% of the initial photolytic CO. We find that water has one of two effects. It can either increase the CO level, or it can catalyze the recombination of O and CO to CO 2 . The gas temperature is the determining factor. If the quench gas is not sufficient to keep the temperature below approximately 1100 K, a chain-branching reaction dominates and the reaction to CO 2 occurs. If the temperature stays below that level a chain terminating reaction dominates and the CO is increased. The former case occurs below approximately a fourfold quench with a water/CO 2 mixture. The later case occurs when the quench is greater than fourfold. We conclude that CO 2 , H 2 O, or a mixture may quench the hot gas stream photolyzed by solar radiation and preserve the photolytic CO

  10. CO2 on the International Space Station: An Operations Update (United States)

    Law, Jennifer; Alexander, David


    PROBLEM STATEMENT: We describe CO2 symptoms that have been reported recently by crewmembers on the International Space Station and our continuing efforts to control CO2 to lower levels than historically accepted. BACKGROUND: Throughout the International Space Station (ISS) program, anecdotal reports have suggested that crewmembers develop CO2-related symptoms at lower CO2 levels than would be expected terrestrially. Since 2010, operational limits have controlled the 24-hour average CO2 to 4.0 mm Hg, or below as driven by crew symptomatology. In recent years, largely due to increasing awareness by crew and ground team, there have been increased reports of crew symptoms. The aim of this presentation is to discuss recent observations and operational impacts to lower CO2 levels on the ISS. CASE PRESENTATION: Crewmembers are routinely asked about CO2 symptoms in their weekly private medical conferences with their crew surgeons. In recent ISS expeditions, crewmembers have noted symptoms attributable to CO2 starting at 2.3 mmHg. Between 2.3 - 2.7 mm Hg, fatigue and full-headedness have been reported. Between 2.7 - 3.0 mm Hg, there have been self-reports of procedure missed steps or procedures going long. Above 3.0 - 3.4 mm Hg, headaches have been reported. A wide range of inter- and intra-individual variability in sensitivity to CO2 have been noted. OPERATIONAL / CLINICAL RELEVANCE: These preliminary data provide semi-quantitative ranges that have been used to inform a new operational limit of 3.0 mmHg as a compromise between systems capabilities and the recognition that there are human health and performance impacts at recent ISS CO2 levels. Current evidence would suggest that an operational limit between 0.5 and 2.0 mm Hg may maintain health and performance. Future work is needed to establish long-term ISS and future vehicle operational limits.

  11. Transient nature of CO2 fertilization in Arctic tundra (United States)

    Oechel, Walter C.; Cowles, Sid; Grulke, Nancy; Hastings, Steven J.; Lawrence, Bill; Prudhomme, Tom; Riechers, George; Strain, Boyd; Tissue, David; Vourlitis, George


    THERE has been much debate about the effect of increased atmospheric CO2 concentrations on plant net primary production1,3 and on net ecosystem CO2 flux3-10. Apparently conflicting experimental findings could be the result of differences in genetic potential11-15 and resource availability16-20, different experimental conditions21-24 and the fact that many studies have focused on individual components of the system2,21,25-27 rather than the whole ecosystem. Here we present results of an in situ experiment on the response of an intact native ecosystem to elevated CO2. An undisturbed patch of tussock tundra at Toolik Lake, Alaska, was enclosed in greenhouses in which the CO2 level, moisture and temperature could be controlled28, and was subjected to ambient (340 p.p.m.) and elevated (680 p.p.m.) levels of CO2 and temperature (+4 °C). Air humidity, precipitation and soil water table were maintained at ambient control levels. For a doubled CO2 level alone, complete homeostasis of the CO2 flux was re-established within three years, whereas the regions exposed to a combination of higher temperatures and doubled CO2 showed persistent fertilization effect on net ecosystem carbon sequestration over this time. This difference may be due to enhanced sink activity from the direct effects of higher temperatures on growth16,29-33 and to indirect effects from enhanced nutrient supply caused by increased mineralization10,11,19,27,34. These results indicate that the responses of native ecosystems to elevated CO2 may not always be positive, and are unlikely to be straightforward. Clearly, CO2 fertilization effects must always be considered in the context of genetic limitation, resource availability and other such factors.

  12. CO2 point sources and subsurface storage capacities for CO2 in aquifers in Norway

    International Nuclear Information System (INIS)

    Boee, Reidulv; Magnus, Christian; Osmundsen, Per Terje; Rindstad, Bjoern Ivar


    The GESTCO project comprises a study of the distribution and coincidence of thermal CO 2 emission sources and location/quality of geological storage capacity in Europe. Four of the most promising types of geological storage are being studied. 1. Onshore/offshore saline aquifers with or without lateral seal. 2. Low entalpy geothermal reservoirs. 3. Deep methane-bearing coal beds and abandoned coal and salt mines. 4. Exhausted or near exhausted hydrocarbon structures. In this report we present an inventory of CO 2 point sources in Norway (1999) and the results of the work within Study Area C: Deep saline aquifers offshore/near shore Northern and Central Norway. Also offshore/near shore Southern Norway has been included while the Barents Sea is not described in any detail. The most detailed studies are on the Tilje and Aare Formations on the Troendelag Platform off Mid-Norway and on the Sognefjord, Fensfjord and Krossfjord Formations, southeast of the Troll Field off Western Norway. The Tilje Formation has been chosen as one of the cases to be studied in greater detail (numerical modelling) in the project. This report shows that offshore Norway, there are concentrations of large CO 2 point sources in the Haltenbanken, the Viking Graben/Tampen Spur area, the Southern Viking Graben and the central Trough, while onshore Norway there are concentrations of point sources in the Oslofjord/Porsgrund area, along the coast of western Norway and in the Troendelag. A number of aquifers with large theoretical CO 2 storage potential are pointed out in the North Sea, the Norwegian Sea and in the Southern Barents Sea. The storage capacity in the depth interval 0.8 - 4 km below sea level is estimated to be ca. 13 Gt (13000000000 tonnes) CO 2 in geological traps (outside hydrocarbon fields), while the storage capacity in aquifers not confined to traps is estimated to be at least 280 Gt CO 2 . (Author)

  13. The possible evolution and future of CO2-concentrating mechanisms. (United States)

    Raven, John A; Beardall, John; Sánchez-Baracaldo, Patricia


    CO2-concentrating mechanisms (CCMs), based either on active transport of inorganic carbon (biophysical CCMs) or on biochemistry involving supplementary carbon fixation into C4 acids (C4 and CAM), play a major role in global primary productivity. However, the ubiquitous CO2-fixing enzyme in autotrophs, Rubisco, evolved at a time when atmospheric CO2 levels were very much higher than today and O2 was very low and, as CO2 and O2 approached (by no means monotonically), today's levels, at some time subsequently many organisms evolved a CCM that increased the supply of CO2 and decreased Rubisco oxygenase activity. Given that CO2 levels and other environmental factors have altered considerably between when autotrophs evolved and the present day, and are predicted to continue to change into the future, we here examine the drivers for, and possible timing of, evolution of CCMs. CCMs probably evolved when CO2 fell to 2-16 times the present atmospheric level, depending on Rubisco kinetics. We also assess the effects of other key environmental factors such as temperature and nutrient levels on CCM activity and examine the evidence for evolutionary changes in CCM activity and related cellular processes as well as limitations on continuity of CCMs through environmental variations. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email:

  14. Reducing CO2 from shipping – do non-CO2 effects matter?

    Directory of Open Access Journals (Sweden)

    M. S. Eide


    Full Text Available Shipping is a growing sector in the global economy, and it contributions to global CO2 emissions are expected to increase. CO2 emissions from the world shipping fleet will likely be regulated in the near future, and studies have shown that significant emission reductions can be achieved at low cost. Regulations are being discussed for both existing ships as well as for future additions to the fleet. In this study a plausible CO2 emission reduction inventory is constructed for the cargo fleet existing in 2010, as well as for container ships, bulk ships and tankers separately. In the reduction inventories, CO2 emissions are reduced by 25–32% relative to baseline by applying 15 technical and operational emission reduction measures in accordance with a ship-type-specific cost-effectiveness criterion, and 9 other emission compounds are changed as a technical implication of reducing CO2. The overall climate and environmental effects of the changes to all 10 emission components in the reduction inventory are assessed using a chemical transport model, radiative forcing (RF models and a simple climate model. We find substantial environmental and health benefits with up to 5% reduction in surface ozone levels, 15% reductions in surface sulfate and 10% reductions in wet deposition of sulfate in certain regions exposed to heavy ship traffic. The major ship types show distinctly different contributions in specific locations. For instance, the container fleet contributes 50% of the sulfate decline on the west coast of North America. The global radiative forcing from a 1 yr emission equal to the difference between baseline and reduction inventory shows an initial strong positive forcing from non-CO2 compounds. This warming effect is due to reduced cooling by aerosols and methane. After approximately 25 yr, the non-CO2 forcing is balanced by the CO2 forcing. For the global mean temperature change, we find a shift from warming to cooling after approximately 60

  15. Alberta industrial synergy CO2 programs initiative

    International Nuclear Information System (INIS)

    Yildirim, E.


    The various industrial sectors within Alberta produce about 350,000 tonnes of CO 2 per day. This presentation was concerned with how this large volume and high concentration of CO 2 can be used in industrial and agricultural applications, because every tonne of CO 2 used for such purposes is a tonne that does not end up in the atmosphere. There is a good potential for an industrial synergy between the producers and users of CO 2 . The Alberta Industrial Synergy CO 2 Programs Initiative was established to ultimately achieve a balance between the producers of CO 2 and the users of CO 2 by creating ways to use the massive quantities of CO 2 produced by Alberta's hydrocarbon-based economy. The Alberta CO 2 Research Steering Committee was created to initiate and support CO 2 programs such as: (1) CO 2 use in enhanced oil recovery, (2) creation of a CO 2 production inventory, (3) survey of CO 2 users and potential users, (4) investigation of process issues such as power generation, oil sands and cement manufacturing, and (5) biofixation by plants, (6) other disposal options (e.g. in depleted oil and gas reservoirs, in aquifers, in tailings ponds, in coal beds). The single most important challenge was identified as 'rationalizing the formation of the necessary infrastructure'. Failing to do that will greatly impede efforts directed towards CO 2 utilization

  16. CO2 emissions embodied in international trade: evidence for Spain

    International Nuclear Information System (INIS)

    Sanchez-Choliz, Julio; Duarte, Rosa


    The objective of this paper is to analyse the sectoral impacts that Spanish international trade relations have on present levels of atmospheric pollution using an input-output model. We try to evaluate the exports and imports of the Spanish economy in terms of the direct and indirect CO 2 emissions (CO 2 embodied) generated in Spain and abroad. The results show a slightly exporting behaviour in the Spanish economy which, nevertheless, hides important pollution interchanges. Moreover, the sectors transport material, mining and energy, non-metallic industries, chemical and metals are the most relevant CO 2 exporters and other services, construction, transport material and food the biggest CO 2 importers, and those whose final demands also embody more than 70% of the CO 2 emissions

  17. Enhancement of local air pollution by urban CO(2) domes. (United States)

    Jacobson, Mark Z


    Data suggest that domes of high CO(2) levels form over cities. Despite our knowledge of these domes for over a decade, no study has contemplated their effects on air pollution or health. In fact, all air pollution regulations worldwide assume arbitrarily that such domes have no local health impact, and carbon policy proposals, such as "cap and trade", implicitly assume that CO(2) impacts are the same regardless of where emissions occur. Here, it is found through data-evaluated numerical modeling with telescoping domains from the globe to the U.S., California, and Los Angeles, that local CO(2) emissions in isolation may increase local ozone and particulate matter. Although health impacts of such changes are uncertain, they are of concern, and it is estimated that that local CO(2) emissions may increase premature mortality by 50-100 and 300-1000/yr in California and the U.S., respectively. As such, reducing locally emitted CO(2) may reduce local air pollution mortality even if CO(2) in adjacent regions is not controlled. If correct, this result contradicts the basis for air pollution regulations worldwide, none of which considers controlling local CO(2) based on its local health impacts. It also suggests that a "cap and trade" policy should consider the location of CO(2) emissions, as the underlying assumption of the policy is incorrect.

  18. Atmospheric CO2 from fossil plant cuticles. (United States)

    Kerp, Hans


    Plants respond to changes in atmospheric carbon dioxide levels by regulating the number of stomata in their leaves. In his reconstruction of a continuous, 300-million-year record of atmospheric CO2, Retallack bases his curve on stomatal counts of fossil plant cuticles taken from published micrographs. However, the preservation of cuticles from Permian times is generally too fragmentary for the stomatal index to be reliably determined, the micrographs used could have biased the results, and there are important errors in the supplementary data - all of which cast doubt on the Permian part of Retallack's record.

  19. Spatial response of coastal marshes to increased atmospheric CO2


    Ratliff, Katherine M.; Braswell, Anna E.; Marani, Marco


    Coastal marshes provide numerous ecosystem services, are an important carbon sink, and are exposed to drowning as sea-level rise accelerates. Using a meta-analysis of the available observational data, we model the coupled marsh vegetation and morphological dynamics. We find that the fertilization effect of elevated atmospheric CO2 significantly increases marsh resilience to drowning and decreases the spatial extent of marsh retreat under high rates of sea-level rise. While this direct CO2 fer...

  20. CO2 Capture for Cement Technology

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar

    ppmvin 1960 to 390 ppmv in 2012, probably due to human activity. A lot of research is being carried out forreducing CO2emissions from large stationary sources. Ofwhich, the carbonate looping process is anew process and has the potential to reduce CO2emissions with lower energy penalties. Most of thework...... and the main parameter that controls the performance of the carbonator, a process model integrating the carbonate looping process with the cement pyro-process was simulated. The process simulation results indicate that the CO2 emission was only 0.07 kg/ kg cl, with an energy penalty of 2 MJ/kg CO2 captured......Production of cement is an energy intensive process and is the source of considerable CO2emissions. Itis estimated that the cement industry contributes around 8% of total global CO2emissions. CO2is oneof the major greenhouse gases. In the atmosphere, the CO2concentration has increased from 310...

  1. CO2 Virtual Science Data Environment API (United States)

    National Aeronautics and Space Administration — The CO2 Virtual Data Environment is a comprehensive effort at bringing together the models, data, and tools necessary to perform research on atmospheric CO2.This...

  2. ISLSCP II Globalview: Atmospheric CO2 Concentrations (United States)

    National Aeronautics and Space Administration — The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that were created...

  3. ISLSCP II Globalview: Atmospheric CO2 Concentrations (United States)

    National Aeronautics and Space Administration — ABSTRACT: The GlobalView Carbon Dioxide (CO2) data product contains synchronized and smoothed time series of atmospheric CO2 concentrations at selected sites that...

  4. Natural CO2 Releases Providing Messages For Stakeholders (United States)

    Dixon, T.; Romanak, K.; Camps, A. P.


    Stakeholder viewpoints and beliefs about geologic carbon storage are not always accurate, yet they may affect the future of carbon capture and storage (CCS). Gaps in stakeholder understanding and perspectives must be addressed, and natural systems that release CO2 can be valuable tools for communicating difficult scientific concepts because they provide tangible examples of geologic principles at work. Stakeholder perceptions commonly involve a misunderstanding of geologic scale and mechanisms, and can be charged with emotions fueled by media coverage of natural disasters. One example of an event widely cited by stakeholders is the CO2 release at Lake Nyos in Cameroon in August 1986 that killed 1700 people. This event is commonly thought by stakeholders to be an analogue for a release from a CO2 storage site; however, this release occurred under a rare combination of circumstances (a 208-m-deep volcanic crater lake) not analogous to an engineered CO2 storage site. Stakeholders therefore gravitate towards natural systems to form concepts and opinions of how CO2 might behave in a geological environment, but they often choose systems that are not true analogues but that gain attention through the media because they are associated with a disaster. When chosen correctly, natural releases of CO2 may create a level of clarity for stakeholders by providing tangible concrete examples that explain difficult scientific principles and provide familiar reference points to adapt different viewpoints. We present suggestions and examples presented by scientists at an IEAGHG Workshop Natural Releases of CO2: Building Knowledge for CO2 Storage Environmental Impact Assessments', held at Maria Laach, Germany, November 2010 which brought together researchers from the EU, North America, Japan, and Australia. It also included field observations of natural CO2 releases around the Laacher See caldera lake, CO2 springs, and the Wallenborn CO2 geyser. New information from international

  5. Does elevated CO2 alter silica uptake in trees? (United States)

    Fulweiler, Robinson W; Maguire, Timothy J; Carey, Joanna C; Finzi, Adrien C


    Human activities have greatly altered global carbon (C) and Nitrogen (N) cycling. In fact, atmospheric concentrations of carbon dioxide (CO2) have increased 40% over the last century and the amount of N cycling in the biosphere has more than doubled. In an effort to understand how plants will respond to continued global CO2 fertilization, long-term free-air CO2 enrichment experiments have been conducted at sites around the globe. Here we examine how atmospheric CO2 enrichment and N fertilization affects the uptake of silicon (Si) in the Duke Forest, North Carolina, a stand dominated by Pinus taeda (loblolly pine), and five hardwood species. Specifically, we measured foliar biogenic silica concentrations in five deciduous and one coniferous species across three treatments: CO2 enrichment, N enrichment, and N and CO2 enrichment. We found no consistent trends in foliar Si concentration under elevated CO2, N fertilization, or combined elevated CO2 and N fertilization. However, two-thirds of the tree species studied here have Si foliar concentrations greater than well-known Si accumulators, such as grasses. Based on net primary production values and aboveground Si concentrations in these trees, we calculated forest Si uptake rates under control and elevated CO2 concentrations. Due largely to increased primary production, elevated CO2 enhanced the magnitude of Si uptake between 20 and 26%, likely intensifying the terrestrial silica pump. This uptake of Si by forests has important implications for Si export from terrestrial systems, with the potential to impact C sequestration and higher trophic levels in downstream ecosystems.

  6. Environmental impacts of ocean disposal of CO2

    International Nuclear Information System (INIS)

    Adams, E.; Herzog, H.; Auerbach, D.


    One option to reduce atmospheric CO 2 levels is to capture and sequester power plant CO 2 Commercial CO 2 capture technology, though expensive, exists today. However, the ability to dispose of large quantities of CO 2 is highly uncertain. The deep ocean is one of only a few possible CO 2 disposal options (others are depleted oil and gas wells or deep, confined aquifers) and is a prime candidate because the deep ocean is vast and highly unsaturated in CO 2 . The term disposal is really a misnomer because the atmosphere and ocean eventually equilibrate on a timescale of 1000 years regardless of where the CO 2 is originally discharged. However, peak atmospheric CO 2 concentrations expected to occur in the next few centuries could be significantly reduced by ocean disposal. The magnitude of this reduction will depend upon the quantity of CO 2 injected in the ocean, as well as the depth and location of injection. Ocean disposal of CO 2 will only make sense if the environmental impacts to the ocean are significantly less than the avoided impacts of atmospheric release. Our project has been examining these ocean impacts through a multi-disciplinary effort designed to summarize the current state of knowledge. The end-product will be a report issued during the summer of 1996 consisting of two volumes an executive summary (Vol I) and a series of six, individually authored topical reports (Vol II). A workshop with invited participants from the U.S. and abroad will review the draft findings in January, 1996

  7. CO2 Emissions from Tropical Peat Soil Affected by Fertilization

    Directory of Open Access Journals (Sweden)



    Full Text Available The conversion of peatland to agricultural land uses has led to an increase of CO2 emission due to several factors, including fertilization. However, evidence on the effect of fertilization on CO2 emission from peat soils is rare and often inconsistence. We measured the effects of different types of fertilizer, including N, P and K sources, and clay as an ameliorant on CO2 emission from a bare peat soil in Lubuk Ogong, Riau Province. The fertilizers were added in the following combinations: 0 (unfertilized plot, N source (urea, slow-release N (slow-release urea, N and P sources (Urea+SP-36, N, P and K sources (urea+SP-36+KCl and combined NPK-Clay. The results showed that fertilization resulted in a decrease of CO2 emissions compared to that prior to fertilization except when slow-release urea was applied. The decreas of CO2 emissions was probably due to pH-related effects, because the pH in the N treatment was lower than that in both control and unfertilized plots. A decrease in the level of CO2 emissions among the treatments followed the order of NPK-Clay>NP>NPK>urea>slow-release urea. Covariance analysis showed that the difference in CO2 emissions prior to treatment was not significant. The application of individual and combined treatments of N, P, K and NPK mixed with 5 Mg ha-1 clay led to a significant reduce of CO2 emissions from bare peat soil. In addition to fertilization, the depth of water table significantly affected the CO2 emissions (P<0.05. We conclude that the application of nutrient combinations, including N, P, K and clay, could reduce CO2 emissions because the fertilizer and clay applications probably could maintain a balanced nutritional condition in the soil with respect to microbial activity.

  8. Bioelectrochemical conversion of CO2 to chemicals

    NARCIS (Netherlands)

    Bajracharya, Suman; Vanbroekhoven, Karolien; Buisman, Cees J.N.; Strik, David P.B.T.B.; Pant, Deepak


    The recent concept of microbial electrosynthesis (MES) has evolved as an electricity-driven production technology for chemicals from low-value carbon dioxide (CO2) using micro-organisms as biocatalysts. MES from CO2 comprises bioelectrochemical reduction of CO2 to multi-carbon organic compounds

  9. CO2 Permeability of Biological Membranes and Role of CO2 Channels (United States)

    Endeward, Volker; Arias-Hidalgo, Mariela; Al-Samir, Samer; Gros, Gerolf


    We summarize here, mainly for mammalian systems, the present knowledge of (a) the membrane CO2 permeabilities in various tissues; (b) the physiological significance of the value of the CO2 permeability; (c) the mechanisms by which membrane CO2 permeability is modulated; (d) the role of the intracellular diffusivity of CO2 for the quantitative significance of cell membrane CO2 permeability; (e) the available evidence for the existence of CO2 channels in mammalian and artificial systems, with a brief view on CO2 channels in fishes and plants; and, (f) the possible significance of CO2 channels in mammalian systems. PMID:29064458

  10. Forest succession at elevated CO2

    Energy Technology Data Exchange (ETDEWEB)

    Clark, James S.; Schlesinger, William H.


    We tested hypotheses concerning the response of forest succession to elevated CO2 in the FACTS-1 site at the Duke Forest. We quantified growth and survival of naturally recruited seedlings, tree saplings, vines, and shrubs under ambient and elevated CO2. We planted seeds and seedlings to augment sample sites. We augmented CO2 treatments with estimates of shade tolerance and nutrient limitation while controlling for soil and light effects to place CO2 treatments within the context of natural variability at the site. Results are now being analyzed and used to parameterize forest models of CO2 response.

  11. Quantifying CO2 Emissions From Individual Power Plants From Space (United States)

    Nassar, Ray; Hill, Timothy G.; McLinden, Chris A.; Wunch, Debra; Jones, Dylan B. A.; Crisp, David


    In order to better manage anthropogenic CO2 emissions, improved methods of quantifying emissions are needed at all spatial scales from the national level down to the facility level. Although the Orbiting Carbon Observatory 2 (OCO-2) satellite was not designed for monitoring power plant emissions, we show that in some cases, CO2 observations from OCO-2 can be used to quantify daily CO2 emissions from individual middle- to large-sized coal power plants by fitting the data to plume model simulations. Emission estimates for U.S. power plants are within 1-17% of reported daily emission values, enabling application of the approach to international sites that lack detailed emission information. This affirms that a constellation of future CO2 imaging satellites, optimized for point sources, could monitor emissions from individual power plants to support the implementation of climate policies.

  12. Performance of CO2 enrich CNG in direct injection engine (United States)

    Firmansyah, W. B.; Ayandotun, E. Z.; Zainal, A.; Aziz, A. R. A.; Heika, M. R.


    This paper investigates the potential of utilizing the undeveloped natural gas fields in Malaysia with high carbon dioxide (CO2) content ranging from 28% to 87%. For this experiment, various CO2 proportions by volume were added to pure natural gas as a way of simulating raw natural gas compositions in these fields. The experimental tests were carried out using a 4-stroke single cylinder spark ignition (SI) direct injection (DI) compressed natural gas (CNG) engine. The tests were carried out at 180° and 300° before top dead centre (BTDC) injection timing at 3000 rpm, to establish the effects on the engine performance. The results show that CO2 is suppressing the combustion of CNG while on the other hand CNG combustion is causing CO2 dissociation shown by decreasing CO2 emission with the increase in CO2 content. Results for 180° BTDC injection timing shows higher performance compared to 300° BTDC because of two possible reasons, higher volumetric efficiency and higher stratification level. The results also showed the possibility of increasing the CO2 content by injection strategy.

  13. The stomatal CO2 proxy does not saturate at high atmospheric CO2 concentrations: evidence from stomatal index responses of Araucariaceae conifers. (United States)

    Haworth, Matthew; Elliott-Kingston, Caroline; McElwain, Jennifer C


    The inverse relationship between the number of stomata on a leaf surface and the atmospheric carbon dioxide concentration ([CO(2)]) in which the leaf developed allows plants to optimise water-use efficiency (WUE), but it also permits the use of fossil plants as proxies of palaeoatmospheric [CO(2)]. The ancient conifer family Araucariaceae is often represented in fossil floras and may act as a suitable proxy of palaeo-[CO(2)], yet little is known regarding the stomatal index (SI) responses of extant Araucariaceae to [CO(2)]. Four Araucaria species (Araucaria columnaris, A. heterophylla, A. angustifolia and A. bidwillii) and Agathis australis displayed no significant relationship in SI to [CO(2)] below current ambient levels (~380 ppm). However, representatives of the three extant genera within the Araucariaceae (A. bidwillii, A. australis and Wollemia nobilis) all exhibited significant reductions in SI when grown in atmospheres of elevated [CO(2)] (1,500 ppm). Stomatal conductance was reduced and WUE increased when grown under elevated [CO(2)]. Stomatal pore length did not increase alongside reduced stomatal density (SD) and SI in the three araucariacean conifers when grown at elevated [CO(2)]. These pronounced SD and SI reductions occur at higher [CO(2)] levels than in other species with more recent evolutionary origins, and may reflect an evolutionary legacy of the Araucariaceae in the high [CO(2)] world of the Mesozoic Era. Araucariacean conifers may therefore be suitable stomatal proxies of palaeo-[CO(2)] during periods of "greenhouse" climates and high [CO(2)] in the Earth's history.

  14. Extraction of stevia glycosides with CO2 + water, CO2 + ethanol, and CO2 + water + ethanol

    Directory of Open Access Journals (Sweden)

    A. Pasquel


    Full Text Available Stevia leaves are an important source of natural sugar substitute. There are some restrictions on the use of stevia extract because of its distinctive aftertaste. Some authors attribute this to soluble material other than the stevia glycosides, even though it is well known that stevia glycosides have to some extent a bitter taste. Therefore, the purpose of this work was to develop a process to obtain stevia extract of a better quality. The proposed process includes two steps: i Pretreatment of the leaves by SCFE; ii Extraction of the stevia glycosides by SCFE using CO2 as solvent and water and/or ethanol as cosolvent. The mean total yield for SCFE pretreatment was 3.0%. The yields for SCFE with cosolvent of stevia glycosides were below 0.50%, except at 120 bar, 16°C, and 9.5% (molar of water. Under this condition, total yield was 3.4%. The quality of the glycosidic fraction with respect to its capacity as sweetener was better for the SCFE extract as compared to extract obtained by the conventional process. The overall extraction curves were well described by the Lack extended model.

  15. Does Elevated CO2 Alter Silica Uptake in Trees?

    Directory of Open Access Journals (Sweden)

    Robinson W. Fulweiler


    Full Text Available Human activities have greatly altered global carbon (C and N (N cycling. In fact, atmospheric concentrations of carbon dioxide (CO2 have increased 40% over the last century and the amount of N cycling in the biosphere has more than doubled. In an effort to understand how plants will respond to continued global carbon dioxide fertilization, long-term free-air CO2 enrichment (FACE experiments have been conducted at sites around the globe. Here we examine how atmospheric CO2 enrichment and N fertilization affects the uptake of silicon (Si in the Duke Forest, North Carolina, a stand dominated by Pinus taeda (loblolly pine, and five hardwood species. Specifically, we measured foliar biogenic silica (BSi concentrations in five deciduous and one coniferous species across three treatments: CO2 enrichment, N enrichment, and N and CO2 enrichment. We found no consistent trends in foliar Si concentration under elevated CO2, N fertilization, or combined elevated CO2 and N fertilization. However, two-thirds of the tree species studied here have Si foliar concentrations greater than well-known Si accumulators, such as grasses. Based on net primary production values and aboveground Si concentrations in these trees, we calculated forest Si uptake rates under control and elevated CO2 concentrations. Due largely to increased primary production, elevated CO2 enhanced the magnitude of Si uptake between 20% and 26%, likely intensifying the terrestrial silica pump. This uptake of Si by forests has important implications for Si export from terrestrial systems, with the potential to impact C sequestration and higher trophic levels in downstream ecosystems.

  16. CO2 Inhibits Respiration in Leaves of Rumex crispus L. 1 (United States)

    Amthor, Jeffrey S.; Koch, George W.; Bloom, Arnold J.


    Curly dock (Rumex crispus L.) was grown from seed in a glasshouse at an ambient CO2 partial pressure of about 35 pascals. Apparent respiration rate (CO2 efflux in the dark) of expanded leaves was then measured at ambient CO2 partial pressure of 5 to 95 pascals. Calculated intercellular CO2 partial pressure was proportional to ambient CO2 partial pressure in these short-term experiments. The CO2 level strongly affected apparent respiration rate: a doubling of the partial pressure of CO2 typically inhibited respiration by 25 to 30%, whereas a decrease in CO2 elicited a corresponding increase in respiration. These responses were readily reversible. A flexible, sensitive regulatory interaction between CO2 (a byproduct of respiration) and some component(s) of heterotrophic metabolism is indicated. PMID:16668707

  17. CO2 flux from Javanese mud volcanism (United States)

    Burton, M. R.; Arzilli, F.; Chiarugi, A.; Marliyani, G. I.; Anggara, F.; Harijoko, A.


    Abstract Studying the quantity and origin of CO2 emitted by back‐arc mud volcanoes is critical to correctly model fluid‐dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s−1 (117 t d−1) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d−1, comparable with the expected back‐arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man‐portable active remote sensing instruments for probing natural gas releases, enabling bottom‐up quantification of CO2 fluxes. PMID:28944134

  18. Modeling of CO2 storage in aquifers

    International Nuclear Information System (INIS)

    Savioli, Gabriela B; Santos, Juan E


    Storage of CO 2 in geological formations is a means of mitigating the greenhouse effect. Saline aquifers are a good alternative as storage sites due to their large volume and their common occurrence in nature. The first commercial CO 2 injection project is that of the Sleipner field in the Utsira Sand aquifer (North Sea). Nevertheless, very little was known about the effectiveness of CO 2 sequestration over very long periods of time. In this way, numerical modeling of CO 2 injection and seismic monitoring is an important tool to understand the behavior of CO 2 after injection and to make long term predictions in order to prevent CO 2 leaks from the storage into the atmosphere. The description of CO 2 injection into subsurface formations requires an accurate fluid-flow model. To simulate the simultaneous flow of brine and CO 2 we apply the Black-Oil formulation for two phase flow in porous media, which uses the PVT data as a simplified thermodynamic model. Seismic monitoring is modeled using Biot's equations of motion describing wave propagation in fluid-saturated poroviscoelastic solids. Numerical examples of CO 2 injection and time-lapse seismics using data of the Utsira formation show the capability of this methodology to monitor the migration and dispersal of CO 2 after injection.

  19. CO2 flux from Javanese mud volcanism (United States)

    Queißer, M.; Burton, M. R.; Arzilli, F.; Chiarugi, A.; Marliyani, G. I.; Anggara, F.; Harijoko, A.


    Studying the quantity and origin of CO2 emitted by back-arc mud volcanoes is critical to correctly model fluid-dynamical, thermodynamical, and geochemical processes that drive their activity and to constrain their role in the global geochemical carbon cycle. We measured CO2 fluxes of the Bledug Kuwu mud volcano on the Kendeng Fold and thrust belt in the back arc of Central Java, Indonesia, using scanning remote sensing absorption spectroscopy. The data show that the expelled gas is rich in CO2 with a volume fraction of at least 16 vol %. A lower limit CO2 flux of 1.4 kg s-1 (117 t d-1) was determined, in line with the CO2 flux from the Javanese mud volcano LUSI. Extrapolating these results to mud volcanism from the whole of Java suggests an order of magnitude total CO2 flux of 3 kt d-1, comparable with the expected back-arc efflux of magmatic CO2. After discussing geochemical, geological, and geophysical evidence we conclude that the source of CO2 observed at Bledug Kuwu is likely a mixture of thermogenic, biogenic, and magmatic CO2, with faulting controlling potential pathways for magmatic fluids. This study further demonstrates the merit of man-portable active remote sensing instruments for probing natural gas releases, enabling bottom-up quantification of CO2 fluxes.

  20. Porous Organic Polymers for CO2 Capture

    KAUST Repository

    Teng, Baiyang


    Carbon dioxide (CO2) has long been regarded as the major greenhouse gas, which leads to numerous negative effects on global environment. The capture and separation of CO2 by selective adsorption using porous materials proves to be an effective way to reduce the emission of CO2 to atmosphere. Porous organic polymers (POPs) are promising candidates for this application due to their readily tunable textual properties and surface functionalities. The objective of this thesis work is to develop new POPs with high CO2 adsorption capacities and CO2/N2 selectivities for post-combustion effluent (e.g. flue gas) treatment. We will also exploit the correlation between the CO2 capture performance of POPs and their textual properties/functionalities. Chapters Two focuses on the study of a group of porous phenolic-aldehyde polymers (PPAPs) synthesized by a catalyst-free method, the CO2 capture capacities of these PPAPs exceed 2.0 mmol/g at 298 K and 1 bar, while keeping CO2/N2 selectivity of more than 30 at the same time. Chapter Three reports the gas adsorption results of different hyper-cross-linked polymers (HCPs), which indicate that heterocyclo aromatic monomers can greatly enhance polymers’ CO2/N2 selectivities, and the N-H bond is proved to the active CO2 adsorption center in the N-contained (e.g. pyrrole) HCPs, which possess the highest selectivities of more than 40 at 273 K when compared with other HCPs. Chapter Four emphasizes on the chemical modification of a new designed polymer of intrinsic microporosity (PIM) with high CO2/N2 selectivity (50 at 273 K), whose experimental repeatability and chemical stability prove excellent. In Chapter Five, we demonstrate an improvement of both CO2 capture capacity and CO2/N2 selectivity by doping alkali metal ions into azo-polymers, which leads a promising method to the design of new porous organic polymers.

  1. Technological CO2 reduction potential for transport in CO2; Technologisch CO2-reductie potentieel voor transport in 2040

    Energy Technology Data Exchange (ETDEWEB)

    Passier, G.L.M.; Driever, J.P.M.; Van Baalen, J.; Foster, D.; Kadijk, G.; Verbeek, R.


    TNO conducted a study of the CO2 reduction potential in Dutch continental transport up to 2040. The main conclusion is that reduction of approximately 40% in CO2 emissions compared to 1990 is feasible by means of technological innovations and deployment of alternative energy sources. (mk) [Dutch] TNO heeft een studie uitgevoerd naar CO2-besparingsmogelijkheden in het Nederlandse continentaal vervoer tot het jaar 2040. De hoofdconclusie is dat een reductie van ca. 40% in de CO2-uitstoot ten opzichte van 1990 mogelijk is door middel van technologische innovaties en toepassing van alternatieve energiebronnen.

  2. Monitoring Atmospheric CO2 From Space: Challenge & Approach (United States)

    Lin, Bing; Harrison, F. Wallace; Nehrir, Amin; Browell, Edward; Dobler, Jeremy; Campbell, Joel; Meadows, Byron; Obland, Michael; Kooi, Susan; Fan, Tai-Fang; hide


    Exelis, Inc. As prototype space IPDA lidars, airborne laser absorption lidar systems operating in 1.57 CO2 absorption band have been developed and tested through lab, ground-based range, and flight campaigns. Very encouraging results have been obtained. The signal-to-noise ratio (SNR) for clear sky IPDA measurements of CO2 differential absorption optical depth (DAOD) for a 10-s integration over vegetated areas with about 10 km range was found to be as high as 1300, resulting in an error 0.077% or equivalent CO2 mixing ratio (XCO2) column precision of 0.3 ppm. Precise range measurements using the IM-CW lidar approach were also achieved, and the uncertainties have been shown to be at sub meter level. Based on the airborne lidar development, space lidar and atmospheric CO2 observations are simulated. It shows that with the IM-CW approach, accurate atmospheric CO2 measurements can be achieved from space, and a space mission such as that proposed by the DS will meet science goals of atmospheric CO2 monitoring.

  3. Different CO2 absorbents-modified SBA-15 sorbent for highly selective CO2 capture (United States)

    Liu, Xiuwu; Zhai, Xinru; Liu, Dongyang; Sun, Yan


    Different CO2 absorbents-modified SBA-15 materials are used as CO2 sorbent to improve the selectivity of CH4/CO2 separation. The SBA-15 sorbents modified by physical CO2 absorbents are very limited to increasing CO2 adsorption and present poor selectivity. However, the SBA-15 sorbents modified by chemical CO2 absorbents increase CO2 adsorption capacity obviously. The separation coefficients of CO2/CH4 increase in this case. The adsorption and regeneration properties of the SBA-15 sorbents modified by TEA, MDEA and DIPA have been compared. The SBA-15 modified by triethanolamine (TEA) presents better CO2/CH4 separation performance than the materials modified by other CO2 absorbents.

  4. Energyless CO2 Absorption, Generation, and Fixation Using Atmospheric CO2. (United States)

    Inagaki, Fuyuhiko; Okada, Yasuhiko; Matsumoto, Chiaki; Yamada, Masayuki; Nakazawa, Kenta; Mukai, Chisato


    From an economic and ecological perspective, the efficient utilization of atmospheric CO2 as a carbon resource should be a much more important goal than reducing CO2 emissions. However, no strategy to harvest CO2 using atmospheric CO2 at room temperature currently exists, which is presumably due to the extremely low concentration of CO2 in ambient air (approximately 400 ppm=0.04 vol%). We discovered that monoethanolamine (MEA) and its derivatives efficiently absorbed atmospheric CO2 without requiring an energy source. We also found that the absorbed CO2 could be easily liberated with acid. Furthermore, a novel CO2 generator enabled us to synthesize a high value-added material (i.e., 2-oxazolidinone derivatives based on the metal catalyzed CO2-fixation at room temperature) from atmospheric CO2.

  5. Elevated CO2 as a driver of global dryland greening

    KAUST Repository

    Lu, Xuefei


    While recent findings based on satellite records indicate a positive trend in vegetation greenness over global drylands, the reasons remain elusive. We hypothesize that enhanced levels of atmospheric CO2 play an important role in the observed greening through the CO2 effect on plant water savings and consequent available soil water increases. Meta-analytic techniques were used to compare soil water content under ambient and elevated CO2 treatments across a range of climate regimes, vegetation types, soil textures and land management practices. Based on 1705 field measurements from 21 distinct sites, a consistent and statistically significant increase in the availability of soil water (11%) was observed under elevated CO2 treatments in both drylands and non-drylands, with a statistically stronger response over drylands (17% vs. 9%). Given the inherent water limitation in drylands, it is suggested that the additional soil water availability is a likely driver of observed increases in vegetation greenness.

  6. Toward solar biodiesel production from CO2 using engineered cyanobacteria. (United States)

    Woo, Han Min; Lee, Hyun Jeong


    Metabolic engineering of cyanobacteria has received attention as a sustainable strategy to convert carbon dioxide to various biochemicals including fatty acid-derived biodiesel. Recently, Synechococcus elongatus PCC 7942, a model cyanobacterium, has been engineered to convert CO2 to fatty acid ethyl esters (FAEEs) as biodiesel. Modular pathway has been constructed for FAEE production. Several metabolic engineering strategies were discussed to improve the production levels of FAEEs, including host engineering by improving CO2 fixation rate and photosynthetic efficiency. In addition, protein engineering of key enzyme in S. elongatus PCC 7942 was implemented to address issues on FAEE secretions toward sustainable FAEE production from CO2. Finally, advanced metabolic engineering will promote developing biosolar cell factories to convert CO2 to feasible amount of FAEEs toward solar biodiesel. © FEMS 2017. All rights reserved. For permissions, please e-mail:

  7. Global CO2 Emission from Volcanic Lakes (United States)

    Perez, N.; Hernandez Perez, P. A.; Padilla, G.; Melian Rodriguez, G.; Padron, E.; Barrancos, J.; Calvo, D.; Kusukabe, M.; Mori, T.; Nolasco, D.


    During the last two decades, scientists have paid attention to CO2 volcanic emissions and its contribution to the global C budget. Excluding MORBs as a net source of CO2 to the atmosphere, the global CO2 discharge from subaerial volcanism has been estimated about 300 Mt y-1 and this rate accounts for both visible (plume & fumaroles) and non-visible (diffuse) volcanic gas emanations (Mörner & Etíope, 2002). However, CO2 emissions from volcanic lakes have not been considered to estimate the global CO2 discharge from subaerial volcanoes. In order to improve this global CO2 emission rate and estimate the global CO2 emission from volcanic lakes, an extensive research on CO2 emission of volcanic lakes from Phillipines, Nicaragua, Guatemala, Mexico, Indonesia, Germany, France, Cameroon, Costa Rica, El Salvador and Ecuador had been recently carried out. In-situ measurements of CO2 efflux from the surface environment of volcanic lakes were performed by means of a modified floating device of the accumulation chamber method. To quantify the total CO2 emission from each volcanic lake, CO2 efflux maps were constructed using sequential Gaussian simulations (sGs). CO2 emission rates were normalized by the lake area (km2), and volcanic lakes were grouped following classification in acid, alkaline and neutral lakes. The observed average normalized CO2 emission rate values increase from alkaline (5.5 t km-2 d-1), neutral (210.0 t km-2 d-1), to acid (676.8 t km-2 d-1) volcanic lakes. Taking into account (i) these normalized CO2 emission rates from 31 volcanic lakes, (ii) the number of volcanic lakes in the world (~ 1100), (iii) the fraction of the investigated alkaline (45%), neutral (39%), and acid (16%) volcanic lakes, and (iv) the average areas of the investigated alkaline (36,8 km2), neutral (3,7 km2), and acid (0,5 km2) volcanic lakes; the global CO2 emission from volcanic lakes is about ~ 182 Mt year-1. This estimated value is about ~ 50% of the actual estimated global CO2

  8. Shifting terrestrial feedbacks from CO2 fertilization to global warming (United States)

    Peñuelas, Josep; Ciais, Philippe; Janssens, Ivan; Canadell, Josep; Obersteiner, Michael; Piao, Shilong; Vautard, Robert; Sardans Jordi Sardans, Jordi


    Humans are increasingly fertilizing the planet. Our activities are increasing atmospheric concentrations of carbon dioxide, nitrogen inputs to ecosystems and global temperatures. Individually and combined, they lead to biospheric availability of carbon and nitrogen, enhanced metabolic activity, and longer growing seasons. Plants can consequently grow more and take up more carbon that can be stored in ecosystem carbon pools, thus enhancing carbon sinks for atmospheric CO2. Data on the increased strength of carbon sinks are, however, inconclusive: Some data (eddy covariance, short-term experiments on elevated CO2 and nutrient fertilization) suggest that biospheric carbon uptake is already effectively increasing but some other data suggest it is not, or are not general and conclusive (tree-ring, forest inventory). The combined land-ocean CO2 sink flux per unit of excess atmospheric CO2 above preindustrial levels declined over 1959-2012 by a factor of about 1/3, implying that CO2 sinks increased more slowly than excess CO2. We will discuss the available data, and the discussion will drive us to revisit our projections for enhanced carbon sinks. We will reconsider the performance of the modulators of increased carbon uptake in a CO2 fertilized and warmed world: nutrients, climate, land use and pollution. Nutrient availability in particular plays a crucial role. A simple mass-balance approach indicates that limited phosphorus availability and the corresponding N:P imbalances can jointly reduce the projected future carbon storage by natural ecosystems during this century. We then present a new paradigm: we are shifting from a fertilization to a warming era. Compared to the historical period, future impacts of warming will be larger than the benefits of CO2 fertilization given nutrient limitations, management and disturbance (which reduces C stocks and thus sequestration potential) and because CO2 will decrease by 2050 in RCP2.6, meaning loss of CO2 fertilization, and CO2

  9. Metal-Organic Framework-Stabilized CO2/Water Interfacial Route for Photocatalytic CO2Conversion. (United States)

    Luo, Tian; Zhang, Jianling; Li, Wei; He, Zhenhong; Sun, Xiaofu; Shi, Jinbiao; Shao, Dan; Zhang, Bingxing; Tan, Xiuniang; Han, Buxing


    Here, we propose a CO 2 /water interfacial route for photocatalytic CO 2 conversion by utilizing a metal-organic framework (MOF) as both an emulsifier and a catalyst. The CO 2 reduction occurring at the CO 2 /water interface produces formate with remarkably enhanced efficiency as compared with that in conventional solvent. The route is efficient, facile, adjustable, and environmentally benign, which is applicable for the CO 2 transformation photocatalyzed by different kinds of MOFs.

  10. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll


    The cement industry is one of the major sources of CO2 emissions and is likely to contribute to further increases in the near future. The carbonate looping process has the potential to capture CO2 emissions from the cement industry, in which raw meal for cement production could be used...... as the sorbent. Cyclic experiments were carried out in a TGA apparatus using industrial cement raw meal and synthetic raw meal as sorbents, with limestone as the reference. The results show that the CO2 capture capacities of the cement raw meal and the synthetic raw meal are comparable to those of pure limestone....... The CO2 capture capacity of limestone in the raw meal is lower than for pure limestone. The difference in the CO2 capture capacity decreases with an increase in cycle number. The calcination conditions and composition are major factors that influence the CO2 capture capacity of limestone. At 850 °C in N2...

  11. Advanced technology development reducing CO2 emissions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sup


    Responding to Korean government policies on green growth and global energy/ environmental challenges, SK energy has been developing new technologies to reduce CO2 emissions by 1) CO2 capture and utilization, 2) efficiency improvement, and 3) Li-ion batteries. The paper introduces three advanced technologies developed by SK energy; GreenPol, ACO, and Li-ion battery. Contributing to company vision, a more energy and less CO2, the three technologies are characterized as follows. GreenPol utilizes CO2 as a feedstock for making polymer. Advanced Catalytic Olefin (ACO) reduces CO2 emission by 20% and increase olefin production by 17%. Li-ion Batteries for automotive industries improves CO2 emission.

  12. Public Acceptance for Geological CO2-Storage (United States)

    Schilling, F.; Ossing, F.; Würdemann, H.; Co2SINK Team


    Public acceptance is one of the fundamental prerequisites for geological CO2 storage. In highly populated areas like central Europe, especially in the vicinity of metropolitan areas like Berlin, underground operations are in the focus of the people living next to the site, the media, and politics. To gain acceptance, all these groups - the people in the neighbourhood, journalists, and authorities - need to be confident of the security of the planned storage operation as well as the long term security of storage. A very important point is to show that the technical risks of CO2 storage can be managed with the help of a proper short and long term monitoring concept, as well as appropriate mitigation technologies e.g adequate abandonment procedures for leaking wells. To better explain the possible risks examples for leakage scenarios help the public to assess and to accept the technical risks of CO2 storage. At Ketzin we tried the following approach that can be summed up on the basis: Always tell the truth! This might be self-evident but it has to be stressed that credibility is of vital importance. Suspiciousness and distrust are best friends of fear. Undefined fear seems to be the major risk in public acceptance of geological CO2-storage. Misinformation and missing communication further enhance the denial of geological CO2 storage. When we started to plan and establish the Ketzin storage site, we ensured a forward directed communication. Offensive information activities, an information centre on site, active media politics and open information about the activities taking place are basics. Some of the measures were: - information of the competent authorities through meetings (mayor, governmental authorities) - information of the local public, e.g. hearings (while also inviting local, regional and nation wide media) - we always treated the local people and press first! - organizing of bigger events to inform the public on site, e.g. start of drilling activities (open

  13. CO2 sequestration: Storage capacity guideline needed (United States)

    Frailey, S.M.; Finley, R.J.; Hickman, T.S.


    Petroleum reserves are classified for the assessment of available supplies by governmental agencies, management of business processes for achieving exploration and production efficiency, and documentation of the value of reserves and resources in financial statements. Up to the present however, the storage capacity determinations made by some organizations in the initial CO2 resource assessment are incorrect technically. New publications should thus cover differences in mineral adsorption of CO2 and dissolution of CO2 in various brine waters.

  14. CO2 Allowance and Electricity Price Interaction

    Energy Technology Data Exchange (ETDEWEB)



    With the introduction of CO2 emission constraints on power generators in the European Union, climate policy is starting to have notable effects on energy markets. This paper sheds light on the links between CO2 prices, electricity prices, and electricity costs to industry. It is based on a series of interviews with industrial and electricity stakeholders, as well as a rich literature seeking to estimate the exact effect of CO2 prices on electricity prices.

  15. CO2 capture in different carbon materials. (United States)

    Jiménez, Vicente; Ramírez-Lucas, Ana; Díaz, José Antonio; Sánchez, Paula; Romero, Amaya


    In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.

  16. Synthetic biology for CO2fixation. (United States)

    Gong, Fuyu; Cai, Zhen; Li, Yin


    Recycling of carbon dioxide (CO 2 ) into fuels and chemicals is a potential approach to reduce CO 2 emission and fossil-fuel consumption. Autotrophic microbes can utilize energy from light, hydrogen, or sulfur to assimilate atmospheric CO 2 into organic compounds at ambient temperature and pressure. This provides a feasible way for biological production of fuels and chemicals from CO 2 under normal conditions. Recently great progress has been made in this research area, and dozens of CO 2 -derived fuels and chemicals have been reported to be synthesized by autotrophic microbes. This is accompanied by investigations into natural CO 2 -fixation pathways and the rapid development of new technologies in synthetic biology. This review first summarizes the six natural CO 2 -fixation pathways reported to date, followed by an overview of recent progress in the design and engineering of CO 2 -fixation pathways as well as energy supply patterns using the concept and tools of synthetic biology. Finally, we will discuss future prospects in biological fixation of CO 2 .

  17. Development of a three-man preprototype CO2 collection subsystem for spacecraft application (United States)

    Schubert, F. H.; Wynveen, R. A.; Quattrone, P. D.; Marshall, R. D.


    Future long-duration manned space missions will require regenerable carbon dioxide (CO2) collection concepts such as the Electrochemical Depolarized CO2 Concentrator (EDC). A three-man-capacity preprototype CO2 Collection Subsystem (CS-3) is being developed for eventual flight demonstration as part of the Air Revitalization System (ARS) of the Regenerative Life Support Evaluation (RLSE) experiment. The CS-3 employs an EDC to concentrate CO2 from the low partial-pressure levels required of spacecraft atmospheres to high partial-pressure levels needed for oxygen (O2) recovery through CO2 reduction processes. The CS-3 is sized to remove a nominal 3.0 kg/day (6.6 lb/day) of the CO2 to maintain the CO2 partial pressure (pCO2) of the cabin atmosphere at 400 Pa (3 mm Hg) or less. This paper presents the preprototype design, configuration, operation, and projected performance characteristics.


    Directory of Open Access Journals (Sweden)

    Dewi Lastuti,


    Full Text Available ABSTRACT: A microcosmic experiment was conducted to estimate CO2 emission from peat soils. Two treatments, peat humification levels (F = Fibric, H = Hemic, S = Sapric and water levels (G0 = 10 cm; G1= 0 cm; G2 = -10 cm; G3 = -20 cm, were tested and arranged according to factorial randomized complete block design (RCBD with 3 replicates. Current study revealed that CO2 emission was significantly affected (p<0.01 by peat humification levels and water levels. The sapric peat emitted significantly higher CO2 (696.69 b ± 43.95 mg CO2 g-1 peat d-1 than hemic (504.62 a ± 105.72 mg CO2 g-1 peat d-1and fibric (492.56 a ± 90.69 mg CO2 g-1 peat d-1peats. Decreases in water level shifted anaerobic condition into aerobic condition, causing significant increases in CO2 emission. Regardless of peat humification levels, CO2 emission and water table depth in current study showed a nonlinier relationship. It seems that a threshold water tables for enhanced CO2 emissions was within the range of -10 to -20 cm below peat surface. Keywords : microcosmic, peat, humification, CO2 emission. ABSTRAK (Indonesian: Tujuan percobaan skala mikrokosm ini adalah untuk estimasi emisi CO2 dari tanah gambut. Pengaruh 2 (dua perlakuan, yaitu tingkat humifikasi gambut (F = Fibrik, H = Hemik, S = Saprik dan tinggi muka air (G0 = 10 cm; G1= 0 cm; G2 = -10 cm; G3 = -20 cm, disusun menurut Rancangan Acak Lengkap Faktorial (RALF dengan 3 (tiga ulangan. Hasil penelitian menunjukkan bahwa perlakuan tingkat humifikasi gambut dan tinggi muka air mempengaruhi emisi CO2 secara nyata (p<0.01. Emisi CO2 dari gambut dengan tingkat humifikasi saprik menghasilkan emisi CO2 secara nyata lebih tinggi (696.69 b ± 43.95 mg CO2 g-1 gambut hr-1 dibandingkan dengan emisi CO2 dari gambut hemik (504.62 a ± 105.72 mg CO2 g-1 gambut hr-1 dan fibrik (492.56 a ± 90.69 mg CO2 g-1 gambut hr-1. Penelitian ini juga menunjukkan bahwa perubahan suasana reduktif menjadi oksifatif akibat penurunan muka air juga

  19. Impacts of chemical crop protection applications on related CO(2) emissions and CO(2) assimilation of crops. (United States)

    Kern, Manfred; Noleppa, Steffen; Schwarz, Gerald


    A major global challenge is to provide agricultural production systems that are able to sustain growing demands for food, feed, fibre and renewable raw materials without exacerbating climate change. Detailed and reliable data on the CO(2) balance of different agricultural management activities and inputs as a basis to quantify carbon footprints of agriculture are still lacking. This study aims to fill this gap further by quantifying the net balance of emitted and assimilated CO(2) due to the application of crop protection treatments on the farm, and by assessing their partial contribution to GHG emissions and mitigation in agriculture. The study focuses on key agricultural crops including wheat, corn, oilseeds and sugar crops. The final CO(2) balance, considering GHG emissions due to on-farm CPP treatment in comparison with CO(2) storage in additional biomass, CO(2) protected with respect to agrotechnical inputs and land inputs and CO(2) saved with respect to associated global land use changes, is positive and may reach multiples of up to nearly 2000. The results highlight the importance of the positive yield effects of the CPP programme applications on the farm, resulting in additional assimilated biomass at the farm level and less land use changes at the global level, and thus lower pressure on environmentally important indicators of overall agricultural sustainability. Copyright © 2012 Society of Chemical Industry.

  20. Mixing ratio and species affect the use of substrate-derived CO2 by Sphagnum

    NARCIS (Netherlands)

    Limpens, J.; Robroek, B.J.M.; Heijmans, M.M.P.D.; Tomassen, H.B.M.


    Question: Can mixing ratio and species affect the use of substrate-derived CO2 by Sphagnum? Location: Poor fen in south Sweden and greenhouse in Wageningen, The Netherlands. Methods: Two mixing ratios of Sphagnum cuspidatum and S. magellanicum were exposed to two levels of CO2 by pumping CO2

  1. Experimental Ion Mobility measurements in Ne-CO$_2$ and CO$_2$-N$_2$ mixtures

    CERN Document Server

    Encarnação, P.M.C.C.; Veenhof, R.; Neves, P.N.B.; Santos, F.P.; Trindade, A.M.F.; Borges, F.I.G.M.; Conde, C.A.N.


    In this paper we present the experimental results for the mobility, K0, of ions in neon-carbon dioxide (Ne-CO2) and carbon dioxide-nitrogen (CO2-N2) gaseous mixtures for total pressures ranging from 8–12 Torr, reduced electric fields in the 10–25 Td range, at room temperature. Regarding the Ne-CO2 mixture only one peak was observed for CO2 concentrations above 25%, which has been identified as an ion originated in CO2, while below 25% of CO2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 ± 0.05 and 1.07 ± 0.01 cm2V−1s−1 in the 10%-99% interval of CO2, and from 4.61 ± 0.19 to 3.00 ± 0.09 cm2V−1s−1 for the second peak observed (10%–25% of CO2). For the CO2-N2, the time-of-arrival spectra displayed only one peak for CO2 concentrations above 10%, which was attributed to ions originated in CO2, namely CO2+(CO2), with a second peak appearing for CO2 concentrations below 10%. This secon...

  2. Energy efficiency and CO2 emissions in Swedish manufacturing industries

    Energy Technology Data Exchange (ETDEWEB)

    Pardo Martinez, C.I. [Faculty of Environmental Engineering, University of La Salle, Bogota (Colombia); Silveira, S [Energy and Climate Studies, Department of Energy Technology, KTH, Stockholm (Sweden)


    This paper analyses the trends in energy consumption and CO2 emissions as a result of energy efficiency improvements in Swedish manufacturing industries between 1993 and 2008. Using data at the two-digit level, the performance of this sector is studied in terms of CO2 emissions, energy consumption, energy efficiency measured as energy intensity, value of production, fuel sources, energy prices and energy taxes. It was found that energy consumption, energy intensity and CO2 emission intensity, measured as production values, have decreased significantly in the Swedish manufacturing industries during the period studied. The results of the decomposition analysis show that output growth has not required higher energy consumption, leading to a reduction in both energy and CO2 emission intensities. The role of structural changes has been minor, and the trends of energy efficiency and CO2 emissions have been similar during the sample period. A stochastic frontier model was used to determine possible factors that may have influenced these trends. The results demonstrate that high energy prices, energy taxes, investments and electricity consumption have influenced the reduction of energy and CO2 emission intensities, indicating that Sweden has applied an adequate and effective energy policy. The study confirms that it is possible to achieve economic growth and sustainable development whilst also reducing the pressure on resources and energy consumption and promoting the shift towards a low-carbon economy.

  3. CO Diffusion and Desorption Kinetics in CO2 Ices (United States)

    Cooke, Ilsa R.; Öberg, Karin I.; Fayolle, Edith C.; Peeler, Zoe; Bergner, Jennifer B.


    The diffusion of species in icy dust grain mantles is a fundamental process that shapes the chemistry of interstellar regions; yet, measurements of diffusion in interstellar ice analogs are scarce. Here we present measurements of CO diffusion into CO2 ice at low temperatures (T = 11–23 K) using CO2 longitudinal optical phonon modes to monitor the level of mixing of initially layered ices. We model the diffusion kinetics using Fick’s second law and find that the temperature-dependent diffusion coefficients are well fit by an Arrhenius equation, giving a diffusion barrier of 300 ± 40 K. The low barrier along with the diffusion kinetics through isotopically labeled layers suggest that CO diffuses through CO2 along pore surfaces rather than through bulk diffusion. In complementary experiments, we measure the desorption energy of CO from CO2 ices deposited at 11–50 K by temperature programmed desorption and find that the desorption barrier ranges from 1240 ± 90 K to 1410 ± 70 K depending on the CO2 deposition temperature and resultant ice porosity. The measured CO–CO2 desorption barriers demonstrate that CO binds equally well to CO2 and H2O ices when both are compact. The CO–CO2 diffusion–desorption barrier ratio ranges from 0.21 to 0.24 dependent on the binding environment during diffusion. The diffusion–desorption ratio is consistent with the above hypothesis that the observed diffusion is a surface process and adds to previous experimental evidence on diffusion in water ice that suggests surface diffusion is important to the mobility of molecules within interstellar ices.

  4. Diffuse soil CO_2 degassing from Linosa island

    Directory of Open Access Journals (Sweden)

    Dario Cellura


    Full Text Available Normal 0 14 false false false MicrosoftInternetExplorer4 Normal 0 14 false false false IT X-NONE X-NONE MicrosoftInternetExplorer4 Herein, we present and discuss the result of 148 measurements of soil CO2 flux performed for the first time in Linosa island (Sicily Channel, Italy, a Plio-Pleistocene volcanic complex no longer active but still of interest owing to its location within a seismically active portion of the Sicily Channel rift system. The main purpose of this survey was to assess the occurrence of CO2 soil degassing, and compare flux estimations from this island with data of soil degassing from worldwide active volcanic as well as non-volcanic areas. To this aim soil CO2 fluxes were measured over a surface of about 4.2 km2 covering ~80% of the island. The soil CO2 degassing was observed to be mainly concentrated in the eastern part of the island likely due to volcano-tectonic lineaments, the presence of which is in good agreement with the known predominant regional faults system. Then, the collected data were interpreted using sequential Gaussian simulation that allowed estimating the total CO2 emissions of the island. Results show low levels of CO2 emissions from the soil of the island (~55 ton d-1 compared with CO2 emissions of currently active volcanic areas, such as Miyakejima (Japan and Vulcano (Italy. Results from this study suggest that soil degassing in Linosa is mainly fed by superficial organic activity with a moderate contribution of a deep CO2 likely driven by NW-SE trending active tectonic structures in the eastern part of the island.

  5. Seasonal Variations of Surface fCO2 and Sea-Air CO2 Fluxes in the Ulleung Basin of the East/Japan Sea

    Directory of Open Access Journals (Sweden)

    Sang-Hwa Choi


    Full Text Available Temperature, salinity, chlorophyll a, and surface CO2 fugacity (fCO2 were extensively investigated in the Ulleung Basin of the East/Japan Sea during four seasonal cruises. In spring, surface fCO2 showed large variations ranging from 260 to 356 £gatm, which were considerably lower than the atmospheric CO2 levels. Surface fCO2 was highest (316 to 409 £gatm in summer. The central part of the study area was undersaturated with respect to atmospheric CO2, while the coastal and easternmost regions were oversaturated. In autumn, the entire study area was fairly undersaturated with respect to atmospheric CO2. In winter, surface fCO2 ranged from 303 to 371 £gatm, similar to that in autumn, despite the much lower sea surface temperature. The seasonal variation in surface fCO2 could not be explained solely by seasonal changes in sea surface temperature and salinity. The vertical mixing, lateral transport, and sea-air CO2 exchange considerably influenced the seasonal variation in surface fCO2. The Ulleung Basin of the East/Japan Sea was a sink of atmospheric CO2 in spring, autumn, and winter, but a weak source of CO2 to the atmosphere in summer. The annual integrated sea-air CO2 flux in the Ulleung Basin of the East/Japan Sea was -2.47 ± 1.26 mol m-2 yr-1, quite similar to a previous estimate (-2.2 mol m-2 yr-1 in the south East/Japan Sea. This indicates that the Ulleung Basin of the East/Japan Sea acts as a strong sink of atmospheric CO2.

  6. CO2-Brine Displacement in Geological CO2 Sequestration: Microfluidic Flow Model Study (United States)

    Cao, S. C.; Jung, J.


    Geological CO2 sequestration is a promising method to reduce atmospheric CO2 and deep saline aquifers is one of the most important options due to their capacity for CO2 storage. Thus, a better understanding of two immiscible brine-CO2 mobility and its saturation, including invading patterns in deep saline aquifers as CO2 storage sites is required. Lenormand (1990) explored the invading patterns of two immiscible fluids in porous media with a transition region and three dominant regions: capillary fingering, viscous fingering, and stable displacement. These are determined by two main aspect ratios Nm and Nc through experimental studies using micromodel. Micromodel provides the opportunity to discover unrecognized processes, and test existing theories and assumptions in fluid flow through porous media. In this study, the micromodel was used to explore the effects of the scCO2 injecting velocity and ionic strength on invading patterns in geological CO2 sequestration. When scCO2 was injected into the micromodel that has already saturated with brine, the brine in the micromodel was displaced by injected scCO2. Continuous scCO2 injection into the micromodel leaded the scCO2 to pass through the micromodel. And the scCO2-brine displacement distribution in the micromodel remained constant during additional 100 PV scCO2 injection after injecting scCO2 passed through micromodel. When scCO2 passed through the porous media, the scCO2-brine displacement distribution represented the maximum displacement ratio. Results showed that scCO2-brine displacement ratios increased with: elevated pressures in the range of 3MPa~8MPa, decreased ionic strength from 5M to 1M NaCl, and increased scCO2 injecting velocity up to 40 μL/min. Also, Nm and Nc obtained in this study are located in transition region of the invading patterns suggested by Lenormand (1990).

  7. Agroecosystem productivity in a warmer and CO2 enriched atmosphere (United States)

    Bernacchi, Carl; Köhler, Iris; Ort, Donald; Long, Steven; Clemente, Thomas


    A number of in-field manipulative experiments have been conducted that address the response of key ecosystem services of major agronomic species to rising CO2. Global warming, however, is inextricably linked to rising greenhouse gases in general, of which CO2 is the most dominant. Therefore, agroecosystem functioning in future conditions requires an understanding of plant responses to both rising CO2 and increased temperatures. Few in-field manipulative experiments have been conducted that supplement both heating and CO2 above background concentrations. Here, the results of six years of experimentation using a coupled Free Air CO2 Enrichment (FACE) technology with variable output infrared heating arrays are reported. The manipulative experiment increased temperatures (+ 3.5˚ C) and CO2 (+ 200 μmol mol-1) above background levels for on two major agronomic crop species grown throughout the world, Zea mays (maize) and Glycine max (soybean). The first phase of this research addresses the response of plant physiological parameters to growth in elevated CO2 and warmer temperatures for maize and soybean grown in an open-air manipulative experiment. The results show that any increase in ecosystem productivity associated with rising CO2 is either similar or is offset by growth at higher temperatures, inconsistent with the perceived benefits of higher CO2 plus warmer temperatures on agroecosystem productivity. The second phase of this research addresses the opportunity to genetically modify soybean to allow for improved productivity under high CO2 and warmer temperatures by increasing a key photosynthetic carbon reduction cycle enzyme, SPBase. The results from this research demonstrates that manipulation of the photosynthetic pathway can lead to higher productivity in high CO2 and temperature relative to the wild-type control soybean. Overall, this research advances the understanding of the physiological responses of two major crops, and the impact on ecosystem services

  8. Growth strategy of Norway spruce under air elevated [CO2 (United States)

    Pokorny, R.; Urban, O.; Holisova, P.; Sprtova, M.; Sigut, L.; Slipkova, R.


    Plants will respond to globally increasing atmospheric CO2 concentration ([CO2]) by acclimation or adaptation at physiological and morphological levels. Considering the temporal onset, physiological responses may be categorized as short-term and morphological ones as long-term responses. The degree of plant growth responses, including cell division and cell expansion, is highly variable. It depends mainly on the specie's genetic predisposition, environment, mineral nutrition status, duration of CO2 enrichment, and/or synergetic effects of other stresses. Elevated [CO2] causes changes in tissue anatomy, quantity, size, shape and spatial orientation and can result in altered sink strength. Since, there are many experimental facilities for the investigation of elevated [CO2] effects on trees: i) closed systems or open top chambers (OTCs), ii) semi-open systems (for example glass domes with adjustable lamella windows - DAWs), and iii) free-air [CO2] enrichments (FACE); the results are still unsatisfactory due to: i) relatively short-term duration of experiments, ii) cultivation of young plants with different growth strategy comparing to old ones, iii) plant cultivation under artificial soil and weather conditions, and iv) in non-representative stand structure. In this contribution we are discussing the physiological and morphological responses of Norway spruce trees cultivated in DAWs during eight consecutive growing seasons in the context with other results from Norway spruce cultivation under air-elevated [CO2] conditions. On the level of physiological responses, we discuss the changes in the rate of CO2 assimilation, assimilation capacity, photorespiration, dark respiration, stomatal conductance, water potential and transpiration, and the sensitivity of these physiological processes to temperature. On the level of morphological responses, we discuss the changes in bud and growth phenology, needle and shoot morphology, architecture of crown and root system, wood

  9. Membrane Technologies for CO2 Capture

    NARCIS (Netherlands)

    Simons-Fischbein, K.


    This thesis investigates the potential of membrane technology for the effective CO2/CH4 separation. The work focuses on two different membrane processes to accomplish the separation: 1) The use of a gas-liquid membrane contactor for the selective absorption of CO2 from CH4 2) The use of thin, dense

  10. Recent development of capture of CO2

    CERN Document Server

    Chavez, Rosa Hilda


    "Recent Technologies in the capture of CO2" provides a comprehensive summary on the latest technologies available to minimize the emission of CO2 from large point sources like fossil-fuel power plants or industrial facilities. This ebook also covers various techniques that could be developed to reduce the amount of CO2 released into the atmosphere. The contents of this book include chapters on oxy-fuel combustion in fluidized beds, gas separation membrane used in post-combustion capture, minimizing energy consumption in CO2 capture processes through process integration, characterization and application of structured packing for CO2 capture, calcium looping technology for CO2 capture and many more. Recent Technologies in capture of CO2 is a valuable resource for graduate students, process engineers and administrative staff looking for real-case analysis of pilot plants. This eBook brings together the research results and professional experiences of the most renowned work groups in the CO2 capture field...

  11. Corn residue removal and CO2 emissions (United States)

    Carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) are the primary greenhouse gases (GHG) emitted from the soil due to agricultural activities. In the short-term, increases in CO2 emissions indicate increased soil microbial activity. Soil micro-organisms decompose crop residues and release...

  12. Capturing CO2 via reactions in nanopores.

    Energy Technology Data Exchange (ETDEWEB)

    Leung, Kevin; Nenoff, Tina Maria; Criscenti, Louise Jacqueline; Tang, Z; Dong, J. H.


    This one-year exploratory LDRD aims to provide fundamental understanding of the mechanism of CO2 scrubbing platforms that will reduce green house gas emission and mitigate the effect of climate change. The project builds on the team members expertise developed in previous LDRD projects to study the capture or preferential retention of CO2 in nanoporous membranes and on metal oxide surfaces. We apply Density Functional Theory and ab initio molecular dynamics techniques to model the binding of CO2 on MgO and CaO (100) surfaces and inside water-filled, amine group functionalized silica nanopores. The results elucidate the mechanisms of CO2 trapping and clarify some confusion in the literature. Our work identifies key future calculations that will have the greatest impact on CO2 capture technologies, and provides guidance to science-based design of platforms that can separate the green house gas CO2 from power plant exhaust or even from the atmosphere. Experimentally, we modify commercial MFI zeolite membranes and find that they preferentially transmit H2 over CO2 by a factor of 34. Since zeolite has potential catalytic capability to crack hydrocarbons into CO2 and H2, this finding paves the way for zeolite membranes that can convert biofuel into H2 and separate the products all in one step.

  13. The challenges of monitoring CO2 storage

    NARCIS (Netherlands)

    Arts, R.; Vandeweijer, V.


    At present there is an increasing consensus that the global climate is changing as a result of increased atmospheric concentration of greenhouse gases such as CO2. The emissions of CO2 are directly linked to the abundant application of fossil energy sources. © 2011 Society of Exploration

  14. Flow assurance studies for CO2 transport

    NARCIS (Netherlands)

    Veltin, J.; Belfroid, S.P.C.


    In order to compensate for the relative lack of experience of the CCTS community, Flow Assurance studies of new CO2 pipelines and networks are a very important step toward reliable operation. This report details a typical approach for Flow Assurance study of CO2 transport pipeline. Considerations to

  15. Monitoring Options for CO2 Storage

    NARCIS (Netherlands)

    Arts, R.; Winthaegen, P.


    This chapter provides an overview of various monitoring techniques for CO2 storage that is structured into three categories-instrumentation in a well (monitoring well); instrumentation at the (near) surface (surface geophysical methods); and sampling at the (near) surface measuring CO2

  16. Toxic emissions and devaluated CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    with a climate policy whose goals of CO2-reduction were made operational by green-wash. Arguments are given for the devaluation of CO2- neutrality in case of burning wood. Alternative practices as storing C in high quality wood products and/or leaving wood in the forest are recommended. A counter...

  17. Increasing CO2 storage in oil recovery

    International Nuclear Information System (INIS)

    Jessen, Kristian; Kovscek, Anthony R.; Orr, Franklin M.


    Oil fields offer a significant potential for storing CO 2 and will most likely be the first large scale geological targets for sequestration as the infrastructure, experience and permitting procedures already exist. The problem of co-optimizing oil production and CO 2 storage differs significantly from current gas injection practice due to the cost-benefit imbalance resulting from buying CO 2 for enhanced oil recovery projects. Consequently, operators aim to minimize the amount of CO 2 required to sweep an oil reservoir. For sequestration purposes, where high availability of low cost CO 2 is assumed, the design parameters of enhanced oil recovery processes must be re-defined to optimize the amount of CO 2 left in the reservoir at the time of abandonment. To redefine properly the design parameters, thorough insight into the mechanisms controlling the pore scale displacement efficiency and the overall sweep efficiency is essential. We demonstrate by calculation examples the different mechanisms controlling the displacement behavior of CO 2 sequestration schemes, the interaction between flow and phase equilibrium and how proper design of the injection gas composition and well completion are required to co-optimize oil production and CO 2 storage

  18. Characterization of a microalgal mutant for CO2 biofixation and biofuel production

    International Nuclear Information System (INIS)

    Qi, Feng; Pei, Haiyan; Hu, Wenrong; Mu, Ruimin; Zhang, Shuo


    Highlights: • Combination of the isolation using 96-well microplates and traditional UV mutagenesis for screening HCT mutant. • Microalgal mutant Chlorella vulgaris SDEC-3M was screened out by modified UV mutagenesis. • SDEC-3M showed high CO 2 tolerance, high CO 2 requiring and relevant genetic stability. • LCE and carbohydrate content of SDEC-3M were significantly elevated. • SDEC-3M offers a strong candidature as CO 2 biofixation and biofuel production. - Abstract: In the present work, a Chlorella vulgaris mutant, named as SDEC-3M, was screened out through the combination of the isolation using 96-well microplates and traditional UV mutagenesis. Compared with its parent (wild type), the growth of SDEC-3M preferred higher CO 2 (15% v/v) environment to ambient air (0.038% CO 2 (v/v)), indicating that the mutant qualified with good tolerance and growth potential under high level CO 2 (high CO 2 tolerance) but was defective in directly utilizing the low level CO 2 (high CO 2 requiring). The genetic stability under ambient air and high level CO 2 was confirmed by a continuous cultivation for five generations. Higher light conversion efficiency (14.52%) and richer total carbohydrate content (42.48%) demonstrated that both solar energy and CO 2 were more effectively productively fixed into carbohydrates for bioethanol production than the parent strain. The mutant would benefit CO 2 biofixation from industrial exhaust gas to mitigate of global warming and promote biofuel production to relieve energy shortage.

  19. Continental-scale variation in controls of summer CO2 in United States lakes (United States)

    Lapierre, Jean-Francois; Seekell, David A.; Filstrup, Christopher T.; Collins, Sarah M.; Emi Fergus, C.; Soranno, Patricia A.; Cheruvelil, Kendra S.


    Understanding the broad-scale response of lake CO2 dynamics to global change is challenging because the relative importance of different controls of surface water CO2 is not known across broad geographic extents. Using geostatistical analyses of 1080 lakes in the conterminous United States, we found that lake partial pressure of CO2 (pCO2) was controlled by different chemical and biological factors related to inputs and losses of CO2 along climate, topography, geomorphology, and land use gradients. Despite weak spatial patterns in pCO2 across the study extent, there were strong regional patterns in the pCO2 driver-response relationships, i.e., in pCO2 "regulation." Because relationships between lake CO2 and its predictors varied spatially, global models performed poorly in explaining the variability in CO2 for U.S. lakes. The geographically varying driver-response relationships of lake pCO2 reflected major landscape gradients across the study extent and pointed to the importance of regional-scale variation in pCO2 regulation. These results indicate a higher level of organization for these physically disconnected systems than previously thought and suggest that changes in climate and land use could induce shifts in the main pathways that determine the role of lakes as sources and sinks of atmospheric CO2.

  20. Study of Pyridine-Mediated Electrochemical Reduction of CO2 to Methanol at High CO2 Pressure. (United States)

    Rybchenko, Sergey I; Touhami, Dalila; Wadhawan, Jay D; Haywood, Stephanie K


    The recently proposed highly efficient route of pyridine-catalyzed CO2 reduction to methanol was explored on platinum electrodes at high CO2 pressure. At 55 bar (5.5 MPa) of CO2 , the bulk electrolysis in both potentiostatic and galvanostatic regimes resulted in methanol production with Faradaic yields of up to 10 % for the first 5-10 C cm(-2) of charge passed. For longer electrolysis, the methanol concentration failed to increase proportionally and was limited to sub-ppm levels irrespective of biasing conditions and pyridine concentration. This limitation cannot be removed by electrode reactivation and/or pre-electrolysis and appears to be an inherent feature of the reduction process. In agreement with bulk electrolysis findings, the CV analysis supported by simulation indicated that hydrogen evolution is still the dominant electrode reaction in pyridine-containing electrolyte solution, even with an excess CO2 concentration in the solution. No prominent contribution from either a direct or coupled CO2 reduction was found. The results obtained suggest that the reduction of CO2 to methanol is a transient process that is largely decoupled from the electrode charge transfer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The ins and outs of CO2. (United States)

    Raven, John A; Beardall, John


    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3(-). The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3(-) use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3(-) active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3(-) can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3(-) pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3(-). Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  2. The ins and outs of CO2 (United States)

    Raven, John A.; Beardall, John


    It is difficult to distinguish influx and efflux of inorganic C in photosynthesizing tissues; this article examines what is known and where there are gaps in knowledge. Irreversible decarboxylases produce CO2, and CO2 is the substrate/product of enzymes that act as carboxylases and decarboxylases. Some irreversible carboxylases use CO2; others use HCO3 –. The relative role of permeation through the lipid bilayer versus movement through CO2-selective membrane proteins in the downhill, non-energized, movement of CO2 is not clear. Passive permeation explains most CO2 entry, including terrestrial and aquatic organisms with C3 physiology and biochemistry, terrestrial C4 plants and all crassulacean acid metabolism (CAM) plants, as well as being part of some mechanisms of HCO3 – use in CO2 concentrating mechanism (CCM) function, although further work is needed to test the mechanism in some cases. However, there is some evidence of active CO2 influx at the plasmalemma of algae. HCO3 – active influx at the plasmalemma underlies all cyanobacterial and some algal CCMs. HCO3 – can also enter some algal chloroplasts, probably as part of a CCM. The high intracellular CO2 and HCO3 – pools consequent upon CCMs result in leakage involving CO2, and occasionally HCO3 –. Leakage from cyanobacterial and microalgal CCMs involves up to half, but sometimes more, of the gross inorganic C entering in the CCM; leakage from terrestrial C4 plants is lower in most environments. Little is known of leakage from other organisms with CCMs, though given the leakage better-examined organisms, leakage occurs and increases the energetic cost of net carbon assimilation. PMID:26466660

  3. Silvering substrates after CO2 snow cleaning (United States)

    Zito, Richard R.


    There have been some questions in the astronomical community concerning the quality of silver coatings deposited on substrates that have been cleaned with carbon dioxide snow. These questions center around the possible existence of carbonate ions left behind on the substrate by CO2. Such carbonate ions could react with deposited silver to produce insoluble silver carbonate, thereby reducing film adhesion and reflectivity. Carbonate ions could be produced from CO2 via the following mechanism. First, during CO2 snow cleaning, a small amount of moisture can condense on a surface. This is especially true if the jet of CO2 is allowed to dwell on one spot. CO2 gas can dissolve in this moisture, producing carbonic acid, which can undergo two acid dissociations to form carbonate ions. In reality, it is highly unlikely that charged carbonate ions will remain stable on a substrate for very long. As condensed water evaporates, Le Chatelier's principle will shift the equilibrium of the chain of reactions that produced carbonate back to CO2 gas. Furthermore, the hydration of CO2 reaction of CO2 with H20) is an extremely slow process, and the total dehydrogenation of carbonic acid is not favored. Living tissues that must carry out the equilibration of carbonic acid and CO2 use the enzyme carbonic anhydrase to speed up the reaction by a factor of one million. But no such enzymatic action is present on a clean mirror substrate. In short, the worst case analysis presented below shows that the ratio of silver atoms to carbonate radicals must be at least 500 million to one. The results of chemical tests presented here support this view. Furthermore, film lift-off tests, also presented in this report, show that silver film adhesion to fused silica substrates is actually enhanced by CO2 snow cleaning.

  4. Recent increase in surface fCO2 in the western subtropical North Pacific (United States)

    Kim, Dongseon; Choi, Yujeong; Kim, Tae-Wook; Park, Geun-Ha


    We observed unusually high levels (> 440 μatm) of carbon dioxide fugacity (fCO2) in surface seawater in the western subtropical North Pacific, the area where Subtropical Mode Water is formed, during summer 2015. The NOAA Kuroshio Extension Observatory moored buoy located in this region also measured high CO2 values, up to 500 μatm during this period. These high sea surface fCO2 (fCO2SW) values are explained by much higher normalized total dissolved inorganic carbon and slightly higher normalized total alkalinity concentrations in this region compared to the equatorial Pacific. Moreover, these values are much higher than the climatological CO2 values, even considering increasing atmospheric CO2, indicating a recent large increase in sea surface CO2 concentrations. A large seasonal change in sea surface temperature contributed to higher surface fCO2SW in the summer of 2015.

  5. CO2 Flux Inversion Error Analyses for Future Active Space CO2 Missions like ASCENDS (United States)

    Baker, D. F.; Kawa, S. R.; Rayner, P. J.; Browell, E. V.; Menzies, R. T.; Abshire, J. B.


    We assess the ability of different proposed CO2 lidar measurement approaches to constrain surface CO2 fluxes, as part of the development of science requirements for NASA's ASCENDS mission. Observing system simulation experiments (OSSEs) are performed for different overall measurement uncertainty levels and vertical weightings to determine what designs will yield useful new information on the global carbon cycle. The OSSEs are based on a variational data assimilation method that models the measurements at the time and location they occur with minimal averaging and solves for the surface fluxes at regional spatial scales. Measurements are simulated using the PCTM off-line atmospheric transport model driven by GEOS5 analysis data (winds and vertical mixing parameters) and forced by realistic modeled CO2 fluxes. Both day- and night-side fluxes are estimated in weekly blocks at 4.5°x6° resolution (lat/lon) using a full year of simulated data. Error estimates are computed by direct comparison to the known truth; only random errors in the measurements and assumed flux prior are considered here. Relative measurement uncertainties and vertical averaging kernels have been derived for lidar measurements made using CO2 absorption lines in the 1.57 and 2.06 micron bands using realistic assumptions about clouds, aerosols, and surface reflectivity taken from CALIPSO and MODIS. Two measurement cases are considered for the 1.57 μm band, one using a vertical weighting function weighted to the mid- to lower troposphere, and one combining this with a function peaking near the tropopause. A third case is considered for measurements in the 2.06 μm band, with a vertical weighting peaking strongly near the surface. For each of these cases, three overall measurement uncertainty levels are examined (tied to reference uncertainties of 1.0, 0.5, and 0.2 ppm (1σ) at Railroad Valley, Nevada). OSSEs with simple measurement biases are run to test how the random-error-only findings hold in

  6. Dynamics of CO2 fluxes and concentrations during a shallow subsurface CO2 release

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, J.L.; Hilley, G.E.; Dobeck, L.; Spangler, L.


    A field facility located in Bozeman, Montana provides the opportunity to test methods to detect, locate, and quantify potential CO2 leakage from geologic storage sites. From 9 July to 7 August 2008, 0.3 t CO2 d{sup -1} were injected from a 100-m long, {approx}2.5 m deep horizontal well. Repeated measurements of soil CO2 fluxes on a grid characterized the spatio-temporal evolution of the surface leakage signal and quantified the surface leakage rate. Infrared CO2 concentration sensors installed in the soil at 30 cm depth at 0 to 10 m from the well and at 4 cm above the ground at 0 and 5 m from the well recorded surface breakthrough of CO2 leakage and migration of CO2 leakage through the soil. Temporal variations in CO2 concentrations were correlated with atmospheric and soil temperature, wind speed, atmospheric pressure, rainfall, and CO2 injection rate.

  7. Carbon recycling by cyanobacteria: improving CO2 fixation through chemical production. (United States)

    Zhang, Angela; Carroll, Austin L; Atsumi, Shota


    Atmospheric CO2 levels have reached an alarming level due to industrialization and the burning of fossil fuels. In order to lower the level of atmospheric carbon, strategies to sequester excess carbon need to be implemented. The CO2-fixing mechanism in photosynthetic organisms enables integration of atmospheric CO2 into biomass. Additionally, through exogenous metabolic pathways in these photosynthetic organisms, fixed CO2 can be routed to produce various commodity chemicals that are currently produced from petroleum. This review will highlight studies and modifications to different components of cyanobacterial CO2-fixing systems, as well as the application of these systems toward CO2-derived chemical production. 2,3-Butanediol is given particular focus as one of the most thoroughly studied systems for conversion of CO2 to a bioproduct. © FEMS 2017. All rights reserved. For permissions, please e-mail:

  8. CO2alters community composition of freshwater phytoplankton: A microcosm experiment. (United States)

    Shi, Xiaoli; Li, Shengnan; Wei, Lijun; Qin, Boqiang; Brookes, Justin D


    The effects of CO 2 and related changes in water carbonate chemistry on freshwater phytoplankton were studied in in situ microcosm experiments, performed in East Lake Taihu, in August 2013 and April 2014, respectively. The microcosm treatments represented low (270ppm), present (380ppm), and high (750ppm) pCO 2 conditions. Elevated CO 2 decreased pH and increased aqueous CO 2 concentrations, and did not change alkalinity. The maximum reduction of pH was 0.26 when CO 2 increased from current level to 750ppm at the ending of experiment in the spring. The rise of pCO 2 stimulated the growth of phytoplankton, and the net primary production could increase by 35% when CO 2 was elevated from current level to 750ppm in summer. Interestingly, our results indicated that increasing pCO 2 affected phytoplankton community structure in the microcosms. Cyanobacteria tended to be superior under high pCO 2 , with two species Anabaena circinalis and Anabaena eucompacta benefitting from the rising pCO 2 . The response of chlorophytes and diatoms to the rise of pCO 2 depended on taxa. In contrast, increased CO 2 did not change biomass or productivity of phytoplankton in spring, when biomass was relatively low. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Acclimation to Very Low CO2: Contribution of Limiting CO2 Inducible Proteins, LCIB and LCIA, to Inorganic Carbon Uptake in Chlamydomonas reinhardtii1[OPEN (United States)

    Spalding, Martin H.


    The limiting-CO2 inducible CO2-concentrating mechanism (CCM) of microalgae represents an effective strategy to capture CO2 when its availability is limited. At least two limiting-CO2 acclimation states, termed low CO2 and very low CO2, have been demonstrated in the model microalga Chlamydomonas reinhardtii, and many questions still remain unanswered regarding both the regulation of these acclimation states and the molecular mechanism underlying operation of the CCM in these two states. This study examines the role of two proteins, Limiting CO2 Inducible A (LCIA; also named NAR1.2) and LCIB, in the CCM of C. reinhardtii. The identification of an LCIA-LCIB double mutant based on its inability to survive in very low CO2 suggests that both LCIA and LCIB are critical for survival in very low CO2. The contrasting effects of individual mutations in LCIB and LCIA compared with the effects of LCIB-LCIA double mutations on growth and inorganic carbon-dependent photosynthetic O2 evolution reveal distinct roles of LCIA and LCIB in the CCM. Although both LCIA and LCIB are essential for very low CO2 acclimation, LCIB appears to function in a CO2 uptake system, whereas LCIA appears to be associated with a HCO3− transport system. The contrasting and complementary roles of LCIA and LCIB in acclimation to low CO2 and very low CO2 suggest a possible mechanism of differential regulation of the CCM based on the inhibition of HCO3− transporters by moderate to high levels of CO2. PMID:25336519

  10. Background Error Statistics for Assimilation of Atmospheric CO2 (United States)

    Chatterjee, A.; Engelen, R. J.; Kawa, S. R.; Sweeney, C.; Michalak, A. M.


    Recent improvements in the CO2 observational density have spurred the development and application of data assimilation systems for extracting information about global CO2 distributions from available observations. A novel application that has been pursued at the European Centre for Medium-Range Weather Forecasts (ECMWF), as part of the Monitoring Atmospheric Composition and Climate (MACC) project, is to use a state-of-the-art 4DVAR system to assimilate CO2 observations, along with meteorological variables to obtain a consistent estimate of atmospheric CO2 concentrations. Global CO2 fields generated in this way enhance the observational database, because the data assimilation procedure uses physical and dynamical laws, along with the available observations, to constrain the analysis. As in any data assimilation framework, the background error covariance matrix plays the critical role of filtering the observed information and propagating it to nearby grid points and levels of the assimilating model. For atmospheric CO2 assimilation, however, the errors in the background are not only impacted by the uncertainties in the CO2 transport but also by the spatial and temporal variability of the carbon exchange at the Earth surface. The background errors cannot be prescribed via traditional forecast-based methods as these fail to account for the uncertainties in the carbon emissions and uptake, resulting in an overall underestimation of the errors. We present a unique approach for characterizing the background error statistics whereby the differences between two CO2 model concentrations are used as a proxy for the statistics of the background errors. The resulting error statistics - 1) vary regionally and seasonally to better capture the changing degree of variability in the background CO2 field, 2) are independent of the observation density, and 3) have a discernible impact on the analysis estimates by allowing observations to adjust predictions over a larger area. In this

  11. Increasing stomatal conductance in response to rising atmospheric CO2. (United States)

    Purcell, C; Batke, S P; Yiotis, C; Caballero, R; Soh, W K; Murray, M; McElwain, J C


    Studies have indicated that plant stomatal conductance (gs) decreases in response to elevated atmospheric CO2, a phenomenon of significance for the global hydrological cycle. However, gs increases across certain CO2 ranges have been predicted by optimization models. The aim of this work was to demonstrate that under certain environmental conditions, gs can increase in response to elevated CO2. Using (1) an extensive, up-to-date synthesis of gs responses in free air CO2 enrichment (FACE)experiments, (2) in situ measurements across four biomes showing dynamic gs responses to a CO2 rise of ~50 ppm (characterizing the change in this greenhouse gas over the past three decades) and (3) a photosynthesis-stomatal conductance model, it is demonstrated that gs can in some cases increase in response to increasing atmospheric CO2. Field observations are corroborated by an extensive synthesis of gs responses in FACE experiments showing that 11.8 % of gs responses under experimentally elevated CO2 are positive. They are further supported by a strong data-model fit (r2 = 0.607) using a stomatal optimization model applied to the field gs dataset. A parameter space identified in the Farquhar-Ball-Berry photosynthesis-stomatal conductance model confirms field observations of increasing gs under elevated CO2 in hot dry conditions. Contrary to the general assumption, positive gs responses to elevated CO2, although relatively rare, are a feature of woody taxa adapted to warm, low-humidity conditions, and this response is also demonstrated in global simulations using the Community Land Model (CLM4). The results contradict the over-simplistic notion that global vegetation always responds with decreasing gs to elevated CO2, a finding that has important implications for predicting future vegetation feedbacks on the hydrological cycle at the regional level. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For


    Directory of Open Access Journals (Sweden)

    Laily Agustina Rahmawati


    optimalisasi lahan sangat optimal (tutupan vegetasi 90% pada lahan pekarangan untuk rumah tangga KEB.   ABSTRACT Households with all its activities contributed to CO2 emissions that lead to global warming. Therefore, based on the polluter pays principle (pollutant pay principle, households may be held responsible for the emissions produced in the form of land conservation. The study aims to analyze the average emissions and the average sequestration, to determine the minimum area of land to be conserved each household group Economy Class Upper (Power KEA- ≥ 1300 VA, Economy Class Intermediate (back Power 900 VA, Down Economy Class (KEA- Power 450 VA in the village of Sinduadi, Mlati subdistrict, Sleman, Yogyakarta. CO2 emissions are calculated based on household activities related to electricity consumption, fuel consumption for transportation, fuel consumption for cooking, waste production and water consumption taps, obtained from the questionnaire were subsequently multiplied by the conversion of CO2 emissions tersesedia. CO2 sequestration is calculated based biomass is retained by households on their vegetated land (yards, fields, gardens. Biomass estimation obtained through the method of Brown (1997 and Hairiah (2007, by nested qudrat sampling on each type of vegetated land owned by households. And the minimum area of land optimization, CO2 emissions are calculated based on the number of households and biomass per m2 of land. Based on the survey results revealed, households had an average Sinduadi emissions and sequestration, and the minimum area of land consecutively for: 7098.98 kgCO2 / th, 267.34 kgCO2 / th, and 178.11 m2 with a very level land optimization optimal (vegetation cover 90% in their yards for household KEA; 3785.9 kgCO2 / th, 632.61 kgCO2 / th, and 1551.37 m2 yard area with the optimization level is optimal land (vegetation cover 90% in their yards for household KEM; 1973.3 kgCO2 / th, 780.21 kgCO2 / th, and 898.91 m2 with very optimal level of

  13. Estimating CO2 Emission Reduction of Non-capture CO2 Utilization (NCCU) Technology

    International Nuclear Information System (INIS)

    Lee, Ji Hyun; Lee, Dong Woog; Gyu, Jang Se; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo; Choi, Jong Shin


    Estimating potential of CO 2 emission reduction of non-capture CO 2 utilization (NCCU) technology was evaluated. NCCU is sodium bicarbonate production technology through the carbonation reaction of CO 2 contained in the flue gas. For the estimating the CO 2 emission reduction, process simulation using process simulator (PRO/II) based on a chemical plant which could handle CO 2 of 100 tons per day was performed, Also for the estimation of the indirect CO 2 reduction, the solvay process which is a conventional technology for the production of sodium carbonate/sodium bicarbonate, was studied. The results of the analysis showed that in case of the solvay process, overall CO 2 emission was estimated as 48,862 ton per year based on the energy consumption for the production of NaHCO 3 (7.4 GJ/tNaHCO 3 ). While for the NCCU technology, the direct CO 2 reduction through the CO 2 carbonation was estimated as 36,500 ton per year and the indirect CO 2 reduction through the lower energy consumption was 46,885 ton per year which lead to 83,385 ton per year in total. From these results, it could be concluded that sodium bicarbonate production technology through the carbonation reaction of CO 2 contained in the flue was energy efficient and could be one of the promising technology for the low CO 2 emission technology.

  14. CO2 content of electricity losses

    International Nuclear Information System (INIS)

    Daví-Arderius, Daniel; Sanin, María-Eugenia; Trujillo-Baute, Elisa


    Countries are implementing policies to develop greener energy markets worldwide. In Europe, the ¨2030 Energy and Climate Package¨ asks for further reductions of green house gases, renewable sources integration, and energy efficiency targets. But the polluting intensity of electricity may be different in average than when considering market inefficiencies, in particular losses, and therefore the implemented policy must take those differences into account. Precisely, herein we study the importance in terms of CO2 emissions the extra amount of energy necessary to cover losses. With this purpose we use Spanish market and system data with hourly frequency from 2011 to 2013. Our results show that indeed electricity losses significantly explain CO2 emissions, with a higher CO2 emissions rate when covering losses than the average rate of the system. Additionally, we find that the market closing technologies used to cover losses have a positive and significant impact on CO2 emissions: when polluting technologies (coal or combined cycle) close the market, the impact of losses on CO2 emissions is high compared to the rest of technologies (combined heat and power, renewables or hydropower). To the light of these results we make some policy recommendations to reduce the impact of losses on CO2 emissions. - Highlights: • Electricity losses significantly explain CO2 emissions. • Policies aimed to reducing losses have a positive impact on CO2 emissions. • The market closing technology used to cover losses have impacts on CO2 emissions. • Pollutant technologies that close the market should be replaced by renewables.

  15. Studies on CO 2 laser marking (United States)

    Ueda, Masahiro; Saitoh, Yoshikazu; Hachisuka, Hideki; Ishigaki, Hiroyuki; Gokoh, Yukihiro; Mantani, Hiroshi

    The nature of CO 2 laser marking was studied with a view to putting these lasers to practical use in the semiconductor industry. The marking is found to be due to surface spattering rather than burning, which is the main factor in YAG laser marking. The visibility greatly increases by the application of a surface treatment such as marker ink, varnish or poster color. The CO 2 laser may therefore be used in place of the YAG laser, now widely used for marking, with some merits: CO 2 laser marking is cheaper and faster, and in addition there is no danger of injury from irradiating laser light.

  16. Studies on CO2 Laser Marking


    UEDA, Masahiro; SAITOH, Yoshikazu; HACHISUKA, Hideki; ISHIGAKI, Hiroyuki; GOKOH, Yukihiro; MANTANI, Hiroshi


    The nature of CO2 laser marking was studied with a view to putting these lasers to practical use in the semiconductor industry. The marking is found to be due to surface spattering rather than burning, which is the main factor in YAG laser marking. The visibility greatly increases by the application of a surface treatment such as marker ink, varnish or poster color. The CO2 laser may therefore be used in place of the YAG laser, now widely used for marking, with some merits: CO2 laser marki...

  17. The Idea of Global CO2 Trade

    DEFF Research Database (Denmark)

    Svendsen, Gert Tinggaard


    -effective control which can solve future global environmental problems. The gains from CO2 trade may give vital financial subsidies from the EU to Eastern Europe, for example, and it will probably not pay to cheat if quotas are renewed periodically by the UN. Cheating countries are then to be excluded from further......The US has been criticized for wanting to earn a fortune on a global CO2 market. However, compared to the situation without trade and provided that such a market is designed so that it does not pay to cheat, a global CO2 market may provide the world with an epoch-making means of cost...

  18. Theory of gastric CO2 ventilation and its control during respiratory acidosis: implications for central chemosensitivity, pH regulation, and diseases causing chronic CO2 retention. (United States)

    Dean, Jay B


    The theory of gastric CO(2) ventilation describes a previously unrecognized reflex mechanism controlled by neurons in the caudal solitary complex (cSC) for non-alveolar elimination of systemic CO(2) during respiratory acidosis. Neurons in the cSC, which is a site of CO(2) chemosensitivity for cardiorespiratory control, also control various gastroesophageal reflexes that remove CO(2) from blood. CO(2) is consumed in the production of gastric acid and bicarbonate in the gastric epithelium and then reconstituted as CO(2) in the stomach lumen from the reaction between H(+) and HCO(3)(-). Respiratory acidosis and gastric CO(2) distension induce cSC/vagovagal mediated transient relaxations of the lower esophageal sphincter to vent gastric CO(2) upwards by bulk flow along an abdominal-to-esophageal (=intrapleural) pressure gradient the magnitude of which increases during abdominal (gastric) compression caused by increased contractions of respiratory muscles. Esophageal distension induces cSC/nucleus ambiguus/vagovagal reflex relaxation of the upper esophageal sphincter and CO(2) is vented into the pharynx and mixed with pulmonary gas during expiration or, alternatively, during eructation. It is proposed that gastric CO(2) ventilation provides explanations for (1) the postprandial increase in expired CO(2) and (2) the negative P(blood - expired)CO₂difference that occurs with increased inspired CO(2). Furthermore, it is postulated that gastric CO(2) ventilation and alveolar CO(2) ventilation are coordinated under dual control by CO(2) chemosensitive neurons in the cSC. This new theory, therefore, presupposes a level of neural control and coordination between two previously presumed dissimilar organ systems and supports the notion that different sites of CO(2) chemosensitivity address different aspects of whole body pH regulation. Consequently, not all sites of central chemosensitivity are equal regarding the mechanism(s) activated for CO(2) elimination. A distributed CO(2

  19. Equilibration of metabolic CO2 with preformed CO2 and bicarbonate

    International Nuclear Information System (INIS)

    Hems, R.; Saez, G.T.


    Entry of metabolic 14 CO 2 into urea is shown to occur more readily than it equilibrates with the general pool of cellular plus extracellular bicarbonate plus CO 2 . Since the sites of CO 2 production (pyruvate dehydrogenase and oxoglutarate dehydrogenase) and of fixation (carbamoylphosphate synthetase) are intramitochondrial, it is likely that the fixation of CO 2 is also more rapid than its equilibration with the cytoplasmic pool of bicarbonate plus CO 2 . This observation may point to a more general problem concerning the interpretation of isotope data, with compartmentation or proximity of sites of production and utilisation of metabolites may result in the isotope following a preferred pathway. (Auth.)

  20. Continuous CO2 gas monitoring to clarify natural pattern and artificial leakage signals (United States)

    Joun, W.; Ha, S. W.; Joo, Y. J.; Lee, S. S.; Lee, K. K.


    Continuous CO2 gas monitoring at shallow aquifer is significant for early detection and immediate handling of an aquifer impacted by leaking CO2 gas from the sequestration reservoir. However, it is difficult to decide the origin of CO2 gas because detected CO2 includes not only leaked CO2 but also naturally emitted CO2. We performed CO2 injection and monitoring tests in a shallow aquifer. Before the injection of CO2 infused water, we have conducted continuous monitoring of multi-level soil CO2 gas concentration and physical parameters such as temperature, humidity, pressure, wind speed and direction, and precipitation. The monitoring data represented that CO2 gas concentrations in unsaturated soil zone borehole showed differences at depths and daily variation (360 to 6980 ppm volume). Based on the observed data at 5 m and 8 m depths, vertical flux of gas was calculated as 0.471 L/min (LPM) for inflow from 5 m to 8 m and 9.42E-2 LPM for outflow from 8 m to 5 m. The numerical and analytical models were used to calculate the vertical flux of gas and to compare with observations. The results showed that pressure-based modeling could not explain the rapid change of CO2 gas concentration in borehole. Acknowledgement Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003)

  1. Can Producing Oil Store Carbon? Greenhouse Gas Footprint of CO2EOR, Offshore North Sea. (United States)

    Stewart, R Jamie; Haszeldine, R Stuart


    Carbon dioxide enhanced oil recovery (CO2EOR) is a proven and available technology used to produce incremental oil from depleted fields while permanently storing large tonnages of injected CO2. Although this technology has been used successfully onshore in North America and Europe, there are currently no CO2EOR projects in the United Kingdom. Here, we examine whether offshore CO2EOR can store more CO2 than onshore projects traditionally have and whether CO2 storage can offset additional emissions produced through offshore operations and incremental oil production. Using a high-level Life Cycle system approach, we find that the largest contribution to offshore emissions is from flaring or venting of reproduced CH4 and CO2. These can already be greatly reduced by regulation. If CO2 injection is continued after oil production has been optimized, then offshore CO2EOR has the potential to be carbon negative--even when emissions from refining, transport, and combustion of produced crude oil are included. The carbon intensity of oil produced can be just 0.056-0.062 tCO2e/bbl if flaring/venting is reduced by regulation. This compares against conventional Saudi oil 0.040 tCO2e/bbl or mined shale oil >0.300 tCO2e/bbl.

  2. Photocatalytic Conversion of CO2 on Mars (United States)

    Meier, Annie; Hare, Bryan


    Light on Mars shows potential for providing the energy means necessary for enhanced In-Situ Resource Utilization (ISRU). Through photocatalysis, the energy barrier required to convert CO2 is lowered and CH4 production is favorable.

  3. Sustainable Process Networks for CO2 Conversion

    DEFF Research Database (Denmark)

    Frauzem, Rebecca; Kongpanna, P.; Pavarajam, V.

    , such as methanol (MeOH) have the largest market, this network will include a variety of thermodynamically feasible conversion paths [4]. From reviews of work previously done, there are ranges of possible products that are formed from CO2 and another co-reactant directly. Methanol, dimethyl ether, dimethyl...... the emissions is the conversion of CO2 into useful products, such as methanol [3]. In this work, through a computer-aided framework for process network synthesis-design, a network of feasible conversion processes that all use emitted CO2 is investigated. CO2 is emitted into the environment from various sources......: power generation, industrial processes, transportation and commercial processes. Within these there are high-purity emissions and low-purity emissions. Rather than sending these to the atmosphere, it is possible to collect them and use them for other purposes. In this work, the first step is determining...

  4. CO2 emissions in the steel industry

    Directory of Open Access Journals (Sweden)

    M. Kundak


    Full Text Available Global CO2 emissions caused by the burning of fossil fuels over the past century are presented. Taking into consideration the total world production of more than 1,3 billion tons of steel, the steel industry produces over two billion tons of CO2. Reductions in CO2 emissions as a result of technological improvements and structural changes in steel production in industrialized countries during the past 40 years are described. Substantial further reductions in those emissions will not be possible using conventional technologies. Instead, a radical cutback may be achieved if, instead of carbon, hydrogen is used for direct iron ore reduction. The cost and the ensuing CO2 generation in the production of hydrogen as a reducing agent from various sources are analysed.

  5. CO2 Washout Capability with Breathing Manikin (United States)

    National Aeronautics and Space Administration — Carbon Dioxide (CO2) Washout performance is a critical parameter needed to ensure proper and sufficient designs in a spacesuit and in vehicle applications such as...

  6. Capture and geological storage of CO2

    International Nuclear Information System (INIS)


    Capture and geological storage of CO 2 could be a contribution to reduce CO 2 emissions, and also a way to meet the factor 4 objective of reduction of greenhouse gas emissions. This publication briefly presents the capture and storage definitions and principles, and comments some key data related to CO 2 emissions, and their natural trapping by oceans, soils and forests. It discusses strengths (a massive and perennial reduction of CO 2 emissions, a well defined regulatory framework) and weaknesses (high costs and uncertain cost reduction perspectives, a technology which still consumes a lot of energy, geological storage capacities still to be determined, health environmental impacts and risks to be controlled, a necessary consultation of population for planned projects) of this option. Actions undertaken by the ADEME are briefly reviewed

  7. Thermodynamic modeling of CO2 mixtures

    DEFF Research Database (Denmark)

    Bjørner, Martin Gamel

    Knowledge of the thermodynamic properties and phase equilibria of mixtures containing carbon dioxide (CO2) is important in several industrial processes such as enhanced oil recovery, carbon capture and storage, and supercritical extractions, where CO2 is used as a solvent. Despite this importance......, accurate predictions of the thermodynamic properties and phase equilibria of mixtures containing CO2 are challenging with classical models such as the Soave-Redlich-Kwong (SRK) equation of state (EoS). This is believed to be due to the fact, that CO2 has a large quadrupole moment which the classical models...... and with or without introducing an additional pure compound parameter. In the absence of quadrupolar compounds qCPA reduces to CPA, which itself reduces toSRK in the absence of association. As the number of adjustable parameters in thermodynamic models increase, the parameter estimation problem becomes increasingly...

  8. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    Verlaat, Bartholomeus; The ATLAS collaboration


    The Atlas Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity. This paper describes the design, development, construction and commissioning of the IBL CO2 cooling system. It describes the challenges overcome and the important lessons learned for the development of future systems which are now under design for the Phase-II upgrade detectors.

  9. The BIG protein distinguishes the process of CO2-induced stomatal closure from the inhibition of stomatal opening by CO2. (United States)

    He, Jingjing; Zhang, Ruo-Xi; Peng, Kai; Tagliavia, Cecilia; Li, Siwen; Xue, Shaowu; Liu, Amy; Hu, Honghong; Zhang, Jingbo; Hubbard, Katharine E; Held, Katrin; McAinsh, Martin R; Gray, Julie E; Kudla, Jörg; Schroeder, Julian I; Liang, Yun-Kuan; Hetherington, Alistair M


    We conducted an infrared thermal imaging-based genetic screen to identify Arabidopsis mutants displaying aberrant stomatal behavior in response to elevated concentrations of CO 2 . This approach resulted in the isolation of a novel allele of the Arabidopsis BIG locus (At3g02260) that we have called CO 2 insensitive 1 (cis1). BIG mutants are compromised in elevated CO 2 -induced stomatal closure and bicarbonate activation of S-type anion channel currents. In contrast with the wild-type, they fail to exhibit reductions in stomatal density and index when grown in elevated CO 2 . However, like the wild-type, BIG mutants display inhibition of stomatal opening when exposed to elevated CO 2 . BIG mutants also display wild-type stomatal aperture responses to the closure-inducing stimulus abscisic acid (ABA). Our results indicate that BIG is a signaling component involved in the elevated CO 2 -mediated control of stomatal development. In the control of stomatal aperture by CO 2 , BIG is only required in elevated CO 2 -induced closure and not in the inhibition of stomatal opening by this environmental signal. These data show that, at the molecular level, the CO 2 -mediated inhibition of opening and promotion of stomatal closure signaling pathways are separable and BIG represents a distinguishing element in these two CO 2 -mediated responses. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  10. Natural Analogues of CO2 Geological Storage

    International Nuclear Information System (INIS)

    Perez del Villar, L.; Pelayo, M.; Recreo, F.


    Geological storage of carbon dioxide is nowadays, internationally considered as the most effective method for greenhouse gas emission mitigation, in order to minimize the global climate change universally accepted. Nevertheless, the possible risks derived of this long-term storage have a direct influence on its public acceptance. Among the favourable geological formations to store CO2, depleted oil and gas fields, deep saline reservoirs, and unamiable coal seams are highlighted. One of the most important objectives of the R and D projects related to the CO2 geological storage is the evaluation of the CO2 leakage rate through the above mentioned geological formations. Therefore, it is absolutely necessary to increase our knowledge on the interaction among CO2, storage and sealing formations, as well as on the flow paths and the physical resistance of the sealing formation. The quantification of the CO2 leakage rate is essential to evaluate the effects on the human and animal health, as well as for the ecosystem and water quality. To achieve these objectives, the study of the natural analogues is very useful in order to know the natural leakage rate to the atmosphere, its flow paths, the physical, chemical and mineralogical modifications due to the long term interaction processes among the CO2 and the storage and sealing formations, as well as the effects on the groundwaters and ecosystems. In this report, we have tried to summarise the main characteristics of the natural reservoirs and surficial sources of CO2, which are both natural analogues of the geological storage and CO2 leakage, studied in EEUU, Europe and Australia. The main objective of this summary is to find the possible applications for long-term risk prediction and for the performance assessment by means of conceptual and numerical modelling, which will allow to validate the predictive models of the CO2 storage behaviour, to design and develop suitable monitoring techniques to control the CO2 behaviour

  11. Pulmonary CO2 elimination during surgical procedures using intra- or extraperitoneal CO2 insufflation. (United States)

    Mullett, C E; Viale, J P; Sagnard, P E; Miellet, C C; Ruynat, L G; Counioux, H C; Motin, J P; Boulez, J P; Dargent, D M; Annat, G J


    We examined end-tidal CO2 tension (PETCO2) and pulmonary CO2 elimination of CO2 (VECO2) during CO2 insufflation under general anesthesia for three surgical procedures: gynecologic laparoscopy (intraperitoneal CO2 insufflation for 43 +/- 4 min), laparoscopic cholecystectomy (intraperitoneal CO2 insufflation for 125 +/- 14 min), and pelviscopy (extraperitoneal CO2 insufflation for 45 +/- 3 min). All patients (10 in each group) underwent controlled mechanical ventilation. Oxygen consumption (VO2) and VECO2 were measured at 2-min intervals by a system using a mass spectrometer. For the three surgical procedures, VO2 remained stable, whereas VECO2 and PETCO2 increased in parallel from the 8th to the 10th min after the start of CO2 insufflation. A plateau was reached 10 min later in patients having intraperitoneal insufflation, whereas VECO2 and PETCO2 continued to increase slowly throughout CO2 insufflation during pelviscopy. During pelviscopy, the maximum increase in VECO2 and PETCO2 (76 +/- 5% and 71 +/- 7%) was significantly more pronounced than that observed during cholecystectomy (25 +/- 4% and 25 +/- 4%) and gynecologic laparoscopy (15 +/- 3% and 12 +/- 2%). The authors conclude that CO2 diffusion into the body is more marked during extraperitoneal than during intraperitoneal CO2 insufflation but is not influenced markedly by the duration of intraperitoneal insufflation.

  12. CO2 Sensing and CO2 Regulation of Stomatal Conductance: Advances and Open Questions. (United States)

    Engineer, Cawas B; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordström, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian I


    Guard cells form epidermal stomatal gas-exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration ([CO2]) in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense [CO2] changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in the CO2 regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars that perform better in a shifting climate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Udvikling af CO2 neutralt byrumsarmatur

    DEFF Research Database (Denmark)

    Poulsen, Peter Behrensdorff; Dam-Hansen, Carsten; Corell, Dennis Dan

    Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt.......Denne rapport indeholder en beskrivelse af arbejdet udført i og resultaterne af forsknings- og udviklingsprojektet ” Udvikling af CO2 neutralt byrumsarmatur” og udgør slutrapportering for dette projekt....

  14. Combustion of hythane diluted with CO2

    Directory of Open Access Journals (Sweden)

    Hraiech Ibtissem


    Full Text Available With increasing concern about energy shortage and environmental protection, improving engine fuel economy and reducing exhaust emissions have become major research topics in combustion and engine development. Hythane (a blend of hydrogen H2 and natural gas NG has generated a significant interest as an alternative fuel for the future. This paper describes an experimental study of the effects of CO2 addition on the stability of a turbulent jet diffusion NG-H2 flame. The mole fraction of hydrogen (% H2 in NG-H2 mixture was varied from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept at stoichiometry. The results show that the lift-off height increases with the addition of CO2 at various % H2 content in hythane. However, we observe that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while for 0% H2, the flame is blown out above 20% CO2. This means that the limits of flame blowing out are pushed with the additions of H2. Moreover, the results show that for %H2 content in NG-H2 fuel up to 10%, the addition of CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution, flame would remain attached until blow-out. This is mainly due to the fact that the dilution leads to ejection velocities very high but reactivity of the mixture does not change so the flame tends to stretch.

  15. Membraneless water filtration using CO2


    Shin, Sangwoo; Shardt, Orest; Warren, Patrick B.; Stone, Howard A.


    Water purification technologies such as microfiltration/ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO2. Dissolution of CO2 into the suspension creates solute gradients that drive phoreti...

  16. Flow assurance studies for CO2 transport


    Veltin, J.; Belfroid, S.P.C.


    In order to compensate for the relative lack of experience of the CCTS community, Flow Assurance studies of new CO2 pipelines and networks are a very important step toward reliable operation. This report details a typical approach for Flow Assurance study of CO2 transport pipeline. Considerations to take during the design of a pipeline are highlighted, with an emphasis on operability of the system. The steady state aspects of a pipeline operation are first addressed, putting some highlight in...

  17. The millennial atmospheric lifetime of anthropogenic CO2

    International Nuclear Information System (INIS)

    Archer, D.


    The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO 2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere/ocean carbon cycle, which we review here. The largest fraction of the CO 2 recovery will take place on time scales of centuries, as CO 2 invades the ocean, but a significant fraction of the fossil fuel CO 2 , ranging in published models in the literature from 20-60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste. The glacial/interglacial climate cycles demonstrate that ice sheets and sea level respond dramatically to millennial-timescale changes in climate forcing. There are also potential positive feedbacks in the carbon cycle, including methane hydrates in the ocean, and peat frozen in permafrost, that are most sensitive to the long tail of the fossil fuel CO 2 in the atmosphere

  18. Increasing CO2 flux at Pisciarelli, Campi Flegrei, Italy

    Directory of Open Access Journals (Sweden)

    M. Queißer


    Full Text Available The Campi Flegrei caldera is located in the metropolitan area of Naples (Italy and has been undergoing different stages of unrest since 1950, evidenced by episodes of significant ground uplift followed by minor subsidence, increasing and fluctuating emission strengths of water vapor and CO2 from fumaroles, and periodic seismic crises. We deployed a scanning laser remote-sensing spectrometer (LARSS that measured path-integrated CO2 concentrations in the Pisciarelli area in May 2017. The resulting mean CO2 flux is 578 ± 246 t d−1. Our data suggest a significant increase in CO2 flux at this site since 2015. Together with recent geophysical observations, this suggests a greater contribution of the magmatic source to the degassing and/or an increase in permeability at shallow levels. Thanks to the integrated path soundings, LARSS may help to give representative measurements from large regions containing different CO2 sources, including fumaroles, low-temperature vents, and degassing soils, helping to constrain the contribution of deep gases and their migration mechanisms towards the surface.

  19. Calibrating Laser Gas Measurements by Use of Natural CO2 (United States)

    Webster, Chris


    continuously as a calibration standard for every measurement point. Figure 1 depicts simulated spectral transmission measurements in a wavenumber range that contains two absorption lines of N2O and one of CO2. The simulations were performed for two different upper-atmospheric pressures for an airborne instrument that has a path length of 80 m. The relative abundance of CO2 in air was assumed to be 360 parts per million by volume (approximately its natural level in terrestrial air). In applying the present method to measurements like these, one could average the signals from the two N2O absorption lines and normalize their magnitudes to that of the CO2 absorption line. Other gases with which this calibration method can be used include H2O, CH4, CO, NO, NO2, HOCl, C2H2, NH3, O3, and HCN. One can also take advantage of this method to eliminate an atmospheric-pressure gauge and thereby reduce the mass of the instrument: The atmospheric pressure can be calculated from the temperature, the known relative abundance of CO2, and the concentration of CO2 as measured by spectral absorption. Natural CO2 levels on Mars provide an ideal calibration standard. Figure 2 shows a second example of the application of this method to Mars atmospheric gas measurements. For sticky gases like H2O, the method is particularly powerful, since water is notoriously difficult to handle at low concentrations in pre-flight calibration procedures.

  20. Potencial uso de serpentinito no armazenamento mineral do CO2

    Directory of Open Access Journals (Sweden)

    Natacha Alves


    Full Text Available Rising anthropogenic CO2 emissions are considered a major contributor to the greenhouse effect. There are several options for reducing atmospheric CO2 levels, and among these alternatives, Carbon Capture and Storage (CCS has been identified as an effective and promising approach. This work investigated the feasibility of using serpentinite as a vehicle for carbon storage presenting a source-sink match. The main results of the work confirmed that serpentinite is appropriate for the carbonation process due to the high concentration of Mg in its composition.

  1. Anthropogenic CO2 in the ocean

    Directory of Open Access Journals (Sweden)

    Tsung-Hung Peng


    Full Text Available The focus of this review article is on the anthropogenic CO2 taken up by the ocean. There are several methods of identifying the anthropogenic CO2 signal and quantifying its inventory in the ocean. The ?C* method is most frequently used to estimate the global distribution of anthropogenic CO2 in the ocean. Results based on analysis of the dataset obtained from the comprehensive surveys of inorganic carbon distribution in the world oceans in the 1990s are given. These surveys were jointly conducted during the World Ocean Circulation Experiment (WOCE and the Joint Global Ocean Flux Study (JGOFS. This data set consists of 9618 hydrographic stations from a total of 95 cruises, which represents the most accurate and comprehensive view of the distribution of inorganic carbon in the global ocean available today. The increase of anthropogenic CO2 in the ocean during the past few decades is also evaluated using direct comparison of results from repeat surveys and using statistical method of Multi-parameter Linear Regression (MLR. The impact of increasing oceanic anthropogenic CO2 on the calcium carbonate system in the ocean is reviewed briefly as well. Extensive studies of CaCO3 dissolution as a result of increasing anthropogenic CO2 in the ocean have revealed several distinct oceanic regions where the CaCO3 undersaturation zone has expanded.

  2. Density of aqueous solutions of CO2

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Julio E.


    In this report, we present a numerical representation for the partial molar volume of CO2 in water and the calculation of the corresponding aqueous solution density. The motivation behind this work is related to the importance of having accurate representations for aqueous phase properties in the numerical simulation of carbon dioxide disposal into aquifers as well as in geothermal applications. According to reported experimental data the density of aqueous solutions of CO2 can be as much as 2-3% higher than pure water density. This density variation might produce an influence on the groundwater flow regime. For instance, in geologic sequestration of CO2, convective transport mixing might occur when, several years after injection of carbon dioxide has stopped, the CO2-rich gas phase is concentrated at the top of the formation, just below an overlaying caprock. In this particular case the heavier CO2 saturated water will flow downward and will be replaced by water with a lesser CO2 content.

  3. Abatement of CO2 emissions: IFP's solutions

    International Nuclear Information System (INIS)


    In a context of increasing energy consumption and world economic growth, the fight against greenhouse gases has become a major technological challenge for the coming years. The capture and sequestration of CO 2 in the underground is a promising solution in terms of environmental impact, especially in places and sectors characterized by a strong concentration of CO 2 emissions (power generation plants, big industries). However, such a solution requires important R and D efforts to reduce the costs and warrant the long-term reliability of the storage. The French institute of petroleum (IFP) will play an important role in the implementation of the geological sequestration. This press kit comprises 7 documents: a press release from November 4, 2003; a press conference with a series of slides presenting the stakes, solutions and actions proposed by the IFP in collaboration with several foreign partners (CO 2 capture, storage in depleted hydrocarbon deposits, saline aquifers or abandoned coal seams, storage potential, reduction of costs); a summary of the stakes and solutions for CO 2 sequestration in deep underground; a similar document presented at the Panorama 2003 colloquium; the CO 2 constraint in France and in Europe (international consensus on climatic change, Kyoto protocol, European directive about tradable carbon permits, voluntary commitment of companies in the fight against greenhouse effects (AERES)); the European project Castor (CO 2 from capture to storage); and the IFP brochure 'innovating for a sustainable development in the energy domain'. (J.S.)

  4. How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence? (United States)

    Király, Csilla; Szabó, Zsuzsanna; Szamosfalvi, Ágnes; Cseresznyés, Dóra; Király, Edit; Szabó, Csaba; Falus, György


    Carbon Capture and Storage (CCS) is a transitional technology to decrease CO2 emissions from human fossil fuel usage and, therefore, to mitigate climate change. The most important criteria of a CO2 geological storage reservoir is that it must hold the injected CO2 for geological time scales without its significant seepage. The injected CO2 undergoes physical and chemical reactions in the reservoir rocks such as structural-stratigraphic, residual, dissolution or mineral trapping mechanisms. Among these, the safest is the mineral trapping, when carbonate minerals such as calcite, ankerite, siderite, dolomite and dawsonite build the CO2 into their crystal structures. The study of natural CO2 occurrences may help to understand the processes in CO2 reservoirs on geological time scales. This is the reason why the selected, the Mihályi-Répcelak natural CO2 occurrence as our research area, which is able to provide particular and highly significant information for the future of CO2 storage. The area is one of the best known CO2 fields in Central Europe. The main aim of this study is to estimate the amount of CO2 trapped in the mineral phase at Mihályi-Répcelak CO2 reservoirs. For gaining the suitable data, we apply petrographic, major and trace element (microprobe and LA-ICP-MS) and stable isotope analysis (mass spectrometry) and thermodynamic and kinetic geochemical models coded in PHREEQC. Rock and pore water compositions of the same formation, representing the pre-CO2 flooding stages of the Mihályi-Répcelak natural CO2 reservoirs are used in the models. Kinetic rate parameters are derived from the USGS report of Palandri and Kharaka (2004). The results of petrographic analysis show that a significant amount of dawsonite (NaAlCO3(OH)2, max. 16 m/m%) precipitated in the rock due to its reactions with CO2 which flooded the reservoir. This carbonate mineral alone traps about 10-30 kg/m3 of the reservoir rock from the CO2 at Mihályi-Répcelak area, which is an

  5. Warning signs for stabilizing global CO2 emissions (United States)

    Jackson, R. B.; Le Quéré, C.; Andrew, R. M.; Canadell, J. G.; Peters, G. P.; Roy, J.; Wu, L.


    Carbon dioxide (CO2) emissions from fossil fuels and industry comprise ~90% of all CO2 emissions from human activities. For the last three years, such emissions were stable, despite continuing growth in the global economy. Many positive trends contributed to this unique hiatus, including reduced coal use in China and elsewhere, continuing gains in energy efficiency, and a boom in low-carbon renewables such as wind and solar. However, the temporary hiatus appears to have ended in 2017. For 2017, we project emissions growth of 2.0% (range: 0.8%‑3.0%) from 2016 levels (leap-year adjusted), reaching a record 36.8 ± 2 Gt CO2. Economic projections suggest further emissions growth in 2018 is likely. Time is running out on our ability to keep global average temperature increases below 2 °C and, even more immediately, anything close to 1.5 °C.

  6. Atmospheric CO2: Principal Control Knob Governing Earth's Temperature (United States)

    Lacis, Andrew A.; Schmidt, Gavin A.; Rind, David; Ruedy, Reto A.


    Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth s atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Noncondensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO2 and the other noncondensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.

  7. Elevated [CO2] modified the drought acclimation response in peanut (United States)

    Peanut agroecosystems play a key role in food production and are a major source of protein in many arid and semi-arid regions where extreme weather events are expected to increase in frequency. We are taking a systems-level approach to investigate the response of peanut to elevated [CO2], water defi...

  8. A stimulation of an alternative photorespiratory CO2 pathway by ...

    African Journals Online (AJOL)

    ... these responses to nitrogen, suggesting that the observed responses of T. triandra to nitrogen could in part account for its sensitivity to nitrogen inhibition of growth. Keywords: botany; co2; infiltration; inhibition; inhibitors; inorganic nitrogen; leaves; nitrogen; nitrogen levels; photosynthetic rate; plant physiology; productivity; ...

  9. A stimulation of an alternative photorespiratory CO2 pathway by ...

    African Journals Online (AJOL)

    Vacuum infiltration of inorganic nitrogen ions affected the photosynthetic rate and CO2 compensation point of Themeda triandra and Zea mays in a similar way. However these two plants differed markedly in their photorespiratory mechanisms in response to inorganic nitrogen. Increased nitrogen levels in the in vitro reaction ...

  10. CO2-induced seawater acidification affects physiological performance of the marine diatom Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    U. Riebesell


    Full Text Available CO2/pH perturbation experiments were carried out under two different pCO2 levels (39.3 and 101.3 Pa to evaluate effects of CO2-induced ocean acidification on the marine diatom Phaeodactylum tricornutum. After acclimation (>20 generations to ambient and elevated CO2 conditions (with corresponding pH values of 8.15 and 7.80, respectively, growth and photosynthetic carbon fixation rates of high CO2 grown cells were enhanced by 5% and 12%, respectively, and dark respiration stimulated by 34% compared to cells grown at ambient CO2. The half saturation constant (Km for carbon fixation (dissolved inorganic carbon, DIC increased by 20% under the low pH and high CO2 condition, reflecting a decreased affinity for HCO3– or/and CO2 and down-regulated carbon concentrating mechanism (CCM. In the high CO2 grown cells, the electron transport rate from photosystem II (PSII was photoinhibited to a greater extent at high levels of photosynthetically active radiation, while non-photochemical quenching was reduced compared to low CO2 grown cells. This was probably due to the down-regulation of CCM, which serves as a sink for excessive energy. The balance between these positive and negative effects on diatom productivity will be a key factor in determining the net effect of rising atmospheric CO2 on ocean primary production.

  11. Anthropogenic and natural CO2 emission sources in an arid urban environment. (United States)

    Koerner, B; Klopatek, J


    Recent research has shown the Phoenix, AZ metropolitan region to be characterized by a CO2 dome that peaks near the urban center. The CO2 levels, 50% greater than the surrounding non-urban areas, have been attributed to anthropogenic sources and the physical geography of the area. We quantified sources of CO2 emissions across the metropolitan region. Anthropogenic CO2 emission data were obtained from a variety of government and NGO sources. Soil CO2 efflux from the dominant land-use types was measured over the year. Humans and automobile activity produced more than 80% input of CO2 into the urban environment. Soil CO2 efflux from the natural desert ecosystems showed minimal emissions during hot and dry periods, but responded rapidly to moisture. Conversely, human maintained vegetation types (e.g. golf courses, lawns, irrigated agriculture) have greater efflux and are both temperature and soil moisture dependent. Landfills exhibited the most consistent rates, but were temperature and moisture independent. We estimate the annual CO2 released from the predominant land-use types in the Phoenix region and present a graphical portrayal of soil CO2 emissions and the total natural and anthropogenic CO2 emissions in the metropolitan region using a GIS-based approach. The results presented here do not mimic the spatial pattern shown in previous studies. Only, with sophisticated mixing models will we be able to address the total effect of urbanization on CO2 levels and the contribution to regional patterns.

  12. Experimental Ion Mobility measurements in Ne-CO2 and CO2-N2 mixtures

    International Nuclear Information System (INIS)

    Encarnação, P.M.C.C.; Cortez, A.F.V.; Santos, F.P.; Trindade, A.M.F.; Borges, F.I.G.M.; Conde, C.A.N.; Veenhof, R.; Neves, P.N.B.


    In this paper we present the experimental results for the mobility, K 0 , of ions in neon-carbon dioxide (Ne-CO 2 ) and carbon dioxide-nitrogen (CO 2 -N 2 ) gaseous mixtures for total pressures ranging from 8–12 Torr, reduced electric fields in the 10–25 Td range, at room temperature. Regarding the Ne-CO 2 mixture only one peak was observed for CO 2 concentrations above 25%, which has been identified as an ion originated in CO 2 , while below 25% of CO 2 a second-small peak appears at the left side of the main peak, which has been attributed to impurities. The mobility values for the main peak range between 3.51 ± 0.05 and 1.07 ± 0.01 cm 2 V −1 s −1 in the 10%-99% interval of CO 2 , and from 4.61 ± 0.19 to 3.00 ± 0.09 cm 2 V −1 s −1 for the second peak observed (10%–25% of CO 2 ). For the CO 2 -N 2 , the time-of-arrival spectra displayed only one peak for CO 2 concentrations above 10%, which was attributed to ions originated in CO 2 , namely CO 2 + (CO 2 ), with a second peak appearing for CO 2 concentrations below 10%. This second peak, with higher mobility, was attributed to CO 2 + ions. The mobility values of the main peak range between 2.11 ± 0.04 and 1.10 ± 0.03 cm 2 V −1 s −1 in the 1%–99% interval of CO 2 , while the second peak's from 2.26 ± 0.02 and 1.95 ± 0.04 cm 2 V −1 s −1 (1%–10% of CO 2 ). The inverse of the mobility displays an aproximately linear dependence on the CO 2 concentration in the mixture.

  13. Primary, secondary, and tertiary amines for CO2 capture: designing for mesoporous CO2 adsorbents. (United States)

    Ko, Young Gun; Shin, Seung Su; Choi, Ung Su


    CO(2) emissions, from fossil-fuel-burning power plants, the breathing, etc., influence the global worming on large scale and the man's work efficiency on small scale. The reversible capture of CO(2) is a prominent feature of CO(2) organic-inorganic hybrid adsorbent to sequester CO(2). Herein, (3-aminopropyl) trimethoxysilane (APTMS), [3-(methylamino)propyl] trimethoxysilane (MAPTMS), and [3-(diethylamino) propyl] trimethoxysilane (DEAPTMS) are immobilized on highly ordered mesoporous silicas (SBA-15) to catch CO(2) as primary, secondary, and tertiary aminosilica adsorbents. X-ray photoelectron spectroscopy was used to analyze the immobilized APTMS, MAPTMS, and DEAPTMS on the SBA-15. We report an interesting discovery that the CO(2) adsorption and desorption on the adsorbent depend on the amine type of the aminosilica adsorbent. The adsorbed CO(2) was easily desorbed from the adsorbent with the low energy consumption in the order of tertiary, secondary, and primary amino-adsorbents while the adsorption amount and the bonding-affinity increased in the reverse order. The effectiveness of amino-functionalized (1(o), 2(o), and 3(o) amines) SBA-15s as a CO(2) capturing agent was investigated in terms of adsorption capacity, adsorption-desorption kinetics, and thermodynamics. This work demonstrates apt amine types to catch CO(2) and regenerate the adsorbent, which may open new avenues to designing "CO(2) basket". Copyright © 2011. Published by Elsevier Inc.

  14. Modeling CO2 Gas Migration of Shallow Subsurface CO2 Leakage Experiments (United States)

    Porter, M. L.; Plampin, M. R.; Pawar, R.; Illangasekare, T. H.


    Leakage of injected CO2 into shallow subsurface aquifers or back into the atmosphere at geologic carbon sequestration sites is a risk that must be minimized. One potential CO2 leakage pathway involves the transport of dissolved CO2 into a shallow aquifer where the CO2 exsolves, forming a free CO2 gas phase that subsequently migrates through the aquifer. In order to reduce the negative effects of CO2 exsolution, it is important to fully understand each of the processes controlling the movement CO2, as well as the effects of aquifer heterogeneity on the overall fate and transport of CO2. In this work, we present multiphase flow simulations of intermediate scale CO2 exsolution experiments. The multiphase flow simulations were carried out using the Finite Element Heat and Mass Transfer code (FEHM) developed at Los Alamos National Laboratory. Simulations were first designed to model experiments conducted in two different homogeneous packed sands. PEST (Parameter Estimation and Uncertainty Analysis) was used to optimize multiphase flow parameters (i.e., porosity, permeability, relative permeability, and capillary pressure) within FEHM. The optimized parameters were subsequently used to model heterogeneous experiments consisting of various packing configurations using the same sands. Comparisons of CO2 saturation between experiments and simulations will be presented and analyzed.

  15. Six commercially viable ways to remove CO2 from the atmosphere and/or reduce CO2 emissions

    NARCIS (Netherlands)

    Schuiling, O.; de Boer, P.L.


    Background The burning of fossil fuels is the main cause of rising CO2 levels of the atmosphere. This will probably result in climate change. Another consequence is ocean acidification. Although these consequences are not yet proven beyond doubt, the risk of doing nothing is too large. The simplest

  16. Regional CO2 flux estimates for 2009–2010 based on GOSAT and ground-based CO2 observations

    Directory of Open Access Journals (Sweden)

    S. Maksyutov


    Full Text Available We present the application of a global carbon cycle modeling system to the estimation of monthly regional CO2 fluxes from the column-averaged mole fractions of CO2 (XCO2 retrieved from spectral observations made by the Greenhouse gases Observing SATellite (GOSAT. The regional flux estimates are to be publicly disseminated as the GOSAT Level 4 data product. The forward modeling components of the system include an atmospheric tracer transport model, an anthropogenic emissions inventory, a terrestrial biosphere exchange model, and an oceanic flux model. The atmospheric tracer transport was simulated using isentropic coordinates in the stratosphere and was tuned to reproduce the age of air. We used a fossil fuel emission inventory based on large point source data and observations of nighttime lights. The terrestrial biospheric model was optimized by fitting model parameters to observed atmospheric CO2 seasonal cycle, net primary production data, and a biomass distribution map. The oceanic surface pCO2 distribution was estimated with a 4-D variational data assimilation system based on reanalyzed ocean currents. Monthly CO2 fluxes of 64 sub-continental regions, between June 2009 and May 2010, were estimated from GOSAT FTS SWIR Level 2 XCO2 retrievals (ver. 02.00 gridded to 5° × 5° cells and averaged on a monthly basis and monthly-mean GLOBALVIEW-CO2 data. Our result indicated that adding the GOSAT XCO2 retrievals to the GLOBALVIEW data in the flux estimation brings changes to fluxes of tropics and other remote regions where the surface-based data are sparse. The uncertainties of these remote fluxes were reduced by as much as 60% through such addition. Optimized fluxes estimated for many of these regions, were brought closer to the prior fluxes by the addition of the GOSAT retrievals. In most of the regions and seasons considered here, the estimated fluxes fell within the range of natural flux variabilities estimated with the component models.

  17. CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2Geostorage. (United States)

    Iglauer, Stefan


    Carbon geosequestration (CGS) has been identified as a key technology to reduce anthropogenic greenhouse gas emissions and thus significantly mitigate climate change. In CGS, CO 2 is captured from large point-source emitters (e.g., coal fired power stations), purified, and injected deep underground into geological formations for disposal. However, the CO 2 has a lower density than the resident formation brine and thus migrates upward due to buoyancy forces. To prevent the CO 2 from leaking back to the surface, four trapping mechanisms are used: (1) structural trapping (where a tight caprock acts as a seal barrier through which the CO 2 cannot percolate), (2) residual trapping (where the CO 2 plume is split into many micrometer-sized bubbles, which are immobilized by capillary forces in the pore network of the rock), (3) dissolution trapping (where CO 2 dissolves in the formation brine and sinks deep into the reservoir due to a slight increase in brine density), and (4) mineral trapping (where the CO 2 introduced into the subsurface chemically reacts with the formation brine or reservoir rock or both to form solid precipitates). The efficiency of these trapping mechanisms and the movement of CO 2 through the rock are strongly influenced by the CO 2 -brine-rock wettability (mainly due to the small capillary-like pores in the rock which form a complex network), and it is thus of key importance to rigorously understand CO 2 -wettability. In this context, a substantial number of experiments have been conducted from which several conclusions can be drawn: of prime importance is the rock surface chemistry, and hydrophilic surfaces are water-wet while hydrophobic surfaces are CO 2 -wet. Note that CO 2 -wet surfaces dramatically reduce CO 2 storage capacities. Furthermore, increasing pressure, salinity, or dissolved ion valency increases CO 2 -wettability, while the effect of temperature is not well understood. Indeed theoretical understanding of CO 2 -wettability and the

  18. One strategy for estimating the potential soil carbon storage due to CO2 fertilization

    International Nuclear Information System (INIS)

    Harrison, K.G.; Bonani, G.


    Soil radiocarbon measurements can be used to estimate soil carbon turnover rates and inventories. A labile component of soil carbon has the potential to respond to perturbations such as CO 2 fertilization, changing climate, and changing land use. Soil carbon has influenced past and present atmospheric CO 2 levels and will influence future levels. A model is used to calculate the amount of additional carbon stored in soil because of CO 2 fertilization

  19. Propagation Measurements and Comparison with EM Techniques for In-Cabin Wireless Networks

    Directory of Open Access Journals (Sweden)

    Nektarios Moraitis


    Full Text Available This paper presents results of a narrowband measurement campaign conducted inside a Boeing 737–400 aircraft, the objective being the development of a propagation prediction model which can be used in the deployment of in-cabin wireless networks. The measurements were conducted at three different frequency bands: 1.8, 2.1, and 2.45 GHz, representative of several wireless services. Both a simple, empirical, inverse distance power law and a deterministic, site-specific model were investigated. Parameters for the empirical model were extracted from the measurements at different locations inside the cabin: aisle and seats. Additionally, a statistical characterization of the multipath scenario created by the transmitted signal and the various cabin elements is presented. The deterministic model, based on Physical Optics (PO techniques, provides a reasonable match with the empirical results. Finally, measurements and modeling results are provided for the penetration loss into the cabin (or out of the cabin, representative of interference scenarios.

  20. Economic efficiency of CO2 reduction programs

    International Nuclear Information System (INIS)

    Tahvonen, O.; Storch, H. von; Storch, J. von


    A highly simplified time-dependent low-dimensional system has been designed to describe conceptually the interaction of climate and economy. Enhanced emission of carbon dioxide (CO 2 ) is understood as the agent that not only favors instantaneous consumption but also causes unfavorable climate changes at a later time. The problem of balancing these two counterproductive effects of CO 2 emissions on a finite time horizon is considered. The climate system is represented by just two parameters, namely a globally averaged near-surface air-temperature and a globally averaged troposheric CO 2 concentration. The costs of abating CO 2 emissions are monitored by a function which depends quadratically on the percentage reduction of emission compared to an 'uncontrolled emission' scenario. Parameters are fitted to historical climate data and to estimates from studies of CO 2 abatement costs. Two optimization approaches, which differ from earlier attempts to describe the interaction of economy and climate, are discussed. In the 'cost oriented' strategy an optimal emission path is identified which balances the abatement costs and explicitly formulated damage costs. These damage costs, whose estimates are very uncertain, are hypothesized to be a linear function of the time-derivative of temperature. In the 'target oriented' strategy an emission path is chosen so that the abatement costs are minimal while certain restrictions on the terminal temperature and concentration change are met. (orig.)

  1. Rangeland -- plant response to elevated CO2

    International Nuclear Information System (INIS)

    Owensby, C.E.; Coyne, P.I.; Ham, J.M.; Parton, W.; Rice, C.; Auen, L.M.; Adam, N.


    Plots of a tallgrass prairie ecosystem were exposed to ambient and twice-ambient CO 2 concentrations in open-top chambers and compared to unchambered ambient CO 2 plots during the entire growing season from 1989 through 1992. Relative root production among treatments was estimated using root ingrowth bags which remained in place throughout the growing season. Latent heat flux was simulated with and without water stress. Botanical composition was estimated annuallyin all treatments. Open-top chambers appeared to reduce latent heat flux and increase water use efficiency similar to elevated CO 2 when water stress was not severe, but under severe water stress, chamber effect on water use efficiency was limited. In natural ecosystems with periodic moisture stress, increased water use efficiency under elevated CO 2 apparently would have a greater impact on productivity than photosynthetic pathway. Root ingrowth biomass was greater in 1990 and 1991 on elevated CO 2 plots compared to ambient or chambered-ambient plots. In 1992, there was no difference in root ingrowth biomass among treatments

  2. CO2 and CO Simulations and Their Source Signature Indicated by CO/CO2 (United States)

    Kawa, Randy; Huisheng, Bian


    Three years (2000-2002) atmospheric CO2 and CO fields are simulated by a Chemistry Transport Model driven by the assimilated meteorological fields from GEOS-4. The simulated CO2 and CO are evaluated by measurements from surface (CMDL), satellite (MOPITT/CO), and aircraft. The model-observation comparisons indicate reasonable agreement in both source and remote regions, and in the lower and upper troposphere. The simulation also captures the seasonality of CO2 and CO variations. The ratios of CO/CO2 are analyzed over different representative regions to identify the source signature, since the anthropogenic CO comes fiom the same combustion processes as CO2. This work enables us to improve satellite inversion estimates of CO2 sources and sinks by simultaneously using satellite CO measurement.

  3. CO2-Switchable Membranes Prepared by Immobilization of CO2-Breathing Microgels. (United States)

    Zhang, Qi; Wang, Zhenwu; Lei, Lei; Tang, Jun; Wang, Jianli; Zhu, Shiping


    Herein, we report the development of a novel CO 2 -responsive membrane system through immobilization of CO 2 -responsive microgels into commercially available microfiltration membranes using a method of dynamic adsorption. The microgels, prepared from soap-free emulsion polymerization of CO 2 -responsive monomer 2-(diethylamino)ethyl methacrylate (DEA), can be reversibly expanded and shrunken upon CO 2 /N 2 alternation. When incorporated into the membranes, this switching behavior was preserved and further led to transformation between microfiltration and ultrafiltration membranes, as indicated from the dramatic changes on water flux and BSA rejection results. This CO 2 -regulated performance switching of membranes was caused by the changes of water transportation channel, as revealed from the dynamic water contact angle tests and SEM observation. This work represents a simple yet versatile strategy for making CO 2 -responsive membranes.

  4. CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions (United States)

    Engineer, Cawas; Hashimoto-Sugimoto, Mimi; Negi, Juntaro; Israelsson-Nordstrom, Maria; Azoulay-Shemer, Tamar; Rappel, Wouter-Jan; Iba, Koh; Schroeder, Julian


    Guard cells form epidermal stomatal gas exchange valves in plants and regulate the aperture of stomatal pores in response to changes in the carbon dioxide (CO2) concentration in leaves. Moreover, the development of stomata is repressed by elevated CO2 in diverse plant species. Evidence suggests that plants can sense CO2 concentration changes via guard cells and via mesophyll tissues in mediating stomatal movements. We review new discoveries and open questions on mechanisms mediating CO2-regulated stomatal movements and CO2 modulation of stomatal development, which together function in CO2-regulation of stomatal conductance and gas exchange in plants. Research in this area is timely in light of the necessity of selecting and developing crop cultivars which perform better in a shifting climate. PMID:26482956

  5. Analysis of CO2 emissions reduction in the Malaysian transportation sector: An optimisation approach

    International Nuclear Information System (INIS)

    Mustapa, Siti Indati; Bekhet, Hussain Ali


    The demand for transport services is expected to rise, causing the CO 2 emissions level to increase as well. In Malaysia, the transportation sector accounts for 28% of total CO 2 emissions, of which 85% comes from road transport. By 2020, Malaysia is targeting a reduction in CO 2 emissions intensity by up to 40% and in this effort the role of road transport is paramount. This paper attempts to investigate effective policy options that can assist Malaysia in reducing the CO 2 emissions level. An Optimisation model is developed to estimate the potential CO 2 emissions mitigation strategies for road transport by minimising the CO 2 emissions under the constraint of fuel cost and demand travel. Several mitigation strategies have been applied to analyse the effect of CO 2 emissions reduction potential. The results demonstrate that removal of fuel price subsidies can result in reductions of up to 652 ktonnes of fuel consumption and CO 2 emissions can be decreased by 6.55%, which would enable Malaysia to hit its target by 2020. CO 2 emissions can be reduced significantly, up to 20%, by employing a combination of mitigation policies in Malaysia. This suggests that appropriate mitigation policies can assist the country in its quest to achieve the CO 2 emissions reduction target. - Highlights: • An optimisation model for CO 2 emissions reduction in Malaysia's road transport is formulated. • Sensible policy options to achieve the CO 2 emissions reduction target are provided. • Increase in fuel price has induced shift towards fuel efficient vehicles. • The CO 2 emissions can be reduced up to 5.7 MtCO 2 with combination of mitigation policies.

  6. CO2-based hydrogen storage: CO2 hydrogenation to formic acid, formaldehyde and methanol (United States)

    Schaub, Thomas


    The storage of hydrogen via hydrogenation of CO2 to small organic molecules can be attractive for mobile applications. In this article, the state of the art regarding hydrogen storage in Methanol, Formic Acid as well as Formaldehyde and derivates based on CO2 hydrogenation is summarized. The reverse reaction, the release of hydrogen from these molecules is also crucial and described in the articles together with possible concepts for the use of hydrogen storage by CO2 hydrogenation.

  7. Ongoing Relative Performance Evaluation for a CO2 EOR Asset in a Worldwide Peer Group (United States)

    Zhao, C. F.; Li, X. S.; Wang, G. H.; Li, L.


    Abstract. Operators of a CO2 EOR asset need to know the relative performance level of their asset against its peers. The ongoing relative performance evaluation method is appropriate for this purpose. We first choose 52 CO2 assets around the world as the peer group, and then define the four ranking levels in terms of CO2consumption ratio. Only the final values of CO2consumption ratio for the group are obtained, and therefore cannot be used for an ongoing evaluation during a CO2 EOR asset’s life circle. Consequently, numerical reservoir simulation is employed to quantify the process values corresponding to the four ranking levels. Type curve plots are generated on the basis of the process values and utilized for the ongoing relative performance evaluation of a CO2 EOR asset in China.

  8. Effect of relative humidity and temperature control on in-cabin thermal comfort state: Thermodynamic and psychometric analyses

    International Nuclear Information System (INIS)

    Alahmer, A.; Omar, M.A.; Mayyas, A.; Dongri, Shan


    This manuscript discusses the effect of manipulating the Relative Humidity RH of in-cabin environment on the thermal comfort and human occupants' thermal sensation. The study uses thermodynamic and psychometric analyses, to incorporate the effect of changing RH along with the dry bulb temperature on human comfort. Specifically, the study computes the effect of changing the relative humidity on the amount of heat rejected from the passenger compartment and the effect of relative humidity on occupants comfort zone. A practical system implementation is also discussed in terms of an evaporative cooler design. The results show that changing the RH along with dry bulb temperature inside vehicular cabins can improve the air conditioning efficiency by reducing the heat removed while improving the Human comfort sensations as measured by the Predicted Mean Value PMV and the Predicted Percentage Dissatisfied PPD indices. - Highlights: → Investigates the effect of controlling the RH and dry bulb temperature on in-cabin thermal comfort and sensation. → Conducts the thermodynamic and psychometric analyses for changing the RH and temperature for in-cabin air conditioning. → Discusses a possible system implementation through an evaporative cooler design.

  9. Behavior of CO2/water flow in porous media for CO2geological storage. (United States)

    Jiang, Lanlan; Yu, Minghao; Liu, Yu; Yang, Mingjun; Zhang, Yi; Xue, Ziqiu; Suekane, Tetsuya; Song, Yongchen


    A clear understanding of two-phase fluid flow properties in porous media is of importance to CO 2 geological storage. The study visually measured the immiscible and miscible displacement of water by CO 2 using MRI (magnetic resonance imaging), and investigated the factor influencing the displacement process in porous media which were filled with quartz glass beads. For immiscible displacement at slow flow rates, the MR signal intensity of images increased because of CO 2 dissolution; before the dissolution phenomenon became inconspicuous at flow rate of 0.8mLmin -1 . For miscible displacement, the MR signal intensity decreased gradually independent of flow rates, because supercritical CO 2 and water became miscible in the beginning of CO 2 injection. CO 2 channeling or fingering phenomena were more obviously observed with lower permeable porous media. Capillary force decreases with increasing particle size, which would increase permeability and allow CO 2 and water to invade into small pore spaces more easily. The study also showed CO 2 flow patterns were dominated by dimensionless capillary number, changing from capillary finger to stable flow. The relative permeability curve was calculated using Brooks-Corey model, while the results showed the relative permeability of CO 2 slightly decreases with the increase of capillary number. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Effect of Uncertainties in CO2 Property Databases on the S-CO2 Compressor Performance

    International Nuclear Information System (INIS)

    Lee, Je Kyoung; Lee, Jeong Ik; Ahn, Yoonhan; Kim, Seong Gu; Cha, Je Eun


    Various S-CO 2 Brayton cycle experiment facilities are on the state of construction or operation for demonstration of the technology. However, during the data analysis, S-CO 2 property databases are widely used to predict the performance and characteristics of S-CO 2 Brayton cycle. Thus, a reliable property database is very important before any experiment data analyses or calculation. In this paper, deviation of two different property databases which are widely used for the data analysis will be identified by using three selected properties for comparison, C p , density and enthalpy. Furthermore, effect of above mentioned deviation on the analysis of test data will be briefly discussed. From this deviation, results of the test data analysis can have critical error. As the S-CO 2 Brayton cycle researcher knows, CO 2 near the critical point has dramatic change on thermodynamic properties. Thus, it is true that a potential error source of property prediction exists in CO 2 properties near the critical point. During an experiment data analysis with the S-CO 2 Brayton cycle experiment facility, thermodynamic properties are always involved to predict the component performance and characteristics. Thus, construction or defining of precise CO 2 property database should be carried out to develop Korean S-CO 2 Brayton cycle technology

  11. The Abundance of Atmospheric CO_2 in Ocean Exoplanets: a Novel CO_2 Deposition Mechanism

    International Nuclear Information System (INIS)

    Levi, A.; Sasselov, D.; Podolak, M.


    We consider super-Earth sized planets which have a water mass fraction large enough to form an external mantle composed of high-pressure water-ice polymorphs and also lack a substantial H/He atmosphere. We consider such planets in their habitable zone, so that their outermost condensed mantle is a global, deep, liquid ocean. For these ocean planets, we investigate potential internal reservoirs of CO_2, the amount of CO_2 dissolved in the ocean for the various saturation conditions encountered, and the ocean-atmosphere exchange flux of CO_2. We find that, in a steady state, the abundance of CO_2 in the atmosphere has two possible states. When wind-driven circulation is the dominant CO_2 exchange mechanism, an atmosphere of tens of bars of CO_2 results, where the exact value depends on the subtropical ocean surface temperature and the deep ocean temperature. When sea-ice formation, acting on these planets as a CO_2 deposition mechanism, is the dominant exchange mechanism, an atmosphere of a few bars of CO_2 is established. The exact value depends on the subpolar surface temperature. Our results suggest the possibility of a negative feedback mechanism, unique to water planets, where a reduction in the subpolar temperature drives more CO_2 into the atmosphere to increase the greenhouse effect.

  12. CO2 utilization: Developments in conversion processes

    Directory of Open Access Journals (Sweden)

    Erdogan Alper


    The potential utilization of CO2, captured at power plants, should also been taken into consideration for sustainability. This CO2 source, which is potentially a raw material for the chemical industry, will be available at sufficient quality and at gigantic quantity upon realization of on-going tangible capture projects. Products resulting from carboxylation reactions are obvious conversions. In addition, provided that enough supply of energy from non-fossil resources, such as solar [1], is ensured, CO2 reduction reactions can produce several valuable commodity chemicals including multi-carbon compounds, such as ethylene and acrylic acid, in addition to C1 chemicals and polymers. Presently, there are only few developing technologies which can find industrial applications. Therefore, there is a need for concerted research in order to assess the viability of these promising exploratory technologies rationally.

  13. Upscaling of enzyme enhanced CO2 capture

    DEFF Research Database (Denmark)

    Gladis, Arne Berthold

    the mass transfer of CO2 with slow-capturing but energetically favorable solvents can open up a variety of new process options for this technology. The ubiquitous enzyme carbonic anhydrase (CA), which enhances the mass transfer of CO2 in the lungs by catalyzing the reversible hydration of CO2, is one very...... promising mass transfer rate promoter for CCS. This process has been previously been tested successfully in lab scale and in some rare cases in pilot scale, but no validated process model for this technology has been published yet. This PhD thesis presents an investigation of the feasibility of enzyme...... enzyme kinetic model and validating it against in-house pilot plant experiments. The work consisted of identifying a suitable enzyme-solvent system and the ideal process conditions by comparing mass transfer rates of different solvents and enzyme enhanced solvents in a lab scale wetted wall column...

  14. Membraneless water filtration using CO2. (United States)

    Shin, Sangwoo; Shardt, Orest; Warren, Patrick B; Stone, Howard A


    Water purification technologies such as microfiltration/ultrafiltration and reverse osmosis utilize porous membranes to remove suspended particles and solutes. These membranes, however, cause many drawbacks such as a high pumping cost and a need for periodic replacement due to fouling. Here we show an alternative membraneless method for separating suspended particles by exposing the colloidal suspension to CO 2 . Dissolution of CO 2 into the suspension creates solute gradients that drive phoretic motion of particles. Due to the large diffusion potential generated by the dissociation of carbonic acid, colloidal particles move either away from or towards the gas-liquid interface depending on their surface charge. Using the directed motion of particles induced by exposure to CO 2 , we demonstrate a scalable, continuous flow, membraneless particle filtration process that exhibits low energy consumption, three orders of magnitude lower than conventional microfiltration/ultrafiltration processes, and is essentially free from fouling.

  15. Molecular simulations of CO2 at interfaces

    DEFF Research Database (Denmark)

    Silvestri, Alessandro

    . DFT has some advantages over MD in terms of computational cost but MD allows exploration of larger and more complex systems. Dierent options for geologic storage of CO2 have been proposed. Carbonate minerals are ubiquitous, limestone, chalk and marble constitute a signicant fraction of the sedimentary...... rock record and the formations are generally porous so their probable response to CO2 sequestration needs to be investigated. However, despite the large number of geologic sequestration publications on water{rock interactions over the last decade, studies on carbonate reservoirs remain scarce....... Carbonate reservoirs are being considered as CO2 storage sites so more information is needed, for providing data for safety assessment models and for fundamental understanding of the relevant processes and their in uence. Theoretical approaches for the carbonate minerals are even more scarce and only few...

  16. CO2 fluxes near a forest edge

    DEFF Research Database (Denmark)

    Sogachev, Andrey; Leclerc, Monique Y.; Zhang, Gensheng


    the concentration and flux fields against those of a uniform forested surface. We use an atmospheric boundary layer two-equation closure model that accounts for the flow dynamics and vertical divergence of CO2 sources/sinks within a plant canopy. This paper characterizes the spatial variation of CO2 fluxes...... as a function of both sources/sinks distribution and the vertical structure of the canopy. Results suggest that the ground source plays a major role in the formation of wave-like vertical CO2 flux behavior downwind of a forest edge, despite the fact that the contribution of foliage sources/sinks changes...... monotonously. Such a variation is caused by scalar advection in the trunk space and reveals itself as a decrease or increase in vertical fluxes over the forest relative to carbon dioxide exchange of the underlying forest. The effect was more pronounced in model forests where the leaf area is concentrated...

  17. A cost effective CO2 strategy

    DEFF Research Database (Denmark)

    are evaluated according to CO2 reduction potential and according to the ‘shadow price’ on a reduction of one ton CO2. The shadow price reflects the costs (and benefits) of the different measures. Comparing the measures it is possible to identify cost effective measures, but these measures are not necessarily......) between measures are also addressed. It has not been possible to analyse combinations and packages of measures consistently in a model like the on outlined above. However, the obvious connections are addressed and clearly show the limitations with respect to fulfilling the target set by the Kyoto protocol...... national strategies for climate and transport and associated implementation deficits will be discussed, reflecting the presently changing institutional conditions for policy formulation and implementation. The main differences compared to earlier CO2 strategies are the EU ETS and targets set for non...

  18. The ATLAS IBL CO2 Cooling System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237783; The ATLAS collaboration; Zwalinski, L.; Bortolin, C.; Vogt, S.; Godlewski, J.; Crespo-Lopez, O.; Van Overbeek, M.; Blaszcyk, T.


    The ATLAS Pixel detector has been equipped with an extra B-layer in the space obtained by a reduced beam pipe. This new pixel detector called the ATLAS Insertable B-Layer (IBL) is installed in 2014 and is operational in the current ATLAS data taking. The IBL detector is cooled with evaporative CO2 and is the first of its kind in ATLAS. The ATLAS IBL CO2 cooling system is designed for lower temperature operation (<-35⁰C) than the previous developed CO2 cooling systems in High Energy Physics experiments. The cold temperatures are required to protect the pixel sensors for the high expected radiation dose up to 550 fb^-1 integrated luminosity.

  19. Decoupling of CO2 emissions and GDP

    Directory of Open Access Journals (Sweden)

    Yves Rocha de Salles Lima


    Full Text Available The objetive of this work is to analyze the variation of CO2 emissions and GDP per capita throughout the years and identify the possible interaction between them. For this purpose, data from the International Energy Agency was collected on two countries, Brazil and the one with the highest GDP worldwide, the United States. Thus, the results showed that CO2 emissions have been following the country’s economic growth for many years. However, these two indicators have started to decouple in the US in 2007 while in Brazil the same happened in 2011. Furthermore, projections for CO2 emissions are made until 2040, considering 6 probable scenarios. These projections showed that even if the oil price decreases, the emissions will not be significantly affected as long as the economic growth does not decelerate.

  20. Causes of variation among rice models in yield response to CO2 examined with Free-Air CO2 Enrichment and growth chamber experiments. (United States)

    Hasegawa, Toshihiro; Li, Tao; Yin, Xinyou; Zhu, Yan; Boote, Kenneth; Baker, Jeffrey; Bregaglio, Simone; Buis, Samuel; Confalonieri, Roberto; Fugice, Job; Fumoto, Tamon; Gaydon, Donald; Kumar, Soora Naresh; Lafarge, Tanguy; Marcaida Iii, Manuel; Masutomi, Yuji; Nakagawa, Hiroshi; Oriol, Philippe; Ruget, Françoise; Singh, Upendra; Tang, Liang; Tao, Fulu; Wakatsuki, Hitomi; Wallach, Daniel; Wang, Yulong; Wilson, Lloyd Ted; Yang, Lianxin; Yang, Yubin; Yoshida, Hiroe; Zhang, Zhao; Zhu, Jianguo


    The CO 2 fertilization effect is a major source of uncertainty in crop models for future yield forecasts, but coordinated efforts to determine the mechanisms of this uncertainty have been lacking. Here, we studied causes of uncertainty among 16 crop models in predicting rice yield in response to elevated [CO 2 ] (E-[CO 2 ]) by comparison to free-air CO 2 enrichment (FACE) and chamber experiments. The model ensemble reproduced the experimental results well. However, yield prediction in response to E-[CO 2 ] varied significantly among the rice models. The variation was not random: models that overestimated at one experiment simulated greater yield enhancements at the others. The variation was not associated with model structure or magnitude of photosynthetic response to E-[CO 2 ] but was significantly associated with the predictions of leaf area. This suggests that modelled secondary effects of E-[CO 2 ] on morphological development, primarily leaf area, are the sources of model uncertainty. Rice morphological development is conservative to carbon acquisition. Uncertainty will be reduced by incorporating this conservative nature of the morphological response to E-[CO 2 ] into the models. Nitrogen levels, particularly under limited situations, make the prediction more uncertain. Improving models to account for [CO 2 ] × N interactions is necessary to better evaluate management practices under climate change.

  1. Local CO2-induced swelling of shales (United States)

    Pluymakers, Anne; Dysthe, Dag Kristian


    In heterogeneous shale rocks, CO2 adsorbs more strongly to organic matter than to the other components. CO2-induced swelling of organic matter has been shown in coal, which is pure carbon. The heterogeneity of the shale matrix makes an interesting case study. Can local swelling through adsorption of CO2 to organic matter induce strain in the surrounding shale matrix? Can fractures close due to CO2-induced swelling of clays and organic matter? We have developed a new generation of microfluidic high pressure cells (up to 100 bar), which can be used to study flow and adsorption phenomena at the microscale in natural geo-materials. The devices contain one transparent side and a shale sample on the other side. The shale used is the Pomeranian shale, extracted from 4 km depth in Poland. This formation is a potential target of a combined CO2-storage and gas extraction project. To answer the first question, we place the pressure cell under a Veeco NT1100 Interferometer, operated in Vertical Scanning Interferometry mode and equipped with a Through Transmissive Media objective. This allows for observation of local swelling or organic matter with nanometer vertical resolution and micrometer lateral resolution. We expose the sample to CO2 atmospheres at different pressures. Comparison of the interferometry data and using SEM-EDS maps plus optical microscopy delivers local swelling maps where we can distinguish swelling of different mineralogies. Preliminary results indicate minor local swelling of organic matter, where the total amount is both time- and pressure-dependent.

  2. Castration of piglets under CO2-gas anaesthesia. (United States)

    Gerritzen, M A; Kluivers-Poodt, M; Reimert, H G M; Hindle, V; Lambooij, E


    It has become common practice in pig fattening production systems to castrate young boar piglets without the use of anaesthesia. In this study, we examined whether or not CO2 gas is capable of inducing an acceptable anaesthetic state during which castration can be performed. The first step was to identify the most promising CO2/O2 mixture. Based on the results from this first experiment, a mixture of 70% CO2 + 30% O2 was chosen for further investigation as a potential anaesthetic during the castration of young piglets. Thereby, it was established whether the duration and depth of anaesthesia were acceptable for castration where the animal has to be insensible and unconscious. Physiological effects were assessed based on electroencephalogram (EEG) and electrocardiogram (ECG) measurements, blood gas values and behavioural responses. During the induction phase, the only typical behaviour the piglets exhibited when exposed to the 70/30 gas mixture was heavy breathing. All piglets (n = 25) lost consciousness after approximately 30 s according to the EEG. Heart rate decreased slowly during the induction phase, a serious drop occurred when piglets lost their posture. Immediately after this drop, the heart rate neared zero or showed a very irregular pattern. Shortly after loss of posture, most animals showed a few convulsions. None of the animals showed any reaction to castration in behaviour and/or on the EEG and ECG. On average, the piglets recovered within 59 s, i.e. EEG returned to its pre-induction pattern and piglets were able to regain a standing position. After 120 s, heart rate returned to pre-induction levels. In order to explore the usage range of CO2 concentration, 24 piglets were exposed to 60% CO2 + 20% O2 + 20% N2 for up to 30 s after loss of consciousness (as registered on EEG), and castrated after removal from the chamber. Sixteen of the 24 animals showed a reaction to the castration on the EEG. To establish the maximum time piglets survive in 70% CO2 + 30

  3. The CO2 tracer clock for the Tropical Tropopause Layer

    Directory of Open Access Journals (Sweden)

    R.-S. Gao


    Full Text Available Observations of CO2 were made in the upper troposphere and lower stratosphere in the deep tropics in order to determine the patterns of large-scale vertical transport and age of air in the Tropical Tropopause Layer (TTL. Flights aboard the NASA WB-57F aircraft over Central America and adjacent ocean areas took place in January and February, 2004 (Pre-AURA Validation Experiment, Pre-AVE and 2006 (Costa Rice AVE, CR-AVE, and for the same flight dates of 2006, aboard the Proteus aircraft from the surface to 15 km over Darwin, Australia (Tropical Warm Pool International Cloud Experiment, TWP-ICE. The data demonstrate that the TTL is composed of two layers with distinctive features: (1 the lower TTL, 350–360 K (potential temperature(θ; approximately 12–14 km, is subject to inputs of convective outflows, as indicated by layers of variable CO2 concentrations, with air parcels of zero age distributed throughout the layer; (2 the upper TTL, from θ=~360 K to ~390 K (14–18 km, ascends slowly and ages uniformly, as shown by a linear decline in CO2 mixing ratio tightly correlated with altitude, associated with increasing age. This division is confirmed by ensemble trajectory analysis. The CO2 concentration at the level of 360 K was 380.0(±0.2 ppmv, indistinguishable from surface site values in the Intertropical Convergence Zone (ITCZ for the flight dates. Values declined with altitude to 379.2(±0.2 ppmv at 390 K, implying that air in the upper TTL monotonically ages while ascending. In combination with the winter slope of the CO2 seasonal cycle (+10.8±0.4 ppmv/yr, the vertical gradient of –0.78 (±0.09 ppmv gives a mean age of 26(±3 days for the air at 390 K and a mean ascent rate of 1.5(±0.3 mm s−1. The TTL near 360 K in the Southern Hemisphere over Australia is very close in CO2 composition to the TTL in the Northern Hemisphere over Costa Rica, with strong contrasts emerging at lower altitudes (<360 K. Both Pre-AVE and CR-AVE CO2 observed

  4. Kronikken: Handel og handling med CO2

    DEFF Research Database (Denmark)

    Andersen, M. S.


    De fleksible mekanismer i Kyoto-aftalen fortjener indgående overvejelser, ikke kun fordi de giver mulighed for en rabat på CO2-reduktionen, men også fordi de rummer globale og sikkerhedspolitiske dimensioner som er essentielle.......De fleksible mekanismer i Kyoto-aftalen fortjener indgående overvejelser, ikke kun fordi de giver mulighed for en rabat på CO2-reduktionen, men også fordi de rummer globale og sikkerhedspolitiske dimensioner som er essentielle....

  5. Modelling the Martian CO2 Ice Clouds (United States)

    Listowski, Constantino; Määttänen, A.; Montmessin, F.; Lefèvre, F.


    Martian CO2 ice cloud formation represents a rare phenomenon in the Solar System: the condensation of the main component of the atmosphere. Moreover, on Mars, condensation occurs in a rarefied atmosphere (large Knudsen numbers, Kn) that limits the growth efficiency. These clouds form in the polar winter troposphere and in the mesosphere near the equator. CO2 ice cloud modeling has turned out to be challenging: recent efforts (e.g. [1]) fail in explaining typical small sizes (80 nm-130 nm) observed for mesospheric clouds [2]. Supercold pockets (TWood, S. E., (1999), Ph.D. thesis, UCLA [6] Young, J. B., J. Geophys. Res., 36, 294-2956, 1993

  6. Acute physiological impacts of CO2 ocean sequestration on marine animals

    International Nuclear Information System (INIS)

    Ishimatsu, A.; Hayashi, M.; Lee, K.S.; Murata, K.; Kumagai, E.


    The biological impacts of ocean carbon dioxide (CO 2 ) sequestration must be carefully considered before it is implemented as a mitigation strategy. This paper presented details of a study investigating the effects of high CO 2 concentrations on marine fish, lobster, and octopus. The influence of water temperature on the physiological effects of CO 2 was also discussed. In the first part of the study, eggs and larvae of red seabream were exposed to both CO 2 and HCI-acidified seawater at identical pH levels. Seabream in the CO 2 group showed a much higher mortality rate than fish in the HCI group. Other tests showed that Japanese Flounder died after complete recovery of pH in seawater equilibrated with 5 per cent CO 2 . Cardiac output was rapidly depressed in Yellowtail fish without significant changes in blood oxygen concentrations. Lower temperatures resulted in higher mortality and delayed pH recovery during hypercapnia in all fish. Western rock lobsters were the most tolerant to CO 2 among all species tested. The recovery of hemolymph pH was complete at exposure to CO 2 concentrations of 1 per cent. Changes in hemolymph bicarbonate concentrations indicated that acid-based regulatory mechanisms differed between fish and lobsters. Mortality rates for octopus were significant at CO 2 concentrations of 1 per cent. The results of all tests showed that aquatic animals are more susceptible to increases in ambient CO 2 levels than terrestrial animals. It was concluded that even slight elevations in CO 2 concentration levels adversely affected physiological functioning in the tested species. It was concluded that CO 2 sequestration in deeper, colder waters will have a more pronounced effect on aquatic animals due to the interactions between CO 2 and lower temperatures, as well as the fact that most deep-sea fish are less tolerant to environmental perturbations. 3 refs., 1 tab., 3 figs

  7. Neonatal maturation of the hypercapnic ventilatory response and central neural CO2 chemosensitivity. (United States)

    Putnam, Robert W; Conrad, Susan C; Gdovin, M J; Erlichman, Joseph S; Leiter, J C


    The ventilatory response to CO2 changes as a function of neonatal development. In rats, a ventilatory response to CO2 is present in the first 5 days of life, but this ventilatory response to CO2 wanes and reaches its lowest point around postnatal day 8. Subsequently, the ventilatory response to CO2 rises towards adult levels. Similar patterns in the ventilatory response to CO2 are seen in some other species, although some animals do not exhibit all of these phases. Different developmental patterns of the ventilatory response to CO2 may be related to the state of development of the animal at birth. The triphasic pattern of responsiveness (early decline, a nadir, and subsequent achievement of adult levels of responsiveness) may arise from the development of several processes, including central neural mechanisms, gas exchange, the neuromuscular junction, respiratory muscles and respiratory mechanics. We only discuss central neural mechanisms here, including altered CO2 sensitivity of neurons among the various sites of central CO2 chemosensitivity, changes in astrocytic function during development, the maturation of electrical and chemical synaptic mechanisms (both inhibitory and excitatory mechanisms) or changes in the integration of chemosensory information originating from peripheral and multiple central CO2 chemosensory sites. Among these central processes, the maturation of synaptic mechanisms seems most important and the relative maturation of synaptic processes may also determine how plastic the response to CO2 is at any particular age.

  8. Capture and Geological Storage of CO2

    International Nuclear Information System (INIS)

    Kerr, T.; Brockett, S.; Hegan, L.; Barbucci, P.; Tullius, K.; Scott, J.; Otter, N.; Cook, P.; Hill, G.; Dino, R.; Aimard, N.; Giese, R.; Christensen, N.P.; Munier, G.; Paelinck, Ph.; Rayna, L.; Stromberg, L.; Birat, J.P.; Audigane, P.; Loizzo, M.; Arts, R.; Fabriol, H.; Radgen, P.; Hartwell, J.; Wartmann, S.; Drosin, E.; Willnow, K.; Moisan, F.


    To build on the growing success of the first two international symposia on emission reduction and CO 2 capture and geological storage, held in Paris in 2005 and again in 2007, IFP, ADEME and BRGM organised a third event on the same topic the 5-6 November 2009. This time, the focus was on the urgency of industrial deployment. Indeed, the IPCC 4. assessment report indicates that the world must achieve a 50 to 85% reduction in CO 2 emissions by 2050 compared to 2000, in order to limit the global temperature increase to around 2 deg. C. Moreover, IPCC stresses that a 'business as usual' scenario could lead to a temperature increase of between 4 deg. C to 7 deg. C across the planet. The symposium was organized in 4 sessions: Session I - Regulatory framework and strategies for enabling CCS deployment: - CCS: international status of political, regulatory and financing issues (Tom Kerr, IEA); - EC regulatory framework (Scott Brockett, European Commission, DG ENV); - Canada's investments towards implementation of CCS in Canada (Larry Hegan, Office of Energy Research and Development - Government of Canada); - A power company perspective (Pietro Barbucci, ENEL); - EC CCS demonstration network (Kai Tullius, European Commission, DG TREN); - Strategies and policies for accelerating global CCS deployment (Jesse Scott, E3G); - The global CCS Institute, a major initiative to facilitate the rapid deployment of CCS (Nick Otter, GCCSI); Session II - From pilot to demonstration projects: - Otway project, Australia (David Hilditch, CO2 CRC); - US regional partnerships (Gerald Hill, Southeast Regional Carbon Sequestration Partnership - SECARB); - CCS activities in Brazil (Rodolfo Dino, Petrobras); - Lessons learnt from Ketzin CO2Sink project in Germany (Ruediger Giese, GFZ); - CO 2 storage - from laboratory to reality (Niels-Peter Christensen, Vattenfall); - Valuation and storage of CO 2 : A global project for carbon management in South-East France (Gilles Munier, Geogreen); Session III

  9. Future ocean hypercapnia driven by anthropogenic amplification of the natural CO2 cycle. (United States)

    McNeil, Ben I; Sasse, Tristan P


    High carbon dioxide (CO2) concentrations in sea-water (ocean hypercapnia) can induce neurological, physiological and behavioural deficiencies in marine animals. Prediction of the onset and evolution of hypercapnia in the ocean requires a good understanding of annual variations in oceanic CO2 concentration, but there is a lack of relevant global observational data. Here we identify global ocean patterns of monthly variability in carbon concentration using observations that allow us to examine the evolution of surface-ocean CO2 levels over the entire annual cycle under increasing atmospheric CO2 concentrations. We predict that the present-day amplitude of the natural oscillations in oceanic CO2 concentration will be amplified by up to tenfold in some regions by 2100, if atmospheric CO2 concentrations continue to rise throughout this century (according to the RCP8.5 scenario of the Intergovernmental Panel on Climate Change). The findings from our data are broadly consistent with projections from Earth system climate models. Our predicted amplification of the annual CO2 cycle displays distinct global patterns that may expose major fisheries in the Southern, Pacific and North Atlantic oceans to hypercapnia many decades earlier than is expected from average atmospheric CO2 concentrations. We suggest that these ocean 'CO2 hotspots' evolve as a combination of the strong seasonal dynamics of CO2 concentration and the long-term effective storage of anthropogenic CO2 in the oceans that lowers the buffer capacity in these regions, causing a nonlinear amplification of CO2 concentration over the annual cycle. The onset of ocean hypercapnia (when the partial pressure of CO2 in sea-water exceeds 1,000 micro-atmospheres) is forecast for atmospheric CO2 concentrations that exceed 650 parts per million, with hypercapnia expected in up to half the surface ocean by 2100, assuming a high-emissions scenario (RCP8.5). Such extensive ocean hypercapnia has detrimental implications for

  10. First direct observation of the atmospheric CO2 year-to-year increase from space

    Directory of Open Access Journals (Sweden)

    M. Reuter


    Full Text Available The reliable prediction of future atmospheric CO2 concentrations and associated global climate change requires an adequate understanding of the CO2 sources and sinks. The sparseness of the existing surface measurement network limits current knowledge about the global distribution of CO2 surface fluxes. The retrieval of CO2 total vertical columns from satellite observations is predicted to improve this situation. Such an application however requires very high accuracy and precision. We report on retrievals of the column-averaged CO2 dry air mole fraction, denoted XCO2, from the near-infrared nadir spectral radiance and solar irradiance measurements of the SCIAMACHY satellite instrument between 2003 and 2005. We focus on northern hemispheric large scale CO2 features such as the CO2 seasonal cycle and show - for the first time - that the atmospheric annual increase of CO2 can be directly observed using satellite measurements of the CO2 total column. The satellite retrievals are compared with global XCO2 obtained from NOAA's CO2 assimilation system CarbonTracker taking into account the spatio-temporal sampling and altitude sensitivity of the satellite data. We show that the measured CO2 year-to-year increase agrees within about 1 ppm/year with CarbonTracker. We also show that the latitude dependent amplitude of the northern hemispheric CO2 seasonal cycle agrees with CarbonTracker within about 2 ppm with the retrieved amplitude being systematically larger. The analysis demonstrates that it is possible using satellite measurements of the CO2 total column to retrieve information on the atmospheric CO2 on the level of a few parts per million.

  11. CO2 convective dissolution controlled by temporal changes in free-phase CO2 properties (United States)

    Jafari Raad, S. M.; Emami-Meybodi, H.; Hassanzadeh, H.


    Understanding the factors that control CO2 convective dissolution, which is one of the permanent trapping mechanisms, in the deep saline aquifer is crucial in the long-term fate of the injected CO2. The present study investigates the effects of temporal changes in the solubility of CO2 at the free-phase CO2/brine interface on the onset of natural convection and the subsequent convective mixing by conducting linear stability analyses (LSA) and direct numerical simulations (DNS). A time-dependent concentration boundary is considered for the free-phase CO2/brine interface where the CO2 concentration first decreases with the time and then remains constant. The LSA results show that the temporal variation in the concentration increases the onset of natural convection up to two orders of magnitude. In addition, the critical Rayleigh number significantly increases as CO2 concentration decreases. In other words, size and pressure of the injected CO2 affect the commencement of convective mixing. Based on LSA results, several scaling relations are proposed to correlate critical Rayleigh number, critical time, and its corresponding wavenumbers with time-dependent boundary's parameters, such as concentration decline rate and equilibrium concentration ratio. The DNS results reveal that the convective fingering patterns are significantly influenced by the variation of CO2 concentration at the interface. These findings improve our understanding of CO2 solubility trapping and are particularly important in estimation of potential storage capacity, risk assessment, and storage sites characterization and screening. Keywords: CO2 sequestration; natural convection; solubility trapping; time-dependent boundary condition; numerical simulation; stability analysis

  12. CO2 induced growth response in a diatom dominated phytoplankton community from SW Bay of Bengal coastal water (United States)

    Biswas, Haimanti; Shaik, Aziz Ur Rahman; Bandyopadhyay, Debasmita; Chowdhury, Neha


    The ongoing increase in surface seawater CO2 level could potentially impact phytoplankton primary production in coastal waters; however, CO2 sensitivity studies on tropical coastal phytoplankton assemblages are rare. The present study investigated the interactive impacts of variable CO2 level, light and zinc (Zn) addition on the diatom dominated phytoplankton assemblages from the western coastal Bay of Bengal. Increased CO2 supply enhanced particulate organic matter (POC) production; a concomitant depletion in δ13CPOM values at elevated CO2 suggested increased CO2 diffusive influx inside the cell. Trace amount of Zn added under low CO2 level accelerated growth probably by accelerating Zn-Carbonic Anhydrase activity which helps in converting bicarbonate ion to CO2. Almost identical values of δ13CPOM in the low CO2 treated cells grown with and without Zn indicated a low discrimination between 13C and 12C probably due to bicarbonate uptake. These evidences collectively indicated the existence of the carbon concentration mechanisms (CCMs) at low CO2. A minimum growth rate was observed at low CO2 and light limited condition indicating light dependence of CCMs activity. Upon the increase of light and CO2 level, growth response was maximum. The cells grown in the low CO2 levels showed higher light stress (higher values of both diatoxanthin index and the ratio of photo-protective to light-harvesting pigments) that was alleviated by both increasing CO2 supply and Zn addition (probably by efficient light energy utilization in presence of adequate CO2). This is likely that the diatom dominated phytoplankton communities benefited from the increasing CO2 supply and thus may enhance primary production in response to any further increase in coastal water CO2 levels and can have large biogeochemical consequences in the study area.

  13. Seasonal and spatial variations in surface pCO2 and air-sea CO2 flux in the Chesapeake Bay (United States)

    Cai, W. J.; Chen, B.


    Bay-wide observations of surface water partial pressure of carbon dioxide (pCO2) were conducted in May, June, August, and October 2016 to study the spatial and seasonal variations in surface pCO2 and to estimate air-sea CO2 flux in the Chesapeake Bay. Overall, high surface pCO2 in the upper-bay decreased downstream rapidly below the atmospheric value near the bay bridge in the mid-bay and then increased slightly to the lower-bay where pCO2 approached the atmospheric level. Over the course of a year, pCO2 was higher than 1000 µatm in the upper bay and the highest pCO2 (2500 µatm) was observed in August. Significant biologically-induced pCO2 undersaturation was observed at the upper part of the mid-bay in August with pCO2 as low as 50 µatm and oversaturated DO% of 200%. In addition to biological control, vertical mixing and upwelling controlled by wind direction and tidal stage played an important role in controlling surface pCO2 in the mid-bay as is evidenced by co-occurrence of high pCO2 with low temperature and low oxygen or high salinity from the subsurface. These physical processes occurred regularly and in short time scale of hours, suggesting they must be considered in the assessment of annual air-sea CO2 flux. Seasonally, the upper-bay acted as a source for atmospheric CO2 over the course of a year. The boundary of upper and mid bay transited from a CO2 source to a sink from May to August and was a source again in October due to strong biological production in summer. In contrast, the mid-bay represented as a CO2 source with large temporal variation due to dynamic hydrographic settings. The lower-bay transited from a weak sink in May to equilibrated with the atmosphere from June to August, while became a source again in October. Moreover, the CO2 flux could be reversed very quickly under episodic severe weather events. Thus further research, including the influence of severe weather and subsequent bloom, is needed to get better understanding of the carbon

  14. Response of ocean acidification to a gradual increase and decrease of atmospheric CO2

    International Nuclear Information System (INIS)

    Cao, Long; Zhang, Han; Zheng, Meidi; Wang, Shuangjing


    We perform coupled climate–carbon cycle model simulations to examine changes in ocean acidity in response to idealized change of atmospheric CO 2 . Atmospheric CO 2 increases at a rate of 1% per year to four times its pre-industrial level of 280 ppm and then decreases at the same rate to the pre-industrial level. Our simulations show that changes in surface ocean chemistry largely follow changes in atmospheric CO 2 . However, changes in deep ocean chemistry in general lag behind the change in atmospheric CO 2 because of the long time scale associated with the penetration of excess CO 2 into the deep ocean. In our simulations with the effect of climate change, when atmospheric CO 2 reaches four times its pre-industrial level, global mean aragonite saturation horizon (ASH) shoals from the pre-industrial value of 1288 to 143 m. When atmospheric CO 2 returns from the peak value of 1120 ppm to pre-industrial level, ASH is 630 m, which is approximately the value of ASH when atmospheric CO 2 first increases to 719 ppm. At pre-industrial CO 2 9% deep-sea cold-water corals are surrounded by seawater that is undersaturated with aragonite. When atmospheric CO 2 reaches 1120 ppm, 73% cold-water coral locations are surrounded by seawater with aragonite undersaturation, and when atmospheric CO 2 returns to the pre-industrial level, 18% cold-water coral locations are surrounded by seawater with aragonite undersaturation. Our analysis indicates the difficulty for some marine ecosystems to recover to their natural chemical habitats even if atmospheric CO 2 content can be lowered in the future. (paper)

  15. Elevated-CO2 Response of Stomata and Its Dependence on Environmental Factors (United States)

    Xu, Zhenzhu; Jiang, Yanling; Jia, Bingrui; Zhou, Guangsheng


    Stomata control the flow of gases between plants and the atmosphere. This review is centered on stomatal responses to elevated CO2 concentration and considers other key environmental factors and underlying mechanisms at multiple levels. First, an outline of general responses in stomatal conductance under elevated CO2 is presented. Second, stomatal density response, its development, and the trade-off with leaf growth under elevated CO2 conditions are depicted. Third, the molecular mechanism regulating guard cell movement at elevated CO2 is suggested. Finally, the interactive effects of elevated CO2 with other factors critical to stomatal behavior are reviewed. It may be useful to better understand how stomata respond to elevated CO2 levels while considering other key environmental factors and mechanisms, including molecular mechanism, biochemical processes, and ecophysiological regulation. This understanding may provide profound new insights into how plants cope with climate change. PMID:27242858

  16. Acclimation to high CO2 in maize is related to water status and dependent on leaf rank. (United States)

    Prins, Anneke; Mukubi, Josephine Muchwesi; Pellny, Till K; Verrier, Paul J; Beyene, Getu; Lopes, Marta Silva; Emami, Kaveh; Treumann, Achim; Lelarge-Trouverie, Caroline; Noctor, Graham; Kunert, Karl J; Kerchev, Pavel; Foyer, Christine H


    The responses of C(3) plants to rising atmospheric CO(2) levels are considered to be largely dependent on effects exerted through altered photosynthesis. In contrast, the nature of the responses of C(4) plants to high CO(2) remains controversial because of the absence of CO(2) -dependent effects on photosynthesis. In this study, the effects of atmospheric CO(2) availability on the transcriptome, proteome and metabolome profiles of two ranks of source leaves in maize (Zea mays L.) were studied in plants grown under ambient CO(2) conditions (350 +/- 20 µL L(-1) CO(2) ) or with CO(2) enrichment (700 +/- 20 µL L(-1) CO(2) ). Growth at high CO(2) had no effect on photosynthesis, photorespiration, leaf C/N ratios or anthocyanin contents. However, leaf transpiration rates, carbohydrate metabolism and protein carbonyl accumulation were altered at high CO(2) in a leaf-rank specific manner. Although no significant CO(2) -dependent changes in the leaf transcriptome were observed, qPCR analysis revealed that the abundance of transcripts encoding a Bowman-Birk protease inhibitor and a serpin were changed by the growth CO(2) level in a leaf rank specific manner. Moreover, CO(2) -dependent changes in the leaf proteome were most evident in the oldest source leaves. Small changes in water status may be responsible for the observed responses to high CO(2,) particularly in the older leaf ranks. © 2010 Blackwell Publishing Ltd.

  17. Ocean acidification effects on calcification in pCO2 acclimated Caribbean scleractinian coral (United States)

    Ocean acidification (OA) is projected to increase the acidity of coral reef habitats 2-3 times that of present day pCO2 levels. Many studies have shown the adverse effects on scleractinian calcification when exposed to elevated pCO2 levels, however, in these studies, corals have ...

  18. Plasma Arc Augmented CO2 laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels


    In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...

  19. Chilled ammonia process for CO2 capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; van Well, Willy J. M


    The chilled ammonia process absorbs the CO2 at low temperature (2-10 degrees C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows...

  20. Chilled Ammonia Process for CO2 Capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; Well, Willy J.M. van


    The chilled ammonia process absorbs the CO2 at low temperature (2–10°C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows good...

  1. Artificial photosynthesis - CO2 towards methanol (United States)

    Nazimek, D.; Czech, B.


    The new insight into the problem of carbon dioxide utilization into valuable compound - methanol and then its transformation into fuel is presented. Because the highly endothermic requirements of the reaction of CO2 hydrogenation a photocatalytic route is applied. Combining of the two reactions: water splitting and CO2 hydrogenation using H2O as a source of hydrogen at the same time and place are proposed. The studies over modified TiO2 catalysts supported on Al2O3 were conducted in a self-designed circulated photocatalytic reaction system under at room temperature and constant pressure. Experimental results indicated that the highest yield of the photoreduction of CO2 with H2O were obtained using TiO2 with the active anatase phase modified by Ru and WO3 addition. The conversion was very high - almost 97% of CO2 was transformed mainly into methanol (14%vol.) and into small amount of formic and acetic acid and ester.

  2. Harvesting Energy from CO2 Emissions

    NARCIS (Netherlands)

    Hamelers, H.V.M.; Schaetzle, O.; Paz-García, J.M.; Biesheuvel, P.M.; Buisman, C.J.N.


    When two fluids with different compositions are mixed, mixing energy is released. This holds true for both liquids and gases, though in the case of gases, no technology is yet available to harvest this energy source. Mixing the CO2 in combustion gases with air represents a source of energy with a

  3. Carbon dioxide (CO2) utilizing strain database

    African Journals Online (AJOL)



    Oct 17, 2011 ... CSD can be used to gain information related to CO2 fixing microbes. It can also contribute to devising biological strategies for reducing carbon dioxide from the environment. It introduces an innovative idea of exploring the potential of these bacterial strains for reversing global warming. The CSD can be.

  4. Climate change and CO2 emission reductions

    International Nuclear Information System (INIS)

    Ha Duong, M.; Campos, A.S.


    This paper presents the results of an opinion poll performed on a representative sample of 1000 persons about their sensitivity to climate change and to environment protection, their knowledge about technologies which are useful for environment protection, their opinion about geological CO 2 sequestration, and technologies to be developed to struggle against climate warming

  5. CO2 laser used in cosmetology (United States)

    Su, Chenglie


    Cases of various kinds of warts, nevi, papillomas, skin angiomas, ephilises, skin vegetation, scars and brandy noses were vaporized and solidified with a 2.5 - 8 W low power CO2 laser with an overall satisfaction rate up to 99.8% and the satisfaction rate for one time 92%.

  6. CO2 laser in stapes surgery (United States)

    Jovanovic, Sergije; Schoenfeld, Uwe; Berghaus, Andreas; Fischer, R.; Scherer, Hans H.


    Stapedotomy is not only one of the most successful interventions in otology but also one of the most dangerous for the inner ear. To reduce the risk of damaging middle and inner ear structures through manipulations with conventional instruments, the CO2 laser beam is used for perforating the footplate and removing the suprastructures. This non-contact technique aims at precise and controlled management of middle ear structures. Consideration is given to the impact of experimental data on the clinical application of the CO2 laser in stapes surgery. The discussion covers the advantages and disadvantages with regard to optical and tissue-related properties and points out possible dangers to the inner ear. Our experimental and clinical experience is taken as a basis for examining the surgical technique and the varying demands made on the laser beam in treating the stapedial tendon, crura and footplate. Attention is called to the need for additional instruments. Effective energy parameters for CO2 laser stapedeotomy are evaluated for different lasers. Application of the CO2 laser contributes towards optimization of this high-precision intervention and promises to reduce the incidence of inner ear damages in large numbers of cases. This technique appears useful particularly in difficult anatomic situations and, above all, for revisional operations.

  7. Managing CO2 emissions in Nigeria

    International Nuclear Information System (INIS)

    Obioh, I.B.; Oluwole, A.F.; Akeredolu, F.A.


    The energy resources in Nigeria are nearly equally divided between fossil fuels and biofuels. The increasing pressure on them, following expected increased population growth, may lead to substantial emissions of carbon into the atmosphere. Additionally agricultural and forestry management practices in vogue are those related to savannah burning and rotational bush fallow systems, which have been clearly implicated as important sources of CO 2 and trace gases. An integrated model for the prediction of future CO 2 emissions based on fossil fuels and biomass fuels requirements, rates of deforestation and other land-use indices is presented. This is further based on trends in population and economic growth up to the year 2025, with a base year in 1988. A coupled carbon cycle-climate model based on the contribution of CO 2 and other trace gases is established from the proportions of integrated global warming effects for a 20-year averaging time using the product of global warming potential (GWP) and total emissions. An energy-technology inventory approach to optimal resources management is used as a tool for establishing the future scope of reducing the CO 2 emissions through improved fossil fuel energy efficiencies. Scenarios for reduction based on gradual to swift shifts from biomass to fossil and renewable fuels are presented together with expected policy options required to effect them

  8. Detection of 14CO2 in radiotoxicology

    International Nuclear Information System (INIS)

    Simonnet, Francoise; Bocquet, Colette.


    14 CO 2 is detected in exhaled air by conversion to Ba 14 CO 3 which is then filtered, dried and weighed. The radioactivity is measured by liquid scintillation counting. The radioactivity is expressed in μCi per litre of exhaled air according to the ICRP recommendations. The detection threshold is well below the values indicated by the ICRP [fr

  9. Stereotactic CO2 laser therapy for hydrocephalus (United States)

    Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.


    A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

  10. Heterotrophic fixation of CO2 in soil

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Bird, M. I.; Elhottová, Dana; Novák, Jaroslav; Picek, T.; Šimek, Miloslav; Tykva, Richard


    Roč. 49, č. 2 (2005), s. 218-225 ISSN 0095-3628 R&D Projects: GA ČR(CZ) GA206/02/1036; GA AV ČR(CZ) IAA6066901 Institutional research plan: CEZ:AV0Z60660521 Keywords : heterotrophic fixation * CO2 * soil Subject RIV: EH - Ecology, Behaviour Impact factor: 2.674, year: 2005

  11. CO2 Capture by Cement Raw Meal

    DEFF Research Database (Denmark)

    Pathi, Sharat Kumar; Lin, Weigang; Illerup, Jytte Boll


    , the capacity of synthetic raw meal was similar to that of pure limestone, whereas at 950 °C in N2 and in a CO2-rich atmosphere there was a significant difference. The SEM and BET analyses indicate that sintering is the main reason for the lower capture capacity of the limestone in the raw meal. The main...


    Directory of Open Access Journals (Sweden)

    Cleyzer Adrian Cunha


    Full Text Available The objective of paper is verifying empirically the relationship between GDP per capita and CO2 emissions in Brazil in the period 1980-2006. The scope of work was limited to this natural resource due to its role in economic activity, as an important input in the production process in the Brazilian energy matrix. Among the main results is that there is a long-term relationship and simultaneous causality between variables and GDP per capita CO2 emissions. This evidence, coupled with the fact that the series used were not stationary in level, impossible to estimate the Environmental Kuznets Curve (EKC, which is the main theoretical basis used in empirical work related to the theme. The VAR / VEC has been estimated and found elasticity between economic growth and CO2 emission was 7.32, ie, in the long run, we can infer that an increase of 1% in GDP per capita increases by 7, 32% CO2 emissions.

  13. Fabry-Perot Interferometer for Column CO2 (United States)

    Heaps, William S.; Kawa, Randolph; Bhartia, P. K. (Technical Monitor)


    Global atmospheric CO2 measurements are essential to resolving significant discrepancies in our understanding of the global carbon budget and, hence, humankind's role in global climate change. The science measurement requirements for CO2 are extremely demanding (precision approx. 0.3%). No atmospheric chemical species has ever been measured from space with this precision. We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere. Preliminary design studies indicate that the method will be able to achieve the sensitivity and signal-to-noise detection required to measure column CO2 at the target specification. The objective of this program is to construct a prototype instrument for deployment on an aircraft to test the instrument performance and our ability to retrieve the data in the real atmosphere. To date we have assembled a laboratory bench system to begin testing the optical and electronic components. We are also measuring signal and noise levels in actual sunlight to evaluate component performance.

  14. Choosing amine-based absorbents for CO2 capture. (United States)

    Gomes, João; Santos, Samuel; Bordado, João


    CO2 capture from gaseous effluents is one of the great challenges faced by chemical and environmental engineers, as the increase in CO2 levels in the Earth atmosphere might be responsible for dramatic climate changes. From the existing capture technologies, the only proven and mature technology is chemical absorption using aqueous amine solutions. However, bearing in mind that this process is somewhat expensive, it is important to choose the most efficient and, at the same time, the least expensive solvents. For this purpose, a pilot test facility was assembled and includes an absorption column, as well as a stripping column, a heat exchanger between the two columns, a reboiler for the stripping column, pumping systems, surge tanks and all necessary instrumentation and control systems. Some different aquous amine solutions were tested on this facility and it was found that, from a set of six tested amines, diethanol amine is the one that turned out to be the most economical choice, as it showed a higher CO2 loading capacity (0.982 mol of CO2 per mol of amine) and the lowest price per litre (25.70 €/L), even when compared with monoethanolamine, the benchmark solvent, exhibiting a price per litre of 30.50 €/L.

  15. Formation and decomposition of siderite for CO2 treatment (United States)

    Y Mora, E.; Sarmiento, A.; Vera, E.; Drozd, V.; Durigyn, A.; Saxena, S.


    In this research work, we studied the conditions for formation and decomposition of siderite FeCO3 from hematite Fe2O3 along with carbon dioxide CO2 at suitable thermodynamic conditions. As reductant agents were used mixtures of two elements, metallic iron and graphite. Best levels of carbonation were found in mixtures with bigger amounts of metallic iron. It was demonstrated that CO2 capture capacity by hematite depends of temperature, CO2 pressure, and reaction time. Temperatures between 100 and 150°C, pressures between 10 and 30bar and reaction times between 1 and 4h were adjusted for analyse the carbonation behaviour; siderite formation was improved by increases of these three variables. There was no carbonation without water in the mixtures, due to kinetic limitations. CO2 capture capacity was calculated from Rietveld refinement results. Using vacuum system and Dielectric Barrier Discharge, DBD plasma, the siderite was decomposed at 300°C, and 320°C respectively. Techniques as X-ray diffraction, and surface area analysis were employed to study the material.

  16. Costs of mitigating CO2 emissions from passenger aircraft (United States)

    Schäfer, Andreas W.; Evans, Antony D.; Reynolds, Tom G.; Dray, Lynnette


    In response to strong growth in air transportation CO2 emissions, governments and industry began to explore and implement mitigation measures and targets in the early 2000s. However, in the absence of rigorous analyses assessing the costs for mitigating CO2 emissions, these policies could be economically wasteful. Here we identify the cost-effectiveness of CO2 emission reductions from narrow-body aircraft, the workhorse of passenger air transportation. We find that in the US, a combination of fuel burn reduction strategies could reduce the 2012 level of life cycle CO2 emissions per passenger kilometre by around 2% per year to mid-century. These intensity reductions would occur at zero marginal costs for oil prices between US$50-100 per barrel. Even larger reductions are possible, but could impose extra costs and require the adoption of biomass-based synthetic fuels. The extent to which these intensity reductions will translate into absolute emissions reductions will depend on fleet growth.

  17. Influence of trade on national CO2 emissions

    International Nuclear Information System (INIS)

    Munksgaard, Jesper; Pade, Lise-Lotte; Minx, Jan; Lenzen, Manfred


    International trade has an impact on national CO 2 emissions and consequently on the ability to fulfil national CO 2 reduction targets. Through goods and services traded in a globally interdependent world, the consumption in each country is linked to greenhouse gas emissions in other countries. It has been argued that in order to achieve equitable reduction targets, international trade has to be taken into account when assessing nations' responsibility for abating climate change. Especially for open economies such as Denmark, greenhouse gases embodied in internationally traded commodities can have a considerable influence on the national 'greenhouse gas responsibility'. By using input-output modelling, we analyse the influence from international trade on national CO 2 emissions. The aim is to show that trade is the key to define CO 2 responsibility on a macroeconomic level and that imports should be founded in a multi-region model approach. Finally, the paper concludes on the need to consider the impact from foreign trade when negotiating reduction targets and base line scenarios. (Author)

  18. Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux (United States)

    A. Christopher Oishi; Sari Palmroth; Kurt H. Johnsen; Heather R. McCarthy; Ram. Oren


    Soil CO2 efflux (Fsoil) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity,...

  19. Uncertainties in the CO2 buget associated to boundary layer dynamics and CO2-advection

    NARCIS (Netherlands)

    Kaikkonen, J.P.; Pino, D.; Vilà-Guerau de Arellano, J.


    The relationship between boundary layer dynamics and carbon dioxide (CO2) budget in the convective boundary layer (CBL) is investigated by using mixed-layer theory. We derive a new set of analytical relations to quantify the uncertainties on the estimation of the bulk CO2 mixing ratio and the

  20. Literatuuronderzoek CAM-fotosynthese en CO2-bemesting en CO2-bemesting bij bromelia's

    NARCIS (Netherlands)

    Marissen, A.; Warmenhoven, M.G.


    De ‘normale’ wijze van CO2-opname gebeurt bij de meeste planten overdag, wanneer er licht is om de opgenomen CO2 door middel van fotosynthese direct om te zetten in suikers. Hiervoor is het nodig dat de huidmondjes overdag open staan, ‘s nachts zijn huidmondjes meestal dicht. Via de huidmondjes gaat

  1. CO2 emissions vs. CO2 responsibility: An input-output approach for the Turkish economy

    International Nuclear Information System (INIS)

    Ipek Tunc, G.; Tueruet-Asik, Serap; Akbostanci, Elif


    Recently, global warming (greenhouse effect) and its effects have become one of the hottest topics in the world agenda. There have been several international attempts to reduce the negative effects of global warming. The Kyoto Protocol can be cited as the most important agreement which tries to limit the countries' emissions within a time horizon. For this reason, it becomes important to calculate the greenhouse gas emissions of countries. The aim of this study is to estimate the amount of CO 2 -the most important greenhouse gas-emissions, for the Turkish economy. An extended input-output model is estimated by using 1996 data in order to identify the sources of CO 2 emissions and to discuss the share of sectors in total emission. Besides, 'CO 2 responsibility', which takes into account the CO 2 content of imports, is estimated for the Turkish economy. The sectoral CO 2 emissions and CO 2 responsibilities are compared and these two notions are linked to foreign trade volume. One of the main conclusions is that the manufacturing industry has the first place in both of the rankings for CO 2 emissions and CO 2 responsibilities, while agriculture and husbandry has the last place

  2. Rising pCO2in Freshwater Ecosystems Has the Potential to Negatively Affect Predator-Induced Defenses in Daphnia. (United States)

    Weiss, Linda C; Pötter, Leonie; Steiger, Annika; Kruppert, Sebastian; Frost, Uwe; Tollrian, Ralph


    Anthropogenically released CO 2 accumulates in the global carbon cycle and is anticipated to imbalance global carbon fluxes [1]. For example, increased atmospheric CO 2 induces a net air-to-sea flux where the oceans take up large amounts of atmospheric CO 2 (i.e., ocean acidification [2-5]). Research on ocean acidification is ongoing, and studies have demonstrated the consequences for ecosystems and organismal biology with major impacts on marine food webs, nutrient cycles, overall productivity, and biodiversity [6-9]. Yet, surprisingly little is known about the impact of anthropogenically caused CO 2 on freshwater systems due to their more complex biogeochemistry. The current consensus, yet lacking data evidence, is that anthropogenic CO 2 does indeed affect freshwater carbon hydrogeochemistry, causing increased pCO 2 in freshwater bodies [10-13]. We analyzed long-term data from four freshwater reservoirs and observed a continuous pCO 2 increase associated with a decrease in pH, indicating that not only the oceans but also inland waters are accumulating CO 2 . We tested the effect of pCO 2 -dependent freshwater acidification using the cosmopolite crustacean Daphnia. For general validity, control pCO 2 -levels were based on the present global pCO 2 average. Treatments were selected with very high pCO 2 levels, assuming a continuous non-linear increase of pCO 2 , reflecting worst-case-scenario future pCO 2 levels. Such levels of elevated pCO 2 reduced the ability of Daphnia to sense its predators and form adequate inducible defenses. We furthermore determined that pCO 2 and not the resulting reduction in pH impairs predator perception. If pCO 2 alters chemical communication between freshwater species, this perturbs intra- and interspecific information transfer, which may affect all trophic levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. CO2 emissions and reduction potential in China's chemical industry

    International Nuclear Information System (INIS)

    Zhu, Bing; Zhou, Wenji; Hu, Shanying; Li, Qiang; Griffy-Brown, Charla; Jin, Yong


    GHG (Increasing greenhouse gas) emissions in China imposes enormous pressure on China's government and society. The increasing GHG trend is primarily driven by the fast expansion of high energy-intensive sectors including the chemical industry. This study investigates energy consumption and CO 2 emissions in the processes of chemical production in China through calculating the amounts of CO 2 emissions and estimating the reduction potential in the near future. The research is based on a two-level perspective which treats the entire industry as Level one and six key sub-sectors as Level two, including coal-based ammonia, calcium carbide, caustic soda, coal-based methanol, sodium carbonate, and yellow phosphorus. These two levels are used in order to address the complexity caused by the fact that there are more than 40 thousand chemical products in this industry and the performance levels of the technologies employed are extremely uneven. Three scenarios with different technological improvements are defined to estimate the emissions of the six sub-sectors and analyze the implied reduction potential in the near future. The results highlight the pivotal role that regulation and policy administration could play in controlling the CO 2 emissions by promoting average technology performances in this industry.

  4. Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Fauth, D.J.; Filburn, T.P. (University of Hartford, West Hartford, CT); Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.


    Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

  5. Extraction of lipids from microalgae using CO2-expanded methanol and liquid CO2. (United States)

    Paudel, Ashok; Jessop, Michael J; Stubbins, Spencer H; Champagne, Pascale; Jessop, Philip G


    The use of CO2-expanded methanol (cxMeOH) and liquid carbon dioxide (lCO2) is proposed to extract lipids from Botryococcus braunii. When compressed CO2 dissolves in methanol, the solvent expands in volume, decreases in polarity and so increases in its selectivity for biodiesel desirable lipids. Solid phase extraction of the algal extract showed that the cxMeOH extracted 21 mg of biodiesel desirable lipids per mL of organic solvent compared to 3mg/mL using either neat methanol or chloroform/methanol mixture. The non-polar lCO2 showed a high affinity for non-polar lipids. Using lCO2, it is possible to extract up to 10% neutral lipids relative to the mass of dry algae. Unlike extractions using conventional solvents, these new methods require little to no volatile, flammable, or chlorinated organic solvents. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Flash scanning the CO2 laser: a revival of the CO2 laser in plastic surgery (United States)

    Lach, Elliot


    The CO2 laser has broad clinical application yet also presents a number of practical disadvantages. These drawbacks have limited the success and utilization of this laser in plastic surgery. Flashscanner technology has recently been used for char-free CO2 laser surgery of the oropharynx, the external female genital tract, and perirectal mucosa. A commercially available optomechanical flashscanner unit `Swiftlase,' was adapted to a CO2 laser and used for treatment in numerous plastic surgical applications. Conditions and situations that were treated in this study included generalized neurofibromatosis, tuberous sclerosis, rhinophyma, viral warts, breast reconstruction, and deepithelialization prior to microsurgery or local flap transfer and/or skin graft placement. There were no significant wound healing complications. Some patients previously sustained undue scarring from conventional CO2 laser surgery. Conservative, primarily ablative CO2 laser surgery with the Swiftlase has usefulness for treatment of patients in plastic surgery including those that were previously unsuccessfully treated.

  7. The Li–CO2 battery: a novel method for CO2 capture and utilization

    KAUST Repository

    Xu, Shaomao


    We report a novel primary Li-CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g-1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than that at 40 °C, and the temperature dependence is significantly weaker for higher surface area carbon cathodes. Ex-situ FTIR and XRD analyses convincingly show that lithium carbonate (Li2CO3) is the main component of the discharge product. The feasibility of similar primary metal-CO2 batteries based on earth abundant metal anodes, such as Al and Mg, is demonstrated. The metal-CO2 battery platform provides a novel approach for simultaneous capturing of CO2 emissions and producing electrical energy. © 2013 The Royal Society of Chemistry.

  8. Imaging volcanic CO2 and SO2 (United States)

    Gabrieli, A.; Wright, R.; Lucey, P. G.; Porter, J. N.


    Detecting and quantifying volcanic carbon dioxide (CO2) and sulfur dioxide (SO2) emissions is of relevance to volcanologists. Changes in the amount and composition of gases that volcanoes emit are related to subsurface magma movements and the probability of eruptions. Volcanic gases and related acidic aerosols are also an important atmospheric pollution source that create environmental health hazards for people, animals, plants, and infrastructures. For these reasons, it is important to measure emissions from volcanic plumes during both day and night. We present image measurements of the volcanic plume at Kīlauea volcano, HI, and flux derivation, using a newly developed 8-14 um hyperspectral imaging spectrometer, the Thermal Hyperspectral Imager (THI). THI is capable of acquiring images of the scene it views from which spectra can be derived from each pixel. Each spectrum contains 50 wavelength samples between 8 and 14 um where CO2 and SO2 volcanic gases have diagnostic absorption/emission features respectively at 8.6 and 14 um. Plume radiance measurements were carried out both during the day and the night by using both the lava lake in the Halema'uma'u crater as a hot source and the sky as a cold background to detect respectively the spectral signatures of volcanic CO2 and SO2 gases. CO2 and SO2 path-concentrations were then obtained from the spectral radiance measurements using a new Partial Least Squares Regression (PLSR)-based inversion algorithm, which was developed as part of this project. Volcanic emission fluxes were determined by combining the path measurements with wind observations, derived directly from the images. Several hours long time-series of volcanic emission fluxes will be presented and the SO2 conversion rates into aerosols will be discussed. The new imaging and inversion technique, discussed here, are novel allowing for continuous CO2 and SO2 plume mapping during both day and night.

  9. CO2 Orbital Trends in Comets (United States)

    Kelley, Michael; Feaga, Lori; Bodewits, Dennis; McKay, Adam; Snodgrass, Colin; Wooden, Diane


    Spacecraft missions to comets return a treasure trove of details of their targets, e.g., the Rosetta mission to comet 67P/Churyumov-Gerasimenko, the Deep Impact experiment at comet 9P/Tempel 1, or even the flyby of C/2013 A1 (Siding Spring) at Mars. Yet, missions are rare, the diversity of comets is large, few comets are easily accessible, and comet flybys essentially return snapshots of their target nuclei. Thus, telescopic observations are necessary to place the mission data within the context of each comet's long-term behavior, and to further connect mission results to the comet population as a whole. We propose a large Cycle 11 project to study the long-term activity of past and potential future mission targets, and select bright Oort cloud comets to infer comet nucleus properties, which would otherwise require flyby missions. In the classical comet model, cometary mass loss is driven by the sublimation of water ice. However, recent discoveries suggest that the more volatile CO and CO2 ices are the likely drivers of some comet active regions. Surprisingly, CO2 drove most of the activity of comet Hartley 2 at only 1 AU from the Sun where vigorous water ice sublimation would be expected to dominate. Currently, little is known about the role of CO2 in comet activity because telluric absorptions prohibit monitoring from the ground. In our Cycle 11 project, we will study the CO2 activity of our targets through IRAC photometry. In conjunction with prior observations of CO2 and CO, as well as future data sets (JWST) and ongoing Earth-based projects led by members of our team, we will investigate both long-term activity trends in our target comets, with a particular goal to ascertain the connections between each comet's coma and nucleus.



    Raganati, Federica


    Adsorption using solid sorbents is recognized to be attractive to complement or replace the current absorption technology for CO2 capture due to its low energy requirement. However, the development of new highly specific CO2 adsorbent is necessary: a solution is represented by fine materials, whose properties can be tuned at a molecular level by means of functionalization processes to tailor their CO2 capture performance. Another point to be addressed is the adoption of an adequate reactor co...

  11. The Role of the CO2 Laser and Fractional CO2 Laser in Dermatology. (United States)

    Omi, Tokuya; Numano, Kayoko


    Tremendous advances have been made in the medical application of the laser in the past few decades. Many diseases in the dermatological field are now indications for laser treatment that qualify for reimbursement by many national health insurance systems. Among laser types, the carbon dioxide (CO2) laser remains an important system for the dermatologist. The lasers used in photosurgery have wavelengths that differ according to their intended use and are of various types, but the CO2 laser is one of the most widely used lasers in the dermatology field. With its wavelength in the mid-infrared at 10,600 nm, CO2 laser energy is wellabsorbed in water. As skin contains a very high water percentage, this makes the CO2 laser ideal for precise, safe ablation with good hemostasis. In addition to its efficacy in ablating benign raised lesions, the CO2 laser has been reported to be effective in the field of esthetic dermatology in the revision of acne scars as well as in photorejuvenation. With the addition of fractionation of the beam of energy into myriad microbeams, the fractional CO2 laser has offered a bridge between the frankly full ablative indications and the nonablative skin rejuvenation systems of the 2000s in the rejuvenation of photoaged skin on and off the face. The CO2 laser remains an efficient, precise and safe system for the dermatologist. Technological advances in CO2 laser construction have meant smaller spot sizes and greater precision for laser surgery, and more flexibility in tip sizes and protocols for fractional CO2 laser treatment. The range of dermatological applications of the CO2 laser is expected to continue to increase in the future.

  12. Volcanic Versus Anthropogenic CO2: An Example of the Importance of Geoscience Evidence (United States)

    Gerlach, T.


    degassing of more than 35 gigatons of CO2 from global magma production-volcanic plus plutonic-would imply global magma averaging more than 30-weight-percent CO2. This conflicts with evidence that primary CO2 concentrations of common magmas are not greater than about 1.5 weight percent. Further, to create more than 35 Gt/y of volcanic CO2 would require global magma production (at 1.5 weight percent CO2) in excess of 850 cubic km/y. It is implausible that this much magma production-over 40 times the annual mid-ocean ridge magma supply-is going unnoticed, on land or beneath the sea. Releases of more than 35 Gt/y of volcanic CO2 into the oceans would also be inconsistent with seawater's acid-buffering capacity and its role as a major sink for atmospheric CO2. Scaling up volcanism to the hypothetical intensity required to generate CO2 emissions at anthropogenic levels suggests that humanity's CO2 emissions may already exceed the annual CO2 emissions of several continental flood basalt eruptions or the CO2 output of 1-10 supereruptions every year. Present-day global volcanic CO2 emissions are clearly not an excuse for disregarding concerns about humanity's CO2 emissions.

  13. Evaluating the molecular, physiological and behavioral impacts of CO2narcosis in bumble bees (Bombus impatiens). (United States)

    Amsalem, Etya; Grozinger, Christina M


    Exposure to carbon dioxide (CO 2 ) has pleiotropic effects in many insect species, ranging from eliciting rapid behavioral responses such as attraction, to dramatic physiological changes, including ovary activation. In bumble bees, CO 2 narcosis causes queens to bypass diapause and initiate egg laying, but its mode of action is not well-understood. Here, we evaluated the effects of CO 2 narcosis on the behavior, physiology and immune function of virgin bumble bee queens (Bombus impatiens). We tested the hypothesis that CO 2 induces these changes by stimulating oxidative stress response pathways. We found that CO 2 stimulates ovarian activation and egg production and suppresses lipid (but not glycogen) accumulation in virgin queens. Additionally, CO 2 treated queens were more active (particularly in terms of flight) and performed, but did not receive, more aggressive behaviors compared to controls. Moreover, CO 2 positively affected immune function in queens, reduced transcript levels of 5/6 antioxidant enzyme genes and had no effect on longevity. Thus, although CO 2 treatment stimulated reproduction, we did not observe any evidence of a trade-off in queen health parameters, aside from a reduction in lipids. Overall CO 2 narcosis does not appear to stimulate a typical stress response in virgin bumble bee queens. On the contrary, CO 2 narcosis appears to stimulate changes that prepare queens to cope with the nutritional, metabolic and behavioral challenges associated with reproduction and colony-founding. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Elevated CO2 affects predator-prey interactions through altered performance.

    Directory of Open Access Journals (Sweden)

    Bridie J M Allan

    Full Text Available Recent research has shown that exposure to elevated carbon dioxide (CO2 affects how fishes perceive their environment, affecting behavioral and cognitive processes leading to increased prey mortality. However, it is unclear if increased mortality results from changes in the dynamics of predator-prey interactions or due to prey increasing activity levels. Here we demonstrate that ocean pCO2 projected to occur by 2100 significantly effects the interactions of a predator-prey pair of common reef fish: the planktivorous damselfish Pomacentrus amboinensis and the piscivorous dottyback Pseudochromis fuscus. Prey exposed to elevated CO2 (880 µatm or a present-day control (440 µatm interacted with similarly exposed predators in a cross-factored design. Predators had the lowest capture success when exposed to elevated CO2 and interacting with prey exposed to present-day CO2. Prey exposed to elevated CO2 had reduced escape distances and longer reaction distances compared to prey exposed to present-day CO2 conditions, but this was dependent on whether the prey was paired with a CO2 exposed predator or not. This suggests that the dynamics of predator-prey interactions under future CO2 environments will depend on the extent to which the interacting species are affected and can adapt to the adverse effects of elevated CO2.

  15. Nematode Genera in Forest Soil Respond Differentially to Elevated CO2 (United States)

    Neher, Deborah A.; Weicht, Thomas R.


    Previous reports suggest that fungivorous nematodes are the only trophic group in forest soils affected by elevated CO2. However, there can be ambiguity within trophic groups, and we examined data at a genus level to determine whether the conclusion remains similar. Nematodes were extracted from roots and soil of loblolly pine (Pinus taeda) and sweet gum (Liquidambar styraciflua) forests fumigated with either ambient air or CO2-enriched air. Root length and nematode biomass were estimated using video image analysis. Most common genera included Acrobeloides, Aphelenchoides, Cephalobus, Ditylenchus, Ecphyadorphora, Filenchus, Plectus, Prismatolaimus, and Tylencholaimus. Maturity Index values and diversity increased with elevated CO2 in loblolly pine but decreased with elevated CO2 in sweet gum forests. Elevated CO2 treatment affected the occurrence of more nematode genera in sweet gum than loblolly pine forests. Numbers were similar but size of Xiphinema decreased in elevated CO2. Abundance, but not biomass, of Aphelenchoides was reduced by elevated CO2. Treatment effects were apparent at the genus levels that were masked at the trophic level. For example, bacterivores were unaffected by elevated CO2, but abundance of Cephalobus was affected by CO2 treatment in both forests. PMID:24115786

  16. CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

    Directory of Open Access Journals (Sweden)

    C. Lac


    Full Text Available Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is a challenging and interesting task needed to be performed in order to utilise CO2 measurements in an atmospheric inverse framework and to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town Energy Balance (TEB urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs surface scheme, allowing a full interaction of CO2 modelling between the surface and the atmosphere. Statistical scores show a good representation of the urban heat island (UHI with stronger urban–rural contrasts on temperature at night than during the day by up to 7 °C. Boundary layer heights (BLH have been evaluated on urban, suburban and rural sites during the campaign, and also on a suburban site over 1 yr. The diurnal cycles of the BLH are well captured, especially the onset time of the BLH increase and its growth rate in the morning, which are essential for tall tower CO2 observatories. The main discrepancy is a small negative bias over urban and suburban sites during nighttime (respectively 45 m and 5 m, leading to a few overestimations of nocturnal CO2 mixing ratios at suburban sites and a bias of +5 ppm. The diurnal CO2 cycle is generally well captured for all the sites. At the Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the atmospheric boundary layer (ABL growth reaches the measurement height. At suburban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a strong spatio-temporal variability. A

  17. Space Suit CO2 Washout During Intravehicular Activity (United States)

    Augustine, Phillip M.; Navarro, Moses; Conger, Bruce; Sargusingh, Miriam M.


    Space suit carbon dioxide (CO2) washout refers to the removal of CO2 gas from the oral-nasal area of a suited astronaut's (or crewmember's) helmet using the suit's ventilation system. Inadequate washout of gases can result in diminished mental/cognitive abilities as well as headaches and light headedness. In addition to general discomfort, these ailments can impair an astronaut s ability to perform mission-critical tasks ranging from flying the space vehicle to performing lunar extravehicular activities (EVAs). During design development for NASA s Constellation Program (CxP), conflicting requirements arose between the volume of air flow that the new Orion manned space vehicle is allocated to provide to the suited crewmember and the amount of air required to achieve CO2 washout in a space suit. Historically, space suits receive 6.0 actual cubic feet per minute (acfm) of air flow, which has adequately washed out CO2 for EVAs. For CxP, the Orion vehicle will provide 4.5 acfm of air flow to the suit. A group of subject matter experts (SM Es) among the EVA Systems community came to an early consensus that 4.5 acfm may be acceptable for low metabolic rate activities. However, this value appears very risky for high metabolic rates, hence the need for further analysis and testing. An analysis was performed to validate the 4.5 acfm value and to determine if adequate CO2 washout can be achieved with the new suit helmet design concepts. The analysis included computational fluid dynamic (CFD) modeling cases, which modeled the air flow and breathing characteristics of a human wearing suit helmets. Helmet testing was performed at the National Institute of Occupational Safety and Health (NIOSH) in Pittsburgh, Pennsylvania, to provide a gross-level validation of the CFD models. Although there was not a direct data correlation between the helmet testing and the CFD modeling, the testing data showed trends that are very similar to the CFD modeling. Overall, the analysis yielded

  18. Biomass burial and storage to reduce atmospheric CO2 (United States)

    Zeng, N.


    To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a theoretical carbon sequestration potential for wood burial is 10 ± 5 GtC/y, but probably 1-3 GtC/y can be realized in practice. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other environmental concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from forest industry, the cost for wood burial is estimated to be 14/tCO2 (50/tC), lower than the typical cost for power plant CO2 capture with geological storage. The low cost for carbon sequestration with wood burial is possible because the technique uses the natural process of photosynthesis to remove carbon from the atmosphere. The technique is low tech, distributed, safe, and can be stopped at any time, thus an attractive option for large-scale implementation in a world-wide carbon market.

  19. Simulation Studies of Satellite Laser CO2 Mission Concepts (United States)

    Kawa, S. R.; Mao, J.; Abshire, J. B.; Collatz, G. J.; Sun, X.; Weaver, C. J.; Browell, E. V.


    Results of mission simulation studies are presented for a laser-based atmospheric CO2 sounder. The simulations are based on real-time carbon cycle process modeling and data analysis. The mission concept corresponds to ASCENDS as recommended by the US National Academy of Sciences Decadal Survey. Compared to passive sensors, active (lidar) sensing of CO2 from space has several potentially significant advantages that hold promise to advance CO2 measurement capability in the next decade. Although the precision and accuracy requirements remain at unprecedented levels of stringency, analysis of possible instrument technology indicates that such sensors are more than feasible. As a prerequisite for quantitative sensor evaluation we have assembled a relatively complete description of the atmospheric and surface state that is needed to estimate the random error component of prospective CO2 measurements. The state is obtained from meteorological data assimilation and satellite measurements from MODIS and CALIPSO. The resulting error distributions will be used in inverse studies to estimate the fidelity of surface flux estimation from the laser observations. Radiative transfer model calculations, an instrument model with representative errors, and a simple retrieval approach complete the cycle from "nature" run to "pseudo-data" CO2 with error bounds. The results indicate that within reasonable technological assumptions for the system performance, high measurement precision can be obtained that will fulfill the nominal ASCENDS objectives. Several mission and instrument configuration options are examined, and the sensitivity to key design variables is shown. Examples are also shown of how the resulting pseudo-measurements might be used to address key carbon cycle science questions.

  20. Assesment of Energy Options for CO2 Emission Reduction

    International Nuclear Information System (INIS)

    Cavlina, Nikola


    Since the 1992 Earth Summit in Rio de Janeiro, global anthropogenic CO 2 emissions grew by 52% which caused an increase in 10.8% in the CO 2 concentration in the atmosphere, and it tipped the 400 ppm mark in May 2013. The Fifth Assessment Report on climate impacts from the Intergovernmental Panel on Climate Change (IPCC) confirmed earlier warnings that climate change is already stressing human communities, agriculture, and natural ecosystems, and the effects are likely to increase in the future. While European Union has long been committed to lowering carbon emissions, this places additional pressure on current EU goals for energy sector that includes significant reduction of CO 2 emissions. Current EU commitment has been formalized in so-called '20-20-20' plan, reducing carbon emissions, increasing energy efficiency and increasing energy production from renewables by 20% by 2020. Some EU member states are even more ambitious, like United Kingdom, planning to reduce carbon emissions by 80% by 2050. Bulk of carbon reduction will have to be achived in energy sector. In the power industry, most popular solution is use of solar and wind power. Since their production varies significantly during the day, for the purpose of base-load production they can be paired with gas-fired power plant. Other possible CO 2 -free solution is nuclear power plant. In this invited lecture, predicted cost of energy production for newly bulit nuclear power plant and newly built combination of wind or solar and gas-fired power plant are compared. Comparison was done using Levelized Unit of Energy Cost (LUEC). Calculations were performed using the Monte Carlo method. For input parameters that have biggest uncertainty (gas cost, CO 2 emission fee) those uncertainties were addressed not only through probability distribution around predicted value, but also through different scenarious. (author)

  1. Research of CO2 concentration in naturally ventilated lecture room (United States)

    Laska, Marta; Dudkiewicz, Edyta


    Naturally ventilated buildings especially dedicated for educational purposes need to be design to achieve required level of thermal comfort and indoor air quality. It is crucial in terms of both: health and productivity of the room users. Higher requirements of indoor environment are important due to the level of students concentration, their ability to acquire new knowledge and willingness to interact with the lecturer. The article presents the results of experimental study and surveys undertaken in naturally ventilated lecture room. The data is analysed in terms of CO2 concentration and its possible influence on users. Furthermore the outcome of the research is compared with the CO2 concentration models available in the literature.

  2. High-powered CO2 -lasers and noise control (United States)

    Honkasalo, Antero; Kuronen, Juhani

    High-power CO2 -lasers are being more and more widely used for welding, drilling and cutting in machine shops. In the near future, different kinds of surface treatments will also become routine practice with laser units. The industries benefitting most from high power lasers will be: the automotive industry, shipbuilding, the offshore industry, the aerospace industry, the nuclear and the chemical processing industries. Metal processing lasers are interesting from the point of view of noise control because the working tool is a laser beam. It is reasonable to suppose that the use of such laser beams will lead to lower noise levels than those connected with traditional metal processing methods and equipment. In the following presentation, the noise levels and possible noise-control problems attached to the use of high-powered CO2 -lasers are studied.

  3. Estimates of CO2 from fires in the United States: implications for carbon management

    Directory of Open Access Journals (Sweden)

    Neff Jason C


    Full Text Available Abstract Background Fires emit significant amounts of CO2 to the atmosphere. These emissions, however, are highly variable in both space and time. Additionally, CO2 emissions estimates from fires are very uncertain. The combination of high spatial and temporal variability and substantial uncertainty associated with fire CO2 emissions can be problematic to efforts to develop remote sensing, monitoring, and inverse modeling techniques to quantify carbon fluxes at the continental scale. Policy and carbon management decisions based on atmospheric sampling/modeling techniques must account for the impact of fire CO2 emissions; a task that may prove very difficult for the foreseeable future. This paper addresses the variability of CO2 emissions from fires across the US, how these emissions compare to anthropogenic emissions of CO2 and Net Primary Productivity, and the potential implications for monitoring programs and policy development. Results Average annual CO2 emissions from fires in the lower 48 (LOWER48 states from 2002–2006 are estimated to be 213 (± 50 std. dev. Tg CO2 yr-1 and 80 (± 89 std. dev. Tg CO2 yr-1 in Alaska. These estimates have significant interannual and spatial variability. Needleleaf forests in the Southeastern US and the Western US are the dominant source regions for US fire CO2 emissions. Very high emission years typically coincide with droughts, and climatic variability is a major driver of the high interannual and spatial variation in fire emissions. The amount of CO2 emitted from fires in the US is equivalent to 4–6% of anthropogenic emissions at the continental scale and, at the state-level, fire emissions of CO2 can, in some cases, exceed annual emissions of CO2 from fossil fuel usage. Conclusion The CO2 released from fires, overall, is a small fraction of the estimated average annual Net Primary Productivity and, unlike fossil fuel CO2 emissions, the pulsed emissions of CO2 during fires are partially counterbalanced

  4. Effects of elevated CO2 on litter chemistry and subsequent invertebrate detritivore feeding responses.

    Directory of Open Access Journals (Sweden)

    Matthew W Dray

    Full Text Available Elevated atmospheric CO2 can change foliar tissue chemistry. This alters leaf litter palatability to macroinvertebrate detritivores with consequences for decomposition, nutrient turnover, and food-web structure. Currently there is no consensus on the link between CO2 enrichment, litter chemistry, and macroinvertebrate-mediated leaf decomposition. To identify any unifying mechanisms, we presented eight invertebrate species from aquatic and terrestrial ecosystems with litter from Alnus glutinosa (common alder or Betula pendula (silver birch trees propagated under ambient (380 ppm or elevated (ambient +200 ppm CO2 concentrations. Alder litter was largely unaffected by CO2 enrichment, but birch litter from leaves grown under elevated CO2 had reduced nitrogen concentrations and greater C/N ratios. Invertebrates were provided individually with either (i two litter discs, one of each CO2 treatment ('choice', or (ii one litter disc of each CO2 treatment alone ('no-choice'. Consumption was recorded. Only Odontocerum albicorne showed a feeding preference in the choice test, consuming more ambient- than elevated-CO2 birch litter. Species' responses to alder were highly idiosyncratic in the no-choice test: Gammarus pulex and O. albicorne consumed more elevated-CO2 than ambient-CO2 litter, indicating compensatory feeding, while Oniscus asellus consumed more of the ambient-CO2 litter. No species responded to CO2 treatment when fed birch litter. Overall, these results show how elevated atmospheric CO2 can alter litter chemistry, affecting invertebrate feeding behaviour in species-specific ways. The data highlight the need for greater species-level information when predicting changes to detrital processing-a key ecosystem function-under atmospheric change.

  5. Photosynthetic carbon metabolism in photoautotrophic cell suspension cultures grown at low and high CO2

    International Nuclear Information System (INIS)

    Roeske, C.A.; Widholm, J.M.; Ogren, W.L.


    Photosynthetic carbon metabolism was characterized in four photoautotrophic cell suspension cultures. There was no apparent difference between two soybeans (Glycine max) and one cotton (Gossypium hirsutum) cell line which required 5% CO 2 for growth, and a unique cotton cell line that grows at ambient CO 2 (660 microliters per liter). Photosynthetic characteristics in all four lines were more like C 3 mesophyll leaf cells than the cell suspension cultures previously studied. The pattern of 14 C-labeling reflected the high ratio of ribulosebisphosphate carboxylase to phosphoenolpyruvate carboxylase activity and showed that CO 2 fixation occurred primarily by the C 3 pathway. Photorespiration occurred at 330 microliters per liter CO 2 , 21% O 2 as indicated by the synthesis of high levels of 14 C-labeled glycine and serine in a pulse-chase experiment and by oxygen inhibition of CO 2 fixation. Short-term CO 2 fixation in the presence and absence of carbonic anhydrase showed CO 2 , not HCO 3 - , to be the main source of inorganic carbon taken up by the low CO 2 -requiring cotton cells. The cells did not have a CO 2 -concentrating mechanism as indicated by silicone oil centrifugation experiments. Carbonic anhydrase was absent in the low CO 2 -requiring cotton cells, present in the high CO 2 -requiring soybean cell lines, and absent in other high CO 2 cell lines examined. Thus, the presence of carbonic anhydrase is not an essential requirement for photoautotrophy in cell suspension cultures which grow at either high or low CO 2 concentrations

  6. Fossil fuel CO2 estimation by atmospheric 14C measurement and CO2 mixing ratios in the city of Debrecen, Hungary

    International Nuclear Information System (INIS)

    Molnar, M.; Svingor, E.; Haszpra, L.; Ivo Svetlik; Veres, M.


    A field unit was installed in the city of Debrecen (East Hungary) during the summer of 2008 to monitor urban atmospheric fossil fuel CO 2 . To establish a reference level simultaneous CO 2 sampling has been carried out at a rural site (Hegyhatsal) in Western Hungary. Using the Hungarian background 14 CO 2 observations from the rural site atmospheric fossil fuel CO 2 component for the city of Debrecen was reported in a regional 'Hungarian' scale. A well visible fossil fuel CO 2 peak (10-15 ppm) with a maximum in the middle of winter 2008 (January) was observed in Debrecen air. Significant local maximum (∼20 ppm) in fossil fuel CO 2 during Octobers of 2008 and 2009 was also detected. Stable isotope results are in agreement with the 14 C based fossil fuel CO 2 observations as the winter of 2008 and 2009 was different in atmospheric δ 13 C variations too. The more negative δ 13 C of atmospheric CO 2 in the winter of 2008 means more fossil carbon in the atmosphere than during the winter of 2009. (author)

  7. Essays on the Determinants of Energy Related CO2 Emissions = (United States)

    Moutinho, Victor Manuel Ferreira

    emissions intensity is negative. The percentage of fossil fuels used reacts positively to the economic structure and to carbon intensity, i. e., the more the economic importance of the sector, the more it uses fossil fuels, and when it raises its carbon intensity, in the future the use of fossil fuel may rise. On the other hand, positive shocks on energy intensity tend to reduce the percentage of fossil fuels used. In fourth essay, we conducted an analysis to identify the effects that contribute to the intensity of GHG emissions (EI) in agriculture as well as their development. With that aim, we used the 'complete decomposition' technique in the 1995-2008 periods, for a set of European countries. It is shown that the use of Nitrogen per cultivated area is an important factor of emissions and in those countries where labour productivity increases (the inverse of average labour productivity in agriculture decreases), emissions intensity tends to decrease. These results imply that the way to reduce emissions in agriculture would be to provide better training of agricultural workers to increase their productivity, which would lead to a less need for energy and use of Nitrogen. The purpose of the last essay is to examine the long and short-run causality of the share of renewable sources on the environmental relation CO2 per KWh electricity generation- real GDP for 20 European countries over the 2001-2010 periods. It is important to analyze how the percentage of renewable energy used for electricity production affects the relationship between economic growth and emissions from this sector. The study of these relationships is important from the point of view of environmental and energy policy as it gives us information on the costs in terms of economic growth, on the application of restrictive levels of emissions and also on the effects of the policies concerning the use of renewable energy in the electricity sector (see for instance European Commission Directive 2001/77/EC, [4

  8. CO2 Laser Cutting of Hot Stamping Boron Steel Sheets


    Pasquale Russo Spena


    This study investigates the quality of CO2 laser cutting of hot stamping boron steel sheets that are employed in the fabrication of automotive body-in-white. For this purpose, experimental laser cutting tests were conducted on 1.2 mm sheets at varying levels of laser power, cutting speed, and oxygen pressure. The resulting quality of cut edges was evaluated in terms of perpendicularity tolerance, surface irregularity, kerf width, heat affected zone, and dross extension. Experimental tests wer...

  9. Strengthening seasonal marine CO2 variations due to increasing atmospheric CO2 (United States)

    Landschützer, Peter; Gruber, Nicolas; Bakker, Dorothee C. E.; Stemmler, Irene; Six, Katharina D.


    The increase of atmospheric CO2 (ref. 1) has been predicted to impact the seasonal cycle of inorganic carbon in the global ocean2,3, yet the observational evidence to verify this prediction has been missing. Here, using an observation-based product of the oceanic partial pressure of CO2 (pCO2) covering the past 34 years, we find that the winter-to-summer difference of the pCO2 has increased on average by 2.2 ± 0.4 μatm per decade from 1982 to 2015 poleward of 10° latitude. This is largely in agreement with the trend expected from thermodynamic considerations. Most of the increase stems from the seasonality of the drivers acting on an increasing oceanic pCO2 caused by the uptake of anthropogenic CO2 from the atmosphere. In the high latitudes, the concurrent ocean-acidification-induced changes in the buffer capacity of the ocean enhance this effect. This strengthening of the seasonal winter-to-summer difference pushes the global ocean towards critical thresholds earlier, inducing stress to ocean ecosystems and fisheries4. Our study provides observational evidence for this strengthening seasonal difference in the oceanic carbon cycle on a global scale, illustrating the inevitable consequences of anthropogenic CO2 emissions.

  10. CO2 Capture by Injection of Flue Gas or CO2-N2 Mixtures into Hydrate Reservoirs: Dependence of CO2 Capture Efficiency on Gas Hydrate Reservoir Conditions. (United States)

    Hassanpouryouzband, Aliakbar; Yang, Jinhai; Tohidi, Bahman; Chuvilin, Evgeny; Istomin, Vladimir; Bukhanov, Boris; Cheremisin, Alexey


    Injection of flue gas or CO 2 -N 2 mixtures into gas hydrate reservoirs has been considered as a promising option for geological storage of CO 2 . However, the thermodynamic process in which the CO 2 present in flue gas or a CO 2 -N 2 mixture is captured as hydrate has not been well understood. In this work, a series of experiments were conducted to investigate the dependence of CO 2 capture efficiency on reservoir conditions. The CO 2 capture efficiency was investigated at different injection pressures from 2.6 to 23.8 MPa and hydrate reservoir temperatures from 273.2 to 283.2 K in the presence of two different saturations of methane hydrate. The results showed that more than 60% of the CO 2 in the flue gas was captured and stored as CO 2 hydrate or CO 2 -mixed hydrates, while methane-rich gas was produced. The efficiency of CO 2 capture depends on the reservoir conditions including temperature, pressure, and hydrate saturation. For a certain reservoir temperature, there is an optimum reservoir pressure at which the maximum amount of CO 2 can be captured from the injected flue gas or CO 2 -N 2 mixtures. This finding suggests that it is essential to control the injection pressure to enhance CO 2 capture efficiency by flue gas or CO 2 -N 2 mixtures injection.

  11. Use of visual CO2 feedback as a retrofit solution for improving classroom air quality

    DEFF Research Database (Denmark)

    Wargocki, Pawel; Da Silva, Nuno Alexandre Faria


    Carbon dioxide (CO2) sensors that provide a visual indication were installed in classrooms during normal school operation. During 2-week periods, teachers and students were instructed to open the windows in response to the visual CO2 feedback in 1week and open them, as they would normally do...... and the other pair with no cooling. Classrooms were matched by grade. Providing visual CO2 feedback reduced CO2 levels, as more windows were opened in this condition. This increased energy use for heating and reduced the cooling requirement in summertime. Split cooling reduced the frequency of window opening...

  12. Sustainable Concrete Performance—CO2-Emission

    Directory of Open Access Journals (Sweden)

    Rafal Latawiec


    Full Text Available The balance of carbon dioxide emissions and other greenhouse gases in the life cycle of concrete is one of the important elements affecting the sustainable development of concrete technology. Modifications in the composition in the aim of minimization of so-called “carbon footprint” of concrete also affect the majority of its technical features, including primarily the mechanical properties and durability. The article presents a desirability function that would allow us to estimate the combined effect of the modification in terms of both CO2 emissions and some of the technical features of the concrete. As criterial features equivalent CO2 emission, compressive strength and susceptibility/resistance to concrete carbonation are selected. Selected features should be considered as an example for the presentation of the proposed methodology and represent the three pillars of concrete desirability in terms of sustainable development, i.e., the constructional usefulness, durability, and environmental performance.

  13. National CO2 emissions trading in European perspective; Nationale CO2-emissiehandel in Europees perspectief

    Energy Technology Data Exchange (ETDEWEB)



    This report is the reaction of the Social and economic council (SER) in the Netherlands to the request of the Dutch Ministry of Housing, Spatial Planning en Environment (VROM) to formulate an advice on the final report of the Committee CO2 Trade (a.k.a the Vogtlander Committee). This Committee has drafted a proposal for a CO2 emission trade system in the Netherlands. The SER has also taken into account the proposal of the European Committee on a guideline for CO2 emission trade in the European Union (EU)

  14. CO2 Absorption from Biogas by Glycerol: Conducted in Semi-Batch Bubble Column (United States)

    puji lestari, Pratiwi; Mindaryani, Aswati; Wirawan, S. K.


    Biogas is a renewable energy source that has been developed recently. The main contents of Biogas itself are Methane and carbon dioxide (CO2) where Methane is the main component of biogas with CO2 as the highest impurities. The quality of biogas depends on the CO2 content, the lower CO2 levels, the higher biogas quality. Absorption is one of the methods to reduce CO2 level. The selections of absorbent and appropriate operating parameters are important factors in the CO2 absorption from biogas. This study aimed to find out the design parameters for CO2 absorption using glycerol that represented by the overall mass transfer coefficient (KLa) and Henry’s constant (H). This study was conducted in semi-batch bubble column. Mixed gas was contacted with glycerol in a bubble column. The concentration of CO2 in the feed gas inlet and outlet columns were analysed by Gas Chromatograph. The variables observed in this study were superficial gas velocity and temperatures. The results showed that higher superficial gas velocity and lower temperature increased the rate of absorption process and the amount of CO2 absorbed.

  15. Determinants of CO2 growth in Italy

    International Nuclear Information System (INIS)

    Cozzi, L.; Di Giulio, E.


    In order to obtain a clear understanding of the relationship between the Italian economy and CO 2 emissions in the 1975-1995 period, a sectorial decomposition analysis of emissions, based on Laspeyres index analysis, were calculated. Building on this analysis, qualitative reflections are made in order to individuate the more appropriate areas of action to respect the target that the Kyoto Protocol assigns to Italy [it

  16. Integration of CO2 assessment tools


    van Noort, Martijn; Mahmod, Mohamed Kamil Morsi; Behrisch, Michael; Benz, Thomas


    The assessment of the CO2 impacts of ICT measures in transport requires a chain of software tools that need to be used in an integrated way. This paper reports on work performed in the Amitran project on a standard and an implementation for the assessment framework and interfaces that will enable researchers to easily combine these tools according to their preferences, and provides details on the implemented interfaces.

  17. Panorama 2016 - Chemical recycling of CO2

    International Nuclear Information System (INIS)

    Forti, Laurent; Fosse, Florian


    The ongoing rise of atmospheric carbon dioxide concentration is a major environmental and societal concern. Among the potential solutions for reducing carbon emissions in the energy sector, the chemical recycling of CO 2 has received considerable attention. Conversion of carbon dioxide into other recoverable substances offers the benefit of reducing the carbon footprint of newly developed products and of shifting away from the use of fossil resources. Various methods to create a wide range of products are currently being studied. (authors)

  18. Continuous CO2 extractor and methods

    International Nuclear Information System (INIS)


    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  19. Continuous CO2 extractor and methods

    Energy Technology Data Exchange (ETDEWEB)

    None listed


    The purpose of this CRADA was to assist in technology transfer from Russia to the US and assist in development of the technology improvements and applications for use in the U.S. and worldwide. Over the period of this work, ORNL has facilitated design, development and demonstration of a low-pressure liquid extractor and development of initial design for high-pressure supercritical CO2 fluid extractor.

  20. Bifunctional Catalysts for CO2 Reduction (United States)


    dioxide reduction catalysis . (SA 1 – Catalyst candidate synthesis) As outlined in the original proposal, ligand platforms have been synthesized to...was limited to outer-sphere electron transfer (necessary oxidation potentials for catalysis > –2.1 V vs. [Cp2Fe] +/0). Thus, we pursued two...high altitude air travel is the transportation of the fuel itself. Our targeted strategy is to transform CO2 into viable building blocks for synthetic

  1. CO2 capture takes its industrial turn

    International Nuclear Information System (INIS)

    Remoue, A.; Lutzky, A.


    The CO 2 capture and sequestration is entering the industrial era. The technologies are ready, the regulation is progressively put into action, the financing of demonstration facilities is unfreezing and companies are on the starting line from Canada to China, including the USA and Europe. The market takeoff is expected for 2015 but the competition is already hard between equipment manufacturers who wish to develop proprietary technologies. (J.S.)

  2. CO2 enhancement of forest productivity constrained by limited nitrogen availability (United States)

    Norby, Richard J.; Warren, Jeffrey M.; Iversen, Colleen M.; Medlyn, Belinda E.; McMurtrie, Ross E.


    Stimulation of terrestrial plant production by rising CO2 concentration is projected to reduce the airborne fraction of anthropogenic CO2 emissions. Coupled climate–carbon cycle models are sensitive to this negative feedback on atmospheric CO2, but model projections are uncertain because of the expectation that feedbacks through the nitrogen (N) cycle will reduce this so-called CO2 fertilization effect. We assessed whether N limitation caused a reduced stimulation of net primary productivity (NPP) by elevated atmospheric CO2 concentration over 11 y in a free-air CO2 enrichment (FACE) experiment in a deciduous Liquidambar styraciflua (sweetgum) forest stand in Tennessee. During the first 6 y of the experiment, NPP was significantly enhanced in forest plots exposed to 550 ppm CO2 compared with NPP in plots in current ambient CO2, and this was a consistent and sustained response. However, the enhancement of NPP under elevated CO2 declined from 24% in 2001–2003 to 9% in 2008. Global analyses that assume a sustained CO2 fertilization effect are no longer supported by this FACE experiment. N budget analysis supports the premise that N availability was limiting to tree growth and declining over time —an expected consequence of stand development, which was exacerbated by elevated CO2. Leaf- and stand-level observations provide mechanistic evidence that declining N availability constrained the tree response to elevated CO2; these observations are consistent with stand-level model projections. This FACE experiment provides strong rationale and process understanding for incorporating N limitation and N feedback effects in ecosystem and global models used in climate change assessments. PMID:20974944

  3. Sensitivity to hypercapnia and elimination of CO2 following diving in Steller sea lions (Eumetopias jubatus). (United States)

    Gerlinsky, Carling D; Rosen, David A S; Trites, Andrew W


    The diving ability of marine mammals is a function of how they use and store oxygen and the physiological control of ventilation, which is in turn dependent on the accumulation of CO2. To assess the influence of CO2 on physiological control of dive behaviour, we tested how increasing levels of inspired CO2 (hypercarbia) and decreasing inspired O2 (hypoxia) affected the diving metabolic rate, submergence times, and dive recovery times (time to replenish O2 stores and eliminate CO2) of freely diving Steller sea lions. We also measured changes in breathing frequency of diving and non-diving individuals. Our findings show that hypercarbia increased breathing frequency (as low as 2 % CO2), but did not affect metabolic rate, or the duration of dives or surface intervals (up to 3 % CO2). Changes in breathing rates indicated respiratory drive was altered by hypercarbia at rest, but blood CO2 levels remained below the threshold that would alter normal dive behaviour. It took the sea lions longer to remove accumulated CO2 than it did for them to replenish their O2 stores following dives (whether breathing ambient air, hypercarbia, or hypoxia). This difference between O2 and CO2 recovery times grew with increasing dive durations, increasing hypercarbia, and was greater for bout dives, suggesting there could be a build-up of CO2 load with repeated dives. Although we saw no evidence of CO2 limiting dive behaviour, the longer time required to remove CO2 may eventually exhibit control over the overall time they can spend in apnoea and overall foraging duration.

  4. CO2 enhancement of forest productivity constrained by limited nitrogen availability. (United States)

    Norby, Richard J; Warren, Jeffrey M; Iversen, Colleen M; Medlyn, Belinda E; McMurtrie, Ross E


    Stimulation of terrestrial plant production by rising CO(2) concentration is projected to reduce the airborne fraction of anthropogenic CO(2) emissions. Coupled climate-carbon cycle models are sensitive to this negative feedback on atmospheric CO(2), but model projections are uncertain because of the expectation that feedbacks through the nitrogen (N) cycle will reduce this so-called CO(2) fertilization effect. We assessed whether N limitation caused a reduced stimulation of net primary productivity (NPP) by elevated atmospheric CO(2) concentration over 11 y in a free-air CO(2) enrichment (FACE) experiment in a deciduous Liquidambar styraciflua (sweetgum) forest stand in Tennessee. During the first 6 y of the experiment, NPP was significantly enhanced in forest plots exposed to 550 ppm CO(2) compared with NPP in plots in current ambient CO(2), and this was a consistent and sustained response. However, the enhancement of NPP under elevated CO(2) declined from 24% in 2001-2003 to 9% in 2008. Global analyses that assume a sustained CO(2) fertilization effect are no longer supported by this FACE experiment. N budget analysis supports the premise that N availability was limiting to tree growth and declining over time--an expected consequence of stand development, which was exacerbated by elevated CO(2). Leaf- and stand-level observations provide mechanistic evidence that declining N availability constrained the tree response to elevated CO(2); these observations are consistent with stand-level model projections. This FACE experiment provides strong rationale and process understanding for incorporating N limitation and N feedback effects in ecosystem and global models used in climate change assessments.

  5. Towards Overhauser DNP in supercritical CO(2). (United States)

    van Meerten, S G J; Tayler, M C D; Kentgens, A P M; van Bentum, P J M


    Overhauser Dynamic Nuclear Polarization (ODNP) is a well known technique to improve NMR sensitivity in the liquid state, where the large polarization of an electron spin is transferred to a nucleus of interest by cross-relaxation. The efficiency of the Overhauser mechanism for dipolar interactions depends critically on fast local translational dynamics at the timescale of the inverse electron Larmor frequency. The maximum polarization enhancement that can be achieved for (1)H at high magnetic fields benefits from a low viscosity solvent. In this paper we investigate the option to use supercritical CO2 as a solvent for Overhauser DNP. We have investigated the diffusion constants and longitudinal nuclear relaxation rates of toluene in high pressure CO2. The change in (1)H T1 by addition of TEMPO radical was analyzed to determine the Overhauser cross-relaxation in such a mixture, and is compared with calculations based on the Force Free Hard Sphere (FFHS) model. By analyzing the relaxation data within this model we find translational correlation times in the range of 2-4ps, depending on temperature, pressure and toluene concentration. Such short correlation times may be instrumental for future Overhauser DNP applications at high magnetic fields, as are commonly used in NMR. Preliminary DNP experiments have been performed at 3.4T on high pressure superheated water and model systems such as toluene in high pressure CO2. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Martian Gullies: Formation by CO2 Fluidification (United States)

    Cedillo-Flores, Y.; Durand-Manterola, H. J.


    Some of the geomorphological features in Mars are the gullies. Some theories developed tried explain its origin, either by liquid water, liquid carbon dioxide or flows of dry granular material. We made a comparative analysis of the Martian gullies with the terrestrial ones. We propose that the mechanism of formation of