1,108 research outputs found
Description of self-synchronization effects in distributed Josephson junction arrays using harmonic analysis and power balance
Power generation and synchronisation in Josephson junction arrays have
attracted attention for a long time. This stems from fundamental interest in
nonlinear coupled systems as well as from potential in practical applications.
In this paper we study the case of an array of junctions coupled to a
distributed transmission line either driven by an external microwave or in a
self-oscillating mode. We simplify the theoretical treatment in terms of
harmonic analysis and power balance. We apply the model to explain the large
operation margins of SNS- and SINIS-junction arrays. We show the validity of
the approach by comparing with experiments and simulations with
self-oscillating es-SIS junction arrays.Comment: 5 pages, 3 figure
An Analytical Evaluation of Distortion-Induced Fatigue in Steel Bridges
Multi-girder steel bridges designed prior to the mid-1980's, have developed cracks due to distortion-induced fatigue. An analytical evaluation was conducted to better understand the effects of bridge configurations and common retrofits on distortion-induced fatigue, as quantified by hot spot stress in web gap regions. Results are described herein and present relative distortion-induced fatigue susceptibility of multi-girder bridges with varied skew angle, cross frame spacing, bracing configuration, and cross frame stiffness as well as regions within each variation where cracking is most likely to occur. Performance of retrofit techniques was also compared and included positive attachment, a slotted connection stiffener, a back-up stiffener, and cross frame removal with each implemented both locally and globally. In addition, influence surfaces were generated and analyzed for three bridge configurations to better understand the relationship between load placement and distortion-induced fatigue related stresses. It is hoped that this research will benefit bridge engineers working to identify and extend the fatigue life of bridges susceptible to distortion-induced fatigue
Nondestructive Ultrasonic Characterization of the Orientation Distribution of Short-Fiber Composites
The ease of fabrication and relatively low cost of composites containing short glass or ceramic fibers embedded in a polymer or metal matrix has made them attractive candidates for a wide range of applications. The preferential alignment, or misalignment depending on one’s view, of the short fibers results in an overall texture of the composite and strongly influences its mechanical and physical response, for example, stiffness, conductivity, strength, and so on. The orientation of the short fibers depends strongly on the processing conditions. From a process-control viewpoint, it is imperative to determine if a composite component has adequate strength, stiffness, and so on, and it is preferable to obtain this information nondestructively. In short-fiber reinforced composites, the orientation distribution of the short fibers is the most significant variable that determines these overall properties. Thus its determination is essential
Monopolelike probes for quantitative magnetic force microscopy: calibration and application
A local magnetization measurement was performed with a Magnetic Force
Microscope (MFM) to determine magnetization in domains of an exchange coupled
[Co/Pt]/Co/Ru multilayer with predominant perpendicular anisotropy. The
quantitative MFM measurements were conducted with an iron filled carbon
nanotube tip, which is shown to behave like a monopole. As a result we
determined an additional in-plane magnetization component of the multilayer,
which is explained by estimating the effective permeability of the sample
within the \mu*-method.Comment: 3 pages, 3 figure
RSFQ devices with selective dissipation for quantum information processing
We study the possibility to use frequency dependent damping in RSFQ circuits
as means to reduce dissipation and consequent decoherence in RSFQ/qubit
circuits. We show that stable RSFQ operation can be achieved by shunting the
Josephson junctions with an circuit instead of a plain resistor. We derive
criteria for the stability of such an arrangement, and discuss the effect on
decoherence and the optimisation issues. We also design a simple flux generator
aimed at manipulating flux qubits
First Calorimetric Measurement of OI-line in the Electron Capture Spectrum of Ho
The isotope Ho undergoes an electron capture process with a
recommended value for the energy available to the decay, , of about
2.5 keV. According to the present knowledge, this is the lowest
value for electron capture processes. Because of that, Ho is the best
candidate to perform experiments to investigate the value of the electron
neutrino mass based on the analysis of the calorimetrically measured spectrum.
We present for the first time the calorimetric measurement of the atomic
de-excitation of the Dy daughter atom upon the capture of an electron
from the 5s shell in Ho, OI-line. The measured peak energy is 48 eV.
This measurement was performed using low temperature metallic magnetic
calorimeters with the Ho ion implanted in the absorber.
We demonstrate that the calorimetric spectrum of Ho can be measured
with high precision and that the parameters describing the spectrum can be
learned from the analysis of the data. Finally, we discuss the implications of
this result for the Electron Capture Ho experiment, ECHo, aiming to
reach sub-eV sensitivity on the electron neutrino mass by a high precision and
high statistics calorimetric measurement of the Ho spectrum.Comment: 5 pages, 3 figure
Herschel observations of EXtra-Ordinary Sources: Analysis of the HIFI 1.2 THz Wide Spectral Survey Toward Orion KL II. Chemical Implications
We present chemical implications arising from spectral models fit to the
Herschel/HIFI spectral survey toward the Orion Kleinmann-Low nebula (Orion KL).
We focus our discussion on the eight complex organics detected within the HIFI
survey utilizing a novel technique to identify those molecules emitting in the
hottest gas. In particular, we find the complex nitrogen bearing species
CHCN, CHCN, CHCN, and NHCHO systematically
trace hotter gas than the oxygen bearing organics CHOH, CHOH,
CHOCH, and CHOCHO, which do not contain nitrogen. If these
complex species form predominantly on grain surfaces, this may indicate
N-bearing organics are more difficult to remove from grain surfaces than
O-bearing species. Another possibility is that hot (T300 K)
gas phase chemistry naturally produces higher complex cyanide abundances while
suppressing the formation of O-bearing complex organics. We compare our derived
rotation temperatures and molecular abundances to chemical models, which
include gas-phase and grain surface pathways. Abundances for a majority of the
detected complex organics can be reproduced over timescales 10
years, with several species being under predicted by less than 3.
Derived rotation temperatures for most organics, furthermore, agree reasonably
well with the predicted temperatures at peak abundance. We also find that
sulfur bearing molecules which also contain oxygen (i.e. SO, SO, and OCS)
tend to probe the hottest gas toward Orion KL indicating the formation pathways
for these species are most efficient at high temperatures.Comment: 31 pages, 6 figures, 1 Table, accepted to the Astrophysical Journa
Four cases of erysipelas-like inflammation in patients with metastatic melanoma treated with checkpoint inhibitors
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Client Weight as a Barrier to Non-Biased Clinical Judgment
A sample of 95 Christian and 68 Non-Christian mental health professionals were given a picture of either an overweight or average-weight male or female client and a generic case vignette. Participants were asked to make clinical judgments of pathology and client attributions for the pictured client. Results indicated that mental health professionals ascribe more pathology and negative attributes to obese clients than to average-weight clients. In addition, Christian mental health professionals are just as likely as non-Christians to ascribe more negative attributes to obese clients. Ways to remove barriers to unbiased psychotherapy and deal with countertransference issues are discussed from a Christian perspective
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