Literature on ECAP generally deals with room temperature or high-temperature deformation regimes. Very few data on low-temperature SPD processes have been published. This study presents some ...experimental results on the effect of cryogenic treatment prior to ECAP-BC on microstructure modification, mechanical response, and corrosion behaviour of an AA6012 Al-Mg-Si-Pb alloy. This type of Pb-bearing AA6000-series alloy, is produced and used for its marked post-extrusion machinability. The mechanical properties were inferred by nanoindentation to measure hardness, H, and local elastic modulus, Er. These data were presented in form of maps to account for the whole H and Er evolution with cumulative strain. The experimental results showed significant microstructure differences between the cryogenic treated ECAP condition and the conventional ECAP at room temperature. These differences were also correlated with electron microscopy inspections, XRD. Finally, the cryogenic treatment prior ECAP also affected the alloy corrosion behaviour.
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Advanced Virgo is the project to upgrade the Virgo interferometric detector of gravitational waves, with the aim of increasing the number of observable galaxies (and thus the detection rate) by three ...orders of magnitude. The project is now in an advanced construction phase and the assembly and integration will be completed by the end of 2015. Advanced Virgo will be part of a network, alongside the two Advanced LIGO detectors in the US and GEO HF in Germany, with the goal of contributing to the early detection of gravitational waves and to opening a new window of observation on the universe. In this paper we describe the main features of the Advanced Virgo detector and outline the status of the construction.
The Advanced Virgo monolithic fused silica suspension Aisa, D.; Aisa, S.; Campeggi, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2016, Letnik:
824
Journal Article
Recenzirano
The detection of gravitational waves is one of the most challenging prospects faced by experimental physicists. Suspension thermal noise is an important noise source at operating frequencies between ...approximately 10 and 30Hz, and represents a limit to the sensitivity of the ground based interferometric gravitational wave detectors. Its effects can be reduced by minimizing the losses and by optimizing the geometry of the suspension fiber as well as its attachment system. In this proceeding we will describe the mirrors double stage monolithic suspension system to be used in the Advanced Virgo (AdV) detector. We also present the results of the thermal noise study, performed with the help of a finite elements model, taking into account the precise geometry of the fibers attachment systems on the suspension elements. We shall demonstrate the suitability of this suspension for installation in AdV.
•Suspension system design for the test masses of the gravitational wave detectors.•Finite element model studies.•Suspension thermal noise studies.
Gravitational waves (GWs) were observed for the first time in 2015, one century after Einstein predicted their existence. There is now growing interest to extend the detection bandwidth to low ...frequency. The scientific potential of multi-frequency GW astronomy is enormous as it would enable to obtain a more complete picture of cosmic events and mechanisms. This is a unique and entirely new opportunity for the future of astronomy, the success of which depends upon the decisions being made on existing and new infrastructures. The prospect of combining observations from the future space-based instrument LISA together with third generation ground based detectors will open the way toward multi-band GW astronomy, but will leave the infrasound (0.1-10 Hz) band uncovered. GW detectors based on matter wave interferometry promise to fill such a sensitivity gap. We propose the European Laboratory for Gravitation and Atom-interferometric Research (ELGAR), an underground infrastructure based on the latest progress in atomic physics, to study space-time and gravitation with the primary goal of detecting GWs in the infrasound band. ELGAR will directly inherit from large research facilities now being built in Europe for the study of large scale atom interferometry and will drive new pan-European synergies from top research centers developing quantum sensors. ELGAR will measure GW radiation in the infrasound band with a peak strain sensitivity of 3.3×10−22/Hz at 1.7 Hz. The antenna will have an impact on diverse fundamental and applied research fields beyond GW astronomy, including gravitation, general relativity, and geology.
Abstract
Background
The safety of intracoronary physiology guided coronary revascularization in patients with diabetes mellitus is not well established.
Purpose
The aim of this work is to assess the ...risk of vessel oriented cardiovascular events (VOCE) in patients with and without diabetes mellitus (DM) who underwent physiology-guided coronary revascularization. Moreover, we sought to identify clinical features associated with increased risk of adverse outcomes among patients with DM particularly when coronary intervention was deferred based on intracoronary functional assessment.
Methods
This is a retrospective analysis of a multicenter registry of patients evaluated with fractional flow reserve and/or non-hyperaemic pressure ratio. The primary endpoint was a composite of VOCE including cardiac death, vessel-related myocardial infarction (MI), and ischemia-driven target vessel revascularization (TVR).
Results
A large cohort of 2828 patients and 3353 coronary lesions with and without DM was analysed to assess the risk of VOCE at long-term follow up (23, interquartile range 14-36 months). The primary endpoint occurred in 222 (6.6%) coronary lesions without difference between patients with and without DM (7.8% vs. 6.1%, P=0.078). Diabetes was not associated with the primary endpoint (adjusted hazard ratio, aHR, 1.20, 95% CI 0.89-1.61, P=0.226) or with its individual components. Conversely, insulin-dependent diabetes mellitus (IDDM) demonstrated an increased risk of VOCE (aHR 1.76, 95% CI 1.07-2.91, P=0.027). In particular, IDDM was independently associated with ischemia-driven TVR (aHR 2.13, 95% CI 1.22-3.72, P=0.008) but not with vessel-oriented MI and cardiac death.
Myocardial revascularization was deferred in 2316 (69%) coronary lesions without difference between patients with and without DM (68.8% vs. 69.2%, P=0.820). In multivariable analysis, lesion localization in the proximal segment of the coronary artery (aHR 2.20, 95% CI 1.33-3.63, P=0.002), abnormal coronary physiology (aHR 5.95, 95% CI 2.27-15.59, P<0.0001) and IDDM (aHR 2.77, 95% CI 1.11-6.93, P=0.029) were independently associated with the risk of VOCE in the shared frailty Cox regression model. Conversely, overall DM was not associated with the primary endpoint (HR 1.39, 95% CI 0.98-1.98, P=0.069). Moreover, in patients with DM and deferred coronary lesions, lesion localization on the left anterior descending artery (aHR 3.13, 95%CI 1.31-7.51, P=0.010) and IDDM (aHR 2.47 95% CI 1.29-4.73, p=0.006) were associated with increased risk of VOCE after adjustment for clinical confounders.
Conclusion
Patients with non-IDDM and coronary lesions assessed with coronary physiology demonstrated low risk of VOCE at long-term follow up, similar to the risk of patients without DM. Conversely, IDDM represents a subgroup at high-risk of vessel-related adverse events and require close monitoring at follow up, even in presence of non-ischemic findings at coronary functional assessment.Overall cohortDeferred cohort
Abstract
Objectives
Our study sought to investigate the role of invasive hemodynamic monitoring during Transcatheter Edge to Edge Repair (TEER) procedure on top of transesophageal echocardiographic ...(TEE) guidance.
Background
Direct hemodynamic impact of residual MR after TEER is not always univocally measured by TEE assessment alone. When analyzing TEER procedure result operators often encounter discrepancy between TEE guidance and invasive hemodynamic monitoring.
Methods
We analyzed 78 patients with moderate-to-severe or severe mitral regurgitation (MR) who underwent TEER. Mitral pulse Pressure Fraction (MPF) was extracted from intraprocedural continuous left atrial pressure monitoring. 23 patients with the same grade of MR not undergoing TEER were included as a control group.
Results
TEER had a significant impact reducing MR burden on both TEE guidance and invasive hemodynamic monitoring. Post-TEER MPF was significantly reduced compared to both pre-TEER setting (p < 0.001) and control group (p = 0.004). MR reduction assessed by TEE guidance was not found to be correlated with improved clinical and functional status at follow-up as assessed by New York Heart Association (NYHA) classification (p = 0.424) and 12-items Kansas City Cardiomyopathy Questionnaire (KCCQ) (p = 0.1). On the contrary, a greater reduction in MPF was associated with a significant amelioration of both NYHA classification (p = 0.003) and 12-items KCCQ (p<0.001) during the follow-up period.
Conclusions
MPF provides an immediate estimate of the real hemodynamic impact of MR and can offer a prompt prediction of the functional improvement after TEER.
Advanced gravitational wave interferometers, currently under realization, will soon permit the detection of gravitational waves from astronomical sources. To open the era of precision gravitational ...wave astronomy, a further substantial improvement in sensitivity is required. The future space-based Laser Interferometer Space Antenna and the third-generation ground-based observatory Einstein Telescope (ET) promise to achieve the required sensitivity improvements in frequency ranges. The vastly improved sensitivity of the third generation of gravitational wave observatories could permit detailed measurements of the sources' physical parameters and could complement, in a multi-messenger approach, the observation of signals emitted by cosmological sources obtained through other kinds of telescopes. This paper describes the progress of the ET project which is currently in its design study phase.
Scientific objectives of Einstein Telescope Abernathy, M; Ajith, P; Astone, P ...
Classical and quantum gravity,
06/2012, Letnik:
29, Številka:
12
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The advanced interferometer network will herald a new era in observational astronomy. There is a very strong science case to go beyond the advanced detector network and build detectors that operate ...in a frequency range from 1 Hz to 10 kHz, with sensitivity a factor 10 better in amplitude. Such detectors will be able to probe a range of topics in nuclear physics, astronomy, cosmology and fundamental physics, providing insights into many unsolved problems in these areas.
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