Heat and water transport in soils and across the soil-atmosphere interface: 2. Numerical analysis

In an accompanying paper, we presented an overview of a wide variety of modeling concepts, varying in complexity, used to describe evaporation from soil. Using theoretical analyses, we explained the simplifications and parameterizations in the different approaches. In this paper, we numerically evaluate the consequences of these simplifications and parameterizations. Two sets of simulations were performed. The first set investigates lateral variations in vertical fluxes, which emerge from both homogeneous and heterogeneous porous media, and their importance to capturing evaporation behavior. When evaporation decreases from parts of the heterogeneous soil surface, lateral flow and transport processes in the free flow and in the porous medium generate feedbacks that enhance evaporation from wet surface areas. In the second set of simulations, we assume that the vertical fluxes do not vary considerably in the simulation domain and represent the system using one-dimensional models which also consider dynamic forcing of the evaporation process, for example, due to diurnal variations in net radiation. Simulated evaporation fluxes subjected to dynamic forcing differed considerably between model concepts depending on how vapor transport in the air phase and the interaction at the interface between the free flow and porous medium were represented or parameterized. However, simulated cumulative evaporation losses from initially wet soil profiles were very similar between model concepts and mainly controlled by the desorptivity, Sevap, of the porous medium, which depends mainly on the liquid flow properties of the porous medium

The Visual Memory of Protest: Introduction

this is an introduction to the background, aims, and contents of the collection of essays called The Visual Memory of Protes

Heat and Water Transport in Soils and across the Soil-Atmosphere Interface: Comparison of Model Concepts.

Evaporation from the soil surface represents a water flow and transport process in a porous medium that is coupled with a free air flow and with heat fluxes in the system. We give an overview of different model concepts that are used to describe this process. These range from non-isothermal two-phase flow two-component transport in the porous medium that is coupled with one-phase flow two-component transport in the free air to isothermal water flow in the porous with upper boundary conditions defined by a potential evaporation flux when available energy and transfer to the free air flow are limiting or by a critical threshold water pressure when soil water availability is limiting. The latter approach corresponds with the classical Richards equation with mixed boundary conditions. We formulated the different equations and identified assumptions behind simplified forms. Conditions for which lateral and up and downward air flow in the porous medium and vapor diffusion in the pore space play an important role were identified using simulations for a set of scenarios. When comparing cumulative evaporation fluxes from initially wet soil profiles, only small differences between the different models were found. The effect of vapor flow in the porous medium on cumulative evaporation could be evaluated using the desorptivity, Sevap, which represents a weighted average of liquid and vapor diffusivity over the range of soil water contents between the soil surface water content and the initial soil water content. Vapor flow influences the shape of the moisture front close to the soil surface. Simulated evaporation fluxes under dynamic forcing, e.g. due to diurnal variations in net radiation, differed considerably between the models. Experimental methods that allow monitoring of diurnal evaporation fluxes are therefore essential for model discrimination and parameterization

Developing Global Sociotechnical Competency Through Humanitarian Engineering: A Comparison of In-Person and Virtual International Project Experiences

In response to the COVID-19 pandemic, a group of engineering educators in the United States and Colombia designed and led a two-week virtual “field session” for engineering undergraduate students that aimed at achieving the same educational outcomes as those from the previous in-country field session. Our NSF PIRE funded Responsible Mining, Resilient Communities (RMRC) project uses multi-country, interinstitutional, and interdisciplinary collaboration to train U.S. engineering students to co-design socially responsible and sustainable artisanal and small-scale gold mining (ASGM) systems with mining communities and engineers in Latin America. Drawing from pre- and post-field session student interviews, essays, and survey responses, this article analyzes how the virtual 2020 field session and the in-person 2019 session influenced students’ global sociotechnical competency. We offer a conceptualization of global sociotechnical competency that synthesizes notions of global engineering competency with theories of socially responsible engineering that emphasize problem definition and solution with underserved communities. Our research suggests that whereas many educators raised concerns about the efficacy of virtual formats for student learning and professional development, the 2020 session was effective for enhancing students’ abilities to identify stakeholders and methods to engage them, as well as for using sociotechnical coordination while engaging in problem definition. While the small number of student participants cautions against making broad generalizations, the virtual (2020) and in-person (2019) students experienced similar increases in self-reported empathizing practices with the intended users of their designs; a desire and ability to integrate social concerns into their design; a desire and ability to work with people from different backgrounds; and self-efficacy in engineering. The virtual students were less likely, however, than their in-person counterparts to desire a humanitarian engineering career. While the small number of students raises questions for extrapolating the results of our findings, our research does signal fruitful areas of future research for making humanitarian engineering projects more equitable and effective, even in virtual settings

Scarcity in Visual Memory: Creating a Mural of Sylvia Pankhurst

This chapter looks at the “premediation” (Erll & Rigney, 2009) of a mural of the early 20th-century activist Sylvia Pankhurst and considers a number of photographs that it remediates, asking the question: How did these images end up here? The chapter follows the images in relation to broader characteristics of Pankhurst’s remembrance, exploring the long and often complicated pathways they take to become carriers of cultural memory. This exploration reveals the many different forms of political or aesthetic attachment behind the mural, which themselves are shaped by institutional, financial, or technological constraints and possibilities, and demonstrates that even in a culture of “post-scarcity” (Hoskins, 2018) and supposed imagistic abundance the visual memory of activism is still governed by scarcity

Magnetron sputtering fabrication of α-Al2O3:Cr powders and their T thermoluminescence properties

The authors gratefully acknowledge the financial support for this work from research grant ERA.NET RUS Plus Nr.609556.For many years doped α-Al2O3 has attracted interest as a dosimeter for personal, environment monitoring and food control. The alumina single crystal growth is a difficult process; however, materials in form of powders, ceramics and coating are possible to obtain. In this study for the first time Cr doped α-Al2O3 powders were prepared by DC reactive magnetron sputtering followed by milling and oxidation. The morphology and phase analysis was performed; content of residual impurities was determined and thermostimulated glow curves were measured after different x-ray irradiation times (radiation doses). The prepared powder shows the dosimetry properties up to 20 kGy dose.ERA.NET RUS Plus Nr.609556; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Quantifying maternal investment in mammals using allometry

Maternal investment influences the survival and reproduction of both mothers and their progeny and plays a crucial role in understanding individuals’ life-history and population ecology. To reveal the complex mechanisms associated with reproduction and investment, it is necessary to examine variations in maternal investment across species. Comparisons across species call for a standardised method to quantify maternal investment, which remained to be developed. This paper addresses this limitation by introducing the maternal investment metric – MI – for mammalian species, established through the allometric scaling of the litter mass at weaning age by the adult mass and investment duration (i.e. gestation + lactation duration) of a species. Using a database encompassing hundreds of mammalian species, we show that the metric is not highly sensitive to the regression method used to fit the allometric relationship or to the proxy used for adult body mass. The comparison of the maternal investment metric between mammalian subclasses and orders reveals strong differences across taxa. For example, our metric confirms that Eutheria have a higher maternal investment than Metatheria. We discuss how further research could use the maternal investment metric as a valuable tool to understand variation in reproductive strategies

Evaluation of a national lung cancer symptom awareness campaign in Wales

Background Lung cancer is the leading cause of cancer mortality in Wales. We conducted a before- and after- study to evaluate the impact of a four-week mass-media campaign on awareness, presentation behaviour and lung cancer outcomes. Methods Population-representative samples were surveyed for cough symptom recall/recognition and worry about wasting doctors’ time pre-campaign (June 2016; n = 1001) and post-campaign (September 2016; n = 1013). GP cough symptom visits, urgent suspected cancer (USC) referrals, GP-ordered radiology, new lung cancer diagnoses and stage at diagnosis were compared using routine data during the campaign (July–August 2016) and corresponding control (July–August 2015) periods. Results Increased cough symptom recall (p < 0.001), recognition (p < 0.001) and decreased worry (p < 0.001) were observed. GP visits for cough increased by 29% in the target 50+ age-group during the campaign (p < 0.001) and GP-ordered chest X-rays increased by 23% (p < 0.001). There was no statistically significant change in USC referrals (p = 0.82), new (p = 0.70) or early stage (p = 0.27) diagnoses, or in routes to diagnosis. Conclusions Symptom awareness, presentation and GP-ordered chest X-rays increased during the campaign but did not translate into increased USC referrals or clinical outcomes changes. Short campaign duration and follow-up, and the small number of new lung cancer cases observed may have hampered detection effects