452 research outputs found
Highlighting the Major Trade-Offs Concerning Anti-Terrorism Policies
Human-induced security, or terrorism, is a threat to wellbeing in Europe and beyond. In this Policy Briefing, we investigate the risks involved in terrorism, both with respect to the likelihood and with respect to the consequences of acts of terrorism. Furthermore, we provide a basic analysis of existing anti-terrorism policies, the costs involved in them and their effectiveness. We show that terrorism is a very broad term, but that one can make a number of broad policy recommendations, including the fact that the rational economic approach to terrorism recognizes that terrorists respond to the incentives they are provided with
How Rational Is the Response of Individuals to the Threat of Terrorism in Europe?
In this Policy Briefing, we address two important questions. We look at the drivers of concern about terrorism and find that beyond individual characteristics, it is also affected by the occurrence of terrorism. When distinguishing between permanent and transitory terrorism, the first has a much stronger impact than the first. The second question concerns how terrorism affects the policy preferences of voters. We find that while a higher level of terrorist concern does increase people's willingness to trade off civil liberties for more security, a singular attack has only a temporary effect. After only a few months, people's preferences return towards their pre-attack levels
Synthesis of diarylamines in the benzo[b]thiophene series bearing electron donating or withdrawing groups by Buchwald–Hartwig C–N coupling
Diarylamines in the benzo[b]thiophene series bearing electron donating or withdrawing groups, were prepared by Buchwald–
Hartwig C–N coupling in moderate to high yields. The conditions used were Pd(OAc)2 (3 mol%), BINAP as ligand (4 mol%) and Cs2CO3 as
base (1.4 equiv.), in toluene at 1008C, being 6-bromo or amino benzo[b]thiophenes coupled, respectively, with substituted anilines or
phenylbromides. The 6-aminobenzo[b]thiophene derivatives were also prepared by palladium catalyzed C–N coupling of the corresponding
6-bromo compounds with benzophenone imine, followed by acidic hydrolysis of the imino derivatives. When 4-nitrobromobenzene and
4-bromobenzonitrile were used as coupling components, triarylamines were also isolated in small amounts. The presence of a fluorine atom
on the phenylbromide highly increases the diarylamine yield
Shape modeling technique KOALA validated by ESA Rosetta at (21) Lutetia
We present a comparison of our results from ground-based observations of
asteroid (21) Lutetia with imaging data acquired during the flyby of the
asteroid by the ESA Rosetta mission. This flyby provided a unique opportunity
to evaluate and calibrate our method of determination of size, 3-D shape, and
spin of an asteroid from ground-based observations. We present our 3-D
shape-modeling technique KOALA which is based on multi-dataset inversion. We
compare the results we obtained with KOALA, prior to the flyby, on asteroid
(21) Lutetia with the high-spatial resolution images of the asteroid taken with
the OSIRIS camera on-board the ESA Rosetta spacecraft, during its encounter
with Lutetia. The spin axis determined with KOALA was found to be accurate to
within two degrees, while the KOALA diameter determinations were within 2% of
the Rosetta-derived values. The 3-D shape of the KOALA model is also confirmed
by the spectacular visual agreement between both 3-D shape models (KOALA pre-
and OSIRIS post-flyby). We found a typical deviation of only 2 km at local
scales between the profiles from KOALA predictions and OSIRIS images, resulting
in a volume uncertainty provided by KOALA better than 10%. Radiometric
techniques for the interpretation of thermal infrared data also benefit greatly
from the KOALA shape model: the absolute size and geometric albedo can be
derived with high accuracy, and thermal properties, for example the thermal
inertia, can be determined unambiguously. We consider this to be a validation
of the KOALA method. Because space exploration will remain limited to only a
few objects, KOALA stands as a powerful technique to study a much larger set of
small bodies using Earth-based observations.Comment: 15 pages, 8 figures, 2 tables, accepted for publication in P&S
Model-independent evidence for contributions to decays
The data sample of decays acquired with the
LHCb detector from 7 and 8~TeV collisions, corresponding to an integrated
luminosity of 3 fb, is inspected for the presence of or
contributions with minimal assumptions about
contributions. It is demonstrated at more than 9 standard deviations that
decays cannot be described with
contributions alone, and that contributions play a dominant role in
this incompatibility. These model-independent results support the previously
obtained model-dependent evidence for charmonium-pentaquark
states in the same data sample.Comment: 21 pages, 12 figures (including the supplemental section added at the
end
Quantum numbers of the state and orbital angular momentum in its decay
Angular correlations in decays, with , and , are used to measure
orbital angular momentum contributions and to determine the value of
the meson. The data correspond to an integrated luminosity of 3.0
fb of proton-proton collisions collected with the LHCb detector. This
determination, for the first time performed without assuming a value for the
orbital angular momentum, confirms the quantum numbers to be .
The is found to decay predominantly through S wave and an upper limit
of at C.L. is set on the fraction of D wave.Comment: 16 pages, 4 figure
Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics
A detailed study is presented of the expected performance of the ATLAS
detector. The reconstruction of tracks, leptons, photons, missing energy and
jets is investigated, together with the performance of b-tagging and the
trigger. The physics potential for a variety of interesting physics processes,
within the Standard Model and beyond, is examined. The study comprises a series
of notes based on simulations of the detector and physics processes, with
particular emphasis given to the data expected from the first years of
operation of the LHC at CERN
Limit on the Radiative Neutrinoless Double Electron Capture of Ar from GERDA Phase I
Neutrinoless double electron capture is a process that, if detected, would
give evidence of lepton number violation and the Majorana nature of neutrinos.
A search for neutrinoless double electron capture of Ar has been
performed with germanium detectors installed in liquid argon using data from
Phase I of the GERmanium Detector Array (GERDA) experiment at the Gran Sasso
Laboratory of INFN, Italy. No signal was observed and an experimental lower
limit on the half-life of the radiative neutrinoless double electron capture of
Ar was established: 3.6 10 yr at 90 % C.I.Comment: 7 pages, 3 figure
Promotion of Self-Nucleation with Latent Form i Nuclei in Polybutene-1 and Its Copolymer
The formation of form I nuclei of polybutene-1 (PB-1) and its copolymer with polyethylene (PB1-ran-PE) has been studied by means of modified self-nucleation protocols. Even when the self-nucleation temperature was high enough and all form II crystals melt, recrystallization can be accelerated if the melt-crystallized sample was annealed at low temperatures (below 60 \ub0C for PB-1 and 75 \ub0C for PB1-ran-PE) for just 3 min. These results suggest the formation of latent form I nuclei within form II crystals. This hypothesis is consistent with the observed growth of a small amount of form I crystals during heating, after previous annealing at temperature lower than 20 \ub0C. In addition, a peculiar phenomenon was found in PB1-ran-PE, as both form II and form I\u2032 can be induced by the presence of latent form I nuclei, due to cross-nucleation and self-nucleation effects, respectively. The final ratio of the two kinds of crystal forms is a result of the competition between the two nucleation rates, which strongly depend on crystallization temperature. In this work, we have shown that careful design of novel self-nucleation protocols can yield evidence of the early stages of form II to form I transition, even when the degree of transformed crystals is below the limit of detection of conventional techniques sensitive to crystalline order (DSC, WAXD, and FTIR)
Delocalization Enhances Conductivity at High Doping Concentrations
Many applications of organic semiconductors require high electrical conductivities and hence high doping levels. Therefore, it is indispensable for effective material design to have an accurate understanding of the underlying transport mechanisms in this regime. In this study, own and literature experimental data that reveal a power-law relation between the conductivity and charge density of strongly p-doped conjugated polymers are combined. This behavior cannot consistently be described with conventional models for charge transport in energetically disordered materials. Here, it is shown that the observations can be explained in terms of a variable range hopping model with an energy-dependent localization length. A tight-binding model is used to quantitatively estimate of the energy-dependent localization length, which is used in an analytical variable range hopping model. In the limit of low charge densities, the model reproduces the well-known Mott variable range hopping behavior, while for high charge densities, the experimentally observed superlinear increase in conductivity with charge density is reproduced. The latter behavior occurs when the Fermi level reaches partially delocalized states. This insight can be anticipated to lead to new strategies to increase the conductivity of organic semiconductors
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