865 research outputs found
Ryan Kerney, Assistant Professor of Biology
In this last Next Page column of 2017, Ryan Kerney, Assistant Professor of Biology, shares some of his favorite science writers in the field of “evo devo;” his go-to science news sources and podcasts (note: “This Week in Parasitism” is a must-listen!); what he would ask Charles Darwin if given the chance; which books he likes to give as gifts; his favorite author of all time; and where he finds great recommendations for what to read next
Daniel DeNicola, Professor of Philosophy
In this issue of Next Page, Professor of Philosophy Daniel DeNicola reveals his appreciation for mysteries, especially those focused on manuscripts or works of art, and how his incessant childhood habit of reading the backs of cereal boxes at breakfast led his parents to buy him a set of Children\u27s Classics and his very own encyclopedia-sold in installments at the supermarket
Dan Gilbert, Levan Professor of Ethics and Management
In this latest edition of Next Page, Dan Gilbert, the David M. LeVan Professor of Ethics and Management, shares with us books that inspired his teaching career, his love of baseball (1,100+ games and counting!), and the activities he’s looking forward to as he shakes off the Gettysburg winter and settles into retirement in sunny Southern California. We will miss you, Dan
Shear stress cleaning for surface departiculation
A cleaning technique widely used by the nuclear utility industry for removal of radioactive surface contamination has proven effective at removing non-hazardous contaminant particles as small as 0.1 micrometer. The process employs a controlled high velocity liquid spray inside a vapor containment enclosure to remove particles from a surface. The viscous drag force generated by the cleaning fluid applies a shear stress greater than the adhesion force that holds small particles to a substrate. Fluid mechanics and field tests indicate general cleaning parameters
Validation of an Operationalized Model of Iso-Ahola’s Theory of Tourism Motivation: A Case in Point-to-Point Suborbital Space Travel
The purpose of the study was to validate Snepenger, King, Marshall, and Uysal’s (2006) model of Iso-Ahola’s (1982) theory of tourism motivation for use in point-to-point suborbital space tourism research. No previous research was discovered, which assessed point-to-point suborbital space flight within the theoretical foundation of the theory of tourism motivation. Snepenger et al.’s (2006) model was assessed as published, and exploratory factor analysis (EFA) failed to produce data fitting the four dimensions. The researchers modified the item descriptions based on research. Using a second sample, the modified model was assessed. EFA produced four factors with adequate convergent and discriminant validity. Confirmatory factor analysis produced good model fit with adequate construct validity. The study validated the operationalized model of the theory of tourism motivation in United States participants providing a valid and reliable scale for use in future suborbital space travel research
A complex relationship between immunity and metabolism in Drosophila diet-induced insulin resistance
The Genus Striga (Scrophulariaceae) in Africa
Twenty-eight species and six subspecies of the hemiparasitic genus Striga Lour., witchweed, occur in Africa. Twenty-two species are endemic. Witchweeds occur throughout the continent with greatest diversity in the grasslands and savannas north of the equator. Striga gesnerioides (Willd.) Vatke and S. hermonthica (Del.) Benth. have developed host-specific strains that may have distinct morphotypes. me accord these no formal taxonomic status. Striga hermonthica and S. asiatica (L.) Kuntze, limited to agroecosystems, may be recently derived from non-ruderal species. Striga hirsuta Benth. and S. lutea Lour., sometimes treated as conspecific with S. asiatica, are recognized as distinct species restricted to natural ecosystems. Striga linearifolia Hepper, with its strongly bilabiate corolla and perennial habit, is considered as a subspecies of S. bilabiata (Thunb.) Kuntze. Striga baumannii Engl. and S. fulgens Hepper are excluded from the genus. Striga baumannii has tuberous roots and a ligneous calyx and may represent a distinct genus. Striga fulgens, with free petals, is aligned with Chascanum E. Mey. in the Verbenaceae
A Comparison of Collaborative Practice and Teacher Leadership Between Low-Performing and High-Performing Rural Kentucky High Schools
This article reports the findings of the 2011 results of ‘very rural’ Kentucky high schools on the Teaching, Empowering, Leading and Learning (TELL) Survey to determine whether differences existed between high and low performing rural schools across specific survey items. Schools with ACT scores one standard deviation (or more) above their predicted value were compared to rural high schools where students’ ACT scores were one standard deviation (or more) below their predicted value. Beale Codes of seven through nine from the United States Department of Agriculture were used to identify very rural Kentucky high schools. Very rural high schools identified as high-performing demonstrated significantly different results on survey items related to a culture of collaboration and teacher leadership than rural high schools identified as low performing. The survey suggested that in high-performing schools, the principal and teachers supported each other in their development as instructional leaders, and established communication and collaboration skills with families and community stakeholders
Field trial for air entrained grout enriched roller compacted concrete
Presented at the Protections 2016: 2nd international seminar on dam protection against overtopping: concrete dams, embankment dams, levees, tailings dams held on 7th-9th September, 2016, at Colorado State University in Fort Collins, Colorado, USA. The increasing demand for dam and levee safety and flood protection has motivated new research and advancements and a greater need for cost-effective measures in overtopping protection as a solution for overtopping concerns at levees and dams. This seminar will bring together leading experts from practice, research, development, and implementation for two days of knowledge exchange followed by a technical tour of the Colorado State University Hydraulic Laboratory with overtopping flume and wave simulator. This seminar will focus on: Critical issues related to levees and dams; New developments and advanced tools; Overtopping protection systems; System design and performance; Applications and innovative solutions; Case histories of overtopping events; Physical modeling techniques and recent studies; and Numerical modeling methods.Includes bibliographical references.Roller compacted concrete (RCC) is frequently used to armor earthen embankments for passing extreme floods and to construct gravity dams and stepped spillways. Early experience on RCC dam applications in the 1980s showed a tendency for seepage to develop along the lift lines. Therefore, RCC dam designers started including an upstream facing system as a watertight barrier. An alternative facing material that has been used extensively overseas and is starting to gain more widespread acceptance in the United States is Grout Enriched RCC (GERCC). The grout enriched method of face construction has been shown to be less expensive than other facing options, particularly on larger dam projects, and has also been used on exposed RCC embankment overtopping projects. However, in the United States, the use of GERCC technology has been fairly limited, primarily due to concern over the material’s freeze-thaw resistance. The objective of this project is to develop a grout formulation and construction technique that allows the production of air entrained GERCC. The study includes four phases to systemically achieve this objective: (1) optimizing grout formulation, (2 and 3) evaluation of small scale laboratory samples of GERCC, and (4) conducting a field trial. This paper focuses on the final phase, a field trial conducted with ASI contractors at the Duck River Dam site located in Alabama. The results show that the adequate freeze thaw resistance can be attained by air entraining GERCC, but the results are very sensitive to the distribution of the grout through the RCC and adequate performance requires significant internal vibration
Optimization of Air Entrained Grout Enriched Roller Compacted Concrete for Improving Freeze-Thaw Resistance of Hydraulic Structures
Roller compacted concrete (RCC) is frequently used to construct gravity dams, stepped spillways, and to armor earthen embankments for passing extreme floods. Early experience on RCC dam applications in the 1980s showed a tendency for seepage to develop along the lift lines. Therefore, RCC dam designers started including an upstream facing system as a watertight barrier. An alternative facing material that has been used extensively overseas and is starting to gain more widespread acceptance in the United States is Grout Enriched RCC (GERCC). The grout enriched method of face construction has been shown to be less expensive than other facing options, particularly on larger dam projects. However, in the United States, the use of GERCC technology has been fairly limited, primarily due to concern over the material’s freeze-thaw resistance. Achieving cost-effective GERCC air entrainment and consolidation can significantly advance the competitiveness of RCC versus other alternatives. The objective of this project is to develop a grout formulation and construction technique that allows the production of air entrained GERCC. The study includes four phases to systemically achieve this objective: (1) optimizing grout formulation including type and dosage of chemical admixtures, (2) evaluation of small scale laboratory samples of RCC and grout combined in a mixer, (3) evaluation of large scale laboratory samples of RCC and grout combined simulating field construction techniques, and (4) conducting a field trial. The results of Phases 1 and 2 (presented herein) show that when the grout and RCC are combined in a mixer, good freeze-thaw resistance can be achieved. Phases 3 and 4 are currently underway. Through additional research, the project team’s goal is to advance the use of GERCC and promote more cost effective and technically viable construction of gravity dams, stepped spillways, armored earthen embankments and other hydraulic structures in climates subject to freeze-thaw cycles
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