917 research outputs found
Conformal Magnetic Composite RFID for Wearable RF and Bio-Monitoring Applications
©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.10.1109/TMTT.2008.2006810This paper introduces for the first time a novel flexible magnetic composite material for RF identification (RFID) and wearable RF antennas. First, one conformal RFID tag working at 480 MHz is designed and fabricated as a benchmarking prototype and the miniaturization concept is verified. Then, the impact of the material is thoroughly investigated using a hybrid method involving electromagnetic and statistical tools. Two separate statistical experiments are performed, one for the analysis of the impact of the relative permittivity and permeability of the proposed material and the other for the evaluation of the impact of the dielectric and magnetic loss on the antenna performance. Finally, the effect of the bending of the antenna is investigated, both on the S-parameters and on the radiation pattern. The successful implementation of the flexible magnetic composite material enables the significant miniaturization of RF passives and antennas in UHF frequency bands, especially when conformal modules that can be easily fine-tuned are required in critical biomedical and pharmaceutical applications
Numerical integration of variational equations
We present and compare different numerical schemes for the integration of the
variational equations of autonomous Hamiltonian systems whose kinetic energy is
quadratic in the generalized momenta and whose potential is a function of the
generalized positions. We apply these techniques to Hamiltonian systems of
various degrees of freedom, and investigate their efficiency in accurately
reproducing well-known properties of chaos indicators like the Lyapunov
Characteristic Exponents (LCEs) and the Generalized Alignment Indices (GALIs).
We find that the best numerical performance is exhibited by the
\textit{`tangent map (TM) method'}, a scheme based on symplectic integration
techniques which proves to be optimal in speed and accuracy. According to this
method, a symplectic integrator is used to approximate the solution of the
Hamilton's equations of motion by the repeated action of a symplectic map ,
while the corresponding tangent map , is used for the integration of the
variational equations. A simple and systematic technique to construct is
also presented.Comment: 27 pages, 11 figures, to appear in Phys. Rev.
Tagged Arithmetic
A special tagged arithmetic system has been developed for use with FORTRAN pro grams written to process experimental data. The tagged arithmetic system carries a condition code with every numerical value and uses a special output to call attention to answers computed by using questionable input data. The questionable input data may result from instrumentation o r data recording system malfunctions, which can cause ill-conditioned calculations that result in process-time faults or error conditions.https://thekeep.eiu.edu/archives_armstead_publications/1000/thumbnail.jp
Multimode bolometer development for the PIXIE instrument
The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission
concept designed to measure the polarization and absolute intensity of the
cosmic microwave background. In the following, we report on the design,
fabrication, and performance of the multimode polarization-sensitive bolometers
for PIXIE, which are based on silicon thermistors. In particular we focus on
several recent advances in the detector design, including the implementation of
a scheme to greatly raise the frequencies of the internal vibrational modes of
the large-area, low-mass optical absorber structure consisting of a grid of
micromachined, ion-implanted silicon wires. With times the absorbing
area of the spider-web bolometers used by Planck, the tensioning scheme enables
the PIXIE bolometers to be robust in the vibrational and acoustic environment
at launch of the space mission. More generally, it could be used to reduce
microphonic sensitivity in other types of low temperature detectors. We also
report on the performance of the PIXIE bolometers in a dark cryogenic
environment.Comment: 10 pages, 7 figure
Aortic injuries following stents in bariatric surgery: our experience
Background: Due to the large number of laparoscopic sleeve gastrectomy (LSG) performed over the last decade, the management of the leak following LSG has been increasingly reported. The role of covered Self Expandable Metal Stents (cSEMS) for the treatment of the leak is still controversial because of the poor tolerance and high risk of complications. Objectives: The aim of the present study was to analyze the foregut wall perforation and aorta injuries, a very rare but potentially fatal complication, related to the treatment of the leak following LSG using cSEMS. Setting: Private hospital, France. Methods: An audit was conducted in 2 French tertiary bariatric endoscopic centers focusing on aortic injuries after cSEMS use for leak. We examined and classified the initial procedure, leak characteristics, primary endoscopic treatment, and outcome of endoscopic complication for each eligible case. Results: A total of 5 patients were identified with foregut wall perforation and aorta injuries. All stents were deployed for staple line leak following LSG. The recorded mortality in case of esophageal-aortic injuries related to cSEMS use was 80%. Conclusion: cSEMS are potentially effective tools for the management of foregut leaks in bariatric surgery. The biggest challenges with this approach are stent migration and poor quality of life. Caution is required due to the risk of fatal complications such as foregut wall perforation and aortic injury
Motor versus body awareness: Voxel-based lesion analysis in anosognosia for hemiplegia and somatoparaphrenia following right hemisphere stroke
This is the accepted manuscript version of the following article: Valentina Moro, Simone Pernigo, Manos Tsakiris, Renato Avesani, Nicola M. J. Edelstyn, Paul M. Jenkinson, and Aikaterini Fotopoulou, ‘Motor versus body awareness: Voxel-based lesion analysis in anosognosia for hemiplegia and somatoparaphrenia following right hemisphere stroke’, Cortex, Vol 83, pp. 62-77, first published online 15 Jul 2016. The version of record is available online at doi: http://dx.doi.org/10.1016/j.cortex.2016.07.001 Published by Elsevier. © Elsevier Ltd. All rights reserved.Anosognosia for hemiplegia (AHP) is informative about the neurocognitive basis of motor awareness. However, it is frequently associated with concomitant symptoms, such as hemispatial neglect and disturbances in the sense of body ownership (DSO). Although double dissociations between these symptoms have been reported, there is ongoing debate about whether they are manifestations of independent abnormalities, or a single neuro- cognitive deficit. We aimed to investigate the specificity of lesions associated with AHP by surpassing four, existing methodological limitations: (a) recruit a relatively large sample of patients (total N 1⁄4 70) in a multi-centre study; (b) identify lesions associated with AHP in grey and white matter using voxel-based methods; (c) take into account the duration of AHP and concomitant neglect symptoms; and (d) compare lesions against a control hemiplegic group, patients suffering from AHP and DSO, and a few, rare patients with selective DSO. Results indicated that acute AHP is associated with a wide network, mainly including: (1) the Rolandic operculum, (2) the insula and (3) the superior temporal gyri. Subcortically, damage mainly involved the basal ganglia and white matter, mostly the superior corona radiate, arcuate fasciculus and the part of the ventral, superior longitu- dinal fasciculus. Persistent symptoms were linked with wider damage involving fronto- temporal cortex and long white matter tracts. A shift in the latero-medial direction (mainly involving the basal ganglia and surrounding white matter) emerged when DSO was taken accounted for. These results suggest that while bodily awareness is processed by areas widely distributed across the brain, intact subcortical structures and white matter tracts may be necessary to support basic feelings of owning and controlling contralateral body parts. An accurate and ‘up-to-date’ awareness of our motor abilities, however, may rely also on intact processing in cortical areas which presumably allow higher-order in- ferences about the current state of the body.Peer reviewedFinal Accepted Versio
(2E,4E,6E)-3-Methyl-7-(pyren-1-yl)octa-2,4,6-trienoic acid
The title compound, C25H20O2, was synthesized by a Wittig reaction between triphenyl[1-(pyren-1-yl)ethyl]phosphonium bromide and ethyl (2E,4E)-3-methyl-6-oxohexa-2,4-dienoate, in the presence of n-butyl lithium, followed by saponification. It was obtained pure in the all-trans configuration following crystallization from ethyl acetate. The asymmetric unit contains two independent molecules (A and B), which are arranged almost parallel to each other within the crystal structure. The triene chain is not coplanar with the pyrene ring system, forming dihedral angles of 52.8 (1) and 42.2 (1)° for molecules A and B, respectively. Intermolecular hydrogen bonds between the carboxyl groups of the molecules link them into centrosymmetric pairs, AA and BB, each with the R
2
2(8) graph-set motif
Samples for 3rd Harmonic Magnetometry Assessment of NbTiN-Based SIS Structures
In the quest for alternative superconducting materials to bring accelerator cavity performance beyond the bulk niobium (Nb) intrinsic limits, a promising concept uses superconductor-insulator-superconductor (SIS) thin film structures that allows magnetic flux shielding in accelerator cavities to higher fields [1]. Candidate materials for such structures are NbTiN as the superconductor and AlN as the insulator. We have demonstrated high quality NbTiN and AlN deposited by reactive DC magnetron sputtering (DCMS), both for individual layers and multilayers. Interface quality has been assessed for bilayer stacks with 250 nm NbTiN layers and AlN thicknesses from 30 nm down to1 nm. These SIS structures show continued sharp interfaces with total average roughness under 2 nm. The Hfp enhancement of the films will be examined with a 3rd harmonic magnetometry. The system is being designed and built in a continuing collaboration with CEA Saclay. It can measure 25 to 50 mm samples on a temperature controlled stage. This contribution presents an overview of the design of the 3rd harmonic magnetometer and the material properties assessment of standalone films and multilayer nanostructures
Boxy/peanut/X bulges, barlenses and the thick part of galactic bars: What are they and how did they form?
Bars have a complex three-dimensional shape. In particular their inner part
is vertically much thicker than the parts further out. Viewed edge-on, the
thick part of the bar is what is commonly known as a boxy-, peanut- or X- bulge
and viewed face-on it is referred to as a barlens. These components are due to
disc and bar instabilities and are composed of disc material. I review here
their formation, evolution and dynamics, using simulations, orbital structure
theory and comparisons to observations.Comment: 21 pages, 7 figures, invited review to appear in "Galactic Bulges",
E. Laurikainen, R. Peletier, D. Gadotti, (eds.), Springe
Grupo focal como ferramenta para testes de aceitação com consumidores: o caso do flocão de milho fortificado.
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