The limnology of a small, naturally acidic, highly humic forest lake
Caracteristique d'un lac de Finlande. Phyto-, bacteriozooplancton. Production primaire et respiration. Poissons
Materials Literature
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Icosahedrally Related Decagonal Quasicrystal in Rapidly Cooled Al-14-at.%-Fe Alloy
A decagonal quasicrystal with point group 10/mmm has been found in Al-14-at.%-Fe alloy. Zone-axis patterns of the decagonal phase appearing at the icosahedral positions are reminiscent of the appropriate icosahedral patterns. The symmetry and the angular separation of the zone axes can be obtained from the icosahedral…
Order Electricity and Surface Orientation in Nematic Liquid Crystals
A nematic liquid crystal should present an order electric polarization associated with the gradient of order parameter, in addition to the flexoelectric polarization associated with the gradient of orientation. Using thermodynamical arguments, we show that the order-electricity coefficients are of the same order as th…
Grain-Boundary Resistance in Polycrystalline Metals
Grain boundaries are known to reduce significantly the electrical dc conductivity of polycrystalline metallic materials. In this paper, we give a quantum mechanical calculation of the grain-boundary resistance based on the transfer-matrix approach. The results show an exponential decrease of the conductivity with resp…
Vibration Eigenmodes and Size of Microcrystallites in Glass: Observation by Very-Low-Frequency Raman Scattering
The observation of very-low-frequency bands by Raman scattering in a nucleated cordierite glass is described. The frequency of the maximum of scattering is proportional to the inverse diameter of the particles, which are spherical spinel microcrystallites. It is shown that vibrational surface modes of particles are re…
[Ba x Cs y ][(Ti, Al)3+2 x + y Ti4+8-2 x - y ]O16 Synroc-type hollandites I. Phase chemistry
Abstract A series of [BaxCsy][(Ti, Al)3+2x + yTi4+8-2x-y]O16 hollandites, synthesized at 1250°C and coexisting with ‘reduced ’ rutile, demonstrates complete solid solution between barium and caesium endmembers, and simultaneously between Ti3+ and Al3+. The presence or absence of rutile has only a minor effect on stoic…
Nitrogen–phosphorous antagonism in flame‐retardant cotton
Abstract Phosphorous, as sodium dihydrogen phosphate, and nitrogen, in the form of a urea–for‐maldehyde condensate, were applied to cotton fabric. The flame‐retarding character of each treated fabric was assessed by determining the respective limiting oxygen index. Analysis of the results showed that at the lowest lev…
Effect of radiation chemical treatment on sisal fibers I. Radiation induced grafting of ethyl acrylate
Abstract Radiation induced graft copolymerization of ethyl acrylate onto sisal fibers was investigated. It was fond that the percent added‐on of ethyl acrylate to sisal fibers was prohibitively low when using the direct grafting method due to excessive hompolymerization. The preirradiation method was found to be inval…
Polymers from renewable sources. IV. Polyurethane elastomers based on myrcene polyols
Abstract Two hydroxy‐functionalized liquid rubbers, one a commercially available polybutadiene (PB) and the other a specially synthesized polymyrcene (PM), have been converted into homopolyurethane elastomers by reaction with 4,&4prime;‐diphenylmethane diisocyanate (MDI). Additionally, PB and PM, each in admixture…
Elastic Properties of Charge-Density-Wave Conductors: ac-dc Electric Field Coupling
We have measured Young's modulus $Y$ and internal friction $\ensuremath{\delta}$ of the charge-density-wave (CDW) conductors Ta${\mathrm{S}}_{3}$ and Nb${\mathrm{Se}}_{3}$, in the presence of combined ac and dc electric fields. In the pinned CDW state, the elastic properties are sensitive to even small ac-field amplit…
Poly(2-ethyl-2-oxazoline): A New Water- and Organic-Soluble Adhesive
Poly(2-ethyl-2-oxazoline) is prepared by the ring-opening polymerization of 2-ethyl-2-oxazoline with a cationic initiator. Many of the polymer's characteristics stem from its molecular structure, which has a backbone of alternating two carbon atoms and one nitrogen with a pendent propionyl group off the nitrogen. Rheo…
Statics and Dynamics of the Diffusion-Limited Polymerization of the Conducting Polymer Polypyrrole
We report experimental studies of the statics and dynamics of diffusion-limited polymerization. The fractals obtained were produced electrochemically from neutral precursors, and have a Hausdorff dimension of 1.74\ifmmode\pm\else\textpm\fi{}0.03. The width of the active growth zone increases at the same rate as the fr…
Dielectric properties of an epoxy resin and its composite I. Moisture effects on dipole relaxation
Abstract Dipole relaxation dielectric loss behavior of a fiberglass–epoxy composite has been studied as a function of moisture uptake. A single widely distributed loss peak, centered at −16°C for 10 kHz measurement, is observed in the dry composite. Very low moisture concentrations (<0.1%) interact with the composi…
Noise-Driven Sidebranching in the Boundary-Layer Model of Dendritic Solidification
We suggest that dendritic sidebranches may, under some circumstances, be generated by selective amplification of noisy fluctuations near the tip. Our proposal is based on numerical and analytic studies of the dynamics of the two-dimensional boundary-layer model with kinetic crystalline anisotropy. Certain features of…
Pitting Corrosion Behavior of 6061 Aluminum Alloy Foils in Sea Water
Abstract not Available.
REACTIONS IN THE CHLOROSILANE-SILANOL-SILOXANE SYSTEM
We obtained the first σ∗-values and Es -values for siloxy groups by spectroscopic and kinetic methods. Detailed mechanistic investigations are performed on the hydrolysis of chlorosiloxanes, the cleavage of Si[sbnd]O[sbnd]Si bonds by HCl, and the substituent exchange reaction between silanols and chlorosilanes.
Stress measurements on multilevel thin film dielectric layers used in Si integrated circuits
Thin film induced stresses on silicon substrate were measured at room temperature, using a stress gauge wafer deflection setup. The thermal oxide was in high compressive stress due to CTE mismatch between oxide and Si substrate. As deposited PSG was in tensile stress decreasing in stress level with increasing P conten…
High-Temperature Curing of Radial Passenger Tires
Abstract High temperature curing is feasible with adequate curative modifications. NR-containing compounds are prime considerations. Cure time reductions of about 35% or more are entirely within reason. Use of the modified compounds at conventional or low curing temperatures makes possible significant improvements in…
COMPARATIVE THERMOPHYSIOLOGICAL TESTS ON BLANKETS MADE FROM WOOL AND ACRYLIC-FIBRE–COTTON BLENDS
An account is given of the determination of the thermophysiological properties of two blankets, one made from wool and the other from an acrylic-fibre–cotton blend but otherwise matched in weight and fibre diameter, by laboratory measurements as well as by climatic-chamber tests with human subjects. The tests show tha…
Effects of Ionic Strength, Calcium, and Citrate on Orthophosphate Solubility in an Acidic, Montmorillonitic Soil
Abstract A recent study by the authors of the effects of pH and organic acids on residual orthophosphate solubility in an acidic, montmorillonitic soil (Typic Chromoxererts) was extended to include variations of ionic strength (NaCl background) and Ca 2+ concentration at fixed ionic strength. The objective of the expe…