Production scheduling optimization for power-intensive processes with time-sensitive electricity prices

Continuous power-intensive processes in air separation plant can take advantage of optimal production planning to reduce the consumption of electricity. In this work a solution approach is developed based on a discrete-time scheduling formulation that allows modeling and optimizing operating decisions either in a fixed or a rolling horizon scheme. The main goal of this contribution is to find an optimal hourly schedule for next week that minimizes total energy consumption cost while satisfying all operational constraints. The MILP model is tested on real-world electricity price and demand input data. The results show optimal solutions for the proposed methodology with a modest computational effort considering a one-hour time grid and one-week time horizon.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Recovery of platinum from a spent automotive catalyst through chloride leaching and solvent extraction

ABSTRACT: Considering economics and environmental sustainability, recycling of critical metals from end-of-life devices should be a priority. In this work the hydrometallurgical treatment of a spent automotive catalytic converter (SACC) using HCl with CaCl2 as a leaching medium, and solvent extraction (SX) with a thiodiglycolamide derivative, is reported. The aim was to develop a leaching scheme allowing high Pt recoveries and minimizing Al dissolution, facilitating the application of SX. The replacement of part of HCl by CaCl2 in the leaching step is viable, without compromising Pt recovery (in the range 75-85%), as found for the mixture 2 M CaCl2 + 8 M HCl when compared to 11.6 M HCl. All leaching media showed good potential to recover Ce, particularly for higher reaction times and temperatures. Regarding SX, results achieved with a model solution were promising, but SX for Pt separation from the real SACC solution did not work as expected. For the adopted experimental conditions, the tested thiodiglycolamide derivative in toluene revealed a very good loading performance for both Pt and Fe, but Fe removal and Pt stripping from the organic phases after contact with the SACC solution were not successfully accomplished. Hence, the reutilization of the organic solvent needs improvement.info:eu-repo/semantics/publishedVersio

An Efficient MILP-Based Decomposition Strategy for Solving Large-Scale Scheduling Problems

This paper presents a MILP-based decomposition algorithm for solving large-scale scheduling problems with assembly operations in flexible flow shop environments. First, a rigorous mixed-integer linear (MILP) formulation based on the general precedence notion is developed for the problem under study. Then, the MILP model is embedded within a decomposition algorithm in order to accelerate the resolution of large-size industrial problems. The proposed solution approach is tested on several examples derived from a real-world case study arising in a shipbuilding company.Sociedad Argentina de Informática e Investigación Operativ

An Efficient MILP-Based Decomposition Strategy for Solving Large-Scale Scheduling Problems

This paper presents a MILP-based decomposition algorithm for solving large-scale scheduling problems with assembly operations in flexible flow shop environments. First, a rigorous mixed-integer linear (MILP) formulation based on the general precedence notion is developed for the problem under study. Then, the MILP model is embedded within a decomposition algorithm in order to accelerate the resolution of large-size industrial problems. The proposed solution approach is tested on several examples derived from a real-world case study arising in a shipbuilding company.Sociedad Argentina de Informática e Investigación Operativ

An Efficient MILP-Based Decomposition Strategy for Solving Large-Scale Scheduling Problems

This paper presents a MILP-based decomposition algorithm for solving large-scale scheduling problems with assembly operations in flexible flow shop environments. First, a rigorous mixed-integer linear (MILP) formulation based on the general precedence notion is developed for the problem under study. Then, the MILP model is embedded within a decomposition algorithm in order to accelerate the resolution of large-size industrial problems. The proposed solution approach is tested on several examples derived from a real-world case study arising in a shipbuilding company.Sociedad Argentina de Informática e Investigación Operativ

Aerospace Manufacturing Industry: A Simulation-based Decision Support Framework for the Scheduling of Complex Hoist Lines

This paper presents an advanced simulation model for short-term scheduling of complex hoist lines. This problem, generally found in aerospace and electroplating industries, includes several hard constraints that should be considered: single shared hoist, heterogeneous recipes, eventual recycle flows, and no buffers between workstations. Different heuristic-based strategies are incorporated into the computer model in order to improve the solutions generated over time. The aim is to reduce the number of products that must be discarded while minimizing the makespan. In addition, a graphical user interface was developed for quickly evaluating simulated schedules.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Production scheduling optimization for power-intensive processes with time-sensitive electricity prices

Continuous power-intensive processes in air separation plant can take advantage of optimal production planning to reduce the consumption of electricity. In this work a solution approach is developed based on a discrete-time scheduling formulation that allows modeling and optimizing operating decisions either in a fixed or a rolling horizon scheme. The main goal of this contribution is to find an optimal hourly schedule for next week that minimizes total energy consumption cost while satisfying all operational constraints. The MILP model is tested on real-world electricity price and demand input data. The results show optimal solutions for the proposed methodology with a modest computational effort considering a one-hour time grid and one-week time horizon.Sociedad Argentina de Informática e Investigación Operativa (SADIO

Los macroproyectos de interés social nacional y su impacto frente al ordenamiento territorial: el caso de Ciudad Verde

El presente artículo busca profundizar en la temática de los Macroproyectos de Interés Social Nacional, figura implementada por las últimas dos administraciones del nivel nacional con la intención de dinamizar la producción de Vivienda de Interés Social en todo Colombia, ahondando en las implicaciones que a nivel del ordenamiento territorial y urbano han tenido en diferentes contextos en los que se han venido ejecutando. En ese sentido, se evaluará la aplicación de este instrumento en términos de sus relaciones contextuales, manejo de los recursos del suelo y las respuestas urbano-territoriales articuladas a diferentes sistemas territoriales. De manera complementaria, se hace un análisis del Macroproyecto con mayor oferta habitacional que se construye actualmente en el país, específicamente en el Municipio de Soacha, Cundinamarca, denominado Ciudad Verde, para lo cual se tienen en cuenta algunos criterios de urbanismo sostenible con el fin de establecer los principales puntos positivos y negativos de su implementación.This paper explores the theme of the Social Housing Macroprojects, figure implemented by the national goverment in the last two administrations intended to boost the production of this kind of housing throughout Colombia, deeping into the implications over the land use that have been presenting in different contexts where they have been running. In this sense, this work evaluates the application of this instrument in terms of their contextual relationships and the management of soil resources and its urban-regional articulation at different territorial systems. Additionally, this article shows an analysis of the Macroproject with the biggest housing offer in the country, located in the municipality of Soacha , Cundinamarca, called Green City, taking into account some aspects of sustainable urbanism in order to identify the main positive and negative aspects on its implementation.Peer Reviewe

Joint effect of physical activity and sedentary behaviour on cardiovascular risk factors in Chilean adults

Background: To investigate the associations between combined categories of moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) with markers of adiposity and cardiovascular risk in adults. Methods: Overall, 5040 participants (mean age 46.4 years and 59.3% women) from the cross-sectional Chilean National Health Survey 2009–2010 were included in this study. MVPA and SB were measured using the Global Physical Activity questionnaire. Four categories were computed using MVPA- and SB-specific cut-offs (‘High-SB & Active’, ‘Low-SB & Active’, ‘High-SB & Inactive’ and ‘Low-SB & Inactive’). Results: Compared to the reference group (‘High-SB & Inactive’), those in ‘High-SB & Active’ and ‘Low-SB & Active’ were less likely to have an obese BMI (OR: 0.67 [0.54; 0.85], P = 0.0001 and 0.74 [0.59; 0.92] P = 0.0007, respectively) and less likely to have metabolic syndrome (OR: 0.63 [0.49; 0.82], P < 0.0001 and 0.72 [0.57; 0.91], P = 0.007), central obesity (OR: 0.79 [0.65; 0.96], P = 0.016 and 0.71 [0.59; 0.84], P < 0.0001), diabetes (OR: 0.45 [0.35; 0.59], P < 0.0001 and 0.44 [0.34; 0.56], P < 0.0001) and hypertension (OR: 0.52 [0.43; 0.63], P < 0.0001 and 0.60 [0.50; 0.72], P < 0.0001), respectively. Conclusions: Being physically active and spending less time in SBs was associated with lower adiposity and improvements in cardiovascular risk factors

Effect of Estradiol Benzoate on the Size of Follicle and Corpus Luteum of Holstein Cows Treated with D-Cloprostenol.

The effect of two treatments, farms, and body  shape on the size of the follicle and  Corpus Luteum  were evaluated. D-Cloprostenol (150 ug) was used in one of the treatments; in the other,  D-Cloprostenol (150 ug) and Estradiol Ben-zoate (1 mg), were used. Two groups of 32 Holstein dairy cows each, from the Nero and Irquis farms in Cuenca, Ec-uador, were set up.  Body condition  (2.75-3.50) was considered. The calving number was 1-6; the farms,  Irquis and Nero; and animal age, 3-10 years. Ultrasound scanning was used on days 0; 3 and 7, in order to measure the  Luteumfirst, then the  dominant ovarian follicle, and finally, the Corpus Luteum.  Factor analysis of variance  was  performed. No significant differences were found for follicle size due to any factors; nor due to interaction.  Concerning luteum, significant differences (P < 0.05) were observed for the treatments and for the farm. The values were 0.33 cm higher for the treatment with Benzoate, and 0.36 cm,  at  Irquis, in comparison to Nero. The treatment with Benzoate, along with better husbandry at Irquis played a critical role in the appearance and evolution of the luteum