Report 1 PHIN-CARE-JRA2-WP3 Second Task: Pulse Shaping

This report presents the activity developed on laser pulse shaping argument in years 2004-2005 by Milano-INFN within the framework of CARE /JRA2 \Charge production with Photoinjectors" second task \Pulse Shaping". A dedicated laser system with the relative diagnostic tools have been developed. A liquid crystal programmable spatial light modulator(LCP-SLM) shaper have been studied and set for the generation of di®erent waveforms. The shaper is integrated in the laser system for an automatic generation of the target waveforms via the insetion of a computer which drives the system through the developed software. The system can be programmed to generate any target waveform compatible with the spectral bandwidth of the laser system and some exemples are presented. The following issues are treated: (i) the operation stability as function of perturbations of the set-up parameters, (ii) the design of the shaper for the SPARC project, (iii) a new shaper concept for the generation of long target waveforms and (iiii) the rectangular pulse generation at the second harmonic

Electron Emission from Ferroelectric/Antiferroelectric Cathodes Excited by Short High-Voltage Pulses

Un-prepoled Lead Zirconate Titanate Lanthanum doped-PLZT ferroelectric cathodes have emitted intense current pulses under the action of a high voltage pulse of typically 8 kV/cm for PLZT of 8/65/35 composition and 25 kV/cm for PLZT of 4/95/5 composition. In the experiments described in this paper, the exciting electric field applied to the sample is directed from the rear surface towards the emitting surface. The resulting emission is due to an initial field emission from the metal of the grid deposited over the emitting surface with the consequent plasma formation and the switching of ferroelectric domains. These electrons may be emitted directly form the crystal or from the plasma. This emission requires the material in ferroelectric phase. In fact, PLZT cathodes of the 8/65/35 type, that is with high Titanium content, showing ferroelectric-paraelectric phase sequence, emit at room temperature, while PLZT cathodes of the 4/95/5 type, that is with low Titanium content, having antiferro-ferro-paraelectric phase sequence, emit strongly at a temperature higher than 130°C

Nano-antenna array for high efficiency sunlight harvesting

none5noSolar rectennas are promising devices for energy harvesting. Capability of rectennas to convert incident light into useful energy depends on the antenna efficiency, that is the ratio between the power transferred to the load vs the incoming power. In this work, we first emphasize that for the efficiency to be calculated accurately, antennas need to be treated as receiving devices, not as transmitting ones. Then, we propose an arrangement of antennas that differs from those published so far in three respects: (1) the proposed arrangement is formed by an array of nano-antennas with sub-wavelength inter-element spacing, (2) it comprises a reflecting mirror, and (3) it allows for dual polarization operation. Through numerical simulations, we show that the small lattice pitch we use is responsible for frequency flattening of the lattice impedance over the whole solar spectrum, eventually allowing for excellent matching with the antennas’ loads. Also, the small pitch allows for a smooth dependence of the receiving efficiency on the angle of incidence of sunlight. Finally, we show numerically that the reflecting mirror also allows for an almost complete cancellation of light scattered by the receiving antennas. The final result is a polarization insensitive receiving theoretical efficiency larger than 70% over the whole 300-3000 nm spectral range, with a less than 10% energy wasting due to back-scattering of sunlight.openMidrio M.; Pierantoni L.; Boscolo S.; Truccolo D.; Mencarelli D.Midrio, M.; Pierantoni, L.; Boscolo, S.; Truccolo, D.; Mencarelli, D

Analysis of navigation pattern in the sport of rowing

The effect of weather and environmental conditions on sports has been extensively studied over the last few years (Pezzoli et al., 2010). Based upon the studies of Lobozewicz (1981) and of Kay and Vamplew (2002), Pezzoli and Cristofori (2008) have studied the impact of some specific environmental parameters over different sports using a particular impact index divided into five classes. This analysis clearly shows that most of the outdoor sport activities are strongly influenced by the variation of meteorological parameters. However the impact of meteorological conditions on outdoor sport activities has not yet been extensively studied. The aim of this research is to show that an accurate assessment of wind and wave parameters enables decisive improvements in both training and race strategy planning. Furthermore this analysis provide a very innovative working method for the applied sport research. The work has been based on in-situ measurements of both environmental and performance parameters (wind direction, wind velocity, boat speed and stroke rate) made over different classes and in different race conditions during the 2009 FISA World Championship (Poznan, Poland). In particular a detailed environmental analysis was performed by measuring the wind direction, the wind speed and by evaluating the significant wave height and the wave peak period for each class during the semi-final phase and the final phase. It should be noted that, since wind is a key parameter affecting not only the boat speed but also the race strategy, the assessment of the wind velocity and of the wind direction has been made in connection with the boat movement. The comparison between coupled wind-wave data, boat speed and stroke rate evidently demonstrates that only crews that managed the adaption to changing in the environmental conditions from semi-final to final phase of the race, were able to get better results. References Kay, J., & Vamplew, W. (2002) Weather beaten: sport in the British climate. London: Ed. Mainstream Publishing. Lobozewicz, T. (1981) Meteorology in sport. Frankfurt: Ed. Sportverlag. Pezzoli, A,, Moncalero, M., Boscolo, A., Cristofori, E., Giacometto, F., Gastaldi, S., & Vercelli, G. (2010) The meteo-hydrological analysis and the sport performance: which are the connections? The case of the XXI Winter Olympic Games, Vancouver 2010, Journal of Sports Medicine and Physical Fitness, 50: 19-20. Pezzoli, A., & Cristofori, E. (2008) Analisi, previsioni e misure meteorologiche applicate agli sport equestri, in: 10th Congress "New findings in equine practices, Druento: Centro Internazionale del Cavallo Ed., p.38-4

Time domain add-drop multiplexing scheme enhanced using a saw-tooth pulse shaper

We experimentally demonstrate the use of saw-tooth optical pulses, which are shaped using a fiber Bragg grating, to achieve robust and high performance time-domain add-drop multiplexing in a scheme based on cross-phase (XPM) modulation in an optical fiber, with subsequent offset filtering. As compared to the use of more conventional pulse shapes, such as Gaussian pulses of a similar pulse width, the purpose-shaped saw-tooth pulses allow higher extinction ratios for the add and drop windows and significant improvements in the receiver sensitivity for the dropped and added channels

An Experimental Platform for the Analysis of Polydisperse Systems Based on Light Scattering and Image Processing

In this work an experimental platform for light scattering analysis has been developed using image sensors, as CCD or CMOS. The main aim of this activity is the investigation of the feasibility of using these types of sensors for polydisperse systems analysis. The second purpose is the implementation of an experimental platform which is enough versatile to permit the observation of different phenomena in order to develop novel sensors/approach using data fusion

Frequency addressing of nano-objects by electrical tuning of optical antennas

We first analyze the equivalent circuit parameters of linear wire optical nano-antennas in uniaxial anisotropic media. We then exploit the electro-optic response of a bipolar nematic liquid crystal to demonstrate tuning of an optical antenna using a low frequency external electric field as the control mechanism

Anatomical basis of erector spinae plane block: a dissection and histotopographic pilot study

Purpose: Erector spinae plane (ESP) block is an interfascial blockade used in different clinical scenarios. This study investigated the ventral extent of dye diffusion in ESP block. Methods: The ultrasound-guided ESP block was bilaterally performed with an injection at the T5 vertebral level (21-Gauge, 50\ua0mm needle), using diluted black tissue marking dye (20\ua0mL; 1:4 ratio with standard saline solution) instead of local anesthetic on two fresh-frozen corpses within the body donation program of the University of Padova. Subsequently, the gross anatomical dissection was performed by a combined posterior plus anterior approach, and the histotopographic examination completed. Results: Macroscopically by gross anatomical dissection, the dye spreading ranged on the dorsal side of the chest from T2/3 to T10/11 with an extension up to 10\ua0cm laterally, and on the ventral side of the chest from T2/3\u2013T9/10. Microscopically by histotopographic examination, the dye diffused ventrally to the intercostal spaces (2\u20133 and 5\u20136 spaces on the right and left, respectively) by following the blood vessels coupled to the dorsal nerve passing through the costotransverse foramen. Conclusions: The anterior pathway of dye diffusion from the site of injection within the erector spinae muscle group during an ESP block seems to follow the blood vessels and dorsal rami of spinal nerves, suggesting the passing through the costotransverse foramen to reach the anterior paravertebral space and the intercostal nerves. These findings display an anterior histotopographic diffusion of dye resembling a paravertebral block