Superconducting NdCeCuO Bicrystal Grain Boundary Josephson Junctions

We have studied the electric transport properties of symmetrical [001] tilt NdCeCuO bicrystal grain boundary Josephson junctions (GBJs) fabricated on SrTiO bicrystal substrates with misorientation angles of 24 and 36.8 degree. The superconducting properties of the NdCeCuO-GBJs are similar to those of GBJs fabricated from the hole doped high temperature superconductors (HTS). The critical current density Jc decreases strongly with increasing misorientation angle. The products of the critical current Ic and the normal resistance Rn (about 0.1 mV at 4.2 K) are small compared to the gap voltage and fit well to the universal scaling law (IcRn is proportional to the square root of Jc) found for GBJs fabricated from the hole doped HTS. This suggests that the symmetry of the order parameter, which most likely is different for the electron and the hole doped HTS has little influence on the characteristic properties of symmetrical [001] tilt GBJs.Comment: 3 pages, 4 figures, to be published in Applied Physics Letter

Andreev Bound States in High Temperature Superconductors

Andreev bound states (ABS) at the surface of superconductors are expected for any pair potential showing a sign change in different k-directions with their spectral weight depending on the relative orientation of the surface and the pair potential. We report on the observation of ABS in HTS employing tunneling spectroscopy on bicrystal grain boundary Josephson junctions (GBJs). The tunneling spectra were studied as a function of temperature and applied magnetic field. The tunneling spectra of GBJ formed by YBCO, BSCCO, and LSCO show a pronounced zero bias conductance peak that can be interpreted in terms of Andreev bound states at zero energy that are expected at the surface of HTS having a d-wave symmetry of the order parameter. In contrast, for the most likely s-wave HTS NCCO no zero bias conductance peak was observed. Applying a magnetic field results in a shift of spectral weight from zero to finite energy. This shift is found to depend nonlinearly on the applied magnetic field. Further consequences of the Andreev bound states are discussed and experimental evidence for anomalous Meissner currents is presented.Comment: 17 pages, 10 figures, to appear in Eur. Phys. J.

The Role of Climate Perceptions, Expectations, and Forecasts in Farmer Decision Making: The Argentine Pampas and South Florida: Final Report of an IRI Seed Grant Project

This project sought to extend previous research efforts with both a “front end” – mental models that influence climatic expectations and forecast applications – and a “back end” – the decision processes in response to climate expectations derived from farmers’ mental models and externally-provided information. Research in this report was motivated by three lines of social science inquiry: (a) the importance of subjective perception of risk, (b) differences in the impact of small-probability events when information about them is learned by personal experience over time as opposed to being provided as a statistical summary, and (c) the role of both material and nonmaterial (including cognitive and affective) goals and processes in risky decision making. This study provided multiple insights into determinants of use of climate information related to perception and communication, and some evidence that improved presentation may overcome some of the barriers and enhance utility. We see several avenues for extending results and addressing limitations of the project’s scope and study design

К вопросу о построении универсальной тепловой диаграммы идеального газа

The application of optical coherence tomography OCT in tissue engineering facilities offers great potential for the automated detection of defects or inhomogeneities in tissue products. This non-invasive and non-destructive measurement technique enables the high speed generation of two dimensional cross sections of tissue with micron resolution. The integration of an OCT device into a tissue production facility allows the monitoring and quality control of tissue engineering products. By the selective exclusion of tissue products with insufficient quality features a high degree in production standard is guaranteed. In a first study, OCT tomograms of artificial skin equivalents were acquired and compared with microscopic images of associated histologies. As a result, a well-defined analogy of the obtained images is presented. The most common defect in terms of hole structures that occurs due to a procedural steps could be detected. Further characteristics like the topogra phy, homogeneity and layer structure was analysed. Hence, OCT provides a powerful measurement technique to monitor the quality of tissue products in automated tissue engineering facilities

The Millennium Arecibo 21-CM Absorption Line Survey. II. Properties of the Warm and Cold Neutral Media

We use the Gaussian-fit results of Paper I to investigate the properties of interstellar HI in the Solar neighborhood. The Warm and Cold Neutral Media (WNM and CNM) are physically distinct components. The CNM spin temperature histogram peaks at about 40 K. About 60% of all HI is WNM. At z=0, we derive a volume filling fraction of about 0.50 for the WNM; this value is very rough. The upper-limit WNM temperatures determined from line width range upward from about 500 K; a minimum of about 48% of the WNM lies in the thermally unstable region 500 to 5000 K. The WNM is a prominent constituent of the interstellar medium and its properties depend on many factors, requiring global models that include all relevant energy sources, of which there are many. We use Principal Components Analysis, together with a form of least squares fitting that accounts for errors in both the independent and dependent parameters, to discuss the relationships among the four CNM Gaussian parameters. The spin temperature T_s and column density N(HI) are, approximately, the two most important eigenvectors; as such, they are sufficient, convenient, and physically meaningful primary parameters for describing CNM clouds. The Mach number of internal macroscopic motions for CNM clouds is typically 2.5, but there are wide variations. We discuss the historical tau-T_s relationship in some detail and show that it has little physical meaning. We discuss CNM morphology using the CNM pressure known from UV stellar absorption lines. Knowing the pressure allows us to show that CNM structures cannot be isotropic but instead are sheetlike, with length-to-thickness aspect ratios ranging up to about 280. We present large-scale maps of two regions where CNM lies in very large ``blobby sheets''.Comment: Revised submission to Ap.J. Changes include: (1) correction of turbulent Mach number in equation 16 and figure 12; the new typical value is 1.3 versus the old, incorrect value 2.5. (2) smaller typeface for the astro-ph version to conserve paper. 60 pages, 16 figure

Greening Capitalism? A Marxist Critique of Carbon Markets

Climate change is increasingly being recognized as a serious threat to dominant modes of social organization, inspiring suggestions that capitalism itself needs to be transformed if we are to ‘decarbonize’ the global economy. Since the Kyoto Protocol in 1997, carbon markets have emerged as the main politico-economic tools in global efforts to address climate change. Newell and Paterson (2010) have recently claimed that the embrace of carbon markets by financial and political elites constitutes a possible first step towards the transformation of current modes of capitalist organization into a new form of greener, more sustainable ‘climate capitalism.’ In this paper, we argue that the institutionalization of carbon markets does not, in fact, represent a move towards the radical transformation of capitalism, but is better understood as the most recent expression of ongoing trends of ecological commodification and expropriation, driving familiar processes of uneven and crisis-prone development. In this paper, we review four critical Marxist concepts: metabolic rift (Foster, 1999), capitalism as world ecology (Moore, 2011a), uneven development and accumulation through dispossession (Harvey, 2003, 2006), and sub-imperialism (Marini, 1972, 1977), developing a framework for a Marxist analysis of carbon markets. Our analysis shows that carbon markets form part of a longer historical development of global capitalism and its relation to nature. Carbon markets, we argue, serve as creative new modes of accumulation, but are unlikely to transform capitalist dynamics in ways that might foster a more sustainable global economy. Our analysis also elucidates, in particular, the role that carbon markets play in exacerbating uneven development within the Global South, as elites in emerging economies leverage carbon market financing to pursue new strategies of sub-imperial expansion. </jats:p

A 4.8- and 8.6-GHz Survey of the Large Magellanic Cloud: I The Images

Detailed 4.8- and 8.6-GHz radio images of the entire Large Magellanic Cloud with half-power beamwidths of 33" at 4.8 GHz and 20" at 8.6 GHz have been obtained using the Australia Telescope Compact Array. A total of 7085 mosaic positions were used to cover an area of 6 degrees on a side. Full polarimetric observations were made. These images have sufficient spatial resolution (~8 and 5 pc, respectively) and sensitivity (3-sigma of 1 mJy/beam) to identify most of the individual SNRs and H II regions and also, in combination with available data from the Parkes 64-m telescope, the structure of the smooth emission in that galaxy. In addition, limited data using the sixth antenna at 4.5 to 6-km baselines are available to distinguish bright point sources (<3 and 2 arcsec, respectively) and to help estimate sizes of individual sources smaller than the resolution of the full survey. The resultant database will be valuable for statistical studies and comparisons with x-ray, optical and infrared surveys of the LMC with similar resolution.Comment: 28 pages, 10 figures, 2 tables, accepted for publication in the Feb 2005 A

Efficiency in Multi-objective Games

In a multi-objective game, each agent individually evaluates each overall action-profile on multiple objectives. I generalize the price of anarchy to multi-objective games and provide a polynomial-time algorithm to assess it. This work asserts that policies on tobacco promote a higher economic efficiency

Displacement of propagating squeezed microwave states

Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments we have successfully implemented this operation for propagating squeezed microwave states. We demonstrate that, even for strong displacement amplitudes, there is no degradation of the squeezing level in the reconstructed quantum states. Furthermore, we confirm that path entanglement generated by using displaced squeezed states stays constant over a wide range of the displacement power