7,848 research outputs found
Plasmon-free Surface-enhanced Raman Spectroscopy on TiO\u3csub\u3e2\u3c/sub\u3e-graphene Oxide Inverse Opal Substrates
TiO2-graphene oxide (GO) inverse opal materials were shown to be active plasmon-free surface-enhanced Raman spectroscopy (SERS) substrates. The SERS activity of the substrates was analyzed using three different probe molecules: phenethylamine (PEA), methylene blue (MB), and 4-mercaptobenzoic acid (4-MBA). The morphology of the substrates was investigated by SEM and AFM. Prepared TiO2-GO inverse opals substrates can be reused up to five times with minimal loss of signal, rendering them perfect candidates to be used as highly stable, low-cost, metal-free, recyclable SERS substrates
Potential of duckweed for swine wastewater nutrient removal and biomass valorisation through anaerobic co-digestion
Over the last decades, phytodepuration has been considered an efficient technology to treat wastewaters. The present study reports a bench scale depuration assay of swine wastewater using Lemna minor. The highest observed growth rate obtained in swine wastewater was 3.1 ± 0.3 gDW m−2 day−1 and the highest nitrogen and phosphorus uptake were 140 mg N m−2 day−1 and 3.47 mg P m−2 day−1, respectively. The chemical oxygen demand removal efficiency in the swine wastewater assay was 58.9 ± 2.0%. Furthermore, the biomass valorisation by anaerobic co-digestion with swine wastewater was assessed. Results showed a clear improvement in specific methane production rate (around 40%) when compared to mono-substrate anaerobic digestion. The highest methane specific production, 131.0 ± 0.8 mL CH4 g−1 chemical oxygen demand, was obtained with a mixture containing 100 g of duckweed per liter of pre-treated swine wastewater. The water-nutrients-energy nexus approach showed to be promising for swine waste management.info:eu-repo/semantics/publishedVersio
Farmers' Use of Improved Seed Selection Practices in Mexican Maize: Evidence and Issues from the Sierra de Santa Marta
The principal advantage of in situ conservation is that it allows adaptive evolutionary processes to continue in the species that are being conserved. For a cultivated crop species, in situ conservation involves farmers' management of their own genetic resources even as the farmers themselves adapt to a changing environment. Improved seed selection practices and other on-farm breeding strategies have been proposed as a means of providing economic incentives for farmers to continue growing traditional varieties or landraces identified as important for conservation. This paper describes a pilot study among a group of indigenous farmers in the Sierra de Santa Marta, Veracruz, Mexico, who have collaborated in such efforts. The findings raise key issues about the potential impact of such an approach, as well as some useful methodological points for applied economists. In the study area, there is a high frequency of experimentation, exchange, loss, and replacement of seed over time -- seed of the same varieties, including both modern and traditional varieties. This poses a challenge for economists' models of varietal choice, which tend to be based on static perceptions of a 'variety' as well as simplistic distinctions between 'modern' and 'traditional' varieties. Seed selection in the study area is not a single event but an iterative, continuous process. Women may be more involved in seed selection than previously thought, which may have implications for the welfare impact of new seed selection practices. Other implications of the study are that (1) the impact of introducing practices to enhance farmers' varieties is likely to be diffuse and difficult to observe, predict, or measure, and (2) in developing analytical models of farmer decision-making as it affects the diversity of genetic resources on the farm, the most appropriate unit of analysis for predicting the effects of some policy interventions is not likely to be the individual farmer or the individual farm household. A better understanding of the 'social infrastructure' shaping seed and information flows is needed, since in the diffusion of innovations of this type, the seed system is based entirely on farmers and their interactions.Crop Production/Industries,
Continuous Time Models of Interest Rate: Testing the Mexican Data (1998-2006)
Distinct parametric models in continuous time for the interest rates are tested by means of a comparative analysis of the implied parametric and nonparametric densities. In this research the statistic developed by Ait-Sahalia (1996a) has been applied to the Mexican CETES (28 days) interest rate in the period 1998-2006. With this technique, the discrete approximation to the continuous model is unnecessary even when the data are discrete. The results allow to affirm that the models of interest rate shown in this paper are unable to describe the data of the Mexican CETES.
Towards Regimes for Sustainable Mineral Resource Management:Constitutional Reform, Law and Judicial Decisions in Latin America
This chapter examines mining legislation trends in Latin America. It focuses on the interpretation of the judicial decisions of the Constitutional Court of Colombia regarding conditions and processes for decision-making in the context of mining projects. The authors present an initial overview of the economic organisation and the sector legislation model adopted in Bolivia. The chapter anticipates a shift from sectoral regimes, which focus on exploration and exploitation, towards regimes for decision-making processes that mainstream constitutional principles and legal frameworks that apply to managing territories and their natural resources. The emphasis lies on reflecting on gaps in legal and institutional design and on corresponding challenges. This includes the need to strengthen the capacities of institutions and the actors that participate in decision-making processes to advance efforts aimed at furthering sustainable mineral resource management in the region
Museums as tools for sustainable community development : four archaeological museums in northern Peru
Understanding museums as tools for sustainable community development is one of the priorities of the international research project EU-LAC-MUSEUMS (2016-2020). This ambitious project has been explicitly designed in response to the European Union Horizon 2020 Work Programme call INT 12 (2015), ‘the cultural, scientific and social dimension of EU-LAC relations’. The project seeks to carry out a comparative analysis of small and medium-sized rural museums and their communities in Europe, Latin America and the Caribbean (EU and LAC), and to develop associated history and theory. By researching state-of-the-art initiatives in museums and community empowerment, and then moving beyond these initiatives to implement actions in partner countries, our aim has been both to transform individual lives within museum communities, and to create a method of implementation and evaluation that will be applicable to wider regions.Publisher PDFPeer reviewe
El desarrollo socioeducativo de niños y niñas entre las edades de 10 a 13 años hijos e hijas de padres y madres migrantes en el Colegio Parroquial "Espíritu Santo" del Municipio de la Trinidad, en el año lectivo 2012
El desarrollo socioeducativo de la niñez en edad escolar se ve afectada por diversos factores, entre ellos la migración.
Este trabajo investigativo está centrado en la problemática del abandono del que son objetos los niños y niñas al migrar, el padre, la madre o ambos.
El fenómeno migratorio ha venido rompiendo los lazos familiares, provocando secuelas en el desarrollo socioeducativo de la niñez y en su proceso de formación.
El objetivo de este trabajo fue precisamente determinar las causas y efectos de la migración en la niñez.
La aplicación de instrumentos ha proporcionado resultados interesantes entre los que se destacan: falta de comunicación, el deseo de satisfacer necesidades materiales, descuido de lo espiritual, moral y emocional, problemas conductuales, psicológicos, etc.
Concluido este trabajo consideramos necesario más y mejor comunicación, asumir compromisos y concientizar a la población de esta problemática, a fin de ofrecer a
esta niñez una vida mejo
La deuda en los hogares de México. Origen, causas y riesgos
El objetivo de este trabajo es determinar el índice de endeudamiento e identificar la carga financiera de los hogares en México para el 2012. Al utilizar los datos de la ENIGH se hace un análisis por déciles de ingreso real y se construye un índice de endeudamiento y se determina la carga financiera. La hipótesis a probar es que durante los últimos años los hogares de México, están acelerando su dependencia hacia la deuda para la satisfacción de sus necesidades de consumo y vivienda, que sumada a las desproporcionadas tasas de interés elevan considerablemente su carga financiera, que en muchas ocasiones frena o lleva a la quiebra de la economía de estos hogares. Los resultados indican que los hogares de los primeros tres deciles se encuentran en condiciones de insostenibilidad y no cuenta con la capacidad financiera para cumplir sus gastos y deudas, sin embargo los deciles IV, V y VI se encuentran en riesgo financiero
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