Materials Literature
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Varved clays deposited in proglacial Lake Ojibway at Matagami, Quebec, were derived from two source areas: carbonate-deficient, Precambrian crystalline igneous rocks from New Quebec to the east and carbonate-rich Palaeozoic rocks from the James Bay lowlands in Ontario to the west. About 50% of the 12–15 m thick clay s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDirect proton transfer between hydrocyanic acid and nitrogen and oxygen basesRodney A. Bednar and William P. JencksCite this: J. Am. Chem. Soc. 1985, 107, 24, 7126–7134Publication Date (Print):November 1, 1985Publication History Published online1 May 2002Published inissue 1…
A quantitative subjective scale of measurement of fabric stiffness called ‘Stifs’ is described. This is based on the easily measured and readily convertible quantitative objective measurement known as the drape coefficient.
The effects on the reciprocal space of one or more pseudotranslations occurring in a crystal structure are studied. A quantitative theory is described, which gives full account of the subsets of pseudonormalized structure factors whose mean intensity significantly deviates from unity. Conversely, statistical criteria…
The authors report partial and total photoionization cross sections as well as the asymmetry parameter for ionization of the 2σ<SUB>g</SUB>, 2σ<SUB>u</SUB>, and 1π<SUB>u</SUB> orbitals of the ground X <SUP>1</SUP>Σ<SUB>g</SUB><SUP>+</SUP> state of the carbon molecule C<SUB>2</SUB>, which is found in a variety of astro…
A simple model is employed to explain the anomalous surface-flashover characteristics observed when insulators in vacuum are stressed with bipolar voltage waveforms. Under unipolar stress, the flashover field is found to vary as the inverse square root of the prebreakdown time delay over the first few tens of nanoseco…
A theoretical analysis (subject to some assumptions) of the principles of seam slippage in woven fabrics is presented. It is shown that the amount of seam slippage, or fabric resistance to seam slippage, depends on such factors as yarn-to-yarn friction, yarn-to-sewing-thread friction, yarn flexural rigidity, and stitc…
The crystallographic restriction in dimensions two and three is generalized to arbitrary dimensions. It is shown that m can occur as the order of an element of the point group of an n-dimensional space group if and only if Φ(m) ≤ n where Φ is an additive version of Euler's totient function. A table of these allowable…
Three hydrogel formulations consisting of 2-hydroxyethyl methacrylate (HEMA) copolymerized with N-vinyl pyrrolidone (NVP) were incorporated into silicone rubber by irradiation-induced polymerization. These coatings were chosen to represent different degrees of hydrophilicity, and they changed the hydrophobic character…
Ammonium pentaborate (APB) is shown to be an effective intumescent, char- forming additive for thermoplastic polyurethanes (TPU). As little as 5 to 10 parts of APB, added to a flame retarded TPU, provides a 7 to 10-fold improve ment in burn-through resistance. The APB/TPU char is characterized by its glassy, multicell…
The ionic conductivities in glass and glass‐ceramics were studied for Na 3.2 M 0.7 Si 2.9 P 0.1 O 8.7 ( M = Er , Y , Ho , Dy , Gd , Eu , and Sm ) compounds. The results showed comparable conductivity values, in the range of 10 −4 (Ω‐cm) −1 at 280°C, with the glasses being somewhat better conductors. Compounds of the t…
Abstract The composition and/or temperature dependence of the dynamic Young's modulus for the ordered B2 Co-Al, Fe-Al, and Ni-Al aluminides has been investigated using the piezoelectric ultrasonic composite oscillator technique (PUCOT). The modulus has been measured in the composition interval 48.49 to 52.28 atomic %…
Turnip-yellow-mosaic virus, with its stable, highly spherical and monodisperse character, was chosen as a suitable model substance with which to test hydrodynamic theories of transport. Sedimentation coefficients, diffusion coefficients (obtained through photon correlation spectroscopy) and viscosities were measured a…
Abstract In phase behaviour calculations and compositional simulations with an equation of state, it is advantageous to represent the oil and gas systems by a small number of pseudo-components. This paper presents a scheme for determining these pseudocomponents based on the K-values of all constituents that are presen…
The traditional bulk elastic modulus approach to plant cell pressure-volume relations is inconsistent with its definition. The relationship between the bulk modulus and Young's modulus that forms the basis of their usual application to cell pressure-volume properties is demonstrated to be physically meaningless. The b…
Emission spectra of the A<SUP>2</SUP>Π-X<SUP>2</SUP>Σ<SUP>+</SUP> system of MgH have been studied at high resolution and with high signal-to-noise ratio through the use of a Fourier transform spectrometer. On the basis of a rotational analysis of these data, frequencies are predicted for the lowest pure rotational tra…
We describe the preparation of the six configurationally distinct cyclobutane-type photodimers generated by the acetone-sensitized uv irradiation of thymidine in aqueous solution. Also prepared as minor photoproducts are the 5R and 5S di-astereoisomers of 5,6-dihydrothymidine, and two novel molecules, the 5R and 5S di…
Abstract Starting with 2,3,9,10,16,17,23,24‐phthalocyanineoctacarbonitrile ( 3a ) different octa‐substituted phthalocyanines 4a – 7a and 3b – 7b with carboxylic acid, anhydride, imido and amido groups were prepared. IR and UV/VIS spectra are discussed in detail and compared with unsubstituted phthalocyanine ( 1 ). 3 –…
This review describes the current status of methods for characterizing the crosslink structure in network polymers. It is not intended to be an exhaustive summary of the literature itself, but rather a critical survey of key papers in the field. It is hoped that this information will provide researchers with an up-to-…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTC-Hydroxy- and C-methylchlorins. A convenient route to heme d and bonellin model compoundsC. K. Chang and Chariklia SotiriouCite this: J. Org. Chem. 1985, 50, 24, 4989–4991Publication Date (Print):November 1, 1985Publication History Published online1 May 2002Published inissu…