40 research outputs found
The Sunyaev-Zeldovich MITO Project
Compton scattering of the cosmic microwave background radiation by electrons
in the hot gas in clusters of galaxies - the Sunyaev-Zeldovich effect - has
long been recognized as a uniquely important feature, rich in cosmological and
astrophysical information. We briefly describe the effect, and emphasize the
need for detailed S-Z and X-ray measurements of nearby clusters in order to use
the effect as a precise cosmological probe. This is the goal of the MITO
project, whose first stage consisted of observations of the S-Z effect in the
Coma cluster. We report the results of these observations.Comment: To appear in Proceedings of `Understanding our Universe at the close
of XXth century', School held Apr 25 - May 6 2000, Cargese, 16 pages LaTeX, 2
figures ps (using elsart.sty & elsart.cls), text minor revisio
Far infrared polarimeter with very low instrumental polarization
After a short analysis of the main problems involved in the construction of a
Far Infrared polarimeter with very low instrumental noise, we describe the
instrument that will be employed at MITO telescope to search for calibration
sources and investigate polarization near the CMB anisotropy peaks in the next
campaign (Winter 2002-03).Comment: 9 pages, 5 figures, to appear in SPIE conference proceedings
"Astronomical telescopes and instrumentation
MITO measurements of the Sunyaev-Zeldovich Effect in the Coma cluster of galaxies
We have measured the Sunyaev-Zeldovich effect towards the Coma cluster
(A1656) with the MITO experiment, a 2.6-m telescope equipped with a 4-channel
17 arcminute (FWHM) photometer. Measurements at frequency bands 143+/-15,
214+/-15, 272+/-16 and 353+/-13 GHz, were made during 120 drift scans of Coma.
We describe the observations and data analysis that involved extraction of the
S-Z signal by employing a spatial and spectral de-correlation scheme to remove
a dominant atmospheric component. The deduced values of the thermal S-Z effect
in the first three bands are DT_{0} = -179+/-38,-33+/-81,170+/-35 microKelvin
in the cluster center. The corresponding optical depth, tau=(4.1+/-0.9)
10^{-3}, is consistent (within errors) with both the value from a previous low
frequency S-Z measurement, and the value predicted from the X-ray deduced gas
parameters.Comment: Ap.J.Letters accepted, 4 pages, 2 figure
Improving assessment and management of pain in hemophilia. An Italian Delphi consensus statement
: Comprehensive evidence-based guidelines and well-validated assessment scales for pain in people with hemophilia (PwH) are needed. Here, we report 28 statements covering five topics on pain assessment and management in pediatric and adult PwH that were developed by 60 Italian hemophilia specialists during a Delphi consensus process. Overall, a clear consensus was achieved for 19 of the 28 statements. Consensus was reached on all statements on the topic of pain assessment and quality of life (QoL), including the need for regular pain assessment on a quantitative scale, the importance of distinguishing between different pain types, and the need to evaluate the impact of pain on patient QoL. The other four topics concerned acute and chronic pain management in adults and in children. Consensus was reached on statements regarding non-pharmacologic treatment and the use of first-line paracetamol (acetaminophen). There was a lack of consensus regarding the use of non-steroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors, or opioids
Cognitive and affective changes in mild to moderate Alzheimer's disease patients undergoing switch of cholinesterase inhibitors: a 6-month observational study.
Adherence issues related to sublingual immunotherapy as perceived by allergists
Objectives: Sublingual immunotherapy (SLIT) is a viable alternative to subcutaneous immunotherapy to treat allergic rhinitis and asthma, and is widely used in clinical practice in many European countries. The clinical efficacy of SLIT has been established in a number of clinical trials and meta-analyses. However, because SLIT is self-administered by patients without medical supervision, the degree of patient adherence with treatment is still a concern. The objective of this study was to evaluate the perception by allergists of issues related to SLIT adherence. Methods: We performed a questionnaire-based survey of 296 Italian allergists, based on the adherence issues known from previous studies. The perception of importance of each item was assessed by a VAS scale ranging from 0 to 10. Results: Patient perception of clinical efficacy was considered the most important factor (ranked 1 by 54% of allergists), followed by the possibility of reimbursement (ranked 1 by 34%), and by the absence of side effects (ranked 1 by 21%). Patient education, regular follow-up, and ease of use of SLIT were ranked first by less than 20% of allergists. Conclusion: These findings indicate that clinical efficacy, cost, and side effects are perceived as the major issues influencing patient adherence to SLIT, and that further improvement of adherence is likely to be achieved by improving the patient information provided by prescribers. © 2010 Scurati et al, publisher and licensee Dove Medical Press Ltd
Gas sensing properties of carbon nanostructures
This work is aimed to evaluate the optical gas sensing properties of carbon nanomaterial. In particular it is focused on two materials, Carbon Nanotubes (CNTs) and Graphene Oxide
(GO).
The comprehension of the mechanisms of interaction of these materials with the gas molecules is fundamental for a future application of these materials as sensors targeted to a
specific specie or capable to distinctly detect several dangerous species. On this purpose nanostructures based on GO and CNTs have been produced and tested as optical gas sensors toward oxidizing/reducing gases (H2, CO, NO2) and aromatic volatile Organic Compounds (benzene, toluene, xylene).
Gold nanoparticles (Au NPs) have been used as optical probe thanks to the peculiar Localized Surface Plasmon Resonance feature in the visible range, which is extremely
sensitive to the variation in optoelectronic properties of the surrounding media, such as refractive index and the variation in charge carrier involved in plasmonic excitation in the Au NPs.
Not only amplify the Au NPs the variation in optoelectronic properties of the layer of carbon nanomaterial, but also the electromagnetic coupling with carbon nanomaterials may induce
an enhancement in response and a lowering of the limit of detection of the sensors to the target species.
Moreover, the GO and CNTs are provided of a large possibility of functionalization, which can be used to tailor the gas sensing properties of the nanostructures toward specific species.
CNTs have been combined with the Au NPs, Pd NPs, Ni NPs and fullerenes. Pd and Au NPs increase the response toward H2
, meanwhile Ni NPs and fullerenes appear specific to CO. It
is also suggested the opportunity to monitor the features of the absorbance plot of fullerenes and CNT in the NIR as optical probes, with the carbon nanomaterials playing both the role
of sensing element and optical probe.
The presence of the different functional groups in GO was investigated. The increase in sp2conjugation has a profitable effect for the sensing of H2. Instead, the removal of the oxidized
functional groups hinder the response of the films toward CO and NO2.
The reduction and functionalization of the GO with para- Phenylene Diamine induces the detection of NH3without Au NPs as optical probe. The sensors produced are characterized by high transparency in the visible range and may be incorporated as non-invasive sensors on transparent surfaces.
Most of the sensors worked at 150°C and 300°C. Test of gas sensing have been conducted at low temperatures, at 80°C for CNTs in fullerene matrix and good results were achieved. The
possibility of sensors active at room temperature is suggested by the positive tests conducted with CMG, paving the way for future developments in active optical material sensitive to
gases at room temperature.Il presente lavoro è focalizzato sullo studio di sensori ottici basati su nanomateriali di carbonio, nell’ottica di un’applicazione di questi materiali come sensori di gas. Il lavoro prende in analisi due materiali, i nanotubi di carbonio (CNTs) e il grafene ossido (GO).
La comprensione dei meccanismi di interazione di questi materiali con le molecole di gas è fondamentale per le applicazioni future di questi materiali nel rilevamento di diverse specie nocive di gas. A tal proposito, nanostrutture a base di GO e CNTs sono state sviluppate e studiate come sensori ottici verso gas ossidanti-riducenti (H2, CO, NO2) e nei contronti di
composti volatili organici aromatici (benzene, toluene, xylene).
Le nanoparticelle di oro sono state utilizzate come sonde ottiche grazie alla loro peculiare caratterista di risonanza plasmonica di superficie localizzata, la quale è estremamente sensibile alle variazioni di proprietà ottico-elettroniche del mezzo che le circonda, come l’indice di rifrazione, e alle variazione di densità di portatori di carica che sono coinvolti nell'eccitazione plasmonica nelle nanoparticelle di oro.
Quindi, le nanoparticelle di oro, non solo amplificano le variazioni optoelettroniche del film di nanomateriali di carbonio a cui sono state accoppiate, ma interagiscono con questi
inducendo un miglioramento della risposta ai gas e un abbassamento del limite di rilevamento ai gas in analisi.
Inoltre, GO e CNTs presentano una vasta gamma di possibili funzionalizzazioni, che, possono essere sfruttate per una progettazione mirata delle proprietĂ di gas sensing delle nanostrutture di carbonio.
I CNTs sono stati abbinati a nanoparticelle di Au, Pd, Ni e a fullereni. Pd e Au portano ad un miglioramento delle prestazioni dei sensori verso il gas H2, nanoparticelle di Ni e fullereni
sembrano avere un’azione specifica verso il gas CO.
In questo lavoro viene anche suggerita la possiblitĂ di monitorare le proprietĂ di assorbanza di fullereni e CNTs nel range del vicino IR. I CNTs, in tal caso, avrebbero la duplice
funzione di sonde ottiche e di materiale sensibile.
Oltre all'effetto delle nanoparticelle di oro sulle proprietà di gas sensing del GO, è stata valutata l’influenza dei diversi gruppi funzionali. L’estensione dei domini sp2 sembra
favorire il rilevamento di H2, mentre una forte rimozione di gruppi funzionali inibisce la risposta del GO verso CO e NO
2
Gas sensing properties of carbon nanostructures
This work is aimed to evaluate the optical gas sensing properties of carbon nanomaterial. In particular it is focused on two materials, Carbon Nanotubes (CNTs) and Graphene Oxide
(GO).
The comprehension of the mechanisms of interaction of these materials with the gas molecules is fundamental for a future application of these materials as sensors targeted to a
specific specie or capable to distinctly detect several dangerous species. On this purpose nanostructures based on GO and CNTs have been produced and tested as optical gas sensors toward oxidizing/reducing gases (H2, CO, NO2) and aromatic volatile Organic Compounds (benzene, toluene, xylene).
Gold nanoparticles (Au NPs) have been used as optical probe thanks to the peculiar Localized Surface Plasmon Resonance feature in the visible range, which is extremely
sensitive to the variation in optoelectronic properties of the surrounding media, such as refractive index and the variation in charge carrier involved in plasmonic excitation in the Au NPs.
Not only amplify the Au NPs the variation in optoelectronic properties of the layer of carbon nanomaterial, but also the electromagnetic coupling with carbon nanomaterials may induce
an enhancement in response and a lowering of the limit of detection of the sensors to the target species.
Moreover, the GO and CNTs are provided of a large possibility of functionalization, which can be used to tailor the gas sensing properties of the nanostructures toward specific species.
CNTs have been combined with the Au NPs, Pd NPs, Ni NPs and fullerenes. Pd and Au NPs increase the response toward H2
, meanwhile Ni NPs and fullerenes appear specific to CO. It
is also suggested the opportunity to monitor the features of the absorbance plot of fullerenes and CNT in the NIR as optical probes, with the carbon nanomaterials playing both the role
of sensing element and optical probe.
The presence of the different functional groups in GO was investigated. The increase in sp2conjugation has a profitable effect for the sensing of H2. Instead, the removal of the oxidized
functional groups hinder the response of the films toward CO and NO2.
The reduction and functionalization of the GO with para- Phenylene Diamine induces the detection of NH3without Au NPs as optical probe. The sensors produced are characterized by high transparency in the visible range and may be incorporated as non-invasive sensors on transparent surfaces.
Most of the sensors worked at 150°C and 300°C. Test of gas sensing have been conducted at low temperatures, at 80°C for CNTs in fullerene matrix and good results were achieved. The
possibility of sensors active at room temperature is suggested by the positive tests conducted with CMG, paving the way for future developments in active optical material sensitive to
gases at room temperature.Il presente lavoro è focalizzato sullo studio di sensori ottici basati su nanomateriali di carbonio, nell’ottica di un’applicazione di questi materiali come sensori di gas. Il lavoro prende in analisi due materiali, i nanotubi di carbonio (CNTs) e il grafene ossido (GO).
La comprensione dei meccanismi di interazione di questi materiali con le molecole di gas è fondamentale per le applicazioni future di questi materiali nel rilevamento di diverse specie nocive di gas. A tal proposito, nanostrutture a base di GO e CNTs sono state sviluppate e studiate come sensori ottici verso gas ossidanti-riducenti (H2, CO, NO2) e nei contronti di
composti volatili organici aromatici (benzene, toluene, xylene).
Le nanoparticelle di oro sono state utilizzate come sonde ottiche grazie alla loro peculiare caratterista di risonanza plasmonica di superficie localizzata, la quale è estremamente sensibile alle variazioni di proprietà ottico-elettroniche del mezzo che le circonda, come l’indice di rifrazione, e alle variazione di densità di portatori di carica che sono coinvolti nell'eccitazione plasmonica nelle nanoparticelle di oro.
Quindi, le nanoparticelle di oro, non solo amplificano le variazioni optoelettroniche del film di nanomateriali di carbonio a cui sono state accoppiate, ma interagiscono con questi
inducendo un miglioramento della risposta ai gas e un abbassamento del limite di rilevamento ai gas in analisi.
Inoltre, GO e CNTs presentano una vasta gamma di possibili funzionalizzazioni, che, possono essere sfruttate per una progettazione mirata delle proprietĂ di gas sensing delle nanostrutture di carbonio.
I CNTs sono stati abbinati a nanoparticelle di Au, Pd, Ni e a fullereni. Pd e Au portano ad un miglioramento delle prestazioni dei sensori verso il gas H2, nanoparticelle di Ni e fullereni
sembrano avere un’azione specifica verso il gas CO.
In questo lavoro viene anche suggerita la possiblitĂ di monitorare le proprietĂ di assorbanza di fullereni e CNTs nel range del vicino IR. I CNTs, in tal caso, avrebbero la duplice
funzione di sonde ottiche e di materiale sensibile.
Oltre all'effetto delle nanoparticelle di oro sulle proprietà di gas sensing del GO, è stata valutata l’influenza dei diversi gruppi funzionali. L’estensione dei domini sp2 sembra
favorire il rilevamento di H2, mentre una forte rimozione di gruppi funzionali inibisce la risposta del GO verso CO e NO
2
Rivestimento Sol-Gel per la protezione di leghe di bronzo
Il lavoro tratta la protezione di manufatti di bronzo in ambiente atomosferico. Si è operato rivestendo dei campioni di bronzo, non trattati superficialmente, con un rivestimento sol-gel.In fase preliminare stato analizzato il materiale mediante metallografia e analisi XRF per conoscerne le propriet in modo dettagliato. E' seguita la caratterizzazione del rivestimeno mediante tecnica XRF, SEM, XPS, curve di polarizzazion