48 research outputs found
Analysis of Parametric Oscillatory Instability in Power Recycled LIGO Interferometer
We present the analysis of a nonlinear effect of parametric oscillatory
instability in power recycled LIGO interferometer with the Fabry-Perot (FP)
cavities in the arms. The basis for this effect is the excitation of the
additional (Stokes) optical mode and the mirror elastic mode, when the optical
energy stored in the main FP cavity main mode exceeds the certain threshold and
the frequencies are related so that sum of frequencies of Stokes and elastic
modes are approximately equal to frequencyof main mode. The presence of
anti-Stokes modes (with frequency approximately equal to sum of frequencies of
main and elastic modes) can depress parametric instability. However, it is very
likely that the anti-Stokes modes will not compensate the parametric
instability completely.Comment: 9 pages, 2 figures. submitted to Physics Letters
Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre
We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies
An electrochromic device combining polypyrrole and WO3 .2. solid-state device with polymeric electrolyte
In this work we describe the assembling of a solid-state electrochromic device using, as active materials, an organic conductive polymer and a transition metal oxide. The optically active materials were dodecylsulfate doped polypyrrole and tungsten oxide. The substrates used were glass slides coated with tin-doped indium oxide and the solid elastomeric electrolyte was the copolymer of ethylene oxide and epichlorohydrin containing lithium perchlorate. Initially, we studied separately the materials used to assemble the device and, in sequence, we assembled and characterized the complete devices. The thickness of the polypyrrole and the electrolyte films were varied to obtain the highest chromatic contrast, stability over a high number of redox cycles, and short response times. The characterizations were made by spectroelectrochemistry using the techniques of cyclic voltammetry and chronoamperometry: To illustrate the results obtained, we describe two devices with different polypyrrole and electrolyte film thicknesses. The chromatic contrast in the visible and near-infrared wavelength range is 30% and the electric and optical properties of the devices remain unchanged after 1.5 X 10(4) double potential chronoamperometric steps. (C) 1997 Elsevier Science S.A.4354167121722
An electrochromic device combining polypyrrole and WO3 .1. Liquid electrolyte
In this work we assembled an electrochromic device using as active materials an organic conductive polymer and a transition metal oxide. We studied the materials used to assemble the device separately, and in complete devices. These materials were: polypyrrole doped with dodecylsulfate and tungsten oxide. The substrates used were glass slides coated with tin doped indium oxide, and the electrolyte was a propylene carbonate solution of lithium perchlorate. We adjusted the charge balance and the chromatic contrast of the devices by controlling the thickness of the polypyrrole films. To illustrate the results obtained, we describe two devices with different polypyrrole film thicknesses. The chromatic contrast in the visible and near-infrared wavelength range is 40% and the electrical and optical properties of the devices remain unchanged after 10(4) double potential chronoamperometric steps. Copyright (C) 1996 Elsevier Science Ltd41182805281
A new configuration of the solid-state battery: magnesium polymer proton conductor gold, based on the use of poly(o-methoxyaniline)
A solid-state battery was constructed by interfacing a pressed pellet of poly(o-methoxyaniline), in the emeraldine form with p-toluene sulfonic acid as doping agent, to a magnesium electrode covered with a film of magnesium perchlorate; the contact on the poly(o-methoxyaniline) was done by means of a gold electrode. The so-obtained cell, Mg I magnesium perchlorate I poly(o-methoxyaniline) I gold, was able to supply energy with a power depending on discharge current and on environmental humidity. Values of power up to 2.5 mW cm(-2) at discharge currents of about 2 mA cm(-2) were reached. (C) 1997 Elsevier Science S.A.901313
Leptin administration to overweight and obese subjects for 6 months increases free leptin concentrations but does not alter circulating hormones of the thyroid and IGF axes during weight loss induced by a mild hypocaloric diet.
NGM282 for Treatment of Patients With Primary Biliary Cholangitis: A Multicenter, Randomized, Double Blind Placebo Controlled Trial
Patients with primary biliary cholangitis (PBC) who had an inadequate response to ursodiol have few treatment options. Alkaline phosphatase (ALP) and bilirubin levels correlate with the risk of liver transplant or death in PBC patients. Fibroblast growth factor (FGF) 19 is a hormone that acts directly in the liver to regulate bile acid synthesis. We evaluated NGM282, an engineered analogue of FGF19, for the treatment of PBC. In this 28-day, double-blind, placebo-controlled phase 2 trial, 45 PBC patients who had an inadequate response to ursodiol were randomly assigned 1:1:1 to receive subcutaneous daily doses of either NGM282 at 0.3 mg (n = 14), 3 mg (n = 16), or placebo (n = 15). The primary endpoint was a change in ALP from baseline after 28 days of treatment. At day 28, ALP was significantly reduced with NGM282 treatment at both 0.3 mg (least-squares mean -51.0 IU/L [standard error (SE) 15.4]) and 3 mg (-66.0 IU/L [SE 16.0]) versus placebo (3.3 IU/L [SE 14.8]), with least-squares mean differences of -54.3 IU/L (95% confidence interval -104.2 to -4.5; P = 0.0149) and -69.3 IU/L (95% confidence interval -120.5 to -18.3; P = 0.0030), respectively. Fifty percent (7 of 14) of patients receiving NGM282 0.3 mg and 46% (6 of 13) of those receiving NGM282 3mg achieved 15% or greater reduction in ALP levels from baseline, compared with 7% (1 of 15) of patients receiving placebo. NGM282 also significantly reduced serum concentrations of transaminases and immunoglobulins. Most adverse events were grade 1 (mild) to grade 2 (moderate) in severity, with gastrointestinal disorders more frequent in the NGM282 treatment groups. No worsening of pruritus was observed with NGM282 treatment. Conclusion: NGM282 administered for 28 days resulted in significant improvements in ALP and transaminase levels compared with placebo, with an acceptable safety profile in patients with PBC. (Hepatology Communications 2018; 00:000-000)