Capital requirements and business cycles with credit market imperfections

The business cycle effects of bank capital regulatory regimes are examined in a New Keynesian model with credit market imperfections and a cost channel of monetary policy. Key features of the model are that bank capital increases incentives for banks to monitor borrowers, thereby reducing the probability of default, and excess capital generates benefits in terms of reduced regulatory scrutiny. Basel I and Basel II-type regulatory regimes are defined, and the model is calibrated for a middle-income country. Simulations of supply and demand shocks show that, depending on the elasticity that relates the repayment probability to the capital-loan ratio, a Basel II-type regime may be less procyclical than a Basel I-type regime.Banks&Banking Reform,Debt Markets,Access to Finance,Economic Theory&Research,Emerging Markets

Characterization of InGaN and InAlN epilayers by microdiffraction X-Ray reciprocal space mapping

We report a study of InGaN and InAlN epilayers grown on GaN/Sapphire substrates by microfocused three-dimensional X-ray Reciprocal Space Mapping (RSM). The analysis of the full volume of reciprocal space, while probing samples on the microscale with a focused X-ray beam, allows us to gain uniquely valuable information about the microstructure of III-N alloy epilayers. It is found that “seed” InGaN mosaic nanocrystallites are twisted with respect to the ensemble average and strain free. This indicates that the growth of InGaN epilayers follows the Volmer-Weber mechanism with nucleation of “seeds” on strain fields generated by the a-type dislocations which are responsible for the twist of underlying GaN mosaic blocks. In the case of InAlN epilayer formation of composition gradient was observed at the beginning of the epitaxial growth

Food System Transformation: Integrating a Political-Economy and Social-Ecological Approach to Regime Shifts.

Sustainably achieving the goal of global food security is one of the greatest challenges of the 21st century. The current food system is failing to meet the needs of people, and at the same time, is having far-reaching impacts on the environment and undermining human well-being in other important ways. It is increasingly apparent that a deep transformation in the way we produce and consume food is needed in order to ensure a more just and sustainable future. This paper uses the concept of regime shifts to understand key drivers and innovations underlying past disruptions in the food system and to explore how they may help us think about desirable future changes and how we might leverage them. We combine two perspectives on regime shifts-one derived from natural sciences and the other from social sciences-to propose an interpretation of food regimes that draws on innovation theory. We use this conceptualization to discuss three examples of innovations that we argue helped enable critical regime shifts in the global food system in the past: the Haber-Bosch process of nitrogen fixation, the rise of the supermarket, and the call for more transparency in the food system to reconnect consumers with their food. This paper concludes with an exploration of why this combination of conceptual understandings is important across the Global North/ Global South divide, and proposes a new sustainability regime where transformative change is spearheaded by a variety of social-ecological innovations

Third edge for a graphene nanoribbon: A tight-binding model calculation

The electronic and transport properties of an extended linear defect embedded in a zigzag nanoribbon of realistic width are studied, within a tight binding model approach. Our results suggest that such defect profoundly modify the properties of the nanoribbon, introducing new conductance quantization values and modifying the conductance quantization thresholds. The linear defect along the nanoribbon behaves as an effective third edge of the system, which shows a metallic behavior, giving rise to new conduction pathways that could be used in nanoscale circuitry as a quantum wire.Comment: 6 pages, 6 figures. Two new figures and a few references adde

Dynamical Evolution of a Cylindrical Shell with Rotational Pressure

We prepare a general framework for analyzing the dynamics of a cylindrical shell in the spacetime with cylindrical symmetry. Based on the framework, we investigate a particular model of a cylindrical shell-collapse with rotational pressure, accompanying the radiation of gravitational waves and massless particles. The model has been introduced previously but has been awaiting for proper analysis. Here the analysis is put forward: It is proved that, as far as the weak energy condition is satisfied outside the shell, the collapsing shell bounces back at some point irrespective of the initial conditions, and escapes from the singularity formation. The behavior after the bounce depends on the sign of the shell pressure in the z-direction. When the pressure is non-negative, the shell continues to expand without re-contraction. On the other hand, when the pressure is negative (i.e. it has a tension), the behavior after the bounce can be more complicated depending on the details of the model. However, even in this case, the shell never reaches the zero-radius configuration.Comment: To appear in Phys. Rev.

Reducing Shower Duration in Tourist Accommodations: A Covert True Experiment of Continuous Real-Time Eco-Feedback and Persuasive Messaging

This study inductively applies the Feedback Intervention Theory by empirically demonstrating the effectiveness of continuous, real-time eco-feedback and its interaction with motivational factors in modifying showering behavior. We conducted a covert true experiment across six tourist accommodations in Denmark, Spain, and the UK, where we deployed smart technology, in the form of a timer to provide the eco-feedback, coupled with persuasive messages. Data from over 17,500 showers showed that continuous, real-time eco-feedback reduced water runtime by 25.79% (CI = 8.24%; 39.98%). When the eco-feedback was paired with the most effective message—priming pro-environmental values and requiring a high effort to comply—water runtime was reduced by 23.55% (CI = 17.53%; 29.13%). The study’s robust experimental design, and its emphasis on actual behavior measurement, highlight the potential of smart technology to facilitate resource conservation

Far-infrared line spectra of active galaxies from the Herschel/PACS Spectrometer: the complete database

We present a coherent database of spectroscopic observations of far-IR fine-structure lines from the Herschel/PACS archive for a sample of 170 local AGN, plus a comparison sample of 20 starburst galaxies and 43 dwarf galaxies. Published Spitzer/IRS and Herschel/SPIRE line fluxes are included to extend our database to the full 10-600 $\mu m$ spectral range. The observations are compared to a set of CLOUDY photoionisation models to estimate the above physical quantities through different diagnostic diagrams. We confirm the presence of a stratification of gas density in the emission regions of the galaxies, which increases with the ionisation potential of the emission lines. The new [OIV]25.9$\mu m$/[OIII]88$\mu m$ vs [NeIII]15.6$\mu m$/[NeII]12.8$\mu m$ diagram is proposed as the best diagnostic to separate: $i)$ AGN activity from any kind of star formation; and $ii)$ low-metallicity dwarf galaxies from starburst galaxies. Current stellar atmosphere models fail to reproduce the observed [OIV]25.9$\mu m$/[OIII]88$\mu m$ ratios, which are much higher when compared to the predicted values. Finally, the ([NeIII]15.6$\mu m$ + [NeII]12.8$\mu m$)/([SIV]10.5$\mu m$ + [SIII]18.7$\mu m$) ratio is proposed as a promising metallicity tracer to be used in obscured objects, where optical lines fail to accurately measure the metallicity. The diagnostic power of mid- to far-infrared spectroscopy shown here for local galaxies will be of crucial importance to study galaxy evolution during the dust-obscured phase at the peak of the star formation and black-hole accretion activity ($1 < z < 4$). This study will be addressed by future deep spectroscopic surveys with present and forthcoming facilities such as JWST, ALMA, and SPICA.Comment: Accepted for publication in the ApJ

Heating of the molecular gas in the massive outflow of the local ultraluminous-infrared and radio-loud galaxy 4C12.50

We present a comparison of the molecular gas properties in the outflow vs. in the ambient medium of the local prototype radio-loud and ultraluminous-infrared galaxy 4C12.50 (IRAS13451+1232), using new data from the IRAM Plateau de Bure interferometer and 30m telescope, and the Herschel space telescope. Previous H_2 (0-0) S(1) and S(2) observations with the Spitzer space telescope had indicated that the warm (~400K) molecular gas in 4C12.50 is made up of a 1.4(+-0.2)x10^8 M_sun ambient reservoir and a 5.2(+-1.7)x10^7 M_sun outflow. The new CO(1-0) data cube indicates that the corresponding cold (25K) H_2 gas mass is 1.0(+-0.1)x10^10 M_sun for the ambient medium and <1.3x10^8 M_sun for the outflow, when using a CO-intensity-to-H_2-mass conversion factor alpha of 0.8 M_sun /(K km/s pc^2). The combined mass outflow rate is high, 230-800 M_sun/yr, but the amount of gas that could escape the galaxy is low. A potential inflow of gas from a 3.3(+-0.3)x10^8 M_sun tidal tail could moderate any mass loss. The mass ratio of warm-to-cold molecular gas is >= 30 times higher in the outflow than in the ambient medium, indicating that a non-negligible fraction of the accelerated gas is heated to temperatures at which star formation is inefficient. This conclusion is robust against the use of different alpha factor values, and/or different warm gas tracers (H_2 vs. H_2 plus CO): with the CO-probed gas mass being at least 40 times lower at 400K than at 25K, the total warm-to-cold mass ratio is always lower in the ambient gas than in the entrained gas. Heating of the molecular gas could facilitate the detection of new outflows in distant galaxies by enhancing their emission in intermediate rotational number CO lines.Comment: A&A, in pres

Anaerobic biodegradation of aniline under different electron accepting conditions

Aromatic amines are important industrial chemicals. Due to their high toxicity and persistency in both water and soils, they are of environmental concern. Aniline is not biodegradable in normal anaerobic condition. A novel approach of anaerobic biodegradation coupled with selective redox mediators, is proposed. Different redox mediators, namely manganese dioxide, Ferric citrate, ferrous chloride and magnetic iron oxide nanoparticle were tested. Fe3O4 nanoparticles, with size of 10 nm, were shown as the best, leading to 98 % of aniline removal efficiency within 24 h of operation at 37 °C. Biodegradation of aniline followed a pseudo first order kinetic model. Products of reaction were identified by GC/MS, revealing that the biodegradation occurred via catechol pathway. Methanogenic activity tests suggest that an IC50 of aniline is ~10 mM and that Fe3O4 nanoparticles are not toxic on un-adapted biomass

Electrostatically confined Quantum Rings in bilayer Graphene

We propose a new system where electron and hole states are electrostatically confined into a quantum ring in bilayer graphene. These structures can be created by tuning the gap of the graphene bilayer using nanostructured gates or by position-dependent doping. The energy levels have a magnetic field ($B_{0}$) dependence that is strikingly distinct from that of usual semiconductor quantum rings. In particular, the eigenvalues are not invariant under a $B_0 \to -B_0$ transformation and, for a fixed total angular momentum index $m$, their field dependence is not parabolic, but displays two minima separated by a saddle point. The spectra also display several anti-crossings, which arise due to the overlap of gate-confined and magnetically-confined states.Comment: 5 pages, 6 figures, to appear in Nano Letter