With the growing population, access to clean water is one of the 21st-century world’s challenges. For this reason, different strategies to reduce pollutants in water using renewable energy sources should be exploited. Photocatalysts with extended visible light harvesting are an interesting route to degrade harmful molecules utilized in plastics, as is the case of Bisphenol A (BPA). This work uses a microwave-assisted route for the synthesis of two photocatalysts (BiOI and Bi₂MoO₆). Then, BiOI/Bi₂MoO₆ heterostructures of varied ratios were produced using the same synthetic routes. The BiOI/Bi₂MoO₆ with a flower-like shape exhibited high photocatalytic activity for BPA degradation compared to the individual BiOI and Bi₂MoO₆. The high photocatalytic activity was attributed to the matching electronic band structures and the interfacial contact between BiOI and Bi₂MoO₆, which could enhance the separation of photo-generated charges. Electrochemical, optical, structural, and chemical characterization demonstrated that it forms a BiOI/Bi₂MoO₆ p-n heterojunction. The free radical scavenging studies showed that superoxide radicals (O₂•⁻) and holes (h⁺) were the main reactive species, while hydroxyl radical (•OH) generation was negligible during the photocatalytic degradation of BPA. The results can potentiate the application of the microwave synthesis of photocatalytic materials.

Green infrastructure (GI) is increasingly linked to urban water management and can contribute to achieving water security in communities. This research uses a variation-finding comparative approach to recognize how far GI solutions are currently used to address water security in the urban developments of Monterrey City, Mexico, and Brussels-Capital Region, Belgium. A comparative content analysis of seven related urban development/sectoral plans is conducted using ATLAS.ti 9 software. The results depict the overall distribution of GI implementations, their typologies and spatial scales, water-security aspects that are addressed by GI, and the related definitions in the plans. In general, our analysis does not present a promising situation for the Monterrey case, although it reveals that policymakers have started to use GI in urban plans to address water security. Considering Brussels’ conditions, although GI solutions are much more frequent and advanced than in Monterrey plans, the region cannot be considered a frontrunner of GI policies. Comparing these two remarkably diverse areas is beneficial to illuminate universal aspects of planning, as the method provides an opportunity to gain insight from a multi-city perspective, whether developed or developing, showing the potential areas to advance urban policies.

This study intends to establish the main relations between topographic characteristics of the watershed and the main parameters of the unit hydrograph measured at the outlet. It looks to remove the subjectivity found in traditional synthetic methods and the trial and error setting of the main parameters of the hydrograph. The work was developed through physical experimentation of the rainfall-runoff process using the observed information of different watersheds of Chiapas, Mexico, as the reference. The experiments were carried out on a state-of-the-art semi-automatic runoff simulator, which was designed and built specifically for this study. Polynomial regression and fuzzy logic models were obtained to confirm the hypothesis of hydrological parameters being obtained from topographic data only by assuming uniform precipitation. Empirical relations were found for the peak flow, time to peak, base time and volume of the unit hydrograph and the watershed area, the main stream average slope, and the length of the stream of highest order. The main finding is that a unit hydrograph can be described based only on the watershed area when fuzzy logic models are applied.

El método de la avenida índice es una técnica de regionalización hidrológica ampliamente usada en el mundo. Este método, propuesto formalmente por el Servicio Geológico de los Estados Unidos, fue desarrollado tomando como base la prueba de homogeneidad hidrológica de Langbein y tiene como pasos generales la definición de la región homogénea, el planteamiento de una avenida índice, la generación de una curva regional y el uso de relaciones entre las características de la cuenca y la denominada avenida índice, la cual se toma como referencia. Las ventajas del método han sido reconocidas durante mucho tiempo, sin embargo el procedimiento de definición de la región homogénea puede presentar algunos inconvenientes. Es común, por ejemplo, el hecho de que la inclusión de una cierta estación adicional en el análisis de un cierto grupo de estaciones provoque que algunas otras de las estaciones salgan de la región homogénea o, por el contrario, al no considerar una de las estaciones del análisis, algunas de las estaciones que quedaban inicialmente fuera de la región homogénea queden ahora dentro de ella. Este comportamiento anómalo en la definición de las regiones es el motivo central de este trabajo. Aquí se plantea una modificación simple, pero muy útil en el método. Al aplicar un “filtro” que evite considerar desde un inicio aquellas estaciones que incluyen grandes desviaciones a la metodología, se comprueba que no sólo se obtienen regiones homogéneas más grandes, sino que además la calidad de la homogeneidad de éstas mejora sustancialmente. Mediante una validación cruzada se ha demostrado que mediante la aplicación del método modificado, los estimados de gastos en cuencas no aforadas son mucho mejores a los obtenidos con el procedimiento original del método.

Purpose: Mexico faces severe water availability problems, resulting in higher stress on its distribution in many states. To resolve the increasing water demand, it is essential to evaluate public water management to ensure the success of any decision-making policies to decrease the water pressure in the country. Methodology/Approach: For water management systems, benchmarking their performance relative to others can be an appropriate way to identify possible improvements. Using data from the National Census for drinking water and sanitation in 109 municipalities in the northwest region of Mexico, this analysis aims to evaluate the water management efficiency based on a two-stage Bootstrap Data Envelopment Analysis model with intermediate variables. Findings: The study found average efficiency in water system management but very low efficiency in system improvements. Additionally, no relationship was identified between the two stages or population size and density. Research Limitation/Implication: The study highlights the need for transparent water policies to address the country's shortage. Adjusting municipal public water system management operations and designing future strategic planning is essential. Originality/Value of paper: The presented analysis investigates a relationship between water management and water system improvements.

In view of the publication of the article “A simple and useful modification of the index avenue method”, the polemicist refers that there is published evidence that the original theory of the method presents deficiencies and that, in particular, some alternatives have been proposed to apply the test without the need for a common period of data, which makes its application more flexible and avoids the deduction of missing data. Ante la publicación del artículo "Una modificación simple y útil del método de la avenida índice", el polemista refiere que existen evidencias publicadas en el sentido de que la teoría original del método presenta deficiencias y que, en particular, se han planteado algunas alternativas para aplicar la prueba sin la necesidad de un periodo común de datos, lo que flexibiliza su aplicación y evita la deducción de datos faltantes.