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Martin Ouwerkerk

Bio: Martin Ouwerkerk is an academic researcher from Philips. The author has contributed to research in topics: Electrode & Hydride. The author has an hindex of 20, co-authored 75 publications receiving 1351 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, it was shown that thin layers of palladium coated magnesium lanthanide alloys reversibly go through an optical transition by variation of the hydrogen concentration, just as has recently been shown for pure lanthanides.
Abstract: It is shown that thin layers of palladium coated magnesium lanthanide alloys reversibly go through an optical transition by variation of the hydrogen concentration, just as has recently been shown for pure lanthanides. With these layers optical switches can be constructed that exhibit three different optical states: a color-neutral transparent state at high hydrogen concentration, a nontransparent dark absorbing state at intermediate hydrogen pressures, and a highly reflective metallic state at low hydrogen pressures. The ratio in transmission between the transparent state and the reflecting state is more than 1000.

196 citations

Proceedings ArticleDOI
20 Jun 2013
TL;DR: The main results of the evaluation are that the results of long-term measurements of stress reveal people information about their behavioral patterns that they perceive as meaningful and useful, and trigger their ideas about behavioral changes necessary to achieve a better stress balance.
Abstract: Due to the growing pace of life, stress became one of the major factors causing health problems. We have developed a framework for measuring stress in real-life conditions continuously and unobtrusively. In order to provide meaningful, useful and actionable information, we present stress information, derived from sensor measurements, in the context of person's activities. In this paper, we describe our framework, discuss how we address arising challenges and evaluate our approach on basis of the field studies we have conducted. The main results of the evaluation are that the results of long-term measurements of stress reveal people information about their behavioral patterns that they perceive as meaningful and useful, and trigger their ideas about behavioral changes necessary to achieve a better stress balance.

120 citations

Patent
16 Jan 2006
TL;DR: A treatment system for traversing the alimentary tract is described in this article, which includes an ingestible capsule, which includes a gas pressurizing module providing a gas and at least one balloon in fluid communication with the gas.
Abstract: A treatment system ( 1600, 1900 ) is provided for traversing the alimentary tract. The system ( 1600, 1900 ) includes an ingestible capsule, which includes a gas pressurizing module ( 1602 )) providing a gas and at least one balloon ( 1604, 1901 ) in fluid communication with the gas pressurization module ( 1602 ). The capsule further includes an exhaust channel ( 1610 ) in fluid communication with a respective balloon of the at least one balloon ( 1604, 1901 ), and a depressurizing closure member ( 1608 ) for selectively controlling flow of gas between the balloon ( 1604, 1901 ) and the ambient surroundings of the capsule. The system further includes control circuitry ( 906 ) for controlling the depressurizing closure member ( 1608 ).

89 citations

Journal ArticleDOI
TL;DR: In this article, two different strategies are outlined to develop both high energy density and space-efficient batteries, including the most widely applied rechargeable nickel-metal hydride (NiMH) and Li-ion batteries.

79 citations

Patent
Martin Ouwerkerk1, Martijn Krans1
03 Feb 2006
TL;DR: In this paper, a device for determining a stress related condition of a person and providing feedback about this condition consisting of body sensors (20) for detecting stress related body parameters, a stress assessing element (40), and a feedback device, wherein the stress assessment element is designed for processing input provided by the body sensors and for determining control parameters for controlling the feedback device.
Abstract: A device (1) for determining a stress related condition of a person and providing feedback about this condition comprises body sensors (20) for detecting stress related body parameters, a stress assessing element (40), and a feedback device, wherein the stress assessing element (40) is designed for processing input provided by the body sensors (20) and for determining control parameters for controlling the feedback device, on the basis of the input provided by the body sensors (20). The body sensors (20) are integrated in a textile structure, so that the tested person does not sense the sensors (20), as a result of which there is no chance that the test results get influenced by an interaction between the device (1) and the person.

64 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the hydrogen storage in metal hydrides with particular interest in Mg as it has potential to become one of the most promising storage materials, and the possibility of commercialization of Mg based alloys has been discussed.

922 citations

Journal ArticleDOI
12 Jan 2017-Sensors
TL;DR: This paper has presented and compared several low-cost and non-invasive health and activity monitoring systems that were reported in recent years and compatibility of several communication technologies as well as future perspectives and research challenges in remote monitoring systems will be discussed.
Abstract: Life expectancy in most countries has been increasing continually over the several few decades thanks to significant improvements in medicine, public health, as well as personal and environmental hygiene. However, increased life expectancy combined with falling birth rates are expected to engender a large aging demographic in the near future that would impose significant burdens on the socio-economic structure of these countries. Therefore, it is essential to develop cost-effective, easy-to-use systems for the sake of elderly healthcare and well-being. Remote health monitoring, based on non-invasive and wearable sensors, actuators and modern communication and information technologies offers an efficient and cost-effective solution that allows the elderly to continue to live in their comfortable home environment instead of expensive healthcare facilities. These systems will also allow healthcare personnel to monitor important physiological signs of their patients in real time, assess health conditions and provide feedback from distant facilities. In this paper, we have presented and compared several low-cost and non-invasive health and activity monitoring systems that were reported in recent years. A survey on textile-based sensors that can potentially be used in wearable systems is also presented. Finally, compatibility of several communication technologies as well as future perspectives and research challenges in remote monitoring systems will be discussed.

795 citations

Journal ArticleDOI
TL;DR: In this paper, a review of low-dimensional coordination polymers with one-dimensional polymeric structures is presented, focusing on the correlation between the molecular structure and the bulk properties of the materials.

503 citations

Journal ArticleDOI
TL;DR: In this article, the authors show that the hydrogen solubility of metal-hydrogen (M-H) systems is strongly affected by the morphology and microstructure of and the stress between regions of different hydrogen concentration.
Abstract: ▪ Abstract Metal-hydrogen (M-H) systems are interesting from both a theoretical and a practical point of view. M-H systems are utilized for energy-storage systems, in sensor applications, and in catalysis. These systems are often exploited as models for studying basic material properties, especially when the size of these systems is small and nonbulk-like contributions become dominant. Surfaces, nanocrystals, vacancy- and dislocation-rich materials, thin films, multilayers, and clusters as systems of major interest are addressed in this review. We show that the hydrogen solubility of M-H systems is strongly affected by the morphology and microstructure of and the stress between regions of different hydrogen concentration. For small-sized systems, surface- or interface-related sites become important and change the overall solubility as well as the phase boundaries of M-H systems. In thin films deposited on stiff substrates, compressive stresses evolve during hydrogen loading because the films are effective...

464 citations

Journal ArticleDOI
TL;DR: In this paper, a review of the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications, is presented.
Abstract: Hydrogen storage alloys are of particular interest as a novel group in functional materials owing to their potential and practical applications in Ni/MH rechargeable batteries. This review is devoted to the specific alloy families developed for high-energy and high-power Ni/MH batteries in the last decades, especially for EV, HEV and PHEV applications. The scope of the work encompasses principles of Ni/MH batteries, electrochemical hydrogen storage thermodynamics and kinetics, prerequisites for hydrogen storage electrode alloys and recent advances in hydrogen storage electrode alloys. Rare earth AB5-type alloys, Ti- and Zr-based AB2-type alloys, Mg-based amorphous/nanocrystalline alloys, rare earth-Mg–Ni-based alloys and Ti–V-based alloys are highlighted. Additionally, the challenges met in developing advanced hydrogen storage alloys for Ni/MH rechargeable batteries are pointed out and some research directions are suggested.

433 citations