Leaching of pure chalcocite in a chloride media using sea water and wastewater

Chalcocite is the most important and abundant secondary copper ore in the world with a rapid dissolution of copper in an acid-chloride environment. In this investigation, the methodology of surface optimization will be applied to evaluate the e_ect of three independent variables (time, concentration of sulfuric acid and chloride concentration) in the leaching of pure chalcocite to extract the copper with the objective of obtaining a quadratic model that allows us to predict the extraction of copper. The kinetics of copper dissolution in regard to the function of temperature is also analyzed. An ANOVA indicates that the linear variables with the greatest influence are time and the chloride concentration. Also, the concentration of chloride-time exerts a significant synergic e_ect in the quadratic model. The ANOVA indicates that the quadratic model is representative and the R2 value of 0.92 is valid. The highest copper extraction (67.75%) was obtained at 48 h leaching under conditions of 2 mol/L H2SO4 and 100 g/L chloride. The XRD analysis shows the formation of a stable and non-polluting residue; such as elemental sulfur (S0). This residue was obtained in a leaching time of 4 h at room temperature under conditions of 0.5 mol/L H2SO4 and 50 g/L Cl.The authors are grateful for the contribution of the Scientific Equipment Unit- MAINI of the Universidad Católica del Norte for aiding in generating data by automated electronic microscopy QEMSCAN® and for facilitating the chemical analysis of the solutions. We are also grateful to the Altonorte Mining Company for supporting this research and providing slag for this study, and we thank to Marina Vargas Aleuy and María Barraza Bustos of the Universidad Católica del Norte for supporting the experimental tests

Contested Territories: Water Rights and the Struggles over Indigenous Livelihoods

This paper examines the threats to Indigenous water rights and territories in the Andean countries. It analyzes how water and water rights are embedded in Indigenous territories, and how powerful actors and intervention projects tend to undermine local societies and indigenous livelihoods by developing large-scale water infrastructure. Three cases illustrate the encroachment process. In Colombia, the Embera Katio people’s water territory is colonized by a large-scale hydropower development project. In Ecuador, large-scale drinking water development for megacities aims the water belonging to the Oyacachi community’s indigenous highland territory. In Peru, communal water rights of the Colca Valley indigenous peasantry are under threat because of large-scale irrigation development. As the cases show, Indigenous peoples and communities actively contest the undermining and subordination of their water and territorial rights through a myriad of multi-scalar livelihood defense strategies. The challenges that indigenous peoples face to defend their water-based livelihoods are, however, enormous and growing every day

Peruvian eats healthy

Comida saludable; alimentación nutritiva; salud; bienestar, DeliveryEl presente documento expone el plan de negocios y desarrollo para la puesta en marcha de un restaurante de bufette de comida saludable en la ciudad de Lima, “PERUANO COME SANO”. Dedicado a vender platos compuestos de alimentos saludables y nutrientes con peso y medidas adecuadas. Ofreciendo un producto innovador en el mercado, que brinda una alternativa de tener comida fresca, saludable y de calidad, ordenada desde la comodidad de su casa o atendido en el local. Se muestra el estudio de mercado realizado con el fin de conocer las percepciones, necesidades y expectativas de los clientes potenciales frente a la idea de negocio. De acuerdo con el análisis del mercado, se crearon las estrategias de mercado y comerciales. Se realizó un estudio técnico, analizando los estudios y la factibilidad de procesos operativos, con los costos y el capital requerido para la puesta en marcha. En este criterio se realizó un análisis de las necesidades de compra de máquinas, equipos y materias primas. En el plan organizacional se presenta la estructura del negocio y justificación del tipo de sociedad que se creó. En el análisis financiero se refleja en cifras el comportamiento esperado del plan de negocio y la diferenciación con respecto al nuevo funcionamiento de “Peruano Come Sano”; se analiza la rentabilidad del negocio, utilizando herramientas como el valor presente neto y la tasa interna de retorno, factores que soportan los hallazgos de este de éxito del negocio.This document sets out the business and development plan for the launch of a healthy food restaurant in the city of Lima, "PERUANO COME SANO". Dedicated to a seller of dishes composed of healthy foods and nutrients with appropriate weight and measurements. Offering an innovative product in the market, offering an alternative of having fresh, healthy and quality food, ordered from the comfort of your home or served on the premises. The market study carried out in order to know the perceptions, needs and expectations of potential customers regarding the business idea is shown. Based on the market analysis, create the market and trading strategies. A technical study was carried out, analyzing the studies and the feasibility of operating processes, with the costs and capital required for start-up. In this criterion, an analysis was made of the purchase needs of machines, equipment and raw materials. The organizational plan presents the business structure and the justification for the type of company that was created. In the financial analysis, the expected behavior of the business plan and the differentiation with respect to the new operation of "Peruano Come Sano" are reflected in figures; Analyzes the profitability of the business, uses tools such as net present value and internal rate of return, factors that support the findings of this business success.Trabajo de investigació

Quantification of the Number of Steps in a School Recess by Means of Smart Bands: Proposal of Referential Values for Children and Adolescents

(1) Background: Regular physical activity has multiple benefits. Therefore, school recess is a key tool to provide opportunities for schoolchildren to engage in extracurricular physical activity, have fun, play and interact with their peers. The aim is to provide reference data to quantify the number of steps that children and adolescents perform in a school recess using smart bands according to age range and sex. (2) Method: A descriptive cross-sectional study was carried out in 494 schoolchildren aged 6 to 17 years (292 males and 202 females). Weight, standing height and waist circumference (WC) were evaluated. The body mass index (BMI) was calculated. The quantification of the number of steps during school recess was performed using a smart band. (3) Results: Percentiles were constructed for the number of steps (number of steps/recess). The cut-off points considered were p75 (above average). The median values in both sexes decreased as the age range increased. Youth who walked fewer steps during recess (<p25: below average) had elevated BMI and WC values relative to those who walked within average and above average. (4) Conclusion: The number of steps taken by schoolchildren during school recess decreases drastically with advancing age. The proposed reference values can be used to categorize schoolchildren according to the number of steps taken and to compare them among their peers. The results suggest their use and application in schools as a way of achieving the minimum physical activity recommendations

Reference values for the 6-min walking test in children and adolescents living in a moderate altitude region of Peru

Abstract Background The assessment of cardiorespiratory fitness is important because it allows the identification of subgroups with poor health status and the targeting of effective intervention strategies to improve health. Objective To compare the cardiorespiratory capacity of children and adolescents living in a moderate altitude region of Peru with international studies and to develop reference values for the 6-min walk test (6MWT) according to age and sex. Methodology A descriptive cross-sectional study of schoolchildren from a region of moderate altitude in Peru was carried out. A total of 704 schoolchildren (400 males and 304 females) with an age range of 6 to 17 years were studied. Weight, standing height, waist circumference (WC), body mass index (BMI) and tri-ponderal mass index (TMI) were evaluated. The 6MWT was assessed in a straight line over a distance of 30 m. Percentiles were created through the LMS method [L (skewness: lambda), M (median: mu) and S (coefficient of variation: Mu)]. Results There were discrepancies in cardiorespiratory fitness performance with international studies by age and sex. The schoolchildren in the study reached stability and the highest number of meters in the last two age ranges (14 to 15 years: 698.1 m and 16 to 17 years 686.3 m in males). While females (14 to 15 years: 698.1 m and 16 to 17 years: 686.3 m). The proposed percentile values show ascending values as age advances. The cut-off points adopted are: low cardiorespiratory fitness  75. Conclusion We verified that the cardiorespiratory fitness evaluated by means of the 6MWT is ascending with the course of age. Even the performance with other countries is heterogeneous at early and middle ages, stabilizing during adolescence. The proposed reference values can be used to evaluate and monitor cardiorespiratory fitness during physical education classes

De villanos, enemigos y abominaciones en la imaginería moderna

Universidad Nacional Autónoma de México/Programa de Apoyo a Proyectos de Investigación e Innovación/"PAPIIT IN 401216"//[La construcción simbólica del enemigo en el imaginario latinoamericano: orígenes, continuidades y rupturas]Las imágenes de villanía que figuran en este libro son recurrentes y representativas del modo en que construye al enemigo para afianzar idas sobre la maldad humana. Se trata de elementos que deseamos desmontar para poder comprender los símbolos de la enemistad socialmente construida. En esta obra nos hemos acercado a explorar los procesos y manifestaciones de la proyección imaginaria condenatoria, que permite a una comunidad -a veces con razón y otras visceralmente- la exclusión antagonista de un adversario imaginado. El trabajo colectivo ha dado por resultado esta obra, en la que se abordan imágenes de enemistad, desde disciplinas afines y que comparten aproximaciones sobre la figura del hostil. En el libro se presentan diversas formas estigmatizadas como enemigas, y que son alegorías de una realidad conflictiva y compleja, sostenida en la determinación estratégica del enemigo: desnaturalizarlo es dar pasos hacia una hospitalidad intercultural.Libro

Epidemiological characteristics, practice of ventilation, and clinical outcome in patients at risk of acute respiratory distress syndrome in intensive care units from 16 countries (PRoVENT): an international, multicentre, prospective study

Background Scant information exists about the epidemiological characteristics and outcome of patients in the intensive care unit (ICU) at risk of acute respiratory distress syndrome (ARDS) and how ventilation is managed in these individuals. We aimed to establish the epidemiological characteristics of patients at risk of ARDS, describe ventilation management in this population, and assess outcomes compared with people at no risk of ARDS. Methods PRoVENT (PRactice of VENTilation in critically ill patients without ARDS at onset of ventilation) is an international, multicentre, prospective study undertaken at 119 ICUs in 16 countries worldwide. All patients aged 18 years or older who were receiving mechanical ventilation in participating ICUs during a 1-week period between January, 2014, and January, 2015, were enrolled into the study. The Lung Injury Prediction Score (LIPS) was used to stratify risk of ARDS, with a score of 4 or higher defining those at risk of ARDS. The primary outcome was the proportion of patients at risk of ARDS. Secondary outcomes included ventilatory management (including tidal volume [VT] expressed as mL/kg predicted bodyweight [PBW], and positive end-expiratory pressure [PEEP] expressed as cm H2O), development of pulmonary complications, and clinical outcomes. The PRoVENT study is registered at ClinicalTrials.gov, NCT01868321. The study has been completed. Findings Of 3023 patients screened for the study, 935 individuals fulfilled the inclusion criteria. Of these critically ill patients, 282 were at risk of ARDS (30%, 95% CI 27\u201333), representing 0\ub714 cases per ICU bed over a 1-week period. VT was similar for patients at risk and not at risk of ARDS (median 7\ub76 mL/kg PBW [IQR 6\ub77\u20139\ub71] vs 7\ub79 mL/kg PBW [6\ub78\u20139\ub71]; p=0\ub7346). PEEP was higher in patients at risk of ARDS compared with those not at risk (median 6\ub70 cm H2O [IQR 5\ub70\u20138\ub70] vs 5\ub70 cm H2O [5\ub70\u20137\ub70]; p&lt;0\ub70001). The prevalence of ARDS in patients at risk of ARDS was higher than in individuals not at risk of ARDS (19/260 [7%] vs 17/556 [3%]; p=0\ub7004). Compared with individuals not at risk of ARDS, patients at risk of ARDS had higher in-hospital mortality (86/543 [16%] vs 74/232 [32%]; p&lt;0\ub70001), ICU mortality (62/533 [12%] vs 66/227 [29%]; p&lt;0\ub70001), and 90-day mortality (109/653 [17%] vs 88/282 [31%]; p&lt;0\ub70001). VT did not differ between patients who did and did not develop ARDS (p=0\ub7471 for those at risk of ARDS; p=0\ub7323 for those not at risk). Interpretation Around a third of patients receiving mechanical ventilation in the ICU were at risk of ARDS. Pulmonary complications occur frequently in patients at risk of ARDS and their clinical outcome is worse compared with those not at risk of ARDS. There is potential for improvement in the management of patients without ARDS. Further refinements are needed for prediction of ARDS

Geoeconomic variations in epidemiology, ventilation management, and outcomes in invasively ventilated intensive care unit patients without acute respiratory distress syndrome: a pooled analysis of four observational studies

Background: Geoeconomic variations in epidemiology, the practice of ventilation, and outcome in invasively ventilated intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) remain unexplored. In this analysis we aim to address these gaps using individual patient data of four large observational studies. Methods: In this pooled analysis we harmonised individual patient data from the ERICC, LUNG SAFE, PRoVENT, and PRoVENT-iMiC prospective observational studies, which were conducted from June, 2011, to December, 2018, in 534 ICUs in 54 countries. We used the 2016 World Bank classification to define two geoeconomic regions: middle-income countries (MICs) and high-income countries (HICs). ARDS was defined according to the Berlin criteria. Descriptive statistics were used to compare patients in MICs versus HICs. The primary outcome was the use of low tidal volume ventilation (LTVV) for the first 3 days of mechanical ventilation. Secondary outcomes were key ventilation parameters (tidal volume size, positive end-expiratory pressure, fraction of inspired oxygen, peak pressure, plateau pressure, driving pressure, and respiratory rate), patient characteristics, the risk for and actual development of acute respiratory distress syndrome after the first day of ventilation, duration of ventilation, ICU length of stay, and ICU mortality. Findings: Of the 7608 patients included in the original studies, this analysis included 3852 patients without ARDS, of whom 2345 were from MICs and 1507 were from HICs. Patients in MICs were younger, shorter and with a slightly lower body-mass index, more often had diabetes and active cancer, but less often chronic obstructive pulmonary disease and heart failure than patients from HICs. Sequential organ failure assessment scores were similar in MICs and HICs. Use of LTVV in MICs and HICs was comparable (42·4% vs 44·2%; absolute difference -1·69 [-9·58 to 6·11] p=0·67; data available in 3174 [82%] of 3852 patients). The median applied positive end expiratory pressure was lower in MICs than in HICs (5 [IQR 5-8] vs 6 [5-8] cm H2O; p=0·0011). ICU mortality was higher in MICs than in HICs (30·5% vs 19·9%; p=0·0004; adjusted effect 16·41% [95% CI 9·52-23·52]; p&lt;0·0001) and was inversely associated with gross domestic product (adjusted odds ratio for a US$10 000 increase per capita 0·80 [95% CI 0·75-0·86]; p&lt;0·0001). Interpretation: Despite similar disease severity and ventilation management, ICU mortality in patients without ARDS is higher in MICs than in HICs, with a strong association with country-level economic status