Internationalizing the political economy of hydroelectricity: security, development, and sustainability in hydropower states

Our study offers a comparative assessment of the economic, sociopolitical, and environmental implications of the world’s largest source of renewable electricity, hydropower. Theorists from many disciplines have questioned both the proper role and ostensible benefits from the generation of electricity from large-scale hydroelectric dams. In this study, we use 30 years of World Bank data from 1985 to 2014 and a research design with three mutually exclusive reference classes of countries: major hydropower producers, members of OPEC, and all other countries. This is precisely so our analysis moves away from “dam-centric” or single case study approaches to comparative analysis at the international scale. We examine and test six separate hypotheses related to (a) military conflict, (2) poverty, (3) economic growth, (4) public debt, (5) corruption, and (6) greenhouse gas emissions. Our analysis lends statistical support to the idea that there is such a thing as a “hydroelectric resource curse,” although effects were not always significant and varied from small, medium to large. The possible benefits of hydroelectricity—improved energy access, economic development, positive spillover effects—are real, but they are all too frequently constrained. Planners, investors, and researchers may therefore need to rethink their underlying assumptions about how they evaluate hydropower’s risk

INTEGRAL discovery of persistent hard X-ray emission from the Soft Gamma Ray Repeater SGR 1806-20

We report the discovery of persistent hard X-ray emission extending up to 150 keV from the soft gamma-ray repeater SGR 1806-20 using data obtained with the INTEGRAL satellite in 2003-2004. Previous observations of hard X-rays from objects of this class were limited to short duration bursts and rare transient episodes of strongly enhanced luminosity (``flares''). The emission observed with the IBIS instrument above 20 keV has a power law spectrum with photon index in the range 1.5-1.9 and a flux of 3 milliCrabs, corresponding to a 20-100 keV luminosity of ~10^36 erg s^-1 (for a distance of 15 kpc). The spectral hardness and the luminosity correlate with the level of source activity as measured from the number of emitted bursts.Comment: 5 pages, 3 figures, Revised version accepted for publication in Astronomy and Astrophysics Letter

Effect of sulphur and nitrogen fertilization on bread-making quality of wheat (Triticum aestivum L.) varieties under Mediterranean climate conditions

Turkey has applied for EU-membership, but still faces problems of lacking quality standards for bread wheat. Studies on the influence of S-fertilization on grain yield and bread-making quality of wheat (Triticum aestivum L.) in the region haven’t been carried out until today. This research was conducted for two growing seasons (2008-2009 and 2009-2010) at Adnan Menderes University Research and Experimental Farm located in the Western Turkey (Aegean region) at 37º 44’ N 27º 44’ E in order to determine the effects of nitrogen (0, 70, 140, 210 kg ha-1) supplemented with sulphur (0 or 40 kg ha-1) with respect to yield and bread-making quality of the varieties Golia and Sagittario, grown primarily in Western Turkey. S-fertilization had positive effects on grain yield and some quality parameters under Mediterranean conditions; however, signifi cant differencess were rather rare. Particularly the gluten-index and the sedimentation value promoted by S fertilization were among the tested parameters. Therefore, S-fertilization in improving bread-making quality of wheat in the region should not be disregarded. Grain yield and quality could be promoted simultaneously with increasing N-doses

Co-sputtered MoRe thin films for carbon nanotube growth-compatible superconducting coplanar resonators

Molybdenum rhenium alloy thin films can exhibit superconductivity up to critical temperatures of $T_c=15\mathrm{K}$. At the same time, the films are highly stable in the high-temperature methane / hydrogen atmosphere typically required to grow single wall carbon nanotubes. We characterize molybdenum rhenium alloy films deposited via simultaneous sputtering from two sources, with respect to their composition as function of sputter parameters and their electronic dc as well as GHz properties at low temperature. Specific emphasis is placed on the effect of the carbon nanotube growth conditions on the film. Superconducting coplanar waveguide resonators are defined lithographically; we demonstrate that the resonators remain functional when undergoing nanotube growth conditions, and characterize their properties as function of temperature. This paves the way for ultra-clean nanotube devices grown in situ onto superconducting coplanar waveguide circuit elements.Comment: 8 pages, 6 figure

Ground-state characterization of Nb charge-phase Josephson qubits

We present investigations of Josephson charge-phase qubits inductively coupled to a radio-frequency driven tank-circuit enabling the readout of the states by measuring the Josephson inductance of the qubit. The circuits including junctions with linear dimensions of 60 nm and 80 nm are fabricated from Nb trilayer and allowing the determination of relevant sample parameters at liquid helium temperature. The observed partial suppression of the circulating supercurrent at 4.2 K is explained in the framework of a quantum statistical model. We have probed the ground-state properties of qubit structures with different ratios of the Josephson coupling to Coulomb charging energy at 20 mK, demonstrating both the magnetic control of phase and the electrostatic control of charge on the qubit island.Comment: 8 pages, 8 figure

Spectral Properties of Magnetic Excitations in Cuprate Two-Leg Ladder Systems

This article summarizes and extends the recent developments in the microscopic modeling of the magnetic excitations in cuprate two-leg ladder systems. The microscopic Hamiltonian comprises dominant Heisenberg exchange terms plus an additional four-spin interaction which is about five times smaller. We give an overview over the relevant energies like the one-triplon dispersion, the energies of two-triplon bound states and the positions of multi-triplon continua and over relevant spectral properties like spectral weights and spectral densities in the parameter regime appropriate for cuprate systems. It is concluded that an almost complete understanding of the magnetic excitations in undoped cuprate ladders has been obtained as measured by inelastic neutron scattering, inelastic light (Raman) scattering and infrared absorption.Comment: 26 pages, 10 figures, review for Mod. Phys. Lett.