BlogForever D5.2: Implementation of Case Studies

This document presents the internal and external testing results for the BlogForever case studies. The evaluation of the BlogForever implementation process is tabulated under the most relevant themes and aspects obtained within the testing processes. The case studies provide relevant feedback for the sustainability of the platform in terms of potential users’ needs and relevant information on the possible long term impact

Liquefaction Evaluations at the Savannah River Site. A Case History

Over the past decade, liquefaction assessments have been performed for many existing and planned critical facilities at the Department of Energy’s Savannah River Site (SRS). The assessments incorporated site-specific Cyclic Resistance Ratio (CRR) and Ks with the use of the cone penetration test (CPT). The SRS-specific CRR and Ks were developed from laboratory testing of carefully collected samples. Test results show SRS soils have increased liquefaction resistance of two to three times when compared to standard literature for Holocene-age deposits. This increase in strength can be attributed to many factors such as aging and overconsolidation. The purpose of this paper is to discuss liquefaction methodologies used at the SRS. Specifically, 1) use of the CPT and correlations of CPT-derived results with that of high-quality undisturbed samples; 2) aging; and 3) Ks vertical confining stress factor

Seismic Stability Analysis of a High Earth and Rockfill Dam

Accumulation of knowledge on earthquake activity in California has lead to stronger ground motions being postulated for the evaluation of the seismic stability of dams. A recent regional seismicity study for a 555 ft high earth and rockfill dam in central California lead to a ground motion with peak ground acceleration (PGA) of 0.50g originating in a local fault system 3 miles from the dam site. This PGA is more than 6 times higher than the PGA=0.08g value originally adopted when the Dam was analyzed for seismic stability 20 years ago. Thus, as part of FERC Part 12 evaluation requirements, the seismic stability of the Dam was re-evaluated using the updated ground motion and state-of-the-practice technology. This paper presents the analysis procedures and the results

Agronomic evaluation of a Colombian passion fruit (Passiflora edulis Sims) germplasm collection

ArticlePassion fruit (Passiflora edulis Sims) is one of the most promissory crops in Colombia with approximately 7,400 ha cultivated, an average production of 89,000 t and an average yield of 15 t ha-1. However, low yields as well as harvest problems including fruit quality, generate important losses, mainly due to lack of improved cultivars with particular characteristics for each market (fresh consumption, agroindustry) and specific adaptations to biotic and abiotic stress factors in producer areas. Therefore, as a pre-breeding phase, this study aimed at characterizing preliminary the production and physiochemical characteristics of 60 passion fruit germplasm accessions maintained in Corporación Colombiana de Investigación Agropecuaria (AGROSAVIA). We cultivated these accessions in the field for 22 months between 2014 and 2015, measuring 17 variables associated to both yield production and fruit quality. We analysed data using phenetic and multivariate methods to establish levels of genetic diversity. Additionally, we constructed a selection index (SI) with the most informative variables to select individuals according to fruit weight, shape and colour, as well as juice percentage. Results of genetic grouping and principal components showed a broad genetic diversity across the working collection, without any population substructure. Fruit volume, pulp and seed weight were the variables that explained 80% of the phenotypic variation. Finally, we identified 30 promissory accessions as parental for the first cycle of recurrent selection using the SI. We conclude that this core collection represents the diversity included in the working collection with promissory accessions to initiate an intra-population recurrent selection program

Protected land enhances the survival of native aquatic macrophytes and limits invasive species spread in the Panama Canal

1. This study examined whether protected land in a tropical reservoir's catchment can promote the survival of native aquatic plants (macrophytes) and limit the spread of invasive alien plant species (macrophyte IAS), which can threaten native wildlife and require expensive remediation. As the number of tropical river dams is expected to increase in the coming decades to meet societal demands, it is crucial to explore solutions for preserving aquatic biodiversity. 2. The study used a before–after–control–intervention design, based on monitoring data and long-term sedimentological, climatic and ecological records from both lake and river zones adjacent to protected and unprotected lands around the 100-year-old Gatun Lake in the Panama Canal, Panama. The research examined the impact of impoundment and the invasion of Pontederia crassipes (water hyacinth) and Hydrilla verticillata (water thyme) on native macrophyte communities and environmental variables. 3. Lake zones adjacent to protected lands had lower nutrient concentrations, greater variations in water depth profiles and reduced fluctuations in water chemistry than lake zones outside areas of land protection. In addition, the results showed that whereas zones adjacent to unprotected land became dominated by macrophyte IAS, lake zones adjacent to protected areas were more resilient to the spread of macrophyte IAS and were able to maintain viable populations of native pre-dam species for >100 years. 4. This study indicates that protecting land adjacent to tropical reservoirs could be a cost-effective solution for preserving aquatic macrophyte biodiversity by retaining nutrients, stabilizing water chemistry, providing habitat heterogeneity and protecting native vegetation, while still supporting terrestrial conservation goals. These findings could aid in planning measures for the hundreds of proposed dam projects across lowland tropical areas and provide new insights into best practices for enhancing river ecosystem resilience

GEOTECHNICAL ENGINEERING AT THE SAVANNAH RIVER SITE AND BECHTEL

The authors describe two aspects of geotechnical engineering; site characterization utilizing the CPT and recognition of aging as a factor affecting soil properties. These methods were pioneered by Professor Schmertmann and are practiced by the Bechtel Corporation in general and at the Savannah River Site in South Carolina, in particular. This paper describes a general subsurface exploration approach that we have developed over the years. It consists of ''phasing'' the investigation, employing the principles of the observational method suggested by Peck (1969) and others. In doing so, we have found that the recommendations proposed by Sowers in terms of borehole spacing and exploration cost, are reasonable for developing an investigation program, recognizing that through continuous review the final investigation program will evolve. At the SRS shallow subsurface soils are of Eocene and Miocene age. It was recognized that the age of these deposits would have a marked effect on their cyclic resistance. A field investigation and laboratory testing program was devised to measure and account for aging as it relates to the cyclic resistance of the site soils. Recently, a panel of experts (Youd et al., 2001) has made recommendations regarding the liquefaction assessment of soils. This paper will address some of those recommendations in the context of re-assessing the liquefaction resistance of the soils at the SRS. It will be shown that, indeed, aging plays a major role in the cyclic resistance of the soils at the SRS, and that aging should be accounted for in liquefaction potential assessments for soils older than Holocene age

BlogForever D5.3: User Questionnaires and Reports

This report presents the feedback gathered from third party users during the BlogForever Case Studies. Therefore, the research framework is defined and the case studies results are presented, followed by a summary of conclusions and remarks

High temperature ferromagnetism of Li-doped vanadium oxide nanotubes

The nature of a puzzling high temperature ferromagnetism of doped mixed-valent vanadium oxide nanotubes reported earlier by Krusin-Elbaum et al., Nature 431 (2004) 672, has been addressed by static magnetization, muon spin relaxation, nuclear magnetic and electron spin resonance spectroscopy techniques. A precise control of the charge doping was achieved by electrochemical Li intercalation. We find that it provides excess electrons, thereby increasing the number of interacting magnetic vanadium sites, and, at a certain doping level, yields a ferromagnetic-like response persisting up to room temperature. Thus we confirm the surprising previous results on the samples prepared by a completely different intercalation method. Moreover our spectroscopic data provide first ample evidence for the bulk nature of the effect. In particular, they enable a conclusion that the Li nucleates superparamagnetic nanosize spin clusters around the intercalation site which are responsible for the unusual high temperature ferromagnetism of vanadium oxide nanotubes.Comment: with some amendments published in Europhysics Letters (EPL) 88 (2009) 57002; http://epljournal.edpsciences.or

Ubiquity of optical activity in planar metamaterial scatterers

Recently it was discovered that periodic lattices of metamaterial scatterers show optical activity, even if the scatterers or lattice show no 2D or 3D chirality, if the illumination breaks symmetry. In this Letter we demonstrate that such `pseudo-chirality' is intrinsic to any single planar metamaterial scatterer and in fact has a well-defined value at a universal bound. We argue that in any circuit model, a nonzero electric and magnetic polarizability derived from a single resonance automatically imply strong bianisotropy, i.e., magneto-electric cross polarizability at the universal bound set by energy conservation. We confirm our claim by extracting polarizability tensors and cross sections for handed excitation from transmission measurements on near-infrared split ring arrays, and electrodynamic simulations for diverse metamaterial scatterers.Comment: 5 pages, 4 figure

Virtual environment to co-create digital educational resources in higher education

En el presente artículo se presenta una aproximación a un ambiente virtual de aprendizaje, el cual por medio de una plataforma permite la cocreación de recursos educativos digitales para instituciones de educación superior en Colombia. Esta propuesta resulta de un proceso de investigación orientado hacia la aplicación de metodologías y estrategias de enseñanza-aprendizaje efectivas para ambientes universitarios. Asimismo, se aborda la cocreación como un método significativo para el diseño de contenidos de aprendizaje, en razón a la relación representativa entre los actores involucrados en la producción del recurso (usuario-diseñador), y el conocimiento teórico y experiencial que tiene cada uno y que se pone en uso en un ambiente virtual. El objetivo central del estudio es «implementar un modelo para la cocreación y producción de contenidos educativos abiertos mediante el uso de una plataforma virtual», el cual se circunscribe en la perspectiva cualitativa, desde el enfoque metodológico hermenéutico. Como resultados y conclusiones se expone que el concepto de cocreación abre múltiples posibilidades de gestar procesos enriquecidos, liderados y generados tanto por el docente como por los estudiantes. Es una acción de doble vía donde ambos perfiles proponen, producen y distribuyen con el fin de generar recursos educativos y compartir interés y conocimiento en comúnThis article presents an approach of a virtual learning environment, which through an online platform allows the co-creation of digital educational resources for higher education in Colombia. This proposal results from a research process oriented to the application of effective teaching-learning methodologies and strategies for university environments. Co-creation is approached as a significant method for the design of learning contents, due to the representative relationship among the actors involved in the resources production (user-designer), and the theoretical and experiential knowledge that each one has and is applied in a virtual environment. The main objective of the study is "to implement a model for the co-creation and production of open educational contents through the usage of a virtual platform", which is circumscribed in the qualitative perspective, from the hermeneutical methodological approach. As results and conclusions, it is stated that the concept of co-creation opens up multiple possibilities to create enriched processes, led and generated by both the teacher and the students. It is a two-way action where both profiles propose, produce, and distribute in order to generate educational resources and share interest and common knowledg