1,630,462 research outputs found
Experimentally measured thermal masses of adsorption heat exchangers
The thermal masses of components influence the performance of many adsorption heat pump systems. However, typically when experimental adsorption systems are reported, data on thermal mass are missing or incomplete. This work provides original measurements of the thermal masses for experimental sorption heat exchanger hardware. Much of this hardware was previously reported in the literature, but without detailed thermal mass data. The data reported in this work are the first values reported in the literature to thoroughly account for all thermal masses, including heat transfer fluid. The impact of thermal mass on system performance is also discussed, with detailed calculation left for future work. The degree to which heat transfer fluid contributes to overall effective thermal mass is also discussed, with detailed calculation left for future work. This work provides a framework for future reporting of experimental thermal masses. The utilization of this framework will enrich the data available for model validation and provide a more thorough accounting of adsorption heat pumps
Experimentally exploring compressed sensing quantum tomography
In the light of the progress in quantum technologies, the task of verifying
the correct functioning of processes and obtaining accurate tomographic
information about quantum states becomes increasingly important. Compressed
sensing, a machinery derived from the theory of signal processing, has emerged
as a feasible tool to perform robust and significantly more resource-economical
quantum state tomography for intermediate-sized quantum systems. In this work,
we provide a comprehensive analysis of compressed sensing tomography in the
regime in which tomographically complete data is available with reliable
statistics from experimental observations of a multi-mode photonic
architecture. Due to the fact that the data is known with high statistical
significance, we are in a position to systematically explore the quality of
reconstruction depending on the number of employed measurement settings,
randomly selected from the complete set of data, and on different model
assumptions. We present and test a complete prescription to perform efficient
compressed sensing and are able to reliably use notions of model selection and
cross-validation to account for experimental imperfections and finite counting
statistics. Thus, we establish compressed sensing as an effective tool for
quantum state tomography, specifically suited for photonic systems.Comment: 12 pages, 5 figure
How can we test seesaw experimentally?
The seesaw mechanism for the small neutrino mass has been a popular paradigm,
yet it has been believed that there is no way to test it experimentally. We
present a conceivable outcome from future experiments that would convince us of
the seesaw mechanism. It would involve a variety of data from LHC, ILC,
cosmology, underground, and low-energy flavor violation experiments to
establish the case.Comment: 5 pages, 4 figure
Experimentally Witnessing the Quantumness of Correlations
The quantification of quantum correlations (other than entanglement) usually
entails laboured numerical optimization procedures also demanding quantum state
tomographic methods. Thus it is interesting to have a laboratory friendly
witness for the nature of correlations. In this Letter we report a direct
experimental implementation of such a witness in a room temperature nuclear
magnetic resonance system. In our experiment the nature of correlations is
revealed by performing only few local magnetization measurements. We also
compare the witness results with those for the symmetric quantum discord and we
obtained a fairly good agreement
Experimentally Probing the Shape of Extra Dimensions
In brane world scenarios in which only gravity can propagate in the extra
dimensions, effects on the gravitational force may be experimentally testable
if there are two or three large extra dimensions. The strength of the force at
distances smaller than the compactification radius will be sensitive to the
volume of the extra dimensions, but the determination of the shape requires
knowing the gravitational potential at intermediate scales. We determine the
dependence of the potential vs. distance as a function of both the relative
size of the extra dimensions and the possible angle between the extra
dimensional unit vectors, and show that high precision measurements of the
gravitational force will allow the determination of the shape of the extra
dimensions.Comment: Much more pedagogical version. Version to be published in the
American Journal of Physic
Novel Experimentally Observed Phenomena in Soft Matter
Soft materials such as colloidal suspensions, polymer solutions and liquid
crystals are constituted by mesoscopic entities held together by weak forces.
Their mechanical moduli are several orders of magnitude lower than those of
atomic solids. The application of small to moderate stresses to these materials
results in the disruption of their microstructures. The resulting flow is
non-Newtonian and is characterised by features such as shear rate-dependent
viscosities and non-zero normal stresses. This article begins with an
introduction to some unusual flow properties displayed by soft matter.
Experiments that report a spectrum of novel phenomena exhibited by these
materials, such as turbulent drag reduction, elastic turbulence, the formation
of shear bands and the existence of rheological chaos, flow-induced
birefringence and the unusual rheology of soft glassy materials, are reviewed.
The focus then shifts to observations of the liquid-like response of granular
media that have been subjected to external forces. The article concludes with
examples of the patterns that emerge when certain soft materials are vibrated,
or when they are displaced with Newtonian fluids of lower viscosities.Comment: 30 pages, 11 figures, invited review article, supplementary videos
may be obtained from the journal websit
Multi-Channel Reflectors: Versatile Performance Experimentally Tested
We investigate multi-channel reflectors, such as a three-channel power
splitter and a five-channel isolating mirror. These metasurface reflectors are
able to control reflections from and into several directions while possessing a
flat surface. We design, fabricate, and experimentally study these new devices,
confirming that the performance is nearly perfect.Comment: 2 page
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