Experiment error

Results are shown in Table 3. In all runs methanol has been detected as a sole product and its amount within the experiment error correlates with that of CH4 consumed. It is of interest that methane reaction with a-oxygen ... 

Figure 3 The shock Hugoniot of PETN as calculated with exp-6 (solid line) and the JCZS library (dotted line) vs. experiment (error bars).

Active site burst titrations of the Zn(II) enzyme and the Co(II) enzyme at acidic pH and low substrate concentrations [(70-1) X 10 6 M] indicated one active site (96, 98, 99, 110, 135), while similar experiments (186) at high substrate concentration (2 X 10-3 M) yielded a value of 2.7 sites per dimer. In the latter experiment, error in the number of active sites might arise from the fact that the results were obtained by extrapolation from steady state measurements without direct observa-ion of the pre-steady-state phase. In the low substrate experiments, the pre-steady-state phase was observed directly. A burst was obtained at intermediate substrate concentrations (4 X 10"4 M), but the size was not reported (137). 

The rms deviation of this COSMO-RS drug-solubility prediction is 0.66 log-units on the training set. Considering the fact that the available data sets for aqueous drug solubility typically have an intrinsic experimented error of about 0.5 log-units (rms), this... 

When doing experimental research, one should distinguish several kinds of errors measurement error, trial error and experiment error. These errors will be analyzed in detail in a subsequent chapter. 

Variance homogeneity facilitates calculation or estimate of experiment variance-reproducibility variance (oyj, which characterizes the total experiment error. Knowing (Sy) is necessary for regression analysis. Calculation of reproducibility variance depends on conditions for replicating trials. In the case of variance homogeneity of replicated trials and the same number of replications, reproducibility variance is determined thus ... 

In Example 2.27, FUFE 21, experiment error Sy2 has been determined from eight trials, each of which has been replicated twice (r 2). Experimental results are given in Table 2.180. 

Sy-is error mean for trial replications, and it is connected to experiment error by relation (2.137). 

In the introduction, we have already classified the optimization problems as deterministic and stochastic. It is evident that deterministic problems are based on functional models or models that disregard experiment error. Problems where one cannot neglect experiment error are stochastic ones and, as established, they are the subject of this book. Besides, optimization problems are by the number of factors divided into one-dimensional and more-dimensional. The Optimization problem grows with dimension. The problem becomes even more complicated if optimization is not done by one but by more responses simultaneously-multiple response processes. 

Movement to optimum along the gradient is in steps from the starting point to optimum. Due to the necessary number of steps for reaching optimum, we differentiate several gradient methods that are in use nowadays. Efficiency of gradient methods depends on the complexity of the studied response space, on magnitude of the selected step, on size of experiment error and on other factors. 

It should be emphasised that in following the rate of dissolution of solid A in liquid B by the mass loss of a solid specimen of substance A, measured by weighing the specimen before and after the experiment, errors may well arise, due to the formation of a chemical compound layer at the solid-liquid interface. On the one hand, dissolution of the solid phase A in the liquid phase B reduces the mass of the solid specimen. On the other, however, formation of the ApBq compound layer adhering to the surface of the solid specimen increases its mass (at k0 > b). Hence, the experimentally determined change in the mass of the solid specimen is a consequence of the two simultaneously occurring processes, namely, growth and dissolution of the ApBq layer. 

Curves of peroxide decomposition coinside within the limits of experiment error, which indicates the nonchanging of constant of BzjOj decomposition rate... 

With careful experimented design, inverse gas chromatography can be a viable method for the determination of the polymer-polymer interaction coefficient B23. The variation of apparent B23 values with the probe is shown to be related to the chemical nature of the probe and not due solely to experimented error. A method is presented to allow the estimation of the true B23 value. Experiments were performed on a 50/50 blend of poly(epichloro-hydrin)/poly( -caprolactone) at several teqperatures. Polymer and blend solubility parameters were determined. 

Fig. 3. Effects of various concentrations of gpl20 on IL-4, IL-13 and IFN-7 secretion from human basophils obtained from normal donors. Purified basophils were incubated with gpl20 for 4h at 37°C (IL-4) or 18h at 37°C (IL-13 and IFN-y). Each point represents the mean SEM obtained from four experiments. Error bars are not shown when graphically too small. (Reproduced with permission from Marone et al. [16].)... 

Fig. 6.11 D uration of efficacy pig study. After a single intracoronary injection of 1v.p. AdSFGF-4, pacing-induced left ventricular functional deficit was reversed at 2 weeks after gene injection, and maintained for up to 12 weeks. Numbers in columns indicate mean number of experiments error bars denote 1 SD.

Fig. 10. Effect of immobilized enzyme concentration on initial rate of heparin degradation at T = 37°C, pH 7.4, and agitation speed 140 rpm. Ratio of volume of fluid phase to volume of beads, 200 1. Each point was the mean of four independent experiments. Error bars are the size of points. Line is the theoretical prediction for case of no internal diffusion (Ch = 0.1 mg/mL, Ch = 0.2 mg/mL) [from Bernstein et al. (50)].

Figure 3. Adsorption of fibrinogen on glass as a function of time at various hematocrits. Conditions buffer—PBS, pH 7.35 fibrinogen concentration—1.0 mg/mL in free volume and shear rate at the surface—540 s Values are the average of at least three experiments error limits are standard deviations.

Figure 4. Relationship between reaction pH and yield of oligo(y-ethyl-L-oligoglutamate.. Rea ctions were conducted using an automatedpH-stat, 0.9M phosphate buffer, 0,5ML-glutamic acid diethyl ester hydrochloride, 8 mg/mL catalyst, at 40 for 20 min. Values reported are the mean of at least duplicate experiments error bars define the maximum and minimum values obtained.

It is claimed that much less experimental work is involved to achieve accurate results than would be by conventional methods this is due to the fact that between experiments errors are always greater than within experiment errors. On the other hand, it is imperative (1,2) that, before the method is applied, the order of the reaction should be well established and the isothermal rate constant should have been ascertained to be constant over the whole range of reaction considered. 

---