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108 resultados, página 7 de 10

Near-real-time welfare and livelihood impacts of an active war: Evidence from Ethiopia

Kibrom  Abay Guush Berhane Jordan Chamberlin Mehari Hiluf Abay (2023, [Artículo])

Ethiopia recently experienced a large-scale war that lasted for more than two years. Using unique High-Frequency Phone Survey (HFPS) data, which span several months before and after the outbreak of the war, this paper provides evidence on the immediate impacts of the conflict on households’ food security. We also assess potential mechanisms and evaluate impacts on proximate outcomes, including on livelihood activities and access to food markets. We use difference-in-differences and two-way fixed effects estimation to compare trends across affected and unaffected regions (households) and before and after the outbreak of the war. Seven months into the conflict, we find that the war was associated with a 37 percentage points increase in the probability of moderate to severe food insecurity. Using the Armed Conflict Location and Event Data (ACLED), we show that exposure to an additional battle leads to a 1 percentage point increase in the probability of moderate or severe food insecurity. The conflict was associated with significant reduction in access to food through supply chain disruptions and by curtailing non-farm livelihood activities. Non-farm and wage related activities were affected the most, whereas farming activities were relatively more resilient. Our estimates, which likely underestimate the true average effects on the population, constitute novel evidence on the near-real-time impacts of large-scale conflict. Our work highlights the potential of HFPS to monitor active and large-scale conflicts, especially in contexts where conventional data sources are not immediately available.

Phone Surveys CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA WAR CONFLICTS FOOD SECURITY LIVELIHOODS

Revisiting the phylogeny and taxonomy of the Pithecellobium clade (Leguminosae, Caesalpinioideae) with new generic circumscriptions

Iván Tamayo-Cen Benjamin Torke JOSE ENRIQUE LOPEZ CONTRERAS GERMAN CARNEVALI FERNANDEZ CONCHA Ivón Mercedes Ramírez Morillo Lilia Lorena Can Itza RODRIGO STEFANO DUNO (2022, [Artículo])

We present the most complete molecular phylogeny to date of the Pithecellobium clade of subfamily Caesalpinioideae. This neotropical group was informally recognised (as the Pithecellobium alliance) at the end of the 20th century by Barneby and Grimes (1996) and includes five genera and 33 species distributed from the southern United States and Caribbean Islands to north-eastern South America. Our aims were to further test the monophyly of the group and its genera and to identify sister group relationships within and amongst the genera. A phylogenetic analysis of nuclear ribosomal DNA sequences (ITS and ETS) was performed. The results provide further support for the monophyly of the Pithecellobium clade. The genera Ebenopsis, Pithecellobium and Sphinga were strongly supported as monophyletic. Havardia and Painteria were found to be non-monophyletic, prompting their re-circumscriptions and the description of two new genera: Gretheria and Ricoa. New combinations are made for the three species transferred to the new genera. © Iván Tamayo-Cen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

FABACEAE INGEAE INGOID CLADE MIMOSOID NEW WORLD PHYLOGENETIC SYSTEMATIC TAXONOMY BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) TAXONOMÍA VEGETAL TAXONOMÍA VEGETAL

El impacto de los mantenimientos preventivos en los sistemas fotovoltaicos interconectados a la red de distribución eléctrica

Kassandra Elizabeth López Esparza Raúl Pérez Bustamante GUILLERMO RAUL GARCIA FERRERA (2023, [Artículo])

La obligación de llevar un sistema o equipo a su máximo rendimiento y operación, así como la resolución de posibles fallas en el mismo, ha dado lugar a la necesidad de desarrollar un ámbito especializado dedicado exclusivamente a abordar estas obligaciones. De esto surge el campo del mantenimiento, cuyo propósito fundamental es asegurar el funcionamiento adecuado de los equipos o instalaciones en los cuales se lleva a cabo dicho trabajo, así como corregir y prevenir fallas o problemas en los sistemas en cuestión. El mantenimiento puede aplicarse en una amplia gama de sectores donde se necesite prevenir o corregir alguna operación, y en el caso del sector energético renovable esto no es una excepción. En particular, el mantenimiento de los sistemas fotovoltaicos interconectadas a la red (SFIR) busca llevar la instalación a su mejor zona de operación y funcionamiento para con esto asegurar la generación de energía. Es por esta razón, que el sector energético se ha unido al desarrollo de una rama que se dedique a la operación y mantenimiento (O&M) de los sistemas fotovoltaicos. En este artículo se exponen los resultados de un estudio de mantenimiento preventivo en una instalación fotovoltaica ubicada en el estado de Aguascalientes, el cual fue realizado por Sunna Power, una empresa dedicada a ofrecer servicios de mantenimiento a SFIR en México. El trabajo explorará el estado de la instalación previo al mantenimiento y su situación una vez que éste ha sido ejecutado. Aun cuando los SFIR requieren poco mantenimiento, este articulo pretende demostrar que a pesar de esto la implementación de un plan de mantenimiento en las instalaciones puede generar un impacto positivo en la producción de energía del sistema, mostrando los resultados obtenidos en el mantenimiento ejecutado en la instalación fotovoltaica.

The obligation to ensure that a system or piece of equipment achieves its maximum performance and functionality, and to correct any failures that may occur, has led to the need to develop a specialized field dedicated exclusively to meeting these obligations. This has given rise to the field of maintenance, the basic aim of which is to ensure the correct functioning of the equipment or installations on which the work is carried out, and to correct and prevent any failures or problems in the systems concerned; maintenance can be applied in a wide range of sectors where it is necessary to prevent or correct an operation, and the renewable energy sector is no exception. In particular, the maintenance of photovoltaic systems connected to the grid (SFIR) aims to bring the installation to its best operational and functional range in order to guarantee energy production; it is for this reason that the energy sector has participated in the development of a branch dedicated to the operation and maintenance (O&M) of photovoltaic systems. This article presents the results of a preventive maintenance study in a photovoltaic plant located in the state of Aguascalientes, carried out by Sunna Power, a company dedicated to providing maintenance services to SFIR in Mexico. The study examines the condition of the installation before maintenance and the situation after maintenance. Although SFIR requires little maintenance, this article aims to demonstrate that the implementation of a maintenance plan in the plants can nevertheless have a positive impact on the energy production of the system, displaying the results obtained in the maintenance carried out on the photovoltaic installation.

Mantenimiento preventivo Módulo fotovoltaico Plan de mantenimiento Sistema fotovoltaico Preventive maintenance Maintenance plan Photovoltaic system INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS OTRAS ESPECIALIDADES TECNOLÓGICAS OTRAS OTRAS

Generalized Neophobia: concept, theoretical model and measurement

Arturo Barraza Macías (2023, [Artículo, Artículo])

Objective: To build and validate the generalized neophobia scale and establish its prevalence and sociodemographic profile of the participants. Method: an instrumental and correlational study was carried out by applying the generalized neophobia scale to 517 people. Results: the scale has a reliability level that ranges between .79 and .88, the exploratory factor analysis reports a single factor that explains 69.29% of the total variance and the confirmatory factor analysis reports a perfect fit model; the prevalence in the surveyed population was 13.5% and it is women and younger people who report a higher level of neophobia. Conclusions: the theoretical-conceptual contributions of this research can be assessed as consistent and its empirical contribution can be considered as indicative since its main limitation is the selection of the sample determined by accessibility and availability.

fobia específica miedo situación novedosa emoción HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA specific phobia afraid novel situation

Facile synthesis of a TiO2-Al2O3-GnPs compound and its application in the photocatalytic degradation of Diuron

Alina De J. Zurita Yduarte Diana J. Gallegos Hernández URIEL ALEJANDRO SIERRA GOMEZ GLADIS JUDITH LABRADA DELGADO SALVADOR FERNANDEZ TAVIZON Pedro Jesús Herrera Franco SRINIVAS GODAVARTHI JOSE GILBERTO TORRES TORRES ADRIAN CERVANTES URIBE CLAUDIA GUADALUPE ESPINOSA GONZALEZ (2022, [Artículo])

"New ternary materials TiO2-Al2O3-GnPs (TAG) were prepared by using an innocuous sol-gel method with a slight modification for the addition of graphene nanoplatelets (GnPs), under room temperature and atmospheric pressure. The materials TiO2-Al2O3-GnPs were prepared with variations of concentration between 0.05 and 1 wt % of GnPs. In this study, we analyzed the physicochemical properties by X-ray diffraction (XRD) and UV-Vis spectroscopy, textural properties by N2 physisorption, morphology by scanning and transmission electron microscopy (SEM, TEM) and a chemical species analysis was carried out by X-ray photoelectron spectroscopic (XPS). The photocatalytic activity of each material was evaluated in the degradation of a model molecule, Diuron, a carcinogenic and cytotoxic herbicide used in farm fields. To determine reaction selectivity and mineralization degree, the photocatalytic reaction was monitored by using UV-Vis spectroscopy and total organic carbon (TOC). In samples with higher GnPs’ concentration, a good enough specific surface area of up to 379 m2/g was observed, and reduced band gap energy (2.8 eV) with respect to TiO2 and mixed oxide (3.2 and 3.1 eV respectively), was obtained. These resulting properties were the key indicator so that the materials could be applied as photocatalysts. In the photocatalytic activity determination, TAG-0.75 was the sample that showed the best results with respect to the mixed oxide; the highest photocatalytic conversion, the reduced average life time, and increased mineralization and reaction selectivity."

Graphene nanoplatelets Mixed oxides Sol-gel Photocatalytic degradation BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA