4,870 research outputs found
Recommended from our members
Systemic risk determinants in the European banking industry during financial crises, 2006-2012
The recent financial turmoil has stimulated a rich debate in banking and financial literature on the identification of systemic risk determinants and devices to forecast and prevent crises. This paper explores the contribution of corporate variables to systemic risk using the CoVaR approach (Adrian and Brunnermeier, 2016). Using balanced panel data on 141 European banks from 24 countries, which were listed from 2006Q1 to 2012Q4, we investigated the impact of corporate variables during the three regimes that characterised the European banking sector-the subprime crisis (2007Q3-2008Q3), the European Great Financial Depression (2008Q4-2010Q2), and the sovereign debt crisis (2010Q3-2012Q4). Our results show that size did not play a significant role in spreading systemic risk, while maturity mismatch did. However, the nature and intensity of these two determinants varied across the three regimes
Electrostatic tailoring of magnetic interference in quantum point contact ballistic Josephson junctions
The magneto-electrostatic tailoring of the supercurrent in quantum point
contact ballistic Josephson junctions is demonstrated. An etched InAs-based
heterostructure is laterally contacted to superconducting niobium leads and the
existence of two etched side gates permits, in combination with the application
of a perpendicular magnetic field, to modify continuously the magnetic
interference pattern by depleting the weak link. For wider junctions the
supercurrent presents a Fraunhofer-like interference pattern with periodicity
h/2e whereas by shrinking electrostatically the weak link, the periodicity
evolves continuously to a monotonic decay. These devices represent novel
tunable structures that might lead to the study of the elusive Majorana
fermions.Comment: 4.5 pages, 4 color figure
Singlet-triplet transition in a few-electron lateral InGaAs-InAlAs quantum dot
The magnetic-field evolution of Coulomb blockade peaks in lateral
InGaAs/InAlAs quantum dots in the few-electron regime is reported. Quantum dots
are defined by gates evaporated onto a 60 nm-thick hydrogen silsesquioxane
insulating film. A gyromagnetic factor of 4.4 is measured via zero-bias spin
spectroscopy and a transition from singlet to triplet spin configuration is
found at an in-plane magnetic field B = 0.7 T. This observation opens the way
to the manipulation of singlet and triplet states at moderate fields and its
relevance for quantum information applications will be discussed.Comment: 4 pages, 3 figure
Diffuse Gas and LMXBs in the Chandra Observation of the S0 Galaxy NGC 1553
We have spatially and spectrally resolved the sources of X-ray emission from
the X-ray faint S0 galaxy NGC 1553 using an observation from the Chandra X-ray
Observatory. The majority (70%) of the emission in the 0.3 - 10.0 keV band is
diffuse, and the remaining 30% is resolved into 49 discrete sources. Most of
the discrete sources associated with the galaxy appear to be low mass X-ray
binaries (LMXBs). The luminosity function of the LMXB sources is well-fit by a
broken power-law with a break luminosity comparable to the Eddington luminosity
for a 1.4 solar mass neutron star. It is likely that those sources with
luminosities above the break are accreting black holes and those below are
mostly neutron stars in binary systems. Spectra were extracted for the total
emission, diffuse emission, and sum of the resolved sources; the spectral fits
for all require a model including both a soft and hard component. The diffuse
emission is predominately soft while the emission from the sources is mostly
hard. Approximately 24% of the diffuse emission arises from unresolved LMXBs,
with the remainder resulting from thermal emission from hot gas. There is a
very bright source at the projected position of the nucleus of the galaxy. The
spectrum and luminosity derived from this central source are consistent with it
being an AGN; the galaxy also is a weak radio source. Finally, the diffuse
emission exhibits significant substructure with an intriguing spiral feature
passing through the center of the galaxy. The X-ray spectrum and surface
brightness of the spiral feature are consistent with adiabatic or shock
compression of ambient gas, but not with cooling. This feature may be due to
compression of the hot interstellar gas by radio lobes or jets associated with
the AGN.Comment: 23 pages using emulateapj.sty; ApJ, in press; revised version
includes correction to error in the L_X,src/L_B ratio as well as other
revision
Acid gas removal from natural gas by water washing
Projections in the future energy scenario outline an important role played by fossil fuels to meet the increasing
global energy demand. A “golden age” has been recently outlined for natural gas, in particular, as the fastest
growing and the cleanest of all fossil fuels. Although natural gas is mostly considered to be a “clean” fuel with
respect to the emission of pollutants from its combustion, the raw natural gas found in reservoir deposits is not
free of contaminants. Among the others, hydrogen sulphide and carbon dioxide are two undesired
compounds, which are responsible for the sour or acidic nature of natural gas and must be removed for
operational and safety reasons. Acid gas treating is typically performed in facilities built at surface locations,
mainly by means of chemical absorption into aqueous amine solutions. However, subsurface technologies
may allow to possibly separate the gas undesired compounds directly downhole. The high pressure
encountered in this environment makes the use of water as liquid absorbent worth considering. This work
investigates the possibility of acid gas removal from natural gas by downhole water washing and presents a
preliminary evaluation of the performances of the process, which is assumed to be carried out in the gas
production casing that can be represented as a bubble column. A previously proposed correlation for the gas
holdup in this type of contacting device operated counter-currently has been used to determine the volumetric
mass transfer coefficient for design purposes, considering different raw gas flow rates and inlet acid gas
concentrations. By solving a simplified model of a bubble column and by using water flow rates compatible
with reinjection into the reservoir, it has been found that it is possible to reduce the H2S content from the inlet
concentration to the commonly accepted value to meet pipeline specifications and, depending on the inlet CO2
concentration, to perform a bulk removal of it
- …