Workshop on capture and sequestration of CO{sub 2} (CCS); Taller sobre captura y secuestro de CO{sub 2} (CCS)

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-15

In this workshop diverse communications related to the capture and sequestration of CO{sub 2} are presented. This workshop was realized in the Technological Museum of the Comision Federal de Electricidad (CFE), in Mexico City on the ninth and tenth of July, 2008, and it had the objective of reflecting the necessity of considering in Mexico the application of the capture and sequestration technologies of CO{sub 2} (CCS), as well as to put in touch the technicians and managers of the Mexican institutions with the world-wide leaders in these technologies and with the managers of companies that are successfully applying CCS technologies. [Spanish] En este taller se presentan diversas ponencias relacionadas con la captura y secuestro de CO{sub 2}. Este taller se realizo en el Museo Tecnologico de la Comision Federal de Electricidad (CFE), en la Ciudad de Mexico, los dias 9 y 10 de julio de 2008 y tuvo como objetivo reflexionar sobre la necesidad de considerar en Mexico, la aplicacion de las tecnologias de captura y secuestro de CO{sub 2} (CCS), asi como poner en contacto a los tecnicos y directivos de las instituciones mexicanas con los lideres mundiales en estas tecnologias y con los directivos de empresas que estan aplicando con exito tecnologias de CCS.

Bioequivalencia de una formulación cubana de carbamazepina con el producto líder

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Alejandro Saúl Padrón Yaquis

2009-04-01

Full Text Available Se demostró la intercambiabilidad terapéutica mediante un estudio de bioequivalencia en 25 voluntarios sanos de una formulación cubana de carbamazepina de 200 mg con respecto al producto innovador (Tegretol®, en condiciones de administración a dosis única; el diseño experimental fue cruzado a doble ciegas y aleatorizado; el periodo de lavado fue de 15 días. Las extracciones para la obtención del plasma, se realizaron a las 0; 0,5; 1; 1,5; 2; 3; 4; 6; 8; 10; 12; 16; 20; 24; 48; 72; 96 y 120 h. Para el análisis se empleó un método analítico por cromatografía líquida de alta eficiencia, isocrático en fase reversa con detección ultravioleta. Se estimaron mediante técnicas "no compartimentales" los parámetros farmacocinéticos (AUC0-t, AUCt-¥, Cmax, Tmax y T1/2 representativos de la biodisponibilidad en magnitud y velocidad. Sobre la base de los resultados estadísticos, ambas formulaciones resultaron bioequivalentes.

REDUCCIÓN DE ÓXIDOSDE NITROGENO CON CATALIZADORES ZEOLÍTICOS INTERCAMBIADOS CON COBALTO

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Enrique Alexis García Moya

2012-10-01

Full Text Available Se presenta un estudio sobre la reducción catalítica selectiva (RCS de NOx con metano en presencia de oxígeno en exceso con varios catalizadores a base de las zeolitas mordenita, ferrierita y ZSM-5 intercambiadas con diferentes cargas de cobalto y con las correspondientes zeolitas en forma acida. Cuando la mezcla reactiva contenía mayormente NO2 en lugar de NO, los catalizadores ácidos mostraron las más altas velocidades de formación de N2 en condiciones secas. Las mayores actividades se obtuvieron con los catalizadores Co-mordenita, siguiendo en orden de actividad los catalizadores Co-Ferrierita y Co-ZSM-5. El catalizador Co-Mordenita más activo se ensayó con una mezcla reactiva donde predominó el NO en lugar del NO2 bajo condiciones secas e hidrotérmicas y en presencia de SO2. Con la adición de 8% de agua a la mezcla de reacción se observó desactivación reversible, especialmente a bajas temperaturas. La adición de 60 ppm de SO2 disminuyó la velocidad de reacción aproximadamente a la mitad debido posiblemente al envenenamiento de algunos sitios activos.

A Review of Staphylococcal Cassette Chromosome mec (SCCmec) Types in Coagulase-Negative Staphylococci (CoNS) Species.

Science.gov (United States)

Saber, Huda; Jasni, Azmiza Syawani; Jamaluddin, Tengku Zetty Maztura Tengku; Ibrahim, Rosni

2017-10-01

Coagulase-negative staphylococci (CoNS) are considered low pathogenic organisms. However, they are progressively causing more serious infections with time because they have adapted well to various antibiotics owing to their ability to form biofilms. Few studies have been conducted on CoNS in both, hospital and community-acquired settings, especially in Malaysia. Thus, it is important to study their species and gene distributions. A mobile genetic element, staphylococcal cassette chromosome mec (SCC mec ), plays an important role in staphylococci pathogenesis. Among CoNS, SCC mec has been studied less frequently than Staphylococcus aureus (coagulase-positive staphylococci). A recent study (8) conducted in Malaysia successfully detected SCC mec type I to VIII as well as several new combination patterns in CoNS species, particularly Staphylococcus epidermidis . However, data are still limited, and further research is warranted. This paper provides a review on SCC mec types among CoNS species.

Carbon dioxide (CO{sub 2}) digital subtraction angiography. Evaluation of a new delivery system; Angiografia con anidride carbonica. Nuovo sistema di iniezione

Energy Technology Data Exchange (ETDEWEB)

Nicolini, A.; Lovaria, A.; Meregaglia, D. [Ospedale Maggiore IRCCS Policlinico, Milan (Italy). Dipt. di Scienze Radiologiche; Palatresi, S. [Ospedale Maggiore IRCCS Policlinico, Milan (Italy). Ist. di Clinica Medica Generale e Terapia Medica

2000-02-01

Purpose of this work is to evaluate the usefulness of a new carbon dioxide (CO{sub 2}) intravascular injection system in digital subtraction angiography. March 1998 to May 1999, 39 patients were submitted to digital subtraction angiography with CO{sub 2} injection by a new delivery system, CO{sub 2}-Angio set, OptiMed, Ettingen, Germany. The patients were 29 men and 10 women, whose age ranged 32 to 76 (mean: 47), 18 of them with absolute or relative contraindications to iodinated contrast media and 6 with poor diagnostic findings at previous conventional angiography. CO{sub 2} was used for comparison with iodinated contrast agents in 4 patients. It was studied the following vascular districts: renal arteries in 9 patients, portal vein in 18, lower limb arteries in 7, upper limb veins in 4. In 1 patient CO{sub 2} angiography was carried out for the diagnosis and interventional treatment, by transcatheter embolization, of a postbioptic arteriovenous renal fistula. During the procedure, arterial blood pressure, EKG status and oxygen saturation were monitored, and subjective sensations recorded in all patients. CO{sub 2} angiography provided adequate visualization of vascular districts and of abnormal findings in 32 cased (82%), while its results were considered insufficient for correct and complete assessment in 7 cases (18%). CO{sub 2}-Angio set delivery system has proved to be a simple and safe tool, particularly suitable for use in patients at risk for allergic reactions to iodinated contrast agents and in those with renal function impairment. Also, the system can help carry out some interventional procedures such as arteriovenous fistula embolization and trans jugular portosystemic shunting. [Italian] Scopo di questo articolo e' verificare la validita' e l'efficacia di un nuovo sistema di iniezione angiografico per anidride carbonica. Da marzo 1998 a maggio 1999 sono stati sottoposti ad angiografia con anidride carbonica mediante sistema non

Structural, electronic, and mechanical properties of CoN and NiN. An ab initio study

Energy Technology Data Exchange (ETDEWEB)

Amudhavalli, A.; Manikandan, M.; Cinthia, A. Jemmy; Rajeswarapalanichamy, R. [NMSSVN College, Tamil Nadu (India). Dept. of Physics; Iyakutti, K. [SRM Univ., Tamil Nadu (India). Dept. of Physics and Nanotechnology

2017-07-01

The structural stabilities of cobalt mononitride (CoN) and nickel mono-nitride (NiN) were investigated among the crystal structures, namely, NaCl (B1), CsCl (B2), and zinc blende (B3). It was found that the zinc blende (B3) phase was the most stable phase for both nitrides. A pressure-induced structural phase transition from B3 to B1 phase was predicted in these nitrides. The computed lattice parameter values were in agreement with the experimental values and other theoretical values. The electronic structures reveal that these nitrides are metallic at zero pressure. The computed elastic constants indicate that CoN and NiN are mechanically stable in the B1 and B3 phases. The variations of the elastic constants, bulk modulus, shear modulus, Poisson's ratio, and elastic anisotropy factor with pressure were investigated. The Debye temperature θ{sub D} values are reported for both the nitrides in their B1 and B3 phases. The high-pressure NaCl phase of both CoN and NiN were found to be ferromagnetic.

El CO2 como disolvente y como reactivo

OpenAIRE

La Franca Pitarresi, Vincenzo Rosario

2016-01-01

Existen numerosas ventajas asociada con el uso de CO2 , tanto como disolvente que como reactivo, y todas se pueden resumir en cuatro categorías generales: beneficios ambiental, beneficios de salud y seguridad, beneficios en el procedimiento y beneficios químicos. Los procesos que implican el CO2 como disolvente no aumentaría las emisiones de CO2, más bien proporcionaría una oportunidad para el reciclaje de CO2 residual. Además, los esfuerzos para secuestrar el CO2 producido de los gases de co...

Geoquímica de las aguas termales con CO2 del SE de las Cordilleras Béticas

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Martín-Vallejo, M.

1998-12-01

el condicionamiento geológico, la definición y sistematización de sus facies químicas y las temperaturas de base, entre otros, mostrando siempre su notable desarrollo y conexión con anomalías geotérmicas de carácter regional. Una de las cuestiones que parece revestir implicaciones genéticas importantes, así como para la utilización de estas aguas, es su contenido en dióxido de carbono. Se han estudiado veintisiete parámetros fisicoquímicos en veintidós puntos de agua sobre un inventario de cincuenta. La mayoría de los puntos acuíferos estudiados tienen una elevada temperatura, comprendida entre 20 y 41°C. Las aguas tienen conductividades que varían entre 771 y 5.030 μS cm-1, y que se incrementan hacia el Este de los sistemas de fallas de Carboneras- Palomares-Guadalentín. En general, las concentraciones de ion bicarbonato son elevadas, comprendidas entre 3 y 30 meq/l. Las aguas tiene PC02 altas, llegándose a medir valores superiores al, 17 atmósferas y cuyas variaciones espaciales están relacionadas con su proximidad a los sistemas de fallas de Carboneras-Palomares-Guadalentín, los cuales establecen un umbral entre diferentes espesores de la corteza. Todas las aguas se encuentran sobresaturadas en dolomita y subsaturadas en yeso, y en general saturadas en calcita. Los altos contenidos en CO2 de las aguas, además de los procesos de dedolomitización originados por la disolución de ion sulfato, contribuyen a la formación de travertinos, presentes en muchos de los puntos acuíferos estudiados. El estudio isotópico realizado permite ver que el δ13C tiene valores comprendidos entre -8,1 y -3,1‰, señalando la existencia de cantidades no despreciables de CO2 de origen profundo. El sistema hidrotermal de esta zona está relacionado con el propuesto «Cinturón de CO2 Perialpino », asociado aquí a una serie de grabens con actividades sísmica y neotectónica.

Estudio cinético de la reacción del CO con el O2 sobre un catalizador de Pd en alto vacío

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Luis M. Carballo Suárez

1988-01-01

Full Text Available La oxidación del monóxido de carbono con el oxígeno sobre una banda de Paladio policristalino bajo condiciones de estado estacionario se investigó con la ayuda de un espectrómetro de masas y con la utilización de monóxido de carbono marcado isotópicamente 13CO. A temperaturas entre 500 y 750 K se varía la proporción de las presiones parciales de los reactantes entre los límites 0,01 hasta 100, y la presión total en el reactor está siempre por debajo de 10-3 mbar. Los resultados experimentales se describen usando una secuencia de pasos elementales que incluye la adsorción y desorción molecular de los reactantes, y la reacción de las dos especies adsorbidas para formar CO2, siendo este último el paso controlante de la reacción. El modelo considera dos clases diferentes de sitios activos. Los cálculos basados sobre valores de los parámetros tomados de la literatura muestran un ajuste aproximado con los datos experimentales.

The effect of 60Co γ-rays on con A and LPS induced lymphocytes

International Nuclear Information System (INIS)

Su Liaoyuan; Liu Keliang; Ma Xiangrui

1987-01-01

The effect of 60 Co γ-rays on lymphocytes induced by Con A and LPS and the relationship between these two groups of cells were investigated by means of 3 H-TdR incorporation. The study showed that in vitro, Con A cells were able to promote the inducing effect of LPS to B cells. When Con A cells were irradiated by 10 Gy γ-rays, the 3 H-TdR incorporation value reduced significantly and the stimulating effect of Con A cells on LPS cells disappeared. Having been irradiated by γ-rays, LPS cells were not be able to be stimulated by normal Con A cells. When the groups of cells were incubated together after irradiation, the synergistic function disappeared, furthermore the suppressive effect of Con A cells on LPS cells emerged. When these two groups of cells were investigated by means of agar culture, the suppressive effect of 10 Gy γ-rays on lymphocytes colony formation was more obvious. Tests on 7 patients who were suffering from carcinoma of nasoparynx showed that after a course of treatment with 60 Co γ-rays, the incorporation value in Con A cells became much smaller, the stimulating effect of Con A cells on LPS cells disappeared. LPS cells could not be stimulated by normal Con A cells. The study demonstrated that the radiosensitivity of Con A cells is higher than that of LPS cells

Automatización del control del cálculo de extracciones en la mina de la empresa niquelera Ernesto Che Guevara

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Arístides A. Legrá-Lobaina

2010-03-01

Full Text Available En el artículo se muestran los elementos fundamentales de un algoritmo cuyo objetivo es establecer el contenido y el orden de los procedimientos necesarios para realizar el control del cálculo de extracciones en la mina de la empresa Ernesto Che Guevara que explota, a cielo abierto, yacimientos lateríticos ferroniquelíferos en la región de Moa, Cuba. Asimismo se presenta el diseño de los diálogos informáticos que han automatizado el algoritmo en la aplicación informática Tierra.

Estabilidad en el almacenamiento congelado de rebanadas de lomo de atún rojo (Thunnus sp. empacadas en atmósfera modificada con CO2

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Myrna Luisa Medina Bracamonte

2014-12-01

Full Text Available La disponibilidad atún rojo fresco, entero y rebanado, como todo producto pesquero fresco está restringida para los consumidores en zonas distantes a los centros de producción por su estabilidad limitada en el almacenamiento. Por ello la industria pesquera en general, en la época de mayor producción, recurre a la congelación para conservar el excedente de producción, y al empacado para protegerlo del ambiente frío y seco del congelador, evitar su deshidratación y “quemaduras por frío”. El surgimiento del Empacado en Atmósfera Modificada como alternativa para incrementar la vida útil de productos alimenticios despertó la inquietud de evaluar la estabilidad de rebanadas de lomo de atún rojo (Thunnus sp. fresco, congeladas y empacadas con 100 % de CO2 durante su almacenamiento a las temperaturas convencionales para su distribución y venta, -10 y -18 ºC, evaluando la estabilidad química, física, microbiológica y sensorial de las rebanadas de lomo de atún rojo durante ≈ 4 meses de almacenamiento congelado. El 50 % de las rebanadas se congeló a -10 ºC (Tratamiento 1 y el 50 % restante a -18 ºC (Tratamiento 2. Las rebanadas congeladas se empacaron individualmente, el 50 % en atmósfera de 100 % de CO2 conservando la proporción 1:2 (rebanada:gas y el 50 % restante en atmósfera de aire. Se almacenaron a la temperatura correspondiente: Tratamiento 1 a -10 ºC y Tratamiento 2 a -18 ºC durante 111 días. Al final del almacenamiento el tratamiento P2 (100 % CO2 ofreció mejor barrera a la pérdida de humedad, favoreció la estabilidad de la fracción de proteínas solubles en solución salina. Las muestras P2 tuvieron mayor aceptación sensorial, fueron las más oscuras y rojas, con menor recuento microbiológico, coincidiendo con el menor contenido en bases volátiles totales. A -10 ºC la atmósfera de 100 % de CO2 no evitó la “quemadura por frío” y los panelistas percibieron el “olor a pescado”.

Technical study of the CO{sub 2} capture process with monoethanolamine for a thermoelectric plant; Estudio tecnico del proceso de captura de CO{sub 2} con monoetanolamina para una planta termoelectrica

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Diaz, Abigail; Franco Nava, Jose Manuel; Peralta Martinez, Maria Vita; Gonzalez Santalo, Jose Miguel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Franco Lopez, Rogelio; Carreon Silva, Ramon [Comision Federal de Electricidad (Mexico)

2010-07-01

planta termoelectrica de 350 MW, que utilizaria carbon como combustible, en el simulador de procesos ASPEN HYSYS. Para este proceso se requieren dos columnas: una de absorcion, en la cual entran los gases y el solvente, que en este caso fue una solucion de monoetanolamina (MEA) al 30%. La MEA reacciona con el CO{sub 2} contenido en los gases, reteniendolo, de manera que los gases restantes que son emitidos al ambiente, ya no lo contienen. La MEA y el CO{sub 2} capturado pasan a la segunda columna donde estos dos componentes se separan, utilizando energia termica para regenerar la MEA liberando el CO{sub 2}. El CO{sub 2} liberado sale por la parte superior de la columna y la MEA recuperada, que es reutilizada en la columna de absorcion, por el fondo. La concentracion de CO{sub 2} en los gases de la combustion es de 14.54% volumen. La simulacion se realizo definiendo una eficiencia de captura de 90%, lo que arrojo un consumo de energia termica para regenerar la MEA de 4.75 GJt/ton CO{sub 2}, que seria suministrada por la central termoelectrica. Considerando una capacidad de gases a tratar de 280 ton/h (por tren) se determino la altura de las columnas de absorcion y desercion, asi como el flujo de solucion de MEA.

Magnetic Phase Transition in Ion-Irradiated Ultrathin CoN Films via Magneto-Optic Faraday Effect.

Science.gov (United States)

Su, Chiung-Wu; Chang, Yen-Chu; Chang, Sheng-Chi

2013-11-15

The magnetic properties of 1 nm thick in-plane anisotropic Co ultrathin film on ZnO(0001) were investigated through successive 500 eV nitrogen-ion sputtering. Magneto-optical Faraday effects were used to observe the evolution of the ion-irradiated sample in longitudinal and perpendicular magnetic fields. The ferromagnetic phase of the initial in-plane anisotropic fcc β-Co phase transformation to β-Co(N) phase was terminated at paramagnetic CoN x phase. In-plane anisotropy with weak out-of-plane anisotropy of the Co/ZnO sample was initially observed in the as-grown condition. In the sputtering process, the N⁺ ions induced simultaneous sputtering and doping. An abrupt spin reorientation behavior from in-plane to out-of-plane was found under prolonged sputtering condition. The existence of perpendicular anisotropy measured from the out-of-plane Faraday effect may be attributed to the co-existence of residual β-Co and Co₄N exchange bonding force by the gradual depletion of Co-N thickness.

Caracterización de las cirugías palpebrales con láser de CO2 Characterization of the eyelid surgery with CO2 laser

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Lázara Kenia Ramírez García

2012-06-01

Full Text Available Objetivo: Determinar la caracterización de las cirugías palpebrales con láser de CO2. Métodos: Estudio observacional, descriptivo, longitudinal prospectivo, cuya muestra estuvo constituida por 93 pacientes (136 ojos operados con láser de dióxido de carbono en el Servicio de Oculoplastia del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" desde enero a octubre de 2009. Resultados: Según el sexo, 40 eran femeninos y 53 masculinos. Por edad, de 20 a 39 años, 9,7 %; de 40 a 59, 15 %; de 60 a 79, 48,4 %; y más de 80 años, 23,7 %. La piel tipo I se presentó en el 53,8 % de los pacientes, el tipo II en 33,3 %. El láser se utilizó como instrumento de corte y coagulación en la dermatochalasis (31,6 % y en el ectropión (20,6 %. Como escáner en 11 queratosis seborreicas. El 94,6 % no mostró complicaciones, solo 5 pacientes. Conclusiones: Este equipo se utilizó en múltiples afecciones anexiales. La técnica quirúrgica transcutánea predominó en más de la mitad de los pacientes con dermatochalasis y la fijación cantal externa en las anomalías de posición. Las complicaciones fueron mínimas y la retracción cicatrizal fue la más frecuente.Objective: To determine the behavior of eyelid surgery with CO2 laser. Methods: A prospective, longitudinal, observational and descriptive study whose sample consisted of 136 eyes from 93 patients, who underwent carbon dioxide laser surgery at the oculoplasty service of "Ramón Pando Ferrer" Cuban Institute of Ophthalmology from January to October, 2009. Results: Of the total number of patients, 40 were females and 53 males; 9.7% aged 20 to 39 years, 15% aged 40 to 59 years; 48.4 % were 60 to 79 years and 23.7% over 80 years. Skin type I was present in 50 patients (53,8 %, and type II in 33,3 % of cases. C02 laser was used for cutting and coagulation in dermatochalasis, accounting for 31.6% and in ectropion for 20,6 %. As a scanner it was used in 11 seborrheic keratoses. No complications

Oxacilin-resistant Coagulase-negative staphylococci (CoNS) bacteremia in a general hospital at São Paulo city, Brasil

Science.gov (United States)

d’Azevedo, P.A.; Secchi, C.; Antunes, A.L.S.; Sales, T.; Silva, F.M.; Tranchesi, R.; Pignatari, A.C.C.

2008-01-01

In the last decades, coagulase-negative staphylococci (CoNS), especially Staphylococcus epidermidis have become an important cause of bloodstream infections. In addition, rates of methicillin-resistance among CoNS have increased substantially, leading to the use of glicopeptides for therapy. The objective of this study was to evaluate eleven consecutives clinically relevant cases of oxacillin-resistant CoNS bacteremia in a general hospital localized in São Paulo city, Brazil. Five different species were identified by different phenotypic methods, including S. epidermidis (5), S. haemolyticus (3), S. hominis (1), S. warneri (1) and S. cohnii subsp urealyticus (1). A variety of Pulsed Field Gel Electrophoresis profiles was observed by macrorestriction DNA analysis in S. epidermidis isolates, but two of three S. haemolyticus isolates presented the same profile. These data indicated the heterogeneity of the CoNS isolates, suggesting that horizontal dissemination of these microorganisms in the investigated hospital was not frequent. One S. epidermidis and one S. haemolyticus isolates were resistant to teicoplanin and susceptible to vancomycin. The selective pressure due to the use of teicoplanin in this hospital is relevant. PMID:24031279

A study of coagulase-negative staphylococci (CoNS isolated from bovine mastitis for the presence of penicillin and methicillin resistance-encoding genes in the north west of Iran

Directory of Open Access Journals (Sweden)

Dastmalchi Saei, H.

2014-11-01

Full Text Available Coagulase-negative staphylococci (CoNS are often associated with bovine mastitis and may be resistant to antimicrobial therapy. The aim of the current study was to investigate the presence of blaZ (responsible for penicillin resistance and mecA (responsible for methicillin resistance genes among 108 CoNS belonging to 9 different species isolated from bovine mastitis in seven dairy herds (H1-H7. Of 108 CoNS isolates, 44 were Staphylococcus haemolyticus, 17 S. chromogenes, 11 S. epidermidis, 11 S. warneri, 11 S. cohnii, 6 S. simulans, 4 S. hominis, 3 S. capitis, and 1 S. xylosus. The blaZ was detected in 65.7% (n=71 of all Staphylococcus spp. isolates. Five isolates were positive for the presence of mecA gene (4.6%, including 2 S. hominis, 1 S. haemolyticus, 1 S. epidermidis, and 1 S. warneri. All mecA-carrying CoNS were also positive for the blaZ gene and were recovered from two studied herds (H3 and H6. Some variations were also observed in distribution of both blaZ and mecA genes between CoNS species. This study demonstrates that CoNS from bovine mastitis can be reservoirs of blaZ gene. This study also provides evidence of the presence of methicillin resistant CoNS (MR-CoNS and emphasizes the need for their epidemiological monitoring, in order to prevent the risk of spread to human through direct contact and/or consumption of contaminated food.

Trace gases and CO sub(2) isotope records from Cabo de Rama, India

Digital Repository Service at National Institute of Oceanography (India)

Bhattacharya, S.K.; Borole, D.V.; Francey, R.J.; Allison, C.E.; Steele, L.P.; Krummel, P.; Langenfelds, R.; Masarie, K.A.; Tiwari, Y.K.; Patra, P.K.

to avoid dan- gerous climate change due to GHG forced warming. Con- centrations of CO 2 , CH 4 and N 2 O have increased at alarming rates, from preindustrial values of 280 ppm, 715 ppb and 270 ppb (circa. 1750) to 379 ppm, 1732 ppb and 319 ppb... an important effect on the con- centration and isotopic composition of atmospheric CO 2 , and the concentrations of other trace gases. Air sampling at CRI contributes to the global atmospheric composition study 10,11 . Given the potential for global impacts...

Ab initio study of the CO-N2 complex: a new highly accurate intermolecular potential energy surface and rovibrational spectrum

DEFF Research Database (Denmark)

Cybulski, Hubert; Henriksen, Christian; Dawes, Richard

2018-01-01

A new, highly accurate ab initio ground-state intermolecular potential-energy surface (IPES) for the CO-N2 complex is presented. Thousands of interaction energies calculated with the CCSD(T) method and Dunning's aug-cc-pVQZ basis set extended with midbond functions were fitted to an analytical...... function. The global minimum of the potential is characterized by an almost T-shaped structure and has an energy of -118.2 cm-1. The symmetry-adapted Lanczos algorithm was used to compute rovibrational energies (up to J = 20) on the new IPES. The RMSE with respect to experiment was found to be on the order...... of 0.038 cm-1 which confirms the very high accuracy of the potential. This level of agreement is among the best reported in the literature for weakly bound systems and considerably improves on those of previously published potentials....

CO2 effect on porous concrete

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Sauman, Zdenek

1974-09-01

Full Text Available Not availableDebido a la acción del CO2 y de la humedad sobre un hormigón poroso, la tobermorita 11 A se descompone en vaterita, calcita y SÍO2 gel. A causa de la pseudomorfosis, la morfología de los cristales de la fase cementante no sufre cambios notables. La menor resistencia a la compresión se obtuvo después de 30 días de conservación en atmósferas de un 10 y un 30% de CO2. Después de un año de conservación, las resistencias no bajaron más de un 10%. En lo que respecta a la retracción de un hormigón poroso, la principal influencia fue la ejercida por la acción del CO2 y solamente en segundo lugar figura la acción ejercida por la humedad ambiente. Los hormigones porosos expuestos al aire (con su 0,03% de CO2 a h. r. de 50, 70 y 100% sufrieron al cabo de un año una expansión muy ligera.

Supercritical CO2 extraction of oil and omega-3 concentrate from Sacha inchi (Plukenetia volubilis L.) from Antioquia, Colombia; Extracción con CO2 supercrítico de aceite y un concentrado de omega-3 a partir de Sacha inchi (Plukenetia volubilis L.) proveniente de Antioquia, Colombia.

Energy Technology Data Exchange (ETDEWEB)

Torijano-Gutiérrez, S.A.; Triana-Maldonadoa, D.M.; Giraldo-Estradaa, C.

2017-07-01

Sacha inchi (Plukenetia volubilis L.) seeds were employed for oil extraction with supercritical CO2 at laboratory scale. The supercritical extraction was carried out at a temperature of 60 °C, pressure range of 400–500 bars and CO2 flow of 40–80 g/min. The maximum recovery was 58% in 180 min, favored by increasing the residence time of CO2 in the extraction tank. Subsequently, the process was evaluated at pilot scale reaching a maximum recovery of 60% in 105 min, with a temperature of 60 °C, pressure of 450 bars and CO2 flow of 1270 g/min. The fatty acid composition of the oil was not affected for an extraction period of 30–120 min. The Sacha inchi oil was fractionated with supercritical CO2 to obtain an omega-3 concentrate oil without finding a considerable increase in the proportion of this compound, due to the narrow range in the carbon number of fatty acids present in the oil (16–18 carbons), making it difficult for selective separation. [Spanish] Semillas de Sacha inchi fueron empleadas para la extracción de su aceite con CO2 supercrítico a escala de laboratorio, a una temperatura de 60 °C, entre 400–500 bares de presión y un flujo de CO2 entre 40–80 g/min, obteniendose una recuperación máxima del 58% en 180 min favorecida por el aumento en el tiempo de residencia del CO2 en el tanque de extracción. Posteriormente, se evaluó el proceso a escala piloto, alcanzando una recuperación máxima del 60% en 105 min de extracción, a una temperatura de 60 °C, presión de 450 bares y flujo de CO2 de 1270 g/min, sin afectar la composición de los ácidos grasos del aceite durante un periodo de extracción entre 30–120 min. El aceite de Sacha inchi fue fraccionado con CO2 supercrítico para la obtención de un aceite concentrado de omega-3, sin encontrar aumento considerable en la proporción de este compuesto debido al estrecho rango en el número de carbonos (16–18 carbonos) de los ácidos grasos presentes en el aceite, lo que dificulta su

Intervenciones Farmaceuticas en pacientes con Diabetes Mellitus Tipo 2

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Gladys Mabel Maidana

Full Text Available Resumen Introducción: La Atención Farmacêutica es la provision responsable de la farmacoterapia con el propósito de alcanzar resultados concretos que mejoren la calidad de vida de los pacientes. Objetivo: Evaluar el impacto de las intervenciones farmacéuticas en pacientes con Diabetes Mellitus Tipo 2. Metodologia: Ensayo Clínico Aleatorizado, con medición de variables antes y después. No probabilísti-co. De conveniencia. Participaron 32 pacientes del grupo intervenido y 32 en grupo control. Se realizaron entrevistas mensuales en un periodo de intervención farmacéutica de 6 meses (desde octubre 2011 hasta junio 2012. Se registraron solo 3 abandonos. Resultados: La edad de los pacientes fue 55,6±10,6 anos. Los pacientes del grupo intervenido mejoraron la glicemia en 34%, donde 24 pacientes tenian el valor (< 130 mg/dL; la hemoglobina glicosilada mejoró 1,9%, donde 15 pacientes lograron los parámetros deseados (< 6,5%. La calidad de vida del grupo inter-venido aumentó de (56,3 a 71,3 % y fue medido con el cuestionario SF-36. En el grupo intervenido se encontraron 80 problemas relacionados con medicamentos, en 27 pacientes, se resolvieron 59; al final del estudio 12 pacientes resolvieron todos los problemas relacionados con medicamentos; se realizaron 254 intervenciones farmacêuticas, el nivel de conocimiento de los pacientes sobre la enfermedad mejoró en 41%, el conocimiento sobre sus medicamentos mejoró en 53%. Conclusión: Las intervenciones farmacêuticas mejoraron los parámetros clínicos de glicemia, hemoglobina glicosilada, optimizaron el uso de medicamentos, disminuyeron los problemas relacionados con medicamentos, mejoraron la calidad de vida de los pacientes.

Aprende Ajedrez con Rey - Parte 2

OpenAIRE

ESTÉVEZ MONTERO, RAÚL; Lloret Mauri, Jaime

2016-01-01

Es una pieza audiovisual creada con el objeto de atraer la atención de los niños de muy corta edad con el ajedrez y familiarizarlos con todas sus piezas y movimientos. Es una animación dirigida a un público infantil presentada por dibujos animados en 2D, en la que se ha intentado respetar en todo momento el argot de la comunidad ajedredística. En este video se presenta la segunda parte. Estévez Montero, R.; Lloret Mauri, J. (2016). Aprende Ajedrez con Rey - Parte 2. http://hdl.handle.net/1...

Influence of the cation substitution on the magnetic properties of LiCo2O4 and Li(Me,Co2O4 spinels

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Gautier, J. L.

2004-08-01

Full Text Available Lithium-based cells LiCo2O4 have been characterized by magnetic techniques, looking at the influence of the partial substitution of cobalt by 3d or 4d transition metal elements (Fe, Ni, Cu, Cr, Mo. The non-substituted compound LiCo2O4 behaves as an antiferromagnet, with a Néel temperature TN of 30 K, although antiferromagnetic interactions are much more important, as suggested by a Weiss parameter Θ of the order of ‑225 K. In the solid solution Li(NixCo2‑xO4 the Weiss parameter Θ changes with x(Ni, reaching large positive values (e.g., Θ ~ +230 K, for x = 0.5. This phenomenon suggests the existence of a canted‑antiferromagnetic or ferrimagnetic structures with large ferromagnetic components. Substitution of cobalt by other 3d or 4d transition metals in the LiMe0.5Co1.5O4 series shows dramatic effects with respect to the non-substituted LiCo2O4 compound : copper completely suppresses the magnetic order, while iron increases TN to almost room temperature. No modifications are observed when molybdenum substitutes cobalt, while chromium transforms the AF order in a ferromagnetic one, with Tc of about 90 K.Se ha caracterizado por técnicas magnéticas, el efecto de la sustitución parcial de Co por elementos de transición 3d o 4d (Fe, Ni, Cu, Cr, Mo en celdas LiCo2O4 a base de litio. El compuesto no sustituído LiCo2O4, se comporta como un antiferromagneto de temperatura de Néel TN de 30 K, aunque existen interacciones antiferromagnéticas mucho más importantes, como lo indica un parámetro de Weiss Θ del orden de -225K. En la solución sólida Li(NixCo2‑xO4, el parámetro de Weiss Θ cambia con x(Ni, alcanzando valores positivos altos (e.g., Θ ~ +230K, para x=0.5. Este fenómeno sugiere la existencia de una estructura antiferromagnética inclinada (“AF-canted” o de una estructura ferrimagnética, donde predominan componentes ferromagnéticas importantes. La sustitución del cobalto por otros elementos de transición 3d o 4d en

Variation of intrinsic magnetic parameters of single domain Co-N interstitial nitrides synthesized via hexa-ammine cobalt nitrate route

Energy Technology Data Exchange (ETDEWEB)

Ningthoujam, R.S. [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India); Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Panda, R.N., E-mail: rnp@bits-goa.ac.in [Chemistry Group, Birla Institute of Technology and Science-Pilani, Goa Campus, Zuari Nagar, Goa 403726 (India); Gajbhiye, N.S. [Department of Chemistry, Indian Institute of Technology, Kanpur 208016 (India)

2012-05-15

Highlights: Black-Right-Pointing-Pointer Variation of intrinsic magnetic parameters of Co-N. Black-Right-Pointing-Pointer Synthesis by hexa-ammine cobalt complex route. Black-Right-Pointing-Pointer Tuning of coercivity by variation of size. - Abstract: We report the variation of Curie temperature (T{sub c}) and coercivity (H{sub c}) of the single domain Co-N interstitial materials synthesized via nitridation of the hexa-ammine Cobalt(III) nitrate complex at 673 K. Co-N materials crystallize in the fcc cubic structure with unit cell parameter, a = 3.552 Angstrom-Sign . The X-ray diffraction (XRD) peaks are broader indicating the materials to be nano-structured with crystallite sizes of 5-14 nm. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies confirm the nanocrystalline nature of the materials. TEM images show chain-like clusters indicating dipolar interactions between the particles. Magnetic studies focus on the existence of giant magnetic Co atoms in the Co-N lattice that are not influenced by the thermal relaxation. The values of the H{sub c} could be tuned with the dimension of the particles. The values of T{sub c} of the nitride materials are masked by the onset of the ferromagnetic to superparamagnetic transition at higher temperatures. Thermomagnetic studies show an increasing trend in the Curie temperature, T{sub c}, with decrease in particle dimension. This result has been explained qualitatively on the basis of ferromagnetic to superparamagnetic transition and finite size scaling effects.

Extraction of oil from pequi fruit (Caryocar Brasiliense, Camb. using several solvents and their mixtures

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Antoniassi, R.

2011-09-01

Full Text Available In this study, the oil extraction process from pequi pulp using different solvents (hexane, acetone and ethyl alcohol and their mixtures was investigated, using a simplex-centroid design. The extraction occurred at 50°C, under stirring (22 Hz, for 16 hours. The solid-liquid ratio used was 1:10 (w/w. Higher yield values were obtained for extractions with acetone and hexane, especially their mixtures with ethanol. Iodine value, saponification value and refractive index did not differ significantly among the treatments. A higher acid value was obtained for the extraction with ethyl alcohol. Higher carotenoid contents were obtained for the extraction with acetone and ethyl alcohol as pure solvents. The fatty acid profile in the oil fraction of the extracts did not vary among the different types of solvents and their mixtures.En este trabajo fue estudiado el proceso de extracción de aceite de la pulpa de pequi utilizando diferentes disolventes (n-hexano, acetona y etanol y sus mezclas, empleando diseño central simplex. Las extracciones fueron realizadas a 50°C, durante 16 horas de agitación (22 Hz. La proporción sólido:líquido empleada fue 1:10 (p/p. Los mayores rendimientos fueron obtenidos para las extracciones con acetona y con hexano, especialmente cuando fueron mezclados con etanol. El índice de yodo, el índice de saponificación y el índice de refracción no difirieron significativamente entre los tratamientos. Los mayores valores de acidez se obtuvieron en la extracción con etanol. Los mayores contenidos en carotenoides se obtuvieron en las extracciones con acetona y etanol como disolventes puros. El perfil de los ácidos grasos en las fracciones de aceite de los extractos no presentó variación entre los diferentes tipos de disolventes y sus mezclas.

Racionalización de la técnica para la determinación de la concentración de lidocaína al 2 %

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María Victoria Licea Tornés

1997-12-01

Full Text Available El clorhidrato de lidocaína es un anestésico local que se utiliza tanto por vía endovenosa como subcutánea, en dependecia de su forma de presentación, con o sin preservo respectivamente. La determinación de la concentración de clorhidrato de lidocaína en el inyectable se realiza mediante un método anhidrovolumétrico que requiere un gasto considerable de reactivo de importación. Para racionalizar esta técnica, se realizaron ensayos preliminares en los cuales se varió el volumen de extrayente y el número de extracciones. Los mejores resultados se obtuvieron con 10 mL de cloroformo en 3 extracciones, lo que permitió un ahorro aproximado del 70 % de este solvente.The lidocaine chlorhydrate is a local anesthestic that may be used by endovenous or subcutaneous route, depending of its form of presentation, with or without preserve. The concentration of lidocaine chlorhydrate in the injection is determined by an anhydrovolumetric method that requires a considerable use of imported reactive. Preliminary assays were made in which the volumen of extraction as well as the number of extractions were varied in order to rationalize this technique. The best results were obtained with 10 mL of chloroform in 3 extractions, which allowed the saving of 70 % of this solvent.

Greenhouse Gas (CO2 AND N2O Emissions from Soils: A Review Emisión de Gases invernadero (CO2 y N2O desde Suelos

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Cristina Muñoz

2010-09-01

Full Text Available In agricultural activities, the main greenhouse gases (GHG are those related to C and N global cycles. The impact of agriculture on GHG emissions has become a key issue, especially when considering that natural C and N cycles are influenced by agricultural development. This review focuses on CO2 and N2O soil emissions in terrestrial ecosystems, with emphasis in Chilean and similar agro-ecosystems around the world. The influence of land use and crop management practices on CO2 and N2O emissions is analyzed; some mitigation measures to reduce such emissions are also discussed here. More knowledge on the biological processes that promote of GHG emissions from soil will allow creating opportunities for agricultural development under friendly-environmental conditions, where soil can act as a reservoir and/or emitter of GHG, depending on the balance of inputs and outputs.En actividades agrícolas los principales gases de efecto invernadero (GHG son los relacionados con los ciclos globales de C y N. El impacto de la agricultura sobre las emisiones GHG se ha convertido en una cuestión clave, especialmente si se considera que los ciclos naturales C y N se ven influidos por el desarrollo agrícola. Esta revisión se centra en emisiones de CO2 y N2O del suelo en los ecosistemas terrestres, con énfasis en agro-ecosistemas de Chile y similares alrededor del mundo. Se analiza la influencia del uso del suelo y las prácticas de manejo del cultivo sobre emisiones de CO2 y N2O, se discuten medidas de mitigación para reducir estas emisiones. Un mayor conocimiento sobre los procesos biológicos que promueven las emisiones GHG del suelo permitirá la creación de oportunidades para el desarrollo agrícola en condiciones ambientalmente amigables, donde el suelo puede actuar como un reservorio y/o emisor de GHG, dependiendo del balance de entradas y salidas.

EXTRACCIÓN DE HIDROCARBURO PESADO EN SUELO ARENOSO

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Carolina G. Martínez-Chávez

2017-01-01

Full Text Available Una de las técnicas más utilizadas en la extracción de hidrocarburo en cuant o a fracción pesada de petróleo es el método que se estable ce en la Norma Oficial Mexic ana NMX - AA - 134 - SCFI - 2006, la cua l indica un tiempo de extracción determinado (6 horas. Basado en lo anterior, en este trabajo se evalu ó y compar ó la extracción de hidrocarburo pesado en un suelo arenoso a diferentes tiempos (6 y 8 horas empleando dos disolventes (hexano y d iclorometano con la misma polaridad pero con diferentes constantes dieléctricas. Los suelos se contaminaron con hidrocarburo pesado (45000 mg∙ kg - 1 y se realizaron extracciones continuas por triplicado utilizando el método Soxhlet . Luego, se cuantific ó la extracción de cada eluyente. Se concluyó que el d iclorometano favorece la extracción a menor tiempo ya que no se observó diferencias en las extracciones a 6 y 8 horas, pero si una diferencia con respecto a hexano en ambos tiempos.

de riego 03, Valle de Mezquital, Hidalgo, México

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F. Prieto-García

2007-01-01

Full Text Available En este trabajo se realiza el estudio de caracterización fisicoquímica y de extracciones secuenciales selectivas de metales trazas, tóxicos y no biodegradables y el metaloide arsénico, en suelos de la zona Actopan-Ixmiquilpan. La caracterización fisicoquímica se realizó mediante determinaciones de texturas de suelos, materia orgánica, pH, entre otros, para clasificar los suelos; paralelamente se realizaron evaluaciones de extracciones secuenciales selectivas de metales trazas (Pb, Cd, Cr y Hg y del metaloide As, siguiendo el esquema de Tessier et al. (1979, con el fin de correlacionar las características de estos suelos con los tiempos de irrigación, la cual se realiza con aguas negras desde hace más de 20 años (para esta zona. En general se encontró una correlación directa de los tiempos de irrigación con los contenidos de materia orgánica y una acumulación apreciable de Pb y Cr fundamentalmente, que puede acarrear problemas a más largo plazo por contaminación de cultivos.

Thermoelectric power plant conversion from fuel oil to coal with integration of a CO{sub 2} capture plant. Part 1; Conversion de una central termoelectrica de combustoleo a carbon con integracion de una planta de captura de CO{sub 2}. Parte 1

Energy Technology Data Exchange (ETDEWEB)

Huante Perez, Liborio; Rodriguez Martinez, J. Hugo; Arriola Medellin, Alejandro M. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2010-11-15

The major features in the design of power plant conversion from fuel oil to coal, considering the new technical characteristics of fuel and his transportation to plant, equipment required to comply with Mexican environmental standards and additional requirements of auxiliaries are described. In addition, changes needed on power plant design were considered according to integrates CO{sub 2} capture plant alternatives. [Spanish] En este articulo se describen las caracteristicas principales en el diseno de la conversion de Centrales de combustoleo a carbon, considerando el nuevo combustible y su transporte hasta la central, los equipos requeridos para cumplir con las normas ambientales y los requerimientos adicionales de los servicios auxiliares. Adicionalmente, se lleva a cabo el analisis de los cambios requeridos en el diseno de la conversion considerando diferentes opciones para la integracion de una planta de captura de CO{sub 2}, la cual debera entregar este subproducto para su compresion y envio a su destino final para su almacenamiento.

Co-N-macrocyclic modified graphene with excellent electrocatalytic activity for lithium-thionyl chloride batteries

International Nuclear Information System (INIS)

Li, Bimei; Yuan, Zhongzhi; Xu, Ying; Liu, Jincheng

2016-01-01

Highlights: • A Co-N-graphene catalyst composed of CoN 4 -macrocyclic-like (CoN x ) structure is synthesized. • Co-N x -Graphene has effective electrocatalytic activity for Li/SOCl 2 batteries. • The storage stability of the catalyst is attributed to its insolubility in electrolyte. - Abstract: A mixture of cobalt phthalocyanine (CoPc) and graphene is thermally decomposed at 800 °C to synthesize a novel catalyst. Scanning electron microscopy (SEM) and transmission electron microscope (TEM) show that the catalyst retains the lamellar structure of graphene. X-ray diffraction (XRD) reveals that the catalyst is no longer composed of CoPc and high-resolution TEM (HRTEM), X-ray photoelectron spectra (XPS) prove that Co and N elements have entered the graphene molecular structure, thus forming a Co-N x -graphene (Co-N x -G) catalyst composed of a CoN 4 -macrocyclic-like structure. This catalyst serves as an excellent catalyst of thionyl chloride (SOCl 2 ) reduction. Cyclic voltammetry and battery discharge tests reveal that Co-N x -G-800 substantially increases the discharge voltage and capacity of a Li/SOCl 2 battery. Moreover, Co-N x -G-800 exhibits stable catalytic activity during battery storage. Ultraviolet–visible spectroscopy shows that CoPc is soluble in a SOCl 2 electrolyte solution, whereas Co-N x -G-800 is not, this characteristic contributes to the stable catalytic property of Co-N x -G.

Vehicle emissions of greenhouse gases and related tracers from a tunnel study: : CO: CO2, N2O: CO2, CH4: CO2, O2: CO2 ratios, and the stable isotopes 13C and 18O in CO2 and CO

NARCIS (Netherlands)

Popa, Maria Elena; Vollmer, M. K.; Jordan, A.; Brand, W. A.; Pathirana, S. L.; Rothe, M.; Röckmann, T.

2014-01-01

Measurements of CO2, CO, N2O and CH4 mole fractions, O2/N2 ratios and the stable isotopes 13C and 18O in CO2 and CO have been performed in air samples from the Islisberg highway tunnel (Switzerland). The molar CO : CO2 ratios, with an average of (4.15 ± 0.34) ppb:ppm, are lower than reported in

Diagramas de equilibrio para la extracción con solvente de aceite e insecticida de semilla molida de nim

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R. Espinosa

2006-01-01

Full Text Available En este trabajo se construyeron diagramas de equilibrio para la extracción con hexano de aceite de la semilla molida de nim (GNSK y de la extracción posterior con etanol de insecticida de la GNSK sin aceite. Los datos experimentales fueron obtenidos a diferentes temperaturas, poniendo en contacto sólido y solvente en diferentes proporciones en frascos Erlenmeyer. Se suministró agitación y se mantuvo la temperatura controlada hasta alcanzar el equilibrio. La composición del extracto y del refinado se determinó separando los solventes por evaporación. Se propone ecuaciones para la curva de refinado y la curva de distribución. En ambas extracciones, la fracción de solución retenida dentro de la estructura celular del sólido molido aumenta con la temperatura. La concentración del extracto tiene más influencia en la cantidad de solución retenida para la extracción de insecticida que para la extracción de aceite. Para extractos diluidos, la concentración de soluto tiende a ser mayor en el extracto que en la solución retenida. Esta tendencia es más pronunciada cuando la temperatura aumenta. A temperaturas cercanas al punto de ebullición, hay mayor tendencia a la retención de solvente por el sólido, a cualquier concentración.

A refined protocol for calculating air flow rate of naturally-ventilated broiler barns based on co2 mass balance

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Luciano Barreto-Mendes

2014-01-01

Full Text Available Este estudio se realizó para evaluar protocolos relativamente simples para el monitoreo de la tasa de ventilación (TV en instalaciones pecuarias con ventilación natural (ENV. Los protocolos de ensayo se aplicaron primero a una instalación de pollos de engorde mecánicamente ventilada (EMV, donde TV se estimó con mayor precisión y luego se utilizaron para calcular la TV en la ENV. Las concentraciones de CO2 se midieron con dos esquemas de muestreo diferentes: (S1 la media de las mediciones al interior y a lo largo de la longitud de la instalación a dos alturas de 0,5 m y 1,5 m del suelo; y (S2 igual que la anterior pero con las mediciones de concentración fueron realizadas únicamente a 0,5 m del suelo. La tasa de producción de CO2 metabólico dinámico de las aves se predijo con dos algoritmos diferentes: (A1 el mantenimiento constante durante los periodos de luz y oscuridad, y (A2 que varía con la actividad de los animales sobre una base horaria. Los resultados demostraron que la combinación de S2 con A1 o A2 presentó la mejor estimación de TV en el ENV.

How the oil companies look at CO2 separation and disposal

International Nuclear Information System (INIS)

Kaarstad, O.

2001-01-01

Separation and disposal of CO 2 is a new complex problem, and we should not be surprised that the technology available today does not solve all our problems. Neither should we be surprised that politicians, environmentalists, industry leaders and the general public have problems to digest the idea of underground disposal of CO 2 . The main challenges we are facing are: Reducing the investment and operational costs for CO 2 -separation; Finding solutions that do not create new environmental problems; Finding cheaper methods for transport of medium volumes of C= 2 over long distances; Keep informing the public of the pros and cons of underground disposal; Finding good transition strategies; Look for ways of cooperation between industry, authorities and research organizations to manage the transition period, including adaption of legislation to the new situation

Evaluación de la co-digestión anaerobia de lodos de aguas residuales municipales con residuos de alimentos

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Ileana Consuelo Julio Guerrero

2016-06-01

Full Text Available La digestión anaerobia es un proceso ampliamente utilizado para el tratamiento de los lodos producidos en las plantas de tratamiento de agua residual, debido a sus ventajas técnicas y económicas. Este artículo presenta un estudio en el que se evaluó la co-digestión de lodos de aguas residuales con residuos de alimentos (RA como una estrategia para optimizar la digestión de los lodos. Se realizaron mono-digestiones y co-digestiones de los sustratos en condiciones mesofílicas (35°C usando reactores por lotes. Los lodos utilizados fueron: lodo primario (LP, lodo secundario espesado (LSE y una mezcla de LP con LSE en la proporción 60:40 con base en sólidos totales (LP:LSE. Las co-digestiones se realizaron usando distintas proporciones de mezclas de los sustratos con base en sólidos volátiles totales: LP:RA=30:70, LP:RA=50:50, LP:RA=70:30 y (LP+LSE:RA=70:30. La máxima producción de metano, 0,25LCH4/gSVadicionado, se obtuvo para la mezcla LP:RA=30:70, presentando una producción 32% mayor que la obtenida en la mono-digestión del lodo primario.

Actividad química de los ligandos puente difósforo y difosfenilo en los complejos binucleares (Mo2Cp2(n-PCy2) (n-K2:K2-P2)(CO)2)-y (Mo2Cp2(n-PCy2)(n-K2:K2-P2Me)(CO)2)

OpenAIRE

Lozano Rivera, Raquel

2015-01-01

El trabajo de investigación que se recoge en la presente Memoria comprende un amplio estudio de la reactividad de complejos metálicos binucleares con ligandos puente difósforo y metildifosfenilo procedentes de la activación directa del fósforo blanco. Por un lado, se ha llevado a cabo un amplio análisis del comportamiento químico de la especie aniónica [Mo2Cp2(¿-PCy2)(¿-¿2:¿2-P2)(CO)2]- frente a electrófilos de distinta naturaleza, tales como clorofosfinas y complejos metálicos generadores...

Efecto del sistema de aturdimiento con CO2, tiempo de desangrado y estimulación eléctrica post-mortem en la calidad de la carne de pavo

OpenAIRE

Mauri López, Mª Soledad

2017-01-01

El aturdimiento de los animales previo al sacrificio es una práctica obligatoria en todos los mataderos para evitar su sufrimiento. El aturdimiento gaseoso por CO2 se introdujo en la década de los 90 del siglo XX en las plantas de procesado de aves y presenta mejoras en la calidad final de las canales (ausencia de huesos rotos, disminución de hematomas y petequias) en comparación con el aturdimiento eléctrico, más común en las plantas de procesado de aves. Sin embargo, la ...

Evaluation of cross-section data from threshold to 40-60 MeV for specific neutron reactions important for neutron dosimetry applications. Part 1: Evaluation of the excitation functions for the 27Al(n,α)24Na, 55Mn(n,2n)54Mn, 59Co(n,p)59Fe, 59Co(n,2n)58m+gCo and 90Zr(n,2n)89m+gZr reactions

International Nuclear Information System (INIS)

Zolotarev, K.I.

2009-04-01

Evaluations of cross sections and their associated covariance matrices have been carried out for five dosimetry reactions: - excitation functions were re-evaluated for the 27 Al(n,α) 24 Na, 55 Mn(n,2n) 54 Mn and 90 Zr(n,2n) 89m+g Zr reactions over the neutron energy range from threshold to 40 MeV; - excitation functions were re-evaluated for the 59 Co(n,p) 59 Fe and 59 Co(n,2n) 58m+g Co reactions over the neutron energy range from threshold to 60 MeV. Uncertainties in the cross sections for all of those reactions were also derived in the form of relative covariance matrices. Benchmark calculations performed for 235 U thermal fission and 252 Cf spontaneous fission neutron spectra show that the integral cross sections calculated from the newly evaluated excitation functions exhibit improved agreement with related experimental data when compared with the equivalent data from the IRDF-2002 library. (author)

Diseño experimental de un sumidero de CO2 y sus implicaciones en el cambio climático. Una experiencia de trabajo con alumnos en el laboratorio de Educación Secundaria

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Raquel Boronat-Gil

2018-01-01

Full Text Available El desarrollo teórico del cambio climático en el aula de Educación Secundaria requiere de experiencias recreativas que demuestren –in situ– diferentes aspectos del proceso global. La presente comunicación muestra una actividad de laboratorio, y el consiguiente trabajo del alumnado, para comprobar la reducción de gases de efecto invernadero mediante la aplicación de una tecnología básica, de bajo costo y que puede realizarse con materiales disponibles en cualquier laboratorio escolar. La analogía didáctica llevada a cabo entre el CO2 producido por el metabolismo microbiano dentro de una botella cerrada y su reacción con una base fuerte generadora de una presión inferior a la atmosférica (como consecuencia de la reacción del dióxido de carbono con una base, visible con un sencillo manómetro en U, será objeto de debate entre profesor-alumno, analizándose y especulando su captura con la repercusión a nivel mundial de mejora en el calentamiento global.

CO₂ Problems and waste recycling. Research at the Institute of ferrous metallurgy

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Gudenau, H. W.

2005-04-01

Full Text Available In a short introduction tests and calculations about CO₂-ice-blocs in the deep sea, use of CO₂ for underground-coal-gasification and tertiary processes to increase oil-production by C02-flooding are shown. New activities are presented e.g. CO₂-injection into EAF combined with injection of coal, coke or directreduction-fines. After research of injection of coals, fine ores or dust into blast furnaces and other shaft furnaces activities are compared with injection of hot reducing gas generated by coal or waste gasification or top gas recycling combined with injection of fine solid fuels. Results of injection of prepared plastics (Duales System Deutschland, shredder-light-fraction from car-recycling and unburned carbon of power-station-ashes are discussed. Beside production of direct-reducediron by H₂ fluidized reactor results of the reduction behavior ore/coal or dust/coal pellets or briquettes for the use in rotary hearth or modem shaft furnaces are shown

En una breve introducción se describen las pruebas y cálculos referentes a bloques de hielo de CO₂ en el mar profundo, el uso del CO₂ para la gasificación de carbón subterráneo y procesos terciarios para aumentar la producción de aceite por medio del torrente de CO₂. Dentro de las nuevas actividades se presentan, por ejemplo, la inyección de CO₂ en el homo eléctrico de arco (HEA combinado con la inyección de carbón, coque o de finos de los procesos de reducción directa. Después de la investigación de la inyección de carbones, se comparan, por un lado, la inyección de los minerales finos o polvos en los hornos altos y otras actividades en los hornos de cuba con la inyección del gas reductor caliente generado por la gasificación del carbón o de los residuos o reciclado del gas del tragante combinado con la inyección de finos de combustibles sólidos. En el presente trabajo se discuten

CO{sub 2} capture in Mg oxides doped with Fe and Ni; Captura de CO{sub 2} en oxidos de Mg dopados con Fe y Ni

Energy Technology Data Exchange (ETDEWEB)

Sanchez S, I. F.

2016-07-01

In this work the CO{sub 2} capture-desorption characteristics in Mg oxides doped with Fe and Ni obtained by the direct oxidation of Mg-Ni and Mg-Fe mixtures are presented. Mixtures of Mg-Ni and Mg-Fe in a different composition were obtained by mechanical milling in a Spex-type mill in a controlled atmosphere of ultra high purity argon at a weight / weight ratio of 4:1 powder using methanol as a lubricating agent, for 20 h. The powders obtained by mechanical milling showed as main phase, the Mg with nanocrystalline structure. Subsequently, the mixtures of Mg-Ni and Mg-Fe were oxidized within a muffle for 10 min at 600 degrees Celsius. By means of X-ray diffraction analysis, the Mg O with nano metric grain size was identified as the main phase, which was determined by the Scherrer equation. In the Mg O doped with Ni, was identified that as the Ni amount 1 to 5% by weight dispersed in the Mg O matrix was increased, the main peak intensity of the Ni phase increased, whereas in the Mg O doped with Fe was observed by XRD, that the Fe{sub 2}O{sub 3} phase was present and by increasing the amount of Fe (1 to 5% by weight) dispersed in the crystalline phase of Mg O, the intensity of this impurity also increased. Sem-EDS analysis showed that the Ni and Fe particles are dispersed homogeneously in the Mg O matrix, and the particles are porous, forming agglomerates. Through energy dispersive spectroscopy analysis, the elemental chemical composition obtained is very close to the theoretical composition. The capture of CO{sub 2} in the Mg O-1% Ni was carried out in a Parr reactor at different conditions of pressure, temperature and reaction time. Was determined that under the pressure of 0.2 MPa at 26 degrees Celsius for 1 h of reaction, the highest CO{sub 2} capture of 7.04% by weight was obtained, while in Mg O-1% Fe the CO{sub 2} capture was 6.32% by weight. The other magnesium oxides doped in 2.5 and 5% by weight Ni and Fe showed lower CO{sub 2} capture. The different stages

Production of hydrogen using the combination of water-gas shift and carbonatation reaction of a CO{sub 2} absorbent; Produccion de hidrogeno mediante la combinacion de las reacciones de desplazamiento de agua y carbonatacion de un absorbente de CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Escobedo-Bretado, M. A.; Ponce-Pena, P. [Facultad de Ciencias Quimicas, UJED, Durango, Durango (Mexico)]. E-mail: miguel.escobedo@ujed.mx; Delgado-Vigil, M. D.; Salinas-Gutierrez, J. M.; Lopez Ortiz, A.; Collins-Martinez, V.H. [Centro de Investigacion en Materiales Avanzados, S.C., Chihuahua, Chihuahua (Mexico)

2009-09-15

The production of hydrogen by the water-gas shift (WGS) normally requires multiple catalytic reactions followed by the separation of CO{sub 2} to obtain highly pure H{sub 2}. Nevertheless, using the combination of the WGS reaction and the solid-gas reaction between CO{sub 2} and an absorbent, the production of H{sub 2} and the separation of CO{sub 2} can be accomplished in a single step AEWGS (Absorption Enhanced Water Gas Shift). This combination of reactions was studied at the laboratory scale using a quartz fixed-bed reactor. The absorbents tested were calcined dolomite (CaO*MgO) and sodium zirconate (Na{sub 2}ZrO{sub 3}) in catalyst/absorbent mixtures (cat/abs) with weight ratios of 1/1, 1/2 and 2/1, using a high-temperature catalyst from the WGS reaction, synthesized in the laboratory (Fe-Cr). All the tests used 3cm{sup 3} of cat/abs, composed of 5% CO, 15% H{sub 2}O, 10.5% He and 69.5% N{sub 2}, with a spatial velocity (SV) of 1500h-1, 600 degrees Celsius and atmospheric pressure. The catalyst presented 100% conversion of CO to CO{sub 2}, maintaining its surface area after the reaction (12 m{sup 2}/g). The results with a dry base using the cat/abs mixture of 1/2 and CaO*MgO generated 95% H{sub 2} with 5% CO-free CO{sub 2}, while with Na{sub 2}ZrO{sub 3}, the maximum concentration of H{sub 2} was 70%, with 29% CO{sub 2} and 1% of CO without reacting. The results using only CaO*MgO (as a bifunctional material) presented a maximum H{sub 2} concentration of 96% and a minimum of 4% CO{sub 2}, as well as 7% CO without reaction, which was attributed to kinetic effects. [Spanish] La produccion de hidrogeno mediante la reaccion de desplazamiento de agua WGS (Water Gas Shift), normalmente requiere de multiples reacciones cataliticas seguidas por la separacion de CO{sub 2} para obtener H{sub 2} de alta pureza. Sin embargo mediante la combinacion de la reaccion WGS con la reaccion solido-gas entre el CO{sub 2} y un absorbente provee la oportunidad de producir H2 y

Microestructura de Al2O3/TZP codopado con Fe2O3 y TiO2 fabricado por reacción (RBAO

Directory of Open Access Journals (Sweden)

Jiménez, M.

2003-02-01

Full Text Available Reaction-bonded 80 vol% Al2O3/TZP (2 mol% Y2O3-stabilized tetragonal zirconia polycrystals composites co-doped with 1 vol% Fe2O3 and 1 vol% TiO2 have been produced, and then presureless sintered (1450 ºC, 60 min or sinter-forged (20 MPa, 1200 ºC, 60 min. The resulting microstructures have been characterized using scanning electron microscopy. Both types of materials are dense, with a fine and homogeneous dual microstructure consisting of Al2O3 and TZP grains without intermediate grain boundary phases. Sinter-forged composites exhibit a very narrow pore size distribution, essentially smaller than the grain size of the alumina and zirconia phases. Co-doping promotes the sintering of alumina at lower temperatures, while still retains a fine grain size due to the presence of the dispersed zirconia phase. First results on presureless sintered RBAO materials show a fracture strength higher than in conventionally sintered and sinter-forged composites.Se han fabricado compuestos de 80% vol. Al2O3/TZP (ZrO2 estabilizada con 2% mol Y2O3 codopados con 1% vol. Fe2O3 y 1% vol. TiO2 mediante la tecnología RBAO (“Reaction Bonding of Aluminum Oxide”, que se han sinterizado libremente (1450 ºC, 60 min y bajo carga uniaxial (20 MPa, 1200 ºC, 60 min. Se ha caracterizado la microestructura mediante microscopía electrónica de barrido. Ambos materiales son densos con una microestructura homogénea formada por granos de alúmina y de circona, sin fases en juntas de grano. En el caso de la sinterización bajo carga, la distribución del tamaño de los poros es muy estrecha, y esencialmente menor que las correspondientes a los granos de Al2O3 y TZP. El codopado promueve la sinterización de la alúmina, mientras que los granos dispersos de circona inhiben su crecimiento de grano. Los ensayos preliminares de flexión en cuatro puntos realizados sobre los materiales sinterizados sin carga indican una resistencia a la fractura superior a la que presentan los

Evaluación de la susceptibilidad a la corrosión por picado del acero API 5L x42 expuesto a un ambiente con cloruros y CO2 mediante la técnica de ruido electroquímico

Directory of Open Access Journals (Sweden)

Rodríguez-Vanegas, N.

2011-10-01

Full Text Available The concentration of chloride ions and the partial pressure of CO2 play an important role in the degradation of low-carbon steels used for the construction of pipelines in oil and gas industry. In order to evaluate the susceptibility of carbon steel API 5L X42 to pitting corrosion electrochemical noise and linear polarization resistance measurements were carried out in aqueous solutions containing chloride ions and CO2. The concentration of chloride ions was varied between, 10000 and 18000 ppm, and the CO2 partial pressure between 10 psi and 18 psi. Experimental results pointed out that the formation of protective layer, consisting mainly of FeCO 3, depends on the partial pressure of CO2 in the system. Nevertheless, the stability of this layer was considerably affected by increasing the concentration of chloride ions causing that localized corrosion has taken place in some areas of the surface of API 5L X42, which were detected by electrochemical noise echnique.La concentración de iones cloruro y la presión parcial de CO2, tienen un papel importante en el proceso de degradación de los aceros de bajo carbono empleados en la construcción de líneas de transporte en industrias petroleras. Con el fin de evaluar la susceptibilidad del acero al carbono API 5L X42 a la corrosión por picado, se realizaron medidas de ruido electroquímico y resistencia a la polarización lineal en soluciones acuosas de iones cloruro con concentraciones entre 10.000 y 18.000 ppm, variando la presión parcial de CO2 entre 10 psi y 18 psi. Los resultados indican que la formación de una capa protectora, constituida principalmente por FeCO3, depende de la presión parcial de CO2 del sistema. No obstante, la estabilidad de dicha capa es afectada significativamente por el aumento de la concentración de iones cloruro, que producen fenómenos de corrosión localizada en algunas áreas de la superficie del acero API 5L X42, los cuales fueron detectados por la técnica de

Some solvent extraction studies of trivalent metal halides; Quelques etudes sur l'extraction par solvant d'halogenures de metaux trivalents; Izuchenie ehkstraktsii nekotorykh rastvoritelej iz trekhvalentnykh metallicheskikh galoidov; Algunos estudios de la extraccion mediante disolventes de haluros de metales trivalentes

Energy Technology Data Exchange (ETDEWEB)

Dietz, Jr, R J; Mendez, J; Irvine, Jr, J W [Department of Chemistry and Laboratory for Nuclear Science, Massachusetts Institute of Technology, Cambridge, MA (United States)

1962-03-15

el orden de magnitud del coeficiente varia en un intervalo de 10{sup 5}. Los autores explican los datos obtenidos sobre la base de la ionizacion del acido complejo HMX{sub 4} en estos disolventes, cuyas constantes dielectricas son relativamente elevadas. Empleando un metodo ideado por Poskanzer, han calculado la constante de ionizacion del electrolito soporte, HCl o HBr, en la fase no acuosa a partir de las variaciones que el coeficiente de extraccion experimenta en funcion de las concentraciones del metal. Las variaciones del coeficiente de extraccion con la concentracion de HX han servido para calcular las constantes de estabilidad de las especies complejas MX{sub 3} y MX{sub 4}{sup -}. Como se trata de reacciones en fase acuosa, las constantes son independientes del disolvente organico que se emplee. Para el sistema In (III)-HCl los autores obtuvieron resultados perfectamente concordantes tanto al emplear eter bis (2-cloroetilico) como nitrobenceno. Los autores no consiguieron evaluar las constantes de los complejos de cloruro y bromuro de galio porque dichos compuestos solo se forman en un intervalo de concentraciones de acido muy estrecho. Los valores del cociente (GaCl{sub 4}{sup -})/{Sigma} Ga (III) en funcion de la concentracion de HCl, calculados a partir de los datos de extraccion, concuerdan con los datos que Kraus y Nelson obtuvieron por mediciones del intercambio ionico. (author) [Russian] Metod mechenykh atomov pozvolil provesti izuchenie fiziko-khimicheskogo raspredeleniya Ga (III) i In (III) mezhdu vodnymi rastvorami HCl i HBr i organicheskimi rastvoritelyami, dvojnym ehfirom (2-khloroehtil) i nitrobenzolom. Na osnove izmerenij koehffitsientov ehkstraktsii pri kontsentratsii metalla vyshe 10{sup 10} i pri kolebanii dannogo koehffitsienta v predelakh 10{sup 5} tshchatel'no bylo razrabotano ehmpiricheskoe povedenie dannykh sistem. Rezul'taty vyrazhalis' v stepeni ionizatsii slozhnoj kisloty, HMX{sub 4}, izvestnoj v kachestve rastvoritelya s otnositel

CO2 como refrigerante: del pasado al futuro CO2 as refrigerant: from the past to future

Directory of Open Access Journals (Sweden)

Juan Manuel Belman Flores

2013-05-01

Full Text Available En años recientes y debido a la problemática que ha originado el calentamiento mundial, en el campo de la refrigeración y climatización se ha incrementado el interés por utilizar refrigerantes naturales e hidrocarburos con bajo potencial de calentamiento mundial, este es el caso de la utilización del CO2 como fluido frigorígeno que ha sido visto como una alter­nativa adecuada a los actuales refrigerantes en la comunidad científica. Hoy en día, el CO2 cada vez está retomando presencia en el campo de la refrigeración y climatización a nivel internacional, así pues, el presente trabajo tiene la finalidad de dar a conocer su potencial como refrigerante natural, las causas por las cuales este fluido fue relevado momentánea­mente por refrigerantes clorofluorocarbonados y su renacer en pleno siglo XXI. Además, se plantea su aplicación en la generación de frío en nuestro país mediante la tecnología de compresión de vapor basado en ciclo transcrítico.  In recent years, and due to problems resulting from global warming, interest has grown in the fields of refrigeration and air conditioning, specifically regarding the use of natural refrigerants and hydrocarbons with low potential for global warming. Such is the case of the use of CO2 as a cold fluid, which has been considered in the scientific community as an adequate alternative to common refrigerants. Nowadays, the use of CO2 in the areas of refrigeration and air conditioning has been recognized at international levels. Therefore, this work aims to show its potential as a natural refrigerant, the causes why this fluid was temporarily replaced by chlorofluorocarbon refrigerants, and its reappearance in the XXI century. It also proposes the use of CO2 in air conditioning in our country by using vapor compression technology, based on the transcritical cycle.

Influence of CO2 Laser Radiation on the Mechanical Properties of Portland Cement Pastes

Directory of Open Access Journals (Sweden)

González-Mota, R.

2011-03-01

Full Text Available This article presents the results of the treatment of fresh cement pastes with CO2 laser radiation (10.6μm, in order to improve its mechanical properties in addition to obtaining lower setting times than those of a natural setting (without radiation . It was observed that the CO2 laser radiation has a positive influence on the mechanical properties of cement paste, not due to the heat produced during irradiation, but due to the effect of electric field propagation on water molecules, whose are arranged around functional groups of the binder and by the effect of ration, causes a micro vibration effect, resulting in a more compact and less porous paste which has better mechanical properties compared to natural setting paste. The internal and surface temperature of the samples, the evolution of setting, Young's modulus (using ultrasonic pulse velocity and compressive strength were registered.En este artículo se presentan los resultados correspondientes al tratamiento de pastas frescas de cemento con radiación láser de CO2 (10.6µm, con el propósito de mejorar sus propiedades mecánicas además de obtener tiempos de fraguado menores a los del fraguado en forma natural (sin radiación. Se demostró que la radiación con láser de CO2 influye positivamente en las propiedades mecánicas de la pasta de cemento, no por el calentamiento producido durante la irradiación, sino por el efecto de la propagación del campo eléctrico sobre las moléculas de agua que están dispuestas alrededor de los grupos funcionales del aglutinante y que al rotar producen un efecto equivalente a micro vibraciones, dando como resultado un material más compacto, con menos poros y mejores propiedades mecánicas respecto al fraguado natural. Se registró la temperatura interna y superficial de las muestras, la evolución del fraguado, el módulo de Young y la resistencia a compresión.

Utilization of high CO2 content formation gas for steam and electricity generation; Aprovechamiento del gas de formacion con alto contenido de CO2 para generacion de vapor y electricidad

Energy Technology Data Exchange (ETDEWEB)

Villagomez, Paul; Lamino, Marcelo; Jacome, Jose; Pastor, Santiago [EcuadorTLC, Quito (Ecuador). Grupo PETROBRAS

2008-07-01

Ecuador TLC SA, as part of the PETROBRAS Group, respecting its mission to act safe, cost-effectiveness, social and environmental responsibility, currently operates an oil production project in the Ecuatorian Amazon, known as Block 18. In Block 18, the process of gas burning is response for launch approximately 10 MMSCF of the gas associated with 77% CO2 in the environment. For this reason it was built a centralized power generation plants (PGE), of 17.38 MW, taking advantage of the gas with 77% CO2 from boilers to burn it, using it as a source of heat in a combined cycle steam turbines, generating electricity. This project is environmentally efficient with reduced emissions of CO2 and as reducing fuel costs to zero. The results of CO2 reduction is a corporate goal of PETROBRAS and this project will contribute to reducing CO2 emissions by approximately 400,000 Ton over the life of the project.

Terapias alternativas con animales para niños con necesidades especiales

OpenAIRE

Cea-Chueca, Aihnoa

2014-01-01

El presente trabajo de fin de grado consiste en la realización de un análisis y descripción de la literatura acerca de las distintas terapias animales, destinadas a niños con necesidades especiales: cómo y por qué surgieron, en qué consisten las terapias, cómo podemos utilizarlas, etc. Las terapias alternativas con animales se conocen como una alternativa terapéutica, donde se utiliza a un animal como co-terapeuta para poder desarrollar diferentes capacidades de los niños con necesidades espe...

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

CERN Document Server

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

2016-01-01

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

An Overview of CO{sub 2} capture technologies. What are the challenges ahead?

Energy Technology Data Exchange (ETDEWEB)

Santos, Stanley (IEA Greenhouse Gas R& amp; D Programme)

2008-07-15

In this paper it is described what the program of R&D of the International Energy Agency consists of, for the reduction of greenhouse effect gasses. Some of the factors that have impelled the policy of the development of technologies for the CO{sub 2} capture are synthesized. Also an overview is given of the 3 main technologies for the capture and storage of CO{sub 2} that are the capture post-combustion, the capture oxy-combustion and the capture pre-combustion; finally several aspects related to the capture and sequestration of CO{sub 2} are mentioned. [Spanish] En esta ponencia se describe en que consiste el programa de I&D para la reduccion de gases de efecto invernadero de la Agencia Internacional de Energia. Se sintetizan algunos de los factores que han impulsado a la politica del desarrollo de tecnologias para la captura de CO{sub 2}. Tambien se da un panorama de las 3 principales tecnologias para la captura y almacenamiento de CO{sub 2} que son la captura post-combustion, la captura oxi-combustion y la captura pre-combustion; finalmente se mencionan varios aspectos relacionados con la captura y secuestro de CO{sub 2}.

Esporotricosis cutánea diseminada con compromiso articular en una mujer con diabetes tipo 2

Directory of Open Access Journals (Sweden)

Sendy Solorzano

Full Text Available La esporotricosis diseminada es una presentación infrecuente de esta micosis. Aunque ha sido descrita en sujetos inmunocompetentes, con frecuencia existe compromiso de la inmunidad mediada por células T. Reportamos el caso de una mujer con diabetes tipo 2 no controlada que desarrolló esporotricosis cutánea diseminada. El curso de la enfermedad presentó varias complicaciones que incluyeron hepatitis secundaria a itraconazol y artritis de la rodilla con cultivo positivo para Sporothrix schenckii durante el tratamiento con solución saturada de ioduro de potasio. La discusión del caso incluye aspectos de la patogénesis de la esporotricosis diseminada y el manejo de la infección y sus complicaciones.

Utilización de células madre adiposas en procesos de regeneración ósea guiada en defectos de tamaño crítico de la cortical vestibular

OpenAIRE

Alvira González, Joaquín

2017-01-01

[spa] La colocación de implantes se ve limitada en ocasiones por defectos del reborde alveolar debidos principalmente a extracciones traumáticas, procesos infecciosos de los dientes o bien a la reabsorción ósea que tiene lugar tras su extracción. La asociación de los procedimientos de regeneración ósea guiada con técnicas de ingeniería tisular que utilizan células madre en combinación con proteínas que contienen moléculas bioactivas, tiene como objetivo regenerar los defectos óseos con u...

Rechargeable Al-CO2 Batteries for Reversible Utilization of CO2.

Science.gov (United States)

Ma, Wenqing; Liu, Xizheng; Li, Chao; Yin, Huiming; Xi, Wei; Liu, Ruirui; He, Guang; Zhao, Xian; Luo, Jun; Ding, Yi

2018-05-21

The excessive emission of CO 2 and the energy crisis are two major issues facing humanity. Thus, the electrochemical reduction of CO 2 and its utilization in metal-CO 2 batteries have attracted wide attention because the batteries can simultaneously accelerate CO 2 fixation/utilization and energy storage/release. Here, rechargeable Al-CO 2 batteries are proposed and realized, which use chemically stable Al as the anode. The batteries display small discharge/charge voltage gaps down to 0.091 V and high energy efficiencies up to 87.7%, indicating an efficient battery performance. Their chemical reaction mechanism to produce the performance is revealed to be 4Al + 9CO 2 ↔ 2Al 2 (CO 3 ) 3 + 3C, by which CO 2 is reversibly utilized. These batteries are envisaged to effectively and safely serve as a potential CO 2 fixation/utilization strategy with stable Al. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Brine/CO2 Interfacial Properties and Effects on CO2 Storage in Deep Saline Aquifers Propriétés interfaciales saumure/CO2 et effets sur le stockage du CO2 dans des aquifères salins profonds

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Chalbaud C.

2010-05-01

Full Text Available It has been long recognized that interfacial interactions (interfacial tension, wettability, capillarity and interfacial mass transfer govern fluid distribution and behaviour in porous media. Therefore the interfacial interactions between CO2, brine and reservoir oil and/or gas have an important influence on the effectiveness of any CO2 storage operation. There is a lack of experimental data related to interfacial properties for all the geological storage options (oil & gas reservoirs, coalbeds, deep saline aquifers. In the case of deep saline aquifers, there is a gap in data and knowledge of brine-CO2 interfacial properties at storage conditions. More specifically, experimental interfacial tension values and experimental tests in porous media are necessary to better understand the wettability evolution as a function of thermodynamic conditions and it’s effects on fluid flow in the porous media. In this paper, a complete set of experimental values of brine-CO2 Interfaciale Tension (IFT at pressure, temperature and salt concentration conditions representative of those of a CO2 storage operation. A correlation is derived from experimental data published in a companion paper [Chalbaud C., Robin M., Lombard J.-M., Egermann P., Bertin H. (2009 Interfacial Tension Measurements and Wettability Evaluation for Geological CO2 Storage, Adv. Water Resour. 32, 1, 1-109] to model IFT values. This paper pays particular attention to coreflooding experiments showing that the CO2 partially wets the surface in a Intermediate-Wet (IW or Oil-Wet (OW limestone rock. This wetting behavior of CO2 is coherent with observations at the pore scale in glass micromodels and presents a negative impact on the storage capacity of a given site. Il est admis depuis longtemps que les propriétés interfaciales (tension interfaciale, mouillabilité, capillarité et transfert de masse régissent la distribution et le comportement des fluides au sein des milieux poreux. Par cons

Detección de compuestos presentes en una especie de Amanita micoparasitada, colectada en el corregimiento de Santa Elena (Antioquia, Colombia)

OpenAIRE

Aura Helena Corredor Q.; Liliana Londoño

2005-01-01

Para este trabajo se seleccionó una especie de Amanita, parasitada probablemente por un Hyphomycete, que presenta un crecimiento anormal y sobre la cual no existen trabajos previos. Inicialmente se hicieron extracciones etanólicas del material fresco en frío y con soxhlet. Se realizó una marcha fotoquímica preliminar del extracto obtenido y se detectaron coumarinas, alcaloides, fenoles y glicósidos cardiotónicos. Posteriormente se estandarizó que la cromatografía de capa fina con el sistem...

CO2 sequestration

International Nuclear Information System (INIS)

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

2009-01-01

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

Evaluation of Cross-Section Data from Threshold to 40 MeV for some Neutron Reactions Important for Fusion Dosimetry Applications. Part 2 Evaluation of the Excitation Functions for the 59Co(n,3n)57Co, 89Y(n,2n)88Y, 93Nb(n,2n)92mNb, 169Tm(n,2n)168Tm and 209Bi(n,3n)207Bi Reactions

International Nuclear Information System (INIS)

Zolotarev, K.I.

2010-11-01

Evaluations of cross sections and their associated covariance matrices have been carried out for five dosimetry reactions: excitation functions were re-evaluated for the 89 Y(n,2n) 88 Y, 93 Nb(n,2n) 92 mNb and 169 Tm(n,2n) 168 Tm reactions over the neutron energy range from threshold up to 40 MeV; excitation functions were re-evaluated for the 59 Co(n,3n) 57 Co and 209 Bi(n,3n) 207 Bi reactions over the neutron energy range from threshold to 85 and 45 MeV, respectively. Uncertainties in the cross sections for all of those reactions were also derived in the form of relative covariance matrices. Benchmark calculations performed for 235 U thermal fission and 252 Cf spontaneous fission neutron spectra show that the integral cross sections calculated from the newly evaluated excitation functions exhibit improved agreement with related experimental data when compared with the equivalent data from the IRDF-2002 library. (author)

A novel ECL biosensor for the detection of concanavalin A based on glucose functionalized NiCo2S4 nanoparticles-grown on carboxylic graphene as quenching probe.

Science.gov (United States)

Li, Xiaojian; Wang, Yaoguang; Shi, Li; Ma, Hongmin; Zhang, Yong; Du, Bin; Wu, Dan; Wei, Qin

2017-10-15

An electrochemiluminescence (ECL) biosensor was developed for detection of Concanavalin A (Con A). Chitosan/Ru(bpy) 3 2+ /silica/Fe 3 O 4 nanomaterials (CRuSi-Fe 3 O 4 ) were synthesized through W/O microemulsion route. The added Fe 3 O 4 nanoparticles can simplify the prepared process and enhance the conductivity of nanomaterials which can increase the ECL intensity of luminophor CRuSi-Fe 3 O 4 . In addition, the layered structure of CRuSi-Fe 3 O 4 can immobilize lots of Con A using glutaraldehyde as the coupling agent which can improve the sensitivity of the biosensor. Then the quenching probe glucose functionalized NiCo 2 S 4 nanoparticles-grown on carboxylic graphene (NiCo 2 S 4 -COOH-rGO@Glu) was anchored on the modified-electrode via the specific carbohydrate-Con A interaction. Here, NiCo 2 S 4 was used to quench the ECL of CRuSi-Fe 3 O 4 , graphene was used to grow NiCo 2 S 4 nanoparticles as carrier materials and glucose was served as the recognition element for bounding Con A. Therefore, a desirable quenching ECL signal was measured with S 2 O 8 2- as the coreactant of CRuSi-Fe 3 O 4 . Under the optimization of determination conditions, a linear response range for Con A from 0.5pgmL -1 to 100ngmL -1 was obtained, and the detection limit was calculated to be 0.18pgmL -1 (S/N=3). Copyright © 2017 Elsevier B.V. All rights reserved.

FRECUENCIA DE LAS CO-MORBILIDADES PSIQUIÁTRICAS DEL EJE I EN LOS PACIENTES CON DIAGNÓSTICO DE TRASTORNO POR ESTRÉS POSTRAUMÁTICO

OpenAIRE

SERRANO C., ADRIANA M.; ORTIZ J., DANILO A.; BOHÓRQUEZ P., ADRIANA P.

2009-01-01

Por medio de un estudio observacional descriptivo de corte transversal realizado en pacientes con diagnóstico de Trastorno por Estrés Postraumático (TEPT) con antecedente de exposición a combates, con grado militar de profesional, suboficial u oficial, hospitalizados por el Servicio de Psiquiatría del Hospital Militar Central de Bogotá entre enero y junio de 2008, se describe la presentación clínica de las co-morbilidades psiquiátricas asociadas al TEPT. Se detectó agorafobia en el 45,5% de l...

Extracción con CO2 supercrítico de oleorresina y otras fracciones de pimentón dulce y picante

Directory of Open Access Journals (Sweden)

Fernández-Trujillo, J. Pablo

2008-03-01

, colorants or deodorized extracts, capsaicinoids extract for food or other uses, as well as oleoresins enrichedin zeaxanthines that it is possible to obtain.Se revisan las condiciones para la extracción de pimiento o pimentón mediante CO2 supercrítico (ESCO2, la cual depende del pretratamiento de las muestras (trituración, peletizado,etc., las condiciones estáticas o dinámicas, presión,temperatura, tiempo de extracción, cantidad y densidaddel CO2, etapas de extracción, o presencia de cosolventes. Las condiciones aconsejables según la literatura son prepeletizary extraer a 40 °C en dos etapas: 13,8-15 MPa paraaromas y β-caroteno, seguido de 40 MPa para otros carotenoides (capsorrubeno, capsanteno, zeaxanteno, y β-criptoxanteno.En general la ESCO2 extrae mejor capsaicinoidesy tocoferoles que xantofilas rojas. Para extraer capsaicinoidesse han utilizado 32-40 MPa y 40-55 °C, y para extraerpigmentos clorofílicos en ciertos estados de madurez y variedades 36 MPa y 45 °C. Para tocoferoles 20 MPa y 55 °C ó las condiciones anteriores también se han aconsejado. Según la materia prima y condiciones de extracción óptimas, los rendimientos son muy variables: 5,2-17,4% (totales, 2-3% carotenoides totales, 0,7–8,6% de capsaicinoides en ORPs picantes, y 370-400 μg • g-1 de tocoferoles, (especialmente el isómero α-tocoferol. El porcentaje de recuperación de estos compuestos previa fraccionamiento y optimización de materia prima y proceso de extracción es del 90-100%.Como cosolventes para extraer capsaicinoides se ha utilizado etanol, agua y con menores resultados ácido acético u otros, y para β-caroteno 2,2-dimetoxipropano ó ESCO2 y adsorción mediante silica gel. Los principales peligros y puntos de control crítico del proceso son los derivados de la altapresión del CO2. Lo son también la homogeneidad de distribución del soluto según pretratamientos previos, la variabilidad de los resultados en composición de los pigmentos

Estudio experimental de la adhesión interfacial del sistema Sn/Pb - Al2O3 asistido con láser

OpenAIRE

Guerrero, A; Puerta, J; Lira, J

2006-01-01

En el presente trabajo se propuso y construyó un diseño de cámara de experimentación que permitió realizar diferentes mediciones del ángulo de contacto. El substrato cerámico (Sn/Pb - Al2O3) fue previamente tratado con un láser de CO2 y sobre el mismo se depositó una aleación de Estaño-Plomo fundido empleando el método de la gota en reposo en alto vacío. Estas mediciones experimentales se realizaron con el fin de conocer el comportamiento físico-químico de la mojabilidad del sistema metal-cer...

Modelo para el cálculo simplificado de emisiones de CO2 de las viviendas en Europa

OpenAIRE

Claro Ponce, José Carlos

2011-01-01

La finalidad del trabajo es poder obtener una herramienta que permita a un ciudadano autoevaluar, de una forma estimativa, su vivienda desde el punto de vista de las emisiones de CO2 que produzca con el uso de la misma. Para ello, se crea una batería de preguntas, partiendo de una encuesta inicial, la cual se analiza y adapta a un vocabulario no técnico, y posteriormente, se traducen las respuestas a emisiones de CO2.

Connecting CO2. Feasibility study CO2 network Southwest Netherlands; Connecting CO2. Haalbaarheidsstudie CO2-netwerk Zuidwest-Nederland

Energy Technology Data Exchange (ETDEWEB)

Rutten, M.

2009-06-10

An overview is given of supply and demand of CO2 in the region Southwest Netherlands and the regions Antwerp and Gent in Belgium. Also attention is paid to possible connections between these regions [Dutch] Een inventarisatie wordt gegeven van vraag en aanbod van CO2 in de regio Zuidwest- Nederland en de regios Antwerpen en Gent in Belgie. Ook worden mogelijke koppelingen tussen de regios besproken.

Well technologies for CO2 geological storage: CO2-resistant cement

International Nuclear Information System (INIS)

Barlet-Gouedard, V.; Rimmele, G.; Porcherie, O.; Goffe, B.

2007-01-01

Storing carbon dioxide (CO 2 ) underground is considered the most effective way for long-term safe and low-cost CO 2 sequestration. This recent application requires long-term well-bore integrity. A CO 2 leakage through the annulus may occur much more rapidly than geologic leakage through the formation rock, leading to economic loss, reduction of CO 2 storage efficiency, and potential compromise of the field for storage. The possibility of such leaks raises considerable concern about the long-term well-bore isolation and the durability of hydrated cement that is used to isolate the annulus across the producing/injection intervals in CO 2 -storage wells. We propose a new experimental procedure and methodology to study reactivity of CO 2 -Water-Cement systems in simulating the interaction of the set cement with injected supercritical CO 2 under downhole conditions. The conditions of experiments are 90 deg. C under 280 bars. The evolution of mechanical, physical and chemical properties of Portland cement with time is studied up to 6 months. The results are compared to equivalent studies on a new CO 2 -resistant material; the comparison shows significant promise for this new material. (authors)

Caracterización y estudio de las propiedades térmicas de una poliamida impar (nylon 3

Directory of Open Access Journals (Sweden)

Ángel T. Pérez Rodríguez

2010-01-01

Full Text Available El trabajo se centró en la caracterización y el estudio de las propiedades térmicas de una poliamida impar, el nylon 3, debido a su potencial aplicación como material con propiedades eléctricas activas. La poli-B-alanina o nylon 3 (-NH -CH2 -CH2 -CO-n, es un polímero cristalino que se caracteriza por tener una elevada densidad de grupos amida y, por tanto, de puentes de hidrógeno. Su principal atractivo en el campo de la ferroelectricidad está motivado por el momento dipolar asociado a los grupos amida. El nylon 3 utilizado fue obtenido por transferencia de hidrógeno a partir de acrilamida. Las fracciones soluble e insoluble en agua se han separado por extracciones repetidas con agua caliente. Para nuestro trabajo se usó exclusivamente la fracción insoluble. La caracterización se llevó a cabo mediante viscosimetría capilar y espectroscopía IR y RMN. Para el análisis térmico se utilizaron la calorimetría diferencial de barrido y el análisis termogravimétrico en atmósfera inerte. Nuestro objetivo ha sido estudiar las condiciones necesarias para obtener películas manipulables que permitieran la evaluación de la respuesta ferroeléctrica. Como resultados cabe destacar que los filmes obtenidos son poco manipulables debido a la baja flexibilidad que poseen.

Assimilació i gestió del carboni en plantes de creixement lent sotmeses a CO2 elevat

OpenAIRE

Pardo Evangelista, Antoni

2006-01-01

En l'actualitat, la concentració atmosfèrica de CO2 està augmentant de forma important a conseqüència de les emissions antropogèniques. Per tant, resulta essencial conèixer quina serà la resposta dels vegetals al CO2 elevat, especialment a llarg termini. Si bé s'han realitzat molts estudis que avaluen l'impacte del CO2 elevat sobre les plantes, la gran majoria s'han dut a terme en espècies de creixement ràpid. Per això, és una incògnita quin serà el comportament de les plantes de creixement l...

CO{sub 2} separation

Energy Technology Data Exchange (ETDEWEB)

Hakuta, Toshikatu [National Inst. of Materials and Chemical Research, Ibaraki (Japan)

1993-12-31

The climate change induced by CO{sub 2} and other greenhouse gases is probably the most serious environmental threat that mankind has ever experienced. Nowadays fossil fuels occupy the majority of the world commercial energy supply. Most nations will be dependent on fossil fuels even in the first half of the next century. Around 30 % of CO{sub 2} in the world is emitted from thermal power plants. Recovering CO{sub 2} from energy conversion processes and storing it outside the atmosphere is a promising option for the mitigation of global warming. CO{sub 2} fixation and storage include CO{sub 2} disposal into oceans and underground, and utilization of CO{sub 2}. CO{sub 2} separation process will be used in any CO{sub 2} storage system, and is estimated to consume almost half the energy of the total system. Research and development of highly efficient CO{sub 2} separation process is most important from the viewpoint of practical application of CO{sub 2} fixation system.

Extracción de Sustancias Hidrofóbicas de Andisols Repelentes al Agua del Oriente Antioqueño, con Solventes Polares

Directory of Open Access Journals (Sweden)

Jaramillo J. Daniel F.

1997-12-01

Full Text Available Muestras de Andisols repelentes al agua fueron sometidas a extracciones con mezclas de solventes orgánicos de diferentes polaridaddes; los lavados con mezclas de polaridades 5 y 6 removieron completamente la hidrofobicidad del suelo, sin importar el orden en el cual se hicieron. Del comportamiento del suelo frente a las secuencias de extracción se pudo concluir que los compuestos orgánicos del suelo se acumulan en él en forma de capas, las cuales pueden presentar alternancia de compuestos hidrofóbicos con compuestos hidrofílicos; además, los compuestos más hidrofóbicos son removidos por las mezclas de solventes de mayor grado de polaridad. Se plantea la existencia de dos tipos básicos de hidrofobicidad en los compuestos orgánicos del suelo: una "hidrofobicidad posible ": la que se manifiesta cuando la arena desarrolla repelencia al agua al recibir los extractos y que detecta la presencia de compuestos hidrofóbicos en ellos. La otra, la "hidrofobicidad activa": la que se produce en suelos humectables cuando reciben extractos hidrofóbicos y muestra, no sólo la presencia de los compuestos hidrofóbicos en ellos, sino también que se están presentando las condiciones para que ellos interactúen con los componentes originales del suelo y se desarrolle la hidrofobicidad en el mismo. Extractos obtenidos por lavado de raíces finas y acículas recién caídas de Pinus patula, con mezclas de polaridades 5 y 6, no indugeron repelencia apreciable al agua, ni en suelos humectables ni en arena lavada, cuando se aplicaron en concentraciones menores de 0.4%, lo que sugiere que estos materiales deben tener algún grado de transformación para que le impriman al suelo la hidrofobicidad; además, las raíces tienen una mayor hidrofobicidad potencial que las acículas.

Comparison between insufflation with air or carbon dioxide during the colonoscopy in sedated patients with propofol Comparación entre la insuflación con aire ambiente o con dióxido de carbono durante la colonoscopia en pacientes sedados con propofol

Directory of Open Access Journals (Sweden)

Pilar Díez-Redondo

2012-08-01

Full Text Available Objectives: compare the intensity of pain experienced after colonoscopy with air or with CO2 and evaluate the safety of CO2 in colonoscopies performed with moderate/deep sedation. Materials and methods: individuals undergoing ambulatory colonoscopy without exclusion criteria (severe respiratory disease, morbid obesity were randomized in air or CO2 group. We recorded different variables prior to, during and upon completion of the colonoscopy, performing monitoring using pulse oximetry and capnography. Each patient rated, using a visual numeric scale, the intensity of post-colonoscopy pain at different moments. Results: 141 individuals in the air group (sex M/F 63/78, age 24-83 and 129 in the CO2 group (sex M/F 59/70, age 24-82. No significant differences existed in the recorded variables in both groups except for the greater number of explorations performed by an endoscopist in training (TE in the air group compared to those by a more experienced endoscopist (SE. CO2 in expired air, episodes of oxygen desaturation and of apnoea and dose of propofol, of midazolam were similar in both groups. No episodes of hypercapnea or any complication requiring cardiopulmonary resuscitation measures were recorded. The pain in the air group was significantly higher at 15 minutes and at 1, 3 and 6 hours after the endoscopy, equalising at 24 hours. After multivariant adjustment for type of doctor (TE vs. SE the differences observed in pain intensity for each group were maintained. Conclusions: a the use of CO2 in colonoscopy causes significantly less pain in the first 6 hours after the procedure; b its use in patients with moderate/deep sedation is safe; and c performance of the endoscopic technique is not modified, nor are times reduced.Objetivos: comparar la intensidad del dolor experimentado tras una colonoscopia con aire ambiente o con dióxido de carbono (CO2 y evaluar la seguridad del CO2 en pacientes con sedación moderada o profunda. Materiales y m

Equilibration of metabolic CO2 with preformed CO2 and bicarbonate

International Nuclear Information System (INIS)

Hems, R.; Saez, G.T.

1983-01-01

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

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

Science.gov (United States)

Fu, Wen Gan

2018-05-02

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

Estudio observacional prospectivo con insulina detemir en pacientes con diabetes mellitus tipo 2 mal controlados que inician por primer vez tratamiento con insulina (estudio SOLVE

Directory of Open Access Journals (Sweden)

Domingo Orozco-Beltrán

2016-02-01

Conclusiones: En esta cohorte de pacientes con diabetes mellitus tipo 2 recientemente insulinizados, la insulina detemir (una vez al día mejoró el control glucémico, con baja incidencia de hipoglucemia y una reducción significativa del peso.

Modelización de las transformaciones de fase en el proceso de endurecimiento de aceros con láser de CO₂

Directory of Open Access Journals (Sweden)

Amado, J. M.

2004-10-01

utilizando la ley de Johnson-Mehl y Avrami. En el enfriamiento se utilizan los diagramas TTT a la manera que se hacía con los IT en el calentamiento. Se valida el modelo utilizando una serie de datos experimentales donde se muestran, de un lado, el mapa de durezas producto del tratamiento de una pieza plana de AISI 1045 con láser de CO₂ y, de otro, el mapa de concentración de martensita obtenida a partir del modelado de ese mismo proceso. La coincidencia entre ambos mapas permite una primera validación del modelo presentado.

Análisis de factores relacionados con hipercapnia crónica en la distrofia miotónica

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Patricia K. Aruj

2013-12-01

Full Text Available La distrofia miotónica (DM es la distrofia muscular más común en adultos. Diversos factores pueden explicar la retención crónica de CO2. La selección de pacientes, diferentes estadios evolutivos y formas de evaluación, pueden explicar los resultados disímiles al respecto. Nuestros objetivos fueron caracterizar la función respiratoria y analizar los factores relacionados con la retención crónica de CO2 en la DM. Se incluyeron 27 pacientes ambulatorios consecutivos, estables clínicamente y se los agrupó como normocápnicos e hipercápnicos (PaCO2 ≥ 43 mm Hg. Se determinaron capacidad vital forzada (FVC, presiones estáticas máximas, tiempo de apnea voluntaria, escala de Epworth y gases arteriales. La quimiosensibilidad al CO2 se evaluó mediante la reinhalación de CO2 (método de Read. La pendiente ∆P0.1/∆PCO2 expresa la quimiosensibilidad al CO2. El 59.3% tenían hipercapnia. La FVC y la fuerza muscular respiratoria fueron normales o mostraron disminución leve a moderada, sin diferencias significativas en ambos grupos. La inadecuada respuesta al CO2 (pendientes ∆P0.1/∆PCO2 bajas (< 0.1 cmH2O/mm Hg o planas se asoció con hipercapnia (p < 0.005 y ésta significó un riesgo 11.6 veces mayor de inadecuada respuesta al CO2. El grupo con pendiente ∆P0.1/∆PCO2 baja-plana mostró mayor PaCO2 (p = 0.0017 y tiempo de apnea voluntaria más prolongado (p = 0.002. Concluimos que, en nuestros pacientes con DM, la hipercapnia crónica se asoció a la presencia de anomalías del control central de la respiración. Estos resultados permiten explicar los informes previos que describen la llamativa ocurrencia de insuficiencia respiratoria postoperatoria y las dificultades en el proceso de desvinculación de asistencia ventilatoria mecánica en estos pacientes.

Graphene oxide doped ionic liquid ultrathin composite membranes for efficient CO2 capture

KAUST Repository

Karunakaran, Madhavan

2016-11-28

Advanced membrane systems with high flux and sufficient selectivity are required for industrial gas separation processes. In order to achieve high flux and high selectivity, the membrane material should be as thin as possible and it should have selective sieving channels and long term stability. This could be achieved by designing a three component material consisting of a blend of an ionic liquid and graphene oxide covered by a highly permeable low selective polymeric coating. By using a simple dip coating technique, we prepared high flux and CO selective ultrathin graphene oxide (GO)/ionic liquid membranes on a porous ultrafiltration support. The ultrathin composite membranes derived from GO/ionic liquid complex displays remarkable combinations of permeability (CO flux: 37 GPU) and selectivity (CO/N selectivity: 130) that surpass the upper bound of ionic liquid membranes for CO/N separation. Moreover, the membranes were stable when tested for 120 hours.

CO2 blood test

Science.gov (United States)

Bicarbonate test; HCO3-; Carbon dioxide test; TCO2; Total CO2; CO2 test - serum; Acidosis - CO2; Alkalosis - CO2 ... Many medicines can interfere with blood test results. Your health ... need to stop taking any medicines before you have this test. DO ...

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

International Nuclear Information System (INIS)

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

2015-01-01

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

A first principles calculations of structural, electronic, magnetic and dynamical properties of mononitrides FeN and CoN

International Nuclear Information System (INIS)

Soni, Himadri R.; Mankad, Venu; Gupta, Sanjeev K.; Jha, Prafulla K.

2012-01-01

Highlights: ► We present spin dependent bandstructure, structural and magnetic moment of FeN/CoN. ► The PDC, PHDOS, spin effect on phonons suggests ZB is preferred at ambient pressure. ► Spin calculation offers an opportunity to understand the role of spin on phonons. - Abstract: Using first principles density functional theoretical calculations, the present paper reports a systematic nonspin and spin polarized total energy calculations of the lattice dynamical and a number of other properties such as band structure, structural and magnetic moment of two mononitrides FeN and CoN. The phonon dispersion curves and phonon density of states in the case of FeN and CoN have been determined for the first time and discussed. The structural and dynamical calculations suggest that the zinc blende structure is preferred at ambient pressure for both compounds. The rocksalt FeN has a nonzero magnetic moment while for FeN in zinc blende phase, it is either zero or very small. The zinc blende phase for both compounds is nonmagnetic. The spin calculation offers an intensive opportunity to understand the role of spin on the phonon properties of two mononitrides. Majority of the modes are sensitive to the effect of spin due to the modification of lattice constant. In this work we reveal that spin modifies the interionic interactions and local structure and leads to a flexible lattice which can be used for the functional materials design.

Hydrogen purification by selective methanation of CO in CO/CO2/H2

DEFF Research Database (Denmark)

Andersen, Anne Mette; Johannessen, Tue; Livbjerg, Hans

down through the reactor and inside the catalyst pellets/particles. The small particles, which have a rather high effectiveness factor with respect to methanation of CO, have a high CO selectivity, whereas the larger pellets have very low selectivity even at high CO inlet concentrations. Negative...... of reaction kinetics and pore diffusion is crucial for interpreting the experimental data. We have found that the selectivity decreases by increasing the reactor temperature or catalyst particle size and when the CO inlet concentration is reduced. As a result, the selectivity drops significantly...... in an integral reactor operating at high CO-conversion. The lower limit of CO concentration in the outlet is determined by the quasi-equilibrium between CO removal and CO production from CO2....

TECHNOLOGICAL INNOVATIONS ON UNDERGROUND COAL GASIFICATION AND CO2 SEQUESTRATION

Directory of Open Access Journals (Sweden)

CARLOS DINIS DA GAMA

2010-01-01

Full Text Available Se describen las principales contribuciones al desarrollo tecnológico del proceso de gasificación subterránea del carbón (G.S.C. y complementariamente la posibilidad de secuestración del CO2 en el medio ambiente subterráneo. Se busca explicar por que razones existen actualmente en el mundo muy pocas plantas industriales de G.S.C. que produzcan regularmente combustibles gaseosos oriundos de la combustión del carbón "in situ", a pesar de las ventajas de protección ambiental que resultan de este proceso. Un breve listado de los proyectos en curso es incluido. La posibilidad del almacenamiento subterráneo del CO2 con o sin simultaneidad respecto a la G.S.C. es analizada, destacando las principales dificultades de aplicación de esta técnica y los riesgos asociados a las soluciones integradas, que necesitan soluciones de innovación.

Retrospective of CO{sub 2} emissions of the Mexican industrial sector; Retrospectiva de emisiones de CO{sub 2} del sector industrial mexicano

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Domingo; Martinez, Manuel [Universidad Nacional Autonoma de Mexico (UNAM), Mexico, D.F. (Mexico)

2006-11-15

emisiones de CO{sub 2} aumentaron 230%. Las ramas industriales que han mostrado cambios significativos en la emision de CO{sub 2} son Construccion, Aguas envasadas, Hule, Cemento, Cerveza y malta y Quimica. Para evaluar los efectos de la Actividad, Estructura, Intensidad Energetica, Mezcla de combustibles de uso final y Mezcla de combustibles empleados en la generacion de electricidad se utiliza el modelo de descomposicion de CO{sub 2} fundamentado en el indice de Laspeyres. Los efectos calculados muestran que el principal aumento de bioxido de carbono total del SIM es referido a la Actividad con una tasa media de crecimiento anual (TMCA) de 4.32%; mientras que el efecto que mitiga mas la emision de CO{sub 2} es el descrito por la Intensidad energetica y equivale a una TMCA de -0.85%.

CO2-Switchable Membranes Prepared by Immobilization of CO2-Breathing Microgels.

Science.gov (United States)

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

2017-12-20

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

TG-FTIR measurement of CO2-H2O co-adsorption for CO2 air capture sorbent screening

NARCIS (Netherlands)

Smal, I.M.; Yu, Qian; Veneman, Rens; Fränzel-Luiten, B.; Brilman, Derk Willem Frederik

2014-01-01

Capturing atmospheric CO2 using solid sorbents is gaining interest. As ambient air normally contains much more (up to 100 times) water than CO2, a selective sorbent is desirable as co-adsorption will most likely occur. In this study, a convenient method based on an TG-FTIR analysis system is

CO2 electroreduction performance of a single transition metal atom supported on porphyrin-like graphene: a computational study.

Science.gov (United States)

Wang, Zhongxu; Zhao, Jingxiang; Cai, Qinghai

2017-08-30

Searching for low-cost, efficient, and stable electrocatalysts for CO 2 electroreduction (CO 2 ER) reactions is highly desirable for the reduction of CO 2 emission and its conversion into useful products, but remains a great challenge. In this work, single transition metal atoms supported on porphyrin-like graphene catalysts, i.e., TMN 4 /graphene, acting as electrocatalysts for CO 2 reduction were explored by means of comprehensive density functional theory (DFT) computations. Our results revealed that these anchored TM atoms possess high stability due to their strong hybridization with the unsaturated N atoms of the substrate and function as the active sites. On the basis of the calculated adsorption strength of CO 2 ER intermediates, we have identified that single Co, Rh, and Ir atoms exhibit superior catalytic activity towards CO 2 reduction. In particular, CH 3 OH is the preferred product of CO 2 ER on the CoN 4 /graphene catalyst with an overpotential of 0.59 V, while the RhN 4 /graphene and IrN 4 /graphene catalysts prefer to reduce CO 2 to CH 2 O with an overpotential of 0.35 and 0.29 V, respectively. Our work may open a new avenue for the development of catalytic materials with high efficiency for CO 2 electroreduction.

Atmospheric inversion of the surface CO2 flux with 13CO2 constraint

Science.gov (United States)

Chen, J. M.; Mo, G.; Deng, F.

2013-10-01

Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using the 13CO2/CO2 flux ratio modeled with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and respiration and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. For the 2002-2004 period, the 13CO2 constraint on the inversion increases the total land carbon sink from 3.40 to 3.70 Pg C yr-1 and decreases the total oceanic carbon sink from 1.48 to 1.12 Pg C yr-1. The largest changes occur in tropical areas: a considerable decrease in the carbon source in the Amazon forest, and this decrease is mostly compensated by increases in the ocean region immediately west of the Amazon and the southeast Asian land region. Our further investigation through different treatments of the 13CO2/CO2 flux ratio used in the inversion suggests that variable spatial distributions of the 13CO2 isotopic discrimination rate simulated by the models over land and ocean have considerable impacts on the spatial distribution of the inverted CO2 flux over land and the inversion results are not sensitive to errors in the estimated disequilibria over land and ocean.

Surface and bulk modifications of 1.5 mole % Sr/La{sub 2}O{sub 3} catalyst with different Co, Ni, and Cu amounts

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Cortes, Sergio; Fontal, Bernardo [Universidad de los Andes, Merida (Venezuela); Moronta, Delfin [Universidad Central de Venezuela, Caracas (Venezuela)

2001-08-01

The effects of Co, Ni and Cu oxide content on the surface and bulk of the 1.5 mole % Sr/La{sub 2}O{sub 3} catalysts were studied. Series of M/Sr-La catalysts (MCo, Ni, Cu) were prepared by successive immersion impregnation. The solids were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), temperature-programmed reduction (TPR), electron paramagnetic resonance (EPR), specific surface area measurements (BET) and thermogravimetric analysis (TGA). The Sr/La{sub 2}O{sub 3} modified with different Co, Ni, and Cu loading shows a strong metal oxide interaction with La{sub 2}O{sub 3}. This probably begin over anionic vacancies or structure defects favoring LaSrMO{sub x} solid solution formation with island-like structures according to a Volmer-Weber growth. It is proposed that the growth mode of La-Co, La-Ni and La-Cu stoichiometric phases occur from solid solutions. The formation of only a La-M single phase, probably non-stoichiometric, increases the material porosity while different phases favor the agglomeration or sintering of the particles. [Spanish] En este trabajo se estudia el efecto de la cantidad de cobalto, niquel y cobre sobre las estructuras superficial y masica del sistema 1.5% molar Sr/La{sub 2}O{sub 3}. Los catalizadores M/Sr-La (M = Co, Ni, Cu) fueron preparados por el metodo de impregnacion con exceso de solucion. Los solidos se caracterizaron por difraccion de rayos-X, espectroscopia infrarroja con transformada de Fourier, reduccion a temperatura programada, resonancia paramagnetica del electron, medidas del area superficial especifica por el metodo de BET y analisis termogravimetrico. El catalizador Sr/La{sub 2}O{sub 3} modificado con diferentes cantidades de Co, Ni y Cu muestra una interaccion fuerte con el oxido del metal de transicion, probablemente sobre las vacancias anionicas o defectos estructurales que favorecen la formacion de la solucion solida LaSrMox en forma de isla, segun el mecanismo de crecimiento de fase de Volmer

Studies on CO2 removal and reduction. CO2 taisaku kenkyu no genjo

Energy Technology Data Exchange (ETDEWEB)

Shindo, Y [National Institute of Materials and Chemical Research, Tsukuba (Japan)

1993-02-01

This paper summarizes study trends mainly in CO2 fixing processes. Underground CO2 storage is a most promising method because it can fix a huge amount of CO2 and has low effects on ecological systems. Storing CO2 in ocean includes such methods as storing it in deep oceans; storing it in deep ocean beds; dissolving it into sea water; neutralizing it with calcium carbonates; and precipitating it as dry ice. Japan, disposing CO2 in these ways, may create international problems. Separation of CO2 may use a chemical absorption process as a superior method. Other processes discussed include a physical adsorption method and a membrane separation method. A useful method for CO2 fixation using marine organisms is fixation using coral reefs. This process will require an overall study including circulation of phosphorus and nitrogen. Marine organisms may include planktons and algae. CO2 fixation using land plants may be able to fix one trillion and 8 hundred billion tons of CO2 as converted to carbon. This process would require forest protection, prevention of desertification, and tree planting. Discussions are being given also on improving power generation cycles, recovering CO2 from automotive exhausts, and backfilling carbons into ground by means of photosynthesis. 23 refs., 7 figs., 1 tab.

Modulate function and effect of 60Co γ-rays on ConA-induced CD4+ and CD8+ subpopulations of lymphocytes

International Nuclear Information System (INIS)

Xu Yujie; Su Liaoyuan; Liu Keliang

1991-03-01

The monocyte-depleted peripheral blood mononuclear cells were separated into B, CD 4 + and CD 8 + subpopulations by a Panning technique with McAb CD 4 and CD 8 . The purity of the B, CD 4 + and CD 8 + subpopulations was 82.7%, 90.4% and 90.8% respectively, which was estimated by an indirect immunofluorescence technique. More than 92% of the three subpopulations were viable according to the trypan blue exclusion test. The radiosensitivities of ConA-induced CD 4 + and CD 8 + cells were assessed by 3 H-TdR incorporation. Experiment demonstrated that a part of ConA-induced CD 4 + and CD 8 + cells was radiosensitive but the rest of them was radioresistant. There was no significant difference between the sensitive part both in the ConA-induced CD 4 + and CD 8 + cells while there was great significant difference between the resistant one in the both cell lines. The modulate functions of ConA-induced CD 4 + and CD 8 + cells and the effect of 10 Gy 60 Co γ-rays on them were investigated by the technique of 3 H-TdR incorporation. It was demonstrated that the transformation of LPS-induced B lymphocytes was suppressed by the ConA-induced CD 4 + and CD 8 + cells. After irradiation, the suppressor activity of ConA-induced CD 4 + and CD 8 + cells didn't decrease. The suppressor activity of ConA-induced CD 8 + cells were enhanced by the ConA-induced CD 4 + cells significantly, and the suppressor activity of ConA-induced CD 4 + cells was also enhanced by the ConA-induced CD 8 + cells. After irradiation, the enhancement effects of the ConA-induced CD 4 + and CD 8 + cells disappeared

Aclimatación de la fotosíntesis en el dosel vegetal del trigo al aumento del CO2 atmosférico: función del nitrógeno y las citoquininas en cultivos en cámaras de campo con clima mediterráneo

OpenAIRE

Gutiérrez del Pozo, Diego

2011-01-01

[ES]En esta tesis se intenta conocer las respuestas de aclimatación al CO2 elevado del intercambio gaseoso del dosel vegetal - hojas superiores iluminadas o inferiores sombreadas - del trigo en cultivos bajo cámaras de campo con cantidades diferentes de fertilizante nitrogenado. También se trata de averiguar el papel en la aclimatación de la absorción de nitrógeno y su reparto entre compuestos y órganos de la parte aérea de la planta. Y por último valorar si la citoquinina exógena, con su acc...

Optimization of supercritical carbon dioxide (CO2 extraction of sardine (Sardinella lemuru Bleeker oil using response surface methodology (RSM

Directory of Open Access Journals (Sweden)

Gedi, M. A.

2015-06-01

Full Text Available Oil was extracted from freeze-dried sardine (Sardinella lemur fillets using supercritical carbon dioxide (SC-CO2 and a few milliliters of ethanol were optimized with response surface methodology (RSM. The impact of extraction pressure (200–400 bars and temperature (40–70 °C were studied on the total extraction yields, ratios of Eicosapentaenoic acid (EPA and Docosahexaenoic acid (DHA. The results were compared with those of Soxhlet and modified Kinsella methods (MKM. The oils obtained using the SC-CO2 and MKM methods were significantly (P El aceite se extrae de filetes de sardinas (Sardinella lemur liofilizando, mediante dióxido de carbono supercrítico (SC-CO2 y unos mililitros de etanol, optimizándose mediante la metodología de superficie de respuesta (RSM. Se ha estudiado la influencia de la presión de extracción (200–400 bars y la temperatura (40–70 °C sobre los rendimientos de extracción total, y sobre las relaciones de ácido eicosapentaenoico (EPA y ácido docosahexaenoico (DHA. Los resultados se compararon con los obtenidos mediante extracción con Soxhlet y el método de Kinsella modificado (MKM. Los aceites obtenidos mediante SC-CO2 y métodos MKM fueron significativamente (P < 0.05 superiores en rendimientos de aceite (8,04% y 6,83%, EPA (5,43% y 5,45% y DHA (18,76% y 18,54%, respectivamente, en comparación con rendimientos mediante Soxhlet (5,10%, EPA (2,17% y DHA (06,46%. De las dos variables independientes, la presión tuvo un efecto crítico sobre el rendimiento, mientras que los porcentajes de EPA y DHA estuvieron notablemente influenciados por la temperatura. Los valores óptimos fueron para una presión de 328 bar y una temperatura de 40 °C, y sus correspondientes respuestas fueron 7,20%, 5,68% y 20,09% para el rendimiento, EPA y DHA, respectivamente. Los valores experimentales de este estudio fueron los previstos y son comparables razonablemente con sus homólogos.

The Density and Compressibility of BaCO3-SrCO3-CaCO3-K2CO3-Na2CO3-Li2CO3 Liquids: New Measurements and a Systematic Trend with Cation Field Strength

Science.gov (United States)

Hurt, S. M.; Lange, R. A.; Ai, Y.

2015-12-01

The volumetric properties of multi-component carbonate liquids are required to extend thermodynamic models that describe partial melting of the deep mantle (e.g. pMELTS; Ghiorso et al., 2003) to carbonate-bearing lithologies. Carbonate in the mantle is an important reservoir of carbon, which is released to the atmosphere as CO2 through volcanism, and thus contributes to the carbon cycle. Although MgCO3 is the most important carbonate component in the mantle, it is not possible to directly measure the 1-bar density and compressibility of MgCO3 liquid because, like other alkaline-earth carbonates, it decomposes at a temperature lower than its melting temperature. Despite this challenge, Liu and Lange (2003) and O'Leary et al. (2015) showed that the one bar molar volume, thermal expansion and compressibility of the CaCO3 liquid component could be obtained by measuring the density and sound speeds of stable liquids in the CaCO3-Li2CO3-Na2CO3-K2CO3 quaternary system at one bar. In this study, this same strategy is employed on SrCO3- and BaCO3-bearing alkali carbonate liquids. The density and sound speed of seven liquids in the SrCO3-Li2CO3-Na2CO3-K2CO3 quaternary and three liquids in the BaCO3-Li2CO3-Na2CO3-K2CO3 quaternary were measured from 739-1367K, with SrCO3 and BaCO3 concentrations ranging from 10-50 mol%. The density measurements were made using the double-bob Archimedean method and sound speeds were obtained with a frequency-sweep acoustic interferometer. The molar volume and sound speed measurements were used to calculate the isothermal compressibility of each liquid, and the results show the volumetric properties mix ideally with composition. The partial molar volume and compressibility of the SrCO3 and BaCO3 components are compared to those obtained for the CaCO3 component as a function of cation field strength. The results reveal a systematic trend that allows the partial molar volume and compressibility of the MgCO3 liquid component to be estimated.

Efecto del CO2 en la atmósfera de almacenamiento sobre la fisiología de la aceituna de molino

Directory of Open Access Journals (Sweden)

García Martos, J. María

1993-04-01

Full Text Available Olive fruits (Olea europaea used for oil production were stored at 5 °C and four different atmospheres (%CO2/%O2/%N2: 0/21/78; 5/20/75; 10/19/71 and 20/17/63. At 5 °C the enrichment of the storage atmosphere with > 5% CO2 concentrations produced a proportional increase of the physiological disorder occurring in stored fruits. This occurrence had a strong relationship with the appearance of fruit decay. Simple refrigeration at 5 °C was sufficient to maintain the same degree of ripening of olive fruits for 60 days. However, a longer period of storage at 5 °C originated a remarkable incidence of chilling injuries in the fruits.Aceitunas (Olea europaea destinadas a la producción de aceite, se han conservado con refrigeración a 5 °C y en cuatro diferentes atmósferas (%CO2/%O2/%N2: 0/21/78; 5/20/75; 10/19/71 y 20/17/63. A 5 °C el enriquecimiento de la atmósfera de conservación con una concentración igual o superior al 5% de CO2 provocó un aumento proporcional de la incidencia de desórdenes fisiológicos. Esta incidencia tuvo una relación estrecha con la presencia de podredumbre en el fruto. La simple refrigeración a 5 °C permitió retener durante 60 días el grado de maduración de las aceitunas. Sin embargo, un periodo de almacenamiento más prolongado a 5 °C provocó en los frutos una notable incidencia de lesiones por frío.

Inexpensive CO2 Thickening Agents for Improved Mobility Control of CO2 Floods

Energy Technology Data Exchange (ETDEWEB)

Robert Enick; Eric Beckman; Andrew Hamilton

2005-08-31

The objective of this research was the design, synthesis and evaluation of inexpensive, non-fluorous carbon dioxide thickening agents. We followed the same strategy employed in the design of fluorinated CO{sub 2} polymeric thickeners. First, a highly CO{sub 2}-philic, hydrocarbon-based monomer was to be identified. Polymers or oligomers of this monomer were then synthesized. The second step was to design a CO{sub 2}-thickener based on these CO{sub 2}-philic polymers. Two types of thickeners were considered. The first was a copolymer in which the CO{sub 2}-philic monomer was combined with a small proportion of CO{sub 2}-phobic associating groups that could cause viscosity-enhancing intermolecular interactions to occur. The second was a small hydrogen-bonding compound with urea groups in the core to promote intermolecular interactions that would cause the molecules to 'stack' in solution while the arms were composed of the CO{sub 2}-philic oligomers. Although we were not able to develop a viable thickener that exhibited high enough CO{sub 2} solubility at EOR MMP conditions to induce a viscosity increase, we made significant progress in our understanding of CO{sub 2}-soluble compounds that can be used in subsequent studies to design CO{sub 2}-soluble thickeners or CO{sub 2}-soluble surfactant-based foaming agents. These findings are detailed in this final report. In summary, we assessed many polymers and verified that the most CO{sub 2}-soluble oxygenated hydrocarbon polymer is poly(vinyl acetate), PVAc. This is primarily due to the presence of both ether and carbonyl oxygens associated with acetate-rich compounds. In addition to polymers, we also made small acetate-rich molecules that were also capable of associating in solution via the inclusion of hydrogen-bonding groups in hopes of forming viscosity-enhancing macromolecules. Despite the presence of multiple acetate groups in these compounds, which can impart incredible CO{sub 2}-solubility to many

A study of CO2 precipitation method considering an ionic CO2 and Ca(OH)2 slurry

International Nuclear Information System (INIS)

Park, Sangwon; Jo, Hoyong; Kang, Dongwoo; Park, Jinwon

2014-01-01

CCS (carbon capture and storage) is the most popular technology used for the reduction of CO 2 in the post-combustion stage. However, the CCS process has some disadvantages including uncertainty about the stability of the land that is used to store the separated CO 2 . Consequently, CCU (carbon capture and utilization) technologies have recently received increased attention as a possible replacement for CCS. In this study, we utilized CO 2 fixation methods by using the metal carbonate mechanism. We selected 5 and 30 wt% MEA (mono-ethanolamine) solutions to rapidly make a carbonate and Ca(OH) 2 slurry. In all of the experiments, normal temperature and pressure conditions were maintained (except during desorption to check for residual CO 2 in the MEA solution). Consequently, most of the CO 2 was converted to carbonate. The MEA converted CO 2 to ionic CO 2 and rapidly created calcium carbonate. Also the formed solids that were observed were determined to be CaCO 3 and Ca(OH) 2 by X-ray diffractometry. Also, the MEA solution could be reused to absorb CO 2 . Therefore, we have confirmed the development of our suggested CCS process. This process has the ability not only to reuse emitted CO 2 , but it can also be employed to reuse construction wastes that include heavy metals. - Highlights: • We propose novel CO 2 conversion technology by utilizing an amine solution. • In this study, alkaline solutions were used to produce CO 2 precipitate. • The MEA (mono-ethanolamine) solution has a sufficient potential to fix CO 2 with metal sources under moderate condition. • Also, the Ca(OH) 2 slurry yielded enough Ca 2+ ions to make carbonate

CO2NNIE

DEFF Research Database (Denmark)

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

2015-01-01

We propose a system for calculating the personalized annual fuel consumption and CO2 emissions from transportation. The system, named CO2NNIE, estimates the fuel consumption on the fastest route between the frequent destinations of the user. The travel time and fuel consumption estimated are based......% of the actual fuel consumption (4.6% deviation on average). We conclude, that the system provides new detailed information on CO2 emissions and fuel consumption for any make and model....

Outsourcing CO2 Emissions

Science.gov (United States)

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

2009-12-01

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

Overview of the IEA GHG Weyburn-Midale CO{sub 2} monitoring and storage project

Energy Technology Data Exchange (ETDEWEB)

Mourits, Frank [Natural Resources Canada (Canada)

2008-07-15

In this presentation it is explained what the Weyburn-Midale project consists of; it is also spoken on the operation for the enhanced oil recovery of Encana Weyburn and Apache Midale Commercial; an overview and results are given of phase I (2000-2004) of the Weyburn project of monitoring and CO{sub 2} storage of greenhouse effect gases of the International Energy Agency; Characteristics and statistics of operation of the oil fields Weyburn and Midale, and how is it that with CO{sub 2} and recycled water the oil is recovered?. [Spanish] En esta presentacion se explica en que consiste el proyecto Weyburn-Midale; se habla tambien sobre la operacion para la recuperacion mejorada de petroleo de Encana Weyburn y Apache Midale Commercial; se da una vision general y resultados de la fase I (2000-2004) del proyecto Weyburn de monitoreo y almacenamiento de CO{sub 2} gases de efecto invernadero de la Agencia Internacional de Energia; Caracteristicas y estadisticas de operacion de los yacimientos petroliferos Weyburn y Midale, y como es que con el CO{sub 2} y agua reciclada se recupera el petroleo?.

CO2-Water-Rock Wettability: Variability, Influencing Factors, and Implications for CO2 Geostorage.

Science.gov (United States)

Iglauer, Stefan

2017-05-16

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

Enhancing Catalyzed Decomposition of Na2CO3 with Co2MnO x Nanowire-Decorated Carbon Fibers for Advanced Na-CO2 Batteries.

Science.gov (United States)

Fang, Cong; Luo, Jianmin; Jin, Chengbin; Yuan, Huadong; Sheng, Ouwei; Huang, Hui; Gan, Yongping; Xia, Yang; Liang, Chu; Zhang, Jun; Zhang, Wenkui; Tao, Xinyong

2018-05-23

The metal-CO 2 batteries, especially Na-CO 2 , batteries come into sight owing to their high energy density, ability for CO 2 capture, and the abundance of sodium resource. Besides the sluggish electrochemical reactions at the gas cathodes and the instability of the electrolyte at a high voltage, the final discharge product Na 2 CO 3 is a solid and poor conductor of electricity, which may cause the high overpotential and poor cycle performance for the Na-CO 2 batteries. The promotion of decomposition of Na 2 CO 3 should be an efficient strategy to enhance the electrochemical performance. Here, we design a facile Na 2 CO 3 activation experiment to screen the efficient cathode catalyst for the Na-CO 2 batteries. It is found that the Co 2 MnO x nanowire-decorated carbon fibers (CMO@CF) can promote the Na 2 CO 3 decomposition at the lowest voltage among all these metal oxide-decorated carbon fiber structures. After assembling the Na-CO 2 batteries, the electrodes based on CMO@CF show lower overpotential and better cycling performance compared with the electrodes based on pristine carbon fibers and other metal oxide-modified carbon fibers. We believe this catalyst screening method and the freestanding structure of the CMO@CF electrode may provide an important reference for the development of advanced Na-CO 2 batteries.

Forecasting global atmospheric CO2

International Nuclear Information System (INIS)

Agusti-Panareda, A.; Massart, S.; Boussetta, S.; Balsamo, G.; Beljaars, A.; Engelen, R.; Jones, L.; Peuch, V.H.; Chevallier, F.; Ciais, P.; Paris, J.D.; Sherlock, V.

2014-01-01

A new global atmospheric carbon dioxide (CO 2 ) real-time forecast is now available as part of the preoperational Monitoring of Atmospheric Composition and Climate - Interim Implementation (MACC-II) service using the infrastructure of the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecasting System (IFS). One of the strengths of the CO 2 forecasting system is that the land surface, including vegetation CO 2 fluxes, is modelled online within the IFS. Other CO 2 fluxes are prescribed from inventories and from off-line statistical and physical models. The CO 2 forecast also benefits from the transport modelling from a state-of-the-art numerical weather prediction (NWP) system initialized daily with a wealth of meteorological observations. This paper describes the capability of the forecast in modelling the variability of CO 2 on different temporal and spatial scales compared to observations. The modulation of the amplitude of the CO 2 diurnal cycle by near-surface winds and boundary layer height is generally well represented in the forecast. The CO 2 forecast also has high skill in simulating day-to-day synoptic variability. In the atmospheric boundary layer, this skill is significantly enhanced by modelling the day-to-day variability of the CO 2 fluxes from vegetation compared to using equivalent monthly mean fluxes with a diurnal cycle. However, biases in the modelled CO 2 fluxes also lead to accumulating errors in the CO 2 forecast. These biases vary with season with an underestimation of the amplitude of the seasonal cycle both for the CO 2 fluxes compared to total optimized fluxes and the atmospheric CO 2 compared to observations. The largest biases in the atmospheric CO 2 forecast are found in spring, corresponding to the onset of the growing season in the Northern Hemisphere. In the future, the forecast will be re-initialized regularly with atmospheric CO 2 analyses based on the assimilation of CO 2 products retrieved from satellite

CO{sub 2} sequestration technologies

Energy Technology Data Exchange (ETDEWEB)

Ketzer, Marcelo [Brazilian Carbon Storage Research Center (Brazil)

2008-07-15

In this presentation the importance of the capture and sequestration of CO{sub 2} is outlined for the reduction of gas discharges of greenhouse effect; then the principles of CO{sub 2} storage in geologic formations are reviewed; afterwards, the analogs for the CO{sub 2} storage are commented, such as the storage of the acid gas, the natural gas storage and the natural CO{sub 2} deposits. Also it is spoken on the CO{sub 2} storage in coal, in water-bearing saline deposits and in oil fields, and finally the subject of the safety and monitoring of the CO{sub 2} storage is reviewed. [Spanish] En esta presentacion se expone la importancia de la captura y secuestro de CO{sub 2} para la reduccion de emisiones de gases de efecto invernadero; luego se tratan los principios de almacenamiento de CO{sub 2} en formaciones geologicas; despues se comentan los analogos para el almacenamiento de CO{sub 2} como el almacenamiento del gas acido, el almacenamiento de gas natural y los yacimientos naturales de CO{sub 2}. Tambien se habla sobre el almacenamiento de CO{sub 2} en carbon, acuiferos salinos y yacimientos petroliferos y por ultimo se toca el tema de la seguridad y monitoreo del almacenamiento de CO{sub 2}.

Solid state synthesis of stoichiometric LiCoO2 from mechanically activated Co-Li2CO3 mixtures

International Nuclear Information System (INIS)

Berbenni, Vittorio; Milanese, Chiara; Bruni, Giovanna; Marini, Amedeo

2006-01-01

Stoichiometric lithium cobalt oxide (LiCoO 2 ) has been synthesized by solid state reaction of mixtures of the system Co-0.5Li 2 CO 3 after mechanical activation by high energy milling. The differences in the reaction mechanism and in product stoichiometry with respect to what happens when starting from the non activated (physical) system have been brought into evidence by TG analysis. Furthermore it has been shown that stoichiometric LiCoO 2 is obtained by a 200 h annealing of the activated mixture at temperatures as low as 400 deg. C. Finally, it has been revealed that longer activation times (150 h) result in Co oxidation to Co 3 O 4 that, in turn, hampers the formation of stoichiometric LiCoO 2

Development of Novel CO2 Adsorbents for Capture of CO2 from Flue Gas

Energy Technology Data Exchange (ETDEWEB)

Fauth, D.J.; Filburn, T.P. (University of Hartford, West Hartford, CT); Gray, M.L.; Hedges, S.W.; Hoffman, J.; Pennline, H.W.; Filburn, T.

2007-06-01

Capturing CO2 emissions generated from fossil fuel-based power plants has received widespread attention and is considered a vital course of action for CO2 emission abatement. Efforts are underway at the Department of Energy’s National Energy Technology Laboratory to develop viable energy technologies enabling the CO2 capture from large stationary point sources. Solid, immobilized amine sorbents (IAS) formulated by impregnation of liquid amines within porous substrates are reactive towards CO2 and offer an alternative means for cyclic capture of CO2 eliminating, to some degree, inadequacies related to chemical absorption by aqueous alkanolamine solutions. This paper describes synthesis, characterization, and CO2 adsorption properties for IAS materials previously tested to bind and release CO2 and water vapor in a closed loop life support system. Tetraethylenepentamine (TEPA), acrylonitrile-modified tetraethylenepentamine (TEPAN), and a single formulation consisting of TEPAN and N, N’-bis(2-hydroxyethyl)ethylenediamine (BED) were individually supported on a poly (methyl methacrylate) (PMMA) substrate and examined. CO2 adsorption profiles leading to reversible CO2 adsorption capacities were obtained using thermogravimetry. Under 10% CO2 in nitrogen at 25°C and 1 atm, TEPA supported on PMMA over 60 minutes adsorbed ~3.2 mmol/g{sorbent} whereas, TEPAN supported on PMMA along with TEPAN and BED supported on PMMA adsorbed ~1.7 mmol/g{sorbent} and ~2.3 mmol/g{sorbent} respectively. Cyclic experiments with a 1:1 weight ratio of TEPAN and BED supported on poly (methyl methacrylate) beads utilizing a fixed-bed flow system with 9% CO2, 3.5% O2, nitrogen balance with trace gas constituents were studied. CO2 adsorption capacity was ~ 3 mmols CO2/g{sorbent} at 40°C and 1.4 atm. No beneficial effect on IAS performance was found using a moisture-laden flue gas mixture. Tests with 750 ppmv NO in a humidified gas stream revealed negligible NO sorption onto the IAS. A high SO2

Metal-Organic Framework-Stabilized CO2/Water Interfacial Route for Photocatalytic CO2 Conversion.

Science.gov (United States)

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

2017-11-29

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

Propiedades estructurales y magnéticas de nanopartículas de Co2Au10

OpenAIRE

García Mayo, Sara

2017-01-01

Hemos llevado a cabo una búsqueda del estado fundamental de la nanoaleación Co2Au10, que hemos comprobado que puede ser vista como un dímero de Co recubierto por diez átomos de Au, con vistas a encontrar un bit magnético estable en el límite de la miniaturización, y hemos estudiado sus propiedades estructurales y magnéticas desde una aproximación relativista escalar. Los cálculos se han realizado empleando el código VASP (Vienna Ab initio Simulation Package), que es una impleme...

CO{sub 2} separation from exhaust gas; CO{sub 2} separasjon fra eksosgass

Energy Technology Data Exchange (ETDEWEB)

Magelssen, Paul Fr. [Saga Petroleum A/S, Forus (Norway)

1998-07-01

When Saga wanted to reduce the CO{sub 2} emissions from Snorre B, cleaning of CO{sub 2} from exhaust gas was one of several options considered. CO{sub 2} cleaning using membrane/amine technology is under development. Saga required that the technology should be qualified and that the yield of the Snorre B project should not be reduced. This presentation discusses qualification of combined membrane/amine technology, environmental issues, economic issues and implementation on the Snorre B platform. Flue gas from the gas turbine is passed to a CO{sub 2} absorption and desorption stage from which the CO{sub 2} is passed on for compression and disposal while the cleaned flue is let out. The membrane is situated between the flue gas and the absorbent liquid. The pores are large enough for the CO{sub 2} to pass through quickly and small enough to prevent the liquid from penetrating into the pores. The packing factor is high, 500 - 1000 m2/m3, there is no formation of froth, ducts or entrainment of the liquid. New technology implies 65 - 70% size reduction of the main equipment and 39 - 40% reduction of the energy consumption. Research on amines brings out new chemicals which imply 80% reduction in the consumption of chemicals and the quantity of special waste produced. If a CO{sub 2} cleaning plant is installed on a LM 2500, the CO{sub 2} emissions can be reduced by 97,200 ton/year given the right operational conditions. Although it was decided in 1998 not to install the module with the CO{sub 2} pilot cleaning plant, Snorre B is still a good environmental project having CO{sub 2} emission within the values set by Miljoesok.

Surface CO2 leakage during the first shallow subsurface CO2 release experiment

OpenAIRE

Lewicki, J.L.; Oldenburg, C.; Dobeck, L.; Spangler, L.

2008-01-01

A new field facility was used to study CO2 migration processes and test techniques to detect and quantify potential CO2 leakage from geologic storage sites. For 10 days starting 9 July 2007, and for seven days starting 5 August 2007, 0.1 and 0.3 t CO2 d-1, respectively, were released from a ~;100-m long, sub-water table (~;2.5-m depth) horizontal well. The spatio-temporal evolution of leakage was mapped through repeated grid measurements of soil CO2 flux (FCO2). The surface leakage onset...

The physical chemistry of coordinated aqua-, ammine-, and mixed-ligand Co2+ complexes: DFT studies on the structure, energetics, and topological properties of the electron density.

Science.gov (United States)

Varadwaj, Pradeep R; Marques, Helder M

2010-03-07

Spin-unrestricted DFT-X3LYP/6-311++G(d,p) calculations have been performed on a series of complexes of the form [Co(H(2)O)(6-n)(NH(3))(n)](2+) (n = 0-6) to examine their equilibrium gas-phase structures, energetics, and electronic properties in their quartet electronic ground states. In all cases Co(2+) in the energy-minimised structures is in a pseudo-octahedral environment. The calculations overestimate the Co-O and Co-N bond lengths by 0.04 and 0.08 A, respectively, compared to the crystallographically observed mean values. There is a very small Jahn-Teller distortion in the structure of [Co(H(2)O)(6)](2+) which is in contrast to the very marked distortions observed in most (but not all) structures of this cation that have been observed experimentally. The successive replacement of ligated H(2)O by NH(3) leads to an increase in complex stability by 6 +/- 1 kcal mol(-1) per additional NH(3) ligand. Calculations using UB3LYP give stabilisation energies of the complexes about 5 kcal mol(-1) smaller and metal-ligand bond lengths about 0.005 A longer than the X3LYP values since the X3LYP level accounts for the London dispersion energy contribution to the overall stabilisation energy whilst it is largely missing at the B3LYP level. From a natural population analysis (NPA) it is shown that the formation of these complexes is accompanied by ligand-to-metal charge transfer the extent of which increases with the number of NH(3) ligands in the coordination sphere of Co(2+). From an examination of the topological properties of the electron charge density using Bader's quantum theory of atoms in molecules it is shown that the electron density rho(c) at the Co-O bond critical points is generally smaller than that at the Co-N bond critical points. Hence Co-O bonds are weaker than Co-N bonds in these complexes and the stability increases as NH(3) replaces H(2)O in the metal's coordination sphere. Several indicators, including the sign and magnitude of the Laplacian of the

Wheat germ oil extracted by supercritical carbon dioxide with ethanol: Fatty acid composition; Aceite de germen de trigo obtenido mediante extracción con dióxido de carbono supercrítico con etanol: Composición en ácidos grasos

Energy Technology Data Exchange (ETDEWEB)

Parczewska-Plesnar, B.; Brzozowski, R.; Gwardiak, H.; Białecka-Florjańczyk, E.; Bujnowski, Z.

2016-07-01

In this work, supercritical fluid extraction (SFE) using CO2 with ethanol as entrainer was performed at a temperature of 40 o C under a pressure of 21 MPa. For comparison, a similar extraction without the entrainer was carried out. The extraction yield of wheat germ using supercritical CO2 with ethanol was slightly higher (10.7 wt%) than that of extraction without the entrainer (9.9 wt%). Fractions of SFE extracts were collected separately during the experiments and the composition of fatty acids in each fraction was analyzed. The SFE extracted oils were rich (63.4-71.3%) in the most valuable polyunsaturated fatty acids (PUFA) and their content in all collected fractions was approximately constant. Similar PUFA contents were found in the reference samples of oils extracted by n-hexane (66.2-67.0%), while the commercial cold-pressed oil contained significantly less PUFA (60.2%). These results show a higher nutritional value of the oil obtained by extraction with supercritical CO2 than cold pressed oil which is generally considered to be very valuable. [Spanish] En este trabajo, la extracción con fluidos supercríticos (SFE) usando CO2 con etanol como agente de arrastre se realizó a 40 °C bajo una presión de 21 MPa. Se ha llevado a cabo la comparación con una extracción similar sin agente de arrastre. El rendimiento de la extracción de germen de trigo usando CO2 supercrítico con etanol fue ligeramente mayor (10,7% en peso) que la de extracción sin agente de arrastre (9,9% en peso). Se recogieron por separado fracciones de extractos SFE durante los experimentos y se analizó la composición de ácidos grasos en cada fracció . Los aceites extraídos mediante SFE eran ricos en los ácidos grasos poliinsaturados más valiosos (63,4-71,3%), (PUFA) y su contenido en todas las fracciones recogidas fue aproximadamente constante. Un contenido similar de PUFA fueron encontrados en muestras de referencia de los aceites extraídos con n-hexano (66,2-67,0%), mientras

Global CO2 fluxes estimated from GOSAT retrievals of total column CO2

Directory of Open Access Journals (Sweden)

S. Basu

2013-09-01

Full Text Available We present one of the first estimates of the global distribution of CO2 surface fluxes using total column CO2 measurements retrieved by the SRON-KIT RemoTeC algorithm from the Greenhouse gases Observing SATellite (GOSAT. We derive optimized fluxes from June 2009 to December 2010. We estimate fluxes from surface CO2 measurements to use as baselines for comparing GOSAT data-derived fluxes. Assimilating only GOSAT data, we can reproduce the observed CO2 time series at surface and TCCON sites in the tropics and the northern extra-tropics. In contrast, in the southern extra-tropics GOSAT XCO2 leads to enhanced seasonal cycle amplitudes compared to independent measurements, and we identify it as the result of a land–sea bias in our GOSAT XCO2 retrievals. A bias correction in the form of a global offset between GOSAT land and sea pixels in a joint inversion of satellite and surface measurements of CO2 yields plausible global flux estimates which are more tightly constrained than in an inversion using surface CO2 data alone. We show that assimilating the bias-corrected GOSAT data on top of surface CO2 data (a reduces the estimated global land sink of CO2, and (b shifts the terrestrial net uptake of carbon from the tropics to the extra-tropics. It is concluded that while GOSAT total column CO2 provide useful constraints for source–sink inversions, small spatiotemporal biases – beyond what can be detected using current validation techniques – have serious consequences for optimized fluxes, even aggregated over continental scales.

CO{sub 2} geothermal heat probe - Phase 2; CO{sub 2}-Erdwaermesonde - Phase 2

Energy Technology Data Exchange (ETDEWEB)

Grueniger, A.; Wellig, B.

2009-12-15

In this project the fluid dynamics and thermodynamics inside a CO{sub 2} geothermal heat probe have been investigated. The functionality of such a probe, which works like a thermosyphon, was analyzed by means of a simulation model in MATLAB. The model couples the behaviour inside the heat probe with the heat conduction in the earth. A parameter study revealed that the self-circulation character of such a probe leads to flattening of the vertical earth temperature profile near the probe and, hence, leads to more uniform heat removal along the probe. The circulation of CO{sub 2} even goes on when the heat pump is off. This might be advantageous for the regeneration phase. The heat transfer resistance of the evaporating CO{sub 2} film flowing down the probe wall is very small compared to the conduction resistance of the earth. Therefore, no difference has been found between the performances of a conventional heat pipe and a configuration where the liquid phase injection is distributed on different height stages along the probe. It is estimated that the seasonal performance factor of heat pumps can be improved by 15-25% with a CO{sub 2} geothermal heat probe. The main advantage is that the heat transfer to the evaporator of the heat pump (condensation of CO{sub 2} / evaporation of refrigerant) is much more efficient than in a conventional brine probe without phase change. Furthermore, no circulation pump is needed. (authors)

Reactor de película líquida descendente para la sulfonación de ésteres metílicos con trióxido de azufre

Directory of Open Access Journals (Sweden)

Jesús Alfonso Torres Ortega

2009-09-01

Full Text Available Se realizó un conjunto de experimentos de sulfonación de dodecilbenceno (DDB y ésteres metílicos (ME derivados de la esteari- na hidrogenada de palma, con SO3 gaseoso desorbido del óleum, en un reactor de sulfonación en película líquida descendente a escala banco de 40 cm de longitud y ½ pulgada de diámetro interno. Mediante titulaciones volumétricas se determinaron los porcentajes de materia sulfonada y contenido de ácido sulfúrico, así como el porcentaje de aceite libre mediante extracciones con éter de petróleo. La funcionalidad del reactor se verificó efectuando ensayos a condiciones reportadas por Gutiérrez y cola- boradores para dodecilbenceno sulfonado (DDBS, para lo cual fueron determinadas las técnicas de análisis en el Laboratorio de Ingeniería Química (LIQ de la Universidad Nacional de Colombia, sede Bogotá, con el acompañamiento de la empresa Química Básica Colombiana (Caloto, Cauca. Finalmente, se procedió a evaluar la influencia de diferentes variables de proce- so sobre la sulfonación de la mezcla de ésteres metílicos. Los resultados obtenidos en el sulfonador se ajustaron por regresión li- neal múltiple a ecuaciones empíricas, obteniendo expresiones que muestran de forma directa el efecto de variables como la re- lación molar SO3/ME, concentración de SO3 en la corriente gaseosa y flujo másico de ME.

How secure is subsurface CO2 storage? Controls on leakage in natural CO2 reservoirs

Science.gov (United States)

Miocic, Johannes; Gilfillan, Stuart; McDermott, Christopher; Haszeldine, Stuart

2014-05-01

Carbon Capture and Storage (CCS) is the only industrial scale technology available to directly reduce carbon dioxide (CO2) emissions from fossil fuelled power plants and large industrial point sources to the atmosphere. The technology includes the capture of CO2 at the source and transport to subsurface storage sites, such as depleted hydrocarbon reservoirs or saline aquifers, where it is injected and stored for long periods of time. To have an impact on the greenhouse gas emissions it is crucial that there is no or only a very low amount of leakage of CO2 from the storage sites to shallow aquifers or the surface. CO2 occurs naturally in reservoirs in the subsurface and has often been stored for millions of years without any leakage incidents. However, in some cases CO2 migrates from the reservoir to the surface. Both leaking and non-leaking natural CO2 reservoirs offer insights into the long-term behaviour of CO2 in the subsurface and on the mechanisms that lead to either leakage or retention of CO2. Here we present the results of a study on leakage mechanisms of natural CO2 reservoirs worldwide. We compiled a global dataset of 49 well described natural CO2 reservoirs of which six are leaking CO2 to the surface, 40 retain CO2 in the subsurface and for three reservoirs the evidence is inconclusive. Likelihood of leakage of CO2 from a reservoir to the surface is governed by the state of CO2 (supercritical vs. gaseous) and the pressure in the reservoir and the direct overburden. Reservoirs with gaseous CO2 is more prone to leak CO2 than reservoirs with dense supercritical CO2. If the reservoir pressure is close to or higher than the least principal stress leakage is likely to occur while reservoirs with pressures close to hydrostatic pressure and below 1200 m depth do not leak. Additionally, a positive pressure gradient from the reservoir into the caprock averts leakage of CO2 into the caprock. Leakage of CO2 occurs in all cases along a fault zone, indicating that

CO2 Accounting and Risk Analysis for CO2 Sequestration at Enhanced Oil Recovery Sites.

Science.gov (United States)

Dai, Zhenxue; Viswanathan, Hari; Middleton, Richard; Pan, Feng; Ampomah, William; Yang, Changbing; Jia, Wei; Xiao, Ting; Lee, Si-Yong; McPherson, Brian; Balch, Robert; Grigg, Reid; White, Mark

2016-07-19

Using CO2 in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce sequestration costs in the absence of emissions policies that include incentives for carbon capture and storage. This study develops a multiscale statistical framework to perform CO2 accounting and risk analysis in an EOR environment at the Farnsworth Unit (FWU), Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil/gas-water flow and transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2/water injection/production rates, cumulative net CO2 storage, cumulative oil/gas productions, and CO2 breakthrough time. The median and confidence intervals are estimated for quantifying uncertainty ranges of the risk metrics. A response-surface-based economic model has been derived to calculate the CO2-EOR profitability for the FWU site with a current oil price, which suggests that approximately 31% of the 1000 realizations can be profitable. If government carbon-tax credits are available, or the oil price goes up or CO2 capture and operating expenses reduce, more realizations would be profitable. The results from this study provide valuable insights for understanding CO2 storage potential and the corresponding environmental and economic risks of commercial-scale CO2-sequestration in depleted reservoirs.

Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

Science.gov (United States)

Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

2016-04-01

In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

How much CO2 is trapped in carbonate minerals of a natural CO2 occurrence?

Science.gov (United States)

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

2017-04-01

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

CO2 dispersion modelling over Paris region within the CO2-MEGAPARIS project

Directory of Open Access Journals (Sweden)

C. Lac

2013-05-01

Full Text Available Accurate simulation of the spatial and temporal variability of tracer mixing ratios over urban areas is a challenging and interesting task needed to be performed in order to utilise CO2 measurements in an atmospheric inverse framework and to better estimate regional CO2 fluxes. This study investigates the ability of a high-resolution model to simulate meteorological and CO2 fields around Paris agglomeration during the March field campaign of the CO2-MEGAPARIS project. The mesoscale atmospheric model Meso-NH, running at 2 km horizontal resolution, is coupled with the Town Energy Balance (TEB urban canopy scheme and with the Interactions between Soil, Biosphere and Atmosphere CO2-reactive (ISBA-A-gs surface scheme, allowing a full interaction of CO2 modelling between the surface and the atmosphere. Statistical scores show a good representation of the urban heat island (UHI with stronger urban–rural contrasts on temperature at night than during the day by up to 7 °C. Boundary layer heights (BLH have been evaluated on urban, suburban and rural sites during the campaign, and also on a suburban site over 1 yr. The diurnal cycles of the BLH are well captured, especially the onset time of the BLH increase and its growth rate in the morning, which are essential for tall tower CO2 observatories. The main discrepancy is a small negative bias over urban and suburban sites during nighttime (respectively 45 m and 5 m, leading to a few overestimations of nocturnal CO2 mixing ratios at suburban sites and a bias of +5 ppm. The diurnal CO2 cycle is generally well captured for all the sites. At the Eiffel tower, the observed spikes of CO2 maxima occur every morning exactly at the time at which the atmospheric boundary layer (ABL growth reaches the measurement height. At suburban ground stations, CO2 measurements exhibit maxima at the beginning and at the end of each night, when the ABL is fully contracted, with a strong spatio-temporal variability. A

Synthesis, Structure, Bonding, and Reactivity of Metal Complexes Comprising Diborane(4) and Diborene(2): [{Cp*Mo(CO)2 }2 {μ-η2 :η2 -B2 H4 }] and [{Cp*M(CO)2 }2 B2 H2 M(CO)4 ], M=Mo,W.

Science.gov (United States)

Mondal, Bijan; Bag, Ranjit; Ghorai, Sagar; Bakthavachalam, K; Jemmis, Eluvathingal D; Ghosh, Sundargopal

2018-04-26

The reaction of [(Cp*Mo) 2 (μ-Cl) 2 B 2 H 6 ] (1) with CO at room temperature led to the formation of the highly fluxional species [{Cp*Mo(CO) 2 } 2 {μ-η 2 :η 2 -B 2 H 4 }] (2). Compound 2, to the best of our knowledge, is the first example of a bimetallic diborane(4) conforming to a singly bridged C s structure. Theoretical studies show that 2 mimics the Cotton dimolybdenum-alkyne complex [{CpMo(CO) 2 } 2 C 2 H 2 ]. In an attempt to replace two hydrogen atoms of diborane(4) in 2 with a 2e [W(CO) 4 ] fragment, [{Cp*Mo(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (3) was isolated upon treatment with [W(CO) 5 ⋅thf]. Compound 3 shows the intriguing presence of [B 2 H 2 ] with a short B-B length of 1.624(4) Å. We isolated the tungsten analogues of 3, [{Cp*W(CO) 2 } 2 B 2 H 2 W(CO) 4 ] (4) and [{Cp*W(CO) 2 } 2 B 2 H 2 Mo(CO) 4 ] (5), which provided direct proof of the existence of the tungsten analogue of 2. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detecting annual and seasonal variations of CO2, CO and N2O from a multi-year collocated satellite-radiosonde data-set using the new Rapid Radiance Reconstruction (3R-N) model

International Nuclear Information System (INIS)

Chedin, A.; Serrar, S.; Hollingsworth, A.; Armante, R.; Scott, N.A.

2003-01-01

The NOAA polar meteorological satellites have embarked the TIROS-N operational vertical sounder (TOVS) since 1979. Using radiosondes and NOAA-10 TOVS measurements which are collocated within a narrow space and time window, we have studied the differences between the TOVS measurements and simulated measurements from a new fast, Rapid Radiance Reconstruction Network (3R-N), non-linear radiative transfer model with up to date spectroscopy. Simulations use radiosonde temperature and humidity measurements as the prime input. The radiative transfer model also uses fixed greenhouse gas absorber amounts (CO 2 ,CO,N 2 O) and reasonable estimates of O 3 and of surface temperature. The 3R-N model is first presented and validated. Then, a study of the differences between the simulated and measured radiances shows annual trends and seasonal variations consistent with independent measurements of variations in CO 2 and other greenhouse gases atmospheric concentrations. The improved accuracy of 3R-N and a better handling of its deviations with respect to observations allow most of difficulties met in a previous study (J. Climate 15 (2002) 95) to be resolved

Enclathration of CO2 as a co-guest of structure H hydrates and its implications for CO2 capture and sequestration

International Nuclear Information System (INIS)

Lee, Yohan; Lee, Dongyoung; Lee, Jong-Won; Seo, Yongwon

2016-01-01

Highlights: • We examine sH hydrates with CO 2 + N 2 + neohexane for CO 2 capture and sequestration. • The structural transition occurs in the CO 2 (40%) + N 2 (60%) + neohexane system. • CO 2 molecules are enclathrated into sH hydrates in the N 2 -rich systems. • CO 2 selectivity in sH hydrates is slightly lower than that in sI hydrates. • ΔH d values provide information on the structural transition of sH to sI hydrates. - Abstract: In this study, the thermodynamic behaviors, cage-specific guest distributions, structural transition, and dissociation enthalpies of sH hydrates with CO 2 + N 2 gas mixtures were investigated for their potential applications to hydrate-based CO 2 capture and sequestration. The stability conditions of the CO 2 + N 2 + water systems and the CO 2 + N 2 + neohexane (2,2-dimethylbutane, NH) + water systems indicated that the gas mixtures in the range of flue gas compositions could form sH hydrates, thereby mitigating the pressure and temperature required for gas hydrate formation. Structure identification using powder X-ray diffraction (PXRD) revealed the coexistence of sI and sH hydrates in the CO 2 (40%) + N 2 (60%) + NH system and the hydrate structure transformed from sH into sI as the CO 2 concentration increased. In addition, the Raman analysis clearly demonstrated that CO 2 molecules were enclathrated into the cages of sH hydrates in the N 2 -rich systems. It was found from direct CO 2 composition measurements that CO 2 selectivity in the sH hydrate phase was slightly lower than that in the corresponding sI hydrate phase. Dissociation enthalpy (ΔH d ) measurements using a high-pressure micro-differential scanning calorimeter (HP μ-DSC) indicated that the ΔH d values could also provide valuable information on the structural transition of sH to sI hydrates with respect to the CO 2 concentration in the feed gas. This study provides a better understanding of the thermodynamic and physicochemical background for CO 2

Influencia de la cantidad de O2 adicionado al CO2 en el gas de protección sobre la microestructura del metal depositado en uniones soldadas de bordes rectos en aceros de bajo contenido de carbono con el proceso GMAW Influence of O2 content, added to CO2 in the shielding gas, on the microstructure of deposited metal in butt welded joint with straight edges, in low carbon steels using GMAW process

Directory of Open Access Journals (Sweden)

Eduardo Díaz-Cedré

2010-12-01

Full Text Available La presencia de ferrita acicular (FA en la microestructura del cordón de soldadura, dentro de determinado rango de valores, eleva considerablemente la tenacidad de las uniones soldadas. Es por ello, que el presente trabajo trata sobre un estudio que relaciona la cantidad de ferrita acicular en el cordón en función del contenido de oxígeno presente en la mezcla activa CO2+O2, durante la realización de uniones soldadas de bordes rectos en aceros de bajo carbono con el proceso con electrodo fusible y protección gaseosa (GMAW en condiciones invariables de parámetros de proceso (corriente de soldadura, voltaje de arco, velocidad de soldadura, longitud libre y flujo de gas protector. Como resultado del trabajo se estableció la relación gráfica existente entre la ferrita acicular y el contenido de oxígeno en la mezcla.The presence of acicular ferrite (AF in the microstructure of weld bead, in a specified range of values, increase considerably the toughness of welded joints. The present paper, for that reason, study the relationship between the acicular ferrite quantity in the deposited metal and the oxygen present in the active gas mixture of CO2+O2, during the execution of butt welded joints with straight edges, in low carbon steels with consumable electrode and gas protection (GMAW in invariable conditions of process parameters (welding current, arc voltage, welding speed, electrode extension, and gas flow. The graphic relation between the acicular ferrite and the oxygen content was established, as result of the research work.

Effect of Co crystallinity on Co/CNT catalytic activity in CO/CO{sub 2} hydrogenation and CO disproportionation

Energy Technology Data Exchange (ETDEWEB)

Chernyak, Sergei A., E-mail: chernyak.msu@gmail.com [Lomonosov Moscow State University, Department of Chemistry, Leninskiye Gory 1-3, Moscow 119991 (Russian Federation); Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Department of Physical Chemistry, Leninsky Avenue 31, Moscow 119991 (Russian Federation); Suslova, Evgeniya V.; Egorov, Alexander V.; Maslakov, Konstantin I. [Lomonosov Moscow State University, Department of Chemistry, Leninskiye Gory 1-3, Moscow 119991 (Russian Federation); Savilov, Serguei V.; Lunin, Valery V. [Lomonosov Moscow State University, Department of Chemistry, Leninskiye Gory 1-3, Moscow 119991 (Russian Federation); Kurnakov Institute of General and Inorganic Chemistry of the Russian Academy of Sciences, Department of Physical Chemistry, Leninsky Avenue 31, Moscow 119991 (Russian Federation)

2016-05-30

Highlights: • Amorphous and crystalline Co supported on CNTs were obtained by tuning of CNT surface. • CO and CO{sub 2} hydrogenation does not occur on amorphous Co particles. • Thermal activation of amorphous Co led to crystallization of metal. • Amorphous Co promotes CO disproportionation. • Carbon shells around the amorphous metal particles after the CO hydrogenation. - Abstract: Carbon nanotubes (CNTs) with different degree of surface oxidation were used as supports for 5 wt.% Co catalysts. CNTs and Co/CNT catalysts were analyzed by XPS, nitrogen adsorption, TEM and electron diffraction to reveal their structure. High oxidation degree of CNT surface (8.6 at.% of O) and low Co loading led to predominantly amorphous Co species. This resulted in the absence of catalytic activity in both CO and CO{sub 2} hydrogenation in opposite to the catalyst supported on less oxidized CNTs (5.4 at.% of O) where Co species were found to be crystalline. Thermal treatment of inactive catalyst in H{sub 2} and He led to the formation of Co crystal phase which was active in catalysis. Co particle size in catalyst supported on strongly oxidized CNTs was unchanged during CO hydrogenation in opposite to Co supported on less oxidized CNTs. Carbon shell formation on the surface of amorphous Co particles during CO hydrogenation was revealed, which testified CO disproportionation. Qualitative mechanism of CO hydrogenation on small Co particles was proposed.

CO2 capture by ionic liquids - an answer to anthropogenic CO2 emissions?

Science.gov (United States)

Sanglard, Pauline; Vorlet, Olivier; Marti, Roger; Naef, Olivier; Vanoli, Ennio

2013-01-01

Ionic liquids (ILs) are efficient solvents for the selective removal of CO2 from flue gas. Conventional, offthe-shelf ILs are limited in use to physisorption, which restricts their absorption capacity. After adding a chemical functionality like amines or alcohols, absorption of CO2 occurs mainly by chemisorption. This greatly enhances CO2 absorption and makes ILs suitable for potential industrial applications. By carefully choosing the anion and the cation of the IL, equimolar absorption of CO2 is possible. This paper reviews the current state of the art of CO2 capture by ILs and presents the current research in this field performed at the ChemTech Institute of the Ecole d'Ingénieurs et d'Architectes de Fribourg.

Estimating CO{sub 2} Emission Reduction of Non-capture CO{sub 2} Utilization (NCCU) Technology

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Hyun; Lee, Dong Woog; Gyu, Jang Se; Kwak, No-Sang; Lee, In Young; Jang, Kyung Ryoung; Shim, Jae-Goo [KEPCO Research Institute, Daejon (Korea, Republic of); Choi, Jong Shin [Korea East-West Power Co., LTD(ETP), Ulsan (Korea, Republic of)

2015-10-15

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

Possible use of Fe/CO2 fuel cells for CO2 mitigation plus H2 and electricity production

International Nuclear Information System (INIS)

Rau, Greg H.

2004-01-01

The continuous oxidation of scrap iron in the presence of a constant CO 2 -rich waste gas stream and water is evaluated as a means of sequestering anthropogenic CO 2 as well as generating hydrogen gas and electricity. The stoichiometry of the net reaction, Fe 0 + CO 2 + H 2 O → FeCO 3 + H 2 , and assumptions about reaction rates, reactant and product prices/values and overhead costs suggest that CO 2 might be mitigated at a net profit in excess of $30/tonne CO 2 . The principle profit center of the process would be hydrogen production, alone providing a gross income of >$160/tonne CO 2 reacted. However, the realization of such fuel cell economics depends on a number of parameters including: (1) the rate at which the reaction can be sustained, (2) the areal and volumetric density with which H 2 and electricity can be produced, (3) the purity of the H 2 produced, (4) the transportation costs of the reactants (Fe, CO 2 and H 2 O) and products (FeCO 3 or Fe(HCO 3 ) 2 ) to/from the cells and (5) the cost/benefit trade-offs of optimizing the preceding variables in a given market and regulatory environment. Because of the carbon intensity of conventional iron metal production, a net carbon sequestration benefit for the process can be realized only when waste (rather than new) iron and steel are used as electrodes and/or when Fe(HCO 3 ) 2 is the end product. The used electrolyte could also provide a free source of Fe 2+ ions for enhancing iron-limited marine photosynthesis and, thus, greatly increasing the CO 2 sequestration potential of the process. Alternatively, the reaction of naturally occurring iron oxides (iron ore) with CO 2 can be considered for FeCO 3 formation and sequestration, but this foregoes the benefits of hydrogen and electricity production. Use of Fe/CO 2 fuel cells would appear to be particularly relevant for fossil fuel gasification/steam reforming systems given the highly concentrated CO 2 they generate and given the existing infrastructure they

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

Science.gov (United States)

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

2017-11-14

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

UN PROYECTO CON UN FUTURO AMBIENTAL, ECONÓMICO Y SOCIAL INCIERTO

Directory of Open Access Journals (Sweden)

Luis Felipe Granada Aguirre

2005-01-01

Full Text Available La evaluación del uso de la energía neta, el costo del impacto de las emisiones vehiculares de dióxido de carbono (CO2 y de otros contaminantes, el costo de usar caña de azúcar para obtener etanol como un combustible automotor alternativo, se está realizando con base en su ciclo de vida, es decir, desde la cuna, producción de caña de azúcar, hasta el uso del etanol en motores de combustión interna, que sería la muerte. Se deben proponer nuevos indicadores FM (figure Merit para establecer criterios de calidad en la gasolina convencional (CG como en la mezclada con etanol obtenido de caña de azúcar SCE (sugar-cane-etanol con el fin de contabilizar el consumo de materias primas, el rendimiento neto del uso de la energía, de suelo, el impacto por las emisiones de CO2, NOx, SOx, THC, PM10, PM2.5, VOC residuos sólidos, vinazas, la variación de la morbilidad, el efecto en los motores de combustión interna y el costo de producción. La bondad del proyecto de alcohol carburante para Colombia se resume en seis puntos.

A common behaviour of thermoelectric layered cobaltites: incommensurate spin density wave states in [Ca2Co4/3Cu2/3O4]0.62[CoO2] and [Ca2CoO3]0.62[CoO2

International Nuclear Information System (INIS)

Sugiyama, J; Brewer, J H; Ansaldo, E J; Itahara, H; Dohmae, K; Xia, C; Seno, Y; Hitti, B; Tani, T

2003-01-01

Magnetism of a misfit layered cobaltite [Ca 2 Co 4/3 Cu 2/3 O 4 ] x RS [CoO 2 ] (x ∼ 0.62, RS denotes a rocksalt-type block) was investigated by a positive muon spin rotation and relaxation (μ + SR) experiment. A transition to an incommensurate (IC) spin density wave (SDW) state was found below 180 K (= T C on ); and a clear oscillation due to a static internal magnetic field was observed below 140 K(= T C ). Furthermore, an anisotropic behaviour of the zero-field μ + SR experiment indicated that the IC-SDW lies in the a-b plane, with oscillating moments directed along the c axis. These results were quite similar to those for the related compound [Ca 2 CoO 3 ] 0.62 RS [CoO 2 ], i.e., Ca 3 Co 4 O 9 . Since the IC-SDW field in [Ca 2 Co 4/3 Cu 2/3 O 4 ] 0.62 RS [CoO 2 ] was approximately the same as those in pure and doped [Ca 2 CoO 3 ] 0.62 RS [CoO 2 ], it was concluded that the IC-SDW exists in the [CoO 2 ] planes

Estado actual del bosque de polylepis y su eficiencia en la captura de CO2 en la provincia de Tarata, departamento de Tacna

OpenAIRE

Morales Aranibar, Luis Fortunato

2014-01-01

La presente investigación tuvo como objetivo evaluar las poblaciones actuales de Polylepis y su eficiencia en la captura de CO2 en la Provincia de Tarata (Susapaya, Estique Pueblo, Tarucachi, Sitajara, Ticaco y Tarata). Se establecieron parcelas de 25 x 20 m. (0, 1 ha.); ubicado al azar con la ayuda de estacas, rafia y brújula; luego se levanto información del estado actual para luego calcular su eficiencia de captura de CO2. En una área de 453 km2; la capacidad de captación de CO2 es d...

CO2 sensing and CO2 regulation of stomatal conductance: advances and open questions

Science.gov (United States)

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

2015-01-01

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

Carbon-14 exchange between CO2 and CO in the system 14CO2-CO-NOsub(x)(Ar, N2, O2)-quartz vessels

International Nuclear Information System (INIS)

Wawer, A.; Zielinski, M.

1981-01-01

It has been established that the rate of 14 C exchange between CO 2 and CO is diminished in presence of NO and NO 2 . The temperature dependence of the overall rate of exchange and the partial orders in respect to separate components of the exchange mixtures have been determined. The rate dependence on quartz surface has been established and the surface mechanism considered. The inhibiting action NO and NO 2 is explained. At higher pressures the catalytic effect of NO was found and explained. (author)

Promoting Ethylene Selectivity from CO2 Electroreduction on CuO Supported onto CO2 Capture Materials.

Science.gov (United States)

Yang, Hui-Juan; Yang, Hong; Hong, Yu-Hao; Zhang, Peng-Yang; Wang, Tao; Chen, Li-Na; Zhang, Feng-Yang; Wu, Qi-Hui; Tian, Na; Zhou, Zhi-You; Sun, Shi-Gang

2018-03-09

Cu is a unique catalyst for CO 2 electroreduction, since it can catalyze CO 2 reduction to a series of hydrocarbons, alcohols, and carboxylic acids. Nevertheless, such Cu catalysts suffer from poor selectivity. High pressure of CO 2 is considered to facilitate the activity and selectivity of CO 2 reduction. Herein, a new strategy is presented for CO 2 reduction with improved C 2 H 4 selectivity on a Cu catalyst by using CO 2 capture materials as the support at ambient pressure. N-doped carbon (N x C) was synthesized through high-temperature carbonization of melamine and l-lysine. We observed that the CO 2 uptake capacity of N x C depends on both the microporous area and the content of pyridinic N species, which can be controlled by the carbonization temperature (600-800 °C). The as-prepared CuO/N x C catalysts exhibit a considerably higher C 2 H 4 faradaic efficiency (36 %) than CuO supported on XC-72 carbon black (19 %), or unsupported CuO (20 %). Moreover, there is a good linear relationship between the C 2 H 4 faradaic efficiency and CO 2 uptake capacity of the supports for CuO. The local high CO 2 concentration near Cu catalysts, created by CO 2 capture materials, was proposed to increase the coverage of CO intermediate, which is favorable for the coupling of two CO units in the formation of C 2 H 4 . This study demonstrates that pairing Cu catalysts with CO 2 capture supports is a promising approach for designing highly effective CO 2 reduction electrocatalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A fine-tuned fluorinated MOF addresses the needs for trace CO2 removal and air capture using physisorption.

KAUST Repository

Bhatt, Prashant; Belmabkhout, Youssef; Cadiau, Amandine; Adil, Karim; Shekhah, Osama; Shkurenko, Aleksander; Barbour, Leonard J.; Eddaoudi, Mohamed

2016-01-01

The development of functional solid-state materials for carbon capture at low carbon dioxide (CO2) concentrations, from con-fined spaces (<0.5 %) and particularly from air (400 ppm), is of prime importance with respect to energy and environment sustainability. Herein, we report the deliberate construction of a hydrolytically stable fluorinated metal-organic framework (MOF), NbOFFIVE-1-Ni, with the proper pore system (size, shape and functionality), ideal for efficient and effective traces carbon dioxide removal. Markedly, the CO2-selective NbOFFIVE-1-Ni exhibits the highest CO2 gravimetric and volumetric uptake (ca. 1.3 mmol/g and 51.4 cm3.cm-3) for physical adsorbents at 400 ppm CO2 and 298 K. Practically, the NbOFFIVE-1-Ni affords the complete CO2 desorption at 328 K under vacuum with an associated moderate energy input of 54 kJ/mol, typical for the full CO2 desorption in reference physical adsorbents but considerably lower than the conventional chemical sorbents. Noticeably, the contracted square-like channels, affording the close proximity of the fluorine centers, permitted the enhancement of the CO2-framework interactions and subsequently the attainment of an unprecedented CO2-selectivity at very low CO2 concentrations. The precise localization of the adsorbed CO2 at the vicinity of the periodically aligned fluorine centers, promoting the selective adsorption of CO2, is evidenced by the single-crystal X-ray diffraction study on the NbOFFIVE-1-Ni hosting CO2 molecules. Cyclic CO2/N2 mixed-gas column breakthrough experiments under dry and humid conditions corroborate the excellent CO2-selectivity under practical carbon capture conditions. Pertinently, the no-table hydrolytic stability positions the NbOFFIVE-1-Ni as the new benchmark adsorbent for direct air capture and CO2 removal from confined spaces.

A fine-tuned fluorinated MOF addresses the needs for trace CO2 removal and air capture using physisorption.

KAUST Repository

Bhatt, Prashant

2016-07-08

The development of functional solid-state materials for carbon capture at low carbon dioxide (CO2) concentrations, from con-fined spaces (<0.5 %) and particularly from air (400 ppm), is of prime importance with respect to energy and environment sustainability. Herein, we report the deliberate construction of a hydrolytically stable fluorinated metal-organic framework (MOF), NbOFFIVE-1-Ni, with the proper pore system (size, shape and functionality), ideal for efficient and effective traces carbon dioxide removal. Markedly, the CO2-selective NbOFFIVE-1-Ni exhibits the highest CO2 gravimetric and volumetric uptake (ca. 1.3 mmol/g and 51.4 cm3.cm-3) for physical adsorbents at 400 ppm CO2 and 298 K. Practically, the NbOFFIVE-1-Ni affords the complete CO2 desorption at 328 K under vacuum with an associated moderate energy input of 54 kJ/mol, typical for the full CO2 desorption in reference physical adsorbents but considerably lower than the conventional chemical sorbents. Noticeably, the contracted square-like channels, affording the close proximity of the fluorine centers, permitted the enhancement of the CO2-framework interactions and subsequently the attainment of an unprecedented CO2-selectivity at very low CO2 concentrations. The precise localization of the adsorbed CO2 at the vicinity of the periodically aligned fluorine centers, promoting the selective adsorption of CO2, is evidenced by the single-crystal X-ray diffraction study on the NbOFFIVE-1-Ni hosting CO2 molecules. Cyclic CO2/N2 mixed-gas column breakthrough experiments under dry and humid conditions corroborate the excellent CO2-selectivity under practical carbon capture conditions. Pertinently, the no-table hydrolytic stability positions the NbOFFIVE-1-Ni as the new benchmark adsorbent for direct air capture and CO2 removal from confined spaces.

Potencial de Captura de CO2 asociado al componente edáfico en páramos Guantiva-La Rusia, departamento de Boyacá, Colombia

Directory of Open Access Journals (Sweden)

Karen Lisseth Africano Pérez

2016-06-01

Full Text Available Los páramos son considerados escenarios importantes para la mitigación del impacto del cambio climático, ya que sus suelos pueden capturar y secuestrar CO2, uno de los principales gases de efecto invernadero. Con el fin de determinar el efecto que causan las actividades antrópicas sobre la capacidad de captura de CO2 se usaron parcelas permanentes de muestreo (PPM ubicadas en un área intervenida antropicamente (agricultura intensiva sin tecnificar y ganadería extensiva, no intervenida y en recuperación, en el complejo de páramos de Guantiva-La Rusia (Boyacá. La PPM en recuperación mostró mayor capacidad de captura con un valor promedio de 872,26 ton ha-1 en contraste la PPM con menor capacidad fue la intervenida con valor promedio de 221,70 ton ha-1, esto evidencia el efecto negativo que ejerce la actividad antrópica sobre la capacidad de captura de carbono de estos suelos, y el papel que juegan estos ecosistemas como sumideros de carbono y por ende la importancia de su protección y conservación.

The Li–CO2 battery: a novel method for CO2 capture and utilization

KAUST Repository

Xu, Shaomao

2013-01-01

We report a novel primary Li-CO2 battery that consumes pure CO2 gas as its cathode. The battery exhibits a high discharge capacity of around 2500 mA h g-1 at moderate temperatures. At 100 °C the discharge capacity is close to 1000% higher than that at 40 °C, and the temperature dependence is significantly weaker for higher surface area carbon cathodes. Ex-situ FTIR and XRD analyses convincingly show that lithium carbonate (Li2CO3) is the main component of the discharge product. The feasibility of similar primary metal-CO2 batteries based on earth abundant metal anodes, such as Al and Mg, is demonstrated. The metal-CO2 battery platform provides a novel approach for simultaneous capturing of CO2 emissions and producing electrical energy. © 2013 The Royal Society of Chemistry.

The Influence of CO2 Solubility in Brine on Simulation of CO2 Injection into Water Flooded Reservoir and CO2 WAG

DEFF Research Database (Denmark)

Yan, Wei; Stenby, Erling Halfdan

2010-01-01

Injection of CO2 into depleted oil reservoirs is not only a traditional way to enhance oil recovery but also a relatively cheaper way to sequester CO2 underground since the increased oil production can offset some sequestration cost. CO2 injection process is often applied to water flooded...... simulations were made for seven oil samples within a wide range of temperature, pressure and salinity. The results were analyzed in terms of the change in oil recovery due to different phase equilibrium descriptions, the delay in breakthrough and the CO2 lost to the aqueous phase. The influence of different...

Evaluation of 59Co(n,γ)60Co, 59Co(n,2n)58Co, 59Co(nα)56Mn, for ENDF/B-IV

International Nuclear Information System (INIS)

Krieger, T.J.; Smith, A.B.; Smith, D.L.; Jenkins, J.D.

1975-01-01

The present evaluation of 59 Co (n,γ) for ENDF/B IV consists of two parts, an evaluation below 100 keV by T. J. Krieger, Brookhaven National Laboratory, and one above 100 keV by A. B. Smith and D. L. Smith, Argonne National Laboratory

Triazine containing N-rich microporous organic polymers for CO2 capture and unprecedented CO2/N2 selectivity

International Nuclear Information System (INIS)

Bhunia, Subhajit; Bhanja, Piyali; Das, Sabuj Kanti; Sen, Tapas; Bhaumik, Asim

2017-01-01

Targeted synthesis of microporous adsorbents for CO 2 capture and storage is very challenging in the context of remediation from green house gases. Herein we report two novel N-rich microporous networks SB-TRZ-CRZ and SB-TRZ-TPA by extensive incorporation of triazine containing tripodal moiety in the porous polymer framework. These materials showed excellent CO 2 storage capacities: SB-TRZ-CRZ displayed the CO 2 uptake capacity of 25.5 wt% upto 1 bar at 273 K and SB-TRZ-TPA gave that of 16 wt% under identical conditions. The substantial dipole quadruple interaction between network (polar triazine) and CO 2 boosts the selectivity for CO 2 /N 2 . SB-TRZ-CRZ has this CO 2 /N 2 selectivity ratio of 377, whereas for SB-TRZ-TPA it was 97. Compared to other porous polymers, these materials are very cost effective, scalable and very promising material for clean energy application and environmental issues. - Graphical abstract: We report two novel N-rich microporous polymeric materials by doping of triazine containing tripodal dopant in the organic framework. These materials showed excellent CO 2 storage capacities as high as 25.5 wt% under 1 bar pressure with exceptional CO 2 /N 2 selectivity of 377. - Highlights: • Triazine containing trimodal moiety incorporated in polycarbazolic and poly triphenylamine networks. • N-rich crosslinked polymers with high BET surface area and 1.5–1.7 nm size large micropores. • CO 2 uptake capacity of 25.5 wt% upto 1 bar at 273 K. • These crosslinked porous polymers showed exceptional CO 2 /N 2 selectivity.

CO{sub 2} uptake by the Kalanchoe plant; CO{sub 2}-opname bij Kalanchoe

Energy Technology Data Exchange (ETDEWEB)

Verberkt, H.

1994-01-01

The results of a study on the assimilation of the Kalanchoe plant are presented. The aim of the study is to determine the optimal time period of a natural day (24 hours) to supply carbon dioxide to a Kalanchoe plant. A Kalanchoe plant originally is a so-called CAM (Crassulacean Acid Metabolism) plant: CO{sub 2} uptake at night and chemical conversion of CO{sub 2} into malic acid. By day the fixed CO{sub 2} is used for photosynthesis. It appears that a Kalanchoe plant also takes up CO{sub 2} by day, which is directly used for photosynthesis. For Dutch horticulture conditions (20C, sufficient moisture) extra CO{sub 2} supply by day in the spring results in an increase of both the fresh weight and the dry weight compared to no extra CO{sub 2} supply. 10 figs., 3 tabs., 19 refs., 4 appendices

Novel Co(III)/Co(II) mixed valence compound [Co(bapen)Br2]2[CoBr4] (bapen = N,N‧-bis(3-aminopropyl)ethane-1,2-diamine): Synthesis, crystal structure and magnetic properties

Science.gov (United States)

Smolko, Lukáš; Černák, Juraj; Kuchár, Juraj; Miklovič, Jozef; Boča, Roman

2016-09-01

Green crystals of Co(III)/Co(II) mixed valence compound [Co(bapen)Br2]2[CoBr4] (bapen = N,N‧-bis(3-aminopropyl)ethane-1,2-diamine) were isolated from the aqueous system CoBr2 - bapen - HBr, crystallographically studied and characterized by elemental analysis and IR spectroscopy. Its ionic crystal structure is built up of [Co(bapen)Br2]+ cations and [CoBr4]2- anions. The Co(III) central atoms within the complex cations are hexacoordinated (donor set trans-N4Br2) with bromido ligands placed in the axial positions. The Co(II) atoms exhibit distorted tetrahedral coordination. Beside ionic forces weak Nsbnd H⋯Br intermolecular hydrogen bonding interactions contribute to the stability of the structure. Temperature variable magnetic measurements confirm the S = 3/2 behavior with the zero-field splitting of an intermediate strength: D/hc = 8.7 cm-1.

CO2 as a refrigerant

CERN Document Server

2014-01-01

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

Efecto del co2 en la velocidad de combustión de semicoques de carbón en aplicaciones de oxi-combustión

OpenAIRE

MOLINA, ALEJANDRO; SHADDIX, C. R.

2009-01-01

Un reactor de flujo de arrastre equipado con un equipo que permite la medición del tamaño y temperatura de las partículas de carbón se utilizó para determinar la cinética de combustión de semicoques de carbón pulverizado oxidados en mezclas en mezclas con distintas concentraciones de oxígeno en ambiente de N2 o CO2. Esta información es importante para entender y simular la combustión de carbón en ambiente enriquecido de oxígeno y con recirculado de gases de combustión, tecnología promisor...

Field demonstration of CO2 leakage detection in potable aquifers with a pulselike CO2-release test.

Science.gov (United States)

Yang, Changbing; Hovorka, Susan D; Delgado-Alonso, Jesus; Mickler, Patrick J; Treviño, Ramón H; Phillips, Straun

2014-12-02

This study presents two field pulselike CO2-release tests to demonstrate CO2 leakage detection in a shallow aquifer by monitoring groundwater pH, alkalinity, and dissolved inorganic carbon (DIC) using the periodic groundwater sampling method and a fiber-optic CO2 sensor for real-time in situ monitoring of dissolved CO2 in groundwater. Measurements of groundwater pH, alkalinity, DIC, and dissolved CO2 clearly deviated from their background values, showing responses to CO2 leakage. Dissolved CO2 observed in the tests was highly sensitive in comparison to groundwater pH, DIC, and alkalinity. Comparison of the pulselike CO2-release tests to other field tests suggests that pulselike CO2-release tests can provide reliable assessment of geochemical parameters indicative of CO2 leakage. Measurements by the fiber-optic CO2 sensor, showing obvious leakage signals, demonstrated the potential of real-time in situ monitoring of dissolved CO2 for leakage detection at a geologic carbon sequestration (GCS) site. Results of a two-dimensional reactive transport model reproduced the geochemical measurements and confirmed that the decrease in groundwater pH and the increases in DIC and dissolved CO2 observed in the pulselike CO2-release tests were caused by dissolution of CO2 whereas alkalinity was likely affected by carbonate dissolution.

Carbon dioxide vs. air insufflation in ileo-colonoscopy and in gastroscopy plus ileo-colonoscopy: a comparative study Insuflación de CO2 vs. aire en íleo-colonoscopia y en gastroscopia más íleo-colonoscopia: estudio comparativo

Directory of Open Access Journals (Sweden)

María Fernández-Calderón

2012-05-01

Full Text Available Introduction: insufflation with carbon dioxide (CO2 during endoscopies compared to air is associated with a decrease in abdominal discomfort after the examination, because CO2 is readily absorbed through the small intestine and eliminated by the lungs. Aims: the objective of this randomized clinical trial was to assess the effect of CO2 insufflation on pain and abdominal distension after an ileo-colonoscopy (I and after an ileo-colonoscopy plus gastroscopy (I+G. Material and methods: we included a total of 309 patients in the study and all endoscopies were performed under sedation with propofol. Two hundred fourteen patients underwent an I (132 with CO2 / 82 with air and 95 underwent an I+G (53 with CO2 / 42 with air. Abdominal pain was studied at 10, 30 and 120 minutes of exploration and abdominal perimeter difference before and after the procedure. Results: both in group I and in group I+G, the use of CO2 translated into an average of abdominal pain significantly lower (p Introducción: la insuflación con dióxido de carbono (CO2 durante las endoscopias digestivas comparado con el aire, se asocia a una disminución de las molestias abdominales después de la exploración, ya que el CO2 es fácilmente absorbido por el intestino delgado y eliminado por los pulmones. Objetivo: el objetivo de este ensayo clínico aleatorizado fue valorar el efecto de la insuflación de CO2 sobre el dolor y la distensión abdominal después de una ileo-colonoscopia (I y después de una íleo-colonoscopia + gastroscopia (I+G. Material y métodos: se incluyeron un total de 309 pacientes en el estudio y todas las endoscopias fueron realizadas bajo sedación con propofol. A 214 pacientes se les realizó una I (132 con CO2 / 82 con aire y a 95 se les realizó una I+G (53 con CO2 / 42 con aire. Se estudió el dolor abdominal a los 10, 30 y 120 min de la exploración y la diferencia de perímetro abdominal antes y después del procedimiento. Resultados: tanto en el grupo

Características de la combustión con aire enriquecido con oxígeno y perspectivas de aplicación en PYME con procesos de alta temperatura

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Juan Carlos González Palencia

2009-09-01

Full Text Available Las pequeñas y medianas empresas (PYME con procesos de alta temperatura, como la fundición y los tratamientos térmicos, son de gran importancia social y económica en los países en vía de desarrollo, siendo necesario aumentar su competitividad para garantizar su permanencia en el mercado. Dado que estas empresas son intensivas en el consumo de energía térmica, su competitividad se ve afectada por la obsolescencia y baja eficiencia de los sistemas de combustión, por lo que es necesaria la investigación y divulgación de nuevas tecnologías. Teniendo esto en mente, se presenta una revisión del estado del arte de la combustión con aire enriquecido con oxígeno (OEC, resaltando sus ventajas ambientales y productivas. Con el objetivo de mostrar su potencial se presenta un caso de aplicación a la fusión de latón en un horno autorregenerativo para el que se obtie- nen reducciones de consumo de combustible, tiempo de proceso y emisiones contaminantes de CO2 total equivalente del 28, 43 y 34% respectivamente y un incremento del 30% en la eficiencia al aumentar el contenido de O2 en el comburente de 21 a 35%. Sin embargo, el incremento del costo asociado al suministro de O2 representa un obstáculo para la penetración de esta tecnología.

Reconsideration of atmospheric CO2 lifetime: potential mechanism for explaining CO2 missing sink

Science.gov (United States)

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

2009-04-01

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

Dynamics of soil CO2 efflux under varying atmospheric CO2 concentrations reveal dominance of slow processes.

Science.gov (United States)

Kim, Dohyoung; Oren, Ram; Clark, James S; Palmroth, Sari; Oishi, A Christopher; McCarthy, Heather R; Maier, Chris A; Johnsen, Kurt

2017-09-01

We evaluated the effect on soil CO 2 efflux (F CO 2 ) of sudden changes in photosynthetic rates by altering CO 2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO 2 (eCO 2 ) ranging 1.0-1.8 times ambient did not affect F CO 2 . F CO 2 did not decrease until 4 months after termination of the long-term eCO 2 treatment, longer than the 10 days observed for decrease of F CO 2 after experimental blocking of C flow to belowground, but shorter than the ~13 months it took for increase of F CO 2 following the initiation of eCO 2 . The reduction of F CO 2 upon termination of enrichment (~35%) cannot be explained by the reduction of leaf area (~15%) and associated carbohydrate production and allocation, suggesting a disproportionate contraction of the belowground ecosystem components; this was consistent with the reductions in base respiration and F CO 2 -temperature sensitivity. These asymmetric responses pose a tractable challenge to process-based models attempting to isolate the effect of individual processes on F CO2 . © 2017 John Wiley & Sons Ltd.

Variability in soil CO2 production and surface CO2 efflux across riparian-hillslope transitions

Science.gov (United States)

Vincent Jerald. Pacific

2007-01-01

The spatial and temporal controls on soil CO2 production and surface CO2 efflux have been identified as an outstanding gap in our understanding of carbon cycling. I investigated both the spatial and temporal variability of soil CO2 concentrations and surface CO2 efflux across eight topographically distinct riparian-hillslope transitions in the ~300 ha subalpine upper-...

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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

International Nuclear Information System (INIS)

Kheshgi, Haroon S.

2004-01-01

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

Efecto del 100 % de CO2 en la textura de rebanadas de lomo de atún rojo (Thunnus sp. almacenadas en congelación

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Myrna Luisa Medina Bracamonte

2017-07-01

Full Text Available l lomo de atún rojo se comercializa congelado, proceso que favorece su endurecimiento y más durante el almacenamiento. El Empacado en Atmósfera Modificada es una alternativa para incrementar la vida útil de productos alimenticios en el almacenamiento a bajas temperaturas. Se ha recomendado la atmósfera de 100 % de CO2 para el lomo atún almacenado en refrigeración, sin embargo se busca una vida útil de meses para su comercialización. Por ello se planteó evaluar el efecto de la atmósfera de 100 % de CO2 sobre la textura de rebanadas de lomo de atún rojo, congeladas, durante su almacenamiento a -10 y -18 ºC. Las rebanadas individuales de lomo de atún rojo procesadas según Medina-Bracamonte et al. (2014 se empacaron en atmósfera de 100 % de CO2. Se aplicó un Análisis del Perfil de Textura a 0, 15, 30, 54 y 111 días de almacenamiento a cubos de 1 cm3 de las rebanadas, descongeladas y a temperatura ambiental, con un analizador de textura con un émbolo de 75 mm de diámetro, previamente calibrado con una celda de 5 kg y usando el software Texture Expert Exceed, versión 2.54. La atmósfera de 100 % de CO2 a -10 ºC redujo significativamente (p < 0,05 la dureza y masticabilidad de las rebanadas de lomo de atún rojo, y a -18 ºC fue el tratamiento que mostró menor incremento de la cohesividad.

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

International Nuclear Information System (INIS)

Bouchemoua, A.

2012-01-01

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

Autopsia verbal en hombres adultos con diabetes tipo 2: estudio cualitativo

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Geu Mendoza-Catalán

2017-09-01

Full Text Available Introducción: La diabetes mellitus tipo 2 (DMT2 es un padecimiento crónico cuya incidencia se incrementa en forma alarmante. El objetivo fue identificar los factores asociados al no autocuidado en hombres con muerte prematura y diagnóstico de DMT2. Materiales y Métodos: Se realizaron seis entrevistas cualitativas a familiares de hombres con DMT2 que fallecieron por complicaciones de su enfermedad, utilizando la metodología de la autopsia verbal. Los resultados se analizaron mediante el análisis de contenido. Resultados: Dentro de los factores que surgieron como limitantes para el autocuidado fueron: la negación de la DMT2, el trabajo, el machismo, preferencia en los alimentos, apoyo familiar, el consumo de alcohol, el consumo de tabaco y la depresión. Discusión: Los hombres con DMT2 se ven influenciados por diversas circunstancias que limitan cuidarse, atenderse y por consiguiente presentar desventajas de salud, complicaciones e incluso una muerte temprana. Conclusiones: Desde la perspectiva de enfermería los resultados ayudan a comprender el comportamiento de los hombres ante esta enfermedad en donde se requiere cuidado constante, a la par que una conciencia legítima de que no se deja de ser hombre por cuidarse.  Cómo citar este artículo: Mendoza-Catalán G, Gallegos-Cabriales EC, Figueroa-Perea JG. Autopsia verbal en hombres adultos con diabetes tipo 2: estudio cualitativo. Rev Cuid. 2017; 8(3: 1786-98. http://dx.doi.org/10.15649/cuidarte.v8i3.420

Advances in Geological CO{sub 2} Sequestration and Co-Sequestration with O{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Verba, Circe A; O& #x27; Connor, William K.; Ideker, J.H.

2012-10-28

The injection of CO{sub 2} for Enhanced Oil Recovery (EOR) and sequestration in brine-bearing formations for long term storage has been in practice or under investigation in many locations globally. This study focused on the assessment of cement wellbore seal integrity in CO{sub 2}- and CO{sub 2}-O{sub 2}-saturated brine and supercritical CO{sub 2} environments. Brine chemistries (NaCl, MgCl{sub 2}, CaCl{sub 2}) at various saline concentrations were investigated at a pressure of 28.9 MPa (4200 psi) at both 50{degree}C and 85{degree}C. These parameters were selected to simulate downhole conditions at several potential CO{sub 2} injection sites in the United States. Class H portland cement is not thermodynamically stable under these conditions and the formation of carbonic acid degrades the cement. Dissociation occurs and leaches cations, forming a CaCO{sub 3} buffered zone, amorphous silica, and other secondary minerals. Increased temperature affected the structure of C-S-H and the hydration of the cement leading to higher degradation rates.

Ocean CO{sub 2} disposal

Energy Technology Data Exchange (ETDEWEB)

Shindo, Yuji; Hakuta, Toshikatsu [National Inst. of Materials and Chemical Research, AIST, MITI, Higashi, Tsukuba, Ibaraki (Japan)

1993-12-31

Most countries in the world will continue to depend on fossil fuels for their main energy at least for half a country, even in the confrontation with the threat of global warming. This indicates that the development of CO{sub 2} removal technologies such as recovering CO{sub 2} from flue gases and sequestering it of in the deep oceans or subterranean sites is necessary, at least until non-fossil fuel dependent society is developed. Ocean CO{sub 2} disposal is one of the promising options for the sequestration of CO{sub 2} recovered from flue gases. Oceans have sufficient capacity to absorb all the CO{sub 2} emitted in the world. It is very significant to research and develop the technologies for ocean CO{sub 2} disposal.

Uso de selección asistida con marcadores para resistencia a antracnosis en fríjol común

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Garzón Luz Nayibe

2007-12-01

Full Text Available

La antracnosis causada por Colletotrichum lindemuthianum puede llegar a generar pérdidas hasta del 95% de la producción en fríjol (Phaseolus vulgaris L., por eso es considerada una de las enfermedades más limitantes. Con el presente trabajo se inició un programa de mejoramiento utilizando selección asistida por marcadores. Se usó como parental resistente el cultivar Mesoamericano G2333, para incorporar a fríjoles volubles comerciales de Colombia los genes Co-5 y Co-4² , que confieren resistencia a C. lindemuthianum. Se obtuvieron progenies RC₁F₁ provenientes de cruces entre G2333 y siete parentales volubles tipo Bola roja y Rojo moteado cultivados en zonas productoras de fríjol de Cundinamarca y Boyacá. La selección de plantas RC₁F₁ se realizó con los marcadores moleculares SCAR SAB3 y SAS13, ligados a los genes Co-5 y Co-4² , respectivamente. En la evaluación genotípica de 1.271 plantas RC₁F₁, 608 amplificaron con SAB3 y 603 con SAS13. La segregación para cada marcador se ajustó a la razón 1:1 esperada en pruebas de chi-cuadrado (X² = 2,38, P= 0,12 para SAB3 y X² = 3,32, P= 0,07 para SAS13. Un total de 299 plantas RC₁F₁ amplificaron con ambos SCAR, ajustándose a la razón esperada (X²= 1,11, P= 0,78 y confirmando la segregación independiente. Estas plantas fueron seleccionadas para continuar el programa de mejoramiento, ya que se espera que porten los genes Co-5 y Co-4². Se logró implementar la selección asistida por marcadores para antracnosis, y acelerar la introducción y piramidación de genes de resistencia en fríjol de importancia económica en Colombia.

Energy recovery of the H{sub 2}S and CO{sub 2} elimination with technology by hybrid plasma; Recuperacion energetica de la eliminacion de H{sub 2}S y CO{sub 2} con tecnologia por plasma hibrido

Energy Technology Data Exchange (ETDEWEB)

Salazar T, J. A.

2014-07-01

This document is a research focused on energy recovery from acid gas removal contained in natural gas as hydrogen sulfide (H{sub 2}S) and carbon dioxide (CO{sub 2}), by obtaining highly energetic gas such as syngas (mixture of hydrogen and carbon monoxide, in particular) using plasma technology in its hybrid form, namely, gliding arc plasma, that has the property to behave like a thermal plasma and cold plasma, besides possessing among other virtues the ability to treat large flows continuously at atmospheric pressure without the need of using noble gases, with a power consumption of no more than 1000 W. Furthermore, this type of plasma has demonstrated to be a clean and efficient not only by high conversion rates of H{sub 2}S (86%) and CO{sub 2} (56%) and high percentages of selectivity in the production of hydrogen (H{sub 2}) and carbon monoxide carbon (CO) obtained in this work, but because it can even be seriously considered to replace other technologies currently used in the process of sweetening natural gas as adsorption, absorption and sequestering membranes. The results shown are based on a series of analysis, simulations, experiments and calculations, from the design of the plasma generating source based on an impulse-phase circuit, to the electrical characterization results and simulation by acquiring electrical signals, without forgetting the characterization of the resulting chemical components using various analytical techniques such as mass spectrometry, gas chromatography (GC), optical emission spectroscopy (OES), optical spectroscopy Fourier inverse transformed (XRD) and scanning electron microscopy (Sem), X-ray diffraction (XRD) and multi-gas detectors (iBrid MX6). Additionally, performed chemical kinetics and reaction mechanism of the compounds involved in the degradation of H{sub 2}S and CO{sub 2} similar to those experienced as well as the study of energy efficiency (Ece), specific energy (Se), all this to meet a projects needs 127499, entitled

CO2 emissions vs. CO2 responsibility: An input-output approach for the Turkish economy

International Nuclear Information System (INIS)

Ipek Tunc, G.; Tueruet-Asik, Serap; Akbostanci, Elif

2007-01-01

Recently, global warming (greenhouse effect) and its effects have become one of the hottest topics in the world agenda. There have been several international attempts to reduce the negative effects of global warming. The Kyoto Protocol can be cited as the most important agreement which tries to limit the countries' emissions within a time horizon. For this reason, it becomes important to calculate the greenhouse gas emissions of countries. The aim of this study is to estimate the amount of CO 2 -the most important greenhouse gas-emissions, for the Turkish economy. An extended input-output model is estimated by using 1996 data in order to identify the sources of CO 2 emissions and to discuss the share of sectors in total emission. Besides, 'CO 2 responsibility', which takes into account the CO 2 content of imports, is estimated for the Turkish economy. The sectoral CO 2 emissions and CO 2 responsibilities are compared and these two notions are linked to foreign trade volume. One of the main conclusions is that the manufacturing industry has the first place in both of the rankings for CO 2 emissions and CO 2 responsibilities, while agriculture and husbandry has the last place

Impacto del CO2 sobre la densidad celular en seis cepas de microalgas marinas

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Alberto I. Oscanoa Huaynate

2015-12-01

Full Text Available Debido a la gran facilidad con que las microalgas pueden capturar el CO2 del medio ambiente, resulta interesante evaluar la cantidad y tiempo de ingreso de éste a los cultivos masivos, con la fi nalidad de aumentar la densidad celular. El objetivo del presente estudio fue evaluar los tiempos de inyección del mencionado gas, durante la producción de biomasa que conlleve a una mayor densidad celular, evaluando además, la variación del pH sin alterar la calidad del cultivo. A partir de seis cepas obtenidas del Banco de Germoplasma del Instituto del Mar del Perú, se realizaron cultivos tipo batch de 300L en invernadero, el tiempo de cultivo de la fase exponencial donde se realizaron las pruebas fue de tres días. Los datos se procesaron mediante el análisis del parámetro pendiente de la regresión lineal. Los resultados mostraron que la densidad celular es inversamente proporcional al tiempo de inyección de CO2 al cultivo. La mayor densidad celular, en las diferentes cepas, se obtuvo a los 5min, excepto para las cepas Chaetoceros gracilisy Nannochloris maculata, las cuales obtienen la mayor densidad a los 10 y 15min, respectivamente. La variación de pH tendió hacia la acidez, en un rango de 8 a 4, sin alterar la densidad celular, por el contrario, los cultivos permanecieron libres de contaminantes. En conclusión, los resultados permiten establecer tiempos adecuados de inyección del CO2, los cuales fortalecen la fase de crecimiento exponencial aumentando la densidad poblacional en un 30% sobre lo establecido en esta fase.

Environmental potential of the use of CO_2 from alcoholic fermentation processes. The CO_2-AFP strategy

International Nuclear Information System (INIS)

Alonso-Moreno, Carlos; García-Yuste, Santiago

2016-01-01

A novel Carbon Dioxide Utilization (CDU) approach from a relatively minor CO_2 emission source, i.e., alcoholic fermentation processes (AFP), is presented. The CO_2 produced as a by-product from the AFP is estimated by examining the EtOH consumed per year reported by the World Health Organization in 2014. It is proposed that the extremely pure CO_2 from the AFP is captured in NaOH solutions to produce one of the Top 10 commodities in the chemical industry, Na_2CO_3, as a good example of an atomic economy process. The novel CDU strategy could yield over 30.6 Mt of Na_2CO_3 in oversaturated aqueous solution on using ca. 12.7 Mt of captured CO_2 and this process would consume less energy than the synthetic methodology (Solvay ammonia soda process) and would not produce low-value by-products. The quantity of Na_2CO_3 obtained by this strategy could represent ca. 50% of the world Na_2CO_3 production in one year. In terms of the green economy, the viability of the strategy is discussed according to the recommendations of the CO_2Chem network, and an estimation of the CO_2negative emission achieved suggests a capture of around 280.0 Mt of CO_2 from now to 2020 or ca. 1.9 Gt from now to 2050. Finally, the results obtained for this new CDU proposal are discussed by considering different scenarios; the CO_2 production in a typical winemaking corporation, the CO_2 released in the most relevant wine-producing countries, and the use of CO_2 from AFP as an alternative for the top Na_2CO_3-producing countries. - Highlights: • A new CDU strategy to mitigate the CO_2 in the atmosphere is assessed. • An environmental action towards negligible emission sources such as AFP. • The waste CO_2 from AFP could be converted into Na_2CO_3. • Capture 12.7 Mt yr"–"1 of CO_2 to generate ca. 1.9 Gt of CO_2negative emissions by 2050.

CO2 chemical valorization

International Nuclear Information System (INIS)

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

2014-07-01

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

The Determination of the Half-Life of U{sup 238} by Absolute Counting of {alpha} Particles in a 4 {pi}-Liquid Scintillation Counter; Determination de la periode de l'U{sup 238} au moyen du comptage absolu de particules {alpha} dans un comtpeur 4 {pi} a scintillateur liquide; Opredelenie perioda poluraspadda U{sup 238} posredstvom absolyutnogo scheta {alpha}-chastits v zhidkostnom stsintillyatsionnom schetchike 4 {pi}; Determinacion del periodo del U{sup 238} por recuento absoluto de las particulas {alpha} con un contador 4 {pi} de centelleador liquido

Energy Technology Data Exchange (ETDEWEB)

Steyn, J; Strelow, F W. E. [Council of Scientific and Industrial Research, Pretoria (South Africa)

1960-06-15

The specific activity of natural uranium was determined by liquid scintillation {alpha}-counting. Uranium was extracted from its decay products by methyl isobutyl ketone extraction and samples of this solution were added directly to the liquid scintillator. A quantitative investigation was made of the separation of uranium from thorium by the extraction method employed. Assuming that U{sup 238} and U{sup 234} were in equilibrium, and correcting for the presence of U{sup 235}, the specific activity and the half-life of the isotope U{sup 238} were calculated. (author) [French] L'activite specifique de l'uranium naturel est determinee au moyen d'un comptage a par scintillateur liquide. L'uranium est separe de ses produits de desintegration par une extraction a la methylisobutylceton e et des echantillons de cette solution sont ajoutes directement au scintillateur liquide. On fait une etude quantitative de la separation de l'uranium et du thorium par le procede d'extraction utilise. En admettant que U{sup 238} et U{sup 234} sont en equilibre et en faisant la correction voulue pour tenir compte de la presence de U{sup 235}, on calcule l'activite specifique et la periode de U{sup 238}. (author) [Spanish] La actividad especifica del uranio natural se determino con un contador {alpha} de centelleador liquido. El uranio se separo de productes de desintegracion por extraccion con metilisobutilcetona, y muestras de esta solucion se anadieron directamente al centelleador liquido. Se estudio cuantitativament e el grado de separacion uranio/torio alcanzado con el metodo de extraccion empleado. Introduciendo correcciones para tener en cuenta la presencia de U{sup 235}, se calculo la actividad especifica y el periodo de semidesintegracio n del U{sup 238} suponiendo que este isotopo se encontraba en equilibrio con el U{sup 234}. (author) [Russian] Spetsificheskaya aktivnost' estestvennogo urana byla opredelena s pomoshch'yu zhidkostnogo stsintillyatsionnog o schetchika {alpha

Simulasi Numeris Karakteristik Pembakaran CH4/CO2/Udara dan CH4/CO2/O2 pada Counterflow Premixed Burner

Directory of Open Access Journals (Sweden)

Hangga Wicaksono

2017-08-01

Full Text Available The high amount of CO2 produced in a conventional biogas reactor needs to be considered. A further analysis is needed in order to investigate the effect of CO2 addition especially in thermal and chemical kinetics aspect. This numerical study has been held to analyze the effect of CO2 in CH4/CO2/O­2 and CH4/CO2/Air premixed combustion. In this study one dimensional analisys in a counterflow burner has been performed. The volume fraction of CO2 used in this study was 0%-40% from CH4’s volume fraction, according to the amount of CO2 in general phenomenon. Based on the flammability limits data, the volume fraction of CH4 used was 5-61% in O2 environment and 5-15% in air environment. The results showed a decreasing temperature along with the increasing percentage of CO2 in each mixtures, but the effect was quite smaller especially in stoichiometric and lean mixture. CO2 could affects thermally (by absorbing heat due to its high Cp and also made the production of unburnt fuel species such as CO relatively higher.

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

Science.gov (United States)

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

Photosynthetic response to variation in CO2 concentrations and temperature of four broad-leaved trees in Beijing region

Institute of Scientific and Technical Information of China (English)

Zhibo MA; Shengqing SHI; Qinyan MA; Yutao WANG; Xingliang LIU

2008-01-01

Responses of the photosynthetic characteris-tics to variation in CO2 concentration and temperature of Ginkgo biloba, Eucornmia ulmoides, Magnolia denudata and Tiliajaponica were measured during the peak growing season. The results show that the ambient CO2 concentra-tion could not meet the requirements for photosynthesis of these four species. The optimal temperatures for pho-tosynthesis were lower than the average daytime air tem-perature. Hence, the photosynthesis of these four species was restricted by the low CO2 concentration and high daytime air temperature at the time of measurement. Marked enhancements in the net photosynthetic rate were found in all four species when the CO2 concentration was doubled. When the dependency on CO2 and temperature were examined simultaneously, it was seen that for increased CO2 concentrations there was a shift in the optimum temperature for M. denudata and T. japonica towards higher temperatures. Due to their independence on CO2 concentrations, this trend could not be found in the G. biloba and E. ulmoides data sets. The stomatal con-ductance (Gs) was sensitive to a vapor pressure deficit (VPD) which in turn was sensitive to temperature. An increase in temperature would cause the VPD to increase and plants might be assumed to react by reducing their stomatal apertures. The effect on stomatal resistance would be most significant at high temperatures. The restriction to stomatal conductance for these four species would increase if CO2 concentrations were elevated at the same temperature.

Recubrimientos superficiales con láseres de diodos de alta potencia

Directory of Open Access Journals (Sweden)

Molpeceres, J. L.

1998-04-01

Full Text Available Nowadays, high power diode laser systems are available in the market. These systems, based on arrays of small diode lasers, can achieve more than 1 kW of output power and are currently offering new possibilities in the field of laser material processing where CO₂ and Nd:YAG lasers were used up to the present. The results obtained in some materials cladding based on cobalt and nickel alloys as additional materials is presented. The instrumental set-up used in these experiments are described.

La posibilidad de disponer actualmente de láseres de diodos con una potencia de emisión óptica superior a 1 kW permite abordar un gran número de aplicaciones en el ámbito del procesado de materiales con láser, dominado tradicionalmente por los láseres de CO₂ y Nd:YAG. En el presente trabajo, se muestra la aplicación de los láseres de diodos de alta potencia al recubrimiento de materiales metálicos con aleaciones de base cobalto y níquel. Se describen las características del sistema empleado y se muestran los resultados obtenidos.

Dolomite decomposition under CO2

International Nuclear Information System (INIS)

Guerfa, F.; Bensouici, F.; Barama, S.E.; Harabi, A.; Achour, S.

2004-01-01

Full text.Dolomite (MgCa (CO 3 ) 2 is one of the most abundant mineral species on the surface of the planet, it occurs in sedimentary rocks. MgO, CaO and Doloma (Phase mixture of MgO and CaO, obtained from the mineral dolomite) based materials are attractive steel-making refractories because of their potential cost effectiveness and world wide abundance more recently, MgO is also used as protective layers in plasma screen manufacture ceel. The crystal structure of dolomite was determined as rhombohedral carbonates, they are layers of Mg +2 and layers of Ca +2 ions. It dissociates depending on the temperature variations according to the following reactions: MgCa (CO 3 ) 2 → MgO + CaO + 2CO 2 .....MgCa (CO 3 ) 2 → MgO + Ca + CaCO 3 + CO 2 .....This latter reaction may be considered as a first step for MgO production. Differential thermal analysis (DTA) are used to control dolomite decomposition and the X-Ray Diffraction (XRD) was used to elucidate thermal decomposition of dolomite according to the reaction. That required samples were heated to specific temperature and holding times. The average particle size of used dolomite powders is 0.3 mm, as where, the heating temperature was 700 degree celsius, using various holding times (90 and 120 minutes). Under CO 2 dolomite decomposed directly to CaCO 3 accompanied by the formation of MgO, no evidence was offered for the MgO formation of either CaO or MgCO 3 , under air, simultaneous formation of CaCO 3 , CaO and accompanied dolomite decomposition

Thermodynamic modeling of NH_3-CO_2-SO_2-K_2SO_4-H_2O system for combined CO_2 and SO_2 capture using aqueous NH_3

International Nuclear Information System (INIS)

Qi, Guojie; Wang, Shujuan

2017-01-01

Highlights: • A new application of aqueous NH_3 based combined CO_2 and SO_2 process was proposed. • A thermodynamic model simulated the heat of absorption and the K_2SO_4 precipitation. • The CO_2 content can be regenerated in a stripper with lower heat of desorption. • The SO_2 content can be removed by K_2SO_4 precipitation from the lean NH_3 solvent. - Abstract: A new application of aqueous NH_3 based post-combustion CO_2 and SO_2 combined capture process was proposed to simultaneously capture CO_2 and SO_2, and remove sulfite by solid (K_2SO_4) precipitation method. The thermodynamic model of the NH_3-CO_2-SO_2-K_2SO_4-H_2O system for the combined CO_2 and SO_2 capture process was developed and validated in this work to analyze the heat of CO_2 and SO_2 absorption in the NH_3-CO_2-SO_2-H_2O system, and the K_2SO_4 precipitation characteristics in the NH_3-CO_2-SO_2-K_2SO_4-H_2O system. The average heat of CO_2 absorption in the NH_3-CO_2-H_2O system at 40 °C is around −73 kJ/mol CO_2 in 2.5 wt% NH_3 with CO_2 loading between 0.2 and 0.5 C/N. The average heat of SO_2 absorption in the NH_3-SO_2-H_2O system at 40 °C is around −120 kJ/mol SO_2 in 2.5 wt% NH_3 with SO_2 loading between 0 and 0.5 S/N. The average heat of CO_2 absorption in the NH_3-CO_2-SO_2-H_2O system at 40 °C is 77, 68, and 58 kJ/mol CO_2 in 2.5 wt% NH_3 with CO_2 loading between 0.2 and 0.5 C/N, when SO_2 loading is 0, 0.1, 0.2 S/N, respectively. The solubility of K_2SO_4 increases with temperature, CO_2 and SO_2 loadings, but decreases with NH_3 concentration in the CO_2 and SO_2 loaded aqueous NH_3. The thermodynamic evaluation indicates that the combined CO_2 and SO_2 capture process could employ the typical absorption/regeneration process to simultaneously capture CO_2 and SO_2 in an absorber, thermally desorb CO_2 in a stripper, and feasibly remove sulfite (oxidized to sulfate) content by precipitating K_2SO_4 from the lean NH_3 solvent after the lean/rich heat exchanger.

Fuel effect on solution combustion synthesis of Co(Cr,Al)2O4 pigments; Efecto del combustible en la síntesis de pigmentos Co(Cr,Al)2O4 por combustión de una disolución

Energy Technology Data Exchange (ETDEWEB)

Gilabert, J.; Palacios, M.D.; Sanz, V.; Mestre, S.

2017-11-01

The fuel effect on the synthesis of a ceramic pigment with a composition CoCr2−2ΨAl2ΨO4 (0≤Ψ≤1) by means of solution combustion synthesis process (SCS) has been studied. Three different fuels were selected to carry out the synthesis (urea, glycine and hexamethylentetramine (HMT)). Highly foamy pigments with very low density were obtained. Fd-3m spinel-type structure was obtained in all the experiments. Nevertheless, crystallinity and crystallite size of the spinels show significant differences with composition and fuel. The use of glycine along with the chromium-richest composition favours ion rearrangement to obtain the most ordered structure. Lattice parameter does not seem to be affected by fuel, although it evolves with Ψ according to Vegard's law. Colouring power in a transparent glaze shows important variations with composition. On the other hand, fuel effect presents a rather low influence since practically the same shades are obtained. However, it exerts certain effect on luminosity (L*). [Spanish] Se ha estudiado el efecto del combustible en la síntesis de pigmentos cerámicos tipo CoCr2-2ΨAl2ΨO4 (0≤Ψ≤1), obtenidos mediante síntesis por combustión de una disolución. Se seleccionaron 3 tipos de combustible diferentes: urea, glicina y hexametilentetramina. Todos los pigmentos obtenidos presentaron una textura altamente esponjosa y con muy baja densidad. Las estructuras cristalinas desarrolladas en todos los casos fueron tipo espinela Fd-3m. Sin embargo, tanto la cristalinidad como el tamaño de cristalito presentaron diferencias significativas dependiendo de la composición y del combustible utilizado. El uso de glicina, junto con las composiciones más ricas en cromo, favorece la reorganización de los iones para obtener estructuras más ordenadas y con mayor cristalinidad. El parámetro de red no parece verse afectado por el combustible, aunque sí evoluciona con Ψ de acuerdo con la Ley de Vegard. El poder colorante desarrollado

Program Developed for CO2 System Calculations (Program files: CO2SYS_calc_DOS_v1.05; CO2SYS_calc_XLS_v2.3; CO2SYS_calc_MAC_WIN; CO2SYS_calc_MATLAB_v1.1) (NCEI Accession 0164485)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The program CO2SYS performs calculations relating parameters of the carbon dioxide (CO2) system in seawater and freshwater. The program uses two of the four...

Preparation of hydrotalcite compounds using ultrasound irradiation to capture CO{sub 2}; Preparacion de compuestos tipo hidrotalcita utilizando irradiacion de ultrasonido para la captura de CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Martinez, J.A.J.; Paredes, S.P.; Valenzuela, M.A.; Hernandez, M.L. [Instituto Politecnico Nacional, ESIQIE, Mexico, D.F. (Mexico)]. E-mail: sparedesc@ipn.com.mx

2009-09-15

especifica que dependen significativamente del metodo de preparacion, del tiempo de irradiacion y del tipo de componente interlaminar. Con lo anterior se busca sintetizar materiales interlaminares anionicos, muy escasos en la naturaleza, con mejores propiedades que los adsorbentes tradicionales utilizados para la captura de CO{sub 2}.

Interactions between CO2, saline water and minerals during geological storage of CO2

International Nuclear Information System (INIS)

Hellevang, Helge

2006-06-01

The topic of this thesis is to gain a better understanding of interactions between injected CO 2 , aqueous solutions and formation mineralogies. The main focus is concerned with the potential role mineral reactions play in safe long term storage of CO 2 . The work is divided into an experimental part concentrated on the potential of dawsonite (NaAl(OH) 2 CO 3 ) as a permanent storage host of CO 2 , and the development of a new geochemical code ACCRETE that is coupled with the ATHENA multiphase flow simulator. The thesis is composed of two parts: (I) the first part introducing CO 2 storage, geochemical interactions and related work; and (II) the second part that consists of the papers. Part I is composed as follows: Chapter 2 gives a short introduction to geochemical reactions considered important during CO 2 storage, including a thermodynamic framework. Chapter 3 presents objectives of numerical work related to CO 2 -water-rock interactions including a discussion of factors that influence the outcome of numerical simulations. Chapter 4 presents the main results from paper A to E. Chapter 5 give some details about further research that we propose based on the present work and related work in the project. Several new activities have emerged from research on CO 2 -water-rock interaction during the project. Several of the proposed activities are already initiated. Papers A to F are then listed in Part II of the thesis after the citation list. The thesis presents the first data on the reaction kinetics of dawsonite at different pH (Paper A), and comprehensive numerical simulations, both batch- and large scale 3D reactive transport, that illustrate the role different carbonates have for safe storage of CO 2 in geological formations (Papers C to F). The role of dawsonite in CO 2 storage settings is treated throughout the study (Papers A to E) After the main part of the thesis (Part I and II), two appendices are included: Appendix A lists reactions that are included in the

Alcohol synthesis from CO or CO.sub.2

Science.gov (United States)

Hu, Jianli [Kennewick, WA; Dagle, Robert A [Richland, WA; Holladay, Jamelyn D [Kennewick, WA; Cao, Chunshe [Houston, TX; Wang, Yong [Richland, WA; White, James F [Richland, WA; Elliott, Douglas C [Richland, WA; Stevens, Don J [Richland, WA

2010-12-28

Methods for producing alcohols from CO or CO.sub.2 and H.sub.2 utilizing a palladium-zinc on alumina catalyst are described. Methods of synthesizing alcohols over various catalysts in microchannels are also described. Ethanol, higher alcohols, and other C.sub.2+ oxygenates can produced utilizing Rh--Mn or a Fisher-Tropsch catalyst.

Dosis óptima de irradiación gamma con Co60 para inducción de mutagénesis en pastos

Directory of Open Access Journals (Sweden)

Alan Álvarez-Holguín

2017-01-01

Full Text Available La dosis letal (DL 50 y reducción media del crecimiento (RC 50 son parámetros utilizados para seleccionar dosis de irradiación adecuadas e inducir mutaciones para realizar mejoramiento genético vegetal. El objetivo fue determinar la DL 50 y RC 50 para conocer la dosis ó p tima de irradiación c on Co 60 en semilla de pasto llorón, buffel, banderita y navajita. Se evaluaron seis dosis de irradiación con Co 60 en semilla : 100, 200, 300, 450, 600 y 900 Gray (Gy y un tratamiento control (T - 0, sin irradiación. Las variables evaluadas fueron : porcentaj e de germinación (%GE, índice de velocidad de germinación (IVG, longitud de plúmula (LP y longitud de radícula (LR. Se realizó análisis de regresión y comparación de medias con la prueba de Dunnett. Mediante la ecuación de regresión se estimó la DL 50 p ara el %GE, así como RC 50 para el resto de las variables. La DL 50 se ponderó con 55%, mientras que la RC 50 se ponderó en 15% para cada una de las tres variables restantes. En general, los valores de las variables disminuyeron (P<0.05 conforme se incremen tó la dosis de irradiación, lo cual permitió determinar la DL 50 y RC 50 para cada especie. La media ponderada se obtuvo a los 628 Gy, 712 Gy, 698 Gy y 411 Gy para pasto llorón, buffel, banderita y navajita, respectivamente. Se recomiendan las dosis plantead as en este estudio, ya que esto permitirá plantear las bases para realizar mejoramiento genético a través de mutagénesis con irradiación gamma en los pastos evaluados.

Exchange coupling behavior in bimagnetic CoFe{sub 2}O{sub 4}/CoFe{sub 2} nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Leite, G.C.P. [Instituto de Fisica, Universidade Federal de Mato Grosso, 78060-900 Cuiaba-MT (Brazil); Chagas, E.F., E-mail: efchagas@fisica.ufmt.br [Instituto de Fisica, Universidade Federal de Mato Grosso, 78060-900 Cuiaba-MT (Brazil); Pereira, R.; Prado, R.J. [Instituto de Fisica, Universidade Federal de Mato Grosso, 78060-900 Cuiaba-MT (Brazil); Terezo, A.J. [Departamento de Quimica, Universidade Federal do Mato Grosso, 78060-900 Cuiaba-MT (Brazil); Alzamora, M.; Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150 Urca, Rio de Janeiro (Brazil)

2012-09-15

In this work we report a study of the magnetic behavior of ferrimagnetic oxide CoFe{sub 2}O{sub 4} and ferrimagnetic oxide/ferromagnetic metal CoFe{sub 2}O{sub 4}/CoFe{sub 2} nanocomposite. The latter compound is a good system to study hard ferrimagnet/soft ferromagnet exchange coupled. Two steps were followed to synthesize the bimagnetic CoFe{sub 2}O{sub 4}/CoFe{sub 2} nanocomposite: (i) first, preparation of CoFe{sub 2}O{sub 4} nanoparticles using a simple hydrothermal method, and (ii) second, reduction reaction of cobalt ferrite nanoparticles using activated charcoal in inert atmosphere and high temperature. The phase structures, particle sizes, morphology, and magnetic properties of CoFe{sub 2}O{sub 4} nanoparticles were investigated by X-Ray diffraction (XRD), Mossbauer spectroscopy (MS), transmission electron microscopy (TEM), and vibrating sample magnetometer (VSM) with applied field up to 3.0 kOe at room temperature and 50 K. The mean diameter of CoFe{sub 2}O{sub 4} particles is about 16 nm. Mossbauer spectra revealed two sites for Fe{sup 3+}. One site is related to Fe in an octahedral coordination and the other one to the Fe{sup 3+} in a tetrahedral coordination, as expected for a spinel crystal structure of CoFe{sub 2}O{sub 4}. TEM measurements of nanocomposite showed the formation of a thin shell of CoFe{sub 2} on the cobalt ferrite and indicate that the nanoparticles increase to about 100 nm. The magnetization of the nanocomposite showed a hysteresis loop that is characteristic of exchange coupled systems. A maximum energy product (BH){sub max} of 1.22 MGOe was achieved at room temperature for CoFe{sub 2}O{sub 4}/CoFe{sub 2} nanocomposites, which is about 115% higher than the value obtained for CoFe{sub 2}O{sub 4} precursor. The exchange coupling interaction and the enhancement of product (BH){sub max} in nanocomposite CoFe{sub 2}O{sub 4}/CoFe{sub 2} are discussed. - Highlights: Black-Right-Pointing-Pointer CoFe{sub 2}O{sub 4}/CoFe{sub 2} nanocomposite

Modeling CO2 Storage in Fractured Reservoirs: Fracture-Matrix Interactions of Free-Phase and Dissolved CO2

Science.gov (United States)

Oldenburg, C. M.; Zhou, Q.; Birkholzer, J. T.

2017-12-01

The injection of supercritical CO2 (scCO2) in fractured reservoirs has been conducted at several storage sites. However, no site-specific dual-continuum modeling for fractured reservoirs has been reported and modeling studies have generally underestimated the fracture-matrix interactions. We developed a conceptual model for enhanced CO2 storage to take into account global scCO2 migration in the fracture continuum, local storage of scCO2 and dissolved CO2 (dsCO2) in the matrix continuum, and driving forces for scCO2 invasion and dsCO2 diffusion from fractures. High-resolution discrete fracture-matrix models were developed for a column of idealized matrix blocks bounded by vertical and horizontal fractures and for a km-scale fractured reservoir. The column-scale simulation results show that equilibrium storage efficiency strongly depends on matrix entry capillary pressure and matrix-matrix connectivity while the time scale to reach equilibrium is sensitive to fracture spacing and matrix flow properties. The reservoir-scale modeling results shows that the preferential migration of scCO2 through fractures is coupled with bulk storage in the rock matrix that in turn retards the fracture scCO2 plume. We also developed unified-form diffusive flux equations to account for dsCO2 storage in brine-filled matrix blocks and found solubility trapping is significant in fractured reservoirs with low-permeability matrix.

Natural analogue study of CO2 storage monitoring using probability statistics of CO2-rich groundwater chemistry

Science.gov (United States)

Kim, K. K.; Hamm, S. Y.; Kim, S. O.; Yun, S. T.

2016-12-01

For confronting global climate change, carbon capture and storage (CCS) is one of several very useful strategies as using capture of greenhouse gases like CO2 spewed from stacks and then isolation of the gases in underground geologic storage. CO2-rich groundwater could be produced by CO2 dissolution into fresh groundwater around a CO2 storage site. As consequence, natural analogue studies related to geologic storage provide insights into future geologic CO2 storage sites as well as can provide crucial information on the safety and security of geologic sequestration, the long-term impact of CO2 storage on the environment, and field operation and monitoring that could be implemented for geologic sequestration. In this study, we developed CO2 leakage monitoring method using probability density function (PDF) by characterizing naturally occurring CO2-rich groundwater. For the study, we used existing data of CO2-rich groundwaters in different geological regions (Gangwondo, Gyeongsangdo, and Choongchungdo provinces) in South Korea. Using PDF method and QI (quantitative index), we executed qualitative and quantitative comparisons among local areas and chemical constituents. Geochemical properties of groundwater with/without CO2 as the PDF forms proved that pH, EC, TDS, HCO3-, Ca2+, Mg2+, and SiO2 were effective monitoring parameters for carbonated groundwater in the case of CO2leakage from an underground storage site. KEY WORDS: CO2-rich groundwater, CO2 storage site, monitoring parameter, natural analogue, probability density function (PDF), QI_quantitative index Acknowledgement This study was supported by the "Basic Science Research Program through the National Research Foundation of Korea (NRF), which is funded by the Ministry of Education (NRF-2013R1A1A2058186)" and the "R&D Project on Environmental Management of Geologic CO2 Storage" from KEITI (Project number: 2014001810003).

Towards CO2 sequestration and applications of CO2 hydrates: the effects of tetrahydrofuran on the phase equilibria of CO2 hydrates

International Nuclear Information System (INIS)

Khalik, M.S.; Peters, C.J.

2006-01-01

The increasing quantity of carbon dioxide (CO 2 ) in the atmosphere has caused widespread global concerns. Capturing CO 2 from its sources and stored it in the form of gas hydrates and application of CO 2 hydrates are among the proposed methods to overcome this problem. In order to make hydrate-based process more attractive, the use of cyclic ethers as promoters is suggested to reduce the required hydrate formation pressure and enhancing the corresponding kinetic rate. In the present work, tetrahydrofuran (THF) is chosen as a hydrate promoter, participating in forming hydrates and produces mixed hydrate together with CO 2 . The pressure and temperature ranges of hydrate stability region are carefully determined through phase equilibrium measurement of the ternary CO 2 , tetrahydrofuran (THF) and water systems. From the experimental results, it is confirmed that the presence of THF in CO 2 + water systems will extend the hydrate formation region to higher temperature at a constant pressure. The extension of the hydrate stability region is depended on the overall concentration of the ternary system. Moreover, four-phase equilibrium of H-Lw-Lv-V is observed in the system, which may be due to a liquid phase split. In the region where the four-phase equilibrium exists, the ternary system loses its concentration dependency of the hydrate equilibrium conditions. (Author)

INEXPENSIVE CO{sub 2} THICKENING AGENTS FOR IMPROVED MOBILITY CONTROL OF CO{sub 2} FLOODS

Energy Technology Data Exchange (ETDEWEB)

Robert M. Enick; Eric J. Beckman; Andrew Hamilton

2004-10-01

The objective of this research was the design, synthesis and evaluation of inexpensive, nonfluorous carbon dioxide thickening agents. We followed the same strategy employed in the design of fluorinated CO{sub 2} polymeric thickeners. First, a highly CO{sub 2}-philic, hydrocarbon-based monomer was to be identified. Polymers or oligomers of this monomer were then synthesized. The second step was to be completed only when a CO{sub 2}-soluble polymer that was soluble in CO{sub 2} at pressures comparable to the MMP was identified. In the second step, viscosity-enhancing associating groups were to be incorporated into the polymer to make it a viable thickener that exhibited high CO{sub 2} solubility at EOR MMP conditions. This final report documents the CO{sub 2} solubility of a series of commercial and novel polymers composed of carbon, hydrogen, oxygen and, in some cases, nitrogen.

Quantitative analysis of an engineered CO2-fixing Escherichia coli reveals great potential of heterotrophic CO2 fixation.

Science.gov (United States)

Gong, Fuyu; Liu, Guoxia; Zhai, Xiaoyun; Zhou, Jie; Cai, Zhen; Li, Yin

2015-01-01

Production of fuels from the abundant and wasteful CO2 is a promising approach to reduce carbon emission and consumption of fossil fuels. Autotrophic microbes naturally assimilate CO2 using energy from light, hydrogen, and/or sulfur. However, their slow growth rates call for investigation of the possibility of heterotrophic CO2 fixation. Although preliminary research has suggested that CO2 fixation in heterotrophic microbes is feasible after incorporation of a CO2-fixing bypass into the central carbon metabolic pathway, it remains unclear how much and how efficient that CO2 can be fixed by a heterotrophic microbe. A simple metabolic flux index was developed to indicate the relative strength of the CO2-fixation flux. When two sequential enzymes of the cyanobacterial Calvin cycle were incorporated into an E. coli strain, the flux of the CO2-fixing bypass pathway accounts for 13 % of that of the central carbon metabolic pathway. The value was increased to 17 % when the carbonic anhydrase involved in the cyanobacterial carbon concentrating mechanism was introduced, indicating that low intracellular CO2 concentration is one limiting factor for CO2 fixation in E. coli. The engineered CO2-fixing E. coli with carbonic anhydrase was able to fix CO2 at a rate of 19.6 mg CO2 L(-1) h(-1) or the specific rate of 22.5 mg CO2 g DCW(-1) h(-1). This CO2-fixation rate is comparable with the reported rates of 14 autotrophic cyanobacteria and algae (10.5-147.0 mg CO2 L(-1) h(-1) or the specific rates of 3.5-23.7 mg CO2 g DCW(-1) h(-1)). The ability of CO2 fixation was created and improved in E. coli by incorporating partial cyanobacterial Calvin cycle and carbon concentrating mechanism, respectively. Quantitative analysis revealed that the CO2-fixation rate of this strain is comparable with that of the autotrophic cyanobacteria and algae, demonstrating great potential of heterotrophic CO2 fixation.

Dissociative photo-multiple-ionisation of CO and CO2

International Nuclear Information System (INIS)

Bapat, B; Sharma, Vandana; Prajapati, I A; Subramanian, K P; Singh, R K; Lodha, G S

2007-01-01

In a photoelectron-photoion coincidence experiment on CO and CO 2 , we have observed the formation and fragmentation of singly to triply charged CO 2 and singly to quadruply charged CO at various energies. Doubly charged cations of both molecules are found to have unstable as well as stable states. Cations with higher charge are found to dissociate promptly. The energy dependence of the relative partial cross-sections in the energy range 125-310 eV are presented

Study of the hyperfine magnetic field at Ta181 site in the Heusler Co2 Sc Sn, Co2 Sc Ga and Co2 Hf Sn alloys

International Nuclear Information System (INIS)

Attili, R.N.

1992-01-01

The hyperfine magnetic fields acting on 181 Ta nuclei at the Sc and Hf sites have been measured in Heusler alloys Co 2 Sc Sn and Co 2 Sc Ga and Co 2 Hf Sn using the Time Differential Perturbed γ-γ Angular Correlation (TDPAC) technique. The measurements were carried out using an automatic spectrometer consisting of two Ba F 2 detectors and the conventional electronics. The magnitude of hyperfine magnetic field at 181 Ta was measured for all the alloys. The signs of the were determined in the cases of Co 2 Sc Sn and Co 2 Hf Sn alloys by performing the Perturbed Angular Correlation measurements with an external polarizing magnetic field of ≅ 5 k Gauss. The hyperfine magnetic fields obtained are -187,6± 3,3 and 90,0 ± 2,1 kOe measured at 77 K for Co 2 Sc Sn and Co 2 Sc Ga alloys respectively, and -342,4 ± 10,1 kOe measured at the room temperature for Co 2 Hf Sn alloy. These results are discussed and compared with the hyperfine magnetic field systematics in Co-based Heusler alloy. (author)

CO2 Capture and Reuse

International Nuclear Information System (INIS)

Thambimuthu, K.; Gupta, M.; Davison, J.

2003-01-01

CO2 capture and storage including its utilization or reuse presents an opportunity to achieve deep reductions in greenhouse gas emissions from fossil energy use. The development and deployment of this option could significantly assist in meeting a future goal of achieving stabilization of the presently rising atmospheric concentration of greenhouse gases. CO2 capture from process streams is an established concept that has achieved industrial practice. Examples of current applications include the use of primarily, solvent based capture technologies for the recovery of pure CO2 streams for chemical synthesis, for utilization as a food additive, for use as a miscible agent in enhanced oil recovery operations and removal of CO2 as an undesired contaminant from gaseous process streams for the production of fuel gases such as hydrogen and methane. In these applications, the technologies deployed for CO2 capture have focused on gas separation from high purity, high pressure streams and in reducing (or oxygen deficient) environments, where the energy penalties and cost for capture are moderately low. However, application of the same capture technologies for large scale abatement of greenhouse gas emissions from fossil fuel use poses significant challenges in achieving (at comparably low energy penalty and cost) gas separation in large volume, dilute concentration and/or low pressure flue gas streams. This paper will focus on a review of existing commercial methods of CO2 capture and the technology stretch, process integration and energy system pathways needed for their large scale deployment in fossil fueled processes. The assessment of potential capture technologies for the latter purpose will also be based on published literature data that are both 'transparent' and 'systematic' in their evaluation of the overall cost and energy penalties of CO2 capture. In view of the of the fact that many of the existing commercial processes for CO2 capture have seen applications in

Interpreting plant-sampled ¿14CO2 to study regional anthropogenic CO2 signals in Europe

OpenAIRE

Bozhinova, D.N.

2015-01-01

"Interpreting plant-sampled Δ14CO2 to study regional anthropogenic CO2 signals in Europe" Author: Denica Bozhinova This thesis investigates the quantitative interpretation of plant-sampled ∆14CO2 as an indicator of fossil fuel CO2 recently added to the atmosphere. We present a methodology to calculate the ∆14CO2 that has accumulated in a plant over its growing period, based on a modeling framework consisting of a plant growth model (SUCROS) and an atmospheric transport model (WRF-Chem). We ve...

Dynamics of Soil CO2 Profiles of Pinus sylvestris var. sylvestriformis Seedlings Under CO2 Concentration Doubled%CO2倍增条件下长白赤松幼苗土壤CO2廓线的动态

Institute of Scientific and Technical Information of China (English)

韩士杰; 张军辉; 周玉梅; 邹春静

2002-01-01

The gas-well system permanently installed in the soil was adopted for studying the dynamic relationship between CO2 profiles and seedling root growth of Pinus sylvestris var. sylvestriformis (Takenouchi) Cheng et C. D. Chu. The study was conducted in the Open Research Station of Changbai Mountain Forest Ecological System, The Chinese Academy of Sciences from 1999 to 2001. Four treatments were arranged in the rectangular open-top chambers (OTCs): ambient CO2+no-seedling, 700 μmol/mol CO2+no-seedling, ambient CO2 +seedlings, 700 μmol/mol CO2+seedlings. By collecting and analyzing soil gas synchronously, it was found that the dynamics of CO2 profiles were related to the biological activity of seedlings. There were more roots distributed in the top soil and the boundary layer across soil and sand, which made more contributions to the CO2 profiles due to respiration root. Compared with the ambient CO2, elevated CO2 led to the peak of CO2 concentration distribution shifted from soil surface layer to the boundary layer as seasonally growing of seedling roots. It is suggested the gas-well system is an inexpensive, non-destructive and relatively sensitive method for study of soil CO2 concentration profiles.%采用固定在土壤中的气井系统,监测土壤剖面的CO2动态及其与长白赤松 (Pinus sylvestris var. sylvestriformis (Takenouchi) Cheng et C. D. Chu) 幼苗根系发展之间的关系.实验研究共设4种CO2处理,分别是环境CO2浓度,无苗;CO2为700 μmol/mol,无苗;环境CO2浓度,有苗;CO2为700 μmol/mol,有苗.通过对土壤剖面CO2气体的同步采集与分析表明:土壤CO2廓线与幼苗根系的生物活性密切相关.在土壤表面及壤土和沙土的边界层中,根系分布密集,根系的呼吸作用对那两个土层CO2贡献大;随着幼苗的季节生长,与环境CO2浓度比较,CO2倍增将导致土壤剖面上CO2�

Removal of SO42− from Li2CO3 by Recrystallization in Na2CO3 Solution

Directory of Open Access Journals (Sweden)

Wei Cai

2018-01-01

Full Text Available Li2CO3 with high purity is an important raw material for the fabrication of lithium rechargeable batteries. This paper reports a facile recrystallization way to produce Li2CO3 with high purity from commercial Li2CO3 containing 0.8 wt % of SO42− by the treatment of the commercial Li2CO3 in Na2CO3 solution. The increase of temperature from 30 °C to 90 °C favored the recrystallization of Li2CO3 in Na2CO3 solution and promoted the removal of SO42− adsorbed or doped on/in the commercial Li2CO3. The content of SO42− in Li2CO3 decreased to 0.08 wt % after the treatment of the commercial Li2CO3 in 1.0 mol·L−1 Na2CO3 solution at 90 °C for 10.0 h.

Foraminiferal calcification and CO2

Science.gov (United States)

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

2017-12-01

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

Dynamics of soil CO 2 efflux under varying atmospheric CO 2 concentrations reveal dominance of slow processes

Science.gov (United States)

Dohyoung Kim; Ram Oren; James S. Clark; Sari Palmroth; A. Christopher Oishi; Heather R. McCarthy; Chris A. Maier; Kurt Johnsen

2017-01-01

We evaluated the effect on soil CO2 efflux (FCO2) of sudden changes in photosynthetic rates by altering CO2 concentration in plots subjected to +200 ppmv for 15 years. Five-day intervals of exposure to elevated CO2 (eCO2) ranging 1.0–1.8 times ambient did not affect FCO2. FCO2 did not decrease until 4 months after termination of the long-term eCO2 treatment, longer...

Production of C{sup 14}-labelled compounds from C{sup 14}O{sub 2} accelerated in an electric field - Physico-chemical analysis of some radioactive compounds obtained; Production de composes marques au {sup 14}C a partir de {sup 14}CO{sub 2} accelere dans un champ electrique - Analyse physico-chimique de quelques composes radioactifs obtenus; Proizvodstvo mechennykh uglerodom-14 soedinenij iz C{sup 14}O{sub 2}, uskorennogo v ehlektricheskom pole - Fiziko-khimicheskij analiz neskol'kikh poluchennykh radioaktivnykh soedinenij; Obtencion de compuestos marcados con {sup 14}C a partir de {sup 14}CO{sub 2} acelerado en un campo electrico - Analisis fisicoquimico de algunos de los compuestos radiactivos obtenidos

Energy Technology Data Exchange (ETDEWEB)

Guillaume, M [Universite de Liege, Belgique (Belgium)

1962-03-15

This paper describes a method of labelling which is based on the acceleration by an electric field of C{sup 14}O{sub 2}, which can then react with an organic target in its path. The discharge cell described operates at 500 Y, 150 {mu}A, and the organic products to be labelled are exposed to this field for about three hours with CO{sub 2} having a specific activity of 24mc/mmole. The maximum yield remains low (about 6%), and 60% of the C{sup 14}O{sub 2} is destroyed. This maximum activity is obtained only for aliphatic chains (50 {mu}c/g for glutaric acid) or for aromatic substances with an aliphatic chain (acetyl-salicylic acid). (author) [French] Le present memoire expose une methode de marquage basee sur l'acceleration par un champ electrique de {sup 14}CO{sub 2}, qui est alors susceptible d'entrer en reaction avec une cible organique se trouvant dans sa trajectoire. La cellule a decharge decrite fonctionne sous 500 V, 150 {mu}A, et les produits organiques a marquer sont soumis a ce champ pendant environ trois heures, avec du CO{sub 2} d'activite specifique 24 mc/mmole. Le rendement maximum obtenu reste faible (6% environ), et 60% du {sup 14}CO{sub 2} est detruit. Ce rendement maximum n'est obtenu que pour les chaines aliphatiques (50 {mu}c/g pour l'acide glutarique) ou pour des substances aromatiques presentant une chaine aliphatique (acide acetylsalicylique). (author) [Spanish] La memoria describe un metodo de marcacion que consiste en acelerar {sup 14}CO{sub 2} en un campo electrico para que pueda reaccionar con blancos constituidos por sustancias organicas colocadas en su trayectoria. La celda de descarga que describe la memoria funciona a 500 V y 150 {mu}A, y los productos organicos que se desean marcar se exponen al campo asi creado durante unas tres horas a CO{sub 2} de una actividad especifica de 24 mc/mmol. El rendimiento maximo obtenido es bajo (aproximadamente 6%) y el 60% del {sup 14}CO{sub 2} queda destruido. Este rendimiento maximo solo se alcanza

CO_2 valorization - Part. 2: chemical transformation ways

International Nuclear Information System (INIS)

Dumergues, Laurent

2016-01-01

Carbon dioxide (CO_2) can be used in many ways as a raw material or chemical reagent. The chemical conversion of CO_2 used as a feedstock is achievable by different techniques: mineralization, organic synthesis, hydrogenation, dry reforming, electrolysis, thermolysis, etc. The products obtained have applications as energy products, chemicals, building materials, etc. Choosing an appropriate CO_2 reuse technology will depend on technical and economic requirements (such as the CO_2 purity needed, technological maturity, cost-effectiveness, etc.) and also environmental and social criteria

Grado de control metabólico y de factores de riesgo cardiovascular en pacientes con diabetes tipo 2 con y sin enfermedad cardiovascular

Directory of Open Access Journals (Sweden)

Gerardo Garzón

2015-11-01

Conclusiones: En torno a la mitad de los pacientes con diabetes tipo 2 tienen medido cada factor de riesgo cardiovascular. El porcentaje de pacientes con factores controlados es similar a lo publicado y es mayor en los pacientes con enfermedad cardiovascular, pero mejorable. Esto sugiere priorizar las intervenciones en este grupo de pacientes de muy alto riesgo, mejorando la implementación de guías y la adherencia de los pacientes.

CO2 clearance by membrane lungs.

Science.gov (United States)

Sun, Liqun; Kaesler, Andreas; Fernando, Piyumindri; Thompson, Alex J; Toomasian, John M; Bartlett, Robert H

2018-05-01

Commercial membrane lungs are designed to transfer a specific amount of oxygen per unit of venous blood flow. Membrane lungs are much more efficient at removing CO 2 than adding oxygen, but the range of CO 2 transfer is rarely reported. Commercial membrane lungs were studied with the goal of evaluating CO 2 removal capacity. CO 2 removal was measured in 4 commercial membrane lungs under standardized conditions. CO 2 clearance can be greater than 4 times that of oxygen at a given blood flow when the gas to blood flow ratio is elevated to 4:1 or 8:1. The CO 2 clearance was less dependent on surface area and configuration than oxygen transfer. Any ECMO system can be used for selective CO 2 removal.

Determining CO2 storage potential during miscible CO2 enhanced oil recovery: Noble gas and stable isotope tracers

Science.gov (United States)

Shelton, Jenna L.; McIntosh, Jennifer C.; Hunt, Andrew; Beebe, Thomas L; Parker, Andrew D; Warwick, Peter D.; Drake, Ronald; McCray, John E.

2016-01-01

Rising atmospheric carbon dioxide (CO2) concentrations are fueling anthropogenic climate change. Geologic sequestration of anthropogenic CO2 in depleted oil reservoirs is one option for reducing CO2 emissions to the atmosphere while enhancing oil recovery. In order to evaluate the feasibility of using enhanced oil recovery (EOR) sites in the United States for permanent CO2 storage, an active multi-stage miscible CO2flooding project in the Permian Basin (North Ward Estes Field, near Wickett, Texas) was investigated. In addition, two major natural CO2 reservoirs in the southeastern Paradox Basin (McElmo Dome and Doe Canyon) were also investigated as they provide CO2 for EOR operations in the Permian Basin. Produced gas and water were collected from three different CO2 flooding phases (with different start dates) within the North Ward Estes Field to evaluate possible CO2 storage mechanisms and amounts of total CO2retention. McElmo Dome and Doe Canyon were sampled for produced gas to determine the noble gas and stable isotope signature of the original injected EOR gas and to confirm the source of this naturally-occurring CO2. As expected, the natural CO2produced from McElmo Dome and Doe Canyon is a mix of mantle and crustal sources. When comparing CO2 injection and production rates for the CO2 floods in the North Ward Estes Field, it appears that CO2 retention in the reservoir decreased over the course of the three injections, retaining 39%, 49% and 61% of the injected CO2 for the 2008, 2010, and 2013 projects, respectively, characteristic of maturing CO2 miscible flood projects. Noble gas isotopic composition of the injected and produced gas for the flood projects suggest no active fractionation, while δ13CCO2 values suggest no active CO2dissolution into formation water, or mineralization. CO2 volumes capable of dissolving in residual formation fluids were also estimated along with the potential to store pure-phase supercritical CO2. Using a combination

CO2 removals and CO2 and non-CO2 trace gas emissions affected by human activity in the forests in the Republic of macedonia

International Nuclear Information System (INIS)

Grupche, Ljupcho; Lozanovski, Risto; Markovska, Natasha

2001-01-01

During 2000 and 2001 inventories of CO 2 removals and emissions caused by changes in forest and other woody biomass stocks, as well as the inventories of CO 2 and non-CO 2 trace gas emissions caused by forest conversions (accidental burning) were carried out. According to the forest area in ha, and depending on the differences between the annual biomass increment and annual biomass consumption, about 30-50% of total annual carbon uptake increment is released through the biomass consumption from stocks. 50-70% of the net annual carbon uptake converted to CO 2 identify the annual removals of this gas, which is on average 1805 Gg/yr, ranging between 1485 and 2243 Gg/yr. From 1990 to 1998 on average 4700 ha forest area (min. 110 ha in 1991, max. 14420 ha in 1993) was burned. Proportionally to the burned area, there was a release on average of 18.62 kt C annually (min. 0.42 kt C, max. 57.11 kt), related to 136.07 kt CO 2 on average (min. 1.5 kt CO 2 , max. 209.22 kt CO 2 ). (Original)

Thermodynamics of CoAl2O4-CoGa2O4 solid solutions

International Nuclear Information System (INIS)

Lilova, Kristina I.; Navrotsky, Alexandra; Melot, Brent C.; Seshadri, Ram

2010-01-01

CoAl 2 O 4 , CoGa 2 O 4 , and their solid solution Co(Ga z Al 1-z ) 2 O 4 have been studied using high temperature oxide melt solution calorimetry in molten 2PbO.B 2 O 3 at 973 K. There is an approximately linear correlation between lattice parameters, enthalpy of formation from oxides, and the Ga content. The experimental enthalpy of mixing is zero within experimental error. The cation distribution parameters are calculated using the O'Neill and Navrotsky thermodynamic model. The enthalpies of mixing calculated from these parameters are small and consistent with the calorimetric data. The entropies of mixing are calculated from site occupancies and compared to those for a random mixture of Ga and Al ions on octahedral site with all Co tetrahedral and for a completely random mixture of all cations on both sites. Despite a zero heat of mixing, the solid solution is not ideal in that activities do not obey Raoult's Law because of the more complex entropy of mixing. - Graphical abstract: Measured enthalpies of mixing of CoAl 2 O 4 -CoGa 2 O 4 solid solutions are close to zero but entropies of mixing reflect the complex cation distribution, so the system is not an ideal solution.

Sustained effects of atmospheric [CO2] and nitrogen availability on forest soil CO2 efflux.

Science.gov (United States)

Oishi, A Christopher; Palmroth, Sari; Johnsen, Kurt H; McCarthy, Heather R; Oren, Ram

2014-04-01

Soil CO2 efflux (Fsoil ) is the largest source of carbon from forests and reflects primary productivity as well as how carbon is allocated within forest ecosystems. Through early stages of stand development, both elevated [CO2] and availability of soil nitrogen (N; sum of mineralization, deposition, and fixation) have been shown to increase gross primary productivity, but the long-term effects of these factors on Fsoil are less clear. Expanding on previous studies at the Duke Free-Air CO2 Enrichment (FACE) site, we quantified the effects of elevated [CO2] and N fertilization on Fsoil using daily measurements from automated chambers over 10 years. Consistent with previous results, compared to ambient unfertilized plots, annual Fsoil increased under elevated [CO2] (ca. 17%) and decreased with N (ca. 21%). N fertilization under elevated [CO2] reduced Fsoil to values similar to untreated plots. Over the study period, base respiration rates increased with leaf productivity, but declined after productivity saturated. Despite treatment-induced differences in aboveground biomass, soil temperature and water content were similar among treatments. Interannually, low soil water content decreased annual Fsoil from potential values - estimated based on temperature alone assuming nonlimiting soil water content - by ca. 0.7% per 1.0% reduction in relative extractable water. This effect was only slightly ameliorated by elevated [CO2]. Variability in soil N availability among plots accounted for the spatial variability in Fsoil , showing a decrease of ca. 114 g C m(-2) yr(-1) per 1 g m(-2) increase in soil N availability, with consistently higher Fsoil in elevated [CO2] plots ca. 127 g C per 100 ppm [CO2] over the +200 ppm enrichment. Altogether, reflecting increased belowground carbon partitioning in response to greater plant nutritional needs, the effects of elevated [CO2] and N fertilization on Fsoil in this stand are sustained beyond the early stages of stand development and

CO2 capture. Two new structures in the 2-amino-2-methyl-1-propanol (AMP) – water – CO2 system

DEFF Research Database (Denmark)

Ståhl, Kenny; Neerup, Randi; Fosbøl, Philip Loldrup

2016-01-01

Energy production and transportation is responsible for more than 60 % of our CO2 emission. In particular coal-fired power plants are big contributors. However, these large scale facilities offer the possibility to effective CO2 capture through post-combustion processes. There are several options...... studied the 2-amino-2-methyl-1-propanol (AMP) and the AMP-water phase diagramand its ability for CO2 capture. The first crystal structure in the AMP – water system has been solved from powder diffraction data: AMP trihydrate (triclinic, P-1, a = 6.5897(3), b = 6.399 (2), c = 6.3399(2) Å and α = 92.40 (3...... for such CO2 capture. The problem is to make the absorption/desorption processes energetically and thereby economically viable. One process under investigation involves alkanoamines as absorbents in aqueous solutions. In these systems CO2 is captured either by carbonate and/orcarbamate formation. We have...

Evaluación no destructiva de la patogenicidad de Cercospora agavicola en vitroplántulas de agave azul tequilero irradiadas con rayos gamma Co60

OpenAIRE

Ángeles-Espino, A.; Virgen-Calleros, G.; Valencia-Botín, J.; Ramírez-Serrano, C.; Paredes-Gutiérrez, L.; Hurtado-De la Peña, S.

2016-01-01

Resumen: El cultivo del agave y el tequila tienen importancia económica y social por los empleos en campo y la industria, además por las divisas de la exportación. El tizón foliar causado por Cercospora agavicola representa un alto riesgo en la zona de Los Altos de Jalisco, debido a que el clima favorece la dispersión y germinación de las esporas. Se inocularon plántulas obtenidas a partir de yemas axilares, mismas que se irradiaron con rayos gamma Co60 a 0 Gy (testigo), 5 Gy, 10 Gy, 15 Gy, 2...

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

The formation mechanism of a textured ceramic of thermoelectric [Ca2CoO3](0.62)[CoO2] on beta-Co(OH)2 templates through in situ topotactic conversion.

Science.gov (United States)

Itahara, Hiroshi; Seo, Won-Seon; Lee, Sujeong; Nozaki, Hiroshi; Tani, Toshihiko; Koumoto, Kunihito

2005-05-04

We investigated the formation mechanism of thermoelectric [Ca(2)CoO(3)](0.62)[CoO(2)] (CCO) on beta-Co(OH)(2) templates with maintained orientations by identifying the intermediate phases and specifying the relationship between their crystallographic orientations. We mixed beta-Co(OH)(2) templates with the complementary reactant CaCO(3) and prepared a compact by tape casting, with the developed (001) plane of the templates aligned along the casting plane. High-temperature XRD of the compact revealed that beta-Co(OH)(2) decomposed into Co(3)O(4) by 873 K, and Co(3)O(4) reacted with CaO to form CCO by 1193 K via the formation of the newly detected intermediate phase beta-Na(x)()CoO(2)-type Ca(x)()CoO(2) at 913-973 K. Pole figure measurements and SEM and TEM observations revealed that the relationship between the crystallographic planes was (001) beta-Co(OH)(2)//{111} Co(3)O(4)//(001) Ca(x)()CoO(2)//(001) CCO. The crystal structures of the four materials possess the common CoO(2) layer (or similar), which is composed of edge-sharing CoO(6) octahedra, parallel to the planes. The cross-sectional HRTEM analysis of an incompletely reacted specimen showed transient lattice images from Ca(x)()CoO(2) into CCO, in which every other CoO(2) layer of Ca(x)()CoO(2) was preserved. Thus, it was demonstrated that a textured CCO ceramic is produced through a series of in situ topotactic conversion reactions with a preserved CoO(2) layer of its template.

OXIDACIÓN CATALÍTICA DE TOLUENO Y 2-PROPANOL SOBRE ÓXIDOS MIXTOS DE Mn yCo OBTENIDOS POR COPRECIPITACIÓN

Directory of Open Access Journals (Sweden)

Maria Castaño

2014-07-01

Full Text Available Óxidos mixtos de manganeso y cobalto con relaciones molares M2++ Mg2+/M3+=3 y M2+/Mg2+ =1 fueron preparados por el método de coprecipitación. Los sólidos fueron caracterizados por las técnicas de difracción de rayos X  (XRD, temperatura programada de reducción (TPR-H2, área superficial y empleados en la oxidación catalítica de  una mezcla de dos compuestos orgánicos representativos de COVs: el tolueno y el 2-propanol.El óxido mixto de manganeso logró una oxidación del 100% de la mezcla de COVs mientras que el óxido mixto de cobalto no alcanza una oxidación total.El catalizador Mn-Mg-Al presentó las menores temperaturas de oxidación de tolueno y  2-propanol en la mezcla, haciéndolo el catalizador más eficiente. El  desempeño catalítico superior de dicho óxido está asociado principalmente a su mejor comportamiento redox comparado con el óxido el del cobalto.Con el fin de evaluar el efecto de la composición del reactivo, se estudió la oxidación catalítica individual de tolueno y 2-propanol sobre el óxido mixto de manganeso. El catalizadorfue activoen la oxidación de los dos COVsindividuales siendo el tolueno el compuesto más difícil de oxidar. Este catalizador mostró 100% de conversión hacia CO2 para el tolueno mientras que con el 2-propanol produce primero acetona la cual  posteriormente oxidada hasta CO2. Las temperaturas de oxidación de los componentes en la mezcla de COVsfueron superiores que en la conversión individual de tolueno y 2-propanol. Este resultado sugiere un posible efecto inhibitorio en la oxidación de 2-propanol cuando se tienen mezclas de los COVs.

CO2 production in anthropogenic Chinampas soils in Mexico City La producción de CO2 en suelos antropogénicos de Chinampas en la Ciudad de México A produção de CO2 em solos antropogénicos de Chinampas na cidade do México

Directory of Open Access Journals (Sweden)

Elena Ikkonen

2012-07-01

> production to temperature is highest under drought stress.

En este trabajo estudiamos la producción de CO₂ asociada a la actividad de los microorganismos en suelos antropogénicos de chinampa, construidos por las culturas Pre-Hispánicas en México mediante la acumulación de materia orgánica, sedimentos lacustres limosos o por diferentes materiales utilizados para consolidarlos en islotes separados por un sistema de canales. Se tomaron muestras de suelo a las profundidades de 0-7, 7-18, 18-30, 30-40 y 40-50 cm para evaluar la sensibilidad a la temperatura de la producción de CO₂ y su variación en relación con la profundidad del suelo, la humedad y la disponibilidad de oxígeno. Se incubaron en condiciones aerobias y anaerobias a temperatura controlada (-5, 0, 5, 10, 20 y 30 °C y a humedad controlada de 10, 30, 60 y 90% de las condiciones de saturación en agua del espacio poroso del suelo. Para todas las profundidades del suelo, temperaturas de incubación y humedad del suelo, la velocidad promedio de producción de CO₂ fue de 58,0 mg CO₂ kg^-1 d^-1 en condiciones aerobias y de 31,2 mg CO₂ kg^-1 d^-1en condiciones anaerobias, obteniéndose la mayor producción de CO₂ en las muestras de suelo de la capa de 0-7 cm de profundidad. La disminución en el contenido de carbono orgánico del suelo inhibió la producción de CO₂ asociada a la actividad de los microorganismos del suelo con mayor intensidad bajo condiciones anaerobias que aerobias. A temperaturas inusualmente bajas o altas para el área de estudio, la dependencia de la producción aerobia de CO₂ con respecto a la humedad del suelo aumentó. Puesto que la respuesta de la producción de CO₂ a la temperatura fue menor bajo condiciones anaerobias que aerobias, el aumento en el contenido de humedad del suelo condujo a la disminución de

Topotactic reduction of YBaCo2O5 and LaBaCo2O5: square-planar Co(I) in an extended oxide.

Science.gov (United States)

Seddon, James; Suard, Emmanuelle; Hayward, Michael A

2010-03-03

The low-temperature reduction of YBaCo(2)O(5) and LaBaCo(2)O(5) with NaH to form YBaCo(2)O(4.5) and YBaCo(2)O(4.25), respectively, demonstrates that the structures of anion-deficient materials formed by such topotactic reductions can be directed by the ordering and identity of the A-site cations. YBaCo(2)O(4.5) adopts a structure consisting of a corner-shared network of square-based pyramidal CoO(5) and distorted tetrahedral CoO(4) units. The structure of LaBaCoO(4.25) is more complex, consisting of an array of square-based pyramidal CoO(5), distorted tetrahedral CoO(4), and square planar CoO(4) units. Magnetic susceptibility and variable-temperature neutron diffraction data reveal that YBaCo(2)O(4.5) adopts a G-type antiferromagnetically ordered structure below T(N) approximately 280 K. LaBaCo(2)O(4.25) also adopts antiferromagnetic order (T(N) approximately 325 K) with ordered moments consistent with the presence of square-planar, low-spin, s = 0, Co(I) centers. A detailed analysis reveals that the different anion vacancy ordered structures adopted by the two REBaCo(2)O(5-x) phases are directed by the relative sizes and ordering of the La(3+) and Y(3+) cations. This suggests that ordered arrangements of A-cations can be used to direct the anion vacancy order in topotactically reduced phases, allowing the preparation of novel metal-oxygen networks containing unusual transition metal coordination environments.

Celulitis orbitaria bilateral con endoftalmitis en una paciente con reciente diagnóstico de diabetes mellitus tipo 2

OpenAIRE

Farrell González, Lesley; Ezpeleta Rodríguez, Mayra M.; Sierra Garcia, Carlos; Mayer Rivera, Francisco

2014-01-01

Se presentó una mujer de 74 años al servicio de urgencias del HRAEBI, ISSSTE, el día 2 de septiembre de 2010 con datos de desequilibrio hidroelectrolítico, hipotensión y conjuntivitis bilateral. Sus signos vitales durante su estancia en urgencias fueron: tensión arterial, 80/40 mmHg; temperatura, 38.5 °C; frecuencia respiratoria, 22 rpm; frecuencia cardíaca 89 lpm Se interconsulta al servicio de Oftalmología quienes diagnosticaron celulitis orbitaria bilateral, con no percepción de luz en amb...

History of CO/sub 2/

Energy Technology Data Exchange (ETDEWEB)

Degens, E T

1979-01-01

Upon arrival on earth, the reduced carbon pool split into a series of compartments: core, mantle, crust, hydrosphere, atmosphere, and biosphere. This distribution pattern is caused by the ability of carbon to adjust structurally to a wide range of pressure and temperature, and to form simple and complex molecules with oxygen, hydrogen and nitrogen. Transformation also involved oxidation of carbon to CO/sub 2/ which is mediated at depth by minerals, such as magnetite, and by water vapor above critical temperature. Guided by mineral-organic interactions, simple carbon compounds evolved in near surface environments towards physiologically interesting biochemicals. Life, as an autocatalytic system, is considered an outgrowth of such a development. This article discusses environmental parameters that control the CO/sub 2/ system, past and present. Mantle and crustal evolution is the dynamo recharging the CO/sub 2/ in sea and air; the present rate of CO/sub 2/ release from the magma is 0.05 x 10/sup 15/ g C per year. Due to the enormous buffer capacity of the chemical system ocean, such rates are too small to seriously effect the level of CO/sub 2/ in our atmosphere. In the light of geological field data and stable isotope work, it is concluded that the CO/sub 2/ content in the atmosphere has remained fairly uniform since early Precambrian time; CO/sub 2/ should thus have had little impact on paleoclimate. In contrast, the massive discharge of man-made CO/sub 2/ into our atmosphere may have serious consequences for climate, environment and society in the years to come.

Method to reduce CO.sub.2 to CO using plasmon-enhanced photocatalysis

Science.gov (United States)

Huber, George W.; Upadhye, Aniruddha A.; Kim, Hyung Ju; Ro, Insoo; Tejedor-Anderson, M. Isabel

2017-08-22

Described is a method of reducing CO.sub.2 to CO using visible radiation and plasmonic photocatalysts. The method includes contacting CO.sub.2 with a catalyst, in the presence of H.sub.2, wherein the catalyst has plasmonic photocatalytic reductive activity when exposed to radiation having a wavelength between 380 nm and 780 nm. The catalyst, CO.sub.2, and H.sub.2 are exposed to non-coherent radiation having a wavelength between 380 nm and 780 nm such that the catalyst undergoes surface plasmon resonance. The surface plasmon resonance increases the rate of CO.sub.2 reduction to CO as compared to the rate of CO.sub.2 reduction to CO without surface plasmon resonance in the catalyst.

Electrocatalytic Alloys for CO2 Reduction.

Science.gov (United States)

He, Jingfu; Johnson, Noah J J; Huang, Aoxue; Berlinguette, Curtis P

2018-01-10

Electrochemically reducing CO 2 using renewable energy is a contemporary global challenge that will only be met with electrocatalysts capable of efficiently converting CO 2 into fuels and chemicals with high selectivity. Although many different metals and morphologies have been tested for CO 2 electrocatalysis over the last several decades, relatively limited attention has been committed to the study of alloys for this application. Alloying is a promising method to tailor the geometric and electric environments of active sites. The parameter space for discovering new alloys for CO 2 electrocatalysis is particularly large because of the myriad products that can be formed during CO 2 reduction. In this Minireview, mixed-metal electrocatalyst compositions that have been evaluated for CO 2 reduction are summarized. A distillation of the structure-property relationships gleaned from this survey are intended to help in the construction of guidelines for discovering new classes of alloys for the CO 2 reduction reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bis(2,2′-bipyridyl-κ2N,N′(sulfato-κ2O,O′cobalt(II ethane-1,2-diol monosolvate

Directory of Open Access Journals (Sweden)

Lin Chen

2011-01-01

Full Text Available The title compound, [Co(SO4(C10H8N22]·C2H6O2, has the Co2+ ion in a distorted octahedral CoN4O2 coordination geometry. A twofold rotation axis passes through the Co and S atoms, and through the mid-point of the C—C bond of the ethanediol molecule. In the crystal, the [CoSO4(C10H8N22] and C2H6O2 units are held together by a pair of O—H...O hydrogen bonds.

Thermodynamic stability and guest distribution of CH4/N2/CO2 mixed hydrates for methane hydrate production using N2/CO2 injection

International Nuclear Information System (INIS)

Lim, Dongwook; Ro, Hyeyoon; Seo, Yongwon; Seo, Young-ju; Lee, Joo Yong; Kim, Se-Joon; Lee, Jaehyoung; Lee, Huen

2017-01-01

Highlights: • We examine the thermodynamic stability and guest distribution of CH 4 /N 2 /CO 2 mixed hydrates. • Phase equilibria of the CH 4 /N 2 /CO 2 mixed hydrates were measured to determine the thermodynamic stability. • The N 2 /CO 2 ratio of the hydrate phase is almost constant despite the enrichment of CO 2 in the hydrate phase. • 13 C NMR results indicate the preferential occupation of N 2 and CO 2 in the small and large cages of sI hydrates, respectively. - Abstract: In this study, thermodynamic stability and cage occupation behavior in the CH 4 – CO 2 replacement, which occurs in natural gas hydrate reservoirs by injecting flue gas, were investigated with a primary focus on phase equilibria and composition analysis. The phase equilibria of CH 4 /N 2 /CO 2 mixed hydrates with various compositions were measured to determine the thermodynamic stability of gas hydrate deposits replaced by N 2 /CO 2 gas mixtures. The fractional experimental pressure differences (Δp/p) with respect to the CSMGem predictions were found to range from −0.11 to −0.02. The composition analysis for various feed gas mixtures with a fixed N 2 /CO 2 ratio (4.0) shows that CO 2 is enriched in the hydrate phase, and the N 2 /CO 2 ratio in the hydrate phase is independent of the feed CH 4 fractions. Moreover, 13 C NMR measurements indicate that N 2 molecules preferentially occupy the small 5 12 cages of sI hydrates while the CO 2 molecules preferentially occupy the large 5 12 6 2 cages, resulting in an almost constant area ratio of CH 4 molecules in the large to small cages of the CH 4 /N 2 /CO 2 mixed hydrates. The overall experimental results provide a better understanding of stability conditions and guest distributions in natural gas hydrate deposits during CH 4 – flue gas replacement.

Riesgo coronario en pacientes con diabetes mellitus tipo 2

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Andrés Eduardo Gallegos Cobo

2017-09-01

CONCLUSION: La estratificación del riesgo coronario elevado en pacientes con DM2 fueron frecuentes en este estudio comportándose de forma similar a otras casuísticas revisadas sobre este tema, repercutiendo de forma integral en la salud cardiovascular, ultimando hasta el momento no se ha implementado recomendaciones según estrategias en el servicio de Medicina Interna. Recomendando se realice estudios cuyo propósito es generar estrategias integrales para concientizar a los pacientes y al personal de salud sobre la necesidad de prevenir y controlar el riesgo coronario, y con ello disminuir los ingresos hospitalarios, costos económicos, las comorbilidades e incrementar la expectativa y calidad de vida de quienes la padecen.

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.

Efecto magnetocalórico en aleaciones ferromagnéticas con memoria de forma monocristalinas de NiFeCoGa.

OpenAIRE

Vázquez Risco, Alain

2017-01-01

Este trabajo se centrará en el estudio del efecto magnetocalórico de una aleación monocristalina ferromagnética de composición Ni-Fe-Co-Ga. Este tipo de material entra dentro de las denominadas aleaciones con memoria de forma o SMA (Shape Memory Alloys). Estas aleaciones presentan los efectos de memoria de forma de las propias SMA y otras características como las uperelasticidad, los efectos magnetocalóricos directo e inverso. El interés de estos materiales se debe a que pued...

A joint global carbon inversion system using both CO2 and 13CO2 atmospheric concentration data

Science.gov (United States)

Chen, Jing M.; Mo, Gang; Deng, Feng

2017-03-01

Observations of 13CO2 at 73 sites compiled in the GLOBALVIEW database are used for an additional constraint in a global atmospheric inversion of the surface CO2 flux using CO2 observations at 210 sites (62 collocated with 13CO2 sites) for the 2002-2004 period for 39 land regions and 11 ocean regions. This constraint is implemented using prior CO2 fluxes estimated with a terrestrial ecosystem model and an ocean model. These models simulate 13CO2 discrimination rates of terrestrial photosynthesis and ocean-atmosphere diffusion processes. In both models, the 13CO2 disequilibrium between fluxes to and from the atmosphere is considered due to the historical change in atmospheric 13CO2 concentration. This joint inversion system using both13CO2 and CO2 observations is effectively a double deconvolution system with consideration of the spatial variations of isotopic discrimination and disequilibrium. Compared to the CO2-only inversion, this 13CO2 constraint on the inversion considerably reduces the total land carbon sink from 3.40 ± 0.84 to 2.53 ± 0.93 Pg C year-1 but increases the total oceanic carbon sink from 1.48 ± 0.40 to 2.36 ± 0.49 Pg C year-1. This constraint also changes the spatial distribution of the carbon sink. The largest sink increase occurs in the Amazon, while the largest source increases are in southern Africa, and Asia, where CO2 data are sparse. Through a case study, in which the spatial distribution of the annual 13CO2 discrimination rate over land is ignored by treating it as a constant at the global average of -14. 1 ‰, the spatial distribution of the inverted CO2 flux over land was found to be significantly modified (up to 15 % for some regions). The uncertainties in our disequilibrium flux estimation are 8.0 and 12.7 Pg C year-1 ‰ for land and ocean, respectively. These uncertainties induced the unpredictability of 0.47 and 0.54 Pg C year-1 in the inverted CO2 fluxes for land and ocean, respectively. Our joint inversion system is therefore

CO2-neutral fuels

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Goede A. P. H.

2015-01-01

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

The Texts of the Agency's Co-operation Agreements with Regional Intergovernmental Organizations; Texto de los Acuerdos de Colaboracion del Organismo con las Organizaciones Intergubernamentales Regionales

Energy Technology Data Exchange (ETDEWEB)

NONE

1961-02-07

The texts of the Agency's agreements for co-operation with the regional inter-governmental organizations listed below, together with the respective protocols authenticating them, are reproduced in this document in the order in which the agreements entered into force, for the information of all Members of the Agency [Spanish] Para conocimiento de todos los Estados Miembros del Organismo, en este documento se transcriben en el orden en que entraron en vigor, los acuerdos de colaboracion que el Organismo ha concertado con las organizaciones intergubernamentales regionales que a continuacion se enumeran, junto con los respectivos protocolos de autenticacion.

Industrial Analogues on CO{sub 2} Storage; Analogos Industriales del Almacenamiento de CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Martinez, R; Campos, R; Perez del Villar, L; Suarez, I; Zapatero, M A

2008-08-06

This volume tries to introduce the study of industrial analogues of CO{sub 2} storage, those industrial activities that, because of some specific conditions, are considered similar to CO{sub 2} geological storage activities. The goal is to obtain useful conclusions for application in the incipient exploration of this type of storages. Therefore, strategic storages of natural gas have been studied, with a special emphasis in the project developed in the surroundings of Yela (Guadalajara). Other activities are also described, as some projects that include CO{sub 2} injection to increase the recovery of oil and/or gas in nearly depleted reservoirs, and also a case of CO{sub 2} storage in a saline aquifer (Salipriina). Finally, Rewopol Project methodology is summarized, as an experimental case of CO{sub 2} storage on coal, coupled with coal bed methane production. Summing up, the main goal of this work is to determine the most adequate technologies that have to be developed in a successful CO{sub 2} storage, exploration and exploitation project. (Author) 28 refs.

CO2 storage in deep underground strata. Integrity of deep wells under the influence of CO2; CO{sub 2} Lagerung im Geogrund. Integritaet von Tiefbohrungen unter Einfluss von CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Reinicke, K.M.; Franz, O. [Technische Univ. Clausthal (Germany). Inst. fuer Erdoel- und Erdgastechnik; Nangue Donfack, R. [Baker Hughes GmbH, Houston, TX (United States); Shinde, S. [Shell (Germany)

2007-09-13

Deep underground storage of CO2 is possible in petroleum reservoirs, gas reservoirs, aquifers and coal seams. Two aspects must be considered for safety: First, the technical integrity of the production and injection systems must be ensured during the operating phase of, typically, 10 to 50 years. Secondly, the technical integrity of the boreholes must be ensured for the whole storage period of 100 to 5000 years in order to prevent release of CO2 through the boreholes after sealing. The industry has long years of experience with injection of CO2 gained in CO2 enhanced oil recovery (EOR), in the production of high-pressure acid gas from natural gas wells, and in the injection of the acid components H2S and CO2 separated during acid gas production. Completion equipment and components of CO2 EOR and acid gas projects were analyzed, and detailed information on potential failure processes and their consequences. There are no major problems in ensuring safe injection and production during the operating phase. In contrast, the proof of technical stability over a period of 1000 years and more is a challenge as the experience so far covers only a few decades. This is the focus of research projects worldwide. The contribution presents the state of the art and shows how safe storage of CO2 may be possible. The results presented are part of the activities carried out in the CSEGR project (Carbon Sequestration with Enhanced Gas REcovery). The partners of Clausthal University are: Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hanover, EEG - Erdgas Erdoel GmbH Berlin, Wintershall AG Kassel, Vattenfall AB, and E.ON Ruhrgas GmbH, Essen. The project receives BMBF funds from the GEOTECHNOLOGIEN programme. (orig.)

Analysis of a New Liquefaction Combined with Desublimation System for CO2 Separation Based on N2/CO2 Phase Equilibrium

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Wenchao Yang

2015-09-01

Full Text Available Cryogenic CO2 capture is considered as a promising CO2 capture method due to its energy saving and environmental friendliness. The phase equilibrium analysis of CO2-mixtures at low temperature is crucial for the design and operation of a cryogenic system because it plays an important role in analysis of recovery and purity of the captured CO2. After removal of water and toxic gas, the main components in typical boiler gases are N2/CO2. Therefore, this paper evaluates the reliabilities of different cubic equations of state (EOS and mixing rules for N2/CO2. The results show that Peng-Robinson (PR and Soave-Redlich-Kwong (SRK fit the experimental data well, PR combined with the van der Waals (vdW mixing rule is more accurate than the other models. With temperature decrease, the accuracy of the model improves and the deviation of the N2 vapor fraction is 0.43% at 220 K. Based on the selected calculation model, the thermodynamic properties of N2/CO2 at low temperature are analyzed. According to the results, a new liquefaction combined with a desublimation system is proposed. The total recovery and purity of CO2 production of the new system are satisfactory enough for engineering applications. Additionally, the total energy required by the new system to capture the CO2 is about 3.108 MJ·kg−1 CO2, which appears to be at least 9% lower than desublimation separation when the initial concentration of CO2 is 40%.

Celulitis orbitaria bilateral con endoftalmitis en una paciente con reciente diagnóstico de diabetes mellitus tipo 2

Directory of Open Access Journals (Sweden)

Lesley Farrell González

2014-07-01

Full Text Available Se presentó una mujer de 74 años al servicio de urgencias del HRAEBI, ISSSTE, el día 2 de septiembre de 2010 con datos de desequilibrio hidroelectrolítico, hipotensión y conjuntivitis bilateral. Sus signos vitales durante su estancia en urgencias fueron: tensión arterial, 80/40 mmHg; temperatura, 38.5 °C; frecuencia respiratoria, 22 rpm; frecuencia cardíaca 89 lpm Se interconsulta al servicio de Oftalmología quienes diagnosticaron celulitis orbitaria bilateral, con no percepción de luz en ambos ojos e igualmente ausencia de reflejos pupilares. Se inició tratamiento con antibióticos intravenosos y se solicitó tomografía computarizada de órbitas y cerebro. Se internó para estabilizar su estado general; durante su estancia se diagnosticó diabetes mellitus y estado inmunosupresivo por datos de candidiasis oral y otros síntomas. La tomografía mostró celulitis orbitaria bilateral con formación de abscesos orbitarios, sin datos de proceso infeccioso a nivel bucal o de senos paranasales. La evolución de la celulitis fue tórpida a pesar de la terapia antibiótica cuádruple (cefotaxima, vancomicina, metronidazol y clindamicina; posteriormente imipenem, clindamicina y vancomicina con desarrollo de endoftalmitis bilateral por lo cual fue necesario eviscerar ambos ojos. Se tomó cultivo directo del vítreo y 3 días después se encontró como germen causal Klebsiella pneumoniae.

trans-(Cl)-[Ru(5,5'-diamide-2,2'-bipyridine)(CO)2 Cl2 ]: Synthesis, Structure, and Photocatalytic CO2 Reduction Activity.

Science.gov (United States)

Kuramochi, Yusuke; Fukaya, Kyohei; Yoshida, Makoto; Ishida, Hitoshi

2015-07-06

A series of trans-(Cl)-[Ru(L)(CO)2 Cl2 ]-type complexes, in which the ligands L are 2,2'-bipyridyl derivatives with amide groups at the 5,5'-positions, are synthesized. The C-connected amide group bound to the bipyridyl ligand through the carbonyl carbon atom is twisted with respect to the bipyridyl plane, whereas the N-connected amide group is in the plane. DFT calculations reveal that the twisted structure of the C-connected amide group raises the level of the LUMO, which results in a negative shift of the first reduction potential (Ep ) of the ruthenium complex. The catalytic abilities for CO2 reduction are evaluated in photoreactions (λ>400 nm) with the ruthenium complexes (the catalyst), [Ru(bpy)3 ](2+) (bpy=2,2'-bipyridine; the photosensitizer), and 1-benzyl-1,4-dihydronicotinamide (the electron donor) in CO2 -saturated N,N-dimethylacetamide/water. The logarithm of the turnover frequency increases by shifting Ep a negative value until it reaches the reduction potential of the photosensitizer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CO2 cycle

Science.gov (United States)

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

2017-01-01

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

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

International Nuclear Information System (INIS)

Oldenburg, Curt M.; Lewicki, Jennifer L.

2005-01-01

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

A Multi-scale Approach for CO2 Accounting and Risk Analysis in CO2 Enhanced Oil Recovery Sites

Science.gov (United States)

Dai, Z.; Viswanathan, H. S.; Middleton, R. S.; Pan, F.; Ampomah, W.; Yang, C.; Jia, W.; Lee, S. Y.; McPherson, B. J. O. L.; Grigg, R.; White, M. D.

2015-12-01

Using carbon dioxide in enhanced oil recovery (CO2-EOR) is a promising technology for emissions management because CO2-EOR can dramatically reduce carbon sequestration costs in the absence of greenhouse gas emissions policies that include incentives for carbon capture and storage. This study develops a multi-scale approach to perform CO2 accounting and risk analysis for understanding CO2 storage potential within an EOR environment at the Farnsworth Unit of the Anadarko Basin in northern Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil-water flow and transport in the Marrow formation are conducted for global sensitivity and statistical analysis of the major risk metrics: CO2 injection rate, CO2 first breakthrough time, CO2 production rate, cumulative net CO2 storage, cumulative oil and CH4 production, and water injection and production rates. A global sensitivity analysis indicates that reservoir permeability, porosity, and thickness are the major intrinsic reservoir parameters that control net CO2 injection/storage and oil/CH4 recovery rates. The well spacing (the distance between the injection and production wells) and the sequence of alternating CO2 and water injection are the major operational parameters for designing an effective five-spot CO2-EOR pattern. The response surface analysis shows that net CO2 injection rate increases with the increasing reservoir thickness, permeability, and porosity. The oil/CH4 production rates are positively correlated to reservoir permeability, porosity and thickness, but negatively correlated to the initial water saturation. The mean and confidence intervals are estimated for quantifying the uncertainty ranges of the risk metrics. The results from this study provide useful insights for understanding the CO2 storage potential and the corresponding risks of commercial-scale CO2-EOR fields.

Alberta industrial synergy CO2 programs initiative

International Nuclear Information System (INIS)

Yildirim, E.

1998-01-01

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

Magnetoresistance in Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions.

Science.gov (United States)

Zhang, Han; Ye, Meng; Wang, Yangyang; Quhe, Ruge; Pan, Yuanyuan; Guo, Ying; Song, Zhigang; Yang, Jinbo; Guo, Wanlin; Lu, Jing

2016-06-28

Semiconducting single-layer (SL) and few-layer MoS2 have a flat surface, free of dangling bonds. Using density functional theory coupled with non-equilibrium Green's function method, we investigate the spin-polarized transport properties of Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions with MoS2 layer numbers of N = 1, 3, and 5. Well-defined interfaces are formed between MoS2 and metal electrodes. The junctions with a SL MoS2 spacer are almost metallic owing to the strong coupling between MoS2 and the ferromagnets, while those are tunneling with a few layer MoS2 spacer. Both large magnetoresistance and tunneling magnetoresistance are found when fcc or hcp Co is used as an electrode. Therefore, flat single- and few-layer MoS2 can serve as an effective nonmagnetic spacer in a magnetoresistance or tunneling magnetoresistance device with a well-defined interface.

CO2 Sequestration short course

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-08

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

Enzymes in CO2 Capture

DEFF Research Database (Denmark)

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

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

[Effects of plastic film mulching on soil CO2 efflux and CO2 concentration in an oasis cotton field].

Science.gov (United States)

Yu, Yong-xiang; Zhao, Cheng-yi; Jia, Hong-tao; Yu, Bo; Zhou, Tian-he; Yang, Yu-guang; Zhao, Hua

2015-01-01

A field study was conducted to compare soil CO2 efflux and CO2 concentration between mulched and non-mulched cotton fields by using closed chamber method and diffusion chamber technique. Soil CO2 efflux and CO2 concentration exhibited a similar seasonal pattern, decreasing from July to October. Mulched field had a lower soil CO2 efflux but a higher CO2 concentration, compared to those of non-mulched fields. Over the measurement period, cumulative CO2 efflux was 1871.95 kg C . hm-2 for mulched field and 2032.81 kg C . hm-2 for non-mulched field. Soil CO2 concentration was higher in mulched field (ranging from 5137 to 25945 µL . L-1) than in non- mulched field (ranging from 2165 to 23986 µL . L-1). The correlation coefficients between soil CO2 concentrations at different depths and soil CO2 effluxes were 0.60 to 0.73 and 0.57 to 0.75 for the mulched and non-mulched fields, indicating that soil CO2 concentration played a crucial role in soil CO2 emission. The Q10 values were 2.77 and 2.48 for the mulched and non-mulched fields, respectively, suggesting that CO2 efflux in mulched field was more sensitive to the temperature.

Analysis of CO2, CO and HC emission reduction in automobiles

Science.gov (United States)

Balan, K. N.; Valarmathi, T. N.; Reddy, Mannem Soma Harish; Aravinda Reddy, Gireddy; Sai Srinivas, Jammalamadaka K. M. K.; Vasan

2017-05-01

In the present scenario, the emission from automobiles is becoming a serious problem to the environment. Automobiles, thermal power stations and Industries majorly constitute to the emission of CO2, CO and HC. Though the CO2 available in the atmosphere will be captured by oceans, grasslands; they are not enough to control CO2 present in the atmosphere completely. Also advances in engine and vehicle technology continuously to reduce the emission from engine exhaust are not sufficient to reduce the HC and CO emission. This work concentrates on design, fabrication and analysis to reduce CO2, CO and HC emission from exhaust of automobiles by using molecular sieve 5A of 1.5mm. In this paper, the details of the fabrication, results and discussion about the process are discussed.

Analisis del signo de Hoover en relacion con parametros funcionales, radiologicos y de radio de curvatura en pacientes con enfermedad pulmonar obstructiva cronica

Directory of Open Access Journals (Sweden)

M. E. Capria

2003-10-01

Full Text Available El propósito del presente trabajo fue: 1 relacionar el signo de Hoover SH (+ con diversos parámetros funcionales (espirometría y volúmenes pulmonares y radiológicos (radiografías posteroan-teriores, 2 caracterizar los cambios en el radio de curvatura y la eficiencia del diafragma, y restablecer relaciones con los parámetros funcionales y radiológicos. Se estudiaron 15 pacientes con EPOC (SH (+, n: 8. El radio de curvatura fue determinado en el hemidiafragma derecho en inspiración y espiración máximas. Los SH(+ se hallaron más severamente obstruidos (VEF1%, p 0.005% y con mayor atrapamiento aéreo (VR/CPT %, p 0.01. El radio espiratorio (Re fue mayor (p 0.05, y su eficiencia (1/Re, fue menor (p 0.05. El VEF1% correlacionó con el grado de hiperinflación según CPT % (r -0.58, p 0.022 y con el atrapamiento aéreo según VR% (r -0.77, p 0.0008. Los pacientes con menor VEF1% presentaron un Re mayor (r -0. 61, p 0.015 y menor eficiencia diafragmática en espiración (1/Re de acuerdo a: 1/Re = 0.093 cm-1 + 0.0012 cm-1 * VEF1% (r 0.688, p 0.0054. El VEF1 correlacionó con la movilidad diafragmática (r 0.71, p 0.003. La PaCO2 correlacionó con la CPT % (r 0.534, p 0.04, con el VR % (r 0.62, p 0.014 y con los parámetros radiológicos de hiperinflación (r 0.546, p 0.035 y atrapamiento aéreo (r 0.528, p 0.043. El SH(+ sugiere obstrucción bronquial severa, aplanamiento del diafragma, consiguiente aumento del radio de curvatura, menor movilidad y menor eficiencia.The purpose of the present study was: 1 to relate the Hoover sign -SH (+- with several functional (spirometry and lung volumes and radiographic (AP x-ray parameters, 2 to characterize the changes in diaphragmatic curvature radius and the efficiency and to establish some relationships with the functional and radiographic parameters. Fifteen patients with COPD (SH (+, n: 8 were studied. The radius was determined in the right hemidiaphragm after maximal inspired and expired x-ray. The

Potential and economics of CO{sub 2} sequestration; Sequestration du CO{sub 2}: faisabilite et cout

Energy Technology Data Exchange (ETDEWEB)

Jean-Baptiste, Ph.; Ciais, Ph.; Orr, J. [CEA Saclay, 91 - Gif sur Yvette (France). Direction des Sciences de la Matiere; Ducroux, R. [Centre d' Initiative et de Recherche sur l' Energie et l' Environnement, CIRENE, 91 - Palaiseau (France)

2001-07-01

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

Interface characteristics in Co2MnSi/Ag/Co2MnSi trilayer

International Nuclear Information System (INIS)

Li, Yang; Chen, Hong; Wang, Guangzhao; Yuan, Hongkuan

2016-01-01

Highlights: • Inferface DO 3 disorder is most favorable in Co 2 MnSi/Ag/Co 2 MnSi trilayer. • Interface itself and inferface DO 3 disorder destroy the half-metallicity of interface layers. • Magnetoresistance is reduced by the interface itself and interface disorder. • Magnetotransport coefficient is largely reduced by the interface itself and interface disorder. - Abstract: Interface characteristics of Co 2 MnSi/Ag/Co 2 MnSi trilayer have been investigated by means of first-principles. The most likely interface is formed by connecting MnSi-termination to the bridge site between two Ag atoms. As annealed at high temperature, the formation of interface DO 3 disorder is most energetically favorable. The spin polarization is reduced by both the interface itself and interface disorder due to the interface state occurs in the minority-spin gap. As a result, the magneto-resistance ratio has a sharp drop based on the estimation of a simplified modeling.

Effects of atmospheric CO2 enrichment on soil CO2 efflux in a young longleaf pine system

Science.gov (United States)

Elevated atmospheric carbon dioxide (CO2) can affect the quantity and quality of plant tissues which will impact carbon (C) cycling and storage in plant/soil systems and the release of CO2 back to the atmosphere. Research is needed to quantify the effects of elevated CO2 on soil CO2 efflux to predi...

Natural Analogues of CO2 Geological Storage; Analogos Naturales del Almacenamiento Geologico de CO2

Energy Technology Data Exchange (ETDEWEB)

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

2007-07-20

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

Improved solar-driven photocatalytic performance of Ag_2CO_3/(BiO)_2CO_3 prepared in-situ

International Nuclear Information System (INIS)

Zhong, Junbo; Li, Jianzhang; Huang, Shengtian; Cheng, Chaozhu; Yuan, Wei; Li, Minjiao; Ding, Jie

2016-01-01

Highlights: • Ag_2CO_3/(BiO)_2CO_3 photocatalysts were prepared in-situ. • The photo-induced charge separation rate has been greatly increased. • The photocatalytic activity has been greatly promoted. - Abstract: Ag_2CO_3/(BiO)_2CO_3 composites have been fabricated in-situ via a facile parallel flaw co-precipitation method. The specific surface area, structure, morphology, and the separation rate of photo-induced charge pairs of the photocatalysts were characterized by Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy(DRS), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and surface photovoltage (SPV) spectroscopy, respectively. XRD patterns and DRS demonstrated that Ag_2CO_3 has no effect on the crystal phase and bandgap of (BiO)_2CO_3. The existence of Ag_2CO_3 in the composites enhances the separation rate of photo-induced charge pairs of the photocatalysts. The photocatalytic performance of Ag_2CO_3/(BiO)_2CO_3 was evaluated by the decolorization of methyl orange (MO) aqueous solution under simulated solar irradiation. It was found that the simulated solar-induced photocatalytic activity of Ag_2CO_3/(BiO)_2CO_3 copmposites was significantly improved, which was mainly attributed to the enhanced surface area and the separation rate of photo-induced charge pairs.

Implications of overestimated anthropogenic CO2 emissions on East Asian and global land CO2 flux inversion

Science.gov (United States)

Saeki, Tazu; Patra, Prabir K.

2017-12-01

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

Stored CO2 and Methane Leakage Risk Assessment and Monitoring Tool Development: CO2 Capture Project Phase 2 (CCP2)

Energy Technology Data Exchange (ETDEWEB)

Dan Kieki

2008-09-30

The primary project goal is to develop and test tools for optimization of ECBM recovery and geologic storage of CO{sub 2} in coalbeds, in addition to tools for monitoring CO{sub 2} sequestration in coalbeds to support risk assessment. Three critical topics identified are (1) the integrity of coal bed methane geologic and engineered systems, (2) the optimization of the coal bed storage process, and (3) reliable monitoring and verification systems appropriate to the special conditions of CO{sub 2} storage and flow in coals.

Air-ice CO2 fluxes and pCO2 dynamics in the Arctic coastal area (Amundsen Gulf, Canada)

Science.gov (United States)

Geilfus, Nicolas-Xavier; Tison, Jean Louis; Carnat, Gauthier; Else, Brent; Borges, Alberto V.; Thomas, Helmuth; Shadwick, Elizabeth; Delille, Bruno

2010-05-01

Sea ice covers about 7% of the Earth surface at its maximum seasonal extent. For decades sea ice was assumed to be an impermeable and inert barrier for air - sea exchange of CO2 so that global climate models do not include CO2 exchange between the oceans and the atmosphere in the polar regions. However, uptake of atmospheric CO2 by sea ice cover was recently reported raising the need to further investigate pCO2 dynamics in the marine cryosphere realm and related air-ice CO2 fluxes. In addition, budget of CO2 fluxes are poorly constrained in high latitudes continental shelves [Borges et al., 2006]. We report measurements of air-ice CO2 fluxes above the Canadian continental shelf and compare them to previous measurements carried out in Antarctica. We carried out measurements of pCO2 within brines and bulk ice, and related air-ice CO2 fluxes (chamber method) in Antarctic first year pack ice ("Sea Ice Mass Balance in Antarctica -SIMBA" drifting station experiment September - October 2007) and in Arctic first year land fast ice ("Circumpolar Flaw Lead" - CFL, April - June 2008). These 2 experiments were carried out in contrasted sites. SIMBA was carried out on sea ice in early spring while CFL was carried out in from the middle of the winter to the late spring while sea ice was melting. Both in Arctic and Antarctic, no air-ice CO2 fluxes were detected when sea ice interface was below -10°C. Slightly above -10°C, fluxes toward the atmosphere were observed. In contrast, at -7°C fluxes from the atmosphere to the ice were significant. The pCO2 of the brine exhibits a same trend in both hemispheres with a strong decrease of the pCO2 anti-correlated with the increase of sea ice temperature. The pCO2 shifted from a large over-saturation at low temperature to a marked under-saturation at high temperature. These air-ice CO2 fluxes are partly controlled by the permeability of the air-ice interface, which depends of the temperature of this one. Moreover, air-ice CO2 fluxes are

Simulation and modeling CO2 absorption in biogas with DEA promoted K2CO3 solution in packed column

Science.gov (United States)

Nurkhamidah, Siti; Altway, Ali; Airlangga, Bramantyo; Emilia, Dwi Putri

2017-05-01

Absorption of carbon dioxide (CO2) using potassium carbonate (K2CO3) is one of biogas purification method. However, K2CO3 have slow mass transfer in liquid phase. So it is necessary to eliminate the disadvantage of CO2 absorption using K2CO3 by adding promotor (activator). Diethanol amine (DEA) is one of promotor which can increase its reaction rate. Simulation and modeling research of the CO2 absorption from biogas with DEA promoted K2CO3 solution has not been conducted. Thus, the main goal of this research is create model and simulation for the CO2 absorption from biogas with DEA promoted K2CO3 solution, then observe the influence of promoter concentration. DEA concentration varies between 1-5 %wt. From the simulation, we concluded that the CO2 removal rise with the increasing of promoter concentration. The highest CO2 removal is 54.5318 % at 5 % wt DEA concentration.

Evasion of CO{sub 2} injected into the ocean in the content of CO{sub 2} stabilization

Energy Technology Data Exchange (ETDEWEB)

Kheshgi, H.S. [ExxonMobil Research and Engineering Co., Annandale, NJ (United States)

2004-08-01

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

Evasion of CO{sub 2} injected into the ocean in the context of CO{sub 2} stabilization

Energy Technology Data Exchange (ETDEWEB)

Kheshgi, Haroon S

2004-08-01

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

Geochemical Interaction of Middle Bakken Reservoir Rock and CO2 during CO2-Based Fracturing

Science.gov (United States)

Nicot, J. P.; Lu, J.; Mickler, P. J.; Ribeiro, L. H.; Darvari, R.

2015-12-01

This study was conducted to investigate the effects of geochemical interactions when CO2 is used to create the fractures necessary to produce hydrocarbons from low-permeability Middle Bakken sandstone. The primary objectives are to: (1) identify and understand the geochemical reactions related to CO2-based fracturing, and (2) assess potential changes of reservoir property. Three autoclave experiments were conducted at reservoir conditions exposing middle Bakken core fragments to supercritical CO2 (sc-CO2) only and to CO2-saturated synthetic brine. Ion-milled core samples were examined before and after the reaction experiments using scanning electron microscope, which enabled us to image the reaction surface in extreme details and unambiguously identify mineral dissolution and precipitation. The most significant changes in the reacted rock samples exposed to the CO2-saturated brine is dissolution of the carbonate minerals, particularly calcite which displays severely corrosion. Dolomite grains were corroded to a lesser degree. Quartz and feldspars remained intact and some pyrite framboids underwent slight dissolution. Additionally, small amount of calcite precipitation took place as indicated by numerous small calcite crystals formed at the reaction surface and in the pores. The aqueous solution composition changes confirm these petrographic observations with increase in Ca and Mg and associated minor elements and very slight increase in Fe and sulfate. When exposed to sc-CO2 only, changes observed include etching of calcite grain surface and precipitation of salt crystals (halite and anhydrite) due to evaporation of residual pore water into the sc-CO2 phase. Dolomite and feldspars remained intact and pyrite grains were slightly altered. Mercury intrusion capillary pressure tests on reacted and unreacted samples shows an increase in porosity when an aqueous phase is present but no overall porosity change caused by sc-CO2. It also suggests an increase in permeability

CO2-laser fusion

International Nuclear Information System (INIS)

Stark, E.E. Jr.

1978-01-01

The basic concept of laser fusion is described, with a set of requirements on the laser system. Systems and applications concepts are presented and discussed. The CO 2 laser's characteristics and advantages for laser fusion are described. Finally, technological issues in the development of CO 2 laser systems for fusion applications are discussed

CO2 emission calculations and trends

International Nuclear Information System (INIS)

Boden, T.A.; Marland, G.; Andres, R.J.

1995-01-01

Evidence that the atmospheric CO 2 concentration has risen during the past several decades is irrefutable. Most of the observed increase in atmospheric CO 2 is believed to result from CO 2 releases from fossil-fuel burning. The United Nations (UN) Framework Convention on Climate Change (FCCC), signed in Rio de Janeiro in June 1992, reflects global concern over the increasing CO 2 concentration and its potential impact on climate. One of the convention's stated objectives was the ''stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. '' Specifically, the FCCC asked all 154 signing countries to conduct an inventory of their current greenhouse gas emissions, and it set nonbinding targets for some countries to control emissions by stabilizing them at 1990 levels by the year 2000. Given the importance of CO 2 as a greenhouse gas, the relationship between CO 2 emissions and increases in atmospheric CO 2 levels, and the potential impacts of a greenhouse gas-induced climate change; it is important that comprehensive CO 2 emissions records be compiled, maintained, updated, and documented

CO2 storage in Sweden

International Nuclear Information System (INIS)

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

2004-07-01

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

Detection of CO2 leaks from carbon capture and storage sites with combined atmospheric CO2 and O-2 measurements

NARCIS (Netherlands)

van Leeuwen, Charlotte; Meijer, Harro A. J.

2015-01-01

This paper presents a transportable instrument that simultaneously measures the CO2 and (relative) O-2 concentration of the atmosphere with the purpose to aid in the detection of CO2 leaks from CCS sites. CO2 and O-2 are coupled in most processes on earth (e.g., photosynthesis, respiration and

In-depth numerical analysis on the determination of amount of CO2 recirculation in LNG/O2/CO2 combustion

International Nuclear Information System (INIS)

Kim, Hey-Suk; Shin, Mi-Soo; Jang, Dong-Soon; Lee, Dae Keun

2010-01-01

The determination of proper amount of CO 2 recirculation is one of the critical issues in oxy-fuel combustion technology for the reduction of CO 2 emissions by the capture and sequestration of CO 2 species in flue gas. The objective of this study is to determine the optimum value of O 2 fraction in O 2 /CO 2 mixture to obtain similar flame characteristics with LNG-air combustion. To this end, a systematic numerical investigation has been made in order to resolve the physical feature of LNG/O 2 /CO 2 combustion. For this, SIMPLEC algorithm is used for the resolution of pressure velocity coupling. And for the Reynolds stresses and turbulent reaction the popular two-equation (k-ε) model by Launder and Spalding and eddy breakup model by Magnussen and Hjertager were incorporated, respectively. The radiative heat transfer is calculated from the volumetric energy loss rate from flame, considering absorption coefficient of H 2 O, CO 2 and CO gases. A series of parametric investigation has been made as function of oxidizer type, O 2 fraction and fuel type for the resolution of combustion characteristics such as flame temperature, turbulent mixing and species concentration. Further the increased effect of CO 2 species on the flame temperature is carefully examined by the consideration of change of specific heat and radiation effect. Based on this study, it was observed that the same mass flow rate of CO 2 with N 2 appears as the most adequate value for the amount of CO 2 recirculation for LNG fuel since the lower C p value for the CO 2 relative to N 2 species at lower temperatures cancels the effect of the higher C p value at higher temperatures over the range of flame temperatures present in this study. However, for the fuel with high C/H ratio, for example of coal, the reduced amount of CO 2 recirculation is recommended in order to compensate the increased radiation heat loss. In general, the calculation results were physically acceptable and consistent with reported data