Investigating Initial Interactions Between Silver Nanoparticles and Wastewater

The use of nanoparticles (NPs) has increased exponentially in the last 15-20 years, especially in the consumer market. NPs are currently found in over 1800 commercial products, including cosmetics, clothing, packaging, and toys. As a result, NPs can enter the environment via wastewater (WW) streams, leading to new challenges in WW treatment. This study focuses on the initial fate of silver nanoparticles (AgNPs) in WW. The AgNP interaction including aggregation and dissolution in both synthetic and real WW were studied. Real WW was collected from the primary-clarifier, secondary-clarifier, and effluent WW streams at two local WW treatment plants (Westside and Noland) in Fayetteville, AR. In all cases, AgNPs had high rates of aggregation with salts and solids in real and synthetic WW (80.3%-99.8%). Of the non-aggregated AgNPs, there was no statistical difference in the concentration of Ag that passed through the nano (0.1 µm) and ionic (3 kDa) filters, indicating that either the AgNPs were small enough to pass through the ionic filter (\u3c27 Ag atoms), or most of the non-aggregated Ag was present as ionic species rather than NPs. This merits further research

A New Design Method for Vanadium Redox Batteries in Renewable Energy Systems

This study investigated the behavior of vanadium redox flow batteries (VRFBs), which are batteries capable of easily switching between charging and discharging modes, making them a suitable option for storing intermittent sources of alternative energies (solar, wind, etc). Since different sizes of the battery provide varying voltages, optimal parameters for a particular home are key for implementation. These parameters, specifically the cell and tank volumes of the battery that are capable of providing consistent on-load voltage, were determined using data from a 13 kW solar array and a medium-sized house. Charge/discharge current values were used to run a mathematical model that provided on-load voltage over time graphs based on parameter input values. Using this model, the optimal parameter values were found to be 11.5 L for the cell volume and 103.7 L for the tank volume, which maintenained the on-load voltage well above 0.80 V (10% of cell standard emf)

Mining Moodle to understand Student Behaviour

With 32 million users across approximately 3 million courses worldwide, Moodle has proven to be an immensely popular and important tool in education. One feature provided by Moodle is a rich source of information about student access to online material. While important, this information is presented in a raw format with little indication about how it might be used. In this paper, we examine Moodle viewing statistics from an Irish third-level institution. We examine correlations between these statistics and student results on degree and masters courses. We identify the circumstances where the correlation can help predict poor performance (and hence allow early intervention). In the analysis we find some interesting associations between student behaviour on Moodle and their final grade. Some of these associations reinforce beliefs the authors already had about Moodle usage, and some results were surprising

Assessing the economic damages of climate change: the role of investment versus consumption

To calculate the damages climate change will cause in the economy, it is important to differentiate consumption from investment. Gregory Casey, Stephie Fried, and Matthew Gibson write that without that distinction, existing methods downplay the effect of climate change on capital accumulation and economic growth. Their research shows that climate change will have a significant impact on aggregate economic outcomes in developed economies and that these impacts will be closely tied to the construction sector

CU Defense - Lightweight Cranial Protection and Low Altitude Parachute Systems

The Clemson family proudly embraces its school\u27s rich military heritage and students in every department regularly demonstrate patriotism and respect for our nation\u27s armed forces. Our multidisciplinary team of undergraduates has sought to study and improve currently used technology to give soldiers an advantage in the field. We currently have two active projects, as described below. Lightweight Cranial Protection Current standard-issue combat helmets weigh more and offer less protection than desired. Equipment weight reduction is a constant goal for the armed forces, and enhanced safety is always favored. With recent technological developments in the application of dilatants, or shear-thickening fluids (STF), it appears that a helmet\u27s design and construction can be improved. We intend to apply several STF compositions to selected ballistic fibers using multiple impregnation methods. The resulting fibers will be tested for variations in ballistic performance. Low Altitude Parachute System currently used parachutes are designed to inflate slowly to avoid injury on opening. As a result, there is a range of heights that are too low for current parachutes to behave effectively. Using past current research and simulation software, we intend to study the various shapes and sizes of parachutes used throughout history and design a parachute system that will be effective at these low altitudes. This research could lead to the development of products that vastly increase the quality of life and safety of military, law enforcement, and rescue operations

The Extragalactic Distance Scale without Cepheids IV

The Cepheid period-luminosity relation is the primary distance indicator used in most determinations of the Hubble constant. The tip of the red giant branch (TRGB) is an alternative basis. Using the new ANU SkyMapper Telescope, we calibrate the Tully Fisher relation in the I band. We find that the TRGB and Cepheid distance scales are consistent.Comment: ApJ in press 201

Ubiquitous learning architecture to enable learning path design across the cumulative learning continuum

The past twelve years have seen ubiquitous learning (u-learning) emerging as a new learning paradigm based on ubiquitous technology. By integrating a high level of mobility into the learning environment, u-learning enables learning not only through formal but also through informal and social learning modalities. This makes it suitable for lifelong learners that want to explore, identify and seize such learning opportunities, and to fully build upon these experiences. This paper presents a theoretical framework for designing personalized learning paths for lifelong learners, which supports contemporary pedagogical approaches that can promote the idea of a cumulative learning continuum from pedagogy through andragogy to heutagogy where lifelong learners progress in maturity and autonomy. The framework design builds on existing conceptual and process models for pedagogy-driven design of learning ecosystems. Based on this framework, we propose a system architecture that aims to provide personalized learning pathways using selected pedagogical strategies, and to integrate formal, informal and social training offerings using two well-known learning and development reference models; the 70:20:10 framework and the 3–33 model