Beam Configurations

To evaluate the influx solution experimentally for an A/B cantilever beam configuration as shown in Fig. 1, we apply Griffith s theory at the critical moment of fracture, such that the incremental change in stored elastic energy U. with change in crack length a, is Just sufficient to overcome the fracture surface energy S... 

Diode-array spectrophotometers have no moving parts, or at most a shutter that moves thus they are more suited to locations near the process. However, these instruments still require the introduction of the sample into the instrument s sample cavity, as well as the necessity for a separate reference measurement. These instruments are usually only found in a single-beam configuration. 

If the individual wavepacket solutions of the present theory could be superimposed, this would imply that the field vectors become multivalued at every point inside the photon beam. The individual photon fields would then have to cancel each other. This implies that the axisymmetric small-scale wavepacket solution of Section VII does not apply and cannot satisfy the basic Eqs. (l)-(8) in the case of a nearly plane (one-dimensional) and broad photon-dense beam configuration. 

A newly installed computed tomography (CT) scanner was used in this study. This is a modified unit of the third-generation fan-beam configuration originally devel-... 

Figure 6.1 Comparison of 26 — 6 scan profiles obtained by a monochromatized (pure Cu kal) parallel beam configuration (hybrid x-ray mirror) and a conventional parallel beam configuration achieved by divergence slit (ds) module measured at 001/100 (a), 002/200 (b), 003/300 (c), 004/400 (d) of 500nm-thick Pb(Zro.B4Tio.46)03 thin film. Dotted lines represent the second derivative of the profiles, indicating the peak positions. Note that the profiles are simulated fitted profiles for obtained spectrum using pseudo-Voight function (mixed Lorentz and Gauss function).

We have developed a novel ultrasensitive detection method, thermal lens microscopy (TLM), for nonfluorescent species [13]. TLM is photothermal spectroscopy under an optical microscope. Our thermal lens microscope (TLM) has a dual-beam configuration excitation and probe beams [13]. The wavelength of the excitation beam is selected to coincide with an absorption band of the target molecule and that of the probe beam is chosen to be where the sample solution (both solvent and solute) has no absorption. For example, in determination of methyl red dye in water, cyclohexane, and n-octanol, a 514-nm emission line of an argon-ion laser and a 633-nm emission line of a helium-neon laser were used as excitation and probe beams, respectively [21], Figure 4 shows the configuration and principle of TLM [13]. The excitation beam was modulated at 1 kHz by an optical chopper. After the beam diameters were expanded, the excitation and probe beams were made coaxial by a dichroic mirror just before they were introduced into an objective lens whose magnification and numerical aper-... 

At ELYSE, two consecutive laser pulses (Af = 2 ms) are picked from the 1 kHz probe laser pulse train in a single-wavelength, dual beam configuration. The first pulse is synchronized with the acceler-... 

A variant of the crossed-beam geometry, simpler but efficient in some cases, is the beam-gas arrangement. It leads usually to much larger signal than in the crossed-beam configurations, at the expense of a less accurate definition of the reaction kinematics. It is used fairly often to study the total cross-sections of chemiluminescent processes, especially when the species which is to be put into the beam is refractory, as are the transition metals [39, 40]. Reactions of alkaline earth metal atoms have been studied by this technique [41]. 

Standard Mode I Double Cantilever Beam specimens for delamination testing of a unidirectional (UD) IM7/977-2 composite were Z-pinned with two separate blocks of Z-Fiber reinforcement. The reinforced beam configuration was such as to provoke an unstable delamination, propagating between the two Z-pin blocks. Crack resistance curves for these specific geometry specimens of IM7/977-2 indicate that the unstable delamination cracks are arrested by the second Z-pin block, with the crack propagation resistance being dictated primarily by the Z-pinning density within a block. Acoustic emission analysis is used to interpret visual observations and other test data. 

Shutters. On open-beam configurations, each port on the source housing shall be equipped with a shutter that cannot be opened unless a collimator or coupling has been connected to the port. 

The main advantage of the crossed-beam configuration is a better definition of the collision energy which is an important feature at low projectile energies since if a reaction chamber is used one introduces a complicating factor in the form of the random thermal motion of the target molecules. 

The simplest instrument configuration is the single-beam configuration, in which a single light beam is transmitted from the source through the described modules... 

The dual beam configuration of LDA is most widely used today, where the Doppler difference frequency is directly measured and the receiving optics may be placed at an arbitrary position with respect to the transmitting beams. Laser-Doppler anemometry has been first applied to measurements of mean velocities and turbulence properties in single phase flows. In this case small particles, which follow the flow and the turbulent fluctuations, need to be present in the flow or must be added to it (i.e. seeding the flow with a tracer). The principles of LDA are, for example, described in detail by Durrani and Greated (1977), Durst et al. (1981), and Durst et al. (1987). 

Y. Yang, Thermal Lens Spectrometry Based on Single-Laser/Dual-Beam Configuration with Lock-in Detection. Proc. Int. Conf. Lasers, (1985) 445. 

All specimens were constructed in a honded-beam configuration. Aluminum adherends were used in both the static and dynamic DCB configurations, and the composite adherends were used in the static and dynamic DCB and dynamic ELS and SLB configurations. Aluminum (6061) adherends were P2 etched to provide an adequate bonding surface and a bondline of either 0.8 mm or 0.5 mm was used. Because they were shipped in panel form, the composite adherends were bonded in 300 x 300 mm sheets. Each surface was abraded and then cleaned with acetone prior to bonding. The bondline was agmn set using either 0.8 mm or 0.5 mm wire at the center and 20 mm from both ends of the composite panels. Initially, this wire was only placed at the ends of the panels, but this resulted in inconsistent bondlines due to deformation at the center of the composite panels. Once the bondline thickness was set, a thermocouple was added to the center of the specimen to monitor the bondline temperature profile. 

If a tube lens is in the fluorescence detection path, the beam configuration may be slightly different than that shown in Fig. 5.90. The microscope may also have additional lenses in the beam path to project an image on a camera, or to increase the light-collection area of direct detection. In any case, there is a simple way to find the image of the microscope lens behind the field lens Turn on the microscope lamp in the transmission beam path, so that the condenser lens fully illuminates the aperture of the microscope lens. The image of the microscope lens can then easily be found by holding a sheet of paper behind the field lens. 

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