Nowadays atomic optical lattice clocks can perform frequency measurements with a fractional uncertainty at the 10 level in few hours of measurement, outperforming the best caesium (Cs) standards operated in the world. Since the definition of the unit of time is based on Cs, a worldwide debate about the need to promote the redefinition of the second on a optical reference is under-way. At INRIM ...

Removal of potassium from Hydra culture medium produces a decrease in intracellular potassium and a parallel decrease in asexual growth rate. Rubidium and caesium are ineffective as substitutes for potassium in the maintenance of growth rate. Increases in intracellular potassium parallel increases in growth rate up to a level somewhat below the normal steady-state level of intracellular potassi...

The crystal structure of caesium di-hydrogen citrate, Cs+·H2C6H5O7-, has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The coordination polyhedra of the nine-coordinate Cs+ cations share edges to form chains along the a-axis. These chains are linked by corners along the c-axis. The un-ionized carb-oxy-lic acid groups f...

1. A soluble extract of bovine heart valves was obtained after the tissue had been pulverized at liquid-nitrogen temperatures in a mill. 2. Hyaluronic acid was isolated from the crude extract by sedimentation equilibrium in a caesium chloride density gradient (Franek & Dunstone, 1966). 3. Analysis of the product indicated that it contained 15% of protein and the molar ratio of glucuronic acid t...

AIMS To develop a genome based DNA fingerprinting system for Aspergillus fumigatus mould. METHODS DNA was extracted from 21 isolates obtained from eight patients with an aspergilloma. This was with a freeze-dried mycelial extract fragmented in liquid nitrogen. DNA was subsequently purified by phenol-chloroform extraction followed by ultracentrifugation on a caesium chloride gradient. The DNA ...

We present experimental observations of diffusion resonances for the quantum kicked rotor with weak decoherence. Cold caesium atoms are subject to a pulsed standing wave of near-resonant light, with spontaneous emission providing environmental coupling. The mean energy as a function of the pulse period is determined during the late-time diffusion regime for a constant probability of spontaneous...

Caesium chromium(III) diarsenate(V), CsCrAs2O7, was prepared by solid-state reactions. The title structure consists of isolated CrO6 octa-hedra and As2O7 diarsenate groups, sharing corners to build up a three-dimensional [CrAs2O7](-) anionic framework. In this framework, channels extending parallel to [001] are present in which the ten-coordinate Cs(+) ions reside. CsCrAs2O7 is isotypic with th...

In the structure of the title complex, [Cs(C8H4Cl3O2)(H2O)] n , the caesium salt of the commercial herbicide fenac [(2,3,6-tri-chloro-phen-yl)acetic acid], the irregular eight-coordination about Cs(+) comprises a bidentate O:Cl-chelate inter-action involving a carboxyl-ate-O atom and an ortho-related ring-substituted Cl atom, which is also bridging, a triple-bridging carboxyl-ate-O atom and a b...

The evaluation procedure of a new laser-cooled caesium fountain primary frequency standard developed at the National Institute of Standards and Technology (NIST) is described. The new standard, NIST-F1, is described in some detail and typical operational parameters are discussed. Systematic frequency biases for which corrections are made – second-order Zeeman shift, black-body radiation shift, ...

2014 The 6S1/2 8S1/2 caesium transition is excited in a Stark field, with a pulsed narrow-band nitrogenpumped dye-laser. It is detected by monitoring the fluorescence light emitted in the 8S1/2 6P1/2 decay. The scalarto-vector off-diagonal polarizability ratio is obtained : 03B1/03B2 = 4.8 ± 0.5. The M1 amplitude is observed through the electronic polarization created in 8S1/2 by its interferen...