Oxygen pressure measurement

A circulation vapor source similar to the DECOR source previously studied was placed inside a cube converter attached to the TOFMS as explained above. This cube also featured an oxygen detector to get independent oxygen pressure measurements. 

The development of the oxygen pressure measiuement method allowed for the first time to measure the vajjor pressure of active species inside an operating converter. Finally the sampling of the gas phase generated by a DECOR source, combined with oxygen pressure measurements, provided a detailed picture of thegas phase of a converter with oxygen-enhanced performance. 

The flask was transferred to a water thermostat at 35.0°C. in a dark room, and the reaction allowed to proceed. At convenient intervals the flask was removed, the oxides of nitrogen frozen out rapidly with liquid air, and the oxygen pressure measured by the quartz manometer. At the end of a nm complete decomposition was obtained by leaving the flask over night at 60°C. 

The results of in-pile autoclave experiments indicated corrosion rates under irradiation which are in general agreement with those determined in in-pile loop experiments. The oxygen pressure measurements in autoclave experiments indicate that the rate of attack remains constant at a given set of in-pile conditions [75]. 

Fig. 9.9 Discharge curves of Li//Mo03 microcells including thin films deposited by rf-sputtering method onto nickel substrate as a function of the partial oxygen pressure. Measurements were carried out at current densities 20 pA cm ...

Analytical Procedures. Oxygen difluoride may be determined conveniently by quantitative appHcation of k, nmr, and mass spectroscopy. Purity may also be assessed by vapor pressure measurements. Wet-chemical analyses can be conducted either by digestion with excess NaOH, followed by measurement of the excess base (2) and the fluoride ion (48,49), or by reaction with acidified KI solution, followed by measurement of the Hberated I2 (4). 

Probably the most comprehensive measurements of the effect of voids on rates are those of Cohen "" and his school. They have published data on the oxidation of pure irons for a wide temperature range and for oxygen pressures ranging from 1-3 x 10 "N/m to lOOkN/m. The interactions between void formation and oxygen uptake are complex but only at pressures below 1 3 X 10 N/m do voids have no effect. Some of their results are summarised in Fig. 1.85 over the pressure range 1-3 x 10 N/m to... 

Measurement of the oxygen pressure or oxygen potential near stoichiometry. 

Measurement of the equilibrium oxygen pressure as functions of both x and T at higher temperatures than are currently available. 

A different situation arises with a preliminary reduced surface. In this case the measured value of y is within lO - 10 2, and as the temperature increases, the y grows by the Arrhenius Law (Equation) with the activation energy of 5.2 kcal/mole. In addition, there is dependence of y upon the triplet oxygen pressure in the set-up, though the experiment conditions allow us to neglect a priori the impact of homogeneous processes on the spatial distribution of 02( A ) molecules. Prolonged... 

The partial oxygen pressure, p02, is particularly significant in metabolic processes of cells, and its variation from normal values often indicates pathologies (ischemic diseases, strokes, tumors). Accurate and localized measurements of the oxygen concentration are also desirable for differentiation between venous and arterial blood, or for cerebral mapping of task activation. In the past, invasive methods were used involving oxygen-sensitive electrodes which had to be placed directly in the blood or tissue and could only offer p02 from a few body points. 

The partial oxygen pressure was checked with an OP-210/3 microanalyser [20] before and after the bubbling of oxygen through the electrolyte. The potential was measured against an Ag/AgCl reference electrode. 

A conductivity cell is set up using an yttria-stabilized zirconia electrolyte. At 900°C the equilibrium pressure in the cell was 1.02 x 10-10 atm, and the reference pressure outside the cell was 7.94 x 10 18 atm. (a) What is the cell voltage The temperature was dropped to 800°C and the reference pressure changed to 1.61 x 10-19 atm. The measured equilibrium voltage was 946 mV. (b) What is the equilibrium oxygen pressure in the cell [Data adapted from D-K. Lee et al., J. Solid State Chem., 178, 185-193 (2005).]... 

The partial pressure of oxygen is measured with a gas detector in the atmosphere of a sewer network and found to be equal to 0.18 atm. This value is, probably because of oxygen consumption of the wastewater and limited ventilation, slightly lower than in the city atmosphere, where it was measured at 0.21 atm. Determine at 25°C the solubility of 02 (i.e., at equilibrium conditions) in the wastewater (considered as water) of the sewer. 

Atmospheres were within a few percent of nominal concentrations the mean oxygen concentration was approximately 20.5%. No significant or consistent differences were found between air exposure and test chemical exposure for clinical observations, blood pressure, heart rate, peak expiratory flow, or EKG recordings. During blood sampling and blood pressure measurements, all subjects showed sinus arrhythmia before and after exposure. 

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