3,782 research outputs found
Photometric Variability in Earthshine Observations
The identification of an extrasolar planet as Earth-like will depend on the
detection of atmospheric signatures or surface non-uniformities. In this paper
we present spatially unresolved flux light curves of Earth for the purpose of
studying a prototype extrasolar terrestrial planet. Our monitoring of the
photometric variability of earthshine revealed changes of up to 23 % per hour
in the brightness of Earth's scattered light at around 600 nm, due to the
removal of specular reflection from the view of the Moon. This variability is
accompanied by reddening of the spectrum, and results from a change in surface
properties across the continental boundary between the Indian Ocean and
Africa's east coast. Our results based on earthshine monitoring indicate that
specular reflection should provide a useful tool in determining the presence of
liquid water on extrasolar planets via photometric observations.Comment: To appear in Astrobiology 9(3). 17 pages, 3 figures, 1 tabl
Extensions for the activated sludge modelling framework for xenobiotic organic micro-pollutants (ASM-X) - sorption, sequestration and co-metabolism of diclofenac and carbamazepine
Structure of MnO nanoparticles embedded into channel-type matrices
X-ray diffraction experiments were performed on MnO confined in mesoporous
silica SBA-15 and MCM-41 matrices with different channel diameters. The
measured patterns were analyzed by profile analysis and compared to numerical
simulations of the diffraction from confined nanoparticles. From the lineshape
and the specific shift of the diffraction reflections it was shown that the
embedded objects form ribbon-like structures in the SBA-15 matrices with
channels diameters of 47-87 {\AA}, and nanowire-like structures in the MCM-41
matrices with channels diameters of 24-35 {\AA}. In the latter case the
confined nanoparticles appear to be narrower than the channel diameters. The
physical reasons for the two different shapes of the confined nanoparticles are
discussed.Comment: 8 pages, including 9 postscript figures, uses revtex4.cl
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
Quantum process tomography of a controlled-NOT gate
We demonstrate complete characterization of a two-qubit entangling process -
a linear optics controlled-NOT gate operating with coincident detection - by
quantum process tomography. We use maximum-likelihood estimation to convert the
experimental data into a physical process matrix. The process matrix allows
accurate prediction of the operation of the gate for arbitrary input states,
and calculation of gate performance measures such as the average gate fidelity,
average purity and entangling capability of our gate, which are 0.90, 0.83 and
0.73, respectively.Comment: 4 pages, 2 figures. v2 contains new data corresponding to improved
gate operation. Figure quality slightly reduced for arXi
Experimental demonstration of Shor's algorithm with quantum entanglement
Shor's powerful quantum algorithm for factoring represents a major challenge
in quantum computation and its full realization will have a large impact on
modern cryptography. Here we implement a compiled version of Shor's algorithm
in a photonic system using single photons and employing the non-linearity
induced by measurement. For the first time we demonstrate the core processes,
coherent control, and resultant entangled states that are required in a
full-scale implementation of Shor's algorithm. Demonstration of these processes
is a necessary step on the path towards a full implementation of Shor's
algorithm and scalable quantum computing. Our results highlight that the
performance of a quantum algorithm is not the same as performance of the
underlying quantum circuit, and stress the importance of developing techniques
for characterising quantum algorithms.Comment: 4 pages, 5 figures + half-page additional online materia
Estimation of illicit drug consumption in urban areas based on human metabolism, wastewater data and biodegradation in sewer networks
Fabrication of high quality plan-view TEM specimens using the focused ion beam
We describe a technique using a focused ion beam instrument to fabricate high quality plan-view specimens for transmission electron microscopy studies. The technique is simple, site-specific and is capable of fabricating multiple large, >100 μm2 electron transparent windows within epitaxially-grown thin films. A film of La0.67Sr0.33MnO3 is used to demonstrate the technique and its structural and functional properties are surveyed by high resolution imaging, electron spectroscopy, atomic force microscopy and Lorentz electron microscopy. The window is demonstrated to have good thickness uniformity and a low defect density that does not impair the film’s Curie temperature. The technique will enable the study of in–plane structural and functional properties of a variety of epitaxial thin film systems
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Perfusion assessment in rat spinal cord tissue using photoplethysmography and laser Doppler flux measurements
Animal models are widely used to investigate the pathological mechanisms of spinal cord injury (SCI), most commonly in rats. It is well known that compromised blood flow caused by mechanical disruption of the vasculature can produce irreversible damage and cell death in hypoperfused tissue regions and spinal cord tissue is particularly susceptible to such damage. A fiberoptic photoplethysmography (PPG) probe and instrumentation system were used to investigate the practical considerations of making measurements from rat spinal cord and to assess its suitability for use in SCI models. Experiments to assess the regional perfusion of exposed spinal cord in anesthetized adult rats using both PPG and laser Doppler flowmetry (LDF) were performed. It was found that signals could be obtained reliably from all subjects, although considerable intersite and intersubject variability was seen in the PPG signal amplitude compared to LDF. We present results from 30 measurements in five subjects, the two methods are compared, and practical application to SCI animal models is discussed
“everything in one place”
Purpose: To describe older adults’ perspectives on a new patient education
manual for the recovery process after hip fracture. Materials and methods: The
Fracture Recovery for Seniors at Home (FReSH) Start manual is an evidence-
based manual for older adults with fall-related hip fracture. The manual aims
to support the transition from hospital to home by facilitating self-
management of the recovery process. We enrolled 31 community-dwelling older
adults with previous fall-related hip fracture and one family member. We
collected data using a telephone-based questionnaire with eight five-point
Likert items and four semi-structured open-ended questions to explore
participants’ perceptions on the structure, content, and illustration of the
manual. The questionnaire also asked participants to rate the overall utility
(out of 10 points) and length of the manual. We used content analysis to
describe main themes from responses to the open-ended interview questions.
Results: Participants’ ratings for structure, content, and illustrations
ranged from 4 to 5 (agree to highly agree), and the median usefulness rating
was 9 (10th percentile: 7, 90th percentile: 10). Main themes from the content
analysis included: ease of use and presentation; health literacy; illustration
utility; health care team delivery; general impression, information support
from hospital to home; emotional and decision-making support; and the novelty
of the manual. Conclusion: The FReSH Start manual was perceived as
comprehensive in content and acceptable for use with older adults post-fall-
related hip fracture. Participants expressed a need for delivery and
explanation of the manual by a health care team member
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