Materials Literature
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Abstract The solubility parameters of sixteen polymers have been determined by the turbidimetric titration method. The results agree well with the reported values obtained from swelling and viscosity measurements. The method is sensitive to the choice of nonsolvents and to small changes in the copolymer composition.
Abstract It is assumed that the propagating polymeric radicals have no diffusive mobility in the very highly viscous medium within latex particles. Chain growth takes place on a lattice when the polymeric radical reacts with a monomer present on a lattice site adjacent to that occupied by the reactive chain end. For t…
A systematic approach for finding new nonlinear optical materials is presented. The method is based on the use of the anharmonic oscillator model in conjunction with Miller's rule to estimate the second harmonic generation and electrooptic coefficients of a material, followed by an experimental measurement using a rec…
Samples of isotactic polypropylene have been crystallized at a pressure of 3.86 kbar and under a variety of crystallization conditions. These include isothermal crystallization at five different degrees of supercooling ranging from ΔT=70°C to ΔT=34°C and crystallization by slow cooling from 248°C. Each sample was stud…
Study of collagen composition and in vivo and in vitro collagen biosynthesis and maturation in 10-day-old carrageenan-induced granulomas from female guinea pigs demonstrated that old animals have decreased amounts of neutral salt and acid soluble collagen, decreased in vitro biosynthesis and turnover, and lower ratios…
Abstract LiAlSi 2 O 6 III (high-quartz solid solution) was found to be hexagonal, space group P 6 2 22 (or P 6 4 22), a = 5.217 ± 0.001, c = 5.464 ± .002 Å, Z = 1, D o = 2.395 and D c = 2.399 g/cm 3 . The bond lengths were determined with an accuracy of 0.001 Å for Si,Al–O bonds and 0.005 Å for Li–O bonds. The final R…
The vacuum evaporation rate of the (100) face of pure sodium chloride single crystals has been measured with a vacuum microbalance in the temperature range 450°–650°C. The steady-state vaporization rates of pure crystals with dislocation densities of ∼1 × 106/cm2 were lower by about a factor of two than the maximum th…
Abstract Analysis of Mossbauer effect in layer silicates provides a spectroscopic method for determining valences and coordination of iron. In this study Mossbauer spectra were obtained for amesite, cronstedtite, nontronite, two glauconites, biotite, lepidomelane, chlorite, minnesotaite, vermiculite. stilpnomelane, an…
The plain-knitted structure is shown to be a rationally determinate structure only in the fully-relaxed state; in any other state, the nature of the knitted loop is dependent on the yarn's physical properties, mechanical processing, and knitting variables. The fully-relaxed state is only found after the fabrics have b…
Abstract : A set of displacement equations of motion is proposed that is suitable for the dynamic analysis of fiber-reinforced composites. In deriving the equations, representative elastic moduli are used for the binder, and the elastic and geometric properties of the fibers are combined into effective stiffnesses. Wi…
Abstract Stress‐induced crystallization in a rapidly stretched natural rubber gum vulcanizate has been studied using thermal techniques to follow the development of crystallinity. A special‐purpose analog computer has been assembled and used on‐line to process the thermal and mechanical data obtained in high speed ten…
The electrical resistivity has been measured over the temperature range 1 °K to 120 °K in dilute alloys of nickel with Pd, Cu, Co, Fe, Mn, Cr, V and Ti. The impurity (residual) resistivity is very small for alloys of nickel with its near neighbours in the periodic table, Pd, Cu, Co, Fe and Mn, but is an order of magni…
Abstract— Ultraviolet irradiation of 14 C‐uracil in aqueous solution results in the formation of hydrate and dimer photoproducts. The rate of dimerization increases with increasing uracil concentration, and decreases with increasing concentration of oxygen in solution. The kinetics are in agreement with a model previo…
Abstract The spherulitic growth rate of isotactic polystyrene has been measured in a wide range of temperature by means of a polarizing microscope provided with a hot stage. It was possible to fit the experimental data to theory by choosing a value of 75 for the constant C 2 of the WLF equation. The growth rate parame…
The presence of a stationary crystal in a rotating liquid gives rise to a stationary liquid cell beneath the crystal as predicted from the Taylor-Proudman theorem. Outside this cell, the liquid rotates as an almost solid body, while inside the cell it is shown that a predictable inner flow must arise. The effects of c…
Various anomalous magneto-optic and magnetic properties of Eu 1- x Gd x Se are explained on the magnetic exciton and the magnetic impurity state model. It is shown that the optically active magnetic exciton with the lowest energy is of the type of (5 d –5 d ), that is, 5 d character on the central Eu 3+ and also 5 d o…
Abstract In Bacillus subtilis a series of four enzymes is responsible for the degradation of l-histidine to ammonia, formamide, and l-glutamic acid. The third enzyme of the series was not investigated; the other three enzymes, histidase, urocanase, and formiminoglutamate hydrolase, are induced by l-histidine and repre…
The spectra emitted from N2-doped rare-gas solids at low temperatures, irradiated with x rays, have been investigated in detail. The molecular N2 emission seen in the spectral range 2300–5000 Å consists of the Vegard–Kaplan (VK) A 3Σu+ → X1 Σg+ and the second positive C 3Πu → B 3Πg band systems. The latter is observed…
Abstract A method was developed for the study of starch retrogradation by differential thermal analysis. The kinetics of the crystallisation process were studied using the expression θ8 = exp (‐ kt n ), where θ = the fraction of crystallisable starch remaining uncrystallised at time t. The values for the Avrami expone…
The absolute Seebeck coefficient, electrical resistivity, and thermoelectric figure of merit have simultaneously measured on Bi 97 Sb 3 and Bi 90 Sb 10 alloy single crystals of various orientations between 77°K and 300°K. Under the assumption of independent three valley bands for both the valence and conduction bands,…