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Efficient removal of the recalcitrant metamizole contaminant from drinking water by using a CaLaCoO_(9) perovskite supported on recycled polyethylene

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Journal of Environmental Sciences 2024年第2期136卷 56-67页

作者： Ernesto Valadez-Renteria Christian Perez-Carrasco dulce yolotzin medina-velazquez Vicente Rodriguez-Gonzalez Jorge Oliva CONACYT-División de Materiales Avanzados Instituto Potosino de Investigación Científica y Tecnológica A.C.San Luis PotosíSLP 78216México División de Ciencias Básicas e Ingeniería Universidad Autónoma Metropolitana AzcapotzalcoCol.Reynosa-TamaulipasC.P.MéxicoDF 02200México

Metamizole(MZ)is a widely used anti-inflammatory *** to its common use,this contaminant is found in sewage and *** order to reduce the contamination produced by the MZ,we fabricated in this work a photocatalytic composite using recycled polyethylene(RPE)and the CaLaCoO_(9)(LCCO)*** nanoparticles had a microplate-like morphology and sizes of 1.4–5.5μm according to the analysis of *** photocatalytic properties of the LCCO powders were evaluated under ultraviolet-visible(UV-Vis)irradiation and found a removal efficiency of 96%.When the RPE+LCCO composite was employed for the photocatalytic degradation of MZ,a maximum degradation of 92.5%was *** influence of the pH on the photocatalytic activity was also studied and found that an initial pH=3 produced a total degradation of MZ after 240 min of UV-Vis ***,three reuse cycles were carried out for the pure LCCO powders and for the RPE+LCCO composites and found that the maximum loss of degradation was 5%.Furthermore,scavenger experiments demonstrated that the super oxide and hydroxyl radicals are formed during the photocatalytic reaction and were responsible for the degradation of ***,the X-ray photoelectron-spectroscopy and Raman analysis demonstrated the formation of defects(oxygen vacancies),those ones delayed the electron-hole recombination,which in turn,enhanced the degradation of the ***,the studies performed in this work proved that composites made with recycled plastics and LCCO perovskites are a low-cost and feasible alternative for the cleaning of water sources polluted with pharmaceutical compounds.

关键词： Photocatalysis Metamizole Pharmaceutical contaminant UV-Vis irradiation Perovskite

A Feedforward Controller to Regulate the Chemical Composition of Molten Steel in a Continuous Casting Tundish

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Intelligent Control and Automation 2013年第3期4卷 245-249页

作者： Miguel A. Barron dulce yolotzin Isaias Hilerio Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

A feedforward controller for the automatic regulation of chemical composition of molten steel in the tundish of a continuous casting machine is proposed in this work. The flow of molten steel inside the tundish is modeled as a distributed parameter system, and the resulting partial differential equation is transformed into a set of ordinary differential equations by means of the finite differences technique. From the above set and using a proper boundary condition, a feedforward control law is synthesized. No experimental tests are reported, however, the dynamic performance of the controller is illustrated by means of numerical simulations.

关键词： Chemical Composition Continuous Casting Distributed Parameter System Feedforward Controller Molten Steel Tundish

Advantages of early cholecystectomy in clinical practice of a terciary care center

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Hepatobiliary & Pancreatic Diseases International 2013年第1期12卷 87-93页

作者： Marta Barceló dulce María Cruz-Santamaría Cristina Alba-López María José Devesa-medina Manuel Díaz-Rubio Enrique Rey Health Research Institute San Carlos Clinical HospitalDepartment of MedicineSchool of MedicineComplutense University

BACKGROUND:Despite a number of studies show the superiority of early over delayed cholecystectomy in the treatment of acute cholecystitis,there is still controversy over the time for *** study aimed to assess the use of early versus delayed cholecystectomy for the treatment of acute cholecystitis in terms of complications,conversion to open surgery and mean hospital ***:We collected patients with acute cholecystitis treated at a referral center for a year,and retrospectively analyzed the chosen therapeutic approach,the percentage of conversion of early cholecystectomy to open surgery,appearance of surgical complications,and mean hospital ***:The study included 117 patients,44 women and 73 men,who had a mean age of 67.36±15.74 *** cholecystectomy was chosen in 31(26.5%) and delayed cholecystectomy in 74 patients(63.2%).Of the 74 patients,28(37.8%) required emergency performance of delayed cholecystectomy,and 19(25.7%) had not undergone surgery by the end of the *** no differences were observed between early and delayed cholecystectomy in terms of surgical complications and conversion to open surgery,mean hospital stay was nevertheless significantly shorter in the early versus the delayed cholecystectomy group(8.32±4.98 vs 15.96±8.89 days).CONCLUSION:Under the routine working conditions of a hospital that is neither specially dedicated to the surgical treatment of acute cholecystitis nor provided with specific management guidelines,early cholecystectomy can reduce the hospital stay without increase of the conversion rate or complications.

关键词： acute cholecystitis cholecystectomy complications

Bubbling to Jetting Transition during Argon Injection in Molten Steel

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World Journal of Engineering and Technology 2020年第4期8卷 605-616页

作者： Miguel A. Barron Joan Reyes dulce Y. medina Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

Bubbling to Jetting Transition is of the outmost importance in metallurgical processes given that the flow regime influences the refining rates, the refractory erosion, and the blockage of injection nozzles. Bubbling to jetting transition during subsonic bottom injection of argon in molten steel is studied here. The effect of the molten steel height, the injection velocity, the nozzle diameter, and the molten steel viscosity on the jet height and the bubbling to jetting transition is numerically analyzed using Computational Fluid Dynamics. Five subsonic argon injection velocities are considered: 5, 25, 50, 100 and 150 m/s. Three values of the metal height are taken into account, namely 1.5 m, 2 m and 2.5 m. Besides, three values of the nozzle diameters are considered: 0.001 m, 0.005 m and 0.01 m. Finally, three values of the molten steel viscosity are supposed: 0.0067, 0.1 and 1 kg/(m·s). It is observed that for the argon-molten steel system, the bubbling to jetting transition occurs for an injection velocity less than 25 m/s and that for the range of viscosities considered, the molten steel viscosity does not exert significant influence on the jet height and the bubbling to jetting transition. Due to the jet instability at subsonic velocities, a second transition, namely jetting to bubbling, is appreciated.

关键词： Argon Injection Bubbling to Jetting Transition CFD Injection velocity Jet Height Molten Steel Nozzle Diameter

A Straightforward Mathematical Model of Hot Metal Desulphurization

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Open Journal of Applied Sciences 2020年第6期10卷 318-327页

作者： Miguel A. Barron dulce Y. medina Joan Reyes Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

A straightforward kinetic model for the hot metal desulphurization process is presented. The model contains some of the most important parameters and variables that govern the process. The inputs, outputs and parameters of a desulphurization program employed at industry are discussed. The model is able to cope with different injection policies of desulphurizers such as mono- injection, co-injection or multi-injection. When compared to the rotary impeller method, results of this model shows that the weight of lime consumed in the lance injection method is lesser than that consumed in the rotary impeller method for the same conditions of the hot metal charge.

关键词： Desulphurization Hot Metal Kinetic Model Lance Injection Rotary Impeller

Uniform Flow of Molten Metals in Rectangular Open Channels

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World Journal of Engineering and Technology 2022年第3期10卷 518-526页

作者： Miguel A. Barron Joan Reyes dulce Y. medina Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

The flow of liquids in open channels has been studied since ancient Rome. However, the vast majority of published reports on flow in open channels are focused on the transport of drinking water and sewage disposal. The literature on the transport of molten metals in open channels is quite scarce. In this work, the uniform flow of pig iron and molten aluminum in rectangular open channels is studied. Specific energy curves are constructed and critical heights are analytically determined. The transition from subcritical to supercritical flow is analyzed as a function of the angle of inclination of the channel and the roughness of its walls. Manning’s equation is applied to the pig iron flow using data reported in the literature for molten aluminum. The need to correct the roughness coefficient for pig iron is observed in order to obtain results consistent with those previously reported.

关键词： Critical Height Froude Number Molten Metal Flow Open Channel Rectangular Channel Uniform Flow

Interaction between a Liquid Surface and an Impinging Gas Jet

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World Journal of Engineering and Technology 2021年第4期9卷 793-803页

作者： Miguel A. Barron dulce Y. medina Joan Reyes Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

The water-air and Wood’s metal-air systems are modeled by means of Computational Fluid Dynamics to study the interaction between a liquid surface and an impinging air jet under the near field blowing conditions. The effect of the air jet velocity, the height of the injection lance, and the density of the liquid on the depth of the formed cavity is numerically studied. The CFD results of the cavity depth are compared with results previously reported by other authors. The emergence of the splashing phenomenon is predicted in terms of the critical velocity for each liquid-air system. Besides, the blowing number indicates that the drop generation rate is not significant for jet velocities below the critical velocity, and therefore neither the splashing is significant.

关键词： Cavity Depth CFD Impinging Gas Jet Lance Height Liquid-Gas Interaction Splashing

Analysis of Molten Metal Distribution in the Mold of a Horizontal Centrifugal Casting

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Open Journal of Applied Sciences 2020年第7期10卷 444-454页

作者： Miguel A. Barron dulce Y. medina Joan Reyes Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Mexico City Mexico

It is numerically studied the influence of the angular velocity, the molten metal viscosity, and the mold wall roughness on the molten metal distribution in the mold of a horizontal centrifugal casting process. The undesirable raining phenomenon sometimes arises in horizontal centrifugal casting. It occurs when the molten metal rains or falls from the top of the mold to the bottom while the mold is rotating. Using Computational Fluid Dynamics simulations, the conditions for the emergence of the raining phenomenon were explored in this work. For the system considered, angular velocities less than 77 rad/s cause the emergence of the raining phenomenon and accumulation of the molten metal in the lower part of the mold, whereas angular velocities greater than 77 rad/s produce a constant thickness of the molten metal and prevent raining.

关键词： Angular velocity Centrifugal Casting Computational Fluid Dynamics Molten Metal Viscosity Wall Roughness

Energy Transfer among Modes in a Non-Slender Elastic Beam Subject to Vortex-Induced Vibration

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Computer Technology and Application 2013年第5期4卷 266-270页

作者： Miguel A. Barron dulce medina Isaias Hilerio Departamento de Materiales Universidad Autonoma Metropolitana Azcapotzalco Col. Reynosa-Tamaulipas Mexico 02200 Mexico

The vibration of an elastic beam experiencing vortex-induced vibration is numerically analyzed employing a wake-oscillator model. The influence of the excited mode, the initial velocity, the shedding pulsation and the mass ratio on the energy transfer among modes and the vibration amplitude is determined. Multiple frequencies are detected, and the power spectral density of the beam tip time series is used to calculate the dominant frequency.

关键词： Elastic beam energy transfer fluid-structure problem power spectral density vibration modes vortex-induced vibration wake-oscillator model.