28 resultados para Perovskite Type Mixed Oxides

em Deakin Research Online - Australia


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Oxygen production by air separation is of great importance in both environmental and industrial processes as most large scale clean energy technologies require oxygen as feed gas. Currently the conventional cryogenic air separation unit is a major economic impediment to the deployment of these clean energy technologies with carbon capture (i.e. oxy-fuel combustion ). Dense ceramic perovskite membranes are envisaged to replace the cryogenics and reduce O2 production costs by 35% or more; which can significantly cut the energy penalty by 50% when integrated in oxy-fuel power plant for CO2 capture. This paper reviews the current progress in the development of dense ceramic membranes for oxygen production. The principles, advantages or disadvantages, and the crucial problems of all kinds of membranes are discussed. Materials development, optimisation guidelines and suggestions for future research direction are also included. Some areas already previously reviewed are treated with less attention.

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Perovskite-type oxide LaCoO3 nanofibers have been fabricated by electrospinning and subsequent calcination technology. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction were used to characterize the morphology and structure. Rhodamine B (RhB) was used to evaluate the ultraviolet photocatalytic activity of the as-prepared nanofibers. The effect of calcination temperature and pH of the reaction solution on the decolorization of RhB were investigated. Results showed that the samples calcined at 600°C exhibited the best photocatalytic activity at pH 4. Additionally, the recycling experiments confirmed the attractive stability of the catalysts.

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Perovskite praseodymium ferrite (PrFeO3) porous nanotubes are prepared by electrospinning of the precursor solution into nanofibers, subsequently by annealing the precursor fibers at a low temperature (e.g. 40 °C) and finally by calcination at a high temperature. The low temperature annealing treatment is found to play a key role in the formation of porous nanotube. The porous tubes show a perovskite-type PrFeO3 crystal characteristic with high optical absorption in the UV-visible region and an energy band gap of 1.97 eV. When compared with PrFeO3 porous nanofibers and PrFeO3 particles, the PrFeO3 porous nanotubes show better visible-light photo-catalytic ability to degrade Rhodamine B in aqueous phase because of the increased surface area and more active catalytic sites on the inner walls and outer surfaces.

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The current study examines sexual and violent reoffence rates for a sample of 2474 sexual offenders over an average of 15 years following release from prison. Reoffence rates are reported as a function of the offenders' victim type and level of risk as assessed by the Automated Sexual Recidivism Scale, a computer scored measure of relevant historical risk factors. Observed sexual recidivism rates for offenders with child victims, adult victims, and mixed victims were quite similar. Results indicate that offenders with exclusively female child victims not only showed a lower rate of sexual reoffending, but that the reoffence rates were relatively low across all levels of actuarial risk. In contrast, those with male child victims and adult victims showed a pronounced escalation of reoffence rates as actuarial risk increased. Results also indicated that adult victim offenders are less consistent in the victim type of their reoffences, with 37% sexually reoffending against child victims. Finally, combined rates of sexual and violent reoffending were particularly high for those with adult victim sexual offence histories. Risk assessment and public policy implications are discussed.

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1706 files in 35 folders, containing 388MB. Comprises plots, figures, and manuscripts. The data contains x-ray diffraction patterns and electrochemical data of lanthanum based perovskite oxides (e.g. 9 different perovskite compositions e.g. LaNiO3, LaCoO3, LaFeO3, LaMnO3, LaCrO3, LaNi0.5Co0.5O3 and LaNi0.5Fe0.5O3, LaNi0.5Mn0.5O3 and LaNi0.5Cr0.5O3) characterized using rotating ring disk electrodes.

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In this work, LaMO3 and LaNi0.5M0.5O3 (M = Ni, Co, Fe, Mn and Cr) perovskite oxide electrocatalysts were synthesized by a combined ethylenediaminetetraacetic acid-citrate complexation technique and subsequent calcinations at 1000 °C in air. Their powder X-ray diffraction patterns demonstrate the formation of a specific crystalline structure for each composition. The catalytic property of these materials toward the oxygen reduction reaction (ORR) was studied in alkaline potassium hydroxide solution using the rotating disk and rotating ring-disk electrode techniques. Carbon is considered to be a crucial additive component because its addition into perovskite oxide leads to optimized ORR current density. For LaMO3 (M = Ni, Co, Fe, Mn and Cr)), in terms of the ORR current densities, the performance is enhanced in the order of LaCrO3, LaFeO3, LaNiO3, LaMnO3, and LaCoO3. For LaNi0.5M0.5O3, the ORR current performance is enhanced in the order of LaNi0.5Fe0.5O3, LaNi0.5Co0.5O3, LaNi0.5Cr0.5O3, and LaNi0.5Mn0.5O3. Overall, LaCoO3 demonstrates the best performance. Most notably, substituting half of the nickel with cobalt, iron, manganese, or chromium translates the ORR to a more positive onset potential, suggesting the beneficial catalytic effect of two transition metal cations with Mn as the most promising candidate. Koutecky–Levich analysis on the ORR current densities of all compositions indicates that the four-electron pathway is favored on these oxides, which are consistent with hydroperoxide ion formation of <2%.

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Health analysis often involves prediction of multiple outcomes of mixed-type. Existing work is restrictive to either a limited number or specific outcome types. We propose a framework for mixed-type multi-outcome prediction. Our proposed framework proposes a cumulative loss function composed of a specific loss function for each outcome type - as an example, least square (continuous outcome), hinge (binary outcome), poisson (count outcome) and exponential (non-negative outcome). Tomodel these outcomes jointly, we impose a commonality across the prediction parameters through a common matrix-Normal prior. The framework is formulated as iterative optimization problems and solved using an efficient Block coordinate descent method (BCD). We empirically demonstrate both scalability and convergence. We apply the proposed model to a synthetic dataset and then on two real-world cohorts: a Cancer cohort and an Acute Myocardial Infarction cohort collected over a two year period. We predict multiple emergency related outcomes - as example, future emergency presentations (binary), emergency admissions (count), emergency length-of-stay-days (non-negative) and emergency time-to-next-admission-day (non-negative). Weshow that the predictive performance of the proposed model is better than several state-of-the-art baselines.

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The reaction of Me3SiCH2Cl2Sn(CH2)3SnCl2Ph (6) with (tBu2SnO)3 gave a statistical mixture of the corresponding tetraorganodistannoxanes whereas the reaction of the spacer-bridged ditin tetrachlorides RCl2Sn(CH2)4SnCl2R (3, R = Me3CCH2; 4, R = Me2CHCH2; 10, R = Me3SiCH2) with the polymeric spacer-bridged ditin oxides [R(O)Sn(CH2)4Sn(O)R]n (7, R = Me2CHCH2; 8, R = Me3CCH2; 11, R = Me3SiCH2) provided the mixed double ladder compounds {[R(Cl)Sn(CH2)4Sn(Cl)R][R(Cl)Sn(CH2)4Sn(Cl)R']O2}2 (9, R = Me3CCH2, R' = Me2CHCH2; 12, R = Me3CCH2, R' = Me3SiCH2) in almost quantitative yield. In solution, 9 and 12 are in equilibrium with their corresponding dimers, as was evidenced by 119Sn NMR spectroscopy, molecular mass determination, and electrospray mass spectrometry. The molecular structures of 9 and 12 were established by single crystal X-ray diffraction.

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This paper is based on ongoing work in developing interactive interfaces to formal methods for encoding design knowledge. It reports on the development of a shared graphical notation to support user interaction with design knowledge based on mixed-initiative. Mixed-initiative provides a model of interaction where both the designer and the knowledge formalism may share responsibility over decisions. The paper discusses how a formal visual notation can support the mixed-initiative mode for developing and managing formal design knowledge. The notation addresses on the dialogue problem between the user and a knowledge based formalism and illustrates a model of interaction in which the user and the formalism can share and input data through a common shared resource, on a common shared task. The paper demonstrates the use of this notation in common decision tasks and the implications for seamless interaction with design support systems.
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The stimulatory effect of vasomodulatory natriuretic peptide hormones on macrophages and peripheral blood leucocytes in mammals is well-established. However, the relationship in lower vertebrates has not been characterised. Expression of atrial natriuretic peptide, ventricular natriuretic peptide and C-type natriuretic peptide-1, and the guanylyl cyclase-linked (GC) natriuretic peptide receptor-A and -B-type receptors (NPR-A and NPR-B, respectively) was determined by PCR from the mRNA of rainbow trout head kidney leucocytes yielding gene fragments with 100% homology to the same respective natriuretic peptide and NPR-A and -B sequences obtained from other rainbow trout tissues. A mixed population of isolated rainbow trout head kidney leucocytes was stimulated in vitro with trout atrial natriuretic peptide (specific NPR-A agonist) and trout C-type natriuretic peptide (NPR-A and -B agonist) as well as the cGMP agonist 8-bromo-cGMP or the GC inhibitor 8-bromo-phenyl-eutheno-cGMP. Respiratory burst was stimulated by trout atrial natriuretic peptide, trout C-type natriuretic peptide-1 and 8-bromo-cGMP in a dose dependant manner with the highest activity as a result of stimulation with trout C-type natriuretic peptide-1 in excess of that achieved by phorbol myristate acetate (PMA). Equimolar concentrations of the inhibitor, inhibited the respiratory burst caused by the natriuretic peptides and 8-bromo-cGMP. The natriuretic peptide receptors on rainbow trout head kidney leucocytes appear to have a stimulatory function with regard to respiratory burst that is activated through a cGMP second messenger pathway and the natriuretic peptides expressed in the head kidney leucocytes may well act in a paracrine/autocrine manner.

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The thesis examined early differences between girls and boys in their attitudes and social behaviour which might help explain why girls and women continue to reject computing. The behaviour of preschool children playing freely for three supervised sessions in either same-gender or mixed-gender pairs with a computerised robot was studied, and then their individual programming performance was measured. Conclusions were that social interaction and computer programming performance were not differentiated by gender. Mixed-gender pairs had a significant effect on both children's style of social interaction and their performance, an impact that was particularly negative for girls.

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Modeling helps to understand and predict the outcome of complex systems. Inductive modeling methodologies are beneficial for modeling the systems where the uncertainties involved in the system do not permit to obtain an accurate physical model. However inductive models, like artificial neural networks (ANNs), may suffer from a few drawbacks involving over-fitting and the difficulty to easily understand the model itself. This can result in user reluctance to accept the model or even complete rejection of the modeling results. Thus, it becomes highly desirable to make such inductive models more comprehensible and to automatically determine the model complexity to avoid over-fitting. In this paper, we propose a novel type of ANN, a mixed transfer function artificial neural network (MTFANN), which aims to improve the complexity fitting and comprehensibility of the most popular type of ANN (MLP - a Multilayer Perceptron).

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Objectives: Subthreshold mixed states are common, yet their clinical significance is unclear. This study investigated the clinical outcomes of subthreshold mixed states in participants with bipolarI disorder or schizoaffective disorder, using the Cassidy and Benazzi criteria for manic and depressive mixed states, respectively.

Methods: The Bipolar Comprehensive Outcomes Study (BCOS) is a prospective observational study of treatment and outcomes for patients with bipolar I or schizoaffective disorder, bipolar type. Participants (N=239) were grouped based on study entry clinical presentation as having pure depression (n=63) if they satisfied DSM-IV-TR criteria for a Major Depressive Episode (MDE), depressive mixed state (DMX) if they also had at least three concurrent hypomanic symptoms (n=33), or not depressed (n=143) if they did not satisfy the criteria for MDE. Participants were similarly grouped as having pure mania (n=3) if they satisfied DSM-IV criteria for a Manic Episode, manic mixed state (MMX) if they also had at least two concurrent depressive symptoms (n=33), or not manic (n=203). Clinical data were collected by interview every 3-months over a 24-month period.

Results: Measures of quality of life, mental and physical health over the 24-month period were significantly worse for participants who were classified as having mixed states at study entry on most outcome measures compared to participants who were not in an illness episode at study entry. DMX was predictive of greater manic symptomatology over the 24 months compared to participants with pure depression.

Conclusion: In participants with a current episode of mood disorder, the presence of subthreshold symptoms of opposite polarity was associated with poorer clinical outcomes over a 24-month period.

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Aims For selected individuals with complex Type 1 diabetes, pancreatic islet transplantation (IT) offers the potential of excellent glycaemic controlwithout significant hypoglycaemia, balanced by the need for ongoing systemic immunosuppression. Increasingly, patient-reported outcomes (PROs) are considered alongside biomedical outcomes as a measure of transplant success. PROs in IT have not previously been compared directlywith the closest alternate treatment option, pancreas transplant alone (PTA) or pancreas after kidney (PAK).

Methods We used a Population, Intervention, Comparisons, Outcomes (PICO) strategy to search Scopus and screened 314 references for inclusion.

Results Twelve studies [including PRO assessment of PAK, PTA, islet-after kidney (IAK) and islet transplant alone (ITA); n = 7–205] used a total of nine specified and two unspecified PRO measures. Results were mixed but identified some benefits which remained apparent up to 36 months post-transplant, including improvements in fear of hypoglycaemia, as well as some aspects of diabetes-specific quality of life (QoL) and general health status. Negative outcomes included short-term pain associated with the procedure, immunosuppressant side effects and depressed mood associated with loss of graft function.

Conclusions The mixed resultsmay be attributable to limited sample sizes. Also, some PROmeasures may lack sensitivity to detect actual changes, as they exclude issues and domains of life likely to be important forQoL post-transplantation and when patients may no longer perceive themselves to have diabetes. Thus, the full impact of islet ⁄ pancreas transplantation (alone or after kidney) on QoL is unknown. Furthermore, no studies have assessed patient satisfaction, which may highlight further advantages and disadvantages of transplantation.