You and the Time

A medic reflects on how things have changed in his life over time. Articles, stories, and other compositions in this archive were written by participants in the Mighty Pen Project. The program, developed by author David L. Robbins, and in partnership with Virginia Commonwealth University and the Virginia War Memorial in Richmond, Virginia, offers veterans and their family members a customized twelve-week writing class, free of charge. The program encourages, supports, and assists participants in sharing their stories and experiences of military experience so both writer and audience may benefit

Superconducting nanowire quantum interference device based on Nb ultrathin films deposited on self-assembled porous Si templates

Magnetoresistance oscillations were observed on networks of superconducting ultrathin Nb nanowires presenting evidences of either thermal or quantum activated phase slips. The magnetic transport data, discussed in the framework of different scenarios, reveal that the system behaves coherently in the temperature range where the contribution of the fluctuations is important.Comment: accepted for publication on Nanotechnolog

Digital Methods to Study (and Reduce) the Impact of Disinformation

Social media have democratized communication but have led to the explosion of the so-called "fake news" phenomenon. This problem has visible implications on global security, both political (e.g.the QANON case) and health ( anti-Covid vaccination and No-Vax fake news). Models that detect the problem in real time and on large amounts of data are needed. Digital methods and text classification procedures are able to do this through predictive approaches to identify a suspect message or author. This paper aims to apply a supervised model to the study of fake news on the Twittersphere to highlight its potential and preliminary limitations. The case study is the infodemic generated on social media during the first phase of the COVID-19 emergency. The application of the supervised model involved the use of a training and testing dataset. The different preliminary steps to build the training dataset are also shown, highlighting, with a critical approach, the challenges of working with supervised algorithms. Two aspects emerge. The first is that it is important to block the sources of bad information, before the information itself. The second is that algorithms could be sources of bias. Social media companies need to be very careful about relying on automated classificatio

Aportació de les tècniques ATD/TG i espectroscòpia FT-IR a l’estudi de la carbonatació de la matriu cimentera

La microestructura del cemento portland durante la etapa de endurecimiento (fraguado) evoluciona debido a las reacciones de hidratación que ocurren entre el agua y el cemento. A partir de la caracterización y desarrollo de la microestructura se pueden conocer las propiedades de la mezcla, relacionando la microestructura con la macroestructura. Cuando el CO2 atmosférico penetra en los poros de una pasta de cemento portland o de un hormigón modifica el equilibrio químico de la solución de poros y de los hidratos. Esto conduce a la precipitación de CaCO3 , ocasionando la densificación de la microestructura y la disminución del pH de dicha solución. Dada la complejidad del sistema y las interferencias generadas por sus múltiples componentes, el estudio de la carbonatación requiere de la combinación de diferentes técnicas de análisis. Este trabajo destaca la información adicional que aportan las técnicas de ATD/TG y espectroscopía FT-IR al estudio de la carbonatación de pastas de cemento y a la cuantificación de su avanceThe microstructure of portland cement during the hardening stage (setting) evolves due to hydration reactions occurring between water and cement. From the characterization and development of the microstructure can know the properties of the mixture, comparing the microstructure with the macrostructure. When atmospheric CO2 penetrates the pores of a Portland cement paste or concrete, changes the balance of chemical solution and hydrates. This leads to precipitation of CaCO3 , resulting in the densification of the microstructure and the decrease in interstitial pH of the solution. Given the complexity of the system and interference generated by its multi-component, study of the carbonation requires the combination of different analysis techniques. This paper highlights the information that provides techniques as DTA/TG and FT-IR spectroscopy to study the carbonation of cement pastes and quantify their progressLa microestructura del ciment portland durant l’etapa d’enduriment adormiment evoluciona a causa de les reaccions d’hidratació que tenen lloc entre l’aigua i el ciment. A partir de la caracterització i desenvolupament de la microestructura es poden conèixer les propietats de la mescla, relacionant la microestructura amb la macroestructura. Quan el CO2 atmosfèric penetra en els porus d’una pasta de ciment portland o d’un formigó, modifica l’equilibri quí- mic de la solució de porus i dels hidrats. Això condueix a la precipitació de CaCO3 , ocasionant la densificació de la microestructura i la disminució del pH de la solució. Donada la complexitat del sistema i les interferències generades pels seus múltiples components, l’estudi de la carbonatació requereix de la combinació de diferents tècniques d’anàlisi. Aquest treball destaca la informació addicional que aporten les tècniques d’ATD/TG i espectroscòpia FT-IR a l’estudi de la carbonatació de pastes de ciment i a la quantificació del seu avançFil: Trezza, Mónica Adriana. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ingenieria de Olavarria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scian, Alberto Nestor. Provincia de Buenos Aires. Gobernación. Comision de Invest.científicas. Centro de Tecnología de Recursos Minerales y Ceramica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Centro de Tecnología de Recursos Minerales y Ceramica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Russian-Ukraine war and institutional use of memetic communication: methodological opportunities and challenges

The paper aims to explore the contents conveyed by internet memes (IM) in relation to the Russia-Ukraine conflict, analysing their ability to widely spread the message through forms of communication including irony, satire and denigration. The analysis of memes raises important epistemological and methodological challenges ranging from data collection to automatic or semi-automatic analysis techniques

Draining the Water Hole: Mitigating Social Engineering Attacks with CyberTWEAK

Cyber adversaries have increasingly leveraged social engineering attacks to breach large organizations and threaten the well-being of today's online users. One clever technique, the "watering hole" attack, compromises a legitimate website to execute drive-by download attacks by redirecting users to another malicious domain. We introduce a game-theoretic model that captures the salient aspects for an organization protecting itself from a watering hole attack by altering the environment information in web traffic so as to deceive the attackers. Our main contributions are (1) a novel Social Engineering Deception (SED) game model that features a continuous action set for the attacker, (2) an in-depth analysis of the SED model to identify computationally feasible real-world cases, and (3) the CyberTWEAK algorithm which solves for the optimal protection policy. To illustrate the potential use of our framework, we built a browser extension based on our algorithms which is now publicly available online. The CyberTWEAK extension will be vital to the continued development and deployment of countermeasures for social engineering.Comment: IAAI-20, AICS-2020 Worksho

Autoactivación de cemento de escorias con polvo de vidrio de descarte

The aim of this study is to evaluate the behavior of glass powder waste as alkaline activator of slag when both are used in blended cement. The slag blended cement was prepared with 70% slag, and then the slag was replaced with 10-20% glass powder by mass. The self-activation concept is here introduced. Ground glass releases alkalis through dissolution in a slow and sustained way over time. This would activate slag. Ground glass improves fluidity of mortars and the compressive strength overcomes dilution and increases with age due to the combined pozzolanic action of slag and glass. The proposed blended cement has better mechanical properties than slag-cement. The proposed blended cement has better mechanical properties than slag-cement and due to less use of slag, it becomes more sustainable and it contributes to waste management.El objetivo del presente trabajo es evaluar el comportamiento de un residuo molido de vidrio como activador interno de la escoria cuando ambos son usados en un cemento mezcla. El cemento de escoria fue preparado con un 70% de escoria y luego la escoria se reemplazó en un 10 y 20% en masa por vidrio molido. Este trabajo introduce el concepto de auto-activación. El vidrio molido libera álcalis por disolución, en forma lenta y sostenida en el tiempo que activarían la escoria. La presencia de vidrio molido mejora la fluidez de los morteros y la resistencia a compresión supera la dilución y crece con la edad por la acción puzolánica combinada de la escoria y el vidrio. El cemento mezcla propuesto tiene mejores propiedades mecánicas que el cemento de escorias pero con menor contenido de escoria por lo que es más sustentable y contribuye al manejo de residuos

Nonlinear current-voltage characteristics due to quantum tunneling of phase slips in superconducting Nb nanowire networks

We report on the transport properties of an array of N about 30 interconnected Nb nanowires, grown by sputtering on robust porous Si substrates. The analyzed system exhibits a broad resistive transition in zero magnetic field, H, and highly nonlinear V(I) characteristics as a function of H which can be both consistently described by quantum tunneling of phase slips.Comment: accepted for publication on Appl. Phys. Let