Particle Swarm Optimization for Optimal Frequency Response with High Penetration of Photovoltaic and Wind Generation

As the installation of solar-photovoltaic and wind-generation systems continue to grow, the location must be strategically selected to maintain a reliable grid. However, such strategies are commonly subject to system adequacy constraints, while system security constraints (e.g., frequency stability, voltage limits) are vaguely explored. This may lead to inaccuracies in the optimal placement of the renewables, and thus maximum benefits may not be achieved. In this context, this paper proposes an optimization-based mathematical framework to design a robust distributed generation system, able to keep system stability in a desired range under system perturbance. The optimum placement of wind and solar renewable energies that minimizes the impact on system stability in terms of the standard frequency deviation is obtained through particle swarm optimization, which is developed in Python and executed in PowerFactory-DIgSILENT. The results reveal that the proposed approach has the potential to reduce the influence of disturbances, enhancing critical clearance time before frequency collapse and supporting secure power system operation

Research priorities for maintaining biodiversity’s contributions to people in Latin America

Maintaining biodiversity is crucial for ensuring human well-being. The authors participated in a workshop held in Palenque, Mexico, in August 2018, that brought together 30 mostly early-career scientists working in different disciplines (natural, social and economic sciences) with the aim of identifying research priorities for studying the contributions of biodiversity to people and how these contributions might be impacted by environmental change. Five main groups of questions emerged: (1) Enhancing the quantity, quality, and availability of biodiversity data; (2) Integrating different knowledge systems; (3) Improved methods for integrating diverse data; (4) Fundamental questions in ecology and evolution; and (5) Multi-level governance across boundaries. We discuss the need for increased capacity building and investment in research programmes to address these challenges

Diet and sexual segregation of bighorn sheep (Ovis canadensis mexicana Merriam) in Sonora, Mexico

Objective: To determine the diet of the bighorn sheep and identify differences in its composition between sexes and periods (reproductive and segregation). Design/methodology/approach: The study was conducted at the UMA Rancho Noche Buena, Hermosillo, Sonora, Mexico. To determine the plant species in the bighorn sheep feces the micro histological technique and a cell catalog of plants from the study area were used. From the diet information, the relative frequency, the Shannon-Weaver diversity index and the Kulczynski similarity index by sex and period (reproductive and segregation) were determined. Results: The diet of the bighorn sheep included 40 plant species, being herbaceous (36.14.4%) and grasses (26.88.9%) the most common. The male diet during the segregation period was mainly composed of grasses (36.2%) and female diet by herbaceous (30%) and grasses (29.8%). There were no differences in the diversity of the diets in males and females during the segregation period (H ́1.0), overall, their diets were very similar (80%). Limitations/implications: Collect a greater number of fecal samples by sex and period (reproductive and segregation) and to analyze the nutritional content of the plants consumed by bighorn sheep. Findings/conclusions: In this study, the sexual segregation exhibited by the bighorn sheep was not due to food preference

Research priorities for maintaining biodiversitys contributions to people in Latin America

Maintaining biodiversity is crucial for ensuring human well-being. We participated in a workshop held in Palenque, Mexico, in August 2018, that brought together thirty mostly early-career scientists working in different disciplines (natural, social and economic sciences) with the aim of identifying research priorities for studying the contributions of biodiversity to people and how these contributions might be impacted by environmental change. Five main groups of questions emerged: (1) Enhancing the quantity, quality, and availability of biodiversity data; (2) Integrating different knowledge systems; (3) Improved methods for integrating diverse data; (4) Fundamental questions in ecology and evolution; and (5) Multi-level governance across boundaries. We discuss the need for increased capacity building and investment in research programs to address these challenges.</ns7:p

Los chiles que le dan sabor al mundo

El chile es el condimento de la vida en diversas culturas del mundo. México es centro de origen y diversificación de la especie domesticada Capsicum annuum L, por lo que el chile se convirtió en elemento identitario y patrimonio biocultural de la nación. A pesar de la importancia de esta planta, desde la academia, se tienen pocos estudios integradores que analicen las complejas relaciones entre los chiles y los diferentes factores bióticos, abióticos y socioculturales que hacen posible su permanencia en el tiempo y el espacio. Este libro está conformado por 21 contribuciones de diversas mentes creativas como cocineras tradicionales, chefs, así como investigadoras e investigadores de las ciencias naturales y sociales que describen y analizan al chile mexicano con diferentes aproximaciones metodológicas y narrativas. Las evidencias presentadas desde diferentes disciplinas resaltan el uso continuo del chile como un condimento, alimento y elemento identitario en esta región del mundo. Queremos que el público lector disfrute de nuestro picante y -esperemos- sabroso compendio