2,462 research outputs found
Image formation in microwave holography
Microwave holograms are made without offset reference beam, but it has been found that Van der Lugt filter can be used to produce image offset. Also, filter permits "decoding" of holograms in contrast with usual practice of reconstructing visible-light analogs of original micro-wave wave fronts
Microwave holography for nondestructive testing
Holographic methods permit use of very large effective apertures so that weak signals can be collected over wide area and integrated to form image. Technique, modification of side-looking radar principle, can be used at very short ranges needed for nondestructive inspection of test specimens
Aquatic Invertebrate Community Structure, Biological Condition, Habitat, and Water Quality at Ozark National Scenic Riverways, Missouri, 2005-2014
Ozark National Scenic Riverways (OZAR) was established to protect the corridor of the Current River and its major tributary, the Jacks Fork. The Current River is one of the few remaining free-flowing rivers in the U.S., with much of its base flow coming from several large springs. To assess the biological condition of these rivers, aquatic invertebrate community structure was monitored from 2005 to 2014. Benthic invertebrate samples and associated habitat and water quality data were collected from each of nine sampling sites using a Slack-Surber sampler. The Stream Condition Index (SCI), a multimetric index that incorporates taxa richness, EPT (Ephemeroptera, Plecoptera, Trichoptera) richness, Shannon’s diversity index, and Hilsenhoff Biotic Index (HBI), was calculated. The benthic invertebrate fauna was diverse with 155 distinct taxa identified from all sites. Mean taxa richness was high, ranging from 22 to 30 among sites. The invertebrate taxa of the Current River and Jacks Fork are largely intolerant across all taxa represented (mean tolerance value= ~4.25). Mean HBI did not exceed 3.9 in the Current River or 4.4 for the Jacks Fork. Mean SCI scores across sampling sites generally were well above 16, indicating they are not impaired. Habitat and water quality data were summarized, but they were poorly correlated with individual invertebrate metrics. Sørenson’s similarity index was used to assess community similarity among sites, and similarity scores were then analyzed using ascendant hierarchical cluster analysis. Similarity among sites was 72% or greater. Cluster analysis showed that Current River and Jacks Fork sites clustered separately and in a downstream progression. The uppermost collection site on the Current River was most unlike the other sites, which probably relates to the distinct physical features of that site compared to the others. Nonmetric Multidimensional Scaling (NMDS) was used to evaluate the relationship of invertebrate metrics to habitat and water quality. The NMDS model was found to be a good fit (stress=0.04) and specific conductance, temperature, discharge, filamentous algae and aquatic vegetation were among the most important habitat variables in defining the relationship among sampling sites. The three lower Current River and Jacks Fork sites each were closely grouped in ordination space, but the three upper Current River sites were farther apart from each other. The influence of several large volume springs near those sites is suspected of producing such disparity through press type disturbances. Although the invertebrate communities and water quality in the Current River and Jacks Fork are largely sound and have high biological condition, ongoing and projected threats to these resources remain, and those threats largely originate outside park jurisdictional boundaries. Inherent variability of invertebrate community diversity across sites and years highlights the importance of using multi-metric assessments and multiyear monitoring to support management decisions
Conceptual and Technological Advancements in Visitor Use Management of Coastal and Estuarine Environments
This dissertation demonstrates the exploration and use of conceptual and technological advancements in the science of visitor use management (VUM). The goal of this effort is to help better understand visitors to park and protected areas (PPAs) and more specifically, better manage our coastal and estuarine environments (i.e., coastal protected areas (CPAs). These concepts and techniques are 1) further implementing the use of cellphone data in recreation ecology and VUM, 2) assessing the use of advanced imagery, virtual reality (VR), in visual-based methods to determine visitor indicators and thresholds, and 3) assessing visitor’s awareness of PPAs and how it influences their perceptions, attitudes, and behaviors towards recreation impacts and management. Results from Chapter 2 demonstrate the potential for the use of cellphone data in VUM and the considerations necessary to utilizing these data sources. The results from Chapter 3 find that the acceptability for the expansion of oyster mariculture in South Carolina can be influenced by a relatively limited amount of information if given to the public. This article also explored the efficacy of VR technologies in field-based survey research and outlines best practices. Results from Chapter 4 conceptualizes, measures, and assesses a newly created Visitor Awareness Index (VAI) and finds modest differences in visitor perceptions and characteristics among the sample but opens the door for further research. To better manage and protect our coastal areas we must find better ways to understand visitor use and its impacts
An investigation concerning the authorship, date, and purpose of the fourth gospel
https://place.asburyseminary.edu/ecommonsatsdissertations/2047/thumbnail.jp
The Development of Freshman College Calculus Students\u27 Mathematics Identity and How it Predicts Students\u27 Career Choice
There is a need for research to explore the connections between students\u27 self-perceptions and their goals and future engagement with mathematics. This is particularly the case when considering that student interest declines as they transition through K-12 and gender differences continue to persist in mathematics related careers. Knowing how students identify with mathematics might provide insight into students\u27 self-perceptions of mathematics and how these perceptions relate to students\u27 career choices. This quantitative study uses a mathematics identity framework based upon students\u27 self-perceptions related to mathematics. Specifically, students\u27 self-perceptions relating to mathematics interest, recognition by others in mathematics, and mathematical competence and performance were explored. Data were drawn from the Factors Influencing College Success in Mathematics (FICS-Math) project, which was a national survey of college students enrolled in a single-variable calculus course at 2- and 4- year institutions across the United States. This survey yielded a total of 10,492 surveys from students attending 336 college calculus courses/sections at 134 institutions. The results highlight the salience of the mathematics identity framework, indicating that mathematics interest, being recognized by others in mathematics, and beliefs about their ability to perform and understand mathematics were directly related to students\u27 mathematics identity. This led to the construction of a structural equation model for the mathematics identity framework detailing the relationship between the sub-constructs of mathematics identity. Results also indicated that gender differences in students\u27 self-perceptions still exist though effect sizes were small. In addition, self-perceptions as seen through a mathematics identity proxy were shown to be a strong predictor of students\u27 career choice as a mathematician, as a science/math teacher, and in STEM fields. This study establishes an explanatory framework for mathematics identity that provides insight into gender differences and students\u27 career choices in mathematics related fields. Implications of this study are that students\u27 self-perceptions might provide insight into why students persist in areas related to mathematics, how teachers might help students develop a positive sense of affiliation with mathematics, and how this mathematics identity framework might provide a lens for future research
Rapid, Low-Cost Biosensor for Water-Borne Pathogens in Low-Resource Environments
When testing water quality, “microbiological results typically require a minimum of 24 hours to complete” due to reliance on the traditional and inexpensive cultivation method. In 2000, an isothermal DNA amplification method termed loop-mediated isothermal amplification (LAMP) was invented allowing for microbiological assessments to be performed in less than one hour without the need for an expensive thermocycler. In 2013, the World Health Organization reported LAMP as an “attractive diagnostic platform for resource-poor settings: it is fast [15-40 min], isothermal [requiring only a heat block], robust to inhibitors and reaction conditions that usually adversely affect PCR methods, and it generates a result that can be detected with the naked eye.”The objective of this research project was to develop a low-cost, LAMP-based diagnostic device for water-borne pathogens that could be used on low-resource environments. We developed a LAMP-based test to detect the ipaH gene shared by enteroinvasive E.coli and S. flexina. Our designed heating element for LAMP was made of a phase change material, plastic case, high-resistance nichrome wire, and a USB port. We used a portable battery pack to power the device. This research project was part of the 2016 EPA People, Prosperity, and the Planet Student Design Competition
Hutchinson Family Biographies
The following family biographical information was compiled by graduate student intern Brittney Teal-Cribbs using sources from Western Oregon University Archives
Davidson Family Biographies
The following family biographical information was compiled by graduate student intern Brittney Teal-Cribbs using sources from Western Oregon University Archives
Ground Family Biographies
The following family biographical information was compiled by graduate student intern Brittney Teal-Cribbs using sources from Western Oregon University Archives
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