EFFECT OF RACCOON (PROCYON LOTOR) REDUCTION ON BLANDING’S TURTLE (EMYDOIDEA BLANDINGII) NEST SUCCESS

The Lake County Forest Preserve District has monitored a state-endangered Blanding’s Turtle (Emydoidea blandingii) population at two adjoining nature preserves along the Illinois–Wisconsin border since 2004. Prior to predator management, 92.3% of documented and unprotected natural Blanding’s Turtle nests (12 of 13) and 88% of monitored artificial nests have been at least partially depredated. The goal of this study was to determine the efficacy of subsidized Raccoon (Procyon lotor) removal efforts in increasing the nest success of Blanding’s Turtles. During April–May 2013 and 2014, we captured and euthanized 78 Raccoons from our 2 km2 study area. We estimated pre-removal abundance estimates using the Leslie depletion method; it appeared that we removed 83–89% of the Raccoons from the study area each year and pre-removal density estimates were 37.5% lower in 2014 than 2013. During the study period, we monitored 22 Blanding’s Turtle in situ unprotected nests. In 2013, one of seven (14%) Blanding’s Turtle nests was partially depredated and no nests were completely depredated, indicative of a successful impact of Raccoon removal on Blanding’s Turtle nest success. However in 2014, nine of 15 (60%) Blanding’s Turtle nests were depredated. Our results provide some evidence that removal of Raccoons may have increased Blanding’s Turtle nest success but other factors, such as a functional response of surviving Raccoons or depredation by other subsidized predators may be contributing to decreased nest success

Electrical transport properties of bulk MgB2 materials synthesized by the electrolysis on fused mixtures of MgCl2, NaCl, KCl and MgB2O4

Electrolysis was carried out on fused mixtures of MgCl2, NaCl, KCl and MgB2O4 under an Ar flow at 600C. Electrical resistivity measurements for the grown deposits show an onset of superconducting transition at 37 K in the absence of applied magnetic field. The resistivity decreases down to zero below 32 K. From an applied-field dependence of resistivity, an upper critical field and a coherence length were calculated to be 9.7 T and 5.9 nm at 0 K, respectively

Measurements of crossed-field demagnetisation rate of trapped field magnets at high frequencies and below 77 K

Design requirements of next generation electric aircraft place stringent requirements on the power density required from electric motors. Future prototype planned in the scope of European project “Advanced Superconducting Motor Experimental Demonstrator” ASuMED considers a permanent magnet synchronous motor, where the conventional ferromagnets are replaced with superconducting trapped field magnets, which promise higher flux densities and thus higher output power without adding weight. Previous work has indicated that stacks of tape show lower cross-field demagnetisation rate to bulk (RE)BCO whilst retaining similar performance for their size, however the crossed-field demagnetisation rate has not been studied in the temperature, magnetic field and frequency range that is relevant for the operational prototype motor. This work investigates crossed-field demagnetisation in 2G HTS stacks at temperatures below 77 K and frequency range above 10 Hz. This information is crucial in developing designs and determining operational time before re-magnetisation could be required

Energy Storage Technology for Decentralised Energy Management: Future Prospects

The chapter provides a comparison of energy storage technologies in decentralised energy systems for energy management. The various costs, advantages and disadvantages of the storage technologies will be considered. System dynamics modelling will be used to analyse energy management within the decentralised renewable and storage systems. Additionally, the integration of hydrogen storage technology and the use of hydrogen as an energy carrier in a decentralised airport scenario will be highlighted and the arising advantages of a decentralised airport using novel electric planes powered by hydrogen are discussed

Effect of aromatic hydrocarbon addition on in situ powder-in-tube processed MgB2 tapes

We fabricated in situ powder-in-tube processed MgB2/Fe tapes using aromatic hydrocarbon of benzene, naphthalene, and thiophene as additives, and investigated the superconducting properties. We found that these aromatic hydrocarbons were very effective for increasing the Jc values. The Jc values of 20mol% benzene-added tapes reached 130A/mm2 at 4.2K and 10T. This value was almost comparable to that of 10mol% SiC-added tapes and about four times higher than that of tapes with no additions. Microstructure analyses suggest that this Jc enhancement is due to both the substitution of carbon for boron in MgB2 and the smaller MgB2 grain size.Comment: 6 pages, 4 figure

Modeling of Trapped Fields by Stacked (RE)BCO Tape Using Angular Transversal Field Dependence

Stacks of superconducting (RE)BCO tape are gaining popularity as a potential alternative for superconducting bulks for trapped field applications. This is partly due to versatility and uniformity of the starting material, allowing for more deterministic prediction of field profile and magnitude. However, most FEM models of trapped field magnets do not incorporate parameters such as critical current and n-value dependence on the angle of applied magnetic field, leading to only qualitative modeling results. More quantitative results can be obtained from incorporating more data for superconductivity and thermal properties of the material. Such models can be used as a starting point for most geometries and both trapped field and current transport modeling problems. An FEM model of a stack of tapes was constructed using the H formulation, incorporating goniometric critical current and n-value measurements. The modeling results were compared to field cooling experiments for stacks of different heights. The experiment and modeling show good agreement.This work was supported in part by the Engineering and Physical Sciences Research Council, U.K., and in part by SKF S2M, France

Techno-economic study of output-flexible light water nuclear reactor systems with cryogenic energy storage

This study explores whether a nuclear power plant can be combined with a cryogenic energy storage plant to allow the resultant facility to provide variable power to the grid. The study expands on previous literature by performing novel market-led system optimisation to best design the output profile of the plant to improve economic performance in the UK electricity grid. There are three key conclusions that emerge from this study. The current UK electricity market favours plant designs with rapid discharge rate. Provided that the capital cost expectations of the NuScale SMR are realised, strike prices of £55/MWh are sufficient to ensure a return on investment. However, the case for storage remains weak and only becomes viable in extreme spot market conditions