Materials Literature
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Abstract Field and mineralogical studies, supplemented by chemical analyses of charnockite and its derivative gneisses from one of the quarries between Ramalingapuram and Seshanchavadi along Attur valley have revealed retrogression of charnockite to biotite gneiss and onto ankerite-dolomite-bearing gneiss, involving a…
Equations are derived for the effects of x-ray birefringence at a molecular scale on the intensity of scattering by isotropic amorphous materials. These effects introduce false detail into radial distribution functions calculated by the usual Fourier transformation. They may compromise multiple-wavelength techniques f…
Actinoplanes missouriensis utilizes arogenate as an intermediate in L-tyrosine biosynthesis, while no evidence of prephenate dehydrogenase was observed. Arogenate dehydrogenase has been partially purified by a five-step procedure. The enzyme requires NAD as cofactor. The Km values for NAD and arogenate are 0.2 mM and…
Abstract Macroporous hydro‐ and xero‐gels of bead cellulose, prepared by thermal coagulation of cellulose xanthate after emulsification in an organic liquid immiscible with water, and subsequent decomposition to cellulose II have been modified by crosslinking with epichlorohydrin during the process of preparation as w…
Abstract New resonance Raman scattering (RRS) sequences of vibrational overtone lines of Se 2 − SeS − , S 3 − and Se 3 − have been observed. By a photochemical technique these centres and S 2 − can now be produced in alkali metal bromides and chlorides. Vibrational frequencies from RRS or Raman scattering (in the case…
Abstract The nature and extent of hydrazine adsorption by clays and soils was found to be highly dependent on the suspension pH and on the types of surface functional groups. Under acidic conditions, replacement of Na + by N 2 H + 5 was the primary mechanism for hydrazine retention by every system studied. Most of the…
Cu- and Zn-containing compounds are characterised making use of the Wagner Auger parameter and of the so-called chemical state plots to obtain information on the relative initial-state charge distributions and on the relative extra-atomic relaxation energy. The position in the plots of different classes of compounds i…
Cotton yarn (40 Ne) was sized at squeeze pressures of 22 and 33.8 daN/cm 2 (cor responding to 5 and 25 daN/cm) on a laboratory sizing machine. The weaving per formance of yam sized at the high pressure was better than the yarn sized at the low pressure. This improvement is attributed to increased size penetration, gre…
The special features of synchrotron X-radiation and the types of instrumentation required for a range of synchrotron X-ray diffraction experiments are outlined. A diverse range of applications to inorganic and heterogeneous catalyst systems are discussed. Grazing incidence X-ray diffraction experiments have revealed a…
Clay complexes with surface‐grown nickel(II) basic salts were produced from nickel(II) nitrate solutions containing dispersed layer silicate by homogeneous precipitation using hydrolysis of urea. These clay—nickel(II) salt complexes were obtained with clay having cation‐exchange properties; in contrast, using clay wit…
The ratio d${\ensuremath{\sigma}}_{K}$(\ensuremath{\theta})/d${\ensuremath{\sigma}}_{\mathrm{free}(\mathrm{\ensuremath{\theta}}}$) of the differential cross sections for Compton scattering by K-shell electrons of lead to Compton scattering by free electrons has been measured for an incident photon energy of 662 keV an…
A new type of cation-compensated ${\mathrm{Fe}}^{3+}$ (S=(5/2) center designated [${\mathrm{FeO}}_{4}$/M${]}_{\mathrm{\ensuremath{\beta}}}^{0}$, with M=Li and H, has been found to exist in synthetic iron-doped \ensuremath{\alpha}-quartz, through an X-band electron paramagnetic resonance study. The spin-Hamiltonian par…
Abstract This paper focuses on the problem of scale‐up of two‐phase (e.g., solid‐fluid) reactors. It outlines a class of such reactors which, for first‐order reactions, scale in the familiar single‐phase manner via an analog of the usual residence time distribution formula. The differences lie in the fact that the app…
The dielectric relaxation time τ of KH2PO4 and CsH2AsO4 was investigated in the ferroelectric phase through measurements of the complex dielectric constants in the frequency range between 103 Hz and 109 Hz. Anomalous increase in τ near the domain freezing temperature Tf , considered together with the relation between…
It has been proved that on approaching the line of (first-order or second order) transition between ordered phases a symmetry breaking necessarily occurs within a domain wall. The symmetry breaking in the cases under investigation takes place as a second-order phase transition. Calculations were performed for a reorde…
Structural investigations concerning colour centres in MoO3 are described. The structure of MoO3 is studied by electron diffraction and by X-ray diffraction (powder technique). The films are coloured thermally, optically (UV), and electrically. During the crystallization process, the dangling bonds tend to connect the…
Abstract Medical grade black braided silk suture and pure mulberry silk twisted yarn were grafted with methacrylic acid (MAA) using 60 Co gamma radiation. The effect of various synthesis conditions on the grafting was studied. The addition of methanol in water has a marked effect on the degree of grafting, maximum yie…
The elastic moduli of the entire vitreous range of the system ZnO–P2O5 that can be prepared by melting ZnO and P2O5 oxides in open crucibles have been measured by ultrasonic techniques. The bulk, shear, longitudinal, and Young’s moduli, and the Poisson’s ratio are found to be rather sensitive to the glass composition.…
We optimized the losses in iron-rich metallic glasses by surface crystallization and by annealing in a field perpendicular to the ribbon surface. Both methods lead to a weak perpendicular anisotropy and rotational magnetization processes. The origin of surface crystallization could be traced to the effects of oxygen d…
Two models have been proposed to explain the mechanical strength increase of abraded or indented soda–lime glasses upon aging, namely, crack tip blunting and the release of residual tensile stress near the crack tip. To clarify the mechanism, the time dependence of the strengthening of an abraded soda–lime glass was i…