Experimental setup

The experimental setups for temperature-programmed desorption have evolved with time. As it has been already stated, there are numerous experimental designs that allow the application of this method under the conditions that are the same or very similar to those applied in real catalytic reaction (or any other surface event). Nevertheless, the various equipment used for these experiments, although different, is all constructed to allow two main steps that are common for all thermal desorption methods  

In TPD experiment, gaseous molecules (atoms) of interest are adsorbed at the surface, at constant temperature. The adsorption is very often performed at ambient temperature, but can be sometimes done at sub-ambient or at elevated temperature. In the modifications of technique such as TPO or TPR, gaseous species are consumed while temperature is increased in a programmed manner. In the case of TPD procedure, desorption of adsorbate is monitored while increasing the solid sample temperature in a controlled fashion while in the case of TPR/TPO, the consumption of active gas is monitored during temperature increase, as explained later in more details (see Sect.4.4). 

From previously stated, it follows that temperature-programmed experiments can be performed under ultrahigh vacuum or in the flow of gas. Still, whatever is the experimental design, three main parts of equipment are always necessary to perform this kind of investigations  

Nowadays, two main techniques that are most often used for detection of effluents 

4 The Design of Temperature-Programmed Experiment Obtained Data 

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The development of Remote Field Eddy Current probes requires experience and expensive experiments. The numerical simulation of electromagnetic fields can be used not only for a better understanding of the Remote Field effect but also for the probe lay out. Geometrical parameters of the prohe can be derived from calculation results as well as inspection parameters. An important requirement for a realistic prediction of the probe performance is the consideration of material properties of the tube for which the probe is designed. The experimental determination of magnetization curves is necessary and can be satisfactory done with a simple experimental setup. 

Fig. 5 Experimental setup (left) and result (right) of mean (line scan) refraction intensities of polystyrene and polystyrene blend (right).

Tables I and 2 show the experimental results obtained for axial and transversal displacements respectively, where % is the displacement and Xv. is the displacement measured using our experimental. setup.

Fig. 1 Schematic of experimental setup used for TOFD measurements.

Figure 9.20. Experimental setup for symmetric plate impact test.

Figure 19-1 shows the experimental setup with the position of the steel test pieces and the anodes. The anodes were oxide-coated titanium wires and polymer cable anodes (see Sections 7.2.3 and 7.2.4). The mixed-metal experimental details are given in Table 19-1. The experiments were carried out galvanostatically with reference electrodes equipped to measure the potential once a day. Thus, contamination of the concrete by the electrolytes of the reference electrodes was excluded. The potentials of the protected steel test pieces are shown in Table 19-1. The potentials of the anodes were between U(2u-cuso4 = -1-15 and -1.35 V. 

Fig. 19-1 Experimental setup for the cathodic protection of an active steel concrete-passive steel cell.

For example in paint shops, TCE evaporates and causes air pollution. The contaminated air has 250 ppm TCE in it and this can be fed to a moving bed reactor at 300°C that is charged with OXITOX (Chovan et al, 1997) The kinetics must be studied experimentally. The experimental setup is shown in Figure 4.5.1 and the following description explains the recommended procedure. In the experimental unit shown, the feed is contained under pressure in a gas cylinder. Two percent of the feed is saturated by TCE and diluted with the rest of the feed. The rate is calculated as ... 

The experimental setup uses the ROTOBERTY internal recycle reactor. The catalyst basket of this is charged with W = 35.5 g or V = 44.3 cm of OXITOX that contains 0.25 mol, i.e., 26.5 g of sodium carbonate. 

Figure 1 Schematic diagram showing the basic elements of a MOKE experiment. The angle of incidence, the wavelength of the light, and the orientation of the magnetization, M, relative to the plana of incidence are variables in the experimental setup.

The instrumentation required to measure the hysteresis loop of a ferromagnetic surface with MOKE can be very simple. Figure 4a shows one such implementation of the experimental setup for analysis of ultrathin film samples maintained in a... 

Figure 1 shows a schematic representation of the experimental setup used to study the metal-fullerene... 

Fig. I. Experimental setup the clusters are emitted from the cluster condensation cell, passing as a particle beam through a differential pumping stage into the focus of a time-of-flight mass spectrometer, where they are ionized by a laser pulse.

Clearly, however, there are many ways of changing the experimental setup depending on the aim of the procedure. There are many opportunities... 

An important method for producing semiconductor layers is the so-called molecular beam epitaxy (MBE) (see [3,12-14] and [15-19]). Here, atoms of the same or of a different material are deposited from the vapor source onto a faceted crystal surface. The system is always far from thermal equilibrium because the deposition rate is very high. Note that in this case, in principle, every little detail of the experimental setup may influence the results. 

Figure 4.8. Experimental setup to study flame propagation In a cylindrical geometry.

The TNT blast data used A substantial scatter in the experimental data on high-explosive blast can be observed which is due to differences in experimental setup. Although often referenced differently, most recommendations can be tracked back to ground burst data developed by Kingery and Pannill (1964). 

The experimental setup for high-speed CZE can be seen in Figure 9.8. Highspeed CZE, or fast CZE (FCZE), yielded 70 000 to 90 000 theoretical plates for the separation of amino acid mixtures. Complete separation was achieved in under 11s, using a capillary length of 4 cm (24). 

The experimental setup for a titration is shown in Figure 4.7. The flask contains vinegar, a water solution of a weak organic add called acetic acid. A solution of sodium hydroxide of known concentration is added from a buret. The net ionic equation for the acid-base reaction that occurs is... 

In the continuous wave (CW) experimental setup a sample is constantly illuminated by a probe beam and the steady state change in the transmission is detected (see Fig. 7-1). An argon ion laser has been used to generate the pump beam and the probe beam was from an incandescent lamp (tungsten or others), producing a broad spectrum (0.5 to 5 pm) [6]. Both pump and probe beams are directed onto the sample film and the transmitted probe light is collected, filtered through a monochromator, and detected by a photodetector. Both the pump and the probe... 

Figure 10-2. Experimental setup for pump and probe measurements. Two femtosecond pulses are focused onto the same spot of the sample. The pump pulse-induced changes A7/T0 of the normalized transmission of the probe pulse are measured as a function of the time delay between the two pulses.

Figure 13-8. Typical results for interna, plroiocniission measurements on an ITO/ OPPV/Ca diode at various applied voltages. Tire lines are least-square tils and their extrapolation yields the barrier height for that applied voltage. Inset shows the experimental setup. Reproduced with permission from IIIV1-...

Depending on the sample geometry, the resulting currents may be in the pico- and subpico-ampere range. It is essential either to change the sample geometry or to make sure that the experimental setup resolves these small currents. 

Fig. 8.3. Schematic diagram of ICR experimental setup. Reprinted from Najafpour etal. (2004).18 Copyright with permission from Elsevier.

Fig. 10.5. Continuous stirred tank fermenter, experimental setup with instrumentations and controllers, effluent.

Figure 4.15 Schematic of the experimental setup used in an adiabatic demagnetization experiment.

FIGURE 4-23 Experimental setup for monitoring dopamine release by exocytosis, from a cell body. The microelectrode and glass capillary (containing the chemical stimulant) are micromanipulated up to the cell body. (Reproduced with permission from reference 82.)... 

The experimental setup in this reaction is exactly as that described in Note 2. 

Figure 1.2. Experimental setup used in NEMCA experiments.

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