| 1. |
- Marconi, A., et al.
(författare)
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ANDES, the high resolution spectrograph for the ELT : science case, baseline design and path to construction
- 2022
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Ingår i: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY IX. - : SPIE - International Society for Optical Engineering. - 9781510653504 - 9781510653498
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Konferensbidrag (refereegranskat)abstract
- The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs (UBV, RIZ, YJH) providing a spectral resolution of similar to 100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 mu m with the goal of extending it to 0.35-2.4 mu m with the addition of a K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre-feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Its modularity will ensure that ANDES can be placed entirely on the ELT Nasmyth platform, if enough mass and volume is available, or partly in the Coude room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature's fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of more than 200 scientists and engineers which represent the majority of the scientific and technical expertise in the field among ESO member states.
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| 2. |
- Cirasuolo, M., et al.
(författare)
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MOONS: the Multi-Object Optical and Near-infrared Spectrograph for the VLT
- 2014
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Ingår i: Ground-based and Airborne Instrumentation for Astronomy V. - : SPIE. - 0277-786X .- 1996-756X. ; 9147, s. 91470-91470
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Konferensbidrag (refereegranskat)abstract
- MOONS (the Multi-Object Optical and Near-infrared Spectrograph) has been selected by ESO as a third-generation instrument for the Very Large Telescope (VLT). The light grasp of the large collecting area offered by the VLT (8.2m diameter), combined with the large multiplex and wavelength coverage (optical to near-IR: 0.8 -1.8 mu m) of MOONS will provide the European astronomical community with a powerful, unique instrument able to pioneer a wide range of Galactic, extragalactic and cosmological studies, and it will provide crucial follow-up for major facilities such as Gaia, VISTA, Euclid and LSST. MOONS has the observational power needed to unveil galaxy formation and evolution over the entire history of the Universe, from stars in our Milky Way, through the redshift desert, and up to the epoch of very first galaxies and reionization of the Universe at redshifts of z > 8-9, just a few million years after the Big Bang. From five years of observations MOONS will provide high-quality spectra for > 3M stars in our Galaxy and the Local Group, and for 1-2M galaxies at z > 1 (for an SDSS-like survey), promising to revolutionize our understanding of the Universe. The baseline design consists of similar to 1000 fibres, deployable over a field-of-view of similar to 500 arcmin(2), the largest patrol field offered by the Nasmyth focus at the VLT. The total wavelength coverage is 0.8 -1.8 mu m with two spectral resolving powers: in the medium-resolution mode (R similar to 4,000-6,000) the entire wavelength range is observed simultaneously, while the high-resolution mode will cover three selected sub-regions simultaneously: one region with R similar to 8,000 near the Ca II triplet to measure stellar radial velocities, and two regions at R similar to 20,000 (one in each of the J- and H-bands), for precision measurements of chemical abundances.
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| 3. |
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| 4. |
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| 5. |
- Perot, B., et al.
(författare)
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The EURITRACK project : Development of a tagged neutron inspection system for cargo containers
- 2006
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Ingår i: Proc SPIE Int Soc Opt Eng. - : SPIE. - 0819462691 - 9780819462695
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Konferensbidrag (refereegranskat)abstract
- The EURopean Illicit TRAfficing Countermeasures Kit project is part of the 6th European Union Framework Program, and aims at developing a neutron inspection system for detecting threat materials (explosives, drugs, etc.) in cargo containers. Neutron interaction in the container produces specific gamma-rays used to determine the chemical composition of the inspected material. An associated particle sealed tube neutron generator is developed to allow precise location of the interaction point by direction and time-of-flight measurements of the neutrons tagged by alpha-particles. The EURITRACK project consists in developing: a transportable deuterium-tritium neutron generator including a position sensitive alpha detector (8×8 matrix of YAP:Ce crystals coupled to a multi-anode photomultiplier), fast neutron and gamma-ray detectors, front-end electronics to perform coincidence and spectroscopic measurements, and an integrated software which manages neutron generator and detectors positioning, data acquisition and analysis. Hardware components have been developed and tested by the consortium partners. Current status of this work and provisional performances of the system assessed by Monte Carlo calculations are presented.
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| 6. |
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| 7. |
- Araujo, L. F., et al.
(författare)
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In-fiber optofluidic alignment of Au-nanorods
- 2017
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. ; , s. 132-133
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Konferensbidrag (refereegranskat)abstract
- Optofluidic all-fiber devices are used for orientation of Au-nanorods under strongelectric fields. The dynamics is studied on sub-microsecond time-scales. A two-level laser rateequation model allows inferring diffusion rate, rotational mobility and other parameters.
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| 8. |
- Arun Chaudhari, Ojas, et al.
(författare)
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Effect of Phase Transition Temperatures of the Phase Change Material on Hydration and Mechanical Properties of Cement Paste
- 2021
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Ingår i: Proc of INTERNATIONAL CONFERENCE ON“CEMENT - BASED MATERIALS TAILORED FOR A SUSTAINABLE FUTURE. ; , s. 85-93
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Konferensbidrag (refereegranskat)abstract
- In recent years, the use of Phase Change Materials (PCMs) in cementitious materials have become of vital importance due to their ability to absorb and release the heat and promote thermal comfort in building applications, which is a requirement for saving energy and sustainable infrastructure. The presented study aimed at investigating the PCMs of different phase transition temperatures in cementitious system and their influence on hydration and mechanical properties of the system. In this study, three PCMs with different phase transition temperatures (24 °C, 29 °C and 58 °C) were incorporated into cement paste at various dosages. The mechanical and rheological properties of the cement pastes were evaluated using compressive strength, density, and slump flow measurement methods. In addition, isothermal calorimetry and semi-adiabatic calorimetry measurements were used to elucidate hydration attributes of the cement paste. The results reveal that both the phase transition temperature of PCM and its amount have a crucial effect on the properties of the cement-based material. Especially, the high phase transition temperature (58 °C) PCM has enhanced the heat of hydration and stabilized the temperature during the cement hydration, that resulted in higher compressive strength of the cementitious system. Whereas ambient phase transition temperature (24 °C and 29 °C) PCMs have negatively influenced the rate of strength development of the cementitious system. The slow rate of strength development was found to be attributed to reduction in heat of hydration, which was confirmed through the calorimetry studies.
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| 10. |
- Miccoli, L., et al.
(författare)
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In-plane shear behaviour of earthen materials panels strengthened with polyester fabric strips
- 2016
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Ingår i: Structural Analysis of Historical Constructions. - : CRC Press/Balkema. - 9781138029514 ; , s. 1099-1105
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Konferensbidrag (refereegranskat)abstract
- An experimental investigation was carried out to study the in-plane shear behaviour of earthen material panels strengthened with polyester fabric strips. Strengthened panels were developed to exploit the strength potential of earthen materials and to solve its lack of tensile strength, significantly improving not only strength but also ductility. Three earthen materials were considered: cob, earth block masonry (EBM) and rammed earth (RE). As first approach the strengthening configuration, based on different adhesive materials, was tested only for cob panels. As part of the study the results of a big testing campaign of unstrengthened panels were considered. Seven strengthened panels were tested in diagonal compression/shear.A unique reinforcement orientation was used. The results of these tests are presented in this paper, and include the load-displacement behaviours, crack patterns, failure modes. The results showed that the reinforcement was the most effective in EBM panels, with increase in strength and ductility observed. In RE and cob panels the reinforcement did not likely contribute significantly to the shear resistance, due to a lack of embedment length of the strips. Instead, in EBM it was likely that the vertical reinforcement acted in tension to restrain shear induced dilation and to restrain sliding.
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