1,720,952 research outputs found
From Degradation to Regeneration: Revitalizing the socio-ecological agricultural landscapes of North-West European Lowlands
No full textThe current food production and distribution system has led to extensive degradation on both the global and local scale, requiring a transformation of the vast, urbanized rural - beyond just climate-change mitigation but radical regeneration. The ongoing intensive agricultural practices have contaminated air, soil, and water, while their market- driven character disallows the emergence of locality and circularity, exploiting workers and small-scale farmers, and disrupting the social welfare of the countryside. This system is analysed through the lenses of ecology, economy, and society, highlighting the problematic character of the Lowlands of North-West Europe, due to the immense sprawl of degenerative agriculture practices, as well as the small and fragmented network of ecosystem-valuable spaces. Following the most urgent climate-change scenario from the IPCC report, we will attempt the transition from a degenerative system towards a regenerative one, based on the pillars of ecosystem restoration, ensuring food security through sustainable means, and the shift towards regenerative agriculture practices. Concerns about spatial justice permeate all pillars horizontally, to ensure the socio- spatial regeneration of the countryside. To transition towards our vision, the strategy is approached through a series of interconnected key projects. The formation of a pan-European network of tree nurseries ensures the necessary capital of seedlings for reforestation and agroforestry practices, while a trans-border policy zone can integrate conservation and agriculture, enhancing the connectivity between ecosystems. The greenhouse zone of Westland is experimented upon, aiming towards the development of a replicable model of sustainably intensive food production model. These strategic interventions are underlined by a policy framework, stressing the liveability of the Lowlands for all rural dwellers, farmers, and workers, through access to services, education, and housing. Through this experimentation we hope to have highlighted that the examination of the countryside needs to be intrinsically tied to any effort of envisioning a future of climate- change mitigation and socio-ecological regeneration. AR2U086 R&D Studio – Spatial Strategies for the Global MetropolisArchitecture, Urbanism and Building Sciences | Urbanis
Removal of organic micropollutants in a drinking water treatment plant by powdered activated carbon followed by rapid sand filtration
No full textPowdered activated carbon (PAC) is a promising technology to reduce organic micropollutants (OMPs) in drinking water treatment plants and combined with biological treatment processes such as rapid sand filters (RSFs), has the potential to remove a broad range of OMPs during water treatment. However, the removal of OMPs by a combination of two treatments (PAC-RSF) is not fully understood. 49 OMPs were spiked in PAC followed by RSF pilot plant treatment and the effluent was measured after 1, 4 and 7 day(s). Also, in a separate experiment 29 OMPs (out of 49) were dosed into the RSF column to assess the removal of OMPs by just RSF. Statistical analyses were performed and the OMPs were classified according to their charge and hydrophobicity. The results showed that OMPs were removed at the highest percentage after the first 24 h of dosing. The highest removal was observed for the neutral and hydrophobic compounds (80.0%–99.5%). The removal of neutral and hydrophilic compounds varied (0.14%–98.5%) depending on the possibility of forming π-π interactions and hydrogen bonds. Electrostatic repulsion between anionic OMPs and negatively charged PAC led to a decrease in the removal of anionic compounds. In contrast, electrostatic attraction led to an increase in the removal of cationic OMPs. Regarding OMPs removal by RSF, some compounds were removed by the sand filter depending partly on their physical-chemical properties and more dominantly on their functional groups. By comparing the OMPs removal by PAC-RSF with RSF, it was possible to determine the contribution of biological processes in the sand filter in the removal of some OMPs.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Sanitary Engineerin
Stability of stones on mild slopes
No full textThe static stability of stones on mild slopes under wave attack is investigated in this research. The first part of the research is focused on reproducing the physical scale model tests regarding profile change of Kramer (2016) numerically with the model XBeach-G. The erosion profiles modelled with the bed-load transport formulas of Nielsen (2006) and Van Rijn (2007) in XBeach-G do not match the erosion profiles of the profile change experiments of Kramer (2016). The bed-load transport formulas of Nielsen (2006) and Van Rijn (2007) are not able to model the sediment transport in XBeach-G accurately. Furthermore, XBeach-G cannot determine the velocity and acceleration near the bed, because the model solves the flow due to currents and waves for a single layer. Therefore, it can be concluded that XBeach-G should not be used to describe static stability of stones on mild slopes under wave attack. For the application of dynamically stable structures (which is not investigated in this research), XBeach-G functions satisfactorily (Postma, 2016). For further research, a model that solves the hydrodynamics for multiple layers should be applied. In this way, the hydrodynamics near the bed can be used to describe the static stability of stones. The aim of the second part of the research is to develop a design method that describes the static stability of stones on mild slopes under wave attack. The basis of this design method is the initiation of motion of a stone and the hydrodynamic forces that initiate this movement. The hydrodynamic forces and corresponding mobility parameters are determined with the velocity and the acceleration near the bottom. Using Bubble Image Velocimetry (BIV), the velocity and the acceleration are derived from the videos of the BIV experiments of Kramer (2016) with regular waves breaking on a slope. It is found from the results of the BIV analysis that the effective, adapted Shields parameter θ’McCall can be used to describe movements of stones on mild slopes under wave attack. This mobility parameter has been determined with the bed shear stress of McCall (2015), which added an inertia term to include the influence of accelerations. For initiation of motion of stones, it appears that the stability parameter θcr could be a value of 0.024 (in case no slope correction factor has been applied). To substantiate a design method that describes the static stability of stones on mild slopes under wave attack, the value of 0.024 could be used to define a threshold for initiation of motion of stones. More experiments need to be executed to optimize this value of the stability parameter. Moreover, a statistical value for the stability parameter could be used (like θcr,1%) to describe the static stability of stones by means of a certain number of stones that are allowed to move for a certain number of waves
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
CHANGE ANALYSIS OF LASER SCANS OF LABORATORY ROCK SLOPES SUBJECT TO WAVE ATTACK TESTING
No full textFor better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave attack, a terrestrial laser scanner was used to obtain 3D coordinates of the rock surface before and after each experiment. Next, through a series of processing steps, the point clouds were converted to a suitable 2D raster for change analysis. This allowed to estimate detailed and quantitative change information. The results indicate that the area around the artificial coast line, defined as the intersection between sloped surface and wave surface, is most strongly affected by wave attacks. As the distances from the sloped surface to the waves are shorter, changes for the mildly sloped surface, slope 1 (1 : 10), are distributed over a larger area compared to the changes for the more steeply sloped surface, slope 2 (1 : 5). The results of this experiment show that terrestrial laser scanning is an effective and feasible method for change analysis of rock slopes in a laboratory setting. Most striking results from a process point of view is that the transport direction of the rocks change between the two different slopes: from seaward transport for the steeper slope to landward transport for the milder slope
- …
