Vacuum glazing

Acetyl-2,5-dimethylthiophene [2530-10-1] M 154.2, b 62°/0.25mm, 105-108°/15mm, 224°/atm, dj 1.086, n D 1.544. Distil the thiophene in a vacuum, or dissolve it in CgH6, shake this with 6M HCl, then wash with H2O, dry the organic layer, evaporate, and distil the residue preferably in a vacuum. [Glaze et al. J Chem Soc Perkin Trans 1 957 1985, Beilstein 17 H 298.]... 

Vacuum glazing (VG) Double glazing unit with evacuated space 0.0001-0.0005 ... 

Vacuum glazing performance (in terms of equivalent thermal conductivity) determined from potrai-tial U-values on the order of 0.5-0.3 W m and a thickness of the evacuated gap d—0.3... 1.0 mm) without taking into account the thickness of the glass panes. 

Vacuum Insulation Panels, Vacuum Glazing, and Aerogel Glazing... 

Elemental chemical analysis provides information regarding the formulation and coloring oxides of glazes and glasses. Energy-dispersive x-ray fluorescence spectrometry is very convenient. However, using this technique the analysis for elements of low atomic numbers is quite difficult, even when vacuum or helium paths are used. The electron-beam microprobe has proven to be an extremely useful tool for this purpose (106). Emission spectroscopy and activation analysis have also been appHed successfully in these studies (101). 

Electrodes are commonly silver fired on with an admixture of glaze, but electroless nickel and vacuum-deposited metals can also be used. A final coating of a glaze over the whole body improves the long-term stability. 

Glaze H2O-VUV, vacuum-UV photolysis of water (xenon excimer lamp) Legrini et al. (1993) ... 

Once sublimation is judged complete the ice water is removed from the centrifuge tube with a pipette and replaced with water at room temperature. This will prevent moisture from condensing on the product once the vacuum is turned off and the tube removed from the flask. The product is scraped from the centrifuge tube with a metal spatula onto a piece of glazed paper. It is much easier to scrape the product from a centrifuge tube than from a round-bottomed test tube. The last traces can be removed by washing off the tube with a few drops of an appropriate solvent, if that is deemed necessary. 

If selective surfaces reduce the radiant losses, the convective losses can be reduced by a convection suppression device, which is usually a transparent honeycomb structure (or lamellae) inserted between the glazing and the absorber surface. The outer surface of the glass may receive an antireflective treatment (to increase transmittance), while the inside surface can have an infrared reflective coating (to reduce outward radiation). Still further improvements can be achieved by enclosing the absorber in a vacuum, which eliminates all convective losses. 

The aim of the solar thermal collector development is to improve and optimize them for the temperature level from 80 °C to 250 °C. There are different approaches like double-glazed flat plate collectors with anti-reflection coated glazing, stationary compound parabolic concentrator (CPC) collectors, evacuated tube collectors, vacuum flat plate collectors, small parabolic trough collectors, linear concentrating Fresnel collectors and a concentrating collector with a stationary reflector. 

The transparent part of the glass vacuum enclosure also functions as an entrance window and thus eliminates the need for an external cover glazing. 

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