618 research outputs found
Rapid continuous chemical analysis of meat chicken shed emissions by SIFT–MS
Assessing and addressing odour impacts from poultry production is extremely difficult and subjective because the odorants involved and their dynamics over time and space are poorly understood. This knowledge gap is due, in part, to the lack of suitable analytical tools for measuring and monitoring odorants in the field. The emergence of Selected Ion Flow Tube – Mass Spectrometry (SIFT–MS) and similar instruments is changing that. These tools can rapidly quantify targeted odorants in ambient air in real time, even at very low concentrations. Such data is essential for developing better odour abatement strategies, assessment methods and odour dispersion models.
This project trialled a SIFT–MS to determine its suitability for assessing the odorants in meat chicken shed emissions over time and space. This report details evaluations in New Zealand and Australia to determine the potential of SIFT–MS as a tool for the chicken meat industry, including odour measurement (as a proxy for dynamic olfactometry).
The report is specifically targeted at those funding and conducting poultry odour research. It will be of interest to those involved with environmental odour monitoring and assessment in general. The high upfront cost of SIFT–MS will lead to potential users wanting compelling evidence that SIFT–MS will meet their needs before they invest in one
Artificial olfaction system for on-site odour measurement
Odour impacts and concerns are an impediment to the growth of the Australian chicken meat industry. To manage these, the industry has to be able to demonstrate the efficacy of its odour reduction strategies scientifically and defensibly; however, it currently lacks reliable, cost effective and objective tools to do so. This report describes the development of an artificial olfaction system (AOS) to measure meat chicken farm odour. This report describes the market research undertaken to determine the demand for such a tool, the development and evaluation of three AOS prototypes, data analysis and odour prediction modelling, and the development of two complementary odour measurement tools, namely, a volatile organic compound (VOC) pre-concentrator and a field olfactometer.
This report is aimed at investors in poultry odour research and those charged with, or interested in, assessment of odour on chicken farms, including farm managers, integrators, their consultants, regulators and researchers. The findings will influence the focus of future environmental odour measurement research
Gladstone Harbour Fish Health Investigation 2011-2012
The Gladstone Harbour Fish Health Investigation occurred in response to public concerns regarding fish health in Gladstone Harbour, which were raised with the former Department of Employment, Economic Development and Innovation (now Department of Agriculture, Fisheries and Forestry (DAFF)) in August 2011. The majority of concerns were regarding skin redness, lesions and eye damage observed on barramundi caught from the Boyne River or within its vicinity. Further reports included unusual skin redness and occasional lesions observed on a range of fish species from Gladstone Harbour (including sharks), as well as an increase in the incidence of shell erosion on mud crabs. The subsequent investigation aimed to determine the cause of the reported issues and specifically to address public concern regarding the potential impact of industrial activity including dredging in Gladstone Harbour. The investigation, conducted by DAFF, was part of a whole-of-government response, which included sediment and water quality testing; and investigation into human health concerns.
The first reports of abnormalities in fish were received months after a major flood event happened in Gladstone from December 2010 until early 2011. The flood event caused a dramatic influx of large barramundi (estimated 30 000), as well as other species from Lake Awoonga into the Boyne River when the Awoonga Dam spilled over. The dam had not spilled over since the 1990s, well before the dam wall was raised in 2002. Many of these fish were injured (some fatally) from the force of the impact when passing over the spillway. It is believed that a smaller number of fish were washed over during a second flood event in early 2012.
The initial response investigated fish with visible abnormalities (e.g. missing scales and redness), and signs of disease to indicate the cause of the observed issues. This early sampling (Phase 1) between August 2011 and February 2012 was based on observations of commercial fishing activity, contracted fish surveys and submissions by members of the public. Over 5000 fish, crustaceans and molluscs were visually assessed during this sampling.
In January 2012, the Independent Gladstone Fish Health Scientific Advisory Panel released a report recommending a structured sampling program to gauge fish health in Gladstone Harbour sites against comparable unaffected sites (reference sites), through time. It also recommended the development of a conceptual model of possible cause-effect relationships to help guide studies and eliminate potential causal factors.
Structured sampling in Gladstone Harbour (Phase 2) was conducted in two major surveys during April–May (Trip 1) and June–July (Trip 2) 2012. These surveys covered 11 sites including two reference sites and focussed on a subset of 10 species. The selected species represented a range of different life cycles (e.g. catadromous and estuarine) and trophic levels (e.g. predatory, omnivorous detritivores and scavengers), and had been reported with a variety of abnormalities. A third targeted survey was conducted in September 2012 to monitor potential seasonal reoccurrence of parasitic infestations in the barramundi from the Boyne River. A total of 3699 fish and crustaceans were visually assessed in the field, with 452 specimens examined by necropsy, and tissues from 120 specimens subjected to histopathology and chemical residue testing
Sneutrino cold dark matter, a new analysis: relic abundance and detection rates
We perform a new and updated analysis of sneutrinos as dark matter
candidates, in different classes of supersymmetric models. We extend previous
analyses by studying sneutrino phenomenology for full variations of the
supersymmetric parameters which define the various models. We first revisit the
standard Minimal Supersymmetric Standard Model, concluding that sneutrinos are
marginally compatible with existing experimental bounds, including direct
detection, provided they compose a subdominant component of dark matter. We
then study supersymmetric models with the inclusion of right-handed fields and
lepton-number violating terms. Simple versions of the lepton-number-violating
models do not lead to phenomenology different from the standard case when the
neutrino mass bounds are properly included. On the contrary, models with
right-handed fields are perfectly viable: they predict sneutrinos which are
compatible with the current direct detection sensitivities, both as subdominant
and dominant dark matter components. We also study the indirect detection
signals for such successful models: predictions for antiproton, antideuteron
and gamma-ray fluxes are provided and compared with existing and future
experimental sensitivities. The neutrino flux from the center of the Earth is
also analyzed.Comment: 72 pages, 50 figures. The version on the archive has low-resolution
figures. The paper with high resolution figures may be found through
http://www.to.infn.it/~arina/papers or
http://www.to.infn.it/~fornengo/Research/paperlist.htm
High speed synchrotron X-ray imaging studies of the ultrasound shockwave and enhanced flow during metal solidification processes
The highly dynamic behaviour of ultrasonic bubble implosion in liquid metal, the multiphase liquid metal flow containing bubbles and particles, and the interaction between ultrasonic waves and semisolid phases during solidification of metal were studied in situ using the complementary ultrafast and high speed synchrotron X-ray imaging facilities housed respectively at the Advanced Photon Source, Argonne National Laboratory, US, and Diamond Light Source, UK. Real-time ultrafast X-ray imaging of 135,780 frames per second (fps) revealed that ultrasonic bubble implosion in a liquid Bi-8 wt. %Zn alloy can occur in a single wave period (30 kHz), and the effective region affected by the shockwave at implosion was 3.5 times the original bubble diameter. Furthermore, ultrasound bubbles in liquid metal move faster than the primary particles, and the velocity of bubbles is 70 ~ 100% higher than that of the primary particles present in the same locations close to the sonotrode. Ultrasound waves can very effectively create a strong swirling flow in a semisolid melt in less than one second. The energetic flow can detach solid particles from the liquid-solid interface and redistribute them back into the bulk liquid very effectively
Dark matter and Colliders searches in the MSSM
We study the complementarity between dark matter experiments (direct
detection and indirect detections) and accelerator facilities (the CERN LHC and
a TeV Linear Collider) in the framework of the
constrained Minimal Supersymmetric Standard Model (MSSM). We show how
non--universality in the scalar and gaugino sectors can affect the experimental
prospects to discover the supersymmetric particles. The future experiments will
cover a large part of the parameter space of the MSSM favored by WMAP
constraint on the relic density, but there still exist some regions beyond
reach for some extreme (fine tuned) values of the supersymmetric parameters.
Whereas the Focus Point region characterized by heavy scalars will be easily
probed by experiments searching for dark matter, the regions with heavy
gauginos and light sfermions will be accessible more easily by collider
experiments. More informations on both supersymmetry and astrophysics
parameters can be thus obtained by correlating the different signals.Comment: 25 pages, 10 figures, corrected typos and reference adde
Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab
We present measurements of the differential cross section and Lambda recoil
polarization for the gamma p to K+ Lambda reaction made using the CLAS detector
at Jefferson Lab. These measurements cover the center-of-mass energy range from
1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles.
Independent analyses were performed using the K+ p pi- and K+ p (missing pi -)
final-state topologies; results from these analyses were found to exhibit good
agreement. These differential cross section measurements show excellent
agreement with previous CLAS and LEPS results and offer increased precision and
a 300 MeV increase in energy coverage. The recoil polarization data agree well
with previous results and offer a large increase in precision and a 500 MeV
extension in energy range. The increased center-of-mass energy range that these
data represent will allow for independent study of non-resonant K+ Lambda
photoproduction mechanisms at all production angles.Comment: 22 pages, 16 figure
Tensor Correlations Measured in 3He(e,e'pp)n
We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV
over a wide kinematic range. We identified spectator correlated pp and pn
nucleon pairs using kinematic cuts and measured their relative and total
momentum distributions. This is the first measurement of the ratio of pp to pn
pairs as a function of pair total momentum, . For pair relative
momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low and
rises to approximately 0.5 at large . This shows the dominance of
tensor over central correlations at this relative momentum.Comment: 4 pages, 4 figures, submitted to PR
Measurement of the nuclear multiplicity ratio for hadronization at CLAS
The influence of cold nuclear matter on lepto-production of hadrons in
semi-inclusive deep inelastic scattering is measured using the CLAS detector in
Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the
multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a
function of the fractional virtual photon energy transferred to the
and the transverse momentum squared of the . We find that the
multiplicity ratios for are reduced in the nuclear medium at high
and low , with a trend for the transverse momentum to be
broadened in the nucleus for large .Comment: Submitted to Phys. Lett.
Random Convex Hulls and Extreme Value Statistics
In this paper we study the statistical properties of convex hulls of
random points in a plane chosen according to a given distribution. The points
may be chosen independently or they may be correlated. After a non-exhaustive
survey of the somewhat sporadic literature and diverse methods used in the
random convex hull problem, we present a unifying approach, based on the notion
of support function of a closed curve and the associated Cauchy's formulae,
that allows us to compute exactly the mean perimeter and the mean area enclosed
by the convex polygon both in case of independent as well as correlated points.
Our method demonstrates a beautiful link between the random convex hull problem
and the subject of extreme value statistics. As an example of correlated
points, we study here in detail the case when the points represent the vertices
of independent random walks. In the continuum time limit this reduces to
independent planar Brownian trajectories for which we compute exactly, for
all , the mean perimeter and the mean area of their global convex hull. Our
results have relevant applications in ecology in estimating the home range of a
herd of animals. Some of these results were announced recently in a short
communication [Phys. Rev. Lett. {\bf 103}, 140602 (2009)].Comment: 61 pages (pedagogical review); invited contribution to the special
issue of J. Stat. Phys. celebrating the 50 years of Yeshiba/Rutgers meeting
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