Special Probes

Anodier class of probes is the fiuorograic probes. These are dyes which are weakly fiourescoit or n mfluo-rescoit until some event occurs, such as en matic cleav- 

A final type of flunogenic jvobe is shown in Hgure 3.29. The probe is soluble and ncmfluorescent prior to 

Another type of fluorescent steroid was used as a probe for the estrogen receptor. This receptcn- plays a role in the growth of hormone-responsive breast cancers, and analysis of receptor levels is an important aspect in the treatment of breast cancer. Estradiol is not fluorescent, so it cannot be 

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The fluorescoice of proteins is usuaify doe to die aromatic amino acids or to bound prosthetic groups such as NADH, FAD, or f doxal pho hate. Howevw, several classes cK 

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Special probe geometries and combinations of different types of magnetic field sensors make an important contribution to the further improvement of the eddy-current testing method and results in new applications. 

As examples two special probe design solutions shall be presented in this paper ... 

Our solution is a matched probe in combination with a special probe holder which enables a fast and reliable inspection on the wings" through a 10 mm inspection hole in the housing of the engine. 

For this purpose a special probe was designed whose contour fits exactly to the actual turbine blade - it has to be positioned on the foot platform and around the comer of the blade, see figure 2. 

Our solution for this inspection problem is a special ultrasonic system consisting of a special probe and a modified pulse-echo ultrasonic instrument. 

In both cases special probes were designed and manufactured For the first ease a special probe which fits geometrically exactly to the contour of the turbine blade and in the other case a combined transducer system was developed which enables a continuous measurement of... 

Disadvantages. Again, a specialized probe-head is necessary to allow the rotor axis to be changed, usually usmg a stepper motor and a pulley system. Angle switching needs to be as fast as possible and reproducible. 

One final technical improvement in soHd-state nmr is the use of combined rotational and multiple pulse spectroscopy (CRAMPS) (2), a technique which also requires a special probe and permits the acquisition of high resolution H and X nucleus nmr from soHds. The combination of these methods permits adapting most of the 1-D and 2-D experiments previously described for Hquids to the soHd phase. 

Cathodic protection installations must be tested when commissioned and at least annually. The potentials should be measured at several points on the bottom of the tank with special probes under the oil, and the height of the electrolyte solution should be checked. The off potential and the protection potential as in Section 2.4 are the means for checking the protection criterion according to Eq. (2-39). 

The purpose of this paper will be to review the distribution of iron compounds in natural material. In regard to structure, emphasis will be placed on the atoms bonded directly to iron. However, for reasons just stated, such a superficial presentation is generally insufficient to explain the mechanism of action of the coordinated iron. We will not be concerned here with the specialized probes needed to obtain hints on the mode of binding of ferrous and ferric ions in macromolecules such techniques have been described elsewhere in extenso (3). 

Inside the dark box main sockets and automation port ensure integration of special probe requirements like incubators. There is provision to insert a fiberoptic-guided light source that accept filters for fluorescent work. The sensitivity of the NightOWL is claimed to enable direct detection of reactive oxygen species, even without enhancers like luminol. 

One is the steric effect. As in the case of amides, the E conformation is disfavored by the steric effect when R is equal to or larger than a methyl group. The second factor is the dipole moment. The E conformation is much more polar than the Z conformation. Because of these factors, esters usually assume the Z conformation and no E conformation is observed. To observe the latter, a special probe is needed. From the foregoing discussion, it is apparent that if R is hydrogen and R a large group, the E conformation might be present. Thus the E form of tm-butyl formate was detected by H NMR spectroscopy at low temperature (84). The barrier was found to be ca. 11 kcal/mol (85). 

Other special probe properties can be built in by suitable ligand modification. For example, 4,7-dihydroxy-l,10-phenanthroline complexes of Ru(II)... 

The classical cure 131,132), apart from special probe construction precautions, is a pulse sequence using a phase device detection cycle in which one exploits the fact that acoustic ringing increases linearly with pulse width while NMR signal follows the sinusoidal nutation-angle curve. In its most elementary form, the cycle is composed of four steps (ideally with null 5) ... 

In chemistry and biochemistry NMR is, in general, applied to liquid samples. The quality of the experimental data is mainly influenced by the spectral resolution and by the signal-to-noise ratio obtained. Building high pressure, high resolution NMR probes for liquid samples has to take into account these constraints. Special probes for variable pressure experiments differ from commercial probes by the presence... 

As already mentioned in Section 2, Lipton et al. used a special probe designed for low-temperature experiments (down to lOK) at strong magnetic fields up to 18.8T and employed — Mg CP combined with... 

In CH3CF2CH3 the two F s split the H -signal into a 1 2 1 triplet. The F-signal, when detected by a special probe, would be a septet. 

Sulfur probe An ionization probe coated with a thin layer of molten sulfur on its conducting tip is used for measurement of shock velocity (Figure 3.18b). This is a special probe which is used in the conducting medium (Sulfur is non-conducting at ambient pressure but becomes conducting at shock pressures as its resistance decreases drastically at such pressures). This property of sulfur allows the R-C network to generate an electrical pulse at the time of arrival of shock wave. 

Usually, microfabrication techniques are used to prepare cantilevers with integrated tips of various shapes, mass and spring constants [197,198]. Depending on the cantilever geometry and material used to construct the cantilever [52], the frequency of commercial cantilevers typically varies from 15 kHz to more than 500 kHz, and the spring constants range from 0.01 to 100 N/m. Micromachining techniques can be used to prepare special probes such as meander-type cantilevers for bidirectional force microscopy [199]. 

Special probes were introduced to measure surface forces in colloidal systems as a function of the ionic strength and the concentration of surfactant molecules [214]. A so-called colloid probe can be prepared by gluing a silica sphere onto a conventional Si3N4 tip [179]. 

For photodissociation experiments, a special probe was constructed to replace the 12.7 mm diameter direct insertion probe normally employed. It consists of a hollow stainless steel tube which has a 38 mm focal length quartz lens vacuum sealed at one end and an extended hollow probe tip at the other. The beam of a Lambda Physik excimer laser operating at 308 nm was passed through the probe and lens into the FTMS cell through a small hole in the center of the trap plate as shown in Figure 1. 

Potentiostat — A potentiostat is an electronic amplifier which controls the potential drop between an electrode (the -> working electrode, (WE)) and the - electrolyte. The WE is normally connected to ground potential the potential of the electrolyte is measured by a special probe, the -> reference electrode (RE). Effects of the -> counter electrode (CE), (e.g., potential drop at the CE electrolyte interface) and the electrolyte (esp. the solution resistance) can be suppressed by this technique. Potentiostats are based on -> operational amplifiers (OPA) the simplest circuit is given in Fig (a). The difference between the desired potential Ureference electrode potential Ure is amplified, resulting in currents via counter and working electrode until this difference becomes (almost) zero. 

Rates of energy fuel use can be determined in several ways. Internal energy fuel use can be measured by a tissue biopsy. A special probe is inserted into the tissue, enabling the researcher to cut out and withdraw a small sample. Biopsies arc sometimes taken from liver and muscle by exercise physiologists. Biopsies per-... 

Selective experiments offer a significant simplification of experiments, and a reduction of dimensionality, instrumentation requirements and data size, and in some cases also of the experimental time. For instance, measurement of spin-spin couplings between rare spin nuclei may require instrumentation for triple resonance experiments, including a special probe. In many cases selective measurements offer simple solutions for these demanding experiments. 

LC-NMR requires use of a special probe that contains a flow cell rather than using a conventional tube. Samples flow into the flow cell, halt for extended acquisitions, and then flow out of the probe to either waste or a fraction collector. The LC-NMR probe is interfaced to the HPLC, using standard chromatographic tubing. LC-NMR flow cells are available in various sizes covering the range of 30-240 pi. 

Fluid bed dryer Sheet dryer Sampling cup (see Fig. 12-20) Collect at end of dryer. Increase speed to change the drying time. Record initial moisture and mass of tray with time. Decrease residence time with higher flow rate and sample at exit. Residence time of product is difficult to determine and change. Special probes have been developed to sample partially dried powder in different places within the dryer (ref Langrish). 

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