ORCID Profile
0000-0001-8996-2676
Current Organisations
Université McGill
,
Harbin Institute of Technology
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Publisher: OSA
Date: 2018
Publisher: OSA
Date: 2018
Publisher: Frontiers Media SA
Date: 24-06-2021
DOI: 10.3389/FENRG.2021.565761
Abstract: We propose a novel solar thermochemical receiver–reactor array concept for hydrogen production via ceria redox cycling. The receiver–reactor array can improve the solar-to-fuel efficiency by realizing the heat recuperation, reduction, and oxidation processes synchronously. A linear matrix model and a lumped parameter model are developed to predict thermal performance of the new solar thermochemical system. The system thermal performance is characterized by heat recovery effectiveness of solid-phase and solar-to-fuel efficiency. Investigated parameters include reduction temperature, oxygen partial pressure, number of receiver–reactors, concentration ratio, and gas-phase heat recovery effectiveness. For baseline conditions, the solid-phase heat recovery effectiveness and the solar-to-fuel efficiency are found to be 81% and 27%, respectively. For perfect gas-phase heat recovery and a solar concentration ratio of 5,000, the solar-to-fuel efficiency exceeds 40%.
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.BIORTECH.2022.127451
Abstract: The concentric-tube internal loop airlift reactor is a typical reactor configuration which has been adopted for a myriad of chemical and biological processes. The reactor hydrodynamics (including mixing) and the mass transfer between the gas and liquid phases remarkably affect the operational conditions and thus are crucial to the overall reactor performance. Hence, this study aims at providing a thorough description of the basic concepts and a comprehensive review of the relevant reported studies on the hydrodynamics and mass transfer of the concentric-tube internal loop airlift reactors, taking microalgae cultivation as an exemplary application. In particular, the reactor characteristics, geometry, CFD modeling, experimental characterization, and scale up considerations are elucidated. The research gaps for future research and development are also identified.
Publisher: Cold Spring Harbor Laboratory
Date: 13-09-2019
DOI: 10.1101/768846
Abstract: The nervous system is endowed with predictive capabilities, updating neural activity to reflect recent stimulus statistics in a manner which optimises processing of expected future states. This process has previously been formulated within a predictive coding framework, where sensory input is either “explained away” by accurate top-down predictions, or leads to a salient prediction error which triggers an update to the existing prediction when inaccurate. However, exactly how the brain optimises predictive processes in the stochastic and multi-faceted real-world environment remains unclear. Auditory evoked potentials have proven a useful measure of monitoring unsupervised learning of patterning in sound sequences through modulations of the mismatch negativity component which is associated with “change detection” and widely used as a proxy for indexing learnt regularities. Here we used dynamic causal modelling to analyse scalp-recorded auditory evoked potentials collected during presentation of sound sequences consisting of multiple, nested regularities and extend on previous observations of pattern learning restricted to the scalp level or based on single-outcome events. Patterns included the regular characteristics of the two tones presented, consistency in their relative probabilities as either common standard ( p = .875) or rare deviant ( p = .125), and the regular rate at which these tone probabilities alternated. Significant changes in connectivity reflecting a drop in the precision of prediction errors based on learnt patterns were observed at three points in the sound sequence, corresponding to the three hierarchical levels of nested regularities: (1) when an unexpected “deviant” sound was encountered (2) when the probabilities of the two tonal states altered and (3) when there was a change in rate at which probabilities in tonal state changed. These observations provide further evidence of simultaneous pattern learning over multiple timescales, reflected through changes in neural activity below the scalp. Our physical environment is comprised of regularities which give structure to our world. This consistency provides the basis for experiential learning, where we can increasingly master our interactions with our surroundings based on prior experience. This type of learning also guides how we sense and perceive the world. The sensory system is known to reduce responses to regular and predictable patterns of input, and conserve neural resources for processing input which is new and unexpected. Temporal pattern learning is particularly important for auditory processing, in disentangling overlapping sound streams and deciphering the information value of sound. For ex le, understanding human language requires an exquisite sensitivity to the rhythm and tempo of speech sounds. Here we elucidate the sensitivity of the auditory system to concurrent temporal patterning during a sound sequence consisting of nested patterns over three timescales. We used dynamic causal modelling to demonstrate that the auditory system monitors short, intermediate and longer-timescale patterns in sound simultaneously. We also show that these timescales are each represented by distinct connections between different brain areas. These findings support complex interactions between different areas of the brain as responsible for the ability to learn sophisticated patterns in sound even without conscious attention.
Publisher: Elsevier
Date: 2021
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 04-2022
Publisher: The Optical Society
Date: 19-05-2016
DOI: 10.1364/OE.24.00A985
Publisher: Springer Science and Business Media LLC
Date: 04-12-2018
DOI: 10.1038/S41598-018-35834-1
Abstract: Obese in iduals discount future rewards to a higher degree than lean in iduals, which is generally considered disadvantageous. Moreover, their decisions are altered more easily by decision-irrelevant cues. Here, we investigated neural correlates of this phenomenon using functional MRI. We tested 30 lean and 26 obese human subjects on a primed delay discounting paradigm using gustatory and visual cues of positive, neutral and negative valence to bias their intertemporal preferences. We hypothesised that activation differences in reward-related and behavioural control areas, and changes in connectivity between these areas, would reflect the effect of these cues. Here, obese subjects were more susceptible to priming with negative gustatory cues towards delayed choices as opposed to lean subjects. This was related to lower activity in the left dorsolateral prefrontal cortex during priming. Modulation of functional connectivity between the dlPFC and the ventromedial PFC by the behavioural priming effect correlated negatively with BMI. This might indicate that default goals of obese in iduals were different from those of lean participants, as the dlPFC has been suggested to be involved in internal goal pursuit. The present results further our understanding of the role of the PFC in decision-making and might inform future weight-management approaches based on non-invasive brain stimulation.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 06-2016
Publisher: Cold Spring Harbor Laboratory
Date: 07-06-2022
DOI: 10.1101/2022.06.07.22275937
Abstract: Obesity has a strong genetic component, with up to 20% of variance in body mass index (BMI) being accounted for by common polygenic variation. Most genetic polymorphisms associated with BMI are related to genes expressed in the central nervous system. At the same time, higher BMI is associated with neurocognitive changes. However, the direct link between genetics of obesity and neurobehavioral mechanisms related to weight gain is missing. Here, we use a large s le of participants (n ,000) from the Adolescent Brain Cognitive Development cohort and investigate how genetic risk for obesity, expressed as polygenic risk score for BMI (BMI-PRS), is related to brain and behavioral differences in adolescents. In a series of analyses, we show that BMI-PRS is related to lower cortical volume and thickness in the frontal and temporal areas, relative to age-expected values. Relatedly, using structural equation modeling, we find that lower overall cortical volume is associated with higher impulsivity, which in turn is related to an increase in BMI 1 year later. In sum, our study shows that obesity might partially stem from genetic risk as expressed in brain changes in the frontal and temporal brain areas, and changes in impulsivity.
Publisher: Optica Publishing Group
Date: 17-06-2020
DOI: 10.1364/OE.389924
Abstract: We propose a concept of a rotating tower reflector (TR) in a beam-down optical system to alternate concentrated solar irradiation of an array of solar receiver–reactors, realizing multi-step solar thermochemical redox cycles. Optical and radiative characteristics of the proposed system are explored analytically and numerically by Monte-Carlo ray-tracing simulations. We study the effects of the system geometrical and optical parameters on the optical and radiative performance. TR axis is required to be tilted for accommodating the receiver–reactor array, resulting in reduced optical efficiency. We demonstrate that the annual optical efficiency of a baseline system with the receiver–reactor located south of the tower decreases from 46% to 37% for the axis tilt angle of TR increasing from 2° to 20°. The optical analysis conducted in this study provides a general formulation to enable predictions of required gain of thermal-to-chemical efficiency of the receiver–reactor array for obtaining improved overall solar-to-chemical efficiency of the solar thermochemical plant.
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 07-2023
Publisher: ASME International
Date: 24-02-2020
DOI: 10.1115/1.4046229
Abstract: A transient heat transfer model is developed to study the thermal performance of a high-temperature solar thermochemical reactor for metal oxide reduction. The solar reactor consists of an indirectly irradiated tubular fluidized bed contained in a solar cavity receiver. Radiative heat transfer in the cavity, modeled with the Monte Carlo ray-tracing method, is coupled to conduction in the tube and cavity walls. Incident radiation distributions from a diffuse radiative source and a high-flux solar simulator are implemented separately in the model to study the influence of incident radiation directionality on the performance of the reactor. Maximum temperature, maximum thermal stress, start-up time, energy balance, and particle reduction rate for the proposed reactor concept are calculated to inform the design and optimization of a prototype reactor.
Publisher: Optica Publishing Group
Date: 12-2020
DOI: 10.1364/OE.404867
Abstract: A multi-aperture solar central receiver system is optically analyzed for increasing the net power to the receiver in a wide temperature range of 600–1800 K. A model system comprises a tower, a multi-aperture receiver with compound parabolic concentrators, and heliostat sub-fields. Optical modeling is performed using in-house developed Monte-Carlo ray-tracing programs. The heliostat sub-field geometrical configuration, the number of receiver apertures and optical properties of reflective surfaces are varied in the parametric study. Increasing the number of apertures from one to four increases the maximum net receiver power from 116 MW to 332 MW. The use of more than four apertures results in only limited further gain of the net receiver power but significantly decreases the overall optical efficiency and the solar-to-thermal efficiency. The optimal temperature for the maximized annual solar-to-exergy efficiency is found in the range of 1100–1200 K. This optimal temperature decreases slightly with an increasing number of apertures.
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 10-2019
Location: Germany
No related grants have been discovered for Filip Morys.