Oxygen-pressure method

Perturbation by Paramagnetic Species, the Oxygen Pressure Method... 

ASTM D3632-98 Standard practice for accelerated aging of adhesive joints by the oxygen-pressure method. 

D 3632 Standard Test Method for Accelerated Aging of Adhesive Joints by the Oxygen-Pressure Method D 6396 Standard Test Method for Testing of Pipe Thread Sealants on Pipe Tees... 

Bomb Method the sample is burned in a bomb under oxygen pressures of 30 bar. The sulfur contained in the wash water is analyzed via gravimetry as barium sulfate. 

A common method for fixing the oxygen pressure at such low values in a system is to use a gas mixture comprising CO and C02 or H2 and H20. A C0-C02 mixture results in the reaction... 

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. 

If one assumes that the reaction system is at thermodynamic equilibrium, the oxygen electrode method also allows one to infer the partial pressure of oxygen in equilibrium with the test solution. 

Ray and Chanda [261] studied bismuth molybdates (prepared by the method of Peacock [250,251]) in an integral flow reactor. At constant W/F = 8 g h mol-1 and a feed ratio isobutene/oxygen = 1/6, a maximum selectivity of 75% was found at 400—450°C. As with propene, the reaction is first order with respect to isobutene and the rate is independent of the oxygen pressure. The reoxidation of the catalyst is very fast. Assuming that the kinetics can be described by three parallel first-order reactions for the production of methacrolein, carbon monoxide and carbon dioxide, rate coefficients were calculated (Table 18). 

---