Stabilization of baseline

Stability of baseline, return to baseline before and after each peak of interest, and minimum use of recorder attenuation. 

A simple emission flame photometer is adequate for Na and K while a more selective emission/absorbance system is necessary for Ca, Mg, and trace metals. The range of trace metals which can be analyzed (e.g., Cu, Zn, Fe, As, Pb, Co, Mo, Se, Cd, Hg) with an instrument depends on the efficiency of atomization, excitation, and light collection, as well as the intensity and stability of the background. Owing to the difficulty of obtaining complete stability of baseline and sensitivity, frequent standardization of instruments is usually necessary. This can... 

Stability of baseline pulmonary function Data analysis Defining the lung edge Defining regions of interest within the lung Correction for tissue attenuation of radioactivity Calculation of dose deposited Expression of results... 

It will take 5-15 min to achieve stabilization of baseline frequency. 

The storage modulus (G ) was recorded at a frequency of IHz under 0.015 strain amplitude until stabilization of the protein network. In order to reduce stress in the sample, G recording started just before the gelation time which corresponds to the time at which G deviated from the baseline. Data were collected and rheological parameters were calculated using Carri-Med 50 software. For each system, the experiments were performed in triplicate. 

Figure 74. Improved thermal stability of an electrolyte by flame retardant HMPN (a, left) DSC traces for baseline electrolyte with (1.68%) and without HMPN in the presence of a fully lithiated graphite anode (Reproduced with permission from ref 523 (Figure 5). Copyright 2000 The Electrochemical Society.) (b, right) SHR of baseline electrolyte with (10.0%) and without HMPN in the presence of metallic lithium. (Reproduced with permission from ref 523 (Figure 6). Copyright 2000 The Electrochemical Society.)...

The low frequency baseline noise of the viscometer can be substantially reduced by careful filtration of samples and regular checking and maintenance of column end fittings and fractional sections of tubing in the system. Figure 5 shows the effect of column screen replacement on the stability of the baseline signal at a flow rate of 1.0 ml/min. 

After 30 min equilibration at room temperature, the measurement run started. An air flow (room air filtered through active carbon) was conveyed over the sensors at a constant rate (lcm3/s) for 10 s to stabilize the baseline. An automatic syringe then suckled Asiago cheese head-space and conveyed it over the sensor surfaces for 60s. The sensors were exposed again to the reference air flow to eventually recover the baseline. The total cycle time for each measurement was 5 min. No sensor drift was experienced during the measurement period. Each sample was evaluated three times and the average of the results was used for subsequent statistical analysis (principal component analysis (PCA)). 

One of the principal qualities of operant behavior is the stability of the behavioral baselines between different executions of the procedure. Even with the present learning task, where the behavior is by definition labile, the possibility of obtaining comparable results on different occasions represents a major advantage of the procedure. The stable behavioral baselines undoubtedly result from the highly standardized experimental environment, where the behavior is measured automatically and there is a minimum of experimenter influence. Automation also permits numerous animals to be tested simultaneously by the same technician, thereby offsetting the cost of the apparatus and the time-consuming nature of the training procedures themselves. 

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