In this paper, we study the behavior of immune memory against antigenic mutation. Using a dynamic model proposed by one of the authors in a previous study (A. de Castro [Phys. J. Appl. Phys. 33, 147 (2006) and Simul. Mod. Pract. Theory. 15, 831 (2007)]), we have performed simulations of several inoculations, where in each virtual sample the viral population undergoes mutations. Our results suggest that the sustainability of the immunizations is dependent on viral variability and that the memory lifetimes are not random, what contradicts what was suggested by Tarlinton et al. [Curr. Opin. Immunol. 20, 162 (2008)]. We show that what may cause an apparent random behavior of the immune memory is the antigenic variability.

The optimal sinusoidal excitation of an ultrasonic transducer requests a knowledge of the frequency and the impedance of the used ceramic. These parameters, that vary during the application, depend on the characteristics of the transducer but also on the acoustic load of the propagation medium. In the search for an adaptive excitation, we propose the design of a digital generator assuring the functions of automatic tuning and impedance matching. The design uses the Butterworth-Van Dycke model of pizoelectric ceramics. The method of determination and identification of the model parameters is presented and applied on three different transducers. The negative feedback of the generator is carried out by the signal measured on the transducers. The dynamic voltage being very variable, the output resistor of the driver is controlled by transducer impedance. This feedback control allows the stability of the output voltage to a constant value whatever the frequency and the medium is. A Simulink® model of the regulation loop shows that the frequency tuning could be realized by exploiting the command signal of the driver resistance. The precision and the stability of the feedback system are tested for frequencies between 1 to 3 MHz.

Since the detection of nanoparticles is a major issue in nano sciences, we have developed two instruments for the fast imaging of individual nano objects. The first one is based on a spatial modulation of the sample using an incoherent dark field illumination and a multiplexed lock in detection. The second instrument uses digital heterodyne holography. Both instruments make it possible to achieve a high signal-to-noise ratio and therefore to detect very low signal.

Electron beams with a particle energy of typically 12 keV are used for collisional excitation of dense gases. The electrons are sent through ceramic membranes of only 300 nm thickness into gas targets. Excimer light emission from the pure rare gases and from gas mixtures are studied for the development of brilliant VUV and UV light sources. The application of the technology for gas kinetic studies is described and its potential for building very small electron beam pumped lasers is discussed.

The kinetic of the hydroxyl radical is studied in N2/O2/H2O mixtures with small amounts of acetone or isopropyl alcohol (0.5%). The radical density is measured in absolute value in the afterglow of a photo-triggered discharge, which generates an homogeneous transient non-equilibrium plasma, using a time resolved absorption measurement method. For dry mixtures, experimental results are compared to predictions of a self-consistent 0D discharge and kinetic model. It is shown that dissociation of the VOCs through quenching collisions of nitrogen metastable states plays an important role in the production of OH. Measurements can not be explained looking only at the oxidation of acetone or IPA by the oxygen atom. This result is reinforced by experimental results about the OH density in wet mixtures, with or without VOCs, compared to dry ones.

The permanent operation of a 3 axes SQUID magnetometer in the LSBB below 550 m of calcite rock is a unique system of magnetic observation: a rejection rate better than 3 fT/$\surd $Hz over 40 Hz. The observation of magneto-ionosphere responses to P wave emissions both at the epicentre and at their arrival at LSBB for earthquakes of magnitude larger than 3 is reported. A simple model predicts the starting time of these events. These results are compared with those provided by Doppler sounders for ionosphere responses to Rayleigh waves.

This paper describes optical instrumentation devoted to vibration analysis. Two strategies based on digital Fresnel holography are presented. The first, called time-averaging consists in the numerical reconstruction of the hologram after recording with an exposure time much greater than the vibration period. Thus, the holograms are amplitude modulated by a Bessel function. The last strategy, using a pulsed regime, allows the reconstruction of the full movement of the vibration, even if it exhibits very high amplitude. Experimental results presented in this paper concern the study of the vibrations of a clarinet reed under free and forced oscillation regimes.

NO oxidation by simultaneous action of a dielectric barrier discharge and TiO2 photocatalyst was investigated as a function of the inlet gas composition (NO, O2, N2) and the input energy. Concentrations of various NOx species and ozone in the outlet were detected by the optical absorption spectroscopy. Higher content of O2 (10% and higher) increased the removal of NO and resulted in a higher output of N2O5. TiO2 coating on a reactor electrode resulted in the time-depending oxidation of NO. Initially the concentration of untreated NO fell below the level achieved without TiO2 but after few minutes the positive effect of TiO2 diminished. The initial decrease in NO level due to the presence of TiO2 coating is explainable by surface reactions of NO species and absorbed oxygen. After few minutes, the surface states responsible for the initial removal of NO saturated and the effect of TiO2 vanished.

In this study, the efficiency of different types of pulsed electrical discharges for the removal of organic pollutants from wastewater has been determined. Three discharge types, either in the water volume or in close proximity to the water surface are studied. The production of hydrogen peroxide in pure water, and the degradation of two typical pollutants (4-chlorophenol and 4-nitrophenol) is measured together with the amount of electrical energy dissipated in discharges. It is shown that the energy yield for the degradation of organic pollutants, expressed in terms of degraded moles per Joule, strongly depends on the discharge type. The highest efficiency is obtained with pulsed corona discharges in humid air above the water surface. A lower efficiency is found with spark discharges in water, and the less efficient process is constituted by streamer discharges in water. The influence of ferrous ions added to solutions is also very different according to the discharge type. This helps to get a better understanding of the degradation processes involved with the different discharge types.

This paper deals with the development and application of in vivo spatially-resolved bimodal spectroscopy (AutoFluorescence AF and Diffuse Reflectance DR), to discriminate various stages of skin precancer in a preclinical model (UV-irradiated mouse): Compensatory Hyperplasia CH, Atypical Hyperplasia AH and Dysplasia D. A programmable instrumentation was developed for acquiring AF emission spectra using 7 excitation wavelengths: 360, 368, 390, 400, 410, 420 and 430 nm, and DR spectra in the 390–720 nm wavelength range. After various steps of intensity spectra preprocessing (filtering, spectral correction and intensity normalization), several sets of spectral characteristics were extracted and selected based on their discrimination power statistically tested for every pair-wise comparison of histological classes. Data reduction with Principal Components Analysis (PCA) was performed and 3 classification methods were implemented (k-NN, LDA and SVM), in order to compare diagnostic performance of each method. Diagnostic performance was studied and assessed in terms of sensitivity (Se) and specificity (Sp) as a function of the selected features, of the combinations of 3 different inter-fibers distances and of the numbers of principal components, such that: Se and Sp≈ 100% when discriminating CH vs. others; Sp≈ 100% and Se> 95% when discriminating Healthy vs. AH or D; Sp≈ 74% and Se≈ 63% for AH vs. D.

Two DBD torch designs were used to investigate coating and surface functionalization of small particles. One had an annular discharge gap between coaxial quartz tubes, the second, suited for high throughput, used external shell electrodes on opposite sides of a quartz tube. Several discharge sections could be used in flow direction, with intermediate ports for particle and/or monomer injection. Both torches were operated by a sinusoidal high voltage (13 kV, 20 kHz). The coaxial torch always showed a filamentary discharge, while the shell-electrode design in He also produced diffuse glow discharges. A variety of different precursors and dielectric as well as metallic particles of nanometer or micrometer diameter were used.

The present work is an investigation of the chemical composition and growth profile of an hydrogenated amorphous carbon nitride film (a-CN:H) deposited by atmospheric pressure Townsend discharge in C2H4/N2. Various surface characterization techniques were used to evaluate the coatings properties (X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Profilometry, Scanning Electron Microscopy). The coating obtained presented a high N/C ratio and a high concentration of N-functionalities. The results revealed two different growth mechanisms depending on the residence time of the precursor molecules; at first, the growth is mainly due to radicals then a powder formation mechanism appears, therefore leading to different chemical composition and surface properties.

The establishment of corona discharges close to a point electrode under both negative and positive high voltage in normal liquid helium (LHe) at 4.2 K is reported. The experiments were carried out at constant temperature and pressures ranging from 0.1–10 MPa. Visible luminescence emitted from the zone close to the tip revealed lines due to excited He atoms and molecules. The molecular luminescence showed hot band emissions with vibrational levels populated up to v=2. Rotational temperatures of 800 K were estimated showing that the excitations do not thermalise. With increasing pressure the lines shifted to shorter wavelengths and became broader. The magnitude of the increase in width deviated from what is expected from the gas phase and from classical line broadening theory and rather showed similarities to the behavior of bubbles in LHe. The detailed analysis of the rotational line intensity distribution revealed the presence of an additional radiator at the long wavelength side of molecular bands that we tentatively assign to “red satellite” emission. For corona discharges with positive tip polarities both atomic and molecular lines showed “red satellite" bands with much larger intensity than for negative polarity. The origin of the red satellite and the polarity dependence is unclear yet.