Pyrex, applications

Knudsen cells (effusion cells) are exclusively used for vapor pressure measurements (see vapor pressure) in the pressure range from 1 torr to 10-6 torr. In the low temperature range (—20° — +400 °C) pyrex glass cells are applicable. Especially the vapor pressures of dyes, organic compounds can be measured in such cells, because metal cells may sometimes cause catalytic decompositions of the investigated materials. 

Borax decahydrate occurs in nature as mineral, borax (tincal). It is one of the most common sodium borate ores. The compound has several industrial applications. The refined material is mostly used in household cleaning products. It is used to make pyrex and other horosilicate glasses. Borax is added to fertilizers in small quantities as a source of boron, as a trace nutrient for plants. High purity grade borax is used in cosmetics, toilet products and electrolytic capacitors. It also is used in fire retardants, adhesives and herbicides. 

Esveld et a/.81,82 developed a continuous dry media reactor (CDMR) for pilot-scale applications. It consisted of a multi-modal tunnel microwave cavity operating at a frequency of 2.45 GHz with a power range from 0 to 6 kW irradiated on a surface of 0.6 m2. Temperatures of up to 250°C were achieved. A web conveyor travelling at 17 cm min-1 transported the solid-phase reaction mixture to the oven in low, open Pyrex supports closely packed on a polytetrafluoroethylene (PTFE)-coated glass fibre. An open flat bed process was employed to facilitate easy evaporation. 

The obtained results have shown that the configuration where the recirculation tank was irradiated and the catalyst was used in suspension appeared to be the most interesting for industrial applications [73]. Moreover, it was observed that the degradation rate was higher when an immersed lamp was used compared to a system with an external lamp [81]. Therefore, actually the studies in progress are realized in the system described elsewhere [39] consisting of a Pyrex annular photoreactor with a 125-W medium-pressure Hg lamp axially positioned inside the reactor. The separation module containing the flat-sheet membrane was connected to the photoreactor in a recirculation loop. 

The wafers containing the etched trenches are anodically bonded to Pyrex glass to form closed channels. The bond strength thus formed is strong enough to withstand pressures up to 250 bar. At that point a breakdown even takes place in the mono crystalline silicon and not at the bonded interface. Clearly, the indicated structures are useful for HPLC applications. 

Pyrex test-tubes fitted with corks or rubber stoppers and labelled with particulars of the size of drop delivered. It must be pointed out that new smooth platinum wire allows liquids to drop off too readily, and hence it is essential to roughen it by dipping into chloroplatinic acid solution, followed by heating to glowing in a flame this should be repeated several times. Micro burettes sometimes find application for the delivery of drops. 

Fuse, Liquid-Metal, Self-Healing. When mercury replaces the filament of an exploding-wire fuse, it. will break contact by vaporizing upon application of an overvoltage, then make contact by condensing when (he overload disappears. This happens within a heavy-walled capillary tube connecting two reservoirs (see sketch). Evaporation forces mercury from the capillary to break the. circuit Experimental quartz glass and pyrex tubes exhibit da-... 

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