A Miniaturized Multi Sensor Array for Balloon-Borne Air Measurements, Phase I

Weber State University’s High-Altitude Ballooning team, HARBOR, has seen an opportunity for cooperative research among the many individual balloon teams based in North America. The Great American Solar Eclipse brought these teams into the spotlight as dozens of ballooning groups worked together to image the eclipse. Leveraging this collection of balloon teams to create a large-scale data set could make some valuable discoveries and give us a better understanding of the atmospheric dynamics that take place in the stratosphere. Our team has decided to facilitate the creation of such a data set by designing an atmospheric data collection tool, the mini-Multi Sensor Array, that can be flown by teams all over the nation, and potentially the world. Our goal is to create an inexpensive, lightweight, easy to assemble device which will measure gas concentrations, particulate matter, atmospheric turbulence, and meteorological parameters such as temperature, pressure, and humidity. We will also add features such as long distance telemetry, which will facilitate recovery of these payloads. Having a redundant, lightweight tracking device will increase the number of flight teams that are making a regular effort to fly our mini-MSA with their payload

Harnessing spontaneous Brillouin scattering for nonequilibrium phonon spectroscopy

Phonon spectroscopy allows access to phonon populations of individual acoustic modes within a material, thereby offering information about the material’s optical and mechanical properties. Selectivemanipulation of phonon populations has been demonstrated using spontaneous backward Brillouin scattering in photonic systems [29, 43, 20]. In this work we demonstrate phonon spectroscopy in liquid core optical fibers using spontaneous backward Brillouin scattering and introduce a novel method for isolating and measuring thermal phonon populations. This inelastic scattering process paired with heterodyne spectroscopy offers an elegant solution for measuring Stokes and anti-Stokes phonon mode populations where one backscattered photon corresponds to one phase-matched phonon. An optical field is injected into a liquid core optical fiber and interacts with the material’s spontaneously generated vibrational modes. In the case of optical scattering from a forward propagating wave, the backscattered Stokes light is red-shifted in frequency where energy is deposited from the optical field into the phase-matched acoustic mode [32, 34, 2]. Similarly, backscattered anti-Stokes light is blue-shifted when the optical field interacts with a counter-propagating traveling acoustic wave. Through heterodyne detection, the backscattered signal combined with a known local oscillator produces a beatnote frequency directly corresponding to the phase-matched phonon population distribution. Additional damping of the anti-Stokes acoustic mode scales with optical power allowing for a form of laser modal cooling for the backward traveling acoustic phonons [29]. We introduce a method including two orthogonally polarized optical fields to isolate thermal phonon contributions intrinsic to the material from those driven by the optical field for the first time. In this way, we determine the thermal phonon occupation for the Stokes and anti-Stokes sidebands and demonstrate attenuation of the anti-Stokes phonon population

Means and standard deviations for itch VAS scores in the learning phase for the different groups.

<p>Means (M) and standard deviations (SD) of the visual analogue scale (VAS) scores for itch in the verbal suggestion group (<i>n = 23</i>), conditioning group (<i>n = 24</i>), conditioning with verbal suggestion group (<i>n = 23</i>) and control group (<i>n = 25</i>) in the learning phase.</p

Means and standard deviations for itch VAS scores in the testing phase for the different groups.

<p>Means (M) and standard deviations (SD) of the visual analogue scale (VAS) scores for itch in the verbal suggestion group (<i>n = 23</i>), conditioning group (<i>n = 24</i>), conditioning with verbal suggestion group (<i>n = 23</i>), and control group (<i>n = 25</i>) in the testing phase.</p

Means and standard error of the mean of the visual analogue scale (VAS) itch scores for the placebo effect (change VAS score between the green and yellow cues) of the four groups in the testing phase.

<p>The asterisks show the level of significance related to the post hoc Dunnett comparison of the placebo effect between the experimental groups and the control group (**<i>p</i><0.01; *<i>p</i><0.05; <i>t</i> = <i>p</i><0.10).</p

Flow diagram showing the experimental procedures of the study in chronological order.

<p>Flow diagram showing the experimental procedures of the study in chronological order.</p

Means and standard error of the mean of the visual analogue scale (VAS) itch scores for the nocebo effect (change VAS score between the red and yellow cues) of the four groups in the testing phase.

<p>The asterisks show the level of significance related to the post hoc Dunnett comparison of the nocebo effect between the experimental groups and the control group (**<i>p</i><0.01; *<i>p</i><0.05; <i>t</i> = <i>p</i><0.10).</p

Experimental design.

<p>Subjects were randomly assigned to one of four groups: verbal suggestion; conditioning; verbal suggestion with conditioning; and control. In the learning phase verbal suggestion and conditioning procedures depended on the experimental group. In the testing phase the verbal suggestion was in correspondence with the verbal suggestion applied in the learning phase, while all participants received itch stimuli of a medium intensity.</p