68 research outputs found
Simulazione di un geofono utilizzando pSPICE
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
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?
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
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
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
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
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
Three peaks and two dips have been detected in the power spectrum of the cosmic microwave background from the BOOMERANG experiment, at and , 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: {\it vs.} , {\it vs.} , and {\it vs.} . The deviation in primordial spectral index is a consequence of the strong correlation with the optical depth
First results from the BOOMERanG experiment
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 , with an amplitude of . 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 and (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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