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The Anchor, Volume 133.04: December 6, 2019
Get PDFThe Anchor began in 1887 and was first issued weekly in 1914. Covering national and campus news alike, Hope College’s student-run newspaper has grown over the years to encompass over two-dozen editors, reporters, and staff. For much of The Anchor\u27s history, the latest issue was distributed across campus each Wednesday throughout the academic school year (with few exceptions). In recent years The Anchor moved to monthly print issues and a more frequently updated website. The Anchor is now published in print twice per academic semester. Occasionally, the volume and/or issue numbering is irregular
Steadfast Standards or Fluctuating Fancies? Stability and Change in People’s Mate Criteria Over 27 Months
Get PDFAlthough research on mate preferences has been built on the assumption that the criteria people report at one point in time should predict their future partnering behavior, little is known about the temporal stability of people’s standards. Using survey data collected at four time points from 285 originally unmarried individuals, this study examined the rank-order, meanlevel, individual-level and ipsative stability of people’s mate criteria over 27 months. Overall, reported standards exhibited moderate to high baseline stability, with rank-order and ipsative estimates comparable to those reported for personality traits. At the same time, mean- and individual-level analyses revealed small, but significant, increases in participants’ reported criteria over the study, as well as significant variability in individual trajectories. Consistent with theory, the stability of individuals’ standards was moderated by several contextual factors, including age, changes in perceived mate value, and significant relationship events
Substrate-Dependent Photoconductivity Dynamics in a High-Efficiency Hybrid Perovskite Alloy
Get PDFFilms of (FA0.79MA0.16Cs0.05)0.97Pb(I0.84Br0.16)2.97 were grown over TiO2, SnO2, indium tin oxide (ITO), and NiO. Film conductivity was interrogated by measuring the in-phase and out-of-phase forces acting between the film and a charged microcantilever. We followed the films’ conductivity versus time, frequency, light intensity, and temperature (233−312 K). Perovskite conductivity was high and light-independent over ITO and NiO. Over TiO2 and SnO2, the conductivity was low in the dark,increased with light intensity, and persisted for 10’s of seconds after the light was removed. At an elevated temperature over TiO2, the rate of conductivity recovery in the dark showed an activated temperature dependence (Ea= 0.58eV). Surprisingly, the light-induced conductivity over TiO2 and SnO2 relaxed essentially instantaneously at a low temperature. We use a transmission-line model for mixed ionic−electronic conductors to show that the measurements presented are sensitive to the sum of electronic and ionic conductivities. We rationalize the seemingly incongruous observations using the idea that holes, introduced either by equilibration with the substrate or via optical irradiation, create iodide vacancies
Still Listening: New Sculptures by Todd Erickson
Get PDFA poster for the exhibition Still Listening: New Sculptures by Todd Erickson held May 31–August 3, 2019.https://digitalcommons.hope.edu/kam_poster/1007/thumbnail.jp
Effects of Columnar Defects on Microwave Nonlinearity in a Superconducting YBCO Resonator
Get PDFSecond and third order intermodulation (IM) signals in two superconducting microwave devices are measured before, during, and after the application of an approximately 50G static magnetic field. Each device under test is a roughly identical thin film YBa2Cu3O7−δ (YBCO) hairpin microwave resonator with a resonant frequency of approximately 840MHz. The first sample contains columnar defects orthogonal to the transmission line on its magnetic end. The second (control) sample contains no engineered defects. The defects were produced by irradiation of the sample with a beam of 250 MeV Au ions and serve as pinning centers for trapped magnetic flux. Flux pinning is a significant component of microwave nonlinearity in superconducting devices, which links pinning to the strength of produced IM. Second order IM in the control sample exhibits three distinct temperature dependent relaxation processes: an “ultrafast” exponential decay of unknown origin with a time constant on the order of 10-1 seconds, a fast exponential decay due to remanent demagnetization with a time constant on the order of 101 seconds, and a slow logarithmic relaxation due to Bean-Livingston surface barrier penetration with a duration on the order of 102 seconds. The irradiated sample does not exhibit the fast process. The influence of magnetic fluxons on second order IM is compared with the influence on third order IM, and the contributions of the columnar defects to each influence are examined
Determining the β Decay Strength Function of 91Rb
Get PDFThe r-process predicts the formation of elements heavier than iron and occurs in neutron star mergers and supernovae. The β decay strength function reveals nuclear structure properties necessary to improve r-process models. Measurements of the 91Rb strength function, a nucleus involved in the r process, were made at the National Superconducting Cyclotron Laboratory (NSCL) this past July (2018). The 91Rb were made with the A1900 fragment recoil separator, then stopped in a long gas cell, and finally implanted in a mylar tape. Spectra and multiplicity of γ rays from the daughter, 91Sr, coincident with β particles from the decay of implanted 91Rb give one the information needed to determine the β decay strength function. Electrons produced by the β decay were measured in a plastic detector constructed at Hope College and γ rays were detected in the Summing NaI (SuN) detector. Coincidences between electrons and γ rays were needed to identify the energy level in the 91Sr daughter nucleus to which the parent 91Rb decayed and to quantify the probability of that decay path. β particles from the decay of 91Rb are difficult to distinguish from background events due to the buildup of long-lived daughter particles that subsequently also β decay. A tape system extending into the beam pipe through SuN is needed to move radioactive daughter particles away from the detector. Thus, a conventional Si surface barrier β detector could not be employed because of minimal space inside the beam pipe. The needed β detector was fabricated to fit inside the small beam pipe and around the tape system. The 20 cm long, barrel-shaped detector was constructed out of scintillating plastic with wave-shifting fiber optic cables on the exterior leading to photomultiplier tubes outside the SuN detector. Preliminary results are shown
News from Hope College, Volume 51.1: Summer, 2019
Get PDFhttps://digitalcommons.hope.edu/news_from_hope_college/1251/thumbnail.jp
Testing the Impact of Prebiotics on Anxiety-like Behaviors in Aged Male Rats
Get PDFThe composition of gut microbiota has direct impacts on neural structure, neurochemistry, and behavior. Specifically, the gut microbiota has been shown to modulate anxiety-like behaviors. In addition, administering prebiotics, compounds that promote the growth of commensal bacteria, has been demonstrated to reduce anxiety and anxiety-related behaviors. However, this effect has yet to be tested in older animals despite anxiety being implicated as a most common disorder in adult populations. Therefore, this study seeks to fill this knowledge gap by investigating the link between prebiotic interventions and anxiety-like behaviors in aged populations. It was hypothesized that older rats treated with the prebiotic fructooligosaccharide (FOS) would display an increase in exploratory behaviors, correlating to a decrease in anxiety, compared to the controls. Behavioral assays such as the open field test (OFT), elevated plus maze (EPM), and a social anxiety (SA) test were conducted. Results demonstrate moderate evidence that rats administered FOS had increased exploration in the center zone of the OFT. This finding suggests that FOS helps to modulate behavior in aged animals. With moderate evidence for increased exploration as evidence for decreased anxiety in FOS treated animals, this study provides a platform for further investigation of the role of modulating gut microbiota in older animals. Investigating the effects of senescence versus prebiotic treatment of the rats in this cohort was dampened by the limitations of the precedent of behavioral assays utilized on smaller, younger animals. As a result, this study calls for a widening of behavioral assay parameters to allow for effective data collection in an aging population
Deities and Devotion in Mongolian Buddhist Art
Get PDFDesign by Tom Wagner. Produced by Storming the Castle Pictures (StCP) as a catalog for the Kruizenga Art Museum exhibition “Deities and Devotion in Mongolian Buddhist Art,” August 30 – December 14, 2019.https://digitalcommons.hope.edu/kam_catalogs/1002/thumbnail.jp