7,146 research outputs found
Cutting the Climate-Development Gordian Knot - Economic options in a politically constrained world
Combating climate change cannot but be a cooperative venture amongst nations. Together with the problem posed by the withdrawal of the US from the Kyoto Protocol, the key challenge for winning the battle is the involvement of developing countries in efforts to alter their GHGs emissions trends. This involvement is necessary technically but also politically to bring the largest emitter of the planet back on the battle field. In the first section we draw on history to outline the intellectual underpinning of North/South divide around climate affairs. In the second section we show the economic basis for a leverage effect between development and climate policies. The third section ventures to propose some guidance to develop a viable climate regime strong enough to support an ambitious effort to decarbonize economies and we show that the Kyoto framework, once re-interpreted and amended is not so far from this working drawing.climate policy; development
European Cyber Security System
Nowadays computer networks are widely spread in all spheres of human life.
That is why the problem of cyber security of mankind is of great importance. Today,
the European Union makes efforts to guarantee network safety in Europe by means of
increase its member states in power and international cooperation in cyber security,
including non-member countries, to prevent cyber crimes. Striving to join the
European Union, Ukraine is involved in the process of providing cyber security. This
paper examines the main strategies of EU standards in cyber security to be followed
by Ukraine as one of European countries
Defective hierarchical porous copper-based metal-organic frameworks synthesised via facile acid etching strategy
Introducing hierarchical pore structure to microporous materials such as
metal-organic frameworks (MOFs) can be beneficial for reactions where the rate
of reaction is limited by low rates of diffusion or high pressure drop. This
advantageous pore structure can be obtained by defect formation, mostly via
post-synthetic acid etching, which has been studied extensively on water-stable
MOFs. Here we show that a water-unstable HKUST-1 MOF can also be modified in a
corresponding manner by using phosphoric acid as a size-selective etching agent
and a mixture of dimethyl sulfoxide and methanol as a dilute solvent.
Interestingly, we demonstrate that the etching process which is time- and
acidity- dependent, can result in formation of defective HKUST-1 with extra
interconnected hexagonal macropores without compromising on the bulk
crystallinity. These findings suggest an intelligent scalable synthetic method
for formation of hierarchical porosity in MOFs that are prone to hydrolysis,
for improved molecular accessibility and diffusion for catalysis.Comment: 14 pages, 8 figure
Torque-Induced Rotational Dynamics in Polymers: Torsional Blobs and Thinning
By using the blob theory and computer simulations, we investigate the
properties of a linear polymer performing a stationary rotational motion around
a long impenetrable rod. In particular, in the simulations the rotation is
induced by a torque applied to the end of the polymer that is tethered to the
rod. Three different regimes are found, in close analogy with the case of
polymers pulled by a constant force at one end. For low torques the polymer
rotates maintaining its equilibrium conformation. At intermediate torques the
polymer assumes a trumpet shape, being composed by blobs of increasing size. At
even larger torques the polymer is partially wrapped around the rod. We derive
several scaling relations between various quantities as angular velocity,
elongation and torque. The analytical predictions match the simulation data
well. Interestingly, we find a "thinning" regime where the torque has a very
weak (logarithmic) dependence on the angular velocity. We discuss the origin of
this behavior, which has no counterpart in polymers pulled by an applied force.Comment: 30 pages, 8 figures, 1 TOC figure; video abstract at
https://youtu.be/LwicoSkh3m
Viscous photons in relativistic heavy ion collisions
Theoretical studies of the production of real thermal photons in relativistic
heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) are
performed. The space-time evolution of the colliding system is modelled using
MUSIC, a 3+1D relativistic hydrodynamic simulation, using both its ideal and
viscous versions. The inclusive spectrum and its azimuthal angular anisotropy
are studied separately, and the relative contributions of the different photon
sources are highlighted. It is shown that the photon v2 coefficient is
especially sensitive to the details of the microscopic dynamics like the
equation of state, the ratio of shear viscosity over entropy density, eta/s,
and to the morphology of the initial state.Comment: 15 pages, 12 figures. References updated and discussion adde
A weak lensing study of the Coma cluster
Due to observational constraints, dark matter determinations in nearby
clusters based on weak lensing are still extremely rare, in spite of their
importance for the determination of cluster properties independent of other
methods. We present a weak lensing study of the Coma cluster (redshift 0.024)
based on deep images obtained at the CFHT. After obtaining photometric
redshifts for the galaxies in our field based on deep images in the u (1x1
deg2), and in the B, V, R and I bands (42'x52'), allowing us to eliminate
foreground galaxies, we apply weak lensing calculations on shape measurements
performed in the u image. We derive a map of the mass distribution in Coma, as
well as the radial shear profile, and the mass and concentration parameter at
various radii. We obtain M_200c = 5.1+4.3-2.1 x10^14 Msun and
c_200c=5.0+3.2-2.5, in good agreement with previous measurements. With deep
wide field images it is now possible to analyze nearby clusters with weak
lensing techniques, thus opening a broad new field of investigation
Cutting the Climate-Development Gordian Knot - <br />Economic options in a politically constrained world
http://www.cesifo.deCombating climate change cannot but be a cooperative venture amongst nations. Together with the problem posed by the withdrawal of the US from the Kyoto Protocol, the key challenge for winning the battle is the involvement of developing countries in efforts to alter their GHGs emissions trends. This involvement is necessary technically but also politically to bring the largest emitter of the planet back on the battle field. In the first section we draw on history to outline the intellectual underpinning of North/South divide around climate affairs. In the second section we show the economic basis for a leverage effect between development and climate policies. The third section ventures to propose some guidance to develop a viable climate regime strong enough to support an ambitious effort to decarbonize economies and we show that the Kyoto framework, once re-interpreted and amended is not so far from this working drawing
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