905 resultados para Sustainable Food Systems
Resumo:
Hydrogen is considered as an appealing alternative to fossil fuels in the pursuit of sustainable, secure and prosperous growth in the UK and abroad. However there exists a persisting bottleneck in the effective storage of hydrogen for mobile applications in order to facilitate a wide implementation of hydrogen fuel cells in the fossil fuel dependent transportation industry. To address this issue, new means of solid state chemical hydrogen storage are proposed in this thesis. This involves the coupling of LiH with three different organic amines: melamine, urea and dicyandiamide. In principle, thermodynamically favourable hydrogen release from these systems proceeds via the deprotonation of the protic N-H moieties by the hydridic metal hydride. Simultaneously hydrogen kinetics is expected to be enhanced over heavier hydrides by incorporating lithium ions in the proposed binary hydrogen storage systems. Whilst the concept has been successfully demonstrated by the results obtained in this work, it was observed that optimising the ball milling conditions is central in promoting hydrogen desorption in the proposed systems. The theoretical amount of 6.97 wt% by dry mass of hydrogen was released when heating a ball milled mixture of LiH and melamine (6:1 stoichiometry) to 320 °C. It was observed that ball milling introduces a disruption in the intermolecular hydrogen bonding network that exists in pristine melamine. This effect extends to a molecular level electron redistribution observed as a function of shifting IR bands. It was postulated that stable phases form during the first stages of dehydrogenation which contain the triazine skeleton. Dehydrogenation of this system yields a solid product Li2NCN, which has been rehydrogenated back to melamine via hydrolysis under weak acidic conditions. On the other hand, the LiH and urea system (4:1 stoichiometry) desorbed approximately 5.8 wt% of hydrogen, from the theoretical capacity of 8.78 wt% (dry mass), by 270 °C accompanied by undesirable ammonia and trace amount of water release. The thermal dehydrogenation proceeds via the formation of Li(HN(CO)NH2) at 104.5 °C; which then decomposes to LiOCN and unidentified phases containing C-N moieties by 230 °C. The final products are Li2NCN and Li2O (270 °C) with LiCN and Li2CO3 also detected under certain conditions. It was observed that ball milling can effectively supress ammonia formation. Furthermore results obtained from energetic ball milling experiments have indicated that the barrier to full dehydrogenation between LiH and urea is principally kinetic. Finally the dehydrogenation reaction between LiH and dicyandiamide system (4:1 stoichiometry) occurs through two distinct pathways dependent on the ball milling conditions. When ball milled at 450 RPM for 1 h, dehydrogenation proceeds alongside dicyandiamide condensation by 400 °C whilst at a slower milling speed of 400 RPM for 6h, decomposition occurs via a rapid gas desorption (H2 and NH3) at 85 °C accompanied by sample foaming. The reactant dicyandiamide can be generated by hydrolysis using the product Li2NCN.
Resumo:
Las Mipymes son un componente fundamental para el desarrollo económico y social de cualquier país, en especial de un país como Colombia en donde representan el 99,9% de las empresas actualmente constituidas, concentrando el 81% de los empleados a nivel nacional (Fedesarrollo, 2013). Aunque juegan un papel protagónico en la economía colombiana, las Mipymes aún deben recorrer un camino extenso para poder explotar todo el potencial con el que cuentan, puesto que presentan un alto índice de mortandad empresarial en los primeros años de funcionamiento, esto evidenciado en los resultados del estudio GEM (Global Entrepreneurship Monitor, 2009) en donde se encontró que sólo el 12,61% de los negocios lograron superar los 42 meses de permanencia en el mercado (El País, 2010) principalmente a causa de la ausencia de una planeación estratégica de largo plazo que les permita a los negocios emprendedores del país alcanzar la competitividad. Si bien es cierto que crear empresa es relativamente sencillo, son múltiples los retos tanto internos como externos que deben enfrentar las organizaciones para poder alcanzar una etapa de madurez empresarial, sobre todo en los primeros años de funcionamiento que son los más críticos y decisivos para el futuro de cualquier empresa, es por esto que se hace indispensable emplear estrategias que les permitan ser sostenibles a largo plazo, en un entorno altamente competitivo por empresas tanto nacionales como internacionales, siendo este uno de los propósitos fundamentales al que deberían apostar los empresarios colombianos para crear un impacto positivo en la sociedad y aportar a la competitividad nacional. Bakery Service Foods, es una empresa dedicada a la comercialización y distribución de insumos de panadería con sede en el barrio Carvajal en la ciudad de Bogotá. Desde su constitución, el 29 de diciembre de 2008, la empresa ha buscado posicionarse en un mercado en donde tanto empresas grandes como Grasco, Grupo Team, Sigra, Duquesa, Conaceites, Alvarado, Aceites Finos; así como microempresas sin infraestructura ni solidez económica, componen un entorno altamente competitivo y hacinado que representa un desafío para una pequeña empresa familiar que no cuenta con un músculo financiero significativo. Por otra parte, Bakery Service Foods a traviesa por un período de alta incertidumbre debido a que el proveedor que representa el 85% de las ventas de los productos a los cuales representan, FANAGRA S.A, atraviesa por una completa reestructuración debido a la venta de dicha empresa a una multinacional suiza. Esta situación representa un alto riesgo para la compañía y exige que se emprendan acciones oportunas que les permitan reducir la alta dependencia en un único proveedor. Teniendo en cuenta que una de las ambiciones desde la fundación de la compañía ha sido incursionar y ser una empresa competitiva en el mercado de Food Service, que perdure en el tiempo, ¿Qué tan viable es diversificar el portafolio de la empresa Bakery Service Foods (BSF) en el mercado Food Service? Con este proyecto se busca diseñar una propuesta de diversificación de portafolio para la empresa Bakery Service Foods (BSF) analizando el mercado Food Service, por medio del modelo de Ventaja Competitiva de Michael Porter; lo anterior, con el propósito de que la empresa se consolide en este mercado como un aliado estratégico para sus clientes y representados, y con un modelo de negocio sostenible a largo plazo. Finalmente, se espera que a través de la propuesta de mejora para Bakery Service Foods, se afiancen los conocimientos administrativos obtenidos durante el pregrado en Administración de Empresas, aplicando satisfactoriamente las herramientas, metodologías y bases conceptuales adquiridas, para enriquecer el proceso de aprendizaje profesional y aportar valor a una empresa colombiana desde el mercado de Food Service.
Resumo:
An approach to reduce the contamination of water sourceswith pesticides is the use of biopurificaction systems. The active core of these systems is the biomixture. The composition of biomixtures depends on the availability of local agro-industrial wastes and design should be adapted to every region. In Portugal, cork processing is generally regarded as environmentally friendly and would be interesting to find applications for its industry residues. In this work the potential use of different substrates in biomixtures, as cork (CBX); cork and straw, coat pine and LECA (Light Expanded Clay Aggregates), was tested on the degradation of terbuthylazine, difenoconazole, diflufenican and pendimethalin pesticides. Bioaugmentation strategies using the white-rot fungus Lentinula edodes inoculated into the CBX, was also assessed. The results obtained from this study clearly demonstrated the relevance of using natural biosorbents as cork residues to increase the capacity of pesticide dissipation in biomixtures for establishing biobeds. Furthermore, higher degradation of all the pesticides was achieved by use of bioaugmented biomixtures. Indeed, the biomixtures inoculated with L. edodes EL1were able to mineralize the selected xenobiotics, revelling that these white-rot fungi might be a suitable fungus for being used as inoculum sources in on-farm sustainable biopurification system, in order to increase its degradation efficiency. After 120 days, maximum degradation of terbuthylazine, difenoconazole, diflufenican and pendimethalin, of bioaugmented CBX, was 89.9%, 75.0%, 65.0% and 99.4%, respectively. The dominant metabolic route of terbuthylazine in biomixtures inoculated with L. edodes EL1 proceeded mainly via hydroxylation, towards production of terbuthylazine-hydroxy-2 metabolite. Finally, sorption process to cork by pesticides proved to be a reversible process,working cork as a mitigating factor reducing the toxicity to microorganisms in the biomixture, especially in the early stages.
Resumo:
The supply side of the food security engine is the way we farm. The current engine of conventional tillage farming is faltering and needs to be replaced. This presentation will address supply side issues of agriculture to meet future agricultural demands for food and industry using the alternate no-till Conservation Agriculture (CA) paradigm (involving no-till farming with mulch soil cover and diversified cropping) that is able to raise productivity sustainably and efficiently, reduce inputs, regenerate degraded land, minimise soil erosion, and harness the flow of ecosystem services. CA is an ecosystems approach to farming capable of enhancing not only the economic and environmental performance of crop production and land management, but also promotes a mindset change for producing ‘more from less’, the key attitude towards sustainable production intensification. CA is now spreading globally in all continents at an annual rate of 10 Mha and covers some 157 Mha of cropland. Today global agriculture produces enough food to feed three times the current population of 7.21 billion. In 1976, when the world population was 4.15 billion, world food production far exceeded the amount necessary to feed that population. However, our urban and industrialised lifestyle leads to wastage of food of some 30%-40%, as well as waste of enormous amount of energy and protein while transforming crop-based food into animal-derived food; we have a higher proportion of people than ever before who are obese; we continue to degrade our ecosystems including much of our agricultural land of which some 400 Mha is reported to be abandoned due to severe soil and land degradation; and yields of staple cereals appear to have stagnated. These are signs of unsustainability at the structural level in the society, and it is at the structural level, for both supply side and demand side, that we need transformed mind sets about production, consumption and distribution. CA not only provides the possibility of increased crop yields for the low input smallholder farmer, it also provides a pro-poor rural and agricultural development model to support agricultural intensification in an affordable manner. For the high output farmer, it offers greater efficiency (productivity) and profit, resilience and stewardship. For farming anywhere, it addresses the root causes of agricultural land degradation, sub-optimal ecological crop and land potentials or yield ceilings, and poor crop phenotypic expressions or yield gaps. As national economies expand and diversify, more people become integrated into the economy and are able to access food. However, for those whose livelihoods continue to depend on agriculture to feed themselves and the rest of the world population, the challenge is for agriculture to produce the needed food and raw material for industry with minimum harm to the environment and the society, and to produce it with maximum efficiency and resilience against abiotic and biotic stresses, including those arising from climate change. There is growing empirical and scientific evidence worldwide that the future global supplies of food and agricultural raw materials can be assured sustainably at much lower environmental and economic cost by shifting away from conventional tillage-based food and agriculture systems to no-till CA-based food and agriculture systems. To achieve this goal will require effective national and global policy and institutional support (including research and education).
Resumo:
The present study deals with the development of systematic conservation planning as management instrument in small oceanic islands, ensuring open systems of governance, and able to integrate an informed and involved participation of the stakeholders. Marxan software was used to define management areas according a set of alternative land use scenarios considering different conservation and management paradigms. Modeled conservation zones were interpreted and compared with the existing protected areas allowing more fused information for future trade-outs and stakeholder's involvement. The results, allowing the identification of Target Management Units (TMU) based on the consideration of different development scenarios proved to be consistent with a feasible development of evaluation approaches able to support sound governance systems. Moreover, the detailed geographic identification of TMU seems to be able to support participated policies towards a more sustainable management of the entire island