88 research outputs found
A Broadband UHF Tag Antenna For Near-Field and Far-Field RFID Communications
The paper deals with the design of passive broadband tag antenna for Ultra-High Frequency (UHF) band. The antenna is intended for both near and far fields Radio Frequency Identification (RFID) applications. The meander dipole tag antenna geometry modification is designed for frequency bandwidth increasing. The measured bandwidth of the proposed broadband Tag antenna is more than 140 MHz (820–960 MHz), which can cover the entire UHF RFID band. A comparison between chip impedance of datasheet and the measured chip impedance has been used in our simulations. The proposed progressive meandered antenna structure, with an overall size of 77 mm × 14 mm × 0.787 mm, produces strong and uniform magnetic field distribution in the near-field zone. The antenna impedance is matched to common UHF chips in market simply by tuning its capacitive and inductive values since a perfect matching is required in the antenna design in order to enhance the near and the far field communications. Measurements confirm that the designed antenna exhibits good performance of Tag identification for both near-field and far-field UHF RFID applications
Theoretical and experimental study of the orientational ordering in the field-induced intermediaite phase from the SmC*FI2 phase in chiral smectic liquid crystals
Under an electric field, chiral smectic liquid crystals transit usually to
the unwound SmC* phase where the helical structure is completely unrolled.
Sometimes the sample transits initially towards an intermediate polar state
before the total destruction of the helix. Based on the extension of the H-T
model, a theoretical study of these field-induced phase transitions was carried
out. Two hypotheses of the dynamics that give rise to the appearance of the
intermediate phase have been discussed. The results of a numerical analysis
confirm the known experimental results; the intermediate phase has a
three-layer periodicity structure
Extension of the Hamaneh - Taylor model using the macroscopic polarization for the description of chiral smectic liquid crystals
Chiral smectic liquid crystals exhibit a series of phases, including
ferroelectric, antiferroelectric and ferrielectric commensurate structures as
well as an incommensurate SmCalpha phase. We carried out an extension of the
phenomenological model, recently presented by M. B. Hamaneh and P. L. Taylor,
based upon the distorted clock model
Comparative Study of Human and Automated Screening for Antinuclear Antibodies by Immunofluorescence on HEp-2 Cells
Background: Several automated systems had been developed in order to reduce inter-observer variability in
indirect immunofluorescence (IIF) interpretation. We aimed to evaluate the performance of a processing system in
antinuclear antibodies (ANA) screening on HEp-2 cells.
Patients and Methods: This study included 64 ANA-positive sera and 107 ANA-negative sera that underwent IIF on two
commercial kits of HEp-2 cells (BioSystems® and Euroimmun®). IIF results were compared with a novel automated
interpretation system, the “CyclopusCADImmuno®” (CAD).
Results: All ANA-positive sera images were recognized as positive by CAD (sensitivity = 100%), while 17 (15.9%) of the
ANA-negative sera images were interpreted as positive (specificity = 84.1%), =0.799 (SD=0.045). Comparison of IIF
pattern determination between human and CAD system revealed on HEp-2 (BioSystems®), a complete concordance in
6 (9.37%) sera, a partial concordance (sharing of at least 1 pattern) in 42 (65.6%) cases and in 16 (25%) sera the
pattern interpretation was discordant. Similarly, on HEp-2 (Euroimmun®) the concordance in pattern interpretation was
total in 5 (7.8%) sera, partial in 39 (60.9%) and absent in 20 (31.25%). For both tested HEp-2 cells kits agreement was
enhanced for the most common patterns, homogenous, fine speckled and coarse speckled. While there was an issue in
identification of nucleolar, dots and nuclear membranous patterns by CAD.
Conclusion: Assessment of ANA by IIF on HEp-2 cells using the automated interpretation system, the
“CyclopusCADImmuno®” is a reliable method for positive/negative differentiation. Continuous integration of IIF images
would improve the pattern identification by the CAD
BAFF and Graves' disease
This a dataset summarizing data of BAFF level and polymorphisms investigation in Graves' disease patientsTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV
Electronic spectra of cationic PAH and PAH clusters
An experiment designed for measuring the electronic spectra of PAH cations and PAH
cluster cations has been set up, which is briefly described. The photodissociation
spectra, reflecting the absorption spectra, of 2-methyl-naphthalene dimer cation have been
recorded in the spectral ranges corresponding to the transitions from the ground state to
both the excited charge resonance state and the first allowed local electronic excitation
state
Synthesis, characterisation and behaviour under a field of a chiral smectic liquid crystal
The C12HH compound has been synthesised and the phase transition temperatures were obtained by combining several experimental techniques. This compound exhibits in volume all of the tilted smectic phases except the SmC* phase and presents a large SmC* range. The experimental results show unexpected behaviour in planar cell capacitors: (i) compared with the bulk, the SmC* range extends to lower temperature where it coexists with another phase; this demixing phenomenon is not due to a thickness effect but probably induced by a polarisation effect; (ii) the unwinding process of the ferroelectric SmC* phase occurs via two steps with an intermediate state (or phase). The E – T diagram of C12HH has been established except in the region where the coexistence occurs
Speed and current control of permanent magnet synchronous motor drive using IMC controllers
The paper describes a current and speed control of the permanent magnet synchronous motor with vector control. For a current and speed controller, the Internal Model Control (IMC) method was chosen for its good tracking capability and demands on the controllers. A short analysis of the IMC method for design of the current and speed controller has been made. The paper contains mathematical description of the IMC controller design. Simulation and experimental results of the vector controlled AC drive with interior permanent magnet synchronous motor are shown to present features of the current and speed controller.Web of Science12410
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