Stable contact

Consequently, due to preferred cis-cis orientation a dimeric structure is observed for the indium complex and an unprecedented cis-trans arrangement in the thallium structure leads to a polymeric aggregate. Further N-NMR spectroscopic studies show that the aluminum and gallium complexes are stable contact ion pairs even in solution whereas the indium and thallium compounds are solvent-separated ion pairs in THE solution. 

There is evidence [19] that the initial absorption at ca. 720 nm within 25 ps belongs to a kind of SSIP of benzophenone radical anion and dimethylaniline radical cation. This peak shifts during 200 — 800 ps to 690 nm. The blue shift corresponds to the formation of the thermodynamically more stable contact ion pair, identified according to work by Hogen-Esch and Smid [20]. Finally the ketyl radical is observed at 545 nm after ca. 2000 ps. 

The liquid is not pulled up the tube by a hypothetical surface tension pulling on the walls, as is suggested by the explanation found in so many elementary text-books—it has never been made clear what is the hook on the wall to which this surface tension attaches itself, nor how the hook contrives to move up the tube in advance of the rising meniscus. The energy relations determine what is the stable contact angle (cf. Chap. V,... 

VTES films could be obtained on a-alumina by retraction from VTES-(a)-chloronaphthalene solutions. This contrasts with the failure of ETES solutions to retract from a-alumina. However, neither the organic liquid or water would give stable contact angles on the films formed by VTES. 

As shown in the previous Sections, the stable contact angles for systems displaying mutual solubility or forming intermetallics are somewhat lower than those for insoluble couples. 

The most stable contact angle should preferably be measured alternatively, the advancing and receding contact angles can be measured and the most stable one can be estimated from them (Eq. (7) or (8) or, hopefully, a more substantiated future theory). 

Ethylene oxide vapor is extremely flammable at concentrations ranging from 3% to 100% and subject to explosive decomposition. Although liquid ethylene oxide is relatively stable, contact with acids, bases, or heat, particularly in the presence of metal chlorides and oxides, can lead to a violent polymerization. 

Low resistance, reliable, temperature-stable ohmic contacts are a prerequisite for the commercialization of SiC device technology. Still, these contacts are not yet satisfactory for a variety of reasons the annealing temperature is too high, the contacts penetrate too deep, they deteriorate when devices operate at elevated temperature, and the contact resistance is quite high. The problem of stable contacts to SiC may be resolved by using refractory metals. Refractory metals can be used to form both carbides and silicides. Silicides appear to provide a stable resistance if carbides are not present [1]. Contact systems based on such metals as nickel, chromium, titanium, cobalt and tungsten have been demonstrated for n-type SiC. Most contact systems for p-type SiC are Al-based and this imposes a limitation on the operating temperature of SiC devices with p-type contacts. 

The problem that remains in all cases is the mechanical and electrical stability of the contact achieved between the metal oxide and the metal. To obtain very stable devices, there must be a good and reliable electrical contact, with a low and stable contact resistance. This is because the metal semiconductor junction that forms at the interface between the metal oxide... 

Tong QK, Markley DL, Fredrickson G, Kuder R. Conductive adhesives with stable contact resistance and superior impact performance. In Proc. 49th Electron. Comp. Technol. Conf. (ECTC) 1999 347-352. Jun. 1. ... 

Figure 18. The dotted lines indicate the profile of elution flow around the outlet. When the isoelectric focusing is finished, the sucrose gradient is eluated by allowing the pump (IS) to convey dense sucrose solution to the inlet (12). At the same time suction is applied to outlet (13) by pump (16). Pump (16) removes liquid faster than pump (15) admits sucrose solution. In this way a very stable contact surface (17) is obtained on a level with the edge of the outlet. It lies between dense liquid rising from the bottom and less dense liquid descending from above. The liquid from above will steadily meet a denser liquid at the contact surface (17). From there it will be conveyed to the outlet and on to a fraction collector. The contact surface of the liquid is kept perpendicular to the gradient. This assures a smooth elution of the bands with the electric field turned on as the electric current passes freely through the contact surface. (Svendsen, 56).

Electrodes are to be in stable contact with the patient and cannot be so well protected as a more remote electronic instrumentation box. 

Tong, Q. K., Markley, D. L., Fredrickson, G., and Kuder, R., Conductive Adhesives wifli Stable Contact Resistance and Superior Impact Performance, Proc. 49 Electronic Components and Technol. Conf., (ECTC), pp. 347— 352(Jun. 1, 1999)... 

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