NIST is currently investigating the design of a second-generation cesium-fountain primary frequency standard. The design goals of this standard include an ultimate frequency inaccuracy of δf/f < 10 and achievable stability better than σy(τ) < 10/τ. This standard is expected to eventually replace NIST-F1, the current U.S. primary frequency standard [1]. In the context of reaching frequency uncer...

The ability of plants to absorb ions selectively is a major reason for the preference for chemical rather than physical theories of ion uptake (11), yet in spite of this, comparatively little attention has been paid to this property. Thus far, selectivity between alkali cations has been examined in excised barley roots (6) in beet discs (12) and in whole plants (1,4). In recent years the relati...

Neutron diffraction with isotopic substitution has been used to investigate the liquid structures of propylene carbonate and glycerol carbonate. C-HO[double bond, length as m-dash]C hydrogen-bonding motifs dominate the local structure of propylene carbonate, giving rise to the formation of head-to-tail correlated chains of molecules. In contrast, glycerol carbonate exhibits a more disordered st...

We report on the simultaneous observation, by delayed Bragg diffraction, of four- and six-wave mixing processes in a coherently prepared atomic ensemble consisting of cold cesium atoms. For each diffracted order, we observe different temporal pulse shapes and dependencies with the intensities of the exciting fields, evidencing the different mechanisms involved in each process. The various obser...

Our previous research has demonstrated that dissolved organic matter (DOM) influences calcium carbonate mineral formation in surface and ground water. To better understand DOM mediation of carbonate precipitation and DOM co-precipitation and/or incorporation with carbonate minerals, we characterized the content and speciation of DOM in carbonate minerals and in the lake water of Pyramid Lake, N...

The Knoevenagel condensation between aromatic aldehydes and malononitrile, ethyl cyanoacetate or malonic acid with hydroxyapatite supported caesium carbonate in water is described. HAP-Cs₂CO₃ was found to be a highly active, stable and recyclable catalyst under the reaction conditions.

We report the observation of a three-body recombination resonance in an ultracold gas of cesium atoms at a very large negative value of the s-wave scattering length. The resonance is identified as the second triatomic Efimov resonance, which corresponds to the situation where the first excited Efimov state appears at the threshold of three free atoms. This observation, together with a finite-te...

The complexation of Cm(III) with transferrin is investigated in the pH range from 3.5 to 11.0 in the absence of carbonate and at c(carbonate)tot = 25 mM. In the absence of carbonate two Cm(III) transferrin species I and II are formed depending on pH. An increase of the total carbonate concentration favors the formation of the Cm(III) transferrin species II with Cm(III) bound at the Fe(III) bind...

We report on the storage of orbital angular momenta (OAM) of light via the phenomenon of coherent population oscillation (CPO) in cold cesium atoms. The experiment is performed using a delayed four wave mixing configuration, where the transverse optical information of a probe field carrying OAM associated with its azimuthal phase dependence is stored in the CPO of Zeeman sublevels of the hyperf...