10 research outputs found
Shear-Modulus Investigations of Monohydroxy Alcohols: Evidence for a Short-Chain-Polymer Rheological Response
In addition to the ubiquitous structural relaxation of viscous supercooled
liquids, monohydroxy alcohols and several other hydrogen-bonded systems display
a strong single-exponential electrical low-frequency absorption. So far, this
so-called Debye process could be observed only using dielectric techniques.
Exploiting a combination of broad-band and high-resolution rheology experiments
for three isomeric octanols, unambiguous mechanical evidence for the Debye
process is found. Its spectral signature is similar to the viscoelastic
fingerprint of small-chain polymers, enabling us to estimate the effective
molecular weight for the supramolecular structure formed by the studied
monohydroxy alcohols. This finding opens the venue for the application of
further non-dielectric techniques directed at unraveling the microscopic nature
of the Debye process and for an understanding of this phenomenon in terms of
polymer concepts.Comment: 12 pages, 4 figure
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
Recent developments on inspection procedures for infrastructure using UAVs
Recently, collapsed bridges, belonging to infrastructure networks, evidence the needs of reliable monitoring and inspection routines. Inspections can be a challenge operation in sites difficult to access; specially trained staff like industrial climbers perform the inspection routine, eventually involving large underbridge units, elevating platforms, or other specialized equipment. In addition, since the inspections are performed manually, the outcomes mainly rely on inspector confidence and experience. This paper discuss the possibility of using unmanned aerial vehicles for monitoring and inspection of transport infrastructure