Influence of the hydrostatic and the deviatoric components of stress on ductility of metals

Failure of ductile metals occurring as microvoids growth is known to strongly depend on the stress triaxiality parameter which is a conventional measure of the first stress invariant normalized with respect to the equivalent von Mises stress, which in turn is a conventional measure of the second stress invariant. The triaxiality parameter is usually assumed to not influence the stress-strain behavior of metals according to the von Mises plasticity. The effects of the Lode angle and of the stress triaxiality are investigated here with regard to ductile failure and to the stress-strain behavior. Experimental results and numerical predictions are compared for different metals and different specimen geometries, by investigating about various failure criteria and a procedure for the post-necking stress-strain characterization. Tensile specimens and notched plates are loaded up to failure, then finite elements simulations are verified by comparison with experimental data. The verified numerical data are then used to calculate local variables within the volume of failing specimens; the knowledge of these local variables enables to predict global and local failure conditions according to the selected failure models

Scuola Nuova e democrazia in Italia e in Europa

L'article reconstrueix les característiques i la naturalesa de la relació entre les pràctiques innovadores de l'avantguarda educativa de l'ensenyament actiu, els processos de democratització i el moviment de les Escoles Noves en el marc del procés de la renovació de la cultura educativa italiana i europea a principis del segle xx. Aquest àmbit d'investigació, encara poc desenvolupat a Itàlia, revisa el conjunt de connexions que lliguen la renovació educativa italiana amb els processos d'expansió democràticade la instrucció, amb els horitzons de progrés de la nova pedagogia experimental i amb l'evolució del paper de l'educació, entesa com una important força motriu per al desenvolupament social, civil i econòmic de la societat. És una època amb nombroses i significatives pràctiques educatives i pedagògiques que promouen els processos de transformació i la reforma de l'escola, que maduren, en un sentit democràtic, associats al treball social i filantròpic per a la protecció dels drets de l'infant, el procés d'alfabetització i l'educació popular. En aquest context sorgeixen els fonaments per a una nova relació entre Escola Nova i democràcia, tot i que patirà un fort retrocés amb la progressiva consolidació del règim feixista.The article reconstructs the characteristics and nature of the relationship between innovative practices of the educational forefront of active teaching, the processes of democratisation and the movement of the New School in the framework of the process of renewal of Italian and European educational culture in the early 20th century. This area of research, poorly developed in Italy, revises the set of connections linking the Italian educational renewal with the processes of democratic expansion of the instruction, the horizons of progress that the incipient experimental pedagogy proposes and the changing role of education recognised as a driving force for social, civil and economic development of society. This is a period with numerous and significant educational and pedagogical practices that promote the processes of transformation and school reform, which mature in a democratic sense, associated with social and philanthropic work for the protection of children’s rights, the literacy process and popular education. In such a context, the basis for a new relationship between New School and democracy arise, which will suffer a serious setback with the progressive consolidation of the fascist regime.El artículo reconstruye las características y naturaleza de la relación entre las prácticas innovadoras de la vanguardia educativa de la enseñanza activa, los procesos de democratización y el movimiento de la Escuela Nueva en el marco del proceso de la renovación de la cultura educativa italiana y europea a principios del siglo xx. Este ámbito de investigación, todavía poco desarrollado en Italia, revisa el conjunto de conexiones que vinculan la renovación educativa italiana con los procesos de expansión democrática de la instrucción, los horizontes de progreso que la incipiente pedagogía experimental propone y la evolución del papel de la educación reconocida como una fuerza motriz para el desarrollo social, civil y económico de la sociedad. Es una época con numerosas y significativas prácticas educativas y pedagógicas que promueven los procesos de transformación y de reforma de la escuela, que maduran en un sentido democrático, asociados al trabajo social y filantrópico para la protección de los derechos del niño, el proceso de alfabetización y la educación popular. En dicho contexto, surgen las bases para una nueva relación entre Escuela Nueva y democracia que sufrirá un fuerte retroceso con la progresiva consolidación del régimen fascista

Characteristics And Temporal Variations Of Organic And Elemental Carbon Aerosols In A High–Altitude, Tropical Latin American Megacity

Bogota is a Latin American megacity located at an average altitude of 2600 m in the tropical Andes. It registers frequent episodes of poor air quality due to high PM10 concentrations. The carbonaceous fraction is the main PM10 component (>50%), but there is a lack of specific studies analyzing the characteristics and temporal variability of organic carbon (OC) and elemental carbon (EC) aerosols. In this study, daily samples (24±1h) were collected from June 2015 to May 2016 (a total of 308 samples) at an urban background site during an El Niño year, and the quartz filters were analyzed using a thermal-optical method. Results showed that EC and organic matter accounted for ~60% of the PM10 mass. The OC and EC averages were 8.92 ± 4.52 μg/m3 and 3.25 ± 1.59 μg/m3, respectively. The months with the highest average OC values were January to March, while EC concentrations were relatively constant throughout the year. Regarding daily values, the highest mean concentrations of OC (10.2 ± 5.13 μg/m3) and EC (3.73 ± 1.74 μg/m3) were obtained on Thursdays, and the lowest on Sundays (OC = 6.67 ± 3.04 μg/m3 and EC = 2.46 ± 0.94 μg/m3). The OC/EC ratio ranged from 1.66 (June) to 4.88 (March), with an annual average of 3.16 ± 2.01. The secondary organic carbon (SOC) contributions, measured using the EC-tracer method, accounted for 45% of the total OC. The effective carbon ratio, which indicates an association between carbonaceous particles and climate change, ranged from 0.12 (July) to 0.74 (May). The study of air-mass origins revealed that days with air mass from E + NE registered the highest OC concentrations. This research provides new data on the variability of carbonaceous aerosols over the course of a year. It also highlights forest fires as a significant source of OC and EC, and indicates the high impact of SOC on OC concentration at the sampling site

Power Quality Monitoring Integration into Distribution Automation through the Use of AMR

Power-quality events are of increasing concern for the economy because today’s equipment, particularly computers and automated manufacturing devices, is highly sensitive to such imperfections. With volatile energy rates and a need to control costs, regional agencies and utilities are interested in technologies to meter distribution use and manage utility information. Metering technologies and communications systems have advanced to enable the development of Automated Meter Reading (AMR) Systems. Power Quality is one area where the AMR system can be very valuable. This paper investigates the challenges in the development of distributed power-quality monitoring system. The approach of this paper is divided into metering, data collection, archiving, analysis, and presentation. It also discusses system architecture, implementation, and provides general guidelines in the tailoring of PQ indexes. This paper describes the challenges and lessons learned from this work.

Consumptive hypothyroidism in a patient with malignant rhabdoid tumor of the kidney: case report on a newly found association

Introduction: Consumptive hypothyroidism is a rare paraneoplastic condition most commonly associated with infantile hemangiomas. It is caused by overexpression of deiodinase type 3 (D3), which leads to preferential conversion of thyroxine to the metabolically inactive reverse triiodothyronine (rT3), paralleled by a decrease of the biologically active T3. Case presentation: A 46-year-old male patient with previously normal thyroid function was diagnosed with a renal carcinoma with rhabdoid differentiation. He was treated with sunitinib, followed by the immune checkpoint inhibitors ipilimumab and nivolumab, and he developed primary hypothyroidism secondary to thyroiditis. Substitution with unusually high doses of levothyroxine as high as 4.3 mu g/kg/day did not normalize his thyroid function. Poor compliance was refuted because there was no improvement after observed administration. He had no malabsorption. Although tyrosine kinase inhibitors can increase the expression of D3, this effect tends to be modest. Therefore, the suspicion of tumor-related consumptive hypothyroidism was raised and supported by low free T3 and elevated rT3 levels. The therapy could not be further modified because the patient opted for palliative care and passed away 12 days later.Immunohistochemistry of the tumor from a sample obtained prior to systemic therapy documented abundant expression of D3, corroborating the diagnosis of consumptive hypothyroidism. Conclusions: This observation extends the spectrum of malignancies overexpressing D3. Although rare, increased awareness of this paraneoplastic syndrome is key, if persistent hypothyroidism cannot be explained by compliance issues or malabsorption. Substitution with high doses of levothyroxine, and combination therapy with liothyronine, can correct hypothyroidism in these patients

Cancer mortality trends in the Umbria region of Italy 1978–2004: a joinpoint regression analysis

BACKGROUND: The aim of the present paper was to analyse cancer mortality in the Umbria region, from 1978 to 2004. Mortality trends depend on a number of factors including exposures, health system interventions, and possibly artefact (e.g. classification change, variations of data completeness). Descriptive data on mortality only allow for generation of hypotheses to explain observed trends. Some clues on the respective role of possible mortality determinants may be found comparing mortality with incidence and survival data. METHODS: Mortality data for the periods 1978–1993 and 1994–2004 were supplied by the National Institute of Statistics (ISTAT) and the Regional Causes of Death Registry (ReNCaM) respectively. Sex and site-specific mortality time trends were analysed by the "joinpoint regression" method. RESULTS: For all sites combined, in both sexes, the standardised rate was first increasing before the end of the eighties and decreasing thereafter. Gastric cancer mortality showed a different trend by gender; that is the rate constantly decreased over the period among females while, for males, it was first increasing up to 1985 and decreasing thereafter. Liver cancer trend showed a pattern similar to gastric cancer. Large bowel cancer showed a gender specific trend, that is it was increasing among males and stable among females. Also lung cancer mortality varied by gender: it started to decline after 1989 among males but was steadily increasing over the study period among women. A decreasing trend for female breast cancer mortality began in 1994. Prostate cancer mortality trend is the only one showing two significant joinpoints: mortality decreased up to 1990, then it increased up to 1998 and, finally, was decreasing. CONCLUSION: Overall cancer mortality was decreasing in both sexes in Umbria and this favourable trend will probably continue and further improve since population screening against breast, cervix, and large bowel cancers were recently introduced. Besides gastric cancer, tobacco-related cancers and prostate cancer mainly contributed to mortality reduction in males, whereas breast cancer mainly contributed to declining mortality in females