FARM-LEVEL DETERMINANTS OF CONVERSION TO SUSTAINABLE FARMING PRACTICES IN THE NEW MEMBERS STATES

A field survey carried out in 2005 in the Czech Republic and Lithuania to investigate the determinants of converting to organic farming reveals that farmer's own belief and the intrinsic characteristics of the farm increase the likelihood of conversion. If the process of certification as an organic farm implies important changes of the structure of the farm, it lowers the propensity of farmers to consider the conversion to organic. When considering the case of family farms, results of a logit model reveal that apart from farmers' own belief in the environmental or food quality benefits of organic farming, availability of information/own knowledge about the characteristics of technology to be adopted, availability of extra labour, and membership to farmers' associations increase the likelihood to convert.sustainability, organic, adoption, NMS, CAP., Environmental Economics and Policy, Farm Management,

SUSTAINABILITY DIMENSIONS AND INCOME PROSPECTS FOR THE FARMING SYSTEMS IN THE NEW MEMBER STATES

An investigation carried out at the farming system level on the sustainability dimensions and agricultural income prospects in the Czech Republic and Lithuania under the implementation of the 2003 common agricultural policy reform reveals (a) the economic dimension as the leading one in terms of the overall sustainability rank position farming systems achieved, and (b) that under certain policy scenario assumptions, adoption of energy crops (Czech Republic) or conversion to organic farming (Lithuania) trigger potentially the highest farm gross income at the 2013 time horizon.sustainability, dimensions, systems, CAP, NMS, income, Environmental Economics and Policy, Farm Management,

Cooling Process Analysis of a 5-Drum System for Radioactive Waste Processing

A cooling system design for the processing of radioactive waste drums is investigated in this work, with the objective of providing insights for the determination of the air flow rate required to ensure an acceptable slag temperature (323 K or below) after 5 days. A methodology based on both 3D and 2D axisymmetric Computational Fluid Dynamics (CFD) modelling is developed. Transient temperature distributions within the drums in time and space determined by the heat transfer characteristics are studied in detail. A sensitivity analysis is also carried out assuming different physical properties of the radioactive slag. It was found out that for all variations analyzed, the maximum temperature of slag at the end of five days cooling is below 323 K, where the maximum outlet air temperature for a minimum air inlet velocity of 1 m/s is between 320 K and 323 K depending on the radioactive slag properties. When glass-like radioactive slag properties are assumed, the internal heat conduction within the slag is limiting the overall heat transfer, therefore requiring significantly longer cooling times

Experimental validation of an optical and thermal model of a Linear Fresnel Collector

2nd European Conference on Polygeneration – 30th March 1st April, 2011– Tarragona, SpainThis paper describes the design and validation of a mathematical model for a solar Fresnel collector. The function of the model is to simulate the optical and thermal dynamics of a Fresnel system for heating water. The model is validated using real data gathered from a cooling plant with double effect absorption chiller located in the School of Engineering University of Seville, Spain (Experimental cooling plant is also described in the paper). Comparison of calculated and plant measured data shows that the error is lower than 3% in the optical model and within 7% in the thermal model. The model uses a new approach to include a solar tracking mirror mechanism in one axis. This tracking has been designed to maximise the reception of available solar radiation by the absorption pipe. The thermal model used is based around classical models for solar receivers and it is validated with real operating data gathered from a supervisor system. The Fresnel model has been designed with sufficient flexibility to consider different geometries and thermal parameters, and may be used to simulate the performance of a proposed Fresnel collector system at any location

The Efficiency of Public Television in Spain: Application of the DEA Measurement Model

La eficiencia de la gestión de los recursos públicos, supone unos de los pilares básicos de la economía. El objetivo del presente artículo es medir la eficiencia en el uso de dichos recursos en las televisiones públicas autonómicas en España. Para realizar dicho estudio se utilizó el DEA (Análisis Envolvente de Datos) como técnica de análisis, lo que permitió comprobar la eficiencia o ineficiencia de dichas entidades y proponer las medidas de ajuste necesarias para conseguir la eficiencia. A partir de los datos analizados se concluye que no todas las firmas presentan eficiencia técnica y mucho menos eficiencia a escalaThe efficiency of public resource administration supposes some of the basic pillars of the economy. The objective of this article is to measure the efficiency in using these aforementioned resources at the autonomous public television stations in Spain. To carry out the study, the DEA technique (data envelopment analysis) was used. DEA made it possible to test the efficiency or inefficiency of these entities and propose necessary adjustment measures for obtaining efficiency. Based on the data analyzed, conclusions are that not all the firms evidence technical efficiency and much less, efficiency of scal

La colaboración entre maestros/maestras y padres/madres para atender a la diversidad en las instituciones educativas

En este artículo se resalta la importancia de un trabajo conjunto entre los padres y madres de familia de personas con necesidades educativas especiales y los docentes, y las diferentes formas en que esta labor se puede realizar. También se comentan los diferentes planos en los que se puede llevar a cabo un trabajo cooperativo, de tal manera que lo importante siempre se enfoque a la atención educativa de los estudiantes con NEE, se mencionan también algunos puntos que pueden ser tomados en cuenta para evitar las diferencias en las actuaciones tanto de los padres y madres de familia como de los docentes, de los estudiantes con NEE en las situaciones que le competen a las instituciones. Se considera por parte de los autores, que un trabajo coordinado, colaborativo y consciente de todas las partes que participan en el desarrollo del proceso aprendizaje de personas con NEE, siempre se verá reflejado en el éxito y realización de los potencialidades de todas las personas, y el derecho a la participación de las personas en igualdad y equiparación de oportunidade

Analytical approach to ground heat losses for high temperature thermal storage systems

A new approach to estimate the heat loss from thermal energy storage tank foundations is presented. Results are presented through analytical correlations based on numerical solutions for the steady-state heat conduction problem for thermal energy slab-on-grade tanks with uniform insulation. Model results were verified with other well-established benchmark problems with similar boundary conditions and validated with experimental data with excellent agreement. In addition to the TES foundation heat loss, new correlations for the maximum temperature and for the radial evolution of the temperature underneath the insulation layer are also provided, giving important information related to the tank foundation design. The correlated variables are of primordial importance in the tank foundation design because, due to the typical high operating storage temperatures, an inappropriate tank foundation insulation would lead not only to a not desired loss of energy but also to an inadmissible increase of the temperatures underneath the insulation layer, affecting the structural stability of the tank. The proposed correlations provide a quick method for the estimation of total tank foundation heat losses and soil maximum temperature reached underneath the insulation layer, saving time, and cost on the engineering tank foundation design process. Finally, a comprehensive parametric analysis of the variables of interest is made and a set of cases covering a wide range of tank sizes, insulation levels, depths to water table, and storage temperatures are solved

La eficiencia de las televisiones públicas en España: la aplicación del DEA como modelo de medición

La eficiencia de la gestión de los recursos públicos, supone unos de los pilares básicos de la economía. El objetivo del presente artículo es medir la eficiencia en el uso de dichos recursos en las televisiones públicas autonómicas en España. Para realizar dicho estudio se utilizó el DEA (Análisis Envolvente de Datos) como técnica de análisis, lo que permitió comprobar la eficiencia o ineficiencia de dichas entidades y proponer las medidas de ajuste necesarias para conseguir la eficiencia. A partir de los datos analizados se concluye que no todas las firmas presentan eficiencia técnica y mucho menos eficiencia a escala

Innovative concepts of Integrated Solar Combined Cycles (ISCC) using a Solid Oxide Fuel Cell (SOFC)

Concentrating Solar Power (CSP) is one of the most promising ways for electricity production of the upcoming years with high penetration of intermittent renewable energy sources such as wind and solar-photovoltaics. This is due to the fact that CSP when coupled to Thermal Energy Storage (TES) system enables large, inexpensive and flexible energy dispatch, which contributes to energy grid stabilization. At the same time, TES allows for steady operation of the power block by reducing undesirable fluctuations due to weather transient conditions and increasing the number of hours that the power block operates at design conditions 1. Despite the abovementioned advantages of CSP systems, a step further is needed for increase overall system efficiency and decrease CO2 emissions. Several studies have been performed considering high efficiency plant layouts such as combined cycle. For the latter, several works have been investigated about solar integration of combined cycle using parabolic trough and solar tower technologies. In both cases, solar energy was used for water/steam preheating and evaporation steps of the Rankine cycle in combination with the exhaust gases of fossil-fuel gas turbine engine. However, no research has been performed considering ISCC coupled with a Solid Oxide Fuel Cell (SOFC). In this research, two innovative layouts of ISCC power plants will be analyzed. First considers a ISCC based on solar tower and second a ISCC with a parabolic trough collector field coupled to the Heat Recovery Steam Generator (HRSG). The objective of this research is analyze the energy behavior of both layouts, selecting the best ISCC scheme to be coupled with a SOFC. The simulations will be performed using Thermoflex software. In both layouts, a SOFC is introduced before the combustion chamber at the topping cycle, and a Rankine cycle (bottoming cycle) with 2 pressures is considered.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Ethylene and Nitric Oxide Involvement in the Regulation of Fe and P Deficiency Responses in Dicotyledonous Plants

Iron (Fe) and phosphorus (P) are two essential elements for plant growth. Both elements are abundant in soils but with poor availability for plants, which favor their acquisition by developing morphological and physiological responses in their roots. Although the regulation of the genes related to these responses is not totally known, ethylene (ET) and nitric oxide (NO) have been involved in the activation of both Fe-related and P-related genes. The common involvement of ET and NO suggests that they must act in conjunction with other specific signals, more closely related to each deficiency. Among the specific signals involved in the regulation of Fe- or P-related genes have been proposed Fe-peptides (or Fe ion itself) and microRNAs, like miR399 (P), moving through the phloem. These Fe- or P-related phloem signals could interact with ET/NO and confer specificity to the responses to each deficiency, avoiding the induction of the specific responses when ET/NO increase due to other nutrient deficiencies or stresses. Besides the specificity conferred by these signals, ET itself could confer specificity to the responses to Fe- or P-deficiency by acting through different signaling pathways in each case. Given the above considerations, there are preliminary results suggesting that ET could regulate different nutrient responses by acting both in conjunction with other signals and through different signaling pathways. Because of the close relationship among these two elements, a better knowledge of the physiological and molecular basis of their interaction is necessary to improve their nutrition and to avoid the problems associated with their misuse. As examples of this interaction, it is known that Fe chlorosis can be induced, under certain circumstances, by a P over- fertilization. On the other hand, Fe oxides can have a role in the immobilization of P in soils. Qualitative and quantitative assessment of the dynamic of known Fe- and P-related genes expression, selected ad hoc and involved in each of these deficiencies, would allow us to get a profound knowledge of the processes that regulate the responses to both deficiencies. The better knowledge of the regulation by ET of the responses to these deficiencies is necessary to properly understand the interactions between Fe and P. This will allow the obtention of more efficient varieties in the absorption of P and Fe, and the use of more rational management techniques for P and Fe fertilization. This will contribute to minimize the environmental impacts caused by the use of P and Fe fertilizers (Fe chelates) in agriculture and to adjust the costs for farmers, due to the high prices and/or scarcity of Fe and P fertilizers. This review aims to summarize the latest advances in the knowledge about Fe and P deficiency responses, analyzing the similarities and differences among them and considering the interactions among their main regulators, including some hormones (ethylene) and signaling substances (NO and GSNO) as well as other P- and Fe-related signals