Fabrication of Insulation Coatings on Additively Manufactured CuCrZr Electrical Windings

To lower the ac losses in electrical machines, additive manufacturing (AM) has been adopted to exploit the geometrical freedom in winding design. However, AM brings about new challenges such as surface roughness and porosity which can create difficulties for post processing of the windings such as applying insulation coatings. The article investigates the influence of surface roughness (profile) of AM-processed CuCrZr as a potential candidate for electrical windings in terms of geometry, surface roughness, porosity, and oxidation on their insulation. The feasibility and characteristics of insulations applied via three processing techniques namely powder, spray, and dip coating are compared. The entire process is quantified via techniques such as computed tomography, surface profilometry, optical microscopy, X-ray photon spectroscopy, and breakdown voltage (BV) at different stages of the coating process. The study also includes coating on a commercial rectangular copper wire as a reference. The initial assessment of coatings concludes that surface roughness and the coating process are both vital determinants for the success of insulating AM components. Basic surface smoothening is needed to get rid of burs and the spray coating technique was the best among others for its capability to produce conformal coating

Phonon Density of States and Anharmonicity of UO2

Phonon density of states (PDOS) measurements have been performed on polycrystalline UO2 at 295 and 1200 K using time-of-flight inelastic neutron scattering to investigate the impact of anharmonicity on the vibrational spectra and to benchmark ab initio PDOS simulations performed on this strongly correlated Mott-insulator. Time-of-flight PDOS measurements include anharmonic linewidth broadening inherently and the factor of ~ 7 enhancement of the oxygen spectrum relative to the uranium component by the neutron weighting increases sensitivity to the oxygen-dominated optical phonon modes. The first-principles simulations of quasi-harmonic PDOS spectra were neutron-weighted and anharmonicity was introduced in an approximate way by convolution with wavevector-weighted averages over our previously measured phonon linewidths for UO2 that are provided in numerical form. Comparisons between the PDOS measurements and the simulations show reasonable agreement overall, but they also reveal important areas of disagreement for both high and low temperatures. The discrepancies stem largely from an ~ 10 meV compression in the overall bandwidth (energy range) of the oxygen-dominated optical phonons in the simulations. A similar linewidth-convoluted comparison performed with the PDOS spectrum of Dolling et al. obtained by shell-model fitting to their historical phonon dispersion measurements shows excellent agreement with the time-of-flight PDOS measurements reported here. In contrast, we show by comparisons of spectra in linewidth-convoluted form that recent first-principles simulations for UO2 fail to account for the PDOS spectrum determined from the measurements of Dolling et al. These results demonstrate PDOS measurements to be stringent tests for ab initio simulations of phonon physics in UO2 and they indicate further the need for advances in theory to address lattice dynamics of UO2.Comment: Text slightly modified, results unchange

Investment in Children, Social Security, and Intragenerational Risk Sharing

We analyze the role of pay-as-you-go social security in intragenerational risk sharing in an overlapping-generations model with individual heterogeneity. Parents invest in their children’s education in state schools in exchange for old-age financial support. Due to random factors such as luck in the job market, children may have different earning capacities despite that they receive the same education. Without social secu- rity, a parent gets a transfer payment from her own child, so the received amount is uncertain as it depends on the child’s earnings. The social security scheme, which essentially serves to pool transfer contributions from all children and then redis- tribute them equally to each parent, insures parents against the risk of educational investments. Our model shows that social security stimulates educational spending, enhances labor earnings, and increases ex ante individual utility. However, it may worsen ex post intragenerational inequality of lifetime income

Monitoring dynamics of single-cell gene expression over multiple cell cycles

Recent progress in reconstructing gene regulatory networks has established a framework for a quantitative description of the dynamics of many important cellular processes. Such a description will require novel experimental techniques that enable the generation of time-series data for the governing regulatory proteins in a large number of individual living cells. Here, we utilize microfabrication to construct a Tesla microchemostat that permits single-cell fluorescence imaging of gene expression over many cellular generations. The device is used to capture and constrain asymmetrically dividing or motile cells within a trapping region and to deliver nutrients and regulate the cellular population within this region. We illustrate the operation of the microchemostat with Saccharomyces cerevisiae and explore the evolution of single-cell gene expression and cycle time as a function of generation. Our findings highlight the importance of novel assays for quantifying the dynamics of gene expression and cellular growth, and establish a methodology for exploring the effects of gene expression on long-term processes such as cellular aging

Phenotypic impact of regulatory noise in cellular stress-response pathways

Recent studies indicate that intrinsic promoter-mediated gene expression noise can confer a selective advantage under acute environmental stress by providing beneficial phenotypic diversity within cell populations. To investigate how extrinsic gene expression noise impacts the fitness of cell populations under stress, we engineered two nearly isogenic budding yeast strains; one carrying a two-step regulatory cascade that allows for precise control of the noise transmitted from a transcriptional regulator to a downstream stress-inducing gene, and one carrying a network with low constant upstream noise. The fitness and gene expression of these strains were compared under acute and prolonged stress exposure. Using a phenomenological modeling approach, we predicted that increased noise should confer a fitness advantage under high stress conditions, but reciprocally reduce the resistance of the population to low stress. The model also predicted that extrinsic noise might serve as a basis for phenotypic plasticity whereby gene expression distributions are modulated in response to prolonged stress. Experimentally, we confirmed the predicted differential fitness advantage of extrinsic noise under acute stress, as well as the predicted modulation of gene expression under prolonged stress. However, contrary to model predictions, strains with low and high extrinsic noise showed very similar adaptive responses to prolonged stress. This suggests that while phenotypic heterogeneity generated by noise in regulatory signals can confer increased robustness to acute stress, it is not a requirement for the observed long-term phenotypic plasticity

EXPLAINING SUSTAINABILITY IN HEALTHCARE - A PRELIMINARY STUDY OF AN AGED CARE ORGANISATION IN AUSTRALIA

IT initiatives in healthcare often promise much but fail to deliver. As with IT projects in any other industry, healthcare projects may be abandoned before delivery, or if delivered, they may lack adoption or fail to deliver continuous use over a sustained period of time. Failure factors typically discussed in the IS literature fail to fully explain why sustainability is such an issue in the healthcare industry. Healthcare systems are technically complex to begin with. They involve a large number of stakeholders. Therefore their implementation process involves more planning and forethoughts. This paper focuses on the sustainability issues of healthcare information systems (HIS) implementation. We reviewed a broad array of literature to try to clarify the concept of sustainability within the defined context. We arrived at a broad framework for defining different types of sustainability for HIS. We propose they must all be considered for every sustainable healthcare IS implementation. Then using a successful aged care organisation in Australia, we explain the relevance of each type of sustainability defined. We conclude with some discussions of future work

Leveraging Rationales to Improve Human Task Performance

Machine learning (ML) systems across many application areas are increasingly demonstrating performance that is beyond that of humans. In response to the proliferation of such models, the field of Explainable AI (XAI) has sought to develop techniques that enhance the transparency and interpretability of machine learning methods. In this work, we consider a question not previously explored within the XAI and ML communities: Given a computational system whose performance exceeds that of its human user, can explainable AI capabilities be leveraged to improve the performance of the human? We study this question in the context of the game of Chess, for which computational game engines that surpass the performance of the average player are widely available. We introduce the Rationale-Generating Algorithm, an automated technique for generating rationales for utility-based computational methods, which we evaluate with a multi-day user study against two baselines. The results show that our approach produces rationales that lead to statistically significant improvement in human task performance, demonstrating that rationales automatically generated from an AI's internal task model can be used not only to explain what the system is doing, but also to instruct the user and ultimately improve their task performance.Comment: ACM IUI 202