| 1. |
- Ehn, Sebastian, et al.
(författare)
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X-ray deconvolution microscopy
- 2016
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Ingår i: Biomedical Optics Express. - 2156-7085. ; 7:4, s. 1227-1239
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in single-photon-counting detectors are enabling the development of novel approaches to reach micrometer-scale resolution in x-ray imaging. One example of such a technology are the MEDIPIX3RX-based detectors, such as the LAMBDA which can be operated with a small pixel size in combination with real-time on-chip charge-sharing correction. This characteristic results in a close to ideal, box-like point spread function which we made use of in this study. The proposed method is based on raster-scanning the sample with sub-pixel sized steps in front of the detector. Subsequently, a deconvolution algorithm is employed to compensate for blurring introduced by the overlap of pixels with a well defined point spread function during the raster-scanning. The presented approach utilizes standard laboratory x-ray equipment while we report resolutions close to 10 mu m. The achieved resolution is shown to follow the relationship p/n with the pixel-size p of the detector and the number of raster-scanning steps n. (C) 2016 Optical Society of America
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| 2. |
- Wang, Ke, et al.
(författare)
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100 Gb/s RZ-OOK transmission through 212 km deployed SSMF using monolithically integrated ETDM receiver module
- 2011
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 284:3, s. 782-786
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Tidskriftsartikel (refereegranskat)abstract
- 100 Gb/s on-off keying (OOK) transmission over 212 km installed standard single-mode fibers using an Indium Phosphide (InP)-based electrical clock-data-recovery (CDR) and demultiplexer module was demonstrated 5 5 x 10(-11) bit error rate (BER) performance was achieved and 11 dB optical signal-to-noise ratio (OSNR) penalty was required at 10(-9) BER after transmission
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| 3. |
- Andersson, Tommy, et al.
(författare)
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Multiobjective Optimization of a Heat-Sink Design Using the Sandwiching Algorithm and an Immersed Boundary Conjugate Heat Transfer Solver
- 2018
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Ingår i: Journal of Heat Transfer. - : ASME International. - 1528-8943 .- 0022-1481. ; 140:10, s. 102002 -
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Tidskriftsartikel (refereegranskat)abstract
- The thermal management is an ever increasing challenge in advanced electronic devices. In this paper, simulation-based optimization is applied to improve the design of a plate-fin heat-sink in terms of operational cost and thermal performance. The proposed framework combines a conjugate heat transfer solver, a CAD engine and an adapted Sandwiching algorithm. A key feature is the use of novel immersed boundary (IB) techniques that allows for automated meshing which is perfectly suited for parametric design optimization.
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| 4. |
- Arman, Alif, et al.
(författare)
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Adsorption of hydrogen on stable and metastable Ir(100) surfaces
- 2017
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Ingår i: Surface Science. - : Elsevier BV. - 0039-6028. ; 656, s. 66-76
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Using the combination of high resolution core level spectroscopy and density functional theory we present adetailed spectroscopic study for all clean and hydrogen covered phases of Ir(100). The results are complementedby an investigation of the hydrogen desorption process from various phases using temperature programmeddesorption spectroscopy and scanning tunneling microscopy. In total, all experimentally determined core levelshifts match very well with those predicted by density functional theory based on established structural models.In particular, we find for the (bridge site) adsorption on the unreconstructed 1×1 phase that the initial core levelshift of surface Ir atoms is altered by +0.17 eV for each Ir–H bond formed. In the submonolayer regime we findevidence for island formation at low temperatures. For the H-induced deconstructed 5×1-H phase we identifyfour different surface core level shifts with two of them being degenerate. Finally, for the reconstructed 5×1-hexphase also four surface components are identified, which undergo a rather rigid core level shift of +0.15 eV uponhydrogen adsorption suggesting a similarly homogeneous charge transfer to all Ir surface atoms.Thermodesorption experiments for the 5×1-H phase reveal two different binding states for hydrogenindependent of the total coverage. We conclude that the surface always separates into patches of fully covereddeconstructed and uncovered reconstructed phases. We could also show by tunneling microscopy that with thedesorption of the last hydrogen atom from the deconstructed unit cell the surface instantaneously reverts intothe reconstructed state. Eventually, we could determine the saturation coverage upon molecular adsorption forall phases to be θmax = 1.0 ML1×1−H , θ = 0.8 ML max5×1−H , and θ ≥ 1.0 ML max5×1−hex−H .
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| 5. |
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| 6. |
- Blanco, A., et al.
(författare)
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Performance of timing resistive plate chambers with relativistic neutrons from 300 to 1500 MeV
- 2015
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Ingår i: Journal of Instrumentation. - : IOP Publishing. - 1748-0221. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- A prototype composed of four resistive plate chamber layers has been exposed to quasi-monoenergetic neutrons produced from a deuteron beam of varying energy (300 to 1500 AMeV) in experiment S406 at GSI, Darmstad, Germany. Each layer, with an active area of about 2000 × 500 mm2, is made of modules containing the active gaps, all in multigap construction. Each gap is defined by 0.3 mm nylon mono-filaments positioned between 2.85 mm thick float glass electrodes. The modules are operated in avalanche mode with a non-flammable gas mixture composed of 90% C2H2F4 and 10% SF6. The signals are readout by a pick-up electrode formed by 15 copper strips (per layer), spaced at a pitch of 30 mm, connected at both sides to timing front end electronics. Measurements of the time of flight jitter of neutrons, in the mentioned energy range, point to a contribution of the resistive plate chamber in the order of 150 ps, independent of the neutron energy.
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| 7. |
- Boretzky, K., et al.
(författare)
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NeuLAND: The high-resolution neutron time-of-flight spectrometer for R 3 B at FAIR
- 2021
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1014
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Tidskriftsartikel (refereegranskat)abstract
- NeuLAND (New Large-Area Neutron Detector) is the next-generation neutron detector for the R3B (Reactions with Relativistic Radioactive Beams) experiment at FAIR (Facility for Antiproton and Ion Research). NeuLAND detects neutrons with energies from 100 to 1000 MeV, featuring a high detection efficiency, a high spatial and time resolution, and a large multi-neutron reconstruction efficiency. This is achieved by a highly granular design of organic scintillators: 3000 individual submodules with a size of 5 × 5 × 250 cm3 are arranged in 30 double planes with 100 submodules each, providing an active area of 250 × 250 cm2 and a total depth of 3 m. The spatial resolution due to the granularity together with a time resolution of σt≤ 150 ps ensures high-resolution capabilities. In conjunction with calorimetric properties, a multi-neutron reconstruction efficiency of 50% to 70% for four-neutron events will be achieved, depending on both the emission scenario and the boundary conditions allowed for the reconstruction method. We present in this paper the final design of the detector as well as results from test measurements and simulations on which this design is based.
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| 8. |
- Borg, Mattias, et al.
(författare)
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Facet-selective group-III incorporation in InGaAs template assisted selective epitaxy
- 2019
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 30:8
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Tidskriftsartikel (refereegranskat)abstract
- InGaAs is a potential candidate for Si replacement in upcoming advanced technological nodes because of its excellent electron transport properties and relatively low interface defect density in dielectric gate stacks. Therefore, integrating InGaAs devices with the established Si platforms is highly important. Using template-assisted selective epitaxy (TASE), InGaAs nanowires can be monolithically integrated with high crystal quality, although the mechanisms of group III incorporation in this ternary material have not been thoroughly investigated. Here we present a detailed study of the compositional variations of InGaAs nanostructures epitaxially grown on Si(111) and Silicon-on-insulator substrates by TASE. We present a combination of XRD data and detailed EELS maps and find that the final Ga/In chemical composition depends strongly on both growth parameters and the growth facet type, leading to complex compositional sub-structures throughout the crystals. We can further conclude that the composition is governed by the facet-dependent chemical reaction rates at low temperature and low V/III ratio, while at higher temperature and V/III ratio, the incorporation is transport limited. In this case we see indications that the transport is a competition between Knudsen flow and surface diffusion.
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| 9. |
- Chèze, David, et al.
(författare)
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Final report on Control strategies, fault detection and on-line diagnosis in WP6 - Deliverable 6.4 : MacSheep -New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance
- 2015
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Rapport (populärvet., debatt m.m.)abstract
- The main objective of this work package was to investigate generic control strategies, generic fault-detection and on-line diagnosis algorithms that may apply to the developed prototypes of solar and heatpump systems within MacSheep. The results should lead toimproved reliability and/orincreased energy savings for the end-userthrough new controller features. The use of DHW consumption forecast was identified as a promising control strategy and a simple yet reasonably effective algorithm to get the water tapping behaviourof the userwas developed. Viessmannimplemented the ideas of this approach in an ICT solution for their controller to provide statistical tapping informationto the user who can then set the period when hot waterthatis expected to be used. The operationalstrategy based on DHW consumptionforecast for one hour was not implemented since the potential gains are small (~2%) and there is ahigh user discomfort risk in the case of an inaccurate forecastPrevious studies have shown that solar overheating of the building led to gas savings with solar gas combisystems. Using a similar strategy on the MacSheep reference system did not lead to significant savings, due to strong interactions between space and DHW heating and a higher share of HP operation time for DHW charging of the store, which has a lower efficiency.Another smart control strategy was investigated forvariable electricity pricesusing overheating of the building and/or the DHW volume of the store.The main conclusion of the study is that the combination of the two algorithms led to cost savings for the Austria (Graz) and France (Chambery) with both theSFH45 and SFH100 buildings.Since only the share related to user consumption varies during the day while the grid and transmission costs are usually constant, thecost savings were small, far below 1%.Among the proposed fault detection algorithms for solar and heat pump systems, detection of wrongly connected tubes in the solar collector loop was found interesting by Viesmmann and Regulus. It was implemented and tested in their respective prototype controller. Regulus also implemented the detection of wrong order phase connections in its heat pump prototype as well as threshold tests on abnormal temperature and pressure evolution.
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| 10. |
- Haller, Michel, et al.
(författare)
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System simulations
- 2015. - 1
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Ingår i: Solar and Heat Pump Systems for Residential Buildings. - : John Wiley & Sons. - 9783433030400 ; , s. 274-
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Bokkapitel (refereegranskat)
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