Pore formation during dehydration of polycrystalline gypsum observed and quantified in a time-series synchrotron radiation based X-ray micro-tomography experiment

We conducted an in-situ X-ray micro-computed tomography heating experiment at the Advanced Photon Source (USA) to dehydrate an unconfined 2.3 mm diameter cylinder of Volterra Gypsum. We used a purpose-built X-ray transparent furnace to heat the sample to 388 K for a total of 310 min to acquire a three-dimensional time-series tomography dataset comprising nine time steps. The voxel size of 2.2 μm3 proved sufficient to pinpoint reaction initiation and the organization of drainage architecture in space and time. We observed that dehydration commences across a narrow front, which propagates from the margins to the centre of the sample in more than four hours. The advance of this front can be fitted with a square-root function, implying that the initiation of the reaction in the sample can be described as a diffusion process. Novel parallelized computer codes allow quantifying the geometry of the porosity and the drainage architecture from the very large tomographic datasets (20483 voxels) in unprecedented detail. We determined position, volume, shape and orientation of each resolvable pore and tracked these properties over the duration of the experiment. We found that the pore-size distribution follows a power law. Pores tend to be anisotropic but rarely crack-shaped and have a preferred orientation, likely controlled by a pre-existing fabric in the sample. With on-going dehydration, pores coalesce into a single interconnected pore cluster that is connected to the surface of the sample cylinder and provides an effective drainage pathway. Our observations can be summarized in a model in which gypsum is stabilized by thermal expansion stresses and locally increased pore fluid pressures until the dehydration front approaches to within about 100 μm. Then, the internal stresses are released and dehydration happens efficiently, resulting in new pore space. Pressure release, the production of pores and the advance of the front are coupled in a feedback loop.

The feral horse foot. Part A : observational study of the effect of environment on the morphometrics of the feet of 100 Australian feral horses

Aim To better understand the morphology of, and the effect of different travel patterns and varying substrate environments on, the feral horse foot to better manage the feet of domestic horses. Methods The left forefeet of 20 adult feral horses from each of five geographically separated populations in Australia (n = 100) were investigated. Populations were selected on the basis of substrate hardness under foot and the amount of travel typical for the population. Feet were radiographed and photographed and 40 morphometric measurements of each foot were obtained. Results Of the 40 parameters, 37 differed significantly (P < 0.05) among the populations, which suggested that substrate hardness and travel distance have an effect on foot morphology. Harder substrates and longer travel distances were associated with short hoof walls and minimal hoof wall flaring. Softer substrates and moderate travel distances were associated with long flared walls, similar to that of typical untrimmed feet of domestic horses. Conclusions The morphology of the feral horse foot appeared to be affected by the distance travelled and by the abrasive qualities and mechanical properties of the substrate under foot. There were marked differences in some conformation parameters between the feral horses in the current study and domestic horses in previous studies. Although the conformation of the feral horse foot may have some prescriptive value, concerns regarding abnormal foot anatomy warrant further investigation.

YBa2Cu3O7-x films on yttria-stabilized ZrO2 substrates : influence of the substrate morphology

c-axis-oriented YBa2Cu3O7-x (YBCO) thin films were laser deposited on (001) yttria-stabilized ZrO2 (YSZ) substrates with different surface morphologies. The in-plane orientation of the films on smooth substrates was sensitive to the deposition conditions, often resulting in mixed orientations. However, a strongly dominating [110] YBCO//[110]YSZ orientation was obtained at a deposition temperature of 770°C. Films on substrates with surface steps, induced by depositing a homoepitaxial buffer layer or by thermally annealing the substrate, had a [110]YBCO//[100]YSZ orientation when deposited at the same temperature. It was concluded that the [110]YBCO//[100] YSZ orientation was promoted by a graphoepitaxial mechanism. Films prepared under identical conditions on smooth and stepped substrates grew with extended c axes on the former. It is proposed that the extension can be induced by disorder, invoked by a low oxygen pressure and a low density of adsorption sites. The disorder may be eliminated by either an increase of the oxygen pressure or an increase of the density of adsorption sites in the form of steps. The film microstructure influenced the microwave surface resistance, which was similar for films with one exclusive in-plane orientation and higher for films with mixed orientations. The films on the stepped surfaces had superior superconducting properties; inductive measurements gave a Tc onset of 88 K, a ΔT(90%-10%) c of 0.2 K, and the transport jc was 1.5×106 A/cm2 at 83 K, for films on substrates with homoepitaxial buffer layers.

Twelve : the best Of IMP's 100 Songs Project 2011

12 Original recordings curated by leading national industry figures. It’s a 12 track album full of remixed, rerecorded and rejigged tracks from the project that were shortlisted by our friends at MGM Distribution, Music Sales, and EMI Music Australia. The TWELVE album is already receiving critical acclaim from Australia's music industry.

Eleven : best of 100 Songs Project 2012

Eleven original recordings curated by leading industry figures. This is a compilation album from QUT's 2012 100 Songs project. It's called Eleven: Best of 100 Songs Project 2012 and was released in May 2013. It’s an 11 track album with a bonus track, full of remixed, rerecorded and rejigged tracks from the project that were shortlisted by our friends at MGM Distribution, Mushroom Music, Island Records and Music Sales Australia. The Eleven album is already receiving critical acclaim from Australia's music industry.

Indie 100 2013

The Independent Music Project is centred around the development and creation of new music, and includes research into copyright, business models of the future, new technologies, and new audiences. The music industry is undergoing the most radical changes it has faced in almost a century. New digital technologies have made the production, distribution, and promotion of recorded music accessible to anyone with a personal computer. People can now make high-quality digital copies of music and distribute them globally within minutes. Even bastions of the established industries, such as EMI and Columbia, are struggling to make sense of the new industry terrain. The whole employment picture has changed just as radically for people who wish to make a living from music. In Australia, many of the avenues that provided employment for musicians have either disappeared or dramatically shrunk. The advertising industry no longer provides the level of employment it used to prior to the Federal deregulation of the industry in 1992. In many places, new legislative pressures on inner-city and suburban venues have diminished the number of performance spaces that musicians can work in. Just as quickly, new sectors have opened to professional musicians: computer games, ringtones, sound-enabled toys and web advertising all present new opportunities to the enterprising musician. The opportunity to distribute music internationally without being signed to a major label is very attractive to many aspiring and established professionals. No doubt the music industry will face many more challenges as technologies continue to change, as global communication gets easier and faster, and as the challenges to copyright proliferate and change. These challenges cannot be successfully met on a single front. They require research and expertise from all sectors being affected, and this is why the independent music project (IMP) exists.

Indie 100 2014

The Independent Music Project is centred around the development and creation of new music, and includes research into copyright, business models of the future, new technologies, and new audiences. The music industry is undergoing the most radical changes it has faced in almost a century. New digital technologies have made the production, distribution, and promotion of recorded music accessible to anyone with a personal computer. People can now make high-quality digital copies of music and distribute them globally within minutes. Even bastions of the established industries, such as EMI and Columbia, are struggling to make sense of the new industry terrain. The whole employment picture has changed just as radically for people who wish to make a living from music. In Australia, many of the avenues that provided employment for musicians have either disappeared or dramatically shrunk. The advertising industry no longer provides the level of employment it used to prior to the Federal deregulation of the industry in 1992. In many places, new legislative pressures on inner-city and suburban venues have diminished the number of performance spaces that musicians can work in. Just as quickly, new sectors have opened to professional musicians: computer games, ringtones, sound-enabled toys and web advertising all present new opportunities to the enterprising musician. The opportunity to distribute music internationally without being signed to a major label is very attractive to many aspiring and established professionals. No doubt the music industry will face many more challenges as technologies continue to change, as global communication gets easier and faster, and as the challenges to copyright proliferate and change. These challenges cannot be successfully met on a single front. They require research and expertise from all sectors being affected, and this is why the independent music project (IMP) exists.

100 Songs Project 2011

The Independent Music Project is centred around the development and creation of new music, and includes research into copyright, business models of the future, new technologies, and new audiences. The music industry is undergoing the most radical changes it has faced in almost a century. New digital technologies have made the production, distribution, and promotion of recorded music accessible to anyone with a personal computer. People can now make high-quality digital copies of music and distribute them globally within minutes. Even bastions of the established industries, such as EMI and Columbia, are struggling to make sense of the new industry terrain. The whole employment picture has changed just as radically for people who wish to make a living from music. In Australia, many of the avenues that provided employment for musicians have either disappeared or dramatically shrunk. The advertising industry no longer provides the level of employment it used to prior to the Federal deregulation of the industry in 1992. In many places, new legislative pressures on inner-city and suburban venues have diminished the number of performance spaces that musicians can work in. Just as quickly, new sectors have opened to professional musicians: computer games, ringtones, sound-enabled toys and web advertising all present new opportunities to the enterprising musician. The opportunity to distribute music internationally without being signed to a major label is very attractive to many aspiring and established professionals. No doubt the music industry will face many more challenges as technologies continue to change, as global communication gets easier and faster, and as the challenges to copyright proliferate and change. These challenges cannot be successfully met on a single front. They require research and expertise from all sectors being affected, and this is why the independent music project (IMP) exists.

Impact of al passivation and cosputter on the structural property of β-FeSi2 for Al-Doped β-FeSi2/ n -Si(100) based solar cells application

The aluminum (Al) doped polycrystalline p-type β-phase iron disilicide (p-β-FeSi2) is grown by thermal diffusion of Al from Al-passivated n-type Si(100) surface into FeSi2 during crystallization of amorphous FeSi2 to form a p-type β-FeSi 2/n-Si(100) heterostructure solar cell. The structural and photovoltaic properties of p-type β-FeSi2/n-type c-Si structures is then investigated in detail by using X-ray diffraction, Raman spectroscopy, transmission electron microscopy analysis, and electrical characterization. The results are compared with Al-doped p-β-FeSi2 prepared by using cosputtering of Al and FeSi2 layers on Al-passivated n-Si(100) substrates. A significant improvement in the maximum open-circuit voltage (Voc) from 120 to 320 mV is achieved upon the introduction of Al doping through cosputtering of Al and amorphous FeSi2 layer. The improvement in Voc is attributed to better structural quality of Al-doped FeSi2 film through Al doping and to the formation of high quality crystalline interface between Al-doped β-FeSi2 and n-type c-Si. The effects of Al-out diffusion on the performance of heterostructure solar cells have been investigated and discussed in detail.

Ionic transport in (PEG)x LiBr systems

Ionic conductivity in (PEG)(x)LiBr systems is measured using the complex impedance method in the temperature range -20 degrees C to 100 degrees C. For x = 6 and 10, above a certain concentration dependent temperature T-c, a power law fit based on mode coupling theory is seen to better explain the data than the Vogel-Tamman-Fulcher (VTF) expression. Li-7 NMR linewidth measurements indicate two regions of motional narrowing, one attributable to segmental motion and the other to translational diffusion.

Ion beam processing of oriented CuO films deposited on (100) YSZ by laser ablation

A systematic study of Ar ion implantation in cupric oxide films has been reported. Oriented CuO films were deposited by pulsed excimer laser ablation technique on (1 0 0) YSZ substrates. X-ray diffraction (XRD) spectra showed the highly oriented nature of the deposited CuO films. The films were subjected to ion bombardment for studies of damage formation, Implantations were carried out using 100 keV Arf over a dose range between 5 x 10(12) and 5 x 10(15) ions/cm(2). The as-deposited and ion beam processed samples were characterized by XRD technique and resistance versus temperature (R-T) measurements. The activation energies for electrical conduction were found from In [R] versus 1/T curves. Defects play an important role in the conduction mechanism in the implanted samples. The conductivity of the film increases, and the corresponding activation energy decreases with respect to the dose value.

pi-conjugation and conformation in a semiconducting polymer: small angle x-ray scattering study

Small angle x-ray scattering (SAXS) in a poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) solution has shown the important role of pi-electron conjugation in controlling the chain conformation and assembly. By increasing the extent of conjugation from 30 to 100%, the persistence length (l(p)) increases from 20 to 66 angstrom. Moreover, a pronounced second peak in the pair distribution function has been observed in a fully conjugated chain, at larger length scales. This feature indicates that the chain segments tend to self-assemble as the conjugation along the chain increases. Xylene enhances the rigidity of the PPV backbone to yield extended structures, while tetrahydrofuran solvates the side groups to form compact coils in which the lp is much shorter.

NMR relaxation study of disorder in the mixed system BP x GPI(1-x) and the low temperature transition from classical to quantum rotation

1H NMR spin-lattice relaxation time (T1) studies have been carried out in the temperature range 100 K to 4 K, at two Larmor frequencies 11.4 and 23.3 MHz, in the mixed system of betaine phosphate and glycine phosphite (BPxGPI(1-x)), to study the effects of disorder on the proton group dynamics. Analysis of T1 data indicates the presence of a number of inequivalent methyl groups and a gradual transition from classical reorientations to quantum tunneling rotations. At lower temperatures, microstructural disorder in the local environments of the methyl groups, result in a distribution in the activation energy (Ea) and the torsional energy gap (E01). For certain values of x, the magnetisation recovery shows biexponential behaviour at lower temperatures.

X-ray absorption spectra of niobium dichalcogenides and their first-row transition-metal intercalates

X-ra!. K-absorption spectra of niobium in niobium dichalcogenides. namely NbS, and NbSe, and their first-row transition-metal intercalates Mi P 3N bSz (M = Cr. Mn. Fe. Co. Ni) and Ml#,NbSe2 (M = Fe. CO). have been measured together with those in niobium metal. The spectra of these materials are \er? similar to one another. They reflect the transitions to the partially filled niobium d band with some p character. A bariety of x-ray absorption nearedge structures (XASES) associated with the K edges of intercalated atoms are also presented and discussed.

Study of effects of dopants on structure of vitreous semiconductors (GeSe3.5)100-xMx (M = Bi, Sb) using high pressure techniques

An investigation of the problem of controlled doping of amorphous chalcogenide semiconductors utilizing a Bridgman anvil high pressure technique, has been undertaken. Bulk amorphous semiconducting materials (GeSe3.5)100-x doped with M = Bi (x = 2, 4, 10) and M = Sb (x = 10) respectively are studied up to a pressure of 100 kbar down to liquid nitrogen temperature, with a view to observe the impurity induced modifications. Measurement of the electrical conductivity of the doped samples under quasi-hydrostatic pressure reveals that the pressure induced effects in lightly doped (2 at % Bi) and heavily doped (x = 4, 10) semiconductors are markedly different. The pressure effects in Sb-doped semiconductors are quite different from those in Bi-doped material.