Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSteric parameters in drug design. Monoamine oxidase inhibitors and antihistaminesEberhard Kutter and Corwin HanschCite this: J. Med. Chem. 1969, 12, 4, 647–652Publication Date (Print):July 1, 1969Publication History Published online1 May 2002Published inissue 1 July 1969http…
A multistep kinetic process is postulated to describe the pyrolysis of nylon 6–6, phenolic CTL-91LD (a phenolic novalac resin), and their composites. Kinetic coefficients are derived from thermogravimetric analysis data (TGA) at heating rates varying from 3–60°C/min for each component. Three correlation techniques are…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of aquomagnesium tetraphenylporphyrinRussell Timkovich and A. TulinskyCite this: J. Am. Chem. Soc. 1969, 91, 16, 4430–4432Publication Date (Print):July 1, 1969Publication History Published online1 May 2002Published inissue 1 July 1969https://pubs.acs.org/doi/10.102…
Abstract The kinetics of dehydration and decarboxylation as well as the glass transition temperature as a function of anhydride content were measured for poly(acry1ic acid). It was found that the glass transition of PAA is of the order of 103°C and increases with increasing anhydride content, reaching an extrapolated…
Abstract Antiplasticizers are considered to be diluents which when added to polymers result in mechanical property behavior opposite to that of plasticization. The addition of antiplasticizers to certain polymers such as Bisphenol A polycarbonate, polysulfone, and polyvinyl chloride results in the elimination of the s…
Abstract Isotactic polypropylene was decomposed under vacuum at 360, 380, and 400°C, and the volatile products from C 1 to C 12 hydrocarbons were analyzed by gas chromatography. The formation of the main products is discussed on the basis of a free‐radical mechanism in which intramolecular radical transfer is assumed…
Abstract The effects of shear stress on the crystallization kinetics and morphology of linear polyethylene and polybutene‐1 were studied with the aid of a specially designed apparatus. With this equipment, it was possible to heat a thin polymer sample between glass slides to a melt temperature, quench the sample to a…
Slime layers are being studied in our laboratories in an attempt to understand their functions in the control of pollution in natural streams. A method for fixing, staining, and embedding microorganisms in the intact slime has been developed. In this method, epoxy resin discs are placed in a holder and are introduced…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOne-electron oxidation of metalloporphyrinsJ. H. Fuhrhop and David MauzerallCite this: J. Am. Chem. Soc. 1969, 91, 15, 4174–4181Publication Date (Print):July 1, 1969Publication History Published online1 May 2002Published inissue 1 July 1969https://doi.org/10.1021/ja01043a027…
Abstract Starting with specific constitutive equations, methods of evaluating material properties from experimental data are outlined and then illustrated for some polymeric materials; these equations have been derived from thermodynamic principles, and are very similar to the Boltzmann superposition integral form of…
Crystal distortions in Cr associated with antiferromagnetic ordering have been established using electrical-resistance strain gauges. Between 123 and 311\ifmmode^\circ\else\textdegree\fi{}K the observations confirm the existence of an orthorhombic structure associated with the presence of a transversely polarized spin…
Striking evidence for a fundamental covalent-ionic transition in the electronic nature of solids is presented.
The tunneling splitting of the torsional-oscillator ground state of a hindered methyl group is taken into account in calculating the temperature dependence of the proton spin-lattice relaxation time. Thermal vibrations cause spin-independent transitions leading to a fluctuation in the sign of the splitting parameter.…
Using a light-beat laser spectrometer, we observe the relaxation of the thermally excited fluctuations of anisotropy in the nematic phase of $p\ensuremath{-}\mathrm{azoxyanisole}$. We identify the two low-frequency purely dissipative modes recently predicted. A first study of the angular dependence of the width of the…
An analog of proline, 2, 3-cis-3, 4-trans-3, 4-dihydroxy-L-proline, was found in the cell walls of the eight species of diatoms studied and was isolated from the proteinaceous material of the wall of Navicula pelliculosa. The properties of this substance are described; its structure was confirmed by nuclear magnetic r…
On the assumption that in Ni-Cu alloys the spin moment on a Ni atom depends on the local atomic environment, it was possible to find moment values for the various atomic configurations so as to give average moments in reasonable quantitative agreement with the values measured in the ferromagnetic composition range. Th…
The remarkable similarity of the $U$ band originating from the first electronic transition of the ${\mathrm{H}}^{\ensuremath{-}}$ or ${\mathrm{D}}^{\ensuremath{-}}$ centers in an alkali halide to the $F$ band in the corresponding alkali halide is pointed out. The band shape and phonon broadening of $U$ bands in alkali…
The thermal conductivity $K$ between 5 and 100\ifmmode^\circ\else\textdegree\fi{}K was measured on Te-doped samples with excess donor concentrations $n$ ranging between \ensuremath{\sim}${10}^{17}$ and 2\ifmmode\times\else\texttimes\fi{}${10}^{18}$ ${\mathrm{cm}}^{\ensuremath{-}3}$. At temperatures below that of the p…
The resistivities of condensed polycrystal and single-crystal aluminum films have been measured as a function of thickness (1600-36000 \AA{}) and temperature (4.2-300\ifmmode^\circ\else\textdegree\fi{}K). Both the temperature-independent residual resistivity and the temperature-dependent resistivity increase with decr…
Sc2O3 has been transformed at 1000°C and 130 kb from the relatively open C-rare-earth structure type to the monoclinic B-rare-earth form with unit cell dimensions α = 13.173 A, b = 3.194 A, c = 7.976 A, and β = 100.40°. The calculated density, 4.16 g/cm3, represents an increase of 8.3% over the density of C-type Sc2O3…