Sandoval Yáñez, Claudia

This study explores the use of green hydrogen as a flexible and environmentally-friendly energy vector in copper mining. The refining of copper sulphide ores involves several stages, such as comminution, froth flotation and smelting. The latter produces a higher concentration of copper through chemical transformations of copper sulphide ores. Reducing agents such as coal, coke, ferrosilicon and diesel are typically used in this step, but these reagents unfortunately have a considerable environmental footprint. The main goal of this work was therefore to perform a techno-economic analysis for methane production from the use of green hydrogen as a reducing agent for the smelting stage. The methodology involved the evaluation of the project based on a Net Present Value calculation and a sensitivity analysis of the main parameters which were performed using Oracle Crystal Ball software. The main results show a Net Present Value of 5.459 M USD and an 11.8-year pay-back. Multiparametric analysis shows that NPV is positive with 97.32% of confidence and that the main variable affecting the NPV is the methane price (contribution to variance of 97,8%). We conclude that the use of green hydrogen in copper smelting is a technically viable solution with economic and environmental benefits. The economic evaluation could be further improved with the incorporation of the heat and oxygen by-product, further reducing the CO2 emission.

This paper examines the different impressions and perspectives related to the implementation of electro-mobility in log transportation via trucks with a load capacity of up to 45 tons in the forestry sector of the eighth and sixteenth regions of Chile. The objective of this work is to establish the critical variables iden-tified and perceived by key stakeholders of the fores-try industry the correct implementation of high tonnage electric trucks. To this effect, a qualitative methodologi-cal study with a non-experimental design is proposed, which is based on semi-structured interviews conduc-ted with stakeholders of the forestry sector of the study area. A convenience sample is employed, which was applied to four businessmen in the sector, three execu-tives from the main forestry companies, and two truck distributor representatives. The data show that there is currently little knowledge due to the lack of speci-fic projects and platforms for disseminating informa-tion that consider this technology in the field, but, on the contrary, they show a willingness to implement pilot plans aiming for the perceived economic sustai-nability of electromobility. A concentration of critical aspects is evidenced, which must be addressed in or-der to implement electromobility in forest transport, and which, given handling by public-private work, would enable the sector and the country to obtain the eco-nomic and environmental benefits of this technology.

This research aimed to identify the phenolic profile and composition of the aerial parts of three native species used in traditional medicine in the Andean Altiplano of northern Chile: Clinopodium gilliesii (Benth.) Kuntze [Lamiaceae] (commonly known as Muña-Muña), Mutisia acuminata Ruiz & Pav. var. hirsuta (Meyen) Cabrera [Asteraceae] (commonly known as Chinchircoma), and Tagetes multiflora (Kunth), [Asteraceae] (commonly known as Gracilis), as well as to evaluate their potential inhibitory effects against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Polyphenolic enriched-extracts (PEEs) of the species were prepared and analyzed and the main components were quantified using HPLC-DAD. In total, 30 phenolic compounds were identified and quantified in all species, including simple phenolics, hydroxycinnamic acids, flavan-3-ols (monomers and polymers), flavanones, and flavonols. In addition, other main phenolics from the extracts were tentatively identified by ESI-MS-MS high-resolution analysis. T. multiflora extract showed the greatest anti-AChE and BChE activity in comparison with C. gilliesii and M. acuminata extracts, being the anti-AChE and BChE activity weak in all extracts in comparison to galantamine control. To comprise to better understand the interactions between cholinesterase enzymes and the main phenolics identified in T. multiflora, molecular docking analysis was conducted. © 2023 by the authors.

In recent years, polymeric hydrogels (PolyHy) have been extensively explored for their applications in biomedicine as biosensors, in tissue engineering, diagnostic processes, and drug release. The physical and chemical properties of PolyHy indicate their potential use in regulating drug delivery. Calcineurin inhibitors, particularly cyclosporine (CsA) and tacrolimus (TAC), are two important immunosuppressor drugs prescribed upon solid organ transplants. Although these drugs have been used since the 1970s to significantly increase the survival of transplanted organs, there are concerns regarding their undesirable side effects, primarily due to their highly variable concentrations. In fact, calcineurin inhibitors lead to acute and chronic toxicities that primarily cause adverse effects such as hypertension and nephrotoxicity. It is suggested from the evidence that the encapsulation of calcineurin inhibitors into PolyHy based on polysaccharides, specifically alginate (Alg), offers effective drug delivery with a stable immunosuppressive response at the in vitro and in vivo levels. This not only may reduce the adverse effects but also would improve the adherence of the patients by the effective preservation of drug concentrations in the therapeutic ranges.