Fiber-top cantilever:a new generation of micromachined sensors for multipurpose applications

Fiber-top cantilevers are new monolithic devices obtained by carving a cantilever out of the edge of a single-mode optical fiber. Here we report evidences of their potential impact as sensing devices for multipurpose applications

Joodse burgers in Apeldoorn: onteigening en rechtsherstel: Onderzoek in opdracht van gemeente Apeldoorn

Joodse burgers die de kampen overleefd hadden of na de bevrijding hun onderduik konden verlaten, keerden vaak terug naar hun vroegere woonplaats. Bij terugkeer moesten zij of, in veel meer gevallen, hun overlevende familieleden en nabestaanden, vaststellen dat het niet vanzelfsprekend was dat ze hun onteigende vastgoed terugkregen. Veel panden waren door de bezetter doorverkocht of hadden in ieder geval nieuwe bewoners. In veel gevallen was het een moeizaam en langdurig proces om aan de vereisten van het rechtsherstel te voldoen, of met de nieuwe eigenaar tot een ‘minnelijke schikking’ te komen. Dit rapport reconstrueert de rol van de gemeente Apeldoorn bij zowel de onteigening als bij de moeizame gang naar rechtsherstel.Political Culture and National IdentityHet historische en sociale weefsel van de stadCities, Migration and Global Interdependenc

Multimodal probe for optical coherence tomography epidetection and micron-scale indentation

We present a multimodal ferrule-top sensor designed to perform the integrated epidetection of Optical Coherence Tomography (OCT) depth-profiles and micron-scale indentation by all-optical detection. By scanning a sample under the probe, we can obtain structural cross-section images and identify a region-of-interest in a nonhomogeneous sample. Then, with the same probe and setup, we can immediately target that area with a series of spherical-indentation measurements, in which the applied load is known with a μN precision, the indentation depth with sub-μm precision and a maximum contact radius of 100μm. Thanks to the visualization of the internal structure of the sample, we can gain a better insight into the observed mechanical behavior. The ability to impart a small, confined load, and perform OCT A-scans at the same time, could lead to an alternative, high transverse resolution, Optical Coherence Elastography (OCE) sensor

Joodse burgers in Zutphen: onteigening en rechtsherstel: onderzoek in opdracht van gemeente Zutphen

Joodse burgers die de kampen overleefd hadden of na de bevrijding hun onderduik konden verlaten, keerden vaak terug naar hun vroegere woonplaats. Bij terugkeer moesten zij of, in veel meer gevallen, hun overlevende familieleden en nabestaanden, vaststellen dat het niet vanzelfsprekend was dat ze hun onteigende vastgoed terugkregen. Veel panden waren door de bezetter doorverkocht of hadden in ieder geval nieuwe bewoners. In veel gevallen was het een moeizaam en langdurig proces om aan de vereisten van het rechtsherstel te voldoen, of met de nieuwe eigenaar tot een ‘minnelijke schikking’ te komen. Dit rapport reconstrueert de rol van de gemeente Zutphen bij zowel de onteigening als bij de moeizame gang naar rechtsherstel.Het historische en sociale weefsel van de stadCities, Migration and Global InterdependencePolitical Culture and National IdentityJoods Nederlan

Mg/Ti multilayers: structural, optical and hydrogen absorption properties

Mg-Ti alloys have uncommon optical and hydrogen absorbing properties, originating from a "spinodal-like" microstructure with a small degree of chemical short-range order in the atoms distribution. In the present study we artificially engineer short-range order by depositing Pd-capped Mg/Ti multilayers with different periodicities and characterize them both structurally and optically. Notwithstanding the large lattice parameter mismatch between Mg and Ti, the as-deposited metallic multilayers show good structural coherence. Upon exposure to H2 gas a two-step hydrogenation process occurs, with the Ti layers forming the hydride before Mg. From in-situ measurements of the bilayer thickness L at different hydrogen pressures, we observe large out-of-plane expansions of the Mg and Ti layers upon hydrogenation, indicating strong plastic deformations in the films and a consequent shortening of the coherence length. Upon unloading at room temperature in air, hydrogen atoms remain trapped in the Ti layers due to kinetic constraints. Such loading/unloading sequence can be explained in terms of the different thermodynamic properties of hydrogen in Mg and Ti, as shown by diffusion calculations on a model multilayered systems. Absorption isotherms measured by hydrogenography can be interpreted as a result of the elastic clamping arising from strongly bonded Mg/Pd and broken Mg/Ti interfaces

Ferrule-top nanoindenter: An optomechanical fiber sensor for nanoindentation

Ferrule-top probes are self-aligned all-optical devices obtained by fabricating a cantilever on the top of a ferruled optical fiber. This approach has been proven to provide a new platform for the realization of small footprint atomic force microscopes (AFMs) that adapt well to utilization outside specialized laboratories [D. Chavan, Rev. Sci. Instrum. 81, 123702 (2010)10.1063/1.3516044; D. Chavan, Rev. Sci. Instrum. 82, 046107 (2011)10.1063/1.3579496]. In this paper we now show that ferrule-top cantilevers can be also used to develop nanoindenters. Our instrument combines the sensitivity of commercial AFM-based indentation with the ease-of-use of more macroscopic instrumented indenters available today on the market. Furthermore, the all-optical design allows smooth operations also in liquids, where other devices are much more limited and often provide data that are difficult to interpret. This study may pave the way to the implementation of a new generation user-friendly nanoindenters for the measurement of the stiffness of samples in material sciences and medical research. © 2012 American Institute of Physics

Associations of sedentary behaviour, physical activity, blood pressure and anthropometric measures with cardiorespiratory fitness in children with cerebral palsy

Background - Children with cerebral palsy (CP) have poor cardiorespiratory fitness in comparison to their peers with typical development, which may be due to low levels of physical activity. Poor cardiorespiratory fitness may contribute to increased cardiometabolic risk. Purpose - The aim of this study was to determine the association between sedentary behaviour, physical activity and cardiorespiratory fitness in children with CP. An objective was to determine the association between cardiorespiratory fitness, anthropometric measures and blood pressure in children with CP. Methods- This study included 55 ambulatory children with CP [mean (SD) age 11.3 (0.2) yr, range 6-17 yr; Gross Motor Function Classification System (GMFCS) levels I and II]. Anthropometric measures (BMI, waist circumference and waist-height ratio) and blood pressure were taken. Cardiorespiratory fitness was measured using a 10 m shuttle run test. Children were classified as low, middle and high fitness according to level achieved on the test using reference curves. Physical activity was measured by accelerometry over 7 days. In addition to total activity, time in sedentary behaviour and light, moderate, vigorous, and sustained moderate-to-vigorous activity (≥10 min bouts) were calculated. Results - Multiple regression analyses revealed that vigorous activity (β = 0.339, p<0.01), sustained moderate-to-vigorous activity (β = 0.250, p<0.05) and total activity (β = 0.238, p<0.05) were associated with level achieved on the shuttle run test after adjustment for age, sex and GMFCS level. Children with high fitness spent more time in vigorous activity than children with middle fitness (p<0.05). Shuttle run test level was negatively associated with BMI (r2 = -0.451, p<0.01), waist circumference (r2 = -0.560, p<0.001), waist-height ratio (r2 = -0.560, p<0.001) and systolic blood pressure (r2 = -0.306, p<0.05) after adjustment for age, sex and GMFCS level. Conclusions - Participation in physical activity, particularly at a vigorous intensity, is associated with high cardiorespiratory fitness in children with CP. Low cardiorespiratory fitness is associated with increased cardiometabolic risk

Two- and Three-Body Forces in the Interaction of He Atoms with Xe Overlayers Adsorbed on (0001) Graphite

In order to address the problem of three-body interactions in gas-surface scattering, the authors considered the collision of a He atom with the (0001) surface of graphite coated by a monolayer of Xe. To eliminate the uncertainties connected with errors in the two-body He-Xe interaction, the authors determined the latter by crossed-beam differential collision cross-section measurements performed at two energies (67.2 and 22.35 meV). These scattering data together with room-temperature bulk diffusion data are then fitted with a Hartree-Fock dispersion-type function to yield an interaction potential that explains most of the properties of this system within the experimental errors and represents an improvement on previously published He-Xe potentials. Helium diffraction measurements are then carried out from the Xe overlayer and the dependence of the specular intensity from the angle of incidence is carefully determined. Further, a He-surface potential is constructed by adding together the following terms: the He-Xe pairwise sum, the long-range He-(0001)C interaction, the three-body contribution generated by the Axilrod-Teller-Muto term, the so-called surface-mediated three-body interaction He-Xe-(0001)C first considered by A.D. McLachlan (Mol. Phys. 7, 381 (1964)), and finally a small correction which is meant to take into account the nonstationary nature of the surface. Using this potential, well-converged close-coupling scattering calculations are carried out, and their results compared with the data. In general, good agreement is obtained. The agreement can, however, be improved by (a) an increase of about 30% in the contribution of three-body forces, (b) the lowering of the He-graphite long-range attraction coefficient by about 15%, or (c) a reduction of the two-body interaction well depth of 1.6% (the experimental error) together with any combination of the factors under (a) and (b) reduced by an adequate amount. Elimination of the contribution of the graphite surface by studying Xe multilayers is hindered by the uncertainties in the 'thermal correction' (point (5) above) which, due to the multilayer increased 'softness', becomes an appreciable source of uncertainty