20 research outputs found
Non-destructive testing of works of art by stimulated by infrared thermography: PPT interest
Short abstract Within the framework of the cultural heritage conservation, stimulated infrared thermography has already demonstrated its efficiency. However, sometimes, the different colors of the paint layer can lead to artifacts of detection. In this work, we show theoretically and experimentally that the combination of a PPT analysis and of the stimulated infrared thermography allows a significant reduction of this disturbing optical effect
Stimulated infrared thermography applied to the local thermal characterization of fresco
Abstract In this work, we present a new method for estimating the local thermal diffusivity of fresco. This method uses a temporal analysis of the thermal response of a work of art submitted to a local laser excitation. First, we present the principle of the estimation method. Then, we show theoretically with the help of numerical simulations, the feasibility of the method. Finally, we show experimentally, that the method allows a good estimation of the thermal diffusivity of an academic plaster sample and of an academic fresco
Duvaut : Contribution to the local thermophysical characterization of murals paintings of the inheritance by stimulated infra-red thermography, proc of QIRT
Abstract The object of this work is to approach the possibilities of stimulated infrared thermography for in situ measurement of thermal diffusivity of mural paintings of the inheritance. We present first the principle of the method. We show then the feasibility of the measurement, using theoretical simulations. Finally, we show that the method allows a good estimation of the thermal diffusivity of a partial copy of the "Saint Christophe" of the Campana collection in the Louvre
Reliable 50Gb/s silicon photonics platform for next-generation data center optical interconnects
The next generations of data centers require a scalable optical transceiver technology. In this paper we present a silicon photonics platform supporting single-channel data rates of 50Gb/s and above. Advanced process options include 50GHz GeSi electro-absorption modulators, high efficiency thermo-optic phase shifters with P-pi <5mW and silicon carrier depletion-based phase-shifters supporting Mach-Zehnder and micro-ring modulators. The performance and reliability of the key library components such as modulators, detectors, fiber couplers and heaters is described
Legacies of state-building and political fragility in conflict-ridden Yemen: Understanding civil service change and contemporary challenges
Pre‐Bond Testing Through Direct Probing of Large‐Array Fine‐Pitch Micro‐Bumps*
In order to obtain acceptable compound stack yields for 2.5D‐ and 3D‐stacked integrated circuits (SICs), there is a need to test the constituting dies before stacking. The non‐bottom dies of these stacks have their functional access exclusively through large arrays of fine‐pitch micro‐bumps, which are too dense for conventional probe technology. A common approach to obtain pre‐bond test access is to equip these dies with dedicated pre‐bond probe pads, which comes with drawbacks such as increased silicon area and test application time and reduced interconnect performance. In order to avoid the many drawbacks of dedicated pre‐bond probe pads, we advocate the usage of advanced probe technology that allows to directly probe on these micro‐bumps. This chapter reports on the technical feasibility of this approach. The economical feasibility is addressed in Chapter 9
Efficacy and safety of the investigational complement C5 inhibitor zilucoplan in patients hospitalized with COVID-19 : an open-label randomized controlled trial
Background The efficacy and safety of complement inhibition in COVID-19 patients is unclear. Methods A multicenter randomized controlled, open-label trial. Hospitalized COVID-19 patients with signs of systemic inflammation and hypoxemia (PaO2/FiO(2) below 350 mmHg) were randomized (2:1 ratio) to receive standard of care with or without the C5 inhibitor zilucoplan daily for 14 days, under antibiotic prophylaxis. The primary outcome was improvement in oxygenation at day 6 and 15. Results 81 patients were randomly assigned to zilucoplan (n = 55) or the control group (n = 26). 78 patients were included in the safety and primary analysis. Most were men (87%) and the median age was 63 years. The mean improvement in PaO2/FiO(2) from baseline to day 6 was 56.4 mmHg in the zilucoplan group and 20.6 mmHg in the control group (mean difference + 35.8; 95% confidence interval (CI) - 9.4 to 80.9; p = 0.12), an effect also observed at day 15. Day 28 mortality was 9% in the zilucoplan and 21% in the control group (odds ratio 0.4; 95% CI 0.1 to 1.5). At long-term follow up, the distance walked in a 6-min test was 539.7 m in zilucoplan and 490.6 m in the control group (p = 0.18). Zilucoplan lowered serum C5b-9 (p < 0.001) and interleukin-8 (p = 0.03) concentration compared with control. No relevant safety differences between the zilucoplan and control group were identified. Conclusion Administration of zilucoplan to COVID-19 patients in this proof-of-concept randomized trial was well tolerated under antibiotic prophylaxis. While not reaching statistical significance, indicators of respiratory function (PaO2/FiO(2)) and clinical outcome (mortality and 6-min walk test) suggest that C5 inhibition might be beneficial, although this requires further research in larger randomized studies
Effects of Annealing Temperature on the Electric Properties of 0.94(Na0.5Bi0.5)TiO3–0.06BaTiO3 Ferroelectric Thin Film
Evaluation of damages induced by Ga<su>+</sup> - focused ion beam in piezoelectric nanostructures
The impact of Ga+-focused ion beam (FIB) about functional properties of continuous and nanostructured piezoelectric thin films of lead zirconate titanate (Pb(ZrxTi1-x)O3) was investigated. A suitable way to fabricate piezoelectric nanocapacitors was studied, based on the amorphous or crystallized state of the film before etching. Strong modification of structural and electrical behavior for area exposed to ion irradiation is observed when the film is etched in the crystallized state. Both the implantation of Ga+ ions and the film amorphization highlighted by Raman spectroscopy and Kelvin force microscopy analyses can explain this result. The piezoactivity detected by piezoresponse force microscopy is fully destroyed even after a post-annealing treatment. In the case of amorphous etched film, no significant degradation is observed. The latter process is used to successfully fabricate Pb(ZrxTi1-x)O3-based nanocapacitors by means of FIB method. In 50-nm-size capacitors, the local electromechanical behavior is measured at similar level that the one obtained for the un-etched film, evidencing no manifest sidewall effect or FIB-induced damages. This further evidences that amorphous FIB lithography process can reduce the etching damages, demonstrating this is an effective alternative method and very beneficial to pattern such low-dimensional structures, which is a significant result in view of the development of functional nanostructures in the field of nanoelectromechanical systems applications