29 research outputs found

    IMPLEMENTATION AND OPTIMIZATION OF MULTI-RESONANCE AND PHASE CONTROL OF THE ELECTRICAL POWER TAKE-OFF ON A WEC ARRAY FOR IMPROVED PERFORMANCE

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    Many governments around the world are pledging to reduce their consumption of fossil fuels as they look to curb the amount of green house gasses they release into the atmosphere. These green house gasses are what scientists blame for global warming and the recent increase in extreme weather events. Producing electricity is one of the largest producers of these gasses but utilizing renewable sources can greatly decrease the amount of green house gasses produced. Common forms of renewable energies are wind and solar and both of these green energies have reached a state of maturation where they are economically viable to implement into full scale electrical grids. Wave energy is a less developed renewable energy and it has not yet reached the level of maturation where it can readily be implemented into the electric grid. Marine energy sources are a promising new source of energy as the majority of Americas population lives along the coast and the energy in water is more energy dense that of solar and wind powers. However, in order to implement full scale wave energy converters there needs to be additional development in wave forecasting, controls systems, power electronics, energy storage systems, grid integration, and the overall efficiency of the system. In this study wave energy converters are modelled from the excitation force of the water interacting with the buoy to the grid current being injected into the onshore electrical grid. The power and the efficiency of the system is analyzed from wave to wire and a control system is implemented to increase the efficiency of the system in a multi-frequency irregular wave environment. Additionally, the positioning of wave energy converters is an array is studied to determine the optimal placement of each buoy in order to maximize the energy delivered to the onshore electrical grid

    Enhancing Visualization Skills-Improving Options aNd Success (EnViSIONS) of Engineering and Technology Students

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    Spatial visualization skills are vital to many careers and in particular to STEM fields. Materials have been developed at Michigan Technological University and Penn State Erie, The Behrend College to assess and develop spatial skills.Β  The EnViSIONS (Enhancing Visualization Skills-Improving Options aNd Success) project is combining these materials and testing them with pre-college and college students atΒ  seven institutions: Michigan Tech, Penn State Behrend, Purdue University, University of Iowa, Virginia State University, Virginia Tech, and a β€œProject Lead the Way” course in south-central Arizona.Β  By removing a barrier to success for students with low visualization skills, particularly women, the project leaders hope to improve the retention of these students in STEM disciplines and to enhance their success. This paper will give a brief overview of the implementations at the university level and the findings

    Neural protection by naturopathic compoundsβ€”an example of tetramethylpyrazine from retina to brain

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    Given the advantages of being stable in the ambient environment, being permeable to the blood–brain and/or blood–eye barriers and being convenient for administration, naturopathic compounds have growingly become promising therapeutic candidates for neural protection. Extracted from one of the most common Chinese herbal medicines, tetramethylpyrazine (TMP), also designated as ligustrazine, has been suggested to be neuroprotective in the central nervous system as well as the peripheral nerve network. Although the detailed molecular mechanisms of its efficacy for neural protection are understood limitedly, accumulating evidence suggests that antioxidative stress, antagonism for calcium, and suppression of pro-inflammatory factors contribute significantly to its neuroprotection. In animal studies, systemic administration of TMP (subcutaneous injection, 50Β mg/kg) significantly blocked neuronal degeneration in hippocampus as well as the other vulnerable regions in brains of Sprague–Dawley rats following kainate-induced prolonged seizures. Results from us and others also demonstrated potent neuroprotective efficacy of TMP for retinal cells and robust benefits for brain in Alzheimer’s disease or other brain injury. These results suggest a promising prospect for TMP to be used as a treatment of specific neurodegenerative diseases. Given the assessment of the distribution, metabolism, excretion, and toxicity information that is already available on most neuroprotective naturopathic compounds such as TMP, it would not take much preclinical data to justify bringing such therapeutic compounds to clinical trials in humans

    Dutch Oncology COVID-19 consortium:Outcome of COVID-19 in patients with cancer in a nationwide cohort study

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    Aim of the study: Patients with cancer might have an increased risk for severe outcome of coronavirus disease 2019 (COVID-19). To identify risk factors associated with a worse outcome of COVID-19, a nationwide registry was developed for patients with cancer and COVID-19. Methods: This observational cohort study has been designed as a quality of care registry and is executed by the Dutch Oncology COVID-19 Consortium (DOCC), a nationwide collaboration of oncology physicians in the Netherlands. A questionnaire has been developed to collect pseudonymised patient data on patients' characteristics, cancer diagnosis and treatment. All patients with COVID-19 and a cancer diagnosis or treatment in the past 5 years are eligible. Results: Between March 27th and May 4th, 442 patients were registered. For this first analysis, 351 patients were included of whom 114 patients died. In multivariable analyses, age β‰₯65 years (p < 0.001), male gender (p = 0.035), prior or other malignancy (p = 0.045) and active diagnosis of haematological malignancy (p = 0.046) or lung cancer (p = 0.003) were independent risk factors for a fatal outcome of COVID-19. In a subgroup analysis of patients with active malignancy, the risk for a fatal outcome was mainly determined by tumour type (haematological malignancy or lung cancer) and age (β‰₯65 years). Conclusion: The findings in this registry indicate that patients with a haematological malignancy or lung cancer have an increased risk of a worse outcome of COVID-19. During the ongoing COVID-19 pandemic, these vulnerable patients should avoid exposure to severe acute respiratory syndrome coronavirus 2, whereas treatment adjustments and prioritising vaccination, when available, should also be considered

    Wave Energy Converter Direct Drive Power-Take-Off Power Electronic Design to Maximize Power Production

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    Wave Energy Converters (WECs) are a form of renewable energy that harvests energy from the waves in a large body of water. WEC systems contain both a mechanical and electrical power take-off (PTO). The systems\u27 mechanical PTO has been theoretically been optimized to absorb the maximum energy in the wave environment. Still, the electrical PTO of WECs has not yet been optimized to maximize power conversion. The optimal bus voltage and switching frequency of the inverter to maximize energy conversion remains largely unstudied. This study uses Typhoon HIL real-time software to model the mechanical and electrical systems of a WEC operating in an irregular wave environment. The switching frequency of the inverter and the bus voltage is varied to determine the optimal operating conditions for the electrical PTO of the WEC
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