Search results for "pulse"
showing 10 items of 1508 documents
INTEGRAL observations of the peculiar BeX System SAX J2103.5+4545
2004
We present an INTEGRAL data analysis of the X-ray transient \object{SAX J2103.5+4545} during two outbursts detected in December 2002. The INTEGRAL coordinates and error circle agree with the position of the recently proposed optical counterpart. A power-law plus cut-off model provided a good fit to the 4-150 keV spectrum yielding a photon index of 1.0+-0.1, a cut-off energy E_cut=7.6+-2.0 keV and a folding energy E_fold=30.9+-2.5 keV. The X-ray luminosity in the 4-150 keV energy range was found to be 6.0x10^36 erg/s, assuming a distance of 6.5 kpc. This luminosity, together with the derived photon index, indicate that the source is in a bright state. A 354.9$+-0.5 second pulse period is mea…
Experimental and robust modeling approach for lead(II) uptake by alginate gel beads: influence of the ionic strength and medium composition.
2014
Abstract Systematic kinetic and equilibrium studies on the lead ions removal ability by Ca-alginate gel beads have been performed by varying several internal parameters, namely, number of gel beads, nature and composition of the ionic medium and pH, which allowed us to model a wastewater in order to closely reproduce the composition of a real sample. Moreover, the effects brought about the different ionic species present in the reacting medium have been evaluated. Differential Pulse Anodic Stripping Voltammetry (DP-ASV), has been systematically used to perform kinetic and equilibrium measurements over continuous time in a wide range of concentration. Kinetic and equilibrium data have been q…
Reflexionsakustische Lagebestimmung von Trachealkanülen
1997
Non-invasive acoustic airway monitoring was evaluated in an experimental study. Recording amplitude and travel time of acoustic pulse response, an area-distance function of the cross sectional dimensions of the endotracheal tube and the adjacent airway was calculated to obtain an acoustic pattern of the airway. Measurements on models and excised human cadaver lungs were performed to discover whether displacement or obstruction of the artificial airway can be detected in the acoustic equivalent. Regression analysis revealed a close correlation between displacement of tracheostomy tubes and the shifting of the acoustic area-distance function (corr. coeff. 0.97-1). Dispersion analysis confirme…
Femtosecond up-conversion technique for probing the charge transfer in a P3HT : PCBM blend via photoluminescence quenching
2009
We report on an experimental study of the charge transfer dynamics in a P3HT : PCBM blend by means of a femtosecond fluorescence up-conversion technique. Using two-photon excitation we probe the exciton dynamics in P3HT and a P3HT : PCBM blend with a weight ratio of 1 : 1 at excitation densities of up to 6 × 1018 cm−3. In both samples we find strongly nonexponential decay traces compatible with (i) diffusion-limited exciton–exciton annihilation and (ii) diffusion-limited donor–acceptor charge transfer in the polymer blend. Additionally, our results indicate that in the P3HT : PCBM blend about 50% of the photogenerated excitons undergo a prompt charge transfer process on a time scale of abou…
Exchange stiffness in the Co2FeSi Heusler compound
2009
Using Brillouin light scattering spectroscopy, we determine the spin-wave exchange stiffness D and the exchange constant A for thin films of the full Heusler compound Co2FeSi prepared by pulsed laser deposition. The thermal spin-wave spectra were measured in various magnetic fields, for different transferred spin-wave momenta, and for different film thicknesses. Fitting the observed spin-wave frequencies, we find an extraordinarily large value of
Glycoprotein and ganglioside changes in human trophoblasts after exposure to pulsed doppler ultrasound
1995
Changes in glycoprotein and ganglioside composition in human trophoblasts (eighth week of gestation) after in vitro exposure to pulsed Doppler ultrasound (pulse duration 1.22 microseconds; repetition frequency 11.1 kHz; center frequency 4 MHz; ISPPA = 175.5 W/cm2; ISPTA = 0.59 W/cm2) were investigated. Evacuated trophoblasts were divided in two halves and insonated for 10 min on top of a 6-cm layer of 5% gelatin in 50-mL tubes (Falcon) at 37 degrees C. One half of each trophoblast was sham insonated and served as an internal control. After insonation trophoblasts were maintained at 37 degrees C for 24 h. Glycoproteins were detected using alpha-D-mannose specific lectins from Galanthus nival…
Acoustic monitoring of the artificial airway — experimental results
1997
Non-invasive acoustic airway-monitoring was evaluated in an experimental study. Recording amplitude and travel time of acoustic pulse response, an acoustic pattern of airway's geometry was then calculated. Measurements on models and excised human cadaver lungs were performed to discover whether displacement or obstruction of the artificial airway could be detected by its acoustic equivalent. Regression analysis revealed a close correlation between displacement of tracheostomy tubes and the shifting of the acoustic area-distance function (corr. coeff.: 0.97-1) and an adequate correlation between acoustic and planimetrical determination of cross-sectional area within the tubes (corr. coeff.: …
Aequorin-expressing yeast emits light under electric control
2011
In this study, we show the use of direct external electrical stimulation of a jellyfish luminescent calcium-activated protein, aequorin, expressed in a transgenic yeast strain. Yeast cultures were electrically stimulated through two electrodes coupled to a standard power generator. Even low (1.5. V) electric pulses triggered a rapid light peak and serial light pulses were obtained after electric pulses were applied periodically, suggesting that the system is re-enacted after a short refraction time. These results open up a new scenario, in the very interphase between synthetic biology and cybernetics, in which complex cellular behavior might be subjected to electrical control.
FPGA Implementation of an Adaptive Filter Robust to Impulsive Noise: Two Approaches
2011
Adaptive filters are used in a wide range of applications such as echo cancellation, noise cancellation, system identification, and prediction. Its hardware implementation becomes essential in many cases where real-time execution is needed. However, impulsive noise affects the proper operation of the filter and the adaptation process. This noise is one of the most damaging types of signal distortion, not always considered when implementing algorithms, particularly in specific hardware platforms. Field-programmable gate arrays (FPGAs) are used widely for real-time applications where timing requirements are strict. Nowadays, two main design processes can be followed for embedded system design…
Efficacy of 595- and 1319-nm pulsed dye laser in the treatment of acne vulgaris: a narrative review
2020
Acne is one of the commonest problems of adolescence with almost half of the patients experiencing persistence into adulthood. Pulsed dye lasers (PDL) with wavelengths of 585 and 595 nm targeting hemoglobin have been used for the treatment of this condition and its sequelae. Recent introduction of PDL with a higher wavelength of 1319 nm has been reported to offer some benefit to acne patients. We reviewed the literature on the use of 595-nm and 1319-nm PDL in the management of acne. A PubMed literature search for search terms "pulsed dye laser," "acne laser therapy," "light therapy for acne," "595 nm and acne," "1319 nm and acne" was done. Studies, series and case reports were included. The…