Typical Case Setup

Mossbauer spectra are usually recorded in transmission geometry, whereby the sample, representing the absorber, contains the stable Mossbauer isotope, i.e., it is not radioactive. A scheme of a typical spectrometer setup is depicted in Fig. 3.1. The radioactive Mossbauer source is attached to the electro-mechanical velocity transducer, or Mossbauer drive, which is moved in a controlled manner for the modulation of the emitted y-radiation by the Doppler effect. The Mossbauer drive is powered by the electronic drive control unit according to a reference voltage (Fr), provided by the digital function generator. Most Mossbauer spectrometers are operated in constant-acceleration mode, in which the drive velocity is linearly swept up and down, either in a saw-tooth or in a triangular mode. In either case. 

In almost every case, experimenters who use the resonant nuclear reactions have chosen to detect and count the gamma rays, but the alpha particles can also be used (Umezawa et al., 1987, 1988a). There seems to be no published comparison of the results using alpha particle and gamma ray detection. Fig 2 shows a typical experimental setup using a gamma ray detector. 

Because of the low volatility of Group 2 compounds, even more extreme methods to ensure that the precursor can reach the substrate have been used. In many cases described in Section IV, a container with the Group 2 element precursor was placed directly inside the CVD reactor adjacent to the substrate. A schematic diagram of a typical reactor setup is shown in Fig. 3.31 This has often led to successful transport of the Group 2 precursor to the heated substrate surface, but it is unlikely that these conditions can be scaled up for practical applications. 

In this case, laser light is focused with suitable lenses to a diffraction-limited spot. For reviews on instrumentation and application see [iv, v]. A typical experimental setup is depicted below... 

The first question that had to be answered was. What were the optimal experimental conditions to photoinduce and photoeliminate birefringence. A typical experimental setup is shown in Figure 13.3. Since the polymer film is absorbing the pump light, we could calculate a maximum film thickness that would not completely absorb the pump beam. This is approximately 4 divided by the initial film absorptivity thus, in the case of pDRlA and pDRlM homopolymers, the useful thickness cannot exceed 300 nm. Obviously, polymers with lower absorptivities at the laser wavelength or with lower chromophore concentration can afford thicker useful films. 

This aspect has led to the production of micro- and nanoelectrospray sources, where the chromatographic eluate flow is in the range 1-10 2 pL/min. A typical instrument setup for nano-ESI experiments is shown in Fig. 1.10. In this case, the supplementary gas flow for spray generation is no longer present and the spray formation is only due to the action of the electrical field. The sprayer capillary, with an internal... 

A typical laboratory setup includes a column, fraction collector, and peristaltic pump connected with flexible tubing. In some cases an on-line spectrophotometer may be useful, but generally the large number of UV-absorbing compounds in the feed results in data that has a weak, or no, correlation with product adsorbance. The standard practice is to collect the column-effluent fractions and perform analysis by methods such as HPLC to determine product concentration in the effluent. 

Another strategy to synthesize the particle from volatile organometallic precursors is achieved by promoting homogeneous gas-phase nucleation, the so-called chemical vapor synthesis (CVS). " In this case, the precursor is evaporated using a carrier gas and reacted with a co-substrate (e.g., O2) to produce the desired material, which can be collected as powder. The typical experimental setup is assembled according to Figure... 

One prerequisite to get precise affinity values in ITC is related to the shape of the binding isotherm and thus the affinity of the compoimd. A typical experimental setup using 20 pM of a target protein would enable to determine accurate affinity values in the range of Ap = 5 pM to about 5 nM. If affinities are either lower (e.g., fragments or primary HTS hits) or higher (e.g., advanced compounds in lead identification and/or optimization), one has to use competition experiments, also referred to as displacement ITC [35]. In the case of weakly binding... 

Figure 4-501 shows a typical diverter system setup. The components of the system are the annular preventer, vent lines, the control system, and the conductor or structural casing. 

A typical sorption experiment involves exposing a polymer sample, initially at an equilibrium penetrant concentration of c to a bathing penetrant concentration of Ci. The weight gain or loss is then measured as a function of time. The term sorption used in this context includes both absorption and desorption. The sorption is of the integral type if c° = 0 in the case of absorption or if cf = 0 in the case of desorption. Details of the experimental setup for the sorption measurement are discussed elsewhere [4],... 

TABLE 12.2 Theoretical Peak Capacity, Orthogonality, and Practical Peak Capacity of Investigated 2DLC Setups. Second Dimension was in All Cases Carried Ont Using Cig Column and Typical LCMS Compatible Elution Conditions... 

A 2D experimental setup is composed of two independent HPLC systems that are connected to each other by an electrically (or pneumatically)-driven fraction transfer device. Typically, in the first dimension a detector is not used. In the case of an off-line system after the first dimension a fraction collector is used. The most efficient way to connect the first and second dimensions is to use an automatic fraction transfer valve (Kilz, 1992 Kilzetal., 1993,1995). A schematic presentation of a 2DLC experimental setup is shown in Fig. 17.3. 

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