Search

This paper, created by a group of aviation and energy experts from renowned universities and research centres in Europe, who oversee the fields of energy carriers, energy storage and conversion, propulsion, aerodynamics, flight mechanics, controls, structures, materials, multidisciplinary design, and life‐cycle engineering, aims to give an overview and assessment of promising future technologies. The paper therefore identifies the potential as well as research demands of these technologies on the path to a sustainable and more environmentally friendly aviation.

Introduction. To determine the effectiveness of fire-retardant coatings (FRC), a system of methods for fire and high-temperature testing of fire-retardant materials and structures made of themis being used. However, there are no methods and means that could provide current effectiveness of fire protection, and existing methods cannot be applied to determine fire resistance of building structures with fire protection, they set only a group of the effectiveness of the flame retardants. Therefore, to assess the quality and durability of the FRC, in case they provide the parameters of thermal stability of the protected materials, structures and elements of the engineering systems of the objects, it was necessary to develop a quickmethod and a portable diagnostic complex of fire-retardant coatings (PDC FRC). Methods, models and tools. Based on a system analysis of the existing fire protection technologies for building materials from wood, metals, rubber and polymers, a rapid analysis methodology and PDC or thermo-electro-acoustic (TEA) sensing of FRCs using thermo-acoustic methods have been developed. That made it possible to determine thermal conductivity, the ultrasound speed and its absorption coefficient in the FRC, as well as to conduct a comparative analysis of the «FRC image» obtained on a BETA-analyzer with measured characteristics, based on which to calculate the time of its operability. Results and discussion. The PDC of FRC consists of a case with a laptop, with the immitance meter and a two-channel oscillographic attachment connected to the laptop, to the inputs of which a TEA-zonding unit is pressed, pressed to the FRC of the tested object (structure, material, cable), by thermal, electrical and acoustic signals from which the laptop software identifies the properties and stages of operational stability of the FRC. The PDC of the FRC and the proposed approach allowed us to synthesize a model of the Internet system of TEA - diagnosis of FRC and of the monitoring of the operational stability of the protected materials. The novelty of the study is protected by patents of the Russian Federation

The use of glue-less assembly methods has permitted the construction of rigid structures for centuries. Japanese interlocking wood joints and stereotomic structures by repetitious stacking of unit blocks are classical examples. The implementation of interlocking structures occurs when materials such as mortar and nails are unavailable or undesired. There has been a recent revival of interest in these construction methods as modern manufacturing tools enable new form and function. As humanity continues to innovate, materials possessing mechanical properties such as heightened flexibility without compromising strength or increased resistance to fracture will be needed. As one such example, this work examines interlocking assemblies emerging from a rhombille tiling. Rhombille tilings are formed by using three rhombuses to create a regular hexagon, then tessellating those hexagons. The resulting assembly is one of disphenoids and has either triangular or hexagonal symmetry. The elements are arranged such that the assembly forms a hexagonal plate with two thirds the density of a solid plate of equal thickness. Rotation free and restricted states are realized. The mechanical properties of this interlocked assembly are examined in finite element analysis and experiments performed on physical models realized by 3D printing. Initial results suggest a chiral response to loading paths in the hexagonally symmetric arrangement. Triangularly symmetric arrangements suggest load paths based on concentric or patterned hexagons. These load patterns are distinctly different from those in comparable solid plates. All assemblies have shown fracture resistance where damage is localized to few elements, leaving the remainder of the plate intact.

Earth observation measurements at wavelengths below 320nm are challenging due to the steep decrease of the earth irradiance towards shorter wavelengths. Stray light and ghosting of longer wave light can easily overwhelm the signals at short wavelengths. In the UV channel (270-320nm) of the TROPOMI instrument this challenge has been addressed using a number of coatings. Three black UV mirror coatings absorb light with a wavelength above 370nm. Together, these achieve more than four orders suppression of long wave out-of-band light. A lowpass transmission filter with a position dependent cut-off wavelength is deposited on the last lens surface, directly in front of the detector. At the position where short wavelength light passes the filter, longer wavelength in-band stray light and ghosts are blocked. A simulation predicts that this graded filter reduces ghosting by a factor 20 and scatter related stray light by factor 30.

This report summarizes the work conducted within work package (WP) 5 "Verification of test matrix and protocol" of the Cyclist AEB testing system (CATS) project. It describes the verification process of the draft CATS test matrix resulting from WP1 and WP2, and the feasibility of meeting requirements set by CATS consortium based on requirements in Euro NCAP AEB protocols regarding accuracy, repeatability and reproducibility using the developed test hardware. For the cases where verification tests or additional information indicated that the protocol needed adaptation, proposed changes were discussed and upon agreement amongst the partners provided to the matrix including supporting argumentation. In WP1 the relevant accident scenarios have been determined, where in WP2 the most relevant accident parameters were extracted from accidentology and an additional observation study. Using these sources of information, a draft CATS test matrix has been developed. This draft CATS test matrix was used as a basis for the verification process. The process included workshops where all partners of the CATS consortium have been given the possibility to test the scenarios, a full spec test series was performed with a vehicle including a Cyclist-AEB system. Furthermore simulation studies were done and a robustness test series was performed to check the accuracies of the test protocol and the practical usability of the test equipment. Verification tests and simulations revealed that both the near-side CVNBU crossing scenario with 0% overlap and the far-side CVFB with 50% overlap crossing scenario were approximately equally difficult in terms of feasibility. It was therefore decided to change the collision point in the CVNBU test to 50% instead of 0% and the collision point in the CVFB scenario from 50% to 25%. Both changes still correspond to the parameters found in accidentology. This creates a two-step approach in terms of difficulty where the CVNBU is now less challenging and the CVFB more challenging. Furthermore it was found in the tests that the lateral accuracy of the target remains a challenge, especially for the longitudinal scenario with a long single belt. As a result, the collision point in the longitudinal scenario is changed from 20% to 25% since it is important that cyclist remains inside the width of the vehicle in terms of trigger an AEB activation. This still corresponds to the parameters found in accidentology.

This report summarizes the work conducted within work package (WP) 2 "Test scenario definition" of the CATS project. It describes relevant accident parameters for the 5 most dominant accidents scenarios defined in WP1. The objective of this WP2 is to construct car-to-cyclist accident test scenarios for the EU, based on the accident scenarios and accident parameters mainly obtained from France, Germany, Italy, the Netherlands, Sweden, as well as the United Kingdom. The focus is hereby set on accidents with killed and seriously injured casualties rather than on the overall accident population. The result from this study will be used as an input for the creation of an AEB car-to-cyclist test protocol. CATS will focus at the 3 dominant accident scenarios (C1: crossing bicycle from the near side, C2: crossing bicycle from the far-side and L: longitudinal scenario where car drives into the rear-side of a bicycle that rides in front of the vehicle in the same direction) only, for which at first DRAFT CATS scenarios are proposed. These accident scenarios together cover 63% and 78% of the seriously injured and fatal car-to-cyclist accidents for the investigated countries, respectively. Since the contribution to the coverage of On (Cyclist riding straight in the opposite (on-coming) direction) and T3 (Cyclist coming from the opposite direction, riding straight while car turning to far side) is relatively low and the On and T3 provide for essentially different scenarios, leading to additional test series, these accident scenarios are not taken into account at this moment in time.

To support and prepare the introduction of Cyclist-AEB systems and the appropriate consumer tests of such systems, TNO has taken the initiative to set-up a project with passenger car manufacturers and suppliers with the support of research and development partners (such as BASt and 4activeSystems) to develop a testing system and test protocol for Cyclist-AEB systems: CATS, Cyclist-AEB Testing System. This report describes the setup of the project and the approach that was followed from the start in June 2014 to the conclusion in June 2016. Moreover, the report summarises the most important results out of the project.

The number of fatalities in road traffic accidents in Europe is decreasing. Unfortunately, the number of fatalities among cyclists does not follow this trend with the same rate [1]. The au-tomotive industry is making a significant effort in the development and implementation of safety systems in cars to avoid or mitigate an imminent crash with vulnerable road users, in-cluding cyclists. The current state-of-the-art of active safety systems, Autonomous Emergency Braking (AEB), is being widely introduced. From 2018, AEB systems dedicated to avoid or miti-gate car-to-cyclist collisions will be considered in the safety assessment by Euro NCAP. To sup-port and prepare the introduction of Cyclist-AEB systems and the resulting consumer tests of such systems, an appropriate test protocol has been developed in the project CATS (Cyclist-AEB Testing System) with car manufacturers and automotive suppliers. In a previous paper [4], the most relevant accident scenarios for fatal and seriously injured car-to-cyclist collisions were identified, using an in-depth road accident study with data from Germany, the Nether-lands, Sweden, France, Italy, and the United Kingdom. In this paper a description is given how the distributions for the most relevant accident parameters in the identified accident scenarios have been determined. The CATS project resulted in a test protocol, including test parameters based on the distributions for the accident parameters, and a test setup. The results of the project have been shared with Euro NCAP.

This report summarizes the work conducted within work package (WP) 1 "accident analysis" of the CATS project. It describes the collection of data, the analyses as well as the final accident scenarios. The objective of this WP was to analyse car-to-cyclist accident scenarios in the EU, mainly obtained from data of France, Germany, Italy, the Netherlands, Sweden, as well as the United Kingdom. The focus is hereby set on accidents with killed and seriously injured casualties rather than on the overall accident population. The result from this study will be used as an input for the creation of an AEB car-to-cyclist a test protocol.

To support and prepare the introduction of Cyclist-AEB systems and the appropriate consumer tests of such systems, TNO has taken the initiative to set-up a project with passenger car manufacturers and suppliers and the support of Euro NCAP laboratories (such as BASt) to develop a testing system and test protocol for Cyclist-AEB systems: CATS, Cyclist-AEB Testing System. The objective of the second work package of the CATS project (WP2, "Test scenario definition") is to construct car-to-cyclist accident test scenarios for the EU, based on the accident scenarios and accident parameters mainly obtained from various EU countries. In [4], relevant accident parameters for the 5 most dominant accidents scenarios defined in WP1 are described. One of these parameters is a view-blocking obstruction in a near-side car-cyclist crossing scenario. Accident data, even not from the most detailed databases, usually does not describe behaviour of bicyclist (or cars) in their approach of an intersection. Since these behavioural parameters (e.g. speed reduction, pedalling behaviour) are important parameters when describing a test scenario, an observation study has been performed. This report describes the setup of such an observation study and the results of the study at 2 intersections with severe view-blocking obstruction in urban areas in the Netherlands. The velocity profiles of both cars and cyclists approaching the intersections were measured. Furthermore, for the cyclists, it was investigated what number of cyclists stops or continues pedalling when approaching the crossing, and in case they stopped pedal to determine the position of the legs (up-down or forward-rearward). The results show that all bicyclists reduce their speed, while some cars do not reduce speed at all near severe view blocking obstructions. More than 80% of the cyclist stopped pedalling when approaching the intersection. The majority of this group stopped pedalling with on leg up and the other leg down. Results about cyclist behaviour obtained in this study are used in the specification of the bicyclist target in WP3 [12].

BALCO is a six- and seven-degree-of-freedom trajectory simulation program based on the mathematical model defined by the NATO Standardization Recommendation 4618. The primary goal of BALCO is to compute high-fidelity trajectories for both conventional and precision-guided projectiles. The 6-DoF model is used to describe the motion of single rigid bodies. The 7-DoF model allows the description of a projectile which consists of two coaxial rigid bodies that can spin independently. Actuators such as isolated control surfaces, thrusters or internal roll control devices can optionally be attached to the rigid body. Controlling the state of these actuators offers a control authority on the trajectory. The verification of the BALCO results by comparison with reference codes is in progress. After the verification process, BALCO will be released as NATO Technical Shareable Software.

From 2018, AEB systems dedicated to avoid or mitigate passenger car-to-cyclist collisions will be considered in the safety assessment by Euro NCAP. To test such systems, appropriate equipment has been developed in the project CATS “Cyclist-AEB Testing System.” Moreover, the project dealt with setting up a proposal for the most relevant test scenarios. The objective of the project was to provide proof of the relevance of the proposed test scenarios and of the feasibility of practical implementation of the scenarios and test setup to Euro NCAP. Accidentology was used to determine the most common car-to-cyclist accident scenarios in the EU. The test setup has been developed to deal with the three most relevant scenarios: two scenarios for a cyclist crossing the path of the car (from the near side and the far side), and a longitudinal scenario in which the car drives into the cyclist from the rear. Requirements regarding a soft cyclist target have been set up. These consider target visual and radar characteristics as typical AEB systems and the applied sensors should recognize the target as a real cyclist on a bike. Moreover, requirements to the design of the testing system and target result from practical testing constraints: during testing, possible collisions between car and target should be mild without compromising the testing. A target and target propulsion system were constructed to meet these requirements. Accident data and data from observation studies were used to determine the parameter ranges in the proposed test matrix for the selected test scenarios. Together with car manufacturers and suppliers, a test matrix has been proposed and a testing setup including cyclist target has been built. In several test series, the test setup and the protocol were verified. Verification considered not only the capability of the protocol to distinguish between well-performing and less-performing AEB systems, but also the reproducibility and repeatability of the tests. Also the practical use of the system and the target were tested. The CATS project was unique in the fact that developments were performed in a consortium of 10 car manufacturers and 7 automotive suppliers, with BASt as review partner. This has stimulated the harmonization and acceptance of the protocol, target and test setup. The progress and intermediate results including the used methodology have been shared on a regular basis during the project with stakeholders in Europe, Japan and the USA. Euro NCAP already indicated to consider the results of the CATS project as the main input to draft the test protocol, including scenarios and target for Cyclist-AEB systems in 2018.

Several specially designed experimental techniques including an alternative test method have been developed for the evaluation of ceramic based armor. Armor grade ceramics and a range of combined materials have been tested using 7.62 AP rounds. Using the energy method [12] the dwell-time and total energy absorbed from the AP core were determined. In additional tests time-resolved fracturing of the ceramic tile (fragments) was recorded using high-speed video at one million frames per second. Also the particle size distribution of the fragments were measured in order to determine the total fracture surface area. The information provided by the results of all tests has resulted in an energy-based engineering model that allows calculation of the dwell-time, erosion and residual velocity of an AP-core. The model predicts the mass and velocity of residual AP cores rather well assuming a failure period during which the intact ceramic material transfers into a massively broken medium. The model does not require detailed mechanical properties of the ceramic materials. This reflects the difficulty within the ceramic armor research community to find a relation between mechanical properties and ballistic efficiency of armor ceramics. The developed engineering model creates a renewed understanding of the relevant phenomena, that could explain the ballistic efficiency of ceramic armor.

A framework is introduced to develop the theory of the adjoint method for models including both continuous and discrete dynamics. The basis of this framework consists of the class of impulsive linear dynamic systems. It allows extension of the adjoint method to more general models that include multirate subsystems or nonperiodic discrete events. Both the deterministic and the stochastic case are considered and the theory is applied to study the effect of uplinks on the performance of a guidance system.

This article proposes a safety check extension to Adaptive Cruise Control systems where the critical headway time is estimated in real-time. This critical headway time estimate enables automated reaction to crisis circumstances such as when a preceding vehicle performs an emergency brake. We introduce a method for critical headway approximation that can handle uncertainty in vehicle state, vehicle behaviour and communication in real-time. We validate our method using Monte Carlo simulations where we simulate emergency braking situations to ascertain the safe headway.

For the solution processing of organic photovoltaics on an industrial scale, the exclusion of halogenated solvents is a necessity. However, the limited solubility of most semiconducting polymer/fullerene blends in non-halogenated solvents results in ink formulations with low viscosities which poses limitations to the use of roll-to-roll compatible deposition processes, such as inkjet printing. We propose to add polystyrene as a rheological modifier to increase the viscosity of bulk heterojunction (BHJ) non-halogenated inks. The printing and performance of P3HT/PCBM photoactive layer inks are characterized as a function of polystyrene concentration and three different molecular weights. Addition of 1 wt% polystyrene provided a near two-fold gain in viscosity, with the largest viscosity gains coming from the polymer with the highest molecular weight. However, this coincided with greater viscoelastic behavior, which reduced the jetting performance of the inks. Differences in solvent compatibility of the polystyrene/P3HT/PCBM ternary blend resulted in phase separation upon layer drying, whereby polystyrene segregated to the layer-air interface to form an isolated domain or network like topology. Nevertheless, a 1.7-fold increase in dynamic viscosity was obtained for devices with printed BHJ layers containing polystyrene at the expense of a 20% reduction in OPV performance. The improved viscosity and good printing behavior achieved with small additions of polystyrene demonstrates its potential to overcome the limited viscosity resulting from typical non-halogenated ink formulations for semiconducting polymers. These results offer a step forward to the industrialization of inkjet printing as an effective deposition technique for functional layers of organic electronics.

Forensic analysis of explosions consists of determining the point of origin, the explosive substance involved, and the charge mass. Within the EU fP7 project Hyperion, TNO developed the Inverse Explosion Analysis (TNO-IEA) tool to estïmate the charge mass and point of origin based on observed damage around an explosion. In this paper inverse models are presented based on the two most frequently occurring and reliable sources of information: window breakage and building damage. The modets have been verified by applying them to the Enschede firework disaster and the Khobar tower attack. Furthermore a statistical method has been developed to combine the various types of data, in order to determine an overall charge mass distribution. In relatively open environments, like for the Enschede firework disaster, the models generate realistic charge masses that are consistent with values found in forensic literature. The confidence interval predicted by the IEA tool is however larger than presented in the literature for these specific cases. This is realistic due to the large inherent uncertainties in a generic tool. Furthermore, to our judgment often a too narrow range of charge masses is reported compared to the evidence. The IEA-models give a reasonable first order estimate of the charge mass in a densely built urban environment, such as for the Khobar tower affack. Due to blast shielding effects which are not taken into account in the IEA tool, this is usually an under prediction. To obtain more accurate predictions, the application of Computational Fluid Dynamics (CFD) simulations is advised. The TNO IEA tool gives unique possibilities to inversely calcutate the TNT equivalent charge mass based on a large variety of explosion effects and observations. The IEA tool enables forensic analysts, also those who are not experts on explosion effects, to perform an analysis with a largely reduced effort.

Stabilities of ITO-containing and ITO-free organic solar cells were investigated under simulated AM 1.5G illumination and under concentrated natural sunlight. In both cases ITO-free devices exhibit high stability, while devices containing ITO show degradation of their photovoltaic performance. The accelerated degradation under concentrated sunlight (of up to 20 suns) in ITO-containing devices was found to be reversible. Dark exposure of degraded samples can partly restore performance. A possible underlying mechanism for such a phenomenon is discussed.

The water sorption mechanism in thin nylon 6 films is studied by 1H NMR imaging and relaxometry. Experiments using D2O and H2O enable identification of polymer and water signal components during the uptake process. Tracking the mobility and size of polymer and water components gives new insights into the water sorption mechanism of nylon 6. 1H NMR imaging and relaxometry it is shown that water uptake is faster than plasticization. Water arrives first in the polymer matrix. After a while plasticization starts. Plasticization continues even when the nylon matrix is fully saturated. Further it is observed that the water mobility is still increasing, when the matrix is both saturated by water and plasticized. cop. 2015 Elsevier Ltd. All rights reserved.

Defects occurring during printing of the photoactive layer in organic solar cells lead to short-circuits due to direct contact between the PEDOT:PSS anode and metallic cathode. We provide a highly effective repair method where the defected zone with bare PEDOT:PSS is treated with aqueous sodium hypochlorite to locally disrupt the conductivity of PEDOT:PSS by over-oxidation. We demonstrate that even macroscopically large defects with a surface area of 10 mm2 can be repaired, restoring solar cell performance. In contrast, untreated defected solar cells exhibit a significantly increased leakage current and corresponding decrease in light-to-power conversion efficiency.

In this paper we introduce a microfluidic device ultimately to be applied as a wearable sweat sensor. We show proof-of-principle of the microfluidic functions of the device, namely fluid collection and continuous fluid flow pumping. A filter-paper based layer, that eventually will form the interface between the device and the skin, is used to collect the fluid (e.g., sweat) and enter this into the microfluidic device. A controllable evaporation driven pump is used to drive a continuous fluid flow through a microfluidic channel and over a sensing area. The key element of the pump is a micro-porous membrane mounted at the channel outlet, such that a pore array with a regular hexagonal arrangement is realized through which the fluid evaporates, which drives the flow within the channel. The system is completely fabricated on flexible polyethylene terephthalate (PET) foils, which can be the backbone material for flexible electronics applications, such that it is compatible with volume production approaches like Roll-to-Roll technology. The evaporation rate can be controlled by varying the outlet geometry and the temperature. The generated flows are analyzed experimentally using Particle Tracking Velocimetry (PTV). Typical results show that with 1 to 61 pores (diameter = 250 μm, pitch = 500 μm) flow rates of 7.3 × 10-3 to 1.2 × 10-1 μL/min are achieved. When the surface temperature is increased by 9.4 °C, the flow rate is increased by 130 %. The results are theoretically analyzed using an evaporation model that includes an evaporation correction factor. The theoretical and experimental results are in good agreement. cop. 2015, The Author(s).

To control tactile friction, that is the friction between fingertip and counter-body, the role of surface texture is required to be unveiled and defined. In this research, an experimental approach is used based on measuring tactile friction for directional texture (grooved channel) with varying depths. For a reference surface, in this current case a polished surface from the same tool steel is compared. The experimental results are analyzed to explain the observed skin friction behavior as a function of surface texture parameters, sliding direction and applied normal load. Sliding parallel to the groove length shows greater values in COF than sliding perpendicular to the groove direction. Furthermore, parallel sliding reveals a higher dependency of COF on the depth of the grooved channel texture than perpendicular sliding. Application of the two term friction model suggests that the adhesion component of friction has greater impact on parallel than perpendicular sliding direction. According to the observations, grooved channels are well suited to control skin friction in direction dependent sliding, for moderately loaded contact situations. This experimental research contributes to the haptic perception related research, and to the development of other direction-dependent surface structures for touch.

All-solution processed organic solar cells with inverted device architecture were demonstrated. Devices contain opaque bottom electrodes and semitransparent top electrodes, resulting in top illuminated devices. Nanoparticles-based Ag ink was used for inkjet printing both top and bottom electrodes. Semi-transparent top electrode consists of high conductivity PEDOT:PSS and Ag current collecting grids. Printed electrodes were compared to evaporated Ag electrodes (both top and bottom) and to ITO electrode in terms of transmittance, roughness, sheet resistance and device performance. All-solution processed devices with top illumination have average PCE of 2.4%, using P3HT:PCBM as photoactive layer. Top-illuminated devices with inverted architecture and bottom-illuminated device with conventional architecture, containing the identical layers, but in the reverse sequence, were then compared. Performed studies have revealed an advantage of inverted cell architecture. cop. 2015 Elsevier B.V. All rights reserved.

The PELE ammunition is characterized by a low-density filling material surrounded by a high-density brittle jacket material. An analytical model describing the fragmentation of this ammunition behind a target plate is presented. This model assumes uniaxial strain in the filling and uses the RankingeHugoniot relations to calculate the material state. In addition, shock and rarefaction wave interactions at the target free surface and the filling/target interface are accounted for, as well as the radial rarefaction originating from the jacket outer surface. This allows the calculation of the pressure evolution in the filling and the radial acceleration of the jacket at any axial position along the projectile. This model aims at improving previously published analytical models where the acoustic wave approximation was used and the wave interactions were neglected. Experimental results (Paulus and Schirm, 2006) are used to validate the analytical model for different target materials (aluminum and steel), target thicknesses (3 mm and 8 mm), filling materials (polyethylene and aluminum) and impact velocities (900 m/s to 3000 m/s). A qualitative comparison based on X-ray photographs reveals similar features between the model and the experiments, such as smaller and lighter fragments with a greater radial velocity at the front of the projectile compared to the fragment characteristics at the back of the projectile. A quantitative comparison based on the maximum radial velocity of the fragments shows on average a 20% difference between the analytical and experimental results for all impact conditions considered. Despite this difference, the analytical trend follows more closely the experimental one compared to the acoustic approximation especially at high impact velocities. In addition, the acoustic approximation fails to reproduce the jacket fragmentation pattern since the fragmentation length of the jacket is significantly under-predicted. A numerical simulation is also presented using the ANSYS Autodyn 14.0 software. The results show that the numerical and analytical pressure evolution in the filling and the radial velocity of the jacket are in very good agreement, verifying the uniaxial strain assumption. This agreement (together with the experimental agreement) thus suggests that the RankineeHugoniot relations, the wave interactions and the radial rarefaction wave must all be included in the model to adequately describe the fragmentation of the PELE ammunition behind a thin target plate.

To enable important scientific discoveries, ESO has defined a new ground-based telescope: the European Extremely Large Telescope (E-ELT). The baseline design features a telescope with a 39-m-class primary mirror (M1), making it the largest and most powerful telescope in the world. The M1 consists of 798 hexagonal segments, each about 1.4 m wide, but only 50 mm thick. In the last stages of the manufacturing process of these M1 segments, a nanometre-accurate metrology method is required for the M1 to be within specifications. The segments have to be measured on their whiffle-tree support structures with a nanometre-level uncertainty, with a total budget on form accuracy of 50 nm RMS for any segment assembly. In this paper a measurement machine design is presented based on a non-contact single-point scanning technique, capable of measuring with nanometre accuracy, being universal, fast and with low operational costs, providing suitable metrology for M1 segments. A tactile precision probe is implemented to be able to use the machine in earlier stages of the segment manufacturing process. In particular, this paper describes the design of the air-bearing motion system and the separate metrology system based on a moving Sintered Silicon Carbide tube, a fixed Zerodur metrology frame and an interferometric system for a direct and short metrology loop. Preliminary calculations show nanometre-level measurement uncertainty after calibration.

The success of a polymer/clay nanocomposite depends from a number of factors including the intrinsic properties of the clay, nanofiller dispersion and orientation, matrix/filler interactions, etc. This manuscript focuses on the effect of matrix/filler interphases on the final physical properties of nanocomposite. Two PA6/sepiolite nanocomposites masterbatches are prepared via in situ polymerisation and then diluted via melt-compounding to different filler contents: one based on unreactive pristine sepiolite and another based on reactive amino-silane functionalised sepiolite. This offers a unique comparison opportunity, in which only the latter nanocomposite has PA6 molecules grafted directly from the sepiolite clay. Both nanocomposites are characterised in terms of morphology, thermal behaviour, semi-static tensile tests and dynamic mechanical tests. Interestingly, the grafted-from nanocomposites presented an enhanced strain at break and work of fracture, up to 100% in correspondence of 5 wt.% of filler, which is explained by the presence of a "soft" interphase. cop. 2014 Elsevier Ltd. All rights reserved.

Measuring the quality of human health and well-being is one of the key growth areas in our society. Preferably, these measurements are done as unobtrusive as possible. These sensoric devices are then to be integrated directly on the human body as a patch or integrated into garments. This requires the devices to be very thin, flexible and sometimes even stretchable. An overview will be given of recent technology developments in this domain and concrete application examples will be shown.

Goal and scope of this study. DG MOVE has set out to assess various aspects of the tyre use and quality related to road safety, by means of the study “Study on some safety-related aspects of tyre use”. This report is the result of a tender and was granted to TNO (Netherlands) with TML (Belgium) as partner. The overall aim of the study is to propose policy options concerning the use of tyres for improvement of traffic safety. Centrally to this, is the idea that end users need to make the correct assessment in relation to the tyre condition in order to achieve a level of safety as high as possible. Within this context, the tyre condition is considered in relation to technical elements (tyre inflation pressure, tyre tread depth, tyre damage, tyre age, and meteorological influences) and one information element (driver awareness). The study addresses the topics of tyre usage and the impact on road safety (which are the potential safety improvements related to tyre usage from a technical perspective) and how can road users be supported to use tyres that have a better safety performance by policy options. The policy options are subject to a costbenefit analysis. Note that (apart from an accident analysis) the study does not perform new research or new tests, but instead reflects on existing studies from open data sources. By combining these insights and applying them on the study objectives, the relevant conclusions and recommendations are derived.

The trade-off between transparency and conductivity in transparent conductors used in optoelectronic devices is a major bottleneck towards higher device performances. Grid deposition on transparent conductive oxides was demonstrated using electrochemical deposition, which has the advantage of a high aspect ratio of 0.45 and the possibility to use very narrow lines. The sheet conductivity was increased more than two orders of magnitude at a transmittance loss of only a few percent. The figure of merit as defined by Haacke was improved with a factor of more than 50. © 2013 Elsevier B.V.

We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working with an extremely high resolution (larger than 150x150 correcting elements). We use focal-plane images collected successively, the corresponding phase-diversity information and numerically efficient algorithms to calculate the required wavefront updates. Different approaches are considered in numerical simulations, and laboratory experiments are shown to confirm the results. We compare the performances of the standard Gerchberg-Saxton algorithm, Fast and Furious (use of small-phase assumption to take advantage of linearisation) and recently proposed phase-retrieval methods based on convex optimisation. The results indicate that the calibration task is easiest with algorithms similar to Fast and Furious, at least in the framework we considered.

Laser-assisted chemical vapour deposition (CVD) growth is an attractive mask-less process for growing locally aligned carbon nanotubes (CNTs) in selected places on temperature sensitive substrates. The nature of the localized process results in fast carbon nanotube growth with high experimental throughput. Here, we report on the detailed investigation of growth kinetics related to physical and chemical process characteristics. Specifically, the growth kinetics is investigated by monitoring the dynamical changes in reflected laser beam intensity during growth. Benefiting from the fast growth and high experimental throughput, we investigate a wide range of experimental conditions and propose several growth regimes. Rate-limiting steps are determined using rate equations linked to the proposed growth regimes, which are further characterized by Raman spectroscopy and Scanning Electron Microscopy (SEM), therefore directly linking growth regimes to the structural quality of the CNTs. Activation energies for the different regimes are found to be in the range of 0.3-0.8 eV. © 2014 the Owner Societies.

Printed electronics, the manufacturing of electronic components on large, flexible, and low-cost substrates by printing techniques, can facilitate widespread, very low-cost electronics for consumer applications and disposable devices. New technologies are needed to create functional components in this field. This paper introduces a new method to create an all-additive printed switch on flexible substrate materials, such as polymer foils and paper substrates. The active layer of the switch component consists of neutral polyaniline (PANI), which can be doped by acid to induce a shift from a non-conductive to a conductive oxidation state. Monodisperse core–shell microcapsules containing an acidic aqueous core liquid were produced by a novel inkjet-based encapsulation technology. It was shown that unfavorable water evaporation from the microcapsules could be reduced by the addition of calcium chloride to the core liquid. A switch component was prepared, consisting of inkjet-printed interdigitated silver electrodes, PANI active layer and printed microcapsules. If an external pressure was applied, for instance with a finger, then the switch component changed its state from nonconductive to conductive with a simultaneous distinct color change. The results clearly demonstrate the feasibility of the presented approach to create either a visual or electronic signal for use in printed electronic applications.

We demonstrate the fabrication of an organic Ferroelectric Field Effect Transistor (FeFET) incorporating a ferroelectric gate dielectric made of nanostripes obtained by nanoimprinting poly(vinylidene fluoride-co-trifluoroethylene) over a layer of semiconducting poly(triarylamine). The imprinting process results in a decreased switching voltage for the ferroelectric, by a factor of ca. 1.5, resulting in a decreased operating voltage compared to a reference FeFET with a continuous ferroelectric layer. The transistor consists of a large number of nanostripe-gated transistors placed in parallel, which also offers interesting possibilities for a strong size reduction of organic FeFETs.

The presence of undetermined shunt pathways in CIGS solar cells can be severely limiting to the reproducibility of individual cell efficiency, both at lab-scale, and particularly in a roll-to-roll process. Here, a general model that describes the dark J-V characteristics of CIGS devices, accounting for three separate shunting pathways (Ohmic and non-Ohmic components, and a tunneling component), is presented. Excellent agreement between the model and experimental data is demonstrated throughout the temperature range 183 - 323K, whereas simpler models fail to accurate fit the data. To demonstrate the effectiveness of the model, a case study was carried out to investigate the cause of the large spread in efficiency in a single batch of CIGS cells. The model showed that the low efficiencies were entirely due to a higher prevalence of the three different shunt pathways, but not due to any degradation of the main junction. This methodology may therefore be used for rapid diagnosis of low (or inconsistent) efficiencies.

This paper describes the dynamics of capillary self-alignment of components with initial shift offsets from matching receptor sites. The analysis of the full uniaxial self-alignment dynamics of foil-based mesoscopic dies from pre-alignment to final settling evidenced three distinct, sequential regimes impacting the process performance. The dependence of accuracy, alignment time and repeatability of capillary self-alignment on control parameters such as size, weight, surface energy and initial offset of assembling dies was investigated. Finally, we studied the influence of the dynamic coupling between the degenerate oscillation modes of the system on the alignment performance by means of pre-defined biaxial offsets.