Determinants of residential water demand in Germany

In this paper we econometrically analyze the impact of several economic, environmental and social determinants for the average per capita demand for water and sewage in about 600 water supply areas in Germany. Besides prices, income and household size, we also consider the effects of population age, the share of wells, and rainfall and temperature during the summer months on water demand. We also attempt to explain regional differences in per capita residential water consumption, which is currently about 30 % lower in the new federal states than in the old states. Our estimate for the price elasticity of -0.229 suggests that the response of residential water demand in Germany is rather inelastic, but no significant difference could be found between both regions. In contrast, the income elasticity in the new states is found to be 0.685 which is more than double that of the old states. Differences in prices and income alone explain the largest part of the current gap in residential water use between the two regions. Our results further suggest that household size, the share of wells and summer rainfall have a negative impact on water demand. In contrast, higher age appears to be associated with higher water use. We also find (weak) evidence for an impact of rainfall but not of temperature on residential water use. Our findings imply that future research should include analyses of household- level data to further explore the effects of socio-economic determinants, and analyses of panel data to adequately study the effects of climate change on residential water use. --

Substrate-enhanced infrared near-field spectroscopy

17 pages, 8 figures.-- OCIS codes: 240.6490, 300.6340, 180.4243, 290.5825.-- © 2008 Optical Society of America.We study the amplitude and phase signals detected in infrared scattering-type near field optical microscopy (s-SNOM) when probing a thin sample layer on a substrate. We theoretically describe this situation by solving the electromagnetic scattering of a dipole near a planar sample consisting of a substrate covered by thin layers. We perform calculations to describe the effect of both weakly (Si and SiO2) and strongly (Au) reflecting substrates on the spectral s-SNOM signal of a thin PMMA layer. We theoretically predict, and experimentally confirm an enhancement effect in the polymer vibrational spectrum when placed on strongly reflecting substrates. We also calculate the scattered fields for a resonant tip-substrate interaction, obtaining a dramatic enhancement of the signal amplitude and spectroscopic contrast of the sample layer, together with a change of the spectral line shape. The enhanced contrast opens the possibility to perform ultra-sensitive near field infrared spectroscopy of monolayers and biomolecules.We wish to acknowledge financial support from the Department of Industry of the Basque Country (ETORTEK project NANOTRON), from Gipuzkoa Foru Aldundia (nanoGUNE), from the Spanish MEC (NAN2004-08843-C05- 05 and MAT2007-66050), from BMBF grant no. 03N8705, and from the Bavarian California Technology Center (BaCaTec). T.T. was supported by a fellowship within the Postdoc-Programme of the German Academic Exchange Service (DAAD).Peer reviewe

The dust, planetesimals and planets of HD 38529

HD 38529 is a post-main sequence G8III/IV star (3.5 Gyr old) with a planetary system consisting of at least two planets having Msin(i) of 0.8 MJup and 12.2 MJup, semimajor axes of 0.13 AU and 3.74 AU, and eccentricities of 0.25 and 0.35, respectively. Spitzer observations show that HD 38529 has an excess emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at 70 micron of 4.7, a small excess at 33 micron (S/N=2.6) and no excess <30 micron. We discuss the distribution of the potential dust-producing planetesimals from the study of the dynamical perturbations of the two known planets, considering in particular the effect of secular resonances. We identify three dynamically stable niches at 0.4-0.8 AU, 20-50 AU and beyond 60 AU. We model the spectral energy distribution of HD 38529 to find out which of these niches show signs of harboring dust-producing plantesimals. The secular analysis, together with the SED modeling resuls, suggest that the planetesimals responsible for most of the dust emission are likely located within 20-50 AU, a configuration that resembles that of the Jovian planets + Kuiper Belt in our Solar System. Finally, we place upper limits (8E-6 lunar masses of 10 micron particles) to the amount of dust that could be located in the dynamically stable region that exists between the two planets (0.25--0.75 AU).Comment: 23 pages, including 1 table and 5 figures. Accepted for publication in Ap

A New Grounding-line Proximal Sedimentary Record from Inner Pine Island Bay

Pine Island Glacier (PIG) is one of the fastest changing ice streams of the West Antarctic Ice Sheet. Its ice shelf underwent major calving events throughout recent years. The main factor for the considerable mass loss of PIG is sub-ice shelf melting caused by the advection of warm deep water into Pine Island Bay on the shelf of the southeastern Amundsen Sea Embayment (ASE). Unique ice conditions during expedition PS104 with RV “Polarstern” to the ASE in February-March 2017 allowed to recover a 7.59 m-gravity core in an area that had been covered by the PIG ice shelf until 2015. The sediment core PS104_008-2 was taken at a water depth of 698 m near the eastern margin of the ice shelf. The new sedimentological data from the core will provide insights into sub-ice shelf environmental conditions and the Holocene history of meltwater plume deposition and oceanic ice-shelf melting. We will present results of our new multi-proxy study, including down-core lithological changes, grain size distribution and excess 210Pb data. Occasional occurrence of calcareous benthic foraminifera shells in the lower part of the core will allow the application of radiocarbon dating. Coupled with the excess 210Pb data, the AMS 14C ages will provide constraints on sub-ice shelf sediment accumulation rates and the discharge rates of subglacial meltwater plumes

Worlds Beyond: A Strategy for the Detection and Characterization of Exoplanets Executive Summary of a Report of the ExoPlanet Task Force Astronomy and Astrophysics Advisory Committee Washington, DC June 23, 2008

[No abstract

X-ray emission from young brown dwarfs in the Orion Nebula Cluster

We use the sensitive X-ray data from the Chandra Orion Ultradeep Project (COUP) to study the X-ray properties of 34 spectroscopically-identified brown dwarfs with near-infrared spectral types between M6 and M9 in the core of the Orion Nebula Cluster. Nine of the 34 objects are clearly detected as X-ray sources. The apparently low detection rate is in many cases related to the substantial extinction of these brown dwarfs; considering only the BDs with $A_V \leq 5$ mag, nearly half of the objects (7 out of 16) are detected in X-rays. Our 10-day long X-ray lightcurves of these objects exhibit strong variability, including numerous flares. While one of the objects was only detected during a short flare, a statistical analysis of the lightcurves provides evidence for continuous (`quiescent') emission in addition to flares for all other objects. Of these, the $\sim$ M9 brown dwarf COUP 1255 = HC 212 is one of the coolest known objects with a clear detection of quiescent X-ray emission. The X-ray properties (spectra, fractional X-ray luminosities, flare rates) of these young brown dwarfs are similar to those of the low-mass stars in the ONC, and thus there is no evidence for changes in the magnetic activity around the stellar/substellar boundary, which lies at $\sim$ M6 for ONC sources. Since the X-ray properties of the young brown dwarfs are also similar to those of M6--M9 field stars, the key to the magnetic activity in very cool objects seems to be the effective temperature, which determines the degree of ionization in the atmosphere.Comment: accepted for ApJS, COUP special issu

Comparison of EFTEM and STEM EELS plasmon imaging of gold nanoparticles in a monochromated TEM

We present and compare two different imaging techniques for plasmonic excitations in metallic nanoparticles based on high energy-resolution electron energy-loss spectroscopy in a monochromated transmission electron microscope. We demonstrate that a recently developed monochromated energy-filtering (EFTEM) approach can be used in addition to the well established scanning technique to directly obtain plasmon images in the energy range below 1 eV. The EFTEM technique is described in detail, and a double experiment performed on the same, triangular gold nanoparticle compares equivalent data acquired by both techniques, respectively