Welker, A.L., Sample-Lord, K.M., Yost, J.R. (2017). Weaving entrepreneurially minded learning throughout a civil engineering curriculum, ASEE Annual Conference and Exposition, Conference Proceedings, 2017-June
The Kern Family Foundation has provided funding to Villanova University to implement the Kern Entrepreneurial Engineering Network (KEEN) initiative. This nearly decade-old initiative seeks to instill concepts of Entrepreneurially Minded Learning (EML) into the undergraduate engineering curriculum. EML emphasizes educating the "whole engineer" by supplementing traditional engineering theory with nontechnical concepts related to curiosity, connections, and creating value (the three Cs). "Curiosity" encourages students to investigate and question the society that surrounds them within the context of the technical material they are learning in class. In short, it encourages students to be problem seekers and definers as opposed to just problem solvers. Students are then ready to make "Connections" to synthesize new and old knowledge to create innovative solutions to problems. Lastly, "Creating Value" is about improving society and quality of life by creatively applying their engineering skills. It is important to note that this approach to education is not about creating start-ups or commercial products, rather, it is a way to foster inventive thinking. Nearly half of the faculty members in the Civil and Environmental Engineering (CEE) department have participated in KEEN workshops that focus on implementation of EML in their respective courses. These faculty have woven EML throughout the CEE curriculum to ensure that students have assignments that relate to the three Cs every semester from freshman to senior year. These assignments are also used to fulfill ABET and ASCE Civil Engineering Program Criteria. This paper will describe class assignments for courses with EML content, extra- and co-curricular EML activities, the relationship between EML and ABET criterion 3 and the ASCE Civil Engineering Program Criteria, and provide thoughts on linking EML to educational assessment. © American Society for Engineering Education, 2017.
Smith, V.B., Mohrig, D. Geomorphic signature of a dammed Sandy River: The lower Trinity River downstream of Livingston Dam in Texas, USA. Geomorphology, 297, pp. 122-136.
Reservoirs behind dams act as deposition sites for much of the sediment being transported by rivers. As a result, the downstream river flow can be well below the transport capacity for bed-material. This promotes bed erosion and other geomorphic changes over some length of river located immediately downstream from a dam. These adjustments have been characterized for the Trinity River, TX, downstream of Livingston Dam. Field measurements and results from a 1D numerical model define a 50–60 river kilometer segment of river undergoing bed erosion as the transport capacity for bed material is reestablished. Consequences of this erosion include lowering of the channel bed, reduction in the sediment volume of channel bars, coarsening of sediment on bar tops, steepening of channel banks, and reduction in lateral migration rates of river bends. Repeat surveys of the river long profile reveals that 40 yr of dam closure has produced up to seven meters of channel-bottom incision downstream of the dam, transforming an initially linear profile into a convex-up long profile. The model output matches this observed change, providing confidence that calculated estimates for spatial and temporal changes in bed-material sediment flux can be used to explore the long-term signature of dam influence on the geomorphology of a sand-bed channel. Measurements of channel geometry, profile, lateral migration, and grain size of the lower Trinity River with distance downstream define both the trend and expected variability about the trend associated with the disruption to the bed-material load.
Sample-Lord, K.M., Shackelford, C.D., Membrane behavior of unsaturated sodium bentonite, Journal of Geotechnical and Geoenvironmental Engineering, 144(1), art. no. 04017102.
Chemical containment barriers comprising sodium bentonite (Na-bentonite) have been shown to exhibit semipermeable membrane behavior under saturated conditions. Since membrane behavior results in restricted migration of aqueous-phase chemicals (solutes), the existence of membrane behavior in bentonite-based barriers can significantly improve the containment function of the barriers. However, some bentonite-based barriers exist under unsaturated conditions, and the extent to which the degree of saturation, S, of the barrier affects the existence and magnitude of membrane behavior has not been evaluated heretofore. Accordingly, the membrane efficiency coefficient, ω, of Na-bentonite was measured in the laboratory at constant S in response to applied differences in potassium chloride (KCl) concentrations under closed-system conditions. The results indicated that, for a given S, ω decreased as the source concentration of KCl (Cot) increased, which is consistent with previous studies based on S = 1.0. However, for a given Cot, ω increased with decreasing S, as expected on the basis that a reduction in S corresponds to a reduction in the water-filled pore space accessible for solute migration. Overall, ω ranged from 0.31 at S = 1.0 with Cot = 50 mM KCl to 0.75 at S = 0.79 for Cot = 20 mM KCl. Although the range in S that was evaluated was limited by the testing conditions, which resulted in test durations ranging from 232 to 335 days, the results of this study provide the first quantitative evidence illustrating the effect of S on ω for Na-bentonite.
Sample-Lord, K.M., Shackelford, C.D, Apparatus for measuring coupled membrane and diffusion behavior of unsaturated sodium bentonite, Vadose Zone Journal , 16 ( 9 ) 16 p.
Sodium bentonite (Na-bentonite) has been shown to exhibit semipermeable membrane behavior—the ability to selectively restrict the migration of dissolved chemical species through the pores of the clay. However, experimental research to date has focused on the membrane behavior of Na-bentonite almost exclusively under water-saturated conditions (i.e., degree of saturation S = 1), even though membrane behavior under unsaturated conditions is expected to be more significant. Further, the limited number of studies that have been performed to evaluate membrane behavior in unsaturated soils have used only open systems to quantify membrane efficiency (w), despite the testing advantages of using closed systems (e.g., more accurate measurement of w, easier control of boundary conditions). Thus, a closed-system testing apparatus capable of measuring coupled membrane and diffusion behavior in unsaturated Na-bentonite was developed and then used to measure w and salt diffusion in Na-bentonite with S of 0.84 and 1.0. For a source solution (concentration difference) of 20 mM KCl, w increased from 0.61 to 0.71 as S decreased from 1.0 to 0.84, which is consistent with the current conceptual understanding of membrane behavior and trends in the literature. In contrast, the effective diffusion coefficient for Cl− was essentially the same (i.e., ~1.8 × 10−10m2s−1) for both specimens due to the small difference in S. The development of the testing apparatus advances the state of the art for laboratory measurement of coupled membrane and diffusion behavior in unsaturated clays commonly used as chemical containment barriers.
Traver, R.G., Ebrahimian, A., Dynamic design of green stormwater infrastructure, Frontiers of Environmental Science and Engineering, 11 ( 4 ) , art. no. 15
This paper compares ongoing research results on hydrologic performance to common design and crediting criteria, and recommends a change in direction from a static to a dynamic perspective to fully credit the performance of green infrastructure. Examples used in this article are primarily stormwater control measures built for research on the campus of Villanova University [1,2]. Evidence is presented demonstrating that the common practice of crediting water volume based on soil and surface storage underestimates the performance potential, and suggests that the profession move to a more dynamic approach that incorporates exfiltration and evapotranspiration. The framework for a dynamic approach is discussed, with a view to broaden our design focus by including climate, configuration and the soil surroundings. The substance of this work was presented as a keynote speech at the 2016 international Low Impact Development Conference in Beijing China . © 2017, Higher Education Press and Springer-Verlag GmbH Germany.