Quartz sample cell

Pulse radiolysis was performed using e from a linear accelerator at Osaka University [42 8]. The e has an energy of 28 MeV, single-pulse width of 8 nsec, dose of 0.7 kGy, and a diameter of 0.4 cm. The probe beam for the transient absorption measurement was obtained from a 450-W Xe lamp, sent into the sample solution with a perpendicular intersection of the electron beam, and focused to a monochromator. The output of the monochromator was monitored by a photomultiplier tube (PMT). The signal from the PMT was recorded on a transient digitizer. The temperature of the sample solution was controlled by circulating thermostated aqueous ethanol around the quartz sample cell. Sample solution of M (5 x 10 -10 M) was prepared in a 1 x 1 cm rectangular Suprasil cell. 

This Synchroscan [68] streak camera system has been used to study the time resolved fluorescence of trans-stilbene in the picosecond time regime. The experimental arrangement [69] is shown in Fig. 20. An acousto-optically mode-locked argon ion laser (Spectra Physics 164), modulated at 69.55 MHz was used to pump a dye laser. The fundamental of this dye laser, formed by mirrors M, M2, M3 and M4, was tunable from 565 to 630 nm using Rhodamine 6G and second harmonic output was available by doubling in an ADP crystal placed intracavity at the focal point of mirrors M5 and M6. The peak output power of this laser in the ultraviolet was 0.35W for a 2ps pulse which, when focused into the quartz sample cell of lens L, produced a typical power density of 10 KW cm-2. Fluorescence was collected at 90° to the incident beam and focused onto the streak camera photocathode with lens L3. The fluorescence was also passed through a polarizer and a bandpass filter whose maximum transmission corresponded to the peak of the trans-stilbene fluorescence. 

FIGURE 1.5 Arrangement for controlling the temperature of the quartz sample cell in the D16 experiments. 

Solutions of the required volume fraction of PVME were prepared by dissolving a known mass of the polymer (p = 1.03 g/cm3) in a known volume of a 0.1 M n-butylammonium chloride solution, itself prepared by dissolving a known mass of n-butylammonium chloride in D20. The clay crystals were prepared as described previously [5], After weighing, a single vermiculite crystal was placed in a quartz sample cell of dimensions 1 x 1 x 4.5 cm, and an appropriate amount of the polymer solution (typically 2.5 cm3) was added to prepare an r = 0.01 sample. The sample cells were identical to those used in the experiments on the LOQ instrument (ISIS, Didcot, U.K.) described in Chapter 5. As usual, the cells were sealed with parafilm and allowed to stand at 7°C for two weeks prior to the neutron scattering experiments to ensure that equilibrium swelling had been achieved [5],... 

Spectrophotometer, such as one of the Beckman model DU series two or more quartz sample cells constant-temperahne baths set at 25, 30, and 40°C lens tissne three 100-mL volumetric flasks clock, stopwatch, or other timer hypodermic syringe abont 20 test tubes plastic pail or large battery jar beaker. 

Fig. 6. Diagrammatic representation of a spectrofluorimeter. 1, radiation source 2, excitation monochromator (filter, prism, or diffraction grating) 3, quartz sample cell 4, emission monochromator 5, photomultiplier tube detector 6, amplifier 7,...

As the laser wavelength is shifted toward the UV, the effect of the laser on the sample becomes even more complex because the majority of the available UV lasers are pulsed nanosecond lasers. These intense UV pulses are also prone to the production of sample breakdown and even the destruction of the surrounding quartz sample cell Consequently, such UV Raman experiments are often performed by focusing the UV laser on a flowing stream or a wire-guided jet so that the UV beam does not have to pass through a quartz-sample interface and so that the excited surface is replaced between shots. ... 

In eqn (9.1), m, and are the mass and heat capacity of system components (photothermal agent, solvent, quartz sample cell, and so on), Tis system temperature, t is time, Qpas is the heating power caused by photothermal... 

Figure 1. Schematic diagram of a U. V. flash T-jump apparatus. 1-power supply (15 kV), 2-discharge capacitor 10 yF), 3-heli-cal U. V. flash lamp, 4-quartz sample cell, 5-electrodes for conductivity detection, 6-leads to high frequency Wheatston bridge.

Figure 8. In-situ UV-Vis spectra during the formation of PVP-protected AuPt (1 1) bimetallic system in the region of l<350nm (a) and 1>350 nm (b). (a) Sampling from the solution of the metal ions in ordinary conditions for preparation at 100 °C with refluxing (b) the solution of the metal ions in a quartz UV cell was heated up to 80 °C without refluxing. (Reprinted from Ref [53], 1993, with permission from Elsevier.)...

Infrared transmission spectra were measured on self supported wafers (2 cm2, 20 mg), in a quartz IR cell allowing sample heating under vacuum and introduction of standardised volumes of gas. The samples were activated under vacuum (106 torr) by heating (1 K.min 1) up to 673 K. 

The pellet charge was about 0.0065 g (0.0060 to 0.0068) into a cell with a 4.0 mm diameter. The holder was placed in the center of a quartz tube, equipped with gas and thermocouple ports and Kapton windows. The amount of sample used was optimized for the Fe K edge, considering the absorption by Si of the catalyst. The quartz tube was placed in a clamshell furnace mounted on the positioning table. Each sample cell was positioned relative to the beam by finely adjusting the position of the table to an accuracy of 20 pm (for repeated scans). Once the positions were fine-tuned, the samples were heated to about 120°C in 5% CO/He at 10°C/min. Then the samples were heated to about 270°C over a 3-hour period. They were held at this temperature for 4 h and then cooled. 

After extraction, samples to be analyzed are dissolved in a solvent, commonly acetonitrile, heptane, hexadecane, or water. A scan of the pure solvent in the sample cell, typically made of quartz (Figure 14.3 [A]), is first obtained. The dissolved sample is placed in the sample cell, which is placed in the sample compartment of the instrument, and a spectrum is obtained. 

Fig. 7. Diagram of spectrophosphorimeter.28 L, light source Mi, Ms, Hilger D 247 quartz prism monochromators Di, D2, chopper discs driven by synchronous motors B, silica plat beam splitter F, 0.5-mm. silica optical cell containing fluorescent screen solution Pi, monitoring photomultiplier P2, fluorescence-phosphorescence photomultiplier Q, fused quartz dewar containing sample cell.

For IR measurements the catalyst was compressed at 4 X 108 Pascal. The disc (18 mm diameter, 20-30 mg) was mounted in a quartz sample holder which was introduced in the adsorption/infrared cell (10). To avoid the reduction of the Pd(II) ions by hydrocarbons, the cell was grease free. Samples were activated according to treatment c. Spectra were recorded on a Perkin Elmer model 125 grating spectrometer. The reference beam was attenuated, and the instrument was flushed with air freed of H20 and C02. 

Infrared Procedures. Acidity Measurements. Zeolites treated as for catalytic experiments (heating in a stream of dry air and equilibration with H20 vapor at room temperature) were compressed at 1000 kg/cm2. The resulting disks (5 mg/cm2) were mounted in a quartz sample holder which was introduced into an IR cell as previously described (18). They were heated slowly under vacuum (the temperature was raised stepwise up to 450° in 5 hours). At 450°C, 02 was admitted, and the cell, connected to a liquid nitrogen trap, was maintained at this temperature for 4-5 hours. Finally the wafers were evacuated overnight at 450° C. The vapor of thoroughly dried pyridine was allowed to equilibrate with the wafer at room temperature. Afterwards, the pyridine was desorbed at a series of increasing temperatures for 15 hours each time. 

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