Neutron Knockout Reactions

This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit

The Kent State "2π" Neutron Polarimeter

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Performance of a Neutron Polarimeter to Measure the Electric Form Factor of the Neutron

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

The 208-Pb(pol.p,pol.n)208-Bi Reaction at 135 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

NEUTRON DEEP-HOLE STATES FROM THE (p,pn) REACTION

Nous avons mesuré les spectres d'énergies de séparation et les sections efficaces pour les réactions 2H, 9Be, 16O, 28Si, 58Ni, et 90Zr (p,pn) à 150 MeV. On essaie d'identifier les énergies des états "trous profonds" de neutrons.We measured separation-energy spectra and cross sections for the reaction on 2H, 9Be, 16O, 28Si, 58Ni, and 90Zr at 150 MeV. Energies of neutron deep-hole states are tentatively identified

Polarization-transfer in (pol.p,pol.n) Reactions

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Are stock assessment methods too complicated? A critical review central on North Sea demersal stocks.

This critical review argues that several methods for the estimation and prediction of numbers-at-age, fishing mortality coefficients F, and recruitment for a stock of fish are too hard to explain to customers (the fishing industry, managers, etc.) and do not pay enough attention to weaknesses in the supporting data, assumptions and theory. The review is linked to North Sea demersal stocks. First, weaknesses in the various types of data used in North Sea assessments are summarized, i.e. total landings, discards, commercial and research vessel abundance indices, age-length keys and natural mortality (M). A list of features that an ideal assessment should have is put forward as a basis for comparing different methods. The importance of independence and weighting when combining different types of data in an assessment is stressed. Assessment methods considered are Virtual Population Analysis, ad hoc tuning, extended survivors analysis (XSA), year-class curves, catch-at-age modelling, and state-space models fitted by Kalman filter or Bayesian methods. Year-class curves (not to be confused with ‘catch-curves’) are the favoured method because of their applicability to data sets separately, their visual appeal, simple statistical basis, minimal assumptions, the availability of confidence limits, and the ease with which estimates can be combined from different data sets after separate analyses. They do not estimate absolute stock numbers or F but neither do other methods unless M is accurately known, as is seldom true