Sustainability of irrigated farming systems in a Tunisian region: A recursive stochastic programming analysis

The aim of this study was to evaluate the sustainability of farm irrigation systems in the Cébalat district in northern Tunisia. It addressed the challenging topic of sustainable agriculture through a bio-economic approach linking a biophysical model to an economic optimisation model. A crop growth simulation model (CropSyst) was used to build a database to determine the relationships between agricultural practices, crop yields and environmental effects (salt accumulation in soil and leaching of nitrates) in a context of high climatic variability. The database was then fed into a recursive stochastic model set for a 10-year plan that allowed analysing the effects of cropping patterns on farm income, salt accumulation and nitrate leaching. We assumed that the long-term sustainability of soil productivity might be in conflict with farm profitability in the short-term. Assuming a discount rate of 10% (for the base scenario), the model closely reproduced the current system and allowed to predict the degradation of soil quality due to long-term salt accumulation. The results showed that there was more accumulation of salt in the soil for the base scenario than for the alternative scenario (discount rate of 0%). This result was induced by applying a higher quantity of water per hectare for the alternative as compared to a base scenario. The results also showed that nitrogen leaching is very low for the two discount rates and all climate scenarios. In conclusion, the results show that the difference in farm income between the alternative and base scenarios increases over time to attain 45% after 10 years.

Comparative analysis of road financing approaches in Europe and the United States

Road infrastructure has a remarkable economic and social impact on society. This is why road financing has always drawn the attention of policymakers, especially when resources available for government spending become scarce. Nations exhibit differing approaches to dealing with road transportation financing. In the United States, the current system of road funding has been called into question because some regard it as insufficient to meet the amounts now required for road expenditures. By contrast, in most European countries, road charges are very high, but these revenues are not allocated for the funding of roads. This paper analyzes the balance between charging for the use of and expenditure on the road sector in the United States and compares the American policy with those of several European countries (Germany, United Kingdom, France, Spain, and Switzerland). To that end, a methodology is defined to calculate the annual amount of fee charges levied on light and heavy vehicles in the selected countries in order to compare those charges with annual road expenditures. The results show that road charges in America are noticeably lower than those paid in Europe. Additionally, the research concludes that in Europe, road-generated revenues exceed road expenditures in all the countries studied, so road charges actually subsidize other policies. By contrast, in the United States, the public sector subsidizes the road system in order to maintain the current level of expenditure.

Discriminating Crop, Weeds and Soil Surface with a Terrestrial LIDAR Sensor

In this study, the evaluation of the accuracy and performance of a light detection and ranging (LIDAR) sensor for vegetation using distance and reflection measurements aiming to detect and discriminate maize plants and weeds from soil surface was done. The study continues a previous work carried out in a maize field in Spain with a LIDAR sensor using exclusively one index, the height profile. The current system uses a combination of the two mentioned indexes. The experiment was carried out in a maize field at growth stage 12–14, at 16 different locations selected to represent the widest possible density of three weeds: Echinochloa crus-galli (L.) P.Beauv., Lamium purpureum L., Galium aparine L.and Veronica persica Poir.. A terrestrial LIDAR sensor was mounted on a tripod pointing to the inter-row area, with its horizontal axis and the field of view pointing vertically downwards to the ground, scanning a vertical plane with the potential presence of vegetation. Immediately after the LIDAR data acquisition (distances and reflection measurements), actual heights of plants were estimated using an appropriate methodology. For that purpose, digital images were taken of each sampled area. Data showed a high correlation between LIDAR measured height and actual plant heights (R 2 = 0.75). Binary logistic regression between weed presence/absence and the sensor readings (LIDAR height and reflection values) was used to validate the accuracy of the sensor. This permitted the discrimination of vegetation from the ground with an accuracy of up to 95%. In addition, a Canonical Discrimination Analysis (CDA) was able to discriminate mostly between soil and vegetation and, to a far lesser extent, between crop and weeds. The studied methodology arises as a good system for weed detection, which in combination with other principles, such as vision-based technologies, could improve the efficiency and accuracy of herbicide spraying.

Editor web de conexiones para la creación visual de aplicaciones composicionales mediante mashup

A lo largo de este documento se describe el trabajo llevado a cabo para el logro de todos objetivos de este Trabajo Fin de Grado, el cual tiene como objetivo principal la mejora de la herramienta de edición de las conexiones internas de un mashup proporcionada actualmente por la plataforma web WireCloud. WireCloud es una plataforma web centrada en la construcción visual de mashups de aplicaciones a partir de la interconexión de pequeñas aplicaciones web denominadas widgets. Los principales inconvenientes presentes en el actual editor de conexiones que incluye esta plataforma afectan principalmente a sus usuarios con poca experiencia en diseño web. Estos usuarios tienen dificultades a la hora de interpretar el esquema de conexiones de un mashup ajeno y también, de crear el esquema de conexiones de un mashup propio. La mejora realizada supone un cambio en la metáfora utilizada para la creación de las conexiones, que ahora se organiza en torno a unidades conceptuales denominadas comportamientos que representan subconjuntos cohesionados de conexiones con significado (representando por si mismos comportamientos relevantes del mashup). Con este cambio se logra solventar los inconvenientes que presenta el actual sistema, principalmente la necesidad de crear (y visualizar) simultáneamente todas las conexiones requeridas por el mashup, lo cual supone que: a) es difícil identificar con qué propósito se ha creado cada conexión y qué relación guardan unas conexiones con otras. b) existe un riesgo de olvidar alguna conexión, fundamentalmente por ser difícil la interpretación del propósito de cada conexión y por la imposibilidad de identificar y nombrar conjuntos de conexiones que tienen un propósito determinado. Antes de implementar el código fuente se realizó un estudio pormenorizado de las tecnologías que actualmente utiliza WireCloud, además de un estudio en profundidad de la situación del anterior editor y de las nuevas características y ventajas buscadas en este nuevo editor. Con este último propósito se definieron varios casos de estudio que ayudaron a concretar qué se ha de entender por un comportamiento en el diseño de las conexiones de un mashup y también, ayudaron a definir la mejor organización visual del nuevo editor en torno al concepto de comportamiento. El resto del trabajo consistió en la implementación del nuevo editor y en la elaboración de toda la documentación relacionada: principalmente el manual de uso del nuevo editor que estará disponible como parte de la documentación online de WireCloud.---ABSTRACT---This document describes the work carried out for the achievement of all targets of this Final Project, which has as its main objective the improvement of the edition tool of the mashup’s internal connections that is currently provided by WireCloud. WireCloud is a web platform focused on building visual of web mashups from the interconnection of web applications called web widgets. The main drawbacks present in the current web editor of connections, includes on this platform, mainly affect to users with little experience in web design. These users have difficulties for interpreting the wiring diagram of any web mashup and also, creating the wiring diagram of an own web mashup. The improvement made a change in the metaphor used for creating connections, now managing a conceptual units called behaviors that represent subsets of meaningful connections. This change overcomes the drawbacks of the current system, mainly the need to create and display simultaneously all connections required by the web mashup, which means that: a) Difficultly identify what purpose is created each connection and how they relate to each other connections. b) There is the risk of forgetting some connection, mainly for being difficult to interpret the purpose of each connection and the inability to identify and name sets of connections that have a specific purpose. Before deploying the source code, the study of the technologies currently used WireCloud was performed, plus the study of the situation of the previous editor and new features and advantages searched for this new editor was performed too. For the latter purpose was defined several case studies that helped to specify what understood by behavior in the design of the connections of a web mashup and also that helped to define the best visual organization of the new behavior-oriented wiring editor. The rest of the work involved in implementing the new wiring web editor and in the preparation of all documentation related: mainly user manual for using the new wiring web editor that will be available as part of the WireCloud online documentation.

Análisis de abastecimiento energético en un sistema aislado

El objetivo del presente proyecto es conseguir un sistema de abastecimiento energético donde el coste de la energía sea mínimo, contemplando la inclusión de generación mediante energías renovables. El emplazamiento elegido para este estudio es la isla de Brava, situada en el archipiélago de Cabo Verde, África. El estudio se hace mediante un programa informático que permite obtener un sistema económicamente óptimo según unos datos de entrada. Se realizan varios estudios de la isla, empezando por el sistema de abastecimiento actual y terminando por el sistema óptimo que ofrece como solución este proyecto. Además se incluye un análisis de emisiones para poder así comparar el sistema actual con la solución propuesta. Abstract The objective of this project is to be able to have an energetic supply system where energy cost would be as minimum as possible thanks to renewable energy. Brava Island, based in Cabo Verde archipelago (Africa), is the place chosen for that study. The study relies on a commercial software. This program permits to obtain an optimum economical system based on data entries. Several studies of the island have been made. First, a look at the current supply system has been carried out. Then, a focus on the optimum system this project will offer as a solution was performed. Moreover, it includes an emission generation analysis in order to be able to compare the current system toward the solution proposed.

Producción de pólvoras salinas por vía húmeda

Valuable black powder has been produced traditionally by the wheel-mill grinding process. It is a process which evolved since the 12th century until his crowning moment ca. 1850. The current system of manufacturing black powder has barely changed in 150 years. This traditional system has and inherent risk of explosion in several stages which is not avoidable. Laws and restrictions are constantly increasing. So do the transportation costs, whatever are his final use. Nowadays the consumer price could be multiplied by easily more than ten times the original production cost. Traditional factories tend to group, merge and move away from settled areas. Obviously this protects the factories from public opinion in case of an accident thus increases the final cost of the propellant. The wet production could allow plants to scatter and decrease production costs. A wet method of production is proposed and developed in this project. The components are mixed in presence of water and extracted with an organic solvent. This conditions insures there is no risk of explosion. The method uses low and cheap technology. Precise calculations are presented among thermodynamic, legal and economic factors. Although the work is based in traditional (KNO3-C-S) black powder, other oxidizers with present interest like are studied. Furthermore, traditional production systems and quality processes are also discussed. Obtener pólvora negra ha sido posible gracias a la producción por vía seca con el molino de ruedas. Es un procedimiento que ha estado en evolución desde el siglo XII hasta su cénit a mediados del siglo XIX. Las producciones actuales utilizan este sistema que apenas ha variado en 150 años. El proceso clásico implica riesgos inherentes e inevitables de explosión en varias de sus etapas. Cada día la legislación es progresivamente más restrictiva con el transporte de explosivos. Las pólvoras, sean usadas para pirotecnia, cartuchería o materiales energéticos, están sujetas a gravámenes por el transporte. Hoy día el precio al consumidor puede llegar a estar multiplicado hasta más de diez veces el coste de producción. Las producciones tradicionales tienden a agruparse y alejarse de las poblaciones. Esto las protege, en caso de accidente, de la opinión pública aunque a costa de encarecer el producto. La producción húmeda es fácilmente escalable y apenas requiere inversión pudiendo dispersar las producciones y abaratar los costes. En este proyecto se propone un sistema de producción de explosivos salinos por vía húmeda, a través de una incorporación acuosa y una extracción con un disolvente orgánico. Las condiciones de operación aseguran que no hay riesgo ninguno de explosión. El sistema utiliza tecnología muy accesible y económica. Se han incorporado cálculos meticulosos además de discutir aspectos termodinámicos, legislativos y económicos. Aunque el trabajo se centra en la pólvora clásica (KNO3-C-S), se estudian alternativas con mayor interés actual. Así mismo se analizan los métodos de producción tradicionales y los efectos sobre la calidad de la pólvora.

Efeitos da mecanização agrícola da cultura da cana-de-açúcar nos processos erosivos: dimensionamento de terraços com base na Equação Universal de Perdas de Solo (EUPS)

A cultura da cana-de-açúcar é a segunda maior movimentação econômica na cadeia do agronegócio no Brasil. Gera riquezas através da fabricação de açúcar, etanol e cogeração de energia elétrica, além de outros subprodutos. Considerada fonte de energia renovável, a cana-de- açúcar a princípio tinha sua imagem associada a impactos negativos principalmente devido as queimadas realizadas nas lavouras para colheita manual. Nos últimos anos, baseado em decretos e no Protocolo Agro-ambiental, essa prática vem sendo abolida. Para se manter e até mesmo aumentar o rendimento das colhedoras nos canaviais, os gestores têm adotado práticas para reduzir os terraços agrícolas, com impacto nos sistemas de conservação de solos. Assim, este trabalho teve como objetivo identificar os impactos ambientais provocados pela mecanização agrícola decorrente do mau manejo e dimensionamento dos mecanismos de conservação do solo. Neste estudo também se realizou uma análise à Equação Universal de Perdas de Solo (EUPS), como ferramenta para o dimensionamento de terraços agrícolas. O estudo foi realizado em uma microbacia hidrográfica, denominada Ribeirão da Bocaina, localizada na UGRHI-13 (Tietê - Jacaré). Foi possível identificar a variabilidade amostral do solo para o dimensionamento conservacionista, gerando curvas de nível com Desníveis Verticais (D.V) desuniformes, contrariando a sistemática atual de terraços que respeita cotas múltiplas ou mesmo dimensionamentos empiristas, segundo o conhecimento local e o histórico recente da área. Algumas sugestões também foram feitas afim de torná-la uma ferramenta ainda mais eficiente, considerando condições particulares à cultura da cana-de-açúcar, tais como a influência da palhada, sulcos de plantio e diversos tipos de terraços como meios de controle à erosão. A metodologia foi satisfatória, no que tange a compreensão pelos meios de correlação entre as práticas conservacionistas e modelos de predição de perda de solo, trazendo luz à ciência na interpretação das ferramentas existentes e as lacunas a serem preenchidas.

Financing the EU Budget: Moving forward or backwards? CEPS Paperback

Often described as complex, opaque and unfair, the EU budget financing system is an ‘unfinished journey’. One of the most critical issues is that EU revenue, drawn from the cashbox of national taxation, remains intangible to the general public. The nature of the EU as a union of states and their nationals makes the visibility of EU revenue unavoidable. The political sustainability of a move that would put the legitimacy of EU revenue at the forefront of public discussion will depend on the EU institutions and member states’ ability to demonstrate that EU funds can achieve results that are truly beyond member states’ reach. In this, his third, CEPS book on the EU budget, Gabriele Cipriani assesses the current system of financing the EU budget against the criteria of simplicity, transparency, equity and democratic accountability and offers two possible options for reforming the EU revenue system. He finds that the value-added tax (VAT) is a natural choice for funding the EU budget, through a dedicated EU VAT rate as part of the national VAT and designed as such in fiscal receipts, whose use as a means for raising EU citizens’ awareness could be encouraged already in the current arrangements.