Produced water treatment by advanced oxidation processes

Abstract Different Advanced Oxidation Processes (AOPs) such as photocatalysis, Fenton-based processes and ozonation were studied to include one of these technologies within an integrated solution for produced water (PW) polishing. Synthetic PW was prepared adding toluene, xylene, naphthalene, phenol, acetic and malonic acids to a seawater matrix. Despite that in all AOPs studied in this work BTEX and naphthalene were removed, the efficiency (in terms of TOC removal) of each treatment varied largely. Among these techniques, photocatalysis was found to be the less effective for the treatment of PW, as TOC removals lower than 20% were obtained for the best scenario after 4 h treatment. In the contrary, best results were obtained by ozonation combined with H2O2, where all the organic components were removed, including a high percentage of acetic acid, which was not abated by the rest of the AOPs studied. The optimum conditions for ozonation were 4 g h−1 O3 and 1500 mg L−1 H2O2 at pH 10, where after 2 h a 74% of TOC removal was achieved and the acetic acid elimination was 78%. This condition enabled that ozonation process accounted for the lowest electric energy consumption per order of target compound destruction regarding total organic carbon (TOC)

Carnot, Stirling, Ericsson stochastic heat engines: Efficiency at maximum power

This work obtains the efficiency at maximum power for a stochastic heat engine performing Carnot-like, Stirling-like and Ericsson-like cycles. For the mesoscopic engine a Brownian particle trapped by an optical tweezers is considered. The dynamics of this stochastic engine is described as an overdamped Langevin equation with a harmonic potential, whereas is in contact with two thermal baths at different temperatures, namely, hot ($T_h$) and cold ($T_c$). The harmonic oscillator Langevin equation is transformed into a macroscopic equation associated with the mean value $\langle x^2(t)\rangle$ using the original Langevin approach. At equilibrium stationary state this quantity satisfies a state-like equation from which the thermodynamic properties are calculated. To obtained the efficiency at maximum power it is considered the finite-time cycle processes under the framework of low dissipation approach.Comment: 2 3pages, 5 figure

Electronic plasma diffusion with radiation reaction force and time-dependent electric field

In this work the explicit solution of the electronic plasma diffusion with radiation reaction force, under the action of an exponential decay external electric field is given. The electron dynamics is described by a classical generalized Langevin equation characterized by an Ornstein-Uhlenbeck-type friction memory kernel, with an effective memory time which accounts for the effective thermal interaction between the electron and its surroundings (thermal collisions between electrons + radiation reaction force). The incident electric field exerts an electric force on the electron, which in turn can induce an additional damping to the braking radiation force, allowing a delay in the electron characteristic time. This fact allows that the effective memory time be finite and positive, and as a consequence, obtaining physically admissible solutions of the stochastic Abraham-Lorentz-like equation. It is shown that the diffusion process is quasi-Markovian which includes the radiation effects.Comment: 16 pages, 8 figure

COMPETENCIA OCUPACIONAL Y RENDIMIENTO DIFERIDO DE LOS ESTUDIANTES UNIVERSITARIOS

Objetivo: determinar la relación de la competencia ocupacional con el rendimiento diferido de los estudiantes universitarios. Metodología: se contó con una muestra de 50 estudiantes con riesgo “crítico y alto” de deserción de la facultad de Salud de la Universidad de Pamplona, pertenecientes al programa de Alertas tempranas. El trabajo se fundamentó en el abordaje de investigación cuantitativo, de manera que la información muestra una perspectiva más amplia de la competencia ocupacional y el rendimiento diferido. Se utilizó la recolección y el análisis de los datos para contestar la pregunta de investigación y probar la hipótesis establecida previamente, también se confío en la medición numérica, el conteo, y el uso frecuente de la estadística, para establecer con exactitud los factores que conllevan al bajo rendimiento de los estudiantes universitarios. Resultados: se apoyaron estrategias mediante la creación de un programa denominado “la participación es el camino que nos conduce al éxito” que favoreció la participación ocupacional y, por tanto, mejoró el rendimiento académico de la población estudiada. Conclusiones: el programa estuvo orientando al desarrollo de varias etapas de fortalecimiento, generando beneficios al permitir la exploración y determinación de intereses, el desarrollo de habilidades sociales y la búsqueda de significado y crecimiento personal de la competencia ocupacional

Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

One of the major objectives of the Megacities Initiative: Local And Global Research Observations (MILAGRO-2006) campaign was to investigate the long-range transport of polluted Mexico City Metropolitan Area (MCMA) outflow and determine its downwind impacts on air quality and climate. Six research aircraft, including the National Center for Atmospheric Research (NCAR) C-130, made extensive chemical, aerosol, and radiation measurements above MCMA and more than 1000 km downwind in order to characterize the evolution of the outflow as it aged and dispersed over the Mesa Alta, Sierra Madre Oriental, Coastal Plain, and Gulf of Mexico. As part of this effort, free-floating Controlled-Meteorological (CMET) balloons, commanded to change altitude via satellite, made repeated profile measurements of winds and state variables within the advecting outflow. In this paper, we present an analysis of the data from two CMET balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated downwind with the MCMA pollution for nearly 30 h. The repeating profile measurements show the evolving structure of the outflow in considerable detail: its stability and stratification, interaction with other air masses, mixing episodes, and dispersion into the regional background. Air parcel trajectories, computed directly from the balloon wind profiles, show three transport pathways on 18–19 March: (a) high-altitude advection of the top of the MCMA mixed layer, (b) mid-level outflow over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf of Mexico, and (c) low-level outflow with entrainment into a cleaner northwesterly jet above the Coastal Plain. The C-130 aircraft intercepted the balloon-based trajectories three times on 19 March, once along each of these pathways; in all three cases, peaks in urban tracer concentrations and LIDAR backscatter are consistent with MCMA pollution. In comparison with the transport models used in the campaign, the balloon-based trajectories appear to shear the outflow far more uniformly and decouple it from the surface, thus forming a thin but expansive polluted layer over the Gulf of Mexico that is well aligned with the aircraft observations. These results provide critical context for the extensive aircraft measurements made during the 18–19 March MCMA outflow event and may have broader implications for modelling and understanding long-range transport

Super-resolution imaging of live sperm reveals dynamic changes of the actin cytoskeleton during acrosomal exocytosis

Filamentous actin (F-actin) is a key factor in exocytosis in many cell types. In mammalian sperm, acrosomal exocytosis (denoted the acrosome reaction or AR), a special type of controlled secretion, is regulated by multiple signaling pathways and the actin cytoskeleton. However, the dynamic changes of the actin cytoskeleton in live sperm are largely not understood. Here, we used the powerful properties of SiR-actin to examine actin dynamics in live mouse sperm at the onset of the AR. By using a combination of super-resolution microscopy techniques to image sperm loaded with SiR-actin or sperm from transgenic mice containing Lifeact-EGFP, six regions containing F-actin within the sperm head were revealed. The proportion of sperm possessing these structures changed upon capacitation. By performing live-cell imaging experiments, we report that dynamic changes of F-actin during the AR occur in specific regions of the sperm head. While certain F-actin regions undergo depolymerization prior to the initiation of the AR, others remain unaltered or are lost after exocytosis occurs. Our work emphasizes the utility of live-cell nanoscopy, which will undoubtedly impact the search for mechanisms that underlie basic sperm functions.Fil: Romarowski, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Velasco Félix, Ángel G.. Universidad Nacional Autónoma de México; MéxicoFil: Rodriguez, Paulina Torres. Universidad Nacional Autónoma de México; MéxicoFil: Gervasi, Mar?á G.. University Of Massachusetts Amherst;Fil: Xu, Xinran. School Of Biomedical Engineering;Fil: Luque, Guillermina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Contreras-Jiménez, Gastón. Universidad Nacional Autónoma de México; MéxicoFil: Sánchez-Cárdenas, Claudia. Universidad Nacional Autónoma de México; MéxicoFil: Ramírez-Gómez, Héctor V.. Universidad Nacional Autónoma de México; MéxicoFil: Krapf, Diego. School Of Biomedical Engineering;Fil: Visconti, Pablo E.. University Of Massachusetts Amherst;Fil: Krapf, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Guerrero, Adán. Universidad Nacional Autónoma de México; MéxicoFil: Darszon, Alberto. Universidad Nacional Autónoma de México; MéxicoFil: Buffone, Mariano Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Geographic potential of the world’s largest hornet, Vespa mandarinia Smith (Hymenoptera: Vespidae), worldwide and particularly in North America

The Asian giant hornet (AGH, Vespa mandarinia) is the world’s largest hornet, occurring naturally in the Indomalayan region, where it is a voracious predator of pollinating insects including honey bees. In September 2019, a nest of Asian giant hornets was detected outside of Vancouver, British Columbia; multiple individuals were detected in British Columbia and Washington state in 2020; and another nest was found and eradicated in Washington state in November 2020, indicating that the AGH may have successfully wintered in North America. Because hornets tend to spread rapidly and become pests, reliable estimates of the potential invasive range of V. mandarinia in North America are needed to assess likely human and economic impacts, and to guide future eradication attempts. Here, we assess climatic suitability for AGH in North America, and suggest that, without control, this species could establish populations across the Pacific Northwest and much of eastern North America. Predicted suitable areas for AGH in North America overlap broadly with areas where honey production is highest, as well as with species-rich areas for native bumble bees and stingless bees of the genus Melipona in Mexico, highlighting the economic and environmental necessity of controlling this nascent invasion

NIVEL DE PREFERENCIA DE MERMELADA ELABORADA CON ROCOTO (Capsicum pubescens) Y PIÑA (Ananas comosus)

The pace of life of the current population has led to changes in eating habits and people are likely to suffer from gastric problems. The rocoto chilli is palatable, contains vitamins, antioxidants, and has been reported that consumption of chilies benefits the digestive system. This research aimed to evaluate acceptance and consumer preference to the processed food from the binary combination of a natural fruit pulp and rocoto chilli ; two differents jams formulations to pineapple pulp and rocoto chilli pulp (ratios 1:4 and 1:8) were developed, being used sugar, pectin , potassium sorbate and citric acid, rocoto chilli pulp and pineapple pulp. The preference degree of potential consumer (53 judges aged 17 to 50 years old) was evaluated, significant differences were detected between the two jams formulations (α=0,01), 02 formulation being preferred; 62,26% of consumers expressed a willingness to purchase the preferred jam. The attributes sensory evaluated: color, smell, consistency and flavor, semi-trained panel (16 judges) was used, significant differences were detected in the intensity of color (α<0,05), the other attributes: smell, taste and consistency, judges did not detect difference between the two formulations (α=0,05). The 01 formulation pH 3.45; 75°Brix and 5700 cp at 60 rpm; the 02 formulation showed pH 3,35; 66°Brix and 4500 cp at 60 rpm.El ritmo de vida acelerado de la población actual ha producido cambios en los hábitos alimenticios y las personas están propensas a sufrir problemas gástricos. El rocoto tiene sabor agradable, contiene vitaminas, antioxidantes y su consumo beneficia al sistema digestivo. Esta investigación tuvo como propósito evaluar la aceptación y preferencia del consumidor ante un producto elaborado con la combinación binaria de pulpa de rocoto y un fruto natural; se desarrollaron dos formulaciones de mermelada de rocoto:piña (proporciones 1:4 y 1:8), empleándose pulpa de rocoto, pulpa de piña, azúcar, pectina, sorbato de potasio y ácido cítrico. Se evaluó el nivel de preferencia del consumidor potencial (53 jueces con edades entre 17 a 50 años) detectándose diferencias significativas entre las dos formulaciones de mermelada (α=0,01), prefiriéndose la formulación 02; el 62,26% de los consumidores manifestaron buena disposición para la compra de la mermelada preferida. Se empleó un panel semientrenado (16 jueces) para la evaluación sensorial de los atributos: color, olor, consistencia y sabor; se detectaron diferencias significativas en la intensidad del color (α>0,05), en la evaluación de los atributos olor, sabor y consistencia los jueces no detectaron diferencia entre las dos formulaciones (α=0,05). El análisis fisicoquímico de la formulación 01: pH 3,45; 75°Brix y 5700 cp a 60 rpm; la formulación 02: pH 3,35; 66 °Brix y 4500 cp a 60 rpm

Nonlinear dispersive waves in repulsive lattices

[EN] The propagation of nonlinear waves in a lattice of repelling particles is studied theoretically and experimentally. A simple experimental setup is proposed, consisting of an array of coupled magnetic dipoles. By driving harmonically the lattice at one boundary, we excite propagating waves and demonstrate different regimes of mode conversion into higher harmonics, strongly influenced by dispersion and discreteness. The phenomenon of acoustic dilatation of the chain is also predicted and discussed. The results are compared with the theoretical predictions of $\alpha$-FPU equation, describing a chain of masses connected by nonlinear quadratic springs and numerical simulations. The results can be extrapolated to other systems described by this equation.The work was supported by Spanish Ministry of Economy and Innovation (MINECO) and European Union FEDER through Project No. FIS2015- 65998-C2-2 and by Project No. AICO/2016/060 by Conselleria de Educacion, Investigacion, Cultura y Deporte de la Generalitat Valenciana. L.J.S.-C. gratefully acknowledge the support of PAID-01-14 at Universitat Politscnica de Valsncia. A. M. gratefully acknowledge to Generalitat Valenciana (Santiago Grisolia program).Mehrem, A.; Jimenez, N.; Salmerón-Contreras, LJ.; García-Andrés, FX.; García-Raffi, LM.; Picó Vila, R.; Sánchez Morcillo, VJ. (2017). Nonlinear dispersive waves in repulsive lattices. Physical Review E. 96(1). https://doi.org/10.1103/PhysRevE.96.012208S00220096

Efficiency Assessment between Entrapment and Covalent Bond Immobilization of Mutant -Xylosidase onto Chitosan Support

The Y509E mutant of -xylosidase from Geobacillus stearothermophilus (XynB2Y509E) (which also bears xylanase activity) has been immobilized in chitosan spheres through either entrapment or covalent bond formation methods. The maximum immobilization yield by entrapment was achieved by chitosan beads developed using a 2% chitosan solution after 1 h of maturation time in CFG buffer with ethanol. On the other hand, the highest value in covalent bond immobilization was observed when employing chitosan beads that were prepared from a 2% chitosan solution after 4 h of activation in 1% glutaraldehyde solution at pH 8. The activity expressed after immobilization by covalent bonding was 23% higher compared to the activity expressed following entrapment immobilization, with values of 122.3 and 99.4 IU.g1, respectively. Kinetic data revealed that catalytic turnover values were decreased as compared to a free counterpart. Both biocatalysts showed increased thermal and pH stability, along with an improved storage capacity, as they retained 88% and 40% of their activity after being stored at 4 C for two months. Moreover, XynB2Y509E immobilized by covalent binding also exhibited outstanding reusability, retaining 92% of activity after 10 cycles of reuse. In conclusion, our results suggest that the covalent bond method appears to be the best choice for XynB2Y509E immobilization