224 research outputs found

    Optimizing the Layout of Run-of-River Powerplants Using Cubic Hermite Splines and Genetic Algorithms

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    Despite the clear advantages of mini hydropower technology to provide energy access in remote areas of developing countries, the lack of resources and technical training in these contexts usually lead to suboptimal installations that do not exploit the full potential of the environment. To address this drawback, the present work proposes a novel method to optimize the design of mini-hydropower plants with a robust and efficient formulation. The approach does not involve typical 2D simplifications of the terrain penstock layout. On the contrary, the problem is formulated considering arbitrary three-dimensional terrain profiles and realistic penstock layouts taking into account the bending effect. To this end, the plant layout is modeled on a continuous basis through the cubic Hermite interpolation of a set of key points, and the optimization problem is addressed using a genetic algorithm with tailored generation, mutation and crossover operators, especially designed to improve both the exploration and intensification. The approach is successfully applied to a real-case scenario with real topographic data, demonstrating its capability of providing optimal solutions while dealing with arbitrary terrain topography. Finally, a comparison with a previous discrete approach demonstrated that this algorithm can lead to a noticeable cost reduction for the problem studied

    An Evolutionary Computational Approach for Designing Micro Hydro Power Plants

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    Micro Hydro Power Plants (MHPP) constitute an effective, environmentally-friendly solution to deal with energy poverty in rural isolated areas, being the most extended renewable technology in this field. Nevertheless, the context of poverty and lack of qualified manpower usually lead to a poor usage of the resources, due to the use of thumb rules and user experience to design the layout of the plants, which conditions the performance. For this reason, the development of robust and efficient optimization strategies are particularly relevant in this field. This paper proposes a Genetic Algorithm (GA) to address the problem of finding the optimal layout for an MHPP based on real scenario data, obtained by means of a set of experimental topographic measurements. With this end in view, a model of the plant is first developed, in terms of which the optimization problem is formulated with the constraints of minimal generated power and maximum use of flow, together with the practical feasibility of the layout to the measured terrain. The problem is formulated in both single-objective (minimization of the cost) and multi-objective (minimization of the cost and maximization of the generated power) modes, the Pareto dominance being studied in this last case. The algorithm is first applied to an example scenario to illustrate its performance and compared with a reference Branch and Bound Algorithm (BBA) linear approach, reaching reductions of more than 70% in the cost of the MHPP. Finally, it is also applied to a real set of geographical data to validate its robustness against irregular, poorly sampled domains.Agencia Española de Cooperación Internacional para el Desarrollo 2014 / ACDE / 00601

    Application of Genetic Algorithms for Designing Micro-Hydro Power Plants in Rural Isolated Areas—A Case Study in San Miguelito, Honduras

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    The use of Micro-Hydro Power Plants (MHPP) has established itself as a fundamental tool to address the problem of energy poverty in rural isolated areas, having become the most used renewable energy source not just in this field but also in big scale power generation. Although the technology used has made important advances in the last few decades, it has been generally applied to big scale hydro-power systems. This fact has relegated the use of isolated MHPPs to the background. In this context, there is still a vast area of improvement in the development of optimization strategies for these projects, which in practice remains limited to the use of thumb rules. It results in a sub-optimal use of the available resources. This work proposes the use of a Genetic Algorithm (GA) to assist the design of MHPP, finding the most suitable location of the different elements of a MHPP to achieve the most efficient use of the resources. For this, a detailed model of the plant is first developed, followed by an optimization problem for the optimal design, which is formulated by considering the real terrain topographic data. The problem is presented in both single (to minimize the cost) and multi-objective (to minimize cost while maximizing the generated power) mode, providing a deep analysis of the potentiality of using GAs for designing MHPP in rural isolated areas. To validate the proposed approach, it is applied to a set of topographic data from a real scenario in Honduras. The achieved results are compared with a baseline integer-variable algorithm and other meta-heuristic algorithms, demonstrating a noticeable improvement in the solution in terms of cost.This research has been partially funded by the University of Seville under the contract “Contratos de acceso al Sistema Español de Ciencia, Tecnología e Innovación para el desarrollo del programa propio de I+D+i de la Universidad de Sevilla” of D. G. Reina

    Three-dimensional optimization of penstock layouts for micro-hydropower plants using genetic algorithms

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    A Micro Hydro-Power Plant is a suitable and effective mean to provide electric power to rural remote communities without harming the environment. However, the lack of resources and technical training in these communities frequently leads to designs based of rules of thumb, compromising both the generation capacity and efficiency. This work makes an attempt to address this problem by developing a new tool to design the layout of the plants. The proposed mechanism relies on a discrete topographic survey of the terrain and utilizes a Genetic Algorithm to optimize the installation layout, making it possible to explicitly incorporate requirements and constraints, such as power supply, cost of the installation, available water flow, and layout feasibility in accordance with the real terrain profile. The algorithm can operate in both single-objective mode (cost minimization) and multi-objective mode (cost minimization and power supply maximization), including in the latter Pareto dominance analyses. The algorithm is applied to a real scenario in a remote community in Honduras, obtaining good results in terms of generation capacity and cost reduction

    Public sector transparency through online press rooms. Management of collective resources and information on city websites of Castile and León, Spain

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    This research focuses on the transparency of the public websites of the main cities of the region of Castilla y Leon (Spain). Taking as a sample the 24 towns with more than 10,000 inhabitants, this article presents the results related to management and information about the collective resources and the issues concerning the online press room. Using a fully proven methodology developed by a larger project titled Infoparticipa Map, a particularly relevant group of results are achieved. On the one hand, information about the composition of the governing bodies is widely available, with differences between the most and least populated towns. But on the other hand, the performance of municipal power in the region is focused on the publication of general news and concession

    Re-evaluating the Neolithic: The Impact and the Consolidation of Farming Practices in the Cantabrian Region (Northern Spain)

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    Abstract:Research projects undertaken in the Cantabrian region since 1980 have produced new, high-quality information about the neolithisation process(es) in this area. It is now necessary to review this archaeological information and test the main hypotheses put forward to explain it. This paper presents an update on the archaeological evidence (sites, chronological dates, archaeozoological, archaeobotanical and technological information) for the early Neolithic in the Cantabrian region. It summarizes recent research on neolithisation in the region, and assesses the impact of this process during the early Neolithic, and its later consolidation. Although the available information is still incomplete, it is now possible to identify the focal point of the introduction of elements characteristic of the Neolithic way of life in the region. Current evidence suggests that it is in the eastern sector, where the earliest arrival of domesticates and new technologies such as pottery has been attested. The existence of continuities?such as sustained reliance on hunting and gathering and the coexistence of old and new funerary rites?suggests the persistence of native populations, which gradually participated in the neolithisation process after an ?availability phase?

    Transcriptomic profiles and diagnostic biomarkers in the Mediterranean seagrasses Posidonia oceanica and Cymodocea nodosa reveal mechanistic insights of adaptative strategies upon desalination brine stress

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    Seawater desalination by reverse osmosis is growing exponentially due to water scarcity. Byproducts of this process (e.g. brines), are generally discharged directly into the coastal ecosystem, causing detrimental effects, on benthic organisms. Understanding the cellular stress response of these organisms (biomarkers), could be crucial for establishing appropriate salinity thresholds for discharged brines. Early stress biomarkers can serve as valuable tools for monitoring the health status of brine-impacted organisms, enabling the prediction of long-term irreversible damage caused by the desalination industry. In this study, we conducted laboratory-controlled experiments to assess cellular and molecular biomarkers against brine exposure in two salinity-sensitive Mediterranean seagrasses: Posidonia oceanica and Cymodocea nodosa. Treatments involved exposure to 39, 41, and 43 psu, for 6 h and 7 days. Results indicated that photosynthetic performance remained unaffected across all treatments. However, under 43 psu, P. oceanica and C. nodosa exhibited lipid oxidative damage, which occurred earlier in P. oceanica. Additionally, P. oceanica displayed an antioxidant response at higher salinities by accumulating phenolic compounds within 6 h and ascorbate within 7 d; whereas for C. nodosa the predominant antioxidant mechanisms were phenolic compounds accumulation and total radical scavenging activity, which was evident after 7 d of brines exposure. Finally, transcriptomic analyses in P. oceanica exposed to 43 psu for 7 days revealed a poor up-regulation of genes associated with brassinosteroid response and abiotic stress response, while a high down-regulation of genes related to primary metabolism was detected. In C. nodosa, up-regulated genes were involved in DNA repair, cell cycle regulation, and reproduction, while down-regulated genes were mainly associated with photosynthesis and ribosome assembly. Overall, these findings suggest that 43 psu is a critical salinity-damage threshold for both seagrasses; and despite the moderate overexpression of several transcripts that could confer salt tolerance, genes involved in essential biological processes were severely downregulated.FRR was financed by Fondecyt #11220425 grant from ANID, Chile. CAS was financed by project ANID InES I + D 2021 (INID210013) and by Marie Skłodowska-Curie Action (888415). FBM was supported by a grant from Universidad de Alicante (Grant ID: FPUUA98)

    The U.S.-Mexico Border Infectious Disease Surveillance Project: Establishing Binational Border Surveillance

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    In 1997, the Centers for Disease Control and Prevention, the Mexican Secretariat of Health, and border health officials began the development of the Border Infectious Disease Surveillance (BIDS) project, a surveillance system for infectious diseases along the U.S.-Mexico border. During a 3-year period, a binational team implemented an active, sentinel surveillance system for hepatitis and febrile exanthems at 13 clinical sites. The network developed surveillance protocols, trained nine surveillance coordinators, established serologic testing at four Mexican border laboratories, and created agreements for data sharing and notification of selected diseases and outbreaks. BIDS facilitated investigations of dengue fever in Texas-Tamaulipas and measles in California–Baja California. BIDS demonstrates that a binational effort with local, state, and federal participation can create a regional surveillance system that crosses an international border. Reducing administrative, infrastructure, and political barriers to cross-border public health collaboration will enhance the effectiveness of disease prevention projects such as BIDS

    San Adrian: Brontze Aroko aztarnategi berria Iberiar penintsulako iparraldean San Adrian: a new site of the Bronze Age in the north of the Iberian peninsula

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    Resumen: La investigación sobre la Edad del Bronce en la región cantábrica se ha centrado tradicionalmente en el estudio de objetos de prestigio y de contextos funerarios, dando lugar a un estado de la cuestión con importantes lagunas acerca del poblamiento, las actividades cotidianas y las estrategias de subsistencia de los grupos humanos durante este período. En este artículo presentamos las evidencias recuperadas en el yacimiento de San Adrian (Sierra de Aizkorri, Gipuzkoa), cuya excavación ha permitido reconstruir aspectos relativos a los modos de vida, la base económica, la cultura material y el contexto medioambiental de una serie de ocupaciones de la Edad del Bronce. Los resultados preliminares revelan la existencia de ocupaciones de hábitat periódicas y la explotación de recursos procedentes del Valle del Ebro y de la costa atlántica, contribuyendo a reconstruir los modos de vida y la circulación de bienes cotidianos en el norte de la península ibérica.Abstract: Bronze Age studies carried out in the Cantabrian Region have traditionally focused on prestige goods and funerary contexts. As a result of this, the lack of information about daily activities, subsistence strategies, and human settlement on a regional scale is evident in the state of art. However, current research has achieved new discoveries in recent years, allowing a reconstruction of some aspects of the economic structure, settlements, material culture and the palaeoenvironment during the Bronze Age. Indeed, besides the funerary practices discovered in 1983 in San Adrian (Parztuergo Nagusia, Gipuzkoa), research has now revealed the presence of Upper Palaeolithic and Early Bronze Age occupations. This paper presents a first characterization of the retrieved evidence and a preliminary evaluation of the archaeological site and its environment. San Adrian is a tunnel-shaped cave located at 1,000 meters a.s.l. in the Aizkorri mountain range, opening a passage beneath the Atlantic-Mediterranean watershed in northern Iberia. The strategic character of this mountain site is demonstrated by the presence of Upper Palaeolithic and Bronze Age occupations, and by the construction of a road passing through it and the fortification of both its entrances in the Middle Ages. The aim of the archaeological survey started in 2008 was to identify, describe and evaluate the heritage potential of the cave, because previous fieldwork had only managed to make surface finds in the side galleries, including a medieval hoard and Bronze Age human remains. The work carried out by our research group at San Adrian includes a series of test pits and the excavation of an area nine square metres in size following stratigraphic criteria. In the current state, we identified at least two contexts corresponding to Late Upper Palaeolithic and Bronze Age occupations in the cave. Fieldwork included the sieving and flotation of sediment and the collection of samples for different types of analysis: palynology, carpology, sedimentology, and radiocarbon dating. The evidence is being studied by a multidisciplinary team according to expertise requirements for each topic: palaeobotany and environment, archaeozoology, sedimentology, geology, physical anthropology, prehistoric industries (lithics, pottery and bone) and archaeological and historical documentation. Because of its recent discovery, Upper Palaeolithic evidence remains still under study, but first results on Bronze Age layers can be presented. The ongoing archaeobotanical and archaeozoological studies reveal the exploitation of domestic plants and fauna complemented by hunting and foraging of wild species. At the same time, the archaeological artefacts and their production sequences show the exploitation of nearby resources on both sides of the mountain range, while prestige goods are absent. This evidence is also used to estimate the regularity of cave occupations and to propose a model of seasonal exploitation of the mountain environment. The results obtained reveal the exploitation of resources from both the Mediterranean and Atlantic basins, and contribute towards an understanding of the daily activities of Bronze Age societies. In addition, the evidence shows the exchange and circulation of quotidian products between the Cantabrian region and inland Iberia in other networks than those of prestige goods

    Women in (Dis)placement: The Field of Studies on Migrations, Social Remittances, Care and Gender in Chile

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    This article presents current perspectives on the gender approach to the study of migration in Chile between 1990 and 2018, contextualizing it in light of international debates in the social sciences. We will discuss how the feminization and the growth of Latin American migrations have given rise to a prolific field of research, as exemplified by studies conducted in central and northern Chile. We will show how the concepts of social remittances and caregiving permeate the Chilean debate on migrant women. We conclude with reflections on topics and perspectives to be incorporated into the Chilean research agenda on gender and migration.Se presenta un estado del arte sobre el enfoque de género en los estudios de la migración en Chile entre 1990 y 2018, contextualizándolo a la luz de debates internacionales de las ciencias sociales. Abordaremos cómo la feminización y el incremento de las migraciones latinoamericanas inauguran un prolijo campo de investigaciones, articulado a través de estudios desarrollados en el centro y en el norte de Chile. Señalaremos cómo los conceptos de remesas sociales y cuidados permean el debate chileno sobre las mujeres migrantes. Finalizamos con reflexiones sobre temas y perspectivas a ser incorporados en la agenda chilena de investigaciones sobre género y migración.The authors would like to thank the Chilean National Commission for Scientific and Technological Research (CONICYT) for funding the study that led to this article through Fondecyt Regular Project number 1160683: “Ser Mujer Mayor en Santiago. Organización social de los cuidados, feminización del envejecimiento y desigualdades acumuladas” (“Being an older woman in Santiago. Social organization of care, feminization of ageing and accumulated inequalities”), led by Herminia Gonzálvez Torralbo and Fondecyt Regular Project number 1190056: “The Boundaries of Gender Violence: Migrant Women’s Experiences in South American Border Territories” led by Menara Lube Guizardi
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