2016 Illuminating a Treasure: The Marian Library at the University of Dayton

The Marian Library was founded in 1943 to honor Mary, perpetuate her message and commemorate the contributions of the Society of Mary in the United States. It’s now the largest collection in the world of books and artifacts about the Mother of Christ and has attracted the top Marian scholars for study, research, collaboration, publishing and dialogue. In this piece, the Marian Library invites all to connect to the vision and fulfill the call of the University of Dayton\u27s Marianist founders to share the knowledge of Mary. It features an array of photos of Marian Library materials, along with comments from University of Dayton and Marian Library faculty, alumni and students

Recognition of Regional Water Table Patterns for Estimating Recharge Rates in Shallow Aquifers

We propose a new method for groundwater recharge rate estimation in regions with stream-aquifer interactions, at a linear scale on the order of 10 km and more. The method is based on visual identification and quantification of classically recognized water table contour patterns. Simple quantitative analysis of these patterns can be done manually from measurements on a map, or from more complex GIS data extraction and curve fitting. Recharge rate is then estimated from the groundwater table contour parameters, streambed gradients, and aquifer transmissivity using an analytical model for groundwater flow between parallel perennial streams. Recharge estimates were obtained in three regions (areas of 1500, 2200, and 3300 km2) using available water table maps produced by different methods at different times in the area of High Plains Aquifer in Nebraska. One region is located in the largely undeveloped Nebraska Sand Hills area, while the other two regions are located at a transition zone from Sand Hills to loess-covered area and include areas where groundwater is used for irrigation. Obtained recharge rates are consistent with other independent estimates. The approach is useful and robust diagnostic tool for preliminary estimates of recharge rates, evaluation of the quality of groundwater table maps, identification of priority areas for further aquifer characterization and expansion of groundwater monitoring networks prior to using more detailed methods. Includes supplemental materials

Spatially and Spectrally Resolved Observations of a Zebra Pattern in Solar Decimetric Radio Burst

We present the first interferometric observation of a zebra-pattern radio burst with simultaneous high spectral (~ 1 MHz) and high time (20 ms) resolution. The Frequency-Agile Solar Radiotelescope (FASR) Subsystem Testbed (FST) and the Owens Valley Solar Array (OVSA) were used in parallel to observe the X1.5 flare on 14 December 2006. By using OVSA to calibrate the FST the source position of the zebra pattern can be located on the solar disk. With the help of multi-wavelength observations and a nonlinear force-free field (NLFFF) extrapolation, the zebra source is explored in relation to the magnetic field configuration. New constraints are placed on the source size and position as a function of frequency and time. We conclude that the zebra burst is consistent with a double-plasma resonance (DPR) model in which the radio emission occurs in resonance layers where the upper hybrid frequency is harmonically related to the electron cyclotron frequency in a coronal magnetic loop.Comment: Accepted for publication in Ap

People-First Promotion: Rallying Library Workers during COVID-19 and Beyond

COVID-19 forced workers around the world to face the realities of closed buildings, precarious employment situations, and challenges to their well-being. This article will showcase how library workers’ resilience during COVID-19 depended on people, not buildings, and a people-first public relations strategy was employed to reveal that distinction. The authors, a team of librarians and communicators, share three pandemic-era communication stories developed to put people at the forefront of initiatives and messaging: a revamped marketing strategy for a research appointment service puts faces to the work and student support; the cancellation announcement of a beloved annual event reveals how the event takes months of planning by employees—some of whom were affected by university furloughs and layoffs; and blog posts and reports of the numbers and stories of the COVID-19 response place the focus on the workers who make it possible, despite the unpredictable circumstances. Future communication and marketing can be rethought and retooled to make services, collections, and programs worker-driven, instead of a product of the (empty) library

Prediction of Biome-Specific Potential Evapotranspiration in Mongolia under a Scarcity of Weather Data

We propose practical guidelines to predict biome-specific potential evapotranspiration (ETp) from the knowledge of grass-reference evapotranspiration (ET0) and a crop coefficient (Kc) in Mongolia. A paucity of land-based weather data hampers use of the Penman–Monteith equation (FAO-56 PM) based on the Food and Agriculture Organization (FAO) guidelines to predict daily ET0. We found that the application of the Hargreaves equation provides ET0 estimates very similar to those from the FAO-56 PM approach. The Kc value is tabulated only for crops in the FAO-56 guidelines but is unavailable for steppe grasslands. Therefore, we proposed a new crop coefficient, Kc adj defined by (a) net solar radiation in the Gobi Desert (Kc adjD) or (b) leaf area index in the steppe region (Kc adjS) in Mongolia. The mean annual ETp obtained using our approach was compared to that obtained by FAO-56 guidelines for forages (not steppe) based on tabulated Kc values in 41 locations in Mongolia. We found the differences are acceptable (RMSE of 0.40 mm d-1) in northern Mongolia under high vegetation cover but rather high (RMSE of 1.69 and 2.65 mm d-1) in central and southern Mongolia. The FAO aridity index (AI) is empirically related to the ETp/ET0 ratio. Approximately 80% and 54% reduction of ET0 was reported in the Gobi Desert and in the steppe locations, respectively. Our proposed Kc adj can be further improved by considering local weather data and plant phenological characteristics

2018 Illuminating a Treasure: The 75th Anniversary of the Marian Library at the University of Dayton

The Marian Library was founded in 1943 to honor Mary, perpetuate her message and commemorate the contributions of the Society of Mary in the United States. It’s now the largest collection in the world of books and artifacts about the Mother of Christ and has attracted the top Marian scholars for study, research, collaboration, publishing and dialogue. In this 75th-anniversary publication, the Marian Library invites all to connect to the vision and fulfill the call of the University of Dayton\u27s Marianist founders to share the knowledge of Mary. It features an array of photos of Marian Library materials, along with comments from University of Dayton and Marian Library faculty, alumni and students

A Proper Generalized Decomposition (PGD) approach to crack propagation in brittle materials: with application to random field material properties

Understanding the failure of brittle heterogeneous materials is essential in many applications. Heterogeneities in material properties are frequently modeled through random fields, which typically induces the need to solve finite element problems for a large number of realizations. In this context, we make use of reduced order modeling to solve these problems at an affordable computational cost. This paper proposes a reduced order modeling framework to predict crack propagation in brittle materials with random heterogeneities. The framework is based on a combination of the Proper Generalized Decomposition (PGD) method with Griffith’s global energy criterion. The PGD framework provides an explicit parametric solution for the physical response of the system. We illustrate that a non-intrusive sampling-based technique can be applied as a postprocessing operation on the explicit solution provided by PGD.We first validate the framework using a global energy approach on a deterministic two-dimensional linear elastic fracture mechanics benchmark. Subsequently, we apply the reduced order modeling approach to a stochastic fracture propagation problem

A Model of IceWedge Polygon Drainage in Changing Arctic Terrain

As ice wedge degradation and the inundation of polygonal troughs become increasingly common processes across the Arctic, lateral export of water from polygonal soils may represent an important mechanism for the mobilization of dissolved organic carbon and other solutes. However, drainage from ice wedge polygons is poorly understood. We constructed a model which uses cross-sectional flow nets to define flow paths of meltwater through the active layer of an inundated low-centered polygon towards the trough. The model includes the eects of evaporation and simulates the depletion of ponded water in the polygon center during the thaw season. In most simulations, we discovered a strong hydrodynamic edge eect: only a small fraction of the polygon volume near the rim area is flushed by the drainage at relatively high velocities, suggesting that nearly all advective transport of solutes, heat, and soil particles is confined to this zone. Estimates of characteristic drainage times from the polygon center are consistent with published field observations

A Model of IceWedge Polygon Drainage in Changing Arctic Terrain

As ice wedge degradation and the inundation of polygonal troughs become increasingly common processes across the Arctic, lateral export of water from polygonal soils may represent an important mechanism for the mobilization of dissolved organic carbon and other solutes. However, drainage from ice wedge polygons is poorly understood. We constructed a model which uses cross-sectional flow nets to define flow paths of meltwater through the active layer of an inundated low-centered polygon towards the trough. The model includes the eects of evaporation and simulates the depletion of ponded water in the polygon center during the thaw season. In most simulations, we discovered a strong hydrodynamic edge eect: only a small fraction of the polygon volume near the rim area is flushed by the drainage at relatively high velocities, suggesting that nearly all advective transport of solutes, heat, and soil particles is confined to this zone. Estimates of characteristic drainage times from the polygon center are consistent with published field observations