Oxygen levels, control

The oxygen level in primary tantalum powder can be also increased by adjustment of the reduction process parameters [594] or by controlled stepwise additions of sodium to the reactor [595]. 

There several DO probes available. Some well-known branded fermenters, like New Brunswick, Bioflo series and the B. Braun Biotstat B fermenters are equipped with a DO meter. This unit has a 2 litre fermentation vessel equipped with DO meter and pH probe, antifoam sensor and level controllers for harvesting culture. The concentration of DO in the media is a function of temperature. The higher operating temperature would decrease the level of DO. A micro-sparger is used to provide sufficient small air bubbles. The air bubbles are stabilized in the media and the liquid phase is saturated with air. The availability of oxygen is major parameter to be considered in effective microbial cell growth rate. 

These features may indeed provide cost-effectiveness and other tangible benefits however, unless the boiler plant operates constantly and FW quality remains consistent, these benefits are unlikely to be fully realized. Where operating conditions vary, the use of multiblend programs exposes the potential for constant readjustment, poor waterside treatment (scales, deposits, oxygen pitting, etc.), and water-level control problems. 

Coleman, A. S. and Holland, H. D. (in press, January 2000). The global diagenetic flux of phosphorus from marine sediments to the oceans redox sensitivity and the control of atmospheric oxygen levels. In "Marine Authigenesis from Microbial to Global" (C. R. Glenn, L. Prevot-Lucas and J. Lucas, eds), SEPM Publication No. 66. 

Such results constitute a warning for the management of water supply systems based on reservoirs. Considering the major role of streamflow on controlling oxygen levels, water scarcity should be viewed as a threat not only for the quantity of resource, but also for its quality and the cost of treatment. All these... 

If refined products, such as gasoline, diesel, jet fuel, or kerosene, are transported in a pipeline, where otherwise sour hydrocarbon fluids are transported, there may be an undesired enrichment of sulfur in the refined products. This can be avoided if the oxygen level of the transportant is maintained at below 20 ppm [570]. The dissolved oxygen level in the hydrocarbon product is controlled by reducing the amount of air injection employed in mercaptan or disulfide reduction or by the use of oxygen scavengers prior to the introduction of the refined hydrocarbon product into the pipeline. 

Biochemical reactions must cater for living systems and as a result are carried out in an aqueous medium within a narrow range of conditions. Each species of microorganism grows best under certain conditions. Temperature, pH, oxygen levels, concentrations of reactants and products and possibly nutrient levels must be carefully controlled for optimum operation. 

O Mahony F.C., O Riordan T.C., Papkovskaia N., Kerry J.P., Papkovsky D.B., Nondestructive assessment of oxygen levels in industrial modified atmosphere packaged cheddar cheese, Food Control Available online 2006 17 (4) 286-292. 

Since the initial start-up of the furnace in 1995, the stack damper controlling the oxygen level had been little used, because it was very difficult to operate. Several complaints had been made to direct attention to this problem, but all to no avail. 

Other workers have demonstrated improved lung function (including arterial oxygen level increase [355]) and increased response to bronchodilators [356] after bromhexine. Some evidence of weak activity against tubercle bacillus has appeared [357] this could complicate culture control of anti-tubercular therapy. 

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