68 research outputs found

    Simulazione di un geofono utilizzando pSPICE

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    Questo lavoro studia il modello pSPICE (personal Simulation Program with Integrated Circuit Emphasis) di un geofono. Perché un modello pSPICE? La principale utilità di un modello (che va al di là dello studio asettico della funzione di trasferimento) è quello di interfacciarsi con il dispositivo elettronico che ne estende la risposta (è difficile oggi trovare un sismografo che non sia generosamente aiutato da un qualche misterioso dispositivo di feed-back). Mentre è relativamente facile indurre pSPICE a risolvere semplici problemi meccanici è molto più difficile indurre blasonati simulatori per sistemi meccanici ad incorporare un circuito elettronico. Il lavoro presentato parte da misure fatte su un geofono S-13 per costruirne il modello, che viene verificato con misure reali. Il modello viene usato per studiare il comportamento del geofono simulandone l’invecchiamento del magnete ed il comportamento ad alta frequenza (effetto dell’induttanza della bobina di pick-up). Viene mostrato come interfacciare il modello ad un semplice estensore di banda utilizzando il metodo di Lippmann, e vengono confrontate le risposte del geofono simulato prima e dopo l’espansione di banda. Infine viene simulata la risposta del modello a un terremoto reale, mostrando come operare sul resistore di smorzamento per evitare la saturazione per forti segnali. Questo lavoro può rappresentare il punto di partenza per chi voglia costruire, o soltanto capire, un sismometro a bilanciamento di forze

    Combined Carbon Dioxide Laser with Photodynamic Therapy for Nodular Basal Cell Carcinoma Monitored by Reflectance Confocal Microscopy

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    Introduction: Basal cell carcinoma (BCC) represents around 80% of all malignant skin cancers worldwide, constituting a substantial burden on healthcare systems. Due to excellent clearance rates (around 95%), surgery is the current gold-standard treatment. However, surgery is not always possible or preferred by patients. Numerous non-surgical therapies, sometimes combined, have been associated with promising tumor free survival rates (80-90%) in non-melanoma skin cancers (NMSCs). Most research has enrolled superficial basal cell carcinomas (sBCCs), with limited recent studies also involving low-risk nodular BCCs (nBCCs). Given lower efficacy rates compared to surgery, close monitoring during the follow-up period is essential for patients treated with non-surgical therapies. Monitoring with dermoscopy is constrained by low sensitivity rates. Reflectance confocal microscopy (RCM) is more sensitive in monitoring non-surgically treated NMSCs. Case presentation: A 41-year-old woman with a single nBCC relapse following photodynamic therapy (PDT) located on the dorsum of the nose presented to our center. Given the aesthetically sensitive location of the lesion and the patient's preference for a non-surgical approach, a combined treatment of CO2 laser and PDT was prescribed. A superpulsed CO2 laser (power: 0.5-3 W, frequency: 10 Hz, spot size 2 mm) with two PDT sessions (2 weeks apart) were conducted. At 6 weeks follow-up, monitoring performed with RCM revealed a reduction but not eradication of basaloid tumor islands. Another 2 sessions of PDT were recommended. At 3, 12 and 30 months of follow-up, the nasal dorsum area of the previous nBBC lesion was noted to be slightly hypopigmented (observed clinically), with a mild erythematous background (observed by dermoscopy). RCM evaluation confirmed the absence of RCM BCC criteria. The cosmetic outcome was very much improved. Conclusions: Combined CO2 laser and PDT for the treatment of a localized nBCC on the dorsum of the nose of a 41-year-old proved to offer tumor free survival at 30-month follow-up, as monitored with RCM. RCM is useful for the evaluation of non-surgical therapies as it has comparably higher sensitivity than dermoscopy and is especially useful in cases of suspected late recurrence. Further studies are needed to validate ongoing tumor free survival following this combined nonsurgical approach in the treatment of nBCC

    Che cosa ci faccio con l' s 13?

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    Sono illustrati i risultati ottenuti applicando il metodo di Lippmann (brevetto utilizzato da Lennartz Electronic) ad un sensore s13. E' mostrato un metodo per il confronto di sensori sismici utilizzante un filtro adattativ

    Noise Properties of the BOOMERANG Instrument

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    In this paper we report a short description of the BOOMERANG experiment explaining his scientific goal and the technologies implied. We concentrate then on the analysis of the noise properties discussing in particular the scan synchronous noise. Finally we present the calibration technique and the sensitivity of all the channels

    ℓ-space spectroscopy of the Cosmic Microwave Background with the BOOMERanG experiment

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    The BOOMERanG experiment has recently produced detailed maps of the Cosmic Microwave Background, where sub-horizon structures are resolved with good signal to noise ratio. A power spectrum (spherical harmonics) analysis of the maps detects three peaks, at multipoles ℓ = (213_(-13)^(+10)),(541_(-32)^(+20))(845_(-25)^(+12)). In this paper we discuss the data analysis and the implications of these results for cosmology

    B2K: The polarization-sensitive BOOMERanG experiment

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    We describe the new BOOMERanG payload, which is being prepared for a new circum-antarctic flight, with the aim to detect the linear polarization of the Cosmic Microwave Background (CMB). In addition to polarization capabilities, obtained by means of special bolometers, the instrument has been improved in the attitude reconstruction system and in the calibration system

    Near-infrared remote sensing of Los Angeles trace gas distributions from a mountaintop site

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    The Los Angeles basin is a significant anthropogenic source of major greenhouse gases (CO2 and CH4) and the pollutant CO, contributing significantly to regional and global climate change. We present a novel approach for monitoring the spatial and temporal distributions of greenhouse gases in the Los Angeles basin using a high-resolution spectroscopic remote sensing technique. A new Fourier transform spectrometer called CLARS-FTS has been deployed since May, 2010, at Jet Propulsion Laboratory (JPL)'s California Laboratory for Atmospheric Remote Sensing (CLARS) on Mt. Wilson, California, for automated long-term measurements of greenhouse gases. The instrument design and performance of CLARS-FTS are presented. From its mountaintop location at an altitude of 1673 m, the instrument points at a programmed sequence of ground target locations in the Los Angeles basin, recording spectra of reflected near-IR solar radiation. Column-averaged dry-air mole fractions of greenhouse gases (XGHG) including XCO2, XCH4, and XCO are retrieved several times per day for each target. Spectra from a local Spectralon® scattering plate are also recorded to determine background (free tropospheric) column abundances above the site. Comparisons between measurements from LA basin targets and the Spectralon® plate provide estimates of the boundary layer partial column abundances of the measured species. Algorithms are described for transforming the measured interferograms into spectra, and for deriving column abundances from the spectra along with estimates of the measurement precision and accuracy. The CLARS GHG measurements provide a means to infer relative, and possibly absolute, GHG emissions

    Multiple Peaks in the Angular Power Spectrum of the Cosmic Microwave Background: Significance and Consequences for Cosmology

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    Three peaks and two dips have been detected in the power spectrum of the cosmic microwave background from the BOOMERANG experiment, at 210,540,840\ell \sim 210, 540, 840 and 420,750\ell \sim 420, 750, respectively. Using model-independent analyses, we find that all five features are statistically significant and we measure their location and amplitude. These are consistent with the adiabatic inflationary model. We also calculate the mean and variance of the peak and dip locations and amplitudes in a large 7-dimensional parameter space of such models, which gives good agreement with the model-independent estimates, and forecast where the next few peaks and dips should be found if the basic paradigm is correct. We test the robustness of our results by comparing Bayesian marginalization techniques on this space with likelihood maximization techniques applied to a second 7-dimensional cosmological parameter space, using an independent computational pipeline, and find excellent agreement: Ωtot=1.020.05+0.06\Omega_{\rm tot} = 1.02^{+0.06}_{-0.05} {\it vs.} 1.04±0.051.04 \pm 0.05, Ωbh2=0.0220.003+0.004\Omega_b h^2 = 0.022^{+0.004}_{-0.003} {\it vs.} 0.0190.004+0.0050.019^{+0.005}_{-0.004}, and ns=0.960.09+0.10n_s = 0.96^{+0.10}_{-0.09} {\it vs.} 0.90±0.080.90 \pm 0.08. The deviation in primordial spectral index nsn_s is a consequence of the strong correlation with the optical depth

    First results from the BOOMERanG experiment

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    We report the first results from the BOOMERanG experiment, which mapped at 90, 150, 240 and 410 GHz a wide (3%) region of the microwave sky with minimal local contamination. From the data of the best 150 GHz detector we find evidence for a well defined peak in the power spectrum of temperature fluctuations of the Cosmic Microwave Background, localized at =197±6\ell = 197 \pm 6, with an amplitude of (68±8)μKCMB(68 \pm 8) \mu K_{CMB}. The location, width and amplitude of the peak is suggestive of acoustic oscillations in the primeval plasma. In the framework of inflationary adiabatic cosmological models the measured spectrum allows a Bayesian estimate of the curvature of the Universe and of other cosmological parameters. With reasonable priors we find Ω=(1.07±0.06)\Omega = (1.07 \pm 0.06) and ns=(1.00±0.08)n_s = (1.00 \pm 0.08) (68%C.L.) in excellent agreement with the expectations from the simplest inflationary theories. We also discuss the limits on the density of baryons, of cold dark matter and on the cosmological constant.Comment: Proc. of the CAPP2000 conference, Verbier, 17-28 July 200
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