Straight-line approach

Jensen, R. H., and Davy, D. T. (1975). An investigation of muscle lines of action about the hip A centroid line approach vs the straight line approach, Journal of Biomechanics, 8 103-110. 

Base Line. Selecting a proper base line for integrating the area under the curve is essential for enthalpy determinations. In the absence of detailed information about overall error in different alternative modes, a simple straight-line approach is adequate. However, for partial area measurements in kinetics, a more accurate base line may be needed. The following texts may be consulted for further information on this topic Wendlandt (4), Brown (19), and Wimderhch (11). Many modern instruments have the ability to manipulate the hase line. In the case of irreversible transformations without any weight loss, a simple rerun of a sample (after the transformation), under the same conditions should give a suitable base line. All current computerized instruments can subtract one base line from another that is generated under identical experimental conditions. 

Occasionally the DR plot falls into two straight lines (cf. Fig. 4.20), and the question again arises as to the significance of the different values of the uptake at p°jp = 1, derived by extrapolation of the respective branches, ( te often, the DR plot displays an upward turn as saturation pressure is approached (Fig. 4.18 and 4.21), a feature which can readily be understood in terms of multilayer adsorption and capillary condensation in mesopores. 

Because of the hyperbolic shape of versus [S] plots, Vmax only be determined from an extrapolation of the asymptotic approach of v to some limiting value as [S] increases indefinitely (Figure 14.7) and is derived from that value of [S] giving v= V(nax/2. However, several rearrangements of the Michaelis-Menten equation transform it into a straight-line equation. The best known of these is the Lineweaver-Burk double-reciprocal plot ... 

Following Reference 19, plot this on the appropriate curve (good up to altitudes of 3,000 ft) for RaV/L vs. L /Ga for the proper wet bulb, range and at the intersection of the straight line plot with the approach value selected or needed, read the L /Ga required to meet the performance conditions. 

Asymptote A straight line connected with a curve such that as a point moves an infinite distance along the curve from the point to the line approaches zero and the slope of the curve at the point approaches the slope of the line. 

From plots of In g(a) against In T with n = 0, 1 and 2, the plot which gives the best straight line identifies the value of n and from the slope Um and hence E is calculated. (This approach can also be regarded as a reference temperature method , see also Sect. 6.2.4). 

This equation can be fit to experimental data in several ways. The model exhibits a sharp first appearance time, tf st = rpt, which corresponds to the fastest material moving through the system. The mean residence time is found using Equation (15.13), and Xp = tf,rsi/1 is found by observing the time when the experimental washout function first drops below 1.0. It can also be fit from the slope of a plot of In W versus t. This should give a straight line (for t > tfirst) with slope = 1/(F— tfirst)- Another approach is to calculate the dimen-... 

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