In this work we examine the dispersion of conservative tracers (bromide and fluorescein) in an experimentally constructed three-dimensional dual-porosity porous medium, and in the absence of adjustable parameters. The medium is highly heterogeneous (σ2 Y = 5.7), and consists of spherical, low-hydraulic-conductivity inclusions embedded in a high-hydraulic-conductivity matrix. The bi-modal...
Study of the eolian fraction of late Quaternary sediments from the tropical Atlantic reveals that two modes of long-term climate variability have existed in tropical Africa during the last 150,000 yr. Tropical northwest Africa (i.e., the southwestern Sahara and Sahel) was driest during glaciations and stades, but wetter than at...
Enacted in 1966 and effective July 4, 1967, the Freedom of Information Act (FOIA) gives people, both citizens and non-citizens, the right to request access to federal executive branch agency records. According to FOIA’s website, provided by the United States Department of Justice, FOIA “is a law that gives you...
The HIV pandemic continues to impose enormous morbidity, mortality and economic burdens across the globe. Simultaneously, innovations in antiretroviral therapy, diagnostic approaches and vaccine development are providing novel tools for treatment-as-prevention and prophylaxis. We developed a mathematical model to evaluate the added benefit of an HIV vaccine in the context...
Load-displacement characteristics and failure modes of metal-plateconnected wood truss joints are presented. Tension splice, heel, and web at the bottom chord joints are fabricated using southern pine (SP) no. 2 lumber and 20-gage punched metal plates. These joints are tested with a newly developed testing appratus that allows the testing...
PN junctions in nanoscale materials are of interest for a range of technologies including photodetectors, solar cells, and light-emitting diodes. However, Schottky barriers at the interface between metal contacts and the nanomaterial are often unavoidable. The effect of metal-semiconductor interfaces on the behavior of nanoscale diodes must be understood, both...
Ion channels play a key role in regulating cell behavior and in electrical signaling. In these settings, polar and charged functional groups, as well as protein response, compensate for dehydration in an ion-dependent way, giving rise to the ion selective transport critical to the operation of cells. Dehydration, though, yields...
The main research goal for this study was to describe how investment into the Hubs has influenced local STEM communities; that is, how STEM Hubs have begun to create opportunities for partnerships, collaboration, connected programing, improved program development or delivery, or improved communication within and outside the STEM teaching and...
Most readers are familiar with (and indeed weary of) the long-running serials crisis: budgets have stagnated as the cost of serials for STEM disciplines continues to rise (Bosch & Henderson, 2016). These circumstances force libraries to cancel journals, affecting researchers’ instant access to articles. Nearly two decades ago, Mobley (1998)...