Telescoping crystallization

Advances in laser technology now allow for solid-state lasers of high beam quality. These beams may be projected from a much smaller auxiliary telescope, which negates the need for optical switching and completely eliminates any main telescope fluorescence. Solid-state YAG lasers are the most common type of lasers commercially available. These lasers use a crystal as the lasing... 

Process Improvements. Phase 1 Benzene was replaced with a safer solvent, toluene, which was also used for the [2 + 2] cycloaddition reaction, thus facilitating the telescoping of the two reactions. However, dichloromethane was added during the work-up to prevent product precipitation. The product was ciystallized from 2-propanol in 80% yield. The phase I of development eliminated the use of benzene and allowed for telescoping of the two chemical steps. However, a solvent exchange from toluene-dichloromethane to 2-propanol was still needed to crystallize the product. The color of the product after this modification was dark-brown. 

The telescope on the Raxis IV++ is mounted at 45° to the ip axis and the goniometer is locked onto the (p axis and the crystal centred as described under (see Centring crystals above). 

The goiuometer head is mounted on the cp circle of the diffractometer. The head has three mutually orthogonal micrometric screws, which permit optical centering of the crystal in the center of rotation of all diffractometer axes. The crystal must not appear to process at all when viewed through the telescope (or a video camera) mounted on the... 

The crystal, mounted on a goniometer head, is placed in the appropriate portion of the instrument that will be used to measure intensities. Then the crystal is viewed through the eyepiece of a telescope mounted... 

Many aluminosilicate glass ceramics are based on framework structures of AIO4 tetrahedra, which, when crystallized, posseses low thermal expansions. This gives the glass ceramics based on them near zero expansions and thus excellent dimensional stability, thermal shock resistance, and mechanical strength. Aluminosilicate glass ceramics are used commercially as telescope mirrors, thermally stable structures for satellites and space probes, gyroscope components, heat-resistant windows, stove tops, and cookware. 

Thanks to a famous scientist named Roger Bacon, crystals help us take a closer look at the world. A long time ago, Bacon discovered that by shaping and polishing quartz, he could make a lens. This lens made small objects look bigger. And that was the start of modern eyeglasses, microscopes, telescopes, and even contact lenses. 

Fig. 9. Intensity-voltage plot (intensity versus A) of 00 beam from a clean W(112) surface (see Fig. 6d). Crystal rotated 5° around [01] axis so that specular beam could be measured (incidence brought 5" closer to [llT] surface direction). The experiment was performed in a post-acceleration tuhe and intensity on screen monitored hy telescopic photometer [data of Chang, (203, pp. 24—25)]. Heavy arrows show theoretical positions Fmax of Bragg maxima of order n calculated according to nX = n( 150.4/ Umax) = 2Uo(6) cos 5 . Identifiable Bragg maxima stand out clearly in the higher voltage range and are displaced by an inner potential of about 19 V. At lower voltage, the curve is complicated and is not well understood.

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