1,938 research outputs found
The practical limit of loading nickel hydroxide electrodes
The effect of compression loads on positive nickel hydroxide electrodes is reported. Results show the electrodes could be compressed up to 20,000 kilograms without any change in capacity
Process for synthesizing and formulating condensed ring polymers
Chemical process for forming low molecular weight, fully cyclized heteroaromatic prepolymers under conditions which limit chain extension or branching is described. Exact procedures used in conducting chemical reaction are defined. Advantages of process over conventional methods are presented
Method for forming pyrrone molding powders and products of said method
The formation of pyrrone resins of the ladder or semiladder structure is described. The technique involves initial formation of fully cyclized prepolymers having an average degree of polymerization of about 1.5, one with acidic terminal groups, another with amine terminal groups. Thereafter the prepolymers are intimately admixed on a 1:1 stoichiometric basis. The resulting powder mixture is molded at elevated pressures and temperatures to form a fully cyclized resin
Silent, no more: The 1974 Kanawha County textbook controversy and the rise of conservatism in America
Silent, No More explores the 1974 Kanawha County textbook controversy, and places it within the context of the rise of conservatism in America. This rise can be seen in the upsurge of grassroots, community activism in the seventies, the White Backlash associated with the campaigns of George Wallace, the New Right, and the New Christian Right. The thesis shows how the Kanawha County protestors\u27 words and actions paralleled that of aforementioned conservative movements, creating, in the end, one of the first manifestations of a single-issue conservative uprising in the seventies
Genetic variation and population structure in the endangered Houston toad in contrast to its common sympatric relative, the coastal plain toad
Title from PDF of title page (University of Missouri--Columbia, viewed on October 25, 2010).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Dissertation advisor: Dr. Raymond D. Semlitsch and Dr. Michael R. J. Forstner.Vita.Ph. D. University of Missouri--Columbia 2010.I determined the number of populations, the levels of genetic diversity within and among populations, and migration/movement rates at the landscape and fine scales in the endangered Houston toad, Bufo houstonensis (Anura: Bufonidae) using mitochondrial sequence data and microsatellite loci. Genetic clustering analyses indicate nine populations across the range. The most divergent population was in Austin County, Texas. Genetic diversity was high across the range and within populations. I also examined population genetic structure and diversity in a common, sympatric congener, the coastal plain toad (Bufo nebulifer). Bufo houstonensis and B. nebulifer have comparable levels of genetic diversity, but B. nebulifer appears to migrate less frequently or over less distance than its endangered congener. Finally, I investigated the baseline levels of genetic admixture, or hybridization, in B. houstonensis. Admixture between B. houstonensis and two sympatric species (B. nebulifer and Bufo woodhousii) was detected. With continued habitat alteration and rising temperatures, both habitat isolation and offset breeding season have already partially broken down as isolating mechanisms and may deteriorate further; consequently, opportunities for hybridization events will increase. Conservation recommendations for B. houstonensis include supplementation programs to increase the number of individuals, preservation of all three habitat types (breeding/nursery, occupied, and dispersal), special attention towards the Austin County population, and involvement of the general public in conservation.Includes bibliographical reference
Data-Driven Fuzzy Weights-Of-Evidence Model for Identification of Potential Zeolite-Bearing Environments on Mars
The evolution of the climate and hydrochemistry of Mars is still a mystery but it must have been at least occasionally warm and wet to have formed the ancient fluvial and lacustrine landforms observed today. Terrestrial examples and geochemical modeling under proposed early Mars conditions show that zeolite minerals are likely to have formed under alkaline (pH \u3e 8) conditions with low water/rock ratio and surface temperatures below 150°C. The identification and spatial association of zeolites on the surface of Mars could thus be used to reconstruct the paleoclimate, paleohydrochemistry, and geological evolution of some locations on Mars. Previous studies identified the zeolite analcime and discuss the difficulties of identifying other zeolite species on the surface of Mars using orbital spectroscopy. We used published global mineralogical, geological, geomorphological, hydrological, physical, and elemental abundance maps and the locations of hydrous minerals detected and mapped using orbital data to create a map that delineates favorable areas to look for zeolites on Mars. We used the data-driven fuzzy-based Weights-of-Evidence method to identify and map favorable areas for zeolites on the surface of Mars up to ±40° latitude toward the poles. The final map shows that the eastern and western Arabia deposits, some sites in the Medusae Fossae formation, and some areas within and near Valles Marineris, Mawrth Vallis, highlands north of Hellas, and the Terra Cimmeria and Terra Sirenum regions would be favorable areas to look for zeolites using targeted orbital spectral analysis or future in situ observations
The biomechanics of sensory organs
Studies of mechanosensory systems have largely focused on the filter characteristics of their neural components in relation to their ultimate function. Less attention has focused on the role of the physical structure of the sensory organ which also acts as a mechanical filter of the sensory input. This biomechanical filtering is readily apparent in the case of several mechanosensory systems that transduce information about the deformations of the sensory organs in response to external forces. Because these deformations critically depend on the geometry and material properties of the mechanosensory organs, it is necessary to conduct focused studies on the biomechanical characteristics of these organs when studying the encoding properties of the mechanosensory system. Modern experimental tools such as Laser Doppler Vibrometry and computational tools such as Computational Fluid Dynamics and Finite Element Analysis provide the means for determining the sensory pre-filtering properties of small-scale mechanosensory structures. In all the cases covered in this review, the physical properties of the sensory organs play a central role in determining the signals received by the nervous system
We’re in This Together: Student Motivation and Faculty Support in Online Degree Advancement During the COVID-19 Pandemic
The purpose of this study was to identify the motivation for continued learning and degree attainment in online degree advancement (DA) respiratory care students (those with an associate degree pursuing a bachelor’s degree) during a pandemic and the types of support needed for academic success in the online learning environment. The design of the study was convergent mixed-methods descriptive survey research. Items from the Academic Motivation Scale-College Version (AMS-C) were used to assess the construct. Additionally, open-ended questions allowed for narrative responses related to the pandemic pressures, motivation regulation, and faculty support. One hundred twenty-three students completed various components of the survey. Respondents were both intrinsically and extrinsically motivated to continue to pursue their advanced degrees despite the pandemic. Students self-identified as being determined to achieve their goals and that support from family, friends, colleagues, and faculty helped them achieve their goals along with their instructors’ flexibility which helped ensure student success during the pandemic. Despite the pandemic, respiratory therapy (RT) students pursuing an advanced degree are self-determined and have a genuine love of learning, which helps regulate their motivation to continue. DA students in respiratory care appreciated flexible and supportive instructors in meeting their academic needs
The Effects Of Medicare Payment Changes On Nursing Home Staffing
In light of persistent shortcomings in nursing home care quality and evidence that lower nurse staffing levels could be harmful to residents, we examine whether staffing levels are affected by changes in Medicare reimbursement rates. We exploit a 2006 change in Medicare’s methodology for adjusting provider payments for geographic differences in costs, a change that generated plausibly exogenous variation in nursing facility reimbursement rates. Our method compares facilities with higher and lower shares of Medicare resident days, which were differentially exposed to the payment changes we examine. Using panel data on US nursing homes from 2003 through 2009, we find that higher Medicare payments increased nurse staffing hours per resident day. Additional results suggest that changes in Medicare payments did not affect other measures of quality
Jarosite in a Pleistocene East African saline-alkaline paleolacustrine deposit: Implications for Mars aqueous geochemistry
Jarosite occurs within altered tephra from the saline‐alkaline paleolake deposits of Pliocene‐Pleistocene Olduvai Gorge, Tanzania. Zeolites (mainly phillipsite), authigenic K‐feldspar, and Mg/Fe‐smectites dominate the mineral assemblage, indicating salinealkaline diagenetic conditions (pH > 9). As jarosite is ordinarily an indicator of acidic conditions on Earth and Mars, its association with such undisputed high‐pH indicators is unexpected. Of 55 altered tephra samples collected from the paleolake basin and margin deposits, eleven contained jarosite detectable by X‐ray Diffraction (XRD) (>0.15%). Mössbauer spectroscopy, Fourier Transform Infrared Reflectance (FTIR), Electron Probe Microanalysis (EPMA), X‐ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM) analyses confirm the presence and nature of the jarosite. This paper documents this occurrence and presents mechanisms that could produce this unusual and contradictory mineral assemblage. We favor a mechanism by which jarosite formed recently, perhaps as modern ground and meteoric water interacted with and oxidized paleolacustrine pyrite, providing local and temporary acidic conditions. However, local groundwater (at modern springs) has a pH > 9. In recent studies of Mars, the presence of jarosite or other Fe or Mg sulfates is often used to indicate dominantly acidic conditions. Regardless, the current study shows that jarosite can form in sediments dominated by alkaline minerals and solutions. Its coexistence with Mg/Fe smectites in particular makes it relevant to recent observations of Martian paleolakes
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