Hedgerows as form of agroforestry to sequester and store carbon in agricultural landscapes: a review

N/

ESTIMATING COMPARATIVE COSTS OF PRODUCING MILK AMONG THE SOUTHERN STATES

Production Economics,

The Projected Gross-Pitaevskii Equation for harmonically confined Bose gases

We extend the Projected Gross Pitaevskii equation formalism of Davis et al. [Phys. Rev. Lett. \bf{87}, 160402 (2001)] to the experimentally relevant case of harmonic potentials. We outline a robust and accurate numerical scheme that can efficiently simulate this system. We apply this method to investigate the equilibrium properties of a harmonically trapped three-dimensional Bose gas at finite temperature, and consider the dependence of condensate fraction, position and momentum distributions, and density fluctuations on temperature. We apply the scheme to simulate an evaporative cooling process in which the preferential removal of high energy particles leads to the growth of a Bose-Einstein condensate. We show that a condensate fraction can be inferred during the dynamics even in this non-equilibrium situation.Comment: 11 pages, 7 figure

Otolith chemistry, stomach contents and stable isotope analysis of a snapper (Pagrus auratus) caught in the Waikato River at Ngaruawahia

Analyses of stomach contents, stable isotopes and otolith microchemistry were carried out in order to ascertain the length of freshwater residence of a snapper (Pagrus auratus) caught in the Waikato River at Ngaruawahia in a net set for grey mullet(Mugil cephalus). Results of all analyses suggest that the snapper had spent all of its life in a marine environment with no evidence of freshwater residence in the otolith. Stable isotope analyses (δ15N = 17.0‰, δ13C = –17.1‰) indicated an entirely marine diet, and the stomach contents (two New Zealand screwshells, Maoricolpus roseus, and a hermit crab, Pagurus novizelandiae), suggested that the fish had not fed while in freshwater. However, this does not preclude the possibility that the snapper quickly travelled up the river, without eating, and was caught very soon after

Critical temperature of a trapped Bose gas: comparison of theory and experiment

We apply the Projected Gross-Pitaevskii equation (PGPE) formalism to the experimental problem of the shift in critical temperature $T_c$ of a harmonically confined Bose gas as reported in Gerbier \emph{et al.} [Phys. Rev. Lett. \textbf{92}, 030405 (2004)]. The PGPE method includes critical fluctuations and we find the results differ from various mean-field theories, and are in best agreement with experimental data. To unequivocally observe beyond mean-field effects, however, the experimental precision must either improve by an order of magnitude, or consider more strongly interacting systems. This is the first application of a classical field method to make quantitative comparison with experiment.Comment: revtex4, four pages, three figures. v2: updated to published version. Several additions to figures, and better explanations in text in response to referee comment

Assessing movement of rainbow trout and common smelt between Lake Rotoiti and Lake Rotorua using otolith chemical signatures: A summary of work so far

This study used otolith microchemistry to investigate movement of common smelt and rainbow trout between Lake Rotorua and Lake Rotoiti. Rainbow trout were collected from Lake Rotoiti, Lake Rotorua and the Ohau Channel, and smelt were collected from several locations in Lake Rotoiti and Lake Rotorua

Extraplanar Dust in the Edge-On Spiral NGC 891

We present high-resolution (<0.65") optical broad-band images of the edge-on Sb galaxy NGC 891 obtained with the WIYN 3.5-m telescope. These BVR images reveal a complex network of hundreds of dust absorbing structures far from the mid-plane of the galaxy. The dust structures have a wide range of morphologies and are clearly visible to |z|<1.5 kpc from the mid-plane. In this paper we discuss the general characteristics of the population of absorbing structures, as well as physical properties of 12 individual features. These 12 structures are characterised by N_H >10^21 cm^-2, with masses estimated to be more than 2x10^5 - 5x10^6 solar masses, assuming Galactic gas-to-dust relationships. The gravitational potential energies of the individual dust structures, given their observed heights and derived masses, lie in the range of 20-200x10^51 ergs. Rough number counts of extraplanar dust features suggest the mass of high-z gas associated with extraplanar dust in NGC 891 likely exceeds 2x10^8 solar masses, or ~2% of the total neutral ISM mass of the galaxy. We discuss several mechanisms which may produce high-z dust structures such as those seen in the images presented here. It is not yet known which of these mechanisms are primarily responsible for the extensive extraplanar dust structures seen in our images. The data presented are part of a larger program to search for and characterize off-plane dust structures in edge-on systems. (Abstract Abridged)Comment: To appear in the Astronomical Journal: 37 pages, Latex; 9 separate figures; the paper and high-resolution figures are also available at http://www.astro.wisc.edu/~howk/Papers/papers.htm