Materials Literature
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Abstract The literature on rigid polyurethane foam has been reviewed with an emphasis on the gaseous products generated under various thermal decomposition conditions and the toxicity of those products. This review is limited to publications in English through 1984. Carbon monoxide (CO) and hydrogen cyanide (HCN) were…
Abstract Thermal transformations of kaolinite were studied by 29 Si- and 27 Al-MAS/NMR and ESR techniques. In metakaolin, Si is still dominantly in the Q 3 state (three Si atoms bonded to an Si-O 4 tetrahedron) and Al detectable by NMR is in both 4-coordination and 6-coordination. Coordination polyhedra around Al or F…
Als molekulare Lichtwandler können die Eu3⊕- und Tb3⊕-Cryptate der Liganden 1–3 fungieren. Die Komplexe geben charakteristische 1H-NMR-Spektren, und das Eu3⊕-Cryptat läßt sich elektrochemisch reversibel reduzieren (−535 m V vs SCE).
The following new or updated patterns are submitted by the JCPDS Research Associateship at the National Bureau of Standards. The patterns are a continuation of the series of standard X-ray diffraction powder patterns published previously in the NBS Circular 539, the NBS Monograph 25, and in this journal. The methods o…
The thermal protective performance of 21 heat-resistant fabrics made with poly benzimidazole (PBI), aromatic polyamide (aramid), and blends of PBI with aramid or with flame retardant rayon fibers was evaluated in laboratory tests using highly intense exposures to radiant or convective heat sources. The contribution of…
The theory of double exchange is generalized to mixed valence (MV) trinuclear clusters. The results obtained by quantum-theoretical calculations of exchange and resonance splittings are compared to the results of the model theory which takes account of Heisenberg and double exchange. The comparison demonstrates unambi…
The longitudinal end effect in a linear induction motor (LIM) is analysed assuming two travelling magnetic flux density waves in the airgap: the wave travelling with synchronous velocity and the wave representing end effect [1]. A simple equation for the end effect factor which modifies the airgap EMF is obtained, and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, aggregation, electrocatalytic activity, and redox properties of a tetranuclear cobalt phthalocyanineW. A. Nevin, W. Liu, S. Greenberg, M. R. Hempstead, S. M. Marcuccio, M. Melnik, C. C. Leznoff, and A. B. P. LeverCite this: Inorg. Chem. 1987, 26, 6, 891–899Publica…
Summary Casing wear caused by rotation of nonhardbanded tool joints has been investigated with a full-sized test machine. Three grades of casing were used during this study: K55, N80, and PI 10. Tests were conducted in both water-based and oil-based muds. Contact forces between the tool joint and casing were either 1,…
The sodium titanates Na 4 TiO 4 , α, β‐, and γ‐Na 2 TiO 3 , Na 8 Ti 5 O 14 , Na 2 Ti 3 O 7 , and Na 2 Ti 6 O 13 , all of which can be synthesized in the temperature range 800° to 1200°C, have been characterized by X‐ray diffraction (XRD) and Raman spectroscopy. The existing XRD data have been critically reviewed and s…
The binding of multiple deuterium (D) atoms to vacancies in iron (Fe) is investigated both experimentally, by use of ion-beam techniques, and theoretically, by use of the effective-medium scheme. The experimental D-release stages are accounted for by trapping at vacancies with a binding enthalpy that depends on occupa…
A transmission electron microscopy study has been carried out to understand the structural transformation mechanisms of decomposition of Mg(OH) 2 and MgCO 3 under vacuum. Both Mg(OH) 2 and MgCO 3 decompose topotactically to yield porous pseudomorphic MgO of normal structure with definite orientation relationships. The…
The relationship between all the polyoxotungstophosphates related to PW 12 O 40 3− and P 2 W 21 O 71 6− anions was established. A new compound K 10 P 2 W 20 O 70 was synthesized and characterized by infrared and Raman spectroscopy. These properties, and especially the 31 P and 183 W nuclear magnetic resonance spectra,…
The silica‐scaled algae (Synuraceae, Chrysophyceae sensu lato) are compared to other Chrysophyceae, Phaeophyceae and Bacillariophyceae with occasional comparisons to other chlorophyll c‐containing algae, scaled protozoa and oomycete fungi. The silica‐scaled algae have several unique characters which separate them from…
Analytical expressions for the scattering function for a polydisperse Percus-Yevick fluid with Schulz- (\ensuremath{\Gamma}-) distributed particle diameters have been obtained. Results obtained with the expression for selected width factors and particle densities are presented. Comparisons have been made with approxim…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStarburst dendrimers. III. The importance of branch junction symmetry in the development of topological shell moleculesDonald A. Tomalia, M. Hall, and David M. HedstrandCite this: J. Am. Chem. Soc. 1987, 109, 5, 1601–1603Publication Date (Print):March 1, 1987Publication Hist…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPeroxo(tetraphenylporphinato)manganese(III) and chloro(tetraphenylporphinato)manganese(II) anions. Synthesis, crystal structures, and electronic structures.Reuel B. VanAtta, Charles E. Strouse, Louise Karle Hanson, and Joan Selverstone ValentineCite this: J. Am. Chem. Soc. 1…
One of the problems in relation to predicting the rates of defect growth in structures displaying stress corrosion cracking (SCC) is that knowledge relating to realistic stress corrosion crack velocities is very limited. In monotonic slow strain rate tests (SSRTs) taken to total failure at usual strain rates and in te…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBroensted basicity of atomic oxygen on the gold(110) surface: reactions with methanol, acetylene, water, and ethyleneDuane A. Outka and Robert J. MadixCite this: J. Am. Chem. Soc. 1987, 109, 6, 1708–1714Publication Date (Print):March 1, 1987Publication History Published onli…
To ascertain the upper limit of protein thermostability and to evaluate the introduction of additional -S-S- bridges for the enhancement of protein thermostability by site-directed mutagenesis, the stability of cystine residues at 100 degrees C has been investigated in a number of unrelated proteins. All proteins stud…