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  1. ; ; ; ; ; ; ; ( , Applied physics letters)
    Interdigitated transducer devices provide an advantageous platform to study stress-enhanced interfacial phenomena at elevated temperatures but require a thorough understanding of temperature-dependent material properties. In this study, the temperature dependence of the piezoelectric coefficient for gallium arsenide is determined from 22 ℃ to 177 ℃. Experimental scattering parameter responses are measured for a two-port surface acoustic wave resonator at different temperatures and piezoelectric coefficient values are extracted using a frequency-domain finite element method simulation. Device measurements are taken using an interdigitated transducer fabricated on semi-insulating GaAs(100), oriented in the 〈110〉 direction and device resonant frequencies are shown to decrease withmore »increasing temperature. The experimental scattering response is used to reconcile the simulated scattering response and extract the 𝑒14 piezoelectric coefficient, which is shown to increase linearly with temperature. Using the extracted 𝑒14, surface acoustic wave analysis is completed to study the magnitude of bulk stress values and surface displacement over the experimental temperature range produced by a standing surface acoustic wave field. Surface displacement measurements are taken at room temperature using contact-mode AFM, which corroborate the simulation predictions. The modeling results demonstrate an interdigitated transducers potential as an experimental stage to study surface and bulk stress effects on temperature-sensitive phenomena.« less
    Accepted Manuscript Full Text Available
  2. ; ; ; ; ; ; ; ; ( , Applied physics letters)
    Interdigitated transducer devices provide an advantageous platform to study stress-enhanced interfacial phenomena at elevated temperatures but require a thorough understanding of temperature-dependent material properties. In this study, the temperature dependence of the piezoelectric coefficient for gallium arsenide is determined from 22 ℃ to 177 ℃. Experimental scattering parameter responses are measured for a two-port surface acoustic wave resonator at different temperatures and piezoelectric coefficient values are extracted using a frequency-domain finite element method simulation. Device measurements are taken using an interdigitated transducer fabricated on semi-insulating GaAs(100), oriented in the 〈110〉 direction and device resonant frequencies are shown to decrease withmore »increasing temperature. The experimental scattering response is used to reconcile the simulated scattering response and extract the e_14 piezoelectric coefficient, which is shown to increase linearly with temperature. Using the extracted e_14, surface acoustic wave analysis is completed to study the magnitude of bulk stress values and surface displacement over the experimental temperature range produced by a standing surface acoustic wave field. Surface displacement measurements are taken at room temperature using contact-mode AFM, which corroborate the simulation predictions. The modeling results demonstrate an interdigitated transducers potential as an experimental stage to study surface and bulk stress effects on temperature-sensitive phenomena.« less
    Accepted Manuscript Full Text Available
  3. ; ; ; ; ( , Trends in Ecology & Evolution)
    Full Text Available 
  4. ; ; ; ; ( , Frontiers in Robotics and AI)
    Full Text Available 
  5. ; ; ; ; ; ; ; ; ; ; et al ( , Nature Medicine)
    Full Text Available 
  6. ; ; ; ; ; ; ; ; ; ; et al ( , Journal of Instrumentation)
    Abstract The Surface Enhancement of the IceTop air-shower array will include the addition of radio antennas and scintillator panels, co-located with the existing ice-Cherenkov tanks and covering an area of about 1 km 2 . Together, these will increase the sensitivity of the IceCube Neutrino Observatory to the electromagnetic and muonic components of cosmic-ray-induced air showers at the South Pole. The inclusion of the radio technique necessitates an expanded set of simulation and analysis tools to explore the radio-frequency emission from air showers in the 70 MHz to 350 MHz band. In this paper we describe the software modules thatmore »have been developed to work with time- and frequency-domain information within IceCube's existing software framework, IceTray, which is used by the entire IceCube collaboration. The software includes a method by which air-shower simulation, generated using CoREAS, can be reused via waveform interpolation, thus overcoming a significant computational hurdle in the field.« less
    Free, publicly-accessible full text available June 1, 2023
  7. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review Letters)
    Free, publicly-accessible full text available June 1, 2023
  8. ; ; ; ; ; ; ; ; ; ; et al ( , The Astrophysical Journal)
    Abstract We present a measurement of the high-energy astrophysical muon–neutrino flux with the IceCube Neutrino Observatory. The measurement uses a high-purity selection of 650k neutrino-induced muon tracks from the northern celestial hemisphere, corresponding to 9.5 yr of experimental data. With respect to previous publications, the measurement is improved by the increased size of the event sample and the extended model testing beyond simple power-law hypotheses. An updated treatment of systematic uncertainties and atmospheric background fluxes has been implemented based on recent models. The best-fit single power-law parameterization for the astrophysical energy spectrum results in a normalization of ϕ @ 100more »TeV ν μ + ν ¯ μ = 1.44 − 0.26 + 0.25 × 10 − 18 GeV − 1 cm − 2 s − 1 sr − 1 and a spectral index γ SPL = 2.37 − 0.09 + 0.09 , constrained in the energy range from 15 TeV to 5 PeV. The model tests include a single power law with a spectral cutoff at high energies, a log-parabola model, several source-class-specific flux predictions from the literature, and a model-independent spectral unfolding. The data are consistent with a single power-law hypothesis, however, spectra with softening above one PeV are statistically more favorable at a two-sigma level.« less
    Free, publicly-accessible full text available March 1, 2023
  9. ; ; ; ; ; ; ; ; ; ; et al ( , Physical Review D)
    Free, publicly-accessible full text available March 1, 2023
  10. ; ; ; ; ; ; ; ; ; ; et al ( , The Astrophysical Journal)
    Abstract Ultraluminous infrared galaxies (ULIRGs) have infrared luminosities L IR ≥ 10 12 L ⊙ , making them the most luminous objects in the infrared sky. These dusty objects are generally powered by starbursts with star formation rates that exceed 100 M ⊙ yr −1 , possibly combined with a contribution from an active galactic nucleus. Such environments make ULIRGs plausible sources of astrophysical high-energy neutrinos, which can be observed by the IceCube Neutrino Observatory at the South Pole. We present a stacking search for high-energy neutrinos from a representative sample of 75 ULIRGs with redshift z ≤ 0.13 usingmore »7.5 yr of IceCube data. The results are consistent with a background-only observation, yielding upper limits on the neutrino flux from these 75 ULIRGs. For an unbroken E −2.5 power-law spectrum, we report an upper limit on the stacked flux Φ ν μ + ν ¯ μ 90 % = 3.24 × 10 − 14 TeV − 1 cm − 2 s − 1 ( E / 10 TeV ) − 2.5 at 90% confidence level. In addition, we constrain the contribution of the ULIRG source population to the observed diffuse astrophysical neutrino flux as well as model predictions.« less
    Free, publicly-accessible full text available February 1, 2023