Non-Gaussian two-mode squeezing and continuous variable entanglement of linearly and circularly polarized light beams interacting with cold atoms

We investigate how entangled coherent states and superpositions of low intensity coherent states of non-Gaussian nature can be generated via non-resonant interaction between either two linearly or circularly polarized field modes and an ensemble of X-like four-level atoms placed in an optical cavity. We compare our results to recent experimental observations and argue that the non-Gaussian structure of the field states may be present in those systems.Comment: 10 pages, 7 figures, replaced with final published versio

New insight into hydration and aging mechanisms of paper by the line shape analysis of proton NMR spectra

The action of water within biological systems is strictly linked either with their physical chemical properties and with their functions. Cellulose is one of the most studied biopolymers due to its biological importance and its wide use in manufactured products. Among them, paper is mainly constituted by an almost equimolar ratio of cellulose and water. Therefore the study of the behavior of water within pristine and aged paper samples can help to shed light on the degradation mechanisms that irremediably act over time and spoil paper. In this work we present Nuclear Magnetic Resonance (NMR) experiments on modern paper samples made of pure cellulose not aged and artificially aged as well as on ancient paper samples made in 1413 in Perpignan (France). The line shape parameters of the proton NMR spectra were studied as a function of the hydration content. Results indicate that water in aged samples is progressively involved in the hydration of the byproducts of cellulose degradation. This enhances the degradation process itself through the progressive consumption of the cellulose amorphous regions

A weldability study of AL-CU-LI 2198 alloy

Al-Cu-Li alloys, conceived for automotive and aeronautic applications thanks to the high mechanical resistance/density ratio, exhibit weldability issues common to all light alloys. In this paper, the weldability of Al-Cu-Li 2198 alloy was studied by comparing features of welds carried out by two processes, the traditional arc welding and the friction stir welding (FSW). Welded joints were submitted to optical and SEM metallographic examinations with EDS microanalysis measurements. Mechanical characteristics were evaluated through microhardness tests and the instrumented indentation test FIMEC (Flat-top cylinder Indenter for MEchanical Characterization)

COMBINAZIONE DEI PROCESSI FASCIO LASER-ARCO ELETTRICO NELLA SALDATURA DI LAMIERE PLACCATE

Nel presente lavoro vengono riportati i risultati di prove di saldatura con utilizzo di un processo combinato arcoelettrico+ laser con tecnica a singola passata con l’utilizzo di un solo materiale di apporto. Tra le varie possibilità di accoppiamento arco elettrico-fascio laser, il procedimento qui descritto prevede la combinazione in serie dei due processi. Il materiale di prova è acciaio al carbonio placcato con acciaio inossidabile austenitico. Le prove sono state condotte con tecnica a passata unica e impiego di un solo materiale di apporto in forma di filo continuo. Sulla base dei risultati dei vari esami e prove (metallografia, microanalisi al SEM, prove di microdurezza e di trazione) è stata effettuata una valutazione della qualità dei giunti, con l’obiettivo di ricercare i parametri di saldatura adatti a realizzare una zona fusa esente da difetti e di composizione chimica accettabile

Laser beam welding of cast commercial pure titanium

In this work the joining by Laser Beam Welding (LBW) technique of commercial pure Titanium (CP Ti) cast specimens was carried out. The specimens considered for welding trials were cylindrical and flat (parallelepiped shape) ingots of little dimensions, as utilised in dentistry applications.The welds were investigated by optical and scanning electron microscopy (SEM) and by X-ray diffraction (XRD) measurements; mechanical properties were experimented by Vickers microhardness, across traverses through the welded sections, and by tensile tests, performed, for comparison, also on unwelded specimens in as cast condition; fractured surfaces after tensile tests were observed by SEM

Near-infrared spectroscopy as a tool for in vivo analysis of human muscles

Recent advances in materials and fabrication techniques provided portable, performant, sensing optical spectrometers readily operated by user-friendly cabled or wireless systems. Such systems allow rapid, non-invasive, and not destructive quantitative analysis of human tissues. This proof-of-principle investigation tested whether infrared spectroscopy techniques, currently utilized in a variety of areas, could be applied in living humans to categorize muscles. Using an ASD FieldSpec\uae 4 Standard-Res Spectroradiometer with a spectral sampling capability of 1.4 nm at 350\u20131000 nm and 1.1 nm at 1001\u20132500 nm, we acquired reflectance spectra in visible short-wave infra-red regions (350\u20132500 nm) from the upper limb muscles (flexors and extensors) of 20 healthy subjects (age 25\u201389 years, 9 women). Spectra off-line analysis included preliminary preprocessing, Principal Component Analysis, and Partial Least-Squares Discriminant Analysis. Near-infrared (NIR) spectroscopy proved valuable for noninvasive assessment of tissue optical properties in vivo. In addition to the non-invasive detection of tissue oxygenation, NIR spectroscopy provided the spectral signatures (ie, \u201cfingerprints\u201d) of upper limb flexors and extensors, which represent specific, accurate, and reproducible measures of the overall biological status of these muscles. Thus, non-invasive NIR spectroscopy enables more thorough evaluation of the muscular system and optimal monitoring of the effectiveness of therapeutic or rehabilitative interventions

Messa a punto di tecniche termografiche per il rilievo di difetti di fusione in getti di titanio commercialmente puro

Nel presente lavoro vengono riportati i risultati di uno studio sperimentale sull’applicazione di tecniche dimisura basate su termografia attiva per il rilievo di difettosità in provini di Ti commercialmente puro di grado2, realizzati mediante il metodo della fusione a cera persa. Le tecniche di termografia attiva ad infrarossimesse a punto hanno consentito di evidenziare la presenza di difetti sub-superficiali, non individuabiliattraverso i metodi convenzionali che utilizzano liquidi penetranti. In particolare sono state sperimentate siatecniche di termografia pulsata (“pulse phase”), basate sull’acquisizione delle mappe di temperaturasuperficiale dopo riscaldamento impulsivo dei provini, sia tecniche di termografia modulata (“lock-in”), basatesul rilievo delle mappe di temperatura durante l’applicazione di una sollecitazione termica sinusoidale. Laverifica dei risultati ottenuti con il metodo termografico è stata effettuata attraverso il confronto conosservazioni radiografiche a raggi ? e con indagini di tomografia rX computerizzata in 3D

Qualitative aspects of entanglement in the Jaynes-Cummings model with an external quantum field

We present a mathematical procedure which leads us to obtain analytical solutions for the atomic inversion and Wigner function in the framework of the Jaynes-Cummings model with an external quantum field, for any kinds of cavity and driving fields. Such solutions are expressed in the integral form, with their integrands having a commom term that describes the product of the Glauber-Sudarshan quasiprobability distribution functions for each field, and a kernel responsible for the entanglement. Considering two specific initial states of the tripartite system, the formalism is then applied to calculate the atomic inversion and Wigner function where, in particular, we show how the detuning and amplitude of the driving field modify the entanglement. In addition, we also obtain the correctComment: 15 pages and 21 figure

Effects of microalloying on an innovative quenched and tempered plastic mold steel

presentazione orale al TMS 2008 Annual Meeting & Exhibition (TMS2008), New Orleans, LA, USA, 9/3/2008 - 13/3/200

Effects of microalloying on an innovative quenched and tempered plastic mold steel

presentazione orale al TMS 2008 Annual Meeting & Exhibition (TMS2008), New Orleans, LA, USA, 9/3/2008 - 13/3/200