Author supplied from the article: Abstract A temperature compensated hydrogen sensor was designed and made capable of detecting H2 within a broad range of 100–10.000 ppm while compensating instantaneously for large (±25 °C) temperature variations. Two related operational constraints have been simultaneously addressed: (1) Selective, and sensitive detection under large temperature changes, (2) Fast warning at low and increasing H2 levels. Accurate measurements of hydrogen concentrations were enabled by matching relevant time-constants. This was achieved with a microchip having two temperature coupled palladium nanowires. One of the H2 sensitive Pd nanowires was directly exposed to hydrogen, whilst the other nanowire was used as a temperature sensor and as a reference. A drop forging technique was used to passivate the second Pd wire against H2 sensing. Temperature effects could be substantially reduced with a digital signal processing algorithm. Measurements were done in a test chamber, enabling the hydrogen concentration to be controlled over short and long periods. An early response for H2 sensing is attainable in the order of 600 milliseconds and an accurate value for the absolute hydrogen concentration can be obtained within 15 s.
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From Science direct: One of the nanowires was covered with a 2-Hydroxyethyl methacrylate based compound to prevent hydrogen from reaching the wire. The compound was dried by a UV source and tested in chamber for comparison with previous measurements. The results shows that temperature effects can be reduced by a digital signal processing algorithm without measuring temperature near or at the substrate. With this method no additional temperature probes are necessary making this solution a candidate for ultra low power wireless applications.
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From Springer description: "We present the design considerations of an autonomous wireless sensor and discuss the fabrication and testing of the various components including the energy harvester, the active sensing devices and the power management and sensor interface circuits. A common materials platform, namely, nanowires, enables us to fabricate state-of-the-art components at reduced volume and show chemical sensing within the available energy budget. We demonstrate a photovoltaic mini-module made of silicon nanowire solar cells, each of 0.5 mm2 area, which delivers a power of 260 μW and an open circuit voltage of 2 V at one sun illumination. Using nanowire platforms two sensing applications are presented. Combining functionalised suspended Si nanowires with a novel microfluidic fluid delivery system, fully integrated microfluidic–sensor devices are examined as sensors for streptavidin and pH, whereas, using a microchip modified with Pd nanowires provides a power efficient and fast early hydrogen gas detection method. Finally, an ultra-low power, efficient solar energy harvesting and sensing microsystem augmented with a 6 mAh rechargeable battery allows for less than 20 μW power consumption and 425 h sensor operation even without energy harvesting."
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Deze praktijkaanbeveling is oorspronkelijk vervaardigd in het kader van het "Technologie Centrum voor Verbinden" van het NIL. Titaan is in vergelijking met staal en aluminium een duur metaal. Titaan wordt voornamelijk gebruikt in de procesindustrie (reactorvaten) vanwege zijn zeer goede corrosiewerende eigenschappen. Het materiaal is verder uitstekend geschikt voor medische toepassingen zoals pacemakers en prothesen. De hoge sterkte/gewichtsverhouding van titaanlegeringen maakt dit materiaal interessant voor toepassingen in de ruimtevaart en voor sportartikelen zoals fietsframes en tennisrackets. De toepassing als brilmontuur heeft dit materiaal te danken aan de combinatie van goede corrosiewerende eigenschappen, licht gewicht en hoge sterkte. Door de recentelijke daling van de titaanprijs worden titaanlegeringen ook toepast voor offshore constructies vanwege de combinatie van goede corrosiebestendigheid en hoge sterkte. Een geheel nieuwe toepassing is het gebruik van titaan in de architectuur. De decoratieve matgrijze kleur van het titaanoppervlak maakt dit materiaal interessant voor overkappingen van hallen, stationruimtes e.d.
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This whitepaper explores what the impact is of the operating system (OS) of a smartphone on its lifespan, costs and environmental impact.
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Author supplied: Abstract—The growing importance and impact of new technologies are changing many industries. This effect is especially noticeable in the manufacturing industry. This paper explores a practical implementation of a hybrid architecture for the newest generation of manufacturing systems. The papers starts with a proposition that envisions reconfigurable systems that work together autonomously to create Manufacturing as a Service (MaaS). It introduces a number of problems in this area and shows the requirements for an architecture that can be the main research platform to solve a number of these problems, including the need for safe and flexible system behaviour and the ability to reconfigure with limited interference to other systems within the manufacturing environment. The paper highlights the infrastructure and architecture itself that can support the requirements to solve the mentioned problems in the future. A concept system named Grid Manufacturing is then introduced that shows both the hardware and software systems to handle the challenges. The paper then moves towards the design of the architecture and introduces all systems involved, including the specific hardware platforms that will be controlled by the software platform called REXOS (Reconfigurable EQuipletS Operating System). The design choices are provided that show why it has become a hybrid platform that uses Java Agent Development Framework (JADE) and Robot Operating System (ROS). Finally, to validate REXOS, the performance is measured and discussed, which shows that REXOS can be used as a practical basis for more specific research for robust autonomous reconfigurable systems and application in industry 4.0. This paper shows practical examples of how to successfully combine several technologies that are meant to lead to a faster adoption and a better business case for autonomous and reconfigurable systems in industry.
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From the article: "A facile approach for the fabrication of large-scale interdigitated nanogap electrodes (nanogap IDEs) with a controllable gap was demonstrated with conventional micro-fabrication technology to develop chemocapacitors for gas sensing applications. In this work, interdigitated nanogap electrodes (nanogap IDEs) with gaps from 50–250 nm have been designed and processed at full wafer-scale. These nanogap IDEs were then coated with poly(4-vinyl phenol) as a sensitive layer to form gas sensors for acetone detection at low concentrations. These acetone sensors showed excellent sensing performance with a dynamic range from 1000 ppm to 10 ppm of acetone at room temperature and the observed results are compared with conventional interdigitated microelectrodes according to our previous work. Sensitivity and reproducibility of devices are discussed in detail. Our approach of fabrication of nanogap IDEs together with a simple coating method to apply the sensing layer opens up possibilities to create various nanogap devices in a cost-effective manner for gas sensing applications"
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In deze publicatie wordt ingegaan op het verbinden van dunne plaat en buis met behulp van de diverse soldeerprocessen. Deze publicatie is er een uit een serie van vijf die naast de algemene publicatie (TI.03.13) tevens drie andere verbindingstechnieken behandelen, zoals lassen (TI.03.14), lijmen (TI.03.15) en mechanisch verbinden (TI.03.16).
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Deze publicatie is binnen het project 'nieuwe materialen' ontwikkeld en geeft informatie over nieuwe(re) roestvaste staalkwaliteiten, en is gericht op de verwerkers van dunne plaatmaterialen met dikten van 0,3 t/m ca. 3 mm. Een deel van de informatie is evenwel ook van toepassing voor andere plaatdikten en andere producten uit roestvast staal. In het kader van dit project zijn tevens uitgegeven: TI.04.18 'Hoge Sterkte Staal in dunne plaat en buis', TI.04.20 'Scheidingstechnieken voor dunne plaat en buis', TI.04.21 'Aluminium in dunne plaat en buis' en TI.04.22 'Ontwerpen van dunne plaat producten en de Eindige Elementen Methode.
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Voor u ligt de voorlichtingspublicatie "Hoogtemperatuursolderen". Deze publicatie is bedoeld voor allen die te maken hebben of te maken krijgen met de techniek van het hoogtemperatuursolderen. Daarbij moet worden gedacht aan bijvoorbeeld constructeurs, ontwerpers, lastechnici, werkvoorbereiders, enzovoorts. Deze voorlichtingspublicatie is een update van de in 1992 verschenen eerste druk die indertijd onder auspiciën van de NIL-werkgroep van de Technische Commissie I-A Subcie Hoogtemperatuursolderen is opgesteld. De updating was noodzakelijk, daar zich in de afgelopen jaren een groot aantal ontwikkelingen heeft voorgedaan op het gebied van soldeertechnieken.
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