Extinction concentration curves

Fig 10. Extinction-concentration curves for different times of flocculation (Agl sol with KNO3). The low extinction at high concentrations corresponds to a loose floccule. 

Figure 26.2 Ignitions (solid curves), extinctions (dashed curves), HB (open circles), and HB temperatures with the heat of all reactions set to zero (open squares) as functions of inlet H2 concentration in air at 4 atm. The strain rate is 200 s ... 

IUPAC.-Working Party on "The Relationship of Performance Characteristics to Basic Parameters of Polymers . This sample has been investigated in transdecalin at 160° C. Fig. 3.8 shows the extinction angle curves obtained for the three indicated concentrations as functions of A linear extrapolation at various /Sy.urvalues was possible and led... 

Solutions of various concentrations of dioxime(5) and Nitrooxime(8) in O.IM NaOH in 15% aqueous ethanol were prepared. Ultraviolet spectra were determined for each of the solutions and absorbance vs. concentration curves were established for each compound to determine their respective molar extinction coefficients. The absorbances of anions(8 and 5) were... 

Figures 11.1 and 11.2 illustrate the concentration and temperature profiles in a hydrogen diffusion flame and the typical S-curve denoting temperature dependencies on the Damkohler number that describe the simplified diffusion flame. Two characteristic points are seen on the S-curve. The lower characteristic point Ti is a firing point, the upper one Tad is the point of extinction. The curve itself is often called a fundamental curve of extinction because it is used for predicting the extinction level of a diffusion flame.

Fig. 9. Extinction-time curves for a silver iodide sol (0.4 m mol litre) flocculated with KNO3. The concentration of KNO3 in m mol/litre is indicated beside the curves.

Measure the intensity of molar extinction at 302 nm against that of a blank soluhon prepared by diluting 15 mL of methanolic KOH to 25 mL with methanol. Determine the carbon disulhde content from a calibration curve obtained by plothng the carbon disulhde concentrations of different standard solutions on the abscissa versus the absorbance on the ordinate. 

One cm3 of the reactant/product/catalyst mixture was sampled periodically during the reaction for the transmission infrared analysis (Nicolet Magna 550 Series II infrared spectrometer with a MCT detector). The concentrations of reactants and products were obtained by multiplying integrated absorbance of each species by its molar extinction coefficient. The molar extinction coefficient was determined from the slope of a calibration curve, a plot of the peak area versus the number of moles of the reagent in the IR cell. The reaction on each catalyst was repeated and the relative error for the carbamate yield measured by IR is within 5%. 

Halohydrin dehalogenase activity was determined by monitoring halide liberation at 30 °C in tris-S04 buffer (50 mM, pH 8.0) containing 5 mM 1,3-dichloropropanol or 1,3-dibromopropanol as the substrate. All buffers used for activity assay were prepared with bidest water. From the incubation mixture, 0.5 ml samples were taken and mixed with 1.6 ml of H2O, 0.2 ml or halide reagent 1 and 0.2 ml of halide reagent II. Absorbances were read at 460 nm. A calibration curve of 0-1 mM of chloride or bromide was used to calculate the concentration of halide. The extinctions at 460 nm should be below 0.4 (for chloride) or 0.8 (for bromide). 

The values of kinetic parameters (pre-exponential factors k0j and activation energies Ej of rate constants k and inhibition constant Kg) can for a particular catalyst be determined by weighted least squares method, Eq. (35), from the light-off or complete ignition-extinction curves measured in experiments with slowly varying one inlet gas variable—temperature or concentration of one component (cf., e.g., Ansell et al., 1996 Dubien et al., 1997 Dvorak et al., 1994 Kryl et al, 2005 Koci et al., 2004c, 2007b Pinkas et al., 1995). 

Fig. 3.8. Extinction angles % vs. reduced shear rate for solutions of a high density polyethylene fraction (Dow Chem. Corp.) in transdecalin at 160° C (75). The concentrations are indicated near the curves in g/100 cm. Open and closed symbols indicate repeat measurements. The dotted line gives the extinction angle vs. at zero concentration, as obtained by linear extrapolation at several...

Fig. 5.2. Extinction angle x vs. shear rate q for solutions of a polystyrene fraction (M = 3.3 X 10°) in dioxane according to Frisman and Tsvetkov (138). The numerals at the curves indicate concentrations in g/100 cm3...

The Parr turbidimeter is an extinction type instrument, which consists of a cylinder to contain the turbid suspension, a lamp filament of fixed intensity at the base, and an adjustable plunger through which visual observation is made. Measurement is made of the depth of turbid medium necessary to extinguish the image of the lamp filament Standard suspensions are used to prepare a calibration curve, which is a plot of depdi vj. concentration. 

For an adiabatic reaction we found two kinds of features in the curves of the dependence of the percentage consumption on the chemical reaction time. In stable regimes an increase in the time facilitates an increase in the percentage of reacted substance and an increase in the temperature. With an increase in the residence time, for sufficient initial concentration, self-ignition of the mixture is possible in contrast, extinction occurs only when the reaction time is reduced. 

A colorimetric assay involves the oxidative cleavage of proanthocyanidins with ferrous sulfate. To 0.5 mL of aqueous plant extract is added a 5-mL portion of an acidic solution of ferrous sulfate (77 mg of FeS04.7H20 dissolved in 500 mL of 2 3 HCl/ -butanol). The tubes are loosely covered and placed in a water bath at 95°C for 15 min. The absorbance is read at 530 nm. The concentration of proanthocyanidins is expressed as cyanidin equivalents (used for the standard curve). The molecular extinction coefficient emoi that can be used to convert the absorbance values to a concentration is equal to 34700 L mol cm 1. 

The concentration of arsenic can be determined at 600 nm because the Sb-Ag DDTC complex does not absorb light of this wavelength. The molar absorptivity of the antimony complex with Ag DDTC reaches its maximum value at 504 nm, but there is also appreciable light absorbance from the As-Ag DDTC complex at this wavelength. The antimony concentration can be calculated from the total extinction value measured at 504 nm by subtracting the extinction value (at 504 nm) that corresponds to the previously determined arsenic concentration. It is clear that calibration curves of arsenic at 504 and 600 nm and of antimony at 504 nm are needed to perform the calculation. 

In Figure 16.34b there is a typical curve that describes Eq. (16.24). At high concentrations, even a complete extinction of the fluorescence sign can be observed. A similar behavior can occur when the sample contains chromospheres that compete for the absorption of light excitation. 

Figure 3. Spectrum of the extinction coefficient (open circles) calculated from the experimental spectra (solid curves) of C 60FWS at concentration 400 iM/l recorded at right angle for different distance of the excited laser beam from the side surface of a quartz cuvette.

The structure of the paper itself affects the behavior with respect to Beer s law which establishes a relation between extinction E and concentration C of transparent solutions, according to the expression E = kC. When extinction measured on paper is plotted against concentration, not a linear but a hyperbolic curve is obtained (CIO, Cll). The cause of the error is the sievelike structure of the paper, since only the threads are covered with stained proteins while the meshes remain completely permeable to light (Fig. 34). This light falling directly on the photosensitive layer of the cell gives, on the microscopic scale, the same error as found for uneven distribution of stained spots on a clear... 

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