Lasers are adequate tools in the processing and characterization of materials. The Applied Superconductivity group at the Aragón Materials Science Institute has been applying different laser techniques in the processing, machining and characterization of bulk high temperature superconductors for high power applications. Textured bulk Bi-2212 superconductors have been obtained using laser melting zone techniques. We have produced thin bars, monoliths and coatings on metallic and ceramic substrates. Ablation techniques have been used to machine the samples with the required shape for technological applications. And finally, optical techniques have been used as non-destructive experiments to detect the location of hot-spots and the positions where environmental degradation starts.
This paper presents the first application of digital speckle pattern interferometry (DSPI) to detect inhomogeneous heat generation on a superconducting ceramic at cryogenic temperatures. The light scattered by the object is recorded with a CCD camera at the same time as a smooth reference beam. Comparison of two non-simultaneous frames provides information about the out-of-plane deformation field. Spatial phase shifting is used in order to get a good quality fringe pattern. The technique has been applied as a non-destructive evaluation of the performance of ceramic high temperature superconducting materials. DSPI allows the determination of the point where a hot spot will be generated with heating levels that do not deteriorate the sample properties. An excellent agreement between DSPI hot spot location and the position of the melting point that appeared in a destructive experiment has been obtained.
Digital speckle pattern interferometry has been used to detect inhomogeneous heating in YBa 2 Cu 3 O 7−␦ coated conductors. The analysis was performed in a sample with a controlled defect, which causes a significant local reduction in the critical current value, I c . The experiments, which were performed with the sample surrounded by nitrogen vapor, have shown that the location of the initial hot spot leading to the complete transition to the normal state of the conductor ͑quench͒ is strongly dependent on the sample cooling configuration. When the sample is mainly cooled by gas convection, the quench always starts in the low-I c region, while for improved cooling configurations the initial hot spot does not always coincide with this region. The results have been compared with those obtained by direct electric field measurements along the sample in nitrogen vapor and liquid.
In this paper we introduce a field diagnostic device based on the combination of advanced bio-sensing and photonics technologies, to tackle emerging and endemic viruses causing swine epidemics, and consequently significant economic damage in farms. The device is based on the use of microring resonators fabricated in silicon nitride with CMOS compatible techniques. In the paper, the designed and fabricated photonic integrated circuit (PIC) sensors are presented and characterized, showing an optimized performance in terms of optical losses (30 dB per ring) and extinction ration for ring resonances (15 dB). Furthermore, the results of an experiment for porcine circovirus 2 (PCV2) detection by using the developed biosensors are presented. Positive detection for different virus concentrations has been obtained. The device is currently under development in the framework of the EU Commission co-funded project SWINOSTICS.
In this paper we present the development of photonic integrated circuit (PIC) biosensors for the label-free detection of six emerging and endemic swine viruses, namely: African Swine Fever Virus (ASFV), Classical Swine Fever Virus (CSFV), Porcine Reproductive and Respiratory Syndrome Virus (PPRSV), Porcine Parvovirus (PPV), Porcine Circovirus 2 (PCV2), and Swine Influenza Virus A (SIV). The optical biosensors are based on evanescent wave technology and, in particular, on Resonant Rings (RRs) fabricated in silicon nitride. The novel biosensors were packaged in an integrated sensing cartridge that included a microfluidic channel for buffer/sample delivery and an optical fiber array for the optical operation of the PICs. Antibodies were used as molecular recognition elements (MREs) and were selected based on western blotting and ELISA experiments to ensure the high sensitivity and specificity of the novel sensors. MREs were immobilized on RR surfaces to capture viral antigens. Antibody–antigen interactions were transduced via the RRs to a measurable resonant shift. Cell culture supernatants for all of the targeted viruses were used to validate the biosensors. Resonant shift responses were dose-dependent. The results were obtained within the framework of the SWINOSTICS project, contributing to cover the need of the novel diagnostic tools to tackle swine viral diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.