Design of a compliant wheel for a miniature rover to be used on Mars

The Jet Propulsion Laboratory has identified the need for a compliant wheel for a miniature martian rover vehicle. This wheel must meet requirements of minimum mass, linear radial deflection, and reliability in cryogenic conditions over a five year lifespan. Additionally, axial and tangential deflections must be no more than 10 percent of the radial value. The team designed a wheel by use of finite element and dimensionless parameter analysis. Due to the complex geometry of the wheel, a finite element model describing its behavior was constructed to investigate different wheel configurations. Axial and tangential deflections were greatly reduced but did not meet design criteria. A composite material was selected for its high strength, toughness, fatigue resistance, and damping characteristics. The team chose a Kevlar fiber filled thermoplastic composite. This report is divided into four primary sections. First, the introduction section gives background information, defines the task, and discusses the scope and limitations of the project. Second, the alternative designs section introduces alternative design solutions, addresses advantages and disadvantages of each, and identifies the parameters used to determine the best design. Third, the design solution section introduces the methods used to evaluate the alternates, and gives a description of the design process used. Finally, the conclusion and recommendations section evaluates the wheel design, and offers recommendations pertaining to improvement of the design solution

Clinician identification of youth abusing over-the-counter products for weight control in a large U.S. integrated health system

Background: Abuse of over-the-counter (OTC) products, such as diet pills and laxatives, for weight control by adolescents is well-documented and can precipitate serious medical conditions. Yet only a small percentage of youth with disordered weight control behaviors receive treatment. The objective of this study was to examine how often clinicians communicate with youth with symptoms consistent with abuse of OTC products for weight control about possible use of these products. We used electronic medical records and administrative claims for services for 53,229 12 to 17 year old patients receiving care from an integrated health system in the U.S. Northwest from August 2007 to December 2010. We examined electronic text of clinical notes to identify encounters in which the clinician noted one of 10 metabolic conditions potentially associated with abuse of OTC products (diet pills, laxatives, diuretics, ipecac, orlistat, and alli®) for weight control and then assessed whether clinicians noted communication with adolescent patients about possible use of OTC products for weight control. Results: We identified 130 (0.2% of sample) patients with clinical notes indicating one or more of the metabolic conditions. In clinical notes for only four (3.1%) of these patients did clinicians document suspicion or communication about possible abuse of the OTC products. All four had a previous eating disorder diagnosis. In the 12 months subsequent to the clinical encounter in which a metabolic disturbance was identified, medical notes for only three (2.3%) of the 130 patients indicated clinician suspicion or communication about possible abuse of these products or an eating disorder. Conclusions: Clinicians are missing a critical window of opportunity to query adolescents when presenting with suspicious metabolic disturbances about possible abuse of OTC products for weight control. Clinicians may need more training to detect OTC product abuse, and electronic medical records should prompt more thorough enquiry

Focus diverse phase retrieval testbed development of continuous wavefront sensing for space telescope applications

Continuous wavefront sensing on future space telescopes allows relaxation of stability requirements while still allowing on-orbit diffraction-limited optical performance. We consider the suitability of phase retrieval to continuously reconstruct the phase of a wavefront from on-orbit irradiance measurements or point spread function (PSF) images. As phase retrieval algorithms do not require reference optics or complicated calibrations, it is a preferable technique for space observatories, such as the Hubble Space Telescope or the James Webb Space Telescope. To increase the robustness and dynamic range of the phase retrieval algorithm, multiple PSF images with known amount of defocus can be utilized. In this study, we describe a recently constructed testbed including a 97 actuator deformable mirror, changeable entrance pupil stops, and a light source. The aligned system wavefront error is below ~30nm. We applied various methods to generate a known wavefront error, such as defocus and/or other aberrations, and found the accuracy and precision of the root mean squared error of the reconstructed wavefronts to be less than ~10nm and ~2nm, respectively. Further, we discuss the signal-to-noise ratios required for continuous dynamic wavefront sensing. We also simulate the case of spacecraft drifting and verify the performance of the phase retrieval algorithm for continuous wavefront sensing in the presence of realistic disturbances

Use of Statistical Analysis of Acoustic Emission Data on Carbon-Epoxy COPV Materials-of-Construction for Enhanced Felicity Ratio Onset Determination

Broadband modal acoustic emission (AE) data were acquired during intermittent load hold tensile test profiles on Toray T1000G carbon fiber-reinforced epoxy (C/Ep) single tow specimens. A novel trend seeking statistical method to determine the onset of significant AE was developed, resulting in more linear decreases in the Felicity ratio (FR) with load, potentially leading to more accurate failure prediction. The method developed uses an exponentially weighted moving average (EWMA) control chart. Comparison of the EWMA with previously used FR onset methods, namely the discrete (n), mean (n (raised bar)), normalized (n%) and normalized mean (n(raised bar)%) methods, revealed the EWMA method yields more consistently linear FR versus load relationships between specimens. Other findings include a correlation between AE data richness and FR linearity based on the FR methods discussed in this paper, and evidence of premature failure at lower than expected loads. Application of the EWMA method should be extended to other composite materials and, eventually, composite components such as composite overwrapped pressure vessels. Furthermore, future experiments should attempt to uncover the factors responsible for infant mortality in C/Ep strands

Structural basis for complement factor H-linked age-related macular degeneration

This is the final version of the article. Available from the publisher via the DOI in this record.Nearly 50 million people worldwide suffer from age-related macular degeneration (AMD), which causes severe loss of central vision. A single-nucleotide polymorphism in the gene for the complement regulator factor H (FH), which causes a Tyr-to-His substitution at position 402, is linked to approximately 50% of attributable risks for AMD. We present the crystal structure of the region of FH containing the polymorphic amino acid His402 in complex with an analogue of the glycosaminoglycans (GAGs) that localize the complement regulator on the cell surface. The structure demonstrates direct coordination of ligand by the disease-associated polymorphic residue, providing a molecular explanation of the genetic observation. This glycan-binding site occupies the center of an extended interaction groove on the regulator's surface, implying multivalent binding of sulfated GAGs. This finding is confirmed by structure-based site-directed mutagenesis, nuclear magnetic resonance-monitored binding experiments performed for both H402 and Y402 variants with this and another model GAG, and analysis of an extended GAG-FH complex.B. Prosser is funded by the Wellcome Trust Structural Biology Training Program (075415/Z/04/Z). S. Johnson and P. Roversi were funded by grants to S.M. Lea from the Medical Research Council (MRC) of the United Kingdom (grants G0400389 and G0400775). D. Uhrin and P.N. Barlow were funded by the Wellcome Trust (078780/ Z/05/Z). S.J. Clark was funded by an MRC Doctoral Training Account (G78/7925), and R.B. Sim and A.J. Day were funded by MRC core funding to the MRC Immunochemistry Unit

Placemaking in Metro East Springfield - Creating a Landscape Framework

PLACEMAKING IN METRO EAST SPRINGFIELD - Creating a Landscape Framework Placemaking in Metro East Springfield – Creating a Landscape Framework provides strategies to use the landscape as a framework for rebuilding community in a downtown urban area that has “good bones” but has been neglected and overlooked for decades. A catalyst for the development of project area is the recent acquisition of the historical 1916 Willys Overland building through a developer. The Graduate Urban Design Studio 2018 developed five proposals for urban revitalization in the area that are centered on the landscape. The programming of the proposals was developed in collaboration with neighborhood representatives and stakeholders of the area. The public response was very positive and the project got recognized in the local press and media. The Landscape Framework is interwoven with cultural activities such as public art and education, new opportunities for small neighborhood commerce, future employment and possibilities for new housing. The Landscape Framework will bring expand urban greening and will reduce heat island effects to reduce the impact of climate change. The presented Landscape Framework will guide the future of the area as overlapping and simultaneous measures. They encompass: Tangible tactile interventions on streets, facades and underutilized lots that change the perception of the landscape at low cost but are highly effective. New parks that create areas for recreation and contemplation. Greenway promenades connect to shorten long blocks and create a network to the neighboring residential areas. Establishment of urban agriculture activities to build community, provide food security and education. Collaboration with existing organizations in Springfield that are actively involved with urban agriculture: Gardening the Community (GTC) Springfield, Wellspring Harvest first commercial hydroponic greenhouse, UMass Extension and UMass Permaculture, Springfield Technical Community College (STCC). Walkable streets through extensive street tree plantings, widening of sidewalks, adding bicycle lanes and introducing shared multi-functional streets for community events. Stormwater Management through bioswales along streets, green roofs, larger infiltration areas in new parks and porous pavement. Promotion of alternative stormwater management through education and artistic interventions. People want to connect culturally and socially. Creating a sense of place, common ownership, and connectivity are a vital part of a sustainable community. This includes: Complimentary cultural, art, craft and education at new Maker-Spaces. Daycare Center and other childcare services. Outdoor pop-up business opportunities for food vendors such as food carts and trucks. Indoor pop-up business opportunities in abandoned or underutilized buildings. Adaptive reuse of existing architecture and infill. Diversification of housing market with inclusion of market-rate housing to create a more balanced economy. Legal framework through zoning changes and permitting that supports small businesses, reduces bureaucratic burdens and secures public open green space

Adjusting the melting point of a model system via Gibbs-Duhem integration: application to a model of Aluminum

Model interaction potentials for real materials are generally optimized with respect to only those experimental properties that are easily evaluated as mechanical averages (e.g., elastic constants (at T=0 K), static lattice energies and liquid structure). For such potentials, agreement with experiment for the non-mechanical properties, such as the melting point, is not guaranteed and such values can deviate significantly from experiment. We present a method for re-parameterizing any model interaction potential of a real material to adjust its melting temperature to a value that is closer to its experimental melting temperature. This is done without significantly affecting the mechanical properties for which the potential was modeled. This method is an application of Gibbs-Duhem integration [D. Kofke, Mol. Phys.78, 1331 (1993)]. As a test we apply the method to an embedded atom model of aluminum [J. Mei and J.W. Davenport, Phys. Rev. B 46, 21 (1992)] for which the melting temperature for the thermodynamic limit is 826.4 +/- 1.3K - somewhat below the experimental value of 933K. After re-parameterization, the melting temperature of the modified potential is found to be 931.5K +/- 1.5K.Comment: 9 pages, 5 figures, 4 table

The MAPS Adaptive Secondary Mirror: First Light, Laboratory Work, and Achievements

The MMT Adaptive Optics exoPlanet Characterization System (MAPS) is a comprehensive update to the first generation MMT adaptive optics system (MMTAO), designed to produce a facility class suite of instruments whose purpose is to image nearby exoplanets. The system's adaptive secondary mirror (ASM), although comprised in part of legacy components from the MMTAO ASM, represents a major leap forward in engineering, structure and function. The subject of this paper is the design, operation, achievements and technical issues of the MAPS adaptive secondary mirror. We discuss laboratory preparation for on-sky engineering runs, the results of those runs and the issues we discovered, what we learned about those issues in a follow-up period of laboratory work, and the steps we are taking to mitigate them.Comment: 22 pages, 22 images, 2 tables, submitted to SPIE Proceedings (Unconventional Imaging, Sensing and Adaptive Optics 2023 Conference

1968: Abilene Christian College Bible Lectures - Full Text

CROWNING FIFTY YEARS” Being the Fiftieth Annual ABILENE CHRISTIAN COLLEGE BIBLE LECTURES - 1968 J. D. THOMAS, LECTURESHIP DIRECTOR, EDITOR Published by ABILENE CHRISTIAN COLLEGE ACC Station, Abilene, Texas 7960