Sollers

A beam from an actual sample will require a more elaborate slit S3rstem for collimation if the sample is broad. The Soller slit (Figure 4-7), a stack of thin parallel plates, is such a system. The reasoning that supports this construction is as follows. Were the sample a point or a line source, a slit between sample and crystal or a slit between crystal and detector would be enough for satisfactory collimation. With a two-dimensional sample, both slits would be needed to get this done. But this arrangement is wasteful of emitted intensity because the detector sees the sample as a line source. To use all the sample area effectively, a system of parallel slits is needed. To eliminate the divergent rays in such a system, the slits must be extended in the direction of the beam, and this leads to the parallel-plate construction in the Seller slit system. 

Fig. 4-7. Diffraction of a divergent beam from a broad sample by a large crystal. Collimation of this beam requires the Soller slit system shown. This system is equivalent to simple slits at A and B with separators provided to make certain that only parallel rays leave the exit slit.

Spectrographs sometimes have two Soller slits. The first, whose function it is to collimate the desired x-ravs, is then placed between crystal and detector. The second and wider-angled slit is interposed... 

S. Zhang, B. Soller, and R. Micheels, Partial leastsquares modeling of near infrared reflectance data for noninvasive in-vivo determination of deep tissue pH. Appl. Spectroscopy 52, 400-406 (1998). 

T. Khan, B. Soller, M. Naghavi, and W. Casscells, Tissue pH determination for the detection of metabol-ically active, inflamed vulnerable plaques using near-infrared spectroscopy an in-vitro feasibility study. Cardiol. 103, 10-16 (2005). 

J. Puyana, B. Soller, S. Zhang, and S. Heard, Continuous measurement of gut pH with near infrared spectroscopy during hemorrhagic shock. J. Trauma 46, 9-15 (1999). 

Soller, D. R. and Berg, R. C., 1992, A Model for the Assessment of Aquifer Contamination Potential Based on Regional Geologic Framework Environmental Geology and Water Science, Vol. 19, No. 3, pp. 205-213. 

Wood WF, Sollers BG, Dragoo GA, Dragoo JW (2002) J Chem Ecol 28 1865... 

Acknowledgement Special thanks to Urs J. Haenggi (Biomer) for information about biotechnological PHB synthesis and literature on stereocomplex formation of poly(lactide). We are also grateful to Dr. Carly Anderson and Dr. Sergei Vagin for their help with this article, as well as Benedikt Simon Soller and Simon Meister for their extensive help with the literature research. 

In this second class of spectrometers, X-ray radiation emitted by the sample, after it has been filtered by a sheet collimator (Soller slits), impacts on a crystal analyser... 

Figure 13.9—Schematic of a sequential, crystal-based spectrometer and the spectrum obtained using the sequential method with an instrument having a goniometer. The Soller slit collimator, made of metallic parallel sheets, collimates the primary X-ray beam emitted by a high power source (SRS 300 instrument, reproduced by permission of Siemens). A typical spectrum of an alloy, obtained by an instrument of this category, having an LiF crystal (200) with 26 angle in degrees as the abscissa and intensity in Cps as the ordinate). Model Philips PW2400 Spectrum, reproduced with permission of VALDI-France.

Fig. 63. X-ray optical system of a Geiger-counter diffractometer by Xorth American Philips Co. Inc. A, X-ray tube target B, Soller slits <7, scatter slit D, specimen Et diffractometer axis F, Soller slits G> counter entrance slit.

The mineralogical composition of all the samples included in the study was determined by XRD, using the same powdered sample prepared for XRF analysis. Measurements were performed using a PANalytical X Pert PRO alphal powder diffractometer (radius = 240 mm) using the Cu Ka radiation (A. = 1.5418 A), with a working power of 45 kV - 40 mA. The incident beam was passed through a 0.04 radians Soller slit, and the diffracted beam passed through a second slit. Moreover, the diffracted beam was Ni filtered. An X Celerator... 

Reed J, Soller H. 1987. Phenolics and nitrogen utilization in sheep fed browse. In Rose M, Ed. Proceedings of the 2nd International Symposium on the Nutrition of Herbivores. Brisbane, Australia University of Queensland Press, pp. 47-48. 

Soller, R.W., Regulation in the herb market the myth of the unregulated industry, HerbalGram, 49, 64—67,... 

Arad, Z., Marder, J. and Soller, M. (1981) Effect of gradual acclimation to temperatures up to 44°C on productive performance of the desert Bedouin fowl, the commercial White Leghorn and the two reciprocal crossbreeds. British Poultry Science 22,511-520. 

Scott A. Graeff, Chief Commercialization Officer Brian Soller, Pres., Prod. Div. 

Friedman, I., Machta, L. Soller, R. (1962) Water vapor exchange between a water droplet and its environment. Journal of Geophysical Research, 67,7. 

X-Ray diffraction data of atenolol are presented in Table 7 (5) The diffraction spectrum was produced by monochromatic radiation from the CuK line (1.542 a) which was obtained by excitation at 55 kV and 2o mA. Recording conditions were as follows. Optics detector slit o.2° M.R. soller slit, 5° beam slit, o.ooo7 Ni filter, 3° take off angle. Goniometer scan at 2°, 2o/min. Detector amplifier gain 16 coarse, 9 1 fine. Scintillation co-... 

Figler, M.H., Weinstein, A.R., Sollers, J.J. and Devan, B.D. (1992) Pleasure travel (tourist) motivation A factor analytic approach. Bulletin of the Psychonomic Society 30,113-116. 

In its simplest form, direct X-ray scatter imaging relies on the use of simple mechanical collimation elements such as pinholes, Soller slits and the like to determine the origin coordinates of a scattered photon. They all achieve spatial resolution of the scatter field at the detector by restricting the angular range over which radiation can reach the detector. Examples of direct tomography in the explosives detection field include the... 

Koushika SP, Soller M, White K (2000) The neuron-enriched splicing pattern of Drosophila erect wing is dependent on the presence of ELAV protein. Mol Cell Biol 20 1836-1845 Kremer EJ, Pritchtird M, Lynch M, Yu S, Holman K et al (1991) Mapping of DNA instability at the fragile X to a trinucleotide repeat sequence p(CCG)n. Science 252 1711-1714 LaFetla EM, Green KN, Oddo S (2007) Intracellular amyloid-beta in Alzheimer s disease. Nat Rev Neurosd 8 499-509... 

Soller, R.W. Evolution of self care with over the counter medications. Clin Ther. 1998, Suppl. C, C134—C140. 

Figure 2.10. The schematic showing how the x-ray beam is collimated by using both the divergence and Soller slits (top). The beam, collimated in-plane by the divergence slit, is further collimated axially by the Soller slits. The coordinates in the middle of the drawing indicate the corresponding directions. The bottom part of the figure illustrates the analogy of Eq. 2.6 with Eq. 2.5.

A proper configuration of the instrument and its alignment can substantially reduce peak asymmetry but unfortunately, they cannot eliminate it completely. The major asymmetry contribution, which is caused by the axial divergence of the beam, can be successfully controlled by Soller slits especially when they are used on both the incident and diffracted beam s sides. The length of the Soller slits is critical in handling both the axial divergence and asymmetry however, the reduction of the axial divergence is usually accomplished at a sizeable loss of intensity. 

The slit box located between the x-ray source and the sample Figure 3.12, left) contains two divergence slits, which control the aperture and the divergence of the incident beam in the vertical plane. The two divergence slits are separated by a set of Soller slits, which limit the divergence of the incident beam in the horizontal plane. The sample holder here is an automatic four-specimen sample changer. 

The second slit box is located on the detector arm between the sample and the detector. The slit nearest to the sample serves as a scatter slit. It is followed by another Soller slit and a receiving slit positioned just before the detector. The detector in this case is a solid-state detector, which is cooled by a built-in Peltier refrigerator enabling to adjust and maintain the detector sensitivity at extremely narrow width to allow only x-ray photons of specific energy to be registered. Monochromatization of the diffracted x-ray beam is, therefore, achieved electronically rather than by physical means (e.g. by a P-filter or a crystal monochromator), which increases the registered diffracted intensity by eliminating losses in the filter or in the monochromator. 

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