Search results for "environment"
showing 10 items of 28487 documents
Performance Improvement of Grid-Integrated Doubly Fed Induction Generator under Asymmetrical and Symmetrical Faults
2023
The doubly fed induction generator (DFIG)-based wind energy conversion system (WECS) suffers from voltage and frequency fluctuations due to the stochastic nature of wind speed as well as nonlinear loads. Moreover, the high penetration of wind energy into the power grid is a challenge for its smooth operation. Hence, symmetrical faults are most intense, inflicting the stator winding to low voltage, disturbing the low-voltage ride-through (LVRT) functionality of a DFIG. The vector control strategy with proportional–integral (PI) controllers was used to control rotor-side converter (RSC) and grid-side converter (GSC) parameters. During a symmetrical fault, however, a series grid-side converter…
Development of herbicide-resistant varieties of foxtail millet
2012
International audience; Developing herbicide resistance in forsaken small crops could be a way to maintain food and cultivation system diversity, otherwise they would disappear due to the impossibility or cost to control the weeds. It is the case with foxtail millet, Setaria italica, a small grain, preferentially autogamous, C4 cereal. Three different herbicide-resistant materials were developed using wild germplasm resources. They allowed: 1) to better characterize the resistance mechanisms and inheritance; 2) provide plant materials to test the efficiency of the crop resistance at field level; and 3) experiment on the possible flow back of the resistance gene to the wild relative and amon…
Effets du bruit marin sur le changement des poissons sparidés juvéniles entre les espèces et les stades de développement
2023
International audience; Marine noise is an emerging pollutant inducing a variety of negative impacts on many animal taxa, including fish. Fish population persistence and dynamics rely on the supply of early life stages, which are often very sensitive to disturbance. Impacts of marine noise pollution (MNP) on juvenile fish have rarely been investigated in temperate regions. This is particularly true for the Mediterranean Sea, which is considered as an MNP hotspot due to intensive maritime traffic. In this study, we investigate the relationship between MNP related to boat traffic and (i) assemblage structure and (ii) the density of juvenile fishes (post-settlers at different stages) belonging…
Sex Allocation Theory for Facultatively Sexual Organisms Inhabiting Seasonal Environments: The Importance of Bet Hedging
2018
Adaptive explanations for dormancy often invoke bet hedging, where reduced mean fitness can be adaptive if it associates with reduced fitness variance. Sex allocation theory typically ignores variance effects and focuses on mean fitness. For many cyclical parthenogens, these themes become linked, as only sexually produced eggs undergo the dormancy needed to survive harsh conditions. We ask how sex allocation and the timing of sex evolve when this constraint exists in the form of a trade-off between asexual reproduction and sexual production of dormant eggs—the former being crucial for within-season success and the latter for survival across seasons. We show that male production can be tempo…
Velocity-based resistance training: do women need greater velocity loss to maximize adaptations?
2021
Abstract Purpose Men and women typically display different neuromuscular characteristics, force–velocity relationships, and differing strength deficit (upper vs. lower body). Thus, it is not clear how previous recommendations for training with velocity-loss resistance training based on data in men will apply to women. This study examined the inter-sex differences in neuromuscular adaptations using 20% and 40% velocity-loss protocols in back squat and bench press exercises. Methods The present study employed an 8-week intervention (2 × week) comparing 20% vs. 40% velocity-loss resistance training in the back squat and bench press exercises in young men and women (~ 26 years). Maximum strengt…
The Impact of Adolescent Internet Addiction on Sexual Online Victimization: The Mediating Effects of Sexting and Body Self-Esteem
2021
Adolescents’ problematic use of the internet and the risk of sexual online victimization are an increasing concern among families, researchers, professionals and society. This study aimed to analyze the interplay between adolescents’ addiction to social networks and internet, body self-esteem and sexual–erotic risk behavior online: sexting, sextortion and grooming. While sexting refers to the voluntary engagement in texting sexual–erotic messages, sextortion and grooming are means of sexual–erotic victimization through the use of the internet. Participants were 1763 adolescents (51% girls), aged 12 to 16 years (M = 14.56
Development and validation of the Adolescent Sexting Scale (A-SextS) with a Spanish sample
2020
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Inhibition of denitrification and N2O emission by urine-derived benzoic and hippuric acid
2006
Abstract Hippuric acid (HA) in cattle urine acts as a natural inhibitor of soil N2O emissions. As HA concentration varies with diet, we determined critical HA levels. We also tested the hypothesis that the inhibition occurs because the HA breakdown product benzoic acid (BA) inhibits denitrification rates. During a 64-day incubation, we quantified emissions from artificial urine varying in HA, BA and glycine (Gly) concentrations, added to a sandy pasture soil. Increasing HA concentration from 0.4 to 5.6 mmol kg−1 soil significantly decreased the average N2O flux by 54%. At 3.9 mmol kg−1 soil, denitrification levels were 50% reduced for BA as compared to Gly. We conclude that HA inhibits both…
Dual action of phosphonate herbicides in plants affected by herbivore—Model study on black bean aphid Aphis fabae rearing on broad bean Vicia faba pl…
2008
Abstract The interactions between plants, herbicides and herbivore insects were studied as an aspect of possible side effect of the using of phosphonate herbicides. The experimental system was composed of phosphonate herbicides, broad bean Vicia faba (L.) plants and black bean aphid Aphis fabae (Scopoli). Two means of herbicide application, namely standard spraying and direct introduction of the herbicide into stem via glass capillary, were examined. The results obtained for N-2-piridylaminomethylene bisphosphonic acid and its derivatives show 10 times higher inhibition of the plant growth if glass capillary mode was used. When plants were infested by aphids 24 h after the use of herbicide,…
Multiple forms of stakeholder interaction in environmental management: business arguments regarding differences in stakeholder relationships
2010
This study describes and interprets differences in stakeholder interaction as rhetorically constructed in environmental reports and in interviews with environmental managers. It also interprets the role of the natural environment among stakeholders, and discusses how that role is justified or not justified. The study focuses in a business perspective on stakeholder interaction in environmental management. Characteristically, stakeholder studies of environmental management have concentrated on stakeholder influence or the creation of stakeholder management models. In contrast to those, the present study identifies different types of stakeholder relationships: power-based, collaborative, conf…