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  1. Free, publicly-accessible full text available February 1, 2025
  2. null (Ed.)
  3. As part of the PI's outreach, a course-based undergraduate research experience engaged undergraduate women in research from examining the literature to identify a gap, formulating a research hypothesis, designing experiments to test the hypothesis, analyzing the data, writing and submitting an abstract and presenting the research to the scientific community. This project was as follows: in the US, 5 million people require blood transfusions each year. Although generally safe, there are drawbacks to blood transfusions including fever, acute immune or delayed hemolytic reactions, anaphylactic reactions, transfusion related acute lung injury, and bloodborne infections. Despite screening for diseases such as HIV and hepatitis, the risk of contraction is nonzero, and there are continually emerging bloodborne diseases such as Zika that are not yet screened for. Additionally, there are often blood bank shortages. These complications have driven decades of research into artificial blood, yet to date there are no blood substitutes clinically available. While hemoglobin based oxygen carriers have shown promise, they also show oxidative damage to tissues, particularly in cardiac and renal tissues. Both high and low oxygen PEGylated hemoglobin (Hb) have shown such oxidative stress. We hypothesized that this oxidative stress was due to direct delivery of the PEGylated Hb and conjugated PEGylated Hb onto PEG hydrogel microspheres. In this study, we probed the ability of the Hb microspheres to deliver oxygen. 
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  4. Abstract

    The neutron inelastic scattering of carbon-12, populating the Hoyle state, is a reaction of interest for the triple-alpha process. The inverse process (neutron upscattering) can enhance the Hoyle state’s decay rate to the bound states of12C, effectively increasing the overall triple-alpha reaction rate. The cross section of this reaction is impossible to measure experimentally but has been determined here at astrophysically-relevant energies using detailed balance. Using a highly-collimated monoenergetic beam, here we measure neutrons incident on the Texas Active Target Time Projection Chamber (TexAT TPC) filled with CO2gas, we measure the 3α-particles (arising from the decay of the Hoyle state following inelastic scattering) and a cross section is extracted. Here we show the neutron-upscattering enhancement is observed to be much smaller than previously expected. The importance of the neutron-upscattering enhancement may therefore not be significant aside from in very particular astrophysical sites (e.g. neutron star mergers).

     
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  5. A high frequency solid-state transformer (SST) proposed by FREEDM centre is an interesting alternative to conventional distribution transformer in microgrids as it supports additional functionalities such as active-reactive power flow control, fault current limitation and voltage regulation. This paper proposes a dynamic phasor based robust control of SST through the modular control of each stage. The control problem is formulated in frequency domain by representing the system states with time varying Fourier coefficients or dynamic phasors (DP). This formulation transforms the oscillating waveforms of ac circuits to constant or slowly varying variables, hence allow the use of PI controller to track the sinusoidal references. For rectifier and inverter stages of SST, dq transformation is applied on DP which facilitates the design of PI controller to smoothen out the ripples in the output voltage waveform. The controller gains are tuned to reject input and load disturbances and attenuate measurement noise using loop shaping and pole assignment technique. The robustness of the controller is assured analytically against parametric uncertainties using small gain theorem. Simulation results are provided to support the proposed control scheme. Hardwarein- Loop (HIL) simulation is carried out on critical stages using Opal-RT and dSPACE simulators to confirm the effectiveness of the proposed scheme. 
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  6. Free, publicly-accessible full text available January 1, 2025
  7. Free, publicly-accessible full text available December 1, 2024