Lifting Leucaena adoption in north Queensland

The introduction and successful establishment of leucaena has the potential to double annual live-weight gains and increase carrying capacity for beef enterprises. The low rate of adoption of leucaena by graziers across north Queensland appears to be linked closely to establishment costs, potential frost impact in some areas, tree clearing regulations, low confidence in plant establishment and the impact of psyllid attack on productivity. The Producer Demonstration Site (PDS) at Whitewater Station, near Mount Surprise, included both a 40 ha site aimed at improving industry understanding of establishment costs and options, as well as a one hectare replicated experiment to assess the palatability of new leucaena lines bred specifically for psyllid resistance. The leucaena planting on a 40 ha lightly timbered site was fully established in mid-2016 enabling assessment of management requirements and potential productivity-profitability gains on uncleared land. The palatability assessment of the four new psyllid tolerant lines was conducted by the Department of Agriculture and Fisheries (DAF) and the University of Queensland (UQ) in December 2014 and May 2016. With the aid of this data, all four lines were confirmed to be palatable with Line 12 (Redlands) selected and released to commercial partners. Based on these preliminary study results, UQ and Meat and Livestock Australia (MLA) proceeded to commercialise the Redlands variety by contracting two seed producers in Central Queensland. Commercial seed is now available for producers to plant in the 2019 growing season

Design of a Flight Controller for an Unmanned Research Vehicle with Control Surface Failures Using Quantitative Feedback Theory

This thesis describes the application of the multiple-input multiple- output (MIMO) Quantitative Feedback Theory (QFT) design technique to the design of a digital flight control system for the Lambda Unmanned Research Vehicle (URV). The QFT technique allows the synthesis of a control system which is robust in the presence of structured plant uncertainties. Uncertainties considered in this design are the aircraft\u27s plant variation within the flight envelope and the effects of damage to aircraft control surfaces. Mathematical models of control surface failure effects on aircraft dynamics are derived and used to modify an existing small perturbation model of the Lambda. The QFT technique is applied to design a control system utilizing aircraft pitch rate, roll rate and sideslip angle as feedback variables. The inherent cross-coupling rejection qualities of QFT and an aileron-rudder interconnect are utilized to design a control system which results in a coordinated flight. An outer-loop autopilot is then designed around the QFT controller to further assist turn coordination. Sensor noise effects on aircraft states are also analyzed. Quantitative feedback theory, Flight control system, Aircraft damage

Multivariate Statistical Methodologies used in In-vitro Raman Spectroscopy: Simulations and Applications for Drug and Nanoparticle Interactions

Raman spectroscopy is a growing technology in the fields of in-vitro drug and nanoparticle screening. The label free capability provided by vibrational spectroscopy, as well as the ability of the technique to probe the chemical nature of samples, makes it a good candidate for use in these fields. Crucial to the progress of these methods is the development and validation of robust and accurate multivariate statistical analysis protocols. In this thesis, both established and novel methods are examined using both real and simulated datasets. In particular, simulated datasets are used to validate and assess the accuracy of these methods in a spectroscopic setting. Firstly, partial least squares regression (PLSR) is examined using a simulated model based on real experimental data. This is applied to investigate the application of the algorithm to continuously varying data with known spectral perturbations introduced over a range of concentrations and responses. The results show that, while PLSR is valid for some dose ranges, sub-lethal, low concentrations and thus subtle spectral changes in the data may lead to difficulties in model construction. Multiple trends present in the data were also investigated and possible model error based on spectral bleedthrough in the regression coefficients RCs is explored. Principal component analysis (PCA) was also investigated using simulated datasets based on known changes in the data. Some of the limitations of PCA for data partitioning and trend analysis are overcome by a novel variant termed, ‘seeded’ PCA. 1st and 2nd derivative data is also explored for improvements in Raman spectral analysis using seeded PCA

Raman Spectroscopy in Nanomedicine: Current Status and Future Perspectives

Raman spectroscopy is a branch of vibration spectroscopy which is capable of probing the chemical composition of materials. Recent advances in Raman microscopy have added significantly to the range of applications which now extend from medical diagnostics to exploring interfaces between biological organisms and nanomaterials. In this review, Raman is introduced in a general context, highlighting some of the areas in which the technique has found success in the past, as well as some of the potential benefits it offers over other analytical modalities. The subset of Raman techniques which specifically probe the nanoscale, namely Surface Enhanced and Tip Enhanced Raman Spectroscopy, will be described and specific applications relevant to nanomedical applications will be reviewed. Progress in the use of traditional label-free Raman applied to investigation of nanoscale interactions will be described, and recent developments in Coherent Anti-Stokes Raman Scattering will be explored, particularly applications to biomedical and nanomedical fields

Deterministic Domain Wall Motion Orthogonal To Current Flow Due To Spin Orbit Torque.

Spin-polarized electrons can move a ferromagnetic domain wall through the transfer of spin angular momentum when current flows in a magnetic nanowire. Such current induced control of a domain wall is of significant interest due to its potential application for low power ultra high-density data storage. In previous reports, it has been observed that the motion of the domain wall always happens parallel to the current flow - either in the same or opposite direction depending on the specific nature of the interaction. In contrast, here we demonstrate deterministic control of a ferromagnetic domain wall orthogonal to current flow by exploiting the spin orbit torque in a perpendicularly polarized Ta/CoFeB/MgO heterostructure in presence of an in-plane magnetic field. Reversing the polarity of either the current flow or the in-plane field is found to reverse the direction of the domain wall motion. Notably, such orthogonal motion with respect to current flow is not possible from traditional spin transfer torque driven domain wall propagation even in presence of an external magnetic field. Therefore the domain wall motion happens purely due to spin orbit torque. These results represent a completely new degree of freedom in current induced control of a ferromagnetic domain wall

POLOCALC: a Novel Method to Measure the Absolute Polarization Orientation of the Cosmic Microwave Background

We describe a novel method to measure the absolute orientation of the polarization plane of the CMB with arcsecond accuracy, enabling unprecedented measurements for cosmology and fundamental physics. Existing and planned CMB polarization instruments looking for primordial B-mode signals need an independent, experimental method for systematics control on the absolute polarization orientation. The lack of such a method limits the accuracy of the detection of inflationary gravitational waves, the constraining power on the neutrino sector through measurements of gravitational lensing of the CMB, the possibility of detecting Cosmic Birefringence, and the ability to measure primordial magnetic fields. Sky signals used for calibration and direct measurements of the detector orientation cannot provide an accuracy better than 1 deg. Self-calibration methods provide better accuracy, but may be affected by foreground signals and rely heavily on model assumptions. The POLarization Orientation CALibrator for Cosmology, POLOCALC, will dramatically improve instrumental accuracy by means of an artificial calibration source flying on balloons and aerial drones. A balloon-borne calibrator will provide far-field source for larger telescopes, while a drone will be used for tests and smaller polarimeters. POLOCALC will also allow a unique method to measure the telescopes' polarized beam. It will use microwave emitters between 40 and 150 GHz coupled to precise polarizing filters. The orientation of the source polarization plane will be registered to sky coordinates by star cameras and gyroscopes with arcsecond accuracy. This project can become a rung in the calibration ladder for the field: any existing or future CMB polarization experiment observing our polarization calibrator will enable measurements of the polarization angle for each detector with respect to absolute sky coordinates.Comment: 15 pages, 5 figures, Accepted by Journal of Astronomical Instrumentatio

Low-input, high quality legume hays for north Queensland

Perennial herbaceous legumes grown for hay can improve beef and dairy production in north Queensland through providing affordable high-quality (digestible protein) dry season feed. Eleven Arachis ecotypes (A. pintoi (5), A. glabrata (3), A. paraguariensis (2) and A. kretschmeri (1)), two Stylosanthes guianensis varieties and two commercially recommended Medicago sativa varieties were grown for hay under irrigation using standardised populations in replicated small-plots over two wet seasons (summer) and compared for dry matter production and fodder quality using 8 week cutting cycles. All initially grew well but M. sativa plants were damaged by leaf and stem diseases during wet summer periods reducing leaf and stem growth and resulting in open, weedy stands; the Arachis and Stylosanthes were relatively unaffected and exhibited strong summer-dominant growth throughout the study. There were significant species and varietal differences in biomass production and some A. pintoi, M. sativa and S. guianensis produced over 30 T DM (stem plus leaf above 5 cm cut height) over 19 months. Arachis glabrata also yielded well (16-18 T DM) following a prolonged establishment phase. Feed quality was high for all legumes compared, and overall best in the Arachis spp., with crude protein percentages mostly above 16% and high levels of protein and carbohydrate rumen degradability

Spectral Pre and Post Processing for Infrared and Raman Spectroscopy of Biological Tissues and Cells

Vibrational Spectroscopy, both infrared absorption and Raman spectroscopy, have attracted increasing attention for biomedical applications, from in vivo and ex vivo disease diagnostics and screening, to in vitro screening of therapeutics. There remain, however, many challenges related to the accuracy of analysis of physically and chemically inhomogeneous samples, across heterogeneous sample sets. Data preprocessing is required to deal with variations in instrumental responses and intrinsic spectral backgrounds and distortions in order to extract reliable spectral data. Data postprocessing is required to extract the most reliable information from the sample sets, based on often very subtle changes in spectra associated with the targeted pathology or biochemical process. This review presents the current understanding of the factors influencing the quality of spectra recorded and the pre-processing steps commonly employed to improve on spectral quality. It further explores some of the most common techniques which have emerged for classification and analysis of the spectral data for biomedical applications. The importance of sample presentation and measurement conditions to yield the highest quality spectra in the first place is emphasised, as is the potential of model simulated datasets to validate both pre- and post- processing protocols

Passage and survival of Acaciella angustissima (Mill.) Britton & Rose and Aeschynomene paniculata Willd. ex Vogel seed through the sheep gut

Acaciella angustissima (syn. Acacia angustissima) (white ball acacia) and Aeschynomene paniculata Willd. ex Vogel (pannicle joint vetch), were rejected for release after their identification as potential weeds in pasture evaluation trials. These plants are now targeted for control and, where possible, eradication from old experimental sites across Queensland. It is suspected that domestic livestock, feral and native animals contribute to the movement of these seeds through the ingestion and defecation of viable seeds across the landscape. This aspect was explored by feeding the intact seeds of these two species to sheep in metabolism cages. Sheep faeces were collected each day for 5 days after which time the faeces were sieved and the surviving intact seeds were then collected, counted and germination tests undertaken. The results show that seeds of both species pass through sheep with most seeds being passed after 48 h with a percentage of these seeds being viable. Of the number of seeds fed, 4.25% were recovered for A. angustissima and 1.4% for A. paniculata. Seed recovered from the faeces had 0% and 13% germination for A. angustissima and A. paniculata respectively, but with additional post-digestion hot water scarification germination increased to 75% and 33% for A. angustissima and A. paniculata respectively. This paper discusses these results and the implications for the possible spread of these species across the northern Australian landscape

A laboratory study to estimate pore geometric parameters of sandstones using complex conductivity and nuclear magnetic resonance for permeability prediction

We estimate parameters from the Katz and Thompson permeability model using laboratory complex electrical conductivity (CC) and nuclear magnetic resonance (NMR) data to build permeability models parameterized with geophysical measurements. We use the Katz and Thompson model based on the characteristic hydraulic length scale, determined from mercury injection capillary pressure estimates of pore throat size, and the intrinsic formation factor, determined from multi-salinity conductivity measurements, for this purpose. Two new permeability models are tested, one based on CC data and another that incorporates CC and NMR data. From measurements made on forty-five sandstone cores collected from fifteen different formations, we evaluate how well the CC relaxation time and the NMR transverse relaxation times compare to the characteristic hydraulic length scale and how well the formation factor estimated from CC parameters compares to the intrinsic formation factor. We find: (1) the NMR transverse relaxation time models the characteristic hydraulic length scale more accurately than the CC relaxation time (R2 of 0.69 and 0.39 and normalized root mean square errors (NRMSE) of 0.16 and 0.20, respectively); (2) the CC estimated formation factor is well correlated with the intrinsic formation factor (NRMSE=0.23). We demonstrate that that permeability estimates from the joint-NMR-CC model (NRMSE=0.13) compare favorably to estimates from the Katz and Thompson model (NRMSE=0.074). This model advances the capability of the Katz and Thompson model by employing parameters measureable in the field giving it the potential to more accurately estimate permeability using geophysical measurements than are currently possible