Reduced volume, 1.8

Bunsen (1855), to whom we owe the first accurate measurements of the solubilities of gases in liquids, expressed his results in terms of an absorption coefficient /3, which he defined as the volume of gas, reduced to 0° C. and 76 cm., dissolved by 1 c.c. of the liquid at any given temperature under the same pressure. If v c.c. of gas are dissolved by Y c.c. of liquid at a temperature 6 and pressure p cm., the volume reduced to normal conditions is... 

Figure 2.1 Decreasing the external pressure by dp causes the piston to move a distance dx. This increase in volume reduces the internal pressure by dp and re-establishes mechanical equilibrium. The process produces pressure-volume work.

In the presence of polyethylene oxide MW 300,000 at a concentration of 0.025 g liter , variations in pH and ionic strength have no effect on elution volumes and a single calibration curve is obtained as shown in Figure 4 and Table II. This behavior presumably also results from modification of the glass surface by the polyethylene oxide surfactant, but in this case charge effects appear to be completely suppressed and the effective pore diameter and volume reduced. Such an interpretation is also in accord with the fact that the elution voliomes are lower with polyethylene oxide than with Tergitol, since Tergitol is a much smaller molecule than the polyethylene oxide. 

The effect of dissolved hydrophilic electrolytes on the interaction between organic solutes and water can be described by the salting-in and salting-out effects. Dissolved electrolytes usually increase the internal pressure in water, through a volume-reducing process that... 

Because scavenger columns are located upstream of the injection valve, they do not add to the dispersion of the chromatogram, and their size is not critical in this respect. Guard columns, on the other hand, do cause a slight loss of efficiency, and so need to have a relatively small volume. Reducing the volume, of course, reduces the life of the guard column. 

Van Eldere J, Robben J, Caenepeel PH, Eys-sen H Influence of a cecal volume-reducing intestinal microflora on the excretion and en-tero-hepatic circulation of steroids and bile acids. J Steroid Biochem 1988 29 33-39. 

Sample concentration-. Higher sample concentrations or larger sample volumes reduce integration errors and thus increase precision. ... 

As the distribution ratio between phases 1 and 3 is the product of those in the two pairs of fluids, the potential effectiveness of the liquid membrane process is considerably greater than that of conventional solvent extraction. Thus the liquid membrane process is particularly suitable for the treatment of dilute feeds. In addition, if the liquid membrane is an organic phase, its small volume reduces the solvent duty considerably. 

Anhydrous Copolymerization of NIPAAM and N-Acryloxysuccinimide (NASI). In a modification of the procedure of Poliak et al., (4), NIPAAM (5 g, 44 mmol), NASI (0.372 g, 2.2 mmol) and 2,2 azobisisobutyronitrile (AIBN, 0.021 g, 0.13 mmol) were dissolved in 50 ml of dry tetrahydrofuran. The magnetically stirred solution was degassed, heated to 50 C for 24 hours under positive nitrogen pressure, and allowed to cool. The reaction mixture was filtered (0.45 i teflon filter) and the filtrate volume reduced by half. Ether was added with mixing to precipitate the copolymer. 

The first toxic peak(s) from the Bio-gel P-2 run (volume reduced to 1 ml) is passed through a preparative mini column (Sep-pak 18 to separate the toxin(s) from yellowish pigments. The eluant is then subjected to HPLC using a semipreparative column (CN bonded phase 9.4 mm x 25 cm). Fig. 3 illustrates the presence of neosaxitoxin (second last peak) and saxitoxin (last peak). A total of 150 mu (mouse units) was loaded. The profile in Fig. 4 shows only neosaxitoxin (500 mu) is present because only a portion of the first toxic peak(s) from the P-2 run was injected. The bottom profile is that of a standard neosaxitoxin (200 mu). 

Leaf samples for myrlstlcin analysis were weighed Into 10-ml screw-top vials. Myristicln was extracted In ca. 4 ml hexane for 24 h. Fifteen micrograms of octadecane was added as an internal standard. The hexane was decanted and the volume reduced to ca. 0.3 ml. Myristicln was quantified by GLC-FID (3% OV-17, 2 m x 4 mm ID, operated isothermally at 125° C) with a Varlan 2700 instrument and a Hewlett-Packard 3390A integrator. 

Although of sufficient purity for the next step, the sulfonimine can be further purified by recrystallization. In a 2-L Erlenmeyer flask containing 150 mL of ethyl acetate is dissolved, with warming, 212 g of the crude sulfonimine. After the mixture is cooled to room temperature, about 400 nl. of pentane is added and the solution is allowed to stand at room temperature for 2-3 hr. The colorless crystalline product is collected by filtration, washed with 100 mL of pentane and air dried to give 191.5 g (78%), mp 78-80°C. The washings and filtrate are combined and the volume reduced by about one third using a rotary evaporator. A second crop of crystals, 20.2 g (8%), mp 75-79°C, was obtained on standing for several hours. 

Preliminary chemical modeling by the developer found that tank wastes from fuel processing operations at U.S. nuclear weapons plants could be volume reduced by over 75%, at a cost of cents per gallon. These wastes are made up mostly of sodium nitrate in either a high pH or a 2 molar nitric acid solution. Radionuclides in these wastes only make up a few grams per liter, and current plans call for vitrification of these wastes (D130916, p. 10). 

Diazinon has a finite vapor pressure (see Chapter 3) and thus will be present in the air. A method for diazinon in air has been reported that is based on the use of polyurethane foam (PUF) to adsorb the pesticide from the air as the air is pulled through the PUF (Hsu et al. 1988). The PUF is then Soxhlet-extracted and the extract volume reduced prior to capillary GC/MS analysis. An LOD of 55 ng/m3 (5.5 m3 sample) and recovery of 73% were reported. Another study was described in which the diazinon levels in indoor air were monitored following periodic application of the pesticide for insect control (Williams et al. 1987). In this method, air is pulled through a commercially available adsorbent tube to concentrate diazinon. The tube is then extracted with acetone prior to GC/NPD analysis. No data were provided for the LOD, but recoveries in excess of 90% were reported at the 0.1 and 1 pg/m3 levels. This paper also indicated that diazinon can be converted to diazoxon by ozone and NOx in the air during the sampling process. 

These ingredients produce no noteworthy physical property improvements in rubber vulcanizates. They merely act as diluents and are chiefly used to increase volume, reduce cost and for... 

The sign of the volume of activation, Av, determines whether the rate constant, k, increases or decreases with the pressure. The value of Av is positive when the volume of the activated complex is larger than the volume of the initial reactants. Thus the rate constant, k, decreases when the pressure is increased. When the volume reduces in the transition state, Av 1 is negative and k will increase with increasing pressure (Table 3.2-2). 

In order to investigate the influence of the pressure, polymerization tests were run at pressures of 120 - 190 MPa. As can be seen from Fig. 9.5-6, the rate of polymerization increases from (0.58 to 1.3) 10 3 mol ethylene/(l s). When r, r is plotted on a logarithmic scale versus the pressure, a value of activation volume of -32.5 ml/mol can be evaluated from the slope of the resulting straight line. The negative value is characteristic for polymerization reactions because the volume reduces in the transition state (see Chapter 3.2). 

A DNA hybridisation assay with enzymatic electrochemical detection is carried out on a 100 nm sputtered gold thin film that allows working with small volumes. Reducing the cell volume has several advantages [49]. The first one is the decrease in the diffusion distances required for analytes to reach their surface-bound receptor partners. Moreover, in the case of enzymatic detection, the product dilution, a critical factor in achieving low detection limits, diminishes. A simple, cheap and easy-to-handle homemade device that permits to perform simultaneous hybridisation procedures and sequential detection of more that 20 assay sites is presented. 

The best explanation of the good results for peptide syntheses in ice-water mixtures are based on the freeze-concentration-model, which just provides for a volume-reducing function for the ice while the liquid aqueous part is still the only relevant phase for the reaction. All observed enhancements of reaction rate would then have to be attributed to an increase in effective concentration. H-NMR relaxation time measurements have been used to determine the amount of unfrozen water in partially frozen systems, thus quantifying the extent of the freeze-concentration effect (Ullmann, 1997). Comparative studies in ice and at room temperature verify the importance of freeze-concentration which, however, is not sufficient for a complete understanding of the observed effects. 

Dry vermouths usually have a higher alcohol content, lower sugar content, and are lighter color than sweet vermouths. In addition, they are usually more bitter in flavor. In a typical French dry vermouth, the alcohol content is 18% by volume, reducing sugar 4%, total acidity (as tartaric acid) 0.65%, and volatile acidity (as acetic acid) 0.053% (Joslyn and Amerine, 1964). 

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