Mössbauer Study of Ceramic Finds from the Galería de las Ofrendas, Chavín de Huántar

Ceramic finds from the Galería de las Ofrendas at Chavín de Huántar and surface finds from the settlement of Chavín were characterised by combining the results of archaeological typology with archaeometric studies using neutron activation analysis, Mössbauer spectroscopy, X-ray diffraction and thin-section microscopy. Sherds from the pyramid Tello are included in the study as representative of local material. The analyses show that the vessels were made from different raw materials and that different firing procedures were used in their production. Sherds of certain styles largely exhibit similar types of Mössbauer patterns and in many instances also have similar element compositions. This supports the archaeological notion that the vessels were brought to Chavín from the provinces, perhaps on the occasion of a festivity.     

Doppler cooling a single Ca+ ion with a violet extended-cavity diode laser

We present a scheme for employing a violet extended-cavity diode laser in experiments with single, trapped ions. For this the grating-stabilised laser is spatially and spectrally filtered and referenced to a Fabry–Pérot cavity. We measure an upper limit to the line width by observing a 305-kHz FWHM beat note with the second harmonic of a titanium sapphire laser. The laser is subsequently used to optically cool a single ⁴⁰Ca⁺ ion close to the Doppler limit. PACS 03.67.Lx; 32.80.Pj; 42.55.Px     

Bestmögliche innere Schalengleichungen für schubweiche Werkstoffe unter Berücksichtigung von Dickenänderungen

Übersicht Konsistente Schalentheorien lassen sich in einer besonders anschaulichen Weise durch lineare Approximation der Erhaltungssätze eines als Multi-Direktor-Körper beschriebenen, dreidimensionalen Kontinuums herleiten. Im vorliegenden Beitrag entstchen auf diesem Wege bestmögliche, in Geschwindigkeiten formulierte innere Schalengleichungen für beliebig große Deformationen und willkürliche, in eine Leistungsaussage einpaßbare Materialgesetze. Dabei finden Schub- und Querdeformationen Berücksichtigung. Der optimale Charakter der Schalentheorie mit gleichen Unschärfen in allen Einzelbeziehungen wird durch den Herleitungsgang sichergestellt und durch Einschrankungen mittels lokaler Tensornormen bewiesen.

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Best interior shell equations including transverse shear deformations and thickness changes

Summary Consistent shell theories can be derived in a particular correct manner by linear approximation of conservation laws of a three-dimensional continuum, described as a multi-director-body. In the present paper best interior shell equations-formulated in velocities—are developed, valid for arbitrarily large deformations and rather optional material laws, incorporating shear distorsions and thickness changes. The optimal character of the theory is guaranteed by the derivation process and proven by bounding techniques using tensor norms.