Glycerol concentration

The concentration of distilled glycerol is easily determined from its specific gravity (15) by the pycnometer method (16) with a precision of 0.02%. Deterrnination of the refractive index also is employed (but not as widely) to measure glycerol concentration to 0.1% (17). 

Glycerol concentration (Weight %) Reaction Rate constant (M3/kg-mole sec.)... 

Leibo, S.P. (1976). Freezing damage of bovine erythrocytes Simulation using glycerol concentration changes at subzero temperatures. Cryobiol. 13,587-598. 

The non equilibrium status can be seen during a slow cooling of a water-glycerine solution Starting with a 20 % glycerol solution pure ice crystals will first be formed until at -46.5 °C when the glycerol concentration has reached 66.7 %. At this temperature, the eutectic should solidify. Howevere it is possible to reduce the temperature to -58 °C with a glycerol concentration of 73 %. A further decrease of the temperature does not crystallize... 

Liquid absorbents. If the partial pressure of the water in the gas is greater than the equilibrium partial pressure at the surface of a liquid, condensation will take place as a result of contact between the gas and liquid. Thus, water vapour is frequently removed from a gas by bringing it into contact with concentrated sulphuric acid, phosphoric acid, or glycerol. Concentrated solutions of salts, such as calcium chloride, are also effective. The process may be carried out either in a packed column or in a spray chamber. Regeneration of the liquid is an essential part of the process, and this is usually effected by evaporation. 

Under aerobic conditions, mixed cultures isolated from pond water and sediment degraded diuron (10 pg/mL) to 3-(3-chlorophenyl)-l,l-dimethylurea (CPDU), 3,4-dichloroaniline, 3 (3,4-dichlorophenyl)-l-methylurea, carbon dioxide, and a monodemethylated product. The extent of biodegradation varied with time, glycerol concentration, and microbial population. The degradation half-life was <70 d at 30 °C (Ellis and Camper, 1982). 

The data show that there is an effect of the initial glycerol concentration on the conversion into dihydrogen. A concentration of 0.1 mol of glycerol seems to represent the best condition for its conversion. 

Cardoso Rde C., A. R. Silva, D. C. Uchoa, and L. D. da Silva. Cryopreser-vation of canine semen using a coconut water extender with egg yolk and three different glycerol concentrations. Theriogenology 2003 59(3-4) 743-751. 

Prepare a standard curve using the glycerol concentrations and the radioactivity on the filter paper. 

Calculate the output glycerol concentration (/iM) after the microorganisms have increased their biomass to a steady-state level. Also calculate what the steady-state biomass level is (cells m-3). Assume you have a tank with V= 10 m3, a waste water flow Q = 50 m3 d l, and a microbial inoculum with growth properties like those shown in Table 17.6 for the Aerobacter sp., a die off coefficient b of 0.1 d-1, and a glycerol-to-biomass yield of 1014 cells -mol-1. 

Now you can solve for the resultant steady-state glycerol concentration using the Monod growth relation, Eq. 17-61, and values of = 28.8 d1 and KiM = 120 /iM from Table 17.6 ... 

Note With 5% glycerol, the stock LacI solution is viscous. It is desirable to control the final glycerol concentration to be less than 0.5% or, in the other words, to concentrate the stock LacI solution to be at least 10 times more than the experimental LacI concentration. We concentrate LacI to 30 f iM (OD280 = 3) or above. Introduction of 0.5% glycerol increases the viscosity of the solution by slightly less than 1% and gives a negligible increase in the anisotropy of <1%. 

Fig. 5. Effect of glycerol concentration on succinic acid production, fumaric acid consumption, and cell growth. The culture conditions were as follows 50-mL vial (40 mL of medium) 15 g/L of yeast extract 5 g/L of K2HP04 initial pH of 7.0.

Fluhr et al. presented similar results.21 Four different vehicles (water in oil and oil in water emulsion) and two different glycerol concentrations (5 and 10%) were tested. 10% glycerol was more efficient than 5%, independent of the basic formulation. However, the o/w emulsion seemed to be more effective than the w/o formulation.21... 

Figure 7.43. Effects of glycerol concentration and temperature on activities of A4-LDH from an Antarctic notothenioid (Parachaenichthys charcoti) and a warm-temperate goby fish (Gillichthys mirabilis). Inset the effects of glycerol concentration on the two orthologs at physiological temperatures of the species, 0°C for P. charcoti and 20°C for G. mirabilis. (Modified after Fields et al., 2001.)...

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