Coatings hermetic

The application of fundamentally new ECT (Russia patent Jf 2063025) has made it possible to provide high-efficiency defect control accompanied by detecting both small surface defects and more rough under-surface defects under non-magnetic metal layer of 7 mm thick, or surface defects under protection coatings, dye, corrosion, hermetic and other type of layer of 10 mm thick. 

Lead azide tends to hydrolyze at high humidities or in the presence of materials evolving moisture. The hydrazoic acid formed reacts with copper and its alloys to produce the sensitive cupric azide [14215-30-6] Cu(N2)2- Appropriate protection must be provided by hermetic sealing and the use of noncopper or coated-copper metal. 

Chemical degradation can be avoided by using closed stmctures, which may have protective covets or which may be fully hermetic, as well as by using unreactive metals. Barrier coatings ate effective in some cases, and polyethylene—polybutene grease (8) is used in some splicing connectors for telecommunications cable. 

When metal inserts require hermetic sealing, consider coating them with a flexible elastomer such as an RTV rubber, polyurethane, or epoxy system. A second method is to design an annular space or reservoir at one end of the insert from which to dispense the flexible elastomers to effectively create a hermetic seal. Flexible sealants are also used to compensate for differences in the thermal coefficient of expansion between metal and plastic. 

The United States still significantly leads Japan in prodncing special pnrpose and high-strength fibers, in preparing cables from groups of fibers, and in research on hermetic coatings for fibers. 

Fignre 27.3 shows a typical spectroelectrochemical cell for in sitn XRD on battery electrode materials. The interior of the cell has a construction similar to a coin cell. It consists of a thin Al203-coated LiCo02 cathode on an aluminum foil current collector, a lithium foil anode, a microporous polypropylene separator, and a nonaqueous electrolyte (IMLiPFg in a 1 1 ethylene carbonate/dimethylcarbonate solvent). The cell had Mylar windows, an aluminum housing, and was hermetically sealed in a glove box. 

Here and now problems, 26 1025, 1028 Hermetic coatings, in optical fiber strength, 11 143-144... 

On the other hand, the interest towards this field is accounted for by the possibility to create polymeric systems, combining the unique properties of low-molecular liquid crystals and high molecular compounds, making it feasible to produce films, fibers and coatings with extraordinary features. It is well-known that the utilization of low-molecular thermotropic liquid crystals requirs special hermetic protective shells (electrooptical cells, microcapsules etc.), which maintain their shape and protect LC compounds from external influences. In the case of thermotropic LC polymers there is no need for such sandwich-like constructions, because the properties of low-molecular liquid crystals and of polymeric body are combined in a single individual material. This reveals essentially new perspectives for their application. 

YESIR — The Earth of the Sages. The adepts advise their disciples to beware against feeding the Philosophical Earth with too much Mercury during the process of Imbibition. It is simply to be coated or overlaid therewith the Mercury must not float above it to the depth of two or three fingers, for then it will be overwhelmed and submerged thereby. When the Yeser has moderately imbibed, it is to be placed in the Vase, which must be hermetically sealed. 

In order to prevent the exchange of ambient air and gas phases in long-term storage, vials, stoppers, boxes, and bags, used as specimen containers and packaging must be made of nonporous materials and sealed hermetically. Glass, plain metal, synthetic rubber, silicon, polyethylene, and plastic-coated aluminum foils are common for this purpose. The packaging material must be dried and desorbed of contaminated gas before use. 

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