Time Resolution and Linearity Measurements for a Scintillating Fiber Detector Instrumented with VLPC's

The time resolution for a charged particle detection is reported for a typical scintillating fiber detector instrumented with Rockwell HISTE-IV Visible Light Photon Counters. The resolution measurements are shown to agree with a simple Monte Carlo model, and the model is used to make recomendations for improved performance. In addition, the gain linearity of a sample of VLPC devices was measured. The gain is shown to be linear for incident light intensities which produce up to approximately 600 photoelectrons per event.Comment: 18 pages, 14 figures; Submitted to Nucl. Instr & Meth. in Phys. Res. A; Please direct correspondence to [email protected]

NLTE analysis of Sr lines in spectra of late-type stars with new R-matrix atomic data

We investigate statistical equilibrium of neutral and singly-ionized strontium in late-type stellar atmospheres. Particular attention is given to the completeness of the model atom, which includes new energy levels, transition probabilities, photoionization and electron-impact excitation cross-sections computed with the R-matrix method. The NLTE model is applied to the analysis of Sr I and Sr II lines in the spectra of the Sun, Procyon, Arcturus, and HD 122563, showing a significant improvement in the ionization balance compared to LTE line formation calculations, which predict abundance discrepancies of up to 0.5 dex. The solar Sr abundance is log A = 2.93 \pm 0.04 dex, in agreement with the meteorites. A grid of NLTE abundance corrections for Sr I and Sr II lines covering a large range of stellar parameters is presented.Comment: 11 pages, 7 figures, accepted for publication in Astronomy & Astrophysic

Non-local thermodynamic equilibrium stellar spectroscopy with 1D and 3D models - II. Chemical properties of the Galactic metal-poor disc and the halo

From exploratory studies and theoretical expectations it is known that simplifying approximations in spectroscopic analysis (LTE, 1D) lead to systematic biases of stellar parameters and abundances. These biases depend strongly on surface gravity, temperature, and, in particular, for LTE vs. non-LTE (NLTE) on metallicity of the stars. Here we analyse the [Mg/Fe] and [Fe/H] plane of a sample of 326 stars, comparing LTE and NLTE results obtained using 1D hydrostatic models and averaged models. We show that compared to the NLTE benchmark, all other three methods display increasing biases towards lower metallicities, resulting in false trends of [Mg/Fe] against [Fe/H], which have profound implications for interpretations by chemical evolution models. In our best NLTE model, the halo and disc stars show a clearer behaviour in the [Mg/Fe] - [Fe/H] plane, from the knee in abundance space down to the lowest metallicities. Our sample has a large fraction of thick disc stars and this population extends down to at least [Fe/H] ~ -1.6 dex, further than previously proven. The thick disc stars display a constant [Mg/Fe] ~ 0.3 dex, with a small intrinsic dispersion in [Mg/Fe] that suggests that a fast SN Ia channel is not relevant for the disc formation. The halo stars reach higher [Mg/Fe] ratios and display a net trend of [Mg/Fe] at low metallicities, paired with a large dispersion in [Mg/Fe]. These indicate the diverse origin of halo stars from accreted low-mass systems to stochastic/inhomogeneous chemical evolution in the Galactic halo.Comment: 15 pages, accepted for publication in Ap

Summary Report of the Topical Group on Physics Education, Community Engagement Frontier (CEF4/CommF4) Snowmass 2021

An essential companion to the development and advancement of the field of Particle Physics is a strong program in physics education at all levels, that can attract entry level students across the full demographic spectrum and provide them with the education, training and skills needed to advance to successful careers in Science, Technology, Engineering and Mathematics (STEM) and other fields. This report summarizes the work of several investigative teams that have reviewed and assessed current opportunities in physics education across K-12, undergraduate, graduate and postdoctoral domains, including national and international linkages. From these assessments, recommendations have been put forward aimed to innovate educationally in strategic ways to strengthen ties between the research community and teachers, between the academic community and the private sector, and through both domestic and international connections.Comment: 9 pages, 1 figur

Evaluation of the Concrete Core Conditioning Performance for Flexible Building Zone Configurations

Today’s building design objectives are more and more determined by sustainability, flexibility and the quality of the indoor environment. A potential concept is the application of concrete core conditioning to reduce the energy consumption and increase the thermal comfort. However, the performance of concrete core conditioning in relation to the changing utilization of a building (flexibility) is unknown. This paper gives a developed multi-zone dynamic simulation model of a concrete core conditioning system. This model has been applied for the performance of case studies with large sets of building zone configurations to clarify the consequences of the application of concrete core conditioning for the flexibility of a building with regard to the achievable indoor thermal comfort. It is concluded that the self controllability of concrete core conditioning can accommodate limited flexibility changes without loss of thermal comfort. The combination of concrete core conditioning with an additional local installation component for both heating and cooling makes the concept suitable for flexible building zone configurations. However, the combination of concrete core conditioning and an additional local component should be well-considered, in terms of design and control strategies, in order to achieve the desired energy efficiency

Old puzzle, new insights: a lithium rich giant quietly burning helium in its core

About 1% of giant stars have been shown to have large surface Li abundances, which is unexpected according to standard stellar evolution models. Several scenarios for lithium production have been proposed, but it is still unclear why these Li-rich giants exist. A missing piece in this puzzle is the knowledge of the exact stage of evolution of these stars. Using low-and-high-resolution spectroscopic observations, we have undertaken a survey of lithium-rich giants in the Kepler field. In this letter, we report the finding of the first confirmed Li-rich core-helium-burning giant, as revealed by asteroseismic analysis. The evolutionary timescales constrained by its mass suggest that Li-production most likely took place through non-canonical mixing at the RGB-tip, possibly during the helium flash.Comment: 16 pages, 4 figures, 1 table, accepted in ApJ Letter

Olympism as education: Analysing the learning experiences of elite athletes

Olympic athletes are potentially the most visible exponents of Olympic values. How athletes learn values, however, has not captured the attention of those responsible for Olympic documentation or pedagogues. This paper examines how aspects of Olympism became relevant for three former Olympians during their athletic careers. Interview material suggested that: (1) inconsistencies within official expressions of Olympism mirror tensions in athletic experiences; (2) some claims concerning sport made in the Olympic Charter are simplistic and translate poorly to Olympic experiences that are multidimensional and complex; and (3) universal ethical principles have limited influence on how athletes conduct themselves. The results imply that pedagogues working with elite athletes should make discursive discontinuities in sport explicit, reflect on traditional views of sport education while acknowledging implicit learning, and approach questions of ethics from a specific and practice-oriented standpoint rather than a universal and principle-based one

Athlete learning in Olympic sport

High-performance sport impacts athletes beyond the physical. Coaches and coaching practice are particularly influential in shaping this learning and development. This article examines the learning identified through an inductive content analysis of eight former Olympic athletes’ career narratives. Three phases of learning could be identified across the cohort: ‘Growing into high-performance sport’, ‘Making sense of high-performance sport’, and ‘(Re)shaping high-performance sport’. A cultural perspective of learning, in particular the metaphor of ‘becoming’, is employed to interpret the Olympians’ learning experiences. The findings of this research indicate that athlete learning is bound by particular high-performance sporting contexts and career phases, yet impacted by the athletes’ individual backgrounds and dispositions. Further, data indicate that athletes’ personal development reflexively intertwines with athletic performance and performance enhancement. Implications for coaches are to: (1) involve athletes in co-constructing their sporting cultures and training contexts; and (2) provide possibilities and support for athletes to develop personally

Slam Poetry: An Online Intervention for Treating Depression

Given that depression is the “leading cause of disability worldwide,” and that less than 50% of people suffering from depression receive treatment, this study aims to provide support for a globally accessible depression treatment (WHO, 2012). The study conducted implemented an internet-based treatment for depression in which users were provided an opportunity to watch slam poetry videos related to mental health issues and write free responses regarding the content of the videos and their subjective experience of depression. Numerous studies provide support for the effectiveness of expressive writing, online mental health interventions, and slam poetry in particular for reducing symptoms of depression. Data collection occurred in two forms. Survey data about participants’ moods was collected before and after watching the slam poetry videos and again after providing the written response. Additionally, the researchers performed text analysis using Linguistic Inquiry and Word Count (LIWC) on the written responses to track use of negative and positive emotion words, among others, which have been shown to indicate levels of depression. The data showed an overall increase in positive emotion words and decrease in negative emotion words in participant surveys after each stage of the study. In addition, the text analyses indicated a greater percentage of positive over negative words used by participants in their free-responses. These data support the hypothesis that engaging in slam poetry online can be a globally accessible and effective tool for improving mood

A conditional glutamatergic synaptic vesicle marker for Drosophila

Glutamate is a principal neurotransmitter used extensively by the nervous systems of all vertebrate and invertebrate animals. It is primarily an excitatory neurotransmitter that has been implicated in nervous system development, as well as a myriad of brain functions from the simple transmission of information between neurons to more complex aspects of nervous system function including synaptic plasticity, learning, and memory. Identification of glutamatergic neurons and their sites of glutamate release are thus essential for understanding the mechanisms of neural circuit function and how information is processed to generate behavior. Here, we describe and characterize smFLAG-vGlut, a conditional marker of glutamatergic synaptic vesicles for the Drosophila model system. smFLAG-vGlut is validated for functionality, conditional expression, and specificity for glutamatergic neurons and synaptic vesicles. The utility of smFLAG-vGlut is demonstrated by glutamatergic neurotransmitter phenotyping of 26 different central complex neuron types of which nine were established to be glutamatergic. This illumination of glutamate neurotransmitter usage will enhance the modeling of central complex neural circuitry and thereby our understanding of information processing by this region of the fly brain. The use of smFLAG for glutamatergic neurotransmitter phenotyping and identification of glutamate release sites can be extended to any Drosophila neuron(s) represented by a binary transcription system driver