Search results for "CO2"
showing 10 items of 402 documents
Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2 gradient
2016
Volcanic CO2 seeps provide opportunities to investigate the effects of ocean acidification on organisms in the wild. To understand the influence of increasing CO2 concentrations on the metabolic rate (oxygen consumption) and the development of ocellated wrasse early life stages, we ran two field experiments, collecting embryos from nesting sites with different partial pressures of CO2 [pCO2; ambient (400 µatm) and high (800-1000 µatm)] and reciprocally transplanting embryos from ambient- to high-CO2 sites for 30 h. Ocellated wrasse offspring brooded in different CO2 conditions had similar responses, but after transplanting portions of nests to the high-CO2 site, embryos from parents that sp…
Can Green Dimethyl Carbonate Synthesis be More Effective? A Catalyst Recycling Study Benefiting from Experimental Kinetics and DFT Modeling
2014
Dibutyldimethoxystannanes are known to catalyze the reaction between carbon dioxide and methanol leading to dimethyl carbonate. Despite similarities between din-butyl- and ditert-butyldimethoxystannane, the recycled complexes have different structural features. In the din-butyl series, a decatin(IV) complex has been characterized and is less active than the stannane precursor. Kinetic experiments likely indicate that all the tin centers are not active, which is confirmed in comparing with the related dinuclear 1,3-dimethoxytetran-butyldistannoxane complex. In the ditert-butyl series, the tritin(IV) complex isolated upon recycling features the steric effect of bulky tBu ancillary ligands. In…
Electrochemical reduction of carbon dioxide to formic acid at a tin cathode in divided and undivided cells: effect of carbon dioxide pressure and oth…
2016
Abstract The reduction of carbon dioxide to formic acid at a tin cathode was studied in both divided and undivided cells. In the first stage of the study, the effect of some operating parameters, including the working potential and the nature of the supporting electrolyte and of the cathode, on both the cathodic reduction of CO2 and the anodic oxidation of formic acid was investigated in a divided cell. In a second stage, the reduction of carbon dioxide was performed in an undivided cell with the aim of studying the effect on the generation of formic acid of various operating parameters such as current density, cathode to anode area ratio, mixing rate and nature of the anode and of the supp…
The instability of the adjusted and unadjusted environmental Kuznets curves
2006
We test the stability of the unadjusted and adjusted environmental Kuznets curves (EKCs). Our results provide evidence in favour of a theoretically funded "adjusted EKC hypothesis" in which the impact of per capita GDP on CO2 emissions is evaluated conditionally to the effects of the industry mix and of the energy-supply infrastructure. In this specification, the shape of the GDP-CO2 relationship appears quite sensitive to changes in the estimation period. In the final part of the paper, signs and dynamics of fixed effects of individual countries in different specifications are interpreted as measures of virtuous or vicious of environmental behaviour. © 2006 Elsevier B.V. All rights reserve…
Performance of EasyBreath® Decathlon Snorkeling mask for Delivering Continuous Positive Airway Pressure
2020
ABSTRACTBackgroundDuring the COVID-19 pandemic, the need for noninvasive respiratory support devices has dramatically increased, sometimes exceeding hospital capacity. The full-face Decathlon snorkeling mask, EasyBreath® (EB® mask), has been adapted to deliver continuous positive airway pressure (CPAP) as an emergency respiratory interface. We aimed to assess the performance of this modified EB® mask.MethodsCPAP set at 5, 10, and 15 cmH2O was delivered to 10 healthy volunteers with a high-flow system generator set at 40, 80, and 120 L min-1 and with a turbine-driven ventilator during both spontaneous and loaded (resistor) breathing. Inspiratory CO2 partial pressure (PiCO2), pressure inside …
How trigeminal, taste and aroma perceptions are affected in mint-flavored carbonated beverages
2010
; The integration of olfactory, taste and trigeminal perceptions must be taken into account to better understand the perception of beverages. To do this, seven beverages were formulated to investigate the role of ingredients on trigeminal perception. All mutual interactions between olfactory, gustatory and trigeminal perceptions were studied. Instrumental measurements and sensory evaluation were used to elucidate both physicochemical and sensory interactions. Sensory profiling was conducted according to monadic product presentation, and in vivo aroma release was assessed in the nasal cavities of subjects during beverage consumption. This study further revealed the influence of trigeminal p…
Duvalo “Volcano” (North Macedonia): A Purely Tectonic‐Related CO 2 Degassing System
2022
Duvalo “volcano” is a site of anomalous geogenic degassing close to Ohrid (North Macedonia) not related to volcanic activity, despite its name. CO2 flux measurements made with the accumulation chamber (321 sites over ∼50,000 m2) showed fluxes up to nearly 60,000 g m-2 d-1, sustaining a total output of ∼67 t d-1. Soil gas samples were taken at 50 cm depth from sites with high CO2 fluxes and analyzed for their chemical and isotope composition. The gas is mainly composed by CO2 (> 90%) with significant concentrations of H2S (up to 0.55 %) and CH4 (up to 0.32 %). The isotope compositions of He (R/RA 0.10) and of CO2 (δ13C ∼0‰) exclude significant mantle contribution, while δ13C-CH4 (∼ -35‰) …
Effect of arterial oxygen tension on cerebral blood flow at different levels of arterial PCO2.
1970
Die Wirkung des arteriellen O2-Partialdruckes auf die Durchblutung des Grosshirns, Kleinhirns und Hirnstammes bei normalen und erhohten CO2-Partialdrucken im arteriellen Blut wird an der anaesthesierten Katze untersucht. Die Wirkung des PaO2 ist von der Hohe des PaCO2 abhangig.
Characterization and reactivity of charcoal from high temperature pyrolysis (800-1600°C)
2019
This study presents the effect of wood origin and heat treatment temperature on the CO2 reactivity, nanostructure and carbon chemistry of chars prepared at 800, 1200, and 1600 °C in slow pyrolysis reactors. The structure of charcoal was characterized by transmission electron microscopy, Raman spectroscopy, mercury intrusion porosimetry and N2 adsorption. The CO2 reactivity of char was investigated by thermogravimetric analysis. Results showed that spruce and oak chars have similar reactivity at all heat treatment temperatures. The oak char prepared at 1600 °C contained long and flat graphene layers and interplanar distance that is similar to graphite and thus, was more ordered t…
Photocatalytic membranes based on TiO2 catalysts and fluorinated polymers for CO2 conversion
2015
In this work, prepared TiO2–Nafion™-based membranes were used in a photocatalytic membrane reactor, operated in continuous mode, for converting CO2 to methanol.