COEXISTENCE OF FERROMAGNETISM AND HIGH-TEMPERATURE SUPERCONDUCTIVITY IN Dy-DOPED BiPbSrCaCuO

Ferromagnetism was found to coexist with superconductivity in Dy-doped BiPbSrCaCuO-2212 single crystals up to the superconducting critical temperature Tc ~ 80 K . Several experimental tests indicated that the phenomenon is intrinsic to the entire specimen rather than due to separate phases or to isolated impurities.

Paolia vetusta Smith, 1871 (Insecta: Protorthoptera), from the Mansfield Formation (Pennsylvanian), Indiana

Paolia vetusta Smith, 1871a, from the Hindostan whetstone beds of Indiana (Namurian), thought to have been lost since 1918, has been found and currently is housed at Hanover College, Hanover, Indiana. Paolia vetusta is illustrated photographically for the first time. The major character difference between Smith's (1871a) figure and the actual specimen is the lack in the latter of an extensive archedictyon extending over the entire specimen. Currently, the family Paoliidae is defined as having Sc terminating on R. Paolia vetusta clearly shows Sc terminating on C. Therefore, the Sc terminus should have no taxonomic significance at the family level.

Heating and quenching of fossils

Rapid temperature change can be used to free fossils from some types of rock. Using this method, rocks are alternately heated over a gas burner and quenched in cold running water. The method is especially useful for obtaining specimens of small species (5mm–7mm), but whole specimens up to 50mm long have been released from rock. Heating and quenching should be tried on those limestones that break through both fossils and matrix when the rock is struck with a hammer or broken with a rock splitter. In such limestones, it is often difficult and time consuming to remove specimens using needles and grinding wheels (Sohl, this volume, chapter 19). Many more specimens can be obtained for study more rapidly by heating and quenching such rocks than can be obtained by mechanical preparation. In most instances, only one side of a specimen is exposed when limestone is split mechanically, and the opposite side of the specimen adheres tightly to the remaining rock. In such cases, heating and quenching can free the entire specimen of all rock.

A novel technique for quantitative autoradiography of labeled histological specimens.

A novel quantitative method is described that makes it possible to routinely and accurately quantify contact autoradiographs of tissue sections in terms of actual amounts of radioactivity per square millimeter. Such determinations can either be made on the entire specimen or on any selected area of arbitrary shape that might correspond to a particular histological structure. This method utilizes the tissue specimens themselves as internal standards and requires the availability of a computerized image analyzer.

Specimen Charging: Effect on Beam Voltage

Users of electron column instruments have long known of the mischievous results of charging of non-conductive specimens. The consequences can range from slight image degradation to complete chaos, and in the case of reflection electron diffraction sometimes produces images of expanding and collapsing bubbles instead of steady concentric rings.The cure for this trouble has usually been to vacuum coat the specimen with a conductive layer: carbon, gold, and to a limited degree, fine graphite spray-coated on the surface (1,2). Charge neutralizing with alpha-emitting isotopes or electron guns where a general spray of electrons with a few hundred volts of energy is aimed at the entire specimen also have been used to allow incipient charging to leak off to ground.

The Meed for Experimentally Determined X-ray Elastic Constants

In order to convert residual strains measured by x-ray diffraction techniques into residual stresses, appropriate x-ray elastic constants have to be measured. Since these x-ray elastic constants may depend on the metallurgical state, deformation, and entire specimen history, errors in stress values may result if the constants are not measured for representative material states. In the present work, it is shown that in same cases these errors may be large.

1. On the Anatomy of a new species of Polyodon, the Polyodon Gladius of Martens, taken from the river Yang-tsze-Kiang, 450 miles above Woosung. Part II., being its Nervous and Muscular Systems

The author showed to the Society a small entire specimen of the P. gladius, and next described, from a larger opened and dissected one, and from part of an adult fish, the spinal cord, the brain, the organs of the senses, and other parts of its nervous system. He illustrated his remarks by exhibiting four large drawings and nine smaller ones, including six microscopic views, explanatory of his description of the structure and disposition of the spino-cerebral axis, the encephalon as viewed from above and below, the ramifications of the encephalic nerves, and more particularly the structures subserving the senses of smell, sight, and hearing.