Establishing National Ocean Service Priorities for Estuarine, Coastal, and Ocean Modeling: Capabilities, Gaps, and Preliminary Prioritization Factors

This report was developed to help establish National Ocean Service priorities and chart new directions for research and development of models for estuarine, coastal and ocean ecosystems based on user-driven requirements and supportive of sound coastal management, stewardship, and an ecosystem approach to management. (PDF contains 63 pages

Supporting Cross-Organizational Assimilation of IoT Innovation Exemplified by the ChainPORT Initiative

The chainPORT community of port authorities (PAs) around the world gave their commitment to collaborate. Many PAs developed Internet of Things (IoT) based solutions to increase their operational efficiency. Within its IT solutions workgroup, the challenge of supporting the diffusion and assimilation of these IoT innovations was adressed by creating a centralized communication platform for IoT solutions to allow inter-organizational knowledge exchange. We draw upon the knowledge gained by analyzing 24 solutions from 8 port authorities and present concepts on how the specific challenges in this setting were adressed and what principles guided the creation of the emerging IT artifact

The influence of encoding strategy on associative memory consolidation across wake and sleep

Sleep benefits memory consolidation. However, factors present at initial encoding may moderate this effect. Here, we examined the role that encoding strategy plays in subsequent memory consolidation during sleep. Eighty-nine participants encoded pairs of words using two different strategies. Each participant encoded half of the word pairs using an integrative visualization technique, where the two items were imagined in an integrated scene. The other half were encoded nonintegratively, with each word pair item visualized separately. Memory was tested before and after a period of nocturnal sleep ( N = 47) or daytime wake ( N = 42) via cued recall tests. Immediate memory performance was significantly better for word pairs encoded using the integrative strategy compared with the nonintegrative strategy ( P < 0.001). When looking at the change in recall across the delay, there was significantly less forgetting of integrated word pairs across a night of sleep compared with a day spent awake ( P < 0.001), with no significant difference in the nonintegrated pairs ( P = 0.19). This finding was driven by more forgetting of integrated compared with not-integrated pairs across the wake delay ( P < 0.001), whereas forgetting was equivalent across the sleep delay ( P = 0.26). Together, these results show that the strategy engaged in during encoding impacts both the immediate retention of memories and their subsequent consolidation across sleep and wake intervals

Understanding the sharing economy and its implication on sustainability in smart cities

Akande, A., Cabral, P., & Casteleyn, S. (2020). Understanding the sharing economy and its implication on sustainability in smart cities. Journal of Cleaner Production, 277, 1-11. [124077]. https://doi.org/10.1016/j.jclepro.2020.124077The purpose of this article is to evaluate the main drivers of the sharing economy through an exhaustive weighting and meta-analysis of previous relevant quantitative research articles, obtained using a systematic literature review methodology. The authors analysed 22 quantitative studies from 2008 through. Out of the 249 extracted relationships (independent – dependent variable), the paper identifies the “best” predictors used in theoretical models to study the sharing economy. These include: attitude on intention to share, perceived behavioural control on intention to share, subjective norm on intention to share, economic benefit on attitude, and perceived risk on attitude. Geographically, Germany and the United States of America were found to be the nations with the highest number of respondents. Temporally, an increasing trend in the number of articles on the sharing economy and respondents was observed. The consolidation of the drivers of the sharing economy provides a solid theoretical foundation for the research community to explore existing hypotheses further and test new hypotheses in emerging contexts of the sharing economy. Given the different conceptual theories that have been used to study the sharing economy and their application to different contexts, this study presents the first attempt at advancing knowledge by quantitatively synthesizing findings presented in previous literature.publishersversionpublishe

Advanced gas atomization production of oxide dispersion strengthened (ODS) Ni-base superalloys through process and solidification control

A novel gas atomization reaction synthesis (GARS) method was utilized to produce precursor Ni-Cr-Y-Ti powder with a surface oxide and an internal rare earth (RE)-containing intermetallic. Although Al is necessary for industrial superalloy production, the Ni-Cr base alloy system was selected as a simplified system more amenable to characterization. This was done in an effort to better study the effects of processing parameters. Consolidation and heat-treatment were performed to promote the exchange of oxygen from the surface oxide to the RE intermetallic to form nanometric oxide dispersoids. Alloy selection was aided by an internal oxidation and serial grinding experiment that found that Hf-containing alloys may form more stable dispersoids than Ti-containing alloys, but the Hf-containing system exhibited five different oxide phases and two different intermetallics compared to the two oxide phases and one intermetallic in the Ti-containing alloys. Since the simpler Ti-containing system was easier to characterize, and make observations on the effects of processing parameters, the Ti-containing system was used for experimental atomization trials. An internal oxidation model was used to predict the heat treatment times necessary for dispersoid formation as a function of powder size and temperature. A new high-pressure gas atomization (HPGA) nozzle was developed with the aim of promoting fine powder production at scales similar to that of the high gas-flow and melt-flow of industrial atomizers. The atomization nozzle was characterized using schlieren imaging and aspiration pressure testing to determine the optimum melt delivery tip geometry and atomization pressure to promote enhanced secondary atomization mechanisms. Six atomization trials were performed to investigate the effects of gas atomization pressure and reactive-gas concentration on the particle size distribution (PSD). Also, the effect on the rapidly solidified microstructure (as a function of powder size) was investigated as a function of reactive-gas composition and bulk alloy composition. The results indicate that the pulsation mechanism and optimum PSDs reported in the literature were not observed. Also, it was determined that reactive gas may marginally improve the PSD, but further experiments are required. The oxygen content in the gas was also not found to be detrimental to the microstructure (i.e., did not catalyze nucleation), but may have removed potent catalytic nucleation sites, although not enough to significantly alter the microstructure. Overall, the downstream injection of oxygen was not found to significantly affect either the PSD or undercooling (as inferred from microstructure and XRD observations), but injection further upstream, including in the gas atomization nozzle, remains to be investigated

Volume change behavior of clay soils and the effect on discrete fractures

This study examines the behavior of subsurface fractures in fine-grained soil such as clays in response to changing environmental conditions. Fractures serve as conduits for moisture transfer, which can lead to substantial shrinking and swelling of the surrounding fracture boundary soils. These volume changes, in turn, affect fracture geometry and moisture transmission rates. A new predictive model, termed the \u27Fracture Volume Change Model\u27 (FVC Model), has been developed to relate moisture transfer, soil volume change and associated changes in fracture aperture. The model assumes a discrete horizontal fracture in a laterally-infinite, saturated, expansive clay with rigid, outer no-flow boundaries and an inner flexible yielding boundary along the fracture. The FVC Model is based on the one-dimensional diffusion equation, which is solved analytically for both constant moisture and constant flux fracture boundary conditions. Changes in fracture aperture are predicted assuming normal shrinkage and either isotropic or anisotropic volume change. The model is expandable to bulk scale analysis of geologic formations with multiple stacked fractures. The model was validated and calibrated in the laboratory using a custom fabricated horizontal infiltrometer device. Tests were conducted on a problematic clay soil from Fairfax County, Virginia, belonging to the southern montmorillonite facies of the Potomac Formation. Moisture content was varied from 17% to 33% by forcing air through an artificially created discrete fracture. Moisture changes in the fracture boundary soils caused the effective fracture aperture to fluctuate from near closure to 0.031 in. (0.79 mm). Upon application of excess moisture, it was riot possible to effect full closure of the fracture. Moisture values predicted with the FVC Model demonstrated good agreement with the laboratory data, deviating 6% on average. Predictions of fracture aperture were generally overestimated. The model confirmed the dominance of internal hydraulic properties of the soil matrix over evaporation or infiltration mechanisms. The model was also used to predict soil desiccation rates for an environmental remediation project in expansive clay in Santa Clara, California. Model application to agriculture, geotechnical engineering, and resource geology is also described

Strategic enterprise management systems : tools for the 21st century

https://egrove.olemiss.edu/aicpa_guides/1228/thumbnail.jp

Opinion Polarization by Learning from Social Feedback

We explore a new mechanism to explain polarization phenomena in opinion dynamics in which agents evaluate alternative views on the basis of the social feedback obtained on expressing them. High support of the favored opinion in the social environment, is treated as a positive feedback which reinforces the value associated to this opinion. In connected networks of sufficiently high modularity, different groups of agents can form strong convictions of competing opinions. Linking the social feedback process to standard equilibrium concepts we analytically characterize sufficient conditions for the stability of bi-polarization. While previous models have emphasized the polarization effects of deliberative argument-based communication, our model highlights an affective experience-based route to polarization, without assumptions about negative influence or bounded confidence.Comment: Presented at the Social Simulation Conference (Dublin 2017