PMR

Fig. 9. The relation of an LMR and PMR transition (a) initial state of magneti2ation (b) the magnetisation and corresponding demagnetisation fields of a ...

Protected-Membrane Roofs. Primitive roofs coveted with earth and sod over sloping wood decks shingled with bark were early examples of protected-membrane roofs (PMRs). Grass and earth provided iasulation and protected the shingled deck from inclement weather. 

In modem PMR constmction, thermal iasulation that is unaffected by water or that can be kept dry ia some manner is required. Extmded polystyrene (XEPS) foam iasulation boards ate commonly employed (see Insulation, thermal). They ate placed on top of the waterproofing roof membrane, which is next to the deck. The iasulation should not be adhered to the membrane. Ballast at the rate of >48.8 kg/m (1000 lb/100 ft ) holds the iasulation ia place and offers protection from the sun. The iasulation joiats ate open and drainage must be provided. Various other materials, eg, patio blocks and concrete slabs, ate also used as sutfaciags and ballast. The extra weight imposes mote exacting requirements on constmction. 

PMR-15—carbon fiber composites include jet-engine cowlings, ducts, compressor blades, and flaps and fairings (24,38). 

Bis-maleimide resins composed of BMI and diamines have been reported in the early 1960s in the patent literature. Since that time, a number of patents have appeared describing improvements in their properties and uses [3]. Although many bis-maleimide resins are commercially developed, relatively few reports of their use as adhesives are to be found in scientific journals [4-10]. Improvements of maleimide resins are mirrored in the improvements of thermosetting polyimides. For example, the method of in situ polymerization of monomer reactants (PMR method) was developed [6]. 

Polyimide by the PMR method should also belong to this category, however, before reaching the final stage of curing, elimination of the alcoholic component seems to be causing reduction of performance. 

Very recently there has been an experimental and theoretical study of electronic substituent effects in 4-aminoaryl (4-substituted aryl) sulfones146. PMR, 13C NMR and infrared measurements were involved and semi-empirical all-valence CNDO/2 calculations, with and without sulfur d orbitals, were carried out. Various correlations between spectral results and substituent constants are presented. There is good agreement between experimental and theoretical data, which does not depend on the inclusion or exclusion of the sulfur d orbitals from the calculations. 

Finally, although strictly outside the scope of this chapter (and book), we mention a study of the transmission of electronic effects in iV-alkylidene-sulfenamides, -sulfinamides and -sulfonamides, XC6H4SO N=CHC6H4OH-2, through measuring the PMR chemical shifts of the o-OH148. The p values lie in the order S < SO > S02 (cf. above) which is attributed to a complex interplay of factors. 

Comparison of Purities of Oxide Feed, DOR Metal, and ER Metal Product, Run PMR 162 ... 

Yamamoto and Yamazaki 171) carried out reactions of Pt(PEt3)2CHjI and Pt(PPhMe2)(CH2CjH5)I with tert-butyl and cyclohexyl isocyanides. These reactions gave small yields of the ionic intermediate species, which readily reverted to the appropriate iminoacyl complexes. In reactions of analogous chloride complexes the intermediate species was not isolated. It is suggested on the basis of PMR data that these iminoacyl complexes are five-coordinate (see above). 

The five-coordinate iridium complexes may be protonated by glacial acetic acid, yielding [Ir(PPh3)2(CNR)3H] + the structure of this complex is determined by PMR measurements to be (XXIX). However, in the analogous HCl reaction [Ir(PPh3)2(CNR)2Cl2] is obtained. The reaction of [Ir(PPh3)2(CNR)3] with methanol also proved quite out of the ordinary. 

The PMRs of several triscyclopentadienyl-lanthanide metal complexes of cyclohexyl isocyanide (C5H5)3MCNCgH, (M = Pr, Nd, Ho, Tm, Yb) are reported 159, 160). 

Goto, T., Takase, S., and Kondo, T., PMR spectra of natural acylated anthocyanins determination of stereostructure of awobanin, shisonin and violanin (Commelina communis, Viola tricolor, Perilla orimoides). Tetrahedron Lett, 27, 2413, 1978. Agrawal, P.K., NMR spectroscopy in the structural elucidation of ohgosaccharides and glycosides, Phytochemistry, 31, 3307, 1992. 

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