Dynamic formation of a hot field reversed configuration with improved confinement by supersonic merging of two colliding high-ß compact toroids.

A hot stable field-reversed configuration (FRC) has been produced in the C-2 experiment by colliding and merging two high-ß plasmoids preformed by the dynamic version of field-reversed θ-pinch technology. The merging process exhibits the highest poloidal flux amplification obtained in a magnetic confinement system (over tenfold increase). Most of the kinetic energy is converted into thermal energy with total temperature (T{i}+T{e}) exceeding 0.5 keV. The final FRC state exhibits a record FRC lifetime with flux confinement approaching classical values. These findings should have significant implications for fusion research and the physics of magnetic reconnection.

Degradation of 2,4,5-trichlorophenol and 2,3,5,6-tetrachlorophenol by combining pulse electric discharge with bioremediation.

Degradation of 2,4,5-trichlorophenol (2,4,5-TCP) and 2,3,5,6-tetrachlorophenol (TeCP) was studied using a two-stage approach that utilized efficient pulse electric discharge (PED) followed by biological degradation with a consortium from acclimated return activated sludge. The chlorinated phenols were treated in the PED reactor as an aerosol at a voltage of 55-60 kV, a frequency of 385 Hz, a current of 50-60, and with a 200-ns pulse. As determined by gas chromatography and mass spectrometry (GC/MS), the first stage converted 500 ppm 2,4,5-TCP to 163 ppm 2,4,5-TCP and dimethyldecene, dichloronaphthalenol, octyl acetate, and silyl esters. The total carbon content of 2,4,5-TCP after PED treatment was determined to be 228 +/- 35 ppm. The remaining 2,4,5-TCP and the products formed were then mineralized by the acclimated activated sludge in shake flasks; the initial rate of degradation of 2,4,5-TCP was calculated to be 5 nmol min-1 mg protein-1 at 163 ppm initial concentration (three orders of magnitude higher than the only rate found in the literature). By combining the two techniques, a synergistic effect (2.3-fold increase in the concentration of 2,4,5-TCP degraded and 3.3-fold increase in total carbon degraded) was observed, in that bacteria without any treatment degraded a maximum of 70 ppm, 2,4,5-TCP but after PED treatment 163 ppm 2,4,5-TCP was degraded. TeCP was also mineralized by the acclimated activated sludge after treatment with PED. This two-stage approach was also evaluated using a continuous 1-l fluidized-bed reactor.

Degradation of perchloroethylene and dichlorophenol by pulsed-electric discharge and bioremediation

Pulsed electric discharge (PED) and bioremediation were combined to create a novel two-stage system which dechlorinates the halogenated pollutants, 2,4-dichlorophenol and perchloroethylene, with repetitive (0.1-1 kHz), short pulse ( approximately 100 ns), low voltage (40-80 kV) discharges and then mineralizes the less chlorinated products with aerobic bacteria. A 6.1 mM aqueous dichlorophenol sample was cycled through the PED reactor (60 kV of applied pulsed voltage and 300 Hz) 6 times, resulting in the release of 55% of the initial dichlorophenol chloride ions (1 mM Cl- removed each cycle). The respective average specific efficiency is 0.4-0.6 keV/(Cl- molecule). Pseudomonas mendocina KR1, which grows in minimal medium supplemented with phenol but not with dichlorophenol, increased in cell density in all cultures supplemented with the PED-treated DCP samples and yielded a maximum of two-fold additional Cl- released compared to the PED-related alone. The number of PED-treatment cycles, voltage, and frequency were also varied, showing that both cell densities and overall dichlorophenol dechlorination were highly dependent upon the number of PED-treatment cycles, rather than the tested voltages and frequencies. Using this two-stage treatment system, PED released 31% of the initial chloride ions from dichlorophenol (after three cycles at 40-45 kV and 1.2 kHz) while P. mendocina KR1 in the second stage increased dechlorination to 90%. These results were corroborated by the 35% additional chloride release found with activated sludge cultures. Perchloroethylene (0.6 mM) was similarly treated in a first-stage PED reactor (80% chloride removal after four cycles) followed by biodegradation of the dechlorinated products with a recombinant toluene o-monooxygenase-expressing Pseudomonas fluorescens strain. Gas chromatographic analysis showed that the PED reactor created less-chlorinated byproducts (i.e., trichloroethylene) that were removed (74%) upon exposure to the recombinant bacterium. Copyright 1998 John Wiley & Sons, Inc.

[Why is the eye round?]. / Pochemu glaz kruglyi?.

By an unsophisticated experiment, published data on the anatomy of the eye, wave theory of light, and the laws of geometrical optics the author tries to prove that a spherical concave screen is the optimal variant of a screen on which spherical wave front is projected, formed by a single lens. The shape of the wave front and of the concave screen are in complete agreement. Such optical imperfections as the field curvature, distortion, coma (partially), and astigmatism of the oblique light beams are compensated for. These optical drawbacks are undetectable on a concave screen, and hence they are proposed to be the shortcomings of a flat screen. The author compares this to a spherical shape of the eye, the posterior wall of which represents a concave screen, an indisputable fact, and assumes that the before-named optic imperfections are completely compensated for in human eye due to concavity of the posterior optic wall. Based on the anatomy and practical results of using aspherical refracting surfaces in artificial optic devices, the author draws a parallel with the anatomical structures of the eye possessing aspherical refracting surfaces in order to demonstrate that higher and lower-order spherical aberrations (Zeidel's aberrations) are fully compensated for in human eye, as are the position and enlargement chromatism. Analysis of published data permitted the author to assert that the eye of man is characterized by a method for compensation of spherical aberrations, which has no analogs in man-made practice. Hence, the Nature has imparted the eye with such a collection of compact, universal, and highly effective methods for compensation of optic imperfections, which is not to be found in any of the man-made devices of today.

[The Pau phenomenon and complex movements of hyaloid in aphakic eyes]. / O fenomene Pau i slozhnykh dvizheniiakh gialoida v afakichnykh glazakh.

The author analyzed complex movements of the hyaloid at the height of the ciliary muscle contraction in 121 aphakic eyes. He came to a conclusion that hyaloid dislocation is an active process realized by the ciliary muscle in the course of its contraction. Hyaloid and the vascular coating, on the one hand, and the ciliary muscle, on the other, were shown to be antagonists. Atropine in instillations paralysed the whole muscle, and it was impossible then to detect the predominance of Brücke's muscle over Muller's one. Adrenalin instillations after Gredle or subconjunctivally did not stimulate the contractions of Brücke's muscle, but only those of the vascular coating, for the effects of adrenalin on vascular walls are well known. As for the double innervation of accommodation, it is a fact undeniable, which only confirms that sympathetic innervation performs a trophic function in any tissue, and in the ciliary muscle as well as anywhere else.

[Accommodation]. / K voprosu ob akkomodatsii.

Based on the literature data and his own findings the author makes an attempt to specify the accommodation mechanism, particularly hyaloid effect on the lens in the course of accommodation. It is believed, and the author presents experimental data in favor of this assumption, that in youth the lens and hyaloid represent a single optic complex. The lens sealed in the cup-like depression of the vitreous body cannot be mobile in relation to the hyaloid and cannot acquire a more convex shape by itself at the height of accommodation. Moreover, experiments have proved that at the height of accommodation, according to many authors' data, the posterior pole of the lens is shifted towards the hyaloid to a distance of 0.16 to 0.27 mm, which the lens surely cannot do by itself. The hyaloid making rotatory movements at the height of accommodation, it is evident that the lens in this case passively follows the hyaloid and acquires an aspherical shape only under its effect. The ciliary belt plays but a secondary role in this process, being just a buffer.