165 research outputs found
The fine-grained metaphysics of artifactual and biological functional kinds
No full textIn this paper we consider the emerging position in metaphysics that artifact functions characterize real kinds of artifacts. We analyze how it can circumvent an objection by David Wiggins (Sameness and substance renewed, 2001, 87) and then argue that this position, in comparison to expert judgments, amounts to an interesting fine-grained metaphysics: taking artifact functions as (part of the) essences of artifacts leads to distinctions between principles of activity of artifacts that experts in technology have not yet made. We show, moreover, that our argument holds not only in the artifactual realm but also in biology: taking biological functions as (part of the) essences of organs leads to distinctions between principles of activity of organs that biological experts have not yet made. We run our argument on the basis of analyses of artifact and biological functions as developed in philosophy of technology and of biology, thus importing results obtained outside of metaphysics into the debate on ontological realism. In return, our argument shows that a position in metaphysics provides experts reason for trying to detect differences between principles of activities of artifacts and organs that have not been detected so far.Engineering and reflectionTechnology, Policy and Managemen
Integrated Language Definition Testing: Enabling Test-Driven Language Development
No full textThe reliability of compilers, interpreters, and development environments for programming languages is essential for effective software development and maintenance. They are often tested only as an afterthought. Languages with a smaller scope, such as domain-specific languages, often remain untested. General-purpose testing techniques and test case generation methods fall short in providing a low-threshold solution for test-driven language development. In this paper we introduce the notion of a language-parametric testing language (LPTL) that provides a reusable, generic basis for declaratively specifying language definition tests. We integrate the syntax, semantics, and editor services of a language under test into the LPTL for writing test inputs. This paper describes the design of an LPTL and the tool support provided for it, shows use cases using examples, and describes our implementation in the form of the Spoofax testing language. This paper is a pre-print of: Lennart C. L. Kats, Rob Vermaas, Eelco Visser. Integrated Language Definition Testing. Enabling Test-Driven Language Development. In Kathleen Fisher, editor, Proceedings of the 26th Annual ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications (OOPSLA 2011), ACM, 2010.Software TechnologyElectrical Engineering, Mathematics and Computer Scienc
Engineering Systems Design: A Look to the Future
No full textEngineering Systems Design is an emerging perspective with a growing community. The preceding chapters in the Handbook of Engineering Systems Design presented the engineering systems perspective, models for describing and methods for designing interventions in engineering systems, as well as reflections on the use of those methods and upcoming practice, educational and policy challenges. In this chapter, we are taking a look at the future of Engineering Systems Design. We start by highlighting productivity, sustainability and resilience as three societal objectives, and proceed to discuss critical paradoxes we must address through engineering systems interventions: providing a high standard of living for everyone, without paying the environmental price; a fast minimisation and mitigation of climate change without taking risks; and the challenge of global transformations respecting local needs. We continue to discuss what we consider three critical engineering systems design capabilities we must develop to resolve these paradoxes: the ability to manage systems requirements at societal scale; the development of scale-covariant engineering systems; and mastering connectability. We conclude the chapter with a call to action for researchers, practitioners and policy makers to advance theory, design methods and tools, and stakeholder outreach development to strengthen our engineering systems design capabilities
Towards Precedence that Justifies the Knowledge Claims of Design Methods
No full textThis paper analyses the relation between the precedence of a design method and the justification of the method. A design method is assumed to advance two knowledge claims concerning its domain of application: that it is an effective means for designing and that it is an efficient means for doing so. It is argued that precedence of a method can justify these knowledge claims under two conditions. The first is that precedence, in addition to descriptions of successful design projects realized with the method, also comprises: (1) negative precedence of unsuccessful design projects; and (2) comparative precedence of design projects carried out with other methods rival to the method concerned. The second condition is that the two knowledge claims of a method can be justified by precedence about only exemplar design tasks that represent the full application domain of the method.Accepted Author ManuscriptEthics & Philosophy of Technolog
Mixing layers in open channel flow with abrupt bed roughness changes
No full textHydraulic roughness is a key factor in modeling open channel flow. The frictional effects of roughness elements are generally parameterized by a roughness coefficient, representative for the roughness of a grid cell in a model. Bed roughness can be very heterogeneous in practical situations. Especially in floodplains, the roughness height can differ an order of magnitude over a small distance. This roughness heterogeneity impacts the shear stress distribution and the effective friction exerted on the flow. Previous research showed that the effective friction was 20% more than the theoretically weighted average value (Jarquín, 2007) in a flume with a parallel smooth-to-rough bed. Another calculation showed even 80% additional effective friction (Jarquín, 2007; Vermaas et al., 2007). New measurements and a detailed Large Eddy Simulation model described in this report were used to investigate the underlying mixing layer processes and the corresponding development length scales. This may provide the basis to parameterize roughness heterogeneity. Measurements in a developed flow over a parallel smooth-to-rough bottom show a secondary circulation in vertical planes across the flow. This circulation causes a transverse momentum transport from the smooth to the rough side. The momentum transport by this mechanism has nearly the same order of magnitude as the transverse momentum exchange by turbulent mixing. The transverse momentum exchange enhances the effective friction. An example with a 2D model shows that this can not explain the entire increase in effective friction; additional friction is probably also caused by extra turbulence production near the smooth-to-rough interface, and bed shear stress in the spanwise direction. In the transition from a uniform flow to a compound flow over parallel roughness lanes, transverse volume transport occurs mainly in the first 4 meter (twice the width of the flume), with a maximum velocity at the start of the parallel roughness section. The development length of the velocity profiles can be scaled to the depth of flow. The vertical profiles outside the mixing layer develop in about 25 times the water depth; the mixing layer at mid depth in about 50 water depths. The secondary circulation was estimated to be fully developed after 80 water depths, but has already a significant momentum transport at half of this distance. Furthermore, the depth averaged transverse mass transport causes a gradient in the advected longitudinal momentum and therefore the water level slope is even more increased above the start of a parallel rough bottom. As a typical example of repetitive changing roughness, the flow over a roughness pattern resembling an elongated checkerboard pattern was tested. The flow appeared to develop much slower in each section than over a single parallel (infinitely long) roughness. The maximum velocity remains close to the smooth-to-rough interface and no secondary flow is observed in this configuration. Turbulent mixing is neither very effective since the vortices are changing direction not before 1 meter after a roughness change. Nevertheless, the effective friction is seriously increased by this configuration; about 30% additional friction is observed in comparison with a developed parallel flow without transverse interaction. This can be explained by the large adaptation length of the flow relative to the size of the checkerboard fields. The flow velocity is relatively large over the rough fields, and slow over the smooth fields, causing the additional drag.Hydrology and Quantitative Water ManagementWater ManagementCivil Engineering and Geoscience
Electrochemical CO<sub>2</sub> capture can finally compete with amine-based capture
No full textElectrochemical CO2 capture is promising for closing the carbon cycle but needs technological advances. In a recent issue of Nature Energy, a novel chemistry for electrochemical CO2 capture is presented, demonstrating low energy consumption and high purity with virtually no degradation. This finally allows competition with amine-based capture technology.reen 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.ChemE/Transport PhenomenaLarge Scale Energy Storag
Gas bubble removal from a zero-gap alkaline electrolyser with a pressure swing and why foam electrodes might not be suitable at high current densities
No full text<div>This is a short instruction file for the datasets that were used for the paper:</div>
<div>"Gas bubble removal from a zero-gap alkaline electrolyser with a pressure swing and why foam electrodes might not be suitable at high current densities"</div>
<div>by Jorrit Bleeker, Celine van Kasteren, J. Ruud van Ommen, David A. Vermaas*</div>
<div>*Corresponding Author</div>
<div> </div>
<div>1. The data for all figures are included in excel files here.</div>
<div> </div>
<div>2. For Figure 7 python scripts are included of the pressure swing model</div>
<div>We recommend running these in Spyder 4.2.5. (Python 3.8)</div>
A logical critique of the expert position in design research: beyond expert justification of design methods and towards empirical validation
No full textThis paper gives a general and logical analysis of the expert position in design research bywhich methods for innovative design can be derived from expert design practices. It firstgives a framework for characterising accounts of design by the way in which they defineand relate general, descriptive and prescribed types of design practices. Second, it analyseswith this framework the expert position's conservatism of prescribing existing expert designpractices to non-expert designers. Third, it argues that the expert status of expert designersdoes not provide suficient justification for prescribing expert design practices to non-expert designers; it is shown that this justification needs support by empirical testing.Fourth, it discusses validation of designmethods for presenting an approach to this testing.One consequence of the need to empirically test the expert position is that its prescriptionhas to be formulated in more detail. Another consequence is that it undermines the expertposition since expert design practices are not anymore certain sources for deriving designmethods with. Yet it also opens the expert position to other sources for developing designmethods for innovation, such as the practices of contemporary designers and the insightsof design researchers
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