Global Aspects of Abelian Duality in Dimension Three

In three dimensions, an abelian gauge field is related by duality to a free, periodic scalar field. Though usually considered on Euclidean space, this duality can be extended to a general three-manifold M, in which case topological features of M become important. Here I comment upon several of these features as related to the partition function on M. In a companion article, arXiv:1405.2483, I discuss similarly the algebra of operators on a surface of genus g.Comment: 62 pages, 1 figure, v2: references adde

German-language culture and the Slav stranger within

The aim of this article is to delineate the symbolic position of the Slavonic, and in particular the Czech, in German-language Austrian culture of the period 1890–1940. My approach will be informed by psychoanalysis. A subsidiary aim is to try to demonstrate uses of psychoanalysis in the study of central European culture. What is at issue here is an historical set of social power relations that find their expression in culture, that is to say, in art and literature, and that can be interpreted by psychoanalysis. All too often psychoanalysis avoids the social and the political outside the framework of the individual and her or his predictable traumas emanating from domestic life.1 This article, however, constitutes an exercise in inter- and intra-cultural psychoanalysis: intra-cultural as an investigation of psychoanalytic dynamics within German-language culture; inter-cultural as an examination of the relationship between German-language and Slav cultures in psychoanalytic terms

Comparing Three Water Quality Sampling Techniques for Measuring Non-Point Source Pollution in Forest Streams

Coshocton wheel samplers, ISCO pumping samplers, and single stage samplers were compared on each of three small (5-6 ha), forested watersheds in the Ouachita Mountains of central Arkansas. The objective of the comparisons was to evaluate the performance of each sampling method in providing reliable samples for measuring concentrations of total suspended solids (TSS). H-flumes and water level recorders provided stream discharge data; a network of recording and non-recording raingages provided preciptation measurements. Rainfall and storm discharges during the study period were unusually low. No samples were collected by the single stage samplers. They appear unsuited for use on small ephemeral headwater streams in the ~achita Mountains because only unusually large storms will provide the depth of flow required to fill the sample bottles. A few of the Coshocton Wheel samples provided eradic and unpredictable measurements of TSS; however, there was generally good agreement between the Coshoston and pumped samples. The ISCO pumping samplers provided data that were more consistent and predictable than that of the Coshocton wheel. The small number of storm events during the study precludes a definite conclusion as to which sampling method is best . Measurements are continuing

Macroinvertebrates, Heavy Metals and PAHs in Urban Watercourses

Good quality stream water and sediments are crucial for the support of healthy stream flora and fauna but urban runoff degrades watercourses leaving a legacy of pollution in the stream sediments. The sediment pollution load influences the development of macroinvertebrates which, as the lowest member of the food chain, influences the whole ecological structure. This review focuses on defining the sources and impacts of zinc, nickel, copper and oil derivative polycyclic aromatic hydrocarbon (PAH) contaminants in urban runoff. The impact of pollutants as measured by laboratory, field and modelling procedures are considered. Land use, position and connectivity of the runoff and sediment are seen to have an effect on the ecological integrity of the watercourse but case examples are sparse. The literature indicates that while reduced species diversity has been identified at a number of sites the dynamics are not well understood nor well modelled. These results are compared with field evidence from a study of 62 headwater streams with urban industrial and motorway land uses. From the review and field results it is evident that there is still an important need for process-based field measurements of urban water quality parameters. Forecasting the ecological status of watercourses would seem to benefit from data on sediment chemistry that considers the interaction effects of metals and PAHs

Design and Performance of a Practical Variable-Temperature Scanning Tunneling Potentiometry System

We have constructed a scanning tunneling potentiometry system capable of simultaneously mapping the transport-related electrochemical potential of a biased sample along with its surface topography. Combining a novel sample biasing technique with a continuous current-nulling feedback scheme pushes the noise performance of the measurement to its fundamental limit - the Johnson noise of the STM tunnel junction. The resulting 130 nV voltage sensitivity allows us to spatially resolve local potentials at scales down to 2 nm, while maintaining angstrom scale STM imaging, all at scan sizes of up to 15 um. A mm-range two-dimensional coarse positioning stage and the ability to operate from liquid helium to room temperature with a fast turn-around time greatly expand the versatility of the instrument. By performing studies of several model systems, we discuss the implications of various types of surface morphology for potentiometric measurements.Comment: 16 pages, 17 figures, accepted to Review of Scientific Instruments v2 - minor changes: cleaned up figures/figure caption