90 research outputs found
The effect of sample properties on the electron velocity in quantum Hall bars
We report on our theoretical investigation of the effects of the confining
potential profile and sample size on the electron velocity distribution in
(narrow) quantum-Hall systems. The electrostatic properties of the electron
system are obtained by the Thomas-Fermi-Poisson nonlinear screening theory. The
electron velocity distribution as a function of the lateral coordinate is
obtained from the slope of the screened potential at the Fermi level and within
the incompressible strips (ISs). We compare our findings with the recent
experiments.Comment: 8 pages, 6 figure
Investigation of the coupling asymmetries at double-slit interference experiments
Double-slit experiments inferring the phase and the amplitude of the
transmission coefficient performed at quantum dots (QD), in the Coulomb
blockade regime, present anomalies at the phase changes depending on the number
of electrons confined. This phase change cannot be explained if one neglects
the electron-electron interactions. Here, we present our numerical results,
which simulate the real sample geometry by solving the Poisson equation in 3D.
The screened potential profile is used to obtain energy eigenstates and
eigenvalues of the QD. We find that, certain energy levels are coupled to the
leads stronger compared to others. Our results give strong support to the
phenomenological models in the literature describing the charging of a QD and
the abrupt phase changes.Comment: conference paper, 50th anniversary of Aharonov-Bohm effec
An application of EMS98 in a medium-sized city: The case of L’Aquila (Central Italy) after the April 6, 2009 Mw 6.3 earthquake
This paper describes the damage survey in the city of L’Aquila after the 6 April
2009 earthquake. The earthquake, whose magnitude and intensity reached Mw=6.3 and
Imax=9–10 MCS, struck the Abruzzi region of Central Italy producing severe damage in
L’Aquila and in many villages along theMiddle Aterno River valley. After the event, a building-
to-building survey was performed in L’Aquila downtown aiming to collect data in order
to perform a strict evaluation of the damage. The survey was carried out under the European
Macroseismic Scale (EMS98) to evaluate the local macroseismic intensity. This damage survey
represents the most complex application of the EMS98 in Italy since it became effective.
More than 1,700 buildings (99% of the building stock) were taken into account during the
survey at L’Aquila downtown, highlighting the difficult application of the macroseismic scale
in a large urban context. The EMS98 revealed itself to be the best tool to perform such kind
of analysis in urban settings. The complete survey displayed evidence of peculiar features in
the damage distribution. Results revealed that the highest rate of collapses occurred within
a delimited area of the historical centre and along the SW border of the fluvial terrace on
which the city is settled. Intensity assessed for L’Aquila downtown was 8–9 EMS.Published67-801.11. TTC - Osservazioni e monitoraggio macrosismico del territorio nazionaleJCR Journalrestricte
Rilievo macrosismico del terremoto emiliano del 23 dicembre 2008
Questa nota presenta una sintesi delle attività svolte durante il rilievomacrosismico del terremoto avvenuto
tra le province di Parma e Reggio Emilia il 23 dicembre 2008. La scossa di Ml 5.2 è stata localizzata a sud
di Parma ed è stata avvertita in tutta l’Italia settentrionale e in gran parte della Liguria e della Toscana. Il
presente rapporto illustra lemodalità di intervento del teamQUEST, relative al rilievo degli effetti e alla valutazione
in intensità MCS in particolare per le località della zona epicentrale. L’ampia documentazione fotografica illustra
alcuni dettagli delle tipologie di danneggiamento rilevate e consente di comprendere meglio le valutazioni
dell’intensità macrosismica.
This paper presents an overview of the activities performed during the macroseismic field survey of the earthquake
that occurred in the Parma and Reggio Emilia region on December 23, 2008. The mainshock (Ml=5.2), was
located south of the city of Parma and was resolutely felt through Northern Italy. The report here presented shows
the procedures carried out by QUEST (Quick Earthquake Survey Team), concerning the survey. QUEST has been engaged
in gathering the damage information and in assessing the macroseismic intensity, in particular about the epicentral area.
A copious photo collection shows details of the observed damage nature and allows to better illustrate the intensit
An application of EMS98 in a medium-sized city: the case of l’Aquila (Central Italy) after the april 6, 2009 mw 6.3 earthquake
This paper describes the damage survey in the city of L’Aquila after the 6 April 2009
earthquake. The earthquake, whose magnitude and intensity reached Mw=6.3 and Imax=10 MCS,
struck the Abruzzi region of Central Italy producing severe damage in L’Aquila and in many
villages along the Middle Aterno River valley. After the event, a building-to-building survey was
performed in L’Aquila downtown aiming to collect data in order to perform a strict evaluation of
the damage. The survey was carried out under the European Macroseismic Scale (EMS98) to
evaluate the local macroseismic intensity. This damage survey represents the most complex
application of the EMS98 in Italy since it became effective. More than 1700 buildings (99% of the
building stock) were taken into account during the survey at L’Aquila downtown, highlighting the
difficult application of the macroseismic scale in a large urban context. The EMS98 revealed itself
to be the best tool to perform such kind of analysis in urban settings. The complete survey displayed
evidence of peculiar features in the damage distribution. Results revealed that the highest rate of
collapses occurred within a delimited area of the historical centre and along the SW border of the
fluvial terrace on which the city is settled. Intensity assessed for L’Aquila downtown was 8-9 EMS
An application of EMS98 in a medium-sized city: The case of L’Aquila (Central Italy) after the April 6, 2009 Mw 6.3 earthquake
This paper describes the damage survey in the city of L’Aquila after the 6 April
2009 earthquake. The earthquake, whose magnitude and intensity reached Mw=6.3 and
Imax=9–10 MCS, struck the Abruzzi region of Central Italy producing severe damage in
L’Aquila and in many villages along theMiddle Aterno River valley. After the event, a building-
to-building survey was performed in L’Aquila downtown aiming to collect data in order
to perform a strict evaluation of the damage. The survey was carried out under the European
Macroseismic Scale (EMS98) to evaluate the local macroseismic intensity. This damage survey
represents the most complex application of the EMS98 in Italy since it became effective.
More than 1,700 buildings (99% of the building stock) were taken into account during the
survey at L’Aquila downtown, highlighting the difficult application of the macroseismic scale
in a large urban context. The EMS98 revealed itself to be the best tool to perform such kind
of analysis in urban settings. The complete survey displayed evidence of peculiar features in
the damage distribution. Results revealed that the highest rate of collapses occurred within
a delimited area of the historical centre and along the SW border of the fluvial terrace on
which the city is settled. Intensity assessed for L’Aquila downtown was 8–9 EMS
L’indagine macrosismica: metodologia, parametri del terremoto, questioni aperte
Subito dopo l’evento del 6 aprile 2009, come di consueto è stata realizzata una lunga e complessa indagine macrosismica, promossa dal gruppo operativo QUEST, che ha avuto inizialmente l’obiettivo di delimitare l’area di danneggiamento, a supporto delle attività di pronto intervento della Protezione Civile, e successivamente quello di classificare nel modo più accurato e capillare possibile, gli effetti prodotti dall’evento, particolarmente nelle aree danneggiate.
A questo scopo è stata prodotta una stima utilizzando la scala MCS (Sieberg, 1930); in un secondo momento è stata rifinita l’indagine per una cinquantina di località dell’area maggiormente danneggiata (Is MCS>VII), raccogliendo ed elaborando i dati in termini di scala macrosismica EMS98 (Grünthal, 1998).
Per la complessità e la dimensione dei problemi affrontati, questo terremoto ha costituito un banco di prova di grande importanza per la macrosismologia italiana.
In questo testo viene descritto il lavoro realizzato, discutendo in particolare alcuni aspetti che hanno messo alla prova le metodologie di indagine tradizionali (sistematiche irregolarità degli insediamenti monitorati, forti divergenze degli scenari di danno rispetto a quelli previsti dalle scale, difficile comparabilità con scenari storici, ecc.) e presentandone i risultati, in relazione ai parametri epicentrali che ne risultano e il loro contributo più diretto alla comprensione complessiva della sismicità dell’area
The diagnostic suitability of a xerostomia questionnaire and the association between xerostomia, hyposalivation and medication use in a group of nursing home residents
The study objective was to explore the diagnostic suitability of the Xerostomia Inventory and the association between xerostomia, hyposalivation and medication use in a group of nursing home residents. A cross-sectional study was carried out in 50 physically impaired nursing home residents (20 men) with a mean age of 78.1 years (range, 53–98) in The Netherlands. The Xerostomia Inventory-Dutch version was completed for all residents and the data were subjected to exploratory factor analysis to determine the diagnostic suitability. Residents’ data on xerostomia, whole saliva secretion rates and hyposalivation-related medications used were collected and statistically analyzed. The diagnostic suitability of the Xerostomia Inventory-Dutch version appeared restricted. The prevalence of xerostomia was 52%, without gender and age difference. The prevalence of hyposalivation was 24% for resting, 60% for chewing-stimulated and 18% for acid-stimulated whole saliva. All whole saliva secretion rates were significantly lower in women than in men and in older than in younger residents. Forty-four percent of all medications used were hyposalivation-related and women used significantly more medications than men. Xerostomia was significantly negatively correlated with the resting whole saliva secretion rate. The number of hyposalivation-related medications used was not significantly correlated with the various whole saliva secretion rates. In nursing home residents, xerostomia, hyposalivation and using hyposalivation-related medications seem common and partially associated features
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