A microfluidic study to investigate the effect of magnetic iron core-carbon shell nanoparticles on displacement mechanisms of crude oil for chemical enhanced oil recovery

The main objective of this work is to evaluate the effect of the simultaneous use of a surfactant mixture and magnetic iron core-carbon shell nanoparticles on oil recovery via a microfluidic study based on the rock-on-a-chip technology. The surfactant solution used for all experiments was prepared based on a field formulation and consisted of a mixture of a hydrophilic and a lipophilic surfactant. Magnetic iron core-carbon shell nanoparticles with a mean particle size of 60 nm and a surface area of 123 m2 g−1 were employed. The displacement experiments consisted of waterflooding, surfactant flooding and nanoparticle-surfactant flooding and were performed using PDMS (polydimethylsiloxane)-glass microdevices type random network. The characteristics and design of the microfluidic device allowed to emulate a mixed wettability of a porous medium. Then, the oil was displaced by injecting the solution at a constant injection rate, until steady-state conditions were obtained. Furthermore, the effect of three injection rates corresponding to 0.1 ft day−1, 1 ft day−1, and 10 ft day−1 was investigated. The increase in the injection rate favored the oil recovery percentage. In addition, for all injection rates, the oil recovery decreased in the following order: nanoparticle-surfactant flooding > surfactant flooding > waterflooding. The nanoparticle-surfactant system at the injection rate of 1.9 μL min−1 presented the highest oil recovery (i.e., 84%). Likewise, nanoparticle-surfactant flooding showed a more stable displacement front and consequently, the highest capillary number among the injection fluids. Oil recovery by waterflooding was the lowest among the evaluated systems due to the viscous fingering phenomena under different injection rates. In addition, it can be observed that for all injection rates, the presence of the surfactant mixture and nanoparticles reduce the viscous fingering effect. The results can be used to visually and quantitatively analyze the role of the simultaneous use of nanoparticles with surfactants in enhanced oil recovery processes.Fil: Betancur, Stefanía. Universidad Nacional de Colombia. Sede Medellín; Colombia. Universidad de Granada; EspañaFil: Olmos Carreno, Carol Maritza. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Colombia. Sede Medellín; Colombia. Universidad Tecnológica Nacional. Facultad Regional Haedo; ArgentinaFil: Perez, Maximiliano Sebastian. Universidad Tecnológica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Lerner, Betiana. Universidad Tecnológica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Franco, Camilo A.. Universidad Nacional de Colombia. Sede Medellin; ColombiaFil: Riazi, Masoud. Shiraz University; IránFil: Gallego, Jaime. Universidad Nacional de Colombia. Sede Medellin; Colombia. Universidad de Antioquia; ColombiaFil: Carrasco Marín, Francisco. Universidad de Granada; EspañaFil: Cortés, Farid B.. Universidad Nacional de Colombia. Sede Medellin; Colombi

Mobilitat

[p.4] Com ens hem de moure?[p.8] Mobilitat, sostenibilitat i solidaritat[p.10] Aprenent a viure d’altra manera[p.14] Sostenibilització curricular: cosa de tots[p.18] Escola-família-barri: nou espai amic[p.20] Universitats sostenibles: utopia inabastable?[p.21] Sa i estalvi[p.40] Ciutats per a cotxes o cotxes per la ciutat?[p.43] El viatge: art i consciència[p.47] Entrevista: Educació política i mobilitat a l’Índia. Ranjit Gadgil[p.50] Explica-m’ho tu![p.54] Entrevista: Ocupació verda per a una societat decarbonitzada. Michael RennerPeer Reviewe

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

A first update on mapping the human genetic architecture of COVID-19

peer reviewe

Urban acupuncture

During his three terms as mayor of Curitiba, Brazil in the 1970s and ‘80s, architect and urbanist Jaime Lerner transformed his city into a global model of the sustainable and livable community. Through his pioneering work, Lerner has learned that changes to a community don’t need to be large-scale and expensive to have a transformative impact—in fact, one block, park or a single person can have an outsized effect on life in the surrounding city. In Urban Acupuncture, his first work published in English, Lerner celebrates these “pinpricks” of urbanism—projects, people and initiatives from around the world that ripple through their communities to uplift city life. With meditative and descriptive prose, Lerner brings readers around the world to streets and neighborhoods where urban acupuncture has been practiced best, from the bustling La Boqueria market in Barcelona to the revitalization of the Cheonggyecheon River in Seoul, South Korea. Through this journey, Lerner invites us to re-examine the true building blocks of vibrant communities—the tree-lined avenues, night vendors and songs and traditions that connect us to our cities and to one another