Commercial scale economic evaluation of post-harvest cane cleaning to maximise the returns to the supply chain.

This project examined three cane supply treatments; Commercial harvesting, Low Loss harvesting and Low Loss Harvesting plus cleaning; to determine if post-harvest cane cleaning offered benefits over harvesting alone. As a basic concept, it was expected that reducing harvester extractor fan speed would reduce cane loss, resulting in increased CCS yield but also increased trash content, and that the post-harvest cane cleaning operation would remove the additional trash, maintaining the higher CCS yield. To facilitate this project, a mobile cane cleaner (MCC) was purchased from Norris ECT by SRA. The MCC was leased by the project from SRA. Major modifications to the cleaning chamber of the NorrisECT 180 mobile cane cleaner (MCC 180) were necessary. The MCC was a prototype machine not suitable for commercial use. The results did support the expectation of higher CCS yield with lower extractor fan speed, but much of the higher yield measured by low loss harvesting was lost after post-harvest cane cleaning. Economic analysis quantified harvesting costs and the resulting product income. In an experiment on Rajinder Singh’s farm, the treatment with post-harvest cane cleaning was found to be less economically attractive than the normal harvesting treatment, even with the lower transport cost in getting cane to Mossman Mill, a distance of 95 km. The project did not measure an increase in CCS yield from the low loss harvesting plus cane cleaning treatment to improve upon sugar income

Millisecond Pulsars as Probes of Mass Segregation in the Galactic Center

We propose a simple test for the existence of a cluster of black hole remnants around Sgr A* that is based on a small sample of any type of Galactic Center objects, provided they are substantially less massive than the black holes and constitute part of an old (> 1 Gyr) population. The test relies on the fact that, under the presence of such a cluster of heavy remnants and because of energy equipartition, lower mass objects would be expelled from the central regions and settle into a distribution very different than the cusp expected to be induced by the supermassive black hole alone. We show that with a sample of just 50 objects and using only their angular positions on the sky relative to Sgr A* it is possible to clearly differentiate between a distribution consistent with the presence of the cluster of black holes and a power-law cusp distribution. We argue that millisecond pulsars might currently be the best candidate to perform this test, because of the large uncertainties involved in the age determination of less exotic objects. In addition, by measuring their first and second period derivatives, millisecond pulsars offer the rare opportunity of determining the complete phase space information of the objects. We show that this extra information improves the detection of mass segregation by about 30%.Comment: 16 pages, 1 Postscript figure; version accepted for publication in Ap

Clustering and correlates of screen-time and eating behaviours among young adolescents

Background: Screen-time and eating behaviours are associated in adolescents, but few studies have examined the clustering of these health behaviours in this age group. The identification of clustered health behaviours, and influences on adolescents’ clustered health behaviours, at the time when they are most likely to become habitual, is important for intervention design. The purpose of this study was to assess the prevalence and clustering of health behaviours in adolescents, and examine the sociodemographic, individual, behavioural, and home social and physical environmental correlates of clustered health behaviours. Methods: Adolescents aged 11–12 years (n = 527, 48% boys) completed a questionnaire during class-time which assessed screen-time (ST), fruit and vegetable (FV), and energy-dense (ED) snack consumption using a Food Frequency Questionnaire. Health behaviours were categorised into high and low frequencies based on recommendations for FV and ST and median splits for ED snacks. Adolescents reported on their habits, self-efficacy, eating at the television (TV), eating and watching TV together with parents, restrictive parenting practices, and the availability and accessibility of foods within the home. Behavioural clustering was assessed using an observed over expected ratio (O/E). Correlates of clustered behaviours were examined using multivariate multinomial logistic regression. Results: Approximately 70% reported having two or three health risk behaviours. Overall, O/E ratios were close to 1, which indicates clustering. The three risk behaviour combination of low FV, high ED, and high ST occurred more frequently than expected (O/E ratio = 1.06 95% CI 1.01, 1.15. Individual, behavioural, and social and physical home environmental correlates were differentially associated with behavioural clusters. Correlates consistently associated with clusters included eating ED snacks while watching TV, eating at the TV with parents, and the availability and accessibility of ED snack foods within the home. Conclusions: There is a high prevalence of screen time and unhealthy eating, and screen time is coupled with unhealthy dietary behaviours. Strategies and policies are required that simultaneously address reductions in screen time and changes to habitual dietary patterns, such as TV snacking and snack availability and accessibility. These may require a combination of individual, social and environmental changes alongside conscious and more automatic (nudging) strategies

Molecular scale contact line hydrodynamics of immiscible flows

From extensive molecular dynamics simulations on immiscible two-phase flows, we find the relative slipping between the fluids and the solid wall everywhere to follow the generalized Navier boundary condition, in which the amount of slipping is proportional to the sum of tangential viscous stress and the uncompensated Young stress. The latter arises from the deviation of the fluid-fluid interface from its static configuration. We give a continuum formulation of the immiscible flow hydrodynamics, comprising the generalized Navier boundary condition, the Navier-Stokes equation, and the Cahn-Hilliard interfacial free energy. Our hydrodynamic model yields interfacial and velocity profiles matching those from the molecular dynamics simulations at the molecular-scale vicinity of the contact line. In particular, the behavior at high capillary numbers, leading to the breakup of the fluid-fluid interface, is accurately predicted.Comment: 33 pages for text in preprint format, 10 pages for 10 figures with captions, content changed in this resubmissio

Criticality in coupled quantum spin-chains with competing ladder-like and two-dimensional couplings

Motivated by the geometry of spins in the material CaCu$_2$O$_3$, we study a two-layer, spin-half Heisenberg model, with nearest-neighbor exchange couplings J and \alpha*J along the two axes in the plane and a coupling J_\perp perpendicular to the planes. We study these class of models using the Stochastic Series Expansion (SSE) Quantum Monte Carlo simulations at finite temperatures and series expansion methods at T=0. The critical value of the interlayer coupling, J_\perp^c, separating the N{\'e}el ordered and disordered ground states, is found to follow very closely a square root dependence on $\alpha$. Both T=0 and finite-temperature properties of the model are presented.Comment: 9 pages, 11 figs., 1 tabl

Quantum fluctuations of charge order induce phonon softening in a superconducting cuprate

Quantum phase transitions play an important role in shaping the phase diagram of high-temperature cuprate superconductors. These cuprates possess intertwined orders which interact strongly with superconductivity. However, the evidence for the quantum critical point associated with the charge order in the superconducting phase remains elusive. Here we show the short-range charge orders and the spectral signature of the quantum fluctuations in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) near the optimal doping using high-resolution resonant inelastic X-ray scattering. On performing calculations through a diagrammatic framework, we discovered that the charge correlations significantly soften several branches of phonons. These results elucidate the role of charge order in the LSCO compound, providing evidence for quantum critical scaling and discommensurations associated with charge order

Quantum fluctuations of charge order induce phonon softening in a superconducting cuprate

Quantum phase transitions play an important role in shaping the phase diagram of high-temperature cuprate superconductors. These cuprates possess intertwined orders which interact strongly with superconductivity. However, the evidence for the quantum critical point associated with the charge order in the superconducting phase remains elusive. Here we show the short-range charge orders and the spectral signature of the quantum fluctuations in La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) near the optimal doping using high-resolution resonant inelastic X-ray scattering. On performing calculations through a diagrammatic framework, we discovered that the charge correlations significantly soften several branches of phonons. These results elucidate the role of charge order in the LSCO compound, providing evidence for quantum critical scaling and discommensurations associated with charge order