Hydrodynamic Modelling of Offshore Renewables:Experimental Benchmark Datasets and Numerical Simulation

The transition from fossil fuels to renewable energy sources is critical to reduce greenhouse gas emissions and increase global energy access and security. To harness the abundant renewable energy resources from and at the ocean, the European Union has set ambitious targets to increase its installed capacity of offshore renewable energy technologies by 2050. To reach these targets, the levelized cost of energy of emerging offshore renewables must be reduced in which accurate and efficient hydrodynamic models are paramount to maintain low expenditures and agility throughout the design process.The present dissertation revolves around the hydrodynamic modelling of offshore renewables with emphasis on offshore wind turbines (bottom-fixed and floating) and wave energy converters. To establish credibility of hydrodynamic models, verification and validation are vital. The dissertation presents validation experiments dedicated to the construction of public experimental benchmark datasets as well as numerical studies aimed at improving the understanding of the governing hydrodynamics and the suitability of different hydrodynamic models for selected flow problems. Furthermore, the dissertation accounts for hydrodynamic investigations of the early designs of a large monopile with perforations, to reduce fatigue wave loads, and the wave-activated body of a wave energy converter.The transition from fossil fuels to renewable energy sources is critical to reduce greenhouse gas emissions and increase global energy access and security. To harness the abundant renewable energy resources from and at the ocean, the European Union has set ambitious targets to increase its installed capacity of offshore renewable energy technologies by 2050. To reach these targets, the levelized cost of energy of emerging offshore renewables must be reduced in which accurate and efficient hydrodynamic models are paramount to maintain low expenditures and agility throughout the design process.The present dissertation revolves around the hydrodynamic modelling of offshore renewables with emphasis on offshore wind turbines (bottom-fixed and floating) and wave energy converters. To establish credibility of hydrodynamic models, verification and validation are vital. The dissertation presents validation experiments dedicated to the construction of public experimental benchmark datasets as well as numerical studies aimed at improving the understanding of the governing hydrodynamics and the suitability of different hydrodynamic models for selected flow problems. Furthermore, the dissertation accounts for hydrodynamic investigations of the early designs of a large monopile with perforations, to reduce fatigue wave loads, and the wave-activated body of a wave energy converter

Exposure of Phlebotomus Argentipes to Alpha-Cypermethrin, Permethrin, and DDT Using CDC Bottle Bioassays to Assess Insecticide Susceptibility

Background: Insecticide resistance for sand flies is a concern since sand flies are vectors for Leishmania spp. parasites which cause leishmaniasis affecting millions of people each year. The CDC bottle bioassay is used to assess resistance by comparing known insecticide diagnostic doses and diagnostic times from an insecticide-susceptible population. The objective of this study was to determine diagnostic doses and diagnostic times for α-cypermethrin and the lethal dose for 50% and 90% mortality for α-cypermethrin, permethrin, and DDT for Phlebotomus argentipes. Methods: The CDC bottle bioassays were performed in 1,000 mL glass bottles with 15-25 sand flies from a laboratory strain of insecticide-susceptible P. argentipes. A range of concentrations of α-cypermethrin, permethrin, and DDT were evaluated. Approximately four replicates at each concentration were completed with a 24-hour recovery period after the exposure tests. 24-hour mortality dose-response survival curves were created. A time-to-knockdown test was conducted withα-cypermethrin to determine the diagnostic doses with diagnostic times. Results: α-Cypermethrin had the lowest LD50 and LD90 followed by permethrin and then DDT with the highest values. Diagnostic doses with (diagnostic times) for α-cypermethrin were 7.5 μg/mL (30 minutes), 5.0 μg/mL (35 minutes), and 3.0 μg/mL (45 minutes). Conclusions: The dose-response survival curves, diagnostic doses, and diagnostic times can be utilized by control programs in assessing insecticide resistance in field populations of P. argentipes. The control programs can apply the appropriate insecticide and dose to effectively manage the population. The data presented can also be used a starting point for determining diagnostic doses and diagnostic times for other sand fly species