204 research outputs found
Spring Demonstration Device
ME450 Capstone Design and Manufacturing Experience: Winter 2015At the University of Michigan, Mechanical Engineering students must complete an introductory design and manufacturing course, Mechanical Engineering 250. This course teaches fundamental principles such as gear trains, bearings, bolts, and springs. The instructor of this course, Michael Umbriac, approached our team in hopes of creating a spring demonstration device. This device should use compression springs of differing wire diameter, outside diameter, and free length to simultaneously launch 3 identical balls vertically into the air.http://deepblue.lib.umich.edu/bitstream/2027.42/111329/1/11_Report.pd
High signal-to-noise spectral characterization of the planetary-mass object HD 106906 b
We spectroscopically characterize the atmosphere of HD 106906b, a young
low-mass companion near the deuterium burning limit. The wide separation from
its host star of 7.1" makes it an ideal candidate for high S/N and
high-resolution spectroscopy. We aim to derive new constraints on the spectral
type, effective temperature, and luminosity of HD106906b and also to provide a
high S/N template spectrum for future characterization of extrasolar planets.
We obtained 1.1-2.5 m integral field spectroscopy with the VLT/SINFONI
instrument with a spectral resolution of R~2000-4000. New estimates of the
parameters of HD 106906b are derived by analyzing spectral features, comparing
the extracted spectra to spectral catalogs of other low-mass objects, and
fitting with theoretical isochrones. We identify several spectral absorption
lines that are consistent with a low mass for HD 106906b. We derive a new
spectral type of L1.51.0, one subclass earlier than previous estimates.
Through comparison with other young low-mass objects, this translates to a
luminosity of log()= and an effective temperature of
Teff= K. Our new mass estimates range between (hot start) and (cold start).
These limits take into account a possibly finite formation time, i.e., HD
106906b is allowed to be 0--3 Myr younger than its host star. We exclude
accretion onto HD 106906b at rates yr based on the fact that we observe no hydrogen (Paschen-,
Brackett-) emission. This is indicative of little or no circumplanetary
gas. With our new observations, HD 106906b is the planetary-mass object with
one of the highest S/N spectra yet. We make the spectrum available for future
comparison with data from existing and next-generation (e.g., ELT and JWST)
spectrographs.Comment: 11 pages, 5 figures. Accepted for publication in Astronomy &
Astrophysics. Fully reduced spectra will be made available for download on
CD
Patient-Reported Outcomes of Primary Total Ankle Arthroplasty in Patients Aged \u3c50 Years
Background:
Compared to more prevalent arthritic conditions, ankle arthritis is complicated by an earlier age of onset. Recently published data demonstrates excellent survivorship and complication rates in short-/midterm follow-up of younger patients who received a primary total ankle arthroplasty (TAA). Additionally, older TAA patients display comparable reported outcomes relative to hip/knee arthroplasty. However, there remains a paucity of literature surrounding the reported outcomes of younger patients undergoing TAA. Thus, our aim was to assess the reported outcomes of individuals aged \u3c50 years receiving a primary TAA. Methods:
A retrospective cohort analysis of adult patients \u3c50 years who received a primary total ankle replacement was conducted. Patient demographics, diagnosis, treatment, and outcome characteristics were recorded from a chart review of 41 patients with at least 1 year of postoperative clinical follow-up. Postoperative reported outcomes were obtained via telephone interviews. Primary outcomes that were measured included emotional and physical health, activity limitation, ambulation, and global health. Measures used included the 36-Item Short Form Health Survey (SF-36), Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health, and Sickness Impact Profile Ambulation. The functional outcomes in our study sample were compared with age- and gender-matched norms from a general US population, and 95% CIs were calculated for each functional outcome mean. Student t test was used for continuous variables, and χ2 analysis was used for categorical variables. Results:
Thirty-one of 41 eligible patients were reached for interview. The average age at surgery was 39.7 years. Clinical and radiographic follow-up was a mean of 51.6 months and 31.2 months following TAA, respectively. General health as measured with the SF-36 was not significantly different from age-/gender-matched norms. Eighty-seven percent of patients would choose to have a TAA again. Although 58% reported being limited in vigorous activities, 61% were able to ambulate frequently for long periods of time. On average, the patients did not report ongoing pain, and only 16% reported fatigue that hindered activities. Eighty-one percent reported returning to full employment and performing their duties without difficulty, and 84% reported they resumed all normal social activities. Primary implant survivorship was 93%. Conclusion:
Despite a younger age and potentially increased demands, patients aged \u3c50 years undergoing primary TAA are generally satisfied with their index procedure at a mean follow-up of nearly 5 years. Our findings of positive outcomes on their health and well-being may improve surgeon insight for TAA as an alternative treatment for younger individuals with end-stage ankle arthritis.
Level of Evidence: Level IV, case series
Phase curves of WASP-33b and HD 149026b and a New Correlation Between Phase Curve Offset and Irradiation Temperature
We present new 3.6 and 4.5 Spitzer phase curves for the highly
irradiated hot Jupiter WASP-33b and the unusually dense Saturn-mass planet HD
149026b. As part of this analysis, we develop a new variant of pixel level
decorrelation that is effective at removing intrapixel sensitivity variations
for long observations (>10 hours) where the position of the star can vary by a
significant fraction of a pixel. Using this algorithm, we measure eclipse
depths, phase amplitudes, and phase offsets for both planets at 3.6 and
4.5 . We use a simple toy model to show that WASP-33b's phase offset,
albedo, and heat recirculation efficiency are largely similar to those of other
hot Jupiters despite its very high irradiation. On the other hand, our fits for
HD 149026b prefer a very high albedo and an unusually high recirculation
efficiency. We also compare our results to predictions from general circulation
models, and find that while neither are a good match to the data, the
discrepancies for HD 149026b are especially large. We speculate that this may
be related to its high bulk metallicity, which could lead to enhanced
atmospheric opacities and the formation of reflective cloud layers in localized
regions of the atmosphere. We then place these two planets in a broader context
by exploring relationships between the temperatures, albedos, heat transport
efficiencies, and phase offsets of all planets with published thermal phase
curves. We find a striking relationship between phase offset and irradiation
temperature--the former drops with increasing temperature until around 3400 K,
and rises thereafter. Although some aspects of this trend are mirrored in the
circulation models, there are notable differences that provide important clues
for future modeling efforts
Specialized CNT-based Sensor Framework for Advanced Motion Tracking
In this work, we discuss the design and development of an advanced framework for high-fidelity finger motion tracking based on Specialized Carbon Nanotube (CNT) stretchable sensors developed at our research facilities. Earlier versions of the CNT sensors have been employed in the high-fidelity finger motion tracking Data Glove commercialized by Yamaha, Japan. The framework presented in this paper encompasses our continuing research and development of more advanced CNT-based sensors and the implementation of novel high-fidelity motion tracking products based on them. The CNT sensor production and communication framework components are considered in detail and wireless motion tracking experiments with the developed hardware and software components integrated with the Yamaha Data Glove are reported
Spitzer Secondary Eclipse Observations of Five Cool Gas Giant Planets and Empirical Trends in Cool Planet Emission Spectra
In this work we present Spitzer 3.6 and 4.5 micron secondary eclipse
observations of five new cool (<1200 K) transiting gas giant planets:
HAT-P-19b, WASP-6b, WASP-10b, WASP-39b, and WASP-67b. We compare our measured
eclipse depths to the predictions of a suite of atmosphere models and to
eclipse depths for planets with previously published observations in order to
constrain the temperature- and mass-dependent properties of gas giant planet
atmospheres. We find that the dayside emission spectra of planets less massive
than Jupiter require models with efficient circulation of energy to the night
side and/or increased albedos, while those with masses greater than that of
Jupiter are consistently best-matched by models with inefficient circulation
and low albedos. At these relatively low temperatures we expect the atmospheric
methane to CO ratio to vary as a function of metallicity, and we therefore use
our observations of these planets to constrain their atmospheric metallicities.
We find that the most massive planets have dayside emission spectra that are
best-matched by solar metallicity atmosphere models, but we are not able to
place strong constraints on metallicities of the smaller planets in our sample.
Interestingly, we find that the ratio of the 3.6 and 4.5 micron brightness
temperatures for these cool transiting planets is independent of planet
temperature, and instead exhibits a tentative correlation with planet mass. If
this trend can be confirmed, it would suggest that the shape of these planets'
emission spectra depends primarily on their masses, consistent with the
hypothesis that lower-mass planets are more likely to have metal-rich
atmospheres.Comment: 16 pages, 14 figures, accepted for publication in Ap
The European Register of Specialists in Clinical Chemistry and Laboratory Medicine
In 1997, the European Communities Confederation of Clinical Chemistry and Laboratory Medicine (EC4) set up a Register for European Specialists in Clinical Chemistry and Laboratory Medicine. The operation of the Register is undertaken by a Register Commission (EC4RC). During the last 10 years, more than 2000 specialists in Clinical Chemistry and Laboratory Medicine have joined the Register. In 2007, EC4 merged with the Federation of European Societies of Clinical Chemistry and Laboratory Medicine (FESCC) to form the European Federation of Clinical Chemistry and Laboratory Medicine (EFCC). A Code of Conduct was adopted in 2003 and a revised and updated version, taking account particularly of the guidelines of the Conseil Européen des Professions Libérales (CEPLIS) of which EFCC is a member, is presented in this article. The revised version was approved by the EC4 Register Commission and by the EFCC Executive Board in Paris on 6 November, 2008.Peer Reviewe
Hospital admissions for vitamin D related conditions and subsequent immune-mediated disease: record-linkage studies
PMCID: PMC3729414The electronic version of this article is the complete one and can be found online at: http://www.biomedcentral.com/1741-7015/11/171.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Atmospheric Retrieval of L Dwarfs: Benchmarking Results and Characterizing the Young Planetary Mass Companion HD 106906 b in the Near-infrared
© 2023. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0We present model constraints on the atmospheric structure of HD 106906 b, a planetary-mass companion orbiting at a ∼700 au projected separation around a 15 Myr old stellar binary, using the APOLLO retrieval code on spectral data spanning 1.1–2.5 μm. C/O ratios can provide evidence for companion formation pathways, as such pathways are ambiguous both at wide separations and at star-to-companion mass ratios in the overlap between the distributions of planets and brown dwarfs. We benchmark our code against an existing retrieval of the field L dwarf 2MASSW J2224–0158, returning a C/O ratio consistent with previous fits to the same JHK s data, but disagreeing in the thermal structure, cloud properties, and atmospheric scale height. For HD 106906 b, we retrieve C/O =0.53−0.25+0.15 , consistent with the C/O ratios expected for HD 106906's stellar association and therefore consistent with a stellar-like formation for the companion. We find abundances of H2O and CO near chemical equilibrium values for a solar metallicity but a surface gravity lower than expected, as well as a thermal profile with sharp transitions in the temperature gradient. Despite high signal-to-noise ratio and spectral resolution, more accurate constraints necessitate data across a broader wavelength range. This work serves as preparation for subsequent retrievals in the era of JWST, as JWST's spectral range provides a promising opportunity to resolve difficulties in fitting low-gravity L dwarfs and also underscores the need for simultaneous comparative retrievals on L-dwarf companions with multiple retrieval codes.Peer reviewe
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