Reproducibility conditions

If the inspection equipment can be run under stable and reproducable conditions due to the QAP the basis for using a camera system for flaw detection is given.The camera system consists of CCD-cameras and a pattern recognition software. Up to four CCD-cameras can be served by one PC. One shot of the part may be copied up to 16 times in the computer and this theoretically enables the crack determination with 16 different parameter sets. 

The column is enclosed in a thermostatically controlled oven so that its temperature is held constant to within 0.5 °C, thus ensuring reproducible conditions. The operating temperature may range from ambient to over 400 °C and for isothermal operation is kept constant during the separation process. 

Plant cell suspensions offer the potential to produce valuable phytochemicals, traditionally extracted from the naturally grown whole plant, under controlled and reproducible conditions. To date, commercial processes involving these systems have been limited to just a handful of applications, including the much-cited shikonin [1] and ginseng [2,3]. 

The precision of recovery is determined under repeatability and reproducibility conditions. The more important between-laboratory reproducibility is calculated as relative standard deviation (RSDr) and compared with the RSDr, which is estimated from the Horwitz equation using the same analyte concentration. For good methods this ratio should be about 1, but a method will usually be accepted if the ratio is not larger than 2. 

Stirred suspensions of droplets have proven to be a popular approach for studying the kinetics of liquid-liquid reactions [54-57]. The basic principle is that one liquid phase takes the form of droplets in the other phase when two immiscible liquids are dispersed. The droplet size can be controlled by changing the agitator speed. For droplets with a diameter < 0.15 cm the inside of the drop is essentially stagnant [54], so that mass transfer to the inside surface of the droplet occurs only by diffusion. In many cases, this technique can lack the necessary control over both the interfacial area and the transport step for determination of fundamental interfacial processes [3], but is still of some value as it reproduces conditions in industrial reactors. 

The conductivity of membranes that do not contain dissolved ionophores or lipophilic ions is often affected by cracking and impurities. The value for a completely compact membrane under reproducible conditions excluding these effects varies from 10-8 to 10 10 Q 1 cm-2. The conductivity of these simple unmodified membranes is probably statistical in nature (as a result of thermal motion), due to stochastically formed pores filled with water for an instant and thus accessible for the electrolytes in the solution with which the membrane is in contact. Various active (natural or synthetic) substances... 

Closeness of the agreement between the results of measurements of the same measurand carried out under changed conditions of measurement (Precision under reproducibility conditions). Reproducibility may be expressed quantitatively in terms of suitable dispersion characteristics. 

Experimental standard deviation obtained from a series of measurements under reproducibility conditions. 

A confidence interval representing the maximum permitted difference between two single test results under reproducibility conditions ... 

Precision The closeness of agreement between independent test results obtained under stipulated conditions. NOTES (i) Precision depends only on the distribution of random errors and does not relate to the true value or the specified value, (ii) The measure of precision is usually expressed in terms of imprecision and computed as a standard deviation of the test results. Less precision is reflected by a larger standard deviation, (iii) Independent test results means results obtained in a manner not influenced by any previous results on the same or similar test object, (iv) Quantitative measures of precision depend critically on the stipulated conditions. Repeatability and reproducibility conditions are particular sets of extreme stipulated conditions. 

Reproducibility Precision under reproducibility conditions, i.e. conditions where independent test results are obtained with the same method on identical test items in different laboratories by different operators using different equipment. 

Reproducibility limit The value less than or equal to which the absolute difference between two test results obtained under reproducibility conditions may be expected to be with a probability of 95%. 

To ensure operation under reproducible conditions, the column is enclosed in a thermostatically controlled oven whose temperature can be held constant to within 0.1°C. Operating temperatures range from ambient to over 400°C and may remain constant during a separation - isothermal operation - or automatically increased at a predetermined rate to speed the elution process - temperature programming (p. 106). The latter is a form of gradient elution. Rapid temperature equili-... 

When the test programme spans long times, the situation is more akin to reproducibility conditions than to repeatability, even although the measurements are made in the same laboratory. The increase in uncertainty can be illustrated by comparing the repeatability and reproducibility figures given in precision statements. 

A potential alternative method to chemical synthesis of superconducting materials is offered by electrochemistry, particularly in view of the possibility that one has to achieve reproducible conditions. 

A method is proposed to assess the Odom Potential of slurries and sludges by sampling in the liquid phase, followed by extraction of odorous components under reproducible conditions. The approach has inherent advantages in providing speedy and less costly information for the prediction of odour nuisance, scheduling land disposal, and for comparing methods of sludge treatment and stabilisation. 

Today, particle accelerators and computers are as much apart of astronomy as telescopes intent on spying out the visible and the invisible. In their accelerators, high-energy physicists are able to reproduce conditions in the Big Bang and in the stellar core. Then, taking over from them, numerical simulation by computer can write the story of matter through its various cycles of concentration, nucleosynthesis and dispersion. 

Repeatability conditions and reproducibility conditions are extreme cases... 

The repeatability and reproducibility limits express the maximum acceptable difference between two consecutive measurements, which are done under repeatability or reproducibility conditions respectively. The factor 2 results from the error propagation of a difference. Each of the two values has a standard deviation of a, so we get r =t - +cr = V2(t = V2 a... 

There are different standard deviations depending on the measurements conditions repeatability conditions, between-batch and interlaboratory reproducibility conditions. 

The aim of sample preparation is that the components of interest should be extracted from complex matrices with the least time and energy consumption but with highest efficiency and reproducibility. Conditions should be mild enough to avoid oxidation, thermal degradation, and other chemical and biochemical changes. Some procedures — CE, for example — necessitate more rigorous sample pretreatment than others. On the other hand, TLC requires an absolute minimum of sample preparation. 

Many, and quite differentiated, drug effects can be shown and quantified in healthy volunteers under standardized and thus reproducible conditions. The information gathered in these experiments can be usefully applied in a number of theoretical and practical contexts. This chapter has not dealt with some of the herbal medicines, and we also omitted discussion of older studies with simultaneous or consecutive administration of more than one drug, e.g. the so-called scopolamine model to study cognition enhancers (see Spiegel, 1989, p. 180). As will be noted in Chapter 5, experiments in healthy volunteers still play their role in the development of new drugs, some of them under the new name of proof of concept (PoC) or proof of effect (PoE) studies. 

One of the aims of a validation study is to establish the repeatability and reproducibility precision. Experiments performed under repeatability conditions (see chapter 2) are those repeated over a short period of time, with the same analyst and same equipment. For an analysis, the repeats must be independent, involving the entire method, and not simply the operation of the instrument several times. Reproducibility conditions are the sine qua non of the interlaboratory study. Different laboratories, with different analysts, instruments, reagents, and so on, analyze the sample at different times, but all with the same method. The relationship among these parameters is shown in figure 5.5. 

How far particle size analysis will lead is uncertain. At an elementary level, the ability to confirm or deny the identity of ink in two areas of the same painting would itself be useful (—e.g., in assessing the authenticity of a signature). This author s opinion is that the differentiation of lampblack inks is likely to be difficult or impossible because of the reproducible conditions of carbon manufacture. With pine soot inks (and perhaps others, if they exist) the position is more hopeful since fortuitous circumstances may show that ink made in one place differs from that made in another. With regard to the history of ink, this approach could be applied more often to earlier paintings, and its potential value is obvious. 

High-Viscosity Media (Pastes). The dispersion properties are determined with an automatic muller. The advantage is that small amounts of material can be simply tested under reproducible conditions. For standards, see Table 1 ( Ease of dispersion Automatic muller"). 

Good analyses of triglycerides require careful attention to reproducible conditions and the use of standards and correction factors. Liquid phases that have been used with some degree of success all have high temperature limits in excess of 300°C and include some long-chain hydrocarbons as well as silicone polymery usually polysiloxanes such as OV-1, SE-30, OV-17, SE-52, and JXR (8). ... 

For most of the reported results, a machined notch was made, then a sharp pre-crack formed with a fresh razor blade, using a falling weight apparatus specially designed to operate the blades in reproducible conditions. Quite a satisfactory sharp pre-crack is obtained, as shown in Fig. 10. 

Fig. 11.7 Parallel voltammetric screening of 64 Pt thin film catalysts for the electroreduction of oxygen in acidic solution. In the kinetically controlled region, the activity of all 64 catalysts shows good reproducibility. Conditions 0.5 M H2S04, oxygen saturated 20 mV s 1 anodic scan rate, 60°C, electrolyte stirring, potentials are plotted on the mercury/mercury sulfate electrode scale. Inset voltammogram of 64 Pt thin film catalysts in oxygen-free sulfuric acid, 20 mV s-1, prior to oxygen screening.

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