Browsing by Author "Lagos, Gustavo"
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- ItemA method to estimate the robustness of the secondary refined copper supply function(2023) Rivera, Nilza; Ignacio Guzman, Juan; Lagos, GustavoKnowing the factors that influence the secondary refined copper supply behavior has been fundamental in generating a copper market model and developing public and corporate policies. When analyzing the explanatory variables used in the existing models in the literature, it is possible to observe high variability in estimating the parameters when modifying the availability of information or changing the observation period. Based on this, we argue that only some explanatory variables will have robust estimated parameters, which means that they are unbiased, stable (i.e., they do not vary significantly when the specification of the equation or the number of observations changes), and with asymptotic convergence over time. This work defines and validates a method to select robust explanatory variables capable of quantifying the refined secondary supply of copper (or any other variable) in a given period. Using a database with 23 explanatory variables in the period 1960-2017, we characterize the estimated parameters with high and low robustness, thus supporting the proposed hypothesis. The results obtained allowed identifying those variables with low uncertainty in estimating their parameters, with a high statistical significance, and with a low standard deviation. This allows to obtain a robust function for the secondary refined copper supply in the long term, capturing essential elements of reality.
- ItemAnálisis y estudio de modelos econométricos de la oferta secundaria refinada de cobre(2022) Rivera Bonilla, Nilza; Sauma Santis, Enzo Enrique; Lagos, Gustavo; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
- ItemApplication of Polypyrrole/Humic Acid Composite Electrode for Copper Ion Extraction from Drinking Water(2012) Antilén Lizana, Mónica; Guzmán de la Cerda, Diego José Edgardo; Valle de la Cortina, María Angélica del; Río Quero, Rodrigo del; Letelier Solar, María Victoria; Lagos, Gustavo; Escudey, Mauricio; Pizarro, Carmen
- ItemAttracting mining investments: the relationship between natural endowments and public policies(2020) Jara Donoso, José Joaquín; Delucchi Danhier, Stefano Andreas; Peters Nuñez, David; Lagos, Gustavo; Marquardt R., CarlosMining jurisdictions avid to attract international investments to find and exploit their mineral deposits contend for international capitals. This led to policymakers, analysts, and companies to think about the factors affecting the competitiveness of mining districts. The traditional paradigm states that the capacity of a country or jurisdiction to attract investments and develop its local industry is a function exclusively of the quantity and quality of the ore deposits within its territory. On the other hand, the alternative view suggests that the previous conception is incomplete, because companies not only look for a good geologic potential but also for a favorable investment climate (Tilton 1992). Through cross-country econometric models covering the years 1996 to 2014, this work supports the alternative paradigm of mining competitiveness and tries to contribute to a better understanding of the relationship between the geological potential and the investment climate when determining the attraction of mining investments. The study concludes that, in order to develop a local mining industry, a country should have a wealthy natural endowment, but also it must offer a good investment climate. In addition, it shows that both variables are related through a multiplicative effect, but once public policies and other contextual variables reach certain reasonable levels (the “investment climate threshold”), jurisdictions compete almost exclusively based on its natural endowment. These results have significant implications for the implementation of public policies, especially in periods when mining contribution to social welfare is under scrutiny.
- ItemEfecto de la ley del mineral en el consumo de energía y agua, y las emisiones GEI en la minería del cobre(2018) Cejas Aldunate, Javier Ignacio; Lagos, Gustavo; Pontificia Universidad Católica de Chile. Escuela de IngenieríaNumerosas investigaciones sostienen que la ley promedio de cobre en los yacimientos en explotación de dicho metal a nivel global se ha ido reduciendo en el tiempo y que esta tendencia continuará. Ello constituye un factor clave en el aumento de la huella ambiental cuando esta se mide en términos del consumo de agua, de energía y de emisiones de gases efecto invernadero. En 2015, el 81% del total de la producción de cobre refinado de mina a nivel mundial se obtuvo en plantas concentradoras, cuya alimentación son minerales en base a sulfuros, y cuyo producto son los concentrados de cobre. Estos contienen una ley de cobre aproximadamente 30 veces superior a la roca mineralizada que ingresa a las plantas concentradoras. En este artículo se desarrollan modelos para estimar el consumo energético y de agua, al igual que las emisiones de GEI, en función de la ley de cobre del material que ingresó a las plantas concentradoras de diez minas chilenas explotadas a cielo abierto, que representaron el 67% de la producción de Chile en 2016. Los modelos desarrollados incluyen los alcances uno, dos y tres de un análisis de ciclo de vida.
- ItemEvaluation of econometric models of secondary refined copper supply(2021) Rivera, Nilza; Ignacio Guzman, Juan; Joaquin Jara, Jose; Lagos, GustavoCopper is essential in attaining a sustainable development path due to its prominent role in the electromobility and renewable energy industries. In 2019 refined copper usage was 23.5 million tons, of which primary copper supplied 86.3%, and the remaining 13.7% was provided by secondary metal. In the future, copper recycling would increase significantly concerning primary copper supply to meet the goal of decreasing greenhouse gases emissions. Secondary copper production reduces energy consumption by 85% and greenhouse gas emissions by 65% compared to average primary sources.
- ItemRelationship Between Soil Copper Content and Copper Content of Selected Crop Plants in Central Chile(2001) Badilla Ohlbaum, Ricardo; Ginocchio Cea, Rosanna; Lagos, Gustavo
- ItemSummer exposure assessment of Cu and Zn in drinking water in Shanghai, China(TAYLOR & FRANCIS INC, 2006) Xu, Peng; Lagos, Gustavo; Huang, Shengbiao; Wang, ZijianDaily exposures to chemicals in drinking water are of importance in risk assessment to human health. However, exposure assessment of chemicals in drinking water has seldom been performed in China. Until now, no such a detailed exposure assessment was reported in China. The aim of the present paper is to describe the scenes of daily exposure to Cu and Zn in drinking water by the population of Shanghai, China in the summer of 2003. A total of 163 volunteers and/or homes were selected to be statistically representative of the population of Shanghai, China. The Modified Consumption Habit Exposure Model (CHEM) method combined with the measurement of metals concentrations in stagnant water and actual ingested water was used to describe the daily exposure. The Consumption Habit Exposure Model method results showed that water consumption ranged from 1.7 to 2.2 L/day, varied with different age, gender and work location groups. Chemical results showed that the average Cu and Zn concentrations in stagnant water were much higher than those in actual ingested water (13.5 mu g/L and 1.55 mg/L vs. 10.8 mu g/L and 0.29 mg/L). Exposure assessment results also showed that volunteers had the highest exposure from the time of after breakfast to before dinner, and had the lowest exposure during the 15 minutes before sleeping. It was also showed that there were few volunteers directly exposed to stagnant water, although six hours stagnant time can be reached in most of the homes in Shanghai in the morning. The mean daily exposures to Cu and Zn were 0.36 mu g/kg/day and 0.01 mg/kg/day. Daily intakes of Cu and Zn from drinking water by Shanghai people were 1.8% and 4.4% of the World Health Organization recommendations for minimum total intakes of Cu and Zn for adults, respectively.