Radomes

Radome (radiation dome) is used to cover a microwave electronic communication antenna. It protects the antenna from the environment such as the ground, underwater, and in the air vehicles. To eliminate any transmission interference, it would be desirable not to use a radome since transmission loss of up to 5% occurs with the protective radome cover material. The radome is made to be as possibly transparent to electromagnetic radiation and structurally strong. Different materials can be used such as plastics, wood, rubber-coated air-supported fabric, etc. To meet structural load requirements such as an aircraft radome to ground radomes subjected to wind loads, use is made of RPs that are molded to very tight thickness tolerances. Fig. 4.56 shows a schematic of a typical ground radome that protects an antenna from the 

Figy re 4.56 Antenna (150ft) protected by a plastic radome 

Plastic devices of all types have become vital in the medical industry. Products range from disposables (medical supplies, drug delivery devices, ointments, etc.) to non-disposables and packages to containers to body parts. Packaged drugs include premeasured single-dose disposable units. The diversified properties and behaviors of plastics have developed into an important market for plastics. 

Plastic applications are very diversified ranging from band-aids to parts of the heart. Many examples exist in addition to those being reviewed. 

Abiomed (Danvers, MA) is the manufacturer of the self-contained artificial heart. Of the six patients who received the grapefruit-sized plastic and titanium heart, three remain alive (2003). 

---

Computational strategies and many examples can also be found in Tleh re, W.J., Radom, L., Schleyer, P. von R., and Pople, J. A., Ah Inilw Molecular Otijital fhertry, John Wiley Sons, New York, 1986. 

Fig. 2.7 The addition of a 3d orbital to 2p gives a distorted orbital. (Figure adapted from Hehre WJ, L Radom, p i)R Sdileycr and ] A Hehre 1986. Ab initio Molecular Orbital Theory. New York, Wiley.)...

The second, third, and fourth corrections to [MPd/b-Jl lG(d,p)] are analogous to A (- -). The zero point energy has been discussed in detail (scale factor 0.8929 see Scott and Radom, 1996), leaving only HLC, called the higher level correction, a purely empirical correction added to make up for the practical necessity of basis set and Cl truncation. In effect, thermodynamic variables are calculated by methods described immediately below and HLC is adjusted to give the best fit to a selected group of experimental results presumed to be reliable. 

Even the ion, as calculated later by Radom, has a similar planar... 

I. N. Levine, Quantum Chemistry Fourth Edition Prentice Flail, Englewood Cliffs (1991). W. J. Flehre, L. Radom, P. v. R. Schleyer, J. A. Pople, Ah Initio Molecular Orbital Theory John Wiley Sons, New York (1986). 

L. Radom, Applications of Electronic Structure Theory H. F. Schafer, III, Ed., 333, Plenum, New York (1977). 

Corning 9606 cordierite, 2 MgO-2 A12 03-5 Si02 spinel, Mg0Al203 MgO-stuffed P-quart2 quart2, Si02 low expansion, high transparency to radar missile radomes... 

Conventional thermoforming of sheet and film is appHcable to the production of skylights, radomes, signs, curved wiadshields, prototype production of body parts for automobiles, skimohiles, boats, etc. Because BPA polycarbonate is malleable, it can be cold-formed like metal, and may be cold-roUed, stamped, or forged. 

WJ Hehre, L Radom, P von R Schleyer, JA Pople. Ah Initio Molecular Orbital Theory. New York J Wiley, 1986. 

Aircraft radomes, ducting, spinners and other parts are often prepared from polyester resins in conjunction with glass cloth or mat. The principal virtue here is the high strength/weight ratio possible, particularly when glass cloth is used. Land, sea and air transport applications account for almost half the polyester resin produced. 

---