Design and Techno‐Economic Analysis of a Process for Transforming Pig Manure into a Value‐Added Product

This study involves the design and techno‐economic analysis of a process that couples biodrying and conventional drying to increase the economic value of liquid pig manure sludge, by transforming it into a stable organic fertilizer. The process has significant environmental benefits compared to other disposal methods, especially considering recent legislative changes restricting the spreading of liquid pig manure, and at the same time provides a return on investment. It was found that the rate of return for the process was 14%, but could reach 25% if the price of the fertilizer product increases as expected.     

Temperature-sensitive production of rabbit muscle glycogen phosphorylase in Escherichia coli

In order to understand how allosteric switches regulate boththe catalytic activity and molecular interactions of glycogenphosphorylase, it is necessary to design and analyze variantproteins that test hypotheses about the structural details ofthe allosteric mechanism. Essential to such an investigationis the ability to obtain large amounts of variant proteins.We developed a system for obtaining milligram amounts (>20 mg/1) of rabbit muscle phosphorylase from bacteria. Phosphorylaseaggregates as inactive protein when a strong bacterial promoteris used under full inducing conditions and normal growth conditions.However, when the growth temperature of bacteria expressingphosphorylase is reduced to 22°C we obtain active musclephosphorylase. The degree to which the induced expression ofphosphorylase protein is temperature sensitive depends on thestrain of bacteria used. New assay and purification methodswere developed to allow rapid purification of engineered phosphorylaseproteins from bacterial cultures. The rabbit muscle phosphorylaseobtained from the bacterial expression system is enzymaticallyidentical to the enzyme purified from rabbit muscle. The expressedprotein crystallizes in the same conditions used for growingcrystals of protein from rabbit muscle and the crystal formis isomorphous. Rabbit muscle phosphorylase is one of the largestoligomeric mammalian enzymes successfully expressed in Escherichiacoli. Our results indicate that optimization of a combinationof growth and induction conditions will be important in theexpression of other heterologous proteins in bacteria.     

Enantioselective Hydrogenation Using Cinchona-Modified Pt/γ-Al2O3 Catalysts: Comparison of the Reaction of Ethyl Pyruvate and Buta-2,3-dione

The enantioselective hydrogenation of buta-2,3-dione to 3-hydroxy-buta-2-one and ethyl pyruvate to ethyl lactate are compared using cinchona-modified Pt/γ-Al₂O₃ catalysts. The reactions were carried out in a range of solvents and both reactants gave the same linear relationship between enantiomeric excess (e.e.) and the dielectric constant of the solvent. The e.e. for the 3-hydroxy-buta-2-one is lower than that for ethyl pyruvate. For both reactants there is an optimal concentration of the cinchona modifier but the optimal concentration required for the hydrogenation of buta-2,3-dione is approximately an order of magnitude higher than that required for the hydrogenation of ethyl pyruvate. The hydrogenation of buta-2,3-dione in acetic acid as solvent leads to a suppression in the e.e. with an enhancement in rate, whereas the reaction of ethyl pyruvate in acetic acid leads to an enhancement in e.e. The e.e. for 3-hydroxy-buta-2-one formation is independent of conversion in the initial period of the reaction which contrasts markedly with the observed initial induction period for ethyl lactate formation. The results are discussed in terms of the interaction of the reactants with the cinchona alkaloid adsorbed on the Pt surface.     

Interfacial properties of kevlar-49 fiber-reinforced thermoplastics

A single-filament pull-out test was used to study adhesion of Kevlar-49 fibers to thermoplastic polymers. The test involved pulling a partially embedded fiber out of a polymer film. Kevlar-49 fibers with three different surface treatments were used with five thermoplastic materials. The test resulted in the measurement of two properties, an interfacial bond strength and a frictional shear strength. The interfacial bond strength is an essential factor in determining the critical aspect ratio of discontinuous fibers in a composite. The frictional shear strength was found to correlate with the tensile strength of discontinuous fiber composites which fail by fiber pull-out. Scanning electron microscopy was used to examine the fiber pull-out specimens after testing. Observations of the fiber showed that the failure mode at the fiber–matrix interface was complex. The predominant failure mode was fracture at the interface (or in some weak boundary layer). In some cases, cohesive failure of the fiber surface was observed, with the result that strips of material were torn from the fiber surface.     

Realization of Large Electric Polarization and Strong Magnetoelectric Coupling in BiMn3Cr4O12

Magnetoelectric multiferroics have received much attention in the past decade due to their interesting physics and promising multifunctional performance. For practical applications, simultaneous large ferroelectric polarization and strong magnetoelectric coupling are preferred. However, these two properties have not been found to be compatible in the single‐phase multiferroic materials discovered as yet. Here, it is shown that superior multiferroic properties exist in the A‐site ordered perovskite BiMn₃Cr₄O₁₂ synthesized under high‐pressure and high‐temperature conditions. The compound experiences a ferroelectric phase transition ascribed to the 6s² lone‐pair effects of Bi³⁺ at around 135 K, and a long‐range antiferromagnetic order related to the Cr³⁺ spins around 125 K, leading to the presence of a type‐I multiferroic phase with huge electric polarization. On further cooling to 48 K, a type‐II multiferroic phase induced by the special spin structure composed of both Mn‐ and Cr‐sublattices emerges, accompanied by considerable magnetoelectric coupling. BiMn₃Cr₄O₁₂ thus provides a rare example of joint multiferroicity, where two different types of multiferroic phases develop subsequently so that both large polarization and significant magnetoelectric effect are achieved in a single‐phase multiferroic material.     

Creep ductility of 1CrMoV rotor steel

Abstract

The creep ductility of 1CrMoV steels at a given temperature is high at high stresses responsible for high strain rates and ductile rupture, and low at lower stresses responsible for low strain rates and constrained cavity growth at grain boundaries. The magnitudes of ductility in the high and low stress regimes and the time to, and strain rate at, the transition between the two is determined by the chemical composition and the adopted quality heat treatment procedure of the steel. The basis for a material pedigree function forming part of a creep ductility model for 1CrMoV rotor steel is presented. Low ductility 1CrMoV steels are expected to be extremely notch sensitive. While this appears to be true for medium to high strength heats of the alloy, it is not necessarily the case for lower strength heats. There is not a simple inverse relationship between creep ductility and creep strength. Increasingly, creep-fatigue lifetime predictions for high temperature 1CrMoV power plant components subjected to thermo-mechanical transients employ a creep ductility exhaustion methodology to determine the creep damage accumulated per cycle. A creep ductility model of the type developed in the paper is suitable for forming the basis of such an approach.     

Randomized phase II study of two schedules of topotecan in previously treated patients with ovarian cancer: a National Cancer Institute of Canada Clinical Trials Group study

PURPOSE: As topotecan is S-phase-specific, its efficacy is likely schedule-dependent. Therefore, a randomized study using a "pick the winner" design was undertaken to compare two schedules in patients with recurrent ovarian cancer. PATIENTS AND METHODS: Patients with recurrent epithelial ovarian cancer previously treated with no more than two separate regimens of chemotherapy, one of which had to be platinum-containing, were randomized to either topotecan 1.5 mg/m2 intravenously (i.v.) over 30 minutes daily for 5 days repeated every 21 days (arm A, the standard arm), or topotecan 1.75 mg/m2 as a 24-hour infusion once a week for 4 weeks repeated every 6 weeks (arm B, the experimental arm). RESULTS: Sixty-six patients were eligible and 63 were assessable for response. The response rate in arm A was 22.6% (95% confidence interval [CI], 9.6% to 41.2%), which was significantly superior to that in arm B, 3.1% (95% CI, 0.1% to 16%) (P = .026). The regimens were not equitoxic, with 94% of patients on arm A experiencing grade 3 or 4 granulocytopenia as opposed to 52% on arm B. CONCLUSION: The weekly 24 hour infusion of topotecan at 1.75 mg/m2 was ineffective in relapsed ovarian cancer. The daily-times-five schedule remains the schedule of choice. As the regimens were not equitoxic, one cannot differentiate between an ineffective schedule and an ineffective dose as the reason for the differing response rates. However, the degree of myelotoxicity that already occurs will preclude any substantially higher dosing with the weekly regimen.     

Measuring fire severity using UAV imagery in semi-arid central Queensland,Australia

Remote-sensing methods for fire severity mapping have traditionally relied on multispectral imagery captured by satellite platforms carrying passive sensors such as Landsat Thematic Mapper /Enhanced Thematic Mapper Plus or Moderate Resolution Imaging Spectroradiometer. This article describes the analysis of high spatial resolution Unmanned Aerial Vehicle (UAV) imagery to assess fire severity on a 117 ha experimental fire conducted on coal mine rehabilitation in an open woodland environment in semi-arid Central Queensland, Australia. Three band indices, Excess Green Index, Excess Green Index Ratio, and Modified Excess Green Index, were used to derive differenced (d) fire severity maps from UAV data. Fire severity data sets derived from aerial photograph interpretation were used to assess the utility of employing UAV technology to determine fire severity impacts. The dEGI was able to separate high severity, low severity, and unburnt areas with an overall classification accuracy of 58% and Kappa statistic of 0.37; outperforming the dEGIR (overall accuracy 55%, Kappa 0.31) and the dMEGI (overall accuracy 38%, Kappa 0.06). Classification accuracy increased for all indices when canopy shadows were masked, with dEGI improving to an overall accuracy of 68% and 0.48 Kappa. The McNemar’s test indicated that there was no significant difference between the classification accuracies for dEGI and dEGIR (p < 0.05). The test also demonstrated that dMEGI was significantly lower in accuracy compared to dEGI and dEGIR (p < 0.05). We quantified the proportion of burnt area within each severity class and calculated that 32% of the site was burnt at high severity, 34% was burnt at low severity, and 34% of the block was unburnt due to the patchy nature of the fire. We discuss the UAV-specific errors associated with fire severity mapping, and the potential for UAVs to assist land managers to assess the extent and severity of fire and subsequent recovery of burnt ecosystems at local scales (10⁴m²–1 km²).     

Epipolar geometry estimation based on evolutionary agents

This paper presents a novel approach based on the use of evolutionary agents for epipolar geometry estimation. In contrast to conventional nonlinear optimization methods, the proposed technique employs each agent to denote a minimal subset to compute the fundamental matrix, and considers the data set of correspondences as a 1D cellular environment, in which the agents inhabit and evolve. The agents execute some evolutionary behavior, and evolve autonomously in a vast solution space to reach the optimal (or near optima) result. Then three different techniques are proposed in order to improve the searching ability and computational efficiency of the original agents. Subset template enables agents to collaborate more efficiently with each other, and inherit accurate information from the whole agent set. Competitive evolutionary agent (CEA) and finite multiple evolutionary agent (FMEA) apply a better evolutionary strategy or decision rule, and focus on different aspects of the evolutionary process. Experimental results with both synthetic data and real images show that the proposed agent-based approaches perform better than other typical methods in terms of accuracy and speed, and are more robust to noise and outliers.     

An Expert System for measuring shear-wave splitting above small earthquakes

As part of the development of a system for routinely measuring shear-wave splitting, this paper introduces an Expert System (ES) to measure the polarisations and time-delays of seismic shear-wave splitting in three-component seismograms above small earthquakes. Expert Systems are rule-based computer techniques designed to provide expertise in particular topics, where the rules are algorithms developed from previous knowledge and experience. The technique is tested on data recorded by the seismic network in Iceland. The statistics suggests that the ES is reasonably successful and provides appropriate initial input parameters for a more precise analysis, which leads to the success of the comprehensive Shear-Wave Analysis System (SWAS) for measuring shear-wave splitting.