402 research outputs found
Development of a New, Precise Near-infrared Doppler Wavelength Reference: A Fiber Fabry-Perot Interferometer
We present the ongoing development of a commercially available Micron Optics
fiber-Fabry Perot Interferometer as a precise, stable, easy to use, and
economic spectrograph reference with the goal of achieving <1 m/s long term
stability. Fiber Fabry-Perot interferometers (FFP) create interference patterns
by combining light traversing different delay paths. The interference creates a
rich spectrum of narrow emission lines, ideal for use as a precise Doppler
reference. This fully photonic reference could easily be installed in existing
NIR spectrographs, turning high resolution fiber-fed spectrographs into precise
Doppler velocimeters. First light results on the Sloan Digital Sky Survey III
(SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE)
spectrograph and several tests of major support instruments are also presented.
These instruments include a SuperK Photonics fiber supercontinuum laser source
and precise temperature controller. A high resolution spectrum obtained using
the NIST 2-m Fourier transform spectrometer (FTS) is also presented. We find
our current temperature control precision of the FFP to be 0.15 mK,
corresponding to a theoretical velocity stability of 35 cm/s due to temperature
variations of the interferometer cavity.Comment: 16 pages, 11 figures. To appear in the proceedings of the SPIE 2012
Astronomical Instrumentation and Telescopes conferenc
Adapting an Elementary School Nutrition Context Assessment for High School Settings and Students
The school nutrition context is comprised of supportive environmental features, programs, policies, and social relationships that shape students’ healthy dietary choices and patterns. When engaging students as change agents, advocates, and partners in making healthy nutrition choices easier, environmental assessment tools developed for adults may be too complex or inappropriately tailored for youth. Adolescents need practical, user-tailored tools that reliably measure the food and beverage environments they encounter in school to inform youth-led changes to the school nutrition context. To meet this need, an evidence-based school environmental assessment was adapted for use in high schools by students as evaluators. Cooperative Extension educators engaged students in experiential learning to adapt the nutrition component of an environmental tool (SPAN-ET) designed for elementary school contexts to high school applications. The resulting tool is a comprehensive nutrition-specific adaptation that incorporates considerations of food security, structures for youth-driven data collection, and data-identified areas for action. The tool was adapted in one high school setting and piloted in three additional high schools. Student-generated data were used to prioritize and plan policy, systems, and environmental strategies aimed at increasing healthy food/beverage access and supporting healthy eating/drinking behaviors to reduce hunger and obesity risk factors in schools
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School zone : a new model for suburban development in Montana
“The last, best place,” Montana, has experienced sustained, rapid population growth in recent years. Millennials and Baby Boomers alike flock to the state to stake their claim on some of the last remaining housing markets that offer what many perceive as the “American Dream” of an affordable, suburban home in a small town. This population growth has sparked extensive suburban development throughout the state, prompting many public-school districts to build new facilities to accommodate this growth. Contemporary school siting practices favor large sites, which are usually found only at the edges of existing development. Once built, these new facilities attract home builders and families, further catalyzing suburban sprawl development (Beaumont and Pianca, 2002). This dynamic represents a classic “tragedy of the commons” case for government intervention at several levels. Continued, uncoordinated growth threatens the character of Montana cities. Contemporary suburban development patterns contribute to traffic safety hazards and congestion. The desirability of small, county schools drives population growth, pushing cash-strapped school districts to their limits. This report explores, through case studies, the ways in which status quo school siting (site acquisition) practices, local regulations, and legislation all contribute to fiscally unsustainable and dangerous suburban development patterns. The final chapter proposes a “School Zone” tool that coordinates local jurisdictions (city, county, school district) to leverage public investment in new school facilities as a means of creating more fiscally sustainable, compact, adaptable suburban development that provides a steadier student population, and safer cities in which those children might liveCommunity and Regional PlanningArchitectur
Liming Minnesota Soils
This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu
Combining cosmological datasets: hyperparameters and Bayesian evidence
A method is presented for performing joint analyses of cosmological datasets,
in which the weight assigned to each dataset is determined directly by it own
statistical properties. The weights are considered in a Bayesian context as a
set of hyperparameters, which are then marginalised over in order to recover
the posterior distribution as a function only of the cosmological parameters of
interest. In the case of a Gaussian likelihood function, this marginalisation
may be performed analytically. Calculation of the Bayesian evidence for the
data, with and without the introduction of hyperparameters, enables a direct
determination of whether the data warrant the introduction of weights into the
analysis; this generalises the standard likelihood ratio approach to model
comparison. The method is illustrated by application to the classic toy problem
of fitting a straight line to a set of data. A cosmological illustration of the
technique is also presented, in which the latest measurements of the cosmic
microwave background power spectrum are used to infer constraints on
cosmological parameters.Comment: 12 pages, 6 figures, submitted to MNRA
A seminormal form for partition algebras
Using a new presentation for partition algebras (J. Algebraic Combin.
37(3):401-454, 2013), we derive explicit combinatorial formulae for the
seminormal representations of the partition algebras. These results generalise
to the partition algebras the classical formulae given by Young for the
symmetric group.Comment: Published version. 51 pages, includes figures and table
High Turnover Among State Health Officials/Public Health Directors: Implications for the Public's Health
State health officials (SHOs) serve a critical role as the leaders of state public health systems. Despite their many responsibilities, there is no formal process for preparation to become an SHO, and few requirements influence the selection of an SHO. Furthermore, to date, no studies have examined SHO tenure or their experiences
Integrating Renewable Energy Requirements Into Building Energy Codes
This report evaluates how and when to best integrate renewable energy requirements into building energy codes. The basic goals were to: (1) provide a rough guide of where we’re going and how to get there; (2) identify key issues that need to be considered, including a discussion of various options with pros and cons, to help inform code deliberations; and (3) to help foster alignment among energy code-development organizations. The authors researched current approaches nationally and internationally, conducted a survey of key stakeholders to solicit input on various approaches, and evaluated the key issues related to integration of renewable energy requirements and various options to address those issues. The report concludes with recommendations and a plan to engage stakeholders. This report does not evaluate whether the use of renewable energy should be required on buildings; that question involves a political decision that is beyond the scope of this report
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