Sampling speed

Solution Equation 26-16 is simpler than it looks. The factor Kb/Ks is 10 in this case. The length of sample plug injected onto the column is just (sample speed) X (time) = xapp/i The desired injection plug will be 0.50 cm long. The required time is... 

Porous silicon was discovered over 35 years ago by Uhlir.28 The porous material is created by electrochemical dissolution in HF-based electrolytes. Hydrofluoric acid, on its own, etches single-crystal Si extremely slowly, at a rate of only nanometers per hour. However, passing an electric current between the acid electrolyte and the Si sample speeds up the process considerably, leaving an array of deep narrow pores that generally run perpendicular to the Si surface. Pores measuring only nanometers across, but micrometers deep, have been achieved under specific etching conditions. 

If a larger mass range is scanned per unit time, or if a higher resolution is used, the sampling speed must be increased, as the number of data points per unit time increases. 

Sampling speed over 20cm/s lOcm/s lOcmys 1 press/s... 

Figure 11-16 Direct sampling from a conveyor track in a loop configuration eliminates the need for separate equipment to sort specimens but may limit the rate of specimen movement on the track to the sampling speed of the slowest workstation. (From Boyd jC, Felder RA, Savory J. Robodcs and the changing face of the clinical laboratory. Clin Chem 1996 42 1901-10.)...

This introduces samples, standards, or a wash interval to the analytical system in a preset sequence, and at a controlled rate. An unmeasured volume of specimen is added to a polystyrene cup and placed in the sampler tray. Sampling occurs via a polyethylene catheter connected to the manifold of the analytical system. The catheter dips into the cup at preselected sampling rates, usually 20, 40, or 60 times per hour, and between samples a wash fluid or air is aspirated. Both sampling speed and wash cycle are controlled by a timing cam and can be varied. 

A blank determination is carried out on the isopropanolic extracts by eliminating the saponification step. The sample-base mixture bypasses the first 50°C heating bath, and is immediately acidified to pH 6.0 by addition of both the periodic and acetylacetone reagents. Sampling speed for both blank and assay runs is 40/hour, giving a net rate of 20 samples/hour. 

Questionable I-V characteristics should be measured in both directions (double sweeps) at the same sampling speed this serves as a qualitative measure of bias-history hysteresis,... 

The advantages of microchip analysis include the ability to analyze minute samples, speed of analysis, reduced cost and waste, and portability. Ever since, the pTAS has drawn a huge amount of attention, and researchers... 

Testing stratified atmospheres— When monitoring for entries involving a descent into atmosphere that may be stratified, the atmospheric envelope should be tested a distance of approximately 4 feet (1.22 m) in the direction of travel and to each side. If a sampling probe is used, the entrant s rate of progress should be slowed to accommodate the sampling speed and detector response. 

Widmer and colleagues in 1990, in which silicon chip analyzers which incorporate sample pretreatment, separation and detection played a fundamental role [9]. The advantages of microchip analysis include the ability to analyze minute samples, speed of analysis, reduced cost and waste and portability. Ever since, the p.TAS has drawn a huge amount of attention and researchers have been attempting to incorporate a microdialysis-based continuous sampling component. Some of the devices which have been fabricated are shown in Fig. 4. 

Inner radius 15 (xm Outer radius 31.5 p.m Sample temp. 25°C Water sample speed 55 cm/s Sample volume 40 mL (except for HS experiments) Stripping gas N2 Stripping gas flow rate 2.2 mL/min... 

The inertial parameter shows that the likelihood of impact by a particle on the rod increases with the size and velocity of the particle and with decreasing diameter of the rod (i.e. the severity of the deflection). This might be regarded as the simplest model for the capture of dust on an element of a filter. For air sampling on filters velocities are such that the main mechanism of capture is inertia.By this route the efficiency towards capture of the smallest particles becomes critically dependent on velocity one standard test achieved 89% penetration of a paper filter by a 0-3 pm aerosol at 0-025 m/s, but only 15% penetration at Im/s. For routine factory monitoring sampling speeds as high as 0-7 m/s have been employed, " but speeds of less than 0-05 m/s may be encountered if portable battery-operated pumps are used. 

Number of samples Speed [kt] Altitude [ft] Output data after defuzzification Ejection mode... 

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