Search results for "IPR"
showing 10 items of 1515 documents
Extremely cold antiprotons for antihydrogen production
1993
The possibility to produce, trap and study antihydrogen atoms rests upon the recent availability of extremely cold antiprotons in a Penning trap. Over the last five years, our TRAP Collaboration has slowed, cooled and stored antiprotons at energies 1010 lower than was previously possible. The storage time exceeds 3.4 months despite the extremely low energy, which corresponds to 4.2 K in temperature units. The first example of measurements which become possible with extremely cold antiprotons is a comparison of the antiproton inertial masses which shows they are the same to a fractional accuracy of 4×10−8. (This is 1000 times more accurate than previous comparisons and large additional incre…
A single trapped antiproton and antiprotons for antihydrogen production
1993
During the last several years, our TRAP collaboration has pioneered techniques for slowing, trapping, cooling and indefinitely storing antiprotons to energies more than 1010 times lower than previously possible. The radio signal from a single trapped antiproton is now being used for precision measurements. Many cold antiprotons are “stacked” as another important step toward the eventual production of antihydrogen, and positrons have been trapped in vacuum.
Using electric fields to prevent mirror-trapped antiprotons in antihydrogen studies
2013
The signature of trapped antihydrogen ($\overline{\mathrm{H}}$) atoms is the annihilation signal detected when the magnetic trap that confines the atoms is suddenly switched off. This signal would be difficult to distinguish from the annihilation signal of any trapped $\overline{p}$ that is released when the magnetic trap is switched off. This work deduces the large cyclotron energy ($g$137 eV) required for magnetic trapping of $\overline{p}$, considers the possibility that such $\overline{p}$ are produced, and explores the effectiveness of an electric field applied to clear charged particles from the trapping volume before $\overline{\mathrm{H}}$ detection. No mechanisms are found that can…
Pumped helium system for cooling positron and electron traps to 1.2 K
2011
Abstract Extremely precise tests of fundamental particle symmetries should be possible via laser spectroscopy of trapped antihydrogen ( H ¯ ) atoms. H ¯ atoms that can be trapped must have an energy in temperature units that is below 0.5 K—the energy depth of the deepest magnetic traps that can currently be constructed with high currents and superconducting technology. The number of atoms in a Boltzmann distribution with energies lower than this trap depth depends sharply upon the temperature of the thermal distribution. For example, ten times more atoms with energies low enough to be trapped are in a thermal distribution at a temperature of 1.2 K than for a temperature of 4.2 K. To date, H…
1985. El Consell Valencià de Cultura. Una ley sin votos en contra ni abstenciones.
2014
El Estatuto de Autonomía de la Comunidad Valenciana, en su artículo 25, recogía como institución de la Generalitat, la creación de un Consell de Cultura: "Una Llei de les Corts Valencianes establirà les funcions, la composició i l’organització del Consell de Cultura, els membres del qual seran elegits per majoria de dos terços de les Corts Valencianes". El proyecto se discutiría entre los grupos parlamentarios, para consensuar un texto duradero y común. Las Cortes Valencianas aprobaran la Llei del Consell Valencià de Cultura el 23 de octubre de 1985. El conseller de Cultura, Educación y Ciencia, Ciprià Císcar, en nombre del Govern Valencia, presentaría el proyecto: "entenent que per formar …
Effects of Trimipramine on Sleep EEG, Penile Tumescence and Nocturnal Hormonal Secretion
1989
Sleep EEG, nocturnal penile tumescence (NPT) and nocturnal endocrine activity were studied in 3 male control subjects during placebo, under trimipramine (TR) and after withdrawal. TR did not change the sleep structure. NPT activity tended to increase under TR. Nocturnal plasma cortisol levels decreased markedly while the early morning rise of cortisol appeared delayed under 200 mg TR. After withdrawal the changes of the cortisol secretion rebounded. Nocturnal secretion of GH, testosterone, LH and FSH remained unaffected, but plasma prolactin levels increased under TR and returned to normalcy after cessation. Our data illustrate that the neurobiological effects of TR are different from those…
Radio data and synchrotron emission in consistent cosmic ray models
2011
It is well established that phenomenological two-zone diffusion models of the galactic halo can very well reproduce cosmic-ray nuclear data and the observed antiproton flux. Here, we consider lepton propagation in such models and compute the expected galactic population of electrons, as well as the diffuse synchrotron emission that results from their interaction with galactic magnetic fields. We find models in agreement not only with cosmic ray data but also with radio surveys at essentially all frequencies. Requiring such a globally consistent description strongly disfavors very large ($L\gtrsim 15$ kpc) and, even stronger, small ($L\lesssim 1$ kpc) effective diffusive halo sizes. This has…
Exact Coulomb cutoff technique for supercell calculations in two dimensions
2009
We present a reciprocal space technique for the calculation of the Coulomb integral in two dimensions in systems with reduced periodicity, i.e., finite systems, or systems that are periodic only in one dimension. The technique consists in cutting off the long-range part of the interaction by modifying the expression for the Coulomb operator in reciprocal space. The physical result amounts in an effective screening of the spurious interactions originated by the presence of ghost periodic replicas of the system. This work extends a previous report [C. A. Rozzi et al., Phys. Rev. B 73, 205119 (2006)], where three-dimensional systems were considered. We show that the use of the cutoffs dramatic…
Autonomie e controlli della Corte dei conti nel quadro dei principi costituzionali e dei vincoli sovranazionali in materia economico-finanziaria
2022
Una riflessione dei controlli sulle autonomie territoriali intestati alla Corte dei conti non può prescindere dal loro inquadramento costituzionale. L’A. prospetta una ricostruzione del controllo come espressione di una funzione neutra e imparziale che deve riposare su precisi parametri costituzionali che ne legittimano l’adozione e di cui va resa una stretta interpretazione: il controllo sulle Autonomie territoriali deve così essere necessariamente una attività tale da avvicinarla a quella giurisdizionale piuttosto che amministrativa. È in tale chiave che deve essere inteso il rapporto fra ausiliarietà di cui all’art. 100 Cost. e controlli sui bilanci ed i rendiconti. L’evoluzione del quad…
Effects of SCA40 on human isolated bronchus and human polymorphonuclear leukocytes: comparison with rolipram, SKF94120 and levcromakalim
1996
1. SCA40 (0.1 nM-0.1 mM) produced concentration-dependent suppression of the spontaneous tone of human isolated bronchus (-log EC50 = 6.85 +/- 0.09; n = 10) and reached a maximal relaxation similar to that of theophylline (3 mM). The potency (-log EC50 values) of SCA40 compared to other relaxants was rolipram (7.44 +/- 0.12; n = 9) > SCA40 > or = levcromakalim (6.49 +/- 0.04; n = 6) > SKF94120 (5.87 +/- 0.10; n = 9). 2. When tested against the activity of the isoenzymes of cyclic nucleotide phosphodiesterase (PDE) isolated from human bronchus, SCA40 proved highly potent against PDE III (-log IC50 = 6.47 +/- 0.16; n = 4). It was markedly less potent against PDE IV (4.82 +/- 0.18; n = 4) and …