Long-Range Order in Electronic Transport through Disordered Metal Films

Ultracold atom magnetic field microscopy enables the probing of current flow patterns in planar structures with unprecedented sensitivity. In polycrystalline metal (gold) films we observe long-range correlations forming organized patterns oriented at +/- 45 deg relative to the mean current flow, even at room temperature and at length scales orders of magnitude larger than the diffusion length or the grain size. The preference to form patterns at these angles is a direct consequence of universal scattering properties at defects. The observed amplitude of the current direction fluctuations scales inversely to that expected from the relative thickness variations, the grain size and the defect concentration, all determined independently by standard methods. This indicates that ultracold atom magnetometry enables new insight into the interplay between disorder and transport

Accountability and music: accounting, emotions and responses to the 1913 concert for Giuseppe Verdi

Purpose: This study aims to explore the engagement between accounting and music in the social and relational construction of accountability. The authors conceive this construction as a dynamic and recursive interplay between the giving of different accounts and the responses that these accounts provoke. The authors investigate the emotional dimension of this interplay, as it is also triggered by music, feeding back into how accountability is constructed and evolves over time. Design/methodology/approach: This study relies upon a historical analysis of archival and secondary sources about the main music concert organized in 1913 by the founder of “Accademia Chigiana”, one of the leading music academies in Italy. The concert celebrated the first centenary of the birth of Giuseppe Verdi, a worldwide famous Italian music composer, and icon of Italian national sentiment. Findings: This study shows that music and accounting were profoundly intertwined in the social and relational construction of accountability for the 1913 concert. Accountability evolved through different accounts, also linked to music, and the complex emotional reactions these accounts provoked in the audiences, citizens, media and institutions, leading to always further responses and accounts in the ongoing construction of accountability. Originality/value: This study extends prior literature on the chameleonic nature of accountability, as well as on its relational and emotional dimensions. The study shows that accountability is relationally constructed and evolves over time through the giving of accounts and the emotional reaction they provoke from others, feeding into further responses and accounts of the accountable subject. The authors show how the chameleonic nature of accountability permeates not only the accounts and the relations of accountability but also the subjects giving and demanding the accounts: these subjects change as chameleons through their interactions and emotions, feeding into the dynamic construction of accountability. The authors also show how arts, like music, can participate in the chameleonic nature of accountability and of its subjects, precisely by engaging with their emotional reactions and responses

Designing potentials by sculpturing wires

Magnetic trapping potentials for atoms on atom chips are determined by the current flow in the chip wires. By modifying the shape of the conductor we can realize specialized current flow patterns and therefore micro-design the trapping potentials. We have demonstrated this by nano-machining an atom chip using the focused ion beam technique. We built a trap, a barrier and using a BEC as a probe we showed that by polishing the conductor edge the potential roughness on the selected wire can be reduced. Furthermore we give different other designs and discuss the creation of a 1D magnetic lattice on an atom chip.Comment: 6 pages, 8 figure

Analysis of Amphetamine and Congeners in Illicit Samples by Liquid Chromatography and Capillary Electrophoresis

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Century-scale paleoclimatic reconstruction from Moon Lake, a closed-basin lake in the northern Great Plains

Estimates of past lake-water salinity from fossil diatom assemblages were used to infer past climatic conditions at Moon Lake, a climatically sensitive site in the northern Great Plains. A good correspondence between diatom-inferred salinity and historical records of mean annual precipitation minus evapotranspiration (P - ET) strongly suggests that the sedimentary record from Moon Lake can be used to reconstruct past climatic conditions. Century-scale analysis of the Holocene diatom record indicates four major hydrological periods: an early Holocene transition from an open freshwater system to a closed saline system by 7300 B.P., which corresponds with a transition from spruce forest to deciduous parkland to prairie and indicates a major shift from wet to dry climate; a mid-Holocene period of high salinity from 7300 to 4700 B.P., indicating low effective moisture (P - ET); a transitional period of high salinity from 4700 to 2200 B.P., characterized by poor diatom preservation; and a late Holocene period of variable lower salinity during the past 2,200 yr, indicating fluctuations in effective moisture