Search results for "Partial Pressure"
showing 10 items of 145 documents
Ventilation-Perfusion Ratio in Perflubron During Partial Liquid Ventilation
2010
BACKGROUND: Functional magnetic resonance imaging (fMRI) of fluorine-19 allows for the mapping of oxygen partial pressure within perfluorocarbons in the alveolar space (Pao(2)). Theoretically, fMRI-detected Pao(2) can be combined with the Fick principle approach, i.e., a mass balance of oxygen uptake by ventilation and delivery by perfusion, to quantify the ventilation-perfusion ratio (Va/Q) of a lung region: The mixed venous blood and the inspiratory oxygen fraction, which are equal for all lung regions, are measured. In addition, the local expiratory oxygen fraction and the end capillary oxygen content, both of which may differ between the lung regions, are calculated using the fMRI-detec…
Estimation of the emission temperature of an electrodeless discharge lamp and determination of the oscillator strength for the I(2P3/2) 183.038 nm re…
2001
Abstract The 183.038 nm resonance absorption transition of I( 2 P 3/2 ) has been studied using a flash photolysis set-up for gas-phase chemistry and a radio frequency powered electrodeless discharge lamp filled with iodine. The dependence of self-absorption and self-reversal on iodine partial pressure in the discharge volume was measured. The optimum iodine partial pressure, with self-absorption minimized and acceptable intensity, is determined to be approximately 2.5×10 −3 mbar. A method is described to estimate the temperature of the emitting atoms using direct measurements of relative absorption at different absorber concentrations. This yields an emission temperature of 923±50 K. Using …
Experimental investigation of the grain size dependence of the hydrolysis of LiH powder
2011
International audience; The hydrolysis reaction of LiH powder has been investigated in order to determine the products, rates and mechanisms of this reaction and the influence of the experimental parameters. Raman spectroscopy, X-ray diffraction and gravimetric analysis were used. It was shown that the product of hydrolysis was the hydroxide of lithium (LiOH) for low partial pressure of water (≈50 Pa) and LiOH*H2O for a higher partial pressure of water (>2000 Pa). Moreover, data obtained using gravimetric analysis inside a glove box containing a controlled partial pressure of water (500 ppmv/50 Pa at 25 °C) were used to determine the rate of the reaction versus particle size. The experiment…
Growth rates of F0 and F1 larval and juvenile European seabass Dicentrarchus labrax in resonse to ocean acidification and warming
2022
Ongoing climate change is leading to warmer and more acidic oceans. The future distribution of fish within the oceans depends on their capacity to adapt to these new environments. Only few studies have examined the effects of ocean acidification (OA) and warming (OW) on the metabolism of long-lived fish over successive generations. We therefore aimed to investigate the effect of OA on larval and juvenile growth and metabolism on two successive generations of European sea bass (Dicentrarchus labrax L.) as well as the effect of OAW on larval and juvenile growth and metabolism of the second generation. European sea bass is a large economically important fish species with a long generation time…
Application of Geostatistical Tools to the Geochemical Characterization of the Peloritani Mts (Sicily, Italy) Aquifers
2021
Sources of groundwater contaminants in inhabited areas, located in complex geo-tectonic contexts, are often deeply interlocked, thus, making the discrimination between anthropic and natural origins difficult. In this study, we investigate the Peloritani Mountain aquifers (Sicily, Italy), using the combination of probability plots with concentration contour maps to retrieve an overall view of the groundwater geo-chemistry with a special focus on the flux of heavy metals. In particular, we present a methodology for integrating spatial data with very different levels of precision, acquired before and during the “geomatic era”. Our results depict a complex geochemical layout driven by a geo-puz…
Ein Extrapolationsverfahren zur unblutigen Bestimmung des O2-und CO2-Partialdruckes im ven�sen Mischblut
1969
Es wird eine neue Methode zur unblutigen Messung des O2-und des CO2-Partialdruckes im venosen Mischblut beschrieben. Dabei inspiriert der Proband zunachst ein Atemzugvolumen eines Gasgemisches mit 10–13 Vol-% CO2 und dem Rest N2. Am Ende der folgenden Exspiration wird vom offenen auf ein geschlossenes respiratorisches System umgeschaltet, dessen Ruckatmungsbeutel anfanglich 1,5–2,5 l eines Gemisches von 5,5–7,5 Vol-% CO2 und N2 als Rest enthalt. Eine schnellregistrierende Platinelektrode und ein Ultrarotabsorptionsschreiber analysieren fortlaufend die respiratorischen O2-und CO2-Partialdruckanderungen am Mundstuck des Probanden. Die Umhullenden der wahrend der Ruckatmung aufgezeichneten Kur…
Water vapour solubility and conductivity study of the proton conductor BaCe(0.9−x)ZrxY0.1O(3−δ)
2009
Abstract The perovskite BaCe(0.9 − x)ZrxY0.1O(3 − δ) has been prepared by solid state reaction at 1400 °C and conventional sintering at 1700 °C. Water uptake experiments performed between 400 and 600 °C, at a water vapour pressure of 0.02 atm, provide data on the concentration of protons incorporated in the sample. The direct current conductivity has been measured as a function of oxygen partial pressure, at a water vapour partial pressure of 0.015 atm. The total conductivity has been resolved into a p-type and an ionic component using a fitting procedure appropriate to the assumed defect model. An estimation of the protonic component was made by assuming a conductivity isotope effect betwe…
Structural and conductivity study of the proton conductor BaCe(0.9−x)ZrxY0.1O(3−ı) at intermediate temperatures.
2009
International audience; The perovskite BaCe(0.9−x)ZrxY0.1O(3−ı) is prepared by solid-state reaction at 1400 ◦C and sintering at 1700 ◦C. It is characterised using X-ray diffraction, Raman spectroscopy and electrical measurements. A distortion fromthe cubic structure at roomtemperature is noticeable in the Raman spectra for 0.2 < x < 0.8, but not in the X-ray diffraction patterns. This work points out the rhombohedral nature of this distortion. Phase transitions are studied up to 600 ◦C. The direct current conductivity is measured as a function of oxygen partial pressure, and at a water vapour partial pressure of 0.015 atm. The total conductivity is resolved into an ionic and a p-type compon…
The Interdependence of Respiratory Gas Values and pH as a Function of Base Excess in Human Blood at 37°C
1973
The accurate estimation of the transport function of human blood for respiratory gases as well as the respiratory gas exchange in human body requires detailed knowledge of the respiratory gas partial pressures and the acid-base status in the blood. Because there is an interdependence between the different respiratory gas parameters described as Bohr and Haldane effect (3,4), it is possible to obtain a general picture of the whole transport system, if these interrelations are known.
The role of the aquifer in soil CO2 degassing in volcanic peripheral areas: A case study of Stromboli Island (Italy)
2017
Abstract The peripheral area of Stromboli Island, Italy, named “Scari”, was continuously studied between January 2009 and December 2010. Data on soil CO 2 flux and the partial pressure of CO 2 (pCO 2 ) in equilibrium with the thermal aquifer linked to the magmatic system are presented. Soil CO 2 fluxes range from 20 to 370 g m − 2 d − 1 and have been strongly affected by soil temperature variations. Soil CO 2 flux data were filtered with respect to the soil temperature and the calculated values, called “residuals”, were considered to detect changes induced by the magmatic system. The pCO 2 values change in a wide range from 0.03 to 0.6 (atm), showing rapid variations. The results of this s…