5 research outputs found

    Static Model of Cement Rotary Kiln

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    En este trabajo, se presenta un modelo estático de un horno rotatorio de cemento. El modelo del sistema se obtiene a través de series de polinomio. El modelo propuesto se verifica con datos reales de la planta, donde se obtuvieron resultados óptimos. Los resultados esperados son medidos con respecto a la producción de Clinker. El consumo de combustible se mide en relación con el consumo calorífico. Los resultados esperados del enfoque es el incremento de los beneficios de la empresa a través de la reducción en el consumo de combustible.In this paper, a static model of cement rotary kilns is proposed. The system model is obtained through polynomial series. The proposed model is contrasted with data of a real plant, where optimal results are obtained. Expected results are measured with respect to the clinker production and the combustible consumption is measured in relation with the consumption calorific. The expected result of the approach is the increase of the profitability of the factory through the decrease of the consumption of the combustible

    Design Robust Controller for Rotary Kiln

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    En este artículo se presenta el diseño de un controlador robusto para un horno rotativo. El controlador diseñado es una combinación de un PID fraccionario y un regulador cuadrático lineal (LQR por su sigla en inglés, Linear Quadratic Regulator), los cuales no se han usado, hasta ahora, para controlar un horno rotatorio, además se evalúan los criterios de robustez (margen de ganancia, margen de fase, robustez de ganancia, sensibilidad y rechazo de ruido de alta frecuencia) aplicados al modelo completo (controlador-planta), obteniendo óptimos resultados en un rango de frecuencia de 0.020 a 90 rad/s, lo cual contribuye con la robustez del sistema.This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR), these are not used to control the kiln until now, in addition robustness criteria are evaluated (gain margin, phase margin, strength gain, rejecting high frequency noise and sensitivity) applied to the entire model (controller-plant), obtaining good results with a frequency range of 0.020 to 90 rad/s, which contributes to the robustness of the system

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Combustion System Model of a Wet Process Clinker Kiln

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    This paper presents the model of the combustion process of a clinker kiln, which is obtained from an energy balance represented in the heat generated by burning coal and how this is distributed across the process. Data comes from the actual process variables, obtained from the control system using OLE for Process Control, which operates using experimental data and variables that are assumed to be constant. The resulting model is fitted with two tools: least squares and Infinite Impulse Response filter of first order. It validates and verifies the model and its settings using two statistical tools: box and whisker diagram and method of eight statistical metrics related by a fuzzy function. The use of these tools evidence satisfactory performance of the proposed model.En este trabajo se presenta el modelo del proceso de combustión de un horno rotatorio de Clinker, el cual se obtiene a partir de un balance de energía representado en el calor que se genera por la combustión de carbón y la forma como se distribuye aquel en todo el proceso. Se utilizan datos de las variables reales del proceso, obtenidas del sistema de control mediante OLE for Process Control, las cuales se operan con datos experimentales y variables que se asumen como constantes. El modelo obtenido se ajusta con dos herramientas: mínimos cuadrados y filtro Infinite Impulse Response de primer orden. Se valida y comprueba el modelo y sus ajustes utilizando dos herramientas estadísticas: diagrama de cajas y bigotes y un método de ocho métricas estadísticas relacionadas por una función difusa. La utilización de estas herramientas evidencia un desempeño satisfactorio del modelo planteado

    International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

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    •We report INICC device-associated module data of 50 countries from 2010-2015.•We collected prospective data from 861,284 patients in 703 ICUs for 3,506,562 days.•DA-HAI rates and bacterial resistance were higher in the INICC ICUs than in CDC-NHSN's.•Device utilization ratio in the INICC ICUs was similar to CDC-NHSN's. Background: We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific. Methods: During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days. Results: Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs. Conclusions: Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically
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