Electron and Oxygen Atom Transfer Chemistry of Co(II) in a Proton Responsive, Redox Active Ligand Environment.

Science.gov (United States)

Cook, Brian J; Pink, Maren; Pal, Kuntal; Caulton, Kenneth G

2018-05-21

The bis-pyrazolato pyridine complex LCo(PEt 3 ) 2 serves as a masked form of three-coordinate Co II and shows diverse reactivity in its reaction with several potential outer sphere oxidants and oxygen atom transfer reagents. N-Methylmorpholine N-oxide (NMO) oxidizes coordinated PEt 3 from LCo(PEt 3 ) 2 , but the final cobalt product is still divalent cobalt, in LCo(NMO) 2 . The thermodynamics of a variety of oxygen atom transfer reagents, including NMO, are calculated by density functional theory, to rank their oxidizing power. Oxidation of LCo(PEt 3 ) 2 with AgOTf in the presence of LiCl as a trapping nucleophile forms the unusual aggregate [LCo(PEt 3 ) 2 Cl(LiOTf) 2 ] 2 held together by Li + binding to very nucleophilic chloride on Co(III) and triflate binding to those Li + . In contrast, Cp 2 Fe + effects oxidation to trivalent cobalt, to form (HL)Co(PEt 3 ) 2 Cl + ; proton and the chloride originate from solvent in a rare example of CH 2 Cl 2 dehydrochlorination. An unexpected noncomplementary redox reaction is reported involving attack by 2e reductant PEt 3 nucleophile on carbon of the 1e oxidant radical Cp 2 Fe + , forming a P-C bond and H + ; this reaction competes in the reaction of LCo(PEt 3 ) 2 with Cp 2 Fe + .

International co-operation

International Nuclear Information System (INIS)

Klinda, J.; Lieskovska, Z.

1998-01-01

Within the Union Nations (UN) framework, the Slovak Republic participated in following activities on environment protection co-operation: UN European Economic Commission, UN Industrial Development Organization, UN Development Programme, UN Human Habitat Organization, UN Environment Programme, and UN Commission on Sustainable Development. Relevant activities of the Slovak Republic in these co-operations as well as in European Union and OECD activities are reviewed. International conventions and other forms of multilateral co-operation, bilateral co-operation, and international programmes and projects in which the Slovak Republic took participate are presented

Controlling exchange bias in Co-CoOx nanoparticles by oxygen content

OpenAIRE

Kovylina, Miroslavna; del Muro, Montserrat Garcia; Konstantinovic, Zorica; Varela, Manuel; Iglesias, Oscar; Labarta, Amilcar; Batlle, Xavier

2009-01-01

We report on the occurrence of exchange bias on laser-ablated granular thin films composed of Co nanoparticles embedded in amorphous zirconia matrix. The deposition method allows controlling the degree of oxidation of the Co particles by tuning the oxygen pressure at the vacuum chamber (from 2x10^{-5} to 10^{-1} mbar). The nature of the nanoparticles embedded in the nonmagnetic matrix is monitored from metallic, ferromagnetic (FM) Co to antiferromagnetic (AFM) CoOx, with a FM/AFM intermediate...

Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from CO2

Data.gov (United States)

National Aeronautics and Space Administration — Oxygen recovery from respiratory CO2 is an important aspect of human spaceflight. Methods exist to sequester the CO2­, but production of oxygen needs further...

Operating a production facility without a CO and O agreement

International Nuclear Information System (INIS)

Smith, M. R.

2000-01-01

Issues that arise when an oil or natural gas facility is operated without a specific construction, ownership and operating (CO and O) agreement was explored. The lack of such an agreement may be due to the parties' inability to reach agreement, reliance on the land operating agreement, or the lack of diligent follow-up on the drafting, revision and execution of operating agreements. The paper examines the nature of ownership interests that obtain in the absence of a CO and O, the common situation in respect to CO and O agreements where the document has been circulated but has not been signed by the owners. A number of actual cases were cited to illustrate the effects of such an omission. It was concluded that ideally, a fully executed CO and O for each facility which deals specifically with the owners involved with the particular facility is the best of all worlds. However given the nature of some facilities, the expense, time and effort required to prepare and execute a separate CO and O, it is frequently omitted; in such situations it is convenient to fall back on the 1990 Operating Procedure of CAPL, which while general in nature and cannot adequately deal with every situation, deals with many common problems associated with the operation of facilities. It is recommended that even if a complete CO and O agreement cannot be executed, interim binding agreements should be used to avoid uncertainty until such time as a complete agreement can be finalized. A clause-by-clause comparison of the 1990 CAPL Operating Procedure and a 1996 model CO and O agreement, prepared by the Petroleum Joint Venture Association (PJVA), is appended

Photofunctional Co-Cr Alloy Generating Reactive Oxygen Species for Photodynamic Applications

Directory of Open Access Journals (Sweden)

Kang-Kyun Wang

2013-01-01

Full Text Available We report the fabrication of photofunctional Co-Cr alloy plate that is prepared by a simple modification process for photodynamic application. Photoinduced functionality is provided by the photosensitizer of hematoporphyrin (Hp that initially generates reactive oxygen species (ROS such as superoxide anion radical and singlet oxygen. The photosensitizer with carboxyl group was chemically bonded to the surface of the Co-Cr alloy plate by esterification reaction. Microstructure and elemental composition of the Co-Cr alloy plate were checked with scanning electron microscopy (SEM and energy dispersive X-ray spectrometer (EDS. Fabrication of the photofunctionality of the Co-Cr alloy plate was confirmed with X-ray photoelectron spectroscopy (XPS, reflectance UV-Vis absorption, and emission spectroscopy. Reactive oxygen generation from the photofunctional Co-Cr alloy plate was confirmed by using the decomposition reaction of 1,3-diphenylisobenzofuran (DPBF. The results suggest that the immobilized photosensitizer molecules on the surface of Co-Cr alloy plate still possess their optical and functional properties including reactive oxygen generation. To open the possibility for its application as a photodynamic material to biological system, the fabricated photofunctional Co-Cr alloy is applied to the decomposition of smooth muscle cells.

Co-combustion of biodiesel with oxygenated fuels in direct injection diesel engine

Directory of Open Access Journals (Sweden)

Tutak Wojciech

2017-01-01

Full Text Available The paper presents results of experimental investigation of cocombustion process of biodiesel (B100 blended with oxygenated fuels with 20% in volume. As the alternative fuels ware used hydrated ethanol, methanol, 1-butanol and 2-propanol. It was investigated the influence of used blends on operating parameters of the test engine and exhaust emission (NOx, CO, THC, CO2. It is observed that used blends are characterized by different impact on engine output power and its efficiency. Using biodiesel/alcohol blend it is possible to improve engine efficiency with small drop in indicated mean effective pressure (IMEP. Due to combustion characteristic of biodiesel/alcohol obtained a slightly larger specific NOx emission. It was also observed some differences in combustion phases due to various values of latent heat of evaporation of used alcohols and various oxygen contents. Test results confirmed that the combustion process occurring in the diesel engine powered by blend takes place in a shorter time than in the typical diesel engine.

Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

Science.gov (United States)

Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

2016-01-01

For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

Oxygen Storage Capacity and Oxygen Mobility of Co-Mn-Mg-Al Mixed Oxides and Their Relation in the VOC Oxidation Reaction

Directory of Open Access Journals (Sweden)

María Haidy Castaño

2015-05-01

Full Text Available Co-Mn-Mg-Al oxides were synthesized using auto-combustion and co-precipitation techniques. Constant ratios were maintained with (Co + Mn + Mg/Al equal to 3.0, (Co + Mn/Mg equal to 1.0 and Co/Mn equal to 0.5. The chemical and structural composition, redox properties, oxygen storage capacity and oxygen mobility were analyzed using X-ray fluorescence (XRF, X-ray diffraction (XRD, Raman spectroscopy, scanning electron microscopy (SEM, temperature-programmed reduction of hydrogen (H2-TPR, oxygen storage capacity (OSC, oxygen storage complete capacity (OSCC and isotopic exchange, respectively. The catalytic behavior of the oxides was evaluated in the total oxidation of a mixture of 250 ppm toluene and 250 ppm 2-propanol. The synthesis methodology affected the crystallite size, redox properties, OSC and oxide oxygen mobility, which determined the catalytic behavior. The co-precipitation method got the most active oxide in the oxidation of the volatile organic compound (VOC mixture because of the improved mobility of oxygen and ability to favor redox processes in the material structure.

Controlling exchange bias in Co-CoOx nanoparticles by oxygen content

International Nuclear Information System (INIS)

Kovylina, Miroslavna; Muro, Montserrat GarcIa del; Konstantinovic, Zorica; Iglesias, Oscar; Labarta, AmIlcar; Batlle, Xavier; Varela, Manuel

2009-01-01

We report on the occurrence of exchange bias on laser-ablated granular thin films composed of Co nanoparticles embedded in an amorphous zirconia matrix. The deposition method allows one to control the degree of oxidation of the Co particles by tuning the oxygen pressure at the vacuum chamber (from 2 x 10 -5 to 10 -1 mbar). The nature of the nanoparticles embedded in the nonmagnetic matrix is monitored from metallic, ferromagnetic (FM) Co to antiferromagnetic (AFM) CoO x , with a FM/AFM intermediate regime for which the percentage of the AFM phase can be increased at the expense of the FM phase, leading to the occurrence of exchange bias in particles of about 2 nm in size. For an oxygen pressure of about 10 -3 mbar the ratio between the FM and AFM phases is optimum with an exchange bias field of about 900 Oe at 1.8 K. The mutual exchange coupling between the AFM and FM is also at the origin of the induced exchange anisotropy on the FM leading to high irreversible hysteresis loops, and the blocking of the AFM clusters due to proximity to the FM phase.

Acyl-CoA binding protein and epidermal barrier function

DEFF Research Database (Denmark)

Bloksgaard, Maria; Neess, Ditte; Færgeman, Nils J

2014-01-01

The acyl-CoA binding protein (ACBP) is a 10kDa intracellular protein expressed in all eukaryotic species and mammalian tissues investigated. It binds acyl-CoA esters with high specificity and affinity and is thought to act as an intracellular transporter of acyl-CoA esters between different...... includes tousled and greasy fur, development of alopecia and scaling of the skin with age. Furthermore, epidermal barrier function is compromised causing a ~50% increase in transepidermal water loss relative to that of wild type mice. Lipidomic analyses indicate that this is due to significantly reduced...

International co-operation

International Nuclear Information System (INIS)

1997-01-01

In 1996, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured the Slovak Republic (SR) obligations with relation to the international agreements and with the SR membership in the IAEA.International co-operation has been ensured on the basis of the bilateral international agreements. With the Ministry of Foreign Affairs co-operation, the SR fulfilled its financial obligations to this organization in due time and in the full scope. Representing Central and Eastern Europe interest in the Board of Governors, the SR participation in the highest executive in the highest executive authority was finished in 1996.The Board of Governors Vice-chairman position was executed by NRA SR Chairman. 5 national and 6 regional technical co-operation and assistance projects were realized in 1996. 12 organizations participated in these projects and accordingly 104 experts took part in training programmes, scientific visits or as the mission members abroad. Besides, Slovak experts participated at work of technical advisory and consultation groups with the significant assistance. In the framework of IAEA co-operation, the SR was visited by 11 expert missions formed by 28 experts from 19 countries including IAEA. Slovak organizations, namely institutes of the Academy of Sciences, Slovak research centres and universities participated in IAEA scientific and research activities through NRA SR. 15 scientific contracts in total were approved and realized and these contracts are utilized as supplementary financing of the own scientific and research projects. Other international co-operation and regional co-operation activities of the NRA SR in 1996 are reviewed

Transnational Research Co-operation: Opportunities and Challenges for transnational research co-operation

DEFF Research Database (Denmark)

of the NGOs have a lot of international experience (mainly in Denmark and Germany) as partners in different co-operation projects. Almost all the NGOs have recognized the important role of the scientific information in their activity. NGOs also feel the need for an easy access to required information...... for transnational co-operation like: an investigation/project concerning the driving forces behind urban development,or a co-operation in the field of wastewater reuse and minimization of wastewater loads and discharge, or a service page (internet) to search for potential partners. The governmental institutions...... in order to improve transnational cooperation are identified to be: • Search for national/international project partners • Access to existent co-operation projects or networks • Develop in common project proposals on themes requested by community groups • Exchange information/good operational practices...

Broad Phylogenetic Occurrence of the Oxygen-Binding Hemerythrins in Bilaterians.

Science.gov (United States)

Costa-Paiva, Elisa M; Schrago, Carlos G; Halanych, Kenneth M

2017-10-01

Animal tissues need to be properly oxygenated for carrying out catabolic respiration and, as such, natural selection has presumably favored special molecules that can reversibly bind and transport oxygen. Hemoglobins, hemocyanins, and hemerythrins (Hrs) fulfill this role, with Hrs being the least studied. Knowledge of oxygen-binding proteins is crucial for understanding animal physiology. Hr genes are present in the three domains of life, Archaea, Bacteria, and Eukaryota; however, within Animalia, Hrs has been reported only in marine species in six phyla (Annelida, Brachiopoda, Priapulida, Bryozoa, Cnidaria, and Arthropoda). Given this observed Hr distribution, whether all metazoan Hrs share a common origin is circumspect. We investigated Hr diversity and evolution in metazoans, by employing in silico approaches to survey for Hrs from of 120 metazoan transcriptomes and genomes. We found 58 candidate Hr genes actively transcribed in 36 species distributed in 11 animal phyla, with new records in Echinodermata, Hemichordata, Mollusca, Nemertea, Phoronida, and Platyhelminthes. Moreover, we found that "Hrs" reported from Cnidaria and Arthropoda were not consistent with that of other metazoan Hrs. Contrary to previous suggestions that Hr genes were absent in deuterostomes, we find Hr genes present in deuterostomes and were likely present in early bilaterians, but not in nonbilaterian animal lineages. As expected, the Hr gene tree did not mirror metazoan phylogeny, suggesting that Hrs evolutionary history was complex and besides the oxygen carrying capacity, the drivers of Hr evolution may also consist of secondary functional specializations of the proteins, like immunological functions. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Atomically layer-by-layer diffusion of oxygen/hydrogen in highly epitaxial PrBaCo{sub 2}O{sub 5.5+δ} thin films

Energy Technology Data Exchange (ETDEWEB)

Bao, Shanyong; Xu, Xing; Enriquez, Erik; Mace, Brennan E.; Chen, Garry; Kelliher, Sean P.; Chen, Chonglin, E-mail: cl.chen@utsa.edu [Department of Physics and Astronomy, University of Texas, San Antonio, Texas 78249 (United States); Zhang, Yamei [Department of Physics, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212003 (China); Whangbo, Myung-Hwan [North Carolina State University, Raleigh, North Carolina 27695-8204 (United States); Dong, Chuang; Zhang, Qinyu [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024 (China)

2015-12-14

Single-crystalline epitaxial thin films of PrBaCo{sub 2}O{sub 5.5+δ} (PrBCO) were prepared, and their resistance R(t) under a switching flow of oxidizing and reducing gases were measured as a function of the gas flow time t in the temperature range of 200–800 °C. During the oxidation cycle under O{sub 2}, the PrBCO films exhibit fast oscillations in their dR(t)/dt vs. t plots, which reflect the oxidation processes, Co{sup 2+}/Co{sup 3+} → Co{sup 3+} and Co{sup 3+} → Co{sup 3+}/Co{sup 4+}, that the Co atoms of PrBCO undergo. Each oscillation consists of two peaks, with larger and smaller peaks representing the oxygen/hydrogen diffusion through the (BaO)(CoO{sub 2})(PrO)(CoO{sub 2}) layers of PrBCO via the oxygen-vacancy-exchange mechanism. This finding paves a significant avenue for cathode materials operating in low-temperature solid-oxide-fuel-cell devices and for chemical sensors with wide range of operating temperature.

Successful Treatment of Severe Carbon Monoxide Poisoning and Refractory Shock Using Extracorporeal Membrane Oxygenation.

Science.gov (United States)

Teerapuncharoen, Krittika; Sharma, Nirmal S; Barker, Andrew B; Wille, Keith M; Diaz-Guzman, Enrique

2015-09-01

Carbon monoxide (CO) is the most common cause of poisoning and poisoning-related death in the United States. It is a tasteless and odorless poisonous gas produced from incomplete combustion of hydrocarbons, such as those produced by cars and heating systems. CO rapidly binds to hemoglobin to form carboxyhemoglobin, leading to tissue hypoxia, multiple-organ failure, and cardiovascular collapse. CO also binds to myocardial myoglobin, preventing oxidative phosphorylation in cardiac mitochondria and resulting in cardiac ischemia or stunning and cardiogenic pulmonary edema. Treatment of CO poisoning is mainly supportive, and supplemental oxygen remains the cornerstone of therapy, whereas hyperbaric oxygen therapy is considered for patients with evidence of neurological and myocardial injury. Extracorporeal membrane oxygenation (ECMO) has been utilized effectively in patients with respiratory failure and hemodynamic instability, but its use has rarely been reported in patients with CO poisoning. We report the successful use of venoarterial ECMO in a patient with severe CO poisoning and multiple-organ failure. Copyright © 2015 by Daedalus Enterprises.

Co-Occurring Atomic Contacts for the Characterization of Protein Binding Hot Spots

Science.gov (United States)

Liu, Qian; Ren, Jing; Song, Jiangning; Li, Jinyan

2015-01-01

A binding hot spot is a small area at a protein-protein interface that can make significant contribution to binding free energy. This work investigates the substantial contribution made by some special co-occurring atomic contacts at a binding hot spot. A co-occurring atomic contact is a pair of atomic contacts that are close to each other with no more than three covalent-bond steps. We found that two kinds of co-occurring atomic contacts can play an important part in the accurate prediction of binding hot spot residues. One is the co-occurrence of two nearby hydrogen bonds. For example, mutations of any residue in a hydrogen bond network consisting of multiple co-occurring hydrogen bonds could disrupt the interaction considerably. The other kind of co-occurring atomic contact is the co-occurrence of a hydrophobic carbon contact and a contact between a hydrophobic carbon atom and a π ring. In fact, this co-occurrence signifies the collective effect of hydrophobic contacts. We also found that the B-factor measurements of several specific groups of amino acids are useful for the prediction of hot spots. Taking the B-factor, individual atomic contacts and the co-occurring contacts as features, we developed a new prediction method and thoroughly assessed its performance via cross-validation and independent dataset test. The results show that our method achieves higher prediction performance than well-known methods such as Robetta, FoldX and Hotpoint. We conclude that these contact descriptors, in particular the novel co-occurring atomic contacts, can be used to facilitate accurate and interpretable characterization of protein binding hot spots. PMID:26675422

Formation and Migration of Oxygen Vacancies in SrCoO3 and their effect on Oxygen Evolution Reactions

KAUST Repository

Tahini, Hassan A.; Tan, Xin; Schwingenschlö gl, Udo; Smith, Sean C.

2016-01-01

Perovskite SrCoO3 is a potentially useful material for promoting the electrocatalytic oxygen evolution reaction, with high activities predicted theoretically and observed experimentally for closely related doped perovskite materials. However, complete stoichiometric oxidation is very difficult to realize experimentally – in almost all cases there are significant fractions of oxygen vacancies present. Here, using first principles calculations we study oxygen vacancies in perovskite SrCoO3 from thermodynamic, electronic and kinetic points of view. We find that an oxygen vacancy donates two electrons to neighboring Co sites in the form of localized charge. The formation energy of a single vacancy is very low and estimated to be 1.26 eV in the dilute limit. We find that a vacancy is quite mobile with a migration energy of ~0.5 eV. Moreover, we predict that oxygen vacancies exhibit a tendency towards clustering which is in accordance with the material’s ability to form a variety of oxygen-deficient structures. These vacancies have a profound effect on the material’s ability to facilitate OER, increasing the overpotential from ~0.3 V for the perfect material to ~0.7 for defective surfaces. A moderate compressive biaxial strain (2%) is predicted here to increase the surface oxygen vacancy formation energy by ca. 30%, thus reducing the concentration of surface vacancies and thereby preserving the OER activity of the material.

Formation and Migration of Oxygen Vacancies in SrCoO3 and their effect on Oxygen Evolution Reactions

KAUST Repository

Tahini, Hassan A.

2016-07-18

Perovskite SrCoO3 is a potentially useful material for promoting the electrocatalytic oxygen evolution reaction, with high activities predicted theoretically and observed experimentally for closely related doped perovskite materials. However, complete stoichiometric oxidation is very difficult to realize experimentally – in almost all cases there are significant fractions of oxygen vacancies present. Here, using first principles calculations we study oxygen vacancies in perovskite SrCoO3 from thermodynamic, electronic and kinetic points of view. We find that an oxygen vacancy donates two electrons to neighboring Co sites in the form of localized charge. The formation energy of a single vacancy is very low and estimated to be 1.26 eV in the dilute limit. We find that a vacancy is quite mobile with a migration energy of ~0.5 eV. Moreover, we predict that oxygen vacancies exhibit a tendency towards clustering which is in accordance with the material’s ability to form a variety of oxygen-deficient structures. These vacancies have a profound effect on the material’s ability to facilitate OER, increasing the overpotential from ~0.3 V for the perfect material to ~0.7 for defective surfaces. A moderate compressive biaxial strain (2%) is predicted here to increase the surface oxygen vacancy formation energy by ca. 30%, thus reducing the concentration of surface vacancies and thereby preserving the OER activity of the material.

Agricultural Co-Operatives in Ethiopia

NARCIS (Netherlands)

Tefera, Delelegne A.; Bijman, Jos; Slingerland, Maja A.

2017-01-01

To what extent can co-operatives strengthen rural development in sub-Saharan Africa? This paper explores the development of agricultural co-operatives in Ethiopia, particularly the changes in economic functions. Co-operative development in Ethiopia has been strongly influenced by various political

EPR study of manganese(II) binding to 55'-ATP, hemoglobin, and hemocyanin

Energy Technology Data Exchange (ETDEWEB)

Chang, S.S. (Duquesne Univ., Pittsburgh); Li, N.C.; Pratt, D.W.

1975-01-01

Several divalent metal ions affect the oxygen affinity of hemoglobin and hemocyanin. It is important, therefore, to understand the nature of metal-ion binding to these proteins. By comparing the EPR spectra of Mn(II), 0.001 M, in the absence and presence of carboxyhemoglobin or Limulus oxyhemocyanin (pH 7.3, Trizma buffer), the number of Mn binding sites, n, and the binding constant, K, can be determined. For carboxyhemoglobin, HbCO, we find 0.5 Mn binding sites per heme, K = 450 M/sup -1/. Each hemoglobin tetramer therefore binds two manganous ions suggesting that Mn(II), like Cu(II), may bind preferentially to one of the two types of subunits in hemoglobin. For hemocyanin, HcO/sub 2/, we find n = 5.8, K = 1.55 x 10/sup 3/ M/sup -1/. Each oxyhemocyanine therefore binds approximately six manganous ions, and the binding constant is three times larger than that for HbCO. We have also carried out similar experiments on 5'-ATP, and on solutions of HbCO and ATP containing McCl/sub 2/ or ZnCl/sub 2/. Zn(II) effectively competes with Mn(II) in binding hemoglobin and ATP, whereas Mg(II) does not, in accord with expectations from data on oxygen affinity of hemoglobin. (auth)

Disruption of key NADH-binding pocket residues of the Mycobacterium tuberculosis InhA affects DD-CoA binding ability.

Science.gov (United States)

Shaw, Daniel J; Robb, Kirsty; Vetter, Beatrice V; Tong, Madeline; Molle, Virginie; Hunt, Neil T; Hoskisson, Paul A

2017-07-05

Tuberculosis (TB) is a global health problem that affects over 10 million people. There is an urgent need to develop novel antimicrobial therapies to combat TB. To achieve this, a thorough understanding of key validated drug targets is required. The enoyl reductase InhA, responsible for synthesis of essential mycolic acids in the mycobacterial cell wall, is the target for the frontline anti-TB drug isoniazid. To better understand the activity of this protein a series of mutants, targeted to the NADH co-factor binding pocket were created. Residues P193 and W222 comprise a series of hydrophobic residues surrounding the cofactor binding site and mutation of both residues negatively affect InhA function. Construction of an M155A mutant of InhA results in increased affinity for NADH and DD-CoA turnover but with a reduction in V max for DD-CoA, impairing overall activity. This suggests that NADH-binding geometry of InhA likely permits long-range interactions between residues in the NADH-binding pocket to facilitate substrate turnover in the DD-CoA binding region of the protein. Understanding the precise details of substrate binding and turnover in InhA and how this may affect protein-protein interactions may facilitate the development of improved inhibitors enabling the development of novel anti-TB drugs.

Biodegradation of poly(lactic acid, poly(hydroxybutyrate-co-hydroxyvalerate, poly(butylene succinate and poly(butylene adipate-co-terephthalate under anaerobic and oxygen limited thermophilic conditions

Directory of Open Access Journals (Sweden)

Jutakan Boonmee

2016-01-01

Full Text Available In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid (PLA, poly(hydroxybutyrate-co-hydroxyvalerate (PHBV, poly(butylene succinate (PBS, and poly(butylene adipate-co-terephthalate (PBAT were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of biodegradation after 75 days was investigated by weight loss determination, visual examination, and surface appearance by scanning electronic microscopy (SEM. Under both anaerobic and oxygen limited conditions, the complete degradation (100% weight loss was found only in PHBV after 75 days. The plastic degradations were ranked in the order of PHBV> PLA> PBS> PBAT. The percentage of weight losses were significantly different at p ≤ 0.05. However, for all studied plastics, the degradation under anaerobic and oxygen limited conditions did not significantly different at 95% confidence.

Acyl-CoA-binding protein (ACBP) can mediate intermembrane acyl-CoA transport and donate acyl-CoA for beta-oxidation and glycerolipid synthesis

DEFF Research Database (Denmark)

Rasmussen, J T; Færgeman, Nils J.; Kristiansen, K

1994-01-01

The dissociation constants for octanoyl-CoA, dodecanoyl-CoA and hexadecanoyl-CoA binding to acyl-CoA-binding protein (ACBP) were determined by using titration microcalorimetry. The KD values obtained, (0.24 +/- 0.02) x 10(-6) M, (0.65 +/- 0.2) x 10(-8) M and (0.45 +/- 0.2) x 10(-13) M respectively......, were much lower than expected. ACBP was able to extract hexadecanoyl-CoA from phosphatidylcholine membranes immobilized on a nitrocellulose membrane. The acyl-CoA/ACBP complex formed was able to transport acyl-CoA to mitochondria or microsomes in suspension, or to microsomes immobilized...

Effect of oxygen co-injected with carbon dioxide on Gothic shale caprock–CO₂–brine interaction during geologic carbon sequestration

Energy Technology Data Exchange (ETDEWEB)

Jung, Hun Bok; Um, Wooyong; Cantrell, Kirk J.

2013-09-01

Co-injection of oxygen, a significant component in CO₂ streams produced by the oxyfuel combustion process, can cause a significant alteration of the redox state in deep geologic formations during geologic carbon sequestration. The potential impact of co-injected oxygen on the interaction between synthetic CO₂–brine (0.1 M NaCl) and shale caprock (Gothic shale from the Aneth Unit in Utah) and mobilization of trace metals was investigated at ~ 10 MPa and ~ 75 °C. A range of relative volume percentages of O₂ to CO₂ (0, 1, 4 and 8%) were used in these experiments to address the effect of oxygen on shale–CO₂–brine interaction under various conditions. Major mineral phases in Gothic shale are quartz, calcite, dolomite, montmorillonite, and pyrite. During Gothic shale–CO₂–brine interaction in the presence of oxygen, pyrite oxidation occurred extensively and caused enhanced dissolution of calcite and dolomite. Pyrite oxidation and calcite dissolution subsequently resulted in the precipitation of Fe(III) oxides and gypsum (CaSO₄·2H₂O). In the presence of oxygen, dissolved Mn and Ni were elevated because of oxidative dissolution of pyrite. The mobility of dissolved Ba was controlled by barite (BaSO₄) precipitation in the presence of oxygen. Dissolved U in the experimental brines increased to ~ 8–14 μg/L, with concentrations being slightly higher in the absence of oxygen than in the presence of oxygen. Experimental and modeling results indicate the interaction between shale caprock and oxygen co-injected with CO₂ during geologic carbon sequestration can exert significant impacts on brine pH, solubility of carbonate minerals, stability of sulfide minerals, and mobility of trace metals. The major impact of oxygen is most likely to occur in the zone near CO₂ injection wells where impurity gases can accumulate. Finally, oxygen in CO₂

Oxygen binding to nitric oxide marked hemoglobin

International Nuclear Information System (INIS)

Louro, S.R.W.; Ribeiro, P.C.; Bemski, G.

1979-04-01

Electron spin resonance spectra of organic phosphate free human hemoglobin marked with nitric oxide at the sixth coordination position of one of the four hemes allow to observe the transition from the tense (T) to the relaxed (R) conformation, as a function of parcial oxygen pressure. The spectra are composites of contributions from α sub(T), α sub(R) and β chains spectra, showing the presence of only two conformations: T and R. In the absence of organic phosphates NO binds to α and β chains with the same probability, but in the presence of phosphates NO combines preferentially with α chains. The dissociation of NO proceeds at least an order of magnitude faster in T than in R configuration. (author) [pt

De-oxygenation of CO2 by using Hydrogen, Carbon and Methane over Alumina-Supported Catalysts

Directory of Open Access Journals (Sweden)

R.Y. Raskar

2012-06-01

Full Text Available The de-oxygenation of CO2 was explored by using hydrogen, methane, carbon etc., over alumina supported catalysts. The alumina-supported ruthenium, rhodium, platinum, molybdenum, vanadium and magnesium catalysts were first reduced in hydrogen atmosphere and then used for the de-oxygenation of CO2. Furthermore, experimental variables for the de-oxygenation of CO2 were temperature (range 50 to 650 oC, H2/CO2 mole ratios (1.0 to 5, and catalyst loading (0.5 to 10 wt %. During the de-oxygenation of CO2 with H2 or CH4 or carbon, conversion of CO2, selectivity to CO and CH4 were estimated. Moreover, 25.4 % conversion of CO2 by hydrogen was observed over 1 wt% Pt/Al2O3 catalyst at 650 oC with 33.8 % selectivity to CH4. However, 8.1 to 13.9 % conversion of CO2 was observed over 1 wt% Pt/Al2O3 catalyst at 550 oC in the presence of both H2 and CH4. Moreover, 42.8 to 79.4 % CH4 was converted with 9 to 23.1 % selectivity to CO. It was observed that the de-oxygenation of CO2 by hydrogen, carbon and methane produced carbon, CO and CH4. © 2012 BCREC UNDIP. All rights reservedReceived: 6th February 2012; Revised: 23rd April 2012; Accepted: 24th April 2012[How to Cite: R. Y. Raskar, K. B. Kale, A. G. Gaikwad. (2011. De-oxygenation of CO2 by using Hydrogen, Carbon and Methane over Alumina-Supported Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1: 59-69.  doi:10.9767/bcrec.7.1.1631.59-69][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1631.59-69 ] | View in 

Phase transitions in ZnTe co-doped with Mg and oxygen

Energy Technology Data Exchange (ETDEWEB)

Elyukhin, V.A.; Sorokina, L.P. [Departamento de Ingenieria Electrica, CINVESTAV-IPN, Av. IPN 2508, Mexico, D.F., 07360 (Mexico); Rodriguez de Santiago, M. [Departamento de Ingenieria Quimica Petrolera, IPN, Edif. 8, Mexico, D.F., 07738 (Mexico)

2007-05-15

Self-assembling of 1O4Mg tetrahedral clusters in ZnTe isoelectronically co-doped with Mg and oxygen in the ultra dilute oxygen impurity limit is described by a phase diagram. The occurrence of 1O4Mg clusters is a result of the second-order transition. The final stage of self-assembling when all oxygen impurities are in 1O4Mg clusters has to be reached also as a result of the second-order transition at the temperature close to the temperature of the occurrence of these clusters. The conditions of these phase transitions are obtained. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Adsorption of atomic oxygen on PdAg/Pd(111) surface alloys and coadsorption of CO

Energy Technology Data Exchange (ETDEWEB)

Farkas, Arnold P. [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany); Reaction Kinetics Research Group, University of Szeged, Chemical Research Center of the Hungarian Academy of Sciences, H-6720 Szeged (Hungary); Bansmann, Joachim; Diemant, Thomas; Behm, R. Juergen [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany)

2011-07-01

The interaction of dissociated oxygen with structurally well-defined PdAg/Pd(111) surface alloys and the coadsorption of CO was studied by high resolution electron energy loss spectroscopy (HREELS) and temperature-programmed desorption (TPD). After oxygen saturation of the non-modified Pd(111) surface at RT, we observed the formation of a prominent peak in the HREEL spectra at 60 meV corresponding to the perpendicular vibration of oxygen atoms adsorbed in threefold hollow sites. Deposition of small Ag amounts does not change the signal intensity of this peak; it decreases only above 20% Ag. Beyond this Ag content, the peak intensity steeply declines and disappears at around 55-60% Ag. CO coadsorption on the oxygen pre-covered surfaces at 120 K leads to the formation of additional features in HREELS. For a surface alloy with 29% Ag, three loss features due to CO adsorption in on-top, bridge, and threefold-hollow sites can be discriminated already after the lowest CO exposure. Annealing of the co-adsorbed layer to 200 K triggers a decrease of the oxygen concentration due to CO{sub 2} formation. These findings are corroborated by TPD spectra of the CO desorption and CO{sub 2} production.

Probing the structural basis of oxygen binding in a cofactor-independent dioxygenase.

Science.gov (United States)

Li, Kunhua; Fielding, Elisha N; Condurso, Heather L; Bruner, Steven D

2017-07-01

The enzyme DpgC is included in the small family of cofactor-independent dioxygenases. The chemistry of DpgC is uncommon as the protein binds and utilizes dioxygen without the aid of a metal or organic cofactor. Previous structural and biochemical studies identified the substrate-binding mode and the components of the active site that are important in the catalytic mechanism. In addition, the results delineated a putative binding pocket and migration pathway for the co-substrate dioxygen. Here, structural biology is utilized, along with site-directed mutagenesis, to probe the assigned dioxygen-binding pocket. The key residues implicated in dioxygen trafficking were studied to probe the process of binding, activation and chemistry. The results support the proposed chemistry and provide insight into the general mechanism of dioxygen binding and activation.

Kinetics and mechanism of oxygen reduction reaction at CoPd system synthesized on XC72

International Nuclear Information System (INIS)

Tarasevich, M.R.; Chalykh, A.E.; Bogdanovskaya, V.A.; Kuznetsova, L.N.; Kapustina, N.A.; Efremov, B.N.; Ehrenburg, M.R.; Reznikova, L.A.

2006-01-01

Studies are presented of the kinetics and mechanism of oxygen electroreduction reaction on CoPd catalysts synthesized on carbon black XC72. As shown both in model conditions and in the tests within the cathodes of hydrogen-oxygen fuel cells with proton conducting electrolyte, CoPd/C system features a higher activity, as compared to Co/C. The highest activity in the oxygen reduction reaction is demonstrated by the catalysts with the Pd:Co atomic ratio being 7:3 and 4:1. The structural studies (XPS and XRD, and also the data of CO desorption measurements) evidence the CoPd alloy formation, which is reflected in the negative shift of the bonding energy maximum as compared to Pd/C and in the appearance of the additional CO desorption maximums on the voltammograms. It is found by means of structural research that CoPd alloy is formed in the course of the catalyst synthesis which features a higher catalytic activity of the binary systems. Besides, CoPd/C catalyst is more stable in respect to corrosion than Pd supported on carbon black. The measurements on the rotating disc electrode and rotating ring-disc electrode evidence that CoPd/C system provides the predominant oxygen reduction to water in the practically important range of potentials (E > 0.7 V). The proximity of kinetic parameters of the oxygen reduction reaction on CoPd/C and Pt/C catalysts points to the similar reaction mechanism. The slow step of the reaction is the addition of the first electron to the adsorbed and previously protonated O 2 molecule. The assumptions are offered about the reasons causing the higher activity and selectivity of the binary catalyst towards oxygen reduction to water, as compared to Co/C. The studies of the most active catalysts within the fuel cell cathodes are performed

Oxygen Toxicity and Special Operations Forces Diving: Hidden and Dangerous

NARCIS (Netherlands)

Wingelaar, Thijs T.; van Ooij, Pieter-Jan A. M.; van Hulst, Rob A.

2017-01-01

In Special Operations Forces (SOF) closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2) could cause damage to the central nervous system (CNS) and pulmonary system. Longer exposure time and higher PO2 leads

Influence of Structure and Charge State on the Mechanism of CO Oxidation on Gold Clusters

Science.gov (United States)

Johnson, Grant; Burgel, Christian; Reilly, Nelly; Mitric, Roland; Kimble, Michele; Tyo, Eric; Castleman, A. W.; Bonacic-Koutecky, Vlasta

2008-05-01

Gas-phase reactivity experiments and high level theoretical calculations have been employed to study the interaction of both positively and negatively charged gold oxide clusters with carbon monoxide (CO). We demonstrate that for negatively charged clusters CO is oxidized to CO2 by an Eley-Ridel-like (ER-) mechanism involving the attack of CO on oxygen rather than gold. In contrast, for positively charged clusters, the oxidation reaction may also occur by a Langmuir-Hinshelwood-like (LH-) mechanism involving the initial binding of CO to a gold atom followed by subsequent migration to an oxygen site. The LH mechanism is made possible through the large energy gain associated with the adsorption of two CO molecules onto cationic gold clusters. Structure-reactivity relationships are also established which demonstrate that terminally bound oxygen atoms are the most active sites for CO oxidation. Bridge bonded oxygen atoms and molecularly bound O2 units are shown to be inert. We also establish an inverse relationship between the binding energy of CO to gold clusters and the energy of the clusters lowest unoccupied molecular orbital (LUMO).

Co-operatives as heating entrepreneurs

International Nuclear Information System (INIS)

Honkasalo, M.

2000-01-01

The objective of heating entrepreneurship functioning in the form of a co operative is to make the use of the wood chips competitive primarily through district heating of municipal centres. When compared with the conventional heating mode the reliability of chip delivery and the remuneration paid to the co-operative for attending to the running of the heating centres are considered to be the competitive advantages. The system has proven to be a working one; one indication of this is its growing application in the country. In the spring of the year 2000 there were 26 chip-based energy co-operative active in Finland. The first time that the use of bioenergy underwent a powerful rise was in the 1970s as a consequence of the oilcrises. Subsequently the enthusiasm shown to this energy form subsided. Then in the early 1990s, biofuels once again became a subject of interest mainly due to environmental issues, the restructuring of rural areas and silvicultural reasons. With the past decades' experiences forming the basis, the development needs associated with the use of bioenergy were in fresh memory and they were addressed on a wide font. Boiler technology related to solid fuels evolved rapidly and the least successful manufacturers had been eliminated by the recession. In the case of co-operative heating entrepreneurship, the commonest form neither the district heating centre nor the system of heat-transfer pipes belong to co-operative society. The co-operative is responsible only for the delivery of the fuel and for looking after the heating plant. Remuneration is generally based on the amount of energy leaving the district heating plant. Thus the heat dissipated at the heating plant is the co-operative's problem and the heat dissipated during transfer are the energy buyer's problem. The investor in the equipments usually the local municipality or an energy utility. In some cases the co-operative owns the equipments well, in which case it is correct to speak of

International relations and co-operation

International Nuclear Information System (INIS)

2002-01-01

This bulletin contains information about activities of the Nuclear Regulatory Authority of the Slovak Republic (UJD). In this leaflet the international relations and co-operation of the UJD are presented. International community is aware of the fact that nuclear energy shall be used exclusively for peaceful purposes and on condition of high standard of nuclear safety. Therefore, the long-term aim of UJD in the area of international relations is to maintain and develop internationally recognised system of state supervision upon the peaceful use of nuclear energy and to reach internationally accepted level of nuclear safety in the Slovak Republic. There are many important international treaties (Treaty on the Non-proliferation of Nuclear Weapons Convention on Nuclear Safety, etc.) to which slovakia is a party. In order to meet the obligations of these treaties UJD has the main aim for contribute to the process of international disarmament, and to a mutually advantageous co-operation. By means of the most important international organisations (e.g. International Atomic Energy Agency) the Slovak Republic actively participates in the international co-operation. Under the leadership of UJD, Slovak institutions participate in many projects and activities which have the aim to improve the safety of nuclear international obligations. In addition, UJD actively participates in the integration process of the Slovak Republic into European and Trans-Atlantic structures. Since 1993 the co-operation with the European Commission and the Nuclear Energy Agency of Organisation for Economic Co-operation and development (OECD/NEA) has been successfully implemented. Besides multilateral co-operation UJD attaches extraordinary importance to bilateral co-operation, in particular with neighbouring countries. Regular meetings of senior Slovak experts with foreign experts are organised, with the aim to exchange the newest experiences and information on peaceful use of nuclear energy. Also in

Roles of Neuroglobin Binding to Mitochondrial Complex III Subunit Cytochrome c1 in Oxygen-Glucose Deprivation-Induced Neurotoxicity in Primary Neurons.

Science.gov (United States)

Yu, Zhanyang; Zhang, Yu; Liu, Ning; Yuan, Jing; Lin, Li; Zhuge, Qichuan; Xiao, Jian; Wang, Xiaoying

2016-07-01

Neuroglobin (Ngb) is a tissue globin specifically expressed in brain neurons. Recent studies by our laboratory and others have demonstrated that Ngb is protective against stroke and related neurological disorders, but the mechanisms remain poorly understood. We previously identified cytochrome c1 (Cyc1) as an Ngb-interacting molecule by yeast two-hybrid screening. Cyc1 is a subunit of mitochondria complex III, which is a component of mitochondrial respiratory chain and a major source of reactive oxygen species (ROS) production under both physiological and pathological conditions. In this study, we for the first time defined Ngb-Cyc1 binding, and investigated its roles in oxygen-glucose deprivation (OGD)/reoxygenation-induced neurotoxicity and ROS production in primary neurons. Immunocytochemistry and co-immunoprecipitation validated Ngb-Cyc1 binding, which was significantly increased by OGD and Ngb overexpression. We found 4 h OGD with/without 4 h reoxygenation significantly increased complex III activity, but this activity elevation was significantly attenuated in three groups of neurons: Ngb overexpression, specific complex III inhibitor stigmatellin, or stigmatellin plus Ngb overexpression, whereas there was no significant differences between these three groups, suggesting Ngb-Cyc1 binding may function in suppressing OGD-mediated complex III activity elevation. Importantly, these three groups of neurons also showed significant decreases in OGD-induced superoxide anion generation and neurotoxicity. These results suggest that Ngb can bind to mitochondrial complex III subunit Cyc1, leading to suppression of OGD-mediated complex III activity and subsequent ROS production elevation, and eventually reduction of OGD-induced neurotoxicity. This molecular signaling cascade may be at least part of the mechanisms of Ngb neuroprotection against OGD-induced neurotoxicity.

Electrocatalytic behavior of thin Co-Te-O films in oxygen evolution and reduction reactions

International Nuclear Information System (INIS)

Rashkova, V.; Kitova, S.; Vitanov, T.

2007-01-01

Co-Te-O catalytic films, obtain by vacuum co-evaporation of Co and TeO 2 are investigated as electrocatalysts for oxygen reactions in alkaline media. Bifunctional gas-diffusion oxygen electrodes (gde) are prepared by direct deposition of catalyst films on gas-diffusion membranes (gdm) consisting of hydrophobized carbon blacks or hydrophobized 'Ebonex' (suboxides of titanium dioxide). Thus obtained electrodes with different atomic ratio R Co/Te of the catalyst, treated at different temperatures were electrochemically tested by means of cyclic voltammetry and steady-state voltammetry. It is shown that the electrodes exhibit high catalytic activity toward oxygen evolution and reduction reaction despite very low catalyst loading of about 0.05-0.5 mg cm -2

Binding of AR to SMRT/N-CoR complex and its co-operation with PSA promoter in prostate cancer cells treated with natural histone deacetylase inhibitor NaB

Czech Academy of Sciences Publication Activity Database

Trtková, K.; Pašková, L.; Matijescuková, N.; Strnad, Miroslav

2010-01-01

Roč. 57, č. 5 (2010), s. 406-414 ISSN 0028-2685 Institutional research plan: CEZ:AV0Z50380511 Keywords : Binding * SMRT/N-CoR * complex Subject RIV: FD - Oncology ; Hematology Impact factor: 1.449, year: 2010

Oxygen isotopic signature of CO2 from combustion processes

Directory of Open Access Journals (Sweden)

W. A. Brand

2011-02-01

Full Text Available For a comprehensive understanding of the global carbon cycle precise knowledge of all processes is necessary. Stable isotope (13C and 18O abundances provide information for the qualification and the quantification of the diverse source and sink processes. This study focuses on the δ18O signature of CO2 from combustion processes, which are widely present both naturally (wild fires, and human induced (fossil fuel combustion, biomass burning in the carbon cycle. All these combustion processes use atmospheric oxygen, of which the isotopic signature is assumed to be constant with time throughout the whole atmosphere. The combustion is generally presumed to take place at high temperatures, thus minimizing isotopic fractionation. Therefore it is generally supposed that the 18O signature of the produced CO2 is equal to that of the atmospheric oxygen. This study, however, reveals that the situation is much more complicated and that important fractionation effects do occur. From laboratory studies fractionation effects on the order of up to 26%permil; became obvious in the derived CO2 from combustion of different kinds of material, a clear differentiation of about 7‰ was also found in car exhausts which were sampled directly under ambient atmospheric conditions. We investigated a wide range of materials (both different raw materials and similar materials with different inherent 18O signature, sample geometries (e.g. texture and surface-volume ratios and combustion circumstances. We found that the main factor influencing the specific isotopic signatures of the combustion-derived CO2 and of the concomitantly released oxygen-containing side products, is the case-specific rate of combustion. This points firmly into the direction of (diffusive transport of oxygen to the reaction zone as the cause of the isotope fractionation. The original total 18O signature of the material appeared to have little influence, however, a contribution of specific bio

CO2 maximum in the oxygen minimum zone (OMZ)

OpenAIRE

Paulmier, Aurélien; Ruiz-Pino, D.; Garcon, V.

2011-01-01

International audience; Oxygen minimum zones (OMZs), known as suboxic layers which are mainly localized in the Eastern Boundary Upwelling Systems, have been expanding since the 20th "high CO2" century, probably due to global warming. OMZs are also known to significantly contribute to the oceanic production of N2O, a greenhouse gas (GHG) more efficient than CO2. However, the contribution of the OMZs on the oceanic sources and sinks budget of CO2, the main GHG, still remains to be established. ...

Co@Co3O4 nanoparticle embedded nitrogen-doped carbon architectures as efficient bicatalysts for oxygen reduction and evolution reactions

Science.gov (United States)

Qi, Chunling; Zhang, Li; Xu, Guancheng; Sun, Zhipeng; Zhao, Aihua; Jia, Dianzeng

2018-01-01

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play crucial roles in efficient energy conversion and storage solutions. Here, Co@Co3O4 nanoparticle embedded nitrogen-doped carbon architectures (denoted as Co@Co3O4/NCs) are prepared via a simple two-step and in situ approach by carbonization and subsequent oxidation of Co-MOF containing high contents of carbon and nitrogen. When evaluated as electrocatalyst towards both ORR and OER in a KOH electrolyte solution, the as-fabricated Co@Co3O4/NC-2 exhibits similar ORR catalytic activity to the commercial Pt/C catalyst, but superior stability and good methanol tolerance. Furthermore, the as-fabricated catalysts also show promising catalytic activity for OER. The effective catalytic activities originate from the synergistic effects between well wrapped Co@Co3O4 nanoparticles and nitrogen doped carbon structures.

Acyl-CoA binding proteins; structural and functional conservation over 2000 MYA

DEFF Research Database (Denmark)

Faergeman, Nils J; Wadum, Majken; Feddersen, Søren

2007-01-01

-CoA binding protein, ACBP, has been proposed to play a pivotal role in the intracellular trafficking and utilization of long-chain fatty acyl-CoA esters. Depletion of acyl-CoA binding protein in yeast results in aberrant organelle morphology incl. fragmented vacuoles, multi-layered plasma membranes...... and accumulation of vesicles of variable sizes. In contrast to synthesis and turn-over of glycerolipids, the levels of very-long-chain fatty acids, long-chain bases and ceramide are severely affected by Acb1p depletion, suggesting that Acb1p, rather than playing a general role, serves specific roles in cellular...

Upcrowding energy co-operatives - Evaluating the potential of crowdfunding for business model innovation of energy co-operatives.

Science.gov (United States)

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.

Oxygen, hydrogen, ethylene and CO 2 development in lithium-ion batteries

Science.gov (United States)

Holzapfel, M.; Würsig, A.; Scheifele, W.; Vetter, J.; Novák, P.

Gas evolution has been examined for different types of battery-related electrode materials via in situ differential electrochemical mass spectrometry (DEMS). Besides standard graphite also a novel silicon-based negative electrode was examined and it was shown that the evolution of hydrogen and ethylene is considerably reduced on this material compared to graphite. Oxygen evolution was proven to happen on the oxidative reaction of a Li 2O 2 electrode, besides a certain oxidation of the electrolyte. The 4.5 V plateau upon the oxidation of Li[Ni 0.2Li 0.2Mn 0.6]O 2 was likewise proven to be linked to oxygen evolution. Also in this case electrolyte oxidation was shown to be a side reaction. Layered positive electrode materials Li(Ni,Co,Al)O 2 and Li(Ni,Mn,Co)O 2 were also examined. The influence of different parameters on the CO 2 evolution in lithium-ion batteries was shown up. The amount of CO 2 formation is increased by high temperatures and cell voltages, while the addition of vinylene carbonate (VC) decreases it. Li(Ni,Mn,Co)O 2 shows much less CO 2 evolution than Li(Ni,Co,Al)O 2.

Non-self-sustained electric discharge in oxygen gas mixtures: singlet delta oxygen production

CERN Document Server

Ionin, A A; Kotkov, A A; Kochetov, I V; Napartovich, A P; Seleznev, L V; Sinitsyn, D V; Hager, G D

2003-01-01

The possibility of obtaining a high specific input energy in an electron-beam sustained discharge ignited in oxygen gas mixtures O sub 2 : Ar : CO (or H sub 2) at the total gas pressures of 10-100 Torr was experimentally demonstrated. The specific input energy per molecular component exceeded approx 6 kJ l sup - sup 1 atm sup - sup 1 (150 kJ mol sup - sup 1) as a small amount of carbon monoxide was added into a gas mixture of oxygen and argon. It was theoretically demonstrated that one might expect to obtain a singlet delta oxygen yield of 25% exceeding its threshold value needed for an oxygen-iodine laser operation at room temperature, when maintaining a non-self-sustained discharge in oxygen gas mixtures with molecular additives CO, H sub 2 or D sub 2. The efficiency of singlet delta oxygen production can be as high as 40%.

Co-operatives and Normative Control

DEFF Research Database (Denmark)

Bregn, Kirsten; Jagd, Søren

1992-01-01

This paper explores the conditions for applying normative control in co-operatives. For normative control to be effective two conditions are found particularly important: Individuals must be morally involved and the organization must have a system of making it possible to link common norms...... and individual action. If these conditions are not fulfilled, as may be the case in many co-operatives, normative control cannot be expected to work. The problems of normative control in co-operatives may then not be caused by the use of normative control as such, but may instead be a problem of securing...

Oxygen relieves the CO2 and acetate dependency of Lactobacillus johnsonii NCC 533

NARCIS (Netherlands)

Hertzberger, R.Y.; Pridmore, R.D.; Gysler, C.; Kleerebezem, M.; Teixeira de Mattos, M.J.

2013-01-01

Oxygen relieves the CO2 and acetate dependency of Lactobacillus johnsonii NCC 533. The probiotic Lactobacillus johnsonii NCC 533 is relatively sensitive to oxidative stress; the presence of oxygen causes a lower biomass yield due to early growth stagnation. We show however that oxygen can also be

Oxygen Toxicity and Special Operations Forces Diving: Hidden and Dangerous

Directory of Open Access Journals (Sweden)

Thijs T. Wingelaar

2017-07-01

Full Text Available In Special Operations Forces (SOF closed-circuit rebreathers with 100% oxygen are commonly utilized for covert diving operations. Exposure to high partial pressures of oxygen (PO2 could cause damage to the central nervous system (CNS and pulmonary system. Longer exposure time and higher PO2 leads to faster development of more serious pathology. Exposure to a PO2 above 1.4 ATA can cause CNS toxicity, leading to a wide range of neurologic complaints including convulsions. Pulmonary oxygen toxicity develops over time when exposed to a PO2 above 0.5 ATA and can lead to inflammation and fibrosis of lung tissue. Oxygen can also be toxic for the ocular system and may have systemic effects on the inflammatory system. Moreover, some of the effects of oxygen toxicity are irreversible. This paper describes the pathophysiology, epidemiology, signs and symptoms, risk factors and prediction models of oxygen toxicity, and their limitations on SOF diving.

The role of Co impurities and oxygen vacancies in the ferromagnetism of Co-doped SnO2: GGA and GGA+U studies

International Nuclear Information System (INIS)

Wang Hongxia; Yan Yu; Mohammed, Y. Sh.; Du Xiaobo; Li Kai; Jin Hanmin

2009-01-01

The electronic structure and ferromagnetic stability of Co-doped SnO 2 are studied using the first-principle density functional method within the generalized gradient approximation (GGA) and GGA+U schemes. The addition of effective U Co transforms the ground state of Co-doped SnO 2 to insulating from half-metallic and the coupling between the nearest neighbor Co spins to weak antimagnetic from strong ferromagnetic. GGA+U Co calculations show that the pure substitutional Co defects in SnO 2 cannot induce the ferromagnetism. Oxygen vacancies tend to locate near Co atoms. Their presence increases the magnetic moment of Co and induces the ferromagnetic coupling between two Co spins with large Co-Co distance. The calculated density of state and spin density distribution calculated by GGA+U Co show that the long-range ferromagnetic coupling between two Co spins is mediated by spin-split impurity band induced by oxygen vacancies. More charge transfer from impurity to Co-3d states and larger spin split of Co-3d and impurity states induced by the addition of U Co enhance the ferromagnetic stability of the system with oxygen vacancies. By applying a Coulomb U O on O 2 s orbital, the band gap is corrected for all calculations and the conclusions derived from GGA+U Co calculations are not changed by the correction of band gap.

Co-operation and Self-Organization

Directory of Open Access Journals (Sweden)

Christian Fuchs

2008-07-01

Full Text Available Co-operation has its specific meanings in physical (dissipative, biological (autopoietic and social (re-creative systems. On upper hierarchical systemic levels there are additional, emergent properties of co-operation, co-operation evolves dialectically. The focus of this paper is human cooperation. Social systems permanently reproduce themselves in a loop that mutually connects social structures and actors. Social structures enable and constrain actions, they are medium and outcome of social actions. This reflexive process is termed re-creation and describes the process of social selforganization. Co-operation in a very weak sense means coaction and takes place permanently in re-creative systems: two or more actors act together in a co-ordinated manner so that a new emergent property emerges. Co-action involves the formation of forces, environment and sense (dispositions, decisions, definitions. Mechanistic approaches conceive coaction in terms of rational planning, consciousness, intention, predictability, and necessity. Holistic approaches conceive coaction in terms of spontaneity, unconscious and unintended actions, non-predictability, chance. Dialectic approaches conceive co-action in terms of a unity of rational planning and spontaneous emergence, a unity of conscious and unconscious aspects and consequences, and a unity of necessity and chance. Co-operation in a strong sense that is employed in this paper means that actors work together, create a new emergent reality, have shared goals, all benefit from co-operating, can reach their goals in joint effort more quickly and more efficiently than on an individual basis, make concerted use of existing structures in order to produce new structures, learn from each other mutually, are interconnected in a social network, and are mutually dependent and responsible. There is a lack of cooperation, self-determination, inclusion and direct democracy in modern society due to its antagonistic

Co-operatives in the Cultural Industries

Directory of Open Access Journals (Sweden)

Marisol Sandoval

2015-04-01

The roundtable discussed the potentials and limits of worker co-operatives as an alternative way of organizing cultural work. It explored how worker co-operation might contribute to new collaborative forms of cultural production; how they do, or might, strengthen a 'cultural commons'; and the role cultural co-ops play in the wider context of movements for workers' rights. Questions that were discussed include: To what extent can worker co-operatives be a means to confront precariousness and individualisation in work in the cultural sector? Do worker co-ops open up new possibilities for the collaborative production of cultural commons? What role can worker co-operatives play within a broader movement for creating more just, equal and humane cultural work and an alternative to capitalist economies? Where lies the boundary between neoliberal calls for self-help and individual responsibility and a radical co-op movement? What is the relation between worker co-ops and other forms of progressive politics such as the union movements, social protests and civil society activism? Can cultural co-ops contribute to reinventing the meaning and practice of work in the 21st century? About the speakers: Marisol Sandoval is a Lecturer at the Department of Culture and Creative Industries at City University London. Her research critically deals with questions of power, responsibility, commodification, exploitation, ideology and resistance in the global culture industry. Jo Littler is Senior Lecturer at City University London's Department of Culture and Creative Industries. Her work explores questions of culture and power from an interdisciplinary, cultural studies-informed perspective. Rhiannon Colvin after graduating in 2010 to find the world of work competitive and brutal, Rhiannon founded AltGen to empower young graduates to get together and create their own work. http://www.altgen.org.uk/ Tara Mulqueen is a PhD candidate at Birkbeck College School of Law. Her thesis concerns the

Stepwise dehydrogenation of ammonia on Fcc-Co surfaces: A DFT study

Energy Technology Data Exchange (ETDEWEB)

Ma, F.F.; Ma, S.H., E-mail: mash.phy@htu.edu.cn; Jiao, Z.Y.; Dai, X.Q.

2017-05-31

Highlights: • On Co surfaces, oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation on the Co surfaces. • Pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. • The dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces. • The species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom. - Abstract: The stepwise dehydrogenation of ammonia on clean and O-covered Co surfaces have been studied by performing density functional theory (DFT) calculations. It is found that the interaction of species NH{sub x} (x = 0–3) with the Co surfaces become stronger with its further dehydrogenation, and oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation. Specifically, pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. In contrast, the dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces, due to the high energy barriers. And present results demonstrate that the species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom.

Stepwise dehydrogenation of ammonia on Fcc-Co surfaces: A DFT study

International Nuclear Information System (INIS)

Ma, F.F.; Ma, S.H.; Jiao, Z.Y.; Dai, X.Q.

2017-01-01

Highlights: • On Co surfaces, oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation on the Co surfaces. • Pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. • The dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces. • The species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom. - Abstract: The stepwise dehydrogenation of ammonia on clean and O-covered Co surfaces have been studied by performing density functional theory (DFT) calculations. It is found that the interaction of species NH x (x = 0–3) with the Co surfaces become stronger with its further dehydrogenation, and oxygen atom not only strengthens ammonia-substrate interaction but also facilitates ammonia dissociation. Specifically, pre-adsorbed O atom significantly promotes the stepwise dehydrogenation of ammonia on Co(110), giving rise to N atom strongly binding with the surface. In contrast, the dissociation of NH appears to be the rate-determining step on O-covered Co(111) and Co(100) surfaces, due to the high energy barriers. And present results demonstrate that the species N and NH produced in ammonia dehydrogenation are likely responsible for cobalt catalyst deactivation in the excess of oxygen atom.

Intra-operative tissue oxygen tension is increased by local insufflation of humidified-warm CO2 during open abdominal surgery in a rat model.

Directory of Open Access Journals (Sweden)

Jean K Marshall

Full Text Available Maintenance of high tissue oxygenation (PtO2 is recommended during surgery because PtO2 is highly predictive of surgical site infection and colonic anastomotic leakage. However, surgical site perfusion is often sub-optimal, creating an obstructive hurdle for traditional, systemically applied therapies to maintain or increase surgical site PtO2. This research tested the hypothesis that insufflation of humidified-warm CO2 into the abdominal cavity would increase sub-peritoneal PtO2 during open abdominal surgery.15 Wistar rats underwent laparotomy under general anesthesia. Three sets of randomized cross-over experiments were conducted in which the abdominal cavity was subjected to alternating exposure to 1 humidified-warm CO2 & ambient air; 2 humidified-warm CO2 & dry-cold CO2; and 3 dry-cold CO2 & ambient air. Sub-peritoneal PtO2 and tissue temperature were measured with a polarographic oxygen probe.Upon insufflation of humidified-warm CO2, PtO2 increased by 29.8 mmHg (SD 13.3; p<0.001, or 96.6% (SD 51.9, and tissue temperature by 3.0°C (SD 1.7 p<0.001, in comparison with exposure to ambient air. Smaller, but significant, increases in PtO2 were seen in experiments 2 and 3. Tissue temperature decreased upon exposure to dry-cold CO2 compared with ambient air (-1.4°C, SD 0.5, p = 0.001.In a rat model, insufflation of humidified-warm CO2 into the abdominal cavity during open abdominal surgery causes an immediate and potentially clinically significant increase in PtO2. The effect is an additive result of the delivery of CO2 and avoidance of evaporative cooling via the delivery of the CO2 gas humidified at body temperature.

Safety Standard for Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation

Science.gov (United States)

1996-01-01

NASA's standard for oxygen system design, materials selection, operation, and transportation is presented. Minimum guidelines applicable to NASA Headquarters and all NASA Field Installations are contained.

Identification of residues on human receptor DPP4 critical for MERS-CoV binding and entry

Energy Technology Data Exchange (ETDEWEB)

Song, Wenfei [Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Wang, Ying [Comprehensive AIDS Research Center, Research Center for Public Health, School of Medicine, Tsinghua University, Beijing 100084 (China); Wang, Nianshuang; Wang, Dongli [Ministry of Education Key Laboratory of Protein Science, Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084 (China); Guo, Jianying; Fu, Lili [Comprehensive AIDS Research Center, Research Center for Public Health, School of Medicine, Tsinghua University, Beijing 100084 (China); Shi, Xuanling, E-mail: shixuanlingsk@tsinghua.edu.cn [Comprehensive AIDS Research Center, Research Center for Public Health, School of Medicine, Tsinghua University, Beijing 100084 (China)

2014-12-15

Middle East respiratory syndrome coronavirus (MERS-CoV) infects host cells through binding the receptor binding domain (RBD) on its spike glycoprotein to human receptor dipeptidyl peptidase 4 (hDPP4). Here, we report identification of critical residues on hDPP4 for RBD binding and virus entry through analysis of a panel of hDPP4 mutants. Based on the RBD–hDPP4 crystal structure we reported, the mutated residues were located at the interface between RBD and hDPP4, which potentially changed the polarity, hydrophobic or hydrophilic properties of hDPP4, thereby interfering or disrupting their interaction with RBD. Using surface plasmon resonance (SPR) binding analysis and pseudovirus infection assay, we showed that several residues in hDPP4–RBD binding interface were important on hDPP4–RBD binding and viral entry. These results provide atomic insights into the features of interactions between hDPP4 and MERS-CoV RBD, and also provide potential explanation for cellular and species tropism of MERS-CoV infection. - Highlights: • It has been demonstrated that MERS-CoV infects host cells through binding its envelope spike (S) glycoprotein to the host cellular receptor dipeptidyl peptidase 4 (DPP4). • To identify the critical residues on hDPP4 for RBD binding and virus entry, we constructed a panel of hDPP4 mutants based on structure-guided mutagenesis. • Using surface plasmon resonance (SPR) binding analysis and pseudovirus infection assay, we showed that several residues on hDPP4 had significant impacts on virus/receptor interactions and viral entry. • Our study has provided new insights into the features of interactions between hDPP4 and MERS-CoV RBD, and provides potential explanation for cellular and species tropism of MERS-CoV infection.

Oxygen binding properties, capillary densities and heart weights in high altitude camelids.

Science.gov (United States)

Jürgens, K D; Pietschmann, M; Yamaguchi, K; Kleinschmidt, T

1988-01-01

The oxygen binding properties of the blood of the camelid species vicuna, llama, alpaca and dromedary camel were measured and evaluated with respect to interspecific differences. The highest blood oxygen affinity, not only among camelids but of all mammals investigated so far, was found in the vicuna (P50 = 17.6 Torr compared to 20.3-21.6 Torr in the other species). Low hematocrits (23-34%) and small red blood cells (21-30 microns 3) are common features of all camelids, but the lowest values are found in the Lama species. Capillary densities were determined in heart and soleus muscle of vicuna and llama. Again, the vicuna shows exceptional values (3720 cap/mm2 on average in the heart) for a mammal of this body size. Finally, heart weight as percent of body weight is higher in the vicuna (0.7-0.9%) than in the other camelids studied (0.5-0.7%). The possibility that these parameters, measured in New World tylopodes at sea level, are not likely to change considerably with transfer to high altitude, is discussed. In the vicuna, a unique combination of the following features seems to be responsible for an outstanding physical capability at high altitude: saturation of blood with oxygen in the lung is favored by a high blood oxygen affinity, oxygen supply being facilitated by low diffusion distances in the muscle tissue. Loading, as well as unloading, of oxygen is improved by a relatively high oxygen transfer conductance of the red blood cells, which is due to their small size and which compensates the negative effect of a low hematocrit on the oxygen conductance of blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term operation of oxygen-limiting membrane bioreactor (MBR) for the development of simultaneous partial nitrification, anammox and denitrification (SNAD) process.

Science.gov (United States)

Zhao, Chuanqi; Wang, Gang; Xu, Xiaochen; Yang, Yuesuo; Yang, Fenglin

2017-07-18

In this study, an oxygen-limiting membrane bioreactor (MBR) with recirculation of biogas for relieving membrane fouling was successfully operated to realize the simultaneous partial nitrification, anammox and denitrification (SNAD) process. The MBR operation was considered effective in the long-term test with total nitrogen (TN) and chemical oxygen demand (COD) removal efficiencies of 94.86% and 98.91%, respectively. Membrane fouling was significantly alleviated due to the recirculation of biogas and the membrane had been cleaned four times with a normal filtration period of 52 days. The co-existence of ammonia-oxidizing bacteria (AOB), anammox and denitrifying bacteria in MBR was confirmed by scanning electron microscopy (SEM) and fluorescence in situ hybridizations (FISH) analysis. Furthermore, AOB were found close to the granule surface, while denitrifying bacteria and anammox were in the deeper layer of granules. Potential in excellent TN and COD removal, operational stability and sustainability, as well as in alleviating membrane fouling is expected by using this oxygen-limiting MBR.

Romanian-Danish Environmental Co-operation. Co-operation development 1993-1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-08-01

The Danish Ministry of Environment and Energy has, since 1991, through the Danish Environmental Support Fund, contributed towards protecting the environment and nature in Central and Eastern European countries and has helped to limit regional as well as global pollution. The Romanian Ministry of Waters, Forests and Environmental Protection and the Danish Ministry of Environment and Energy initiated the co-operation in 1993 and an official Agreement was signed in 1994. This publication describes the co-operation between the two countries in the field of the environment in the hope that this will give both the general public of Romania and the international community a better understanding of the work being accomplished. It also gives an overview of the 19 projects developed within this framework, which has a total Danish grant of DKK 77.9 million. (au)

MOF derived Ni/Co/NC catalysts with enhanced properties for oxygen evolution reaction

Science.gov (United States)

Hu, Jiapeng; Chen, Juan; Lin, Hao; Liu, Ruilai; Yang, Xiaobing

2018-03-01

Designing efficient electrocatalysts for oxygen evolution reaction (OER) is very important for renewable energy storage and conversion devices. In this paper, we introduced a new strategy to synthesize Ni doped Co/NC catalysts (NC is the abbreviation of nitrogen-doped graphitic carbon), which were derived from ZIF-67. All catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and oxygen evolution reaction (OER). The results show that Ni was well doped in the Ni/Co/NC catalysts and the doping of Ni has great influence on the OER activity of Ni/Co/NC catalysts. Among these catalysts, 0.50Ni/Co/NC exhibits the highest OER activity. The onset potential of 0.50Ni/Co/NC is 1.47 V, which is superior than the onset potential of Co/NC (1.54 V), 0.25Ni/Co/NC (1.48 V), 1.00Ni/Co/NC (1.53 V). The excellent OER activity of 0.50Ni/Co/NC catalyst makes its potential to be used on renewable energy storage.

Pulse height measurements and electron attachment in drift chambers operated with Xe,CO2 mixtures

CERN Document Server

Andronic, A

2003-01-01

We present pulse height measurements in drift chambers operated with Xe,CO2 gas mixtures. We investigate the attachment of primary electrons on oxygen and SF6 contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and Fe55 pulse height measurements using monitor detectors.

Pulse height measurements and electron attachment in drift chambers operated with Xe,CO2 mixtures

International Nuclear Information System (INIS)

Andronic, A.; Appelshaeuser, H.; Blume, C.; Braun-Munzinger, P.; Bucher, D.; Busch, O.; Ramirez, A.C.A. Castillo; Catanescu, V.; Ciobanu, M.; Daues, H.; Devismes, A.; Emschermann, D.; Fateev, O.; Garabatos, C.; Herrmann, N.; Ivanov, M.; Mahmoud, T.; Peitzmann, T.; Petracek, V.; Petrovici, M.; Reygers, K.; Sann, H.; Santo, R.; Schicker, R.; Sedykh, S.; Shimansky, S.; Simon, R.S.; Smykov, L.; Soltveit, H.K.; Stachel, J.; Stelzer, H.; Tsiledakis, G.; Vulpescu, B.; Wessels, J.P.; Windelband, B.; Winkelmann, O.; Xu, C.; Zaudtke, O.; Zanevsky, Yu.; Yurevich, V.

2003-01-01

We present pulse height measurements in drift chambers operated with Xe,CO 2 gas mixtures. We investigate the attachment of primary electrons on oxygen and SF 6 contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and 55 Fe pulse height measurements using monitor detectors

Determination of oxygen nonstoichiometry and diffusivity in mixed conducting oxides by oxygen Coulometric titration. II. Oxygen nonstoichiometry and defect model for La0.8Sr0.2CoO3-d

NARCIS (Netherlands)

Lankhorst, M.H.R.; Lankhorst, M.H.R.; Bouwmeester, Henricus J.M.

1997-01-01

The oxygen nonstoichiometry of La0.8Sr0.2CoO3-delta has been determined as a function of oxygen partial pressure and temperature using a high-temperature coulometric titration cell. For each measured value of the oxygen chemical potential, the oxygen nonstoichiometry is found to be nearly

Oxygen isotope fractionation in the CaCO3-DIC-H2O system

Science.gov (United States)

Devriendt, Laurent S.; Watkins, James M.; McGregor, Helen V.

2017-10-01

The oxygen isotope ratio (δ18O) of inorganic and biogenic carbonates is widely used to reconstruct past environments. However, the oxygen isotope exchange between CaCO3 and H2O rarely reaches equilibrium and kinetic isotope effects (KIE) commonly complicate paleoclimate reconstructions. We present a comprehensive model of kinetic and equilibrium oxygen isotope fractionation between CaCO3 and water (αc/w) that accounts for fractionation between both (a) CaCO3 and the CO32- pool (α c / CO32-) , and (b) CO32- and water (α CO32- / w) , as a function of temperature, pH, salinity, calcite saturation state (Ω), the residence time of the dissolved inorganic carbon (DIC) in solution, and the activity of the enzyme carbonic anhydrase. The model results suggest that: (1) The equilibrium αc/w is only approached in solutions with low Ω (i.e. close to 1) and low ionic strength such as in the cave system of Devils Hole, Nevada. (2) The sensitivity of αc/w to the solution pH and/or the mineral growth rate depends on the level of isotopic equilibration between the CO32- pool and water. When the CO32- pool approaches isotopic equilibrium with water, small negative pH and/or growth rate effects on αc/w of about 1-2‰ occur where these parameters covary with Ω. In contrast, isotopic disequilibrium between CO32- and water leads to strong (>2‰) positive or negative pH and growth rate effects on α CO32-/ w (and αc/w) due to the isotopic imprint of oxygen atoms derived from HCO3-, CO2, H2O and/or OH-. (3) The temperature sensitivity of αc/w originates from the negative effect of temperature on α CO32-/ w and is expected to deviate from the commonly accepted value (-0.22 ± 0.02‰/°C between 0 and 30 °C; Kim and O'Neil, 1997) when the CO32- pool is not in isotopic equilibrium with water. (4) The model suggests that the δ18O of planktic and benthic foraminifers reflects a quantitative precipitation of DIC in isotopic equilibrium with a high-pH calcifying fluid, leading

Ignition and devolatilization of pulverized coals in lower oxygen content O{sub 2}/CO{sub 2} atmosphere

Energy Technology Data Exchange (ETDEWEB)

Huang, Xiaohong; Li, Jing; Liu, Zhaohui; Yang, Ming; Wang, Dingbang; Zheng, Chuguang [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

2013-07-01

High speed camera is employed to capture the transient images of the burning particle in a flat-flame entrained flow reactor, some information of the burning particle, such as the optical intensity and the residence time, are obtained through analysis of transient images. The ignition and devolatilization behavior of different rank coals at 1,670, 1,770 and 1,940 K over a range of 2-30% O{sub 2} in both N{sub 2} and CO{sub 2} diluent gases are researched. The results indicate that the laws of ignition and devolatilization of pulverized coals in low oxygen O{sub 2}/CO{sub 2} atmosphere are consistent with the literature, which focus on the environments of high oxygen contents (10-30%) or lower temperate (900-1,500 K). With the gas temperature and oxygen content increased, the ignition delay time and devolatilization time for the lower oxygen content cases decreased for both N{sub 2} and CO{sub 2} atmosphere. With the use CO{sub 2} in place of N{sub 2} in low oxygen content, the ignition delay was retarded and the duration of devolatilization was increased. The effect of CO{sub 2} on coal particle ignition is explained by its higher molar specific heat. And the effect of CO{sub 2} on devolatilization results from its effect on the diffusion rates of volatile fuel and oxygen.

Obstetric care: competition or co-operation.

NARCIS (Netherlands)

Veer, A.J.E. de; Meijer, W.J.

1996-01-01

OBJECTIVE: The aim of this study was to determine the feasibility of co-operation within maternity and obstetric care between midwives, general practitioners (GPs) and obstetricians. DESIGN: descriptive correlational study. SETTING: The Netherlands. Policy is towards more co-operation between

CO2 reactivity and brain oxygen pressure monitoring in severe head injury.

Science.gov (United States)

Carmona Suazo, J A; Maas, A I; van den Brink, W A; van Santbrink, H; Steyerberg, E W; Avezaat, C J

2000-09-01

To investigate the effect of hyperventilation on cerebral oxygenation after severe head injury. A prospective, observational study. Neurointensive care unit at a university hospital. A total of 90 patients with severe head injury (Glasgow Coma Scale score brain tissue oxygen pressure (PbrO2) was performed as a measure of cerebral oxygenation. Arterial PCO2 was decreased each day over a 5-day period for 15 mins by increasing minute volume on the ventilator setting to 20% above baseline. Arterial blood gas analysis was performed before and after changing ventilator settings. Multimodality monitoring, including PbrO2, was performed in all patients. Absolute and relative PbrO2/PaCO2 reactivity was calculated. Outcome at 6 months was evaluated according to the Glasgow Outcome Scale. Effective hyperventilation, defined by a decrease of PaCO2 > or =2 torr (0.27 kPa), was obtained in 218 (84%) of 272 tests performed. Baseline PaCO2 averaged 32.3 +/- 4.5 torr (4.31 +/- 0.60 kPa). Average reduction in PaCO2 was 3.8 +/- 1.7 torr (0.51 +/- 0.23 kPa). PbrO2 decreased by 2.8 +/- 3.7 torr (0.37 +/- 0.49 kPa; p < .001) from a baseline value of 26.5 +/- 11.6 torr (3.53 +/- 1.55 kPa). PbrO2/PaCO2 reactivity was low on day 1 (0.8 +/- 2.3 torr [0.11 +/- 0.31 kPa]), increasing on subsequent days to 6.1 +/- 4.4 torr (0.81 +/- 0.59 kPa) on day 5. PbrO2/PaCO2 reactivity on days 1 and 2 was not related to outcome. In later phases in patients with unfavorable outcome, relative reactivity was increased more markedly, reaching statistical significance on day 5. Increased hyperventilation causes a significant reduction in PbrO2, providing further evidence for possible increased risk of secondary ischemic damage during hyperventilation. The low PbrO2/PaCO2 reactivity on day 1 indicates the decreased responsiveness of cerebral microvascular vessels to PaCO2 changes, caused by generalized vascular narrowing. The increasing PbrO2/PaCO2 reactivity from days 2 to 5 suggests that the risk of

Costs and benefits of lunar oxygen: Engineering, operations, and economics

Science.gov (United States)

Sherwood, Brent; Woodcock, Gordon R.

1991-01-01

Oxygen is the most commonly discussed lunar resource. It will certainly not be the easiest to retrieve, but oxygen's fundamental place in propulsion and life support guarantees it continued attention as a prime candidate for early in situ resource utilization (ISRU). The findings are reviewed of recent investigation, sponsored by NASA-Ames, into the kinds of technologies, equipment, and scenarios (the engineering and operations costs) that will be required even to initiate lunar oxygen production. The infrastructure necessary to surround and support a viable oxygen-processing operation is explained. Selected details are used to illustrate the depth of technology challenges, extent of operations burdens, and complexity of decision linkages. Basic assumptions, and resulting timelines and mass manifests, are listed. These findings are combined with state-of-the-art knowledge of lunar and Mars propulsion options in simple economic input/output and internal-rate-of-return models, to compare production costs with performance benefits. Implications for three realistic scales of exploration architecture - expeditionary, aggressive science, and industrialization/settlement - are discussed. Conclusions are reached regarding the contextual conditions within which production of lunar oxygen (LLOX) is a reasonable activity. LLOX appears less useful for Mars missions than previously hoped. Its economical use in low Earth orbit hinges on production of lunar hydrogen as well. LLOX shows promise for lunar ascent/descent use, but that depends strongly on the plant mass required.

Differential Binding of Co(II) and Zn(II) to Metallo-beta-Lactamase Bla2 from Bacillus anthracis

Energy Technology Data Exchange (ETDEWEB)

Hawk, M.; Breece, R; Hajdin, C; Bender, K; Hu, Z; Costello, A; Bennett, B; Tierney, D; Crowder, M

2009-01-01

In an effort to probe the structure, mechanism, and biochemical properties of metallo-{beta}-lactamase Bla2 from Bacillus anthracis, the enzyme was overexpressed, purified, and characterized. Metal analyses demonstrated that recombinant Bla2 tightly binds 1 equiv of Zn(II). Steady-state kinetic studies showed that mono-Zn(II) Bla2 (1Zn-Bla2) is active, while di-Zn(II) Bla2 (ZnZn-Bla2) was unstable. Catalytically, 1Zn-Bla2 behaves like the related enzymes CcrA and L1. In contrast, di-Co(II) Bla2 (CoCo-Bla2) is substantially more active than the mono-Co(II) analogue. Rapid kinetics and UV-vis, 1H NMR, EPR, and EXAFS spectroscopic studies show that Co(II) binding to Bla2 is distributed, while EXAFS shows that Zn(II) binding is sequential. To our knowledge, this is the first documented example of a Zn enzyme that binds Co(II) and Zn(II) via distinct mechanisms, underscoring the need to demonstrate transferability when extrapolating results on Co(II)-substituted proteins to the native Zn(II)-containing forms.

Surface coverage of Pt atoms on PtCo nanoparticles and catalytic kinetics for oxygen reduction

Energy Technology Data Exchange (ETDEWEB)

Jiang Rongzhong, E-mail: rongzhong.jiang@us.army.mi [Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783-1197 (United States); Rong, Charles; Chu, Deryn [Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783-1197 (United States)

2011-02-01

The surface coverage of Pt atoms on PtCo nanoparticles and its effect on catalytic kinetics for oxygen reduction were investigated. The PtCo nanoparticles with different surface coverage of Pt atoms were synthesized with various methods, including normal chemical method, microemulsion synthesis, and ultrasound-assisted microemulsion. A model of Pt atoms filling into a spherical nanoparticle was proposed to explain the relationship of surface metal atoms and nanoparticle size. The catalytic activity of the PtCo nano-particles is highly dependent on the synthetic methods, even if they have the same chemical composition. The PtCo nano-particles synthesized with ultrasound-assisted microemulsion showed the highest activity, which is attributed to an increase of active surface coverage of Pt atoms on the metal nanoparticles. The rate of oxygen reduction at 0.5 V (vs. SCE) catalyzed by the PtCo synthesized with ultrasound-assisted micro-emulsion was about four times higher than that of the PtCo synthesized with normal chemical method. As demonstrated with rotating-ring disk electrode measurement, the PtCo nano-particles can catalyze oxygen 4-electron reduction to water without intermediate H{sub 2}O{sub 2} detected.

Effects of hydration and oxygen vacancy on CO2 adsorption and activation on beta-Ga2O3(100).

Science.gov (United States)

Pan, Yun-xiang; Liu, Chang-jun; Mei, Donghai; Ge, Qingfeng

2010-04-20

The effects of hydration and oxygen vacancy on CO(2) adsorption on the beta-Ga(2)O(3)(100) surface have been studied using density functional theory slab calculations. Adsorbed CO(2) is activated on the dry perfect beta-Ga(2)O(3)(100) surface, resulting in a carbonate species. This adsorption is slightly endothermic, with an adsorption energy of 0.07 eV. Water is preferably adsorbed molecularly on the dry perfect beta-Ga(2)O(3)(100) surface with an adsorption energy of -0.56 eV, producing a hydrated perfect beta-Ga(2)O(3)(100) surface. Adsorption of CO(2) on the hydrated surface as a carbonate species is also endothermic, with an adsorption energy of 0.14 eV, indicating a slightly repulsive interaction when H(2)O and CO(2) are coadsorbed. The carbonate species on the hydrated perfect surface can be protonated by the coadsorbed H(2)O to a bicarbonate species, making the CO(2) adsorption exothermic, with an adsorption energy of -0.13 eV. The effect of defects on CO(2) adsorption and activation has been examined by creating an oxygen vacancy on the dry beta-Ga(2)O(3)(100) surface. The formation of an oxygen vacancy is endothermic, by 0.34 eV, with respect to a free O(2) molecule in the gas phase. Presence of the oxygen vacancy promoted the adsorption and activation of CO(2). In the most stable CO(2) adsorption configuration on the dry defective beta-Ga(2)O(3)(100) surface with an oxygen vacancy, one of the oxygen atoms of the adsorbed CO(2) occupies the oxygen vacancy site, and the CO(2) adsorption energy is -0.31 eV. Water favors dissociative adsorption at the oxygen vacancy site on the defective surface. This process is spontaneous, with a reaction energy of -0.62 eV. These results indicate that, when water and CO(2) are present in the adsorption system simultaneously, water will compete with CO(2) for the oxygen vacancy sites and impact CO(2) adsorption and conversion negatively.

Comparison between La_0.6Sr_0.4CoO_3-d and LaNi_0.6Co_0.4O_3-d infiltrated oxygen electrodes for long-term durable solid oxide fuel cells

DEFF Research Database (Denmark)

Ovtar, Simona; Hauch, Anne; Veltzé, Sune

2018-01-01

The degradation of infiltrated oxygen electrodes during long-term operation of solid oxide fuel cells (SOFCs) was studied. The infiltrated oxygen electrodes were prepared by infiltration of the electro-catalysts La0.6Sr0.4CoO3-d (LSC) and LaNi0.6Co0.4O3-d (LCN) into a porous yttria stabilized...... conducted and the change of resistance was followed by electrochemical impedance spectroscopy under current load. The cell performance degradation profiles of the LSC and LCN infiltrated cells showed significant differences. The performance of the LSC infiltrated cell stabilized after 700 h of operation...

Oxygen enhancement ratio (OER) to Neutron and Co-60 γ ray

International Nuclear Information System (INIS)

Kim, Mi Sook; Ji, Young Hoon; Lee, Yong Min; Kim Kyeoung Jung

1997-01-01

Experiments in vitro, using human cell lines was carried out in order to establish whether or not there was a difference between oxygen enhancement ratio (OER) of neutron and Co-60 γ-ray and to determine OER dependence on radiation dose. MG-63 cell line and H-460 cell line were defined as the most sensitive cell line to neutron among our laboratory holding cell lines through preliminary study. Anoxia as was produced in glove box. The box was flushed for one hour with a mixture of 5 % CO 2 in ultrapure N 2 (total oxygen concentration < 10 ppm) and irradiated with neutron and Co-60 γ-ray. Oxic condition was same as anoxic condition except being irradiated in general air condition. The lower OER was observed in neutron than in Co-60 γ-ray. The dose dependence of OER was observed in neutron and Co-60 γ-ray all. But the dose dependence of the OER is somewhat larger for Co-60 γ-ray than for neutron. In the range of 1 to 8 Gy, the OER for photon and neutron range from 1.54 to 1.94 and 1.23 to 1.26 in MG-63 cell line. In case of H-460 the OER for Co-60 γ-ray and neutron range from 1.24 to 1.60 and 1.06 to 1.07 respectively. (author). 19 refs., 5 tabs., 5 figs

Reversible CO binding enables tunable CO/H₂ and CO/N₂ separations in metal-organic frameworks with exposed divalent metal cations.

Science.gov (United States)

Bloch, Eric D; Hudson, Matthew R; Mason, Jarad A; Chavan, Sachin; Crocellà, Valentina; Howe, Joshua D; Lee, Kyuho; Dzubak, Allison L; Queen, Wendy L; Zadrozny, Joseph M; Geier, Stephen J; Lin, Li-Chiang; Gagliardi, Laura; Smit, Berend; Neaton, Jeffrey B; Bordiga, Silvia; Brown, Craig M; Long, Jeffrey R

2014-07-30

Six metal-organic frameworks of the M2(dobdc) (M = Mg, Mn, Fe, Co, Ni, Zn; dobdc(4-) = 2,5-dioxido-1,4-benzenedicarboxylate) structure type are demonstrated to bind carbon monoxide reversibly and at high capacity. Infrared spectra indicate that, upon coordination of CO to the divalent metal cations lining the pores within these frameworks, the C-O stretching frequency is blue-shifted, consistent with nonclassical metal-CO interactions. Structure determinations reveal M-CO distances ranging from 2.09(2) Å for M = Ni to 2.49(1) Å for M = Zn and M-C-O angles ranging from 161.2(7)° for M = Mg to 176.9(6)° for M = Fe. Electronic structure calculations employing density functional theory (DFT) resulted in good agreement with the trends apparent in the infrared spectra and crystal structures. These results represent the first crystallographically characterized magnesium and zinc carbonyl compounds and the first high-spin manganese(II), iron(II), cobalt(II), and nickel(II) carbonyl species. Adsorption isotherms indicate reversible adsorption, with capacities for the Fe, Co, and Ni frameworks approaching one CO per metal cation site at 1 bar, corresponding to loadings as high as 6.0 mmol/g and 157 cm(3)/cm(3). The six frameworks display (negative) isosteric heats of CO adsorption ranging from 52.7 to 27.2 kJ/mol along the series Ni > Co > Fe > Mg > Mn > Zn, following the Irving-Williams stability order. The reversible CO binding suggests that these frameworks may be of utility for the separation of CO from various industrial gas mixtures, including CO/H2 and CO/N2. Selectivities determined from gas adsorption isotherm data using ideal adsorbed solution theory (IAST) over a range of gas compositions at 1 bar and 298 K indicate that all six M2(dobdc) frameworks could potentially be used as solid adsorbents to replace current cryogenic distillation technologies, with the choice of M dictating adsorbent regeneration energy and the level of purity of the resulting gases.

Activities and co-operations in 1990

International Nuclear Information System (INIS)

Cai Dunjiu

1991-01-01

The items of activities and co-operations in 1990 are listed. It includes the meetings held by CNDC at home, the international meetings held in China, the international meetings, workshop or training course attended by chinese scientists and other activities and co-operations related to CNDC

International co-operation

International Nuclear Information System (INIS)

1998-01-01

A brief account of activities in international co-operation carried out by the Nuclear power plants Jaslovske Bohunice in 1997 is presented. Professionality of the Bohunice NPPs staff was highly appreciated by inviting them to be the OSART team members

Recombinant expression, purification, and characterization of an acyl-CoA binding protein from Aspergillus oryzae.

Science.gov (United States)

Hao, Qing; Liu, Xiaoguang; Zhao, Guozhong; Jiang, Lu; Li, Ming; Zeng, Bin

2016-03-01

To characterize biochemically the lipid metabolism-regulating acyl-CoA binding protein (ACBP) from the industrially-important fungus Aspergillus oryzae. A full-length cDNA encoding a candidate ACBP from A. oryzae (AoACBP) was cloned and expressed in Escherichia coli as a maltose-binding protein (MBP) fusion protein. The MBP-AoACBP protein was purified by an amylose resin chromatography column. SDS-PAGE showed that MBP-AoACBP has an estimated molecular weight of 82 kDa. Microscale thermophoresis binding assay showed that the recombinant AoACBP displayed much greater affinity for palmitoyl-CoA (K d = 80 nM) than for myristoyl-CoA (K d = 510 nM), thus demonstrating the preference of AoACBP for long-chain acyl-CoA. The data support the identification of AoACBP as a long-chain ACBP in A. oryzae.

Calcium and chemical looping technology for power generation and carbon dioxide (CO2) capture solid oxygen- and CO2-carriers

CERN Document Server

Fennell, Paul

2015-01-01

Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to chemical looping and combustion. Chapters review the market development, economics, and deployment of these systems, also providing detailed information on the variety of materials and processes that will help to shape the future of CO2 capture ready power plants. Reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to calcium and chemical loopingProvi

Hemoglobin Rahere, a human hemoglobin variant with amino acid substitution at the 2,3-diphosphoglycerate binding site. Functional consequences of the alteration and effects of bezafibrate on the oxygen bindings.

Science.gov (United States)

Sugihara, J; Imamura, T; Nagafuchi, S; Bonaventura, J; Bonaventura, C; Cashon, R

1985-09-01

We encountered an abnormal hemoglobin (Rahere), with a threonine residue replacing the beta 82 (EF6) lysine residue at the binding site of 2,3-diphosphoglycerate, which was responsible for overt erythrocytosis in two individuals of a Japanese family. Hemoglobin Rahere shows a lower oxygen affinity on the binding of 2,3-diphosphoglycerate or chloride ions than hemoglobin A. Although a decrease in the positive charge density at the binding sites of 2,3-diphosphoglycerate in hemoglobin Rahere apparently shifts the allosteric equilibrium toward the low affinity state, it greatly diminishes the cofactor effects by anions. The oxygen affinity of the patient's erythrocytes is substantially lowered by the presence of bezafibrate, which combines with sites different from those of 2,3-diphosphoglycerate in either hemoglobin Rahere or hemoglobin A.

Cross-Linked CoMoO4/rGO Nanosheets as Oxygen Reduction Catalyst

Directory of Open Access Journals (Sweden)

Jiaqi Fu

2017-12-01

Full Text Available Development of inexpensive and robust electrocatalysts towards oxygen reduction reaction (ORR is crucial for the cost-affordable manufacturing of metal-air batteries and fuel cells. Here we show that cross-linked CoMoO4 nanosheets and reduced graphene oxide (CoMoO4/rGO can be integrated in a hybrid material under one-pot hydrothermal conditions, yielding a composite material with promising catalytic activity for oxygen reduction reaction (ORR. Cyclic voltammetry (CV and linear sweep voltammetry (LSV were used to investigate the efficiency of the fabricated CoMoO4/rGO catalyst towards ORR in alkaline conditions. The CoMoO4/rGO composite revealed the main reduction peak and onset potential centered at 0.78 and 0.89 V (vs. RHE, respectively. This study shows that the CoMoO4/rGO composite is a highly promising catalyst for the ORR under alkaline conditions, and potential noble metal replacement cathode in fuel cells and metal-air batteries.

Effect of amino acid ligands on the structure of iron porphyrins and their ability to bind oxygen.

Science.gov (United States)

Berryman, Victoria E J; Baker, Matthew G; Boyd, Russell J

2014-06-26

Density functional theory is used to study a series of model iron porphyrins in the gas phase. In the first part of this study, three range-separated hybrid density functionals developed by Chai and Head-Gordon were assessed; ωB97, ωB97X, and ωB97XD. The effects of including full Hartree-Fock exchange at long-range and dispersion corrections are reported with respect to the geometries and binding energies of oxygen to the iron porphyrin systems. The functionals all correctly predict the quintet ground state for the deoxy-iron porphyrins, where typically hybrid functionals fail and predict a triplet ground state. Including dispersion in ωB97XD is shown to give the best results for the O2 binding energy and geometrical parameters. The second part of the study employs ωB97XD to study iron porphine systems with different amino acids in the axial position. Geometrical parameters are reported and compared to experimental data, where available. Binding energies of the systems with oxygen are also reported and discussed.

Institutionalising co-operation : a study of the Elysée treaty and Franco-German co-operation 1963-1993

OpenAIRE

Sverdrup, Bjørn Otto

1994-01-01

"INSTITUTIONALISING CO-OPERATION. A STUDY OF THE ELYSÉE TREATY AND FRANCO-GERMAN CO-OPERATION 1963-93" In 1963, France and Germany completed 'The Franco-German Treaty on Organization and Principles of Co-operation', the so-called Elysée Treaty. The Elysée Treaty, and its protocols, are in this study viewed as a political institution, hence the Elysée Treaty will be referred to as the Franco-German institution. This study seeks to answer the question of how the Franco-German institution has...

Fluorescently labelled bovine acyl-CoA-binding protein acting as an acyl-CoA sensor: interaction with CoA and acyl-CoA esters and its use in measuring free acyl-CoA esters and non-esterified fatty acids

DEFF Research Database (Denmark)

Wadum, M.C.; Villadsen, J.K.; Feddersen, S.

2002-01-01

methods for the determination of free acyl-CoA concentrations. No such method is presently available. In the present study, we describe the synthesis of two acyl-CoA sensors for measuring free acyl-CoA concentrations using acyl-CoA-binding protein as a scaffold. Met24 and Ala53 of bovine acyl...... of ligand (excitation 387nm). Titration of FACI-24 and FACI-53 with hexadecanoyl-CoA and dodecanoyl-CoA increased the fluorescence yield 5.5-and 4.7-fold at 460 and 495nm respectively. FACI-24 exhibited a high, and similar increase in, fluorescence yield at 460nm upon binding of C14-C20 saturated...

Oxygen vacancies induced enhancement of photoconductivity of La0.5Sr0.5CoO3 - δ thin film

Science.gov (United States)

Gao, R. L.; Fu, C. L.; Cai, W.; Chen, G.; Deng, X. L.; Yang, H. W.; Sun, J. R.; Zhao, Y. G.; Shen, B. G.

2014-09-01

Effects of light and electrical current on the electrical transport properties and photovoltaic properties of oxygen-stoichiometric La0.5Sr0.5CoO3 and oxygen-deficient La0.5Sr0.5CoO3 - δ films prepared by pulsed laser deposition have been investigated. Oxygen-deficient films annealed in a vacuum show an obvious increase of resistance and lattice parameter. Besides, a direct correlation between the magnitude of the photoconductivity and oxygen vacancies in La0.5Sr0.5CoO3 - δ films has been observed. The light illumination causes a resistance drop to show the photoconductivity effect. Moreover, the photoconductivity can be remarkably enhanced by increasing the electrical current, that is, it exhibits current-enhanced photoconductivity (CEPC) effect. Oxygen deficiency in the annealed film leads to the formation of a structural disorder in the Co-O-Co conduction channel due to the accumulated oxygen vacancies and hence is believed to be responsible for the increase in higher photoconductivity. These results may be important for practical applications in photoelectric devices.

Oxygen surfactant-assisted growth and dewetting of Co films on O-3 × 3/W(111)

Energy Technology Data Exchange (ETDEWEB)

Hsueh, Kun-Jen; Tsai, Cheng-Jui; Lin, Wen-Chin, E-mail: wclin@ntnu.edu.tw [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China); Wu, Shih-Yu; Chou, Hsin-Lei; Kuo, Chien-Cheng, E-mail: cckuo@faculty.nsysu.edu.tw [Department of Physics, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Bisio, Francesco [CNR-SPIN, C.so Perrone 24, I-16152 Genova (Italy)

2013-11-28

Following the cyclic heating in oxygen and annealing, an oxygen-induced 3 × 3 reconstruction was found on the W(111) surface. The growth, crystalline structure, thermal stability, and magnetism of Co ultrathin films deposited on the O-3 × 3/W(111) surface were investigated. The Auger signal of the oxygen was always observable and nearly invariant after either Co deposition or annealing, indicating the role of the surfactant played by oxygen. Auger electron spectroscopy and scanning tunneling microscopy measurements revealed the 2-dimensional growth of Co on O-3 × 3/W(111). Following the annealing procedures, the surfactant oxygen was always observed to float on the film surface while the Co film transformed to 3-dimensional islands with a wetting layer. In contrast to the thermodynamically stable wetting layer of 1 physical monolayer (PML) Co on clean W(111) between 700 and 1000 K, the oxygen surfactant led to a reduction of the wetting layer to ≈1/3 PML after thermal annealing. The 6 and 9.6 PML Co/O-3 × 3/W(111) revealed a stable in-plane magnetic anisotropy. A 6-fold symmetry corresponding to the crystalline structure was observed in the in-plane angle-dependent magneto-optical Kerr effect measurement.

Oxygen surfactant-assisted growth and dewetting of Co films on O-3 × 3/W(111)

International Nuclear Information System (INIS)

Hsueh, Kun-Jen; Tsai, Cheng-Jui; Lin, Wen-Chin; Wu, Shih-Yu; Chou, Hsin-Lei; Kuo, Chien-Cheng; Bisio, Francesco

2013-01-01

Following the cyclic heating in oxygen and annealing, an oxygen-induced 3 × 3 reconstruction was found on the W(111) surface. The growth, crystalline structure, thermal stability, and magnetism of Co ultrathin films deposited on the O-3 × 3/W(111) surface were investigated. The Auger signal of the oxygen was always observable and nearly invariant after either Co deposition or annealing, indicating the role of the surfactant played by oxygen. Auger electron spectroscopy and scanning tunneling microscopy measurements revealed the 2-dimensional growth of Co on O-3 × 3/W(111). Following the annealing procedures, the surfactant oxygen was always observed to float on the film surface while the Co film transformed to 3-dimensional islands with a wetting layer. In contrast to the thermodynamically stable wetting layer of 1 physical monolayer (PML) Co on clean W(111) between 700 and 1000 K, the oxygen surfactant led to a reduction of the wetting layer to ≈1/3 PML after thermal annealing. The 6 and 9.6 PML Co/O-3 × 3/W(111) revealed a stable in-plane magnetic anisotropy. A 6-fold symmetry corresponding to the crystalline structure was observed in the in-plane angle-dependent magneto-optical Kerr effect measurement

Women and International Intellectual Co-Operation

Science.gov (United States)

Goodman, Joyce

2012-01-01

The article explores ways in which intellectual co-operation at the League of Nations [SDN] provided a space for the engagement of culturally elite women in intellectual co-operation circles in Geneva, Paris and a range of national contexts stretching across Europe, Latin America and Asia. It discusses the language of the "international mind" and…

The Co-Operative: Good with Schools?

Science.gov (United States)

Coates, Max

2015-01-01

The article is a summary of a small-scale research project which considers the formation of Co-operative Trust Schools. This was carried out in 2013 at a time when the number of schools becoming Academies and Trust Schools through the Co-operative College was burgeoning. Through questionnaire, interview, documentary analysis and exploration of…

Technical Update: Johnson Space Center system using a solid electrolytic cell in a remote location to measure oxygen fugacities in CO/CO2 controlled-atmosphere furnaces

Science.gov (United States)

Jurewicz, A. J. G.; Williams, R. J.; Le, L.; Wagstaff, J.; Lofgren, G.; Lanier, A.; Carter, W.; Roshko, A.

1993-01-01

Details are given for the design and application of a (one atmosphere) redox-control system. This system differs from that given in NASA Technical Memorandum 58234 in that it uses a single solid-electrolytic cell in a remote location to measure the oxygen fugacities of multiple CO/CO2 controlled-atmosphere furnaces. This remote measurement extends the range of sample-furnace conditions that can be measured using a solid-electrolytic cell, and cuts costs by extending the life of the sensors and by minimizing the number of sensors in use. The system consists of a reference furnace and an exhaust-gas manifold. The reference furnace is designed according to the redox control system of NASA Technical Memorandum 58234, and any number of CO/CO2 controlled-atmosphere furnaces can be attached to the exhaust-gas manifold. Using the manifold, the exhaust gas from individual CO/CO2 controlled atmosphere furnaces can be diverted through the reference furnace, where a solid-electrolyte cell is used to read the ambient oxygen fugacity. The oxygen fugacity measured in the reference furnace can then be used to calculate the oxygen fugacity in the individual CO/CO2 controlled-atmosphere furnace. A BASIC computer program was developed to expedite this calculation.

Control of magnetic properties and band gap by Co/Mn ordering and oxygen distributions of La{sub 2}CoMnO{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Liu, Fang; Gao, Yu; Chang, Hong, E-mail: changhong@imu.edu.cn; Liu, Yifan; Yun, Yuehou

2017-08-01

Highlights: • The stretching vibration of the ordered Co-O-Mn bond is observed in IR-FT curve. • The surface absorbed oxygen transforms to the lattice oxygen is observed at 905 °C. - Abstract: La{sub 2}CoMnO{sub 6} are synthesized at different annealing temperature ranging from 600 °C to 1300 °C, marked as S600, S800, S1000 and S1300. S600 has the R-3c and the rest have the Pnma structure. The DTA curve exhibits two exothermic peaks, at 553 °C for the phase formation and 905 °C for the oxygen redistribution into the lattice. Deduced from xps, S1000 has the highest lattice oxygen. S1300 has one extra xps peak due to the oxygen deficient regions. Even though the xrd refinements are not reliable at telling whether Co/Mn ions are ordered or not, IR-FT, magnetic measurements and energy band gaps indicate that S1000 has the best Co/Mn ordering, and S600 has the worst. A stretching vibration at about 580–595 cm{sup −1} in the IR-FT spectra is attributed to the ordered Co–O–Mn bond. A homogenous atomic distribution in S600, S800 and S1000 leads to one magnetic phase configuration, and the agglomeration of the FM ordered Co/Mn and the AFM disordered regions in S1300 induces the multi magnetic phases. From the aspects of band gap and energy level, S600 is a good candidate for light harvesting.

Pulse height measurements and electron attachment in drift chambers operated with Xe,CO{sub 2} mixtures

Energy Technology Data Exchange (ETDEWEB)

Andronic, A. E-mail: a.andronic@gsi.de; Appelshaeuser, H.; Blume, C.; Braun-Munzinger, P.; Bucher, D.; Busch, O.; Ramirez, A.C.A. Castillo; Catanescu, V.; Ciobanu, M.; Daues, H.; Devismes, A.; Emschermann, D.; Fateev, O.; Garabatos, C.; Herrmann, N.; Ivanov, M.; Mahmoud, T.; Peitzmann, T.; Petracek, V.; Petrovici, M.; Reygers, K.; Sann, H.; Santo, R.; Schicker, R.; Sedykh, S.; Shimansky, S.; Simon, R.S.; Smykov, L.; Soltveit, H.K.; Stachel, J.; Stelzer, H.; Tsiledakis, G.; Vulpescu, B.; Wessels, J.P.; Windelband, B.; Winkelmann, O.; Xu, C.; Zaudtke, O.; Zanevsky, Yu.; Yurevich, V

2003-02-11

We present pulse height measurements in drift chambers operated with Xe,CO{sub 2} gas mixtures. We investigate the attachment of primary electrons on oxygen and SF{sub 6} contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and {sup 55}Fe pulse height measurements using monitor detectors.

Marketing co-operatives

NARCIS (Netherlands)

G.W.J. Hendrikse (George); C.P. Veerman (Cees)

2000-01-01

textabstractMarketing co-operatives (MCs) are analysed from an incomplete contracting perspective. The requirement of the domination of control by the members of a MC is a threat to the survival of a MC in markets where the level of asset specificity at the processing stage of production is

Disruption of the Acyl-CoA binding protein gene delays hepatic adaptation to metabolic changes at weaning

DEFF Research Database (Denmark)

Neess, Ditte; Marcher, Ann-Britt; Bloksgaard, Maria

The acyl-CoA binding protein/diazepam binding inhibitor (ACBP/DBI) is an evolutionary conserved intracellular protein that binds C14-C22 acyl-CoA esters with very high affinity. ACBP is thought to act as an acyl-CoA transporter, and in vitro analyses have indicated that ACBP can transport acyl......-CoA esters between different enzymatic systems. However, little is known about the in vivo function in mammalian cells. We have generated mice with targeted disruption of ACBP (ACBP-/-). These mice are viable and fertile and develop normally. However, around weaning the ACBP-/- mice show decreased growth......) family, around the weaning period. As a result, the hepatic de novo cholesterogenesis is significantly decreased at weaning. The delayed induction of SREBP target genes around weaning is caused by a compromised processing and decreased expression of SREBP precursors leading to reduced binding of SREBP...

"A model co-operative country": Irish-Finnish co-operative contacts at the turn of the twentieth century

DEFF Research Database (Denmark)

Hilson, Mary

2017-01-01

Agricultural co-operative societies were widely discussed across late nineteenth-century Europe as a potential solution to the problems of agricultural depression, land reform and rural poverty. In Finland, the agronomist Hannes Gebhard drew inspiration from examples across Europe in founding the...... that even before the First World War it was Finland, not Ireland, that had begun to be regarded as ‘a model co-operative country’....... between Irish and Finnish co-operators around the turn of the century, and examines the ways in which the parallels between the two countries were constructed and presented by those involved in these exchanges. I will also consider the reasons for the divergence in the development of cooperation, so...

Toward a lithium-"air" battery: the effect of CO2 on the chemistry of a lithium-oxygen cell.

Science.gov (United States)

Lim, Hyung-Kyu; Lim, Hee-Dae; Park, Kyu-Young; Seo, Dong-Hwa; Gwon, Hyeokjo; Hong, Jihyun; Goddard, William A; Kim, Hyungjun; Kang, Kisuk

2013-07-03

Lithium-oxygen chemistry offers the highest energy density for a rechargeable system as a "lithium-air battery". Most studies of lithium-air batteries have focused on demonstrating battery operations in pure oxygen conditions; such a battery should technically be described as a "lithium-dioxygen battery". Consequently, the next step for the lithium-"air" battery is to understand how the reaction chemistry is affected by the constituents of ambient air. Among the components of air, CO2 is of particular interest because of its high solubility in organic solvents and it can react actively with O2(-•), which is the key intermediate species in Li-O2 battery reactions. In this work, we investigated the reaction mechanisms in the Li-O2/CO2 cell under various electrolyte conditions using quantum mechanical simulations combined with experimental verification. Our most important finding is that the subtle balance among various reaction pathways influencing the potential energy surfaces can be modified by the electrolyte solvation effect. Thus, a low dielectric electrolyte tends to primarily form Li2O2, while a high dielectric electrolyte is effective in electrochemically activating CO2, yielding only Li2CO3. Most surprisingly, we further discovered that a high dielectric medium such as DMSO can result in the reversible reaction of Li2CO3 over multiple cycles. We believe that the current mechanistic understanding of the chemistry of CO2 in a Li-air cell and the interplay of CO2 with electrolyte solvation will provide an important guideline for developing Li-air batteries. Furthermore, the possibility for a rechargeable Li-O2/CO2 battery based on Li2CO3 may have merits in enhancing cyclability by minimizing side reactions.

International co-operation. Key issue paper no. 6

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

In accordance with guidance provided by the Steering Group, this report assesses the adequacy and effectiveness of international co-operation relating to the nuclear fuel cycle, with a view toward identifying any needed new forms or arrangements for co-operation. In more specific terms, the Steering Committee`s guidance identified the following questions: Is the existing international framework sufficient for: the safe and secure operation of the fuel cycle; the economic and orderly development of the world`s nuclear energy systems (or their phase-out should this take place); international co-operation in R and D; international co-operation in industrial activities? Are there places where these requirements overlap or interact so as to impede activities which are desirable? Can new forms of co-operation be foreseen which would make it easier to implement any of the fuel cycle options in a safe, secure and responsible way? Are there other new forms of international co-operation which would affect the fuel cycle, e.g. regional institutions; international plutonium management regime and/or storage? Finally: What is the appropriate role of IAEA in any of these?.

DNA Damage: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes

Science.gov (United States)

Quesne, Matthew G; Latifi, Reza; Gonzalez-Ovalle, Luis E; Kumar, Devesh; de Visser, Sam P

2014-01-01

AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N1-methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)–oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ-and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained. PMID:24339041

CO2 for refrigeration. Co-operation with Indonesia

International Nuclear Information System (INIS)

Bredesen, Arne M.

2000-01-01

NTNU and SINTEF Energy Research, Norway, have co-operated closely with universities in Indonesia on the use of CO2 as a working fluid in refrigeration systems. The Asian market is the largest in the world and so it is very important to use environmentally friendly working fluids. In Indonesia, Institut Teknologi Bandung (ITB) plays a leading role in the efforts to meet the national emission goals. For economical reasons, Indonesia considers natural working fluids such as CO2 rather than the new expensive synthetic ones

Development of novel CO{sub 2}-stable oxygen permeable dual phase membranes for CO{sub 2} capture in an oxy-fuel process

Energy Technology Data Exchange (ETDEWEB)

Luo, Huixia

2012-07-19

The combustion of fossil fuels in power stations with pure oxygen following the oxy-fuel process allows the Sequestration of CO{sub 2}. The pure oxygen needed can be separated from air by oxygen transporting ceramics like single phase perovskites. However, most of the so far developed single phase perovskites have stability problems in a CO{sub 2} containing atmosphere. Dual phase membranes are micro-scale mixtures of an electron conducting phase and an oxygen ion conducting phase and their compositions can be tailored according to practical requirements, which are considered to be promising substitutes for the single phase perovskite materials. In my thesis the issues of phase stability for perovskite-type material with the common composition Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 3-{delta}} (BSCF) as weil as the development of a series of novel CO{sub 2}-stable dual phase membranes were studied. In Chapter 2, the phase stability and permeation behavior of a dead-end BSCF tube membrane in high-purity oxygen at temperatures below 750 C, were elucidated using powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDXS), high-angle annular dark-field (HAADF) and scanning transmission electron microscopy (STEM). lt was found that parts of the cubic perovskite BSCF transformed into a hexagonal perovskite Ba{sub 0.5{+-}x}Sr{sub 0.5{+-}x}CoO{sub 3-{delta}} (x {approx} 0.1) and a trigonal mixed oxide Ba{sub 1-x}Sr{sub x}CO{sub 2-y}Fe{sub y}O{sub 5{+-}{delta}} (x {approx} 0.15, y {approx} 0.25) in high-purity oxygen at 750 C. On the other hand, it was found that the partial degradation of cubic BSCF perovskite at 750 C was more pronounced under the strongly oxidizing conditions on the oxygen supply (feed) side than on the oxygen release (permeate) side of the membrane. The structural instability of BSCF is attributed to an oxidation of cobalt from Co{sup 2+} to Co{sup 3+} and Co{sup 4+}, which exhibits an ionic radius that is too small to be tolerated by

Hemoglobin Rahere, a human hemoglobin variant with amino acid substitution at the 2,3-diphosphoglycerate binding site. Functional consequences of the alteration and effects of bezafibrate on the oxygen bindings.

OpenAIRE

Sugihara, J; Imamura, T; Nagafuchi, S; Bonaventura, J; Bonaventura, C; Cashon, R

1985-01-01

We encountered an abnormal hemoglobin (Rahere), with a threonine residue replacing the beta 82 (EF6) lysine residue at the binding site of 2,3-diphosphoglycerate, which was responsible for overt erythrocytosis in two individuals of a Japanese family. Hemoglobin Rahere shows a lower oxygen affinity on the binding of 2,3-diphosphoglycerate or chloride ions than hemoglobin A. Although a decrease in the positive charge density at the binding sites of 2,3-diphosphoglycerate in hemoglobin Rahere ap...

Diphosphoglycerate and Inosine Hexaphosphate Control of Oxygen Binding by Hemoglobin: A Theoretical Interpretation of Experimental Data*

Science.gov (United States)

Ling, Gilbert N.

1970-01-01

A theoretical equation is presented for the control of cooperative adsorption on proteins and other linear macromolecules by hormones, drugs, ATP, and other „cardinal adsorbents.” With reasonable accuracy, this equation describes quantitatively the control of oxygen binding to hemoglobin by 2,3-diphosphoglycerate and by inosine hexaphosphate. PMID:5272319

Analysis of oxygen binding-energy variations for BaO on W

Science.gov (United States)

Haas, G. A.; Shih, A.; Mueller, D.; Thomas, R. E.

Interatomic Auger analyses have been made of different forms of BaO layers on W substrates. Variations in Auger spectroscopy energies of the Ba4dBa5pO2p interatomic Auger transition were found to be largely governed by the O2p binding energy of the BaO adsorbate. This was illustrated by comparing results of the Auger data values with values derived from O2p binding energies using ultraviolet photoelectron spectroscopy. Very good agreement was observed not only for the W substrate but also for the W substrate which showed two oxygen-induced electronics state. Variations in binding energy were noted for different states of BaO lattice formation and for different amounts of oxidation, ranging from the transition of Ba to BaO and continuing to the BaO 2 stoichiometry and beyond. Effects were also reported for adsorbate alignment and thermal activation (i.e., reduction) of the oxidized state. An empirical relationship was found suggesting that the more tightly bound the O2p states of the BaO adsorbate were, the lower its work function would be. This link between binding energy and work function was observed to be valid not only for cases of poisoning by oxidation, but held as well during reactivation by the subsequent reduction of the oxide. In addition, this relationship also appeared to predict the low work function obtained through the introduction of substances such as Sc to the BaO-W system. Possible qualitative reasons which might contribute to this are discussed in terms of enhanced dipole effects and shifts in band structure.

China and CERN renew their Co-operation Agreement

CERN Multimedia

2004-01-01

Dr. Liu Yanhua, Chinese Vice Minister of Science and Technology, and Dr. Robert Aymar, Director-General of CERN, sign a new Co-operation Agreement between the Government of the People's Republic of China and CERN. During his visit to CERN on 17 February, Liu Yanhua, Vice Minister of Science and Technology of the People's Republic of China, signed a new Co-operation Agreement with the Laboratory. The Agreement, which is valid for a period of five years and renewable, lays down the framework for the development of scientific and technological co-operation between CERN and China. This includes China's participation, as a non-Member State, in CERN's research projects as well as its main programmes. Robert Aymar and Liu Yanhua underlined that this Agreement will provide an excellent framework for close co-operation on the LHC Programme and Grid and accelerator technologies. Scientific co-operation between China and CERN is nothing new, as Chinese physicists already took part in the LEP experiments. Today, CERN's C...

New co-operation agreement between CERN and JINR

CERN Multimedia

CERN Bulletin

2010-01-01

CERN Director-General Rolf Heuer (left) and JINR Director Alexei Sissakian (right). On Thursday 28 January, CERN Director-General Rolf Heuer and JINR Director Alexei Sissakian signed a new enlarged co-operation agreement to continue and enhance the scientific and technical co-operation of the two institutes in the field of high-energy physics. CERN and JINR have a long and successful history of collaboration extending back to the earliest days of their existence. The first informal meeting on international co-operation in the field of high-energy accelerators took place at CERN in 1959. It was attended by senior scientists from the United States, the USSR (including JINR) and CERN. Both JINR and CERN have played the role of a bridge between East and West for decades, contributing to the development of international scientific co-operation. In 1992 JINR signed a co-operation agreement with CERN that included an important number of protocols covering JINR’s participation in the construction of th...

Strengthening political co-operation through multilateral disarmament

International Nuclear Information System (INIS)

Ekeus, R.

1991-01-01

In this paper, the Ministry for Foreign Affairs of Sweden discussed how the multilateral disarmament concept has contributed and still can contribute to strengthen political co-operation. This approach is the opposite to the usual question on how to achieve multilateral disarmament through political co-operation

Technical co-operation for nuclear safety in developing countries

International Nuclear Information System (INIS)

Flakus, F.N.; Giuliani, P.

1984-01-01

The Agency's programme on technical co-operation for nuclear safety is, largely, responsive in character and the Agency's response is tailored to needs identified by developing countries. However, the Agency's assistance alone is not sufficient: technical co-operation can only be successful and is most effective when there is also a strong input from the counterpart body participating in a particular project. The commitment of national governments is fundamental to success. Technical co-operation is most fruitful if the Agency's assistance capabilities and the recipient country's co-operation capabilities match. Co-operation activities mostly take the form of single projects hosted by individual institutions within a single country; regional and inter-regional projects are also important

In Situ Observation of Oxygen Vacancy Dynamics and Ordering in the Epitaxial LaCoO3 System.

Science.gov (United States)

Jang, Jae Hyuck; Kim, Young-Min; He, Qian; Mishra, Rohan; Qiao, Liang; Biegalski, Michael D; Lupini, Andrew R; Pantelides, Sokrates T; Pennycook, Stephen J; Kalinin, Sergei V; Borisevich, Albina Y

2017-07-25

Vacancy dynamics and ordering underpin the electrochemical functionality of complex oxides and strongly couple to their physical properties. In the field of the epitaxial thin films, where connection between chemistry and film properties can be most clearly revealed, the effects related to oxygen vacancies are attracting increasing attention. In this article, we report a direct, real-time, atomic level observation of the formation of oxygen vacancies in the epitaxial LaCoO 3 thin films and heterostructures under the influence of the electron beam utilizing scanning transmission electron microscopy (STEM). In the case of LaCoO 3 /SrTiO 3 superlattice, the formation of the oxygen vacancies is shown to produce quantifiable changes in the interatomic distances, as well as qualitative changes in the symmetry of the Co sites manifested as off-center displacements. The onset of these changes was observed in both the [100] pc and [110] pc orientations in real time. Additionally, annular bright field images directly show the formation of oxygen vacancy channels along [110]pc direction. In the case of 15 u.c. LaCoO 3 thin film, we observe the sequence of events during beam-induced formation of oxygen vacancy ordered phases and find them consistent with similar processes in the bulk. Moreover, we record the dynamics of the nucleation, growth, and defect interaction at the atomic scale as these transformations happen. These results demonstrate that we can track dynamic oxygen vacancy behavior with STEM, generating atomic-level quantitative information on phase transformation and oxygen diffusion.

A novel CO>2- and SO>2-tolerant dual phase composite membrane for oxygen separation

DEFF Research Database (Denmark)

Cheng, Shiyang; Søgaard, Martin; Han, Li

2015-01-01

A novel dual phase composite oxygen membrane (Al0.02Ga0.02Zn0.96O1.02 – Gd0.1Ce0.9O1.95-δ) was successfully prepared and tested. The membrane shows chemical stability against CO2 and SO2, and a stable oxygen permeation over 300 hours in CO2 was demonstrated. ZnO is cheap and non-toxic...... and is therefore highly advantageous compared to other common materials used for the purpose....

Concurrent CO2 Control and O2 Generation for Advanced Life Support

Science.gov (United States)

Paul, Heather L.; Duncan, Keith L.; Hagelin-Weaver, Helena E.; Bishop, Sean R.; Wachsman, Eric D.

2007-01-01

The electrochemical reduction of carbon dioxide (CO2) using ceramic oxygen generators (COGs) is well known and widely studied, however, conventional devices using yttria-stabilized zirconia (YSZ) electrolytes operate at temperatures greater than 700 C. Operating at such high temperatures increases system mass compared to lower temperature systems because of increased energy overhead to get the COG up to operating temperature and the need for heavier insulation and/or heat exchangers to reduce the COG oxygen (O2) output temperature for comfortable inhalation. Recently, the University of Florida developed novel ceramic oxygen generators employing a bilayer electrolyte of gadolinia-doped ceria and erbia-stabilized bismuth for NASA's future exploration of Mars. To reduce landed mass and operation expenditures during the mission, in-situ resource utilization was proposed using these COGs to obtain both lifesupporting oxygen and oxidant/propellant fuel, by converting CO2 from the Mars atmosphere. The results showed that oxygen could be reliably produced from CO2 at temperatures as low as 400 C. These results indicate that this technology could be adapted to CO2 removal from a spacesuit and other applications in which CO2 removal was an issue. The strategy proposed for CO2 removal for advanced life support systems employs a catalytic layer combined with a COG so that it is reduced all the way to solid carbon and oxygen. Hence, a three-phased approach was used for the development of a viable low weight COG for CO2 removal. First, to reduce the COG operating temperature a high oxide ion conductivity electrolyte was developed. Second, to promote full CO2 reduction while avoiding the problem of carbon deposition on the COG cathode, novel cathodes and a removable catalytic carbon deposition layer were designed. Third, to improve efficiency, a pre-stage for CO2 absorption was used to concentrate CO2 from the exhalate before sending it to the COG. These subsystems were then

TUNABLE MAGNETIC AND ELECTRICAL PROPERTIES OF Co-DOPED ZnO FILMS BY VARYING OXYGEN PARTIAL PRESSURE

OpenAIRE

L. G. WANG; H. W. ZHANG; X. L. TANG; Y. X. LI; Z. Y. ZHONG

2011-01-01

High quality Co-doped ZnO films with good reproducibility have been prepared under different oxygen partial pressure by radio-frequency magnetron sputtering. These films were characterized using numerous characterization techniques including X-ray diffraction, electrical transport, and magnetization measurements. The effect of oxygen partial pressure on the structural, magnetic, and electrical properties of Co-doped ZnO films has been systematically studied. It was found that the structural, ...

Nanoscale compositional changes and modification of the surface reactivity of Pt3Co/C nanoparticles during proton-exchange membrane fuel cell operation

International Nuclear Information System (INIS)

Dubau, L.; Maillard, F.; Chatenet, M.; Andre, J.; Rossinot, E.

2010-01-01

This study bridges the structure/composition of Pt-Co/C nanoparticles with their surface reactivity and their electrocatalytic activity. We show that Pt 3 Co/C nanoparticles are not stable during PEMFC operation (H 2 /air; j = 0.6 A cm -2 , T = 70 o C) but suffer compositional changes at the nanoscale. In the first hours of operation, the dissolution of Co atoms at their surface yields to the formation of a Pt-enriched shell covering a Pt-Co alloy core ('Pt-skeleton') and increases the affinity of the surface to oxygenated and hydrogenated species. This structure does not ensure stability in PEMFC conditions but is rather a first step towards the formation of 'Pt-shell/Pt-Co alloy core' structures with depleted Co content. In these operating conditions, the Pt-Co/C specific activity for the ORR varies linearly with the fraction of Co alloyed to Pt present in the core and is severely depreciated (ca. -50%) after 1124 h of operation. This is attributed to: (i) the decrease of both the strain and the ligand effect of Co atoms contained in the core (ii) the changes in the surface structure of the electrocatalyst (formation of a multilayer-thick Pt shell) and (iii) the relaxation of the Pt surface atoms.

CO hydrogenation to methanol on Cu–Ni catalysts

DEFF Research Database (Denmark)

Studt, Felix; Abild-Pedersen, Frank; Wu, Qiongxiao

2012-01-01

two descriptors, the carbon oxygen binding energies, are constructed. A micro-kinetic model of CO hydrogenation is developed and a volcano-shaped relation based on the two descriptors is obtained for methanol synthesis. A large number of bimetallic alloys with respect to the two descriptors...

Role of acylCoA binding protein in acylCoA transport, metabolism and cell signaling

DEFF Research Database (Denmark)

Knudsen, J; Jensen, M V; Hansen, J K

1999-01-01

and pool formation and therefore also for the function of LCAs as metabolites and regulators of cellular functions [1]. The major factors controlling the free concentration of cytosol long chain acylCoA ester (LCA) include ACBP [2], sterol carrier protein 2 (SCP2) [3] and fatty acid binding protein (FABP...

Detection of site-specific binding and co-binding of ligands to macromolecules using 19F NMR

International Nuclear Information System (INIS)

Jenkins, B.G.

1991-01-01

Study of ligand-macromolecular interactions by 19 F nuclear magnetic resonance (NMR) spectroscopy affords many opportunities for obtaining molecular biochemical and pharmaceutical information. This is due to the absence of a background fluorine signal, as well as the relatively high sensitivity of 19 F NMR. Use of fluorine-labeled ligands enables one to probe not only binding and co-binding phenomena to macromolecules, but also can provide data on binding constants, stoichiometries, kinetics, and conformational properties of these complexes. Under conditions of slow exchange and macromolecule-induced chemical shifts, multiple 19 F NMR resonances can be observed for free and bound ligands. These shifted resonances are a direct correlate of the concentration of ligand bound in a specific state rather than the global concentrations of bound or free ligand which are usually determined using other techniques such as absorption spectroscopy or equilibrium dialysis. Examples of these interactions are demonstrated both from the literature and from interactions of 5-fluorotryptophan, 5-fluorosalicylic acid, flurbiprofen, and sulindac sulfide with human serum albumin. Other applications of 19 F NMR to study of these interactions in vivo, as well for receptor binding and metabolic tracing of fluorinated drugs and proteins are discussed

Sixteen Years of International Co-operation. The OECD/NEA Co-operative Programme on Decommissioning

International Nuclear Information System (INIS)

Menon, S.; Valencia, L.

2002-01-01

The Co-operative Programme on Decommissioning under the administration of the Radioactive Waste Management Committee of the OECD Nuclear Energy Agency (NEA) has recently completed sixteen years of operation. The Programme, which is essentially an information exchange programme between decommissioning projects, came into being in 1985. It has grown from an initial 10 decommissioning projects from 7 countries to 39 projects from 14 countries today. From purely information exchange to start with, the Programme has, in later years, been functioning as a voice for the collective expression of views of the implementers of nuclear decommissioning. During the first sixteen years of the operation of the Co-operative Programme, nuclear decommissioning has grown from local specialist activities within projects to a competitive commercial industry. By the dismantling and release from regulatory control of over a dozen diverse nuclear facilities, the Programme has been able to demonstrate in practice, that nuclear decommissioning can be performed safely both for the workers and the public, and that this can be done at reasonable costs in an environmentally friendly fashion. During the recent years, discussions and work within the Co-operative Programme, specially within some of the Task Groups, have had/are having effects and repercussions not just in the field of nuclear decommissioning, but can possibly affect activities and regulations in other industries. This paper describes how the Programme and its activities and procedures have evolved over the years and indicate the directions of developments in the organization and execution of decommissioning projects. Finally, it gives a brief overview of the achievements of the Cooperative Programme and visualizes future developments in the field of nuclear decommissioning

The Shanghai Co-operation Organisation

DEFF Research Database (Denmark)

Hansen, Flemming Splidsboel

New regional organisations are always interesting to follow as they will tell us more about the things that make or break this type of co-operation. Originally established as “The Shanghai Five” in 1996, The Shanghai Co-operation Organisation (SCO) has been successful at reducing tension between...... the member states but it has since found it very hard to come up with a more ambitious agenda. Mutual suspicion and zero-sum thinking clearly run deep and the continued development of the organisation has suffered as a result of this. All told, the SCO is much more façade than real policy substance....

Oxygen permeation and stability of La 0.4Ca 0.6Fe 1-xCo xO 3-δ ( x = 0, 0.25, 0.5) membranes

Science.gov (United States)

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.

Measuring oxygen yields of a thermal conversion/elemental analyzer-isotope ratio mass spectrometer for organic and inorganic materials through injection of CO.

Science.gov (United States)

Yin, Xijie; Chen, Zhigang

2014-12-01

The thermal conversion/elemental analyzer-isotope ratio mass spectrometer (TC/EA-IRMS) is widely used to measure the δ(18) O value of various substances. A premise for accurate δ(18) O measurement is that the oxygen in the sample can be converted into carbon monoxide (CO) quantitatively or at least proportionally. Therefore, a precise method to determine the oxygen yield of TC/EA-IRMS measurements is needed. Most studies have used the CO peak area obtained from a known amount of a solid reference material (for example, benzoic acid) to calibrate the oxygen yield of the sample. Although it was assumed that the oxygen yield of the solid reference material is 100%, no direct evidence has been provided. As CO is the analyte gas for δ(18) O measurement by IRMS, in this study, we use a six-port valve to inject CO gas into the TC/EA. The CO is carried to the IRMS by the He carrier gas and the CO peak area is measured by the IRMS. The CO peak area thus obtained from a known amount of the injected CO is used to calibrate the oxygen yield of the sample. The oxygen yields of commonly used organic and inorganic reference materials such as benzoic acid (C6 H5 COOH), silver phosphate (Ag3 PO4 ), calcium carbonate (CaCO3 ) and silicon dioxide (SiO2 ) are investigated at different reactor temperatures and sample sizes. We obtained excellent linear correlation between the peak area for the injected CO and its oxygen atom amount. C6 H5 COOH has the highest oxygen yield, followed by Ag3 PO4 , CaCO3 and SiO2 . The oxygen yields of TC/EA-IRMS are less than 100% for both organic and inorganic substances, but the yields are relatively stable at the specified reactor temperature and for a given quantity of sample. Copyright © 2014 John Wiley & Sons, Ltd.

MO-Co@N-Doped Carbon (M = Zn or Co): Vital Roles of Inactive Zn and Highly Efficient Activity toward Oxygen Reduction/Evolution Reactions for Rechargeable Zn-Air Battery

Energy Technology Data Exchange (ETDEWEB)

Chen, Biaohua [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Beijing Key Laboratory of Energy Environmental Catalysis, Beijing University of Chemical Technology, Beijing 100029 P. R. China; He, Xiaobo [Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Changzhou 213164 P. R. China; Yin, Fengxiang [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Beijing Key Laboratory of Energy Environmental Catalysis, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Changzhou 213164 P. R. China; Wang, Hao [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Beijing Key Laboratory of Energy Environmental Catalysis, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne IL 60439 USA; Liu, Di-Jia [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne IL 60439 USA; Shi, Ruixing [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Chen, Jinnan [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 P. R. China; Yin, Hongwei [State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 P. R. China

2017-06-14

A highly efficient bifunctional oxygen catalyst is required for practical applications of fuel cells and metal-air batteries, as oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are their core electrode reactions. Here, the MO-Co@ N-doped carbon (NC, M = Zn or Co) is developed as a highly active ORR/OER bifunctional catalyst via pyrolysis of a bimetal metal-organic framework containing Zn and Co, i.e., precursor (CoZn). The vital roles of inactive Zn in developing highly active bifunctional oxygen catalysts are unraveled. When the precursors include Zn, the surface contents of pyridinic N for ORR and the surface contents of Co-N-x and Co3+/Co2+ ratios for OER are enhanced, while the high specific surface areas, high porosity, and high electrochemical active surface areas are also achieved. Furthermore, the synergistic effects between Zn-based and Co-based species can promote the well growth of multiwalled carbon nanotubes (MWCNTs) at high pyrolysis temperatures (>= 700 degrees C), which is favorable for charge transfer. The optimized CoZn-NC-700 shows the highly bifunctional ORR/OER activity and the excellent durability during the ORR/OER processes, even better than 20 wt% Pt/C (for ORR) and IrO2 (for OER). CoZn-NC-700 also exhibits the prominent Zn-air battery performance and even outperforms the mixture of 20 wt% Pt/C and IrO2.

Bifunctional bamboo-like CoSe2 arrays for high-performance asymmetric supercapacitor and electrocatalytic oxygen evolution

Science.gov (United States)

Chen, Tian; Li, Songzhan; Gui, Pengbin; Wen, Jian; Fu, Xuemei; Fang, Guojia

2018-05-01

Bifunctional bamboo-like CoSe2 arrays are synthesized by thermal annealing of Co(CO3)0.5OH grown on carbon cloth in Se atmosphere. The CoSe2 arrays obtained have excellent electrical conductivity, larger electrochemical active surface areas, and can directly serve as a binder-free electrode for supercapacitors and the oxygen evolution reaction (OER). When tested as a supercapacitor electrode, the CoSe2 delivers a higher specific capacitance (544.6 F g‑1 at current density of 1 mA cm‑2) compared with CoO (308.2 F g‑1) or Co3O4 (201.4 F g‑1). In addition, the CoSe2 electrode possesses excellent cycling stability. An asymmetric supercapacitor (ASC) is also assembled based on bamboo-like CoSe2 as a positive electrode and active carbon as a negative electrode in a 3.0 M KOH aqueous electrolyte. Owing to the unique stucture and good electrochemical performance of bamboo-like CoSe2, the as-assembled ACS can achieve a maximum operating voltage window of 1.7 V, a high energy density of 20.2 Wh kg‑1 at a power density of 144.1 W kg‑1, and an outstanding cyclic stability. As the catalyst for the OER, the CoSe2 exhibits a lower potential of 1.55 V (versus RHE) at current density of 10 mA cm‑2, a smaller Tafel slope of 62.5 mV dec‑1 and an also outstanding stability.

Oxygen nonstoichiometry and thermo-chemical stability of La0.6Sr0.4CoO3−δ

International Nuclear Information System (INIS)

Kuhn, M.; Hashimoto, S.; Sato, K.; Yashiro, K.; Mizusaki, J.

2013-01-01

The oxygen nonstoichiometry of La 0.6 Sr 0.4 CoO 3−δ has been the topic of various reports in the literature, but has been exclusively measured at high oxygen partial pressures, pO 2 , and/or elevated temperatures. For applications of La 0.6 Sr 0.4 CoO 3−δ , such as solid oxide fuel cell cathodes or oxygen permeation membranes, knowledge of the oxygen nonstoichiometry and thermo-chemical stability over a wide range of pO 2 is crucial, as localized low pO 2 could trigger failure of the material and device. By employing coulometric titration combined with thermogravimetry, the oxygen nonstoichiometry of La 0.6 Sr 0.4 CoO 3−δ was measured at high and intermediate pO 2 until the material decomposed (at log(pO 2 /bar)≈−4.5 at 1073 K). For a gradually reduced sample, an offset in oxygen content suggests that La 0.6 Sr 0.4 CoO 3−δ forms a “super-reduced” solid solution before decomposing. When the sample underwent alternate reduction–oxidation, a hysteresis-like pO 2 dependence of the oxygen content in the decomposition pO 2 range was attributed to the reversible formation of ABO 3 and A 2 BO 4 phases. Reduction enthalpy and entropy were determined for the single-phase region and confirmed interpolated values from the literature. - Graphical abstract: Oxygen nonstoichiometry (shown as 3−δ) of La 0.6 Sr 0.4 CoO 3−δ as a function of pO 2 at 773–1173 K. The experimental data were obtained by thermogravimetric analysis (TG) and coulometric titration (measured either by a simple reduction (CT1) or a “two-step-forward one-step-back” reduction–oxidation (CT2) procedure). D1 and D2 denote the decomposition pO 2 . The solid lines are the fit to the thermogravimetry and CT1 data. The dashed lines represent the non-equilibrium region where the sample shows a super-reduced state. Highlights: ► Oxygen nonstoichiometry of La 0.6 Sr 0.4 CoO 3−δ at intermediate temperatures and p(O2). ► Experimental confirmation of previously interpolated

NATO, Libya operations and intelligence co-operation – a step forward?

DEFF Research Database (Denmark)

Svendsen, Adam David Morgan

2011-01-01

developments can be opened up for some further analysis, forming the main focus of this article. Ultimately, this article concludes that, over time and albeit while gradual, we have seen what can be regarded as ‘a step forward’ in co-operative intelligence activities in Libya. Although several pressing......"With the ‘fall’ of Tripoli towards the end of August 2011, it has become increasingly apparent that the intelligence co-operation witnessed in Libya during the NATO campaign performed an increasingly important role in realizing operational and strategic ‘successes’. These recent intelligence...

Communication: CO oxidation by silver and gold cluster cations: Identification of different active oxygen species

International Nuclear Information System (INIS)

Popolan, Denisia M.; Bernhardt, Thorsten M.

2011-01-01

The oxidation of carbon monoxide with nitrous oxide on mass-selected Au 3 + and Ag 3 + clusters has been investigated under multicollision conditions in an octopole ion trap experiment. The comparative study reveals that for both gold and silver cations carbon dioxide is formed on the clusters. However, whereas in the case of Au 3 + the cluster itself acts as reactive species that facilitates the formation of CO 2 from N 2 O and CO, for silver the oxidized clusters Ag 3 O x + (n= 1-3) are identified as active in the CO oxidation reaction. Thus, in the case of the silver cluster cations N 2 O is dissociated and one oxygen atom is suggested to directly react with CO, whereas a second kind of oxygen strongly bound to silver is acting as a substrate for the reaction.

Communication: CO oxidation by silver and gold cluster cations: Identification of different active oxygen species

Science.gov (United States)

Popolan, Denisia M.; Bernhardt, Thorsten M.

2011-03-01

The oxidation of carbon monoxide with nitrous oxide on mass-selected Au3+ and Ag3+ clusters has been investigated under multicollision conditions in an octopole ion trap experiment. The comparative study reveals that for both gold and silver cations carbon dioxide is formed on the clusters. However, whereas in the case of Au3+ the cluster itself acts as reactive species that facilitates the formation of CO2 from N2O and CO, for silver the oxidized clusters Ag3Ox+ (n = 1-3) are identified as active in the CO oxidation reaction. Thus, in the case of the silver cluster cations N2O is dissociated and one oxygen atom is suggested to directly react with CO, whereas a second kind of oxygen strongly bound to silver is acting as a substrate for the reaction.

Isotope exchange of molecular oxygen with oxygen of La0,7Sr0,3CoO3-δ

International Nuclear Information System (INIS)

Vdovin, G.K.; Kuzin, B.L.; Kurumchin, Eh.Kh.

1991-01-01

The exchange rate of the oxygen in La 0,7 Sr 0,3 CoO 3-δ has been measured by an isotopic exchange method at temperatures 620-1250 K and pressures 1.6-10 torr. The activation energy and the dependence of the exchange rate on pressures in gas have been defined. It is suggested that the knees on the temperature dependences of the exchange rate are attributed to the appearance of Co 2+ ions on the surface of the sample at elevated temperature as new centres of the exchange reaction. The activation energies of the adsorption and desorption processes on the La 0,7 Sr 0,3 CoO 3-δ surface have been estimated

La0.8Sr0.2Co0.8Ni0.2O3-δ impregnated oxygen electrode for H2O/CO2 co-electrolysis in solid oxide electrolysis cells

Science.gov (United States)

Zheng, Haoyu; Tian, Yunfeng; Zhang, Lingling; Chi, Bo; Pu, Jian; Jian, Li

2018-04-01

High-temperature H2O/CO2 co-electrolysis through reversible solid oxide electrolysis cell (SOEC) provides potentially a feasible and eco-friendly way to convert electrical energy into chemicals stored in syngas. In this work, La0.8Sr0.2Co0.8Ni0.2O3-δ (LSCN) impregnated Gd0.1Ce0.9O1.95 (GDC)-(La0.8Sr0.2)0.95MnO3-δ (LSM) composite oxygen electrode is studied as high-performance electrode for H2O/CO2 co-electrolysis. The LSCN impregnated cell exhibits competitive performance with the peak power density of 1057 mW cm-2 at 800 °C in solid oxide fuel cell (SOFC) mode; in co-electrolysis mode, the current density can reach 1.60 A cm-2 at 1.5 V at 800 °C with H2O/CO2 ratio of 2/1. With LSCN nanoparticles dispersed on the surface of GDC-LSM to maximize the reaction active sites, the LSCN impregnated cell shows significant enhanced electrochemical performance at both SOEC and SOFC modes. The influence of feed gas composition (H2O-H2-CO2) and operating voltages on the performance of co-electrolysis are discussed in detail. The cell shows a very stable performance without obvious degradation for more than 100 h. Post-test characterization is analyzed in detail by multiple measurements.

Decommissioning Combustible Waste Treatment using Oxygen-Enriched Incinerator

Energy Technology Data Exchange (ETDEWEB)

Min, Byungyoun; Lee, Yoonji; Yun, Gyoungsu; Lee, Kiwon; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The aim of the paper is current status of treatment for the decommissioning combustible waste in KAERI and for the purpose of the volume reduction and clearance for decommissioning combustible wastes generated by the decommissioning projects. The incineration technology has been selected for the treatment of combustible wastes. About 34 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. Temperature, pressure of major components, stack gas concentration, i. e., SOx, NOx, CO, CO{sub 2} and HCl, and the residual oxygen were measured. Measured major parameters during normal operation were sustained on a stable status within a criteria operation condition. Oxygen enriched air, 22vol. % (dry basis) was used for stable incineration. The volume reduction ratio has achieved about 1/117. The incineration with decommissioning radioactive combustible waste is possible with moderate oxygen enrichment of 22 vol.% (dry basis) into the supply air. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas. The pressure, off-gas flow and temperature of major components remained constant within the range specified. The measures gases and particulate materials in stack were considerably below the regulatory limits. The achieved volume reduction ratio through incineration is about 1/117.

The need for peri-operative supplemental oxygen | Chikungwa ...

African Journals Online (AJOL)

The need for peri-operative supplemental oxygen. M. T. Chikungwa, K. Jonsson. Abstract. (Central African Journal of Medicine: 2002 48 (5-6): 72-73). AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use ...

International co-operation in the field of operational safety

International Nuclear Information System (INIS)

Dupuis, M.C.

1988-10-01

Operational safety in nuclear power plants is without doubt a field where international co-operation is in constant progress. Accounting for over 80 per cent of the 400 reactors in service throughout the world, the menber countries of the OECD Nuclear Energy Agency (NEA) are constantly striving to improve the exchange and use of the wealth of information to be gained not just from power plant accidents and incidents but from the routine operation of these facilities. The Committee on the Safety of Nuclear Installations (CSNI) helps the Steering Committee for Nuclear Energy to meet the NEA's objectives in the safety field, namely: - to promote co-operation between the safety bodies of member countries - to contribute to the safety and regulation of nuclear activities. The CSNI relies on the technical back-up of several different working groups made up of experts appointed by the member countries. For the past three years I have had the honour of chairing Principal Working Group 1 (PWG 1), which deals with operating experience and human factor. It is in this capacity that I will attempt to outline the group's various activities and its findings illustrated by a few examples

[Peroxynitrite effect on the haemoglobin oxygen affinity in vitro in presence of different partial pressure of carbon dioxide].

Science.gov (United States)

Stepuro, T L; Zinchuk, V V

2011-08-01

Peroxynitrite (ONOO-) besides its toxic possesses regulatory action that includes the modulation of oxygen binding properties of blood. The aim of this work was to estimate ONOO- effect on the haemoglobin oxygen affinity (HOA) in vitro in presence of different partial pressure of carbon dioxide (CO2). The ONOO- presence in venous blood in conditions of hypercapnia induced oxyhaemoglobin dissociation curve shift leftward while in hypocapnic conditions the result of a different character was obtained. The revealed effect of ONOO- is realized, possibly, through various modifications ofhaemoglobin whose formation is dependent on the CO2 pressure. The ONOO- influences the HOA in different manner that can be important in regulation of blood oxygenation in lungs and maintenance of oxygen consumption in tissues.

GREENHOUSE GAS EMISSIONS CONTROL BY OXYGEN FIRING IN CIRCULATING FLUIDIZED BED BOILERS: PHASE II--PILOT SCALE TESTING AND UPDATED PERFORMANCE AND ECONOMICS FOR OXYGEN FIRED CFB WITH CO2 CAPTURE

Energy Technology Data Exchange (ETDEWEB)

Nsakala ya Nsakala; Gregory N. Liljedahl; David G. Turek

2004-10-27

Because fossil fuel fired power plants are among the largest and most concentrated producers of CO{sub 2} emissions, recovery and sequestration of CO{sub 2} from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO{sub 2} emissions. In this Phase II study, ALSTOM Power Inc. (ALSTOM) has investigated one promising near-term coal fired power plant configuration designed to capture CO{sub 2} from effluent gas streams for sequestration. Burning fossil fuels in mixtures of oxygen and recirculated flue gas (made principally of CO{sub 2}) essentially eliminates the presence of atmospheric nitrogen in the flue gas. The resulting flue gas is comprised primarily of CO{sub 2}, along with some moisture, nitrogen, oxygen, and trace gases like SO{sub 2} and NO{sub x}. Oxygen firing in utility scale Pulverized Coal (PC) fired boilers has been shown to be a more economical method for CO{sub 2} capture than amine scrubbing (Bozzuto, et al., 2001). Additionally, oxygen firing in Circulating Fluid Bed Boilers (CFB's) can be more economical than in PC or Stoker firing, because recirculated gas flow can be reduced significantly. Oxygen-fired PC and Stoker units require large quantities of recirculated flue gas to maintain acceptable furnace temperatures. Oxygen-fired CFB units, on the other hand, can accomplish this by additional cooling of recirculated solids. The reduced recirculated gas flow with CFB plants results in significant Boiler Island cost savings resulting from reduced component The overall objective of the Phase II workscope, which is the subject of this report, is to generate a refined technical and economic evaluation of the Oxygen fired CFB case (Case-2 from Phase I) utilizing the information learned from pilot-scale testing of this concept. The objective of the pilot-scale testing was to generate detailed technical data needed to establish advanced CFB design requirements and performance when firing coals and

Quantifying the emissions reduction effectiveness and costs of oxygenated gasoline

International Nuclear Information System (INIS)

Lyons, C.E.

1993-01-01

During the fall, winter, and spring of 1991-1992, a measurement program was conducted in Denver, Colorado to quantify the technical and economic effectiveness of oxygenated gasoline in reducing automobile carbon monoxide (CO) emissions. Emissions from 80,000 vehicles under a variety of operating conditions were measured before, during, and after the seasonal introduction of oxygenated gasoline into the region. Gasoline samples were taken from several hundred vehicles to confirm the actual oxygen content of the fuel in use. Vehicle operating conditions, such as cold starts and warm operations, and ambient conditions were characterized. The variations in emissions attributable to fuel type and to operating conditions were then quantified. This paper describes the measurement program and its results. The 1991-1992 Colorado oxygenated gasoline program contributed to a reduction in carbon monoxide (CO) emissions from gasoline-powered vehicles. The measurement program demonstrated that most of the reduction is concentrated in a small percentage of the vehicles that use oxygenated gasoline. The remainder experience little or not reduction in emissions. The oxygenated gasoline program outlays are approximately $25 to $30 million per year in Colorado. These are directly measurable costs, incurred through increased government expenditures, higher costs to private industry, and losses in fuel economy. The measurement program determined the total costs of oxygenated gasoline as an air pollution control strategy for the region. Costs measured included government administration and enforcement, industry production and distribution, and consumer and other user costs. This paper describes the ability of the oxygenated gasoline program to reduce pollution; the overall cost of the program to government, industry, and consumers; and the effectiveness of the program in reducing pollution compared to its costs

Oxygen dependency of epidermal growth factor receptor binding and DNA synthesis of rat hepatocytes

International Nuclear Information System (INIS)

Hirose, Tetsuro; Terajima, Hiroaki; Yamauchi, Akira

1997-01-01

Background/Aims: Changes in oxygen availability modulate replicative responses in several cell types, but the effects on hepatocyte replication remain unclear. We have studied the effects of transient nonlethal hypoxia on epidermal growth factor receptor binding and epidermal growth factor-induced DNA synthesis of rat hepatocytes. Methods: Lactate dehydrogenase activity in culture supernatant, intracellular adenosine triphosphate content, 125 I-epidermal growth factor specific binding, epidermal growth factor receptor protein expression, and 3 H-thymidine incorporation were compared between hepatocytes cultured in hypoxia and normoxia. Results: Hypoxia up to 3 h caused no significant increase in lactate dehydrogenase activity in the culture supernatant, while intracellular adenosine triphosphate content decreased time-dependently and was restored to normoxic levels by reoxygenation (nonlethal hypoxia). Concomitantly, 125 I-epidermal growth factor specific binding to hepatocytes decreased time-dependently (to 54.1% of normoxia) and was restored to control levels by reoxygenation, although 125 I-insulin specific binding was not affected. The decrease in 125 I-epidermal growth factor specific binding was explained by the decrease in the number or available epidermal growth factor receptors (21.37±3.08 to 12.16±1.42 fmol/10 5 cells), while the dissociation constant of the receptor was not affected. The change in the number of available receptors was not considered to be due to receptor degradation-resynthesis, since immuno-detection of the epidermal growth factor receptor revealed that the receptor protein expression did not change during hypoxia and reoxygenation, and since neither actinomycin D nor cycloheximide affected the recovery of 125 I-epidermal growth factor binding by reoxygenation. Inhibition of epidermal growth factor-induced DNA synthesis after hypoxia (to 75.4% of normoxia by 3 h hypoxia) paralleled the decrease in 125 I-epidermal growth factor binding

CO2 maximum in the oxygen minimum zone (OMZ

Directory of Open Access Journals (Sweden)

V. Garçon

2011-02-01

Full Text Available Oxygen minimum zones (OMZs, known as suboxic layers which are mainly localized in the Eastern Boundary Upwelling Systems, have been expanding since the 20th "high CO2" century, probably due to global warming. OMZs are also known to significantly contribute to the oceanic production of N2O, a greenhouse gas (GHG more efficient than CO2. However, the contribution of the OMZs on the oceanic sources and sinks budget of CO2, the main GHG, still remains to be established. We present here the dissolved inorganic carbon (DIC structure, associated locally with the Chilean OMZ and globally with the main most intense OMZs (O2−1 in the open ocean. To achieve this, we examine simultaneous DIC and O2 data collected off Chile during 4 cruises (2000–2002 and a monthly monitoring (2000–2001 in one of the shallowest OMZs, along with international DIC and O2 databases and climatology for other OMZs. High DIC concentrations (>2225 μmol kg−1, up to 2350 μmol kg−1 have been reported over the whole OMZ thickness, allowing the definition for all studied OMZs a Carbon Maximum Zone (CMZ. Locally off Chile, the shallow cores of the OMZ and CMZ are spatially and temporally collocated at 21° S, 30° S and 36° S despite different cross-shore, long-shore and seasonal configurations. Globally, the mean state of the main OMZs also corresponds to the largest carbon reserves of the ocean in subsurface waters. The CMZs-OMZs could then induce a positive feedback for the atmosphere during upwelling activity, as potential direct local sources of CO2. The CMZ paradoxically presents a slight "carbon deficit" in its core (~10%, meaning a DIC increase from the oxygenated ocean to the OMZ lower than the corresponding O2 decrease (assuming classical C/O molar ratios. This "carbon deficit" would be related to regional thermal mechanisms affecting faster O2 than DIC (due to the carbonate buffer effect and occurring upstream in warm waters (e.g., in the Equatorial Divergence

CO2 maximum in the oxygen minimum zone (OMZ)

Science.gov (United States)

Paulmier, A.; Ruiz-Pino, D.; Garçon, V.

2011-02-01

Oxygen minimum zones (OMZs), known as suboxic layers which are mainly localized in the Eastern Boundary Upwelling Systems, have been expanding since the 20th "high CO2" century, probably due to global warming. OMZs are also known to significantly contribute to the oceanic production of N2O, a greenhouse gas (GHG) more efficient than CO2. However, the contribution of the OMZs on the oceanic sources and sinks budget of CO2, the main GHG, still remains to be established. We present here the dissolved inorganic carbon (DIC) structure, associated locally with the Chilean OMZ and globally with the main most intense OMZs (O2Chile during 4 cruises (2000-2002) and a monthly monitoring (2000-2001) in one of the shallowest OMZs, along with international DIC and O2 databases and climatology for other OMZs. High DIC concentrations (>2225 μmol kg-1, up to 2350 μmol kg-1) have been reported over the whole OMZ thickness, allowing the definition for all studied OMZs a Carbon Maximum Zone (CMZ). Locally off Chile, the shallow cores of the OMZ and CMZ are spatially and temporally collocated at 21° S, 30° S and 36° S despite different cross-shore, long-shore and seasonal configurations. Globally, the mean state of the main OMZs also corresponds to the largest carbon reserves of the ocean in subsurface waters. The CMZs-OMZs could then induce a positive feedback for the atmosphere during upwelling activity, as potential direct local sources of CO2. The CMZ paradoxically presents a slight "carbon deficit" in its core (~10%), meaning a DIC increase from the oxygenated ocean to the OMZ lower than the corresponding O2 decrease (assuming classical C/O molar ratios). This "carbon deficit" would be related to regional thermal mechanisms affecting faster O2 than DIC (due to the carbonate buffer effect) and occurring upstream in warm waters (e.g., in the Equatorial Divergence), where the CMZ-OMZ core originates. The "carbon deficit" in the CMZ core would be mainly compensated locally at the

Oxygen isotope partitioning between rhyolitic glass/melt and CO2: An experimental study at 550-950 degrees C and 1 bar

International Nuclear Information System (INIS)

Palin, J.M.; Epstein, S.; Stolper, E.M.

1996-01-01

Oxygen isotope partitioning between gaseous CO 2 and a natural rhyolitic glass and melt (77.7 wt% SiO 2 , 0.16 wt% H 2 O total ) has been measured at 550-950 degrees C and approximately 1 bar. Equilibrium oxygen isotope fractionation factors (α CO2-rhyolite = ( 18 O/ 16 O) rhyolite ) determined in exchange experiments of 100-255 day duration. These values agree well with predictions based on experimentally determined oxygen isotope fractionation factors for CO 2 -silica glass and CO 2 -albitic glass/melt, if the rhyolitic glass is taken to be a simple mixture of normative silica and alkali feldspar components. The results indicate that oxygen isotope partitioning in felsic glasses and melts can be modeled by linear combinations of endmember silicate constituents. Rates of oxygen isotope exchange observed in the partitioning experiments are consistent with control by diffusion of molecular H 2 O dissolved in the glass/melt and are three orders of magnitude faster than predicted for rate control solely by diffusion of dissolved molecular CO 2 under the experimental conditions. Additional experiments using untreated and dehydrated (0.09 wt% H 2 O total ) rhyolitic glass quantatively support these interpretations. We conclude that diffusive oxygen isotope exchange in rhyolitic glass/melt, and probably other polymerized silicate materials, it controlled by the concentrations and diffusivities of dissolved oxygen-bearing volatile species rather than diffusion of network oxygen under all but the most volatile-poor conditions. 25 refs., 6 figs., 1 tab

Airborne Measurements of Atmospheric Pressure made Using an IPDA Lidar Operating in the Oxygen A-Band

Science.gov (United States)

Riris, Haris; Abshire, James B.; Stephen, Mark; Rodriquez, Michael; Allan, Graham; Hasselbrack, William; Mao, Jianping

2012-01-01

We report airborne measurements of atmospheric pressure made using an integrated path differential absorption (IPDA) lidar that operates in the oxygen A-band near 765 nm. Remote measurements of atmospheric temperature and pressure are needed for NASA s Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission to measure atmospheric CO2. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve our predictions of climate change. The goal of ASCENDS is to determine the CO2 dry mixing ratio with lidar measurements from space at a level of 1 ppm. Analysis to date shows that with current weather models, measurements of both the CO2 column density and the column density of dry air are needed. Since O2 is a stable molecule that uniformly mixed in the atmosphere, measuring O2 absorption in the atmosphere can be used to infer the dry air density. We have developed an airborne (IPDA) lidar for Oxygen, with support from the NASA ESTO IIP program. Our lidar uses DFB-based seed laser diodes, a pulsed modulator, a fiber laser amplifier, and a non-linear crystal to generate wavelength tunable 765 nm laser pulses with a few uJ/pulse energy. The laser pulse rate is 10 KHz, and average transmitted laser power is 20 mW. Our lidar steps laser pulses across a selected line O2 doublet near 764.7 nm in the Oxygen A-band. The direct detection lidar receiver uses a 20 cm diameter telescope, a Si APD detector in Geiger mode, and a multi-channel scalar to detect and record the time resolved laser backscatter in 40 separate wavelength channels. Subsequent analysis is used to estimate the transmission line shape of the doublet for the laser pulses reflected from the ground. Ground based data analysis allows averaging from 1 to 60 seconds to increase SNR in the transmission line shape of the doublet. Our retrieval algorithm fits the expected O2 lineshapes against the measurements and

The acyl-CoA binding protein affects Monascus pigment production in Monascus ruber CICC41233.

Science.gov (United States)

Long, Chuannan; Liu, Mengmeng; Chen, Xia; Wang, Xiaofang; Ai, Mingqiang; Cui, Jingjing; Zeng, Bin

2018-02-01

The present study verified whether acyl-coenzyme A (acyl-CoA)-binding protein (ACBP) affected the production of Monascus pigments (MPs) in Monascus ruber CICC41233 (MrACBP). Phylogenetic analysis revealed that the cloned Mracbp gene, which encoded the MrACBP protein, exhibited the closest match (99% confidence level) to the gene from Penicilliopsis zonata . The MrACBP and maltose-binding protein (MBP) were simultaneously expressed in Escherichia coli Rosetta DE3 in the form of a fusion protein. The microscale thermophoresis binding assay revealed that the purified MBP-MrACBP exhibited a higher affinity for myristoyl-CoA (Kd = 88.16 nM) than for palmitoyl-CoA (Kd = 136.07 nM) and octanoyl-CoA (Kd = 270.9 nM). Further, the Mracbp gene was homologously overexpressed in M. ruber CICC41233, and a positive transformant M. ruber ACBP5 was isolated. The fatty acid myristic acid in M. ruber ACBP5 was lower than that in the parent strain M. ruber CICC41233. However, when compared with the parent strain, the production of total MPs, water-soluble pigment, and ethanol-soluble pigment in M. ruber ACBP5 increased by 11.67, 9.80, and 12.70%, respectively, after 6 days. The relative gene expression level, as determined by a quantitative real-time polymerase chain reaction analysis, of the key genes acbp , pks , mppr1 , fasA , and fasB increased by 4.03-, 3.58-, 1.67-, 2.11-, and 2.62-fold after 6 days. These data demonstrate the binding preference of MrACBP for myristoyl-CoA, and its influence on MPs production.

Promoting regional energy co-operation in South Asia

International Nuclear Information System (INIS)

Srivastava, Leena; Misra, Neha

2007-01-01

Energy is a key ingredient of the socio-economic development of any region. South Asia is not only one of the fastest growing regions in the world; it is also one of the poorest, which thus puts energy at the very heart of the development process in the region. This paper looks at the challenges faced by the South Asia sub-region for economic co-operation (SASEC) comprised of Bangladesh, Bhutan, India and Nepal, and also at the role of greater regional energy co-operation therein. The region is characterized by pressures of growing economies and increasing population. While the per capita energy consumption is one of the lowest in the world, energy intensity continues to be very high. A large portion of the population lacks access to modern sources of energy and depends on traditional sources that are not only inefficient but also have severe health and environmental problems associated with them. Increasing oil import dependency and huge investment needs for energy market development pose a further challenge. The region has a good resource potential and tremendous scope for energy co-operation, which can play a key role in addressing many of these energy security concerns and in putting it on the path of sustainable development. It is ironic that the record in the area has been so limited and that too in the most basic form of co-operation, i.e. bilateral arrangements between countries. This paper puts forth a multi-pronged strategy for sub-regional energy co-operation encompassing softer options aimed at confidence building to more substantial and larger scale co-operation efforts. Delays in decision making to ensure stronger and mutually beneficial co-operation efforts are associated with high costs not only to the energy sector but also for the entire development agenda. With the precarious energy situation in the region and unprecedented increases in international oil prices seen in recent times, it is high time for policy makers, financing institutions, NGOs

Co-operative approaches to regulation

National Research Council Canada - National Science Library

Huigen, Hans; Organisation for Economic Co-operation and Development

1997-01-01

The case studies in this occasional paper are about ways in which governments and businesses are seeking to address economic and social problems by using new forms of co-operation that are different...

Operating experience feedback report -- Pressure locking and thermal binding of gate valves

International Nuclear Information System (INIS)

Hsu, C.

1993-03-01

The potential for valve inoperability caused by pressure locking and thermal binding has been known for many years in the nuclear industry. Pressure locking or thermal binding is a common-mode failure mechanism that can prevent a gate valve from opening, and could render redundant trains of safety systems or multiple safety systems inoperable. In spite of numerous generic communications issued in the past by the Nuclear Regulatory Commission (NRC) and industry, pressure locking and thermal binding continues to occur to gate valves installed in safety-related systems of both boding water reactors (BWRs) and pressurized water reactors (PWRs). The generic communications to date have not led to effective industry action to fully identify, evaluate, and correct the problem. This report provides a review of operating events involving these failure mechanisms. As a result of this review this report: (1) identifies conditions when the failure mechanisms have occurred, (2) identifies the spectrum of safety systems that have been subjected to the failure mechanisms, and (3) identifies conditions that may introduce the failure mechanisms under both normal and accident conditions. On the basis of the evaluation of the operating events, the Office for Analysis and Evaluation of Operational Data (AEOD) of the NRC concludes that the binding problems with gate valves are an important safety issue that needs priority NRC and industry attention. This report also provides AEOD's recommendation for actions to effectively prevent the occurrence of valve binding failures

Performance Measurement Using Balanced Scorecard Concept On Co-Operatives Implication In Indonesia

Directory of Open Access Journals (Sweden)

Ernita

2015-08-01

Full Text Available Abstract This study aims to apply the concept of balanced scorecards in measurement of co-operatives performance based on vision and mission. So far the assessment of co-operative performance in Indonesia is not take into account the social hold co-operative while co-operatives carrying a dual mission. Research conducted in in North Sumatera Province in Indonesia. The sample consisting of one hundred co-operatives that are still active run annual members meeting. Co-operative performance was assessed based on its fourth perspective i.e. membership financial internal process and learning amp growth. The indicator key of cooperative performance was determined by taking into account the performance assessment on co-operatives as articulated of State Minister for Co-operatives and SMEs No.129KEPMKUMKMXI2002 and the regulations of the State Minister for Co-operatives and SME No.06PerM.KUKMV2006. Therefore this research were contributed a method in assessing co-operative performance using Balanced Scorecard concept with the four perspective namely membership perspective financial perspective internal process perspective and learning amp growth perspective.

Electrical control of exchange bias via oxygen migration across CoO-ZnO nanocomposite barrier

Science.gov (United States)

Li, Q.; Yan, S. S.; Xu, J.; Li, S. D.; Zhao, G. X.; Long, Y. Z.; Shen, T. T.; Zhang, K.; Zhang, J.

2016-12-01

We proposed a nanocomposite barrier CoO-ZnO for magnetism manipulation in Co/CoO-ZnO/Ag heterojunctions. Both electrical control of magnetism and resistive switching were realized in this junction. An electrical tunable exchange bias of CoO1-v (v denotes O vacancies) on Co films was realized using voltages below 1 volt. The magnetism modulation associated with resistive switching can be attributed to the oxygen ions migration between the insulating CoO1-v layer and the semiconductive ZnO1-v layer, which can cause both ferromagnetic phase and resistance switching of CoO1-v layer.

Structural Bases for the Regulation of CO Binding in the Archaeal Protoglobin from Methanosarcina acetivorans.

Directory of Open Access Journals (Sweden)

Lesley Tilleman

Full Text Available Studies of CO ligand binding revealed that two protein states with different ligand affinities exist in the protoglobin from Methanosarcina acetivorans (in MaPgb*, residue Cys(E20101 was mutated to Ser. The switch between the two states occurs upon the ligation of MaPgb*. In this work, site-directed mutagenesis was used to explore the role of selected amino acids in ligand sensing and stabilization and in affecting the equilibrium between the "more reactive" and "less reactive" conformational states of MaPgb*. A combination of experimental data obtained from electronic and resonance Raman absorption spectra, CO ligand-binding kinetics, and X-ray crystallography was employed. Three amino acids were assigned a critical role: Trp(60B9, Tyr(61B10, and Phe(93E11. Trp(60B9 and Tyr(61B10 are involved in ligand stabilization in the distal heme pocket; the strength of their interaction was reflected by the spectra of the CO-ligated MaPgb* and by the CO dissociation rate constants. In contrast, Phe(93E11 is a key player in sensing the heme-bound ligand and promotes the rotation of the Trp(60B9 side chain, thus favoring ligand stabilization. Although the structural bases of the fast CO binding rate constant of MaPgb* are still unclear, Trp(60B9, Tyr(61B10, and Phe(93E11 play a role in regulating heme/ligand affinity.

DNA incision evaluation, binding investigation and biocidal screening of Cu(II), Ni(II) and Co(II) complexes with isoxazole Schiff bases.

Science.gov (United States)

Ganji, Nirmala; Chityala, Vijay Kumar; Marri, Pradeep Kumar; Aveli, Rambabu; Narendrula, Vamsikrishna; Daravath, Sreenu; Shivaraj

2017-10-01

Two new series of binary metal complexes [M(L 1 ) 2 ] and [M(L 2 ) 2 ] where, M=Cu(II), Ni(II) & Co(II) and L 1 =4-((3,4-dimethylisoxazol-5-ylimino)methyl)benzene-1,3-diol; L 2 =2-((3,4-dimethylisoxazol-5-ylimino)methyl)-5-methoxyphenol were synthesized and characterized by elemental analysis, 1 H NMR, 13 C NMR, FT-IR, ESI mass, UV-Visible, magnetic moment, ESR, SEM and powder XRD studies. Based on these results, a square planar geometry is assigned for all the metal complexes where the Schiff base acts as uninegatively charged bidentate chelating agent via the hydroxyl oxygen and azomethine nitrogen atoms. DNA binding studies of all the complexes with calf thymus DNA have been comprehensively investigated using electronic absorption spectroscopy, fluorescence quenching and viscosity studies. The oxidative and photo cleavage affinity of metal complexes towards supercoiled pBR322 DNA has been ascertained by agarose gel electrophoresis assay. From the results, it is observed that all the metal complexes bind effectively to CT-DNA via an intercalative mode of binding and also cleave pBR322 DNA in a promising manner. Further the Cu(II) complexes have shown better binding and cleavage properties towards DNA. The antimicrobial activities of the Schiff bases and their metal complexes were studied on bacterial and fungal strains and the results denoted that the complexes are more potent than their Schiff base ligands. Copyright © 2017 Elsevier B.V. All rights reserved.

Active and inactive enhancers co-operate to exert localized and long-range control of gene regulation

Science.gov (United States)

Proudhon, Charlotte; Snetkova, Valentina; Raviram, Ramya; Lobry, Camille; Badri, Sana; Jiang, Tingting; Hao, Bingtao; Trimarchi, Thomas; Kluger, Yuval; Aifantis, Iannis; Bonneau, Richard; Skok, Jane A

2016-01-01

V(D)J recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR) loci in a lineage and stage specific manner. Unexpectedly we find that both active and inactive AgR enhancers co-operate to disseminate their effects in a localized and long-range manner. Here we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. We further establish that in T cells long-range contact and co-operation between the inactive Igk enhancer, MiEκ and the active Tcrb enhancer, Eβ, alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage and stage specific control. PMID:27239026

Facile preparation of efficient electrocatalysts for oxygen reduction reaction: One-dimensional meso/macroporous cobalt and nitrogen Co-doped carbon nanofibers

Science.gov (United States)

Yoon, Ki Ro; Choi, Jinho; Cho, Su-Ho; Jung, Ji-Won; Kim, Chanhoon; Cheong, Jun Young; Kim, Il-Doo

2018-03-01

Efficient electrocatalyst for oxygen reduction reaction (ORR) is an essential component for stable operation of various sustainable energy conversion and storage systems such as fuel cells and metal-air batteries. Herein, we report a facile preparation of meso/macroporous Co and N co-doped carbon nanofibers (Co-Nx@CNFs) as a high performance and cost-effective electrocatalyst toward ORR. Co-Nx@CNFs are simply obtained from electrospinning of Co precursor and bicomponent polymers (PVP/PAN) followed by temperature controlled carbonization and further activation step. The prepared Co-Nx@CNF catalyst carbonized at 700 °C (Co-Nx@CNF700) shows outstanding ORR performance, i.e., a low onset potential (0.941 V) and half wave potential (0.814 V) with almost four-electron transfer pathways (n= 3.9). In addition, Co-Nx@CNF700 exhibits a superior methanol tolerance and higher stability (>70 h) in Zn-air battery in comparison with Pt/C catalyst (∼30 h). The outstanding performance of Co-Nx@CNF700 catalysts is attributed to i) enlarged surface area with bimodal porosity achieved by leaching of inactive species, ii) increase of exposed ORR active Co-Nx moieties and graphitic edge sites, and iii) enhanced electrical conductivity and corrosion resistance due to the existence of numerous graphitic flakes in carbon matrix.

Artificial oxygen transport protein

Science.gov (United States)

Dutton, P. Leslie

2014-09-30

This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

Binding CO2 from Air by a Bulky Organometallic Cation Containing Primary Amines.

Science.gov (United States)

Luo, Yang-Hui; Chen, Chen; Hong, Dan-Li; He, Xiao-Tong; Wang, Jing-Wen; Ding, Ting; Wang, Bo-Jun; Sun, Bai-Wang

2018-03-21

The organometallic cation 1 (Fe(bipy-NH 2 ) 3 2+ , bipy-NH 2 = 4,4'-diamino-2,2'-bipyridine), which was constructed in situ in solution, can bind CO 2 from air effectively with a stoichiometric ratio of 1:4 (1/CO 2 ), through the formation of "H-bonded CO 2 " species: [CO 2 -OH-CO 2 ] - and [CO 2 -CO 2 -OH] - . These two species, along with the captured individual CO 2 molecules, connected 1 into a novel 3D (three-dimensional) architecture, that was crystal 1·2(OH - )·4(CO 2 ). The adsorption isotherms, recycling investigations, and the heat capacity of 1 have been investigated; the results revealed that the organometallic cation 1 can be recycled at least 10 times for the real-world CO 2 capture applications. The strategies presented here may provide new hints for the development of new alkanolamine-related absorbents or technologies for CO 2 capture and sequestration.

Experience of more than 1000 h of operation with oxygen carriers and solid biomass at large scale

International Nuclear Information System (INIS)

Berdugo Vilches, Teresa; Lind, Fredrik; Rydén, Magnus; Thunman, Henrik

2017-01-01

Highlights: • First large scale experience (MW) of biomass combustion at CLC-relevant conditions. • Manganese and ilmenite were applied successfully at semi-industrial scale. • 60% combustion under challenging conditions: 830 °C, over-bed fuel feeding. • Volatiles conversion limited by mixing to a significant extent. - Abstract: This paper presents an overview of the experience gained from operating a dual fluidized bed system with oxygen carriers and biomass for more than 1000 h. The tests were carried out in the Chalmers boiler/gasifier loop (with inputs of 12 MW_t_h and 2–4 MW_t_h, respectively), which is 2–4 orders of magnitude larger than most existing CLC units. Coarse biomass particles (i.e., commercial wood pellets) were fed as fuel onto the surface of a mild fluidized bed. This limits significantly the contacts between the volatiles and the oxygen carrier particles, as the flotsam fuel tends to remain on the surface of the bed while the volatiles are released. The oxygen carrier materials tested were ilmenite and a manganese ore. The influences on biomass conversion of fluidization velocity, fuel feeding rate, and circulation rate of the bed material were investigated. Both bed materials efficiently transported oxygen between the reactors, achieving up to 60% combustion of the gases released in the reactor at a relatively low temperature, i.e., 830 °C. The ilmenite outperformed the manganese ore under the conditions investigated. With oxygen carriers, the yield of hydrocarbons heavier than benzene was in the range of 10–11 g/N m"3, which was 70% (w/w) lower than that obtained in a reference case with silica-sand as the bed material. The conversion of volatile species to CO_2 was limited by gas-solids mixing, which could be enhanced by altering the fluidization velocity. The circulation rate of the bed material and the fuel feeding rate were found to have important influences on the rate of char gasification. Given the relatively low

[Measurement and analysis of micropore aeration system's oxygenating ability under operation condition in waste water treatment plant].

Science.gov (United States)

Wu, Yuan-Yuan; Zhou, Xiao-Hong; Shi, Han-Chang; Qiu, Yong

2013-01-01

Using the aeration pool in the fourth-stage at Wuxi Lucun Waste Water Treatment Plant (WWTP) as experimental setup, off-gas method was selected to measure the oxygenating ability parameters of micropore aerators in a real WWTP operating condition and these values were compared with those in fresh water to evaluate the performance of the micropore aerators. Results showed that the micropore aerators which were distributed in different galleries of the aeration pool had significantly different oxygenating abilities under operation condition. The oxygenating ability of the micropore aerators distributed in the same gallery changed slightly during one day. Comparing with the oxygenating ability in fresh water, it decreased a lot in the real aeration pool, in more details, under the real WWTP operating condition, the values of oxygen transfer coefficient K(La) oxygenation capacity OC and oxygen utilization E(a) decreased by 43%, 57% and 76%, respectively.

Effect of oxygen stoichiometry on the electrical properties of La0.5Sr0.5CoO3 electrodes

International Nuclear Information System (INIS)

Madhukar, S.; Aggarwal, S.; Dhote, A.M.; Ramesh, R.; Krishnan, A.; Keeble, D.; Poindexter, E.

1997-01-01

We report on the metal-insulator transition of La 0.5 Sr 0.5 CoO 3 thin films deposited by pulsed laser ablation on LaAlO 3 substrates. The films were cooled in oxygen partial pressures between 760 and 10 -5 Torr and electrical resistivity of the films was measured as a function of cooling oxygen pressure. La 0.5 Sr 0.5 CoO 3 films changed from metallic to insulating behavior depending on their oxygen content. A defect model has been proposed to explain this transition and the change in conductivity is related to the change in the oxidation state of the cobalt ions. The model explains the relationship between oxygen partial pressure and electrical conductivity in La 0.5 Sr 0.5 CoO 3 , which describes the experimental dependence reasonably well. Positron annihilation studies were also done on the same set of samples and the S parameter was seen to increase by 8% from a fully oxygenated sample to a sample cooled in 10 -5 Torr. copyright 1997 American Institute of Physics

Oxygen order-disorder phase transition in PrBaCo2O5.48 at high temperature

International Nuclear Information System (INIS)

Streule, S.; Podlesnyak, A.; Pomjakushina, E.; Conder, K.; Sheptyakov, D.; Medarde, M.; Mesot, J.

2006-01-01

We have investigated the PrBaCo 2 O 5.48 compound by means of neutron powder diffraction at temperatures 300K OD =776K, which we associate with an oxygen order-disorder transition: the well-known room temperature ordered crystal structure, in which slabs of CoO 6 octahedra and CoO 5 pyramids interleave (Pmmm symmetry) gets lost at temperatures T>T OD , resulting in a statistical distribution of octahedra and pyramids in the sample. The new phase can be described by the tetragonal P4/mmm space group. The transition is caused by displacement of apical oxygen ions and is an indication that ionic conductivity, which has been observed in 3D cobaltites, may also exist in layered cobaltites

Binding energy and preferred adsorption sites of CO on gold and silver-gold cluster cations: adsorption kinetics and quantum chemical calculations.

Science.gov (United States)

Neumaier, Marco; Weigend, Florian; Hampe, Oliver; Kappes, Manfred M

2008-01-01

We revisit the reactivity of trapped pure gold (Au(n)+, n cations (Ag(m)Au(n)+, m + n carbon monoxide as studied in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. The experimental results are discussed in terms of ab initio computations which provide a comprehensive picture of the chemical binding behaviour (like binding energy, adsorption sites, associated vibrational frequencies) of CO to the noble metal as a function of cluster size and composition. Starting from results for pure gold cluster cations for which an overall decrease of CO binding energy with increasing cluster size was experimentally observed--from about 1.09 +/- 0.1 eV (for n = 6) to below 0.65 +/- 0.1 eV (for n > 26) we demonstrate that metal--CO bond energies correlate with the total electron density and with the energy of the lowest unoccupied molecular orbital (LUMO) on the bare metal cluster cation as obtained by density functional theory (DFT) computations. This is a consequence of the predominantly sigma-donating character of the CO-M bond. Further support for this concept is found by contrasting the predictions of binding energies to the experimental results for small alloy cluster cations (Ag(m)Au(n)+, 4 < m + n < 7) as a function of composition. Here, binding energy drops with increasing silver content, while CO still binds always in a head-on fashion to a gold atom. Finally we show how the CO stretch frequency of Ag(m)Au(n)CO+ may be used to identify possible adsorption sites and pre-screen favorable isomers.

SMEs and their co-operation with academia.

Science.gov (United States)

Antoine, Jean Michel; Strömqvist, Mats

2005-01-01

Co-operation between SMEs and Academia can be a win-win situation when each partner understands the constraints of the other. SMEs are often leaders in innovation; therefore more ready to share interest in research. They are flexible and dynamic. They need a short feed-back to sustain their co-operation. Academia is often more long-term oriented and more question- than answer-oriented. A code of conduct can ease the relationship because it can anticipate the potential problems.

Unraveling the facet-dependent and oxygen vacancy role for ethylene hydrogenation on Co_3O_4 (110) surface: A DFT+U study

International Nuclear Information System (INIS)

Zhang, Yong-Chao; Pan, Lun; Lu, Jinhui; Song, Jiajia; Li, Zheng; Zhang, Xiangwen; Wang, Li; Zou, Ji-Jun

2017-01-01

Highlights: • The mechanism of ethylene hydrogenation on perfect and oxygen defective Co_3O_4(110) is investigated by using DFT + U. • Oxygen vacancy promotes ethylene hydrogenation thermodynamically and kinetically. • The Co3O4 (110) facet is more active than the (111) one for ethylene hydrogenation. - Abstract: Crystal facet engineering and defect engineering are both critical strategies to improve the catalytic hydrogenation performance of catalyst. Herein, ethylene hydrogenation on the perfect and oxygen defective Co_3O_4(110) surfaces has been studied by using periodic density functional theory calculations. The results are compared with that on Co_3O_4(111) surface to clarify the problem of which facet for Co_3O_4 is more reactive, and to illuminate the role of oxygen vacancy. The low oxygen vacancy formation energy suggests that Co_3O_4(110) surface with defective site is easily formed. The whole mechanism of H_2 dissociation and stepwise hydrogenation of ethylene to ethane is examined, and the most favorable pathway is heterolytic dissociation of H_2 follows two stepwise hydrogenation of ethylene process. The results show that ethyl hydrogenation to ethane on perfect Co_3O_4(110) surface is the rate limiting step with an activation energy of 1.19 eV, and the presence of oxygen vacancy strongly reduces the activation energies of main elementary steps, and the activation energy of rate limiting step is only 0.47 eV. Compared with that on Co_3O_4(111), ethylene hydrogenation is preferred on Co_3O_4(110) surface. Therefore, Co_3O_4 with exposed (110) facet is predicted as an excellent catalyst for ethylene hydrogenation.

Electrochemical investigations of Co3Fe-RGO as a bifunctional catalyst for oxygen reduction and evolution reactions in alkaline media

Science.gov (United States)

Kumar, Surender; Kumar, Divyaratan; Kishore, Brij; Ranganatha, Sudhakar; Munichandraiah, Nookala; Venkataramanan, Natarajan S.

2017-10-01

Nanoparticles of Co3Fe alloy is prepared on reduced graphene oxide (RGO) sheets by modified polyol method. Synthesized alloy particles are characterized by various physicochemical techniques. TEM and SEM pictures showed homogeneously dispersed alloy nanoparticles on the RGO sheets. Electrochemistry of alloy nanoparticles is investigated in alkaline medium. The result shows that oxygen evaluation reaction (OER) activity of Co3Fe-RGO is higher than Pt-black particles. RDE studies in alkaline medium shows that oxygen reduction reaction (ORR) follow four electron pathway. It is suggest that Co3Fe-RGO is an efficient non-precious catalyst for oxygen (ORR/OER) reactions in alkaline electrolyte for PEMFC applications.

Why do health and social care providers co-operate?

Science.gov (United States)

van Raak, Arno; Paulus, Aggie; Mur-Veeman, Ingrid

2005-09-28

Within Europe, although there are numerous examples of poor co-ordination in the delivery of integrated care, many providers do co-operate. We wanted to know why providers are moved to co-operate. In terms of systematic research, this is a new field; researchers have only begun to theorise about the rationales for co-operation. Practically, the issue of achieving co-operation attracts much attention from policymakers. Understanding the reasons for co-operation is a prerequisite for developing effective policy in support of integrated care. Our aim is to explore the comparative validity of different theoretical perspectives on the reasons for co-operation, to indicate directions for further study and for policy making. We used data from three successive studies to perform pattern matching with six established theoretical perspectives: transaction costs economics, strategic choice theory, resource dependence theory, learning theory, stakeholder theory and institutional theory. Insights from the studies were compared for validating purposes (triangulation). The first study concerned the evaluation of the Dutch 'National Home Health Care Programme' according to the case study methodology. The second and third studies were surveys among project directors: questionnaires were based on the concepts derived from the first study. Researchers should combine normative institutional theory, resource dependence theory and stakeholder theory into one perspective, in order to study relationship formation in health and social care. The concept of institutions (rules) is the linchpin between the theories. Policy makers must map the institutions of stakeholders and enable integrated care policy to correspond with these institutions as much as possible.

Oxygen isotope systematics of chondrules in the Murchison CM2 chondrite and implications for the CO-CM relationship

Science.gov (United States)

Chaumard, Noël; Defouilloy, Céline; Kita, Noriko T.

2018-05-01

High-precision oxygen three-isotope measurements of olivine and pyroxene were performed on 29 chondrules in the Murchison CM2 chondrite by secondary ion mass spectrometry (SIMS). The oxygen isotope ratios of analyzed chondrules all plot very close to the primitive chondrule minerals (PCM) line. In each of 24 chondrules, the olivine and/or pyroxene grains analyzed show indistinguishable oxygen isotope ratios. Exceptions are minor occurrences of isotopically distinguished relict olivine grains, which were found in nine chondrules. The isotope homogeneity of these phenocrysts is consistent with a co-magmatic crystallization of olivine and pyroxene from the final chondrule melts and a significant oxygen isotope exchange between the ambient gas and the melts. Homogeneous type I chondrules with Mg#'s of 98.9-99.5 have host chondrule Δ17O values ranging from -6.0‰ to -4.1‰, with one exception (Δ17O: -1.2‰; Mg#: 99.6). Homogeneous chondrules with Mg#'s poor H2O ice (∼0.3-0.4× the CI dust; Δ17O > 0‰) and at dust enrichments of ∼300-2000×. Regarding the Mg# and oxygen isotope ratios, the chondrule populations sampled by CM and CO chondrites are similar and indistinguishable. The similarity of these 16O-rich components in CO and CM chondrites is also supported by the common Fe/Mn ratio of olivine in type II chondrules. Although they accreted similar high-temperature silicates, CO chondrites are anhydrous compared to CM chondrites, suggesting they derived from different parent bodies formed inside and outside the snow line, respectively. If chondrules in CO and CM chondrites formed at the same disk locations but the CM parent body accreted later than the CO parent body, the snow line might have crossed the common chondrule-forming region towards the Sun between the time of the CO and CM parent bodies accretion.

Nordic Model of Subregional Co-Operation

Directory of Open Access Journals (Sweden)

Grzela Joanna

2017-12-01

Full Text Available Nordic co-operation is renowned throughout the world and perceived as the collaboration of a group of countries which are similar in their views and activities. The main pillars of the Nordic model of co-operation are the tradition of constitutional principles, activity of public movements and organisations, freedom of speech, equality, solidarity, and respect for the natural environment. In connection with labour and entrepreneurship, these elements are the features of a society which favours efficiency, a sense of security and balance between an individual and a group. Currently, the collaboration is a complex process, including many national, governmental and institutional connections which form the “Nordic family”.

Advancing regional co-operation in Africa

International Nuclear Information System (INIS)

Maksoudi, M.

1991-01-01

The IAEA's regional co-operation programme in Africa was initiated in 1983, with two regional projects dealing with hydrology and insect physiology and biochemistry. The paper describes the structure of this Regional Programme, the sources of finance and the projects currently in operation in agriculture and hydrology. 1 fig., 1 tab

Securing co-operation from persons supplying statistical data

Science.gov (United States)

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

Technical co-operation report for 2000. Report by the Director General

International Nuclear Information System (INIS)

2001-01-01

This report covers three separate topics. Part one fulfills the Agency's obligation under the General Conference resolution GC(44)/RES/18 to report on the Strengthening of Technical Co-operation. It covers the period from 1 April 2000 to 31 March 2001. The report examines the finalization of the 2001-2002 technical co-operation programme and several key concepts of the Technical Co-operation Strategy such as Partners in Development, Technical Co-operation among Developing Countries, and the continuing evolution of Regional Resource Centres. Reflecting an important trend in the technical co-operation programme, which was mandated by the General Conference, the report describes the results achieved in several programmes in least developed countries. Part two reports on the major achievements of the technical co-operation programme in 2000 in the different regions of the world. Part three presents a summary of the financial and non-financial parameters of the technical co-operation programme. The supplement to the report provides a more detailed review of resources and contributions, disbursements and non-financial indicators

Technical co-operation report for 2000. Report by the Director General

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This report covers three separate topics. Part one fulfills the Agency's obligation under the General Conference resolution GC(44)/RES/18 to report on the Strengthening of Technical Co-operation. It covers the period from 1 April 2000 to 31 March 2001. The report examines the finalization of the 2001-2002 technical co-operation programme and several key concepts of the Technical Co-operation Strategy such as Partners in Development, Technical Co-operation among Developing Countries, and the continuing evolution of Regional Resource Centres. Reflecting an important trend in the technical co-operation programme, which was mandated by the General Conference, the report describes the results achieved in several programmes in least developed countries. Part two reports on the major achievements of the technical co-operation programme in 2000 in the different regions of the world. Part three presents a summary of the financial and non-financial parameters of the technical co-operation programme. The supplement to the report provides a more detailed review of resources and contributions, disbursements and non-financial indicators.

Heterojunction-Assisted Co3 S4 @Co3 O4 Core-Shell Octahedrons for Supercapacitors and Both Oxygen and Carbon Dioxide Reduction Reactions.

Science.gov (United States)

Yan, Yibo; Li, Kaixin; Chen, Xiaoping; Yang, Yanhui; Lee, Jong-Min

2017-12-01

Expedition of electron transfer efficiency and optimization of surface reactant adsorption products desorption processes are two main challenges for developing non-noble catalysts in the oxygen reduction reaction (ORR) and CO 2 reduction reaction (CRR). A heterojunction prototype on Co 3 S 4 @Co 3 O 4 core-shell octahedron structure is established via hydrothermal lattice anion exchange protocol to implement the electroreduction of oxygen and carbon dioxide with high performance. The synergistic bifunctional catalyst consists of p-type Co 3 O 4 core and n-type Co 3 S 4 shell, which afford high surface electron density along with high capacitance without sacrificing mechanical robustness. A four electron ORR process, identical to the Pt catalyzed ORR, is validated using the core-shell octahedron catalyst. The synergistic interaction between cobalt sulfide and cobalt oxide bicatalyst reduces the activation energy to convert CO 2 into adsorbed intermediates and hereby enables CRR to run at a low overpotential, with formate as the highly selective main product at a high faraday efficiency of 85.3%. The remarkable performance can be ascribed to the synergistic coupling effect of the structured co-catalysts; heterojunction structure expedites the electron transfer efficiency and optimizes surface reactant adsorption product desorption processes, which also provide theoretical and pragmatic guideline for catalyst development and mechanism explorations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sorbent-based Oxygen Production for Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Sethi, Vijay [Western Research Inst. (WRI), Laramie, WY (United States)

2017-01-31

Project DE-FE0024075 deals with the development of a moderate-temperature sorbent-based oxygen production technology. Sorbent-based oxygen production process utilizes oxygen-storage properties of Perovskites to (1) adsorb oxygen from air in a solid sorbent, and (2) release the adsorbed oxygen into a sweep gas such as CO₂ and/or steam for gasification systems or recycled flue gas for oxy-combustion systems. Pure oxygen can be produced by the use of vacuum instead of a sweep gas to affect the pressure swing. By developing more efficient and stable, higher sorption capacity, newer class of materials operating at moderate temperatures this process represents a major advancement in air separation technology. Newly developed perovskite ceramic sorbent materials with order-disorder transition have a higher O₂ adsorption capacity, potentially 200 °C lower operating temperatures, and up to two orders of magnitude faster desorption rates than those used in earlier development efforts. The performance advancements afforded by the new materials lead to substantial savings in capital investment and operational costs. Cost of producing oxygen using sorbents could be as much as 26% lower than VPSA and about 13% lower than a large cryogenic air separation unit. Cost advantage against large cryogenic separation is limited because sorbent-based separation numbers up sorbent modules for achieving the larger capacity.

B cell recognition of the conserved HIV-1 co-receptor binding site is altered by endogenous primate CD4.

Directory of Open Access Journals (Sweden)

Mattias N E Forsell

2008-10-01

Full Text Available The surface HIV-1 exterior envelope glycoprotein, gp120, binds to CD4 on the target cell surface to induce the co-receptor binding site on gp120 as the initial step in the entry process. The binding site is comprised of a highly conserved region on the gp120 core, as well as elements of the third variable region (V3. Antibodies against the co-receptor binding site are abundantly elicited during natural infection of humans, but the mechanism of elicitation has remained undefined. In this study, we investigate the requirements for elicitation of co-receptor binding site antibodies by inoculating rabbits, monkeys and human-CD4 transgenic (huCD4 rabbits with envelope glycoprotein (Env trimers possessing high affinity for primate CD4. A cross-species comparison of the antibody responses showed that similar HIV-1 neutralization breadth was elicited by Env trimers in monkeys relative to wild-type (WT rabbits. In contrast, antibodies against the co-receptor site on gp120 were elicited only in monkeys and huCD4 rabbits, but not in the WT rabbits. This was supported by the detection of high-titer co-receptor antibodies in all sera from a set derived from human volunteers inoculated with recombinant gp120. These findings strongly suggest that complexes between Env and (high-affinity primate CD4 formed in vivo are responsible for the elicitation of the co-receptor-site-directed antibodies. They also imply that the naïve B cell receptor repertoire does not recognize the gp120 co-receptor site in the absence of CD4 and illustrate that conformational stabilization, imparted by primary receptor interaction, can alter the immunogenicity of a type 1 viral membrane protein.

B cell recognition of the conserved HIV-1 co-receptor binding site is altered by endogenous primate CD4.

Science.gov (United States)

Forsell, Mattias N E; Dey, Barna; Mörner, Andreas; Svehla, Krisha; O'dell, Sijy; Högerkorp, Carl-Magnus; Voss, Gerald; Thorstensson, Rigmor; Shaw, George M; Mascola, John R; Karlsson Hedestam, Gunilla B; Wyatt, Richard T

2008-10-03

The surface HIV-1 exterior envelope glycoprotein, gp120, binds to CD4 on the target cell surface to induce the co-receptor binding site on gp120 as the initial step in the entry process. The binding site is comprised of a highly conserved region on the gp120 core, as well as elements of the third variable region (V3). Antibodies against the co-receptor binding site are abundantly elicited during natural infection of humans, but the mechanism of elicitation has remained undefined. In this study, we investigate the requirements for elicitation of co-receptor binding site antibodies by inoculating rabbits, monkeys and human-CD4 transgenic (huCD4) rabbits with envelope glycoprotein (Env) trimers possessing high affinity for primate CD4. A cross-species comparison of the antibody responses showed that similar HIV-1 neutralization breadth was elicited by Env trimers in monkeys relative to wild-type (WT) rabbits. In contrast, antibodies against the co-receptor site on gp120 were elicited only in monkeys and huCD4 rabbits, but not in the WT rabbits. This was supported by the detection of high-titer co-receptor antibodies in all sera from a set derived from human volunteers inoculated with recombinant gp120. These findings strongly suggest that complexes between Env and (high-affinity) primate CD4 formed in vivo are responsible for the elicitation of the co-receptor-site-directed antibodies. They also imply that the naïve B cell receptor repertoire does not recognize the gp120 co-receptor site in the absence of CD4 and illustrate that conformational stabilization, imparted by primary receptor interaction, can alter the immunogenicity of a type 1 viral membrane protein.

Role of the adsorbed oxygen species in the selective electrochemical reduction of CO_2 to alcohols and carbonyls on copper electrodes

International Nuclear Information System (INIS)

Le Duff, Cecile S.; Lawrence, Matthew J.; Rodriguez, Paramaconi

2017-01-01

The electrochemical reduction of CO_2 into fuels has gained significant attention recently as source of renewable carbon-based fuels. The unique high selectivity of copper in the electrochemical reduction of CO_2 to hydrocarbons has called much interest in discovering its mechanism. In order to provide significant information about the role of oxygen in the electrochemical reduction of CO_2 on Cu electrodes, the conditions of the surface structure and the composition of the Cu single crystal electrodes were controlled over time. This was achieved using pulsed voltammetry, since the pulse sequence can be programmed to guarantee reproducible initial conditions for the reaction at every fraction of time and at a given frequency. In contrast to the selectivity of CO_2 reduction using cyclic voltammetry and chronoamperometric methods, a large selection of oxygenated hydrocarbons was found under alternating voltage conditions. Product selectivity towards the formation of oxygenated hydrocarbon was associated to the coverage of oxygen species, which is surface-structure- and potential-dependent. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Supra-optimal expression of the cold-regulated OsMyb4 transcription factor in transgenic rice changes the complexity of transcriptional network with major effects on stress tolerance and panicle development

KAUST Repository

Park, Myoungryoul; Yun, Kilyoung; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Wijaya, Edward; Bajic, Vladimir B.; Yun, Songjoong; De Los Reyes, Benildo G.

2010-01-01

acid (JA), salicylic acid (SA), ethylene and reactive oxygen species (ROS) responsive genes. OsMyb4 network is independent of drought response element binding protein/C-repeat binding factor (DREB/CBF) and its sub-regulons operate with possible co

Co-operation and Competition in Regional Economic Development Associated with Radioactive Waste Management

International Nuclear Information System (INIS)

Webler, Thomas

2009-01-01

Competition and co-operation appear in many different social venues. The author gives a variety of examples of co-operative behaviour in economics, politics, research, and everyday life activities such as sports. These four diverse examples illustrate the variety of forms that co-operation may take such as tacit co-operation, incremental co-operation, deep co-operation, etc. The links with the form of democracy (adversary democracy or consensual democracy) are also pointed. However, as with so many other things in life, the key is to the question of co-operation or competition is balance. Co-operation and competition are dialectical opposites. They create and maintain and define each other; they each are incomplete without the other

Family co-operation programme description.

Science.gov (United States)

Peine, H A; Terry, T

1990-01-01

Current parenting practices indicate a continuing trend towards less family interaction. Institutional attempts to intervene with parents often fail. The 'Family Co-operation Programme' provides a tangible method for families and schools to work together in preventing alcohol and drug abuse, by utilising the positive influence of the home and strengthening family relationships. The Board of Education for the State of Utah has tested and is currently implementing a unique, low-cost, alternative to impact on the home. Utilising a K-12 alcohol/drug abuse school-based curriculum, the child, based on his/her inclass training, becomes the resource for family co-operation activities. These include training in coping skills, decision-making, resistance to peer persuasion, increased self-esteem and alcohol/drug information. Grade level materials go home with the child, who returns a requested parent evaluation. Data for over one thousand families show the positive impact of the activities.

Supercritical CO2 Extraction of Lavandula angustifolia Mill. Flowers: Optimisation of Oxygenated Monoterpenes, Coumarin and Herniarin Content.

Science.gov (United States)

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.

Suppressed Sr segregation and performance of directly assembled La0.6Sr0.4Co0.2Fe0.8O3-δ oxygen electrode on Y2O3-ZrO2 electrolyte of solid oxide electrolysis cells

Science.gov (United States)

Ai, Na; He, Shuai; Li, Na; Zhang, Qi; Rickard, William D. A.; Chen, Kongfa; Zhang, Teng; Jiang, San Ping

2018-04-01

Active and stable oxygen electrode is probably the most important in the development of solid oxide electrolysis cells (SOECs) technologies. Herein, we report the successful development of mixed ionic and electronic conducting (MIEC) La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) perovskite oxides directly assembled on barrier-layer-free yttria-stabilized zirconia (YSZ) electrolyte as highly active and stable oxygen electrodes of SOECs. Electrolysis polarization effectively induces the formation of electrode/electrolyte interface, similar to that observed under solid oxide fuel cell (SOFC) operation conditions. However, in contrast to the significant performance decay under SOFC operation conditions, the cell with directly assembled LSCF oxygen electrodes shows excellent stability, tested for 300 h at 0.5 A cm-2 and 750 °C under SOEC operation conditions. Detailed microstructure and phase analysis reveal that Sr segregation is inevitable for LSCF electrode, but anodic polarization substantially suppresses Sr segregation and migration to the electrode/electrolyte interface, leading to the formation of stable and efficient electrode/electrolyte interface for water and CO2 electrolysis under SOECs operation conditions. The present study demonstrates the feasibility of using directly assembled MIEC cobaltite based oxygen electrodes on barrier-layer-free YSZ electrolyte of SOECs.

Co@Co3 O4 @PPD Core@bishell Nanoparticle-Based Composite as an Efficient Electrocatalyst for Oxygen Reduction Reaction.

Science.gov (United States)

Wang, Zhijuan; Li, Bing; Ge, Xiaoming; Goh, F W Thomas; Zhang, Xiao; Du, Guojun; Wuu, Delvin; Liu, Zhaolin; Andy Hor, T S; Zhang, Hua; Zong, Yun

2016-05-01

Durable electrocatalysts with high catalytic activity toward oxygen reduction reaction (ORR) are crucial to high-performance primary zinc-air batteries (ZnABs) and direct methanol fuel cells (DMFCs). An efficient composite electrocatalyst, Co@Co3 O4 core@shell nanoparticles (NPs) embedded in pyrolyzed polydopamine (PPD) is reported, i.e., in Co@Co3 O4 @PPD core@bishell structure, obtained via a three-step sequential process involving hydrothermal synthesis, high temperature calcination under nitrogen atmosphere, and gentle heating in air. With Co@Co3 O4 NPs encapsulated by ultrathin highly graphitized N-doped carbon, the catalyst exhibits excellent stability in aqueous alkaline solution over extended period and good tolerance to methanol crossover effect. The integration of N-doped graphitic carbon outer shell and ultrathin nanocrystalline Co3 O4 inner shell enable high ORR activity of the core@bishell NPs, as evidenced by ZnABs using catalyst of Co@Co3 O4 @PPD in air-cathode which delivers a stable voltage profile over 40 h at a discharge current density of as high as 20 mA cm(-2) . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Self-reliance through regional co-operation

International Nuclear Information System (INIS)

Glubrecht, H.

1975-01-01

Article 52 of the Charter of the United Nations is concerned with the usefulness of Regional Arrangements which 'are appropriate for regional action'. Such arrangements need not be considered only with regard to their political aspects but also as organizational structures which can be helpful in the development of science and technology in less developed countries. The definition of a 'Region' can be difficult, but is easier if scientific rather than political co-operation is intended. The International Atomic Energy Agency has undertaken a first step in this direction through its Regional Co-operative Agreement for Research, Development and Training related to Nuclear Science and Technology in South and Southeast Asia, the Pacific and the Far East (RCA) which has been signed by six countries so far. This Agreement leaves it to the Member States to initiate cooperative projects. The IAEA will take steps to establish the project if at least three Member States are willing to participate. The implementation of the project will be defined by negotiations with the Member States and the IAEA will only play the role of a co-ordinator. Annual meetings of representatives of those countries which are parties of the RCA and of others from the region which might be interested in joining the Agreement provide the possibility of a continuing exchange of new ideas. Regional activities are also undertaken by means of 'Co-ordinated Research Programmes', which mostly include some co-operation with LDCs. The RCA has initiated two new ideas, that of carrying out the projects exclusively by the countries of the region and that of taking the step from co-ordination to cooperation by means of continuous and intensive exchange of information as well as of personnel. Its main objective is to aim at a reasonable division of labour between the parties and to use expensive equipment jointly. It is to be hoped that this venture will lead to an increasing degree of self-reliance within the

Structure-based stabilization of HIV-1 gp120 enhances humoral immune responses to the induced co-receptor binding site.

Directory of Open Access Journals (Sweden)

Barna Dey

2009-05-01

Full Text Available The human immunodeficiency virus type 1 (HIV-1 exterior envelope glycoprotein, gp120, possesses conserved binding sites for interaction with the primary virus receptor, CD4, and also for the co-receptor, generally CCR5. Although gp120 is a major target for virus-specific neutralizing antibodies, the gp120 variable elements and its malleable nature contribute to evasion of effective host-neutralizing antibodies. To understand the conformational character and immunogenicity of the gp120 receptor binding sites as potential vaccine targets, we introduced structure-based modifications to stabilize gp120 core proteins (deleted of the gp120 major variable regions into the conformation recognized by both receptors. Thermodynamic analysis of the re-engineered core with selected ligands revealed significant stabilization of the receptor-binding regions. Stabilization of the co-receptor-binding region was associated with a marked increase in on-rate of ligand binding to this site as determined by surface plasmon resonance. Rabbit immunization studies showed that the conformational stabilization of core proteins, along with increased ligand affinity, was associated with strikingly enhanced humoral immune responses against the co-receptor-binding site. These results demonstrate that structure-based approaches can be exploited to stabilize a conformational site in a large functional protein to enhance immunogenic responses specific for that region.

International co-operation on decommissioning - Achievements of the NEA Co-operative programme 1985-1990

International Nuclear Information System (INIS)

1992-01-01

Decommissioning of nuclear facilities is attracting a growing interest in all countries where an increasing number of plants are reaching the end of their operational life and will have to be decommissioned in the next few years. In response to this interest, the NEA set up in 1985 an international programme of technical co-operation between decommissioning projects in eight OECD countries. This report describes the programme and the participating projects, reviews the experiences accumulated during the first five-year term of this international undertaking, and discusses what remains to be done

Oxygen transport in La0.6Sr0.4Co1-yFeyO3-d

NARCIS (Netherlands)

Bouwmeester, Henricus J.M.; den Otter, M.W.; Boukamp, Bernard A.

2004-01-01

The surface exchange coefficient and chemical diffusion coefficient of oxygen for the perovskites La0.6Sr0.4Co1–yFeyO3–delta (y=0.2, 0.5 and 0.8) were measured using the conductivity relaxation technique. Measurements were performed between 600 and 800 °C in an oxygen partial pressure range between

Carbon-supported cubic CoSe2 catalysts for oxygen reduction reaction in alkaline medium

International Nuclear Information System (INIS)

Feng Yongjun; Alonso-Vante, Nicolas

2012-01-01

Highlights: ► Cubic CoSe 2 a non-precious metal electrocatalyst for oxygen reduction in KOH. ► The catalyst shows four-electron transfer pathway in overall reaction. ► Catalyst has higher methanol tolerance than commercial Pt/C catalyst. - Abstract: A Carbon-supported CoSe 2 nanocatalyst has been developed as an alternative non-precious metal electrocatalyst for oxygen reduction reaction (ORR) in alkaline medium. The catalyst was prepared via a surfactant-free route and its electrocatalytic activity for the ORR has been investigated in detail in 0.1 M KOH electrolyte at 25 °C using rotating disk electrode (RDE) and rotating ring-disk electrode (RRDE) techniques. The prepared catalyst showed promising catalytic activity towards ORR in a four-electron transfer pathway and higher tolerance to methanol compared to commercial Pt/C catalyst in 0.1 M KOH. To some extent, the increase of CoSe 2 loading on the electrode favors a faster reduction of H 2 O 2 intermediate to H 2 O.

Identification of catalytic sites in cobalt-nitrogen-carbon materials for the oxygen reduction reaction.

Science.gov (United States)

Zitolo, Andrea; Ranjbar-Sahraie, Nastaran; Mineva, Tzonka; Li, Jingkun; Jia, Qingying; Stamatin, Serban; Harrington, George F; Lyth, Stephen Mathew; Krtil, Petr; Mukerjee, Sanjeev; Fonda, Emiliano; Jaouen, Frédéric

2017-10-16

Single-atom catalysts with full utilization of metal centers can bridge the gap between molecular and solid-state catalysis. Metal-nitrogen-carbon materials prepared via pyrolysis are promising single-atom catalysts but often also comprise metallic particles. Here, we pyrolytically synthesize a Co-N-C material only comprising atomically dispersed cobalt ions and identify with X-ray absorption spectroscopy, magnetic susceptibility measurements and density functional theory the structure and electronic state of three porphyrinic moieties, CoN 4 C 12 , CoN 3 C 10,porp and CoN 2 C 5 . The O 2 electro-reduction and operando X-ray absorption response are measured in acidic medium on Co-N-C and compared to those of a Fe-N-C catalyst prepared similarly. We show that cobalt moieties are unmodified from 0.0 to 1.0 V versus a reversible hydrogen electrode, while Fe-based moieties experience structural and electronic-state changes. On the basis of density functional theory analysis and established relationships between redox potential and O 2 -adsorption strength, we conclude that cobalt-based moieties bind O 2 too weakly for efficient O 2 reduction.Nitrogen-doped carbon materials with atomically dispersed iron or cobalt are promising for catalytic use. Here, the authors show that cobalt moieties have a higher redox potential, bind oxygen more weakly and are less active toward oxygen reduction than their iron counterpart, despite similar coordination.

Effect of heterologous expression of acyl-CoA-binding protein on acyl-CoA level and composition in yeast

DEFF Research Database (Denmark)

Mandrup, S; Jepsen, R; Skøtt, H

1993-01-01

We have expressed a bovine synthetic acyl-CoA-binding protein (ACBP) gene in yeast (Saccharomyces cerevisiae) under the control of the GAL1 promoter. The heterologously expressed bovine ACBP constituted up to 6.4% of total cellular protein and the processing was identical with that of native bovi...

Proton conductive Pt-Co nanoparticles anchoring on citric acid functionalized graphene for efficient oxygen reduction reaction

Science.gov (United States)

Zhao, Yige; Liu, Jingjun; Wu, Yijun; Wang, Feng

2017-08-01

Designing highly efficient electro-catalysts for the oxygen reduction reaction (ORR) has been regarded as a demanding task in the development of renewable energy sources. However, little attention has been paid on improving Pt-based catalysts by promoting proton transfer from the electrolyte solutions to the catalyst layer at the cathode. Herein, we design proton conductive Pt-Co alloy nanoparticles anchoring on citric acid functionalized graphene (Pt-Co/CA-G) catalysts for efficient ORR. The facile modification approach for graphene can introduce oxygenated functional groups on the graphene surface to promote proton transfer as well as keeping the high electron conductivity without destroying the graphene original structure. The electrochemical results show that the Pt-Co/CA-G catalyst exhibits more excellent ORR activity and stability than the commercial Pt/C catalyst, which can be attributed to its improved proton transfer ability. The fast proton transfer comes from the hydrogen-bonding networks formed by the interaction between the oxygenated functional groups and water molecules. This work provides not only a novel and simple approach to modify graphene but also an effective strategy to improve Pt-based catalysts for the ORR.

CO2 on the International Space Station: An Operations Update

Science.gov (United States)

Law, Jennifer; Alexander, David

2016-01-01

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

Cerebral interstitial tissue oxygen tension, pH, HCO3, CO2.

Science.gov (United States)

Charbel, F T; Hoffman, W E; Misra, M; Hannigan, K; Ausman, J I

1997-10-01

There are many techniques for monitoring the injured brain following trauma, subarachnoid hemorrhage, or surgery. It is thought that the major determinants for recovery of injured cerebral tissue are oxygen, glucose delivery, and the clearance of metabolites. These factors, at optimal levels, are probably responsible for the regaining of neuronal functions. These parameters are in turn dependent on the tissue's blood flow and metabolism. We have been using a single, compact, polyethylene sensor, the Paratrend 7 for the measurement of cerebral oxygen tension, CO2, pH, and temperature. This sensor is designed for continuous blood gas analysis to aid in monitoring neurosurgical patients, both during surgery and in the intensive care unit. Using the Paratrend 7 sensor, we found the normal range of values to be: PO2 33 +/- 11 mm Hg; PCO2 48 +/- 7 mm Hg; pH 7.19 +/- 0.11. Critical measurements are considered to be tissue PO2 60 mm Hg, and pH effective method of measuring tissue cerebral oxygen tension, along with carbon dioxide levels, pH, and temperature.

Relating surface chemistry and oxygen surface exchange in LnBaCo2O(5+δ) air electrodes.

Science.gov (United States)

Téllez, Helena; Druce, John; Kilner, John A; Ishihara, Tatsumi

2015-01-01

The surface and near-surface chemical composition of electroceramic materials often shows significant deviations from that of the bulk. In particular, layered materials, such as cation-ordered LnBaCo2O(5+δ) perovskites (Ln = lanthanide), undergo surface and sub-surface restructuring due to the segregation of the divalent alkaline-earth cation. These processes can take place during synthesis and processing steps (e.g. deposition, sintering or annealing), as well as at temperatures relevant for the operation of these materials as air electrodes in solid oxide fuel cells and electrolysers. Furthermore, the surface segregation in these double perovskites shows fast kinetics, starting at temperatures as low as 400 °C over short periods of time and leading to a decrease in the transition metal surface coverage exposed to the gas phase. In this work, we use a combination of stable isotope tracer labeling and surface-sensitive ion beam techniques to study the oxygen transport properties and their relationship with the surface chemistry in ordered LnBaCo2O(5+δ) perovskites. Time-of-Flight Secondary-Ion Mass Spectrometry (ToF-SIMS) combined with (18)O isotope exchange was used to determine the oxygen tracer diffusion (D*) and surface exchange (k*) coefficients. Furthermore, Low Energy Ion Scattering (LEIS) was used for the analysis of the surface and near surface chemistry as it provides information from the first mono-atomic layer of the materials. In this way, we could relate the compositional modifications (e.g. cation segregation) taking place at the electrochemically-active surface during the exchange at high temperatures and the oxygen transport properties in double perovskite electrode materials to further our understanding of the mechanism of the surface exchange process.

Three-state combinatorial switch models as applied to the binding of oxygen by human hemoglobin.

Science.gov (United States)

Straume, M; Johnson, M L

1988-02-23

We have generated a series of all 6561 unique, discrete three-state combinatorial switch models to describe the partitioning of the cooperative oxygen-binding free change among the 10 variously ligated forms of human hemoglobin tetramers. These models were inspired by the experimental observation of Smith and Ackers that the cooperative free energy of the intersubunit contact regions of the 10 possible ligated forms of human hemoglobin tetramers can be represented by a particular distribution of three distinct energy levels [Smith, F. R., & Ackers, G. K. (1985) Proc. Natl. Acad. Sci. U.S.A. 82, 5347-5351]. A statistical thermodynamic formulation accounting for both dimer-tetramer equilibria and ligand binding properties of hemoglobin solutions as a function of oxygen and protein concentrations was utilized to exhaustively test these thermodynamic models. In this series of models each of the 10 ligated forms of the hemoglobin tetramer can exist in one, and only one, of three possible energy levels; i.e., each ligated form was assumed to be associated with a discrete energy state. This series of models includes all possible ways that the 10 ligation states of hemoglobin can be distributed into three distinct cooperative energy levels. The mathematical models, as presented here, do not permit equilibria between energy states to exist for any of the 10 unique ligated forms of hemoglobin tetramers. These models were analyzed by nonlinear least-squares estimation of the free energy parameters characteristic of this statistical thermodynamic development.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of operating parameters of a burner of oxygen conversion on flame characteristics

Energy Technology Data Exchange (ETDEWEB)

Glike, A P

1980-01-01

Combustion of high-calorie gases under pressure makes it possible to create compact fuel-burning devices. As applied to open-hearth furnaces, several types of these devices have been developed. The oxidizer used is oxygen, blowing, enriched with oxygen or compressed air. Reformation of natural gas in the chamber of the burner of oxygen conversion operating under pressure up to 2 kg-f/cm/sup 2/ makes it possible to obtain a high-temperature flame with satisfactory illumination without using mazut.

International co-operation in the supply of nuclear fuel cycle services

International Nuclear Information System (INIS)

Allday, C.

1977-01-01

The paper draws on B.N.F.L.'s wide experience of international collaboration in nuclear fuel process activities to examine the pros and cons of international agreements. Initially, the factors that influence the need to co-operate, the extent of possible co-operation and the alternative types of agreement are reviewed. Next, the benefits, problems and risks associated with each function, such as managmenet, financial, R and D, marketing and operations that could be covered within the scope of an international agreement, are examined in detail. The paper continues by calling upon specific experience obtained by B.N.F.L. in co-operation with other organisations over several years in operating both major and much smaller agreements illustrating the rationale behind the co-operation, the resolution of 'teething' troubles and the current status of these organisations. In conclusion, the paper comments upon the effectiveness of collaboration agreements and identifies several requirements for internation co-operation to succeed

CoPd x oxygen reduction electrocatalysts for polymer electrolyte membrane and direct methanol fuel cells

International Nuclear Information System (INIS)

Mustain, William E.; Kepler, Keith; Prakash, Jai

2007-01-01

The electrochemical activity of carbon-supported cobalt-palladium alloy electrocatalysts of various compositions have been investigated for the oxygen reduction reaction in a 5 cm 2 single cell polymer electrolyte membrane fuel cell. The polarization experiments have been conducted at various temperatures between 30 and 60 deg. C and the reduction performance compared with data from a commercial Pt catalyst under identical conditions. Investigation of the catalytic activity of the CoPd x PEMFC system with varying composition reveals that a nominal cobalt-palladium atomic ratio of 1:3, CoPd 3 , exhibits the best performance of all studied catalysts, exhibiting a catalytic activity comparable to the commercial Pt catalyst. The ORR on CoPd 3 has a low activation energy, 52 kJ/mol, and a Tafel slope of approximately 60 mV/decade, indicating that the rate-determining step is a chemical step following the first electron transfer step and may involve the breaking of the oxygen bond. The CoPd 3 catalyst also exhibits excellent chemical stability, with the open circuit cell voltage decreasing by only 3% and the observed current decreasing by only 10% at 0.8 V over 25 h. The CoPd 3 catalyst also exhibits superior tolerance to methanol crossover poisoning than Pt

Imprint and oxygen deficiency in (Pb,La)(Zr,Ti)O3 thin-film capacitors with La-Sr-Co-O electrodes

International Nuclear Information System (INIS)

Lee, J.; Ramesh, R.; Keramidas, V.G.; Warren, W.L.; Pike, G.E.; Evans, J.T. Jr.

1995-01-01

La-Sr-Co-O/Pb-La-Zr-Ti-O/La-Sr-Co-O thin-film capacitors have been grown in various oxygen ambients by pulsed laser deposition. As the oxygen ambient became more reducing, the capacitors developed more voltage asymmetry in hysteresis loops and a more preferred polarization state directed towards the top electrode. PLZT capacitors cooled in a fully oxidizing atmosphere (i.e., 1 atm oxygen pressure) exhibited nominally symmetric hysteresis loops and also showed little imprint both with and without fully saturating bias fields. We find that ambient oxygen pressure is an important process parameter and the imprint behavior is closely related with ambient oxygen induced effects such as oxygen vacancies, its related defect-dipole complexes and trapping of free charges. The different imprint behavior under negative and positive bias also suggests that the dipolar-defect complexes tend to cause imprint in PLZT capacitors

HIGH PERFORMANCE CERIA BASED OXYGEN MEMBRANE

DEFF Research Database (Denmark)

2014-01-01

The invention describes a new class of highly stable mixed conducting materials based on acceptor doped cerium oxide (CeO2-8 ) in which the limiting electronic conductivity is significantly enhanced by co-doping with a second element or co- dopant, such as Nb, W and Zn, so that cerium and the co......-dopant have an ionic size ratio between 0.5 and 1. These materials can thereby improve the performance and extend the range of operating conditions of oxygen permeation membranes (OPM) for different high temperature membrane reactor applications. The invention also relates to the manufacturing of supported...

Role of the adsorbed oxygen species in the selective electrochemical reduction of CO{sub 2} to alcohols and carbonyls on copper electrodes

Energy Technology Data Exchange (ETDEWEB)

Le Duff, Cecile S.; Lawrence, Matthew J.; Rodriguez, Paramaconi [School of Chemistry, University of Birmingham, Edgbaston (United Kingdom)

2017-10-09

The electrochemical reduction of CO{sub 2} into fuels has gained significant attention recently as source of renewable carbon-based fuels. The unique high selectivity of copper in the electrochemical reduction of CO{sub 2} to hydrocarbons has called much interest in discovering its mechanism. In order to provide significant information about the role of oxygen in the electrochemical reduction of CO{sub 2} on Cu electrodes, the conditions of the surface structure and the composition of the Cu single crystal electrodes were controlled over time. This was achieved using pulsed voltammetry, since the pulse sequence can be programmed to guarantee reproducible initial conditions for the reaction at every fraction of time and at a given frequency. In contrast to the selectivity of CO{sub 2} reduction using cyclic voltammetry and chronoamperometric methods, a large selection of oxygenated hydrocarbons was found under alternating voltage conditions. Product selectivity towards the formation of oxygenated hydrocarbon was associated to the coverage of oxygen species, which is surface-structure- and potential-dependent. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

A truncated receptor-binding domain of MERS-CoV spike protein potently inhibits MERS-CoV infection and induces strong neutralizing antibody responses: implication for developing therapeutics and vaccines.

Directory of Open Access Journals (Sweden)

Lanying Du

Full Text Available An emerging respiratory infectious disease with high mortality, Middle East respiratory syndrome (MERS, is caused by a novel coronavirus (MERS-CoV. It was first reported in 2012 in Saudi Arabia and has now spread to eight countries. Development of effective therapeutics and vaccines is crucial to save lives and halt the spread of MERS-CoV. Here, we show that a recombinant protein containing a 212-amino acid fragment (residues 377-588 in the truncated receptor-binding domain (RBD: residues 367-606 of MERS-CoV spike (S protein fused with human IgG Fc fragment (S377-588-Fc is highly expressed in the culture supernatant of transfected 293T cells. The purified S377-588-Fc protein efficiently binds to dipeptidyl peptidase 4 (DPP4, the receptor of MERS-CoV, and potently inhibited MERS-CoV infection, suggesting its potential to be further developed as a therapeutic modality for treating MERS-CoV infection and saving the patients' lives. The recombinant S377-588-Fc is able to induce in the vaccinated mice strong MERS-CoV S-specific antibodies, which blocks the binding of RBD to DPP4 receptor and effectively neutralizes MERS-CoV infection. These findings indicate that this truncated RBD protein shows promise for further development as an effective and safe vaccine for the prevention of MERS-CoV infection.

The Agency's technical co-operation activities in 1992

International Nuclear Information System (INIS)

1993-08-01

This report on the International Atomic Energy Agency's Technical Co-operation Activities in 1992 contains an overview of the general issues involved, including both in-house and external developments, resources and delivery, and evaluation of programs; an overview by field of activity and by division within the Agency; an overview by geographic area, distinguishing (i) Africa, (ii) Asia and the Pacific, (iii) Latin America, (iv) and the Middle East and Europe; an overview by component (i.e., experts, equipment, fellowships, training courses, sub-contracts and miscellaneous); and an overview by fund technical assistance and co-operation fund, extrabudgetary resources, United Nations Development Program (UNDP), assistance in kind. It also contains a profile on technical co-operation activities in Latin America. Projects concluded during 1992 are listed together with a description of their achievements. It concludes with implementation summaries. 10 figs, 9 tabs

Near Surface CO2 Triple Oxygen Isotope Composition

Directory of Open Access Journals (Sweden)

Sasadhar Mahata

2016-02-01

Full Text Available The isotopic composition of carbon dioxide in the atmosphere is a powerful tool for constraining its sources and sinks. In particular, the 17O oxygen anomaly [Δ17O = 1000 × ln(1 + δ17O/1000 - 0.516 × 1000 × ln(1 + δ18O/1000], with a value > 0.5‰ produced in the middle atmosphere, provides an ideal tool for probing the exchange of carbon dioxide between the biosphere/hydrosphere and atmosphere. The biosphere/hydrosphere and anthropogenic emissions give values ≤ 0.3‰. Therefore, any anomaly in near surface CO2 would reflect the balance between stratospheric input and exchange with the aforementioned surface sources. We have analyzed Δ17O values of CO2 separated from air samples collected in Taipei, Taiwan, located in the western Pacific region. The obtained mean anomaly is 0.42 ± 0.14‰ (1-σ standard deviation, in good agreement with model prediction and a published decadal record. Apart from typically used δ13C and δ18O values, the Δ17O value could provide an additional tracer for constraining the carbon cycle.

Oxygen-Fired CO{sub 2} Recycle for Application to Direct CO{sub 2} Capture form Coal-Fired Power Plants

Energy Technology Data Exchange (ETDEWEB)

Thomas Gale

2010-09-26

The Southern Research/Southern Company 1 MWth Pilot-Scale Coal-Fired Test Facility was successfully retrofit to fire in either the traditional air-fired mode or with 100% oxygen and recycled flue gas, with a fully integrated feedback and control system, including oxygen and recycled flue gas modulation during startup, transfer, and shutdown, safety and operational interlocks, and data acquisition. A MAXON Staged Oxygen Burner for Oxy-Coal Applications produced a stable flame over a significant range of firing turn-down, staging, and while firing five different U.S. coal types. The MAXON burner design produces lower flame temperatures than for air firing, which will enable (A) Safe operation, (B) Reduction of recycle flow without concern about furnace flame temperatures, and (C) May likely be affective at reducing slagging and fouling in the boiler and super heater at full-scale Power Plants. A CFD model of the Oxy-fired Combustion Research Facility (OCRF) was used to predict the flame geometry and temperatures in the OCRF and make a comparison with the air-fired case. The model predictions were consistent with the experimental data in showing that the MAXON burner fired with oxygen produced lower flame temperatures than the air-fired burner while firing with air.

International co-operation in nuclear data evaluation

International Nuclear Information System (INIS)

Nordborg, C.

2003-01-01

The NEA Working Party on International Nuclear Data Evaluation Co-operation serves as a forum for the exchange of information on required improvements to evaluated nuclear data libraries used in all nuclear application areas. The main objective is to identify the major discrepancies in existing evaluated data libraries and to resolve these discrepancies in specifically established expert groups. The long-term goal is to have converging evaluated data libraries. This co-operative effort is very successful. It has resolved a number of outstanding nuclear data problems and has issued 15 reports in support of the studies undertaken jointly. (author)

Sustainability indicators - a tool for regional co-operation

OpenAIRE

Koitka, Heike

2002-01-01

Sustainability indicators are more than just numbers. Besides their main function of illustrating the complex vision of sustainability they could support some factors for success of regional co-operation through their development. Today the discussion on indicators and co-operation is mainly separated from each other. Sustainability indicators are developed on all spatial levels from neighbourhoods up to the United Nations. In some cases the indicators are developed but remain unused. Regiona...

Limitations of potentiometric oxygen sensors operating at low oxygen levels

DEFF Research Database (Denmark)

Lund, Anders; Jacobsen, Torben; Hansen, Karin Vels

2011-01-01

The electrochemical processes that limit the range of oxygen partial pressures in which potentiometric oxygen sensors can be used, were analysed using a theoretical and an experimental approach. Electrochemical impedance spectroscopy was performed on porous Pt/yttria stabilised zirconia (YSZ......) electrodes between 10−6 and 0.2 bar and at temperatures between 500 and 950 °C. The flow of oxide ions and electron holes through a sensor cell, with a YSZ electrolyte, were calculated under similar conditions. The oxygen permeation of the sensor cell was insignificant at an oxygen partial pressure of 10......−6 bar for an inlet flow rate higher than 2 L h−1 between 600 and 800 °C. The polarisation resistance measured between 10−6 and 10−4 bar was found to be inversely proportional to the oxygen partial pressure, nearly temperature independent and inversely proportional to the inlet gas flow rate, which shows...

O espaço da cooperativa "amigos do meio ambiente": cooperativa de trabalho ou cooperfraude? "Friends of the environment" co-operative: work co-operative or fraud co-operative?

Directory of Open Access Journals (Sweden)

Shirla Patrícia Weber Sterchile

2011-06-01

Full Text Available O presente artigo é resultado de pesquisa acadêmica que tem como objeto de estudo-pesquisa "A forma de existir e de ser da Cooperativa dos Agentes Ambientais de Santa Helena 'Amigos do Meio Ambiente' e sua imbricação na Usina de Beneficiamento de Resíduos Sólidos do município de Santa Helena-PR". Verificando o cotidiano profissional, o descontentamento de trabalhadores catadores de matérias recicláveis, o incentivo do gestor municipal para a instalação da usina e a formação da cooperativa, aliado aos postulados do capitalismo, em sua fase tardia, propusemos desconstruir e reconstruir o movimento do objeto em questão a partir da pesquisa teórica e empírica. Para coletar os dados utilizando a técnica de gravação, recorremos à análise documental e à observação. Após esse processo descrevemos e analisamos os conteúdos presentes. Concluímos em nosso estudo-pesquisa, que a Cooperativa - "Amigos do Meio Ambiente", é uma "cooperfraude", legitimada pelo Estado, que suprime os princípios do cooperativismo e exime o capital da raiz da exploração da força de trabalhoThis article resulted from a research aiming at "The form of existence and being of the Co-operative of Environmental Agents from St. Helena - 'Friends of the Environment' - and its imbrication in the Processing Plant of Solid Waste in the city of Santa Helena-PR". Checking the professional practice, the dissatisfaction of workers who collect recycling materials and the City Hall's encouragement to install the plant and to form the Co-operative, together with the tenets of capitalism in its late stage, we proposed to deconstruct and reconstruct the motion of the object studied from the empirical research. After analyzing our data we concluded that the "Friends of the Environment" Co-operative is a "fraud co-operative" legitimized by the State, that suppressed the principles of co-operativism and exempted the capital from the root of exploitation of the workforce

Carbon-Encapsulated Co3O4@CoO@Co Nanocomposites for Multifunctional Applications in Enhanced Long-life Lithium Storage, Supercapacitor and Oxygen Evolution Reaction

International Nuclear Information System (INIS)

Xu, Dongyang; Mu, Congpu; Xiang, Jianyong; Wen, Fusheng; Su, Can; Hao, Chunxue; Hu, Wentao; Tang, Yongfu; Liu, Zhongyuan

2016-01-01

Porous nanostructure composites materials had attracted widely attention due to their potential application in energy storage (Lithium ion batteries (LIBs) and supercapacitor) and electrocatalyst of oxygen evolution reaction (OER). Co 3 O 4 @CoO@Co@C nanocomposites had been successfully synthesized using glucose as carbon source and cobalt nitrate as metalprecurs or of Co 3 O 4 @CoO@Co@C, which has excellent electrochemical performance for LIBs, supercapacitor and OER. Three kinds of morphology samples marked by Co 3 O 4 @CoO@Co@C-2/1, Co 3 O 4 @CoO@Co@C-1/1 and Co 3 O 4 @CoO@Co@C-1/2 are synthesized due to different atomic ratio of cobalt/carbon in precursors. Electrochemical and catalytic performance of Co 3 O 4 @CoO@Co@C-2/1 nanocomposites is more excellent than Co 3 O 4 @CoO@Co@C-1/1 and Co 3 O 4 @CoO@Co@C-1/2. Co 3 O 4 @CoO@Co@C-2/1 shows that discharge capacity can maintain 450 mA h g −1 and coulombic efficiency is nearly 100% during 500 cycles for LIBs. It indicates the excellent cycling stability of Co 3 O 4 @CoO@Co@C-2/1 as electrode for supercapacitor that about 78.3% of initial specific capacitance can be retained after 10000 cycles at current density of 2 A g −1 . Co 3 O 4 @CoO@Co@C-2/1 as catalyst of OER shows excellent electrochemical durability over 15 hours continuous experiment.

Enhancement of stability for lithium oxygen batteries by employing electrolytes gelled by poly(vinylidene fluoride-co-hexafluoropropylene) and tetraethylene glycol dimethyl ether

International Nuclear Information System (INIS)

Zhang, Jinqiang; Sun, Bing; Xie, Xiuqiang; Kretschmer, Katja; Wang, Guoxiu

2015-01-01

Free-standing gel polymer electrolytes with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix plasticized with tetraethylene glycol dimethyl ether (TEGDME) were prepared and investigated. The as-prepared gel polymer electrolytes exhibited large operating window and acceptable ionic conductivity. When applied in lithium oxygen batteries, the gel polymer electrolyte could support a high initial discharge capacity of 2988 mAh g −1 when a carbon black electrode without catalyst was used as cathode. Furthermore, the battery with gel polymer electrolyte can last at least 50 cycles in the fixed capacity cycling, displaying an excellent stability. Detailed study reveals that the gelling process is essential for the cycling stability enhancement. With excellent electrochemical properties, the free-standing gel polymer electrolyte presented in this investigation has great application potentials in long-life lithium oxygen batteries.

Agricultural Productivity, Co-Operatives and Organisational ...

African Journals Online (AJOL)

Huria: Journal of the Open University of Tanzania ... can enhance productivity and increase farmers' income by bringing financial services closer. ... of Kimuli Agricultural Marketing Co-operative Society (AMCOS) and Muungano Savings and ...

In Operando Self-Healing of Perovskite Electrocatalysts: A Case Study of SrCoO3 for the Oxygen Evolution Reaction

KAUST Repository

Tahini, Hassan A.; Tan, Xin; Schwingenschlö gl, Udo; Smith, Sean C.

2017-01-01

Perovskites are promising catalysts for oxygen evolution reactions (OER); among them, SrCoO3 is one of the best for these reactions. We study the O* intermediates and the role of surface oxygen vacancies of SrCoO3 during OER. A self-healing mechanism is proposed in which O* are incorporated into the surface to recover the redox capabilities of the material.

In Operando Self-Healing of Perovskite Electrocatalysts: A Case Study of SrCoO3 for the Oxygen Evolution Reaction

KAUST Repository

Tahini, Hassan A.

2017-01-24

Perovskites are promising catalysts for oxygen evolution reactions (OER); among them, SrCoO3 is one of the best for these reactions. We study the O* intermediates and the role of surface oxygen vacancies of SrCoO3 during OER. A self-healing mechanism is proposed in which O* are incorporated into the surface to recover the redox capabilities of the material.

Natural gas co-operation in the Baltic region

International Nuclear Information System (INIS)

Jensen, J.K.

1996-01-01

Co-operation between the gas companies in the Baltic Region has been in place for several years. The overview given in this paper shows that the co-operation has been developed in trade, investments, privatisation and participation in the restructuring process. Finally, through a broad technical co-operation, significant efforts are made to establish common operational practices, codes and standards and the integrity of gas transmission pipelines. The Baltic Region, from a resource and gas interconnection point of view, enjoys a strategic position in the future development of the gas industry in Europe. The Baltic gas sector represents an interesting and growing gas market with the significant gas storage capacity. The region is also located strategically for planned gas interconnections and could serve as a transit corridor for the future gas supplies from western Siberia or the North Sea. This co-operation in the region is being supported by international regulations and agreements such as the Energy Charter between the European Union and the central and east European countries. However, at present the gas industry in the Baltic Region seems to be ahead of these international agreements. It may well be seen that trade arrangements such as Third Party Access are implemented directly by market forces rather than through international agreements. The regional development may thus be a driving force for the implementation of the Internal Energy Market for the gas industry

Homogeneously Dispersed Co9S8 Anchored on Nitrogen and Sulfur Co-Doped Carbon Derived from Soybean as Bifunctional Oxygen Electrocatalysts and Supercapacitors.

Science.gov (United States)

Xiao, Zhen; Xiao, Guozheng; Shi, Minhao; Zhu, Ying

2018-05-16

Developing low-cost and highly active multifunctional electrocatalysts to replace noble metal catalysts is crucial for the commercialization of future clean energy technology. Herein, homogeneous Co 9 S 8 nanoparticles anchored on nitrogen and sulfur co-doped porous carbon nanomaterials (CoS@NSCs) are fabricated by pyrolysis of natural soybean treated with cobalt nitrate. The unique porous structures of the soybean are utilized to provide space for the oxidation and complexation reactions for cobalt compounds, thus leading to in situ generation of homogenously dispersed cobalt sulfide nanoparticles that anchored on the N,S co-doped carbon framework. Because of the coupling effect of cobalt sulfide and doping heteroatoms, CoS@NSC-800 not only displays excellent electrocatalytic performances with low overpotential and high current density toward both oxygen reduction reaction and oxygen evolution reaction comparable to the commercial Pt/C catalyst and IrO 2 catalyst, but also might be a promising candidate for high-performance supercapacitors. The method for the preparation of the multifunctional hybrids is simple but effective for the formation of uniformly distributed metal sulfide nanoparticles anchored on carbon materials, therefore providing a new perspective for the design and synthesis of multifunctional electrocatalysts for electrochemical energy conversion and storage at a large scale.

International co-operation in the supply of nuclear fuel cycle services

International Nuclear Information System (INIS)

Allday, C.

1977-01-01

The paper draws on British Nuclear Fuels' (BNFL) wide experience of international collaboration in nuclear fuel process activities to examine the pros and cons of international agreements. Initially, the factors that influence the need to co-operate, the extent of possible co-operation and the alternative types of agreement, are reviewed. Next, the benefits, problems and risks associated with each function, such as management, financial R and D, marketing and operations that could be covered within the scope of an international agreement, are examined in detail. The paper continues by calling upon specific experience obtained by BNFL in the co-operation with other organizations over several years in both major and much smaller agreements, illustrating the rationale behind the co-operation, the resolution of 'teething' troubles and the present status of these organizations. In conclusion, the paper comments upon the effectiveness of collaboration agreements and identifies several requirements for international co-operation to succeed. (author)

Cross-continental triple oxygen isotope analysis of tropospheric CO2

Science.gov (United States)

Liang, M. C.; Rangarajan, R.; Newman, S.; Laskar, A. H.

2016-12-01

The abundance variations of near surface atmospheric CO2 isotopologues (primarily 16O12C16O, 16O13C16O, 17O12C16O, and 18O12C16O) represent an integrated signal from anthropogenic/biogeochemical processes, including fossil fuel burning, biospheric photosynthesis and respiration, hydrospheric isotope exchange with water, and stratospheric photochemistry. Oxygen isotopes, in particular, are affected by the carbon and water cycles. Being a useful tracer that directly probes governing processes in CO2 biogeochemical cycles, D17O (= ln(1+d17O) - 0.516´ln(1+d18O)) provides an alternative constraint on the strengths of the associated cycles involving CO2. Here, we report more than one year of data obtained from Taiwan (Taipei), South China Sea, and USA (Pasadena, CA and Palos Verdes, CA). On average, the D17O values from these locations are similar and show no significant influence from the 2014-2016 El Nino event, in contrast to what has been reported for the 1997-1998 El Nino from the CO2 data collected from La Jolla, CA. Implications for utilizing the new tracer D17O for carbon cycling studies will be made.

CoJet technology for oxygen injection injection in EAFS - industrial gases supply and customers productivity improvements; Tecnologia CoJet para injecao de oxigenio em FEAS - fornecimento de gases e aumento da produtividade dos clientes

Energy Technology Data Exchange (ETDEWEB)

Marques, Izaias Lucas; Zagury, Pedro Athias [White Martins Gases Industriais Ltda., Rio de Janeiro, RJ (Brazil)

2010-07-01

PRAXAIR is one of the largest industrial gases producers of the World, being present in more than 40 countries and strongly connected to the steel industry. PRAXAIR has experience to supply products and services to all kinds of steel mills. Several technologies developed by the Company, such as CoJet (a system to coherent oxygen jet injection in EAF and BOF furnaces), Slag Splashing (splashing slag to cover BOF furnaces walls increasing refractory wear campaign life), AOD (a process for specialty steel production) and others, are currently in commercial operation in different parts of the world. In Brazil, Praxair is the owner of White Martins, the largest industrial gases company in South America, present in nine countries of the continent. Company's portfolio includes atmospheric gases, carbonic gas production, acetylene, hydrogen, specialty and health and care gases, mixtures for welding, gas seamless steel cylinders, applications equipment, and storage and gases transportation. The Company also operates a natural gas liquefaction unit. In addition to technologies and process, Praxair / White Martins can also supply solutions for measurement, control and gases injection, according to strict safety and quality standards. The present work has the objective to show the benefits of the CoJet EAF System, oxygen injectors positioned in the furnace walls. In 2009, two systems have been installed in South American mills and the results achieved will be following discussed. (author)

Unraveling the facet-dependent and oxygen vacancy role for ethylene hydrogenation on Co{sub 3}O{sub 4} (110) surface: A DFT+U study

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yong-Chao; Pan, Lun; Lu, Jinhui; Song, Jiajia; Li, Zheng; Zhang, Xiangwen; Wang, Li [Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University (China); Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Zou, Ji-Jun, E-mail: jj_zou@tju.edu.cn [Key Laboratory for Green Chemical Technology of the Ministry of Education, School of Chemical Engineering and Technology, Tianjin University (China); Collaborative Innovative Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China)

2017-04-15

Highlights: • The mechanism of ethylene hydrogenation on perfect and oxygen defective Co{sub 3}O{sub 4}(110) is investigated by using DFT + U. • Oxygen vacancy promotes ethylene hydrogenation thermodynamically and kinetically. • The Co3O4 (110) facet is more active than the (111) one for ethylene hydrogenation. - Abstract: Crystal facet engineering and defect engineering are both critical strategies to improve the catalytic hydrogenation performance of catalyst. Herein, ethylene hydrogenation on the perfect and oxygen defective Co{sub 3}O{sub 4}(110) surfaces has been studied by using periodic density functional theory calculations. The results are compared with that on Co{sub 3}O{sub 4}(111) surface to clarify the problem of which facet for Co{sub 3}O{sub 4} is more reactive, and to illuminate the role of oxygen vacancy. The low oxygen vacancy formation energy suggests that Co{sub 3}O{sub 4}(110) surface with defective site is easily formed. The whole mechanism of H{sub 2} dissociation and stepwise hydrogenation of ethylene to ethane is examined, and the most favorable pathway is heterolytic dissociation of H{sub 2} follows two stepwise hydrogenation of ethylene process. The results show that ethyl hydrogenation to ethane on perfect Co{sub 3}O{sub 4}(110) surface is the rate limiting step with an activation energy of 1.19 eV, and the presence of oxygen vacancy strongly reduces the activation energies of main elementary steps, and the activation energy of rate limiting step is only 0.47 eV. Compared with that on Co{sub 3}O{sub 4}(111), ethylene hydrogenation is preferred on Co{sub 3}O{sub 4}(110) surface. Therefore, Co{sub 3}O{sub 4} with exposed (110) facet is predicted as an excellent catalyst for ethylene hydrogenation.

International co-operation through scientific and technical nuclear societies

International Nuclear Information System (INIS)

Manning Muntzing, L.

1983-01-01

As an international organization the American Nuclear Society (ANS) has played an active role in international co-operation of nuclear technology exchange since its establishment in 1954. The ANS has a membership of over 13,000 individuals, of whom approximately 1200 live overseas in forty countries. To carry out the goals of the Society, local sections have been established. Currently the ANS maintains 48 local sections in the United States of America and 8 overseas local sections in Africa, Asia, Europe and South America. The ANS also has formal agreements for co-operation with The Asociacion Argentina de Tecnologia Nuclear (AATN), the Israel Nuclear Society (INS), and the Chinese Nuclear Society (CNS). In 1977 the Japan Atomic Energy Society (JAES), the European Nuclear Society (ENS), and the ANS co-operation in sponsoring the First International Conference on Transfer of Nuclear Technology (ICONTT I) in Tehran, Iran. In 1982, the Second International Conference on Transfer of Nuclear Technology (ICONTT II), Buenos Aires, Argentina, was sponsored through the co-operation of the AATN, the ENS and the ANS. The ANS and its overseas sections sponsor the Pacific Basin Conference approximately every three years to discuss nuclear matters of concern to the countries around the Pacific Ocean. In 1981 the ANS held a Nuclear Technology Exhibit in Beijing, the People's Republic of China. In addition to meetings, the ANS is extensively involved in the co-operative exchange of applied nuclear research information through its publications. Nuclear Technology, a technical journal, is published monthly under joint ownership of the ENS and the ANS. The ANS has been a leader in voluntary standards development since 1958. In its dedication to the co-operation of international nuclear technology the ANS maintains a comprehensive international exchange of nuclear standards

Electrochemical Reduction of CO2 on IrxRu(1–x)O2(110) Surfaces 

DEFF Research Database (Denmark)

Bhowmik, Arghya; Hansen, Heine Anton; Vegge, Tejs

2017-01-01

with oxygen-coordinated intermediates that can circumvent the limitations imposed by the scaling relations on metal catalysts. Here, we introduce an innovative concept of ligand effects in oxide catalysts. Both IrO2 and RuO2 binds OH* and other intermediates from the electrochemical reduction of CO2 (CO2RR......High overpotentials and low faradic efficiencies plague metal catalysts for direct conversion of CO2 to methanol and other liquid fuels. RuO2-based electrocatalysts have been observed to evolve methanol at low overpotentials, which has been attributed to an alternative reaction mechanism......) strongly, but the stable and miscible system IrxRu(1-x)O2 exhibits anomalous weaker binding energy in the presence of CO* spectators, because of Ru–Ir ligand effects. The weakened adsorbate binding leads to a very low CO2RR onset potential (methanol evolution at −0.2 V RHE). An Ir atom at the bridge site...

Ordered oxygen deficient '112'perovskites, LnBaCo2 O5⋅ 50 ...

Indian Academy of Sciences (India)

... Refresher Courses · Symposia · Live Streaming. Home; Journals; Bulletin of Materials Science; Volume 32; Issue 3. Ordered oxygen deficient '112' perovskites, LnBaCo2O5.50+: complex magnetism and transport properties. B Raveau Md Motin Seikh V Pralong V Caignaert. Volume 32 Issue 3 June 2009 pp 305-312 ...

Reversible uptake of molecular oxygen by heteroligand Co(II)-L-α-amino acid-imidazole systems: equilibrium models at full mass balance.

Science.gov (United States)

Pająk, Marek; Woźniczka, Magdalena; Vogt, Andrzej; Kufelnicki, Aleksander

2017-09-19

The paper examines Co(II)-amino acid-imidazole systems (where amino acid = L-α-amino acid: alanine, asparagine, histidine) which, when in aqueous solutions, activate and reversibly take up dioxygen, while maintaining the structural scheme of the heme group (imidazole as axial ligand and O 2 uptake at the sixth, trans position) thus imitating natural respiratory pigments such as myoglobin and hemoglobin. The oxygenated reaction shows higher reversibility than for Co(II)-amac systems with analogous amino acids without imidazole. Unlike previous investigations of the heteroligand Co(II)-amino acid-imidazole systems, the present study accurately calculates all equilibrium forms present in solution and determines the [Formula: see text]equilibrium constants without using any simplified approximations. The equilibrium concentrations of Co(II), amino acid, imidazole and the formed complex species were calculated using constant data obtained for analogous systems under oxygen-free conditions. Pehametric and volumetric (oxygenation) studies allowed the stoichiometry of O 2 uptake reaction and coordination mode of the central ion in the forming oxygen adduct to be determined. The values of dioxygen uptake equilibrium constants [Formula: see text] were evaluated by applying the full mass balance equations. Investigations of oxygenation of the Co(II)-amino acid-imidazole systems indicated that dioxygen uptake proceeds along with a rise in pH to 9-10. The percentage of reversibility noted after acidification of the solution to the initial pH ranged within ca 30-60% for alanine, 40-70% for asparagine and 50-90% for histidine, with a rising tendency along with the increasing share of amino acid in the Co(II): amino acid: imidazole ratio. Calculations of the share of the free Co(II) ion as well as of the particular complex species existing in solution beside the oxygen adduct (regarding dioxygen bound both reversibly and irreversibly) indicated quite significant values for the

Acyl-CoA binding protein is an essential protein in mammalian cell lines

DEFF Research Database (Denmark)

Knudsen, Jens; Færgeman, Nils J.

2002-01-01

In the present work, small interference RNA was used to knock-down acyl-CoA binding protein (ACBP) in HeLa, HepG2 and Chang cells. Transfection with ACBP-specific siRNA stopped growth, detached cells from the growth surface and blocked thymidine and acetate incorporation. The results show...

CO₂ Binding Organic Liquids Gas Capture with Polarity Swing Assisted Regeneration

Energy Technology Data Exchange (ETDEWEB)

Heldebrant, David [Battelle Memorial Institute, Columbus, OH (United States)

2014-05-31

This report outlines the comprehensive bench-scale testing of the CO₂-binding organic liquids (CO₂BOLs) solvent platform and its unique Polarity Swing Assisted Regeneration (PSAR). This study outlines all efforts on a candidate CO₂BOL solvent molecule, including solvent synthesis, material characterization, preliminary toxicology studies, and measurement of all physical, thermodynamic and kinetic data, including bench-scale testing. Equilibrium and kinetic models and analysis were made using Aspen Plus™. Preliminary process configurations, a technoeconomic assessment and solvent performance projections for separating CO₂ from a subcritical coal-fired power plant are compared to the U.S. Department of Energy's Case 10 monoethanolamine baseline.

Novel Membranes and Processes for Oxygen Enrichment

Energy Technology Data Exchange (ETDEWEB)

Lin, Haiqing

2011-11-15

The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions

Integrated co-operative governance in the context of sustainable development

Directory of Open Access Journals (Sweden)

Eric Nealer

2011-07-01

Keywords:Sustainable development, governance, co-operative governance, integrated,organising, and communication. Disciplines:Public Administration, Public Management, Social Welfare, Environmental Management, Municipal public service delivery, Social Development, Organisational Behaviour, Co-operative Governance, Communication, Sustainable Development, Sustainable Organisational Development

Co-operation and Phase Behavior under the Mixed Updating Rules

International Nuclear Information System (INIS)

Zhang Wen; Li Yao-Sheng; Xu Chen

2015-01-01

We present a model by considering two updating rules when the agents play prisoner's dilemma on a square lattice. Agents can update their strategies by referencing one of his neighbors of higher payoffs under the imitation updating rule or directly replaced by one of his neighbors according to the death-birth updating rule. The frequency of co-operation is related to the probability q of occurrence of the imitation updating or the death-birth updating and the game parameter b. The death-birth updating rule favors the co-operation while the imitation updating rule favors the defection on the lattice, although both rules suppress the co-operation in the well-mixed population. Therefore a totally co-operative state may emerge when the death-birth updating is involved in the evolution when b is relatively small. We also obtain a phase diagram on the q-b plane. There are three phases on the plane with two pure phases of a totally co-operative state and a totally defective state and a mixing phase of mixed strategies. Based on the pair approximation, we theoretically analyze the phase behavior and obtain a quantitative agreement with the simulation results. (paper)

Influence of oxygen enrichment on compression ignition engines using biodiesel blends

Directory of Open Access Journals (Sweden)

Vaiyapuri Senthil Murugan

2017-01-01

Full Text Available The influence of oxygen enrichment on performance and emission characteristics of a single cylinder diesel engine operated with biodiesel blends have been investigated in this work. The methyl ester of jatropha biodiesel was selected as bio-diesel and four blends (B10, B20, B30, and B40 were selected for experimental investigations. The performance and emission characteristics were obtained for the these blends along with three oxygen enrichment flow rates (1, 3, and 5 L per minute using an oxygen cylinder at the air intake in the diesel engine. The performance and emission characteristics were studied and compared with the diesel and biodiesel. It was observed that, oxygen enrichment enhances the brake thermal efficiency, HC, CO, and smoke. B10 biodiesel with 5 L per minute oxygen enrichment was found to be the best fuel for biodiesel operation.

Topotactic Consolidation of Monocrystalline CoZn Hydroxides for Advanced Oxygen Evolution Electrodes.

Science.gov (United States)

Wang, Jing; Tan, Chuan Fu; Zhu, Ting; Ho, Ghim Wei

2016-08-22

We present a room temperature topotactic consolidation of cobalt and zinc constituents into monocrystalline CoZn hydroxide nanosheets, by a localized corrosion of zinc foils with cobalt precursors. By virtue of similar lattice orientation and structure coordination, the hybrid hydroxides amalgamate atomically without phase separation. Importantly, this in situ growth strategy, in combination with configurable percolated nanosheets, renders a high areal density of catalytic sites, immobilized structures, and conductive pathways between the nanosheets and underlying foils-all of which allow monocrystalline CoZn hydroxide nanosheet materials to function as effective electrodes for electrochemical oxygen evolution reactions. This convenient and eco-friendly topotactical transformation approach facilitates high-quality single crystal growth with improved multiphase purity and homogeneity, which can be extended to other transition metals for the fabrication of advanced functional nanocomposites. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CO-Tolerant Pt–BeO as a Novel Anode Electrocatalyst in Proton Exchange Membrane Fuel Cells

Directory of Open Access Journals (Sweden)

Kyungjung Kwon

2016-05-01

Full Text Available Commercialization of proton exchange membrane fuel cells (PEMFCs requires less expensive catalysts and higher operating voltage. Substantial anodic overvoltage with the usage of reformed hydrogen fuel can be minimized by using CO-tolerant anode catalysts. Carbon-supported Pt–BeO is manufactured so that Pt particles with an average diameter of 4 nm are distributed on a carbon support. XPS analysis shows that a peak value of the binding energy of Be matches that of BeO, and oxygen is bound with Be or carbon. The hydrogen oxidation current of the Pt–BeO catalyst is slightly higher than that of a Pt catalyst. CO stripping voltammetry shows that CO oxidation current peaks at ~0.85 V at Pt, whereas CO is oxidized around 0.75 V at Pt–BeO, which confirms that the desorption of CO is easier in the presence of BeO. Although the state-of-the-art PtRu anode catalyst is dominant as a CO-tolerant hydrogen oxidation catalyst, this study of Be-based CO-tolerant material can widen the choice of PEMFC anode catalyst.

Seasonal changes in blood oxygen transport and acid-base status in the tegu lizard, Tupinambis merianae.

Science.gov (United States)

Andrade, Denis V; Brito, Simone P; Toledo, Luís Felipe; Abe, Augusto S

2004-05-20

Oxygen-binding properties, blood gases, and acid-base parameters were studied in tegu lizards, Tupinambis merianae, at different seasons and temperatures. Independent of temperature and pH, blood oxygen affinity was higher in dormant lizards than in those active during the summer. Haematocrit (Hct) and hemoglobin content ([Hb]) were greater in active lizards resulting in a higher oxygen-carrying capacity. Nucleoside triphosphate content ([NTP]) was reduced during dormancy, but the ratio between [NTP] and [Hb] remained unchanged. Dormancy was accompanied by an increase in plasma bicarbonate ([HCO-(3)]pl) and an elevation of arterial CO2 partial pressure (PaCO2) and CO2 content in the plasma (CplCO2). These changes in acid-base parameters persist over a broad range of body temperatures. In vivo, arterial O2 partial pressure (PaO2) and O2 content (CaO2) were not affected by season and tended to increase with temperature. Arterial pH (pHa) of dormant animals is reduced compared to active lizards at body temperatures below 15 degrees C, while no significant difference was noticed at higher temperatures. Copyright 2003 Elsevier B.V.

Experience and co-operation in the development of nuclear engineering education

International Nuclear Information System (INIS)

Brochard, D.; Gladieux, A.

1998-01-01

This paper presents various aspects of the international co-operation set up at the Institut National des Sciences et Techniques Nucleaires (INSTN) for developing the nuclear engineering education in a European framework, with the Tempus programmes, or worldwide, through the IAEA technical co-operation programme. As such co-operation mainly relies on the courses established in the INSTN for national purposes, a short presentation of them is made first. (author)

Operational behaviour of CO{sub 2} booster systems; Betriebsverhalten von CO{sub 2}-Booster-Systemen

Energy Technology Data Exchange (ETDEWEB)

Javerschek, Oliver; Hieble, Tobias [BITZER Kuehlmaschinenbau GmbH, Sindelfingen (Germany)

2011-07-01

The operating characteristics of booster systems and the resulting operating conditions of CO{sub 2} booster systems in supermarket refrigeration are explained and discussed. Criteria and challenges of different operating and load conditions are gone into. Simulated and measured operating states of a small-scale booster system are compared and evaluated. [German] In der vorliegenden Veroeffentlichung werden unterschiedliche Betriebsverhalten und die daraus resultierenden Betriebsbedingungen von CO{sub 2}-Booster-Systemen in der Supermarktkaelte erlaeutert und diskutiert. Dabei werden wesentliche Kriterien und Herausforderungen bei den unterschiedlichen Betriebs- und Lastbedingungen besprochen. Ausserdem werden simulierte und gemessene Betriebszustaende einer kleinen Booster-Kaelteanlage vergleichend betrachtet und bewertet.

The performance of spinel bulk-like oxygen-deficient CoGa2O4 as an air-cathode catalyst in microbial fuel cell

Science.gov (United States)

Liu, Di; Mo, Xiaoping; Li, Kexun; Liu, Yi; Wang, Junjie; Yang, Tingting

2017-08-01

Nano spinel bulk-like CoGa2O4 prepared via a facile hydrothermal method is used as a high efficient electrochemical catalyst in activated carbon (AC) air-cathode microbial fuel cell (MFC). The maximum power density of the modified MFC is 1911 ± 49 mW m-2, 147% higher than the MFC of untreated AC cathode. Transmission electron microscope (TEM) and X-ray diffraction (XRD) exhibit the morphology and crystal structure of CoGa2O4. Rotating disk electrode (RDE) confirms the four-electron pathway at the cathode during the oxygen reduction reaction (ORR). Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) illustrate that the high rate oxygen vacancy exist in the CoGa2O4. The oxygen vacancy of CoGa2O4 plays an important role in catalytic activity. In a word, the prepared nano spinel bulk-like CoGa2O4 provides an alternative to the costly Pt in air-cathode for power output.

Isotopic exchange between CO2 and H2O and labelling kinetics of photosynthetic oxygen

International Nuclear Information System (INIS)

Gerster, Richard

1971-01-01

The reaction of carbon dioxide with water has been studied by measuring the rate of oxygen exchange between C 18 O 2 and H 2 16 O. The mathematical treatment of the kinetics allows to determine with accuracy the diffusion flow between the gas and the liquid phase, in the same way as the CO 2 hydration rate. The velocity constant of this last process, whose value gives the in situ enzymatic activity of carbonic anhydrase, has been established in the case of chloroplast and Euglena suspensions and of aerial leaves. The study of the isotopic exchange between C 18 O 2 and a vegetable submitted to alternations of dark and light has allowed to calculate the isotopic abundance of the metabolized CO 2 whose value has been compared to that of the intracellular water and that of photosynthetic oxygen. In addition, a new method using 13 C 18 O 2 gives the means to measure with accuracy eventual isotopic effects. The labelling kinetics of the oxygen evolved by Euglena suspensions whose water has been enriched with 18 O have been established at different temperatures. (author) [fr

IAEA technical co-operation with least developed Member States. Special evaluation

International Nuclear Information System (INIS)

1993-01-01

The main purposes of this evaluation were to: Review the overall situation with regard to IAEA technical co-operation with least developed Member States, including specific conditions in nuclear-related activities prevailing in these countries, approaches and practices used by the IAEA in providing assistance to LDCs, and the main results of the co-operation in question. Identify any adjustments to technical co-operation with LDC Member States that may strengthen this activity

Regional co-operation in the nuclear field: The Nordic experience

International Nuclear Information System (INIS)

Marcus, F.R.

1983-01-01

Experience from 25 years of co-operation in the nuclear field between the Nordic countries is described. A pragmatic approach with a minimum of formalism is used. The co-operation takes place mainly through ''horizontal'' channels between corresponding bodies in the different countries - safety authorities, research institutions, electricity producers, etc. In addition, a ''vertical'' co-ordination between these different circles is accomplished through a Nordic Liaison Committee. The experience shows that valuable results can be obtained, mainly through rationalization and improved use of resources. Difficulties, which are inherent in international co-operation, can be reduced, provided that there is a strong political will, an efficient system to promote contacts, and a flexible financing scheme. Apart from the benefits obtained in each of the countries - whether or not it has its own nuclear power - particular advantages accrue when a ''Nordic group'' can present co-ordinated viewpoints on the international scene. (author)

Steady-state kinetics of substrate binding and iron release in tomato ACC oxidase.

Science.gov (United States)

Thrower, J S; Blalock, R; Klinman, J P

2001-08-14

1-Aminocyclopropane-1-carboxylate oxidase (ACC oxidase) catalyzes the last step in the biosynthetic pathway of the plant hormone, ethylene. This unusual reaction results in the oxidative ring cleavage of 1-aminocyclopropane carboxylate (ACC) into ethylene, cyanide, and CO2 and requires ferrous ion, ascorbate, and molecular oxygen for catalysis. A new purification procedure and assay method have been developed for tomato ACC oxidase that result in greatly increased enzymatic activity. This method allowed us to determine the rate of iron release from the enzyme and the effect of the activator, CO2, on this rate. Initial velocity studies support an ordered kinetic mechanism where ACC binds first followed by O2; ascorbate can bind after O2 or possibly before ACC. This kinetic mechanism differs from one recently proposed for the ACC oxidase from avocado.

Oxygen permeation and thermo-chemical stability of oxygen separation membrane materials for the oxyfuel process

Energy Technology Data Exchange (ETDEWEB)

Ellett, Anna Judith

2009-07-01

The reduction of CO{sub 2} emissions, generally held to be one of the most significant contributors to global warming, is a major technological issue. CO{sub 2} Capture and Storage (CCS) techniques applied to large stationary sources such as coal-fired power plants could efficiently contribute to the global carbon mitigation effort. The oxyfuel process, which consists in the burning of coal in an oxygen-rich atmosphere to produce a flue gas highly concentrated in CO{sub 2}, is a technology considered for zero CO{sub 2} emission coal-fired power plants. The production of this O{sub 2}-rich combustion gas from air can be carried out using high purity oxygen separation membranes. Some of the most promising materials for this application are mixed ionic-electronic conducting (MIEC) materials with perovskite and K{sub 2}NiF{sub 4} perovskite-related structures. The present work examines the selection of La{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58), La{sub 2}NiO{sub 4+{delta}}, Pr{sub 0.58}Sr{sub 0.4}Co{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (PSCF58) and Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF50) as membrane materials for the separation of O{sub 2} and N{sub 2} in the framework of the oxyfuel process with flue gas recycling. Annealing experiments were carried out on pellets exposed to CO{sub 2}, water vapour, O{sub 2} and Cr{sub 2}O{sub 3} in order to determine the thermo-chemical resistance to the atmospheres and the high temperature conditions present during membrane operation in a coal-fired power plant. The degradation of their microstructure was investigated using Scanning Electron Microscopy (SEM) in combination with electron dispersive spectroscopy (EDS) as well as X-Ray Diffraction (XRD). Also, the oxygen permeation fluxes of selected membranes were investigated as a function of temperature. The membrane materials selected were characterised using thermo-analytical techniques such as precision thermogravimetric

Thermodynamics of ligand binding to acyl-coenzyme A binding protein studied by titration calorimetry

DEFF Research Database (Denmark)

Færgeman, Nils J.; Sigurskjold, B W; Kragelund, B B

1996-01-01

Ligand binding to recombinant bovine acyl-CoA binding protein (ACBP) was examined using isothermal microcalorimetry. Microcalorimetric measurements confirm that the binding affinity of acyl-CoA esters for ACBP is strongly dependent on the length of the acyl chain with a clear preference for acyl-...

Characterization and Expression of the Lucina pectinata Oxygen and Sulfide Binding Hemoglobin Genes

Science.gov (United States)

López-Garriga, Juan; Cadilla, Carmen L.

2016-01-01

The clam Lucina pectinata lives in sulfide-rich muds and houses intracellular symbiotic bacteria that need to be supplied with hydrogen sulfide and oxygen. This clam possesses three hemoglobins: hemoglobin I (HbI), a sulfide-reactive protein, and hemoglobin II (HbII) and III (HbIII), which are oxygen-reactive. We characterized the complete gene sequence and promoter regions for the oxygen reactive hemoglobins and the partial structure and promoters of the HbI gene from Lucina pectinata. We show that HbI has two mRNA variants, where the 5’end had either a sequence of 96 bp (long variant) or 37 bp (short variant). The gene structure of the oxygen reactive Hbs is defined by having 4-exons/3-introns with conservation of intron location at B12.2 and G7.0 and the presence of pre-coding introns, while the partial gene structure of HbI has the same intron conservation but appears to have a 5-exon/ 4-intron structure. A search for putative transcription factor binding sites (TFBSs) was done with the promoters for HbII, HbIII, HbI short and HbI long. The HbII, HbIII and HbI long promoters showed similar predicted TFBSs. We also characterized MITE-like elements in the HbI and HbII gene promoters and intronic regions that are similar to sequences found in other mollusk genomes. The gene expression levels of the clam Hbs, from sulfide-rich and sulfide-poor environments showed a significant decrease of expression in the symbiont-containing tissue for those clams in a sulfide-poor environment, suggesting that the sulfide concentration may be involved in the regulation of these proteins. Gene expression evaluation of the two HbI mRNA variants indicated that the longer variant is expressed at higher levels than the shorter variant in both environments. PMID:26824233

Polypyrrole/Co-tetraphenylporphyrin modified carbon fibre paper as a fuel cell electrocatalyst of oxygen reduction

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weimin; Chen, Jun; Wagner, Pawel; Wallace, Gordon G. [ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Wollongong NSW 2522 (Australia); Swiegers, Gerhard F. [CSIRO Molecular and Health Technologies, Bag 10, Clayton VIC 3169 (Australia)

2008-04-15

A thin-layer of polypyrrole (PPy) film, immobilized with neutral 5,10,15,20-tetraphenylporphyrinato cobalt (II) (Co-TPP), was successfully and uniformly deposited onto mesoporous carbon fibre paper (CFP) via vapor-phase polymerization. The resulting PPy/Co-TPP-modified carbon fibre paper (PPy/Co-TPP-CFP) electrode was characterized by cyclic voltammetry, SEM and EDX-ray mapping. Its electrochemical stability and long-term electrocatalytic performance were investigated in a half-fuel cell testing system. The electrode displayed significant electrocatalytic performance for oxygen reduction at 0.0 V (vs. Ag/AgCl), with notable long-term stability. (author)

Oxygen reduction kinetics and transport properties of (Ba,Sr)(Co,Fe)O3-δ solid oxide fuel cell cathode materials

International Nuclear Information System (INIS)

Wang, Lei; Merkle, Rotraut; Baumann, Frank S.; Maier, Joachim; Fleig, Juergen

2007-01-01

Full text: The oxygen reduction at the surface of cathode materials is crucial for the performance of solid oxide fuel cells (SOFC), but a detailed understanding of the mechanism is not available yet. (Ba x Sr 1-x )(Co 1-y Fe y )O 3-δ shows strongly improved oxygen reduction rates compared to previously applied perovskite cathode materials. In this work, surface rate constants as well as bulk transport properties are studied. (Ba x Sr 1-x )(Co 1-y Fe y )O 3-δ with 0≤x≤0.5, 0.2≤y≤1 was synthesized by the Pechini method. Oxygen stoichoimetry was obtained from thermo-gravimetric analysis, confirming that Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ has an exceptionally low oxygen content which is generally smaller than 2.5. Dense thin films were grown by pulsed laser deposition (PLD) and patterned into circular microelectrodes by photolithography. The surface resistance R s , which dominate the overall electrode resistance, were measured by impedance spectroscopy on individual microelectrodes at different T, pO 2 and applied electrical bias. PLD technique greatly helps to study the oxygen reduction kinetics since only measurements on dense thin films allow to record absolute R s values without interference from morphology effects. These R s values were found to be much lower than those for (La,Sr)(Co,Fe)O 3-δ . The variation of the surface reaction rates with A-site and B-site composition was studied and correlations with bulk materials properties such as oxygen nonstoichiometry, ionic mobility or oxidation enthalpy were examined. Plausible reaction mechanisms as well as possible reasons for the high absolute surface reaction rates will be discussed

Surface composition of magnetron sputtered Pt-Co thin film catalyst for proton exchange membrane fuel cells

Energy Technology Data Exchange (ETDEWEB)

Vorokhta, Mykhailo, E-mail: vorohtam@gmail.com [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Khalakhan, Ivan; Václavů, Michal [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Kovács, Gábor; Kozlov, Sergey M. [Departament de Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/ Martí i Franquès 1, 08028 Barcelona (Spain); Kúš, Peter; Skála, Tomáš; Tsud, Natalia; Lavková, Jaroslava [Charles University in Prague, Faculty of Mathematics and Physics, Department of Surface and Plasma Science, V Holešovičkách 2, 18000 Prague (Czech Republic); Potin, Valerie [Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS-Université Bourgogne, 9 Av. A. Savary, BP 47870, F-21078 Dijon Cedex (France); and others

2016-03-01

Graphical abstract: - Highlights: • Nanostructured Pt-Co thin catalyst films were grown on carbon by magnetron sputtering. • The surface composition of the nanostructured Pt-Co films was investigated by surface analysis techniques. • We carried out modeling of Pt-Co nanoalloys by computational methods. • Both experiment and modeling based on density functional theory showed that the surface of Pt-Co nanoparticles is almost exclusively composed of Pt atoms. - Abstract: Recently we have tested a magnetron sputtered Pt-Co catalyst in a hydrogen-fed proton exchange membrane fuel cell and showed its high catalytic activity for the oxygen reduction reaction. Here we present further investigation of the magnetron sputtered Pt-Co thin film catalyst by both experimental and theoretical methods. Scanning electron microscopy and transmission electron microscopy experiments confirmed the nanostructured character of the catalyst. The surface composition of as-deposited and annealed at 773 K Pt-Co films was investigated by surface analysis techniques, such as synchrotron radiation photoelectron spectroscopy and X-ray photoelectron spectroscopy. Modeling based on density functional theory showed that the surface of 6 nm large 1:1 Pt-Co nanoparticles is almost exclusively composed of Pt atoms (>90%) at typical operation conditions and the Co content does not exceed 20% at 773 K, in agreement with the experimental characterization of such films annealed in vacuum. According to experiment, the density of valence states of surface atoms in Pt-Co nanostructures is shifted by 0.3 eV to higher energies, which can be associated with their higher activity in the oxygen reduction reaction. The changes in electronic structure caused by alloying are also reflected in the measured Pt 4f, Co 3p and Co 2p photoelectron peak binding energies.

Assessment of the optimal operating parameters during extracorporeal CO2 removal with the Abylcap® system.

Science.gov (United States)

Eloot, Sunny; Peperstraete, Harlinde; De Somer, Filip; Hoste, Eric

2017-01-13

Lung protective ventilation is recommended in patients with acute respiratory distress syndrome (ARDS) needing mechanical ventilation. This can however be associated with hypercapnia and respiratory acidosis, such that extracorporeal CO2 removal (ECCO2R) can be applied. The aim of this study was to derive optimal operating parameters for the ECCO2R Abylcap® system (Bellco, Italy). We included 4 ARDS patients with a partial arterial oxygen tension over the fraction of inspired oxygen (PaO2/FiO2) lower than 150 mmHg, receiving lung-protective ventilation and treated with the Abylcap® via a double lumen 13.5-Fr dialysis catheter in the femoral vein. Every 24 hours during 5 consecutive days, blood was sampled at the Abylcap® inlet and outlet for different blood flows (QB:200-300-400 mL/min) with 100% O2 gas flow (QG) of 7 L/min, and for different QG (QG: 0.5-1-1.5-3-6-8 L/min) with QB400 mL/min. CO2 and O2 transfer remained constant over 5 days for a fixed QB. We found that, for a fixed QG of 7 L/min, CO2 transfer linearly and significantly increased with QB (i.e. from 58 ± 8 to 98 ± 16 mL/min for QB 200 to 400 mL/min). For a fixed QB of 400 mL/min, CO2 transfer non-linearly increased with QG (i.e. from 39 ± 9 to 98 ± 16 mL/min for QG 0.5 to 8 L/min) reaching a plateau at QG of 6 L/min. Hence, when using the Abylcap® ECCO2R in the treatment of ARDS patients the O2 flow should be at least 6 L/min while QB should be set at its maximum.

Method of controlling injection of oxygen into hydrogen-rich fuel cell feed stream

Science.gov (United States)

Meltser, Mark Alexander; Gutowski, Stanley; Weisbrod, Kirk

2001-01-01

A method of operating a H.sub.2 --O.sub.2 fuel cell fueled by hydrogen-rich fuel stream containing CO. The CO content is reduced to acceptable levels by injecting oxygen into the fuel gas stream. The amount of oxygen injected is controlled in relation to the CO content of the fuel gas, by a control strategy that involves (a) determining the CO content of the fuel stream at a first injection rate, (b) increasing the O.sub.2 injection rate, (c) determining the CO content of the stream at the higher injection rate, (d) further increasing the O.sub.2 injection rate if the second measured CO content is lower than the first measured CO content or reducing the O.sub.2 injection rate if the second measured CO content is greater than the first measured CO content, and (e) repeating steps a-d as needed to optimize CO consumption and minimize H.sub.2 consumption.

Oxygen isotope anomaly in tropospheric CO2 and implications for CO2 residence time in the atmosphere and gross primary productivity.

Science.gov (United States)

Liang, Mao-Chang; Mahata, Sasadhar; Laskar, Amzad H; Thiemens, Mark H; Newman, Sally

2017-10-13

The abundance variations of near surface atmospheric CO 2 isotopologues (primarily 16 O 12 C 16 O, 16 O 13 C 16 O, 17 O 12 C 16 O, and 18 O 12 C 16 O) represent an integrated signal from anthropogenic/biogeochemical processes, including fossil fuel burning, biospheric photosynthesis and respiration, hydrospheric isotope exchange with water, and stratospheric photochemistry. Oxygen isotopes, in particular, are affected by the carbon and water cycles. Being a useful tracer that directly probes governing processes in CO 2 biogeochemical cycles, Δ 17 O (=ln(1 + δ 17 O) - 0.516 × ln(1 + δ 18 O)) provides an alternative constraint on the strengths of the associated cycles involving CO 2 . Here, we analyze Δ 17 O data from four places (Taipei, Taiwan; South China Sea; La Jolla, United States; Jerusalem, Israel) in the northern hemisphere (with a total of 455 measurements) and find a rather narrow range (0.326 ± 0.005‰). A conservative estimate places a lower limit of 345 ± 70 PgC year -1 on the cycling flux between the terrestrial biosphere and atmosphere and infers a residence time of CO 2 of 1.9 ± 0.3 years (upper limit) in the atmosphere. A Monte Carlo simulation that takes various plant uptake scenarios into account yields a terrestrial gross primary productivity of 120 ± 30 PgC year -1 and soil invasion of 110 ± 30 PgC year -1 , providing a quantitative assessment utilizing the oxygen isotope anomaly for quantifying CO 2 cycling.

Mitigating operating room fires: development of a carbon dioxide fire prevention device.

Science.gov (United States)

Culp, William C; Kimbrough, Bradly A; Luna, Sarah; Maguddayao, Aris J

2014-04-01

Operating room fires are sentinel events that present a real danger to surgical patients and occur at least as frequently as wrong-sided surgery. For fire to occur, the 3 points of the fire triad must be present: an oxidizer, an ignition source, and fuel source. The electrosurgical unit (ESU) pencil triggers most operating room fires. Carbon dioxide (CO2) is a gas that prevents ignition and suppresses fire by displacing oxygen. We hypothesize that a device can be created to reduce operating room fires by generating a cone of CO2 around the ESU pencil tip. One such device was created by fabricating a divergent nozzle and connecting it to a CO2 source. This device was then placed over the ESU pencil, allowing the tip to be encased in a cone of CO2 gas. The device was then tested in 21%, 50%, and 100% oxygen environments. The ESU was activated at 50 W cut mode while placing the ESU pencil tip on a laparotomy sponge resting on an aluminum test plate for up to 30 seconds or until the sponge ignited. High-speed videography was used to identify time of ignition. Each test was performed in each oxygen environment 5 times with the device activated (CO2 flow 8 L/min) and with the device deactivated (no CO2 flow-control). In addition, 3-dimensional spatial mapping of CO2 concentrations was performed with a CO2 sampling device. The median ± SD [range] ignition time of the control group in 21% oxygen was 2.9 s ± 0.44 [2.3-3.0], in 50% oxygen 0.58 s ± 0.12 [0.47-0.73], and in 100% oxygen 0.48 s ± 0.50 [0.03-1.27]. Fires were ignited with each control trial (15/15); no fires ignited when the device was used (0/15, P fire prevention device can be created by using a divergent nozzle design through which CO2 passes, creating a cone of fire suppressant. This device as demonstrated in a flammability model effectively reduced the risk of fire. CO2 3-dimensional spatial mapping suggests effective fire reduction at least 1 cm away from the tip of the ESU pencil at 8 L/min CO2 flow

The modulation of oxygen vacancies by the combined current effect and temperature cycling in La0.7Sr0.3CoO3 film

Science.gov (United States)

Li, J.; Wang, J.; Kuang, H.; Zhao, Y. Y.; Qiao, K. M.; Liu, Y.; Hu, F. X.; Sun, J. R.; Shen, B. G.

2018-05-01

Modulating the oxygen defect concentration has been accepted as an effective method to obtain high catalytic activity in perovskite cobaltites. However, controllably modifying the oxygen vacancy is still a challenge in this type of materials, which strongly obstructs their application. Here, we report a successful oxygen vacancies modulation in the La0.7Sr0.3CoO3 (LSCO) film by using combined current effect and temperature cycling. The temperature dependent transport properties of the LSCO/LAO film were investigated. The results revealed that the resistance of the film keeps increasing under the repeated measurements. It was found that the accumulation of the oxygen vacancy by current effect transforms the Co4+ ion into Co3+ ion, which results in the enhancement of the resistance and thus the transport switching behavior. Moreover, the resistance in the cooling process was found to be much higher than that in previous cooling and heating processes, which indicates that the oxygen escapes more quickly in the high temperature region. On the other hand, our analysis indicates that the CoO6 distortion may contribute to the switching of transport behaviors in the low temperature region. Our work provides an effective and controllable way to modulate oxygen defect in the perovskite-type oxides.

Topotactic transition of α-Co(OH)2 to β-Co(OH)2 anchored on CoO nanoparticles during electrochemical water oxidation: synergistic electrocatalytic effects.

Science.gov (United States)

Kundu, Sumana; Malik, Bibhudatta; Prabhakaran, Amrutha; Pattanayak, Deepak K; Pillai, Vijayamohanan K

2017-08-29

Herein, we report a single step, anionic surfactant-assisted, low temperature-hydrothermal synthetic strategy of CoO nanoparticles anchored on β-Co(OH) 2 nanosheets which show a low overpotential (295 mV @ 10 mA cm -2 ) for the oxygen evolution reaction (OER). They also demonstrate much better kinetic parameters compared to the state-of-the-art RuO 2 . Interestingly, under the OER operational conditions (in alkaline medium), the topotactic transformation of α-Co(OH) 2 to a stable Brucite-like β-Co(OH) 2 phase leads to a synergistic interaction between the β-Co(OH) 2 sheets on the CoO nanoparticles for enhancing the OER electrocatalytic activity.

Understanding the Oxygen Evolution Reaction Mechanism on CoOx using Operando Ambient-Pressure X-ray Photoelectron Spectroscopy

International Nuclear Information System (INIS)

Favaro, Marco; Yang, Jinhui; Nappini, Silvia; Magnano, Elena

2017-01-01

Photoelectrochemical water splitting is a promising approach for renewable production of hydrogen from solar energy and requires interfacing advanced water-splitting catalysts with semiconductors. Understanding the mechanism of function of such electrocatalysts at the atomic scale and under realistic working conditions is a challenging, yet important, task for advancing efficient and stable function. This is particularly true for the case of oxygen evolution catalysts and, here, we study a highly active Co 3 O 4 /Co(OH) 2 biphasic electrocatalyst on Si by means of operando ambient-pressure X-ray photoelectron spectroscopy performed at the solid/liquid electrified interface. Spectral simulation and multiplet fitting reveal that the catalyst undergoes chemical-structural transformations as a function of the applied anodic potential, with complete conversion of the Co(OH) 2 and partial conversion of the spinel Co 3 O 4 phases to CoO(OH) under precatalytic electrochemical conditions. Furthermore, we observe new spectral features in both Co 2p and O 1s core-level regions to emerge under oxygen evolution reaction conditions on CoO(OH). The operando photoelectron spectra support assignment of these newly observed features to highly active Co 4+ centers under catalytic conditions. Comparison of these results to those from a pure phase spinel Co 3 O 4 catalyst supports this interpretation and reveals that the presence of Co(OH) 2 enhances catalytic activity by promoting transformations to CoO(OH). The direct investigation of electrified interfaces presented in this work can be extended to different materials under realistic catalytic conditions, thereby providing a powerful tool for mechanism discovery and an enabling capability for catalyst design.

Periodic density functional theory study of ethylene hydrogenation over Co3O4 (1 1 1) surface: The critical role of oxygen vacancies

International Nuclear Information System (INIS)

Lu, Jinhui; Song, JiaJia; Niu, Hongling; Pan, Lun; Zhang, Xiangwen; Wang, Li; Zou, Ji-Jun

2016-01-01

Highlights: • H 2 dissociates in heterolytic way following H atoms migration to form O−H bond. • H 2 dissociation occurs at low temperature on perfect and oxygen defective Co 3 O 4 . • Oxygen vacancy promotes hydrogenation thermodynamically and kinetically. • O−H bond is weakened on oxygen defective surface. • Hydrogenation requires compromise between H−H activation and O−H breakage. - Abstract: Recently, metal oxides are attracting increasing interests as hydrogenation catalyst. Herein we studied the hydrogenation of ethylene on perfect and oxygen defective Co 3 O 4 (1 1 1) using periodic density functional theory. The energetics and pathways of ethylene hydrogenation to ethane were determined. We have demonstrated that (i) H 2 dissociation on Co 3 O 4 is a complicated two-step process through a heterolytic cleavage, followed by the migration of H atom and finally yields the homolytic product on both perfect and oxygen defective Co 3 O 4 (1 1 1) surfaces easily. (ii) After introducing the surface oxygen vacancy, the stepwise hydrogenation of ethylene by atomic hydrogen is much easier than that on perfect surface due to the weaker bond strength of OH group. The strength of O−H bond is a crucial factor for the hydrogenation reaction which involves the breakage of O−H bond. The formation of oxygen vacancy increases the electronic charges at the adjacent surface O, which reduces its capability of further gaining electrons from adsorbed atomic hydrogen and then weakens the strength of O−H bond. These results emphasize the importance of the oxygen vacancies for hydrogenation on metal oxides.

Nature and Distribution of Stable Subsurface Oxygen in Copper Electrodes During Electrochemical CO2 Reduction

DEFF Research Database (Denmark)

Cavalca, Filippo Carlo; Ferragut, Rafael; Aghion, Stefano

2017-01-01

Oxide-derived copper (OD-Cu) electrodes exhibit higher activity than pristine copper during the carbon dioxide reduction reaction (CO2RR) and higher selectivity towards ethylene. The presence of residual subsurface oxygen in OD-Cu has been proposed to be responsible for such improvements, although...

Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine

International Nuclear Information System (INIS)

He Yuxian; Zhou Yusen; Liu Shuwen; Kou Zhihua; Li Wenhui; Farzan, Michael; Jiang Shibo

2004-01-01

The spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (CoV), a type I transmembrane envelope glycoprotein, consists of S1 and S2 domains responsible for virus binding and fusion, respectively. The S1 contains a receptor-binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. Here we show that a recombinant fusion protein (designated RBD-Fc) containing 193-amino acid RBD (residues 318-510) and a human IgG1 Fc fragment can induce highly potent antibody responses in the immunized rabbits. The antibodies recognized RBD on S1 domain and completely inhibited SARS-CoV infection at a serum dilution of 1:10,240. Rabbit antisera effectively blocked binding of S1, which contains RBD, to ACE2. This suggests that RBD can induce highly potent neutralizing antibody responses and has potential to be developed as an effective and safe subunit vaccine for prevention of SARS

Tuning affinity and reversibility for O₂ binding in dinuclear Co(II) complexes

DEFF Research Database (Denmark)

Vad, Mads Sørensen; Johansson, Frank Bartnik; Seidler-Egdal, Rune Kirk

2013-01-01

The O2 binding affinity of a series of dicobalt(II) complexes can be tuned between p(O2)50% = 2.3 × 10−3 and 700 × 10−3 atm at 40 °C by varying the number of H and Cl atoms in the bridging acetato ligands of [Co2(bpbp)(CH(3−n)ClnCO2)(CH3CN)2]2+, where bpbp− = 2,6-bis(N,N-bis(2-pyridylmethyl)amino...

Transformation of cooperative free energies between ligation systems of hemoglobin: resolution of the carbon monoxide binding intermediates.

Science.gov (United States)

Huang, Y; Ackers, G K

1996-01-23

A strategy has been developed for quantitatively "translating" the distributions of cooperative free energy between different oxygenation analogs of hemoglobin (Hb). The method was used to resolve the cooperative free energies of all eight carbon monoxide binding intermediates. These parameters of the FeCOHb system were determined by thermodynamic transformation of corresponding free energies obtained previously for all species of the Co/FeCO system, i.e., where cobalt-substituted hemes comprise the unligated sites [Speros, P. C., et al. (1991) Biochemistry 30, 7254-7262]. Using hybridized combinations of normal and cobalt-substituted Hb, ligation analog systems Co/FeX (X = CO, CN) were constructed and experimentally quantified. Energetics of cobalt-induced structural perturbation were determined for all species of both the "mixed metal" Co/Fe system and also the ligated Co/FeCN system. It was found that major energetic perturbations of the Co/Fe hybrid species originate from a pure cobalt substitution effect on the alpha subunits. These perturbations are transduced to the beta subunit within the same dimeric half-tetramer, resulting in alteration of the free energies for binding at the nonsubstituted (Fe) sites. Using the linkage strategy developed in this study along with the determined energetics of these couplings, the experimental assembly free energies for the Co/FeCO species were transformed into cooperative free energies of the 10 Fe/FeCO species. The resulting values were found to distribute according to predictions of a symmetry rule mechanism proposed previously [Ackers, G. K., et al. (1992) Science 255, 54-63]. Their distribution is consistent with accurate CO binding data of normal Hb [Perrella, M., et al. (1990b) Biophys. Chem. 37, 211-223] and also with accurate O2 binding data obtained under the same conditions [Chu, A. H., et al. (1984) Biochemistry 23, 604-617].

Non-transboundary pollution and the efficiency of international environmental co-operation

International Nuclear Information System (INIS)

Kox, Henk L.M.; Van der Tak, Casper M.

1996-01-01

The standard view is that situations where no transborder environmental externalities occur are most efficiently dealt with by national environmental policies rather than by international co-operation. Though this may be the general case, non-coordinated national policies do not always produce the most efficient international allocation. This paper presents four cases in which the allocative outcome of non-coordinated domestic policy choices can be improved upon by international environmental co-operation. The first case refers to the use of environmental policy as a strategic trade instrument. The other cases refer to the existence of discrete technologies, set-up costs and increasing returns to scale. The form of international environmental co-operation should be adapted to the situation. Formal international agreements between countries are characterised by high transaction costs and may not always be the most efficient form of co-operation

Ideological leaning and praxis of housing co-operatives in South Africa: Matters arising

Directory of Open Access Journals (Sweden)

Richard Jimoh

2013-06-01

Full Text Available Social movements came about as a result of dissatisfaction felt by society from the status quo. They present their grievances through demonstrations, strikes, riots, occupation of land, boycott of business or by the development of social and economic alternatives such as self-help schemes or saving clubs. In South Africa, people join housing co-operatives because it takes a long time to wait for the Reconstruction Development Project (RDP houses promised by the Government. The leaning of 5 housing co-operatives was examined within the context of ideology and praxis that are components of triad model. This was done through multi-case study whereby the chairpersons of the housing co-operatives were interviewed using structured interview format. Findings from the study indicated that all the housing co-operatives were not open and voluntary; also, the housing co-operatives were not administered the same way. In all, efforts were put in by the housing co-operatives in engendering the ideology of co-operatives on one hand and the government on the other hand in providing the necessary subsidy so that the gap in the housing deficit could be bridged since this fitted its policy on housing. 

Ideological leaning and praxis of housing co-operatives in South Africa: Matters arising

Directory of Open Access Journals (Sweden)

Richard Jimoh

2013-06-01

Full Text Available Social movements came about as a result of dissatisfaction felt by society from the status quo. They present their grievances through demonstrations, strikes, riots, occupation of land, boycott of business or by the development of social and economic alternatives such as self-help schemes or saving clubs. In South Africa, people join housing co-operatives because it takes a long time to wait for the Reconstruction Development Project (RDP houses promised by the Government. The leaning of 5 housing co-operatives was examined within the context of ideology and praxis that are components of triad model. This was done through multi-case study whereby the chairpersons of the housing co-operatives were interviewed using structured interview format. Findings from the study indicated that all the housing co-operatives were not open and voluntary; also, the housing co-operatives were not administered the same way. In all, efforts were put in by the housing co-operatives in engendering the ideology of co-operatives on one hand and the government on the other hand in providing the necessary subsidy so that the gap in the housing deficit could be bridged since this fitted its policy on housing.

Reversible operation of microtubular solid oxide cells using La0.6Sr0.4Co0.2Fe0.8O3-δ-Ce0.9Gd0.1O2-δ oxygen electrodes

Science.gov (United States)

López-Robledo, M. J.; Laguna-Bercero, M. A.; Larrea, A.; Orera, V. M.

2018-02-01

Yttria stabilized zirconia (YSZ) based microtubular solid oxide fuel cells (mT-SOFCs) using La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) and Ce0.9Gd0.1O2-δ (GDC) as the oxygen electrode, along with a porous GDC electrolyte-electrode barrier layer, were fabricated and characterized in both fuel cell (SOFC) and electrolysis (SOEC) operation modes. The cells were anode-supported, the NiO-YSZ microtubular supports being made by Powder Extrusion Moulding (PEM). The cells showed power densities of 695 mW cm-2 at 800 °C and 0.7 V in SOFC mode, and of 845 mA cm-2 at 800 °C and 1.3 V in SOEC mode. AC impedance experiments performed under different potential loads demonstrated the reversibility of the cells. These results showed that these cells, prepared with a method suitable for using on an industrial scale, are highly reproducible and reliable, as well as very competitive as reversible SOFC-SOEC devices operating at intermediate temperatures.

BANKING SYSTEM STABILITY: COMMERCIAL AND CO-OPERATIVE BANKS

Directory of Open Access Journals (Sweden)

Dumitru-Cristian OANEA

2014-04-01

Full Text Available Commercial banks and co-operative banks are credit institutions, but there are some differences between the main operations proceeded by each of them. Based on these specific characteristics, we want to identify the manner in which financial crisis affected their activity. As we all know, the financial crisis had a major impact in the United States, the “natal” country of the crisis, because great banks such as Lehman Brothers or Merrill Lynch have bankrupted. Even if the Romanian banking system was not affected by such catastrophic situations, surely the financial crisis had a significant impact on it. This topic is worth to be analysed, because we would be able to identify the risk differences between these two types of business: commercial banks versus co-operative banks.

Co-operatives in chains: institutional restructuring in the Dutch fruit and vegetables industry

NARCIS (Netherlands)

W.J.J. Bijman (Jos); G.W.J. Hendrikse (George)

2003-01-01

textabstractCo-operatives play a major role in the agricultural and food industry. Co-operatives, by the very nature, are producer-oriented firms. As market conditions for food products have changed in recent decades, the question is raised whether co-operatives are still efficient organisations for

The mystery of gold's chemical activity: local bonding, morphology and reactivity of atomic oxygen.

Science.gov (United States)

Baker, Thomas A; Liu, Xiaoying; Friend, Cynthia M

2011-01-07

Recently, gold has been intensely studied as a catalyst for key synthetic reactions. Gold is an attractive catalyst because, surprisingly, it is highly active and very selective for partial oxidation processes suggesting promise for energy-efficient "green" chemistry. The underlying origin of the high activity of Au is a controversial subject since metallic gold is commonly thought to be inert. Herein, we establish that one origin of the high activity for gold catalysis is the extremely reactive nature of atomic oxygen bound in 3-fold coordination sites on metallic gold. This is the predominant form of O at low concentrations on the surface, which is a strong indication that it is most relevant to catalytic conditions. Atomic oxygen bound to metallic Au in 3-fold sites has high activity for CO oxidation, oxidation of olefins, and oxidative transformations of alcohols and amines. Among the factors identified as important in Au-O interaction are the morphology of the surface, the local binding site of oxygen, and the degree of order of the oxygen overlayer. In this Perspective, we present an overview of both theory and experiments that identify the reactive forms of O and their associated charge density distributions and bond strengths. We also analyze and model the release of Au atoms induced by O binding to the surface. This rough surface also has the potential for O(2) dissociation, which is a critical step if Au is to be activated catalytically. We further show the strong parallels between product distributions and reactivity for O-covered Au at low pressure (ultrahigh vacuum) and for nanoporous Au catalysts operating at atmospheric pressure as evidence that atomic O is the active species under working catalytic conditions when metallic Au is present. We briefly discuss the possible contributions of oxidants that may contain intact O-O bonds and of the Au-metal oxide support interface in Au catalysis. Finally, the challenges and future directions for fully

Oxygen nonstoichiometry and ionic transport properties of La0.4Sr0.6CoO3-delta .

Science.gov (United States)

Sitte, W; Bucher, E; Benisek, A; Preis, W

2001-09-01

Homogeneous samples of La0.4Sr0.6CoO3-delta were obtained by the glycine nitrate process. The oxygen nonstoichiometry was determined from oxygen exchange measurements as a function of oxygen partial pressure (10(-4) bar PO2 PO2-range between 10(-4) and 10(-2) bar to yield D and the ionic conductivity sigma(i) from the long time solution of the diffusion equation. Values for D from polarization measurements at T= 775 degrees C and from oxygen exchange measurements at T= 725 degrees C are in good agreement with each other. D and sigma(1) increase with increasing PO2 (10(-4) to 10(-2) bar). The ionic conductivity shows a maximum at 3-delta approximately 2.82 and decreases with decreasing oxygen content indicating the possible formation of vacancy ordered structures.

Comparative study on membership legislation in Canadian and Chinese agricultural co-operative laws

Institute of Scientific and Technical Information of China (English)

CHU Zhihong; GUO Xiangyu

2007-01-01

For centuries, groups of people desiring to supply themselves with goods, to market their products, or to obtain services of various kinds on a co-operative basis, have made increasing use of co-operative associations to achieve these purposes. During the period, legislation designed especially for the incorporation and conduct of such associations has been enacted by different counties.Since a co-operative is established and carried on by and for the use of its members, this essay makes a comparison between Canadian and Chinese co-operative laws in terms of membership in the aspects of qualifications, rights and obligations and withdrawal of membership, so as to probe the function of co-operative legislation and find some enlightment from it.

International co-operation and the transfer of nuclear technology

International Nuclear Information System (INIS)

di Primio, J.C.

1977-01-01

The transfer of technology from developed countries is usually done through industrial enterprises. The local industrialization of imported technology does not necessarily imply that full benefit is extracted from its application. A pre-established scientific and technical infrastructure is needed to understand and incorporate it, and to develop methods for improvement and use at the industrial level, in the frame of national conditions. The transference of nuclear technology has recently shown new concepts for implementation. It is becoming a rule that massive industrial nuclear technology transfer to developing nations is tied to a requirement for simultaneous assistance in creating or promoting the infrastructure. An example of international co-operation to meet this requirement is the Argentine-German Agreement for the Peaceful Applications of Nuclear Energy. Since 1971 this has been used to strengthen the scientific and technical programmes of the Argentine Atomic Energy Commission in the relevant fields of industrial applications. The objectives and implementation of the agreement are described: co-operative actions were initially directed to the infrastructure needed to support the nuclear fuel cycle industry. The results achieved during the period 1971-1976 are critically analysed. This analysis has influenced the selection of future co-operative projects as well as the extension of the co-operation to other nuclear fields of common interest. (author)

Effect of high hydrostatic pressure on small oxygen-related clusters in silicon: LVM studies

International Nuclear Information System (INIS)

Murin, L.I.; Lindstroem, J.L.; Misiuk, A.

2003-01-01

Local vibrational mode (LVM) spectroscopy is used to explore the effect of high hydrostatic pressure (HP) on the formation of small oxygen-related clusters (dimers, trimers, thermal donors, and C-O complexes) at 450 deg. C and 650 deg. C in Cz-Si crystals with different impurity content and prehistory. It is found, in agreement with previous studies, that HP enhances the oxygen clustering in Cz-Si at elevated temperatures. The effect of HP is related mainly to enhancement in the diffusivity of single oxygen atoms and small oxygen aggregates. HP does not noticeably increase the binding energies of the most simple oxygen related complexes like O 2i , C s O ni . The biggest HP effect on the thermal double donor (TDDs) generation is revealed in hydrogenated samples. Heat-treatment of such samples at 450 deg. C under HP results in extremely high TDD introduction rates as well as in a strong increase in the concentration of the first TDD species

Temperature-dependent enthalpy of oxygenation in Antarctic fish hemoglobins

DEFF Research Database (Denmark)

Fago, A.; Wells, R.M.G.; Weber, Roy E.

1997-01-01

The effect of temperature on the oxygen-binding properties of the hemoglobins of three cold-adapted Antarctic fish species, Dissostichus mawsoni, Pagothenia borchgrevinki and Trematomus, sp., has been investigated under different pH values and buffer conditions. A clear non linear van't Hoff plot...... (logP(50) vs 1/T) of D. mawsoni hemoglobin indicates that the enthalpy of oxygenation (slope of the plot) is temperature dependent and that at high temperatures oxygen-binding becomes less exothermic. Nearly linear relationships were found in the hemoglobins of the other two species. The data were...... oxygen binding. The degree of the temperature dependence of the heat of oxygenation observed in these hemoglobins seems to reflect the differences in their allosteric effects rather than a specific molecular adaptation to low temperatures. Moreover, this study indicates that the disagreement between...

Tracking the Oxygen Status in the Cell Nucleus with a Hoechst-Tagged Phosphorescent Ruthenium Complex.

Science.gov (United States)

Hara, Daiki; Umehara, Yui; Son, Aoi; Asahi, Wataru; Misu, Sotaro; Kurihara, Ryohsuke; Kondo, Teruyuki; Tanabe, Kazuhito

2018-05-04

Molecular oxygen in living cells is distributed and consumed inhomogeneously, depending on the activity of each organelle. Therefore, tractable methods that can be used to monitor the oxygen status in each organelle are needed to understand cellular function. Here we report the design of a new oxygen-sensing probe for use in the cell nucleus. We prepared "Ru-Hoechsts", each consisting of a phosphorescent ruthenium complex linked to a Hoechst 33258 moiety, and characterized their properties as oxygen sensors. The Hoechst unit shows strong DNA-binding properties in the nucleus, and the ruthenium complex shows oxygen-dependent phosphorescence. Thus, Ru-Hoechsts accumulated in the cell nucleus and showed oxygen-dependent signals that could be monitored. Of the Ru-Hoechsts prepared in this study, Ru-Hoechst b, in which the ruthenium complex and the Hoechst unit were linked through a hexyl chain, showed the most suitable properties for monitoring the oxygen status. Ru-Hoechsts are probes with high potential for visualizing oxygen fluctuations in the nucleus. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

SSI's International Development Co-operation (SIUS). Annual report 1998

International Nuclear Information System (INIS)

Szendroe, G.; Grapengiesser, S.; Johansson, Gunnar

1999-04-01

SSI's International Development Co-operation (SIUS), the Swedish program for radiation protection work in Central and Eastern Europe, has since its start in 1992 been granted SEK 109 million by the Swedish government. The projects are accessed, planned and performed in close co-operation with partner organisations in Eastern Europe. This report presents the financial status and a summary of the projects, their status and distribution over the countries and project areas. The presentation is updated as of December 1998

Density functional theory study the effects of oxygen-containing functional groups on oxygen molecules and oxygen atoms adsorbed on carbonaceous materials.

Science.gov (United States)

Qi, Xuejun; Song, Wenwu; Shi, Jianwei

2017-01-01

Density functional theory was used to study the effects of different types of oxygen-containing functional groups on the adsorption of oxygen molecules and single active oxygen atoms on carbonaceous materials. During gasification or combustion reactions of carbonaceous materials, oxygen-containing functional groups such as hydroxyl(-OH), carbonyl(-CO), quinone(-O), and carboxyl(-COOH) are often present on the edge of graphite and can affect graphite's chemical properties. When oxygen-containing functional groups appear on a graphite surface, the oxygen molecules are strongly adsorbed onto the surface to form a four-member ring structure. At the same time, the O-O bond is greatly weakened and easily broken. The adsorption energy value indicates that the adsorption of oxygen molecules changes from physisorption to chemisorption for oxygen-containing functional groups on the edge of a graphite surface. In addition, our results indicate that the adsorption energy depends on the type of oxygen-containing functional group. When a single active oxygen atom is adsorbed on the bridge site of graphite, it gives rise to a stable epoxy structure. Epoxy can cause deformation of the graphite lattice due to the transition of graphite from sp2 to sp3 after the addition of an oxygen atom. For quinone group on the edge of graphite, oxygen atoms react with carbon atoms to form the precursor of CO2. Similarly, the single active oxygen atoms of carbonyl groups can interact with edge carbon atoms to form the precursor of CO2. The results show that oxygen-containing functional groups on graphite surfaces enhance the activity of graphite, which promotes adsorption on the graphite surface.

Finnish experience on emergency preparedness co-operation work and results

International Nuclear Information System (INIS)

Sovijarvi, Jukka

2014-01-01

Document available in abstract form only. According to the 'Security Strategy for Society' the responsibilities are shared across society and the normal division of duties shall be maintained unchanged as far as possible in all situations. While the competent authority is always in charge of making decisions other administrative sectors may be cooperation partners. This applies to the representatives of business community and organization as well. The first regional co-operation group for NPP emergency preparedness consisting of the representatives of regional rescue service, NPP licensee and STUK was established in 2008 to develop the external rescue plan, arrange training etc. Today co-operation groups are working for both Finnish emergency planning zones. Examples of the co-operation results are discussed in the presentation. (author)

Carbon coated (carbonous) catalyst in ebullated bed reactor for production of oxygenated chemicals from syngas/CO2

International Nuclear Information System (INIS)

Peizheng Zhou

2002-01-01

This report summarizes the work completed under DOE's Support of Advanced Fuel Research program, Contract No. DE-FG26-99FT40681. The contract period was October 2000 through September 2002. This R and D program investigated the modification of the mechanical strength of catalyst extrudates using Hydrocarbon Technologies, Inc. (HTI) carbon-coated catalyst technology so that the ebullated bed technology can be utilized to produce valuable oxygenated chemicals from syngas/CO 2 efficiently and economically. Exothermic chemical reactions benefit from the temperature control and freedom from catalyst fouling provided by the ebullated bed reactor technology. The carbon-coated extrudates prepared using these procedures had sufficient attrition resistance and surface area for use in ebullated bed operation. The low cost of carbon coating makes the carbon-coated catalysts highly competitive in the market of catalyst extrudates

Test Operation of Oxygen-Enriched Incinerator for Wastes From Nuclear Fuel Fabrication Facility

International Nuclear Information System (INIS)

Kim, J.-G.; Yang, H.cC.; Park, G.-I.; Kim, I.-T.; Kim, J.-K.

2002-01-01

The oxygen-enriched combustion concept, which can minimize off-gas production, has been applied to the incineration of combustible uranium-containing wastes from a nuclear fuel fabrication facility. A simulation for oxygen combustion shows the off-gas production can be reduced by a factor of 6.7 theoretically, compared with conventional air combustion. The laboratory-scale oxygen enriched incineration (OEI) process with a thermal capacity of 350 MJ/h is composed of an oxygen feeding and control system, a combustion chamber, a quencher, a ceramic filter, an induced draft fan, a condenser, a stack, an off-gas recycle path, and a measurement and control system. Test burning with cleaning paper and office paper in this OEI process shows that the thermal capacity is about 320 MJ/h, 90 % of design value and the off-gas reduces by a factor of 3.5, compared with air combustion. The CO concentration for oxygen combustion is lower than that of air combustion, while the O2 concentration in off-gas is kept above 25 vol % for a simple incineration process without any grate. The NOx concentration in an off-gas stream does not reduce significantly due to air incoming by leakage, and the volume and weight reduction factors are not changed significantly, which suggests a need for an improvement in sealing

Deep defect levels in standard and oxygen enriched silicon detectors before and after **6**0Co-gamma-irradiation

CERN Document Server

Stahl, J; Lindström, G; Pintilie, I

2003-01-01

Capacitance Deep Level Transient Spectroscopy (C-DLTS) measurements have been performed on standard and oxygen-doped silicon detectors manufactured from high-resistivity n-type float zone material with left angle bracket 111 right angle bracket and left angle bracket 100 right angle bracket orientation. Three different oxygen concentrations were achieved by the so-called diffusion oxygenated float zone (DOFZ) process initiated by the CERN-RD48 (ROSE) collaboration. Before the irradiation a material characterization has been performed. In contrast to radiation damage by neutrons or high- energy charged hadrons, were the bulk damage is dominated by a mixture of clusters and point defects, the bulk damage caused by **6**0Co-gamma-radiation is only due to the introduction of point defects. The dominant electrically active defects which have been detected after **6**0Co-gamma-irradiation by C-DLTS are the electron traps VO//i, C//iC//s, V//2( = /-), V //2(-/0) and the hole trap C//i O//i. The main difference betwe...

The receptor binding domain of MERS-CoV: The dawn of vaccine and treatment development

Directory of Open Access Journals (Sweden)

Nan Zhou

2014-03-01

Full Text Available The newly emerged Middle East respiratory syndrome coronavirus (MERS-CoV is becoming another “SARS-like” threat to the world. It has an extremely high death rate (∼50% as there is no vaccine or efficient therapeutics. The identification of the structures of both the MERS-CoV receptor binding domain (RBD and its complex with dipeptidyl peptidase 4 (DPP4, raises the hope of alleviating this currently severe situation. In this review, we examined the molecular basis of the RBD-receptor interaction to outline why/how could we use MERS-CoV RBD to develop vaccines and antiviral drugs.

NEA international co-operative projects

International Nuclear Information System (INIS)

1989-01-01

This text is consecrated at the international co-operative projects of the OECD Nuclear Energy Agency (NEA) in the field of reactor safety (Halden reactor project, Loft project, studies on the damaged Three Mile Island unit-2 reactor, inspection of reactor steel components, incident reporting system) and in the field of radioactive waste management (Stripa project, geochemical data bases, Alligator river project, seabed disposal of high-level radioactive waste, decommissioning of nuclear facilities)

Co-operation in nuclear development: The case of Hungary

International Nuclear Information System (INIS)

Kroen, H.

1990-01-01

Hungary became a Member of the IAEA in 1957 and has participated in the programme of technical assistance and co-operation from its start in 1958. By the end of 1976, Hungary ranked as the fifteenth largest recipient of IAEA technical assistance. Since then, there has been a significant increase in overall technical co-operation activities, and by the end of 1988 a total of over US $9.5 million of assistance had been received by Hungary, making it the fifth largest recipient of all Member States. In view of this situation, a special evaluation review was carried out in 1989 of the IAEA's technical co-operation programme in Hungary over the period 1976-1989. This evaluation review has shown that, simultaneously with the increase in the IAEA's support, there has been a rapid development in Hungary of the national nuclear infrastructure and this has permitted the country to absorb and utilize the assistance provided to the maximum extent. 7 figs

Synthesis, crystal structure and electrochemical and DNA binding studies of oxygen bridged-copper(II) carboxylate

Science.gov (United States)

Iqbal, Muhammad; Ali, Saqib; Tahir, Muhammad Nawaz; Muhammad, Niaz; Shah, Naseer Ali; Sohail, Manzar; Pandarinathan, Vedapriya

2015-08-01

A new binuclear O-bridged Cu(II) complex with 4-chlorophenyl acetate and 2,2‧-bipyridine has been synthesized and characterized using FT-IR, powder and single crystal XRD and electrochemical solution studies. The results revealed that the two penta-coordinated Cu(II) centers are linked by two carboxylate ligands in end-on bonding fashion. The coordination geometry is slightly distorted square pyramidal (SP) with bridging oxygen atoms occupying the apical position and other ligands lying in the equatorial plane. The striking difference in Cu-O bond distance of the bridging oxygen atom in the complex may be responsible for the SP geometry of Cu(II) ion. The complex gave rise to metal centered irreversible electro-activity where one electron Cu(II)/Cu(III) oxidation process and a single step two electron Cu(II)/Cu(0) reduction process was observed. The redox processes were found predominantly adsorption controlled. The values of diffusion coefficient and heterogeneous rate constant for oxidation process were 6.98 × 10-7 cm2 s-1 and 4.60 × 10-5 cm s-1 while the corresponding values for reduction were 5.30 × 10-8 cm2 s-1 and 5.41 × 10-6 cm s-1, respectively. The formal potential and charge transfer coefficient were also calculated. The DNA-binding ability was explored through cyclic voltammetry and UV-Visible spectroscopy. Diminution in the value of Do for oxidation indicated the binding of the complex with DNA corresponding to Kb = 8.58 × 104 M-1. UV-Visible spectroscopy yielded ε = 49 L mol-1 cm-1 and Kb = 2.96 × 104 M-1. The data of both techniques support each other. The self-induced redox activation of the complex, as indicated by cyclic voltammetry heralds its potential applications in redox catalysis and anticancer activity.

Inhibition of 3T3-L1 adipocyte differentiation by expression of acyl-CoA-binding protein antisense RNA

DEFF Research Database (Denmark)

Mandrup, S; Sorensen, R V; Helledie, T

1998-01-01

Several lines of evidence have recently underscored the significance of fatty acids or fatty acid-derived metabolites as signaling molecules in adipocyte differentiation. The acyl-CoA-binding protein (ACBP), which functions as an intracellular acyl-CoA pool former and transporter, is induced duri...

Local and Sustainable Food Supply: The Role of European Retail Consumer Co-operatives

Directory of Open Access Journals (Sweden)

Martin Hingley

2012-03-01

Full Text Available  This paper investigates the rationale for local and sustainable food systems and retailer co-operatives as their entry points within local conditions. Emphasis is on localised food networks and connection between socially as well as environmentally sustainable production, distribution and consumption. Investigated is the premise that co-operative organisational structures, for reasons of their long-term socially responsible origins are at the forefront of development of local and sustainable food systems and are thereby in a position to offer a specific contribution to market development. Two key research questions are proposed: Firstly, is there a pre-determination of co-operatives to issues of sustainable and local food sourcing given the historical and practical context of their ethical/socially responsible and stakeholder-based business model? Secondly, do co-ops express support for re-localising food systems and what contribution do they make concerning sustainable food and their relationships with local food suppliers? The method of investigation is through a two country retailer co-operative sector analysis and comparison (Finland and Italy. The enquiry is qualitative and exploratory in nature in the form of an embedded, multiple case design. The paper makes practical and theoretical contribution to knowledge concerning interpretation of ‘localness’ in food, the role of co-operatives and the co-operative ethos in sustainable food systems and the development of the local food economy. Results of the study show a positive relationship between co-operative ethos and (social sustainability in local food, but the de-centralised nature of retailer co-operation also provides a barrier to replication of good practice.

Oxygen adsorption on the Al9Co2(001) surface: first-principles and STM study

International Nuclear Information System (INIS)

Villaseca, S Alarcón; Loli, L N Serkovic; Ledieu, J; Fournée, V; Dubois, J-M; Gaudry, É; Gille, P

2013-01-01

Atomic oxygen adsorption on a pure aluminum terminated Al 9 Co 2 (001) surface is studied by first-principle calculations coupled with STM measurements. Relative adsorption energies of oxygen atoms have been calculated on different surface sites along with the associated STM images. The local electronic structure of the most favourable adsorption site is described. The preferential adsorption site is identified as a ‘bridge’ type site between the cluster entities exposed at the (001) surface termination. The Al–O bonding between the adsorbate and the substrate presents a covalent character, with s–p hybridization occurring between the states of the adsorbed oxygen atom and the aluminum atoms of the surface. The simulated STM image of the preferential adsorption site is in agreement with experimental observations. This work shows that oxygen adsorption generates important atomic relaxations of the topmost surface layer and that sub-surface cobalt atoms strongly influence the values of the adsorption energies. The calculated Al–O distances are in agreement with those reported in Al 2 O and Al 2 O 3 oxides and for oxygen adsorption on Al(111). (paper)

Oxygen- and hydrogen-permeation measurements on-mixed conducting SrFeCo{sub 0.5}O{sub y} ceramic membrane material

Energy Technology Data Exchange (ETDEWEB)

Serra, E.; Casagrande, E.; La Barbera, A. [ENEA UTS MAT, CR Casaccia, 00060 S.M. di Galeria, Roma (Italy); Alvisi, M. [ENEA UTS MAT, CR Brindisi, 72100 Brindisi (Italy); Bezzi, G.; Mingazzini, C. [ENEA UTS MAT, CR Faenza, 48018 Faenza (Italy)

2008-02-15

The SrFeCo{sub 0.5}O{sub y} system combines high electronic/ionic conductivity with appreciable oxygen permeability at elevated temperatures. This system has potential use in high-temperature electrochemical applications such as solid oxide fuel cells, batteries, sensors, and oxygen separation membranes. Dense ceramic membranes of SrFeCo{sub 0.5}O{sub y} are prepared by pressing a ceramic powder prepared by using a sol-gel combustion technique. Oxygen and hydrogen permeation at high temperature on this material are studied. Measurements are conducted using a time-dependent permeation method at the temperature in the range of 1073-1273 K with oxygen- and hydrogen-driving pressures in the range (3 x 10{sup 2})-(1 x 10{sup 5}) Pa (300-1000 mbar). The maximum oxygen-permeated flux at 1273 K is 6.5 x 10{sup -3} mol m{sup -2} s{sup -1}. The activation energies for the O{sub 2}-permeation fluxes and diffusivities are 240 and 194 kJ/mol, respectively. Due to the high fragility, the high temperature for the measurements and the high oxygen permeation through such material, a special membrane holder, and compression sealing system have been designed and realized for the permeation apparatus. (author)

Assessing the impacts of deoxygenation on marine species using blood-oxygen binding thresholds as proxies for hypoxia tolerance in the water column

Science.gov (United States)

Smith-Mislan, A.; Deutsch, C.; Dunne, J. P.; Sarmiento, J. L.

2016-02-01

Oxygen and temperature decrease, often rapidly, from shallow to deeper depths, restricting the ability of marine species to use the vertical habitat. One physiological trait that determines the tolerance of organisms to low oxygen is the oxygen affinity of respiratory pigments, hemoglobin and hemocyanin, in the blood. Oxygen affinity is sensitive to temperature because the reversible reaction between oxygen and blood pigments absorbs or releases energy, called the heat of oxygenation. To quantify the range of oxygen affinities for marine species, we surveyed the literature for measurements of oxygen binding to blood at multiple temperatures. Oxygen affinity is mapped within the ocean environment using the depth at which oxygen pressure decreases to the point at which the blood is 50% oxygenated (P50 depth) as organisms move from the surface to depth in the ocean water column. We calculate P50 depths for hydrographic observations and model simulations and find that vertical gradients in both temperature and oxygen impact the vertical position and areal extent of P50 depths. Shifts in P50 due to temperature cause physiological types with the same P50 in the surface ocean to have different P50 depths and physiological types with different P50's in the surface ocean to have the same P50 depth. The vertical distances between P50 depths are spatially variable, which may determine the frequency of ecological interactions, such as competition and predation. P50 depths provide new insights into the historical and future impacts of changing hypoxic zones on species living in pelagic habitats.

An effective device for gas-liquid oxygen removal in enclosed microalgae culture.

Science.gov (United States)

Su, Zhenfeng; Kang, Ruijuan; Shi, Shaoyuan; Cong, Wei; Cai, Zhaoling

2010-01-01

A high-performance gas-liquid transmission device (HPTD) was described in this paper. To investigate the HPTD mass transfer characteristics, the overall volumetric mass transfer coefficients, K(A)(La,CO(2)) for the absorption of gaseous CO(2) and K(A)(La,O(2)) for the desorption of dissolved O(2) were determined, respectively, by titration and dissolved oxygen electrode. The mass transfer capability of carbon dioxide was compared with that of dissolved oxygen in the device, and the operating conditions were optimized to suit for the large-scale enclosed micro-algae cultivation. Based on the effectiveness evaluation of the HPTD applied in one enclosed flat plate Spirulina culture system, it was confirmed that the HPTD can satisfy the demand of the enclosed system for carbon supplement and excessive oxygen removal.

Oxygen permeation flux through 10Sc1YSZ-MnCo2O4 asymmetric membranes prepared by two-step sintering

DEFF Research Database (Denmark)

Pirou, Stéven; Gurauskis, Jonas; Gil, Vanesa

2016-01-01

Asymmetric membranes based on a dual phase composite consisting of (Y2O3)0.01(Sc2O3)0.10(ZrO2)0.89 (10Sc1YSZ) as ionic conductor and MnCo2O4 as electronic conductor were prepared and characterized with respect to sinterability, microstructure and oxygen transport properties. The composite membranes...... were prepared by tape casting, lamination and fired in a two-step sintering process. Microstructural analysis showed that a gastight thin membrane layer with the desired ratio of ionic/electronic conducting phases could be fabricated. Oxygen permeation fluxes across the 10SclYSZ/MnCo2O4 (70/30 vol......%) composite membrane were measured from 750 to 940 degrees C using air or pure oxygen as feed gases and N2 or CO2 as sweep gases. Fluxes up to 2.3 mlN min-1 cm-2 were obtained for the 7 μm thick membrane. A degradation test over 1730 h showed an initial degradation of 21% during the first 1100 h after which...

Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys

Energy Technology Data Exchange (ETDEWEB)

Ham, Hyung Chul; Hwang, Gyeong S., E-mail: gshwang@che.utexas.edu [Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Manogaran, Dhivya [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States); Lee, Kang Hee; Jin, Seon-ah; You, Dae Jong; Pak, Chanho [Energy Lab, Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd., Suwon (Korea, Republic of); Kwon, Kyungjung [Department of Energy and Mineral Resources Engineering, Sejong University, Seoul 143-747 (Korea, Republic of)

2013-11-28

Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd{sub 3}Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity. Furthermore, our study suggests that the presence of Ir in the near-surface region can suppress Co out-diffusion from the Pd{sub 3}Co substrate, thereby improving the durability of Pd-Ir-Co catalysts. We also discuss the relative roles played by Ir and Co in enhancing the ORR activity relative to monometallic Pd catalysts.

Communication: Enhanced oxygen reduction reaction and its underlying mechanism in Pd-Ir-Co trimetallic alloys

International Nuclear Information System (INIS)

Ham, Hyung Chul; Hwang, Gyeong S.; Manogaran, Dhivya; Lee, Kang Hee; Jin, Seon-ah; You, Dae Jong; Pak, Chanho; Kwon, Kyungjung

2013-01-01

Based on a combined density functional theory and experimental study, we present that the electrochemical activity of Pd 3 Co alloy catalysts toward oxygen reduction reaction (ORR) can be enhanced by adding a small amount of Ir. While Ir tends to favorably exist in the subsurface layers, the underlying Ir atoms are found to cause a substantial modification in the surface electronic structure. As a consequence, we find that the activation barriers of O/OH hydrogenation reactions are noticeably lowered, which would be mainly responsible for the enhanced ORR activity. Furthermore, our study suggests that the presence of Ir in the near-surface region can suppress Co out-diffusion from the Pd 3 Co substrate, thereby improving the durability of Pd-Ir-Co catalysts. We also discuss the relative roles played by Ir and Co in enhancing the ORR activity relative to monometallic Pd catalysts

A proposed new mechanism for research and development co-operation

International Nuclear Information System (INIS)

Dolan, T.

2001-01-01

Scientists in developing countries sometimes lack knowledge of recent developments, co-operation with advanced countries, and government appreciation of the importance and quality of their work. The present IAEA mechanisms like CRPs and TC projects are very helpful but do not fully meet R and D co-operation needs of these scientists. A new complementary mechanism of co-operation among the Member States is proposed that would utilize IAEA services through a suitable agreement. The IAEA could help to evaluate joint R and D proposals, to provide an example legal agreement, to monitor progress, to disseminate the results, and, in some cases, to administer joint funds. This new mechanism would be similar to ITER, but on a smaller scale, and applicable to all fields of nuclear R and D. (author)

Periodic density functional theory study of ethylene hydrogenation over Co3O4 (1 1 1) surface: The critical role of oxygen vacancies

Science.gov (United States)

Lu, Jinhui; Song, JiaJia; Niu, Hongling; Pan, Lun; Zhang, Xiangwen; Wang, Li; Zou, Ji-Jun

2016-05-01

Recently, metal oxides are attracting increasing interests as hydrogenation catalyst. Herein we studied the hydrogenation of ethylene on perfect and oxygen defective Co3O4 (1 1 1) using periodic density functional theory. The energetics and pathways of ethylene hydrogenation to ethane were determined. We have demonstrated that (i) H2 dissociation on Co3O4 is a complicated two-step process through a heterolytic cleavage, followed by the migration of H atom and finally yields the homolytic product on both perfect and oxygen defective Co3O4 (1 1 1) surfaces easily. (ii) After introducing the surface oxygen vacancy, the stepwise hydrogenation of ethylene by atomic hydrogen is much easier than that on perfect surface due to the weaker bond strength of OH group. The strength of Osbnd H bond is a crucial factor for the hydrogenation reaction which involves the breakage of Osbnd H bond. The formation of oxygen vacancy increases the electronic charges at the adjacent surface O, which reduces its capability of further gaining electrons from adsorbed atomic hydrogen and then weakens the strength of Osbnd H bond. These results emphasize the importance of the oxygen vacancies for hydrogenation on metal oxides.

Electronic coupling induced high performance of N, S-codoped graphene supported CoS2 nanoparticles for catalytic reduction and evolution of oxygen

Science.gov (United States)

Chen, Bohong; Jiang, Zhongqing; Zhou, Lingshan; Deng, Binglu; Jiang, Zhong-Jie; Huang, Jianlin; Liu, Meilin

2018-06-01

A simple synthetic method is developed for the synthesis of CoS2/N, S-codoped graphene. The result shows the existence of a strong electronic coupling between CoS2 and N, S-codoped graphene. The pyrrolic and pyridinic type nitrogen and S in the form of C-S-C in N, S-codoped graphene are found to be the anchoring sites of the CoS2 nanoparticles. As a bifunctional catalyst, the CoS2/N, S-codoped graphene exhibits an oxygen reduction onset potential of 0.963 V vs. RHE and delivers an oxygen evolution overpotential of 393 mV at the current density of 10 mA cm-2. Its oxygen reduction and evolution catalytic activities are comparable to those of the Pt/C and the state-of-art RuO2/C, respectively. Most impressively, the CoS2/N, S-codoped graphene exhibits a potential gap of 771 mV. This value is lower than those of most bifuntional catalysts reported, clearly indicating its potential use as the bifunctional catalyst to replace the noble-metal based catalysts for practical applications. Additionally, our results also suggest a great importance to prepare a single pure phase CoS2 in improving the catalytic bifunctionality of the CoS2/N, S-codoped graphene. The primary Zn-air battery with CoS2/N, S-codoped graphene shows a higher discharge peak power density than that with Pt/C.

Stability of a Cu0.7Co2.3O4 electrode during the oxygen evolution reaction for alkaline anion-exchange membrane water electrolysis

Science.gov (United States)

Kang, Kyoung Eun; Kim, Chi Ho; Lee, Myung Sup; Jung, Chang Wook; Kim, Yang Do; Lee, Jae Ho

2018-01-01

The electrode materials for oxygen evolution, especially non-platinum group metal oxides, have attracted increasing attention. Among the spinel-type transition metal oxides, Cu0.7Co2.3O4 powders were evaluated as a potential replacement for expensive dimensionally stabilized anode materials. Cu0.7Co2.3O4 powder for use as an electrode material for oxygen evolution in an alkaline anion-exchange membrane water electrolyzer was prepared using a thermal decomposition method. The Cu0.7Co2.3O4 powders heat-treated at 250 °C exhibited the same X-ray diffraction patterns without any secondary phases as the Co3O4 spinel structure did. The Cu0.7Co2.3O4 powders heat-treated at 250 °C for 30 minutes showed the smallest mean particle size of approximately 376 nm with the powders having a homogeneous shape and size distribution. The fine powders with a relatively homogeneous size distribution showed a higher current density during the oxygen evolution reaction. The lifetime of the Cu0.7Co2.3O4 electrode was relatively long at a low current density, but was quickly shortened due to physical detachment of the Cu0.7Co2.3O4 powders as the current density was increased. This study showed that the efficiency and the stability of Cu0.7Co2.3O4 powders during the oxygen evolution reaction were related directly to the active electrode area.

Central Hemodynamics and Oxygen Transport in Various Activation of Patients Operated On Under Extracorporeal Circulation

Directory of Open Access Journals (Sweden)

Ye. V. Dzybinskaya

2009-01-01

Full Text Available Objective: to study central hemodynamics, the determinants of myocardial oxygen balance, and the parameters of oxygen transport in various activation of patients after surgery under extracorporeal circulation. Subjects and methods. Thirty-four patients aged 57.8±2.5 years who had coronary heart disease were divided into 2 groups: 1 those with late activation (artificial ventilation time 157±9 min and 2 those with immediate activation (artificial ventilation time 33±6 min. Group 2 patients were, if required, given fentanyl, midazolam, or myorelaxants. Results. During activation, there were no intergroup differences in the mean levels of the major parameters of cardiac pump function, in the determinants of coronary blood flow (coronary perfusion gradients and myocardial oxygen demand (the product of heart rate by systolic blood pressure, and in the parameters of oxygen transport, including arterial lactatemia. After tracheal extubation, the left ventricular pump coefficient was increased considerably (up to 3.8±0.2 and 4.4±0.2 gm/mm Hg/m2 in Groups 1 and 2, respectively; p<0.05 with minimum inotropic support (dopamine and/or dobutamine being used at 2.7±0.3 and 2.4±0.3 mg/kg/min, respectively. In both groups, there were no close correlations between the indices of oxygen delivery and consumption at all stages of the study, which was indicative of no transport-dependent oxygen uptake. Conclusion. When the early activation protocol was followed up, the maximum acceleration of early activation, including that using specific antagonists of anesthetics, has no negative impact on central hemodynamics, the determinants of myocardial oxygen balance and transport in patients operated on under extracorporeal circulation. Key words: early activation, surgery under extracorporeal circulation, tracheal extubation in the operating-room, central hemodynamics, oxygen transport.

FPGA Based Intelligent Co-operative Processor in Memory Architecture

DEFF Research Database (Denmark)

Ahmed, Zaki; Sotudeh, Reza; Hussain, Dil Muhammad Akbar

2011-01-01

benefits of PIM, a concept of Co-operative Intelligent Memory (CIM) was developed by the intelligent system group of University of Hertfordshire, based on the previously developed Co-operative Pseudo Intelligent Memory (CPIM). This paper provides an overview on previous works (CPIM, CIM) and realization......In a continuing effort to improve computer system performance, Processor-In-Memory (PIM) architecture has emerged as an alternative solution. PIM architecture incorporates computational units and control logic directly on the memory to provide immediate access to the data. To exploit the potential...

Restricted expression of Neuroglobin in the mouse retina and co-localization with Melanopsin and Tyrosine Hydroxylase

International Nuclear Information System (INIS)

Hundahl, C.A.; Fahrenkrug, J.; Luuk, H.; Hay-Schmidt, A.; Hannibal, J.

2012-01-01

Highlights: ► Restricted Neuroglobin expression in the mouse retina. ► Antibody validation using Neuroglobin-null mice. ► Co-expression of Neuroglobin with Melanopsin and tyrosine hydroxylase. ► No effect of Neuroglobin deficiency on neuronal survival. -- Abstract: Neuroglobin (Ngb), a neuronal specific oxygen binding heme-globin, reported to be expressed at high levels in most layers of the murine retina. Ngb’s function is presently unknown, but based on its high expression level and oxygen binding capabilities Ngb was proposed to function as an oxygen reservoir facilitating oxygen metabolism in highly active neurons or to function as a neuroprotectant. In the present study, we re-examined the expression pattern of Ngb in the retina using a highly validated antibody. Furthermore, intactness of retino-hypothalamic projections and the retinal expression level of Melanopsin and Tyrosine Hydroxylase were investigated in Ngb-null mice. Ngb-immunoreactivity was found in a few neurons of the ganglion cell and inner nuclear layers co-expressing Melanopsin and Tyrosine Hydroxylase, respectively. Ngb deficiency neither affected the level of Melanopsin and Tyrosine Hydroxylase proteins nor the intactness of PACAP-positive retinohypothalamic projections in the suprachiasmatic nucleus. Based on the present results, it seems unlikely that Ngb could have a major role in retinal oxygen homeostasis and neuronal survival under normal conditions. The present study suggests that a number of previously published reports have relied on antibodies with dubious specificity.

Restricted expression of Neuroglobin in the mouse retina and co-localization with Melanopsin and Tyrosine Hydroxylase

Energy Technology Data Exchange (ETDEWEB)

Hundahl, C.A., E-mail: c.hundahl@gmail.com [Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark); Centre of Excellence for Translational Medicine, University of Tartu, Tartu (Estonia); Department of Physiology, University of Tartu, Tartu (Estonia); Department of Neuroscience and Pharmacology, The Panum Institute, University of Copenhagen, Copenhagen (Denmark); Fahrenkrug, J. [Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark); Luuk, H. [Centre of Excellence for Translational Medicine, University of Tartu, Tartu (Estonia); Department of Physiology, University of Tartu, Tartu (Estonia); Hay-Schmidt, A. [Department of Neuroscience and Pharmacology, The Panum Institute, University of Copenhagen, Copenhagen (Denmark); Hannibal, J. [Department of Clinical Biochemistry, Bispebjerg Hospital, University of Copenhagen, Copenhagen (Denmark)

2012-08-17

Highlights: Black-Right-Pointing-Pointer Restricted Neuroglobin expression in the mouse retina. Black-Right-Pointing-Pointer Antibody validation using Neuroglobin-null mice. Black-Right-Pointing-Pointer Co-expression of Neuroglobin with Melanopsin and tyrosine hydroxylase. Black-Right-Pointing-Pointer No effect of Neuroglobin deficiency on neuronal survival. -- Abstract: Neuroglobin (Ngb), a neuronal specific oxygen binding heme-globin, reported to be expressed at high levels in most layers of the murine retina. Ngb's function is presently unknown, but based on its high expression level and oxygen binding capabilities Ngb was proposed to function as an oxygen reservoir facilitating oxygen metabolism in highly active neurons or to function as a neuroprotectant. In the present study, we re-examined the expression pattern of Ngb in the retina using a highly validated antibody. Furthermore, intactness of retino-hypothalamic projections and the retinal expression level of Melanopsin and Tyrosine Hydroxylase were investigated in Ngb-null mice. Ngb-immunoreactivity was found in a few neurons of the ganglion cell and inner nuclear layers co-expressing Melanopsin and Tyrosine Hydroxylase, respectively. Ngb deficiency neither affected the level of Melanopsin and Tyrosine Hydroxylase proteins nor the intactness of PACAP-positive retinohypothalamic projections in the suprachiasmatic nucleus. Based on the present results, it seems unlikely that Ngb could have a major role in retinal oxygen homeostasis and neuronal survival under normal conditions. The present study suggests that a number of previously published reports have relied on antibodies with dubious specificity.

Spin accumulation in Si channels using CoFe/MgO/Si and CoFe/AlOx/Si tunnel contacts with high quality tunnel barriers prepared by radical-oxygen annealing

International Nuclear Information System (INIS)

Akushichi, T.; Shuto, Y.; Sugahara, S.; Takamura, Y.

2015-01-01

We investigate spin injection into Si channels using three-terminal spin-accumulation (3T-SA) devices with high-quality CoFe/MgO/n-Si and CoFe/AlO x /n-Si tunnel spin-injectors whose tunnel barriers are formed by radical oxidation of Mg and Al thin films deposited on Si(100) substrates and successive annealing under radical-oxygen exposure. When the MgO and AlO x barriers are not treated by the radical-oxygen annealing, the Hanle-effect signals obtained from the 3T-SA devices are closely fitted by a single Lorentz function representing a signal due to trap spins. On the other hand, when the tunnel barriers are annealed under radical-oxygen exposure, the Hanle-effect signals can be accurately fitted by the superposition of a Lorentz function and a non-Lorentz function representing a signal due to accumulated spins in the Si channel. These results suggest that the quality improvement of tunnel barriers treated by radical-oxygen annealing is highly effective for spin-injection into Si channels

Ethanol flame synthesis of carbon nanotubes in deficient oxygen environments

Science.gov (United States)

Hu, Wei-Chieh; Lin, Ta-Hui

2016-04-01

In this study, carbon nanotubes (CNTs) were synthesized using ethanol diffusion flames in a stagnation-flow system composed of an upper oxidizer duct and a lower liquid pool. In the experiments, a gaseous mixture of oxygen and nitrogen flowed from the upper oxidizer duct, and then impinged onto the vertically aligned ethanol pool to generate a planar and steady diffusion flame in a deficient oxygen environment. A nascent nickel mesh was used as the catalytic metal substrate to collect deposited materials. The effect of low oxygen concentration on the formation of CNTs was explored. The oxygen concentration significantly influenced the flame environment and thus the synthesized carbon products. Lowering the oxygen concentration increased the yield, diameter, and uniformity of CNTs. The optimal operating conditions for CNT synthesis were an oxygen concentration in the range of 15%-19%, a flame temperature in the range of 460 °C-870 °C, and a sampling position of 0.5-1 mm below the upper edge of the blue flame front. It is noteworthy that the concentration gradient of C2 species and CO governed the CNT growth directly. CNTs were successfully fabricated in regions with uniform C2 species and CO distributions.

Do co-operative organisations contribute to a process of democratisation? : the case of Tanzania

OpenAIRE

Moberg, Liv

1998-01-01

Do co-operative organisations contribute to a process of democratisation? The Case of Tanzania May co-operative organisations be said to perform a role of any importance in processes of democratisation? The objective of my thesis is to answer this question theoretically and to illustrate with the case of Tanzania. It can thus be formulated in two parts; one theoretical and one empirical; May co-operative organisations contribute to a process of democratisation? Do co-operative organi...

Binding of corroded ions to human saliva.

Science.gov (United States)

Mueller, H J

1985-05-01

Employing equilibrium dialysis, the binding abilities of Cu, Al, Co and Cr ions from corroded Cu-Al and Co-Cr dental casting alloys towards human saliva and two of its gel chromatographic fractions were determined. Results indicate that both Cu and Co bind to human saliva i.e. 0.045 and 0.027 mg/mg protein, respectively. Besides possessing the largest binding ability, Cu also possessed the largest binding capacity. The saturation of Cu binding was not reached up to the limit of 0.35 mg protein/ml employed in the tests, while Co reached full saturation at about 0.2 mg protein/ml. Chromium showed absolutely no binding to human saliva while Al ions did not pass through the dialysis membranes. Compared to the binding with solutions that were synthetically made up to contain added salivary-type proteins, it is shown that the binding to human saliva is about 1 order of magnitude larger, at least for Cu ions.

HPC Co-operation between industry and university

International Nuclear Information System (INIS)

Ruhle, R.

2003-01-01

The full text of publication follows. Some years ago industry and university were using the same kind of high performance computers. Therefore it seemed appropriate to run the systems in common. Achieved synergies are larger systems to have better capabilities, to share skills in operating and using the system and to have less operating cost because of larger scale of operations. An example for a business model which allows that kind of co-operation would be demonstrated. Recently more and more simulations especially in the automotive industry are using PC clusters. A small number of PC's are used for one simulation, but the cluster is used for a large number of simulations as a throughput device. These devices are easily installed on the department level and it is difficult to achieve better cost on a central site, mainly because of the cost of the network. This is in contrast to the scientific need which still needs capability computing. In the presentation, strategies will be discussed for which cooperation potential in HPC (high performance computing) still exists. These are: to install heterogeneous computer farms, which allow to use the best computer for each application, to improve the quality of large scale simulation models to be used in design calculations or to form expert teams from industry and university to solve difficult problems in industry applications. Some examples of this co-operation are shown

Technical co-operation report for 2002. Report by the Director General

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-08-01

General Conference resolution GC(46)/RES/10 reiterated the need to strengthen the technical co- operation programme and requested the Director General to report to the Board of Governors periodically and to the General Conference at its forty-seventh (2003) session on the implementation of resolution GC(46)/RES/10. Part A of this report responds to the General Conference resolution by providing an overview of the progress achieved in technical co-operation policies, strategies, working relations, and internal management during the period 1 April 2002 to 31 March 2003, as well as the major new challenges facing the technical co-operation programme. Part B reports on operational activities and programme performance at the country and regional levels during the calendar year 2002, and Part C reviews the use of financial and human resources in the programme at an aggregate level. As part of its efforts to refine policies for improving programme development, the Agency reviewed the Technical Co-operation Strategy in 2002. The resulting document, The Technical Co-operation Strategy: the 2002 Review (document GOV/INF/2002/8/Mod.1), states that the strategic goal originally identified in the Strategy in 1997 remains valid, and defines four objectives to guide the technical co-operation programme: applying the central criterion (strong government commitment), developing strategic partnerships, increasing the level of funding for technical co-operation, and promoting greater sustainability and self-reliance of nuclear institutions. In line with the Technical Co-operation Strategy, one of the key features of the Agency.s work in 2002 was continuing consultations with Member States at both the policy and operational levels on the management of the ongoing technical co-operation programme and on planning for future activities. The dialogue with Member States aimed at clarifying the strategic objectives and key tools for the utilization of resources to achieve maximum

International co-operation in the nuclear field - past, present and prospects

International Nuclear Information System (INIS)

Goldschmidt, B.

1978-01-01

On the occasion of the 20th anniversary of its creation, the Nuclear Energy Agency of the Organization for Economic Co-operation and Development (NEA/OECD) held a symposium in Paris on 1 and 2 February 1978. Some 200 participants from the 23 Member countries of the NEA as well as representatives of the Commission of European Communities, FORATOM and the IAEA attended the symposium. At a panel discussion at the symposium, led by Dr. Sigvard Eklund, Director General of the IAEA, the future of international co-operation between advanced nations in the nuclear field was discussed. While recognizing that nuclear energy is at present going through a period of uncertainty pending resolution of the intertwined problems of gaining public confidence and of non-proliferation, the panel expressed its strong confidence in the future of nuclear power, and the vital contribution it would make, particularly between now and the end of the century. During the meeting, a critical review was made of the way in which international co-operation has evolved since the early stages of peaceful nuclear development, and of the influence on this co-operation of the changing relationship between government and industry. The contribution of international co-operation - and its limitations - was carefully scrutinized, notably in the crucial area of the nuclear fuel cycle

Oxygen reduction reaction on carbon-supported CoSe2 nanoparticles in an acidic medium

International Nuclear Information System (INIS)

Feng Yongjun; He Ting; Alonso-Vante, Nicolas

2009-01-01

We investigated the effect of CoSe 2 /C nanoparticle loading rate on oxygen reduction reaction (ORR) activity and H 2 O 2 production using the rotating disk electrode and the rotating ring-disk electrode techniques. We prepared carbon-supported CoSe 2 nanoparticles with different nominal loading rates and evaluated these samples by means of powder X-ray diffraction. All the catalysts had an OCP value of 0.81 V vs. RHE. H 2 O 2 production during the ORR process decreased with an increase in catalytic layer thickness. This decrease was related to the CoSe 2 loading on the disk electrode. H 2 O 2 production also decreased with increasing catalytic site density, a phenomenon related to the CoSe 2 loading rate on the carbon substrate. The cathodic current density significantly increased with increasing catalytic layer thickness, but decreased with increasing catalytic site density. In the case of 20 wt% CoSe 2 /C nanoparticles at 22 μg cm -2 , we determined that the transfer process involves about 3.5 electrons.

Co-Operative Training in the Sheffield Forging Industry

Science.gov (United States)

Duncan, R.

2008-01-01

Purpose: The purpose of this paper is to give details of an operation carried out in Sheffield to increase the recruitment of young men into the steel forging industry. Design/methodology/approach: The Sheffield Forges Co-operative Training Scheme was designed to encourage boys to enter the forging industry and to provide them with training and…

Recovery Act: Novel Oxygen Carriers for Coal-fueled Chemical Looping

Energy Technology Data Exchange (ETDEWEB)

Pan, Wei-Ping; Cao, Yan

2012-11-30

Chemical Looping Combustion (CLC) could totally negate the necessity of pure oxygen by using oxygen carriers for purification of CO{sub 2} stream during combustion. It splits the single fuel combustion reaction into two linked reactions using oxygen carriers. The two linked reactions are the oxidation of oxygen carriers in the air reactor using air, and the reduction of oxygen carriers in the fuel reactor using fuels (i.e. coal). Generally metal/metal oxides are used as oxygen carriers and operated in a cyclic mode. Chemical looping combustion significantly improves the energy conversion efficiency, in terms of the electricity generation, because it improves the reversibility of the fuel combustion process through two linked parallel processes, compared to the conventional combustion process, which is operated far away from its thermo-equilibrium. Under the current carbon-constraint environment, it has been a promising carbon capture technology in terms of fuel combustion for power generation. Its disadvantage is that it is less mature in terms of technological commercialization. In this DOE-funded project, accomplishment is made by developing a series of advanced copper-based oxygen carriers, with properties of the higher oxygen-transfer capability, a favorable thermodynamics to generate high purity of CO{sub 2}, the higher reactivity, the attrition-resistance, the thermal stability in red-ox cycles and the achievement of the auto-thermal heat balance. This will be achieved into three phases in three consecutive years. The selected oxygen carriers with final-determined formula were tested in a scaled-up 10kW coal-fueled chemical looping combustion facility. This scaled-up evaluation tests (2-day, 8-hour per day) indicated that, there was no tendency of agglomeration of copper-based oxygen carriers. Only trace-amount of coke or carbon deposits on the copper-based oxygen carriers in the fuel reactor. There was also no evidence to show the sulphidization of oxygen

Oxygen transport and degradation properties of high-temperature membranes for CO{sub 2}-free power plants; Sauerstofftransport und Degradationsverhalten von Hochtemperaturmembranen fuer CO{sub 2}-freie Kraftwerke

Energy Technology Data Exchange (ETDEWEB)

Schlehuber, Dominic

2010-07-01

This thesis deals with membranes for oxygen separation from air for high temperature application in fossil power plants within the scope of the oxyfuel-process. Different perovskite membrane materials (ABO3-ae) were investigated concerning the oxygen transport and their chemical stability under operation condition. The association between oxygen transport properties and both the thermodynamic boundary conditions as well as the material properties (membrane thickness and surface properties) was studied. One possibility to achieve higher oxygen fluxes through the membrane is to reduce the thickness. In this case the influence of surface processes on the overall permeation becomes noteworthy. The effect of different membrane surface modifications on the permeation rate was investigated. For example it could be confirmed, that a porous layer on the membrane surface significantly increases the permeation flux due to the compensation of surface exchange limitations. Beyond that, degradation processes during the operation under power plant condition were investigated. Special attention was attached to the influence of degradation on the permeation flux during long term operation. Thereby kinetic demixing of the membrane material was observed. (orig.)

Selective production of oxygenates from CO2 hydrogenation over mesoporous silica supported Cu-Ga nanocomposite catalyst

KAUST Repository

Huang, Kuo-Wei

2017-11-23

Carbon dioxide hydrogenation to oxygenates (methanol and dimethyl ether (DME)) was investigated over bifunctional supported copper catalysts promoted with gallium (Ga). Supported Cu-Ga nanocomposite catalysts were characterized by X-ray diffraction, transmission electron microscopy with energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and H2 temperature programmed reduction. In comparison with Cu-SBA-15 based catalysts, Ga promoted catalysts prepared by the urea deposition method (CuGa/SBA-15-UDP) was found active and selective for CO2 hydrogenation to oxygenates. The use of Ga as the promoter showed increased acidic sites as confirmed by the NH3-TPD, Pyridine-IR and 2,6-lutidine-IR studies. The favorable effect of Ga on CO2 conversion and selectivity to oxygenate may come from the strong interaction of Ga with silica, which is responsible for the enhanced metal surface area, formation of nanocomposite and metal dispersion. Notably, incorporation of Ga to Cu/SiO2 showed a several-fold higher rate for methanol formation (13.12 mol/gCu·sec) with a reasonable rate for the DME formation (2.15 mol/gCu·sec) as compared to those of Cu/SiO2 catalysts.

Oxygen excess in the '114' cobaltite hexagonal structure: The ferrimagnet CaBaCo4O7.50

International Nuclear Information System (INIS)

Pralong, V.; Caignaert, V.; Sarkar, T.; Lebedev, O.I.; Duffort, V.; Raveau, B.

2011-01-01

The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo 4 O 7 , using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo 4 O 7.50 , to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo 4 O 7 , is curiously similar to that of the members of the LnBaCo 4 O 7 series, in spite of its excess oxygen. Its magnetic study shows that this phase, like CaBaCo 4 O 7 , is ferrimagnetic with the same T C (60 K), but differently exhibits an unusual magnetic hysteresis. This exceptional behavior of CaBaCo 4 O 7 with respect to oxidation as well as the magnetic properties of CaBaCo 4 O 7.50 is interpreted in terms of the presence of defects due to oxidation. - Graphical Abstract: The study of the oxidation of the '114' orthorhombic cobaltite CaBaCo 4 O 7 , using first electrochemistry and then soft chemistry based on oxidation by NaClO, has allowed a new phase, CaBaCo 4 O 7.50 , to be prepared topotactically. The structural study of this phase shows that its hexagonal structure, closely related to that of orthorhombic CaBaCo 4 O 7 , is curiously similar to that of the members of the LnBaCo 4 O 7 series, in spite of its oxygen excess. Its magnetic study shows that this phase, like CaBaCo 4 O 7 , is ferrimagnetic. Highlights: → Topotactic oxidation by means of electrochemistry and soft chemistry of the '114' orthorhombic cobaltite CaBaCo 4 O 7 . → This new phase, CaBaCo 4 O 7.5 shows an hexagonal structure, is closely related to that of orthorhombic mother phase CaBaCo 4 O 7 . → CaBaCo 4 O 7.5 is ferrimagnetic and exhibits an unusual magnetic hysteresis, due to defect pinning centers.

Carbon and oxygen abundances in cool metal-rich exoplanet hosts: A case study of the C/O ratio of 55 Cancri

International Nuclear Information System (INIS)

Teske, Johanna K.; Cunha, Katia; Schuler, Simon C.; Griffith, Caitlin A.; Smith, Verne V.

2013-01-01

The super-Earth exoplanet 55 Cnc e, the smallest member of a five-planet system, has recently been observed to transit its host star. The radius estimates from transit observations, coupled with spectroscopic determinations of mass, provide constraints on its interior composition. The composition of exoplanetary interiors and atmospheres are particularly sensitive to elemental C/O ratio, which to first order can be estimated from the host stars. Results from a recent spectroscopic study analyzing the 6300 Å [O I] line and two C I lines suggest that 55 Cnc has a carbon-rich composition (C/O = 1.12 ± 0.09). However, oxygen abundances derived using the 6300 Å [O I] line are highly sensitive to a Ni I blend, particularly in metal-rich stars such as 55 Cnc ([Fe/H] =0.34 ± 0.18). Here, we further investigate 55 Cnc's composition by deriving the carbon and oxygen abundances from these and additional C and O absorption features. We find that the measured C/O ratio depends on the oxygen lines used. The C/O ratio that we derive based on the 6300 Å [O I] line alone is consistent with the previous value. Yet, our investigation of additional abundance indicators results in a mean C/O ratio of 0.78 ± 0.08. The lower C/O ratio of 55 Cnc determined here may place this system at the sensitive boundary between protoplanetary disk compositions giving rise to planets with high (>0.8) versus low (<0.8) C/O ratios. This study illustrates the caution that must applied when determining planet host star C/O ratios, particularly in cool, metal-rich stars.

Carbon Tolerant Fuel Electrodes for Reversible Sofc Operating on Carbon Dioxide

Directory of Open Access Journals (Sweden)

Papazisi Kalliopi Maria

2017-01-01

Full Text Available A challenging barrier for the broad, successful implementation of Reversible Solid Oxide Fuel Cell (RSOFC technology for Mars application utilizing CO2 from the Martian atmosphere as primary reactant, remains the long term stability by the effective control and minimization of degradation resulting from carbon built up. The perovskitic type oxide material La0.75Sr0.25Cr0.9Fe0.1O3-δ (LSCF has been developed and studied for its performance and tolerance to carbon deposition, employed as bi-functional fuel electrode in a Reversible SOFC operating on the CO2 cycle (Solid Oxide Electrolysis Cell/SOEC: CO2 electrolysis, Solid Oxide Fuel Cell/SOFC: power generation through the electrochemical reaction of CO and oxygen. A commercial state-of-the-art NiO-YSZ (8% mol Y2O3 stabilized ZrO2 cermet was used as reference material. CO2 electrolysis and fuel cell operation in 70% CO/CO2 were studied in the temperature range of 900-1000°C. YSZ was used as electrolyte while LSM-YSZ/LSM (La0.2Sr0.8MnO3 as oxygen electrode. Results showed that LSCF had high and stable performance under RSOFC operation.

Multi-yolk-shell SnO2/Co3Sn2@C Nanocubes with High Initial Coulombic Efficiency and Oxygen Reutilization for Lithium Storage.

Science.gov (United States)

Su, Liwei; Xu, Yawei; Xie, Jian; Wang, Lianbang; Wang, Yuanhao

2016-12-28

The challenging problems of SnO 2 anode material for lithium ion batteries are the poor electronic conductivity and the low oxygen reutilization due to the irreversibility of Li 2 O generated in the initial discharge leading to a theoretical initial Coulombic efficiency (ICE) of only 52.4%. Different from these strategies, this work proposes a novel strategy to level up the oxygen reutilization in SnO 2 by introducing Co 3 Sn 2 nanoalloys which can release Co atoms to reversibly react with Li 2 O instead. According to this protocol, multi-yolk-shell SnO 2 /Co 3 Sn 2 @C nanocubes are designed and successfully prepared using hollow CoSn(OH) 6 nanocubes as precursors followed a hydrothermal carbon coating and calcination treatment. The unique multi-yolk-shell nanostructure offers adequate breathing space for the volumetric deformation during long-term cycling. Moreover, the removal of Li 2 O allows a high electronic conductivity and resultant rate performance. As a result, the efficient reutilization of oxygen enables a high ICE of 71.7% and a reversible capacity of 1003 mA h g -1 after 200 cycles at 100 mA g -1 . Cyclic voltammetry, cycling performance at different voltage windows, and X-ray photoelectron spectroscopy confirm the proposed mechanism. This strategy employing oxygen-poor metals or alloys provides a novel approach to enhance the oxygen reutilization in SnO 2 for higher reversibility.

N, S co-doped carbon spheres with highly dispersed CoO as non-precious metal catalyst for oxygen reduction reaction

Science.gov (United States)

Chen, Linlin; Guo, Xingpeng; Zhang, Guoan

2017-08-01

It is still a great challenge in preparing non-precious metal catalysts with high activity and long-term stability to substitute for precious metal catalysts for oxygen reduction reaction (ORR) in fuel cells. Herein, we report a novel and facile catalyst-N, S co-doped carbon spheres with highly dispersed CoO (CoO@NS-CSs), where biomass glucose spheres act as carbon precursor and H2S, NH3 derived from the decomposition of thiourea not only provide N, S sources but also can etch carbon spheres to produce nanoporous structure. CoO@NS-CSs catalyst exhibits excellent ORR activity with a high onset potential of 0.946 V vs. RHE (reversible hydrogen electrode) and a half-wave potential of 0.821 V vs. RHE through a four-electron pathway in alkaline solution, which is comparable to commercial Pt/C catalyst (onset potential: 0.926 V vs. RHE, half-wave potential: 0.827 V vs. RHE). Furthermore, both the long-term stability and methanol-tolerance of CoO@NS-CSs catalyst are superior to those of commercial Pt/C catalyst. The excellent ORR performance of CoO@NS-CSs catalyst can be attributed to its micro-mesopore structure, high specific surface area (667 m2 g-1), and highly dispersed CoO. This work manifests that the obtained CoO@NS-CSs catalyst is promising to be applied to fuel cells.

Proceedings of International Symposium on Energy Co-operation in North East Asia

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-06-01

This proceedings are for the International Symposium on Energy Co-operation in North-East Asia, organized by Korea Energy Economics Institute, Institute of Energy Economics, Japan, and United Nations Economic and Social Commission for Asia and the Pacific, held on June 2001 at Sheraton Walker Hill Hotel in Seoul, Korea. The major themes discussed are following: 1.Energy Profile, Outlook and Perspectives on Regional Co-operation in Northeast Asia 2.Future Challenges in the Energy Sector in Northeast Asia 3.Perspectives of Energy Co-operation in Northeast Asia.

Co-operation agreement between the European Organization for Nuclear Research (CERN) and the Government of People's Republic of Bangladesh concerning Education, Scientific and Technical Co-operation in High-Energy Physics

CERN Document Server

2014-01-01

Co-operation agreement between the European Organization for Nuclear Research (CERN) and the Government of People's Republic of Bangladesh concerning Education, Scientific and Technical Co-operation in High-Energy Physics

Technical co-operation report for 2002. Report by the Director General

International Nuclear Information System (INIS)

2003-08-01

General Conference resolution GC(46)/RES/10 reiterated the need to strengthen the technical co- operation programme and requested the Director General to report to the Board of Governors periodically and to the General Conference at its forty-seventh (2003) session on the implementation of resolution GC(46)/RES/10. Part A of this report responds to the General Conference resolution by providing an overview of the progress achieved in technical co-operation policies, strategies, working relations, and internal management during the period 1 April 2002 to 31 March 2003, as well as the major new challenges facing the technical co-operation programme. Part B reports on operational activities and programme performance at the country and regional levels during the calendar year 2002, and Part C reviews the use of financial and human resources in the programme at an aggregate level. As part of its efforts to refine policies for improving programme development, the Agency reviewed the Technical Co-operation Strategy in 2002. The resulting document, The Technical Co-operation Strategy: the 2002 Review (document GOV/INF/2002/8/Mod.1), states that the strategic goal originally identified in the Strategy in 1997 remains valid, and defines four objectives to guide the technical co-operation programme: applying the central criterion (strong government commitment), developing strategic partnerships, increasing the level of funding for technical co-operation, and promoting greater sustainability and self-reliance of nuclear institutions. In line with the Technical Co-operation Strategy, one of the key features of the Agency.s work in 2002 was continuing consultations with Member States at both the policy and operational levels on the management of the ongoing technical co-operation programme and on planning for future activities. The dialogue with Member States aimed at clarifying the strategic objectives and key tools for the utilization of resources to achieve maximum

Case Writing Projects in Co-Operation with Companies and Organizations

OpenAIRE

Bengtsson, Lars; Asplund, Carl-Johan

2008-01-01

The purpose of this paper is to present the process and evaluation of case writing projects in co-operation with companies and organizations in a course for engineering students. The case writing projects could provide an illustration and example framework for working with companies in constructing cases. Normally cases are constructed for teaching purposes in higher education. However, in order to get closer co-operation and more interest from the companies the authors encouraged the student...

Enhanced room temperature ferromagnetism in electrodeposited Co-doped ZnO nanostructured thin films by controlling the oxygen vacancy defects

Energy Technology Data Exchange (ETDEWEB)

Simimol, A. [Nanomaterials Research Lab, Surface Engineering Division, CSIR-National Aerospace Laboratories, Post Bag No. 1779, Bangalore 560017 (India); Department of Physics, National Institute of Technology Calicut, Calicut 673601 (India); Anappara, Aji A. [Department of Physics, National Institute of Technology Calicut, Calicut 673601 (India); Greulich-Weber, S. [Department of Physics, Nanophotonic Materials, Faculty of Science, University of Paderborn, 33095 Paderborn (Germany); Chowdhury, Prasanta [Nanomaterials Research Lab, Surface Engineering Division, CSIR-National Aerospace Laboratories, Post Bag No. 1779, Bangalore 560017 (India); Barshilia, Harish C., E-mail: harish@nal.res.in

2015-06-07

We report the growth of un-doped and cobalt doped ZnO nanostructures fabricated on FTO coated glass substrates using electrodeposition method. A detailed study on the effects of dopant concentration on morphology, structural, optical, and magnetic properties of the ZnO nanostructures has been carried out systematically by varying the Co concentration (c.{sub Co}) from 0.01 to 1 mM. For c.{sub Co }≤ 0.2 mM, h-wurtzite phase with no secondary phases of Co were present in the ZnO nanostructures. For c.{sub Co} ≤ 0.2 mM, the photoluminescence spectra exhibited a decrease in the intensity of ultraviolet emission as well as band-gap narrowing with an increase in dopant concentration. All the doped samples displayed a broad emission in the visible range and its intensity increased with an increase in Co concentration. It was found that the defect centers such as oxygen vacancies and zinc interstitials were the source of the visible emission. The X-ray photoelectron spectroscopy studies revealed, Co was primarily in the divalent state, replacing the Zn ion inside the tetrahedral crystal site of ZnO without forming any cluster or secondary phases of Co. The un-doped ZnO nanorods exhibited diamagnetic behavior and it remained up to a c.{sub Co} of 0.05 mM, while for c.{sub Co }> 0.05 mM, the ZnO nanostructures exhibited ferromagnetic behavior at room temperature. The coercivity increased to 695 G for 0.2 mM Co-doped sample and then it decreased for c.{sub Co }> 0.2 mM. Our results illustrate that up to a threshold concentration of 0.2 mM, the strong ferromagnetism is due to the oxygen vacancy defects centers, which exist in the Co-doped ZnO nanostructures. The origin of strong ferromagnetism at room temperature in Co-doped ZnO nanostructures is attributed to the s-d exchange interaction between the localized spin moments resulting from the oxygen vacancies and d electrons of Co{sup 2+} ions. Our findings provide a new insight for tuning the

CD80 and CD86 IgC domains are important for quaternary structure, receptor binding and co-signaling function.

Science.gov (United States)

Girard, Tanya; Gaucher, Denis; El-Far, Mohamed; Breton, Gaëlle; Sékaly, Rafick-Pierre

2014-09-01

CD86 and CD80, the ligands for the co-stimulatory molecules CD28 and CTLA-4, are members of the Ig superfamily. Their structure includes Ig variable-like (IgV) domains, Ig constant-like (IgC) domains and intracellular domains. Although crystallographic studies have clearly identified the IgV domain to be responsible for receptor interactions, earlier studies suggested that both Ig domains are required for full co-signaling function. Herein, we have used deletion and chimeric human CD80 and CD86 molecules in co-stimulation assays to study the impact of the multimeric state of IgV and IgC domains on receptor binding properties and on co-stimulatory function in a peptide-specific T cell activation model. We report for the first time the presence of CD80 dimers and CD86 monomers in living cells. Moreover, we show that the IgC domain of both molecules inhibits multimer formation and greatly affects binding to the co-receptors CD28 and CTLA-4. Finally, both IgC and intracellular domains are required for full co-signaling function. These findings reveal the distinct but complementary roles of CD80 and CD86 IgV and IgC domains in T cell activation. Copyright © 2014 Elsevier B.V. All rights reserved.

Direct synthesis of bimetallic PtCo mesoporous nanospheres as efficient bifunctional electrocatalysts for both oxygen reduction reaction and methanol oxidation reaction

Science.gov (United States)

Wang, Hongjing; Yu, Hongjie; Li, Yinghao; Yin, Shuli; Xue, Hairong; Li, Xiaonian; Xu, You; Wang, Liang

2018-04-01

The engineering of electrocatalysts with high performance for cathodic and/or anodic catalytic reactions is of great urgency for the development of direct methanol fuel cells. Pt-based bimetallic alloys have recently received considerable attention in the field of fuel cells because of their superior catalytic performance towards both fuel molecule electro-oxidation and oxygen reduction. In this work, bimetallic PtCo mesoporous nanospheres (PtCo MNs) with uniform size and morphology have been prepared by a one-step method with a high yield. The as-made PtCo MNs show superior catalytic activities for both oxygen reduction reaction and methanol oxidation reaction relative to Pt MNs and commercial Pt/C catalyst, attributed to their mesoporous structure and bimetallic composition.

A unique mode of tissue oxygenation and the adaptive radiation of teleost fishes.

Science.gov (United States)

Randall, D J; Rummer, J L; Wilson, J M; Wang, S; Brauner, C J

2014-04-15

Teleost fishes constitute 95% of extant aquatic vertebrates, and we suggest that this is related in part to their unique mode of tissue oxygenation. We propose the following sequence of events in the evolution of their oxygen delivery system. First, loss of plasma-accessible carbonic anhydrase (CA) in the gill and venous circulations slowed the Jacobs-Stewart cycle and the transfer of acid between the plasma and the red blood cells (RBCs). This ameliorated the effects of a generalised acidosis (associated with an increased capacity for burst swimming) on haemoglobin (Hb)-O2 binding. Because RBC pH was uncoupled from plasma pH, the importance of Hb as a buffer was reduced. The decrease in buffering was mediated by a reduction in the number of histidine residues on the Hb molecule and resulted in enhanced coupling of O2 and CO2 transfer through the RBCs. In the absence of plasma CA, nearly all plasma bicarbonate ultimately dehydrated to CO2 occurred via the RBCs, and chloride/bicarbonate exchange was the rate-limiting step in CO2 excretion. This pattern of CO2 excretion across the gills resulted in disequilibrium states for CO2 hydration/dehydration reactions and thus elevated arterial and venous plasma bicarbonate levels. Plasma-accessible CA embedded in arterial endothelia was retained, which eliminated the localized bicarbonate disequilibrium forming CO2 that then moved into the RBCs. Consequently, RBC pH decreased which, in conjunction with pH-sensitive Bohr/Root Hbs, elevated arterial oxygen tensions and thus enhanced tissue oxygenation. Counter-current arrangement of capillaries (retia) at the eye and later the swim bladder evolved along with the gas gland at the swim bladder. Both arrangements enhanced and magnified CO2 and acid production and, therefore, oxygen secretion to those specialised tissues. The evolution of β-adrenergically stimulated RBC Na(+)/H(+) exchange protected gill O2 uptake during stress and further augmented plasma disequilibrium states

Temperature effects on hemocyanin oxygen binding in an antarctic cephalopod.

Science.gov (United States)

Zielinski, S; Sartoris, F J; Pörtner, H O

2001-02-01

The functional relevance of oxygen transport by hemocyanin of the Antarctic octopod Megaleledone senoi and of the eurythermal cuttlefish Sepia officinalis was analyzed by continuous and simultaneous recordings of changes in pH and hemocyanin oxygen saturation in whole blood at various temperatures. These data were compared to literature data on other temperate and cold-water cephalopods (octopods and giant squid). In S. officinalis, the oxygen affinity of hemocyanin changed at deltaP50/degrees C = 0.12 kPa (pH 7.4) with increasing temperatures; this is similar to observations in temperate octopods. In M. senoi, thermal sensitivity was much smaller (delta log P50/delta pH) increased with increasing temperature in both the cuttlefish and the Antarctic octopod. At low PO2 (1.0 kPa) and pH (7.2), the presence of a large venous oxygen reserve (43% saturation) insensitive to pH reflects reduced pH sensitivity and high oxygen affinity in M. senoi hemocyanin at 0 degrees C. In S. officinalis, this reserve was 19% at pH 7.4, 20 degrees C, and 1.7 kPa O2, a level still higher than in squid. These findings suggest that the lower metabolic rate of octopods and cuttlefish compared to squid is reflected in less pH-dependent oxygen transport. Results of the hemocyanin analysis for the Antarctic octopod were similar to those reported for Vampyroteuthis--an extremely high oxygen affinity supporting a very low metabolic rate. In contrast to findings in cold-adapted giant squid, the minimized thermal sensitivity of oxygen transport in Antarctic octopods will reduce metabolic scope and thereby contribute to their stenothermality.

Anisotropic Coulomb Explosion of CO Ligands in Group 6 Metal Hexacarbonyls: Cr(CO)6, Mo(CO)6, W(CO)6.

Science.gov (United States)

Tanaka, Hiroki; Nakashima, Nobuaki; Yatsuhashi, Tomoyuki

2016-09-08

Multiple ionization and subsequent Coulomb explosion have been studied for many organic molecules and their clusters; however, the metal complexes, particularly the large Coulombic interactions expected between a metal and its ligands, have not yet been explored. In this study, the angular distribution of CO(+), oxygen, and carbon ions ejected from metal hexacarbonyls (M(CO)6, M: Cr, Mo, W) having Oh symmetry by Coulomb explosion in femtosecond laser fields (>1 × 10(14) W cm(-2)) is investigated. The emissions of oxygen ions are well-explained in terms of the geometric alignment along a line inclined 45° relative to the CO-M-CO axis in a M(CO)4 plane. Unlike the explosion behavior of the oxygen ions located on the outer part of the molecule, the explosion behavior of the carbon ions was affected by the laser intensity, kinetic energy, and metal. This finding that the emission trends of carbon sandwiched between oxygen and metal atoms were the opposite of those for oxygen was explained by the obstruction by oxygen, the deformation of structure in bending coordinates, and the strong interaction with charged metal. The anisotropic Coulomb explosion of metal complexes reflecting their structural symmetry and central metal charge is a promising candidate for use in the investigation of large Coulombic interactions at the molecular level.

Properties and performance of BaxSr1-xCo0.8Fe0.2O3-d materials for oxygen transport membranes

NARCIS (Netherlands)

Vente, Jaap F.; McIntosh, S.; McIntosh, Steven; Haije, Wim G.; Bouwmeester, Henricus J.M.

2006-01-01

The present paper discusses the oxygen transport properties, oxygen stoichiometry, phase stability, and chemical and mechanical stability of the perovskites $${\\text{Ba}}_{{0.5}} {\\text{Sr}}_{{0.5}} {\\text{Co}}_{{0.8}} {\\text{Fe}}_{{0.2}} {\\text{O}}_{{3 - \\delta }} $$ (BSCF) and

Competition Between Co(NH3)63+ and Inner Sphere Mg2+ Ions in the HDV Ribozyme

Science.gov (United States)

Gong, Bo; Chen, Jui-Hui; Bevilacqua, Philip C.; Golden, Barbara L.; Carey, Paul R.

2009-01-01

Divalent cations play critical structural and functional roles in many RNAs. While the hepatitis delta virus (HDV) ribozyme can undergo self-cleavage in the presence of molar concentrations of monovalent cations, divalent cations such as Mg2+ are required for efficient catalysis under physiological conditions. Moreover, the cleavage reaction can be inhibited with Co(NH3)63+, an analog of Mg(H2O)62+. Here, the binding of Mg2+ and Co(NH3)63+ to the HDV ribozyme are studied by Raman microscopic analysis of crystals. Raman difference spectra acquired at different metal ion conditions reveal changes in the ribozyme. When Mg2+ alone is introduced to the ribozyme, inner sphere coordination of Mg(H2O)x2+ (x≤5) to non-bridging PO2− oxygen, and changes in base stretches and phosphodiester group conformation are observed. In addition, binding of Mg2+ induces deprotonation of a cytosine assigned to the general acid C75, consistent with solution studies. When Co(NH3)63+ alone is introduced, deprotonation of C75 is again observed, as are distinctive changes in base vibrational ring modes and phosphodiester backbone conformation. In contrast to Mg2+ binding, Co(NH3)63+ binding does not perturb PO2− group vibrations, consistent with its ability to make only outer sphere contacts. Surprisingly, competitive binding studies reveal that Co(NH3)63+ ions displace some inner sphere-coordinated magnesium species, including ions coordinated to PO2− groups or the N7 of a guanine, likely G1 at the active site. These observations contrast with the tenet that Co(NH3)63+ ions displace only outer sphere magnesium ions. Overall, our data support two classes of inner sphere Mg2+-PO2− binding sites: sites that Co(NH3)63+ can displace, and others it cannot. PMID:19888753

Oxygen transport by oxygen potential gradient in dense ceramic oxide membranes

Energy Technology Data Exchange (ETDEWEB)

Maiya, P.S.; Balachandran, U.; Dusek, J.T.; Mieville, R.L. [Argonne National Lab., IL (United States). Energy Technology Div.; Kleefisch, M.S.; Udovich, C.A. [Amoco Exploration/Production, Naperville, IL (United States)

1996-05-01

Numerous studies have been conducted in recent years on the partial oxidation of methane to synthesis gas (syngas: CO + H{sub 2}) with air as the oxidant. In partial oxidation, a mixed-oxide ceramic membrane selectively transports oxygen from the air; this transport is driven by the oxygen potential gradient. Of the several ceramic materials the authors have tested, a mixed oxide based on the Sr-Fe-Co-O system has been found to be very attractive. Extensive oxygen permeability data have been obtained for this material in methane conversion experiments carried out in a reactor. The data have been analyzed by a transport equation based on the phenomenological theory of diffusion under oxygen potential gradients. Thermodynamic calculations were used to estimate the driving force for the transport of oxygen ions. The results show that the transport equation deduced from the literature describes the permeability data reasonably well and can be used to determine the diffusion coefficients and the associated activation energy of oxygen ions in the ceramic membrane material.

Photochemistry Saturn's Atmosphere. 2; Effects of an Influx of External Oxygen

Science.gov (United States)

Moses, Julianne I.; Lellouch, Emmanuel; Bezard, Bruno; Gladstone, G. Randall; Allen, Mark

2000-01-01

We use a one-dimensional diurnally averaged model of photochemistry and diffusion in Saturn's stratosphere to investigate the influence of extraplanetary debris on atmospheric chemistry. In particular, we consider the effects of an influx of oxygen from micrometeoroid ablation or from ring-particle diffusion; the contribution from cometary impacts, satellite debris, or ring vapor is deemed to be less important. The photochemical model results are compared directly with Infrared Space Observatory (ISO) observations to constrain the influx of extraplanetary oxygen to Saturn. From the ISO observations, we determine that the column densities of CO2 and H2O above 10 mbar in Saturn's atmosphere are (6.3 +/- 1) x 10(exp 14) and (1.4 +/- 0.4) x 10(exp 15)/ square cm, respectively; our models indicate that a globally averaged oxygen influx of (4+/-2) x 10(exp 6) O atoms /sq cm/s is required to explain these observations. Models with a locally enhanced influx of H20 operating over a small fraction of the projected area do not provide as good a fit to the ISO H2O observations. If volatile oxygen compounds comprise one-third to one-half of the exogenic source by mass, then Saturn is currently being bombarded with (3 +/- 2) x 10(exp -16) g/square cm/s of extraplanetary material. To reproduce the observed CO2/H2O ratio in Saturn's stratosphere, some of the exogenic oxygen must arrive in the form of a carbon-oxygen bonded species such as CO or CO2. An influx consistent with the composition of cometary ices fails to reproduce the high observed CO2/H2O ratio, suggesting that (i) the material has ices that are slightly more carbon-rich than is typical for comets, (ii) a contribution from an organic-rich component is required, or (iii) some of the hydrogen-oxygen bonded material is converted to carbon-oxygen bonded material without photochemistry (e.g., during the ablation process). We have also reanalyzed the 5-micron CO observations of Noll and Larson and determine that the CO

Study on Characteristics of Co-firing Ammonia/Methane Fuels under Oxygen Enriched Combustion Conditions

Science.gov (United States)

Xiao, Hua; Wang, Zhaolin; Valera-Medina, Agustin; Bowen, Philip J.

2018-06-01

Having a background of utilising ammonia as an alternative fuel for power generation, exploring the feasibility of co-firing ammonia with methane is proposed to use ammonia to substitute conventional natural gas. However, improvement of the combustion of such fuels can be achieved using conditions that enable an increase of oxygenation, thus fomenting the combustion process of a slower reactive molecule as ammonia. Therefore, the present study looks at oxygen enriched combustion technologies, a proposed concept to improve the performance of ammonia/methane combustion. To investigate the characteristics of ammonia/methane combustion under oxygen enriched conditions, adiabatic burning velocity and burner stabilized laminar flame emissions were studied. Simulation results show that the oxygen enriched method can help to significantly enhance the propagation of ammonia/methane combustion without changing the emission level, which would be quite promising for the design of systems using this fuel for practical applications. Furthermore, to produce low computational-cost flame chemistry for detailed numerical analyses for future combustion studies, three reduced combustion mechanisms of the well-known Konnov's mechanism were compared in ammonia/methane flame simulations under practical gas turbine combustor conditions. Results show that the reduced reaction mechanisms can provide good results for further analyses of oxygen enriched combustion of ammonia/methane. The results obtained in this study also allow gas turbine designers and modellers to choose the most suitable mechanism for further combustion studies and development.

Assuring nuclear energy's future through international co-operation

International Nuclear Information System (INIS)

Upson, P.

1999-01-01

It is invited lecture as the introduction to the sixt international meeting entitled Nuclear Energy in Central Europe. Good commercial operation, public information and education are needed to win the confidence of the public, and to attract young people to take over the industry's founding generation. Stimulating international co-operation and transfer of best practices can assure this happens across the whole of the Europian nuclear industry

Process analysis of an oxygen lean oxy-fuel power plant with co-production of synthesis gas

International Nuclear Information System (INIS)

Normann, Fredrik; Thunman, Henrik; Johnsson, Filip

2009-01-01

This paper investigates new possibilities and synergy effects for an oxy-fuel fired polygeneration scheme (transportation fuel and electricity) with carbon capture and co-firing of biomass. The proposed process has the potential to make the oxy-fuel process more effective through a sub-stoichiometric combustion in-between normal combustion and gasification, which lowers the need for oxygen within the process. The sub-stoichiometric combustion yields production of synthesis gas, which is utilised in an integrated synthesis to dimethyl ether (DME). The process is kept CO 2 neutral through co-combustion of biomass in the process. The proposed scheme is simulated with a computer model with a previous study of an oxy-fuel power plant as a reference process. The degree of sub-stoichiometric combustion, or amount of synthesis gas produced, is optimised with respect to the overall efficiency. The maximal efficiency was found at a stoichiometric ratio just below 0.6 with the efficiency for the electricity producing oxy-fuel process of 0.35 and a DME process efficiency of 0.63. It can be concluded that the proposed oxygen lean combustion process constitutes a way to improve the oxy-fuel carbon capture processes with an efficient production of DME in a polygeneration process

Realities of technical co-operation in the peaceful uses of nuclear energy

International Nuclear Information System (INIS)

Luxo, A.; Villaros, P.; Naudet, G.

1978-01-01

The decision to develop the peaceful uses of nuclear energy, especially the generation of electricity, is usually based - particularly in the developing countries - on numerous considerations, mainly of an economic and political nature. Since the resources of nuclear technology are concentrated, relatively speaking, in the advanced countries, the use of nuclear energy by countries that have decided to go nuclear is based on effective co-operation between the exporting and importing countries. The present paper is intended as an additional contribution to consideration of the realities of such co-operation. The authors first mention the specific features of nuclear development, after which they consider, on the basis thereof, the different forms of co-operation required for the transfer of technological knowhow, and the conditions determining the effectiveness of such transfer. This effectiveness is not linked solely to the competence of the personnel concerned or to smooth organizational procedures, but also to decisive socio-psychological factors. Having analysed these factors, the authors examine the salient problems of co-operation arising during the process of nuclear development. Co-operation ever better adapted to the purpose and taking human considerations into account will enable importing countries to acquire the nuclear knowhow that will promote their economic and social development. (author)

Screening of catalytic oxygen reduction reaction activity of metal-doped graphene by density functional theory

International Nuclear Information System (INIS)

Chen, Xin; Chen, Shuangjing; Wang, Jinyu

2016-01-01

Highlights: • The screened M-G structures are very thermodynamically stable, and the stability is even higher than that of the corresponding bulk metal surfaces. • The binding energies of ORR intermediates suggest that they are not linear dependence, which are different form the cases found on some metal-based catalysts. • The Au-, Co-, and Ag-G structures could be used as the ORR catalysts. - Abstract: Graphene doping is a promising direction for developing effective oxygen reduction reaction (ORR) catalysts. In this paper, we computationally investigated the ORR performance of 10 kinds of metal-doped graphene (M-G) catalysts, namely, Al-, Si-, Mn-, Fe-, Co-, Ni-, Pd-, Ag-, Pt-, and Au-G. The results shown that the binding energies of the metal atoms incorporated into the graphene vacancy are higher than their bulk cohesive energies, indicating the formed M-G catalysts are even more stable than the corresponding bulk metal surfaces, and thus avoid the metals dissolution in the reaction environment. We demonstrated that the linear relation among the binding energies of the ORR intermediates that found on metal-based materials does not hold for the M-G catalysts, therefore a single binding energy of intermediate alone is not sufficient to evaluate the ORR activity of an arbitrary catalyst. By analysis of the detailed ORR processes, we predicted that the Au-, Co-, and Ag-G materials can be used as the ORR catalysts.

Carbon supported Pd-Co-Mo alloy as an alternative to Pt for oxygen reduction in direct ethanol fuel cells

Energy Technology Data Exchange (ETDEWEB)

Rao, Ch. Venkateswara [National Centre for Catalysis Research, Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, TN (India); Viswanathan, B., E-mail: bvnathan@acer.iitm.ernet.i [National Centre for Catalysis Research, Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, TN (India)

2010-03-01

Carbon black (CDX975) supported Pd and Pd-Co-Mo alloy nanoparticles are prepared by the reduction of metal precursors with hydrazine in reverse microemulsion of water/Triton-X-100/propanol-2/cyclohexane. The as-synthesized Pd-Co-Mo/CDX975 is heat treated at 973, 1073 and 1173 K to promote alloy formation. The prepared materials are characterized by powder XRD and EDX. Face-centred cubic structure of Pd is evident from XRD. The chemical composition of the respective elements in the catalysts is evaluated from the EDX analysis and observed that it is in good agreement with initial metal precursor concentrations. Oxygen reduction measurements performed by linear sweep voltammetry indicate the good catalytic activity of Pd-Co-Mo alloys compared to Pd. This is due to the suppression of (hydr)oxy species on Pd surface by the presence of alloying elements, Co and Mo. Among the investigated catalysts, heat-treated Pd-Co-Mo/CDX975 at 973 K exhibited good ORR activity compared to the catalysts heat treated at 1073 and 1173 K. This is due to the small crystallite size and high surface area. Rotating disk electrode (RDE) measurements indicated the comparable ORR activity of heat-treated Pd-Co-Mo/CDX975 at 973 K with that of commercial Pt/C. Kinetic analysis reveals that the ORR on Pd-Co-Mo/CDX975 follows the four-electron pathway leading to water. Moreover, Pd-Co-Mo/CDX975 exhibited substantially higher ethanol tolerance during the ORR than Pt/C. Good dispersion of metallic nanoparticles on the carbon support is observed from HRTEM images. Single-cell direct ethanol fuel cell tests indicated the comparable performance of Pd-Co-Mo/CDX975 with that of commercial Pt/C. Stability under DEFC operating conditions for 50 h indicated the good stability of Pd-Co-Mo/CDX975 compared with that of Pt/C.

SSI`s International Development Co-operation (SIUS). Annual report 1998

Energy Technology Data Exchange (ETDEWEB)

Szendroe, G.; Grapengiesser, S.; Johansson, Gunnar

1999-04-01

SSI`s International Development Co-operation (SIUS), the Swedish program for radiation protection work in Central and Eastern Europe, has since its start in 1992 been granted SEK 109 million by the Swedish government. The projects are accessed, planned and performed in close co-operation with partner organisations in Eastern Europe. This report presents the financial status and a summary of the projects, their status and distribution over the countries and project areas. The presentation is updated as of December 1998

Process integration of chemical looping combustion with oxygen uncoupling in a coal-fired power plant

International Nuclear Information System (INIS)

Spinelli, Maurizio; Peltola, Petteri; Bischi, Aldo; Ritvanen, Jouni; Hyppänen, Timo; Romano, Matteo C.

2016-01-01

High-temperature solid looping processes for CCS (carbon capture and storage) represent a class of promising technologies that enables CO2 capture with relatively low net efficiency penalties. The novel concept of the CLOU (Chemical Looping with Oxygen Uncoupling) process is based on a system of two interconnected fluidized bed reactors that operate at atmospheric pressure. In the fuel reactor, the capability of certain metal oxides to spontaneously release molecular oxygen at high temperatures is exploited to promote the direct conversion of coal in an oxygen-rich atmosphere. As a novel CO_2 capture concept, the CLOU process requires the optimization of design and operation parameters, which may substantially influence the total power plant performance. This study approaches this issue by performing joint simulations of CLOU reactors using a 1.5D model and a steam cycle power plant. A sensitivity analysis has been performed to investigate the performance and main technical issues that are related to the integration of a CLOU island in a state-of-the-art USC (ultra-supercritical) power plant. In particular, the effect of the key process parameters has been evaluated. Superior performance has been estimated for the power plant, with electrical efficiencies of approximately 42% and more than 95% CO2 avoided. - Highlights: • Process modeling and simulation of CLOU integrated in USC coal power plant carried out. • Comprehensive sensitivity analysis on Cu-based CLOU process performed. • Electrical efficiencies of 42% and more than 95% CO_2 avoided obtained. • Reactor size and operating conditions suitable for industrial applications.

Beyond Public and Private: A Framework for Co-operative Higher Education

Directory of Open Access Journals (Sweden)

Mike Neary

2017-07-01

Full Text Available Universities in the UK are increasingly adopting corporate governance structures, a consumerist model of teaching and learning, and have the most expensive tuition fees in the world (McGettigan, 2013; OECD, 2015. This article discusses collaborative research that aimed to develop and define a conceptual framework of knowledge production grounded in co-operative values and principles. The main findings are outlined relating to the key themes of our research: knowledge, democracy, bureaucracy, livelihood, and solidarity. We consider how these five ‘catalytic principles’ relate to three identified routes to co-operative higher education (conversion, dissolution, or creation and argue that such work must be grounded in an adequate critique of labour and property, i.e. the capital relation. We identify both the possible opportunities that the latest higher education reform in the UK affords the co-operative movement as well as the issues that arise from a more marketised and financialised approach to the production of knowledge (HEFCE, 2015. Finally, we suggest ways that the co-operative movement might respond with democratic alternatives that go beyond the distinction of public and private education.

Anisotropic Oxygen Ion Diffusion in Layered PrBaCo 2 O 5+δ

KAUST Repository

Burriel, Mónica

2012-02-14

Oxygen diffusion and surface exchange coefficients have been measured on polycrystalline samples of the double perovskite oxide PrBaCo 2O 5+δ by the isotope exchange depth profile method, using a time-of-flight SIMS instrument. The measured diffusion coefficients show an activation energy of 1.02 eV, as compared to 0.89 eV for the surface exchange coefficients in the temperature range from 300 to 670 °C. Inhomogeneity was observed in the distribution of the oxygen-18 isotopic fraction from grain to grain in the ceramic samples, which was attributed to anisotropy in the diffusion and exchange of oxygen. By the use of a novel combination of electron back scattered diffraction measurements, time-of-flight, and focused ion beam SIMS, this anisotropy was confirmed by in-depth analysis of single grains of known orientation in a ceramic sample exchanged at 300 °C. Diffusion was shown to be faster in a grain oriented with the surface normal close to 100 and 010 (ab-plane oriented) than a grain with a surface normal close to 001 (c-axis oriented). The magnitude of this anisotropy is estimated to be close to a factor of 4, but this is only a lower bound due to experimental limitations. These findings are consistent with recent molecular dynamic simulations of this material where anisotropy in the oxygen transport was predicted. © 2012 American Chemical Society.

Anisotropic Oxygen Ion Diffusion in Layered PrBaCo 2 O 5+δ

KAUST Repository

Burriel, Mó nica; Peñ a-Martí nez, Juan; Chater, Richard J.; Fearn, Sarah; Berenov, Andrey V.; Skinner, Stephen J.; Kilner, John A.

2012-01-01

Oxygen diffusion and surface exchange coefficients have been measured on polycrystalline samples of the double perovskite oxide PrBaCo 2O 5+δ by the isotope exchange depth profile method, using a time-of-flight SIMS instrument. The measured diffusion coefficients show an activation energy of 1.02 eV, as compared to 0.89 eV for the surface exchange coefficients in the temperature range from 300 to 670 °C. Inhomogeneity was observed in the distribution of the oxygen-18 isotopic fraction from grain to grain in the ceramic samples, which was attributed to anisotropy in the diffusion and exchange of oxygen. By the use of a novel combination of electron back scattered diffraction measurements, time-of-flight, and focused ion beam SIMS, this anisotropy was confirmed by in-depth analysis of single grains of known orientation in a ceramic sample exchanged at 300 °C. Diffusion was shown to be faster in a grain oriented with the surface normal close to 100 and 010 (ab-plane oriented) than a grain with a surface normal close to 001 (c-axis oriented). The magnitude of this anisotropy is estimated to be close to a factor of 4, but this is only a lower bound due to experimental limitations. These findings are consistent with recent molecular dynamic simulations of this material where anisotropy in the oxygen transport was predicted. © 2012 American Chemical Society.

Regional co-operation in radioactive waste management from an IAEA perspective

International Nuclear Information System (INIS)

Bonne, A.

2000-01-01

This paper is intended to be a lead in to a Round Table discussion on Regional Co-operation in Radioactive Waste Management at the International Conference on N uclear Option in Countries with Small and Medium Electricity Grids , which will be held from 19 to 22 June 2000 in Dubrovnik, Croatia. The Round Table discussion will focus on international co-operation in the Eastern European region

Oxygen as a factor in eukaryote evolution - Some effects of low levels of oxygen on Saccharomyces cerevisiae

Science.gov (United States)

Jahnke, L.; Klein, H. P.

1979-01-01

A comparative study of the effects of varying levels of oxygen on some of the metabolic functions of the primitive eukaryote, Saccharomyces cerevisiae, has shown that these cells are responsive to very low levels of oxygen: the level of palmitoyl-Co A desaturase was greatly enhanced by only 0.03 vol % oxygen. Similarly, an acetyl-CoA synthetase associated predominantly with anaerobic growth was stimulated by as little as 0.1% oxygen, while an isoenzyme correlated with aerobic growth was maximally active at much higher oxygen levels (greater than 1%). Closely following this latter pattern were three mitochondrial enzymes that attained maximal activity only under atmospheric levels of oxygen.

An oxygen pressure sensor using surface acoustic wave devices

Science.gov (United States)

Leighty, Bradley D.; Upchurch, Billy T.; Oglesby, Donald M.

1993-01-01

Surface acoustic wave (SAW) piezoelectric devices are finding widespread applications in many arenas, particularly in the area of chemical sensing. We have developed an oxygen pressure sensor based on coating a SAW device with an oxygen binding agent which can be tailored to provide variable sensitivity. The coating is prepared by dissolving an oxygen binding agent in a toluene solution of a copolymer which is then sprayed onto the surface of the SAW device. Experimental data shows the feasibility of tailoring sensors to measure the partial pressure of oxygen from 2.6 to 67 KPa (20 to 500 torr). Potential applications of this technology are discussed.

Hierarchical interactions between Fnr orthologs allows fine-tuning of transcription in response to oxygen in Herbaspirillum seropedicae.

Science.gov (United States)

Batista, Marcelo Bueno; Chandra, Govind; Monteiro, Rose Adele; de Souza, Emanuel Maltempi; Dixon, Ray

2018-05-04

Bacteria adjust the composition of their electron transport chain (ETC) to efficiently adapt to oxygen gradients. This involves differential expression of various ETC components to optimize energy generation. In Herbaspirillum seropedicae, reprogramming of gene expression in response to oxygen availability is controlled at the transcriptional level by three Fnr orthologs. Here, we characterised Fnr regulons using a combination of RNA-Seq and ChIP-Seq analysis. We found that Fnr1 and Fnr3 directly regulate discrete groups of promoters (Groups I and II, respectively), and that a third group (Group III) is co-regulated by both transcription factors. Comparison of DNA binding motifs between the three promoter groups suggests Group III promoters are potentially co-activated by Fnr3-Fnr1 heterodimers. Specific interaction between Fnr1 and Fnr3, detected in two-hybrid assays, was dependent on conserved residues in their dimerization interfaces, indicative of heterodimer formation in vivo. The requirements for co-activation of the fnr1 promoter, belonging to Group III, suggest either sequential activation by Fnr3 and Fnr1 homodimers or the involvement of Fnr3-Fnr1 heterodimers. Analysis of Fnr proteins with swapped activation domains provides evidence that co-activation by Fnr1 and Fnr3 at Group III promoters optimises interactions with RNA polymerase to fine-tune transcription in response to prevailing oxygen concentrations.

Textile Inspired Lithium-Oxygen Battery Cathode with Decoupled Oxygen and Electrolyte Pathways.

Science.gov (United States)

Xu, Shaomao; Yao, Yonggang; Guo, Yuanyuan; Zeng, Xiaoqiao; Lacey, Steven D; Song, Huiyu; Chen, Chaoji; Li, Yiju; Dai, Jiaqi; Wang, Yanbin; Chen, Yanan; Liu, Boyang; Fu, Kun; Amine, Khalil; Lu, Jun; Hu, Liangbing

2018-01-01

The lithium-air (Li-O 2 ) battery has been deemed one of the most promising next-generation energy-storage devices due to its ultrahigh energy density. However, in conventional porous carbon-air cathodes, the oxygen gas and electrolyte often compete for transport pathways, which limit battery performance. Here, a novel textile-based air cathode is developed with a triple-phase structure to improve overall battery performance. The hierarchical structure of the conductive textile network leads to decoupled pathways for oxygen gas and electrolyte: oxygen flows through the woven mesh while the electrolyte diffuses along the textile fibers. Due to noncompetitive transport, the textile-based Li-O 2 cathode exhibits a high discharge capacity of 8.6 mAh cm -2 , a low overpotential of 1.15 V, and stable operation exceeding 50 cycles. The textile-based structure can be applied to a range of applications (fuel cells, water splitting, and redox flow batteries) that involve multiple phase reactions. The reported decoupled transport pathway design also spurs potential toward flexible/wearable Li-O 2 batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Outlook for the IAEA's technical co-operation programme

International Nuclear Information System (INIS)

Samiei, Massoud

1998-01-01

This is a slide presentation dealing with the following subjects: - the IAEA's programmes; - the technical co-operation programme; - past trends in the TC programme; - new initiatives in TC; - TC programme profile; - perspectives for the future. The major programmes conducted by IAEA are concerning: - nuclear power and fuel cycle; - nuclear applications; - nuclear, radiation and waste safety, nuclear verification and security material; - management of technical co-operation; - policy making, coordination and support. In relation with the IAEA role in development process the author presents the legal framework for TC, the programme structure, and programme areas, resources, budgets, cycle, approval and implementation. Two plots regarding the recipients with and without NPP's are displayed for the period 1980-1994. Also, according to the status of the member states (without and with nuclear power programme) the programme priorities are presented. For the first case these are: radiation and waste safety, food and agriculture, water resources management human health and nutrition, human resources development, environmental protection and industrial applications. For the second case there are mentioned: radiation and nuclear safety, nuclear power operation and maintenance management, radioactive waste management, environment protection and sustainable energy options. Concerning the regional distribution the following figures are given for 1997: West Asia, 9%; Europe, 18%; Inter-regional, 11%; Africa, 24%; Latin America, 21%; East Asia and Pacific, 17%. In conclusion, the hope is expressed that the value of Technical Co-operation Programme would be seen not only in the successful transfer of technology but also, in the way that the nuclear technologies may satisfy demands for sustainable development by having a lasting impact on the life of the majority in a cost effective and environmentally sound manner

Supercritical CO2 test loop operation and first test results

International Nuclear Information System (INIS)

Wright, Steven A.; Pickard, Paul S.

2009-01-01

The DOE Office of Nuclear Energy is investigating advanced Brayton cycles for use with next generation nuclear power plants. The focus of this work is on the supercritical CO 2 Brayton cycle which has the potential for high efficiency, and for reduced capital costs due to very compact turbomachinery. Sandia has fabricated and is operating a supercritical CO 2 (S-CO 2 ) test loop to investigate the key technology issues associated with this cycle. This loop is part of a multi-year phased development program to develop a megawatt (MW) class closed S-CO 2 Brayton cycle to demonstrate the applicability of this cycle for DOE Gen-IV program. The current loop has been configured as both a compression loop and as simple heated but unrecuperated Brayton cycle. A second split-flow or re-compression Brayton cycle is currently under development that will use approximately 1 MW of heat to run the Brayton cycle. Early configurations of this split-flow Brayton cycle will be operational later this fiscal year. The key issues for this cycle include the fundamental issues of compressor fluid performance and system control near the critical point, but also the supporting technology issues of bearings, sealing technologies, and rotor windage losses which are also essential to achieving efficiency and cost objectives. These tests are providing the first measurements and information on these key supercritical CO 2 power conversion systems questions. Important data for all these issues has been obtained. This report presents the major results of the testing by showing and comparing the measured compressor performance map with the predicted performance. The compression loop uses a ∼50 kWe motor driven compressor to spin a 37 mm OD compressor at design speeds up to 75,000 rpm with a pressure ratio of 1.8 and a flow rate of 3.53 kg/s for a compressor inlet condition of 305.3 K and 7690 kPa. The most recent configuration of this loop has added a small turbine and 260 kW of heater power is

A mixture of "cheats" and "co-operators" can enable maximal group benefit.

Directory of Open Access Journals (Sweden)

R Craig MaClean

Full Text Available Is a group best off if everyone co-operates? Theory often considers this to be so (e.g. the "conspiracy of doves", this understanding underpinning social and economic policy. We observe, however, that after competition between "cheat" and "co-operator" strains of yeast, population fitness is maximized under co-existence. To address whether this might just be a peculiarity of our experimental system or a result with broader applicability, we assemble, benchmark, dissect, and test a systems model. This reveals the conditions necessary to recover the unexpected result. These are 3-fold: (a that resources are used inefficiently when they are abundant, (b that the amount of co-operation needed cannot be accurately assessed, and (c the population is structured, such that co-operators receive more of the resource than the cheats. Relaxing any of the assumptions can lead to population fitness being maximized when cheats are absent, which we experimentally demonstrate. These three conditions will often be relevant, and hence in order to understand the trajectory of social interactions, understanding the dynamics of the efficiency of resource utilization and accuracy of information will be necessary.

Benchmarking heterogeneous electrocatalysts for the oxygen evolution reaction.

Science.gov (United States)

McCrory, Charles C L; Jung, Suho; Peters, Jonas C; Jaramillo, Thomas F

2013-11-13

Objective evaluation of the activity of electrocatalysts for water oxidation is of fundamental importance for the development of promising energy conversion technologies including integrated solar water-splitting devices, water electrolyzers, and Li-air batteries. However, current methods employed to evaluate oxygen-evolving catalysts are not standardized, making it difficult to compare the activity and stability of these materials. We report a protocol for evaluating the activity, stability, and Faradaic efficiency of electrodeposited oxygen-evolving electrocatalysts. In particular, we focus on methods for determining electrochemically active surface area and measuring electrocatalytic activity and stability under conditions relevant to an integrated solar water-splitting device. Our primary figure of merit is the overpotential required to achieve a current density of 10 mA cm(-2) per geometric area, approximately the current density expected for a 10% efficient solar-to-fuels conversion device. Utilizing the aforementioned surface area measurements, one can determine electrocatalyst turnover frequencies. The reported protocol was used to examine the oxygen-evolution activity of the following systems in acidic and alkaline solutions: CoO(x), CoPi, CoFeO(x), NiO(x), NiCeO(x), NiCoO(x), NiCuO(x), NiFeO(x), and NiLaO(x). The oxygen-evolving activity of an electrodeposited IrO(x) catalyst was also investigated for comparison. Two general observations are made from comparing the catalytic performance of the OER catalysts investigated: (1) in alkaline solution, every non-noble metal system achieved 10 mA cm(-2) current densities at similar operating overpotentials between 0.35 and 0.43 V, and (2) every system but IrO(x) was unstable under oxidative conditions in acidic solutions.

Human-Capital based Governance Structure, Success Factors and Barriers to Effective Governance: Co-operatives in Malaysia

Directory of Open Access Journals (Sweden)

Rohana Othman

2016-01-01

Full Text Available Co-operatives comprise the crucial third engine of growth for the Malaysian economy after the public and private sectors. This study investigates the human capital based governance structure, success factors and barriers to effective governance of co-operatives in Malaysia. Questionnaires were distributed to the top 100 co-operatives listed in the Malaysian Co-operative Societies Commission website. Analysis of the responses to the questionnaires showed that human capital based co-operatives governance comprise members’ participation, independence of the board, depth of expertise and competencies of directors and other characteristics of the board. This study also identified branding as the most important success factor ahead of competitiveness and proximity. Malaysia’s economy is projected to continue relying significantly on the performance of co-operatives. Thus, it is incumbent for greater attention to be given towards an effective governance that results in successful co-operatives.

Design and synthesis of biotin analogues reversibly binding with streptavidin.

Science.gov (United States)

Yamamoto, Tomohiro; Aoki, Kiyoshi; Sugiyama, Akira; Doi, Hirofumi; Kodama, Tatsuhiko; Shimizu, Yohei; Kanai, Motomu

2015-04-01

Two new biotin analogues, biotin carbonate 5 and biotin carbamate 6, have been synthesized. These molecules were designed to reversibly bind with streptavidin by replacing the hydrogen-bond donor NH group(s) of biotin's cyclic urea moiety with oxygen. Biotin carbonate 5 was synthesized from L-arabinose (7), which furnishes the desired stereochemistry at the 3,4-cis-dihydroxy groups, in 11% overall yield (over 10 steps). Synthesis of biotin carbamate 6 was accomplished from L-cysteine-derived chiral aldehyde 33 in 11% overall yield (over 7 steps). Surface plasmon resonance analysis of water-soluble biotin carbonate analogue 46 and biotin carbamate analogue 47 revealed that KD values of these compounds for binding to streptavidin were 6.7×10(-6)  M and 1.7×10(-10)  M, respectively. These values were remarkably greater than that of biotin (KD =10(-15)  M), and thus indicate the importance of the nitrogen atoms for the strong binding between biotin and streptavidin. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mitochondrial Respiration and Oxygen Tension.

Science.gov (United States)

Shaw, Daniel S; Meitha, Karlia; Considine, Michael J; Foyer, Christine H

2017-01-01

Measurements of respiration and oxygen tension in plant organs allow a precise understanding of mitochondrial capacity and function within the context of cellular oxygen metabolism. Here we describe methods that can be routinely used for the isolation of intact mitochondria, and the determination of respiratory electron transport, together with techniques for in vivo determination of oxygen tension and measurement of respiration by both CO 2 production and O 2 consumption that enables calculation of the respiratory quotient [CO 2 ]/[O 2 ].

Crystal structure and surface characteristics of Sr-doped GdBaCo2O6−δ double perovskites: oxygen evolution reaction and conductivity

KAUST Repository

Pramana, Stevin S.

2017-12-04

A cheap and direct solution towards engineering better catalysts through identification of novel materials is required for a sustainable energy system. Perovskite oxides have emerged as potential candidates to replace the less economically attractive Pt and IrO2 water splitting catalysts. In this work, excellent electrical conductivity (980 S cm−1) was found for the double perovskite of composition GdBa0.6Sr0.4Co2O6−δ which is consistent with a better oxygen evolution reaction activity with the onset polarisation of 1.51 V with respect to a reversible hydrogen electrode (RHE). GdBa1−xSrxCo2O6−δ with increasing Sr content was found to crystallise in the higher symmetry tetragonal P4/mmm space group in comparison with the undoped GdBaCo2O6−δ which is orthorhombic (Pmmm), and yields higher oxygen uptake, accompanied by higher Co oxidation states. This outstanding electrochemical performance is explained by the wider carrier bandwidth, which is a function of Co–O–Co buckling angles and Co–O bond lengths. Furthermore the higher oxygen evolution activity was observed despite the formation of non-lattice oxides (mainly hydroxide species) and enrichment of alkaline earth ions on the surface.

Crystal structure and surface characteristics of Sr-doped GdBaCo2O6−δ double perovskites: oxygen evolution reaction and conductivity

KAUST Repository

Pramana, Stevin S.; Cavallaro, Andrea; Li, Cheng; Handoko, Albertus D.; Chan, Kuang Wen; Walker, Robert J.; Regoutz, Anna; Herrin, Jason S.; Yeo, Boon Siang; Payne, David J.; Kilner, John A.; Ryan, Mary P.; Skinner, Stephen J.

2017-01-01

A cheap and direct solution towards engineering better catalysts through identification of novel materials is required for a sustainable energy system. Perovskite oxides have emerged as potential candidates to replace the less economically attractive Pt and IrO2 water splitting catalysts. In this work, excellent electrical conductivity (980 S cm−1) was found for the double perovskite of composition GdBa0.6Sr0.4Co2O6−δ which is consistent with a better oxygen evolution reaction activity with the onset polarisation of 1.51 V with respect to a reversible hydrogen electrode (RHE). GdBa1−xSrxCo2O6−δ with increasing Sr content was found to crystallise in the higher symmetry tetragonal P4/mmm space group in comparison with the undoped GdBaCo2O6−δ which is orthorhombic (Pmmm), and yields higher oxygen uptake, accompanied by higher Co oxidation states. This outstanding electrochemical performance is explained by the wider carrier bandwidth, which is a function of Co–O–Co buckling angles and Co–O bond lengths. Furthermore the higher oxygen evolution activity was observed despite the formation of non-lattice oxides (mainly hydroxide species) and enrichment of alkaline earth ions on the surface.

International co-operation for reactor safety: the World Association of Nuclear Operators

International Nuclear Information System (INIS)

Eckered, T.

1989-01-01

On 5 and 6 October 1987, senior representatives of most of the world's nuclear operators met in Paris with Lord Marshall of the UK Central Electricity Generating Board (CEGB) as Chairman. They resolved to strengthen the existing links and co-operation among nuclear operators by setting up the World Association of Nuclear Operators (Wano). The mission of the association is to be: 'to maximize the safety and reliability of the operation of nuclear power stations by exchanging information, encouraging comparison and stimulating emulation among nuclear power station operators.' The formation of Wano presents some information technology problems of a rather special kind that have to be solved before Wano can begin operation. The representatives at the Paris meeting therefore appointed a steering committee under Lord Marshall's chairmanship to formulate detailed proposals. The leaders of the world's nuclear operators will meet again in Moscow on 15-17 May 1989 in order to ratify the steering committee proposals and appoint the first Wano Board of Governors. A small interim secretariat is already working in London. (author)

Alterations of serum concentrations of thyroid hormones and sex hormone-binding globulin, nuclear binding of tri-iodothyronine and thyroid hormone-stimulated cellular uptake of oxygen and glucose in mononuclear blood cells from patients with non-thyroidal illness

DEFF Research Database (Denmark)

Kvetny, J; Matzen, L

1990-01-01

Nuclear tri-iodothyronine (T3) binding and thyroid hormone-stimulated oxygen consumption and glucose uptake were examined in mononuclear blood cells from patients with non-thyroidal illness (NTI) in which serum T3 was significantly (P less than 0.05) depressed (0.62 +/- 0.12 (S.D.) nmol/l) compared...

Elementary steps of the catalytic oxidation of CO in a gas phase in the presence of rhenium cations with carbonyl and oxygen ligands: a comparison with heterogeneous catalysis

International Nuclear Information System (INIS)

Goncharov, V.B.; Fialko, E.F.; Shejnin, D.Eh.; Kikhtenko, A.V.

1997-01-01

Reactivity in a gaseous phase o rhenium (Re + ) and rhenium monocarbonyl (ReCO + ) in the reaction of CO oxidation in oxygen-containing reagents (NO, O 2 , H 2 O) is studied through the method of the ionic cyclotron resonance. It is shown that presence of carbonyl ligand essentially influences the ion reactivity. The effective channel of the metal monocarbonyl ions oxidation through molecular oxygen is found. Accounting for this stage makes of possible to explain the low-temperature activity of a number of oxide catalyzer Mo, W in the reaction of CO oxidation by molecular oxygen

CO self-shielding as the origin of oxygen isotope anomalies in the early solar nebula.

Science.gov (United States)

Lyons, J R; Young, E D

2005-05-19

The abundances of oxygen isotopes in the most refractory mineral phases (calcium-aluminium-rich inclusions, CAIs) in meteorites have hitherto defied explanation. Most processes fractionate isotopes by nuclear mass; that is, 18O is twice as fractionated as 17O, relative to 16O. In CAIs 17O and 18O are nearly equally fractionated, implying a fundamentally different mechanism. The CAI data were originally interpreted as evidence for supernova input of pure 16O into the solar nebula, but the lack of a similar isotope trend in other elements argues against this explanation. A symmetry-dependent fractionation mechanism may have occurred in the inner solar nebula, but experimental evidence is lacking. Isotope-selective photodissociation of CO in the innermost solar nebula might explain the CAI data, but the high temperatures in this region would have rapidly erased the signature. Here we report time-dependent calculations of CO photodissociation in the cooler surface region of a turbulent nebula. If the surface were irradiated by a far-ultraviolet flux approximately 10(3) times that of the local interstellar medium (for example, owing to an O or B star within approximately 1 pc of the protosun), then substantial fractionation of the oxygen isotopes was possible on a timescale of approximately 10(5) years. We predict that similarly irradiated protoplanetary disks will have H2O enriched in 17O and 18O by several tens of per cent relative to CO.

Kinetic and spectroscopic investigation of CoII, NiII, and N-oxalylglycine inhibition of the FeII/α-ketoglutarate dioxygenase, TauD

International Nuclear Information System (INIS)

Kalliri, Efthalia; Grzyska, Piotr K.; Hausinger, Robert P.

2005-01-01

Co II , Ni II , and N-oxalylglycine (NOG) are well-known inhibitors of Fe II /α-ketoglutarate (αKG)-dependent hydroxylases, but few studies describe their kinetics and no spectroscopic investigations have been reported. Using taurine/αKG dioxygenase (TauD) as a paradigm for this enzyme family, time-dependent inhibition assays showed that Co II and Ni II follow slow-binding inhibition kinetics. Whereas Ni II -substituted TauD was non-chromophoric, spectroscopic studies of the Co II -substituted enzyme revealed a six-coordinate site (protein alone or with αKG) that became five-coordinate upon taurine addition. The Co II spectrum was not perturbed by a series of anions or oxidants, suggesting the Co II is inaccessible and could be used to stabilize the protein. NOG competed weakly (K i ∼ 290 μM) with αKG for binding to TauD, with the increased electron density of NOG yielding electronic transitions for NOG-Fe II -TauD and taurine-NOG-Fe II -TauD at 380 nm (ε 38 90-105 M -1 cm -1 ). The spectra of the NOG-bound TauD species did not change significantly upon oxygen exposure, arguing against the formation of an oxygen-bound state mimicking an early intermediate in catalysis

Simultaneous Blood–Tissue Exchange of Oxygen, Carbon Dioxide, Bicarbonate, and Hydrogen Ion

Science.gov (United States)

Dash, Ranjan K.; Bassingthwaighte, James B.

2014-01-01

A detailed nonlinear four-region (red blood cell, plasma, interstitial fluid, and parenchymal cell) axially distributed convection-diffusion-permeation-reaction-binding computational model is developed to study the simultaneous transport and exchange of oxygen (O2) and carbon dioxide (CO2) in the blood–tissue exchange system of the heart. Since the pH variation in blood and tissue influences the transport and exchange of O2 and CO2 (Bohr and Haldane effects), and since most CO2 is transported as HCO3- (bicarbonate) via the CO2 hydration (buffering) reaction, the transport and exchange of HCO3- and H+ are also simulated along with that of O2 and CO2. Furthermore, the model accounts for the competitive nonlinear binding of O2 and CO2 with the hemoglobin inside the red blood cells (nonlinear O2–CO2 interactions, Bohr and Haldane effects), and myoglobin-facilitated transport of O2 inside the parenchymal cells. The consumption of O2 through cytochrome-c oxidase reaction inside the parenchymal cells is based on Michaelis–Menten kinetics. The corresponding production of CO2 is determined by respiratory quotient (RQ), depending on the relative consumption of carbohydrate, protein, and fat. The model gives a physiologically realistic description of O2 transport and metabolism in the microcirculation of the heart. Furthermore, because model solutions for tracer transients and steady states can be computed highly efficiently, this model may be the preferred vehicle for routine data analysis where repetitive solutions and parameter optimization are required, as is the case in PET imaging for estimating myocardial O2 consumption. PMID:16775761

CO Emissions from Gas Engines Operating on Biomass Producer Gas

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Jensen, T. K.; Henriksen, Ulrik Birk

2004-01-01

High carbon monoxide (CO) emission from gas engines fueled by producer gas is a concerning problem in the struggle to make biomass gasification for heat and power production a success. CO emissions from engines operating on biomass producer gases are high, especially at very lean conditions where...

Oxygenated palm biodiesel: Ignition, combustion and emissions quantification in a light-duty diesel engine

International Nuclear Information System (INIS)

Chong, Cheng Tung; Ng, Jo-Han; Ahmad, Solehin; Rajoo, Srithar

2015-01-01

Highlights: • Diesel engine test using palm biodiesel and diesel at varying speed and load. • Palm biodiesel shows better performance at late stage of cycle evolution. • Oxygen in palm biodiesel fuel improves local combustion at late stage of combustion. • Emissions of NO are lower at low and medium operating speed for palm biodiesel. • Formulation of trend guide for performance and emissions characteristics for light-duty diesel engines. - Abstract: This paper presents an investigation of oxygenated neat palm biodiesel in a direct injection single cylinder diesel engine in terms of ignition, combustion and emissions characteristics. Conventional non-oxygenated diesel fuel is compared as baseline. The engine testing is performed between the operating speed of 2000–3000 rpm and load of up to 3 bar of brake mean effective pressure. From it, a total of 50 experiment cases are tested to form a comprehensive operational speed-load contour map for ignition and combustion; while various engine-out emissions such as NO, CO, UHCs and CO 2 are compared based on fuel type-speed combinations. The ignition and combustion evolution contour maps quantify the absolute ignition delay period and elucidate the difference between that of palm biodiesel and fossil diesel. Although diesel has shorter ignition delay period by up to 0.6 CAD at 3000 rpm and burns more rapidly at the start of combustion, combustion of palm biodiesel accelerates during the mid-combustion phase and overtakes diesel in the cumulative heat release rates (HRR) prior to the 90% cumulative HRR. This can be attributed to the oxygen contained in palm biodiesel assisting in localized regions of combustion. In terms of performance, the oxygenated nature of palm biodiesel provided mixed performances with improved thermal efficiency and increased brake specific fuel consumption, due to the improved combustion and lower calorific values, respectively. Emission measurements show that NO for palm biodiesel is

Atomic-Level Co3O4 Layer Stabilized by Metallic Cobalt Nanoparticles: A Highly Active and Stable Electrocatalyst for Oxygen Reduction.

Science.gov (United States)

Liu, Min; Liu, Jingjun; Li, Zhilin; Wang, Feng

2018-02-28

Developing atomic-level transition oxides may be one of the most promising ways for providing ultrahigh electrocatalytic performance for oxygen reduction reaction (ORR), compared with their bulk counterparts. In this article, we developed a set of atomically thick Co 3 O 4 layers covered on Co nanoparticles through partial reduction of Co 3 O 4 nanoparticles using melamine as a reductive additive at an elevated temperature. Compared with the original Co 3 O 4 nanoparticles, the synthesized Co 3 O 4 with a thickness of 1.1 nm exhibits remarkably enhanced ORR activity and durability, which are even higher than those obtained by a commercial Pt/C in an alkaline environment. The superior activity can be attributed to the unique physical and chemical structures of the atomic-level oxide featuring the narrowed band gap and decreased work function, caused by the escaped lattice oxygen and the enriched coordination-unsaturated Co 2+ in this atomic layer. Besides, the outstanding durability of the catalyst can result from the chemically epitaxial deposition of the Co 3 O 4 on the cobalt surface. Therefore, the proposed synthetic strategy may offer a smart way to develop other atomic-level transition metals with high electrocatalytic activity and stability for energy conversion and storage devices.

Germanium diffusion with vapor-phase GeAs and oxygen co-incorporation in GaAs

Science.gov (United States)

Wang, Wei-Fu; Cheng, Kai-Yuan; Hsieh, Kuang-Chien

2018-01-01

Vapor-phase germanium diffusion has been demonstrated in Zn-doped and semi-insulating GaAs in sealed ampoules with GeAs powders and excess arsenic. Secondary-ion-mass spectroscopy (SIMS) profiles indicate the presence of unintentional co-incorporation of oxygen in high densities (>1017/cm3) along with diffused germanium donors whose concentration (>>1018/cm3) determined by electro-chemical capacitance-voltage (ECV) profiler shows significant compensation near the surface. The source of oxygen mainly originates from the GeAs powder which contains Ge-O surface oxides. Variable-temperature photoluminescence (PL) shows that in GeAs-diffused samples, a broad peak ranging from 0.86-1.38 eV with the peak position around 1.1 eV predominates at low temperatures while the near band-edge luminescence quenches. The broad band is attributed to the GeGa-VGa self-activated (SA) centers possibly associated with nearby oxygen-related defect complex, and its luminescence persists up to 400 K. The configurational-coordinate modeling finds that the SA defect complex has a thermal activation energy of 150-180 meV and a vibrational energy 26.8 meV. The presence of oxygen does not much affect the SA emission intensity but may have influenced the peak position, vibration frequency and activation energy as compared to other common donor-VGa defects in GaAs.

Germanium diffusion with vapor-phase GeAs and oxygen co-incorporation in GaAs

Directory of Open Access Journals (Sweden)

Wei-Fu Wang

2018-01-01

Full Text Available Vapor-phase germanium diffusion has been demonstrated in Zn-doped and semi-insulating GaAs in sealed ampoules with GeAs powders and excess arsenic. Secondary-ion-mass spectroscopy (SIMS profiles indicate the presence of unintentional co-incorporation of oxygen in high densities (>1017/cm3 along with diffused germanium donors whose concentration (>>1018/cm3 determined by electro-chemical capacitance-voltage (ECV profiler shows significant compensation near the surface. The source of oxygen mainly originates from the GeAs powder which contains Ge-O surface oxides. Variable-temperature photoluminescence (PL shows that in GeAs-diffused samples, a broad peak ranging from 0.86-1.38 eV with the peak position around 1.1 eV predominates at low temperatures while the near band-edge luminescence quenches. The broad band is attributed to the GeGa-VGa self-activated (SA centers possibly associated with nearby oxygen-related defect complex, and its luminescence persists up to 400 K. The configurational-coordinate modeling finds that the SA defect complex has a thermal activation energy of 150-180 meV and a vibrational energy 26.8 meV. The presence of oxygen does not much affect the SA emission intensity but may have influenced the peak position, vibration frequency and activation energy as compared to other common donor-VGa defects in GaAs.

Ultrafast atomic layer-by-layer oxygen vacancy-exchange diffusion in double-perovskite LnBaCo2O5.5+δ thin films.

Science.gov (United States)

Bao, Shanyong; Ma, Chunrui; Chen, Garry; Xu, Xing; Enriquez, Erik; Chen, Chonglin; Zhang, Yamei; Bettis, Jerry L; Whangbo, Myung-Hwan; Dong, Chuang; Zhang, Qingyu

2014-04-22

Surface exchange and oxygen vacancy diffusion dynamics were studied in double-perovskites LnBaCo2O5.5+δ (LnBCO) single-crystalline thin films (Ln = Er, Pr; -0.5 atoms in the LnBCO thin films is taking the layer by layer oxygen-vacancy-exchange mechanism. The first principles density functional theory calculations indicate that hydrogen atoms are present in LnBCO as bound to oxygen forming O-H bonds. This unprecedented oscillation phenomenon provides the first direct experimental evidence of the layer by layer oxygen vacancy exchange diffusion mechanism.

In situ characterization of cofacial Co(IV) centers in Co4O4 cubane: Modeling the high-valent active site in oxygen-evolving catalysts.

Science.gov (United States)

Brodsky, Casey N; Hadt, Ryan G; Hayes, Dugan; Reinhart, Benjamin J; Li, Nancy; Chen, Lin X; Nocera, Daniel G

2017-04-11

The Co 4 O 4 cubane is a representative structural model of oxidic cobalt oxygen-evolving catalysts (Co-OECs). The Co-OECs are active when residing at two oxidation levels above an all-Co(III) resting state. This doubly oxidized Co(IV) 2 state may be captured in a Co(III) 2 (IV) 2 cubane. We demonstrate that the Co(III) 2 (IV) 2 cubane may be electrochemically generated and the electronic properties of this unique high-valent state may be probed by in situ spectroscopy. Intervalence charge-transfer (IVCT) bands in the near-IR are observed for the Co(III) 2 (IV) 2 cubane, and spectroscopic analysis together with electrochemical kinetics measurements reveal a larger reorganization energy and a smaller electron transfer rate constant for the doubly versus singly oxidized cubane. Spectroelectrochemical X-ray absorption data further reveal systematic spectral changes with successive oxidations from the cubane resting state. Electronic structure calculations correlated to experimental data suggest that this state is best represented as a localized, antiferromagnetically coupled Co(IV) 2 dimer. The exchange coupling in the cofacial Co(IV) 2 site allows for parallels to be drawn between the electronic structure of the Co 4 O 4 cubane model system and the high-valent active site of the Co-OEC, with specific emphasis on the manifestation of a doubly oxidized Co(IV) 2 center on O-O bond formation.

The co-operative model as a means of stakeholder management: An exploratory qualitative analysis

Directory of Open Access Journals (Sweden)

Darrell Hammond

2016-11-01

Full Text Available The South African economy has for some time been characterised by high unemployment, income inequality and a skills mismatch, all of which have contributed to conflict between business, government and labour. The co-operative model of stakeholder management is examined as a possible mitigating organisational form in this high-conflict environment. International experience indicates some success with co-operative models but they are not easy to implement effectively and face severe obstacles. Trust and knowledge sharing are critical for enabling a co-operative model of stakeholder management, which requires strong governance and adherence to strict rules. The model must balance the tension between optimisation of governance structures and responsiveness to members' needs. Furthermore, support from social and political institutions is necessary. We find barriers to scalability which manifest in the lack of depth of business skills, negative perception of the co-operative model by external stakeholders, government ambivalence, and a lack of willingness on the part of workers to co-operate for mutual benefit.

Impact of oxygenation on the performance of three non-Saccharomyces yeasts in co-fermentation with Saccharomyces cerevisiae.

Science.gov (United States)

Shekhawat, Kirti; Bauer, Florian F; Setati, Mathabatha E

2017-03-01

The sequential or co-inoculation of grape must with non-Saccharomyces yeast species and Saccharomyces cerevisiae wine yeast strains has recently become a common practice in winemaking. The procedure intends to enhance unique aroma and flavor profiles of wine. The extent of the impact of non-Saccharomyces strains depends on their ability to produce biomass and to remain metabolically active for a sufficiently long period. However, mixed-culture wine fermentations tend to become rapidly dominated by S. cerevisiae, reducing or eliminating the non-Saccharomyces yeast contribution. For an efficient application of these yeasts, it is therefore essential to understand the environmental factors that modulate the population dynamics of such ecosystems. Several environmental parameters have been shown to influence population dynamics, but their specific effect remains largely uncharacterized. In this study, the population dynamics in co-fermentations of S. cerevisiae and three non-Saccharomyces yeast species: Torulaspora delbrueckii, Lachancea thermotolerans, and Metschnikowia pulcherrima, was investigated as a function of oxygen availability. In all cases, oxygen availability strongly influenced population dynamics, but clear species-dependent differences were observed. Our data show that L. thermotolerans required the least oxygen, followed by T. delbrueckii and M. pulcherrima. Distinct species-specific chemical volatile profiles correlated in all cases with increased persistence of non-Saccharomyces yeasts, in particular increases in some higher alcohols and medium chain fatty acids. The results highlight the role of oxygen in regulating the succession of yeasts during wine fermentations and suggests that more stringent aeration strategies would be necessary to support the persistence of non-Saccharomyces yeasts in real must fermentations.

Effect of 60Co-gamma radiation on the binding properties in furs

International Nuclear Information System (INIS)

Raina, R.K.

1992-01-01

New Zealand white rabbit pelts were pickled by the usual procedure and were tanned with basic aluminium sulphate, basic chromium sulphate and their combinations. Tanned furs were irradiated with 60 Co-gamma radiations in the dose range of 5.0-114.0 kGy. The effect of radiation on the binding properties of various added substances like mineral tannins, fats, moisture and shrinkage temperature has been assessed by their comparison with the control samples. The results of these investigations show that radiation on furs causes detannage, increases the moisture and bound fat content and decreases the shrinkage temperature of the furs. (author)

SUBTASK 2.19 – OPERATIONAL FLEXIBILITY OF CO2 TRANSPORT AND STORAGE

Energy Technology Data Exchange (ETDEWEB)

Jensen, Melanie; Schlasner, Steven; Sorensen, James; Hamling, John

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 and 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

Oxygen diffusion in bilayer polymer films

DEFF Research Database (Denmark)

Poulsen, Lars; Zebger, Ingo; Tofte, Jannik Pentti

2004-01-01

Experiments to quantify oxygen diffusion have been performed on polymer samples in which a film of poly(ethylene-co-norbornene) was cast onto a film of polystyrene which, in turn, was cast onto an oxygen-impermeable substrate. In the technique employed, the time evolution of oxygen transport...... through the film of poly(ethylene-co-norbornene) and into the polystyrene film was monitored using the phosphorescence of singlet oxygen as a spectroscopic probe. To analyze the data, it was necessary to solve Fick's second law of diffusion for both polymer films. Tractable analytical and numerical...

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3-δ

NARCIS (Netherlands)

Berenov, A.; Atkinson, A.; Kilner, J.; Ananyev, M.; Eremin, V.; Porotnikova, N.; Farlenkov, A.; Kurumchin, E.; Bouwmeester, Henricus J.M.; Bucher, E.; Sitte, W.

2014-01-01

The oxygen tracer diffusion coefficient, Db⁎, and the oxygen tracer surface exchange coefficient, k, were measured in Ba0.5Sr0.5Co0.8Fe0.2O3 − δ (BSCF5582) over the temperature range of 310–800 °C and the oxygen partial pressure range of 1.3 × 10−3–0.21 bar. Several measurement techniques were used:

Plasma Methane Pyrolysis for Spacecraft Oxygen Loop Closure

Science.gov (United States)

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.

Compound effect of CaCO3 and CaSO4·2H2O on the strength of steel slag: cement binding materials

International Nuclear Information System (INIS)

Qi, Liqian; Liu, Jiaxiang; Liu, Qian

2016-01-01

In this study, we replaced 30% of the cement with steel slag to prepare binding material; additionally, small amounts of CaCO 3 and CaSO 4 ·2H 2 O were added. This was done to study the compound effect of CaCO 3 and CaSO 4 ·2H 2 O on the strength of steel slag-cement binding materials. The hydration degree of the steel slag cementitious material was analyzed by XRD, TG and SEM. The results showed that the optimum proportions of CaCO 3 and CaSO 4 ·2H 2 O were 3% and 2%, respectively. Compared with the steel slag-cement binders without adding CaCO 3 and CaSO 4 ·2H 2 O, the compressive strength increased by 59.9% at 3 days and by 17.8% at 28 days. Acting as the nucleation matrix, CaCO 3 could accelerate the hydration of C 3 S. In addition, CaCO 3 was involved in the hydration reaction, generating a new hydration product, which could stably exist in a slurry. Meanwhile, CaSO 4 ·2H 2 O could increase the number of AFt. The compound effect of CaCO 3 and CaSO 4 ·2H 2 O enhanced the intensity of steel slag-cement binding materials and improved the whole hydration behavior. (author)

One-step preparation of N-doped graphene/Co nanocomposite as an advanced oxygen reduction electrocatalyst

International Nuclear Information System (INIS)

Bai, Fo; Huang, Hao; Tan, Yanlei; Hou, Changmin; Zhang, Ping

2015-01-01

Graphical abstract: N-doped graphene/Co nanocomposites were synthesized through one-step pyrolysis process and the product exhibits high performance for ORR and excellent stability in alkaline medium. - Highlights: • N-doped graphene/Co nano-composite is directly synthesized by a one-step method from Co(NO3)2∙6H2O, glucose and dicyandiamide (DCDA). • The electrocatalytic performance of as-prepared NG/Co-0.5 shows the peak potential positively shifts about 10 mV than commercial Pt/C electrode. • The material shows an excellent stability and tolerance to methanol poisoning effects in alkaline medium. - Abstract: N-doped graphene/Co nanocomposites (NG/Co NPs) have been prepared by a simple one-step pyrolysis of Co(NO 3 ) 2 ∙6H 2 O, glucose and dicyandiamide (DCDA). The products with nitrogen doped and suitable graphitic degree perform high electrocatalytic activity (with the reduction peak at −0.099 V vs Ag/AgCl) and near four-electron selectivity for the oxygen reduction reaction (ORR), with excellent stability and durability in alkaline medium comparable to a commercial Pt/C catalyst. Owing to the superb ORR performance, low cost and facile preparation, the catalysts of NG/Co NPs have great potential applications in fuel cells, metal-air batteries and ORR-related electrochemical industries

Synthesis and oxygen vacancy related NO{sub 2} gas sensing properties of ZnO:Co nanorods arrays gown by a hydrothermal method

Energy Technology Data Exchange (ETDEWEB)

Zou, Changwei, E-mail: qingyihaiyanas@163.com; Liang, Feng; Xue, Shuwen

2015-10-30

Highlights: • Co doped ZnO:Co nanorods were grown by hydrothermal method. • The NO{sub 2} response reaches a maximum value of 88 at 210 °C. • The stability of NO{sub 2} on ZnO is enhanced with the presence of V{sub O}. - Abstract: Highly ordered Co doped ZnO:Co nanorods arrays with Co concentrations of 1.6, 1.9 and 3.1 at% were uniformly grown on FTO glass substrate by hydrothermal method. The X-ray diffraction patterns of the undoped and Co doped ZnO nanorods revealed characteristic peaks of (1 0 0), (0 0 2), (1 0 1), (1 0 3) and (1 1 2), corresponding to the hexagonal wurtzite phase of ZnO. For ZnO:Co nanorods with Co concentrations of 3.1 at%, the NO{sub 2} response reached a maximum value of 88 at temperature of 210 °C. However, the response of ZnO:Co nanorods with Co concentrations of 3.1 at% decreased from 82 to 29 with the increasing of O{sub 2} annealing temperature from 0 to 700 °C. As confirmed by the XPS, PL, Raman and I–V results, the oxygen vacancies and electron concentrations were the dominating effects and an oxygen vacancy mediated NO{sub 2} sensing mechanism was presented and discussed.

Carbon and oxygen isotope analysis of leaf biomass reveals contrasting photosynthetic responses to elevated CO2 near geologic vents in Yellowstone National Park

Directory of Open Access Journals (Sweden)

D. G. Williams

2009-01-01

Full Text Available In this study we explore the use of natural CO2 emissions in Yellowstone National Park (YNP in Wyoming, USA to study responses of natural vegetation to elevated CO2 levels. Radiocarbon (14C analysis of leaf biomass from a conifer (Pinus contortus; lodgepole pine and an invasive, non-native herb (Linaria dalmatica; Dalmation toadflax was used to trace the inputs of vent CO2 and quantify assimilation-weighted CO2 concentrations experienced by individual plants near vents and in comparable locations with no geologic CO2 exposure. The carbon and oxygen isotopic composition and nitrogen percent of leaf biomass from the same plants was used to investigate photosynthetic responses of these plants to naturally elevated atmospheric CO2 concentrations. The coupled shifts in carbon and oxygen isotope values suggest that dalmation toadflax responded to elevated CO2 exposure by increasing stomatal conductance with no change in photosynthetic capacity and lodgepole pine apparently responded by decreasing stomatal conductance and photosynthetic capacity. Lodgepole pine saplings exposed to elevated levels of CO2 likewise had reduced leaf nitrogen concentrations compared to plants with no enhanced CO2 exposure, further suggesting widespread and dominant conifer down-regulated photosynthetic capacity under elevated CO2 levels near geologic vents.

An Effect of the Co-Operative Network Model for Students' Quality in Thai Primary Schools

Science.gov (United States)

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.…

Quality assurance and the sub-contract interface: co-operative evaluation

International Nuclear Information System (INIS)

Churchill, G.F.; Rippon, D.J.

1977-01-01

The CEGB standard QA 42-1 quality assurance programme requires purchasers to establish supplier selection and assessment procedures either by previous continuous record of supplying identical or equivalent material satisfactorily, or by an evaluation of the sub-contractors quality system. In order to avoid the multiple evaluations that the latter would involve for projects such as nuclear power stations, which concern a hierarchy of organisations, the idea of co-operative evaluations was suggested. The requirements involved in establishing co-operative evaluations are discussed. Some potential difficulties which have been identified from experience are described. (U.K.)

Design of a mixed ionic/electronic conducting oxygen transport membrane pilot module

Energy Technology Data Exchange (ETDEWEB)

Pfaff, E.M.; Kaletsch, A.; Broeckmann, C. [RWTH Aachen University, IWM, Aachen (Germany)

2012-03-15

In the last years, a lot of ceramic materials were developed that, at higher temperatures, have a high electrical conductivity and a high conductivity of oxygen ions. Such mixed ionic/electronic conductors can be used to produce high-purity oxygen. This work focuses on the realization of a pilot membrane module, with BSCF (Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}}) perovskite selected as the membrane material. An amount of 500 kg of powder was industrially fabricated, spray-granulized and pressed into tubes. The best operation conditions concerning energy consumption were calculated, and a module reactor was designed operating at 850 C, with an air pressure of 15-20 bar on the feed site and a low vacuum of about 0.8 bar on the permeate site. Special emphasis was placed on joining alternatives for ceramic tubes in metallic bottoms. A first laboratory module was tested with a membrane area of 1 m{sup 2} and then advanced to a pilot module with 570 tubes and a capability of more than 300 000 L of pure oxygen per day. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)