Metals cavities

Lunkerhohlraum, m. Metal.) cavity, pipe, lunker-ig, a. Metal.) containing cavities, honeycombed, vesicular, piped, -los, a. limker-frei. 

One example is the use of rigid selfexpanding closed cell polyurethane foams as a method to inhibit corrosion of the interior surfaces of metal (steel, etc.) structural cavities exposed to seawater and moisture is one of many example of plastic providing corrosion protection. Unfilled metal cavities are a general feature of various structures or products used in the marine, building, electronics,... 

In the case of a hollow metallic resonator as an example for a so-called closed cavity, a discrete set of eigenmodes exists related to a discrete spectrum of eigenmode energies.This is due to the boimdary conditions for the electric and magnetic field that lead to a complete suppression of wave propagation outside the resonator. Hence, no energy is radiated from the hollow resonator the whole radiation field is restricted inside the metallic cavity. 

In order to estimate the e ct of metallic screening on the electrons on the same molecufc, we imagine embedding a molecule in a spherical metallic cavity. Ihc metallic cavity mimics the effect of the metallic electrons on the other molecules in an effective medium approximation. A simple calculation now leads to the following expression for the charging energy, c=... 

Fig. 7. (a) Space-filling models viewed down the 3-fold symmetry axes. The three water molecules coordinated to Zn(ll) in the T-state are shown as striped balls. The exchangeable ligand coordinated to Zn(II) in the R-state is shown as a cross-hatched ball at the center. (b) Cartoons depicting the metal cavities and coordination geometries, (c) Cartoons depicting the extended (T-state) and helical (R-state) conformations of the B-chain residues 1-9. [Redrawn from Smith et al. (41) and Brader et al. (50) with permission.]... 

Anions are attracted in the metal cavity by the positive Zn(N30H2) moiety, and are believed to bind to zinc in carbonic anhydrase very effectively so their use should be avoided as much as possible if the goal is to study the enzyme as it is. When the protein is dialyzed against freshly doubly distilled or carefully deionized water under an inert atmosphere, the pH of the sample approaches the isoelectric point, which is below 6 for HCA I and bovine (BCA II) enzymes. The pH can then be adjusted by appropriate additions of NaOH. All the measurements reported in the literature performed in acetate, phosphate, imidazole, or tris sulfate buffers are affected by the interference of the anion with the metal ion. However, buffer species containing large anions like Hepes (4[(2-hydrox-yethyl)-l-piperazinyl]ethanesulfonic acid) can be used," since these anions do not enter the cavity. 

Automobile Windshield Sealant - (Seals windshield into metal cavity)... 

Solid-state forming basically uses a male metal plug mold that matches a female metal cavity mold and can be used only with crystalline-type resins. Below their glass transition temperatures Tg) amorphous-type resins are generally too stiff to be rapidly formed into stable products. Crystalline types can be permanently deformed at temperatures between their Tg and melting point (Chapter 1). Molecular orientation, the mechanism that allows this to occur, relates to the draw ratio. Draw ratios can vary from 5 1 for PET and nylon to 10 1 for low molecular weight PP. 

Analogy of a perfect blackbody with a hollow metal cavity having a tiny pinhole. [Blatt Communications.)... 

Alkhazov, G. D., Letokhov, V. S., Mishin, V. I., Panteleyev, V. N., Romanov, V. I., Sekatskii, S. K., and Fedoseyev, V. N. (1989). Highly effective Z-selective photoionization of atoms in hot metal cavity, followed by electrostatic confinement of ions. Journal of Technical Physics Letters, 15, 63-67. 

Rotational transitions correspond to photon wavelengths in the microwave region. The radiation sources in microwave spectrometers are klystron tubes, which were originally developed for radar apparatuses in World War II. Hollow metal wave guides carry the radiation to the sample cell, which is a hollow metal cavity, and the resonant radiation in the cavity is sampled to detect absorption. Microwave spectroscopy has played an important role in identifying molecules in interstellar space, but it is not a common tool in many chemical laboratories. 

Microwave integrated electrorrics pl a major role in commimication systems. The growth of satellite commurrication and cellular radio systems has led to the requirement of compact, temperature stable, and low cost filters, hr the early seventies, it was difficult to find a device which could perform as filter, oscillator, and anterma with weight and size features suitable for integration in miniature circuits. For instance, for frequency stabilization, one has to rely upon the bulky expensive metallic cavities which were not integrable. These problems... 

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