| 1. |
- Bouchouireb, Hamza, 1991-, et al.
(author)
-
The inclusion of End-Of-Life modelling in the Life Cycle Energy Optimisation methodology
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Other publication (other academic/artistic)abstract
- In this work, an End-Of-Life (EOL) model is included in the Life Cycle Energy Optimisation (LCEO) methodology to account for the energy burdens and credits stemming from a vehicle’s EOL processing phase and balance them against the vehicle’s functional requirements and production and use phase energies. The substitution with a correction factor allocation method is used to model the contribution of recycling to the EOL phase’s energy. The methodology is illustrated through the optimisation of the design of a simplified vehicle sub-system. For the latter, multiple recycling scenarios with varying levels of assumed recycling induced material property degradation were built, and their impact on the vehicle sub-system’s optimal solutions was compared to that of scenarios based on landfilling and incineration with energy recovery. The results show that the inclusion of EOL modelling in the LCEO methodology can significantly alter material use patterns thereby effecting the life cycle energy of the optimal designs. Indeed, the vehicle sub-system’s optimal designs associated with the recycling scenarios are on average substantially heavier, and less life cycle energy demanding, than their landfilling or incineration with energy recovery-related counterparts.
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| 2. |
- Bouchouireb, Hamza, et al.
(author)
-
The inclusion of end-of-life modelling in the life cycle energy optimisation methodology
- 2021
-
In: Journal of Mechanical Design. - : ASME International. - 1050-0472 .- 1528-9001. ; 143:5
-
Journal article (peer-reviewed)abstract
- In this work, an End-Of-Life (EOL) model is included in the Life Cycle Energy Optimisation (LCEO) methodology to account for the energy burdens and credits stemming from a vehicle's EOL processing phase and balance them against the vehicle's functional requirements and production and use phase energies. The substitution with a correction factor allocation method is used to model the contribution of recycling to the EOL phase's energy. The methodology is illustrated through the optimisation of the design of a simplified vehicle sub-system. For the latter, multiple recycling scenarios with varying levels of assumed recycling induced material property degradation were built, and their impact on the vehicle sub-system's optimal solutions was compared to that of scenarios based on landfilling and incineration with energy recovery. The results show that the vehicle sub-system's optimal designs are significantly dependent on the EOL scenario considered. In particular, the optimal designs associated with the recycling scenarios are on average substantially heavier, and less life cycle energy demanding, than their landfilling or incineration with energy recovery-related counterparts; thus, demonstrating how the inclusion of EOL modelling in the LCEO methodology can significantly alter material use patterns, thereby effecting the very mechanisms enabling the embodiment of the resulting life cycle energy optimal designs.
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| 3. |
- Bouchouireb, Hamza, et al.
(author)
-
The inclusion of vehicle shape and aerodynamic drag estimations within the life cycle energy optimisation methodology
- 2019
-
In: Procedia CIRP. - : Elsevier. - 2212-8271 .- 2212-8271. ; 84, s. 902-907
-
Journal article (peer-reviewed)abstract
- The present work describes a widening of the scope of the Life Cycle Energy Optimisation (LCEO) methodology with the addition of shape-related design variables. They describe the curvature of a vehicle which impacts its aerodynamic drag and therewith its operational energy demand. Aerodynamic drag is taken into account through the estimation of the drag coefficient of the vehicle body shape using computational fluid dynamics simulations. Subsequently, the aforementioned coefficient is used to calculate the operational energy demand associated with the vehicle. The methodology is applied to the design of the roof of a simplified 2D vehicle model which is both mechanically and geometrically constrained. The roof is modelled as a sandwich structure with its design variables consisting of the material compositions of the different layers, their thicknesses as well as the shape variables. The efficacy of the LCEO methodology is displayed through its ability to deal with the arising functional conflicts while simultaneously leveraging the design benefits of the underlying functional alignments. On average, the optimisation process resulted in 2.5 times lighter and 4.5 times less life cycle energy-intensive free shape designs. This redesign process has also underlined the necessity of defining an allocation strategy for the energy necessary to overcome drag within the context of vehicle sub-system redesign.
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| 4. |
- Bouchouireb, Hamza, 1991-, et al.
(author)
-
Towards holistic energy-efficient vehicle product system design: The case for a penalized continuous end-of-life model in the life cycle energy optimisation methodology
- 2019
-
In: Proceedings of the International Conference on Engineering Design. - : Cambridge University Press. - 2220-4334 .- 2220-4342. ; 1, s. 2901-2910
-
Journal article (peer-reviewed)abstract
- The Life Cycle Energy Optimisation (LCEO) methodology aims at finding a design solution that uses a minimum amount of cumulative energy demand over the different phases of the vehicle's life cycle, while complying with a set of functional constraints. This effectively balances trade-offs, and therewith avoids sub-optimal shifting between the energy demand for the cradle-to-production of materials, operation of the vehicle, and end-of-life phases. The present work describes the extension of the LCEO methodology to perform holistic product system optimisation. The constrained design of an automotive component and the design of a subset of the processes which are applied to it during its life cycle are simultaneously optimised to achieve a minimal product system life cycle energy. A subset of the processes of the end-of-life phase of a vehicle’s roof are modelled through a continuous formulation. The roof is modelled as a sandwich structure with its design variables being the material compositions and the thicknesses of the different layers. The results show the applicability of the LCEO methodology to product system design and the use of penalisation to ensure solution feasibility.
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| 5. |
- Bouchouireb, Hamza, 1991-, et al.
(author)
-
Vehicle aerodynamic shape significantly impacted by vehicle material composition and material circularity potential in life cycle energy optimal vehicle design
-
Other publication (other academic/artistic)abstract
- This paper explores how the systemic-level energy consumption of light-duty vehicles could be reduced through integrative design. To this end, the Life Cycle Energy Optimisation (LCEO) methodology is used to achieve the coupled optimal use of materials (including their circularity potential) and vehicle aerodynamic shape to reduce the overall Life Cycle Energy (LCE) footprint of light-duty vehicles, with the results being compared to the lightweight and aerodynamic alternatives. Initially, the methodology is functionally expanded to handle aerodynamic functional requirements through the definition of a novel allocation strategy for the aerodynamic energy, and a parametrised simple vehicle body model that ensures that the LCE knock-on effects of aerodynamically-motivated design decisions are fully accounted for. Subsequently, the methodology is used to perform the first, to the knowledge of the authors, aero-structural LCE-driven design optimisation of a vehicle subsystem, with the impact of the materials’ circularity potential being taken into account through various end-of-life (EOL) processing scenarios, including recycling. The results show that the environmental footprint of light-duty vehicles could significantly be reduced through integrative early-stage design. Specifically, it shows that a life cycle energy optimal vehicle's aerodynamic shape is significantly impacted by the vehicle's material composition and the latter's EOL characteristics — particularly recycling potential. Furthermore, LCE optimal vehicles have been found to be on average longer, heavier and more aerodynamic than their lightweight counterparts, as well as offering up to 20% energy savings per vehicle; while also being shorter and lighter than optimal aerodynamic configurations.
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| 6. |
- Frogner-Kockum, Paul, et al.
(author)
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Metal contaminant fluxes across the sediment water interface
- 2016
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In: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X. ; 111:1-2, s. 321-329
-
Journal article (peer-reviewed)abstract
- To date,most estimates of contaminant fluxes across the sediment/water interface in risk assessments have been done using diffusive flux models. However, the reliability of these is limited as the overall flux from the sediment may have contributions caused by advection and bioturbation. We found through a comparison of modelled fluxes versus measured fluxes, that the methods Benthic Flux Chamber and surface leaching tests in a risk assessment context showed similar magnitude while calculated fluxes deviated at least by a factor of 100 from measured fluxes. This may be explained by the flux contribution in connection with bioturbation. The chambermeasured fluxes of copper were low compared to those of zinc and cobalt, but this is consistent with leaching tests that indicated copper to be more strongly bound. Risk assessments based on total concentrations may be misleading.
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| 7. |
- Göransson, Anna-Lena, et al.
(author)
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Dissecting the Aggregation Events of Alzheimer’s disease Associated Aβ peptide Variants by the Combined use of Different Fluorescent Probes
-
Other publication (other academic/artistic)abstract
- The formation of soluble prefibrillar oligomeric species of the amyloid β peptide (Aβ) has been implicated as a causative agent in the development of Alzheimer’s disease (AD). It is therefore important to characterize the properties of these aggregates, which precede the formation of amyloid fibrils. We studied the in vitro aggregation process of two Aβ40 peptide variants through the combined use of four different fluorescent probes and transmission electron microscopy. Previous studies have shown that these two studied Aβ40 variants exhibit different levels of neurodegeneration when expressed in the central nervous system of Drosophila melanogaster. In the present study, we demonstrate distinct differences in aggregate morphology and their binding properties to different fluorescent probes during in vitro fibrillation of these Aβ peptides. Our results indicate a potential link between the observed neurodegenerative properties and the biophysical properties of distinct aggregated Aβ species.
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| 8. |
- Jank, Merle-Hendrikje, et al.
(author)
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Advancing energy efficient early-stage vehicle design through inclusion of end-of-life phase in the life cycle energy optimisation methodology
- 2017
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In: 12th International Conference on Ecological Vehicles and Renewable Energies Conference, EVER.
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Conference paper (peer-reviewed)abstract
- Environmentally-friendly energy-efficient vehicles are an important contributor to meet future global transportation needs. To minimise the environmental impact of a vehicle throughout its entire life cycle, the life cycle energy optimisation (LCEO) methodology has been proposed. Using the proxy of life cycle energy, this methodology balances the energy consumption of vehicle production, operation and end-of-life scenarios. The overall aim is to design a vehicle where life cycle energy is at a minimum. While previous work only included vehicle production and operation, this paper aims at advancing the LCEO methodology by including an end-of-life phase. A simplified design study was conducted to illustrate how vehicle design changes when end-of-life treatment is included. Landfilling, incineration and recycling have been compared as end-of-life treatments, although the focus was put on recycling. The results reveal that the optimal design not only changes with the inclusion of an end-of-life phase but it changes with specific end-of-life treatment.
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| 9. |
- Schöggl, Josef-Peter, et al.
(author)
-
A design-theoretic review of Sustainable Product Development literature
- 2019
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In: 22nd International Conference on Sustainable Innovation.
-
Conference paper (other academic/artistic)abstract
- Improving the socio-ecological performance of products in the design stage is essential for achieving sustainable patterns of production and consumption in line with the aims of the UN Sustainable Development Goals or the EU Action Plan for a Circular Economy. However, the uptake of available methods for sustainable product development (SPD) in practice is still low. Therefore, this paper explores if and how the integration of such methods with theories and models of design can contribute to overcoming the lagging adoption of SPD practices. The systematic review that was conducted on the intersection SPD and design theory research reveals that out of 2849 peer-reviewed publications on SPD, only 27 have a design-theoretic foundation. In fact, only the Theory of Inventive Problem Solving (TRIZ) and Axiomatic Design were utilised in SPD methods. The majority of the reviewed publications address cross-functional conflicts and provide exemplary cases but mainly focus on environmental aspects. Adoptions on a large scale are not reported. We conclude that underpinning SPD methods with theories and models of design constitutes a considerable research gap and that the addressing of it has the potential to further advance their integration with conventional engineering and design tasks.
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| 10. |
- Schöggl, Josef-Peter, et al.
(author)
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Barriers to sustainable and circular product design : A theoretical and empirical prioritisation in the European automotive industry
- 2024
-
In: Journal of Cleaner Production. - 0959-6526 .- 1879-1786. ; 434
-
Journal article (peer-reviewed)abstract
- Despite the increasing availability of tools and methods for sustainable and circular product design (DfS), their uptake in practice is slow. This is also true in the automotive industry, where DfS is an important measure for addressing the industry's negative environmental and social impacts. To facilitate DfS implementation, this paper uses an analytic hierarchy process (AHP) and offers, for the first time, a classification and prioritisation of the barriers that need to be overcome when implementing DfS into vehicle development processes. Based on a systematic literature review and on an expert workshop, the top 15 DfS barrier factors were derived and divided equally into five groups, following a multi-level structure. These factors and groups formed the input for a survey-based analytic hierarchy process with 38 European industry experts. The results show that strategic issues are the most important barriers, followed by the group of operational, personal, external, and tool-related barriers. Among the 15 barrier factors identified, the top five were (1) an unclear link to profitability, (2) lack of top management support, (3) difficulties in handling trade-offs, (4) high operational costs, and (5) a lack of integration of DfS into corporate strategy. The results indicate that while external constraints already exert pressure on automotive companies, they still face particular challenges when attempting to integrate sustainability into corporate strategies and in transferring such strategies to DfS activities at the operational level. The study results may be used to inform managerial policy and further research.
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| 11. |
- Tapper, Sofie, 1989-, et al.
(author)
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A pilot study of essential tremor: cerebellar GABA+/Glx ratio is correlated with tremor severity
- 2020
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In: Cerebellum & ataxias. - : BioMed Central. - 2053-8871. ; 7
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Journal article (peer-reviewed)abstract
- Essential tremor is a common movement disorder with an unclear origin. Emerging evidence suggests the role of the cerebellum and the thalamus in tremor pathophysiology. We examined the two main neurotransmitters acting inhibitory (GABA+) and excitatory (Glx) respectively, in the thalamus and cerebellum, in patients diagnosed with severe essential tremor. Furthermore, we also investigated the relationship between determined neurotransmitter concentrations and tremor severity in the essential tremor patients.
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| 12. |
- Aare, Sudhakar, et al.
(author)
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Mechanisms underlying the sparing of masticatory versus limb muscle function in an experimental critical illness model
- 2011
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In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 43:24, s. 1334-1350
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Journal article (peer-reviewed)abstract
- Acute quadriplegic myopathy (AQM) is a common debilitating acquired disorder in critically ill intensive care unit (ICU) patients which is characterized by tetraplegia/generalized weakness of limb and trunk muscles. Masticatory muscles, on the other hand, are typically spared or less affected, yet the mechanisms underlying this striking muscle-specific difference remain unknown. This study aims to evaluate physiological parameters and the gene expression profiles of masticatory and limb muscles exposed to factors suggested to trigger AQM, such as mechanical ventilation, immobilization, neuromuscular blocking agents (NMBA), corticosteroids (CS) and sepsis for five days by using a unique porcine model mimicking the ICU conditions. Single muscle fiber cross-sectional area and force-generating capacity, i.e., maximum force normalized to fiber cross-sectional area (specific force), revealed maintained masseter single muscle fiber cross-sectional area and specific-force after five days exposure to all triggering factors. This is in sharp contrast to observations in limb and trunk muscles, showing a dramatic decline in specific force in response to five days exposure to the triggering factors. Significant differences in gene expression were observed between craniofacial and limb muscles, indicating a highly complex and muscle specific response involving transcription and growth factors, heat shock proteins, matrix metalloproteinase inhibitor, oxidative stress responsive elements and sarcomeric proteins underlying the relative sparing of cranial versus spinal nerve innervated muscles during exposure to the ICU intervention.
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| 13. |
- Alkmim, M. H., et al.
(author)
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Model-based acoustic characterisation of muffler components and extrapolation to inhomogeneous thermal conditions
- 2018
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In: Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics. - : KU Leuven - Departement Werktuigkunde. - 9789073802995 ; , s. 3009-3020
-
Conference paper (peer-reviewed)abstract
- A methodology for evaluating the acoustic behaviour of two-port inhomogeneous media in experimentally unavailable thermal conditions is proposed. The method consists of an inverse estimation of the geometrical and material properties of the object at room temperature followed by a forced thermal input. The properties of interest for the inverse estimation are the spatially-varying cross-section and/or bulk properties. The underlying model relies on a transfer matrix approach, allowing for a representation of spatially inhomogeneous objects as piece-wise equivalent homogeneous fluids, while ensuring continuity conditions between successive elements. A model of non-stationary thermal conduction is used as a first approximation, where an integral formulation accounts for the cumulative effect of multiple homogeneous elements. In order to evaluate the validity of the extrapolation, a validation against a fully numerical simulation is presented in two cases, namely a simple expansion chamber and a complex muffler.
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| 14. |
- Alonso, Fabiola, et al.
(author)
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Investigation into Deep Brain Stimulation Lead Designs : A Patient-Specific Simulation Study
- 2016
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In: Brain Sciences. - : MDPI. - 2076-3425. ; 6:3, s. 1-16
-
Journal article (peer-reviewed)abstract
- New deep brain stimulation (DBS) electrode designs offer operation in voltage and current mode and capability to steer the electric field (EF). The aim of the study was to compare the EF distributions of four DBS leads at equivalent amplitudes (3 V and 3.4 mA). Finite element method (FEM) simulations (n = 38) around cylindrical contacts (leads 3389, 6148) or equivalent contact configurations (leads 6180, SureStim1) were performed using homogeneous and patient-specific (heterogeneous) brain tissue models. Steering effects of 6180 and SureStim1 were compared with symmetric stimulation fields. To make relative comparisons between simulations, an EF isolevel of 0.2 V/mm was chosen based on neuron model simulations (n = 832) applied before EF visualization and comparisons. The simulations show that the EF distribution is largely influenced by the heterogeneity of the tissue, and the operating mode. Equivalent contact configurations result in similar EF distributions. In steering configurations, larger EF volumes were achieved in current mode using equivalent amplitudes. The methodology was demonstrated in a patient-specific simulation around the zona incerta and a “virtual” ventral intermediate nucleus target. In conclusion, lead design differences are enhanced when using patient-specific tissue models and current stimulation mode.
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| 15. |
- Amin, Muhammad, 1979, et al.
(author)
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CMOS compatible on-chip decoupling capacitor based on vertically aligned carbon nanofibers
- 2015
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In: Solid-State Electronics. - : Elsevier BV. - 0038-1101. ; 107, s. 15-19
-
Journal article (peer-reviewed)abstract
- On-chip decoupling capacitor of specific capacitance 55 pF/mu m(2) (footprint area) which is 10 times higher than the commercially available discrete and on-chip (65 nm technology node) decoupling capacitors is presented. The electrodes of the capacitor are based on vertically aligned carbon nanofibers (CNFs) capable of being integrated directly on CMOS chips. The carbon nanofibers employed in this study were grown on CMOS chips using direct current plasma enhanced chemical vapor deposition (DC-PECVD) technique at CMOS compatible temperature. The carbon nanofibers were grown at temperature from 390 degrees C to 550 degrees C. The capacitance of the carbon nanofibers was measured by cyclic voltammetry and thus compared. Futhermore the capacitance of decoupling capacitor was measured using different voltage scan rate to show their high charge storage capability and finally the cyclic voltammetry is run for 1000 cycles to assess their suitability as electrode material for decoupling capacitor. Our results show the high specific capacitance and long-term reliability of performance of the on-chip decoupling capacitors. Moreover, the specific capacitance shown is larger for carbon nanofibers grown at higher temperature.
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| 16. |
- Amin, Muhammad, 1979, et al.
(author)
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Low temperature and cost-effective growth of vertically aligned carbon nanofibers using spin-coated polymer-stabilized palladium nanocatalysts
- 2015
-
In: Science and Technology of Advanced Materials. - : Informa UK Limited. - 1468-6996 .- 1878-5514. ; 16:1
-
Journal article (peer-reviewed)abstract
- We describe a fast and cost-effective process for the growth of carbon nanofibers (CNFs) at a temperature compatible with complementary metal oxide semiconductor technology, using highly stable polymer-Pd nanohybrid colloidal solutions of palladium catalyst nanoparticles (NPs). Two polymer-Pd nanohybrids, namely poly(lauryl methacrylate)-block-poly((2-acetoacetoxy) ethyl methacrylate)/Pd (LauMA(x)-b-AEMA(y)/Pd) and polyvinylpyrrolidone/Pd were prepared in organic solvents and spin-coated onto silicon substrates. Subsequently, vertically aligned CNFs were grown on these NPs by plasma enhanced chemical vapor deposition at different temperatures. The electrical properties of the grown CNFs were evaluated using an electrochemical method, commonly used for the characterization of supercapacitors. The results show that the polymer-Pd nanohybrid solutions offer the optimum size range of palladium catalyst NPs enabling the growth of CNFs at temperatures as low as 350 degrees C. Furthermore, the CNFs grown at such a low temperature are vertically aligned similar to the CNFs grown at 550 degrees C. Finally the capacitive behavior of these CNFs was similar to that of the CNFs grown at high temperature assuring the same electrical properties thus enabling their usage in different applications such as on-chip capacitors, interconnects, thermal heat sink and energy storage solutions.
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| 17. |
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| 18. |
- Andersson-Sköld, Yvonne, 1957-, et al.
(author)
-
Ramverk för att prioritera och bedöma nyttan av klimatanpassningsåtgärder
- 2023
-
Reports (other academic/artistic)abstract
- Klimatförändringarna är idag påtagliga och även om vi snabbt får ner utsläppen av växthusgaser kommer fler, mer omfattande och mer kostsamma klimatrelaterade händelser att inträffa alltmer ofta. Kostnaderna inom den svenska transportsektorn för klimatrelaterade händelser som skadar gator, vägar, spår-/järnväg, med flera sårbara delar av infrastrukturen är stora redan idag och förväntas öka. Översvämningar, bränder och skador till följd av väderrelaterade händelser på anläggningar resulterar bland annat i minskad framkomlighet och en ökad risk för olyckor. För att upprätthålla transportsystemets funktion är det därför viktigt att vi vidtar riskreducerande åtgärder för att minska sannolikheten och omfattningen av negativa konsekvenser av både dagens klimat- och väderrelaterade händelser men framför allt för att hantera framtida klimatrelaterade händelser. Det är nödvändigt att säkerställa transportsystemets funktion vid extrema väderhändelser, och under perioder av långvarig nederbörd, långvariga värmeböljor och förändrade nederbördsmönster. Det gäller också att redan idag möjliggöra anpassningsåtgärder för att hantera långsiktiga förändringar som höjd havsvattennivå och grundvattennivåer, som påverkar infrastrukturens framkomlighet och livslängd.I denna rapport presenteras sammanfattande resultat och en sammanfattning av hur ett ramverk för att utvärdera klimatrelaterade effektsamband har använts. Med effektsamband avses att identifiera, bedöma och värdera klimatrelaterade risker och riskreducerande åtgärder. I denna rapport är fokus på att identifiera, bedöma och utvärdera effektiviteten av klimatrelaterade åtgärder. Resultatet av det framtagna ramverket kan användas för att analysera riskreducerande åtgärders effekter, det vill säga för att bedöma om det är relevant att genomföra en åtgärd, när i tiden den bör genomföras samt för att bedöma vilken åtgärd som är mest relevant att genomföra. De risker som beaktas genom fallstudier innefattar brandrisk, olycksrisk på gator och vägar på grund av nollgenomgångar eller värme, översvämning, erosion och skred och påverkan på vägkonstruktionen (spårbildning, bärighet och utmattning), solkurvor och risker vid kraftiga vindar. Testerna har innefattat faro- och riskidentifiering, riskanalys, identifiering och utvärdering av möjliga åtgärder. Exempel på fallstudier är Gävleregnet 2021, ett skyfall i Kungsbacka kommun 2019, erosionsrelaterade förändringar under lång tid vid Österdalälven och beräkningar av påverkan av temperatur, fuktighet och förändringar i tjälförändringsmönster på vägkonstruktionen vid E10 vid Svappavaara. I en av de fallstudier som sammanfattas i rapporten redovisas även en monetär värdering och känslighetsanalys. Ramverket har också legat till grund för en diskussion avseende klimatrelaterade risker kopplade till elförsörjning.
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| 19. |
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| 20. |
- Banduseela, Varuna C., et al.
(author)
-
Gene expression and muscle fiber function in a porcine ICU model
- 2009
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In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 39:3, s. 141-159
-
Journal article (peer-reviewed)abstract
- Skeletal muscle wasting and impaired muscle function in response to mechanical ventilation and immobilization in intensive care unit (ICU) patients are clinically challenging partly due to 1) the poorly understood intricate cellular and molecular networks and 2) the unavailability of an animal model mimicking this condition. By employing a unique porcine model mimicking the conditions in the ICU with long-term mechanical ventilation and immobilization, we have analyzed the expression profile of skeletal muscle biopsies taken at three time points during a 5-day period. Among the differentially regulated transcripts, extracellular matrix, energy metabolism, sarcomeric and LIM protein mRNA levels were downregulated, while ubiquitin proteasome system, cathepsins, oxidative stress responsive genes and heat shock proteins (HSP) mRNAs were upregulated. Despite 5 days of immobilization and mechanical ventilation single muscle fiber cross-sectional areas as well as the maximum force generating capacity at the single muscle fiber level were preserved. It is proposed that HSP induction in skeletal muscle is an inherent, primary, but temporary protective mechanism against protein degradation. To our knowledge, this is the first study that isolates the effect of immobilization and mechanical ventilation in an ICU condition from various other cofactors.
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| 21. |
- Banduseela, Varuna, et al.
(author)
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Impaired autophagy, chaperone expression, and protein synthesis in response to critical illness interventions in porcine skeletal muscle
- 2013
-
In: Physiological Genomics. - : American Physiological Society. - 1094-8341 .- 1531-2267. ; 45:12, s. 477-486
-
Journal article (peer-reviewed)abstract
- Critical illness myopathy (CIM) is characterized by a preferential loss of the motor protein myosin, muscle wasting, and impaired muscle function in critically ill intensive care unit (ICU) patients. CIM is associated with severe morbidity and mortality and has a significant negative socioeconomic effect. Neuromuscular blocking agents, corticosteroids, sepsis, mechanical ventilation, and immobilization have been implicated as important risk factors, but the causal relationship between CIM and the risk factors has not been established. A porcine ICU model has been used to determine the immediate molecular and cellular cascades that may contribute to the pathogenesis prior to myosin loss and extensive muscle wasting. Expression profiles have been compared between pigs exposed to the ICU interventions, i.e., mechanically ventilated, sedated, and immobilized for 5 days, with pigs exposed to critical illness interventions, i.e., neuromuscular blocking agents, corticosteroids, and induced sepsis in addition to the ICU interventions for 5 days. Impaired autophagy as well as impaired chaperone expression and protein synthesis were observed in the skeletal muscle in response to critical illness interventions. A novel finding in this study is impaired core autophagy machinery in response to critical illness interventions, which when in concert with downregulated chaperone expression and protein synthesis may collectively affect the proteostasis in skeletal muscle and may exacerbate the disease progression in CIM.
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| 22. |
- Bjursell, Cecilia, 1970-, et al.
(author)
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Välmående, delaktighet och bildning – panelsamtal [video]
- 2021
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Other publication (film/video) (pop. science, debate, etc.)abstract
- I samband med Encells 20-årsjubileum hölls ett seminarium med titeln 'Livslångt lärande för välbefinnande, mångfald och delaktighet'. Programmet spelades in och här hittar du femte delen, där Cecilia Bjursell modererar ett panelsamtal om välmående, delaktighet och bildning.
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| 23. |
- Bouchouireb, Hamza, et al.
(author)
-
A preliminary investigation of robust design and uncertainty quantification within the life cycle energy optimisation methodology
- 2021
-
In: Resource Efficient Vehicles Conference, rev2021.
-
Conference paper (other academic/artistic)abstract
- The Life Cycle Energy Optimisation (LCEO) methodology aims at finding a design solution that uses a minimum amount of cumulative energy demand over the different phases of the vehicle's life cycle, while complying with a set of functional constraints. This effectively balances trade-offs, and therewith avoids sub-optimal shifting between the energy demand for the cradle- to-production of materials, operation of the vehicle, and end-of-life phases. The present work describes the inclusion of robust design aspects and uncertainty quantification into the LCEO framework. In particular, uncertainty is introduced through the assumption that the material and energy properties of a subset of the optimisation’s candidate materials are described by statistical distributions as opposed to a priori fixed values. Subsequently, the nature of the LCEO-associated optimisation problem is changed from deterministic to stochastic. This change is handled by defining a multilevel representation hierarchy, and using the Multilevel Monte Carlo (MLMC) approach in the optimisation process to evaluate the expected compliance of a given design with the transport-related functional requirements. The extended framework is applied to the robust design optimisation of a subsystem of a vehicle model which is both mechanically and geometrically constrained. The ability of the LCEO methodology to include robust design aspects early during the vehicle design process, while simultaneously handling functional conflicts, to result in a robust life cycle energy optimal design is demonstrated. Furthermore, the performance increase obtained by the use of the MLMC approach instead of the classical Monte Carlo approach within an optimisation under uncertainty framework is illustrated.
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| 24. |
- Bouchouireb, Hamza, 1991-
(author)
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Advancing the life cycle energy optimisation methodology
- 2019
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Licentiate thesis (other academic/artistic)abstract
- The Life Cycle Energy Optimisation (LCEO) methodology aims at finding a design solution that uses a minimum amount of cumulative energy demand over the different phases of the vehicle's life cycle, while complying with a set of functional constraints. This effectively balances trade-offs, and therewith avoids sub-optimal shifting between the energy demand for the cradle-to-production of materials, operation of the vehicle, and end-of-life phases. This work further develops the LCEO methodology and expands its scope through three main methodological contributions which, for illustrative purposes, were applied to a vehicle sub-system design case study.An End-Of-Life (EOL) model, based on the substitution with a correction factor method, is included to estimate the energy credits and burdens that originate from EOL vehicle processing. Multiple recycling scenarios with different levels of assumed induced recyclate material property degradation were built, and their impact on the LCEO methodology's outcomes was compared to that of scenarios based on landfilling and incineration with energy recovery. The results show that the inclusion of EOL modelling in the LCEO methodology can alter material use patterns and significantly effect the life cycle energy of the optimal designs.Furthermore, the previous model is expanded to enable holistic vehicle product system design with the LCEO methodology. The constrained optimisation of a vehicle sub-system, and the design of a subset of the processes which are applied to it during its life cycle, are simultaneously optimised for a minimal product system life cycle energy. In particular, a subset of the EOL processes' parameters are considered as continuous design variables with associated barrier functions that control their feasibility. The results show that the LCEO methodology can be used to find an optimal design along with its associated ideal synthetic EOL scenario. Moreover, the ability of the method to identify the underlying mechanisms enabling the optimal solution's trade-offs is further demonstrated.Finally, the functional scope of the methodology is expanded through the inclusion of shape-related variables and aerodynamic drag estimations. Here, vehicle curvature is taken into account in the LCEO methodology through its impact on the aerodynamic drag and therewith its related operational energy demand. In turn, aerodynamic drag is considered through the estimation of the drag coefficient of a vehicle body shape using computational fluid dynamics simulations. The aforementioned coefficient is further used to estimate the energy required by the vehicle to overcome aerodynamic drag. The results demonstrate the ability of the LCEO methodology to capitalise on the underlying functional alignment of the structural and aerodynamic requirements, as well as the need for an allocation strategy for the aerodynamic drag energy within the context of vehicle sub-system redesign.Overall, these methodological developments contributed to the exploration of the ability of the LCEO methodology to handle life cycle and functional trade-offs to achieve life cycle energy optimal vehicle designs.
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- Bouchouireb, Hamza, 1991-, et al.
(author)
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Exploring the aero-structural-battery energy storage coupling within the early-stage development of life cycle energy optimal electric vehicles
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Other publication (other academic/artistic)abstract
- The Life Cycle Energy Optimisation (LCEO) methodology is used to explore the coupling existing between an electric vehicle's aerodynamic shape, structural material composition and design, and the properties of its onboard battery's chemistry in order to enable the development of more sustainable vehicle configurations. To this end, a mixed integer nonlinear programming formulation of the LCEO methodology was developed to include the effects of battery energy storage systems on the Life Cycle Energy (LCE) optimal vehicle designs. In particular, the vehicle's battery size and number of such batteries needed over its life cycle were introduced as variables subject to a range and a battery cycle life constraint. The former is derived from the battery-capacity-to-structural-mass ratio of recent production vehicles, while the latter ensures that the batteries' cycle lives are sufficient for the entirety of the vehicle's use phase. Additionally, three lithium-based battery chemistries with varying properties were included: lithium nickel manganese cobalt oxide (NMC), lithium iron phosphate (LFP) and lithium cobalt oxide (LCO); along with a closed-loop end-of-life recycling scenario for the battery materials. The results of the coupled aero-structural-battery energy storage LCE-driven design optimisations demonstrate that battery chemistry and recycling potential have a significant impact on the system's design in terms of overall LCE footprint, battery size and number, as well as aerodynamic shape. More specifically, a change in battery composition was found to lead to up to 12.5% variation in drag coefficient, while battery recycling can on average reduce a vehicle's associated LCE by 32%. Furthermore, battery material recycling was found to decrease the role played by the specific energy and cycle lives of the batteries, and increase that played by their embodied energy. Consequently, the LFP battery chemistry was found to be the best performer from an LCE perspective in the presence of battery material recycling; while the NMC chemistry was found to perform marginally better in the absence of the latter.
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