| 1. |
- Guidi, H., et al.
(author)
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Autonomous maintenance of advanced process control : Application to an industrial depropanizer
- 2014
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In: Fuels and Petrochemicals Division 2014 - Core Programming Area at the 2014 AIChE Spring Meeting and 10th Global Congress on Process Safety. - : AIChE. - 9781634390736 ; , s. 923-932
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Conference paper (peer-reviewed)abstract
- Although Model Predictive Control (MPC) has been widely accepted as a main technology for Advanced Process Control (APC) due to its ability of operating the system closely to the constraints, proper maintenance of MPC systems is still a challenge. Based on this observation, this research aims to develop an automated support strategy for the autonomous maintenance of MPC. In this work, re-tuning and re-identification components of the automated support strategy are considered as corrective action to retain the performance of the system after a change in the plant dynamics causes performance degradation. An industrial FT-depropanizer is used to test the implementation of these components. Results successfully show that an automated unified framework approach to MPC maintenance can successfully be used in further securing the economic leverage of MPC in industry.
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| 2. |
- Lidington, Darcy, et al.
(author)
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CFTR Therapeutics Normalize Cerebral Perfusion Deficits in Mouse Models of Heart Failure and Subarachnoid Hemorrhage
- 2019
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In: JACC: Basic to Translational Science. - : Elsevier BV. - 2452-302X. ; 4:8, s. 940-958
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Journal article (peer-reviewed)abstract
- Heart failure (HF) and subarachnoid hemorrhage (SAH) chronically reduce cerebral perfusion, which negatively affects clinical outcome. This work demonstrates a strong relationship between cerebral artery cystic fibrosis transmembrane conductance regulator (CFTR) expression and altered cerebrovascular reactivity in HF and SAH. In HF and SAH, CFTR corrector compounds (C18 or lumacaftor) normalize pathological alterations in cerebral artery CFTR expression, vascular reactivity, and cerebral perfusion, without affecting systemic hemodynamic parameters. This normalization correlates with reduced neuronal injury. Therefore, CFTR therapeutics have emerged as valuable clinical tools to manage cerebrovascular dysfunction, impaired cerebral perfusion, and neuronal injury.
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| 3. |
- MacDonald, Patrick, et al.
(author)
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Impaired glucose-stimulated insulin secretion, enhanced IP insulin tolerance and increased {beta}-cell mass in mice lacking the p110{gamma} isoform of PI3-kinase.
- 2004
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In: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 145:9, s. 4078-4083
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Journal article (peer-reviewed)abstract
- Phosphoinositide 3-kinase (PI3 kinase) has been implicated in G protein-coupled receptor regulation of pancreatic ß-cell growth and glucose-stimulated insulin secretion. The G protein-activated p110{gamma} isoform of PI3 kinase was detected in insulinoma cells, mouse islets, and human islets. In 7- to 10-wk-old mice, knockout of p110{gamma} reduced the plasma insulin response to ip glucose injection and impaired first and second phase glucose-stimulated insulin secretion from pancreata perfused ex vivo. The p110{gamma} –/– mice responded to preinjection with the glucagon-like peptide-1 receptor agonist exendin 4, such that plasma glucose and insulin responses to ip glucose injection were not different from wild types. Mice lacking p110{gamma} were not diabetic and were only slightly glucose intolerant (ip glucose injection) compared with wild types, in part due to enhanced responsiveness to insulin as determined by an ip insulin tolerance test. Despite severely reduced insulin secretion in these animals, the p110{gamma} –/– mice had greater pancreatic insulin content, and an increased ß-cell mass due to ß-cell hypertrophy. These surprising results suggest that the G protein-coupled p110{gamma} isoform of PI3 kinase is not central to the development or maintenance of sufficient ß-cell mass but positively regulates glucose-stimulated insulin secretion.
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| 4. |
- Struyf, Eric, et al.
(author)
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Vegetation and proximity to the river control amorphous silica storage in a riparian wetland (Biebrza National Park, Poland)
- 2009
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In: Biogeosciences. - 1726-4189. ; 6:4, s. 623-631
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Journal article (peer-reviewed)abstract
- Wetlands can modify and control nutrient fluxes between terrestrial and aquatic ecosystems, yet little is known of their potential as biological buffers and sinks in the biogeochemical silica cycle. We investigated the storage of amorphous silica (ASi) in a central-European riparian wetland. The variation in storage of ASi in the soil of an undisturbed wetland was significantly controlled by two factors: dominance of sedges and grasses and distance to the river (combined R-2=78%). Highest ASi storage was found near the river and in sites with a dominance of grasses and sedges, plants which are well known to accumulate ASi. The management practice of mowing reduced the amount of variation attributed to both factors (R-2=51%). Although ASi concentrations in soils were low (between 0.1 and 1% of soil dry weight), ASi controlled the availability of dissolved silica (DSi) in the porewater, and thus potentially the exchange of DSi with the nearby river system through both diffusive and advective fluxes. A depth gradient in ASi concentrations, with lower ASi in the deeper layers, indicates dissolution. Our results show that storage and recycling of ASi in wetland ecosystems can differ significantly on small spatial scales. Human management interferes with the natural control mechanisms. Our study demonstrates that wetlands have the potential to modify the fluxes of both DSi and ASi along the land-ocean continuum and supports the hypothesis that wetlands are important ecosystems in the biogeochemical cycling of silica.
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| 5. |
- Özkan, Leyla, et al.
(author)
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Advanced autonomous model-based operation of industrial process systems (Autoprofit) : Technological developments and future perspectives
- 2016
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In: ANNUAL REVIEWS IN CONTROL. - : Elsevier. - 1367-5788. ; 42, s. 126-142
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Research review (peer-reviewed)abstract
- Model-based operation support technology such as Model Predictive Control (MPC) is a proven and accepted technology for multivariable and constrained large scale control problems in process industry. Despite the growing number of successful implementations, the low level of operational efficiency of MPC is an existing problem, specifically the lack of advanced maintenance technology. To this end, within the EU FP 7 program, a project (Autoprofit (1)) has been executed to advance the level of autonomy and automated maintenance of MPC technology. Taking linear model-based technology as a starting point, in the project a philosophy has been developed for autonomous performance monitoring, diagnosis, experiment design, model adaptation and controller re-tuning, that is driven by economic criteria in each step, working towards an operation support system in which effective maintenance and adaptation of MPC controllers becomes feasible. In this development, challenging research questions have been addressed in the areas of on-line performance monitoring and diagnosis, least costly experiment design, automated adaptation of models, and auto-tuning, and new fundamental techniques have been developed. Although a full fledge and industrially proven (semi-)automated system is not yet realised, parts of the on-line system have been implemented and validated on real life cases provided by the industrial partners, showing that the formulated objectives are within reach.
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