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Design and modelling of a reversible shape memory alloy torsion hinge actuator

Liu, Q. (author), Ghodrat, S. (author), Jansen, K.M.B. (author)

Conventional hinge actuators often face limitations including excessive weight, large size and unpleasant noise. Shape memory alloys (SMAs) offer a solution to address these issues due to their favorable characteristics, such as lightweight, high actuation force and small form factor. However, most existing SMA-based hinge actuators rely on...

journal article 2024

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A proposal for the prediction of comfort and performance improvement through the use of cooling vests (for construction workers), under transient conditions

Roelofsen, C.P.G. (author), Jansen, K.M.B. (author)

In this study, using construction activities as an example, a proposal is made for the time-dependent prediction of the thermal sensation and the performance loss using a cooling vest, under transient conditions. The approach presented here can, mutatis mutandis, be used for any work activity and the use of a cooling vest, whether or not in a...

journal article 2022

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A larger statistical basis and a wider application area of a re-derived PPD equation in the (NEN-)EN-ISO 7730 model

Roelofsen, C.P.G. (author), Jansen, K.M.B. (author), Vink, P. (author)

This paper has the objective to initiate a discussion on potential improvements or extension of the validity of the original equation of the Predicted Percentage of Dissatisfied (PPD), according to (NEN-)EN-ISO 7730. This paper is to be regarded as a supplement to a paper on a re-derivation of the PMV equation in the Fanger model (Roelofsen,...

journal article 2022

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Comfort and performance improvement through the use of cooling vests for construction workers

Roelofsen, C.P.G. (author), Jansen, K.M.B. (author)

Purpose: The purpose of this study is to analyze the question “In what order of magnitude does the comfort and performance improvement lie with the use of a cooling vest for construction workers?”. Design/methodology/approach: The use of personal cooling systems, in the form of cooling vests, is not only intended to reduce the heat load, in...

journal article 2022

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Modelling and mechanical design of a flexible tube-guided SMA actuator

Liu, Q. (author), Ghodrat, S. (author), Jansen, K.M.B. (author)

Shape memory alloy (SMA) wires are excellent candidates for wearable actuators since they are thin, low weight and have a high actuation force. The main drawbacks are that the wire should be kept straight and needs to be relatively long to enable a large enough actuation stroke. Embedding the SMA wire in a flexible tube largely enhances its...

journal article 2022

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A new semi-orthotopic bone defect model for cell and biomaterial testing in regenerative medicine

Andrés Sastre, E. (author), Nossin, Y. (author), Jansen, I. (author), Kops, N. (author), Intini, C. (author), Witte-Bouma, J. (author), van Rietbergen, B. (author), Hofmann, S. (author), van Osch, G.J.V.M. (author)

In recent decades, an increasing number of tissue engineered bone grafts have been developed. However, expensive and laborious screenings in vivo are necessary to assess the safety and efficacy of their formulations. Rodents are the first choice for initial in vivo screens but their size limits the dimensions and number of the bone grafts...

journal article 2021

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A transient thermal sensation equation fit for the modified Stolwijk model

Roelofsen, C.P.G. (author), Jansen, K.M.B. (author), Vink, P. (author)

There are different thermal perception models linked to a mathematical thermophysiological human model, with which the thermal sensation under stationary and/or dynamic conditions can be evaluated. Each of these perception and thermophysiological models have their own field of application. Stolwijk developed a thermophysiological human model...

journal article 2021

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A larger statistical basis and a wider application area of the PMV equation in the Fanger model: Application area of the PMV equation

Roelofsen, C.P.G. (author), Jansen, K.M.B. (author), Vink, P. (author)

For sedentary activities, the PMV equation, derived by Fanger, is mainly based on the research of Nevins et al. (720 test subjects). Nevins' experiments were later on repeated by Fanger, but with 128 college-age Danish subjects and 128 elderly Danish subjects, instead of American subjects. Rohles did the research from Nevins et al. again, but...

journal article 2021

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Driver speed compliance following automatic incident detection: Insights from a naturalistic driving study

Varotto, Silvia F. (author), Jansen, Reinier (author), Bijleveld, Frits (author), van Nes, C.N. (author)

Automatic incident detection (AID) systems and variable speed limits (VSLs) can reduce crash probability and traffic congestion. Studies based on loop detector data have shown that AID systems decrease the variation in speeds between drivers. Despite the impact on driver behaviour characteristics, most mathematical models evaluating the...

journal article 2021

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Adaptations in driver deceleration behaviour with automatic incident detection: A naturalistic driving study

Varotto, Silvia F. (author), Jansen, Reinier (author), Bijleveld, Frits (author), van Nes, C.N. (author)

Traffic congestion and crash rates can be reduced by introducing variable speed limits (VSLs) and automatic incident detection (AID) systems. Previous findings based on loop detector measurements have revealed that drivers reduce their speeds while approaching traffic congestion when the AID system is active. Notwithstanding these behavioural...

journal article 2021

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Effect of temperature and humidity on moisture diffusion in an epoxy moulding compound material

Jansen, K.M.B. (author), Zhang, M. F. (author), Ernst, L. J. (author), Vu, D. K. (author), Weiss, L. (author)

In this paper we propose a new multistep characterisation method to be able to map out the dependency of moisture diffusion parameters of a polymeric material over a range of temperature and humidity conditions in a limited amount of time. We do that by (1) using a moisture sorption analyser which can continuously monitor weight changes with...

journal article 2020

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Effect of printing parameters on interlayer bond strength of 3D printed limestone-calcined clay-based cementitious materials: An experimental and numerical study

Chen, Y. (author), Jansen, K. (author), Zhang, H. (author), Romero Rodriguez, C. (author), Gan, Y. (author), Copuroglu, Oguzhan (author), Schlangen, E. (author)

For a single batch material, time intervals and nozzle standoff distances between two subsequent layers are two critical printing parameters that influence the mechanical performance of the printed concrete. This paper presents an experimental and numerical study to investigate the impacts of these printing parameters on the interlayer bond...

journal article 2020

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Understanding the effect of socio-economic characteristics and psychosocial factors on household water treatment practices in rural Nepal using Bayesian Belief Networks

Daniel, D. (author), Diener, Arnt (author), Pande, S. (author), Jansen, S.J.T. (author), Marks, Sara (author), Meierhofer, Regula (author), Bhatta, Madan (author), Rietveld, L.C. (author)

About 20 Million (73%) people in Nepal still do not have access to safely managed drinking water service and 22 million (79%)do not treat their drinking water before consumption. Few studies have addressed the combination of socio-economic characteristics and psychosocial factors that explain such behaviour in a probabilistic manner. In this...

journal article 2019

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Flow-based dissimilarity measures for reservoir models: a spatial-temporal tensor approach

Insuasty, Edwin (author), van den Hof, P.M.J. (author), Weiland, Siep (author), Jansen, J.D. (author)

In reservoir engineering, it is attractive to characterize the difference between reservoir models in metrics that relate to the economic performance of the reservoir as well as to the underlying geological structure. In this paper, we develop a dissimilarity measure that is based on reservoir flow patterns under a particular operational...

journal article 2017

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Use of reduced-order models in well control optimization

Jansen, J.D. (author), Durlofsky, L.J. (author)

Many aspects of reservoir management can be expected to benefit from the application of computational optimization procedures. The focus of this review paper is on well control optimization, which entails the determination of well settings, such as flow rates or bottom hole pressures, that maximize a particular objective function. As is the case...

journal article 2016

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Challenges in adjoint-based well location optimization when using well models

Ashoori, E. (author), Jansen, J.D. (author)

There is a general consensus that the most efficient method for large-scale well location optimization is gradient-based with gradients computed with an adjoint formulation. Handels et al. (2007) (later published in journal form as Zandvliet et al., 2008), were the first to use the adjoint method for well placement optimization for which they...

report 2015

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Value of information in closed-loop reservoir management

Barros, E.G.D. (author), Van den Hof, P.M.J. (author), Jansen, J.D. (author)

This paper proposes a new methodology to perform value of information (VOI) analysis within a closed-loop reservoir management (CLRM) framework. The workflow combines tools such as robust optimization and history matching in an environment of uncertainty characterization. The approach is illustrated with two simple examples: an analytical...

journal article 2015

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Hidden information in ill-posed inverse problems

Kahrobaei, S. (author), Mansoori, M. (author), Joosten, G.J.P. (author), Van den Hof, P.M.J. (author), Jansen, J.D. (author)

It is well known that parameter updating of large-scale numerical reservoir flow models (a.k.a. ‘computer assisted history matching’) is an ill-posed inverse problem. Typically the number of uncertain parameters in a reservoir flow model is very large whereas the available information for estimating these parameters is limited. The classic...

conference paper 2014

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Thermal simulation of a dinghy sailor

Joustra, J.J. (author), Jansen, A.J. (author)

This paper describes the development of a model to simulate a dinghy sailors’ body temperature during a sailing match. This simulation has been developed as part of the master thesis by the author: “Thermal optimization of competitive sailing gear”. A literature study is done to define the human body heat balance and thermal comfort. Next a...

journal article 2014

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Design and thermal testing of smart composite structure for architecture applications

Lelieveld, C. (author), Jansen, K.M.B. (author)

A composite structure consisting of a Shape Memory Polymer (SMP) matrix and three Shape Memory Alloy (SMA) strips was constructed. The SMA strips act as actuators which create forward and backward angle bends of 90 degrees of the composite structure. The function of the polymer matrix was to give the structure enough stiffness. During the...

conference paper 2013