A hybrid dielectric resonator antenna (HDRA) with a single‐probe generating circular polarization (CP) simultaneously at X and Ku‐bands is presented in this article. A novel hybrid structure of semi‐circular patch and semi‐cylindrical dielectric resonator (DR) of equal radius are combined with a single‐point probe feed to achieve dual‐functional wide CP bands. The asymmetric nature of the semi‐circle and semi‐cylinder produces two orthogonal modes in their respective bands for CP radiation. The measured impedance bandwidth obtained by the proposed structure is 36.49% (3750 MHz) at X‐band and 14.23% (2100 MHz) at the Ku‐band range of frequencies. Axial ratio (AR) bandwidth of 30.39% (3100 MHz) is obtained at X‐band and 13.24% (1950 MHz) at Ku‐band. The measured gains are 9.54 dBic at 9.6 GHz and 6.55 dBic at 15 GHz. An excellent agreement between the computed and measured results validates the design of the dual functional circularly polarized HDRA.
Over the last decades, the increasing intensity of timber harvesting and the changes in forestry practices have impacted the population dynamics of many wildlife species. Moose (Alces alces americana) densities have strongly increased, leading to an extensive pressure on vegetation but also to the growing popularity and socioeconomic benefits of sport hunting. On the south shore of the St. Lawrence River, eastern Québec (Canada), moose densities have been on a constant rise for 3 decades, reaching unprecedented levels due to the absence of its main predator (wolf Canis lupus), conservative sport hunting regulations (females protected 1 year out of 2) and increases in early seral forests induced by logging. Resource managers now need to find the balance between ensuring adequate regeneration of cutblocks and maintaining quality habitat to support the hunting industry, a task that requires identifying the level of use and damages on commercial tree species, and the variables related to such damages. We evaluated the effect of 4 common silvicultural treatments and time elapsed since treatment on proxies of resource use and suitability for moose in the mixed forest of the Bas-Saint-Laurent region. Besides silvicultural treatments, we evaluated the effect of various characteristics – at the stand and landscape scales – on the habitat use of moose and the damage they caused in 440 sampling plots. We found no difference in use and damage between all types of treatment, suggesting that local conditions vary between replicates of a given treatment. At the stand scale, variations of occurrence of browsed commercial and non-commercial stems and severe damages to commercial stems were strongly related to forage diversity, relative nitrogen availability and the proportion of alternative species that are browsed. At the landscape scale, the area occupied by naturally regenerating stands around our sample plots increased the occurrence of severe damages to commercial species. The variations in occurrence and in the number of moose feces were best explained by relative moose density and the proportion of browsed stems. Our results showed the importance of considering stands characteristics to provide quality habitat for moose. We recommend that managers avoid the aggregation of naturally regenerating stands, and prioritize high-density plantations without pre-commercial thinning or low-density plantations to reduce the probability of severe damage by moose. These approaches promote stand diversity, forage quality and availability, and favor quality habitat for moose while ensuring maximum timber yield from planted spruce, which is not targeted by moose browsing.
Objectives Psychosocial stressors at work have been identified as significant risk factors for several mental and physical health problems. These stressors must be compensated by psychosocial resources to prevent or reduce adverse effects on health. Questionnaires measuring these stressors and resources already exist, but none integrate digital stress, ethical culture, and psychosocial safety climate; factors that are increasingly linked to workers’ health. This study aims to develop and establish the psychometric properties of one of the most comprehensive instruments measuring the psychosocial work environment to date: the Occupational Health and Well-being Questionnaire (OHWQ). Study design A cross-sectional validation study is proposed to develop the OHWQ and document its psychometric properties. Methods The OHWQ was developed from validated instruments to which new items were added. The questionnaire includes psychosocial dimensions, along with indicators of psychological distress, musculoskeletal disorders, and well-being. It was administered to a sample of 2770 participants from a population working in the academic field. Exploratory and confirmatory factor analyses and the calculation of Cronbach's α coefficient were used to identify the variables, items, and, dimensions of the OHWQ and to document its main psychometric properties. Results The acceptability of the measurement model was evaluated by the reliability of the items, internal consistency between the items, and the convergent and discriminant validity. Construct validity was assessed using exploratory and confirmatory factor analyses. Using factor analyses and cut-off rules, the new instrument has 124 items grouped into 22 dimensions. The OHWQ demonstrated satisfactory reliability and validity, as well as reasonable fit indices. The internal consistency of the scales was also good (Cronbach's α = 0.68–0.96, median = 0.85). Conclusion The OHWQ demonstrated good psychometric properties. It could be useful for both research purposes and for workplaces interested in developing concrete action plans aimed at improving the balance between psychosocial work stressors and resources.
Rhodamine water tracer (RWT) released during the 2021 Tracer Release Experiment in the St. Lawrence Estuary provides a proxy for the water-soluble fractions of contaminant spills. Measurements of total and size-resolved aerosols were taken onboard a research vessel throughout the experiment. Size-resolved aerosol measurements show airborne transmission of water-soluble RWT in a bimodal distribution peaking at 5.2 μm and 0.9 μm. Highest aerosol RWT (30.5 pg m⁻³) was observed in the 12-hour daytime period following the first dye release (Sept. 5), while the lowest (8.8 pg m⁻³) was observed in the subsequent nighttime sample. Available wind and RWT patch information were used to identify factors contributing to the factor-of-three variation in aerosol RWT concentrations. Negligible correlations were found between aerosol RWT and wind speed and sample time-of-day. Wind direction is isolated as the key variable for consideration in identifying the impact of contaminant spills on coastal and inland communities.
In eastern Canada, the Charlevoix-Kamouraska/Bas-Saint-Laurent (CKBSL) seismic zone presents a seismic hazard almost as high as that of the active Pacific zone. The major event of February 5, 1663 CE, with an estimated magnitude of ≥7, highlights the importance of this seismic hazard. The numerous submarine landslides mapped in the St. Lawrence Estuary in the CKBSL seismic zone suggest that earthquakes triggered series of submarine slope failures. In this context, the SLIDE-2020 expedition on board the RV Coriolis II in the St. Lawrence Estuary aimed to map, image and sample more than 12 zones of submarine instabilities and their associated deposits. The analysis of sediment cores sampled in the distal sedimentary deposits from these landslides reveals the presence of rapidly deposited layers (turbidites, hyperpycnites and debrites) directly linked to the submarine landslides. Dating these landslides with ²¹⁰Pb and ¹⁴C techniques led to the identification of four periods of synchronous submarine landslides corresponding to the strongest historical earthquakes: 1663 CE, 1860/1870 CE, 1925 CE and 1988 CE (M ≥ 7, M = 6.1/6.6, M = 6.2, M = 5.9). This synchronicity over a distance reaching 220 km of several landslides supports a relationship between their triggering in the St. Lawrence Estuary and regional seismicity. The fact that as many as nine submarine landslides appear to have been triggered by the 1663 CE earthquake suggests that this event is the strongest recorded in the last two millennia in the region.
Redfish ( Sebastes mentella and S. fasciatus ) are back at spectacular record high levels in the Gulf of St. Lawrence (GSL) and the effects of this massive resurgence on other components of the food web remain largely unknown. To better understand the trophic implications of the surging redfish biomass within the GSL ecosystem, 3,690 stomachs containing food were collected during two periods: one characterised by low redfish abundance (1993–1999) and the other during a period of record abundance (2015–2019). Taxonomical analysis of stomach contents from individuals of different sizes from three subareas of the GSL was carried out to determine diet composition during both periods. Zooplankton represented the main prey category for small redfish (< 20 cm), which was driven by a predation on amphipods, mostly Themisto sp. in North-East Gulf, in the 1990s and on copepods of the genus Calanus in the deep channels and euphausiids in North-West Gulf in the 2010s. Themisto sp. still dominated the diet of medium (20–30 cm) redfish in the 1990s while the copepods were predominant during the 2010s. Shrimp consumption increased with redfish size and two species were particularly important in large redfish diet (≥ 30 cm) during both periods: pink glass shrimp ( Pasiphaea multidentata ), mostly in the Laurentian Channel and northern shrimp ( Pandalus borealis ), especially in North-East Gulf. Redfish predation on shrimp represents a major concern for the dynamics of the northern shrimp which supports a valuable fishery in the GSL but has been declining in abundance since several years. Piscivory was observed in large redfish diet, with capelin ( Mallotus villosus ) being the major fish prey in the 1990s and redfish (cannibalism) in the 2010s, suggesting density-dependent control at high density of small redfish. By presenting a detailed overview into the redfish diet composition and its temporal variability, the present study offers a first look into the possible future trophic impacts of a resurging groundfish in the GSL ecosystem.
Atlantic herring (Clupea harengus; hereafter herring) is a forage fish that transfers energy from lower to higher trophic levels and sustains high-volume fisheries in the North Atlantic. This study aims to improve our understanding of the ecology of Newfoundland herring and its vulnerability to climate change by identifying key prey items and describing adult herring feeding strategies. We compared plankton assemblages to stomach content and stable isotope analyses from herring collected in Trinity Bay, Newfoundland, in late summer and autumn 2017-2019. Six distinct zooplankton communities were identified across all years, with a shift in community structure in September 2018. This shift coincided with a change from fresher, warmer waters (12-17 • C) to more saline, cooler waters (10.5 • C). The most frequently consumed prey items were amphipods (Themisto spp.) and calanoid copepods (primarily Calanus and Temora spp.). Fish eggs, larvae, and juveniles, primarily identified as capelin, were observed in stomach contents in all years. Fish contributed most to diets in 2017, which corresponded with the peak year for larval densities in Trinity Bay, suggesting that piscivory may increase at higher larval densities. Herring were opportunistic feeders, although some individuals exhibited selective feeding on copepods, amphipods, euphausiids, and the early life stages of fishes. Stable isotope analyses supported the finding that herring piscivory is prevalent in eastern Newfoundland. Given its adaptive feeding strategy and wide range of consumed prey, we conclude that adult Newfoundland herring is resilient to bottom-up changes observed in the environment.
Physical activity (PA) motives are associated with both moderate‐to‐vigorous intensity PA (MVPA) and mental health. Studies examining whether PA motives relate directly to mental health or indirectly through MVPA are lacking. This study examined the direct effect of five PA motives (i.e., enjoyment, competence, fitness, social, appearance) on mental health and their indirect effects through MVPA in adolescents. A total of 424 participants (57.1% females) ages 14‐15 years from the longitudinal MATCH study were included. Mediation analyses, based on the counterfactual framework, assessed the natural direct effect of PA motives on mental health, and the natural indirect effects through MVPA. Separate models were conducted for each PA motive. Natural direct effects were observed for enjoyment (β̂[95%CI] = 2.12 [0.34,3.90]), competence (β̂[95%CI] = 1.58[0.28, 2.88]), fitness (β̂[95%CI] = 1.42[0.04, 2.80]) and social (β̂[95%CI] = 2.32[1.03, 3.60]) motives. No natural direct effects were observed for appearance motives. A natural indirect effect through MVPA was observed for fitness motives, and no other natural indirect effects were found. Interventions and public health strategies in adolescents need to acknowledge the importance of enjoyment, competence social and fitness motives in PA to promote mental health, and integrate specific recommendations on the importance of the reasons why adolescents participate in PA.
A steep decline in the quality and quantity of available climate proxy records before medieval times challenges any comparison of reconstructed temperature and hydroclimate trends and extremes between the first and second half of the Common Era. Understanding of the physical causes, ecological responses and societal consequences of past climatic changes, however, demands highly-resolved, spatially-explicit, seasonally-defined and absolutely-dated archives over the entire period in question. Continuous efforts to improve existing proxy records and reconstruction methods and to develop new ones, as well as clear communication of all uncertainties (within and beyond academia) must be central tasks for the paleoclimate community.
Contexte À notre connaissance, il n'existe pas de questionnaire en français court, simple et validé pour mesurer la consommation de boissons des adolescents. L'objectif était d'adapter et de valider la traduction française d'un questionnaire en anglais développé aux États-Unis qui mesure la consommation de diverses boissons (BEVQ) des adolescents. Méthodes L'adaptation française du BEVQ (AF-BEVQ) comprenait la conversion des unités impériales (onces) en unités métriques (ml) et seuls les items sur la consommation de boissons sucrées, de jus de fruits purs à 100 % et d'eau ont été conservés. L'AF-BEVQ a été revue par sept experts de divers domaines (santé publique, nutrition et sciences comportementales) et prétestée auprès de cinq adolescents afin de vérifier sa clarté. Enfin, 60 adolescents (14-17 ans) provenant de deux régions du Québec (Canada) ont complété l'AF-BEVQ à deux reprises à deux semaines d'intervalle ainsi que deux rappels de 24 heures Web (R24W). La stabilité temporelle de l'AF-BEVQ a été évaluée avec des coefficients intra-classe (ICC) et sa validité à l'aide de corrélations de Spearman (rs) avec la moyenne des deux R24W. Résultats L’âge moyen de l’échantillon, majoritairement composé d'adolescentes (55,6 %), était de 15,3±1,1 ans. L'AF-BEVQ avait une stabilité temporelle acceptable pour les quantités de boissons sucrées (ICC : 0,68; intervalle de confiance [IC] 95 %: 0,46-0,81), de jus de fruits purs à 100 % (ICC : 0,54; IC 95 %: 0,23-0,72) et d'eau (ICC: 0,66; IC 95 %: 0,38-0,81) consommées. Les quantités de boissons sucrées (rs=0,49; p<0,0001), de jus de fruits purs à 100 % (rs=0,38; p=0,0024) et d'eau (rs=0,37; p=0,0034) rapportées dans l'AF-BEVQ étaient significativement corrélées à celles des deux R24W. Discussion/Conclusion L'AF-BEVQ présente des propriétés psychométriques adéquates pour mesurer la consommation de boissons sucrées, de jus de fruits purs à 100 % et d'eau des adolescents francophones, ce qui en fait un outil d'intérêt pour la santé publique et pour d'autres recherches. Déclaration de liens d'intérêts Les auteurs déclarent ne pas avoir de liens d'intérêts.
Optimal management and planning of microgrids (MG) are the most important goals for operators. In this study, a Multiobjective Genetic Algorithm (MOGA) is applied to the technical and economic problems of the MG. This stochastic programming considers demand response (DR) programs, reactive loads, and uncertainties due to renewable energies. Demand-side management (DSM) is how to manage and schedule the generation and consumption with the objective of cost and greenhouse gases (GHG) emissions minimization. In this work, with the contribution of various customers to demand response programs and reserve schedules, a reduction in the operation cost of the microgrid has resulted. This method facilitates obtaining a complete and comprehensive microgrid model for energy management in the power system, and the results demonstrate that participation in demand response programs and reactive loads can reduce generation, reservation, startup costs, and the amount of pollution. Regarding reservation costs, a 16% reduction was obtained in the presence of the load response, and wind power is a good compromise between cost and pollution among various resources.
Anthropogenic disturbances are increasing worldwide, causing wildlife habitat loss, alteration, and fragmentation. In Canada, the decommissioning of linear anthropogenic structures is identified as a promising tool to restore the habitat of threatened populations of boreal caribou (Rangifer tarandus caribou) by reducing food availability for alternate prey and decreasing encounter probabilities with predators. In this study, we monitored the use of 40 km of decommissioned forest roads by caribou, gray wolves (Canis lupus), black bears (Ursus americanus), and moose (Alces americanus) 1–3 years after reclamation, using 232 motion-activated camera traps. We compared four additive treatments (meaning that each successive treatment included the treatment prior): closing the road to human access, decompacting its soil, planting black spruce (Picea mariana) trees, and adding enriched soil. We assessed the influence of treatments, use by other large mammals, and characteristics of the surrounding environment on road use by the four species. Caribou used the planted treatment (which also included closing and decompacting) more than the closed-only (reference) treatment, but treatments did not influence the use of decommissioned roads by bears and moose. We could not assess the use of treated roads by wolves because of low sample size. Road use by caribou declined with local moose density, but increased with local bear density. Caribou were observed more frequently on roads surrounded by regenerating and mature coniferous stands; caribou also preferentially used roads surrounded by wetlands. Our results suggest that the treatment combining road closure, soil decompaction, and tree planting could be beneficial to caribou, highlighting the relevance of including active restoration efforts in caribou conservation programs. We recommend that such a treatment be added to road decommissioning protocols for the conservation of caribou, alongside broad-scale habitat protection.
Sounds from human activities such as shipping and seismic surveys have been progressively invading natural soundscapes and pervading oceanic ambient sounds for decades. Benthic invertebrates are important ecosystem engineers that continually rework the sediment they live in. Here, we tested how low-frequency noise (LFN), a significant component of noise pollution, affects the sediment reworking activities of selected macrobenthic invertebrates. In a controlled laboratory setup, the effects of acute LFN exposure on the behavior of three abundant bioturbators on the North Atlantic coasts were explored for the first time by tracking their sediment reworking and bioirrigation activities in noisy and control environments via luminophore and sodium bromide (NaBr) tracers, respectively. The amphipod crustacean Corophium volutator was negatively affected by LFN, exhibiting lower bioturbation rates and shallower luminophore burial depths compared to controls. The effect of LFN on the polychaete Arenicola marina and the bivalve Limecola balthica remained inconclusive, although A. marina displayed greater variability in bioirrigation rates when exposed to LFN. Furthermore, a potential stress response was observed in L. balthica that could reduce bioturbation potential. Benthic macroinvertebrates may be in jeopardy along with the crucial ecosystem-maintaining services they provide. More research is urgently needed to understand, predict, and manage the impacts of anthropogenic noise pollution on marine fauna and their associated ecosystems.
In the context of global changes, the future dynamics of trembling aspen ( Populus tremuloides Michx.) are uncertain in the middle of its range. An increase in climate-related mortality could occur, but the modification of disturbance regimes could also favor its expansion. In this study, we document trembling aspen dynamics over 40 years at the scale of a boreal forest landscape (10 930 km²), as well as the role of disturbances in these dynamics. The results indicate that trembling aspen has experienced a substantial expansion over the last four decades (+102% occurrence), particularly between 1987 and 1997 (+70.9% occurrence). Nevertheless, these dynamics vary both spatially and temporally, with for example a phase of weak decline since 1997 (−5.9% occurrence). Anthropogenic disturbances, particularly clear-cutting, have played a major role in the expansion of trembling aspen. This expansion could influence the response of ecosystems to climate change, by modifying both fire and insect outbreak activities.
Purpose Successful deprescribing requires understanding the attitudes of older adults and caregivers towards this process. This study aimed to capture these attitudes in four French-speaking countries and to investigate associated factors. Methods A multicenter cross-sectional study was conducted by administrating the French version of the revised Patients’ Attitudes Towards Deprescribing (rPATD) questionnaire in Belgium, Canada, France, and Switzerland. Community-dwelling or nursing home older adults ≥ 65 years taking ≥ 1 prescribed medications and caregivers of older adults with similar characteristics were included. Multivariate logistic regressions were carried out to examine factors associated with willingness to deprescribe. Results A total of 367 older adults (79.3 ± 8.7 years, 63% community-dwelling, 54% ≥ 5 medications) and 255 unrelated caregivers (64.4 ± 12.6 years) of care recipients (83.4 ± 7.9 years, 52% community-dwelling, 69% ≥ 5 medications) answered the questionnaire. Among them, 87.5% older adults and 75.6% caregivers would be willing to stop medications if the physician said it was possible. Reluctance to stop a medication taken for a long time was expressed by 46% of both older adults and caregivers. A low score for the factor “concerns about stopping” (older adults: aOR: 0.21; 95% CI: 0.07–0.59), and a high score for the factor “involvement” (older adults: aOR: 2.66; 95% CI: 1.01–7.07; caregivers: aOR: 11.28; 95% CI: 1.48–85.91) were associated with willingness to deprescribe. Conclusions A significant proportion of older adults and caregivers of French-speaking countries are open to deprescribing. Despite this apparent willingness, deprescribing conversations in clinical practice remains marginal, emphasizing the importance of optimizing the integration of existing tools such as rPATD.
The study objective was to verify whether recreational screen time was associated with sleep quality among adolescents during the third wave of the COVID-19 pandemic in Canada. Data collection took place in four high schools in the region of Chaudière-Appalaches (Quebec, Canada) from the end of April to mid-May 2021. Recreational screen time and sleep quality were measured using the French versions of validated questionnaires specifically designed for adolescents. A total of 258 adolescents (14–18 years; 66.3% girls) answered the online survey. Adolescent boys had a higher total mean recreational screen time (454.3 ± 197.5 vs. 300.5 ± 129.3 min/day, p < 0.0001) and a higher total mean sleep quality score (4.2 ± 0.9 vs. 3.9 ± 0.8, p = 0.0364) compared to girls. Recreational screen time (β = −0.0012, p = 0.0005) and frequency of concurrent screen use (sometimes: β = −0.3141, p = 0.0269; often: β = −0.4147, p = 0.0048; almost always or always: β = −0.6155, p = 0.0002) were negatively associated with sleep quality while being a boy (β = 0.4276, p = 0.0004) was positively associated with sleep quality and age (p = 0.6321) was not. This model explained 16% of the variance in adolescents’ sleep quality. Public health interventions during and after the COVID-19 pandemic should target recreational screen time, concurrent screen use and especially girls to possibly improve sleep quality and promote adolescents’ physical and mental health.
Introduction : La pratique régulière d’activités physiques (AP) peut être bénéfique pour les survivantes du cancer du sein, mais la majorité d’entre elles n’en font pas suffisamment. Les effets secondaires à long terme des traitements oncologiques représentent des barrières à l’adoption de saines habitudes de vie. But : Identifier les facteurs qui influencent l’intention de pratiquer régulièrement des AP modérées chez les survivantes du cancer du sein. Méthodologie : Une étude corrélationnelle a été effectuée auprès de participantes (N=136) du programme Ma Santé Active (my Active Health) à l’aide d’un questionnaire auto-administré conçu selon la théorie du comportement planifié. Résultats : Des analyses de régression multiple montrent que l’attitude, la perception de contrôle, les croyances comportementales et les croyances liées au contrôle sont les déterminants de l’intention. Discussion et conclusion : Il est recommandé de fonder les interventions sur ces déterminants pour renforcer l’intention comportementale des survivantes du cancer du sein. Enfin, l’article renseignera les professionnels de la santé sur les cibles d’intervention à préconiser pour motiver les femmes ayant un diagnostic de cancer du sein à faire régulièrement des AP.
The higher cost of Ag and Au and their resonance frequency shift limitation opened the way to find an alternative solution by developing new nanohybrid antenna based on silicon and silicon dioxide coated with metallic nanoparticles. The latter has been recently solicited as a promising configuration for more large-scale plasmonic utilisation. This work reports a multitude of fascinating new phenomenon on LSPR on silicon antenna wires coated with core-shell nanospheres and the studying of the nanoplasmonics amplifiers to control optical and electromagnetic properties of materials. The LSPR modes and their interaction with the silicon nanowires are studied using numerical methods. The suggested configuration offers resonance covering the UV-visible and NIR regions, making them an adaptable addition to the nanoplasmonics toolbox
The lobe-finned fish, lungfish (Dipnoi, Sarcoptergii), have persisted for ~400 million years from the Devonian Period to present day. The evolution of their dermal skull and dentition is relatively well understood, but this is not the case for the central nervous system. While the brain has poor preservation potential and is not currently known in any fossil lungfish, substantial indirect information about it and associated structures (e.g. labyrinths) can be obtained from the cranial endocast. However, before the recent development of X-ray tomography as a palaeontological tool, these endocasts could not be studied non-destructively, and few detailed studies were undertaken. Here, we describe and illustrate the endocasts of six Palaeozoic lungfish from tomographic scans. We combine these with six previously described digital lungfish endocasts (4 fossil and 2 recent taxa) into a 12-taxon dataset for multivariate morphometric analysis using 17 variables. We find that the olfactory region is more highly plastic than the hindbrain, and undergoes significant elongation in several taxa. Further, while the semicircular canals covary as an integrated module, the utriculus and sacculus vary independently of each other. Functional interpretation suggests that olfaction has remained a dominant sense throughout lungfish evolution, and changes in the labyrinth may potentially reflect a change from nektonic to near-shore environmental niches. Phylogenetic implications show that endocranial form fails to support monophyly of the 'chirodipterids'. Those with elongated crania similarly fail to form a distinct clade, suggesting these two paraphyletic groups have converged towards either head elongation or truncation driven by non-phylogenetic constraints.
In this paper, we explore the improvement of the aerodynamic characteristics of wind turbine blades under stall conditions using passive flow control with slots. The National Renewable Energy Laboratory (NREL) Phase II rotor, for which detailed simulations and experimental data are available, served as a baseline for assessing the flow control system effects. The position and configuration of the slot used as a flow control system were determined using CFD analysis. The 3D-RANS equations are solved with ANSYS FLUENT using the k-ω SST turbulence closure model. The pressure coefficient for different wind speeds for the baseline configuration is compared to the available experimental data. The comparison shows that CFD results were better for the attached flow. The current work consists of a 3-D CFD modeling of a rotating blade equipped with different flow control systems: single-slot (S-S) and two-slots (T-S). The computation provides a better understanding of the influence of these flow control devices on the performance of wind turbine blades, the control of boundary layer separation, and the rotation effect. These control systems increase the power output by over 60% at high wind speeds with large separated boundary layer regions. For the configuration with the control system, the slot has shown its ability to delay the boundary layer separation. However, the improved aerodynamic performance has been proven for medium and high angles of attack where the flow is generally in the stall condition. The addition of the second slot changed the flow behavior, and an improvement was observed compared to the single slot configuration. The results are helpful for the design and development of a new generation of wind turbine blades.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.