Oxygen concentration, automated

Hot feed Provide and maintain an automated inerting (increases system—oxygen concentration or pressure fire/explosion risk controlled with flammable. Eliminate leakage sources (ftimes/air) solvents). Use alternative solvents (nonflammable or less flammable) Reduce feed temperature and/or monitor temperature of feed and interlock with feed shutdown NFPA 69... 

Bioprocess Control An industrial fermenter is a fairly sophisticated device with control of temperature, aeration rate, and perhaps pH, concentration of dissolved oxygen, or some nutrient concentration. There has been a strong trend to automated data collection and analysis. Analog control is stiU very common, but when a computer is available for on-line data collec tion, it makes sense to use it for control as well. More elaborate measurements are performed with research bioreactors, but each new electrode or assay adds more work, additional costs, and potential headaches. Most of the functional relationships in biotechnology are nonlinear, but this may not hinder control when bioprocess operate over a narrow range of conditions. Furthermore, process control is far advanced beyond the days when the main tools for designing control systems were intended for linear systems. 

Biosensors. Sensors are required to adequately monitor bioreactor performance. Ideally, one would like to have online sensors to minimize the number of samples to be taken from the bioreactor and to automate the bioreactor process. Most bioreactors have autoclavable pH and dissolved oxygen (D.O.) electrodes as online sensors, and use offline detectors to measure other critical parameters such as glucose and glutamine concentration, cell density, and carbon dioxide partial pressure (pC02). An online fiber-optic-based pC02 sensor is commercially available and appears to be robust.37 Probes are also commercially available that determine viable cell density by measuring the capacitance of a cell suspension. Data from perfusion and batch cultures indicate that these probes are reasonably accurate at cell concentrations greater than 0.5 X 106 cells/mL.38,39... 

Oxygen enrichment increases the oxygen content of the process gas after the boiler if the bed temperature is kept constant by the furnace automation system by increasing the concentrate feed. However, if the cooling of the furnace is simultaneously improved, then the oxygen enrichment does not increase the oxygen content of the process gas, see Figure 10. 

For voltammetric study of the total antioxidant activity of the samples automated voltammetric analyzer Analyzer of TAA (Ltd. Polyant Tomsk, Russia) was used. As supporting electrolyte the 10 ml of phosphate buffer (pH = 6.76) with known initial concentration of molecular oxygen was used [7]. The electrochemical cell (V = 20 ml) was connected to the analyzer and consisted of a working MFE, a silver-silver chloride reference electrode with KCl saturated (Ag AgCl KCl J and a silver-silver chloride auxiliary electrode. The investigated samples (10-500 ml) were added in cell. 

The most impressive use of the substoicheiometric displacement technique is the automated isotope dilution method of Ruzicka and Lamm for the determination of Hg in biological materials. After oxygen flask destruction of the samples and preliminary manual separation, the Hg is automatically extracted from an aqueous solution by a substoicheiometric amount of zinc dithizonate and the activity of the extract measured. The method has been used in the 0.4—0.004 pg of Hg range. At the present time, when there is concern about the concentration of toxic elements in foodstuffs and the environment, an automated analysis system of this type could be of great value for large-scale routine monitoring of trace element levels. 

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