259 research outputs found

    Cost reductions in nickel-hydrogen battery

    Get PDF
    Significant progress was made toward the development of a commercially marketable hydrogen nickel oxide battery. The costs projected for this battery are remarkably low when one considers where the learning curve is for commercialization of this system. Further developmental efforts on this project are warranted as the H2/NiO battery is already cost competitive with other battery systems

    Patterns and Effects of Direct Contact Between Coral and Macroalgae on Shallow Reefs Around O‘ahu, Hawai‘i.

    Get PDF
    M.S. Thesis. University of Hawaiʻi at Mānoa 2018

    Excess Post-Exercise Oxygen Consumption and Substrate Oxidation Following High-Intensity Interval Training: Effects of Recovery Manipulation

    Get PDF
    International Journal of Exercise Science 14(2): 1151-1165, 2021. The recovery manipulation during high-intensity interval training (HIIT) may have the potential to modulate the responses of post-exercise energy metabolism. The purpose of this study was to investigate how the type (i.e., passive and active) and duration (i.e., short and long) of the recovery between the intervals in HIIT affect the excess post-exercise oxygen consumption (EPOC) and oxidation of fats and carbohydrates during the post-exercise recovery. Eight physically active men performed a maximal incremental test, to determine the peak oxygen consumption (O2peak) and the first ventilatory threshold (VT), and four HIIT exercise sessions on a treadmill. The HIIT exercise sessions consisted of 5 intervals interspersed with 4 recovery periods; each interval was sustained until exhaustion, and the intensity was set at the O2peak velocity; recoveries were passive, active (VT velocity), short (2-min), or long (8-min). The HIIT exercise sessions were performed in a random and crossed manner. After the HIIT exercise sessions, EPOC and oxidation of fats and carbohydrates were measured during the 120-min of post-exercise recovery. There were no differences in the EPOC among the exercise sessions (p = 0.56). There were no differences among the exercise sessions in the amount of energy expended on the oxidation of fats (p = 0.78) and carbohydrates (p = 0.91) during the post-exercise recovery. The recovery manipulation during HIIT does not affect the EPOC and post-exercise fat and carbohydrate oxidation. One can choose the type and duration of recovery, knowing that the post-exercise substrate oxidation and EPOC responses will be preserved

    The Habitats and Biodiversity of Watamu Marine National Park: Evaluating Our Knowledge of One of East Africa's Oldest Marine Protected Areas

    Get PDF
    Watamu Marine National Park (WMNP) is one of the oldest no-take Marine Protected Areas (MPAs) in the world. Since its establishment in 1968, it has been the subject of a number of scientific studies as well as suffering from a range of modern threats to coastal marine habitats. The current state and conservation value of WMNP is documented in terms of habitat, biodiversity, and available scientific literature. There were 101 published references relating to WMNP found, which mostly focus on coral reef ecology, with less attention to other topics, such as biodiversity, socio-economics, or the ecology of non-coral reef habitats. The habitat map produced of WMNP is the first to show this level of detail and the only habitat map of a Kenyan MPA. Nine habitat categories were mapped; revealing that the most dominant habitat type is seagrass and the least is coral reef. Species lists were collected for fish, echinoderms, molluscs, crustaceans, corals, and seagrass, and species abundances were used to estimate total species richness, species diversity and sampling completeness. There were 18 species across all groups that fall into a category of conservation concern (other than Least Concern or Not Evaluated) on the IUCN Red List and 8 species found which are currently undescribed. The findings of this paper emphasise the importance of non-coral habitats in the WMNP, such as seagrass beds, and the need for more research into the ecology and conservation importance of these habitats. The information provided in this paper provides a comprehensive overview to any scientist or conservationist wanting to carry out further work in WMNP

    Hybrid materials based on polyethylene and MCM-41 microparticles functionalized with silanes: catalytic aspects of in situ polymerization, crystalline features and mechanical properties

    Get PDF
    New nanocomposites based on polyethylene have been prepared by in situ polymerization of ethylene in presence of mesoporous MCM-41. The polymerization reactions were performed using a zirconocene catalyst either under homogenous conditions or supported onto mesoporous MCM-41 particles, which are synthesized and decorated post-synthesis with two silanes before polymerization in order to promote an enhanced interfacial adhesion. The existence of polyethylene chains able to crystallize within the mesoporous channels in the resulting nanocomposites is figured out from the small endothermic process, located at around 80 C, on heating calorimetric experiments, in addition to the main melting endotherm. These results indicate that polyethylene macrochains can grow up during polymerization either outside or inside the MCM-41 channels, these keeping their regular hexagonal arrangements. Mechanical response is observed to be dependent on the content in mesoporous MCM-41 and on the crystalline features of polyethylene. Accordingly, stiffness increases and deformability decreases in the nanocomposites as much as MCM-41 content is enlarged and polyethylene amount within channels is raised. Ultimate mechanical performance improves with MCM-41 incorporation without varying the final processing temperature
    corecore