Reducing the redundancy of financial ratios and assessing the stability of financial patterns

The purpose of this study was to examine the financial patterns of Australian industrial firms along the lines of Pinches et al.’s (1973; 1975) study. The financial ratios used in prior Australian corporate failure studies were used to derive a reduced set of factors that was predictive of corporate failure (e.g., Castagna & Matolesy, 1981: Booth, 1983). These factors were examined for the short – and long-term stability of these factors. The set of firms used was selected from FINSELECT database, which covered the period from 1989 to 1997. A random list of 199 Australian industrial firms that survived between 1989 and 1997 was selected. A total of thirty-one unique financial ratios were calculated based on the models derived in prior Australian failure prediction studies. These financial rations were factor analysed. The financial factors that were predictive of corporate failure were Return on Investment, Short-Term Liquidity (I and II), Financial Leverage (I and II) and Decomposition Measure

Rheological characterisation of thermally hydrolysed waste activated sludge

Hydrothermal sludge processing is a branch of sludge treatment technologies finding increased adoption in modern sewage treatment processes. These technologies involve the use of elevated temperature conditions to desirably alter sludge characteristics in the liquid phase. Benefits of these processes, such as thermal hydrolysis pre-treatment, include increased biogas production during anaerobic digestion, improved sludge dewaterability, sterilization of sludge, and improved transport operations due to desirable rheological enhancements. Sludge rheology plays a significant role in the design and operation of these sludge-handling processes. Despite this, rheological studies related to sludge in hydrothermal processing conditions is very scarce. Therefore, a better understanding of sludge’s rheological properties, especially at the high temperature conditions encountered during hydrothermal processing is required for better optimization of these processes. This study investigates the rheological characteristics of thickened waste activated sludge (WAS) in thermal hydrolysis (TH) processes. Using in-situ rheometric measurements, changes in the sludge’s flow properties due to the impact of treatment conditions (temperature, time, and sludge concentration) were examined. These changes were related to the solubilisation of sludge organics, measured by the chemical oxygen demand (COD) of sludge. Based on these observations, equations were derived to predict the rheological properties of sludge at various conditions of TH and its link to COD. Furthermore, the viscoelastic properties of the thickened, untreated and thermally-treated sludges were studied in order to characterize sludge’s solid-like properties. A correlation was proposed to associate sludge’s viscoelastic data to flow curve data such that oscillatory measurement techniques could be used to collect steadyshear data which are traditionally obtained via rotational measurement. In-situ rheological measurements revealed WAS behaved as a shear-thinning, yield stress fluid which could be described by the Herschel-Bulkley model. Despite elevated treatment temperatures (80 – 140 °C), Newtonian flow behaviour was not observed at any time in the sludge. The flow behaviour of the sludge at all treatment conditions examined could be described by a single master curve. This means sludge’s flow behaviour was governed by a similar network of physical interactions regardless of its concentration or treatment conditions. As a result of TH, the apparent viscosity, η, and Herschel-Bulkley rheological parameters (yield stress, σc, and consistency index, k) were reduced irreversibly. The extent of this reduction followed a linear relationship with treatment temperature. The in-situ values of η, σc, and k were up to 92% lower compared to measurements after the thermally-treated sludge is cooled to ambient temperature. In-situ measurements also showed that η, σc, and k reduced gradually during TH at constant temperature, following a logarithmic relationship with treatment duration. This meant the solubilization effects of TH were a time-dependent process. At constant time, reduction of η, σc, and k in situ were described by a linear relationship with increasing sludge temperature (80 – 140 °C). At constant treatment time and temperature, η, σc, and k were increased with sludge concentration (7 – 13 wt%) following a power-law relationship. The effectiveness of sludge solubilisation during TH was not impacted by varying sludge concentrations, since the reduction of η, σc, and k were nearly constant between the different sludge concentrations. The solubilisation of sludge organics also followed a logarithmic time-dependent behaviour as shown by increasing values of COD in the soluble phase of the sludge during TH. This increase in sludge’s soluble COD (sCOD) indicated that the rheological changes observed during TH were due to the disintegration of sludge’s network structure. Accordingly, linear correlation existed between the reduction of rheological parameters (η, σc, and k) and the increase in sCOD. This correlation indicates the rheological measurement of sludge in situ can be used as a means to monitor the performance of hydrothermal processes. Viscoelastic measurements of the untreated and thermally treated sludges revealed gel-like behaviour in the linear viscoelastic region. The frequency and creep response of the sludges were described using a fractional Kelvin-Voigt model (FKV). With increasing treatment temperatures, the storage (G’) and loss (G”) moduli were reduced linearly, further indicating a weakening of structural components in the sludge, such as extracellular polymeric substances. This is reflected in the decreasing value of energy of cohesion, Ecwhich describes the strength of the three-dimensional sludge network. Viscoelastic data, as obtained from dynamic oscillatory measurements of the sludge could be related to the flow curve data of the sludge, as obtained via steady-shear measurements. A modified Cox-Merz relationship related the complex viscosity, η*(ω), to the steady shear viscosity, η(γ̇), by applying shift factors. More notably, raw values of dynamic viscosity, η’(ω), were nearly equal to η(γ̇) at equivalent shear rates. This meant that oscillatory measurement could readily describe steady-shear, flow data. Besides that, the yield stress of the sludge could also be estimated from the above shift factors and values of G’. Finally, the engineering implications of this observations and results in this study were discussed, highlighting the significance of correct determination of rheological parameters which are needed in the design and operation of unit operations

A review of wet air oxidation and thermal hydrolysistechnologies in sludge treatment

With rapid world population growth and strict environmental regulations, increasingly large volumes of sludge are being produced in today's wastewater treatment plants (WWTP) with limited disposal routes. Sludge treatment has become an essential process in WWTP, representing 50% of operational costs. Sludge destruction and resource recovery technologies are therefore of great ongoing interest. Hydrothermal processing uses unique characteristics of water at elevated temperatures and pressures to deconstruct organic and inorganic components of sludge. It can be broadly categorized into wet oxidation (oxidative) and thermal hydrolysis (non-oxidative). While wet air oxidation (WAO) can be used for the final sludge destruction and also potentially producing industrially useful by-products such as acetic acid, thermal hydrolysis (TH) is mainly used as a pre-treatment method to improve the efficiency of anaerobic digestion. This paper reviews current hydrothermal technologies, roles of wet air oxidation and thermal hydrolysis in sludge treatment, and challenges faced by these technologies

Benign intermuscular lipoma in a bitch

A case of intermuscular lipoma located between the external abdominal oblique and internal abdominal oblique muscles in a fourteen- year -old dog is described. Presenting signs, radiographic findings, surgical treatments and the follow-up treatment are discussed

Restructuring of supported Pd by green solvents: an operando Quick EXAFS (QEXAFS) study and implications for the derivation of structure-function relationships in Pd catalysis

Transmission electron microscopy (TEM) is commonly used as an ex-situ technique to determine structural changes by comparing images of catalyst particles before and after a reaction. This requires the use of an alcoholic solvent to disperse the particles on a grid. In this work, we will show that Pd catalysts can be transformed during the procedure, by using EXAFS to determine the structure of Pd catalysts in different environments (as dry or wet samples). Supported palladium nanoparticles exposed to aqueous ethanolic solution (50% w/v) are transformed to a common, reduced, and hydrogen-contaminated state, irrespective of their initial habit or support. Catalysts comprised of nanosize PdO are reduced at ca. 350 K, whereas samples comprised of very small (ca. ≤ 10 atoms) Pd particles react with the solvent at just above room temperature and agglomerating with considerable loss of dispersion. As such any potential benefits to catalysis sought through the synthesis of very highly dispersed metallic Pd supported upon a range of inorganic dispersants will be rapidly erased through the action of such solvents

Glucose enhancement of memory is modulated by trait anxiety in healthy adolescent males

Glucose administration is associated with memory enhancement in healthy young individuals under conditions of divided attention at encoding. While the specific neurocognitive mechanisms underlying this ‘glucose memory facilitation effect’ are currently uncertain, it is thought that individual differences in glucoregulatory efficiency may alter an individual’s sensitivity to the glucose memory facilitation effect. In the present study, we sought to investigate whether basal hypothalamic–pituitary–adrenal axis function (itself a modulator of glucoregulatory efficiency), baseline self-reported stress and trait anxiety influence the glucose memory facilitation effect. Adolescent males (age range = 14–17 years) were administered glucose and placebo prior to completing a verbal episodic memory task on two separate testing days in a counter-balanced, within-subjects design. Glucose ingestion improved verbal episodic memory performance when memory recall was tested (i) within an hour of glucose ingestion and encoding, and (ii) one week subsequent to glucose ingestion and encoding. Basal hypothalamic–pituitary–adrenal axis function did not appear to influence the glucose memory facilitation effect; however, glucose ingestion only improved memory in participants reporting relatively higher trait anxiety. These findings suggest that the glucose memory facilitation effect may be mediated by biological mechanisms associated with trait anxiety

'Homeopathic' palladium catalysis? The observation of distinct kinetic regimes in a ligandless Heck reaction at (ultra-)low catalyst loadings

The catalytic behaviour of ‘ligandless’ palladium(II) acetate in the Heck arylation reaction of iodobenzene with methyl acrylate is examined at (ultra-)low catalyst loadings using in situ spectroscopy. The study reveals two distinctive kinetic regimes with distinct Pd orders. A simplified microkinetic model revealed the presence of at least two kinetically competent catalysts, represented by a monomeric (Pd1) and dimeric (Pd2) species. The relative catalytic activity and deactivation rates for both species can also be estimated from the experimental results. This work provides direct kinetic evidence that a higher-order Pd species can be more active than a monomeric species, and the key role played by catalyst deactivation, particularly at higher catalyst loadings. This implies that lowering the catalyst loading may be an effective strategy to combat catalyst deactivation without necessarily incurring significant deterioration in reaction rate