Integrating photovoltaic solar energy and a battery energy storage system to operate a semi-autogenous grinding mill

The mining sector in Chile is facing a steady increase of energy consumption, which is mainly explained by the lower grades, the increase in rock hardness, and deeper mines. Although much of the mining activity in Chile is located in the Atacama Desert, where the solar radiation is high, the integration of solar energy in mining remains elusive. This work explores, through simulation, the use of a solar photovoltaic energy system (PV) and a battery energy storage system (BESS), combined with energy from the grid, to operate a semi-autogenous grinding mill (SAG). For this, a novel mixed-integer linear programming model was developed to optimize the operational costs of the joint SAG-PV-BESS operation, after which the best sizes of PV and BESS components are found through scenario inspection. Further, the implementation of a demand side management (DSM) option is considered by a proper sequencing of the SAG feed to make a more efficient use of the solar energy. The results show an interdependent behavior of the SAG-PV-BESS system and a strong influence of DSM. The use of both PV and BESS allows reducing the contracted power for the SAG, without incurring into overconsumption penalties. If DSM is implemented, the system allocates the higher consumption, associated to harder ore, during daytime to use the available PV energy. Overall, the combined effect of PV and BESS operation of SAG mills allows reducing the energy-associated operational costs. This effect is exacerbated when DSM is implementedThe Chilean National Commission for Scientific and Technological Research (CONICYT), through the Solar Energy Research Center SERC-Chile (FONDAP 15110019) and the Solar Mining project (CONICYT-BMBF 20140019), and the German Academic Exchange Service (DAAD)

Towards solar power supply for copper production in Chile: assessment of global warming potential using a life cycle approach

Solar energy technologies are a promising option to lower the greenhouse gas emissions of energy generation. Using solar technologies in energy-intensive industries located in arid climate zones is an attractive alternative for that purpose. In this work, the environmental benefit of integrating solar energy in the Chilean copper industry is explored in respect of global warming potential (GWP). A new life cycle assessment model for copper cathodes production in Chile and the integration of three solar technologies was developed. The GWP of the production of copper cathodes was calculated considering local representative conditions for climate, energy mix, and energy demand of the industry. It was computed at 6.0 tCO(2eq)/t Cu2 for a pyrometallurgical process (P-Cu) and 4.9 tCO(2eq)/t Cu for a hydrometallurgical process (H-Cu). Further contributions of this paper are the consideration of the decline in ore grade (i.e. copper content in the mineral) and the interconnection of Chile's two main power grids as sensitivities to the baseline. The interconnection of the power grids causes a GWP-reduction of 22% for P-Cu and 37% for H-Cu. In parallel, the expected lower ore grade by 2020 would increase the GWP of copper production by 10% for P-Cu and 4% for H-Cu. If the electricity that is currently taken from the grid is exclusively fed by solar technologies, the reduction on the GWP of copper production would be up to 63% and 76% for P-Cu and H-Cu processes. These numbers do not represent the upper bound for the reduction on the GWP of copper production that can be achieved with solar technologies because the substitution of on- site fossil fuel combustion with solar energy is another interesting mitigation option, which was not considered in this study. In order to achieve even less carbon-intensive production processes, an improved understanding of the copper's industry energy flows and profiles is needed. This would allow to assess the integration of further solar energy technologies and conceive the future of solar copper mining.Chilean Council of Scientific and Technological Research through the Solar Energy Research Center SERC-Chile CONICYT/FONDAP/15110019 Solar Mining project [Program for International Cooperation/CONICYT-BMBF] 20140019 FCFM grant University of Chil

Sunset or sunrise? Understanding the barriers and options for the massive deployment of solar technologies in Chile

The use of solar technologies should proliferate in Chile as half of the country has a solar irradiance (GHI) above 5 kWh/(m(2)d). Moreover, the Atacama Desert exhibits further advantageous conditions with 7 kWh/(m(2)d), clear skies and a large energy-consuming mining industry. Since 2012 the solar sector takes off, totalizing over 1600 MW, of solar power and about 100 MWt of solar heat installed by the end of 2016. However, only about 10% of the filed projects are operative; many barriers are slowing down the further development of solar technologies. While several barrier studies for solar technologies exist in the literature, they are often country-specific and there is no publication found regarding the Chilean solar sector. In the present paper, the barriers obstructing the way of Chile becoming a solar power country are found through interviews and then analyzed and classified into six groups (economic, market, system integration, technical, regulatory and information barriers). For these barriers, an overview of emerging mitigation options are provided and future solutions, including opportunities for research, are proposed.Chilean Council of Scientific and Technological Research through the Solar Energy Research Center SERC-Chile CONICYT/FONDAP/15110019 Chilean Council of Scientific and Technological Research through Solar Mining project [Program for International Cooperation] CONICYT-BMBF/2014001

Effectiveness of the combination elvitegravir/cobicistat/tenofovir/emtricitabine (EVG/COB/TFV/FTC) plus darunavir among treatment-experienced patients in clinical practice : A multicentre cohort study

Background: The aim of this study was to investigate the effectiveness and tolerability of the combination elvitegravir/cobicistat/tenofovir/emtricitabine plus darunavir (EVG/COB/TFV/FTC + DRV) in treatment-experienced patients from the cohort of the Spanish HIV/AIDS Research Network (CoRIS). Methods: Treatment-experienced patients starting treatment with EVG/COB/TFV/FTC + DRV during the years 2014-2018 and with more than 24 weeks of follow-up were included. TFV could be administered either as tenofovir disoproxil fumarate or tenofovir alafenamide. We evaluated virological response, defined as viral load (VL) < 50 copies/ml and < 200 copies/ml at 24 and 48 weeks after starting this regimen, stratified by baseline VL (< 50 or ≥ 50 copies/ml at the start of the regimen). Results: We included 39 patients (12.8% women). At baseline, 10 (25.6%) patients had VL < 50 copies/ml and 29 (74.4%) had ≥ 50 copies/ml. Among patients with baseline VL < 50 copies/ml, 85.7% and 80.0% had VL < 50 copies/ml at 24 and 48 weeks, respectively, and 100% had VL < 200 copies/ml at 24 and 48 weeks. Among patients with baseline VL ≥ 50 copies/ml, 42.3% and 40.9% had VL < 50 copies/ml and 69.2% and 68.2% had VL < 200 copies/ml at 24 and 48 weeks. During the first 48 weeks, no patients changed their treatment due to toxicity, and 4 patients (all with baseline VL ≥ 50 copies/ml) changed due to virological failure. Conclusions: EVG/COB/TFV/FTC + DRV was well tolerated and effective in treatment-experienced patients with undetectable viral load as a simplification strategy, allowing once-daily, two-pill regimen with three antiretroviral drug classes. Effectiveness was low in patients with detectable viral loads

COVID-19 in hospitalized HIV-positive and HIV-negative patients : A matched study

CatedresObjectives: We compared the characteristics and clinical outcomes of hospitalized individuals with COVID-19 with [people with HIV (PWH)] and without (non-PWH) HIV co-infection in Spain during the first wave of the pandemic. Methods: This was a retrospective matched cohort study. People with HIV were identified by reviewing clinical records and laboratory registries of 10 922 patients in active-follow-up within the Spanish HIV Research Network (CoRIS) up to 30 June 2020. Each hospitalized PWH was matched with five non-PWH of the same age and sex randomly selected from COVID-19@Spain, a multicentre cohort of 4035 patients hospitalized with confirmed COVID-19. The main outcome was all-cause in-hospital mortality. Results: Forty-five PWH with PCR-confirmed COVID-19 were identified in CoRIS, 21 of whom were hospitalized. A total of 105 age/sex-matched controls were selected from the COVID-19@Spain cohort. The median age in both groups was 53 (Q1-Q3, 46-56) years, and 90.5% were men. In PWH, 19.1% were injecting drug users, 95.2% were on antiretroviral therapy, 94.4% had HIV-RNA < 50 copies/mL, and the median (Q1-Q3) CD4 count was 595 (349-798) cells/μL. No statistically significant differences were found between PWH and non-PWH in number of comorbidities, presenting signs and symptoms, laboratory parameters, radiology findings and severity scores on admission. Corticosteroids were administered to 33.3% and 27.4% of PWH and non-PWH, respectively (P = 0.580). Deaths during admission were documented in two (9.5%) PWH and 12 (11.4%) non-PWH (P = 0.800). Conclusions: Our findings suggest that well-controlled HIV infection does not modify the clinical presentation or worsen clinical outcomes of COVID-19 hospitalization

How do women living with HIV experience menopause? Menopausal symptoms, anxiety and depression according to reproductive age in a multicenter cohort

CatedresBackground: To estimate the prevalence and severity of menopausal symptoms and anxiety/depression and to assess the differences according to menopausal status among women living with HIV aged 45-60 years from the cohort of Spanish HIV/AIDS Research Network (CoRIS). Methods: Women were interviewed by phone between September 2017 and December 2018 to determine whether they had experienced menopausal symptoms and anxiety/depression. The Menopause Rating Scale was used to evaluate the prevalence and severity of symptoms related to menopause in three subscales: somatic, psychologic and urogenital; and the 4-item Patient Health Questionnaire was used for anxiety/depression. Logistic regression models were used to estimate odds ratios (ORs) of association between menopausal status, and other potential risk factors, the presence and severity of somatic, psychological and urogenital symptoms and of anxiety/depression. Results: Of 251 women included, 137 (54.6%) were post-, 70 (27.9%) peri- and 44 (17.5%) pre-menopausal, respectively. Median age of onset menopause was 48 years (IQR 45-50). The proportions of pre-, peri- and post-menopausal women who had experienced any menopausal symptoms were 45.5%, 60.0% and 66.4%, respectively. Both peri- and post-menopause were associated with a higher likelihood of having somatic symptoms (aOR 3.01; 95% CI 1.38-6.55 and 2.63; 1.44-4.81, respectively), while post-menopause increased the likelihood of having psychological (2.16; 1.13-4.14) and urogenital symptoms (2.54; 1.42-4.85). By other hand, post-menopausal women had a statistically significant five-fold increase in the likelihood of presenting severe urogenital symptoms than pre-menopausal women (4.90; 1.74-13.84). No significant differences by menopausal status were found for anxiety/depression. Joint/muscle problems, exhaustion and sleeping disorders were the most commonly reported symptoms among all women. Differences in the prevalences of vaginal dryness (p = 0.002), joint/muscle complaints (p = 0.032), and sweating/flush (p = 0.032) were found among the three groups. Conclusions: Women living with HIV experienced a wide variety of menopausal symptoms, some of them initiated before women had any menstrual irregularity. We found a higher likelihood of somatic symptoms in peri- and post-menopausal women, while a higher likelihood of psychological and urogenital symptoms was found in post-menopausal women. Most somatic symptoms were of low or moderate severity, probably due to the good clinical and immunological situation of these women