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Environmental performance assessment of global crop protection practice
No full textNumerous challenges in achieving sustainability are associated with agricultural practices. It is pivotal to quantify and enhance the sustainability performance of agricultural production systems to effectively address these challenges. The use of chemical pesticides in current crop protection practices, aimed at ensuring food quality and safety, is linked to various impact challenges related to toxicity, particularly affecting non-target organisms in soil, air, and water. It is essential to evaluate the pesticides’ impact on ecosystems by characterizing application patterns at the appropriate level of detail, to combine these with environmental emissions and fate, and to assess related exposure and ecotoxicological effects. Identifying factors driving these impacts is crucial for minimizing chemical pollution related to crop protection products. The present PhD project “Environmental Performance Assessment of Global Crop Protection Practice” aims at creating a scientifically sound foundation for quantifying and evaluating performance baselines and identifying impact reduction options for different crop protection practices, with a focus on three main aspects: (1) Global pesticide use database: develop a globally consistent atlas of more than 1,000 pesticide active ingredients effectively applied across 130 crops and 180 countries between 2016 and 2020, considering information on application methods, crop growth stages, treatment target compartments, and uncertainty information, and imputing missing data using machine learning techniques. (2) Pesticide emission scenarios: provide mass balance-based estimates for pesticide emissions via drift deposition in comparative risk and impact assessment with consideration of drift validity ranges, spray nozzle positions, and drift reduction technologies, for integration into existing emission distribution models. (3) Global freshwater ecotoxicity impacts from pesticide use: develop a global screening assessment of ecotoxicity impacts from agricultural pesticide use combining in a consistent LCIA impact pathway approach application data with emission, multimedia fate, exposure, and effect modeling, and identify impact hotspots across pesticides, crops, and regions.After an introductory chapter, the second chapter introduces an extensive and robust dataset on global pesticide use, offering comprehensive and granular coverage of pesticide usage worldwide. It details the strategic methodologies including data cleaning and harmonization, data imputation, and output generation for developing the global pesticide use database, including a thorough assessment of the mass of pesticides applied globally, the application rate (measured as mass applied per treated area per individual treatment), and the geographic distribution of pesticide usage. Additionally, this chapter conducts a comparative analysis with existing datasets on pesticide usage and anticipates future developments in the field.The third chapter explores the concept of cumulative drift deposition as a means to characterize pesticide emissions. It provides an analysis of drift deposition fractions derived from contemporary drift functions, investigates the impact of buffer zones and spray nozzle positions, and evaluates the consequences of differing assumptions about drift deposition from the field edge to the lower validity limit. Furthermore, this chapter highlights the need for alternative approaches in subsequent research to improve the precision and practicality of drift deposition in emission modelling.The fourth chapter outlines the journey of pesticides from application to their impacts on freshwater ecosystems. This includes emissions, their environmental fate, exposure pathways, and ecotoxicological effects. It offers a detailed exploration of impact pathway modeling, from gathering crucial input data to employing species sensitivity distributions for effect modelling. The chapter concludes by identifying and prioritizing pesticide application scenarios that result in significant environmental impacts. By taking a comprehensive view, it emphasizes the connections between the use of pesticides to their impacts, underlining essential measures for evaluating and reducing the adverse effects of pesticides on freshwater ecosystems.In summary, the PhD project presents global pesticide usage and its environmental emissions, with enhancing the accuracy and reliability of environmental impact evaluations. The adoption of more detailed data, advanced modelling techniques, and comprehensive evaluations within the context of Life Cycle Assessment (LCA) frameworks promises to support more sustainable pest management practices worldwide, making contributions to reducing the environmental footprint of pesticide application
Climate driven response of the Iceland-East Greenland-Jan Mayen capelin distribution
No full textClimate change is altering the distribution of marine organisms worldwide. This may, in turn, affect the overall structure and functioning of ecosystems, sometimes leading to low productive regimes. Pronounced shifts in distribution and migration have been observed for capelin (Mallotus villosus), one of the ecologically and commercially important species in the Arctic. This study attempts to discern whether a relationship existed between the altered capelin dynamics and the changing physical environmental conditions in the Iceland-East Greenland-Jan Mayen region. More specifically, three species distribution models were used to predict hindcasts (pre-shift years 1993-2002) and nowcasts (post-shift years 2003-2019) of capelin distribution based on relationships with temperature, salinity, current speed, net primary productivity, and bathymetry. The predicted probability of occurrence over these two time periods demonstrates that the changing environmental conditions have contributed to the modified distribution of the stock during its late feeding season in autumn and during the onset of spawning season in winter. The multi-model approach used in this study has provided a solid statistical framework to describe the environmental niche of capelin and its potential responses to changing ocean climate
Hygrothermal Assessment of Internally Insulation for Historic Half-Timbered Outer Wall
No full textInternal insulation is generally considered a risky solution regarding the risk of moisture-induced damage such as mould growth and wood decay, and this might particularly be problematic for half-timbered buildings due to the extensive use of wooden elements in the walls. These would be particularly exposed in the case of internal insulation. This study investigates the hygrothermal performance and the theoretical risk of mould growth in critical locations in half-timbered walls fitted with internal insulation through 2D-dimensional hygrothermal simulations. Sev-eral types of insulation systems were investigated, including diffusion-open and diffusion-tight systems. Moreover, the effect of exterior plaster to reduce rain in-trusion was investigated. The results showed potentially critical relative humidity levels at several places inside the half-timbered walls, mainly when using diffu-sion-tight systems. However, the combination with exterior plaster positively af-fected the hygrothermal performance. The direction of the wall is important, as wind-driven rain influences the performance more than the possibility of drying out inwards
An Overvoltage-Averse Model for Renewable Rich AC/DC Distribution Networks Considering the Sensitivity of Voltage Violation Probability
No full textThe increasing renewable generation increase the probability of voltage violation. The spatial and temporal power transfer can be achieved in AC/DC distribution networks based on voltage source converters (VSCs) and energy storage (ES), which can effectively avoid system voltage violation. However, the existing voltage violation mitigation methods in uncertain scenarios are either limited by the long solution time or complex modeling, which are difficult to meet the overvoltage probability reduction requirements of intra-day dispatch. In addition, the power transfer will simultaneously affect interconnected systems because the power is coupled through the VSCs. Overvoltage probability reduction on one line may lead to an increase on the other. This paper proposes a two-stage overvoltage-averse model considering the sensitivity of voltage violation probability. The proposed method analytically depicts the impact of power adjustment on the system overvoltage probability. The day-ahead optimization model is established as chance-constrained model. The intra-day optimization model is established as a quadratic convex model, which can be efficiently solved. Simulation results verify that the method proposed can effectively achieve the overvoltage probability reduction of renewable-rich AC/DC distribution networks
Indoor environmental quality and subjective perceptions in multi-chair dental offices
No full textIndoor environmental quality (IEQ) in multi-chair dental offices is strongly related to treatment effectiveness, patient comfort, and dental professionals’ occupational exposure. This study conducts comprehensive field measurements and questionnaire surveys to assess the IEQ in two multi-chair dental offices of the Periodontal Department (PD) and the Endodontics Department (ED) in a stomatological hospital in Changsha during the transitional season, summer, and winter. It first reveals the IEQ status and then examines its impact on the perceptions of both dental professionals and patients. The results indicate no considerable difference in IEQ between the PD and the ED. For the measurement, the worst IEQ is observed in winter, with air temperature, relative humidity, PM2.5 concentration, and sound pressure level not meeting the prescribed limits. The worst case is for the PM2.5 concentration, where the highest daily average level is 1.6–4.0 times higher than the limit. However, according to the questionnaire surveys, the highest participant satisfaction score of the overall environment is also observed in winter (i.e., 1.0). The inconsistent results reflected from the measurements and surveys demonstrate the complex influence of a multi-parameter environment on subjective perceptions. Additionally, dental professionals as long-term occupants of the dental offices, report a lower level of overall environmental satisfaction (i.e., 0.38) compared to patients (i.e., 0.86), especially regarding air quality and acoustic environment. These findings are important information for improving environmental standards and formulating accurate environmental control methods, which then contribute to enhanced health, well-being, and performance of both dental professionals and patients
Thermodynamic analysis of a novel compressed carbon dioxide energy storage coupled dry methane reforming system with integrated carbon capture
No full textChemical absorption CO2 capture, compressed carbon dioxide energy storage (CCES) and dry reforming of methane (DRM) can be used for continuous carbon capture, storage and utilization. However, CO2 capture is often accompanied by significant energy consumption. Considering the waste high-grade thermal energy at the exit of solar methane reforming, the article proposes a coupled system in which the thermal energy at the exit of the DRM system is used in CCES to improve the system's work capacity, and the remaining heat and the compression heat of the CCES are used for CO2 capture. The study established mathematical models of the three subsystems, performed thermodynamic analyses, and completed experiments on dry reforming of methane. The results show that the coupled system can increase the electro-electric conversion efficiency by 150.49 % reaching 220.33 % and the energy efficiency by 7.25 % reaching 77.09 %. The coupled system can save up to 43.33 % of CO2 capture heat. The DRM subsystem can utilize the higher temperature CO2 in the tail end of the CCES system, and its methane conversion efficiency and solar-fuel efficiency can be increased by 3.54 % and 3.20 % respectively to reach 58.22 % and 61.02 %. And the economic analysis found that the coupled system has better economics
From Promise to Practice:Exploring the gap between inclusion ideals and the everyday work realities of neurodiverse individuals
No full textThis thesis is the result of a three-year Ph.D. project conducted by Laurine Keller at the Centre for Technology Entrepreneurship (DTU Entrepreneurship) at the Technical University of Den-mark (DTU). The project was carried out from August 2021 to July 2024, supervised by Carina Lomberg (DTU) and Nicola Thomas (University of Sheffield). And while the following chapters explain the outcomes of my research, I would like to give you, the reader, insights into why I dedicated three years to the special field of neurodiversity.I am an industrial engineer. By education and by mindset. I was living and breathing systematic, one-size-fits-all solutions before I started this Ph.D. journey; work psychology, organizational behavior, and neurodiversity were not part of my DNA yet. However, there was something going on I could not explain around the communication dynamics in the practical world of product development meetings. Hardcore engineers from different departments often failed to com-municate effectively, seemingly speaking different languages. And while I was aware that due to different cognitive profiles, individuals always tend to have different ways of communication, there was something else. It wasn't just about different communication styles, there was a dis-tinct, underlying aspect to their human interactions. It seemed as if certain members, despite their brilliance, couldn't fully connect or resonate with the rest of the team's dynamic. This dis-connect led to burnout and their eventual departure, leaving behind a sense of "unfinished busi-ness". It was really frustrating, and I wanted to understand what caused this breakdown in hu-man interaction and why it affected the most talented individuals. Neurodiversity offered one nuance of the solution, and I needed to learn more.Dear reader, you must know that social dynamics have always been my passion. Around the age of three, whenever my parents took me out to dinner, I couldn't sit still but had to observe how other restaurant guests interacted. I would stand close to their tables, watching their hands move and their facial expressions change throughout their conversations. Today, I still have the same fascination but have learned to observe in a more discreet manner—less staring, more subtlety.Over time I learned that social interactions in organizations are complex, and most happen sub-consciously. Therefore, I would never claim that my work can in any way explain where those project meetings in my previous employment went wrong. As a reviewer once commented: “Laurine, you are not God, you will not solve society's big problems in three years.” What a bummer. But I hoped that my work could at least give the concept of neurodiversity a louder and clearer message within academic discussions, providing neurodiverse individuals the oppor-tunity to voice their experiences and move beyond old-fashioned labels and the stigma.Practitioners need to understand the potential they are wasting by overlooking the power of inclusive workplace practices. It doesn't take much to listen and learn, but the impact on the mental health of all neurotypes—neurotypical and neurodivergent—can change the lives of many employees. Embracing diversity isn't just a moral imperative; it's a strategic necessity for growth and sustainability in the workplace. Recognizing and utilizing the strengths of neuro-diverse employees can drive creativity and resilience, equipping organizations to better navigate the complexities of today's world.I hope that whoever reads this will be inspired to rethink some of their perceptions of neuro-diverse individuals. Without (neuro-) diversity, humankind will struggle to face the challenges of the 21st century. We need unique, divergent ideas to solve complex problems such as overpop-ulation, global warming, and resource scarcity. We can no longer afford to exclude others based on differences in culture, skin color, gender, or neurological thinking styles. Embracing these differences is essential for our collective progress and survival. Extinction has never been closer than now
A safe space in a strange place: A case study of the safety mechanisms of CrossFit culture
No full textBased on a 1‐year ethnographic case study of a Copenhagen‐based CrossFit gym we demonstrate how an organized training place is made physically, psychologically, and socially safe. This we show empirically by analyzing how the local multi‐sited CrossFit gym ‘CHALK’ maintains its safe space through three organizing mechanisms: (1) coach‐led learning progression and practice of the physical craft of CrossFit exercise, intended to prevent injury; (2) a dynamic relation between ‘Rx’ and ’scaling’, that is, setting universal standards for an exercise (Rx) and adjusting to individual levels of competence (scaling), actively preventing the high intensity workout from becoming high risk and from setting idealized norms that only few can live up to, but feel compelled to pursue nonetheless; (3) an egalitarian culture whose practice enables members to participate regardless of age, gender, ethnicity, socio‐economic class, sexual orientation, and prior exercise experience. Our ethnomethodological approach further allows us to discuss how certain signifiers of difference are recognized but either do not become salient or do not matter in respect to the functional training. Rather, we find and argue for the possibility to engage in ‘tomboy‐ish behavior’ that challenges gender and other identity performances in CHALK. In identifying necessary and sufficient conditions for establishing safe space, the article contributes to extant literature, showing how safe space can emerge as an effect of everyday practice, in contrast to being intentional and declared
Investigation of critical copper release rates for dose optimization of antifouling coatings
No full textAntifouling coatings are applied to ship and boat hulls to prevent the unwanted attachment of marine organisms known as biofouling. Most antifouling coatings do so through toxic means by continuously releasing copper from the paint film to the surrounding water and are thus of environmental concern. Few studies have investigated the minimum dose of copper from an antifouling coating required to inhibit biofouling, commonly referred to as the critical release rate. This study presents a comprehensive investigation into the critical release rates of copper from commercial antifouling coatings in European coastal waters, with study sites in the Atlantic (Arcachon, France), Kattegat (Hundested, Denmark) and Skagerrak (Tjärnö, Sweden). Employing a combination of X-ray Fluorescence (XRF) analysis and visual inspection, this six-month field study has evaluated the efficacy of various antifouling coatings with differing copper contents. The findings of this study indicate that a release rate of 7 μg cm−2 d−1 was sufficient to inhibit macrofoulers at all three sites during static conditions. Results also indicate that the critical release rate is a parameter that coating manufacturers can optimize, as the performance of the coatings was not solely dependent on the copper release rates. The general critical release rate of 7 μg cm−2 d−1 could serve as a benchmark for dose optimization of coatings for both the yacht and ship sectors in the studied waters to reduce their environmental impact. It can also be used as support for decision-makers to phase out coatings with unnecessarily high copper release rates from the market
Combustion of Micron-Sized Iron Particles in a Drop Tube Reactor
No full textCombustion of micron-sized particles of iron, a promising renewable alternative to fossil fuels, was investigated in a drop tube reactor (DTR) under overall lean conditions. A bimodal particle size distribution was observed after combustion: black micron-sized particles consisting of a mixture of iron oxides, with oxidation degrees ranging from 60% to 90%, and reddish fine particles of Fe2O3. The oxidation degree of the products showed no obvious variation with the reactor temperature. The coarse product particles were comparable in size with those of the raw iron particles, independent of temperature. The evaporation of iron represented a mass loss of 1-2%. The primary nm-sized particles agglomerated to form aggregates of the order of 1 µm. A simplified model for the combustion was used to analyze the results. It was based on the Particle Equilibrium Composition approach by van Gool et al. (Appl Energy Combust Sci 2023;13:100115) that assumes the oxidation from Fe to FeO to be limited by external diffusion and further oxidation by thermodynamic equilibrium. The model predicted larger oxidation degrees than observed experimentally. The difference was believed to be due mainly to stratification in the drop tube reactor, resulting in local fuel-rich conditions. The small impact of reactor temperature on the final oxidation stage indicated that diffusion limitations, rather than kinetic barriers, were rate controlling