Search results for "PEI"
showing 10 items of 367 documents
Gamma-induced background in the KATRIN main spectrometer
2019
The KATRIN experiment aims to measure the effective electron antineutrino mass $$m_{\overline{\nu }_e}$$ mν¯e with a sensitivity of $${0.2}\,{\hbox {eV}/\hbox {c}^2}$$ 0.2eV/c2 using a gaseous tritium source combined with the MAC-E filter technique. A low background rate is crucial to achieving the proposed sensitivity, and dedicated measurements have been performed to study possible sources of background electrons. In this work, we test the hypothesis that gamma radiation from external radioactive sources significantly increases the rate of background events created in the main spectrometer (MS) and observed in the focal-plane detector. Using detailed simulations of the gamma flux in the e…
In memory of the celebration of the 50th Jubilee of the Riga Natural Sciences Association
1895
Speise - Karte zur Erinnerung an die Feier des 50jr. Jubiläums des Naturforscher-Verein zu Riga mit mit Elementen der Paläontologie und Cartoons. Rīgas Dabaspētnieku biedrības 50 gadu jubilejas piemiņas ēdienkarte ar paleontoloģijas elementiem un karikatūrām. (BOT15515)
Altiero Spinelli e Alcide De Gasperi: due opposte fedi e una stessa idea d'Europa.
2008
Un parallelismo tra Altiero Spinelli e Alciide De Gasperi, due uomini politici di confessione religiosa e di afferenza partitica diverse, ma saldamente uniti dal comune ideale europeista, per la realizzazione del quale collaborarono da veri federalisti.
Measure differential inclusions: existence results and minimum problems
2020
AbstractWe focus on a very general problem in the theory of dynamic systems, namely that of studying measure differential inclusions with varying measures. The multifunction on the right hand side has compact non-necessarily convex values in a real Euclidean space and satisfies bounded variation hypotheses with respect to the Pompeiu excess (and not to the Hausdorff-Pompeiu distance, as usually in literature). This is possible due to the use of interesting selection principles for excess bounded variation set-valued mappings. Conditions for the minimization of a generic functional with respect to a family of measures generated by equiregulated left-continuous, nondecreasing functions and to…
La lingua nell'apprendimento della Matematica da parte dei ragazzi cinesi. Una ricerca di didattica della Matematica
2011
Il presente contributo discute alcune delle problematiche affrontate dal G.R.I.M. di Palermo sull'insegnamento/apprendimento delle matematiche in situazione di multiculturalità ed in particolare affronta lo studio della disciplina attraverso considerazioni di carattere sociale, culturale, antropologico, geografico etc. Si focalizza l’attenzione sulle relazioni (analizzate anche attraverso un continuo riferimento alla storia della Matematica), tra lingua naturale e forme argomentative rilevanti per l’apprendimento della disciplina nella cultura orientale (cinese) ed occidentale (europea). Vengono presentati i risultati di ricerca ottenuti dalla fine degli anni ’90 sino alla pubblicazione del…
Echi pompeiani ed ercolanesi nella scenografia teatrale del XIX secolo
2010
Tra le opere liriche messe in scena nel primo Ottocento, alcune erano ambientate nell’antichità greco-romana. Per la creazione di scenari che apparissero plausibili gli scenografi talora riproducevano monumenti reali, come quelli di Pompei ed Ercolano.
Highly sensitive superconducting circuits at ∼700 kHz with tunable quality factors for image-current detection of single trapped antiprotons
2016
We developed highly-sensitive image-current detection systems based on superconducting toroidal coils and ultra-low noise amplifiers for non-destructive measurements of the axial frequencies (550$\sim$800$\,$kHz) of single antiprotons stored in a cryogenic multi-Penning-trap system. The unloaded superconducting tuned circuits show quality factors of up to 500$\,$000, which corresponds to a factor of 10 improvement compared to our previously used solenoidal designs. Connected to ultra-low noise amplifiers and the trap system, signal-to-noise-ratios of 30$\,$dB at quality factors of > 20$\,$000 are achieved. In addition, we have developed a superconducting switch which allows continuous tu…
Sympathetic cooling of protons and antiprotons with a common endcap Penning trap.
2017
We present an experiment to sympathetically cool protons and antiprotons in a Penning trap by resonantly coupling the particles to laser cooled beryllium ions using a common endcap technique. Our analysis shows that preparation of (anti)protons at mK temperatures on timescales of tens of seconds is feasible. Successful implementation of the technique will have immediate and significant impact on high-precision comparisons of the fundamental properties of protons and antiprotons. This in turn will provide some of the most stringent tests of the fundamental symmetries of the Standard Model.
Oleuropein protects against dextran sodium sulfate-induced chronic colitis in mice.
2013
The anti-inflammatory effect of oleuropein (1), the major phenolic secoiridoid in Olea europaea, was evaluated in an experimental model of chronic colitis in mice. Animals were exposed to four repeated cycles of dextran sodium sulfate in drinking water followed by a 7-day rest period. Animals receiving a standard diet supplemented with 0.25% of 1 (equivalent to 500 mg/kg/day) for 56 days exhibited a decrease of inflammatory symptoms, as reflected by improvement of disease activity index and histopathological changes. It was found that 1 decreased inflammatory cell recruitment and the release of inflammatory cytokines interleukin (IL)-1β and IL-6 with increased IL-10 levels in colon tissue. …
Study of the Ti-44(alpha, p)V-47 reaction and implications for core collapse supernovae
2014
The underlying physics triggering core collapse supernovae is not fully understood but observations of material ejected during such events helps to solve this puzzle. In particular, several satellite based γ -ray observations of the isotope 44Ti have been reported recently. Conveniently, the amount of this isotope in stellar ejecta is thought to depend critically on the explosion mechanism. The most influential reaction to the amount of 44Ti in supernovae is 44Ti(α, p)47V. Here we report on a direct study of this reaction conducted at the REX-ISOLDE facility, CERN. The experiment was performed with a 44Ti beam at Elab = 2.16 MeV/u, corresponding to an energy distribution, for reacting α-par…