Volumetric growth

Microbial-enhanced oil recovery involves injection of carefully chosen microbes. Subsequent injection of a nutrient is sometimes employed to promote bacterial growth. Molasses is the nutrient of choice owing to its low (ca 100/t) cost. The main nutrient source for the microbes is often the cmde oil in the reservoir. A rapidly growing microbe population can reduce the permeabiHty of thief zones improving volumetric sweep efficiency. Microbes, particularly species of Clostridium and Bacillus, have also been used to produce surfactants, alcohols, solvents, and gases in situ (270). These chemicals improve waterflood oil displacement efficiency (see also Bioremediation (Supplement)). 

In conclusion, it should be pointed out that recently [51], a considerable growth of specific fluid volumetric flow rates was discovered near the saturation pressure on filtra tion of the solution of C02 in normal heptane and gas-liquid fossil carbohydrates (oils). A possible explanation of this effect can be found in the above theoretical discussion. Finally, going back to M. Amon and C. D. Denson s work [33], which was discussed at the end of Sect. 4, let us admit that their thesis No. 4 (melt properties as regards thermoplastic itself do not depend on gas concentration) is quite correct and in good correlation with experimental results [21]. 

Equations 11 and 12 are only valid if the volumetric growth rate of particles is the same in both reactors a condition which would not hold true if the conversion were high or if the temperatures differ. Graphs of these size distributions are shown in Figure 3. They are all broader than the distributions one would expect in latex produced by batch reaction. The particle size distributions shown in Figure 3 are based on the assumption that steady-state particle generation can be achieved in the CSTR systems. Consequences of transients or limit-cycle behavior will be discussed later in this paper. 

Continuous Stirred Tanks with Biomass Recycle. When the desired product is excreted, closing the system with respect to biomass offers a substantial reduction in the cost of nutrients. The idea is to force the cells into a sustained stationary or maintenance period where there is relatively little substrate used to grow biomass and where production of the desired product is maximized. One approach is to withhold some key nutrient so that cell growth is restricted, but to supply a carbon source and other components needed for the desired product. It is sometimes possible to maintain this state for weeks or months and to achieve high-volumetric productivities. There will be spontaneous cell loss (i.e., kd > 0), and true steady-state operation requires continuous purging and makeup. The purge can be achieved by incomplete separation and recycle... 

Smith T.D., Siegel M.I., Burrows A.M., Mooney M.P., et al. (1999). Histological changes in the fetal human vomeronasal epithelium during volumetric growth of the vomeronasal organ. In Advances in Chemical Signals in Vertebrates (Johnston R.E., Miiller-Schwarze D. and Sorenson P., eds.). Plenum, New York, pp. 583-592. 

Two continuous stirred-tank fermenters are arranged in series such that the effluent of one forms the feed stream of the other. The first fermenter has a working volume of 100 1 and the other has a working volume of 50 1. The volumetric flowrate through the fermenters is 18 h-1 and the substrate concentration in the fresh feed is 5 g/1. If the microbial growth follows Monod kinetics with //, = 0.25 h-1, Ks = 0.12 g/1, and the yield coefficient is 0.42, calculate the substrate and biomass concentrations in the effluent from the second vessel. What would happen if the flow were from the 50 1 fermenter to the 100 1 fermenter ... 

Figure 8.24 Correlation of volumetric fire growth for a dwelling with similar compartment characteristics [24]...

Now Volumetric rate at which solids are entering zone Cf = Total volumetric growth rate of zone ... 

An MSMPR crystalliser operates with a steady nucleation rate of n = 1013/m4, a growth rate, Gd = 10-8 m/s and a mixed-product removal rate, based on clear liquor of 0.00017 m3/s. The volume of the vessel, again based on clear liquor, is 4 m3, the crystal density is 2660 kg/m3 and the volumetric shape factor is 0.7. Determine ... 

For premixed fuel-air systems, results are reported in various terms that can be related to a critical equivalence ratio at which the onset of some yellow flame luminosity is observed. Premixed combustion studies have been performed primarily with Bunsen-type flames [52, 53], flat flames [54], and stirred reactors [55, 56], The earliest work [57, 58] on diffusion flames dealt mainly with axisymmetric coflow (coannular) systems in which the smoke height or the volumetric or mass flow rate of the fuel at this height was used as the correlating parameter. The smoke height is considered to be a measure of the fuel s particulate formation and growth rates but is controlled by the soot particle bumup. The specific references to this early work and that mentioned in subsequent paragraphs can be found in Ref. [50],... 

The test procedure can be performed by pumping HPLC grade water at a specified flow rate under a controlled back-pressure, using a commercial back-pressure device connected in-line just after the pump. A f 000 psi back-pressure device is recommended. It is also advised that about f % MeOH be added to the water in order to minimize biological growth. While timing the process with a calibrated stop watch, the pump effluent should then be collected in a volumetric flask. From this, one can calculate the actual solvent flow at each flow rate. 

Anaerobic Filter. An anaerobic filter consists of packed support media that traps biomass as well as facilitates attached growth of biomass as a biofilm (Fig. 8). Such a reactor configuration helps in the retention of suspended biomass as well as gas-liquid-solid separation. The flow of liquid can be upward or downward, and treatment occurs due to attached and suspended biomass. Treated effluent is collected at the bottom or top of the reactor for discharge and recycling. Gas produced in the media is collected underneath the bioreactor cover and transported for storage or use. Volumetric loading rates vary from 5 to 20 kg COD/m day with HRT values of 0.5-4 days. 

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