Phase-dependent decoherence of optical transitions in Pr3+:LaF3 in the presence of a driving field

The decoherence times of orthogonally phased components of the optical transition dipole moment in a two-level system have been observed to differ by an order of magnitude. This phase anisotropy is observed in coherent transient experiments where an optical driving field is present during extended periods of decoherence. The decoherence time of the component of the dipole moment in phase with the driving field is extended compared to T_2, obtained from two-pulse photon echoes, in analogy with the spin locking technique of NMR.Comment: 5 pages, 2 figures; replaced with published versio

Demonstration of conditional quantum phase shift between ions in a solid

Due to their potential for long coherence times, dopant ions have long been considered promising candidates for scalable solid state quantum computing. However, the demonstration of two qubit operation has proven to be problematic, largely due to the difficulty of addressing closely spaced ions. Here we use optically active ions and optical frequency addressing to demonstrate a conditional phase shift between two qubits

Genesis, Pathways, and Terminations of Intense Global Water Vapor Transport in Association with Large-Scale Climate Patterns

The CONNected objECT (CONNECT) algorithm is applied to global Integrated Water Vapor Transport data from the NASA's Modern-Era Retrospective Analysis for Research and Applications – Version 2 reanalysis product for the period of 1980 to 2016. The algorithm generates life-cycle records in time and space evolving strong vapor transport events. We show five regions, located in the midlatitudes, where events typically exist (off the coast of the southeast United States, eastern China, eastern South America, off the southern tip of South Africa, and in the southeastern Pacific Ocean). Global statistics show distinct genesis and termination regions and global seasonal peak frequency during Northern Hemisphere late fall/winter and Southern Hemisphere winter. In addition, the event frequency and geographical location are shown to be modulated by the Arctic Oscillation, Pacific North American Pattern, and the quasi-biennial oscillation. Moreover, a positive linear trend in the annual number of objects is reported, increasing by 3.58 objects year-over-year

Frontal Sinus Mucocoele An unusual clinico-radiological presentation

A case of frontal sinus mucocoele is presented with atypical radiological findings. The mucocoele was removed via an osteoplastic flap procedure

Photon Echoes Produced by Switching Electric Fields

We demonstrate photon echoes in Eu$^{3+}$:Y$_{2}$SiO$_{5}$ by controlling the inhomogeneous broadening of the Eu$^{3+}$ $^{7}$F$_{0}\leftrightarrow^{5}$D$_{0}$ optical transition. This transition has a linear Stark shift and we induce inhomogeneous broadening by applying an external electric field gradient. After optical excitation, reversing the polarity of the field rephases the ensemble, resulting in a photon echo. This is the first demonstration of such a photon echo and its application as a quantum memory is discussed.Comment: improved introduction, including theoretical outline of the relvant quantum memory proposa

A Maitland–Japp inspired synthesis of dihydropyran-4-ones and their stereoselective conversion to functionalised tetrahydropyran-4-ones

The Maitland–Japp reaction has been extended to the synthesis of highly functionalised dihydropyran-4-ones. These dihydropyran-4-ones can in turn be converted stereoselectively into tetrahydropyran-4-ones with tertiary and quaternary stereocentres via the one-pot addition of hydride or carbon nucleophiles and trapping with carbon electrophiles. The utility of this method is demonstrated by providing access to the functionalised tetrahydropyran units present in a component of the Civet fragrance and the anticancer polyketide lasonolide A

Maintenance cost implications of utilizing bathroom modules manufactured offsite

Though the benefits from using offsite technologies have been rehearsed, their uptake within the UK construction industry is slow. A critical barrier is the lack of cost data of using such technology. Another is the unsubstantiated perception that maintenance of offsite solutions is difficult and expensive. But, yet again, there appears to be no data publicly available on this topic. This knowledge gap is addressed by presenting the cost data of maintaining offsite and insitu bathrooms for student accommodation. The records of 732 maintenance jobs were investigated. These jobs span three years for 398 bathrooms, including precast concrete modules, Glass Reinforced Polyester (GRP) modules and insitu bathrooms. The results suggest that GRP modules required the lowest maintenance costs whilst insitu bathrooms were significantly more expensive to maintain. For offsite modules, drainage, toilets, vents and sink were identified as the main problematic areas for maintenance. The maintenance of insitu bathrooms was more complex and involved a wider range of problematic areas. The design imposed significant effects on the long-term cost of offsite bathrooms. Aspirations of clients need to be fully understood and integrated into design. The findings should facilitate the design decision-making of using offsite bathrooms for residential buildings

Freezing properties of alkenyl succinic anhydrides derived from linear isomerised olefins

Alkenyl succinic anhydrides are important specialty chemicals that are used in the paper, oilfield and fuel additives industries. In this paper we investigate the link between the physical properties of alkenyl succinic anhydrides and the identities of their linear alkyl olefin precursors. We describe a straightforward GC analysis of olefin isomer distributions and show that these correlate well with the freezing temperatures of the subsequent alkenyl succinic anhydride products. This allows the identification of olefin isomer profiles that are required to give the desired physical properties in the alkenyl succinic anhydrides; it also provides a method to predict the freezing temperatures of alkenyl succinic anhydrides synthesised from a particular supply of olefin