Search results for "Exchange"

Two particle-hole excitations in charged current quasielastic antineutrino-nucleus scattering

2013

We evaluate the quasielastic and multinucleon contributions to the antineutrino-nucleus scattering cross section and compare our results with the recent MiniBooNE data. We use a local Fermi gas model that includes RPA correlations and gets the multinucleon part from a systematic many body expansion of the W boson selfenergy in the nuclear medium. The same model had been quite successful for the neutrino cross section and contains no new parameters. We have also analyzed the relevance of 2p2h events for the antineutrino energy reconstruction.

Solidification of ion exchange resins saturated with Na+ ions: Comparison of matrices based on Portland and blast furnace slag cement

2017

International audience; Ion exchange resins (IERs) are widely used by the nuclear industry to decontaminate radioactive effluents. After use, they are usually stabilized and solidified by encapsulation in cementitious materials. However, for certain combinations of cement and resins, the solidified waste forms can exhibit strong expansion, possibly leading to cracking of the matrix. In this work, the behaviour of cationic resins in the Na$^+$ form is investigated in Portland cement (CEM I) or blast furnace slag cement (CEM III/C) pastes at early age in order to have a better understanding of the swelling process. The results show that during the hydration of the CEM I paste, the resins exhi…

Energy loss and straggling of MeV Si ions in gases

2017

We present measurements of energy loss and straggling of Si ions in gases. An energy range from 0.5 to 12 MeV/u was covered using the 6 MV EN tandem accelerator at ETH Zurich, Switzerland, and the K130 cyclotron accelerator facility at the University of Jyväskylä, Finland. Our energy-loss data compare well with calculation based on the SRIM and PASS code. The new straggling measurements support a pronounced peak in He gas at around 4 MeV/u predicted by recent theoretical calculations. The straggling curve structure in the other gases (N2, Ne, Ar, Kr) is relatively flat in the covered energy range. Although there is a general agreement between the straggling data and the theoretical calculat…

Temperature dependence of the dynamics of ultrafine particles in a polymeric network

1990

Simple model systems with pronounced dynamical features will help to get a deeper insight into the complicated dynamics of large molecular networks. We investigated the bounded diffusion of ultrafine Fe(OH)3 particles (∼30 A in diameter) in the three-dimensional network of the cation exchanger Dowex 50 W which was solvated with a water solution of sucrose (60 wt%). Mossbauer spectra were recorded in the temperature range from 80 K to 305 K. At temperatures above 250 K broad diffusional lines of different widths appear in the spectrum proving the bounded nature of the diffusion. The line widths strongly increase with temperature to values of several hundred mm/s. Around 300 K a large portion…

Beam-normal single spin asymmetry in elastic electron scattering off 28Si and 90Zr

2020

We report on a new measurement of the beam-normal single spin asymmetry $A_{\mathrm{n}}$ in the elastic scattering of 570 MeV transversely polarized electrons off $^{28}$Si and $^{90}$Zr at $Q^{2}=0.04\, \mathrm{GeV}^2/c^2$. The studied kinematics allow for a comprehensive comparison with former results on $^{12}$C. No significant mass dependence of the beam-normal single spin asymmetry is observed in the mass regime from $^{12}$C to $^{90}$Zr.

Meson and isobar degrees of freedom in light nuclei

1983

The role of mesonic and isobar degrees of freedom in various electromagnetic processes is reviewed for light nuclei. Special emphasis is laid on the deuteron, which allows the cleanest answers within the non-relativistic framework. The origin of the photonuclear enhancement with respect to both exchange forces and exchange currents is discussed in detail.

Neutrino-nuclear responses for astro-neutrinos, single beta decays and double beta decays

2019

Abstract Neutrino–nuclear responses associated with astro-neutrinos, single beta decays and double beta decays are crucial in studies of neutrino properties of interest for astro-particle physics. The present report reviews briefly recent studies of the neutrino–nuclear responses from both experimental and theoretical points of view in order to obtain a consistent understanding of the many facets of the neutrino–nuclear responses. Subjects discussed in this review include (i) experimental studies of neutrino–nuclear responses by means of single beta decays, charge-exchange nuclear reactions, muon- photon- and neutrino–nuclear reactions, and nucleon-transfer reactions, (ii) implications of a…

Soil-Water Interactions Unveiled by Fast Field Cycling NMR Relaxometry

2017

Growth and physiological responses of young olive trees affected by Olive leaf yellowing associated virus

2017

We studied the effect of Olive leaf yellowing associated virus (OLYaV) on biometric and physiological changes in olive. The trial was carried out on 32 two-yearold virus-free trees of 'Frantoio' grafted on virus-free olive seedlings and grown in 32-L pots. Half of the trees were inoculated with OLYaV in the fall of 2007. At 6, 18, and 24 months after inoculation, tree height, basal trunk diameter and total leaf number were determined, and leaf area tree-1 was estimated from a 50-leaf subsample. Twigs of various order were also counted and measured. At the end of the experiment, dry matter partitioning, leaf gas exchange and water potential were also measured. Total twig length and number, t…

Why FX Risk Management Is Broken - And What Boards Need to Know to Fix It

2015

In this paper we rethink the role of Foreign Exchange Risk Management (FXRM) in corporate management. We believe it is fair to characterize FXRM, on the whole, as a legacy activity rather than something that reflects a realistic cost-benefit analysis at the enterprise-level. The Board of Directors, as the designated guardians of the interests of shareholders, has a key role in setting the firm on a path towards a cost-efficient and centralized FXRM that preserves the firm’s transparency and predictability towards the investor community. A policy conclusion from our analysis is that responsibility for FX policy should shift from the traditional Finance/Treasury orientation to a group risk fu…