The Mass-Radius Relation Of Young Stars. I. Usco 5, An M4.5 Eclipsing Binary In Upper Scorpius Observed By K2

We present the discovery that UScoCTIO 5, a known spectroscopic binary in the Upper Scorpius star-forming region (P = 34 days, M-tot sin(i) = 0.64M(circle dot)), is an eclipsing system with both primary and secondary eclipses apparent in K2 light curves obtained during Campaign 2. We have simultaneously fit the eclipse profiles from the K2 light curves and the existing RV data to demonstrate that UScoCTIO 5 consists of a pair of nearly identical M4.5 stars with M-A = 0.329 +/- 0.002 M-circle dot, R-A = 0.834 +/- 0.006 R-circle dot, M-B = 0.317 +/- 0.002 M-circle dot, and R-B = 0.810 +/- 0.006 R-circle dot. The radii are broadly consistent with pre-main-sequence ages predicted by stellar evolutionary models, but none agree to within the uncertainties. All models predict systematically incorrect masses at the 25%-50% level for the HR diagram position of these mid-M dwarfs, suggesting significant modifications to mass-dependent outcomes of star and planet formation. The form of the discrepancy for most model sets is not that they predict luminosities that are too low, but rather that they predict temperatures that are too high, suggesting that the models do not fully encompass the physics of energy transport (via convection and/or missing opacities) and/or a miscalibration of the SpT-T-eff scale. The simplest modification to the models (changing T-eff to match observations) would yield an older age for this system, in line with the recently proposed older age of Upper Scorpius (tau similar to 11 Myr).NASA Science Mission directorateW. M. Keck FoundationAstronom

The Bell Academy: A Bridge Semester Where Engineering Students Transform Into Student Engineers Who Thrive In Industry Placements

Iron Range Engineering is an innovative learning program using project-based and work-based pedagogies. The Bell Academy (BA) is a semester-long bridge experience between the first two years of STEM foundation and the final two years spent in full-time industry co-op placements. The curriculum within the academy is delivered within three domains: technical, design, and professional. The transformation to thriving as a student engineer in an industry placement is intentionally embedded in each stage of the program as students develop higher levels of self-awareness, professional responsibility, and self-directedness. Students not only gain technical engineering knowledge, but also apply that knowledge within team-based, ill-structured design projects, acting as engineering consultants to industry clients. Technical learning is delivered in one-credit modules, which supports both the development of the individual as a student engineer and the execution of the project. Professional competencies are learned in-situ as teams encounter natural struggles. Development is supported through workshops, which cover topics such as conflict management, leadership, technical writing, data science, public speaking, inclusive action, etc. Through iterative assignments and practice, such as resume development, negotiation, and interviewing, students develop a skills portfolio to identify and acquire a position to begin and maintain their career. Through more than a decade of implementation, several unique learning strategies have been developed and refined. The paper will briefly describe the model used and provide the strategies as potential tools for adaptation and implementation in engineering programs worldwide

Comparison of Estimated-1RM and 225-lb (102-kg) bench press performance between starters and non-starters among a NCAA Division I college football team

The estimated one-repetition maximum (1RM) bench press and NFL-225 (225-lb or 102-kg) repetition test are commonly used to assess upper-body muscular strength and endurance among football players. However, little research has been focused on the relationship of these tests to playing status. Therefore, the purpose of this study was to determine if significant relationships exist between these tests and playing status in Division I football athletes. Archival data from 31 NCAA Division I football players (age: 20.1±1.4 yrs., height: 188.07 ± 5.93 cm, body mass: 112.4 ± 19.5 kg) on the 1RM Bench press test, NFL-225 test and playing status were utilized for this analysis. A one-way ANOVA was used to detect any differences in 1RM and NFL-225 performance between skill groups: big (linemen), medium (linebackers, quarterbacks, tight ends) and small (receivers, backs, and corners) (p < 0.05). Playing status (starters vs. non-starters) were compared within position groups. A point bi-serial correlation was then utilized to examine the relationship in test performance between groups, as well as between starters and non-starters. Significant differences were discovered in NFL-225 test performance between big and small skill groups. Moderate-to-strong relationships between playing status and performance on the 1RM bench press (r = .660) and the NFL-225 test (r = .685) for the big skills group. The results of this study suggest that playing status and upper-body strength and endurance are strongly related for the big skills position group

A Comparison of Lower Body Power Characteristics Between Collegiate Athletes from Different Competition Levels.

International Journal of Exercise Science 13(6): 470-479, 2020. The counter-movement jump (CMJ) is frequently utilized by strength and conditioning professionals working with athletes, given its relationship to a multitude of performance variables associated with success in sports. PURPOSE: To examine characteristics of CMJ performance between NAIA and NCAA Division I male and female athletes. METHODS: Archival data for 275 student athletes from two NCAA Division 1 universities (NCAA DI; males = 84, females = 74) and one NAIA university (NAIA; males = 66, females = 51) were utilized for this analysis. The CMJ was performed utilizing a dual single axis (Pasco PS 2141 plates, sampling rate 1000hz unfiltered) force platform system. A 2 x 2 multivariate analysis of variance (MANOVA) was used to determine whether significant differences in the three dependent variables of VJ height (cm), concentric RPD-100ms, and peak power existed between athletes at different playing levels. RESULTS: A MANOVA revealed significant differences based on sex and competition level in the dependent variables measured (Wilk’s Lambda = 0.908, F(3,259) = 8.732, p \u3c .001, partial η2= .092). DISCUSSION: The findings of this study revealed that females at the Division I level achieved significantly greater jump heights, peak power and concentric RPD-100ms compared to females at the NAIA level. Division I males displayed significantly higher peak power than their NAIA counterparts

Building Partnerships to Bridge the Transfer Gap and Increase Student Success

Transfer partnerships continue to be one of the most critical elements of student success. The purpose of this paper is to highlight the bridges and transfer gaps from a two-year college to a university and respect the value of the support and knowledge students are currently receiving at their community college, from the context of the practices and experiences of Iron Range Engineering - Bell. The transfer process, afterall, can be daunting to some students who plan to transition from a community college to a university to finish a Bachelor’s degree. Iron Range Engineering - Bell is a unique, co-op based upper division program that strives to facilitate a positive experience for students undergoing this transition. The transfer process can be equally as challenging for community college faculty and staff who may feel the need for additional support in their roles. They play a large role in the transfer process and oftentimes go above and beyond their responsibilities to meet with students to determine their pathway forward after spending time at their respective community colleges. This paper proposes unique ways that university faculty and staff can support two-year colleges during the student transfer process, making these partnerships a more positive experience while achieving a shared goal of supporting student success. Some of the unique ideas include encouraging back transfer to fulfill Associates degree requirements, shared teaching methods, offering bridge courses without two-year colleges changing their curriculum, allowing flexibility for the timing of transfer to meet the needs of students, and active university participation in advising and supporting students. In the end, students who are prepared and have more context tend to perform better and absorb more information sooner in the experience-based learning model that is Iron Range Engineering - Bell

THE MASS-RADIUS RELATION OF YOUNG STARS. I. USCO 5, AN M4.5 ECLIPSING BINARY IN UPPER SCORPIUS OBSERVED BY K2

We present the discovery that UScoCTIO 5, a known spectroscopic binary in the Upper Scorpius star-forming region (P = 34 days, Mtot sin(i) = 0.64 M⊙), is an eclipsing system with both primary and secondary eclipses apparent in K2 light curves obtained during Campaign 2. We have simultaneously fit the eclipse profiles from the K2 light curves and the existing RV data to demonstrate that UScoCTIO 5 consists of a pair of nearly identical M4.5 stars with MA = 0.329 ± 0.002 M⊙, RA = 0.834 ± 0.006 R⊙, MB = 0.317 ± 0.002 M⊙, and RB = 0.810 ± 0.006 R⊙. The radii are broadly consistent with pre-main-sequence ages predicted by stellar evolutionary models, but none agree to within the uncertainties. All models predict systematically incorrect masses at the 25%-50% level for the HR diagram position of these mid-M dwarfs, suggesting significant modifications to mass-dependent outcomes of star and planet formation. The form of the discrepancy for most model sets is not that they predict luminosities that are too low, but rather that they predict temperatures that are too high, suggesting that the models do not fully encompass the physics of energy transport (via convection and/or missing opacities) and/or a miscalibration of the SpT-Teff scale. The simplest modification to the models (changing Teff to match observations) would yield an older age for this system, in line with the recently proposed older age of Upper Scorpius (τ ∼ 11 Myr)

The mass-radius relation of young stars from K2

Evolutionary models of pre-main sequence stars remain largely uncalibrated, especially for masses below that of the Sun, and dynamical masses and radii pose valuable tests of these theoretical models. Stellar mass dependent features of star formation (such as disk evolution, planet formation, and even the IMF) are fundamentally tied to these models, which implies a systematic uncertainty that can only be improved with precise measurements of calibrator stars. We will describe the discovery and characterization of ten eclipsing binary systems in the Upper Scorpius star-forming region from K2 Campaign 2 data, spanning from B stars to the substellar boundary. We have obtained complementary RV curves, spectral classifications, and high-resolution imaging for these targets; the combination of these data yield high-precision masses and radii for the binary components, and hence a dense sampling of the (nominally coeval) mass-radius relation of 10 Myr old stars. We already reported initial results from this program for the young M4.5 eclipsing binary UScoCTIO 5 (Kraus et al. 2015), demonstrating that theoretically predicted masses are discrepant by ~50% for low-mass stars. K2's unique radius measurements allow us to isolate the source of the discrepancy: models of young stars do not predict luminosities that are too low, as is commonly thought, but rather temperatures that are too warm.http://adsabs.harvard.edu/abs/2016AAS...22723612KPublished versio

Validating First-Principles Phonon Lifetimes via Inelastic Neutron Scattering

Phonon lifetimes are a key component of quasiparticle theories of transport, yet first-principles lifetimes are rarely directly compared to inelastic neutron scattering (INS) results. Existing comparisons show discrepancies even at temperatures where perturbation theory is expected to be reliable. In this work, we demonstrate that the reciprocal space voxel ($q$-voxel), which is the finite region in reciprocal space required in INS data analysis, must be explicitly accounted for within theory in order to draw a meaningful comparison. We demonstrate accurate predictions of peak widths of the scattering function when accounting for the $q$-voxel in CaF$_2$ and ThO$_2$. Passing this test implies high fidelity of the phonon interactions and the approximations used to compute the Green's function, serving as critical benchmark of theory, and indicating that other material properties should be accurately predicted; which we demonstrate for thermal conductivity

Lessons Learned from Preparing OSIRIS-REx Spectral Analog Samples for Bennu

NASA\u27s OSIRIS-REx sample return mission launched on September 8th, 2016 to rendezvous with B-type hide asteroid (101955) Bennu in 2018. Type C and B asteroids have been linked to carbonaceous chondrites because of their similar visible - to - near infrared (VIS-NIR) spectral properties [e.g., 1,2]. The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the Thermal Emission Spectrometer (OTES) will make spectroscopic observations of Bennu during the encounter. Constraining the presence or absence of hydrous minerals (e.g., Ca-carbonate, phyllosilicates) and organic molecules will be key to characterizing Bennu [3] prior to sample site selection. The goal of this study was to develop a suite of analog and meteorite samples and obtain their spectral properties over the wavelength ranges of OVIRS (0.4- 4.3 micrometer) and OTES (5.0-50 micrometer). These spectral data were used to validate the mission science-data processing system. We discuss the reasoning behind the study and share lessons learne