Search results for "threshold"
showing 10 items of 688 documents
Connectivity percolation in suspensions of hard platelets
2012
We present a study on connectivity percolation in suspensions of hard platelets by means of Monte Carlo simulation. We interpret our results using a contact-volume argument based on an effective single--particle cell model. It is commonly assumed that the percolation threshold of anisotropic objects scales as their inverse aspect ratio. While this rule has been shown to hold for rod-like particles, we find that for hard plate-like particles the percolation threshold is non-monotonic in the aspect ratio. It exhibits a shallow minimum at intermediate aspect ratios and then saturates to a constant value. This effect is caused by the isotropic-nematic transition pre-empting the percolation tran…
Improvement of solid state Er:YAG pulse laser performance for use in medicine
1999
The large quadratic electro-optic effect of PLZT ceramics allows to design small size modulators for the solid state infrared Er:YAG laser (lasing at (lambda) equals 2.94 micrometers - the most pronounced absorption band of water), which has found application in medicine for efficient ablation of hard and soft tissues. In the free-running mode, the Er:YAG laser emits spikes that form the pulse envelope with duration of 150 - 800 microsecond(s) . An extracavity PLZT 8.5/65/35 ceramics modulator (aperture of 4 X 6 mm2 and length of 18 mm) was used to obtain (Pi) -shaped segments with the rise and decay times less than 5 microsecond(s) . That allows to reduce considerably the fraction of the p…
Agalsidase alpha and hearing in Fabry disease: data from the Fabry Outcome Survey.
2006
Fabry disease is an X-linked lysosomal storage disorder characterized by multi-organ dysfunction, including hearing loss - mainly sensorineural. The recent introduction of enzyme replacement therapy (ERT) has resulted in improvements in renal and cardiac function, pain and quality of life. One study has also suggested small improvements in high-frequency hearing. In this paper, we study the effect of ERT on hearing in patients in the Europe-wide database - the Fabry Outcome Survey (FOS). Twenty-six patients in FOS had pure-tone audiometry performed up to 6 months before starting ERT with agalsidase alpha and after a median of 12 months of treatment. We assessed changes in hearing thresholds…
Variance Thresholded EMD-CCA Technique for Fast Eye Blink Artifacts Removal in EEG
2017
International audience; Eye blink (EB) artifacts generated during eye blinks often contaminate electroencephalogram (EEG) signal. Previously Empirical Mode Decomposition (EMD) and Canonical Correlation Analysis (CCA), hybrid EMD-CCA were developed for EB artifact removal in EEG. However, EMD restricts the hybrid algorithm for real time implementation due to its slow processing nature, hence the algorithm has to be enhanced so that it can be a viable solution for real-time EB artifact removal. In this research work, to avoid applying EMD repetitively as and when EB artifacts occur, a method to use EMD minimally is approached. A suitable EB artifact region is detected through a variance thres…
Die selektive invers-voltammetrische Bestimmung des Antimons in salzsauren Lösungen nach Lösungswechsel in einer einfachen Durchflußzelle
1987
The selective invers-voltammetric determination of antimony in a simple flow-through cell in hydrochloric acid solutions is described. After double medium exchange for post-electrolysis and inverse-voltammetric determination, the determination of antimony is possible in the presence of a large excess of copper, bismuth and other elements. The limit of determination is 0.2–0.3 ppb Sb, the reproducibility 1.5% (10 ppb Sb).
Study of percolation and clustering in supercritical water-CO2 mixtures
2008
The microscopic structure of supercritical water-CO(2) mixture is investigated by neutron diffraction experiments exploiting the isotopic HD substitution. The investigated water reach mixtures are in the liquidlike region of the phase diagram, according to the behavior of the radial distribution functions, yet a reduction of the average number of hydrogen bonds, compared to equivalent states of pure water, is found. As a consequence, the average dimension of water clusters is reduced and the system stays below the percolation threshold. These results, along with the shift of the main peaks of the site-site radial distribution functions, suggest that the excess volume in these supercritical …
Ionization Energies of ClO and Cl2O2
1996
The ionization energies of chlorine oxide (ClO) and its dimer (Cl2O2) have been measured using monochromatic synchrotron radiation in the 10−20 eV energy regime in combination with photoionization mass spectrometry. The threshold energy of ClO+ (m/z = 51) is found at 10.85 ± 0.05 eV, whereas the ionization threshold of Cl2O2+ (m/z = 102) occurs at 11.05 ± 0.05 eV. The experimental values are compared to results from ab initio calculations, where three stable isomers of Cl2O2 are considered: dichlorine peroxide (ClOOCl), chloryl chloride (ClClO2), and chlorine chlorite (ClOClO). The results indicate that the experimental threshold energy of Cl2O2+ is due to adiabatic ionization of ClOOCl. T…
Brain processing during mechanical hyperalgesia in complex regional pain syndrome: a functional MRI study.
2005
Complex Regional Pain Syndromes (CRPS) are characterized by a triad of sensory, motor and autonomic dysfunctions of still unknown origin. Pain and mechanical hyperalgesia are hallmarks of CRPS. There are several lines of evidence that central nervous system (CNS) changes are crucial for the development and maintenance of mechanical hyperalgesia. However, little is known about the cortical structures associated with the processing of hyperalgesia in pain patients. This study describes the use of functional magnetic resonance imaging (fMRI) to delineate brain activations during pin-prick hyperalgesia in CRPS. Twelve patients, in whom previous quantitative sensory testing revealed the presence…
Active spike transmission in the neuron model with a winding threshold manifold
2012
International audience; We analyze spiking responses of excitable neuron model with a winding threshold manifold on a pulse stimulation. The model is stimulated with external pulse stimuli and can generate nonlinear integrate-and-fire and resonant responses typical for excitable neuronal cells (all-or-none). In addition we show that for certain parameter range there is a possibility to trigger a spiking sequence with a finite number of spikes (a spiking message) in the response on a short stimulus pulse. So active transformation of N incoming pulses to M (with M>N) outgoing spikes is possible. At the level of single neuron computations such property can provide an active "spike source" comp…
Individual Variability and Average Reliability in Parallel Networks of Heterogeneous Biological and Artificial Nanostructures
2013
We simulate the collective electrical response of heterogeneous ensembles of biological and artificial nanostructures whose individual threshold potentials show a significant variability. This problem is of current interest because nanotechnology is bound to produce nanostructures with a significant experimental variability in their individual physical properties. This diversity is also present in biological systems that are however able to process information efficiently. The nanostructures considered are the ion channels of biological membranes, nanowire field-effect transistors, and metallic nanoparticle-based single electron transistors. These systems are simulated with canonical models…