On the Coexistence in RuSr2GdCu2O8 of Superconductivity and Ferromagnetism

We review the reasons that make superconductivity unlikely to arise in a ferromagnet. Then, in light of the report by Tallon and collaborators that RuSr2GdCu2O8 becomes superconducting at approximately 35 K which is well below the Curie temperature of 132 K, we consider whether the objections really apply to this compound. Our considerations are supported by local spin density calculations for this compound, which indeed indicate a ferromagnetic RuO2 layer. The Ru moment resides in t_2g orbitals but is characteristic of itinerant magnetism (and is sensitive to choice of exchange-correlation potential and to the atomic positions). Based on the small exchange splitting that is induced in the Cu-O layers, the system seems capable of supporting singlet superconductivity an FFLO-type order parameter and possibly a pi-phase alternation between layers. If instead the pairing is triplet in the RuO2 layers, it can be distinguished by a spin-polarized supercurrent. Either type of superconductivity seems to imply a spontaneous vortex phase if the magnetization is rotated out of the plane.Comment: 3 revtex pages, 2 embedded figures. In press, Proc. HTS99 Conf., Miami, 199

Precise timing correlation in telemetry recording and processing systems

Independent PCM telemetry data signals received from missiles must be correlated to within + or - 100 microseconds for comparison with radar data. Tests have been conducted to determine RF antenna receiving system delays; delays associated with wideband analog tape recorders used in the recording, dubbing and repdocuing processes; and uncertainties associated with computer processed time tag data. Several methods used in the recording of timing are evaluated. Through the application of a special time tagging technique, the cumulative timing bias from all sources is determined and the bias removed from final data. Conclusions show that relative time differences in receiving, recording, playback and processing of two telemetry links can be accomplished with a + or - 4 microseconds accuracy. In addition, the absolute time tag error (with respect to UTC) can be reduced to less than 15 microseconds. This investigation is believed to be the first attempt to identify the individual error contributions within the telemetry system and to describe the methods of error reduction within the telemetry system and to describe the methods of error reduction and correction

Grapes for home and market

Citation: Pickett, Luther B. Grapes for home and market. Senior thesis, Kansas State Agricultural College, 1905.Morse Department of Special CollectionsIntroduction: The date at which man commenced using the grape is unknown. The first authentic record of its use was made at a very ancient time, but the fruit was then extensively cultivated, being used in primitive wine making. However, the history of grape culture, so far as it affects the people of the United States, is a record of recent date. When the early settlers first came to America they found wild grape vines growing in such abundance that they named the country Vineland, and sent back to the old country hyperbolical reports about the wonderful fertility of the newly–discovered continent. In the last two hundred years, and especially in the last fifty years, unparalleled progress has been made in viticulture. Taking the native wild grapes experimenters and growers have produced innumerable varieties of large size and excellent quality. Success has been attained through the use of the native species alone, for the European species were found to be too tender to be grown with profit in any of the States of the Union except California. The grape is one of the best of fruits and is quite easily grown, yet with it as with the majority of other fruits, there is an insignificant number of growers compared with the multitude of people who might reap the benefits of its use. It grows in almost every variety of soil and practically every person has sufficient knowledge and skill to grow it with success. Every farmer has it within his power to grow grapes and should grow at least a few vines to supply his own table with the fruit. If a little care is taken in selecting varieties and in caring for the fruit, one may have it won the table three months out of every year

Electron Confinement, Orbital Ordering, and Orbital Moments in d0d^0-d1d^1 Oxide Heterostructures

The (SrTiO$_3$)$_m$/(SrVO$_3$)$_n$ $d^0-d^1$ multilayer system is studied with first principles methods through the observed insulator-to-metal transition with increasing thickness of the SrVO$_3$ layer. When correlation effects with reasonable magnitude are included, crystal field splittings from the structural relaxations together with spin-orbit coupling (SOC) determines the behavior of the electronic and magnetic structures. These confined slabs of SrVO$_3$ prefer $Q_{orb}$=($\pi,\pi$) orbital ordering of $\ell_z = 0$ and $\ell_z = -1$ ($j_z=-1/2$) orbitals within the plane, accompanied by $Q_{spin}$=(0,0) spin order (ferromagnetic alignment). The result is a SOC-driven ferromagnetic Mott insulator. The orbital moment of 0.75 $\mu_B$ strongly compensates the spin moment on the $\ell_z = -1$ sublattice. The insulator-metal transition for $n = 1 \to 5$ (occurring between $n$=4 and $n$=5) is reproduced. Unlike in the isoelectronic $d^0-d^1$ TiO$_2$/VO$_2$ (rutile structure) system and in spite of some similarities in orbital ordering, no semi-Dirac point [{\it Phys. Rev. Lett.} {\bf 102}, 166803 (2009)] is encountered, but the insulator-to-metal transition occurs through a different type of unusual phase. For n=5 this system is very near (or at) a unique semimetallic state in which the Fermi energy is topologically determined and the Fermi surface consists of identical electron and hole Fermi circles centered at $k$=0. The dispersion consists of what can be regarded as a continuum of radially-directed Dirac points, forming a "Dirac circle".Comment: 9 pages, 8 figure

The metabolism and localization of glycerol by bovine spermatozoa

The discovery that glycerol would protect spermatozoa during freezing and thawing led to questions concerning its metabolism and mode of action; especially bovine spermatozoa, due to its inflexible cellular membrane. This investigation provides additional information concerning the metabolism and localization of glycerol in the bovine spermatozoa.Digitized from microfilm. Printed single-sided. Blank pages removed from digital copy.Since the discovery that glycerol, a trihydroxy alcohol, would provide protection for spermatozoa during the freezing and thawing process, many questions have arisen concerning its metabolism and mode of action. Most of the recent work, with various types of single cells ans tissues, has shown that the cells are permeated by glycerol and that entry must occur before full protection is afforded. However, the methods employed in the majority of these studies have not proven successful for bovine spermatozoa, possibly due to its extremely inflexible cellular membrane and/or the slow rate at which glycerol enters the cell. The majority of the information concerning glycerol entry into bovine spermatozoa bas been supplied by metabolic studies. These studies have indicated that glycerol is metabolized by spermatozoa both anaerobically and aerobically in quantities too large to attribute the action to extracellular enzymes alone. However, relatively little information is available concerning the intracellular loci of glycerol action. Thus, this investigation was undertaken to provide additional information concerning the metabolism and localization of glycerol in the bovine spermatozoa.Introduction -- Review of literature -- Materials and methods -- Observations and results -- Discussion -- Summary and conclusions

Alien Registration- Pickett, Mary B. (Greenville, Piscataquis County)

https://digitalmaine.com/alien_docs/8432/thumbnail.jp

Hormones Speed Roots

Tests at Iowa Station show that certain chemicals greatly aid in root formation