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- Lloyd-Spets, Anita, et al.
(författare)
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MISiCFET chemical gas sensors for high temperature and corrosive environment applications
- 2002
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 389-3, s. 1415-1418
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Tidskriftsartikel (refereegranskat)abstract
- A chemical gas sensor based on a silicon carbide field effect transistor with a catalytic gate metal has been under development for a number of years. The buried gate design allows the sensor to operate at high temperatures, routinely up to 600degreesC and for at least three days at 700degreesC. The chemical inertness of silicon carbide makes it a suitable sensor technology for applications in corrosive environments such as exhaust gases and flue gases from boilers. The selectivity of the sensor devices is established through the choice of type and structure of the gate metal as well as the operation temperature. In this way NH3 sensors with low cross sensitivity to NOx have been demonstrated as potential sensors for control of selective catalytic reduction (SCR) of NOx by urea injection into diesel exhausts. The hardness of the silicon carbide makes it for example more resistant to water splash at cold start of a petrol engine than existing technologies, and a sensor which can control the air to fuel ratio, before the exhaust gases are heated, has been demonstrated. Silicon carbide sensors are also tested in flue gases from boilers. Efficient regulation of the combustion in a boiler will decrease fuel consumption and reduce emissions.
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| 2. |
- Lloyd-Spets, Anita, et al.
(författare)
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SiC based field effect gas sensors for industrial applications
- 2001
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Ingår i: Physica status solidi. A, Applied research. - 0031-8965 .- 1521-396X. ; 185:1, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- The development and field-testing of high-temperature sensors based on silicon carbide devices have shown promising results in several application areas. Silicon carbide based field-effect sensors can be operated over a large temperature range, 100-600 degreesC, and since silicon carbide is a chemically very inert material these sensors can be used in environments like exhaust gases and flue gases from boilers. The sensors respond to reducing gases like hydrogen, hydrocarbons and carbon monoxide. The use of different temperatures, different catalytic metals and different structures of the gate metal gives selectivity to different gases and arrays of sensors can be used to identify and monitor several components in gas mixtures. MOSFET sensors based on SIC combine the advantage of simple circuitry with a thicker insulator, which increases the long term stability of the devices. In this paper we describe silicon carbide MOSFET sensors and their performance and give: examples of industrial applications such as monitoring of car exhausts and flue gases. Chemometric methods have been used for the evaluation of the data.
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| 5. |
- Baranzahi, Amir, et al.
(författare)
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Response of metal-oxide-silicon carbide sensors to simulated and real exhaust gases
- 1997
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 43:1-3, s. 52-59
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Tidskriftsartikel (refereegranskat)abstract
- Field effect devices based on catalytic metal-oxide-silicon carbide (MOSiC) structures can be used as high temperature gas sensors. The devices are sensitive to hydrocarbons and hydrogen and can be operated up to at least 900 degrees C, which make them suitable for several combustion applications, Simulated and real exhaust gases from a car engine have been studied at sensor temperatures from 200 to 650 degrees C, and it was round that the sensor signal is high for excess hydrocarbon and low for excess oxygen. The response time is less than 100 ms and only a small degradation of the devices was observed after several days of operation. The devices also react to changes of the gas composition In the fuel-rich and fuel-lean region. The devices show an interesting temperature dependence in the fuel rich region.
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| 6. |
- Kaiser, M., et al.
(författare)
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VEDLIoT: Very Efficient Deep Learning in IoT
- 2022
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Ingår i: Proceedings of the 2022 Design, Automation and Test in Europe Conference and Exhibition, DATE 2022. - : IEEE. - 9783981926361
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Konferensbidrag (refereegranskat)abstract
- The VEDLIoT project targets the development of energy-efficient Deep Learning for distributed AIoT applications. A holistic approach is used to optimize algorithms while also dealing with safety and security challenges. The approach is based on a modular and scalable cognitive IoT hardware platform. Using modular microserver technology enables the user to configure the hardware to satisfy a wide range of applications. VEDLIoT offers a complete design flow for Next-Generation IoT devices required for collaboratively solving complex Deep Learning applications across distributed systems. The methods are tested on various use-cases ranging from Smart Home to Automotive and Industrial IoT appliances. VEDLIoT is an H2020 EU project which started in November 2020. It is currently in an intermediate stage with the first results available.
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| 7. |
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| 8. |
- Sagalowicz, Laurent, et al.
(författare)
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Structure of the wafer fused InP (001)-GaAs (001) interface
- 1997
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Ingår i: Philosophical Magazine Letters. - : Informa UK Limited. - 0950-0839 .- 1362-3036. ; 76:6, s. 445-452
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Tidskriftsartikel (refereegranskat)abstract
- A structural study of wafer fused InP-GaAs interfaces has been carried out. The geometry of the dislocation network which accommodates the twist and the lattice mismatch is first given using a geometrical approach. Cross-sectional transmission electron microscopy and plan view observations are presented. Two different misfit cases are observed. (1) When no twist is present, the 3.7% lattice mismatch is relaxed by a regular square network of dislocations with pure edge character. (2) When an additional twist is present, a square network of dislocations results as well but here the dislocations have a mixed character; 60° dislocations are also observed, some form closed defect circuits and others very likely accommodate a small tilt. The interaction between the 60° dislocations and the edge dislocations is explained in detail. Voids or inclusions are also observed as well as additional dislocations which may accommodate part of the thermal mismatch. © 1997 Taylor & Francis Ltd.
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| 9. |
- Salami, B., et al.
(författare)
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LEGaTO: Low-Energy, Secure, and Resilient Toolset for Heterogeneous Computing
- 2020
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Ingår i: PROCEEDINGS OF THE 2020 DESIGN, AUTOMATION & TEST IN EUROPE CONFERENCE & EXHIBITION (DATE 2020). - 1530-1591. - 9783981926347 ; , s. 169-174
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Konferensbidrag (refereegranskat)abstract
- The LEGaTO project leverages task-based programming models to provide a software ecosystem for Made in-Europe heterogeneous hardware composed of CPUs, GPUs, FPGAs and dataflow engines. The aim is to attain one order of magnitude energy savings from the edge to the converged cloud/HPC, balanced with the security and resilience challenges. LEGaTO is an ongoing three-year EU H2020 project started in December 2017.
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| 10. |
- Salomonsson, T., et al.
(författare)
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Abnormal cerebral hemodynamics and blood-brain barrier permeability detected with perfusion MRI in systemic lupus erythematosus patients
- 2023
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Ingår i: NeuroImage: Clinical. - : Elsevier BV. - 2213-1582. ; 38
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) has previously shown alterations in cerebral perfusion in patients with systemic lupus erythematosus (SLE). However, the results have been inconsistent, in particular regarding neuropsychiatric (NP) SLE. Thus, we investigated perfusion-based measures in different brain regions in SLE patients with and without NP involvement, and additionally, in white matter hyperintensities (WMHs), the most common MRI pathology in SLE patients. Materials and methods: We included 3 T MRI images (conventional and DSC) from 64 female SLE patients and 19 healthy controls (HC). Three different NPSLE attribution models were used: the Systemic Lupus International Collaborating Clinics (SLICC) A model (13 patients), the SLICC B model (19 patients), and the American College of Rheumatology (ACR) case definitions for NPSLE (38 patients). Normalized cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were calculated in 26 manually drawn regions of interest and compared between SLE patients and HC, and between NPSLE and non-NPSLE patients. Additionally, normalized CBF, CBV and MTT, as well as absolute values of the blood-brain barrier leakage parameter (K2) were investigated in WMHs compared to normal appearing white matter (NAWM) in the SLE patients. Results: After correction for multiple comparisons, the most prevalent finding was a bilateral significant decrease in MTT in SLE patients compared to HC in the hypothalamus, putamen, right posterior thalamus and right anterior insula. Significant decreases in SLE compared to HC were also found for CBF in the pons, and for CBV in the bilateral putamen and posterior thalamus. Significant increases were found for CBF in the posterior corpus callosum and for CBV in the anterior corpus callosum. Similar patterns were found for both NPSLE and non-NPSLE patients for all attributional models compared to HC. However, no significant perfusion differences were revealed between NPSLE and non-NPSLE patients regardless of attribution model. The WMHs in SLE patients showed a significant increase in all perfusion-based metrics (CBF, CBV, MTT and K2) compared to NAWM. Conclusion: Our study revealed perfusion differences in several brain regions in SLE patients compared to HC, independently of NP involvement. Furthermore, increased K2 in WMHs compared to NAWM may indicate blood-brain barrier dysfunction in SLE patients. We conclude that our results show a robust cerebral perfusion, independent from the different NP attribution models, and provide insight into potential BBB dysfunction and altered vascular properties of WMHs in female SLE patients. Despite SLE being most prevalent in females, a generalization of our conclusions should be avoided, and future studies including all sexes are needed.
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