Materials Literature
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Several iron-binding pigments (siderochromes) produced by Pseudomonas fluorescens have been isolated and partially characterized. They include ferribactin and various forms of pyoverdine, as well as some previously unreported compounds. In particular, the existence of ferribactin has been independently confirmed for t…
Abstract Measurements were made of dynamic mechanical response spectra and stress–strain properties at room temperature on films of isotactic polypropylene and low‐density polyethylene prior and after ultraviolet irradiation in a Xenotest 450 apparatus. The period of irradiation that caused a deep deterioration of ult…
We report equipment consisting of the coupling of an electrochemical system for measurement and regulation of oxygen partial pressure (PO2) to a symmetrical thermogravimetric analysis system built on the basis of a Cahn 1000 electrobalance. The electrochemical system allows the measurement and regulation of PO2 within…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsolation, purification, and characterization of high-valent complexes from a manganese porphyrin based catalytic hydrocarbon activation system. Crystal and molecular structure of .mu.-oxo-bis[azido(tetraphenylporphinato)manganese(IV)]Bruce C. Schardt, John A. Smegal, Freder…
We have characterized the process that yields high-speed, bistable, electro-optic switching in the surface-stabilized ferroelectric liquid crystal geometry, at intermediate electric fields. Switching proceeds by a continuous reversal of ferroelectric polarization in regions away from the surfaces of the sample, follow…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation G. G. A. Böhm, J. O. Tveekrem; The Radiation Chemistry of Elastomers and Its Industrial Applications. Rubbe…
We have obtained images of the microstructure in the incommensurate and the commensurate charge-density-wave states of $2H$-Ta${\mathrm{Se}}_{2}$ with the use of superlattice dark-field electron microscopy. Large orthorhombic domains are observed in the commensurate phase. With warming to higher temperatures the incom…
Low-energy, high-resolution electron energy loss spectroscopy has been used to identify the vibrational modes of hydrogen on the semiconducting diamond surface providing the first direct evidence that the (111) 1×1 surface is terminated by hydrogen. The vibrational loss spectrum from the ’’as-polished’’ surface shows…
This article reviews developments in the understanding of X-ray-excited Auger and photoelectron spectra in the light of theoretical developments in atom, molecular and solid-state physics. After reviewing progress in XPS and AES separately emphasis is placed on the inter-relationship between the two fields: Auger rate…
A bubble contact angle method was used to determine interfacial free-energy characteristics of polystyrene substrata in the presence and absence of potential surface-conditioning proteins (bovine glycoprotein, bovine serum albumin, fatty acid-free bovine serum albumin), a bacterial culture supernatant, and a bacterial…
More than 110 species of diatoms were identified from samples collected from Manitounuk Sound, Hudson Bay, in 1978. We presently deal with six genera, belonging to the family Naviculaceae; Diploneis (3 taxa), Gyrosigma (3 taxa), Pinnularia (18 taxa), Pleurosigma (4 taxa), Stauroneis (1 taxon), and Stenoneis (1 taxon).…
Abstract Thermal oxidation of isotactic polypropylene (PP) at 220 and 280°C in air was studied. Gas chromatography–mass spectrometric analysis was used to separate and identify the volatile products of PP oxidation. Twenty‐three products were identified and 15 substances were quantified. The aldehydes are the principa…
A process for the fabrication of uranium dioxide‐uranium dicarbide microspheres for use as an advanced nuclear fuel is described. The uranium‐carbon‐oxygen phase diagram was used extensively in applying thermochemical principles to the combined process of uranium carbide synthesis and kernel sintering. Variation of th…
A ballistic laboratory was designed and built to accommodate the impact of . Kevlar® woven fabric of varying ply levels, while manipulating the geometrical shape, weight, and impact velocity of the projectile. A chronograph system was used to measure the striking and residual velocities of the missile. Empirical relat…
The sequence of the deoC gene of Escherichia coli K12 and the amino acid sequence of the corresponding protein, deoxyriboaldolase, has been established. The protein consists of 259 amino acids with a molecular weight of 27 737. The purified enzyme may exist both as a monomer and as a dimer. On the basis of amino acid…
ABSTRACT The relationship between surface tension and foamability of protein solutions was examined. Proteins including egg albumin, soybean protein, casein, milk whey protein and gelatin were used. Foamability was expressed as “foaming power” which corresponded to the ratio of gas volume to the liquid volume in the f…
Sn 2S 3 is orthorhombic with Pnma, a=8.878 (2), b=3.751 (1), c=14.020 (3) Aring, Z=4, Dm=4.87, Dx=4.75 Mg m -3, Mr=333.6, mu(Mo Kalpha)=11.8 mm -1, and the final R=0.04 for 1335 observed X-ray data. The crystal structure was redetermined using a crystal of improved quality and a diffractometer and applying corrections…
The concept of MDO structures (structures of maximum degree of order) is explained in detail and defined. This concept corresponds closely to the concepts of standard, simple or regular polytypes, it seems, however, to be more adequate for complicated examples. MDO polytypes consisting of equivalent OD layers are trea…
Abstract Metal phthalocyanine oligomers that possess peripheral carboxylic acid groups were prepared by the reaction of pyromellitic dianhydride, a metal salt, urea, and a catalyst. These materials have blue to purple colors with a metallic luster and are soluble in sulfuric acid, dimethylsulfoxide, dimethylformamide,…
Cellulose-negative mutants of Acetobacter xylinum have been isolated. Chemical mutagenesis induced a high frequency of such mutants without significant cell killing. Cellulose synthesis could be activated phenotypically in the majority of the mutants by antibiotics that block RNA or protein synthesis. Therefore these…