Search results for "Pulse"

Analysis of the spatial distribution of free radicals in ammonium tartrate by pulse EPR techniques

2009

Using pulse electron paramagnetic resonance (EPR) on a series of l(+)-ammonium tartrate (AT) dosimeters exposed to radiations with different linear energy transfer (LET), we assessed the ability of pulse EPR spectroscopy to discriminate the quality of various radiation beams such as (60)Co gamma-ray photons, protons and thermal neutrons at various doses by analyzing the local radical distributions produced by the different beams. We performed two types of pulse EPR investigations: two-pulse electron spin echo decay obtained by varying the microwave power, and a double electron-electron resonance (DEER) study. Both methods provide information about the dipolar interactions among the free rad…

Strong-field molecular ionization: determination of ionization probabilities calibrated with field-free alignment

2006

International audience; We report an original optical method providing the probability of molecular ionization induced by femtosecond laser pulses. The approach consists of exploiting molecular alignment in order to extract reliable information about ionization. The cross defocusing technique implemented for this purpose reveals a sensitivity with respect to post-pulse alignment, as well as to free electron density induced by the ultra-short laser pulse. The analysis of the resulting signal gives thus access to absolute single-ionization probabilities calibrated through the degree of alignment provided that free electrons are mainly produced from single-ionization. The relevance of the meth…

Optimum pulse shape for minimum spectral occupancy in FSK signals

1984

The characteristics of a frequency shift keying (FSK) signal giving rise to maximum power within a prescribed frequency band are determined. The baseband pulse shape extends over any integer number of bit periods. An integral equation for the optimum pulse shape is derived and some simple properties of the solution are investigated. The equation has been solved for some values of the product of the prescribed band times the pulse duration and the signal shape is shown. Our results for the particular case of pulses only one bit period long are presented for purpose of comparison with results known in the literature. Plots of out-of-band power for some values of the prescribed band and of pul…

Pulsed Electric Field: Fundamentals and Effects on the Structural and Techno-Functional Properties of Dairy and Plant Proteins

2022

Dairy and plant-based proteins are widely utilized in various food applications. Several techniques have been employed to improve the techno-functional properties of these proteins. Among them, pulsed electric field (PEF) technology has recently attracted considerable attention as a green technology to enhance the functional properties of food proteins. In this review, we briefly explain the fundamentals of PEF devices, their components, and pulse generation and discuss the impacts of PEF treatment on the structure of dairy and plant proteins. In addition, we cover the PEF-induced changes in the techno-functional properties of proteins (including solubility, gelling, emulsifying, and foamin…

Design of dispersion-managed fiber systems for transmitting chirp-free Gaussian pulses

2008

International audience; We present a general method to analytically design a dispersion-managed (DM) fiber system for any desired fiber (dispersion, nonlinearity and losses) and pulse (width and energy) parameters. This analytical design allows one to transmit chirp-free Gaussian pulses (for very long distances) in almost all kinds of DM fiber systems that have appeared so far in the literature, including systems with dispersion map length greater, equal or shorter with respect to the amplification period.

Modified apparatus for voltage gradient gel electrophoresis.

1999

We built a modified version of voltage gradient gel electrophoresis system to correct distortions in nucleic acids electrophoretic migration patterns occurring at the edges of the gel when the original voltage gradient apparatus is used. The new device allows correct fractionation of nucleic acids also when electrophoresis is performed at high voltages.

Voltage gradient electrophoresis of nucleic acids on agarose gels.

1993

A very simple method is described which allows the separation of DNA molecules in a wide molecular weight range (from 0.6 to about 30 kb) in the same electrophoresis agarose gel. This is based on the achievement of a voltage gradient through a simple device consisting of a Plexiglas plate placed slantwise with respect to the gel surface plane, submerged in the electrophoretic running buffer. Further applications of our system are also described.

Enhanced hybridization labeling signals in Southern blotted DNAs fractionated with voltage gradient gel electrophoresis.

1998

An enhancement of hybridization labeling signals is demonstrated in Southern blotted DNAs, fractionated by voltage gradient gel electrophoresis. This enhancement is due to a reduced thickness of each single nucleic acid band in the gel as a consequence of the gradient effect, corresponding to an increased concentration of DNA per unit area.

Analysis of myxoma virus genome using pulsed-field gel electrophoresis

1996

A method is presented for the isolation of large quantities of myxoma virus DNA using pulsed-field gel electrophoresis (PFGE), and some preliminary applications of this technique.

2001

Eight strains of Taylorella equigenitalis were identified by a polymerase chain reaction using a primer pair specific to the 16S rDNA of T. equigenitalis. These eight strains were chosen because they had previously been shown to represent eight distinct genotypes by pulsed-field gel electrophoresis analysis after separate digestion of the genomic DNA with ApaI or NotI. The eight strains could be classified into six or seven types by random amplified polymorphic DNA analysis using different kinds of primers. Amplified rDNA restriction analysis after separate digestion with five restriction enzymes, including AluI and MboI, of the 1500 bp fragments of rDNA amplified by polymerase chain reacti…