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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development and evaluation of methods for the measurement of airborne emissions form animal houses

Estellés Barber, Fernando 23 December 2010 (has links)
Airborne emissions from livestock production are nowadays one of the major concerns of this activity. For this reason, the reduction of these emissions is a requirement in many countries. The development of abatement techniques for the reduction of emissions needs for accurate knowledge about their magnitude. Emission measurement techniques arise then as a key issue. The development of measurement techniques considering not only the accuracy of the results but also the optimization of resources is needed. In this sense, in this thesis a tool and three options for the rationalization on the use of resources when measuring airborne emissions are investigated. The tool is the uncertainty analysis and the three options are: downscaling measurements, indirect measurement of airflow rates and reduction of sampling rates. In this thesis, theoretical and practical studies were conducted to determine the suitability of these techniques to obtain reliable data from more rational measurements on airborne emissions. Firstly, an uncertainty model was developed in order to assess the trustworthiness of the results when determining N2 and N2O emissions from a biological scrubber using a combined N-balance in air and water. This model was later partially validated throughout an experimental work in a chemical scrubber. The uncertainty model and the experimental work agreed in the key results of both studies, finding that N-balances were not successful for the proposed aims. Secondly, a flux chamber for the measurement of gas emissions from rabbits was designed and built. A measuring protocol for gas emissions from both animals and their manure was also developed. This chamber was later used to determine the CO2 emission rate from fattening rabbits during the whole fattening cycle. Using this CO2 emission rate from fattening rabbits, the carbon dioxide balance was tested as an option to determine the ventilation rate from fattening rabbit houses. The results of these balances were compared with direct measurements of ventilation rates finding no statistical differences. Finally, the effect of reducing sampling when measuring ammonia emissions from livestock facilities was evaluated. Emissions calculated using semi-continuous measurements of NH3 concentrations and airflow rates were compared with emissions calculated on 24-hour average values for these parameters. The error committed with these low time-resolution measurements resulted to be low in comparison with other error sources committed when measuring emissions from livestock facilities. The main conclusion of this work is that there are available techniques that allow optimizing the use of resources of measurement processes, by keeping the accuracy of the results. / Estellés Barber, F. (2010). Development and evaluation of methods for the measurement of airborne emissions form animal houses [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/9036 / Palancia
2

Climate Change in the Context of the Energy Reform in Mexico / El Cambio Climático en el Contexto de la Reforma Energética en México

Gutiérrez Nájera, Raquel 10 April 2018 (has links)
The author analyzes the Mexico’s energetic reform during the sexennial of 2013 to 2018. A historic study refers that Mexican energy matrix was based on fossil sources of energy as crude oil and natural gas. This represents nearly 90% of primary energy’s total production while the profit of non-fossil energy represents only 8% until 2012.Then, during the period of 2007-2012, the majority of the programmatic and normative instruments about climate change were generated. From 2013 to 2018, said the author, a national structural reform has been discussed. Thisamend includes Mexico’s energetic reform that proposes the «fossilization» of Mexican economy. This «fossilization» of the economy will favor the green growth and will constitutes itself as a barrier for Mexico’s fulfillment of international commitments assumed aboutclimate change, as well as its transition to a low carbon economy. / La autora analiza la reforma energética en México en el sexenio 2013 – 2018 a la luz de un análisis histórico sobre la matriz energética de dicho país, que al 2012 estaba basada en fuentes fósiles de energía: petróleo crudo y gas natural, que representaban conjuntamente cerca del 90% de la producción total de energía primaria; mientras que el aprovechamiento de energías no fósiles representaba solo el 8%. Asimismo, señala que en el periodo 2007- 2012 se generaron la mayoría de los instrumentos programáticos y normativos en materia de cambio climático, instrumentos que acompañaron la política internacional en la materia. En este sexenio 2013-2018, asevera la autora, se discute una reforma nacional estructural que incluye la reforma energética de México, que plantea la «fosilización» de la economía mexicana en aras de favorecer el crecimiento verde, que viene a constituirse en un obstáculo para que México pueda cumplir los compromisos internacionales asumidos en materia de cambio climático y transitar a una economía baja en carbono.

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