Apparent activation energy of structural relaxation for Se70Te30 glass

Differential scanning calorimetry and dc conductivity measurements were used to study structural relaxation of Se₇₀Te₃₀ glass. A single set of Tool-Narayanaswamy-Moynihan (TNM) parameters was obtained from the curve-fitting procedure. The value of apparent activation energy Δh∗ was further confirmed by two non-fitting techniques. Results of the Δh∗ evaluation from the T_g dependence on cooling rate are discussed in terms of how the T_f determination might be influenced by the material’s structure type and by the interference of the crystallization process.     

ORLANDO - Oak Ridge large neutrino detector

We discuss a proposal for construction of an Oak Ridge LArge Neutrino DetectOr (ORLANDO) to search for neutrino oscillations at the Spallation Neutron Source (SNS). A 4 MW SNS is proposed to be built at the Oak Ridge National Laboratory with the first stage to be operative around 2006. It will have two target stations, which makes it possible with a single detector to perform a neutrino oscillation search at two different distances. Initial plans for the placement of the detector and the discovery potential of such a detector are discussed.     

Longitudinal magnetoresistance of platinum: The influence of lattice vacancies

The longitudinal magnetoresistance of polycrystalline platinum wires has been measured in magnetic fields up to 45 kOe at liquid helium temperatures. The deviations from Kohler's rule found depend on the concentration of quenched-in vacancies, and are interpreted as due to the contribution of single vacancies in platinum to the small angle scattering of electrons. The small-angle scattering may also be responsible for the linear magnetoresistance of platinum in high magnetic fields.     

Bewertung der in der Emissionsspektrographie verwendeten Photomaterialien

Zusammenfassung Zur Beurteilung von Photomaterial, das zur spektrographischen Analyse mit hoher Nachweisempfindlichkeit bestimmt ist, eignen sich die Parameter L _max und R _max. L _max ist für Verfahren ma\gebend, bei denen man eine hohe absolute Nachweisempfindlichkeit erreichen will, R _max für eine hohe Konzentrationsempfindlichkeit. Es wurden Formeln abgeleitet, nach denen man den Wert dieser Parameter berechnen kann, wenn die Konstanten der Kennlinie , , E ₀und die AbhÄngigkeit der SchwÄrzungsfluktuationen von der SchwÄrzung bekannt sind. Nach dem vorgeschlagenen Verfahren wurden die Eigenschaften von acht Spektralplattensorten verglichen.

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Summary The parameters L _max and R _max are proposed for testing photomaterials used for high sensitivity emission spectrography. For attaining highest absolute sensitivity the materials with high value of L _max are to be applied, for highest concentration sensitivity the value of R _max is decisive. Formulas for these parameters are derived, which are functions of characteristic curve constants , , E ₀of the form of Siedentopfs' equation and of the slope of density fluctuation. According to the method proposed 8 different photomaterials have been tested.