Effect of simulated coal-derived gas composition on H{sub 2}S poisoning behavior evaluated using a disaggregation scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, T.S.; Miao, H.; Chen, T.

2009-07-01

H{sub 2}S poisoning is an important issue for solid oxide fuel cells (SOFCs) operated with syngas. The effect of simulated coal-derived gas composition on H{sub 2}S poisoning behavior was evaluated using a disaggregation scheme where the influence of H{sub 2} content was determined separately using a typical anode-supported SOFC operated with a N2/H{sub 2} mixture gas, while the effect of other compositions (CO, CO{sub 2}, and H{sub 2}O) was investigated with simulated coal-derived gas having constant H{sub 2} and CO flow rates balanced by a H{sub 2}/N2 mixture gas (83% H{sub 2} and 17% N2). The results indicated that themore » extent of H{sub 2}S poisoning was not pertinent to H{sub 2} content when the cell was tested galvanostatically with a current density of 0.3 A/cm{sup 2} at 800{sup o}C using a N2/H{sub 2} mixture gas containing 10 ppm H{sub 2}S, and the H{sub 2}S poisoning impact can be completely removed by switching to sulfur-free gas. The CO, CO{sub 2}, and high water vapor content aggravated the H{sub 2}S poisoning effect, and the performance was almost irrecoverable when the cell was tested with a 35% H{sub 2}-46% CO-16% N2-3% H{sub 2}O mixture gas containing 12.5 ppm H{sub 2}S. However, the introduction of 10% CO{sub 2} and an increase in H{sub 2}O content from 3 to 10% in the mixture gas can promote the performance recoverability to a larger extent.« less

CO 2-scrubbing and methanation as purification system for PEFC

NASA Astrophysics Data System (ADS)

Ledjeff-Hey, K.; Roes, J.; Wolters, R.

Hydrogen is usually produced by steam reforming of natural gas in large-scale processes. The reformate consists of hydrogen, carbon dioxide, carbon monoxide, and residues of hydrocarbons. Since the anode catalyst of a polymer electrolyte membrane fuel cell (PEFC) is usually based on platinum, which is easily poisoned by carbon monoxide, the conditioned feed gas should contain less than 100 ppmv CO, and preferably, less than 10 ppmv. Depending on the design and operating conditions of the hydrogen production process, the CO content of a typical reformate gas, even after the CO shift reactor may be in the range of 0.2-1.0 vol.%; this is far higher than a PEFC can tolerate. A CO management system is required to lower the CO concentration to acceptable levels. In many cases, the CO purification system consists of a combination of physical or chemical processes to achieve the necessary reduction in CO content. A promising alternative for hydrogen purification is a combined process consisting of a carbon dioxide scrubber with subsequent methanation to reduce the carbon monoxide content to an acceptable level of less than 10 ppmv.

Effects of ambient and elevated CO2 on growth, chlorophyll fluorescence, photosynthetic pigments, antioxidants, and secondary metabolites of Catharanthus roseus (L.) G Don. grown under three different soil N levels.

PubMed

Singh, Aradhana; Agrawal, Madhoolika

2015-03-01

Catharanthus roseus L. plants were grown under ambient (375 ± 30 ppm) and elevated (560 ± 25 ppm) concentrations of atmospheric CO2 at different rates of N supply (without supplemental N, 0 kg N ha(-1); recommended N, 50 kg N ha(-1); and double recommended N, 100 kg N ha(-1)) in open top chambers under field condition. Elevated CO2 significantly increased photosynthetic pigments, photosynthetic efficiency, and organic carbon content in leaves at recommended (RN) and double recommended N (DRN), while significantly decreased total nitrogen content in without supplemental N (WSN). Activities of superoxide dismutase, catalase, and ascorbate peroxidase were declined, while glutathione reductase, peroxidase, and phenylalanine-ammonia lyase were stimulated under elevated CO2. However, the responses of the above enzymes were modified with different rates of N supply. Elevated CO2 significantly reduced superoxide production rate, hydrogen peroxide, and malondialdehyde contents in RN and DRN. Compared with ambient, total alkaloids content increased maximally at recommended level of N, while total phenolics in WSN under elevated CO2. Elevated CO2 stimulated growth of plants by increasing plant height and numbers of branches and leaves, and the magnitude of increment were maximum in DRN. The study suggests that elevated CO2 has positively affected plants by increasing growth and alkaloids production and reducing the level of oxidative stress. However, the positive effects of elevated CO2 were comparatively lesser in plants grown under limited N availability than in moderate and higher N availability. Furthermore, the excess N supply in DRN has stimulated the growth but not the alkaloids production under elevated CO2.

Electrocatalytic activity and operational stability of electrodeposited Pd-Co films towards ethanol oxidation in alkaline electrolytes

NASA Astrophysics Data System (ADS)

Tsui, Lok-kun; Zafferoni, Claudio; Lavacchi, Alessandro; Innocenti, Massimo; Vizza, Francesco; Zangari, Giovanni

2015-10-01

Direct alkaline ethanol fuel cells (DEFCs) are usually run with Pd anodic catalysts, but their performance can be improved by utilizing alloys of Pd and Co. The oxyphilic Co serves to supply ample -OH to the ethanol oxidation reaction, accelerating the rate limiting step at low overpotential under alkaline conditions. Pd-Co films with compositions between 20 and 80 at% Co can be prepared by electrodeposition from a NH3 complexing electrolyte. Cyclic voltammetry studies show that the ethanol oxidation peak exhibits increasing current density with increasing Co content, reaching a maximum at 77% Co. In contrast, potentiostatic measurements under conditions closer to fuel cell operating conditions show that a 50 at% Co alloy has the highest performance. Importantly, the Co-Pd film is also found to undergo phase and morphological transformations during ethanol oxidation, resulting in a change from a compact film to high surface area flake-like structures containing Co3O4 and CoOOH; such a transformation instead is not observed when operating at a constant potential of 0.7 VRHE.

Monitoring the clean-up operation of agricultural fields flooded with red mud in Hungary.

PubMed

Uzinger, Nikolett; Rékási, Márk; Anton, Áron D; Koós, Sándor; László, Péter; Anton, Attila

2016-12-01

In the course of the clean-up operation after the red mud inundation in 2010, red mud was removed from the soil surface in places where the layer was more than 5 cm deep. Before its removal, the red mud seeped into the soil. In 2012, soil samples were taken from depths of 0 to 20 and 20 to 40 cm on some of the affected areas. The parameters investigated were pH, organic matter, salt%, and the total and mobile fractions of various elements. The values recorded in 2012 were compared with those measured immediately after the removal of the red mud in 2010 and with the background and clean-up target concentrations. The pH values remained below the designated limit, while the salt content only exhibited values in the weakly salty range on areas at the greatest distance from the dam. In the central part of the inundated area, total Na contents above the 900 mg/kg target value were observed, but the Na content in the 0-20-cm layer generally exhibited a decrease due to leaching. The pH and As concentration also showed a decline on several areas compared with the values recorded in 2010. Total As and Co contents in excess of the target values were recorded on the lowest-lying part of the flooded area, probably because the finest red mud particles were deposited the furthest from the dam, where they seeped into the soil. Nevertheless, the mobility and plant availability of both elements remained moderate. The total contents of both Co and Mo, however, exhibited a significant rise compared with both the background value and the 2010 data. The monitoring of the cleaned-up areas showed that after a 2-year period element concentrations that exceeded the target values and could be attributed to the red mud pollution were only detectable on the lowest-lying areas.

The Effect of Compression Ratio, Fuel Octane Rating, and Ethanol Content on Spark-Ignition Engine Efficiency.

PubMed

Leone, Thomas G; Anderson, James E; Davis, Richard S; Iqbal, Asim; Reese, Ronald A; Shelby, Michael H; Studzinski, William M

2015-09-15

Light-duty vehicles (LDVs) in the United States and elsewhere are required to meet increasingly challenging regulations on fuel economy and greenhouse gas (GHG) emissions as well as criteria pollutant emissions. New vehicle trends to improve efficiency include higher compression ratio, downsizing, turbocharging, downspeeding, and hybridization, each involving greater operation of spark-ignited (SI) engines under higher-load, knock-limited conditions. Higher octane ratings for regular-grade gasoline (with greater knock resistance) are an enabler for these technologies. This literature review discusses both fuel and engine factors affecting knock resistance and their contribution to higher engine efficiency and lower tailpipe CO2 emissions. Increasing compression ratios for future SI engines would be the primary response to a significant increase in fuel octane ratings. Existing LDVs would see more advanced spark timing and more efficient combustion phasing. Higher ethanol content is one available option for increasing the octane ratings of gasoline and would provide additional engine efficiency benefits for part and full load operation. An empirical calculation method is provided that allows estimation of expected vehicle efficiency, volumetric fuel economy, and CO2 emission benefits for future LDVs through higher compression ratios for different assumptions on fuel properties and engine types. Accurate "tank-to-wheel" estimates of this type are necessary for "well-to-wheel" analyses of increased gasoline octane ratings in the context of light duty vehicle transportation.

Demonstration of SCR technology for the control of NOx emissions from high-sulfur coal-fired utility boilers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hinton, W.S.; Maxwell, J.D.; Healy, E.C.

1997-12-31

This paper describes the completed Innovative Clean Coal Technology project which demonstrated SCR technology for reduction of flue gas NO{sub x} emissions from a utility boiler burning US high-sulfur coal. The project was sponsored by the US Department of Energy, managed and co-funded by Southern Company Services, Inc. on behalf of the Southern Company, and also co-funded by the Electric Power Research Institute and Ontario Hydro. The project was located at Gulf Power Company`s Plant Crist Unit 5 (a 75 MW tangentially-fired boiler burning US coals that had a sulfur content ranging from 2.5--2.9%), near Pensacola, Florida. The test programmore » was conducted for approximately two years to evaluate catalyst deactivation and other SCR operational effects. The SCR test facility had nine reactors: three 2.5 MW (5,000 scfm), and operated on low-dust flue gas. The reactors operated in parallel with commercially available SCR catalysts obtained from suppliers throughout the world. Long-term performance testing began in July 1993 and was completed in July 1995. A brief test facility description and the results of the project are presented in this paper.« less

Elevated CO2 induces substantial and persistent declines in forage digestibility and protein content irrespective of warming in mixed-grass prairie

USDA-ARS?s Scientific Manuscript database

Increasing atmospheric [CO2] and temperature are expected to affect the productivity, species composition, biogeochemistry, and therefore the quantity and quality of forage available to herbivores in rangeland ecosystems. Both elevated CO2 (eCO2) and warming affect plant tissue chemistry through mul...

EFFECTS OF BURN RATE, WOOD SPECIES, MOISTURE CONTENT AND WEIGHT OF WOOD LOADED ON WOODSTOVE EMISSIONS

EPA Science Inventory

The report gives results of tests of four woodstove operating parameters (burn rate, wood moisture, wood load, and wood species) at two levels each using a half factorial experimental test design to determine statistically significant effects on the emission components CO, CO2, p...

Electrode Edge Cobalt Cation Migration in an Operating Fuel Cell: An In Situ Micro-X-ray Fluorescence Study

DOE PAGES

Cai, Yun; Ziegelbauer, Joseph M.; Baker, Andrew M.; ...

2018-03-14

PtCo-alloy cathode electrocatalysts release Co cations under operation, and the presence of these cations in the membrane electrode assembly (MEA) can result in large performance losses. It is unlikely that these cations are static, but change positions depending on operating conditions. A thorough accounting of these Co cation positions and concentrations has been impossible to obtain owing to the inability to monitor these processes in operando. Indeed, the environment (water and ion content, potential, and temperature) within a fuel cell varies widely from inlet to outlet, from anode to cathode, and from active to inactive area. Here, synchrotron micro-X-ray fluorescencemore » (μ-XRF) was leveraged to directly monitor Co 2+ transport in an operating H 2/air MEA for the first time. A Nafion membrane was exchanged to a known Co cation capacity, and standard Pt/C electrocatalysts were utilized for both electrodes. Co Kα 1 XRF maps revealed through-plane transient Co transport responses driven by cell potential and current density. Because of the cell design and imaging geometry, the distributions were strongly impacted by the MEA edge configuration. These findings will drive future imaging cell designs to allow for quantitative mapping of cation through-plane distributions during operation.« less

Electrode Edge Cobalt Cation Migration in an Operating Fuel Cell: An In Situ Micro-X-ray Fluorescence Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Yun; Ziegelbauer, Joseph M.; Baker, Andrew M.

PtCo-alloy cathode electrocatalysts release Co cations under operation, and the presence of these cations in the membrane electrode assembly (MEA) can result in large performance losses. It is unlikely that these cations are static, but change positions depending on operating conditions. A thorough accounting of these Co cation positions and concentrations has been impossible to obtain owing to the inability to monitor these processes in operando. Indeed, the environment (water and ion content, potential, and temperature) within a fuel cell varies widely from inlet to outlet, from anode to cathode, and from active to inactive area. Here, synchrotron micro-X-ray fluorescencemore » (μ-XRF) was leveraged to directly monitor Co 2+ transport in an operating H 2/air MEA for the first time. A Nafion membrane was exchanged to a known Co cation capacity, and standard Pt/C electrocatalysts were utilized for both electrodes. Co Kα 1 XRF maps revealed through-plane transient Co transport responses driven by cell potential and current density. Because of the cell design and imaging geometry, the distributions were strongly impacted by the MEA edge configuration. These findings will drive future imaging cell designs to allow for quantitative mapping of cation through-plane distributions during operation.« less

The effect of CO2 availability on the growth, iron oxidation and CO2-fixation rates of pure cultures of Leptospirillum ferriphilum and Acidithiobacillus ferrooxidans.

PubMed

Bryan, C G; Davis-Belmar, C S; van Wyk, N; Fraser, M K; Dew, D; Rautenbach, G F; Harrison, S T L

2012-07-01

Understanding how bioleaching systems respond to the availability of CO(2) is essential to developing operating conditions that select for optimum microbial performance. Therefore, the effect of inlet gas and associated dissolved CO(2) concentration on the growth, iron oxidation and CO(2) -fixation rates of pure cultures of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum was investigated in a batch stirred tank system. The minimum inlet CO(2) concentrations required to promote the growth of At. ferrooxidans and L. ferriphilum were 25 and 70 ppm, respectively, and corresponded to dissolved CO(2) concentrations of 0.71 and 1.57 µM (at 30°C and 37°C, respectively). An actively growing culture of L. ferriphilum was able to maintain growth at inlet CO(2) concentrations less than 30 ppm (0.31-0.45 µM in solution). The highest total new cell production and maximum specific growth rates from the stationary phase inocula were observed with CO(2) inlet concentrations less than that of air. In contrast, the amount of CO(2) fixed per new cell produced increased with increasing inlet CO(2) concentrations above 100 ppm. Where inlet gas CO(2) concentrations were increased above that of air the additional CO(2) was consumed by the organisms but did not lead to increased cell production or significantly increase performance in terms of iron oxidation. It is proposed that At. ferrooxidans has two CO(2) uptake mechanisms, a high affinity system operating at low available CO(2) concentrations, which is subject to substrate inhibition and a low affinity system operating at higher available CO(2) concentrations. L. ferriphilum has a single uptake system characterised by a moderate CO(2) affinity. At. ferrooxidans performed better than L. ferriphilum at lower CO(2) availabilities, and was less affected by CO(2) starvation. Finally, the results demonstrate the limitations of using CO(2) uptake or ferrous iron oxidation data as indirect measures of cell growth and performance across varying physiological conditions. Copyright © 2012 Wiley Periodicals, Inc.

Optimization of supercritical carbon dioxide extraction of Piper Betel Linn leaves oil and total phenolic content

NASA Astrophysics Data System (ADS)

Aziz, A. H. A.; Yunus, M. A. C.; Arsad, N. H.; Lee, N. Y.; Idham, Z.; Razak, A. Q. A.

2016-11-01

Supercritical Carbon Dioxide (SC-CO2) Extraction was applied to extract piper betel linn leaves. The piper betel leaves oil was used antioxidant, anti-diabetic, anticancer and antistroke. The aim of this study was to optimize the conditions of pressure, temperature and flowrate for oil yield and total phenolic content. The operational conditions of SC-CO2 studied were pressure (10, 20, 30 MPa), temperature (40, 60, 80 °C) and flowrate carbon dioxide (4, 6, 8 mL/min). The constant parameters were average particle size and extraction regime, 355pm and 3.5 hours respectively. First order polynomial expression was used to express the extracted oil while second order polynomial expression was used to express the total phenolic content and the both results were satisfactory. The best conditions to maximize the total extraction oil yields and total phenolic content were 30 MPa, 80 °C and 4.42 mL/min leading to 7.32% of oil and 29.72 MPa, 67.53 °C and 7.98 mL/min leading to 845.085 mg GAE/g sample. In terms of optimum condition with high extraction yield and high total phenolic content in the extracts, the best operating conditions were 30 MPa, 78 °C and 8 mL/min with 7.05% yield and 791.709 mg gallic acid equivalent (GAE)/g sample. The most dominant condition for extraction of oil yield and phenolic content were pressure and CO2 flowrate. The results show a good fit to the proposed model and the optimal conditions obtained were within the experimental range with the value of R2 was 96.13% for percentage yield and 98.52% for total phenolic content.

Potentiel des méthodes de séparation et stockage du CO2 dans la lutte contre l'effet de serreThe role of CO2 capture and sequestration in mitigation of climate change

NASA Astrophysics Data System (ADS)

Jean-Baptiste, Philippe; Ducroux, René

2003-06-01

Increasing atmospheric level of greenhouse gases are causing global warming and putting at risk the global climate system. The main anthropogenic greenhouse gas is CO 2. Technical solutions exist to reduce CO 2 emission and stabilise atmospheric CO 2 concentration, including energy saving and energy efficiency, switch to lower carbon content fuels like natural gas and to energy sources that operate with zero CO 2 emissions such as renewable or nuclear energy, enhance the natural sinks for CO 2 (forests, soils, etc.), and last but not least, sequester CO 2 from fossil fuels combustion. The purpose of this paper is to provide an overview of the technology and cost for capture and storage of CO 2. Some of the factors that will influence application, including environmental impact, cost and efficiency, are also discussed. Capturing CO 2 and storing it in underground geological reservoirs appears as the best environmentally acceptable option. It can be done with existing technology; however, substantial R&D is needed to improve available technology and to lower the cost. Applicable to large CO 2 emitting industrial facilities such as power plants, cement factories, steel industry, etc., which amount to more than 30% of the global anthropogenic CO 2 emission, it represents a valuable tool in the battle against global warming. To cite this article: P. Jean-Baptiste, R. Ducroux, C. R. Geoscience 335 (2003).

Cardboard proportions and total solids contents as driving factors in dry co-fermentation of food waste.

PubMed

Capson-Tojo, Gabriel; Trably, Eric; Rouez, Maxime; Crest, Marion; Bernet, Nicolas; Steyer, Jean-Philippe; Delgenès, Jean-Philippe; Escudié, Renaud

2018-01-01

This study evaluated the influence of the co-substrate proportions (0-60% of cardboard in dry basis) and the initial total solid contents (20-40%) on the batch fermentation performance. Maximum hydrogen yields were obtained when mono-fermenting food waste at high solids contents (89mlH 2 ·gVS -1 ). The hydrogen yields were lower when increasing the proportions of cardboard. The lower hydrogen yields at higher proportions of cardboard were translated into higher yields of caproic acid (up to 70.1gCOD·kgCOD bio -1 ), produced by consumption of acetic acid and hydrogen. The highest substrate conversions were achieved at low proportions of cardboard, indicating a stabilization effect due to higher buffering capacities in co-fermentation. Clostridiales were predominant in all operational conditions. This study opens up new possibilities for using the cardboard proportions for controlling the production of high added-value products in dry co-fermentation of food waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impacts of elevated atmospheric CO2 on nutrient content of important food crops

NASA Astrophysics Data System (ADS)

Dietterich, Lee H.; Zanobetti, Antonella; Kloog, Itai; Huybers, Peter; Leakey, Andrew D. B.; Bloom, Arnold J.; Carlisle, Eli; Fernando, Nimesha; Fitzgerald, Glenn; Hasegawa, Toshihiro; Holbrook, N. Michele; Nelson, Randall L.; Norton, Robert; Ottman, Michael J.; Raboy, Victor; Sakai, Hidemitsu; Sartor, Karla A.; Schwartz, Joel; Seneweera, Saman; Usui, Yasuhiro; Yoshinaga, Satoshi; Myers, Samuel S.

2015-07-01

One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients.

Impacts of elevated atmospheric CO2 on nutrient content of important food crops

PubMed Central

Dietterich, Lee H.; Zanobetti, Antonella; Kloog, Itai; Huybers, Peter; Leakey, Andrew D. B.; Bloom, Arnold J.; Carlisle, Eli; Fernando, Nimesha; Fitzgerald, Glenn; Hasegawa, Toshihiro; Holbrook, N. Michele; Nelson, Randall L.; Norton, Robert; Ottman, Michael J.; Raboy, Victor; Sakai, Hidemitsu; Sartor, Karla A.; Schwartz, Joel; Seneweera, Saman; Usui, Yasuhiro; Yoshinaga, Satoshi; Myers, Samuel S.

2015-01-01

One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients. PMID:26217490

QCL seeded, ns-pulse, multi-line, CO2 laser oscillator for laser-produced-plasma extreme-UV source

NASA Astrophysics Data System (ADS)

Nowak, Krzysztof Michał; Suganuma, Takashi; Kurosawa, Yoshiaki; Ohta, Takeshi; Kawasuji, Yasufumi; Nakarai, Hiroaki; Saitou, Takashi; Fujimoto, Junichi; Mizoguchi, Hakaru; Sumitani, Akira; Endo, Akira

2017-01-01

Successful merger of state-of-the-art, semiconductor quantum-cascade lasers (QCL), with the mature CO2 laser technology, resulted in a delivery of highly-desired qualities of CO2 laser output that were not available previously without much effort. These qualities, such as multi-line operation, excellent spectro-temporal stability and pulse waveform control, became available from a single device of moderate complexity. This paper describes the operation principle and the unique properties of the solid{state seeded CO2 laser, invented for an application in laser-produced-plasma (LPP), extreme-UV (EUV) light source.

Non-slag co-gasification of biomass and coal in entrained-bed furnace

NASA Astrophysics Data System (ADS)

Itaya, Yoshinori; Suami, Akira; Kobayashi, Nobusuke

2018-02-01

Gasification is a promising candidate of processes to upgrade biomass and to yield clean gaseous fuel for utilization of renewable energy resources. However, a sufficient amount of biomass is not always available to operate a large scale of the plant. Co-gasification of biomass with coal is proposed as a solution of the problem. Tar emission is another subject during operation in shaft or kiln type of gasifiers employed conventionally for biomass. The present authors proposed co-gasification of biomass and coal in entrained-bed furnace, which is a representative process without tar emission under high temperature, but operated so to collect dust as flyash without molten slag formation. This paper presents the works performed on co-gasification performance of biomass and pulverized coal to apply to entrained-bed type of furnaces. At first, co-gasification of woody powder and pulverized coal examined using the lab-scale test furnace of the down-flow entrained bed showed that the maximum temperatures in the furnace was over 1500 K and the carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time in the furnace was as short as a few seconds. Non-slag co-gasification was carried out successfully without slag formation in the furnace if coal containing ash with high fusion temperature was employed. The trend suggesting the effect of reaction rate enhancement of co-gasification was also observed. Secondary, an innovative sewage sludge upgrading system consisting of self-energy recovery processes was proposed to yield bio-dried sludge and to sequentially produce char without adding auxiliary fuel. Carbonization behavior of bio-dried sludge was evaluated through pyrolysis examination in a lab-scale quartz tube reactor. The thermal treatment of pyrolysis of sludge contributed to decomposition and removal of contaminant components such as nitrogen and sulfur. The gasification kinetics of sludge and coal was also determined by a thermogravimetric analysis. It was revealed that co-gasification rate of sludge and coal chars was influenced negatively due to high ash content in sludge.

Assessing anaerobic co-digestion of pig manure with agroindustrial wastes: the link between environmental impacts and operational parameters.

PubMed

Rodriguez-Verde, Ivan; Regueiro, Leticia; Carballa, Marta; Hospido, Almudena; Lema, Juan M

2014-11-01

Anaerobic co-digestion (AcoD) is established as a techno-economic profitable process by incrementing biogas yield (increased cost-efficiency) and improving the nutrient balance (better quality digestate) in comparison to mono-digestion of livestock wastes. However, few data are available on the environmental consequences of AcoD and most of them are mainly related to the use of energy crops as co-substrates. This work analysed the environmental impact of the AcoD of pig manure (PM) with several agroindustrial wastes (molasses, fish, biodiesel and vinasses residues) using life cycle assessment (LCA) methodology. For comparative purposes, mono digestion of PM has also been evaluated. Four out of six selected categories (acidification, eutrophication, global warming and photochemical oxidation potentials) showed environmental impacts in all the scenarios assessed, whereas the other two (abiotic depletion and ozone layer depletion potentials) showed environmental credits, remarking the benefit of replacing fossil fuels by biogas. This was also confirmed by the sensitivity analysis applied to the PM quality (i.e. organic matter content) and the avoided energy source demonstrating the importance of the energy recovery step. The influence of the type of co-substrate could not be discerned; however, a link between the environmental performance and the hydraulic retention time, the organic loading rate and the nutrient content in the digestate could be established. Therefore, LCA results were successfully correlated to process variables involved in AcoD, going a step further in the combination of techno-economic and environmental feasibilities. Copyright © 2014 Elsevier B.V. All rights reserved.

LaRC-developed catalysts for CO2 lasers

NASA Technical Reports Server (NTRS)

Upchurch, Billy T.; Kielin, Erik J.; Miller, Irvin M.

1990-01-01

Pulsed CO2 lasers have many remote sensing applications from space, airborne, and ground platforms. The NASA Laser Atmospheric Wind Sounder (LAWS) system will be designed to measure wind velocities from polar earth orbit for a period of up to three years. Accordingly, this and other applications require a closed-cycle pulsed CO2 laser which necessitates the use of an efficient CO-O2 recombination catalyst for these dissociation products which otherwise would degrade the laser operation. The required catalyst must not only operate at low temperatures but also must operate efficiently for long time periods. The research effort at NASA LaRC has centered around development and testing of CO oxidation catalysts for closed-cycle, pulsed, common and rare-isotope CO2 lasers. Researchers examined available commercial catalysts both in a laser and under simulated closed-cycle laser conditions with efforts aimed toward a thorough understanding of the fundamental catalytic reaction. These data were used to design and synthesize new catalyst compositions to better meet the catalyst requirements for closed-cycle pulsed CO2 lasers. Syntheses and test results for catalysts developed at Langley Research Center which have significantly better long-term decay characteristics than previously available catalysts and at the same time operate quite well under lower temperature conditions are discussed.

Nitrogen losses and chemical parameters during co-composting of solid wastes and liquid pig manure.

PubMed

Vázquez, M A; de la Varga, D; Plana, R; Soto, M

2017-07-04

The aim of this research was to study nitrogen losses during the treatment of the liquid fraction (LF) of pig manure by co-composting and to establish the best conditions for compost production with higher nitrogen and low heavy metal contents. Windrows were constituted with the solid fraction (SF) of pig manure, different organic waste (SF of pig manure, sawdust and grape bagasse) as co-substrate and Populus spp. wood chips as bulking material and watered intensely with the LF. Results show that nitrogen losses ranged from 30% to 66% of initial nitrogen and were mainly governed by substrate to bulking mass ratio and liquid fraction to substrate (LF/S) ratio, and only secondarily by operational parameters. Nitrogen losses decreased from 55-65% at low LF/S ratios (1.7-1.9 m 3 /t total solids (TS)) to 30-39% at high LF/S ratios (4.4-4.7 m 3 /t TS). Therefore, integrating the LF in the composting process at high LF/S ratios favoured nitrogen recovery and conservation. Nitrogen in the fine fraction (ranging from 27% to 48% of initial nitrogen) was governed by operational parameters, namely pH and temperature. Final compost showed low content in most heavy metals, but Zn was higher than the limits for compost use in agriculture. Zn content in the obtained compost varied from 1863 to 3269 mg/kg dm, depending on several factors. The options for obtaining better quality composts from the LF of pig manure are selecting co-substrates with low heavy metal content and using them instead of the SF of pig manure.

The effect of silica particle sizes and promoters to equilibrium moisture content for CO2 hydrate formation in HPVA

NASA Astrophysics Data System (ADS)

Hassan, Mohd Hafiz Abu; Snape, Colin Edwards; Steven, Lee

2018-06-01

The formation of CO2 hydrate (CO2:6H2O) in this work was experimentally investigated in batch mode inside a high pressure volumetric analyser (HPVA). The investigations in pure CO2 gas systems highlighted the effect of type of silicas used and the concentration of promoters used on the amount of equilibrium moisture content available for formation of hydrate. Standard silica gel was the only silica found to show hydrate formation due to the best distribution of pore size with the amount of equilibrium moisture content of 14.8 wt%. The high amount of bulk water inside zeolites 13X and spherical MCF-17 (21.3 and 50.8 wt% respectively) was the main reason of no hydrate formation observed due to the interstitial spaces between both silica particles were fully occupied by water. In other words, diffusion of gas molecules into the water is required for hydrate nucleation as well as hydrate growth. Additionally, the combined-promoters designated type T1-5 (0.01 mol% sodium dodecyl sulphate (SDS)+5.6 mol% tetrahydrofuran (THF)) was the best obtaining a CO2 uptake of 5.95 mmol of CO2 per g of H2O with the amount of equilibrium moisture content of 13.28 wt%.

CO2 Absorption from Biogas by Glycerol: Conducted in Semi-Batch Bubble Column

NASA Astrophysics Data System (ADS)

puji lestari, Pratiwi; Mindaryani, Aswati; Wirawan, S. K.

2018-03-01

Biogas is a renewable energy source that has been developed recently. The main contents of Biogas itself are Methane and carbon dioxide (CO2) where Methane is the main component of biogas with CO2 as the highest impurities. The quality of biogas depends on the CO2 content, the lower CO2 levels, the higher biogas quality. Absorption is one of the methods to reduce CO2 level. The selections of absorbent and appropriate operating parameters are important factors in the CO2 absorption from biogas. This study aimed to find out the design parameters for CO2 absorption using glycerol that represented by the overall mass transfer coefficient (KLa) and Henry’s constant (H). This study was conducted in semi-batch bubble column. Mixed gas was contacted with glycerol in a bubble column. The concentration of CO2 in the feed gas inlet and outlet columns were analysed by Gas Chromatograph. The variables observed in this study were superficial gas velocity and temperatures. The results showed that higher superficial gas velocity and lower temperature increased the rate of absorption process and the amount of CO2 absorbed.

Impacts of elevated atmospheric CO₂ on nutrient content of important food crops.

PubMed

Dietterich, Lee H; Zanobetti, Antonella; Kloog, Itai; Huybers, Peter; Leakey, Andrew D B; Bloom, Arnold J; Carlisle, Eli; Fernando, Nimesha; Fitzgerald, Glenn; Hasegawa, Toshihiro; Holbrook, N Michele; Nelson, Randall L; Norton, Robert; Ottman, Michael J; Raboy, Victor; Sakai, Hidemitsu; Sartor, Karla A; Schwartz, Joel; Seneweera, Saman; Usui, Yasuhiro; Yoshinaga, Satoshi; Myers, Samuel S

2015-01-01

One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients.

[Co-composting high moisture vegetable waste and flower waste in a sequential fed operation].

PubMed

Zhang, Xiangfeng; Wang, Hongtao; Nie, Yongfeng

2003-11-01

Co-composting of high moisture vegetable wastes (celery and cabbage) and flower wastes (carnation) were studied in a sequential fed bed. The preliminary materials of composting were celery and carnation wastes. The sequential fed materials of composting were cabbage wastes and were fed every 4 days. Moisture content of mixture materials was between 60% and 70%. Composting was done in an aerobic static bed of composting based temperature feedback and control via aeration rate regulation. Aeration was ended when temperature of the pile was about 40 degrees C. Changes of composting of temperature, aeration rate, water content, organic matter, ash, pH, volume, NH4(+)-N, and NO3(-)-N were studied. Results show that co-composting of high moisture vegetable wastes and flower wastes, in a sequential fed aerobic static bed based temperature feedback and control via aeration rate regulation, can stabilize organic matter and removal water rapidly. The sequential fed operation are effective to overcome the difficult which traditional composting cannot applied successfully where high moisture vegetable wastes in more excess of flower wastes, such as Dianchi coastal.

Limitations to CO2-induced growth enhancement in pot studies.

PubMed

McConnaughay, K D M; Berntson, G M; Bazzaz, F A

1993-07-01

Recently, it has been suggested that small pots may reduce or eliminate plant responses to enriched CO 2 atmospheres due to root restriction. While smaller pot volumes provide less physical space available for root growth, they also provide less nutrients. Reduced nutrient availability alone may reduce growth enhancement under elevated CO 2 . To investigate the relative importance of limited physical rooting space separate from and in conjunction with soil nutrients, we grew plants at ambient and double-ambient CO 2 levels in growth containers of varied volume, shape, nutrient concentration, and total nutrient content. Two species (Abutilon theophrasti, a C 3 dicot with a deep tap root andSetaria faberii, a C 4 monocot with a shallow diffuse root system) were selected for their contrasting physiology and root architecture. Shoot demography was determined weekly and biomass was determined after eight and ten weeks of growth. Increasing total nutrients, either by increasing nutrient concentration or by increasing pot size, increased plant growth. Further, increasing pot size while maintaining equal total nutrients per pot resulted in increased total biomass for both species. CO 2 -induced growth and reproductive yield enhancements were greatest in pots with high nutrient concentrations, regardless of total nutrient content or pot size, and were also mediated by the shape of the pot. CO 2 -induced growth and reproductive yield enhancements were unaffected by pot size (growth) or were greater in small pots (reproductive yield), regardless of total nutrient content, contrary to predictions based on earlier studies. These results suggest that several aspects of growth conditions within pots may influence the CO 2 responses of plants; pot size, pot shape, the concentration and total amount of nutrient additions to pots may lead to over-or underestimates of the CO 2 responses of real-world plants.

Rational Design of a Hierarchical Tin Dendrite Electrode for Efficient Electrochemical Reduction of CO2.

PubMed

Won, Da Hye; Choi, Chang Hyuck; Chung, Jaehoon; Chung, Min Wook; Kim, Eun-Hee; Woo, Seong Ihl

2015-09-21

Catalysis is a key technology for the synthesis of renewable fuels through electrochemical reduction of CO2 . However, successful CO2 reduction still suffers from the lack of affordable catalyst design and understanding the factors governing catalysis. Herein, we demonstrate that the CO2 conversion selectivity on Sn (or SnOx /Sn) electrodes is correlated to the native oxygen content at the subsurface. Electrochemical analyses show that the reduced Sn electrode with abundant oxygen species effectively stabilizes a CO2 (.-) intermediate rather than the clean Sn surface, and consequently results in enhanced formate production in the CO2 reduction. Based on this design strategy, a hierarchical Sn dendrite electrode with high oxygen content, consisting of a multi-branched conifer-like structure with an enlarged surface area, was synthesized. The electrode exhibits a superior formate production rate (228.6 μmol h(-1)  cm(-2) ) at -1.36 VRHE without any considerable catalytic degradation over 18 h of operation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling of CO 2 sequestration in coal seams: Role of CO 2 -induced coal softening on injectivity, storage efficiency and caprock deformation: Original Research Article: Modeling of CO 2 sequestration in coal seams

DOE PAGES

Ma, Tianran; Rutqvist, Jonny; Liu, Weiqun; ...

2017-01-30

An effective and safe operation for sequestration of CO 2 in coal seams requires a clear understanding of injection-induced coupled hydromechanical processes such as the evolution of pore pressure, permeability, and induced caprock deformation. In this study, CO 2 injection into coal seams was studied using a coupled flow-deformation model with a new stress-dependent porosity and permeability model that considers CO 2 -induced coal softening. Based on triaxial compression tests of coal samples extracted from the site of the first series of enhanced coalbed methane field tests in China, a softening phenomenon that a substantial (one-order-of-magnitude) decrease of Young's modulusmore » and an increase of Poisson's ratio with adsorbed CO 2 content was observed. Such softening was considered in the numerical simulation through an exponential relation between elastic properties (Young's modulus and Poisson's ratio) and CO 2 pressure considering that CO 2 content is proportional to the CO 2 pressure. Our results of the numerical simulation show that the softening of the coal strongly affects the CO 2 sequestration performance, first by impeding injectivity and stored volume (cumulative injection) during the first week of injection, and thereafter by softening mediated rebound in permeability that tends to increase injectivity and storage over the longer term. A sensitivity study shows that stronger CO 2 -induced coal softening and higher CO 2 injection pressure contribute synergistically to increase a significant increase of CO 2 injectivity and adsorption, but also result in larger caprock deformations and uplift. This study demonstrates the importance of considering the CO 2 -induced softening when analyzing the performance and environmental impact of CO 2 -sequestration operations in unminable coal seams.« less

Modeling of CO 2 sequestration in coal seams: Role of CO 2 -induced coal softening on injectivity, storage efficiency and caprock deformation: Original Research Article: Modeling of CO 2 sequestration in coal seams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Tianran; Rutqvist, Jonny; Liu, Weiqun

An effective and safe operation for sequestration of CO 2 in coal seams requires a clear understanding of injection-induced coupled hydromechanical processes such as the evolution of pore pressure, permeability, and induced caprock deformation. In this study, CO 2 injection into coal seams was studied using a coupled flow-deformation model with a new stress-dependent porosity and permeability model that considers CO 2 -induced coal softening. Based on triaxial compression tests of coal samples extracted from the site of the first series of enhanced coalbed methane field tests in China, a softening phenomenon that a substantial (one-order-of-magnitude) decrease of Young's modulusmore » and an increase of Poisson's ratio with adsorbed CO 2 content was observed. Such softening was considered in the numerical simulation through an exponential relation between elastic properties (Young's modulus and Poisson's ratio) and CO 2 pressure considering that CO 2 content is proportional to the CO 2 pressure. Our results of the numerical simulation show that the softening of the coal strongly affects the CO 2 sequestration performance, first by impeding injectivity and stored volume (cumulative injection) during the first week of injection, and thereafter by softening mediated rebound in permeability that tends to increase injectivity and storage over the longer term. A sensitivity study shows that stronger CO 2 -induced coal softening and higher CO 2 injection pressure contribute synergistically to increase a significant increase of CO 2 injectivity and adsorption, but also result in larger caprock deformations and uplift. This study demonstrates the importance of considering the CO 2 -induced softening when analyzing the performance and environmental impact of CO 2 -sequestration operations in unminable coal seams.« less

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linville, Jessica L.; Shen, Yanwen; Ignacio-de Leon, Patricia A.

Here, a modified version of an in-situ CO 2 removal process was applied during AD of food waste with two types of walnut shell biochar (WSB) at bench-scale under batch operating mode. Compared to the coarse WSB, the fine WSB has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96 - 3.83 g biochar (g VS added) -1 fine WSB amended digestersmore » produced biogas with 77.5-98.1% CH 4 content by removing 40-96% of the CO 2 compared to the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added) -1, the fine WSB amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse WSB amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO3 from 2,800 mg L -1 in the control digesters to 4,800-6,800 mg L -1 providing process stability for food waste AD.« less

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale.

PubMed

Linville, Jessica L; Shen, Yanwen; Ignacio-de Leon, Patricia A; Schoene, Robin P; Urgun-Demirtas, Meltem

2017-06-01

A modified version of an in-situ CO 2 removal process was applied during anaerobic digestion of food waste with two types of walnut shell biochar at bench scale under batch operating mode. Compared with the coarse walnut shell biochar, the fine walnut shell biochar has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96-3.83 g biochar (g VS added ) -1 fine walnut shell biochar amended digesters produced biogas with 77.5%-98.1% CH 4 content by removing 40%-96% of the CO 2 compared with the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added ) -1 , the fine walnut shell biochar amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse walnut shell biochar amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO 3 from 2800 mg L -1 in the control digesters to 4800-6800 mg L -1 , providing process stability for food waste anaerobic digestion.

In-situ biogas upgrading during anaerobic digestion of food waste amended with walnut shell biochar at bench scale

DOE PAGES

Linville, Jessica L.; Shen, Yanwen; Ignacio-de Leon, Patricia A.; ...

2017-05-10

Here, a modified version of an in-situ CO 2 removal process was applied during AD of food waste with two types of walnut shell biochar (WSB) at bench-scale under batch operating mode. Compared to the coarse WSB, the fine WSB has a higher ash content (43 vs. 36 wt%) and higher concentrations of calcium (31 vs. 19 wt% of ash), magnesium (8.4 vs. 5.6 wt% of ash) and sodium (23.4 vs. 0.3 wt% of ash), but a lower potassium concentration (0.2 vs. 40% wt% of ash). The 0.96 - 3.83 g biochar (g VS added) -1 fine WSB amended digestersmore » produced biogas with 77.5-98.1% CH 4 content by removing 40-96% of the CO 2 compared to the control digesters at mesophilic and thermophilic temperature conditions. In a direct comparison at 1.83 g biochar (g VS added) -1, the fine WSB amended digesters (85.7% CH 4 content and 61% CO 2 removal) outperformed the coarse WSB amended digesters (78.9% CH 4 content and 51% CO 2 removal). Biochar addition also increased alkalinity as CaCO3 from 2,800 mg L -1 in the control digesters to 4,800-6,800 mg L -1 providing process stability for food waste AD.« less

Storytelling of co-operative team meetings in acute psychiatric care.

PubMed

Vuokila-Oikkonen, Päivi; Janhonen, Sirpa; Saarento, Outi; Harri, Marja

2002-10-01

One of the goals of co-operative psychiatric nursing and co-operative team meetings is to improve patients' and significant others' participation and thus, to enhance patients' resources outside the hospital. The objective of this paper is to describe the different expert interventions that either enabled or prevented patient and his/her significant others participation in co-operative team meetings in acute psychiatric wards. The data consisted of 11 videotaped team meetings. The participants were voluntary patients, significant others and experts in health and social care. A narrative approach focused on the storytelling of all members in the meetings. The method of modified dialogue analysis was used to identify the ideas of the stories. The same topic of discussion was shared in active participation. The experts asked open-ended questions, the patient and his/her significant others' were free to express their viewpoints and the experts' interpretation was based on their stories. The experts presented the reasons for their questions, and the contents of the questions were verbalized. In passive participation, the experts questions were based on their own point of view, and the patient and his significant others merely answered these questions. If the expert opinion appeared too dominating at the co-operative team meeting, the patient's and his/her significant others' participation was in jeopardy. The physician either dominates the storytelling or gives space for free expressions of various viewpoints during the co-operative team meetings.

Controls on soil organic matter content within a northern hardwood forest

Treesearch

K.D. Johnson; F.N. Scatena; A.H. Johnson; Y. Pan

2009-01-01

Forest soils can act as both sinks and sources for atmospheric CO2 and therefore have an important role in the global carbon cycle. Yet the controls on forest soil organic matter content (SOM) distribution at the scale of operational land management scales within forest types are rarely quantified in detail. To identify factors that influence the...

Carbon isotope variations in a solar pond microbial mat: Role of environmental gradients as steering variables

NASA Astrophysics Data System (ADS)

Schidlowski, Manfred; Gorzawski, Hendrik; Dor, Inka

1994-05-01

A biogeochemical traverse is presented for a juvenile benthic mat covering the depth profile of an artificially stratified and eutrophicated hypersaline heliothermal pond with known gradients of temperature, salinity, pH, and light transmission. It can be shown that visual mat development depends primarily on temperature and salinity as main environmental steering variables whose increase with depth goes along with the attenuation and final disappearance of a visible microbial film in the pond's hypolimnic compartment. Recorded biogeochemical parameters (C org content, cell numbers, chlorophyll-a content) evidently reflect, as either biomass- or productivity-related index functions, the visually perceptible growth gradient of the microbial ecosystem along the pond slope. The observed coincidence of maxima in these index functions with maxima in δ13Corg clearly identifies high rates of primary productivity as the agent ultimately responsible for the generation of isotopically heavy ( 13C-enriched) biomass in these and related environments. Extreme demands placed on the local feeder pool of dissolved inorganic carbon by high rates of primary productivity entertained by the mat-forming microbenthos obviously give rise to severe CO 2 limitation, enforcing the operation of a diffusion-(supply-)limited assimilatory pathway with an isotopically indiscriminate metabolization of the available CO 2 resources.

Recovering the Atmospheric Resources of Mars: Updating the MARRS Study

NASA Astrophysics Data System (ADS)

England, Christopher; Hrubes, J. Dana

2006-01-01

In 2000 a conceptual design was conducted of a plant that extracts oxygen (O2) directly from the martian atmosphere, and that makes water and carbon monoxide (CO) as by-products. Updated estimates suggest that the amount of O2 in the atmosphere is about 2.3 times greater than that used as the basis for the 2000 study. In this paper, estimates for O2 and by-products, and for energy and mass requirements based on the higher O2 value are updated. The basis for the design, termed ``MARRS'' for Mars Atmosphere Resource Recovery System, is the NASA/JSC Mars Reference Mission (MRM) requirement for O2, estimated at 5.8 kg/hr for about 500 sols. The 2000 study based its design on an atmospheric O2 content of 0.13%, the then-accepted value. Analysis now places the O2 content at about 0.3%, reducing the amount of energy and equipment proportionately. The revised estimate of the thermal power to meet MRM requirements for O2 is an average of about 52 kW, seasonally variable. The new mass estimate is 7898 kg, down from 13650 kg. The new estimate of oxygen content correspondingly reduces the amounts of by-products that can be recovered. CO, a primary fuel and propellant precursor, is produced at about 0.2 kg/kg O2. Water, possibly available at about 0.04 kg/kg O2, is believed not recoverable by the MARRS process at this lower level, even seasonally. An equation is provided for the seasonal variation in atmospheric O2 fraction based on Viking pressure measurements. Oxygen varies seasonally from about 0.25% or 0.34%, the variability affecting plant design. While the higher O2 fraction means reduced amounts of by-products from the MARRS process, large amounts of nitrogen (liquid and gas), argon gas and liquid carbon dioxide (CO2) remain available as by-products for use as respiratory agents, refrigerants, propellants, propellant precursors and working fluids for emergency or backup power, transportation, and surface operations such as drilling.

Adding worms during composting of organic waste with red mud and fly ash reduces CO2 emissions and increases plant available nutrient contents.

PubMed

Barthod, J; Rumpel, C; Calabi-Floody, M; Mora, M-L; Bolan, N S; Dignac, M-F

2018-09-15

Alkaline industrial wastes such as red mud and fly ash are produced in large quantities. They may be recycled as bulking agent during composting and vermicomposting, converting organic waste into soil amendments or plant growth media. The aim of this study was to assess the microbial parameters, greenhouse gas emissions and nutrient availability during composting and vermicomposting of household waste with red mud and fly ash 15% (dry weight). CO 2 , CH 4 and N 2 O emissions were monitored during 6 months in controlled laboratory conditions and microbial biomass and phospholipid acids, N and P availability were analysed in the end-products. Higher CO 2 emissions were observed during vermicomposting compared to composting. These emissions were decreased by red mud addition, while fly ash had no effect. Nitrate (NO 3 -N) content of the end-products were more affected by worms than by alkaline materials, while higher ammonium (NH 4 -N) contents were recorded for composts than vermicomposts. Red mud vermicompost showed higher soluble P proportion than red mud compost, suggesting that worm presence can counterbalance P adsorption to the inorganic matrix. Final composts produced with red mud showed no harmful heavy metal concentrations. Adding worms during composting thus improved the product nutrient availability and did not increase metal toxicity. From a practical point of view, this study suggests that for carbon stabilisation and end-product quality, the addition of red mud during composting should be accompanied by worm addition to counterbalance negative effects on nutrient availability. Copyright © 2018. Published by Elsevier Ltd.

Compost maturity and nitrogen availability by co-composting of paddy husk and chicken manure amended with clinoptilolite zeolite.

PubMed

Latifah, Omar; Ahmed, Osumanu Haruna; Susilawati, Kassim; Majid, Nik Muhamad

2015-04-01

The availability of paddy husk from rice processing plants remains high owing to increase in the worldwide rice consumption. Increasing demand for chicken products leads to poultry wastes production. Co-composting of the aforementioned wastes could solve the indiscriminate disposal of these wastes. Thus, co-composting of paddy husk and chicken slurry with clinoptilolite zeolite and urea as additive was carried out. Clinoptilolite zeolite was used to enhance ammonium and nitrate retention in the compost. Temperature of the compost was monitored three times daily for 55 days. Cation exchange capacity, organic matter, ash, humic acids, pH, total C, N, C/N ratio; total P, exchangeable Ca, Mg, K, NH4+, NO3-, and heavy metals contents were determined using standard procedures. pH, total N, humic acids, ash, NH4+, NO3-, P, Ca, Mg, and K contents increased but the salinity, heavy metals contents, and microbial population were low after the co-composting process. Zea mays L. (test crop) seed germination rate in distilled water and the compost were not significantly different. Growth of Spinach oleracea (test crop) on a peat-based growing medium and the compost was also not significantly different. These findings were possible because the clinoptilolite zeolite used in co-composting reduced accumulation of heavy metals that may have damage effects on the test crops. Mature compost with good agronomic properties can be produced by co-composting chicken slurry and paddy husk using clinoptilolite zeolite and urea as additives. © The Author(s) 2015.

Using a gradient in food quality to infer drivers of fatty acid content in two filter-feeding aquatic consumers

USGS Publications Warehouse

Larson, James H.; Richardson, William B.; Vallazza, Jon; Bartsch, Lynn; Bartsch, Michelle

2017-01-01

Inferences about ecological structure and function are often made using elemental or macromolecular tracers of food web structure. For example, inferences about food chain length are often made using stable isotope ratios of top predators and consumer food sources are often inferred from both stable isotopes and fatty acid (FA) content in consumer tissues. The use of FAs as tracers implies some degree of macromolecular conservation across trophic interactions, but many FAs are subject to physiological alteration and animals may produce those FAs from precursors in response to food deficiencies. We measured 41 individual FAs and several aggregate FA metrics in two filter-feeding taxa to (1) assess ecological variation in food availability and (2) identify potential drivers of among-site variation in FA content. These taxa were filter feeding caddisflies (Family Hydropyschidae) and dreissenid mussels (Genus Dreissena), which both consume seston. Stable isotopic composition (C and N) in these taxa co-varied across 13 sites in the Great Lakes region of North America, indicating they fed on very similar food resources. However, co-variation in FA content was very limited, with only one common FA co-varying across this gradient (α-linolenic acid; ALA), suggesting these taxa accumulate FAs very differently even when exposed to the same foods. Based on these results, among-site variation in ALA content in both consumers does appear to be driven by food resources, along with several other FAs in dreissenid mussels. We conclude that single-taxa measurements of FA content cannot be used to infer FA availability in food resources.

Hydrogen-Rich Gas Production by Cogasification of Coal and Biomass in an Intermittent Fluidized Bed

PubMed Central

Wang, Li-Qun; Chen, Zhao-Sheng

2013-01-01

This paper presents the experimental results of cogasification of coal and biomass in an intermittent fluidized bed reactor, aiming to investigate the influences of operation parameters such as gasification temperature (T), steam to biomass mass ratio (SBMR), and biomass to coal mass ratio (BCMR) on hydrogen-rich (H2-rich) gas production. The results show that H2-rich gas free of N2 dilution is produced and the H2 yield is in the range of 18.25~68.13 g/kg. The increases of T, SBMR, and BCMR are all favorable for promoting the H2 production. Higher temperature contributes to higher CO and H2 contents, as well as H2 yield. The BCMR has a weak influence on gas composition, but the yield and content of H2 increase with BCMR, reaching a peak at the BCMR of 4. The H2 content and yield in the product gas increase with SBMR, whilst the content of CO increases first and then decreases correspondingly. At a typical case, the relative linear sensitivity coefficients of H2 production efficiency to T, SBMR, and BCMR were calculated. The results reveal that the order of the influence of the operation parameters on H2 production efficiency is T > SBMR > BCMR. PMID:24174911

Effect-size measures as descriptors of assay quality in high-content screening: A brief review of some available methodologies

USDA-ARS?s Scientific Manuscript database

The field of high-content screening (HCS) typically uses measures of screen quality conceived for fairly straightforward high-throughput screening (HTS) scenarios. However, in contrast to HTS, image-based HCS systems rely on multidimensional readouts reporting biological responses associated with co...

Activity Descriptor Identification for Oxygen Reduction on Platinum-Based Bimetallic Nanoparticles: In Situ Observation of the Linear Composition–Strain–Activity Relationship

PubMed Central

2016-01-01

Despite recent progress in developing active and durable oxygen reduction catalysts with reduced Pt content, lack of elegant bottom-up synthesis procedures with knowledge over the control of atomic arrangement and morphology of the Pt–alloy catalysts still hinders fuel cell commercialization. To follow a less empirical synthesis path for improved Pt-based catalysts, it is essential to correlate catalytic performance to properties that can be easily controlled and measured experimentally. Herein, using Pt–Co alloy nanoparticles (NPs) with varying atomic composition as an example, we show that the atomic distribution of Pt-based bimetallic NPs under operating conditions is strongly dependent on the initial atomic ratio by employing microscopic and in situ spectroscopic techniques. The PtxCo/C NPs with high Co content possess a Co concentration gradient such that Co is concentrated in the core and gradually depletes in the near-surface region, whereas the PtxCo/C NPs with low Co content possess a relatively uniform distribution of Co with low Co population in the near-surface region. Despite their different atomic structure, the oxygen reduction reaction (ORR) activity of PtxCo/C and Pt/C NPs is linearly related to the bulk average Pt–Pt bond length (RPt–Pt). The RPt–Pt is further shown to contract linearly with the increase in Co/Pt composition. These linear correlations together demonstrate that (i) the improved ORR activity of PtxCo/C NPs over pure Pt NPs originates predominantly from the compressive strain and (ii) the RPt–Pt is a valid strain descriptor that bridges the activity and atomic composition of Pt-based bimetallic NPs. PMID:25559440

Activity descriptor identification for oxygen reduction on platinum-based bimetallic nanoparticles: in situ observation of the linear composition-strain-activity relationship.

PubMed

Jia, Qingying; Liang, Wentao; Bates, Michael K; Mani, Prasanna; Lee, Wendy; Mukerjee, Sanjeev

2015-01-27

Despite recent progress in developing active and durable oxygen reduction catalysts with reduced Pt content, lack of elegant bottom-up synthesis procedures with knowledge over the control of atomic arrangement and morphology of the Pt-alloy catalysts still hinders fuel cell commercialization. To follow a less empirical synthesis path for improved Pt-based catalysts, it is essential to correlate catalytic performance to properties that can be easily controlled and measured experimentally. Herein, using Pt-Co alloy nanoparticles (NPs) with varying atomic composition as an example, we show that the atomic distribution of Pt-based bimetallic NPs under operating conditions is strongly dependent on the initial atomic ratio by employing microscopic and in situ spectroscopic techniques. The PtxCo/C NPs with high Co content possess a Co concentration gradient such that Co is concentrated in the core and gradually depletes in the near-surface region, whereas the PtxCo/C NPs with low Co content possess a relatively uniform distribution of Co with low Co population in the near-surface region. Despite their different atomic structure, the oxygen reduction reaction (ORR) activity of PtxCo/C and Pt/C NPs is linearly related to the bulk average Pt-Pt bond length (RPt-Pt). The RPt-Pt is further shown to contract linearly with the increase in Co/Pt composition. These linear correlations together demonstrate that (i) the improved ORR activity of PtxCo/C NPs over pure Pt NPs originates predominantly from the compressive strain and (ii) the RPt-Pt is a valid strain descriptor that bridges the activity and atomic composition of Pt-based bimetallic NPs.

Scenarios of Use for Sociable Mobile TV

NASA Astrophysics Data System (ADS)

Chorianopoulos, Konstantinos

Mobile TVs have been available for many years, without ever becoming very popular. Moreover, the first wave of research has been mostly concerned with technology and standards, which are necessary to ensure interoperability and market acceptance. Although, there has been a significant body of computer-supported co-operative work (CSCW) and mobile human-computer interaction (HCI) research findings, there is limited investigation in the context of leisure activities, such as TV. In this article, we propose three concepts that drive the main paths for research and practice in mobile and social TV: (1) Mobile TV as a content format, (2) Mobile TV as user behavior, and (3) Mobile TV as interaction terminal. Finally, we provide particular directions to be considered in further research in social and mobile TV.

``Just Another Distribution Channel?''

NASA Astrophysics Data System (ADS)

Lemstra, Wolter; de Leeuw, Gerd-Jan; van de Kar, Els; Brand, Paul

The telecommunications-centric business model of mobile operators is under attack due to technological convergence in the communication and content industries. This has resulted in a plethora of academic contributions on the design of new business models and service platform architectures. However, a discussion of the challenges that operators are facing in adopting these models is lacking. We assess these challenges by considering the mobile network as part of the value system of the content industry. We will argue that from the perspective of a content provider the mobile network is ‘just another’ distribution channel. Strategic options available for the mobile communication operators are to deliver an excellent distribution channel for content delivery or to move upwards in the value chain by becoming a content aggregator. To become a mobile content aggregator operators will have to develop or acquire complementary resources and capabilities. Whether this strategic option is sustainable remains open.

Substrate quality and nutrient availability influence CO2 production from tropical peat decomposition

NASA Astrophysics Data System (ADS)

Swails, E.; Jaye, D.; Verchot, L. V.; Hergoualc'h, K.; Wahyuni, N. S.; Borchard, N.; Lawrence, D.

2015-12-01

In Indonesia, peatlands are a major and growing source of greenhouse gas emissions due to increasing pressure from oil palm and pulp wood plantations. We are using a combination of field measures, laboratory experiments, and remote sensing to investigate relationships among land use, climatic factors and biogeochemical controls, and their influence on trace gas fluxes from tropical peat soils. Analysis of soils collected from peat sites on two major islands indicated substantial variation in peat substrate quality and nutrient content among land uses and geographic location. We conducted laboratory incubations to test the influence of substrate quality and nutrient availability on CO2 production from peat decomposition. Differences in peat characteristics attributable to land use change were tested by comparison of forest and oil palm peat samples collected from the same peat dome in Kalimantan. Regional differences in peat characteristics were tested by comparison of samples from Sumatra with samples from Kalimantan. We conducted additional experiments to test the influence of N and P availability and labile carbon on CO2 production. Under moisture conditions typical of oil palm plantations, CO2 production was higher from peat forest samples than from oil palm samples. CO2 production from Sumatra and Kalimantan oil palm samples was not different, despite apparent differences in nutrient content of these soils. N and P treatments representative of fertilizer application rates raised CO2 production from forest samples but not oil palm samples. Labile carbon treatments raised CO2 production in all samples. Our results suggest that decomposition of peat forest soils is nutrient limited, while substrate quality controls decomposition of oil palm soils post-conversion. Though fertilizer application could accelerate peat decomposition initially, fertilizer application may not influence long-term CO2 emissions from oil palm on peat.

Matrix Transformation in Boron Containing High-Temperature Co-Re-Cr Alloys

NASA Astrophysics Data System (ADS)

Strunz, Pavel; Mukherji, Debashis; Beran, Přemysl; Gilles, Ralph; Karge, Lukas; Hofmann, Michael; Hoelzel, Markus; Rösler, Joachim; Farkas, Gergely

2018-03-01

An addition of boron largely increases the ductility in polycrystalline high-temperature Co-Re alloys. Therefore, the effect of boron on the alloy structural characteristics is of high importance for the stability of the matrix at operational temperatures. Volume fractions of ɛ (hexagonal close-packed—hcp), γ (face-centered cubic—fcc) and σ (Cr2Re3 type) phases were measured at ambient and high temperatures (up to 1500 °C) for a boron-containing Co-17Re-23Cr alloy using neutron diffraction. The matrix phase undergoes an allotropic transformation from ɛ to γ structure at high temperatures, similar to pure cobalt and to the previously investigated, more complex Co-17Re-23Cr-1.2Ta-2.6C alloy. It was determined in this study that the transformation temperature depends on the boron content (0-1000 wt. ppm). Nevertheless, the transformation temperature did not change monotonically with the increase in the boron content but reached a minimum at approximately 200 ppm of boron. A probable reason is the interplay between the amount of boron in the matrix and the amount of σ phase, which binds hcp-stabilizing elements (Cr and Re). Moreover, borides were identified in alloys with high boron content.

Model forecasting of phase composition of electrolytic alloys Co-Ni-Mn (part 1)

NASA Astrophysics Data System (ADS)

Schmidt, V. V.; Zhikhareva, I. G.

2018-03-01

With the help of four criteria for phase formation, a model forecasting of the phase composition of electrolytic alloy Co-Ni-Mn was carried out; the expected phases were calculated. The boundaries of the chemical content of the metal-solvent (Co) in these phases are determined, depending on the ratio of metal ions in the electrolyte of deposition. Model forecasting of the phase composition of Co-Ni-Mn alloys makes it possible to predict the type and number of Co phases (hexagonal close-packed - HCP-α-Co, face-centered cubic - FCC-β-Co) depending on the mole fraction of the solvent metal (Co). In the first approximation, the forecast allows one to determine the phase and chemical composition of the coating, which corresponds to the specified operational properties.

The Many Co-Operative Roles Available to Workshop Co-Facilitators

ERIC Educational Resources Information Center

Jacobs, George M.; Seow, Peter

2013-01-01

This paper argues that workshop co-facilitators should be actively involved in planning, conducting and debriefing the workshops in which they are involved. The paper discusses 12 possible roles for workshop co-facilitators and attempts to motivate some of these roles with reference to Humanistic Psychology, Social Interdependence Theory,…

An analytical study of nitrogen oxides and carbon monoxide emissions in hydrocarbon combustion with added nitrogen - Preliminary results

NASA Technical Reports Server (NTRS)

Bittker, D. A.

1980-01-01

The influence of ground-based gas turbine combustor operating conditions and fuel-bound nitrogen (FBN) found in coal-derived liquid fuels on the formation of nitrogen oxides and carbon monoxide is investigated. Analytical predictions of NOx and CO concentrations are obtained for a two-stage, adiabatic, perfectly-stirred reactor operating on a propane-air mixture, with primary equivalence ratios from 0.5 to 1.7, secondary equivalence ratios of 0.5 or 0.7, primary stage residence times from 12 to 20 msec, secondary stage residence times of 1, 2 and 3 msec and fuel nitrogen contents of 0.5, 1.0 and 2.0 wt %. Minimum nitrogen oxide but maximum carbon monoxide formation is obtained at primary zone equivalence ratios between 1.4 and 1.5, with percentage conversion of FBN to NOx decreasing with increased fuel nitrogen content. Additional secondary dilution is observed to reduce final pollutant concentrations, with NOx concentration independent of secondary residence time and CO decreasing with secondary residence time; primary zone residence time is not observed to affect final NOx and CO concentrations significantly. Finally, comparison of computed results with experimental values shows a good semiquantitative agreement.

Continuous high-solids anaerobic co-digestion of organic solid wastes under mesophilic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dong-Hoon; Oh, Sae-Eun, E-mail: saeun@hanbat.ac.kr

2011-09-15

Highlights: > High-solids (dry) anaerobic digestion is attracting a lot of attention these days. > One reactor was fed with food waste (FW) and paper waste. > Maximum biogas production rate of 5.0 m{sup 3}/m{sup 3}/d was achieved at HRT 40 d and 40% TS. > The other reactor was fed with FW and livestock waste (LW). > Until a 40% LW content increase, the reactor exhibited a stable performance. - Abstract: With increasing concerns over the limited capacity of landfills, conservation of resources, and reduction of CO{sub 2} emissions, high-solids (dry) anaerobic digestion of organic solid waste (OSW) ismore » attracting a great deal of attention these days. In the present work, two dry anaerobic co-digestion systems fed with different mixtures of OSW were continuously operated under mesophilic conditions. Dewatered sludge cake was used as a main seeding source. In reactor (I), which was fed with food waste (FW) and paper waste (PW), hydraulic retention time (HRT) and solid content were controlled to find the maximum treatability. At a fixed solid content of 30% total solids (TS), stable performance was maintained up to an HRT decrease to 40 d. However, the stable performance was not sustained at 30 d HRT, and hence, HRT was increased to 40 d again. In further operation, instead of decreasing HRT, solid content was increased to 40% TS, which was found to be a better option to increase the treatability. The biogas production rate (BPR), CH{sub 4} production yield (MPY) and VS reduction achieved in this condition were 5.0 m{sup 3}/m{sup 3}/d, 0.25 m{sup 3} CH{sub 4}/g COD{sub added}, and 80%, respectively. Reactor (II) was fed with FW and livestock waste (LW), and LW content was increased during the operation. Until a 40% LW content increase, reactor (II) exhibited a stable performance. A BPR of 1.7 m{sup 3}/m{sup 3}/d, MPY of 0.26 m{sup 3} CH{sub 4}/g COD{sub added}, and VS reduction of 72% was achieved at 40% LW content. However, when the LW content was increased to 60%, there was a significant performance drop, which was attributed to free ammonia inhibition. The performances in these two reactors were comparable to the ones achieved in the conventional wet digestion and thermophilic dry digestion processes.« less

Soil water content drives spatiotemporal patterns of CO2 and N2O emissions from a Mediterranean riparian forest soil

NASA Astrophysics Data System (ADS)

Poblador, Sílvia; Lupon, Anna; Sabaté, Santiago; Sabater, Francesc

2017-09-01

Riparian zones play a fundamental role in regulating the amount of carbon (C) and nitrogen (N) that is exported from catchments. However, C and N removal via soil gaseous pathways can influence local budgets of greenhouse gas (GHG) emissions and contribute to climate change. Over a year, we quantified soil effluxes of carbon dioxide (CO2) and nitrous oxide (N2O) from a Mediterranean riparian forest in order to understand the role of these ecosystems on catchment GHG emissions. In addition, we evaluated the main soil microbial processes that produce GHG (mineralization, nitrification, and denitrification) and how changes in soil properties can modify the GHG production over time and space. Riparian soils emitted larger amounts of CO2 (1.2-10 g C m-2 d-1) than N2O (0.001-0.2 mg N m-2 d-1) to the atmosphere attributed to high respiration and low denitrification rates. Both CO2 and N2O emissions showed a marked (but antagonistic) spatial gradient as a result of variations in soil water content across the riparian zone. Deep groundwater tables fueled large soil CO2 effluxes near the hillslope, while N2O emissions were higher in the wet zones adjacent to the stream channel. However, both CO2 and N2O emissions peaked after spring rewetting events, when optimal conditions of soil water content, temperature, and N availability favor microbial respiration, nitrification, and denitrification. Overall, our results highlight the role of water availability on riparian soil biogeochemistry and GHG emissions and suggest that climate change alterations in hydrologic regimes can affect the microbial processes that produce GHG as well as the contribution of these systems to regional and global biogeochemical cycles.

Towards a consistent mantle carbon flux estimate: Insights from volatile systematics (H 2O/Ce, δD, CO 2/Nb) in the North Atlantic mantle (14° N and 34° N)

NASA Astrophysics Data System (ADS)

Cartigny, Pierre; Pineau, Françoise; Aubaud, Cyril; Javoy, Marc

2008-01-01

In order to better characterise mantle CO 2/Nb-variability, we obtained and compiled major and trace elements, content and isotope composition of both CO 2 and water on two series of mid-ocean ridge basalt (MORB) samples dredged at ˜ 14° N ( n = 6) and 34° N ( n = 11) on the mid-Atlantic ridge. All samples are carbon-saturated. One, the so-called popping rock 2ΠD43 kept its vesicles, the initial (pre-degassing) C-contents of the 16 other samples being reconstructed from their assumed degassing history. For water, the samples show large variations, from 1300 to 6900 ppm and from 1900 to 7900 ppm with associated δD-values ranging from - 55 to - 79‰ and from - 55 to - 88‰ for samples at 14° N and 34° N respectively. For carbon, the inferred initial predegassing contents vary greatly, from 660 to 14,700 ppmCO 2 and from 1400 to 57,600 ppmCO 2 for samples at 14° N and 34° N respectively. Measured Nb-contents range from 4.5 to 29.6 ppm show both good agreement with previously published data and positive correlations with reconstructed initial CO 2-contents. The mean CO 2/Nb range from ˜ 570 to ˜ 730 at 14° N and 34° N respectively. CO 2 and Nb data for the two undegassed samples available so far (i.e. the popping rock of the present study and the basaltic glasses from the Siqueiros transform fault from the study of Saal et al., 2002) show significant variations in CO 2/Nb over a factor of 2 and thus questions the constant CO 2/Nb previously emphasised for these two samples, this view being supported by CO 2/Nb-ratios of samples whose initial C-contents were reconstructed. For incompatible elements such as Ce, K and including water, a comparison of the geochemical characteristics of transform fault basaltic magmatism with other MORB systems shows magma transform fault magmatism to be unrepresentative of mantle compositions. Assuming a more appropriate average MORB CO 2/Nb-ratio of ˜ 530 and a mean MORB Nb-content of 3.31-1.8+3.99, we computed a mantle carbon flux of 2.3-1.3+2.7 × 10 12 mol/yr, a value actually consistent with that derived from C/ 3He systematics.

Vitamin B5 and N-acetylcysteine in nonalcoholic steatohepatitis: a pre-clinical study in a dietary mouse model

PubMed Central

Machado, Mariana Verdelho; Kruger, Leandi; Jewell, Mark L.; Michelotti, Gregory Alexander; de Almeida Pereira, Thiago; Xie, Guanhua; Moylan, Cynthia A.; Diehl, Anna Mae

2015-01-01

Background Nonalcoholic fatty liver disease (NAFLD) is the number one cause of chronic liver disease and second indication for liver transplantation in the Western world. Effective therapy is still not available. Previously we showed a critical role for caspase-2 in the pathogenesis of nonalcoholic steatohepatitis (NASH), the potentially progressive form of NAFLD. An imbalance between free Coenzyme A (CoA) and acyl-CoA ratio is known to induce caspase-2 activation. Objectives We aimed to evaluate CoA metabolism and the effects of supplementation with CoA precursors, pantothenate and cysteine, in mouse models of NASH. Methods CoA metabolism was evaluated in methionine-choline deficient (MCD) and Western diet mouse models of NASH. MCD-diet fed mice were treated with pantothenate and N-acetylcysteine or placebo to determine effects on NASH. Results Liver free CoA content was reduced, pantothenate kinase (PANK), the rate-limiting enzyme in the CoA biosynthesis pathway, was down-regulated, and CoA degrading enzymes were increased in mice with NASH. Decreased hepatic free CoA content was associated with increased caspase-2 activity, and correlated with worse liver cell apoptosis, inflammation and fibrosis. Treatment with pantothenate and N-acetylcysteine did not inhibit caspase-2 activation, improve NASH, normalize PANK expression, or restore free CoA levels in MCD diet-fed mice. Conclusion In mice with NASH, hepatic CoA metabolism is impaired, leading to decreased free CoA content, activation of caspase-2, and increased liver cell apoptosis. Dietary supplementation with CoA precursors did not restore CoA levels or improve NASH, suggesting that alternative approaches are necessary to normalize free CoA during NASH. PMID:26403427

Citizen ’Cyber’ Airmen: Maintaining Ready and Proficient Cyberspace Operators in the Reserve Components

DTIC Science & Technology

2016-02-01

Internet service providers and global supply chains, over which DOD has no direct authority to mitigate risk effectively. The global technology supply...cyberspace. CO are composed of the military, intelligence, and ordinary business operations of DOD in and through cyberspace. Cyberspace, while a global ...infrastructures, including the Internet , telecommunications networks, computer systems, and embedded processors and controllers, and the content that flows across

Co-composting of green waste and food waste at low C/N ratio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Mathava; Ou, Y.-L.; Lin, J.-G., E-mail: jglin@mail.nctu.edu.t

2010-04-15

In this study, co-composting of food waste and green waste at low initial carbon to nitrogen (C/N) ratios was investigated using an in-vessel lab-scale composting reactor. The central composite design (CCD) and response surface method (RSM) were applied to obtain the optimal operating conditions over a range of preselected moisture contents (45-75%) and C/N ratios (13.9-19.6). The results indicate that the optimal moisture content for co-composting of food waste and green waste is 60%, and the substrate at a C/N ratio of 19.6 can be decomposed effectively to reduce 33% of total volatile solids (TVS) in 12 days. The TVSmore » reduction can be modeled by using a second-order equation with a good fit. In addition, the compost passes the standard germination index of white radish seed indicating that it can be used as soil amendment.« less

Natural desulfurization in coal-fired units using Greek lignite.

PubMed

Konidaris, Dimitrios N

2010-10-01

This paper analyzes the natural desulfurization process taking place in coal-fired units using Greek lignite. The dry scrubbing capability of Greek lignite appears to be extremely high under special conditions, which can make it possible for the units to operate within the legislative limits of sulfur dioxide (SO2) emissions. According to this study on several lignite-fired power stations in northern Greece, it was found that sulfur oxide emissions depend on coal rank, sulfur content, and calorific value. On the other hand, SO2 emission is inversely proportional to the parameter gammaCO2(max), which is equal to the maximum carbon dioxide (CO2) content by volume of dry flue gas under stoichiometric combustion. The desulfurization efficiency is positively correlated to the molar ratio of decomposed calcium carbonate to sulfur and negatively correlated to the free calcium oxide content of fly ash.

Leaf Area Index Drives Soil Water Availability and Extreme Drought-Related Mortality under Elevated CO2 in a Temperate Grassland Model System

PubMed Central

Manea, Anthony; Leishman, Michelle R.

2014-01-01

The magnitude and frequency of climatic extremes, such as drought, are predicted to increase under future climate change conditions. However, little is known about how other factors such as CO2 concentration will modify plant community responses to these extreme climatic events, even though such modifications are highly likely. We asked whether the response of grasslands to repeat extreme drought events is modified by elevated CO2, and if so, what are the underlying mechanisms? We grew grassland mesocosms consisting of 10 co-occurring grass species common to the Cumberland Plain Woodland of western Sydney under ambient and elevated CO2 and subjected them to repeated extreme drought treatments. The 10 species included a mix of C3, C4, native and exotic species. We hypothesized that a reduction in the stomatal conductance of the grasses under elevated CO2 would be offset by increases in the leaf area index thus the retention of soil water and the consequent vulnerability of the grasses to extreme drought would not differ between the CO2 treatments. Our results did not support this hypothesis: soil water content was significantly lower in the mesocosms grown under elevated CO2 and extreme drought-related mortality of the grasses was greater. The C4 and native grasses had significantly higher leaf area index under elevated CO2 levels. This offset the reduction in the stomatal conductance of the exotic grasses as well as increased rainfall interception, resulting in reduced soil water content in the elevated CO2 mesocosms. Our results suggest that projected increases in net primary productivity globally of grasslands in a high CO2 world may be limited by reduced soil water availability in the future. PMID:24632832

Leaf area index drives soil water availability and extreme drought-related mortality under elevated CO2 in a temperate grassland model system.

PubMed

Manea, Anthony; Leishman, Michelle R

2014-01-01

The magnitude and frequency of climatic extremes, such as drought, are predicted to increase under future climate change conditions. However, little is known about how other factors such as CO2 concentration will modify plant community responses to these extreme climatic events, even though such modifications are highly likely. We asked whether the response of grasslands to repeat extreme drought events is modified by elevated CO2, and if so, what are the underlying mechanisms? We grew grassland mesocosms consisting of 10 co-occurring grass species common to the Cumberland Plain Woodland of western Sydney under ambient and elevated CO2 and subjected them to repeated extreme drought treatments. The 10 species included a mix of C3, C4, native and exotic species. We hypothesized that a reduction in the stomatal conductance of the grasses under elevated CO2 would be offset by increases in the leaf area index thus the retention of soil water and the consequent vulnerability of the grasses to extreme drought would not differ between the CO2 treatments. Our results did not support this hypothesis: soil water content was significantly lower in the mesocosms grown under elevated CO2 and extreme drought-related mortality of the grasses was greater. The C4 and native grasses had significantly higher leaf area index under elevated CO2 levels. This offset the reduction in the stomatal conductance of the exotic grasses as well as increased rainfall interception, resulting in reduced soil water content in the elevated CO2 mesocosms. Our results suggest that projected increases in net primary productivity globally of grasslands in a high CO2 world may be limited by reduced soil water availability in the future.

Back to basics: informing the public of co-morbid physical health problems in those with mental illness.

PubMed

Ahire, Mrinalini; Sheridan, Judith; Regbetz, Shane; Stacey, Phillip; Scott, James G

2013-02-01

Those with mental illness are at increased risk of physical health problems. The current study aimed to examine the information available online to the Australian public about the increased risk and consequences of physical illness in those with mental health problems and the services available to address these co-morbidities. A structured online search was conducted with the search engine Google Australia (www.google.com.au) using generic search terms 'mental health information Australia', 'mental illness information Australia', 'depression', 'anxiety', and 'psychosis'. The direct content of websites was examined for information on the physical co-morbidities of mental illness. All external links on high-profile websites [the first five websites retrieved under each search term (n = 25)] were examined for information pertaining to physical health. Only 4.2% of websites informing the public about mental health contained direct content information about the increased risk of physical co-morbidities. The Australian Government's Department of Health and Ageing site did not contain any information. Of the high-profile websites, 62% had external links to resources about physical health and 55% had recommendations or resources for physical health. Most recommendations were generic. Relative to the seriousness of this problem, there is a paucity of information available to the public about the increased physical health risks associated with mental illness. Improved public awareness is the starting point of addressing this health inequity.

Engineering, construction, and operations in space

NASA Technical Reports Server (NTRS)

Johnson, Stewart W. (Editor); Wetzel, John P. (Editor)

1990-01-01

The century-old Mond process for carbonyl extraction of metals from ore shows great promise as an efficient low energy scheme for producing high-purity Fe, Ni, Cr, Mn, and Co from lunar or asteroidal feedstocks. Scenarios for winning oxygen from the lunar regolith can be enhanced by carbonyl processing of the metallic alloy by-products of such operations. The native metal content of asteroidal regoliths is even more suitable to carbonyl processing. High-purity, corrosion resistant Fe and Ni can be extracted from asteroidial feedstocks along with a Co-rich residue containing 0.5 percent platinum-group metals. The resulting gaseous metal carbonyl can produce a variety of end products using efficient vapor forming techniques.

An Analysis of Singaporean versus Indonesian Textbooks Based on Trigonometry Content

ERIC Educational Resources Information Center

Yang, Der-Ching; Sianturi, Iwan Andi

2017-01-01

Organization for Economic Co-operation and Development (OECD) (2016) released the results of Programme for International Student Assessment (PISA) 2015 and reported that the students' performance in mathematics of Singapore and Indonesia had significant differences. There is a strong relationship between textbooks used and mathematics performance…

Homepage to distribute the anatomy learning contents including Visible Korean products, comics, and books.

PubMed

Chung, Beom Sun; Chung, Min Suk

2018-03-01

The authors have operated the homepage (http://anatomy.co.kr) to provide the learning contents of anatomy. From the homepage, sectioned images, volume models, and surface models-all Visible Korean products-can be downloaded. The realistic images can be interactively manipulated, which will give rise to the interest in anatomy. The various anatomy comics (learning comics, comic strips, plastination comics, etc.) are approachable. Visitors can obtain the regional anatomy book with concise contents, mnemonics, and schematics as well as the simplified dissection manual and the pleasant anatomy essay. Medical students, health allied professional students, and even laypeople are expected to utilize the easy and comforting anatomy contents. It is hoped that other anatomists successively produce and distribute their own informative contents.

Vegetative biomass predicts inflorescence production along a CO2 concentration gradient in mesic grassland

NASA Astrophysics Data System (ADS)

Fay, P. A.; Collins, H.; Polley, W.

2016-12-01

Atmospheric CO2 concentration will likely exceed 500 µL L-1 by 2050, often increasing plant community productivity in part by increasing abundance of species favored by increased CA . Whether increased abundance translates to increased inflorescence production is poorly understood, and is important because it indicates the potential effects of CO2 enrichment on genetic variability and the potential for evolutionary change in future generations. We examined whether the responses of inflorescence production to CO2 enrichment in four C4 grasses and a C3 forb were predicted their vegetative biomass, and by soil moisture, soil nitrogen, or light availability. Inflorescence production was studied in a long-term CO2 concentration gradient spanning pre-industrial to anticipated mid-21st century values (250 - 500 µL L-1) maintained on clay, silty clay and sandy loam soils common in the U.S. Southern Plains. We expected that CO2 enrichment would increase inflorescence production, and more so with higher water, nitrogen, or light availability. However, structural equation modeling revealed that vegetative biomass was the single consistent direct predictor of flowering for all species (p < 0.001). Vegetative biomass increased, decreased, or did not respond to CO2 enrichment depending on the species. For the increasing species Sorghastrum nutans (C4 grass) and Solidago canadensis (C3 forb), direct CO2 effects on flowering were only weakly mediated by indirect effects of soil water content and soil NO3-N availability. For the decreasing species (Bouteloua curtipendula, C4 grass), the negative CO2-flowering relationship was cancelled (p = 0.39) by indirect effects of increased SWC and NO3-N on clay and silty clay soils. For the species with no CO2 response, inflorescence production was predicted only by direct water content (p < 0.0001, Schizachyrium scoparius, C4 grass) or vegetative biomass (p = 0.0009, Tridens albescens, C4 grass) effects. Light availability was unrelated to inflorescence production. Changes in inflorescence production are thus closely tied to direct and indirect effects of CO2 enrichment on vegetative biomass, and may either increase, decrease, or leave unchanged the potential for genetic variability and evolutionary change in future generations in response to global change drivers.

Identification of Preferential Paths of Fossil Carbon within Water Resource Recovery Facilities via Radiocarbon Analysis.

PubMed

Tseng, Linda Y; Robinson, Alice K; Zhang, Xiaying; Xu, Xiaomei; Southon, John; Hamilton, Andrew J; Sobhani, Reza; Stenstrom, Michael K; Rosso, Diego

2016-11-15

The Intergovernmental Panel on Climate Change (IPCC) reported that all carbon dioxide (CO 2 ) emissions generated by water resource recovery facilities (WRRFs) during treatment are modern, based on available literature. Therefore, such emissions were omitted from IPCC's greenhouse gas (GHG) accounting procedures. However, a fraction of wastewater's carbon is fossil in origin. We hypothesized that since the fossil carbon entering municipal WRRFs is mostly from soaps and detergents as dissolved organic matter, its fate can be selectively determined during the universally applied separation treatment processes. Analyzing radiocarbon at different treatment points within municipal WRRFs, we verified that the fossil content could amount to 28% in primary influent and showed varying distribution leaving different unit operations. We recorded the highest proportion of fossil carbon leaving the secondary treatment as off-gas and as solid sludge (averaged 2.08 kg fossil-CO 2 -emission-potential m -3 wastewater treated). By including fossil CO 2 , total GHG emission in municipal WRRFs increased 13%, and 23% if an on-site energy recovery system exists although much of the postdigestion fossil carbon remained in biosolids rather than in biogas, offering yet another carbon sequestration opportunity during biosolids handling. In comparison, fossil carbon contribution to GHG emission can span from negligible to substantial in different types of industrial WRRFs. With such a considerable impact, CO 2 should be analyzed for each WRRF and not omitted from GHG accounting.

Controlled environments alter nutrient content of soybeans

NASA Astrophysics Data System (ADS)

Jurgonski, L. J.; Smart, D. J.; Bugbee, B.; Nielsen, S. S.

1997-01-01

Information about compositional changes in plants grown in controlled environments is essential for developing a safe, nutritious diet for a Controlled Ecological Life-Support System (CELSS). Information now is available for some CELSS candidate crops, but detailed information has been lacking for soybeans. To determine the effect of environment on macronutrient and mineral composition of soybeans, plants were grown both in the field and in a controlled environment where the hydroponic nutrient solution, photosynthetic flux (PPF), and CO_2 level were manipulated to achieve rapid growth rates. Plants were harvested at seed maturity, separated into discrete parts, and oven dried prior to chemical analysis. Plant material was analyzed for proximate composition (moisture, protein, lipid, ash, and carbohydrate), total nitrogen (N), nonprotein N (NPN), nitrate, minerals, amino acid composition, and total dietary fiber. The effect of environment on composition varied by cultivar and plant part. Chamber-grown plants generally exhibited the following characteristics compared with field-grown plants: 1) increased total N and protein N for all plant parts, 2) increased nitrate in leaves and stems but not in seeds, 3) increased lipids in seeds, and 4) decreased Ca:P ratio for stems, pods, and leaves. These trends are consistent with data for other CELSS crops. Total N, protein N, and amino acid contents for 350 ppm CO_2 and 1000 ppm CO_2 were similar for seeds, but protein N and amino acid contents for leaves were higher at 350 ppm CO_2 than at 1000 ppm CO_2. Total dietary fiber content of soybean leaves was higher with 350 ppm CO_2 than with 1000 ppm CO_2. Such data will help in selecting of crop species, cultivars, and growing conditions to ensure safe, nutritious diets for CELSS.

Co-composting of Beef Cattle Feedlot Manure with Construction and Demolition Waste.

PubMed

Hao, Xiying; Hill, Brett; Caffyn, Pam; Travis, Greg; Olson, Andrew F; Larney, Francis J; McAllister, Tim; Alexander, Trevor

2014-09-01

With increased availability of dried distillers' grains with solubles (DDGS) as cattle feed and the need to recycle organic wastes, this research investigated the feasibility of co-composting DDGS cattle feedlot manure with construction and demolition (C&D) waste. Manure was collected from cattle fed a typical western Canadian finishing diet (CK) of 860 g rolled barley ( L.) grain, 100 g barley silage, and 40 g vitamin and mineral supplement kg dry matter (DM) and from cattle fed the same diet but (DG manure) with 300 g kg DM barley grain being replaced by DDGS. The CK and DG manures were co-composted with and without C&D waste in 13 m bins. Compost materials were turned on Days 14, 37, and 64, and terminated on Day 99. Adding C&D waste led to higher compost temperatures (0.4 to 16.3°C, average 7.2°C) than manure alone. Final composts had similar total C, total N, C/N ratios, and water-extractable K, Mg, and NO content across all treatments. However, adding C&D waste increased δC, δN, water-extractable SO, and Ca contents and decreased pH, total P (TP), water-extractable C, N, and P and most volatile fatty acids (VFA). The higher C&D compost temperatures should reduce pathogens while reduced VFA content should reduce odors. When using the final compost product, the increased SO and reduced TP and available N and P content in C&D waste compost should be taken into consideration. Increased S content in C&D compost may be beneficial for some crops grown on S-deficient soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Nutrient availability and nutrient use efficiency in plants growing in the transition zone between land and water.

PubMed

Cavalli, G; Baattrup-Pedersen, A; Riis, T

2016-03-01

The transition zone between terrestrial and freshwater habitats is highly dynamic, with large variability in environmental characteristics. Here, we investigate how these characteristics influence the nutritional status and performance of plant life forms inhabiting this zone. Specifically, we hypothesised that: (i) tissue nutrient content differs among submerged, amphibious and terrestrial species, with higher content in submerged species; and (ii) PNUE gradually increases from submerged over amphibious to terrestrial species, reflecting differences in the availability of N and P relative to inorganic C across the land-water ecotone. We found that tissue nutrient content was generally higher in submerged species and C:N and C:P ratios indicated that content was limiting for growth for ca. 20% of plant individuals, particularly those belonging to amphibious and terrestrial species groups. As predicted, the PNUE increased from submerged over amphibious to terrestrial species. We suggest that this pattern reflects that amphibious and terrestrial species allocate proportionally more nutrients into processes of importance for photosynthesis at saturating CO2 availability, i.e. enzymes involved in substrate regeneration, compared to submerged species that are acclimated to lower availability of CO2 in the aquatic environment. Our results indicate that enhanced nutrient loading may affect relative abundance of the three species groups in the land-water ecotone of stream ecosystems. Thus, species of amphibious and terrestrial species groups are likely to benefit more from enhanced nutrient availability in terms of faster growth compared to aquatic species, and that this can be detrimental to aquatic species growing in the land-water ecotone, e.g. Ranunculus and Callitriche. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

On providing the fault-tolerant operation of information systems based on open content management systems

NASA Astrophysics Data System (ADS)

Kratov, Sergey

2018-01-01

Modern information systems designed to service a wide range of users, regardless of their subject area, are increasingly based on Web technologies and are available to users via Internet. The article discusses the issues of providing the fault-tolerant operation of such information systems, based on free and open source content management systems. The toolkit available to administrators of similar systems is shown; the scenarios for using these tools are described. Options for organizing backups and restoring the operability of systems after failures are suggested. Application of the proposed methods and approaches allows providing continuous monitoring of the state of systems, timely response to the emergence of possible problems and their prompt solution.

Development under elevated pCO2 conditions does not affect lipid utilization and protein content in early life-history stages of the purple sea urchin, Strongylocentrotus purpuratus.

PubMed

Matson, Paul G; Yu, Pauline C; Sewell, Mary A; Hofmann, Gretchen E

2012-12-01

Ocean acidification (OA) is expected to have a major impact on marine species, particularly during early life-history stages. These effects appear to be species-specific and may include reduced survival, altered morphology, and depressed metabolism. However, less information is available regarding the bioenergetics of development under elevated CO(2) conditions. We examined the biochemical and morphological responses of Strongylocentrotus purpuratus during early development under ecologically relevant levels of pCO(2) (365, 1030, and 1450 μatm) that may occur during intense upwelling events. The principal findings of this study were (1) lipid utilization rates and protein content in S. purpuratus did not vary with pCO(2); (2) larval growth was reduced at elevated pCO(2) despite similar rates of energy utilization; and (3) relationships between egg phospholipid content and larval length were found under control but not high pCO(2) conditions. These results suggest that this species may either prioritize endogenous energy toward development and physiological function at the expense of growth, or that reduced larval length may be strictly due to higher costs of growth under OA conditions. This study highlights the need to further expand our knowledge of the physiological mechanisms involved in OA response in order to better understand how present populations may respond to global environmental change.

CO2-induced photosynthetic and stoichiometric responses to phosphorus limitation

NASA Astrophysics Data System (ADS)

de Boer, Hugo; di Lallo, Giacomo; van Dijk, Jerry

2017-04-01

Carbon fertilisation from rising atmospheric CO2 concentrations increases the productivity of plants globally. Meanwhile, the global cycles of Nitrogen (N) and Phosphorus (P) are also altered due to anthropogenic emissions. In general, the additional supply of N is expected to exceed that of P, leading to an increase in P limitation in natural ecosystems. Although the direct carbon fertilisation effect and the interaction with available N is relatively well understood, it remains uncertain how carbon fertilisation is confounded by the availability of P. It is hypothesised that (i) the photosynthetic P-use efficiency increases at elevated CO2 owing to a direct increase in photosynthesis and (ii) the photosynthetic maximum carboxylation rate (Vcmax) and electron transport rate (Jmax) are down-regulated in response to a combination of elevated CO2 and P-limitation via a coordinated reduction of leaf N and P content per unit leaf area. In this study we examined the hypothesised effects of P limitation and CO2 fertilisation on the photosynthetic and stoichiometric responses of three plant species: Holcus lanatus (C3 grass), Panicum miliaceum (C4 grass) and Solanum dulcamara (C3 herb). Individuals of these species were grown at sub-ambient (150 ppm), modern (450 ppm) and elevated CO2 concentrations (800 ppm) and exposed to an N:P treatment consisting of either severe nitrogen limitation at an N:P ratio of 1:1, or severe P limitation at an N:P ratio of 45:1, with a similar supply rate of N. Our results show significant effects of growth CO2 and P supply on Vcmax and Jmax, as well as the whole-plant biomass at the point of harvest. Interaction effects between growth CO2 and P supply were observed for the light-saturated photosynthesis rate, stomatal conductance, leaf P content, and the N:P ratio of the leaf. No significant change in the leaf N content was observed across treatments. These results suggest that limited availability of P constrains the biochemical potential for plants to up-regulate Vcmax and Jmax. This effect is most prominently expressed at low CO2 growth conditions, which induce strong up-regulation of Vcmax and Jmax when P is not limiting. Conversely, the down-regulation of Vcmax and Jmax at elevated CO2 is more pronounced when P is limiting. Hence, the combined effects of rising CO2 and additional P limitation may result in additional down-regulation of Vcmax and Jmax and a subsequent waning of the CO2 fertilisation effect. These results highlight the need to consider P limitation in global vegetation models when studying carbon fertilisation effects.

Understorey productivity in temperate grassy woodland responds to soil water availability but not to elevated [CO2 ].

PubMed

Collins, Luke; Bradstock, Ross A; Resco de Dios, Victor; Duursma, Remko A; Velasco, Sabrina; Boer, Matthias M

2018-06-01

Rising atmospheric [CO 2 ] and associated climate change are expected to modify primary productivity across a range of ecosystems globally. Increasing aridity is predicted to reduce grassland productivity, although rising [CO 2 ] and associated increases in plant water use efficiency may partially offset the effect of drying on growth. Difficulties arise in predicting the direction and magnitude of future changes in ecosystem productivity, due to limited field experimentation investigating climate and CO 2 interactions. We use repeat near-surface digital photography to quantify the effects of water availability and experimentally manipulated elevated [CO 2 ] (eCO 2 ) on understorey live foliage cover and biomass over three growing seasons in a temperate grassy woodland in south-eastern Australia. We hypothesised that (i) understorey herbaceous productivity is dependent upon soil water availability, and (ii) that eCO 2 will increase productivity, with greatest stimulation occurring under conditions of low water availability. Soil volumetric water content (VWC) determined foliage cover and growth rates over the length of the growing season (August to March), with low VWC (<0.1 m 3  m -3 ) reducing productivity. However, eCO 2 did not increase herbaceous cover and biomass over the duration of the experiment, or mitigate the effects of low water availability on understorey growth rates and cover. Our findings suggest that projected increases in aridity in temperate woodlands are likely to lead to reduced understorey productivity, with little scope for eCO 2 to offset these changes. © 2018 John Wiley & Sons Ltd.

A Solid Earth educational module, co-operatively developed by scientists and high school teachers through the Scripps Classroom Connection GK12 Program

NASA Astrophysics Data System (ADS)

Ziegler, L. B.; van Dusen, D.; Benedict, R.; Chojnacki, P. R.; Peach, C. L.; Staudigel, H.; Constable, C.; Laske, G.

2010-12-01

The Scripps Classroom Connection, funded through the NSF GK-12 program, pairs local high school teachers with Scripps Institution of Oceanography (SIO) graduate students in the earth and ocean sciences for their mutual professional development. An integral goal of the program is the collaborative production of quality earth science educational modules that are tested in the classroom and subsequently made freely available online for use by other educators. We present a brief overview of the program structure in place to support this goal and illustrate a module that we have developed on the Solid Earth & Plate Tectonics for a 9th grade Earth Science classroom. The unit includes 1) an exercise in constructing a geomagnetic polarity timescale which exposes students to authentic scientific data; 2) activities, labs, lectures and worksheets that support the scientific content; and 3) use of online resources such as Google Earth and interactive animations that help students better understand the concepts. The educational unit is being implemented in two separate local area high schools for Fall 2010 and we will report on our experiences. The co-operative efforts of teachers and scientists lead to educational materials which expose students to the scientific process and current science research, while teaching basic concepts using an engaging inquiry-based approach. In turn, graduate students involved gain experience communicating their science to non-science audiences.

Sensor for oxygen-combustibles gas mixtures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isenberg, A.O.

1981-08-25

A molten carbonate electrochemical cell is described which operates at a temperature between 400/sup 0/ and 700/sup 0/ C. It used to remove O/sub 2/ in combination with CO/sub 2/ from an oxygen/combustibles gas mixture to provide a low temperature measurement of the oxygen content of the gas mixture.

Electromagnetic properties of Fe-Co granular composite materials containing acicular nanoparticles

NASA Astrophysics Data System (ADS)

Kasagi, Teruhiro; Massango, Herieta; Tsutaoka, Takanori; Yamamoto, Shinichiro; Hatakeyama, Kenichi

2018-03-01

Electromagnetic properties of acicular (needle-like) Fe76Co24 nanoparticle composite materials have been studied in microwave frequency range up to 20 GHz. The Fe76Co24 particles are commercially available acicular Fe76Co24 nanoparticles with an approximate length and diameter of 100 and 25 nm, respectively. The Fe76Co24 nanocomposites were prepared by embedding the Fe76Co24 nanoparticle in an appropriate resin. Since the metallic Fe76Co24 nanoparticles have an oxidized surface, even high particle content composites at 78 vol.%, which is in the percolated state, does not show metallic conduction; a low frequency plasmonic state with the negative permittivity spectrum was not observed. Meanwhile, the negative permeability spectrum caused by the magnetic resonance in Fe76Co24 alloy was obtained in the high particle content composites. From the measurement of the complex permeability spectra under the external dc magnetic field, it was clarified that the gyromagnetic spin rotation mainly contributes to the permeability spectrum of nanocomposites due to extremely small quantity of domain walls in the acicular nanoparticles. This result suggests that the negative permeability spectrum was caused by the gyromagnetic spin resonance. By the comparison of the complex permeability spectrum between the acicular Fe76Co24 nanocomposite and the spherical Fe50Co50 microcomposite, the gyromagnetic spin resonance frequency of the acicular nanocomposite tends to locate higher than that of the spherical microcomposite owing to the demagnetizing field effect. Therefore, it can be concluded that the negative permeability frequency band of the acicular nanocomposite is higher than that of the spherical microcomposite at the same particle content.

Homepage to distribute the anatomy learning contents including Visible Korean products, comics, and books

PubMed Central

Chung, Beom Sun

2018-01-01

The authors have operated the homepage (http://anatomy.co.kr) to provide the learning contents of anatomy. From the homepage, sectioned images, volume models, and surface models—all Visible Korean products—can be downloaded. The realistic images can be interactively manipulated, which will give rise to the interest in anatomy. The various anatomy comics (learning comics, comic strips, plastination comics, etc.) are approachable. Visitors can obtain the regional anatomy book with concise contents, mnemonics, and schematics as well as the simplified dissection manual and the pleasant anatomy essay. Medical students, health allied professional students, and even laypeople are expected to utilize the easy and comforting anatomy contents. It is hoped that other anatomists successively produce and distribute their own informative contents. PMID:29644104

Identification of locally available structural material as co-substrate for organic waste composting in Tamil Nadu, India.

PubMed

Springer, C; Heldt, N

2016-06-01

Owing to the lack in structural strength while composting certain kinds of organic wastes, 11 co-substrates were tested that are generally locally available in rural areas of northern Tamil Nadu, India. In addition to the classical composting parameters such as carbon/nitrogen ratio, moisture content, dry matter and organic dry matter, a compression test was conducted to evaluate the structural strength and the suitability as bulking agent for composting processes. Additionally, with respect to the climatic conditions in India, the water holding capacity was also evaluated. © The Author(s) 2016.

A novel technique to determine cobalt exchangeability in soils using isotope dilution.

PubMed

Wendling, Laura A; Kirby, Jason K; McLaughlin, Michael J

2008-01-01

The environmental risk posed by Co contamination is largely a function of its oxidation state. Our objective was to assess the potential biological availability of Co and the reactions and fate of soluble Co(II) after addition to soils with varying physical and chemical characteristics. A potential risk in quantifying exchangeable Co in soils using isotope dilution techniques is the possible presence of two species of Co in soil solution and adsorbed on soil solid phases [Co(II) and Co(III)], coupled with the possibility that when an isotope of Co is added it may undergo a change in oxidation state during the measurement phase. In this study, we have utilized an isotope dilution technique with cation exchange and high-performance liquid chromatography-inductively coupled plasma-mass spectrometry to determine the isotopically exchangeable Co fraction in several soils with varying characteristics such as differing Al, Fe, and Mn oxide content; pH; and organic carbon content. The application of the cation exchange procedure adjusts measurements of isotopically exchangeable Co to correct for the presence of non-exchangeable 57Co not in equilibrium with the solution phase. Results indicated that oxidation of added 57Co(II) to 57Co(III) or precipitation of 57Co(II) may occur on the surfaces of some soils, particularly those with a high pH or substantial quantities of Mn oxide minerals. No detectable Co(III)(aq) was found in the aqueous extracts of the soils examined.

How will climate change influence grapevine cv. Tempranillo photosynthesis under different soil textures?

PubMed

Leibar, Urtzi; Aizpurua, Ana; Unamunzaga, Olatz; Pascual, Inmaculada; Morales, Fermín

2015-05-01

While photosynthetic responses to elevated CO2, elevated temperature, or water availability have previously been reported for grapevine as responses to single stress factors, reports on the combined effect of multiple stress factors are scarce. In the present work, we evaluated effects of simulated climate change [CC; 700 ppm CO2, 28/18 °C, and 33/53% relative humidity (RH), day/night] versus current conditions (375 ppm CO2, 24/14 °C, and 45/65% RH), water availability (well-irrigated vs. water deficit), and different types of soil textures (41, 19, and 8% of soil clay contents) on grapevine (Vitis vinifera L. cv. Tempranillo) photosynthesis. Plants were grown using the fruit-bearing cutting model. CC increased the photosynthetic activity of grapevine plants grown under well-watered conditions, but such beneficial effects of elevated CO2, elevated temperature, and low RH were abolished by water deficit. Under water-deficit conditions, plants subjected to CC conditions had similar photosynthetic rates as those grown under current conditions, despite their higher sub-stomatal CO2 concentrations. As expected, water deficit reduced photosynthetic activity in association with inducing stomatal closure that prevents water loss. Evidence for photosynthetic downregulation under elevated CO2 was observed, with decreases in photosynthetic capacity and leaf N content and increases in the C/N ratio in plants subjected to CC conditions. Soil texture had no marked effects on photosynthesis and did not modify the photosynthetic response to CC and water-deficit conditions. However, in mature well-irrigated plants grown in the soils with the highest sand content, an important decrease in stomatal conductance was observed as well as a slight decrease in the utilization of absorbed light in photosynthetic electron transport (measured as photochemical quenching), possibly related to a low water-retention capacity of these soils even under well-watered conditions.

Harvesting Intelligence in Multimedia Social Tagging Systems

NASA Astrophysics Data System (ADS)

Giannakidou, Eirini; Kaklidou, Foteini; Chatzilari, Elisavet; Kompatsiaris, Ioannis; Vakali, Athena

As more people adopt tagging practices, social tagging systems tend to form rich knowledge repositories that enable the extraction of patterns reflecting the way content semantics is perceived by the web users. This is of particular importance, especially in the case of multimedia content, since the availability of such content in the web is very high and its efficient retrieval using textual annotations or content-based automatically extracted metadata still remains a challenge. It is argued that complementing multimedia analysis techniques with knowledge drawn from web social annotations may facilitate multimedia content management. This chapter focuses on analyzing tagging patterns and combining them with content feature extraction methods, generating, thus, intelligence from multimedia social tagging systems. Emphasis is placed on using all available "tracks" of knowledge, that is tag co-occurrence together with semantic relations among tags and low-level features of the content. Towards this direction, a survey on the theoretical background and the adopted practices for analysis of multimedia social content are presented. A case study from Flickr illustrates the efficiency of the proposed approach.

Role of Co3O4 Nanoparticles in Dielectric Properties of Cu0.5Tl0.5Ba2Ca2Cu3O10-δ Superconducting Phase

NASA Astrophysics Data System (ADS)

Imran, M.; Mumtaz, M.; Naveed, M.; Khan, M. Nasir

2018-04-01

Cobalt oxide (Co3O4) nanoparticles and Cu0.5Tl0.5Ba2Ca2Cu3O10-δ (CuTl-1223) superconducting phase were prepared by sol-gel and solid-state reaction methods, respectively. Co3O4 nanoparticles were added in CuTl-1223 superconducting matrix to get (Co3O4)x/CuTl-1223, x = 0-2.0 wt.%, nanoparticles-superconductor composites. The unchanged crystal structure of the host CuTl-1223 superconducting phase (i.e. tetragonal) revealed that Co3O4 nanoparticles were settled at the grain boundaries. Superconducting properties of the CuTl-1223 phase were overall suppressed due to hole-charge carriers interaction at the grain boundaries. The dielectric properties of (Co3O4)x/CuTl-1223 composites were investigated by varying the test frequencies from 40 Hz to 100 MHz and operating temperatures from 77 to 298 K. The values of dielectric properties were found maximal at lower frequencies and started to decrease at higher frequencies. So, the dielectric properties of the CuTl-1223 superconducting phase can be tuned by varying the contents of (Co3O4) nanoparticles, test frequencies as well as operating temperatures.

Electron acceptor-based regulation of microbial greenhouse gas production from thawing permafrost

NASA Astrophysics Data System (ADS)

Bak, Ebbe; Jones, Eleanor; Yde, Jacob; Hodson, Andy; Mallon, Gunnar; Fisnter, Kai

2017-04-01

Permafrost contains about 35% of the global soil organic carbon (0-3 m depth). As a consequence of global warming, the active layer thickness is steadily increasing and its organic carbon is becoming available for degradation, causing a concomitant release of CO2 and CH4. The climate forcing feedbacks of permafrost thaw are determined by the rate of organic carbon degradation and to which degree it is released as CO2 or CH4. Methane is produced under anoxic conditions, but the factors that regulate its production are poorly constrained. In this study, we investigate how CH4 production is influenced by the presence of competing anaerobic processes with focus on the role of iron and sulfate reduction. We have collected permafrost cores to 2.2 meters depth from three different lowland sites in Adventdalen on Svalbard. From these cores, we have prepared anoxic batch incubation for each 25 cm depth interval and followed the production of CO2 and CH4 as well as the iron and sulfate reduction. This approach allows us to monitor the rate of the CO2 and CH4 production as well as to investigate the correlation between CH4 production and competing anaerobic respiration processes in the active layer as well in the permafrost. These investigations are accompanied by characterization of the carbon, iron and sulfate content in the soil and will be followed by characterization of the microbial community structure. The aim of this study is to get a better understanding of how the availability of sulfate and iron and the microbial community structure regulate the production of CO2 and CH4 in thawing permafrost, and to elucidate how the rate of the organic carbon degradation changes with depth in permafrost-affected soils. This study improves our understanding of climate feedback mechanisms operating during permafrost thaw.

Human expiration content diagnostics by tunable diode lasers in middle infrared

NASA Astrophysics Data System (ADS)

Kouznetsov, Andrian I.; Moskalenko, Konstantin L.; Nadezhdinskii, Alexander I.; Stepanov, Eugene V.

1992-04-01

Results on the application of tunable diode laser gas analysis to determining the trace components of human breath are presented. Schemes of the analyzers specially developed for measurement of both carbon oxides in expiration are described. A few results illuminating possible applications of TDL in high sensitive medical diagnostics have been obtained. For nonsmokers, the expired concentration of CO is slightly higher than inhaled air. Specific surplus value depends on the person's age. The surplus CO content increased significantly just after intensive physical exercises like jogging. For smokers, the farmacokinetical curve of abundant CO removal from the organism could be investigated. The smoking status of tested individuals becomes easy available. Breath-hold simultaneous measurements of CO and CO2 have shown the difference in the dependencies of their concentrations on breath-holding time. The possibility to investigate phenomena like molecular pulmonary diffusion of the alveolar-capillary membrane and an organism's compensation reactions to oxygen shortage seems to become real. Perspective leads for development and the application of diode laser spectroscopy methods to the analysis of gaseous microimpurities in medicine are also discussed.

Modeling Potential Carbon Monoxide Exposure Due to Operation of a Major Rocket Engine Altitude Test Facility Using Computational Fluid Dynamics

NASA Technical Reports Server (NTRS)

Blotzer, Michael J.; Woods, Jody L.

2009-01-01

This viewgraph presentation reviews computational fluid dynamics as a tool for modelling the dispersion of carbon monoxide at the Stennis Space Center's A3 Test Stand. The contents include: 1) Constellation Program; 2) Constellation Launch Vehicles; 3) J2X Engine; 4) A-3 Test Stand; 5) Chemical Steam Generators; 6) Emission Estimates; 7) Located in Existing Test Complex; 8) Computational Fluid Dynamics; 9) Computational Tools; 10) CO Modeling; 11) CO Model results; and 12) Next steps.

21 CFR 821.25 - Device tracking system and content requirements: manufacturer requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... manufacturer of a tracked device shall keep current records in accordance with its standard operating procedure... this section. A manufacturer shall make this standard operating procedure available to FDA upon request. A manufacturer shall incorporate the following into the standard operating procedure: (1) Data...

21 CFR 821.25 - Device tracking system and content requirements: manufacturer requirements.

Code of Federal Regulations, 2012 CFR

2012-04-01

... manufacturer of a tracked device shall keep current records in accordance with its standard operating procedure... this section. A manufacturer shall make this standard operating procedure available to FDA upon request. A manufacturer shall incorporate the following into the standard operating procedure: (1) Data...

21 CFR 821.25 - Device tracking system and content requirements: manufacturer requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... manufacturer of a tracked device shall keep current records in accordance with its standard operating procedure... this section. A manufacturer shall make this standard operating procedure available to FDA upon request. A manufacturer shall incorporate the following into the standard operating procedure: (1) Data...

21 CFR 821.25 - Device tracking system and content requirements: manufacturer requirements.

Code of Federal Regulations, 2013 CFR

2013-04-01

... manufacturer of a tracked device shall keep current records in accordance with its standard operating procedure... this section. A manufacturer shall make this standard operating procedure available to FDA upon request. A manufacturer shall incorporate the following into the standard operating procedure: (1) Data...

Dry co-digestion of sewage sludge and rice straw under mesophilic and thermophilic anaerobic conditions.

PubMed

Chu, Xiangqian; Wu, Guangxue; Wang, Jiaquan; Hu, Zhen-Hu

2015-12-01

Dry anaerobic digestion of sewage sludge can recover biogas as energy; however, its low C/N ratio limits it as a single substrate in the anaerobic digestion. Rice straw is an abundant agricultural residue in China, which is rich in carbon and can be used as carbon source. In the present study, the performance of dry co-digestion of sewage sludge and rice straw was investigated under mesophilic (35 °C) and thermophilic (55 °C) conditions. The operational factors impacting dry co-digestion of sewage sludge and rice straw such as C/N ratio, moisture content, and initial pH were explored under mesophilic conditions. The results show that low C/N ratios resulted in a higher biogas production rate, but a lower specific biogas yield; low moisture content of 65 % resulted in the instability of the digestion system and a low specific biogas yield. Initial pH ranging 7.0-9.0 did not affect the performance of the anaerobic digestion. The C/N ratio of 26-29:1, moisture content of 70-80 %, and pH 7.0-9.0 resulted in good performance in the dry mesophilic co-digestion of sewage sludge and rice straw. As compared with mesophilic digestion, thermophilic co-digestion of sewage sludge and rice straw significantly enhanced the degradation efficiency of the substrates and the specific biogas yield (p < 0.05) at the conditions of C/N ratio 26:1, moisture content 80 %, and natural initial pH. Although high concentrations of ammonia-nitrogen (NH4-N, 1500 mg/kg wet weight) were formed during thermophilic digestion, there was no obvious inhibition occurred. The results indicated that rice straw can be used as carbon source for the dry co-digestion of sewage sludge under mesophilic and thermophilic conditions.

Effect of different crops on soil organic matter and biological activity in Oxisols under three different crops

NASA Astrophysics Data System (ADS)

Toledo, Diana Marcela; Arzuaga, Silvia; Dalurzo, Humberto; Zornoza, Raúl; Vazquez, Sara

2015-04-01

The objective of this work was to evaluate changes in soil organic matter in Oxisols under different crops compared to native rainforest, and to assess if acid phosphatase activity (APA) could be a good indicator for SOC changes and soil quality. The experimental design consisted of four completely randomized blocks with four treatments: subtropical rainforest (F); yerba mate crop (I) (Ilex paraguariensis SH.); citrus crop (C) (Citrus unshiu Marc); and tobacco crop (T) (Nicotiana tabacum L.). Soil samples were taken at 0-10; 10-20 and 20-30 cm depths. The variables measured were soil organic carbon (SOC), APA, clay content, pH, total nitrogen (Nt), available phosphorus (P) and CO2 emissions. All data were analyzed by ANOVA to assess the effects of land-use changes. The treatment means were compared through Duncan's multiple range tests (p<0.05). The relationship between variables was determined with a simple correlation analysis and with a multiple linear regression analysis through the stepwise method. These soils showed an acid reaction and their clay content was over 650 g kg-1 for the three depths. SOC and N contents were higher in native soils, intermediate for the citrus crop, and lower under both tobacco and yerba mate crops. CO2 emissions were higher in the rainforest (47.32 kg ha-1 of CO2) than in cultivated soils, which indicates that biological activity is enhanced in rainforest soils where substrates for soil biota and fauna are more readily available. The variability of 76% in APA was explained by total nitrogen, which is closely related to soil organic matter, and by available P. Conversion of subtropical rainforests into agricultural lands reduced SOC content and acid phosphatase activity, thereby lowering soil quality. In this study, acid phosphatase activity proved to be a sensitive indicator to detect changes from pristine to cropped soils, but it failed to distinguish differences among crop systems.

2-micron Double Pulsed IPDA Lidar for Atmospheric CO2 Measurement

NASA Astrophysics Data System (ADS)

Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan; Murchison, Luke; Scola, Tory

2015-04-01

We have developed a high energy pulsed 2-micron IPDA lidar instrument to measure the atmospheric CO2 column density. The IPDA lidar is operated on the long wavelength wing of R(30) CO2 line at 2050.967 nm (4875.749 cm-1) in the side-line operation mode. The R(30) line is an excellent absorption line for the measurements of CO2 in 2µm wavelength region with regard to the strength of the absorption lines, low susceptibility to atmospheric temperature variability, and freedom from problematic interference with other absorption lines. The Ho:Tm:YLF laser transmitter is designed to be operated in a unique double pulse format that can produce two-pulse pair in 10 Hz operation. Typically, the output energies of the laser transmitter are 100mJ and 45mJ for the first pulse and the second pulse, respectively. We injection seed the first pulse with on-line frequency and the second pulse with off-line frequency. The IPDA lidar instrument size, weight and power consumption were restricted to small research aircraft payload requirements. The airborne IPDA lidar instrument measures the total integrated column content of CO2 from the instrument to the ground but with weighting that can be tuned by controlling the transmitted wavelengths. Therefore, the transmitter could be tuned to weight the column measurement to the surface for optimum CO2 interaction studies or up to the free troposphere for optimum transport studies. The 2-μm CO2 IPDA lidar airborne demonstration was conducted during March 20, 2014 through April 10, 2014. IPDA lidar airborne flights included various operating and environmental conditions. Environmental conditions included different flight altitude up to 8.3 km, different ground target conditions such as vegetation, soil, ocean, snow and sand and different cloud conditions. Besides, some flights targeted power plant incinerators for investigating the IPDA sensitivity to CO2 plums. The lidar instrument is robust during all of the flights. This paper describes the development of the new 2-micron pulsed IPDA lidar instrument, and presents the initial data for the airborne measurements of atmospheric CO2 concentration.

Education and Primary Health Care. UNESCO-UNICEF Co-operative Programme Digest No. 17.

ERIC Educational Resources Information Center

Jabre, Bushra

This digest concentrates on UNICEF's program priorities and summarizes the contents of the first 17 issues of its series on education and primary health care (PHC). Chapter I offers an introduction to PHC. Chapter II describes UNICEF's child health revolution, focusing on the direct and immediate interventions of growth monitoring, oral…

Children's Literature in the Service of International Understanding and Peaceful Co-Operation (Tehran, Iran, May 15-21, 1975).

ERIC Educational Resources Information Center

Institute for the Intellectual Development of Children and Young Adults, Tehran (Iran).

This report, given at a special meeting held in Tehran, summarizes general debate concerning the present situation of children's literature, the outlook on children's books, the content of children's books (the role of cultural traditions and illustrations), the preparation of children's books, the reinforcement of cooperation among nations, and…

Bioelectrochemical removal of carbon dioxide (CO2): an innovative method for biogas upgrading.

PubMed

Xu, Heng; Wang, Kaijun; Holmes, Dawn E

2014-12-01

Innovative methods for biogas upgrading based on biological/in-situ concepts have started to arouse considerable interest. Bioelectrochemical removal of CO2 for biogas upgrading was proposed here and demonstrated in both batch and continuous experiments. The in-situ biogas upgrading system seemed to perform better than the ex-situ one, but CO2 content was kept below 10% in both systems. The in-situ system's performance was further enhanced under continuous operation. Hydrogenotrophic methanogenesis and alkali production with CO2 absorption could be major contributors to biogas upgrading. Molecular studies showed that all the biocathodes associated with biogas upgrading were dominated by sequences most similar to the same hydrogenotrophic methanogen species, Methanobacterium petrolearium (97-99% sequence identity). Conclusively, bioelectrochemical removal of CO2 showed great potential for biogas upgrading. Copyright © 2014 Elsevier Ltd. All rights reserved.

Increased iron availability resulting from increased CO2 enhances carbon and nitrogen metabolism in the economical marine red macroalga Pyropia haitanensis (Rhodophyta).

PubMed

Chen, Binbin; Zou, Dinghui; Yang, Yufeng

2017-04-01

Ocean acidification caused by rising CO 2 is predicted to increase the concentrations of dissolved species of Fe(II) and Fe(III), leading to the enhanced photosynthetic carbon sequestration in some algal species. In this study, the carbon and nitrogen metabolism in responses to increased iron availability under two CO 2 levels (390 μL L -1 and 1000 μL L -1 ), were investigated in the maricultivated macroalga Pyropia haitanensis (Rhodophyta). The results showed that, elevated CO 2 increased soluble carbonhydrate (SC) contents, resulting from enhanced photosynthesis and photosynthetic pigment synthesis in this algae, but declined its soluble protein (SP) contents, resulting in increased ratio of SC/SP. This enhanced photosynthesis performance and carbon accumulation was more significant under iron enrichment condition in seawater, with higher iron uptake rate at high CO 2 level. As a key essential biogenic element for algae, Fe-replete functionally contributed to P. haitanensis photosynthesis. Increased SC fundamentally provided carbon skeletons for nitrogen assimilation. The significant increase of carbon and nitrogen assimilation finally contributed to enhanced growth in this alga. This was also intuitively reflected by respiration that provided energy for cellular metabolism and algal growth. We propose that, in the predicted scenario of rising atmospheric CO 2 , P. haitanensis is capable to adjust its physiology by increasing its carbon and nitrogen metabolism to acclimate the acidified seawater, at the background of global climate change and simultaneously increased iron concentration due to decreased pH levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Glue ear: how good is the information on the World Wide Web?

PubMed

Ritchie, L; Tornari, C; Patel, P M; Lakhani, R

2016-02-01

This paper objectively evaluates current information available to the general public related to glue ear on the World Wide Web. The term 'glue ear' was typed into the 3 most frequently used internet search engines - Google, Bing and Yahoo - and the first 20 links were analysed. The first 400 words of each page were used to calculate the Flesch-Kincaid readability score. Each website was subsequently graded using the Discern instrument, which gauges quality and content of literature. The websites Webmd.boots.com, Bupa.co.uk and Patient.co.uk received the highest overall scores. These reflected top scores in either readability or Discern instrument assessment, but not both. Readability and Discern scores increased with the presence of a marketing or advertising incentive. The Patient.co.uk website had the highest Discern score and third highest readability score. There is huge variation in the quality of information available to patients on the internet. Some websites may be accessible to a wide range of reading ages but have poor quality content, and vice versa. Clinicians should be aware of indicators of quality, and use validated instruments to assess and recommend literature.

Methane and carbon dioxide flux in the profile of wood ant (Formica aquilonia) nests and the surrounding forest floor during a laboratory incubation.

PubMed

Jílková, Veronika; Picek, Tomáš; Šestauberová, Martina; Krištůfek, Václav; Cajthaml, Tomáš; Frouz, Jan

2016-10-01

We compared methane (CH4) and carbon dioxide (CO2) fluxes in samples collected from the aboveground parts of wood ant nests and in the organic and mineral layer of the surrounding forest floor. Gas fluxes were measured during a laboratory incubation, and microbial properties (abundance of fungi, bacteria and methanotrophic bacteria) and nutrient contents (total and available carbon and nitrogen) were also determined. Both CO2 and CH4 were produced from ant nest samples, indicating that the aboveground parts of wood ant nests act as sources of both gases; in comparison, the forest floor produced about four times less CO2 and consumed rather than produced CH4 Fluxes of CH4 and CO2 were positively correlated with contents of available carbon and nitrogen. The methanotrophic community was represented by type II methanotrophic bacteria, but their abundance did not explain CH4 flux. Fungal abundance was greater in ant nest samples than in forest floor samples, but bacterial abundance was similar in both kinds of samples, suggesting that the organic materials in the nests may have been too recalcitrant for bacteria to decompose. The results indicate that the aboveground parts of wood ant nests are hot spots of CO2 and CH4 production in the forest floor. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Electrodeposited Ni-Co films from electrolytes with different Co contents

NASA Astrophysics Data System (ADS)

Karpuz, Ali; Kockar, Hakan; Alper, Mursel; Karaagac, Oznur; Haciismailoglu, Murside

2012-02-01

The properties of electrodeposited Ni-Co films produced from electrolyte consisted of nickel sulfamate, cobalt sulfate and boric acid were investigated as a function of Co content in the films. The compositional analysis performed by an energy dispersive X-ray spectroscopy demonstrated that the Co content of the films increases as the cobalt sulfate concentration in the electrolyte increases. The anomalous codeposition behavior was observed for all concentrations. The crystal structure was analyzed using an X-ray diffraction technique. The face centered cubic (fcc) structure was observed in the films containing from 0 at.% Co to 58 at.% Co. For the higher atomic Co contents (64 at.% and 80 at.%), a mixed phase of dominantly fcc and hexagonal closed packed (hcp) structure was observed although the (10.0) and (10.1) hcp peaks had minor intensities in the patterns. Surface micrographs obtained from a scanning electron microscope revealed that the film surface has a rougher appearance as the Co content increases. Magnetic measurements showed that the saturation magnetization gradually increased with increasing Co content of the films. The coercivity, Hc can be controlled by the structural parameters such as average grain size and crystal structure. The results also indicated that the optimum film composition was 28-40 at.% Co since the lower Hc and higher magnetoresistance (MR) values with very smooth or slightly granular surfaces were achieved at this Co content. It is revealed that Co content has an important effect on structural, magnetic and MR properties of the Ni-Co films.

Impact of methanol-gasoline fuel blend on the fuel consumption and exhaust emission of a SI engine

NASA Astrophysics Data System (ADS)

Rifal, Mohamad; Sinaga, Nazaruddin

2016-04-01

In this study, the effect of methanol-gasoline fuel blend (M15, M30 and M50) on the fuel consumption and exhaust emission of a spark ignition engine (SI) were investigated. In the experiment, an engine four-cylinder, four stroke injection system (engine of Toyota Kijang Innova 1TR-FE) was used. Test were did to know the relation of fuel consumption and exhaust emission (CO, CO2, HC) were analyzed under the idle throttle operating condition and variable engine speed ranging from 1000 to 4000 rpm. The experimental result showed that the fuel consumption decrease with the use of methanol. It was also shown that the CO and HC emission were reduced with the increase methanol content while CO2 were increased.

sCO2 Power Cycles Summit Summary November 2017.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendez Cruz, Carmen Margarita; Rochau, Gary E.; Lance, Blake

Over the past ten years, the Department of Energy (DOE) has helped to develop components and technologies for the Supercritical Carbon Dioxide (sCO2) power cycle capable of efficient operation at high temperatures and high efficiency. The DOE Offices of Fossil Energy, Nuclear Energy, and Energy Efficiency and Renewable Energy collaborated in the planning and execution of the sCO2 Power Cycle Summit conducted in Albuquerque, NM in November 2017. The summit brought together participants from government, national laboratories, research, and industry to engage in discussions regarding the future of sCO 2 Power Cycles Technology. This report summarizes the work involved inmore » summit planning and execution, before, during, and after the event, including the coordination between three DOE offices and technical content presented at the event.« less

Soil Mesocosm CO2 Emissions after 13C-glucose Addition, Soil Physical and Chemical Characteristics, and Microbial Biomass, Barrow, Alaska, 2014-2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lydia Vaughn; Biao Zhu; Carolin Bimueller

Measurements made from a 2014-2016 field glucose addition experiment. Dataset includes measurements of surface trace gas emissions (Delta13C of ecosystem respiration and source-partitioned surface CO2 flux, CH4 flux, and GPP), soil profile information (concentrations of carbon, nitrogen, and soil microbial biomass carbon, Delta13C of soil organic matter and microbial biomass, gravimetric water content, and bulk density), soil mineral nitrogen availability, and field-measured soil temperature, air temperature and soil moisture. Experiment was conducted in a region of high-centered polygons on the BEO. Data will be available Fall 2017.

Enhanced Ethanol Production from De-Ashed Paper Sludge by Simultaneous Saccharification and Fermentation and Simultaneous Saccharification and Co-Fermentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, L.; Wang, W.; Pallapolu, V. R.

2011-11-01

A previous study demonstrated that paper sludges with high ash contents can be converted to ethanol by simultaneous saccharification and fermentation (SSF) or simultaneous saccharification and co-fermentation (SSCF). High ash content in the sludge, however, limited solid loading in the bioreactor, causing low product concentration. To overcome this problem, sludges were de-ashed before SSF and SSCF. Low ash content in sludges also increased the ethanol yield to the extent that the enzyme dosage required to achieve 70% yield in the fermentation process was reduced by 30%. High solid loading in SSF and SSCF decreased the ethanol yield. High agitation andmore » de-ashing of the sludges were able to restore the part of the yield loss caused by high solid loading. Substitution of the laboratory fermentation medium (peptone and yeast extract) with corn steep liquor did not bring about any adverse effects in the fermentation. Fed-batch operation of the SSCF and SSF using low-ash content sludges was effective in raising the ethanol concentration, achieving 47.8 g/L and 60.0 g/L, respectively.« less

Investigation of La xSr 1-xCo yM 1-yO 3-δ (M = Mn Fe) perovskite materials as thermochemical energy storage media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Babiniec, Sean Michael; Coker, Eric Nicholas; Miller, James E.

2015-06-23

Materials in the La xSr 1–xCo yMn 1–yO 3–δ (LSCM) and La xSr 1–xCo yFe 1–yO 3–δ (LSCF) families are candidates for high-temperature thermochemical energy storage due to their facility for cyclic endothermic reduction and exothermic oxidation. A set of 16 LSCM and 21 LSCF compositions were synthesized by a modified Pechini method and characterized by powder X-ray diffraction and thermogravimetric analysis. All materials were found to be various symmetries of the perovskite phase. LSCM was indexed as tetragonal, cubic, rhombohedral, or orthorhombic as a function of increased lanthanum content. For LSCF, compositions containing low lanthanum content were indexed asmore » cubic while materials with high lanthanum content were indexed as rhombohedral. An initial screening of redox activity was completed by thermogravimetric analysis for each composition. The top three compositions with the greatest recoverable redox capacity for each family were further characterized in equilibrium thermogravimetric experiments over a range of temperatures and oxygen partial pressures. As a result, these equilibrium experiments allowed the extraction of thermodynamic parameters for LSCM and LSCF compositions operated in thermochemical energy storage conditions.« less

Characterizing differences in the phosphorus activation coefficient of three typical cropland soils and the influencing factors under long-term fertilization.

PubMed

Wu, Qihua; Zhang, Shuxiang; Zhu, Ping; Huang, Shaomin; Wang, Boren; Zhao, LinPing; Xu, Minggang

2017-01-01

The phosphorus activation coefficient (PAC, the ratio of available P to total P) is an important indicator of soil P availability and the transformation of P fractions. Understanding the details of the PAC is useful to estimate soil available P status and to provide P management guidance. In this research, soils from five long-term (23 years) fertilization treatments in three croplands were selected to examine the relationships between the PAC and P fractions and to analyse the influencing factors. PAC was affected by both soil types and fertilization treatments. Compared to the unfertilized control (CK) treatment, long-term P application significantly increased the PAC, all of the inorganic P (Pi) fractions and most of the organic P (Po) fractions in all the three soils, particularly in chemical fertilizer combined with manure treatment (NPKM). The PAC was significantly correlated to all of the Pi fractions proportions (P<0.05) except for Dil. HCl-Pi and Conc. HCl-Pi. Compared with CK, the chemical P and chemical P combined with manure treatments increased the ratio of total Pi fractions to total Po fractions (Pit/Pot); furthermore, NPKM significantly increased the organic C (Co) content and decreased the Co/Pot ratio. Stepwise multiple regressions showed that PAC = 0.93 Co+0.69 Pit/Pot-0.07 Co/Pot-0.27CaCO3-3.79 (R2 = 0.924, P<0.001). In addition, the variance partitioning analysis showed that more variance of PAC is explained by soil factors (29.53%) than by P input (0.19%) and climate (0.25%) factors. Our findings demonstrate that P application increased the PAC by changing the Co content and the proportion of P fractions. Moreover, soil factors were the most important drivers of P transformations, and NPKM was optimal for improving soil fertility in Chinese croplands.

Characterizing differences in the phosphorus activation coefficient of three typical cropland soils and the influencing factors under long-term fertilization

PubMed Central

Wu, Qihua; Zhang, Shuxiang; Zhu, Ping; Huang, Shaomin; Wang, Boren; Zhao, LinPing; Xu, Minggang

2017-01-01

The phosphorus activation coefficient (PAC, the ratio of available P to total P) is an important indicator of soil P availability and the transformation of P fractions. Understanding the details of the PAC is useful to estimate soil available P status and to provide P management guidance. In this research, soils from five long-term (23 years) fertilization treatments in three croplands were selected to examine the relationships between the PAC and P fractions and to analyse the influencing factors. PAC was affected by both soil types and fertilization treatments. Compared to the unfertilized control (CK) treatment, long-term P application significantly increased the PAC, all of the inorganic P (Pi) fractions and most of the organic P (Po) fractions in all the three soils, particularly in chemical fertilizer combined with manure treatment (NPKM). The PAC was significantly correlated to all of the Pi fractions proportions (P<0.05) except for Dil. HCl-Pi and Conc. HCl-Pi. Compared with CK, the chemical P and chemical P combined with manure treatments increased the ratio of total Pi fractions to total Po fractions (Pit/Pot); furthermore, NPKM significantly increased the organic C (Co) content and decreased the Co/Pot ratio. Stepwise multiple regressions showed that PAC = 0.93 Co+0.69 Pit/Pot-0.07 Co/Pot-0.27CaCO3-3.79 (R2 = 0.924, P<0.001). In addition, the variance partitioning analysis showed that more variance of PAC is explained by soil factors (29.53%) than by P input (0.19%) and climate (0.25%) factors. Our findings demonstrate that P application increased the PAC by changing the Co content and the proportion of P fractions. Moreover, soil factors were the most important drivers of P transformations, and NPKM was optimal for improving soil fertility in Chinese croplands. PMID:28467425

The relative availability of inorganic carbon and inorganic nitrogen influences the response of the dinoflagellate Protoceratium reticulatum to elevated CO2.

PubMed

Pierangelini, Mattia; Raven, John A; Giordano, Mario

2017-04-01

This work originates from three facts: (i) changes in CO 2 availability influence metabolic processes in algal cells; (ii) Spatial and temporal variations of nitrogen availability cause repercussions on phytoplankton physiology; (iii) Growth and cell composition are dependent on the stoichiometry of nutritional resources. In this study, we assess whether the impact of rising pCO 2 is influenced by N availability, through the impact that it would have on the C/N stoichiometry, in conditions of N sufficiency. Our experiments used the dinoflagellate Protoceratium reticulatum, which we cultured under three CO 2 regimes (400, 1,000, and 5,000 ppmv, pH of 8.1) and either variable (the NO 3 - concentration was always 2.5 mmol · L -1 ) or constant (NO 3 - concentration varied to maintain the same C i /NO 3 - ratio at all pCO 2 ) C i /NO 3 - ratio. Regardless of N availability, cells had higher specific growth rates, but lower cell dry weight and C and N quotas, at elevated CO 2 . The carbohydrate pool size and the C/N was unaltered in all treatments. The lipid content only decreased at high pCO 2 at constant C i /NO 3 - ratio. In the variable C i /NO 3 - conditions, the relative abundance of Rubisco (and other proteins) also changed; this did not occur at constant C i /NO 3 - . Thus, the biomass quality of P. reticulatum for grazers was affected by the C i /NO 3 - ratio in the environment and not only by the pCO 2 , both with respect to the size of the main organic pools and the composition of the expressed proteome. © 2016 Phycological Society of America.

10 000-hr Cyclic Oxidation Behavior of 68 High-Temperature Co-, Fe-, and Ni- Base Alloys Evaluated at 982 deg. C (1800 deg. F)

NASA Technical Reports Server (NTRS)

Barrett, Charles A.

1999-01-01

Power systems with operating temperatures in the range of 815 to 982 C (1500 to 1800 F) frequently require alloys that can operate for long times at these temperatures. A critical requirement is that these alloys have adequate oxidation resistance. The alloys used in these power systems require thousands of hours of operating life with intermittent shutdown to room temperature. Intermittent power plant shutdowns, however, offer the possibility that the protective scale will tend to spall (i.e., crack and flake off) upon cooling, increasing the rate of oxidative attack in subsequent heating cycles. Thus, it is critical that candidate alloys be evaluated for cyclic oxidation behavior. It was determined that exposing test alloys to ten 1000-hr cycles in static air at 982 10 000-hr Cyclic Oxidation Behavior of 68 High-Temperature Co-, Fe-, and Ni-Base Alloys Evaluated at 982 C (1800 F) could give a reasonable simulation of long-time power plant operation. Iron- (Fe-), nickel- (Ni-), and cobalt- (Co-) based high-temperature alloys with sufficient chromium (Cr) and/or aluminum (Al) content can exhibit excellent oxidation resistance. The protective oxides formed by these classes of alloys are typically Cr2O3 and/or Al2O3, and are usually influenced by their Cr, or Cr and Al, content. Sixty-eight Co-, Fe-, and Ni-base high-temperature alloys, typical of those used at this temperature or higher, were used in this study. At the NASA Lewis Research Center, the alloys were tested and compared on the basis of their weight change as a function of time, x-ray diffraction of the protective scale composition, and the physical appearance of the exposed samples. Although final appearance and x-ray diffraction of the final scale products were two factors used to evaluate the oxidation resistance of each alloy, the main criterion was the oxidation kinetics inferred from the specific weight change versus time data. These data indicated a range of oxidation behavior including parabolic (typical of isothermal oxidation), paralinear, linear, and mixed-linear kinetics.

Identifying best practices for audit committees.

PubMed

Burke, J V; Luecke, R W; Meeting, D

1996-06-01

Most healthcare organizations have an audit committee of the governing board, or a finance committee, that fulfills the audit oversight function. Financial managers play a key role in shaping the content, agency, and operation of the audit committee. The findings of a recent research study conducted by Arthur Anderson & Co., SC, into the best practices of audit committees have implications for healthcare organizations.

Transiting exoplanets from the CoRoT space mission . XIII. CoRoT-13b: a dense hot Jupiter in transit around a star with solar metallicity and super-solar lithium content

NASA Astrophysics Data System (ADS)

Cabrera, J.; Bruntt, H.; Ollivier, M.; Díaz, R. F.; Csizmadia, Sz.; Aigrain, S.; Alonso, R.; Almenara, J.-M.; Auvergne, M.; Baglin, A.; Barge, P.; Bonomo, A. S.; Bordé, P.; Bouchy, F.; Carone, L.; Carpano, S.; Deleuil, M.; Deeg, H. J.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Fridlund, M.; Gandolfi, D.; Gazzano, J.-C.; Gillon, M.; Guenther, E. W.; Guillot, T.; Hatzes, A.; Havel, M.; Hébrard, G.; Jorda, L.; Léger, A.; Llebaria, A.; Lammer, H.; Lovis, C.; Mazeh, T.; Moutou, C.; Ofir, A.; von Paris, P.; Pätzold, M.; Queloz, D.; Rauer, H.; Rouan, D.; Santerne, A.; Schneider, J.; Tingley, B.; Titz-Weider, R.; Wuchterl, G.

2010-11-01

We announce the discovery of the transiting planet CoRoT-13b. Ground-based follow-up in CFHT and IAC80 confirmed CoRoT's observations. The mass of the planet was measured with the HARPS spectrograph and the properties of the host star were obtained analyzing HIRES spectra from the Keck telescope. It is a hot Jupiter-like planet with an orbital period of 4.04 days, 1.3 Jupiter masses, 0.9 Jupiter radii, and a density of 2.34 g cm-3. It orbits a G0V star with T_eff = 5 945 K, M* = 1.09 M⊙, R_* = 1.01 R⊙, solar metallicity, a lithium content of + 1.45 dex, and an estimated age of between 0.12 and 3.15 Gyr. The lithium abundance of the star is consistent with its effective temperature, activity level, and age range derived from the stellar analysis. The density of the planet is extreme for its mass, implies that heavy elements are present with a mass of between about 140 and 300 {M}⊕. The CoRoT space mission, launched on December 27th 2006, has been developed and is operated by CNES, with the contribution of Austria, Belgium, Brazil, ESA (RSSD and Science Programme), Germany and Spain. Part of the observations were obtained at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Based on observations made with HARPS spectrograph on the 3.6-m European Organisation for Astronomical Research in the Southern Hemisphere telescope at La Silla Observatory, Chile (ESO program 184.C-0639). Based on observations made with the IAC80 telescope operated on the island of Tenerife by the Instituto de Astrofísica de Canarias in the Spanish Observatorio del Teide. Part of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

[Partial pressure of CO2 and CO2 degassing fluxes of Huayuankou and Xiaolangdi Station affected by Xiaolangdi Reservoir].

PubMed

Zhang, Yong-ling; Yang, Xiao-lin; Zhang, Dong

2015-01-01

According to periodic sampling analysis per month in Xiaolangdi station and Huayuankou station from November 2011 to October 2012, combined with continuous sampling analysis of Xiaolangdi Reservoir during runoff and sediment control period in 2012, partial pressure of CO2 (pCO2) in surface water were calculated based on Henry's Law, pCO2 features and air-water CO2 degassing fluxes of Huayuankou station and Xiaolangdi station affected by Xiaolangdi Reservoir were studied. The results were listed as follows, when Xiaolangdi Reservoir operated normally, pCO2 in surface water of Xiaolangdi station and Huayuankou station varied from 82 to 195 Pa and from 99 to 228 Pa, moreover, pCO2 in surface water from July to September were distinctly higher than those in other months; meanwhile, pCO, in surface water from Huayuankou station were higher than that from Xiaolangdi station. During runoff and sediment control period of Xiaolangdi Reservoir, two hydrological stations commonly indicated that pCO2 in surface water during water draining were obviously lower than those during sediment releasing. Whether in the period of normal operation or runoff and sediment control, pCO2 in surface water had positive relations to DIC content in two hydrological stations. Since the EpCO,/AOU value was higher than the theoretical value of 0. 62, the biological aerobic respiration effect had distinct contribution to pCO2. Throughout the whole year, air-water CO2 degassing fluxes from Xiaolangdi station and Huayuankou station were 0.486 p.mol (m2 s) -l and 0.588 pmol (m2 x s)(-1) respectively; When Xiaolangdi Reservoir operated normally, air-water CO, degassing fluxes in Huayuankou station were higher than that in Xiaolangdi station; during runoff and sediment control from Xiaolangdi Reservoir, two hydrological stations had one observation result in common, namely, air-water CO2 degassing fluxes in the period of water draining were obviously lower than that in the period of sediment releasing.

A Single-Culture Bioprocess of Methanothermobacter thermautotrophicus to Upgrade Digester Biogas by CO2-to-CH4 Conversion with H2

PubMed Central

Martin, Matthew R.; Fornero, Jeffrey J.; Angenent, Largus T.

2013-01-01

We optimized and tested a postbioprocessing step with a single-culture archaeon to upgrade biogas (i.e., increase methane content) from anaerobic digesters via conversion of CO2 into CH4 by feeding H2 gas. We optimized a culture of the thermophilic methanogen Methanothermobacter thermautotrophicus using: (1) a synthetic H2/CO2 mixture; (2) the same mixture with pressurization; (3) a synthetic biogas with different CH4 contents and H2; and (4) an industrial, untreated biogas and H2. A laboratory culture with a robust growth (dry weight of 6.4–7.4 g/L; OD600 of 13.6–15.4), a volumetric methane production rate of 21 L/L culture-day, and a H2 conversion efficiency of 89% was moved to an industrial anaerobic digester facility, where it was restarted and fed untreated biogas with a methane content of ~70% at a rate such that CO2 was in excess of the stoichiometric requirements in relation to H2. Over an 8-day operating period, the dry weight of the culture initially decreased slightly before stabilizing at an elevated level of ~8 g/L to achieve a volumetric methane production rate of 21 L/L culture-day and a H2 conversion efficiency of 62%. While some microbial contamination of the culture was observed via microscopy, it did not affect the methane production rate of the culture. PMID:24194675

Electrochemical alloying of immiscible Ag and Co for their structural and magnetic analyses

NASA Astrophysics Data System (ADS)

Santhi, Kalavathy; Kumarsan, Dhanapal; Vengidusamy, Naryanan; Arumainathan, Stephen

2017-07-01

Electrochemical alloying of immiscible Ag and Co was carried out at different current densities from electrolytes of two different concentrations, after optimizing the electrolytic bath and operating conditions. The samples obtained were characterized using X-ray diffraction to confirm the simultaneous deposition of Ag and Co and to determine their crystallographic structure. The atomic percentage of Ag and Co contents in the granular alloy was determined by ICP-OES analysis. The XPS spectra were observed to confirm the presence of Ag and Co in the metallic form in the granular alloy samples. The micrographs observed using scanning and transmission electron microscopes threw light on the surface morphology and the size of the particles. The magnetic nature of the samples was analyzed at room temperature by a vibration sample magnetometer. Their magnetic phase transition while heating was also studied to provide further evidence for the magnetic behaviour and the structure of the deposits.

An investigation of reaction parameters on geochemical storage of non-pure CO2 streams in iron oxides-bearing formations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, Susana; Liu, Q.; Bacon, Diana H.

2014-08-26

Hematite deposit that is the main FeIII-bearing mineral in sedimentary red beds was proposed as a potential host repository for converting CO2 into carbonate minerals such as siderite (FeCO3), when CO2–SO2 gas mixtures are co-injected. This work investigated CO2 mineral trapping using hematite and sensitivity of the reactive systems to different parameters, including particle size, gas composition, temperature, pressure, and solid-to-liquid ratio. Experimental and modelling studies of hydrothermal experiments were conducted, which emulated a CO2 sequestration scenario by injecting CO2-SO2 gas streams into a NaCl-NaOH brine hosted in iron oxide-containing aquifer. This study provides novel information on the mineralogical changesmore » and fluid chemistry derived from the co-injection of CO2-SO2 gas mixtures in hematite deposit. It can be concluded that the amount of siderite precipitate depends primarily on the SO2 content of the gas stream. Increasing SO2 content in the system could promote the reduction of Fe3+ from the hematite sample to Fe2+, which will be further available for its precipitation as siderite. Moreover, siderite precipitation is enhanced at low temperatures and high pressures. The influence of the solid to liquid ratio on the overall carbonation reaction suggests that the conversion increases if the system becomes more diluted.« less

40 CFR 89.312 - Analytical gases.

Code of Federal Regulations, 2012 CFR

2012-07-01

... by dynamic blending. Nitrogen shall be the predominant diluent with the balance oxygen. (e) Fuel for... gases must be available for operation: (1) Purified nitrogen (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0.1 ppm NO) (2) [Reserved] (3) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance...

40 CFR 89.312 - Analytical gases.

Code of Federal Regulations, 2010 CFR

2010-07-01

... by dynamic blending. Nitrogen shall be the predominant diluent with the balance oxygen. (e) Fuel for... gases must be available for operation: (1) Purified nitrogen (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0.1 ppm NO) (2) [Reserved] (3) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance...

40 CFR 89.312 - Analytical gases.

Code of Federal Regulations, 2011 CFR

2011-07-01

... by dynamic blending. Nitrogen shall be the predominant diluent with the balance oxygen. (e) Fuel for... gases must be available for operation: (1) Purified nitrogen (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0.1 ppm NO) (2) [Reserved] (3) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance...

40 CFR 89.312 - Analytical gases.

Code of Federal Regulations, 2013 CFR

2013-07-01

... by dynamic blending. Nitrogen shall be the predominant diluent with the balance oxygen. (e) Fuel for... gases must be available for operation: (1) Purified nitrogen (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0.1 ppm NO) (2) [Reserved] (3) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance...

40 CFR 89.312 - Analytical gases.

Code of Federal Regulations, 2014 CFR

2014-07-01

... blending. Nitrogen shall be the predominant diluent with the balance oxygen. (e) Fuel for the FID shall be... be available for operation: (1) Purified nitrogen (Contamination ≤ 1 ppm C, ≤ 1 ppm CO, ≤ 400 ppm CO2, ≤ 0.1 ppm NO) (2) [Reserved] (3) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance helium...

Carbon monoxide sensor and method of use

DOEpatents

Dutta, Prabir K.; Swartz, Scott L.; Holt, Christopher T.; Revur, Ramachandra Rao

2006-01-10

A sensor and method of use for detection of low levels of carbon monoxide in gas mixtures. The approach is based on the change in an electrical property (for example: resistance) that occurs when carbon monoxide is selectively absorbed by a film of copper chloride (or other metal halides). The electrical property change occurs rapidly with both increasing and decreasing CO contents, varies with the amount of CO from the gas stream, and is insensitive to the presence of hydrogen. To make a sensor using this approach, the metal halide film will deposited onto an alumina substrate with electrodes. The sensor may be maintained at the optimum temperature with a thick film platinum heater deposited onto the opposite face of the substrate. When the sensor is operating at an appropriate (and constant) temperature, the magnitude of the electrical property measured between the interdigital electrodes will provide a measure of the carbon monoxide content of the gas.

Temporal changes in soil water repellency linked to the soil respiration and CH4 and CO2 fluxes

NASA Astrophysics Data System (ADS)

Qassem, Khalid; Urbanek, Emilia; van Keulen, Geertje

2014-05-01

Soil water repellency (SWR) is known to be a spatially and temporally variable phenomenon. The seasonal changes in soil moisture lead to development of soil water repellency, which in consequence may affect the microbial activity and in consequence alter the CO2 and CH4 fluxes from soils. Soil microbial activity is strongly linked to the temperature and moisture status of the soil. In terms of CO2 flux intermediate moisture contents are most favourable for the optimal microbial activity and highest CO2 fluxes. Methanogenesis occurs primarily in anaerobic water-logged habitats while methanotrophy is a strictly aerobic process. In the study we hypothesise that the changes in CO2 and CH4 fluxes are closely linked to critical moisture thresholds for soil water repellency. This research project aims to adopt a multi-disciplinary approach to comprehensively determine the effect of SWR on CO2 and CH4 fluxes. Research is conducted in situ at four sites exhibiting SWR in the southern UK. Flux measurements are carried out concomitant with meteorological and SWR observations Field observations are supported by laboratory measurements carried out on intact soil samples collected at the above identified field sites. The laboratory analyses are conducted under constant temperatures with controlled changes of soil moisture content. Methanogenic and Methanotrophic microbial populations are being analysed at different SWR and moisture contents using the latest metagenomic and metatranscriptomic approaches. Currently available data show that greenhouse gas flux are closely linked with soil moisture thresholds for SWR development.

BOREAS TE-10 Leaf Gas Exchange Data

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Middleton, Elizabeth; Sullivan, Joseph

2000-01-01

The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-10 (Terrestrial Ecology) team collected several data sets in support of its efforts to characterize and interpret information on the reflectance, transmittance, gas exchange, chlorophyll content, carbon content, hydrogen content, and nitrogen content of boreal vegetation. This data set contains measurements of assimilation, stomatal conductance, transpiration, internal CO2 concentration, and water use efficiency conducted in the Southern Study Area (SSA) during the growing seasons of 1994 and 1996 using a portable gas exchange system. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Dry anaerobic digestion of food waste and cardboard at different substrate loads, solid contents and co-digestion proportions.

PubMed

Capson-Tojo, Gabriel; Trably, Eric; Rouez, Maxime; Crest, Marion; Steyer, Jean-Philippe; Delgenès, Jean-Philippe; Escudié, Renaud

2017-06-01

The increasing food waste production calls for developing efficient technologies for its treatment. Anaerobic processes provide an effective waste valorization. The influence of the initial substrate load on the performance of batch dry anaerobic co-digestion reactors treating food waste and cardboard was investigated. The load was varied by modifying the substrate to inoculum ratio (S/X), the total solids content and the co-digestion proportions. The results showed that the S/X was a crucial parameter. Within the tested values (0.25, 1 and 4gVS·gVS -1 ), only the reactors working at 0.25 produced methane. Methanosarcina was the main archaea, indicating its importance for efficient methanogenesis. Acidogenic fermentation was predominant at higher S/X, producing hydrogen and other metabolites. Higher substrate conversions (≤48%) and hydrogen yields (≤62mL·gVS -1 ) were achieved at low loads. This study suggests that different value-added compounds can be produced in dry conditions, with the initial substrate load as easy-to-control operational parameter. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hypobaric Control of Ethylene-Induced Leaf Senescence in Intact Plants of Phaseolus vulgaris L. 1

PubMed Central

Nilsen, Karl N.; Hodges, Clinton F.

1983-01-01

A controlled atmospheric-environment system (CAES) designed to sustain normal or hypobaric ambient growing conditions was developed, described, and evaluated for its effectiveness as a research tool capable of controlling ethylene-induced leaf senescence in intact plants of Phaseolus vulgaris L. Senescence was prematurely-induced in primary leaves by treatment with 30 parts per million ethephon. Ethephon-derived endogenous ethylene reached peak levels within 6 hours at 26°C. Total endogenous ethylene levels then temporarily stabilized at approximately 1.75 microliters per liter from 6 to 24 hours. Thereafter, a progressive rise in ethylene resulted from leaf tissue metabolism and release. Throughout the study, the endogenous ethylene content of ethephon-treated leaves was greater than that of nontreated leaves. Subjecting ethephon-treated leaves to atmospheres of 200 millibars, with O2 and CO2 compositions set to approximate normal atmospheric partial pressures, prevented chlorophyll loss. Alternately, subjecting ethephon-treated plants to 200 millibars of air only partially prevented chlorophyll loss. Hypobaric conditions (200 millibars), with O2 and CO2 at normal atmospheric availability, could be delayed until 48 hours after ethephon treatment and still prevent most leaf senescence. In conclusion, hypobaric conditions established and maintained within the CAES prevented ethylene-induced senescence (chlorosis) in intact plants, provided O2 and CO2 partial pressures were maintained at levels approximating normal ambient availability. An unexpected increase in endogenous ethylene was detected within nontreated control leaves 48 hours subsequent to relocation from winter greenhouse conditions (latitude, 42°00″ N) to the CAES operating at normal ambient pressure. The longer photoperiod and/or higher temperature utilized within the CAES are hypothesized to influence ethylene metabolism directly and growth-promotive processes (e.g. response thresholds) indirectly. PMID:16662806

Control of Co content and SOFC cathode performance in Y1-ySr2+yCu3-xCoxO7+δ

NASA Astrophysics Data System (ADS)

Šimo, F.; Payne, J. L.; Demont, A.; Sayers, R.; Li, Ming; Collins, C. M.; Pitcher, M. J.; Claridge, J. B.; Rosseinsky, M. J.

2014-11-01

The electrochemical performance of the layered perovskite YSr2Cu3-xCoxO7+δ, a potential solid oxide fuel cell (SOFC) cathode, is improved by increasing the Co content from x = 1.00 to a maximum of x = 1.30. Single phase samples with x > 1.00 are obtained by tuning the Y/Sr ratio, yielding the composition Y1-ySr2+yCu3-xCoxO7+δ (where y ≤ 0.05). The high temperature structure of Y0.95Sr2.05Cu1.7Co1.3O7+δ at 740 °C is characterised by powder neutron diffraction and the potential of this Co-enriched material as a SOFC cathode is investigated by combining AC impedance spectroscopy, four-probe DC conductivity and powder XRD measurements to determine its electrochemical properties along with its thermal stability and compatibility with a range of commercially available electrolytes. The material is shown to be compatible with doped ceria electrolytes at 900 °C.

Co-electrolysis of steam and CO2 in full-ceramic symmetrical SOECs: a strategy for avoiding the use of hydrogen as a safe gas.

PubMed

Torrell, M; García-Rodríguez, S; Morata, A; Penelas, G; Tarancón, A

2015-01-01

The use of cermets as fuel electrodes for solid oxide electrolysis cells requires permanent circulation of reducing gas, e.g. H2 or CO, so called safe gas, in order to avoid oxidation of the metallic phase. Replacing metallic based electrodes by pure oxides is therefore proposed as an advantage for the industrial application of solid oxide electrolyzers. In this work, full-ceramic symmetrical solid oxide electrolysis cells have been investigated for steam/CO2 co-electrolysis. Electrolyte supported cells with La(0.75)Sr(0.25)Cr(0.5)Mn(0.5)O3-δ reversible electrodes have been fabricated and tested in co-electrolysis mode using different fuel compositions, from pure H2O to pure CO2, at temperatures between 850-900 °C. Electrochemical impedance spectroscopy and galvanostatic measurements have been carried out for the mechanistic understanding of the symmetrical cell performance. The content of H2 and CO in the product gas has been measured by in-line gas micro-chromatography. The effect of employing H2 as a safe gas has also been investigated. Maximum density currents of 750 mA cm(-2) and 620 mA cm(-2) have been applied at 1.7 V for pure H2O and for H2O : CO2 ratios of 1 : 1, respectively. Remarkable results were obtained for hydrogen-free fuel compositions, which confirmed the interest of using ceramic oxides as a fuel electrode candidate to reduce or completely avoid the use of safe gas in operation minimizing the contribution of the reverse water shift reaction (RWSR) in the process. H2 : CO ratios close to two were obtained for hydrogen-free tests fulfilling the basic requirements for synthetic fuel production. An important increase in the operation voltage was detected under continuous operation leading to a dramatic failure by delaminating of the oxygen electrode.

In situ experimental study of carbon monoxide generation by gasoline-powered electric generator in an enclosed space.

PubMed

Wang, Liangzhu; Emmerich, Steven J; Persily, Andrew K

2010-12-01

On the basis of currently available data, approximately 97% of generator-related carbon monoxide (CO) fatalities are caused by operating currently marketed, carbureted spark-ignited gasoline-powered generators (not equipped with emission controls) in enclosed spaces. To better understand and to reduce the occurrence of these fatalities, research is needed to quantify CO generation rates, develop and test CO emission control devices, and evaluate CO transport and exposure when operating a generator in an enclosed space. As a first step in these efforts, this paper presents measured CO generation rates from a generator without any emission control devices operating in an enclosed space under real weather conditions. This study expands on previously published information from the U.S. Consumer Product Safety Commission. Thirteen separate tests were conducted under different weather conditions at half and full generator load settings. It was found that the CO level in the shed reached a maximum value of 29,300 +/- 580 mg/m3, whereas the oxygen (O2) was depleted to a minimum level of 16.2 +/- 0.02% by volume. For the test conditions of real weather and generator operation, the CO generation and the O2 consumption could be expressed as time-averaged generation/consumption rates. It was also found that the CO generation and O2 consumption rates can be correlated to the O2 levels in the space and the actual load output from the generator. These correlations are shown to agree well with the measurements.

A study of the Al content impact on the properties of MmNi 4.4- xCo 0.6Al x alloys as precursors for negative electrodes in NiMH batteries

NASA Astrophysics Data System (ADS)

Bliznakov, S.; Lefterova, E.; Dimitrov, N.; Petrov, K.; Popov, A.

AB 5-type hydrogen storage alloys with MmNi 4.4- xCo 0.6Al x (Mm-mischmetal) composition are synthesized, structurally and thermodynamically characterized, and electrochemically tested in 6 M KOH electrolyte. It is shown that an increase of the Al content in the alloy results in expansion of both the alloy lattice cell size and the unit cell volume. These structural changes lead to decrease of the plateau pressure and increase of the plateau width in the pressure-composition-temperature desorption isotherms. Improvement of the specific electrode capacity is also registered with the increase of the cell parameters. In addition to that the higher Al content is found to enhance the stability of the alloy components' hydrides. Maximum discharge capacity of 278 mAh g -1 is measured with an electrode made from a MmNi 3.6Co 0.6Al 0.8 alloy. Cycle life tests of the accordingly prepared electrodes suggest a stability that is comparable to the stability of commercially available hydrogen storage electrodes.

Co-agonists differentially tune GluN2B-NMDA receptor trafficking at hippocampal synapses

PubMed Central

Ferreira, Joana S; Papouin, Thomas; Ladépêche, Laurent; Yao, Andrea; Langlais, Valentin C; Bouchet, Delphine; Dulong, Jérôme; Mothet, Jean-Pierre; Sacchi, Silvia; Pollegioni, Loredano; Paoletti, Pierre; Oliet, Stéphane Henri Richard; Groc, Laurent

2017-01-01

The subunit composition of synaptic NMDA receptors (NMDAR), such as the relative content of GluN2A- and GluN2B-containing receptors, greatly influences the glutamate synaptic transmission. Receptor co-agonists, glycine and D-serine, have intriguingly emerged as potential regulators of the receptor trafficking in addition to their requirement for its activation. Using a combination of single-molecule imaging, biochemistry and electrophysiology, we show that glycine and D-serine relative availability at rat hippocampal glutamatergic synapses regulate the trafficking and synaptic content of NMDAR subtypes. Acute manipulations of co-agonist levels, both ex vivo and in vitro, unveil that D-serine alter the membrane dynamics and content of GluN2B-NMDAR, but not GluN2A-NMDAR, at synapses through a process requiring PDZ binding scaffold partners. In addition, using FRET-based FLIM approach, we demonstrate that D-serine rapidly induces a conformational change of the GluN1 subunit intracellular C-terminus domain. Together our data fuels the view that the extracellular microenvironment regulates synaptic NMDAR signaling. DOI: http://dx.doi.org/10.7554/eLife.25492.001 PMID:28598327

Local Structure and Surface Properties of CoxZn1-xO Thin Films for Ozone Gas Sensing.

PubMed

Catto, Ariadne C; Silva, Luís F da; Bernardi, Maria Inês B; Bernardini, Sandrine; Aguir, Khalifa; Longo, Elson; Mastelaro, Valmor R

2016-10-05

A detailed study of the structural, surface, and gas-sensing properties of nanostructured Co x Zn 1-x O films is presented. X-ray diffraction (XRD) analysis revealed a decrease in the crystallization degree with increasing Co content. The X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopies (XPS) revealed that the Co 2+ ions preferentially occupied the Zn 2+ sites and that the oxygen vacancy concentration increased as the amount of cobalt increased. Electrical measurements showed that the Co dopants not only enhanced the sensor response at low ozone levels (ca. 42 ppb) but also led to a decrease in the operating temperature and improved selectivity. The enhancement in the gas-sensing properties was attributed to the presence of oxygen vacancies, which facilitated ozone adsorption.

Characteristics of Deepwater Seaports within the Continental United States.

DTIC Science & Technology

1984-09-01

Distribution/ Availabilit ? Co09 Avail and/or Dist speolal -V’. UNCLASSIFIED SECURITY CLASSIFICATION OP THIS PAGItUM Dae Eeffes~d) TABLE OF CONTENTS...depth (at mean low water ) alongside the terminal Vessel type served** The type of vessel accommodated by the terminal Cargo types*** The types of

Anaerobic slurry co-digestion of poultry manure and straw: effect of organic loading and temperature

PubMed Central

2013-01-01

In order to obtain basic design criteria for anaerobic digestion of a mixture of poultry manure and wheat straw, the effects of different temperatures and organic loading rates on the biogas yield and methane contents were evaluated. Since poultry manure is a poor substrate, in term of the availability of the nutrients, external supplementation of carbon has to be regularly performed, in order to achieve a stable and efficient process. The complete-mix, pilot-scale digester with working volume of 70 L was used. The digestion operated at 25°C, 30°C and 35°C with organic loading rates of 1.0, 2.0, 2.5, 3.0, 3.5 and 4.0 kg Volatile solid/m3d and a HRT of 15 days. At a temperature of 35°C, the methane yield was increased by 43% compared to 25°C. Anaerobic co-digestion appeared feasible with a loading rate of 3.0 kg VS/m3d at 35°C. At this state, the specific methane yield was calculated about 0.12 m3/kg VS with a methane content of 53–70.2% in the biogas. The volatile solid (VS) removal was 72%. As a result of volatile fatty acid accumulation and decrease in pH, when the loading rate was less than 1 or greater than 4 kg VS/m3d, the process was inhibited or overloaded, respectively. Both the lower and higher loading rates resulted in a decline in the methane yield. PMID:24502409

Rice grain yield and quality responses to free-air CO2 enrichment combined with soil and water warming.

PubMed

Usui, Yasuhiro; Sakai, Hidemitsu; Tokida, Takeshi; Nakamura, Hirofumi; Nakagawa, Hiroshi; Hasegawa, Toshihiro

2016-03-01

Rising air temperatures are projected to reduce rice yield and quality, whereas increasing atmospheric CO2 concentrations ([CO2 ]) can increase grain yield. For irrigated rice, ponded water is an important temperature environment, but few open-field evaluations are available on the combined effects of temperature and [CO2 ], which limits our ability to predict future rice production. We conducted free-air CO2 enrichment and soil and water warming experiments, for three growing seasons to determine the yield and quality response to elevated [CO2 ] (+200 μmol mol(-1) , E-[CO2 ]) and soil and water temperatures (+2 °C, E-T). E-[CO2 ] significantly increased biomass and grain yield by approximately 14% averaged over 3 years, mainly because of increased panicle and spikelet density. E-T significantly increased biomass but had no significant effect on the grain yield. E-T decreased days from transplanting to heading by approximately 1%, but days to the maximum tiller number (MTN) stage were reduced by approximately 8%, which limited the panicle density and therefore sink capacity. On the other hand, E-[CO2 ] increased days to the MTN stage by approximately 4%, leading to a greater number of tillers. Grain appearance quality was decreased by both treatments, but E-[CO2 ] showed a much larger effect than did E-T. The significant decrease in undamaged grains (UDG) by E-[CO2 ] was mainly the result of an increased percentage of white-base grains (WBSG), which were negatively correlated with grain protein content. A significant decrease in grain protein content by E-[CO2 ] accounted in part for the increased WBSG. The dependence of WBSG on grain protein content, however, was different among years; the slope and intercept of the relationship were positively correlated with a heat dose above 26 °C. Year-to-year variation in the response of grain appearance quality demonstrated that E-[CO2 ] and rising air temperatures synergistically reduce grain appearance quality of rice. © 2015 John Wiley & Sons Ltd.

Soil water availability and microsite mediate fungal and bacterial phospholipid fatty acid biomarker abundances in Mojave Desert soils exposed to elevated atmospheric CO2

NASA Astrophysics Data System (ADS)

Jin, V. L.; Schaeffer, S. M.; Ziegler, S. E.; Evans, R. D.

2011-06-01

Changes in the rates of nitrogen (N) cycling, microbial carbon (C) substrate use, and extracellular enzyme activities in a Mojave Desert ecosystem exposed to elevated atmospheric CO2 suggest shifts in the size and/or functional characteristics of microbial assemblages in two dominant soil microsites: plant interspaces and under the dominant shrub Larrea tridentata. We used ester-linked phospholipid fatty acid (PLFA) biomarkers as a proxy for microbial biomass to quantify spatial and temporal differences in soil microbial communities from February 2003 to May 2005. Further, we used the 13C signature of the fossil CO2 source for elevated CO2 plots to trace recent plant C inputs into soil organic matter (SOM) and broad microbial groups using δ13C (‰). Differences between individual δ13CPLFA and δ13CSOM for fungal biomarkers indicated active metabolism of newer C in elevated CO2 soils. Total PLFA-C was greater in shrub microsites compared to plant interspaces, and CO2 treatment differences within microsites increased under higher soil water availability. Total, fungal, and bacterial PLFA-C increased with decreasing soil volumetric water content (VWC) in both microsites, suggesting general adaptations to xeric desert conditions. Increases in fungal-to-bacterial PLFA-C ratio with decreasing VWC reflected functional group-specific responses to changing soil water availability. While temporal and spatial extremes in resource availability in desert ecosystems contribute to the difficulty in identifying common trends or mechanisms driving microbial responses in less extreme environments, we found that soil water availability and soil microsite interacted with elevated CO2 to shift fungal and bacterial biomarker abundances in Mojave Desert soils.

Carbon dioxide capture from atmospheric air using sodium hydroxide spray.

PubMed

Stolaroff, Joshuah K; Keith, David W; Lowry, Gregory V

2008-04-15

In contrast to conventional carbon capture systems for power plants and other large point sources, the system described in this paper captures CO2 directly from ambient air. This has the advantages that emissions from diffuse sources and past emissions may be captured. The objective of this research is to determine the feasibility of a NaOH spray-based contactor for use in an air capture system by estimating the cost and energy requirements per unit CO2 captured. A prototype system is constructed and tested to measure CO2 absorption, energy use, and evaporative water loss and compared with theoretical predictions. A numerical model of drop collision and coalescence is used to estimate operating parameters for a full-scale system, and the cost of operating the system per unit CO2 captured is estimated. The analysis indicates that CO2 capture from air for climate change mitigation is technically feasible using off-the-shelf technology. Drop coalescence significantly decreases the CO2 absorption efficiency; however, fan and pump energy requirements are manageable. Water loss is significant (20 mol H2O/mol CO2 at 15 degrees C and 65% RH) but can be lowered by appropriately designing and operating the system. The cost of CO2 capture using NaOH spray (excluding solution recovery and CO2 sequestration, which may be comparable) in the full-scale system is 96 $/ton-CO2 in the base case, and ranges from 53 to 127 $/ton-CO2 under alternate operating parameters and assumptions regarding capital costs and mass transfer rate. The low end of the cost range is reached by a spray with 50 microm mean drop diameter, which is achievable with commercially available spray nozzles.

ERMes: Open Source Simplicity for Your E-Resource Management

ERIC Educational Resources Information Center

Doering, William; Chilton, Galadriel

2009-01-01

ERMes, the latest version of electronic resource management system (ERM), is a relational database; content in different tables connects to, and works with, content in other tables. ERMes requires Access 2007 (Windows) or Access 2008 (Mac) to operate as the database utilizes functionality not available in previous versions of Microsoft Access. The…

Bench Scale Process for Low Cost CO 2 Capture Using a Phase-Changing Absorbent: Final Scientific/Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westendorf, Tiffany; Buddle, Stanlee; Caraher, Joel

The objective of this project is to design and build a bench-scale process for a novel phase-changing aminosilicone-based CO 2-capture solvent. The project will establish scalability and technical and economic feasibility of using a phase-changing CO 2-capture absorbent for post-combustion capture of CO 2 from coal-fired power plants. The U.S. Department of Energy’s goal for Transformational Carbon Capture Technologies is the development of technologies available for demonstration by 2025 that can capture 90% of emitted CO 2 with at least 95% CO 2 purity for less than $40/tonne of CO 2 captured. In the first budget period of the project,more » the bench-scale phase-changing CO2 capture process was designed using data and operating experience generated under a previous project (ARPA-e project DE-AR0000084). Sizing and specification of all major unit operations was completed, including detailed process and instrumentation diagrams. The system was designed to operate over a wide range of operating conditions to allow for exploration of the effect of process variables on CO 2 capture performance. In the second budget period of the project, individual bench-scale unit operations were tested to determine the performance of each of each unit. Solids production was demonstrated in dry simulated flue gas across a wide range of absorber operating conditions, with single stage CO 2 conversion rates up to 75mol%. Desorber operation was demonstrated in batch mode, resulting in desorption performance consistent with the equilibrium isotherms for GAP-0/CO 2 reaction. Important risks associated with gas humidity impact on solids consistency and desorber temperature impact on thermal degradation were explored, and adjustments to the bench-scale process were made to address those effects. Corrosion experiments were conducted to support selection of suitable materials of construction for the major unit operations in the process. The bench scale unit operations were assembled into a continuous system to support steady state system testing. In the third budget period of the project, continuous system testing was conducted, including closed-loop operation of the absorber and desober systems. Slurries of GAP-0/GAP-0 carbamate/water mixtures produced in the absorber were pumped successfully to the desorber unit, and regenerated solvent was returned to the absorber. A techno-economic analysis, EH&S risk assessment, and solvent manufacturability study were completed.« less

Chado Controller: advanced annotation management with a community annotation system

PubMed Central

Guignon, Valentin; Droc, Gaëtan; Alaux, Michael; Baurens, Franc-Christophe; Garsmeur, Olivier; Poiron, Claire; Carver, Tim; Rouard, Mathieu; Bocs, Stéphanie

2012-01-01

Summary: We developed a controller that is compliant with the Chado database schema, GBrowse and genome annotation-editing tools such as Artemis and Apollo. It enables the management of public and private data, monitors manual annotation (with controlled vocabularies, structural and functional annotation controls) and stores versions of annotation for all modified features. The Chado controller uses PostgreSQL and Perl. Availability: The Chado Controller package is available for download at http://www.gnpannot.org/content/chado-controller and runs on any Unix-like operating system, and documentation is available at http://www.gnpannot.org/content/chado-controller-doc The system can be tested using the GNPAnnot Sandbox at http://www.gnpannot.org/content/gnpannot-sandbox-form Contact: valentin.guignon@cirad.fr; stephanie.sidibe-bocs@cirad.fr Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22285827

Systematic Co-Operation between Theory and Practice in Mathematics Education. Mini-Conference at ICME 5. Topic Area Research and Teaching (Adelaide, Australia, August 25-29, 1984).

ERIC Educational Resources Information Center

Christiansen, Bent; And Others

A miniconference (consisting of four 60-minute sessions) was organized to contribute to the exploration of frames, forms, and contents of systematic cooperation and interaction between the researcher and teacher in the classroom. These proceedings of the conference include descriptions of the organization, purpose, and background of the…

Digital Dividend Aware Business Models for the Creative Industries: Challenges and Opportunities in EU Markets

NASA Astrophysics Data System (ADS)

Cossiavelou, Vassiliki

EU counties have a historically unique opportunity to enable their creative industries to promote the knowledge societies, applying new business models to their media content and networks markets, that are digital dividend (DD) aware. This new extra-media gatekeeping factor could shape new alliances and co operations among the member states and the global media markets, as well.

[Effects of biochar application on greenhouse gas emission from paddy soil and its physical and chemical properties].

PubMed

Liu, Yu-xue; Wang, Yao-feng; Lü, Hao-hao; Chen, Yi; Tang, Xu; Wu, Chun-yan; Zhong, Zhe-ke; Yang, Sheng-mao

2013-08-01

A field experiment was conducted to investigate the effects of rice straw returning and rice straw biochar and life rubbish biochar application on the greenhouse gas (CH4, CO2 and N2O) emission from paddy soil, its physical and chemical properties, and rice grain yield. Compared with rice straw returning, applying rice straw biochar decreased the cumulative CH4 and N2O emissions from paddy soil significantly by 64.2% - 78.5% and 16.3% - 18.4%, respectively. Whether planting rice or not, the cumulative N2O emission from paddy soil under the applications of rice straw biochar and life rubbish biochar was decreased significantly, compared with that without biochar amendment. Under the condition of no rice planting, applying life rubbish biochar reduced the cumulative CO2 emission significantly by 25.3%. Rice straw biochar was superior to life rubbish biochar in improving soil pH and available potassium content. Both rice straw biochar and life rubbish biochar could increase the soil organic carbon content significantly, but had less effects on the soil bulk density, total nitrogen and available phosphorus contents, cation exchange capacity (CEC), and grain yield. It was suggested that compared with rice straw returning, straw biochar was more effective in improving rice grain yield.

Using a peanut drying monitoring system to estimate costs of nonbeneficial dryer operation

USDA-ARS?s Scientific Manuscript database

Presently, the peanut industry lacks a commercially available, industry-accepted solution for real-time kernel moisture content determination during peanut drying. Samples of unshelled peanuts are extracted from the semitrailer by an operator periodically, and the samples have to be cleaned and shel...

Syngas production by high temperature steam/CO2 coelectrolysis using solid oxide electrolysis cells.

PubMed

Chen, Xinbing; Guan, Chengzhi; Xiao, Guoping; Du, Xianlong; Wang, Jian-Qiang

2015-01-01

High temperature (HT) steam/CO2 coelectrolysis with solid oxide electrolysis cells (SOECs) using the electricity and heat generated from clean energies is an important alternative for syngas production without fossil fuel consumption and greenhouse gas emissions. Herein, reaction characteristics and the outlet syngas composition of HT steam/CO2 coelectrolysis under different operating conditions, including distinct inlet gas compositions and electrolysis current densities, are systematically studied at 800 °C using commercially available SOECs. The HT coelectrolysis process, which has comparable performance to HT steam electrolysis, is more active than the HT CO2 electrolysis process, indicating the important contribution of the reverse water-gas shift reaction in the formation of CO. The outlet syngas composition from HT steam/CO2 coelectrolysis is very sensitive to the operating conditions, indicating the feasibility of controlling the syngas composition by varying these conditions. Maximum steam and CO2 utilizations of 77% and 76% are achieved at 1.0 A cm(-2) with an inlet gas composition of 20% H2/40% steam/40% CO2.

Optimization of the structural characteristics of CaO and its effective stabilization yield high-capacity CO2 sorbents.

PubMed

Naeem, Muhammad Awais; Armutlulu, Andac; Imtiaz, Qasim; Donat, Felix; Schäublin, Robin; Kierzkowska, Agnieszka; Müller, Christoph R

2018-06-19

Calcium looping, a CO 2 capture technique, may offer a mid-term if not near-term solution to mitigate climate change, triggered by the yet increasing anthropogenic CO 2 emissions. A key requirement for the economic operation of calcium looping is the availability of highly effective CaO-based CO 2 sorbents. Here we report a facile synthesis route that yields hollow, MgO-stabilized, CaO microspheres featuring highly porous multishelled morphologies. As a thermal stabilizer, MgO minimized the sintering-induced decay of the sorbents' CO 2 capacity and ensured a stable CO 2 uptake over multiple operation cycles. Detailed electron microscopy-based analyses confirm a compositional homogeneity which is identified, together with the characteristics of its porous structure, as an essential feature to yield a high-performance sorbent. After 30 cycles of repeated CO 2 capture and sorbent regeneration, the best performing material requires as little as 11 wt.% MgO for structural stabilization and exceeds the CO 2 uptake of the limestone-derived reference material by ~500%.

Knowledge, beliefs and attitudes of squash venue operators relating to use of protective eyewear.

PubMed

Eime, Rochelle; Finch, Caroline; Owen, Neville; Gifford, Sandra; Vear, Paul

2004-03-01

Sports venues are in a position to potentially influence the safety practices of their patrons. This study examined the knowledge, beliefs and attitudes of venue operators that could influence the use of protective eyewear by squash players. A 50% random sample of all private and public squash venues affiliated with the Victorian Squash Federation in metropolitan Melbourne was selected. Face-to-face interviews were conducted with 15 squash venue operators during August 2001. Interviews were transcribed and content and thematic analyses were performed. The content of the interviews covered five topics: (1) overall injury risk perception, (2) eye injury occurrence, (3) knowledge, behaviors, attitudes and beliefs associated with protective eyewear, (4) compulsory protective eyewear and (5) availability of protective eyewear at venues. Venue operators were mainly concerned with the severe nature of eye injuries, rather than the relatively low incidence of these injuries. Some venue operators believed that players should wear any eyewear, rather than none at all, and believed that more players should use protective eyewear. Generally, they did not believe that players with higher levels of experience and expertise needed to wear protective eyewear when playing. Only six venues had at least one type of eyewear available for players to hire or borrow or to purchase. Operators expressed a desire to be informed about correct protective eyewear. Appropriate protective eyewear is not readily available at squash venues. Better-informed venue operators may be more likely to provide suitable protective eyewear.

Effects of Co contents on the microstructures and properties of the electrodeposited NiCo–Zr composite coatings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, Fei; Jiang, Chuanhai, E-mail: chuanhaijiang1963@163.com; Zhao, Yuantao

2015-05-15

Highlights: • The novel NiCo–Zr coatings were prepared by electro-deposition. • Surface morphology, crystal structure, grain size and microstrain were examined. • Texture, residual stress and corrosion resistance were investigated. • Addition of Co increased the hardness and corrosion resistance of the coatings. - Abstract: In this study, the NiCo–Zr composite coatings were prepared from the electrolytes with different Co{sup 2+} concentrations by electrodeposition method. The effects of Co contents on the crystal structure, surface morphology, grain size, microstrain and residual stress were examined by X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX) andmore » atomic force microscope (AFM). The corrosion resistance of the composite coatings was also examined by the potentiodynamic polarization and electrochemical impedance (EIS) measurements. The results revealed that the crystal structures of the coatings were dependent on the Co contents and addition of Co content of 58 wt% resulted in the formation of hexagonal (hcp) Co. The increasing Co contents in the NiCo–Zr composite coatings resulted in the smoother and more compact surface, decreased the grain size and increased the microstrain. The micro-hardness and residual stress also increased with increasing Co contents. The addition of Co increased the corrosion resistance of the NiCo–Zr composite coatings compared with the Ni–Zr coating while the corrosion resistance of the NiCo–Zr composite coatings decreased as the Co contents increased.« less

Can CO2 Turbulent Flux Be Measured by Lidar? A Preliminary Study

NASA Technical Reports Server (NTRS)

Gilbert, Fabien; Koch, Grady; Beyon, Jeffrey Y.; Hilton, Timothy W.; Davis, Kenneth J.; Andrews, Arlyn; Flamant, Pierre H.; Singh, Upendra N.

2011-01-01

The vertical profiling ofCO2 turbulent fluxes in the atmospheric boundary layer (ABL) is investigated using a coherent differential absorption lidar (CDIAL) operated nearby a tall tower in Wisconsin during June 2007. A CDIAL can perform simultaneous range-resolved CO2 DIAL and velocity measurements. The lidar eddy covariance technique is presented. The aims of the study are (i) an assessment of performance and current limitation of available CDIAL for CO2 turbulent fluxes and (ii) the derivation of instrument specifications to build a future CDIAL to perform accurate range-resolved CO2 fluxes. Experimental lidar CO2 mixing ratio and vertical velocity profiles are successfully compared with in situ sensors measurements. Time and space integral scales of turbulence in the ABL are addressed that result in limitation for time averaging and range accumulation. A first attempt to infer CO2 fluxes using an eddy covariance technique with currently available 2-mm CDIAL dataset is reported.

Effects of compost fertilization in organic farming on micronutrients and heavy metals in soil and crops

NASA Astrophysics Data System (ADS)

Erhart, Eva; Sager, Manfred; Bonell, Marion; Fuchs, Katrin; Haas, Dieter; Ableidinger, Christoph; Hartl, Wilfried

2015-04-01

For organic stockless and vegetable farms using biowaste compost is a way to sustain soil humus content. At the same time compost use in agriculture closes local nutrient cycles. Besides organic matter and main nutrients, biowaste compost also imports micronutrients and heavy metals in amounts determined by the compost input material. The aim of this work was to assess total and plant-available contents of micronutrients B, Ca, Cu, Fe, Mn, Mo, Ni, Zn, beneficial elements Co and Se and heavy metals Cd, Cr and Pb in the soil and in crops after 20 years of fertilization with compost produced from source-separated organic waste. Topsoil and wheat grain samples were collected from the long-term field experiment 'STIKO' situated near Vienna on a Molli-gleyic Fluvisol. Between 1992 and 2012 the organic treatments C1, C2 and C3 had received 5, 10 and 14 t ha-1 yr-1 (wet wt.) biowaste compost on average. They were compared with the unfertilized organic control treatment and with three mineral fertilization treatments, which had received 20, 32 and 44 kg N ha-1 yr 1, respectively, plus 40 kg P and 68 kg K ha-1 yr-1 on average. Total soil element contents of B, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se and Zn were measured in aqua regia digestion. Immediately water-soluble elements were analysed in soil saturation extract, elements in exchangeable form in LiCl extract following Husz (2001), and long-term available elements in 0.5 N HCl extract. Wheat grains were dehulled, milled and subjected to microwave digestion with HNO3 and H2O2. Wheat was analyzed for Cd and Pb with ICP-MS. All other elements in wheat and all soil extracts were analyzed using ICP-AES. Total soil concentrations of micronutrients, heavy metals and beneficial elements were in the range of usual soil contents and lower than the Austrian background values for arable land with comparable pH and carbonate concentration (Schwarz and Freudenschuss, 2004) in all treatments (all mg kg-1: B 14-19, Fe 16000-18000, Mn 397-445, Mo 0.7-1.0, Cu 15-17, Ni 21-22, Zn 45-52, Cr 26-28, Pb 13-17, Co 7.5-8.4). Total soil concentrations of Cd (0.37-0.46 mg kg-1) were the same as the background values. No significant differences were found between the treatments and the unfertilized control. Similarly, the plant available LiCl-fraction and the long-term available HCl-fraction did not show significant differences between the treatments. In the soil saturation extracts, Cu content was 18-22 µg kg-1, B 172-187 µg kg-1, Fe 62-113 µg kg-1 and Ca 62-71 mg kg-1, all in the usual range of soil saturation extracts of agricultural fields without significant differences between treatments. The other elements were below the limit of determination. In the wheat, contents of micronutrients, heavy metals and beneficial elements were in the same range as in other Austrian wheat samples (Spiegel and Sager, 2008) with the exception of Ca. Element contents were (all in mg kg-1): B 0.5-0.6, Ca 387-464, Cd 0.023-0.028, Co 0.006, Cr 0.10-0.17, Cu 4.7-5.3, Fe 36-50, Mn 30-33, Mo 0.31-0.35, Ni 0.11-0.15, Se 0.15-0.27 and Zn 28-31. Pb was below the limit of determination in the wheat grains. No significant differences were detected between the treatments. After 20 years of compost fertilization with high quality biowaste compost at the above rates no increase in micronutrients and heavy metals was detected in total soil contents and in plant-available fractions nor in wheat grains.

Securing co-operation from persons supplying statistical data

PubMed Central

Aubenque, M. J.; Blaikley, R. M.; Harris, F. Fraser; Lal, R. B.; Neurdenburg, M. G.; Hernández, R. de Shelly

1954-01-01

Securing the co-operation of persons supplying information required for medical statistics is essentially a problem in human relations, and an understanding of the motivations, attitudes, and behaviour of the respondents is necessary. Before any new statistical survey is undertaken, it is suggested by Aubenque and Harris that a preliminary review be made so that the maximum use is made of existing information. Care should also be taken not to burden respondents with an overloaded questionnaire. Aubenque and Harris recommend simplified reporting. Complete population coverage is not necessary. Neurdenburg suggests that the co-operation and support of such organizations as medical associations and social security boards are important and that propaganda should be directed specifically to the groups whose co-operation is sought. Informal personal contacts are valuable and desirable, according to Blaikley, but may have adverse effects if the right kind of approach is not made. Financial payments as an incentive in securing co-operation are opposed by Neurdenburg, who proposes that only postage-free envelopes or similar small favours be granted. Blaikley and Harris, on the other hand, express the view that financial incentives may do much to gain the support of those required to furnish data; there are, however, other incentives, and full use should be made of the natural inclinations of respondents. Compulsion may be necessary in certain instances, but administrative rather than statutory measures should be adopted. Penalties, according to Aubenque, should be inflicted only when justified by imperative health requirements. The results of surveys should be made available as soon as possible to those who co-operated, and Aubenque and Harris point out that they should also be of practical value to the suppliers of the information. Greater co-operation can be secured from medical persons who have an understanding of the statistical principles involved; Aubenque and Neurdenburg suggest that a course in elementary statistical methodology be introduced in the curriculum of medical schools. Methods for improving co-operation, and thus the compilation of statistics, in particular countries are discussed by Lal and de Shelly Hernández, who deal with India and Venezuela respectively. PMID:13199667

The extent of arsenic and of metal uptake by aboveground tissues of Pteris vittata and Cyperus involucratus growing in copper- and cobalt-rich tailings of the Zambian copperbelt.

PubMed

Kříbek, Bohdan; Mihaljevič, Martin; Sracek, Ondra; Knésl, Ilja; Ettler, Vojtěch; Nyambe, Imasiku

2011-08-01

The extent of arsenic (As) and metal accumulation in fronds of the As hyperaccumulator Pteris vittata (Chinese brake fern) and in leaves of Cyperus involucratus, which grow on the surface of an old flotation tailings pond in the Zambian Copperbelt province, was studied. The tailings consist of two types of material with distinct chemical composition: (1) reddish-brown tailings rich in As, iron (Fe), and other metals, and (2) grey-green tailings with a lower content of As, Fe, and other metals, apart from manganese (Mn). P. vittata accumulates from 2350 to 5018 μg g(-1) As (total dry weight [dw]) in its fronds regardless of different total and plant-available As concentrations in both types of tailings. Concentrations of As in C. involucratus leaves are much lower (0.24-30.3 μg g(-1) dw). Contents of copper (Cu) and cobalt (Co) in fronds of P. vittata (151-237 and 18-38 μg g(-1) dw, respectively) and in leaves of C. involucratus (96-151 and 9-14 μg g(-1) dw, respectively) are high, whereas concentrations of other metals (Fe, Mn, and zinc [Zn]) are low and comparable with contents of the given metals in common plants. Despite great differences in metal concentrations in the two types of deposited materials, concentrations of most metals in plant tissues are very similar. This indicates an exclusion or avoidance mechanism operating when concentrations of the metals in substrate are particularly high. The results of the investigation show that Chinese brake fern is not only a hyperaccumulator of As but has adapted itself to high concentrations of Cu and Co in flotation tailings of the Zambian Copperbelt.

Operation of a 25 KWth Calcium Looping Pilot-plant with High Oxygen Concentrations in the Calciner.

PubMed

Erans, María; Jeremias, Michal; Manovic, Vasilije; Anthony, Edward J

2017-10-25

Calcium looping (CaL) is a post-combustion CO2 capture technology that is suitable for retrofitting existing power plants. The CaL process uses limestone as a cheap and readily available CO2 sorbent. While the technology has been widely studied, there are a few available options that could be applied to make it more economically viable. One of these is to increase the oxygen concentration in the calciner to reduce or eliminate the amount of recycled gas (CO2, H2O and impurities); therefore, decreasing or removing the energy necessary to heat the recycled gas stream. Moreover, there is a resulting increase in the energy input due to the change in the combustion intensity; this energy is used to enable the endothermic calcination reaction to occur in the absence of recycled flue gases. This paper presents the operation and first results of a CaL pilot plant with 100% oxygen combustion of natural gas in the calciner. The gas coming into the carbonator was a simulated flue gas from a coal-fired power plant or cement industry. Several limestone particle size distributions are also tested to further explore the effect of this parameter on the overall performance of this operating mode. The configuration of the reactor system, the operating procedures, and the results are described in detail in this paper. The reactor showed good hydrodynamic stability and stable CO2 capture, with capture efficiencies of up to 70% with a gas mixture simulating the flue gas of a coal-fired power plant.

Allocation of Nitrogen and Carbon Is Regulated by Nodulation and Mycorrhizal Networks in Soybean/Maize Intercropping System

PubMed Central

Wang, Guihua; Sheng, Lichao; Zhao, Dan; Sheng, Jiandong; Wang, Xiurong; Liao, Hong

2016-01-01

Soybean/maize intercropping has remarkable advantages in increasing crop yield and nitrogen (N) efficiency. However, little is known about the contributions of rhizobia or arbuscular mycorrhizal fungi (AMF) to yield increases and N acquisition in the intercropping system. Plus, the mechanisms controlling carbon (C) and N allocation in intercropping systems remain unsettled. In the present study, a greenhouse experiment combined with 15N and 13C labeling was conducted using various inoculation and nutrient treatments. The results showed that co-inoculation with AMF and rhizobia dramatically increased biomass and N content of soybean and maize, and moderate application of N and phosphorus largely amplified the effect of co-inoculation. Maize had a competitive advantage over soybean only under co-inoculation and moderate nutrient availability conditions, indicating that the effects of AMF and rhizobia in intercropping systems are closely related to nutrient status. Results from 15N labeling showed that the amount of N transferred from soybean to maize in co-inoculations was 54% higher than that with AMF inoculation alone, with this increased N transfer partly resulting from symbiotic N fixation. The results from 13C labeling showed that 13C content increased in maize shoots and decreased in soybean roots with AMF inoculation compared to uninoculated controls. Yet, with co-inoculation, 13C content increased in soybean. These results indicate that photosynthate assimilation is stimulated by AM symbiosis in maize and rhizobial symbiosis in soybean, but AMF inoculation leads to soybean investing more carbon than maize into common mycorrhizal networks (CMNs). Overall, the results herein demonstrate that the growth advantage of maize when intercropped with soybean is due to acquisition of N by maize via CMNs while this crop contributes less C into CMNs than soybean under co-inoculation conditions. PMID:28018420

Allocation of Nitrogen and Carbon Is Regulated by Nodulation and Mycorrhizal Networks in Soybean/Maize Intercropping System.

PubMed

Wang, Guihua; Sheng, Lichao; Zhao, Dan; Sheng, Jiandong; Wang, Xiurong; Liao, Hong

2016-01-01

Soybean/maize intercropping has remarkable advantages in increasing crop yield and nitrogen (N) efficiency. However, little is known about the contributions of rhizobia or arbuscular mycorrhizal fungi (AMF) to yield increases and N acquisition in the intercropping system. Plus, the mechanisms controlling carbon (C) and N allocation in intercropping systems remain unsettled. In the present study, a greenhouse experiment combined with 15 N and 13 C labeling was conducted using various inoculation and nutrient treatments. The results showed that co-inoculation with AMF and rhizobia dramatically increased biomass and N content of soybean and maize, and moderate application of N and phosphorus largely amplified the effect of co-inoculation. Maize had a competitive advantage over soybean only under co-inoculation and moderate nutrient availability conditions, indicating that the effects of AMF and rhizobia in intercropping systems are closely related to nutrient status. Results from 15 N labeling showed that the amount of N transferred from soybean to maize in co-inoculations was 54% higher than that with AMF inoculation alone, with this increased N transfer partly resulting from symbiotic N fixation. The results from 13 C labeling showed that 13 C content increased in maize shoots and decreased in soybean roots with AMF inoculation compared to uninoculated controls. Yet, with co-inoculation, 13 C content increased in soybean. These results indicate that photosynthate assimilation is stimulated by AM symbiosis in maize and rhizobial symbiosis in soybean, but AMF inoculation leads to soybean investing more carbon than maize into common mycorrhizal networks (CMNs). Overall, the results herein demonstrate that the growth advantage of maize when intercropped with soybean is due to acquisition of N by maize via CMNs while this crop contributes less C into CMNs than soybean under co-inoculation conditions.

Chado controller: advanced annotation management with a community annotation system.

PubMed

Guignon, Valentin; Droc, Gaëtan; Alaux, Michael; Baurens, Franc-Christophe; Garsmeur, Olivier; Poiron, Claire; Carver, Tim; Rouard, Mathieu; Bocs, Stéphanie

2012-04-01

We developed a controller that is compliant with the Chado database schema, GBrowse and genome annotation-editing tools such as Artemis and Apollo. It enables the management of public and private data, monitors manual annotation (with controlled vocabularies, structural and functional annotation controls) and stores versions of annotation for all modified features. The Chado controller uses PostgreSQL and Perl. The Chado Controller package is available for download at http://www.gnpannot.org/content/chado-controller and runs on any Unix-like operating system, and documentation is available at http://www.gnpannot.org/content/chado-controller-doc The system can be tested using the GNPAnnot Sandbox at http://www.gnpannot.org/content/gnpannot-sandbox-form valentin.guignon@cirad.fr; stephanie.sidibe-bocs@cirad.fr Supplementary data are available at Bioinformatics online.

47 CFR 74.602 - Frequency assignment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... segments 17,700-18,580 and 19,260-19,700 MHz are available for broadcast auxiliary stations as described in... television translator relay stations. Stations operating on frequencies in the sub-bands 18.3-18.58 GHz and... 18, 1998 may continue those operations on a shared co-primary basis with other services under parts...

47 CFR 74.602 - Frequency assignment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... segments 17,700-18,580 and 19,260-19,700 MHz are available for broadcast auxiliary stations as described in... television translator relay stations. Stations operating on frequencies in the sub-bands 18.3-18.58 GHz and... 18, 1998 may continue those operations on a shared co-primary basis with other services under parts...

Concepts and data model for a co-operative neurovascular database.

PubMed

Mansmann, U; Taylor, W; Porter, P; Bernarding, J; Jäger, H R; Lasjaunias, P; Terbrugge, K; Meisel, J

2001-08-01

Problems of clinical management of neurovascular diseases are very complex. This is caused by the chronic character of the diseases, a long history of symptoms and diverse treatments. If patients are to benefit from treatment, then treatment decisions have to rely on reliable and accurate knowledge of the natural history of the disease and the various treatments. Recent developments in statistical methodology and experience from electronic patient records are used to establish an information infrastructure based on a centralized register. A protocol to collect data on neurovascular diseases with technical as well as logistical aspects of implementing a database for neurovascular diseases are described. The database is designed as a co-operative tool of audit and research available to co-operating centres. When a database is linked to a systematic patient follow-up, it can be used to study prognosis. Careful analysis of patient outcome is valuable for decision-making.

Transiting exoplanets from the CoRoT space mission. XI. CoRoT-8b: a hot and dense sub-Saturn around a K1 dwarf

NASA Astrophysics Data System (ADS)

Bordé, P.; Bouchy, F.; Deleuil, M.; Cabrera, J.; Jorda, L.; Lovis, C.; Csizmadia, S.; Aigrain, S.; Almenara, J. M.; Alonso, R.; Auvergne, M.; Baglin, A.; Barge, P.; Benz, W.; Bonomo, A. S.; Bruntt, H.; Carone, L.; Carpano, S.; Deeg, H.; Dvorak, R.; Erikson, A.; Ferraz-Mello, S.; Fridlund, M.; Gandolfi, D.; Gazzano, J.-C.; Gillon, M.; Guenther, E.; Guillot, T.; Guterman, P.; Hatzes, A.; Havel, M.; Hébrard, G.; Lammer, H.; Léger, A.; Mayor, M.; Mazeh, T.; Moutou, C.; Pätzold, M.; Pepe, F.; Ollivier, M.; Queloz, D.; Rauer, H.; Rouan, D.; Samuel, B.; Santerne, A.; Schneider, J.; Tingley, B.; Udry, S.; Weingrill, J.; Wuchterl, G.

2010-09-01

Aims: We report the discovery of CoRoT-8b, a dense small Saturn-class exoplanet that orbits a K1 dwarf in 6.2 days, and we derive its orbital parameters, mass, and radius. Methods: We analyzed two complementary data sets: the photometric transit curve of CoRoT-8b as measured by CoRoT and the radial velocity curve of CoRoT-8 as measured by the HARPS spectrometer. Results: We find that CoRoT-8b is on a circular orbit with a semi-major axis of 0.063 ± 0.001 AU. It has a radius of 0.57 ± 0.02 RJ, a mass of 0.22 ± 0.03 MJ, and therefore a mean density of 1.6 ± 0.1 g cm-3. Conclusions: With 67% of the size of Saturn and 72% of its mass, CoRoT-8b has a density comparable to that of Neptune (1.76 g cm-3). We estimate its content in heavy elements to be 47-63 {M}_⊕, and the mass of its hydrogen-helium envelope to be 7-23 {M}_⊕. At 0.063 AU, the thermal loss of hydrogen of CoRoT-8b should be no more than 0.1% over an assumed integrated lifetime of 3 Ga. Observations made with SOPHIE spectrograph at Observatoire de Haute Provence, France (PNP.07B.MOUT), and the HARPS spectrograph at ESO La Silla Observatory (081.C-0388 and 083.C-0186). The CoRoT space mission, launched on December 27, 2006, has been developed and is operated by the CNES with the contribution of Austria, Belgium, Brasil, ESA, Germany, and Spain.Both data sets are available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/520/A66

[Effects of interaction between vermicompost and probiotics on soil nronerty, yield and quality of tomato].

PubMed

Shen, Fei; Zhu, Tong-bin; Teng, Ming-jiao; Chen, Yue; Liu, Man-qiang; Hu, Feng; Li, Hui-xin

2016-02-01

In this study, we investigated the effects of two strains of probiotic bacteria (Bacillus megaterium BM and Bacillus amyloliquefaciens BA) combined with chemical fertilizers and vermicompost on the soil property, the yield and quality of tomato. The results showed that under the same nutrient level, vermicompost significantly increased the yield, soluble sugar and protein contents of fruit, the soil pH and available phosphorus when compared with chemical fertilizers. Vermicompost combined with probiotics not only increased the tomato yield, soluble sugar, protein and vitamin C contents, sugar/acid ratio of fruit, and reduced the organic acid and nitrate nitrogen contents of fruit, also increased the soil pH and nitrate nitrogen content, and reduced soil electric conductivity when compared with vermicompost treatment. This improved efficiency was better than that by chemical fertilizers combined with probiotics. For BA and BM applied with chemical fertilizers or vermicompost, both stains had no significant effect on tomato quality. When co-applied with vermicompost, BA and BM showed significant difference in tomato yield. High soil available phosphorus content was determined when BM was combined with chemical fertilizers, while high soil available potassium content was obtained when BA was combined with vermicompost. Our results suggested that probiotics and vermicompost could be used as alternatives of chemical fertilizers in tomato production and soil fertility improvement.

Implementing Distributed Operations: A Comparison of Two Deep Space Missions

NASA Technical Reports Server (NTRS)

Mishkin, Andrew; Larsen, Barbara

2006-01-01

Two very different deep space exploration missions--Mars Exploration Rover and Cassini--have made use of distributed operations for their science teams. In the case of MER, the distributed operations capability was implemented only after the prime mission was completed, as the rovers continued to operate well in excess of their expected mission lifetimes; Cassini, designed for a mission of more than ten years, had planned for distributed operations from its inception. The rapid command turnaround timeline of MER, as well as many of the operations features implemented to support it, have proven to be conducive to distributed operations. These features include: a single science team leader during the tactical operations timeline, highly integrated science and engineering teams, processes and file structures designed to permit multiple team members to work in parallel to deliver sequencing products, web-based spacecraft status and planning reports for team-wide access, and near-elimination of paper products from the operations process. Additionally, MER has benefited from the initial co-location of its entire operations team, and from having a single Principal Investigator, while Cassini operations have had to reconcile multiple science teams distributed from before launch. Cassini has faced greater challenges in implementing effective distributed operations. Because extensive early planning is required to capture science opportunities on its tour and because sequence development takes significantly longer than sequence execution, multiple teams are contributing to multiple sequences concurrently. The complexity of integrating inputs from multiple teams is exacerbated by spacecraft operability issues and resource contention among the teams, each of which has their own Principal Investigator. Finally, much of the technology that MER has exploited to facilitate distributed operations was not available when the Cassini ground system was designed, although later adoption of web-based and telecommunication tools has been critical to the success of Cassini operations.

Quantitative co-occurrence of sesquiterpenes; a tool for elucidating their biosynthesis in Indian sandalwood, Santalum album.

PubMed

Jones, Christopher G; Ghisalberti, Emilio L; Plummer, Julie A; Barbour, Elizabeth L

2006-11-01

A chemotaxonomic approach was used to investigate biosynthetic relationships between heartwood sesquiterpenes in Indian sandalwood, Santalum album L. Strong, linear relationships exist between four structural classes of sesquiterpenes; alpha- and beta-santalenes and bergamotene; gamma- and beta-curcumene; beta-bisabolene and alpha-bisabolol and four unidentified sesquiterpenes. All samples within the heartwood yielded the same co-occurrence patterns, however wood from young trees tended to be more variable. It is proposed that the biosynthesis of each structural class of sesquiterpene in sandalwood oil is linked through common carbocation intermediates. Lack of co-occurrence between each structural class suggests that four separate cyclase enzymes may be operative. The biosynthesis of sandalwood oil sesquiterpenes is discussed with respect to these co-occurrence patterns. Extractable oil yield was correlated to heartwood content of each wood core and the oil composition did not vary significantly throughout the tree.

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

PubMed

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.

Low temperature circulating fluidized bed gasification and co-gasification of municipal sewage sludge. Part 2: Evaluation of ash materials as phosphorus fertilizer.

PubMed

Thomsen, Tobias Pape; Hauggaard-Nielsen, Henrik; Gøbel, Benny; Stoholm, Peder; Ahrenfeldt, Jesper; Henriksen, Ulrik B; Müller-Stöver, Dorette Sophie

2017-08-01

The study is part 2 of 2 in an investigation of gasification and co-gasification of municipal sewage sludge in low temperature gasifiers. In this work, solid residuals from thermal gasification and co-gasification of municipal sewage sludge were investigated for their potential use as fertilizer. Ashes from five different low temperature circulating fluidized bed (LT-CFB) gasification campaigns including two mono-sludge campaigns, two sludge/straw mixed fuels campaigns and a straw reference campaign were compared. Experiments were conducted on two different LT-CFBs with thermal capacities of 100kW and 6MW, respectively. The assessment included: (i) Elemental composition and recovery of key elements and heavy metals; (ii) content of total carbon (C) and total nitrogen (N); (iii) pH; (iv) water extractability of phosphorus after incubation in soil; and (v) plant phosphorus response measured in a pot experiment with the most promising ash material. Co-gasification of straw and sludge in LT-CFB gasifiers produced ashes with a high content of recalcitrant C, phosphorus (P) and potassium (K), a low content of heavy metals (especially cadmium) and an improved plant P availability compared to the mono-sludge ashes, thereby showing the best fertilizer qualities among all assessed materials. It was also found that bottom ashes from the char reactor contained even less heavy metals than cyclone ashes. It is concluded that LT-CFB gasification and co-gasification is a highly effective way to purify and sanitize sewage sludge for subsequent use in agricultural systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of Co-doping on the humidity sensing properties of ordered mesoporous TiO2

NASA Astrophysics Data System (ADS)

Li, Zhong; Haidry, Azhar Ali; Gao, Bin; Wang, Tao; Yao, ZhengJun

2017-08-01

Monitoring of humidity is of utmost importance as it is essential part of almost every process in our life. Many commercial humidity sensors based on metal oxide semiconductors are available in the market, but there is still need to synthesize low-cost, fast and highly sensitive humidity sensors with no interference from background environment. The aim of this work was to fabricate the ordered mesoporous un-doped and Co-doped TiO2 (0.1-5 mol% Co) and to analyze its humidity sensing properties at room temperatures. The ordered mesoporous powders with high specific surface area (SSA) were prepared by multicomponent self-assembly procedure and then spray-coated onto the sensor substrates with interdigitated gold electrodes. The sensors exhibited excellent stability and reproducible resistance change under various relative humidity percentages (9-90% RH) with negligible effect of background environment. For instance, the response to 90% RH at room temperature was about five orders of magnitude (∼1.39 × 105) and the response time (Tres) was ∼24 s. The reaction/recovery times of the sensors were compared with commercial humidity sensor to show that the reaction times in this work are not given by the surface reaction of water vapor on the sensor surfaces, rather these are mainly influenced by the experimental setup. The sensor response increased up to 3 mol% Co-contents and then decreased for 5 mol% Co-contents. Based on the experimental results, the surface reaction of humidity is discussed related to specific surface area, average grain size and cobalt contents to understand the humidity sensing mechanism.

Ultrasound-assisted extraction and quantitation of oils from Syzygium aromaticum flower bud (clove) with supercritical carbon dioxide.

PubMed

Yang, Yu-Chiao; Wei, Ming-Chi; Hong, Show-Jen

2014-01-03

This study evaluated ultrasound-assisted supercritical carbon dioxide (USC-CO2) extraction for determining the extraction yields of oils and the contents of eugenol, β-caryophyllene, eugenyl acetate and α-humulene from clove buds. Compared to traditional SC-CO2 extraction, USC-CO2 extraction might provide a 13.5% increase in the extraction yield for the oil while utilizing less severe operating parameters, such as temperature, pressure, CO2 flow rate and the time consumed by the process. Our results were comparable to those obtained using the heat reflux extraction method, though the yield was improved by 20.8% using USC-CO2. In kinetic studies, the USC-CO2 extraction of clove oil followed second-order kinetics. The activation energy for the oil extraction was 76.56kJ/mol. The USC-CO2 procedure facilitated the use of mild extraction conditions, improved extraction efficiency and the quality of products and is a potential method for industry. Copyright © 2013 Elsevier B.V. All rights reserved.

Encapsulated monoclinic sulfur for stable cycling of li-s rechargeable batteries.

PubMed

Moon, San; Jung, Young Hwa; Jung, Wook Ki; Jung, Dae Soo; Choi, Jang Wook; Kim, Do Kyung

2013-12-03

Monoclinic S8 , an uncommon allotrope of sulfur at room temperature, can be formed when common orthorhombic S8 is heat-treated under enclosed environments in nanometer dimensions. Monoclinic S8 prevents the formation of soluble polysulfides during battery operation, resulting in unprecedented cycling performance over 1000 cycles under the highest sulfur content to date. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using the eXtensible Markup Language (XML) in a regional electronic patient record for patients with malignant diseases.

PubMed

Wolff, A C; Mludek, V; van der Haak, M; Bork, W; Bülzebruck, H; Drings, P; Schmücker, P; Wannenmacher, M; Haux, R

2001-01-01

Communication between different institutions which are responsible for the treatment of the same patient is of outstanding significance, especially in the field of tumor diseases. Regional electronic patient records could support the co-operation of different institutions by providing ac-cess to all necessary information whether it belongs to the own institution or to a partner. The Department of Medical Informatics, University of Heidelberg is performing a project in co-operation with the Thoraxclinic-Heidelberg and the Department of Clinical Radiology, University of Heidelberg with the goal: to define an architectural concept for interlinking the electronic patient record of the two clinical institutions to build a common virtual electronic patient record and carry out an exemplary implementation, to examine composition, structure and content of medical documents for tumor patients with the aim of defining an XML-based markup language allowing summarizing overviews and suitable granularities, and to integrate clinical practice guidelines and other external knowledge with the electronic patient record using XML-technologies to support the physician in the daily decision process. This paper will show, how a regional electronic patient record could be built on an architectural level and describe elementary steps towards a on content-oriented structuring of medical records.

Ultrasonic pretreatment effects on the co-pyrolysis of municipal solid waste and paper sludge through orthogonal test.

PubMed

Fang, Shiwen; Gu, Wenlu; Chen, Lin; Yu, Zhaosheng; Dai, Minquan; Lin, Yan; Liao, Yanfen; Ma, Xiaoqian

2018-06-01

In this study, the influences of ultrasonic pretreatment factors (frequency, power, treatment time) on blends of municipal solid waste (MSW) and paper sludge (PS) with additive (MgO) was explored, through orthogonal experiments design. The optimum operating condition wanted to be acquired. However, for the ultimate (H/C) and ash analysis after pretreatment, solid residue mass and oxygenates compounds contents in products, the influences of factors were in different results. With adding PS unceasingly, the contents of hydrocarbon compounds decreased. And the ultrasonic pretreatment had the obvious influence with high PS percentage. Longer treatment time resulted to the lower content of oxygenates compounds. After adding MgO, the residue mass reduced, which meant MgO had the catalytic action, and the oxygenates compounds content reduced only with 100 kHz, which had the sonochemical effect. Copyright © 2018 Elsevier Ltd. All rights reserved.

CO 2 capture from IGCC gas streams using the AC-ABC process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagar, Anoop; McLaughlin, Elisabeth; Hornbostel, Marc

The objective of this project was to develop a novel, low-cost CO 2 capture process from pre-combustion gas streams. The bench-scale work was conducted at the SRI International. A 0.15-MWe integrated pilot plant was constructed and operated for over 700 hours at the National Carbon Capture Center, Wilsonville, AL. The AC-ABC (ammonium carbonate-ammonium bicarbonate) process for capture of CO 2 and H 2S from the pre-combustion gas stream offers many advantages over Selexol-based technology. The process relies on the simple chemistry of the NH 3-CO 2-H 2O-H 2S system and on the ability of the aqueous ammoniated solution to absorbmore » CO 2 at near ambient temperatures and to release it as a high-purity, high-pressure gas at a moderately elevated regeneration temperature. It is estimated the increase in cost of electricity (COE) with the AC-ABC process will be ~ 30%, and the cost of CO 2 captured is projected to be less than $27/metric ton of CO 2 while meeting 90% CO 2 capture goal. The Bechtel Pressure Swing Claus (BPSC) is a complementary technology offered by Bechtel Hydrocarbon Technology Solutions, Inc. BPSC is a high-pressure, sub-dew-point Claus process that allows for nearly complete removal of H 2S from a gas stream. It operates at gasifier pressures and moderate temperatures and does not affect CO 2 content. When coupled with AC-ABC, the combined technologies allow a nearly pure CO 2 stream to be captured at high pressure, something which Selexol and other solvent-based technologies cannot achieve.« less

Highly efficient visible light photocatalytic reduction of CO2 to hydrocarbon fuels by Cu-nanoparticle decorated graphene oxide.

PubMed

Shown, Indrajit; Hsu, Hsin-Cheng; Chang, Yu-Chung; Lin, Chang-Hui; Roy, Pradip Kumar; Ganguly, Abhijit; Wang, Chen-Hao; Chang, Jan-Kai; Wu, Chih-I; Chen, Li-Chyong; Chen, Kuei-Hsien

2014-11-12

The production of renewable solar fuel through CO2 photoreduction, namely artificial photosynthesis, has gained tremendous attention in recent times due to the limited availability of fossil-fuel resources and global climate change caused by rising anthropogenic CO2 in the atmosphere. In this study, graphene oxide (GO) decorated with copper nanoparticles (Cu-NPs), hereafter referred to as Cu/GO, has been used to enhance photocatalytic CO2 reduction under visible-light. A rapid one-pot microwave process was used to prepare the Cu/GO hybrids with various Cu contents. The attributes of metallic copper nanoparticles (∼4-5 nm in size) in the GO hybrid are shown to significantly enhance the photocatalytic activity of GO, primarily through the suppression of electron-hole pair recombination, further reduction of GO's bandgap, and modification of its work function. X-ray photoemission spectroscopy studies indicate a charge transfer from GO to Cu. A strong interaction is observed between the metal content of the Cu/GO hybrids and the rates of formation and selectivity of the products. A factor of greater than 60 times enhancement in CO2 to fuel catalytic efficiency has been demonstrated using Cu/GO-2 (10 wt % Cu) compared with that using pristine GO.

12 CFR 345.43 - Content and availability of public file.

Code of Federal Regulations, 2011 CFR

2011-01-01

...; (3) A list of the bank's branches, their street addresses, and geographies; (4) A list of branches... street addresses, and geographies; (5) A list of services (including hours of operation, available loan...) A map of each assessment area showing the boundaries of the area and identifying the geographies...

Recovery of proteins from wastewater of tannery beamhouse operations: influence on the main pollution parameters.

PubMed

Marsal, A; Hernández, E; Cuadros, S; Puig, R; Bautista, E; Font, J

2010-01-01

The recovery of proteins from effluents of beamhouse operations in a hair-pulping process of hides is proposed. Precipitation with sulphuric acid at the isoelectric pH was chosen for protein recovery. The precipitates were characterized in order to study their potential uses. Apart from the protein nitrogen, the precipitate also contained a considerable content of fats resulting from the co-precipitation of natural fat of the hide in the wastewaters. The precipitation of the protein fraction resulted in a reduction of 80-85% of COD, whereas the protein content decreased 68-78%. This diminution of the contamination load led to a notable reduction of the tax on wastewater. The content of protein material in the precipitate varied from 15 to 44%. As expected, the protein in the precipitate did not result from the collagen decomposition of the hide but from soluble proteins such as albumin and globulin and remains of keratin. The precipitates obtained met the maximum limits of heavy metals according to legislation on organic fertilizers. The potential uses of the protein fraction recovered from tannery wastewaters are currently being investigated.

Contribution of the biological crust to the soil CO2 efflux in a Mediterranean ecosystem

NASA Astrophysics Data System (ADS)

Morillas, Lourdes; Bellucco, Veronica; Lo Cascio, Mauro; Marras, Serena; Spano, Donatella; Mereu, Simone

2016-04-01

Lately, the important role of the soil biological crust (hereafter biocrust) in Mediterranean ecosystems is emerging from a multitude of articles. It is becoming apparent that the biocrust has an important role in regulating ecosystem functions and that it interacts with the woody and herbaceous vegetation to a degree depending on the availability of water among other factors. Here we present the first results of a wider project and focus on the contribution of the biocrust to soil CO2 efflux, and on how the respiration of the biocrust responds to soil water content and temperature. A manipulative experiment was performed in a Mediterranean shrubland ecosystem in Sardinia (Italy) to assess the contribution of the bicocrust to soil CO2 efflux and to identify the main environmental drivers of the CO2 efflux in this ecosystem. For 19 months,in situ soil CO2 efflux was measured over three different surfaces: soil deprived of biocrust (hereafter Soil), biocrust (hereafter BC) and intact soil (hereafter Soil+BC). For these surfaces, three different approaches were used to investigate the dependency of CO2 efflux on soil temperature and soil water content, e.g. a simple linear regression, a multi-linear equation, and a modified version of the most common used Lloyd and Taylor model (Lloyd and Taylor, 1994). Results showed that CO2 effluxes emitted by Soil, BC and Soil+BC were differently driven by soil moisture and temperature: BC respiration was mainly controlled by soil moisture at 5 cm depth, whereas both soil temperature and water content at 20 cm depth determined Soil CO2 efflux. Soil temperature and water content at 5 cm depth drove Soil+BC respiration. We also found that biocrust can contribute substantially (up to 60%) to the total soil respiration depending on its moisture content. This contribution persists even in periods in which deeper soil layers are inactive, as small water pulses can activate lichens, mosses and cyanobacteria associated to the biocrust as well as the metabolism of carbon in soils, while deeper soil layers remain dormant. The important differences observed in CO2 efflux between Soil and Soil+BC suggest that projections on carbon budgets may underestimate soil CO2 efflux in spatially heterogeneous Mediterranean areas. Thus, our results highlight the relevance of accounting for the biocrust contribution to soil respiration and its responses to environmental drivers. The ongoing and planned activities to understand the full complexity of all factors determining respiration in water limited environments are briefly discussed. Lloyd, J., Taylor, J. A., 1994. On the temperature dependence of soil respiration. Funct. Ecol. 8, 315-323.

Effects of nitrogen source availability and bioreactor operating strategies on lutein production with Scenedesmus obliquus FSP-3.

PubMed

Ho, Shih-Hsin; Xie, Youping; Chan, Ming-Chang; Liu, Chen-Chun; Chen, Chun-Yen; Lee, Duu-Jong; Huang, Chieh-Chen; Chang, Jo-Shu

2015-05-01

In this study, the effects of the type and concentration of nitrogen sources on the cell growth and lutein content of an isolated microalga Scenedesmus obliquus FSP-3 were investigated. With batch culture, the highest lutein content (4.61 mg/g) and lutein productivity (4.35 mg/L/day) were obtained when using 8.0 mM calcium nitrate as the nitrogen source. With this best nitrogen source condition, the microalgae cultivation was performed using two bioreactor strategies (namely, semi-continuous and two-stage operations) to further enhance the lutein content and productivity. Using semi-continuous operation with a 10% medium replacement ratio could obtain the highest biomass productivity (1304.8 mg/L/day) and lutein productivity (6.01 mg/L/day). This performance is better than most related studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

3D Geological Modeling of CoalBed Methane (CBM) Resources in the Taldykuduk Block Karaganda Coal Basin, Kazakhstan

NASA Astrophysics Data System (ADS)

Sadykov, Raman; Kiponievich Ogay, Evgeniy; Royer, Jean-Jacques; Zhapbasbayev, Uzak; Panfilova, Irina

2015-04-01

Coal Bed Methane (CBM) is gas stored in coal layers. It can be extracted from wells after hydraulic fracturing and/or solvent injection, and secondary recovery techniques such as CO2 injection. Karaganda Basin is a very favorable candidate region to develop CBM production for the following reasons: (i) Huge gas potential; (ii) Available technologies for extracting and commercializing the gas produced by CBM methods; (iii) Experience in degassing during underground mining operations for safety reasons; (iv) Local needs in energy for producing electricity for the industrial and domestic market. The objectives of this work are to model the Taldykuduk block coal layers and their properties focusing on Coal Bed Methane production. It is motivated by the availability of large coal bed methane resources in Karaganda coal basin which includes 4 300 Bm3 equivalent 2 billion tons of coal (B = billion = 109) with gas content 15-25 m3/t of coal (for comparison San Juan basin (USA) has < 20 m3/t). The CBM reserves estimations are about: Saransk block, 26.3 Bm3 and Taldykuduk block, 23.5 Bm3. Methane (CH4) can be considered as an environmentally-friendly fuel compared to coal. Actually, the methane extracted during mining is released in the atmosphere, collecting it for recovering energy will reduce CO2 equivalent emissions by 36 Mt, good news regarding climate warming issues. The exploitation method will be based on a EOR technology consisting in injecting CO2 which replaces methane in pores because it has a higher adsorption capacity than CH4; exploiting CBM by CO2 injection provides thus a safe way to sequestrate CO2 in adsorbed form. The 3D geological model was built on Gocad/Skua using the following available data set: 926 wells and large area (7 x 12 km). No seismic data; coal type and chemical components (S, ash, …); unreliable available cross-section & maps due to old acquisition; quality mature coal; complex heterogeneous fractures network reported on geological cross sections; and utilization issues of the water extracted in the early stages of exploitation. The resulting 3D faulted model which includes more than 100 of faults will be further used to simulate the secondary recovery of methane by injecting CO2. The simulation will be carried out on a flow simulator assuming a two phase dimensionless formulation of CBM production in a double porosity model considering two domains: the matrix (m) and the fracture (f) for which the initial and boundary conditions are different. The resulting comprehensive 3D models had helped in better understanding the tectonic structures of the region, especially the relationships between the fault systems.

Choosing co-substrates to supplement biogas production from animal slurry--a life cycle assessment of the environmental consequences.

PubMed

Croxatto Vega, Giovanna Catalina; ten Hoeve, Marieke; Birkved, Morten; Sommer, Sven G; Bruun, Sander

2014-11-01

Biogas production from animal slurry can provide substantial contributions to reach renewable energy targets, yet due to the low methane potential of slurry, biogas plants depend on the addition of co-substrates to make operations profitable. The environmental performance of three underexploited co-substrates, straw, organic household waste and the solid fraction of separated slurry, were assessed against slurry management without biogas production, using LCA methodology. The analysis showed straw, which would have been left on arable fields, to be an environmentally superior co-substrate. Due to its low nutrient content and high methane potential, straw yields the lowest impacts for eutrophication and the highest climate change and fossil depletion savings. Co-substrates diverted from incineration to biogas production had fewer environmental benefits, due to the loss of energy production, which is then produced from conventional fossil fuels. The scenarios can often provide benefits for one impact category while causing impacts in another. Copyright © 2014 Elsevier Ltd. All rights reserved.

Life cycle analyses of CO2, energy, and cost for four different routes of microalgal bioenergy conversion.

PubMed

Ventura, Jey-R S; Yang, Benqin; Lee, Yong-Woo; Lee, Kisay; Jahng, Deokjin

2013-06-01

With a target production of 1000 ton of dry algae/yr, lipid content of 30 wt.%, and productivity of 30 g/m(2)-d in a 340-day annual operation, four common scenarios of microalgae bioenergy routes were assessed in terms of cost, energy, and CO2 inputs and outputs. Scenario 1 (biodiesel production), Scenario 2 (Scenario 1 with integrated anaerobic digestion system), Scenario 3 (biogas production), and Scenario 4 (supercritical gasification) were evaluated. Scenario 4 outperformed other scenarios in terms of net energy production (1282.42 kWh/ton algae) and CO2 removal (1.32 ton CO2/ton algae) while Scenario 2 surpassed the other three scenarios in terms of net cost. Scenario 1 produced the lowest energy while Scenario 3 was the most expensive bioenergy system. This study evaluated critical parameters that could direct the proper design of the microalgae bioenergy system with an efficient energy production, CO2 removal, and economic feasibility. Copyright © 2013 Elsevier Ltd. All rights reserved.

Increased bioactive lipids content in human subcutaneous and epicardial fat tissue correlates with insulin resistance.

PubMed

Błachnio-Zabielska, Agnieszka U; Baranowski, Marcin; Hirnle, Tomasz; Zabielski, Piotr; Lewczuk, Anna; Dmitruk, Iwona; Górski, Jan

2012-12-01

Obesity is a risk factor for metabolic diseases. Intramuscular lipid accumulation of ceramides, diacylglycerols, and long chain acyl-CoA is responsible for the induction of insulin resistance. These lipids are probably implicated in obesity-associated insulin resistance not only in skeletal muscle but also in fat tissue. Only few data are available about ceramide content in human subcutaneous adipose tissue. However, there are no data on DAG and LCACoA content in adipose tissue. The aim of our study was to measure the lipids content in human SAT and epicardial adipose tissue we sought to determine the bioactive lipids content by LC/MS/MS in fat tissue from lean non-diabetic, obese non-diabetic, and obese diabetic subjects and test whether the lipids correlate with HOMA-IR. We found, that total content of measured lipids was markedly higher in OND and OD subjects in both types of fat tissue (for all p < 0.001) as compared to LND group. In SAT we found positive correlation between HOMA-IR and C16:0-Cer (r = 0.79, p < 0.001) and between HOMA-IR and C16:0/18:2 DAG (r = 0.56, p < 0.001). In EAT we found a strong correlation between C16:0-CoA content and HOMA-IR (r = 0.73, p < 0.001). The study showed that in obese and obese diabetic patients, bioactive lipids content is greater in subcutaneous and epicardial fat tissue and the particular lipids content positively correlates with HOMA-IR.

Thermophilic anaerobic co-digestion of cattle manure with agro-wastes and energy crops: comparison of pilot and full scale experiences.

PubMed

Cavinato, C; Fatone, F; Bolzonella, D; Pavan, P

2010-01-01

The paper deals with the benefits coming from the application of a proper process temperature (55 degrees C) instead of a 'reduced' thermophilic range (47 degrees C), that is often applied in European anaerobic co-digestion plants. The experimental work has pointed out that biogas production improve from 0.45 to 0.62 m(3)/kg VS operating at proper thermophilic conditions. Moreover, also methane content was higher: from 52% to 61%. A general improvement in digester behaviour was clear also considering the stability parameters comparison (pH, ammonia, VFA content). The second part of the study takes into account the economic aspects related to the capital cost of anaerobic digestion treatment with a 1 MW co-generation unit fro heat and power production (CHP). Moreover, the economic balance was also carried out considering the anaerobic supernatants treatment for nitrogen removal. The simulation showed how a pay-back-time of 2.5 yr and between 3 and 5 yr respectively could be determined when the two options of anaerobic digestion only and together with the application of a nitrogen removal process were considered.

Group-multicast capable optical virtual private ring with contention avoidance

NASA Astrophysics Data System (ADS)

Peng, Yunfeng; Du, Shu; Long, Keping

2008-11-01

A ring based optical virtual private network (OVPN) employing contention sensing and avoidance is proposed to deliver multiple-to-multiple group-multicast traffic. The network architecture is presented and its operation principles as well as performance are investigated. The main contribution of this article is the presentation of an innovative group-multicast capable OVPN architecture with technologies available today.

A review of satellite-based methods of estimating live fuel moisture content for fire danger assessment: moving towards operational products

USDA-ARS?s Scientific Manuscript database

One of the primary variables affecting ignition and spread of wildfire is fuel moisture content (FMC), which is the ratio of water mass to dry mass in living and dead plant material. Because dead FMC may be estimated from available weather data, remote sensing is needed to monitor the spatial distr...

78 FR 46940 - Environmental Impacts Statements; Notice of Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-02

... Air Station Key West Airfield Operations Review Period Ends: 09/03/2013, Contact: Greg Timoney 904-542...-0662. EIS No. 20130228, Final EIS, USACE, CO, Chatfield Reservoir Storage Reallocation, Review Period...

Structure of carbon monoxide time variations in the atmospheric thickness over Central Eurasia (Issyk Kul Monitoring Station)

NASA Astrophysics Data System (ADS)

Aref'ev, V. N.; Kashin, F. V.; Orozaliev, M. D.; Sizov, N. I.; Sinyakov, V. P.; Sorokina, L. I.

2013-03-01

The results of measurements of the CO content in the atmospheric thickness by the method of solar molecular-absorption spectroscopy are presented. Over 87 months of observations, the annual mean CO content decreased by ˜19% at a mean rate of changes equal to -(0.14 ± 0.02) atm cm per year. Maxima and minima of seasonal variations most often fall on February and September, respectively. The mean overall amplitude of changes in the CO content during the annual cycle is about 50% of the mean value. The Fourier analysis revealed variations in the CO composition with periods from 3 to 84 months. A simple statistical model satisfactorily describes time changes in the CO content in the atmospheric thickness. The results of measurements of the CO content in the atmospheric thickness are compared with the data of CO measurements in samples of surface air at stations of the Global Atmospheric Watch.

Improving coenzyme Q8 production in Escherichia coli employing multiple strategies.

PubMed

Xu, Wen; Yang, Shuiyun; Zhao, Junchao; Su, Tingting; Zhao, Liangrui; Liu, Jiankang

2014-08-01

Coenzyme Q (CoQ) is a medically valuable compound and a high yielding strain for CoQ will have several benefits for the industrial production of CoQ. To increase the CoQ(8) content of E. coli, we blocked the pathway for the synthesis of menaquinone by deleting the menA gene. The blocking of menaquinone pathway increased the CoQ(8) content by 81 % in E. coli (ΔmenA). To study the CoQ producing potential of E. coli, we employed previous known increasing strategies for systematic metabolic engineering. These include the supplementation with substrate precursors and the co-expression of rate-limiting genes. The co-expression of dxs-ubiA and the supplementation with substrate precursors such as pyruvate (PYR) and parahydroxybenzoic acid (pHBA) increased the content of CoQ(8) in E. coli (ΔmenA) by 125 and 59 %, respectively. Moreover, a 180 % increase in the CoQ(8) content in E. coli (ΔmenA) was realized by the combination of the co-expression of dxs-ubiA and the supplementation with PYR and pHBA. All in all, CoQ(8) content in E. coli increased 4.06 times by blocking the menaquinone pathway, dxs-ubiA co-expression and the addition of sodium pyruvate and parahydroxybenzoic acid to the medium. Results suggested a synergistic effect among different metabolic engineering strategies.

Applying the Verona coding definitions of emotional sequences (VR-CoDES) to code medical students' written responses to written case scenarios: Some methodological and practical considerations.

PubMed

Ortwein, Heiderose; Benz, Alexander; Carl, Petra; Huwendiek, Sören; Pander, Tanja; Kiessling, Claudia

2017-02-01

To investigate whether the Verona Coding Definitions of Emotional Sequences to code health providers' responses (VR-CoDES-P) can be used for assessment of medical students' responses to patients' cues and concerns provided in written case vignettes. Student responses in direct speech to patient cues and concerns were analysed in 21 different case scenarios using VR-CoDES-P. A total of 977 student responses were available for coding, and 857 responses were codable with the VR-CoDES-P. In 74.6% of responses, the students used either a "reducing space" statement only or a "providing space" statement immediately followed by a "reducing space" statement. Overall, the most frequent response was explicit information advice (ERIa) followed by content exploring (EPCEx) and content acknowledgement (EPCAc). VR-CoDES-P were applicable to written responses of medical students when they were phrased in direct speech. The application of VR-CoDES-P is reliable and feasible when using the differentiation of "providing" and "reducing space" responses. Communication strategies described by students in non-direct speech were difficult to code and produced many missings. VR-CoDES-P are useful for analysis of medical students' written responses when focusing on emotional issues. Students need precise instructions for their response in the given test format. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Tuning exchange bias by Co doping in Mn₅₀Ni{sub 41–x}Sn₉Co{sub x} melt-spun ribbons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, D. W.; Li, G. K.; Wang, S. Q.

2014-09-14

In Mn₅₀Ni{sub 41–x}Sn₉Co{sub x} ribbons, the exchange bias field is very sensitive to the Co content. Based on both theoretical and experimental studies, it has been found that with increasing Co content, the pinned phase (ferromagnetic phase) remains almost unchanged while the pinning phase is changed from a canonical spin glass to a cluster spin glass and finally to a ferromagnetic phase. Changing the Co content in Mn₅₀Ni{sub 41–x}Sn₉Co{sub x} alloys has been proven to be an effective way of tuning the magnetic anisotropy and the phase structure of the pinning phase. With different Co contents, a continuous tuning ofmore » the exchange bias field from 345 Oe to 3154 Oe is realized.« less

Current use of carbonate rocks and lime for controlling emissions from coal-fired plants in Kentucky

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dever, G.R. Jr.

1993-03-01

Seven coal-fired power plants in Kentucky currently are operating wet-scrubbing systems for flue-gas desulfurization. Atmospheric fluidized-bed combustion (AFBC) units are being used for SO[sub 2] emission control at a petroleum refinery, and a 160-MW utility-scale AFBC demonstration plant is being operated by the Tennessee Valley Authority. A lime-based spray-dryer reactor system has been installed on an industrial boiler, and a spray-dryer system is being tested at a utility pilot-plant facility. Four of the seven power plants operate limestone-based wet-scrubbing systems and require about 885,000 tons of stone per year. Stone is obtained from Mississippian limestones, principally the Ste. Genevieve Limestone,more » produced at four quarries in Kentucky, Indiana, and Illinois. Scrubber limestone specifications include CaCO[sub 3] content (minimum 88--90%), MgCO[sub 3] content (maximum 4--6%), and grindability (maximum Bond Work Index of 11--12). Three power plants operate lime-based scrubbers, requiring about 250,000 tons of lime per year. The scrubbers currently use (1) lime manufactured from an Ordovician dolomitic limestone, mined in north-central Kentucky, and (2) carbide lime, a chemical-industry byproduct. Fluidized-bed units at the petroleum refinery require about 100,000 tons of sorbent stone per year. The sorbent consists of about equal amounts of Silurian dolomite from Ohio and Ordovician dolomitic limestone from Kentucky. The utility-scale AFBC demonstration plant uses a limestone sorbent and currently requires about 200,000 tons of stone per year. Limestone is obtained from the Ste. Genevieve in western Kentucky.« less

Influence of carbides and microstructure of CoCrMo alloys on their metallic dissolution resistance.

PubMed

Valero-Vidal, C; Casabán-Julián, L; Herraiz-Cardona, I; Igual-Muñoz, A

2013-12-01

CoCrMo alloys are passive and biocompatible materials widely used as joint replacements due to their good mechanical properties and corrosion resistance. Electrochemical behaviour of thermal treated CoCrMo alloys with different carbon content in their bulk alloy composition has been analysed. Both the amount of carbides in the CoCrMo alloys and the chemical composition of the simulated body fluid affect the electrochemical properties of these biomedical alloys, thus passive dissolution rate was influenced by the mentioned parameters. Lower percentage of carbon in the chemical composition of the bulk alloy and thermal treatments favour the homogenization of the surface (less amount of carbides), thus increasing the availability of Cr to form the oxide film and improving the corrosion resistance of the alloy. © 2013.

Influence of operating conditions on the air gasification of dry refinery sludge in updraft gasifier

NASA Astrophysics Data System (ADS)

Ahmed, R.; Sinnathambi, C. M.

2013-06-01

In the present work, details of the equilibrium modeling of dry refinery sludge (DRS) are presented using ASPEN PLUS Simulator in updraft gasifier. Due to lack of available information in the open journal on refinery sludge gasification using updraft gasifier, an evaluate for its optimum conditions on gasification is presented in this paper. For this purpose a Taguchi Orthogonal array design, statistical software is applied to find optimum conditions for DRS gasification. The goal is to identify the most significant process variable in DRS gasification conditions. The process variables include; oxidation zone temperature, equivalent ratio, operating pressure will be simulated and examined. Attention was focused on the effect of optimum operating conditions on the gas composition of H2 and CO (desirable) and CO2 (undesirable) in terms of mass fraction. From our results and finding it can be concluded that the syngas (H2 & CO) yield in term of mass fraction favors high oxidation zone temperature and at atmospheric pressure while CO2 acid gas favor at a high level of equivalent ratio as well as air flow rate favoring towards complete combustion.

Role of Cobalt Content in Improving the Low-Temperature Performance of Layered Lithium-Rich Cathode Materials for Lithium-Ion Batteries.

PubMed

Kou, Jianwen; Chen, Lai; Su, Yuefeng; Bao, Liying; Wang, Jing; Li, Ning; Li, Weikang; Wang, Meng; Chen, Shi; Wu, Feng

2015-08-19

Layered lithium-rich cathode material, Li1.2Ni0.2-xCo2xMn0.6-xO2 (x = 0-0.05) was successfully synthesized using a sol-gel method, followed by heat treatment. The effects of trace amount of cobalt doping on the structure, morphology, and low-temperature (-20 °C) electrochemical properties of these materials are investigated systematically. X-ray diffraction (XRD) results confirm that the Co has been doped into the Ni/Mn sites in the transition-metal layers without destroying the pristine layered structure. The morphological observations reveal that there are no changes of morphology or particle size after Co doping. The electrochemical performance results indicate that the discharge capacities and operation voltages are drastically lowered along with the decreasing temperature, but their fading rate becomes slower when increasing the Co contents. At -20 °C, the initial discharge capacity of sample with x = 0 could retain only 22.1% (57.3/259.2 mAh g(-1)) of that at 30 °C, while sample with x = 0.05 could maintain 39.4% (111.3/282.2 mAh g(-1)). Activation energy analysis and electrochemical impedance spectroscopy (EIS) results reveal that such an enhancement of low-temperature discharge capacity is originated from the easier interface reduction reaction of Ni(4+) or Co(4+) after doping trace amounts of Co, which decreases the activation energy of the charge transfer process above 3.5 V during discharging.

Soil organic matter content: a non-liner control on microbial respiration in soils

NASA Astrophysics Data System (ADS)

Schnecker, Jörg; Grandy, Stuart

2016-04-01

It is widely assumed that microbial activity and respiration rates respond linearly to substrate concentrations, irrespective of substrate chemical characteristics, but this assumption remains largely untested. We know that microbial decomposition of soil organic matter (SOM) and the amount of CO2 respired from soil depends on substrate availability. While soils with high SOM concentrations will have higher respiration rates than soils with low SOM concentrations, the specific relationship between substrate quantity and CO2 respired and its underlying mechanisms has robust theoretical, modeling, and management implications. In a lab incubation experiment, we amended a mixture of agricultural soil and sand with increasing amounts of one of three plant residues differing in their C/N ratio (clover C/N 14; rye C/N 23 and wheat straw C/N 110). Keeping the soil/sand mixture at a constant ratio, we obtained 9 levels of organic carbon (OC) content ranging from 0.25% to 5.7%. The sand-soil-residue mixtures were then incubated at constant temperature and water contents for a total of 63 days. Our results show that across substrates CO2 production increased with increasing OC content following a sigmoidal curve function instead of the expected linear one. A breakpoint analysis for the respiration curve of rye revealed two significant break points at 1.3 and 3.8 % OC. The three individual linear relations might be shaped by spatial separation of substrate and microbes and the interaction of the microbes themselves. In the first "survival" phase up to 1.3 % OC, more substrate leads to the survival of more microbes. However, microbial growth does not result in the discovery of new resources. In the "expansion" phase (1.3 % OC to 3.8 % OC), microbial growth is successful and microbes can exploit new resources. Finally, in the "competition" phase microbes start to compete for space and resources, which leads to a decrease in decomposition and respiration. While the results for clover were similar to rye, different amounts of straw resulted in an almost linear relationship between OC content and respiratory loss. The low N content of straw may explain this, limiting microbial growth and the exploration for new resources. Microbes in the straw treatment likely remained in the "survival" phase. Our findings of a non-linear decrease of CO2 production with decreasing OC content indicate that spatial separation as an inherent property of SOM content is an important control on decomposition of soil organic matter. Knowledge of this controlling effect might be beneficial in many ways. For example, even small additions of plant residues to agricultural systems might strongly enhance N availability to microbes and plants. Further, the spatial distribution of new C inputs may regulate its potential to be decomposed or stabilized. Finally, our results will help to improve model parameterization and predictions about microbial limitations and potential changes in decomposition under a future climate.

Studies on comonomer compositional distribution of bacterial poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)s and thermal characteristics of their factions.

PubMed

Feng, Lidan; Watanabe, Takumi; Wang, Yi; Kichise, Tomoyasu; Fukuchi, Takeshi; Chen, Guo-Qiang; Doi, Yoshiharu; Inoue, Yoshio

2002-01-01

The comonomer-unit compositional distributions have been investigated for bacterial poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HH)] samples with 3HH unit content of 13.8, 18.0, 22.0, and 54.0 mol %. They were comonomer compositionally fractionated using chloroform/n-heptane mixed solvent at ambient temperature. The fractionation of P(3HB-co-18.0 mol %3HH) and P(3HB-co-22.0 mol % 3HH), which could not be carried out effectively at room temperature, were refractionated at 70 degrees C in the mixed solvent. Fractions with different 3HH unit content in a wide range (from 4.4 to 80.7 mol %) were obtained. By use of these fractions with narrow compositional distribution, the comonomer composition dependence of thermal properties was investigated by differential scanning calorimetry. The melting point (T(m)) and heat of fusion (DeltaH) decreased as the 3HH unit content increased in the range of low 3HH content (<40 mol %), while they increased as the 3HH unit content increased in the high 3HH content range (>70 mol %). The minimum T(m) and DeltaH values were found to exist at 3HH unit content of about 60 mol %. The glass transition temperature (T(g)) decreased linearly with the increase of 3HH unit content. The values of T(m), DeltaH, and T(g) of P(3HB-co-3HH)s were compared with those of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxypropionate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), and the effects of comonomer types on the thermal properties were revealed.

Manganese nodule resources in the northeastern equatorial Pacific

USGS Publications Warehouse

McKelvey, V.E.; Wright, Nancy A.; Rowland, Robert W.

1979-01-01

Recent publication of maps at scale 1:1,000,000 of the northeastern equatorial Pacific region showing publicly available information on the nickel plus copper content of manganese nodules has made it possible to outline the prime area between the Clarion and Clipperton fracture zones which has been the focus of several recent scientific and commercial studies. The area, defined as that in which the nodules contain more than 1.8 percent nickel plus copper, is about 2o5 million km2. The available evidence suggests that about half of it contains nodules in concentration (reported in wet weight units) greater than 5 kg/m2 and averaging 11.9 kg/m2. If we assume that 20 percent of the nodules in this area of 1.25 million km2 are recoverable, its potential recoverable resources are about 2.1 billion dry metric tons of nodules averaging about 25 percent Mn, 1.3 percent Ni, 1.0 percent Cu, 0.22 percent Co, and 0.05 percent Mo—enough to support about 27 mining operations each producing an average of 75 million metric tons of nodules over their lifetimes. Estimates based on other plausible assumptions would be higher or lower, but of the same order of magnitude. Thus it seems probable that the magnitude of the potentially recoverable nodule resources of the Clarion-Clipperton prime area—the most promising now known—is at most in the range of several tens of the average-size operations postulated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, D.E.

Assay procedures for analysis of four groups of allelochemicals in Artemisia tridentata, big sagebrush, were established. Growth of Artemisia under high and low light at three CO/sub 2/ levels demonstrated that this species also undegoes a ''dilution'' of the leaf nitrogen content and is useful as test species for herbivory response to CO/sub 2/ induced effects. The initiial experiment also showed that high irradiance is a necessary growth condition. Plants from a single population of A. Tridentata were grown at the Duke Phytotron in three CO/sub 2/ regimed and fed to two species of grasshoppers. Sagabrush plants grew more andmore » had lower leaf nitrogen contents as CO/sub 2/ concentration increased. However, the plants had on average lowere leaf carbon as well as lower leaf niitrogen contents with elevated CO/sub 2/. The source of the lower leaf nutritional value does not appear to be solely an increase in carbon content. Grasshopper consumption was greater on leaves from elevated future and from reduced historical CO/sub 2/ regimes, compared to the current concentration. The increased consumption of leaves from elevated CO/sub 2/ is in agreement with previous results. Grasshopper consumption was significantly related to leaf allelochemical content, but not to leaf nitrogen content. The consumption difference among CO/sub 2/ regimes appeared to result from allelochemical differences, which in turn may result from genetic variation or from CO/sub 2/ treatments. 17 refs., 2 figs., 4 tabs.« less

A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography.

PubMed

Carlier, Stéphane; Didday, Rich; Slots, Tristan; Kayaert, Peter; Sonck, Jeroen; El-Mourad, Mike; Preumont, Nicolas; Schoors, Dany; Van Camp, Guy

2014-06-01

We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization. Copyright © 2014 Elsevier Inc. All rights reserved.

12 CFR 563e.43 - Content and availability of public file.

Code of Federal Regulations, 2011 CFR

2011-01-01

... savings association's branches, their street addresses, and geographies; (4) A list of branches opened or... street addresses, and geographies; (5) A list of services (including hours of operation, available loan... boundaries of the area and identifying the geographies contained within the area, either on the map or in a...

Chemical-to-Electricity Carbon: Water Device.

PubMed

He, Sisi; Zhang, Yueyu; Qiu, Longbin; Zhang, Longsheng; Xie, Yun; Pan, Jian; Chen, Peining; Wang, Bingjie; Xu, Xiaojie; Hu, Yajie; Dinh, Cao Thang; De Luna, Phil; Banis, Mohammad Norouzi; Wang, Zhiqiang; Sham, Tsun-Kong; Gong, Xingao; Zhang, Bo; Peng, Huisheng; Sargent, Edward H

2018-05-01

The ability to release, as electrical energy, potential energy stored at the water:carbon interface is attractive, since water is abundant and available. However, many previous reports of such energy converters rely on either flowing water or specially designed ionic aqueous solutions. These requirements restrict practical application, particularly in environments with quiescent water. Here, a carbon-based chemical-to-electricity device that transfers the chemical energy to electrical form when coming into contact with quiescent deionized water is reported. The device is built using carbon nanotube yarns, oxygen content of which is modulated using oxygen plasma-treatment. When immersed in water, the device discharges electricity with a power density that exceeds 700 mW m -2 , one order of magnitude higher than the best previously published result. X-ray absorption and density functional theory studies support a mechanism of operation that relies on the polarization of sp 2 hybridized carbon atoms. The devices are incorporated into a flexible fabric for powering personal electronic devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Solid Oxide Fuel Cell short stack performance testing - part B: Operation in carbon capture applications and degradation issues

NASA Astrophysics Data System (ADS)

Mastropasqua, L.; Campanari, S.; Brouwer, J.

2017-12-01

The need to experimentally understand the performance of Solid Oxide Fuel Cells (SOFC) stacks under Carbon Capture and Storage (CCS) mode operating conditions, hence with anode recirculation, has prompted this two-part study. The steady state performance of a 6-cell short stack of Y2O3 stabilised Zirconia (YSZ) with Ni/YSZ anodes and composite Sr-doped LaMnO3 (LSM)/YSZ cathodes is experimentally evaluated. In Part A, the electrical and environmental performance are assessed and the results are compared with the commercial full-scale micro-Combined Heat and Power system, which comprises the same cells. In Part B of this work, a specific set of stack operating conditions important to CCS applications is explored. The experimental inlet composition is changed in order to reproduce a simulated syngas in CCS mode operation for different fuel utilisation factors. Operation with the simulated anode recycle syngas leads to lower voltage when the anode recycle is lower, mainly due to higher internal reforming and polarisation losses. A clear voltage trend is observed when the amount of CO content in the inlet fuel is increased, signalling an improvement of the polarisation performance at constant current density and fixed inlet equivalent hydrogen content. Stack degradation is measured and results in line with manufacturer's data.

Registered Nurses working together with family members of older people.

PubMed

Weman, Karin; Fagerberg, Ingegerd

2006-03-01

The aim of the study was to reach a more profound understanding, through looking at nurses' working situation, of those factors that influence how nurses are able to work together with family members of older people living in nursing homes or similar facilities. Working with the care of older people as a Registered Nurse provides a varied job with many challenges. Nurses have to co-operate with family members of those in community health care. Co-operation is important and necessary for all involved. Nurses working in elder care in a geographically defined area received a questionnaire with three open-ended questions, on the difficulties and/or problems involved with working together with family members, and the positive or negative aspects of this co-operation. Analysis was carried out using the latent content analysis method. Three themes, problems within the system, interaction with families and caring in nursing work, are presented with categories and their subcategories. The nurses wanted their superior to be a nurse so that their working situation would be better understood. Appreciation from their superior and family members was also a very important part of their work as nurses in community health care. The frequent changes and the lack of time in the work of elder care often put nurses under considerable psychological pressure. For the most part family members are a resource for the elder, but sometimes they will avoid contact, which will make co-operating difficult. Registered Nurses and family members are dependent on each other in their care of the elder. Relevance to clinical practice. More attention should be paid to the working situation of Registered Nurses in community health care, and their ability to work together with family members of older people.

Effect of co-administration of cassava (Manihot esculenta Crantz) rich diet and alcohol in rats.

PubMed

Boby, R G; Indira, M

2004-01-01

The effects of co-administration of a cassava rich diet and alcohol in rats were investigated. The animals were divided into four groups (1) Control, (2) Alcohol, (3) Cassava and (4) Alcohol + Cassava. Consumption of alcohol along with cassava reduced the alcohol induced toxicity which was evidenced by the lower activities of GOT, GPT, GGT, acid phosphatase and alkaline phosphatase in the liver and serum of co-administered group. The pyruvate content in the blood increased while the lactate content, lactate/pyruvate ratio and the activity of LDH decreased in the blood due to co-administration. The blood cyanide content, serum thiocyanate content and the activities of rhodanase and beta-glucuronidase increased on co-administration. The histopathological studies also revealed that co-administration reduced the alcohol induced toxicity.

QEPAS based ppb-level detection of CO and N2O using a high power CW DFB-QCL.

PubMed

Ma, Yufei; Lewicki, Rafał; Razeghi, Manijeh; Tittel, Frank K

2013-01-14

An ultra-sensitive and selective quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor platform was demonstrated for detection of carbon monoxide (CO) and nitrous oxide (N2O). This sensor used a state-of-the art 4.61 μm high power, continuous wave (CW), distributed feedback quantum cascade laser (DFB-QCL) operating at 10°C as the excitation source. For the R(6) CO absorption line, located at 2169.2 cm(-1), a minimum detection limit (MDL) of 1.5 parts per billion by volume (ppbv) at atmospheric pressure was achieved with a 1 sec acquisition time and the addition of 2.6% water vapor concentration in the analyzed gas mixture. For the N2O detection, a MDL of 23 ppbv was obtained at an optimum gas pressure of 100 Torr and with the same water vapor content of 2.6%. In both cases the presence of water vapor increases the detected CO and N2O QEPAS signal levels as a result of enhancing the vibrational-translational relaxation rate of both target gases. Allan deviation analyses were performed to investigate the long term performance of the CO and N2O QEPAS sensor systems. For the optimum data acquisition time of 500 sec a MDL of 340 pptv and 4 ppbv was obtained for CO and N2O detection, respectively. To demonstrate reliable and robust operation of the QEPAS sensor a continuous monitoring of atmospheric CO and N2O concentration levels for a period of 5 hours were performed.

The tip of the iceberg: the frequency content of the δ Sct star HD 50844 from CoRoT space photometry

NASA Astrophysics Data System (ADS)

Poretti, E.; Mantegazza, L.; Rainer, M.; Uytterhoeven, K.; Michel, E.; Baglin, A.; Auvergne, M.; Catala, C.; Samadi, R.; Rodríguez, E.; Garrido, R.; Amado, P.; Martín-Ruiz, S.; Moya, A.; Suárez, J. C.; Baudin, F.; Zima, W.; Alvarez, M.; Mathias, P.; Paparó, M.; Pápics, P.; Plachy, E.

2009-09-01

It has been suggested that the detection of a wealth of very low amplitude modes in δ Sct stars was only a matter of signal-to-noise ratio. Access to this treasure, impossible from the ground, is one of the scientific aims of the space mission CoRoT, developed and operated by CNES. This work presents the results obtained on HD 50844: the 140,016 datapoints allowed us to reach the level of 10-5 mag in the amplitude spectra. The frequency analysis of the CoRoT timeseries revealed hundreds of terms in the frequency range 0-30 d-1. The initial guess that δ Sct stars have a very rich frequency content is confirmed. The spectroscopic mode identification gives theoretical support since very high-degree modes (up to = 14) are identified. We also prove that cancellation effects are not sufficient in removing the flux variations associated to these modes at the noise level of the CoRoT measurements. The ground-based observations indicate that HD 50844 is an evolved star that is slightly underabundant in heavy elements, located on the Terminal Age Main Sequence. The predominant term (f1 = 6.92 d-1) has been identified as the fundamental radial mode combining ground-based photometric and spectroscopic data.

Diagenesis of lower Cretaceous pelagic carbonates, North Atlantic: Paleoceanographic signals obscured

USGS Publications Warehouse

Frank, T.D.; Arthur, M.A.; Dean, W.E.

1999-01-01

The stable isotope and minor element geochemistry of Neocomian (Lower Cretaceous) pelagic carbonates of the North Atlantic Basin (Deep Sea Drilling Project Sites 105, 367, 387, 391, and 603) was examined to develop a diagenetic model for pelagic limestones. In particular, we hoped to test the fidelity of whole-rock geochemical records as paleoceanographic indicators for pelagic deposits of pre-Aptian age, in which individual microfossils are not available for analysis. Data indicate that in addition to depth of burial, rhythmic variations in primary carbonate content have strongly controlled diagenetic patterns and associated geochemical signatures in these Neocomian sequences. Samples become increasingly depleted in Sr and 18O with increasing CaCO3 content. Within individual sedimentary sections, substantial decreases in Sr/Ca ratios and ??18O values are evident over a range of 4 to 98% CaCO3. However, even over a relatively narrow range of 50 to 98% CaCO3 a 2.5%c variation in ??18O values and a change of a factor of 1.7 in Sr/Ca ratios are observed. Carbon isotope compositions do not vary as extensively with CaCO3 content, but carbonate-rich intervals tend to be relatively depleted in 13C. Petrographic analysis reveals that these geochemical patterns are related to the transfer of CaCO3 from carbonate-poor intervals (calcareous shales and marlstones) to adjacent carbonate-rich intervals (limestones) during burial compaction and pressure solution. This process results in the addition of diagenetic cement to carbonate-rich intervals to produce a bulk composition that is relatively depleted in Sr and 18O and, at the same time, enables the retention of more-or-less primary carbonate that is relatively enriched in Sr and 18O in adjacent carbonate-poor intervals. Thus, although cyclic variations in CaCO3 content are primary in the Neocomian sequences examined, measured variations in Sr/Ca ratios and ??18O values are not and, as such, do not provide reliable proxies for past variations in climate, oceanographic conditions, or global ice volume.

Scale-up and large-scale production of Tetraselmis sp. CTP4 (Chlorophyta) for CO2 mitigation: from an agar plate to 100-m3 industrial photobioreactors.

PubMed

Pereira, Hugo; Páramo, Jaime; Silva, Joana; Marques, Ana; Barros, Ana; Maurício, Dinis; Santos, Tamára; Schulze, Peter; Barros, Raúl; Gouveia, Luísa; Barreira, Luísa; Varela, João

2018-03-23

Industrial production of novel microalgal isolates is key to improving the current portfolio of available strains that are able to grow in large-scale production systems for different biotechnological applications, including carbon mitigation. In this context, Tetraselmis sp. CTP4 was successfully scaled up from an agar plate to 35- and 100-m 3 industrial scale tubular photobioreactors (PBR). Growth was performed semi-continuously for 60 days in the autumn-winter season (17 th October - 14 th December). Optimisation of tubular PBR operations showed that improved productivities were obtained at a culture velocity of 0.65-1.35 m s -1 and a pH set-point for CO 2 injection of 8.0. Highest volumetric (0.08 ± 0.01 g L -1 d -1 ) and areal (20.3 ± 3.2 g m -2 d -1 ) biomass productivities were attained in the 100-m 3 PBR compared to those of the 35-m 3 PBR (0.05 ± 0.02 g L -1 d -1 and 13.5 ± 4.3 g m -2 d -1 , respectively). Lipid contents were similar in both PBRs (9-10% of ash free dry weight). CO 2 sequestration was followed in the 100-m 3 PBR, revealing a mean CO 2 mitigation efficiency of 65% and a biomass to carbon ratio of 1.80. Tetraselmis sp. CTP4 is thus a robust candidate for industrial-scale production with promising biomass productivities and photosynthetic efficiencies up to 3.5% of total solar irradiance.

Field approach to mining-dump revegetation by application of sewage sludge co-compost and a commercial biofertilizer.

PubMed

Sevilla-Perea, A; Mingorance, M D

2015-08-01

An approach was devised for revegetation of a mining dump soil, sited in a semiarid region, with basic pH as well as Fe and Mn enrichment. A field experiment was conducted involving the use of co-compost (a mixture of urban sewage sludge and plant remains) along with a commercial biofertilizer (a gel suspension which contains arbuscular mycorrhizal fungus) to reinforce the benefits of the former. Four treatments were studied: unamended soil; application of conditioners separately and in combination. Pistachio, caper, rosemary, thyme and juniper were planted. We evaluated the effects of the treatments using soil quality (physicochemical properties, total content of hazardous elements, nutrient availability, microbial biomass and enzyme activities) and plant establishment indicators (survival, growth, vigor, nutrient content in leaves, nutrient balances and mycorrhizal root colonization). Thyme and juniper did not show a suitable survival rate (<50%) whereas 70-100% of the pistachio, rosemary and caper survived for at least 27 months. In unamended soil, plant growth was severely hampered by P, N, K and Zn deficiencies as well as Fe and Mn excess. Overall, the treatments affected the soil and plant indicators as follows: biofertilizer + co-compost > co-compost > biofertilizer > unamended. The application of co-compost was therefore essential with regard to improving soil fertility; furthermore, it increased leaf N and P content, whereas leaf Fe and Mn concentrations showed a decrease. The combined treatment, however, provided the best results. The positive interaction between the two soil conditioners might be related to the capacity of the biofertilizer to increase nutrient uptake from the composted residue, and to protect plants against Fe and Mn toxicity. Copyright © 2015 Elsevier Ltd. All rights reserved.

Continuously Regenerable Freeze-Out CO2 Control Technology

NASA Technical Reports Server (NTRS)

Fricker, John; Dyer, Chris; Myers, Jeff; Patten, Rich; Paul, Heather

2007-01-01

Carbon dioxide (CO2) removal technology development for portable life support systems (PLSS) has traditionally concentrated in the areas of solid and liquid chemical sorbents and semi-permeable membranes. Most of these systems are too heavy in gravity environments, require prohibitive amounts of consumables for operation on long term planetary missions, or are inoperable on the surface of Mars due to the presence of a CO2 atmosphere. This paper describes the effort performed to mature an innovative CO2 removal technology that meets NASA s planetary mission needs while adhering to the important guiding principles of simplicity, reliability, and operability. A breadboard cryogenic carbon dioxide scrubber (Cryo Scrubber) for a closed loop cryogenic PLSS was developed, designed, and tested, and a conceptual design suitable for a PLSS was developed based on the results of the breadboard testing. The Cryo Scrubber freezes CO2 and other trace contaminants out of expired vent loop gas using cooling available from a liquid oxygen (LOX) based PLSS. The device is continuously regenerable, with solid CO2 being removed from the cold freeze-out surfaces, sublimated, and vented overboard. Duration is limited only by the supply of LOX stored in the PLSS. Simplicity, reliability, and operability are universally important criteria for critical hardware on long duration Lunar or Mars missions. The Cryo Scrubber has no moving parts, requires no additional consumables, and uses no electrical power, contributing to its simplicity and reliability. It is easy to use; no operator action is required to prepare, use, or shut down the Cryo Scrubber, and it does not require charging or regeneration. The versatility of the concept allows for operation on earth, the moon, and Mars, and in microgravity.

Photosynthesis in chlorolichens: the influence of the habitat light regime.

PubMed

Piccotto, Massimo; Tretiach, Mauro

2010-11-01

The hypothesis that CO(2) gas exchange and chlorophyll a fluorescence (ChlaF) of lichens vary according to the light regimes of their original habitat, as observed in vascular plants, was tested by analysing the photosynthetic performance of 12 populations of seven dorsoventral, foliose lichens collected from open, south-exposed rocks to densely shaded forests. Light response curves were induced at optimum thallus water content and ChlaF emission curves at the species-specific photon flux at which the quantum yield of CO(2) assimilation is the highest and is saturating the photosynthetic process. Photosynthetic pigments were quantified in crude extracts. The results confirm that the maximum rate of gross photosynthesis is correlated with the chlorophyll content of lichens, which is influenced by light as well as by nitrogen availability. Like leaves, shade tolerant lichens emit more ChlaF than sun-loving ones, whereas the photosynthetic quantum conversion is higher in the latter.

Modelling the combustion of charcoal in a model blast furnace

NASA Astrophysics Data System (ADS)

Shen, Yansong; Shiozawa, Tomo; Yu, Aibing; Austin, Peter

2013-07-01

The pulverized charcoal (PCH) combustion in ironmaking blast furnaces is abstracting remarkable attention due to various benefits such as lowering CO2 emission. In this study, a three-dimensional CFD model is used to simulate the flow and thermo-chemical behaviours in this process. The model is validated against the experimental results from a pilot-scale combustion test rig for a range of conditions. The typical flow and thermo-chemical phenomena is simulated. The effect of charcoal type, i.e. VM content is examined, showing that the burnout increases with VM content in a linear relationship. This model provides an effective way for designing and optimizing PCH operation in blast furnace practice.

Effect of amine structure on CO2 capture by polymeric membranes.

PubMed

Taniguchi, Ikuo; Kinugasa, Kae; Toyoda, Mariko; Minezaki, Koki

2017-01-01

Poly(amidoamine)s (PAMAMs) incorporated into a cross-linked poly(ethylene glycol) exhibited excellent CO 2 separation properties over H 2 . However, the CO 2 permeability should be increased for practical applications. Monoethanolamine (MEA) used as a CO 2 determining agent in the current CO 2 capture technology at demonstration scale was readily immobilized in poly(vinyl alcohol) (PVA) matrix by solvent casting of aqueous mixture of PVA and the amine. The resulting polymeric membranes can be self-standing with the thickness above 3 μm and the amine fraction less than 80 wt%. The gas permeation properties were examined at 40 °C and under 80% relative humidity. The CO 2 separation performance increased with increase of the amine content in the polymeric membranes. When the amine fraction was 80 wt%, the CO 2 permeability coefficient of MEA containing membrane was 604 barrer with CO 2 selectivity of 58.5 over H 2 , which was much higher than the PAMAM membrane (83.7 barrer and 51.8, respectively) under the same operation conditions. On the other hand, ethylamine (EA) was also incorporated into PVA matrix to form a thin membrane. However, the resulting polymeric membranes exhibited slight CO 2 -selective gas permeation properties. The hydroxyl group of MEA was crucial for high CO 2 separation performance.

Effect of amine structure on CO2 capture by polymeric membranes

PubMed Central

Taniguchi, Ikuo; Kinugasa, Kae; Toyoda, Mariko; Minezaki, Koki

2017-01-01

Abstract Poly(amidoamine)s (PAMAMs) incorporated into a cross-linked poly(ethylene glycol) exhibited excellent CO2 separation properties over H2. However, the CO2 permeability should be increased for practical applications. Monoethanolamine (MEA) used as a CO2 determining agent in the current CO2 capture technology at demonstration scale was readily immobilized in poly(vinyl alcohol) (PVA) matrix by solvent casting of aqueous mixture of PVA and the amine. The resulting polymeric membranes can be self-standing with the thickness above 3 μm and the amine fraction less than 80 wt%. The gas permeation properties were examined at 40 °C and under 80% relative humidity. The CO2 separation performance increased with increase of the amine content in the polymeric membranes. When the amine fraction was 80 wt%, the CO2 permeability coefficient of MEA containing membrane was 604 barrer with CO2 selectivity of 58.5 over H2, which was much higher than the PAMAM membrane (83.7 barrer and 51.8, respectively) under the same operation conditions. On the other hand, ethylamine (EA) was also incorporated into PVA matrix to form a thin membrane. However, the resulting polymeric membranes exhibited slight CO2-selective gas permeation properties. The hydroxyl group of MEA was crucial for high CO2 separation performance. PMID:29383045

Multivariate regulation of soil CO2 and N2 O pulse emissions from agricultural soils.

PubMed

Liang, Liyin L; Grantz, David A; Jenerette, G Darrel

2016-03-01

Climate and land-use models project increasing occurrence of high temperature and water deficit in both agricultural production systems and terrestrial ecosystems. Episodic soil wetting and subsequent drying may increase the occurrence and magnitude of pulsed biogeochemical activity, affecting carbon (C) and nitrogen (N) cycles and influencing greenhouse gas (GHG) emissions. In this study, we provide the first data to explore the responses of carbon dioxide (CO2 ) and nitrous oxide (N2 O) fluxes to (i) temperature, (ii) soil water content as percent water holding capacity (%WHC), (iii) substrate availability throughout, and (iv) multiple soil drying and rewetting (DW) events. Each of these factors and their interactions exerted effects on GHG emissions over a range of four (CO2 ) and six (N2 O) orders of magnitude. Maximal CO2 and N2 O fluxes were observed in environments combining intermediate %WHC, elevated temperature, and sufficient substrate availability. Amendments of C and N and their interactions significantly affected CO2 and N2 O fluxes and altered their temperature sensitivities (Q10 ) over successive DW cycles. C amendments significantly enhanced CO2 flux, reduced N2 O flux, and decreased the Q10 of both. N amendments had no effect on CO2 flux and increased N2 O flux, while significantly depressing the Q10 for CO2 , and having no effect on the Q10 for N2 O. The dynamics across DW cycles could be attributed to changes in soil microbial communities as the different responses to wetting events in specific group of microorganisms, to the altered substrate availabilities, or to both. The complex interactions among parameters influencing trace gas fluxes should be incorporated into next generation earth system models to improve estimation of GHG emissions. © 2015 John Wiley & Sons Ltd.

Investigation of Desiccants and CO2 Sorbents for Advanced Exploration Systems 2015-2016

NASA Technical Reports Server (NTRS)

Knox, James C.; Watson, David W.; Wingard, Charles D.; West, Phillip W.; Cmarik, Gregory E.; Miller, Lee A.

2016-01-01

Advanced Exploration Systems are integral to crewed missions beyond low earth orbit and beyond the moon. The long-term goal is to reach Mars and return to Earth, but current air revitalization systems are not capable of extended operation within the mass, power, and volume requirements of such a mission. Two primary points are the mechanical stability of sorbent pellets and recovery of sorbent productivity after moisture exposure in the event of a leak. In this paper, we discuss the present efforts towards screening and characterizing commercially-available sorbents for extended operation in desiccant and CO2 removal beds.

Sharing possibilities amongst CDMA Mobile Satellite Systems, and impacts of terminal characteristics on sharing

NASA Astrophysics Data System (ADS)

Bambace, Luís Antonio Waack; Ceballos, Décio Castilho

CDMA Mobile Satellite Systems (CDMA MSS) are able to co-directional, co-frequency and co-coverage sharing, and they are strongly interdependent in case of such a sharing. It is also known that the success of any telecommunication project is the use of the correct media to each task. Operators have a clear sight of such a media adequacy in traditional systems, but not necessarily in the case of Mobile Satellite Systems. This creates a risk that a wrong market objective operator causes trouble to other systems. This paper deals with the sharing alternatives for up to four CDMA MSS operating in the same frequency band, and analysts both: satellite to user downlink and user to satellite uplink. The influence of several items in capacity is here treated. The scope includes: downlink power flux density: code availability; single system internal interference; inter-system interference; diversity schemes: average link impairments, margins; user cooperation; terminal specifications and the dependence of the insulation between RHCP and LHCP with fade.

Mobile satellite services: International co-ordination, co-operation and competition

NASA Technical Reports Server (NTRS)

Lundberg, Olof

1988-01-01

In the context of a discussion of international cooperation, coordination and competition regarding mobile satellite services, it is asserted that: there will be more than one civil mobile satellite service in the 1990's; competition between these separate mobile satellite systems is inevitable; no system should enjoy monopoly protection or subsidies; and coordination and cooperation are desirable and necessary, since the available L-band spectrum is in short supply.

The symbiotic relationship between dominant canopy trees and soil microbes affects the nitrogen source utilization of co-existing understory trees

NASA Astrophysics Data System (ADS)

Iwaoka, C.; Hyodo, F.; Taniguchi, T.; Shi, W.; Du, S.; Yamanaka, N.; Tateno, R.

2017-12-01

The symbiotic relationship between dominant canopy trees and soil microbes such as mycorrhiza or nitrogen (N) fixer are important determinants of soil N dynamics of a forest. However, it is not known how and to what extent the symbiotic relationship of dominant canopy trees with soil microbes affect the N source of co-existing trees in forest. We measured the δ15N of surface soils (0-10 cm), leaves, and roots of the dominant canopy trees and common understory trees in an arbuscular mycorrhizal N-fixing black locust (Robinia pseudoacacia) plantation and an ectomycorrhizal oak (Quercus liaotungensis) natural forest in a China dryland. We also analyzed the soil dissolved N content in soil extracts and absorbed by ion exchange resin, and soil ammonia-oxidizer abundance using real-time PCR. The δ15N of soil and leaves were higher in the black locust forest than in the oak forest, although the δ15N of fine roots was similar in the two forests, in co-existing understory trees as well as dominant canopy trees. Accordingly, the δ15N of leaves was similar to or higher than that of fine roots in the black locust forest, whereas it was consistently lower than that of fine roots in the oak forest. In the black locust forest, the soil dissolved organic N and ammonium N contents were less abundant but the nitrate N contents in soils and absorbed by the ion exchange resin and ammonia-oxidizer abundance were greater, due to N fixation or less uptake of organic N from arbuscular mycorrhiza. In contrast, the soil dissolved organic N and ammonium N contents were more abundant in the oak forest, whereas the N content featured very low nitrate, due to ectomycorrhizal ability to access organic N. These results suggest that the main N source is nitrate N in the black locust forest, but dissolved organic N or ammonium N in the oak forest. N fixation or high N loss due to high N availability would cause high δ15N in soil and leaves in black locust forest. On the other hand, low soil N availability in the oak forest may make 15N fractionation more active in roots via mycorrhizal association, resulting in higher δ15N in fine roots than in leaves. In conclusion, the symbiotic relationship between dominant canopy trees and soil microbes affected the N source of not only the dominant trees but also co-existing understory trees via the control of soil N dynamics.

The Effect of Hydrogen Annealing on the Oxidation Resistance of Four EPM Single Crystal Superalloys

NASA Technical Reports Server (NTRS)

Smialek, James L.; Barrett, Charles A.; Garlick, Ralph G.

2001-01-01

Four single crystal EPM (enabling propulsion materials) developmental airfoil superalloys were hydrogen annealed at 1300 C for up to 100 hours to remove sulfur and improve oxidation resistance. Although the 1100 and 1150 C cyclic oxidation resistance was remarkably improved by annealing for 24 or 100 hours, the behavior was still considerably inferior to that of commercially available single crystal superalloys, especially those that are either Y-doped or hydrogen annealed. Excessive degradation in the developmental alloys appeared to be correlated with low Cr contents and, to a lesser extent, high Co and Re contents.

Inter-genotypic differences in drought tolerance of maritime pine are modified by elevated [CO2].

PubMed

Sánchez-Gómez, David; Mancha, José A; Cervera, M Teresa; Aranda, Ismael

2017-10-17

Despite the importance of growth [CO 2 ] and water availability for tree growth and survival, little information is available on how the interplay of these two factors can shape intraspecific patterns of functional variation in tree species, particularly for conifers. The main objective of the study was to test whether the range of realized drought tolerance within the species can be affected by elevated [CO 2 ]. Intraspecific variability in leaf gas exchange, growth rate and other leaf functional traits were studied in clones of maritime pine. A factorial experiment including water availability, growth [CO 2 ] and four different genotypes was conducted in growth rooms. A 'water deficit' treatment was imposed by applying a cycle of progressive soil water depletion and recovery at two levels of growth [CO 2 ]: 'ambient [CO 2 ]' (aCO 2 400 μmol mol -1 ) and 'elevated [CO 2 ]' (eCO 2 800 μmol mol -1 ). eCO2 had a neutral effect on the impact of drought on growth and leaf gas exchange of the most drought-sensitive genotypes while it aggravated the impact of drought on the most drought-tolerant genotypes at aCO2. Thus, eCO2 attenuated genotypic differences in drought tolerance as compared with those observed at aCO2. Genotypic variation at both levels of growth [CO2] was found in specific leaf area and leaf nitrogen content but not in other physiological leaf traits such as intrinsic water use efficiency and leaf osmotic potential. eCO2 increased Δ 13 C but had no significant effect on δ 18 O. This effect did not interact with the impact of drought, which increased δ 18 O and decreased Δ 13 C. Nevertheless, correlations between Δ 13 C and δ 18 O indicated the non-stomatal component of water use efficiency in this species can be particularly sensitive to drought. Evidence from this study suggests elevated [CO 2 ] can modify current ranges of drought tolerance within tree species. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

The choice: Welding with CO2 or Nd:YAG lasers

NASA Astrophysics Data System (ADS)

Leong, Keng H.

The recent commercial availability of multi-kilowatt Nd:YAG lasers has opened new avenues for rapid laser processing as well as intensified the competition (cost effectiveness) between CO2 and Nd:YAG laser systems. Vendors offering Nd:YAG laser systems may claim lower operating costs (than CO2) and fiberoptic beam delivery flexibility while CO2 systems vendors may emphasize lower capital cost and well established processing requirements and experience. The capital and operating costs of a laser system are impacted by demand and supply economics and technological advances. Frequently the total cost of a workcell using a laser for processing has to be considered rather than the laser system alone. Consequently it is not very practical to approach the selection of a laser system based on its capital cost and estimated operating cost only. This presentation describes a more pragmatic approach to aid the user in the selection of the optimal multi-kilowatt laser system for a particular processing requirement with emphasis on welding. CO2 laser systems are well established on the factory floor. Consequently, emphasis is given to the comparative application of Nd:YAG lasers, process requirements and performance. Requirements for the laser welding of different metals are examined in the context of hardware (laser system and beam delivery) selection and examples of welding speeds that can be achieved using CO2 and Nd:YAG lasers are examined.

A Small Decrease in Rubisco Content by Individual Suppression of RBCS Genes Leads to Improvement of Photosynthesis and Greater Biomass Production in Rice Under Conditions of Elevated CO2.

PubMed

Kanno, Keiichi; Suzuki, Yuji; Makino, Amane

2017-03-01

Rubisco limits photosynthesis at low CO2 concentrations ([CO2]), but does not limit it at elevated [CO2]. This means that the amount of Rubisco is excessive for photosynthesis at elevated [CO2]. Therefore, we examined whether a small decrease in Rubisco content by individual suppression of the RBCS multigene family leads to increases in photosynthesis and biomass production at elevated [CO2] in rice (Oryza sativa L.). Our previous studies indicated that the individual suppression of RBCS decreased Rubisco content in rice by 10-25%. Three lines of BC2F2 progeny were selected from transgenic plants with individual suppression of OsRBCS2, 3 and 5. Rubisco content in the selected lines was 71-90% that of wild-type plants. These three transgenic lines showed lower rates of CO2 assimilation at low [CO2] (28 Pa) but higher rates of CO2 assimilation at elevated [CO2] (120 Pa). Similarly, the biomass production and relative growth rate (RGR) of the two lines were also smaller at low [CO2] but greater than that of wild-type plants at elevated [CO2]. This greater RGR was caused by the higher net assimilation rate (NAR). When the nitrogen use efficiency (NUE) for the NAR was estimated by dividing the NAR by whole-plant leaf N content, the NUE for NAR at elevated [CO2] was higher in these two lines. Thus, a small decrease in Rubisco content leads to improvements of photosynthesis and greater biomass production in rice under conditions of elevated CO2. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Correlation of Amine Swingbed On-Orbit CO2 Performance with a Hardware Independent Predictive Model

NASA Technical Reports Server (NTRS)

Papale, William; Sweterlitsch, Jeffery

2015-01-01

The Amine Swingbed Payload is an experimental system deployed on the International Space Station (ISS) that includes a two-bed, vacuum regenerated, amine-based carbon dioxide (CO2) removal subsystem as the principal item under investigation. The aminebased subsystem, also described previously in various publications as CAMRAS 3, was originally designed, fabricated and tested by Hamilton Sundstrand Space Systems International, Inc. (HSSSI) and delivered to NASA in November 2008. The CAMRAS 3 unit was subsequently designed into a flight payload experiment in 2010 and 2011, with flight test integration activities accomplished on-orbit between January 2012 and March 2013. Payload activation was accomplished in May 2013 followed by a 1000 hour experimental period. The experimental nature of the Payload and the interaction with the dynamic ISS environment present unique scientific and engineering challenges, in particular to the verification and validation of the expected Payload CO2 removal performance. A modeling and simulation approach that incorporates principles of chemical reaction engineering has been developed for the amine-based system to predict the dynamic cabin CO2 partial pressure with given inputs of sorbent bed size, process air flow, operating temperature, half-cycle time, CO2 generation rate, cabin volume and the magnitude of vacuum available. Simulation runs using the model to predict ambient CO2 concentrations show good correlation to on-orbit performance measurements and ISS dynamic concentrations for the assumed operating conditions. The dynamic predictive modelling could benefit operational planning to help ensure ISS CO2 concentrations are maintained below prescribed limits and for the Orion vehicle to simulate various operating conditions, scenarios and transients.

Nitrogen Availability Dampens the Positive Impacts of CO2 Fertilization on Terrestrial Ecosystem Carbon and Water Cycles

NASA Astrophysics Data System (ADS)

He, Liming; Chen, Jing M.; Croft, Holly; Gonsamo, Alemu; Luo, Xiangzhong; Liu, Jane; Zheng, Ting; Liu, Ronggao; Liu, Yang

2017-11-01

The magnitude and variability of the terrestrial CO2 sink remain uncertain, partly due to limited global information on ecosystem nitrogen (N) and its cycle. Without N constraint in ecosystem models, the simulated benefits from CO2 fertilization and CO2-induced increases in water use efficiency (WUE) may be overestimated. In this study, satellite observations of a relative measure of chlorophyll content are used as a proxy for leaf photosynthetic N content globally for 2003-2011. Global gross primary productivity (GPP) and evapotranspiration are estimated under elevated CO2 and N-constrained model scenarios. Results suggest that the rate of global GPP increase is overestimated by 85% during 2000-2015 without N limitation. This limitation is found to occur in many tropical and boreal forests, where a negative leaf N trend indicates a reduction in photosynthetic capacity, thereby suppressing the positive vegetation response to enhanced CO2 fertilization. Based on our carbon-water coupled simulations, enhanced CO2 concentration decreased stomatal conductance and hence increased WUE by 10% globally over the 1982 to 2015 time frame. Due to increased anthropogenic N application, GPP in croplands continues to grow and offset the weak negative trend in forests due to N limitation. Our results also show that the improved WUE is unlikely to ease regional droughts in croplands because of increases in evapotranspiration, which are associated with the enhanced GPP. Although the N limitation on GPP increase is large, its associated confidence interval is still wide, suggesting an urgent need for better understanding and quantification of N limitation from satellite observations.

Novel process and catalytic materials for converting CO2 and H2 containing mixtures to liquid fuels and chemicals.

PubMed

Meiri, Nora; Dinburg, Yakov; Amoyal, Meital; Koukouliev, Viatcheslav; Nehemya, Roxana Vidruk; Landau, Miron V; Herskowitz, Moti

2015-01-01

Carbon dioxide and water are renewable and the most abundant feedstocks for the production of chemicals and fungible fuels. However, the current technologies for production of hydrogen from water are not competitive. Therefore, reacting carbon dioxide with hydrogen is not economically viable in the near future. Other alternatives include natural gas, biogas or biomass for the production of carbon dioxide, hydrogen and carbon monoxide mixtures that react to yield chemicals and fungible fuels. The latter process requires a high performance catalyst that enhances the reverse water-gas-shift (RWGS) reaction and Fischer-Tropsch synthesis (FTS) to higher hydrocarbons combined with an optimal reactor system. Important aspects of a novel catalyst, based on a Fe spinel and three-reactor system developed for this purpose published in our recent paper and patent, were investigated in this study. Potassium was found to be a key promoter that improves the reaction rates of the RWGS and FTS and increases the selectivity of higher hydrocarbons while producing mostly olefins. It changed the texture of the catalyst, stabilized the Fe-Al-O spinel, thus preventing decomposition into Fe3O4 and Al2O3. Potassium also increased the content of Fe5C2 while shifting Fe in the oxide and carbide phases to a more reduced state. In addition, it increased the relative exposure of carbide iron on the catalysts surface, the CO2 adsorption and the adsorption strength. A detailed kinetic model of the RWGS, FTS and methanation reactions was developed for the Fe spinel catalyst based on extensive experimental data measured over a range of operating conditions. Significant oligomerization activity of the catalyst was found. Testing the pelletized catalyst with CO2, CO and H2 mixtures over a range of operating conditions demonstrated its high productivity to higher hydrocarbons. The composition of the liquid (C5+) was found to be a function of the potassium content and the composition of the feedstock.

Whole-plant growth and N utilization in transgenic rice plants with increased or decreased Rubisco content under different CO2 partial pressures.

PubMed

Sudo, Emi; Suzuki, Yuji; Makino, Amane

2014-11-01

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) strongly limits photosynthesis at lower CO2 concentration [CO2] whereas [corrected] Rubisco limitation is cancelled by elevated [CO2]. Therefore, increase or reduction in Rubisco content by transformation with a sense or an antisense RBCS construct are expected to alter the biomass production under different CO2 levels. RBCS-sense (125% Rubisco of wild-type) and -antisense (35% Rubisco of wild-type) rice (Oryza sativa L.) plants were grown for 63 days at three different CO2 levels: low [CO2] (28 Pa), normal [CO2] (40 Pa) and elevated [CO2] (120 Pa). The biomass of RBCS-sense plants was 32% and 15% greater at low [CO2] and normal [CO2] than that of the wild-type plants, respectively, but did not differ at elevated [CO2]. Conversely, the biomass of RBCS-antisense plants was the smallest at low [CO2]. Thus, overproduction of Rubisco was effective for biomass production at low [CO2]. Greater biomass production at low [CO2] in RBCS-sense plants was caused by an increase in the net assimilation rate, and associated with an increase in the amount of N uptake. Furthermore, Rubisco overproduction in RBCS-sense plants was also promoted at low [CO2]. Although it seems that low [CO2]-growth additionally stimulates the effect of RBCS overexpression, such a phenomenon observed at low [CO2] was mediated through an increase in total leaf N content. Thus, the dependence of the growth improvement in RBCS-sense rice on growth [CO2] was closely related to the degree of Rubisco overproduction which was accompanied not only by leaf N content but also by whole plant N content. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Analysis of electric power industry restructuring

NASA Astrophysics Data System (ADS)

Al-Agtash, Salem Yahya

1998-10-01

This thesis evaluates alternative structures of the electric power industry in a competitive environment. One structure is based on the principle of creating a mandatory power pool to foster competition and manage system economics. The structure is PoolCo (pool coordination). A second structure is based on the principle of allowing independent multilateral trading and decentralized market coordination. The structure is DecCo (decentralized coordination). The criteria I use to evaluate these two structures are: economic efficiency, system reliability and freedom of choice. Economic efficiency evaluation considers strategic behavior of individual generators as well as behavioral variations of different classes of consumers. A supply-function equilibria model is characterized for deriving bidding strategies of competing generators under PoolCo. It is shown that asymmetric equilibria can exist within the capacities of generators. An augmented Lagrangian approach is introduced to solve iteratively for global optimal operations schedules. Under DecCo, the process involves solving iteratively for system operations schedules. The schedules reflect generators strategic behavior and brokers' interactions for arranging profitable trades, allocating losses and managing network congestion. In the determination of PoolCo and DecCo operations schedules, overall costs of power generation (start-up and shut-down costs and availability of hydro electric power) as well as losses and costs of transmission network are considered. For system reliability evaluation, I examine the effect of PoolCo and DecCo operating conditions on the system security. Random component failure perturbations are generated to simulate the actual system behavior. This is done using Monte Carlo simulation. Freedom of choice evaluation accounts for schemes' beneficial opportunities and capabilities to respond to consumers expressed preferences. An IEEE 24-bus test system is used to illustrate the concepts developed for economic efficiency evaluation. The system was tested over two years time period. The results indicate 2.6684 and 2.7269 percent of efficiency loss on average for PoolCo and DecCo, respectively. These values, however, do not represent forecasts of efficiency losses of PoolCo- and DecCo-based competitive industries. Rather, they are illustrations of the efficiency losses for the given IEEE test system and based on the modeling assumptions underlying framework development.

Does elevated CO2 ameliorate the impact of O3 on chlorophyll content and photosynthesis in potato (Solanum tuberosum)?

PubMed

Donnelly, Alison; Craigon, Jim; Black, Colin R.; Colls, Jeremy J.; Landon, Geoff

2001-04-01

This study examined the impact of season-long exposure to elevated carbon dioxide (CO2) and ozone (O3), individually and in combination, on leaf chlorophyll content and gas exchange characteristics in potato (Solanum tuberosum L. cv. Bintje). Plants grown in open-top chambers were exposed to three CO2 (ambient, 550 and 680 µmol mol-1) and two O3 treatments (ambient and elevated; 25 and 65 nmol mol-1, 8 h day-1 means, respectively) between crop emergence and maturity; plants were also grown in unchambered field plots. Non-destructive measurements of chlorophyll content and visible foliar injury were made for all treatments at 2-week intervals between 43 and 95 days after emergence. Gas exchange measurements were made for all except the intermediate 550 µmol mol-1 CO2 treatment. Season-long exposure to elevated O3 under ambient CO2 reduced chlorophyll content and induced extensive visible foliar damage, but had little effect on net assimilation rate or stomatal conductance. Elevated CO2 had no significant effect on chlorophyll content, but greatly reduced the damaging impact of O3 on chlorophyll content and visible foliar damage. Light-saturated assimilation rates for leaves grown under elevated CO2 were consistently lower when measured under either elevated or ambient CO2 than in equivalent leaves grown under ambient CO2. Analysis of CO2 response curves revealed that CO2-saturated assimilation rate, maximum rates of carboxylation and electron transport and respiration decreased with time. CO2-saturated assimilation rate was reduced by elevated O3 during the early stages of the season, while respiration was significantly greater under elevated CO2 as the crop approached maturity. The physiological origins of these responses and their implications for the performance of potato in a changing climate are discussed.

Mantle to surface degassing of carbon- and sulphur-rich alkaline magma at El Hierro, Canary Islands

NASA Astrophysics Data System (ADS)

Longpré, Marc-Antoine; Stix, John; Klügel, Andreas; Shimizu, Nobumichi

2017-02-01

Basaltic volcanoes transfer volatiles from the mantle to the surface of the Earth. The quantification of deep volatile fluxes relies heavily on estimates of the volatile content of primitive magmas, the best archive of which is provided by melt inclusions. Available data from volcanoes producing mafic alkaline lavas in a range of tectonic settings suggest high volatile fluxes, but information remains sparse, particularly for intraplate ocean islands. Here we present measurements of volatile and trace element concentrations, as well as sulphur speciation, in olivine-hosted melt inclusions and matrix glasses from quenched basanite lava balloon samples from the 2011-2012 submarine eruption at El Hierro, Canary Islands. The results reveal remarkably high concentrations of dissolved volatiles and incompatible trace elements in this magma, with ∼80 ppm Nb and up to 3420 ppm CO2, 3.0 wt.% H2O and 5080 ppm S. Reconstructed primitive CO2 contents, considering CO2/Nb systematics and possible CO2 sequestration in shrinkage bubbles, reach weight percent levels, indicating that carbon is a major constituent of Canary Island magmas at depth and that exsolution of a CO2-rich fluid begins in the mantle at pressures in excess of 1 GPa. Correlations between sulphur concentration, sulphur speciation and water content suggest strong reduction of an initially oxidised mantle magma, likely controlled by coupled H2O and S degassing. This late-stage redox change may have triggered sulphide saturation, recorded by globular sulphide inclusions in clinopyroxene and ulvöspinel. The El Hierro basanite thus had a particularly high volatile-carrying capacity and released a minimum of 1.3-2.1 Tg CO2 and 1.8-2.9 Tg S to the environment, causing substantial stress on the local submarine ecosystem. These results highlight the important contribution of alkaline ocean island volcanoes, such as the Canary Islands, to volatile fluxes from the mantle.

Depth-dependence and monthly variability of charophyte biomass production: consequences for the precipitation of calcium carbonate in a shallow Chara-lake.

PubMed

Pukacz, Andrzej; Pełechaty, Mariusz; Frankowski, Marcin

2016-11-01

The month-to-month variability of biomass and CaCO 3 precipitation by dense charophyte beds was studied in a shallow Chara-lake at two depths, 1 and 3 m. Charophyte dry weights (d.w.), the percentage contribution of calcium carbonate to the dry weight and the precipitation of CaCO 3 per 1 m 2 were analysed from May to October 2011. Physical-chemical parameters of water were also measured for the same sample locations. The mean dry weight and calcium carbonate precipitation were significantly higher at 1 m than at 3 m. The highest measured charophyte dry weight (exceeding 2000 g m -2 ) was noted at 1 m depth in September, and the highest CaCO 3 content in the d.w. (exceeding 80 % of d.w.) was observed at 3 m depth in August. The highest CaCO 3 precipitation per 1 m 2 exceeded 1695 g at 1 m depth in August. Significant differences in photosynthetically active radiation (PAR) were found between 1 and 3 m depths; there were no significant differences between depths for other water properties. At both sampling depths, there were distinct correlations between the d.w., CaCO 3 content and precipitation and water properties. In addition to PAR, the water temperature and magnesium and calcium ion concentrations were among the most significant determinants of CaCO 3 content and d.w. The results show that light availability seems to be the major factor in determining charophyte biomass in a typical, undisturbed Chara-lake. The study results are discussed in light of the role of charophyte vegetation in whole ecosystem functioning, with a particular focus on sedimentary processes and the biogeochemical cycle within the littoral zone.

Co-digestion of agricultural and municipal waste to produce energy and soil amendment.

PubMed

Macias-Corral, Maritza A; Samani, Zohrab A; Hanson, Adrian T; Funk, Paul A

2017-09-01

In agriculture, manure and cotton gin waste are major environmental liabilities. Likewise, grass is an important organic component of municipal waste. These wastes were combined and used as substrates in a two-phase, pilot-scale anaerobic digester to evaluate the potential for biogas (methane) production, waste minimisation, and the digestate value as soil amendment. The anaerobic digestion process did not show signs of inhibition. Biogas production increased during the first 2 weeks of operation, when chemical oxygen demand and volatile fatty acid concentrations and the organic loading rate to the system were high. Chemical oxygen demand from the anaerobic columns remained relatively steady after the first week of operation, even at high organic loading rates. The experiment lasted about 1 month and produced 96.5 m 3 of biogas (68 m 3 of CH 4 ) per tonne of waste. In terms of chemical oxygen demand to methane conversion efficiency, the system generated 62% of the theoretical methane production; the chemical oxygen demand/volatile solids degradation rate was 62%, compared with the theoretical 66%. The results showed that co-digestion and subsequent digestate composting resulted in about 60% and 75% mass and volume reductions, respectively. Digestate analysis showed that it can be used as a high nutrient content soil amendment. The digestate met Class A faecal coliform standards (highest quality) established in the United States for biosolids. Digestion and subsequent composting concentrated the digestate nitrogen, phosphorus, and potassium content by 37%, 24%, and 317%, respectively. Multi-substrate co-digestion is a practical alternative for agricultural waste management, minimisation of landfill disposal, and it also results in the production of valuable products.

SUBTASK 2.19 – OPERATIONAL FLEXIBILITY OF CO2 TRANSPORT AND STORAGE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, Melanie; Schlasner, Steven; Sorensen, James

2014-12-31

Carbon dioxide (CO2) is produced in large quantities during electricity generation and by industrial processes. These CO2 streams vary in terms of both composition and mass flow rate, sometimes substantially. The impact of a varying CO2 stream on pipeline and storage operation is not fully understood in terms of either operability or infrastructure robustness. This study was performed to summarize basic background from the literature on the topic of operational flexibility of CO2 transport and storage, but the primary focus was on compiling real-world lessons learned about flexible operation of CO2 pipelines and storage from both large-scale field demonstrations andmore » commercial operating experience. Modeling and pilot-scale results of research in this area were included to illustrate some of the questions that exist relative to operation of carbon capture and storage (CCS) projects with variable CO2 streams. It is hoped that this report’s real-world findings provide readers with useful information on the topic of transport and storage of variable CO2 streams. The real-world results were obtained from two sources. The first source consisted of five full-scale, commercial transport–storage projects: Sleipner, Snøhvit, In Salah, Weyburn, and Illinois Basin–Decatur. These scenarios were reviewed to determine the information that is available about CO2 stream variability/intermittency on these demonstration-scale projects. The five projects all experienced mass flow variability or an interruption in flow. In each case, pipeline and/or injection engineers were able to accommodate any issues that arose. Significant variability in composition has not been an issue at these five sites. The second source of real- world results was telephone interviews conducted with experts in CO2 pipeline transport, injection, and storage during which commercial anecdotal information was acquired to augment that found during the literature search of the five full-scale projects. The experts represented a range of disciplines and hailed from North America and Europe. Major findings of the study are that compression and transport of CO2 for enhanced oil recovery (EOR) purposes in the United States has shown that impurities are not likely to cause transport problems if CO2 stream composition standards are maintained and pressures are kept at 10.3 MPa or higher. Cyclic, or otherwise intermittent, CO2 supplies historically have not impacted in-field distribution pipeline networks, wellbore integrity, or reservoir conditions. The U.S. EOR industry has demonstrated that it is possible to adapt to variability and intermittency in CO2 supply through flexible operation of the pipeline and geologic storage facility. This CO2 transport and injection experience represents knowledge that can be applied in future CCS projects. A number of gaps in knowledge were identified that may benefit from future research and development, further enhancing the possibility for widespread application of CCS. This project was funded through the Energy & Environmental Research Center–U.S. Department of Energy Joint Program on Research and Development for Fossil Energy-Related Resources Cooperative Agreement No. DE-FC26-08NT43291. Nonfederal funding was provided by the IEA Greenhouse Gas R&D Programme.« less

Electroplated Fe-Co-Ni films prepared in ammonium-chloride-based plating baths

NASA Astrophysics Data System (ADS)

Yanai, T.; Koda, K.; Kaji, J.; Aramaki, H.; Eguchi, K.; Takashima, K.; Nakano, M.; Fukunaga, H.

2018-05-01

We electroplated Fe-Co-Ni films in ammonium-chloride-based plating baths, and investigated the effect of the Co content on the magnetic properties and the structural ones of the as-plated films. The coercivity increased abruptly when the Co content become more than 60 at.%. As the rough surfaces were observed in the high Co content region, we considered that degradation of the surface is a factor of the abrupt increase in the coercivity. From the XRD analysis, we found that another factor of the abrupt increase is fcc-bcc phase transformation, and concluded that we need to keep the fcc structure to obtain Fe-Co-Ni films with low coercivity.

Measuring priming using 14C of respired CO2: effects on respiration source pools and interactions with warming

NASA Astrophysics Data System (ADS)

Hopkins, F. M.; Trumbore, S.

2011-12-01

The role of substrate availability on soil carbon turnover is a critical unknown in predicting future soil carbon stocks. Substrate composition and availability can be altered by land cover change, warming, and nitrogen deposition, which can in turn affect soil carbon stocks through the priming effect. In particular, little is understood about the interaction between warming and changing substrate concentration. We examined the interactions between global change factors and the priming effect using sucrose addition to incubations of soils from two forest Free Air CO2 Enrichment (FACE) sites (Duke and Aspen). In addition to the in situ global change manipulations conducted at these sites, the CO2 fertilization procedure over the decade-long experiment labeled soil carbon pools with fossil-derived carbon (depleted in 14C relative to the background isotope content of soil carbon), allowing us to determine the effect of priming on respiration of soil carbon substrates of different ages. Thus, we used the carbon-13 signature of sucrose-derived CO2 to account for losses of substrate C, and the carbon-14 signature to partition fluxes of soil-derived CO2 between pre-FACE (> 10 y) and FACE derived (< 10 y) carbon sources. At both sites, we observed a positive priming effect-an increase in the rate of soil carbon derived respiration due to sucrose addition. However, the effect of substrate addition on respiratory source pools, as measured by 14C of respiration, varied greatly. At Duke FACE, we observed an increase in 14C content of CO2 of primed soil carbon, whereas at Aspen, we observed no difference. The amount of CO2 released by priming increased with temperature, but was proportionally similar to the amount of increase in basal respiration rates (no differences in Q10). At Duke, both warming and priming served to increase the 14C of respiration, whereas only warming changed 14C of respiration at Aspen. Despite similar overall carbon stocks, differences in the source of the priming effect between the two sites may be due to inherent differences in the relative role of stabilization factors within the soil carbon stock.

Characterizing the changes in biopolymer composition in roots of photosynthetically divergent grasses exposed to future climates

NASA Astrophysics Data System (ADS)

Suseela, V.; Tharayil, N.; Pendall, E.

2014-12-01

A majority of carbon in soil is derived from plant roots, yet roots remain remarkably less explored. Root tissues are abundant in heteropolymers such as suberin, lignin and tannins which are energetically demanding to depolymerize, thus facilitating the accrual of carbon in soil. Most biopolymers are operationally/functionally defined and their function is regulated by the identity of monomers and the linkages connecting these monomers. The structural chemistry of these biopolymers could vary with the environmental conditions experienced during their formative stage thus altering the potential for soil carbon sequestration. We examined the biopolymer composition in the roots of a C3 (Hesperostipa comata) and a C4 (Bouteloua gracilis) grass species exposed to a factorial combination of warming and elevated CO2 at the Prairie Heating and CO2 Enrichment (PHACE) experiment, Wyoming, USA. The grass roots were subjected to a sequential solvent extraction and base hydrolysis to delineate various operational fractions within the polydisperse matrix. The extracted fractions were analyzed using various chromatography mass spectrometry platforms. Warming and elevated CO2 increased the total suberin content and the amount of ω-hydroxy acids in C4 grass species while in C3 species there was a trend of increasing concentration of α,ω-dioic acids in roots exposed to elevated CO2 compared to ambient CO2 treatment. Our results highlight the effect of warming and elevated CO2 on the chemical composition of heteropolymers in roots that may potentially alter root function and rate of decomposition leading to changes in soil carbon in a future warmer world.

Speciation, behaviour, and fate of mercury under oxy-fuel combustion conditions.

PubMed

Córdoba, Patricia; Maroto-Valer, M; Delgado, Miguel Angel; Diego, Ruth; Font, Oriol; Querol, Xavier

2016-02-01

The work presented here reports the first study in which the speciation, behaviour and fate of mercury (Hg) have been evaluated under oxy-fuel combustion at the largest oxy-Pulverised Coal Combustion (oxy-PCC) demonstration plant to date during routine operating conditions and partial exhaust flue gas re-circulation to the boiler. The effect of the CO2-rich flue gas re-circulation on Hg has also been evaluated. Results reveal that oxy-PCC operational conditions play a significant role on Hg partitioning and fate because of the continuous CO2-rich flue gas re-circulations to the boiler. Mercury escapes from the cyclone in a gaseous form as Hg(2+) (68%) and it is the prevalent form in the CO2-rich exhaust flue gas (99%) with lower proportions of Hg(0) (1.3%). The overall retention rate for gaseous Hg is around 12%; Hg(0) is more prone to be retained (95%) while Hg(2+) shows a negative efficiency capture for the whole installation. The negative Hg(2+) capture efficiencies are due to the continuous CO2-rich exhaust flue gas recirculation to the boiler with enhanced Hg contents. Calculations revealed that 44mg of Hg were re-circulated to the boiler as a result of 2183 re-circulations of CO2-rich flue gas. Especial attention must be paid to the role of the CO2-rich exhaust flue gas re-circulation to the boiler on the Hg enrichment in Fly Ashes (FAs). Copyright © 2015 Elsevier Inc. All rights reserved.

Co-pyrolysis behavior of microalgae biomass and low-quality coal: Products distributions, char-surface morphology, and synergistic effects.

PubMed

Wu, Zhiqiang; Yang, Wangcai; Li, Yaowu; Yang, Bolun

2018-05-01

In this work, the distributions and releasing properties of the primary volatile products during co-pyrolysis of low-rank coal and green algae (GA) has been studied using fixed-bed reactor with online mass spectrometry. Surface morphology of the char was described quantitatively by SEM combined with fractal theory. Different forms of synergistic effects existed from both the yields of products and composition of the main gaseous products. Positive synergistic effects from tar yield were observed under 25% of GA from 600 to 850 °C, indicating GA promoted the formation of tar. Opposite synergistic effects on the content of H 2 and CO were gained when the mass ratio of GA was 50%. The fractal dimensions of co-pyrolysis char were less than the calculated values except under 650 °C, which meant the GA promoted the homogeneity of char surface. This work could provide essential data for proper operation parameters selecting for co-pyrolysis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Integrating Satellite Measurements from Polar-orbiting instruments into Smoke Disperson Forecasts

NASA Astrophysics Data System (ADS)

Smith, N.; Pierce, R. B.; Barnet, C.; Gambacorta, A.; Davies, J. E.; Strabala, K.

2015-12-01

The IDEA-I (Infusion of Satellite Data into Environmental Applications-International) is a real-time system that currently generates trajectory-based forecasts of aerosol dispersion and stratospheric intrusions. Here we demonstrate new capabilities that use satellite measurements from the Joint Polar Satellite System (JPSS) Suomi-NPP (S-NPP) instruments (operational since 2012) in the generation of trajectory-based predictions of smoke dispersion from North American wildfires. Two such data products are used, namely the Visible Infrared Imaging Radiometer Suite (VIIRS) Aerosol Optical Depth (AOD) and the combined Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) NOAA-Unique CrIS-ATMS Processing System (NUCAPS) carbon monoxide (CO) retrievals. The latter is a new data product made possible by the release of full spectral-resolution CrIS measurements since December 2014. Once NUCAPS CO becomes operationally available it will be used in real-time applications such as IDEA-I along with VIIRS AOD and meteorological forecast fields to support National Weather Service (NWS) Incident Meteorologist (IMET) and air quality management decision making. By combining different measurements, the information content of the IDEA-I transport and dispersion forecast is improved within the complex terrain features that dominate the Western US and Alaska. The primary user community of smoke forecasts is the Western regions of the National Weather Service (NWS) and US Environmental Protection Agency (EPA) due to the significant impacts of wildfires in these regions. With this we demonstrate the quality of the smoke dispersion forecasts that can be achieved by integrating polar-orbiting satellite measurements with forecast models to enable on-site decision support services for fire incident management teams and other real-time air quality agencies.

Cation distribution effect on static and dynamic magnetic properties of Co1-xZnxFe2O4 ferrite powders

NASA Astrophysics Data System (ADS)

Barrera, G.; Coisson, M.; Celegato, F.; Raghuvanshi, S.; Mazaleyrat, F.; Kane, S. N.; Tiberto, P.

2018-06-01

Co1-xZnxFe2O4 (0.08 ≤ x ≤ 0.56) powders prepared by a sol-gel auto-combustion method have been investigated through the combined use of structural and dc/ac-magnetization measurements under a wide range of applied magnetic field values. EDS spectra are performed to evaluate the samples chemical composition, whereas the X-ray diffraction measurements indicate the formation of the typical nanocrystalline mixed cubic spinel structure and allow to determine the cationic distribution as well as the lattice parameter and the oxygen position as function of Zn content. Magnetic characterization improves the knowledge about the correlation between the structural properties and magnetic behavior. The magnetization curves show a hysteretic behavior at room temperature and they are analyzed as function of Zn content taking in account the Yafet-Kittel's model. The replacement of non-zero magnetic moment Co2+ ions with zero magnetic moment Zn2+ ions induces a gradual reduction of magnetocrystalline anisotropy and a lowering of the magnetic coercivity. The energy lost in a static and alternating magnetic field (frequency of 69 kHz) at selected vertex field values for the studied samples has been calculated in order to evaluate their prospective usage to operate in different field conditions.

A novel once-daily fixed-dose combination of memantine extended release and donepezil for the treatment of moderate to severe Alzheimer's disease: two phase I studies in healthy volunteers.

PubMed

Boinpally, Ramesh; Chen, Laishun; Zukin, Stephen R; McClure, Natalie; Hofbauer, Robert K; Periclou, Antonia

2015-07-01

Combining two standard-of-care medications for Alzheimer's disease (AD) into a single once-daily dosage unit may improve treatment adherence, facilitate drug administration, and reduce caregiver burden. A new fixed-dose combination (FDC) capsule containing 28 mg memantine extended release (ER) and 10 mg donepezil was evaluated for bioequivalence with co-administered commercially available memantine ER and donepezil, and for bioavailability with regard to food intake. Two phase I, single-dose, randomized, open-label, crossover studies were conducted in 18- to 45-year-old healthy individuals. In MDX-PK-104 study, fasting participants (N = 38) received co-administered memantine ER and donepezil or the FDC. In MDX-PK-105 study, participants (N = 36) received three treatments: intact FDC taken while fasting or after a high-fat meal, or FDC contents sprinkled on applesauce while fasting. Standard pharmacokinetic parameters for memantine and donepezil were calculated from the plasma concentration time-curve using non-compartmental analyses. Linear mixed-effects models were used to compare: (a) FDC versus co-administered individual drugs; (b) FDC fasted versus with food; and (c) FDC sprinkled on applesauce versus FDC intact, both fasted. Safety parameters were also evaluated. The FDC capsule was bioequivalent to co-administered memantine ER and donepezil. There was no significant food effect on the bioavailability of the FDC components. There were no clinically relevant differences in time to maximum plasma concentration or safety profiles across treatments. An FDC capsule containing 28 mg memantine ER and 10 mg donepezil is bioequivalent to commercially available memantine ER and donepezil, and bioavailability is not affected by food intake or sprinkling of capsule contents on applesauce.

Large net CO2 loss from a grass-dominated tropical savanna in south-central Brazil in response to seasonal and interannual drought

NASA Astrophysics Data System (ADS)

Zanella De Arruda, Paulo Henrique; Vourlitis, George Louis; Santanna, Franciele Bomfiglio; Pinto, Osvaldo Borges, Jr.; De Almeida Lobo, Francisco; De Souza Nogueira, José

2016-08-01

The savanna vegetation of Brazil (Cerrado) accounts for 20-25% of the land cover of Brazil and is the second largest ecosystem following Amazonian forest; however, Cerrado mass and energy exchange is still highly uncertain. We used eddy covariance to measure the net ecosystem CO2 exchange (NEE) of grass-dominated Cerrado (campo sujo) over 3 years. We hypothesized that soil water availability would be a key control over the seasonal and interannual variations in NEE. Multiple regression indicated that gross primary production (GPP) was positively correlated (Pearson's r = 0.69; p < 0.001) with soil water content, radiation, and the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived enhanced vegetation index (EVI) but negatively correlated with the vapor pressure deficit (VPD), indicating that drier conditions increased water limitations on GPP. Similarly, ecosystem respiration (Reco) was positively correlated (Pearson's r = 0.78; p < 0.001) with the EVI, radiation, soil water content, and temperature but slightly negatively correlated with rainfall and the VPD. While the NEE responded rapidly to temporal variations in soil water availability, the grass-dominated Cerrado stand was a net source of CO2 to the atmosphere during the study period, which was drier compared to the long-term average rainfall. Cumulative NEE was approximately 842 gC m-2, varying from 357 gC m-2 in 2011 to 242 gC m-2 in 2012. Our results indicate that grass-dominated Cerrado may be an important regional CO2 source in response to the warming and drying that is expected to occur in the southern Amazon Basin under climate change.

Highly CO2-Selective Gas Separation Membranes Based on Segmented Copolymers of Poly(Ethylene oxide) Reinforced with Pentiptycene-Containing Polyimide Hard Segments.

PubMed

Luo, Shuangjiang; Stevens, Kevin A; Park, Jae Sung; Moon, Joshua D; Liu, Qiang; Freeman, Benny D; Guo, Ruilan

2016-01-27

Poly(ethylene oxide) (PEO)-containing polymer membranes are attractive for CO2-related gas separations due to their high selectivity toward CO2. However, the development of PEO-rich membranes is frequently challenged by weak mechanical properties and a high crystallization tendency of PEO that hinders gas transport. Here we report a new series of highly CO2-selective, amorphous PEO-containing segmented copolymers prepared from commercial Jeffamine polyetheramines and pentiptycene-based polyimide. The copolymers are much more mechanically robust than the nonpentiptycene containing counterparts due to the molecular reinforcement mechanism of supramolecular chain threading and interlocking interactions induced by the pentiptycene structures, which also effectively suppresses PEO crystallization leading to a completely amorphous structure even at 60% PEO weight content. Membrane transport properties are sensitively affected by both PEO weight content and PEO chain length. A nonlinear correlation between CO2 permeability with PEO weight content was observed due to the competition between solubility and diffusivity contributions, whereby the copolymers change from being size-selective to solubility-selective when PEO content reaches 40%. CO2 selectivities over H2 and N2 increase monotonically with both PEO content and chain length, indicating strong CO2-philicity of the copolymers. The copolymer film with the longest PEO sequence (PEO2000) and highest PEO weight content (60%) showed a measured CO2 pure gas permeability of 39 Barrer, and ideal CO2/H2 and CO2/N2 selectivities of 4.1 and 46, respectively, at 35 °C and 3 atm, making them attractive for hydrogen purification and carbon capture.

Gross primary production of a semiarid grassland is enhanced by six years of exposure to elevated atmospheric CO2, warming, and irrigation.

NASA Astrophysics Data System (ADS)

Ryan, E.; Ogle, K.; Peltier, D.; Williams, D. G.; Pendall, E.

2014-12-01

The goal of this study was to quantify interannual variation of gross primary production (GPP) and evaluate potential drivers of GPP with global change using the Prairie Heating and CO2 Enrichment (PHACE) experiment in semiarid grassland in southeastern Wyoming. PHACE consists of the treatments: control, warming only, elevated CO2 (eCO2) only, eCO2 and warming, and irrigation only. We expected that GPP would be most strongly influenced by interannual variability in precipitation under all PHACE treatments, soil water availability under eCO2, and nitrogen availability. GPP data were obtained from paired measurements of net ecosystem exchange (NEE) and ecosystem respiration (Reco; GPP = Reco - NEE) made on 2-4 week intervals over six growing seasons (2007-2012). Soil temperature (T), soil water content (SWC), vapor pressure deficit (VPD), and photosynthetically active radiation (PAR) were continuously recorded at the plot (T, SWC) and site (VPD, PAR) scales. Annual, plot-level aboveground plant nitrogen content (N) was measured during peak biomass. We fit a non-linear light-response model to the GPP data within a Bayesian framework, and modeled the maximum GPP rate (Gmax) and canopy light-use efficiency (Q) as functions of N and current and antecedent SWC, T, and VPD. The model fit the GPP data well (R2 = 0.64), and regardless of the PHACE treatment the most important drivers of GPP were N (for Gmax), VPD (Gmax and Q), antecedent T (Gmax), and antecedent VPD (Q). Model simulations predicted that annual GPP increased on average by about 16% with eCO2, 14% with warming, 12% with eCO2 and warming, and 23% with irrigation. For four of the six years, annual GPP was significantly affected by either eCO2 alone or when combined with warming. The increase in annual GPP under irrigation was similar to the increase under eCO2 during a dry year (2012), but irrigation stimulated GPP to a greater degree than eCO2 during wet years (2008, 2009). Hence, increases in GPP under eCO2 appear to be indirectly due to increases in SWC, especially under dry conditions. These results suggest that future climate scenarios will lead to more productive grasslands in semiarid regions, but the overall response of the C cycle and the potential for these systems to sequester greater C will depend on the magnitude and direction of both the Reco and GPP responses.

Are sexual media exposure, parental restrictions on media use and co-viewing TV and DVDs with parents and friends associated with teenagers' early sexual behaviour?☆

PubMed Central

Parkes, Alison; Wight, Daniel; Hunt, Kate; Henderson, Marion; Sargent, James

2013-01-01

Sexual content in teenagers' media diets is known to predict early sexual behaviour. Research on sexual content has not allowed for the social context of media use, which may affect selection and processing of content. This study investigated whether sexual media content and/or contextual factors (co-viewing, parental media restrictions) were associated with early sexual behaviour using 2251 14–15 year-olds from Scotland, UK. A third (n = 733) reported sexual intercourse. In multivariable analysis the likelihood of intercourse was lower with parental restriction of sexual media and same-sex peer co-viewing; but higher with mixed-sex peer co-viewing. Parental co-viewing, other parental restrictions on media and sexual film content exposure were not associated with intercourse. Findings suggest the context of media use may influence early sexual behaviour. Specific parental restrictions on sexual media may offer more protection against early sex than other restrictions or parental co-viewing. Further research is required to establish causal mechanisms. PMID:24215959

Are sexual media exposure, parental restrictions on media use and co-viewing TV and DVDs with parents and friends associated with teenagers' early sexual behaviour?

PubMed

Parkes, Alison; Wight, Daniel; Hunt, Kate; Henderson, Marion; Sargent, James

2013-12-01

Sexual content in teenagers' media diets is known to predict early sexual behaviour. Research on sexual content has not allowed for the social context of media use, which may affect selection and processing of content. This study investigated whether sexual media content and/or contextual factors (co-viewing, parental media restrictions) were associated with early sexual behaviour using 2251 14-15 year-olds from Scotland, UK. A third (n = 733) reported sexual intercourse. In multivariable analysis the likelihood of intercourse was lower with parental restriction of sexual media and same-sex peer co-viewing; but higher with mixed-sex peer co-viewing. Parental co-viewing, other parental restrictions on media and sexual film content exposure were not associated with intercourse. Findings suggest the context of media use may influence early sexual behaviour. Specific parental restrictions on sexual media may offer more protection against early sex than other restrictions or parental co-viewing. Further research is required to establish causal mechanisms. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Soil respiration characteristics in different land uses and response of soil organic carbon to biochar addition in high-latitude agricultural area.

PubMed

Ouyang, Wei; Geng, Xiaojun; Huang, Wejia; Hao, Fanghua; Zhao, Jinbo

2016-02-01

The farmland tillage practices changed the soil chemical properties, which also impacted the soil respiration (R s ) process and the soil carbon conservation. Originally, the farmland in northeast China had high soil carbon content, which was decreased in the recent decades due to the tillage practices. To better understand the R s dynamics in different land use types and its relationship with soil carbon loss, soil samples at two layers (0-15 and 15-30 cm) were analyzed for organic carbon (OC), total nitrogen (TN), total phosphorus (TP), total carbon (TC), available nitrogen (AN), available phosphorus (AP), soil particle size distribution, as well as the R s rate. The R s rate of the paddy land was 0.22 (at 0-15 cm) and 3.01 (at 15-30 cm) times of the upland. The average concentrations of OC and clay content in cultivated areas were much lower than in non-cultivated areas. The partial least squares analysis suggested that the TC and TN were significantly related to the R s process in cultivated soils. The upland soil was further used to test soil CO2 emission response at different biochar addition levels during 70-days incubation. The measurement in the limited incubation period demonstrated that the addition of biochar improved the soil C content because it had high concentration of pyrogenic C, which was resistant to mineralization. The analysis showed that biochar addition can promote soil OC by mitigating carbon dioxide (CO2) emission. The biochar addition achieved the best performance for the soil carbon conservation in high-latitude agricultural area due to the originally high carbon content.

Facilitating Co-Authoring: Reflections of Content and Language Lecturers

ERIC Educational Resources Information Center

Wright, J.

2010-01-01

During a content and language project at a University of Technology (UoT) in Cape Town, South Africa, pairs of language and content lecturers, whose broad definition of integration was "the provision of linguistic access to content knowledge", co-authored ten integrated textbooks. Their intention was to assist first year learners with…

[Modern operations management in workflow operation. Spectrum of responsibilities and challenges for the future].

PubMed

Riedl, S

2002-02-01

The operating unit is one of the cost-intensive facilities in a surgical clinic with a pacemaking function for most of the internal procedures. The power of performance of the operating unit is based on the co-operation of all disciplines and professions involved. The key to management of the operating unit is not only to co-ordinate the daily procedures, but also to interact with support personnel. To ensure successful OR management, the internal structure of the OR must fit the clinical tasks and the available quantity of personnel in each profession must be co-ordinated. Sufficient utilization of resources and equipment must be guaranteed without cost-intensive over-capacities and patient flow must be orientated to OR capacities. The development of such a business structure requires the management to clearly define the goal, to know the actual on-site data in detail with regard to the idiosyncratic workings of each speciality and to clearly assign the competence of each member of the team working in the OR. Co-ordination of the operating unit is the main task of OR management, which must ensure the following: transparent and co-ordinated schedule management in the various operative specialities, goal-directed changes of the schedule with incorporation of emergencies, as well as effective organization of staff. In order to realize these tasks, it is reasonable to implement interdisciplinary rules of procedures. In addition, the assignment of a neutral decision-making body within the OR and the creation of an information center for all OR personnel. The challenge of OR organization in the future is to implement more effective documentation systems and active controlling within the OR. One can ensure adequate utilization of resources in the OR with prospectively oriented planning. Better transparence of operations in the OR contributes to increased efficiency. Implementation of quality management is the foundation for a successfully operating surgical hospital. Not only the productivity of individual members of the staff, but also the precise documentation of the quality of results will become important parameters in a successful surgical hospital, whose nucleus is the OR.

Carbon Monoxide Is Involved in Hydrogen Gas-Induced Adventitious Root Development in Cucumber under Simulated Drought Stress

PubMed Central

Chen, Yue; Wang, Meng; Hu, Linli; Liao, Weibiao; Dawuda, Mohammed M.; Li, Chunlan

2017-01-01

Hydrogen gas (H2) and carbon monoxide (CO) are involved in plant growth and developmental processes and may induce plant tolerance to several stresses. However, the independent roles and interaction effect of H2 and CO in adventitious root development under drought conditions have still not received the needed research attention. We hypothesize that there exists crosstalk between H2 and CO during adventitious root development under drought stress. The results of our current study revealed that 50% (v/v) hydrogen-rich water (HRW), 500 μM Hemin (the CO donor) and 30% (w/v) CO aqueous solution apparently promoted the development of adventitious roots in cucumber explants (Cucumis Sativus L.) under drought stress. H2 and CO increased relative water content (RWC), leaf chlorophyll content (chlorophyll a, b, and a+b), and chlorophyll fluorescence parameters [photochemical efficiency of photosystem II (PSII), PSII actual photochemical efficiency and photochemical quench coefficient] under drought condition. When the CO scavenger hemoglobin (Hb) or zinc protoporphyrin IX (ZnPPIX) was added to HRW/CO aqueous solution, the positive effect of HRW/CO aqueous solution on RWC, leaf chlorophyll content, and chlorophyll fluorescence parameters were reversed. Additionally, superoxide dismutases, peroxidase, catalase, and ascorbate peroxidase was significantly increased in the explants treated with HRW and CO aqueous solution under drought stress, thus alleviating oxidative damage, as indicated by decreases in thiobarbituric acid reactive substances (TBARS), hydrogen peroxide (H2O2), and superoxide radical (O2-) levels. H2 and CO also improved the levels of water soluble carbohydrate, total soluble protein, and proline content. However, the above CO/H2-mediated effects were reversed by CO scavenger Hb or CO specific synthetic inhibitor ZnPPIX. Therefore, CO may be involved in H2-induced adventitious rooting under drought stress and alleviate oxidative damage by enhancing RWC, leaf chlorophyll content, chlorophyll fluorescence parameters, metabolic constituent content, activating anti-oxidant enzymes and reducing TBARS, O2-, and H2O2 levels. PMID:28223992

The fabrication of porous N-doped carbon from widely available urea formaldehyde resin for carbon dioxide adsorption.

PubMed

Liu, Zhen; Du, Zhenyu; Song, Hao; Wang, Chuangye; Subhan, Fazle; Xing, Wei; Yan, Zifeng

2014-02-15

N-doped carbon material constitutes abundant of micropores and basic nitrogen species that have potential implementation for CO2 capture. In this paper, porous carbon material with high nitrogen content was simply fabricated by carbonizing low cost and widely available urea formaldehyde resin, and then followed by KOH activation. CO2 capture experiment showed high adsorption capacity of 3.21 mmol g(-1) at 25 °C under 1 atm for UFCA-2-600. XRD, SEM, XPS and FT-IR analysis confirmed that a graphitic-like structure was retained even after high temperature carbonization and strong base activation. Textural property analysis revealed that narrow micropores, especially below 0.8 nm, were effective for CO2 adsorption by physical adsorption mechanism. Chemical evolved investigation revealed that graphitic-like embedded basic nitrogen groups are generated from bridged and terminal amines of urea formaldehyde resin from thermal carbonization and KOH activation treatment, which is responsible for the enrichment of CO2 capacity by chemical adsorption mechanism. The relationship between CO2 adsorption capacity and pore size or basic N species was also studied, which turned out that both of them played crucial role by physical and chemical adsorption mechanism, respectively. Copyright © 2013 Elsevier Inc. All rights reserved.

Effect of cold storage on total phenolics content, antioxidant activity and vitamin C level of selected potato clones.

PubMed

Külen, Oktay; Stushnoff, Cecil; Holm, David G

2013-08-15

Twelve Colorado-grown specialty potato clones were evaluated for total phenolic content, antioxidant activity and ascorbic acid content at harvest and after 2, 4, 6 and 7 months cold storage at 4 °C. Potato clones were categorized as pigmented ('CO97226-2R/R', 'CO99364-3R/R', 'CO97215-2P/P', 'CO97216-3P/P', 'CO97227-2P/P', 'CO97222-1R/R', 'Purple Majesty', 'Mountain Rose' and 'All Blue'), yellow ('Yukon Gold') and white fleshed ('Russet Nugget', 'Russet Burbank'). Folin-Ciocalteu reagent was used to estimate total phenolic content, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS(•+) ) and 2,2-diphenyl-1-picrylhydrazyl (DPPH(•) ) radical scavenging assays were used to estimate antioxidant capacity. Pigmented potato genotypes had significantly higher total phenolic content and antioxidant activity at all data points than yellow- and white-fleshed cultivars. Vitamin C content was higher in 'Yukon Gold' than in the other clones. The highest level of vitamin C in all clones was at harvest and after 2 months in cold storage. Vitamin C content in all potato clones dropped rapidly with longer intervals of cold storage. Although total phenolic content and antioxidant activity fluctuated during cold storage, after 7 months of cold storage their levels were slightly higher than at harvest. Total phenolic content was better correlated with Trolox equivalent antioxidant capacity (TEAC)/ABTS(•+) than the TEAC/DPPH(•) radical scavenging assay. Pigmented potato clones had significantly higher total phenolic content and antioxidant activity, while the yellow-fleshed potato cultivar 'Yukon Gold' had significantly higher vitamin C content. Vitamin C content decreased in all potato clones during cold storage, while total phenolics increased in pigmented clones. © 2013 Society of Chemical Industry.

The Role of Postgraduate Students in Co-Authoring Open Educational Resources to Promote Social Inclusion: A Case Study at the University of Cape Town

ERIC Educational Resources Information Center

Hodgkinson-Williams, Cheryl; Paskevicius, Michael

2012-01-01

Like many universities worldwide, the University of Cape Town (UCT) in South Africa has joined the open educational resources (OER) movement, making a selection of teaching and learning materials available through its OER directory, UCT OpenContent. However, persuading and then supporting busy academics to share their teaching materials as OER…

Effects of CO 2 concentration and moisture content of sugar-free media on the tissue-cultured plantlets in a large growth chamber

NASA Astrophysics Data System (ADS)

Qu, Y. H.; Lin, C.; Zhou, W.; Li, Y.; Chen, B.; Chen, G. Q.

2009-01-01

The dynamic fluctuations of CO 2 concentration in the tissue culture growth chamber after transplantation of petunia, chrysanthemum and tomato plantlets were recorded with a real-time control system to determine the critical CO 2 concentration levels of 35 μl l -1 at which CO 2 enrichment is needed. The experimental data showed that the tissue-cultured plantlets of petunia, chrysanthemum and tomato had the same CO 2 concentration dynamics. The results indicated that CO 2 enrichment was proper on the second day after transplantation. Petunia plantlets were used to conduct experiments under PPFD of 80 μmol m -2 s -1, and CO 2 concentrations of 350 ± 50 μl l -1, 650 ± 50 μl l -1 and 950 ± 50 μl l -1 as well as medium moisture contents of 60%, 70% and 80%, with the result that plantlets grew better under CO 2 concentration of 650 ± 50 μl l -1 than under the other two concentrations with all the different media water contents. Three media water contents under the same CO 2 concentration produced plantlets with the same quality. The impacts of CO 2 concentrations on plantlets are more important than those of the media water contents. Sugar-free tissue culture, as compared with the conventional culture, showed that CO 2 enrichment to 350 ± 50 μl l -1 can promote the growth of the cultured plantlets. Sugar-free tissue culture produced healthy plantlets with thick roots, almost equivalent to the common plantlets.

Feasibility Study of Coal Gasification/Fuel Cell/Cogeneration Project. Fort Hood, Texas Site. Project Description,

DTIC Science & Technology

1985-07-01

and Operation 132 6.7.5 Safety 135 6.7.6 System Control Description 136 6.7.6.1 Coal Gasification 136 6.7.6.2 Gas Cooling, Cleaning and Compression...the hydrogen content. The gas is then desulfurized and heated before final polishing and feeding to the fuel cell. Receiving compressed fuel gas and...4 CO Shift 1 Stretford Desulfurizer 3 Gas Compressors 3 Material Handling(3) 3 Subtotal 39 Scheduled Shutdown 14 Total Annual Shutdown 53

The role of carbon dioxide in the transport and fractionation of metals by geological fluids

NASA Astrophysics Data System (ADS)

Kokh, Maria A.; Akinfiev, Nikolay N.; Pokrovski, Gleb S.; Salvi, Stefano; Guillaume, Damien

2017-01-01

Although carbon dioxide is one of the major components of crustal fluids responsible for ore deposit formation, its effect on transport and precipitation of metals remains unknown, due to a lack of direct experimental data and physical-chemical models for CO2-rich fluids. To fill this gap, we combined laboratory experiments and thermodynamic modeling to systematically quantify the role played by CO2 for the solubility of economically important metals such as Fe, Cu, Zn, Au, Mo, Pt, Sn under hydrothermal conditions. Solubility measurements of common ore minerals of these metals (FeS2, CuFeS2, ZnS, Au, MoS2, PtS, SnO2) were performed, using a flexible-cell reactor equipped with a rapid sampling device, in a single-phase fluid (CO2-H2O-KCl) at 350-450 °C and 600-750 bar, buffered with iron sulfide and oxide and alkali-aluminosilicate mineral assemblages. In addition, another type of experiments was conducted to measure gold solubility in more sulfur-rich supercritical CO2-H2O-S-NaOH fluids at 450 °C and 700 bar using a batch reactor that allows fluid quenching. Our results show that the solubilities of Si, Au, Mo, Pt and Cu either decrease (within <1 log unit) or remain constant upon CO2 increase, whereas those of Fe, Zn and Sn increase significantly (>1 log unit) with CO2 contents in the fluid increasing from 0 to 50 wt%. These data were interpreted using a simple model that does not require any new adjustable parameters, and is based on the dielectric constant of the H2O-CO2 solvent and on the Born solvation parameter for the dominant metal-bearing species in an aqueous fluid. Our predictions using this model suggest that in a supercritical CO2-H2O-S-salt fluid typical of metamorphic Au deposits, in equilibrium with pyrite and chalcopyrite, the Cu/Fe ratio decreases by up to 2 orders of magnitude with an increase of CO2 content from 0 to 70 wt%. This effect is due to the decrease of the fluid dielectric constant in the presence of CO2, which favors the stability of neutral species (FeCl20) compared to charged ones (CuCl2-). Our results explain the Fe enrichment and Cu depletion in metamorphic gold deposits formed by CO2-rich fluids. The transport of gold is unfavorable in the presence of CO2 only in S-rich (>0.5 wt% S) fluids in which Au forms the negatively charged Au(HS)2- and Au(HS)S3- complexes. By contrast, it is only weakly affected in S-poor (<0.1 wt% S) acidic-to-neutral fluids in which the uncharged Au(HS)0 complex predominates. Thus, even at very high CO2 contents (>50 wt% CO2), the capacity of such fluids to transport gold (up to 100s ppb Au) remains comparable to that of aqueous fluids. These findings are in agreement with analyses of natural fluid inclusions in metamorphic deposits. In more saline oxidizing and S-rich fluids such as those in magmatic porphyry Cu-Au deposits, the Fe, Cu, and Au solubilities in the presence of CO2 decrease by ∼1 order of magnitude with CO2 increasing to 20-30 wt%, following the decrease in the stability of their dominant charged species (FeCl42-, CuCl2-, Au(HS)2- and Au(HS)S3-), but stay almost constant at higher CO2 contents (30-70 wt%) as controlled by the neutral species (FeCl20, Cu(HS)0 and Au(HS)0). Such solubility trends suggest a new potential trigger of ore precipitation in porphyry systems by CO2 pulses from the magmatic chamber, which may operate along with commonly admitted depositional mechanisms such as cooling, vapor-brine immiscibility, and water-rock interaction. The direct effect of CO2 on the mobility of Pt and Mo, metals that likely form hydrogen sulfide and oxy-hydroxide complexes, respectively, is expected to be weak in most settings. Among the studied elements, Sn is the only one whose solubility may be favored at high CO2 content (>20 wt%) due to carbonate complexing. This study demonstrates, for the first time, that, contrary to common belief, the presence of CO2 in a supercritical fluid may lead to enhanced mobility or, on contrary, to massive precipitation of some metals, depending on salinity and sulfur content, and, more generally, to significant fractionations between different metals.

Exploring the impact of co-varying water availability and energy price on productivity and profitability of Alpine hydropower

NASA Astrophysics Data System (ADS)

Anghileri, Daniela; Botter, Martina; Castelletti, Andrea; Burlando, Paolo

2016-04-01

Alpine hydropower systems are experiencing dramatic changes both from the point of view of hydrological conditions, e.g., water availability and frequency of extremes events, and of energy market conditions, e.g., partial or total liberalization of the market and increasing share of renewable power sources. Scientific literature has, so far, mostly focused on the analysis of climate change impacts and associated uncertainty on hydropower operation, underlooking the consequences that socio-economic changes, e.g., energy demand and/or price changes, can have on hydropower productivity and profitability. In this work, we analyse how hydropower reservoir operation is affected by changes in both water availability and energy price. We consider stochastically downscaled climate change scenarios of precipitation and temperature to simulate reservoir inflows using a physically explicit hydrological model. We consider different scenarios of energy demand and generation mix to simulate energy prices using an electricity market model, which includes different generation sources, demand sinks, and features of the transmission lines. We then use Multi-Objective optimization techniques to design the operation of hydropower reservoirs for different purposes, e.g. maximization of revenue and/or energy production. The objective of the work is to assess how the tradeoffs between the multiple operating objectives evolve under different co-varying climate change and socio-economic scenarios and to assess the adaptive capacity of the system. The modeling framework is tested on the real-world case study of the Mattmark reservoir in Switzerland.

Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

NASA Astrophysics Data System (ADS)

Neubauer, S. C.; Franklin, R. B.; Berrier, D. J.

2013-07-01

Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced roughly 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2) and methane (CH4) production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent with short-term disturbance-type responses.

Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

NASA Astrophysics Data System (ADS)

Neubauer, S. C.; Franklin, R. B.; Berrier, D. J.

2013-12-01

Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced ~ 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2) and methane (CH4) production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent with short-term disturbance-type responses.

PtCo Cathode Catalyst Morphological and Compositional Changes after PEM Fuel Cell Accelerated Stress Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sneed, Brian T.; Cullen, David A.; Mukundan, R.

Development of Pt catalysts alloyed with transition metals has led to a new class of state-of-the-art electrocatalysts for oxygen reduction at the cathode of proton exchange membrane fuel cells; however, the durability of Pt-based alloy catalysts is challenged by poor structural and chemical stability. There is a need for better understanding of the morphological and compositional changes that occur to the catalyst under fuel cell operation. In this work, we report in-depth characterization results of a Pt-Co electrocatalyst incorporated in the cathode of membrane electrode assemblies, which were evaluated before and after accelerated stress tests designed specifically to enhance catalystmore » degradation. Electron microscopy, spectroscopy, and 3D electron tomography analyses of the Pt-Co nanoparticle structures suggest that the small- and intermediate-sized Pt-Co particles, which are typically Pt-rich in the fresh condition, undergo minimal morphological changes, whereas intermediate- and larger-sized Pt-Co nanoparticles that exhibit a porous “spongy” morphology and initially have a higher Co content, transform into hollowed-out shells, which is driven by continuous leaching of Co from the Pt-Co catalysts. We further show how these primary Pt-Co nanoparticle morphologies group toward a lower Co, larger size portion of the size vs. composition distribution, and provide details of their nanoscale morphological features.« less

PtCo Cathode Catalyst Morphological and Compositional Changes after PEM Fuel Cell Accelerated Stress Testing

DOE PAGES

Sneed, Brian T.; Cullen, David A.; Mukundan, R.; ...

2018-03-01

Development of Pt catalysts alloyed with transition metals has led to a new class of state-of-the-art electrocatalysts for oxygen reduction at the cathode of proton exchange membrane fuel cells; however, the durability of Pt-based alloy catalysts is challenged by poor structural and chemical stability. There is a need for better understanding of the morphological and compositional changes that occur to the catalyst under fuel cell operation. In this work, we report in-depth characterization results of a Pt-Co electrocatalyst incorporated in the cathode of membrane electrode assemblies, which were evaluated before and after accelerated stress tests designed specifically to enhance catalystmore » degradation. Electron microscopy, spectroscopy, and 3D electron tomography analyses of the Pt-Co nanoparticle structures suggest that the small- and intermediate-sized Pt-Co particles, which are typically Pt-rich in the fresh condition, undergo minimal morphological changes, whereas intermediate- and larger-sized Pt-Co nanoparticles that exhibit a porous “spongy” morphology and initially have a higher Co content, transform into hollowed-out shells, which is driven by continuous leaching of Co from the Pt-Co catalysts. We further show how these primary Pt-Co nanoparticle morphologies group toward a lower Co, larger size portion of the size vs. composition distribution, and provide details of their nanoscale morphological features.« less

[Effects of elevated atmospheric CO2 and nitrogen application on cotton biomass, nitrogen utilization and soil urease activity].

PubMed

Lyu, Ning; Yin, Fei-hu; Chen, Yun; Gao, Zhi-jian; Liu, Yu; Shi, Lei

2015-11-01

In this study, a semi-open-top artificial climate chamber was used to study the effect of CO2 enrichment (360 and 540 µmol · mol(-1)) and nitrogen addition (0, 150, 300 and 450 kg · hm(-2)) on cotton dry matter accumulation and distribution, nitrogen absorption and soil urease activity. The results showed that the dry matter accumulation of bud, stem, leaf and the whole plant increased significantly in the higher CO2 concentration treatment irrespective of nitrogen level. The dry matter of all the detected parts of plant with 300 kg · hm(-2) nitrogen addition was significantly higher than those with the other nitrogen levels irrespective of CO2 concentration, indicating reasonable nitrogen fertilization could significantly improve cotton dry matter accumulation. Elevated CO2 concentration had significant impact on the nitrogen absorption contents of cotton bud and stem. Compared to those under CO2 concentration of 360 µmol · mol(-1), the nitrogen contents of bud and stem both increased significantly under CO2 concentration of 540 µmol · mol(-1). The nitrogen content of cotton bud in the treatment of 300 kg · hm(-2) nitrogen was the highest among the four nitrogen fertilizer treatments. While the nitrogen contents of cotton stem in the treatments of 150 kg · hm(-2) and 300 kg · hm(-2) nitrogen levels were higher than those in the treatment of 0 kg · hm(-2) and 450 kg · hm(-2) nitrogen levels. The nitrogen content of cotton leaf was significantly influenced by the in- teraction of CO2 elevation and N addition as the nitrogen content of leaf increased in the treatments of 0, 150 and 300 kg · hm(-2) nitrogen levels under the CO2 concentration of 540 µmol · mol(-1). The nitrogen content in cotton root was significantly increased with the increase of nitrogen fertilizer level under elevated CO2 (540 µmol · mol(-1)) treatment. Overall, the cotton nitrogen absorption content under the elevated CO2 (540 µmol · mol(-1)) treatment was higher than that under the ambient CO2- (360 µmol · mol(-1)) treatment. The order of nitrogen accumulation content in organs was bud > leaf > stem > root. Soil urease activity of both layers increased significantly with the elevation of CO2 concentration in all the nitrogen treatments. Under each CO2 concentration treatment, the soil urease activity in the upper layer (0-20 cm) increased significantly with nitrogen application, while the urease activity under the application of 300 kg · hm(-2) nitrogen was highest in the lower layer (20- 40 cm). The average soil urease activity in the upper layer (0-20 cm) was significantly higher than that in the lower layer (20-40 cm). This study suggested that the cotton dry matter accumulation and nitrogen absorption content were significantly increased in response to the elevated CO2 concentration (540 µmol · mol(-1)) and higher nitrogen addition (300 kg · hm(-2)).

Evolution of CO2 in lakes Monoun and Nyos, Cameroon, before and during controlled degassing

USGS Publications Warehouse

Kusakabe, M.; Ohba, T.; Issa,; Yoshida, Y.; Satake, H.; Ohizumi, T.; Evans, William C.; Tanyileke, G.; Kling, G.W.

2008-01-01

Evolution of CO2 in Lakes Monoun and Nyos (Cameroon) before and during controlled degassing is described using results of regular monitoring obtained during the last 21 years. The CO2(aq) profiles soon after the limnic eruptions were estimated for Lakes Monoun and Nyos using the CTD data obtained in October and November 1986, respectively. Based on the CO2(aq) profiles through time, the CO2 Content and its change over time were calculated for both lakes. The CO2 accumulation rate calculated from the pre-degassing data, was constant after the limnic eruption at Lake Nyos (1986-2001), whereas the rate appeared initially high (1986-1996) but later slowed down (1996-2003) at Lake Monoun. The CO2 concentration at 58 m depth in Lake Monoun in January 2003 was very close to saturation due to the CO2 accumulation. This situation is suggestive of a mechanism for the limnic eruption, because it may take place spontaneously without receiving an external trigger. The CO2 content of the lakes decreased significantly after controlled degassing started in March 2001 at Lake Nyos and in February 2003 at Lake Monoun. The current content is lower than the content estimated soon after the limnic eruption at both lakes. At Monoun the degassing rate increased greatly after February 2006 due to an increase of the number of degassing pipes and deepening of the pipe intake depth. The current CO2 content is ???40% of the maximum content attained just before the degassing started. At current degassing rates the lower chemocline will subside to the degassing pipe intake depth of 93 m in about one year. After this depth is reached, the gas removal rate will progressively decline because water of lower CO2(aq) concentration will be tapped by the pipes. To keep the CO2 content of Lake Monoun as small as possible, it is recommended to set up a new, simple device that sends deep water to the surface since natural recharge of CO2 will continue. Controlled degassing at Lake Nyos since 2001 has also reduced the CO2 content. It is currently slightly below the level estimated after the limnic eruption in 1986. However, the current CO2 content still amounts to 80% of the maximum level of 14.8 giga moles observed in January 2001. The depth of the lower chemocline may reach the pipe intake depth of 203 m within a few years. After this situation is reached the degassing rate with the current system will progressively decline, and it would take decades to remove the majority of dissolved gases even if the degassing system keeps working continuously. Additional degassing pipes must be installed to speed up gas removal from Lake Nyos in order to make the area safer for local populations. Copyright ?? 2008 by The Geochemical Society of Japan.

Influences of vanadium on magnetocrystalline anisotropy and magnetic properties of Gd2Co17-xVx

NASA Astrophysics Data System (ADS)

Chu, W. G.; Rao, G. H.; Liu, G. Y.; Yang, H. F.; Liu, W. F.; Ouyang, Z. W.; Feng, X. M.; Liang, J. K.

2002-12-01

Single-phase Gd2Co17-xVx compounds (x=0.0-1.5) crystallizing in the rhombohedral Th2Zn17 structure have been synthesized. The lattice parameters a and c of the compounds increase linearly with increasing V content, and the rate of increase of c is about 2.5 times as large as that of a. Substitution of a small amount of V atoms (x=0.3) for Co atoms leads to the occurrence of uniaxial magnetocrystalline anisotropy of Gd2Co17-xVx. The anisotropy field HA increases drastically with increasing V content. The variations of both the lattice parameters and the magnetocrystalline anisotropy with V content suggest a preferential occupation of the V atoms at the 6c dumbbell site. The Curie temperature TC, saturation moment MS, and average Co moment <μCo> of the compounds decrease greatly as the V content increases. The rapid decrease of TC is essentially attributed to a serious weakening of the Co-Co interactions due to the preferential occupation of the V atoms at the 6c site. The effect of a strong hybridization between the V and Co atoms is plausibly responsible for the decreases of the MS and <μCo>.

Measurements of aircraft emissions indices at airports passive remote sensing

NASA Astrophysics Data System (ADS)

Schaefer, Klaus; Jahn, Carsten; Sturm, Peter J.; Lechner, Bernhard; Bacher, Michael

2003-04-01

The emission indices of aircraft engine exhausts to calculate precisely the emissions inventories of airports are not available up to now from measurements taken under operating conditions. To determine these data no installations nearby or behind the aircraft are possible at airports. That's why measurements by FTIR emission spectrometry were performed by the IMK-IFU with a spectrometer installed in a van and with total measurement time at one thrust level of about 1 minute to determine CO, NO and CO2. The FTIR instrument telescope was aligned to the engine nozzle exit of standing aircraft. A DOAS and a FTIR spectrometer with globar were used for simultaneous open-path measurements of NO, NO2, CO, CO2 and speciated hydrocarbons behind the aircraft by the TUG-VKMB. Measurement results at the airports Frankfurt/Main, London-Heathrow and Vienna are presented. The methods are evaluated by comparing CO emission indices from passive measurements with open-path data. The measured emission indices of CO show slightly higher values than the International Civil Aviation Organisation data sheets but less values for NOx emissions. A fruitful co-operation with the airlines AUA, BA and DLH as well as the airport authorities in Vienna and London-Heathrow supported this work which is financed from EC.

Development of a database for the verification of trans-ionospheric remote sensing systems

NASA Astrophysics Data System (ADS)

Leitinger, R.

2005-08-01

Remote sensing systems need verification by means of in-situ data or by means of model data. In the case of ionospheric occultation inversion, ionosphere tomography and other imaging methods on the basis of satellite-to-ground or satellite-to-satellite electron content, the availability of in-situ data with adequate spatial and temporal co-location is a very rare case, indeed. Therefore the method of choice for verification is to produce artificial electron content data with realistic properties, subject these data to the inversion/retrieval method, compare the results with model data and apply a suitable type of “goodness of fit” classification. Inter-comparison of inversion/retrieval methods should be done with sets of artificial electron contents in a “blind” (or even “double blind”) way. The set up of a relevant database for the COST 271 Action is described. One part of the database will be made available to everyone interested in testing of inversion/retrieval methods. The artificial electron content data are calculated by means of large-scale models that are “modulated” in a realistic way to include smaller scale and dynamic structures, like troughs and traveling ionospheric disturbances.

Sustained release of diltiazem HCl tableted after co-spray drying and physical mixing with PVAc and PVP.

PubMed

Al-Zoubi, Nizar; Al-Obaidi, Ghada; Tashtoush, Bassam; Malamataris, Stavros

2016-01-01

In this work, aqueous diltiazem HCl and polyvinyl-pyrrolidone (PVP) solutions were mixed with Kollicoat SR 30D and spray dried to microparticles of different drug:excipient ratio and PVP content. Co-spray dried products and physical mixtures of drug, Kollidon SR and PVP were tableted. Spray drying process, co-spray dried products and compressibility/compactability of co-spray dried and physical mixtures, as well as drug release and water uptake of matrix-tablets was evaluated. Simple power equation fitted drug release and water uptake (R(2) > 0.909 and 0.938, respectively) and correlations between them were examined. Co-spray dried products with PVP content lower than in physical mixtures result in slower release, while at equal PVP content (19 and 29% w/w of excipient) in similar release (f2 > 50). Increase of PVP content increases release rate and co-spray drying might be an alternative, when physical mixing is inadequate. Co-spray dried products show better compressibility/compatibility but higher stickiness to the die-wall compared to physical mixtures. SEM observations and comparison of release and swelling showed that distribution of tableted component affects only the swelling, while PVP content for both co-spray dried and physical mixes is major reason for release alterations and an aid for drug release control.

Structural and magnetic properties of La–Co substituted Sr–Ca hexaferrites synthesized by the solid state reaction method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Yujie; Liu, Xiansong, E-mail: xiansongliu@ahu.edu.cn; Jin, Dali

2014-11-15

Graphical abstract: The change of the remanence (B{sub r}) and intrinsic coercivity (H{sub cj}) with La content (x) and Co content (y) of hexagonal ferrite Sr{sub 0.7−x}Ca{sub 0.3}La{sub x}Fe{sub 12−y}Co{sub y}O{sub 19} magnets. - Highlights: • Sr{sub 0.7−x}Ca{sub 0.3}La{sub x}Fe{sub 12−y}Co{sub y}O{sub 19} hexaferrites were synthesized by the solid state reaction method. • B{sub r} continuously increases with increasing dopant contents. • H{sub cb}, H{sub cj} and (BH){sub max} for the magnets first increases and then decreases with an increase in the La–Co contents. - Abstract: Hexagonal ferrite Sr{sub 0.7−x}Ca{sub 0.3}La{sub x}Fe{sub 12−y}Co{sub y}O{sub 19} (x = 0.05–0.50; y =more » 0.04–0.40) magnetic powders and magnets were synthesized by the solid state reaction method. X-ray diffraction was employed to determine the phase compositions of the magnetic powders. There is a single magnetoplumbite phase in the magnetic powders with the substitution of La (0.05 ≤ x ≤ 0.15) and Co (0.04 ≤ y ≤ 0.12) contents. For the magnetic powders containing La (x ≥ 0.20) and Co (y ≥ 0.16), magnetic impurities begin to appear in the structure. A field emission scanning electron microscope was used to characterize the micrographs of the magnets. The magnets have formed hexagonal structures. Magnetic properties of the magnets were measured by a magnetic properties test instrument. The remanence continuously increases with increasing dopant contents. Whereas, the magnetic induction coercivity, intrinsic coercivity and maximum energy product for the magnets first increases and then decreases with an increase in the La–Co contents.« less

Co-Operation: The Antidote to Isolated Misery

ERIC Educational Resources Information Center

Jones, Sarah

2013-01-01

This is a case study demonstrating the impact the co-operative movement has had on one co-operative school in south-west England. Lipson Co-operative Academy in Plymouth was one of the first schools to convert to become a co-operative school in 2009. The article has been co-written by members of the Academy and focuses on three transformational…

A case-study of landfill minimization and material recovery via waste co-gasification in a new waste management scheme.

PubMed

Tanigaki, Nobuhiro; Ishida, Yoshihiro; Osada, Morihiro

2015-03-01

This study evaluates municipal solid waste co-gasification technology and a new solid waste management scheme, which can minimize final landfill amounts and maximize material recycled from waste. This new scheme is considered for a region where bottom ash and incombustibles are landfilled or not allowed to be recycled due to their toxic heavy metal concentration. Waste is processed with incombustible residues and an incineration bottom ash discharged from existent conventional incinerators, using a gasification and melting technology (the Direct Melting System). The inert materials, contained in municipal solid waste, incombustibles and bottom ash, are recycled as slag and metal in this process as well as energy recovery. Based on this new waste management scheme with a co-gasification system, a case study of municipal solid waste co-gasification was evaluated and compared with other technical solutions, such as conventional incineration, incineration with an ash melting facility under certain boundary conditions. From a technical point of view, co-gasification produced high quality slag with few harmful heavy metals, which was recycled completely without requiring any further post-treatment such as aging. As a consequence, the co-gasification system had an economical advantage over other systems because of its material recovery and minimization of the final landfill amount. Sensitivity analyses of landfill cost, power price and inert materials in waste were also conducted. The higher the landfill costs, the greater the advantage of the co-gasification system has. The co-gasification was beneficial for landfill cost in the range of 80 Euro per ton or more. Higher power prices led to lower operation cost in each case. The inert contents in processed waste had a significant influence on the operating cost. These results indicate that co-gasification of bottom ash and incombustibles with municipal solid waste contributes to minimizing the final landfill amount and has great possibilities maximizing material recovery and energy recovery from waste. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental determination of CO2 content at graphite saturation along a natural basalt-peridotite melt join: Implications for the fate of carbon in terrestrial magma oceans

NASA Astrophysics Data System (ADS)

Duncan, Megan S.; Dasgupta, Rajdeep; Tsuno, Kyusei

2017-05-01

Knowledge of the carbon carrying capacity of peridotite melt at reducing conditions is critical to constrain the mantle budget and planet-scale distribution of carbon set at early stage of differentiation. Yet, neither measurements of CO2 content in reduced peridotite melt nor a reliable model to extrapolate the known solubility of CO2 in basaltic (mafic) melt to solubility in peridotitic (ultramafic) melt exist. There are several reasons for this gap; one reason is due to the unknown relative contributions of individual network modifying cations, such as Ca2+ versus Mg2+, on carbonate dissolution particularly at reducing conditions. Here we conducted high pressure, temperature experiments to estimate the CO2 contents in silicate melts at graphite saturation over a compositional range from natural basalts toward peridotite at a fixed pressure (P) of 1.0 GPa, temperature (T) of 1600 °C, and oxygen fugacity (log ⁡ fO2 ∼ IW + 1.6). We also conducted experiments to determine the relative effects of variable Ca and Mg contents in mafic compositions on the dissolution of carbonate. Carbon in quenched glasses was measured and characterized using Fourier transform infrared spectroscopy (FTIR) and Raman Spectroscopy and was found to be dissolved as carbonate (CO32-). The FTIR spectra showed CO32- doublets that shifted systematically with the MgO and CaO content of silicate melts. Using our data and previous work we constructed a new composition-based model to determine the CO2 content of ultramafic (peridotitic) melt representative of an early Earth, magma ocean composition at graphite saturation. Our data and model suggest that the dissolved CO2 content of reduced, peridotite melt is significantly higher than that of basaltic melt at shallow magma ocean conditions; however, the difference in C content between the basaltic and peridotitic melts may diminish with depth as the more depolymerized peridotite melt is more compressible. Using our model of CO2 content at graphite saturation as a function of P-T-fO2-melt composition, we predict that a superliquidus shallow magma ocean should degas CO2. Whereas if the increase of fO2 with depth is weak, a magma ocean may ingas a modest amount of carbon during crystallization. Further, using the carbon content of peridotite melt at log ⁡ fO2 of IW and the knowledge of C content of Fe-rich alloy melt, we also consider the core-mantle partitioning of carbon, showing that DCmetal/peridotite of a shallow magma ocean is generally higher than previously estimated.

Promoting pedagogical content knowledge development for early career secondary teachers in science and technology using content representations

NASA Astrophysics Data System (ADS)

Williams, John; Eames, Chris; Hume, Anne; Lockley, John

2012-11-01

Background: This research addressed the key area of early career teacher education and aimed to explore the use of a 'content representation' (CoRe) as a mediational tool to develop early career secondary teacher pedagogical content knowledge (PCK). This study was situated in the subject areas of science and technology, where sound teacher knowledge is particularly important to student engagement. Purpose: The study was designed to examine whether such a tool (a CoRe), co-designed by an early career secondary teacher with expert content and pedagogy specialists, can enhance the PCK of early career teachers. The research questions were: How can experts in content and pedagogy work together with early career teachers to develop one science topic CoRe and one technology topic CoRe to support the development of PCK for early career secondary teachers? How does the use of a collaboratively designed CoRe affect the planning of an early career secondary teacher in science or technology? How has engagement in the development and use of an expert-informed CoRe developed an early career teacher's PCK? Sample: The research design incorporated a unique partnership between two expert classroom teachers, two content experts, four early career teachers, and four researchers experienced in science and technology education. Design: This study employed an interpretivist-based methodology and an action research approach within a four-case study design. Data were gathered using qualitative research methods focused on semi-structured interviews, observations and document analysis. Results: The study indicated that CoRes, developed through this collaborative process, helped the early career teachers focus on the big picture of the topic, emphasize particularly relevant areas of content and consider alternative ways of planning for their teaching. Conclusions: This paper presents an analysis of the process of CoRe development by the teacher-expert partnerships and the effect that had on the early career teachers' PCK. In addition, as the same tools and methodology were applied to both a science and a technology teaching context, differences between the two learning areas are discussed.

Durability of Pt-Co Alloy Polymer Electrolyte Fuel Cell Cathode Catalysts under Accelerated Stress Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papadias, D. D.; Ahluwalia, R. K.; Kariuki, N.

The durability of Pt-Co alloy cathode catalysts supported on high surface area carbon is investigated by subjecting them to accelerated stress tests (ASTs). The catalysts had different initial Co contents and nanoparticle morphologies: a “spongy” porous morphology for the high-Co (H) content catalyst, and a fully alloyed crystalline morphology for the medium-Co (M) and low-Co (L) content catalysts. The specific activity of the catalysts depends on their initial Co content, morphology and nanoparticle size, and remained higher than 1000 μA/cm 2-Pt after 27–50% Co loss. The H-catalyst electrode showed the smallest kinetic overpotentials (η c s) due to higher initialmore » Pt loading than the other two electrodes, but it had the fastest increase in ηcs with AST cycling due to lower Co retention; the L-catalyst electrode showed higher η c s due to a lower initial Pt loading, but had a smaller increase in η c s with aging due to higher Co retention; the M-catalyst electrode showed a similar increase in η c s with aging, but this increase was due to the combined effects of Co dissolution and electrochemically active surface area (ECSA) loss. In conclusion, the modeled increase in mass transfer overpotentials with aging correlates with the initial Pt loading, ECSA loss and the initial catalyst morphology« less

Durability of Pt-Co Alloy Polymer Electrolyte Fuel Cell Cathode Catalysts under Accelerated Stress Tests

DOE PAGES

Papadias, D. D.; Ahluwalia, R. K.; Kariuki, N.; ...

2018-03-17

The durability of Pt-Co alloy cathode catalysts supported on high surface area carbon is investigated by subjecting them to accelerated stress tests (ASTs). The catalysts had different initial Co contents and nanoparticle morphologies: a “spongy” porous morphology for the high-Co (H) content catalyst, and a fully alloyed crystalline morphology for the medium-Co (M) and low-Co (L) content catalysts. The specific activity of the catalysts depends on their initial Co content, morphology and nanoparticle size, and remained higher than 1000 μA/cm 2-Pt after 27–50% Co loss. The H-catalyst electrode showed the smallest kinetic overpotentials (η c s) due to higher initialmore » Pt loading than the other two electrodes, but it had the fastest increase in ηcs with AST cycling due to lower Co retention; the L-catalyst electrode showed higher η c s due to a lower initial Pt loading, but had a smaller increase in η c s with aging due to higher Co retention; the M-catalyst electrode showed a similar increase in η c s with aging, but this increase was due to the combined effects of Co dissolution and electrochemically active surface area (ECSA) loss. In conclusion, the modeled increase in mass transfer overpotentials with aging correlates with the initial Pt loading, ECSA loss and the initial catalyst morphology« less

Characterization of Nanocrystalline Nickel-Cobalt Alloys Synthesized by Direct and Pulse Electrodeposition

NASA Astrophysics Data System (ADS)

Salehi, M.; Saidi, A.; Ahmadian, M.; Raeissi, K.

2014-01-01

Nanocrystalline Ni-Co alloys are electrodeposited by direct (DC) and pulse current (PC) in an electrolyte solution which consisted of nickel sulfate, cobalt sulfate and boric acid. Electrodeposition parameters including current density, electrolyte pH and pulse times in a single electrolyte bath were changed. XRD pattern showed that the structure of the alloys depends on Co content and the synthesis parameter and changed from single phase structure (fcc) to dual phase structure (fcc + hcp). The Co content in the deposited alloys declined from 70 at.% to 50 at.% by increasing in direct current from 70 mA/cm2 to 115 mA/cm2 and also decreased from 75 at.% to 33 at.% with decrease in pH values from 4 to 2. By applying PC the Co content changed from 76 at.% to 41 at.%. Magnetic properties measurements showed the saturation magnetization (Ms) increased with increasing the Co content. There was no significant effect on coercivity values (Hc) with change in Co content and about 40 Oe was obtained for all samples. The grain size of deposited alloys obtained between 24-58 nm and 15-21 nm by applying DC and PC, respectively.

Effects of inoculum to substrate ratio and co-digestion with bagasse on biogas production of fish waste.

PubMed

Xu, Jie; Mustafa, Ahmed M; Sheng, Kuichuan

2017-10-01

To overcome the biogas inhibition in anaerobic digestion of fish waste (FW), effects of inoculum to substrate ratio (I/S, based on VS) and co-digestion with bagasse on biogas production of FW were studied in batch reactors. I/S value was from 0.95 to 2.55, bagasse content in co-digestion (based on VS) was 25%, 50% and 75%. The highest biogas yield (433.4 mL/gVS) with 73.34% methane content was obtained at an I/S value of 2.19 in mono-digestion of FW; the biogas production was inhibited and the methane content was below 70% when I/S was below 1.5. Co-digestion of FW and bagasse could improve the stability and biogas potential, also reducing the time required to obtain 70% of the total biogas production, although the total biogas yield and methane content decreased with the increase in bagasse content in co-digestion. Biogas yield of 409.5 mL/gVS was obtained in co-digestion of 75% FW and 25% bagasse; simultaneously 78.46% of the total biogas production was achieved after 10 days of digestion.

Contrasting effects of fish oil and safflower oil on hepatic peroxisomal and tissue lipid content.

PubMed

Neschen, Susanne; Moore, Irene; Regittnig, Werner; Yu, Chun Li; Wang, Yanlin; Pypaert, Marc; Petersen, Kitt Falk; Shulman, Gerald I

2002-02-01

To examine the mechanism by which fish oil protects against fat-induced insulin resistance, we studied the effects of control, fish oil, and safflower oil diets on peroxisomal content, fatty acyl-CoA, diacylglycerol, and ceramide content in rat liver and muscle. We found that, in contrast to control and safflower oil-fed rats, fish oil feeding induced a 150% increase in the abundance of peroxisomal acyl-CoA oxidase and 3-ketoacyl-CoA thiolase in liver but lacked similar effects in muscle. This was paralleled by an almost twofold increase in hepatic peroxisome content (both P < 0.002 vs. control and safflower). These changes in the fish oil-fed rats were associated with a more than twofold lower hepatic triglyceride/diacylglycerol, as well as intramuscular triglyceride/fatty acyl-CoA, content. In conclusion, these data strongly support the hypothesis that n-3 fatty acids protect against fat-induced insulin resistance by serving as peroxisome proliferator-activated receptor-alpha ligands and thereby induce hepatic, but not intramuscular, peroxisome proliferation. In turn, an increased hepatic beta-oxidative capacity results in lower hepatic triglyceride/diacylglycerol and intramyocellular triglyceride/fatty acyl-CoA content.

Contrasting effects of fish oil and safflower oil on hepatic peroxisomal and tissue lipid content

PubMed Central

Neschen, Susanne; Moore, Irene; Regittnig, Werner; Yu, Chun Li; Wang, Yanlin; Pypaert, Marc; Petersen, Kitt Falk; Shulman, Gerald I.

2010-01-01

To examine the mechanism by which fish oil protects against fat-induced insulin resistance, we studied the effects of control, fish oil, and safflower oil diets on peroxisomal content, fatty acyl-CoA, diacylglycerol, and ceramide content in rat liver and muscle. We found that, in contrast to control and safflower oil-fed rats, fish oil feeding induced a 150% increase in the abundance of peroxisomal acyl-CoA oxidase and 3-ketoacyl-CoA thiolase in liver but lacked similar effects in muscle. This was paralleled by an almost twofold increase in hepatic peroxisome content (both P < 0.002 vs. control and safflower). These changes in the fish oil-fed rats were associated with a more than twofold lower hepatic triglyceride/diacylglycerol, as well as intramuscular triglyceride/fatty acyl-CoA, content. In conclusion, these data strongly support the hypothesis that n-3 fatty acids protect against fat-induced insulin resistance by serving as peroxisome proliferator-activated receptor-α ligands and thereby induce hepatic, but not intramuscular, peroxisome proliferation. In turn, an increased hepatic β-oxidative capacity results in lower hepatic triglyceride/diacylglycerol and intramyocellular triglyceride/fatty acyl-CoA content. PMID:11788372

Carbon monoxide from composting due to thermal oxidation of biomass.

PubMed

Hellebrand, H J; Schade, G W

2008-01-01

Emissions of carbon monoxide (CO) were observed from decomposing organic wastes and litter under laboratory, pilot composting plant, and natural conditions. Field studies included air from inside a compost heap of about 200 m3, emissions from composting of livestock wastes at a biologically operating farm, and leaf litter pile air samples. The concentration of CO was up to 120 micromol mol(-1) in the compost piles of green waste, and up to 10 micromol mol(-1) in flux chambers above livestock waste windrow composts. The mean CO flux rates were approximately 20 mg CO m(-2) h(-1) for compost heaps of green waste, and varied from 30 to 100 mg CO m(-2) h(-1) for fresh dung windrows. Laboratory studies using a temperature and ventilation-controlled substrate container were performed to elucidate the origin of CO, and included hay samples of fixed moisture content at temperatures between 5 and 65 degrees C, including nonsterilized as well as sterilized samples. The concentration of CO was up to 160 micromol mol(-1) in these experiments, and Arrhenius-type plot analyses resulted in activation energies of 65 kJ mol(-1) for thermochemically produced CO from the nonsterilized compost substrate. Sterilized samples showed dramatically reduced CO2 but virtually unchanged CO emissions, albeit at a slightly lower activation energy, likely a result of the high-temperature sterilization. Though globally and regionally these CO emissions are only a minor source, thermochemically produced CO emissions might affect local air quality in and near composting facilities.

Abscisic Acid Content and Stomatal Sensitivity to CO2 in Leaves of Xanthium strumarium L. after Pretreatments in Warm and Cold Growth Chambers 1

PubMed Central

Raschke, Klaus; Pierce, Margaret; Popiela, Chu Chen

1976-01-01

The degree of stomatal sensitivity to CO2 was positively correlated with the content of abscisic acid of leaves of Xanthium strumarium grown in a greenhouse and then transferred for 24 hours or more to a cold (5/10 C, night/day) or a warm growth chamber (20/23 C). This correlation did not exist in plants kept in the greehouse continuously (high abscisic acid, no CO2 sensitivity), nor in plants transferred from the cold to the warm chamber (low abscisic acid, high CO2 sensitivity). The abscisic acid content of leaves was correlated with water content only within narrow limits, if at all. At equal water contents, prechilled leaves contained more abscisic acid than leaves of plants pretreated in the warm chamber. There appear to be at least two compartments for abscisic acid in the leaf. PMID:16659416

Abscisic Acid Content and Stomatal Sensitivity to CO(2) in Leaves of Xanthium strumarium L. after Pretreatments in Warm and Cold Growth Chambers.

PubMed

Raschke, K; Pierce, M; Popiela, C C

1976-01-01

The degree of stomatal sensitivity to CO(2) was positively correlated with the content of abscisic acid of leaves of Xanthium strumarium grown in a greenhouse and then transferred for 24 hours or more to a cold (5/10 C, night/day) or a warm growth chamber (20/23 C). This correlation did not exist in plants kept in the greehouse continuously (high abscisic acid, no CO(2) sensitivity), nor in plants transferred from the cold to the warm chamber (low abscisic acid, high CO(2) sensitivity). The abscisic acid content of leaves was correlated with water content only within narrow limits, if at all. At equal water contents, prechilled leaves contained more abscisic acid than leaves of plants pretreated in the warm chamber. There appear to be at least two compartments for abscisic acid in the leaf.

The influence of food supply on the response of Olympia oyster larvae to ocean acidification

NASA Astrophysics Data System (ADS)

Hettinger, A.; Sanford, E.; Hill, T. M.; Hosfelt, J. D.; Russell, A. D.; Gaylord, B.

2013-10-01

Increases in atmospheric carbon dioxide drive accompanying changes in the marine carbonate system as carbon dioxide (CO2) enters seawater and alters ocean pH (termed "ocean acidification"). However, such changes do not occur in isolation, and other environmental factors have the potential to modulate the consequences of altered ocean chemistry. Given that physiological mechanisms used by organisms to confront acidification can be energetically costly, we explored the potential for food supply to influence the response of Olympia oyster (Ostrea lurida) larvae to ocean acidification. In laboratory experiments, we reared oyster larvae under a factorial combination of pCO2 and food level. Elevated pCO2 had negative effects on larval growth, total dry weight, and metamorphic success, but high food availability partially offset these influences. The combination of elevated pCO2 and low food availability led to the greatest reduction in larval performance. However, the effects of food and pCO2 interacted additively rather than synergistically, indicating that they operated independently. Despite the potential for abundant resources to counteract the consequences of ocean acidification, impacts were never completely negated, suggesting that even under conditions of enhanced primary production and elevated food availability, impacts of ocean acidification may still accrue in some consumers.

'Part of the solution': Developing sustainable energy through co-operatives and learning

NASA Astrophysics Data System (ADS)

Duguid, Fiona C. B.

After five years of development, WindShare Co-operative in Toronto, Ontario became the first urban wind turbine in North America and the first co-operatively owned and operated wind turbine in Canada. The development of WindShare Co-operative has spurred the growth of a green energy co-operative sector in Ontario. This study, which included 27 interviews and a focus group with members of WindShare Co-operative, focuses on the roles of community-based green energy co-operatives in advancing sustainable energy development and energy literacy. Sustainable energy development is firmly rooted in the triple bottom line of environmental, social and economic success, and green energy co-operatives can be a way to help achieve those successes. Green energy co-operatives are structures for providing renewable energy generation or energy conservation practices, both of which have important environmental impacts regarding climate change and pollution levels. Co-operative structures are supported by processes that include local ownership, democracy, participation, community organizing, learning and social change. These processes have a significant social impact by creating a venue for people to be directly involved in the energy industry, by involving learning through participation in a community-based organization, and by advancing energy literacy within the membership and the general public. In regards to the economic impacts, green energy co-operatives foster a local economy and local investment opportunities, which have repercussions regarding building expertise within Ontario's green energy and co-operative development future, and more generally, captures members' interest because they have a direct stake in the co-operative. This thesis shows that green energy co-operatives, like WindShare, play an important role in advancing sustainable energy development, energy literacy and the triple bottom line. Members of WindShare expressed resounding feelings of pride, efficacy and understanding of WindShare's role in sustainable energy. WindShare Co-operative provided the structure whereby members felt a part of the solution in terms of sustainable energy development. Policies and practices at all levels of government should encourage the advancement of green energy co-operatives to support Canada's efforts at public involvement in combating climate change and pollution.

On the weight of indels in genomic distances

PubMed Central

2011-01-01

Background Classical approaches to compute the genomic distance are usually limited to genomes with the same content, without duplicated markers. However, differences in the gene content are frequently observed and can reflect important evolutionary aspects. A few polynomial time algorithms that include genome rearrangements, insertions and deletions (or substitutions) were already proposed. These methods often allow a block of contiguous markers to be inserted, deleted or substituted at once but result in distance functions that do not respect the triangular inequality and hence do not constitute metrics. Results In the present study we discuss the disruption of the triangular inequality in some of the available methods and give a framework to establish an efficient correction for two models recently proposed, one that includes insertions, deletions and double cut and join (DCJ) operations, and one that includes substitutions and DCJ operations. Conclusions We show that the proposed framework establishes the triangular inequality in both distances, by summing a surcharge on indel operations and on substitutions that depends only on the number of markers affected by these operations. This correction can be applied a posteriori, without interfering with the already available formulas to compute these distances. We claim that this correction leads to distances that are biologically more plausible. PMID:22151784

Spatio-temporal variations of carbon dioxide and its gross emission regulated by artificial operation in a typical hydropower reservoir in China.

PubMed

Li, Zhe; Zhang, Zengyu; Xiao, Yan; Guo, Jinsong; Wu, Shengjun; Liu, Jing

2014-05-01

Supersaturation and excess emission of greenhouse gases in freshwater reservoirs have received a great deal of attention in recent years. Although impoundment of reservoirs has been shown to contribute to the net emission of greenhouse gases, reservoir age, geographical distribution, submerged soil type and artificial regulation also have a great impact on their emissions. To examine how large scale reservoir operation impact the water column CO2 and its air-water interface flux, a field study was conducted in 2010 to evaluate potential ecological processes that regulate the partial pressure of CO2 (pCO2) in the water column in the Pengxi River backwater area (PBA), a typical tributary in the Three Gorges Reservoir, China. Measurements of total alkalinity (TA), pH and water temperature were applied to compute the pCO2. And this approach was also validated by calculation of pCO2 from the dissolved inorganic carbon data of samples. Partial least squares (PLS) regression was used to determine how the dynamics of the water pCO2 were related to the available variables. The estimated pCO2 in our sample ranged from 26 to 4,087 μatm in the surface water. During low water operation from July to early September, there was an obvious pCO2 stratification, and pCO2 in the surface was almost unsaturated. This phenomenon was also observed in the spring bloom during discharge period. Conversely, there was no significant pCO2 stratification and the entire water column was supersaturated during high water operation from November to the following February. Significant correlation was observed between the magnitude of pCO2, DO and chlorophyll a, suggesting that phytoplankton dynamics regulate pCO2 in the PBA. The average areal rate of CO2 emissions from the Pengxi River ranged from 18.06 to 48.09 mmol m(-2) day(-1), with an estimated gross CO2 emission from the water surface of 14-37 t day(-1) in this area in 2010. Photosynthesis and respiration rates by phytoplankton might be the dominant processes that regulated pCO2 in the water column. We conclude that pCO2 values in the surface water of Pengxi River could be regarded as potential sources of CO2 to the atmosphere were smaller or similar to those that have been reported for many other reservoirs to date.

The effect of ocean alkalinity and carbon transfer on deep-sea carbonate ion concentration during the past five glacial cycles

NASA Astrophysics Data System (ADS)

Kerr, Joanna; Rickaby, Rosalind; Yu, Jimin; Elderfield, Henry; Sadekov, Aleksey Yu.

2017-08-01

Glacial-interglacial deep Indo-Pacific carbonate ion concentration ([CO32-]) changes were mainly driven by two mechanisms that operated on different timescales: 1) a long-term increase during glaciation caused by a carbonate deposition reduction on shelves (i.e., the coral reef hypothesis), and 2) transient carbonate compensation responses to deep ocean carbon storage changes. To investigate these mechanisms, we have used benthic foraminiferal B/Ca to reconstruct deep-water [CO32-] in cores from the deep Indian and Equatorial Pacific Oceans during the past five glacial cycles. Based on our reconstructions, we suggest that the shelf-to-basin shift of carbonate deposition raised deep-water [CO32-], on average, by 7.3 ± 0.5 (SE) μmol/kg during glaciations. Oceanic carbon reorganisations during major climatic transitions caused deep-water [CO32-] deviations away from the long-term trend, and carbonate compensation processes subsequently acted to restore the ocean carbonate system to new steady state conditions. Deep-water [CO32-] showed similar patterns to sediment carbonate content (%CaCO3) records on glacial-interglacial timescales, suggesting that past seafloor %CaCO3 variations were dominated by deep-water carbonate preservation changes at our studied sites.

Renewable and high efficient syngas production from carbon dioxide and water through solar energy assisted electrolysis in eutectic molten salts

NASA Astrophysics Data System (ADS)

Wu, Hongjun; Liu, Yue; Ji, Deqiang; Li, Zhida; Yi, Guanlin; Yuan, Dandan; Wang, Baohui; Zhang, Zhonghai; Wang, Peng

2017-09-01

Over-reliance on non-renewable fossil fuel leads to steadily increasing concentration of atmospheric CO2, which has been implicated as a critical factor contributing to global warming. The efficient conversion of CO2 into useful product is highly sought after both in academic and industry. Herein, a novel conversion strategy is proposed to one-step transform CO2/H2O into syngas (CO/H2) in molten salt with electrolysis method. All the energy consumption in this system are contributed from sustainable energy sources: concentrated solar light heats molten salt and solar cell supplies electricity for electrolysis. The eutectic Li0.85Na0.61K0.54CO3/nLiOH molten electrolyte is rationally designed with low melting point (<450 °C). The synthesized syngas contains very desirable content of H2 and CO, with tuneable molar ratios (H2/CO) from 0.6 to 7.8, and with an efficient faradaic efficiency of ∼94.5%. The synthesis of syngas from CO2 with renewable energy at a such low electrolytic temperature not only alleviates heat loss, mitigates system corrosion, and heightens operational safety, but also decreases the generation of methane, thus increases the yield of syngas, which is a remarkable technological breakthrough and this work thus represents a stride in sustainable conversion of CO2 to value-added product.

Etude de production et de caracterisation de biocharbons de panic erige (Panicum virgatum L.) obtenus par pyrolyse

NASA Astrophysics Data System (ADS)

Pilon, Guillaume

This research aimed at the production of biomass char under pyrolytic conditions, targeting biochar as soil amendment, while also considering its application as biocoal, either for bioenergy or subsequent upgrading. The production of biomass char was performed using two bench-scale, batch-type, fixed-bed reactors, each with an operating capacity of 1 and 25 gw.b. /batch, respectively. Switchgrass (Panicum virgatum) has been used for the tests. Production conditions studied implied temperatures of 300, 400 and 500 °C with short residence times (2.5 and 5 min). As well, the effect of using CO2 as vector gas has been compared to a common inert environment of N2. The effects of the previously mentioned parameters were correlated with some important physicochemical characteristics of biomass char. Analyses were also performed on complementary pyrolytic products (bio-oil and gas). The biomass char extraction was performed using a Soxhlet and dichloromethane was used as extracting solvent. The extracts were then characterized by GC-MS thus allowing the identification of several compounds. Specific pyrolysis conditions used at 300 °C - N2 with the 1 g/batch reactor, such as high heating rates as well as high convection conditions, presented advantegeous biomass char yields and properties, and, possible torrefaction process productivity improvement (in comparison to reported literature, such as Gilbert et al. [2009]). The char extracts as well as the bio-oils analysis (also performed using GC-MS), all generated from the 25 g/batch reactor, showed major differences among the compounds obtained from the CO2 and N2 environments, respectively. Several compounds observed in the char extracts appeared less concentrated in the CO2 environment vs N2, for the same reaction temperatures. As an example, at 400 °C, furfural was found only in char extracts from N2 environment as compared to the CO2 environment. Among all studied conditions (for both reactors), only naphthalene and naphthalene derivatives constituted the PAHs content, which was only detected for the chars produced at 500 °C. The use of CO2 as pyrolysis vector gas led to a significant difference for every temperature conditions studied for the biomass char as well as for the liquid and gas products. At 300 °C, in CO 2 environment, it is possible to observe a bio-oil production significantly lower than within a N2 environment (18.0 vs 24.6 %; CO2 vs N2 for P<0.002), a result consistent with the biomass char volatile content that was shown to be significantly higher under the same conditions (0.29 vs 0.35 gchar volatiles content/graw biomass; P=0.1). In addition, at 500 °C, the char ash content was observed to be significantly lower in CO 2 than in N2 (P<0.06). Keywords: Pyrolysis, torrefaction, char, biochar, biocoal, CO 2, Soxhlet extractions, characterization.

CO 2 Sequestration and Enhanced Oil Recovery at Depleted Oil/Gas Reservoirs

DOE PAGES

Dai, Zhenxue; Viswanathan, Hari; Xiao, Ting; ...

2017-08-18

This study presents a quantitative evaluation of the operational and technical risks of an active CO 2-EOR project. A set of risk factor metrics is defined to post-process the Monte Carlo (MC) simulations for statistical analysis. The risk factors are expressed as measurable quantities that can be used to gain insight into project risk (e.g. environmental and economic risks) without the need to generate a rigorous consequence structure, which include (a) CO 2 injection rate, (b) net CO 2 injection rate, (c) cumulative CO 2 storage, (d) cumulative water injection, (e) oil production rate, (f) cumulative oil production, (g) cumulativemore » CH 4 production, and (h) CO 2 breakthrough time. The Morrow reservoir at the Farnsworth Unit (FWU) site, Texas, is used as an example for studying the multi-scale statistical approach for CO 2 accounting and risk analysis. A set of geostatistical-based MC simulations of CO 2-oil/gas-water flow and transport in the Morrow formation are conducted for evaluating the risk metrics. A response-surface-based economic model has been derived to calculate the CO 2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO 2 capture and operating expenses reduce, more realizations would be profitable.« less

CO 2 Sequestration and Enhanced Oil Recovery at Depleted Oil/Gas Reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Zhenxue; Viswanathan, Hari; Xiao, Ting

This study presents a quantitative evaluation of the operational and technical risks of an active CO 2-EOR project. A set of risk factor metrics is defined to post-process the Monte Carlo (MC) simulations for statistical analysis. The risk factors are expressed as measurable quantities that can be used to gain insight into project risk (e.g. environmental and economic risks) without the need to generate a rigorous consequence structure, which include (a) CO 2 injection rate, (b) net CO 2 injection rate, (c) cumulative CO 2 storage, (d) cumulative water injection, (e) oil production rate, (f) cumulative oil production, (g) cumulativemore » CH 4 production, and (h) CO 2 breakthrough time. The Morrow reservoir at the Farnsworth Unit (FWU) site, Texas, is used as an example for studying the multi-scale statistical approach for CO 2 accounting and risk analysis. A set of geostatistical-based MC simulations of CO 2-oil/gas-water flow and transport in the Morrow formation are conducted for evaluating the risk metrics. A response-surface-based economic model has been derived to calculate the CO 2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO 2 capture and operating expenses reduce, more realizations would be profitable.« less

IPPF Co-operative Information Service (ICIS). November 1978.

ERIC Educational Resources Information Center

International Planned Parenthood Federation, London (England).

This is a bibliography of family planning material available from the International Planned Parenthood Cooperative Information Service library and documentation services. Entries are made under the following categories: reference books, biographies, family planning and bio-medical science, social sciences related to family planning, international…

Climate: Is the past the key to the future?

NASA Astrophysics Data System (ADS)

Hay, W. W.; DeConto, R. M.; Wold, C. N.

The climate of the Holocene is not well suited to be the baseline for the climate of the planet. It is an interglacial, a state typical of only 10% of the past few million years. It is a time of relative sea-level stability after a rapid 130-m rise from the lowstand during the last glacial maximum. Physical geologic processes are operating at unusual rates and much of the geochemical system is not in a steady state. During most of the Phanerozoic there have been no continental ice sheets on the earth, and the planet's meridional temperature gradient has been much less than it is presently. Major factors influencing climate are insolation, greenhouse gases, paleogeography, and vegetation; the first two are discussed in this paper. Changes in the earth's orbital parameters affect the amount of radiation received from the sun at different latitudes over the course of the year. During the last climate cycle, the waxing and waning of the northern hemisphere continental ice sheets closely followed the changes in summer insolation at the latitude of the northern hemisphere polar circle. The overall intensity of insolation in the northern hemisphere is governed by the precession of the earth's axis of rotation, and the precession and ellipticity of the earth's orbit. At the polar circle a meridional minimum of summer insolation becomes alternately more and less pronounced as the obliquity of the earth's axis of rotation changes. Feedback processes amplify the insolation signal. Greenhouse gases (H2O, CO2, CH4, CFCs) modulate the insolation-driven climate. The atmospheric content of CO2 during the last glacial maximum was approximately 30% less than during the present interglacial. A variety of possible causes for this change have been postulated. The present burning of fossil fuels, deforestation, and cement manufacture since the beginning of the industrial revolution have added CO2 to the atmosphere when its content due to glacial-interglacial variation was already at a maximum. Anthropogenic activity has increased the CO2 content of the atmosphere to 130% of its previous Holocene level, probably higher than at any time during the past few million years. During the Late Cretaceous the atmospheric CO2 content was probably about four times that of the present, the level to which it may rise at the end of the next century. The results of a Campanian (80 Ma) climate simulation suggest that the positive feedback between CO2 and another important greenhouse gas, H2O, raised the earth's temperature to a level where latent heat transport became much more significant than it is presently, and operated efficiently at all latitudes. Atmospheric high- and low-pressure systems were as much the result of variations in the vapor content of the air as of temperature differences. In our present state of knowledge, future climate change is unpredictable because by adding CO2 to the atmosphere we are forcing the climate toward a ``greenhouse'' mode when it is accustomed to moving between the glacial-interglacial ``icehouse'' states that reflect the waxing and waning of ice sheets. At the same time we are replacing freely transpiring C3 plants with water-conserving C4 plants, producing a global vegetation complex that has no past analog. The past climates of the earth cannot be used as a direct guide to what may occur in the future. To understand what may happen in the future we must learn about the first principles of physics and chemistry related to the earth's system. The fundamental mechanisms of the climate system are best explored in simulations of the earth's ancient extreme climates.

Inoculation of soil native cyanobacteria to restore arid degraded soils

NASA Astrophysics Data System (ADS)

Raúl Román Fernández, José; Roncero Ramos, Beatriz; Chamizo de la Piedra, Sonia; Rodríguez Caballero, Emilio; Ángeles Muñoz Martín, M.; Mateo, Pilar; Cantón Castilla, Yolanda

2017-04-01

Restoration projects in semiarid lands often yield poor results. Water scarcity, low soil fertility, and poor soil structure strongly limit the survival and growth of planted seedlings in these areas. Under these conditions, a previous stage that improves edaphic conditions would turn out to a successful plant restoration. By successfully colonizing arid soils, cyanobacteria naturally provide suitable edaphic conditions, enhancing water availability, soil fertility and soil stability. Furthermore, cyanobacteria can be easily isolated and cultured ex-situ to produce high quantities of biomass, representing a potential tool to restore large areas efficiently. The objective of this study was to test the effect of inoculated cyanobacteria on degraded soils at three different semiarid areas from southeast Spain: Tabernas badlands, a limestone quarry located in Gádor, and grazed grassland in Las Amoladeras (Cabo de Gata). Soil native cyanobacteria belonging to three representative N-fixing genera (Nostoc, Scytonema and Tolypothrix) were isolated from such soils and cultured in BG110 medium. Each strain was inoculated (6 g m-2), separately and mixed (all in the same proportion), on Petri dishes with 80 g of each soil. Biocrust development was monitored during 3 months in these soils under laboratory conditions, at a constant temperature of 25oC. During the experiment, two irrigation treatments were applied simulating a dry (180 mm) and a wet (360 mm) rainfall year (average recorded in the study sites). After 3 months, net CO2 flux, spectral response and soil surface microtopography (1 mm spatial resolution) of inoculated and control soils was measured under wet conditions, all of them as a surrogate of biocrust development. Samples of the surface crust were collected in order to determine total soil organic carbon (SOC) content. The inoculated soils showed positive values of net CO2 flux, thus indicating a net CO2 uptake, whereas control soils showed CO2 fluxes closed to zero. This higher CO2 fixation in the inoculated soils was reflected in the higher SOC content found in these soils with respect to the non-inoculated soils. Soil surface roughness increased with biocrust development in the inoculated soils as compared to control soils. From the different treatments, soil inoculation with the mixture of the three strains promoted the highest SOC contents and absorbance at 680 nm (indicative of higher chlorophyll a content) on the three soil types. Therefore, using a consortium of cyanobacteria to inoculate degraded soils seems to be a more promising strategy to restore soils than inoculating individual species. Finally, differences between irrigation treatments were no significant, suggesting that water availability was not a key driver for cyanobacteria development under control laboratory conditions. Our results underline the viability of cyanobacteria inoculation to form an artificial developed biocrust that contribute to CO2 uptake and increase soil fertility which could facilitate further plant cover establishment. However, more studies are necessaries to test the effectiveness of inoculated crust development under field conditions.

Carbon Dioxide Exchange and Acidity Levels in Detached Pineapple, Ananas comosus (L.), Merr., Leaves during the Day at Various Temperatures, Oxygen and Carbon Dioxide Concentrations.

PubMed

Moradshahi, A; Vines, H M; Black, C C

1977-02-01

The effects of temperature, O(2), and CO(2) on titratable acid content and on CO(2) exchange were measured in detached pineapple (Ananas comosus) leaves during the daily 15-hour light period. Comparative measurements were made in air and in CO(2)-free air. Increasing the leaf temperature from 20 to 35 C decreased the total CO(2) uptake in air and slightly increased the total CO(2) released into CO(2)-free air. Between 25 and 35 C, the activation energy for daily acid loss was near 12 kcal mol(-1), but at lower temperatures the activation energy was much greater.Increasing O(2) or decreasing the CO(2) concentration decreased the total CO(2) fixation in air, whereas the total CO(2) released in CO(2)-free air was increased. The total acid content remained constant at 20 C, but it decreased progressively with increasing temperature both in air and in CO(2)-free air. The total acid content at 30 C remained constant in 2% O(2) irrespective of CO(2) concentration. The total acid content decreased in 21 and 50% O(2) as the CO(2) increased from 0 to 300, and 540 mul/l of CO(2). The data indicate that photorespiration is present in pineapple. The lack of acid loss in 2% O(2) suggests that light deacidification is dependent upon respiration and that higher O(2) concentrations are required to saturate deacidification.

Potentials and challenges associated with automated closed dynamic chamber measurements of soil CO2 fluxes

NASA Astrophysics Data System (ADS)

Görres, Carolyn-Monika; Kammann, Claudia; Ceulemans, Reinhart

2015-04-01

Soil respiration fluxes are influenced by natural factors such as climate and soil type, but also by anthropogenic activities in managed ecosystems. As a result, soil CO2 fluxes show a large intra- and interannual as well as intra- and intersite variability. Most of the available soil CO2 flux data giving insights into this variability have been measured with manually closed static chambers, but technological advances in the past 15 years have also led to an increased use of automated closed chamber systems. The great advantage of automated chambers in comparison to manually operated chambers is the higher temporal resolution of the flux data. This is especially important if we want to better understand the effects of short-term events, e.g. fertilization or heavy rainfall, on soil CO2 flux variability. However, the chamber method is an invasive measurement method which can potentially alter soil CO2 fluxes and lead to biased measurement results. In the peer-reviewed literature, many papers compare the field performance and results of different closed static chamber designs, or compare manual chambers with automated chamber systems, to identify potential biases in CO2 flux measurements, and thus help to reduce uncertainties in the flux data. However, inter-comparisons of different automated closed dynamic chamber systems are still lacking. Here we are going to present a field comparison of the most-cited automated chamber system, the LI-8100A Automated Soil Flux System, with the also commercially available Greenhouse Gas Monitoring System AGPS. Both measurement systems were installed side by side at a recently harvested poplar bioenergy plantation (POPFULL, http://uahost.uantwerpen.be/popfull/) from April 2014 until August 2014. The plantation provided optimal comparison conditions with a bare field situation after the harvest and a regrowing canopy resulting in a broad variety of microclimates. Furthermore, the plantation was planted in a double-row system with the row width alternating between 1.50 m and 0.75 m, creating spatial differences in e.g. dry bulk density and soil organic carbon content. The soil CO2 flux data sets were split into four subsets each characterized by different environmental conditions, thus presenting different challenges for the measurement equipment, namely 1) daytime, calm conditions, 2) daytime, windy conditions, 3) nighttime, calm conditions, and 4) nighttime, windy conditions. In parallel to the chamber measurements, soil CO2 concentrations were manually measured in the topsoil. Soil CO2 fluxes calculated from this dataset were used as a reference range of soil CO2 fluxes at the field site. Funding support: ERC Advanced Grant agreement (# 233366) POPFULL under the EC 7th Framework Program (FP7/2007-2013), Flemish Hercules Foundation as Infrastructure contract # ZW09-06, and the Methusalem Program of the Flemish Government.

Laser CO2 tonsillotomy versus argon plasma coagulation (APC) tonsillotomy: A retrospective study with 10-year follow-up.

PubMed

Papaspyrou, Giorgos; Linxweiler, Maximilian; Knöbber, Dirk; Schick, Bernhard; Al Kadah, Basel

2017-01-01

Tonsillotomy is increasingly gaining acceptance as the treatment for tonsillar hyperplasia resulting in obstructive symptoms. The aim of this study was to compare the long-term results of CO 2 laser tonsillotomy with those of argon plasma coagulation (APC) tonsillotomy. The data of 64 children, aged 2-10 years (mean 4.7 years), treated in the Department of Otolaryngology, Head and Neck Surgery, in Homburg, Germany with APC (36 patients) or CO 2 laser (28 patients) for tonsillar hyperplasia between June 2004 and December 2004 were available for analysis. Forty-five (APC: 26 patients, CO 2 : 19 patients) of the 64 patients (70.3%) could be contacted and were available for follow-up in a telephone survey conducted 10 years after surgery. The mean operation time was 17 min (range 10-25 min) in the APC group and 23 min (range 13-32 min) in the CO 2 group (p = 0.0003). No case of intra- or postoperative bleeding was documented. One minor intraoperative complication in the form of a superficial lip burn was documented in the APC group. During the minimum 10 years of follow-up, 1 patient treated with APC underwent a surgical revision because of tonsillar regrowth, whereas in the group of patients treated with CO 2 , no surgical revision was needed. Regarding the parents' assessment of their children's symptoms, 89.4% of the parents of the CO 2 laser group and 84.6% of the parents of the APC group reported that the overall long-term operation results of their children to be "very satisfying." Regarding complications, the need for secondary tonsillectomy, and parents' satisfaction, no statistically significant differences were found. Both CO 2 laser tonsillotomy and APC tonsillotomy are safe procedures leading to very satisfying results with respect to intra- and postoperative complications. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Reasons to Co-Operate: Co-Operative Solutions for Schools

ERIC Educational Resources Information Center

Roach, Patrick

2013-01-01

The NASUWT's landmark agreement with the Schools Co-operative Society has provided a new spur to co-operation, collaboration and collegiality in schools. Against a background of rapid and radical changes to the education landscape, co-operative schools are viewed by many as a means to maintaining public service ethos and values in education. The…

Application of aerobic composting system for space agriculture

NASA Astrophysics Data System (ADS)

Oshima, Tairo; Yoshii, Takahiro; Moriya, Toshiyuki; Yamashita, Masamichi

Composting is a classical technique to decompose organic wastes such as animal bodies, straw, paper, raw sludge, and so on. Compared with burning of wastes, the composting method has many advantages. It is an inexpensive and safer method because of its self-heating without spending extra energy resources. It does not emit toxic pollutants such as dioxin, NOx , and SOx . The composting products can be used as organic fertilizers for agricultural production. Composting is a promising way for digesting organic wastes safely on spaceships or manned exploration on extraterrestrial planets. We have developed a small scale high-temperature composter in order to examine its feasobility to operate food waste disposing facility and fertilizer production in space. This composter has a heated reaction vessel containing compost soil (seed bacteria) provided by a compost factory. To determine the optimal condition for its operation, we analyzed the effect of temperature on metabolic activity (CO2 production rate), and water content. The dynamics of microbial community was studied by polymerase chain reaction - denaturing gradient gel electrophoresis (PCR-DGGE). Water content was maintained to a range between 27% and 40% by continuously adding water. The highest CO2 emission was observed at around 70° C. PCR-DGGE analysis shows that the bacterial community of the compost soil is dramatically changed by changing reaction temperature. We will discuss the application of the composter in space in order to establish the closed recycling loop of bio-elements in space agriculture.

Plant-soil distribution of potentially toxic elements in response to elevated atmospheric CO2.

PubMed

Duval, Benjamin D; Dijkstra, Paul; Natali, Susan M; Megonigal, J Patrick; Ketterer, Michael E; Drake, Bert G; Lerdau, Manuel T; Gordon, Gwyneth; Anbar, Ariel D; Hungate, Bruce A

2011-04-01

The distribution of contaminant elements within ecosystems is an environmental concern because of these elements' potential toxicity to animals and plants and their ability to hinder microbial ecosystem services. As with nutrients, contaminants are cycled within and through ecosystems. Elevated atmospheric CO2 generally increases plant productivity and alters nutrient element cycling, but whether CO2 causes similar effects on the cycling of contaminant elements is unknown. Here we show that 11 years of experimental CO2 enrichment in a sandy soil with low organic matter content causes plants to accumulate contaminants in plant biomass, with declines in the extractable contaminant element pools in surface soils. These results indicate that CO2 alters the distribution of contaminant elements in ecosystems, with plant element accumulation and declining soil availability both likely explained by the CO2 stimulation of plant biomass. Our results highlight the interdependence of element cycles and the importance of taking a broad view of the periodic table when the effects of global environmental change on ecosystem biogeochemistry are considered.

Single-coal-particle combustion in O{sub 2}/N{sub 2} and O{sub 2}/CO{sub 2} environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bejarano, Paula A.; Levendis, Yiannis A.

A fundamental investigation has been conducted on the combustion of single particles of a bituminous coal (45-53, 75-90, and 150-180 {mu}m), of a lignite coal (45-53 and 75-90 {mu}m), and of spherical and monodisperse synthetic chars (43 {mu}m) at increasing O{sub 2} mole fractions in either N{sub 2} or CO{sub 2} balance gases. The synthetic particles were used to facilitate the observation of combustion phenomena with minimum distractions from particle-to-particle variabilities. The laboratory setup consisted of a drop-tube furnace operated at temperatures of 1400 and 1600 K. A calibrated three-color pyrometer, interfaced with the furnace, recorded luminous particle temperature-time profiles.more » Experimental results revealed that coal particles burned at higher mean temperatures and shorter combustion times in O{sub 2}/N{sub 2} than in O{sub 2}/CO{sub 2} environments at analogous oxygen mole fractions. In the case of the bituminous coal used herein and for the experimental combustion conditions tested, measured volatile and char temperatures as in air (21% O{sub 2}) were attained with an oxygen content in the CO{sub 2} mixtures in the neighborhood of 30%. Bituminous coal volatile and char burnout times comparable to those in air (21% O{sub 2}) were attained with oxygen content in the CO{sub 2} mixtures in the range of 30-35%. In the case of the lignite coal burned, the corresponding differences in oxygen mole fractions, which result in similar particle temperatures and burnout times in the two different gas mixtures, were less pronounced. (author)« less

The influence of food supply on the response of Olympia oyster larvae to ocean acidification

NASA Astrophysics Data System (ADS)

Hettinger, A.; Sanford, E.; Hill, T. M.; Hosfelt, J. D.; Russell, A. D.; Gaylord, B.

2013-03-01

Increases in atmospheric carbon dioxide drive accompanying changes in the marine carbonate system as carbon dioxide (CO2) enters seawater and alters its pH (termed "ocean acidification"). However, such changes do not occur in isolation, and other environmental factors have the potential to modulate the consequences of altered ocean chemistry. Given that physiological mechanisms used by organisms to confront acidification can be energetically costly, we explored the potential for food supply to influence the response of Olympia oyster (Ostrea lurida) larvae to ocean acidification. In laboratory experiments, we reared oyster larvae under a factorial combination of pCO2 and food level. High food availability offset the negative consequences of elevated pCO2 on larval shell growth and total dry weight. Low food availability, in contrast, exacerbated these impacts. In both cases, effects of food and pCO2 interacted additively rather than synergistically, indicating that they operated independently. Despite the potential for abundant resources to counteract the consequences of ocean acidification, impacts were never completely negated, suggesting that even under conditions of enhanced primary production and elevated food availability, impacts of ocean acidification may still accrue in some consumers.

The critical role of sodium content on structure, morphology and electrochemical performance of layered P2-type NaxNi0.167Co0.167Mn0.67O2 for sodium ion batteries

NASA Astrophysics Data System (ADS)

Bao, Shuo; Luo, Shaohua; Wang, Zhiyuan; Wang, Qing; Hao, Aimin; Zhang, Yahui; Wang, Yingling

2017-09-01

P2-type manganese-based ternary transition metal oxides have triggered extensive researches as potential cathode materials for sodium ion batteries. However, these kinds of materials display the large difference in electrochemical performance with sodium content varying from 0.45 to 0.8, the relevant investigations on effects of sodium content are insufficient. In this work, we synthesize a series of spherical P2-type cathode materials NaxNi0.167Co0.167Mn0.67O2 with different sodium content (x = 0.45, 0.55, 0.67, 0.8, 0.9, 1) and investigate the effects of sodium content on structure and electrochemical performance. The results reveal that NaxNi0.167Co0.167Mn0.67O2 (x = 0.45, 0.55) consist of P2-phase and P3-phase, while NaxNi0.167Co0.167Mn0.67O2 (x = 0.67, 0.8, 0.9, 1) exhibit pure P2-phase. Na0.45Ni0.167Co0.167Mn0.67O2 delivers an initial discharge capacity of 143 mAh g-1, while a fast capacity decay is observed after 50 cycles. In comparison, Na0.67Ni0.167Co0.167Mn0.67O2 shows excellent cycling stability and rate performance. The significant difference in electrochemical performance is attributed to the initial sodium content, which leads to the existence of P3-phase. Moreover, higher sodium content promotes primary particles to grow larger and thicker, which is not favorable for the diffusion of Na+. Generally, Na0.67Ni0.167Co0.167Mn0.67O2 is favored by suitable sodium content, offers excellent electrochemical performance in terms of capacity, rate performance and cycling stability.

Quantitative multiphase model for hydrothermal liquefaction of algal biomass

DOE PAGES

Li, Yalin; Leow, Shijie; Fedders, Anna C.; ...

2017-01-17

Here, optimized incorporation of hydrothermal liquefaction (HTL, reaction in water at elevated temperature and pressure) within an integrated biorefinery requires accurate models to predict the quantity and quality of all HTL products. Existing models primarily focus on biocrude product yields with limited consideration for biocrude quality and aqueous, gas, and biochar co-products, and have not been validated with an extensive collection of feedstocks. In this study, HTL experiments (300 °C, 30 min) were conducted using 24 different batches of microalgae feedstocks with distinctive feedstock properties, which resulted in a wide range of biocrude (21.3–54.3 dry weight basis, dw%), aqueous (4.6–31.2more » dw%), gas (7.1–35.6 dw%), and biochar (1.3–35.0 dw%) yields. Based on these results, a multiphase component additivity (MCA) model was introduced to predict yields and characteristics of the HTL biocrude product and aqueous, gas, and biochar co-products, with only feedstock biochemical (lipid, protein, carbohydrate, and ash) and elemental (C/H/N) composition as model inputs. Biochemical components were determined to distribute across biocrude product/HTL co-products as follows: lipids to biocrude; proteins to biocrude > aqueous > gas; carbohydrates to gas ≈ biochar > biocrude; and ash to aqueous > biochar. Modeled quality indicators included biocrude C/H/N contents, higher heating value (HHV), and energy recovery (ER); aqueous total organic carbon (TOC) and total nitrogen (TN) contents; and biochar carbon content. The model was validated with HTL data from the literature, the potential to expand the application of this modeling framework to include waste biosolids (e.g., wastewater sludge, manure) was explored, and future research needs for industrial application were identified. Ultimately, the MCA model represents a critical step towards the integration of cultivation models with downstream HTL and biorefinery operations to enable system-level optimization, valorization of co-product streams (e.g., through catalytic hydrothermal gasification and nutrient recovery), and the navigation of tradeoffs across the value chain.« less

CO2 capture by polymeric membranes composed of hyper-branched polymers with dense poly(oxyethylene) comb and poly(amidoamine)

NASA Astrophysics Data System (ADS)

Taniguchi, Ikuo; Wada, Norihisa; Kinugasa, Kae; Higa, Mitsuru

2017-11-01

Due to CO2-philic nature of polyoxyethylene (POE), a dense POE comb structure was tethered onto PMMA backbone to develop CO2 separation membranes over N2. The resulting hyper-branched polymers displayed preferential CO2 permeation. When the polymer thin layer was formed on a high gas permeable polydimethylsiloxane (PDMS) support by a spray-coating manner, the resulting thin film composite (TFC) membranes displayed very high CO2 permeability. However, the CO2 selectivity, which was the permeability ratio of CO2 over N2, was moderate and lower than 50. To enhance the selectivity, poly(amidoamine) (PAMAM) was introduced to the hyper-branched polymers in the CO2-selective layer of the TFC membranes. The CO2 selectivity increased from 47 to 90 with increasing PAMAM content to 40 wt%, and it was drastically enhanced to 350 with PAMAM content of 50 wt%. Differential scanning calorimetry (DSC) and laser microscope revealed formation of PAMAM-rich domain at the higher amine content, where CO2 could readily migrate in comparison to the other polymeric fractions.

Horizon Partitioning of Soil CO2 Sources and their Isotopic Composition (13C) in a Pinus Sylvestris Stand

NASA Astrophysics Data System (ADS)

Goffin, S.; Parent, F.; Plain, C.; Maier, M.; Schack-Kirchner, H.; Aubinet, M.; Longdoz, B.

2012-12-01

The overall aim of this study is to contribute to a better understanding of mechanisms behind soil CO2 efflux using carbon stable isotopes. The approach combines a soil multilayer analysis and the isotopic tool in an in situ study. The specific goal of this work is to quantify the origin and the determinism of 13CO2 and 12CO2 production processes in the different soil layers using the gradient-efflux approach. To meet this, the work includes an experimental setup and a modeling approach. The experimental set up (see also communication of Parent et al., session B008) comprised a combination of different systems, which were installed in a Scot Pine temperate forest at the Hartheim site (Southwestern Germany). Measurements include (i) half hourly vertical profiles of soil CO2 concentration (using soil CO2 probes), soil water content and temperature; (ii) half hourly soil surface CO2 effluxes (automatic chambers); (iii) half hourly isotopic composition of surface CO2 efflux and soil CO2 concentration profile and (iv) estimation of soil diffusivity through laboratory measurements conducted on soil samples taken at several depths. Using the data collected in the experimental part, we developed and used a diffusive transport model to simulate CO2 (13CO2 and 12CO2) flows inside and out of the soil based on Fick's first law. Given the horizontal homogeneity of soil physical parameters in Hartheim, we treated the soil as a structure consisting of distinctive layers of 5 cm thick and expressed the Fick's first law in a discrete formalism. The diffusion coefficient used in each layer was derived from (i) horizon specific relationships, obtained from laboratory measurements, between soil relative diffusivity and its water content and (ii) the soil water content values measured in situ. The concentration profile was obtained from in situ measurements. So, the main model inputs are the profiles of (i) CO2 (13CO2 and 12CO2) concentration, (ii) soil diffusion coefficient and (iii) soil water content. Once the diffusive fluxes deduced at each layer interface, the CO2 (13CO2 and 12CO2) production profile was calculated using the (discretized) mass balance equation in each layer. The results of the Hartheim measurement campaign will be presented. The CO2 source vertical profile and its link with the root and the Carbon organic content distribution will be showed. The dynamic of CO2 sources and their isotopic signature will be linked to climatic variables such soil temperature and soil water content. For example, we will show that the dynamics of CO2 sources was mainly related to temperature while changing of isotopic signature was more correlated to soil moisture.

Beyond clay: Towards an improved set of variables for predicting soil organic matter content

USGS Publications Warehouse

Rasmussen, Craig; Heckman, Katherine; Wieder, William R.; Keiluweit, Marco; Lawrence, Corey R.; Berhe, Asmeret Asefaw; Blankinship, Joseph C.; Crow, Susan E.; Druhan, Jennifer; Hicks Pries, Caitlin E.; Marin-Spiotta, Erika; Plante, Alain F.; Schadel, Christina; Schmiel, Joshua P.; Sierra, Carlos A.; Thompson, Aaron; Wagai, Rota

2018-01-01

Improved quantification of the factors controlling soil organic matter (SOM) stabilization at continental to global scales is needed to inform projections of the largest actively cycling terrestrial carbon pool on Earth, and its response to environmental change. Biogeochemical models rely almost exclusively on clay content to modify rates of SOM turnover and fluxes of climate-active CO2 to the atmosphere. Emerging conceptual understanding, however, suggests other soil physicochemical properties may predict SOM stabilization better than clay content. We addressed this discrepancy by synthesizing data from over 5,500 soil profiles spanning continental scale environmental gradients. Here, we demonstrate that other physicochemical parameters are much stronger predictors of SOM content, with clay content having relatively little explanatory power. We show that exchangeable calcium strongly predicted SOM content in water-limited, alkaline soils, whereas with increasing moisture availability and acidity, iron- and aluminum-oxyhydroxides emerged as better predictors, demonstrating that the relative importance of SOM stabilization mechanisms scales with climate and acidity. These results highlight the urgent need to modify biogeochemical models to better reflect the role of soil physicochemical properties in SOM cycling.

Zeolites for CO2-CO-O2 Separation to Obtain CO2-Neutral Fuels.

PubMed

Perez-Carbajo, Julio; Matito-Martos, Ismael; Balestra, Salvador R G; Tsampas, Mihalis N; van de Sanden, Mauritius C M; Delgado, José A; Águeda, V Ismael; Merkling, Patrick J; Calero, Sofia

2018-06-20

Carbon dioxide release has become an important global issue due to the significant and continuous rise in atmospheric CO 2 concentrations and the depletion of carbon-based energy resources. Plasmolysis is a very energy-efficient process for reintroducing CO 2 into energy and chemical cycles by converting CO 2 into CO and O 2 utilizing renewable electricity. The bottleneck of the process is that CO remains mixed with O 2 and residual CO 2 . Therefore, efficient gas separation and recuperation are essential for obtaining pure CO, which, via water gas shift and Fischer-Tropsch reactions, can lead to the production of CO 2 -neutral fuels. The idea behind this work is to provide a separation mechanism based on zeolites to optimize the separation of carbon dioxide, carbon monoxide, and oxygen under mild operational conditions. To achieve this goal, we performed a thorough screening of available zeolites based on topology and adsorptive properties using molecular simulation and ideal adsorption solution theory. FAU, BRE, and MTW are identified as suitable topologies for these separation processes. FAU can be used for the separation of carbon dioxide from carbon monoxide and oxygen and BRE or MTW for the separation of carbon monoxide from oxygen. These results are reinforced by pressure swing adsorption simulations at room temperature combining adsorption columns with pure silica FAU zeolite and zeolite BRE at a Si/Al ratio of 3. These zeolites have the added advantage of being commercially available.

A Full-Featured User Friendly CO 2-EOR and Sequestration Planning Software

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savage, Bill

A Full-Featured, User Friendly CO 2-EOR and Sequestration Planning Software This project addressed the development of an integrated software solution that includes a graphical user interface, numerical simulation, visualization tools and optimization processes for reservoir simulation modeling of CO 2-EOR. The objective was to assist the industry in the development of domestic energy resources by expanding the application of CO 2-EOR technologies, and ultimately to maximize the CO 2} sequestration capacity of the U.S. The software resulted in a field-ready application for the industry to address the current CO 2-EOR technologies. The software has been made available to the publicmore » without restrictions and with user friendly operating documentation and tutorials. The software (executable only) can be downloaded from NITEC’s website at www.nitecllc.com. This integrated solution enables the design, optimization and operation of CO 2-EOR processes for small and mid-sized operators, who currently cannot afford the expensive, time intensive solutions that the major oil companies enjoy. Based on one estimate, small oil fields comprise 30% of the of total economic resource potential for the application of CO 2-EOR processes in the U.S. This corresponds to 21.7 billion barrels of incremental, technically recoverable oil using the current “best practices”, and 31.9 billion barrels using “next-generation” CO 2-EOR techniques. The project included a Case Study of a prospective CO 2-EOR candidate field in Wyoming by a small independent, Linc Energy Petroleum Wyoming, Inc. NITEC LLC has an established track record of developing innovative and user friendly software. The Principle Investigator is an experienced manager and engineer with expertise in software development, numerical techniques, and GUI applications. Unique, presently-proprietary NITEC technologies have been integrated into this application to further its ease of use and technical functionality.« less

Integrated biogas upgrading and hydrogen utilization in an anaerobic reactor containing enriched hydrogenotrophic methanogenic culture.

PubMed

Luo, Gang; Angelidaki, Irini

2012-11-01

Biogas produced by anaerobic digestion, is mainly used in a gas motor for heat and electricity production. However, after removal of CO(2) , biogas can be upgraded to natural gas quality, giving more utilization possibilities, such as utilization as autogas, or distant utilization by using the existing natural gas grid. The current study presents a new biological method for biogas upgrading in a separate biogas reactor, containing enriched hydrogenotrophic methanogens and fed with biogas and hydrogen. Both mesophilic- and thermophilic anaerobic cultures were enriched to convert CO(2) to CH(4) by addition of H(2) . Enrichment at thermophilic temperature (55°C) resulted in CO(2) and H(2) bioconversion rate of 320 mL CH(4) /(gVSS h), which was more than 60% higher than that under mesophilic temperature (37°C). Different dominant species were found at mesophilic- and thermophilic-enriched cultures, as revealed by PCR-DGGE. Nonetheless, they all belonged to the order Methanobacteriales, which can mediate hydrogenotrophic methanogenesis. Biogas upgrading was then tested in a thermophilic anaerobic reactor under various operation conditions. By continuous addition of hydrogen in the biogas reactor, high degree of biogas upgrading was achieved. The produced biogas had a CH(4) content, around 95% at steady-state, at gas (mixture of biogas and hydrogen) injection rate of 6 L/(L day). The increase of gas injection rate to 12 L/(L day) resulted in the decrease of CH(4) content to around 90%. Further study showed that by decreasing the gas-liquid mass transfer by increasing the stirring speed of the mixture the CH(4) content was increased to around 95%. Finally, the CH(4) content around 90% was achieved in this study with the gas injection rate as high as 24 L/(L day). Copyright © 2012 Wiley Periodicals, Inc.

Identification and expression of fructose-1,6-bisphosphate aldolase genes and their relations to oil content in developing seeds of tea oil tree (Camellia oleifera).

PubMed

Zeng, Yanling; Tan, Xiaofeng; Zhang, Lin; Jiang, Nan; Cao, Heping

2014-01-01

Tea oil tree (Camellia oleifera, Co) provides a fine edible oil source in China. Tea oil from the seeds is very beneficial to human health. Fructose-1,6-bisphosphate aldolase (FBA) hydrolyzes fructose-1,6-bisphosphate into dihydroxyacetone phosphate and glyceraldehyde 3-phosphate, two critical metabolites for oil biosynthesis. The objectives of this study were to identify FBA genes and investigate the relationship between FBA gene expression and oil content in developing seeds of tea oil tree. In this paper, four developmentally up-regulated CoFBA genes were identified in Camellia oleifera seeds based on the transcriptome from two seed developmental stages corresponding to the initiation and peak stages of lipid biosynthesis. The expression of CoFBA genes, along with three key oil biosynthesis genes CoACP, CoFAD2 and CoSAD were analyzed in seeds from eight developmental stages by real-time quantitative PCR. The oil content and fatty acid composition were also analyzed. The results showed that CoFBA and CoSAD mRNA levels were well-correlated with oil content whereas CoFAD2 gene expression levels were correlated with fatty acid composition in Camellia seeds. We propose that CoFBA and CoSAD are two important factors for determining tea oil yield because CoFBA gene controls the flux of key intermediates for oil biosynthesis and CoSAD gene controls the synthesis of oleic acid, which accounts for 80% of fatty acids in tea oil. These findings suggest that tea oil yield could be improved by enhanced expression of CoFBA and CoSAD genes in transgenic plants.

Hardwood biochar and manure co-application to a calcareous soil.

PubMed

Ippolito, J A; Stromberger, M E; Lentz, R D; Dungan, R S

2016-01-01

Biochar may affect the mineralization rate of labile organic C sources such as manures via microbial community shifts, and subsequently affect nutrient release. In order to ascertain the positive or negative priming effect of biochar on manure, dairy manure (2% by wt.) and a hardwood-based, fast pyrolysis biochar were applied (0%, 1%, 2%, and 10% by wt.) to a calcareous soil. Destructive sampling occurred at 1, 2, 3, 4, 6 and 12 months to monitor for changes in soil chemistry, water content, microbial respiration, bacterial populations, and microbial community structure. Overall results showed that increasing biochar application rate improved the soil water content, which may be beneficial in limited irrigation or rainfall areas. Biochar application increased soil organic C content and plant-available Fe and Mn, while a synergistic biochar-manure effect increased plant-available Zn. Compared to the other rates, the 10% biochar application lowered concentrations of NO3-N; effects appeared masked at lower biochar rates due to manure application. Over time, soil NO3-N increased likely due to manure N mineralization, yet soil NO3-N in the 10% biochar rate remained lower as compared to other treatments. In the presence of manure, only the 10% biochar application caused subtle microbial community structure shifts by increasing the relative amounts of two fatty acids associated with Gram-negative bacteria and decreasing Gram-positive bacterial fatty acids, each by ∼1%. Our previous findings with biochar alone suggested an overall negative priming effect with increasing biochar application rates, yet when co-applied with manure the negative priming effect was eliminated. Published by Elsevier Ltd.

A salt oscillator in the glacial Atlantic? 1. The concept

NASA Astrophysics Data System (ADS)

Broecker, Wallace S.; Bond, Gerard; Klas, Millie; Bonani, Georges; Wolfli, Willy

1990-08-01

As shown by the work of Dansgaard and his colleagues, climate oscillations of one or so millennia duration punctuate much of glacial section of the Greenland ice cores. These oscillations are characterized by 5°C air temperature changes, severalfold dust content changes and 50 ppm CO2 changes. Both the temperature and CO2 change are best explained by changes in the mode of operation of the ocean. In this paper we provide evidence which suggests that oscillations in surface water conditions of similar duration are present in the record from a deep sea core at 50°N. Based on this finding, we suggest that the Greenland climate changes are driven by oscillations in the salinity of the Atlantic Ocean which modulate the strength of the Atlantic's conveyor circulation.

Structural and magnetic properties of FeCoC system obtained by mechanical alloying

NASA Astrophysics Data System (ADS)

Rincón Soler, A. I.; Rodríguez Jacobo, R. R.; Medina Barreto, M. H.; Cruz-Muñoz, B.

2017-11-01

Fe96-XCoXC4 (x = 0, 10, 20, 30, 40 at. %) alloys were obtained by mechanical alloying of Fe, C and Co powders using high-energy milling. The structural and magnetic properties of the alloy system were analyzed by X-ray diffraction, Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM) and Mössbauer Spectrometry at room temperature. The X-ray diffraction patterns showed a BCC-FeCoC structure phase for all samples, as well as a lattice parameter that slightly decreases with Co content. The saturation magnetization and coercive field were analyzed as a function of Co content. The Mössbauer spectra were fitted with a hyperfine magnetic field distribution showing the ferromagnetic behavior and the disordered character of the samples. The mean hyperfine magnetic field remained nearly constant (358 T) with Co content.

Undegassed Carbon Content from a Highly Depleted Segment of the Mid-Atlantic Ridge (1-5°S): Evidence from Melt Inclusions

NASA Astrophysics Data System (ADS)

Le Voyer, M.; Kelley, K. A.; Cottrell, E.; Hauri, E. H.

2014-12-01

As carbon solubility is low in basalts, MORB contain little dissolved CO2 (189±61 ppm, 1σ, n=600 [1]). A global negative correlation between CO2/Nb (proxy for amount of CO2 lost by degassing) and Ba/La (proxy for source enrichment) indicates that depleted MORB are less affected by degassing than enriched MORB: CO2/Nb ratios range from 0-100 for samples with Ba/La>4, while CO2/Nb range from 50 to 400 for samples with Ba/La<4 [1]. To assess the CO2 content of undegassed MORB, we analyzed the volatile content of 70 olivine-hosted, glassy melt inclusions (MIs) from four basalts dredged along MAR 1-5°S, a ridge segment that produces highly depleted MORB in terms of trace element enrichment and radiogenic isotopes [2, 3]. MIs contain CO2 contents (180-1420 ppm) that are higher than their respective matrix glasses (130-220 ppm, typical for vapor-saturated melts erupted at 3-5 km b.s.l.). One of the four dredges (EN061 5D-3Ag) contains MIs that do not exhibit shrinkage bubbles. For this sample only, we find a positive correlation between the CO2 content (240-770 ppm) and the Cl content (6-20 ppm) of the MIs that is not found in the matrix glasses (see Fig.). We infer that the correlation between CO2 and Cl, both highly incompatible in silicate minerals during fractional crystallization, is strong evidence for vapor-undersaturation, as any CO2 degassing would have erased the correlation. Together with MIs from the Siqueiros Fracture Zone [4] and from northern Iceland [5], the MIs from EN061 5D-3Ag may represent another occurrence of carbon-undersaturated MORB. Our results will be used to model the primary carbon content of MORB and of the depleted upper mantle. Note that the average Cl content of the matrix glasses (20±1 ppm) is higher than those of the MIs (12±3 ppm, see Fig.). This indicates either that the matrix glasses assimilated a small amount of seawater Cl, or that the MIs are all more depleted than the matrix glass. We will acquire major and trace element data in order to further investigate the origin of the low Cl and high CO2 contents in these MIs. Ref. [1] Le Voyer et al. 2014 Goldschmidt abstr. [2] Schilling et al. 1994 JGR 99 [3] Kelley et al. 2013 G3 [4] Saal et al. 2002 Nature 419 [5] Hauri and Saal 2009 EOS Fall suppl. AGU abstr.

Muon Tomography for Geological Repositories.

NASA Astrophysics Data System (ADS)

Woodward, D.; Kudryavtsev, V.; Gluyas, J.; Clark, S. J.; Thompson, L. F.; Klinger, J.; Spooner, N. J.; Blackwell, T. B.; Pal, S.; Lincoln, D. L.; Paling, S. M.; Mitchell, C. N.; Benton, C.; Coleman, M. L.; Telfer, S.; Cole, A.; Nolan, S.; Chadwick, P.

2015-12-01

Cosmic-ray muons are subatomic particles produced in the upper atmosphere in collisions of primary cosmic rays with atoms in air. Due to their high penetrating power these muons can be used to image the content (primarily density) of matter they pass through. They have already been used to image the structure of pyramids, volcanoes and other objects. Their applications can be extended to investigating the structure of, and monitoring changes in geological formations and repositories, in particular deep subsurface sites with stored CO2. Current methods of monitoring subsurface CO2, such as repeat seismic surveys, are episodic and require highly skilled personnel to operate. Our simulations based on simplified models have previously shown that muon tomography could be used to continuously monitor CO2 injection and migration and complement existing technologies. Here we present a simulation of the monitoring of CO2 plume evolution in a geological reservoir using muon tomography. The stratigraphy in the vicinity of the reservoir is modelled using geological data, and a numerical fluid flow model is used to describe the time evolution of the CO2 plume. A planar detection region with a surface area of 1000 m2 is considered, at a vertical depth of 776 m below the seabed. We find that one year of constant CO2 injection leads to changes in the column density of about 1%, and that the CO2 plume is already resolvable with an exposure time of less than 50 days. The attached figure show a map of CO2 plume in angular coordinates as reconstructed from observed muons. In parallel with simulation efforts, a small prototype muon detector has been designed, built and tested in a deep subsurface laboratory. Initial calibrations of the detector have shown that it can reach the required angular resolution for muon detection. Stable operation in a small borehole within a few months has been demonstrated.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Córdoba, Patricia, E-mail: pc247@hw.ac.uk; Maroto-Valer, M.; Delgado, Miguel Angel

The work presented here reports the first study in which the speciation, behaviour and fate of mercury (Hg) have been evaluated under oxy-fuel combustion at the largest oxy-Pulverised Coal Combustion (oxy-PCC) demonstration plant to date during routine operating conditions and partial exhaust flue gas re-circulation to the boiler. The effect of the CO{sub 2}-rich flue gas re-circulation on Hg has also been evaluated. Results reveal that oxy-PCC operational conditions play a significant role on Hg partitioning and fate because of the continuous CO{sub 2}-rich flue gas re-circulations to the boiler. Mercury escapes from the cyclone in a gaseous form asmore » Hg{sup 2+} (68%) and it is the prevalent form in the CO{sub 2}-rich exhaust flue gas (99%) with lower proportions of Hg{sup 0} (1.3%). The overall retention rate for gaseous Hg is around 12%; Hg{sup 0} is more prone to be retained (95%) while Hg{sup 2+} shows a negative efficiency capture for the whole installation. The negative Hg{sup 2+} capture efficiencies are due to the continuous CO{sub 2}-rich exhaust flue gas recirculation to the boiler with enhanced Hg contents. Calculations revealed that 44 mg of Hg were re-circulated to the boiler as a result of 2183 re-circulations of CO{sub 2}-rich flue gas. Especial attention must be paid to the role of the CO{sub 2}-rich exhaust flue gas re-circulation to the boiler on the Hg enrichment in Fly Ashes (FAs). - Highlights: • The fate of gaseous Hg has been evaluated under oxy-fuel combustion. • The Hg oxidation process is enhanced in CO{sub 2}-rich flue gas recirculation. • Hg{sup 2+} is the prevalent gas species in the CO{sub 2}-rich exhaust flue gas. • Hg{sup 2+}{sub (g)} shows a negative efficiency capture for the whole installation. • Especial attention must be paid to the Hg enrichment in Fly Ashes.« less

Synthesis of FeCoNi nanoparticles by galvanostatic technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budi, Setia, E-mail: setiabudi@unj.ac.id; Department of Chemistry, Faculty of Mathematics and Sciences, Universitas Negeri Jakarta, Jl. Pemuda No.10, Rawamangun, Jakarta 13220; Hafizah, Masayu Elita

Soft magnetic nanoparticles of FeCoNi have been becoming interesting objects for many researchers due to its potential application in electronic devices. One of the most promising methods for material preparation is the electrodeposition which capable of growing nanoparticles alloy directly onto the substrate. In this paper, we report our electrodeposition studies on nanoparticles synthesis using galvanostatic electrodeposition technique. Chemical composition of the synthesized FeCoNi was successfully controlled through the adjustment of the applied currents. It is revealed that the content of each element, obtained from quantitative analysis using atomic absorption spectrometer (AAS), could be modified by the adjustment of currentmore » in which Fe and Co content decreased at larger applied currents, while Ni content increased. The nanoparticles of Co-rich FeCoNi and Ni-rich FeCoNi were obtained from sulphate electrolyte at the range of applied current investigated in this work. Broad diffracted peaks in the X-ray diffractograms indicated typical nanostructures of the solid solution of FeCoNi.« less

Use of a CO{sub 2} pellet non-destructive cleaning system to decontaminate radiological waste and equipment in shielded hot cells at the Bettis Atomic Power Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bench, T.R.

1997-05-01

This paper details how the Bettis Atomic Power Laboratory modified and utilized a commercially available, solid carbon dioxide (CO{sub 2}) pellet, non-destructive cleaning system to support the disposition and disposal of radioactive waste from shielded hot cells. Some waste materials and equipment accumulated in the shielded hot cells cannot be disposed directly because they are contaminated with transuranic materials (elements with atomic numbers greater than that of uranium) above waste disposal site regulatory limits. A commercially available CO{sub 2} pellet non-destructive cleaning system was extensively modified for remote operation inside a shielded hot cell to remove the transuranic contaminants frommore » the waste and equipment without generating any secondary waste in the process. The removed transuranic contaminants are simultaneously captured, consolidated, and retained for later disposal at a transuranic waste facility.« less

Investigation of Desiccants and CO2 Sorbents for Exploration Systems 2016-2017

NASA Technical Reports Server (NTRS)

Knox, James C.; Watson, David W.; Giesy, Timothy J.; Cmarik, Gregory E.; Miller, Lee A.

2017-01-01

NASA has embarked on the mission to enable humans to explore deep space, including the goal of sending humans to Mars. This journey will require significant developments in a wide range of technical areas as resupply and early return are not possible. Additionally, mass, power, and volume must be minimized for all phases to maximize propulsion availability. Among the critical areas identified for development are life support systems, which will require increases in reliability as well as reduce resource usage. Two primary points for reliability are the mechanical stability of sorbent pellets and recovery of CO2 sorbent productivity after off-nominal events. In this paper, we discuss the present efforts towards screening and characterizing commercially-available sorbents for extended operation in desiccant and CO2 removal beds. With minimized dusting as the primary criteria, a commercial 13X zeolite was selected and tested for performance and risk.

Bacterial community shift for monitoring the co-composting of oil palm empty fruit bunch and palm oil mill effluent anaerobic sludge.

PubMed

Zainudin, Mohd Huzairi Mohd; Ramli, Norhayati; Hassan, Mohd Ali; Shirai, Yoshihito; Tashiro, Kosuke; Sakai, Kenji; Tashiro, Yukihiro

2017-06-01

A recently developed rapid co-composting of oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) anaerobic sludge is beginning to attract attention from the palm oil industry in managing the disposal of these wastes. However, a deeper understanding of microbial diversity is required for the sustainable practice of the co-compositing process. In this study, an in-depth assessment of bacterial community succession at different stages of the pilot scale co-composting of OPEFB-POME anaerobic sludge was performed using 454-pyrosequencing, which was then correlated with the changes of physicochemical properties including temperature, oxygen level and moisture content. Approximately 58,122 of 16S rRNA gene amplicons with more than 500 operational taxonomy units (OTUs) were obtained. Alpha diversity and principal component analysis (PCoA) indicated that bacterial diversity and distributions were most influenced by the physicochemical properties of the co-composting stages, which showed remarkable shifts of dominant species throughout the process. Species related to Devosia yakushimensis and Desemzia incerta are shown to emerge as dominant bacteria in the thermophilic stage, while Planococcus rifietoensis correlated best with the later stage of co-composting. This study proved the bacterial community shifts in the co-composting stages corresponded with the changes of the physicochemical properties, and may, therefore, be useful in monitoring the progress of co-composting and compost maturity.

Evaporite Caprock Integrity. An experimental study of reactive mineralogy and pore-scale heterogeneity during brine-CO 2 exposure

DOE PAGES

Smith, Megan M.; Sholokhova, Yelena; Hao, Yue; ...

2012-07-25

Characterization and geochemical data are presented from a core-flooding experiment on a sample from the Three Fingers evaporite unit forming the lower extent of caprock at the Weyburn-Midale reservoir, Canada. This low-permeability sample was characterized in detail using X-ray computed microtomography before and after exposure to CO 2-acidified brine, allowing mineral phase and voidspace distributions to be quantified in three dimensions. Solution chemistry indicated that CO 2-acidified brine preferentially dissolved dolomite until saturation was attained, while anhydrite remained unreactive. Dolomite dissolution contributed to increases in bulk permeability through the formation of a localized channel, guided by microfractures as well asmore » porosity and reactive phase distributions aligned with depositional bedding. An indirect effect of carbonate mineral reactivity with CO 2-acidified solution is voidspace generation through physical transport of anhydrite freed from the rock matrix following dissolution of dolomite. The development of high permeability fast pathways in this experiment highlights the role of carbonate content and potential fracture orientations in evaporite caprock formations considered for both geologic carbon sequestration and CO 2-enhanced oil recovery operations.« less

A spectroscopic transfer standard for accurate atmospheric CO measurements

NASA Astrophysics Data System (ADS)

Nwaboh, Javis A.; Li, Gang; Serdyukov, Anton; Werhahn, Olav; Ebert, Volker

2016-04-01

Atmospheric carbon monoxide (CO) is a precursor of essential climate variables and has an indirect effect for enhancing global warming. Accurate and reliable measurements of atmospheric CO concentration are becoming indispensable. WMO-GAW reports states a compatibility goal of ±2 ppb for atmospheric CO concentration measurements. Therefore, the EMRP-HIGHGAS (European metrology research program - high-impact greenhouse gases) project aims at developing spectroscopic transfer standards for CO concentration measurements to meet this goal. A spectroscopic transfer standard would provide results that are directly traceable to the SI, can be very useful for calibration of devices operating in the field, and could complement classical gas standards in the field where calibration gas mixtures in bottles often are not accurate, available or stable enough [1][2]. Here, we present our new direct tunable diode laser absorption spectroscopy (dTDLAS) sensor capable of performing absolute ("calibration free") CO concentration measurements, and being operated as a spectroscopic transfer standard. To achieve the compatibility goal stated by WMO for CO concentration measurements and ensure the traceability of the final concentration results, traceable spectral line data especially line intensities with appropriate uncertainties are needed. Therefore, we utilize our new high-resolution Fourier-transform infrared (FTIR) spectroscopy CO line data for the 2-0 band, with significantly reduced uncertainties, for the dTDLAS data evaluation. Further, we demonstrate the capability of our sensor for atmospheric CO measurements, discuss uncertainty calculation following the guide to the expression of uncertainty in measurement (GUM) principles and show that CO concentrations derived using the sensor, based on the TILSAM (traceable infrared laser spectroscopic amount fraction measurement) method, are in excellent agreement with gravimetric values. Acknowledgement Parts of this work have been carried out within the European Metrology Research Programme (EMRP) ENV52 project-HIGHGAS (Metrology for high-impact greenhouse gases). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. References [1] EMRP project ENV52-HIGHGAS (Metrology for high-impact greenhouse gases), available at: http://www.euramet.org/. [2] J. Nwaboh, A. Manninen, J. Mohn, J. C. Petersen, O. Werhahn, and V.Ebert, European Geosciences Union General Assembly 2015, EGU2015-13542, 2015, Vienna Austria

40 CFR 98.446 - Data reporting requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... receive CO2 in containers, report: (1) The mass (in metric tons) or volume at standard conditions (in standard cubic meters) of contents in containers received in each quarter. (2) The concentration of CO2 of contents in containers (volume or wt. percent CO2 expressed as a decimal fraction) in each quarter. (3) The...

40 CFR 98.446 - Data reporting requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... receive CO2 in containers, report: (1) The mass (in metric tons) or volume at standard conditions (in standard cubic meters) of contents in containers received in each quarter. (2) The concentration of CO2 of contents in containers (volume or wt. percent CO2 expressed as a decimal fraction) in each quarter. (3) The...

40 CFR 98.446 - Data reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... receive CO2 in containers, report: (1) The mass (in metric tons) or volume at standard conditions (in standard cubic meters) of contents in containers received in each quarter. (2) The concentration of CO2 of contents in containers (volume or wt. percent CO2 expressed as a decimal fraction) in each quarter. (3) The...

40 CFR 98.446 - Data reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... receive CO2 in containers, report: (1) The mass (in metric tons) or volume at standard conditions (in standard cubic meters) of contents in containers received in each quarter. (2) The concentration of CO2 of contents in containers (volume or wt. percent CO2 expressed as a decimal fraction) in each quarter. (3) The...

Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

Treesearch

T. G. Soares Neto; J. A. Carvalho; C. A. G. Veras; E. C. Alvarado; R. Gielow; E. N. Lincoln; T. J. Christian; R. J. Yokelson; J. C. Santos

2009-01-01

Biomass consumption and CO2, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48% and the estimated average moisture content of fresh biomass was 42% on...

Elevated CO2 concentration impacts cell wall polysaccharide composition of green microalgae of the genus Chlorella.

PubMed

Cheng, Y-S; Labavitch, J M; VanderGheynst, J S

2015-01-01

The effect of CO2 concentration on the relative content of starch, lipid and cell wall carbohydrates in microalgal biomass was investigated for the four following Chlorella strains: C. vulgaris (UTEX 259), C. sorokiniana (UTEX 2805), C. minutissima (UTEX 2341) and C. variabilis (NC64A). Each strain had a different response to CO2 concentration. The starch content was higher in UTEX259 and NC64A cultured with 2% CO2 in the air supply than in cells cultured with ca. 0·04% CO2 (ambient air), while starch content was not affected for UTEX 2805 and UTEX 2341. The lipid content was higher in Chlorella minutissima UTEX 2341 cultured in 2% CO2 than in cells cultured in ambient air, but was unchanged for the other three strains. All four Chlorella strains tended to have a higher percentage of uronic acids and lower percentage of neutral sugars in their cell wall polysaccharide complement when grown with 2% CO2 supply. Although the percentage of neutral sugars in the cell walls varied with CO2 concentration, the relative proportions of different neutral sugar constituents remained constant for both CO2 conditions. The results demonstrate the importance of considering the effects of CO2 on the cell wall carbohydrate composition of microalgae. Microalgae have the potential to produce products that will reduce society's reliance on fossil fuels and address challenges related to food and feed production. An overlooked yet industrially relevant component of microalgae are their cell walls. Cell wall composition affects cell flocculation and the recovery of intracellular products. In this study, we show that increasing CO2 level results in greater cell wall polysaccharide and uronic acid content in the cell walls of three strains of microalgae. The results have implications on the management of systems for the capture of CO2 and production of fuels, chemicals and food from microalgae. © 2014 The Society for Applied Microbiology.

Structure and Dynamics of Forsterite-scCO2/H2O Interfaces as a Function of Water Content

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerisit, Sebastien N.; Weare, John H.; Felmy, Andrew R.

Molecular dynamics (MD) simulations of forsterite surfaces in contact with supercritical carbon dioxide (scCO2) fluids of varying water content were performed to determine the partition of water between the scCO2 fluid and the mineral surface, the nature of CO2 and H2O bonding at the interface, and the regions of the interface that may be conducive to HxCO3(2-x)- formation. Calculations of the free energy of the associative adsorption of water onto the (010) forsterite surface from the scCO2 phase indicated that the formation of a water film up to three-monolayer thick can be exothermic even for water contents below the watermore » saturation concentration of the scCO2 fluid. In MD simulations of scCO2/H2O mixtures in contact with the (010) forsterite surface, H2O was found to readily displace CO2 at the surface and, therefore, CO2 directly contacted the surface only for water coverages below two monolayers. For thicker water films, a two-monolayer hydration layer formed that CO2 could not penetrate. Simulations of the hydroxylated (010) surface and of the (011) surface suggested that this conclusion can be extended to forsterite surfaces with different surface structures and/or compositions. The density, diffusion, and degree of hydration of CO2 as well as the extent of CO2/H2O mixing at the interface were all predicted to depend strongly on the thickness of the water-rich film, i.e., on the water content of the scCO2 fluid.« less

High repetition rate sealed CO2 TEA lasers using heterogeneous catalysts

NASA Astrophysics Data System (ADS)

Price, H. T.; Shaw, S. R.

1987-04-01

The significant operational advantages offered by CO2 lasers, operating in the 10.6 micron region of the spectrum, over current solid state lasers, emitting in the near IR region, have prompted increased interest in the development of compact, reliable, rugged CO2 laser sources. Perhaps the most critical aspect associated with achieving a laser compatible with military use is the development of lasers which require no gas replenishment. Sealed, single shot, CO2 TEA lasers have been available for a number of years. Stark et al were first to demonstrate reliable sealed operation in single shot CO2 TEA lasers in 1975 using gas catalysis. GEC Avionics reported the compact, environmentally qualified, MKIII CO2 TEA laser with a pulse life of greater than 10 to the 6th power pulses in 1980. A sealed laser lifetime of greater than 10 to the 6th power pulses is acceptable for single shot cases, such as direct detection rangefinders for tank laser sights. However, in many other applications, such as tracking of fast moving targets, it is essential that a repetition rate of typically 30Hz to 100Hz is employed. In such cases, a pulse lifetime of 10 to the 6th power pulses is no longer sufficient and a minimum pulse lifetime 10 to the 7th power pulses is essential to ensure a useful service life. In 1983 Stark el al described a sealed, 100Hz CO2 TEA laser, with a life of greater than 2.6 x 10 to the 6th power, which employed heterogeneous catalysis. Following this pioneering work, GEC Avionics has been engaged in the development of sealed high repetition rate lasers with a pulse lifetime of 20 million pulses.

High repetition rate sealed CO2 TEA lasers using heterogeneous catalysts

NASA Technical Reports Server (NTRS)

Price, H. T.; Shaw, S. R.

1987-01-01

The significant operational advantages offered by CO2 lasers, operating in the 10.6 micron region of the spectrum, over current solid state lasers, emitting in the near IR region, have prompted increased interest in the development of compact, reliable, rugged CO2 laser sources. Perhaps the most critical aspect associated with achieving a laser compatible with military use is the development of lasers which require no gas replenishment. Sealed, single shot, CO2 TEA lasers have been available for a number of years. Stark et al were first to demonstrate reliable sealed operation in single shot CO2 TEA lasers in 1975 using gas catalysis. GEC Avionics reported the compact, environmentally qualified, MKIII CO2 TEA laser with a pulse life of greater than 10 to the 6th power pulses in 1980. A sealed laser lifetime of greater than 10 to the 6th power pulses is acceptable for single shot cases, such as direct detection rangefinders for tank laser sights. However, in many other applications, such as tracking of fast moving targets, it is essential that a repetition rate of typically 30Hz to 100Hz is employed. In such cases, a pulse lifetime of 10 to the 6th power pulses is no longer sufficient and a minimum pulse lifetime 10 to the 7th power pulses is essential to ensure a useful service life. In 1983 Stark el al described a sealed, 100Hz CO2 TEA laser, with a life of greater than 2.6 x 10 to the 6th power, which employed heterogeneous catalysis. Following this pioneering work, GEC Avionics has been engaged in the development of sealed high repetition rate lasers with a pulse lifetime of 20 million pulses.

Bioelectrochemical conversion of CO2 to chemicals: CO2 as a next generation feedstock for electricity-driven bioproduction in batch and continuous modes.

PubMed

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

2017-09-21

The recent concept of microbial electrosynthesis (MES) has evolved as an electricity-driven production technology for chemicals from low-value carbon dioxide (CO 2 ) using micro-organisms as biocatalysts. MES from CO 2 comprises bioelectrochemical reduction of CO 2 to multi-carbon organic compounds using the reducing equivalents produced at the electrically-polarized cathode. The use of CO 2 as a feedstock for chemicals is gaining much attention, since CO 2 is abundantly available and its use is independent of the food supply chain. MES based on CO 2 reduction produces acetate as a primary product. In order to elucidate the performance of the bioelectrochemical CO 2 reduction process using different operation modes (batch vs. continuous), an investigation was carried out using a MES system with a flow-through biocathode supplied with 20 : 80 (v/v) or 80 : 20 (v/v) CO 2  : N 2 gas. The highest acetate production rate of 149 mg L -1 d -1 was observed with a 3.1 V applied cell-voltage under batch mode. While running in continuous mode, high acetate production was achieved with a maximum rate of 100 mg L -1 d -1 . In the continuous mode, the acetate production was not sustained over long-term operation, likely due to insufficient microbial biocatalyst retention within the biocathode compartment (i.e. suspended micro-organisms were washed out of the system). Restarting batch mode operations resulted in a renewed production of acetate. This showed an apparent domination of suspended biocatalysts over the attached (biofilm forming) biocatalysts. Long term CO 2 reduction at the biocathode resulted in the accumulation of acetate, and more reduced compounds like ethanol and butyrate were also formed. Improvements in the production rate and different biomass retention strategies (e.g. selecting for biofilm forming micro-organisms) should be investigated to enable continuous biochemical production from CO 2 using MES. Certainly, other process optimizations will be required to establish MES as an innovative sustainable technology for manufacturing biochemicals from CO 2 as a next generation feedstock.

Effect of CoCl(2) treatment on major and trace elements metabolism and protein concentration in mice.

PubMed

Zaksas, Nataliya; Gluhcheva, Yordanka; Sedykh, Sergey; Madzharova, Maria; Atanassova, Nina; Nevinsky, Georgy

2013-01-01

Cobalt (Co) is a transition metal and an essential trace element, required for vitamin B(12) biosynthesis, enzyme activation and other biological processes, but toxic in high concentrations. There is lack of data for the effect of long-term Co(II) treatment on the concentrations of other trace elements. We estimate the influence of cobalt chloride (CoCl(2)) on the relative content of different metals in mouse plasma using two-jet arc plasmatron atomic emission and on the total protein content. On average, the content of different elements in the plasma of 2-month-old balb/c mice (control group) decreased in the order: Ca>Mg>Si>Fe>Zn>Cu≥Al≥B. The treatment of mice for 60 days with CoCl(2) (daily dose 125 mg/kg) did not appreciably change the relative content of Ca, Cu, and Zn, while a 2.4-fold statistically significant decrease in the content of B and significant increase in the content of Mg (1.4-fold), Al and Fe (2.0-fold) and Si (3.2-fold) was found. A detectable amount of Mo was observed only for two control mice, while the plasma of 9 out of 16 mice of the treated group contained this metal. The administration of Co made its concentration detectable in the plasma of all mice of the treated group, but the relative content varied significantly. The treatment led to a 2.2-fold decrease in the concentration of the total plasma protein. Chronic exposure to CoCl(2) affects homeostasis as well as the concentrations and metabolism of other essential elements, probably due to competition of Co ions for similar binding sites within cells, altered signal transduction and protein biosynthesis. Long-term treatment also leads to significant weight changes and reduces the total protein concentration. The data may be useful for an understanding of Co toxicity, its effect on the concentration of other metal ions and different physiological processes. Copyright © 2012 Elsevier GmbH. All rights reserved.

Impact of reduced atmospheric CO2 and varied potassium supply on carbohydrate and potassium distribution in grapevine and grape berries (Vitis vinifera L.).

PubMed

Coetzee, Zelmari A; Walker, Rob R; Deloire, Alain J; Barril, Célia; Clarke, Simon J; Rogiers, Suzy Y

2017-11-01

To assess the robustness of the apparent sugar-potassium relationship during ripening of grape berries, a controlled-environment study was conducted on Shiraz vines involving ambient and reduced (by 34%) atmospheric CO 2 concentrations, and standard and increased (by 67%) soil potassium applications from prior to the onset of ripening. The leaf net photoassimilation rate was decreased by 35% in the reduced CO 2 treatment. The reduction in CO 2 delayed the onset of ripening, but at harvest the sugar content of the berry pericarp was similar to that of plants grown in ambient conditions. The potassium content of the berry pericarp in the reduced CO 2 treatment was however higher than for the ambient CO 2 . Berry potassium, sugar and water content were strongly correlated, regardless of treatments, alluding to a ternary link during ripening. Root starch content was lower under reduced CO 2 conditions, and therefore likely acted as a source of carbohydrates during berry ripening. Root carbohydrate reserve replenishment could also have been moderated under reduced CO 2 at the expense of berry ripening. Given that root potassium concentration was less in the vines grown in the low CO 2 atmosphere, these results point toward whole-plant fine-tuning of carbohydrate and potassium partitioning aimed at optimising fruit ripening. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth.

PubMed

Dellero, Younès; Lamothe-Sibold, Marlène; Jossier, Mathieu; Hodges, Michael

2015-09-01

Metabolic and physiological analyses of glutamate:glyoxylate aminotransferase 1 (GGT1) mutants were performed at the global leaf scale to elucidate the mechanisms involved in their photorespiratory growth phenotype. Air-grown ggt1 mutants showed retarded growth and development, that was not observed at high CO2 (3000 μL L(-1) ). When compared to wild-type (WT) plants, air-grown ggt1 plants exhibited glyoxylate accumulation, global changes in amino acid amounts including a decrease in serine content, lower organic acid levels, and modified ATP/ADP and NADP(+) /NADPH ratios. When compared to WT plants, their net CO2 assimilation rates (An ) were 50% lower and this mirrored decreases in ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) contents. High CO2 -grown ggt1 plants transferred to air revealed a rapid decrease of An and photosynthetic electron transfer rate while maintaining a high energetic state. Short-term (a night period and 4 h of light) transferred ggt1 leaves accumulated glyoxylate and exhibited low serine contents, while other amino acid levels were not modified. RuBisCO content, activity and activation state were not altered after a short-term transfer while the ATP/ADP ratio was lowered in ggt1 rosettes. However, plant growth and RuBisCO levels were both reduced in ggt1 leaves after a long-term (12 days) acclimation to air from high CO2 when compared to WT plants. The data are discussed with respect to a reduced photorespiratory carbon recycling in the mutants. It is proposed that the low An limits nitrogen-assimilation, this decreases leaf RuBisCO content until plants attain a new homeostatic state that maintains a constant C/N balance and leads to smaller, slower growing plants. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Lipid production of microalga Chlorella sorokiniana CY1 is improved by light source arrangement, bioreactor operation mode and deep-sea water supplements.

PubMed

Chen, Chun-Yen; Chang, Hsin-Yueh

2016-03-01

Microalgae-based biodiesel has been recognized as a sustainable and promising alternative to fossil diesel. High lipid productivity of microalgae is required for economic production of biodiesel from microalgae. This study was undertaken to enhance the growth and oil accumulation of an indigenous microalga Chlorella sorokiniana CY1 by applying engineering strategies using deep-sea water as the medium. First, the microalga was cultivated using LED as the immersed light source, and the results showed that the immersed LED could effectively enhance the oil/lipid content and final microalgal biomass concentration to 53.8% and 2.5 g/l, respectively. Next, the semi-batch photobioreactor operation with deep-sea water was shown to improve lipid content and microalgal growth over those from using batch and continuous cultures under similar operating conditions. The optimal replacement ratio was 50%, resulting in an oil/lipid content and final biomass concentration of 61.5% and 2.8 g/l, respectively. A long-term semi-batch culture utilizing 50%-replaced medium was carried out for four runs. The final biomass concentration and lipid productivity were 2.5 g/L and 112.2 mg/L/d, respectively. The fatty acid composition of the microalgal lipids was predominant by palmitic acid, stearic acid, oleic acid and linoleic acid, and this lipid quality is suitable for biodiesel production. This demonstrates that optimizing light source arrangement, bioreactor operation and deep-sea water supplements could effectively promote the lipid production of C. sorokiniana CY1 for the applications in microalgae-based biodiesel industry. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Co-gasification of solid waste and lignite - a case study for Western Macedonia.

PubMed

Koukouzas, N; Katsiadakis, A; Karlopoulos, E; Kakaras, E

2008-01-01

Co-gasification of solid waste and coal is a very attractive and efficient way of generating power, but also an alternative way, apart from conventional technologies such as incineration and landfill, of treating waste materials. The technology of co-gasification can result in very clean power plants using a wide range of solid fuels but there are considerable economic and environmental challenges. The aim of this study is to present the available existing co-gasification techniques and projects for coal and solid wastes and to investigate the techno-economic feasibility, concerning the installation and operation of a 30MW(e) co-gasification power plant based on integrated gasification combined cycle (IGCC) technology, using lignite and refuse derived fuel (RDF), in the region of Western Macedonia prefecture (WMP), Greece. The gasification block was based on the British Gas-Lurgi (BGL) gasifier, while the gas clean-up block was based on cold gas purification. The competitive advantages of co-gasification systems can be defined both by the fuel feedstock and production flexibility but also by their environmentally sound operation. It also offers the benefit of commercial application of the process by-products, gasification slag and elemental sulphur. Co-gasification of coal and waste can be performed through parallel or direct gasification. Direct gasification constitutes a viable choice for installations with capacities of more than 350MW(e). Parallel gasification, without extensive treatment of produced gas, is recommended for gasifiers of small to medium size installed in regions where coal-fired power plants operate. The preliminary cost estimation indicated that the establishment of an IGCC RDF/lignite plant in the region of WMP is not profitable, due to high specific capital investment and in spite of the lower fuel supply cost. The technology of co-gasification is not mature enough and therefore high capital requirements are needed in order to set up a direct co-gasification plant. The cost of electricity estimated was not competitive, compared to the prices dominating the Greek electricity market and thus further economic evaluation is required. The project would be acceptable if modular construction of the unit was first adopted near operating power plants, based on parallel co-gasification, and gradually incorporating the remaining process steps (gas purification, power generation) with the aim of eventually establishing a true direct co-gasification plant.

Evaluation of the Effect of Water Vapor On the Performance of NASA's NMRO Catalysts for Carbon Monoxide Oxidation

NASA Technical Reports Server (NTRS)

Akyurtlu, Ates; Akyurtlu, Jale F.; Ammons, Vaughnery; Battle, Taikelia; Gay, Amy; Bray, Kyle; Washington, Boe; Schryer, David (Technical Monitor); Jordan, Jeff (Technical Monitor)

2002-01-01

The Noble Metal Reducible Oxide (NMRO) catalysts for the low temperature oxidation of carbon monoxide were developed by NASA for the reoxidation of carbon monoxide which forms by the dissociation of carbon dioxide during the operation of sealed carbon dioxide lasers. The NMRO catalyst, which consists of a noble metal in conjunction with a reducible metal oxide, was evaluated under conditions that will be encountered in a CO2 laser operation, namely temperatures in the range 298 to 373 K and no significant reaction gas components other than CO, CO2 and O2. The NMRO catalysts may have significant potential for spin-off applications such as the prevention of carbon monoxide build-up in closed spaces as in space vehicle cabins or submarines, and the elimination of the cold start-up problem of automobile exhaust catalysts. The most significant difference in the conditions of these possible future applications is the high moisture content of the gases to be processed. Lack of understanding of the effects of water vapor and high temperature on catalyst activity and operation for extended periods are currently the main stumbling blocks for the transfer of this NASA technology to be used for commercial purposes. In the original proposal the following objectives were stated: To obtain experimental data on the adsorption, desorption and reaction characteristics of CO and CO2 the catalysts under high moisture conditions; to collect evidence on the presence of carbonate and hydroxyl surface species and their involvement in the CO oxidation mechanism; and to model the reaction system using a Monte-Carlo simulation to gain insight on the various steps involved. After the work has commenced the NASA technical monitor Mr. David Scheyer informed us that there was increased interest in the possible use of the NMRO catalysts as automobile exhaust catalysts and therefore NASA wanted to know whether the catalysts can operate at high temperatures as well as with high moisture gases. At that meeting it was decided that investigation of the high temperature performance of the NMRO catalysts should be given priority and replace the Monte-Carlo simulation objective. As a result, the modified objectives of the investigation were taken as the investigation of the high-temperature activity of the NMRO catalysts, and the effect of water vapor on the performance of these catalysts.

Anaerobic co-digestion of sewage sludge and food waste.

PubMed

Prabhu, Meghanath S; Mutnuri, Srikanth

2016-04-01

Anaerobic co-digestion of organic matter improves digester operating characteristics and its performance. In the present work, food waste was collected from the institute cafeteria. Two types of sludge (before centrifuge and after centrifuge) were collected from the fluidised bed reactor of the institute treating sewage wastewater. Food waste and sludge were studied for their physico-chemical characteristics, such as pH, chemical oxygen demand, total solids, volatile solids, ammoniacal nitrogen, and total nitrogen. A biomethane potential assay was carried out to find out the optimum mixing ratio of food waste and sludge for anaerobic co-digestion. Results indicated that food waste mixed with sludge in the ratio of 1:2 produced the maximum biogas of 823 ml gVS(-1)(21 days) with an average methane content of 60%. Batch studies were conducted in 5 L lab-glass reactors at a mesophilic temperature. The effect of different substrate loading rates on biogas production was investigated. The mixing ratio of food waste and sludge was 1:2. A loading rate of 1 gVS L d(-1)gave the maximum biogas production of 742 ml g(-1)VS L d(-1)with a methane content of 50%, followed by 2 gVS L d(-1)with biogas of 539 ml g(-1)VS L d(-1) Microbial diversity of the reactor during fed batch studies was investigated by terminal restriction fragment length polymorphism. A pilot-scale co-digestion of food waste and sludge (before centrifuge) indicated the process stability of anaerobic digestion. © The Author(s) 2016.

Magnetization mechanisms in ordered arrays of polycrystalline Fe{sub 100−x}Co{sub x} nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Viqueira, M. S.; Bajales, N.; Urreta, S. E.

2015-05-28

Magnetization reversal processes and coercivity mechanisms in polycrystalline Fe{sub 100−x}Co{sub x} nanowire arrays, resulting from an AC electrodeposition process, are investigated. The array coercivity is described on the basis of polarization reversal mechanisms operating in individual wires, under the effect of inter-wire dipolar interactions described by a mean field approximation. For individual wires, a reversal mechanism involving the nucleation and further expansion of domain-wall like spin configuration is considered. The wires have a mean grain size larger than both the nanowire diameter and the exchange length, so localized and non-cooperative nucleation modes are considered. As the Co content increases, themore » alloy saturation polarization gradually decreases, but the coercive field and the relative remanence of the arrays increase, indicating that they are not controlled by the shape anisotropy in all the composition range. The coercive field dependence on the angle between the applied field and the wire long axis is not well described by reversal mechanisms involving nucleation and further displacement of neither vortex nor transverse ideal domain walls. On the contrary, the angular dependence of the coercive field observed at room temperature is well predicted by a model considering nucleation of inverse domains by localized curling, in regions smaller than the grain size, exhibiting quite small aspect ratios as compared to those of the entire nanowire. In arrays with higher Co contents, a transition from an initial (small angle) localized curling nucleation mechanism to another one, involving localized coherent rotation is observed at about π/4.« less

The effects of pretreatment conditions on a Pt/SnO2 catalyst for the oxidation of CO in CO2 lasers

NASA Technical Reports Server (NTRS)

Schryer, David R.; Vannorman, John D.; Brown, Kenneth G.; Schryer, Jacqueline

1989-01-01

CO oxidation catalysts with high activity at 25 to 100 C are important for long life, closed cycle operation of pulsed CO2 lasers. A reductive pretreatment with either CO or H2 was shown to significantly enhance the activity of a commercially available platinum on tin (IV) oxide (Pt/SnO2) catalyst relative to an oxidative or inert pretreatment of no pretreatment. Pretreatment at temperatures of 175 C and above causes an initial dip in the observed CO2 yield before the steady state yield is attained. This dip was found to be caused by dehydration of the catalyst during pretreatment and is readily eliminated by humidifying the catalyst or the reaction gas mixture. It is hypothesized that the effect of humidification is to increase the concentration of OH groups on the catalyst surface which play a role in the reaction mechanism.

Marine biological controls on atmospheric CO2 and climate

NASA Technical Reports Server (NTRS)

Mcelroy, M. B.

1983-01-01

It is argued that the ocean is losing N gas faster than N is being returned to the ocean, and that replenishment of the N supply in the ocean usually occurs during ice ages. Available N from river and estruarine transport and from rainfall after formation by lightning are shown to be at a rate too low to compensate for the 10,000 yr oceanic lifetime of N. Ice sheets advance and transfer moraine N to the ocean, lower the sea levels, erode the ocean beds, promote greater biological productivity, and reduce CO2. Ice core samples have indicated a variability in the atmospheric N content that could be attributed to the ice age scenario.

ATP citrate lyase activity is post-translationally regulated by sink strength and impacts the wax, cutin and rubber biosynthetic pathways.

PubMed

Xing, Shufan; van Deenen, Nicole; Magliano, Pasqualina; Frahm, Lea; Forestier, Edith; Nawrath, Christiane; Schaller, Hubert; Gronover, Christian S; Prüfer, Dirk; Poirier, Yves

2014-07-01

Cytosolic acetyl-CoA is involved in the synthesis of a variety of compounds, including waxes, sterols and rubber, and is generated by the ATP citrate lyase (ACL). Plants over-expressing ACL were generated in an effort to understand the contribution of ACL activity to the carbon flux of acetyl-CoA to metabolic pathways occurring in the cytosol. Transgenic Arabidopsis plants synthesizing the polyester polyhydroxybutyrate (PHB) from cytosolic acetyl-CoA have reduced growth and wax content, consistent with a reduction in the availability of cytosolic acetyl-CoA to endogenous pathways. Increasing the ACL activity via the over-expression of the ACLA and ACLB subunits reversed the phenotypes associated with PHB synthesis while maintaining polymer synthesis. PHB production by itself was associated with an increase in ACL activity that occurred in the absence of changes in steady-state mRNA or protein level, indicating a post-translational regulation of ACL activity in response to sink strength. Over-expression of ACL in Arabidopsis was associated with a 30% increase in wax on stems, while over-expression of a chimeric homomeric ACL in the laticifer of roots of dandelion led to a four- and two-fold increase in rubber and triterpene content, respectively. Synthesis of PHB and over-expression of ACL also changed the amount of the cutin monomer octadecadien-1,18-dioic acid, revealing an unsuspected link between cytosolic acetyl-CoA and cutin biosynthesis. Together, these results reveal the complexity of ACL regulation and its central role in influencing the carbon flux to metabolic pathways using cytosolic acetyl-CoA, including wax and polyisoprenoids. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Biogeochemical controls on microbial CH4 and CO2 production in Arctic polygon tundra

NASA Astrophysics Data System (ADS)

Zheng, J.

2016-12-01

Accurately simulating methane (CH4) and carbon dioxide (CO2) emissions from high latitude soils is critically important for reducing uncertainties in soil carbon-climate feedback predictions. The signature polygonal ground of Arctic tundra generates high level of heterogeneity in soil thermal regime, hydrology and oxygen availability, which limits the application of current land surface models with simple moisture response functions. We synthesized CH4 and CO2 production measurements from soil microcosm experiments across a wet-to dry permafrost degradation gradient from low-centered (LCP) to flat-centered (FCP), and high-centered polygons (HCP) to evaluate the relative importance of biogeochemical processes and their response to warming. More degraded polygon (HCP) showed much less carbon loss as CO2 or CH4, while the total CO2 production from FCP is comparable to that from LCP. Maximum CH4 production from the active layer of LCP was nearly 10 times that of permafrost and FCP. Multivariate analyses identifies gravimetric water content and organic carbon content as key predictors for CH4 production, and iron reduction as a key regulator of pH. The synthesized data are used to validate the geochemical model PHREEQC with extended anaerobic organic substrate turnover, fermentation, iron reduction, and methanogenesis reactions. Sensitivity analyses demonstrate that better representations of anaerobic processes and their pH dependency could significantly improve estimates of CH4 and CO2 production. The synthesized data suggest local decreases in CH4 production along the polygon degradation gradient, which is consistent with previous surface flux measurements. Methane oxidation occurring through the soil column of degraded polygons contributes to their low CH4 emissions as well.

Effects of CO2 Enrichment on Growth and Development of Impatiens hawkeri

PubMed Central

Zhang, Fan-Fan; Wang, Yan-Li; Huang, Zhi-Zhe; Zhu, Xiao-Chen; Zhang, Feng-Jiao; Chen, Fa-Di; Fang, Wei-Min; Teng, Nian-Jun

2012-01-01

The effects of CO2 enrichment on growth and development of Impatiens hawkeri, an important greenhouse flower, were investigated for the purpose of providing scientific basis for CO2 enrichment to this species in greenhouse. The plants were grown in CO2-controlled growth chambers with 380 (the control) and 760 (CO2 enrichment) μmol·mol−1, respectively. The changes in morphology, physiology, biochemistry, and leaf ultrastructure of Impatiens were examined. Results showed that CO2 enrichment increased flower number and relative leaf area compared with the control. In addition, CO2 enrichment significantly enhanced photosynthetic rate, contents of soluble sugars and starch, activities of peroxidase (POD), superoxide dismutase (SOD), and ascorbate peroxidase (APX), but reduced chlorophyll content and malondialdehyde (MDA) content. Furthermore, significant changes in chloroplast ultrastructure were observed at CO2 enrichment: an increased number of starch grains with an expanded size, and an increased ratio of stroma thylakoid to grana thylakoid. These results suggest that CO2 enrichment had positive effects on Impatiens, that is, it can improve the visual value, promote growth and development, and enhance antioxidant capacity. PMID:22536147

Efficient electrochemical refrigeration power plant using natural gas with ∼100% CO2 capture

NASA Astrophysics Data System (ADS)

Al-musleh, Easa I.; Mallapragada, Dharik S.; Agrawal, Rakesh

2015-01-01

We propose an efficient Natural Gas (NG) based Solid Oxide Fuel Cell (SOFC) power plant equipped with ∼100% CO2 capture. The power plant uses a unique refrigeration based process to capture and liquefy CO2 from the SOFC exhaust. The capture of CO2 is carried out via condensation and purification using two rectifying columns operating at different pressures. The uncondensed gas mixture, comprising of relatively high purity unconverted fuel, is recycled to the SOFC and found to boost the power generation of the SOFC by 22%, when compared to a stand alone SOFC. If Liquefied Natural Gas (LNG) is available at the plant gate, then the refrigeration available from its evaporation is used for CO2 Capture and Liquefaction (CO2CL). If NG is utilized, then a Mixed Refrigerant (MR) vapor compression cycle is utilized for CO2CL. Alternatively, the necessary refrigeration can be supplied by evaporating the captured liquid CO2 at a lower pressure, which is then compressed to supercritical pressures for pipeline transportation. From rigorous simulations, the power generation efficiency of the proposed processes is found to be 70-76% based on lower heating value (LHV). The benefit of the proposed processes is evident when the efficiency of 73% for a conventional SOFC-Gas turbine power plant without CO2 capture is compared with an equivalent efficiency of 71.2% for the proposed process with CO2CL.

22 CFR 211.4 - Availability and shipment of commodities.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Regulation 11. (b) Transfer of title and delivery. (1) Unless the approved Operational Plan or TA provides... destination point of entry, upon completion of delivery by the inland carrier (landlocked countries). Except... thereof have been clearly marked as not to be certified for billing. (Name of steamship co.) By...

Factors Affecting Co-Operative vs. Competitive Behavior in Dyads.

ERIC Educational Resources Information Center

O'Day, Gerald; Phelan, Joseph G.

Theoretical interpretations of cooperation and competition are discussed in relation to motivational and situational determinants. It is suggested that the degree of competition exhibited in an interaction is an inverse function of the quantity of resources available, and that the effect of situational characteristics on cooperative behavior is…

School Education and the Lack of Parent Information

ERIC Educational Resources Information Center

Bhattacharji, Prashant; Kingdon, Geeta Gandhi

2016-01-01

Many Organisation for Economic Co-operation and Development (OECD) countries publish school rankings annually, based on the aggregated student performance of different schools in the (high-stakes) board examinations. The literature cites two reasons in favour of the public availability of information on school performance: first, the highly valued…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferguson, D.W.; Tompkins, T.A.; Pratapas, J.M.

The Coal Quality Impact Model (CQIM{trademark}) was used to evaluate the economic and performance impacts of gas co-firing at Mississippi Power Company`s Plant Watson. One of the most important benefits of gas co-firing considered was the ability to burn lower quality, less expensive fuels. Four coals and petroleum coke were evaluated at 0, 5, 10, 20, and 30 percent gas co-firing. These fuels vary widely in their geographic source, heating value, moisture, volatile matter, and sulfur contents. Performance and economic evaluations were conducted at individual load points of 100, 75, 50, 40, 30, and 20 percent of full load. Additionalmore » analyses were made for seasonal load-demand curves and for an average annual load-demand curve. Operating cost in $/MWh, net plant heat rate in Btu/kWh, and break-even gas price in $/MBtu are presented as a function of load and percent gas co-firing. Results illustrate that with the Illinois Basin Coal currently burned at Plant Watson, gas co-firing can be economically justified over a range of gas market prices on either an annual or seasonal basis. Other findings indicate that petroleum coke and South American coal co-fired with natural gas offer significant fuel cost savings and are attractive candidate fuels for combustion verification testing.« less

Effects of Fuel Cell Anode Recycle on Catalytic Fuel Reforming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shekhawat, Dushyant; Berry, D.A.; Gardner, T.H.

2007-06-01

The presence of steam in the reactant gas of a catalytic fuel reformer decreases the formation of carbon, minimizing catalyst deactivation. However, the operation of the reformer without supplemental water reduces the size, weight, cost, and overall complexity of the system. The work presented here examines experimentally two options for adding steam to the reformer inlet: (I) recycle of a simulated fuel cell anode exit gas (comprised of mainly CO2, H2O, and N2 and some H2 and CO) and (II) recycle of the reformate from the reformer exit back to the reformer inlet (mainly comprised of H2, CO, and N2more » and some H2O and CO2). As expected, anode gas recycle reduced the carbon formation and increased the hydrogen concentration in the reformate. However, reformer recycle was not as effective due principally to the lower water content in the reformate compared to the anode gas. In fact, reformate recycle showed slightly increased carbon formation compared to no recycle. In an attempt to understand the effects of individual gases in these recycle streams (H2, CO, CO2, N2, and H2O), individual gas species were independently introduced to the reformer feed.« less

Effects of fuel cell anode recycle on catalytic fuel reforming

DOE Office of Scientific and Technical Information (OSTI.GOV)

shekhawat, D.; Berry, D.; Gardner, T.

2007-01-01

The presence of steam in the reactant gas of a catalytic fuel reformer decreases the formation of carbon, minimizing catalyst deactivation. However, the operation of the reformer without supplemental water reduces the size, weight, cost, and overall complexity of the system. The work presented here examines experimentally two options for adding steam to the reformer inlet: (I) recycle of a simulated fuel cell anode exit gas (comprised of mainly CO2, H2O, and N2 and some H2 and CO) and (II) recycle of the reformate from the reformer exit back to the reformer inlet (mainly comprised of H2, CO, and N2more » and some H2O and CO2). As expected, anode gas recycle reduced the carbon formation and increased the hydrogen concentration in the reformate. However, reformer recycle was not as effective due principally to the lower water content in the reformate compared to the anode gas. In fact, reformate recycle showed slightly increased carbon formation compared to no recycle. In an attempt to understand the effects of individual gases in these recycle streams (H2, CO, CO2, N2, and H2O), individual gas species were independently introduced to the reformer feed. Published by Elsevier B.V.« less

Supercritical CO2 Extraction of Lavandula angustifolia Mill. Flowers: Optimisation of Oxygenated Monoterpenes, Coumarin and Herniarin Content.

PubMed

Jerković, Igor; Molnar, Maja; Vidović, Senka; Vladić, Jelena; Jokić, Stela

2017-11-01

Lavandula angustifolia is good source of oxygenated monoterpenes containing coumarins as well, which are all soluble in supercritical CO 2 (SC-CO 2 ). The study objective is to investigate SC-CO 2 extraction parameters on: the total yield; GC-MS profile of the extracts; relative content of oxygenated monoterpenes; the amount of coumarin and herniarin; and to determine optimal SC-CO 2 extraction conditions by response surface methodology (RSM). SC-CO 2 extraction was performed under different pressure, temperature and CO 2 flow rate determined by Box-Behnken design (BBD). The sample mass and the extraction time were kept constant. The chemical profiles and relative content of oxygenated monoterpenes (as coumarin equivalents, CE) were determined by GC-MS. Coumarin and herniarin concentrations were dosed by HPLC. SC-CO 2 extracts contained linalool (57.4-217.9 mg CE/100 g), camphor (10.6-154.4 mg CE/100 g), borneol (6.2-99.9 mg CE/100 g), 1,8-cineole (5.0-70.4 mg CE/100 g), linalyl acetate (86.1-267.9 mg CE/100 g), coumarin (0.95-18.16 mg/100 g), and herniarin (0.95-13.63 mg/100 g). The interaction between the pressure and CO 2 flow rate as well as between the temperature and CO 2 flow rate showed statistically significant influence on the extraction yield. Applying BBD, the optimum extraction conditions for higher monoterpenes and lower coumarin content were at 10 MPa, 41°C and CO 2 flow rate 2.3 kg/h, and at 30 MPa, 50°C and CO 2 flow rate 3 kg/h for higher monoterpenes and coumarin content. SC-CO 2 extraction is a viable technique for obtaining lavender extracts with desirable flavour components. The second-order model based on BBD predicts the results for SC-CO 2 extraction quite satisfactorily. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Elevated CO2 and/or ozone modify lignification in the wood of poplars (Populus tremula x alba)

PubMed Central

Richet, Nicolas; Afif, Dany; Tozo, Koffi; Pollet, Brigitte; Maillard, Pascale; Huber, Françoise; Priault, Pierrick; Banvoy, Jacques; Gross, Patrick; Dizengremel, Pierre; Lapierre, Catherine; Perré, Patrick; Cabané, Mireille

2012-01-01

Trees will have to cope with increasing levels of CO2 and ozone in the atmosphere. The purpose of this work was to assess whether the lignification process could be altered in the wood of poplars under elevated CO2 and/or ozone. Young poplars were exposed either to charcoal-filtered air (control), to elevated CO2 (800 μl l−1), to ozone (200 nl l−1) or to a combination of elevated CO2 and ozone in controlled chambers. Lignification was analysed at different levels: biosynthesis pathway activities (enzyme and transcript), lignin content, and capacity to incorporate new assimilates by using 13C labelling. Elevated CO2 and ozone had opposite effects on many parameters (growth, biomass, cambial activity, wood cell wall thickness) except on lignin content which was increased by elevated CO2 and/or ozone. However, this increased lignification was due to different response mechanisms. Under elevated CO2, carbon supply to the stem and effective lignin synthesis were enhanced, leading to increased lignin content, although there was a reduction in the level of some enzyme and transcript involved in the lignin pathway. Ozone treatment induced a reduction in carbon supply and effective lignin synthesis as well as transcripts from all steps of the lignin pathway and some corresponding enzyme activities. However, lignin content was increased under ozone probably due to variations in other major components of the cell wall. Both mechanisms seemed to coexist under combined treatment and resulted in a high increase in lignin content. PMID:22553285

An in-depth study of HD 174966 with CoRoT photometry and HARPS spectroscopy. Large separation as a new observable for δ Scuti stars

NASA Astrophysics Data System (ADS)

García Hernández, A.; Moya, A.; Michel, E.; Suárez, J. C.; Poretti, E.; Martín-Ruíz, S.; Amado, P. J.; Garrido, R.; Rodríguez, E.; Rainer, M.; Uytterhoeven, K.; Rodrigo, C.; Solano, E.; Rodón, J. R.; Mathias, P.; Rolland, A.; Auvergne, M.; Baglin, A.; Baudin, F.; Catala, C.; Samadi, R.

2013-11-01

Aims: The aim of this work was to use a multi-approach technique to derive the most accurate values possible of the physical parameters of the δ Sct star HD 174966, which was observed with the CoRoT satellite. In addition, we searched for a periodic pattern in the frequency spectra with the goal of using it to determine the mean density of the star. Methods: First, we extracted the frequency content from the CoRoT light curve. Then, we derived the physical parameters of HD 174966 and carried a mode identification out from the spectroscopic and photometric observations. We used this information to look for the models fulfilling all the conditions and discussed the inaccuracies of the method because of the rotation effects. In a final step, we searched for patterns in the frequency set using a Fourier transform, discussed its origin, and studied the possibility of using the periodicity to obtain information about the physical parameters of the star. Results: A total of 185 peaks were obtained from the Fourier analysis of the CoRoT light curve, all of which were reliable pulsating frequencies. From the spectroscopic observations, 18 oscillation modes were detected and identified, and the inclination angle (62.5°-17.5+7.5) and the rotational velocity of the star (142 km s-1) were estimated. From the multi-colour photometric observations, only three frequencies were detected that correspond to the main ones in the CoRoT light curve. We looked for periodicities within the 185 frequencies and found a quasiperiodic pattern Δν ~ 64 μHz. Using the inclination angle, the rotational velocity, and an Echelle diagram (showing a double comb outside the asymptotic regime), we concluded that the periodicity corresponds to a large separation structure. The quasiperiodic pattern allowed us to discriminate models from a grid. As a result, the value of the mean density is achieved with a 6% uncertainty. So, the Δν pattern could be used as a new observable for A-F type stars. The CoRoT space mission was developed and is operated by the French space agency CNES, with participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain.This work is based on ground-based observations made with the ESO 3.6 m telescope at La Silla Observatory under the ESO Large Programme LP182.D-0356, and on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated jointly by the Max-Planck-Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC), and on observations made at Observatoire de Haute Provence (CNRS), France, and at Observatorio de Sierra Nevada (OSN), Spain, operated by the Instituto de Astrofísica de Andalucía (CSIC). This research has made use of both the Simbad database, operated at CDS, Strasbourg, France, and the Astrophysics Data System, provided by NASA, USA.Table 6 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/559/A63

Dynamic biogas upgrading based on the Sabatier process: thermodynamic and dynamic process simulation.

PubMed

Jürgensen, Lars; Ehimen, Ehiaze Augustine; Born, Jens; Holm-Nielsen, Jens Bo

2015-02-01

This study aimed to investigate the feasibility of substitute natural gas (SNG) generation using biogas from anaerobic digestion and hydrogen from renewable energy systems. Using thermodynamic equilibrium analysis, kinetic reactor modeling and transient simulation, an integrated approach for the operation of a biogas-based Sabatier process was put forward, which was then verified using a lab scale heterogenous methanation reactor. The process simulation using a kinetic reactor model demonstrated the feasibility of the production of SNG at gas grid standards using a single reactor setup. The Wobbe index, CO2 content and calorific value were found to be controllable by the H2/CO2 ratio fed the methanation reactor. An optimal H2/CO2 ratio of 3.45-3.7 was seen to result in a product gas with high calorific value and Wobbe index. The dynamic reactor simulation verified that the process start-up was feasible within several minutes to facilitate surplus electricity use from renewable energy systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

CO2 content of andesitic melts at graphite-saturated upper mantle conditions with implications for redox state of oceanic basalt source regions and remobilization of reduced carbon from subducted eclogite

NASA Astrophysics Data System (ADS)

Eguchi, James; Dasgupta, Rajdeep

2017-03-01

We have performed experiments to determine the effects of pressure, temperature and oxygen fugacity on the CO2 contents in nominally anhydrous andesitic melts at graphite saturation. The andesite composition was specifically chosen to match a low-degree partial melt composition that is generated from MORB-like eclogite in the convective, oceanic upper mantle. Experiments were performed at 1-3 GPa, 1375-1550 °C, and fO2 of FMQ -3.2 to FMQ -2.3 and the resulting experimental glasses were analyzed for CO2 and H2O contents using FTIR and SIMS. Experimental results were used to develop a thermodynamic model to predict CO2 content of nominally anhydrous andesitic melts at graphite saturation. Fitting of experimental data returned thermodynamic parameters for dissolution of CO2 as molecular CO2: ln( K 0) = -21.79 ± 0.04, Δ V 0 = 32.91 ± 0.65 cm3mol-1, Δ H 0 = 107 ± 21 kJ mol-1, and dissolution of CO2 as CO3 2-: ln (K 0 ) = -21.38 ± 0.08, Δ V 0 = 30.66 ± 1.33 cm3 mol-1, Δ H 0 = 42 ± 37 kJ mol-1, where K 0 is the equilibrium constant at some reference pressure and temperature, Δ V 0 is the volume change of reaction, and Δ H 0 is the enthalpy change of reaction. The thermodynamic model was used along with trace element partition coefficients to calculate the CO2 contents and CO2/Nb ratios resulting from the mixing of a depleted MORB and the partial melt of a graphite-saturated eclogite. Comparison with natural MORB and OIB data suggests that the CO2 contents and CO2/Nb ratios of CO2-enriched oceanic basalts cannot be produced by mixing with partial melts of graphite-saturated eclogite. Instead, they must be produced by melting of a source containing carbonate. This result places a lower bound on the oxygen fugacity for the source region of these CO2-enriched basalts, and suggests that fO2 measurements made on cratonic xenoliths may not be applicable to the convecting upper mantle. CO2-depleted basalts, on the other hand, are consistent with mixing between depleted MORB and partial melts of a graphite-saturated eclogite. Furthermore, calculations suggest that eclogite can remain saturated in graphite in the convecting upper mantle, acting as a reservoir for C.

Video content analysis of surgical procedures.

PubMed

Loukas, Constantinos

2018-02-01

In addition to its therapeutic benefits, minimally invasive surgery offers the potential for video recording of the operation. The videos may be archived and used later for reasons such as cognitive training, skills assessment, and workflow analysis. Methods from the major field of video content analysis and representation are increasingly applied in the surgical domain. In this paper, we review recent developments and analyze future directions in the field of content-based video analysis of surgical operations. The review was obtained from PubMed and Google Scholar search on combinations of the following keywords: 'surgery', 'video', 'phase', 'task', 'skills', 'event', 'shot', 'analysis', 'retrieval', 'detection', 'classification', and 'recognition'. The collected articles were categorized and reviewed based on the technical goal sought, type of surgery performed, and structure of the operation. A total of 81 articles were included. The publication activity is constantly increasing; more than 50% of these articles were published in the last 3 years. Significant research has been performed for video task detection and retrieval in eye surgery. In endoscopic surgery, the research activity is more diverse: gesture/task classification, skills assessment, tool type recognition, shot/event detection and retrieval. Recent works employ deep neural networks for phase and tool recognition as well as shot detection. Content-based video analysis of surgical operations is a rapidly expanding field. Several future prospects for research exist including, inter alia, shot boundary detection, keyframe extraction, video summarization, pattern discovery, and video annotation. The development of publicly available benchmark datasets to evaluate and compare task-specific algorithms is essential.

The effect of heat waves, elevated [CO2 ] and low soil water availability on northern red oak (Quercus rubra L.) seedlings.

PubMed

Bauweraerts, Ingvar; Wertin, Timothy M; Ameye, Maarten; McGuire, Mary Anne; Teskey, Robert O; Steppe, Kathy

2013-02-01

The frequency and intensity of heat waves are predicted to increase. This study investigates whether heat waves would have the same impact as a constant increase in temperature with the same heat sum, and whether there would be any interactive effects of elevated [CO2 ] and soil moisture content. We grew Quercus rubra seedlings in treatment chambers maintained at either ambient or elevated [CO2 ] (380 or 700 μmol CO2 mol(-1) ) with temperature treatments of ambient, ambient +3 °C, moderate heat wave (+6 °C every other week) or severe heat wave (+12 °C every fourth week) temperatures. Averaged over a 4-week period, and the entire growing season, the three elevated temperature treatments had the same average temperature and heat sum. Half the seedlings were watered to a soil water content near field capacity, half to about 50% of this value. Foliar gas exchange measurements were performed morning and afternoon (9:00 and 15:00 hours) before, during and after an applied heat wave in August 2010. Biomass accumulation was measured after five heat wave cycles. Under ambient [CO2 ] and well-watered conditions, biomass accumulation was highest in the +3 °C treatment, intermediate in the +6 °C heat wave and lowest in the +12 °C heat wave treatment. This response was mitigated by elevated [CO2 ]. Low soil moisture significantly decreased net photosynthesis (Anet ) and biomass in all [CO2 ] and temperature treatments. The +12 °C heat wave reduced afternoon Anet by 23% in ambient [CO2 ]. Although this reduction was relatively greater under elevated [CO2 ], Anet values during this heat wave were still 34% higher than under ambient [CO2 ]. We concluded that heat waves affected biomass growth differently than the same amount of heat applied uniformly over the growing season, and that the plant response to heat waves also depends on [CO2 ] and soil moisture conditions. © 2012 Blackwell Publishing Ltd.

Effects of elevated CO2 concentrations on denitrifying and nitrifying popualtions at terrestrial CO2 leakeage analogous sites

NASA Astrophysics Data System (ADS)

Christine, Dictor Marie; Catherine, Joulian; Valerie, Laperche; Stephanie, Coulon; Dominique, Breeze

2010-05-01

CO2 capture and geological storage (CCS) is recognized to be an important option for carbon abatement in Europe. One of the risks of CCS is the leakage from storage site. A laboratory was conducted on soil samples sampled near-surface from a CO2 leakage analogous site (Latera, Italy) in order to evaluate the impact of an elevated soil CO2 concentration on terrestrial bacterial ecosystems form near surface terrestrial environments and to determine a potential bacterial indicator of CO2 leakage from storage site. Surveys were conducted along a 50m long transect across the vent centre, providing a spectrum of CO2 flux rates, soil gas concentrations and compositions (Beaubien et al., 2007). A bacterial diversity studies, performed by CE-SSCP technique, on a soil profile with increasing CO2 soil concentrations (from 0.3% to 100%) showed that a change on bacterial diversity was noted when CO2 concentration was above 50 % of CO2. From this result, 3 soil samples were taken at 70 cm depth in 3 distinct zones (background soil CO2 content, soil CO2 content of 20% and soil CO2 content of 50%). Then theses soil samples were incubated under closed jars flushed with different air atmospheres (20, 50 and 90 % of CO2) during 18 months. At initial, 3, 6, 12 and 18 months, some soil samples were collected in order to estimate the denitrifying, nitrifying activities as a function of CO2 concentration content and times. Theses enzymatic activities were chosen because one occurs under anaerobic conditions (denitrification) and the other occurs under aerobic conditions (nitrification). Both of them were involved in the nitrogen cycle and are major actors of soil function and groundwater quality preservation. Metabolic diversity using BIOLOG Ecoplates was determined on every soil samples. Physico-chemical parameters (e.g. pH, bulk chemistry, mineralogy) were analyzed to have some information about the evolution of the soil during the incubation with increasing soil CO2 concentrations. Statistical analyses were performed to correlate microbiological measures and physico-chemical parameters. For the soil sampled in a zone with background CO2 content, incubation under an atmosphere with 20% of CO2, induce a sharp decrease of denitrifying activity after 6 months of incubation and only after 3 months with an atmosphere of 50% of CO2. On the contrary, concerning the soil sampled in a zone with 25.5% of CO2, incubation with an atmosphere of 50% has no effect on denitrifying activity and moreover this activity was stimulated with an atmosphere of 90% of CO2.Last, with the soil sampled in an area with 65.8% of CO2, denitrifying activity was negatively impacted from the 3th month of incubation with 90% CO2.and the activity was 2 fold lower after 12th of incubation. Concerning the nitrifying activity, soil sampled in an area with background CO2 content, this one remains little affected by increasing CO2 incubation. At initial times, soil sampled in the areas with 25.5 and 65.8 % of CO2 showed low level of nitrifying activities and further CO2 incubations have no effect on these activities. At the end, denitrifying activities seems to be more sensitive to CO2 concentrations evolution in the soil. More studies need to be done as incubation with lower CO2 content (< 10%) in order to determine the threshold of CO2 that can affect the near-surface bacterial activities and identify a possible candidate of CO2 leakage from deep reservoirs.

The increase of current atmospheric CO2 and temperature can benefit leaf gas exchanges, carbohydrate content and growth in C4 grass invaders of the Cerrado biome.

PubMed

Faria, A P de; Marabesi, M A; Gaspar, M; França, M G C

2018-06-01

Leaf gas exchanges, carbohydrate metabolism and growth of three Brazilian Cerrado invasive African grasses were evaluated after growing for 75 days under doubled CO 2 concentration and temperature elevated by 3 °C. Results showed that although the species presented photosynthetic C4 metabolism, they all had some kind of positive response to increased CO 2 . Urochloa brizantha and Megathyrsus maximus showed increased height for all induced environmental conditions. Urochloa decumbens showed only improvement in water use efficiency (WUE), while U. brizantha showed increased CO 2 assimilation and M. maximus presented higher biomass accumulation under doubled CO 2 concentration. The most significant improvement of increased CO 2 in all three species appears to be the increase in WUE. This improvement probably explains the positive increase of photosynthesis and biomass accumulation presented by U. brizantha and M. maximus, respectively. The increase in temperature affected leaf carbohydrate content of M. maximus by reducing sucrose, glucose and fructose content. These reductions were not related to thermal stress since photosynthesis and growth were not harmed. Cellulose content was not affected in any of the three species, just the lignin content in U. decumbens and M. maximus. All treatments promoted lignin content reduction in U. brizantha, suggesting a delay in leaf maturation of this species. Together, the results indicate that climate change may differentially promote changes in leaf gas exchanges, carbohydrate content and growth in C4 plant species studied and all of them could benefit in some way from these changes, constituting a threat to the native Cerrado biodiversity. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Transcriptional reprogramming and stimulation of leaf respiration by elevated CO2 concentration is diminished, but not eliminated, under limiting nitrogen supply.

PubMed

Markelz, R J Cody; Lai, Lisa X; Vosseler, Lauren N; Leakey, Andrew D B

2014-04-01

Plant respiration responses to elevated CO2 concentration ( [CO2 ] ) have been studied for three decades without consensus about the mechanism of response. Positive effects of elevated [CO2 ] on leaf respiration have been attributed to greater substrate supply resulting from stimulated photosynthesis. Negative effects of elevated [CO2 ] on leaf respiration have been attributed to reduced demand for energy for protein turnover assumed to result from lower leaf N content. Arabidopsis thaliana was grown in ambient (370 ppm) and elevated (750 ppm) [CO2 ] with limiting and ample N availabilities. The stimulation of leaf dark respiration was attenuated in limiting N (+12%) compared with ample N supply (+30%). This response was associated with smaller stimulation of photosynthetic CO2 uptake, but not interactive effects of elevated CO2 and N supply on leaf protein, amino acids or specific leaf area. Elevated [CO2 ] also resulted in greater abundance of transcripts for many components of the respiratory pathway. A greater transcriptional response to elevated [CO2 ] was observed in ample N supply at midday versus midnight, consistent with reports that protein synthesis is greatest during the day. Greater foliar expression of respiratory genes under elevated [CO2 ] has now been observed in diverse herbaceous species, suggesting a widely conserved response. © 2013 John Wiley & Sons Ltd.

Peatland simulator connecting drainage, nutrient cycling, forest growth, economy and GHG efflux in boreal and tropical peatlands

NASA Astrophysics Data System (ADS)

Lauren, Ari; Hökkä, Hannu; Launiainen, Samuli; Palviainen, Marjo; Lehtonen, Aleksi

2016-04-01

Forest growth in peatlands is nutrient limited; principal source of nutrients is the decomposition of organic matter. Excess water decreases O2 diffusion and slows down the nutrient release. Drainage increases organic matter decomposition, CO2 efflux, and nutrient supply, and enhances the growth of forest. Profitability depends on costs, gained extra yield and its allocation into timber assortments, and the rate of interest. We built peatland simulator Susi to define and parameterize these interrelations. We applied Susi-simulator to compute water and nutrient processes, forest growth, and CO2 efflux of forested drained peatland. The simulator computes daily water fluxes and storages in two dimensions for a peatland forest strip located between drainage ditches. The CO2 efflux is made proportional to peat bulk density, soil temperature and O2 availability. Nutrient (N, P, K) release depends on decomposition and peat nutrient content. Growth limiting nutrient is detected by comparing the need and supply of nutrients. Increased supply of growth limiting nutrient is used to quantify the forest growth response to improved drainage. The extra yield is allocated into pulpwood and sawlogs based on volume of growing stock. The net present values of ditch cleaning operation and the gained extra yield are computed under different rates of interest to assess the profitability of the ditch cleaning. The hydrological sub-models of Susi-simulator were first parameterized using daily water flux data from Hyytiälä SMEAR II-site, after which the predictions were tested against independent hydrologic data from two drained peatland forests in Southern Finland. After verification of the hydrologic model, the CO2 efflux, nutrient release and forest growth proportionality hypothesis was tested and model performance validated against long-term forest growth and groundwater level data from 69 forested peatland sample plots in Central Finland. The results showed a clear relation between the stand growth, nutrient availability, and CO2 efflux. Potassium was the main limiting factor for the forest growth. This indicates that management aiming at decreasing heterotrophic CO2 efflux by raising the ground water table will decrease the forest growth. From the C balance perspective the growth rate of the tree stand becomes essential. Modelling approach enables a search for an optimal management schedule for producing timber in situation when there is a price given for release of C. Ditch network maintenance by ditch cleaning becomes profitable if: i) the initial drainage is very poor, ii) the availability of the critical nutrient is sufficient, iii) during prolonged rainy conditions, and iv) the tree stand is Scots pine (Pinus sylvestris) dominated and v) in a phase where most of the extra yield is allocated into sawlogs. The simulator and its holistic approach has been successfully implemented in both tropical pulpwood plantations in Sumatra, Indonesia and in Finnish boreal forests.

Synthesis of multi-walled carbon nanotubes using CoMnMgO catalysts through catalytic chemical vapor deposition

NASA Astrophysics Data System (ADS)

Yang, Wen; Feng, Yan-Yan; Jiang, Cheng-Fa; Chu, Wei

2014-12-01

The CoMgO and CoMnMgO catalysts are prepared by a co-precipitation method and used as the catalysts for the synthesis of carbon nanotubes (CNTs) through the catalytic chemical vapor deposition (CCVD). The effects of Mn addition on the carbon yield and structure are investigated. The catalysts are characterized by temperature programmed reduction (TPR) and X-ray diffraction (XRD) techniques, and the synthesized carbon materials are characterized by transmission electron microscopy (TEM) and thermo gravimetric analysis (TG). TEM measurement indicates that the catalyst CoMgO enclosed completely in the produced graphite layer results in the deactivation of the catalyst. TG results suggest that the CoMnMgO catalyst has a higher selectivity for CNTs than CoMgO. Meanwhile, different diameters of CNTs are synthesized by CoMnMgO catalysts with various amounts of Co content, and the results show that the addition of Mn avoids forming the enclosed catalyst, prevents the formation of amorphous carbon, subsequently promotes the growth of CNTs, and the catalyst with decreased Co content is favorable for the synthesis of CNTs with a narrow diameter distribution. The CoMnMgO catalyst with 40% Co content has superior catalytic activity for the growth of carbon nanotubes.

49 CFR 384.225 - CDLIS driver recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-10-01

... operating a CMV. (c) Make CDLIS driver record information required by this section available to the users....231(d). (e) Only the following users or their authorized agents may receive the designated information... procedures. (f) The content of the report provided a user authorized by paragraph (e) of this section from...

Design of new genome- and gene-sourced primers and identification of QTL for seed oil content in a specially high-oil Brassica napus cultivar.

PubMed

Sun, Meiyu; Hua, Wei; Liu, Jing; Huang, Shunmou; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

2012-01-01

Rapeseed (Brassica napus L.) is one of most important oilseed crops in the world. There are now various rapeseed cultivars in nature that differ in their seed oil content because they vary in oil-content alleles and there are high-oil alleles among the high-oil rapeseed cultivars. For these experiments, we generated doubled haploid (DH) lines derived from the cross between the specially high-oil cultivar zy036 whose seed oil content is approximately 50% and the specially low-oil cultivar 51070 whose seed oil content is approximately 36%. First, to address the deficiency in polymorphic markers, we designed 5944 pairs of newly developed genome-sourced primers and 443 pairs of newly developed primers related to oil-content genes to complement the 2244 pairs of publicly available primers. Second, we constructed a new DH genetic linkage map using 527 molecular markers, consisting of 181 publicly available markers, 298 newly developed genome-sourced markers and 48 newly developed markers related to oil-content genes. The map contained 19 linkage groups, covering a total length of 2,265.54 cM with an average distance between markers of 4.30 cM. Third, we identified quantitative trait loci (QTL) for seed oil content using field data collected at three sites over 3 years, and found a total of 12 QTL. Of the 12 QTL associated with seed oil content identified, 9 were high-oil QTL which derived from the specially high-oil cultivar zy036. Two high-oil QTL on chromosomes A2 and C9 co-localized in two out of three trials. By QTL mapping for seed oil content, we found four candidate genes for seed oil content related to four gene markers: GSNP39, GSSR161, GIFLP106 and GIFLP046. This information will be useful for cloning functional genes correlated with seed oil content in the future.

Design of New Genome- and Gene-Sourced Primers and Identification of QTL for Seed Oil Content in a Specially High-Oil Brassica napus Cultivar

PubMed Central

Liu, Jing; Huang, Shunmou; Wang, Xinfa; Liu, Guihua; Wang, Hanzhong

2012-01-01

Rapeseed (Brassica napus L.) is one of most important oilseed crops in the world. There are now various rapeseed cultivars in nature that differ in their seed oil content because they vary in oil-content alleles and there are high-oil alleles among the high-oil rapeseed cultivars. For these experiments, we generated doubled haploid (DH) lines derived from the cross between the specially high-oil cultivar zy036 whose seed oil content is approximately 50% and the specially low-oil cultivar 51070 whose seed oil content is approximately 36%. First, to address the deficiency in polymorphic markers, we designed 5944 pairs of newly developed genome-sourced primers and 443 pairs of newly developed primers related to oil-content genes to complement the 2244 pairs of publicly available primers. Second, we constructed a new DH genetic linkage map using 527 molecular markers, consisting of 181 publicly available markers, 298 newly developed genome-sourced markers and 48 newly developed markers related to oil-content genes. The map contained 19 linkage groups, covering a total length of 2,265.54 cM with an average distance between markers of 4.30 cM. Third, we identified quantitative trait loci (QTL) for seed oil content using field data collected at three sites over 3 years, and found a total of 12 QTL. Of the 12 QTL associated with seed oil content identified, 9 were high-oil QTL which derived from the specially high-oil cultivar zy036. Two high-oil QTL on chromosomes A2 and C9 co-localized in two out of three trials. By QTL mapping for seed oil content, we found four candidate genes for seed oil content related to four gene markers: GSNP39, GSSR161, GIFLP106 and GIFLP046. This information will be useful for cloning functional genes correlated with seed oil content in the future. PMID:23077542

Characterization and Ectopic Expression of CoWRI1, an AP2/EREBP Domain-Containing Transcription Factor from Coconut (Cocos nucifera L.) Endosperm, Changes the Seeds Oil Content in Transgenic Arabidopsis thaliana and Rice (Oryza sativa L.)

PubMed Central

Sun, RuHao; Ye, Rongjian; Gao, Lingchao; Zhang, Lin; Wang, Rui; Mao, Ting; Zheng, Yusheng; Li, Dongdong; Lin, Yongjun

2017-01-01

Coconut (Cocos nucifera L.) is a key tropical crop and a member of the monocotyledonous family Arecaceae (Palmaceae). Few genes and related metabolic processes involved in coconut endosperm development have been investigated. In this study, a new member of the WRI1 gene family was isolated from coconut endosperm and was named CoWRI1. Its transcriptional activities and interactions with the acetyl-CoA carboxylase (BCCP2) promoter of CoWRI1 were confirmed by the yeast two-hybrid and yeast one-hybrid approaches, respectively. Functional characterization was carried out through seed-specific expression in Arabidopsis and endosperm-specific expression in rice. In transgenic Arabidopsis, high over-expressions of CoWRI1 in seven independent T2 lines were detected by quantitative real-time PCR. The relative mRNA accumulation of genes encoding enzymes involved in either fatty acid biosynthesis or triacylglycerols assembly (BCCP2, KASI, MAT, ENR, FATA, and GPDH) were also assayed in mature seeds. Furthermore, lipid and fatty acids C16:0 and C18:0 significantly increased. In two homozygous T2 transgenic rice lines (G5 and G2), different CoWRI1 expression levels were detected, but no CoWRI1 transcripts were detected in the wild type. Analyses of the seed oil content, starch content, and total protein content indicated that the two T2 transgenic lines showed a significant increase (P < 0.05) in seed oil content. The transgenic lines also showed a significant increase in starch content, whereas total protein content decreased significantly. Further analysis of the fatty acid composition revealed that palmitic acid (C16:0) and linolenic acid (C18:3) increased significantly in the seeds of the transgenic rice lines, but oleic acid (C18:1) levels significantly declined. PMID:28179911

Characterization and Ectopic Expression of CoWRI1, an AP2/EREBP Domain-Containing Transcription Factor from Coconut (Cocos nucifera L.) Endosperm, Changes the Seeds Oil Content in Transgenic Arabidopsis thaliana and Rice (Oryza sativa L.).

PubMed

Sun, RuHao; Ye, Rongjian; Gao, Lingchao; Zhang, Lin; Wang, Rui; Mao, Ting; Zheng, Yusheng; Li, Dongdong; Lin, Yongjun

2017-01-01

Coconut ( Cocos nucifera L.) is a key tropical crop and a member of the monocotyledonous family Arecaceae ( Palmaceae ). Few genes and related metabolic processes involved in coconut endosperm development have been investigated. In this study, a new member of the WRI1 gene family was isolated from coconut endosperm and was named CoWRI1 . Its transcriptional activities and interactions with the acetyl-CoA carboxylase ( BCCP2 ) promoter of CoWRI1 were confirmed by the yeast two-hybrid and yeast one-hybrid approaches, respectively. Functional characterization was carried out through seed-specific expression in Arabidopsis and endosperm-specific expression in rice. In transgenic Arabidopsis , high over-expressions of CoWRI1 in seven independent T2 lines were detected by quantitative real-time PCR. The relative mRNA accumulation of genes encoding enzymes involved in either fatty acid biosynthesis or triacylglycerols assembly (BCCP2, KASI, MAT, ENR, FATA, and GPDH) were also assayed in mature seeds. Furthermore, lipid and fatty acids C16:0 and C18:0 significantly increased. In two homozygous T2 transgenic rice lines (G5 and G2), different CoWRI1 expression levels were detected, but no CoWRI1 transcripts were detected in the wild type. Analyses of the seed oil content, starch content, and total protein content indicated that the two T2 transgenic lines showed a significant increase ( P < 0.05) in seed oil content. The transgenic lines also showed a significant increase in starch content, whereas total protein content decreased significantly. Further analysis of the fatty acid composition revealed that palmitic acid (C16:0) and linolenic acid (C18:3) increased significantly in the seeds of the transgenic rice lines, but oleic acid (C18:1) levels significantly declined.

Four reference soil and rock samples for measuring element availability in the Western Energy Regions

USGS Publications Warehouse

Crock, J.G.; Severson, R.C.

1980-01-01

Attaining acceptable precision in extractable element determinations is more difficult than in total element determinations. In total element determinations, dissolution of the sample is qualitatively checked by the clarity of the solution and the absence of residues. These criteria cannot be used for extracts. Possibilities for error are introduced in virtually every step in soil extractions. Therefore, the use of reference materials whose homogeneity and element content are reasonably well known is essential for determination of extractable elements. In this report, estimates of homogeneity and element content are presented for four reference samples. Bulk samples of about 100 kilograms of each sample were ground to pass an 80-mesh sieve. The samples were homogenized and split using a Jones-type splitter. Fourteen splits of each reference sample were analyzed for total content of Ca, Co, Cu, Fe, K, Mg, Mn, Na, and Zn; DTPA-extractable Cd, Co, Cu, Fe, Mn, Ni, Pb, and Zn; exchangeable Ca, Mg, K, and Na; cation exchange capacity water-saturation-extractable Ca, Mg, K, Na, C1, and SO4; soil pH; and hot-water-extractable boron. Error measured between splits was small, indicating that the samples were homogenized adequately and that the laboratory procedure provided reproducible results.

Effect of Sr Content and Strain on Sr Surface Segregation of La 1–x Sr x Co 0.2 Fe 0.8 O 3-δ as Cathode Material for Solid Oxide Fuel Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Yang; Ludwig, Karl F.; Woicik, Joseph C.

2016-10-12

Strontium doped lanthanum cobalt ferrite (LSCF) is a widely used cathode material due to its high electronic and ionic conductivity, and reasonable oxygen surface exchange coefficient. However, LSCF can have long-term stability issues such as surface segregation of Sr during solid oxide fuel cell (SOFC) operation, which can adversely affect the electrochemical performance. Thus, understanding the nature of the Sr surface segregation phenomenon, and how it is affected by the composition of LSCF and strain are critical. In this research, heteroepitaxial thin films of La 1-x Sr xCo 0.2Fe 0.8O 3 - with varying Sr content (x = 0.4, 0.3,more » 0.2) were deposited by pulsed laser deposition (PLD) on single crystal NdGaO 3, SrTiO 3 and GdScO 3 substrates, leading to different levels of strain in the films. The extent of Sr segregation at the film surface was quantified using synchrotron-based total reflection x-ray fluorescence (TXRF), and atomic force microscopy (AFM). The electronic structure of the Sr-rich phases formed on the surface was investigated by hard X-ray photoelectron spectroscopy (HAXPES). The extent of Sr segregation was found to be a function of the Sr content in bulk. Lowering the Sr content from 40% to 30% reduced the surface segregation, but further lowering the Sr content to 20% increased the segregation. The strain of LSCF thin films on various substrates was measured using high-resolution x-ray diffraction (HRXRD) and the Sr surface segregation was found to be reduced with compressive strain and enhanced with tensile strain present within the thin films. A model was developed correlating the Sr surface segregation with Sr content and strain effects to explain the experimental results.« less

Value-Based Caching in Information-Centric Wireless Body Area Networks

PubMed Central

Al-Turjman, Fadi M.; Imran, Muhammad; Vasilakos, Athanasios V.

2017-01-01

We propose a resilient cache replacement approach based on a Value of sensed Information (VoI) policy. To resolve and fetch content when the origin is not available due to isolated in-network nodes (fragmentation) and harsh operational conditions, we exploit a content caching approach. Our approach depends on four functional parameters in sensory Wireless Body Area Networks (WBANs). These four parameters are: age of data based on periodic request, popularity of on-demand requests, communication interference cost, and the duration for which the sensor node is required to operate in active mode to capture the sensed readings. These parameters are considered together to assign a value to the cached data to retain the most valuable information in the cache for prolonged time periods. The higher the value, the longer the duration for which the data will be retained in the cache. This caching strategy provides significant availability for most valuable and difficult to retrieve data in the WBANs. Extensive simulations are performed to compare the proposed scheme against other significant caching schemes in the literature while varying critical aspects in WBANs (e.g., data popularity, cache size, publisher load, connectivity-degree, and severe probabilities of node failures). These simulation results indicate that the proposed VoI-based approach is a valid tool for the retrieval of cached content in disruptive and challenging scenarios, such as the one experienced in WBANs, since it allows the retrieval of content for a long period even while experiencing severe in-network node failures. PMID:28106817

Accuracy and usefulness of the AVOXimeter 4000 as routine analysis of carboxyhemoglobin.

PubMed

Fujihara, Junko; Kinoshita, Hiroshi; Tanaka, Naoko; Yasuda, Toshihiro; Takeshita, Haruo

2013-07-01

The measurement of blood carboxyhemoglobin (CO-Hb) is important to determine the cause of death. The AVOXimeter 4000 (AVOX), a portable CO-oximeter, has the advantages of a low purchase price and operating cost, ease of operation, and rapid results. Little information is available on the usefulness of AVOX in the forensic sample, and the previous study investigated only six samples. Therefore, in this study, we confirmed the usefulness of the AVOX through a comparison of its results with data previously obtained using the double wavelength spectrophotometric method in autopsies. Regression analysis was performed between CO-Hb levels measured by the AVOX and those measured by the conventional double wavelength spectrophotometric method in postmortem blood samples: a significant correlation was observed. This study suggests the usefulness of the AVOX to analyze postmortem blood, and the AVOX is suitable for routine forensic analysis and can be applied at the crime scene. © 2013 American Academy of Forensic Sciences.

Performance of CO2 enrich CNG in direct injection engine

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

CONCEPTUAL DESIGN ASSESSMENT FOR THE CO-FIRING OF BIO-REFINERY SUPPLIED LIGNIN PROJECT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ted Berglund; Jeffrey T. Ranney; Carol L. Babb

2001-01-01

The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates have been completed and issued for review. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter. Initial pilot facility shakedown was completed during the fourth quarter. During pilot plant shakedown operations, several production batch test runs were performed. These pilot tests were coupled with laboratory testing to confirm pilot results. In initial batches of operations, cellulose to glucose conversionsmore » of 62.5% and 64.8% were observed in laboratory hydrolysis. As part of this testing, lignin dewatering was tested using laboratory and vendor-supplied filtration equipment. Dewatering tests reported moisture contents in the lignin of between 50% and 60%. Dewatering parameters and options will continue to be investigated during lignin production. After some unavoidable delays, a suitable representative supply of MSW feed material was procured. Shredding of the feed material was completed and final drying of the feed is expected to be completed by late January. Once feed drying is completed, pilot facility production will begin to produce lignin for co-fire testing. Facility modifications are expected to continue to improve facility operations and performance during the first quarter of 2001. The TVA-Colbert facility continues to make progress in evaluating the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing has been completed and no major impacts have been identified. Detailed assessment of steam export impacts on the Colbert boiler system continues.« less

SpaceOps 2012 Plus 2: Social Tools to Simplify ISS Flight Control Communications and Log Keeping

NASA Technical Reports Server (NTRS)

Cowart, Hugh S.; Scott, David W.

2014-01-01

A paper written for the SpaceOps 2012 Conference (Simplify ISS Flight Control Communications and Log Keeping via Social Tools and Techniques) identified three innovative concepts for real time flight control communications tools based on social mechanisms: a) Console Log Tool (CoLT) - A log keeping application at Marshall Space Flight Center's (MSFC) Payload Operations Integration Center (POIC) that provides "anywhere" access, comment and notifications features similar to those found in Social Networking Systems (SNS), b) Cross-Log Communication via Social Techniques - A concept from Johnsson Space Center's (JSC) Mission Control Center Houston (MCC-H) that would use microblogging's @tag and #tag protocols to make information/requests visible and/or discoverable in logs owned by @Destination addressees, and c) Communications Dashboard (CommDash) - A MSFC concept for a Facebook-like interface to visually integrate and manage basic console log content, text chat streams analogous to voice loops, text chat streams dedicated to particular conversations, generic and position-specific status displays/streams, and a graphically based hailing display. CoLT was deployed operationally at nearly the same time as SpaceOps 2012, the Cross- Log Communications idea is currently waiting for a champion to carry it forward, and CommDash was approved as a NASA Iinformation Technoloby (IT) Labs project. This paper discusses lessons learned from two years of actual CoLT operations, updates CommDash prototype development status, and discusses potential for using Cross-Log Communications in both MCC-H and/or POIC environments, and considers other ways for synergizing console applcations.

A symbiotic gas exchange between bioreactors enhances microalgal biomass and lipid productivities: taking advantage of complementary nutritional modes.

PubMed

Santos, C A; Ferreira, M E; da Silva, T Lopes; Gouveia, L; Novais, J M; Reis, A

2011-08-01

This paper describes the association of two bioreactors: one photoautotrophic and the other heterotrophic, connected by the gas phase and allowing an exchange of O(2) and CO(2) gases between them, benefiting from a symbiotic effect. The association of two bioreactors was proposed with the aim of improving the microalgae oil productivity for biodiesel production. The outlet gas flow from the autotrophic (O(2) enriched) bioreactor was used as the inlet gas flow for the heterotrophic bioreactor. In parallel, the outlet gas flow from another heterotrophic (CO(2) enriched) bioreactor was used as the inlet gas flow for the autotrophic bioreactor. Aside from using the air supplied from the auto- and hetero-trophic bioreactors as controls, one mixotrophic bioreactor was also studied and used as a model, for its claimed advantage of CO(2) and organic carbon being simultaneously assimilated. The microalga Chlorella protothecoides was chosen as a model due to its ability to grow under different nutritional modes (auto, hetero, and mixotrophic), and its ability to attain a high biomass productivity and lipid content, suitable for biodiesel production. The comparison between heterotrophic, autotrophic, and mixotrophic Chlorella protothecoides growth for lipid production revealed that heterotrophic growth achieved the highest biomass productivity and lipid content (>22%), and furthermore showed that these lipids had the most suitable fatty acid profile in order to produce high quality biodiesel. Both associations showed a higher biomass productivity (10-20%), when comparing the two separately operated bioreactors (controls) which occurred on the fourth day. A more remarkable result would have been seen if in actuality the two bioreactors had been inter-connected in a closed loop. The biomass productivity gain would have been 30% and the lipid productivity gain would have been 100%, as seen by comparing the productivities of the symbiotic assemblage with the sum of the two bioreactors operating separately (controls). These results show an advantage of the symbiotic bioreactors association towards a cost-effective microalgal biodiesel production.

Order Responding to May 10, 2001 Petition for the Administrator to Object to Consolidated Edison Co. of New York's Operating Permit

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

2002 Petition for the Administrator to Object to an Operating Permit for Dow Chemical Co. in Plaquemine, LA

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Order Responding to December 6, 2004 Request that the Administrator Object to Operating Permit for Valero Refining Co. in Benicia, CA

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Order Denying Petition to Object to Operating Permit for Maui Electric Co., Ltd., Maalaea Generating Station

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Order Responding to December 6, 2004 Request that the Administrator Object to Operating Permit for Tesoro Refining and Marketing Co. in Martinez, CA

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Lincolnway Energy Cooperative and Co-location with Existing Grain Cooperative

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Policy and Guidance Database available at www2.epa.gov/title-v-operating-permits/title-v-operating-permit-policy-and-guidance-document-index. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Capturing and portraying science student teachers' pedagogical content knowledge through CoRe construction

NASA Astrophysics Data System (ADS)

Thongnoppakun, Warangkana; Yuenyong, Chokchai

2018-01-01

Pedagogical content knowledge (PCK) is an essential kind of knowledge that teacher have for teaching particular content to particular students for enhance students' understanding, therefore, teachers with adequate PCK can give content to their students in an understandable way rather than transfer subject matter knowledge to learner. This study explored science student teachers' PCK for teaching science using Content representation base methodology. Research participants were 68 4th year science student teachers from department of General Science, faculty of Education, Phuket Rajabhat University. PCK conceptualization for teaching science by Magnusson et al. (1999) was applied as a theoretical framework in this study. In this study, Content representation (CoRe) by Loughran et al. (2004) was employed as research methodology in the lesson preparation process. In addition, CoRe consisted of eight questions (CoRe prompts) that designed to elicit and portray teacher's PCK for teaching science. Data were collected from science student teachers' CoRes design for teaching a given topic and student grade. Science student teachers asked to create CoRes design for teaching in topic `Motion in one direction' for 7th grade student and further class discussion. Science student teachers mostly created a same group of science concepts according to subunits of school science textbook rather than planned and arranged content to support students' understanding. Furthermore, they described about the effect of student's prior knowledge and learning difficulties such as students' knowledge of Scalar and Vector quantity; and calculating skill. These responses portrayed science student teacher's knowledge of students' understanding of science and their content knowledge. However, they still have inadequate knowledge of instructional strategies and activities for enhance student learning. In summary, CoRes design can represented holistic overviews of science student teachers' PCK related to the teaching of a particular topic and also support them to gain more understanding about how to teach for understanding. Research implications are given for teacher education and educational research to offer a potential way to enhance science student teachers' PCK for teaching science and support their professional learning.

Chemical and biological methods to evaluate the availability of heavy metals in soils of the Siena urban area (Italy).

PubMed

Nannoni, Francesco; Protano, Giuseppe

2016-10-15

A biogeochemistry field study was conducted in the Siena urban area (Italy) with the main objective of establishing the relationship between available amounts of heavy metals in soil assessed by a chemical method (soil fractionation) and bioavailability assessed by a biological method (bioaccumulation in earthworm tissues). The total content of traffic-related (Cd, Cu, Pb, Sb, Zn) and geogenic (Co, Cr, Ni, U) heavy metals in uncontaminated and contaminated soils and their concentrations in soil fractions and earthworms were used for this purpose. The bioavailability of heavy metals assessed by earthworms did not always match the availability defined by soil fractionation. Earthworms were a good indicator to assess the bioavailability of Pb and Sb in soil, while due to physiological mechanisms of regulation and excretion, Cd, Cu and Zn tissue levels in these invertebrates gave misleading estimates of their bioavailable pool. No relationship was identified between chemical and biological availability for the geogenic heavy metals, characterized by a narrow range of total contents in soil. The study highlighted that chemical and biological methods should be combined to provide more complete information about heavy element bioavailability in soils. Copyright © 2016 Elsevier B.V. All rights reserved.

In vivo operation of the pentose phosphate pathway in frog oocytes is limited by NADP+ availability.

PubMed

Preller, A; Guixé, V; Ureta, T

1999-03-05

Evolution of CO2 from labelled glucose microinjected into frog oocytes in vivo may be ascribed to the pentose-P pathway, as measured by radioactive CO2 production from [1-(14)C] and [6-(14)C]glucose. Coinjection of NADP+ and [14C]glucose significantly stimulated 14CO2 production. The effect depends on the amount of NADP+ injected, half maximal stimulation being obtained at 0.13 mM. The increase in CO2 production was also observed with microinjected glucose-1-P, glucose-6-P or fructose-6-P used as substrates. Phenazine methosulfate, mimicked the effects of NADP+. A high NADPH/NADP+ ratio of 4.3 was found in the cells, the intracellular concentration of NADP+ being 19 microM.

Validation of AIRS Retrievals of CO2 via Comparison to In Situ Measurements

NASA Technical Reports Server (NTRS)

Olsen, Edward T.; Chahine, Moustafa T.; Chen, Luke L.; Jiang, Xun; Pagano, Thomas S.; Yung, Yuk L.

2008-01-01

Topics include AIRS on Aqua, 2002-present with discussion about continued operation to 2011 and beyond and background, including spectrum, weighting functions, and initialization; comparison with aircraft and FTIR measurements in Masueda (CONTRAIL) JAL flask measurements, Park Falls, WI FTIR, Bremen, GDF, and Spitsbergen, Norway; AIRS retrievals over addition FTIR sites in Darwin, AU and Lauder, NZ; and mid-tropospheric carbon dioxide weather and contribution from major surface sources. Slide titles include typical AIRS infrared spectrum, AIRS sensitivity for retrieving CO2 profiles, independence of CO2 solution with respect to the initial guess, available in situ measurements for validation and comparison, comparison of collocated V1.5x AIRS CO2 (N_coll greater than or equal to 9) with INTEX-NA and SPURT;

Commission on the National Guard and Reserves: Transforming the National Guard and Reserves into a 21st-Century Operational Force

DTIC Science & Technology

2008-01-31

13DecForesmanCNGRTestimonyFINAL%5B1%5D.pdf), p. 3. Representatives Skelton and Taylor at March 2006 hearing. COMMISSION ON THE NATIONAL GUARD AND RESERVES 57 CREATING...Anniversary,” CMH Pub 72-32 (U.S. Army Center of Military History, 1995), available at www.army.mil/cmh-pg/documents/mobpam.htm. 8 Abbott A. Brayton ...Services Committee Representative Gene Taylor , Co-Chair, House National Guard and Reserve Components Caucus Representative Steve Buyer, Co-Chair, House

Monolayer dispersion of CoO on Al2O3 probed by positronium atom

NASA Astrophysics Data System (ADS)

Liu, Z. W.; Zhang, H. J.; Chen, Z. Q.

2014-02-01

CoO/Al2O3 catalysts were prepared by wet impregnation method with CoO contents ranging from 0 wt% to 24 wt%. X-ray diffraction and X-ray photoelectron spectroscopy measurements suggest formation of CoO after calcined in N2. Quantitative X-ray diffraction analysis indicates monolayer dispersion capacity of CoO in CoO/Al2O3 catalysts to be about 3 wt%. Positron annihilation lifetime and coincidence Doppler broadening measurements were performed to study the dispersion state of CoO on Al2O3. The positron lifetime measurements reveal two long lifetime components τ3 and τ4, which correspond to ortho-positronium annihilation lifetime in microvoids and large pores, respectively. It was found that the positronium atom is very sensitive to the dispersion state of CoO on Al2O3. The presence of CoO significantly decreases both the lifetime and the intensity of τ4. Detailed analysis of the coincidence Doppler broadening measurements suggests that with the CoO content lower than the monolayer dispersion, spin conversion reaction of positronium is induced by CoO. When the cobalt content is higher than the monolayer dispersion capacity, inhibition of positronium formation becomes the dominate effect.

Hexavalent chromium content in stainless steel welding fumes is dependent on the welding process and shield gas type.

PubMed

Keane, Michael; Stone, Samuel; Chen, Bean; Slaven, James; Schwegler-Berry, Diane; Antonini, James

2009-02-01

Occupational exposure to welding fumes is a known health hazard. To isolate elements in stainless steel welding fumes with high potential for adverse health outcomes, fumes were generated using a robotic gas metal arc system, using four shield gases of varying oxygen content. The objective was to measure Cr(VI) concentrations in a broad spectrum of gas metal arc welding processes, and identify processes of exceptionally high or low Cr(VI) content. The gases used were 95% Ar/5% O(2), 98% Ar/2% O(2), 95% Ar/5%CO(2), and 75% He/25% Ar. The welder was operated in axial spray mode (Ar/O(2), Ar/CO(2)), short-circuit (SC) mode (Ar/CO(2) low voltage and He/Ar), and pulsed axial-spray mode (98% Ar/2% O(2)). Results indicate large differences in Cr(VI) in the fumes, with Ar/O(2) (Pulsed)>Ar/O(2)>Ar/CO(2)>Ar/CO(2) (SC)>He/Ar; values were 3000+/-300, 2800+/-85, 2600+/-120, 1400+/-190, and 320+/-290 ppm respectively (means +/- standard errors for 2 runs and 3 replicates per run). Respective rates of Cr(VI) generation were 1.5, 3.2, 4.4, 1.3, and 0.46 microg/min; generation rates were also calculated in terms of microg Cr(VI) per metre of wire used. The generation rates of Cr(VI) increased with increasing O(3) concentrations. Particle size measurements indicated similar distributions, but somewhat higher >0.6 microm fractions for the short-circuit mode samples. Fumes were also sampled into 2 selected size ranges, a microspatter fraction (>or=0.6 microm) and a fine (<0.6 microm) fraction; analysis indicated that Cr(VI) is primarily associated with particles <0.6 microm. The conclusion of the study is that Cr(VI) concentrations vary significantly with welding type and shield gas type, and this presents an opportunity to tailor welding practices to lessen Cr(VI) exposures in workplaces by selecting low Cr(VI)-generating processes. Short-circuit processes generated less Cr(VI) than axial-spray methods, and inert gas shielding gave lower Cr(VI) content than shielding with active gases. A short circuit He/Ar shielded process and a pulsed axial spray Ar/O(2) process were both identified as having substantially lower Cr(VI) generation rates per unit of wire used relative to the other processes studied.

Mineral Control of Soil Carbon Dynamics in Forest Soils: A Lithosequence Under Ponderosa Pine

NASA Astrophysics Data System (ADS)

Heckman, K. A.; Welty-Bernard, A.; Rasmussen, C.; Schwartz, E.; Chorover, J.

2008-12-01

The role of soil organic carbon in regulating atmospheric CO2 concentration has spurred interest in both quantifying existing soil C stocks and modeling the behavior of soil C under climate change scenarios. Soil parent material exerts direct control over soil organic carbon content through its influence on soil pH and mineral composition. Soil acidity and mineral composition also influence soil microbial community composition and activity, thereby controlling soil respiration rates and microbial biomass size. We sampled a lithosequence of four parent materials (rhyolite, granite, basalt, limestone) under Pinus ponderosa to examine the effects of soil mineralogy and acidity on soil organic carbon content and soil microbial community. Three soil profiles were examined on each parent material and analyzed by X-ray diffraction, pH, selective dissolution, C and N content, and 13C signature. Soils from each of the four parent materials were incubated for 40 days, and microbial communities were compared on the basis of community composition (as determined through T-RFLP analysis), specific metabolic activity, biomass, δ13C of respired CO2, and cumulative amount of C mineralized over the course of the incubation. Soil C content varied significantly among soils of different parent material, and was strongly and positively associated with the abundance of Al-humus complexes r2 = 0.71; P < 0.0001, Fe-humus complexes r2 = 0.74; P = 0.0003, and crystalline Fe-oxide content r2 = 0.63; P = 0.0023. Microbial community composition varied significantly among soils and showed strong associations with soil pH 1:1 in KCl; r2 = 0.87; P < 0.0001, concentration of exchangeable Al r2 = 0.81; P < 0.0001, amorphous Fe oxide content r2 = 0.59; P < 0.004, and Al-humus content r2 = 0.35; P < 0.04. Mineralization rates, biomass and δ13C of respired CO2 differed among parent materials, and also varied with incubation time as substrate quality and N availability changed. The results demonstrate that within a specific ecosystem type, soil parent material exerts significant control over the lability and bioavailability of soil C and soil microbial community composition. We suggest that soil parent material and mineralogy are critical parameters for predicting soil C dynamics and recalcitrance of soil C stocks.

Can plants grow in quasi-vacuum?

NASA Technical Reports Server (NTRS)

Andre, M.; Richaud, C.

1986-01-01

It was found that the growth of plants is possible under absolute pressure 14 times lower than the atmospheric pressure. In first approximation, plants ignore the absence of nitrogen and only react to the partial pressure of O2. Hence the growth of plantlets was delayed under low pressures of O2 in both cases with and without nitrogen. The CO2 availability being limited by the carbon content of the seed, the final results after 20 days were very similar.

Delayed Detection of Esophageal Intubation in Anesthesia Malpractice Claims: Brief Report of a Case Series.

PubMed

Honardar, Marzieh R; Posner, Karen L; Domino, Karen B

2017-12-01

This retrospective case series analyzed 45 malpractice claims for delayed detection of esophageal intubation from the Anesthesia Closed Claims Project. Inclusion criteria were cases from 1995 to 2013, after adoption of identification of CO2 in expired gas to verify correct endotracheal tube position as a monitoring standard by the American Society of Anesthesiologists. Forty-nine percent (95% confidence interval 34%-64%) occurred in the operating room or other anesthesia location where CO2 detection equipment should have been available. The most common factors contributing to delayed detection were not using, ignoring, or misinterpreting CO2 readings. Misdiagnosis, as with bronchospasm, occurred in 33% (95% confidence interval 20%).

Effect of variation in argon content of calibration gases on determination of atmospheric carbon dioxide.

PubMed

Min, Deullae; Kang, Namgoo; Moon, Dong Min; Lee, Jin Bok; Lee, Dong Soo; Kim, Jin Seog

2009-12-15

Carbon dioxide (CO(2)) is a greenhouse gas that makes by far the largest contribution to the global warming of the Earth's atmosphere. For the measurements of atmospheric CO(2) a non-dispersive infrared analyzer (NDIR) and gas chromatography are conventionally being used. We explored whether and to what degree argon content can influence the determination of atmospheric CO(2) using the comparison of CO(2) concentrations between the sample gas mixtures with varying Ar amounts at 0 and 18.6 mmol mol(-1) and the calibration gas mixtures with Ar at 8.4, 9.1, and 9.3 mmol mol(-1). We newly discovered that variation of Ar content in calibration gas mixtures could undermine accuracy for precise and accurate determination of atmospheric CO(2) in background air. The differences in CO(2) concentration due to the variation of Ar content in the calibration gas mixtures were negligible (<+/-0.03 micromol mol(-1)) for NDIR systems whereas they noticeably increased (<+/-1.09 micromol mol(-1)) especially for the modified GC systems to enhance instrumental sensitivity. We found that the thermal mass flow controller is the main source of the differences although such differences appeared only in the presence of a flow restrictor in GC systems. For reliable monitoring of real atmospheric CO(2) samples, one should use calibration gas mixtures that contain Ar content close to the level (9.332 mmol mol(-1)) in the ambient air as possible. Practical guidelines were highlighted relating to selection of appropriate analytical approaches for the accurate and precise measurements of atmospheric CO(2). In addition, theoretical implications from the findings were addressed.

Combustion characteristics of paper and sewage sludge in a pilot-scale fluidized bed.

PubMed

Yu, Yong-Ho; Chung, Jinwook

2015-01-01

This study characterizes the combustion of paper and sewage sludge in a pilot-scale fluidized bed. The highest temperature during combustion within the system was found at the surface of the fluidized bed. Paper sludge containing roughly 59.8% water was burned without auxiliary fuel, but auxiliary fuel was required to incinerate the sewage sludge, which contained about 79.3% water. The stability of operation was monitored based on the average pressure and the standard deviation of pressure fluctuations. The average pressure at the surface of the fluidized bed decreased as the sludge feed rate increased. However, the standard deviation of pressure fluctuations increased as the sludge feed rate increased. Finally, carbon monoxide (CO) emissions decreased as oxygen content increased in the flue gas, and nitrogen oxide (NOx) emissions were also tied with oxygen content.

In situ measurements of fuel retention by laser induced desorption spectroscopy in TEXTOR

NASA Astrophysics Data System (ADS)

Zlobinski, M.; Philipps, V.; Schweer, B.; Huber, A.; Stoschus, H.; Brezinsek, S.; Samm, U.; TEXTOR Team

2011-12-01

In future fusion devices such as ITER tritium retention due to tritium co-deposition in mixed material layers can be a serious safety problem. Laser induced desorption spectroscopy (LIDS) can measure the hydrogen content of hydrogenic carbon layers locally on plasma-facing components, while hydrogen is used as a tritium substitute. For several years, this method has been applied in the TEXTOR tokamak in situ during plasma operation to monitor the hydrogen content in space and time. This work shows the LIDS signal reproducibility and studies the effects of different plasma conditions, desorption distances from the plasma and different laser energies using a dedicated sample with constant hydrogen amount. Also the LIDS signal evaluation procedure is described in detail and the detection limits for different conditions in the TEXTOR tokamak are estimated.

IAEA international studies on irradiation embrittlement of reactor pressure vessel steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brumovsky, M.; Steele, L.E.

1997-02-01

In last 25 years, three phases a Co-operative Research Programme on Irradiation Embrittlement of Reactor Pressure Vessel Steels has been organized by the International Atomic Energy Agency. This programme started with eight countries in 1971 and finally 16 countries took part in phase III of the Programme in 1983. Several main efforts were put into preparation of the programme, but the principal task was concentrated on an international comparison of radiation damage characterization by different laboratories for steels of {open_quotes}old{close_quotes} (with high impurity contents) and {open_quotes}advanced{close_quotes} (with low impurity contents) types as well as on development of small scale fracturemore » mechanics procedures applicable to reactor pressure vessel surveillance programmes. This year, a new programme has been opened, concentrated mostly on small scale fracture mechanics testing.« less

Upcrowding energy co-operatives - Evaluating the potential of crowdfunding for business model innovation of energy co-operatives.

PubMed

Dilger, Mathias Georg; Jovanović, Tanja; Voigt, Kai-Ingo

2017-08-01

Practice and theory have proven the relevance of energy co-operatives for civic participation in the energy turnaround. However, due to a still low awareness and changing regulation, there seems an unexploited potential of utilizing the legal form 'co-operative' in this context. The aim of this study is therefore to investigate the crowdfunding implementation in the business model of energy co-operatives in order to cope with the mentioned challenges. Based on a theoretical framework, we derive a Business Model Innovation (BMI) through crowdfunding including synergies and differences. A qualitative study design, particularly a multiple-case study of energy co-operatives, was chosen to prove the BMI and to reveal barriers. The results show that although most co-operatives are not familiar with crowdfunding, there is strong potential in opening up predominantly local structures to a broader group of members. Building on this, equity-based crowdfunding is revealed to be suitable for energy co-operatives as BMI and to accompany other challenges in the same way. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR 90.312 - Analytical gases.

Code of Federal Regulations, 2010 CFR

2010-07-01

... contentration must be between 0 and 1 percent O2. Nitrogen must be the predominant diluent with the balance... available for operation: (1) Purified nitrogen, also refered to as “zero-grade nitrogen” (Contamination ≤ 1...) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance helium) (Contamination ≤ 1 ppm C, ≤ 400 ppm CO...

40 CFR 90.312 - Analytical gases.

Code of Federal Regulations, 2011 CFR

2011-07-01

... contentration must be between 0 and 1 percent O2. Nitrogen must be the predominant diluent with the balance... available for operation: (1) Purified nitrogen, also refered to as “zero-grade nitrogen” (Contamination ≤ 1...) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance helium) (Contamination ≤ 1 ppm C, ≤ 400 ppm CO...

40 CFR 90.312 - Analytical gases.

Code of Federal Regulations, 2012 CFR

2012-07-01

... contentration must be between 0 and 1 percent O2. Nitrogen must be the predominant diluent with the balance... available for operation: (1) Purified nitrogen, also refered to as “zero-grade nitrogen” (Contamination ≤ 1...) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance helium) (Contamination ≤ 1 ppm C, ≤ 400 ppm CO...

40 CFR 90.312 - Analytical gases.

Code of Federal Regulations, 2013 CFR

2013-07-01

... contentration must be between 0 and 1 percent O2. Nitrogen must be the predominant diluent with the balance... available for operation: (1) Purified nitrogen, also referred to as “zero-grade nitrogen” (Contamination ≤ 1...) Hydrogen-helium mixture (40 ±2 percent hydrogen, balance helium) (Contamination ≤ 1 ppm C, ≤ 400 ppm CO...

Graduations on the Rise

ERIC Educational Resources Information Center

Murnane, Richard J.; Hoffman, Stephen L.

2013-01-01

Between 1970 and 2000, the U.S. high-school graduation stagnated while in many other Organization for Economic Co-operation and Development (OECD) countries it rose markedly. By 2000, the high school graduation rate in the United States ranked 13th among the 19 OECD countries for which comparable data are available. Evidence from two independent…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hummon, M.; Kiliccote, S.

Demand response (DR) resources present a potentially important source of grid flexibility however, DR in grid models is limited by data availability and modeling complexity. This presentation focuses on the co-optimization of DR resources to provide energy and ancillary services in a production cost model of the Colorado "test system". We assume each DR resource can provide energy services by either shedding load or shifting its use between different times, as well as operating reserves: frequency regulation, contingency reserve, and flexibility (or ramping) reserve. There are significant variations in the availabilities of different types of DR resources, which affect bothmore » the operational savings as well as the revenue for each DR resource. The results presented include the system-wide avoided fuel and generator start-up costs as well as the composite revenue for each DR resource by energy and operating reserves.« less

Tele-Manipulation with Two Asymmetric Slaves: Two Operators Perform Better Than One.

PubMed

van Oosterhout, Jeroen; Heemskerk, Cock J M; de Baar, Marco R; van der Helm, Frans C T; Abbink, David A

2018-01-01

Certain tele-manipulation tasks require manipulation by two asymmetric slaves, for example, a crane for hoisting and a dexterous robotic arm for fine manipulation. It is unclear how to best design human-in-the-loop control over two asymmetric slaves. The goal of this paper is to quantitatively compare the standard approach of two co-operating operators that each control a single subtask, to a single operator performing bi-manual control over the two subtasks, and a uni-manual control approach. In a human factors experiment, participants performed a heavy load maneuvering and mounting task using a vertical crane and a robotic arm. We hypothesize that bi-manual control yields worse task performance and control activity compared to co-operation, because of conflicting spatial and temporal constraints. Literature suggests that uni-manual operators should perform better than co-operation, as co-operators critically depend on each other's actions. However, other literature provides evidence that individual operators have limited capabilities in controlling asymmetric axes of two dynamic systems. The results show that the two co-operators perform the maneuvering and mounting task faster than either bi- or uni-manual operators. Compared to co-operators, uni-manual operators required more control activity for the vertical crane and less for the robotic arm. In conclusion, this study suggests that when controlling two asymmetric slaves, a co-operating pair of operators performs better than a single operator.

Influence of System Operation Method on CO2 Emissions of PV/Solar Heat/Cogeneration System

NASA Astrophysics Data System (ADS)

Oke, Shinichiro; Kemmoku, Yoshishige; Takikawa, Hirofumi; Sakakibara, Tateki

A PV/solar heat/cogeneration system is assumed to be installed in a hotel. The system is operated with various operation methods: CO2 minimum operation, fees minimum operation, seasonal operation, daytime operation and heat demand following operation. Of these five operations, the former two are virtual operations that are operated with the dynamic programming method, and the latter three are actual operations. Computer simulation is implemented using hourly data of solar radiation intensity, atmospheric temperature, electric, cooling, heating and hot water supply demands for one year, and the life-cycle CO2 emission and the total cost are calculated for every operations. The calculation results show that the virtual two and the actual three operations reduce the life-cycle CO2 emission by 21% and 13% compared with the conventional system, respectively. In regard to both the CO2 emission and the cost, there is no significant difference between the virtual two operation methods or among actual three operation methods.

Protein Concentrate Production from Thin Stillage.

PubMed

Ratanapariyanuch, Kornsulee; Shim, Youn Young; Emami, Shahram; Reaney, Martin J T

2016-12-21

Two-stage fermentation (TSF) of saccharified wheat with a consortium of endemic lactobacilli produced CO 2 and induced colloid separation of fermented solution to produce a protein concentrate (PC). Protein-rich slurry (50%, db) was obtained by decanting solution or skimming floating material during or after TSF. Washing and drying processes were explored to improve protein content, extend storage life of slurry, and yield converted stillage for compound recovery. Centrifuging and washing slurry afforded a PC and clarified solution. PC protein content increased to 60% (w/w, db). The PC was dried in a spray dryer or drum dryer or tray dryer. Dried PC water activity ranged 0.23-0.30. The dried PC lysine content was low, but lysine availability (95%) was excellent. Liquid from TSF and washing was readily microfiltered. Mass recovery of protein, glycerol, 1,3-propanediol, lactic acid, acetic acid, and glycerylphosphorylcholine from combined TSF, washing, and filtration were 66, 76, 72, 77, 74, and 84%, respectively.

Developing AJN Network: phase two. An information resource for nurses.

PubMed Central

Rizzolo, M. A.; DuBois, K.

1995-01-01

In September of 1993 the American Journal of Nursing Company was awarded a three-year Special Projects Grant from the Division of Nursing, Department of Health and Human Services to develop a national information service that would provide a variety of formal and informal continuing education services to nurses in medically underserved communities. AJN Network went "live" in March 1994 and our progress in our first year of operation was presented at SCAMC in 1994. During the first year of operation, AJN Network was available through a dial in service. In September 1994 we became an Internet node. This presentation will detail our progress in Year 2 of the grant period, describing expansion of user base and content, new content offerings, initial stages of WEB development and plans for future development. PMID:8563246

[Influence of accessories mixing ratio on sludge biophysical co-drying].

PubMed

Yang, Jin-Long; Du, Qiong; Li, Dong; Han, Rong; Zhao, Yan; Wang, Hong-Tao

2011-08-01

Parameters (temperature, water content and so on) in the process of sludge biophysical co-drying were studied in self-made biophysical co-drying reactor. The sludge: tree bark: recycled sludge was set as 7: 3: 0.5, 9: 3: 0.5, 12: 3: 0.5 respectively. The results suggested that sludge temperature first increased then decreased along with drying time, water content decreased in the first 96 h, then had no obvious variability. While sludge: tree bark: recycled sludge was 9: 3: 0.5, the temperature of sludge spiraling, received to max 67 degrees C at 48 h under three different accessories mixture ratio, and was kept for 72 h above 55 degrees C, then spiraling, the final water content of sludge decreased from 74.1% to 61.8%, received the optimal water content removing rate 43.5%. Accessories mixing ratio had important influence on the process of sludge biophysical co-drying, sludge with proper mixing ratio can modify the structure of sludge, improve sludge permeability, arouse and keep microorganic activity, which will enhance sludge temperature and strengthen water content removal rate.

Co-culture with infrapatellar fat pad differentially stimulates proteoglycan synthesis and accumulation in cartilage and meniscus tissues.

PubMed

Nishimuta, James F; Bendernagel, Monica F; Levenston, Marc E

2017-09-01

Although osteoarthritis is widely viewed as a disease of the whole joint, relatively few studies have focused on interactions among joint tissues in joint homeostasis and degeneration. In particular, few studies have examined the effects of the infrapatellar fat pad (IFP) on cartilaginous tissues. The aim of this study was to test the hypothesis that co-culture with healthy IFP would induce degradation of cartilage and meniscus tissues. Bovine articular cartilage, meniscus, and IFP were cultured isolated or as cartilage-fat or meniscus-fat co-cultures for up to 14 days. Conditioned media were assayed for sulfated glycosaminoglycan (sGAG) content, nitrite content, and matrix metalloproteinase (MMP) activity, and explants were assayed for sGAG and DNA contents. Co-cultures exhibited increased cumulative sGAG release and sGAG release rates for both cartilage and meniscus, and the cartilage (but not meniscus) exhibited a substantial synergistic effect of co-culture (sGAG release in co-culture was significantly greater than the summed release from isolated cartilage and fat). Fat co-culture did not significantly alter the sGAG content of either cartilage or meniscus explants, indicating that IFP co-culture stimulated net sGAG production by cartilage. Nitrite release was increased relative to isolated tissue controls in co-cultured meniscus, but not the cartilage, with no synergistic effect of co-culture. Interestingly, MMP-2 production was decreased by co-culture for both cartilage and meniscus. This study demonstrates that healthy IFP may modulate joint homeostasis by stimulating sGAG production in cartilage. Counter to our hypothesis, healthy IFP did not promote degradation of either cartilage or meniscus tissues.

Al3+ ions dependent structural and magnetic properties of Co-Ni nano-alloys.

PubMed

Kadam, R H; Alone, Suresh T; Gaikwad, Anil S; Birajdar, A P; Shirsath, Sagar E

2014-06-01

Ferrite samples with a chemical formula Co0.5Ni0.5Al(x)Fe(2-x)O4 (where x = 0.0, 0.25, 0.5, 0.75 and 1.0) were synthesized by sol-gel auto-combustion method. The synthesized samples were annealed at 600 degrees C for 4 h. An analysis of X-ray diffraction (XRD) patterns reveals the formation of single phase cubic spinel structure. The lattice parameter decreased linearly with the increasing Al content x. Nano size of the powders were confirmed by the transmission electron micrographs (TEM). Particle size, bulk density decreased whereas specific surface area and porosity of the samples increased with the Al substitution. Cation distribution of constituent ions shows linear dependence of Al substitution. Based on the cation distribution obtained from XRD data, structural parameters such as lattice parameters, ionic radii of available sites and the oxygen parameter 'u' is calculated. Saturation magnetization (M(s)), magneton number (n(B)) and coercivity (H(c)) decreased with the Al substitution. Possible explanation for the observed structural and magnetic behavior with various Al content are discussed.

Decrease in hydrogen sulfide content during the final stage of beer fermentation due to involvement of yeast and not carbon dioxide gas purging.

PubMed

Oka, Kaneo; Hayashi, Teruhiko; Matsumoto, Nobuya; Yanase, Hideshi

2008-09-01

We observed a rapid decrease in hydrogen sulfide content in the final stage of beer fermentation that was attributed to yeast and not to the purging of carbon dioxide (CO(2)) gas. The well known immature off-flavor in beer due to hydrogen sulfide (H(2)S) behavior during beer fermentation was closely investigated. The H(2)S decrease occurred during the final stage of fermentation when the CO(2)-evolution rate was extremely small and there was a decrease in the availability of fermentable sugars, suggesting that the exhaustion of fermentable sugars triggered the decrease in H(2)S. An H(2)S-balance analysis suggested that the H(2)S decrease might have been caused due to sulfide uptake by yeast. Further investigation showed that the time necessary for H(2)S to decrease below the sensory threshold was related to the number of suspended yeast cells. This supported the hypothesis that yeast cells contributed to the rapid decrease in H(2)S during the final stage of beer fermentation.

Responses of Landoltia punctata to cobalt and nickel: Removal, growth, photosynthesis, antioxidant system and starch metabolism.

PubMed

Guo, Ling; Ding, Yanqiang; Xu, Yaliang; Li, Zhidan; Jin, Yanling; He, Kaize; Fang, Yang; Zhao, Hai

2017-09-01

Landoltia punctata has been considered as a potential bioenergy crop due to its high biomass and starch yields in different cultivations. Cobalt and nickel are known to induce starch accumulation in duckweed. We monitored the growth rate, net photosynthesis rate, total chlorophyll content, Rubisco activity, Co 2+ and Ni 2+ contents, activity of antioxidant enzymes, starch content and activity of related enzymes under various concentrations of cobalt and nickel. The results indicate that Co 2+ and Ni 2+ (≤0.5mgL -1 ) can facilitate growth in the beginning. Although the growth rate, net photosynthesis rate, chlorophyll content and Rubisco activity were significantly inhibited at higher concentrations (5mgL -1 ), the starch content increased sharply up to 53.3% dry weight (DW) in L. punctata. These results were attributed to the increase in adenosine diphosphate-glucose pyrophosphorylase (AGPase) and soluble starch synthase (SSS) activities and the decrease in α-amylase activity upon exposure to excess Co 2+ and Ni 2+ . In addition, a substantial increase in the antioxidant enzyme activities and high flavonoid contents in L. punctata may have largely resulted in the metal tolerance. Furthermore, the high Co 2+ and Ni 2+ contents (2012.9±18.8 and 1997.7±29.2mgkg -1 DW) in the tissue indicate that L. punctata is a hyperaccumulator. Thus, L. punctata can be considered as a potential candidate for the simultaneous bioremediation of Co 2+ - and Ni 2+ -polluted water and high-quality biomass production. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of Ni content on nanocrystalline Fe-Co-Ni ternary alloys synthesized by a chemical reduction method

NASA Astrophysics Data System (ADS)

Chokprasombat, Komkrich; Pinitsoontorn, Supree; Maensiri, Santi

2016-05-01

Magnetic properties of Fe-Co-Ni ternary alloys could be altered by changing of the particle size, elemental compositions, and crystalline structures. In this work, Fe50Co50-xNix nanoparticles (x=10, 20, 40, and 50) were prepared by the novel chemical reduction process. Hydrazine monohydrate was used as a reducing agent under the concentrated basic condition with the presence of poly(vinylpyrrolidone). We found that the nanoparticles were composed of Fe, Co and Ni with compositions according to the molar ratio of the metal sources. Interestingly, the particles were well-crystalline at the as-prepared state without post-annealing at high temperature. Increasing Ni content resulted in phase transformation from body centered cubic (bcc) to face centered cubic (fcc). For the fcc phase, the average particle size decreased when increased the Ni content; the Fe50Ni50 nanoparticles had the smallest average size with the narrowest size distribution. In additions, the particles exhibited ferromagnetic properties at room temperature with the coercivities higher than 300 Oe, and the saturation magnetiation decreased with increasing Ni content. These results suggest that the structural and magnetic properties of Fe-Co-Ni alloys could be adjusted by varying the Ni content.

Innovative soft magnetic multilayers with enhanced in-plane anisotropy and ferromagnetic resonance frequency for integrated RF passive devices

NASA Astrophysics Data System (ADS)

Falub, Claudiu V.; Bless, Martin; Hida, Rachid; MeduÅa, Mojmír; Ammann, Arnold

2018-04-01

We present an innovative, economical method for manufacturing soft magnetic materials that may pave the way for integrated thin film magnetic cores with dramatically improved properties. Soft magnetic multilayered thin films based on the Fe-28%Co20%B (at.%) and Co-4.5%Ta4%Zr (at.%) amorphous alloys are deposited on 8" bare Si and Si/200nm-thermal-SiO2 wafers in an industrial, high-throughput Evatec LLS EVO II magnetron sputtering system. The multilayers consist of stacks of alternating 80-nm-thick ferromagnetic layers and 4-nm-thick Al2O3 dielectric interlayers. Since in our dynamic sputter system the substrate cage rotates continuously, such that the substrates face different targets alternatively, each ferromagnetic sublayer in the multilayer consists of a fine structure comprising alternating CoTaZr and FeCoB nanolayers with very sharp interfaces. We adjust the thickness of these individual nanolayers between 0.5 and 1.5 nm by changing the cage rotation speed and the power of each gun, which is an excellent mode to engineer new, composite ferromagnetic materials. Using X-ray reflectometry (XRR) we reveal that the interfaces between the FeCoB and CoTaZr nanolayers are perfectly smooth with roughness of 0.2-0.3 nm. Kerr magnetometry and B-H looper measurements for the as-deposited samples show that the coercivity of these thin films is very low, 0.2-0.3 Oe, and gradually scales up with the thickness of FeCoB nanolayers, i.e. with the increase of the overall Fe content from 0 % (e.g. CoTaZr-based multilayers) to 52 % (e.g. FeCoB-based multilayers). We explain this trend in the random anisotropy model, based on considerations of grain size growth, as revealed by glancing angle X-ray diffraction (GAXRD), but also because of the increase of magnetostriction with the increase of Fe content as shown by B-H looper measurements performed on strained wafers. The unexpected enhancement of the in-plane anisotropy field from 18.3 Oe and 25.8 Oe for the conventional CoTaZr- and FeCoB-based multilayers, respectively, up to ˜48 Oe for the nanostructured multilayers with FeCoB/CoTaZr nano-bilayers is explained based on interface anisotropy contribution. These novel soft magnetic multilayers, with enhanced in-plane anisotropy, allow operation at higher frequencies, as revealed by broadband (between 100 MHz and 10 GHz) RF measurements that exhibit a classical Landau-Lifschitz-Gilbert (LLG) behavior.

Biomass consumption and CO2, CO and main hydrocarbon gas emissions in an Amazonian forest clearing fire

Treesearch

T.G. Soares Neto; J.A. Carvalho J.A.; C.A.G. Veras; E.C. Alvarado; R. Gielow; E.N. Lincoln; T.J. Christian; R.J. Yokelson; J.C. Santos

2009-01-01

Biomass consumption and C02, CO and hydrocarbon gas emissions in an Amazonian forest clearing fire are presented and discussed. The experiment was conducted in the arc of deforestation, near the city of Alta Floresta, state of Mato Grosso, Brazil. The average carbon content of dry biomass was 48 percent and the estimated average moisture content...

The Influence of Fuel Properties on Combustion Efficiency and the Partitioning of Pyrogenic Carbon

NASA Astrophysics Data System (ADS)

Urbanski, S. P.; Baker, S. P.; Lincoln, E.; Richardson, M.

2016-12-01

The partitioning of volatized pyrogenic carbon into CO2, CO, CH4, non-methane organic carbon, and particulate organic carbon (POC) and elemental carbon (PEC) depends on the combustion characteristics of biomass fires which are influenced by the moisture content, structure and arrangement of the fuels. Flaming combustion is characterized by efficient conversion of volatized carbon into CO2. In contrast, smoldering is less efficient and produces incomplete combustion products like CH4 and carbonaceous particles. This paper presents a laboratory study that has examined the relationship between the partitioning of volatized pyrogenic carbon and specific fuel properties. The study focused on fuel beds composed of simple fuel particles — ponderosa pine needles. Ponderosa pine was selected because it contains a common wildland fuel component, conifer needles, which can be easily arranged into fuel beds of variable structure (bulk density and depth) and moisture contents that are both representative of natural conditions and are easily replicated. Modified combustion efficiency (MCE, ΔCO2/[ΔCO2+ ΔCO]) and emission factors (EF) for CO2, CO, CH4, POC, and PEC were measured over a range of needle moisture content and fuel bed bulk density and depth representative of naturally occurring fuel beds. We found that, as expected, MCE decreases as the fuel bed bulk density increases and emissions of CO, CH4, PM2.5, and POC increased. However, fuel bed depth did not appear to have an effect on how effect on MCE or emission factors. Surprisingly, a consistent relationship between the needle moisture content and emissions was not identified. At the high bulk densities, moisture content had a strong influence on MCE which explained variability in EFCH4. However, moisture content appeared to have an influence EFPOC and EFPEC that was independent of MCE. These findings may have significant implications since many models of biomass burning assume that litter fuels, such as ponderosa pine needles, burn almost exclusively via flaming combustion with a high efficiency. Our results indicate that for fuel bed properties typical of many conifer forests, pollutants generated from fires will be higher than that predicted using standard biomass burning models.

Potential for cobalt recovery from lateritic ores in Europe

NASA Astrophysics Data System (ADS)

Herrington, R.

2012-04-01

Cobalt is one of the 'critical metals' identified under the EU Raw Materials Initiative. Annually the global mine production of cobalt is around 55,000 tonnes,with Europe's industries consuming around 30% of that figure. Currently Europe produces around 27 tonnes of cobalt from mines in Finland although new capacity is planned. Co-bearing nickel laterite ores being mined in Greece, Macedonia and Kosovo where the cobalt is currently not being recovered (ores have typical analyses of 0.055% Co and >1% Ni,). These ores are currently treated directly in pyrometallurgical plants to recover the contained nickel and this process means there is no separate cobalt product produced. Hydrometallurgical treatment of mineralogically suitable laterite ores can recover the cobalt; for example Cuba recovers 3,500 tonnes of cobalt from its laterite mining operations, which are of a similar scale to the current European operations. Implementation of hydrometallurgical techniques is in its infancy in Europe with one deposit in Turkey planning to use atmospheric heap leaching to recover nickel and copper from oxide-dominated ores. More widespread implementation of these methods to mineralogically suitable ore types could unlock the highly significant undeveloped resources (with metal contents >0.04% Co and >1% Ni), which have been defined throughout the Balkans eastwards into Turkey. At a conservative estimate, this region has the potential to supply up to 30% of the EU cobalt requirements.

40 CFR Table F-2 to Subpart F of... - Default Data Sources for Parameters Used for CO2 Emissions

Code of Federal Regulations, 2014 CFR

2014-07-01

... metric ton Al (metric tons C/metric tons Al) Individual facility records. Sa: sulfur content in baked anode (percent weight) 2.0. Asha: ash content in baked anode (percent weight) 0.4. CO2 Emissions From... records. Hw: annual hydrogen content in green anodes (metric tons) 0.005 × GA. BA: annual baked anode...

40 CFR Table F-2 to Subpart F of... - Default Data Sources for Parameters Used for CO2 Emissions

Code of Federal Regulations, 2013 CFR

2013-07-01

... metric ton Al (metric tons C/metric tons Al) Individual facility records. Sa: sulfur content in baked anode (percent weight) 2.0. Asha: ash content in baked anode (percent weight) 0.4. CO2 Emissions From... records. Hw: annual hydrogen content in green anodes (metric tons) 0.005 × GA. BA: annual baked anode...

40 CFR Table F-2 to Subpart F of... - Default Data Sources for Parameters Used for CO2 Emissions

Code of Federal Regulations, 2012 CFR

2012-07-01

... metric ton Al (metric tons C/metric tons Al) Individual facility records. Sa: sulfur content in baked anode (percent weight) 2.0. Asha: ash content in baked anode (percent weight) 0.4. CO2 Emissions From... records. Hw: annual hydrogen content in green anodes (metric tons) 0.005 × GA. BA: annual baked anode...

40 CFR Table F-2 to Subpart F of... - Default Data Sources for Parameters Used for CO2 Emissions

Code of Federal Regulations, 2011 CFR

2011-07-01

... metric ton Al (metric tons C/metric tons Al) Individual facility records. Sa: sulfur content in baked anode (percent weight) 2.0. Asha: ash content in baked anode (percent weight) 0.4. CO2 Emissions From... records. Hw: annual hydrogen content in green anodes (metric tons) 0.005 × GA. BA: annual baked anode...

Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests.

PubMed

Talhelm, Alan F; Pregitzer, Kurt S; Kubiske, Mark E; Zak, Donald R; Campany, Courtney E; Burton, Andrew J; Dickson, Richard E; Hendrey, George R; Isebrands, J G; Lewin, Keith F; Nagy, John; Karnosky, David F

2014-08-01

Three young northern temperate forest communities in the north-central United States were exposed to factorial combinations of elevated carbon dioxide (CO2 ) and tropospheric ozone (O3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity (NPP). Elevated CO2 enhanced ecosystem C content by 11%, whereas elevated O3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO2 and O3 . Treatment effects on ecosystem C content resulted primarily from changes in the near-surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content (r(2) = 0.96). Elevated CO2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m(-2) ) and a 28% increase in N productivity (NPP/canopy N). In contrast, elevated O3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆NPP/∆N) decreased through time with further canopy development, the O3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O3 and less soil C from 0.1 to 0.2 m in depth under elevated CO2 . Overall, these results suggest that elevated CO2 may create a sustained increase in NPP, whereas the long-term effect of elevated O3 on NPP will be smaller than expected. However, changes in soil C are not well-understood and limit our ability to predict changes in ecosystem C content. © 2014 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Warming and elevated CO 2 alter the suberin chemistry in roots of photosynthetically divergent grass species

DOE PAGES

Suseela, Vidya; Tharayil, Nishanth; Pendall, Elise; ...

2017-09-01

A majority of soil carbon (C) is either directly or indirectly derived from fine roots, yet roots remain the least understood component of the terrestrial carbon cycle. The decomposability of fine roots and their potential to contribute to soil C is partly regulated by their tissue chemical composition. Roots rely heavily on heteropolymers such as suberins, lignins and tannins to adapt to various environmental pressures and to maximize their resource uptake functions. Since the chemical construction of roots is partly shaped by their immediate biotic/abiotic soil environments, global changes that perturb soil resource availability and plant growth could potentially altermore » root chemistry, and hence the decomposability of roots. However, the effect of global change on the quantity and composition of root heteropolymers are seldom investigated. We examined the effects of elevated CO 2 and warming on the quantity and composition of suberin in roots of Bouteloua gracilis (C4) and Hesperostipa comata (C3) grass species at the Prairie Heating and CO 2 Enrichment (PHACE) experiment at Wyoming, USA. Roots of B. gracilis exposed to elevated CO 2 and warming had higher abundances of suberin and lignin than those exposed to ambient climate treatments. In addition to changes in their abundance, roots exposed to warming and elevated CO 2 had higher ω-hydroxy acids compared to plants grown under ambient conditions. The suberin content and composition in roots of H. comata was less responsive to climate treatments. In H. comata, α,ω-dioic acids increased with the main effect of elevated CO 2, whereas the total quantity of suberin exhibited an increasing trend with the main effect of warming and elevated CO 2. The increase in suberin content and altered composition could lower root decomposition rates with implications for root-derived soil carbon under global change. Our study also suggests that the climate change induced alterations in species composition will further mediate potential suberin contributions to soil carbon pools.« less

Warming and elevated CO 2 alter the suberin chemistry in roots of photosynthetically divergent grass species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suseela, Vidya; Tharayil, Nishanth; Pendall, Elise

A majority of soil carbon (C) is either directly or indirectly derived from fine roots, yet roots remain the least understood component of the terrestrial carbon cycle. The decomposability of fine roots and their potential to contribute to soil C is partly regulated by their tissue chemical composition. Roots rely heavily on heteropolymers such as suberins, lignins and tannins to adapt to various environmental pressures and to maximize their resource uptake functions. Since the chemical construction of roots is partly shaped by their immediate biotic/abiotic soil environments, global changes that perturb soil resource availability and plant growth could potentially altermore » root chemistry, and hence the decomposability of roots. However, the effect of global change on the quantity and composition of root heteropolymers are seldom investigated. We examined the effects of elevated CO 2 and warming on the quantity and composition of suberin in roots of Bouteloua gracilis (C4) and Hesperostipa comata (C3) grass species at the Prairie Heating and CO 2 Enrichment (PHACE) experiment at Wyoming, USA. Roots of B. gracilis exposed to elevated CO 2 and warming had higher abundances of suberin and lignin than those exposed to ambient climate treatments. In addition to changes in their abundance, roots exposed to warming and elevated CO 2 had higher ω-hydroxy acids compared to plants grown under ambient conditions. The suberin content and composition in roots of H. comata was less responsive to climate treatments. In H. comata, α,ω-dioic acids increased with the main effect of elevated CO 2, whereas the total quantity of suberin exhibited an increasing trend with the main effect of warming and elevated CO 2. The increase in suberin content and altered composition could lower root decomposition rates with implications for root-derived soil carbon under global change. Our study also suggests that the climate change induced alterations in species composition will further mediate potential suberin contributions to soil carbon pools.« less

It All Began with Raiffeisen: Co-operatives as Instruments of Self-Help and Development.

ERIC Educational Resources Information Center

Nover, Kurt

1986-01-01

The rural and manufacturing co-operatives and credit co-operatives in the Federal Republic of Germany have succeeded in continuously expanding and consolidating their position within the framework of the country's market economy. As the biggest organizations of medium-size enterprises, the co-operatives have adapted to the new circumstances…

Carbon Monoxide Fumigation Improved the Quality, Nutrients, and Antioxidant Activities of Postharvest Peach

PubMed Central

Li, Ying; Pei, Fei

2014-01-01

Peaches (Prunus persica cv. Yanhong) were fumigated with carbon monoxide (CO) at 0, 0.5, 5, 10, and 20 μmol/L for 2 hours. The result showed that low concentration CO (0.5–10 μmol/L) might delay the decrease of firmness and titrable acid content, restrain the increase of decay incidence, and postpone the variation of soluble solids content, but treating peaches with high concentration CO (20 μmol/L) demonstrated adverse effects. Further research exhibited that exogenous CO could induce the phenylalnine ammonialyase activity, maintain nutrient contents such as Vitamin C, total flavonoid, and polyphenol, and enhance antioxidant activity according to reducing power and 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl radical scavenging activity. Treating peaches with appropriate concentration CO was beneficial to the quality, nutrients, and antioxidant activity of postharvest peaches during storage time. Therefore, CO fumigation might probably become a novel method to preserve postharvest peach and other fruits in the future. PMID:26904651

Effects of co-inoculation with arbuscular mycorrhizal fungi and rhizobia on soybean growth as related to root architecture and availability of N and P.

PubMed

Wang, Xiurong; Pan, Qiang; Chen, Fengxian; Yan, Xiaolong; Liao, Hong

2011-04-01

Soybean plants can form tripartite symbiotic associations with rhizobia and arbuscular mycorrhizal (AM) fungi, but little is known about effects of co-inoculation with rhizobia and AM fungi on plant growth, or their relationships to root architecture as well as nitrogen (N) and phosphorus (P) availability. In the present study, two soybean genotypes contrasting in root architecture were grown in a field experiment to evaluate relationships among soybean root architecture, AMF colonization, and nodulation under natural conditions. Additionally, a soil pot experiment in greenhouse was conducted to investigate the effects of co-inoculation with rhizobia and AM fungi on soybean growth, and uptake of N and P. Our results indicated that there was a complementary relationship between root architecture and AMF colonization in the field. The deep root soybean genotype had greater AMF colonization at low P, but better nodulation with high P supply than the shallow root genotype. A synergistic relationship dependent on N and P status exists between rhizobia and AM fungi on soybean growth. Co-inoculation with rhizobia and AM fungi significantly increased soybean growth under low P and/or low N conditions as indicated by increased shoot dry weight, along with plant N and P content. There were no significant effects of inoculation under adequate N and P conditions. Furthermore, the effects of co-inoculation were related to root architecture. The deep root genotype, HN112, benefited more from co-inoculation than the shallow root genotype, HN89. Our results elucidate new insights into the relationship between rhizobia, AM fungi, and plant growth under limitation of multiple nutrients, and thereby provides a theoretical basis for application of co-inoculation in field-grown soybean.

Data processing of Martian topographic information obtained from ground-based radar and spectroscopy and from Mariners 6 and 7. Martian topography elevations: Data processing

NASA Technical Reports Server (NTRS)

Anderson, K. A.

1974-01-01

Papers are presented which were published as a result of a project involving the preparation of a topographical elevation contour map of Mars from all data sources available through 1969, as well as the observation of Mars by spectroscopic methods in 1971 to provide additional pressure data for topographic information. Topics of the papers include: the analysis of large-scale Martian topography variations - data preparation from earth based radar, earth based CO2 spectroscopy, and Mariners 6 and 7 CO2 spectroscopy; the analysis of water content in observed Martian white clouds; and Martian, lunar, and terrestrial crusts - a three-dimensional exercise in comparative geophysics.

Double, Double Toil and Trouble: The Melt Inclusion Bubble

NASA Astrophysics Data System (ADS)

Rasmussen, D. J.; Plank, T. A.

2017-12-01

Melt inclusions provide a powerful means for probing the depth of magmatic processes and volatile budgets of magmas. Both objectives require that the inclusions accurately record the volatile content of the entrapped melt. However, post-entrapment cooling and diffusive loss of water lead to a decrease in internal pressure, resulting in volatile exsolution (importantly CO2) and vapor bubble growth in inclusions. Several methods have been developed recently that attempt to reconstruct the entrapped CO2 contents, but the methods yield inconsistent results. Here we report on new homogenization experiments and attempt to reconcile inconsistencies in CO2 reconstruction methods. Experiments were conducted on olivine-hosted melt inclusions from Seguam volcano using a piston cylinder apparatus at 500 MPa, 1150-1170 °C, hydrous conditions, and a run duration of 1-2 hours. FTIR analyses of the homogenized inclusions show some diffusive water gain (≤1 wt% excess) relative to unheated inclusions (most 4 wt%). Inclusions from this same sample were previously reconstructed using Raman addition (RA; Moore et al., 2015), and we have constituted the CO2 with two different computational approaches: the ideal gas law (IGL; Shaw et al., 2010) and a bubble growth model (BG; Riker, 2005). CO2 and S contents of heated inclusions are correlated, defining a S-CO2 degassing path. Relative to this empirical degassing path, IGL results are offset to higher CO2 (100s-1000s of ppm) or lower S (100s of ppm), while RA and BG results overlap and are offset to lower CO2 (≤100s of ppm) or higher S (≤100s of ppm). Because S contents of heated and unheated inclusions have similar ranges, we attribute the discrepancy to CO2. High values of CO2 from the IGL correction may be because CO2 diffusion cannot keep pace with bubble growth during rapid cooling upon eruption. Mass balance calculations indicate that a minute amount of carbonate, which could escape detection by Raman, would affect CO2 content, providing an explanation for low values of CO2 determined by RA. The discrepancy in the BG results might relate to diffusive loss of H+ and uncertainties (e.g., temperature) involved with the calculation. Thus, homogenization via heating has advantages over other techniques in constituting the CO2 of inclusions, and may lead to a more accurate computational method.

Magnetic properties of CeFe11-xCoxTi with ThMn12 structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, C; Pinkerton, FE; Herbst, JF

2014-05-07

A series of novel alloys CeFe11-xCoxTi (0 <= x <= 11) with ThMn12 structure has been successfully prepared by melt-spinning. The Curie temperature T-c increases with Co content x, reaching a maximum of 689 degrees C at x = 9 and declining to 664 degrees C at complete Co filling (x = 11). The room temperature saturation magnetization 4 pi M-s and magnetocrystalline anisotropy H-a have been estimated by fitting the first quadrant demagnetization curve with the Stoner-Wohlfarth model. 4 pi M-s first increases with increasing Co up to x = 3, then decrease. H-a has a complex dependence onmore » Co content, which is indicative of a change in the easy magnetization direction from axis to plane and back as the Co content increases. (C) 2014 AIP Publishing LLC.« less

Effect of W Contents on Martensitic Transformation and Shape Memory Effect in Co-Al-W Alloys

NASA Astrophysics Data System (ADS)

Yang, X.; Qian, B. N.; Peng, H. B.; Wu, B. J.; Wen, Y. H.

2018-04-01

To clarify the effect of W contents on the shape memory effect (SME) in the Co-Al alloys and its influencing mechanism, the SME, martensitic transformation, and deformation behavior were studied in the Co-7Al-xW ( x = 0, 4, 6, 9 wt pct) alloys. The results showed that the additions of W all deteriorated the SME in Co-7Al alloy when deformed at room temperature. However, when deformed in liquid nitrogen, the SME in Co-7Al alloy could be remarkably improved from 43 to 78 pct after the addition of 4 pct W, above which the SME decreased rapidly with the increase of W content although the yield strength of the parent phase rose due to the solution strengthening of W. The deterioration in SME induced by the excessive addition of W could be ascribed to its resulting significant drop of the start temperature of martensitic transformation.

Free radical scavenging of grape pomace extracts from Cabernet sauvingnon (Vitis vinifera).

PubMed

de Campos, Luanda M A S; Leimann, Fernanda V; Pedrosa, Rozangela Curi; Ferreira, Sandra R S

2008-11-01

Pressed grape pomace obtained from the wine production of Cabernet sauvignon (Vitis vinifera) vintage was dried until 9.8% moisture content, ground and submitted to extraction of soluble components from different extraction techniques. Low pressure extractions were performed with ethanol maceration followed by fractionation with n-hexane, dichloromethane, butanol and ethyl acetate. These solvents were furthermore applied for soxhlet extraction. Supercritical fluid extraction (SFE) was also performed to obtain grape pomace extracts by using pure CO2 and CO2 with ethanol as co-solvent in concentrations of 10, 15 and 20%w/w. The operating condition used in high pressure extractions was 150bar and 40 degrees C. The antioxidant activity of the grape pomace extracts was determined considering the free radical scavenging assay using 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and was correlated with the total phenol content determined according to the Folin-Ciocalteu method. The results obtained in DPPH tests indicate the highest antioxidant activity of 96.6+/-0.3%AA, with an IC50 value of 13+/-1, for the extracts obtained with ethyl acetate in solid-liquid extraction. The highest yield values were achieved in soxhlet extraction with ethanol (13.2%w/w) and with butanol (12.2%w/w), and also by SFE with 15% ethanol (9.2%w/w). The lipophilic composition of grape pomace extracts was evaluated by gas chromatography-mass spectrometry with the identification of components like linoleic acid and ethyl linoleate, with important therapeutic activities.

49 CFR 1546.103 - Form, content, and availability of security program.

Code of Federal Regulations, 2010 CFR

2010-10-01

... security program is acceptable only if TSA finds that the security program provides a level of protection similar to the level of protection provided by U.S. aircraft operators serving the same airports. Foreign... the same airport, if TSA determines that such procedures are necessary to provide a similar level of...

Syngas Production from Pyrolysis of Nine Composts Obtained from Nonhybrid and Hybrid Perennial Grasses

PubMed Central

Hlavsová, Adéla; Raclavská, Helena; Juchelková, Dagmar; Škrobánková, Hana; Frydrych, Jan

2014-01-01

A pyrolysis of compost for the production of syngas with an explicit H2/CO = 2 or H2/CO = 3 was investigated in this study. The composts were obtained from nonhybrid (perennial) grasses (NHG) and hybrid (perennial) grasses (HG). Discrepancies in H2 evolution profiles were found between NHG and HG composts. In addition, positive correlations for NHG composts were obtained between (i) H2 yield and lignin content, (ii) H2 yield and potassium content, and (iii) CO yield and cellulose content. All composts resulted in H2/CO = 2 and five of the nine composts resulted in H2/CO = 3. Exceptionally large higher heating values (HHVs) of pyrolysis gas, very close to HHVs of feedstock, were obtained for composts made from mountain brome (MB, 16.23 MJ/kg), hybrid Becva (FB, 16.45 MJ/kg), and tall fescue (TF, 17.43 MJ/kg). The MB and FB composts resulted in the highest syngas formation with H2/CO = 2, whereas TF compost resulted in the highest syngas formation with H2/CO = 3. PMID:25101320

Impact of Co-Site Interference on L/C-Band Spectrum for UAS Control and Non-Payload Communications

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Bishop, William D.; Hoder, Douglas J.; Shalkhauser, Kurt A.; Wilson, Jeffrey D.

2015-01-01

In order to provide for the safe integration of unmanned aircraft systems into the National Airspace System, the control and non-payload communications (CNPC) link connecting the ground-based pilot with the unmanned aircraft must be highly reliable. A specific requirement is that it must operate using aviation safety radiofrequency spectrum. The 2012 World Radiocommunication Conference (WRC-12) provided a potentially suitable allocation for LOS CNPC spectrum in C-Band at 5030-5091 MHz band which, when combined with a previous allocation in L-Band (960-1164 MHz) may satisfy the LOS spectrum requirement and provide for high reliability through dual-band redundancy. However, the LBand spectrum hosts a number of aeronautical navigation systems which require high-power transmitters on-board the aircraft. These high-power transmitters co-located with sensitive CNPC receivers operating in the same frequency band have the potential to create co-site interference, reducing the performance of the CNPC receivers and ultimately reducing the usability of the L-Band for CNPC. This paper examines the potential for co-site interference, as highlighted in recent flight tests, and discusses the impact on the UAS CNPC spectrum availability and requirements for further testing and analysis.

The NASA Micro-Pulse Lidar Network (MPLNET): Co-location of Lidars with AERONET

NASA Technical Reports Server (NTRS)

Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Holben, Brent; Tsay, Si-Chee

2004-01-01

We present the formation of a global-ground based eye-safe lidar network, the NASA Micro-Pulse Lidar Network (MPLNET). The aim of MPLNET is to acquire long-term observations of aerosol and cloud vertical profiles at unique geographic sites within the NASA Aerosol Robotic Network (AERONET). Network growth follows a federated approach, pioneered by AERONET, wherein independent research groups may join MPLNET with their own instrument and site. MPLNET utilizes standard instrumentation and data processing algorithms for efficient network operations and direct comparison of data between each site. The micro-pulse lidar is eye-safe, compact, and commercially available, and most easily allows growth of the network without sacrificing standardized instrumentation gods. Red-time data products (next-day) are available, and include Level 1 daily lidar signal images from the surface to -2Okm, and Level 1.5 aerosol extinction provides at times co-incident with AERONET observations. Testing of our quality assured aerosol extinction products, Level 2, is near completion and data will soon be available. Level 3 products, continuous daylight aerosol extinction profiles, are under development and testing has begun. An overview of h4PL" will be presented. Successful methods of merging standardized lidar operations with AERONET will also be discussed, with the first 4 years of MPLNET results serving as an example.

Ethanol and air quality: influence of fuel ethanol content on emissions and fuel economy of flexible fuel vehicles.

PubMed

Hubbard, Carolyn P; Anderson, James E; Wallington, Timothy J

2014-01-01

Engine-out and tailpipe emissions of NOx, CO, nonmethane hydrocarbons (NMHC), nonmethane organic gases (NMOG), total hydrocarbons (THC), methane, ethene, acetaldehyde, formaldehyde, ethanol, N2O, and NH3 from a 2006 model year Mercury Grand Marquis flexible fuel vehicle (FFV) operating on E0, E10, E20, E30, E40, E55, and E80 on a chassis dynamometer are reported. With increasing ethanol content in the fuel, the tailpipe emissions of ethanol, acetaldehyde, formaldehyde, methane, and ammonia increased; NOx and NMHC decreased; while CO, ethene, and N2O emissions were not discernibly affected. NMOG and THC emissions displayed a pronounced minimum with midlevel (E20-E40) ethanol blends; 25-35% lower than for E0 or E80. Emissions of NOx decreased by approximately 50% as the ethanol content increased from E0 to E30-E40, with no further decrease seen with E55 or E80. We demonstrate that emission trends from FFVs are explained by fuel chemistry and engine calibration effects. Fuel chemistry effects are fundamental in nature; the same trend of increased ethanol, acetaldehyde, formaldehyde, and CH4 emissions and decreased NMHC and benzene emissions are expected for all FFVs. Engine calibration effects are manufacturer and model specific; emission trends for NOx, THC, and NMOG will not be the same for all FFVs. Implications for air quality are discussed.

Lipid content and fatty acid composition of Porosira glacialis and Attheya longicornis in response to carbon dioxide (CO2) aeration.

PubMed

Artamonova, E Y; Vasskog, T; Eilertsen, H C

2017-01-01

In the current study two novel psychrophilic diatoms Porosira glacialis and Attheya longicornis were tested for suitability to CO2 mitigation coupled with production of the physiologically requisite omega- 3 fatty acids. This study is in line with the worldwide conducted research aimed at applying biorefinery concept to heavy polluting industries. Since the production of algal high value compounds, i.e. essential fatty acids, relies on utilization of residual CO2 emissions coming from industry, the costs of such production maybe substantially reduced. Besides, the ecological benefits of the biorefinery concept being implemented are obvious, since CO2 is one of the major greenhouse gases. The current research has shown that one of the tested microalgal species, the diatom P. glacialis showed good tolerance to high (20-25%) levels of CO2 and maintained growth rates comparable to controls. The total lipid content in the CO2 aerated culture increased from 8.91 to 10.57% in cell dry mass. Additionally, the content of docosahexaenoic acid (DHA) increased from 3.90 to 5.75%, while the concentration of eicosapentaenoic acid (EPA) decreased from 26.59 to 23.66%. In contrast, A. longicornis did not demonstrate any significant increase in total lipid content. Besides, its growth was hampered by high levels of CO2 aeration.

Study of the spray to globular transition in gas metal arc welding: a spectroscopic investigation

NASA Astrophysics Data System (ADS)

Valensi, F.; Pellerin, S.; Castillon, Q.; Boutaghane, A.; Dzierzega, K.; Zielinska, S.; Pellerin, N.; Briand, F.

2013-06-01

The gas metal arc welding (GMAW) process is strongly influenced by the composition of the shielding gas. In particular, addition of CO2 increases the threshold current for the transition from unstable globular to more stable spray transfer mode. We report on the diagnostics—using optical emission spectroscopy—of a GMAW plasma in pure argon and in mixtures of argon, CO2 and N2 while operated in spray and globular transfer modes. The spatially resolved plasma parameters are obtained by applying the Abel transformation to laterally integrated emission data. The Stark widths of some iron lines are used to determine both electron density and temperature, and line intensities yield relative contents of neutral and ionized iron to argon. Our experimental results indicate a temperature drop on the arc axis in the case of spray arc transfer. This drop reduces with addition of N2 and disappears in globular transfer mode when CO2 is added. Despite the temperature increase, the electron density decreases with CO2 concentration. The highest concentration of iron is observed in the plasma column upper part (close to the anode) and for GMAW with CO2. Our results are compared with recently published works where the effect of non-homogeneous metal vapour concentration has been taken into account.

Comparative study of the quality characteristics of defatted soy flour treated by supercritical carbon dioxide and organic solvent.

PubMed

Kang, Sung-Won; Rahman, M Shafiur; Kim, Ah-Na; Lee, Kyo-Yeon; Park, Chan-Yang; Kerr, William L; Choi, Sung-Gil

2017-07-01

Defatted soy flour is a potential source of food protein, amino acids, ash and isoflavones. The supercritical carbon dioxide (SC-CO 2 ) and a traditional organic solvent extraction methods were used to remove fat from soy flour, and the quality characteristics of a control soy flour (CSF), defatted soy flour by SC-CO 2 (DSFSC-CO 2 ) and defatted soy flour by an organic solvent (DSF-OS) were compared. The SC-CO 2 process was carried out at a constant temperature of 45 °C, and a pressure of 40 MPa for 3 h with a CO 2 flow rate of 30 g/min. The DSFSC-CO 2 had significantly higher protein, ash, and amino acids content than CSF and DSF-OS. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis demonstrated that CSF and DSFSC-CO 2 had protein bands of similar intensity and area that indicated no denaturation of protein, whereas DSF-OS showed diffuse bands or no bands due to protein denaturation. In addition to higher nutritional value and protein contents, DSFSC-CO 2 showed superior functional properties in terms of total soluble solids content, water and oil absorption, emulsifying and foaming capacity. The SC-CO 2 method offers a nutritionally and environmentally friendly alternative extraction processing approach for the removal of oil from high-protein food sources. It has a great potential for producing high-protein fat-free, and low-calorie content diet than the traditional organic solvent extraction method.

Effect of CO2 levels on nutrient content of lettuce and radish.

PubMed

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

1996-01-01

Atmospheric carbon-dioxide enrichment is known to affect the yield of lettuce and radish grown in controlled environments, but little is known about CO2 enrichment effects on the chemical composition of lettuce and radish. These crops are useful model systems for a Controlled Ecological Life-Support System (CELSS), largely because of their relatively short production cycles. Lettuce (Lactuca sativa L.) cultivar 'Waldmann's Green' and radish (Raphanus sativus L.) cultivar 'Giant White Globe' were grown both in the field and in controlled environments, where hydroponic nutrient solution, light, and temperature were regulated, and where CO2 levels were controlled at 400, 1000, 5000, or 10,000 ppm. Plants were harvested at maturity, dried, and analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate N, free sugars, starch, total dietary fiber, and minerals. Total N, protein N, nonprotein N (NPN), and nitrate N generally increased for radish roots and lettuce leaves when grown under growth chamber conditions compared to field conditions. The nitrate-N level of lettuce leaves, as a percentage of total NPN, decreased with increasing levels of CO2 enrichment. The ash content of radish roots and of radish and lettuce leaves decreased with increasing levels of CO2 enrichment. The levels of certain minerals differed between field- and chamber-grown materials, including changes in the calcium (Ca) and phosphorus (P) contents of radish and lettuce leaves, resulting in reduced Ca/P ratio for chamber-grown materials. The free-sugar contents were similar between the field and chamber-grown lettuce leaves, but total dietary fiber content was much higher in the field-grown plant material. The starch content of growth-chamber lettuce increased with CO2 level.

Effect of CO_2 levels on nutrient content of lettuce and radish

NASA Astrophysics Data System (ADS)

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

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

Effect of CO2 levels on nutrient content of lettuce and radish

NASA Technical Reports Server (NTRS)

McKeehen, J. D.; Smart, D. J.; Mackowiak, C. L.; Wheeler, R. M.; Nielsen, S. S.; Mitchell, C. A. (Principal Investigator)

1996-01-01

Atmospheric carbon-dioxide enrichment is known to affect the yield of lettuce and radish grown in controlled environments, but little is known about CO2 enrichment effects on the chemical composition of lettuce and radish. These crops are useful model systems for a Controlled Ecological Life-Support System (CELSS), largely because of their relatively short production cycles. Lettuce (Lactuca sativa L.) cultivar 'Waldmann's Green' and radish (Raphanus sativus L.) cultivar 'Giant White Globe' were grown both in the field and in controlled environments, where hydroponic nutrient solution, light, and temperature were regulated, and where CO2 levels were controlled at 400, 1000, 5000, or 10,000 ppm. Plants were harvested at maturity, dried, and analyzed for proximate composition (protein, fat, ash, and carbohydrate), total nitrogen (N), nitrate N, free sugars, starch, total dietary fiber, and minerals. Total N, protein N, nonprotein N (NPN), and nitrate N generally increased for radish roots and lettuce leaves when grown under growth chamber conditions compared to field conditions. The nitrate-N level of lettuce leaves, as a percentage of total NPN, decreased with increasing levels of CO2 enrichment. The ash content of radish roots and of radish and lettuce leaves decreased with increasing levels of CO2 enrichment. The levels of certain minerals differed between field- and chamber-grown materials, including changes in the calcium (Ca) and phosphorus (P) contents of radish and lettuce leaves, resulting in reduced Ca/P ratio for chamber-grown materials. The free-sugar contents were similar between the field and chamber-grown lettuce leaves, but total dietary fiber content was much higher in the field-grown plant material. The starch content of growth-chamber lettuce increased with CO2 level.

Low-Energy Solvents For Carbon Dioxide Capture Enabled By A Combination Of Enzymes And Vacuum Regeneration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salmon, Sonja; House, Alan; Liu, Kun

An integrated bench-scale system combining the attributes of the bio-renewable enzyme carbonic anhydrase (CA) with low-enthalpy CO2 absorption solvents and vacuum regeneration was designed, built and operated for 500 hours using simulated flue gas. The objective was to develop a CO2 capture process with improved efficiency and sustainability when compared to NETL Case 10 monoethanolamine (MEA) scrubbing technology. The use of CA accelerates inter-conversion between dissolved CO2 and bicarbonate ion to enhance CO2 absorption, and the use of low enthalpy CO2 absorption solvents makes it possible to regenerate the solvent at lower temperatures relative to the reference MEA-based solvent. Themore » vacuum regeneration-based integrated bench-scale system operated successfully for an accumulated 500 hours using aqueous 23.5 wt% K2CO3-based solvent containing 2.5 g/L enzyme to deliver an average 84% CO2 capture when operated with a 20% enzyme replenishment rate per ~7 hour steady-state run period. The total inlet gas flow was 30 standard liters per minute with 15% CO2 and 85% N2. The absorber temperature was 40°C and the stripper operated under 35 kPa pressure with an approximate 77°C stripper bottom temperature. Tests with a 30°C absorber temperature delivered >90% capture. On- and off-line operational measurements provided a full process data set, with recirculating enzyme, that allowed for enzyme replenishment and absorption/desorption kinetic parameter calculations. Dissolved enzyme replenishment and conventional process controls were demonstrated as straightforward approaches to maintain system performance. Preliminary evaluation of a novel flow-through ultrasonically enhanced regeneration system was also conducted, yet resulted in CO2 release within the range of temperature-dependent release, and further work would be needed to validate the benefits of ultrasonic enhanced stripping. A full technology assessment was completed in which four techno-economic cases for enzyme-enhanced aqueous K2CO3 solvent with vacuum stripping were considered and a corresponding set of sensitivity studies were developed. The cases were evaluated using bench-scale and laboratory-based observations, AspenPlus® process simulation and modeling, AspenTech’s CCE® Parametric Software, current vendor quotations, and project partners’ know-how of unit operations. Overall, the DOE target of 90% CO2 capture could be met using the benign enzyme-enhanced aqueous K2CO3-based alternative to NETL Case 10. The model-predicted plant COE performance, scaled to 550 MWe net output, was 9% higher than NETL Case 10 for an enzyme-activated case with minimized technical risk and highest confidence in physical system performance utilizing commercially available equipment. A COE improvement of 2.8% versus NETL Case 10 was predicted when favorable features of improved enzyme longevity and additional power output from a very low pressure (VLP) turbine were combined, wherein corresponding high capital and operational costs limited the level of COE benefit. The environmental, health and safety (EH&S) profile of the system was found to be favorable and was compliant with the Federal EH&S legislation reviewed. Further work on a larger scale test unit is recommended to reduce the level of uncertainty inherent in extrapolating findings from a bench-scale unit to a full scale PCC plant, and to further investigate several identified opportunities for improvement. Production feasibility and suitability of carbonic anhydrases for scale-up testing was confirmed both through the current project and through parallel efforts.« less

Plasma Methane Pyrolysis for Spacecraft Oxygen Loop Closure

NASA Technical Reports Server (NTRS)

Greenwood, Z. W.

2018-01-01

Life support is a critical function of any crewed space vehicle or habitat. Human life support systems on the International Space Station (ISS) include a number of atmosphere revitalization (AR) technologies to provide breathable air and a comfortable living environment to the crew. The Trace Contaminant Control System removes harmful volatile organic compounds and other trace contaminants from the circulating air. The Carbon Dioxide Removal Assembly (CDRA) removes metabolic carbon dioxide (CO2) and returns air to the cabin. Humidity is kept at comfortable levels by a number of condensing heat exchangers. The Oxygen Generation Assembly (OGA) electrolyzes water to produce oxygen for the crew and hydrogen (H2) as a byproduct. A Sabatier reaction-based CO2 Reduction Assembly (CRA) was launched to the ISS in 2009 and became fully operational in June 2011.The CRA interfaces with both the OGA and CDRA. Carbon dioxide from the CDRA is compressed and stored in tanks until hydrogen is available from OGA water electrolysis. When the OGA is operational and there is CO2 available, the CRA is activated and produces methane and water via the Sabatier reaction shown in Equation 1... One approach to achieve these higher recovery rates builds upon the ISS AR architecture and includes adding a methane post-processor to recover H2 from CRA methane. NASA has been developing the Plasma Pyrolysis Assembly (PPA) to fill the role of a methane post-processor.

The effects of rainfall partitioning and evapotranspiration on the temporal and spatial variation of soil water content in a Mediterranean agroforestry system

NASA Astrophysics Data System (ADS)

Biel, C.; Molina, A.; Aranda, X.; Llorens, P.; Savé, R.

2012-04-01

Tree plantation for wood production has been proposed to mitigate CO2-related climate change. Although these agroforestry systems can contribute to maintain the agriculture in some areas placed between rainfed crops and secondary forests, water scarcity in Mediterranean climate could restrict its growth, and their presence will affect the water balance. Tree plantations management (species, plant density, irrigation, etc), hence, can be used to affect the water balance, resulting in water availability improvement and buffering of the water cycle. Soil water content and meteorological data are widely used in agroforestry systems as indicators of vegetation water use, and consequently to define water management. However, the available information of ecohydrological processes in this kind of ecosystem is scarce. The present work studies how the temporal and spatial variation of soil water content is affected by transpiration and interception loss fluxes in a Mediterranean rainfed plantation of cherry tree (Prunus avium) located in Caldes de Montbui (Northeast of Spain). From May till December 2011, rainfall partitioning, canopy transpiration, soil water content and meteorological parameters were continuously recorded. Rainfall partitioning was measured in 6 trees, with 6 automatic rain recorders for throughfall and 1 automatic rain recorder for stemflow per tree. Transpiration was monitored in 12 nearby trees by means of heat pulse sap flow sensors. Soil water content was also measured at three different depths under selected trees and at two depths between rows without tree cover influence. This work presents the relationships between rainfall partitioning, transpiration and soil water content evolution under the tree canopy. The effect of tree cover on the soil water content dynamics is also analyzed.

Growing Azolla to produce sustainable protein feed: the effect of differing species and CO2 concentrations on biomass productivity and chemical composition.

PubMed

Brouwer, Paul; Schluepmann, Henriette; Nierop, Klaas Gj; Elderson, Janneke; Bijl, Peter K; van der Meer, Ingrid; de Visser, Willem; Reichart, Gert-Jan; Smeekens, Sjef; van der Werf, Adrie

2018-03-24

Since available arable land is limited and nitrogen fertilizers pollute the environment, cropping systems ought to be developed that do not rely on them. Here we investigate the rapidly growing, N 2 -fixing Azolla/Nostoc symbiosis for its potential productivity and chemical composition to determine its potential as protein feed. In a small production system, cultures of Azolla pinnata and Azolla filiculoides were continuously harvested for over 100 days, yielding an average productivity of 90.0-97.2 kg dry weight (DW) ha -1  d -1 . Under ambient CO 2 levels, N 2 fixation by the fern's cyanobacterial symbionts accounted for all nitrogen in the biomass. Proteins made up 176-208 g kg -1 DW (4.9 × total nitrogen), depending on species and CO 2 treatment, and contained more essential amino acids than protein from soybean. Elevated atmospheric CO 2 concentrations (800 ppm) significantly boosted biomass production by 36-47%, without decreasing protein content. Choice of species and CO 2 concentrations further affected the biomass content of lipids (79-100 g kg -1 DW) and (poly)phenols (21-69 g kg -1 DW). By continuous harvesting, high protein yields can be obtained from Azolla cultures, without the need for nitrogen fertilization. High levels of (poly)phenols likely contribute to limitations in the inclusion rate of Azolla in animal diets and need further investigation. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2018 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of Propylene Carbonate Content in CsPF6-Containing Electrolytes on the Enhanced Performances of Graphite Electrode for Lithium-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Jianming; Yan, Pengfei; Cao, Ruiguo

2016-02-10

Cesium salt has been demonstrated as an efficient electrolyte additive in suppressing the lithium (Li) dendrite formation and directing the formation of an ultrathin and stable solid electrolyte interphase (SEI) even in propylene carbonate (PC)-ethylene carbonate (EC)-based electrolytes. Here, we further investigate the effect of PC content in the presence of CsPF6 additive (0.05 M) on the performances of graphite electrode in Li||graphite half cells and in graphite||LiNi0.80Co0.15Al0.05O2 (NCA) full cells. It is found that the performance of graphite electrode is also affected by PC content even though CsPF6 additive is present in the electrolytes. An optimal PC content ofmore » 20% by weight in the solvent mixtures is identified. The enhanced electrochemical performance of graphite electrode is attributed to the synergistic effects of the Cs+ additive and the PC solvent. The formation of a robust, ultrathin and compact SEI layer containing lithium-enriched species on the graphite electrode, directed by Cs+, effectively suppresses the PC co-intercalation and thus prevents the graphite exfoliation. This SEI layer is only permeable for de-solvated Li+ ions and allows fast Li+ ion transport through it, which therefore largely alleviates the Li dendrite formation on graphite electrode during lithiation even at high current densities. The presence of low-melting-point PC solvent also enables the sustainable operation of the graphite||NCA full cells under a wide spectrum of temperatures. The fundamental findings of this work shed light on the importance of manipulating/maintaining the electrode/electrolyte interphasial stability in a variety of energy storage devices.« less

Soil wind erosion in ecological olive trees in the Tabernas desert (southeastern Spain): a wind tunnel experiment

NASA Astrophysics Data System (ADS)

Asensio, Carlos; Lozano, Francisco Javier; Gallardo, Pedro; Giménez, Antonio

2016-08-01

Wind erosion is a key component of the soil degradation processes. The purpose of this study is to find out the influence of material loss from wind on soil properties for different soil types and changes in soil properties in olive groves when they are tilled. The study area is located in the north of the Tabernas Desert, in the province of Almería, southeastern Spain. It is one of the driest areas in Europe, with a semiarid thermo-Mediterranean type of climate. We used a new wind tunnel model over three different soil types (olive-cropped Calcisol, Cambisol and Luvisol) and studied micro-plot losses and deposits detected by an integrated laser scanner. We also studied the image processing possibilities for examining the particles attached to collector plates located at the end of the tunnel to determine their characteristics and whether they were applicable to the setup. Samples collected in the traps at the end of the tunnel were analyzed. We paid special attention to the influence of organic carbon, carbonate and clay contents because of their special impact on soil crusting and the wind-erodible fraction. A principal components analysis (PCA) was carried out to find any relations on generated dust properties and the intensity and behavior of those relationships. Component 1 separated data with high N and OC contents from samples high in fine silt, CO3= and available K content. Component 2 separated data with high coarse silt and clay contents from data with high fine sand content. Component 3 was an indicator of available P2O5 content. Analysis of variance (ANOVA) was carried out to analyze the effect of soil type and sampling height on different properties of trapped dust. Calculations based on tunnel data showed overestimation of erosion in soil types and calculation of the fraction of soil erodible by wind done by other authors for Spanish soils. As the highest loss was found in Cambisols, mainly due to the effect on soil crusting and the wind-erodible fraction aggregation of CaCO3, a Stevia rebaudiana cover crop was planted between the rows in this soil type and this favored retention of particles in vegetation.

Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency.

PubMed

Maglogiannis, Vasilis; Naudts, Dries; Shahid, Adnan; Giannoulis, Spilios; Laermans, Eric; Moerman, Ingrid

2017-08-31

On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner.

Cooperation Techniques between LTE in Unlicensed Spectrum and Wi-Fi towards Fair Spectral Efficiency

PubMed Central

Naudts, Dries; Shahid, Adnan; Giannoulis, Spilios; Laermans, Eric

2017-01-01

On the road towards 5G, a proliferation of Heterogeneous Networks (HetNets) is expected. Sensor networks are of great importance in this new wireless era, as they allow interaction with the environment. Additionally, the establishment of the Internet of Things (IoT) has incredibly increased the number of interconnected devices and consequently the already massive wirelessly transmitted traffic. The exponential growth of wireless traffic is pushing the wireless community to investigate solutions that maximally exploit the available spectrum. Recently, 3rd Generation Partnership Project (3GPP) announced standards that permit the operation of Long Term Evolution (LTE) in the unlicensed spectrum in addition to the exclusive use of the licensed spectrum owned by a mobile operator. Alternatively, leading wireless technology developers examine standalone LTE operation in the unlicensed spectrum without any involvement of a mobile operator. In this article, we present a classification of different techniques that can be applied on co-located LTE and Wi-Fi networks. Up to today, Wi-Fi is the most widely-used wireless technology in the unlicensed spectrum. A review of the current state of the art further reveals the lack of cooperation schemes among co-located networks that can lead to more optimal usage of the available spectrum. This article fills this gap in the literature by conceptually describing different classes of cooperation between LTE and Wi-Fi. For each class, we provide a detailed presentation of possible cooperation techniques that can provide spectral efficiency in a fair manner. PMID:28858243

Multi-channel Auto-dilution System for Remote Continuous Monitoring of High Soil-CO2 Fluxes

NASA Astrophysics Data System (ADS)

Barr, J. L.; Amonette, J. E.

2008-12-01

We describe a novel field instrument that takes input from up to 27 soil flux chambers and measures flux using the steady-state method. CO2 concentrations are determined with an infrared gas analyzer (IRGA, 0- 3000 ppmv range) with corrections for temperature, barometric pressure, and moisture content. The concentrations are monitored during data collection and, if they exceed the range of the IRGA, a stepped dilution program is automatically implemented that allows up to 50-fold dilution of the incoming gas stream with N2 supplied by boil-off from a large dewar. The upper concentration limit of the system with dilution is extended to at least 150,000 ppmv CO2. The data are stored on a datalogger having a cellular modem connection that allows remote control of the system as well as transmittal of data. The system is designed to operate for six weeks with no on-site maintenance required. Longer periods are possible with modifications to allow on-site generation of N2 from air. Example data from a recent CO2 test injection at the Zero- Emission Research and Technology (ZERT) field site in Bozeman, MT are presented.

Supersonic Plasma Spray Deposition of CoNiCrAlY Coatings on Ti-6Al-4V Alloy

NASA Astrophysics Data System (ADS)

Caliari, F. R.; Miranda, F. S.; Reis, D. A. P.; Essiptchouk, A. M.; Filho, G. P.

2017-06-01

Plasma spray is a versatile technology used for production of environmental and thermal barrier coatings, mainly in the aerospace, gas turbine, and automotive industries, with potential application in the renewable energy industry. New plasma spray technologies have been developed recently to produce high-quality coatings as an alternative to the costly low-pressure plasma-spray process. In this work, we studied the properties of as-sprayed CoNiCrAlY coatings deposited on Ti-6Al-4V substrate with smooth surface ( R a = 0.8 μm) by means of a plasma torch operating in supersonic regime at atmospheric pressure. The CoNiCrAlY coatings were evaluated in terms of their surface roughness, microstructure, instrumented indentation, and phase content. Static and dynamic depositions were investigated to examine their effect on coating characteristics. Results show that the substrate surface velocity has a major influence on the coating properties. The sprayed CoNiCrAlY coatings exhibit low roughness ( R a of 5.7 μm), low porosity (0.8%), excellent mechanical properties ( H it = 6.1 GPa, E it = 155 GPa), and elevated interface toughness (2.4 MPa m1/2).

Effect of different CO2 concentrations on biomass, pigment content, and lipid production of the marine diatom Thalassiosira pseudonana.

PubMed

Sabia, Alessandra; Clavero, Esther; Pancaldi, Simonetta; Salvadó Rovira, Joan

2018-02-01

The marine diatom Thalassiosira pseudonana grown under air (0.04% CO 2 ) and 1 and 5% CO 2 concentrations was evaluated to determine its potential for CO 2 mitigation coupled with biodiesel production. Results indicated that the diatom cultures grown at 1 and 5% CO 2 showed higher growth rates (1.14 and 1.29 div day -1 , respectively) and biomass productivities (44 and 48 mg AFDW L -1  day -1 ) than air grown cultures (with 1.13 div day -1 and 26 mg AFDW L -1  day -1 ). The increase of CO 2 resulted in higher cell volume and pigment content per cell of T. pseudonana. Interestingly, lipid content doubled when air was enriched with 1-5% CO 2 . Moreover, the analysis of the fatty acid composition of T. pseudonana revealed the predominance of monounsaturated acids (palmitoleic-16:1 and oleic-18:1) and a decrease of the saturated myristic acid-14:0 and polyunsaturated fatty acids under high CO 2 levels. These results suggested that T. pseudonana seems to be an ideal candidate for biodiesel production using flue gases.

The Effect of Surfactant Content over Cu-Ni Coatings Electroplated by the sc-CO2 Technique

PubMed Central

Chuang, Ho-Chiao; Sánchez, Jorge; Cheng, Hsiang-Yun

2017-01-01

Co-plating of Cu-Ni coatings by supercritical CO2 (sc-CO2) and conventional electroplating processes was studied in this work. 1,4-butynediol was chosen as the surfactant and the effects of adjusting the surfactant content were described. Although the sc-CO2 process displayed lower current efficiency, it effectively removed excess hydrogen that causes defects on the coating surface, refined grain size, reduced surface roughness, and increased electrochemical resistance. Surface roughness of coatings fabricated by the sc-CO2 process was reduced by an average of 10%, and a maximum of 55%, compared to conventional process at different fabrication parameters. Cu-Ni coatings produced by the sc-CO2 process displayed increased corrosion potential of ~0.05 V over Cu-Ni coatings produced by the conventional process, and 0.175 V over pure Cu coatings produced by the conventional process. For coatings ~10 µm thick, internal stress developed from the sc-CO2 process were ~20 MPa lower than conventional process. Finally, the preferred crystal orientation of the fabricated coatings remained in the (111) direction regardless of the process used or surfactant content. PMID:28772787

Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.).

PubMed

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.

W-Incorporated CoMo/{lambda}-Al{sub 2}O{sub 3} hydrosulfurization catalyst. II. Characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, D.K.; Lee, H.T.

1996-03-01

Series of W-incorporated CoMo/{gamma}-Al{sub 2}O{sub 3} catalysts were characterized with TPR, DRS, ESR, and XPS. Two series of catalysts with varying content of tungsten were prepared for characterization by changing the impregnation order of cobalt and tungsten to a base Mo/{gamma}-Al{sub 2}O{sub 3} catalyst. The activity promotion by relatively low content of tungsten arose from the roles of tungsten in changing the Mo-oxide coordination from tetrahedral to octahedral, facilitating the reduction of Mo-oxide species, and increasing the dispersion of MoS{sub 2}. By incorporation of tungsten at a content as much as 0.025 in W/(W + Mo) atomic ratio, the MoS{submore » 2} dispersion of CoMo/{gamma}-Al{sub 2}O{sub 3} catalyst was considered to be maximized without noticeable detriment to the active Co-Mo-O phase, resulting in the maximum activity promotion. The formation of the Co-Mo-O phases was more favored in the catalysts prepared by impregnating W onto CoMo/{gamma}-Al{sub 2}O{sub 3} than in those by impregnating W onto Mo/{gamma}-Al{sub 2}O{sub 3} before impregnation of Co. The effect of tungsten on the dispersion of active phase was not discriminated between the two series of catalysts. The activity decrease observed in the catalysts containing higher content of tungsten originated from the increase in the W-oxide coverage on the surface of Mo-oxides or Co-Mo-O phases, resulting in not only impeding the reduction or sulfidation of the oxidic precursor but facilitating the formation of less active Co-W-O at the sacrifice of more active Co-Mo-O phase. 40 refs., 11 figs., 1 tab.« less

Varying response of the concentration and content of soybean seed mineral elements, carbohydrates, organic acids, amino acids, protein, and oil to phosphorus starvation and CO2 enrichment

USDA-ARS?s Scientific Manuscript database

A detailed investigation of the concentration (g-1 seed weight) and content (g plant-1) of seed mineral elements and metabolic profile under phosphorus (P) starvation at ambient (aCO2) and elevated carbon dioxide (eCO2) in soybean is limited. Soybean plants were grown in a controlled environment at ...

The acyl-activating enzyme PhAAE13 is an alternative enzymatic source of precursors for anthocyanin biosynthesis in petunia flowers

PubMed Central

Chen, Guoju; Liu, Heping; Wei, Qian; Zhao, Huina

2017-01-01

Abstract Anthocyanins, a class of flavonoids, are responsible for the orange to blue coloration of flowers and act as visual attractors to aid pollination and seed dispersal. Malonyl-CoA is the precursor for the formation of flavonoids and anthocyanins. Previous studies have suggested that malonyl-CoA is formed almost exclusively by acetyl-CoA carboxylase, which catalyzes the ATP-dependent formation of malonyl-CoA from acetyl-CoA and bicarbonate. In the present study, the full-length cDNA of Petunia hybrida acyl-activating enzyme 13 (PhAAE13), a member of clade VII of the AAE superfamily that encodes malonyl-CoA synthetase, was isolated. The expression of PhAAE13 was highest in corollas and was down-regulated by ethylene. Virus-induced gene silencing of petunia PhAAE13 significantly reduced anthocyanin accumulation, fatty acid content, and cuticular wax components content, and increased malonic acid content in flowers. The silencing of PhAAE3 and PhAAE14, the other two genes in clade VII of the AAE superfamily, did not change the anthocyanin content in petunia flowers. This study provides strong evidence indicating that PhAAE13, among clade VII of the AAE superfamily, is specifically involved in anthocyanin biosynthesis in petunia flowers. PMID:28204578

An assessment of the risk of element contamination of urban and industrial areas using Taraxacum sect. Ruderalia as a bioindicator.

PubMed

Fröhlichová, Alena; Száková, Jiřina; Najmanová, Jana; Tlustoš, Pavel

2018-02-19

Central Bohemia (Czech Republic) has highly developed industry and a dense rail network. Here, we aimed to determine the content of risk elements in dandelion plants (Taraxacum sect. Ruderalia) growing near train stations, industrial enterprises, and in the city parks of 16 cities in the Central Bohemian region. The highest element contents in the soils were found in industrial areas affected by the historical mining and smelting activities; contemporary industry showed no substantial effect on the soil element contents. The median values of element contents (As, Be, Cd, Co, Cr, Cu, Ni, Pb, and Zn) at the railway station sites were the highest among the monitored sites, where the differences between park and station sites were significant for Be, Co, and Zn. Although the intensity of the traffic at the individual stations differed, we found that long-term regular traffic enhanced the element contents in the soils and, subsequently, in the plants. For Cd, Co, Cr, Cu, Pb, V, and Zn, the highest median element contents were found in plant roots, regardless of the sampling site. For Cd and Zn, the contents in leaves were higher than in the inflorescences, and the opposite pattern was recorded for Co and Cu. As and Be were distributed equally among the plant parts. Among the sampling sites, the As, Be, Cd, Zn, and Pb contents in the plant roots tended to have higher median values at the station sites, confirming the results of our soil analyses. We detected a fairly good correlation between soil and plant content for cadmium, regardless of the sampling site, soil element content, or analyzed part of the plant. Thus, we propose that dandelion is a suitable bioindicator of cadmium pollution of soil.

Effects of soil organic matter content on cadmium toxicity in Eisenia fetida: implications for the use of biomarkers and standard toxicity tests.

PubMed

Irizar, A; Rodríguez, M P; Izquierdo, A; Cancio, I; Marigómez, I; Soto, M

2015-01-01

Bioavailability is affected by soil physicochemical characteristics such as pH and organic matter (OM) content. In addition, OM constitutes the energy source of Eisenia fetida, a well established model species for soil toxicity assessment. The present work aimed at assessing the effects of changes in OM content on the toxicity of Cd in E. fetida through the measurement of neutral red uptake (NRU) and mortality, growth, and reproduction (Organisation for Economic Co-operation and Development [OECD] Nos. 207 and 222). Complementarily, metallothionein (MT) and catalase transcription levels were measured. To decrease variability inherent to natural soils, artificial soils (Organization for Economic Cooperation and Development 1984) with different OM content (6, 10, and 14%) and spiked with Cd solutions at increasing concentrations were used. Low OM in soil decreased soil ingestion and Cd bioaccumulation but also increased Cd toxicity causing lower NRU of coelomocytes, 100 % mortality, and stronger reproduction impairment, probably due to the lack of energy to maintain protection mechanisms (production of MT).Cd bioaccumulation did not reflect toxicity, and OM played a pivotal role in Cd toxicity. Thus, OM content should be taken into account when using E. fetida in in vivo exposures for soil health assessment.

A diesel fuel processor for fuel-cell-based auxiliary power unit applications

NASA Astrophysics Data System (ADS)

Samsun, Remzi Can; Krekel, Daniel; Pasel, Joachim; Prawitz, Matthias; Peters, Ralf; Stolten, Detlef

2017-07-01

Producing a hydrogen-rich gas from diesel fuel enables the efficient generation of electricity in a fuel-cell-based auxiliary power unit. In recent years, significant progress has been achieved in diesel reforming. One issue encountered is the stable operation of water-gas shift reactors with real reformates. A new fuel processor is developed using a commercial shift catalyst. The system is operated using optimized start-up and shut-down strategies. Experiments with diesel and kerosene fuels show slight performance drops in the shift reactor during continuous operation for 100 h. CO concentrations much lower than the target value are achieved during system operation in auxiliary power unit mode at partial loads of up to 60%. The regeneration leads to full recovery of the shift activity. Finally, a new operation strategy is developed whereby the gas hourly space velocity of the shift stages is re-designed. This strategy is validated using different diesel and kerosene fuels, showing a maximum CO concentration of 1.5% at the fuel processor outlet under extreme conditions, which can be tolerated by a high-temperature PEFC. The proposed operation strategy solves the issue of strong performance drop in the shift reactor and makes this technology available for reducing emissions in the transportation sector.

Local geometric and electronic structures and origin of magnetism in Co-doped BaTiO3 multiferroics

NASA Astrophysics Data System (ADS)

Phan, The-Long; Thang, P. D.; Ho, T. A.; Manh, T. V.; Thanh, Tran Dang; Lam, V. D.; Dang, N. T.; Yu, S. C.

2015-05-01

We have prepared polycrystalline samples BaTi1-xCoxO3 (x = 0-0.1) by solid-state reaction. X-ray diffraction and Raman-scattering studies reveal the phase separation in crystal structure as changing Co-doping content (x). The samples with x = 0-0.01 are single phase in a tetragonal structure. At higher doping contents (x > 0.01), there is the formation and development of a secondary hexagonal phase. Magnetization measurements at room temperature indicate a coexistence of paramagnetic and weak-ferromagnetic behaviors in BaTi1-xCoxO3 samples with x > 0, while pure BaTiO3 is diamagnetic. Both these properties increase with increasing x. Analyses of X-ray absorption spectra recorded from BaTi1-xCoxO3 for the Co and Ti K-edges indicate the presence of Co2+ and Co3+ ions. They locate in the Ti4+ site of the tetragonal and hexagonal BaTiO3 structures. Particularly, there is a shift of oxidation state from Co2+ to Co3+ when Co-doping content increases. We believe that the paramagnetic nature in BaTi1-xCoxO3 samples is due to isolated Co2+ and Co3+ centers. The addition of Co3+ ions enhances the paramagnetic behavior. Meanwhile, the origin of ferromagnetism is due to lattice defects, which is less influenced by the changes caused by the variation in concentration of Co2+ and Co3+ ions.

Influences of carbon content and coating carbon thickness on properties of amorphous CoSnO3@C composites as anode materials for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Fan, Fuqiang; Fang, Guoqing; Zhang, Ruixue; Xu, Yanhui; Zheng, Junwei; Li, Decheng

2014-08-01

A series of core-shell carbon coated amorphous CoSnO3 (CoSnO3@C) with different carbon content are synthesized. Effects of carbon content and coating carbon thickness on the physical and electrochemical performances of the samples were studied in detail. The samples were analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), galvanostatic charge-discharge and AC impedance spectroscopy, respectively. The results indicate that controlling the concentration of aqueous glucose solution influences the generation of in-situ carbon layer thickness. The optimal concentration of aqueous glucose solution, carbon content and carbon layer thickness are suggested as 0.25 M, 35.1% and 20 nm, respectively. CoSnO3@C composite prepared under the optimal conditions exhibits excellent cycling performance, whose reversible capacity could reach 491 mA h g-1 after 100 cycles.

Ambient-temperature co-oxidation catalysts

NASA Technical Reports Server (NTRS)

Upchurch, Billy T.; Schryer, David R.; Brown, Kenneth G.; Kielin, Erik J.

1991-01-01

Oxidation catalysts which operate at ambient temperature were developed for the recombination of carbon monoxide (CO) and oxygen (O2) dissociation products which are formed during carbon dioxide (CO2) laser operation. Recombination of these products to regenerate CO2 allows continuous operation of CO2 lasers in a closed cycle mode. Development of these catalyst materials provides enabling technology for the operation of such lasers from space platforms or in ground based facilities without constant gas consumption required for continuous open cycle operation. Such catalysts also have other applications in various areas outside the laser community for removal of CO from other closed environments such as indoor air and as an ambient temperature catalytic converter for control of auto emissions.

Two decades of regular observations of (CO{sub 2})-C-14 and (CO{sub 2})-C-13 content in atmospheric carbon dioxide in central Europe: Long-term changes of regional anthropogenic fossil CO{sub 2} emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuc, T.; Rozanski, K.; Zimnoch, M.

2007-07-01

Time series are presented of radiocarbon and C-13 contents in atmospheric carbon dioxide over eastern Europe (southern Poland), covering the periods 1983-1994 and 2000-2004. The carbon isotope composition was measured in biweekly composite samples of atmospheric CO{sub 2}, collected about 20 m above the local ground level. The data for 2 observational sites are presented: I) city of Krakow (50{sup o} 04'N, 19{sup o} 55'E; 220 m asl; for 1983-1994 and 2000-2004); and ii) Kasprowy Wierch, Tatra Mountains (49{sup o} 14'N, 19{sup o} 56'E; 1989 m asl; for 2000-2004). The latter site is considered a regional reference station, relatively freemore » of anthropogenic influences. During the period 1983-1994, observations in the Krakow area revealed a gradual decrease of C-14 content with a broad minimum around 1991 and a small increase by about 10 parts per thousand in the subsequent years. {delta}C-13 also changes with time, showing a decreasing trend from approximately -9.6 parts per thousand in 1983, with a slope of -0.02 parts per thousand/yr. The observed trends for both isotopes coincide well with a substantial reduction of coal consumption in Poland and partial replacement of coal by natural gas, especially in urban regions. After 2000, the {delta}C-13 slightly increases, reaching a mean value of -10 parts per thousand in 2004, while {delta}C-14 is below the reference level by similar to 3.5 parts per thousand. Observations at Kasprowy Wierch (regional reference station) also reflect a diminishing input of fossil carbon into the regional atmosphere. The fossil component in atmospheric CO{sub 2}, calculated with the aid of C-14 data available for the 2 study periods, shows a reduction of anthropogenic input by a factor of 2, which is confirmed by annual statistics of coal consumption.« less

Knockout Blow? The Army Air Force’s Operations Against Ploesti and Balikpapan

DTIC Science & Technology

2005-06-01

DEFENSE OF NEW ZEALAND ,” NEW ZEALAND ELECTRONIC TEXT CENTRE, N.P., ON LINE, INTERNET, 12 MAY 2005, AVAILABLE FROM HTTP://WWW.NZETC.ORG/TM/SCHOLARLY...COLLEGE PARK, COLLEGE PARK, MD. “DEFENSE OF NEW ZEALAND .” NEW ZEALAND ELECTRONIC TEXT CENTRE, N.P. ON LINE. INTERNET, 12 MAY 2005. AVAILABLE...1 Richard Overy, Why the Allies Won ( New York: W.W. Norton and Co., 1995), 228. 2 Overy, 228. 3 ARMY AIR FORCE EVALUATION BOARD

Reconstructing mantle volatile contents through the veil of degassing

NASA Astrophysics Data System (ADS)

Tucker, J.; Mukhopadhyay, S.; Gonnermann, H. M.

2014-12-01

The abundance of volatile elements in the mantle reveals critical information about the Earth's origin and evolution such as the chemical constituents that built the Earth and material exchange between the mantle and exosphere. However, due to magmatic degassing, volatile element abundances measured in basalts usually do not represent those in undegassed magmas and hence in the mantle source of the basalts. While estimates of average mantle concentrations of some volatile species can be obtained, such as from the 3He flux into the oceans, volatile element variability within the mantle remains poorly constrained. Here, we use CO2-He-Ne-Ar-Xe measurements in basalts and a new degassing model to reconstruct the initial volatile contents of 8 MORBs from the Mid-Atlantic Ridge and Southwest Indian Ridge that span a wide geochemical range from depleted to enriched MORBs. We first show that equilibrium degassing (e.g. Rayleigh degassing), cannot simultaneously fit the measured CO2-He-Ne-Ar-Xe compositions in MORBs and argue that kinetic fractionation between bubbles and melt lowers the dissolved ratios of light to heavy noble gas species in the melt from that expected at equilibrium. We present a degassing model (after Gonnermann and Mukhopadhyay, 2007) that explicitly accounts for diffusive fractionation between melt and bubbles. The model computes the degassed composition based on an initial volatile composition and a diffusive timescale. To reconstruct the undegassed volatile content of a sample, we find the initial composition and degassing timescale which minimize the misfit between predicted and measured degassed compositions. Initial 3He contents calculated for the 8 MORB samples vary by a factor of ~7. We observe a correlation between initial 3He and CO2 contents, indicating relatively constant CO2/3He ratios despite the geochemical diversity and variable gas content in the basalts. Importantly, the gas-rich popping rock from the North Atlantic, as well as the average mantle ratio computed from the ridge 3He flux and independently estimated CO2 content fall along the same correlation. This observation suggests that undegassed CO2 and noble gas concentrations can be reconstructed in individual samples through measurement of noble gases and CO2 in erupted basalts.

[Research on the spectral feature and identification of the surface vegetation stressed by stored CO2 underground leakage].

PubMed

Chen, Yun-Hao; Jiang, Jin-Bao; Steven, Michael D; Gong, A-Du; Li, Yi-Fan

2012-07-01

With the global climate warming, reducing greenhouse gas emissions becomes a focused problem for the world. The carbon capture and storage (CCS) techniques could mitigate CO2 into atmosphere, but there is a risk in case that the CO2 leaks from underground. The objective of this paper is to study the chlorophyll contents (SPAD value), relative water contents (RWC) and leaf spectra changing features of beetroot under CO2 leakage stress through field experiment. The result shows that the chlorophyll contents and RWC of beetroot under CO2 leakage stress become lower than the control beetroot', and the leaf reflectance increases in the 550 nm region and decreases in the 680nm region. A new vegetation index (R550/R680) was designed for identifying beetroot under CO2 leakage stress, and the result indicates that the vegetation index R550/R680 could identify the beetroots after CO2 leakage for 7 days. The index has strong sensitivity, stability and identification for monitoring the beetroots under CO2 stress. The result of this paper has very important meaning and application values for selecting spots of CCS project, monitoring and evaluating land-surface ecology under CO2 stress and monitoring the leakage spots by using remote sensing.

Content-based image retrieval on mobile devices

NASA Astrophysics Data System (ADS)

Ahmad, Iftikhar; Abdullah, Shafaq; Kiranyaz, Serkan; Gabbouj, Moncef

2005-03-01

Content-based image retrieval area possesses a tremendous potential for exploration and utilization equally for researchers and people in industry due to its promising results. Expeditious retrieval of desired images requires indexing of the content in large-scale databases along with extraction of low-level features based on the content of these images. With the recent advances in wireless communication technology and availability of multimedia capable phones it has become vital to enable query operation in image databases and retrieve results based on the image content. In this paper we present a content-based image retrieval system for mobile platforms, providing the capability of content-based query to any mobile device that supports Java platform. The system consists of light-weight client application running on a Java enabled device and a server containing a servlet running inside a Java enabled web server. The server responds to image query using efficient native code from selected image database. The client application, running on a mobile phone, is able to initiate a query request, which is handled by a servlet in the server for finding closest match to the queried image. The retrieved results are transmitted over mobile network and images are displayed on the mobile phone. We conclude that such system serves as a basis of content-based information retrieval on wireless devices and needs to cope up with factors such as constraints on hand-held devices and reduced network bandwidth available in mobile environments.

Improving the Management of Urban Research: City/University Co-Operation. OECD Urban Management Studies 5. Revised.

ERIC Educational Resources Information Center

Organisation for Economic Cooperation and Development, Paris (France).

The papers in this collection were presented at an international symposium on improving the management of urban research, particularly through city-university collaboration. An introductory framework paper summarizes the range of research services available to local government, the types of urban research activity, and the problems of urban…

Education in States and Nations: Indicators Comparing U.S. States with the OECD Countries in 1988.

ERIC Educational Resources Information Center

Salganik, Laura Hersh; And Others

This report is based on the first international education indicators produced by the Organization for Economic Co-operation and Development (OECD). The 16 indicators were chosen to take advantage of data available in "Education at a Glance," the most up-to-date set of international educational indicators. Indicators are grouped into…

Influence of Oxygen Content in Oriented LaCoO3-δ Thin Films: Probed by X-ray diffraction and Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Mishra, D. K.; Ahlawat, Anju; Sathe, V. G.

2011-07-01

Nonstoichiometric oriented thin films of LaCoO3-δ of equal thickness and varying oxygen content has been deposited on STO (001) substrate by pulsed laser deposition. X-ray diffraction results show that all films are single phase and c-axis oriented in the (001) direction with in plane tensile strain. In these films strain reduces with increasing oxygen content and Raman study also support this result. Low temperature Raman study shows no change in spin state of Co3+ in temperature range from 300 K to down to 80 K.

Oxygen permeation and stability of La 0.4Ca 0.6Fe 1-xCo xO 3-δ ( x = 0, 0.25, 0.5) membranes

NASA Astrophysics Data System (ADS)

Diethelm, S.; Van herle, J.; Middleton, P. H.; Favrat, D.

Three perovskite-type compounds of composition La 0.4Ca 0.6Fe 1- xCo xO 3- δ ( x=0, 0.25 and 0.5) were investigated for use as oxygen separation membranes for the partial oxidation (POX) of methane to syngas. Special attention was given to the question of their stability in real operating conditions. A permeation set-up was specially designed to measure oxygen fluxes through these materials when placed in a strong pO 2 gradient. It also facilitated testing the long-term stability of the specimen. Permeation measurements performed in an air/argon gradient between 800 and 1000 °C showed that the highest fluxes were obtained with the highest content of cobalt (La 0.4Ca 0.6Fe 0.5Co 0.5O 3- δ ≅ La 0.4Ca 0.6Fe 0.75Co 0.25O 3- δ > La 0.4Ca 0.6FeO 3- δ). In addition, comparison between the fluxes of samples of different thickness gave clear evidence of surface limitations in the oxygen transport. The long-term stability test showed opposite trends: only the two lowest Co containing compounds ( x=0 and 0.25) sustained an air/(Ar+H 2) gradient over more than 600 h. The other ( x=0.5) broke shortly after the introduction of H 2. In the presence of H 2, the oxygen flux was increased by a factor 10 compared to Ar and reached 0.83 μmol/cm 2 s for La 0.4Ca 0.6Fe 0.75Co 0.25O 3- δ at 900 °C. Post-operation SEM examination of the cross-section and both surfaces revealed that the surface exposed to H 2 had started to decompose resulting in the formation of a thin porous layer but the bulk of the material remained unchanged.

An Effect of the Co-Operative Network Model for Students' Quality in Thai Primary Schools

ERIC Educational Resources Information Center

Khanthaphum, Udomsin; Tesaputa, Kowat; Weangsamoot, Visoot

2016-01-01

This research aimed: 1) to study the current and desirable states of the co-operative network in developing the learners' quality in Thai primary schools, 2) to develop a model of the co-operative network in developing the learners' quality, and 3) to examine the results of implementation of the co-operative network model in the primary school.…

Changes in plants and soil microorganisms in an artificial CO2 leakage experiment

NASA Astrophysics Data System (ADS)

Ko, D.; Kim, Y.; Yoo, G.; Chung, H.

2017-12-01

Carbon capture and storage (CCS) technology is considered to be a promising technology that can mitigate global climate change by greatly reducing anthropogenic CO2 emissions. Despite the advantage, potential risks of leakage of CO2 from CO2 storage site exists, which may negatively affect organisms in the soil ecosystems. To investigate the short- term impacts of geological CO2 leakage on soil ecosystem, we conducted an artificial CO2 leakage experiment in a greenhouse where plants and soils were exposed to high levels of CO2. Corn was grown in a 1:1 (v/v) mixture of potting and field soil, and 99.99% CO2 gas was injected at a flow rate of 0.1l min-1 for 30 days whereas no gas was injected to control pots. Changes in plant growth, soil characteristics, and bacterial community composition were determined. Mean soil CO2 and O2 concentrations were 31.6% and 15.6%, respectively, in CO2-injected pots, while they were at ambient levels in control pots. The shoot and root length, and chlorophyll contents decreased in CO2-injected pots by 19.4%, 9.7%, and 11.9%, respectively. In addition, the concentration of available N such as NH4+-N and NO3-N was 83.3 to 90.8% higher in CO2-injected pots than in control pots likely due to inhibited plant growth. The results of bacterial 16S rRNA gene pyrosequencing showed that the major phyla in the soils were Actinobacteria, Proteobacteria, Acidobacteria, Chloroflexi, and Saccharibacteria_TM7. Among these, the relative abundance of Proteobacteria was lower in CO2-injected than in control pots (28.8% vs. 34.1%) likely due to decreased C availability. On the other hand, the abundance of Saccharibacteria_TM7 was significantly higher in CO2-injected than in control pots (6.0% vs. 1.3%). The changes in soil mineral N and microorganisms in response to injected CO2 was likely due to inhibited plant growth under high soil CO2 conditions, and further studies are needed to determine if belowground CO2 leakage from CO2 storage sites can directly affect soil microbial communities.

Microstructure, hyperfine interaction and magnetic transition of Fe-25%Ni-5%Si-x%Co alloys

NASA Astrophysics Data System (ADS)

Gungunes, H.

2016-12-01

Morphological and magnetic properties in Fe-25%Ni-5%Si-x%Co (x = 0, 10, 15) alloys are investigated. Scanning electron microscopy (SEM), Mössbauer spectroscopy and AC magnetic susceptibility measurements are used to determine the physical properties of alloys. The martensite morphology changed depending on the Co content. The Mössbauer study shows that the volume fraction and hyperfine field of martensite increases while isomer shift values decrease with increasing Co content. On the other hand; AC susceptibility results showed that; Co is an effective element which can be used to control both the magnetic transition and martensitic transformation temperatures.

Soil Phosphorus Stoichiometry Drives Carbon Turnover Along a Soil C Gradient Spanning Mineral and Organic Soils Under Rice Cultivation

NASA Astrophysics Data System (ADS)

Hartman, W.; Ye, R.; Horwath, W. R.; Tringe, S. G.

2014-12-01

Soil carbon (C) cycling is linked to the availability of nutrients like nitrogen (N) and phosphorus (P). However, the role of soil P in influencing soil C turnover and accumulation is poorly understood, with most models focusing on C:N ratios based on the assumption that terrestrial ecosystems are N limited. To determine the effects of N and P availability on soil C turnover, we compared soil respiration over the course of a growing season in four adjacent rice fields with 5%, 10%, 20% and 25% soil C. In each of these fields, plots were established to test the effect of N additions on plant growth, using control and N addition treatments (80 kg N/ha urea). Although soil P was not manipulated in parallel, prior work has shown soil P concentrations decline markedly with increasing soil C content. Soil CO2 flux was monitored using static chambers at biweekly intervals during the growing season, along with porewater dissolved organic C and ammonium. Soils were collected at the end of the growing season, and tested for total C, N, and P, extractable N and P, pH, base cations and trace metals. Soil DNA was also extracted for 16S rRNA sequencing to profile microbial communities. Soil N additions significantly increased CO2 flux and soil C turnover (seasonal CO2 flux per unit soil C) in 5% and 10% C fields, but not in 20% or 25% C fields. Soil C content was closely related to soil N:P stoichiometry, with N:P ratios of ca. 12, 16, 24, and 56 respectively in the 5, 10, 20 and 25% C fields. Seasonal CO2 fluxes (per m2) were highest in 10% C soils. However, soil C turnover was inversely related to soil C concentrations, with the greatest C turnover at the lowest values of soil C. Soil C turnover showed stronger relationships with soil chemical parameters than seasonal CO2 fluxes alone, and the best predictors of soil C turnover were soil total and extractable N:P ratios, along with extractable P alone. Our results show that soil P availability and stoichiometry influence the turnover of soil C, even where primary producers are clearly limited by N. Prior work has suggested these contrasting patterns in nutrient limitation may arise due to stoichiometric differences among plants and soil microbes. We hypothesize that differences in soil carbon turnover may in part reflect shifts in metabolism of microbial communities associated with stoichiometric variation in soils.

Guidance on Major Modification Provisions of PSD Rules as Applied to Re-Permitting at Acme Steel Co.

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Policy and Guidance Database available at www2.epa.gov/title-v-operating-permits/title-v-operating-permit-policy-and-guidance-document-index. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Order Responding to December 13, 2001 Request for the Administrator to Object to Operating Permit for Consolidated Edison Co. or NY, Inc.'s Ravenswood Steam Plant

EPA Pesticide Factsheets

This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

Effect of matured compost as an inoculating agent on odour removal and maturation of vegetable and fruit waste compost.

PubMed

Chen, Chih-Yu; Kuo, Jong-Tar; Chung, Ying-Chien

2013-01-01

The use of matured compost as an inoculation agent to improve the composting of vegetable and fruit wastes in a laboratory-scale composter was evaluated, and the commercial feasibility of this approach in a pilot-scale (1.8 x 10(4) L) composter was subsequently confirmed. The effect of aeration rate on the physico-chemical and biological properties of compost was also studied. Aeration rate affected the fermentation temperature, moisture content, pH, O2 consumption rate, CO2 production rate and the formation of odour. The optimal aeration rate was 2.5 L air/kg dry solid/min. The CO2 production rate approached the theoretical value during composting and was linearly dependent on temperature, indicating that the compost system had good operating characteristics. The inoculation of cellulolytic bacteria and deodorizing bacteria to compost in the pilot-scale composter led to an 18.2% volatile solids loss and a 64.3% volume reduction ratio in 52 h; only 1.5 ppm(v) odour was detected. This is the first study to focus on both operating performance and odour removal in a pilot-scale composter.

Making Co-Operative Ideas Work

ERIC Educational Resources Information Center

Arnold, Phil

2013-01-01

Reddish Vale Technology College was the first co-operative trust in England. The democratic and co-operative nature of the experiment mean that students have gained a greater voice in the organisation of the school. As a result, new social enterprises, environmental interventions, connections with the community and with the wider co-operative…

Influence of copper on nickel-based catalysts in the conversion of glycerol

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miranda, Barbara C.; Chimentao, Ricardo J.; Szanyi, Janos

2015-05-01

The catalytic transformation of glycerol to value-added compounds was investigated over bimetallic Ni-Cu/γ-Al2O3 catalysts with Ni/Cu atomic ratios of 8/1, 4/1, 2/1, 1/1, 1/2, 1/4, and 1/8. XPS analysis revealed that the surface composition of the catalyst exhibited progressive enrichment of Cu as its content in the catalyst increased. H2-chemisorption indicated that the total number of exposed Ni atoms decreased as the Cu content increased. As a result, deep hydrogenolysis to produce CH4 was inhibited by the addition of Cu to the Ni catalyst, yielding higher selectivity towards the dehydration products of glycerol such as hydroxyacetone. FTIR spectra of adsorbedmore » CO reveals that Cu asserts both geometric and electronic effects on the adsorption properties of Ni. The geometrical effect is visualized by the progressive disappearance of the bridge-bound adsorbed CO on metallic Ni by the incorporation of Cu. This suggests that the deep hydrogenolysis of glycerol to CH4 formation requires an ensemble of adjacent active Ni atoms. The electronic effect of Cu on Ni is indicated by the red shift of the IR peak of adsorbed CO as the Cu content increases. The electronic interaction between Cu and Ni species was also substantiated by XANES results. HTREM revealed metal particles very well distributed on the support with particle size of 1.5 to 5 nm. The Ni-Cu samples were not a total intermetallic alloys. We also gratefully acknowledge the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division for the support of this work. The research related to the FTIR of adsorption of CO (Proposal 48209) was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research located at Pacific Northwest National Laboratory (PNNL). PNNL is operated for the US DOE by Battelle Memorial Institute under contract number DE-AC05-76RL01830.« less