Comment on "Theoretical design of molecular nanomagnets for magnetic refrigeration" [Appl. Phys. Lett. 103, 202410 (2013)]

Garlatti et al. [Appl. Phys. Lett. 103, 202410 (2013)] report theoretical simulations aimed at showing that the best molecular nanomagnets for magnetic refrigeration between T = 10 K and sub-Kelvin region are those made of strongly ferromagnetically-coupled magnetic ions. This Comment revises such conclusion based on results that, apparently, contrast with the established belief in this research field.Comment: 3 pages, 2 figure

Can we declare military Keynesianism dead?

This paper empirically tests the Keynesian hypothesis that government defence spending positively impacts on aggregate output, by using a long run equilibrium model for the US and the UK. Our contribution, with respect to previous works, is twofold. First, our inferences are adjusted for structural breaks exhibited by the data concerning fiscal and monetary variables. Second, we take into account different dynamics between defence spending on aggregate output, showing that the results are sensitive to sub-sample choices. Though the estimated elasticities in both countries show a lack of significance in the more recent years of the sample, defence spending priorities addressed to international security may revitalize pro-cyclical effects in the UK, by an industrial policy of defence shared with the EU members.Military spending, Output, Long run models

Nanotechnology, Aims, and Values

This paper seeks to understand the importance of adopting an ethical framework based on values in the socio-ethical discussion on nanotechnology and generally on emerging technologies. In particular, within such framework it is introduced a distinction between two ideal types of science, defined on the basis of their different aims. Such distinction is considered to be a useful guide in the ethical debate on the technological development of our society, because it may help to understand what are the values of science and their relations with our values as members of the social community. My point is that a reflection on the values of science is needed to make scientists aware of their responsibilities as scientists in the society. Once scientists have understood their responsibilities as scientists they could be involved in a broader ethical reflection on their responsibilities as citizens. Technological development makes sense only if intended as an evolution of socio-technical systems and it is not possible to make an ethical evaluation of such evolution without having established what are our values and our idea of a common good. For these reasons nanotechnology should deal with our values, our idea of a common good, and our being responsible as citizens

Mitos y realidades que se crearon entorno al culto de la Santa Muerte en México. Entrevista con la mismísima Muerte

L’articolo propone un approccio ameno al culto popolare della santa Morte così come si è sviluppato in Messico. Senza rinunciare al rigore scientifico della ricerca, si utilizza la finzione letteraria cercando di evidenziare gli elementi storici, sociali e culturali che l’hanno trasformata in un fenomeno molto rilevante per la sua presenza mediatica e la sua diffusione tra milioni di persone. Al di là delle cifre si cerca di tracciare una cornice generale che aiuti a distinguere tra i molti miti che si sono andati creando e le realtà che, per contro, sono rimaste in secondo piano.El artículo propone un acercamiento ameno al tema del culto popular a la santa Muerte en México. Sin renunciar al rigor científico de la investigación subyacente, se usa la ficción literaria, tratando de destacar los elementos históricos, sociales y culturales que la han transformado en un fenómeno muy relevante por su presencia mediática y su difusión entre millones de personas. Más allá de las cifras, es importante trazar un marco general para distinguir entre los muchos mitos que se han creado a su alrededor y las realidades que, en cambio, han quedado en segundo plano.This paper attempts to approach the traditional Mexican cult of the Holy Death in a somehow light fashion. It does not avoid scientific exactitude, but in the meantime it uses fiction as a means to highlight the historical, social and cultural elements that have made it an outstanding mediatic phenomenon, diffused among million of people. It does not stick merely on numeric data, but tries to sketch out a framework to make distinctions between the several myths that have been created and the actual facts that have been pushed to the background

SVILUPPO DI UN CATODO CAVO PER APPLICAZIONI SU MOTORI A EFFETTO HALL AD ALTA POTENZA

Il presente lavoro di tesi descrive l’attività di sperimentazione su un catodo cavo per un motore ad effetto Hall da 5kW e lo studio teorico-numerico del processo di scarica del suddetto catodo nella configurazione di prova. Trattandosi del primo prototipo di catodo per motori ad effetto Hall, interamente progettato al Centrospazio in un precedente lavoro di tesi, l’attività di prova del catodo è stata focalizzata sulle modalità di accensione secondo una procedura di attivazione tipica dei catodi cavi e sulla stabilità della scarica di plasma per alcuni regimi di portata di gas e di tensione anodica. Pertanto si è deciso di provare il catodo in semplice configurazione a diodo. Questo ha richiesto la progettazione di un supporto per il fissaggio sull’impianto di prova IV4, e per i collegamenti con il sistema di alimentazione elettrica e gassosa già in dotazione. I dati sperimentali hanno permesso di determinare la caratteristica elettrica del catodo e di evidenziare al momento dell’accensione una certa instabilità dell’arco tra catodo ed elettrodo mantenitore una volta spento il riscaldatore. Tuttavia con corrente tra catodo ed anodo esterno la scarica è risultata stabile e lo spegnimento del catodo si è reso necessario per non surriscaldare eccessivamente l’anodo. Infine la parte del lavoro di tesi relativa allo studio del modello fisico-matematico della regione di scarica tra catodo ed anodo, ha richiesto una trattazione del plasma come un continuo multi-fluido (elettroni, ioni monovalenti e neutri) fortemente ionizzato. I risultati numerici ottenuti hanno permesso di ricavare gli andamenti delle densità, temperatura, velocità e pressione per le tre specie componenti il plasma. Il buon accordo della caratteristica elettrica del modello con quella ottenuta sperimentalmente suggerisce una parziale validazione del modello stesso

Women of the POUM

Il contenuto di questo articulo è esttratto dal libro “Spagna ’36. Voci dal POUM”. Aracne Edizioni. Roma 2009, e tratta del ruolo assunto dalle donne del POUM durante la Guerra Civile Spagnola, come attiviste politiche e come femministe. Queste donne hanno vissuto la “doppia militanza” ed hanno lottato contro chi le voleva mogli, madri, prima che compagne e attiviste di partito visto che la differenza di genero, oggi, come allora, è trasversale alla classe e alla razza. Queste donne, la cui azione è stata poco riconosciuta dalla storia, furono militanti di un partito perseguito dagli stalinisti e dai fascisti, ed hanno vissuto la repressione, l’esilio, ed il ritorno in patria, così come le difficoltà di organizzare liberamente la loro vita. Furono le donne del POUM, così come le anarchiste e le antifasciste che lottarono durante la Guerra Civile Spagnola, le anticipatrici di una linea rivoluzionara e rivendicativa, che prosseguirà con più forza e convinzione negli anni Settenta a livello mondiale. L’attivismo politico di queste donne, come dimostrano le azioni di reclutamento nella sezione femminile del POUM a partire della creazione del Segretariato femminile del Partito, l’assistenza medica offerta dall’organizzazione “Socorro rojo”, i corsi di alfabetizzazione, la lotta contro la prostituzione, la lotta per l’uguaglianza dei diritti salariali, la creazione di asili nidi e mense popolari, i corsi di formazione, marcarono l’inizio della presa di coscienza dei propi diritti come rivoluzionarie e donne. L’articolo si conclude con le testimonianze di donne in esilio e donne rimpatriate dopo la morte del dittadore, che è stato possibile intervistare e conoscere personalmente, durante la ricerca che ha portato alla realizzazione di questo libro sulla memoria storica di giovani rivoluzionarie, che continuano ancora oggi la loro lotta personale per migliorare i diritti civili della società attuale.The content of this article is an extract of the book Spagna’36. Voci dal POUM. Aracne Edizione, Roma, and and emphasizes the role of played by the POUM women during the Spanish Civil War, either as political activists or as feminists. This is an article about women who have experienced the “double militancy” and have fought against those who wanted wives, mothers, rather than revolutionary and party activists due to the fact that the gender difference, today, as then, is transverse to class and race. These women, whose work has been largely unrecognized by history, were members of a party which was pursued by the Stalinists and ascists and, moreover, they experienced repression, exile and returning home, as well as the difficulties of organizing themselves their personal and political life. As it is read here, those who anticipate a revolutionary line which would continue in full force in the seventies worldwide were the women of the POUM and the anarchists and anti-fascists who fought during the Spanish civil war, the expectations of a revolutionary line and claims that it will continue in full force in the seventies worldwide. The political activism of these women, as evidenced by the actions of recruitment in the women’s section of the POUM from the creation of women’s Secretariat of the Party, the medical assistance offered by the organization “Socorro Rojo”, the literacy classes, the struggle against prostitution, the fight for equal salaries, the creation of popular nurseries and kitchens, training courses, marked the beginning of the awareness of the conscience about their own rights as revolutionary and women. The article concludes with witnesses of women in exile and women who returned after the death of the dictator, those who the writter has had the opportunity to interview and meet in person, at the rate of this book about historical memory

Do Prekindergarten Teachers Design Their Classrooms to Enhance Early Literacy?

Young children develop language and early literacy interactions that are the building blocks for future skilled reading. This study was designed to evaluate the early childhood classroom to determine teachers‟ knowledge of early literacy. Based on the Literacy Environment Checklist (LEC) of the Early Literacy and Language Classroom Observation (ELLCO) tool, the classrooms scored 100% proficiency in the Book Area and Book Selection categories. The results indicate the prekindergarten teachers knew how to design their classrooms to enhance early literacy. The classrooms scored 86% proficiency in the Writing Materials category, 73% proficiency in the Writing around the Room category, and 58% proficiency in the Book Use category. These results indicate that the teachers did not utilize early literacy materials or did not have necessary early literacy materials in the classrooms. Many of the teachers had minimal early literacy training. Without specific early literacy training, teachers did not design their classrooms in ways that would enhance early literacy

Finite Element Simulation Of The Offset-Deformable Barrier Euro NCAP Crash Test Reproduction On A HYGE Sled For Assessing Ten-Year-Old Child Safety

This research focuses on the definition of the guidelines to simulate a sled test which reproduces the ODB Euro NCAP crash test, using LS-DYNA Finite Element code. In addition, the last sections are based on the validation of the model, comparing numerical results with those of an experimental sled test performed with the same equipment in late 2018, and on a sensitivity study on the friction coefficient of a virtual slip ring. Several FE models have been utilized, to represent vehicle body, seats and restraint system with LS-DYNA. The subject of the test is a ten-year-old child dummy (Q-series Q10), placed on a booster seat in the second-row seat of the vehicle. Both experimental and numerical dummies were provided by Humanetics®. All the pre-processing steps needed to perform this kind of simulation have been described throughout this thesis. The most investigated step was the generation and calibration of the virtual restraint system, built utilising ANSA by BetaCAE. The LS-DYNA pretensioner and retractor were calibrated using different data from the experimental test as reference. The model was verified and validated computing cumulative error and validation metric. The head accelerations showed values of V equal to 78, 79 and 76% respectively, reasonably predicting the trend of the experimental curves. Additionally, the HICs have been well predicted, with coincident time instants and peak relative error below 15%. Chest and pelvis accelerations were predicted with an average V equal to 85%, constituting the areas of highest performance of the FE model. Upper neck forces and moments displayed an acceptable level of prediction, with V at least equal to 70%, whereas the lower neck showed the lowest correlation of the results, mostly on x and z-moments. It is important to underline that all biomechanical data in this thesis document were normalized for confidentiality reasons. Lastly, a sensitivity study on the influence of the dynamic friction coefficient FC of the lower LS-DYNA slip ring on the dummy injury responses was performed, obtaining a more correlated operation of the belt with respect to the experimental setting. The analysis was performed comparing all values of E and V among the different configurations, concluding that the most correlated setting has FC = 0.4, with an increase in V of 10% in the upper neck region