Thermal Treatments of AlSi10Mg Processed by Laser Beam Melting

Recent studies have shown that AlSi10Mg processed by Laser Beam Melting (LBM) exhibits a much finer microstructure when compared to its cast counterpart as a consequence of the much faster cooling rates imposed in the LBM process. Such microstructural refinement causes a significant increase in strength and hardness, to such an extent that as-fabricated LBM AlSi10Mg was reported to present hardness value of 127 ± 3 Hv0.5, similar to the hardness of high pressure die cast AlSi10Mg in the aged condition (i.e. 130-133 Hv). Yet, little attention has been given so far to the influence of thermal treatments on the microstructure and mechanical behavior of LBM AlSi10Mg. The present work hence aims to investigate the effect of two different types of heat treatments – i.e. (i) stress relief and (ii) solutionizing and ageing − on the microstructure, hardness and tensile properties of LBM AlSi10Mg.Mechanical Engineerin

Social Security and Economic Integration

peer reviewe

Health spending, education and endogenous demographics in an OLG model

We present a model of endogenous aging with public expenditure on health and pensions financed by an income tax. We show that government policies on health and pensions might lift an economy from a low to a high income steady state. In particular, the impact of an increase in the income tax is non monotonic and depends on the initial levels of income and longevity: it is positive at low levels, and negative at high levels. On the other hand, a change in the allocation of public spending from social security benefits to health expenditures, without varying the tax rate, always increases income, even though pension benefits might decrease, and the problem of population aging could worsen

Voice outcome indicators for unilateral vocal fold paralysis surgery: a review of the literature

There is no consensus on which voice outcome indicators (VOIs) should be used to compare the merits of the various surgical treatments for unilateral vocal fold paralysis (UVFP). Authors performed a literature review to identify which VOIs are most frequently used and most relevant, in terms of significant change in pre- and post-operative measurements, to assess UVFP surgical treatments.A Medline/Pubmed literature review was performed and the most frequently used VOIs were identified using a Pareto diagram. For these most frequently used VOI's, the number of studies that showed a statistically significant change in pre- and post-operative results were compared to the total number of studies found using that same VOI, this portion was expressed in percent. This percentage was defined as the "percentage of significance" and used to assess changes of each VOI.Eleven VOIs were identified using the Pareto analysis. These were, in decreasing order of frequency of citation: maximum phonation time (MPT), jitter, Shimmer, video-stroboscopic examination, noise to harmonic ratio (NHR/HNR), mean air flow (MeAF), fundamental frequency (F0), "Infrequent Perceptional Scales", GRBAS scale, mean subglottic pressure (MSGP). MPT, MeAF, factor G of GRBAS-I, Jitter, shimmer and VHI-30 had respective "percentage of significance" of 90, 86, 85, 74, 68 and 64%, respectively.The results indicate that MPT, MeAF and GRBAS-I, represent the top-three most frequently used and the most relevant VOIs in terms of "percentage of significance". VHI-30 showed a relatively low rate of use and low "percentage of significance". The role of Jitter and Shimmer remains unclear. Finally, MSGP and the F0 appear to be less relevant VOIs for the evaluation of UFVP surgical treatments in terms of significant change in pre- and post-operative measurements