Materials Literature
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Several techniques useful in the preparation of spores, pollen, hystrichospherids, and similar acid-insoluble microfossils are described. These include oxidation treatments to remove unwanted organic matter; 4 aids in the mechanical separation of organic and mineral matter; and 2 methods for making permanent slides us…
Abstract Improvement in methods of characterizing the stress‐strain properties of vulcanized rubber and of determining its molecular weight prior to vulcanization are described. Experimental results obtained previously by Mullins, Moore, and Watson, in an attempt to relate the physical properties of natural rubber to…
Advantages and disadvantages of x-ray spectroscopy are enumerated. The two energy regions of the method are discussed in reference to differences, resolving power, corrections, and diagrams. Discussions of the extended structures and discrete loss of energy of electrons are presented. Emission bands for sodium, magnes…
Studies of the mechanism of pilling have demonstrated that pilling propensity is determined by the rates of fuzz formation, entanglement, and pill wearoff. Motion pictures of fabrics subjected to an abrading action showed that the abradant acted on exposed fiber sections to pull loops which then opened to form fuzz. A…
X‐ray diffraction data for the high‐temperature phases show that a spinel‐type structure develops with marked orientation at about 925°C. This phase is considered to be an aluminum silicon spinel with vacant cation sites. Mullite is thought to be formed by the decomposition of the spinel. Silica is eliminated progress…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModel Calculation of the Temperature Dependence of Small Molecule Diffusion in High PolymersW. Wilfried BrandtCite this: J. Phys. Chem. 1959, 63, 7, 1080–1085Publication Date (Print):July 1, 1959Publication History Published online1 May 2002Published inissue 1 July 1959https…
When small amounts of lanthana, neodymia, niobia, or tantala are added to lead titanate zirconate compositions near the morphotropic (rhombohedral‐tetragonal) phase boundary, the modified ceramics show piezoelectric planar coupling coefficients of about 0.50 and substantially increased dielectric constants of up to 15…
By applying single‐crystal X‐ray techniques, it is shown that kaolinite transforms to meta‐kaolin and subsequently to a cubic spinel‐type phase by a process of orderlyrecrystallization. The dimensional and directional relations between the phases are established. On the basis of this information, together with the den…
The difficulties encountered in attempting to obtain relationships between the dimensions of knitted fabrics, the properties of the constituent yarns and the variable factors in knitting are discussed. It is suggested that the natural shape of the knitted loop is determined by minimum energy conditions, that the loop…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGrowth and Perfection of Crystals.John E. VanceCite this: J. Am. Chem. Soc. 1959, 81, 13, 3489–3490Publication Date (Print):July 1, 1959Publication History Published online1 May 2002Published inissue 1 July 1959https://pubs.acs.org/doi/10.1021/ja01522a099https://doi.org/10.1…
Complicated magnetic properties of $\ensuremath{\alpha}$-phase iron-aluminum alloys are successfully described from a theory with a few simple assumptions concerning the magnetic interaction between iron atoms. Two interactions are considered: the direct exchange interaction between nearest neighboring iron atoms and…
Stage I recovery (14-65\ifmmode^\circ\else\textdegree\fi{}K) of electron-irradiated, high-purity copper is shown to be composed of at least five substages: ${\mathrm{I}}_{A}$, 14-24\ifmmode^\circ\else\textdegree\fi{}K; ${\mathrm{I}}_{B}$, 24-28.5\ifmmode^\circ\else\textdegree\fi{}K; ${\mathrm{I}}_{C}$, 28.5-33\ifmmode…
The magnetic behavior of iron aluminum alloys has been determined for compositions from 0 to 40 atomic percent aluminum in external fields to 12 kilo-oersteds from 4\ifmmode^\circ\else\textdegree\fi{}K to 300\ifmmode^\circ\else\textdegree\fi{}K. The alloys above 33 atomic percent exhibit antiferromagnetism. Those belo…
A laboratory test method was developed to evaluate corrosion inhibitors for use in various parts of refineries. The apparatus devised could be used for evaluation of oil-soluble and water-soluble corrosion inhibitors for steel at an acid pH and for Admiralty metal inhibitors at an alkaline pH at low concentrations of…
An equation is d eveloped to gi ve pit d epth as a fun ction of collision velocity for pits formed in soft to medium-hard metal plates as a r esul t of collision with liquid dro ps. The rear face of t he target plate must be a free surface. The plate t h ickness must not be less t han 1.5 to 2.0 tim es the drop diamet…
Pertinent works of previous investigators are reviewed briefly. A superior technique for the preparation of experimental glasses of high purity and chemical homogeneity is presented. Devitrification growth‐rate data and traction‐viscosity data are reported for high‐silica glasses of the system Al 2 O 3 ‐SiO 2 . Glasse…
Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative source of high-impact, original research that broadly spans the biological, physical, and social sciences.
Abstract Under conditions of vacuum pyrolysis, the rate of weight loss of dimethylpolysiloxanes varies from one sample to the next in an apparently random fashion. This variation is attributed to catalyzed chain cleavage brought about by trace impurities.
I n meas uring the rates of thermal degradation of polym e rs at constant tempe rat u res in the r ange of 200 0 to 500 0 C, one encoun ters a distortion of t he initial p arts of t he rate cur ves during the time required to h eat the sp ecimen to t he p yrolys is tempe raL ure . This distortion has been largely over…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Structure of Certain Polyazaindenes. II. The Product from Ethyl Acetoacetate and 3-Amino-1,2,4-triazoleC. F. H. ALLEN, H. R. BEILFUSS, D. M. BURNESS, G. A. REYNOLDS, J. F. TINKER, and J. A. VanALLANCite this: J. Org. Chem. 1959, 24, 6, 787–793Publication Date (Print):Jun…