A method to correct differential nonlinearities in subranging analog-to-digital converters used for digital gamma-ray spectroscopy

The influence on $\gamma$-ray spectra of differential nonlinearities (DNL) in subranging, pipelined analog-to-digital converts (ADCs) used for digital $\gamma$-ray spectroscopy was investigated. The influence of the DNL error on the $\gamma$-ray spectra, depending on the input count-rate and the dynamic range has been investigated systematically. It turned out, that the DNL becomes more significant in $\gamma$-ray spectra with larger dynamic range of the spectroscopy system. An event-by-event offline correction algorithm was developed and tested extensively. This correction algorithm works especially well for high dynamic ranges

The 85$Rb(p,n)85Sr reaction and the modified proton optical potential

The cross sections of the astrophysically relevant 85$Rb(p,n)85Srg,m reaction have been measured between Ec.m. = 2.16 and 3.96 MeV. The cross sections have been derived by measuring the gamma radiation following the beta decay of the reaction products. A comparison with the predictions of Hauser-Feshbach calculations using the NON-SMOKER code confirms a recently derived modification of the global optical proton potential.Comment: CGS XIII conferenc

Grain Dynamics in a Two-dimensional Granular Flow

We have used particle tracking methods to study the dynamics of individual balls comprising a granular flow in a small-angle two-dimensional funnel. We statistically analyze many ball trajectories to examine the mechanisms of shock propagation. In particular, we study the creation of, and interactions between, shock waves. We also investigate the role of granular temperature and draw parallels to traffic flow dynamics.Comment: 17 pages, 24 figures. To appear in Phys.Rev.E. High res./color figures etc. on http://www.nbi.dk/CATS/Granular/GrainDyn.htm

Do divorcing couples become happier by breaking up?

Divorce is a leap in the dark. The paper investigates whether people who split up actually become happier. Using the British Household Panel Survey, we can observe an individual's level of psychological well-being in the years before and after divorce. Our results show that divorcing couples reap psychological gains from the dissolution of their marriages. Men and women benefit equally. The paper also studies the effects of bereavement, of having dependant children and of remarriage. We measure well-being by using general health questionnaire and life satisfaction scores

Origin and significance of clay‐coated fractures in mudrock fragments of the SAFOD borehole (Parkfield, California)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95148/1/grl21674.pd

Propagating front in an excited granular layer

A partial monolayer of ~ 20000 uniform spherical steel beads, vibrated vertically on a flat plate, shows remarkable ordering transitions and cooperative behavior just below 1g maximum acceleration. We study the stability of a quiescent disordered or ``amorphous'' state formed when the acceleration is switched off in the excited ``gaseous'' state. The transition from the amorphous state back to the gaseous state upon increasing the plate's acceleration is generally subcritical: An external perturbation applied to one bead initiates a propagating front that produces a rapid transition. We measure the front velocity as a function of the applied acceleration. This phenomenon is explained by a model based on a single vibrated particle with multiple attractors that is perturbed by collisions. A simulation shows that a sufficiently high rate of interparticle collisions can prevent trapping in the attractor corresponding to the nonmoving ground state.Comment: 16 pages, 9 figures, revised version, to appear in Phys. Rev. E, May 199

Studies of resonantly produced plasmas in the H-1NF heliac using a far-infrared scanning interferometer

The H-1NF heliac regularly operates using the ion cyclotron range of frequencies at 0.5 T to produce plasmas with a mixture of hydrogen and helium gases. Due to the complex three-dimensional structure of the magnetic fluxsurfaces, these plasmas require sophisticated diagnostic systems, with good spatial coverage, to extract meaningful physical information. This article presents a study of the dependence of the plasma density profile on resonant heating conditions and magnetic configuration, using a far-infrared scanning interferometer. Recent modifications to the system and data that illustrate the performance of the interferometer will be discussed

The bacterial pedome associated with foot pathologies in sheep::a case study

Hoof lameness is considered to be a major health issue in sheep, and can impact on both animal welfare and production of livestock. However the causes, although generally assumed to have a microbiological basis, are poorly understood. The work presented here investigated the pedome (the bacterial community of the foot) of sheep which were seen to have one of the following conditions: foot rot; a toe granuloma; Ovine Interdigital Dermatitis (OID) / scald. These were compared relative to samples collected from the healthy feet of the same animals. Samples were collected from commercial lambs from two flocks of sheep (one Beulahs, one Suffolks) at times of routine husbandry work. All animals in the flocks and those which showed signs of lameness (7 per flock) were used for sample collection. Interdigital scrapes were collected from lame feet, together with controls (i.e. non-lame feet) from the same animals. Of the lame feet, 3 were classified as having foot rot, 10 had OID / scald and 1 had a toe granuloma. DNA was isolated from the interdigital scrapes and analysed by next generation sequencing following amplification of DNA by PCR. All foot rot samples showed unusual microbial communities: one having an elevated abundance of Fusobacterium spp.; another with an elevated level of a Corynebacterium sp.; and the third an increased level of a number of unidentified sequences. One of the OID samples also had a high abundance of Fusobacterium spp., and another had a similar pattern of unknown organisms to that seen in the example of the foot rot case. The toe granuloma case showed an elevated level of a Mycoplasma sp. Therefore the organisms described here are different from those previously identified in a similar investigation into this topic. However the other eight OID samples had patterns similar to those in controls. This suggests microbial communities associated with ovine foot rot are complex, and that there are bacteria associated with the condition which remain unknown