This paper presents a mathematical programing formulation for synthesizing water networks associated with shale gas hydraulic fracturing operations while accounting for the system uncertainty. The ...proposed formulation yields strategic planning that minimizes the cost considering water requirements as well as equipment capacities for treatment technologies, storage units, and disposals. The key uncertainties pertain to the water usage for fracturing and the time-based return of flowback water. The objective function is aimed at the minimization of the total annual cost, which accounts for the operating and capital costs associated with the water network. The developed model addresses the scheduling problem associated with shale gas production, which provides as output the completion phases for all the projected wells. This information is used in estimating the periods with water requirements and where flowback water can be collected. The proposed methodology includes an analysis of the optimal equipment size. An illustrative example is presented to show the capabilities of the proposed methodology.
This work presents a novel approach to recover industrial waste heat and to integrate it into utilities, refrigeration, and electricity production through the incorporation of heat exchanger networks ...and thermal engines (steam Rankine cycle, organic Rankine cycle, and absorption refrigeration cycle). The solution approach is based on the iteration between metaheuristic–deterministic optimization strategies. Metaheuristic optimization is established through the MS Excel-VBA-Aspen Plus link to obtain accurate modeling results. Deterministic optimization is implemented in the GAMS platform, where the mathematical formulation is based on a superstructure that considers all of the energy interconnections between the heat exchanger network, utilities, and thermal engines. Furthermore, economic, environmental, and social targets are evaluated. A case study is presented to show the applicability of the proposed methodology. The operating conditions obtained are presented (working fluid flow rate, temperatures, pressures, and efficiencies) for each thermal engine. Furthermore, the results show an increase in the total annual profit by 148%.
A narrative review of papers published from January 2011 to December 2021, after a literature search in selected databases using the terms “pharmacokinetics”, “ibuprofen”, “diclofenac”, “acemetacin”, ...“naproxen”, “etodolac” and “etoricoxib” was performed. From 828 articles identified, only eight met the inclusion criteria. Selective COX-2 inhibitors are associated with higher cardiovascular risk, while non-selective COX inhibitors are associated with higher gastrointestinal risk. NSAIDs with lower renal excretion with phase 2 metabolism are less likely to induce adverse effects and drug-drug interactions. Patients with frequent NSAID use needs, such as elderly patients and patients with cardiovascular disease or impaired renal function, will benefit from lower renal excretion (e.g. acemethacin, diclofenac, and etodolac) (level of evidence 3). Polymedicated patients, elderly patients, and patients with chronic alcohol abuse will be at a lower risk for adverse effects with NSAIDs that undergo phase 2 liver biotransformation, namely, acemethacin and diclofenac (level of evidence 3). Young patients, patients dealing with acute pain, or with active and/or chronic symptomatic gastritis, selective COX-2 inhibitors (celecoxib or etoricoxib) may be a better option (level of evidence 2). Knowing the individual characteristics of the patients, combined with knowledge on basic pharmacology, offers greater safety and better adherence to therapy.
Although there are several NSAIDs options to treat pain, physicians usually take special care to its prescription regarding cardiovascular and gastrointestinal side effects, despite the age of the patient. In this paper, based on the best evidence, the authors present a review of the safest NSAIDs to use in the elderly.
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•Many guidelines about NSAIDs are outdated, as they highlight the safety of naproxen to patients with cardiovascular disease.•However, as we now know, neither this is true, nor we have some NSAIDs proved superior in this case.•What we should do is to be watchful about patient features and NSAIDs differences in pharmacokinetics and pharmacodynamics.
This paper presents a new optimization framework that reconciles deterministic and metaheuristic optimization in order to solve nonconvex models. In this way, it is possible to solve the convex part ...in a software specialized in deterministic optimization and the nonconvex part using metaheuristic tools. The chosen software for the deterministic optimization part was general algebraic modeling system (GAMS), and the metaheuristic optimization algorithm is the improved multiobjective differential evolution (I-MODE) coded in visual basic for applications (VBA). Likewise, a linking strategy is proposed through VBA code to execute the GAMS solver. The new solution strategy consists in manipulating the data that serve as parameters in the problem to be solved in the GAMS platform and evaluating the performance of the optimal values of the objective functions in the I-MODE algorithm with updated values for the involved parameters. The proposed methodology is applied to the hydraulic fracturing (HF) process to obtain shale gas. The problem related to HF process corresponds to the use of fresh water necessary for the extraction of shale gas, as well as the type of technology that can be used in the treatment of flowback water. The mathematical model that optimizes the return water management problem is solved using deterministic optimization, while the scheduling is fixed using evolutionary algorithms of metaheuristic optimization strategies. The obtained results offer attractive alternatives for the specified objective functions in an acceptable computation time.
The concept of eco-industrial parks (EIPs) for integrating resources and infrastructure among several adjacent plants offers synergistic opportunities that can lead to enhanced profit, reduced ...pollution, and increased conservation of natural resources. A special class of EIPs, carbon-hydrogen-oxygen symbiosis networks (CHOSYNs), has been recently introduced for integrating hydrocarbon processing plants. The synthesis of CHOSYNs establishes multiscale benchmarks for the design by tracking the atomic fluxes of carbon, hydrogen, and oxygen atoms to develop rigorous performance benchmarks. Multiscale process synthesis techniques are then used to generate system configurations that achieve the benchmarks and to establish tradeoffs among various objectives. To date, all published research contributions for optimizing the design of CHOSYNs have focused on integrating mass among the participating plants. Opportunities exist to further increase resource efficiency by also incorporating energy integration into the design of CHOSYNs. This work addresses the design of CHOSYN through the inclusion of mass and energy integration in the benchmarking and synthesis of the network configurations. In addition to the benefits from mass and heat integration, further reduction of resource usage is explored through the incorporation of an integrated trigeneration facility. The design of CHOSYNs is evaluated by assessing economic and environmental objectives. A case study is established and solved demonstrating the mass and energy targeting techniques of this approach. Significant economic savings and sustainability enhancements of each participating plant in the CHOSYN are obtained. The outcome of the case study displays the synergistic relationship between each participating plant.
In this paper, deep learning models are developed based on a multilayer perceptron to forecast 12 month cumulative produced shale gas and 90 day produced flowback water using a study area within the ...Eagle Ford Formation as a database. These models can help decision-makers have important references when drilling new wells. Latitude, longitude, true vertical depth, lateral longitude, total proppant, and total fracture water are used as input variables. The trained models are evaluated in a study area within the Burgos Basin to analyze the energy benefits, freshwater consumption, and flowback water produced through well drilling for the first time in Mexico. A non-dominated sorting genetic algorithm is used for the minimization of total freshwater consumption and maximization of cumulative produced gas. The multilayer perceptron models showed good results. The coefficient of determination and the mean absolute error of the single-output models remained above 0.93 and below 3.00 for the validation set, respectively.
Resumen La osteomielitis crónica multifocal recurrente es una patología ósea inflamatoria atípica que afecta principalmente a niños y adultos jóvenes. Su clínica se caracteriza por un inicio gradual ...y períodos recurrentes de empeoramiento y mejoría. Los resultados de laboratorio, histopatológicos y de cultivos bacterianos suelen ser inconclusos o negativos. El diagnóstico se logra por exclusión, tras descartar las afecciones más frecuentes. Presentamos un caso con características propias de esta enfermedad, cuyo diagnóstico puede tardar años si no es sospechada.
This paper presents a mathematical programing formulation for synthesizing natural gas supply chains incorporating shale gas. The proposed formulation maximizes the profits and at the same time deals ...with the minimization of the overall environmental impact. The objective function is aimed at the maximization of the total profit, which accounts for the income obtained by selling shale, conventional, and imported gas at the markets, as well as the costs associated with the production of conventional and imported gas and the shale gas costs considering the hydraulic fracturing (including the working fluid), processing, and transportation processes. The environmental impact has been addressed through the Tool for Reduction and Assessment of Chemicals. An illustrative example is presented to show the capabilities of the proposed methodology. A case study for satisfying the national natural gas demands in Mexico is presented, where the results identify attractive options to satisfy the national natural gas demands.
Objetivo: Caracterizar los trastornos mentales de los pacientes consultantes del Servicio de Psiquiatría del Hospital Universitario de Caracas enero 2020 –enero 2021, que acudieron por primera vez y ...habían presentado infección por COVID-19 3 a 6 meses antes de consultar. Métodos: Se realizó un estudio observacional, descriptivo, retrospectivo, de corte transversal en pacientes que acudieron al Servicio de Psiquiatría del Hospital Universitario de Caracas para emergencia (por primera vez y sucesivas) por presentar patologías mentales durante y posterior a infección por COVID-19 durante el periodo enero 2020-enero 2021. Resultados: De 718 pacientes, 53 que acudieron con patologías mentales habían presentado infección previa por COVID-19 representando el 7,38%. Edad promedio 27-29 años (66,03 %). La mayoría del sexo femenino (71,69 %). El 77,35 % provenían del Distrito Capital; el 18,86 % del estado Miranda, siendo el estado civil predominante la soltería con 73,58 %; el 56,60 % estaban desempleados y el 79,24 % no poseían nivel de instrucción. En relación a los diagnósticos: trastorno depresivo mayor con síntomas ansiosos (30,18 %), trastorno depresivo (18,86 %), episodio maniforme (1,88 %) episodio psicótico agudo (18,86 %), trastorno de ansiedad generalizada (7,54 %), entre otros. Conclusión: Los síntomas psiquiátricos originados por infección por COVID-19 aparecen de forma más tardía y persisten después de la infección. Las mujeres manifestaron mayor riesgo de presentar síntomas relacionados con la salud mental; se asocia a alto nivel de vulnerabilidad a causa de la influencia de los roles sociales, ciclo reproductivo y mayor morbilidad psiquiátrica.
A typical biorefining supply chain exerts substantial impact on the regional water resources. Indeed, a complex relationship exists between the production of biomass, the processing of biomass into ...fuels and chemicals, the usage of fresh water, and the discharge of wastewater. This paper introduces an optimization framework for the design of a biorefining system while accounting for the interactions with the surrounding watershed. Special attention is paid in the use of fresh water and the discharge of wastewater to the surrounded watershed. The optimization approach also accounts for the selection of feedstocks, location of cultivation sites and biomass processing facilities, and conversion technologies. Economic and environmental objectives are used. A case study for the central-west part of Mexico is presented. The results show that economic gains may be achieved while optimizing water usage and discharge and satisfying watershed constraints.
•A mathematical model for designing a distributed biorefining systems is presented.•The proposed model incorporates the interactions with the surrounding watershed.•The nexus between water-energy-agriculture is considered.•A case study from the central-west part of Mexico is presented.
