Gas evolution from a solid following de-trapping and diffusion during tempering

The gas evolution rate from the surface of a solid is determined as a function of temperature during controlled heating of the solid, for the case where it is assumed that gas atoms are initially trapped at centres requiring an activation energy E for stimulation into a diffused mode. Diffusion then proceeds with a different activation energy Q. The initial location of atoms is assumed to be a plane, depth pλ below the surface and the heating function is assumed to be 1/T = 1/T_o ? bt. Even in this simplified case it is shown that although the release rate can be expressed as a formal mathematical function of temperature, numerical evaluation is necessary for each value of E, Q, b and pλ.     

Doping directed at the oxygen sites in Y1Ba2Cu3O7−δ: The effect of sulfur,fluorine, and chlorine

We have investigated the effect of three dopants directed at the oxygen sites in Y₁Ba₂Cu₃O_7?δ : sulfur, fluorine, and chlorine. Single-phase material has been obtained up to a (nominal) replacement of ～1% of the oxygen. Although the lattice parameters are unchanged, all dopants raiseT _c (very slightly), sharpen the resistive transition, reduce the normal state resistivity, and very substantially increase the (magnetically determined) fraction of the material that is superconducting. All of these results differ qualitatively from those obtained with dopants directed at other locations in the 123 structure, and it is suggested that small additions of sulfur, fluorine, or chlorine may help to stabilize the ideal 123 stoichiometry.     

Kinetics of Domain Growth in Ordered Ni4Mo

The kinetics of domain growth in Ni4Mo in the temperature range of 600 to 850 °C were investigated using transmission electron microscopy. It was found that domain growth in Ni₄Mo is analogous to metallurgical grain growth and can be described by the expressionD ⁿ =kt, whereD is the average domain size, t is the aging time, k is a constant, and the exponent n is the reciprocal of the slope of the log D vs log t plot. The value of n changed with temperature from 2.0 at 850 and 800 °C to 2.9 at 700 and 600 °C. This change was explained in terms of relative domain orientation effects. The activation energy for domain growth was obtained as 69 Kcal/mole (2.9 × 105 Joules/mole) in the temperature range of 800 to 850 °C and as 92 Kcal/mole (3.85 x 105 Joules/mole) in the temperature range of 600 to 700 °C, which on comparison with available diffusion data established that the growth process was interface-controlled at the higher temperatures and bulk diffusion-controlled at the lower temperatures.     

Novel p.s.k. tanlock loop

A new loop for coherent demodulation of suppressed carrier phase-shift-keyed (p.s.k.) signals is presented. The p.s.k. tanlock loop (p.s.k.-t.l.l.) has a wider tracking range and faster phase acquisition than the Costas or squaring loops usually used for p.s.k. suppressed carrier tracking, but it has a greater tendency to false lock.     

Interaction of lysine with pectin

The interaction of l-lysine with citrus pectin was studied in a model system to determine under what conditions it would occur and whether it would be of physiological significance. Thirty-nine per cent of the lysine was non-diffusible at pH 7, when the pectin concentration was 0·5% and the lysine concentration was $\text{2 × 10}{}^{\mathrm{?3}}\text{M}$. Of this, 29% was restricted due to the Donnan effect and the remainder was specifically bound. Increasing the pH (in the range 6–8) and the pectin concentration both increased the non-diffusible lysine. Increasing the ionic strength and the degree of esterification both decreased the non-diffusible lysine. It was concluded that lysine would not bind to pectin in the intestine because of the high salt concentration there.     

On artificial vorticity in numerical simulation of incompressible flow

For incompressible flows the addition of artificial vorticity in the vicinity of wall barriers can be useful in the numerical satisfaction of no-slip. It is shown that a method of Briley which appears to have order one error near the wall is in reality a clever means of inducing the no-slip condition through implicit addition of artificial vorticity to the calculations. This appears to explain the rapid convergence experienced by Briley's method.     

Study of transmission response of edge filters employed in wavelength measurements

The ratiometric wavelength-measurement system is modeled and an optimal design of transmission response of the employed edge filter is demonstrated in the context of a limited signal-to-noise ratio of the signal source. The corresponding experimental investigation is presented. The impact of the limited signal-to-noise ratio of the signal source on determining the optimal transmission response of edge filters for a wavelength-measurement application is shown theoretically and experimentally.     

Evaluation of two commercial lateral-flow test kits for detection of animal proteins in animal feed

Performance characteristics were evaluated for two lateral-flow test kits, Reveal for Ruminant in Feed (Neogen Corporation) and FeedChek (Strategic Diagnostics Inc.), designed to detect ruminant or terrestrial animal proteins in feeds. The stringent acceptance criteria used were developed by the Center for Veterinary Medicine Office of Research to identify test kits with comparable selectivity and sensitivity to microscopy and PCR assay, the analytical methods used by the U.S. Food and Drug Administration (FDA). Guidelines were developed for evaluating the selectivity, sensitivity, ruggedness, and specificity of these kits. These guidelines further stated that ruggedness and specificity testing would be performed only after a test passed both the selectivity and sensitivity assessments. Acceptance criteria for determining success were developed using a statistical approach requiring 90% probability of achieving the correct response, within a 95% confidence interval. A minimum detection level of 0.1% bovine meat and bone meal, consistent with the sensitivity of the methods used by the FDA, was required. Selectivity was assessed by testing 60 dairy feed samples that contained no added animal proteins; sensitivity was determined by evaluating 60 samples (per level of fortification) of the same feed that contained 0.025, 0.05, 0.1, 0.25, 0.5, 1, or 2% bovine meat and bone meal. The Reveal test passed the selectivity assessment but failed the sensitivity assessment, detecting only samples fortified at the 2% level and then only 17 to 33% of those samples, when read according to the label directions. The FeedChek test passed the sensitivity assessment but failed the selectivity assessment, with rates for false-positive results ranging from 34 to 38%, depending on the user. The sensitivity of the Reveal test was affected by the concentration of trace minerals present in the feed; concentrations toward the high end of the normal range prevented the detection of true positive feed samples containing bovine meat and bone meal. Better sensitivity assessments were obtained when lamb meal was used either alone or in combination with bovine meat and bone meal. The FeedChek test was not affected by the concentration of trace minerals or by the type of animal meal used. These results indicate that neither of the two tests is adequate for routine regulatory use.     

Social skills and social anxiety: Are different laboratories measuring the same constructs?

Examined the generalizability of social-skills and social-anxiety global ratings made by judges trained in 6 experimental laboratories. Stimulus material consisted of videotapes of 20 psychiatric patients and a control sample of 20 National Guardsmen interacting in 2 types of social simulation typically employed in social-skills assessment: brief role plays and more extended interactions. Moderate degrees of generalizability across laboratories were found for the social-skills and social-anxiety ratings based on the brief role plays. For the more extended interaction, moderate generalizability was obtained for anxiety ratings, with some differences found among laboratories for the skills ratings. Results are viewed as encouraging, since numerous mitigating factors worked against establishing strong generalizability across laboratories. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inability to detect Chlamyodomonas microtubule assembly in vitro: possible implications to the in vivo regulation of microtubule assembly

It has been demonstrated that the in vitro assembly of microtubules from Chlamydomonas preparations does not occur under a wide range of conditions, including those efficacious for mammalian brain tubulin. This incompetence of Chlamydomonas extracts to form microtubules is independent of the tubulin concentration, the presence of added nucleotides or an added seed, temperature, or the concentration of divalent cation. However, an amorphous aggregate was observed under certain conditions, who composition was mainly tubulin. The in vitro reassembly of microtubules in gerbil brain extracts is inhibited by Chlamydomonas preparations. Fractionation of the Chlamydomonas extracts by column chromatography suggests that the inhibitory component is Chlamydomonas tubulin itself. The mechanism of this inhibition is unknown, but reassembly experiments indicate that the 2 types of tubulins cannot copolymerize. We suggest that the Chlamydomonas tubulin, derived from a cytoplasmic pool, requires to be activated prior to its in vivo polymerization into microtubules.