El coeficiente de arrastre sobre la superficie del mar como función de las características del oleaje

An analysis of the performance of parameterizations for the drag coefficient CD over the ocean is presented. The results were obtained by considering detailed observations from the recent IntOA experiment in which a co-existence of wind sea and swell provides characteristic mixed sea conditions in a wide range of wind speeds. Recent research has advanced our understanding of air-sea fluxes, proposing new functional forms for the drag coefficient, as well as applying wavelength scaling and determining dimensionally consistent expressions for the drag coefficient. Nevertheless, a detailed analysis of the influence of wind sea parameters confirms the need to include the sea state dependence on parameterizing CD for mixed sea conditions. It is also shown that better results are obtained when aerodynamic roughness is considered as a function of wave age and wave steepness, or equivalently if CD is expressed as a function of a characteristic peak frequency defined through the wave momentum spectrum.Se presenta un análisis del desempeño de algunas parametrizaciones del coeficiente de arrastre CD sobre la superficie del mar. Los resultados se obtienen a partir de observaciones detalladas durante el experimento IntOA. En ese experimento la existencia simultánea de oleaje generado localmente y oleaje que proviene de tormentas lejanas, nos brinda características únicas del estado del mar con constituyentes mixtas de oleaje en una gama amplia de velocidades del viento. A través de investigaciones recientes se ha avanzado en el conocimiento de los flujos entre el océano y la atmósfera, al proponer nuevas formas funcionales del coeficiente de arrastre, así como al utilizar expresiones dimensionalmente consistentes que se basan en escalas asociadas a la longitud de onda de las olas. Los resultados de este trabajo confirman la necesidad de incluir la influencia del estado del mar en las parametrizaciones del coeficiente de arrastre, especialmente bajo condiciones mixtas de oleaje. También se demuestra que se obtienen mejores resultados cuando la escala de rugosidad aerodinámica se considera como una función de la edad de la ola y de la pendiente del oleaje local o de forma equivalente, cuando CD se expresa como función de una frecuencia característica asociada al pico espectral que se determina mediante el espectro del momento del oleaje

Wavelet spectral analysis of the free surface of turbulent flows

This work demonstrates the applicability of the wavelet directional method as a means of characterizing the free surface dynamics in shallow turbulent flows using a small number of sensors. The measurements are obtained with three conductance wave probes in a laboratory flume, in a range of subcritical flow conditions where the Froude number was smaller than one, and the bed was homogeneously rough. The characteristic spatial scale of the surface elevation is found to correspond to the wavelength of stationary waves oriented against the flow. The spectrum of the dominant distribution of waves is characterized in terms of an angular spreading function. A new procedure to estimate the mean surface velocity based on measurements of the surface elevation at only two locations is proposed. The results can inform the development of more accurate models of the surface behaviour, with applications for the remote sensing of rivers and open channel flows

Estimación del recurso eólico marino en la península de Baja California, México, utilizando la base de datos ERA5

Ponencia presentada en: XII Congreso de la Asociación Española de Climatología celebrado en Santiago de Compostela entre el 19 y el 21 de octubre de 2022.[ES]Actualmente, las metas nacionales e internacionales buscan, además de diversificar la matriz energética, reducir las emisiones de gases de efecto invernadero generadas al producir energía eléctrica. Aunado a esta problemática, en México existen regiones aisladas de la red eléctrica nacional en las que las redes locales de distribución utilizan la generación de electricidad a partir de la quema de combustibles fósiles, contribuyendo con estas emisiones al cambio climático. Este es el caso de los estados de Baja California y Baja California Sur que se encuentran en la Península de Baja California. La Península de Baja California tiene 2.500 km de costa, repartida entre el Océano Pacífico y Golfo de California, por lo que se explora el uso de energías marinas para sustituir la generación por quema de hidrocarburos en la región. En particular, la energía eólica marina posee varias ventajas sobre la energía eólica en tierra. Una de ellas es que los vientos suelen ser más fuertes que los vientos en tierra, por lo tanto, existe la posibilidad de tener mayor potencial eólico. En la zona costera de esta región existen velocidades de viento promedio alrededor de los 6 ms-1 , las cuales son apropiadas para el funcionamiento de un aerogenerador. En este trabajo se presenta una climatología tanto de la energía eólica disponible como de la energía extraíble con diferentes aerogeneradores, seleccionados de acuerdo con las velocidades de viento y las características climáticas del sitio. Para ello se utilizaron datos del reanálisis ERA5 de los últimos 20 años. Los resultados indican que la energía eólica marina es una alternativa viable para generar energía eléctrica en la región.[EN]Currently, national and international goals seek, in addition to diversifying the energy matrix, to reduce greenhouse gas emissions when producing electricity. In Mexico there are regions isolated from the national electricity grid in which local distribution networks use the generation of electricity from the burning of fossil fuels, contributing to climate change with these emissions. This is the case of the states of Baja California and Baja California Sur that are located on the Baja California Peninsula, which has 2.500 km of coastline, divided between the Pacific Ocean and the Gulf of California, for which the use of marine energy is being explored to replace generation by burning hydrocarbons in the region. In particular, offshore wind power has several advantages over onshore wind power. One of them is that the winds are usually stronger than the winds on land, therefore, there is the possibility of having greater wind potential. In the coastal zone of this region, average wind speeds of around 6 ms-1 at 10 m height were found, which is an appropriate speed for the operation of a wind turbine. In this work, a climatology of both the available wind energy and the extractable energy with different wind turbines, selected according to the wind speeds and the climatic characteristics of the site, is presented. For this, data from the ERA5 reanalysis of the last 20 years were used. The results found indicate that offshore wind energy is a viable alternative in the region to generate electricity

BADERI: an online database to coordinate handsearching activities of controlled clinical trials for their potential inclusion in systematic reviews

Background: Systematic reviews provide the best evidence on the effect of health care interventions. They rely on comprehensive access to the available scientific literature. Electronic search strategies alone may not suffice, requiring the implementation of a handsearching approach. We have developed a database to provide an Internet-based platform from which handsearching activities can be coordinated, including a procedure to streamline the submission of these references into CENTRAL, the Cochrane Collaboration Central Register of Controlled Trials. Methods: We developed a database and a descriptive analysis. Through brainstorming and discussion among stakeholders involved in handsearching projects, we designed a database that met identified needs that had to be addressed in order to ensure the viability of handsearching activities. Three handsearching teams pilot tested the proposed database. Once the final version of the database was approved, we proceeded to train the staff involved in handsearching. Results: The proposed database is called BADERI (Database of Iberoamerican Clinical Trials and Journals, by its initials in Spanish). BADERI was officially launched in October 2015, and it can be accessed at www.baderi.com/login.php free of cost. BADERI has an administration subsection, from which the roles of users are managed; a references subsection, where information associated to identified controlled clinical trials (CCTs) can be entered; a reports subsection, from which reports can be generated to track and analyse the results of handsearching activities; and a built-in free text search engine. BADERI allows all references to be exported in ProCite files that can be directly uploaded into CENTRAL. To date, 6284 references to CCTs have been uploaded to BADERI and sent to CENTRAL. The identified CCTs were published in a total of 420 journals related to 46 medical specialties. The year of publication ranged between 1957 and 2016. Conclusions: BADERI allows the efficient management of handsearching activities across different countries and institutions. References to all CCTs available in BADERI can be readily submitted to CENTRAL for their potential inclusion in systematic reviews

Coffee berry borer (Hypothenemus hampei Ferrari) trapping in coffee (Coffea arabica L.) with artisan traps at el Paraíso, Guerrero, Mexico

Objective: Evaluate three proportions of alcohol in traps with one and three windows and two different colors to capture Hypothenemus hampei Ferrari in the Paradise, Guerrero. Design/methodology/approach: 3 mixtures of ethyl:methyl alcohol was evaluated in different proportions (1:0, 0:1 and 1:1), in addition, traps were used in green and transparent colors, designed with one and three windows. A complete factorial design was used, the distribution of treatments was done in complete blocks at random with four repetitions. The variables evaluated were the number of bits captured, water loss, evaporation of the attractant and percentage of damaged fruits. Evaluations were conducted in March–July 2007. Results: There were differences between the treatments (p <0.05). Mix with 1: 1 was the best treatment, recorded an average catch of 980 trap insects week-1. In water loss the traps with a window were better than those designed with three, they recorded an average loss of 1,129.79 mL. The transparent color in traps is more efficient to prevent water loss, recorded an average loss of 905 mL. Limitations on study/implications: The design and color of the trap do not influence the capture efficiency and evaporation of the attractant. Findings/conclusions: The use of handcrafted traps of transparent color, with a window and with ratio of 1:1 ethyl and methyl alcohol, are very efficient in the trap for the control of H. hampeiObjective: To evaluate three proportions of alcohol in traps with one and three windows and two different colors to capture Hypothenemus hampei Ferrari in Coffea arabica L. plants. Design/methodology/approach: The experiment followed a completely randomized design with a complete factorial arrangement and four replications. From March to July 2007, three mixtures of ethyl: methyl alcohol were evaluated in different proportions (1: 0, 0: 1 and 1: 1). In addition, green and transparent traps were used, designed with a single or three windows. The number of captured coffee berry borers, water loss, attractant evaporation and damaged fruits percentage was evaluated. The data were analyzed through an analysis of variance and a test of means differences (Tukey, p ? 0.05). Results: The mixture of ethyl: methyl alcohol 1: 1 was the best, with an average catch of 980 trapped - insects week-1. The single window of transparent color traps was the most efficient to avoid water loss, with an average loss of 1,129.79 mL and 905 mL respectively. Limitations on study/implications: The design and color of the traps did not influence the capture efficiency and the evaporation of the attractant during the evaluated months. Therefore, it should be further evaluated during other important phenological stages for the crop. Findings/conclusions: Transparent color traps with a window and 1: 1 ethyl: methyl alcohol were efficient for capturing H. hampei and lowering their population

Planeación, gobernanza y sustentabilidad Retos y desafíos desde el enfoque territorial

Frente a la compleja realidad actual, resulta ineludible el desarrollo de la investigación científica de los fenómenos y procesos urbanos, territoriales y ambientales, que contribuya a su comprensión y la construcción de alternativas de solución a los retos y desafíos vigentes. En este contexto, el abordaje de las ciudades y regiones metropolitanas, el ordenamiento del territorio y la ocupación del espacio, así como la relación sociedad-naturaleza y la complejidad ambiental, precisa la generación de metodologías y procesos de investigación multi e inter disciplinarios que contribuyan a la comprensión de los procesos socioterritoriales, el mejoramiento de las condiciones de vida y la conservación ambiental.Programa de Fortalecimiento de la Calidad Educativa PFCE-2016 proyecto K0313101

PRESENCIA DE VIBRIO CHOLERAE EN LA ZONA COSTERA BAHÍAS DE PUERTO ÁNGEL-BARRA DE TONAMECA

Tesis de Licenciatur