3,619 research outputs found
Matching of analytical and numerical solutions for neutron stars of arbitrary rotation
We demonstrate the results of an attempt to match the two-soliton analytical
solution with the numerically produced solutions of the Einstein field
equations, that describe the spacetime exterior of rotating neutron stars, for
arbitrary rotation. The matching procedure is performed by equating the first
four multipole moments of the analytical solution to the multipole moments of
the numerical one. We then argue that in order to check the effectiveness of
the matching of the analytical with the numerical solution we should compare
the metric components, the radius of the innermost stable circular orbit
(), the rotation frequency and the
epicyclic frequencies . Finally we present some
results of the comparison.Comment: Contribution at the 13th Conference on Recent Developments in Gravity
(NEB XIII), corrected typo in of eq. 5 of the published versio
Quantitation of buried contamination by use of solvents
Experiments directed at determining the potential of reclaimed silicone polymers for reuse are described
Quantitation of buried contamination by use of solvents
Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided
Remote Sensing and Control of Phase Qubits
We demonstrate a remote sensing design of phase qubits by separating the
control and readout circuits from the qubit loop. This design improves
measurement reliability because the control readout chip can be fabricated
using more robust materials and can be reused to test different qubit chips.
Typical qubit measurements such as Rabi oscillations, spectroscopy, and
excited-state energy relaxation are presented.Comment: 3 pages, 4 figure
Covariation of vegetation and climate constrains present and future T/ET variability
The reliable partitioning of the terrestrial latent heat flux into evaporation (E) and transpiration (T) is important for linking carbon and water cycles and for better understanding ecosystem functioning at local, regional and global scales. Previous research revealed that the transpiration-to-evapotranspiration ratio (T/ET) is well constrained across ecosystems and is nearly independent of vegetation characteristics and climate. Here we investigated the reasons for such a global constancy in present-day T/ET by jointly analysing observations and process-based model simulations. Using this framework, we also quantified how the ratio T/ET could be influenced by changing climate. For present conditions, we found that the various components of land surface evaporation (bare soil evaporation, below canopy soil evaporation, evaporation from interception), and their respective ratios to plant transpiration, depend largely on local climate and equilibrium vegetation properties. The systematic covariation between local vegetation characteristics and climate, resulted in a globally constrained value of T/ET = ~70 ± 9% for undisturbed ecosystems, nearly independent of specific climate and vegetation attributes. Moreover, changes in precipitation amounts and patterns, increasing air temperatures, atmospheric CO2 concentration, and specific leaf area (the ratio of leaf area per leaf mass) was found to affect T/ET in various manners. However, even extreme changes in the aforementioned factors did not significantly modify T/ET
An ecohydrological journey of 4500 years reveals a stable but threatened precipitation–groundwater recharge relation around Jerusalem
Groundwater is a key water resource in semiarid and seasonally dry regions around the world, which is replenished
by intermittent precipitation events and mediated by vegetation, soil, and regolith properties. Here, a climate
reconstruction of 4500 years for the Jerusalem region was used to determine the relation between climate, vegetation,
and groundwater recharge. Despite changes in air temperature and vegetation characteristics, simulated recharge
remained linearly related to precipitation over the entire analyzed period, with drier decades having lower rates
of recharge for a given annual precipitation due to soil memory effects. We show that in recent decades, the lack of
changes in the precipitation–groundwater recharge relation results from the compensating responses of vegetation
to increasing CO2, i.e., increased leaf area and reduced stomatal conductance. This multicentury relation is
expected to be modified by climate change, with changes up to −20% in recharge for unchanged precipitation,
potentially jeopardizing water resource availability
Origin and Suppression of Magnetic Flux Noise
Magnetic flux noise is a dominant source of dephasing and energy relaxation
in superconducting qubits. The noise power spectral density varies with
frequency as with and spans 13 orders of
magnitude. Recent work indicates that the noise is from unpaired magnetic
defects on the surfaces of the superconducting devices. Here, we demonstrate
that adsorbed molecular O is the dominant contributor to magnetism in
superconducting thin films. We show that this magnetism can be suppressed by
appropriate surface treatment or improvement in the sample vacuum environment.
We observe a suppression of static spin susceptibility by more than an order of
magnitude and a suppression of magnetic flux noise power spectral density
by more than a factor of 5. These advances open the door to realization of
superconducting qubits with improved quantum coherence.Comment: Main text: 5 pages, 4 figures. Supplement: 8 pages, 6 figure
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