Mixed polyvalent-monovalent metal coating for carbon-graphite fibers

An improved coating of gasification catalyst for carbon-graphite fibers is provided comprising a mixture of a polyvalent metal such as calcium and a monovalent metal such as lithium. The addition of lithium provides a lighter coating and a more flexible coating when applied to a coating of a carboxyl containing resin such as polyacrylic acid since it reduces the crosslink density. Furthermore, the presence of lithium provides a glass-like substance during combustion which holds the fiber together resulting in slow, even combustion with much reduced evolution of conductive fragments. The coated fibers are utilized as fiber reinforcement for composites

They (Don't) Care About Education: A Counternarrative on Black Male Students' Responses to Inequitable Schooling

Focus group interviews and systematic content analysis of 304 essays written by black male undergraduates refute the dominant message that black men do not care about education. On the contrary, these students aspire to earn doctoral degrees in education despite acute understanding that the education system is stacked against them. The analysis asks what compels that dedication

Carbon isotope anomaly in the major plant C-1 pool and its global biogeochemical implications

We report that the most abundant C-1 units of terrestrial plants, the methoxyl groups of pectin and lignin, have a unique carbon isotope signature exceptionally depleted in C-13. Plant-derived C-1 volatile organic compounds (VOCs) are also anomalously depleted in C-13 compared with Cn+1 VOCs. The results confirm that the plant methoxyl pool is the predominant source of biospheric C-1 compounds of plant origin such as methanol, chloromethane and bromomethane. Furthermore this pool, comprising ca 2.5% of carbon in plant biomass, could be an important substrate for methanogenesis and thus be envisaged as a possible source of isotopically light methane entering the atmosphere. Our findings have significant implications for the use of carbon isotope ratios in elucidation of global carbon cycling. Moreover methoxyl groups could act as markers for biological activity in organic matter of terrestrial and extraterrestrial origin

Toxicity studies of Coolanol 15 Final report, Jan. - Sep. 1965

Toxicity studies of synthetic fluid coolant for manned spacecraft heat transfer system

A Bubble Rising in Viscous Fluid: Lagrange's Equations For Motion at a High Reynolds Number

A gas bubble rising steadily in a pure liquid otherwise at rest at a moderate Weber number is, to a good approximation, of oblate spheroidal shape. Previous analytical calculations of that shape at high Reynolds numbers have ignored viscosity. This paper shows that if one includes viscosity by incorporating Rayleigh's dissipation integral in Lagrange's equations, then the speed of rise is that given by Moore, and the shape is that found for inviscid flow by El Sawi using the virial integral and by Benjamin using Hamiltonian theory

What Really is a Continuous Function?

There are surprisingly many essentially different definitions of continuity even of a real function of one real variable. This paper shows that the definitions in various textbooks published from 1893 to 1992 have some very different consequences, and that one error that was noticed and corrected in 1904 reappeared in a 1907 book

Bubble Rise in a Liquid With a Surfactant Gas, in Particular Carbon Dioxide

When a gas bubble rises in a surfactant solution, the velocity field and the distribution of surfactant affect each other. This paper gives the theory for small Reynolds and internal Peclet numbers if the surfactant is gaseous or volatile, if its mass flux across the bubble and around its surface dominates its mass flux through the bulk liquid, and if slowness of both adsorption and convective diffusion must be allowed for. The theory is tested on the experiments of Kelsall et al. (J. Chem. Soc. Faraday Trans., vol. 92, 1996, p. 3879). Their bubbles rose as expected in a pure liquid until the apparatus was opened to the atmosphere. That significantly slowed the bubbles down. The effect is so sensitive to small concentrations of slowly adsorbing or reacting surfactants that atmospheric carbon dioxide could have caused it, even though it alters the equilibrium surface tension by less than four parts per million in pure air

The Axisymmetric Prandtl-Batchelor Eddy Behind a Circular Disc in a Uniform Stream

Analytical support is given to Fornberg's numerical evidence that the steady axially symmetric flow of a uniform stream past a bluff body has a wake eddy which tends towards a large Hill's spherical vortex as the Reynolds number tends to infinity. The viscous boundary layer around the eddy resembles that around a liquid drop rising in a liquid, especially if the body is a circular disc, so that the boundary layer on it does not separate. This makes it possible to show that if the first-order perturbation of the eddy shape from a sphere is small then the eddy diameter is of order R1/5 times the disc diameter, where R is the Reynolds number based on the disc diameter. Previous authors had suggested R1/3 and ln R, but they appear to have made unjustified assumptions