Materials Literature
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The design and operational features are described for a computer-assisted ellipsometer (called ETA for Ellipsometric Thickness Analyzer), developed to provide reliable, real-time measurement of field-effect transistor gate insulator thickness in a manufacturing environment. ETA illuminates the sample with light of fix…
Abstract Melting and crystallization behavior of virgin polytetrafluoroethylene have been studied using a differential scanning calorimeter. Following quantitative relationship was found between number average molecular weight of polytetrafluoroethylene and the heat of crystallization in the molecular weight range of…
A 3.0-A resolution electron density map of lobster glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) was computed. The essentially single isomorphous replacement map was very substantially improved by averaging subunits. NAD binds in an open conformation at sites close to subunit interfaces. The coenzyme binding…
The appearance of smoke was studied by a video tape recorder. A typical smoke consisted of inner zone, inner front, outer zone and outer front. Smoke particles collected at different parts were studied by electron microscopy. They were large and often showed clear-cut habits in the inner front, while they were small a…
Abstract Poly(phenylene sulfides) were synthesized from m ‐benzenedithiol and aromatic dibromides in a basic medium of potassium carbonate in dimethylformamide or dimethylacetamide. The products obtained were slightly off‐white with relatively low melting ranges and had inherent viscosities in the 0.2–0.4 dl/g range i…
Abstract In a study of pressure‐sensitive adhesives prepared from mixtures of natural rubber and three different tackifying resins, it was shown that a tackifying resin may form either one‐ or two‐phase systems with natural rubber. Measurements of the viscoelastic properties of the adhesives show that the effect of ta…
Abstract Volatilization of NH 3 from NH 4 ‐ ‐N salts applied to the surface of a calcareous soil was investigated. Ammonia losses from surface applied NH 4 F, (NH 4 ) 2 SO 4 , and (NH 4 ) 2 HPO 4 were 68, 54, and 51%, respectively, of the added NH 4 ‐ ‐N in 100 hours. Ammonium nitrate, NH 4 Cl, and NH 4 I lost 18, 18,…
A procedure is described for optimizing the extraction of information from the diffraction data of a glass. A least-squares technique that minimizes the spurious detail in the radial distribution function (RDF) at small and large interatomic distances is employed both to isolate that portion of the total intensity fun…
Abstract A new crystal modification was found in poly(ethylene oxide) stretched about two‐fold after necking at room temperature. An x‐ray diffraction analysis indicated that the planar zigzag molecule passes through a triclinic unit cell with parameters α = 4.71 Å, b = 4.44 Å, c (fiber axis) = 7.12 Å, α = 62.8°, β =…
The solution properties of the nickel(II), copper(II), and zinc(II) derivatives of tetracarboxyphenylporphine (TCPP) and tetra(N-methylpyridyljporphine (TMPyP) have been investigated. At μ = 0. 1 M and 25°, NiTMPyP, CuTMPyP, ZnTMPyP, and ZnTCPP show no tendency to aggregate. However, under these conditions NiTCPP and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray photoelectron spectra of lead oxidesK. S. Kim, T. J. O'Leary, and Nicholas. WinogradCite this: Anal. Chem. 1973, 45, 13, 2214–2218Publication Date (Print):November 1, 1973Publication History Published online1 May 2002Published inissue 1 November 1973https://pubs.acs.or…
Abstract We developed a new micro-scale procedure for determination of protein in cerebrospinal fluid and urine. The sample (50 µl) is mixed with a trichloroacetic acid—Ponceau S dye solution. The proteins, together with a proportional amount of dye, are precipitated and the red precipitate is dissolved in dilute sodi…
Abstract It has been shown that the only way to predict the size of the PTC effect displayed by a crystalline polymer when filled with conductive particles is through the knowledge of the glass transition point of the polymer. The size of the PTC anomaly is found to decrease sharply with rise in glass transition tempe…
Optical transmittance and reflectance of continuously varying anisotropic planar media, such as nematic liquid crystals in Schadt–Helfrich twist cells or cholesterics between parallel rubbed surfaces, have previously been computed with a 4 × 4 matrix method by considering the medium as broken up into many thin paralle…
The ch ange in refractiv e index with temperature has been determined for some oxide glasses from about -200 to 700 C. The chan ge in refractive index with appli ed hydrostatic pressure has been determined at room temperature from a pressure of 10 5 to 10 8 Pa. All measurements were made using the yellow s pectral lin…
Research Papers Tool Wear and Tool Life N. H. Cook N. H. Cook Massachusetts Institute of Technology, Cambridge, Mass. Search for other works by this author on: This Site PubMed Google Scholar Author and Article Information N. H. Cook Massachusetts Institute of Technology, Cambridge, Mass. J. Eng. Ind. Nov 1973, 95(4):…
This article gives a review of the Green-function method for the calculation of the static properties of lattices with point defects. This method, based upon the Born-von Kármán model of a lattice, uses the zero frequency limit of the phonon Green function which gives the static response of the lattice to an applied f…
The role played by inorganic chemical additives in fire retardancy and flame inhibition is considered. Particular attention is given to the molecular level aspects of commercially important systems containing compounds of antimony, halogens, and phosphorus. The flame inhibiting function of metal containing additives i…
Epidermal thickness has been accurately measured on 214 samples of skin from 188 volunteers. Variations with the individual, body site, sex and age are described and discussed. An original technique of measurement has been developed which has several advantages over conventional methods. In particular, quick straight‐…
Abstract Specimens of poly(vinylidene fluoride), crystal form II, annealed at different temperatures between 130 and 180°C were characterized by specific volume measurements, differential scanning calorimetry (DSC), and electron micróscopy. The degree of crystallinity calculated from the specific volume changed only b…