WorldWideScience

Sample records for high co2 levels

  1. Effects of high CO2 levels on dynamic photosynthesis: carbon gain, mechanisms, and environmental interactions.

    Science.gov (United States)

    Tomimatsu, Hajime; Tang, Yanhong

    2016-05-01

    Understanding the photosynthetic responses of terrestrial plants to environments with high levels of CO2 is essential to address the ecological effects of elevated atmospheric CO2. Most photosynthetic models used for global carbon issues are based on steady-state photosynthesis, whereby photosynthesis is measured under constant environmental conditions; however, terrestrial plant photosynthesis under natural conditions is highly dynamic, and photosynthetic rates change in response to rapid changes in environmental factors. To predict future contributions of photosynthesis to the global carbon cycle, it is necessary to understand the dynamic nature of photosynthesis in relation to high CO2 levels. In this review, we summarize the current body of knowledge on the photosynthetic response to changes in light intensity under experimentally elevated CO2 conditions. We found that short-term exposure to high CO2 enhances photosynthetic rate, reduces photosynthetic induction time, and reduces post-illumination CO2 burst, resulting in increased leaf carbon gain during dynamic photosynthesis. However, long-term exposure to high CO2 during plant growth has varying effects on dynamic photosynthesis. High levels of CO2 increase the carbon gain in photosynthetic induction in some species, but have no significant effects in other species. Some studies have shown that high CO2 levels reduce the biochemical limitation on RuBP regeneration and Rubisco activation during photosynthetic induction, whereas the effects of high levels of CO2 on stomatal conductance differ among species. Few studies have examined the influence of environmental factors on effects of high levels of CO2 on dynamic photosynthesis. We identified several knowledge gaps that should be addressed to aid future predictions of photosynthesis in high-CO2 environments.

  2. Interactive effects of high CO2 and SO2 on growth and antioxidant levels in wheat

    NARCIS (Netherlands)

    Rao, M.V.; De Kok, L.J.

    1994-01-01

    The impact of elevated CO2 and/or SO2 on the growth and antioxidant levels of wheat {Triticum aestivum L. cv. Urban) plants has been studied. High CO2 (0.7 ml I-1) significantly enhanced shoot biomass and photosynthetic capacity, while exposure to SO2 (0.14 ul I-1) resulted in a decreased shoot

  3. Behavioural disturbances in a temperate fish exposed to sustained high-CO2 levels.

    Directory of Open Access Journals (Sweden)

    Fredrik Jutfelt

    Full Text Available As atmospheric CO2 levels rise, the CO2 concentration in ocean surface waters increases through a process commonly referred to as ocean acidification. Recently, surprising behavioural modifications has been detected in the early life stages of tropical coral reef fish exposed to ocean acidification-relevant CO2 concentrations, but it has been unclear if this effect could occur in temperate waters. Here we show several severe behavioural disturbances, including effects on boldness, exploratory behaviour, lateralisation, and learning in a temperate fish, the three-spined stickleback (Gasterosteus aculeatus. The behavioural effects were consistent throughout the exposure period and increased in effect size with exposure time. We observed the effects on adult sticklebacks, a species known to be tolerant to other environmental stressors. Our findings suggest that behavioural abnormalities that stem from CO2 exposure are not restricted to sensitive tropical species or early life stages and may therefore affect fish on a global scale. The severity of disturbances and the possibility of a serious behavioural problem for fish across the globe is cause for concern.

  4. Changing noise levels in a high CO2/lower pH ocean

    Science.gov (United States)

    Brewer, P. G.; Hester, K. C.; Peltzer, E. T.; Kirkwood, W. J.

    2008-12-01

    We show that ocean acidification from fossil fuel CO2 invasion and from increased respiration/reduced ventilation, has significantly reduced ocean sound absorption and thus increased ocean noise levels in the kHz frequency range. Below 10 kHz, sound absorption occurs due to well known chemical relaxations in the B(OH)3/B(OH)4- and HCO3-/CO32- systems. The pH dependence of these chemical relaxations results in decreased sound absorption (α = dB/km) as the ocean becomes more acidic from increased CO2 levels. The scale of surface ocean pH change today from the +105 ppmv change in atmospheric CO2 is about - 0.12 pH, resulting in frequency dependent decreases in sound absorption that now exceed 12% over pre- industrial. Under reasonable projections of future fossil fuel CO2 emissions and other sources a pH change of 0.3 units or more can be anticipated by mid-century, resulting in a decrease in α by almost 40%. Increases in water temperature have a smaller effect but also contribute to decreased sound absorption. Combining a lowering of 0.3 pH units with an increase of 3°C, α will decrease further to almost 45%. Ambient noise levels in the ocean within the auditory range critical for environmental, military, and economic interests are set to increase significantly due to the combined effects of decreased absorption and increasing sources from mankind's activities. Incorporation of sound absorption in modeling future ocean scenarios (R. Zeebe, personal communication) and long-term monitoring possibly with the aid of modern cabled observatories can give insights in how ocean noise will continue to change and its effect on groups such as marine mammals which communicate in the affected frequency range.

  5. 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

    2010-11-01

    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.

  6. Lifetime-based optical sensor for high-level pCO2 detection employing fluorescence resonance energy transfer

    International Nuclear Information System (INIS)

    Bueltzingsloewen, Christoph von; McEvoy, Aisling K.; McDonagh, Colette; MacCraith, Brian D.

    2003-01-01

    An optical sensor for the measurement of high levels of carbon dioxide in gas phase has been developed. It is based on fluorescence resonance energy transfer (FRET) between a long-lifetime ruthenium polypyridyl complex and the pH-active disazo dye Sudan III. The donor luminophore and the acceptor dye are both immobilised in a hydrophobic silica sol-gel/ethyl cellulose hybrid matrix material. Tetraoctylammonium hydroxide (TOA-OH) is used as an internal buffering system. Fluorescence lifetime is measured in the frequency domain, using low-cost phase modulation measurement technology. The use of Sudan III as an acceptor dye has enabled the sensor to have a dynamic range up to 100% carbon dioxide. The sensor displays 11.2 deg. phase shift between the limit of detection (LOD) of 0.06 and 100% CO 2 with a resolution of better than 2%. The encapsulation in the silica/polymer hybrid material has provided the sensor with good mechanical and chemical stability. The effect of molecular oxygen, humidity and temperature on the sensor performance was studied in detail

  7. Highly dissipative Hénon map behavior in the four-level model of the CO 2 laser with modulated losses

    Science.gov (United States)

    Pando L., C. L.; Acosta, G. A. Luna; Meucci, R.; Ciofini, M.

    1995-02-01

    We show that the four-level model for the CO 2 laser with modulated losses behaves in a qualitatively similar way as the highly dissipative Hénon map. The ubiquity of elements of the universal sequence, their related symbolic dynamics, and the presence of reverse bifurcations of chaotic bands in the model are reminiscent of the logistic map which is the limit of the Hénon map when the Jacobian equals zero. The coexistence of attractors, its dynamics related to contraction of volumes in phase space and the associated return maps can be correlated with those of the highly dissipative Hénon map.

  8. Calcification in Caribbean reef-building corals at high pCO2 levels in a recirculating ocean acidification exposure system

    Science.gov (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...

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

    Directory of Open Access Journals (Sweden)

    Adam eMonier

    2014-09-01

    Full Text Available 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.

  10. High-powered CO2 -lasers and noise control

    Science.gov (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.

  11. Effects of tillage practice and atmospheric CO2 level on soil CO2 efflux

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) affects both the quantity and quality of plant tissues, which impacts the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research to accurately quantify the effects of elevated CO2 and as...

  12. Rising CO2 levels will intensify phytoplankton blooms in eutrophic and hypertrophic lakes.

    Directory of Open Access Journals (Sweden)

    Jolanda M H Verspagen

    Full Text Available 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

  13. Rising CO2 Levels Will Intensify Phytoplankton Blooms in Eutrophic and Hypertrophic Lakes

    Science.gov (United States)

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

    2014-01-01

    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

  14. Achievement report for fiscal 2000 on research and development of high level waste glass utilization system of CO2 emission suppression type; 2000 nendo CO2 haishutsu yokuseigata hai glass kodo riyo system no kenkyu kaihatsu seika hokokusho (kokaiyo)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    With an objective to establish a waste glass recycling system of low cost and requiring less CO2 emission amount and energy consumption, research and development has been made on classification of waste glasses into particle composition that is required in regenerated commercial products. This paper summarizes the achievements in fiscal 2000. In the research of a waste glass reusing and supplying system designed by using LCA, discussions were given on items required in circulating and recycling waste glass resources, and quality control on raw materials and products. Evaluations of product quality control items were made on crystallized glass, sintered glasswool, automotive window glass, electric bulbs, fluorescent lamp glass, and quartz glass. Utilization tests were carried out for Mashiko porcelain china clay with an intention of expanding the application of waste glass, whereas the relationship between waste glass addition amount and optimal sintering temperature range was verified, disclosing that the limit of the waste glass addition is 10%. In the research on multi-functional hybrid materials, discussions were given on light-weight tiles and water permeating blocks with regard to the manufacturing technology, facility specifications, product quality, effects of the functions, and durability. (NEDO)

  15. 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.

    of marine plankton to increasing CO2 concentrations. Natural water samples from the coastal Bay of Bengal were incubated under the ambient condition and high CO2 levels (703-711 latm) for 5 days in May and June 2010. A significant negative correlation...

  16. Temperature dependence of the photodissociation of CO2 from high vibrational levels: 205-230 nm imaging studies of CO(X1Σ+) and O(3P, 1D) products

    Science.gov (United States)

    Sutradhar, S.; Samanta, B. R.; Samanta, A. K.; Reisler, H.

    2017-07-01

    The 205-230 nm photodissociation of vibrationally excited CO2 at temperatures up to 1800 K was studied using Resonance Enhanced Multiphoton Ionization (REMPI) and time-sliced Velocity Map Imaging (VMI). CO2 molecules seeded in He were heated in an SiC tube attached to a pulsed valve and supersonically expanded to create a molecular beam of rotationally cooled but vibrationally hot CO2. Photodissociation was observed from vibrationally excited CO2 with internal energies up to about 20 000 cm-1, and CO(X1Σ+), O(3P), and O(1D) products were detected by REMPI. The large enhancement in the absorption cross section with increasing CO2 vibrational excitation made this investigation feasible. The internal energies of heated CO2 molecules that absorbed 230 nm radiation were estimated from the kinetic energy release (KER) distributions of CO(X1Σ+) products in v″ = 0. At 230 nm, CO2 needs to have at least 4000 cm-1 of rovibrational energy to absorb the UV radiation and produce CO(X1Σ+) + O(3P). CO2 internal energies in excess of 16 000 cm-1 were confirmed by observing O(1D) products. It is likely that initial absorption from levels with high bending excitation accesses both the A1B2 and B1A2 states, explaining the nearly isotropic angular distributions of the products. CO(X1Σ+) product internal energies were estimated from REMPI spectroscopy, and the KER distributions of the CO(X1Σ+), O(3P), and O(1D) products were obtained by VMI. The CO product internal energy distributions change with increasing CO2 temperature, suggesting that more than one dynamical pathway is involved when the internal energy of CO2 (and the corresponding available energy) increases. The KER distributions of O(1D) and O(3P) show broad internal energy distributions in the CO(X1Σ+) cofragment, extending up to the maximum allowed by energy but peaking at low KER values. Although not all the observations can be explained at this time, with the aid of available theoretical studies of CO2 VUV

  17. CO2-Philic polymer membrane with extremely high separation performance

    KAUST Repository

    Yave, Wilfredo

    2010-01-12

    Polymeric membranes are attractive for CO2 separation and concentration from different gas streams because of their versatility and energy efficiency; they can compete with, and they may even replace, traditional absorption processes. Here we describe a simple and powerful method for developing nanostructured and CO2-philic polymer membranes for CO2 separation. A poly(ethylene oxide)-poly(butylene terephthalate) multiblock copolymer is used as membrane material. Smart additives such as polyethylene glycol dibutyl ether are incorporated as spacers or fillers for producing nanostructured materials. The addition of these specific additives produces CO2-philic membranes and increases the CO2 permeability (750 barrer) up to five-fold without the loss of selectivity. The membranes present outstanding performance for CO2 separation, and the measured CO2 flux is extremely high ( > 2 m3 m -2 h-1 bar-1) with selectivity over H2 and N2 of 10 and 40, respectively, making them attractive for CO 2 capture. © 2009 American Chemical Society.

  18. CO2-Philic polymer membrane with extremely high separation performance

    KAUST Repository

    Yave, Wilfredo; Car, Anja; Funari, S.; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

    2010-01-01

    Polymeric membranes are attractive for CO2 separation and concentration from different gas streams because of their versatility and energy efficiency; they can compete with, and they may even replace, traditional absorption processes. Here we describe a simple and powerful method for developing nanostructured and CO2-philic polymer membranes for CO2 separation. A poly(ethylene oxide)-poly(butylene terephthalate) multiblock copolymer is used as membrane material. Smart additives such as polyethylene glycol dibutyl ether are incorporated as spacers or fillers for producing nanostructured materials. The addition of these specific additives produces CO2-philic membranes and increases the CO2 permeability (750 barrer) up to five-fold without the loss of selectivity. The membranes present outstanding performance for CO2 separation, and the measured CO2 flux is extremely high ( > 2 m3 m -2 h-1 bar-1) with selectivity over H2 and N2 of 10 and 40, respectively, making them attractive for CO 2 capture. © 2009 American Chemical Society.

  19. Compact, High Accuracy CO2 Monitor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase I proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

  20. Compact, High Accuracy CO2 Monitor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovative Research Phase II proposal seeks to develop a low cost, robust, highly precise and accurate CO2 monitoring system. This system will...

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

    KAUST Repository

    Burdett, HL

    2017-11-23

    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.

  2. Development of high power pulsed CO2 laser

    International Nuclear Information System (INIS)

    Nakai, Sadao; Matoba, Masafumi; Fujita, Hisanori; Daido, Hiroyuki; Inoue, Mitsuo

    1982-01-01

    The inertial nuclear fusion research using pellet implosion has rapidly progressed accompanying laser technique improvement and output increase. As the high output lasers for this purpose, Nd glass lasers or CO 2 lasers are used. The CO 2 lasers possess the characteristics required as reactor lasers, i.e., high efficiency, high frequency repetition, possibility of scale-up and economy. So, the technical development of high power CO 2 lasers assuming also as reactor drivers has been performed at a quick pace together with the research on the improvement of efficiency of pellet implosion by 10 μm laser beam. The Institute of Laser Engineering, Osaka University, stated to build a laser system LEKKO No. 8 of 8 beams and 10 kJ based on the experiences in laser systems LEKKO No. 1 and LEKKO No. 2, and the system LEKKO No. 8 was completed in March, 1981. The operation tests for one year since then has indicated as the laser characteristics that the system performance was as designed initially. This paper reviews the structure, problems and present status of the large scale CO 2 lasers. In other words, the construction of laser system, CO 2 laser proper, oscillator, booster amplifier, prevention of parasitic oscillation, non-linear pulse propagation and fairing of output pulse form, system control and beam alignment, and high power problems are described. The results obtained are to be reported in subsequent issues. (Wakatsuki, Y.)

  3. System-level modeling for geological storage of CO2

    OpenAIRE

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

    2006-01-01

    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...

  4. CO2 and nutrient-driven changes across multiple levels of organization in Zostera noltii ecosystems

    Science.gov (United States)

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

    2014-12-01

    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

  5. Physiological and molecular alterations in plants exposed to high [CO2] under phosphorus stress.

    Science.gov (United States)

    Pandey, Renu; Zinta, Gaurav; AbdElgawad, Hamada; Ahmad, Altaf; Jain, Vanita; Janssens, Ivan A

    2015-01-01

    Atmospheric [CO2] has increased substantially in recent decades and will continue to do so, whereas the availability of phosphorus (P) is limited and unlikely to increase in the future. P is a non-renewable resource, and it is essential to every form of life. P is a key plant nutrient controlling the responsiveness of photosynthesis to [CO2]. Increases in [CO2] typically results in increased biomass through stimulation of net photosynthesis, and hence enhance the demand for P uptake. However, most soils contain low concentrations of available P. Therefore, low P is one of the major growth-limiting factors for plants in many agricultural and natural ecosystems. The adaptive responses of plants to [CO2] and P availability encompass alterations at morphological, physiological, biochemical and molecular levels. In general low P reduces growth, whereas high [CO2] enhances it particularly in C3 plants. Photosynthetic capacity is often enhanced under high [CO2] with sufficient P supply through modulation of enzyme activities involved in carbon fixation such as ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, high [CO2] with low P availability results in enhanced dry matter partitioning towards roots. Alterations in below-ground processes including root morphology, exudation and mycorrhizal association are influenced by [CO2] and P availability. Under high P availability, elevated [CO2] improves the uptake of P from soil. In contrast, under low P availability, high [CO2] mainly improves the efficiency with which plants produce biomass per unit P. At molecular level, the spatio-temporal regulation of genes involved in plant adaptation to low P and high [CO2] has been studied individually in various plant species. Genome-wide expression profiling of high [CO2] grown plants revealed hormonal regulation of biomass accumulation through complex transcriptional networks. Similarly, differential transcriptional regulatory networks are involved in P

  6. CO2 emissions: a peak level in 2010

    International Nuclear Information System (INIS)

    Anon.

    2011-01-01

    After a reduction of CO 2 emissions in 2009 due to the financial crisis, these emissions have again reached a peak in 2010: 30.6 Gt, it means an increase by 5% compared to the previous peak. According to IEA (International Energy Agency): 44% of the emissions come from coal, 36% from oil and 20% from natural gas, and OECD countries are responsible of 40% of the CO 2 global emissions but only of 25% of their increase since 2009. For China and India the emissions of CO 2 have increased sharply due to their strong economic growth. (A.C.)

  7. Annual CO2 budget and seasonal CO2 exchange signals at a high Arctic permafrost site on Spitsbergen, Svalbard archipelago

    DEFF Research Database (Denmark)

    Luërs, J.; Westermann, Signe; Piel, K.

    2014-01-01

    -lasting snow cover, and several months of darkness. This study presents a complete annual cycle of the CO2 net ecosystem exchange (NEE) dynamics for a high Arctic tundra area at the west coast of Svalbard based on eddy covariance flux measurements. The annual cumulative CO2 budget is close to 0 g C m-2 yr-1...

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

    Directory of Open Access Journals (Sweden)

    S. Saravanan

    2014-08-01

    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.

  9. Acclimation to high CO2 in maize is related to water status and dependent on leaf rank.

    Science.gov (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

    2011-02-01

    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.

  10. CO2 as an Oxidant for High Temperature Reactions

    Directory of Open Access Journals (Sweden)

    Sibudjing eKawi

    2015-03-01

    Full Text Available This paper presents a review on the developments in catalyst technology for the reactions utilizing CO2 for high temperature applications. These include dehydrogenation of alkanes to olefins, the dehydrogenation of ethylbenzene to styrene and finally CO2 reforming of hydrocarbon feedstock (i.e. methane and alcohols. Aspects on the various reaction pathways are also highlighted. The literature on the role of promoters and catalyst development is critically evaluated. Most of the reactions discussed in this review are exploited in industries and related to on-going processes, thus providing extensive data from literature. However some reactions, such as CO2 reforming of ethanol and glycerol which have not reached industrial scale are also reviewed owing to their great potential in terms of sustainability which are essential as energy for the future. This review further illustrates the building-up of knowledge which shows the role of support and catalysts for each reaction and the underlying linkage between certain catalysts which can be adapted for the multiple CO2-related reactions.

  11. CO2 sequestration in two mediterranean dune areas subjected to a different level of anthropogenic disturbance

    Science.gov (United States)

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

    2017-09-01

    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.

  12. The effect of light level, CO2 flow rate, and anesthesia on the stress response of mice during CO2 euthanasia.

    Science.gov (United States)

    Powell, Karin; Ethun, Kelly; Taylor, Douglas K

    2016-09-21

    Euthanasia protocols are designed to mitigate the stress experienced by animals, and an environment that induces minimal stress helps achieve that goal. A protocol that is efficient and practical in a typical animal research facility is also important. Light intensity, isoflurane, and CO2 flow rate were studied for their impact on the stress response of mice during CO2 euthanasia. Behavior was observed and scored during euthanasia and serum corticosterone was measured immediately after death. Unsurprisingly, animals euthanized with a high-flow rate of CO2 became unconscious in the least amount of time, while animals euthanized with a low-flow rate required the most time to reach unconsciousness. There was a significant increase in anxious behaviors in animals in the isoflurane group (F1,12 = 6.67, P = 0.024), the high-flow rate CO2 group (F1,12 = 10.24, P = 0.007), and bright chamber group (F1,12 = 7.27, P = 0.019). Serum corticosterone was highest in the isoflurane group (124.72 ± 83.98 ng/ml), however there was no significant difference in corticosterone levels observed for the other study variables of light and flow-rate. A darkened chamber and low CO2 flow rates help to decrease stress experienced during CO2 euthanasia, while the use of isoflurane was observed to increase the stress response during euthanasia.

  13. Annual CO2 budget and seasonal CO2 exchange signals at a High Arctic permafrost site on Spitsbergen, Svalbard archipelago

    Science.gov (United States)

    Lüers, J.; Westermann, S.; Piel, K.; Boike, J.

    2014-01-01

    The annual variability of CO2 exchange in most ecosystems is primarily driven by the activities of plants and soil microorganisms. However, little is known about the carbon balance and its controlling factors outside the growing season in arctic regions dominated by soil freeze/thaw-processes, long-lasting snow cover, and several months of darkness. This study presents a complete annual cycle of the CO2 net ecosystem exchange (NEE) dynamics for a High Arctic tundra area on the west coast of Svalbard based on eddy-covariance flux measurements. The annual cumulative CO2 budget is close to zero grams carbon per square meter per year, but shows a very strong seasonal variability. Four major CO2 exchange seasons have been identified. (1) During summer (ground snow-free), the CO2 exchange occurs mainly as a result of biological activity, with a predominance of strong CO2 assimilation by the ecosystem. (2) The autumn (ground snow-free or partly snow-covered) is dominated by CO2 respiration as a result of biological activity. (3) In winter and spring (ground snow-covered), low but persistent CO2 release occur, overlain by considerable CO2 exchange events in both directions associated with changes of air masses and air and atmospheric CO2 pressure. (4) The snow melt season (pattern of snow-free and snow-covered areas), where both, meteorological and biological forcing, resulting in a visible carbon uptake by the high arctic ecosystem. Data related to this article are archived under: http://doi.pangaea.de/10.1594/PANGAEA.809507.

  14. Coral energy reserves and calcification in a high-CO2 world at two temperatures.

    Directory of Open Access Journals (Sweden)

    Verena Schoepf

    Full Text Available Rising atmospheric CO2 concentrations threaten coral reefs globally by causing ocean acidification (OA and warming. Yet, the combined effects of elevated pCO2 and temperature on coral physiology and resilience remain poorly understood. While coral calcification and energy reserves are important health indicators, no studies to date have measured energy reserve pools (i.e., lipid, protein, and carbohydrate together with calcification under OA conditions under different temperature scenarios. Four coral species, Acropora millepora, Montipora monasteriata, Pocillopora damicornis, Turbinaria reniformis, were reared under a total of six conditions for 3.5 weeks, representing three pCO2 levels (382, 607, 741 µatm, and two temperature regimes (26.5, 29.0 °C within each pCO2 level. After one month under experimental conditions, only A. millepora decreased calcification (-53% in response to seawater pCO2 expected by the end of this century, whereas the other three species maintained calcification rates even when both pCO2 and temperature were elevated. Coral energy reserves showed mixed responses to elevated pCO2 and temperature, and were either unaffected or displayed nonlinear responses with both the lowest and highest concentrations often observed at the mid-pCO2 level of 607 µatm. Biweekly feeding may have helped corals maintain calcification rates and energy reserves under these conditions. Temperature often modulated the response of many aspects of coral physiology to OA, and both mitigated and worsened pCO2 effects. This demonstrates for the first time that coral energy reserves are generally not metabolized to sustain calcification under OA, which has important implications for coral health and bleaching resilience in a high-CO2 world. Overall, these findings suggest that some corals could be more resistant to simultaneously warming and acidifying oceans than previously expected.

  15. 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

    2017-01-01

    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

  16. Low coral cover in a high-CO2 world

    Science.gov (United States)

    Hoegh-Guldberg, Ove

    2005-09-01

    Coral reefs generally exist within a relatively narrow band of temperatures, light, and seawater aragonite saturation states. The growth of coral reefs is minimal or nonexistent outside this envelope. Climate change, through its effect on ocean temperature, has already had an impact on the world's coral reefs, with almost 30% of corals having disappeared since the beginning of the 1980s. Abnormally warm temperatures cause corals to bleach (lose their brown dinoflagellate symbionts) and, if elevated for long enough, to die. Increasing atmospheric CO2 is also potentially affecting coral reefs by lowering the aragonite saturation state of seawater, making carbonate ions less available for calcification. The synergistic interaction of elevated temperature and CO2 is likely to produce major changes to coral reefs over the next few decades and centuries. Known tolerances of corals to projected changes to sea temperatures indicate that corals are unlikely to remain abundant on reefs and could be rare by the middle of this century if the atmospheric CO2 concentration doubles or triples. The combination of changes to sea temperature and carbonate ion availability could trigger large-scale changes in the biodiversity and function of coral reefs. The ramifications of these changes for the hundred of millions of coral reef-dependent people and industries living in a high-CO2 world have yet to be properly defined. The weight of evidence suggests, however, that projected changes will cause major shifts in the prospects for industries and societies that depend on having healthy coral reefs along their coastlines.

  17. Thermodynamic and Kinetic Response of Microbial Reactions to High CO2.

    Science.gov (United States)

    Jin, Qusheng; Kirk, Matthew F

    2016-01-01

    Geological carbon sequestration captures CO 2 from industrial sources and stores the CO 2 in subsurface reservoirs, a viable strategy for mitigating global climate change. In assessing the environmental impact of the strategy, a key question is how microbial reactions respond to the elevated CO 2 concentration. This study uses biogeochemical modeling to explore the influence of CO 2 on the thermodynamics and kinetics of common microbial reactions in subsurface environments, including syntrophic oxidation, iron reduction, sulfate reduction, and methanogenesis. The results show that increasing CO 2 levels decreases groundwater pH and modulates chemical speciation of weak acids in groundwater, which in turn affect microbial reactions in different ways and to different extents. Specifically, a thermodynamic analysis shows that increasing CO 2 partial pressure lowers the energy available from syntrophic oxidation and acetoclastic methanogenesis, but raises the available energy of microbial iron reduction, hydrogenotrophic sulfate reduction and methanogenesis. Kinetic modeling suggests that high CO 2 has the potential of inhibiting microbial sulfate reduction while promoting iron reduction. These results are consistent with the observations of previous laboratory and field studies, and highlight the complexity in microbiological responses to elevated CO 2 abundance, and the potential power of biogeochemical modeling in evaluating and quantifying these responses.

  18. Thermodynamic and kinetic response of microbial reactions to high CO2

    Directory of Open Access Journals (Sweden)

    Qusheng Jin

    2016-11-01

    Full Text Available Geological carbon sequestration captures CO2 from industrial sources and stores the CO2 in subsurface reservoirs, a viable strategy for mitigating global climate change. In assessing the environmental impact of the strategy, a key question is how microbial reactions respond to the elevated CO2 concentration. This study uses biogeochemical modeling to explore the influence of CO2 on the thermodynamics and kinetics of common microbial reactions in subsurface environments, including syntrophic oxidation, iron reduction, sulfate reduction, and methanogenesis. The results show that increasing CO2 levels decreases groundwater pH and modulates chemical speciation of weak acids in groundwater, which in turn affect microbial reactions in different ways and to different extents. Specifically, a thermodynamic analysis shows that increasing CO2 partial pressure lowers the energy available from syntrophic oxidation and acetoclastic methanogenesis, but raises the available energy of microbial iron reduction, hydrogenotrophic sulfate reduction and methanogenesis. Kinetic modeling suggests that high CO2 has the potential of inhibiting microbial sulfate reduction while promoting iron reduction. These results are consistent with the observations of previous laboratory and field studies, and highlight the complexity in microbiological responses to elevated CO2 abundance, and the potential power of biogeochemical modeling in evaluating and quantifying these responses.

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

    Directory of Open Access Journals (Sweden)

    Jae-Sol Choi

    2018-04-01

    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.

  20. Material Processing with High Power CO2-Lasers

    Science.gov (United States)

    Bakowsky, Lothar

    1986-10-01

    After a period of research and development lasertechnique now is regarded as an important instrument for flexible, economic and fully automatic manufacturing. Especially cutting of flat metal sheets with high power C02-lasers and CNC controlled two or three axes handling systems is a wide spread. application. Three dimensional laser cutting, laser-welding and -heat treatment are just at the be ginning of industrial use in production lines. The main. advantages of laser technology. are - high. accuracy - high, processing velocity - law thermal distortion. - no tool abrasion. The market for laser material processing systems had 1985 a volume of 300 Mio S with growth rates between, 20 % and 30 %. The topic of this lecture are hiTrh. power CO2-lasers. Besides this systems two others are used as machining tools, Nd-YAG- and Eximer lasers. All applications of high. power CO2-lasers to industrial material processing show that high processing velocity and quality are only guaranteed in case of a stable intensity. profile on the workpiece. This is only achieved by laser systems without any power and mode fluctuations and by handling systems of high accuracy. Two applications in the automotive industry are described, below as examples for laser cutting and laser welding of special cylindrical motor parts.

  1. CO2 Fluxes Monitoring at the Level of Field Agroecosystem in Moscow Region of Russia

    Science.gov (United States)

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

    2014-05-01

    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

  2. Investigational study of the CO2 balance in high temperature CO2 separation technology; Nisanka tanso koon bunri gijutsu ni okeru CO2 balance ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    An investigational study was conducted to clarify the adaptable environment and effectivity of technologies of high temperature separation/recovery/reutilization of CO2. In the study, data collection, arrangement and comparison were made of various separation technologies such as the membrane method, absorption method, adsorption method, and cryogenic separation method. With the LNG-fired power generation as an example, the adaptable environment and effectivity were made clear by making models by a process simulator, ASPEN PLUS. Moreover, using this simulator, effects of replacing the conventional steam reforming of hydrocarbon with the CO2 reforming were made clear with the methanol synthesis as an example. As to the rock fixation treatment of high temperature CO2, collection/arrangement were made of the data on the fixation treatment of the CO2 separated at high temperature into basic rocks such as peridotite and serpentinite in order to clarify the adaptable environment and effectivity of the treatment. Besides, a potentiality of the fixation to concrete waste was made clear. 57 refs., 57 figs., 93 tabs.

  3. Effects of long-term high CO2 exposure on two species of coccolithophores

    Directory of Open Access Journals (Sweden)

    K. G. Schulz

    2010-03-01

    Full Text Available The physiological performance of two coccolithophore species, Emiliania huxleyi and Coccolithus braarudii, was investigated during long-term exposure to elevated pCO2 levels. Mono-specific cultures were grown over 152 (E. huxleyi and 65 (C. braarudii generations while pCO2 was gradually increased to maximum levels of 1150 μatm (E. huxleyi and 930 μatm (C. braarudii and kept constant thereafter. Rates of cell growth and cell quotas of particulate organic carbon (POC, particulate inorganic carbon (PIC and total particulate nitrogen (TPN were determined repeatedly throughout the incubation period. Increasing pCO2 caused a decrease in cell growth rate of 9% and 29% in E. huxleyi and C. braarudii, respectively. In both species cellular PIC:TPN and PIC:POC ratios decreased in response to rising pCO2, whereas no change was observed in the POC:TPN ratios of E. huxleyi and C. braarudii. These results are consistent with those obtained in shorter-term high CO2 exposure experiments following abrupt pertubations of the seawater carbonate system and indicate that for the strains tested here a gradual CO2 increase does not alleviate CO2/pH sensitivity.

  4. Painted Goby Larvae under High-CO2 Fail to Recognize Reef Sounds.

    Directory of Open Access Journals (Sweden)

    Joana M Castro

    Full Text Available Atmospheric CO2 levels have been increasing at an unprecedented rate due to anthropogenic activity. Consequently, ocean pCO2 is increasing and pH decreasing, affecting marine life, including fish. For many coastal marine fishes, selection of the adult habitat occurs at the end of the pelagic larval phase. Fish larvae use a range of sensory cues, including sound, for locating settlement habitat. This study tested the effect of elevated CO2 on the ability of settlement-stage temperate fish to use auditory cues from adult coastal reef habitats. Wild late larval stages of painted goby (Pomatoschistus pictus were exposed to control pCO2 (532 μatm, pH 8.06 and high pCO2 (1503 μatm, pH 7.66 conditions, likely to occur in nearshore regions subjected to upwelling events by the end of the century, and tested in an auditory choice chamber for their preference or avoidance to nighttime reef recordings. Fish reared in control pCO2 conditions discriminated reef soundscapes and were attracted by reef recordings. This behaviour changed in fish reared in the high CO2 conditions, with settlement-stage larvae strongly avoiding reef recordings. This study provides evidence that ocean acidification might affect the auditory responses of larval stages of temperate reef fish species, with potentially significant impacts on their survival.

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

    NARCIS (Netherlands)

    Kouwenberg, L.L.R.

    1973-01-01

    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

  6. Deep Sea Memory of High Atmospheric CO2 Concentration

    Science.gov (United States)

    Mathesius, Sabine; Hofmann, Matthias; Caldeira, Ken; Schellnhuber, Hans Joachim

    2015-04-01

    massive CDR interventions eventually bring down the global mean pH value to the RCP2.6 level, yet cannot restore a similarly homogenous distribution - while the pH of the upper ocean returns to the preindustrial value or even exceed it (in the 180 ppm scenario), the deep ocean remains acidified. The deep ocean is out of contact with the atmosphere and therefore unreachable by atmospheric CDR. Our results suggest that the proposition that the marine consequences of early emissions reductions are comparable to those of delayed reductions plus CDR is delusive and that a policy that allows for emitting CO2 today in the hopes of removing it tomorrow is bound to generate substantial regrets.

  7. Carbon dioxide sensing in the social context: Leaf-cutting ants prefer elevated CO2 levels to tend their brood.

    Science.gov (United States)

    Römer, Daniela; Bollazzi, Martin; Roces, Flavio

    2018-05-18

    Social insects show temperature and humidity preferences inside their nests to successfully rear brood. In underground nests, ants also encounter rising CO 2 concentrations with increasing depth. It is an open question whether they use CO 2 as a cue to decide where to place and tend the brood. Leaf-cutting ants do show CO 2 preferences for the culturing of their symbiotic fungus. We evaluated their CO 2 choices for brood placement in laboratory experiments. Workers of Acromyrmex lundii in the process of relocating brood were offered a binary choice consisting of two interconnected chambers with different CO 2 concentrations. Values ranged from atmospheric to high concentrations of 4% CO 2 . The CO 2 preferences shown by workers for themselves and for brood placement were assessed by quantifying the number of workers and relocated brood in each chamber. Ants showed clear CO 2 preferences for brood placement. They avoided atmospheric levels, 1% and 4% CO 2 , and showed a preference for levels of 3%. This is the first report of CO 2 preferences for the maintenance of brood in social insects. The observed preferences for brood location were independent of the workers' own CO 2 preferences, since they showed no clear-cut pattern. Workers' CO 2 preferences for brood maintenance were slightly higher than those reported for fungus culturing, although brood is reared in the same chambers as the fungus in leaf-cutting ant nests. Workers' choices for brood placement in natural nests are likely the result of competing preferences for other environmental factors more crucial for brood survival, aside from those for CO 2 . Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. 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

    2014-01-01

    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

  9. Meta-analysis reveals profound responses of plant traits to glacial CO2 levels

    OpenAIRE

    Temme, A A; Cornwell, W K; Cornelissen, J H C; Aerts, R

    2013-01-01

    A general understanding of the links between atmospheric CO2 concentration and the functioning of the terrestrial biosphere requires not only an understanding of plant trait responses to the ongoing transition to higher CO2 but also the legacy effects of past low CO2. An interesting question is whether the transition from current to higher CO2 can be thought of as a continuation of the past trajectory of low to current CO2 levels. Determining this trajectory requires quantifying the effect si...

  10. EU's CO2 trade a high risk project

    International Nuclear Information System (INIS)

    Wellander, Dag

    2003-01-01

    The uncertainty about the planned CO 2 trade of the European Union (EU) is very great. For the possible buyers in this politically created market the risks may be great and difficult to assess. The most effective way of forcing a reduction of emissions is trading emission licences. But this requires taking a stand on issues of very unpleasant nature. And the Kyoto protocol evades these questions, it is a thin document right from the beginning. Trade in emission licences is one of the three so-called flexible mechanisms of the Kyoto agreement. The second mechanism is joint implementation in which one industrialized country carries out emission reduction actions in another industrialized country. The third is the mechanism of clean development, in which one industrialized country takes remedial actions in a developing country. It is unclear how these mechanisms are to act in accordance with each other, both in the Kyoto Protocol and on the level of the EU. The biggest and most fundamental uncertainty, both on the EU and global levels, relates to the fact that the partners have not decided how to define the right of ownership of emissions of a certain size

  11. 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

    2014-10-01

    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.

  12. Chemical effects of a high CO2 concentration in oxy-fuel combustion of methane

    DEFF Research Database (Denmark)

    Glarborg, Peter; Bentzen, L.L.B.

    2008-01-01

    The oxidation of methane in an atmospheric-pres sure flow reactor has been studied experimentally under highly diluted conditions in N-2 and CO2, respectively. The stoichiometry was varied from fuel-lean to fuel-rich, and the temperatures covered the range 1200-1800 K. The results were interpreted...... CO2. The high local CO levels may have implications for near-burner corrosion and stagging, but increased problems with CO emission in oxy-fuel combustion are not anticipated....

  13. Sea anemones may thrive in a high CO2 world.

    Science.gov (United States)

    Suggett, David J; Hall-Spencer, Jason M; Rodolfo-Metalpa, Riccardo; Boatman, Toby G; Payton, Ross; Tye Pettay, D; Johnson, Vivienne R; Warner, Mark E; Lawson, Tracy

    2012-10-01

    Increased seawater pCO 2 , and in turn 'ocean acidification' (OA), is predicted to profoundly impact marine ecosystem diversity and function this century. Much research has already focussed on calcifying reef-forming corals (Class: Anthozoa) that appear particularly susceptible to OA via reduced net calcification. However, here we show that OA-like conditions can simultaneously enhance the ecological success of non-calcifying anthozoans, which not only play key ecological and biogeochemical roles in present day benthic ecosystems but also represent a model organism should calcifying anthozoans exist as less calcified (soft-bodied) forms in future oceans. Increased growth (abundance and size) of the sea anemone (Anemonia viridis) population was observed along a natural CO 2 gradient at Vulcano, Italy. Both gross photosynthesis (P G ) and respiration (R) increased with pCO 2 indicating that the increased growth was, at least in part, fuelled by bottom up (CO 2 stimulation) of metabolism. The increase of P G outweighed that of R and the genetic identity of the symbiotic microalgae (Symbiodinium spp.) remained unchanged (type A19) suggesting proximity to the vent site relieved CO 2 limitation of the anemones' symbiotic microalgal population. Our observations of enhanced productivity with pCO 2 , which are consistent with previous reports for some calcifying corals, convey an increase in fitness that may enable non-calcifying anthozoans to thrive in future environments, i.e. higher seawater pCO 2 . Understanding how CO 2 -enhanced productivity of non- (and less-) calcifying anthozoans applies more widely to tropical ecosystems is a priority where such organisms can dominate benthic ecosystems, in particular following localized anthropogenic stress. © 2012 Blackwell Publishing Ltd.

  14. Effect of increased pCO2 level on early shell development in great scallop (Pecten maximus Lamarck larvae

    Directory of Open Access Journals (Sweden)

    S. Andersen

    2013-10-01

    Full Text Available As a result of high anthropogenic CO2 emissions, the concentration of CO2 in the oceans has increased, causing a decrease in pH, known as ocean acidification (OA. Numerous studies have shown negative effects on marine invertebrates, and also that the early life stages are the most sensitive to OA. We studied the effects of OA on embryos and unfed larvae of the great scallop (Pecten maximus Lamarck, at pCO2 levels of 469 (ambient, 807, 1164, and 1599 μatm until seven days after fertilization. To our knowledge, this is the first study on OA effects on larvae of this species. A drop in pCO2 level the first 12 h was observed in the elevated pCO2 groups due to a discontinuation in water flow to avoid escape of embryos. When the flow was restarted, pCO2 level stabilized and was significantly different between all groups. OA affected both survival and shell growth negatively after seven days. Survival was reduced from 45% in the ambient group to 12% in the highest pCO2 group. Shell length and height were reduced by 8 and 15%, respectively, when pCO2 increased from ambient to 1599 μatm. Development of normal hinges was negatively affected by elevated pCO2 levels in both trochophore larvae after two days and veliger larvae after seven days. After seven days, deformities in the shell hinge were more connected to elevated pCO2 levels than deformities in the shell edge. Embryos stained with calcein showed fluorescence in the newly formed shell area, indicating calcification of the shell at the early trochophore stage between one and two days after fertilization. Our results show that P. maximus embryos and early larvae may be negatively affected by elevated pCO2 levels within the range of what is projected towards year 2250, although the initial drop in pCO2 level may have overestimated the effect of the highest pCO2 levels. Future work should focus on long-term effects on this species from hatching, throughout the larval stages, and further into the

  15. High temperature CO2 capture using calcium oxide sorbent in a fixed-bed reactor

    International Nuclear Information System (INIS)

    Dou Binlin; Song Yongchen; Liu Yingguang; Feng Cong

    2010-01-01

    The gas-solid reaction and breakthrough curve of CO 2 capture using calcium oxide sorbent at high temperature in a fixed-bed reactor are of great importance, and being influenced by a number of factors makes the characterization and prediction of these a difficult problem. In this study, the operating parameters on reaction between solid sorbent and CO 2 gas at high temperature were investigated. The results of the breakthrough curves showed that calcium oxide sorbent in the fixed-bed reactor was capable of reducing the CO 2 level to near zero level with the steam of 10 vol%, and the sorbent in CaO mixed with MgO of 40 wt% had extremely low capacity for CO 2 capture at 550 deg. C. Calcium oxide sorbent after reaction can be easily regenerated at 900 deg. C by pure N 2 flow. The experimental data were analyzed by shrinking core model, and the results showed reaction rates of both fresh and regeneration sorbents with CO 2 were controlled by a combination of the surface chemical reaction and diffusion of product layer.

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

    KAUST Repository

    Zakroff, Casey J.

    2013-12-01

    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. High-Throughput Molecular Simulations of Metal Organic Frameworks for CO2 Separation: Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Ilknur Erucar

    2018-02-01

    Full Text Available Metal organic frameworks (MOFs have emerged as great alternatives to traditional nanoporous materials for CO2 separation applications. MOFs are porous materials that are formed by self-assembly of transition metals and organic ligands. The most important advantage of MOFs over well-known porous materials is the possibility to generate multiple materials with varying structural properties and chemical functionalities by changing the combination of metal centers and organic linkers during the synthesis. This leads to a large diversity of materials with various pore sizes and shapes that can be efficiently used for CO2 separations. Since the number of synthesized MOFs has already reached to several thousand, experimental investigation of each MOF at the lab-scale is not practical. High-throughput computational screening of MOFs is a great opportunity to identify the best materials for CO2 separation and to gain molecular-level insights into the structure–performance relationships. This type of knowledge can be used to design new materials with the desired structural features that can lead to extraordinarily high CO2 selectivities. In this mini-review, we focused on developments in high-throughput molecular simulations of MOFs for CO2 separations. After reviewing the current studies on this topic, we discussed the opportunities and challenges in the field and addressed the potential future developments.

  18. High-throughput Molecular Simulations of MOFs for CO2 Separation: Opportunities and Challenges

    Science.gov (United States)

    Erucar, Ilknur; Keskin, Seda

    2018-02-01

    Metal organic frameworks (MOFs) have emerged as great alternatives to traditional nanoporous materials for CO2 separation applications. MOFs are porous materials that are formed by self-assembly of transition metals and organic ligands. The most important advantage of MOFs over well-known porous materials is the possibility to generate multiple materials with varying structural properties and chemical functionalities by changing the combination of metal centers and organic linkers during the synthesis. This leads to a large diversity of materials with various pore sizes and shapes that can be efficiently used for CO2 separations. Since the number of synthesized MOFs has already reached to several thousand, experimental investigation of each MOF at the lab-scale is not practical. High-throughput computational screening of MOFs is a great opportunity to identify the best materials for CO2 separation and to gain molecular-level insights into the structure-performance relationships. This type of knowledge can be used to design new materials with the desired structural features that can lead to extraordinarily high CO2 selectivities. In this mini-review, we focused on developments in high-throughput molecular simulations of MOFs for CO2 separations. After reviewing the current studies on this topic, we discussed the opportunities and challenges in the field and addressed the potential future developments.

  19. An inorganic carbon transport system responsible for acclimation specific to air levels of CO2 in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Wang, Yingjun; Spalding, Martin H

    2006-06-27

    Many photosynthetic microorganisms acclimate to CO(2) limited environments by induction and operation of CO(2)-concentrating mechanisms (CCMs). Despite their central role in CCM function, inorganic carbon (Ci) transport systems never have been identified in eukaryotic photosynthetic organisms. In the green alga Chlamydomonas reinhardtii, a mutant, pmp1, was described in 1983 with deficiencies in Ci transport, and a Pmp1 protein-associated Ci uptake system has been proposed to be responsible for Ci uptake in low CO(2) (air level)-acclimated cells. However, even though pmp1 represents the only clear genetic link to Ci transport in microalgae and is one of only a very few mutants directly affecting the CCM itself, the identity of Pmp1 has remained unknown. Physiological analyses indicate that C. reinhardtii possesses multiple Ci transport systems responsible for acclimation to different levels of limiting CO(2) and that the Pmp1-associated transport system is required specifically for low (air level) CO(2) acclimation. In the current study, we identified and characterized a pmp1 allelic mutant, air dier 1 (ad1) that, like pmp1, cannot grow in low CO(2) (350 ppm) but can grow either in high CO(2) (5% CO(2)) or in very low CO(2) (<200 ppm). Molecular analyses revealed that the Ad1/Pmp1 protein is encoded by LciB, a gene previously identified as a CO(2)-responsive gene. LciB and three related genes in C. reinhardtii compose a unique gene family that encode four closely related, apparently soluble plastid proteins with no clearly identifiable conserved motifs.

  20. Responses of Four Rice Varieties to Elevated CO2 and Different Salinity Levels

    Directory of Open Access Journals (Sweden)

    Sheidollah Kazemi

    2018-05-01

    Full Text Available Abstract:: This study was carried out in 2014 at Isfahan University of Technology, Iran, to evaluate the responses of four rice varieties (Neda, Deylamani, Shiroudi and Domsorkh to ambient (360 ± 50 μmol/mol and elevated (700 ± 50 μmol/mol air carbon dioxide (CO2 concentrations under four salinity levels (0, 30, 60 and 90 mmol/L NaCl. There was significant variation among rice varieties in response to elevated CO2 concentration under the four salinity levels. Under non-saline condition, elevated CO2 increased the dry weight of Neda, Deylamani and Domsorkh by 8%, 50% and 8%, respectively, but reversely decreased that of Shiroudi by 34%. Increasing CO2 concentration significantly reduced the negative effects of salinity on Shiroudi, but these effects were even increased in Deylamani and Domsorkh under all the salinity levels and in Neda only under 30 and 60 mmol/L NaCl. Significant correlations were established between plant dry weight, SPAD value and leaf area under both CO2 levels. However, this trend was observed only at ambient CO2 concentration in the presence of soluble carbohydrates. The results revealed the genotype and salinity dependence of the effects of CO2 concentrations on the rice traits investigated. Key words: CO2 concentration, genetic diversity, salt tolerance, water soluble carbohydrate

  1. Late Cretaceous climate simulations with different CO2 levels and subarctic gateway configurations: A model-data comparison

    Science.gov (United States)

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

    2017-09-01

    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.

  2. Quantification of fossil fuel CO2 at the building/street level for large US cities

    Science.gov (United States)

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

    2012-12-01

    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

  3. 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.

    2007-01-01

    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, http://www.goldsim.com]. 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

  4. New CO2 Sensor with High Resolution and Fast Response

    Science.gov (United States)

    2001-10-25

    that a few solid substances selectively adsorb CO2. Combined with a Quartz Micro Balance (QMB) [1, 2] or a Surface Acoustic Wave (SAW) device [3...cardiovascular or respiratory tracts should be sterile or desinfected disposables to minimize the risk for the spread of harmful microorganisms. To

  5. CO2 emission inventories for Chinese cities in highly urbanized areas compared with European cities

    International Nuclear Information System (INIS)

    Yu Wei; Pagani, Roberto; Huang Lei

    2012-01-01

    The international literature has paid significant attention to presenting China as the largest emitter of greenhouse gases (GHGs) in the world, despite having much lower per-capita emissions than the global average. In fact, the imbalance of economic development leads to diversity in GHG emissions profiles in different areas of China. This paper employs a common methodology, consistent with the Sustainable Energy Action Plan (SEAP) approved by the Covenant of Mayors (CoM), to estimate CO 2 emissions of four Chinese cities in highly urbanized areas from 2004 to 2010. The results show that the CO 2 emissions of all four cities are still rising and that secondary industries emit the most CO 2 in these cities. By comparing these data with the inventory results of two European cities, this paper further reveals that Chinese cities in highly urbanized areas contribute much higher per-capita emissions than their European competitors. Furthermore, the per-capita CO 2 emissions of the residential sector and private transport in these Chinese cities are growing rapidly, some of them approaching the levels of European cities. According to these findings, several policy suggestions considering regional disparities are provided that aim to reduce the CO 2 emissions of highly urbanized areas in China. - Highlights: ► An exemplary study of GHG emission inventory for Chinese cities. ► Estimate CO 2 emissions of Chinese city in highly urbanized areas from 2004 to 2010. ► The studied Chinese cities contribute higher per-capita emissions than European’s. ► Emissions of residential sector and private transport in China are growing rapidly. ► Several policy suggestions considering regional disparities are provided.

  6. Winter time burst of CO2 from the High Arctic soils of Svalbard

    DEFF Research Database (Denmark)

    Friborg, Thomas; Hansen, Birger; Elberling, Bo

    of relatively few measurements which appear to give small and constant emission rates. Further, most studies of the processes behind winter time emission of CO2 conclude that the flux during this time of year can be linked to the respiratory release of CO2 from soil micro organisms, which is temperature...... the winter at a high arctic location in Svalbard (78°N). Measurements were conducted in the field during the winter season of 2004-2005 and show reliable and continuous measurements of CO2 fluxes down to a level of 0.01 ìmol m-2 s-1 and good correspondence with other types of soil chambers. Our results...... indicate that a substantial part of the annual CO2 emission from the ecosystem occur during the freeze in period, where more CO2 is emitted from the soil over a few weeks than the accumulated flux for the rest of the winter. During the coldest part of the...

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

    Science.gov (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

    2017-10-01

    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.

  8. Carbon Balance at Landscape Level inferred fromTower CO2 Concentration Measurements

    Science.gov (United States)

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

    2003-04-01

    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

  9. Dip in the atmospheric CO2 level during the mid-1960's

    International Nuclear Information System (INIS)

    Bacastow, R.

    1979-01-01

    Removal of the southern oscillation effect from the CO 2 records at Mauna Loa, Hawaii, and the South Pole reveals corresponding decreases following the Agung eruption in 1963. The period of the decreases roughly corresponds to the period of reduced solar transmittance, as measured at Mauna Loa. It is suggested that the decrease in CO 2 level is due to reduced sea surface temperatures, for which there is some direct evidence. The temperature anomaly required to produce the CO 2 level dip is calculated on the basis of several simple models and found to be close to that observed

  10. Carbon assimilation in Eucalyptus urophylla grown under high atmospheric CO2 concentrations: A proteomics perspective.

    Science.gov (United States)

    Santos, Bruna Marques Dos; Balbuena, Tiago Santana

    2017-01-06

    Photosynthetic organisms may be drastically affected by the future climate projections of a considerable increase in CO 2 concentrations. Growth under a high concentration of CO 2 could stimulate carbon assimilation-especially in C3-type plants. We used a proteomics approach to test the hypothesis of an increase in the abundance of the enzymes involved in carbon assimilation in Eucalyptus urophylla plants grown under conditions of high atmospheric CO 2 . Our strategy allowed the profiling of all Calvin-Benson cycle enzymes and associated protein species. Among the 816 isolated proteins, those involved in carbon fixation were found to be the most abundant ones. An increase in the abundance of six key enzymes out of the eleven core enzymes involved in carbon fixation was detected in plants grown at a high CO 2 concentration. Proteome changes were corroborated by the detection of a decrease in the stomatal aperture and in the vascular bundle area in Eucalyptus urophylla plantlets grown in an environment of high atmospheric CO 2 . Our proteomics approach indicates a positive metabolic response regarding carbon fixation in a CO 2 -enriched atmosphere. The slight but significant increase in the abundance of the Calvin enzymes suggests that stomatal closure did not prevent an increase in the carbon assimilation rates. The sample enrichment strategy and data analysis used here enabled the identification of all enzymes and most protein isoforms involved in the Calvin-Benson-Bessham cycle in Eucalyptus urophylla. Upon growth in CO 2 -enriched chambers, Eucalyptus urophylla plantlets responded by reducing the vascular bundle area and stomatal aperture size and by increasing the abundance of six of the eleven core enzymes involved in carbon fixation. Our proteome approach provides an estimate on how a commercially important C3-type plant would respond to an increase in CO 2 concentrations. Additionally, confirmation at the protein level of the predicted genes involved in

  11. A microporous MOF with a polar pore surface exhibiting excellent selective adsorption of CO2 from CO2-N2 and CO2-CH4 gas mixtures with high CO2 loading.

    Science.gov (United States)

    Pal, Arun; Chand, Santanu; Elahi, Syed Meheboob; Das, Madhab C

    2017-11-14

    A microporous MOF {[Zn(SDB)(L) 0.5 ]·S} n (IITKGP-5) with a polar pore surface has been constructed by the combination of a V-shaped -SO 2 functionalized organic linker (H 2 SDB = 4,4'-sulfonyldibenzoic acid) with an N-rich spacer (L = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene), forming a network with sql(2,6L1) topology. IITKGP-5 is characterized by TGA, PXRD and single crystal X-ray diffraction. The framework exhibits lozenge-shaped channels of an approximate size of 4.2 × 5.6 Å 2 along the crystallographic b axis with a potential solvent accessible volume of 26%. The activated IITKGP-5a revealed a CO 2 uptake capacity of 56.4 and 49 cm 3 g -1 at 273 K/1 atm and 295 K/1 atm, respectively. On the contrary, it takes up a much smaller amount of CH 4 (17 cm 3 g -1 at 273 K and 13.6 cm 3 g -1 at 295 K) and N 2 (5.5 cm 3 g -1 at 273 K; 4 cm 3 g -1 at 295 K) under 1 atm pressure exhibiting its potential for a highly selective adsorption of CO 2 from flue gas as well as a landfill gas mixture. Based on the ideal adsorbed solution theory (IAST), a CO 2 /N 2 selectivity of 435.5 and a CO 2 /CH 4 selectivity of 151.6 have been realized at 273 K/100 kPa. The values at 295 K are 147.8 for CO 2 /N 2 and 23.8 for CO 2 /CH 4 gas mixtures under 100 kPa. In addition, this MOF nearly approaches the target values proposed for PSA and TSA processes for practical utility exhibiting its prospect for flue gas separation with a CO 2 loading capacity of 2.04 mmol g -1 .

  12. Light-Triggered CO2 Breathing Foam via Nonsurfactant High Internal Phase Emulsion.

    Science.gov (United States)

    Zhang, Shiming; Wang, Dingguan; Pan, Qianhao; Gui, Qinyuan; Liao, Shenglong; Wang, Yapei

    2017-10-04

    Solid materials for CO 2 capture and storage have attracted enormous attention for gaseous separation, environmental protection, and climate governance. However, their preparation and recovery meet the problems of high energy and financial cost. Herein, a controllable CO 2 capture and storage process is accomplished in an emulsion-templated polymer foam, in which CO 2 is breathed-in under dark and breathed-out under light illumination. Such a process is likely to become a relay of natural CO 2 capture by plants that on the contrary breathe out CO 2 at night. Recyclable CO 2 capture at room temperature and release under light irradiation guarantee its convenient and cost-effective regeneration in industry. Furthermore, CO 2 mixed with CH 4 is successfully separated through this reversible breathing in and out system, which offers great promise for CO 2 enrichment and practical methane purification.

  13. High Arctic Forests During the Middle Eocene Supported by ~400 ppm Atmospheric CO2

    Science.gov (United States)

    Maxbauer, D. P.; Royer, D. L.; LePage, B. A.

    2013-12-01

    Fossils from Paleogene High Arctic deposits provide some of the clearest evidence for greenhouse climates and offer the potential to improve our understanding of Earth system dynamics in a largely ice-free world. One of the most well-known and exquisitely-preserved middle Eocene (47.9-37.8 Myrs ago) polar forest sites, Napartulik, crops out on eastern Axel Heiberg Island (80 °N), Nunavut, Canada. An abundance of data from Napartulik suggest mean annual temperatures of up to 30 °C warmer than today and atmospheric water loads 2× above current levels. Despite this wealth of paleontological and paleoclimatological data, there are currently no direct constraints on atmospheric CO2 levels for Napartulik or any other polar forest site. Here we apply a new plant gas-exchange model to Metasequoia (dawn redwood) leaves to reconstruct atmospheric CO2 from six fossil forests at Napartulik. Individual reconstructions vary between 405-489 ppm with a site mean of 437 ppm (337-564 ppm at 95% confidence). These estimates represent the first direct constraints on CO2 for polar fossil forests and suggest that the temperate conditions present at Napartulik during the middle Eocene were maintained under CO2 concentrations ~1.6× above pre-industrial levels. Our results strongly support the case that long-term climate sensitivity to CO2 in the past was sometimes high, even during largely ice-free periods, highlighting the need to better understand the climate forcing and feedback mechanisms responsible for this amplification.

  14. Relationship between sea level and climate forcing by CO2 on geological timescales.

    Science.gov (United States)

    Foster, Gavin L; Rohling, Eelco J

    2013-01-22

    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.

  15. High-resolution Atmospheric pCO2 Reconstruction across the Paleogene Using Marine and Terrestrial δ13C records

    Science.gov (United States)

    Cui, Y.; Schubert, B.

    2016-02-01

    The early Paleogene (63 to 47 Ma) is considered to have a greenhouse climate1 with proxies suggesting atmospheric CO2 levels (pCO2) approximately 2× pre-industrial levels. However, the proxy based pCO2 reconstructions are limited and do not allow for assessment of changes in pCO2 at million to sub-million year time scales. It has recently been recognized that changes in C3 land plant carbon isotope fractionation can be used as a proxy for pCO2 with quantifiable uncertainty2. Here, we present a high-resolution pCO2 reconstruction (n = 597) across the early Paleogene using published carbon isotope data from both terrestrial organic matter and marine carbonates. The minimum and maximum pCO2 values reconstructed using this method are broad (i.e., 170 +60/-40 ppmv to 2000 +4480/-1060 ppmv) and reflective of the wide range of environments sampled. However, the large number of measurements allows for a robust estimate of average pCO2 during this time interval ( 400 +260/-120 ppmv), and indicates brief (sub-million-year) excursions to very high pCO2 during hyperthermal events (e.g., the PETM). By binning our high-resolution pCO2 data at 1 million year intervals, we can compare our dataset to the other available pCO2 proxies. Our result is broadly consistent with pCO2 levels reconstructed using other proxies, with the exception of paleosol-based pCO2 estimates spanning 53 to 50 Ma. At this timescale, no proxy suggests pCO2 higher than 2000 ppmv, whereas the global surface ocean temperature is considered to be >10 oC warmer than today. Recent climate modeling suggests that low atmospheric pressure during this time period could help reconcile the apparent disconnect between pCO2 and temperature and contribute to the greenhouse climate3. References1. Huber, M., Caballero, R., 2011. Climate of the Past 7, 603-633. 2. Schubert, B.A., Jahren, A.H., 2015. Geology 43, 435-438. 3. Poulsen, C.J., Tabor, C., White, J.D., 2015. Science 348, 1238-1241.

  16. Isolation and determination of cultural characteristics of a new highly CO2 tolerant fresh water microalgae

    International Nuclear Information System (INIS)

    Yue Lihong; Chen Weigong

    2005-01-01

    Fresh water microalgae, which has high CO 2 tolerance, were isolated and its cultural characteristics were investigated. The ZY-1 strain was identified as genus Chlorella. It showed maximum growth at 10% (v/v) CO 2 enriched air flowing condition, and a good growth rate in a broad range of physically controllable conditions, including CO 2 concentration up to 70% (v/v), CO 2 enriched air flow rate, temperature and pH value. The results indicated the feasibility of the ZY-1 strain for fixing CO 2 from stack gases

  17. AltitudeOmics: Resetting of cerebrovascular CO2 reactivity following acclimatization to high altitude

    Directory of Open Access Journals (Sweden)

    Jui-Lin eFan

    2016-01-01

    Full Text Available Previous studies reported enhanced cerebrovascular CO2 reactivity upon ascent to high altitude using linear models. However, there is evidence that this response may be sigmoidal in nature. Moreover, it was speculated that these changes at high altitude are mediated by alterations in acid-base buffering. Accordingly, we reanalyzed previously published data to assess middle cerebral blood flow velocity (MCAv responses to modified rebreathing at sea level (SL, upon ascent (ALT1 and following 16 days of acclimatization (ALT16 to 5,260 m in 21 lowlanders. Using sigmoid curve fitting of the MCAv responses to CO2, we found the amplitude (95% vs. 129%, SL vs. ALT1, 95% confidence intervals (CI [77, 112], [111, 145], respectively, P=0.024 and the slope of the sigmoid response (4.5 vs. 7.5 %/mmHg, SL vs. ALT1, 95% CIs [3.1, 5.9], [6.0, 9.0], respectively, P=0.026 to be enhanced at ALT1, which persisted with acclimatization at ALT16 (amplitude: 177%, 95% CI [139, 215], P<0.001; slope: 10.3 %/mmHg, 95% CI [8.2, 12.5], P=0.003 compared to SL. Meanwhile, the sigmoidal response midpoint was unchanged at ALT1 (SL: 36.5 mmHg; ALT1: 35.4 mmHg, 95% CIs [34.0, 39.0], [33.1, 37.7], respectively, P=0.982, while it was reduced by ~7 mmHg at ALT16 (28.6 mmHg, 95% CI [26.4, 30.8], P=0.001 vs. SL, indicating leftward shift of the cerebrovascular CO2 response to a lower arterial partial pressure of CO2 (PaCO2 following acclimatization to altitude. Sigmoid fitting revealed a leftward shift in the midpoint of the cerebrovascular response curve which could not be observed with linear fitting. These findings demonstrate that there is resetting of the cerebrovascular CO2 reactivity operating point to a lower PaCO2 following acclimatization to high altitude. This cerebrovascular resetting is likely the result of an altered acid-base buffer status resulting from prolonged exposure to the severe hypocapnia associated with ventilatory acclimatization to high altitude.

  18. 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

    2015-01-01

    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

  19. The fate of the Greenland Ice Sheet in a geoengineered, high CO2 world

    International Nuclear Information System (INIS)

    Irvine, Peter J; Lunt, Daniel J; Stone, Emma J; Ridgwell, Andy

    2009-01-01

    Solar radiation management (SRM) geoengineering has been proposed as one means of helping avoid the occurrence of dangerous climate change and undesirable state transitions ('tipping points') in the Earth system. The irreversible melting of the Greenland Ice Sheet is a case in point-a state transition that could occur as a result of CO 2 -driven elevated global temperatures, and one leading to potentially catastrophic sea-level rise. SRM schemes such as the creation of a 'sunshade' or injection of sulfate aerosols into the stratosphere could reduce incoming solar radiation, and in theory balance, in a global mean, the greenhouse warming resulting from elevated concentrations of CO 2 in the atmosphere. Previous work has highlighted that a geoengineered world would have: warming towards the poles, cooling in the tropics, and a reduction in the global hydrological cycle, which may have important implications for the Greenland Ice Sheet. Using a fully coupled global climate model in conjunction with an ice sheet model, we assess the consequences for the mass balance of the Greenland Ice Sheet of the reorganization of climate patterns by the combination of high CO 2 and geoengineering. We find that Greenland surface temperature and precipitation anomalies, compared to the pre-industrial situation, decrease almost linearly with increasing levels of SRM geoengineering, but that these combine to create a highly non-linear response of the ice sheet. The substantial melting of the Greenland Ice Sheet predicted for four times pre-industrial CO 2 levels is prevented in our model with only a partial application of SRM, and hence without having to fully restore the global average temperature back to pre-industrial levels. This suggests that the degree of SRM geoengineering required to mitigate the worst impacts of greenhouse warming, such as sea-level rise, need not be as extensive as generally assumed.

  20. Water stress, CO2 and photoperiod influence hormone levels in wheat

    Science.gov (United States)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  1. Armazenamento refrigerado de morango submetido a altas concentrações de CO2 Cold storage of strawberries under high CO2 concentrations

    Directory of Open Access Journals (Sweden)

    Luis C Cunha Junior

    2012-12-01

    strawberries. However, fruits and vegetables are not currently handled under cold chain in Brazil and, when it happens, it used to be at 10 to 15ºC. The goal of this work was to evaluate the quality and the shelf life of 'Oso Grande' strawberry at 10ºC associated to high carbon dioxide concentrations. Strawberries were randomized, chilled and stored at 10ºC in hermetic mini-chambers to apply the CO2 concentrations (0.03, 10, 20, 40 and 80% plus 20% O2. Strawberries were analyzed every two days while they were proper to consumption. The shelf life for strawberries at 20 and 40% CO2 was 8 days, while those at 0.03% CO2 lasted only two days. Strawberries at 80% CO2 maintained good appearance for 6 days, but they were considered unsuitable for consumption due to high levels of acetaldehyde (40.92 µg g-1 and ethanol (1,053 µg g-1 that gave evidence of fermentation process. The weight loss was less than 2% showing how efficient was the method used to control the relative humidity during the storage. Strawberries at 0.03 and 80% CO2 levels showed higher firmness loss. Those fruits lost 40% of the initial firmness. Strawberries at 20 and 40% CO2 lost only 28% of initial firmness. Despite of the statistical effect of the treatments in the external color it was not visually perceptible. Strawberries stored at 10ºC and 40% CO2 plus 20% O2 kept the marketable quality during 8 days.

  2. Analysis of Pacific oyster larval proteome and its response to high-CO2

    KAUST Repository

    Dineshram, R.

    2012-10-01

    Most calcifying organisms show depressed metabolic, growth and calcification rates as symptoms to high-CO2 due to ocean acidification (OA) process. Analysis of the global expression pattern of proteins (proteome analysis) represents a powerful tool to examine these physiological symptoms at molecular level, but its applications are inadequate. To address this knowledge gap, 2-DE coupled with mass spectrophotometer was used to compare the global protein expression pattern of oyster larvae exposed to ambient and to high-CO2. Exposure to OA resulted in marked reduction of global protein expression with a decrease or loss of 71 proteins (18% of the expressed proteins in control), indicating a wide-spread depression of metabolic genes expression in larvae reared under OA. This is, to our knowledge, the first proteome analysis that provides insights into the link between physiological suppression and protein down-regulation under OA in oyster larvae. © 2012 Elsevier Ltd.

  3. Impact of global warming and rising CO2 levels on coral reef fishes: what hope for the future?

    Science.gov (United States)

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

    2012-11-15

    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

  4. Δ14C level of annual plants and fossil fuel derived CO2 distribution across different regions of China

    International Nuclear Information System (INIS)

    Xi, X.T.; Ding, X.F.; Fu, D.P.; Zhou, L.P.; Liu, K.X.

    2013-01-01

    The 14 C level in annual plants is a sensitive tracer for monitoring fossil fuel derived CO 2 in the atmosphere. Corn leave samples were selected from different regions of China, including high mountains in the Tibetan Plateau, grassland in Inner Mongolia, and inland and coastal cities during the summer of 2010. The 14 C/ 12 C ratio of the samples was measured with the NEC compact AMS system at the Institute of Heavy Ion Physics, Peking University. The fossil fuel derived CO 2 was estimated by comparing the measured Δ 14 C values of corn leave samples to background atmospheric Δ 14 C level. The influences of topography, meteorological conditions and carbon cycling processes on the fossil fuel derived CO 2 concentration are considered when interpreting the data. Our results show a clear association of the low Δ 14 C values with regions where human activities are intensive.

  5. Highly integrated CO2 capture and conversion: Direct synthesis of cyclic carbonates from industrial flue gas

    KAUST Repository

    Barthel, Alexander; Saih, Youssef; Gimenez, Michel; Pelletier, Jeremie; Kü hn, Fritz Elmar; D´ Elia, Valerio; Basset, Jean-Marie

    2016-01-01

    Robust and selective catalytic systems based on early transition metal halides (Y, Sc, Zr) and organic nucleophiles were found able to quantitatively capture CO2 from diluted streams via formation of hemicarbonate species and to convert it to cyclic organic carbonates under ambient conditions. This observation was exploited in the direct and selective chemical fixation of flue gas CO2 collected from an industrial exhaust, affording high degrees of CO2 capture and conversion.

  6. Highly integrated CO2 capture and conversion: Direct synthesis of cyclic carbonates from industrial flue gas

    KAUST Repository

    Barthel, Alexander

    2016-02-08

    Robust and selective catalytic systems based on early transition metal halides (Y, Sc, Zr) and organic nucleophiles were found able to quantitatively capture CO2 from diluted streams via formation of hemicarbonate species and to convert it to cyclic organic carbonates under ambient conditions. This observation was exploited in the direct and selective chemical fixation of flue gas CO2 collected from an industrial exhaust, affording high degrees of CO2 capture and conversion.

  7. Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2: an experiment with plant populations from naturally high CO2 areas.

    Science.gov (United States)

    van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

    2016-06-01

    The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant-plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may benefit more from [CO2] elevation than others. The relative contribution of plastic (within the plant's lifetime) and genotypic (over several generations) responses to elevated [CO2] on plant performance was investigated and how these patterns are modified by plant-plant interactions was analysed. Plantago asiatica seeds originating from natural CO2 springs and from ambient [CO2] sites were grown in mono stands of each one of the two origins as well as mixtures of both origins. In total, 1944 plants were grown in [CO2]-controlled walk-in climate rooms, under a [CO2] of 270, 450 and 750 ppm. A model was used for upscaling from leaf to whole-plant photosynthesis and for quantifying the influence of plastic and genotypic responses. It was shown that changes in canopy photosynthesis, specific leaf area (SLA) and stomatal conductance in response to changes in growth [CO2] were mainly determined by plastic and not by genotypic responses. We further found that plants originating from high [CO2] habitats performed better in terms of whole-plant photosynthesis, biomass and leaf area, than those from ambient [CO2] habitats at elevated [CO2] only when both genotypes competed. Similarly, plants from ambient [CO2] habitats performed better at low [CO2], also only when both genotypes competed. No difference in performance was found in mono stands. The results indicate that natural selection under increasing [CO2] will be mainly driven by competitive interactions. This supports the notion that plant-plant interactions have an important influence on future vegetation functioning and species distribution. Furthermore, plant performance was mainly driven by plastic and not by genotypic responses to changes in

  8. Plant–plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2: an experiment with plant populations from naturally high CO2 areas

    Science.gov (United States)

    van Loon, Marloes P.; Rietkerk, Max; Dekker, Stefan C.; Hikosaka, Kouki; Ueda, Miki U.; Anten, Niels P. R.

    2016-01-01

    Background and Aims The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant–plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may benefit more from [CO2] elevation than others. The relative contribution of plastic (within the plant’s lifetime) and genotypic (over several generations) responses to elevated [CO2] on plant performance was investigated and how these patterns are modified by plant–plant interactions was analysed. Methods Plantago asiatica seeds originating from natural CO2 springs and from ambient [CO2] sites were grown in mono stands of each one of the two origins as well as mixtures of both origins. In total, 1944 plants were grown in [CO2]-controlled walk-in climate rooms, under a [CO2] of 270, 450 and 750 ppm. A model was used for upscaling from leaf to whole-plant photosynthesis and for quantifying the influence of plastic and genotypic responses. Key Results It was shown that changes in canopy photosynthesis, specific leaf area (SLA) and stomatal conductance in response to changes in growth [CO2] were mainly determined by plastic and not by genotypic responses. We further found that plants originating from high [CO2] habitats performed better in terms of whole-plant photosynthesis, biomass and leaf area, than those from ambient [CO2] habitats at elevated [CO2] only when both genotypes competed. Similarly, plants from ambient [CO2] habitats performed better at low [CO2], also only when both genotypes competed. No difference in performance was found in mono stands. Conclusion The results indicate that natural selection under increasing [CO2] will be mainly driven by competitive interactions. This supports the notion that plant–plant interactions have an important influence on future vegetation functioning and species distribution. Furthermore, plant performance was mainly

  9. High Materials Performance in Supercritical CO2 in Comparison with Atmospheric Pressure CO2 and Supercritical Steam

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Tylczak, Joseph [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Carney, Casey [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Dogan, Omer N. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2017-02-26

    This presentation covers environments (including advanced ultra-supercritical (A-USC) steam boiler/turbine and sCO2 indirect power cycle), effects of pressure, exposure tests, oxidation results, and mechanical behavior after exposure.

  10. A DC excited waveguide multibeam CO2 laser using high frequency ...

    Indian Academy of Sciences (India)

    High power industrial multibeam CO2 lasers consist of a large number of closely packed ... by producing pre-ionization using an auxiliary high frequency pulsed ... of few kilowatts output power, multibeam technique is used [2]. .... gas mixture of CO2, N2 and He enters in each discharge tube individually from .... Commercial.

  11. Intertidal oysters reach their physiological limit in a future high-CO2 world.

    Science.gov (United States)

    Scanes, Elliot; Parker, Laura M; O'Connor, Wayne A; Stapp, Laura S; Ross, Pauline M

    2017-03-01

    Sessile marine molluscs living in the intertidal zone experience periods of internal acidosis when exposed to air (emersion) during low tide. Relative to other marine organisms, molluscs have been identified as vulnerable to future ocean acidification; however, paradoxically it has also been shown that molluscs exposed to high CO 2 environments are more resilient compared with those molluscs naive to CO 2 exposure. Two competing hypotheses were tested using a novel experimental design incorporating tidal simulations to predict the future intertidal limit of oysters in a high-CO 2 world; either high-shore oysters will be more tolerant of elevated P CO 2 because of their regular acidosis, or elevated P CO 2  will cause high-shore oysters to reach their limit. Sydney rock oysters, Saccostrea glomerata , were collected from the high-intertidal and subtidal areas of the shore and exposed in an orthogonal design to either an intertidal or a subtidal treatment at ambient or elevated P CO 2 , and physiological variables were measured. The combined treatment of tidal emersion and elevated P CO 2  interacted synergistically to reduce the haemolymph pH (pH e ) of oysters, and increase the P CO 2  in the haemolymph ( P e,CO 2 ) and standard metabolic rate. Oysters in the intertidal treatment also had lower condition and growth. Oysters showed a high degree of plasticity, and little evidence was found that intertidal oysters were more resilient than subtidal oysters. It is concluded that in a high-CO 2 world the upper vertical limit of oyster distribution on the shore may be reduced. These results suggest that previous studies on intertidal organisms that lacked tidal simulations may have underestimated the effects of elevated P CO 2 . © 2017. Published by The Company of Biologists Ltd.

  12. Enhanced photosynthetic efficiency in trees world-wide by rising atmospheric CO2 levels

    Science.gov (United States)

    Ehlers, Ina; Wieloch, Thomas; Groenendijk, Peter; Vlam, Mart; van der Sleen, Peter; Zuidema, Pieter A.; Robertson, Iain; Schleucher, Jürgen

    2014-05-01

    The atmospheric CO2 concentration is increasing rapidly due to anthropogenic emissions but the effect on the Earth's biosphere is poorly understood. The ability of the biosphere to fix CO2 through photosynthesis will determine future atmospheric CO2 concentrations as well as future productivity of crops and forests. Manipulative CO2 enrichment experiments (e.g. FACE) are limited to (i) short time spans, (ii) few locations and (iii) large step increases in [CO2]. Here, we apply new stable isotope methodology to tree-ring archives, to study the effect of increasing CO2 concentrations retrospectively during the past centuries. We cover the whole [CO2] increase since industrialization, and sample trees with global distribution. Instead of isotope ratios of whole molecules, we use intramolecular isotope distributions, a new tool for tree-ring analysis with decisive advantages. In experiments on annual plants, we have found that the intramolecular distribution of deuterium (equivalent to ratios of isotopomer abundances) in photosynthetic glucose depends on growth [CO2] and reflects the metabolic flux ratio of photosynthesis to photorespiration. By applying this isotopomer methodology to trees from Oak Ridge FACE experiment, we show that this CO2 response is present in trees on the leaf level. This CO2 dependence constitutes a physiological signal, which is transferred to the wood of the tree rings. In trees from 13 locations on all continents the isotopomer ratio of tree-ring cellulose is correlated to atmospheric [CO2] during the past 200 years. The shift of the isotopomer ratio is universal for all 12 species analyzed, including both broad-leafed trees and conifers. Because the trees originate from sites with widely differing D/H ratios of precipitation, the generality of the response demonstrates that the signal is independent of the source isotope ratio, because it is encoded in an isotopomer abundance ratio. This decoupling of climate signals and physiological

  13. Laser plant "Iguana" for transmyocardial revascularization based on kW-level waveguide CO2 laser

    Science.gov (United States)

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

    2001-05-01

    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.

  14. Can Increased CO2 Levels Trigger a Runaway Greenhouse on the Earth?

    Science.gov (United States)

    Ramirez, R.

    2014-04-01

    Recent one-dimensional (globally averaged) climate model calculations suggest that increased atmospheric CO2 could conceivably trigger a runaway greenhouse if CO2 concentrations were approximately 100 times higher than today. The new prediction runs contrary to previous calculations, which indicated that CO2 increases could not trigger a runaway, even at Venus-like CO2 concentrations. Goldblatt et al. argue that this different behavior is a consequence of updated absorption coefficients for H2O that make a runaway more likely. Here, we use a 1-D cloud-free climate model with similar, up-to-date absorption coefficients, but with a self-consistent methodology, to demonstrate that CO2 increases cannot induce a runaway greenhouse on the modern Earth. However, these initial calculations do not include cloud feedback, which may be positive at higher temperatures, destabilizing Earth's climate. We then show new calculations demonstrating that cirrus clouds cannot trigger a runaway, even in the complete absence of low clouds. Thus, the habitability of an Earth-like planet at Earth's distance appears to be ensured, irrespective of the sign of cloud feedback. Our results are of importance to Earth-like planets that receive similar insolation levels as does the Earth and to the ongoing question about cloud response at higher temperatures.

  15. Elevated CO2 stimulates marsh elevation gain, counterbalancing sea-level rise.

    Science.gov (United States)

    Langley, J Adam; McKee, Karen L; Cahoon, Donald R; Cherry, Julia A; Megonigal, J Patrick

    2009-04-14

    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 CO(2) 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 [CO(2)] stimulates biogenic mechanisms of elevation gain in a brackish marsh. Elevated CO(2) (ambient + 340 ppm) accelerated soil elevation gain by 3.9 mm yr(-1) in this 2-year field study, an effect mediated by stimulation of below-ground plant productivity. Further, a companion greenhouse experiment revealed that the CO(2) 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, CO(2), may paradoxically aid some coastal wetlands in counterbalancing rising seas.

  16. Elevated CO2 stimulates marsh elevation gain, counterbalancing sea-level rise

    Science.gov (United States)

    Langley, J. Adam; McKee, Karen L.; Cahoon, Donald R.; Cherry, Julia A.; Megonigal, J. Patrick

    2009-01-01

    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−1 in 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. PMID:19325121

  17. Infrared radiation and inversion population of CO2 laser levels in Venusian and Martian atmospheres

    Science.gov (United States)

    Gordiyets, B. F.; Panchenko, V. Y.

    1983-01-01

    Formation mechanisms of nonequilibrium 10 micron CO2 molecule radiation and the possible existence of a natural laser effect in the upper atmospheres of Venus and Mars are theoretically studied. An analysis is made of the excitation process of CO2 molecule vibrational-band levels (with natural isotropic content) induced by direct solar radiation in bands 10.6, 9.4, 4.3, 2.7 and 2.0 microns. The model of partial vibrational-band temperatures was used in the case. The problem of IR radiation transfer in vibrational-rotational bands was solved in the radiation escape approximation.

  18. Exceptionally High Efficient Co-Co2P@N, P-Codoped Carbon Hybrid Catalyst for Visible Light-Driven CO2-to-CO Conversion.

    Science.gov (United States)

    Fu, Wen Gan

    2018-05-02

    Artificial photosynthesis has attracted wide attention, particularly the development of efficient solar light-driven methods to reduce CO2 to form energy-rich carbon-based products. Because CO2 reduction is an uphill process with a large energy barrier, suitable catalysts are necessary to achieve this transformation. In addition, CO2 adsorption on a catalyst and proton transfer to CO2 are two important factors for the conversion reaction,and catalysts with high surface area and more active sites are required to improve the efficiency of CO2 reduction. Here, we report a visible light-driven system for CO2-to-CO conversion that consists of a heterogeneous hybrid catalyst of Co and Co2P nanoparticles embedded in carbon nanolayers codoped with N and P (Co-Co2P@NPC) and a homogeneous Ru(II)-based complex photosensitizer. The average generation rate of CO of the system was up to 35,000 μmol h-1 g-1 with selectivity of 79.1% in 3 h. Linear CO production at an exceptionally high rate of 63,000 μmol h-1 g-1 was observed in the first hour of reaction. Inspired by this highly active catalyst, we also synthesized Co@NC and Co2P@NPC materials and explored their structure, morphology, and catalytic properties for CO2 photoreduction. The results showed that the nanoparticle size, partially adsorbed H2O molecules on the catalyst surface, and the hybrid nature of the systems influenced their photocatalytic CO2 reduction performance. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. The decrease of CO2 emission intensity is decarbonization at national and global levels

    International Nuclear Information System (INIS)

    Sun, J.W.

    2005-01-01

    This viewpoint proposes the definition: 'Decarbonization refers to a decrease of CO 2 emission intensity in a trend'. This viewpoint then argues that an analysis of decarbonization at national and global levels based on that definition would lead to the correct calculation of decarbonization

  20. 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.

  1. Species Interactions Drive Fish Biodiversity Loss in a High-CO2 World.

    Science.gov (United States)

    Nagelkerken, Ivan; Goldenberg, Silvan U; Ferreira, Camilo M; Russell, Bayden D; Connell, Sean D

    2017-07-24

    Accelerating climate change is eroding the functioning and stability of ecosystems by weakening the interactions among species that stabilize biological communities against change [1]. A key challenge to forecasting the future of ecosystems centers on how to extrapolate results from short-term, single-species studies to community-level responses that are mediated by key mechanisms such as competition, resource availability (bottom-up control), and predation (top-down control) [2]. We used CO 2 vents as potential analogs of ocean acidification combined with in situ experiments to test current predictions of fish biodiversity loss and community change due to elevated CO 2 [3] and to elucidate the potential mechanisms that drive such change. We show that high risk-taking behavior and competitive strength, combined with resource enrichment and collapse of predator populations, fostered already common species, enabling them to double their populations under acidified conditions. However, the release of these competitive dominants from predator control led to suppression of less common and subordinate competitors that did not benefit from resource enrichment and reduced predation. As a result, local biodiversity was lost and novel fish community compositions were created under elevated CO 2 . Our study identifies the species interactions most affected by ocean acidification, revealing potential sources of natural selection. We also reveal how diminished predator abundances can have cascading effects on local species diversity, mediated by complex species interactions. Reduced overfishing of predators could therefore act as a key action to stall diversity loss and ecosystem change in a high-CO 2 world. VIDEO ABSTRACT. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Projected near-future levels of temperature and pCO2 reduce coral fertilization success.

    Directory of Open Access Journals (Sweden)

    Rebecca Albright

    Full Text Available Increases in atmospheric carbon dioxide (pCO2 are projected to contribute to a 1.1-6.4°C rise in global average surface temperatures and a 0.14-0.35 reduction in the average pH of the global surface ocean by 2100. If realized, these changes are expected to have negative consequences for reef-building corals including increased frequency and severity of coral bleaching and reduced rates of calcification and reef accretion. Much less is known regarding the independent and combined effects of temperature and pCO2 on critical early life history processes such as fertilization. Here we show that increases in temperature (+3°C and pCO2 (+400 µatm projected for this century negatively impact fertilization success of a common Indo-Pacific coral species, Acropora tenuis. While maximum fertilization did not differ among treatments, the sperm concentration required to obtain 50% of maximum fertilization increased 6- to 8- fold with the addition of a single factor (temperature or CO2 and nearly 50- fold when both factors interact. Our results indicate that near-future changes in temperature and pCO2 narrow the range of sperm concentrations that are capable of yielding high fertilization success in A. tenuis. Increased sperm limitation, in conjunction with adult population decline, may have severe consequences for coral reproductive success. Impaired sexual reproduction will further challenge corals by inhibiting population recovery and adaptation potential.

  3. Direct Measurements of Leaf Level CH4 and CO2 Exchange in a Boreal Forest

    Science.gov (United States)

    Crill, P.; Lindroth, A.; Vestin, P.; Båth, A.

    2008-12-01

    Reports of aerobic CH4 sources from leaves and litter of a variety of forests and plant functional types have added a potential mystery to our understanding of CH4 dynamics especially if these sources contribute enough to have a significant impact on the global budget. We have made direct measurements of leaf level CH4 and CO2 exchange using a quartz branch cuvette in a boreal forest in Norunda, Sweden since August of this year. The cuvette was temperature controlled and was designed to close for 5 minutes every 30 minutes. Air was circulated to a Los Gatos CH4/CO2 infrared absorption laser spectrometer. Air and cuvette temperatures, PAR and UV radiation (Kipp and Zonen, CUV4; spectral range 300-380 nm) were measured at the branch chamber. The study was made in the Norunda 100 years old stand consisting of a mixture of Scots pine (Pinus sylvestris L.) , Birch (Betula sp.) and Norway spruce (Picea abies (L.) Karst.). The cuvette was moved between trees at roughly 5 day intervals. A null empty cuvette period was included in the rotation. The initial data show the expected CO2 uptake correlated with incident PAR and low rates of emission at night. However, there was no clear pattern of emissions detectable in the CH4. We estimate that we should be able to resolve a change of 0.5 ppbv CH4 min- 1 with our analytical setup. Both the daytime (1000-1600) and nighttime (2200-0400) averages were less than our detection. Even on very sunny days with high PAR and UV flux values, no consistent pattern was detectable. The lack of a distinct signal may be due to the fact that the past month has been very rainy, it is late in the growth season at these latitudes and sun angles are increasing quickly. The trees were at the northern edge of a clearing and we were also measuring mid height (2-3 m) leaves and branches of young trees. The branch cuvette design can also be optimized to improve its sensitivity.

  4. Tidal marsh plant responses to elevated CO2 , nitrogen fertilization, and sea level rise.

    Science.gov (United States)

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

    2013-05-01

    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.

  5. High-resolution transmission measurements of CO2 at high temperatures for industrial applications

    DEFF Research Database (Denmark)

    Evseev, Vadim; Fateev, Alexander; Clausen, Sønnik

    2012-01-01

    . The spectra have been recorded in a high-temperature flow gas cell and using a Fourier transform infrared (FTIR) spectrometer at a nominal resolution of 0.125 cm-1. The volume fractions of CO2 in the measurements were 1,10 and 100%. The measurements have been validated by comparison with medium...

  6. High CO2 Primes Plant Biotic Stress Defences through Redox-Linked Pathways.

    Science.gov (United States)

    Mhamdi, Amna; Noctor, Graham

    2016-10-01

    Industrial activities have caused tropospheric CO 2 concentrations to increase over the last two centuries, a trend that is predicted to continue for at least the next several decades. Here, we report that growth of plants in a CO 2 -enriched environment activates responses that are central to defense against pathogenic attack. Salicylic acid accumulation was triggered by high-growth CO 2 in Arabidopsis (Arabidopsis thaliana) and other plants such as bean (Phaseolus vulgaris). A detailed analysis in Arabidopsis revealed that elevated CO 2 primes multiple defense pathways, leading to increased resistance to bacterial and fungal challenge. Analysis of gene-specific mutants provided no evidence that activation of plant defense pathways by high CO 2 was caused by stomatal closure. Rather, the activation is partly linked to metabolic effects involving redox signaling. In support of this, genetic modification of redox components (glutathione contents and NADPH-generating enzymes) prevents full priming of the salicylic acid pathway and associated resistance by high CO 2 The data point to a particularly influential role for the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, a cytosolic enzyme whose role in plants remains unclear. Our observations add new information on relationships between high CO 2 and oxidative signaling and provide novel insight into plant stress responses in conditions of increased CO 2 . © 2016 American Society of Plant Biologists. All Rights Reserved.

  7. Silicate minerals for CO2 scavenging from biogas in Autogenerative High Pressure Digestion

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Ferrer, I.; Weijma, J.; Lier, van J.B.

    2013-01-01

    Autogenerative High Pressure Digestion (AHPD) is a novel concept that integrates gas upgrading with anaerobic digestion by selective dissolution of CO2 at elevated biogas pressure. However, accumulation of CO2 and fatty acids after anaerobic digestion of glucose resulted in pH 3–5, which is

  8. High CO2 Primes Plant Biotic Stress Defences through Redox-Linked Pathways1[OPEN

    Science.gov (United States)

    2016-01-01

    Industrial activities have caused tropospheric CO2 concentrations to increase over the last two centuries, a trend that is predicted to continue for at least the next several decades. Here, we report that growth of plants in a CO2-enriched environment activates responses that are central to defense against pathogenic attack. Salicylic acid accumulation was triggered by high-growth CO2 in Arabidopsis (Arabidopsis thaliana) and other plants such as bean (Phaseolus vulgaris). A detailed analysis in Arabidopsis revealed that elevated CO2 primes multiple defense pathways, leading to increased resistance to bacterial and fungal challenge. Analysis of gene-specific mutants provided no evidence that activation of plant defense pathways by high CO2 was caused by stomatal closure. Rather, the activation is partly linked to metabolic effects involving redox signaling. In support of this, genetic modification of redox components (glutathione contents and NADPH-generating enzymes) prevents full priming of the salicylic acid pathway and associated resistance by high CO2. The data point to a particularly influential role for the nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase, a cytosolic enzyme whose role in plants remains unclear. Our observations add new information on relationships between high CO2 and oxidative signaling and provide novel insight into plant stress responses in conditions of increased CO2. PMID:27578552

  9. Effects of CO 2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification

    KAUST Repository

    Omole, Imona C.

    2010-05-19

    A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO2 partial pressures. The cross-linked membrane material shows high intrinsic separation performance for CO2 and CH4 (selectivity ∼49, CO2 permeability ∼161 barrer, with a feed at 65 psia, 35 °C, and 10% CO2). Cross-linked asymmetric hollow-fiber membranes made from the material show good resistance to CO2-induced plasticization. Carbon dioxide partial pressures as high as ∼400 psia were employed, and the membrane was shown to be promisingly stable under these aggressive conditions. The performance of the membrane was also analyzed using the dual-mode sorption/transport model. © 2010 American Chemical Society.

  10. Design of an Optical System for High Power CO2 Laser Cutting

    DEFF Research Database (Denmark)

    de Lange, D.F.; Meijer, J.; Nielsen, Jakob Skov

    2003-01-01

    The results of a design study for the optical system for cutting with high power CO2 lasers (6 kW and up) will be presented. As transparent materials cannot be used for these power levels, mirrors have been applied. A coaxial cutting gas supply has been designed with a laser beam entrance into th...... independent of the entering beam angle or position. manufacturing tolerances have been compensated in a one time adjustment during the assembly of the optical system. Preliminary cutting results in 13 mm thick steel in a shipyard application show a signinficant improvement in the cutting performance....

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

    Science.gov (United States)

    Liu, Chunxiang; Zou, Dinghui

    2015-03-01

    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.

  12. CO2 deficit in temperate forest soils receiving high atmospheric N-deposition.

    Science.gov (United States)

    Fleischer, Siegfried

    2003-02-01

    Evidence is provided for an internal CO2 sink in forest soils, that may have a potential impact on the global CO2-budget. Lowered CO2 fraction in the soil atmosphere, and thus lowered CO2 release to the aboveground atmosphere, is indicated in high N-deposition areas. Also at forest edges, especially of spruce forest, where additional N-deposition has occurred, the soil CO2 is lowered, and the gradient increases into the closed forest. Over the last three decades the capacity of the forest soil to maintain the internal sink process has been limited to a cumulative supply of approximately 1000 and 1500 kg N ha(-1). Beyond this limit the internal soil CO2 sink becomes an additional CO2 source, together with nitrogen leaching. This stage of "nitrogen saturation" is still uncommon in closed forests in southern Scandinavia, however, it occurs in exposed forest edges which receive high atmospheric N-deposition. The soil CO2 gradient, which originally increases from the edge towards the closed forest, becomes reversed.

  13. High temperature CO2 capture of hydroxyapatite extracted from tilapia scales

    Directory of Open Access Journals (Sweden)

    Oscar H. Ojeda-Niño

    2017-11-01

    Full Text Available Hydroxyapatite (HAp was obtained from tilapia scales by two extraction methods: direct calcination and acid-base treatment. The physicochemical characteristics of the obtained HAps were evaluated by thermogravimetric analysis, X-ray fluorescence, X-ray diffraction, scanning electron microscopy, surface area, infrared spectroscopy, and basicity measurement at 298 K by CO2-pulse titration. Furthermore, the CO2 capture capacity of the solids at high temperature was also determined. Both methods showed the presence of a HAp phase although significant differences in the properties of the solids were found. The HAp obtained by direct calcination exhibited a lower crystallinity and a greater surface area and basicity than the HAp obtained by the acid-base treatment. These features were correlated with the solid’s CO2 capture capacity. In this work, CO2 capture capacity values for HAp yielded by calcination ranged from 2.5 to 3.2 mg CO2 /g captured at 973 K, and for the acid-base treatment-derived HAp, CO2 capture capacity values between 1.2 to 2.5 mg CO2 /g were recorded. These results reveal the potential of HAps extracted from tilapia scales as solids with high CO2 capture capacity, thermal stability, and capture/release cycles reversibility.

  14. Application Of CO2 Lasers To High Speed Blanking

    Science.gov (United States)

    Grenier, L. E.

    1986-11-01

    While laser cutting of sheetmetal has attained wide acceptance in the automotive industry for the purposes of prototyping and very limited preproduction work, the production rates possible with currently available systems have precluded the use of this technique in a production environment. The device design to be described embodies a high speed X-Y positioner carrying a cutting head with limited Z-axis capability. This approach confers two main benefits, first, production rate is limited only by laser power, since the positioner technology selected will permit movement at rates up to 1.5 m/s (60 in/s), second, the use of a high speed non-contact surface follower to control the Z-axis movement reduces the need to clamp the workpiece rigidly to a precision reference surface. The realized reduction of the clamping requirement permits some latitude in the feed methods that can be employed, allowing the use of coil or sheet feeding as appropriate. The author will provide estimated production rates for the proposed design and demonstrate that a suitable choice of laser source and material feed will permit the production of parts at a rate and cost comparable to conventional blanking with the advantage of much greater flexibility and reduced retooling time.

  15. CO2 laser cutting of advanced high strength steels (AHSS)

    International Nuclear Information System (INIS)

    Lamikiz, A.; Lacalle, L.N. Lopez de; Sanchez, J.A.; Pozo, D. del; Etayo, J.M.; Lopez, J.M.

    2005-01-01

    This article demonstrates the optimum working areas and cutting conditions for the laser cutting of a series of advanced high strength steels (AHSS). The parameters that most influence the cutting of sheet metal have been studied and the results have been divided into two large groups with thickness of more and less than 1 mm. The influence of the material and, more important, the effect of coating have been taken into account. The results, have demonstrate very different behaviours between the thinnest and thickest sheets, whilst the variation of the cutting parameters due to the influence of the material is less relevant. The optimum cutting areas and the quality of the cut evaluated with different criteria are presented. Finally, the best position for the laser beam has been observed to be underneath the sheet

  16. Dual Phase Membrane for High Temperature CO2 Separation

    Energy Technology Data Exchange (ETDEWEB)

    Jerry Lin

    2007-06-30

    This project aimed at synthesis of a new inorganic dual-phase carbonate membrane for high temperature CO{sub 2} separation. Metal-carbonate dual-phase membranes were prepared by the direct infiltration method and the synthesis conditions were optimized. Permeation tests for CO{sub 2} and N{sub 2} from 450-750 C showed very low permeances of those two gases through the dual-phase membrane, which was expected due to the lack of ionization of those two particular gases. Permeance of the CO{sub 2} and O{sub 2} mixture was much higher, indicating that the gases do form an ionic species, CO{sub 3}{sup 2-}, enhancing transport through the membrane. However, at temperatures in excess of 650 C, the permeance of CO{sub 3}{sup 2-} decreased rapidly, while predictions showed that permeance should have continued to increase with temperature. XRD data obtained from used membrane indicated that lithium iron oxides formed on the support surface. This lithium iron oxide layer has a very low conductivity, which drastically reduces the flow of electrons to the CO{sub 2}/O{sub 2} gas mixture; thus limiting the formation of the ionic species required for transport through the membrane. These results indicated that the use of stainless steel supports in a high temperature oxidative environment can lead to decreased performance of the membranes. This revelation created the need for an oxidation resistant support, which could be gained by the use of a ceramic-type membrane. Work was extended to synthesize a new inorganic dual-phase carbonate membrane for high temperature CO{sub 2} separation. Helium permeance of the support before and after infiltration of molten carbonate are on the order of 10{sup -6} and 10{sup -10} moles/m{sup 2} {center_dot} Pa {center_dot} s respectively, indicating that the molten carbonate is able to sufficiently infiltrate the membrane. It was found that La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (LSCF) was a suitable candidate for the support

  17. Adaptive metal mirror for high-power CO2 lasers

    Science.gov (United States)

    Jarosch, Uwe-Klaus

    1996-08-01

    Spherical mirrors with a variable radius of curvature are used inside laser resonators as well as in the beam path between the laser and the workpiece. Commercially-available systems use piezoelectric actuators, or the pressure of the coolant, to deform the mirror surface. In both cases, the actuator and the cooling system influence each other. This interaction is avoided through the integration of the cooling system with the flexible mirror membrane. A multi- channel design leads to an optimized cooling effect, which is necessary for high power applications. The contour of the variable metal mirror depends on the mounting between the membrane and the mirror body and on the distribution of forces. Four cases of deformation can be distinguished for a circular elastic membrane. The realization of an adaptive metal mirror requires a technical compromise to be made. A mechanical construction is presented which combines an elastic hinge with the inlet and outlet of the coolant. For the deformation of the mirror membranes two actuators with different character of deformation are used. The superposition of the two deformations results in smaller deviations from the spherical surface shape than can be achieved using a single actuator. DC proportional magnets have been introduced as cheap and rigid actuators. The use of this adaptive mirror, either in a low pressure atmosphere of a gas laser resonator, or in an extra-cavity beam path is made possible through the use of a ventilation system.

  18. High efficiency nanocomposite sorbents for CO2 capture based on amine-functionalized mesoporous capsules

    KAUST Repository

    Qi, Genggeng; Wang, Yanbing; Estevez, Luis; Duan, Xiaonan; Anako, Nkechi; Park, Ah-Hyung Alissa; Li, Wen; Jones, Christopher W.; Giannelis, Emmanuel P.

    2011-01-01

    A novel high efficiency nanocomposite sorbent for CO2 capture has been developed based on oligomeric amine (polyethylenimine, PEI, and tetraethylenepentamine, TEPA) functionalized mesoporous silica capsules. The newly synthesized sorbents exhibit extraordinary capture capacity up to 7.9 mmol g-1 under simulated flue gas conditions (pre-humidified 10% CO 2). The CO2 capture kinetics were found to be fast and reached 90% of the total capacities within the first few minutes. The effects of the mesoporous capsule features such as particle size and shell thickness on CO2 capture capacity were investigated. Larger particle size, higher interior void volume and thinner mesoporous shell thickness all improved the CO2 capacity of the sorbents. PEI impregnated sorbents showed good reversibility and stability during cyclic adsorption-regeneration tests (50 cycles). © 2011 The Royal Society of Chemistry.

  19. High efficiency of CO2-activated graphite felt as electrode for vanadium redox flow battery application

    Science.gov (United States)

    Chang, Yu-Chung; Chen, Jian-Yu; Kabtamu, Daniel Manaye; Lin, Guan-Yi; Hsu, Ning-Yih; Chou, Yi-Sin; Wei, Hwa-Jou; Wang, Chen-Hao

    2017-10-01

    A simple method for preparing CO2-activated graphite felt as an electrode in a vanadium redox flow battery (VRFB) was employed by the direct treatment in a CO2 atmosphere at a high temperature for a short period. The CO2-activated graphite felt demonstrates excellent electrochemical activity and reversibility. The VRFB using the CO2-activated graphite felts in the electrodes has coulombic, voltage, and energy efficiencies of 94.52%, 88.97%, and 84.15%, respectively, which is much higher than VRFBs using the electrodes of untreated graphite felt and N2-activated graphite felt. The efficiency enhancement was attributed to the higher number of oxygen-containing functional groups on the graphite felt that are formed during the CO2-activation, leading to improving the electrochemical behaviour of the resultant VRFB.

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

    Directory of Open Access Journals (Sweden)

    Claudiu Ursu

    2014-12-01

    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.

  1. CO2–CH4 permeation in high zeolite 4A loading mixed matrix membranes

    KAUST Repository

    Adams, Ryan T.

    2011-02-01

    Mixed matrix membranes (MMMs) with low particle loadings have been shown to improve the properties of pure polymers for many gas separations. Comparatively few reports have been made for high particle loading (≥50vol.%) MMMs. In this work, CO2-CH4 feeds were used to study the potential of 50vol.% zeolite 4A-poly(vinyl acetate) (PVAc) MMMs for natural gas separations. A low CO2 partial pressure mixed feed probed MMM performance below the plasticization pressure of PVAc and a high CO2 partial pressure mixed feed probed MMM performance at industrially relevant conditions above the plasticization pressure.Under both mixed feed conditions at 35°C, substantial improvements in overall separation performance were observed. At low CO2 partial pressures, CO2 permeability roughly doubled with a nearly 50% increase in selectivity versus pure PVAc under the same conditions. For the high CO2 partial pressure feed, CO2 permeability remained effectively unchanged with a 63% increase in selectivity versus pure PVAc. Surprisingly, the performance of these PVAc based MMMs approached the properties of current " upper bound" polymers. Overall, this work shows that significantly improved performance MMMs can be made with traditional techniques from a low cost, low performance polymer without costly adhesion promoters. © 2010.

  2. CO2–CH4 permeation in high zeolite 4A loading mixed matrix membranes

    KAUST Repository

    Adams, Ryan T.; Lee, Jong Suk; Bae, Tae-Hyun; Ward, Jason K.; Johnson, J.R.; Jones, Christopher W.; Nair, Sankar; Koros, William J.

    2011-01-01

    Mixed matrix membranes (MMMs) with low particle loadings have been shown to improve the properties of pure polymers for many gas separations. Comparatively few reports have been made for high particle loading (≥50vol.%) MMMs. In this work, CO2-CH4 feeds were used to study the potential of 50vol.% zeolite 4A-poly(vinyl acetate) (PVAc) MMMs for natural gas separations. A low CO2 partial pressure mixed feed probed MMM performance below the plasticization pressure of PVAc and a high CO2 partial pressure mixed feed probed MMM performance at industrially relevant conditions above the plasticization pressure.Under both mixed feed conditions at 35°C, substantial improvements in overall separation performance were observed. At low CO2 partial pressures, CO2 permeability roughly doubled with a nearly 50% increase in selectivity versus pure PVAc under the same conditions. For the high CO2 partial pressure feed, CO2 permeability remained effectively unchanged with a 63% increase in selectivity versus pure PVAc. Surprisingly, the performance of these PVAc based MMMs approached the properties of current " upper bound" polymers. Overall, this work shows that significantly improved performance MMMs can be made with traditional techniques from a low cost, low performance polymer without costly adhesion promoters. © 2010.

  3. Highly Surface-Active Ca(OH)2 Monolayer as a CO2 Capture Material.

    Science.gov (United States)

    Özçelik, V Ongun; Gong, Kai; White, Claire E

    2018-03-14

    Greenhouse gas emissions originating from fossil fuel combustion contribute significantly to global warming, and therefore the design of novel materials that efficiently capture CO 2 can play a crucial role in solving this challenge. Here, we show that reducing the dimensionality of bulk crystalline portlandite results in a stable monolayer material, named portlandene, that is highly effective at capturing CO 2 . On the basis of theoretical analysis comprised of ab initio quantum mechanical calculations and force-field molecular dynamics simulations, we show that this single-layer phase is robust and maintains its stability even at high temperatures. The chemical activity of portlandene is seen to further increase upon defect engineering of its surface using vacancy sites. Defect-containing portlandene is capable of separating CO and CO 2 from a syngas (CO/CO 2 /H 2 ) stream, yet is inert to water vapor. This selective behavior and the associated mechanisms have been elucidated by examining the electronic structure, local charge distribution, and bonding orbitals of portlandene. Additionally, unlike conventional CO 2 capturing technologies, the regeneration process of portlandene does not require high temperature heat treatment because it can release the captured CO 2 by application of a mild external electric field, making portlandene an ideal CO 2 capturing material for both pre- and postcombustion processes.

  4. Ultrathin Composite Polymeric Membranes for CO2 /N2 Separation with Minimum Thickness and High CO2 Permeance.

    Science.gov (United States)

    Benito, Javier; Sánchez-Laínez, Javier; Zornoza, Beatriz; Martín, Santiago; Carta, Mariolino; Malpass-Evans, Richard; Téllez, Carlos; McKeown, Neil B; Coronas, Joaquín; Gascón, Ignacio

    2017-10-23

    The use of ultrathin films as selective layers in composite membranes offers significant advantages in gas separation for increasing productivity while reducing the membrane size and energy costs. In this contribution, composite membranes have been obtained by the successive deposition of approximately 1 nm thick monolayers of a polymer of intrinsic microporosity (PIM) on top of dense membranes of the ultra-permeable poly[1-(trimethylsilyl)-1-propyne] (PTMSP). The ultrathin PIM films (30 nm in thickness) demonstrate CO 2 permeance up to seven times higher than dense PIM membranes using only 0.04 % of the mass of PIM without a significant decrease in CO 2 /N 2 selectivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Highly Efficient Closed-Loop CO2 Removal System for Deep-Space ECLSS, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — TDA Research Inc.(TDA) in collaboration with University of Puerto Rico ? Mayaguez (UPRM is proposing to develop a highly efficient CO2 removal system based on UPRM...

  6. Analysis of Pacific oyster larval proteome and its response to high-CO2

    KAUST Repository

    Dineshram, R.; Wong, Kelvin K.W.; Xiao, Shu; Yu, Ziniu; Qian, Pei Yuan; Thiyagarajan, Vengatesen

    2012-01-01

    Most calcifying organisms show depressed metabolic, growth and calcification rates as symptoms to high-CO2 due to ocean acidification (OA) process. Analysis of the global expression pattern of proteins (proteome analysis) represents a powerful tool

  7. Physiological effects on fishes in a high-CO2 world

    Science.gov (United States)

    Ishimatsu, Atsushi; Hayashi, Masahiro; Lee, Kyoung-Seon; Kikkawa, Takashi; Kita, Jun

    2005-09-01

    Fish are important members of both freshwater and marine ecosystems and constitute a major protein source in many countries. Thus potential reduction of fish resources by high-CO2 conditions due to the diffusion of atmospheric CO2 into the surface waters or direct CO2 injection into the deep sea can be considered as another potential threat to the future world population. Fish, and other water-breathing animals, are more susceptible to a rise in environmental CO2 than terrestrial animals because the difference in CO2 partial pressure (PCO2) of the body fluid of water-breathing animals and ambient medium is much smaller (only a few torr (1 torr = 0.1333 kPa = 1316 μatm)) than in terrestrial animals (typically 30-40 torr). A survey of the literature revealed that hypercapnia acutely affects vital physiological functions such as respiration, circulation, and metabolism, and changes in these functions are likely to reduce growth rate and population size through reproduction failure and change the distribution pattern due to avoidance of high-CO2 waters or reduced swimming activities. This paper reviews the acute and chronic effects of CO2 on fish physiology and tries to clarify necessary areas of future research.

  8. High-precision dual-inlet IRMS measurements of the stable isotopes of CO2 and the N2O / CO2 ratio from polar ice core samples

    Directory of Open Access Journals (Sweden)

    T. K. Bauska

    2014-11-01

    Full Text Available An important constraint on mechanisms of past carbon cycle variability is provided by the stable isotopic composition of carbon in atmospheric carbon dioxide (δ13C-CO2 trapped in polar ice cores, but obtaining very precise measurements has proven to be a significant analytical challenge. Here we describe a new technique to determine the δ13C of CO2 at very high precision, as well as measuring the CO2 and N2O mixing ratios. In this method, ancient air is extracted from relatively large ice samples (~400 g with a dry-extraction "ice grater" device. The liberated air is cryogenically purified to a CO2 and N2O mixture and analyzed with a microvolume-equipped dual-inlet IRMS (Thermo MAT 253. The reproducibility of the method, based on replicate analysis of ice core samples, is 0.02‰ for δ13C-CO2 and 2 ppm and 4 ppb for the CO2 and N2O mixing ratios, respectively (1σ pooled standard deviation. Our experiments show that minimizing water vapor pressure in the extraction vessel by housing the grating apparatus in a ultralow-temperature freezer (−60 °C improves the precision and decreases the experimental blank of the method to −0.07 ± 0.04‰. We describe techniques for accurate calibration of small samples and the application of a mass-spectrometric method based on source fragmentation for reconstructing the N2O history of the atmosphere. The oxygen isotopic composition of CO2 is also investigated, confirming previous observations of oxygen exchange between gaseous CO2 and solid H2O within the ice archive. These data offer a possible constraint on oxygen isotopic fractionation during H2O and CO2 exchange below the H2O bulk melting temperature.

  9. High spin-polarization in ultrathin Co2MnSi/CoPd multilayers

    Science.gov (United States)

    Galanakis, I.

    2015-03-01

    Half-metallic Co2MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co2MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co2MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices.

  10. Oysters and eelgrass: potential partners in a high pCO2 ocean.

    Science.gov (United States)

    Groner, Maya L; Burge, Colleen A; Cox, Ruth; Rivlin, Natalie; Turner, Mo; Van Alstyne, Kathryn L; Wyllie-Echeverria, Sandy; Bucci, John; Staudigel, Philip; Friedman, Carolyn S

    2018-05-25

    Climate change is affecting the health and physiology of marine organisms and altering species interactions. Ocean acidification (OA) threatens calcifying organisms such as the Pacific oyster, Crassostrea gigas. In contrast, seagrasses, such as the eelgrass Zostera marina, can benefit from the increase in available carbon for photosynthesis found at a lower seawater pH. Seagrasses can remove dissolved inorganic carbon from OA environments, creating local daytime pH refugia. Pacific oysters may improve the health of eelgrass by filtering out pathogens such as Labyrinthula zosterae (LZ), which causes eelgrass wasting disease (EWD). We examined how co-culture of eelgrass ramets and juvenile oysters affected the health and growth of eelgrass and the mass of oysters under different pCO 2 exposures. In Phase I, each species was cultured alone or in co-culture at 12°C across ambient, medium, and high pCO 2 conditions, (656, 1158 and1606 μatm pCO 2 , respectively). Under high pCO 2 , eelgrass grew faster and had less severe EWD (contracted in the field prior to the experiment). Co-culture with oysters also reduced the severity of EWD. While the presence of eelgrass decreased daytime pCO 2 , this reduction was not substantial enough to ameliorate the negative impact of high pCO 2 on oyster mass. In Phase II, eelgrass alone or oysters and eelgrass in co-culture were held at 15°C under ambient and high pCO 2 conditions, (488 and 2013 μatm pCO 2 , respectively). Half of the replicates were challenged with cultured LZ. Concentrations of defensive compounds in eelgrass (total phenolics and tannins), were altered by LZ exposure and pCO 2 treatments. Greater pathogen loads and increased EWD severity were detected in LZ exposed eelgrass ramets; EWD severity was reduced at high relative to low pCO 2 . Oyster presence did not influence pathogen load or EWD severity; high LZ concentrations in experimental treatments may have masked the effect of this treatment. Collectively, these

  11. Adsorption of CO2 from flue gas streams by a highly efficient and stable aminosilica adsorbent.

    Science.gov (United States)

    Liu, Shou-Heng; Lin, Yuan-Chung; Chien, Yi-Chi; Hyu, Han-Ren

    2011-02-01

    Three ordered mesoporous silicas (OMSs) with different pore sizes and pore architectures were prepared and modified with amine functional groups by a postgrafting method. The carbon dioxide (CO2) adsorption on these amine-modified OMSs was measured by using microbalances at 348 K, and their adsorption capacities were found to be 0.2-1.4 mmol g(-1) under ambient pressure using dry 15% CO2. It was found experimentally that the CO2 adsorption capacity and adsorption rate were attributed to the density of amine groups and pore volume, respectively. A simple method is described for the production of densely anchored amine groups on a solid adsorbent invoking direct incorporation of tetraethylenepentamine onto the as-synthesized OMSs. Unlike conventional amine-modified OMSs, which typically show CO2 adsorption capacity less than 2 mmol g(-1), such organic template occluded amine-OMS composites possessed remarkably high CO2 uptake of approximately 4.6 mmol g(-1) at 348 K and 1 atm for a dry 15% CO2/nitrogen feed mixture. The enhancement of 8% in CO2 adsorption capacity was also observed in the presence of 10.6% water vapor. Durability tests done by cyclic adsorption-desorption revealed that these adsorbents also possess excellent stability.

  12. Lessons from two high CO2 worlds - future oceans and intensive aquaculture.

    Science.gov (United States)

    Ellis, Robert P; Urbina, Mauricio A; Wilson, Rod W

    2017-06-01

    Exponentially rising CO 2 (currently ~400 μatm) is driving climate change and causing acidification of both marine and freshwater environments. Physiologists have long known that CO 2 directly affects acid-base and ion regulation, respiratory function and aerobic performance in aquatic animals. More recently, many studies have demonstrated that elevated CO 2 projected for end of this century (e.g. 800-1000 μatm) can also impact physiology, and have substantial effects on behaviours linked to sensory stimuli (smell, hearing and vision) both having negative implications for fitness and survival. In contrast, the aquaculture industry was farming aquatic animals at CO 2 levels that far exceed end-of-century climate change projections (sometimes >10 000 μatm) long before the term 'ocean acidification' was coined, with limited detrimental effects reported. It is therefore vital to understand the reasons behind this apparent discrepancy. Potential explanations include 1) the use of 'control' CO 2 levels in aquaculture studies that go beyond 2100 projections in an ocean acidification context; 2) the relatively benign environment in aquaculture (abundant food, disease protection, absence of predators) compared to the wild; 3) aquaculture species having been chosen due to their natural tolerance to the intensive conditions, including CO 2 levels; or 4) the breeding of species within intensive aquaculture having further selected traits that confer tolerance to elevated CO 2 . We highlight this issue and outline the insights that climate change and aquaculture science can offer for both marine and freshwater settings. Integrating these two fields will stimulate discussion on the direction of future cross-disciplinary research. In doing so, this article aimed to optimize future research efforts and elucidate effective mitigation strategies for managing the negative impacts of elevated CO 2 on future aquatic ecosystems and the sustainability of fish and shellfish

  13. Skeletal mineralogy of coral recruits under high temperature and pCO2

    Directory of Open Access Journals (Sweden)

    T. Foster

    2016-03-01

    Our results show that elevated pCO2 alone is unlikely to drive changes in the skeletal mineralogy of young corals. Not having an ability to switch from aragonite to calcite precipitation may leave corals and ultimately coral reef ecosystems more susceptible to predicted ocean acidification. An important area for prospective research would be the investigation of the combined impact of high pCO2 and reduced Mg ∕ Ca ratio on coral skeletal mineralogy.

  14. Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors

    Science.gov (United States)

    Li, Delong; Gong, Youning; Pan, Chunxu

    2016-07-01

    In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage.

  15. Facile synthesis of hybrid CNTs/NiCo2S4 composite for high performance supercapacitors.

    Science.gov (United States)

    Li, Delong; Gong, Youning; Pan, Chunxu

    2016-07-11

    In this work, a novel carbon nanotubes (CNTs)/NiCo2S4 composite for high performance supercapacitors was prepared via a simple chemical bath deposition combined with a post-anion exchange reaction. The morphologies and phase structures of the composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS) and low-temperature sorption of nitrogen (BET). The electro-chemical tests revealed that the CNT/NiCo2S4 composite exhibited high electrochemical performance, because the CNTs were used as a conductive network for the NiCo2S4 hexagonal nanoplates. Compared with pure NiCo2S4 and the mechanically mixed CNTs/NiCo2S4 composite, the CNTs/NiCo2S4 composite electrode material exhibited excellent supercapacitive performance, such as a high specific capacitance up to 1537 F/g (discharge current density of 1 A/g) and an outstanding rate capability of 78.1% retention as the discharge current density increased to 100 A/g. It is therefore expected to be a promising alternative material in the area of energy storage.

  16. Quantification of uncertainty associated with United States high resolution fossil fuel CO2 emissions: updates, challenges and future plans

    Science.gov (United States)

    Gurney, K. R.; Chandrasekaran, V.; Mendoza, D. L.; Geethakumar, S.

    2010-12-01

    The Vulcan Project has estimated United States fossil fuel CO2 emissions at the hourly time scale and at spatial scales below the county level for the year 2002. Vulcan is built from a wide variety of observational data streams including regulated air pollutant emissions reporting, traffic monitoring, energy statistics, and US census data. In addition to these data sets, Vulcan relies on a series of modeling assumptions and constructs to interpolate in space, time and transform non-CO2 reporting into an estimate of CO2 combustion emissions. The recent version 2.0 of the Vulcan inventory has produced advances in a number of categories with particular emphasis on improved temporal structure. Onroad transportation emissions now avail of roughly 5000 automated traffic count monitors allowing for much improved diurnal and weekly time structure in our onroad transportation emissions. Though the inventory shows excellent agreement with independent national-level CO2 emissions estimates, uncertainty quantification has been a challenging task given the large number of data sources and numerous modeling assumptions. However, we have now accomplished a complete uncertainty estimate across all the Vulcan economic sectors and will present uncertainty estimates as a function of space, time, sector and fuel. We find that, like the underlying distribution of CO2 emissions themselves, the uncertainty is also strongly lognormal with high uncertainty associated with a relatively small number of locations. These locations typically are locations reliant upon coal combustion as the dominant CO2 source. We will also compare and contrast Vulcan fossil fuel CO2 emissions estimates against estimates built from DOE fuel-based surveys at the state level. We conclude that much of the difference between the Vulcan inventory and DOE statistics are not due to biased estimation but mechanistic differences in supply versus demand and combustion in space/time.

  17. High spin-polarization in ultrathin Co2MnSi/CoPd multilayers

    International Nuclear Information System (INIS)

    Galanakis, I.

    2015-01-01

    Half-metallic Co 2 MnSi finds a broad spectrum of applications in spintronic devices either in the form of thin films or as spacer in multilayers. Using state-of-the-art ab-initio electronic structure calculations we exploit the electronic and magnetic properties of ultrathin Co 2 MnSi/CoPd multilayers. We show that these heterostructures combine high values of spin-polarization at the Co 2 MnSi spacer with the perpendicular magnetic anisotropy of binary compounds such as CoPd. Thus they could find application in spintronic/magnetoelectronic devices. - Highlights: • Ab-initio study of ultrathin Co 2 MnSi/CoPd multilayers. • Large values of spin-polarization at the Fermi are retained. • Route for novel spintronic/magnetoelectronic devices

  18. Measurement and modeling of high-pressure (vapour + liquid) equilibria of (CO2 + alcohol) binary systems

    International Nuclear Information System (INIS)

    Gutierrez, Jorge E.; Bejarano, Arturo; Fuente, Juan C. de la

    2010-01-01

    An apparatus based on a static-analytic method assembled in this work was utilized to perform high pressure (vapour + liquid) equilibria measurements with uncertainties estimated at 2 + 1-propanol), (CO 2 + 2-methyl-1-propanol), (CO 2 + 3-methyl-1-butanol), and (CO 2 + 1-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 12) MPa. For all the (CO 2 + alcohol) systems, it was visually monitored to insure that there was no liquid immiscibility at the temperatures and pressures studied. The experimental results were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapour + liquid) equilibria compositions were found to be in good agreement with the experimental values with deviations for the mol fractions <0.12 and <0.05 for the liquid and vapour phase, respectively.

  19. Phase equilibrium data and thermodynamic modeling of the system (CO2 + biodiesel + methanol) at high pressures

    International Nuclear Information System (INIS)

    Pinto, Leandro F.; Segalen da Silva, Diogo Italo; Rosa da Silva, Fabiano; Ramos, Luiz P.; Ndiaye, Papa M.; Corazza, Marcos L.

    2012-01-01

    Highlights: → We measured phase behavior for the system involving {CO 2 + biodiesel + methanol}. → The saturation pressures were obtained using a variable-volume view cell. → The experimental data were modeled using PR-vdW2 and PR-WS equations of state. - Abstract: The main objective of this work was to investigate the high pressure phase behavior of the binary systems {CO 2 (1) + methanol(2)} and {CO 2 (1) + soybean methyl esters (biodiesel)(2)} and the ternary system {CO 2 (1) + biodiesel(2) + methanol(3)} were determined. Biodiesel was produced from soybean oil, purified, characterized and used in this work. The static synthetic method, using a variable-volume view cell, was employed to obtain the experimental data in the temperature range of (303.15 to 343.15) K and pressures up to 21 MPa. The mole fractions of carbon dioxide were varied according to the systems as follows: (0.2383 to 0.8666) for the binary system {CO 2 (1) + methanol(2)}; (0.4201 to 0.9931) for the binary system {CO 2 (1) + biodiesel(2)}; (0.4864 to 0.9767) for the ternary system {CO 2 (1) + biodiesel(2) + methanol(3)} with a biodiesel to methanol molar ratio of (1:3); and (0.3732 to 0.9630) for the system {CO 2 + biodiesel + methanol} with a biodiesel to methanol molar ratio of (8:1). For these systems, (vapor + liquid), (liquid + liquid), (vapor + liquid + liquid) transitions were observed. The phase equilibrium data obtained for the systems were modeled using the Peng-Robinson equation of state with the classical van der Waals (PR-vdW2) and Wong-Sandler (PR-WS) mixing rules. Both thermodynamic models were able to satisfactorily correlate the phase behavior of the systems investigated and the PR-WS presented the best performance.

  20. The difference of level CO2 emissions from the transportation sector between weekdays and weekend days on the City Centre of Pemalang

    Science.gov (United States)

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

    2017-06-01

    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.

  1. 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

    2011-01-01

    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.

  2. A new set-up for simultaneous high-precision measurements of CO2, δ13C-CO2 and δ18O-CO2 on small ice core samples

    Science.gov (United States)

    Jenk, Theo Manuel; Rubino, Mauro; Etheridge, David; Ciobanu, Viorela Gabriela; Blunier, Thomas

    2016-08-01

    Palaeoatmospheric records of carbon dioxide and its stable carbon isotope composition (δ13C) obtained from polar ice cores provide important constraints on the natural variability of the carbon cycle. However, the measurements are both analytically challenging and time-consuming; thus only data exist from a limited number of sampling sites and time periods. Additional analytical resources with high analytical precision and throughput are thus desirable to extend the existing datasets. Moreover, consistent measurements derived by independent laboratories and a variety of analytical systems help to further increase confidence in the global CO2 palaeo-reconstructions. Here, we describe our new set-up for simultaneous measurements of atmospheric CO2 mixing ratios and atmospheric δ13C and δ18O-CO2 in air extracted from ice core samples. The centrepiece of the system is a newly designed needle cracker for the mechanical release of air entrapped in ice core samples of 8-13 g operated at -45 °C. The small sample size allows for high resolution and replicate sampling schemes. In our method, CO2 is cryogenically and chromatographically separated from the bulk air and its isotopic composition subsequently determined by continuous flow isotope ratio mass spectrometry (IRMS). In combination with thermal conductivity measurement of the bulk air, the CO2 mixing ratio is calculated. The analytical precision determined from standard air sample measurements over ice is ±1.9 ppm for CO2 and ±0.09 ‰ for δ13C. In a laboratory intercomparison study with CSIRO (Aspendale, Australia), good agreement between CO2 and δ13C results is found for Law Dome ice core samples. Replicate analysis of these samples resulted in a pooled standard deviation of 2.0 ppm for CO2 and 0.11 ‰ for δ13C. These numbers are good, though they are rather conservative estimates of the overall analytical precision achieved for single ice sample measurements. Facilitated by the small sample requirement

  3. High speed surface cleaning by a high repetition rated TEA-CO2 laser

    International Nuclear Information System (INIS)

    Tsunemi, Akira; Hirai, Ryo; Hagiwara, Kouji; Nagasaka, Keigo; Tashiro, Hideo

    1994-01-01

    We demonstrated the feasibility of high speed cleaning of solid surfaces by the laser ablation technique using a TEA-CO 2 laser. The laser pulses with the repetition rate of 1 kHz were applied to paint, rust, moss and dirt attached on the surfaces. The attachments were effectively removed without the damage of bulk surfaces by the irradiation of line-focused sequential pulses with an energy of 300 mJ/pulse. A cleaning rate reached to 17 m 2 /hour for the case of paint removal from iron surfaces. (author)

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

    Directory of Open Access Journals (Sweden)

    Y. Carotenuto

    2008-08-01

    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.

  5. High power CO2 lasers and their applications in nuclear industry

    International Nuclear Information System (INIS)

    Nath, A.K.

    2002-01-01

    Carbon dioxide laser is one of the most popular lasers in industry for material processing applications. It has very high power capability and high efficiency, can be operated in continuous wave (CW), modulated and pulsed modes, and has relatively low cost. Due to these characteristics high power CO 2 lasers are being used worldwide in different industries for a wide variety of materials processing operations. In nuclear industry, CO 2 laser has made its way in many applications. Some of the tasks performed by multikilowatt CO 2 laser are cutting operations necessary to remove unprocessible hardware from reactor fuel assemblies, sealing/fixing/removing radioactive contaminations onto/from concrete surfaces and surface modification of engineering components for improved surface mechanical and metallurgical characteristics. We have developed various models of CW CO 2 lasers of power up to 12 kW and a high repetitive rate TEA (Transversely Excited Atmospheric pressure) CO 2 laser of 500 W average power operating at 500 Hz repetition rates. We have carried many materials processing applications of direct relevance to DAE. Recent work includes laser welding of end plug PFBR fuel tubes, martensitic stainless steel and titanium alloy, surface cladding of turbine blades made of Ni-super alloy with stellite 694, fabrication on graded material of stainless steel and stellite, and laser scabbling, drilling and cutting of concrete which have potential application in decontamination and decommissioning of nuclear facilities. A brief overview of these indigenous developments will be presented. (author)

  6. Porous carbon derived via KOH activation of a hypercrosslinked porous organic polymer for efficient CO_2, CH_4, H_2 adsorptions and high CO_2/N_2 selectivity

    International Nuclear Information System (INIS)

    Modak, Arindam; Bhaumik, Asim

    2015-01-01

    Microporous carbon having Brunauer-Emmett-Teller (BET) surface area of 2186 m"2 g"−"1 and micropore volume of 0.85 cm"3 g"−"1 has been synthesized via KOH induced high temperature carbonization of a non-conjugated hypercrosslinked organic polymer. Owing to the templating and activation by KOH, we have succeeded in making a microporous carbon from this porous polymer and the resultant carbon material showed high uptake for CO_2 (7.6 mmol g"−"1) and CH_4 (2.4 mmol g"−"1) at 1 atm, 273 K together with very good selectivity for the CO_2/N_2 (30.2) separation. Furthermore, low pressure (1 atm) H_2 (2.6 wt%, 77 K) and water uptake (57.4 wt%, 298 K) ability of this polymer derived porous activated carbon is noteworthy. - Graphical abstract: Microporous carbon with BET surface area of 2186 m"2 g"−"1 has been synthesized via KOH activation of a porous organic polymer and it showed high uptake for CO_2 (7.6 mmol g"−"1), CH_4 (2.4 mmol g"−"1) and H_2 (2.6 wt%) at 1 atm together with very good selectivity for CO_2. - Highlights: • Porous carbon from hypercrosslinked organic polymer. • KOH activated carbon with BET surface area 2186 m"2 g"−"1. • High CO2 uptake (7.6 mmol g"−"1) and CO_2/N_2 selectivity (30.2). • Porous carbon also showed high H_2 (2.6 wt%) and H_2O (57.4 wt%) uptakes.

  7. High CO2 and silicate limitation synergistically increase the toxicity of Pseudo-nitzschia fraudulenta.

    Directory of Open Access Journals (Sweden)

    Avery O Tatters

    Full Text Available Anthropogenic CO(2 is progressively acidifying the ocean, but the responses of harmful algal bloom species that produce toxins that can bioaccumulate remain virtually unknown. The neurotoxin domoic acid is produced by the globally-distributed diatom genus Pseudo-nitzschia. This toxin is responsible for amnesic shellfish poisoning, which can result in illness or death in humans and regularly causes mass mortalities of marine mammals and birds. Domoic acid production by Pseudo-nitzschia cells is known to be regulated by nutrient availability, but potential interactions with increasing seawater CO(2 concentrations are poorly understood. Here we present experiments measuring domoic acid production by acclimatized cultures of Pseudo-nitzschia fraudulenta that demonstrate a strong synergism between projected future CO(2 levels (765 ppm and silicate-limited growth, which greatly increases cellular toxicity relative to growth under modern atmospheric (360 ppm or pre-industrial (200 ppm CO(2 conditions. Cellular Si:C ratios decrease with increasing CO(2, in a trend opposite to that seen for domoic acid production. The coastal California upwelling system where this species was isolated currently exhibits rapidly increasing levels of anthropogenic acidification, as well as widespread episodic silicate limitation of diatom growth. Our results suggest that the current ecosystem and human health impacts of toxic Pseudo-nitzschia blooms could be greatly exacerbated by future ocean acidification and 'carbon fertilization' of the coastal ocean.

  8. Changes in Air CO2 Concentration Differentially Alter Transcript Levels of NtAQP1 and NtPIP2;1 Aquaporin Genes in Tobacco Leaves

    Directory of Open Access Journals (Sweden)

    Francesca Secchi

    2016-04-01

    Full Text Available The aquaporin specific control on water versus carbon pathways in leaves is pivotal in controlling gas exchange and leaf hydraulics. We investigated whether Nicotiana tabacum aquaporin 1 (NtAQP1 and Nicotiana tabacum plasma membrane intrinsic protein 2;1 (NtPIP2;1 gene expression varies in tobacco leaves subjected to treatments with different CO2 concentrations (ranging from 0 to 800 ppm, inducing changes in photosynthesis, stomatal regulation and water evaporation from the leaf. Changes in air CO2 concentration ([CO2] affected net photosynthesis (Pn and leaf substomatal [CO2] (Ci. Pn was slightly negative at 0 ppm air CO2; it was one-third that of ambient controls at 200 ppm, and not different from controls at 800 ppm. Leaves fed with 800 ppm [CO2] showed one-third reduced stomatal conductance (gs and transpiration (E, and their gs was in turn slightly lower than in 200 ppm– and in 0 ppm–treated leaves. The 800 ppm air [CO2] strongly impaired both NtAQP1 and NtPIP2;1 gene expression, whereas 0 ppm air [CO2], a concentration below any in vivo possible conditions and specifically chosen to maximize the gene expression alteration, increased only the NtAQP1 transcript level. We propose that NtAQP1 expression, an aquaporin devoted to CO2 transport, positively responds to CO2 scarcity in the air in the whole range 0–800 ppm. On the contrary, expression of NtPIP2;1, an aquaporin not devoted to CO2 transport, is related to water balance in the leaf, and changes in parallel with gs. These observations fit in a model where upregulation of leaf aquaporins is activated at low Ci, while downregulation occurs when high Ci saturates photosynthesis and causes stomatal closure.

  9. Pulse forming networks for fast pumping of high power electron-beam-controlled CO2 lasers

    International Nuclear Information System (INIS)

    Riepe, K.B.

    1975-01-01

    The transverse electric discharge is a widely used technique for pumping CO 2 lasers at high pressures for the generation, simply and efficiently, of very high power laser pulses. The development of the electron-beam-controlled discharge has allowed the application of the transverse discharge to large aperture, very high energy systems. LASL is now in the process of assembly and checkout of a CO 2 laser which is designed to generate a one nanosecond pulse containing 10 kilojoules, for use in laser fusion experiments. The front end of this laser consists of a set of preamplifiers and a mode locked oscillator with electro-optic single pulse switchout. The final amplifier stage consists of four parallel modules, each one consisting of a two-sided electron gun, and two 35 x 35 x 200 cm gas pumping regions operating at a pressure of 1800 torr with a 3/ 1 / 4 /1 (He/N 2 /CO 2 ) laser mix. (auth)

  10. Efficient MgO-based mesoporous CO2 trapper and its performance at high temperature.

    Science.gov (United States)

    Han, Kun Kun; Zhou, Yu; Chun, Yuan; Zhu, Jian Hua

    2012-02-15

    A novel MgO-based porous adsorbent has been synthesized in a facile co-precipitation method for the first time, in order to provide a candidate for trapping CO(2) in flue gas at high temperature. The resulting composite exhibits a mesoporous structure with a wide pore size distribution, due to the even dispersion and distribution of microcrystalline MgO in the framework of alumina to form a concrete-like structure. These sorbents can capture CO(2) at high temperature (150-400°C), possessing high reactivity and stability in cyclic adsorption-desorption processes, providing competitive candidates to control CO(2) emission. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. High temperature H2/CO2 separation using cobalt oxide silica membranes

    Energy Technology Data Exchange (ETDEWEB)

    Smart, S.; Diniz da Costa, J.C. [The University of Queensland, FIMLab - Films and Inorganic Membrane Laboratory, School of Chemical Engineering, Brisbane, Qld 4072 (Australia); Vente, J.F. [Energy research Centre of the Netherlands ECN, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2012-09-15

    In this work high quality cobalt oxide silica membranes were synthesized on alumina supports using a sol-gel, dip coating method. The membranes were subsequently connected into a steel module using a graphite based proprietary sealing method. The sealed membranes were tested for single gas permeance of He, H2, N2 and CO2 at temperatures up to 600C and feed pressures up to 600 kPa. Pressure tests confirmed that the sealing system was effective as no gas leaks were observed during testing. A H2 permeance of 1.9 x 10{sup -7} mol m{sup -2} s{sup -1} Pa-1 was measured in conjunction with a H2/CO2 permselectivity of more than 1500, suggesting that the membranes had a very narrow pore size distribution and an average pore diameter of approximately 3 Angstrom. The high temperature testing demonstrated that the incorporation of cobalt oxide into the silica matrix produced a structure with a higher thermal stability, able to resist thermally induced densification up to at least 600C. Furthermore, the membranes were tested for H2/CO2 binary feed mixtures between 400 and 600C. At these conditions, the reverse of the water gas shift reaction occurred, inadvertently generating CO and water which increased as a function of CO2 feed concentration. The purity of H2 in the permeate stream significantly decreased for CO2 feed concentrations in excess of 50 vol%. However, the gas mixtures (H2, CO2, CO and water) had a more profound effect on the H2 permeate flow rates which significantly decreased, almost exponentially as the CO2 feed concentration increased.

  12. High plant species diversity indirectly mitigates CO 2- and N-induced effects on grasshopper growth

    Science.gov (United States)

    Strengbom, Joachim; Reich, Peter B.; Ritchie, Mark E.

    2008-09-01

    We examined how elevated atmospheric [CO 2] and higher rate of nitrogen (N) input may influence grasshopper growth by changing food plant quality and how such effects may be modified by species diversity of the plant community. We reared grasshopper nymphs ( Melanoplus femurrubrum) on Poa pratensis from field-grown monocultures or polycultures (16 species) that were subjected to either ambient or elevated levels of CO 2 and N. Grasshopper growth rate was higher on P. pratensis leaves grown in monocultures than in polycultures, higher on P. pratensis grown under elevated than under ambient [CO 2], and higher on P. pratensis grown under elevated than under ambient [N]. The higher growth rate observed on P. pratensis exposed to elevated [CO 2] was, however, less pronounced for polyculture- than monoculture-grown P. pratensis. Growth rate of the grasshoppers was positively correlated with leaf [N], [C], and concentration of soluble carbohydrates + lipids. Concentration of non-structural carbohydrates + lipids was higher in leaves grown under elevated than under ambient [CO 2], and the difference between P. pratensis grown under ambient and elevated [CO 2] was greater for monoculture- than polyculture-grown P. pratensis. In addition, leaf N concentration was higher in P. pratensis grown in monocultures than in polycultures, suggesting that plant species richness, indirectly, may influence insect performance by changed nutritional value of the plants. Because we found interactive effects between all factors included ([CO 2], [N], and plant species diversity), our results suggest that these parameters may influence plant-insect interactions in a complex way that is not predictable from the sum of single factor manipulations.

  13. Carbon isotopic evidence for the associations of decreasing atmospheric CO2 level with the Frasnian-Famennian mass extinction

    Science.gov (United States)

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

    2012-03-01

    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.

  14. CFD simulation of CO_2 sorption on K_2CO_3 solid sorbent in novel high flux circulating-turbulent fluidized bed riser: Parametric statistical experimental design study

    International Nuclear Information System (INIS)

    Thummakul, Theeranan; Gidaspow, Dimitri; Piumsomboon, Pornpote; Chalermsinsuwan, Benjapon

    2017-01-01

    Highlights: • Circulating-turbulent fluidization was proved to be advantage on CO_2 sorption. • The novel regime was proven to capture CO_2 higher than the conventional regimes. • Uniform solid particle distribution was observed in the novel fluidization regime. • The system continuity had more effect in the system than the process system mixing. • Parametric experimental design analysis was studied to evaluate significant factor. - Abstract: In this study a high flux circulating-turbulent fluidized bed (CTFB) riser was confirmed to be advantageous for carbon dioxide (CO_2) sorption on a potassium carbonate solid sorbent. The effect of various parameters on the CO_2 removal level was evaluated using a statistical experimental design. The most appropriate fluidization regime was found to occur between the turbulent and fast fluidization regimes, which was shown to capture CO_2 more efficiently than conventional fluidization regimes. The highest CO_2 sorption level was 93.4% under optimized CTFB operating conditions. The important parameters for CO_2 capture were the inlet gas velocity and the interactions between the CO_2 concentration and the inlet gas velocity and water vapor concentration. The CTFB regime had a high and uniform solid particle distribution in both the axial and radial system directions and could transport the solid sorbent to the regeneration reactor. In addition, the process system continuity had a stronger effect on the CO_2 removal level in the system than the process system mixing.

  15. An Innovative Configuration for CO2 Capture by High Temperature Fuel Cells

    Directory of Open Access Journals (Sweden)

    Federico Rossi

    2014-09-01

    Full Text Available Many technological solutions have been proposed for CO2 capture in the last few years. Most of them are characterized by high costs in terms of energy consumption and, consequently, higher fossil fuel use and higher economic costs. High temperature fuel cells are technological solutions currently developed for energy production with low environmental impact. In CIRIAF—University of Perugia labs, cylindrical geometry, small-sized molten carbonate fuel cell (MCFC prototypes were built and tested with good energy production and lifetime performances. In the present work, an innovative application for MCFCs is proposed, and an innovative configuration for CO2 capture/separation is investigated. The plant scheme is based on a reformer and a cylindrical MCFC. MCFCs are the most suitable solutions, because CO2 is used in their operating cycle. An analysis in terms of energy consumption/kgCO2 captured is made by coupling the proposed configuration with a gas turbine plant. The proposed configuration is characterized by a theoretical energy consumption of about 500 kJ/kgCO2, which is quite lower than actual sequestration technologies. An experimental campaign will be scheduled to verify the theoretical findings.

  16. Magnetostriction of some cubic rare earth-Co2 compounds in high magnetic fields

    International Nuclear Information System (INIS)

    Moral, A. del; Melville, D.

    1975-01-01

    Magnetostriction measurements have been carried out in the cubic Laves phase compounds DyCo 2 , HoCo 2 and ErCo 2 from 10 K to well above their respective Neel temperatures Tsub(N). Pulsed magnetic fields up to 15 T (150kOe) were applied. The observed magnetostrictions are very large (approximately 10 -3 ) being similar to those found in the RFe 2 compounds. The measurements confirm the extremely high anisotropy of these materials. At the highest fields the polycrystalline samples are still undergoing rotational magnetization processes. The expected values of the saturation magnetostriction at O K are similar in sign and magnitude to those found in the corresponding rare earth metals. This fact and the scaling of magnetostriction with rare earth sublattice magnetization indicates that the rare earth ion is the main source of the magnetostriction. The metamagnetic transition above Tsub(N) has been studied, the relation between critical field and temperature being nonlinear for HoCo 2 and ErCo 2 . The compounds are highly anisotropic above Tsub(N) and all the features indicate that the field-induced phases are likely to be ferrimagnetic. (author)

  17. High pressure X-ray preionized TEMA-CO2 laser

    NARCIS (Netherlands)

    Bonnie, R.J.M.; Witteman, W.J.

    1987-01-01

    The construction of a high-pressure (up to 20 atm) transversely excited CO2 laser using transverse X-ray preionization is described. High pressure operation was found to be greatly improved in comparison to UV-preionized systems. Homogeneous discharges have been achieved in the pressure range 5–20

  18. Physiological advantages of dwarfing in surviving extinctions in high-CO2 oceans

    Science.gov (United States)

    Garilli, Vittorio; Rodolfo-Metalpa, Riccardo; Scuderi, Danilo; Brusca, Lorenzo; Parrinello, Daniela; Rastrick, Samuel P. S.; Foggo, Andy; Twitchett, Richard J.; Hall-Spencer, Jason M.; Milazzo, Marco

    2015-07-01

    Excessive CO2 in the present-day ocean-atmosphere system is causing ocean acidification, and is likely to cause a severe biodiversity decline in the future, mirroring effects in many past mass extinctions. Fossil records demonstrate that organisms surviving such events were often smaller than those before, a phenomenon called the Lilliput effect. Here, we show that two gastropod species adapted to acidified seawater at shallow-water CO2 seeps were smaller than those found in normal pH conditions and had higher mass-specific energy consumption but significantly lower whole-animal metabolic energy demand. These physiological changes allowed the animals to maintain calcification and to partially repair shell dissolution. These observations of the long-term chronic effects of increased CO2 levels forewarn of changes we can expect in marine ecosystems as CO2 emissions continue to rise unchecked, and support the hypothesis that ocean acidification contributed to past extinction events. The ability to adapt through dwarfing can confer physiological advantages as the rate of CO2 emissions continues to increase.

  19. Physiological basis for high CO2 tolerance in marine ectothermic animals: pre-adaptation through lifestyle and ontogeny?

    Directory of Open Access Journals (Sweden)

    M. Bleich

    2009-10-01

    Full Text Available Future ocean acidification has the potential to adversely affect many marine organisms. A growing body of evidence suggests that many species could suffer from reduced fertilization success, decreases in larval- and adult growth rates, reduced calcification rates, and even mortality when being exposed to near-future levels (year 2100 scenarios of ocean acidification. Little research focus is currently placed on those organisms/taxa that might be less vulnerable to the anticipated changes in ocean chemistry; this is unfortunate, as the comparison of more vulnerable to more tolerant physiotypes could provide us with those physiological traits that are crucial for ecological success in a future ocean. Here, we attempt to summarize some ontogenetic and lifestyle traits that lead to an increased tolerance towards high environmental pCO2. In general, marine ectothermic metazoans with an extensive extracellular fluid volume may be less vulnerable to future acidification as their cells are already exposed to much higher pCO2 values (0.1 to 0.4 kPa, ca. 1000 to 3900 μatm than those of unicellular organisms and gametes, for which the ocean (0.04 kPa, ca. 400 μatm is the extracellular space. A doubling in environmental pCO2 therefore only represents a 10% change in extracellular pCO2 in some marine teleosts. High extracellular pCO2 values are to some degree related to high metabolic rates, as diffusion gradients need to be high in order to excrete an amount of CO2 that is directly proportional to the amount of O2 consumed. In active metazoans, such as teleost fish, cephalopods and many brachyuran crustaceans, exercise induced increases in metabolic rate require an efficient ion-regulatory machinery for CO2 excretion and acid-base regulation, especially when anaerobic metabolism is involved and metabolic protons leak into the extracellular space. These ion-transport systems, which are located in highly developed gill epithelia, form the basis for

  20. High efficiency pump combiner fabricated by CO2 laser splicing system

    Science.gov (United States)

    Zhu, Gongwen

    2018-02-01

    High power combiners are of great interest for high power fiber lasers and fiber amplifiers. With the advent of CO2 laser splicing system, power combiners are made possible with low manufacturing cost, low loss, high reliability and high performance. Traditionally fiber optical components are fabricated with flame torch, electrode arc discharge or filament heater. However, these methods can easily leave contamination on the fiber, resulting inconsistent performance or even catching fire in high power operations. The electrodes or filaments also degrade rapidly during the combiner manufacturing process. The rapid degradation will lead to extensive maintenance, making it unpractical or uneconomic for volume production. By contrast, CO2 laser is the cleanest heating source which provides reliable and repeatable process for fabricating fiber optic components including high power combiners. In this paper we present an all fiber end pumped 7x1 pump combiner fabricated by CO2 laser splicing system. The input pump fibers are 105/125 (core/clad diameters in μm) fibers with a core NA of 0.22. The output fiber is a 300/320 fiber with a core NA of 0.22. The average efficiency is 99.4% with all 7 ports more than 99%. The process is contamination-free and highly repeatable. To our best knowledge, this is the first report in the literature on power combiners fabricated by CO2 laser splicing system. It also has the highest reported efficiency of its kind.

  1. High nitrate to phosphorus regime attenuates negative effects of rising pCO2 on total population carbon accumulation

    Directory of Open Access Journals (Sweden)

    S. A. Krug

    2012-03-01

    Full Text Available The ongoing rise in atmospheric pCO2 and consequent increase in ocean acidification have direct effects on marine calcifying phytoplankton, which potentially alters carbon export. To date it remains unclear, firstly, how nutrient regime, in particular by coccolithophores preferred phosphate limitation, interacts with pCO2 on particulate carbon accumulation; secondly, how direct physiological responses on the cellular level translate into total population response. In this study, cultures of Emiliania huxleyi were full-factorially exposed to two different N:P regimes and three different pCO2 levels. Cellular biovolume and PIC and POC content significantly declined in response to pCO2 in both nutrient regimes. Cellular PON content significantly increased in the Redfield treatment and decreased in the high N:P regime. Cell abundance significantly declined in the Redfield and remained constant in the high N:P regime. We hypothesise that in the high N:P regime severe phosphorous limitation could be compensated either by reduced inorganic phosphorous demand and/or by enzymatic uptake of organic phosphorous. In the Redfield regime we suggest that enzymatic phosphorous uptake to supplement enhanced phosphorous demand with pCO2 was not possible and thus cell abundance declined. These hypothesised different physiological responses of E. huxleyi among the nutrient regimes significantly altered population carrying capacities along the pCO2 gradient. This ultimately led to the attenuated total population response in POC and PIC content and biovolume to increased pCO2 in the high N:P regime. Our results point to the fact that the physiological (i.e. cellular PIC and POC response to ocean acidification cannot be linearly extrapolated to total population response and thus carbon export. It is therefore necessary to consider both effects of nutrient limitation on cell physiology and their consequences for population size when predicting the influence of

  2. Preliminary evidences of CCM operation and its down regulation in relation to increasing CO2 levels in natural phytoplankton assemblages from the coastal waters of Bay of Bengal

    Science.gov (United States)

    Biswas, Haimanti; Rahman Shaik, Aziz Ur; Bandyopadhyay, Debasmita

    2014-05-01

    Bay of Bengal (BoB), a low productive part of the North Indian Ocean, often possesses low CO2 levels in its surface water and diatoms dominate the phytoplankton communities. Virtually no studies are available from this area reporting how this diatom dominated phytoplankton community would respond any increase in dissolved CO2 levels either naturally or anthopogenically. In most of the marine phytoplankton, the inefficiency of the sole carbon fixing enzyme Rubisco necessitates the need of concentrating dissolved inorganic carbon (DIC) (mostly as HCO3) inside the cell in excess of the ambient water concentrations in order to maintain high rate of photosynthesis under low CO2 levels through an energy consuming carbon concentration mechanisms (CCMs). The ubiquitous enzyme carbonic anhydrase (CA) plays a vital role in CCMs by converting HCO3- to CO2 and usually utilizes the trace metal zinc (Zn) as a cofactor. However, it is evident in many marine phytoplankton species that with increasing external CO2 levels, CCMs can be down-regulated leading to energetic savings which can be reallocated to growth; although exceptions occur. Hence, in order to predict their responses to the projected changes, it is imperative to understand their carbon metabolism patterns. We have conducted a series of incubation experiments in microcosms with natural phytoplankton communities from the coastal waters of BoB under different CO2 levels. Our results revealed that the rate of net photosynthetic oxygen evolution and biomass build-up increased in response to increasing CO2 levels. The depletion in δ13CPOM values were more in the high CO2 treatments relative to the low CO2 treated cells (control), indicating that dissolved CO2 uptake was higher when CO2 levels were increased. When additional Zn was added to the low CO2 treated cells, net photosynthetic oxygen evolution rate was increased significantly than that of the untreated control. It is likely that upon the supply of Zn under low CO2

  3. Exploring the Phase Diagram SiO2-CO2 at High Pressures and Temperatures

    Science.gov (United States)

    Kavner, A.

    2015-12-01

    CO2 is an important volatile system relevant for planetary sciences and fundamental chemistry. Molecular CO2 has doubly bonded O=C=O units but high pressure-high temperature (HP-HT) studies have recently shown its transformation into a three-dimensional network of corner-linked [CO4] units analogous to the silica mineral polymorphs, through intermediate non-molecular phases. Here, we report P-V-T data on CO2-IV ice from time-of-flight neutron diffraction experiments, which allow determining the compressibility and thermal expansivity of this intermediate molecular-to-non-molecular phase.1 Aditionally, we have explored the SiO2-CO2 phase diagram and the potential formation of silicon carbonate compounds. New data obtained by laser-heating diamond-anvil experiments in CO2-filled microporous silica polymorphs will be shown. In particular, these HP-HT experiments explore the existence of potential CO2/SiO2 compounds with tetrahedrally-coordinated C/Si atoms by oxygens, which are predicted to be stable (or metastable) by state-of-the-art ab initio simulations.2,3 These theoretical predictions were supported by a recent study that reports the formation of a cristobalite-type Si0.4C0.6O2 solid solution at high-pressures and temperatures, which can be retained as a metastable solid down to ambient conditions.4 Entirely new families of structures could exist based on [CO4]4- units in various degrees of polymerisation, giving rise to a range of chain, sheet and framework solids like those found in silicate chemistry. References[1] S. Palaich et al., Am. Mineral. Submitted (2015) [2] A. Morales-Garcia et al., Theor. Chem. Acc. 132, 1308 (2013) [3] R. Zhou et al., Phys. Rev. X, 4, 011030 (2014) [4] M. Santoro et al. Nature Commun. 5, 3761 (2014)

  4. High CO2 triggers preferential root growth of Arabidopsis thaliana via two distinct systems under low pH and low N stresses.

    Science.gov (United States)

    Hachiya, Takushi; Sugiura, Daisuke; Kojima, Mikiko; Sato, Shigeru; Yanagisawa, Shuichi; Sakakibara, Hitoshi; Terashima, Ichiro; Noguchi, Ko

    2014-02-01

    Biomass allocation between shoots and roots is an important strategy used by plants to optimize growth in various environments. Root to shoot mass ratios typically increase in response to high CO2, a trend particularly evident under abiotic stress. We investigated this preferential root growth (PRG) in Arabidopsis thaliana plants cultivated under low pH/high CO2 or low nitrogen (N)/high CO2 conditions. Previous studies have suggested that changes in plant hormone, carbon (C) and N status may be related to PRG. We therefore examined the mechanisms underlying PRG by genetically modifying cytokinin (CK) levels, C and N status, and sugar signaling, performing sugar application experiments and determining primary metabolites, plant hormones and expression of related genes. Both low pH/high CO2 and low N/high CO2 stresses induced increases in lateral root (LR) number and led to high C/N ratios; however, under low pH/high CO2 conditions, large quantities of C were accumulated, whereas under low N/high CO2 conditions, N was severely depleted. Analyses of a CK-deficient mutant and a starchless mutant, in conjunction with sugar application experiments, revealed that these stresses induce PRG via different mechanisms. Metabolite and hormone profile analysis indicated that under low pH/high CO2 conditions, excess C accumulation may enhance LR number through the dual actions of increased auxin and decreased CKs.

  5. Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records

    Science.gov (United States)

    Martínez-Botí, M. A.; Foster, G. L.; Chalk, T. B.; Rohling, E. J.; Sexton, P. F.; Lunt, D. J.; Pancost, R. D.; Badger, M. P. S.; Schmidt, D. N.

    2015-02-01

    Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2.

  6. Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records.

    Science.gov (United States)

    Martínez-Botí, M A; Foster, G L; Chalk, T B; Rohling, E J; Sexton, P F; Lunt, D J; Pancost, R D; Badger, M P S; Schmidt, D N

    2015-02-05

    Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2.

  7. Low Overpotential and High Current CO2 Reduction with Surface Reconstructed Cu Foam Electrodess

    KAUST Repository

    Min, Shixiong

    2016-06-23

    While recent reports have demonstrated that oxide-derived Cu-based electrodes exhibit high selectivity for CO2 reduction at low overpotential, the low catalytic current density (<2 mA/cm2 at -0.45 V vs. RHE) still largely limits its applications for large-scale fuel synthesis. Here we report an extremely high current density for CO2 reduction at low overpotential using a Cu foam electrode prepared by air-oxidation and subsequent electroreduction. Apart from possessing three-dimensional (3D) open frameworks, the resulting Cu foam electrodes prepared at higher temperatures exhibit enhanced electrochemically active surface area and distinct surface structures. In particular, the Cu foam electrode prepared at 500 °C exhibits an extremely high geometric current density of ~9.4 mA/cm2 in CO2-satrurated 0.1 M KHCO3 aqueous solution and achieving ~39% CO and ~23% HCOOH Faradaic efficiencies at -0.45 V vs. RHE. The high activity and significant selectivity enhancement are attributable to the formation of abundant grain-boundary supported active sites and preferable (100) and (111) facets as a result of reconstruction of Cu surface facets. This work demonstrates that the structural integration of Cu foam with open 3D frameworks and the favorable surface structures is a promising strategy to develop an advanced Cu electrocatalyst that can operate at high current density and low overpotential for CO2 reduction.

  8. VUV-absorption cross section of CO2 at high temperatures and impact on exoplanet atmospheres

    Directory of Open Access Journals (Sweden)

    Venot Olivia

    2014-02-01

    Full Text Available Ultraviolet (UV absorption cross sections are an essential ingredient of photochemical atmosphere models. Exoplanet searches have unveiled a large population of short-period objects with hot atmospheres, very different from what we find in our solar system. Transiting exoplanets whose atmospheres can now be studied by transit spectroscopy receive extremely strong UV fluxes and have typical temperatures ranging from 400 to 2500 K. At these temperatures, UV photolysis cross section data are severely lacking. Our goal is to provide high-temperature absorption cross sections and their temperature dependency for important atmospheric compounds. This study is dedicated to CO2, which is observed and photodissociated in exoplanet atmospheres. We performed these measurements for the 115 - 200 nm range at 300, 410, 480, and 550 K. In the 195 - 230 nm range, we worked at seven temperatures between 465 and 800 K. We found that the absorption cross section of CO2 is very sensitive to temperature, especially above 160 nm. Within the studied range of temperature, the CO2 cross section can vary by more than two orders of magnitude. This, in particular, makes the absorption of CO2 significant up to wavelengths as high as 230 nm, while it is negligible above 200 nm at 300 K. To investigate the influence of these new data on the photochemistry of exoplanets, we implemented the measured cross section into a 1D photochemical model. The model predicts that accounting for this temperature dependency of CO2 cross section can affect the computed abundances of NH3, CO2, and CO by one order of magnitude in the atmospheres of hot Jupiter and hot Neptune.

  9. High-accuracy continuous airborne measurements of greenhouse gases (CO2 and CH4) during BARCA

    Science.gov (United States)

    Chen, H.; Winderlich, J.; Gerbig, C.; Hoefer, A.; Rella, C. W.; Crosson, E. R.; van Pelt, A. D.; Steinbach, J.; Kolle, O.; Beck, V.; Daube, B. C.; Gottlieb, E. W.; Chow, V. Y.; Santoni, G. W.; Wofsy, S. C.

    2009-12-01

    High-accuracy continuous measurements of greenhouse gases (CO2 and CH4) during the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia) phase B campaign in Brazil in May 2009 were accomplished using a newly available analyzer based on the cavity ring-down spectroscopy (CRDS) technique. This analyzer was flown without a drying system or any in-flight calibration gases. Water vapor corrections associated with dilution and pressure-broadening effects for CO2 and CH4 were derived from laboratory experiments employing measurements of water vapor by the CRDS analyzer. Before the campaign, the stability of the analyzer was assessed by laboratory tests under simulated flight conditions. During the campaign, a comparison of CO2 measurements between the CRDS analyzer and a nondispersive infrared (NDIR) analyzer on board the same aircraft showed a mean difference of 0.22±0.09 ppm for all flights over the Amazon rain forest. At the end of the campaign, CO2 concentrations of the synthetic calibration gases used by the NDIR analyzer were determined by the CRDS analyzer. After correcting for the isotope and the pressure-broadening effects that resulted from changes of the composition of synthetic vs. ambient air, and applying those concentrations as calibrated values of the calibration gases to reprocess the CO2 measurements made by the NDIR, the mean difference between the CRDS and the NDIR during BARCA was reduced to 0.05±0.09 ppm, with the mean standard deviation of 0.23±0.05 ppm. The results clearly show that the CRDS is sufficiently stable to be used in flight without drying the air or calibrating in flight and the water corrections are fully adequate for high-accuracy continuous airborne measurements of CO2 and CH4.

  10. Evidence for divergence of response in Indica, Japonica, and wild rice to high CO2 x temperature interaction

    Science.gov (United States)

    Previous studies suggest that the intraspecific variability of rice yield response to rising carbon dioxide concentration, [CO2], could serve as a basis of selection to improve genotypes for future high CO2 conditions. However, assessment of responses to elevated [CO2] must consider air temperature,...

  11. Direct conversion of CO2 into liquid fuels with high selectivity over a bifunctional catalyst

    Science.gov (United States)

    Gao, Peng; Li, Shenggang; Bu, Xianni; Dang, Shanshan; Liu, Ziyu; Wang, Hui; Zhong, Liangshu; Qiu, Minghuang; Yang, Chengguang; Cai, Jun; Wei, Wei; Sun, Yuhan

    2017-10-01

    Although considerable progress has been made in carbon dioxide (CO2) hydrogenation to various C1 chemicals, it is still a great challenge to synthesize value-added products with two or more carbons, such as gasoline, directly from CO2 because of the extreme inertness of CO2 and a high C-C coupling barrier. Here we present a bifunctional catalyst composed of reducible indium oxides (In2O3) and zeolites that yields a high selectivity to gasoline-range hydrocarbons (78.6%) with a very low methane selectivity (1%). The oxygen vacancies on the In2O3 surfaces activate CO2 and hydrogen to form methanol, and C-C coupling subsequently occurs inside zeolite pores to produce gasoline-range hydrocarbons with a high octane number. The proximity of these two components plays a crucial role in suppressing the undesired reverse water gas shift reaction and giving a high selectivity for gasoline-range hydrocarbons. Moreover, the pellet catalyst exhibits a much better performance during an industry-relevant test, which suggests promising prospects for industrial applications.

  12. Low Overpotential and High Current CO2 Reduction with Surface Reconstructed Cu Foam Electrodess

    KAUST Repository

    Min, Shixiong; Yang, Xiulin; Lu, Ang-Yu; Tseng, Chien-Chih; Hedhili, Mohamed N.; Li, Lain-Jong; Huang, Kuo-Wei

    2016-01-01

    for large-scale fuel synthesis. Here we report an extremely high current density for CO2 reduction at low overpotential using a Cu foam electrode prepared by air-oxidation and subsequent electroreduction. Apart from possessing three-dimensional (3D) open

  13. Functional genetic divergence in high CO2 adapted Emiliania huxleyi populations.

    Science.gov (United States)

    Lohbeck, Kai T; Riebesell, Ulf; Collins, Sinéad; Reusch, Thorsten B H

    2013-07-01

    Predicting the impacts of environmental change on marine organisms, food webs, and biogeochemical cycles presently relies almost exclusively on short-term physiological studies, while the possibility of adaptive evolution is often ignored. Here, we assess adaptive evolution in the coccolithophore Emiliania huxleyi, a well-established model species in biological oceanography, in response to ocean acidification. We previously demonstrated that this globally important marine phytoplankton species adapts within 500 generations to elevated CO2 . After 750 and 1000 generations, no further fitness increase occurred, and we observed phenotypic convergence between replicate populations. We then exposed adapted populations to two novel environments to investigate whether or not the underlying basis for high CO2 -adaptation involves functional genetic divergence, assuming that different novel mutations become apparent via divergent pleiotropic effects. The novel environment "high light" did not reveal such genetic divergence whereas growth in a low-salinity environment revealed strong pleiotropic effects in high CO2 adapted populations, indicating divergent genetic bases for adaptation to high CO2 . This suggests that pleiotropy plays an important role in adaptation of natural E. huxleyi populations to ocean acidification. Our study highlights the potential mutual benefits for oceanography and evolutionary biology of using ecologically important marine phytoplankton for microbial evolution experiments. © 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.

  14. The potential effect of high atmospheric CO2 on soil fungi-invertebrate interactions

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Nováková, Alena; Jones, H.

    2002-01-01

    Roč. 8, - (2002), s. 339-344 ISSN 1354-1013 R&D Projects: GA AV ČR IAB6066903 Institutional research plan: CEZ:AV0Z6066911 Keywords : food web * global changes * high CO2 Subject RIV: EH - Ecology, Behaviour Impact factor: 3.398, year: 2002

  15. Effects of CO 2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification

    KAUST Repository

    Omole, Imona C.; Adams, Ryan T.; Miller, Stephen J.; Koros, William J.

    2010-01-01

    A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO2

  16. Absorption capacity and viscosity for CO_2 capture process using high concentrated PZ-DEAE aqueous solution

    International Nuclear Information System (INIS)

    Fu, Dong; Wang, LeMeng; Mi, ChenLu; Zhang, Pan

    2016-01-01

    Highlights: • Absorption of CO_2 in high concentrated DEAE-PZ aqueous solutions were measured. • Viscosities of CO_2-unloaded and CO_2-loaded DEAE-PZ aqueous solutions were measured. • Weiland equation was used to calculate the viscosities. • Effects of temperature, concentration and CO_2 loading on viscosity were demonstrated. - Abstract: The absorption capacity of CO_2 in piperazine (PZ) promoted 2-diethylaminoethanol (DEAE) aqueous solution was measured. The viscosities of both CO_2-unloaded and CO_2-loaded PZ-DEAE aqueous solutions were measured and then modelled. The temperatures ranged from 303.2 K to 323.2 K. The mass fraction of PZ and DEAE respectively ranged from 0 to 0.075 and 0.3 to 0.5. The temperature and concentration dependences of absorption capacity were determined. The effects of temperature, mass fraction and CO_2 loading on viscosities are demonstrated.

  17. Research and survey report of FY 1997 on the CO2 balance for high-temperature CO2 fixation and utilization technology; 1997 nendo chosa hokokusho (nisanka tanso koon bunri gijutsu ni okeru CO2 balance ni kansuru chosa kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The purpose of this research is to clarify the application condition and effectiveness of high-temperature CO2 fixation and utilization technology. To evaluate the present process, it was compared with others, such as separation using a polymer membrane, physico-chemical absorption process, adsorption process, hydrogen contact reduction process, and biological fixation. The development trends of absorption, membrane, adsorption, and cryogenic separation were investigated. The questionnaire was carried out about the separation technologies which are in the stage of performance test using actual gas, to arrange and compare the data and information. The current trends of chemical and biological CO2 fixation and utilization technology were also investigated for arranging the subjects. High-temperature CO2 disposal by the carbonation in concrete waste has been studied, to clarify its application conditions and effectiveness. In order to compare the separation technologies, treatment processes of CO2 in the exhaust gas from boilers of LNG power generation and coal fired power generation were simulated. These processes were simulated by ASPEN PLUS for the modeling. Trends of application of ASPEN PLUS and collection of information were surveyed by participating in the ASPEN WORLD. 103 refs., 51 figs., 55 tabs.

  18. AIRS/Aqua Level 3 Monthly CO2 in the free troposphere (AIRS+AMSU) V005

    Data.gov (United States)

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

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

    Data.gov (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...

  20. AFSC/RACE/FBEP/Hurst: Effects of elevated CO2 levels on eggs and larvae of a North Pacific flatfish

    Data.gov (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...

  1. Carbon Dots/NiCo2 O4 Nanocomposites with Various Morphologies for High Performance Supercapacitors.

    Science.gov (United States)

    Wei, Ji-Shi; Ding, Hui; Zhang, Peng; Song, Yan-Fang; Chen, Jie; Wang, Yong-Gang; Xiong, Huan-Ming

    2016-11-01

    A series of carbon dots/NiCo 2 O 4 composites with various morphologies are prepared and tested for supercapacitors. These samples have good electrical conductivities and efficient ions transport paths, so they exhibit high specific capacitances, superior rate performances, and high cycling stabilities. The optimal composite for hybrid supercapacitor exhibits a high energy density up to 62.0 Wh kg -1 . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Skeletal mineralogy of coral recruits under high temperature and pCO2

    Science.gov (United States)

    Foster, T.; Clode, P. L.

    2016-03-01

    Aragonite, which is the polymorph of CaCO3 precipitated by modern corals during skeletal formation, has a higher solubility than the more stable polymorph calcite. This higher solubility may leave animals that produce aragonitic skeletons more vulnerable to anthropogenic ocean acidification. It is therefore important to determine whether scleractinian corals have the plasticity to adapt and produce calcite in their skeletons in response to changing environmental conditions. Both high pCO2 and lower Mg / Ca ratios in seawater are thought to have driven changes in the skeletal mineralogy of major marine calcifiers in the past ˜ 540 Ma. Experimentally reduced Mg / Ca ratios in ambient seawater have been shown to induce some calcite precipitation in both adult and newly settled modern corals; however, the impact of high pCO2 on the mineralogy of recruits is unknown. Here we determined the skeletal mineralogy of 1-month-old Acropora spicifera coral recruits grown under high temperature (+3 °C) and pCO2 (˜ 900 µatm) conditions, using X-ray diffraction and Raman spectroscopy. We found that newly settled coral recruits produced entirely aragonitic skeletons regardless of the treatment. Our results show that elevated pCO2 alone is unlikely to drive changes in the skeletal mineralogy of young corals. Not having an ability to switch from aragonite to calcite precipitation may leave corals and ultimately coral reef ecosystems more susceptible to predicted ocean acidification. An important area for prospective research would be the investigation of the combined impact of high pCO2 and reduced Mg / Ca ratio on coral skeletal mineralogy.

  3. Paleobotanical Evidence for Near Present-Day Levels of Atmospheric CO2 During Part of the Tertiary

    Science.gov (United States)

    Royer, Dana L.; Wing, Scott L.; Beerling, David J.; Jolley, David W.; Koch, Paul L.; Hickey, Leo J.; Berner, Robert A.

    2001-06-01

    Understanding the link between the greenhouse gas carbon dioxide (CO2) and Earth's temperature underpins much of paleoclimatology and our predictions of future global warming. Here, we use the inverse relationship between leaf stomatal indices and the partial pressure of CO2 in modern Ginkgo biloba and Metasequoia glyptostroboides to develop a CO2 reconstruction based on fossil Ginkgo and Metasequoia cuticles for the middle Paleocene to early Eocene and middle Miocene. Our reconstruction indicates that CO2 remained between 300 and 450 parts per million by volume for these intervals with the exception of a single high estimate near the Paleocene/Eocene boundary. These results suggest that factors in addition to CO2 are required to explain these past intervals of global warmth.

  4. Porous materials as high performance adsorbents for CO2 capture, gas separation and purification

    Science.gov (United States)

    Wang, Jun

    Global warming resulted from greenhouse gases emission has received a widespread attention. Among the greenhouse gases, CO2 contributes more than 60% to global warming due to its huge emission amount. The flue gas contains about 15% CO2 with N2 as the balance. If CO2 can be separated from flue gas, the benefit is not only reducing the global warming effect, but also producing pure CO2 as a very useful industry raw material. Substantial progress is urgent to be achieved in an industrial process. Moreover, energy crisis is one of the biggest challenges for all countries due to the short life of fossil fuels, such as, petroleum will run out in 50 years and coal will run out in 150 years according to today's speed. Moreover, the severe pollution to the environment caused by burning fossil fuels requires us to explore sustainable, environment-friendly, and facile energy sources. Among several alternative energy sources, natural gas is one of the most promising alternative energy sources due to its huge productivity, abundant feed stock, and ease of generation. In order to realize a substantial adsorption process in industry, synthesis of new adsorbents or modification of existing adsorbent with improved properties has become the most critical issue. This dissertation reports systemic characterization and development of five serials of novel adsorbents with advanced adsorption properties. In chapter 2, nitrogen-doped Hypercross-linking Polymers (HCPs) have been synthesized successfully with non-carcinogenic chloromethyl methyl ether (CME) as the cross-linking agent within a single step. Texture properties, surface morphology, CO2/N2 selectivity, and adsorption heat have been presented and demonstrated properly. A comprehensive discussion on factors that affect the CO2 adsorption and CO2/N 2 separation has also been presented. It was found that high micropore proportion and N-content could effectively enhance CO2 uptake and CO2/N2 separation selectivity. In chapter 3, a

  5. Data and modelling requirements for CO2 inversions using high-frequency data

    International Nuclear Information System (INIS)

    Law, R.M.; Rayner, P.J.; Steele, L.P.; Enting, I.G.

    2003-01-01

    We explore the future possibilities for CO 2 source estimation from atmospheric concentration data by performing synthetic data experiments. Synthetic data are used to test seasonal CO 2 inversions using high-frequency data. Monthly CO 2 sources over the Australian region are calculated for inversions with data at 4-hourly frequency and averaged over 1 d, 2.5 d, 5 d, 12.17 d and 1 month. The inversion quality, as determined by bias and uncertainty, is degraded when averaging over longer periods. This shows the value of the strong but relatively short-lived signals present in high-frequency records that are removed in averaged and particularly filtered records. Sensitivity tests are performed in which the synthetic data are 'corrupted' to simulate systematic measurement errors such as intercalibration differences or to simulate transport modelling errors. The inversion is also used to estimate the effect of calibration offsets between sites. We find that at short data-averaging periods the inversion is reasonably robust to measurement-type errors. For transport-type errors, the best results are achieved for synoptic (2-5 d) timescales. Overall the tests indicate that improved source estimates should be possible by incorporating continuous measurements into CO 2 inversions

  6. High-speed high-efficiency 500-W cw CO2 laser hermetization of metal frames of microelectronics devices

    Science.gov (United States)

    Levin, Andrey V.

    1996-04-01

    High-speed, efficient method of laser surface treatment has been developed using (500 W) cw CO2 laser. The principal advantages of CO2 laser surface treatment in comparison with solid state lasers are the basis of the method. It has been affirmed that high efficiency of welding was a consequence of the fundamental properties of metal-IR-radiation (10,6 mkm) interaction. CO2 laser hermetization of metal frames of microelectronic devices is described as an example of the proposed method application.

  7. Absorption of CO2 laser light by a dense, high temperature plasma

    International Nuclear Information System (INIS)

    Peacock, N.J.; Forrest, M.J.; Morgan, P.D.; Offenberger, A.A.

    1977-01-01

    The interaction between a pulsed, CO 2 laser beam and the plasma produced in a plasma focus device is investigated theoretically and experimentally. The CO 2 laser radiation, directed orthogonal to the pinch axis and along the density gradient only weakly perturbs the focus since the radiation density of 30 J cm -3 (allowing for the Airy enhancement factor near the critical layer), is still less than the plasma thermal energy >=1 kJ cm -3 . On the contrary, the CO 2 laser beam is grossly affected by the plasma and absorption during the compressed pinch phase when the plasma frequency is much more complete than can be predicted by classical resistivity. Density fluctuations at the Langmuir frequency are measured directly for forward scattering from a probe, ruby laser beam. Since the wave numbers correspond to approximately 0.1 the Langmuir waves should appear as electron 'lines' in the scattered spectrum shifted by 427 A from the ruby laser wavelength. At low CO 2 laser pump intensity the electron wave intensity is close to the thermal level. As the pump is increased beyond a threshold of approximately 3x10 9 W/cm -2 (in vacuo) enhanced scattering is observed, reaching a factor of 30 above thermal. A WKB treatment of the electron-ion decay instability which takes into account the linear growth of waves at equal electron and ion temperatures and their convection in an inhomogeneous plasma is reasonably consistent with the observations

  8. Ionic Liquid (1-Butyl-3-Metylimidazolium Methane Sulphonate Corrosion and Energy Analysis for High Pressure CO2 Absorption Process

    Directory of Open Access Journals (Sweden)

    Aqeel Ahmad Taimoor

    2018-05-01

    Full Text Available This study explores the possible use of ionic liquids as a solvent in a commercial high-pressure CO2 removal process, to gain environmental and energy benefits. There are two main constraints in realizing this: ionic liquids can be corrosive, specifically when mixed with a water/amine solution with dissolved O2 & CO2; and CO2 absorption within this process is not very well understood. Therefore, scavenging CO2 to ppm levels from process gas comes with several risks. We used 1-butyl-3-methylimidazoium methane sulphonate [bmim][MS] as an ionic liquid because of its high corrosiveness (due to its acidic nature to estimate the ranges of expected corrosion in the process. TAFEL technique was used to determine these rates. Further, the process was simulated based on the conventional absorption–desorption process using ASPEN HYSYS v 8.6. After preliminary model validation with the amine solution, [bmim][MS] was modeled based on the properties found in the literature. The energy comparison was then provided and the optimum ratio of the ionic liquid/amine solution was calculated.

  9. Ultrathin porous NiCo2O4 nanosheet arrays on flexible carbon fabric for high-performance supercapacitors.

    Science.gov (United States)

    Du, Jun; Zhou, Gang; Zhang, Haiming; Cheng, Chao; Ma, Jianmin; Wei, Weifeng; Chen, Libao; Wang, Taihong

    2013-08-14

    NiCo2O4 with higher specific capacitance is an excellent pseudocapacitive material. However, the bulk NiCo2O4 material prevents the achievement of high energy desity and great rate performance due to the limited electroactive surface area. In this work, NiCo2O4 nanosheet arrays were deposited on flexible carbon fabric (CF) as a high-performance electrode for supercapacitors. The NiCo2O4 arrays were constructed by interconnected ultrathin nanosheets (10 nm) with many interparticle pores. The porous feature of NiCo2O4 nanosheets increases the amount of electroactive sites and facilitates the electrolyte penetration. Hence, the NiCo2O4/CF composites exhibited a high specific capacitance of 2658 F g(-1) (2 A g(-1)), good rate performance, and superior cycling life, suggesting the NiCo2O4/CF is a promising electrode material for flexible electrochemical capacitors.

  10. High-resolution quantification of atmospheric CO2 mixing ratios in the Greater Toronto Area, Canada

    Science.gov (United States)

    Pugliese, Stephanie C.; Murphy, Jennifer G.; Vogel, Felix R.; Moran, Michael D.; Zhang, Junhua; Zheng, Qiong; Stroud, Craig A.; Ren, Shuzhan; Worthy, Douglas; Broquet, Gregoire

    2018-03-01

    Many stakeholders are seeking methods to reduce carbon dioxide (CO2) emissions in urban areas, but reliable, high-resolution inventories are required to guide these efforts. We present the development of a high-resolution CO2 inventory available for the Greater Toronto Area and surrounding region in Southern Ontario, Canada (area of ˜ 2.8 × 105 km2, 26 % of the province of Ontario). The new SOCE (Southern Ontario CO2 Emissions) inventory is available at the 2.5 × 2.5 km spatial and hourly temporal resolution and characterizes emissions from seven sectors: area, residential natural-gas combustion, commercial natural-gas combustion, point, marine, on-road, and off-road. To assess the accuracy of the SOCE inventory, we developed an observation-model framework using the GEM-MACH chemistry-transport model run on a high-resolution grid with 2.5 km grid spacing coupled to the Fossil Fuel Data Assimilation System (FFDAS) v2 inventories for anthropogenic CO2 emissions and the European Centre for Medium-Range Weather Forecasts (ECMWF) land carbon model C-TESSEL for biogenic fluxes. A run using FFDAS for the Southern Ontario region was compared to a run in which its emissions were replaced by the SOCE inventory. Simulated CO2 mixing ratios were compared against in situ measurements made at four sites in Southern Ontario - Downsview, Hanlan's Point, Egbert and Turkey Point - in 3 winter months, January-March 2016. Model simulations had better agreement with measurements when using the SOCE inventory emissions versus other inventories, quantified using a variety of statistics such as correlation coefficient, root-mean-square error, and mean bias. Furthermore, when run with the SOCE inventory, the model had improved ability to capture the typical diurnal pattern of CO2 mixing ratios, particularly at the Downsview, Hanlan's Point, and Egbert sites. In addition to improved model-measurement agreement, the SOCE inventory offers a sectoral breakdown of emissions

  11. High-resolution quantification of atmospheric CO2 mixing ratios in the Greater Toronto Area, Canada

    Directory of Open Access Journals (Sweden)

    S. C. Pugliese

    2018-03-01

    Full Text Available Many stakeholders are seeking methods to reduce carbon dioxide (CO2 emissions in urban areas, but reliable, high-resolution inventories are required to guide these efforts. We present the development of a high-resolution CO2 inventory available for the Greater Toronto Area and surrounding region in Southern Ontario, Canada (area of  ∼ 2.8 × 105 km2, 26 % of the province of Ontario. The new SOCE (Southern Ontario CO2 Emissions inventory is available at the 2.5 × 2.5 km spatial and hourly temporal resolution and characterizes emissions from seven sectors: area, residential natural-gas combustion, commercial natural-gas combustion, point, marine, on-road, and off-road. To assess the accuracy of the SOCE inventory, we developed an observation–model framework using the GEM-MACH chemistry–transport model run on a high-resolution grid with 2.5 km grid spacing coupled to the Fossil Fuel Data Assimilation System (FFDAS v2 inventories for anthropogenic CO2 emissions and the European Centre for Medium-Range Weather Forecasts (ECMWF land carbon model C-TESSEL for biogenic fluxes. A run using FFDAS for the Southern Ontario region was compared to a run in which its emissions were replaced by the SOCE inventory. Simulated CO2 mixing ratios were compared against in situ measurements made at four sites in Southern Ontario – Downsview, Hanlan's Point, Egbert and Turkey Point – in 3 winter months, January–March 2016. Model simulations had better agreement with measurements when using the SOCE inventory emissions versus other inventories, quantified using a variety of statistics such as correlation coefficient, root-mean-square error, and mean bias. Furthermore, when run with the SOCE inventory, the model had improved ability to capture the typical diurnal pattern of CO2 mixing ratios, particularly at the Downsview, Hanlan's Point, and Egbert sites. In addition to improved model–measurement agreement, the SOCE inventory offers a

  12. A Highly Stable Microporous Covalent Imine Network Adsorbent for Natural Gas Upgrading and Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan Kumar

    2016-06-06

    The feasible capture and separation of CO2 and N2 from CH4 is an important task for natural gas upgrading and the control of greenhouse gas emissions. Here, we studied the microporous covalent imine networks (CIN) material prepared through Schiff base condensation and exhibited superior chemical robustness under both acidic and basic conditions and high thermal stability. The material possesses a relatively uniform nanoparticle size of approximately 70 to 100 nm. This network featured permanent porosity with a high surface area (722 m2g-1) and micropores. A single-component gas adsorption study showed enhanced CO2 and CH4 uptakes of 3.32 mmol/g and 1.14 mmol/g, respectively, at 273 K and 1 bar, coupled with high separation selectivities for CO2/CH4, CH4/N2, and CO2/N2 of 23, 11.8 and 211, respectively. The enriched Lewis basicity in the porous skeletons favours the interaction of quadrupolar CO2 and polarizable CH4, resulting in enhanced CH4 and CO2 uptake and high CH4/N2, CO2/CH4 and CO2/N2 selectivities. Breakthrough experiments showed high CO2/CH4, CH4/N2 and CO2/N2 selectivities of 7.29, 40 and 125, respectively, at 298 K and 1 bar. High heats of adsorption for CH4 and CO2 (QstCH4; 32.61 kJ mol-1 and QstCO2; 42.42 kJ mol-1) provide the ultimate validation for the high selectivity. To the best of our knowledge, such a versatile adsorbent material that displays both enhanced uptake and selectivity for a variety of binary gas mixtures, including CO2/ CH4, CO2/N2 and CH4/N2, has not been extensively explored.

  13. Seagrass (Posidonia oceanica) seedlings in a high-CO2 world: from physiology to herbivory

    KAUST Repository

    Hernán, Gema

    2016-12-01

    Under future increased CO2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed.

  14. High Pressure Adsorption Isotherm of CO2 on Activated Carbon using Volumetric Method

    Directory of Open Access Journals (Sweden)

    Awaludin Martin

    2011-05-01

    Full Text Available Adsorption system is ones of the most effective methods for CO2 separating with other substances that produced from the burning of fossil fuels. In the design for that application, beside of characteristics of porous material (adsorbent data, CO2 adsorption data on the adsorbent (kinetic and thermodynamic are also needed. The aim of this research is resulting isothermal adsorption data at pressures up to 3.5 MPa by indirect methods (volumetric method at isothermal temperature of 300, 308, 318 and 338 K. Adsorbent that used in this research is activated carbon made from East of Kalimantan coals by physical activation method (CO2 which is the surface area of activated carbon is 668 m2/g and pore volume is 0.47 mL/g. Carbon dioxide (CO2 that used in this research is high purity carbon dioxide with a purity of 99.9%. Data from the experiment results then correlated using the Langmuir and Toth equations model. The results showed that the maximum adsorption capacity is 0.314 kg/kg at 300 K and 3384.69 kPa. The results of regression of experiment data using Langmuir and Toth models were 3.4% and 1.7%.

  15. Seagrass (Posidonia oceanica) seedlings in a high-CO2 world: from physiology to herbivory.

    Science.gov (United States)

    Hernán, Gema; Ramajo, Laura; Basso, Lorena; Delgado, Antonio; Terrados, Jorge; Duarte, Carlos M; Tomas, Fiona

    2016-12-01

    Under future increased CO 2 concentrations, seagrasses are predicted to perform better as a result of increased photosynthesis, but the effects in carbon balance and growth are unclear and remain unexplored for early life stages such as seedlings, which allow plant dispersal and provide the potential for adaptation under changing environmental conditions. Furthermore, the outcome of the concomitant biochemical changes in plant-herbivore interactions has been poorly studied, yet may have important implications in plant communities. In this study we determined the effects of experimental exposure to current and future predicted CO 2 concentrations on the physiology, size and defense strategies against herbivory in the earliest life stage of the Mediterranean seagrass Posidonia oceanica. The photosynthetic performance of seedlings, assessed by fluorescence, improved under increased pCO 2 conditions after 60 days, although these differences disappeared after 90 days. Furthermore, these plants exhibited bigger seeds and higher carbon storage in belowground tissues, having thus more resources to tolerate and recover from stressors. Of the several herbivory resistance traits measured, plants under high pCO 2 conditions had a lower leaf N content but higher sucrose. These seedlings were preferred by herbivorous sea urchins in feeding trials, which could potentially counteract some of the positive effects observed.

  16. Toward reduced transport errors in a high resolution urban CO2 inversion system

    Directory of Open Access Journals (Sweden)

    Aijun Deng

    2017-05-01

    Full Text Available We present a high-resolution atmospheric inversion system combining a Lagrangian Particle Dispersion Model (LPDM and the Weather Research and Forecasting model (WRF, and test the impact of assimilating meteorological observation on transport accuracy. A Four Dimensional Data Assimilation (FDDA technique continuously assimilates meteorological observations from various observing systems into the transport modeling system, and is coupled to the high resolution CO2 emission product Hestia to simulate the atmospheric mole fractions of CO2. For the Indianapolis Flux Experiment (INFLUX project, we evaluated the impact of assimilating different meteorological observation systems on the linearized adjoint solutions and the CO2 inverse fluxes estimated using observed CO2 mole fractions from 11 out of 12 communications towers over Indianapolis for the Sep.-Nov. 2013 period. While assimilating WMO surface measurements improved the simulated wind speed and direction, their impact on the planetary boundary layer (PBL was limited. Simulated PBL wind statistics improved significantly when assimilating upper-air observations from the commercial airline program Aircraft Communications Addressing and Reporting System (ACARS and continuous ground-based Doppler lidar wind observations. Wind direction mean absolute error (MAE decreased from 26 to 14 degrees and the wind speed MAE decreased from 2.0 to 1.2 m s–1, while the bias remains small in all configurations (< 6 degrees and 0.2 m s–1. Wind speed MAE and ME are larger in daytime than in nighttime. PBL depth MAE is reduced by ~10%, with little bias reduction. The inverse results indicate that the spatial distribution of CO2 inverse fluxes were affected by the model performance while the overall flux estimates changed little across WRF simulations when aggregated over the entire domain. Our results show that PBL wind observations are a potent tool for increasing the precision of urban meteorological reanalyses

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

    Science.gov (United States)

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

    2014-06-01

    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.

  18. High pressure X-ray preionized TEMA-CO2 laser

    Science.gov (United States)

    Bonnie, R. J. M.; Witteman, W. J.

    1987-09-01

    The construction of a high-pressure (up to 20 atm) transversely excited CO2 laser using transverse X-ray preionization is described. High pressure operation was found to be greatly improved in comparison to UV-preionized systems. Homogeneous discharges have been achieved in the pressure range 5-20 atm, yielding a specific laser output in the order of 35 J/l.

  19. Technology of discharge and laser resonators for high power CO2 lasers. Koshutsuryoku CO2 laser ni tsukawareru hoden reiki laser kyoshinki gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Takenaka, Y.; Kuzumoto, M. (Mitsubishi Electric Corp., Tokyo (Japan))

    1994-03-20

    This paper describes discharge excitation technology and resonator technology as basic technologies for high power CO2 lasers. As a result of progress in high-frequency power element techniques, the discharge excitation technology now generally uses laser excitation using AC discharge of capacity coupling type. Its representative example is silent discharge (SD) excitation. This is a system to excite laser by applying high voltages with as high frequency as 100 kHz to 1 MHz across a pair of electrodes covered with a dielectric material. The system maintains stability in discharge even if power supply voltage amplitude is modulated, and easily provides pulse outputs. Discharge excitation for diffusion cooled type CO2 laser generates a discharge in a gap with a gap length of about 2 mm, and can perform gas cooling by means of thermal conduction of gas, whereas a compact resonator can be fabricated. A resonator for the diffusion cooled type CO2 laser eliminates gas circulation and cooling systems, hence the device can be made more compact. A report has been given that several of these compact resonators were combined, from which a laser output of 85W was obtained by using RF discharge of 2kW. 43 refs., 21 figs.

  20. Effective Approach for Increasing the Heteroatom Doping Levels of Porous Carbons for Superior CO2 Capture and Separation Performance.

    Science.gov (United States)

    Abdelmoaty, Yomna H; Tessema, Tsemre-Dingel; Norouzi, Nazgol; El-Kadri, Oussama M; Turner, Joseph B McGee; El-Kaderi, Hani M

    2017-10-18

    Development of efficient sorbents for carbon dioxide (CO 2 ) capture from flue gas or its removal from natural gas and landfill gas is very important for environmental protection. A new series of heteroatom-doped porous carbon was synthesized directly from pyrazole/KOH by thermolysis. The resulting pyrazole-derived carbons (PYDCs) are highly doped with nitrogen (14.9-15.5 wt %) as a result of the high nitrogen-to-carbon ratio in pyrazole (43 wt %) and also have a high oxygen content (16.4-18.4 wt %). PYDCs have a high surface area (SA BET = 1266-2013 m 2 g -1 ), high CO 2 Q st (33.2-37.1 kJ mol -1 ), and a combination of mesoporous and microporous pores. PYDCs exhibit significantly high CO 2 uptakes that reach 2.15 and 6.06 mmol g -1 at 0.15 and 1 bar, respectively, at 298 K. At 273 K, the CO 2 uptake improves to 3.7 and 8.59 mmol g -1 at 0.15 and 1 bar, respectively. The reported porous carbons also show significantly high adsorption selectivity for CO 2 /N 2 (128) and CO 2 /CH 4 (13.4) according to ideal adsorbed solution theory calculations at 298 K. Gas breakthrough studies of CO 2 /N 2 (10:90) at 298 K showed that PYDCs display excellent separation properties. The ability to tailor the physical properties of PYDCs as well as their chemical composition provides an effective strategy for designing efficient CO 2 sorbents.

  1. A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT)

    Science.gov (United States)

    Bakker, Dorothee; Landa, Camilla S.; Pfeil, Benjamin; Metzl, Nicolas; O’Brien, Kevin; Olsen, Are; Smith, Karl; Cosca, Cathy; Harasawa, Sumiko; Nakaoka, Shin-ichiro; Jones, Stephen; Nojiri, Yukihiro; Steinhoff, Tobias; Sweeney, Colm; Schuster, Ute; Takahashi, Taro; Tilbrook, Bronte; Wada, Chisato; Wanninkhof, Rik; Alin, Simone R.; Balestrini, Carlos F.; Barbero, Leticia; Bates, Nicholas; Bianchi, Alejandro A.; Bonou, Frédéric; Boutin, Jacqueline; Bozec, Yann; Burger, Eugene F.; Cai, Wei-Jun; Castle, Robert D.; Chen, Liqi; Chierici, Melissa; Currie, Kim; Evans, Wiley; Featherstone, Charles; Feely, Richard; Fransson, Agneta; Goyet, Catherine; Greenwood, Naomi; Gregor, Luke; Hankin, Steven C.; Hardman-Mountford, Nick J.; Harlay, Jérôme; Hauck, Judith; Hoppema, Mario; Humphreys, Matthew P.; Hunt, Christopher W.; Huss, Betty; Ibánhez, J. Severino P.; Johannessen, Truls; Keeling, Ralph F.; Kitidis, Vassilis; Körtzinger, Arne; Kozyr, Alex; Krasakopoulou, Evangelia; Kuwata, Akira; Landschützer, Peter; Lauvset, Siv K.; Lefèvre, Nathalie; Lo Monaco, Claire; Manke, Ansley; Mathis, Jeremy T.; Merlivat, Liliane; Millero, Frank J.; Monteiro, Pedro M. S.; Munro, David R.; Murata, Akihiko; Newberger, Timothy; Omar, Abdirahman M.; Ono, Tsuneo; Paterson, Kristina; Pearce, David; Pierrot, Denis; Robbins, Lisa L.; Saito, Shu; Salisbury, Joe; Schlitzer, Reiner; Schneider, Bernd; Schweitzer, Roland; Sieger, Rainer; Skjelvan, Ingunn; Sullivan, Kevin F.; Sutherland, Stewart C.; Sutton, Adrienne J.; Tadokoro, Kazuaki; Telszewski, Maciej; Tuma, Matthias; van Heuven, Steven M. A. C.; Vandemark, Douglas; Ward, Brian; Watson, Andrew J.; Xu, Suqing

    2016-01-01

    The Surface Ocean CO2 Atlas (SOCAT) is a synthesis of quality-controlled f CO2 (fugacity of carbon dioxide) values for the global surface oceans and coastal seas with regular updates. Version 3 of SOCAT has 14.7 million f CO2 values from 3646 data sets covering the years 1957 to 2014. This latest version has an additional 4.6 million f CO2 values relative to version 2 and extends the record from 2011 to 2014. Version 3 also significantly increases the data availability for 2005 to 2013. SOCAT has an average of approximately 1.2 million surface water f CO2 values per year for the years 2006 to 2012. Quality and documentation of the data has improved. A new feature is the data set quality control (QC) flag of E for data from alternative sensors and platforms. The accuracy of surface water f CO2 has been defined for all data set QC flags. Automated range checking has been carried out for all data sets during their upload into SOCAT. The upgrade of the interactive Data Set Viewer (previously known as the Cruise Data Viewer) allows better interrogation of the SOCAT data collection and rapid creation of high-quality figures for scientific presentations. Automated data upload has been launched for version 4 and will enable more frequent SOCAT releases in the future. High-profile scientific applications of SOCAT include quantification of the ocean sink for atmospheric carbon dioxide and its long-term variation, detection of ocean acidification, as well as evaluation of coupled-climate and ocean-only biogeochemical models. Users of SOCAT data products are urged to acknowledge the contribution of data providers, as stated in the SOCAT Fair Data Use Statement. This ESSD (Earth System Science Data) “living data” publication documents the methods and data sets used for the assembly of this new version of the SOCAT data collection and compares these with those used for earlier versions of the data collection (Pfeil et al., 2013; Sabine et al., 2013; Bakker et al., 2014). 

  2. Future concentrations of atmospheric greenhouse gases CO2, CFC and CH4 - an assessment on the educational level

    International Nuclear Information System (INIS)

    Hoppenau, S.

    1992-01-01

    A model on the educational level is described to estimate effective future atmospheric CO 2 concentrations. The effects of chlorofluorocarbon and methane emission and deforestation are taken into account. The influence of different emission scenarios on the time evolution of greenhouse-gas concentration are illustrated. Future global energy policies are discussed both under the aspects of rising world population and the reduction in global CO 2 emissions. The model can be handled on a PC or even on a pocket calculator

  3. On the mechanism of high product selectivity for HCOOH using Pb in CO2 electroreduction.

    Science.gov (United States)

    Back, Seoin; Kim, Jun-Hyuk; Kim, Yong-Tae; Jung, Yousung

    2016-04-14

    While achieving high product selectivity is one of the major challenges of the CO2 electroreduction technology in general, Pb is one of the few examples with high selectivity that produces formic acid almost exclusively (versus H2, CO, or other byproducts). In this work, we study the mechanism of CO2 electroreduction reactions using Pb to understand the origin of high formic acid selectivity. In particular, we first assess the proton-assisted mechanism proposed in the literature using density functional calculations and find that it cannot fully explain the previous selectivity experiments for the Pb electrode. We then suggest an alternative proton-coupled-electron-transfer mechanism consistent with existing observations, and further validate a new mechanism by experimentally measuring and comparing the onset potentials for CO2 reduction vs. H2 production. We find that the origin of a high selectivity of the Pb catalyst for HCOOH production over CO and H2 lies in the strong O-affinitive and weak C-, H-affinitive characteristics of Pb, leading to the involvement of the *OCHO species as a key intermediate to produce HCOOH exclusively and preventing unwanted H2 production at the same time.

  4. Rapid and Accurate Machine Learning Recognition of High Performing Metal Organic Frameworks for CO2 Capture.

    Science.gov (United States)

    Fernandez, Michael; Boyd, Peter G; Daff, Thomas D; Aghaji, Mohammad Zein; Woo, Tom K

    2014-09-04

    In this work, we have developed quantitative structure-property relationship (QSPR) models using advanced machine learning algorithms that can rapidly and accurately recognize high-performing metal organic framework (MOF) materials for CO2 capture. More specifically, QSPR classifiers have been developed that can, in a fraction of a section, identify candidate MOFs with enhanced CO2 adsorption capacity (>1 mmol/g at 0.15 bar and >4 mmol/g at 1 bar). The models were tested on a large set of 292 050 MOFs that were not part of the training set. The QSPR classifier could recover 945 of the top 1000 MOFs in the test set while flagging only 10% of the whole library for compute intensive screening. Thus, using the machine learning classifiers as part of a high-throughput screening protocol would result in an order of magnitude reduction in compute time and allow intractably large structure libraries and search spaces to be screened.

  5. Hierarchical porous NiCo2O4 nanowires for high-rate supercapacitors.

    Science.gov (United States)

    Jiang, Hao; Ma, Jan; Li, Chunzhong

    2012-05-11

    We demonstrate a simple and scalable strategy for synthesizing hierarchical porous NiCo(2)O(4) nanowires which exhibit a high specific capacitance of 743 F g(-1) at 1 A g(-1) with excellent rate performance (78.6% capacity retention at 40 A g(-1)) and cycling stability (only 6.2% loss after 3000 cycles). This journal is © The Royal Society of Chemistry 2012

  6. High Efficiency Mask Based Laser Materials Processing with TEA-CO2 - and Excimer Laser

    DEFF Research Database (Denmark)

    Bastue, Jens; Olsen, Flemmming Ove

    1997-01-01

    In general, mask based laser materials processing techniques suffer from a very low energy efficiency. We have developed a simple device called an energy enhancer, which is capable of increasing the energy efficiency of typical mask based laser materials processing systems. A short review of the ...... line marking with TEA-CO2 laser of high speed canning lines. The second one is manufactured for marking or microdrilling with excimer laser....

  7. Increase in the activity of fructose-1,6-bisphosphatase in cytosol affects sugar partitioning and increases the lateral shoots in tobacco plants at elevated CO2 levels.

    Science.gov (United States)

    Tamoi, Masahiro; Hiramatsu, Yoshie; Nedachi, Shigeki; Otori, Kumi; Tanabe, Noriaki; Maruta, Takanori; Shigeoka, Shigeru

    2011-05-01

    We generated transgenic tobacco plants with high levels of fructose-1,6-bisphosphatase expressing cyanobacterialfructose-1,6-/sedoheptulose-1,7-bisphosphatase in the cytosol. At ambient CO(2) levels (360 ppm), growth, photosynthetic activity, and fresh weight were unchanged but the sucrose/hexose/starch ratio was slightly altered in the transgenic plants compared with wild-type plants. At elevated CO(2) levels (1200 ppm), lateral shoot, leaf number, and fresh weight were significantly increased in the transgenic plants. Photosynthetic activity was also increased. Hexose accumulated in the upper leaves in the wild-type plants, while sucrose and starch accumulated in the lower leaves and lateral shoots in the transgenic plants. These findings suggest that cytosolic fructose-1,6-bisphosphatase contributes to the efficient conversion of hexose into sucrose, and that the change in carbon partitioning affects photosynthetic capacity and morphogenesis at elevated CO(2) levels.

  8. Net Ecosystem Exchange of CO2 with Rapidly Changing High Arctic Landscapes

    Science.gov (United States)

    Emmerton, C. A.

    2015-12-01

    High Arctic landscapes are expansive and changing rapidly. However our understanding of their functional responses and potential to mitigate or enhance anthropogenic climate change is limited by few measurements. We collected eddy covariance measurements to quantify the net ecosystem exchange (NEE) of CO2 with polar semidesert and meadow wetland landscapes at the highest-latitude location measured to date (82°N). We coupled these rare data with ground and satellite vegetation production measurements (Normalized Difference Vegetation Index; NDVI) to evaluate the effectiveness of upscaling local to regional NEE. During the growing season, the dry polar semidesert landscape was a near zero sink of atmospheric CO2 (NEE: -0.3±13.5 g C m-2). A nearby meadow wetland accumulated over two magnitudes more carbon (NEE: -79.3±20.0 g C m-2) than the polar semidesert landscape, and was similar to meadow wetland NEE at much more southern latitudes. Polar semidesert NEE was most influenced by moisture, with wetter surface soils resulting in greater soil respiration and CO2 emissions. At the meadow wetland, soil heating enhanced plant growth, which in turn increased CO2 uptake. Our upscaling assessment found that polar semidesert NDVI measured on site was low (mean: 0.120-0.157) and similar to satellite measurements (mean: 0.155-0.163). However, weak plant growth resulted in poor satellite NDVI-NEE relationships and created challenges for remotely-detecting changes in the cycling of carbon on the polar semidesert landscape. The meadow wetland appeared more suitable to assess plant production and NEE via remote-sensing, however high Arctic wetland extent is constrained by topography to small areas that may be difficult to resolve with large satellite pixels. We predict that until summer precipitation and humidity increases substantially, climate-related changes of dry high Arctic landscapes may be restricted by poor soil moisture retention, and therefore have some inertia against

  9. CaO-based CO2 sorbents: from fundamentals to the development of new, highly effective materials.

    Science.gov (United States)

    Kierzkowska, Agnieszka M; Pacciani, Roberta; Müller, Christoph R

    2013-07-01

    The enormous anthropogenic emission of the greenhouse gas CO2 is most likely the main reason for climate change. Considering the continuing and indeed growing utilisation of fossil fuels for electricity generation and transportation purposes, development and implementation of processes that avoid the associated emissions of CO2 are urgently needed. CO2 capture and storage, commonly termed CCS, would be a possible mid-term solution to reduce the emissions of CO2 into the atmosphere. However, the costs associated with the currently available CO2 capture technology, that is, amine scrubbing, are prohibitively high, thus making the development of new CO2 sorbents a highly important research challenge. Indeed, CaO, readily obtained through the calcination of naturally occurring limestone, has been proposed as an alternative CO2 sorbent that could substantially reduce the costs of CO2 capture. However, one of the major drawbacks of using CaO derived from natural sources is its rapidly decreasing CO2 uptake capacity with repeated carbonation-calcination reactions. Here, we review the current understanding of fundamental aspects of the cyclic carbonation-calcination reactions of CaO such as its reversibility and kinetics. Subsequently, recent attempts to develop synthetic, CaO-based sorbents that possess high and cyclically stable CO2 uptakes are presented. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Diffusion-cooled high-power single-mode waveguide CO2 laser for transmyocardial revascularization

    Science.gov (United States)

    Berishvili, I. I.; Bockeria, L. A.; Egorov, E. N.; Golubev, Vladimir S.; Galushkin, Michail G.; Kheliminsky, A. A.; Panchenko, Vladislav Y.; Roshin, A. P.; Sigaev, I. Y.; Vachromeeva, M. N.; Vasiltsov, Victor V.; Yoshina, V. I.; Zabelin, Alexandre M.; Zelenov, Evgenii V.

    1999-01-01

    The paper presents the results on investigations and development of multichannel waveguide CO2 laser with diffusion cooling of active medium excited by discharge of audio-frequency alternating current. The description of high-power single-mode CO2 laser with average beam power up to 1 kW is presented. The result of measurement of the laser basic parameters are offered, as well as the outcomes of performances of the laser head with long active zone, operating in waveguide mode. As an example of application of these laser, various capabilities a description of the developed medical system 'Genom' used in the transmyocardial laser revascularization (TMLR) procedure and clinical results of the possibilities of the TMLR in the surgical treatment are presented.

  11. Responses of CO2 Fluxes to Arctic Browning Events in a Range of High Latitude, Shrub-Dominated Ecosystems

    Science.gov (United States)

    Phoenix, G. K.; Treharne, R.; Emberson, L.; Tømmervik, H. A.; Bjerke, J. W.

    2017-12-01

    Climatic and biotic extreme events can result in considerable damage to arctic vegetation, often at landscape and larger scale. These acute events therefore contribute to the browning observed in some arctic regions. It is of considerable concern, therefore, that such extreme events are increasing in frequency as part of climate change. However, despite the increasing importance of browning events, and the considerable impact they can have on ecosystems, to date there is little understanding of their impacts on ecosystem carbon fluxes. To address this, the impacts of a number of different, commonly occurring, extreme events and their subsequent browning (vegetation damage) on key ecosystem CO2 fluxes were assessed during the growing season at a range of event damaged sites of shrub dominated vegetation. Sites were located from the boreal to High Arctic (64˚N-79˚N) and had been previously been damaged by events of frost-drought, extreme winter warming, ground icing and caterpillar (Epirrita autumnata) outbreaks. Plot-level CO2 fluxes of Ecosystem Exchange (NEE), Gross Primary Productivity (GPP) and Ecosystem Respiration (Reco) were assessed using vegetation chambers. At a sub-set of sites, NDVI (greenness) in flux plots was also assessed by hand-held proximal sensor, allowing the relationship between NDVI of damage plots to CO2 flux to be calculated. Despite the contrasting sites and drivers, damage had consistent, major impacts on all fluxes. All sites showed reductions in GPP and NEE with increasing damage, despite efflux from Reco also declining with damage. When scaled to site-level, reductions of up to 81% of NEE, 51% of GPP and 37% of Reco were observed. In the plot-level NDVI-flux relationship, NDVI was shown to explain up to 91% of variation in GPP, and therefore supports the use of NDVI for estimating changes in ecosystem CO2 flux at larger scales in regions where browning has been driven by extreme events. This work is the first attempt to quantify the

  12. Development of high-power CO2 lasers and laser material processing

    Science.gov (United States)

    Nath, Ashish K.; Choudhary, Praveen; Kumar, Manoj; Kaul, R.

    2000-02-01

    Scaling laws to determine the physical dimensions of the active medium and optical resonator parameters for designing convective cooled CO2 lasers have been established. High power CW CO2 lasers upto 5 kW output power and a high repetition rate TEA CO2 laser of 500 Hz and 500 W average power incorporated with a novel scheme for uniform UV pre- ionization have been developed for material processing applications. Technical viability of laser processing of several engineering components, for example laser surface hardening of fine teeth of files, laser welding of martensitic steel shroud and titanium alloy under-strap of turbine, laser cladding of Ni super-alloy with stellite for refurbishing turbine blades were established using these lasers. Laser alloying of pre-placed SiC coating on different types of aluminum alloy, commercially pure titanium and Ti-6Al-4V alloy, and laser curing of thermosetting powder coating have been also studied. Development of these lasers and results of some of the processing studies are briefly presented here.

  13. High temperature capture of CO2 on lithium-based sorbents from rice husk ash.

    Science.gov (United States)

    Wang, Ke; Guo, Xin; Zhao, Pengfei; Wang, Fanzi; Zheng, Chuguang

    2011-05-15

    Highly efficient Li(4)SiO(4) (lithium orthosilicate)-based sorbents for CO(2) capture at high temperature, was developed using waste materials (rice husk ash). Two treated rice husk ash (RHA) samples (RHA1 and RHA2) were prepared and calcined at 800°C in the presence of Li(2)CO(3). Pure Li(4)SiO(4) and RHA-based sorbents were characterized by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, nitrogen adsorption, and thermogravimetry. CO(2) sorption was tested through 15 carbonation/calcination cycles in a fixed bed reactor. The metals of RHA were doped with Li(4)SiO(4) resulting to inhibited growth of the particles and increased pore volume and surface area. Thermal analyses indicated a much better CO(2) absorption in Li(4)SiO(4)-based sorbent prepared from RHA1 (higher metal content sample) because the activation energies for the chemisorption process and diffusion process were smaller than that of pure Li(4)SiO(4). RHA1-based sorbent also maintained higher capacities during the multiple cycles. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Interfacial tension measurement between CO2 and brines under high temperature and elevated pressure conditions

    Science.gov (United States)

    Li, X.; Boek, E. S.; Maitland, G. C.; Trusler, J. P. M.

    2012-04-01

    We have investigated the dependence of interfacial tension of (CO2 + brine) on temperature, pressure and salinity (including both salt type and molality) over the range of conditions applicable to CO2 storage in saline aquifers. The study covered a wide range of measurements of the interfacial tensions between carbon dioxide and (NaCl + KCl)(aq), CaCl2(aq), MgCl2(aq), Na2SO4(aq), KHCO3(aq), NaHCO3(aq) and two laboratory constructed brines with molality ranging from (0.3 to 5.0) mol·kg-1. The measurements were made at temperatures between (298 and 448) K at various pressures up to 50 MPa, using the pendant drop method in a high-pressure view cell filled with water-saturated CO2. The drop to be imaged was created by injecting brine from a high-pressure syringe pump into a capillary sealed through the top of the cell. The expanded uncertainties of the experimental state variables at 95 % confidence are +0.05 K in temperature and +70 kPa in pressure. For the interfacial tension, the overall expanded relative uncertainty at 95 % confidence was +1.6%. The experimental results show that interfacial tension for all the systems increases linearly with molality, indicating that relatively few measurements and simple interpolation procedures are adequate for describing this property accurately over wide ranges of conditions.

  15. Response of marine viral populations to a nutrient induced phytoplankton bloom at different pCO2 levels

    Directory of Open Access Journals (Sweden)

    R.-A. Sandaa

    2008-04-01

    Full Text Available During the PeECE III mesocosm experiment in 2005 we investigated how the virioplankton community responded to increased levels of nutrients (N and P and CO2. We applied a combination of flow cytometry, Pulsed Field Gel Electrophoresis and degenerate PCR primers to categorize and quantify individual viral populations, and to investigate their temporal dynamics. Species specific and degenerate primers enabled us to identify two specific large dsDNA viruses, EhV and CeV, infecting the haptophytes Emiliania huxleyi and Crysochromulina ericina, respectively. Some of the viral populations detected and enumerated by flow cytometry did not respond to altered CO2-levels, but the abundance of EhV and an unidentified dsDNA virus decreased with increasing CO2 levels. Our results thus indicate that CO2 conditions, or the related change in pH, may affect the marine pelagic food web at the viral level. Our results also demonstrate that in order to unravel ecological problems as how CO2 and nutrient levels affect the relationship between marine algal viruses and their hosts, we need to continue the effort to develop molecular markers used to identify both hosts and viruses.

  16. A system for high-quality CO2 isotope analyses of air samples collected by the CARIBIC Airbus A340-600.

    Science.gov (United States)

    Assonov, S; Taylor, P; Brenninkmeijer, C A M

    2009-05-01

    In 2007, JRC-IRMM began a series of atmospheric CO2 isotope measurements, with the focus on understanding instrumental effects, corrections as well as metrological aspects. The calibration approach at JRC-IRMM is based on use of a plain CO2 sample (working reference CO2) as a calibration carrier and CO2-air mixtures (in high-pressure cylinders) to determine the method-related correction under actual analytical conditions (another calibration carrier, in the same form as the samples). Although this approach differs from that in other laboratories, it does give a direct link to the primary reference NBS-19-CO2. It also helps to investigate the magnitude and nature for each of the instrumental corrections and allows for the quantification of the uncertainty introduced. Critical tests were focused on the instrumental corrections. It was confirmed that the use of non-symmetrical capillary crimping (an approach used here to deal with small samples) systematically modifies delta13C(CO2) and delta18O(CO2), with a clear dependence on the amount of extracted CO2. However, the calibration of CO2-air mixtures required the use of the symmetrical dual-inlet mode. As a proof of our approach, we found that delta13C(CO2) on extracts from mixtures agreed (within 0.010 per thousand) with values obtained from the 'mother' CO2 used for the mixtures. It was further found that very low levels of hydrocarbons in the pumping systems and the isotope ratio mass spectrometry (IRMS) instrument itself were critical. The m/z 46 values (consequently the calculated delta18O(CO2) values) are affected by several other effects with traces of air co-trapped with frozen CO2 being the most critical. A careful cryo-distillation of the extracted CO2 is recommended. After extensive testing, optimisation, and routine automated use, the system was found to give precise data on air samples that can be traced with confidence to the primary standards. The typical total combined uncertainty in delta13C(CO2) and

  17. A 13C labelling study on carbon fluxes in Arctic plankton communities under elevated CO2 levels

    Directory of Open Access Journals (Sweden)

    A. de Kluijver

    2013-03-01

    Full Text Available The effect of CO2 on carbon fluxes (production, consumption, and export in Arctic plankton communities was investigated during the 2010 EPOCA (European project on Ocean Acidification mesocosm study off Ny Ålesund, Svalbard. 13C labelled bicarbonate was added to nine mesocosms with a range in pCO2 (185 to 1420 μatm to follow the transfer of carbon from dissolved inorganic carbon (DIC into phytoplankton, bacterial and zooplankton consumers, and export. A nutrient–phytoplankton–zooplankton–detritus model amended with 13C dynamics was constructed and fitted to the data to quantify uptake rates and carbon fluxes in the plankton community. The plankton community structure was characteristic for a post-bloom situation and retention food web and showed high bacterial production (∼31% of primary production, high abundance of mixotrophic phytoplankton, low mesozooplankton grazing (∼6% of primary production and low export (∼7% of primary production. Zooplankton grazing and export of detritus were sensitive to CO2: grazing decreased and export increased with increasing pCO2. Nutrient addition halfway through the experiment increased the export, but not the production rates. Although mixotrophs showed initially higher production rates with increasing CO2, the overall production of POC (particulate organic carbon after nutrient addition decreased with increasing CO2. Interestingly, and contrary to the low nutrient situation, much more material settled down in the sediment traps at low CO2. The observed CO2 related effects potentially alter future organic carbon flows and export, with possible consequences for the efficiency of the biological pump.

  18. The design and development of CO2 medium-level laser power calibration system for industrial and medical applications in Thailand

    Science.gov (United States)

    Nontapot, Kanokwan

    2018-03-01

    The carbon dioxide laser (CO2 laser) is one of the most useful and is the highest CW laser at the present. The laser produces infrared light at 10.6 um. Due to its high power, CO2 lasers are usually used in industrial applications such as cutting and welding, or for engraving at less power. CO2 lasers are also used widely in medical applications, such as laser surgery, skin resurfacing, and removing mold, due to water (biological tissue) absorb light at this wavelength very well. CO2 lasers are also used as LIDAR laser source for military range finding applications because of the transparency of the atmosphere to infrared light. Due to the increasing use of CO2 lasers laser in industrial and medical applications in Thailand, the National Institute of Metrology (Thailand) has set up a CO2 laser power calibration system and provide calibration service to customers this year. The service support calibration of medium-level laser power at wavelength of 10.6 um and at power range 100 mW-10W. The design and development of the calibration system will be presented.

  19. Inactivation of Bacillus subtilis spores by high pressure CO2 with high temperature.

    Science.gov (United States)

    Rao, Lei; Xu, Zhenzhen; Wang, Yongtao; Zhao, Feng; Hu, Xiaosong; Liao, Xiaojun

    2015-07-16

    The objective of this study was to investigate the inactivation of the Bacillus subtilis spores by high pressure CO2 combined with high temperature (HPCD+HT) and to analyze the clumping effect of the spores on their HPCD+HT resistance. The spores of B. subtilis were subjected to heat at 0.1 MPa and HPCD at 6.5-25 MPa, and 82 °C, 86 °C, and 91 °C for 0-120 min. The spores were effectively inactivated by HPCD+HT, but a protective effect on the spores was also found, which was closely correlated to the pressure, temperature and time. The spores treated by HPCD+HT at 6.5 and 10 MPa exhibited a two-stage inactivation curve of shoulder and log-linear regions whereas the spores at 15-25 MPa exhibited a three-stage inactivation curve of shoulder, log-linear and tailing regions, and these curves were well fitted to the Geeraerd model. Approximately 90% of pyridine-2,6-dicarboxylic acid (DPA) was released after HPCD+HT and the 90% DPA release time depend on the pressure and temperature. Moreover, the spore clumping in suspensions was examined by dynamic light scattering. The particle size of the spore suspensions increased with the increase of pressure, temperature and time, indicating the spore clumping. 0.1% Tween 80 as a surfactant inhibited the spore clumping and increased the inactivation ratio of the spores by HPCD+HT. These results indicated that the spore clumping enhanced the spores' resistance to HPCD+HT and induced a protective effect. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Highly efficient Cu-decorated iron oxide nanocatalyst for low pressure CO 2 conversion

    Energy Technology Data Exchange (ETDEWEB)

    Halder, Avik; Kilianová, Martina; Yang, Bing; Tyo, Eric C.; Seifert, Soenke; Prucek, Robert; Panáček, Aleš; Suchomel, Petr; Tomanec, Ondřej; Gosztola, David J.; Milde, David; Wang, Hsien-Hau; Kvítek, Libor; Zbořil, Radek; Vajda, Stefan

    2018-06-01

    We report a nanoparticulate iron oxide based catalyst for CO2 conversion with high efficiency at low pressures and on the effect of the presence of copper on the catalyst's restructuring and its catalytic performance. In situ X-ray scattering reveals the restructuring of the catalyst at the nanometer scale. In situ X-ray absorption near edge structure (XANES) shows the evolution of the composition and oxidation state of the iron and copper components under reaction conditions along with the promotional effect of copper on the chemical transformation of the iron component. X-ray diffraction (XRD), XANES and Raman spectroscopy proved that the starting nano catalyst is composed of iron oxides differing in chemical nature (alpha-Fe2O3, Fe3O4, FeO(OH)) and dimensionality, while the catalyst after CO2 conversion was identified as a mixture of alpha-Fe, Fe3C, and traces of Fe5C2. The significant increase of the rate CO2 is turned over in the presence of copper nanoparticles indicates that Cu nanoparticles activate hydrogen, which after spilling over to the neighbouring iron sites, facilitate a more efficient conversion of carbon dioxide.

  1. Effects of high CO2 on growth and metabolism of Arabidopsis seedlings during growth with a constantly limited supply of nitrogen.

    Science.gov (United States)

    Takatani, Nobuyuki; Ito, Takuro; Kiba, Takatoshi; Mori, Marie; Miyamoto, Tetsuro; Maeda, Shin-Ichi; Omata, Tatsuo

    2014-02-01

    Elevated CO2 has been reported to stimulate plant growth under nitrogen-sufficient conditions, but the effects of CO2 on growth in a constantly nitrogen-limited state, which is relevant to most natural habitats of plants, remain unclear. Here, we maintained Arabidopsis seedlings under such conditions by growing a mutant with reduced nitrate uptake activity on a medium containing nitrate as the sole nitrogen source. Under nitrogen-sufficient conditions (i.e. in the presence of ammonium), growth of shoots and roots of both the wild type (WT) and the mutant was increased approximately 2-fold by elevated CO2. Growth stimulation of shoots and roots by elevated CO2 was observed in the WT growing with nitrate as the sole nitrogen source, but in the mutant grown with nitrate, the high-CO2 conditions stimulated only the growth of roots. In the mutant, elevated CO2 caused well-known symptoms of nitrogen-starved plants, including decreased shoot/root ratio, reduced nitrate content and accumulation of anthocyanin, but also had an increased Chl content in the shoot, which was contradictory to the known effect of nitrogen depletion. A high-CO2-responsive change specific to the mutant was not observed in the levels of the major metabolites, although CO2 responses were observed in the WT and the mutant. These results indicated that elevated CO2 causes nitrogen limitation in the seedlings grown with a constantly limited supply of nitrogen, but the Chl content and the root biomass of the plant increase to enhance the activities of both photosynthesis and nitrogen uptake, while maintaining normal metabolism and response to high CO2.

  2. Design of experimental setup for supercritical CO2 jet under high ambient pressure conditions

    Science.gov (United States)

    Shi, Huaizhong; Li, Gensheng; He, Zhenguo; Wang, Haizhu; Zhang, Shikun

    2016-12-01

    With the commercial extraction of hydrocarbons in shale and tight reservoirs, efficient methods are needed to accelerate developing process. Supercritical CO2 (SC-CO2) jet has been considered as a potential way due to its unique fluid properties. In this article, a new setup is designed for laboratory experiment to research the SC-CO2 jet's characteristics in different jet temperatures, pressures, standoff distances, ambient pressures, etc. The setup is composed of five modules, including SC-CO2 generation system, pure SC-CO2 jet system, abrasive SC-CO2 jet system, CO2 recovery system, and data acquisition system. Now, a series of rock perforating (or case cutting) experiments have been successfully conducted using the setup about pure and abrasive SC-CO2 jet, and the results have proven the great perforating efficiency of SC-CO2 jet and the applications of this setup.

  3. Granular bamboo-derived activated carbon for high CO(2) adsorption: the dominant role of narrow micropores.

    Science.gov (United States)

    Wei, Haoran; Deng, Shubo; Hu, Bingyin; Chen, Zhenhe; Wang, Bin; Huang, Jun; Yu, Gang

    2012-12-01

    Cost-effective biomass-derived activated carbons with a high CO(2) adsorption capacity are attractive for carbon capture. Bamboo was found to be a suitable precursor for activated carbon preparation through KOH activation. The bamboo size in the range of 10-200 mesh had little effect on CO(2) adsorption, whereas the KOH/C mass ratio and activation temperature had a significant impact on CO(2) adsorption. The bamboo-derived activated carbon had a high adsorption capacity and excellent selectivity for CO(2) , and also the adsorption process was highly reversible. The adsorbed amount of CO(2) on the granular activated carbon was up to 7.0 mmol g(-1) at 273 K and 1 bar, which was higher than almost all carbon materials. The pore characteristics of activated carbons responsible for high CO(2) adsorption were fully investigated. Based on the analysis of narrow micropore size distribution of several activated carbons prepared under different conditions, a more accurate micropore range contributing to CO(2) adsorption was proposed. The volume of micropores in the range of 0.33-0.82 nm had a good linear relationship with CO(2) adsorption at 273 K and 1 bar, and the narrow micropores of about 0.55 nm produced the major contribution, which could be used to evaluate CO(2) adsorption on activated carbons. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Highly efficient photochemical HCOOH production from CO2 and water using an inorganic system

    Directory of Open Access Journals (Sweden)

    Satoshi Yotsuhashi

    2012-12-01

    Full Text Available We have constructed a system that uses solar energy to react CO2 with water to generate formic acid (HCOOH at an energy conversion efficiency of 0.15%. It consists of an AlGaN/GaN anode photoelectrode and indium (In cathode that are electrically connected outside of the reactor cell. High energy conversion efficiency is realized due to a high quantum efficiency of 28% at 300 nm, attributable to efficient electron-hole separation in the semiconductor's heterostructure. The efficiency is close to that of natural photosynthesis in plants, and what is more, the reaction product (HCOOH can be used as a renewable energy source.

  5. Effects of high CO2 seawater on the copepod (Acartia tsuensis) through all life stages and subsequent generations

    International Nuclear Information System (INIS)

    Kurihara, Haruko; Ishimatsu, Atsushi

    2008-01-01

    We studied the effects of exposure to seawater equilibrated with CO 2 -enriched air (CO 2 2380 ppm) from eggs to maturity and over two subsequent generations on the copepod Acartia tsuensis. Compared to the control (CO 2 380 ppm), high CO 2 exposure through all life stages of the 1st generation copepods did not significantly affect survival, body size or developmental speed. Egg production and hatching rates were also not significantly different between the initial generation of females exposed to high CO 2 and the 1st and 2nd generation females developed from eggs to maturity in high CO 2 . Thus, the copepods appear more tolerant to increased CO 2 than other marine organisms previously investigated for CO 2 tolerance (i.e., sea urchins and bivalves). However, the crucial importance of copepods in marine ecosystems requires thorough evaluation of the overall impacts of marine environmental changes predicted to occur with increased CO 2 concentrations, i.e., increased temperature, enhanced UV irradiation, and changes in the community structure and nutritional value of phytoplankton

  6. Flow of CO2 ethanol and of CO2 methanol in a non-adiabatic microfluidic T-junction at high pressures

    NARCIS (Netherlands)

    Blanch Ojea, R.; Tiggelaar, Roald M.; Pallares, J.; Grau, F.X.; Gardeniers, Johannes G.E.

    2012-01-01

    In this work, an experimental investigation of the single- and multiphase flows of two sets of fluids, CO2–ethanol and CO2–methanol, in a non-adiabatic microfluidic T-junction is presented. The operating conditions ranged from 7 to 18 MPa, and from 294 to 474 K. The feed mass fraction of CO2 in the

  7. Plant-plant interactions mediate the plastic and genotypic response of Plantago asiatica to CO2 : an experiment with plant populations from naturally high CO2 areas

    NARCIS (Netherlands)

    van Loon, Marloes P; Rietkerk, Max; Dekker, Stefan C; Hikosaka, Kouki; Ueda, Miki U; Anten, Niels P R

    2016-01-01

    Background and Aims The rising atmospheric CO2 concentration ([CO2]) is a ubiquitous selective force that may strongly impact species distribution and vegetation functioning. Plant–plant interactions could mediate the trajectory of vegetation responses to elevated [CO2], because some plants may

  8. Sensitivity of burned area in Europe to climate change, atmospheric CO2 levels, and demography

    DEFF Research Database (Denmark)

    Wu, Minchao; Knorr, Wolfgang; Thonicke, Kirsten

    2015-01-01

    model. Applying a range of future projections that combine different scenarios for climate changes, enhanced CO2 concentrations, and population growth, we investigated the individual and combined effects of these drivers on the total area and regions affected by fire in the 21st century. The two models...

  9. Bringing High-Rate, CO2-Based Microbial Electrosynthesis Closer to Practical Implementation through Improved Electrode Design and Operating Conditions.

    Science.gov (United States)

    Jourdin, Ludovic; Freguia, Stefano; Flexer, Victoria; Keller, Jurg

    2016-02-16

    The enhancement of microbial electrosynthesis (MES) of acetate from CO2 to performance levels that could potentially support practical implementations of the technology must go through the optimization of key design and operating conditions. We report that higher proton availability drastically increases the acetate production rate, with pH 5.2 found to be optimal, which will likely suppress methanogenic activity without inhibitor addition. Applied cathode potential as low as -1.1 V versus SHE still achieved 99% of electron recovery in the form of acetate at a current density of around -200 A m(-2). These current densities are leading to an exceptional acetate production rate of up to 1330 g m(-2) day(-1) at pH 6.7. Using highly open macroporous reticulated vitreous carbon electrodes with macropore sizes of about 0.6 mm in diameter was found to be optimal for achieving a good balance between total surface area available for biofilm formation and effective mass transfer between the bulk liquid and the electrode and biofilm surface. Furthermore, we also successfully demonstrated the use of a synthetic biogas mixture as carbon dioxide source, yielding similarly high MES performance as pure CO2. This would allow this process to be used effectively for both biogas quality improvement and conversion of the available CO2 to acetate.

  10. A Nitrogen-Doped Carbon Catalyst for Electrochemical CO2 Conversion to CO with High Selectivity and Current Density.

    Science.gov (United States)

    Jhong, Huei-Ru Molly; Tornow, Claire E; Smid, Bretislav; Gewirth, Andrew A; Lyth, Stephen M; Kenis, Paul J A

    2017-03-22

    We report characterization of a non-precious metal-free catalyst for the electrochemical reduction of CO 2 to CO; namely, a pyrolyzed carbon nitride and multiwall carbon nanotube composite. This catalyst exhibits a high selectivity for production of CO over H 2 (approximately 98 % CO and 2 % H 2 ), as well as high activity in an electrochemical flow cell. The CO partial current density at intermediate cathode potentials (V=-1.46 V vs. Ag/AgCl) is up to 3.5× higher than state-of-the-art Ag nanoparticle-based catalysts, and the maximum current density is 90 mA cm -2 . The mass activity and energy efficiency (up to 48 %) were also higher than the Ag nanoparticle reference. Moving away from precious metal catalysts without sacrificing activity or selectivity may significantly enhance the prospects of electrochemical CO 2 reduction as an approach to reduce atmospheric CO 2 emissions or as a method for load-leveling in relation to the use of intermittent renewable energy sources. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Viability and adaptation potential of indigenous microorganisms from natural gas field fluids in high pressure incubations with supercritical CO2.

    Science.gov (United States)

    Frerichs, Janin; Rakoczy, Jana; Ostertag-Henning, Christian; Krüger, Martin

    2014-01-21

    Carbon Capture and Storage (CCS) is currently under debate as large-scale solution to globally reduce emissions of the greenhouse gas CO2. Depleted gas or oil reservoirs and saline aquifers are considered as suitable reservoirs providing sufficient storage capacity. We investigated the influence of high CO2 concentrations on the indigenous bacterial population in the saline formation fluids of a natural gas field. Bacterial community changes were closely examined at elevated CO2 concentrations under near in situ pressures and temperatures. Conditions in the high pressure reactor systems simulated reservoir fluids i) close to the CO2 injection point, i.e. saturated with CO2, and ii) at the outer boundaries of the CO2 dissolution gradient. During the incubations with CO2, total cell numbers remained relatively stable, but no microbial sulfate reduction activity was detected. After CO2 release and subsequent transfer of the fluids, an actively sulfate-respiring community was re-established. The predominance of spore-forming Clostridiales provided evidence for the resilience of this taxon against the bactericidal effects of supercritical (sc)CO2. To ensure the long-term safety and injectivity, the viability of fermentative and sulfate-reducing bacteria has to be considered in the selection, design, and operation of CCS sites.

  12. Highly Rechargeable Lithium-CO2 Batteries with a Boron- and Nitrogen-Codoped Holey-Graphene Cathode.

    Science.gov (United States)

    Qie, Long; Lin, Yi; Connell, John W; Xu, Jiantie; Dai, Liming

    2017-06-06

    Metal-air batteries, especially Li-air batteries, have attracted significant research attention in the past decade. However, the electrochemical reactions between CO 2 (0.04 % in ambient air) with Li anode may lead to the irreversible formation of insulating Li 2 CO 3 , making the battery less rechargeable. To make the Li-CO 2 batteries usable under ambient conditions, it is critical to develop highly efficient catalysts for the CO 2 reduction and evolution reactions and investigate the electrochemical behavior of Li-CO 2 batteries. Here, we demonstrate a rechargeable Li-CO 2 battery with a high reversibility by using B,N-codoped holey graphene as a highly efficient catalyst for CO 2 reduction and evolution reactions. Benefiting from the unique porous holey nanostructure and high catalytic activity of the cathode, the as-prepared Li-CO 2 batteries exhibit high reversibility, low polarization, excellent rate performance, and superior long-term cycling stability over 200 cycles at a high current density of 1.0 A g -1 . Our results open up new possibilities for the development of long-term Li-air batteries reusable under ambient conditions, and the utilization and storage of CO 2 . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Arrangement of experiments for simulating the effects of elevated temperatures and elevated CO2 levels on field-sown crops in Finland

    Directory of Open Access Journals (Sweden)

    Kaija Hakala

    1996-01-01

    Full Text Available The experimental plants: spring wheat, winterwheat, spring barley, meadow fescue, potato, strawberry and black currant were sown or planted directly in the field, part of which was covered by an automatically controlled greenhouse to elevate the temperature by 3°C. The temperature of the other part of the field (open field was not elevated, but the field was covered with the same plastic film as the greenhouse to achieve radiation and rainfall conditions comparable to those in the greenhouse. To elevate the CO2 concentrations, four open top chambers (OTC were built for the greenhouse, and four for the open field. Two of these, both in the greenhouse and in the open field, were supplied with pure CO2 to elevate their CO2 level to 700 ppm. The temperatures inside the greenhouse followed accurately the desired level. The relative humidity was somewhat higher in the greenhouse and in the OTC:s than in the open field, especially after the modifications in the ventilation of the greenhouse and in the OTC:s in 1994. Because the OTC:s were large (3 m in diameter, the temperatures inside them differed very little from the surrounding air temperature. The short-term variation in the CO2 concentrations in the OTC:s with elevated CO2 was, however, quite high. The control of the CO2 concentrations improved each year from 1992 to 1994, as the CO2 supplying system was modified. The effects of the experimental conditions on plant growth and phenology are discussed.

  14. Arrangement of experiments for simulating the effects of elevated temperatures and elevated CO2 levels on field-sown crops in Finland

    Directory of Open Access Journals (Sweden)

    K. HAKALA

    2008-12-01

    Full Text Available The experimental plants: spring wheat, winter wheat, spring barley, meadow fescue, potato, strawberry and black currant were sown or planted directly in the field, part of which was covered by an automatically controlled greenhouse to elevate the temperature by 3°C. The temperature of the other part of the field (open field was not elevated, but the field was covered with the same plastic film as the greenhouse to achieve radiation and rainfall conditions comparable to those in the greenhouse. To elevate the CO2 concentrations, four open top chambers (OTC were built for the greenhouse, and four for the open field. Two of these, both in the greenhouse and in the open field, were supplied with pure CO2 to elevate their CO2 level to 700 ppm. The temperatures inside the greenhouse followed accurately the desired level. The relative humidity was somewhat higher in the greenhouse and in the OTC:s than in the open field, especially after the modifications in the ventilation of the greenhouse and in the OTC:s in 1994. Because the OTC:s were large (3 m in diameter, the temperatures inside them differed very little from the surrounding air temperature. The short-term variation in the CO2 concentrations in the OTC:s with elevated CO2 was, however, quite high. The control of the CO2 concentrations improved each year from 1992 to 1994, as the CO2 supplying system was modified. The effects of the experimental conditions on plant growth and phenology are discussed.;

  15. Effect of CO2 enrichment and high photosynthetic photon flux densities (PPFD) on rubisco and PEP-case activities of in vitro cultured strawberry plants

    International Nuclear Information System (INIS)

    Desjardins, Y.; Beeson, R.; Gosselin, A.

    1989-01-01

    Standard growing conditions in vitro (low light and CO 2 ) are not conducive to autotrophy. An experiment was conducted to improve photosynthesis in vitro in the hope of increasing survival in acclimatization. A factorial experiment was elaborated where CO 2 and PPFD were supplied to in vitro cultured strawberry plants in the rooting stage. Activities of carboxylating enzymes were determined after 4 weeks of culture. The activities of non-activated and activated rubisco and PEP-Case were measured after extraction of the enzymes and a reaction with NaH 14 CO 3 followed by scintillation counting spectroscopy. High CO 2 concentration significantly increased net assimilation rates (NAR) by 165% over the control for both 1650 and 3000 ppm CO 2 . High PPFD only increased NAR by 12 and 35% for 150 and 250 μmol·m -2 ·s -1 respectively over the control. Plants grown at 3000 ppm CO 2 had the highest level of chlorophyll/g FW with 97% more than the control. The activity of PEP-Case was the highest at high light levels and high CO 2 with rates of 1.65 for 1650 ppm versus 1.22 mmol CO 2 mg -1 chl. h -1 at 250 μmol·m -2 ·s -1 . There was no difference in PEP activity at low light levels. The rubisco activity was lower at 1650 and 3000 ppm CO 2 . Increases in NAR correlate more closely to the PEP-Case than to Rubisco activity. Physiological significance of high activity of PEP-Case over rubisco will be discussed

  16. Investigation of a high power UV pre-ionized tea CO2 laser for making purposes

    International Nuclear Information System (INIS)

    Tan Shiw Jin; Low Kum Seng

    1988-01-01

    A simple, high-power TEA CO 2 laser using profiled electrodes with capacitatively-coupled side-arcs to provide preionization is described. The output pulse energy, beam size and beam divergence of this laser is measured as well as the voltage across the two laser electrodes. The effect of various operating parameters on the output pulse energy and efficiency of this laser are also described. The laser, with a maximum output energy of 4 J per pulse, has been used successfully to mark plastic surfaces such as plastic Ic components. (author)

  17. Coral Reefs and People in a High-CO2 World: Where Can Science Make a Difference to People?

    Science.gov (United States)

    Langdon, Chris; Ekstrom, Julia A.; Cooley, Sarah R.; Suatoni, Lisa; Beck, Michael W.; Brander, Luke M.; Burke, Lauretta; Cinner, Josh E.; Doherty, Carolyn; Edwards, Peter E. T.; Gledhill, Dwight; Jiang, Li-Qing; van Hooidonk, Ruben J.; Teh, Louise; Waldbusser, George G.; Ritter, Jessica

    2016-01-01

    Reefs and People at Risk Increasing levels of carbon dioxide in the atmosphere put shallow, warm-water coral reef ecosystems, and the people who depend upon them at risk from two key global environmental stresses: 1) elevated sea surface temperature (that can cause coral bleaching and related mortality), and 2) ocean acidification. These global stressors: cannot be avoided by local management, compound local stressors, and hasten the loss of ecosystem services. Impacts to people will be most grave where a) human dependence on coral reef ecosystems is high, b) sea surface temperature reaches critical levels soonest, and c) ocean acidification levels are most severe. Where these elements align, swift action will be needed to protect people’s lives and livelihoods, but such action must be informed by data and science. An Indicator Approach Designing policies to offset potential harm to coral reef ecosystems and people requires a better understanding of where CO2-related global environmental stresses could cause the most severe impacts. Mapping indicators has been proposed as a way of combining natural and social science data to identify policy actions even when the needed science is relatively nascent. To identify where people are at risk and where more science is needed, we map indicators of biological, physical and social science factors to understand how human dependence on coral reef ecosystems will be affected by globally-driven threats to corals expected in a high-CO2 world. Western Mexico, Micronesia, Indonesia and parts of Australia have high human dependence and will likely face severe combined threats. As a region, Southeast Asia is particularly at risk. Many of the countries most dependent upon coral reef ecosystems are places for which we have the least robust data on ocean acidification. These areas require new data and interdisciplinary scientific research to help coral reef-dependent human communities better prepare for a high CO2 world. PMID:27828972

  18. Coral Reefs and People in a High-CO2 World: Where Can Science Make a Difference to People?

    Science.gov (United States)

    Pendleton, Linwood; Comte, Adrien; Langdon, Chris; Ekstrom, Julia A; Cooley, Sarah R; Suatoni, Lisa; Beck, Michael W; Brander, Luke M; Burke, Lauretta; Cinner, Josh E; Doherty, Carolyn; Edwards, Peter E T; Gledhill, Dwight; Jiang, Li-Qing; van Hooidonk, Ruben J; Teh, Louise; Waldbusser, George G; Ritter, Jessica

    2016-01-01

    Increasing levels of carbon dioxide in the atmosphere put shallow, warm-water coral reef ecosystems, and the people who depend upon them at risk from two key global environmental stresses: 1) elevated sea surface temperature (that can cause coral bleaching and related mortality), and 2) ocean acidification. These global stressors: cannot be avoided by local management, compound local stressors, and hasten the loss of ecosystem services. Impacts to people will be most grave where a) human dependence on coral reef ecosystems is high, b) sea surface temperature reaches critical levels soonest, and c) ocean acidification levels are most severe. Where these elements align, swift action will be needed to protect people's lives and livelihoods, but such action must be informed by data and science. Designing policies to offset potential harm to coral reef ecosystems and people requires a better understanding of where CO2-related global environmental stresses could cause the most severe impacts. Mapping indicators has been proposed as a way of combining natural and social science data to identify policy actions even when the needed science is relatively nascent. To identify where people are at risk and where more science is needed, we map indicators of biological, physical and social science factors to understand how human dependence on coral reef ecosystems will be affected by globally-driven threats to corals expected in a high-CO2 world. Western Mexico, Micronesia, Indonesia and parts of Australia have high human dependence and will likely face severe combined threats. As a region, Southeast Asia is particularly at risk. Many of the countries most dependent upon coral reef ecosystems are places for which we have the least robust data on ocean acidification. These areas require new data and interdisciplinary scientific research to help coral reef-dependent human communities better prepare for a high CO2 world.

  19. Coral Reefs and People in a High-CO2 World: Where Can Science Make a Difference to People?

    Directory of Open Access Journals (Sweden)

    Linwood Pendleton

    Full Text Available Increasing levels of carbon dioxide in the atmosphere put shallow, warm-water coral reef ecosystems, and the people who depend upon them at risk from two key global environmental stresses: 1 elevated sea surface temperature (that can cause coral bleaching and related mortality, and 2 ocean acidification. These global stressors: cannot be avoided by local management, compound local stressors, and hasten the loss of ecosystem services. Impacts to people will be most grave where a human dependence on coral reef ecosystems is high, b sea surface temperature reaches critical levels soonest, and c ocean acidification levels are most severe. Where these elements align, swift action will be needed to protect people's lives and livelihoods, but such action must be informed by data and science.Designing policies to offset potential harm to coral reef ecosystems and people requires a better understanding of where CO2-related global environmental stresses could cause the most severe impacts. Mapping indicators has been proposed as a way of combining natural and social science data to identify policy actions even when the needed science is relatively nascent. To identify where people are at risk and where more science is needed, we map indicators of biological, physical and social science factors to understand how human dependence on coral reef ecosystems will be affected by globally-driven threats to corals expected in a high-CO2 world. Western Mexico, Micronesia, Indonesia and parts of Australia have high human dependence and will likely face severe combined threats. As a region, Southeast Asia is particularly at risk. Many of the countries most dependent upon coral reef ecosystems are places for which we have the least robust data on ocean acidification. These areas require new data and interdisciplinary scientific research to help coral reef-dependent human communities better prepare for a high CO2 world.

  20. High-Pressure CO2 Sorption in Polymers of Intrinsic Microporosity under Ultrathin Film Confinement.

    Science.gov (United States)

    Ogieglo, Wojciech; Ghanem, Bader; Ma, Xiaohua; Wessling, Matthias; Pinnau, Ingo

    2018-04-04

    Ultrathin microporous polymer films are pertinent to the development and further spread of nanotechnology with very promising potential applications in molecular separations, sensors, catalysis, or batteries. Here, we report high-pressure CO 2 sorption in ultrathin films of several chemically different polymers of intrinsic microporosity (PIMs), including the prototypical PIM-1. Films with thicknesses down to 7 nm were studied using interference-enhanced in situ spectroscopic ellipsometry. It was found that all PIMs swell much more than non-microporous polystyrene and other high-performance glassy polymers reported previously. Furthermore, chemical modifications of the parent PIM-1 strongly affected the swelling magnitude. By investigating the behavior of relative refractive index, n rel , it was possible to study the interplay between micropores filling and matrix expansion. Remarkably, all studied PIMs showed a maximum in n rel at swelling of 2-2.5% indicating a threshold point above which the dissolution in the dense matrix started to dominate over sorption in the micropores. At pressures above 25 bar, all PIMs significantly plasticized in compressed CO 2 and for the ones with the highest affinity to the penetrant, a liquidlike mixing typical for rubbery polymers was observed. Reduction of film thickness below 100 nm revealed pronounced nanoconfinement effects and resulted in a large swelling enhancement and a quick loss of the ultrarigid character. On the basis of the partial molar volumes of the dissolved CO 2 , the effective reduction of the T g was estimated to be ∼200 °C going from 128 to 7 nm films.

  1. High-Pressure CO2 Sorption in Polymers of Intrinsic Microporosity under Ultrathin Film Confinement

    KAUST Repository

    Ogieglo, Wojciech

    2018-03-12

    Ultrathin microporous polymer films are pertinent to the development and further spread of nanotechnology with very promising potential applications in molecular separations, sensors, catalysis, or batteries. Here, we report high-pressure CO2 sorption in ultrathin films of several chemically different polymers of intrinsic microporosity (PIMs), including the prototypical PIM-1. Films with thicknesses down to 7 nm were studied using interference-enhanced in situ spectroscopic ellipsometry. It was found that all PIMs swell much more than non-microporous polystyrene and other high-performance glassy polymers reported previously. Furthermore, chemical modifications of the parent PIM-1 strongly affected the swelling magnitude. By investigating the behavior of relative refractive index, nrel, it was possible to study the interplay between micropores filling and matrix expansion. Remarkably, all studied PIMs showed a maximum in nrel at swelling of 2-2.5% indicating a threshold point above which the dissolution in the dense matrix started to dominate over sorption in the micropores. At pressures above 25 bar, all PIMs significantly plasticized in compressed CO2 and for the ones with the highest affinity to the penetrant, a liquidlike mixing typical for rubbery polymers was observed. Reduction of film thickness below 100 nm revealed pronounced nanoconfinement effects and resulted in a large swelling enhancement and a quick loss of the ultrarigid character. On the basis of the partial molar volumes of the dissolved CO2, the effective reduction of the Tg was estimated to be ∼200 °C going from 128 to 7 nm films.

  2. High-Pressure CO2 Sorption in Polymers of Intrinsic Microporosity under Ultrathin Film Confinement

    KAUST Repository

    Ogieglo, Wojciech; Ghanem, Bader; Ma, Xiaohua; Wessling, Matthias; Pinnau, Ingo

    2018-01-01

    Ultrathin microporous polymer films are pertinent to the development and further spread of nanotechnology with very promising potential applications in molecular separations, sensors, catalysis, or batteries. Here, we report high-pressure CO2 sorption in ultrathin films of several chemically different polymers of intrinsic microporosity (PIMs), including the prototypical PIM-1. Films with thicknesses down to 7 nm were studied using interference-enhanced in situ spectroscopic ellipsometry. It was found that all PIMs swell much more than non-microporous polystyrene and other high-performance glassy polymers reported previously. Furthermore, chemical modifications of the parent PIM-1 strongly affected the swelling magnitude. By investigating the behavior of relative refractive index, nrel, it was possible to study the interplay between micropores filling and matrix expansion. Remarkably, all studied PIMs showed a maximum in nrel at swelling of 2-2.5% indicating a threshold point above which the dissolution in the dense matrix started to dominate over sorption in the micropores. At pressures above 25 bar, all PIMs significantly plasticized in compressed CO2 and for the ones with the highest affinity to the penetrant, a liquidlike mixing typical for rubbery polymers was observed. Reduction of film thickness below 100 nm revealed pronounced nanoconfinement effects and resulted in a large swelling enhancement and a quick loss of the ultrarigid character. On the basis of the partial molar volumes of the dissolved CO2, the effective reduction of the Tg was estimated to be ∼200 °C going from 128 to 7 nm films.

  3. NiCo2O4 particles with diamond-shaped hexahedron structure for high-performance supercapacitors

    Science.gov (United States)

    Li, Yanfang; Hou, Xiaojuan; Zhang, Zengxing; Hai, Zhenyin; Xu, Hongyan; Cui, Danfeng; Zhuiykov, Serge; Xue, Chenyang

    2018-04-01

    Nickel cobalt oxide (NiCo2O4) particles with a diamond-shaped hexahedral porous sheet structure are successfully synthesized by a facile hydrothermal method, followed by calcination in one step. NiCo2O4-I and NiCo2O4-II particles are prepared using the same method with different contents of urea (CO(NH2)2) and ammonium fluoride (NH4F). The different morphologies of the NiCo2O4-I and NiCo2O4-II particles illustrate that CO(NH2)2 and NH4F play an important role in crystal growth. To verify the influence of NH4F and CO(NH2)2 on the morphology of the NiCo2O4 particles, the theory of crystal growth morphology is analyzed. The electrochemical measurements show that NiCo2O4 particles exhibit a high specific capacitance. At a current density of 1.0 mA cm-2, the mass specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes are 690.75 and 1710.9 F g-1, respectively, in a 6 M KOH aqueous electrolyte. The specific capacitances of the NiCo2O4-I and NiCo2O4-II electrodes remain ∼95.95% and ∼70.58% of the initial capacitance values after 5000 cycles, respectively. According to the two-electrode test, the NiCo2O4-II//AC asymmetric electrodes exhibited an ultrahigh energy density of 64.67 Wh kg-1 at the power density of 12 kW kg-1, demonstrating its excellent application potential as an electrode material for supercapacitors.

  4. Do the rich always become richer? Characterizing the leaf physiological response of the high-yielding rice cultivar Takanari to free-air CO2 enrichment.

    Science.gov (United States)

    Chen, Charles P; Sakai, Hidemitsu; Tokida, Takeshi; Usui, Yasuhiro; Nakamura, Hirofumi; Hasegawa, Toshihiro

    2014-02-01

    The development of crops which are well suited to growth under future environmental conditions such as higher atmospheric CO2 concentrations ([CO2]) is essential to meeting the challenge of ensuring food security in the face of the growing human population and changing climate. A high-yielding indica rice variety (Oryza sativa L. cv. Takanari) has been recently identified as a potential candidate for such breeding, due to its high productivity in present [CO2]. To test if it could further increase its productivity under elevated [CO2] (eCO2), Takanari was grown in the paddy field under season-long free-air CO2 enrichment (FACE, approximately 200 µmol mol(-1) above ambient [CO2]) and its leaf physiology was compared with the representative japonica variety 'Koshihikari'. Takanari showed consistently higher midday photosynthesis and stomatal conductance than Koshihikari under both ambient and FACE growth conditions over 2 years. Maximum ribulose-1,5-bisphosphate carboxylation and electron transport rates were higher for Takanari at the mid-grain filling stage in both years. Mesophyll conductance was higher in Takanari than in Koshihikari at the late grain-filling stage. In contrast to Koshihikari, Takanari grown under FACE conditions showed no decrease in total leaf nitrogen on an area basis relative to ambient-grown plants. Chl content was higher in Takanari than in Koshihikari at the same leaf nitrogen level. These results indicate that Takanari maintains its superiority over Koshihikari in regards to its leaf-level productivity when grown in elevated [CO2] and it may be a valuable resource for rice breeding programs which seek to increase crop productivity under current and future [CO2].

  5. A perfluorinated covalent triazine-based framework for highly selective and water-tolerant CO2 capture

    KAUST Repository

    Zhao, Yunfeng

    2013-01-01

    We designed and synthesized a perfluorinated covalent triazine-based framework (FCTF-1) for selective CO2 capture. The incorporation of fluorine (F) groups played multiple roles in improving the framework\\'s CO 2 adsorption and separation capabilities. Thermodynamically, the strongly polar C-F bonds promoted CO2 adsorption via electrostatic interactions, especially at low pressures. FCTF-1\\'s CO2 uptake was 1.76 mmol g-1 at 273 K and 0.1 bar through equilibrium adsorption, exceeding the CO2 adsorption capacity of any reported porous organic polymers to date. In addition, incorporating F groups produced a significant amount of ultra-micropores (<0.5 nm), which offered not only high gas adsorption potential but also kinetic selectivity for CO2-N 2 separation. In mixed-gas breakthrough experiments, FCTF-1 exhibited an exceptional CO2-N2 selectivity of 77 under kinetic flow conditions, much higher than the selectivity (31) predicted from single-gas equilibrium adsorption data. Moreover, FCTF-1 proved to be tolerant to water and its CO2 capture performance remained excellent when there was moisture in the gas mixture, due to the hydrophobic nature of the C-F bonds. In addition, the moderate adsorbate-adsorbent interaction allowed it to be fully regenerated by pressure swing adsorption processes. These attributes make FCTF-1 a promising sorbent for CO2 capture from flue gas. © 2013 The Royal Society of Chemistry.

  6. Photosynthetic pigments and gas exchange in castor bean under conditions of above the optimal temperature and high CO2

    Directory of Open Access Journals (Sweden)

    Fabiola França Silva

    2015-08-01

    Full Text Available The castor bean plant, a Euphorbiaceae oil seed C3-metabolism rustic and drought-resistant plant, is cultivated in a wide range of environments due to its good adaptive capacity. However, given the current environmental changes, many biochemical and physiological impacts may affect the productivity of important crops, such as castor bean. This work aimed to evaluate the impacts of the castor bean gas exchange in response to high temperature and increased CO2concentration.Our experiment was conducted in a phytotron located at Embrapa Algodão in 2010. We adopted a completely randomized design, with four treatments in a factorial combination of two temperatures (30/20 and 37/30°C and two CO2 levels (400 and 800 mmol L-1; four replications were performed, obtained in five surveys over the growth cycle, for a total of 80 sample units. An infrared gas analyzer (IRGA - Infra Red Gas Analyzer was used for the quantification of the photosynthetic rate, stomatal conductance and transpiration. An increase in the atmospheric CO2 concentration and temperature negatively affected the physiology of the castor bean plants, decreasing the net rate of photosynthesis, transpiration and stomatal conductance.

  7. Amine-Functionalized Amino Acid-based Ionic Liquids as Efficient and High-Capacity Absorbents for CO2

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Kunov-Kruse, Andreas Jonas; Fehrmann, Rasmus

    2014-01-01

    Ionic liquids (ILs) comprised of ammonium cations and anions of naturally occurring amino acids containing an additional amine group (e.g., lysine, histidine, asparagine, and glutamine) were examined as high-capacity absorbents for CO2. An absorption capacity of 2.1 mol CO2 per mol of IL (3.5 mol...

  8. Elevated CO2-mitigation of high temperature stress associated with maintenance of positive carbon balance and carbohydrate accumulation in Kentucky bluegrass.

    Science.gov (United States)

    Song, Yali; Yu, Jingjin; Huang, Bingru

    2014-01-01

    Elevated CO2 concentration may promote plant growth while high temperature is inhibitory for C3 plant species. The interactive effects of elevated CO2 and high temperatures on C3 perennial grass growth and carbon metabolism are not well documented. Kentucky bluegrass (Poa pratensis) plants were exposed to two CO2 levels (400 and 800 μmol mol-1) and five temperatures (15/12, 20/17, 25/22, 30/27, 35/32°C, day/night) in growth chambers. Increasing temperatures to 25°C and above inhibited leaf photosynthetic rate (Pn) and shoot and root growth, but increased leaf respiration rate (R), leading to a negative carbon balance and a decline in soluble sugar content under ambient CO2. Elevated CO2 did not cause shift of optimal temperatures in Kentucky bluegrass, but promoted Pn, shoot and root growth under all levels of temperature (15, 20, 25, 30, and 35°C) and mitigated the adverse effects of severe high temperatures (30 and 35°C). Elevated CO2-mitigation of adverse effects of high temperatures on Kentucky bluegrass growth could be associated with the maintenance of a positive carbon balance and the accumulation of soluble sugars and total nonstructural carbohydrates through stimulation of Pn and suppression of R and respiratory organic acid metabolism.

  9. Chromophoric dissolved organic matter in experimental mesocosms maintained under different pCO2 levels

    OpenAIRE

    Rochelle-Newall, E.; Delille, B.; Frankignoulle, M.; Gattuso, J.-P.; Jacquet, S.; Riebesell, Ulf; Terbrüggen, A.; Zondervan, I.

    2004-01-01

    Chromophoric dissolved organic matter (CDOM) represents the optically active fraction of the bulk dissolved organic matter (DOM) pool. Recent evidence pointed towards a microbial source of CDOM in the aquatic environment and led to the proposal that phytoplankton is not a direct source of CDOM, but that heterotrophic bacteria, through reprocessing of DOM of algal origin, are an important source of CDOM. In a recent experiment designed at looking at the effects of elevated pCO2 on blooms of th...

  10. 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.

    2014-01-01

    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

  11. High-temperature resistivity and thermoelectric properties of coupled substituted Ca3Co2O6

    Directory of Open Access Journals (Sweden)

    Meenakshisundaram Senthilkumar and Rajagopalan Vijayaraghavan

    2009-01-01

    Full Text Available Polycrystalline samples of Ca3−xNaxCo2−xMnxO6 (x=0.0–0.5 have been prepared by the sol-gel cum combustion method using sucrose in order to investigate the effects of the coupled substitution of Na and Mn on Ca and Co sites on the transport properties of Ca3Co2O6(Co326. The products were characterized by Fourier transform infrared spectroscopy, powder x-ray diffraction (XRD, thermogravimetry (TGA, differential thermal analysis and scanning electron microscopy. XRD patterns reveal the formation of single-phase products up to x=0.5. Coupled substitution increases the solubility of both Na and Mn on Ca and Co sites, respectively, in contrast to the limited solubility of Na and Mn (x=0.2 when separately substituted. TGA confirms the formation of the Ca3Co2O6 phase at temperatures ~720 °C. The grain size of the parent and substituted products is in the range 150–250 nm. Electrical resistivity and Seebeck coefficient were measured in the temperature range 300–800 K. Resistivity shows semiconducting behavior for all the compositions, particularly in the low-temperature regime. The Seebeck coefficient increases with temperature throughout the measured temperature range for all compositions. The maximum Seebeck coefficient (200 μV K−1 is observed for x=0.5 at 825 K, and this composition may be optimal for high-temperature thermoelectric applications.

  12. Highly Stable Porous Covalent Triazine-Piperazine Linked Nanoflower as a Feasible Adsorbent for Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan Kumar

    2016-02-11

    Here, we report a porous covalent triazine-piperazine linked polymer (CTPP) featuring 3D nanoflower morphology and enhanced capture/removal of CO2, CH4 from air (N2), essential to control greenhouse gas emission and natural gas upgrading. 13C solid-state NMR and FTIR analyses and CHN and X-ray photoelectron spectroscopy (XPS) elemental analyses confirmed the integration of triazine and piperazine components in the network. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) analyses revealed a relatively uniform particle size of approximately 400 to 500 nm with 3D nanoflower microstructure, which was formed by the self-assembly of interwoven and slight bent nanoflake components. The material exhibited outstanding chemical robustness under acidic and basic medium and high thermal stability up to 773 K. The CTPP possess high surface area (779 m2/g) and single-component gas adsorption study exhibited enhanced CO2 and CH4 uptake of 3.48 mmol/g, 1.09 mmol/g, respectively at 273 K, 1 bar; coupled with high sorption selectivities for CO2/N2 and CH4/N2 of 128 and 17, respectively. The enriched Lewis basicity of the CTPP favors the interaction with CO2, which results in an enhanced CO2 adsorption capacity and high CO2/N2 selectivity. The binary mixture breakthrough study for the flue gas composition at 298 K showed a high CO2/N2 selectivity of 82. CO2 heats of adsorption for the CTPP (34 kJ mol−1) were realized at the borderline between strong physisorption and weak chemisorption (QstCO2; 25−50 kJ mol−1) and low Qst value for N2 (22.09 kJ mol−1), providing the ultimate validation for the high selectivity of CO2 over N2.

  13. Impact of elevated levels of atmospheric CO2 and herbivory on flavonoids of soybean (Glycine max Linnaeus).

    Science.gov (United States)

    O'Neill, Bridget F; Zangerl, Arthur R; Dermody, Orla; Bilgin, Damla D; Casteel, Clare L; Zavala, Jorge A; DeLucia, Evan H; Berenbaum, May R

    2010-01-01

    Atmospheric levels of carbon dioxide (CO2) have been increasing steadily over the last century. Plants grown under elevated CO2 conditions experience physiological changes, particularly in phytochemical content, that can influence their suitability as food for insects. Flavonoids are important plant defense compounds and antioxidants that can have a large effect on leaf palatability and herbivore longevity. In this study, flavonoid content was examined in foliage of soybean (Glycine max Linnaeus) grown under ambient and elevated levels of CO2 and subjected to damage by herbivores in three feeding guilds: leaf skeletonizer (Popillia japonica Newman), leaf chewer (Vanessa cardui Linnaeus), and phloem feeder (Aphis glycines Matsumura). Flavonoid content also was examined in foliage of soybean grown under ambient and elevated levels of O3 and subjected to damage by the leaf skeletonizer P. japonica. The presence of the isoflavones genistein and daidzein and the flavonols quercetin and kaempferol was confirmed in all plants examined, as were their glycosides. All compounds significantly increased in concentration as the growing season progressed. Concentrations of quercetin glycosides were higher in plants grown under elevated levels of CO2. The majority of compounds in foliage were induced in response to leaf skeletonization damage but remained unchanged in response to non-skeletonizing feeding or phloem-feeding. Most compounds increased in concentration in plants grown under elevated levels of O3. Insects feeding on G. max foliage growing under elevated levels of CO2 may derive additional antioxidant benefits from their host plants as a consequence of the change in ratios of flavonoid classes. This nutritional benefit could lead to increased herbivore longevity and increased damage to soybean (and perhaps other crop plants) in the future.

  14. Trajectory study of supercollision relaxation in highly vibrationally excited pyrazine and CO2.

    Science.gov (United States)

    Li, Ziman; Sansom, Rebecca; Bonella, Sara; Coker, David F; Mullin, Amy S

    2005-09-01

    Classical trajectory calculations were performed to simulate state-resolved energy transfer experiments of highly vibrationally excited pyrazine (E(vib) = 37,900 cm(-1)) and CO(2), which were conducted using a high-resolution transient infrared absorption spectrometer. The goal here is to use classical trajectories to simulate the supercollision energy transfer pathway wherein large amounts of energy are transferred in single collisions in order to compare with experimental results. In the trajectory calculations, Newton's laws of motion are used for the molecular motion, isolated molecules are treated as collections of harmonic oscillators, and intermolecular potentials are formed by pairwise Lennard-Jones potentials. The calculations qualitatively reproduce the observed energy partitioning in the scattered CO(2) molecules and show that the relative partitioning between bath rotation and translation is dependent on the moment of inertia of the bath molecule. The simulations show that the low-frequency modes of the vibrationally excited pyrazine contribute most to the strong collisions. The majority of collisions lead to small DeltaE values and primarily involve single encounters between the energy donor and acceptor. The large DeltaE exchanges result from both single impulsive encounters and chattering collisions that involve multiple encounters.

  15. CO2LD: An innovation educational project for High Degree Professional Training in Refrigeration

    Directory of Open Access Journals (Sweden)

    Ramon Cabello Lopez

    2013-12-01

    Full Text Available Refrigeration is one of the technology sectors which has suffered most changes in the last twenty years, because of the negative impact of the fluids used in the refrigeration cycles, the refrigerants, due to their impact in the ozone layer and the promotion of the global warming. Due to the negative impacts of the fluids, the European Union has established several directives to restrict the use of refrigerant fluids, causing the need of adaptation of the sector to the new regulations. The adaptation of the refrigeration sector to the new regulations must be done by all agents involved, included the training and education of the future refrigeration technicians. To allow this, the project CO2LD has been developed to introduce the future technology in the High Degree Professional Training in Refrigeration. The objective of the project consisted on introducing more efficient and more sustainable refrigeration systems, R134a/CO2 cascade cycles, in the studies of High Degree Professional Training in Refrigeration, and create a collaborative framework among students, secondary-schools, refrigeration technicians, refrigeration companies and the University to facilitate the know-how transfer. This paper presents the objectives of the project, describes its development and analyses the main conclusions of it.

  16. High magnetic field study of HoBaCo2O5.5 and GdBaCo2O5.5 layered cobaltites: the effect of rare-earth size

    International Nuclear Information System (INIS)

    Frontera, C.; Respaud, M.; Garcia-Munoz, J.L.; Llobet, A.; Carrillo, A.E.; Caneiro, A.; Broto, J.M.

    2004-01-01

    By means of high-pulsed magnetic field up to μ 0 H=32 T we have studied HoBaCo 2 O 5+δ (δ=0.52(1)). The high-field M(H) integrated curves evidence a magnetic field-induced phase transition visible from about T=75 to 275 K. The obtained results are compared with the field-induced transition found for GdBaCo 2 O 5+δ (with δ=0.54(2)). The jump of the magnetization at the field-induced transition is independent of the rare earth at this level of oxygen content. In contrast, we have observed larger values of the critical field, and that the transition persists up to higher temperature, when reducing the rare-earth size. This indicates that the low-temperature antiferromagnetic phase becomes more stable when the size of the rare earth is reduced

  17. A high precision mass spectrometry method for measuring O2/N2 ratios and CO2 concentrations in air

    International Nuclear Information System (INIS)

    Marca, A.D.; Dennis, P.F.; Etchells, A.

    2002-01-01

    A full, detailed understanding of the global carbon budget is needed for robust modelling of global climate and environmental change. Since the industrial revolution the carbon cycle has been shifted from a steady state in which removal of CO 2 from the atmosphere through photosynthesis is balanced by its addition through respiration. Currently increased respiration due to deforestation, modern agricultural practises and the burning of fossil fuels dominates photosynthesis resulting in modern atmospheric CO 2 concentrations some 32% higher than the year 1800 levels. However, the CO 2 concentration rises are lower than expected from known fossil fuel combustion inventories. A significant proportion of the excess CO 2 is taken up by the oceans, however a missing carbon sink must still be invoked to account for the difference between measured and expected CO 2 rises. A global greening as a result of increased photosynthesis is required to close the circle

  18. Modematic: a fast laser beam analyzing system for high power CO2-laser beams

    Science.gov (United States)

    Olsen, Flemming O.; Ulrich, Dan

    2003-03-01

    The performance of an industrial laser is very much depending upon the characteristics of the laser beam. The ISO standards 11146 and 11154 describing test methods for laser beam parameters have been approved. To implement these methods in industry is difficult and especially for the infrared laser sources, such as the CO2-laser, the availabl analyzing systems are slow, difficult to apply and having limited reliability due to the nature of the detection methods. In an EUREKA-project the goal was defined to develop a laser beam analyzing system dedicated to high power CO2-lasers, which could fulfill the demands for an entire analyzing system, automating the time consuming pre-alignment and beam conditioning work required before a beam mode analyses, automating the analyzing sequences and data analysis required to determine the laser beam caustics and last but not least to deliver reliable close to real time data to the operator. The results of this project work will be described in this paper. The research project has led to the development of the Modematic laser beam analyzer, which is ready for the market.

  19. Theoretical And Experimental Investigations On The Plasma Of A CO2 High Power Laser

    Science.gov (United States)

    Abel, W.; Wallter, B.

    1984-03-01

    The CO2 high power laser is increasingly used in material processing. This application of the laser has to meet some requirements: at one hand the laser is a tool free of wastage, but at the other hand is to guarantee that the properties of that tool are constant in time. Therefore power, geometry and mode of the beam have to be stable over long intervalls, even if the laser is used in rough industrial environment. Otherwise laser material processing would not be competitive. The beam quality is affected by all components of the laser - by the CO2 plasma and its IR - amplification, by the resonator which at last generates the beam by optical feedback, and also by the electric power supply whose effects on the plasma may be measured at the laser beam. A transversal flow laser has been developed at the Technical University of Vienna in cooperation with VOest-Alpine AG, Linz (Austria). This laser produces 1 kW of beam power with unfolded resonator. It was subject to investigations presented in this paper.

  20. U.S. regional greenhouse gas emissions analysis comparing highly resolved vehicle miles traveled and CO2 emissions: mitigation implications and their effect on atmospheric measurements

    Science.gov (United States)

    Mendoza, D. L.; Gurney, K. R.

    2010-12-01

    Carbon dioxide (CO2) is the most abundant anthropogenic greenhouse gas and projections of fossil fuel energy demand show CO2 concentrations increasing indefinitely into the future. After electricity production, the transportation sector is the second largest CO2 emitting economic sector in the United States, accounting for 32.3% of the total U.S. emissions in 2002. Over 80% of the transport sector is composed of onroad emissions, with the remainder shared by the nonroad, aircraft, railroad, and commercial marine vessel transportation. In order to construct effective mitigation policy for the onroad transportation sector and more accurately predict CO2 emissions for use in transport models and atmospheric measurements, analysis must incorporate the three components that determine the CO2 onroad transport emissions: vehicle fleet composition, average speed of travel, and emissions regulation strategies. Studies to date, however, have either focused on one of these three components, have been only completed at the national scale, or have not explicitly represented CO2 emissions instead relying on the use of vehicle miles traveled (VMT) as an emissions proxy. National-level projections of VMT growth is not sufficient to highlight regional differences in CO2 emissions growth due to the heterogeneity of vehicle fleet and each state’s road network which determines the speed of travel of vehicles. We examine how an analysis based on direct CO2 emissions and an analysis based on VMT differ in terms of their emissions and mitigation implications highlighting potential biases introduced by the VMT-based approach. This analysis is performed at the US state level and results are disaggregated by road and vehicle classification. We utilize the results of the Vulcan fossil fuel CO2 emissions inventory which quantified emissions for the year 2002 across all economic sectors in the US at high resolution. We perform this comparison by fuel type,12 road types, and 12 vehicle types

  1. High-pressure phase diagrams of liquid CO2 and N2

    Science.gov (United States)

    Boates, Brian; Bonev, Stanimir

    2011-06-01

    The phase diagrams of liquid CO2 and N2 have been investigated using first-principles theory. Both materials exhibit transitions to conducting liquids at high temperatures (T) and relatively modest pressures (P). Furthermore, both liquids undergo polymerization phase transitions at pressures comparable to their solid counterparts. The liquid phase diagrams have been divided into several regimes through a detailed analysis of changes in bonding, as well as structural and electronic properties for pressures and temperatures up to 200 GPa and 10 000 K, respectively. Similarities and differences between the high- P and T behavior of these fluids will be discussed. Calculations of the Hugoniot are in excellent agreement with available experimental data. Work supported by NSERC, LLNL, and the Killam Trusts. Prepared by LLNL under Contract DE-AC52-07NA27344.

  2. High Efficiency Low Cost CO2 Compression Using Supersonic Shock Wave Technology

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J; Aarnio, M; Grosvenor, A; Taylor, D; Bucher, J

    2010-12-31

    Development and testing results from a supersonic compressor are presented. The compressor achieved record pressure ratio for a fully-supersonic stage and successfully demonstrated the technology potential. Several tasks were performed in compliance with the DOE award objectives. A high-pressure ratio compressor was retrofitted to improve rotordynamics behavior and successfully tested. An outside review panel confirmed test results and design approach. A computational fluid dynamics code used to analyze the Ramgen supersonic flowpath was extensively and successfully modified to improve use on high-performance computing platforms. A comprehensive R&D implementation plan was developed and used to lay the groundwork for a future full-scale compressor demonstration. Conceptual design for a CO2 demonstration compressor was developed and reviewed.

  3. High-pressure vapor-liquid equilibrium data for CO2-orange peel oil

    Directory of Open Access Journals (Sweden)

    G.R. Stuart

    2000-06-01

    Full Text Available Recently, there has been a growing interest in fractionating orange peel oil by the use of supercritical carbon dioxide (SCCO2. However, progress in this area has been hindered by the lack of more comprehensive work concerning the phase equilibrium behavior of the SCCO2-orange peel oil system. In this context, the aim of this work is to provide new phase equilibrium data for this system over a wide range of temperatures and pressures, permitting the construction of coexistence PT-xy curves as well as the P-T diagram. The experiments were performed in a high-pressure variable-volume view cell in the temperature range of 50-70ºC from 70 to 135 atm and in the CO2 mass fraction composition range of 0.35-0.98. Based on the experimental phase equilibrium results, appropriate operating conditions can be set for high-pressure fractionation purposes.

  4. Hierarchical CuCo2O4 nanobelts as a supercapacitor electrode with high areal and specific capacitance

    International Nuclear Information System (INIS)

    Vijayakumar, Subbukalai; Lee, Seong-Hun; Ryu, Kwang-Sun

    2015-01-01

    Highlights: • First time we report the synthesis of CuCo 2 O 4 nanobelts using hydrothermal method. • The spinel CuCo 2 O 4 nanobelts exhibit maximum areal capacitance of 2.42 F cm −2 . • After 1800 cycles, 127% of the initial specific capacitance was retained. - Abstract: One dimensional hierarchical CuCo 2 O 4 nanobelt like architecture was synthesized via hydrothermal method. The synthesized nanomaterial was characterized using X-ray diffraction (XRD) analysis, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The TEM image clearly shows the nanobelt like architecture of CuCo 2 O 4 . The supercapacitor properties of CuCo 2 O 4 nanobelts electrode were tested using cyclic voltammetry, charge-discharge and electrochemical impedance spectroscopy. The spinel CuCo 2 O 4 nanobelts exhibit maximum areal and specific capacitance of 2.42 F cm −2 (809 F g −1 ). After 1800 continuous charge-discharge cycles, 127% of the initial capacitance was retained. This superior electrochemical supercapacitor property is mainly due to increased surface area and ion transport of nanobelt like architecture. The charge transfer resistance (R ct ) value of CuCo 2 O 4 nanobelt electrode is 3.85 Ω. This high capacitance and cyclic stability demonstrate that the prepared CuCo 2 O 4 nanobelts are a promising candidate for supercapacitors.

  5. Natural high pCO2 increases autotrophy in Anemonia viridis (Anthozoa) as revealed from stable isotope (C, N) analysis.

    Science.gov (United States)

    Horwitz, Rael; Borell, Esther M; Yam, Ruth; Shemesh, Aldo; Fine, Maoz

    2015-03-05

    Contemporary cnidarian-algae symbioses are challenged by increasing CO2 concentrations (ocean warming and acidification) affecting organisms' biological performance. We examined the natural variability of carbon and nitrogen isotopes in the symbiotic sea anemone Anemonia viridis to investigate dietary shifts (autotrophy/heterotrophy) along a natural pCO2 gradient at the island of Vulcano, Italy. δ(13)C values for both algal symbionts (Symbiodinium) and host tissue of A. viridis became significantly lighter with increasing seawater pCO2. Together with a decrease in the difference between δ(13)C values of both fractions at the higher pCO2 sites, these results indicate there is a greater net autotrophic input to the A. viridis carbon budget under high pCO2 conditions. δ(15)N values and C/N ratios did not change in Symbiodinium and host tissue along the pCO2 gradient. Additional physiological parameters revealed anemone protein and Symbiodinium chlorophyll a remained unaltered among sites. Symbiodinium density was similar among sites yet their mitotic index increased in anemones under elevated pCO2. Overall, our findings show that A. viridis is characterized by a higher autotrophic/heterotrophic ratio as pCO2 increases. The unique trophic flexibility of this species may give it a competitive advantage and enable its potential acclimation and ecological success in the future under increased ocean acidification.

  6. Capillary pressure and saturation relations for supercritical CO2 and brine in sand: High-pressure Pc(Sw) controller/meter measurements and capillary scaling predictions

    Science.gov (United States)

    Tokunaga, Tetsu K.; Wan, Jiamin; Jung, Jong-Won; Kim, Tae Wook; Kim, Yongman; Dong, Wenming

    2013-08-01

    In geologic carbon sequestration, reliable predictions of CO2 storage require understanding the capillary behavior of supercritical (sc) CO2. Given the limited availability of measurements of the capillary pressure (Pc) dependence on water saturation (Sw) with scCO2 as the displacing fluid, simulations of CO2 sequestration commonly rely on modifying more familiar air/H2O and oil/H2O Pc(Sw) relations, adjusted to account for differences in interfacial tensions. In order to test such capillary scaling-based predictions, we developed a high-pressure Pc(Sw) controller/meter, allowing accurate Pc and Sw measurements. Drainage and imbibition processes were measured on quartz sand with scCO2-brine at pressures of 8.5 and 12.0 MPa (45°C), and air-brine at 21°C and 0.1 MPa. Drainage and rewetting at intermediate Sw levels shifted to Pc values that were from 30% to 90% lower than predicted based on interfacial tension changes. Augmenting interfacial tension-based predictions with differences in independently measured contact angles from different sources led to more similar scaled Pc(Sw) relations but still did not converge onto universal drainage and imbibition curves. Equilibrium capillary trapping of the nonwetting phases was determined for Pc = 0 during rewetting. The capillary-trapped volumes for scCO2 were significantly greater than for air. Given that the experiments were all conducted on a system with well-defined pore geometry (homogeneous sand), and that scCO2-brine interfacial tensions are fairly well constrained, we conclude that the observed deviations from scaling predictions resulted from scCO2-induced decreased wettability. Wettability alteration by scCO2 makes predicting hydraulic behavior more challenging than for less reactive fluids.

  7. Poly(ionic liquid)/Ionic Liquid Ion-Gels with High "Free" Ionic Liquid Content: Platform Membrane Materials for CO2/Light Gas Separations.

    Science.gov (United States)

    Cowan, Matthew G; Gin, Douglas L; Noble, Richard D

    2016-04-19

    The recycling or sequestration of carbon dioxide (CO2) from the waste gas of fossil-fuel power plants is widely acknowledged as one of the most realistic strategies for delaying or avoiding the severest environmental, economic, political, and social consequences that will result from global climate change and ocean acidification. For context, in 2013 coal and natural gas power plants accounted for roughly 31% of total U.S. CO2 emissions. Recycling or sequestering this CO2 would reduce U.S. emissions by ca. 1800 million metric tons-easily meeting the U.S.'s currently stated CO2 reduction targets of ca. 17% relative to 2005 levels by 2020. This situation is similar for many developed and developing nations, many of which officially target a 20% reduction relative to 1990 baseline levels by 2020. To make CO2 recycling or sequestration processes technologically and economically viable, the CO2 must first be separated from the rest of the waste gas mixture-which is comprised mostly of nitrogen gas and water (ca. 85%). Of the many potential separation technologies available, membrane technology is particularly attractive due to its low energy operating cost, low maintenance, smaller equipment footprint, and relatively facile retrofit integration with existing power plant designs. From a techno-economic standpoint, the separation of CO2 from flue gas requires membranes that can process extremely high amounts of CO2 over a short time period, a property defined as the membrane "permeance". In contrast, the membrane's CO2/N2 selectivity has only a minor effect on the overall cost of some separation processes once a threshold permeability selectivity of ca. 20 is reached. Given the above criteria, the critical properties when developing membrane materials for postcombustion CO2 separation are CO2 permeability (i.e., the rate of CO2 transport normalized to the material thickness), a reasonable CO2/N2 selectivity (≥20), and the ability to be processed into defect-free thin

  8. Core/shell structure NiCo2O4@MnCo2O4 nanofibers fabricated by different temperatures for high-performance supercapacitors

    Science.gov (United States)

    Wang, Qing; Qin, Xuefeng; Jiang, Pengcheng; Dai, Jianfeng; Li, Weixue; Gao, Haoran

    2018-03-01

    Core/shell structure NiCo2O4@MnCo2O4 nanofibers (NiCo2O4@MnCo2O4 NFs) were prepared by a facile co-electrospinning method and heat treatment. The composites annealed at 500 °C have a complete, continuously obvious core/shell structure, and clear interface of composites with good morphology, while annealed at 600 °C were stacked on each other and were unable to sustain three-dimensional network structures and 700 °C calcination have completely lost one-dimensional structure. The core NiCo2O4 is about 70 nm in diameter and the MnCo2O4 shell behaves a thickness about 60 nm. When investigated as an electrode material for supercapacitors, the NiCo2O4@MnCo2O4 NFs annealed at 500 °C exihibited the specific capacitance of 463 F g-1 (0.926 F cm-2) at 1 A g-1, higher than that annealed at 600 °C 362 F g-1, 1 A g-1 (0.724 F cm-2, 1 A g-1) and 700 °C 283 F g-1, 1 A g-1 (0.566 F cm-2, 1 A g-1). These results suggest that core/shell NiCo2O4@MnCo2O4 NFs annealed at 500 °C have formed a good morphology with continuously complete core/shell structure which lead to good properties would be potential electrodes for supercapacitors.

  9. Dissociation of NH3 and NH2D by high power CO2 laser radiation

    International Nuclear Information System (INIS)

    Jacobs, R.R.

    1976-08-01

    Multiquantum dissociation of polyatomics using intense CO 2 lasers resulting in isotopic enrichment has been demonstrated for several molecules. In this presentation, the possibility of selective dissociation of NH 3 and NH 2 D by high power laser radiation at 10 μm will be considered. Relevant work performed at the Lawrence Livermore Laboratory and elsewhere will be summarized. In this review, attention will be given to four distinct mechanisms that can play varying degrees of importance in such investigations. Discussion will deal with the usefulness of two-resonant-frequency molecular excitation, the role of buffer gases, and the need to monitor the yields into the ground and excited electronic states of the dissociated fragments

  10. Hierarchical NiCo2 O4 nanosheets grown on Ni nanofoam as high-performance electrodes for supercapacitors.

    Science.gov (United States)

    Gao, Guoxin; Wu, Hao Bin; Ding, Shujiang; Liu, Li-Min; Lou, Xiong Wen David

    2015-02-18

    A high-performance electrode for supercapacitors is designed and synthesized by growing electroactive NiCo2 O4 nanosheets on conductive Ni nanofoam. Because of the structural advantages, the as-prepared Ni@NiCo2 O4 hybrid nanostructure exhibits significantly improved electrochemical performance with high capacitance, excellent rate capability, and good cycling stability. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Exploring the MIS M2 glaciation occurring during a warm and high atmospheric CO2 Pliocene background climate

    Science.gov (United States)

    Tan, Ning; Ramstein, Gilles; Dumas, Christophe; Contoux, Camille; Ladant, Jean-Baptiste; Sepulchre, Pierre; Zhang, Zhongshi; De Schepper, Stijn

    2017-08-01

    Prior to the Northern Hemisphere glaciation around ∼2.7 Ma, a large global glaciation corresponding to a 20 to 60 m sea-level drop occurred during Marine Isotope Stage (MIS) M2 (3.312-3.264 Ma), interrupted the period of global warmth and high CO2 concentration (350-450 ppmv) of the mid Piacenzian. Unlike the late Quaternary glaciations, the M2 glaciation only lasted 50 kyrs and occurred under uncertain CO2 concentration (220-390 ppmv). The mechanisms causing the onset and termination of the M2 glaciation remain enigmatic, but a recent geological hypothesis suggests that the re-opening and closing of the shallow Central American Seaway (CAS) might have played a key role. In this article, thanks to a series of climate simulations carried out using a fully coupled Atmosphere Ocean General Circulation Model (GCM) and a dynamic ice sheet model, we show that re-opening of the shallow CAS helps precondition the low-latitude oceanic circulation and affects the related northward energy transport, but cannot alone explain the onset of the M2 glaciation. The presence of a shallow open CAS, together with favourable orbital parameters, 220 ppmv of CO2 concentration, and the related vegetation and ice sheet feedback, led to a global ice sheet build-up producing a global sea-level drop in the lowest range of proxy-derived estimates. More importantly, our results show that the simulated closure of the CAS has a negligible impact on the NH ice sheet melt and cannot explain the MIS M2 termination.

  12. High-frequency pressure variations in the vicinity of a surface CO2 flux chamber

    Science.gov (United States)

    Eugene S. Takle; James R. Brandle; R. A. Schmidt; Rick Garcia; Irina V. Litvina; William J. Massman; Xinhua Zhou; Geoffrey Doyle; Charles W. Rice

    2003-01-01

    We report measurements of 2Hz pressure fluctuations at and below the soil surface in the vicinity of a surface-based CO2 flux chamber. These measurements were part of a field experiment to examine the possible role of pressure pumping due to atmospheric pressure fluctuations on measurements of surface fluxes of CO2. Under the moderate wind speeds, warm temperatures,...

  13. Pulse propagation properties in high-power CO2 laser system for laser fusion

    International Nuclear Information System (INIS)

    Daido, H.; Inoue, M.; Fujita, H.; Matoba, M.; Nakai, S.

    1981-01-01

    The simulation results of nonlinear propagation properties in the CO 2 laser system using a simulation model of the SF 6 saturable absorbers and the CO 2 laser amplifiers agree well with the experimental results. The technical problems of the simultaneous irradiation of the multi-beams to a target are also discussed. (author)

  14. Modelling of accidental releases from a high pressure CO2 pipelines

    NARCIS (Netherlands)

    Molag, M.; Dam, C.

    2011-01-01

    In the near future large quantities of CO2 will be transported over a large distance from Carbon dioxide Capture plants to onshore and off-shore underground Storage (CCS) sites. The risk assessments for the existing CO2 pipelines show distances to harmful threshold concentrations from 1 to 7.2 km.

  15. In situ X-ray ptychography imaging of high-temperature CO2 acceptor particle agglomerates

    DEFF Research Database (Denmark)

    Høydalsvik, Kristin; Fløystad, Jostein Bø; Zhao, Tiejun

    2014-01-01

    be used for in situ phase contrast imaging in structure studies at atmospheric pressure and elevated temperatures. Lithium zirconate, a candidate CO2 capture material, was studied at a pressure of one atmosphere in air and in CO2, at temperatures exceeding 600 °C. Images with a spatial resolution better...

  16. The association between use of metformin and change in serum CO_2 level after administration of contrast medium

    International Nuclear Information System (INIS)

    Kim, S.K.; Jung, J.; Jung, J.H.; Kim, K.Y.; Baek, J.-H.; Hahm, J.R.

    2016-01-01

    Aim: To evaluate the changes in serum creatinine and total CO_2 levels in patients receiving metformin during administration of contrast medium. Materials and methods: Patient records from January 2012 to December 2012 after the administration of contrast medium were reviewed retrospectively. A total of 924 patients were included for the final analysis. Of them, 105 received metformin during contrast medium administration, 112 were taking other oral hypoglycaemic agents, and 707 patients were not diabetic (controls). Results: No significant change in total CO_2 levels was detected (p=0.678). Metabolic acidosis was present in 33 (31.4%) metformin users, 31 (28.6%) other oral hypoglycaemic agent users, and 153 (21.6%) control patients. In the present logistic regression analysis, age, baseline levels of creatinine, and total CO_2 levels were associated with metabolic acidosis after contrast medium exposure. Conclusion: These data indicate the presence of a coexisting risk factor, other than metformin use, associated with metabolic acidosis after contrast medium exposure. No relationship was found between the use of metformin and metabolic acidosis during contrast medium exposure. - Highlights: • The use of metformin was not associated with metabolic acidosis after contrast exposure. • The coexisting risk factors for metabolic acidosis were present in patient with metabolic acidosis after contrast exposure. • There is a need to consider the maintenance of metformin during a CT scan in patients with a low risk for lactic acidosis.

  17. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.

    2015-01-01

    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

  18. High-frequency productivity estimates for a lake from free-water CO2 concentration measurements

    Science.gov (United States)

    Provenzale, Maria; Ojala, Anne; Heiskanen, Jouni; Erkkilä, Kukka-Maaria; Mammarella, Ivan; Hari, Pertti; Vesala, Timo

    2018-04-01

    Lakes are important actors in biogeochemical cycles and a powerful natural source of CO2. However, they are not yet fully integrated in carbon global budgets, and the carbon cycle in the water is still poorly understood. In freshwater ecosystems, productivity studies have usually been carried out with traditional methods (bottle incubations, 14C technique), which are imprecise and have a poor temporal resolution. Consequently, our ability to quantify and predict the net ecosystem productivity (NEP) is limited: the estimates are prone to errors and the NEP cannot be parameterised from environmental variables. Here we expand the testing of a free-water method based on the direct measurement of the CO2 concentration in the water. The approach was first proposed in 2008, but was tested on a very short data set (3 days) under specific conditions (autumn turnover); despite showing promising results, this method has been neglected by the scientific community. We tested the method under different conditions (summer stratification, typical summer conditions for boreal dark-water lakes) and on a much longer data set (40 days), and quantitatively validated it comparing our data and productivity models. We were able to evaluate the NEP with a high temporal resolution (minutes) and found a very good agreement (R2 ≥ 0.71) with the models. We also estimated the parameters of the productivity-irradiance (PI) curves that allow the calculation of the NEP from irradiance and water temperature. Overall, our work shows that the approach is suitable for productivity studies under a wider range of conditions, and is an important step towards developing this method so that it becomes more widely used.

  19. High-frequency productivity estimates for a lake from free-water CO2 concentration measurements

    Directory of Open Access Journals (Sweden)

    M. Provenzale

    2018-04-01

    Full Text Available Lakes are important actors in biogeochemical cycles and a powerful natural source of CO2. However, they are not yet fully integrated in carbon global budgets, and the carbon cycle in the water is still poorly understood. In freshwater ecosystems, productivity studies have usually been carried out with traditional methods (bottle incubations, 14C technique, which are imprecise and have a poor temporal resolution. Consequently, our ability to quantify and predict the net ecosystem productivity (NEP is limited: the estimates are prone to errors and the NEP cannot be parameterised from environmental variables. Here we expand the testing of a free-water method based on the direct measurement of the CO2 concentration in the water. The approach was first proposed in 2008, but was tested on a very short data set (3 days under specific conditions (autumn turnover; despite showing promising results, this method has been neglected by the scientific community. We tested the method under different conditions (summer stratification, typical summer conditions for boreal dark-water lakes and on a much longer data set (40 days, and quantitatively validated it comparing our data and productivity models. We were able to evaluate the NEP with a high temporal resolution (minutes and found a very good agreement (R2 ≥ 0.71 with the models. We also estimated the parameters of the productivity–irradiance (PI curves that allow the calculation of the NEP from irradiance and water temperature. Overall, our work shows that the approach is suitable for productivity studies under a wider range of conditions, and is an important step towards developing this method so that it becomes more widely used.

  20. Transcriptomics reveal transgenerational effects in purple sea urchin embryos: Adult acclimation to upwelling conditions alters the response of their progeny to differential pCO2 levels.

    Science.gov (United States)

    Wong, Juliet M; Johnson, Kevin M; Kelly, Morgan W; Hofmann, Gretchen E

    2018-03-01

    Understanding the mechanisms with which organisms can respond to a rapidly changing ocean is an important research priority in marine sciences, especially in the light of recent predictions regarding the pace of ocean change in the coming decades. Transgenerational effects, in which the experience of the parental generation can shape the phenotype of their offspring, may serve as such a mechanism. In this study, adult purple sea urchins, Strongylocentrotus purpuratus, were conditioned to regionally and ecologically relevant pCO 2 levels and temperatures representative of upwelling (colder temperature and high pCO 2 ) and nonupwelling (average temperature and low pCO 2 ) conditions typical of coastal upwelling regions in the California Current System. Following 4.5 months of conditioning, adults were spawned and offspring were raised under either high or low pCO 2 levels, to examine the role of maternal effects. Using RNA-seq and comparative transcriptomics, our results indicate that differential conditioning of the adults had an effect on the gene expression patterns of the progeny during the gastrula stage of early development. For example, maternal conditioning under upwelling conditions intensified the transcriptomic response of the progeny when they were raised under high versus low pCO 2 conditions. Additionally, mothers that experienced upwelling conditions produced larger progeny. The overall findings of this study are complex, but do suggest that transgenerational plasticity in situ could act as an important mechanism by which populations might keep pace with rapid environmental change. © 2018 John Wiley & Sons Ltd.

  1. Flexible and High Performance Supercapacitors Based on NiCo2O4for Wide Temperature Range Applications

    Science.gov (United States)

    Gupta, Ram K.; Candler, John; Palchoudhury, Soubantika; Ramasamy, Karthik; Gupta, Bipin Kumar

    2015-10-01

    Binder free nanostructured NiCo2O4 were grown using a facile hydrothermal technique. X-ray diffraction patterns confirmed the phase purity of NiCo2O4. The surface morphology and microstructure of the NiCo2O4 analyzed by scanning electron microscopy (SEM) showed flower-like morphology composed of needle-like structures. The potential application of binder free NiCo2O4 as an electrode for supercapacitor devices was investigated using electrochemical methods. The cyclic voltammograms of NiCo2O4 electrode using alkaline aqueous electrolytes showed the presence of redox peaks suggesting pseudocapacitance behavior. Quasi-solid state supercapacitor device fabricated by sandwiching two NiCo2O4 electrodes and separating them by ion transporting layer. The performance of the device was tested using cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The device showed excellent flexibility and cyclic stability. The temperature dependent charge storage capacity was measured for their variable temperature applications. Specific capacitance of the device was enhanced by ~150% on raising the temperature from 20 to 60 °C. Hence, the results suggest that NiCo2O4 grown under these conditions could be a suitable material for high performance supercapacitor devices that can be operated at variable temperatures.

  2. Constructing robust and highly-selective hydrogel membranes by bioadhesion-inspired method for CO 2 separation

    KAUST Repository

    Wu, Yingzhen

    2018-06-01

    Water-swollen hydrogel membranes are good candidates for CO2 separations due to the favorable solubility of CO2 in water. However, the excessive amount of water often causes the poor mechanical property and low selectivity. Herein, we propose a bioadhesion-inspired method to construct robust and high-performance CO2 separation membranes via in situ generation of polydopamine (PDA) nanoaggregates within poly (vinyl alcohol) (PVA) matrix. PDA nanoaggregates entangled with PVA chains and formed hydrogen bonding with hydroxyl groups from PVA chains. Physical cross-linking occurred between PVA chains and PDA nanoaggregates. Compared with the PVA membrane, the PVA-PDA hybrid membrane with the dopamine content of 0.5mol% exhibited a 1.7-fold increase in tensile strength and a 2.2-fold increase in the tensile modulus. The membranes were used for CO2/CH4 separation. The physical cross-linking resulted in a PVA chain rigidification region around PDA nanoaggregates, which hindered the penetration of larger-size gas molecules and thus enhancing the CO2/CH4 selectivity. Moreover, the abundant amine groups from PDA nanoaggregates could facilitate CO2 transport. The optimized hybrid hydrogel membrane exhibited CO2/CH4 selectivity of 43.2, which was 43.85% higher than that of the PVA membrane. The bioadhesion-inspired method opens up new opportunities to exploit the potential application of hydrogel membranes.

  3. Los Angeles megacity: a high-resolution land–atmosphere modelling system for urban CO2 emissions

    Directory of Open Access Journals (Sweden)

    S. Feng

    2016-07-01

    Full Text Available Megacities are major sources of anthropogenic fossil fuel CO2 (FFCO2 emissions. The spatial extents of these large urban systems cover areas of 10 000 km2 or more with complex topography and changing landscapes. We present a high-resolution land–atmosphere modelling system for urban CO2 emissions over the Los Angeles (LA megacity area. The Weather Research and Forecasting (WRF-Chem model was coupled to a very high-resolution FFCO2 emission product, Hestia-LA, to simulate atmospheric CO2 concentrations across the LA megacity at spatial resolutions as fine as  ∼  1 km. We evaluated multiple WRF configurations, selecting one that minimized errors in wind speed, wind direction, and boundary layer height as evaluated by its performance against meteorological data collected during the CalNex-LA campaign (May–June 2010. Our results show no significant difference between moderate-resolution (4 km and high-resolution (1.3 km simulations when evaluated against surface meteorological data, but the high-resolution configurations better resolved planetary boundary layer heights and vertical gradients in the horizontal mean winds. We coupled our WRF configuration with the Vulcan 2.2 (10 km resolution and Hestia-LA (1.3 km resolution fossil fuel CO2 emission products to evaluate the impact of the spatial resolution of the CO2 emission products and the meteorological transport model on the representation of spatiotemporal variability in simulated atmospheric CO2 concentrations. We find that high spatial resolution in the fossil fuel CO2 emissions is more important than in the atmospheric model to capture CO2 concentration variability across the LA megacity. Finally, we present a novel approach that employs simultaneous correlations of the simulated atmospheric CO2 fields to qualitatively evaluate the greenhouse gas measurement network over the LA megacity. Spatial correlations in the atmospheric CO2 fields reflect the coverage of

  4. Impact of CO2 injection protocol on fluid-solid reactivity: high-pressure and temperature microfluidic experiments in limestone

    Science.gov (United States)

    Jimenez-Martinez, Joaquin; Porter, Mark; Carey, James; Guthrie, George; Viswanathan, Hari

    2017-04-01

    Geological sequestration of CO2 has been proposed in the last decades as a technology to reduce greenhouse gas emissions to the atmosphere and mitigate the global climate change. However, some questions such as the impact of the protocol of CO2 injection on the fluid-solid reactivity remain open. In our experiments, two different protocols of injection are compared at the same conditions (8.4 MPa and 45 C, and constant flow rate 0.06 ml/min): i) single phase injection, i.e., CO2-saturated brine; and ii) simultaneous injection of CO2-saturated brine and scCO2. For that purpose, we combine a unique high-pressure/temperature microfluidics experimental system, which allows reproducing geological reservoir conditions in geo-material substrates (i.e., limestone, Cisco Formation, Texas, US) and high resolution optical profilometry. Single and multiphase flow through etched fracture networks were optically recorded with a microscope, while processes of dissolution-precipitation in the etched channels were quantified by comparison of the initial and final topology of the limestone micromodels. Changes in hydraulic conductivity were quantified from pressure difference along the micromodel. The simultaneous injection of CO2-saturated brine and scCO2, reduced the brine-limestone contact area and also created a highly heterogeneous velocity field (i.e., low velocities regions or stagnation zones, and high velocity regions or preferential paths), reducing rock dissolution and enhancing calcite precipitation. The results illustrate the contrasting effects of single and multiphase flow on chemical reactivity and suggest that multiphase flow by isolating parts of the flow system can enhance CO2 mineralization.

  5. High Resolution Atmospheric Inversion of Urban CO2 Emissions During the Dormant Season of the Indianapolis Flux Experiment (INFLUX)

    Science.gov (United States)

    Lauvaux, Thomas; Miles, Natasha L.; Deng, Aijun; Richardson, Scott J.; Cambaliza, Maria O.; Davis, Kenneth J.; Gaudet, Brian; Gurney, Kevin R.; Huang, Jianhua; O'Keefe, Darragh; hide

    2016-01-01

    Urban emissions of greenhouse gases (GHG) represent more than 70% of the global fossil fuel GHG emissions. Unless mitigation strategies are successfully implemented, the increase in urban GHG emissions is almost inevitable as large metropolitan areas are projected to grow twice as fast as the world population in the coming 15 years. Monitoring these emissions becomes a critical need as their contribution to the global carbon budget increases rapidly. In this study, we developed the first comprehensive monitoring systems of CO2 emissions at high resolution using a dense network of CO2 atmospheric measurements over the city of Indianapolis. The inversion system was evaluated over a 8-month period and showed an increase compared to the Hestia CO2 emission estimate, a state-of-the-art building-level emission product, with a 20% increase in the total emissions over the area (from 4.5 to 5.7 Metric Megatons of Carbon +/- 0.23 Metric Megatons of Carbon). However, several key parameters of the inverse system need to be addressed to carefully characterize the spatial distribution of the emissions and the aggregated total emissions.We found that spatial structures in prior emission errors, mostly undetermined, affect significantly the spatial pattern in the inverse solution, as well as the carbon budget over the urban area. Several other parameters of the inversion were sufficiently constrained by additional observations such as the characterization of the GHG boundary inflow and the introduction of hourly transport model errors estimated from the meteorological assimilation system. Finally, we estimated the uncertainties associated with remaining systematic errors and undetermined parameters using an ensemble of inversions. The total CO2 emissions for the Indianapolis urban area based on the ensemble mean and quartiles are 5.26 - 5.91 Metric Megatons of Carbon, i.e. a statistically significant difference compared to the prior total emissions of 4.1 to 4.5 Metric Megatons of

  6. Fabrication and thermoelectric properties of highly textured NaCo2O4 ceramic

    International Nuclear Information System (INIS)

    Cheng Jinguang; Sui Yu; Fu Haijin; Lu Zhe; Wei Bo; Qian Zhengnan; Miao Jipeng; Liu Zhiguo; Huang Xiqiang; Zhu Ruibin; Wang Xianjie; Su Wenhui

    2006-01-01

    Highly textured NaCo 2 O 4 polycrystalline sample was fabricated by means of the cold high-pressure compacting followed by the solid-state reaction. X-ray diffraction and scanning electron microscope were employed to show that the plate-like grains within the sample are aligned along the pressing direction. The resistivity ρ and thermoelectric power S along the preferred {0 0 1} plane were measured in the whole temperature range from 15 to 973 K in air and the correlation between thermoelectric properties and texture was investigated. It was found that both ρ and S exhibit metallic behavior in the whole temperature range and the above sample exhibits lower ρ and higher S due to high texture and density. The power factor exhibits a steep rise above 400 K and reaches 761 μW m -1 K -2 at 973 K, suggesting a promising candidate for thermoelectric application at higher temperature. The change of slope in both resistivity and thermoelectric power curves at about 450 K might arise from the spin-state transition of Co ions in the CoO 2 blocks

  7. Multi-shelled ZnCo2O4 yolk-shell spheres for high-performance acetone gas sensor

    Science.gov (United States)

    Xiong, Ya; Zhu, Zongye; Ding, Degong; Lu, Wenbo; Xue, Qingzhong

    2018-06-01

    In the present study, multi-shelled ZnCo2O4 yolk-shell spheres have been successfully prepared by using carbonaceous microspheres as templates. It is found that the multi-shelled ZnCo2O4 yolk-shell spheres based sensor shows optimal sensing performances (response value of 38.2, response/recovery time of 19 s/71 s) toward 500 ppm acetone at 200 °C. In addition, this sensor exhibits a low detection limit of 0.5 ppm acetone (response value of 1.36) and a good selectivity toward hydrogen, methane, ethanol, ammonia and carbon dioxide. Furthermore, it is demonstrated that acetone gas response of multi-shelled ZnCo2O4 yolk-shell spheres is significantly better than that of ZnCo2O4 nanotubes and ZnCo2O4 nanosheets. High acetone response of the multi-shelled ZnCo2O4 yolk-shell spheres is attributed to the enhanced gas accessibility of the multi-shell morphology caused by the small crystalline size and high specific surface area while the short response/recovery time is mainly related to the rapid gas diffusion determined by the highly porous structure. Our work puts forward an exciting opportunity in designing various yolk-shelled structures for multipurpose applications.

  8. Contrasting effects of elevated CO2 on Cu and Cd uptake by different rice varieties grown on contaminated soils with two levels of metals: Implication for phytoextraction and food safety

    International Nuclear Information System (INIS)

    Li Zhongyang; Tang Shirong; Deng Xiaofang; Wang Ruigang; Song Zhengguo

    2010-01-01

    A pot experiment in six open-top chambers with two levels of CO 2 and two multi-metal contaminated soils was conducted to investigate combined effects of elevated CO 2 levels and metals (Cu and Cd) on rice. Elevated CO 2 significantly increased the total dry weight biomass of six Chinese rice by 20-108 and 32-142% for low and high levels of contaminated soils, respectively. We observed dilution/little varied phenomena in grain Cu concentration in six rice varieties grown on both contaminated soils under elevated CO 2 . We found significantly higher Cd concentrations in the parts of three rice varieties under elevated CO 2 , but lower levels for the others. Two major conclusions can be drawn from our study: (1) rice varieties with significantly increased biomass and metal uptake under elevated CO 2 exhibit greater potential for phytoextraction and (2) given expected global increases in CO 2 concentration, CO 2 -induced accumulation of metals in rice might be a component contributing to the potential health risk in the future, with Cd being a more important threat to human health than Cu.

  9. High CO2 emissions from the tropical Godavari estuary (India) associated with monsoon river discharges

    Digital Repository Service at National Institute of Oceanography (India)

    Sarma, V.V.S.S.; Kumar, N.A.; Prasad, V.R.; Venkataramana, V.; Appalanaidu, S.; Sridevi, B.; Kumar, B.S.K.; Bharati, M.D.; Subbaiah, C.V.; Acharyya, T.; Rao, G.D.; Viswanadham, R.; Gawade, L.; Manjary, D.T.; Kumar, P.P.; Rajeev, K.; Reddy, N.P.C.; Sarma, V.V.; Kumar, M.D.; Sadhuram, Y.; Murty, T.V.R.

    ). Air-water flux of CO 2 was estimated following Wanninkhof (1992) using measured wind speed. 3. Results and discussion The dam controlled freshwater discharge into the Godavari estuary was maximal in August (Fig. 2a). There was virtually... bacterioplankton. Appl. Environ. Microbiol.52,1298-1303. Lewis, E., and D.W.R. Wallace (1998). Program developed for CO2 system calculations. ORNL/CDIAC-105. Carbon dioxide information analysis center, Oak Ridge National Laboratory, U.S. Department of Energy...

  10. Explosive vaporization induced by high-power CO2-laser target interactions

    International Nuclear Information System (INIS)

    Hugenschmidt, M.; Vollrath, K.

    1976-01-01

    The interactions of high-power laser pulses with targets such as metals or dielectric materials causes a series of optical, thermal, and mechanical processes. Thereby, heating, melting, and vaporization can take place in a short time. At power densities of about 10 7 to several 10 8 W/cm 2 this can even be produced explosively. As compared to continuous ablation, this type of interaction can remove greater masses from the bulk of material. The investigations are performed by using an electron-beam preionized CO 2 -laser acting on different target materials. The energy of the laser pulses is about 30 J, the pulse-half-widths of the long-tail pulses 4 to 6 μs. Optical measurements yield some information on threshold values for these processes, for the formation and expansion of plasmas, and for the ejection of material in form of greater particles. High speed photographic techniques include a rotating mirror- and an image converter camera. Starting from shock-wave theory, gas dynamic equations (in unidimensional approximation) allow for a quantitative determination of the specific internal energies and pressures in the case of optical detonation. (orig.) [de

  11. Multicollector High Precision Resolution of Primordial Kr and Xe in Mantle CO2 Well Gases

    Science.gov (United States)

    Holland, G.; Ballentine, C.; Cassidy, M.

    2008-12-01

    Noble gas isotopes in magmatic CO2 well gases provide a unique insight into mantle volatile origin and dynamics [1-3]. Previous work has resolved mantle 20Ne/22Ne ratios consistent with a solar wind irradiated meteoritic source for mantle He and Ne [1]. This is distinct from Solar Wind values that might be expected if the primary mechanism of terrestrial mantle volatile acquisition was through the gravitational capture of solar nebula gases [see 4]. Within the CO2 well gases a primordial component has also been resolved in the non- radiogenic Xe isotopic composition [2,3]. Using multicollector mass spectrometry we have observed a 124Xe/130Xe excess of 1.85 percent over air plus/minus 0.17 percent for the least air contaminated samples. At this level of precision we are for the first time able to differentiate between a trapped meteoritic origin (average carbonaceous chondrite or Q Xe) rather than Solar Wind origin as the primordial Xe component. The well gases also contain Kr which, in the least air contaminated sample, have a correlated 86Kr/82Kr excess of 0.55 percent over air plus/minus 0.04 percent. Whilst mass dependent fractionation can theoretically produce correlated excesses in 124Xe-128Xe and 82Kr-86Kr isotopes, no fractionation from air is observed in 38Ar/36Ar [3] and the Kr excesses are in the opposite sense to that of Xe. From 136Xe excesses, Kr fission yield from Pu and U can be calculated and subtracted from the Kr isotopic signature. This fission-corrected signature is most reasonably explained as a primordial component. This is the first time that primordial Kr has ever been resolved in a terrestrial sample. The primordial Kr isotopic signature is distinct from Solar Wind Kr and is consistent with the primordial Kr also originating as a trapped component within meteorites. We are now able to demonstrate that both the light (He and Ne) and Heavy (Kr and Xe) noble gas origin in the terrestrial mantle is consistent with a trapped component during the

  12. Phase equilibrium measurements and thermodynamic modelling for the system (CO2 + ethyl palmitate + ethanol) at high pressures

    International Nuclear Information System (INIS)

    Gaschi, Priscilla S.; Mafra, Marcos R.; Ndiaye, Papa M.; Corazza, Marcos L.

    2013-01-01

    Graphical abstract: Ethyl palmitate and biodiesel comparison in a pressure–composition diagram for the systems (CO 2 + ethyl palmitate + biodiesel), at different temperatures. Highlights: ► We measured VLE, LLE, and VLLE for the system (CO 2 + ethyl palmitate + ethanol). ► The saturation pressures were obtained using a variable-volume view cell. ► Phase envelope of (CO 2 + ethyl palmitate) is different that (CO 2 + soybean oil biodiesel). ► The experimental data were modeled using PR-vdW2 and PR–WS equations of state. - Abstract: This work reports phase equilibrium measurements for the binary {CO 2 (1) + ethyl palmitate(2)} and ternary {CO 2 (1) + ethyl palmitate(2) + ethanol(3)} systems at high pressures. There is currently great interest in biodiesel production processes involving supercritical and/or pressurized solvents, such as non-catalytic supercritical biodiesel production and enzyme-catalysed biodiesel production. Also, supercritical CO 2 can offer an interesting alternative for glycerol separation in the biodiesel purification step in a water-free process. In this context, the main goal of this work was to investigate the phase behaviour of binary and ternary systems involving CO 2 , a pure constituent of biodiesel ethyl palmitate and ethanol. Experiments were carried out in a high-pressure variable-volume view cell with operating temperatures ranging from (303.15 to 353.15) K and pressures up to 21 MPa. The CO 2 mole fraction ranged from 0.5033 to 0.9913 for the binary {CO 2 (1) + ethyl palmitate(2)} system and from 0.4436 to 0.9712 for ternary system {CO 2 (1) + ethyl palmitate(2) + ethanol(3)} system with ethyl ester to ethanol molar ratios of (1:6), (1:3), and (1:1). For the systems investigated, vapour–liquid (VL), liquid–liquid (LL) and vapour–liquid–liquid (VLL) phase transitions were observed. The experimental data sets were successfully modeled using the Peng–Robinson equation of state with the classical van der Waals

  13. CO2-Tea pulse clipping using pulsed high voltage preionization for high spatial resolution I.R. Lidar systems

    Directory of Open Access Journals (Sweden)

    Gasmi Taieb

    2018-01-01

    Full Text Available An extra-cavity CO2-TEA laser pulse clipper for high spatial resolution atmospheric monitoring is presented. The clipper uses pulsed high voltageto facilitate the breakdown of the gas within the clipper cell. Complete extinction of the nitrogen tail, that degrades the range resolution of LIDARS, is obtained at pressures from 375 up to 1500 Torr for nitrogen and argon gases whereas an attenuation coefficient of almost 102 is achieved for helium. Excellent energy stability and pulse width repeatability were achieved using high voltage pre-ionized gas technique.

  14. CO2-Tea pulse clipping using pulsed high voltage preionization for high spatial resolution I.R. Lidar systems

    Science.gov (United States)

    Gasmi, Taieb

    2018-04-01

    An extra-cavity CO2-TEA laser pulse clipper for high spatial resolution atmospheric monitoring is presented. The clipper uses pulsed high voltageto facilitate the breakdown of the gas within the clipper cell. Complete extinction of the nitrogen tail, that degrades the range resolution of LIDARS, is obtained at pressures from 375 up to 1500 Torr for nitrogen and argon gases whereas an attenuation coefficient of almost 102 is achieved for helium. Excellent energy stability and pulse width repeatability were achieved using high voltage pre-ionized gas technique.

  15. Global high-resolution monthly pCO2 climatology for the coastal ocean derived from neural network interpolation

    Directory of Open Access Journals (Sweden)

    G. G. Laruelle

    2017-10-01

    Full Text Available In spite of the recent strong increase in the number of measurements of the partial pressure of CO2 in the surface ocean (pCO2, the air–sea CO2 balance of the continental shelf seas remains poorly quantified. This is a consequence of these regions remaining strongly under-sampled in both time and space and of surface pCO2 exhibiting much higher temporal and spatial variability in these regions compared to the open ocean. Here, we use a modified version of a two-step artificial neural network method (SOM-FFN; Landschützer et al., 2013 to interpolate the pCO2 data along the continental margins with a spatial resolution of 0.25° and with monthly resolution from 1998 to 2015. The most important modifications compared to the original SOM-FFN method are (i the much higher spatial resolution and (ii the inclusion of sea ice and wind speed as predictors of pCO2. The SOM-FFN is first trained with pCO2 measurements extracted from the SOCATv4 database. Then, the validity of our interpolation, in both space and time, is assessed by comparing the generated pCO2 field with independent data extracted from the LDVEO2015 database. The new coastal pCO2 product confirms a previously suggested general meridional trend of the annual mean pCO2 in all the continental shelves with high values in the tropics and dropping to values beneath those of the atmosphere at higher latitudes. The monthly resolution of our data product permits us to reveal significant differences in the seasonality of pCO2 across the ocean basins. The shelves of the western and northern Pacific, as well as the shelves in the temperate northern Atlantic, display particularly pronounced seasonal variations in pCO2,  while the shelves in the southeastern Atlantic and in the southern Pacific reveal a much smaller seasonality. The calculation of temperature normalized pCO2 for several latitudes in different oceanic basins confirms that the seasonality in shelf pCO2 cannot solely be explained by

  16. Acclimation of bloom-forming and perennial seaweeds to elevated pCO2 conserved across levels of environmental complexity.

    Science.gov (United States)

    Xu, Dong; Schaum, Charlotte-Elisa; Lin, Fan; Sun, Ke; Munroe, James R; Zhang, Xiao W; Fan, Xiao; Teng, Lin H; Wang, Yi T; Zhuang, Zhi M; Ye, Naihao

    2017-11-01

    Macroalgae contribute approximately 15% of the primary productivity in coastal marine ecosystems, fix up to 27.4 Tg of carbon per year, and provide important structural components for life in coastal waters. Despite this ecological and commercial importance, direct measurements and comparisons of the short-term responses to elevated pCO 2 in seaweeds with different life-history strategies are scarce. Here, we cultured several seaweed species (bloom forming/nonbloom forming/perennial/annual) in the laboratory, in tanks in an indoor mesocosm facility, and in coastal mesocosms under pCO 2 levels ranging from 400 to 2,000 μatm. We find that, across all scales of the experimental setup, ephemeral species of the genus Ulva increase their photosynthesis and growth rates in response to elevated pCO 2 the most, whereas longer-lived perennial species show a smaller increase or a decrease. These differences in short-term growth and photosynthesis rates are likely to give bloom-forming green seaweeds a competitive advantage in mixed communities, and our results thus suggest that coastal seaweed assemblages in eutrophic waters may undergo an initial shift toward communities dominated by bloom-forming, short-lived seaweeds. © 2017 John Wiley & Sons Ltd.

  17. Fluctuating seawater pH/pCO2 regimes are more energetically expensive than static pH/pCO2 levels in the mussel Mytilus edulis.

    Science.gov (United States)

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

    2017-10-25

    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.

  18. High temperature reactor: Driving force to convert CO2 to fuel - HTR2008-58132

    International Nuclear Information System (INIS)

    McCormick, J. L.

    2008-01-01

    The rapidly increasing cost of petroleum products and uncertainty of long-term supply have prompted the U.S. military to aggressively pursue production of alternative fuels (synfuels) such as coal-to-liquids (CTL). U.S. Air Force is particularly active in this effort while the entire military is involved in simultaneously developing fuel specifications for alternative fuels that enable a single fuel for the entire battle space; all ground vehicles, aircraft and fuel cells. By limiting its focus on coal, tar sands and oil shale resources, the military risks violating federal law which requires the use of synfuels that have life cycle greenhouse gas emissions less than or equal to emissions from conventional petroleum fuels. A climate-friendly option would use a high temperature nuclear reactor to split water. The hydrogen (H 2 ) would be used in the reverse water gas shift (RWGS) to react with carbon dioxide (CO 2 ) to produce carbon monoxide (CO) and water. The oxygen (O 2 ) would be fed into a supercritical (SC) coal furnace. The flue gas CO 2 emissions would be stripped of impurities before reacting with H 2 in a RWGS process. Resultant carbon monoxide (CO) is fed, with additional H2, (extra H 2 needed to adjust the stoichiometry: 2 moles H 2 to one mole CO) into a conventional Fischer-Tropsch synthesis (FTS) to produce a heavy wax which is cracked and isomerized and refined to Jet Propulsion 8 (JP-8) and Jet Propulsion 5 (JP-5) fuels. The entire process offers valuable carbon-offsets and multiple products that contribute to lower syn-fuel costs and to comply with the federal limitation imposed on syn-fuel purchases. While the entire process is not commercially available, component parts are being researched; their physical and chemical properties understood and some are state-of-the-art technologies. An international consortium should complete physical, chemical and economic flow sheets to determine the feasibility of this concept that, if pursued, has broad

  19. Characterization of gypsum crystals exposed to a high CO2 concentration fog using x-ray

    International Nuclear Information System (INIS)

    Carreño-Márquez, I. J. A.; Castillo-Sandoval, I.; Esparza-Ponce, H. E.; Fuentes-Cobas, L.; Montero-Cabrera, M. E.

    2015-01-01

    In Chihuahua State, a little town called Naica has the largest gypsum single crystals in the world. The growth of these structures has been described as a long and stable process developed over thousands of years. Due to the change in the environmental conditions, these crystals could suffer alterations on their surface. In this project we study the cause of possible deterioration of the giant crystals and intend to suggest measures for their preservation. For this sake, our first experiment consists on several gypsum crystals that have been subjected in a climate chamber to a fog at high CO 2 concentration and 51 °C for a period of time of six months, extracting two crystals every 15 days. Then the crystals have been characterized through Grazing Incidence X-Ray Diffraction using a diffractometer PanAlytical X’PertPro with two different detectors; Xe-filled proportional detector and a Pixel 3D detector. The results were compared to determine which technique is the most suitable to study the degradation of gypsum single crystals. In the two cases, we have identified only the gypsum phase, but with different crystal plane orientations

  20. Cold cathode electron guns in the LASL high power short-pulse CO2 laser program

    International Nuclear Information System (INIS)

    Singer, S.; Ladish, J.S.; Nutter, M.J.

    1975-01-01

    The Electron Beam Controlled Discharge CO 2 Laser is now firmly established as the only high power short pulse laser amplifier that has been demonstrated to have scaling capabilities to large apertures and energies much greater than 100 J. These devices require a beam of energetic electrons to control the gas discharge that produces the required population inversion. Until recently, the electron source was usually a thermionic emitter, even for rather large lasers, whose heater requirements dwarfed the pulsed energies associated with the transient operation of the laser. With the advent of reliable cold-cathode electron guns, the operation of these lasers has been greatly simplified. At LASL, there are four electron beam controlled laser systems which are in operation, under construction, or in design: the 1 kJ system, now operational; the 2.5 kJ system; the 10 kJ system; and the 100 kJ system. Only the first uses thermionic-emitter electron guns; the remainder use or will use cold cathode sources. The operation of the 200 x 35 cm 2 two sided cold cathode electron gun used in the 2.5 kJ laser system and to be used in the 10 kJ laser is described

  1. A synthetic-dynamic method for water solubility measurements in high pressure CO_2 using ATR–FTIR spectroscopy

    International Nuclear Information System (INIS)

    Comak, Gurbuz; Foltran, Stéphanie; Ke, Jie; Pérez, Eduardo; Sánchez-Vicente, Yolanda; George, Michael W.; Poliakoff, Martyn

    2016-01-01

    Highlights: • A synthetic method using ATR–FTIR spectroscopy has been developed to measure the solubility of water in CO_2_. • New data have been obtained for the dew point of the water at 4.05 MPa, 5.05 MPa and 6.03 MPa. • These data fill a gap in the literature and could be of significance for CO_2 transport in pipelines for CCS technology. - Abstract: A new synthetic method for studying phase behaviour is described using Attenuated Total Reflection (ATR) spectroscopy. The method has been developed to provide relevant information on the solubility of water in CO_2. The dew point of water has been determined at three different pressures, viz. (4.05, 5.05 and 6.03) MPa with mole fractions of water between 0.01 and 0.04. The data obtained fill the gap in the literature in these regions of pressures and temperatures and could be of high importance in the context of Carbon Capture and Storage (CCS) technology. Indeed, the presence of water in the captured CO_2 could damage the pipeline used for CO_2 transport. Hence, it is very important to have a fully understanding of the behaviour of the (CO_2 + H_2O) mixtures in wide range of temperature relevant for CCS.

  2. Phase behavior for the poly(alkyl methacrylate)+supercritical CO2+DME mixture at high pressures

    International Nuclear Information System (INIS)

    Choi, Yong-Seok; Chio, Sang-Won; Byun, Hun-Soo

    2016-01-01

    The phase behavior curves of binary and ternary system were measured for poly(alkyl methacrylate) in supercritical CO 2 , as well as for the poly(alkyl methacrylate)+dimethyl ether (DME) (or 1-butene) in CO 2 . The solubility curves are reported for the poly(alkyl methacrylate)+DME in supercritical CO 2 at temperature from (300 to 465) K and a pressure from (3.66 to 248) MPa. Also, The high-pressure static-type apparatus of cloud-point curve was tested by comparing the measured phase behavior data of the poly(methyl methacrylate) [PMMA]+CO 2 +20.0 and 30.4 wt% methyl methacrylate (MMA) system with literature data of 10.4, 28.8 and 48.4 wt% MMA concentration. The phase behavior data for the poly(alkyl methacrylate)+CO 2 +DME mixture were measured in changes of the pressure-temperature (p, T) slope and with DME concentrations. Also, the cloud-point pressure for the poly(alkyl methacrylate)+1- butene solution containing supercritical CO 2 shows from upper critical solution temperature (UCST) region to lower critical solution temperature (LCST) region at concentration range from (0.0 to 95) wt% 1-butene at below 455 K and at below 245MPa.

  3. [Research on soil bacteria under the impact of sealed CO2 leakage by high-throughput sequencing technology].

    Science.gov (United States)

    Tian, Di; Ma, Xin; Li, Yu-E; Zha, Liang-Song; Wu, Yang; Zou, Xiao-Xia; Liu, Shuang

    2013-10-01

    Carbon dioxide Capture and Storage has provided a new option for mitigating global anthropogenic CO2 emission with its unique advantages. However, there is a risk of the sealed CO2 leakage, bringing a serious threat to the ecology system. It is widely known that soil microorganisms are closely related to soil health, while the study on the impact of sequestered CO2 leakage on soil microorganisms is quite deficient. In this study, the leakage scenarios of sealed CO2 were constructed and the 16S rRNA genes of soil bacteria were sequenced by Illumina high-throughput sequencing technology on Miseq platform, and related biological analysis was conducted to explore the changes of soil bacterial abundance, diversity and structure. There were 486,645 reads for 43,017 OTUs of 15 soil samples and the results of biological analysis showed that there were differences in the abundance, diversity and community structure of soil bacterial community under different CO, leakage scenarios while the abundance and diversity of the bacterial community declined with the amplification of CO2 leakage quantity and leakage time, and some bacteria species became the dominant bacteria species in the bacteria community, therefore the increase of Acidobacteria species would be a biological indicator for the impact of sealed CO2 leakage on soil ecology system.

  4. Highly CO2-supersaturated melts in the Pannonian lithospheric mantle - A transient carbon reservoir?

    Science.gov (United States)

    Créon, Laura; Rouchon, Virgile; Youssef, Souhail; Rosenberg, Elisabeth; Delpech, Guillaume; Szabó, Csaba; Remusat, Laurent; Mostefaoui, Smail; Asimow, Paul D.; Antoshechkina, Paula M.; Ghiorso, Mark S.; Boller, Elodie; Guyot, François

    2017-08-01

    Subduction of carbonated crust is widely believed to generate a flux of carbon into the base of the continental lithospheric mantle, which in turn is the likely source of widespread volcanic and non-volcanic CO2 degassing in active tectonic intracontinental settings such as rifts, continental margin arcs and back-arc domains. However, the magnitude of the carbon flux through the lithosphere and the budget of stored carbon held within the lithospheric reservoir are both poorly known. We provide new constraints on the CO2 budget of the lithospheric mantle below the Pannonian Basin (Central Europe) through the study of a suite of xenoliths from the Bakony-Balaton Highland Volcanic Field. Trails of secondary fluid inclusions, silicate melt inclusions, networks of melt veins, and melt pockets with large and abundant vesicles provide numerous lines of evidence that mantle metasomatism affected the lithosphere beneath this region. We obtain a quantitative estimate of the CO2 budget of the mantle below the Pannonian Basin using a combination of innovative analytical and modeling approaches: (1) synchrotron X-ray microtomography, (2) NanoSIMS, Raman spectroscopy and microthermometry, and (3) thermodynamic models (Rhyolite-MELTS). The three-dimensional volumes reconstructed from synchrotron X-ray microtomography allow us to quantify the proportions of all petrographic phases in the samples and to visualize their textural relationships. The concentration of CO2 in glass veins and pockets ranges from 0.27 to 0.96 wt.%, higher than in typical arc magmas (0-0.25 wt.% CO2), whereas the H2O concentration ranges from 0.54 to 4.25 wt.%, on the low end for estimated primitive arc magmas (1.9-6.3 wt.% H2O). Trapping pressures for vesicles were determined by comparing CO2 concentrations in glass to CO2 saturation as a function of pressure in silicate melts, suggesting pressures between 0.69 to 1.78 GPa. These values are generally higher than trapping pressures for fluid inclusions

  5. Full synergistic effect of hydrothermal NiCo2O4 nanosheets/CuCo2O4 nanocones supported on Ni foam for high-performance asymmetric supercapacitors

    Science.gov (United States)

    Wen, Shiyang; Liu, Yu; Bai, Hongye; Shao, Rong; Xu, Wei; Shi, Weidong

    2018-06-01

    In this work, a series of NiCo2O4/CuCo2O4 composites were prepared by a two-step hydrothermal method. The optimized NiCo2O4/CuCo2O4 electrode shows more than 5 times area capacitance (4.97 F cm-2) than pure NiCo2O4 at the current density of 1 mA cm-2. The best performance of sample assembled an asymmetric supercapacitor could reach up to 42 F g-1 at the current density of 1 A g-1. In addition, the maximum energy density of 15 W h kg-1 was achieved with the power density of 814 W kg-1. The as-prepared active electrode material also reveals excellent cycling stability with 90.6% capacitance retention after 5000 cycles. These results indicate potential application in developing energy storage devices with high energy density power density.

  6. Measurement and modeling of high-pressure (vapor + liquid) equilibria of (CO2 + alkanol) binary systems

    International Nuclear Information System (INIS)

    Bejarano, Arturo; Gutierrez, Jorge E.; Araus, Karina A.; Fuente, Juan C. de la

    2011-01-01

    Research highlights: → (Vapor + liquid) equilibria of three (CO 2 + C 5 alcohol) binary systems were measured. → Complementary data are reported at (313, 323 and 333) K and from (2 to 11) MPa. → No liquid immiscibility was observed at the temperatures and pressures studied. → Experimental data were correlated with the PR-EoS and the van de Waals mixing rules. → Correlation results showed relative deviations ≤8 % (liquid) and ≤2 % (vapor). - Abstract: Complementary isothermal (vapor + liquid) equilibria data are reported for the (CO 2 + 3-methyl-2-butanol), (CO 2 + 2-pentanol), and (CO 2 + 3-pentanol) binary systems at temperatures of (313, 323, and 333) K, and at pressure range of (2 to 11) MPa. For all (CO 2 + alcohol) systems, it was visually monitored that there was no liquid immiscibility at the temperatures and pressures studied. The experimental data were correlated with the Peng-Robinson equation of state using the quadratic mixing rules of van der Waals with two adjustable parameters. The calculated (vapor + liquid) equilibria compositions were found to be in good agreement with the experimental data with deviations for the mole fractions <8% and <2% for the liquid and vapor phase, respectively.

  7. Day and Night Variability of CO2 Fluxes and Priming Effects under zea Mays Measured in High Resolution

    Science.gov (United States)

    Splettstoesser, Thomas; Pausch, Johanna

    2017-04-01

    Plant induced increase of soil organic matter turnover rates contribute to carbon emissions in agricultural land use systems. In order to better understand these rhizosphere priming effects, we conducted an experiment which enabled us to monitor CO2 fluxes under Zea mays plants in high resolution. The experiment was conducted in a climate chamber where the plants were grown in tightly sealed boxes for 40 days and CO2 efflux from soil was measured twice a day. Continuous 13C-CO2 label was used to allow differentiation between plant- and soil-derived CO2.This enabled us to monitor root respiration and soil organic matter turnover in the early stages of plant growth and to highlight changes in soil CO2 emissions and priming effects between day and night. The measurements were conducted with a PICARRO G2131-I C high-precision isotopic CO2 Analyzer (PICARRO INC.) utilizing an automated valve system governed by a CR1000 data logger (Campbell Scientific). After harvest roots and shoots were analyzed for 13C content. Microbial biomass, root length density and enzymatic activities in soil were measured and linked to soil organic matter turnover rates. Results show an increased soil CO2 efflux at day time periods and an overall increase with increasing plant biomass. No difference in chloroform fumigation extractable microbial biomass has been found but a strong negative priming effect was measured in the short experimental period, suggesting that the microbes shifted to the utilization of plant exudates without actual microbial growth triggered by the new labile C input. This is coherent with the observed shift in enzyme kinetics. With this experimental setup we show that measurement of priming effects in high resolution can be achieved.

  8. Utilization of CO2 in High Performance Building and Infrastructure Products

    Energy Technology Data Exchange (ETDEWEB)

    DeCristofaro, Nicholas [Solidia Technologies Inc., Piscataway, NJ (United States)

    2015-11-01

    The overall objective of DE-FE0004222 was to demonstrate that calcium silicate phases, in the form of either naturally-occuring minerals or synthetic compounds, could replace Portland cement in concrete manufacturing. The calcium silicate phases would be reacted with gaseous CO2 to create a carbonated concrete end-product. If successful, the project would offer a pathway to a significant reduction in the carbon footprint associated with the manufacture of cement and its use in concrete (approximately 816 kg of CO2 is emitted in the production of one tonne of Portland cement). In the initial phases of the Technical Evaluation, Rutgers University teamed with Solidia Technologies to demonstrate that natural wollastonite (CaSiO3), milled to a particle size distribution consistent with that of Portland cement, could indeed fit this bill. The use of mineral wollastonite as a cementitious material would potentially eliminate the CO2 emitted during cement production altogether, and store an additional 250 kg of CO2 during concrete curing. However, it was recognized that mineral wollastonite was not available in volumes that could meaningfully impact the carbon footprint associated with the cement and concrete industries. At this crucial juncture, DE-FE0004222 was redirected to use a synthetic version of wollastonite, hereafter referred to as Solidia Cement™, which could be manufactured in conventional cement making facilities. This approach enables the new cementitious material to be made using existing cement industry raw material supply chains, capital equipment, and distribution channels. It would also offer faster and more complete access to the concrete marketplace. The latter phases of the Technical Evaluation, conducted with Solidia Cement made in research rotary kilns, would demonstrate that industrially viable CO2-curing practices were possible. Prototypes of full-scale precast concrete products such as pavers, concrete masonry units, railroad ties, hollow

  9. Activated carbons prepared from hazelnut shells, walnut shells and peanut shells for high CO2 adsorption

    Directory of Open Access Journals (Sweden)

    Lewicka Katarzyna

    2017-06-01

    Full Text Available Research treats about producing activated carbons for CO2 capture from hazelnut shells (HN, walnut shells (WN and peanut shells (PN. Saturated solution of KOH was used as an activating agent in ratio 1:1. Samples were carbonized in the furnace in the range of temperatures 600°C–900°C. Properties of carbons were tested by N2 adsorption method, using BET equation, DFT method and volumetric CO2 adsorption method. With the increase of carbonization temperature specific surface area of studied samples increased. The largest surface area was calculated for samples carbonized at 900°C and the highest values of CO2 adsorption had samples: PN900 at 0°C (5.5 mmol/g and WN900 at 25°C (4.34 mmol/g. All of the samples had a well-developed microporous structure.

  10. High-throughput synthesis of mixed-metal electrocatalysts for CO2 reduction

    International Nuclear Information System (INIS)

    He, Jingfu; Dettelbach, Kevan E.; Li, Tengfei; Salvatore, Danielle A.; Berlinguette, Curtis P.

    2017-01-01

    The utilization of CO 2 as a feedstock requires fundamental breakthroughs in catalyst design. The efficiencies and activities of pure metal electrodes towards the CO 2 reduction reaction are established, but the corresponding data on mixed-metal systems are not as well developed. In this study we show that the near-infrared driven decomposition (NIRDD) of solution-deposited films of metal salts and subsequent electrochemical reduction offers the unique opportunity to form an array of mixed-metal electrocatalyst coatings with excellent control of the metal stoichiometries. This synthetic method enabled us to develop an empirical structure-property correlation to help inform the development of optimized CO 2 catalyst compositions. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. BioCO2 - a multidisciplinary, biological approach using solar energy to capture CO2 while producing H2 and high value products.

    Science.gov (United States)

    Skjånes, Kari; Lindblad, Peter; Muller, Jiri

    2007-10-01

    Many areas of algae technology have developed over the last decades, and there is an established market for products derived from algae, dominated by health food and aquaculture. In addition, the interest for active biomolecules from algae is increasing rapidly. The need for CO(2) management, in particular capture and storage is currently an important technological, economical and global political issue and will continue to be so until alternative energy sources and energy carriers diminish the need for fossil fuels. This review summarizes in an integrated manner different technologies for use of algae, demonstrating the possibility of combining different areas of algae technology to capture CO(2) and using the obtained algal biomass for various industrial applications thus bringing added value to the capturing and storage processes. Furthermore, we emphasize the use of algae in a novel biological process which produces H(2) directly from solar energy in contrast to the conventional CO(2) neutral biological methods. This biological process is a part of the proposed integrated CO(2) management scheme.

  12. CO2-assisted high pressure homogenization: a solvent-free process for polymeric microspheres and drug-polymer composites.

    Science.gov (United States)

    Kluge, Johannes; Mazzotti, Marco

    2012-10-15

    The study explores the enabling role of near-critical CO(2) as a reversible plasticizer in the high pressure homogenization of polymer particles, aiming at their comminution as well as at the formation of drug-polymer composites. First, the effect of near-critical CO(2) on the homogenization of aqueous suspensions of poly lactic-co-glycolic acid (PLGA) was investigated. Applying a pressure drop of 900 bar and up to 150 passes across the homogenizer, it was found that particles processed in the presence of CO(2) were generally of microspherical morphology and at all times significantly smaller than those obtained in the absence of a plasticizer. The smallest particles, exhibiting a median x(50) of 1.3 μm, were obtained by adding a small quantity of ethyl acetate, which exerts on PLGA an additional plasticizing effect during the homogenization step. Further, the study concerns the possibility of forming drug-polymer composites through simultaneous high pressure homogenization of the two relevant solids, and particularly the effect of near-critical CO(2) on this process. Therefore, PLGA was homogenized together with crystalline S-ketoprofen (S-KET), a non-steroidal anti-inflammatory drug, at a drug to polymer ratio of 1:10, a pressure drop of 900 bar and up to 150 passes across the homogenizer. When the process was carried out in the presence of CO(2), an impregnation efficiency of 91% has been reached, corresponding to 8.3 wt.% of S-KET in PLGA; moreover, composite particles were of microspherical morphology and significantly smaller than those obtained in the absence of CO(2). The formation of drug-polymer composites through simultaneous homogenization of the two materials is thus greatly enhanced by the presence of CO(2), which increases the efficiency for both homogenization and impregnation. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. The carbon curse: Are fuel rich countries doomed to high CO2 intensities?

    International Nuclear Information System (INIS)

    Friedrichs, Jörg; Inderwildi, Oliver R.

    2013-01-01

    The carbon curse is a new theory, related to but distinct from the resource curse. It states that fossil-fuel rich countries tend to follow more carbon-intensive developmental pathways than [if they were] fossil-fuel poor countries, due to a hitherto unappreciated syndrome of causal mechanisms. First, fuel rich countries emit significant amounts of CO 2 in the extraction of fuel and through associated wasteful practices such as gas flaring. Second, easy access to domestic fuel in such countries leads to crowding-out effects for their energy mix and economic structure (for example, abundant oil may displace other fuels from the energy mix and lead to the “Dutch Disease”). Third, fuel abundance weakens the economic incentive to invest in energy efficiency. Fourth, governments in fuel rich countries are under considerable pressure to grant uneconomic fuel consumption subsidies, which further augments the carbon intensity of their economic output. Due to the combined effect of these causal mechanisms, it is genuinely difficult for fuel rich countries to evade carbon-intensive developmental pathways. And yet there are remarkable exceptions like Norway. Such positive outliers indicate that the carbon curse is not destiny when appropriate policies are adopted. - Highlights: • Fuel rich countries appear doomed to high carbon intensity, for four reasons. • First, extractive emissions; and, second, fuel-related crowding-out effects. • Third, weaker incentives to invest in improvements of energy efficiency. • Fourth, significant pressure to grant uneconomic fuel consumption subsidies. • But the carbon curse is not destiny, as indicated by positive outliers like Norway

  14. High power CO2 laser development with AOM integration for ultra high-speed pulses

    Science.gov (United States)

    Bohrer, Markus; Vaupel, Matthias; Nirnberger, Robert; Weinberger, Bernhard; Jamalieh, Murad

    2017-01-01

    There is a 500 billion USD world market for packaging expected to grow to a trillion in 2030. Austria plays an important role world wide for high speed laser engraving applications — especially when it comes to high end solutions. Such high end solutions are fundamental for the production of print forms for the packaging and decorating industry (e. g. cans). They are additionally used for security applications (e. g. for printing banknotes), for the textile printing industry and for creating embossing forms (e. g. for the production of dashboards in the automotive industry). High speed, high precision laser engraving needs laser resonators with very stable laser beams (400 - 800W) especially in combination with AOMs. Based upon a unique carbon fiber structure - stable within the sub-micrometer range - a new resonator has been developed, accompanied by most recent thermo-mechanical FEM calculations. The resulting beam is evaluated on an automated optical bench using hexapods, allowing to optimize the complete beam path with collimators and AOM. The major steps related to laser engraving of dry offset printing plates during the full workflow from the artists design to the printed result on an aluminum can is presented in this paper as well as laser characteristics, AOM integration and correlative CLSM and SEM investigation of the results.

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

    KAUST Repository

    Burdett, HL; Perna, Gabriela; McKay, L; Broomhead, G; Kamenos, NA

    2017-01-01

    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

  16. Translating crustacean biological responses from CO2 bubbling experiments into population-level predictions

    Science.gov (United States)

    Many studies of animal responses to ocean acidification focus on uniformly conditioned age cohorts that lack complexities typically found in wild populations. These studies have become the primary data source for predicting higher level ecological effects, but the roles of intras...

  17. Highly Stable Porous Covalent Triazine-Piperazine Linked Nanoflower as a Feasible Adsorbent for Flue Gas CO2 Capture

    KAUST Repository

    Das, Swapan Kumar; Wang, Xinbo; Ostwal, Mayur; Zhao, Yunfeng; Han, Yu; Lai, Zhiping

    2016-01-01

    robustness under acidic and basic medium and high thermal stability up to 773 K. The CTPP possess high surface area (779 m2/g) and single-component gas adsorption study exhibited enhanced CO2 and CH4 uptake of 3.48 mmol/g, 1.09 mmol/g, respectively at 273 K

  18. Influence of CO2 on ultrasound-induced polymerizations in high-pressure fluids

    NARCIS (Netherlands)

    Kuijpers, M.W.A.; Jacobs, L.J.M.; Kemmere, M.F.; Keurentjes, J.T.F.

    2005-01-01

    A strong viscosity increase upon polymerization hinders cavitation and subsequent radical formation during an ultrasound-induced bulk polymerization. Ultrasound-induced radical polymerizations of methyl methacrylate (MMA) have been performed in CO2-expanded MMA, as well as in bulk MMA. For this

  19. Highly efficient repetitively pulsed electric-discharge industrial CO2 laser

    International Nuclear Information System (INIS)

    Osipov, V V; Ivanov, M G; Lisenkov, V V; Platonov, V V

    2002-01-01

    The results of investigations aimed at the development of a repetitively pulsed CO 2 laser with an active medium volume of 1000 cm 3 pumped by a combined discharge are generalised. It is shown that, at pump pulse durations of 200-500 μs the optimal characteristics are achieved at active-medium pressures of 60-100 Torr. In this case, the laser efficiency at the initial stage of its operation can reach 22% and; if the energy dissipated in the region of the cathode potential drop is neglected, the efficiency is 28%. After emission of 3x10 5 pulses, the laser efficiency falls to 12%. It has been found that adding CO with a relative concentration [CO]/[CO 2 ] ∼0.75 increases the input and output power by almost 50%. The lasing efficiency is then 10%-12%, and the service life of the laser is by more than 10 6 pulses with a power decrease of no more than 10%. Adding hydrogen up to a concentration [H 2 ]/[CO 2 ] ∼10 leads to an increase in the energy supplied to the gas due to a decrease in the rate of ionisation processes. However, the optimal ratio is [H 2 ]/[CO 2 ] ∼ 1, at which the output power increases by 15%. In a long-term operating mode, the laser power is 1 kW at a peak power of 10 kW and an efficiency of 12%. (lasers)

  20. Phytoplankton Do Not Produce Carbon-Rich Organic Matter in High CO2 Oceans

    Science.gov (United States)

    Kim, Ja-Myung; Lee, Kitack; Suh, Young-Sang; Han, In-Seong

    2018-05-01

    The ocean is a substantial sink for atmospheric carbon dioxide (CO2) released as a result of human activities. Over the coming decades the dissolved inorganic C concentration in the surface ocean is predicted to increase, which is expected to have a direct influence on the efficiency of C utilization (consumption and production) by phytoplankton during photosynthesis. Here we evaluated the generality of C-rich organic matter production by examining the elemental C:N ratio of organic matter produced under conditions of varying pCO2. The data used in this analysis were obtained from a series of pelagic in situ pCO2 perturbation studies that were performed in the diverse ocean regions and involved natural phytoplankton assemblages. The C:N ratio of the resulting particulate and dissolved organic matter did not differ across the range of pCO2 conditions tested. In particular, the ratio for particulate organic C and N was found to be 6.58 ± 0.05, close to the theoretical value of 6.6.

  1. Highly sensitive miniature fluidic flowmeter based on an FBG heated by Co2+-doped fiber

    NARCIS (Netherlands)

    Liu, Z.; Htein, L.; Cheng, L.K.; Martina, Q.; Jansen, R.; Tam, H.Y.

    2017-01-01

    In this paper, we present a miniature fluidic flow sensor based on a short fiber Bragg grating inscribed in a single mode fiber and heated by Co2+-doped multimode fibers. The proposed flow sensor was employed to measure the flow rates of oil and water, showing good sensitivity of 0.339 nm/(m/s) and

  2. Viability of sublethally injured coliform bacteria on fresh-cut cabbage stored in high CO2 atmospheres following rinsing with electrolyzed water.

    Science.gov (United States)

    Izumi, Hidemi; Inoue, Ayano

    2018-02-02

    The extent of sublethally injured coliform bacteria on shredded cabbage, either rinsed or not rinsed with electrolyzed water, was evaluated during storage in air and high CO 2 controlled atmospheres (5%, 10%, and 15%) at 5°C and 10°C using the thin agar layer (TAL) method. Sublethally injured coliform bacteria on nonrinsed shredded cabbage were either absent or they were injured at a 64-65% level when present. Rinsing of shredded cabbage with electrolyzed water containing 25ppm available chlorine reduced the coliform counts by 0.4 to 1.1 log and caused sublethal injury ranging from 42 to 77%. Pantoea ananatis was one of the species injured by chlorine stress. When shredded cabbage, nonrinsed or rinsed with electrolyzed water, was stored in air and high CO 2 atmospheres at 5°C for 7days and 10°C for 5days, coliform counts on TAL plates increased from 3.3-4.5 to 6.5-9.0 log CFU/g during storage, with the increase being greater at 10°C than at 5°C. High CO 2 of 10% and 15% reduced the bacterial growth on shredded cabbage during storage at 5°C. Although injured coliform bacteria were not found on nonrinsed shredded cabbage on the initial day, injured coliforms at a range of 49-84% were detected on samples stored in air and high CO 2 atmospheres at 5°C and 10°C. Injured cells were detected more frequently during storage at both temperatures irrespective of the CO 2 atmosphere when shredded cabbage was rinsed with electrolyzed water. These results indicated that injured coliform bacteria on shredded cabbage, either rinsed or not rinsed with electrolyzed water, exhibited different degrees of injury during storage regardless of the CO 2 atmosphere and temperature tested. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Performance evaluation of high-sulphur coal-fired USC plant integrated with SNOX and CO2 capture sections

    International Nuclear Information System (INIS)

    Cau, Giorgio; Tola, Vittorio; Bassano, Claudia

    2015-01-01

    In recent years coal-fired power plants have increased their role in the global energy scenario thanks to reliability, security of fuel supply and lower cost of fuel and electricity. In this framework global warming issues require a sustainable use of coal and great efforts for greenhouse gases reduction, addressing research and development projects towards more efficient solutions in terms of efficiency and environmental impact. With this aim in this paper a performance assessment of an Ultra Super Critical (USC) steam plant integrated with a CO 2 removal section was carried out. The study is based on simulation models specifically developed through Aspen-Plus and Gate-Cycle software platforms. Performance was assessed referring to typical USC commercial size plants (400–600 MW), fuelled by a mix of a low-sulphur coal and a Sardinian (Sulcis) high-sulphur coal. The USC plant, based on a reheated and regenerative Rankine cycle, is integrated with an SNOX section, with integrated DeNO x and DeSO x processes, and a low temperature CO 2 capture section. The SNOX technology shows several advantages in comparison to conventional de-nitrification and de-sulphuration systems. In particular it is capable to remove both nitrogen and sulphur oxides, requiring less energy absorption compared to traditional FGD systems, allowing a further preheating of the combustion air and without producing process waste. Besides the SNOX releases a commercial product as the sulphuric acid (H 2 SO 4 ) and operational costs are reduced when sulphur content in the coal increases. The CO 2 capture system was based on a chemical absorption process. A conventional system based on an amine (monoethanolamine, MEA) aqueous solution was considered. In order to match high pressure and purity CO 2 transportation requirements, the CO 2 removal section is also integrated with a conditioning and compression section. A performance assessment of the USC plant was carried out varying the high-sulphur coal

  4. The effects of prolonged exposure to elevated temperatures and elevated CO2 levels on the growth, yield and dry matter partitioning of field-sown meadow fescue

    Directory of Open Access Journals (Sweden)

    Kaija Hakala

    1996-05-01

    Full Text Available Field-sown meadow fescue (Festuca pratensis, cv. Kalevi stands were exposed to elevated temperatures (+3°C and elevated CO2, (700 ppm levels in two experiments conducted in 1992-1993 (experiment 1 and in 1994-1995 (experiment 2. Total aboveground yield was, on average, 38% higher at elevated than at ambient temperatures. At ambient temperatures elevated CO2 increased the number of tillers by 63% in 1992, 24% in 1993, 90% in 1994 and 14% in 1995. At elevated temperatures, the increase in tiller number in elevated CO2 was seen only in the first growing seasons after sowing. The total yield in a growing season was about 10% higher in elevated CO2 in experiment 1. In experiment 2 the yield was more than 20% higher in elevated CO2 at elevated temperatures, whereas at ambient temperatures the rise in CO2 level had no effect on the yield; the root biomass, however, increased by more than 30%. In elevated CO2 at ambient temperatures the root biomass also increased in experiment I, but at elevated temperatures there was no consistent change. The soluble carbohydrate content of above-ground biomass was 5-48% higher in elevated CO2 at most of the measuring times during the growing season, but the nitrogen content did not show a clear decrease. The reasons for the lack of a marked increase in biomass in elevated CO2 despite a 40-60% increase in photosynthesis are discussed.

  5. High temperature oxidation behaviour of nanostructured cermet coatings in a mixed CO2 - O2 environment

    Science.gov (United States)

    Farrokhzad, M. A.; Khan, T. I.

    2014-06-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (α-Al2O3 and TiO2) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500°C, 600°C and 700°C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15% CO2, 10% O2 and 75% N2. This research investigates the effects of CO2 and O2 partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO2 at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO2 in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO2 acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO2 particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Ni-Ti compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings.

  6. Woody biomass production during the second rotation of a bio-energy Populus plantation increases in a future high CO2 world

    NARCIS (Netherlands)

    Liberloo, M.; Calfapietra, C.; Lukac, M.; Godbold, D.; Luos, Z.B.; Polles, A.; Hoosbeek, M.R.; Kull, O.; Marek, M.; Rianes, Chr.; Rubino, M.; Taylors, G.; Scarascia-Mugnozza, G.; Ceulemans, R.

    2006-01-01

    The quickly rising atmospheric carbon dioxide (CO2)-levels, justify the need to explore all carbon (C) sequestration possibilities that might mitigate the current CO2 increase. Here, we report the likely impact of future increases in atmospheric CO2 on woody biomass production of three poplar

  7. Experimental evidence of two mechanisms coupling leaf-level C assimilation to rhizosphere CO2 release

    Science.gov (United States)

    Zachary Kayler; Claudia Keitel; Kirstin Jansen; Arthur Gessler

    2017-01-01

    The time span needed for carbon fixed by plants to induce belowground responses of root and rhizosphere microbial metabolic processing is of high importance for quantifying the coupling between plant canopy physiology and soil biogeochemistry, but recent observations of a rapid link cannot be explained by new assimilate transport by phloem mass flow alone. We performed...

  8. Synthesis and Electrospraying of Nanoscale MOF (Metal Organic Framework) for High-Performance CO2 Adsorption Membrane

    Science.gov (United States)

    Wahiduzzaman; Allmond, Kelsey; Stone, John; Harp, Spencer; Mujibur, Khan

    2017-01-01

    We report the sonochemical synthesis of MOF (metal organic framework) nanoparticles of 30-200 nm in size and electrospraying of those particles on electrospun nanofibers to process a MOF-attached nanofibrous membrane. This membrane displayed significant selectivity towards CO2 and capacity of adsorbing with 4000-5000 ppm difference from a mixed gas flow of 1% CO2 and 99% N2. Applying ultrasonic waves during the MOF synthesis offered rapid dispersion and formation of crystalline MOF nanoparticles in room temperature. The MOF nanoparticles of 100-200 nm in size displayed higher surface area and adsorption capacity comparing to that of 30-60 nm in size. Nanofibrous membrane was produced by electrospinning of MOF blended PAN solution followed by electrospraying of additional MOF nanoparticles. This yielded uniform MOF deposition on nanofibers, occurred due to electrostatic attraction between highly charged nanoparticles and conductive nanofibers. A test bench for real-time CO2 adsorption at room temperature was built with non-dispersive Infrared (NDIR) CO2 sensors. Comparative tests were performed on the membrane to investigate its enhanced adsorption capacity. Three layers of the as-produced membranes displayed CO2 adsorption for approximately 2 h. Thermogravimetric analysis (TGA) of the membrane showed the thermal stability of the MOF and PAN up to 290 and 425 °C, respectively.

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

    Directory of Open Access Journals (Sweden)

    R. Thyrhaug

    2008-07-01

    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.

  10. A highly selective copper-indium bimetallic electrocatalyst for the electrochemical reduction of aqueous CO2to CO

    KAUST Repository

    Rasul, Shahid

    2014-12-23

    The challenge in the electrochemical reduction of aqueous carbon dioxide is in designing a highly selective, energy-efficient, and non-precious-metal electrocatalyst that minimizes the competitive reduction of proton to form hydrogen during aqueous CO2 conversion. A non-noble metal electrocatalyst based on a copper-indium (Cu-In) alloy that selectively converts CO2 to CO with a low overpotential is reported. The electrochemical deposition of In on rough Cu surfaces led to Cu-In alloy surfaces. DFT calculations showed that the In preferentially located on the edge sites rather than on the corner or flat sites and that the d-electron nature of Cu remained almost intact, but adsorption properties of neighboring Cu was perturbed by the presence of In. This preparation of non-noble metal alloy electrodes for the reduction of CO2 provides guidelines for further improving electrocatalysis.

  11. Low to High Spin-State Transition Induced by Charge Ordering in Antiferromagnetic YBaCo2O5

    International Nuclear Information System (INIS)

    Vogt, T.; Woodward, P. M.; Karen, P.; Hunter, B. A.; Henning, P.; Moodenbaugh, A. R.

    2000-01-01

    The oxygen-deficient double perovskite YBaCo 2 O 5 , containing corner-linked CoO 5 square pyramids as principal building units, undergoes a paramagnetic to antiferromagnetic spin ordering at 330 K. This is accompanied by a tetragonal to orthorhombic distortion. Below 220 K orbital ordering and long-range Co 2+ /Co 3+ charge ordering occur as well as a change in the Co 2+ spin state from low to high spin. This transition is shown to be very sensitive to the oxygen content of the sample. To our knowledge this is the first observation of a spin-state transition induced by long-range orbital and charge ordering. (c) 2000 The American Physical Society

  12. Hierarchically porous Ni monolith@branch-structured NiCo2O4 for high energy density supercapacitors

    Directory of Open Access Journals (Sweden)

    Mengjie Xu

    2016-06-01

    Full Text Available A variety of NiCo2O4 nanostrucutures ranging from nanowire to nanoplate and branched structures were successfully prepared via a simple hydrothermal process. The experimental results show that NiCo2O4 with branched structures possesses the best overall electrochemical performance. The improvement of energy density was explored in terms of hierarchically three-dimensional (3D metal substrates and a high specific area capacitance, and area energy density is obtained with hierarchically porous Ni monolith synthesized through a controlled combustion procedure.

  13. Explaining CO2 fluctuations observed in snowpacks

    Science.gov (United States)

    Graham, Laura; Risk, David

    2018-02-01

    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.

  14. Reducing cement's CO2 footprint

    Science.gov (United States)

    van Oss, Hendrik G.

    2011-01-01

    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.

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

    International Nuclear Information System (INIS)

    Yang, Wei

    2014-01-01

    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

  16. High net CO2 and CH4 release at a eutrophic shallow lake on a formerly drained fen

    Science.gov (United States)

    Franz, Daniela; Koebsch, Franziska; Larmanou, Eric; Augustin, Jürgen; Sachs, Torsten

    2016-05-01

    Drained peatlands often act as carbon dioxide (CO2) hotspots. Raising the groundwater table is expected to reduce their CO2 contribution to the atmosphere and revitalise their function as carbon (C) sink in the long term. Without strict water management rewetting often results in partial flooding and the formation of spatially heterogeneous, nutrient-rich shallow lakes. Uncertainties remain as to when the intended effect of rewetting is achieved, as this specific ecosystem type has hardly been investigated in terms of greenhouse gas (GHG) exchange. In most cases of rewetting, methane (CH4) emissions increase under anoxic conditions due to a higher water table and in terms of global warming potential (GWP) outperform the shift towards CO2 uptake, at least in the short term.Based on eddy covariance measurements we studied the ecosystem-atmosphere exchange of CH4 and CO2 at a shallow lake situated on a former fen grassland in northeastern Germany. The lake evolved shortly after flooding, 9 years previous to our investigation period. The ecosystem consists of two main surface types: open water (inhabited by submerged and floating vegetation) and emergent vegetation (particularly including the eulittoral zone of the lake, dominated by Typha latifolia). To determine the individual contribution of the two main surface types to the net CO2 and CH4 exchange of the whole lake ecosystem, we combined footprint analysis with CH4 modelling and net ecosystem exchange partitioning.The CH4 and CO2 dynamics were strikingly different between open water and emergent vegetation. Net CH4 emissions from the open water area were around 4-fold higher than from emergent vegetation stands, accounting for 53 and 13 g CH4 m-2 a-1 respectively. In addition, both surface types were net CO2 sources with 158 and 750 g CO2 m-2 a-1 respectively. Unusual meteorological conditions in terms of a warm and dry summer and a mild winter might have facilitated high respiration rates. In sum, even after 9

  17. High-Calorific Biogas Production by Selective CO2 Retention at Autogenerated Biogas Pressures up to 20 Bar

    NARCIS (Netherlands)

    Lindeboom, R.E.F.; Weijma, J.; Lier, van J.B.

    2012-01-01

    Autogenerative high pressure digestion (AHED) is a novel configuration of anaerobic digestion, in which micro-organisms produce autogenerated biogas pressures up to 90 bar with >90% CH4-content in a single step reactor. The less than 10% CO2-content was postulated to be resulting from

  18. A high resolution interferometric method to measure local swelling due to CO2 exposure in coal and shale

    NARCIS (Netherlands)

    Pluymakers, A.; Liu, J.; Kohler, F.; Renard, F.; Dysthe, D.

    2018-01-01

    We present an experimental method to study time-dependent, CO2-induced, local topography changes in mm-sized composite samples, plus results showing heterogeneous swelling of coal and shale on the nano- to micrometer scale. These results were obtained using high resolution interferometry

  19. 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

    2002-09-01

    -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

  20. One-pot synthetic method to prepare highly N-doped nanoporous carbons for CO2 adsorption

    International Nuclear Information System (INIS)

    Meng, Long-Yue; Park, Soo-Jin

    2014-01-01

    A one-pot synthetic method was used for the preparation of nanoporous carbon containing nitrogen from polypyrrole (PPY) using NaOH as the activated agent. The activation process was carried out under set conditions (NaOH/PPY = 2 and NaOH/PPY = 4) at different temperatures in 600–900 °C for 2 h. The effect of the activation conditions on the pore structure, surface functional groups and CO 2 adsorption capacities of the prepared N-doped activated carbons was examined. The carbon was analyzed by X-ray photoelectron spectroscopy (XPS), N2/77 K full isotherms, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The CO 2 adsorption capacity of the N-doped activated carbon was measured at 298 K and 1 bar. By dissolving the activation agents, the N-doped activated carbon exhibited high specific surface areas (755–2169 m 2 g −1 ) and high pore volumes (0.394–1.591 cm 3 g −1 ). In addition, the N-doped activated carbons contained a high N content at lower activation temperatures (7.05 wt.%). The N-doped activated carbons showed a very high CO 2 adsorption capacity of 177 mg g −1 at 298 K and 1 bar. The CO 2 adsorption capacity was found to be dependent on the microporosity and N contents. - Highlights: • A one-pot synthetic method was used for the preparation of N-doped nanoporous carbons. • Polypyrrole (PPY) were activated with NaOH under set conditions (NaOH/PPY = 2 and 4). • N-doped activated carbon exhibited high specific surface areas (2169 m 2 g −1 ). • The carbons showed a very high CO 2 adsorption capacity of 177 mg g −1 at 298 K

  1. Concentration of phenolic compounds is increased in lettuce grown under high light intensity and elevated CO2.

    Science.gov (United States)

    Pérez-López, Usue; Sgherri, Cristina; Miranda-Apodaca, Jon; Micaelli, Francesco; Lacuesta, Maite; Mena-Petite, Amaia; Quartacci, Mike Frank; Muñoz-Rueda, Alberto

    2018-02-01

    The present study was focused on lettuce, a widely consumed leafy vegetable for the large number of healthy phenolic compounds. Two differently-pigmented lettuce cultivars, i.e. an acyanic-green leaf cv. and an anthocyanic-red one, were grown under high light intensity or elevated CO 2 or both in order to evaluate how environmental conditions may affect the production of secondary phenolic metabolites and, thus, lettuce quality. Mild light stress imposed for a short time under ambient or elevated CO 2 concentration increased phenolics compounds as well as antioxidant capacity in both lettuce cvs, indicating how the cultivation practice could enhance the health-promoting benefits of lettuce. The phenolic profile depended on pigmentation and the anthocyanic-red cv. always maintained a higher phenolic amount as well as antioxidant capacity than the acyanic-green one. In particular, quercetin, quercetin-3-O-glucuronide, kaempferol, quercitrin and rutin accumulated under high light or high CO 2 in the anthocyanic-red cv., whereas cyanidin derivatives were responsive to mild light stress, both at ambient and elevated CO 2 . In both cvs total free and conjugated phenolic acids maintained higher values under all altered environmental conditions, whereas luteolin reached significant amounts when both stresses were administered together, indicating, in this last case, that the enzymatic regulation of the flavonoid synthesis could be differently affected, the synthesis of flavones being favored. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Study on excitation of vibrational levels of osmium tetroxide molecule by the continuous CO2 laser radiation

    International Nuclear Information System (INIS)

    Kompanets, O.N.; Letokhov, V.S.; Minogin, V.G.

    1975-01-01

    The mechanism of nonlinear infrared absorption in OsO 4 has been studied using a single-frequence continuous-wave CO 2 laser (10.6 μ). Measured are relationships between the OsO 4 absorption coefficient and the laser radiation intensity, the week beam transmission through a cell filled with OsO 4 and the frequency of the intensity modulation of the strong beam which saturates the absorption. It is indicated that the thermal mechanism prevails in OsO 4 bleaching under pressure (>=) 1mm Hg. A strong infrared fluorescence observed and studied at 5.3 and 10.6 μ in the molecular OsO 4 in the field of the high-power CO 2 laser has supplied another proof of the conclusion. The thermal diffusion rate and the coefficient of thermal conductivity for OsO 4 vapours have been determined. It has been revealed that the hot bands represent a significant part in thermal mechanism of the laser radiation absorption by the molecule

  3. Development of experimental structure and influence of high CO2 concentration in maize cro Desenvolvimento de estrutura experimentale influências da alta concentração de CO2 na cultura do milho

    Directory of Open Access Journals (Sweden)

    João B. Lopes da Silva

    2012-04-01

    Full Text Available Maize is a C4 plant that shows few or no response to high [CO2]. Thus, this study aimed to analyze the photosynthetic rate and yield of maize under high [CO2] and develop open-top chambers (OTC to create an atmosphere enriched with CO2. The experiment was conducted between October 2008 and March 2009. The OTCs were developed in modular scheme. Measurement of photosynthetic rates, transpiration, stomata conductance, grain yield and dry matter were performed. The experimental design was randomized blocks with four replications and three treatments: P1 - plants grown in OTC with 700 ppm [CO2], P2 - plants grown in OTC with environmental [CO2], and P3 - control, cultivated in open field. The results were analyzed by ANOVA and Tukey's test (PrO milho é uma planta C4 que apresenta pouca, ou nenhuma, resposta às elevadas [CO2]; assim, neste trabalho, objetivou-se analisar respostas fisiológicas e produtivas da cultura do milho sob alta [CO2], e desenvolver câmaras de topo aberto (CTA para criar uma atmosfera enriquecida com CO2. O experimento foi conduzido entre outubro de 2008 e março de 2009. As CTAs foram desenvolvidas em esquema modular. Foram realizadas medições da taxa fotossintética, transpiração, condutância estomática, produção de grãos e matéria seca. O delineamento experimental foi em blocos casualizados, com quatro repetições e três tratamentos: P1 - plantas cultivadas em CTA a [CO2] de 700ppm; P2 - plantas cultivadas em CTAcom [CO2] ambiente; e P3 -plantas cultivadas em campo aberto, testemunhas. Os resultados obtidos foram submetidos à análise de variância e teste de Tukey (Pr<0,05. As câmaras reduzem em 25% a Radiação Fotossinteticamente Ativa e aumentam a temperatura do ar e das folhas, em relação ao ambiente externo. As plantas sob alta [CO2] (P1 apresentaram as maiores taxas fotossintéticas e as menores condutâncias estomáticas e transpiração. O peso total dos grãos (g e a matéria seca da parte a

  4. High resolution numerical investigation on the effect of convective instability on long term CO2 storage in saline aquifers

    International Nuclear Information System (INIS)

    Lu, C; Lichtner, P C

    2007-01-01

    CO 2 sequestration (capture, separation, and long term storage) in various geologic media including depleted oil reservoirs, saline aquifers, and oceanic sediments is being considered as a possible solution to reduce green house gas emissions. Dissolution of supercritical CO 2 in formation brines is considered an important storage mechanism to prevent possible leakage. Accurate prediction of the plume dissolution rate and migration is essential. Analytical analysis and numerical experiments have demonstrated that convective instability (Rayleigh instability) has a crucial effect on the dissolution behavior and subsequent mineralization reactions. Global stability analysis indicates that a certain grid resolution is needed to capture the features of density-driven fingering phenomena. For 3-D field scale simulations, high resolution leads to large numbers of grid nodes, unfeasible for a single workstation. In this study, we investigate the effects of convective instability on geologic sequestration of CO 2 by taking advantage of parallel computing using the code PFLOTRAN, a massively parallel 3-D reservoir simulator for modeling subsurface multiphase, multicomponent reactive flow and transport based on continuum scale mass and energy conservation equations. The onset, development and long-term fate of a supercritical CO 2 plume will be resolved with high resolution numerical simulations to investigate the rate of plume dissolution caused by fingering phenomena

  5. CO2 laser development

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    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

  6. High Fidelity Computational Analysis of CO2 Trapping at Pore Scales

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vinod

    2013-07-13

    With an alarming rise in carbon dioxide (CO2) emission from anthropogenic sources, CO2 sequestration has become an attractive choice to mitigate the emission. Some popular storage media for CO{sub 2} are oil reservoirs, deep coal-bed, and deep oceanic-beds. These have been used for the long term CO{sub 2} storage. Due to special lowering viscosity and surface tension property of CO{sub 2}, it has been widely used for enhanced oil recovery. The sites for CO{sub 2} sequestration or enhanced oil recovery mostly consist of porous rocks. Lack of knowledge of molecular mobility under confinement and molecule-surface interactions between CO2 and natural porous media results in generally governed by unpredictable absorption kinetics and total absorption capacity for injected fluids, and therefore, constitutes barriers to the deployment of this technology. Therefore, it is important to understand the flow dynamics of CO{sub 2} through the porous microstructures at the finest scale (pore-scale) to accurately predict the storage potential and long-term dynamics of the sequestered CO{sub 2}. This report discusses about pore-network flow modeling approach using variational method and analyzes simulated results this method simulations at pore-scales for idealized network and using Berea Sandstone CT scanned images. Variational method provides a promising way to study the kinetic behavior and storage potential at the pore scale in the presence of other phases. The current study validates variational solutions for single and two-phase Newtonian and single phase non-Newtonian flow through angular pores for special geometries whose analytical and/or empirical solutions are known. The hydraulic conductance for single phase flow through a triangular duct was also validated against empirical results derived from lubricant theory.

  7. The rise of the photosynthetic rate when light intensity increases is delayed in ndh gene-defective tobacco at high but not at low CO2 concentrations

    Directory of Open Access Journals (Sweden)

    Mercedes eMartin

    2015-02-01

    Full Text Available The 11 plastid ndh genes have hovered frequently on the edge of dispensability, being absent in the plastid DNA of many algae and certain higher plants. We have compared the photosynthetic activity of tobacco (Nicotiana tabacum, cv. Petit Havana with five transgenic lines (ndhF, pr-ndhF, T181D, T181A and ndhF FC and found that photosynthetic performance is impaired in transgenic ndhF-defective tobacco plants at rapidly fluctuating light intensities and higher than ambient CO2 concentrations. In contrast to wild type and ndhF FC, which reach the maximum photosynthetic rate in less than one min when light intensity suddenly increases, ndh defective plants (ndhF and T181A show up to a 5 min delay in reaching the maximum photosynthetic rate at CO2 concentrations higher than the ambient 360 ppm. Net photosynthesis was determined at different CO2 concentrations when sequences of 130, 870, 61, 870 and 130 μmol m−2 s−1 PAR sudden light changes were applied to leaves and photosynthetic efficiency and entropy production were determined as indicators of photosynthesis performance. The two ndh-defective plants, ndhF and T181A, had lower photosynthetic efficiency and higher entropy production than wt, ndhF FC and T181D tobacco plants, containing full functional ndh genes, at CO2 concentrations above 400 ppm. We propose that the Ndh complex improves cyclic electron transport by adjusting the redox level of transporters during the low light intensity stage. In ndhF-defective strains, the supply of electrons through the Ndh complex fails, transporters remain over-oxidized (specially at high CO2 concentrations and the rate of cyclic electron transport is low, impairing the ATP level required to rapidly reach high CO2 fixation rates in the following high light phase. Hence, ndh genes could be dispensable at low but not at high atmospheric concentrations of CO2.

  8. High-performance modeling of CO2 sequestration by coupling reservoir simulation and molecular dynamics

    KAUST Repository

    Bao, Kai

    2013-01-01

    The present work describes a parallel computational framework for CO2 sequestration simulation by coupling reservoir simulation and molecular dynamics (MD) on massively parallel HPC systems. In this framework, a parallel reservoir simulator, Reservoir Simulation Toolbox (RST), solves the flow and transport equations that describe the subsurface flow behavior, while the molecular dynamics simulations are performed to provide the required physical parameters. Numerous technologies from different fields are employed to make this novel coupled system work efficiently. One of the major applications of the framework is the modeling of large scale CO2 sequestration for long-term storage in the subsurface geological formations, such as depleted reservoirs and deep saline aquifers, which has been proposed as one of the most attractive and practical solutions to reduce the CO2 emission problem to address the global-warming threat. To effectively solve such problems, fine grids and accurate prediction of the properties of fluid mixtures are essential for accuracy. In this work, the CO2 sequestration is presented as our first example to couple the reservoir simulation and molecular dynamics, while the framework can be extended naturally to the full multiphase multicomponent compositional flow simulation to handle more complicated physical process in the future. Accuracy and scalability analysis are performed on an IBM BlueGene/P and on an IBM BlueGene/Q, the latest IBM supercomputer. Results show good accuracy of our MD simulations compared with published data, and good scalability are observed with the massively parallel HPC systems. The performance and capacity of the proposed framework are well demonstrated with several experiments with hundreds of millions to a billion cells. To our best knowledge, the work represents the first attempt to couple the reservoir simulation and molecular simulation for large scale modeling. Due to the complexity of the subsurface systems

  9. CO2 laser-fabricated cladding light strippers for high-power fiber lasers and amplifiers.

    Science.gov (United States)

    Boyd, Keiron; Simakov, Nikita; Hemming, Alexander; Daniel, Jae; Swain, Robert; Mies, Eric; Rees, Simon; Andrew Clarkson, W; Haub, John

    2016-04-10

    We present and characterize a simple CO2 laser processing technique for the fabrication of compact all-glass optical fiber cladding light strippers. We investigate the cladding light loss as a function of radiation angle of incidence and demonstrate devices in a 400 μm diameter fiber with cladding losses of greater than 20 dB for a 7 cm device length. The core losses are also measured giving a loss of cladding light stripping of a 300 W laser diode with minimal heating of the fiber coating and packaging adhesives.

  10. Alignment system for large high-power CO2 laser fusion systems

    International Nuclear Information System (INIS)

    Bausman, M.D.; Liberman, I.; Manning, J.P.; Singer, S.

    1977-01-01

    Aligning a pulsed CO 2 laser fusion system involves control systems which insure that the centers of beams follow a prescribed path to within 1 mm, that the pointing of the beams is correct to approximately 20 microradians, and that focal spot at the location of the experimental fusion target be placed to accuracies of 10 to 20 micrometers laterally and approximately 50 micrometers axially. These alignments are accomplished by a variety of sensing techniques which include thermal pinholes and quadrant detectors, Seebeck effect silicon detectors, and imaging autocollimating Hartmann test procedures employing ir vidicon systems

  11. High efficiency metal marking with CO2 laser and glass marking with excimer laser

    DEFF Research Database (Denmark)

    Bastue, Jens; Olsen, Flemmming Ove

    1997-01-01

    with a thoroughly tested ray-tracing model is presented and compared with experimental results. Special emphasis is put on two different applications namely marking in metal with TEA-CO2 laser and marking in glass with excimer laser. The results are evaluated on the basis of the achievable energy enhancement......Today, mask based laser materials processing and especially marking is widely used. However, the energy efficiency in such processes is very low [1].This paper gives a review of the results, that may be obtained using the energy enhancing technique [1]. Results of simulations performed...

  12. Elevated CO2 levels affects the concentrations of copper and cadmium in crops grown in soil contaminated with heavy metals under fully open-air field conditions.

    Science.gov (United States)

    Guo, Hongyan; Zhu, Jianguo; Zhou, Hui; Sun, Yuanyuan; Yin, Ying; Pei, Daping; Ji, Rong; Wu, Jichun; Wang, Xiaorong

    2011-08-15

    Elevated CO(2) levels and the increase in heavy metals in soils through pollution are serious problems worldwide. Whether elevated CO(2) levels will affect plants grown in heavy-metal-polluted soil and thereby influence food quality and safety is not clear. Using a free-air CO(2) enrichment (FACE) system, we investigated the impacts of elevated atmospheric CO(2) on the concentrations of copper (Cu) or cadmium (Cd) in rice and wheat grown in soil with different concentrations of the metals in the soil. In the two-year study, elevated CO(2) levels led to lower Cu concentrations and higher Cd concentrations in shoots and grain of both rice and wheat grown in the respective contaminated soil. Elevated CO(2) levels slightly but significantly lowered the pH of the soil and led to changes in Cu and Cd fractionation in the soil. Our study indicates that elevated CO(2) alters the distribution of contaminant elements in soil and plants, thereby probably affecting food quality and safety.

  13. Growth, reproductive phenology and yield responses of a potential biofuel plant, Jatropha curcas grown under projected 2050 levels of elevated CO2.

    Science.gov (United States)

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

    2014-11-01

    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.

  14. Elevated CO_2 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

    2017-01-01

    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.

  15. Simulation and initial experiments of a high power pulsed TEA CO2 laser

    Science.gov (United States)

    Torabi, R.; Saghafifar, H.; Koushki, A. M.; Ganjovi, A. A.

    2016-01-01

    In this paper, the output characteristics of a UV pin array pre-ionized TEA CO2 laser have been simulated and compared with the associated experimental data. In our simulation, a new theoretical model has been improved for transient behavior analysis of the discharge current pulse. The laser discharge tube was modeled by a nonlinear RLC electric circuit as a real model for electron density calculation. This model was coupled with a six-temperature model (6TM) in order to simulation dynamic emission processes of the TEA CO2 laser. The equations were solved numerically by the fourth order Runge-Kutta numerical method and some important variables such as current and voltage of the main discharge, resistance of the plasma column and electron density in the main discharge region, were calculated as functions of time. The effects of non-dissociation factor, rotational quantum number and output coupler reflectivity were also studied theoretically. The experimental and simulation results are in good agreement.

  16. Fabrication and Characterization of Polyimide-CNTs hybrid membrane to enhance high performance CO2 separation

    Directory of Open Access Journals (Sweden)

    Tutuk Djoko Kusworo

    2015-03-01

    Full Text Available This study investigates the CO2 separation performance of a hybrid membranes flat sheet based on polyimide incorporated with carbon nanotubes (CNTs particles. CNTs was selected and its loading were a 1 wt% in total solid. The hybrid composite membranes were fabricated in order to increase their separation performance for the gaseous mixture of CO2 and CH4. Hybrid Composite  membrane incorporated carbon nanotubes were mannufactured  by the dry-wet phase inversion technique using flat sheet membrane casting machine system,  in which the CNTs were embedded into the polyimide membrane and the resulting membranes were characterized. The results from the FESEM, DSC and FTIR analysis confirmed that chemical modification on carbon nanotubes surface had taken place. Sieve-in-a-cage’ morphology observed shows the poor adhesion between polymer and unmodified CNT. The results revealed that the good multi-wall carbon nanotubes dispersion leads to enhanced gas permeation properties. It is also concluded that addition of carbon nanotubes particles into the matrix of Polyimide polymer has significant effect on the membrane structure and properties.

  17. Heterogeneous NiCo2O4@polypyrrole core/sheath nanowire arrays on Ni foam for high performance supercapacitors

    Science.gov (United States)

    Hu, Jing; Li, Minchan; Lv, Fucong; Yang, Mingyang; Tao, Pengpeng; Tang, Yougen; Liu, Hongtao; Lu, Zhouguang

    2015-10-01

    A novel heterogeneous NiCo2O4@PPy core/sheath nanowire arrays are directly grown on Ni foam involving three facile steps, hydrothermal synthesis and calcination of NiCo2O4 nanowire arrays and subsequent in-situ oxidative polymerization of polypyrrole (PPy). When investigated as binder- and conductive additive-free electrodes for supercapacitors (SCs) in 6 M KOH, the NiCo2O4@PPy core/sheath nanowire arrays exhibit high areal capacitance of 3.49 F cm-2 at a discharge current density of 5 mA cm-2, which is almost 1.5 times as much as the pristine NiCo2O4 (2.30 F cm-2). More importantly, it can remain 3.31 F cm-2 (94.8% retention) after 5000 cycles. The as-obtained electrode also displays excellent rate capability, whose areal capacitance can still remain 2.79 F cm-2 while the discharge current density is increased to 50 mA cm-2. The remarkable electrochemical performance is mainly attributed to the unique heterogeneous core/sheath nanowire-array architectures.

  18. Amine-tethered solid adsorbents coupling high adsorption capacity and regenerability for CO2 capture from ambient air.

    Science.gov (United States)

    Choi, Sunho; Gray, McMahan L; Jones, Christopher W

    2011-05-23

    Silica supported poly(ethyleneimine) (PEI) materials are prepared via impregnation and demonstrated to be promising adsorbents for CO(2) capture from ultra-dilute gas streams such as ambient air. A prototypical class 1 adsorbent, containing 45 wt% PEI (PEI/silica), and two new modified PEI-based aminosilica adsorbents, derived from PEI modified with 3-aminopropyltrimethoxysilane (A-PEI/silica) or tetraethyl orthotitanate (T-PEI/silica), are prepared and characterized by using thermogravimetric analysis and FTIR spectroscopy. The modifiers are shown to enhance the thermal stability of the polymer-oxide composites, leading to higher PEI decomposition temperatures. The modified adsorbents present extremely high CO(2) adsorption capacities under conditions simulating ambient air (400 ppm CO(2) in inert gas), exceeding 2 mol(CO (2)) kg(sorbent)(-1), as well as enhanced adsorption kinetics compared to conventional class 1 sorbents. The new adsorbents show excellent stability in cyclic adsorption-desorption operations, even under dry conditions in which aminosilica adsorbents are known to lose capacity due to urea formation. Thus, the adsorbents of this type can be considered promising materials for the direct capture of CO(2) from ultra-dilute gas streams such as ambient air. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. High Resolution Measurement of Rhizosphere Priming Effects and Temporal Variability of CO2 Fluxes under Zea Mays

    Science.gov (United States)

    Splettstößer, T.; Pausch, J.

    2016-12-01

    Plant induced increase of soil organic matter turnover rates contribute to carbon emissions in agricultural land use systems. In order to better understand these rhizosphere priming effects, we conducted an experiment, which enabled us to monitor CO2 fluxes under zea mays plants with high resolution. The experiment was conducted in a climate chamber where the plants were grown in thin, tightly sealed boxes for 40 days and CO2 efflux from soil was measured twice a day. 13C-CO2 was introduced to allow differentiation between plant and soil derived CO2.This enabled us to monitor root respiration and soil organic matter turnover in the early stages of plant growth and to highlight changes in soil CO2 emissions and priming effects between day and night. The measurements were conducted with a PICARRO G2131-I δ13C high-precision isotopic CO2 Analyzer (PICARRO INC.) utilizing an automated valve system governed by a CR1000 data logger (Campbell Scientific). After harvest roots and shoots were analyzed for 13C content. Microbial biomass, root length density and enzymatic activities in soil were measured and linked to soil organic matter turnover rates. In order to visualize the spatial distribution of carbon allocation to the root system a few plants were additionally labeled with 14C and 14C distribution was monitored by 14C imaging of the root systems over 4 days. Based on the 14C distribution a grid was chosen and the soil was sampled from each square of the grid to investigate the impact of carbon allocation hotspots on enzymatic activities and microbial biomass. First initial results show an increase of soil CO2 efflux in the night periods, whereby the contribution of priming is not fully analyzed yet. Additionally, root tips were identified as hotspots of short term carbon allocation via 14C imaging and an in increase in microbial biomass could be measured in this regions. The full results will be shown at AGU 2016.

  20. Impacts of elevated CO2 on exogenous Bacillus thuringiensis toxins and transgene expression in transgenic rice under different levels of nitrogen

    OpenAIRE

    Jiang, Shoulin; Lu, Yongqing; Dai, Yang; Qian, Lei; Muhammad, Adnan Bodlah; Li, Teng; Wan, Guijun; Parajulee, Megha N.; Chen, Fajun

    2017-01-01

    Recent studies have highlighted great challenges of transgene silencing for transgenic plants facing climate change. In order to understand the impacts of elevated CO2 on exogenous Bacillus thuringiensis (Bt) toxins and transgene expression in transgenic rice under different levels of N-fertilizer supply, we investigated the biomass, exogenous Bt toxins, Bt-transgene expression and methylation status in Bt rice exposed to two levels of CO2 concentrations and nitrogen (N) supply (1/8, 1/4, 1/2...

  1. High temporal resolution ecosystem CH4, CO2 and H2O flux data measured with a novel chamber technique

    Science.gov (United States)

    Steenberg Larsen, Klaus; Riis Christiansen, Jesper

    2016-04-01

    switching automatically between transparent and darkened mode enabling for separation of light-sensitive and light-indifferent processes in chambers. In a pilot study we measured hourly fluxes of CO2, H2O and CH4 continuously for two weeks in Danish Calluna vulgaris (common heather) heathland (Larsen et al. 2011). We will present an analysis of the novel, high-frequency data of CH4 fluxes under light and dark conditions, assess the advantages and limitations of the experimental setup and recommend future improvements of the technology involved. References: Carter, M.S., Larsen, K.S., et al. 2012. Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands: responses to climatic and environmental changes. Biogeosciences 3739-3755. Christiansen, J.R., Korhonen, J.F.J., et al. 2011. Assessing the effects of chamber placement, manual sampling and headspace mixing on CH4 fluxes in a laboratory experiment. Plant and Soil 343, 171-185. Christiansen, J.R., Outhwaite, J., et al. 2015. Comparison of CO2, CH4 and N2O soil-atmosphere exchange measured in static chambers with cavity ring-down spectroscopy and gas chromatography. Agricultural and Forest Meteorology 211-212, 48-57. Creelman, C., Nickerson, N., Risk, D., 2013. Quantifying Lateral Diffusion Error in Soil Carbon Dioxide Respiration Estimates using Numerical Modeling. Soil Science Society of America Journal 77, 699-708. Larsen, K.S., Andresen, L.C., et al. 2011. Reduced N cycling in response to elevated CO2, warming, and drought in a Danish heathland: Synthesizing results of the CLIMAITE project after two years of treatments. Global Change Biology 17, 1884-1899. Pihlatie, M.K., Christiansen, J.R., et al. 2013. Comparison of static chambers to measure CH4 emissions from soils. Agricultural and Forest Meteorology 171-172, 124-136.

  2. Assessing methane oxidation under landfill covers and its contribution to the above atmospheric CO2 levels: The added value of the isotope (δ13C and δ18O CO2; δ13C and δD CH4) approach

    International Nuclear Information System (INIS)

    Widory, D.; Proust, E.; Bellenfant, G.; Bour, O.

    2012-01-01

    Highlights: ► Comparison of the isotope and mass balance approaches to evaluate the level of methane oxidation within a landfill. ► The level of methane oxidation is not homogenous under the landfill cover and is strongly correlated to the methane flux. ► Isotope tracking of the contribution of the methane oxidation to the CO 2 concentrations in the ambient air. - Abstract: We are presenting here a multi-isotope approach (δ 13 C and δ 18 O of CO 2 ; δ 13 C and δD of CH 4 ) to assess (i) the level(s) of methane oxidation during waste biodegradation and its migration through a landfill cover in Sonzay (France), and (ii) its contribution to the atmospheric CO 2 levels above the surface. The isotope approach is compared to the more conventional mass balance approach. Results from the two techniques are comparable and show that the CH 4 oxidation under the landfill cover is heterogenous, with low oxidation percentages in samples showing high biogas fluxes, which was expected in clay covers presenting fissures, through which CH 4 is rapidly transported. At shallow depth, more immobile biogas pockets show a higher level of CH 4 oxidation by the methanotrophic bacteria. δ 13 C of CO 2 samples taken at different heights (from below the cover up to 8 m above the ground level) were also used to identify and assess the relative contributions of its main sources both under the landfill cover and in the surrounding atmosphere.

  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

    2015-01-01

    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......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...

  4. The penalty of a long, hot summer. Photosynthetic acclimation to high CO2 and continuous light in "living fossil" conifers.

    Science.gov (United States)

    Osborne, Colin P; Beerling, David J

    2003-10-01

    Deciduous forests covered the ice-free polar regions 280 to 40 million years ago under warm "greenhouse" climates and high atmospheric pCO2. Their deciduous habit is frequently interpreted as an adaptation for minimizing carbon losses during winter, but experiments with "living fossils" in a simulated warm polar environment refute this explanation. Measured carbon losses through leaf abscission of deciduous trees are significantly greater than losses through winter respiration in evergreens, yet annual rates of primary productivity are similar in all species. Here, we investigate mechanisms underlying this apparent paradox by measuring the seasonal patterns of leaf photosynthesis (A) under pCO2 enrichment in the same trees. During spring, A increased significantly in coastal redwood (Sequoia sempervirens), dawn redwood (Metasequoia glyptostroboides), and swamp cypress (Taxodium distichum) at an elevated pCO2 of 80 Pa compared with controls at 40 Pa. However, strong acclimation in Rubisco carboxylation capacity (Vc,max) completely offset the CO2 response of A in all species by the end of 6 weeks of continuous illumination in the simulated polar summer. Further measurements demonstrated the temporary nature of acclimation, with increases in Vc,max during autumn restoring the CO2 sensitivity of A. Contrary to expectations, the acclimation of Vc,max was not always accompanied by accumulation of leaf carbohydrates, but was associated with a decline in leaf nitrogen in summer, suggesting an alteration of the balance in plant sources and sinks for carbon and nitrogen. Preliminary calculations using A indicated that winter carbon losses through deciduous leaf abscission and respiration were recovered by 10 to 25 d of canopy carbon fixation during summer, thereby explaining the productivity paradox.

  5. Multi-Year Leaf-Level Response to Sub-Ambient and Elevated Experimental CO2 in Betula nana.

    Directory of Open Access Journals (Sweden)

    Alexandra J C Hincke

    Full Text Available 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.

  6. Thermal damage produced by high-irradiance continuous wave CO2 laser cutting of tissue.

    Science.gov (United States)

    Schomacker, K T; Walsh, J T; Flotte, T J; Deutsch, T F

    1990-01-01

    Thermal damage produced by continuous wave (cw) CO2 laser ablation of tissue in vitro was measured for irradiances ranging from 360 W/cm2 to 740 kW/cm2 in order to investigate the extent to which ablative cooling can limit tissue damage. Damage zones thinner than 100 microns were readily produced using single pulses to cut guinea pig skin as well as bovine cornea, aorta, and myocardium. Multiple pulses can lead to increased damage. However, a systematic decrease in damage with irradiance, predicted theoretically by an evaporation model of ablation, was not observed. The damage-zone thickness was approximately constant around the periphery of the cut, consistent with the existence of a liquid layer which stores heat and leads to tissue damage, and with a model of damage and ablation recently proposed by Zweig et al.

  7. NEOTEC: Negative-CO2-Emissions Marine Energy With Direct Mitigation of Global Warming, Sea-Level Rise and Ocean Acidification

    Science.gov (United States)

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

    2016-12-01

    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

  8. Electrospun N-Doped Porous Carbon Nanofibers Incorporated with NiO Nanoparticles as Free-Standing Film Electrodes for High-Performance Supercapacitors and CO2 Capture.

    Science.gov (United States)

    Li, Qi; Guo, Jiangna; Xu, Dan; Guo, Jianqiang; Ou, Xu; Hu, Yin; Qi, Haojun; Yan, Feng

    2018-04-01

    Carbon nanofibers (CNF) with a 1D porous structure offer promising support to encapsulate transition-metal oxides in energy storage/conversion relying on their high specific surface area and pore volume. Here, the preparation of NiO nanoparticle-dispersed electrospun N-doped porous CNF (NiO/PCNF) and as free-standing film electrode for high-performance electrochemical supercapacitors is reported. Polyacrylonitrile and nickel acetylacetone are selected as precursors of CNF and Ni sources, respectively. Dicyandiamide not only improves the specific surface area and pore volume, but also increases the N-doping level of PCNF. Benefiting from the synergistic effect between NiO nanoparticles (NPs) and PCNF, the prepared free-standing NiO/PCNF electrodes show a high specific capacitance of 850 F g -1 at a current density of 1 A g -1 in 6 m KOH aqueous solution, good rate capability, as well as excellent long-term cycling stability. Moreover, NiO NPs dispersed in PCNF and large specific surface area provide many electroactive sites, leading to high CO 2 uptake, and high-efficiency CO 2 electroreduction. The synthesis strategy in this study provides a new insight into the design and fabrication of promising multifunctional materials for high-performance supercapacitors and CO 2 electroreduction. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Measurements and trend analysis of O2, CO2 and δ13C of CO2 from the high altitude research station Junfgraujoch, Switzerland - A comparison with the observations from the remote site Puy de Dome, France

    International Nuclear Information System (INIS)

    Valentino, Francesco L.; Leuenberger, Markus; Uglietti, Chiara; Sturm, Patrick

    2008-01-01

    Atmospheric O 2 and CO 2 flask measurements from the high altitude research station Jungfraujoch, Switzerland, and from the observatory at Puy de Dome, France, are presented. Additionally, the Jungfraujoch δ 13 C record of CO 2 is discussed. The observations on flask samples collected at the Jungfraujoch station show, since 2003, an enhancement of the oxygen trend which amounts to about 45 per meg/year with a corresponding CO 2 increase of around 2.4 ppm/year. This enhancement is comparable with that observed at the Puy de Dome station where oxygen, since mid 2002, has decreased with a rate of about 50 per meg/year whilst the CO 2 increase was of around 1.7 ppm/year but exhibiting a higher variability. Several processes influence δO 2 /N 2 . However, these processes are marked with different oxidation ratios (O 2 :CO 2 ) that can be used to distinguish them. The apparent slopes calculated from correlation plots between de-trended CO 2 and δO 2 /N 2 records as well as between corresponding trends are significantly larger than the observed terrestrial exchange and fossil fuel emission slopes indicating a strong oceanic influence. Since ocean-atmosphere exchange can have very variable O 2 :CO 2 ratios depending on processes within the ocean, it is to our understanding the only possibility to explain our observations. The stability of the δO 2 /N 2 scale is critical in this regard, therefore, it is addressed here and we found no significant scale drift which would influence our trend calculations. In our view more important are criterions on the data selection before trend analysis

  10. The new Nissan high efficient 1.2L 3cyl GDI supercharged engine enables 95g/km CO2 emissions and high driving performance

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, Kazuaki; Satou, Takeshi [Nissan Motor Co., Ltd., Kanagawa (Japan)

    2012-11-01

    This paper describes a new 1.2-liter three cylinder gasoline engine named HR12DDR, with the target to achieve the lowest level CO2 in the European B-segment market and also, to satisfy the customer's driving pleasure through high output performance. This engine is developed with the consideration of meeting further strict regulations in the years ahead and of the possibility of being an alternative powertrain of diesel in the future as well. As a first step this engine was applied on the European Nissan Micra in 2011; achieving 95g/km CO2 emissions(NEDC mode). This low fuel consumption was realized mainly through technologies which scope to maximize thermal efficiency with high compression ratio, and to minimize the mechanical friction loss. The combustion was optimized by Direct Injection (DI) system. To obtain a better fuel economy performance without sacrificing high output, we chose the supercharger system with bypass valve and magnetic clutch. Details of the HR12DDR are presented here along with highlights of the applied technologies. (orig.)

  11. Comparison of atmospheric CO2 columns at high latitudes from ground-based and satellite-based methods

    Science.gov (United States)

    Jacobs, N.; Simpson, W. R.; Parker, H. A.; Tu, Q.; Blumenstock, T.; Dubey, M. K.; Hase, F.; Osterman, G. B.

    2017-12-01

    Total column measurements of carbon-dioxide (CO2) from the Orbiting Carbon Observatory-2 (OCO-2) satellite have been validated at mid-latitudes by comparison to the Total Carbon Column Observing Network (TCCON), but there are still a limited number of sites providing high-latitude validation data for satellite observations of CO2, and no TCCON sites in Alaska. To understand the global distribution of CO2 sources and sinks, it is essential that we increase the abundance of validation sites, particularly in the climate-sensitive high-latitude Boreal forest. Therefore, we began the Arctic Mobile Infrared Greenhouse Gas Observations (AMIGGO) campaign in the Boreal Forest region around Fairbanks, Alaska with the goal of satellite validation and measurement of natural ecosystem fluxes. In this campaign, we used the EM27/SUN mobile solar-viewing Fourier-transform infrared spectrometer (EM27/SUN FTS) to retrieve the total CO2 column and column-averaged dry-air mole fraction of CO2 (XCO2) with the GGG2014 algorithm. The EM27/SUN FTS was developed by the Karlsruhe Institute of Technology (KIT) in collaboration with Bruker optics (Gisi et al., 2012, doi:10.5194/amt-5-2969-2012) and has been deployed in urban areas to measure anthropogenic fluxes of CO2 and CH4. To evaluate the EM27/SUN performance, co-located observations were made with two EM27/SUN spectrometers, and we found that XCO2 differences between spectrometers were small (0.24ppm on average) and very stable over time. In this presentation, we report on 14 OCO-2 targeted overpasses that occurred from August 2016 through July 2017, along with additional targets obtained during ongoing observations in 2017. We investigate underlying reasons for observed differences between OCO-2 and ground-based XCO2 using methods developed by Wunch et al. (2017, doi:10.5194/amt-10-2209-2017). As an additional point of comparison, coincident aircraft observations by NOAA Earth System Research Laboratory (ESRL) Global Monitoring

  12. Thermophysical and radiation properties of high-temperature C4F8-CO2 mixtures to replace SF6 in high-voltage circuit breakers

    Science.gov (United States)

    Zhong, Linlin; Cressault, Yann; Teulet, Philippe

    2018-03-01

    C4F8-CO2 mixtures are one of the potential substitutes to SF6 in high-voltage circuit breakers. However, the arc quenching ability of C4F8-CO2 mixtures is still unknown. In order to provide the necessary basic data for the further investigation of arc quenching performance, the compositions, thermodynamic properties, transport coefficients, and net emission coefficients (NEC) of various C4F8-CO2 mixtures are calculated at temperatures of 300-30 000 K in this work. The thermodynamic properties are presented as the product of mass density and specific heat, i.e., ρCp. The transport coefficients include electrical conductivity, viscosity, and thermal conductivity. The atomic and molecular radiation are both taken into account in the calculation of NEC. The comparison of the properties between SF6 and C4F8-CO2 mixtures is also discussed to find their differences. The results of compositions show that C4F8-CO2 mixtures have a distinctive advantage over other alternative gases e.g., CF3I and C3F8, because the dissociative product (i.e., C4F6) of C4F8 at low temperatures has a very high dielectric strength. This is good for an arc quenching medium to endure the arc recovery phase. Compared with SF6, C4F8-CO2 mixtures present lower ρCp at temperatures below 2800 K and larger thermal conductivity above 2800 K. Based on the position of peaks in thermal conductivity, we predict that the cooling of C4F8-CO2 arc will be slowed down at higher temperatures than that of SF6 arc. It is also found that the mixing of CO2 shows slight effects on the electrical conductivity and NEC of C4F8-CO2 mixtures.

  13. Growth of highly mesoporous CuCo2O4@C core-shell arrays as advanced electrodes for high-performance supercapacitors

    Science.gov (United States)

    Yan, Hailong; Lu, Yang; Zhu, Kejia; Peng, Tao; Liu, Xianming; Liu, Yunxin; Luo, Yongsong

    2018-05-01

    A series of CuCo2O4 nanostructures with different morphologies were prepared by a hydrothermal method in combination with thermal treatment. The morphology, structure and composition were investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. As the electrode materials for supercapacitors, CuCo2O4 nanoneedles delivered the highest specific capacitance compared with other CuCo2O4 nanostructures. Electrochemical performance measurements demonstrate that the carbon layer can improve the electrochemical stability of CuCo2O4 nanoneedles. The CuCo2O4@C electrode exhibits a high specific capacitance of 1432.4 F g-1 at a current density of 1 A g-1, with capacitance retention of 98.2% after 3000 circles. These characteristics of CuCo2O4@C composite are mainly due to the unique one dimensional needle-liked architecture and the conducting carbon, which provide a faster ion/electron transfer rate. These excellent performances of the CuCo2O4@C electrode confirmed the material as a positive electrode for hybrid supercapacitor application.

  14. SC-CO2-assisted process for a high energy density aerogel supercapacitor: the effect of GO loading

    Science.gov (United States)

    Sarno, Maria; Baldino, Lucia; Scudieri, Carmela; Cardea, Stefano; Ciambelli, Paolo; Reverchon, Ernesto

    2017-05-01

    Energy density, safety, and simple and environmentally friendly preparation methods are very significant aspects in the realization of a compact supercapacitor. Herein we report the use of a supercritical CO2-assisted gel drying process (SC-CO2) for the preparation of porous electrodes containing dispersed graphene in a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) binder membrane to sandwich in a new portable supercapacitor based on graphene oxide (GO). A GO loading of 60 wt.% was found to give the best combination of factors (porosity, wettability, mechanical and electrochemical properties). Cycling voltammetry and charge/discharge studies showed an excellent capacitance behaviour and stability in an ionic liquid electrolyte, suggesting SC-CO2 processing as a promising platform to produce highly bulky and porous films for supercapacitors. The supercapacitor device delivers a very high energy density of 79.2 Wh kg-1 at a power density of 0.23 KW kg-1 (current density 0.5 A g-1, specific capacitance 36.2 F g-1) while that of steel remains at 50.3 Wh kg-1 at a power density of 2.8 KW kg-1 (current density 6 A g-1, specific capacitance 23.5 F g-1).

  15. Double-Layer Structured CO2 Adsorbent Functionalized with Modified Polyethyleneimine for High Physical and Chemical Stability.

    Science.gov (United States)

    Jeon, Sunbin; Jung, Hyunchul; Kim, Sung Hyun; Lee, Ki Bong

    2018-06-18

    CO 2 capture using polyethyleneimine (PEI)-impregnated silica adsorbents has been receiving a lot of attention. However, the absence of physical stability (evaporation and leaching of amine) and chemical stability (urea formation) of the PEI-impregnated silica adsorbent has been generally established. Therefore, in this study, a double-layer impregnated structure, developed using modified PEI, is newly proposed to enhance the physical and chemical stabilities of the adsorbent. Epoxy-modified PEI and diepoxide-cross-linked PEI were impregnated via a dry impregnation method in the first and second layers, respectively. The physical stability of the double-layer structured adsorbent was noticeably enhanced when compared to the conventional adsorbents with a single layer. In addition to the enhanced physical stability, the result of simulated temperature swing adsorption cycles revealed that the double-layer structured adsorbent presented a high potential working capacity (3.5 mmol/g) and less urea formation under CO 2 -rich regeneration conditions. The enhanced physical and chemical stabilities as well as the high CO 2 working capacity of the double-layer structured adsorbent were mainly attributed to the second layer consisting of diepoxide-cross-linked PEI.

  16. The future of the northeast Atlantic benthic flora in a high CO2 world.

    Science.gov (United States)

    Brodie, Juliet; Williamson, Christopher J; Smale, Dan A; Kamenos, Nicholas A; Mieszkowska, Nova; Santos, Rui; Cunliffe, Michael; Steinke, Michael; Yesson, Christopher; Anderson, Kathryn M; Asnaghi, Valentina; Brownlee, Colin; Burdett, Heidi L; Burrows, Michael T; Collins, Sinead; Donohue, Penelope J C; Harvey, Ben; Foggo, Andrew; Noisette, Fanny; Nunes, Joana; Ragazzola, Federica; Raven, John A; Schmidt, Daniela N; Suggett, David; Teichberg, Mirta; Hall-Spencer, Jason M

    2014-07-01

    Seaweed and seagrass communities in the northeast Atlantic have been profoundly impacted by humans, and the rate of change is accelerating rapidly due to runaway CO2 emissions and mounting pressures on coastlines associated with human population growth and increased consumption of finite resources. Here, we predict how rapid warming and acidification are likely to affect benthic flora and coastal ecosystems of the northeast Atlantic in this century, based on global evidence from the literature as interpreted by the collective knowledge of the authorship. We predict that warming will kill off kelp forests in the south and that ocean acidification will remove maerl habitat in the north. Seagrasses will proliferate, and associated epiphytes switch from calcified algae to diatoms and filamentous species. Invasive species will thrive in niches liberated by loss of native species and spread via exponential development of artificial marine structures. Combined impacts of seawater warming, ocean acidification, and increased storminess may replace structurally diverse seaweed canopies, with associated calcified and noncalcified flora, with simple habitats dominated by noncalcified, turf-forming seaweeds.

  17. Tropical coral reef habitat in a geoengineered, high-CO2 world

    Science.gov (United States)

    Couce, E.; Irvine, P. J.; Gregorie, L. J.; Ridgwell, A.; Hendy, E. J.

    2013-05-01

    Continued anthropogenic CO2 emissions are expected to impact tropical coral reefs by further raising sea surface temperatures (SST) and intensifying ocean acidification (OA). Although geoengineering by means of solar radiation management (SRM) may mitigate temperature increases, OA will persist, raising important questions regarding the impact of different stressor combinations. We apply statistical Bioclimatic Envelope Models to project changes in shallow water tropical coral reef habitat as a single niche (without resolving biodiversity or community composition) under various representative concentration pathway and SRM scenarios, until 2070. We predict substantial reductions in habitat suitability centered on the Indo-Pacific Warm Pool under net anthropogenic radiative forcing of ≥3.0 W/m2. The near-term dominant risk to coral reefs is increasing SSTs; below 3 W/m2 reasonably favorable conditions are maintained, even when achieved by SRM with persisting OA. "Optimal" mitigation occurs at 1.5 W/m2 because tropical SSTs overcool in a fully geoengineered (i.e., preindustrial global mean temperature) world.

  18. New highly fluorescent pH indicator for ratiometric RGB imaging of pCO2

    International Nuclear Information System (INIS)

    Schutting, Susanne; Klimant, Ingo; Borisov, Sergey M; De Beer, Dirk

    2014-01-01

    A new diketo-pyrrolo-pyrrole (DPP) indicator dye for optical sensing of carbon dioxide is prepared via a simple one step synthesis from commercially available low cost ‘Pigment Orange 73’. The pigment is modified via alkylation of one of the lactam nitrogens with a tert-butylbenzyl group. The indicator dye is highly soluble in organic solvents and in polymers and shows pH-dependent absorption (λ max 501 and 572 nm for the protonated and deprotonated forms, respectively) and emission spectra (λ max 524 and 605 nm for the protonated and deprotonated forms, respectively). Both the protonated and the deprotonated forms show high fluorescence quantum yields (Φ prot 0.86; Φ deprot 0.66). Hence, colorimetric read-out and ratiometric fluorescence intensity measurements are possible. The emission of the two forms of the indicator excellently matches the response of the green and the red channels of an RGB camera. This enables imaging of carbon dioxide distribution with a simple and low cost optical set-up. The sensor based on the new DPP dye shows very high sensitivity and is particularly promising for monitoring atmospheric levels of carbon dioxide. (paper)

  19. 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.

    2003-01-01

    . myrsinifolia, B. pendula and B. pubescens and the biomass accumulation of S. myrsinifolia. In the leaves, the content of individual phenolic compounds and the total phenolic allocation of the plants were affected by the treatments. Elevated CO 2 reduced the levels of some phenolic compounds and the level of nitrogen, while temperature elevation reduced the levels of many of the measured compounds in the leaves of all the plant species studied. Increased nitrogen supply reduced the levels of some of the individual compounds in birches. Performance of P. vitellinae fed with willow leaves grown under elevated CO 2 was reduced, while elevated temperature treatment compensated for this effect. Feeding of A. alni on birches was not affected by the treatments. These results show that the predicted atmospheric change will have various differential effects on boreal deciduous woody plants and on their herbivores both directly and indirectly via other trophic levels. These effects seem to be highly dependent on the particular species and even on the genotype within the species as well as on the type of chemical compound or plant growth parameter. Therefore, none of the existing hypotheses for predicting plant growth and chemical responses to environmental changes can satisfactorily explain the observed patterns of plant quality and herbivore performance. (orig.)

  20. Measurement of OCS, CO2, CO and H2O aboard NASA's WB-57 High Altitude Platform Using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS)

    Science.gov (United States)

    Leen, J. B.; Owano, T. G.; Du, X.; Gardner, A.; Gupta, M.

    2014-12-01

    Carbonyl sulfide (OCS) is the most abundant sulfur gas in the atmosphere and has been implicated in controlling the sulfur budget and aerosol loading of the stratosphere. In the troposphere, OCS is irreversibly consumed during photosynthesis and may serve as a tracer for gross primary production (GPP). Its primary sources are ocean outgassing, industrial processes, and biomass burning. Its primary sinks are vegetation and soils. Despite the importance of OCS in atmospheric processes, the OCS atmospheric budget is poorly determined and has high uncertainty. OCS is typically monitored using either canisters analyzed by gas chromatography or integrated atmospheric column measurements. Improved in-situ terrestrial flux and airborne measurements are required to constrain the OCS budget and further elucidate its role in stratospheric aerosol formation and as a tracer for biogenic volatile organics and photosynthesis. Los Gatos Research has developed a flight capable mid-infrared Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) analyzer to simultaneously quantify OCS, CO2, CO, and H2O in ambient air at up to 2 Hz. The prototype was tested on diluted, certified samples and found to be precise (OCS, CO2, CO, and H2O to better than ±4 ppt, ±0.2 ppm, ±0.31 ppb, and ±3.7 ppm respectively, 1s in 1 sec) and linear (R2 > 0.9997 for all gases) over a wide dynamic range (OCS, CO2, CO, and H2O ranging from 0.2 - 70 ppb, 500 - 3000 ppm, 150 - 480 ppb, and 7000 - 21000 ppm respectively). Cross-interference measurements showed no appreciable change in measured OCS concentration with variations in CO2 (500 - 3500 ppm) or CO. We report on high altitude measurements made aboard NASA's WB-57 research aircraft. Two research flights were conducted from Houston, TX. The concentration of OCS, CO2, CO, and H2O were continuously recorded from sea level to approximately 60,000 feet. The concentration of OCS was observed to increase with altitude through the troposphere due to the

  1. High-permeance crosslinked PTMSP thin-film composite membranes as supports for CO2 selective layer formation

    Directory of Open Access Journals (Sweden)

    Stepan D. Bazhenov

    2016-10-01

    Full Text Available In the development of the composite gas separation membranes for post-combustion CO2 capture, little attention is focused on the optimization of the membrane supports, which satisfy the conditions of this technology. The primary requirements to the membrane supports are concerned with their high CO2 permeance. In this work, the membrane supports with desired characteristics were developed as high-permeance gas separation thin film composite (TFC membranes with the thin defect-free layer from the crosslinked highly permeable polymer, poly[1-(trimethylsilyl-1-propyne] (PTMSP. This layer is insoluble in chloroform and can be used as a gutter layer for the further deposition of the СО2-selective materials from the organic solvents. Crosslinking of PTMSP was performed using polyethyleneimine (PEI and poly (ethyleneglycol diglycidyl ether (PEGDGE as crosslinking agents. Optimal concentrations of PEI in PTMSP and PEGDGE in methanol were selected in order to diminish the undesirable effect on the final membrane gas transport characteristics. The conditions of the kiss-coating technique for the deposition of the thin defect-free PTMSP-based layer, namely, composition of the casting solution and the speed of movement of the porous commercial microfiltration-grade support, were optimized. The procedure of post-treatment with alcohols and alcohol solutions was shown to be crucial for the improvement of gas permeance of the membranes with the crosslinked PTMSP layer having thickness ranging within 1–2.5 μm. The claimed membranes showed the following characteristics: CO2 permeance is equal to 50–54 m3(STP/(m2 h bar (18,500–20,000 GPU, ideal CO2/N2 selectivity is 3.6–3.7, and their selective layers are insoluble in chloroform. Thus, the developed high-permeance TFC membranes are considered as a promising supports for further modification by enhanced CO2 selective layer formation. Keywords: Thin-film composite membrane

  2. In-operando elucidation of bimetallic CoNi nanoparticles during high-temperature CH 4 /CO 2 reaction

    KAUST Repository

    Al-Sabban, Bedour

    2017-05-02

    Dry reforming of methane (DRM) proceeds via CH4 decomposition to leave surface carbon species, followed by their removal with CO2-derived species. Reactivity tuning for stoichiometric CH4/CO2 reactants was attempted by alloying the non-noble metals Co and Ni, which have high affinity with CO2 and high activity for CH4 decomposition, respectively. This study was focused on providing evidence of the capturing surface coverage of the reactive intermediates and the associated structural changes of the metals during DRM at high temperature using in-operando X-ray absorption spectroscopy (XAS). On the Co catalysts, the first-order effects with respect to CH4 pressure and negative-order effects with respect to CO2 pressure on the DRM rate are consistent with the competitive adsorption of the surface oxygen species on the same sites as the CH4 decomposition reaction. The Ni surface provides comparatively higher rates of CH4 decomposition and the resultant DRM than the Co catalyst but leaves some deposited carbon on the catalyst surface. In contrast, the bimetallic CoNi catalyst exhibits reactivity towards the DRM but with kinetic orders resembling Co catalyst, producing negligible carbon deposition by balancing CH4 and CO2 activation. The in-operando X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) measurements confirmed that the Co catalyst was progressively oxidized from the surface to the bulk with reaction time, whereas CoNi and Ni remained relatively reduced during DRM. Density functional theory (DFT) calculation considering the high reaction temperature for DRM confirmed the unselective site arrangement between Co and Ni atoms in both the surface and bulk of the alloy nanoparticle (NP). The calculated heat of oxygen chemisorption became more exothermic in the order of Ni, CoNi, Co, consistent with the catalytic behavior. The comprehensive experimental and theoretical evidence provided herein clearly suggests

  3. The CO_2 absorption spectrum in the 2.3 µm transparency window by high sensitivity CRDS: (I) Rovibrational lines

    International Nuclear Information System (INIS)

    Vasilchenko, S.; Konefal, M.; Mondelain, D.; Kassi, S.; Čermák, P.; Tashkun, S.A.; Perevalov, V.I.; Campargue, A.

    2016-01-01

    The absorption of carbon dioxide is very weak near 2.3 µm which makes this transparency window of particular interest for the study of Venus’ lower atmosphere. As a consequence of the weakness of the transitions located in this region, previous experimental data are very scarce and spectroscopic databases provide calculated line lists which should be tested and validated by experiment. In this work, we use the Cavity Ring Down Spectroscopy (CRDS) technique for a high sensitivity characterization of the CO_2 absorption spectrum in two spectral intervals of the 2.3 µm window: 4248–4257 and 4295–4380 cm"−"1 which were accessed using a Distributed Feed Back (DFB) diode laser and a Vertical External Cavity Surface Emitting Laser (VECSEL) as light sources, respectively. The achieved sensitivity (noise equivalent absorption, α_m_i_n, on the order of 5×10"−"1"0 cm"−"1) allowed detecting numerous new transitions with intensity values down to 5×10"−"3"0 cm/molecule. The rovibrational assignments were performed by comparison with available theoretical line lists in particular those obtained at IAO Tomsk using the global effective operator approach. Hot bands of the main isotopologue and "1"6O"1"2C"1"8O bands were found to be missing in the HITRAN database while they contribute importantly to the absorption in the region. Additional CRDS spectra of a CO_2 sample highly enriched in "1"8O were recorded in order to improve the spectroscopy of this isotopologue. As a result about 700 lines of "1"6O"1"2C"1"8O, "1"6O"1"2C"1"7O, "1"7O"1"2C"1"8O, "1"2C"1"8O_2 and "1"3C"1"8O_2 were newly measured. The status of the different databases (HITRAN, CDSD, variational calculations) in the important 2.3 µm transparency window is discussed. Possible improvements to correct evidenced deficiencies are suggested. - Highlights: • High sensitivity CRDS with a VECSEL in the 2.3 µm transparency window of CO_2. • Natural and "1"8O enriched CO_2 spectra recorded with

  4. Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.).

    Science.gov (United States)

    La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

    2009-06-01

    The effects of CO(2) enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO(2) concentration was elevated from 350 to 800 microl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO(2) concentration, N concentration, and CO(2)xN interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO(2). However, at 20 mmol N/L, elevated CO(2) had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO(2) concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO(2) concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO(2) condition.

  5. Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)*

    Science.gov (United States)

    La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

    2009-01-01

    The effects of CO2 enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO2 concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO2 concentration, N concentration, and CO2×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO2. However, at 20 mmol N/L, elevated CO2 had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO2 concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO2 concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO2 condition. PMID:19489111

  6. Stem juice production of the C4 sugarcane (Saccharum officinarum) is enhanced by growth at double-ambient CO2 and high temperature.

    Science.gov (United States)

    Vu, Joseph C V; Allen, Leon H

    2009-07-15

    Two cultivars of sugarcane (Saccharum officinarum cv. CP73-1547 and CP88-1508) were grown for 3 months in paired-companion, temperature-gradient, sunlit greenhouses under daytime [CO2] of 360 (ambient) and 720 (double ambient) micromol mol(-1) and at temperatures of 1.5 degrees C (near ambient) and 6.0 degrees C higher than outside ambient temperature. Leaf area and biomass, stem biomass and juice and CO2 exchange rate (CER) and activities of ribulose bisphosphate carboxylase-oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) of fully developed leaves were measured at harvest. On a main stem basis, leaf area, leaf dry weight, stem dry weight and stem juice volume were increased by growth at doubled [CO2] or high temperature. Such increases were even greater under combination of doubled [CO2]/high temperature. Plants grown at doubled [CO2]/high temperature combination averaged 50%, 26%, 84% and 124% greater in leaf area, leaf dry weight, stem dry weight and stem juice volume, respectively, compared with plants grown at ambient [CO2]/near-ambient temperature combination. In addition, plants grown at doubled [CO2]/high temperature combination were 2-3-fold higher in stem soluble solids than those at ambient [CO2]/near-ambient temperature combination. Although midday CER of fully developed leaves was not affected by doubled [CO2] or high temperature, plants grown at doubled [CO2] were 41-43% less in leaf stomatal conductance and 69-79% greater in leaf water-use efficiency, compared with plants grown at ambient [CO2]. Activity of PEPC was down-regulated 23-32% at doubled [CO2], while high temperature did not have a significant impact on this enzyme. Activity of Rubisco was not affected by growth at doubled [CO2], but was reduced 15-28% at high temperature. The increases in stem juice production and stem juice soluble solids concentration for sugarcane grown at doubled [CO2] or high temperature, or at doubled [CO2]/high temperature combination, were partially

  7. 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.

    1986-01-01

    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

  8. Seagrass ecosystem response to long-term high CO2 in a Mediterranean volcanic vent.

    Science.gov (United States)

    Apostolaki, Eugenia T; Vizzini, Salvatrice; Hendriks, Iris E; Olsen, Ylva S

    2014-08-01

    We examined the long-term effect of naturally acidified water on a Cymodocea nodosa meadow growing at a shallow volcanic CO2 vent in Vulcano Island (Italy). Seagrass and adjacent unvegetated habitats growing at a low pH station (pH = 7.65 ± 0.02) were compared with corresponding habitats at a control station (pH = 8.01 ± 0.01). Density and biomass showed a clear decreasing trend at the low pH station and the below- to above-ground biomass ratio was more than 10 times lower compared to the control. C content and δ(13)C of leaves and epiphytes were significantly lower at the low pH station. Photosynthetic activity of C. nodosa was stimulated by low pH as seen by the significant increase in Chla content of leaves, maximum electron transport rate and compensation irradiance. Seagrass community metabolism was intense at the low pH station, with significantly higher net community production, respiration and gross primary production than the control community, whereas metabolism of the unvegetated community did not differ between stations. Productivity was promoted by the low pH, but this was not translated into biomass, probably due to nutrient limitation, grazing or poor environmental conditions. The results indicate that seagrass response in naturally acidified conditions is dependable upon species and geochemical characteristics of the site and highlight the need for a better understanding of complex interactions in these environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. On the calculation of leakage rates from vessels filled with high density gaseous CO2 using pressure drop data

    International Nuclear Information System (INIS)

    George, A.F.

    1987-09-01

    This paper considers calculation methods to estimate leakage rates from pressure drop data from vessels filled with high pressure (40 bar) low temperature (25 0 C) CO 2 . It is essential to consider the non-ideality of CO 2 under these conditions if accurate results are to be obtained. There are two main areas where this is relevant: the first is the use of temperature measurements to adjust the measured pressure readings so that the effect of temperature fluctuations is eliminated. The second is in the conversion of the pressure drop data to volumetric leak rate. An example test is described in which it is shown that the CO 2 based temperature correction method improves the accuracy of the pressure drop estimate by about a factor of ten over using a perfect gas assumption and a factor of about 25 over not attempting to adjust the pressure at all. Also the flow rate obtained from assuming the gas was perfect was almost a factor of two too low. A method for scaling leakage rates to other temperature pressures and gases is also given brief consideration in this report. It is observed that the results of scaling are strongly dependent on the flow regime assumed and it is not possible to determine the flow regime from the pressure drop data. Consequently only upper and lower bounds to the scaled estimate can be quoted. (U.K.)

  10. Tropical Cyclones Cause CaCO3 Undersaturation of Coral Reef Seawater in a High-CO2 World

    Science.gov (United States)

    Manzello, D.; Enochs, I.; Carlton, R.; Musielewicz, S.; Gledhill, D. K.

    2013-12-01

    Ocean acidification is the global decline in seawater pH and calcium carbonate (CaCO3) saturation state (Ω) due to the uptake of anthropogenic CO2 by the world's oceans. Acidification impairs CaCO3 shell and skeleton construction by marine organisms. Coral reefs are particularly vulnerable, as they are constructed by the CaCO3 skeletons of corals and other calcifiers. We understand relatively little about how coral reefs will respond to ocean acidification in combination with other disturbances, such as tropical cyclones. Seawater carbonate chemistry data collected from two reefs in the Florida Keys before, during, and after Tropical Storm Isaac provide the most thorough data to-date on how tropical cyclones affect the seawater CO2-system of coral reefs. Tropical Storm Isaac caused both an immediate and prolonged decline in seawater pH. Aragonite saturation state was depressed by 1.0 for a full week after the storm impact. Based on current 'business-as-usual' CO2 emissions scenarios, we show that tropical cyclones with high rainfall and runoff can cause periods of undersaturation (Ω negatively impact the structural persistence of coral reefs over this century.

  11. Hydrothermal synthesis of NiCo2O4 nanowires/nitrogen-doped graphene for high-performance supercapacitor

    International Nuclear Information System (INIS)

    Yu, Mei; Chen, Jianpeng; Ma, Yuxiao; Zhang, Jingdan; Liu, Jianhua; Li, Songmei; An, Junwei

    2014-01-01

    Highlights: • NCO/NG composites were synthesized in a water–glycerol mixed solvent via hydrothermal treatment and subsequent calcination. • NiCo 2 O 4 nanowires are dispersed on NG nanosheets and the composite has porous structure. • The NCO/NG composite exhibits a high specific capacitance and long cycling performance. - Abstract: NiCo 2 O 4 nanowires/nitrogen-doped graphene (NCO/NG) composite materials were synthesized by hydrothermal treatment in a water–glycerol mixed solvent and subsequent thermal transformation. The obtained materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The electrochemical performance of the composites was evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectrum techniques. NiCo 2 O 4 nanowires are densely coated by nitrogen-doped graphene and the composite displays good electrochemical performance. The maximum specific capacitance of NCO/NG is 1273.13 F g −1 at 0.5 A g −1 in 6 M KOH aqueous solution, and it exhibits good capacity retention without noticeable degradation after 3000 cycles at 4 A g −1

  12. Predicting Effects of Corrosion Erosion of High Strength Steel Pipelines Elbow on CO2-Acetic Acid (HAc) Solution

    International Nuclear Information System (INIS)

    Asmara, Y. P.; Ismail, M. F.; Chui, L. Giok; Halimi, Jamiludin

    2016-01-01

    Simultaneously effect of erosion combined with corrosion becomes the most concern in oil and gas industries. It is due to the fast deterioration of metal as effects of solid particles mixed with corrosive environment. There are many corrosion software to investigate possible degradation mechanisms developed by researchers. They are using many combination factors of chemical reactions and physical process. However effects of CO 2 and acid on pipelines orientations are still remain uncovered in their simulation. This research will investigate combination effects of CO 2 and HAc on corrosion and erosion artificial environmental containing sands particles in 45°, 90° and 180° elbow pipelines. The research used theoretical calculations combined with experiments for verification. The main concerns are to investigate the maximum erosion corrosion rate and maximum shear stress at the surface. Methodology used to calculate corrosion rate are Linear Polarization Resistance (LPR) and weight loss. The results showed that at 45°, erosion rate is the more significant effects in contributing degradation of the metal. The effects of CO 2 and HAc gave significant effects when flow rate of the solution are high which reflect synergism effects of solid particles and those chemical compositions. (paper)

  13. Supercritical CO2 foaming of radiation crosslinked polypropylene/high-density polyethylene blend: Cell structure and tensile property

    Science.gov (United States)

    Yang, Chenguang; Xing, Zhe; Zhang, Mingxing; Zhao, Quan; Wang, Mouhua; Wu, Guozhong

    2017-12-01

    A blend of isotactic polypropylene (PP) with high-density polyethylene (HDPE) in different PP/HDPE ratios was irradiated by γ-ray to induce cross-linking and then foamed using supercritical carbon dioxide (scCO2) as a blowing agent. Radiation effect on the melting point and crystallinity were analyzed in detail. The average cell diameter and cell density were compared for PP/HDPE foams prepared under different conditions. The optimum absorbed dose for the scCO2 foaming of PP/HDPE in terms of foaming ability and cell structure was 20 kGy. Tensile measurements showed that the elongation at break and tensile strength at break of the crosslinked PP/HDPE foams were higher than the non-crosslinked ones. Of particular interest was the increase in the foaming temperature window from 4 ℃ for pristine PP to 8-12 ℃ for the radiation crosslinked PP/HDPE blends. This implies much easier handling of scCO2 foaming of crosslinked PP with the addition of HDPE.

  14. A sublimation technique for high-precision measurements of δ13CO2 and mixing ratios of CO2 and N2O from air trapped in ice cores

    Directory of Open Access Journals (Sweden)

    H. Fischer

    2011-07-01

    Full Text Available In order to provide high precision stable carbon isotope ratios (δ13CO2 or δ13C of CO2 from small bubbly, partially and fully clathrated ice core samples we developed a new method based on sublimation coupled to gas chromatography-isotope ratio mass spectrometry (GC-IRMS. In a first step the trapped air is quantitatively released from ~30 g of ice and CO2 together with N2O are separated from the bulk air components and stored in a miniature glass tube. In an off-line step, the extracted sample is introduced into a helium carrier flow using a minimised tube cracker device. Prior to measurement, N2O and organic sample contaminants are gas chromatographically separated from CO2. Pulses of a CO2/N2O mixture are admitted to the tube cracker and follow the path of the sample through the system. This allows an identical treatment and comparison of sample and standard peaks. The ability of the method to reproduce δ13C from bubble and clathrate ice is verified on different ice cores. We achieve reproducibilities for bubble ice between 0.05 ‰ and 0.07 ‰ and for clathrate ice between 0.05 ‰ and 0.09 ‰ (dependent on the ice core used. A comparison of our data with measurements on bubble ice from the same ice core but using a mechanical extraction device shows no significant systematic offset. In addition to δ13C, the CO2 and N2O mixing ratios can be volumetrically derived with a precision of 2 ppmv and 8 ppbv, respectively.

  15. Investigations and researches on CO2 balance in a high-temperature carbon dioxide separation technology; Nisanka tanso koon bunri gijutsu ni okeru CO2 balance ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    With an objective to select a promising process by comparing application environments and effectiveness of a high-temperature carbon dioxide separation, recovery and re-utilization technology with other methods, investigations were performed on reducible amount of carbon dioxide discharge by using material balance and system introduction. A large number of chemical and physical technologies are being developed for the separation and refining methods. This paper discusses the technologies for their application to iron and steel making, oil refining, and petrochemical industries, the so-called heavy and large product industries. As a possibility of utilizing the high-temperature separated CO2 in iron and steel making, an investigation was given on the direct iron ore smelting reduction process. It would be unreasonable to use CO2 in oil refining as a substitute to air to regenerate a catalytic decomposition and reformation catalyst because of decline in the catalytic activity. A discussion was given on a case to replace steam with CO2 in steam reformation and pyrolysis of hydrocarbons. The discussion requires the objective to be focused on such items as C/H ratio at a reformer outlet and relationship of balance in decomposition products. The C1 chemical and others were reviewed to search possibilities for their use as raw materials of chemicals used in chemical industries. Possibilities were discussed to fix high-temperature CO2 into peridotite and serpentine. 42 refs., 32 figs., 11 tabs.

  16. High-throughput automated parallel evaluation of zinc-based catalysts for the copolymerization of CHO and CO2 to polycarbonates

    NARCIS (Netherlands)

    Meerendonk, van W.J.; Duchateau, R.; Koning, C.E.; Gruter, G.J.M.

    2004-01-01

    Copolymn. of CO2 and oxiranes using a high-pressure autoclave typically allows one expt. per reactor per day. A high-throughput parallel setup was developed and validated for the copolymn. of CO2 and cyclohxene oxide (CHO) with two b-diiminato zinc complexes. The catalyst activity is affected by

  17. 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

    2014-07-01

    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

  18. Incorporation of Mg, Sr, Ba, U, and B in High-Mg Calcite Benthic Foraminifers Cultured Under Controlled pCO2

    Science.gov (United States)

    Not, C.; Thibodeau, B.; Yokoyama, Y.

    2018-01-01

    Measurement of elemental ratios (E/Ca) has been performed in two symbiont-bearing species of high-Mg calcite benthic foraminifers (hyaline, Baculogypsina sphaerulata and porcelaneous, Amphisorus hemprichii), cultured under five pCO2 levels, representing preindustrial, modern, and three predicted future values. E/Ca ratios were analyzed by Laser Ablation coupled with Inductively Coupled Plasma Mass Spectrometer (LA-ICP-MS). We measured several E/Ca, such as Mg/Ca, Sr/Ca, Ba/Ca, U/Ca, and B/Ca simultaneously. We observed that high-Mg calcite benthic foraminifers possess higher E/Ca than low-Mg calcite foraminifers, irrespective of their calcification mode (hyaline or porcelaneous). In both modes of calcification, Mg, Sr, Ba, U, and B incorporation could be controlled by Rayleigh fractionation. However, more data are needed to validate and quantify the relative importance of this process and closely investigate the presence/absence of other mechanism. Therefore, it highlights the need for a multielemental approach when looking at trace element incorporation. Finally, no significant relationship was observed between the different ratios and the pCO2 of the water, suggesting that none of the Mg/Ca, Sr/Ca, Ba/Ca, U/Ca, and B/Ca is sensitive to bottom water pCO2 or pH for these species.

  19. Effects of CO2 Concentration on Leaf Photosynthesis and Stomatal Conductance of Potatoes Grown Under Different Irradiance Levels and Photoperiods

    Science.gov (United States)

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

    2012-01-01

    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

  20. Diversity and stability of coral endolithic microbial communities at a naturally high pCO2 reef.

    Science.gov (United States)

    Marcelino, Vanessa Rossetto; Morrow, Kathleen M; van Oppen, Madeleine J H; Bourne, David G; Verbruggen, Heroen

    2017-10-01

    The health and functioning of reef-building corals is dependent on a balanced association with prokaryotic and eukaryotic microbes. The coral skeleton harbours numerous endolithic microbes, but their diversity, ecological roles and responses to environmental stress, including ocean acidification (OA), are not well characterized. This study tests whether pH affects the diversity and structure of prokaryotic and eukaryotic algal communities associated with skeletons of Porites spp. using targeted amplicon (16S rRNA gene, UPA and tufA) sequencing. We found that the composition of endolithic communities in the massive coral Porites spp. inhabiting a naturally high pCO 2 reef (avg. pCO 2 811 μatm) is not significantly different from corals inhabiting reference sites (avg. pCO 2 357 μatm), suggesting that these microbiomes are less disturbed by OA than previously thought. Possible explanations may be that the endolithic microhabitat is highly homeostatic or that the endolithic micro-organisms are well adapted to a wide pH range. Some of the microbial taxa identified include nitrogen-fixing bacteria (Rhizobiales and cyanobacteria), algicidal bacteria in the phylum Bacteroidetes, symbiotic bacteria in the family Endozoicomoniaceae, and endolithic green algae, considered the major microbial agent of reef bioerosion. Additionally, we test whether host species has an effect on the endolithic community structure. We show that the endolithic community of massive Porites spp. is substantially different and more diverse than that found in skeletons of the branching species Seriatopora hystrix and Pocillopora damicornis. This study reveals highly diverse and structured microbial communities in Porites spp. skeletons that are possibly resilient to OA. © 2017 John Wiley & Sons Ltd.

  1. Determining the high variability of pCO2 and pO2 in the littoral zone of a subtropical coastal lake

    Directory of Open Access Journals (Sweden)

    Denise Tonetta

    2014-09-01

    Full Text Available The aquatic metabolism comprises production and mineralization of organic matter through biological processes, such as primary production and respiration that can be estimated by gases concentration in the water column. AIM: The study aimed to assess the temporal variability of pCO2 and pO2 in the littoral zone of a subtropical coastal lake. Our hypotheses are i high variability in meteorological conditions, such as temperature and light, drive the high variability in pCO2 and pO2, and ii the lake is permanently heterotrophic due to the low phosphorus concentration. METHODS: We estimated pCO2 from pH-alkalinity method, and pO2 from dissolved oxygen concentration and water temperature measured in free-water during 24 hours in the autumn, winter, spring and summer. RESULTS: Our findings showed that limnological variables had low temporal variability, while the meteorological variables and pCO2 presented a high coefficient of variation, which is representative of each climatic season. In autumn and winter, it was recorded that the lake was supersaturated in CO2 relative to the atmosphere, while in spring and summer CO2 concentration was below the concentration found in the atmosphere. Over 24 hours, pCO2 also showed high variability, with autumn presenting higher concentration during the night when compared to daytime. Water temperature and chlorophyll a were negatively correlated with pCO2, while pO2 was positively correlated with wind and light. CONCLUSION: Agreeing with our first hypothesis, pCO2 showed an expressive temporal variation in a subtropical lake associated to the high variability in meteorological conditions. On the other hand, our second hypothesis was not confirmed, since Peri Lake exported CO2 to the atmosphere in some periods and in others, CO2 was removed from the atmosphere.

  2. Toward an estimation of daily european CO2 fluxes at high spatial resolution by inversion of atmospheric transport

    International Nuclear Information System (INIS)

    Carouge, C.

    2006-04-01

    Since the end of the 1980's, measurements of atmospheric carbon dioxide have been used to estimate global and regional fluxes of CO 2 . This is possible because CO 2 concentration variation is directly linked to flux variation by atmospheric transport. We can find the spatial and temporal distribution of fluxes from concentration measurements by 'inverting' the atmospheric transport. Until recently, most CO 2 inversions have used monthly mean CO 2 atmospheric concentration measurements to infer monthly fluxes. Considering the sparseness of the global CO 2 measurement network, fluxes were a priori aggregated on sub-continental regions and distributed on a fixed spatial pattern within these regions. Only one flux coefficient per month for each region was optimized. With this strong constraint, estimated fluxes can be biased by non-perfect distribution of fluxes within each region (aggregation error). Therefore, flux estimation at model resolution is being developed where the hard constraint of a fixed distribution within a region is replaced by a soft constraint of covariances between flux uncertainties. The use of continuous observations from an increasing number of measurement sites offers a new challenge for inverse modelers. We investigate the use of daily averaged observations to infer daily CO 2 fluxes at model resolution over Europe. We have developed a global synthesis Bayesian inversion to invert daily fluxes at model resolution (50 x 50 km over Europe) from daily averaged CO 2 concentrations. We have obtained estimated fluxes for the year 2001 over Europe using the 10 European continuous sites from the AEROCARB network. The global atmospheric model LMDZt is used with a nested grid over Europe. It is necessary to add a priori spatial and temporal correlations between flux errors to constrain the Bayesian inversion. We present the impact on estimated fluxes of three different spatial correlations based on distance between pixels, climate and vegetation

  3. Highly Efficient Method for the Synthesis of Activated Mesoporous Biocarbons with Extremely High Surface Area for High-Pressure CO2 Adsorption.

    Science.gov (United States)

    Singh, Gurwinder; Lakhi, Kripal S; Kim, In Young; Kim, Sungho; Srivastava, Prashant; Naidu, Ravi; Vinu, Ajayan

    2017-09-06

    A simple and efficient way to synthesize activated mesoporous biocarbons (AMBs) with extremely high BET surface area and large pore volume has been achieved for the first time through a simple solid state activation of freely available biomass, Arundo donax, with zinc chloride. The textural parameters of the AMB can easily be controlled by varying the activation temperature. It is demonstrated that the mesoporosity of AMB can be finely tuned with a simple adjustment of the amount of activating agent. AMB with almost 100% mesoporosity can be achieved using the activating agent and the biomass ratio of 5 and carbonization at 500 °C. Under the optimized conditions, AMB with a BET surface area of 3298 m 2 g -1 and a pore volume of 1.9 cm 3 g -1 can be prepared. While being used as an adsorbent for CO 2 capture, AMB registers an impressively high pressure CO 2 adsorption capacity of 30.2 mmol g -1 at 30 bar which is much higher than that of activated carbon (AC), multiwalled carbon nanotubes (MWCNTs), highly ordered mesoporous carbons, and mesoporous carbon nitrides. AMB also shows high stability with excellent regeneration properties under vacuum and temperatures of up to 250 °C. These impressive textural parameters and high CO 2 adsorption capacity of AMB clearly reveal its potential as a promising adsorbent for high-pressure CO 2 capture and storage application. Also, the simple one-step synthesis strategy outlined in this work would provide a pathway to generate a series of novel mesoporous activated biocarbons from different biomasses.

  4. Constructing robust and highly-selective hydrogel membranes by bioadhesion-inspired method for CO 2 separation

    KAUST Repository

    Wu, Yingzhen; Zhou, Tiantian; Wu, Hong; Fu, Weixian; Wang, Xinru; Wang, Shaofei; Yang, Leixin; Wu, Xingyu; Ren, Yanxiong; Jiang, Zhongyi; Wang, Baoyi

    2018-01-01

    -size gas molecules and thus enhancing the CO2/CH4 selectivity. Moreover, the abundant amine groups from PDA nanoaggregates could facilitate CO2 transport. The optimized hybrid hydrogel membrane exhibited CO2/CH4 selectivity of 43.2, which was 43.85% higher

  5. One-step synthesis of dimethyl ether from the gas mixture containing CO2 with high space velocity

    International Nuclear Information System (INIS)

    Chen, Wei-Hsin; Lin, Bo-Jhih; Lee, How-Ming; Huang, Men-Han

    2012-01-01

    Highlights: ► A bifunctional catalyst for DME synthesis is prepared using a coprecipitation method. ► The DME synthesis from syngas at a high space velocity of is investigated. ► The reaction is dominated by chemical kinetics at lower reaction temperatures. ► Thermodynamic equilibrium governs the reaction at higher temperatures. ► 0.2 g of ZSM5 is sufficient to be blended with 1 g of the catalyst for DME synthesis. -- Abstract: Dimethyl ether (DME) has been considered as a potential hydrogen carrier used in fuel cells; it can also be consumed as a diesel substitute or chemicals. To develop the technique of DME synthesis, a bifunctional Cu–ZnO–Al 2 O 3 /ZSM5 catalyst is prepared using a coprecipitation method. The reaction characteristics of DME synthesis from syngas at a high space velocity of 15,000 mL (g cat h) −1 are investigated and the effects of reaction temperature, pressure, CO 2 concentration and ZSM5 amount on the synthesis are taken into account. The results suggest that an increase in CO 2 concentration in the feed gas substantially decreases the DME formation. The optimum reaction temperature always occurs at 225 °C, regardless of what the pressure is. It is thus recognized that the DME synthesis is governed by two different mechanisms when the reaction temperature varies. At lower reaction temperatures ( 225 °C). For the CO 2 content of 5 vol.% and the pressure of 40 atm, the maximum DME yield is 1.89 g (g cat h) −1 . It is also found that 0.2 g of ZSM5 is sufficient to be blended with 1 g of the catalyst for DME synthesis.

  6. Compact high-speed MWIR spectrometer applied to monitor CO2 exhaust dynamics from a turbojet engine

    Science.gov (United States)

    Linares-Herrero, R.; Vergara, G.; Gutiérrez Álvarez, R.; Fernández Montojo, C.; Gómez, L. J.; Villamayor, V.; Baldasano Ramírez, A.; Montojo, M. T.; Archilla, V.; Jiménez, A.; Mercader, D.; González, A.; Entero, A.

    2013-05-01

    Dfgfdg Due to international environmental regulations, aircraft turbojet manufacturers are required to analyze the gases exhausted during engine operation (CO, CO2, NOx, particles, unburned hydrocarbons (aka UHC), among others).Standard procedures, which involve sampling the gases from the exhaust plume and the analysis of the emissions, are usually complex and expensive, making a real need for techniques that allow a more frequent and reliable emissions measurements, and a desire to move from the traditional gas sampling-based methods to real time and non-intrusive gas exhaust analysis, usually spectroscopic. It is expected that the development of more precise and faster optical methods will provide better solutions in terms of performance/cost ratio. In this work the analysis of high-speed infrared emission spectroscopy measurements of plume exhaust are presented. The data was collected during the test trials of commercial engines carried out at Turbojet Testing Center-INTA. The results demonstrate the reliability of the technique for studying and monitoring the dynamics of the exhausted CO2 by the observation of the infrared emission of hot gases. A compact (no moving parts), high-speed, uncooled MWIR spectrometer was used for the data collection. This device is capable to register more than 5000 spectra per second in the infrared band ranging between 3.0 and 4.6 microns. Each spectrum is comprised by 128 spectral subbands with aband width of 60 nm. The spectrometer operated in a passive stand-off mode and the results from the measurements provided information of both the dynamics and the concentration of the CO2 during engine operation.

  7. Activity Based Carboning (ABCO2). Automatic calculation of CO2 emission at consignment level; Activity Based Carboning (ABCO2). Automatische berekening van de CO2-uitstoot op zending niveau

    Energy Technology Data Exchange (ETDEWEB)

    Den Boer, L.C.

    2012-11-15

    In a collaborative effort with the CAPE group, CE Delft has developed ABCO2: a tool for calculating the carbon emissions of logistics operations at the level of individual consignments. The tool can be used during order make-up to indicate the CO2 emissions of available alternatives. To this end the user defines a network, providing details on vehicle fleet, logistic characteristics and transhipment locations. By filling in order data over an extended period, the effect of opting for a different modality or bundling shipments can be quantified. CE Delft helped develop the calculation methodology for the tool and provided the emission indices used in the model, in which relevant existing standards have also been incorporated [Dutch] Samen met CAPE groep heeft CE Delft de tool ABCO2 ontwikkeld. Met deze tool is het mogelijk om op orderniveau de emissies van logistieke activiteiten te berekenen. De tool wordt gebruikt tijdens het orderproces, en geeft bij het aanmaken van een order de CO2 uitstoot van verschillende alternatieven weer. De gebruiker richt zelf een netwerk in, en detailleert dit door een wagenpark, logistieke karakteristieken, en locaties voor overslag te definiëren. Met ordergegevens over langere tijd kan ook het effect van keuzes voor een andere modaliteit, of het bundelen van zendingen gekwantificeerd worden. CE Delft heeft meegeholpen om de rekenmethodiek van de tool te ontwikkelen en heeft emissiekentallen aangeleverd, die in het model zijn opgenomen. Bij de ontwikkeling van het model is rekening gehouden met de beschikbare standaarden hiervoor.

  8. Elevated CO2 enhances biological contributions to elevation change in coastal wetlands by offsetting stressors associated with sea-level rise

    Science.gov (United States)

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

    2009-01-01

    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

  9. 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

    2015-01-01

    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

  10. CARBON AND NUTRIENT FLOW THROUGH MULTIPLE TROPHIC LEVELS IN A CO2-ENRICHED SOUTHERN PINE FOREST COMMUNITY - FINAL TECHNICAL REPORT

    Science.gov (United States)

    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 ...

  11. Hierarchical chestnut-like MnCo2O4 nanoneedles grown on nickel foam as binder-free electrode for high energy density asymmetric supercapacitors

    Science.gov (United States)

    Hui, Kwun Nam; Hui, Kwan San; Tang, Zikang; Jadhav, V. V.; Xia, Qi Xun

    2016-10-01

    Hierarchical chestnut-like manganese cobalt oxide (MnCo2O4) nanoneedles (NNs) are successfully grown on nickel foam using a facile and cost-effective hydrothermal method. High resolution TEM image further verifies that the chestnut-like MnCo2O4 structure is assembled by numerous 1D MnCo2O4 nanoneedles, which are formed by numerous interconnected MnCo2O4 nanoparticles with grain diameter of ∼10 nm. The MnCo2O4 electrode exhibits high specific capacitance of 1535 F g-1 at 1 A g-1 and good rate capability (950 F g-1 at 10 A g-1) in a 6 M KOH electrolyte. An asymmetric supercapacitor is fabricated using MnCo2O4 NNs on Ni foam (MnCo2O4 NNs/NF) as the positive electrode and graphene/NF as the negative electrode. The device shows an operation voltage of 1.5 V and delivers a high energy density of ∼60.4 Wh kg-1 at a power density of ∼375 W kg-1. Moreover, the device exhibits an excellent cycling stability of 94.3% capacitance retention after 12000 cycles at 30 A g-1. This work demonstrates that hierarchical chestnut-like MnCo2O4 NNs could be a promising electrode for the high performance energy storage devices.

  12. The global pyrogenic carbon cycle and its impact on the level of atmospheric CO2 over past and future centuries.

    Science.gov (United States)

    Landry, Jean-Sébastien; Matthews, H Damon

    2017-08-01

    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.

  13. Reducing oyster-associated bacteria levels using supercritical fluid CO2 as an agent of warm pasteurization.

    Science.gov (United States)

    Meujo, Damaris A F; Kevin, Dion A; Peng, Jiangnan; Bowling, John J; Liu, Jianping; Hamann, Mark T

    2010-03-31

    An innovative approach to Post-Harvest Processing (PHP) of oysters is introduced focusing on the effects of supercritical carbon dioxide (scCO(2)) on bacterial contaminants trapped in the digestive system of oysters. Oysters were exposed to scCO(2) under two conditions: (1) 100 bar and 37 degrees C for 30 min and (2) 172 bar and 60 degrees C for 60 min. Using FDA standard guidelines for food analysis, variations in the Aerobic Plate Count (APC) were assessed. It was established that exposing oysters to CO(2) at 100 bar and 37 degrees C for 30 min and at 172 bar and 60 degrees C for 60 min induced 2-log and 3-log reductions in the APC respectively. The decrease in the microbial load as a result of treatment with scCO(2) was found to be significant (P=0.002). A release of adductor muscles from the shell was noted in oysters treated at 172 bar and 60 degrees C for 60 min; this was not the case for oysters treated at 100 bar and 37 degrees C for 30 min. A blind study allowing sensory analysis of treated vs. untreated oysters was also completed and no significant change in the physical appearance, smell, or texture was recorded. In this paper, we also report the effect of scCO(2) on several bacterial isolates, including a referenced ATCC strain of a non-pathogenic Vibrio (Vibrio fischeri) as well as several other bacterial isolates cultured from oyster' tissues and found to share biochemical features common to pathogenic Vibrio strains. A complete inactivation (minimum 7-log reduction) was achieved with these latter bacterial isolates. A 6-log reduction was observed with V. fischeri. Copyright 2009 Elsevier B.V. All rights reserved.

  14. Asymmetric Hollow Fiber Membranes for Separation of CO 2 from Hydrocarbons and Fluorocarbons at High-Pressure Conditions Relevant to C 2 F 4 Polymerization

    KAUST Repository

    Kosuri, Madhava R.

    2009-12-02

    Separation of high-pressure carbon dioxide from fluorocarbons is important for the production of fluoropolymers such as poly(tetrafluoroethylene). Typical polymeric membranes plasticize under high CO2 partial pressure conditions and fail to provide adequate selective separations. Torlon, a polyamide-imide polymer, with the ability to form interchain hydrogen bonding, is shown to provide stability against aggressive CO2 plasticization. Torlon membranes in the form of asymmetric hollow fibers (the most productive form of membranes) are considered for an intended separation of CO 2/C2F4. To avoid safety issues with tetrafluoroethylene (C2F4), which could detonate under testing conditions, safer surrogate mixtures (C2H2F 2 and C2H4) are considered in this paper. Permeation measurements (at 35 °C) indicate that the Torlon membranes are not plasticized even up to 1250 psi of CO2. The membranes provide mixed gas CO2/C2H2F2 and CO 2/C2H4 selectivities of 100 and 30, respectively, at 1250 psi partial pressures of CO2. On the basis of the measured separation performances of CO2/C2H 2F2 and CO2/C2H4 mixtures, the selectivity of the CO2/C2F4 mixture is expected to be greater than 100. Long-term stability studies indicate that the membranes provide stable separations over a period of 5 days at 1250 psi partial pressures of CO2, thereby making the membrane approach attractive. © 2009 American Chemical Society.

  15. Asymmetric Hollow Fiber Membranes for Separation of CO 2 from Hydrocarbons and Fluorocarbons at High-Pressure Conditions Relevant to C 2 F 4 Polymerization

    KAUST Repository

    Kosuri, Madhava R.; Koros, William J.

    2009-01-01

    Separation of high-pressure carbon dioxide from fluorocarbons is important for the production of fluoropolymers such as poly(tetrafluoroethylene). Typical polymeric membranes plasticize under high CO2 partial pressure conditions and fail to provide adequate selective separations. Torlon, a polyamide-imide polymer, with the ability to form interchain hydrogen bonding, is shown to provide stability against aggressive CO2 plasticization. Torlon membranes in the form of asymmetric hollow fibers (the most productive form of membranes) are considered for an intended separation of CO 2/C2F4. To avoid safety issues with tetrafluoroethylene (C2F4), which could detonate under testing conditions, safer surrogate mixtures (C2H2F 2 and C2H4) are considered in this paper. Permeation measurements (at 35 °C) indicate that the Torlon membranes are not plasticized even up to 1250 psi of CO2. The membranes provide mixed gas CO2/C2H2F2 and CO 2/C2H4 selectivities of 100 and 30, respectively, at 1250 psi partial pressures of CO2. On the basis of the measured separation performances of CO2/C2H 2F2 and CO2/C2H4 mixtures, the selectivity of the CO2/C2F4 mixture is expected to be greater than 100. Long-term stability studies indicate that the membranes provide stable separations over a period of 5 days at 1250 psi partial pressures of CO2, thereby making the membrane approach attractive. © 2009 American Chemical Society.

  16. Elevated CO2 plus chronic warming reduce nitrogen uptake and levels or activities of nitrogen-uptake and -assimilatory proteins in tomato roots.

    Science.gov (United States)

    Jayawardena, Dileepa M; Heckathorn, Scott A; Bista, Deepesh R; Mishra, Sasmita; Boldt, Jennifer K; Krause, Charles R

    2017-03-01

    Atmospheric CO 2 enrichment is expected to often benefit plant growth, despite causing global warming and nitrogen (N) dilution in plants. Most plants primarily procure N as inorganic nitrate (NO 3 - ) or ammonium (NH 4 + ), using membrane-localized transport proteins in roots, which are key targets for improving N use. Although interactive effects of elevated CO 2 , chronic warming and N form on N relations are expected, these have not been studied. In this study, tomato (Solanum lycopersicum) plants were grown at two levels of CO 2 (400 or 700 ppm) and two temperature regimes (30 or 37°C), with NO 3 - or NH 4 + as the N source. Elevated CO 2 plus chronic warming severely inhibited plant growth, regardless of N form, while individually they had smaller effects on growth. Although %N in roots was similar among all treatments, elevated CO 2 plus warming decreased (1) N-uptake rate by roots, (2) total protein concentration in roots, indicating an inhibition of N assimilation and (3) shoot %N, indicating a potential inhibition of N translocation from roots to shoots. Under elevated CO 2 plus warming, reduced NO 3 - -uptake rate per g root was correlated with a decrease in the concentration of NO 3 - -uptake proteins per g root, reduced NH 4 + uptake was correlated with decreased activity of NH 4 + -uptake proteins and reduced N assimilation was correlated with decreased concentration of N-assimilatory proteins. These results indicate that elevated CO 2 and chronic warming can act synergistically to decrease plant N uptake and assimilation; hence, future global warming may decrease both plant growth and food quality (%N). © 2016 Scandinavian Plant Physiology Society.

  17. Changes in the salinity tolerance of sweet pepper plants as affected by nitrogen form and high CO2 concentration.

    Science.gov (United States)

    Piñero, María C; Pérez-Jiménez, Margarita; López-Marín, Josefa; Del Amor, Francisco M

    2016-08-01

    The assimilation and availability of nitrogen in its different forms can significantly affect the response of primary productivity under the current atmospheric alteration and soil degradation. An elevated CO2 concentration (e[CO2]) triggers changes in the efficiency and efficacy of photosynthetic processes, water use and product yield, the plant response to stress being altered with respect to ambient CO2 conditions (a[CO2]). Additionally, NH4(+) has been related to improved plant responses to stress, considering both energy efficiency in N-assimilation and the overcoming of the inhibition of photorespiration at e[CO2]. Therefore, the aim of this work was to determine the response of sweet pepper plants (Capsicum annuum L.) receiving an additional supply of NH4(+) (90/10 NO3(-)/NH4(+)) to salinity stress (60mM NaCl) under a[CO2] (400μmolmol(-1)) or e[CO2] (800μmolmol(-1)). Salt-stressed plants grown at e[CO2] showed DW accumulation similar to that of the non-stressed plants at a[CO2]. The supply of NH4(+) reduced growth at e[CO2] when salinity was imposed. Moreover, NH4(+) differentially affected the stomatal conductance and water use efficiency and the leaf Cl(-), K(+), and Na(+) concentrations, but the extent of the effects was influenced by the [CO2]. An antioxidant-related response was prompted by salinity, the total phenolics and proline concentrations being reduced by NH4(+) at e[CO2]. Our results show that the effect of NH4(+) on plant salinity tolerance should be globally re-evaluated as e[CO2] can significantly alter the response, when compared with previous studies at a[CO2]. Copyright © 2016 Elsevier GmbH. All rights reserved.

  18. Forecasting global atmospheric CO2

    International Nuclear Information System (INIS)

    Agusti-Panareda, A.; Massart, S.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Engelen, R.; Jones, L.; Peuch, V.H.; Chevallier, F.; Ciais, P.; Paris, J.D.; Sherlock, V.

    2014-01-01

    A new global atmospheric carbon dioxide (CO 2 ) real-time forecast is now available as part of the preoperational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO 2 forecasting system is that the land surface, including vegetation CO 2 fluxes, is modelled online within the IFS. Other CO 2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO 2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO 2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO 2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO 2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO 2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO 2 fluxes also lead to accumulating errors in the CO 2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO 2 fluxes compared to total optimized fluxes and the atmospheric CO 2 compared to observations. The largest biases in the atmospheric CO 2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO 2 analyses based on the assimilation of CO 2 products retrieved from satellite

  19. Greenhouse gas (CO2 and CH4) emissions from a high altitude hydroelectric reservoir in the tropics (Riogrande II, Colombia)

    Science.gov (United States)

    Guérin, Frédéric; Leon, Juan

    2015-04-01

    Tropical hydroelectric reservoirs are considered as very significant source of methane (CH4) and carbon dioxide (CO2), especially when flooding dense forest. We report emissions from the Rio Grande II Reservoir located at 2000 m.a.s.l. in the Colombian Andes. The dam was built at the confluence of the Rio Grande and Rio Chico in 1990. The reservoir has a surface of 12 km2, a maximum depth of 40m and a residence time of 2.5 month. Water quality (temperature, oxygen, pH, conductivity), nitrate, ammonium, dissolved and particulate organic carbon (DOC and POC), CO2 and CH4 were monitored bi-monthly during 1.5 year at 9 stations in the reservoir. Diffusive fluxes of CO2 and CH4 and CH4 ebullition were measured at 5 stations. The Rio grande II Reservoir is weakly stratified thermally with surface temperature ranging from 20 to 24°C and a constant bottom temperature of 18°C. The reservoir water column is well oxygenated at the surface and usually anoxic below 10m depth. At the stations close to the tributaries water inputs, the water column is well mixed and oxygenated from the surface to the bottom. As reported for other reservoirs located in "clear water" watersheds, the concentrations of nutrients are low (NO3-10 mmol m-2 d-1) were observed during the dry season. Close to the tributaries water inputs where the water column is well mixed, the average diffusive flux is 8 mmol m-2 d-1. CH4 ebullition was 3.5 mmol m-2 d-1 and no ebullition was observed for a water depth higher than 5m. The zone under the influence of the water inputs from tributaries represents 25% of the surface of the reservoir but contributed half of total CH4 emissions from the reservoir (29MgC month-1). Ebullition contributed only to 12% of total CH4 emissions over a year but it contributed up to 60% during the dry season. CH4 emissions from the Rio Grande Reservoir contributed 30% of the total GHG emissions (38GgCO2eq y-1). Overall, this study show that the majority of CH4 emissions from this

  20. Recent Results in High Power CO2-Laser Cutting for Shipbuilding Industry

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Juhl, Thomas Winther; Nielsen, Jakob Skov

    2003-01-01

    In 1997 a high power laser cutting and welding test facility was established at the Danish shipyard Odense Steel Shipyard (OSS). Research and development projects were initiated in order to establish the basis for applying the full power of the laser for laser-cutting, by developing mirror based...

  1. Methanol from coal without CO2 production via the modular high temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Schleicher, R.W. Jr.; Engler, D.; Labar, M.P.

    1992-01-01

    Displacement options for petroleum fuels include natural gas (compressed or liquified), synthetic gasoline, biomass fuels, electric vehicles, hydrogen, and methanol. This paper reports that although no alternative meets all the desired characteristics of economics, environmental impact, supply logistics, and vehicle technology, methanol has often been cited as a good compromise and is perhaps the best coal derived fuel. The main criticism leveled at methanol is whether it can be produced economically in sufficient quantities to significantly displace petroleum-derived fuels. Although methanol can be manufactured from biomass, natural gas or coal feedstocks, only coal offers the potential for a substantial long term indigenous U.S. feedstock

  2. Low temperature and short-term high-CO2 treatment in postharvest storage of table grapes at two maturity stages: Effects on transcriptome profiling.

    Directory of Open Access Journals (Sweden)

    Raquel Rosales

    2016-07-01

    Full Text Available Table grapes (Vitis vinifera cv. Cardinal are highly perishable and their quality deteriorates during postharvest storage at low temperature mainly because of sensitivity to fungal decay and senescence of rachis. The application of a 3-day CO2 treatment (20 kPa CO2 + 20 kPa O2 + 60 kPa N2 at 0ºC reduced total decay and retained fruit quality in early and late-harvested table grapes during postharvest storage. In order to study the transcriptional responsiveness of table grapes to low temperature and high CO2 levels in the first stage of storage and how the maturity stage affect these changes, we have performed a comparative large-scale transcriptional analysis using the custom-made GrapeGen GeneChip®. In the first stage of storage, low temperature led to a significantly intense change in grape skin transcriptome irrespective of fruit maturity, although there were different changes within each stage. In the case of CO2 treated samples, in comparison to fruit at time zero, only slight differences were observed. Functional enrichment analysis revealed that major modifications in the transcriptome profile of early- and late-harvested grapes stored at 0ºC are linked to biotic and abiotic stress-responsive terms. However, in both cases there is a specific reprogramming of the transcriptome during the first stage of storage at 0ºC in order to withstand the cold stress. Thus, genes involved in gluconeogenesis, photosynthesis, mRNA translation and lipid transport were up-regulated in the case of early-harvested grapes, and genes related to protein folding stability and intracellular membrane trafficking in late-harvested grapes. The beneficial effect of high CO2 treatment maintaining table grape quality seems to be an active process requiring the induction of several transcription factors and kinases in early-harvested grapes, and the activation of processes associated to the maintenance of energy in late-harvested grapes.

  3. Low Temperature and Short-Term High-CO2 Treatment in Postharvest Storage of Table Grapes at Two Maturity Stages: Effects on Transcriptome Profiling.

    Science.gov (United States)

    Rosales, Raquel; Romero, Irene; Fernandez-Caballero, Carlos; Escribano, M Isabel; Merodio, Carmen; Sanchez-Ballesta, M Teresa

    2016-01-01

    Table grapes (Vitis vinifera cv. Cardinal) are highly perishable and their quality deteriorates during postharvest storage at low temperature mainly because of sensitivity to fungal decay and senescence of rachis. The application of a 3-day CO2 treatment (20 kPa CO2 + 20 kPa O2 + 60 kPa N2) at 0°C reduced total decay and retained fruit quality in early and late-harvested table grapes during postharvest storage. In order to study the transcriptional responsiveness of table grapes to low temperature and high CO2 levels in the first stage of storage and how the maturity stage affect these changes, we have performed a comparative large-scale transcriptional analysis using the custom-made GrapeGen GeneChip®. In the first stage of storage, low temperature led to a significantly intense change in grape skin transcriptome irrespective of fruit maturity, although there were different changes within each stage. In the case of CO2 treated samples, in comparison to fruit at time zero, only slight differences were observed. Functional enrichment analysis revealed that major modifications in the transcriptome profile of early- and late-harvested grapes stored at 0°C are linked to biotic and abiotic stress-responsive terms. However, in both cases there is a specific reprogramming of the transcriptome during the first stage of storage at 0°C in order to withstand the cold stress. Thus, genes involved in gluconeogenesis, photosynthesis, mRNA translation and lipid transport were up-regulated in the case of early-harvested grapes, and genes related to protein folding stability and intracellular membrane trafficking in late-harvested grapes. The beneficial effect of high CO2 treatment maintaining table grape quality seems to be an active process requiring the induction of several transcription factors and kinases in early-harvested grapes, and the activation of processes associated to the maintenance of energy in late-harvested grapes.

  4. Photosynthesis and growth at high day temperatures in a CO2 enriched atmosphere

    OpenAIRE

    Hückstädt, Arne Björn

    2013-01-01

    Increasing energy prices have led to the attempt of energy saving and are one of the main research areas in greenhouse plant production. Technical disintegration has been developed, and the greenhouse concept ‘Closed/Semi-Closed Greenhouse’ was introduced. The idea of this concept is to reduce energy consumption by cooling the greenhouse under high light intensities, and storing the heat in an underground aquifer to be regained for heating. In order to improve the efficiency of the concept th...

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

    Science.gov (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

    2017-01-01

    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.

  6. 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

    2014-08-01

    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.

  7. Effects of high CO2 on growth, photosynthesis and respiration of Phymatolithon calcareum

    OpenAIRE

    Shulika, Al'ona

    2014-01-01

    Dissertação de mestrado, Biologia Marinha, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2014 Mäerl is a collective term for different species of non-jointed coralline red algae. Phymatolithon calcareum is a mäerl species which is widely distributed in Europe, from Norway to the Mediterranean including Portugal. In Portugal it is mostly present in the south along the coast of Algarve. This species forms highly productive marine benthic systems and is considered a priority sp...

  8. Potential role of pectate lyase and Ca(2+) in the increase in strawberry fruit firmness induced by short-term treatment with high-pressure CO2.

    Science.gov (United States)

    Wang, Mao Hua; Kim, Jin Gook; Ahn, Sun Eun; Lee, Ah Youn; Bae, Tae Min; Kim, Deu Re; Hwang, Yong Soo

    2014-04-01

    Postharvest treatment with high-pressure CO2 helps to control decay and increase firmness in strawberries. Increases in firmness occurred through modification of calcium binding to cell wall. However, the mechanism(s) involved in Ca(2+) migration to pectic polymers and other physiological events associated with the maintenance of increased firmness are not clearly understood. The focus of this study was to find potential mechanism(s) that are associated with calcium movement, increases in firmness, or maintenance of firmness in strawberry fruit after high-pressure CO2 treatment. An increase in firmness was induced by high-pressure CO2 treatment, but not by high-pressure N2 treatment. This indicates that CO2 stimulates a change in firmness. The increase in firmness induced by high-pressure CO2 seems to involve calcium efflux. Using membrane Ca(2+) -dependent ATPase inhibitors sodium vanadate (250 μM) and erythrosin B (100 μM) delayed both the increase in firmness and calcium binding to wall polymers. Exogenous application of CaCl2 (10 mM) enhanced the firmness increase of fruit slices only when they were exposed to high-pressure CO2 . The activity of pectate lyase was downregulated by CO2 treatment, but β-galactosidase activity was not affected. The increase in strawberry firmness induced by high-pressure CO2 treatment primarily involves the efflux of calcium ions and their binding to wall polymers. These physiological changes are not induced by an anaerobic environment. The downregulation of wall-modifying enzymes, such as pectate lyase, appeared to contribute to the maintenance of firmness that was induced by high-pressure CO2 treatment. © 2014 Institute of Food Technologists®

  9. Millennial-scale changes in atmospheric CO2 levels linked to the Southern Ocean carbon isotope gradient and dust flux

    Science.gov (United States)

    Ziegler, Martin; Diz, Paula; Hall, Ian R.; Zahn, Rainer

    2013-06-01

    The rise in atmospheric CO2 concentrations observed at the end of glacial periods has, at least in part, been attributed to the upwelling of carbon-rich deep water in the Southern Ocean. The magnitude of outgassing of dissolved CO2, however, is influenced by the biological fixation of upwelled inorganic carbon and its transfer back to the deep sea as organic carbon. The efficiency of this biological pump is controlled by the extent of nutrient utilization, which can be stimulated by the delivery of iron by atmospheric dust particles. Changes in nutrient utilization should be reflected in the δ13C gradient between intermediate and deep waters. Here we use the δ13C values of intermediate- and bottom-dwelling foraminifera to reconstruct the carbon isotope gradient between thermocline and abyssal water in the subantarctic zone of the South Atlantic Ocean over the past 360,000 years. We find millennial-scale oscillations of the carbon isotope gradient that correspond to changes in dust flux and atmospheric CO2 concentrations as reported from Antarctic ice cores. We interpret this correlation as a relationship between the efficiency of the biological pump and fertilization by dust-borne iron. As the correlation is exponential, we suggest that the sensitivity of the biological pump to dust-borne iron fertilization may be increased when the background dust flux is low.

  10. Impacts of elevated CO2 on exogenous Bacillus thuringiensis toxins and transgene expression in transgenic rice under different levels of nitrogen.

    Science.gov (United States)

    Jiang, Shoulin; Lu, Yongqing; Dai, Yang; Qian, Lei; Muhammad, Adnan Bodlah; Li, Teng; Wan, Guijun; Parajulee, Megha N; Chen, Fajun

    2017-11-07

    Recent studies have highlighted great challenges of transgene silencing for transgenic plants facing climate change. In order to understand the impacts of elevated CO 2 on exogenous Bacillus thuringiensis (Bt) toxins and transgene expression in transgenic rice under different levels of N-fertilizer supply, we investigated the biomass, exogenous Bt toxins, Bt-transgene expression and methylation status in Bt rice exposed to two levels of CO 2 concentrations and nitrogen (N) supply (1/8, 1/4, 1/2, 1 and 2 N). It is elucidated that the increased levels of global atmospheric CO 2 concentration will trigger up-regulation of Bt toxin expression in transgenic rice, especially with appropriate increase of N fertilizer supply, while, to some extent, the exogenous Bt-transgene expression is reduced at sub-N levels (1/4 and 1/2N), even though the total protein of plant tissues is reduced and the plant growth is restricted. The unpredictable and stochastic occurrence of transgene silencing and epigenetic alternations remains unresolved for most transgenic plants. It is expected that N fertilization supply may promote the expression of transgenic Bt toxin in transgenic Bt rice, particularly under elevated CO 2 .

  11. Development of Advanced High Strength Steel for Improved Vehicle Safety, Fuel Efficiency and CO2 Emission

    Science.gov (United States)

    Kumar, Satendra; Singhai, Mrigandra; Desai, Rahul; Sam, Srimanta; Patra, Pradip Kumar

    2016-10-01

    Global warming and green house gas emissions are the major issues worldwide and their impacts are clearly visible as a record high temperatures, rising sea, and severe `flooding and droughts'. Motor vehicles considered as a major contributor on global warming due to its green house gas emissions. Hence, the automobile industries are under tremendous pressure from government and society to reduce green house gas emission to maximum possible extent. In present work, Dual Phase steel with boron as microalloying is manufactured using thermo-mechanical treatment during hot rolling. Dual phase steel with boron microalloying improved strength by near about 200 MPa than dual phase steel without boron. The boron added dual phase steel can be used for manufacturing stronger and a lighter vehicle which is expected to perform positively on green house gas emissions. The corrosion resistance behavior is also improved with boron addition which would further increase the life cycle of the vehicle even under corrosive atmosphere.

  12. Hierarchical Core/Shell NiCo2O4@NiCo2O4 Nanocactus Arrays with Dual-functionalities for High Performance Supercapacitors and Li-ion Batteries

    Science.gov (United States)

    Cheng, Jinbing; Lu, Yang; Qiu, Kangwen; Yan, Hailong; Xu, Jinyou; Han, Lei; Liu, Xianming; Luo, Jingshan; Kim, Jang-Kyo; Luo, Yongsong

    2015-07-01

    We report the synthesis of t