36 research outputs found
Amsterdam as a Sustainable European Metropolis: Integration of Water, Energy and Material Flows
No full textAmsterdam has the ambition to develop as a competitive and sustainable European metropolis. The flows of energy, water and resources within the urban environment have a large potential to contribute to this ambition. The overall mass balances of phosphate, food, water, energy and material imports in the Amsterdam region have already been mapped. Through a transition from a linear usage of resources and waste production without feedbacks of resources, towards a sustainable management of urban resources with circular flows of resources, the sustainability of cities can be increased. This Urban Harvesting Concept can be applied in Amsterdam. The challenge is to operationalize this concept in practice. Two municipal companies in Amsterdam, Waternet and AEB, take initiatives to create closed cycles within their working areas. Waternet is the water company of Amsterdam and surroundings responsible for all water activities. AEB is the company which operates two waste-to-energy plants in Amsterdam. The focus is on water, energy, waste and material flows. Integration of these cycles is also part of the initiatives. These circular flows result in economic benefits and sustainability benefits, either expressed as Ecopoints or CO2-emissions.Water ManagementCivil Engineering and Geoscience
The Failure Probability of a Slope
No full textThere is about 18000 km of dikes in The Netherlands. Their use is to prevent the lowlands, where the inhabitants live, from flooding. Flooding is a typical high-consequence low-probability event. To study the failure probability of a dike, one of the numerical methods available, derived from the Level III probabilistic methods, is the so-called Monte Carlo simulation (MCs). The Finite Element Method (FEM) program PLAXIS is widely used to study dike stability. This dike stability can be quantified by means of the Safety Factor (SF). However, estimating the failure probability of a dike with PLAXIS is at present not possible and even if the MCs will be installed, the calculation will be time consuming. In order to overcome this problem, an easy and quick method is needed to estimate the failure probability of a dike. This project uses a study case described by a circular slip failure surface of a dike with three independent layers. Each layer is defined by its undrained shear strength with a normal distribution function. Besides MCs, an analytical solution for the SF of a slope, which is a linear combination of the soil strength for a fixed slip circle, was developed. The project compares the failure probability value obtained by both the MCs and the analytical solution. Finally, using the analytical solution, the failure probability estimation of a slope is presented by a quick and easy procedure to use with FEM.Civil Engineering and Geoscience
Online Anticipatory Network Management: The dynamic steering of route choice behaviour with traffic control and traffic information
No full textIn order to improve the usage efficiency of the road network, this research investigates and proposes an approach for a traffic management solution called Online Anticipatory Network Management. The proposed traffic management solution aims to redistribute traffic flows and to increase network performance by determining and applying traffic control settings that optimally affect travel times, route choices and thus network distribution, while informing drivers about the modified travel times and anticipating their reaction. This research investigate the concept of this approach and its feasibility, by analysing the environment and its components and methodology. Hereafter the framework matching the approach is applied on theoretical networks to validate and improve it. Finally, points of further research are discussed and a structure for a possible implementation is envisioned.Civil Engineering and GeosciencesTransport & Plannin
Bereikbaarheidsanalyse Rotterdamse haven
No full textDit rapport bekijkt de bereikbaarheid van de Rotterdamse haven in het jaar 2030 om een beeld te geven van de gesteldheid van de verschillende modaliteiten. Hierbij worden er drie modaliteiten bekeken namelijk de weg, het spoor en de binnenvaart. De algemene methode hierbij is om de knelpunten in het netwerk te vinden en een advies te geven hoe ze mogelijkerwijs opgelost kunnen worden.Transport & PlanningCivil Engineering and Geoscience
A strategy towards Integrated Road Network Traffic Management: Facilitating the realisation of Online Anticipatory Network Management
No full textCivil Engineering and GeosciencesStructural EngineeringConstruction Management and Engineerin
Less attractive or intelligent? The effect of L2 English language errors and knowledge about nativeness in dating profile texts.
No full textThere has been minimal research into language errors in online dating profile texts in combination with knowledge about nativeness of the author. Therefore, this study investigated whether language errors and knowledge about non-nativeness in English has an effect on the perceived attractiveness and intelligence of the author. Each variable had two levels, language errors or no language errors and knowledge about nativeness or no knowledge about nativeness. The aim of the study was to get more insight into what matters for people when they are looking for a partner on an online dating site and if language errors have a negative influence on how the author is perceived so that people can take this into account when setting up their respective dating profiles. To answer the research question, an experiment was conducted with three dating profile texts retrieved from OKcupid that contained naturally occurring language errors
Sharing tacit knowledge to understand reality
No full textThe author gives her answer to the question of knowledge production in science and society, according to a theoretical framework (The social construction of reality: a treatise in the sociology of knowledge; Berger, Luckmann, 1966
Analysis of a scheme which preserves the dissipation and positivity of Gibbs' energy for a nonlinear parabolic equation with variable diffusion
No full textIn this work, we design and analyze a discrete model to approximate the solutions of a parabolic partial differential equation in multiple dimensions. The mathematical model considers a nonlinear reaction term and a space-dependent diffusion coefficient. The system has a Gibbs' free energy, we establish rigorously that it is non-negative under suitable conditions, and that it is dissipated with respect to time. The discrete model proposed in this work has also a discrete form of the Gibbs' free energy. Using a fixed-point theorem, we prove the existence of solutions for the numerical model under suitable assumptions on the regularity of the component functions. We prove that the scheme preserves the positivity and the dissipation of the discrete Gibbs' free energy. We establish theoretically that the discrete model is a second-order consistent scheme. We prove the stability of the method along with its quadratic convergence. Some simulations illustrating the capability of the scheme to preserve the dissipation of Gibb's energy are presented.The corresponding author (J.E.M.-D.) wishes to acknowledge the financial support from the National Council for Science and Technology of Mexico (CONACYT) through grant A1-S-45928
Optical properties of strained wurtzite gallium phosphide nanowires
No full textWurtzite gallium phosphide (WZ GaP) has been predicted to exhibit a direct bandgap in the green spectral range. Optical transitions, however, are only weakly allowed by the symmetry of the bands. While efficient luminescence has been experimentally shown, the nature of the transitions is not yet clear. Here we apply tensile strain up to 6% and investigate the evolution of the photoluminescence (PL) spectrum of WZ GaP nanowires (NWs). The pressure and polarization dependence of the emission together with a theoretical analysis of strain effects is employed to establish the nature and symmetry of the transitions. We identify the emission lines to be related to localized states with significant admixture of Δ7c symmetry and not exclusively related to the Δ8c conduction band minimum (CBM). The results emphasize the importance of strongly bound state-related emission in the pseudodirect semiconductor WZ GaP and contribute significantly to the understanding of the optoelectronic properties of this novel material. Funding Details: J3540-N30, FWF, Austrian Science Fund
Evolução Do Dano Num Quebra-Mar De Taludes Em Cenários De Alterações Climáticas
No full textNo âmbito do projeto HYDRALAB+ (H2020-INFRAIA-2014-2015), foi realizado no LNEC um conjunto de ensaios em modelo físico bidimensional (2D) de um perfil de um quebra-mar de talude em enrocamento, construído à escala geométrica 1:30, para diferentes condições de agitação marítima e níveis de maré correspondentes a cenários de alterações climáticas. Estas experiências tinham como objetivo analisar o dano, o espraiamento e o galgamento, nesses cenários.Em paralelo, na FEUP, e em colaboração com Deltares, foram realizados testes com a mesma configuração de quebra-mar, mas utilizando um modelo físico tridimensional (3D), construído à escala geométrica 1:35. Os resultados obtidos permitiram analisar a evolução do dano no manto resistente do quebra-mar (talude de barlamar, talude de sotamar e cabeça), assim como o galgamento, para condições com e sem sobrelevação do nível médio do mar, considerando ou não a reconstrução do talude do quebra-mar entre testes consecutivos da mesma série de testes. Foram também realizados testes com ondas multidirecionais.O presente trabalho incide sobre a análise da evolução do dano para as diferentes sequências de tempestade em cenários de alterações climáticas. O dano é avaliado com base no tradicional método de contagem de blocos removidos e ainda com base no parâmetro adimensional do dano, S recorrendo a técnicas estereofotogramétricas. É também feita uma avaliação do parâmetro E2D.Em termos gerais, concluiu-se que não havia diferenças significativas entre os testes com danos cumulativos e com a reconstrução do quebra-mar após cada teste. Observou-se, também, que o dano era mais elevado na proximidade da superfície livre e que aumentava com a altura de onda significativa. Os danos foram, em geral, menores nos testes com ondas multidirecionais.Hydraulic Structures and Flood Ris
