Proyectos

Síntesis de espinela MFe2O4 (M = Mg, Mn, Cu) mediante dos métodos de preparación. Posteriormente estos materiales serán unidos a biocarbones obtenidos desde cáscaras de avena, y se evaluarán en la degradación de contaminantes emergentes seleccionados.

Climate projections anticipate an increase in frequent droughts, episodes of extreme fire behavior, in addition to heat waves and unstable atmospheric conditions, all phenomena related to climate change. Drought intensification has been projected to increase in frequency in several regions across the globe, including the southwestern part of South America, the European Mediterranean Basin, Northern Africa, the Middle East, Central Asia, Australia, and the USA. Particularly, the former three areas have been recognized as locations highly likely to face unprecedented droughts during the 21st century, and within Southwestern South America, Chile has been alarmingly pointed out as the country earlier in this era experiencing this phenomenon, regardless of the greenhouse gas emissions scenario. Catastrophic effects such as extreme droughts and changes in fire behavior are important drivers of ecosystem degradation in arid, semiarid, dry temperate and Mediterranean ecosystems. Mediterranean ecosystems of central Chile have been indicated as the earliest in its type experiencing effects of climate change; where an accelerated aridification is already registered; therefore, representing a scenario to anticipate the effects of climate anomalies at other ecosystems of its type. Persistent droughts and land burning can compromise belowground conditions that are essential to support aboveground life in terrestrial ecosystems. Nevertheless, despite their importance for ecosystem functioning and recovery after environmental disturbances, there still a considerable lack of comprehension on how belowground attributes respond to combined stressors such as droughts and fires. This is of particular concern in conditions where post-fire plant and soil recovery have been shown to be inhibited or retarded due to severe droughts. Therefore, this project aims to evaluate individual and combined effects of drought and fires over time in soil microbial communities and carbon and nitrogen functional dynamics along with the relationship of these attributes and the state of sclerophyll vegetation in Mediterranean forests of central Chile. To accomplish this goal a multiscale approach will be applied in this research by integrating scientific disciplines from landcape ecology to molecular biology. By using remote sensing study site will be selected within an area known to be affected by an extended drought period (since 2010), in addition to hyper-dry years (2019 and 2021), which in addition has experienced the occurrence of historical wildfires as the case of 2017. From this initial screening 18 study conditions resulting from three climate anomaly categories identified (high, medium, low) according to differences in precipitation with respect to historical average, three categories for forest response to drought (recovered, unaffected and unrecovered) based on analysis of Normalized Burn Index (NBR = [NIR - SWIR] / [NIR + SWIR]) and two burned conditions (with and without) will be obtained for soil and vegetation assessments. Classical soil physicochemical analyses and NG-sequencing techniques including high-throughput amplicon sequencing (metabarcoding), whole genome sequencing (metagenomics), and gene expression (metatransciptomics), in addition to soil physiological analyses will be performed. Moreover, vegetation recovery following drought and fire will be evaluated. Results from this study will allow to better understand the individual versus the combined effects of drought and fires in soil microbial community structure and carbon and nitrogen functionality, which are expected to be exacerbated with the combined occurrence of these phenomena, giving insights on the resilience capacity of soil microbiomes and carbon and nitrogen biogeochemical cycles. From this work, results will also allow to gain a more comprehensive understanding of the linkages between soil functionality and vegetation responses to drought and fires over time, which will allow to identify ecological drivers related to ecosystem stability.

In democratic countries, the effectiveness of police work relies on having public support. When the public believes in the police's legitimate authority, they are likelier to follow their orders and cooperate with law enforcement. Conversely, perceptions of unjust behavior, such as not allowing citizens to explain themselves during interactions (procedural injustice), can lead to defiance of police orders (defiant motivational postures). In fact, over recent decades, we have witnessed numerous violent protests, police brutality, and human rights violations by police forces worldwide, including in Chile. The Carabineros, Chile's primary police force, were once highly trusted by the Chilean population. However, incidents of corruption and excessive use of force during the October 2019 social outbreak severely damaged public trust in the police (Instituto Nacional de Derechos Humanos [INDH], 2021). Therefore, it is crucial to understand the extent to which individuals perceive the police as acting fairly and correctly (i.e., procedural justice) and how they interact with and view the police in Chile (i.e., motivational postures). Additionally, it is well documented in the international literature that people who belong to minority groups (such as migrants, indigenous people, black Americans, among others) may have more tense interactions with the police and suffer higher levels of discrimination when interacting with police officers. Particularly, in Chile, there is evidence that police forces have used, both historically and in the present day, excessive use of force in particular against minority groups, namely among Mapuche people, immigrants living in Chile, as well as youths from low socioeconomic backgrounds. Therefore, we argue that these interactions between citizens and police are not only theoretically significant but also have societal implications, potentially influencing levels of conflict or cohesion within a community. Furthermore, international studies have also shown that disproportionate use of force by law enforcement often targets marginalized communities, particularly minority groups. Members of these groups also experience higher levels of discrimination compared to more privileged social groups within specific contexts (Feldman et al., 2019; Gee & Ford, 2011). Such experiences erode trust in law enforcement and may provoke protests against the police or demands for police reforms, as well as the avoidance of the police, even their work may be necessary (Woods et al., 2015). Therefore, understanding the interplay between perceptions of procedural justice (Lind & Tyler, 1988; Tyler & Lind, 1992) and motivational postures (Braithwaite, 2003) is crucial for understanding police-minority interactions. In this light, the current project aims to understand how police-minority interactions in Chile are experienced and perceived in terms of procedural justice and motivational postures by considering the perspectives of three minority groups (namely, Mapuche people, immigrants living in Chile, and youths from low socioeconomic backgrounds) and police officers. To our knowledge, there is a scarcity of studies focusing on police-minority interactions in Chile. Thus, by developing three interconnected studies with minority group members (Studies 1 and 3) and police officers (Study 2), this project’s expected results aim to, firstly, contribute to the state-of-the-art from a theoretical perspective, with the aim of advancing our understanding of police-minority interactions, through a combination of different frameworks combining procedural justice and motivational postures. Second, from a practical standpoint, we aim to generate empirical evidence that enables our understanding of police- minority interactions and provide practical guidelines and public policy recommendations about ways in which minority-police interactions can improve and lead to higher levels of procedural justice and more compliance with law enforcement. To achieve our main objective, we will conduct three interconnected studies. First, we will implement a longitudinal qualitative analysis through focus groups with minority group members (Study 1). Secondly, we will conduct semi-structured interviews with police officers (Study 2) and, finally, we will conduct an experimental study to test the causal relationship between procedural justice and motivational postures from the perspective of minority group members (Study 3). Data will be collected in the North (Antofagasta), Center (Santiago) and South (Temuco) of Chile). We expect to publish four articles in peer-reviewed journals, organize three academic seminars with national and international scholars, and present our findings in different national and international conferences. We will also organize four dissemination activities with policy makers and Human Rights Organizations concerned with police violence and how this phenomenon particularly affects minority groups, as a means to contribute to and potentially influence the development of public policies in the area of police- minority interactions. Finally, we also aim to disseminate our results among Carabineros and other relevant actors within Chilean society, as well as civil society in general.

Slope-based Variational Analysis and Optimization

Estudio de propiedades métricas y estructurales de los espacios de Wasserstein (provenientes de la teoría de transporte óptimo), y búsqueda de aplicaciones en optimización bajo incertidumbre.

The primary objective of this research is to evaluate the feasibility of using ultrasonic acoustic imaging as a non-intrusive, in situ technique to assess the plastic behavior of commercial metals and alloys. Specifically, it aims to explore the potential of ultrasonic acoustic imaging to identify and monitor various plastic deformation mechanisms in stainless steel and aluminum. The selection of materials is based on their distinct plastic deformation behaviors: aluminum releases internal energy through dislocation mechanisms, while stainless steel releases energy through deformation, first by dislocation and then by twinning. To achieve this goal, the study will continuously measure changes in sound velocity and the nonlinear acoustic parameter β while subjecting the materials to uniaxial tensile tests at different levels of applied stress. Previous studies conducted by our research group have demonstrated that changes in sound velocity, in relation to strain, offer a reliable means of quantifying dislocation density in local measurements on aluminum, copper, and stainless steel specimens. Furthermore, these studies have observed that alterations in the nonlinear acoustic parameter, specifically second harmonic generation, exhibit more pronounced changes compared to variations in linear acoustics (speed of sound). Building upon these findings, the proposed research involves the generation of both linear and nonlinear acoustic images over wider spatial regions to advance our understanding of the plastic behavior of materials undergoing different microstructural changes. The challenge of applying the results of this research to in situ measurements in the industry is not trivial, as the highly controlled laboratory conditions are not maintained in service components. In this regard, the incorporation of machine learning tools in the proposal aims to identify the parameters most sensitive to the various deformation mechanisms through clustering techniques. It is expected that the correlation of different acoustic parameters with the various plastic deformation mechanisms of both materials under study will generate an optimal database that reflects the variety of scenarios present in service components, thus paving the way for the industrial use of the proposed characterization system. The adoption of diagnostic techniques and the utilization of metallic material state analysis in service significantly enhance our ability to comprehend and control plastic deformation mechanisms, contributing to improved material reliability and robustness, and facilitating informed decision-making and maintenance strategies. Additionally, ex-situ standard microstructural tests, including XRD (X-ray diffraction), EBSD (electron backscatter diffraction), and TEM (transmission electron microscopy), will be performed to characterize the material’s state after deformation. These complementary tests will provide valuable microstructural information, enabling the correlation of deformation states with the acquired acoustic images. All the acoustic and microstructural information described above, in conjunction with previous research group data, will be stored in a robust and comprehensive database. This database will serve as the input for a Machine Learning algorithm, which will facilitate the identification of patterns of correspondence between acoustic and microstructural parameters. This approach aims to enable the future prediction, with a high level of probability, of the specific type of plastic deformation mechanism that a material is undergoing based on the acoustic parameter measurements. The successful development of this research proposal would yield several significant outcomes. Firstly, it would enable the early detection of microstructural changes in materials long before fractures occur. Moreover, it would establish a non-intrusive tool for characterizing materials by identifying the underlying mechanisms driving plastic deformation and monitoring the evolution of materials in service over time. Ultimately, this research has the potential to advance our understanding of the plastic behavior of stainless steel and aluminum, opening avenues for improved analysis, design, and performance evaluation of materials in various industrial applications.

Medium manganese steels (MMnS) are currently a subject of active scientific research due to a number of reasons. First, their unique combination of strength and ductility makes them promising candidates for lightweight structural applications in automotive and aerospace industries, where reducing weight without sacrificing mechanical properties is critical. Second, their ability to retain austenite at room temperatures offers advantages in terms of formability and resistance to hydrogen embrittlement, which are significant challenges in steel manufacturing. Third, medium Mn steels have shown potential in enhancing wear and impact resistance, making them suitable for applications in mining, construction, and machinery sectors. Additionally, their corrosion resistance and potential for cost-effective alloying with other elements further expand their utility across various engineering fields. Scientific research on medium Mn steels aims to optimize their microstructure, processing parameters, and alloy compositions to unlock their full potential, thereby contributing to the development of advanced materials that meet the performance requirements of modern industries while promoting sustainability and efficiency in manufacturing processes. The proposed research aims to investigate the stability of austenite in medium manganese steels within ternary Fe-C-Mn and Fe-C-Mn-X systems (X: Al, Si, Cr), focusing on its correlation with processing parameters. The primary objective is to assess the stability of austenite via (i) experimentally determining the martensite start temperature (thermal stability) using dilatometry and thermal analysis techniques, and (ii) to evaluate the fraction of austenite as a function of strain (mechanical stability) under tensile test. These measurements will provide crucial data to understand how variations in processing conditions influence austenite stability. Else, the study will correlate austenite stability with mechanical properties through mechanical tests and in-depth microstructural characterization, aiming to establish predictive models. Additionally, thermodynamic and kinetic calculations will aid in assessing the phase transformation behavior under different thermal histories. The research will extend its scope to evaluate impact and wear properties in relation to austenite stability, crucial for applications in industries requiring high strength and toughness, such as mining and construction. By systematically exploring these relationships, the project seeks to advance the fundamental understanding of medium Mn steels, potentially leading to the development of lightweight, durable materials with enhanced performance characteristics. Ultimately, the findings aim to contribute to the optimization of steel manufacturing processes and the realization of more efficient and reliable engineering solutions in demanding operational environments

Fondecyt de Postdoctorado 2025 Proyecto Nº 3250704, Universidad de Chile y Universidad de O'Higgins - Implementación de la investigación 'Exploración de las bases neuroanatómicas de la alteración del insight en la enfermedad de Alzheimer' como Investigador Postdoctoral

Uso de la química de elementos altamente siderófilos y calcófilos para discriminar rocas asociadas a yacimientos minerales productivos

El proyecto busca reconocer formas de co-investigación de niñas, niños y adolescentes en Chile.