University of Tarapacá

The increase in the concentration of carbon dioxide (CO2) in the earth’s atmosphere is one of the major environmental challenges of our time, playing a significant role in climate change. The conversion of CO2 into valuable fuels and chemicals is a promising approach to mitigate the impact of this greenhouse gas and utilize it as a renewable carbon source. This article reviews various CO2 conversion routes, including reverse water gas shift (RWGS), methanol synthesis, conversion to olefins, dimethyl ether (DME), and formic acid, and analyzes their thermodynamic and selectivity aspects. Next, the role of molten salt catalysts in CO2 activation is reviewed, with a focus on their physicochemical properties and the roles of anions and cations. Also, metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are introduced as novel catalytic substrates for CO2 reduction, hydrogenation, and photoconversion. Mechanistic studies, hybrid systems (such as combining MOFs with quantum dots or metal nanoparticles), and electric field effects and surface phenomena in plasmonic substrates are also reviewed. Finally, current challenges, technical and research limitations, and future perspectives on the development of CO2 conversion technologies are presented.

Urban expansion in Chile has proceeded so quickly that it has overwhelmed city planners and their efforts to implement sustainable recycling systems. The possibility of recycling in 16 Chilean regions is analyzed in this work, employing a new type of decision-support framework that combines expert opinion (under uncertainty) and objective information analysis through fuzzy logic. First, we elicit stakeholder opinions as simple degrees of belief expressed in natural language using a fuzzy degree modifier to model the vagueness encountered in real-world applications. Then we obtain data-driven weights by assessing the uncertainty and conflicts of each criterion. We then combine such subjective and objective weights using a multisourcing aggregation approach to derive stable regional comparisons. The findings highlight Governance Policy and Infrastructure Technology as the two most important dimensions for a successful urban recycling programme. Areas like Biobío and Valparaíso stand out as star performers, with practical lessons for policy. This framework is designed to balance simplicity and understanding for non-experts, while offering empirical robustness for domain experts. It can also be used in investment and regulatory decisions to enhance Chile's circular economy (CE).

Heatwaves (HW) are among the most impactful climate-related hazards, with increasing consequences for human health, ecosystems, and infrastructure under ongoing global warming. Despite growing attention worldwide, their characterization in South America remains limited, particularly from a biometeorological perspective. This study aims to characterize heatwave intensity, frequency, duration, and spatial extent in continental Chile using the excess heat factor (EHF) index, and to identify the synoptic conditions associated with representative extreme events. We apply the EHF index to high-resolution gridded temperature data covering the period 1979–2018 and analyze its components to assess multiple dimensions of HW behavior. In addition, we evaluate temporal trends and perform a synoptic characterization of three representative events in northern (Arica), central (Santiago), and southern (Puerto Montt) Chile. The results reveal a marked geographic contrast in HW dynamics: central Chile exhibits the highest intensity and recurrence, northern Chile shows longer and more variable events, and southern Chile, although historically less affected, is increasingly exposed. Significant positive trends are observed in HW intensity, duration, and spatial extent, with a notable expansion of affected areas after 2000, when median national HW coverage frequently exceeds 40–60

We investigate first- and second-order optimality conditions for constrained optimization problems with interval-valued objective functions. By introducing new directional derivatives based on generalized Hukuhara differences, we establish necessary and sufficient optimality conditions. The proposed conditions extend existing results and remain applicable even when the endpoint functions of the interval are nonsmooth or nonconvex. Important statements are illustrated by examples.

Debates on the ethical status of disembodied neural organoids (DNOs) focus on whether, and when, precautionary principles should apply given the uncertain possibility of organoid consciousness. Some advocate applying precautionary principles to DNOs despite uncertainty; others deem such measures premature given current simplicity but foresee their future necessity; while more skeptical views hold that genuinely conscious DNOs remain too remote to warrant present ethical concern. By contrast, Croxford and Bayne [1] defend a more radical skepticism, as they claim that there is little reason to ascribe consciousness not only to current DNOs, but to DNOs as such. They ground this view on a constraint-based approach composed of an Embodiment Constraint (EC) and a Representational Constraint. EC is presented as enjoying broad cross-theoretical support among externalists and internalists, and thus undermining the grounds for a precautionary ethical concern regarding DNOs. We examine EC and argue that, as stated, fails to meet the authors’ own requirement of representing a broad consensus among externalists and internalists.