The power transfer and frequency detuning in a gyrotron

A rigorous small-signal theory of the power transfer and the associated complex frequency shift of a gyrotron oscillator is developed. Experimental results taken from a 28 GHz gyrotron operating in the TE₀₂ mode, (measurements made at UKAEA, Culham Laboratory) and theoretical results on the frequency detuning are compared. It is seen that the frequency detuning increases as the frequency of the electric field approaches that of the cyclotron frequency. The imaginary component of the theoretical complex frequency detuning is shown to indicate the region of operation of the device and this is also compared with that obtained experimentally.     

Rheological Studies of Water-Soluble (1–3),(1–4)-β-D-Glucans from Milling Fractions of Oat

We studied the rheological properties of water-soluble, mixed-linkage β-glucans of high purity (88–99.5%) isolated from oats. Comparing the β-glucan fractions at the same concentration (1.3 mg/g) the mean value of the bran fraction viscosities was larger (by 5X) than the mean viscosity of endosperm fractions. Both mean values had a relative standard deviation of ～20%. Heat treatment of oats did not alter the viscous properties of the extracted β-glucans. Activation energies for the bran fraction at two shear rates were E_r=5.81= 42 kJ/mole and E_r=581= 17 kJ/mole. The variation in G′and G′ with frequency for the β-glucan from bran fractions could be qualitatively described by a superposition of two single Maxwell models with widely different relaxation time. These data can help predict potential processing effects on such fractions incorporated as food components.     

SEQUENTIAL PARTITION DETECTORS

Abstract

In this paper the theory of fixed sample nonparametric m-interval partition detectors is extended to include sequential operation. A formulation for sequential m-interval partition detector is given which requires knowledge of only (m ? 1) quantiles under a Lehmann alternative and, in addition, the slope of the distribution at these quantiles under a shift of the mean alternative. A theorem is proven that permits the use of Fisher's information as a bound on performance and assures the existence of a locally most powerful sequential partition detector. In addition, a reduced partition space concept is introduced to combat impulsive noise interference.     

An agile manufacturing workcell design

This paper introduces a design for agile manufacturing worked Is intended for light mechanical assembly of products made from similar components (i.e., parts families). We define agile manufacturing as the ability to accomplish rapid changeover from the assembly of one product to the assembly of a different product. Rapid hardware changeover is made possible through the use of robots, flexible part feeders, modular grippers, and modular assembly hardware. The division of assembly, feeding, and unloading tasks between multiple robots is examined with prioritization based upon assembly time. Rapid software changeover will be facilitated by the use of a real-time, object-oriented software environment utilizing graphical simulations for off-line software development. An innovative dual VMEbus controller architecture permits an open software environment while accommodating the closed nature of most commercial robot controllers. These agile features permit new products to be introduced with minimal downtime and system reconfiguration.     

Influence of Freezing and Thawing on the Egg Vitelline Membrane

The original method finalized for this study was a direct comparison of the isotheimic dehydration rate between two membrane samples, one subjected to a freezing-thawing cycle, the other being untreated control. Freezing entailed irreversible modifications in the properties of the vitelline membrane of the hen's egg as indicated by a significant increase in the water absorption capacity; an accelerated drying rate; and a marked decrease in the water retention capacity. Through this method, the cryoprotective action of glycerol at the membrane level was also demonstrated.     

Energy of Grain Boundaries in Halite

Relative grain boundary energy measurements were made by the tracrystal method for [100] tilt boundaries in NaCl. The dependence of boundary energy on grain misorientation was similar to that in metals; however, the presence of significant torque term effects, i.e. dependence of the boundary energy on boundary orientation, is indicated. A method of measuring the relative magnitudes of the torque terms by applying a driving force to boundaries in bi-crystals is described.     

Neutron Scattering Studies of Vitrified Radioactive Waste

The structure of a borosilicate glass containing simulated nuclear waste on a distance scale up to several tens of nanometers was investigated using neutron scattering techniques. Comparison of samples with and without waste suggests that the nature of the basic network of SiO₄ tetrahedra and BO₃ triangles is largely unchanged by addition of the waste. The real-space correlation function for the glass plus waste has clear features at distances below 0.5 nm, which can be attributed to the above network building units. Study of a partially devitrified sample shows diffraction effects due to polycrystalline and vitreous phases. Vitreous and partially devitrified glass containing waste produced a significant amount of small-angle scattering corresponding to regions of inhomogeneity which are 10 nm and larger.