Materials Literature
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The Fresnel coefficients describing reflection and refraction at an interface are derived in terms of the elements of the characteristic admittance matrix of an anisotropic medium. The cases considered include the general gyroelectromagnetic medium under normal incidence and the polar and longitudinal orientations und…
Abstract Small‐ and intermediate‐angle (0.006 < Q < 0.25 Å) neutron scattering experiments have been performed on polyethylene terephthalate (PET). Amorphous and semicrystalline samples with deuterated PET molecular weights of 24,200 and 40,500 were prepared. The average value of R /M determined in the small‐ang…
A light-pipe technique has been used to measure infrared spectra of U0 2 , U 3 O 8 , and UO 3 , in the range 2000 to 450 cm −1 . Comparison with transmission spectra found in the literature indicates that the technique is very suitable for characterization of actinide powders and will therefore be a useful tool for fu…
Abstract A method has been developed for the determination of the amount of acid gas produced during the thermal decomposition of PVC formulations. A method was required to support a program to reduce acid gas generation by retention of hydrogen chloride in the char phase. The traditional method (a modified Schoeniger…
The R2Fe14-xSixB compounds with R = Pr, Nd, or Er andx \leq 2crystallize in the Nd2Fe14B tetragonal structure. The Curie temperature increases by ∼ 17 K when one iron atom is substituted by silicon. In the high iron-concentration range the saturation magnetization decreases according to simple dilution behavior. For s…
Abstract Potassium release characteristics of vermiculite samples treated with K and various amounts of Rb, Cs, and Tl were determined using a miscible displacement technique. The amounts of K released, K release rates, and activation energy of K release ( E a ) were specifically examined. Increasing amounts of Rb, Cs…
This paper describes a recently developed standardized system for dull grading natural diamond, PDC, and TSP (Thermally Stable Polycrystalline diamond) bits, otherwise known as fixed cutter bits. The new system is consistent with the recently revised dull grading system for roller bits. It describes the condition of t…
Measurements have been made of the hysteresis of thermally and field-demagnetized sintered specimens of a Nd-Fe-B permanent magnet. Sets of minor hysteresis loops have been obtained by a gradual increase in the maximum applied field thus enabling the intrinsic coercivity and the remanence coercivity to be plotted as a…
SUMMARY Eleven horizons of acidic soils developed from Lower Palaeozoic sedimentary rocks in mid Wales contained varying amounts of poorly ordered minerals. In nine of these over 70% of the phosphate adsorption capacity was attributed to poorly ordered minerals. Iron oxide with substituted Al, and a separate Al oxide,…
The independent crystallization sequence of an Al 2 O 3 component is modified in the presence of SiO 2 and vice versa. Mixed SiO 2 ‐Al 2 O 3 , gel (28 wt% SiO 2 and 72 wt% Al 2 O 3 ) forms neither cristobalite nor γ‐Al 2 O 3 and corundum at 1000°C but forms Si‐Al spinel; an amorphous aluminosilicate phase invariably a…
Sample disks prepared from Al 2 O 3 (61 wt%), SiO 2 (28 wt%), and Fe 2 O 3 (II wt%) powders were sintered at 1270° and 1440°C and then annealed between 1300° and 1670°C. The annealed samples consisted of mullite as the main compound with minor amounts of glass and sometimes magnetite. The iron content of the mullites…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFlexible polymers with excluded volume at a penetrable interacting surfaceJack F. Douglas, Shi Qing Wang, and Karl F. FreedCite this: Macromolecules 1987, 20, 3, 543–551Publication Date (Print):March 1, 1987Publication History Published online1 May 2002Published inissue 1 Ma…
A series of tricomponent blends of poly(vinyl chloride)/chlorinated polyethylene/ethylene propylene diene terpolymer (PVC/CPE/EPDM) were prepared and studied. CPE was used not only to improve the room temperature impact resistance of PVC but also as a polymer compatibilizer; while EPDM was used to enhance the impact r…
Abstract The thermal and isothermal crystallization behavior of PET/PMMA (poly(ethylene terephthalate)/poly(methyl methacrylate)) alloys was investigated. The crystallization of PET is accelerated significantly by alloying with PMMA. As a result, crystalline specimens could be injection molded with the alloy at low mo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural and Stereochemical Studies on Marine Norterpene Cyclic Peroxides, Part 2Robert J. Capon and John K. MacLeodCite this: J. Nat. Prod. 1987, 50, 2, 225–229Publication Date (Print):March 1, 1987Publication History Published online1 July 2004Published inissue 1 March 1…
We have used x-ray diffraction to study the structure of stage-4 through stage-11 potassium-intercalated graphite as a function of temperature. The (00.L) diffraction patterns are analyzed in terms of the Hendricks-Teller model for a disordered one-dimensional crystal. Stage 4--5 samples are best described by phase se…
Abstract The problem of establishing whether or not a certain fibrous textile is the source of a particular single fiber collected from a crime scene is discussed in this paper. A single evidential fiber present at a crime scene can be associated with four major events. These are fiber transfer, persistence after tran…
The field-dependent specific heat of two easy-plane ferromagnetic chains is calculated with extrapolation of numerical results for finite chains. Quantum statistics is applied for the corresponding spin-1 and spin-(1/2) Hamiltonians with single-site and exchange anisotropy, respectively. A drastic reduction of the exc…
A method of using high melting point chain extenders in the synthesis of castable polyurethane elastomers (PU) based on the system polycaprolactone diol (Capa 225) and trans 1,4–cyclohexane diisocyanate (CHDI) was developed based on a semi-prepolymer (quasi) technique in which the high melting point chain extender was…
Modern turbogenerators are designed with high specific loadings. One of the consequences of this is the requirement to design the machine to minimise the size and effects of stator end region leakage fields. This paper describes a finite element method, including both iron saturation and eddy current reaction, to calc…